WO2018123662A1

WO2018123662A1 - Film

Info

Publication number: WO2018123662A1
Application number: PCT/JP2017/045149
Authority: WO
Inventors: 宏晃周; 浩成摺出寺
Original assignee: 日本ゼオン株式会社
Priority date: 2016-12-28
Filing date: 2017-12-15
Publication date: 2018-07-05
Also published as: JPWO2018123662A1; TW201834855A; KR20190100916A; CN109963712A

Abstract

A film which comprises a substrate film and a slippery layer that is provided on the substrate film, and wherein: the substrate film contains a block copolymer; the block copolymer comprises a block having an aromatic vinyl compound hydride unit and a block having a diene compound hydride unit; the sum of the number of the blocks having an aromatic vinyl compound hydride unit and the number of the blocks having a diene compound hydride unit is 3 or more per one molecule of the block copolymer; and the slippery layer is formed of a cured product a composition that contains a polyurethane, a crosslinking agent which is able to cause crosslinking of the polyurethane, a nonvolatile base and fine particles.

Description

the film

The present invention relates to a film.

A display device such as a liquid crystal display device is provided with various optical elements such as a polarizing plate and a retardation plate. Some of these optical elements are made of a film (see, for example, Patent Documents 1 to 3).

JP 2000-169521 A (corresponding to other countries: US Pat. No. 6,433,102) JP 2001-48924 (corresponding to other countries: US Pat. No. 6,686,430) JP 2002-105151 A (corresponding to other countries: US Patent Application Publication No. 2003/207983)

By the way, a polarizing plate protective film is usually provided in a polarizing plate among optical elements. This polarizing plate protective film is required to have a small in-plane retardation (also referred to as retardation) and excellent impact resistance.
However, in the prior art, there is a tendency that a retardation is easily developed in the film production process, and it is difficult to realize a film that achieves the characteristics that the in-plane retardation is small and the impact resistance is excellent. .
Moreover, a polarizing plate protective film and a polarizing plate may be preserve | saved and conveyed in the shape of a elongate film roll. When the polarizing plate protective film or the like is formed in the shape of a film roll, since the adjacent surfaces of the film come into contact with each other at a high pressure in the film roll during storage, a phenomenon occurs in which these adhere to each other. Such a phenomenon is called blocking, and when blocking occurs, the film can be wound poorly. Therefore, in addition to the achievement of the above characteristics, realization of a film that suppresses the occurrence of blocking is also required.

The present invention has been made in view of the above, and an object of the present invention is to provide a film having a small in-plane retardation, excellent impact resistance, and suppressing occurrence of blocking.

In order to solve the above-described problems and achieve the object, the present inventor has intensively studied, and as a result, has a block having an aromatic vinyl compound hydride unit and a block having a diene compound hydride unit at a predetermined number of blocks or more. In a laminated film comprising a base material containing a block copolymer, a polyurethane, a crosslinking agent, a non-volatile base, and an easy-sliding layer made of a cured product of a composition containing fine particles, The inventors have found that the phase difference is small, the impact resistance is excellent, and the occurrence of blocking is suppressed, and the present invention has been completed.
That is, according to the present invention, the following [1] to [5] are provided.

[1] A base film and an easy-slip layer provided on the base film,
The base film includes a block copolymer,
The block copolymer has a block having an aromatic vinyl compound hydride unit and a block having a diene compound hydride unit;
The sum of the number of blocks having the aromatic vinyl compound hydride unit and the number of blocks having the diene compound hydride is 3 or more per molecule of the block copolymer;
The easy-sliding layer is a film made of a cured product of a composition containing polyurethane, a crosslinking agent capable of crosslinking the polyurethane, a non-volatile base, and fine particles.
[2] In the block copolymer,
The content of the block having the aromatic vinyl compound hydride unit is 80% by weight to 90% by weight, the content of the block having the diene compound hydride unit is 10% by weight to 20% by weight,
[1] The film according to [1], wherein at least one end of the polymer chain comprises a block having the aromatic vinyl compound hydride unit.
[3] The film according to [1] or [2], wherein the in-plane retardation has an absolute value of 1 nm or less and a thickness direction retardation has an absolute value of 1 nm or less.
[4] The film according to any one of [1] to [3], which is a stretched film.
[5] The tensile modulus of the polyurethane is 1000 N / mm ² or more 5000N / mm ² or less, according to any one of [1] to [4] film.
[6] The film according to any one of [1] to [5], wherein the polyurethane is a polyether-based polyurethane.

The film of the present invention has a small in-plane retardation, excellent impact resistance, and suppresses the occurrence of blocking.

Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and exemplifications, and can be implemented with any modifications without departing from the scope of the claims of the present invention and the equivalents thereof.

In the following description, unless otherwise indicated, the particle size distribution is measured by laser diffraction method, and the cumulative volume calculated from the small diameter side in the measured particle size distribution is 50%. Adopt particle size.

The “polarizing plate” includes not only a rigid member but also a flexible member such as a resin film.

The film of the present invention includes a base film and an easy-sliding layer provided on the base film. In the present invention, the base film contains a block copolymer, and the easy-sliding layer is a layer made of a cured product of a composition containing polyurethane, a crosslinking agent capable of crosslinking the polyurethane, a nonvolatile base and fine particles. is there. Hereinafter, the composition containing the polyurethane, the crosslinking agent, the nonvolatile base and the fine particles may be referred to as a “urethane composition”.

[1. Base film]
The base film includes a block copolymer. The block copolymer contained in the base film has a block having an aromatic vinyl compound hydride unit and a block having a diene compound hydride unit. The total number of blocks having aromatic vinyl compound hydride units and blocks having diene compound hydrides is 3 or more per molecule of block copolymer.

[1.1. Block copolymer]
Aromatic vinyl compound hydride unit refers to a repeating unit having the same structure as the repeating unit of a polymer obtained by polymerizing an aromatic vinyl compound and then hydrogenating its unsaturated bond. It refers to the repeating unit represented by (1). However, the aromatic vinyl compound hydride unit is not limited depending on the production method.
A block having an aromatic vinyl compound hydride unit (hereinafter also referred to as “aromatic vinyl compound hydride block”) is a block having such an aromatic vinyl compound hydride unit.

In the structural formula (1), R ^c represents an alicyclic hydrocarbon group. Examples of R ^c include cyclohexyl groups such as cyclohexyl group; decahydronaphthyl groups and the like.

In the structural formula (1), R ¹ , R ² and R ³ are each independently a hydrogen atom, a chain hydrocarbon group, a halogen atom, an alkoxy group, a hydroxyl group, an ester group, a cyano group, an amide group or an imide group. Represents a chain hydrocarbon group substituted with a silyl group or a polar group (halogen atom, alkoxy group, hydroxyl group, ester group, cyano group, amide group, imide group, or silyl group). Among them, R ¹ , R ² and R ³ are preferably a hydrogen atom and a chain hydrocarbon group having 1 to 6 carbon atoms from the viewpoints of heat resistance, low birefringence and mechanical strength. The chain hydrocarbon group is preferably a saturated hydrocarbon group, and more preferably an alkyl group.

The molecular weight of the aromatic vinyl compound hydride block is usually 1000 or more, preferably 2000 or more, more preferably 3000 or more, and usually 100,000 or less, preferably 90000 or less, more preferably 80000 or less. The advantage that the elastic modulus of the film is improved by the molecular weight of the aromatic vinyl compound hydride block being not less than the lower limit of the above range, and the impact resistance of the film is improved by being not more than the upper limit. Is obtained. Moreover, when there are a plurality of aromatic vinyl compound hydride blocks, the molecular weight of each block can be set to a value within the above range. In this case, the molecular weight of each block may be the same or different.

Examples of repeating units of aromatic vinyl compound hydride blocks include the following. Any of the following isomers having stereoisomers can be used. Moreover, the repeating unit of an aromatic vinyl compound hydride block may use only 1 type, and may use it combining 2 or more types by arbitrary ratios. Furthermore, only one type of aromatic vinyl compound hydride block may be used, or two or more types may be used in combination at any ratio.

The content of the aromatic vinyl compound hydride block contained in the block copolymer is preferably 80% by weight or more, more preferably 82% by weight or more, preferably 90% by weight or less, more preferably 88% by weight. It is as follows. By setting the content of the aromatic vinyl compound hydride block in the above range, the retardation Re in the surface direction of the base film can be set in a desired range.

In the block copolymer, preferably, one end of the polymer chain, more preferably a plurality of ends of the polymer chain, is composed of an aromatic vinyl compound hydride block. Thereby, impact resistance can be improved. It can be confirmed by NMR method that the terminal of the polymer chain is composed of an aromatic vinyl compound hydride block.

The diene compound hydride unit has the same structure as the repeating unit of the polymer obtained by polymerizing the diene compound and then hydrogenating the unsaturated bond if the polymer obtained has an unsaturated bond. Refers to a repeating unit having Especially, it is preferable that a diene compound hydride unit is a repeating unit which has the structure similar to the repeating unit of the polymer obtained by polymerizing a conjugated diene compound and hydrogenating the unsaturated bond. When the example is given, the repeating unit represented, for example by the following structural formula (2) or structural formula (3) will be mentioned. However, the diene compound hydride unit is not limited depending on the production method.
A block having a diene compound hydride unit (hereinafter also referred to as “diene compound hydride block”) is a block having such a diene compound hydride unit.

In the structural formula (2), R ⁴ to R ⁹ are each independently a hydrogen atom, a chain hydrocarbon group, a halogen atom, an alkoxy group, a hydroxyl group, an ester group, a cyano group, an amide group, an imide group, or a silyl group. Or a chain hydrocarbon group substituted with a polar group (halogen atom, alkoxy group, hydroxyl group, ester group, cyano group, amide group, imide group, or silyl group). Among these, R ⁴ to R ⁹ are preferably a hydrogen atom and a chain hydrocarbon group having 1 to 6 carbon atoms from the viewpoints of heat resistance, low birefringence, mechanical strength, and the like. The chain hydrocarbon group is preferably a saturated hydrocarbon group, and more preferably an alkyl group.

In the structural formula (3), R ¹⁰ to R ¹⁵ each independently represent a hydrogen atom, a chain hydrocarbon group, a halogen atom, an alkoxy group, a hydroxyl group, an ester group, a cyano group, an amide group, an imide group, or a silyl group. Or a chain hydrocarbon group substituted with a polar group (halogen atom, alkoxy group, hydroxyl group, ester group, cyano group, amide group, imide group, or silyl group). Among them, R ¹⁰ to R ¹⁵ are preferably a hydrogen atom and a chain hydrocarbon group having 1 to 6 carbon atoms from the viewpoint of heat resistance, low birefringence, mechanical strength, and the like. The chain hydrocarbon group is preferably a saturated hydrocarbon group, and more preferably an alkyl group.

The molecular weight of the diene compound hydride block is usually 500 or more, preferably 1000 or more, more preferably 2000 or more, and usually 50000 or less, preferably 30000 or less, more preferably 20000 or less. When the molecular weight of the diene compound hydride block is not less than the lower limit of the above range, an advantage that the impact resistance is improved is obtained, and when it is not more than the upper limit, an advantage that the elastic modulus is improved is obtained. Moreover, when there are a plurality of diene compound hydride blocks, the molecular weight of each block can be set to a value within the above range. In this case, the molecular weight of each block may be the same or different.

