TW201819192A - Multilayer film - Google Patents

Abstract

The purpose of the present invention is to provide a multilayer film which has low birefringence, excellent ultraviolet light shielding performance, excellent water vapor blocking performance and high surface hardness, while being not susceptible to scratches, and which is suitable as a protective film for polarizing plates. A multilayer film according to the present invention comprises: a layer (e) which contains a resin composition (E) that is obtained by blending 1.0-15.0 parts by weight of an ultraviolet absorbent per 100 parts by weight of a specific block copolymer hydride (D); a resin layer (f) which is laminated on at least one surface of the layer (e) and contains a specific thermoplastic resin (F); and a hard coat layer (h) which is laminated on a surface of at least one resin layer (f), said surface being on the reverse side of the surface that is in contact with the layer (e).

Description

   Multilayer film   

The present invention relates to a multilayer film which is formed by laminating a specific thermoplastic resin layer and a hard coat layer on a layer containing a resin composition, wherein the resin composition is a specific block copolymer hydride Blend UV absorber.

The aromaticity of a block copolymer including a polymer block containing a structural unit derived from an aromatic vinyl compound as a main component and a polymer block containing a structural unit derived from a chain conjugated diene compound has been disclosed. A hydrogenated block copolymer obtained by hydrogenating a ring and a diene-derived double bond has excellent transparency, low birefringence, heat resistance, and low hygroscopicity, etc .; The obtained film is useful as an optical film such as a polarizing film or a retardation film of a liquid crystal display device (Patent Documents 1 to 5).

In a liquid crystal display device, a polarizing film is disposed on both sides of a glass substrate forming a surface of a liquid crystal panel. A normal polarizing film is formed by bonding a polarizing film protective film such as cellulose triacetate on both sides of a polarizer containing a dichroic material such as a polyvinyl alcohol film and iodine.

The above-mentioned polarizer protective film, when irradiated with ultraviolet rays, promotes decomposition and causes a decrease in strength, and at the same time, there is a problem in that transparency is lowered due to discoloration. Therefore, in order to prevent the polarizer from being deteriorated by ultraviolet rays, it is considered necessary that the polarizer protective film has ultraviolet absorbing properties. As a method for imparting ultraviolet absorbing performance to a polarizer protective film, a general method is to add an ultraviolet absorbent to a cellulose triacetate film as a polarizer protective film.

However, the cellulose triacetate has insufficient moisture and heat resistance. When a cellulose triacetate film is used as a polarizer for a polarizer protective film, when used under high temperature or high humidity, it has the same performance as a polarizer. The problem of depression.

On the other hand, Patent Documents 6 and 7 disclose a multilayer film which is composed of an intermediate layer in which a specific block copolymer hydride is blended with an ultraviolet absorber, and an outer layer not containing an ultraviolet absorber. It is small and has excellent ultraviolet shielding performance, impact resistance, and has few surface defects and excellent planarity.

In order to prevent scratches and the like of a film containing a block copolymer hydride during operation, storage, and transportation, Patent Document 6 discloses a multilayer film whose layered layer contains polyester, polycarbonate, polypropylene, and hydrogenated hydrogen. Protective layer of other resins such as olefin polymer and methacrylate polymer. In addition, Patent Document 6 describes that when a multilayer film containing a block copolymer hydride is used for a target optical application, a protective layer containing another resin is peeled off and removed.

Further, Patent Document 6 describes that a hard coat layer can be laminated on a film containing a block copolymer hydride.

However, the optical film obtained by using the film containing a specific block copolymer hydride disclosed in Patent Document 6 has a problem that the surface hardness is low and it is easy to be injured. When the hard coat layer is directly laminated on the film containing the block copolymer hydride, the surface hardness may not be sufficiently improved.

Further, Patent Document 7 describes a multilayer film which is a modified block copolymer hydrogenated product in which an alkoxysilyl group is introduced into a specific block copolymer hydrogenated product, and the laminate is formed by blending a UV absorber in a specific amount. A layer formed by the formed resin composition. In addition, Patent Document 7 also describes that the multilayer film described in this document has excellent ultraviolet absorption performance and mechanical strength, and has few surface defects, and is suitable for an optical film having excellent planarity.

However, the optical film obtained by using the block copolymer hydride disclosed in Patent Document 7 has a problem that the surface hardness of the film is low and the film is easily damaged.

As described above, in order to use a conventionally known film containing a block copolymer hydride as a polarizer protective film on the surface side of a liquid crystal display, it is necessary to increase the surface hardness of the film to prevent injury.

    Prior art literature         Patent literature    

[Patent Document 1] Japanese Patent Laid-Open No. 2002-105151

[Patent Document 2] Japanese Patent Laid-Open No. 2003-114329

[Patent Document 3] Japanese Patent Laid-Open No. 2006-195242

[Patent Document 4] International Publication No. 2009/067290

[Patent Document 5] International Publication No. 2009/137278

[Patent Document 6] Japanese Patent Laid-Open No. 2011-13378

[Patent Document 7] International Publication No. 2015/105127

The present invention has been made in view of such a practical situation, and an object thereof is to provide a multilayer having a small birefringence, excellent ultraviolet shielding performance and water vapor shielding property, high surface hardness, less susceptibility to injury, and suitable for a polarizing plate protective film. membrane.

In order to solve the above-mentioned problems, the present inventors and others have conducted intensive studies and found that a layer containing the resin composition (the resin composition is prepared by blending a predetermined amount of an ultraviolet absorber with a specific block copolymer hydride) (hereinafter In some cases, it is called "layer (e)"), and a layer containing other thermoplastic resins with good surface hardness and transparency (hereinafter referred to as "resin layer (f)") is laminated, and in the resin layer (f) The surface is laminated with a hard coat layer (hereinafter, sometimes referred to as "hard coat layer (h)"), which has a small birefringence, excellent ultraviolet shielding performance and water vapor shielding performance, and is improved. A multilayer film having a surface scratch resistance has completed the present invention.

As described above, according to the present invention, the following multilayer films (1) to (3) can be provided.

(1) A multilayer film comprising: (i) layer (e), which contains 100 parts by weight of the block copolymer hydride (D), and contains 1.0 part by weight or more and 15.0 parts by weight of an ultraviolet absorber. The resin composition (E) formed as follows, wherein the hydrogenated block copolymer (D) contains at least two polymer blocks (A) containing a structural unit derived from an aromatic vinyl compound as a main component, And a block copolymer having at least one polymer block (B) having a structural unit derived from a chain conjugated diene compound as a main component, the total polymer block (A) and the total polymer block ( B) When the weight fraction occupied by the block copolymer (C) is set to wA and wB, the ratio of wA to wB wA: wB is 60:40 to 90:10. Chains and side chains of carbon-carbon unsaturated bonds and aromatic ring carbon-carbon unsaturated bonds of more than 90% of hydrogenation; (ii) resin layer (f), which is laminated on the side of layer (e) Or two-sided thermoplastic resin (F), wherein the thermoplastic resin (F) is selected from the group consisting of polyester, cycloolefin polymer, polystyrene, styrene copolymer, and (meth) acrylate (co) polymer group The above type 1; and (iii) a hard coat layer (h), which is based on at least one laminate (e) adjacent to the surface of the resin layer (f) with the surface opposite layer.

