JP7141871B2 - Resin composition and its manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition and a method for producing the same.

Transparent resins are widely used in optical materials such as optical lenses, prisms, mirrors, optical discs, optical fibers, liquid crystal display sheets, films, and light guide plates. Widely used. However, (meth)acrylic resins have room for improvement in impact resistance. For example, (meth)acrylic resins can be improved in heat resistance while maintaining transparency by introducing a ring structure into the main chain (Patent Document 1, etc.). As a result, the resin itself becomes hard and brittle and tends to crack easily, and mechanical strength such as folding endurance tends to decrease during film processing. Therefore, as a method for increasing the strength of a (meth)acrylic resin, Patent Document 2 discloses a method of blending a flexible resin having a low glass transition temperature. Further, Patent Document 3 discloses a copolymer obtained by grafting a (meth)acrylic polymer to a polyolefin. Patent Document 4 discloses that a vinyl-based monomer containing a (meth)acrylic acid ester as a main component It is disclosed that a thermoplastic resin having excellent transparency, weather resistance, and impact resistance can be obtained by graft polymerizing the body.

JP 2006-171464 A JP 2007-100044 A JP-A-5-295183 JP-A-1-163209

In Patent Document 2, when strength is imparted by biaxial stretching, there is a problem that anisotropy of strength occurs depending on the draw ratio and the like. Moreover, when a flexible resin is blended, it is difficult to achieve both strength and transparency, and there is room for improvement. With respect to Patent Document 3, the present inventors have investigated and found that the graft copolymer tends to produce a gelled product during production, making it difficult to produce, and when applied to an optical film, the haze value is high. It became clear that the transparency tends to be insufficient. Moreover, Patent Document 4 does not disclose conditions for obtaining a thermoplastic resin that has both improved heat resistance and strength and that does not generate gel during melt molding.

The present invention has been made in view of the circumstances as described above, and an object thereof is to provide a resin composition which produces less gelling matter during molding and has excellent heat resistance. .

The inventors of the present invention have made intensive studies to solve the above problems, and as a result, the amount of olefinic double bonds in a predetermined two-component mixture is within a predetermined range. The present inventors have found that it is possible to suppress the generation of a gelled product when performing the above, and that the heat resistance of the obtained resin composition is improved, and completed the present invention.
That is, the present invention includes the following inventions.

The present invention provides a polymer chain (A) having a polymer block (a1) having a diene and/or olefin-derived unit and a polymer block (a2) having an aromatic vinyl monomer-derived unit, and (meth) A copolymer (P) having a polymer chain (B) having a unit derived from an acrylic monomer, and a (meth)acrylic polymer (Q) having the same structural unit as the polymer chain (B) wherein the amount of olefinic double bonds in the two-component mixture of the copolymer (P) and the (meth)acrylic polymer (Q) is 0.014 mmol/g or more. It is characterized by being 150 mmol/g or less.

It is preferable that the breaking energy of an unstretched film having a thickness of 160 μm is 20 mJ or more. It is preferable that the internal haze per 100 μm of thickness of the unstretched film is 2.0% or less. In addition, it is preferable that the chromaticity b* per 100 μm thickness of the unstretched film is 2.0 or less.

The resin composition of the present invention preferably has a glass transition temperature of 115° C. or higher and a thermal decomposition initiation temperature of 310° C. or higher. Moreover, the resin composition of the present invention preferably contains an antioxidant.

Further, in the present invention, in the presence of a copolymer having a polymer block (a1) having a diene and/or olefin-derived unit and a polymer block (a2) having an aromatic vinyl monomer-derived unit, ( Also included is a method for producing a resin composition, which comprises a step of polymerizing a monomer component containing a meth)acrylic monomer, wherein the polymerization conversion of the monomer component is 85% or more. It is preferable to polymerize the monomer component in the presence of the copolymer and a radical polymerization initiator.

Furthermore, the present invention also includes an optical film containing the above resin composition.

The resin composition of the present invention produces less gelled matter during molding and is excellent in heat resistance.

The present invention provides a polymer chain (A) having a polymer block (a1) having a diene and/or olefin-derived unit and a polymer block (a2) having an aromatic vinyl monomer-derived unit, and (meth) A copolymer (P) having a polymer chain (B) having a unit derived from an acrylic monomer, and a (meth)acrylic polymer (Q) having the same structural unit as the polymer chain (B) It relates to a resin composition containing

1. Copolymer (P)
The copolymer (P) contains a polymer chain (A) having a polymer block (a1) functioning as a soft component and a polymer block (a2) functioning as a hard component, thereby enhancing mechanical strength. A resin composition containing the copolymer (P) has high mechanical strength (for example, impact resistance (falling ball strength)). In addition, transparency and heat resistance are enhanced by containing the polymer chain (B), and a resin composition containing such a copolymer (P) exhibits high transparency and high mechanical strength (e.g., impact resistance). (falling ball strength)) can be compatible.

Examples of the diene forming the diene-derived unit of the polymer block (a1) include 1,3-butadiene (alias: butadiene), 2-methyl-1,3-butadiene (alias: isoprene), 1,3-pentadiene, Alkadienes such as 1,4-pentadiene, 1,5-hexadiene, 2,5-dimethyl-1,5-hexadiene (also known as diisobutene) are preferably used, and among these, 1,3-butadiene, 2-methyl-1, Conjugated dienes such as 3-butadiene and 1,3-pentadiene are more preferred.
The olefins forming the olefin-derived units of the polymer block (a1) include ethylene, propylene, 1-butene, isobutene, 2-methyl-1-butene, 3-methyl-1-butene, 1-tetradecene, 1- Monoolefins (also referred to as alkenes) such as octadecene are preferably used, and α-olefins, which are alkenes having a carbon-carbon double bond at the α-position, are more preferable. The number of carbon atoms in these dienes and olefins is preferably 2 or more, more preferably 3 or more, and preferably 20 or less, more preferably 10 or less, and even more preferably 6 or less.

Diene and/or olefin derived units are defined as units formed by polymerizing dienes and/or olefins. The olefin-derived units are not limited to those actually formed by homopolymerization or copolymerization of olefins, as long as the same structure is formed, and may be formed by hydrogenation of diene-derived units. , In this specification, "homopolymerization or copolymerization" is expressed as "homopolymerization/copolymerization", and "homopolymerization or copolymerization" is expressed as "(homopolymerization/co)polymerization". may be indicated). The polymer block (a1) contains, as diene and/or olefin-derived units, butadiene-derived units, isoprene-derived units, ethylene-derived units, propylene-derived units, 1-butene-derived units, and isobutene-derived units. At least one selected from units is preferably included.

Examples of the polymer block (a1) include olefin (homo/co)polymers such as polyethylene, polypropylene, polybutene-1, ethylene-propylene copolymer and ethylene-butene copolymer; polyisoprene, polybutadiene, isoprene- Diene (homo/co)polymers such as butadiene copolymers; copolymers of olefins and dienes such as ethylene-propylene-diene copolymers and isobutene-isoprene copolymers; The olefin (homo/co)polymer is preferably an α-olefin (homo/co)polymer, and the diene (homo/co)polymer is preferably a conjugated diene (homo/co)polymer. A copolymer of an α-olefin and a conjugated diene is preferred as the polymer. Among these, copolymers of α-olefins and conjugated dienes such as polyisoprene and isobutene-isoprene copolymers, and polyethylene and polypropylene are more preferred.

The polymer block (a1) may have units derived from other unsaturated monomers in addition to units derived from dienes and/or olefins. Other unsaturated monomers are not particularly limited as long as they are compounds having a polymerizable double bond. Examples include vinyl esters such as vinyl acetate and vinyl propionate; (meth)acrylic acid, maleic anhydride, (meth) ) unsaturated carboxylic acids such as methyl acrylate and ethyl (meth)acrylate and their esters; vinylsilanes such as vinyltrimethoxysilane and γ-(meth)acryloyloxypropylmethoxysilane; and aromatic vinyl monomers, etc. mentioned.

Aromatic vinyl monomers are not particularly limited as long as they are compounds in which a vinyl group is bonded to an aromatic ring. Examples include styrene, vinyltoluene, methoxystyrene, α-methylstyrene, α-hydroxymethylstyrene, α-hydroxyethyl Styrenic monomers such as styrene; polycyclic aromatic hydrocarbon ring vinyl monomers such as 2-vinylnaphthalene; aromatic heterocyclic vinyl monomers such as N-vinylcarbazole, 2-vinylpyridine, vinylimidazole, and vinylthiophene and the like. Among these, styrenic monomers are preferred. Styrenic monomers include not only styrene but also styrene derivatives in which any substituent is attached to the polymerizable double-bond carbon of styrene or the benzene ring, and the substituents include alkyl groups, alkoxy groups, hydroxy group, halogen group, amino group, nitro group, sulfo group and the like. The alkyl group and alkoxy group bonded to styrene preferably have 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms. may be substituted with a group. From the viewpoint of reducing coloring of the copolymer (P), the styrene-based monomer preferably does not have an amino group. Furthermore, the styrenic monomer is preferably unsubstituted styrene in which no substituent is attached to the polymerizable double-bond carbon of styrene or the benzene ring.

Polymer block (a1) may be a copolymer of these other unsaturated monomers with dienes and/or olefins. An aromatic vinyl monomer is preferable as the other unsaturated monomer. When a copolymer of an aromatic vinyl monomer and a diene and/or an olefin is used as the polymer block (a1), the transparency of the copolymer (P) can be easily increased. For example, even when the difference in refractive index between the polymer chains (A) and the polymer chains (B) of the copolymer (P) is large, it is easy to increase the transparency of the copolymer (P).

When the polymer block (a1) has an aromatic vinyl monomer-derived unit, the content of the aromatic vinyl monomer-derived unit is preferably 1% by mass or more in the polymer block (a1). It is preferably 2% by mass or more, more preferably 3% by mass or more, and preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less. In this case, the total content of diene and/or olefin-derived units and aromatic vinyl monomer-derived units in the polymer block (a1) is preferably 70% by mass or more, and 80% by mass or more. is more preferable, and 90% by mass or more is even more preferable. The polymer block (a1) may consist essentially only of diene and/or olefin-derived units and aromatic vinyl monomer-derived units, for example, the total content of these units is 99% by mass. or more.

When the polymer block (a1) has units derived from other unsaturated monomers in addition to units derived from dienes and/or olefins, the polymer block (a1) contains these monomers is preferably a random copolymer of

In addition, the polymer block (a1) preferably contains diene and/or olefin-derived units as a main component. It is preferably at least 60% by mass, more preferably at least 70% by mass. The polymer block (a1) may consist essentially of diene- and/or olefin-derived units, for example, the diene- and/or olefin-derived units may be 99% by mass or more.

The polymer block (a2) has units derived from aromatic vinyl monomers. Examples of the aromatic vinyl monomer forming the polymer block (a2) include the aromatic vinyl monomers exemplified for the polymer block (a1) above.

The polymer block (a2) may have units derived from other unsaturated monomers in addition to the units derived from the aromatic vinyl monomer. Other unsaturated monomers are not particularly limited as long as they are compounds having a polymerizable double bond. Examples include vinyl esters such as vinyl acetate and vinyl propionate; (meth)acrylic acid, maleic anhydride, (meth) ) unsaturated carboxylic acids such as methyl acrylate and ethyl (meth)acrylate and their esters; and vinylsilanes such as vinyltrimethoxysilane and γ-(meth)acryloyloxypropylmethoxysilane. The polymer block (a2) may be a copolymer (particularly a random copolymer) of these other unsaturated monomers and aromatic vinyl monomers. The content of diene- and/or olefin-derived units in the polymer block (a2) is preferably 1% by mass or less, and the polymer block (a2) contains diene- and/or olefin-derived units. preferably not.

The polymer block (a2) preferably contains units derived from an aromatic vinyl monomer as a main component. Specifically, the content of units derived from the aromatic vinyl monomer in the polymer block (a2) is preferably 70% by mass or more, more preferably 80% by mass or more, and further preferably 90% by mass or more. preferable. The polymer block (a2) may be substantially composed only of units derived from aromatic vinyl monomers, for example, the content of units derived from aromatic vinyl monomers is 99% by mass or more. good too.

Examples of the polymer chain (A) composed of the polymer block (a1) and the polymer block (a2) include a styrene-butadiene block copolymer, a styrene-butadiene-styrene block copolymer, a styrene-butadiene- Hydrogenated products of styrene block copolymers (e.g., styrene-ethylene/butylene-styrene block copolymers (SEBS), styrene-butadiene/butylene-styrene block copolymers), styrene-isoprene block copolymers, styrene- Examples include isoprene-styrene block copolymers and hydrogenated styrene-isoprene-styrene block copolymers (eg, styrene-ethylene/propylene-styrene block copolymers (SEPS)). Moreover, in these block copolymers, those in which a butadiene block has become a butadiene/styrene block, and those in which an isoprene block has become an isoprene/styrene block can be mentioned. In the notation, each block is separated by "-", and the notation of "/" in each block represents a monomer unit constituting the block.

The polymer chain (A) is preferably a polymer block (a1) having polymer blocks (a2) bound to both sides thereof. Thereby, the polymer chain (A) functions as an elastomer, and the mechanical strength of the copolymer (P) can be further enhanced. In this case, the polymer chain (A) may be a triblock copolymer, a multiblock copolymer, or a radial block copolymer. A triblock copolymer is preferred because it is easy to control properties and easy to introduce the polymer chain (B) into the copolymer (P). Such copolymers include styrene-butadiene-styrene block copolymers and hydrogenated products thereof, styrene-isoprene-styrene block copolymers and hydrogenated products thereof, and the like.

