JP2006131803A - Impact modifier and impact resin composition - Google Patents

Abstract

[PROBLEMS] To provide an impact modifier that can suppress the temperature dependence of haze, particularly the transparency of methacrylic resins, and to impart impact resistance to a resin composition, and methacrylic resins using the same. To provide an impact-resistant resin composition.
An impact modifier comprises an innermost layer polymer (A) containing an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms as a monomer component, and an intermediate layer having an alkyl group. The intermediate layer polymer (B) containing an alkyl acrylate having 1 to 8 carbon atoms as a monomer component, and the outer layer containing an alkyl methacrylate having 1 to 4 carbon atoms in the alkyl group as a monomer component It includes a multilayer structure graft copolymer comprising an outer layer polymer (C) containing a monomer component and having a glass transition point (Tg) of 20 to 80 ° C.
[Selection figure] None

Description

  The present invention relates to an impact modifier having reduced impact resistance and transparency, in particular, haze temperature dependency, and a methacrylic impact resin composition using the impact modifier.

  Methacrylic resins are excellent in transparency, weather resistance, and molding processability, and are widely used in automobile parts, lighting products, various panels, and the like. However, in general, methacrylic resins are not sufficiently impact resistant, so their use is narrowed.

  Therefore, in order to improve the impact resistance of the methacrylic resin, a hard resin such as a methacrylic resin can be obtained by adding a multilayered graft copolymer having a basic structure of a specific hard-soft-hard three-layer structure. It has been proposed to improve the impact resistance (see, for example, Patent Document 1). However, this method is not satisfactory although some improvement in impact resistance is seen. It is possible to achieve higher impact resistance by using a large amount of impact modifier such as the above-mentioned multilayer structure graft copolymer, but such methacrylic resin is less transparent. In addition, since the temperature dependency of haze increases, the practicality is low.

  In addition, it has been proposed to maintain impact resistance and reduce the temperature dependence of haze by using a multilayer acrylic polymer having a specific structure (see, for example, Patent Document 2). However, in this method, although improvement is seen in reducing the temperature dependence of haze, further improvement in impact resistance is required.

If a large amount of impact modifier such as the above-mentioned multi-layer acrylic polymer is used, it is possible to achieve higher impact resistance and a reduction in the temperature dependence of haze. Since the hardness of the resin is reduced, its practicality is low. In addition, since the production cost increases as the impact modifier is used in a large amount, the addition amount of the impact modifier as described above is preferably as small as possible, and the impact resistance can be improved efficiently with a small amount. An impact modifier and a resin composition using the same are desired.
Japanese Patent Publication No.55-27576 Japanese Patent Publication No. 5-88903 POLYMER HANDBOOK THIRD EDITION

  An object of the present invention is to provide an excellent impact resistance modifier and an impact resistant resin composition excellent in impact resistance using the same by suppressing the excellent transparency of methacrylic resin, particularly the temperature dependence of haze. It is to provide.

  As a result of intensive investigations in view of the present situation, the present inventors have an innermost layer polymer, an intermediate layer polymer, and an outer layer polymer having an appropriate composition, and are provided with an innermost layer, an intermediate layer, and an outer layer. A multilayer structure polymer in which the mass of the polymer forming the layer has a specific relationship, the particle size to the intermediate layer is in a specific range, and the outer layer polymer has a specific glass transition point (Tg) is impact resistant. By blending with a methacrylic resin as a property modifier, the transparency of the methacrylic resin, especially the temperature dependence of haze, can be suppressed, high hardness can be maintained, and impact resistance can be significantly improved. As a result, the inventors have found that the above problems can be solved, and have completed the present invention based on such knowledge.