(2) The multilayer film according to (1), wherein the block copolymer (C) has a weight average molecular weight (Mw) of 40,000 or more and 100,000 or less, and has a structure derived from an aromatic vinyl compound The two polymer blocks (A ₁ ) and the polymer block (A ₂ ) as a main component each form both ends of the block copolymer (C), and the weight of the polymer block (A ₁ ) is averaged. molecular weight Mw (a ₁₎ is 20,000 or more, 80,000 or less, the polymer block (a ₂₎ weight average molecular weight Mw of (a ₂₎ of 4,000 or more and 7,000 or less.

(3) The multilayer film according to (1) or (2), in which the scratch hardness specified in JIS K 5600-5-4 of the surface on which the hard coat layer (h) is laminated is H or more.

According to the present invention, it is possible to provide a multilayer film containing a specific block copolymer hydride, which is suitable for an optical film, and has a small birefringence, excellent ultraviolet shielding properties and water vapor shielding properties, and improved surface damage resistance. .

    Forms used to implement the invention    

The multilayer film system of the present invention includes a layer (e) formed using a resin composition (E) containing a predetermined block copolymer hydride (D) and an ultraviolet absorber; and a resin layer (f), which is a system layer It is laminated on at least one side of the layer (e), and contains a predetermined thermoplastic resin (F); and a hard coat layer (h), which is laminated on the opposite side of the at least one resin layer (f) that is in contact with the layer (e) Side face.

Hereinafter, the present invention will be described in detail 1) a block copolymer hydrogenate (D), 2) a resin composition (E), 3) a thermoplastic resin (F), and 4) a multilayer film.

1) Block copolymer hydride (D)

In the multilayer film of the present invention, the hydrogenated block copolymer used to form the layer (e) contains at least two polymers containing a structural unit derived from an aromatic vinyl compound as a main component in a predetermined weight ratio. Segment (A), and a specific block copolymer (C) (hereinafter referred to as "embedded") containing at least one polymer block (B) as a main component of a structural unit derived from a chain conjugated diene compound (In the case of the "block copolymer (C)"), a polymer obtained by hydrogenating the carbon-carbon unsaturated bond in the main chain and the side chain and the carbon-carbon unsaturated bond in the aromatic ring (hereinafter referred to as "block" Copolymer hydride (D) ").

[Polymer Block (A)]

The copolymer block (A) is one having a structural unit derived from an aromatic vinyl compound as a main component. The content of the structural unit derived from the aromatic vinyl compound in the polymer block (A) is usually 90% by weight or more, preferably 95% by weight or more, more preferably 99% by weight or more, and 100% by weight the following. When the content of the structural unit derived from the aromatic vinyl compound in the polymer block (A) is within the above range, it is preferable because the heat resistance of the multilayer film of the present invention is increased.

The polymer block (A) may contain a structural unit other than a structural unit derived from an aromatic vinyl compound. Examples of the structural unit other than the structural unit derived from the aromatic vinyl compound in the polymer block (A) include a structural unit derived from a chain conjugated diene and / or a structure derived from another vinyl compound. unit. The content of structural units other than the structural unit derived from the aromatic vinyl compound in the polymer block (A) is usually 10% by weight or less, preferably 5% by weight or less, and more preferably 1% by weight or less.

The types and contents of the structural units contained in the plurality of polymer blocks (A) may be the same as or different from each other.

The weight average molecular weights of the plurality of polymer blocks (A) may be the same as or different from each other. For example, the weight average molecular weights of the polymer block (A ₁ ) and the polymer block (A ₂ ) forming both ends of the block copolymer (C) may be the same as or different from each other. When the weight average molecular weights of the polymer block (A ₁ ) and the polymer block (A ₂ ) are each Mw (A ₁ ) and Mw (A ₂ ), the weight of the block copolymer (C) is set. When the average molecular weight is in a specific range, one of Mw (A ₁ ) and Mw (A ₂ ) (for example, Mw ( A ₂ )) and increase the other (for example, Mw (A ₁ )) to increase the storage elastic modulus of the viscoelastic properties of the obtained block copolymer hydride (D). This is because it is possible to improve the surface hardness of the multilayer film of the present invention.

From the viewpoint of obtaining the above effects, Mw (A ₁ ) is preferably 20,000 or more and 80,000 or less, more preferably 23,000 or more and 65,000 or less, more preferably 25,000 or more and 55,000 or less, and Mw (A ₂ ) is 4,000. The above is preferably 7,000 or less, more preferably 4,200 or more and 6,000 or less, and more preferably 4,500 or more and 5,500 or less.

[Polymer Block (B)]

The polymer block (B) includes a structural unit derived from a chain conjugated diene compound as a main component. The content of the structural unit derived from the chain conjugated diene compound in the polymer block (B) is usually 90% by weight or more, preferably 95% by weight or more, more preferably 99% by weight or more, and 100 % By weight or less. When the content of the structural unit derived from the chain-like conjugated diene compound in the polymer block B is in the above range, it is preferable because the multilayer film of the present invention has flexibility and has good impact resistance.

Moreover, the polymer block (B) may contain a structural unit other than the structural unit derived from a chain conjugated diene compound. Examples of the component other than the structural unit derived from the chain-like conjugated diene compound in the polymer block (B) include a structural unit derived from an aromatic vinyl compound and / or a structure derived from another vinyl compound. unit. The content of structural units other than the structural unit derived from the chain conjugated diene compound in the polymer block (B) is usually 10% by weight or less, preferably 5% by weight or less, and more preferably 1% by weight or less .

When there are a plurality of polymer blocks (B), the types and contents of the structural units contained in the plurality of polymer blocks (B) may be the same as or different from each other. The weight average molecular weights of the plurality of polymer blocks (B) may be the same as or different from each other.

Here, the structural unit derived from the chain conjugated diene compound in the polymer block (B) (and the structural unit derived from the chain conjugated diene compound arbitrarily contained in the polymer block (A) ), According to the reaction site of the chain conjugated diene compound in the polymerization reaction of the chain conjugated diene compound, may be a structural unit derived from 1,2-addition polymerization, derived from 3,4-addition Any of a structural unit to be polymerized and a structural unit derived from 1,4-addition polymerization.