The content of the polymer block (a2) in the polymer chain (A) is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and preferably 55% by mass or less. , 50% by mass or less is more preferable, 45% by mass or less is even more preferable, 35% by mass or less is particularly preferable, and 25% by mass or less is most preferable. As a result, the polymer chain (A) has a well-balanced soft component and hard component, which facilitates increasing the mechanical strength of the copolymer (P). From the same viewpoint, the content of the polymer block (a1) in the polymer chain (A) is preferably 45% by mass or more, more preferably 50% by mass or more, still more preferably 55% by mass or more, and 65% by mass. % or more is particularly preferable, 75 mass % or more is most preferable, 95 mass % or less is preferable, 90 mass % or less is more preferable, and 85 mass % or less is even more preferable. In the polymer chain (A), the content of units derived from the aromatic vinyl monomer is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, and 55% by mass or more. % by mass or less is preferable, 50% by mass or less is more preferable, 45% by mass or less is even more preferable, 35% by mass or less is particularly preferable, and 25% by mass or less is most preferable.

The weight average molecular weight of the polymer chain (A) is preferably 10,000 or more, more preferably 50,000 or more, still more preferably 10,000 or more, even more preferably 30,000 or more, and preferably 300,000 or less, 250,000 or less is more preferable, and 200,000 or less is even more preferable. By setting the weight average molecular weight of the polymer chain (A) to such a range, it becomes easy to secure the mechanical strength of the copolymer (P) and improve the molding processability of the copolymer (P). .

The polymer chain (B) has at least units derived from (meth)acrylic monomers (hereinafter sometimes referred to as “(meth)acrylic units”). Having the polymer chain (B) can enhance the transparency of the copolymer (P).

As used herein, the (meth)acrylic monomer is a monomer containing an acrylic group having a hydrogen atom or an alkyl group (preferably an alkyl group having 1 to 4 carbon atoms) bonded to the α-position and/or β-position. and at least part of the hydrogen atoms of the alkyl group may be substituted with a hydroxy group or a halogen group. A (meth)acrylic monomer preferably means a monomer having an acrylic group or a methacrylic group. (Meth)acrylic monomers include (meth)acrylic acid (ie, free acid) and derivatives thereof, including esters, salts, acid amides, and the like.

As the (meth)acrylic monomer, a (meth)acrylic acid ester is preferable. (Meth)acrylic acid esters include (meth)acrylic acid esters in which a linear, branched or cyclic aliphatic hydrocarbon group or aromatic hydrocarbon group is bonded to the oxygen atom of the ester bond of (meth)acrylic acid. is mentioned.

Examples of (meth)acrylic acid esters having a linear or branched aliphatic hydrocarbon group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, (meth)acryl isopropyl acid, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, amyl (meth)acrylate , isoamyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, (meth) ) alkyl (meth)acrylates such as dodecyl acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate and octadecyl (meth)acrylate. The alkyl group of the alkyl (meth)acrylate is preferably a C1-18 alkyl group, more preferably a C1-12 alkyl group, and still more preferably a C1-6 alkyl group. In this specification, the descriptions "C1-18" and "C1-12" mean "1 to 18 carbon atoms" and "1 to 12 carbon atoms", respectively.

Examples of (meth)acrylic acid esters having a cyclic aliphatic hydrocarbon group include (meth)acrylates such as cyclopropyl (meth)acrylate, cyclobutyl (meth)acrylate, cyclopentyl (meth)acrylate, and cyclohexyl (meth)acrylate. ) cycloalkyl acrylate; bridged cyclic (meth)acrylates such as isobornyl (meth)acrylate; The cycloalkyl group of cycloalkyl (meth)acrylate is preferably a C3-20 cycloalkyl group, more preferably a C4-12 cycloalkyl group, and still more preferably a C5-10 cycloalkyl group.

Examples of (meth)acrylic acid esters having an aromatic hydrocarbon group include phenyl (meth)acrylate, tolyl (meth)acrylate, xylyl (meth)acrylate, naphthyl (meth)acrylate, and binaphthyl (meth)acrylate. , aryl (meth)acrylates such as anthryl (meth)acrylate; aralkyl (meth)acrylates such as benzyl (meth)acrylate; aryloxyalkyl (meth)acrylates such as phenoxyethyl (meth)acrylate; mentioned. The aryl group of the aryl (meth)acrylate is preferably a C6-20 aryl group, more preferably a C6-14 aryl group. The aralkyl group of aralkyl (meth)acrylate is preferably a C6-10 aryl C1-4 alkyl group. The aryloxyalkyl group of the aryloxyalkyl (meth)acrylate is preferably a C6-10 aryloxy C1-4 alkyl group, more preferably a phenoxy C1-4 alkyl group.

The (meth)acrylic acid ester may have a substituent such as a hydroxy group, an amino group, a halogen group, an alkoxy group, an epoxy group, and the like. In particular, in (meth)acrylic acid esters having a linear or branched aliphatic hydrocarbon group, the aliphatic hydrocarbon group preferably has a hydroxy group, an amino group, a halogen group, an alkoxy group, an epoxy group, or the like. Such (meth)acrylic acid esters include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate; chloromethyl (meth)acrylate, 2-chloroethyl (meth)acrylate and the like ( alkoxyalkyl (meth)acrylates such as 2-methoxyethyl (meth)acrylate; epoxyalkyl (meth)acrylates such as glycidyl (meth)acrylate; and the like. The alkyl group of hydroxyalkyl (meth)acrylate and epoxyalkyl (meth)acrylate is preferably a C1-12 alkyl group, more preferably a C1-6 alkyl group. The alkoxyalkyl group of the alkoxyalkyl (meth)acrylate is preferably a C1-12 alkoxy C1-12 alkyl group, more preferably a C1-6 alkoxy group, and more preferably a C1-6 alkyl group.

The (meth)acrylic monomer also includes monomers exemplified by (meth)acrylic monomer A and (meth)acrylic monomer B having a protic hydrogen atom-containing group described later. .

The polymer chain (B) preferably has a ring structure in its main chain. That is, the polymer chain (B) preferably has a unit having a ring structure (hereinafter sometimes referred to as a "ring structure unit") in the main chain of the polymer chain (B). Having a ring structure in the main chain of the polymer chain (B) can enhance the transparency and heat resistance of the resin composition containing the copolymer (P). Improvements in solvent resistance, dimensional stability, surface hardness, adhesiveness, barrier properties against oxygen and water vapor, and various optical properties can also be expected. Furthermore, when a stretched film is obtained from the resin composition, it is also possible to develop a retardation derived from the ring structure of the polymer chain (B) depending on the stretching conditions.

The ring structure of the main chain of the polymer chain (B) may contain part or all of the (meth)acrylic monomer in the ring structure, and is introduced separately from the (meth)acrylic monomer. may be a ring structure. In this way, a component necessary for forming a ring structure in the main chain of the polymer chain (also referred to as a ring structure-forming monomer) is contained in the ring structure of a part or all of the (meth)acrylic monomer. In this case, for example, two carboxylic acid groups of adjacent (meth)acrylic monomer-derived units may be linked by acid anhydride formation, imidization, or the like. In addition, when one of the adjacent (meth)acrylic monomer-derived units has a protic hydrogen atom-containing group such as a hydroxy group or an amino group, this one (meth)acrylic monomer-derived unit A ring structure can also be formed by condensing the protic hydrogen atom-containing group of the unit with the carboxylic acid group of the other (meth)acrylic monomer-derived unit. When introducing a ring structure separately from a unit derived from a (meth)acrylic monomer, for example, a (meth)acrylic monomer and a monomer having a polymerizable double bond in the ring structure Copolymerization is sufficient.

The ring structure may be any of a 4-membered ring structure, a 5-membered ring structure, a 6-membered ring structure, a 7-membered ring structure, an 8-membered ring structure, etc., preferably a 5-membered ring structure or a 6-membered ring structure.

As the ring structure, from the viewpoint of heat resistance of the copolymer (P), a lactone ring structure, a lactam ring structure, a cyclic imide structure (e.g., succinimide structure, glutarimide structure, etc.), a cyclic anhydride structure (e.g., succinic anhydride acid structure, glutaric anhydride structure, etc.). One type of these ring structures may be contained in the main chain of the polymer chain (B), or two or more types thereof may be contained. Among these, at least one selected from a lactone ring structure, a succinimide structure, a succinic anhydride structure, a glutarimide structure, and a glutaric anhydride structure is preferred, and a lactone ring structure is more preferred.

When the polymer chain (B) has a lactone ring structure or lactam ring structure as the ring structure of the main chain, the number of ring members of the lactone ring structure or lactam ring structure is not particularly limited, for example, any one of a 4-membered ring to an 8-membered ring. If it is The lactone ring structure or lactam ring structure is preferably a 5-membered ring or a 6-membered ring, more preferably a 6-membered ring, from the viewpoint of excellent stability of the ring structure.

Examples of the lactone ring structure include structures disclosed in JP-A-2004-168882. coalescence), the lactone ring content in the cyclization condensation reaction of the precursor can be increased, and a polymer having a (meth)acrylate-derived unit can be used as a precursor. A structure represented by formula (1a) is preferably shown. As the lactam ring structure, a structure represented by the following formula (1b) is preferably shown. In formula (1a) or (1b) below, R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent.

Examples of substituents for R ¹ , R ² and R ³ in formulas (1a) and (1b) include organic residues such as hydrocarbon groups, for example, optionally substituted C1-20 and the like. Examples of the hydrocarbon group include saturated or unsaturated linear, branched or cyclic aliphatic hydrocarbon groups and aromatic hydrocarbon groups. Examples of aliphatic hydrocarbon groups include C1-20 alkyl groups (preferably C1-10 alkyl groups, more preferably C1-6 alkyl groups such as methyl group, ethyl group, n-propyl group and isopropyl group). group); C2-20 alkenyl groups (preferably C2-10 alkenyl groups, more preferably C2-6 alkenyl groups) such as ethenyl group and propenyl group; C3-20 cycloalkyl groups such as cyclopentyl group and cyclohexyl group groups (preferably C4-12 cycloalkyl groups, more preferably C5-8 cycloalkyl groups), and the like. Examples of the aromatic hydrocarbon group include C6-20 aryl groups (preferably C6-14 aryl groups, more preferably C6-10 aryl groups such as phenyl, tolyl, xylyl, naphthyl, and biphenyl groups). aryl group); C7-20 aralkyl groups (preferably C7-15 aralkyl groups, more preferably C7-11 aralkyl groups) such as benzyl group and phenylethyl group; These hydrocarbon groups may contain an oxygen atom or a halogen atom, and specifically, one or more of the hydrogen atoms possessed by the hydrocarbon group are selected from a hydroxy group, a carboxy group, an ether group and an ester group. It may be substituted with at least one group.

In the lactone ring structure of formula (1a) or the lactam ring structure of ^formula ( ^1b ), it is easy to obtain a copolymer (P) having excellent heat resistance and a small birefringence. Each independently represents a hydrogen atom or a C1-20 alkyl group, R ³ preferably represents a hydrogen atom or a methyl group, R ¹ and R ² each independently represents a hydrogen atom or a methyl group, and R ³ A hydrogen atom or a methyl group is more preferable.

A protic hydrogen atom-containing group of a unit derived from a (meth)acrylic monomer A having a protic hydrogen atom-containing group such as a hydroxy group or an amino group, and a unit derived from the (meth)acrylic monomer A A lactone ring structure and/or a lactam ring structure can be introduced into the polymer chain (B) by cyclocondensation with an ester group of an adjacent (meth)acrylic acid ester-derived unit. As a polymerization component, a (meth)acrylic monomer A having a protic hydrogen atom-containing group such as a hydroxy group or an amino group is essential, and a (meth)acrylic monomer B includes the monomer A. do. Monomer B may or may not be identical to monomer A. When monomer B matches monomer A, it results in homopolymerization of monomer A.

Examples of the (meth)acrylic monomer A1 having a hydroxy group include 2-(hydroxymethyl)acrylic acid, 2-(hydroxyethyl)acrylic acid, alkyl 2-(hydroxymethyl)acrylate (e.g., 2-(hydroxy methyl)methyl acrylate, 2-(hydroxymethyl)ethyl acrylate, 2-(hydroxymethyl)isopropyl acrylate, 2-(hydroxymethyl)n-butyl acrylate, 2-(hydroxymethyl)t-butyl acrylate) , 2-(hydroxyethyl)alkyl acrylate (e.g., methyl 2-(hydroxyethyl)acrylate, ethyl 2-(hydroxyethyl)acrylate), etc., preferably a monomer having a hydroxyallyl moiety 2-(hydroxymethyl)acrylic acid and alkyl 2-(hydroxymethyl)acrylates. Particularly preferred are methyl 2-(hydroxymethyl)acrylate and ethyl 2-(hydroxymethyl)acrylate.

Examples of the (meth)acrylic monomer A2 having an amino group include compounds in which the hydroxy group of the monomer A1 is changed to an amino group. When the polymer chain (B) has a lactone ring structure and/or a lactam ring structure, the (meth)acrylic monomer A serves as a ring structure-forming monomer.

As the (meth)acrylic monomer B, a monomer having a vinyl group and an ester group or a carboxy group is preferable. methyl acid, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, cyclohexyl (meth)acrylate, etc.), aryl (meth)acrylate (e.g., phenyl (meth)acrylate, benzyl (meth)acrylate, etc.), alkyl 2-(hydroxyalkyl)acrylates (e.g., methyl 2-(hydroxymethyl)acrylate, ethyl 2-(hydroxymethyl)acrylate) 2-(hydroxymethyl)alkyl acrylate such as, 2-(hydroxyethyl)alkyl acrylate such as methyl 2-(hydroxyethyl)acrylate), and the like.

The polymer chain (B) may have only one type of lactone ring structure or lactam structure represented by formula (1a) or formula (1b), or may have two or more types.

When the polymer chain (B) has a succinic anhydride structure (that is, a structure derived from a maleic anhydride monomer) or a succinimide structure (that is, a structure derived from a maleimide monomer) as the ring structure of the main chain, succinic anhydride As the structure or succinimide structure, the structure represented by the following formula (2) is preferably shown. In the following formula (2), R ⁴ and R ⁵ each independently represent a hydrogen atom or a methyl group, R ⁶ represents a hydrogen atom or a substituent, X ¹ represents an oxygen atom or a nitrogen atom, and X ¹ is an oxygen atom, n1=0, and when X1 is a nitrogen atom, n1= ¹ .