That is, the present invention is an impact modifier comprising a multilayered graft copolymer in which an innermost layer, an intermediate layer, and an outer layer are sequentially laminated,
The innermost layer of the multilayer structure graft copolymer is composed of 40 to 100% by mass of alkyl methacrylate having 1 to 4 carbon atoms in the alkyl group, 0 to 60% by mass of alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, and others. Is obtained by polymerizing a monomer component containing 100 parts by mass of a monomer mixture consisting of 0 to 20% by mass of a copolymerizable monomer and 0.1 to 10 parts by mass of a polyfunctional monomer. It consists of an inner layer polymer (A),
In the presence of the innermost layer polymer (A), the intermediate layer is an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms of 70 to 90% by mass, an aromatic vinyl compound of 10 to 30% by mass, and other copolymers. It is obtained by polymerizing a monomer component containing 100 parts by mass of a monomer mixture composed of 0 to 20% by mass of a possible monomer and 0.1 parts by mass or more and less than 1 part by mass of a polyfunctional monomer. It consists of an intermediate layer polymer (B),
In the presence of the polymer formed by the outer layer up to the intermediate layer polymer (B), the alkyl methacrylate having 50 to 100% by mass of alkyl methacrylate having 1 to 4 carbon atoms and the alkyl acrylate having 1 to 8 carbon atoms of alkyl group. An outer layer weight obtained by polymerizing a monomer component containing 0 to 50% by mass and 0 to 20% by mass of other copolymerizable monomers and having a glass transition point (Tg) of 20 to 80 ° C. Consisting of coalescence (C),
The mass average particle diameter of the polymer formed up to the intermediate layer is 200 to 300 nm,
The mass ratio (A) / (B) of the innermost layer polymer (A) and the intermediate layer polymer (B) is 10/90 to 40/60,
The impact modifier is characterized in that the outer layer polymer (C) is 30 to 100 parts by mass when the total of the innermost layer polymer (A) and the intermediate layer polymer (B) is 100 parts by mass. About. The impact modifier of the present invention can maintain excellent transparency and high hardness of a methacrylic resin, and can further give remarkable impact resistance.

  The present invention also relates to an impact-resistant resin composition comprising a methacrylic resin having methyl methacrylate as a main structural unit and the impact resistance modifier according to claim 1. The impact resistant resin composition of the present invention is further excellent in impact resistance without impairing the excellent transparency and high hardness of the methacrylic resin.

  ADVANTAGE OF THE INVENTION According to this invention, the outstanding transparency which methacrylic-type resin has, especially the impact resistance modifier which suppressed the temperature dependence of haze and was excellent in impact resistance, and a resin composition using the same are provided. be able to.

  The impact modifier of the present invention is an impact modifier comprising a multilayer structure graft copolymer in which an innermost layer, an intermediate layer and an outer layer are sequentially laminated, and the innermost layer of the multilayer structure graft copolymer. Of alkyl methacrylate having 1 to 4 carbon atoms of alkyl group, 0 to 60 mass% of alkyl acrylate having 1 to 8 carbon atoms of alkyl group, and other copolymerizable monomers 0 An innermost layer polymer (A) obtained by polymerizing a monomer component containing 100 parts by mass of a monomer mixture consisting of ~ 20% by mass and 0.1-10 parts by mass of a polyfunctional monomer, In the presence of the innermost layer polymer (A), the intermediate layer is an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms of 70 to 90% by mass, an aromatic vinyl compound of 10 to 30% by mass, and other copolymers. Consists of 0-20% by weight of possible monomers It consists of an intermediate layer polymer (B) obtained by polymerizing a monomer component containing 100 parts by mass of a monomer mixture and 0.1 parts by mass or more and less than 1 part by mass of a polyfunctional monomer, In the presence of the polymer formed up to the intermediate layer polymer (B), 50 to 100% by mass of alkyl methacrylate having 1 to 4 carbon atoms in the alkyl group and 0 to 50 alkyl acrylate having 1 to 8 carbon atoms in the alkyl group. An outer layer polymer (C) obtained by polymerizing a monomer component containing 0 to 20% by mass and other copolymerizable monomers by mass and having a glass transition point (Tg) of 20 to 80 ° C. The mass average particle diameter of the polymer formed up to the intermediate layer is 200 to 300 nm, and the mass ratio (A) / (B) between the innermost layer polymer (A) and the intermediate layer polymer (B) is 10 / 90-40 / 60, innermost layer polymer (A) and intermediate layer polymerization If the outer layer polymer when the total of (B) was 100 parts by mass (C) 30 to 100 parts by weight, and is not particularly limited.

  The impact modifier of the present invention includes a multilayer structure graft copolymer having at least three layers in which an innermost layer, an intermediate layer, and an outer layer are sequentially laminated, and each layer in the multilayer structure graft copolymer. Are composed of the following polymers.

  The innermost layer polymer (A) constituting the innermost layer in the multilayer structure graft copolymer is an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms of 40 to 100% by mass (preferably 40 to 95% by mass, more preferably Is 50 to 70% by mass), alkyl acrylate having 1 to 8 carbon atoms in the alkyl group is 0 to 60% by mass (preferably 4 to 59% by mass, more preferably 29 to 49% by mass), and other copolymers. 100 parts by mass of a monomer mixture composed of 0 to 20% by mass (preferably 1 to 10% by mass) of possible monomers and 0.1 to 10 parts by mass of a polyfunctional monomer (preferably 0.1 to 5%) Mass%), and a copolymer obtained by polymerizing a monomer component, particularly preferably a copolymer obtained by emulsion polymerization. By making the composition of the monomer component within the above-mentioned ranges, excellent impact resistance and transparency can be imparted to the resin composition using the impact modifier. When the amount of alkyl methacrylate having 1 to 4 carbon atoms of the alkyl group in the monomer mixture is 40% by mass or more, a highly transparent resin composition can be obtained.