When the chain conjugated diene compound is subjected to addition polymerization, a repeating unit derived from 1,2-addition polymerization and 3,4-addition polymerization are formed according to the polymerization reaction site of the chain conjugated diene compound. Any one of the repeating units derived from 1,4- and 1,4-addition polymerization. For example, when isoprene is used as the chain conjugated diene compound, a repeating unit represented by (1-methyl-1-vinyl) ethene is formed by 1,2-addition polymerization, and 3 1,4-addition polymerization forms a repeating unit represented by 1-isopropenylethylene, and 1,4-addition polymerization forms a repeating unit represented by 2-methyl-2-butenyl.

1,2-addition polymerization, 3,4-addition polymerization of the repeating unit derived from the chain-like conjugated diene compound in the polymer block (B) (and the polymer block (A)), and The proportion of repeating units formed by 1,4-addition polymerization can be calculated by using the infrared analysis method and the Morello method.

For example, when isoprene is used as the chain conjugated diene compound, the structural unit derived from 1,2-addition polymerization is a structural unit represented by the following formula (1).

The structural unit derived from 3,4-addition polymerization is a structural unit represented by the following formula (2).

[Chemical 2]

The structural unit derived from 1,4-addition polymerization is a structural unit represented by the following formula (3a) or formula (3b).

[Aromatic vinyl compound]

Here, examples of the aromatic vinyl compound used in the formation of the polymer block (A) and the optional formation of the polymer block (B) include styrene; α-methylstyrene, 2 -Methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-tert-butylstyrene, 5-third butyl-2-methylstyrene and other styrenes having an alkyl group as a substituent; 4-monochlorostyrene, dichlorostyrene, 4-monofluorostyrene and the like having a halogen atom as a substituent Styrenes such as 4-methoxystyrene, 3,5-dimethoxystyrene, and the like having alkoxy groups as substituents; 4-phenylstyrenes and the like having aryl groups as substituents Substituents such as styrene. Among these, from the viewpoint of hygroscopicity, those having no polar group are preferred, and from the viewpoint of industrial availability, styrene is particularly preferred.

[Chain conjugated diene compound]

In addition, as the chain conjugated diene-based compound used in the formation of the polymer block (B) and the arbitrary formation of the polymer block (A), it is not necessary from the viewpoint of hygroscopicity. Those with a polar base are preferred. Examples of the chain conjugated diene-based compound having no polar group include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and 1, 3-pentadiene and the like. Among these, in terms of industrial availability, 1,3-butadiene and isoprene are particularly preferred.

(Other vinyl compounds)

In addition, in the formation of the polymer block (A) and / or the polymer block (B), as the aromatic vinyl compound and the chain-shaped conjugated diene compound, the vinyl compound (other Ethylene compounds) include chain olefins, cyclic olefins, chain vinyl compounds, cyclic vinyl compounds, unsaturated cyclic acid anhydrides, and unsaturated fluorinimine compounds. These vinyl compounds may have a nitrile group, an alkoxycarbonyl group, a carboxyl group, or a halogen atom as a substituent. Among these, from the viewpoint of hygroscopicity, those having no polar group are preferred, and chain olefins and cyclic olefins are more preferred. Specific examples of suitable vinyl compounds include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene. Alkenes, 1-dodecene, 1-icosene, 4-methyl-1-pentene, 4,6-dimethyl-1-heptene and other chain olefins; rings such as vinyl cyclohexane As the olefins, chain olefins are more preferred, and ethylene and propylene are particularly preferred.

[Block copolymer (C)]

The number of polymer blocks (A) in the block copolymer (C) is at least two, usually three or less, and preferably two. The number of polymer blocks (B) in the block copolymer (C) is at least one, usually two or less, and preferably one. The block morphology of the block copolymer (C) may be a chain block or a radiation block, because it has excellent mechanical strength, and a chain block is preferred.

Here, the preferred form of the block copolymer (C) is a polymer block (A ₁ ) and a polymer block (A ₂ ) bonded to both ends of the polymer block (B). The block copolymer (A ₁ )-(B)-(A ₂ ), and the polymer block (B ₁ ) and the polymer block (B ₂ ) are bonded at both ends of the polymer block (A ₃ ), Furthermore, at the other end of the polymer block (B ₁ ) and the polymer block (B ₂ ) (that is, the end that is not bonded to the side of the polymer block (A ₃ )), a polymer is bonded to each of them. the block (A ₁₎ and the polymer block (A ₂₎ made of pentablock copolymer _{(A 1) - (B 1} ) - (A 3) - (B 2) - (A 2). Among these, a triblock copolymer is most preferable from the viewpoints of heat resistance, moldability, and mechanical strength.

Let the weight fraction of the total polymer block (A) in the block copolymer (C) be wA (% by weight), and the total polymer block (B) in the block copolymer (C). When the weight fraction is set to wB (% by weight), the ratio of wA to wB wA: wB must be 60: 40 ~ 90: 10, preferably 65: 35 ~ 88: 12, more preferably 70: 30 ~ 85 : 15. When wA is too large, the mechanical strength and flexibility of the block copolymer hydride (D) used in the present invention are reduced, and the multilayer film may be liable to crack. When wA is too small, the surface hardness may be insufficient when the multilayer film is formed.

The molecular weight of the block copolymer (C) is a polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, and is usually 40,000 or more, 100,000 or less, preferably 45,000 or more and 80,000 or less, and more preferably 50,000 or more and 70,000 or less. The molecular weight distribution (Mw / Mn) of the block copolymer (C) is preferably 3 or less, more preferably 2 or less, and particularly preferably 1.5 or less.

When the Mw of the block copolymer (C) is 40,000 or more, the storage elastic modulus of the viscoelastic properties of the obtained block copolymer hydride (D) does not decrease excessively, and it is possible to produce the multilayer film of the present invention. Fully ensure surface hardness. On the other hand, when the Mw of the block copolymer (C) is 100,000 or less, the melt viscosity of the obtained block copolymer hydride (D) does not become excessively high, and it can be suppressed from being caused by heat at the melt molding temperature. Decomposition to produce a low-molecular-weight substance causes the storage elastic modulus of the block copolymer hydride (D) molded article to decrease, and it is possible to sufficiently secure the surface hardness of the multilayer film of the present invention.

As a method for producing the block copolymer (C), a method conventionally known as a method for producing a block copolymer can be adopted. In particular, it is advantageous to use a method such as living anion polymerization in which a monomer having an aromatic vinyl compound as a main component and a monomer having a chain conjugated diene compound as a main component are alternately polymerized. When using this method, it is also easy to control Mw (A ₁ ) and Mw (A ₂ ) to different sizes as required.

[Block copolymer hydride (D)]

The block copolymer hydride (D) is obtained by hydrogenating the carbon-carbon unsaturated bond of the main chain and the side chain of the block copolymer (C) and the carbon-carbon unsaturated bond of the aromatic ring. The hydrogenation rate must be 90% or more, preferably 97% or more, and more preferably 99% or more.