Examples of the substituent for R ⁶ in formula (2) include organic residues such as hydrocarbon groups, such as C1-20 hydrocarbon groups optionally having substituents. Examples of the hydrocarbon group include saturated or unsaturated linear, branched or cyclic aliphatic hydrocarbon groups and aromatic hydrocarbon groups. Examples of aliphatic hydrocarbon groups include C1-20 alkyl groups (preferably C1-10 alkyl groups, more preferably C1-6 alkyl groups such as methyl group, ethyl group, n-propyl group and isopropyl group). group); C2-20 alkenyl groups (preferably C2-10 alkenyl groups, more preferably C2-6 alkenyl groups) such as ethenyl group and propenyl group; C3-20 cycloalkyl groups such as cyclopentyl group and cyclohexyl group groups (preferably C4-12 cycloalkyl groups, more preferably C5-8 cycloalkyl groups), and the like. Examples of the aromatic hydrocarbon group include C6-20 aryl groups (preferably C6-14 aryl groups, more preferably C6-10 aryl groups such as phenyl, tolyl, xylyl, naphthyl, and biphenyl groups). aryl group); C7-20 aralkyl groups (preferably C7-15 aralkyl groups, more preferably C7-11 aralkyl groups) such as benzyl group and phenylethyl group; These hydrocarbon groups may have a substituent such as halogen.

When X ¹ is an oxygen atom, the ring structure represented by formula (2) is a succinic anhydride structure. A succinic anhydride structure can be introduced into the polymer chain (B) by, for example, copolymerizing maleic anhydride and a (meth)acrylic monomer (e.g., (meth)acrylic acid ester, etc.). . When the polymer chain (B) has a succinic anhydride structure, maleic anhydride is the ring structure-forming monomer.

When X ¹ is a nitrogen atom, the ring structure represented by formula (2) is a succinimide structure. A succinimide structure can be introduced into the polymer chain (B), for example, by copolymerizing an N-substituted maleimide and a (meth)acrylic monomer (eg, (meth)acrylate). The succinimide structure includes, for example, a succinimide structure in which the N-position is unsubstituted, an N-methylsuccinimide structure, an N-ethylsuccinimide structure, an N-cyclohexylsuccinimide structure, an N-phenylsuccinimide structure, an N-naphthylsuccinimide structure, and an N-benzylsuccinimide structure. structure and the like. As the maleimide giving a succinimide structure, N-unsubstituted maleimide, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-naphthylmaleimide, N-benzylmaleimide and the like are used. be able to. When the polymer chain (B) has a succinimide structure, the N-substituted maleimide serves as a ring structure-forming monomer.

^When the polymer chain ⁽ B) has a succinimide structure in which X ¹ is a nitrogen atom, it is easy to obtain a copolymer (P) having excellent heat resistance and a small birefringence. is a hydrogen atom, R ⁶ is preferably a C3-20 cycloalkyl group or a C6-20 aromatic group (aryl group, aralkyl group, etc.), R ⁴ and R ⁵ are hydrogen atoms, and R ⁶ is cyclohexyl more preferably a group or a phenyl group.

The polymer chain (B) may have only one type of ring structure represented by formula (2), or may have two or more types.

When the polymer chain (B) has a glutarimide structure or glutaric anhydride structure as the ring structure of the main chain, the glutarimide structure or glutaric anhydride structure is preferably represented by the following formula (3). In the following formula (3), R ⁷ and R ⁸ each independently represent a hydrogen atom or an alkyl group, R ⁹ represents a hydrogen atom or a substituent, X ² represents an oxygen atom or a nitrogen atom, and X ² is an oxygen atom, n2= ⁰ , and when X2 is a nitrogen atom, n2=1.

In formula (3), the alkyl group for R ⁷ and R ⁸ is preferably a linear or branched alkyl group, such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl C1-8 group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, n-hexyl group, isohexyl group, n-heptyl group, isoheptyl group, n-octyl group, 2-ethylhexyl group, etc. An alkyl group and the like can be mentioned. From the viewpoint of facilitating the production of a copolymer (P) having excellent heat resistance and a small birefringence index, each of R ⁷ and R ⁸ is preferably independently a hydrogen atom or a C1-4 alkyl group. Atoms or methyl groups are more preferred.

Examples of the substituent for R ⁹ in formula (3) include organic residues such as hydrocarbon groups, such as C1-20 hydrocarbon groups optionally having substituents. Examples of the hydrocarbon group include saturated or unsaturated linear, branched or cyclic aliphatic hydrocarbon groups and aromatic hydrocarbon groups. Examples of aliphatic hydrocarbon groups include C1-20 alkyl groups (preferably C1-10 alkyl groups, more preferably C1-6 alkyl groups such as methyl group, ethyl group, n-propyl group and isopropyl group). group); C2-20 alkenyl groups (preferably C2-10 alkenyl groups, more preferably C2-6 alkenyl groups) such as ethenyl group and propenyl group; C3-20 cycloalkyl groups such as cyclopentyl group and cyclohexyl group groups (preferably C4-12 cycloalkyl groups, more preferably C5-8 cycloalkyl groups), and the like. Examples of the aromatic hydrocarbon group include C6-20 aryl groups (preferably C6-14 aryl groups, more preferably C6-10 aryl groups such as phenyl, tolyl, xylyl, naphthyl, and biphenyl groups). aryl group); C7-20 aralkyl groups (preferably C7-15 aralkyl groups, more preferably C7-11 aralkyl groups) such as benzyl group and phenylethyl group; These hydrocarbon groups may have a substituent such as halogen. Among these, R ⁹ is preferably an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group because it is easy to obtain a copolymer (P) having excellent heat resistance and a small birefringence. A methyl group, a cyclohexyl group, a phenyl group, or a tolyl group is more preferred.

When X ² is an oxygen atom, the ring structure represented by formula (3) is a glutaric anhydride structure. The glutaric anhydride structure can be introduced into the polymer chain (B) by, for example, anhydrideizing two carboxylic acid groups of adjacent (meth)acrylic monomer-derived units.

When X ² is a nitrogen atom, the ring structure represented by formula (3) is a glutarimide structure. The glutarimide structure, for example, imidizes two carboxylic acid groups of adjacent (meth)acrylic monomer-derived units, or amide groups and (meth) It can be introduced into the polymer chain (B) by cyclic condensation with an ester group of a unit derived from an acrylic acid ester. When the polymer chain (B) has a glutarimide structure, the (meth)acrylic monomer becomes the ring structure-forming monomer.

When the ring structure of formula (3) has a ^glutarimide structure in which X ² is a nitrogen atom, it is easy to obtain a copolymer (P) having excellent heat resistance and a small birefringence. and R ⁸ are each independently a hydrogen atom or a methyl group, R ⁹ is more preferably a methyl group, a cyclohexyl group, a phenyl group, or a tolyl group, and R ⁷ and R ⁸ are each independently hydrogen It is particularly preferred that R 9 is an atom or a methyl group and that R ⁹ is a cyclohexyl group or a phenyl group.

The polymer chain (B) may have only one type of ring structure represented by formula (3), or may have two or more types.

Among the ring structures described above, the polymer chain (B) is preferred from the viewpoint of imparting good surface hardness, solvent resistance, adhesiveness, barrier properties, and optical properties to the resin composition containing the copolymer (P). The ring structural unit preferably contains a lactone ring structure and/or a succinimide structure (a structure derived from a maleimide monomer), more preferably a lactone ring structure.

The content of the cyclic structural unit of the main chain in the polymer chain (B) is not particularly limited, but the content of the cyclic structural unit in the polymer chain (B) is preferably 3% by mass or more, more preferably 4% by mass or more. , more preferably 5% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. By adjusting the content of the cyclic structural unit in the main chain in this manner, both heat resistance and mechanical strength can be imparted in a well-balanced manner to the resin composition containing the copolymer (P). When imparting higher heat resistance and mechanical strength to the resin composition, the content of the structural unit in the polymer chain (B) is preferably 10% by mass or more, more preferably 15% by mass or more. It is preferably 20% by mass or more, and more preferably 20% by mass or more. The content ratio of the cyclic structural unit described here means the content ratio of units having a cyclic structure contained in the main chain of the polymer chain (B), and is represented by the above formulas (1) to (3), for example. means the content ratio of the structure

The polymer chain (B) may further have units derived from a vinyl monomer copolymerizable with the (meth)acrylic monomer. The vinyl monomer copolymerizable with the (meth)acrylic monomer is not particularly limited as long as it is a compound having a polymerizable double bond. Examples include vinyl esters such as vinyl acetate and vinyl propionate; styrene; aromatic vinyl compounds such as vinyltoluene, methoxystyrene, α-methylstyrene and 2-vinylpyridine; and vinylsilanes such as vinyltrimethoxysilane and γ-(meth)acryloyloxypropylmethoxysilane. For example, if the polymer chain (B) has an aromatic vinyl monomer-derived unit, it becomes easy to adjust the refractive index and retardation properties of the copolymer (P). For details of the aromatic vinyl monomer, refer to the description of the aromatic vinyl monomer of the polymer chain (A). In addition, when the polymer chain (B) is formed from two or more monomer components, the polymer chain (B) is preferably a random copolymer.

Units derived from a vinyl monomer copolymerizable with the (meth)acrylic monomer are, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more in 100 parts by mass of the polymer chain (B) , more preferably 1 part by mass or more, for example, 30 parts by mass or less, preferably 20 parts by mass or less, more preferably 10 parts by mass or less.

Copolymer (P) is preferably a graft copolymer in which polymer chain (B) is grafted to polymer chain (A). According to the glossary of basic terms in polymer science by the International Union of Pure and Applied Chemistry (IUPAC) Committee on Polymer Nomenclature, a graft polymer is defined as "a If there is one or several blocks and these side chains have structural (chemical structure) or configurational features different from the main chain, the polymer is called a graft polymer.” there is The graft copolymer can be obtained by known production methods such as chain transfer reaction method, polymer initiator method, coupling method, macromonomer method and surface graft method, and only one of these methods is adopted. may be used, or a plurality of them may be used in combination. For details of these methods, reference can be made to Kagaku Binran (Applied Chemistry), 6th edition, edited by the Chemical Society of Japan.

In the copolymer (P), the polymer chain (B) is more preferably grafted to the polymer block (a1) of the polymer chain (A), and the polymer chain (B) is grafted onto the polymer block (a1) is most preferably attached to diene- and/or olefin-derived units of In this most preferred case, the polymer chain (B) may be attached to the carbon atoms of the main chain of the diene- and/or olefin-derived units, and the hydrocarbon groups attached to said main chain as substituents (side chains) may be attached to the carbon atom of The polymer chain (B) may be bonded, for example, to a diene-derived double bond in the main chain of the copolymer block (a1), or may be bonded to a carbon atom adjacent to the double bond. Alternatively, the polymer chain (B) is bonded to a diene-derived double bond bonded as a substituent (side chain) to the main chain of the copolymer block (a1), or bonded to the carbon atom adjacent to the double bond. You may have

2. 2. Production method of copolymer (P) 2.1 Production raw materials, reagents In the presence of a copolymer (P1) having a polymer block (a2) having It can be produced by polymerizing a monomer component containing a raw (meth)acrylic monomer). The starting copolymer (P1) corresponds to the polymer chain (A), and the polymer of the starting (meth)acrylic monomer constitutes the polymer chain (B).

The method for producing the starting copolymer (P1) is not particularly limited. For example, after polymerizing the monomer components constituting the polymer block (a1) to form the polymer block (a1), the polymer block ( It can be obtained by polymerizing the monomer components constituting the polymer block (a2) in the presence of a1). The starting copolymer (P1) may be hydrogenated. Moreover, you may combine 1 type(s) or 2 or more types. When two or more types are combined, it becomes easy to adjust the average molecular weight and the amount of double bonds as a resin composition.

The amount of olefinic double bonds in the starting copolymer (P1) is preferably 0.2 mmol/g or more and 2.0 mmol/g or less. By using the starting copolymer (P1) having an olefinic double bond content of 0.2 mmol/g or more, it becomes easier to obtain the copolymer (P) with high transparency. On the other hand, by using the starting copolymer (P1) having an olefinic double bond content of 2.0 mmol/g or less, it becomes easier to obtain the copolymer (P) with less gelation. The amount of olefinic double bonds in the starting copolymer (P1) is more preferably 0.4 mmol/g or more, still more preferably 0.6 mmol/g or more, and more preferably 1.5 mmol/g or less. 2 mmol/g or less is more preferable, and 1.0 mmol/g or less is particularly preferable. The raw material copolymer (P1) may contain a plurality of (co)polymers having different olefinic double bond amounts, and some of the (co)polymers have an olefinic double bond amount of 2.5. Although it may exceed 0 mmol/g, it is preferable that the amount of olefinic double bonds in the entire starting copolymer (P1) is 2.0 mmol/g or less. The amount of olefinic double bonds in the starting copolymer (P1) can be determined by an iodine titration method.

As the starting material (meth)acrylic monomer, the (meth)acrylic monomers described for the polymer chain (B) can be appropriately used. Also, a vinyl monomer copolymerizable with the (meth)acrylic monomer may be present together with the raw material (meth)acrylic monomer, and these may be copolymerized. In addition, components necessary for forming a ring structure in the main chain of the polymer chain (B) (ring structure-forming monomers), for example, protic hydrogen atom-containing components for forming a lactone ring structure or a lactam ring structure (Meth)acrylic monomer A and (meth)acrylic monomer B having a group, a monomer having a polymerizable double bond in the ring structure (maleic anhydride for forming a succinic anhydride structure , maleimide for forming a succinimide structure, etc.), and at least one selected from (meth)acrylic acid for forming a glutaric anhydride structure or a glutarimide structure as the starting (meth)acrylic monomer, Alternatively, it can be used as a copolymerization component of raw (meth)acrylic monomers.