Examples of the repeating unit of the diene compound hydride block include the following examples. Any of the following isomers having stereoisomers can be used. Moreover, only one type of repeating unit of the diene compound hydride block may be used, or two or more types may be used in combination at any ratio. Furthermore, only one type of diene compound hydride block may be used, or two or more types may be used in combination at any ratio.

The content of the diene compound hydride block contained in the block copolymer is preferably 10% by weight or more, more preferably 12% by weight or more, preferably 20% by weight or less, more preferably 18% by weight or less. is there. By setting the content of the diene compound hydride block in the above range, the retardation Re in the surface direction can be set to a desired range in the base film.

The block copolymer has a total of three or more aromatic vinyl compound hydride blocks and diene compound hydride blocks per molecule. By having a total of 3 (3 blocks) or more of aromatic vinyl compound hydride blocks and diene compound hydride blocks per molecule, it is possible to improve impact resistance. Moreover, the heat resistance of a base film can also be improved normally. On the other hand, the upper limit is arbitrary as long as the effects of the present invention are not significantly impaired, but it is preferably 5 blocks or less, more preferably 4 blocks or less. This is because if the number of blocks is too large, impact resistance tends to decrease. In the present invention, the block copolymer preferably has three blocks per molecule (triblock structure).

The block copolymer may have other arbitrary blocks in addition to the aromatic vinyl compound hydride block and diene compound hydride block as long as the effects of the present invention are not significantly impaired. However, from the viewpoint of exhibiting the effects of the present invention more remarkably, it is preferable that the number of arbitrary blocks is small. The specific content of the arbitrary block is not uniform depending on the use of the film and the like, but is usually 10% by weight or less, preferably 5% by weight or less, more preferably 3% by weight or less, and it is particularly preferable not to contain it. .

Examples of the arbitrary block include a copolymer block having an aromatic vinyl compound hydride unit and a diene compound hydride unit. Examples of the aromatic vinyl compound hydride unit in the copolymer block include those similar to the repeating unit of the aromatic vinyl compound hydride block, and the diene compound hydride unit includes the repeating unit of the diene compound hydride block. The same thing is mentioned.

The weight average molecular weight Mw of the block copolymer is usually 50,000 or more, preferably 55,000 or more, more preferably 60,000 or more, and usually 100,000 or less, preferably 90,000 or less, more preferably 80,000 or less. When the weight average molecular weight Mw is not less than the lower limit of the above range, the impact resistance of the film can be improved, and when it is not more than the upper limit, the viscosity of the polymer can be lowered and the moldability can be improved.

The molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the block copolymer is usually 2 or less, preferably 1.5 or less, more preferably 1.2 or less. Thereby, a polymer viscosity can be lowered | hung and a moldability can be improved.

The glass transition temperature Tg _A of the block copolymer is usually 110 ° C. or higher, preferably 115 ° C. or higher, more preferably 120 ° C. or higher, and usually 150 ° C. or lower, preferably 148 ° C. or lower, more preferably 145 ° C. or lower. is there. The advantage that the heat resistance of the film is improved when the glass transition temperature of the block copolymer is at least the lower limit of the above range is obtained, and the advantage that the processing temperature is lowered and the moldability is improved by being below the upper limit. It is done. As the glass transition temperature Tg _A of the block copolymer, a higher numerical value can be adopted when a plurality of glass transition temperatures are observed.

The tensile modulus of the block copolymer is usually 1,500 N / mm ² or more, preferably 1,600 N / mm ² or more, usually 2,500 N / mm ² or less, preferably 2,200 N / mm ² or less. is there. The advantage that the elasticity of the film is obtained when the tensile modulus of the block copolymer is not less than the lower limit of the above range is obtained, and the impact resistance of the film is improved by being not more than the upper limit. can get.

[1.2. Method for producing block copolymer]
There is no limitation on the method for producing the block copolymer. For example, a monomer corresponding to each of the aromatic vinyl compound hydride block and the diene compound hydride block is prepared, and this is subjected to block polymerization to obtain a polymer. Then, the obtained polymer may be hydrogenated.

Examples of monomers corresponding to the aromatic vinyl compound hydride block include styrene, α-methylstyrene, α-ethylstyrene, α-propylstyrene, α-isopropylstyrene, α-t-butylstyrene, 2- Methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene, monochlorostyrene, dichlorostyrene Styrenes such as monofluorostyrene and 4-phenylstyrene; vinylcyclohexanes such as vinylcyclohexane and 3-methylisopropenylcyclohexane; 4-vinylcyclohexene, 4-isopropenylcyclohexene, 1-methyl-4-vinylcyclohexene, 1 -Methyl-4-isop And vinylcyclohexenes such as lopenylcyclohexene, 2-methyl-4-vinylcyclohexene and 2-methyl-4-isopropenylcyclohexene.
One type of monomer corresponding to the aromatic vinyl compound hydride block may be used alone, or two or more types may be used in combination at any ratio.

On the other hand, examples of monomers corresponding to diene compound hydride blocks include chains such as butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. And conjugated dienes.
As the monomer corresponding to the diene compound hydride block, one type may be used alone, or two or more types may be used in combination at any ratio.

In general, anionic polymerization can be employed for the polymerization.
The polymerization may be performed by any of bulk polymerization and solution polymerization. Among these, solution polymerization is preferable in order to continuously perform the polymerization reaction and the hydrogenation reaction.

Examples of the reaction solvent for polymerization include aliphatic hydrocarbons such as n-butane, n-pentane, isopentane, n-hexane, n-heptane, and isooctane; cyclopentane, cyclohexane, methylcyclopentane, methylcyclohexane, decalin, etc. And alicyclic hydrocarbons; aromatic hydrocarbons such as benzene and toluene. Of these, the use of aliphatic hydrocarbons and alicyclic hydrocarbons is preferable because they can be used as they are as an inert solvent for the hydrogenation reaction.
A reaction solvent may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.
The reaction solvent is usually used at a ratio of 200 to 10,000 parts by weight with respect to 100 parts by weight of the total monomers.

During polymerization, a polymerization initiator is usually used. Examples of the polymerization initiator include monoorganolithium such as n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium and phenyllithium; dilithiomethane, 1,4-diobtan, 1,4-dilithio-2-ethyl And polyfunctional organolithium compounds such as cyclohexane. A polymerization initiator may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

When polymerizing each polymer block, a polymerization accelerator, a randomizer, or the like can be used in order to prevent an excessively long chain of one component in each block. For example, when the polymerization is performed by anionic polymerization, a Lewis base compound or the like can be used as a randomizer. Specific examples of Lewis base compounds include dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, diphenyl ether, ethylene glycol diethyl ether, ethylene glycol methyl phenyl ether, and other ether compounds; tetramethylethylenediamine, trimethylamine, triethylamine, pyridine, and the like. Tertiary amine compounds; alkali metal alkoxide compounds such as potassium-t-amyl oxide and potassium-t-butyl oxide; and phosphine compounds such as triphenylphosphine. One of these may be used alone, or two or more of these may be used in combination at any ratio.

The polymerization temperature is not limited as long as the polymerization proceeds, but is usually 0 ° C. or higher, preferably 20 ° C. or higher, and is usually 200 ° C. or lower, preferably 100 ° C. or lower, more preferably 80 ° C. or lower.

After the polymerization, the polymer can be recovered by a known method such as a steam stripping method, a direct desolvation method, or an alcohol coagulation method. Further, when a solvent inert to the hydrogenation reaction is used as the reaction solvent during the polymerization, the polymer can be used as it is without recovering the polymer from the polymerization solution.

There is no limitation on the method for hydrogenating the polymer, and for example, an appropriate hydrogenation catalyst may be used. For example, a hydrogenation catalyst containing at least one metal selected from the group consisting of nickel, cobalt, iron, titanium, rhodium, palladium, platinum, ruthenium, and rhenium may be used in an organic solvent. As the hydrogenation catalyst, either a heterogeneous catalyst or a homogeneous catalyst can be used. Moreover, a hydrogenation catalyst may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

The heterogeneous catalyst may be used as it is as a metal or a metal compound, or may be used by being supported on an appropriate carrier. Examples of the carrier include activated carbon, silica, alumina, calcium carbide, titania, magnesia, zirconia, diatomaceous earth, silicon carbide and the like. The amount of the catalyst supported on the carrier is usually 0.01% by weight or more, preferably 0.05% by weight or more, and usually 80% by weight or less, preferably 60% by weight or less.
The homogeneous catalyst is, for example, a catalyst in which a compound of nickel, cobalt, titanium or iron and an organometallic compound (for example, organoaluminum compound, organolithium compound) is combined; organometallic such as rhodium, palladium, platinum, ruthenium and rhenium Complex catalyst; and the like. Examples of the nickel, cobalt, titanium, or iron compound include acetylacetone salts, naphthenic acid salts, cyclopentadienyl compounds, cyclopentadienyl dichloro compounds of various metals, and the like. Examples of the organic aluminum compound include alkylaluminums such as triethylaluminum and triisobutylaluminum; aluminum halides such as diethylaluminum chloride and ethylaluminum dichloride; alkylaluminum hydrides such as diisobutylaluminum hydride; and the like.
Examples of organometallic complex catalysts include metal complexes such as γ-dichloro-π-benzene complexes, dichloro-tris (triphenylphosphine) complexes, hydrido-chloro-triphenylphosphine) complexes of the above metals. .
The amount of the hydrogenation catalyst used is usually 0.01 parts by weight or more, preferably 0.05 parts by weight or more, more preferably 0.1 parts by weight or more, and usually 100 parts by weight with respect to 100 parts by weight of the polymer. Hereinafter, it is preferably 50 parts by weight or less, more preferably 30 parts by weight or less.

The reaction temperature during the hydrogenation reaction is usually 10 ° C. to 250 ° C., but is preferably 50 ° C. or more, more preferably, because the hydrogenation rate can be increased and the polymer chain scission reaction can be reduced. It is 80 degreeC or more, Preferably it is 200 degrees C or less, More preferably, it is 180 degrees C or less. The pressure during the reaction is usually 0.1 MPa to 30 MPa, but in addition to the above reasons, from the viewpoint of operability, it is preferably 1 MPa or more, more preferably 2 MPa or more, preferably 20 MPa or less, more preferably 10 MPa or less.
The hydrogenation rate is usually 90% or more, preferably 95% or more, more preferably 97% or more. By increasing the hydrogenation rate, the low birefringence and thermal stability of the block copolymer can be enhanced. The hydrogenation rate can be measured by ¹ H-NMR.

[1.3. Base film]
The base film may be a single-layer film including only one layer, or may be a multilayer film having two or more layers. When the base film has a multilayer structure, at least one of the layers provided in the base film is a layer containing a block copolymer.

The base film may contain an optional component other than the block copolymer as long as the effects of the present invention are not significantly impaired. Examples of optional components include: UV absorbers; inorganic fine particles; stabilizers such as antioxidants, heat stabilizers and near infrared absorbers; resin modifiers such as lubricants and plasticizers; colorants such as dyes and pigments An antistatic agent or the like. One type of optional component may be included, and two or more types may be included in any ratio and combination. However, the amount of the optional component is preferably small from the viewpoint of remarkably exhibiting the effects of the present invention. The specific amount of the optional component depends on the use and thickness of the film of the present invention, but is preferably 10 parts by weight or less, more preferably 5 parts by weight or less, for example, with respect to 100 parts by weight of the block copolymer. More preferred are parts by weight or less.