  Examples of the alkyl methacrylate having 1 to 4 carbon atoms in the alkyl group include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and n-butyl methacrylate. These may be used alone or in combination of two or more. it can. Of these, methyl methacrylate is preferably used.

  Examples of the alkyl acrylate having 1 to 8 carbon atoms in the alkyl group include methyl acrylate, ethyl acrylate, i-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and the like. A combination of the above can be used. Of these, n-butyl acrylate is preferably used.

  The other copolymerizable monomer is not particularly limited as long as it can be copolymerized with the above monomer, and examples thereof include phenyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, methacrylic acid, acrylic acid, and hydroxyethyl methacrylate. In addition to acrylamide, glycidyl methacrylate and the like, aromatic vinyl compounds such as styrene, α-methylstyrene, vinyltoluene and the like can be mentioned, and these can be used alone or in combination of two or more. Of these, styrene is preferably used. Monomers having two or more copolymerizable functional groups are classified as polyfunctional monomers shown below, and are not classified as other copolymerizable monomers.

  Such polyfunctional monomers include ethylene glycol diacrylate, 1,3-butanediol diacrylate, allyl acrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, allyl methacrylate, triallyl cyanurate, maleic acid. Examples include diallyl, divinylbenzene, diallyl phthalate, diallyl fumarate, triallyl trimelliate, and the like. These can be used alone or in combination of two or more. Of these, 1,3-butanediol dimethacrylate and allyl methacrylate are preferably used.

  The intermediate layer polymer (B) constituting the intermediate layer in the multilayer structure graft copolymer is an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms in the presence of the innermost layer polymer (A). 90% by mass (preferably 75-85% by mass), 10-30% by mass (preferably 15-25% by mass) of the aromatic vinyl compound, and 0-20% by mass of other copolymerizable monomers (preferably Includes 100 parts by mass of a monomer mixture composed of 0 to 10% by mass) and 0.1 part by mass or more and less than 1 part by mass (preferably 0.5 to 0.9 parts by mass) of a polyfunctional monomer. It is a rubbery polymer obtained by polymerizing monomer components, and is particularly preferably a copolymer obtained by emulsion polymerization, and preferably has a graft crossing between the innermost layer polymers (A). When the amount of alkyl acrylate having 1 to 8 carbon atoms in the monomer mixture is 70% by mass or more, a resin composition having high impact resistance can be obtained, and 90% by mass or less. When it is, the resin composition with high transparency can be obtained.

  Examples of the alkyl acrylate having 1 to 8 carbon atoms in the alkyl group include those exemplified as the monomers that can be used in the innermost layer polymer (A) described above. Among these, n- Preference is given to using butyl acrylate.

  Examples of the aromatic vinyl compound include styrene, α-methylstyrene, vinyltoluene and the like, and these can be used alone or in combination of two or more. Of these, styrene is preferably used.

  Examples of the other copolymerizable monomers include phenyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, methacrylic acid, acrylic acid, hydroxyethyl methacrylate, acrylamide, and glycidyl methacrylate. Monomers having two or more copolymerizable functional groups are classified as polyfunctional monomers shown below, and are not classified as other copolymerizable monomers.

  As this polyfunctional monomer, the thing similar to what was illustrated as a monomer which can be used for the innermost layer polymer (A) mentioned above can be mentioned. These can be used alone or in combination of two or more. Of these, allyl methacrylate is preferably used.

  Further, the intermediate layer polymer (B) preferably has a glass transition point (Tg) of 0 ° C. or lower, more preferably −10 ° C. or lower. When the intermediate layer polymer (B) having the monomer component composition has a glass transition point (Tg) in this range, it is possible to impart excellent impact resistance as a modifier to the resin composition.

Here, in the present invention, the glass transition point (Tg) of the polymer is a generally known FOX formula:
_{1 / Tg = a 1 / Tg} 1 + a 2 / Tg 2 + a 3 / Tg 3 + ...
According to the calculation, the Tg ₁ , Tg ₂ and Tg ₃ in the formula are obtained when the monomers contained in the monomer components used to form each polymer are polymerized alone. It represents the glass transition point (Tg) of each of the obtained homopolymers, and is a value obtained by quoting the values described in “POLYMER HANDBOOK THIRD EDITION” (Non-patent Document 1) (the same shall apply hereinafter). . Further, a ₁ , a ₂ and a _{3 in} the formula of FOX represent the respective mass fractions of the monomers contained in the monomer component used to form each polymer.