The amount of the raw material copolymer (P1) used during polymerization is the same as the raw material copolymer (P1) and the monomer component (raw material (meth)acrylic monomer, raw material (meth)acrylic monomer). Polymerizable vinyl monomer, ring structure-forming monomer, etc.) is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, with respect to a total of 100 parts by mass. It is more preferably 9 parts by mass or more, more preferably 50 parts by mass or less, more preferably 40 parts by mass or less, still more preferably 30 parts by mass or less, and particularly preferably 20 parts by mass or less. The amount of the monomer component used is preferably 50 parts by mass or more, more preferably 60 parts by mass or more, and more preferably 70 parts by mass or more with respect to a total of 100 parts by mass of the starting copolymer (P1) and the monomer component. It is more preferably 80 parts by mass or more, particularly preferably 99 parts by mass or less, more preferably 97 parts by mass or less, even more preferably 95 parts by mass or less, and even more preferably 93 parts by mass or less.

Examples of the radical polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis(2-amidinopropane) dihydrochloride, dimethyl-2,2′-azobis(2- methyl propionate), azo compounds such as 4,4′-azobis (4-cyanopentanoic acid); persulfates such as potassium persulfate; cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butylperoxide oxide, lauroyl peroxide, benzoyl peroxide, t-butyl peroxyisopropyl carbonate (TBIC), t-amyl peroxy-2-ethylhexanoate, t-amyl peroxyoctoate, t-amyl peroxy isononanoate (TAIN), t-amylperoxyisopropyl carbonate, t-amylperoxy-2-ethylhexyl carbonate, and other organic peroxides can be used. These may use only 1 type and may use 2 or more types together. Among these, organic peroxides are preferred. Organic peroxides are particularly useful when the starting copolymer (P1) is a hydrogenated product. According to the organic peroxide, the double bond (olefinic double bond) possessed by the olefin-derived unit can be abstracted from highly active hydrogen such as at the vinyl position and allyl position to generate radicals at such positions, and the polymer chain (B ) is useful for addition polymerization of the monomer component forming the The amount of the radical polymerization initiator to be used is preferably 0.01 to 1 part by weight per 100 parts by weight of the monomer component.

The polymerization can be carried out using known polymerization methods such as bulk polymerization method, solution polymerization method, emulsion polymerization method and suspension polymerization method, but solution polymerization method is preferably used. If the solution polymerization method is used, it is possible to suppress contamination of the copolymer (P) with minute foreign matter, and the copolymer (P) can be suitably applied to optical material applications and the like.

The solvent used for solution polymerization can be appropriately selected according to the composition of the monomer components, and organic solvents used in ordinary radical polymerization reactions can be used. Specifically, aromatic hydrocarbons such as toluene, xylene and ethylbenzene; aliphatic hydrocarbons such as hexane and cyclohexane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; tetrahydrofuran, dioxane and ethylene glycol dimethyl ether. , diethylene glycol dimethyl ether, ethers such as anisole; esters such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate; cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve; methanol, ethanol, isopropanol, alcohols such as n-butanol; nitriles such as acetonitrile, propionitrile, butyronitrile and benzonitrile; chloroform; These solvents may be used alone or in combination of two or more.

2.2 Addition procedure As a method for producing the resin composition of the present invention, the raw material copolymer (P1), the raw material (meth)acrylic monomer, and the radical polymerization initiator are allowed to coexist to initiate a radical polymerization reaction. and a step of adding a radical polymerization initiator to the reaction solution after the initiation of the radical polymerization reaction. By additionally adding a radical polymerization initiator after the start of the radical polymerization reaction, the composition distribution of the polymer chain (B) can be reduced, and the reaction rate between the raw material copolymer (P1) and the (meth)acrylic monomer can be improved, the aggregation phenomenon of the obtained copolymer (P) can be reduced, and the decrease in transparency of the resin composition containing the copolymer (P) under heating conditions can be prevented. Hereinafter, the mixture of the raw material copolymer (P1), the raw material (meth)acrylic monomer, and the radical polymerization initiator until the radical polymerization reaction starts is referred to as the "initial mixture", and the mixture after the radical polymerization reaction starts. The reaction mixture (reaction liquid) may be referred to as "reaction continuation liquid".

The preparation procedure of the initial mixture is not particularly limited. A radical polymerization initiator may be added to the mixture with the (meth)acrylic monomer. Further, the temperature control until the radical polymerization starts can be set as appropriate. A radical polymerization initiator may be added to the mixture to initiate the radical polymerization reaction.

The addition of the radical polymerization initiator to the reaction solution (reaction continuation solution) after the radical polymerization reaction has started may be carried out continuously without interruption from the addition of the radical polymerization initiator for preparing the initial mixture. However, after adding the radical polymerization initiator for preparation of the initial mixture, it is preferable to temporarily stop the addition and restart the addition of the radical polymerization initiator after the radical polymerization reaction has started. By temporarily stopping the addition, it becomes possible to re-add after confirming the start of the radical polymerization reaction, and the radical reaction can be carried out safely. The initiation of the radical polymerization reaction can be confirmed by confirming the components by sampling or the like, and by changes in the properties and temperature of the liquid.

Addition of the radical polymerization initiator to the reaction continuation liquid may be either divided addition or dropping (including continuous dropping). Also, the number of additions when adding in portions is not particularly limited as long as it is two or more times, and each addition may be performed dropwise. In order to improve the conversion rate of the monomer component, preferably a radical polymerization initiator is dropped, more preferably continuously dropped. The dropping rate is, for example, about 0.1 to 1.0 parts by mass/minute, preferably 0.1 to 0.8 parts by mass when the total amount of the radical polymerization initiator used until the end of the reaction is 100 parts by mass. It is about part/minute, more preferably about 0.2 to 0.5 parts by mass/minute. The completion of the reaction can be confirmed by measuring the conversion, and is defined as the point when the conversion of all monomers reaches 85% or more.

The amount of the radical polymerization initiator added to the reaction continuation liquid is, for example, 30 to 500 parts by mass, preferably 100 to 450 parts by mass, with respect to 100 parts by mass of the radical polymerization initiator added to the initial mixture. and more preferably 150 to 350 parts by mass.

The starting copolymer (P1) may be added to the reaction continuation liquid (divided addition, dropwise addition, etc.), but it is preferable not to add it. Without addition, the reaction rate between the starting copolymer (P1) and the (meth)acrylic monomer can be increased. The amount of the raw material copolymer (P1) added to the reaction continuation liquid is, for example, 0 to 100 parts by mass with respect to 100 parts by mass of the raw material copolymer (P1) added to the initial mixture, and is preferably. is 0 to 50 parts by mass, more preferably 0 part by mass.

The raw material (meth)acrylic monomer may be added (divided addition, dropwise addition, etc.) to the reaction continuation liquid, or may not be added. Whether or not it is added to the reaction continuation solution can be determined by comparing the reactivity with the copolymer components. The reactivity with the copolymer component is represented by r ₁ and r ₂ values, and if the Q value and e value of the component are known, each value can be considered, or experimentally, the intersection method, Finerman- A Ross method or the like is used. For details, refer to Chemistry of Polymer Synthesis (written by Takayuki Otsu). For example, when the copolymerization component is an aromatic vinyl monomer, it is preferable not to add the starting (meth)acrylic monomer to the reaction continuation solution or to reduce the amount of addition in consideration of the r ₁ and r ₂ values. There is also The addition to the reaction continuation liquid allows the copolymerization component to be formed with a uniform composition having a small composition distribution, and the transparency of the resulting resin composition comprising the polymer can be improved. When the copolymerization component is an aromatic vinyl monomer, it is better to reduce the amount of addition of the reaction continuation liquid of the raw (meth)acrylic monomer (especially not to add). can increase the conversion rate of In addition, the composition distribution of the polymer chain (B) can be narrowed when the aromatic vinyl monomer is copolymerized, the dispersion stability of the copolymer (P) can be improved, and the decrease in transparency under heating conditions can be prevented. more preventable. When the copolymerization component is an aromatic vinyl monomer, the amount of the raw (meth)acrylic monomer added to the reaction continuation liquid is 100% of the amount of the raw (meth)acrylic monomer added to the initial mixture. For example, it is 0 to 50 parts by mass, preferably 0 to 30 parts by mass, and more preferably 0 to 10 parts by mass.

In this polymerization reaction, the (meth)acrylic monomer A having a protic hydrogen atom-containing group, the (meth)acrylic monomer B, and a monomer having a polymerizable double bond in the ring structure ( It is also possible to polymerize ring structure-forming monomers such as maleic anhydride, maleimide, etc.) and (meth)acrylic acid. These ring structure-forming monomers may be added to the initial mixture, or may be added to the reaction continuation solution (divided addition, dropwise addition, etc.). The ratio of the amount added to the initial mixture and the amount added to the reaction continuation liquid can be determined by comparing the reactivity with the copolymer components. For example, when the copolymer component is an aromatic vinyl monomer and the amount used is 15 parts by mass or less in 100 parts by mass of the total monomers, the ring structure-forming monomer is added to the initial mixture and the reaction is continued. It is preferable not to add it to the liquid or to reduce the amount of addition. When the copolymerization component is an aromatic vinyl monomer and the amount used exceeds 15 parts by mass based on 100 parts by mass of the total monomers, the ring-forming component is preferably added to the initial mixture and the reaction continuation solution. . By adjusting the ratio of the amount added to the initial mixture and the amount added to the reaction continuation liquid in this way, the conversion rate of the ring structure-forming monomer can be increased, and as described above, the (meth)acrylic monomer The composition distribution of the polymer chain (B) can be reduced when the polymer and the aromatic vinyl monomer are reacted, and the dispersion stability of the (meth)acrylic block copolymer (P) can be increased. It is possible to further prevent a decrease in transparency at The amount of the ring structure-forming monomer added to the initial mixture when the aromatic vinyl monomer is reacted is, for example, 20 parts by mass with respect to 100 parts by mass of the total amount of the ring structure-forming monomer added. or more, preferably 30 parts by mass or more, more preferably 40 parts by mass or more, and most preferably 100 parts by mass.

In this polymerization reaction, a vinyl monomer (which does not contain a ring structure-forming monomer) may be copolymerized with the starting (meth)acrylic monomer. The vinyl monomer may be added to the initial mixture or to the reaction continuation liquid (divided addition, dropwise addition, etc.). The ratio of the amount added to the initial mixture and the amount added to the reaction continuation liquid can be determined by comparing the reactivity of the starting (meth)acrylic monomer and the vinyl monomer. When the vinyl monomer is an aromatic vinyl monomer, it is preferably added to the reaction continuation solution while it is not added to the initial mixture or is added in a reduced amount. By increasing the amount added in the reaction continuation liquid, the composition distribution of the polymer chain (B) can be made smaller when the aromatic vinyl monomer is copolymerized, and the dispersion stability of the copolymer (P) can be improved. It is possible to further prevent deterioration of transparency under heating conditions. The amount of the vinyl monomer added to the reaction continuation liquid is, for example, 70 parts by mass or more, preferably 80 parts by mass or more, more preferably 100 parts by mass of the total added amount of the vinyl monomer. It is 90 parts by mass or more, most preferably 100 parts by mass.

In the polymerization reaction, a chain transfer agent may be added to at least one of the initial mixture and the reaction continuation liquid, preferably the initial mixture. The molecular weight distribution can be narrowed by using a chain transfer agent. Chain transfer agents include butanethiol, octanethiol, octadecanethiol, dodecanethiol, cyclohexylmercaptan, thiophenol, octyl thioglycolate, octyl 2-mercaptopropionate, octyl 3-mercaptopropionate, and 2-ethylhexyl mercaptopropionate. , octanoic acid 2-mercaptoethyl ester, 1,8-dimercapto-3,6-dioxaoctane, n-dodecyl mercaptan, ethylene glycol bisthioglycolate and other mercaptans; carbon tetrachloride, carbon tetrabromide, methylene chloride, Halogen compounds such as bromoform and bromotrichloroethane; α-methylstyrene dimer and the like. The amount of the chain transfer agent to be used is preferably 0.01 to 3 parts by weight per 100 parts by weight of all monomer components used in the initial mixture and reaction continuation solution.

2.3 Reaction conditions In the initial mixture, the raw material copolymer (P1) and the monomer (raw material (meth) acrylic monomer, ring structure-forming monomer, vinyl monomer, etc., especially raw material (meth) acrylic System monomer, ring structure-forming monomer) may be dissolved or dispersed in the solvent, and the total concentration of the starting copolymer (P1) and the monomer in the initial mixture is, for example, 10 to 80% by mass, preferably 30 to 70% by mass, more preferably 40 to 60% by mass.
The radical polymerization initiator added to the reaction continuation liquid may be dissolved or dispersed in the solvent, and the concentration of the radical polymerization initiator added to the reaction continuation liquid is, for example, 1 to 50% by mass, preferably 3 to 50% by mass. 30 mass %, more preferably 5 to 25 mass %.
Monomers (raw (meth)acrylic monomers, ring structure-forming monomers, vinyl monomers, especially aromatic vinyl monomers) to be added to the reaction continuation solution are dissolved or dispersed in the solvent. Alternatively, if it is a liquid, it may be added as it is without being mixed with a solvent.
The radical polymerization initiator and the monomers to be added to the reaction continuation liquid may be added separately to the reaction continuation liquid, or may be added to the reaction continuation liquid after mixing them first.

The reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen gas or under a stream of air. The reaction temperature is, for example, 50 to 200°C, preferably 70 to 150°C, more preferably 90 to 120°C. The reaction time is preferably 1 hour to 20 hours, for example. Further, it may include a step of aging after adding the radical polymerization initiator added to the initial mixture or after adding the radical polymerization initiator to the reaction continuation liquid, and the degree of progress of the polymerization reaction and the degree of formation of the gelled product may be determined. Adjust accordingly while watching. Assuming that the half-life of the radical polymerization initiator at the reaction temperature is t ₁ (hours), the aging time is preferably 0.1t ₁ to 3t ₁ (hours). If it is shorter than 0.1 t ₁ hour, the decomposition of the initiator is not sufficient, and if it is 3 t ₁ hour or more, decomposition of the radical polymerization initiator is almost eliminated, and unnecessary process time is provided, which may reduce productivity. . The aging temperature may be the same as the polymerization temperature at the time of addition of the radical polymerization initiator, or may be maintained at a temperature higher than the polymerization temperature at the time of addition.

The polymerization conversion rate in the polymerization reaction is 85% or more, that is, each monomer in the polymerization reaction (raw material (meth) acrylic monomer, raw material (meth) acrylic monomer and copolymerizable vinyl monomers, ring structure-forming monomers, etc.) are all 85% or more. By adjusting the polymerization conversion rate, the amount of olefinic double bonds in the resin composition can be adjusted. If the conversion rate of each monomer is lower than 85%, a separate facility for recovering the monomers will be required, or the residual monomers will cause unwanted reactions in the next step, resulting in gel formation. It can seriously impair productivity. The conversion rate of each monomer in the polymerization reaction is preferably as follows.
Conversion rate of raw material (meth)acrylic monomer: preferably 90% or more Conversion rate of vinyl monomer (excluding ring structure-forming monomer) copolymerizable with raw material (meth)acrylic monomer : preferably 90% or more, more preferably 95% or more Conversion rate of ring structure-forming monomer: preferably 90% or more, more preferably 94% or more

2.4 Devolatization step When a ring structure is not introduced into the polymer chain (B), after the above polymerization step, a post-treatment step including a devolatilization step is performed as necessary. Further, a monomer having a polymerizable double bond in the ring structure (preferably at least one selected from maleic anhydride and maleimide) is used as a ring structure-forming monomer to form a ring structure in the polymer chain (B). Also when introducing, a special cyclization step is not required, and after the polymerization step, a post-treatment step including a devolatilization step is performed as necessary.

In the devolatilization step, the solvent is removed by heating and/or reducing the pressure of the polymerization reaction solution containing the polymerization solvent. In the devolatilization step, an autoclave, a kettle-type reactor, an apparatus consisting of a heat exchanger and a devolatilization tank, a vented extruder, or the like can be used, and a dryer may be used.

When a vented extruder is used, the extruder preferably has a cylinder, a screw provided in the cylinder, and heating means. The cylinder is provided with one or more vents. The vent is preferably provided at least on the downstream side of the raw material charging section with respect to the transfer direction in the extruder, and may also be provided on the upstream side of the raw material charging section.

The polymerization reaction product fed into the extruder is kneaded with a screw while being transported from the upstream side to the downstream side of the extruder, and devolatilization progresses, and the copolymer (P) is discharged from the downstream side of the extruder. be. A die is preferably provided on the downstream side of the extruder, and by discharging the copolymer (P) from the die, it can be formed into a predetermined shape (film or rod). For example, pellets can be produced by finely cutting a rod-shaped copolymer.

2.5 Cyclization step (ring structure formation step) and devolatilization step On the other hand, the (meth)acrylic monomer A, the (meth)acrylic monomer B, and the (meth)acryl having a protic hydrogen atom-containing group When the polymer chain (B) is copolymerized using an acid or the like as a ring structure-forming monomer, a cyclization reaction (ring structure-forming step) is performed after the copolymerization reaction to obtain the polymer chain (B) A ring structure can be introduced into the main chain of Specifically, a condensation reaction occurs between reactive groups (ester group, —COOH group, —OH group, _—NH2 group) possessed by adjacent monomer units of the polymer chain (B) formed in the polymerization step. to form a ring structure in the main chain of the polymer chain (B). Cyclocondensation reactions include esterification reactions, amidation reactions, acid anhydride reactions, imidization reactions, and the like. For example, a glutaric anhydride structure can be formed by acid anhydride conversion of two carboxylic acid groups of adjacent (meth)acrylic units, and a glutarimide structure can be formed by imidization. When one of the adjacent (meth)acrylic units has a protic hydrogen atom-containing group such as a hydroxy group or an amino group, the protic hydrogen atom-containing group of one (meth)acrylic unit and the other ( A lactone or lactam ring structure can be formed by condensing the meth)acrylic unit with the carboxylic acid group.

In the ring structure forming step, the condensation reaction between reactive groups of adjacent monomer units is preferably carried out in the presence of a catalyst (cyclization catalyst). At least one selected from the group consisting of acids, bases and salts thereof can be used as the cyclization catalyst. Acids, bases and salts thereof may be organic or inorganic and are not particularly limited. Among them, it is preferable to use an organic phosphorus compound as a catalyst for the cyclization reaction. By using an organic phosphorus compound as a cyclization catalyst, the cyclization condensation reaction can be efficiently performed, and the resulting copolymer (P) can be less colored.

Organic phosphorus compounds that can be used as cyclization catalysts include, for example, alkyl(aryl)phosphonous acids and their monoesters or diesters; dialkyl(aryl)phosphinic acids and their esters; alkyl(aryl)phosphonic acids and their monoesters or diesters of; , lauryl phosphate, stearyl phosphate, isostearyl phosphate, phenyl phosphate, dimethyl phosphate, diethyl phosphate, di-2-ethylhexyl phosphate, diisodecyl phosphate, dilauryl phosphate, distearyl phosphate, di Phosphate monoesters, diesters or triesters such as isostearyl, diphenyl phosphate, trimethyl phosphate, triethyl phosphate, triisodecyl phosphate, trilauryl phosphate, tristearyl phosphate, triisostearyl phosphate, triphenyl phosphate; mono-, di- or tri-alkyl(aryl)phosphine; alkyl(aryl)halogenphosphine; mono-, di- or tri-alkyl(aryl)phosphine oxide; tetraalkyl(aryl)phosphonium halide and the like. These may use only 1 type and may use 2 or more types together. Among these, phosphoric acid monoesters and diesters are particularly preferred because of their high catalytic activity and low colorability. The amount of the cyclization catalyst used is preferably, for example, 0.001 to 1 part by mass with respect to 100 parts by mass of the copolymer obtained in the polymerization step.

The reaction temperature in the ring structure forming step is preferably 50°C to 300°C. The reaction time may be appropriately adjusted while observing the degree of progress of the cyclization condensation reaction, and is preferably carried out for, for example, 5 minutes to 6 hours.

The ring structure-forming step is preferably performed under heating. At this time, the polymerization solution containing the polymerization solvent obtained in the polymerization step may be heated as it is, the polymerization solvent may be devolatilized and then heated, or both of these may be combined. Reactors used for the cyclization condensation reaction include, for example, autoclaves, kettle-type reactors, devices comprising a heat exchanger and a devolatilization tank, extruders with vents, and the like.

Volatilization is preferably performed in the ring structure forming step. Volatilization can be performed by reducing the pressure in the reactor with a vacuum pump or the like. Volatilization can also be achieved by heating in an autoclave and then vacuum drying. The devolatilization removes the polymerization solvent used in the polymerization step and brought into the ring structure formation step, alcohol by-produced in the cyclization condensation reaction, etc., and reduces the residual volatile content in the resulting copolymer (P). can do. In addition, since the alcohol and the like by-produced in the cyclization condensation reaction are removed, the reaction equilibrium is inclined toward the production side, which is advantageous.

When the cyclization condensation reaction is performed while devolatilizing, the cyclization condensation reaction is preferably performed under reduced pressure from the viewpoint of efficient devolatilization. The pressure reduction in the cyclization condensation reaction is, for example, preferably 90 kPa or less, more preferably 80 kPa or less, and even more preferably 70 kPa or less, as an absolute pressure. On the other hand, the absolute pressure when reducing the pressure is preferably 0.1 kPa or more, more preferably 1 kPa or more, from the viewpoint that the equipment for realizing the reduced pressure state does not have excessive specifications and the equipment cost is kept low. When the cyclization condensation reaction is performed without devolatilization, the cyclization condensation reaction may be performed under normal pressure or under pressure.

When cyclizing while devolatilizing, it is preferable to use a vented extruder. The structure of the vented extruder is the same as that of the vented extruder used in the devolatilization step. The polymerization reaction product fed into the extruder is kneaded by a screw while being transported from the upstream side to the downstream side of the extruder while the cyclization condensation reaction progresses, and the copolymer (P) is produced from the downstream side of the extruder. Ejected. A die is preferably provided on the downstream side of the extruder, and by discharging the copolymer (P) from the die, it can be formed into a predetermined shape (film or rod). For example, pellets can be produced by finely cutting the rod-shaped copolymer (P).

When the cyclization-condensation reaction is performed in the presence of a cyclization catalyst in the ring structure-forming step, it is preferable to add a deactivator after or during the cyclization-condensation reaction. For example, when a resin composition containing a copolymer (P) is pelletized or formed into a film, if a cyclization catalyst remains in the resin composition, a cyclization condensation reaction occurs to generate alcohol or the like. As a result, undesirable foaming can occur. However, by adding a quenching agent after or during the cyclization condensation reaction, such foaming can be prevented.

As the deactivator, a substance capable of neutralizing the cyclization catalyst is preferably used. For example, when the cyclization catalyst is an acidic substance, a basic substance can be used as the deactivator, and conversely, when the cyclization catalyst is a basic substance, an acidic substance can be used as the deactivator. . As described above, an organic phosphorus compound is preferably used as the cyclization catalyst, and the compound is often an acidic substance. Therefore, it is preferable to use a basic substance as the deactivator. The basic substance is not particularly limited as long as it can stop the cyclization condensation reaction, and for example, metal carboxylates, metal complexes, metal oxides and the like are used. Conversely, when a basic substance is used as the cyclization catalyst, an acidic substance that can be used for the cyclization catalyst described above can be used as the deactivator.

The timing of adding the deactivator is preferably during the cyclization condensation reaction or after the reaction and before pelletizing or filming the resin composition containing the copolymer (P). For example, the deactivator may be added to the resin composition in a molten state, or the deactivator may be added to the resin composition dissolved in a solvent. When the cyclization condensation reaction is performed using an extruder as described above, the deactivator may be added to a position after the cyclization condensation reaction has sufficiently occurred in the extruder.

3. Resin Composition The resin composition of the present invention contains a (meth)acrylic polymer (Q) as a resin component (matrix resin) in addition to the copolymer (P). The (meth)acrylic polymer (Q) preferably has excellent compatibility with the copolymer (P). Inclusion of the (meth)acrylic polymer (Q) facilitates enhancing the transparency and heat resistance of the film.

The (meth)acrylic polymer (Q) may have a unit derived from the (meth)acrylic monomer described in the polymer chain (B) above, preferably the polymer chain (B ) has a unit derived from the (meth)acrylic acid ester described in ). The (meth)acrylic polymer (Q) may have units derived from other unsaturated monomers described in the polymer chain (B) above. The structural unit of the (meth)acrylic polymer (Q) is preferably the same as the structural unit of the polymer chain (B) from the viewpoint of enhancing compatibility with the copolymer (P).

The (meth)acrylic polymer (Q) preferably has a ring structure, and more preferably has a ring structure in its main chain. Thereby, the transparency and heat resistance of the film can be improved. The ring structure of the main chain of the (meth)acrylic polymer (Q) includes a lactone ring structure, a lactam ring structure, a cyclic imide structure (e.g., succinimide structure, glutarimide structure, etc.), a cyclic anhydride structure (e.g., anhydride succinic acid structure, glutaric anhydride structure, etc.), and the like, and the details of these ring structures are referred to the above description of the ring structure of the polymer chain (B). Among them, the (meth)acrylic polymer (Q) preferably has, in its main chain, the same ring structure as that of the polymer chain (B) of the copolymer (P).

The (meth)acrylic polymer (Q) has the same (meth)acrylic units as the (meth)acrylic units that the polymer chain (B) of the copolymer (P) has, and the ring that the polymer chain (B) has. It is preferred to have the same ring structural unit as the structural unit. This increases the compatibility between the (meth)acrylic polymer (Q) and the copolymer (P), making it easier to improve the transparency and heat resistance of the film.

Such a (meth)acrylic polymer (Q) is obtained by polymerizing a monomer for forming a polymer chain (B) separately from the starting copolymer (P1) when polymerizing the copolymer (P). It is convenient to polymerize them together in the same polymerization reaction system. In the method for producing the copolymer (P) described above, together with the copolymer (P), the (meth)acrylic polymer (Q) corresponding to the polymer chain (B) of the copolymer (P) is also produced at the same time. At this time, by not separating the copolymer (P) and the (meth)acrylic polymer (Q), a resin composition containing the copolymer (P) and the (meth)acrylic polymer (Q) can get things. The resin composition thus obtained, which substantially contains only the (meth)acrylic copolymer (Q) and the copolymer (P) as polymers, is hereinafter referred to as a "two-component mixture". There is In order to contain a polymer other than the (meth)acrylic polymer (Q) in the resin composition, the copolymer (P) may be isolated, or may be blended with another polymer without isolation. .

The content of the copolymer (P) in the resin composition is preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass or more, and even more preferably 15% by mass or more. It becomes easy to increase the mechanical strength of the resin molding. The upper limit of the content of the copolymer (P) in the resin composition is not particularly limited, and the resin composition may be composed only of the copolymer (P). The content of P) may be 90% by mass or less, 70% by mass or less, 50% by mass or less, 40% by mass or less, or 30% by mass or less.

The content of the polymer chain (A) of the copolymer (P) in the resin composition is preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass or more, and 50% by mass or less. is preferred, 40% by mass or less is more preferred, and 30% by mass or less is even more preferred. When the content of the polymer chain (A) in the resin composition is 1% by mass or more, the mechanical strength of the resin molding can be easily increased. If the content of the polymer chain (A) in the resin composition is 50% by mass or less, the transparency and heat resistance of the resin molding can be easily improved.