The thickness of the base film is usually 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more, and usually 200 μm or less, preferably 100 μm or less, more preferably 50 μm or less. When used as a polarizing plate protective film by making the thickness of the substrate film above the lower limit of the above range, there is an advantage that handling properties such as prevention of damage to the polarizing plate are improved, and by making the thickness below the upper limit, the polarizing plate There is an advantage that it can be made thin.

The thickness variation of the base film is preferably within ± 1 μm on the entire surface. When the variation in the thickness of the base film is within ± 1 μm on the entire surface, the variation in the color tone of the film of the present invention is reduced. In addition, since the color tone change after long-term use is uniform, color tone unevenness after long-term use hardly occurs.

The base film is usually a transparent layer and transmits visible light well. The specific light transmittance is not uniform depending on the application of the film of the present invention, but the light transmittance at a wavelength of 420 to 780 nm is usually 85% or more, preferably 88% or more. Since the base film has such a high light transmittance at a wavelength of 420 to 780 nm, when the film of the present invention is mounted on a display device such as a liquid crystal display device, it is possible to suppress a decrease in luminance particularly during long-term use. .

[2. Easy-slip layer]
The easy-sliding layer is a layer made of a cured product of a urethane composition containing polyurethane, a crosslinking agent capable of crosslinking the polyurethane, a non-volatile base and fine particles. By using an easy-sliding layer made of a cured product of such a urethane composition, the occurrence of blocking can be suppressed even when the film of the present invention is stored and transported in the form of a long film roll. . Moreover, this easy-sliding layer can maintain the excellent adhesiveness for a long time in a high-humidity environment.

[2.1. Polyurethane]
Tensile modulus of the polyurethane is preferably 1000 N / mm ² or more, more preferably 1200 N / mm ² or more, particularly preferably 1400 N / mm ² or more, preferably 5000N / mm ² or less, more preferably 4000 N / mm ² Hereinafter, it is particularly preferably 3000 N / mm ² or less. By using polyurethane having a tensile elastic modulus equal to or higher than the lower limit of the above range, the adhesion of the easy-adhesion layer can be increased. Moreover, since it can prevent that a slippery layer becomes too hard by setting it as an upper limit or less, damage to a slippery layer can be prevented.

The tensile modulus of elasticity of the polyurethane described above is a value measured before being mixed with a component such as a crosslinking agent and a non-volatile base. A specific method for measuring the tensile modulus of polyurethane is as follows.
First, an aqueous dispersion of polyurethane (a solution may be used if necessary) is prepared as a sample. This aqueous dispersion is poured into a glass container so that the film thickness after drying is 100 μm. After leaving at room temperature for 24 hours, it is dried at 50 ° C. for 3 hours and at 120 ° C. for 20 minutes to obtain a polyurethane sheet.
The obtained polyurethane sheet is punched into a dumbbell according to JIS K7162, and a test piece is obtained.
This test piece is subjected to a tensile test using a tensile tester at a tensile speed of 5 mm / min, and the tensile elastic modulus is measured from the slope of the obtained stress-strain curve (SS curve).

The tensile modulus of polyurethane can be controlled, for example, by adjusting the type and ratio of the polyurethane monomer. Specific examples of the method for controlling the tensile modulus include: (2) polyether polyol, (3) polyester polyol, (4) polyether ester polyol, and (5) polycarbonate, which will be described later, among monomers used as raw materials for polyurethane. The tensile elastic modulus of the polyurethane can be adjusted by adjusting the type and charging ratio of the macropolyol such as polyol.

As the polyurethane, for example, polyurethane obtained by reacting (i) a component containing an average of 2 or more active hydrogens in one molecule and (ii) a polyisocyanate component can be used.
In addition, as the polyurethane, for example, an isocyanate group-containing prepolymer obtained by urethanizing the component (i) and the component (ii) is chain-extended using a chain extender, and water is added to the dispersion. The polyurethane produced by the above can be used. The prepolymer can be obtained by subjecting the component (i) and the component (ii) to a urethanization reaction under an excess of isocyanate groups. The urethanization reaction can be performed in an organic solvent that is inert to the reaction and has a high affinity for water. Furthermore, the prepolymer may be neutralized before the chain extension of the prepolymer. Examples of the chain extension method of the isocyanate group-containing prepolymer include a method in which the isocyanate group-containing prepolymer and the chain extender are reacted in the presence of a catalyst as necessary. In this case, water, water-soluble polyamine, glycols, etc. can be used as the chain extender.

As the component (i), those having hydroxyl group active hydrogen are preferable, and for example, compounds having an average of two or more hydroxyl groups in one molecule are preferable. Specific examples of the component (i) include the following (1) polyol compound, (2) polyether polyol, (3) polyester polyol, (4) polyether ester polyol, and (5) polycarbonate polyol.

(1) Polyol compound:
Examples of the polyol compound include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol, 1,5 -Pentanediol, neopentyl glycol, 1,6-hexane glycol, 2,5-hexanediol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, tricyclodecane dimethanol, 1,4 -Cyclohexanedimethanol, 2,2-dimethylpropanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octamethylenediol, glycerin, trimethylolpropane and the like.

(2) Polyether polyol:
Examples of polyether polyols include alkylene oxide adducts of the above polyol compounds; ring-opening (co) polymers of alkylene oxides and cyclic ethers (eg, tetrahydrofuran); polyethylene glycol, polypropylene glycol, ethylene glycol-propylene glycol copolymers 1,4-butanediol copolymer; glycols such as glycol, polytetramethylene glycol, polyhexamethylene glycol, polyoctamethylene glycol; and the like. Specific examples of the polyether polyol include poly (oxypropylene ether) polyol, poly (oxyethylene-propylene ether) polyol, and the like.

(3) Polyester polyol:
Examples of the polyester polyol include those obtained by polycondensation of a polyvalent carboxylic acid or an anhydride thereof and the above (1) polyol compound under an excessive hydroxyl group condition. Examples of the polyvalent carboxylic acid include dicarboxylic acids such as adipic acid, succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, and terephthalic acid; and tricarboxylic acids such as trimellitic acid. Is mentioned. Specific examples of polyester polyols include ethylene glycol-adipic acid condensate, butanediol-adipine condensate, hexamethylene glycol-adipic acid condensate, ethylene glycol-propylene glycol-adipic acid condensate, or glycol as an initiator. And polylactone diol obtained by ring-opening polymerization of lactone.

(4) Polyether ester polyol:
As the polyether ester polyol, for example, an ether group-containing polyol or a mixture of this and another glycol is mixed with a polyvalent carboxylic acid or anhydride thereof as exemplified in the above (3) and reacted with an alkylene oxide. And the like. Examples of the ether group-containing polyol include (2) polyether polyol and diethylene glycol. Specific examples of the polyether ester polyol include polytetramethylene glycol-adipic acid condensate.

(5) Polycarbonate polyol:
Examples of the polycarbonate polyol include a general formula HO—R— (O—C (O) —O—R) _X —OH (wherein R represents a saturated fatty acid polyol residue having 1 to 12 carbon atoms). X represents the number of structural units of the molecule, and is usually an integer of 5 to 50). These are a transesterification method in which a saturated aliphatic polyol and a substituted carbonate (for example, diethyl carbonate, diphenyl carbonate, etc.) are reacted under conditions where the hydroxyl group becomes excessive; the saturated aliphatic polyol and phosgene are reacted, Or, if necessary, it can be obtained by a method of further reacting a saturated aliphatic polyol thereafter.

These components (i) may be used alone or in combination of two or more at any ratio.

Examples of the component (ii) to be reacted with the component (i) (that is, the polyisocyanate component) include compounds containing an average of 2 or more isocyanate groups in one molecule. This compound may be an aliphatic compound, an alicyclic compound, or an aromatic compound.
The aliphatic polyisocyanate compound is preferably an aliphatic diisocyanate having 1 to 12 carbon atoms, and examples thereof include hexamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate, and hexane diisocyanate (HDI).
The alicyclic polyisocyanate compound is preferably an alicyclic diisocyanate having 4 to 18 carbon atoms, such as 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), etc. Is mentioned.
Examples of the aromatic polyisocyanate include tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, and the like.

These (ii) components may be used alone or in combination of two or more at any ratio.

The above (i) component and (ii) component can be arbitrarily selected and used depending on the application of the film of the present invention. Among them, as the component (i), it is preferable to use a component having a bond that is difficult to hydrolyze. Specifically, (2) polyether polyol and (5) polycarbonate polyol are preferable, and (2) polyether polyol is particularly preferable. Particularly preferred. Polyurethane using (2) polyether polyol as component (i) is called “polyether polyurethane”. In addition, polyurethane using (5) polycarbonate polyol as component (i) is called “polycarbonate polyurethane”. These polyether-based polyurethane and polycarbonate-based polyurethane have an ether bond or a carbonate bond that is difficult to hydrolyze. Therefore, since polyurethane hardly deteriorates in a high-humidity environment, it is possible to suppress a temporal decrease in the tensile elastic modulus of the slippery layer. Therefore, it is possible to effectively suppress a decrease in adhesiveness in a high humidity environment.

These polyurethanes may contain an acid structure in the molecular structure. Polyurethane containing an acid structure can be dispersed in water without using a surfactant or even if the amount of the surfactant is small. . This is called a self-emulsifying type, and means that polyurethane particles can be dispersed and stabilized in water with only molecular ionicity even without a surfactant. Moreover, since the polyurethane containing an acid structure does not require or requires a small amount of a surfactant, it has excellent adhesion to a base film and can maintain high transparency.

Examples of the acid structure include acid groups such as a carboxyl group (—COOH) and a sulfo group (—SO ₃ H). In addition, the acid structure may be present in the side chain or at the terminal in the polyurethane. One type of acid structure may be used, or two or more types may be used in combination at any ratio.

The amount of the acid structure is preferably 20 mgKOH / g or more, more preferably 25 mgKOH / g or more, preferably 250 mgKOH / g or less, more preferably 150 mgKOH / g or less as the acid value in the urethane composition. By setting the acid value to be equal to or higher than the lower limit of the above range, the water dispersibility of the polyurethane can be improved. Moreover, the water resistance of a slippery layer can be made favorable by setting it as an upper limit or less.

As a method for introducing an acid structure into polyurethane, for example, by replacing dimethylol alkanoic acid with a part or all of the component (i) described in the above (2) to (4), a polyether polyol or a polyester may be used in advance. The method of introduce | transducing a carboxyl group into a polyol, polyetherester polyol, etc. is mentioned. Examples of the dimethylol alkanoic acid used here include dimethylol acetic acid, dimethylol propionic acid, and dimethylol butyric acid. A dimethylol alkanoic acid may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

In the urethane composition, part or all of the acid structure contained in the polyurethane is neutralized by a nonvolatile base. Because the acid structure is neutralized, the film maintains its properties as an optical material even when it has a thermal history exposed to high temperatures, and adheres to any member with a strong adhesive force. It is possible. Further, even if the acid structure is neutralized, the polyurethane particles can be dispersed in water without using a surfactant or even if the amount of the surfactant is small.