  The outer layer polymer (C) constituting the outer layer in the multilayer structure graft copolymer is more accurately expressed in the presence of the polymer formed up to the above-mentioned intermediate layer polymer (B). ) And an intermediate layer polymer (B) in the presence of a polymer comprising 50 to 100% by mass (preferably 60 to 85% by mass) of an alkyl methacrylate having 1 to 4 carbon atoms, 0 to 50% by mass (preferably 15 to 40% by mass) of alkyl acrylate having 1 to 8 carbon atoms, and 0 to 20% by mass (preferably 0 to 10% by mass) of other copolymerizable monomers It is a polymer obtained by polymerizing the monomer component to be contained, and is particularly preferably a copolymer obtained by emulsion polymerization, and preferably has a graft crossing between the intermediate layer polymers (B). When the amount of alkyl methacrylate having 1 to 4 carbon atoms of the alkyl group in the monomer component is 50% by mass or more, blocking can be suppressed when recovered as a powder, and handling is improved. .

  Examples of the alkyl methacrylate having 1 to 4 carbon atoms in the alkyl group include the same alkyl methacrylates having 1 to 4 carbon atoms in the alkyl group that can be used in the innermost layer polymer (A). Of these, methyl methacrylate is preferably used.

  Examples of the alkyl acrylate having 1 to 8 carbon atoms in the alkyl group include alkyl acrylates having 1 to 8 carbon atoms in the alkyl group that can be used in the innermost layer polymer (A) and the intermediate layer polymer (B). The thing similar to what was done can be mentioned, It is preferable to use n-butyl acrylate.

  As said other copolymerizable monomer, the thing similar to what was illustrated as another copolymerizable monomer which can be used for innermost layer polymer (A) mentioned above can be mentioned.

  The number average molecular weight of the homopolymer having no graft crossing with the intermediate layer polymer (B) of the outer layer polymer (C) having such a monomer component is 10,000 to 1,000,000. preferable.

  Further, the outer layer polymer (C) needs to have a glass point transfer (Tg) of 20 to 80 ° C, preferably 30 to 70 ° C. When the glass transition point (Tg) is 20 ° C. or higher, blocking can be suppressed when recovered as a powder, and the handleability is good. On the other hand, if it is 80 degrees C or less, the resin composition with high impact resistance can be obtained.

  In the polymerization of the monomer component constituting each of these layers, particularly the polymerization of the monomer component to obtain the outer layer polymer (C), compatibility with a matrix resin (for example, methacrylic resin), fluidity, It is preferable to use a chain transfer agent such as an alkyl mercaptan in order to improve impact properties. Examples of the alkyl mercaptan include n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan and the like, and 0.1 to 2 parts by mass are used with respect to 100 parts by mass of the monomer component. It is preferable.

  In addition to the above monomer components, each layer may have other monomer components as long as the functions of these components are not impaired, such as a pH adjuster, an antioxidant, and an ultraviolet absorber. These additives can coexist.

  The mass average particle diameter of the polymer formed up to the intermediate layer of such a multilayer structure graft copolymer is 200 to 300 nm, more preferably 230 to 260 nm. If the polymer formed up to the intermediate layer has a mass average particle diameter of 200 nm or more, sufficient impact resistance can be obtained in the resin composition, and if it is 300 nm or less, the resin composition has excellent transparency. It becomes.

  The mass ratio (A) / (B) of the innermost layer polymer (A) and the intermediate layer polymer (B) is 10/90 to 40/60, more preferably 15/85 to 25/75. If the mass of the innermost layer polymer (A) is 10% or more with respect to the total mass of the innermost layer polymer (A) and the intermediate layer polymer (B), a resin using an impact modifier The temperature dependence of the haze of the composition can be suppressed, and if it is 40% or less, the resin composition using an impact modifier can have excellent impact resistance.

  The outer layer polymer (C) is 30 to 100 parts by mass, more preferably 50 to 80 parts by mass when the polymer formed up to the intermediate layer polymer (B) of the multilayer structure graft copolymer is 100 parts by mass. It is. If it is 30 parts by mass or more and 100 parts by mass or less, the resin composition can have excellent impact resistance.

  The mass of the polymer in each layer of the multilayer structure graft copolymer is calculated as the sum of the masses of the monomer components constituting each layer.

  The multilayer structure graft copolymer in the present invention has at least three layers in which the innermost layer, the intermediate layer and the outer layer are sequentially laminated, and a polymer constituting the remaining layers between the respective layers of the three-layer structure. Or you may have a laminated structure provided with the layer comprised with a polymer different from the polymer which comprises these three layers.