The hydrogenation rate of the carbon-carbon unsaturated bond in the main chain and the side chain of the block copolymer (C) is preferably 97% or more, and more preferably 99% or more. The carbon-carbon unsaturated bond hydrogenation rate of the aromatic ring of the block copolymer (C) is preferably 97% or more, and more preferably 99% or more.

The higher the hydrogenation rate, the better the light resistance and heat resistance of the formed film. The hydrogenation rate of the block copolymer hydride (D) can be determined by ¹ H-NMR measurement.

Here, the method for hydrogenating the unsaturated bond of the block copolymer (C), the reaction form, and the like are not particularly limited, and may be performed in accordance with a conventional method. A hydrogenation method is preferred. Examples of such a hydrogenation method include methods described in International Publication No. 2011/096389, International Publication No. 2012/043708, and the like.

The block copolymer hydride (D) obtained by the method described above can be recovered from the reaction solution after removing the hydrogenation catalyst and / or the polymerization catalyst from the reaction solution containing the block copolymer hydride (D). . The morphology of the recovered block copolymer hydride (D) is not limited, and it is usually formed into a pellet shape to enable subsequent film forming processing.

The molecular weight of the block copolymer hydride (D) is a weight average molecular weight (Mw) in terms of polystyrene measured by GPC using THF as a solvent, and is usually 40,000 or more and 100,000 or less, and 45,000 or more and 80,000 or less as Preferably, it is preferably 50,000 or more and 70,000 or less.

The molecular weight distribution (Mw / Mn) of the block copolymer hydride (D) is preferably 3 or less, more preferably 2 or less, and particularly preferably 1.5 or less. When Mw and Mw / Mn are in the above ranges, the heat resistance and mechanical strength of the film after molding can be maintained.

In addition, the block copolymer hydride (D) used in the present invention can be introduced with an acid anhydride group, for example, by using a method described in International Publication No. 2001/070833 and International Publication No. 2012/043708. A hydrogenated block copolymer (D) of a functional group such as an alkoxysilyl group.

2) Resin composition (E)

The resin composition used in the present invention is prepared in an amount of 1.0 part by weight or more and 15.0 parts by weight or less, preferably 2.0 parts by weight or more and 12.0 parts by weight or less based on 100 parts by weight of the block copolymer hydride (D). It is preferably a composition obtained from an ultraviolet absorber of 3.0 parts by weight or more and 9.0 parts by weight or less (hereinafter, referred to as a "resin composition (E)"). When the blending amount of the ultraviolet absorber is within this range, it is preferable to efficiently isolate ultraviolet rays when forming an optical film, and to maintain transparency in the visible light region without deteriorating hue.

In the multilayer film of the present invention, the layer (e) containing the resin composition (E) has a transmittance at a wavelength of 380 nm of 8% or less, and more preferably 4% or less from the viewpoint of ultraviolet shielding. It is particularly preferred to be less than 1%.

Examples of the ultraviolet absorber used in the present invention include 2,4-dihydroxydiphenyl ketone, 2-hydroxy-4-methoxydiphenyl ketone, and 2-hydroxy-4-methoxydiphenyl ketone. Phenylketone-5-sulfonic acid trihydrate, 2-hydroxy-4-octyloxydiphenylketone, 4-dodecyloxy-2-hydroxydiphenylketone, 4-benzyloxy-2-hydroxy Diphenyl ketones such as diphenyl ketone, 2,2 ', 4,4'-tetrahydroxydiphenyl ketone, 2,2'-dihydroxy-4,4'-dimethoxydiphenyl ketone, etc. Ultraviolet absorber; phenylsalicylate, 4-tert-butyl phenyl 2-hydroxybenzoate, 2-tert-phenyl benzoate, 2,4-di-tert-butyl phenyl-3 Salicylic acid-based ultraviolet absorbers such as 1,5-di-tert-butyl ester, cetyl-3,5-di-tert-butyl ester of 4-hydroxybenzoate; 2- (5-chloro-2H-benzo Triazol-2-yl) -6-tert-butyl-p-cresol, 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl ) Phenol, 2- (2-hydroxy-5-methylphenyl) 2H-benzotriazole, 2- (3-third-butyl-2-hydroxy-5-methylphenyl) -5-chloro- 2H-benzotriazole, 2- (3,5-di-third-butyl-2-hydroxyphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-third Butyl-2-hydroxyphenyl) -2H- Benzotriazole, 2- (3,5-dicumyl-2-hydroxyphenyl) -2H-benzotriazole, 5-chloro-2- (3,5-di-tert-butyl-2 -Hydroxyphenyl) -2H-benzotriazole, 2- (3,5-di-tertiarypentyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (2-hydroxy-5- Third octylphenyl) -2H-benzotriazole, 2- (2-hydroxy-4-octylphenyl) -2H-benzotriazole, 2- (2H-benzotriazol-2-yl ) -4-methyl-6- (3,4,5,6-tetrahydrophthaloylmethyl) phenol, 2,2'-methylenebis [4- (1,1,3,3-tetramethyl Benzyl) -6-[(2H-benzotriazol-2-yl) phenol]] and other benzotriazole-based ultraviolet absorbers; 2- [4,6-bis (2,4-dimethyl (Phenyl) -1,3,5-triazin-2-yl] -5- (octyloxy) phenol, 2,4-bis [2-hydroxy-4-butoxyphenyl] -6- (2 , 4-dibutoxyphenyl) -1,3,5-triazine and other triazine-based ultraviolet absorbers. These may be used individually by 1 type, and may use 2 or more types together. Among these, 2- (3-third-butyl-2-hydroxy-5-methylphenyl) is used for excellent ultraviolet absorption (particularly, ultraviolet absorption near a wavelength of 380 nm). -5-chloro-2H-benzotriazole, 2,2'-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6-[(2H-benzotriazole -2-yl) phenol]], 2- (5-chloro-2H-benzotriazol-2-yl) -6-third butyl-p-cresol, 2- (2H-benzotriazole-2 -Yl) -4- (1,1,3,3-tetramethylbutyl) phenol and the like are preferred.

The said resin composition (E) can mix | blend a formulation other than a ultraviolet absorber. Examples of other formulation agents include light stabilizers, antioxidants, and anti-adhesive agents. These can be prepared individually by 1 type or in combination of 2 or more types.

As the light stabilizer, a hindered amine light stabilizer is preferred. Examples of the hindered amine-based light stabilizer include 3,5-di-third-butyl-4-hydroxyphenyl in a molecular structure, 2,2,6,6-tetramethylpiperidinyl, or 1,2,2,6,6-pentamethyl-4-piperidinyl and other compounds.

Examples of the antioxidant include a phosphorus-based antioxidant, a phenol-based antioxidant, and a sulfur-based antioxidant.