Of the acid structure contained in the polyurethane, the proportion of the acid structure to be neutralized is preferably 20% or more, particularly preferably 50% or more. By neutralizing 20% or more of the acid structure, even if the film has a thermal history exposed to high temperatures, the characteristics as an optical material can be maintained or the adhesive strength with any member can be maintained. It is possible to bond them.

Polyurethane preferably contains a polar group in order to enable reaction with a crosslinking agent. Examples of the polar group include a carboxyl group, a carbonyloxycarbonyl group, an epoxy group, a hydroxyl group, an oxy group, an ester group, a silanol group, a silyl group, an amino group, a nitrile group, and a sulfo group. Among these, a hydroxyl group, a carboxyl group, and an amino group are preferable, a hydroxyl group and a carboxyl group are more preferable, and a carboxyl group is particularly preferable. The amount of polar groups in the polyurethane is preferably 0.0001 equivalent / 1 kg or more, more preferably 0.001 equivalent / 1 kg or more, and preferably 1 equivalent / 1 kg or less.

As the polyurethane, a commercially available water-based urethane resin may be used. The water-based urethane resin is a composition containing polyurethane and water, and is usually a composition in which polyurethane and optional components contained as necessary are dispersed in water. As the water-based urethane resin, for example, “ADEKA BONTITER” series manufactured by ADEKA, “Olestar (registered trademark)” series manufactured by Mitsui Chemicals, “Bondic” series manufactured by DIC, “Hydran (WLS201, WLS202) Etc.) series, Bayer's "Imprunil" series, Kao's "Poise" series, Sanyo Kasei's "Samprene" series, Daiichi Kogyo Seiyaku's "Superflex (registered trademark)" Series, “NEOREZ (Neoreds)” series manufactured by Enomoto Kasei Co., Ltd., “Sancure (registered trademark)” series manufactured by Lubrizol can be used. In addition, one type of polyurethane may be used alone, or two or more types may be used in combination at any ratio.

In the urethane composition, the state of the polyurethane is arbitrary, and may be dispersed in the form of particles, or may be dissolved in other components such as a solvent. Among these states, polyurethane is often dispersed in the form of particles. In this case, the average particle diameter of the polyurethane particles is preferably 0.01 μm to 0.4 μm from the viewpoint of the optical properties of the film of the present invention.

[2.2. Crosslinking agent]
The crosslinking agent can crosslink the polyurethane by reacting with a reactive group of the polyurethane to form a bond. This cross-linking can improve the mechanical strength, adhesiveness, and heat and humidity resistance of the slippery layer. Usually, the crosslinking agent is contained in the polyurethane such as the carboxyl group and its anhydride group contained as the acid structure, and the hydroxyl group remaining unreacted after the reaction between the component (i) and the component (ii). It can react with the polar group to form a crosslinked structure.

As the crosslinking agent, for example, a compound having two or more functional groups that can form a bond by reacting with a reactive group of polyurethane can be used. Especially, as a crosslinking agent, the compound which has a functional group which can react with the carboxyl group which a polyurethane has, or its anhydride group is preferable.
Specific examples of the crosslinking agent include epoxy compounds, carbodiimide compounds, oxazoline compounds, and isocyanate compounds. Moreover, a crosslinking agent may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

As the epoxy compound, a polyfunctional epoxy compound having two or more epoxy groups in one molecule can be used. Among them, as the epoxy compound, those that are soluble in water or can be emulsified by being dispersed in water are preferable. If the epoxy group has solubility in water or can be emulsified, when the urethane composition is a water-based resin, the coating property of the water-based resin is improved and the slippery layer is easily produced. It becomes possible. Here, the aqueous resin refers to a composition containing a solid content of a polymer or the like dissolved or dispersed in an aqueous solvent such as water.

Examples of the epoxy compound include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexane glycol, neopentyl glycol and the like glycols 1 Diepoxy compound obtained by etherification of 1 mol with 2 mol of epichlorohydrin; obtained by etherification of 1 mol of polyhydric alcohols such as glycerin, polyglycerin, trimethylolpropane, pentaerythritol, sorbitol and 2 mol or more of epichlorohydrin Polyepoxy compounds: die obtained by esterification of 1 mol of dicarboxylic acid such as phthalic acid, terephthalic acid, oxalic acid, adipic acid and 2 mol of epichlorohydrin Carboxymethyl compound; and the like.

More specific examples of the epoxy compound include 1,4-bis (2 ′, 3′-epoxypropyloxy) butane, 1,3,5-triglycidyl isocyanurate, 1,3-diglycidyl-5- ( (γ-acetoxy-β-oxypropyl) isosinurate, sorbitol polyglycidyl ethers, polyglycerol polyglycidyl ethers, pentaerythritol polyglycidyl ethers, diglycerol polyglycidyl ether, 1,3,5-triglycidyl (2-hydroxy) Ethyl) isocyanurate, glycerol polyglycerol ethers and trimethylolpropane polyglycidyl ethers.
Examples of epoxy compounds are commercially available products such as “Denacol (Denacol EX-521, EX-614B, etc.)” series manufactured by Nagase ChemteX Corporation.
An epoxy compound may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

The amount of the epoxy compound is usually 2 parts by weight or more, preferably 5 parts by weight or more, more preferably 8 parts by weight or more, and usually 40 parts by weight or less, preferably 35 parts by weight or less, with respect to 100 parts by weight of polyurethane. More preferably, it is 30 parts by weight or less. By setting the amount of the epoxy compound to be equal to or more than the lower limit of the above range, the reaction between the epoxy compound and the polyurethane sufficiently proceeds, so that the mechanical strength of the slippery layer can be appropriately improved. Moreover, by making it below an upper limit, the residue of an unreacted epoxy compound can be decreased and the mechanical strength of an easy-slip layer can be improved appropriately.

The amount of the epoxy compound is preferably 0.2 times or more, more preferably 0.4 times or more, particularly preferably 0.6 times, based on the weight, with respect to the amount of the epoxy compound equivalent to the polar group of polyurethane. It is more than double, preferably 5.0 times or less, more preferably 4.0 times or less, and particularly preferably 3.0 times or less. Here, the amount of the epoxy compound equivalent to the polar group of polyurethane means the theoretical amount of the epoxy compound that can react with the total amount of polar group of polyurethane without excess or deficiency. The polar group of the polyurethane can react with the epoxy group of the epoxy compound. Therefore, by keeping the amount of the epoxy compound within the above range, the reaction between the polar group and the epoxy compound can be advanced to an appropriate level, and the mechanical strength of the slippery layer can be effectively improved.

As the carbodiimide compound, a compound having two or more carbodiimide groups in one molecule can be used. This carbodiimide compound is produced using an organic isocyanate such as organic monoisocyanate, organic diisocyanate, or organic triisocyanate as a raw material. Examples of these organic isocyanates include aromatic isocyanates, aliphatic isocyanates, and mixtures thereof. Therefore, as the organic group possessed by the organic isocyanate, either aromatic or aliphatic may be used, or an aromatic organic group and an aliphatic organic group may be used in combination. Among these, from the viewpoint of reactivity, an organic isocyanate having an aliphatic organic group is particularly preferable. Usually, a carbodiimide compound is synthesized by a condensation reaction of an organic diisocyanate.

Specific examples of the organic isocyanate include 4,4′-diphenylmethane diisocyanate, 4,4-diphenyldimethylmethane diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexa Organic diisocyanates such as methylene diisocyanate, cyclohexane diisocyanate, xylylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,3-phenylene diisocyanate; isophorone isocyanate, phenyl isocyanate, cyclohexyl isocyanate, Examples thereof include organic monoisocyanates such as butyl isocyanate and naphthyl isocyanate.

Examples of carbodiimide compounds are commercially available products such as “Carbodilite (Carbodilite V-02, V-02-L2, SV-02, V-04, E-02, etc.)” manufactured by Nisshinbo Chemical Co., Ltd. Is possible.
A carbodiimide compound may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

The amount of the carbodiimide compound is usually 1 part by weight or more, preferably 3 parts by weight or more, and usually 40 parts by weight or less, preferably 30 parts by weight or less based on 100 parts by weight of the polyurethane. By setting the amount of the carbodiimide compound to be equal to or more than the lower limit of the above range, the reaction between the carbodiimide compound and the polyurethane sufficiently proceeds, so that the mechanical strength of the slippery layer can be appropriately improved. Moreover, by making it below an upper limit, the residue of an unreacted carbodiimide compound can be decreased and the mechanical strength of a slippery layer can be improved appropriately.

As the oxazoline compound, a polymer having an oxazoline group represented by the following formula (I) can be used. In the following formula (I), R ⁴ , R ⁵ , R ⁶ and R ⁷ are the same or different and are selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, a phenyl group and a substituted phenyl group. Represents

This oxazoline compound can be produced, for example, by subjecting a monomer component containing an addition-polymerizable oxazoline and optionally containing an unsaturated monomer to solution polymerization in an aqueous medium by a known polymerization method. . Examples of the addition-polymerizable oxazoline include compounds represented by the following formula (II). In the following formula (II), R ⁴ , R ⁵ , R ⁶ and R ⁷ are the same as defined in formula (I). R ⁸ represents an acyclic organic group having an addition polymerizable unsaturated bond.

Specific examples of the addition polymerizable oxazoline are 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2- Examples thereof include oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline and the like. Moreover, these may be used individually by 1 type and may be used combining two or more types by arbitrary ratios. Among these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially.

The amount of the addition-polymerizable oxazoline is preferably 3 parts by weight or more and preferably 100 parts by weight or less with respect to 100 parts by weight of all monomer components used for producing the oxazoline compound. Thereby, when the urethane composition containing an oxazoline compound is cured, curing can be sufficiently advanced, and an easy-sliding layer excellent in durability and water resistance can be obtained.

As an arbitrary unsaturated monomer that can be used in the production of an oxazoline compound, any monomer that can be copolymerized with an addition-polymerizable oxazoline and does not react with an oxazoline group can be used. Such an arbitrary unsaturated monomer can be arbitrarily selected from the monomers described above.

As examples of oxazoline compounds, commercially available products include Epocross WS-500 and WS-700 manufactured by Nippon Shokubai Co., Ltd. Further, for example, for the emulsion type, Epocros K-2010, K-2020 and K-2030 manufactured by Nippon Shokubai Co., Ltd. can be mentioned. Among these, a water-soluble type having high reactivity with polyurethane is preferable.
Moreover, an oxazoline compound may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

The amount of the oxazoline compound can be set so that the molar ratio of the polar group of the polyurethane and the oxazoline group of the oxazoline compound (number of moles of polar group / number of moles of oxazoline group) falls within a predetermined range. Specifically, the molar ratio can be set to 100/20 to 100/100. By making the said molar ratio below the upper limit of the said range, it can prevent that an unreacted polar group remains. Moreover, by making it more than a lower limit, generation | occurrence | production of an excess oxazoline group can be prevented and it can prevent that a hydrophilic group becomes excess.

Furthermore, when the polyurethane has a carboxyl group and the carboxyl group is neutralized, the reaction between the polyurethane and the oxazoline compound makes it difficult for the oxazoline group and the carboxylate to react. Therefore, the reactivity can be controlled by adjusting the kind of nonvolatile base used for neutralization and the degree of nonvolatileity.