  In order to produce such a multilayer structure graft copolymer, for example, the monomer component constituting the innermost layer is emulsion-polymerized to obtain a latex of the polymer, and the monomer component constituting the intermediate layer is added to the latex. In addition, emulsion polymerization is performed to obtain a laminated graft polymer latex. Further, a monomer component constituting the outer layer is added and emulsion polymerization is performed to obtain a multilayer graft polymer latex. The multilayered graft copolymer is recovered from the obtained latex. It can depend on the method. Emulsion polymerization can be performed according to a known method.

  As an emulsifier used for emulsion polymerization, any of an anionic emulsifier, a cationic emulsifier and a nonionic emulsifier can be used, and an anionic emulsifier is particularly preferable. As an anionic emulsifier, carboxylic acid salts such as potassium oleate, sodium stearate, sodium myristate, sodium N-lauroyl sarcosinate, dipotassium alkenyl succinate, sulfate esters such as sodium lauryl sulfate, sodium dioctyl sulfosuccinate, Examples thereof include sulfonates such as sodium dodecylbenzenesulfonate and sodium alkyldiphenyl ether disulfonate, and phosphate esters such as sodium polyoxyethylene alkyl ether phosphate.

  The amount of the emulsifier can be appropriately determined depending on the emulsifier to be used, the type and blending ratio of the monomer component, and the polymerization conditions. It is preferably 5 parts by mass or more. Moreover, in order to suppress the residual amount to a polymer, it is preferable that it is 10 mass parts or less with respect to 100 mass parts of monomer components, especially 5 mass parts or less.

  The polymerization initiator used in the polymerization reaction for forming each layer of the multilayer structure graft copolymer is not particularly limited. For example, as the radical polymerization initiator, benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide Peroxides such as hydrogen peroxide; azo compounds such as azobisisobutyronitrile; persulfate compounds such as potassium persulfate and ammonium persulfate; perchloric acid compounds; perborate compounds; peroxides and reducing sulfoxy Examples thereof include a redox initiator composed of a combination with a compound. The amount of these radical polymerization initiators to be added varies depending on the radical polymerization initiator to be used and the type and blending ratio of the monomer component, but is usually about 0.01 to 10 parts by mass with respect to 100 parts by mass of the monomer component. It is.

  In the production of the multilayer structure graft copolymer, the monomer component and the polymerization initiator can be added by various methods such as a batch addition method, a split addition method, a continuous addition method, a monomer addition method, and an emulsion addition method. . In order to make the reaction proceed smoothly, the reaction system may be replaced with nitrogen, and a residual catalyst may be removed after the reaction is completed by adding a selected catalyst as necessary.

  The amount of the solid content in the latex of the multilayer structure graft copolymer thus obtained is preferably 10% by mass or more, particularly 30% by mass or more in order to increase the productivity of the polymer. The amount of solids in the latex is preferably 60% by mass or less, particularly preferably 50% by mass or less, so as not to impair the stability of the latex.

  Various methods such as an acid coagulation method, a salt coagulation method, a freeze coagulation method, and a spray drying method can be used as a method for recovering the multilayer graft copolymer from the latex. Examples of the recovery agent used in the salt coagulation method include inorganic salts such as aluminum chloride, aluminum sulfate, sodium sulfate, magnesium sulfate, sodium nitrate, and calcium acetate, but an impact resistant resin composition using an impact modifier. In order to suppress coloring of the molded product obtained from the product, calcium acetate is particularly preferable. These are usually used as aqueous solutions. The concentration of the recovery agent aqueous solution is preferably 0.1 to 20% by mass, and more preferably 1 to 15% by mass. If the concentration is too low, the multilayered graft copolymer may not be stably recovered. If the concentration is too high, a large amount of recovery agent remains in the recovered multilayered graft copolymer, resulting in increased coloring. This may reduce the performance of the molded product, which is undesirable. When the latex of the multilayer structure graft copolymer is brought into contact with the recovery agent, if the latex of the hard polymer having a small particle diameter is allowed to coexist, the recovered multilayer structure graft polymer is difficult to block, and the handleability is improved. The temperature at which the latex is brought into contact with the recovery agent aqueous solution is preferably 30 ° C to 100 ° C. The deposited multilayer structure graft copolymer can be washed, dehydrated and dried by various methods. When a lubricant such as silica gel fine particles is added to the dried multilayer structure graft copolymer, the multilayer structure graft polymer becomes difficult to block and handling properties are improved.