Specific examples of the antioxidant include neopentyl alcohol. [3- (3,5-Di-tertiarybutyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylene glycol [3- (3,5-di-third Butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-third-butyl-4-hydroxyphenyl) propionate, 3,9-bis {2- [3- (3-Third-butyl-4-hydroxy-5-methylphenyl) propanyloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxa Spiro [5,5] undecane, 1,3,5-trimethyl-2,4,6-ginseng (3,5-di-third-butyl-4-hydroxybenzyl) benzene and the like.

When an antioxidant is used, the blending amount is usually 0.01 parts by weight or more and 1 part by weight or less, preferably 0.05 parts by weight or more and 0.9 parts by weight or less based on 100 parts by weight of the block copolymer hydride (D). It is preferably 0.1 part by weight or more and 0.8 part by weight or less. When the amount of the antioxidant is within this range, it is preferable because the resin composition (E) is excellent in heat resistance and stability.

In addition, the blending amount of other blending agents other than the antioxidant is usually 0.01 parts by weight or more and 1 part by weight or less, based on 100 parts by weight of the block copolymer hydride (D), 0.05 parts by weight or more and 0.9 parts by weight. It is preferably not more than 0.1 parts by weight, and more preferably not less than 0.1 parts by weight and not more than 0.8 parts by weight.

Examples of the method for producing the resin composition (E) by blending an ultraviolet absorber with the block copolymer hydride (D) and any other formulations arbitrarily include, for example, the block copolymer hydride (D), After mixing the ultraviolet absorber and any other formulations, the block copolymer hydride (D) is brought into a molten state using a biaxial kneader, a roll mill, a Brabender mixer, an extruder, etc. Method of uniformly mixing.

3) Thermoplastic resin (F)

The thermoplastic resin (hereinafter referred to as a "thermoplastic resin (F)") used in the present invention is used to form a layer or a layer laminated on the side (e) containing the resin composition (E) or Resin layer (f) on both sides to improve the surface hardness of the multilayer film.

The thermoplastic resin (F) is preferably a resin having excellent transparency and high surface hardness. Specific examples of the thermoplastic resin (F) include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; norbornene-based polycyclic Cycloolefin polymers such as ring-opening metathesis polymers of monomers, norbornene and / or norbornene-based polycyclic monomers and addition copolymers of ethylene; polystyrene; styrene. Methacrylate copolymer, styrene. Styrene copolymers such as acrylonitrile copolymers (copolymers of styrene and other monomers); (meth) acrylate (co) polymerization of polymethyl methacrylate, methacrylate (co) polymers, etc. Thing. These may be used individually by 1 type, and may use 2 or more types together.

In the present invention, the "(meth) acrylate (co) polymer" means a homopolymer obtained by using one type of (meth) acrylate and / or using a plurality of types (a Acrylate) copolymer.

In the present invention, the "methacrylate (co) polymer" means a homopolymer obtained by using one type of methacrylate and / or a plurality of types of methacrylate The copolymer obtained.

In addition, in the present invention, "(meth) acrylfluorenyl" means acrylfluorenyl and / or methacrylfluorenyl.

Among these, in addition to improving the surface hardness when molding into a thin film, a cycloolefin polymer and / or a methacrylate (co) polymer is preferred from the viewpoint of low birefringence, and it is moisture-proof In terms of performance, a cycloolefin polymer, polystyrene, and / or a styrene copolymer is preferred. These thermoplastic resins (F) are, for example, resins that can be used commercially.

4) multilayer film

The multilayer film of the present invention is characterized by comprising: a layer (e); a resin layer (f), which is laminated on one or both sides of the layer (e); and a hard coat layer (h), which is laminated on at least The surface of one resin layer (f) that is in contact with the layer (e) is the surface on the opposite side.

[Layer (e)]

The layer (e) is a layer formed using the resin composition (E), and is a layer which is transparent, has low birefringence, has excellent water vapor shielding properties, and has a function of shielding ultraviolet rays.

The thickness of the layer (e) is usually 10 μm or more and 150 μm or less, preferably 15 μm or more and 100 μm or less, and more preferably 20 μm or more and 50 μm or less. When the thickness of the layer (e) is greater than or equal to the lower limit of the aforementioned range, for example, when a protective film as a polarizer is used, the water vapor shielding property is good. In addition, operability for preventing damage to the polarizing film is improved. On the other hand, it is preferable that the thickness of the layer (e) be equal to or less than the upper limit of the aforementioned range because the thickness of the entire polarizing film can be suppressed.

[Resin layer (f)]

The resin layer (f) is a layer containing a thermoplastic resin (F). The content of the thermoplastic resin (F) in the resin layer (f) is usually 95% by weight or more, preferably 97% by weight or more, more preferably 99% by weight or more and 100% by weight or less.

Examples of components other than the thermoplastic resin (F) in the resin layer (f) include a light stabilizer, an antioxidant, and an anti-adhesive agent. As these specific examples, the thing similar to what can be mix | blended with the said resin composition (E) can be mentioned. Moreover, these may be used individually by 1 type, and may use 2 or more types together.

The resin layer (f) is laminated on one or both sides of the layer (e) to improve the mechanical strength and flexibility of the multilayer film, and to achieve the task of improving the surface damage of the multilayer film. In addition, when the multilayer film is melt-extruded, the resin layer (f) is formed so as to be in contact with the casting drum, thereby preventing contamination and adhesion of the casting drum, and being suitable for optics with fewer surface defects and excellent planarity. Multilayer film with thin film.

The thickness of the resin layer (f) is usually 0.5 μm or more and 40 μm or less, preferably 1.0 μm or more and 30 μm or less, and more preferably 1.5 μm or more and 20 μm or less. By setting the thickness of the resin layer (f) to be equal to or more than the lower limit of the aforementioned range, the effect of improving the surface flawability of the multilayer film can be sufficiently exhibited. Moreover, by making the thickness of the resin layer (f) below the upper limit of the aforementioned range, the entire thickness of the multilayer film does not become too thick.

Here, the multilayer film of the present invention may further include an adhesive layer (g) between the layer (e) and the resin layer (f).

As the adhesive layer (g), from the viewpoints of adhesiveness, transparency, low birefringence, and heat resistance, for example, an alkane introduced from the layer (e) that can be used in the multilayer film of the present invention can be suitably used. A layer composed of an oxysilane-based and / or anhydride-based block copolymer hydride (D). When a layer composed of the block copolymer hydride (D) is used as the adhesive layer (g), it is preferable that the layer does not contain an ultraviolet absorber.

When the multilayer film of the present invention has an adhesive layer (g), the thickness of the adhesive layer (g) is usually 0.5 μm or more and 10 μm or less, preferably 1 μm or more and 7 μm or less, and more preferably 1.5 μm or more and 5 μm. the following.