As the isocyanate compound, a compound containing two or more isocyanate groups in one molecule can be used. These isocyanate compounds may be aliphatic compounds, alicyclic compounds, or aromatic compounds. Specific examples of the isocyanate compound include the same examples as the component (ii) described as the raw material for polyurethane.

Among the above crosslinking agents, epoxy compounds and carbodiimide compounds are preferable, and epoxy compounds are particularly preferable. When an epoxy compound is used as a crosslinking agent, the adhesiveness of the easy-sliding layer can be particularly greatly improved. Moreover, the pot life of a urethane composition can be improved when a carbodiimide compound is used as a crosslinking agent.

[2.3. Nonvolatile base]
Examples of the non-volatile base include a base that is substantially non-volatile under the treatment conditions when the urethane composition is applied to the base film and then dried. Here, being substantially non-volatile means that a decrease in non-volatile base is usually 80% or less. Moreover, as processing conditions at the time of making it dry after apply | coating a urethane composition to a base film, leaving to stand at 80 degreeC for 1 hour is mentioned, for example. Such a non-volatile base can function as a neutralizing agent that neutralizes the acid structure of the polyurethane.

As the nonvolatile base, an inorganic base or an organic base may be used. Among them, an organic base having a boiling point of 100 ° C. or higher is preferable, an amine compound having a boiling point of 100 ° C. or higher is more preferable, and an amine compound having a boiling point of 200 ° C. or higher is particularly preferable. The organic base may be a low molecular compound or a polymer.

As examples of the non-volatile base, examples of the inorganic base include sodium hydroxide and potassium hydroxide. Examples of the organic base include 2-amino-2-methyl-1-propanol (AMP), triethanolamine, triisopropanolamine (TIPA), monoethanolamine, diethanolamine, and tri [(2-hydroxy) -1 -Propyl] amine, 2-amino-2-methyl-1,3-propanediol (AMPD), 2-amino-2-hydroxymethyl-1,3-propane potassium hydroxide, zinc ammonium complex, copper ammonium complex, silver Ammonium complex, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxydimethoxysilane N-phenyl-γ-aminopropyltri Toxisilane, N, N-bis (trimethylsilyl) urea, 3-ureidopropyltrimethoxysilane, 3-aminopropyl-tris (2-methoxy-ethoxy-ethoxy) silane, N-methyl-3-aminopropyltrimethoxycarboxylic acid Dihydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, quinoline, picoline, pyridine, morpholine, pylene Diamine, N, N-dimethylformamide, ethylenediamine, diethylenetriamine, tetraethylenepentamine, pentaethylenepentamine, monoethanolamine , Diethanolamine, ilopropanolamine, N, N-diethylmethanolamine, N, N-dimethylethanolamine, aminoethylethanolamine, N-methyl-NN-diethanolamine, 1,2-propanediamine, 1,6- Hexamethylenediamine, piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-dicyclohexylmethanediamine, 1,2-cyclohexanediamine, 1, 4-cyclohexanediamine, aminoethylethanolamine, aminopropylethanolamine, aminohexylethanolamine, aminoethylpropanolamine, aminopropylpropanolamine, aminohexylpropano Ruamine, diethylenetriamine, dipropylenetriimidazole, 2-methylimidazole, 1- (2-aminoethyl) -2-methylimidazole, 1- (2-aminoethyl) -2-ethylimidazole, 2-aminoimidazole sulfate, 2- (2-aminoethyl) -benzimidazole, pyrazole, 5-aminopyrazole, 1-methyl-5-aminopyrazole, 1-isopropyl-5-aminopyrazole, 1-benzyl-5-aminopyrazole, 1,3-dimethyl- 5-aminopyrazole, 1-isopropyl-3-methyl-5-aminopyrazole, 1-benzyl-3-methyl-5-aminopyrazole, 1-methyl-4-chloro-5-aminopyrazole, 1-methyl-4- Asino-5-aminopyrazole, 1-isopropyl- -Chloro-5-aminopyrazole, 3-methyl-4-chloro-5-aminopyrazole, 1-benzyl-4-chloro-5-aminopyrazole, amino resin (eg 1,3-dimethyl-4-chloro-melamine) Resin, urea resin, guanamine resin, etc.). Moreover, these may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

The amount of the non-volatile base is usually 0.5 parts by weight or more, preferably 1 part by weight or more, more preferably 2 parts by weight or more, and usually 30 parts by weight or less, preferably 20 parts by weight with respect to 100 parts by weight of polyurethane. Part or less, more preferably 10 parts by weight or less. By setting the amount of the non-volatile base to be equal to or higher than the lower limit of the above range, sufficient adhesive strength can be obtained. Moreover, the color loss of the polarizer made from polyvinyl alcohol can be prevented by making it below an upper limit.

[2.4. Fine particles]
The urethane composition preferably includes fine particles. When the urethane composition contains fine particles, the surface roughness of the easy-sliding layer formed by the cured product of the urethane composition can be increased. Thereby, since the slipperiness of the surface of an easily binding layer can be improved, prevention of blocking of a film and suppression of generation | occurrence | production of a wrinkle at the time of winding a film are attained.

As the fine particles, either inorganic particles or organic particles may be used. However, it is preferable to use water-dispersible particles. Examples of inorganic particles include inorganic oxides such as silica, titania, alumina, zirconia; calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate Etc. Moreover, when the material of an organic particle is mentioned, a silicone resin, a fluororesin, an acrylic resin etc. will be mentioned, for example. Among these, silica is preferable. Silica particles are excellent in ability to suppress the generation of wrinkles and transparency, hardly cause haze, and have no coloration, so that the influence on the optical characteristics of the film of the present invention is small. Silica has good dispersibility and dispersion stability in the urethane composition. Among the silica particles, amorphous colloidal silica particles are particularly preferable. By using two kinds of fine particles, the increase in haze can be minimized and the generation of wrinkles can be more efficiently suppressed.

The average particle diameter of the fine particles is usually 1 nm or more, preferably 5 nm or more, more preferably 10 nm or more, and usually 500 nm or less, preferably 300 nm or less, more preferably 200 nm or less. By making the average particle diameter of the particles equal to or more than the lower limit of the above range, the slipperiness of the slippery layer can be effectively enhanced. Moreover, the haze of a slippery layer can be restrained low by making it below the upper limit of the said range.

The amount of the fine particles is usually 1 part by weight or more, preferably 3 parts by weight or more, more preferably 5 parts by weight or more, and usually 50 parts by weight or less, preferably 40 parts by weight or less, more preferably 100 parts by weight of polyurethane. Is 30 parts by weight or less. By setting the amount of particles to be equal to or higher than the lower limit of the above range, the generation of wrinkles can be suppressed when the film is wound. Moreover, the external appearance without the cloudiness of a film can be maintained by setting it as below an upper limit.

[2.5. Wetting agent]
The urethane composition may contain a wetting agent. By using a wetting agent, the applicability when applying the urethane composition to the base film can be improved, which is preferable.

As the wetting agent, for example, an acetylene surfactant, a fluorine surfactant, or the like can be used. As the acetylene-based surfactant, for example, Surfynol series, Dynol series manufactured by Air Products and Chemicals, Inc. can be used. Moreover, as a fluorine-type surfactant, DIC Corporation mega-fac series, Neos company's tangent series, AGC company's Surflon series, etc. can be used, for example. As the wetting agent, it is preferable to use an acetylene surfactant from the viewpoint of overcoatability.
Moreover, these may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

The blending amount of the wetting agent is usually 0.01% by weight or more, preferably 0.05% by weight or more, more preferably 0.1% by weight or more with respect to the solid content of the urethane composition (coating liquid). Usually, it is 5% by weight or less, preferably 4 parts by weight or less, more preferably 3% by weight or less. Sufficient applicability can be obtained by setting the amount of the wetting agent to be equal to or greater than the lower limit of the above range. Moreover, by making it into the upper limit value or less, bleeding out of the wetting agent can be suppressed, and further, the overcoatability can be improved.

[2.6. solvent]
The urethane composition usually contains a solvent. As the solvent, water or a water-soluble solvent is used. Examples of the water-soluble solvent include methanol, ethanol, isopropyl alcohol, acetone, tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether and the like. Among these, water is preferably used as the solvent. Moreover, a solvent may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

The amount of the solvent can be set so that the viscosity of the urethane composition can be in a range suitable for coating. Usually, the amount of the solvent is set so that the solid content concentration of the urethane composition falls within a desired range. The desired range is preferably 0.5% by weight or more, more preferably 1% by weight or more, preferably 15% by weight or less, more preferably 10% by weight or less. Thereby, the handleability and applicability | paintability of a urethane composition can be made favorable.

[2.7. Arbitrary ingredients]
The urethane composition may contain a curing accelerator in combination with the crosslinking agent. As a hardening accelerator, the well-known hardening accelerator used for formation of a slippery layer can be used. For example, when an epoxy compound is used as a crosslinking agent, the curing accelerator may be a tertiary amine compound (excluding compounds having a 2,2,6,6-tetramethylpiperidyl group having a tertiary amine at the 4-position). ), Boron trifluoride complex compounds and the like are suitable. Moreover, a hardening accelerator may be used individually by 1 type, and may be used combining 2 or more types by arbitrary ratios.
The amount of the curing accelerator is usually 0.001 part by weight or more, preferably 0.01 part by weight or more, more preferably 0.03 part by weight or more, usually 30 parts by weight or less, relative to 100 parts by weight of polyurethane. The amount is preferably 10 parts by weight or less, more preferably 5 parts by weight or less.

The urethane composition may contain a curing aid in combination with the crosslinking agent. As the curing aid, a known curing aid used for forming the easy-sliding layer can be used. Specific examples of curing aids include oxime / nitroso curing aids such as quinonedioxime, benzoquinonedioxime and p-nitrosophenol; maleimide curing aids such as N, Nm-phenylenebismaleimide; diallyl Allyl curing aids such as phthalate, triallyl cyanurate, and triallyl isocyanurate; Methacrylate curing aids such as ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate; Vinyl-types such as vinyltoluene, ethylvinylbenzene, and divinylbenzene Curing aids; and the like. Moreover, a hardening adjuvant may be used individually by 1 type, and may be used combining 2 or more types by arbitrary ratios.
The amount of the curing aid is usually 1 part by weight or more, preferably 10 parts by weight or more, and usually 100 parts by weight or less, preferably 50 parts by weight or less with respect to 100 parts by weight of the crosslinking agent.

Unless the urethane composition significantly impairs the effects of the present invention, for example, a heat stabilizer, a weather stabilizer, a leveling agent, a surfactant, an antioxidant, an antistatic agent, a slip agent, an antiblocking agent, and an antifogging agent. , Lubricants, dyes, pigments, natural oils, synthetic oils, waxes and the like. Moreover, these may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

[2.8. Properties of urethane composition]
The urethane composition is usually a fluid composition. The viscosity of the urethane composition is preferably 15 mPa · s or less, and particularly preferably 10 mPa · s or less. When the viscosity of the urethane composition is within the above range, the urethane composition can be uniformly applied to the surface of the base film. Although there is no special restriction | limiting in the minimum of the viscosity of a urethane composition, Preferably it is 0.25 mPa * s or more. Here, the viscosity is a value measured under a condition of 25 ° C. with a tuning fork type vibration viscometer.
The viscosity of a urethane composition can be adjusted with the ratio of the solvent in a urethane composition, the particle size of particle | grains, etc., for example.