The content of the ring structural unit in 100% by mass of the solid content of the resin composition is not particularly limited, but is preferably 3% by mass or more, more preferably 4% by mass or more, further preferably 5% by mass or more, and 50% by mass. The following is preferable, 45% by mass or less is more preferable, and 40% by mass or less is even more preferable. By adjusting the content of the ring structural unit within the above range, it becomes easy to improve both the heat resistance and the mechanical strength of the resin composition in a well-balanced manner. The content ratio of the ring structural unit described here is the content ratio of the unit having a ring structure contained in the main chain of the polymer chain (B) of the copolymer (P) and the (meth)acrylic polymer ( It means the ring structure contained in the main chain of Q), for example, it means the content ratio of the structures represented by the above formulas (1) to (3).

The content of the (meth)acrylic polymer (Q) in the resin composition is preferably 1% by mass or more, more preferably 10% by mass or more, still more preferably 20% by mass or more, and even more preferably 30% by mass or more. It is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less. The total content of the (meth)acrylic polymer (Q) and the polymer chain (B) in the resin composition is preferably 30% by mass or more, more preferably 50% by mass or more, and further preferably 70% by mass or more. It is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 93% by mass or less.

The total content of the copolymer (P) and the (meth)acrylic polymer (Q) in the resin composition is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. , 90% by mass or more is even more preferable. The upper limit of the content ratio of the copolymer (P) and the (meth)acrylic polymer (Q) in the film is not particularly limited, and the film is substantially composed of the copolymer (P) and the (meth)acrylic polymer It may be composed only of (Q).

The resin composition of the present invention may contain a polymer other than the (meth)acrylic polymer (Q) described above. Examples of such polymers include polyethylene, polypropylene, ethylene- Olefin polymers such as propylene polymer and poly(4-methyl-1-pentene); halogen-containing polymers such as vinyl chloride and chlorinated vinyl resin; polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile Styrenic polymers such as copolymers and acrylonitrile-butadiene-styrene copolymers; Polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; Polyamides such as nylon 6, nylon 66, and nylon 610; Polyacetal; Oxide; polyphenylene sulfide; polyetheretherketone; polysulfone; polyethersulfone; polyoxypentylene; polyamideimide; cycloolefin polymer; cellulose derivative; and the like;

The weight average molecular weight of the resin composition (preferably a two-component mixture) is preferably 2,000 or more, more preferably 5,000 or more, still more preferably 30,000 or more, even more preferably 50,000 or more, and 10 It is particularly preferably 600,000 or less, more preferably 400,000 or less, even more preferably 300,000 or less, even more preferably 200,000 or less, and particularly preferably 150,000 or less. By setting the weight average molecular weight of the resin composition within such a range, the moldability of the copolymer (P) is improved.

The molecular weight distribution (=weight average molecular weight/number average molecular weight) of the resin composition (preferably a two-component mixture) is, for example, 1.5 or more, preferably 1.8 or more, more preferably 2.0 or more, For example, it is 5.0 or less, preferably 4.0 or less, more preferably 3.0 or less.

The weight average molecular weight of the resin composition (preferably a two-component mixture) is preferably 1.1 times or more, more preferably 1.2 times or more, and further 1.3 times or more the weight average molecular weight of the polymer chain (A). It is preferably 10 times or less, more preferably 7 times or less, and even more preferably 5 times or less. This makes it easy to give the copolymer (P) properties of transparency and mechanical strength in a well-balanced manner.

The resin composition may contain various additives. Additives include, for example, ultraviolet absorbers; antioxidants such as hindered phenol, phosphorus, and sulfur; stabilizers such as light stabilizers, weather stabilizers, and heat stabilizers; Reinforcing material; Near-infrared absorber; Flame retardants such as tris(dibromopropyl) phosphate, triallyl phosphate, antimony oxide; antistatic agents including cationic and nonionic surfactants; coloring agents such as inorganic pigments, organic pigments and dyes; organic fillers and inorganic fillers; resin modifiers; organic fillers and inorganic fillers; . The content of each additive in the resin composition is preferably in the range of 0 to 5% by mass, more preferably 0 to 2% by mass.

The amount of olefinic double bonds in the two-component mixture of the copolymer (P) and the (meth)acrylic polymer (Q) contained in the resin composition is 0.014 mmol/g or more; It is preferably 0.30 mmol/g or more, more preferably 0.050 mmol/g or more. When the amount of olefinic double bonds in the mixture of the two components is 0.014 mmol/g or more, the thermal decomposition initiation temperature of the resin composition can be increased, that is, the heat resistance of the resin composition can be increased. . Further, the amount of olefinic double bonds in the mixture of the two components is 0.150 mmol/g or less, preferably 0.130 mmol/g or less, more preferably 0.120 mmol/g or less. When the amount of olefinic double bonds in the mixture of the two components is 0.150 mmol/g or less, it is possible to suppress the generation of gelled substances during molding of the resin composition.

The resin composition preferably has a glass transition temperature of 115°C or higher, and more preferably has a glass transition temperature of 115°C or higher and lower than 115°C. A glass transition temperature of 115° C. or higher is referred to as a “high temperature side glass transition temperature”, and a glass transition temperature of less than 115° C. is referred to as a “low temperature side glass transition temperature”. The resin composition may have a plurality of glass transition temperatures on the high temperature side, or may have a plurality of glass transition temperatures on the low temperature side. Since the resin composition has a glass transition temperature on the high temperature side, the heat resistance of the resin composition is improved, and when the resin composition is molded into a film or the like, the resin composition does not soften even at high temperatures, improving moldability. can be done. When the resin composition has a glass transition temperature on the low temperature side, the mechanical strength and impact resistance of the resin composition can be enhanced. The glass transition temperature of the resin composition on the high temperature side is 115° C. or higher, preferably 120° C. or higher. It is more preferably less than 180°C, particularly preferably 150°C or less, and most preferably 130°C or less. The glass transition temperature of the resin composition on the low temperature side is preferably −100° C. or higher, more preferably −60° C. or higher, preferably less than 50° C., more preferably less than 30° C., further preferably less than 10° C., and −20° C. Especially preferred is less than -50°C, most preferred is less than -50°C.

The thermal decomposition initiation temperature of the resin composition is preferably 310° C. or higher, more preferably 320° C. or higher, and even more preferably 330° C. or higher. Although the upper limit of the thermal decomposition initiation temperature of the resin composition is not particularly limited, it is, for example, 400° C. or lower, preferably 370° C. or lower. The thermal decomposition initiation temperature is determined by the method described in Examples.

The resin composition preferably has an internal haze of 2.0% or less, more preferably 1.0% or less, and further preferably 0.50% or less per 100 μm of thickness when it is made into an unstretched film. Preferably, 0.30% or less is particularly preferable, and 0.19% or less is most preferable. Although the lower limit of the internal haze is not particularly limited, it is, for example, 0.01% or more. Internal haze is determined by the method described in Examples.

The resin composition preferably has a chromaticity b* per 100 µm of thickness in L*a*b* color space when made into an unstretched film of 2.0 or less, preferably 0.6 or less. , is more preferably 0.4 or less, and even more preferably 0.2 or less. The lower limit of chromaticity b ^* is not particularly limited. Chromaticity b ^* is preferably as small as possible, and may be zero. When the chromaticity b ^* is 2.0 or less, the hue becomes small and the saturation becomes low.
As used herein, "chromaticity b ^* " means the b ^* value of an optical film from which surface irregularities have been eliminated by immersion in 1,2,3,4-tetrahydronaphthalene (tetralin). “Chromaticity b* per 100 μm thickness” is calculated from an equation derived by the method of least squares after measuring the chromaticity b* of optical films having different thicknesses. Specific measurement methods and calculation methods are as described in Examples. If the resin composition of the present invention is within the above range, it can be suitably used for optical films such as polarizer protective films.

The resin composition preferably has a breaking energy (impact strength) of 20 mJ or more, more preferably 30 mJ or more, and even more preferably 40 mJ or more when made into an unstretched film having a thickness of 160 μm. Thereby, when a film is formed from the resin composition (Q), it becomes easier to obtain a film having high mechanical strength. Fracture energy is determined by the method described in Examples.

4. Resin molded article The resin composition can be formed into a molded article by molding according to a known method. The shape of the molded article may be appropriately set according to the application, and examples thereof include plate-like, sheet-like, granular, powdery, lumpy, particle aggregate, spherical, ellipsoidal, lens-like, cubic, columnar, rod-like, etc. Conical, cylindrical, needle, fibrous, hollow fiber, porous, and the like can be mentioned. For molding the resin composition, injection molding, extrusion molding, vacuum molding, compression molding, blow molding, etc. can be used. It is preferably a solid, a cylindrical or spherical pellet having a major diameter of about 1 mm to 10 mm, or a mixture thereof. When the resin composition is formed into a film, it may be formed into a film through pelletization after polymerization, or conversely, it may be directly supplied to an extruder without pelletization after polymerization and formed into a film.
The resin composition is excellent in transparency, color, heat resistance, moldability, and mechanical strength. Sheets, bottles, containers, camera lenses, viewfinder lenses, CCD and CMOS lenses, retardation films, diffusion sheets, polarizing films, etc. used in liquid crystal and plasma displays. , FPD front panel, optical discs, optical materials, optical parts, LED lighting for binders that fix dyes and charge transfer agents, lighting building materials, sound insulation walls, etc.

The resin composition can also be formed into a film. Known methods such as a solution casting method (solution casting method), a melt extrusion method, a calendering method and a compression molding method can be used as the film forming method. Among these, the solution casting method and the melt extrusion method are preferable.

Apparatus for performing the solution casting method includes, for example, a drum type casting machine, a band type casting machine, a spin coater and the like.

The melt extrusion method includes a T-die method, an inflation method, and the like. When forming a film by a melt extrusion method, it may be made into a stretched film by stretching. Stretching can further improve the mechanical strength of the film. As a stretching method for obtaining a stretched film, a conventionally known stretching method can be applied. For example, uniaxial stretching such as free width uniaxial stretching and constant width uniaxial stretching; biaxial stretching such as sequential biaxial stretching and simultaneous biaxial stretching; A birefringent film in which molecular groups oriented in the stretching direction and the thickness direction are mixed is obtained by applying a shrinkage force in a direction perpendicular to the stretching direction to the film by heat-stretching the laminate. The stretching etc. which obtain are mentioned. Biaxial stretching is preferably used from the viewpoint of improving mechanical strength such as folding endurance of the film. The stretching conditions such as the stretching ratio, stretching temperature, and stretching speed are not particularly limited, and may be appropriately set according to the desired mechanical strength and retardation value.

The stretching apparatus includes, for example, a roll stretching machine, a tenter type stretching machine, and a small experimental stretching apparatus such as a tensile tester, a uniaxial stretching machine, a sequential biaxial stretching machine, a simultaneous biaxial stretching machine, and the like. equipment can be used.

When applying the stretched film to the optical film, in order to stabilize the optical properties and mechanical properties of the optical film, heat treatment (annealing) may be performed after stretching, if necessary.

5. Optical Film A film formed from a resin composition can be suitably used as an optical film because of its excellent transparency. The optical film thus obtained has excellent mechanical strength and heat resistance. The optical film may be a stretched film or an unstretched film. Examples of optical films include optical protective films (specifically, protective films for substrates of various optical discs (VD, CD, DVD, MD, LD, etc.)), and polarizing plates provided in image display devices such as liquid crystal displays. Polarizer protective film, viewing angle compensation film, light diffusion film, reflective film, antireflection film, antiglare film, brightness enhancement film, conductive film for touch panel, retardation film, light conversion film and the like.

The thickness of the optical film is preferably 5 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more, from the viewpoint of increasing the strength of the optical film. On the other hand, from the viewpoint of thinning the optical film, the thickness of the optical film is preferably 350 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less. The thickness of the optical film can be measured using, for example, a Mitutoyo Digimatic Micrometer.

From the viewpoint of enhancing transparency, the optical film preferably has a haze of 3.0% or less, more preferably 2.0% or less, and even more preferably 1.0% or less. Also, the internal haze is preferably 3.0% or less, more preferably 2.0% or less, and even more preferably 1.0% or less.

The optical film of the present invention can also be used as a polarizer protective film by laminating it on one side or both sides of a polarizer. It can also be used as a transparent conductive film by forming a transparent conductive layer on the surface.

The optical film of the present invention (eg, retardation film, polarizer protective film, transparent conductive film) can be suitably used for image display devices. Examples of image display devices include liquid crystal display devices. For example, in the case of a liquid crystal display device, the image display section can be configured to have the optical film of the present invention together with members such as a liquid crystal cell, a polarizing plate and a backlight. Examples of image display devices other than liquid crystal display devices include electroluminescence (EL) display panels, plasma display panels (PDP), field emission displays (FED), QLEDs, and micro LEDs.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited by the following examples, and can be modified appropriately within the scope that can conform to the gist of the above and later descriptions. It is of course possible to implement them, and all of them are included in the technical scope of the present invention. In the following description, "part" means "mass part" and "%" means "% by mass" unless otherwise specified.