[Hard Coating (h)]

In order to prevent surface damage, the multilayer film of the present invention has a hard coat layer (h) formed on the surface of the resin layer (f) in contact with the layer (e) on the opposite side. By laminating the hard coat layer (h), it is possible to further improve the surface hardness and scratch resistance of the multilayer film.

Here, the hard coat layer (h) can be a hard coat agent (hereinafter, sometimes referred to as a "hard coat agent (H)"). The hard coating agent (H) contains a hard coating material and optionally a filler and other additives.

Examples of the hard coating material include organic hard coating materials such as organic polysiloxane, melamine, epoxy, acrylic, and urethane acrylate, and inorganic hard coatings such as silicon dioxide (SiO ₂ ). material. These may be used individually by 1 type, and may use 2 or more types together. Among these, an acrylic organic hard coating material such as an organic polysiloxane-based organic polysiloxane-based or a polyfunctional acrylate-based acrylic resin is preferred. In addition, since the adhesive force is good and the productivity of the hard coat layer is good, an acrylic hard coat material such as a polyfunctional acrylate is particularly preferred.

Examples of the filler include titanium oxide, zirconia, zinc oxide, tin oxide, cerium oxide, antimony pentoxide (Sb ₂ O ₅ ), tin-doped indium oxide (ITO), and antimony-doped tin oxide (IZO), aluminum-doped zinc oxide (AZO), fluorine-doped tin oxide (FTO). These may be used individually by 1 type, and may use 2 or more types together.

Examples of the other additives include various additives such as a photopolymerization initiator, an antioxidant, an ultraviolet absorber, a light stabilizer, an antistatic agent, a leveling agent, and an antifoaming agent. These may be used individually by 1 type, and may use 2 or more types together.

The content of the filler in the hard coating agent (H) is preferably 100 parts by weight or more and 500 parts by weight or less based on 100 parts by weight of the hard coating material, and more preferably 150 parts by weight or more and 400 parts by weight or less. . The content of the photopolymerization initiator in the hard coating agent (H) is preferably 0.1 parts by weight or more and 10 parts by weight or less based on 100 parts by weight of the hard coating material (especially the organic hard coating material). More preferably, it is 0.5 weight part or more and 5 weight part or less.

The thickness of the hard coat layer (h) is not particularly limited, but it is usually 1 m or more and 10 m or less, preferably 2 m or more and 8 m or less, and more preferably 3 m or more and 6 m or less.

By laminating the resin layer (f) on the surface of the layer (e) and the hard coat layer (h) on the outermost surface of the resin layer (f) in the multilayer film of the present invention, it is possible to conform to JIS K566-5 The scratch hardness (pencil method) measured by the -4 method is improved to H or more, and preferably 2H or more.

[Manufacturing method of multilayer film]

The manufacturing method of the multilayer film of this invention is not specifically limited, The method of manufacturing a multilayer film normally can be applied. For example, first, a film having a layer (e) and a resin layer (f) but not a hard coat layer (h) (hereinafter referred to as a "laminated film (m)") is formed, and then obtained by The surface of the resin layer (f) of the multilayer film (m) that is in contact with the layer (e) is formed on the opposite side to form a hard coat layer (h), and the multilayer film of the present invention can be obtained.

As the molding method applied to the manufacturing method of the laminated film (m), for example, two kinds of three-layer multilayer co-extrusion molding methods can be applied; the three kinds of five-layer multilayer co-extrusion molding methods including the adhesive layer (g) can also be used; The resin composition (E) is melt-extruded on a film (resin layer (f)) containing a thermoplastic resin (F) formed by an extrusion molding method or the like to extrude two or two layers or two or three layers of a laminated film. Lamination method: a method of extruding a lamination method which is a laminated film including three kinds of three layers or three kinds of five layers of an adhesive layer (g).

In any molding method, in order to prevent contamination of the casting drum, it is preferable to perform extrusion molding in such a manner that the resin layer (f) contacts the casting drum and the layer (e) does not directly contact the casting drum.

The molding conditions of the sheet are appropriately selected according to the molding method. For example, when the melt extrusion molding method is used, the resin temperature is usually 180 ° C or higher and 250 ° C or lower, and preferably 190 ° C or higher and 240 ° C or lower. It is appropriately selected in a range of 200 ° C or higher and 230 ° C or lower. When the resin temperature is too low, the fluidity becomes poor, and the smoothness of the surface of the formed multilayer sheet is liable to decrease. Moreover, the sheet extrusion speed cannot be improved, and the industrial productivity tends to be poor. When the resin temperature is too high, the thermal stability of the block copolymer hydride (D) becomes poor, and the mechanical strength of the obtained multilayer film may decrease.

In the present invention, before the resin composition (E) and the thermoplastic resin (F) are melted in an extruder and extruded from an extrusion die installed in the extruder, the molten resin is passed through a gear pump and a filter. Better. By using a gear pump, the uniformity of the resin extrusion amount can be improved and the thickness unevenness can be reduced. Furthermore, by removing foreign matter in the resin by using a filter, a multilayer film suitable for optical applications without defects and having an excellent appearance can be obtained.

Next, a film is formed to form a hard coat layer (h). The method for forming the film to form the hard coat layer (h) is not particularly limited, and a known method can be adopted. For example, a hard coating agent (H) containing an acrylic hard coating material is applied and cross-linked and hardened by ultraviolet rays, electron beams, or the like, or a silicone-based, melamine-based, and / or epoxy-based coating agent is applied. The hard coating material (H) is hard-cured and is thermally cured.

Specific examples of the layer structure of the multilayer film of the present invention include the following, but are not limited thereto.

Hard coat layer (h) / resin layer (f) / layer (e), hard coat layer (h) / resin layer (f) / adhesive layer (g) / layer (e), hard coat layer (h) / Resin layer (f) / layer (e) / resin layer (f), hard coat layer (h) / resin layer (f) / adhesive layer (g) / layer (e) / adhesive layer (g) / resin Layer (f)

The multilayer film of the present invention has a small in-plane retardation (Re) value and a small birefringence. The birefringence of the multilayer film of the present invention is small. For example, the in-plane retardation (Re) value that can be measured by a method described in the examples of the specification of the present application is preferably 3 nm or less, and more preferably 1 nm. Check it out below.

The multilayer film of the present invention has excellent ultraviolet shielding performance. The multilayer film of the present invention has excellent ultraviolet shielding performance. For example, the light transmittance of the multilayer film at a wavelength of 380 nm, which can be measured by using the method described in the examples of the specification of the present application, is preferably 1% or less. It is preferably 0.5% or less, and the light transmittance of the multilayer film having a wavelength of 300 nm is preferably 0.5% or less, and more preferably 0.1% or less for confirmation.