[2.9. Manufacturing method of easy-slip layer]
An easy slip layer is a layer which consists of hardened | cured material of the said urethane composition. This slippery layer is usually provided directly on the base film without any other layer such as an adhesive layer. The slippery layer may be provided only on one side of the base film, or may be provided on both sides. However, it is preferable to provide an easy-sliding layer only on one side of the base film from the viewpoint that a film having an easy-sliding layer can be easily wound into a roll. The easy slip layer can be produced by a production method including a step of forming a film of the urethane composition on the base film and a step of curing the film of the urethane composition.

When forming a film of a urethane composition on a base film, a coating method is usually used. As a coating method, a known coating method can be adopted. Specific coating methods include, for example, a wire bar coating method, a dip method, a spray method, a spin coating method, a roll coating method, a gravure coating method, an air knife coating method, a curtain coating method, a slide coating method, and an extrusion coating method. Etc.

After forming the urethane composition film on the base film, the urethane composition forming the film is cured to obtain an easy-sliding layer as a layer made of a cured product of the urethane composition. Usually, since a urethane composition contains a solvent, when making it harden | cure, a solvent is dried and removed. The drying method is arbitrary, and for example, the drying may be performed by any method such as reduced pressure drying or heat drying. Especially, it is preferable to harden a urethane composition by heat drying from a viewpoint of making reaction, such as a crosslinking reaction, advance rapidly in a urethane composition. When performing heat drying, the crosslinking reaction of polyurethane usually proceeds.

When the resin is cured by heating, the heating temperature is appropriately set within a range in which the solvent can be dried to cure the polymer component in the urethane composition. However, when a stretched film is used as the base film and it is not desired to change the retardation developed in the base film, the heating temperature may be set to a temperature at which no orientation relaxation occurs in the base film. preferable. Specifically, the heating temperature is preferably (Tg−30 ° C.) or higher, more preferably (Tg−10 ° C.) or higher, where Tg is the glass transition temperature of the material forming the base film. Yes, preferably (Tg + 60 ° C.) or less, more preferably (Tg + 50 ° C.) or less.

In addition, it is preferable to improve the adhesion between the base film and the easy-sliding layer by modifying the surface of the base film before forming the urethane composition film on the base film. Examples of the surface modification treatment for the base film include energy ray irradiation treatment and chemical treatment. Examples of the energy ray irradiation treatment include corona discharge treatment, plasma treatment, electron beam irradiation treatment, ultraviolet ray irradiation treatment, etc., and from the viewpoint of treatment efficiency, corona discharge treatment and plasma treatment are preferred, and corona discharge treatment is particularly preferred. preferable. Examples of the chemical treatment include a saponification treatment, a method of immersing in an aqueous oxidizing agent solution such as potassium dichromate solution and concentrated sulfuric acid, and then washing with water.

Furthermore, the surface of the easy-slip layer may be subjected to a hydrophilic surface treatment. Since the surface of the slippery layer usually serves as a bonding surface when the film of the present invention is bonded to an arbitrary member, the surface of the slippery layer is further improved by improving the hydrophilicity of the surface of the slippery layer. It is possible to remarkably improve the adhesion with the member.

Examples of the hydrophilic surface treatment for the easy-sliding layer include corona discharge treatment, plasma treatment, saponification treatment, and ultraviolet irradiation treatment. Among these, from the viewpoint of processing efficiency, corona discharge treatment and plasma treatment are preferable, and corona discharge treatment is more preferable. As the plasma treatment, atmospheric pressure plasma treatment is preferable.

[2.10. Easy-to-slip layer thickness and refractive index]
The thickness of the easy-slip layer is preferably 0.005 μm or more, more preferably 0.01 μm or more, particularly preferably 0.02 μm or more, more preferably 5 μm or less, more preferably 2 μm or less, and particularly preferably 1 μm or less. When the thickness of the slippery layer is within the above range, sufficient adhesive strength between the base film and the slippery layer can be obtained, and defects such as warpage of the film of the present invention can be eliminated.

The ratio _t 2 / _{t 1} with thickness _{t 2} of the thickness _{t 1} and the lubricity layer of the base film is preferably 0.0003 or more, more preferably more than 0.0010, particularly preferably 0.0025 or more, 0.0100 or less is preferable, 0.0080 or less is more preferable, and 0.0050 or less is particularly preferable. Thereby, the transparency of the film of the present invention can be improved. Here, when the film of the present invention comprises only _one base film, the thickness of the base film becomes the thickness t ₁ , and when the film of the present invention comprises two or more base film, those base materials the total thickness of the film is the thickness t _1. Further, the film lubricity layer the lubricity layer thickness The thickness t ₂ next to the case of providing only one layer, lubricating layer thereof if the film is provided with a lubricating layer of two or more layers of the present invention of the present invention the sum of the thickness of a thickness t ₂ of.

The interface refractive index difference between the base film and the easy-slip layer is preferably 0.05 or less. When the interface refractive index difference is within the above range, it is possible to suppress light loss when light is transmitted through the film of the present invention. The interface refractive index difference can ideally be zero.

[3. Other layers]
The film of this invention can be equipped with arbitrary layers on the surface on the opposite side to the slippery layer of a base film. Examples of optional layers include an antireflection layer, a hard coat layer, an antistatic layer, an antiglare layer, an antifouling layer, and a separator film.

[4. Physical properties of film]
The absolute value of the in-plane retardation (hereinafter referred to as “| Re |”) of the film of the present invention is preferably 10 nm or less, more preferably 7 nm or less, still more preferably 5 nm or less, particularly preferably 2 nm or less, and most preferably. Is 1 nm or less, and the lower limit is ideally 0 nm. Since the in-plane retardation Re is so small, the film of the present invention can be suitably used as a protective film for optical elements such as polarizing plates.
The absolute value of the retardation in the thickness direction of the film (hereinafter also referred to as “| Rth |”) is preferably 25 nm or less, more preferably 15 nm or less, still more preferably 5 nm or less, and particularly preferably 2 nm or less. Most preferably, it is 1 nm or less, and the lower limit is ideally 0 nm.
The reason why | Re | and | Rth | of the film of the present invention can be reduced in this way is not clear, but according to the study of the present inventors, it is presumed that the reason is as follows. That is, in the block copolymer, the aromatic vinyl compound hydride has a negative birefringence, and the diene compound hydride has a positive birefringence. It is presumed that the positive and negative phase differences that appear are offset, and the development of the phase difference of the entire film is suppressed.
The in-plane retardation (Re) of the film of the present invention is such that Re = | nx−ny | × d, where the main refractive index in the plane of the film is nx and ny, and the thickness of the layer A is d (nm). Is required. The retardation in the thickness direction (Rth) is defined as follows: Rth = [{, where the in-plane main refractive index of the entire film is nx and ny, the refractive index in the thickness direction is nz, and the thickness of the film is d (nm). (Nx + ny) / 2} −nz] × d. These phase differences Re and Rth can be measured using, for example, a commercially available automatic birefringence meter. The phase differences Re and Rth are evaluated for light having a wavelength of 590 nm.

The film of the present invention preferably has a total light transmittance of 80% or more, more preferably 90% or more, from the viewpoint of stably exhibiting the function as an optical member.

The film of the present invention may have a width-direction dimension of, for example, 1000 mm to 3000 mm. Moreover, although the film of this invention does not have a restriction | limiting in the dimension of the longitudinal direction, since it can suppress blocking property, it is preferable that it is a long film. Here, the “long” film means a film having a length of 5 times or more, preferably 10 times or more, more specifically a roll shape. It has a length enough to be wound up and stored or transported. The upper limit of the ratio of the length to the width is not particularly limited, and can be, for example, 100,000 times or less.

The film of the present invention is excellent in impact resistance. The reason for such excellent impact resistance is not clear, but is presumed to be as follows. That is, in the block copolymer, the aromatic vinyl compound hydride block and the diene compound hydride block are phase-separated, and the phase domain of the diene compound hydride block is between the phase domains of the aromatic vinyl compound hydride block. It is presumed that the structure is connected, and in such a domain structure, the diene compound hydride block functions like a buffer material, so it is presumed that the impact resistance is improved.

The film of the present invention is usually excellent in heat resistance. This is because the block copolymer contained in the base film is excellent in heat resistance, so that the base film containing the block copolymer also has high heat resistance. The specific degree of heat resistance can be set according to the composition ratio of the aromatic vinyl compound hydride block and diene compound hydride block of the block copolymer, the molecular weight, the thickness of the substrate film, etc. Appropriate adjustments may be made accordingly.

[5. Film production method]
The film of this invention can be manufactured with the manufacturing method including the process of preparing a base film, and the process of manufacturing an easy-slip layer on the prepared base film. Here, as described above, the step of producing the easy-sliding layer on the base film includes the step of forming a film of the urethane composition on the base film and the step of curing the film of the urethane composition. Including.

The step of preparing the base film is not particularly limited, and either a melt molding method or a solution casting method can be used. The melt molding method can be further classified into an extrusion molding method, a press molding method, an inflation molding method, an injection molding method, a blow molding method, and a stretch molding method. Among these methods, in order to obtain a film excellent in mechanical strength, surface accuracy, etc., an extrusion molding method, an inflation molding method or a press molding method is preferable. Among them, the efficiency is improved while suppressing the development of retardation more reliably. The extrusion method is particularly preferred from the viewpoint that a film can be produced easily and easily.

When preparing a base film by an extrusion molding method, it is preferable to perform a stretching process after the extrusion molding to obtain a stretched film. The stretching process may be performed before the easy-sliding layer is manufactured, or may be performed after the easy-sliding layer is manufactured. Moreover, when a base film is provided with two or more layers, a stretched film may be obtained by laminating a film layer that has been previously stretched, or a multi-layered film obtained by coextrusion or the like. The film may be stretched to obtain a stretched film.

The stretching method is not particularly limited, and for example, either a uniaxial stretching method or a biaxial stretching method may be employed. As an example of the stretching method, as an example of the uniaxial stretching method, a method of uniaxial stretching in the longitudinal direction using a difference in peripheral speed of a roll for film conveyance; uniaxial stretching in the width direction using a tenter stretching machine And the like. In addition, as an example of the biaxial stretching method, simultaneous biaxial stretching method that stretches in the width direction according to the spread angle of the guide rail at the same time as stretching in the longitudinal direction with an interval between the clips to be fixed; roll for film conveyance Biaxial stretching method such as sequential biaxial stretching method that stretches in the longitudinal direction using the difference in peripheral speed between the two, then grips both ends with clips and stretches in the width direction using a tenter stretching machine, etc. Is mentioned. Furthermore, it is neither parallel nor perpendicular to the width direction of the film using, for example, a tenter stretching machine that can apply a feeding force, a pulling force, or a pulling force at different speeds in the width direction or the longitudinal direction. An oblique stretching method in which oblique stretching is continuously performed in the direction may be used.