(1) Analysis method (1-1) Weight average molecular weight (Mw) and number average molecular weight (Mn)
The weight average molecular weight and number average molecular weight were determined by polystyrene conversion using gel permeation chromatography (GPC). The apparatus and measurement conditions used for the measurement are as follows.
-Measurement system: GPC system HLC-8220 manufactured by Tosoh Corporation
- Column configuration on the measurement side Guard column: TSKguardcolumn SuperHZ-L manufactured by Tosoh Corporation
Separation column: TSKgel SuperHZM-M, manufactured by Tosoh Corporation 2 columns connected in series - reference side column configuration Reference column: TSKgel SuperH-RC, manufactured by Tosoh Corporation
- Developing solvent: chloroform (manufactured by Wako Pure Chemical Industries, special grade)
- Solvent flow rate: 0.6 mL / min - Standard sample: TSK standard polystyrene (manufactured by Tosoh Corporation, PS-oligomer kit)

(1-2) glass transition temperature (Tg)
The glass transition temperature was obtained according to JIS K 7121 (2012). Specifically, a differential scanning calorimeter (Thermo plus EVO DSC-8230, manufactured by Rigaku Co., Ltd.) was used to heat a sample from room temperature to 200° C. (heating rate: 20° C./min) in a nitrogen gas atmosphere. It was evaluated by the starting point method from the DSC curve obtained by the method. α-alumina was used as a reference. A glass transition temperature of less than 40°C was measured by using a differential scanning calorimeter (DSC-3500, manufactured by Netsch Co.) and heating the sample from -100°C to 60°C in a nitrogen gas atmosphere (heating rate: 10°C/min). It was evaluated by the starting point method from the DSC curve obtained by the method. An empty container was used as a reference.

(1-3) Amount of Olefinic Double Bonds The amount of olefinic double bonds was obtained by iodometric titration. After weighing 0.1 to 3 g of the sample and dissolving it in 20 g of toluene, add 12.5 mL of Wiiss' test solution (0.1 mol/L iodine chloride/acetic acid solution, manufactured by Wako Pure Chemical Industries, Ltd.) and stir for 1 hour. left undisturbed. 10 mL of 10 w/v % potassium iodide solution (manufactured by Kishida Chemical Co., Ltd.) and 50 mL of deionized water were added thereto and stirred well, and then several drops of starch solution (manufactured by Kishida Chemical Co., Ltd.) were added and further stirred. Titration was performed with a 0.1 mol/L sodium thiosulfate solution (manufactured by Wako Pure Chemical Industries, Ltd.) while stirring the liquid well, and the end point was when the iodine coloration disappeared. A blank test was also conducted without using any sample. The amount of olefinic double bonds in the sample was determined by the following formula.
Olefinic double bond amount (mmol/g) = (AB) x F x x/(2 x C x d)
A: Amount of sodium thiosulfate in blank test (g)
B: Sodium thiosulfate amount (g) in this test
F: sodium thiosulfate factor x: sodium thiosulfate concentration (0.1 mol / L)
C: sample amount (g)
d: sodium thiosulfate density (1.01 g/mL)

(1-4) Heat retention evaluation (gelation evaluation)
A heat retention evaluation of the resin composition was performed by a filter filtration test. The heat retention evaluation was conducted by heating and retaining the resin compositions obtained in the following production examples at 290° C. for 10 minutes using a differential differential thermal balance (ThermoPlus2TG-8120 Dynamic TG, manufactured by Rigaku Corporation). was used. The resin composition after heat retention was dissolved in chloroform to prepare a 0.1% by mass chloroform solution, which was placed in a plastic syringe with a filter (GL Sciences, Chromatodisc 13N, pore size 0.45 μm) attached to the tip. was filtered using If 2 mL of the chloroform solution of the resin composition could be completely filtered, it was evaluated as ◯, and if the filter was clogged on the way and 2 mL of the solution could not be filtered, it was evaluated as x.

(1-5) Thermal decomposition initiation temperature The thermal decomposition initiation temperature was analyzed by the following method (dynamic TG method).
Measuring device: differential thermal balance (ThermoPlus2TG-8120 Dynamic TG, manufactured by Rigaku Co., Ltd.)
Measurement conditions: sample amount 10 mg
Heating rate: 10°C/min
Atmosphere: Nitrogen flow 200 mL/min
Method: Stepped isothermal control method (controlled to a mass reduction rate value of 0.005% / s or less within the range from 150 ° C. to 500 ° C.)
The temperature at which stepped isothermal control was first performed to maintain the above mass reduction rate (the lowest temperature at which stepped isothermal control was performed) was taken as the pyrolysis initiation temperature.

(1-6) Monomer Conversion Rate and Resin Composition Composition It was obtained by measuring the amount of residual monomers. The measuring apparatus and measuring conditions for gas chromatography are as follows.
Column: Shinwa Kako Co., Ltd., ULBON HR-1, length 50 m, inner diameter 0.25 mm, film thickness 0.25 μm
Column heating conditions: After holding at 60°C for 5 minutes, the temperature was raised to 235°C over 35 minutes at a temperature increase rate of 5°C/minute, and then to 315°C at a temperature increase rate of 25°C/minute over 3.2 minutes. The temperature was raised by , and was maintained as it was for 10 minutes.
Vaporization chamber temperature: 250°C
Detector (FID) temperature: 320°C
Carrier gas: helium (250 kPa)
Total flow: 19.2 mL/min Column flow: 2.69 mL/min Split ratio: 5.0

(1-7) Fracture energy (impact strength)
The resin composition was hot-press molded at 250° C. to produce a film (unstretched film) having a thickness of 160 μm. A test of dropping a ball having a mass of 0.0054 kg from a certain height onto this film was performed 10 times, and the average value of the height when the film was destroyed (destruction height) was obtained. Specifically, the height was set in several stages, and when the ball was dropped in order from the lowest height, the height at which the film cracked was found, and after repeating this 10 times, the film cracked. The height was determined 10 times, and the value obtained by averaging these values was determined as the breaking height. Whether or not the film was destroyed was determined by visually confirming whether or not the film was deformed after the ball was dropped onto the film. If deformation was observed, the film was considered destroyed. The breaking energy (E) was obtained according to the following formula: Breaking energy E (mJ)=mass of sphere (kg)×average breaking height (mm)×9.8 (m/s ² ).

(1-8) Internal haze (internal haze per 100 μm thickness of unstretched film)
The resin composition was hot-press molded at 250° C. to prepare a film (unstretched film) having a thickness of about 160 μm. A quartz cell was filled with 1,2,3,4-tetrahydronaphthalene (tetralin), the prepared film was immersed therein, and the haze was measured using a haze meter (NDH-5000, manufactured by Nippon Denshoku Industries Co., Ltd.). , the internal haze per 100 μm thickness was calculated according to the following formula: internal haze (%) per 100 μm thickness=obtained measured value (%)×(100 μm/film thickness (μm)). The measurement was performed using three films, and the internal haze per 100 μm thickness was calculated from the average value.

(1-9) b ^* value (internal b ^* value per 100 μm thickness of unstretched film)
The b ^* value was measured in accordance with JIS Z 8729 using a spectral color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd.: Colormeter ZE6000). Specifically, the resin composition was heat-press-molded at 250° C. to prepare a film (unstretched film) having a thickness of about 160 μm, which was cut into a size of 45 mm×35 mm. An unstretched film cut out to 45 mm × 35 mm was immersed in a quartz cell with an optical path length of 10 mm containing 1,2,3,4-tetrahydronaphthalene (tetralin) and measured, and then two or three unstretched films. and measured in the same manner. Next, plot the measured b ^* value on the y-axis and the thickness of the unstretched film on the x-axis, calculate the slope of the straight line of the plot by the least squares method, and obtain the b ^* value at a film thickness of 100 μm was calculated.

<Example 1>
A first SEBS triblock copolymer (manufactured by Asahi Kasei Corporation, Tuftec (registered trademark) P1083 (hereinafter sometimes referred to as SEBS-1) was added to a reactor equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen inlet pipe. , olefinic double bond content 2.01 mmol / g, styrene unit content 18.3 mass%, refractive index 1.500, weight average molecular weight 94,000, number average molecular weight 64,000) 3 parts, 2 SEBS triblock copolymer (manufactured by Asahi Kasei Corporation, Tuftec (registered trademark) H1052 (hereinafter sometimes referred to as SEBS-2), olefinic double bond content 0.27 mmol / g, styrene unit content 15.7 mass%, refractive index 1.500, weight average molecular weight 94,000, number average molecular weight 69,000) 7 parts, methyl methacrylate (MMA) 73.8 parts, 2-(hydroxymethyl) methyl acrylate 10.8 parts of (MHMA), 0.025 parts of n-dodecyl mercaptan (nDM), and 100 parts of toluene as a polymerization solvent were charged, and the temperature was raised to 105° C. while passing nitrogen. After that, 0.06 part of t-butylperoxyisopropyl carbonate (manufactured by Kayaku Akzo Co., Ltd., Kayacarbon (registered trademark) Bic75) was added as an initiator. After confirming the start of the polymerization reaction by increasing the temperature of the polymerization solution, addition of styrene (St) and t-butylperoxyisopropyl carbonate was started. 5.4 parts of styrene (St) was added at a constant rate over 3 hours, and 0.185 parts of t-butylperoxyisopropyl carbonate diluted in 1 part of toluene was added dropwise at a constant rate over 4 hours. While solution polymerization was carried out at 105 to 110° C., and after the addition of t-butylperoxyisopropyl carbonate was completed, aging was further carried out for 2 hours. The half-life of t-butyl peroxyisopropyl carbonate is about 5.5 hours at 105°C, about 3.4 hours at 110°C, and about 2.1 hours at 115°C. 0.075 part of stearyl phosphate was added as a cyclization catalyst, and a cyclization condensation reaction for forming a lactone ring structure was carried out under reflux at 90 to 110° C. for 2 hours. A sulfur-based antioxidant (ADEKA Co., Ltd., ADEKA STAB (registered trademark) AO-412S) and a hindered phenol-based antioxidant (ADEKA Co., Ltd., ADEKA STAB (registered trademark) AO-60) were added to the resulting reaction solution. 0.05 part was added. As a result, a (meth)acrylic copolymer polymerized from MMA, MHMA and St and having a lactone ring structure in the main chain, and a diene/olefin-derived copolymer chain in which the copolymer chain is a SEBS triblock copolymer chain A resin composition comprising the graft copolymer attached to the units was obtained. The conversion rate of MMA calculated from the amount of residual monomers in the polymerization solution at the end of the reaction was 94%, the conversion rate of MHMA was 94%, and the conversion rate of St was 99%. The composition ratio (by mass) of the (meth)acrylic copolymer chain bonded to the SEBS triblock copolymer chain calculated from the conversion rate and the (meth)acrylic copolymer is MMA:MHMA:St = 82.6:11.9:5.5, and the content of the ring structural unit was 22.0% by mass.
Next, the resulting polymerization solution was passed through a shell and tube heat exchanger heated to 240° C. to complete the cyclization condensation reaction. After that, the cyclization-condensed polymer was subjected to a barrel temperature of 250° C., one rear vent, four fore vents (referred to as first, second, third, and fourth vents from the upstream side) and a fourth vent. A vent-type screw twin-screw extruder (L / D = 52) equipped with a side feeder between the 3 vent and the 4th vent, and a leaf disk-shaped polymer filter (filtration accuracy of 5 μm) at the tip, 33 It was introduced at a processing rate of .7 parts/hour (converted to the amount of resin). At that time, ion-exchanged water was introduced from the back of the second vent at an injection rate of 0.50 parts/hour, and 0.66 parts of an ultraviolet absorber (ADEKA Co., Ltd., Adekastab (registered trademark) LA-F70) was added to 1 part of toluene. A solution dissolved in .23 parts was introduced from behind the 3rd vent at a charging speed of 0.64 parts/hour, and ion-exchanged water was charged from behind the 4th vent at a charging speed of 0.50 parts/hour. and devolatized.
After the completion of devolatilization, the resin composition in a hot melt state remaining in the extruder is discharged from the tip of the extruder while being filtered through a polymer filter. , Product name: Micropore filter 1EU), the strand is cooled with a water tank filled with cooling water maintained at a temperature within the range of 30 ± 10 ° C., and introduced into a cutting machine (pelletizer) to obtain a lactone ring. A lactone ring-based polymer having a structure in the main chain, a graft copolymer in which the copolymer chain is bonded to a diene/olefin-derived unit of the SEBS triblock copolymer chain, and an ultraviolet absorber (UV absorber) A pellet made of the resin composition (P-1) containing
The resulting resin composition (P-1) had a weight average molecular weight of 138,000, a number average molecular weight of 52,000, a glass transition temperature on the high temperature side of 121°C, and a glass transition temperature on the low temperature side of -54°C. , the thermal decomposition initiation temperature was 338° C., and the refractive index was 1.500. The amount of double bonds in the resin composition was 0.069 mmol/g. Moreover, when the heat retention evaluation of the obtained resin composition was performed, it was able to be suitably filtered. The obtained resin composition was formed into a film and found to have an internal haze of 0.14%, a b ^* value of 0.6, and a breaking energy of 40 mJ or more.

<Example 2>
The polymerization solution was the same as in Example 1. Under the charging conditions of the twin-screw extruder, the polymerization solution was introduced at a processing rate of 33.7 parts/hour (converted to the amount of resin), and the second, third, and fourth vents The extruder treatment was carried out in the same manner as in Example 1, except that ion-exchanged water was added at a rate of 0.50 parts/hour from the back of each, and devolatilization was performed, and the lactone ring structure was formed in the main chain. Pellets made of a resin composition (P-2) containing a lactone ring-based polymer having in Obtained.
The resulting resin composition (P-2) had a weight average molecular weight of 137,000, a number average molecular weight of 51,000, a glass transition temperature on the high temperature side of 122°C, and a glass transition temperature on the low temperature side of -54°C. , the thermal decomposition initiation temperature was 336° C., and the refractive index was 1.500. The amount of double bonds in the resin composition was 0.067 mmol/g. Moreover, when the gelation evaluation of the obtained resin composition was performed, it was able to be suitably filtered. The obtained resin composition was formed into a film and found to have an internal haze of 0.18%, a b ^* value of 0.1, and a breaking energy of 40 mJ or more.