  As the impact modifier of the present invention, the above-mentioned multilayer structure graft copolymer can be used as it is, but as long as the action of the multilayer structure graft copolymer is not impaired, an antioxidant, an ultraviolet absorber, and a light stabilizer. In addition, other substances such as additives such as mold release agents may be contained.

  The impact-resistant resin composition of the present invention is not particularly limited as long as it contains a methacrylic resin having methyl methacrylate as a main structural unit and the impact-resistance modifier of the present invention. Such an impact resistant resin composition has excellent impact resistance without impairing the excellent transparency and hardness of the methacrylic resin.

  Examples of the methacrylic resin mainly composed of methyl methacrylate used in the impact-resistant resin composition of the present invention include 50 to 100% by mass of methyl methacrylate and 0 to 50% by mass of other vinyl or vinylidene monomers. The polymer of the monomer component containing% can be illustrated. Examples of other vinyl or vinylidene monomers include alkyl acrylates having an alkyl group having 1 to 4 carbon atoms; aromatic vinyl compounds such as styrene, α-methylstyrene, and vinyl toluene. The methyl methacrylate content in the monomer component is preferably 80 to 99% by mass.

  The mixing ratio of the methacrylic resin and the impact modifier varies depending on the use, but the mass ratio of the methacrylic resin and the impact modifier is preferably 90/10 to 20/80. By making the mass of the impact modifier 10% or more, it becomes possible to make the impact resistance more satisfactory, and by making it 80% or less, the flowability is easy for molding such as injection molding. And the appearance (transparency, etc.) of the molded product is more excellent. More preferably, the mass ratio of the methacrylic resin to the impact modifier is 80/20 to 50/50.

  In addition to the methacrylic resin and impact modifier described above, the impact resistant resin composition of the present invention includes an antioxidant, an ultraviolet absorber, a light stabilizer, a release agent, a pigment, a dye, and the like. May be included.

  Examples of the method for producing the impact-resistant resin composition of the present invention include a method of blending the methacrylic resin and the impact modifier at the above ratio.