The multilayer film of the present invention has excellent water vapor shielding properties. The multilayer film of the present invention has excellent water vapor blocking properties. For example, the water vapor transmission rate measured by a method described in an example of the specification of the present application is 8 g / m ² . It is preferably below 24h, more preferably 2g / m ² . Please confirm within 24h.

In addition, the multilayer film of the present invention also has excellent surface damage resistance. The multilayer film of the present invention has excellent surface damage resistance. For example, the scratch hardness (pencil method) that can be measured from the method described in the examples of the specification of the present application is preferably H or more, and more preferably 2H or more to confirm.

[Use of the multilayer film of the present invention]

As described above, the multilayer film of the present invention can be suitably used as a polarizing plate protective film because it has excellent ultraviolet shielding performance and surface damage resistance. In addition, the multilayer film of the present invention can be used in applications such as roofing materials, ceiling materials, wall materials, window materials, automobiles, buildings, agricultural greenhouses, and the like, in addition to polarizing plate protective film applications; pharmaceuticals, foods, Application of protective films such as drinking water; use of components such as liquid crystal display devices such as brightness enhancement films, transparent conductive films, substrates for touch panels, liquid crystal substrates, light diffusion sheets, and cymbals; laminated on glass plates, transparent The surface of plastic plates, etc., or the use of ultraviolet shielding materials between multiple glass plates, transparent plastic plates, etc.

    Examples    

The present invention will be described in more detail while the examples are disclosed, but the present invention is not limited to the following examples at all. In addition, "part" and "%" are based on weight as long as they are not notified in advance.

The evaluation in this example was performed using the following method.

    (1) Weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn)    

The molecular weights of the block copolymer and the block copolymer hydride were measured at 38 ° C. using GPC (manufactured by TOSOH Corporation, trade name “HLC8020GPC”) using THF as a washing solution, and using standard polystyrene conversion values.

The weight average molecular weight of the specific polymer block in the block copolymer refers to the weight average molecular weight of the block copolymer as MwX. The weight fraction was set to wY (% by weight), and was calculated according to the following formula. The weight fraction wY (% by weight) of the specific polymer block is calculated from the amount of the monomers used to form the polymer block and the polymerization conversion rate at the end of the polymerization.

Weight average molecular weight of polymer block = MwX × wY / 100

    (2) hydrogenation rate    

The hydrogenation rates (mole%) of the main chain, side chain, and aromatic ring of the block copolymer hydride are calculated by measuring the ¹ H-NMR spectrum of the block copolymer hydride and precursor block copolymer.

    (3) Birefringence of multilayer film    

An automatic birefringence meter ("KOBLA-21ADH" manufactured by Oji Metrology Co., Ltd.) was used, and the in-plane retardation (Re) was measured in the width direction of the multilayer film at intervals of 50 mm and within a range of 200 mm. All the measurement results were averaged and used as the in-plane retardation (Re) value of the multilayer film. The smaller the value of Re, the smaller the birefringence.

    (4) UV shielding performance of multilayer films    

The ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, trade name "V-570") was used to measure the light transmittance of the multilayer film at wavelengths of 380 nm and 300 nm in the ultraviolet region. The smaller the light transmittance, the better the ultraviolet shielding performance.

    (5) Water vapor shielding property of multilayer film    

Using a multilayer film as a test piece, a water vapor transmission tester (manufactured by LYSSY, trade name "L80-5000") was used in accordance with JIS K 7129 (Method A) under conditions of a temperature of 40 ° C and a humidity of 90% RH. The moisture permeability was measured. The smaller the moisture permeability is, the better the water vapor shielding property is.

    (6) Injury resistance of the surface of the multilayer film    

A multilayer film was used as a test piece, and the scratch hardness at a temperature of 23 ° C. (pencil method) was measured in accordance with JIS K 5600-5-4. The evaluation system judged the case where the scratch hardness was 2H or more as good (X), the case where H was more than as allowable (Y), and the case where it was less than H as insufficient (Z).

[Production Example 1] Production of block copolymer hydride (D ₁ )

[Block copolymer (C ₁ )]

In a reactor equipped with a stirring device sufficiently substituted with nitrogen inside, 300 parts of dehydrated cyclohexane, 73.0 parts of dehydrated styrene as an aromatic vinyl compound, and 0.475 parts of n-dibutyl ether were added. 0.75 parts of a 15% cyclohexane solution of n-butyllithium was added to the entire contents while stirring at 60 ° C to start polymerization. After the dropping of the n-butyllithium solution was completed, the entire contents were further stirred at 60 ° C for 60 minutes. The polymerization conversion rate measured by gas chromatography at this point was 99.5%.

Next, 18.0 parts of dehydrated isoprene as a chain conjugated diene compound was added to the reaction solution, and stirring was continued for 30 minutes in this state. The polymerization conversion rate at this point was 99.5%. Subsequently, 9.0 parts of dehydrated styrene as an aromatic vinyl compound was further added and stirred for 60 minutes. The polymerization conversion at this point was about 100%. Here, 0.5 part of isopropyl alcohol was added to the reaction mixture to stop the reaction. The obtained polymer solution contained a polymer block (A ₁ ) composed of a structural unit derived from styrene and a polymer composed of a structural unit derived from isoprene in the following order. The weight average molecular weight (Mw) of the block (B) and the block copolymer (C ₁ ) composed of the polymer block (A ₂ ) composed of a structural unit derived from styrene was 57,300, and the molecular weight distribution (Mw / Mn) was 1.03, wA ₁ : wB: wA ₂ = 73: 18: 9. Further, polymer block (A ₁₎ weight average molecular weight Mw (A ₁₎ was 41,600, the polymer block (A ₂₎ weight average molecular weight Mw of (A ₂₎ was 5,200.

[Block copolymer hydride (D ₁ )]

Next, the polymer solution was transferred to a pressure-resistant reactor equipped with a stirring device, and a diatomite-supported nickel catalyst (produced by Nippon Kasei Kasei Kasei Co., Ltd., trade name "E22U", nickel loading amount 60) was added as a hydrogenation catalyst. %) 8.0 parts and dehydrated cyclohexane 100 parts and mixed. The pressure-resistant reactor was replaced with hydrogen, and hydrogen was supplied while stirring the solution, and a hydrogenation reaction was performed at a temperature of 190 ° C and a pressure of 4.5 MPa for 6 hours. The weight average molecular weight (Mw) of the hydrogenated block copolymer (D ₁ ) after the hydrogenation reaction was 60,700, and the molecular weight distribution (Mw / Mn) was 1.04.

After the hydrogenation reaction is completed, the reaction solution is filtered to remove the hydrogenation catalyst, and neopentyl alcohol in which a phenolic antioxidant is dissolved is added. 1.0 part of xylene solution prepared from 0.1 part of [3- (3,5-di-third-butyl-4-hydroxyphenyl) propionate] (manufactured by KOYO Chemical Research Institute, trade name "Songnox1010") And dissolve the polymer after the hydrogenation reaction.