<Example 3>
A reactor equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen inlet pipe was charged with 10 parts of SEBS-2 (manufactured by Asahi Kasei Corporation, Tuftec (registered trademark) H1052), 74.7 parts of methyl methacrylate (MMA), 13.5 parts of methyl 2-(hydroxymethyl)acrylate (MHMA), 0.025 parts of n-dodecyl mercaptan (nDM), and 100 parts of toluene as a polymerization solvent were charged, and the temperature was raised to 105°C while passing nitrogen through. let me After that, 0.075 part of t-butylperoxyisopropyl carbonate (Kayacarvone (registered trademark) Bic75 manufactured by Kayaku Akzo Co., Ltd.) was added as an initiator. After confirming the start of the polymerization reaction by increasing the temperature of the polymerization solution, addition of styrene (St) and t-butylperoxyisopropyl carbonate was started. 1.8 parts of styrene (St) and 0.170 parts of t-butylperoxyisopropyl carbonate diluted in 1 part of toluene were added dropwise at a constant rate over 3 hours to form a solution at 105 to 110°C. Polymerization was carried out, and after completion of addition of t-butylperoxyisopropyl carbonate, aging was carried out for 2 hours. 0.075 part of stearyl phosphate was added as a cyclization catalyst, and a cyclization condensation reaction for forming a lactone ring structure was carried out under reflux at 90 to 110° C. for 2 hours. A sulfur-based antioxidant (ADEKA Co., Ltd., ADEKA STAB (registered trademark) AO-412S) and a hindered phenol-based antioxidant (ADEKA Co., Ltd., ADEKA STAB (registered trademark) AO-60)) were added to the resulting reaction solution. 0.05 part of each was added. As a result, a (meth)acrylic copolymer polymerized from MMA, MHMA and St and having a lactone ring structure in the main chain, and a diene/olefin-derived copolymer chain in which the copolymer chain is a SEBS triblock copolymer chain A resin composition comprising the graft copolymer attached to the units was obtained. The conversion rate of MMA calculated from the amount of residual monomers in the polymerization solution at the end of the reaction was 95%, the conversion rate of MHMA was 97%, and the conversion rate of St was 99%. The composition ratio (by mass) of the (meth)acrylic copolymer chain bonded to the SEBS triblock copolymer chain calculated from the conversion rate and the (meth)acrylic copolymer is MMA:MHMA:St = 82.7:15.3:2.1, and the content of ring structural units was 30.3% by mass.
The obtained polymerization solution was treated with an extruder in the same manner as in Example 2 to convert the lactone ring-based polymer having a lactone ring structure in the main chain and the copolymer chain into an SEBS triblock copolymer chain. and the graft copolymer bonded to the diene/olefin-derived units of the resin composition (P-3).
The resulting resin composition (P-3) had a weight average molecular weight of 150,000, a number average molecular weight of 58,000, a glass transition temperature on the high temperature side of 126°C, and a glass transition temperature on the low temperature side of -54°C. , the thermal decomposition initiation temperature was 340° C., and the refractive index was 1.501. The amount of double bonds in the resin composition (P-3) was 0.015 mmol/g. Moreover, when the gelation evaluation of the obtained resin composition was performed, it was able to be suitably filtered. The obtained resin composition was formed into a film and found to have an internal haze of 0.43%, a b ^* value of 0.2, and a breaking energy of 40 mJ or more.

<Example 4>
3.5 parts of SEBS-1 (Asahi Kasei Co., Ltd., Tuftec (registered trademark) P1083), SEBS-2 (Asahi Kasei Co., Ltd., Tuftec ( 5.2 parts of a registered trademark) H1052), a third SEBS triblock copolymer (manufactured by Asahi Kasei Corporation, Tuftec (registered trademark) H1041 (hereinafter sometimes referred to as SEBS-3), an olefinic double bond content of 0 .45 mmol / g, styrene unit content 27.4% by mass, refractive index 1.512, weight average molecular weight 84,000, number average molecular weight 63,000) 6.3 parts, methyl methacrylate (MMA) 66.3 parts, 12.75 parts of 2-(hydroxymethyl)methyl acrylate (MHMA), 0.010 parts of n-dodecyl mercaptan (nDM), and 100 parts of toluene as a polymerization solvent were charged, and nitrogen was passed through them. The temperature was raised to 105°C. After that, 0.115 part of t-butylperoxyisopropyl carbonate (Kayacarvone (registered trademark) Bic75 manufactured by Kayaku Akzo Co., Ltd.) was added as an initiator. After confirming the start of the polymerization reaction by increasing the temperature of the polymerization solution, addition of styrene (St) and t-butylperoxyisopropyl carbonate was started. 5.95 parts of styrene (St) and 0.252 parts of t-butylperoxyisopropyl carbonate diluted in 1 part of toluene were added dropwise at a constant rate over 3 hours to form a solution at 105 to 110°C. Polymerization was carried out, and after completion of addition of t-butylperoxyisopropyl carbonate, aging was carried out for 2 hours. 0.075 part of stearyl phosphate was added as a cyclization catalyst, and a cyclization condensation reaction for forming a lactone ring structure was carried out under reflux at 90 to 110° C. for 2 hours. A sulfur-based antioxidant (ADEKA Co., Ltd., ADEKA STAB (registered trademark) AO-412S) and a hindered phenol-based antioxidant (ADEKA Co., Ltd., ADEKA STAB (registered trademark) AO-60) were added to the resulting reaction solution. 0.05 part was added. As a result, a (meth)acrylic copolymer polymerized from MMA, MHMA and St and having a lactone ring structure in the main chain, and a diene/olefin-derived copolymer chain in which the copolymer chain is a SEBS triblock copolymer chain A resin composition comprising the graft copolymer attached to the units was obtained. The conversion rate of MMA calculated from the amount of residual monomers in the polymerization solution at the end of the reaction was 95%, the conversion rate of MHMA was 96%, and the conversion rate of St was 99%. The composition ratio (by mass) of the (meth)acrylic copolymer chain bonded to the SEBS triblock copolymer chain calculated from the conversion rate and the (meth)acrylic copolymer is MMA:MHMA:St =77.6:15.1:7.3, and the content of the ring structural unit was 30.0% by mass.
The obtained polymerization solution was treated with an extruder in the same manner as in Example 2 to convert the lactone ring-based polymer having a lactone ring structure in the main chain and the copolymer chain into an SEBS triblock copolymer chain. and the graft copolymer bonded to the diene/olefin-derived units of the resin composition (P-4).
The resulting resin composition (P-4) had a weight average molecular weight of 137,000, a number average molecular weight of 51,000, a glass transition temperature on the high temperature side of 124°C, and a glass transition temperature on the low temperature side of -54°C. , the thermal decomposition initiation temperature was 344° C., and the refractive index was 1.503. The amount of double bonds in the resin composition (P-4) was 0.112 mmol/g. Moreover, when the gelation evaluation of the obtained resin composition was performed, it was able to be suitably filtered. The obtained resin composition was formed into a film and found to have an internal haze of 0.16%, a b ^* value of 0.1, and a breaking energy of 40 mJ or more.

<Reference example 1>
10 parts of SEBS-1 (manufactured by Asahi Kasei Corporation, Tuftec (registered trademark) P1083, olefinic double bond content 2.01 mmol / g, styrene unit content 20% by mass, refractive index 1.500), methyl methacrylate 74.7 parts of (MMA), 13.5 parts of 2-(hydroxymethyl)methyl acrylate (MHMA), 0.025 parts of n-dodecyl mercaptan (nDM), and 100 parts of toluene as a polymerization solvent were charged. The temperature was raised to 105°C while nitrogen was passed through. After that, 0.096 part of t-butylperoxyisopropyl carbonate (manufactured by Kayaku Akzo Co., Ltd., Kayacarbon (registered trademark) Bic75) was added as an initiator. After confirming the start of the polymerization reaction by increasing the temperature of the polymerization solution, addition of styrene (St) and t-butylperoxyisopropyl carbonate was started. 1.8 parts of styrene (St) is added at a constant rate over 3 hours, and 0.213 parts of t-butylperoxyisopropyl carbonate diluted in 1 part of toluene is added dropwise at a constant rate over 4 hours. Except for the steps, the aging and cyclization condensation reactions were carried out in the same manner as in Example 2, and then the treatment was performed using an extruder, whereby a lactone ring-based polymer having a lactone ring structure in the main chain and the copolymer chain were formed into SEBS tri-polymers. Pellets were obtained from the resin composition (P-5) containing the graft copolymer bonded to the diene/olefin-derived units of the block copolymer chain.
The resulting resin composition (P-5) had a weight average molecular weight of 151,000, a number average molecular weight of 57,000, a glass transition temperature on the high temperature side of 127°C, and a glass transition temperature on the low temperature side of -54°C. , the thermal decomposition initiation temperature was 340° C., and the refractive index was 1.500. The amount of double bonds in the resin composition was 0.201 mmol/g. The obtained resin composition was formed into a film and found to have an internal haze of 0.15%, a b ^* value of 0.1, and a breaking energy of 40 mJ or more. Further, when the obtained resin composition was evaluated for gelation, clogging occurred and was evaluated as x. It is presumed that a radical cross-linking reaction occurred due to heating because many double bonds remained.

<Comparative Example 1>
SEBS triblock copolymer (manufactured by Kraton Co., Ltd., G1652 (hereinafter sometimes referred to as SEBS-4), olefinic double bond content 0.10 mmol / g, styrene unit content 30% by mass, weight average molecular weight 80,000, number average molecular weight 68,000) 10 parts, methyl methacrylate (MMA) 79.2 parts, styrene (St) 10.8 parts, n-dodecyl mercaptan (nDM) 0.1 0.5 parts of t-butylperoxyisopropyl carbonate (manufactured by Kayaku Akzo Co., Ltd., Kayacarbon (registered trademark) Bic 75) as an initiator and 100 parts of toluene as a polymerization solvent were charged, and nitrogen was passed through and sealed. The reaction was carried out for 6 hours in an oil bath at 115 degrees. The conversion rate of MMA calculated from the amount of residual monomers in the polymerization solution at the end of the reaction was 76%, and the conversion rate of St was 98%. The composition ratio (by mass) of the (meth)acrylic copolymer chains bonded to the SEBS triblock copolymer chain calculated from the conversion rate and the (meth)acrylic copolymer was MMA:St=85. The resulting polymer solution was diluted with chloroform and added dropwise to methanol to precipitate the polymer produced. Thereafter, suction filtration is performed, followed by drying in a vacuum dryer at 100°C for 1 hour, followed by drying in a vacuum dryer at 240°C for 1 hour to remove unreacted monomers. A resin composition (P-6) containing a copolymer and a graft copolymer in which the copolymer chain was bonded to the diene/olefin-derived units of the SEBS triblock copolymer chain was obtained.
The resulting resin composition (P-6) had a weight average molecular weight of 135,000, a number average molecular weight of 61,000, a glass transition temperature on the high temperature side of 114°C, and a glass transition temperature on the low temperature side of -54°C. , the refractive index was 1.505. The amount of double bonds in the resin composition was 0.010 mmol/g. Moreover, when the gelation evaluation of the obtained resin composition was performed, it was able to be suitably filtered. The obtained resin composition was formed into a film and found to have an internal haze of 0.20%, a b ^* value of 0.2, and a breaking energy of 40 mJ or more. The thermal decomposition starting temperature of the resin composition (P-6) was 309° C., suggesting that it is easily thermally decomposed because it does not have a ring structure in its main chain and is unsuitable for melt molding.

<Comparative Example 2>
SEBS-1 (manufactured by Asahi Kasei Corporation, Tuftec (registered trademark) P1083, olefinic double bond content 2.42 mmol / g, styrene unit content 20% by mass, refractive index 1.500) was evaluated for gelation in the same manner as in the example. As a result, clogging occurred and was evaluated as ×. Table 1 shows the physical properties of SEBS-1.

Claims (10)

A polymer chain (A) having a polymer block (a1) having a diene and/or olefin-derived unit and a polymer block (a2) having an aromatic vinyl monomer-derived unit, and a (meth)acrylic monomer an optical film comprising a copolymer (P) having a polymer chain (B) having units derived from a polymer, and a (meth)acrylic polymer (Q) having the same structural unit as the polymer chain (B) A resin composition for
The copolymer (P) is a graft copolymer in which the polymer chain (B) is grafted to the polymer block (a1) of the polymer chain (A),
The polymer chain (B) has at least one ring structure selected from a lactone ring structure, a succinimide structure, and a glutarimide structure in the main chain,
The amount of olefinic double bonds in the two-component mixture of the copolymer (P) and the (meth)acrylic polymer (Q) is 0.014 mmol/g or more and 0.150 mmol/g or less. The resin composition to be. 2. The resin composition according to claim 1, which has a breaking energy of 20 mJ or more when made into an unstretched film having a thickness of 160 μm. 3. The resin composition according to claim 1, which has a glass transition temperature of 115[deg.] C. or higher. The resin composition according to any one of claims 1 to 3, which has a thermal decomposition initiation temperature of 310°C or higher. 5. The resin composition according to any one of claims 1 to 4, which has an internal haze of 2.0% or less per 100 µm of thickness when made into an unstretched film. 6. The resin composition according to any one of claims 1 to 5, which has a chromaticity b* of 2.0 or less per 100 µm of thickness when made into an unstretched film. The resin composition according to any one of claims 1 to 6, comprising an antioxidant. In the presence of a copolymer having a polymer block (a1) having a diene and/or olefin-derived unit and a polymer block (a2) having an aromatic vinyl monomer-derived unit, a (meth)acrylic monomer Having a step of polymerizing a monomer component containing a body,
The copolymer has an olefinic double bond content of 0.2 mmol/g or more and 1.0 mmol/g or less,
generating a polymer chain (B) having units derived from a (meth)acrylic monomer in the polymer block (a1) of the copolymer;
The polymer chain (B) has at least one ring structure selected from a lactone ring structure, a succinimide structure, and a glutarimide structure in the main chain,
A method for producing a resin composition for an optical film, wherein the monomer component has a polymerization conversion rate of 85% or more. 9. The production method according to claim 8, wherein the monomer component is polymerized in the presence of the copolymer and a radical polymerization initiator. An optical film comprising the resin composition according to any one of claims 1 to 7.