Examples of the apparatus used for stretching include a longitudinal uniaxial stretching machine, a tenter stretching machine, a bubble stretching machine, and a roller stretching machine. The stretching temperature is preferably (Tg-30 ° C) or higher, more preferably (Tg-10 ° C) or higher, preferably (Tg + 60 ° C) or lower, where Tg is the glass transition temperature of the resin constituting the film to be stretched. More preferably, it is (Tg + 50 ° C.) or less. The draw ratio can be appropriately selected according to the optical properties of the substrate film to be used. The specific draw ratio is usually 1.05 times or more, preferably 1.1 times or more, and usually 10.0 times or less, preferably 2.0 times or less.

When the film of the present invention includes an optional layer other than the base film and the easy-to-slip layer, an optional layer is provided on the surface of the base film opposite to the easy-to-slip layer at an arbitrary point in the film production method. You may perform a process.
Furthermore, you may perform the process of extending | stretching a base film, a slippery layer, and a film in the arbitrary time points in the manufacturing method of a film.

[6. Application of film]
Since the film of the present invention has a small in-plane retardation Re and excellent impact resistance, it can be used as an optical element and a protective film for the optical element. Examples thereof include members used in display devices such as liquid crystal display devices. Specific examples thereof include a polarizing plate protective film, a retardation film, a brightness enhancement film, a transparent conductive film, a touch panel substrate, a liquid crystal substrate, and light. Examples include a diffusion sheet and a prism sheet. The film of the present invention is particularly suitable for use as a polarizing plate protective film.

When using the film of this invention as a polarizing plate protective film, a polarizing plate is provided with the film of this invention, and a polarizing film. At this time, the film of the present invention is usually provided on both sides of the polarizing film. For example, the film of the present invention is laminated on one side or both sides of a polarizing film via an appropriate adhesive.
Any polarizing film can be used, for example, a polyvinyl alcohol film doped with iodine or the like and then stretched can be used. Moreover, as an adhesive layer, the adhesive etc. which use polymers, such as an acrylic polymer, a silicone type polymer, polyester, a polyurethane, polyether, and a synthetic rubber, as a base polymer are mentioned, for example.

Further, another arbitrary layer may be provided on the polarizing plate. As an arbitrary layer, for example, an antireflection layer, a hard coat layer, a primer layer; an anchor layer; a highly homogenous transparent porous layer (refractive layer) composed of a three-dimensional skeleton of SiOx (x = 1.5 to 2.0) ultrafine particles Rate 1.25 to 1.46); pressure-sensitive adhesive layer; antifouling layer; and the like.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples, and can be implemented with any modifications without departing from the scope of the claims of the present invention and the equivalents thereof.
In the following description, “%” and “part” representing amounts are based on weight unless otherwise specified. Further, the operations described below were performed in a normal temperature and pressure atmosphere unless otherwise specified.

〔Evaluation methods〕
(Impact strength)
The films obtained in Examples and Comparative Examples were fixed horizontally on a jig that can be supported so as to be horizontal. When a steel ball (pachinko ball, weight 5g, diameter 11mm) is dropped from various heights h to the center of the film fixed to the jig, the boundary of the case where the film is not torn and when the film is torn The potential energy (mJ) of the steel ball at height h was defined as impact strength.

(Internal haze)
Using adhesive (“CS9621T” manufactured by Nitto Denko Corporation) on both surfaces of the films obtained in Examples and Comparative Examples, glass (“EagleXG” manufactured by Corning Co., Ltd., thickness 0.7 mm) is bonded to measure. A sample was created. The internal haze of the obtained measurement sample was measured using a turbidimeter (“NDH-2000” manufactured by Nippon Denshoku).

(Re and Rth)
By measuring the films obtained in Examples and Comparative Examples using a phase difference meter (product name: Axoscan, manufactured by AXOMETRICS), an in-plane retardation Re at a wavelength of 590 nm and a thickness direction retardation Rth. Asked.

(Blocking property)
Ten films obtained by cutting the 100 mm square films obtained in Examples and Comparative Examples were stacked. The film was allowed to stand in an oven at 40 ° C. for 24 hours with a 1 kg weight placed on the surface of the 10 stacked films. After standing for 24 hours, the presence or absence of adhesion in the film taken out from the oven was visually observed and evaluated according to the following criteria.
A: Less than 10% of the whole part is in close contact B: More than 10% of the whole part is in close contact

[Production Example 1: Production of base film used in Example 1]
(P1-1. First Stage Polymerization Reaction: Elongation of Aromatic Vinyl Compound Hydride Block A1)
A stainless steel reactor equipped with a stirrer and thoroughly dried and purged with nitrogen was charged with 320 parts of dehydrated cyclohexane, 60 parts of styrene, and 0.38 part of dibutyl ether, and stirred at 60 ° C. to give an n-butyllithium solution. (15 wt% hexane solution) 0.41 part was added to initiate the polymerization reaction, and the first stage polymerization reaction was carried out for 1 hour. At 1 hour after the start of the reaction, a sample was sampled from the reaction mixture and analyzed by gas chromatography (GC). As a result, the polymerization conversion was 99.5%.

(P1-2. Second stage reaction: elongation of diene compound hydride block)
10 parts of isoprene was added to the reaction mixture obtained in the above step (P1-1), and then the second stage polymerization reaction was started to carry out the polymerization reaction for 1 hour. At 1 hour after the start of the second stage polymerization reaction, a sample was sampled from the reaction mixture and analyzed by GC. As a result, the polymerization conversion was 99.5%.

(P1-3. Third stage reaction: elongation of aromatic vinyl compound hydride block A2)
30 parts of styrene was added to the reaction mixture obtained in the step (P1-2), and then the third stage polymerization reaction was started. At 1 hour after the start of the third stage polymerization reaction, a sample was sampled from the reaction mixture, and the weight average molecular weight Mw and number average molecular weight Mn of the polymer were measured. Moreover, as a result of analyzing the sample sampled at this time by GC, the polymerization conversion was almost 100%. Immediately thereafter, 0.2 part of isopropyl alcohol was added to the reaction mixture to stop the reaction. As a result, a mixture containing a polymer having a triblock molecular structure of styrene-isoprene-styrene was obtained.
The obtained polymer was a polymer having a triblock molecular structure with a weight ratio of styrene / isoprene / styrene = 60/10/30. The polymer had a weight average molecular weight (Mw) of about 64000 and a molecular weight distribution (Mw / Mn) of 1.1.

(P1-4. Fourth stage reaction: hydrogenation)
Next, the mixture containing the block copolymer obtained in the above step (P1-3) is transferred to a pressure-resistant reactor equipped with a stirrer, and a diatomaceous earth-supported nickel catalyst (manufactured by JGC Catalysts & Chemicals, Inc.) as a hydrogenation catalyst. E22U ", nickel loading 60%) 8.0 parts and dehydrated cyclohexane 100 parts were added and mixed. The inside of the reactor was replaced with hydrogen gas, and hydrogen was supplied while stirring the solution. A hydrogenation reaction was performed at a temperature of 190 ° C. and a pressure of 4.5 MPa for 6 hours. A block copolymer in which the copolymer was hydrogenated by a hydrogenation reaction was obtained. The weight average molecular weight (Mw) of the block copolymer contained in the obtained reaction solution was about 66000, and the molecular weight distribution (Mw / Mn) was 1.11.
After completion of the hydrogenation reaction, the reaction solution is filtered to remove the hydrogenation catalyst, and then a phenol-based antioxidant pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) Propionate] ("Songnox (registered trademark) 1010" manufactured by Matsubara Sangyo Co., Ltd.) 2.0 parts of xylene solution dissolved in 0.1 parts was added and dissolved.
Next, the above solution is mixed with cyclohexane, xylene and other volatile components as solvents from a solution at a temperature of 260 ° C. and a pressure of 0.001 MPa or less using a cylindrical concentrating dryer (“Contro” manufactured by Hitachi, Ltd.). Removed. The molten polymer was extruded into a strand form from a die, and after cooling, 95 parts of block copolymer pellets were produced by a pelletizer.
The block copolymer contained in the obtained pellets had a weight average molecular weight (Mw) of 65,000, a molecular weight distribution (Mw / Mn) of 1.13, and a hydrogenation rate of almost 100%.
The weight average molecular weight and the number average molecular weight of the polymer (block copolymer and polymer as an intermediate in the production) produced in this production example and the following production examples are standard polystyrene by GPC using THF as an eluent. It measured in 38 degreeC as a conversion value. As a measuring apparatus, HLC8020GPC manufactured by Tosoh Corporation was used.

(P1-5. Production of base film)
The above-described pellets were melt-extruded at an extrusion temperature of 220 ° C. using an extruder (manufactured by Sumitomo Heavy Industries Modern) to obtain a long base film 1 having a thickness of 80 μm.

[Production Example 2: Production of base film used in Example 2]
In the first stage polymerization reaction of (P1-1), the amount of styrene used was changed from 60 parts to 75 parts, and in the second stage polymerization reaction of (P1-2), the amount of isoprene used was changed from 10 parts. In the third stage polymerization reaction of (P1-3), the amount of styrene used was changed from 30 parts to 10 parts, and the film thickness was changed in the same manner as in Production Example 1 A base film 2 having a thickness of 48 μm was obtained.
In Production Example 2, the weight average molecular weight (Mw) of the block copolymer contained in the pellet obtained after the fourth stage hydrogenation reaction is 65000, the molecular weight distribution (Mw / Mn) is 1.25, and the hydrogenation rate is It was almost 100%.

[Production Example 3: Production of base film used in Example 3]
A base film 3 having a thickness of 60 μm was obtained in the same manner as in Production Example 2 except that the thickness of the film was changed.

[Production Example 4: Production of base film used in Example 4]
In the second stage polymerization reaction of (P1-2), the amount of isoprene used was changed from 10 parts to 20 parts, and in the third stage polymerization reaction of (P1-3), the amount of styrene used was changed from 30 parts. The substrate film 4 having a thickness of 40 μm was obtained in the same manner as in Production Example 1 except that the thickness was changed to 20 parts and the thickness of the film was changed.
In Production Example 4, the weight average molecular weight (Mw) of the block copolymer contained in the pellet obtained after the fourth stage hydrogenation reaction is 65000, the molecular weight distribution (Mw / Mn) is 1.24, and the hydrogenation rate is It was almost 100%.

[Production Example 5: Production of base film used in Example 5]
A base film 5 having a thickness of 52 μm was obtained in the same manner as in Production Example 4 except that the thickness of the film was changed.

[Production Example 6: Production of base film of Comparative Example 1]
A base film 6 having a thickness of 60 μm was obtained in the same manner as in Production Example 4 except that the thickness of the film was changed.

[Production Example 7: Production of base film used in Comparative Example 2]
The pellet obtained after the hydrogenation reaction in the fourth stage of Production Example 4 and fine particles [manufactured by Admatechs, silica beads Admafine SO-C2 (particle size 0.5 μm)] are mixed with the block copolymer 99. 5% by weight and 0.5% by weight of fine particles were mixed and melt-kneaded with a twin screw extruder (manufactured by Toyo Seiki Seisakusho) to obtain a polymer composition. The polymer composition was subjected to melt extrusion molding in the same manner as in (P1-5) of Production Example 1 to obtain a long base film 7 having a thickness of 60 μm.