Hereinafter, the present invention will be described in more detail with reference to examples. In the examples, “part” represents “part by mass”, and “%” other than haze% represents “% by mass”. Various characteristics of the multilayer structure graft copolymer and the impact-resistant resin composition were carried out according to the following methods.
[Mass average particle diameter]
The mass average particle diameter of the polymer formed up to the intermediate layer polymer (B) in the multilayer structure graft copolymer was measured at a column temperature of 35 ° C. using a CHDF2000 type (trade name) particle size distribution analyzer manufactured by Matec Applied Sciences. The measurement was performed at a carrier liquid flow rate of 1.4 ml / min.
[Evaluation of resin composition]
The obtained resin composition was injection molded under the following conditions, and then various properties were measured.
Apparatus: Nissei Plastic Co., Ltd. PS-60E type (trade name) Injection molding machine Cylinder temperature: 260 ° C
Specimen size: 127mm x 12.7mm x 6.35mm thickness
(For Izod impact strength measurement)
100mm x 50mm x 2mm thickness
(For haze measurement)
[Measurement of Izod impact strength]
The measurement was performed according to ASTM-D-256.
[Measurement of haze] (Evaluation of temperature dependence of haze)
The haze at room temperature (23 ° C.) and 50 ° C. was measured. The measurement was performed according to ASTM-D1003.
[Example 1]
Production of Multilayer Graft Copolymer (1) The following component 1 was placed in a 5-neck flask equipped with a stirrer, reflux condenser, nitrogen blowing port, monomer addition port, and thermometer.
(Component 1)
Deionized water 200 parts SFS (sodium formaldehyde sulfoxylate) 0.4 parts Ferrous sulfate 0.4 × 10 ⁻⁴ parts Disodium ethylenediaminetetraacetate 1.2 × 10 ⁻⁴ parts Next, the system is mixed and stirred Then, the temperature was raised to 80 ° C. while purging with nitrogen, and 4 parts (about 20% by mass of (a-1)) of the mixture (a-1) having the following composition were charged and kept at 80 ° C. 15 Held for a minute. Next, the remainder of (a-1) was added over 50 minutes and held for 1 hour while maintaining at 80 ° C. to complete the polymerization of the innermost layer polymer. The resulting latex (A-1) had a polymerization rate (unreacted monomer was measured by gas chromatography, the same applies hereinafter) of 99% or more.
(Mixture (a-1))
Methyl methacrylate 11.2 parts Styrene 0.8 parts n-Butyl acrylate 8.0 parts 1,3-butanediol dimethacrylate 0.6 parts Allyl methacrylate 0.08 parts t-Butyl hydroperoxide 0.04 parts Emulsifier A ( Polyoxyethylene alkyl ether phosphate ester salt: Phosphanol RS-610NA, trade name, manufactured by Toho Chemical Co., Ltd.) 0.72 parts Subsequently, 0.27 parts of SFS dissolved in 5.0 parts of deionized water In addition to the latex (A-1), after holding for 15 minutes, a mixture (b-1) having the following composition was dropped over 4 hours and held for 2 hours to complete the polymerization of the intermediate layer polymer. It was. The polymerization rate of the obtained latex (B-1) was 99% or more, and the mass average particle diameter of the polymer formed up to the intermediate layer polymer was 250 nm.
(Mixture (b-1))
Styrene 14.0 parts n-Butyl acrylate 66.0 parts Allyl methacrylate 0.72 parts Cumene hydroperoxide 0.23 parts Emulsifier A 2.4 parts Subsequently, 0.23 parts of SFS was dissolved in 5.0 parts of deionized water. The mixture is added to the latex (B-1) and held for 15 minutes, and then the mixture (c-1) having the following composition is dropped over 2 hours and 20 minutes, and held for 1 hour to polymerize the outer layer polymer. Was completed. The final latex (C-1) obtained had a polymerization rate of 99% or more. The Tg of the outer layer polymer is shown in Table 1.
(Mixture (c-1))
Methyl methacrylate 61.7 parts n-Butyl acrylate 7.0 parts Styrene 1.3 parts t-Butyl hydroperoxide 0.12 parts n-octyl mercaptan 0.14 parts Subsequently, 1 as a recovery agent aqueous solution in a stainless steel container Then, 370 parts of a 4% calcium acetate aqueous solution was charged, the temperature was raised to 60 ° C. with mixing and stirring, and 370 parts of the latex (C-1) was continuously added over 10 minutes. Thereafter, the temperature was raised to 90 ° C. and held for 5 minutes. Cool to room temperature, filter with centrifugal dehydration (1300 G, 3 minutes) while washing with deionized water to obtain a wet resin, and dry at 75 ° C. for 48 hours to obtain a white powdered multilayer graft copolymer (1 )
[Preparation and evaluation of resin composition containing impact modifier]
Next, a mixture of 40 parts of the multilayer structure graft copolymer (1) and 60 parts of the methacrylic resin (1) (Acrypet VH, trade name, manufactured by Mitsubishi Rayon Co., Ltd.) was extruded into a biaxial screw type having an outer diameter of 30 mmφ. Machine (Ikegai PCM-30 type (trade name), L / D = 25), melt kneading at a cylinder temperature of 230 ° C. to 260 ° C. and a die temperature of 260 ° C., and [methacrylic resin (1 )] / [Multilayer structure graft copolymer (1)] = 60/40 (mass ratio). Subsequently, a molded body was prepared using the pellets, and Izod impact strength and haze were evaluated. The results are shown in Table 1.
[Examples 2-6 and Comparative Examples 1-3]
Production of multilayer structure graft copolymers (2) to (9) The multilayer structure graft copolymer (1) shown in Example 1 was changed except that the composition of the mixture (c-1) was changed as shown in Table 1. In the same manner as the production method, multilayer structure graft copolymers (2) to (6) were prepared, and (7) to (9) were prepared as comparative examples. The mass average particle diameter of the polymer formed up to the intermediate layer polymer and the Tg of the outer layer polymer are shown in Table 1.
[Preparation and evaluation of resin composition containing impact modifier]
Next, in the same manner as in Example 1, pellets of a resin composition in which [methacrylic resin (1)] / [multilayer structure graft copolymer (2) to (9)] = 60/40 (mass ratio) are obtained. Subsequently, each molded body was produced, and Izod impact strength and haze were evaluated. The results are shown in Table 1.

MMA: methyl methacrylate BA: n-butyl acrylate St: styrene tBH: t-butyl hydroperoxide OcSH: n-octyl mercaptan

[Examples 7 and 8 and Comparative Examples 4 and 5]
Production of multilayer structure graft copolymers (10) to (13) The multilayer structure graft copolymer shown in Example 3 except that the amount of emulsifier A in the mixture (a-1) was changed as shown in Table 2. In the same manner as in the method for producing (3), multilayer structure graft copolymers (10) and (11) were prepared, and (12) and (13) were prepared as comparative examples. Table 2 shows the mass average particle diameter of the polymer formed up to the intermediate layer polymer and the Tg of the outer layer polymer.
[Preparation and evaluation of resin composition containing impact modifier]
Next, in the same manner as in Example 1, pellets of a resin composition in which [methacrylic resin (1)] / [multilayer structure graft copolymer (10) to (13)] = 60/40 (mass ratio) are obtained. Then, each molded body was produced, and Izod impact strength and haze were evaluated. The results are shown in Table 2.