[Production Example 8: Production of base film used in Comparative Example 3]
In the first stage polymerization reaction of (P1-1), the amount of styrene used was changed from 60 parts to 67 parts, and in the second stage polymerization reaction of (P1-2), the amount of isoprene used was changed from 10 parts. The base film 8 having a thickness of 60 μm was obtained in the same manner as in Production Example 1 except that the thickness was changed to 3 parts and the thickness of the film was changed.
In Production Example 8, the weight average molecular weight (Mw) of the block copolymer contained in the pellet obtained after the fourth stage hydrogenation reaction is 65000, the molecular weight distribution (Mw / Mn) is 1.38, and the hydrogenation rate is It was almost 100%.

[Production Example 9: Production of base film used in Comparative Example 4]
In the first stage polymerization reaction of (P1-1), the amount of styrene used was changed from 60 parts to 50 parts, and in the second stage polymerization reaction of (P1-2), the amount of isoprene used was changed from 10 parts. In the third stage polymerization reaction of (P1-3), the amount of styrene was changed from 30 parts to 20 parts, and the thickness of the film was changed. A base film 9 having a thickness of 60 μm was obtained.
In Production Example 9, the weight average molecular weight (Mw) of the block copolymer contained in the pellet obtained after the hydrogenation reaction in the fourth stage is 65000, the molecular weight distribution (Mw / Mn) is 1.33, and the hydrogenation rate is It was almost 100%.

[Preparation Example 1: Preparation of urethane composition 1 for easy slipping layer]
An aqueous dispersion of polyether polyurethane ("Superflex (registered trademark) 130" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., tensile elastic modulus: 1600 N / mm ² ) in an amount of polyurethane of 100 parts and an epoxy compound (Nagase Chem) as a crosslinking agent 15 parts of “Denacol EX313” manufactured by Tex Co., Ltd., 2 parts of adipic acid dihydrazide as a non-volatile base, and an aqueous dispersion of silica particles (“Snowtex MP1040” manufactured by Nissan Chemical Co., Ltd .; average particle diameter of 120 nm) as a lubricant 8 parts by volume of particles and an aqueous dispersion of silica particles (“Snowtex XL” manufactured by Nissan Chemical Co., Ltd .; average particle size 50 nm) and 8 parts by volume of silica particles, and acetylene surfactant (air products) as a wetting agent “Surfinol 440” manufactured by And Chemicals Co., Ltd. To obtain a urethane composition 1 having a solid concentration of 2% liquid.

[Preparation Example 2: Preparation of urethane composition 2 for easy slipping layer]
An aqueous dispersion of polyether-based polyurethane (“Superflex (registered trademark) 870” manufactured by Daiichi Kogyo Seiyaku Co., Ltd., tensile elastic modulus: 1500 N / mm ² ) in an amount of polyurethane of 100 parts and an epoxy compound (Nagase Chem) as a crosslinking agent 20 parts of “Denacol EX521” manufactured by Tex Co., Ltd., 5 parts of adipic acid dihydrazide as a non-volatile base, and an aqueous dispersion of silica particles (“Snowtex MP2040” manufactured by Nissan Chemical Co., Ltd .; average particle size 200 nm) as silica 5 parts by weight of the particles and an aqueous dispersion of silica particles (“Snowtex ZL” manufactured by Nissan Chemical Co., Ltd .; average particle size 80 nm) and 8 parts by weight of the silica particles, and acetylene surfactant (air products) as a wetting agent "Dynol 604" manufactured by And Chemicals Co., Ltd. was blended with 1.0% by weight of the total solid content and water. To obtain a urethane composition 2 having a solid concentration of 2% of the liquid.

[Preparation Example 3: Preparation of urethane composition 3 for easy slipping layer]
An aqueous dispersion of polyether-based polyurethane (“Superflex (registered trademark) 870” manufactured by Daiichi Kogyo Seiyaku Co., Ltd., tensile elastic modulus: 1500 N / mm ² ) in an amount of 100 parts of polyurethane and a carbodiimide compound (Nisshinbo Co., Ltd.) as a crosslinking agent 3 parts of “Carbodilite V-02”, 3 parts of 2-methylimidazole as a non-volatile base, and an aqueous dispersion of silica particles as a lubricant (“Snowtex MP3040” manufactured by Nissan Chemical Co., Ltd .; average particle size 300 nm) 5 parts by weight of silica particles and an aqueous dispersion of silica particles (“Snowtex YL” manufactured by Nissan Chemical Co., Ltd .; average particle diameter 70 nm) and 5 parts by weight of silica particles, and an acetylenic surfactant (air) as a wetting agent "Surfinol 465" manufactured by Products and Chemicals Co., Ltd.) is blended with 0.7% by weight of the total solid content and water. A liquid urethane composition 3 having a solid content concentration of 2% was obtained.

[Example 1]
(1-1: Production of laminated film)
Using a corona treatment device (Kasuga Denki Co., Ltd.), discharge was performed on the surface of the base film 1 obtained in Production Example 1 under the conditions of an output of 300 W, an electrode length of 240 mm, a work electrode distance of 3.0 mm, and a conveyance speed of 4 m / min. Treated.
The urethane composition 1 obtained in Preparation Example 1 was applied to the surface of the base film 1 subjected to the discharge treatment using a roll coater so that the dry thickness was 0.1 μm. Thereafter, heating was performed at a temperature of 130 ° C. for 60 seconds to form an easy-sliding layer on the base film 1. This obtained the 80-micrometer-thick laminated film provided with a base film and a slippery layer.

(1-2: Production of stretched film)
The obtained laminated film was stretched in the film width direction at a stretching temperature of 180 ° C. and a stretching ratio of 2.0 times using a biaxial stretching machine (manufactured by Toyo Seiki Co., Ltd.) to obtain a film having a thickness of 40 μm as an optical film. It was. The obtained film was evaluated by the method described above.

[Example 2]
(1-1) In the same manner as in (1-1) of Example 1, except that the base film 1 was changed to the base film 2 and the urethane composition 1 was changed to the urethane composition 2, A laminated film having a thickness of 48 μm provided with a base film and an easy-slip layer was obtained.
Using a biaxial stretching machine, this laminated film was stretched in the film width direction at a stretching temperature of 160 ° C. and a stretching ratio of 1.2 times to obtain a film having a thickness of 40 μm as an optical film. The obtained film was evaluated by the method described above.

Example 3
(1-1) In the same manner as (1-1) of Example 1 except that the base film 1 was changed to the base film 3 and the urethane composition 1 was changed to the urethane composition 2, A laminated film having a thickness of 60 μm provided with a base film and an easy-slip layer was obtained.
Using a biaxial stretching machine (manufactured by Toyo Seiki Co., Ltd.), this laminated film was stretched in the film width direction at a stretching temperature of 140 ° C. and a stretch ratio of 1.5 times to obtain a film having a thickness of 40 μm as an optical film. The obtained film was evaluated by the method described above.

Example 4
In the same manner as in Example 1, except that the base film 4 was used instead of the base film 1, the urethane composition 3 was used instead of the urethane composition 1, and no stretching was performed. A film having a thickness of 40 μm provided with a film and a slippery layer was obtained. The obtained film was evaluated by the method described above.

Example 5
(1-1) In the same manner as (1-1) in Example 1 except that the base film 1 was changed to the base film 5 and the urethane composition 1 was changed to the urethane composition 3, A laminated film having a thickness of 52 μm and comprising a base film and an easy-slip layer was obtained.
This laminated film was stretched in the film width direction at a stretching temperature of 180 ° C. and a stretching ratio of 1.3 times using a biaxial stretching machine (manufactured by Toyo Seiki Co., Ltd.) to obtain a film having a thickness of 40 μm as an optical film. The obtained film was evaluated by the method described above.

[Comparative Example 1]
Using a biaxial stretching machine (manufactured by Toyo Seiki Co., Ltd.), the base film 6 was stretched in the film width direction at a stretching temperature of 150 ° C. and a stretching ratio of 1.5 times to obtain a film having a thickness of 40 μm. This film comprises only a base film. The obtained film was evaluated by the method described above.

[Comparative Example 2]
Except having changed the base film 6 into the base film 7, it carried out similarly to the comparative example 1, and obtained the film of thickness 40 micrometers provided only with a base film. The obtained film was evaluated by the method described above. The film of Comparative Example 2 contains fine particles.

[Comparative Example 3]
Except having changed the base film 6 into the base film 8, it carried out similarly to the comparative example 1, and obtained the film of thickness 40 micrometers provided only with a base film. The obtained film was evaluated by the method described above.

[Comparative Example 4]
Except having changed the base film 6 into the base film 9, it carried out similarly to the comparative example 1, and obtained the film of thickness 40micrometer provided only with a base film. The obtained film was evaluated by the method described above.

Table 1 shows the results of Examples and Comparative Examples. Table 1 shows the types of base film of the examples and comparative examples (base films 1 to 9) and the weight ratio of the polymer block in the block copolymer contained in the base film (St / Ip / St). And weight ratio (St / Ip ratio) of styrene hydride unit and isoprene hydride unit, weight average molecular weight (Mw), molecular weight distribution (Mw / Mn), type of urethane composition for easy slip layer (urethane composition) 1-3), stretching temperature (° C.), stretching ratio, film thickness before stretching (μm), and film thickness after stretching (μm) are also shown. For example, in the examples and comparative examples, the notation St / Ip / St = 60/10/30 represents styrene in the aromatic vinyl compound hydride block A1, the diene compound hydride block, and the aromatic vinyl compound hydride block A2. The weight ratio of hydride (St) units and isoprene hydride (Ip) units is shown.

The films obtained in Examples 1 to 5 have the characteristics that the impact strength is high, the internal haze is low, and | Re | and | Rth | are both low. Can be usefully used. In addition, since the films obtained in Examples 1 to 5 have a high effect of suppressing the occurrence of blocking, they are suitable for storage and transportation in the form of a long film roll, and are also suitable as protective films having such a shape. Can be used.

Claims

A base film, and an easy-slip layer provided on the base film,
The base film includes a block copolymer,
The block copolymer has a block having an aromatic vinyl compound hydride unit and a block having a diene compound hydride unit;
The sum of the number of blocks having the aromatic vinyl compound hydride unit and the number of blocks having the diene compound hydride is 3 or more per molecule of the block copolymer;
The easy-sliding layer is a film made of a cured product of a composition containing polyurethane, a crosslinking agent capable of crosslinking the polyurethane, a non-volatile base, and fine particles.
In the block copolymer,
The content of the block having the aromatic vinyl compound hydride unit is 80% by weight to 90% by weight, the content of the block having the diene compound hydride unit is 10% by weight to 20% by weight,
The film according to claim 1, wherein at least one end of the polymer chain is composed of a block having the aromatic vinyl compound hydride unit.
The film according to claim 1 or 2, wherein the absolute value of the in-plane retardation is 1 nm or less and the absolute value of the retardation in the thickness direction is 1 nm or less.
The film according to any one of claims 1 to 3, which is a stretched film.
Tensile elastic modulus of the polyurethane is 1000 N / mm 2 or more 5000N / mm 2 or less, the film according to any one of claims 1 to 4.
The film according to any one of claims 1 to 5, wherein the polyurethane is a polyether-based polyurethane.