[Examples 9 and 10 and Comparative Examples 6 and 7]
Production of Multilayer Structure Graft Copolymers (14) to (17) The composition ratio of the mixture (a-1) and the mixture (b-1) was not changed, but the use ratio was changed, so that the innermost layer polymer ( A multilayer structure is produced in the same manner as in the method for producing the multilayer graft copolymer (3) shown in Example 3, except that the mass ratio of A) to the intermediate layer polymer (B) is changed as shown in Table 3. Graft copolymers (14) and (15) were prepared, and (16) and (17) were prepared as comparative examples. Table 3 shows the mass average particle diameter of the polymer formed up to the intermediate layer polymer and the Tg of the outer layer polymer.
[Preparation and evaluation of resin composition containing impact modifier]
Next, in the same manner as in Example 1, pellets of a resin composition in which [methacrylic resin (1)] / [multilayer structure graft copolymer (14) to (17)] = 60/40 (mass ratio) are obtained. Then, each molded body was produced, and Izod impact strength and haze were evaluated. The results are shown in Table 3.

[Examples 11 and 12 and Comparative Examples 8 and 9]
Production of multilayer structure graft copolymers (18) to (21) The multilayer structure graft copolymer shown in Example 3 except that the amount of allyl methacrylate in the mixture (b-1) was changed as shown in Table 4. In the same manner as in the production of (3), multilayer structure graft copolymers (18) and (19) were prepared, and (20) and (21) were prepared as comparative examples. Table 4 shows the mass average particle diameter of the polymer formed up to the intermediate layer polymer and the Tg of the outer layer polymer.
[Preparation and evaluation of resin composition containing impact modifier]
Next, in the same manner as in Example 1, pellets of a resin composition in which [methacrylic resin (1)] / [multilayer structure graft copolymer (18) to (21)] = 60/40 (mass ratio) are obtained. Then, each molded body was produced, and Izod impact strength and haze were evaluated. The results are shown in Table 4.

  As described above, it has been found that the impact resistance modifier satisfying the configuration of the present invention suppresses the transparency, in particular, the temperature dependence of haze, and has a high impact resistance improving effect. Moreover, it was found that the resin composition using the impact modifier has high impact resistance and can suppress the temperature dependency of transparency and haze.

The resin composition of the present invention is excellent in impact resistance, transparency, weather resistance and molding processability, and can be widely used for automobile parts, lighting products, various panels and the like.

Claims (2)

An impact modifier comprising a multilayered graft copolymer in which an innermost layer, an intermediate layer and an outer layer are sequentially laminated,
The innermost layer of the multilayer structure graft copolymer is composed of 40 to 100% by mass of alkyl methacrylate having 1 to 4 carbon atoms in the alkyl group, 0 to 60% by mass of alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, and others. Is obtained by polymerizing a monomer component containing 100 parts by mass of a monomer mixture consisting of 0 to 20% by mass of a copolymerizable monomer and 0.1 to 10 parts by mass of a polyfunctional monomer. It consists of an inner layer polymer (A),
In the presence of the innermost layer polymer (A), the intermediate layer is an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms of 70 to 90% by mass, an aromatic vinyl compound of 10 to 30% by mass, and other copolymers. It is obtained by polymerizing a monomer component containing 100 parts by mass of a monomer mixture composed of 0 to 20% by mass of a possible monomer and 0.1 parts by mass or more and less than 1 part by mass of a polyfunctional monomer. It consists of an intermediate layer polymer (B),
In the presence of the polymer formed by the outer layer up to the intermediate layer polymer (B), the alkyl methacrylate having 50 to 100% by mass of alkyl methacrylate having 1 to 4 carbon atoms and the alkyl acrylate having 1 to 8 carbon atoms of alkyl group. An outer layer weight obtained by polymerizing a monomer component containing 0 to 50% by mass and 0 to 20% by mass of other copolymerizable monomers and having a glass transition point (Tg) of 20 to 80 ° C. Consisting of coalescence (C),
The mass average particle diameter of the polymer formed up to the intermediate layer is 200 to 300 nm,
The mass ratio (A) / (B) of the innermost layer polymer (A) and the intermediate layer polymer (B) is 10/90 to 40/60,
The impact modifier is characterized in that the outer layer polymer (C) is 30 to 100 parts by mass when the total of the innermost layer polymer (A) and the intermediate layer polymer (B) is 100 parts by mass. . The impact-resistant resin composition containing the methacrylic resin which has methyl methacrylate as a main structural unit, and the impact-resistance modifier of Claim 1.