Next, the above solution after adding the xylene solution was concentrated and dried under the conditions of a temperature of 260 ° C. and a pressure of 0.001 MPa or less using a cylindrical concentration dryer (manufactured by Hitachi, Ltd., trade name “KONTRO”), The solvent such as cyclohexane and xylene, and other volatile components were removed from the solution. This concentration operation was continuously performed, and the obtained molten polymer was passed through a polymer filtration device (manufactured by Fuji Film Co., Ltd.) equipped with a sintered filter made of stainless steel having a pore size of 5 μm, which was connected to the above-mentioned cylindrical concentration dryer, at a temperature of 260. Filter at ℃. After filtration, the molten polymer was extruded from the mold into strands. After extrusion, 95 parts of pellets of the block copolymer hydride (D ₁ ) were produced by cooling and using a granulator.

The weight average molecular weight (Mw) of the obtained pelletized block copolymer hydrogenated product (D ₁ ) was 60,100, the molecular weight distribution (Mw / Mn) was 1.10, and the hydrogenation rate was approximately 100% (99% or more).

[Production Example 2] Production of block copolymer hydride (D ₂ )

[Block copolymer (C ₂ )]

Polymerization was carried out in the same manner as in Production Example 1 except that dehydrated styrene and dehydrated isoprene were divided into three times, and 66.0 parts of dehydrated styrene, 25.0 parts of dehydrated isoprene, and 9.0 parts of dehydrated styrene were added in the following order. Reaction, and stop the reaction. The obtained polymer solution contained a polymer having a polymer block (A ₁ ) composed of a structural unit derived from styrene and a polymer composed of a structural unit derived from isoprene in the following order. The weight average molecular weight (Mw) of the block (B) and the block copolymer (C ₂ ) composed of the polymer block (A ₂ ) composed of a structural unit derived from styrene was 56,200, and the molecular weight distribution (Mw / Mn) was 1.02, wA ₁ : wB: wA ₂ = 66: 25: 9. Further, polymer block (A ₁₎ weight average molecular weight Mw (A ₁₎ was 36,900, the polymer block (A ₂₎ weight average molecular weight Mw of (A ₂₎ of 5,100.

[Block copolymer hydride (D ₂ )]

Next, the polymer solution was subjected to a hydrogenation reaction in the same manner as in Production Example 1. The weight average molecular weight (Mw) of the hydrogenated block copolymer (D ₂ ) after the hydrogenation reaction was 59,500, and the molecular weight distribution (Mw / Mn) was 1.03.

After the completion of the hydrogenation reaction, after adding a phenolic antioxidant in the same manner as in Production Example 1, it was concentrated and dried to produce 94 parts of pellets of a block copolymer hydrogenated product (D ₂ ). The weight average molecular weight (Mw) of the obtained pelletized block copolymer hydrogenated product (D ₂ ) was 58,900, the molecular weight distribution (Mw / Mn) was 1.08, and the hydrogenation rate was about 100% (99% or more).

[Production Example 3] Production of Block Copolymer Hydrogenate (D ₃ )

[Block copolymer (C ₃ )]

Polymerization was carried out in the same manner as in Production Example 1 except that dehydrated styrene and dehydrated isoprene were divided into three times, and 57.0 parts of dehydrated styrene, 18.0 parts of dehydrated isoprene, and 25.0 parts of dehydrated styrene were added in the following order. Reaction, and stop the reaction. The obtained polymer solution contained a polymer having a polymer block (A ₁ ) composed of a structural unit derived from styrene and a polymer composed of a structural unit derived from isoprene in the following order. The weight average molecular weight (Mw) of the block (B) and the block copolymer (C ₃ ) composed of the polymer block (A ₂ ) composed of a structural unit derived from styrene is 56,200, and the molecular weight distribution (Mw / Mn) was 1.02, wA ₁ : wB: wA ₂ = 57: 18: 25. Further, polymer block (A ₁₎ weight average molecular weight Mw (A ₁₎ was 31,900, the polymer block (A ₂₎ weight average molecular weight Mw of (A ₂₎ was 14,100.

[Block copolymer hydride (D ₃ )]

Next, the polymer solution was subjected to a hydrogenation reaction in the same manner as in Production Example 1. The weight average molecular weight (Mw) of the hydrogenated block copolymer (D ₃ ) after the hydrogenation reaction was 60,300, and the molecular weight distribution (Mw / Mn) was 1.04.

After the completion of the hydrogenation reaction, after adding a phenolic antioxidant in the same manner as in Production Example 1, it was concentrated and dried to produce 95 parts of pellets of a block copolymer hydrogenated product (D ₃ ). The weight average molecular weight (Mw) of the obtained pelletized block copolymer hydrogenated product (D ₃ ) was 59,000, the molecular weight distribution (Mw / Mn) was 1.06, and the hydrogenation rate was approximately 100% (99% or more).

[Production Example 4] Production of block copolymer hydride (D ₄ )

[Block copolymer (C ₄ )]

Polymerization was performed in the same manner as in Production Example 1 except that the dehydrated styrene and dehydrated isoprene were divided into three times, and 41.0 parts of dehydrated styrene, 18.0 parts of dehydrated isoprene, and 41.0 parts of dehydrated styrene were added in the following order. Reaction, and stop the reaction. The obtained polymer solution contained a polymer having a polymer block (A ₁ ) composed of a structural unit derived from styrene and a polymer composed of a structural unit derived from isoprene in the following order. The weight average molecular weight (Mw) of the block (B) and the block copolymer (C ₄ ) composed of the polymer block (A ₂ ) composed of a structural unit derived from styrene was 56,700, and the molecular weight distribution (Mw / Mn) was 1.02, wA ₁ : wB: wA ₂ = 41: 18: 41. Further, polymer block (A ₁₎ weight average molecular weight Mw (A ₁₎ was 23,100, the polymer block (A ₂₎ weight average molecular weight Mw of (A ₂₎ was 23,300.

[Block copolymer hydride (D ₄ )]

Next, the polymer solution was subjected to a hydrogenation reaction in the same manner as in Production Example 1. The weight average molecular weight (Mw) of the hydrogenated block copolymer (D ₄ ) after the hydrogenation reaction was 60,100, and the molecular weight distribution (Mw / Mn) was 1.07.

After the completion of the hydrogenation reaction, a phenol-based antioxidant was added in the same manner as in Production Example 1, and then concentrated and dried to produce 93 parts of pellets of a block copolymer hydrogenate (D ₄ ). The weight average molecular weight (Mw) of the obtained pelletized block copolymer hydrogenated product (D ₄ ) was 59,500, the molecular weight distribution (Mw / Mn) was 1.07, and the hydrogenation rate was approximately 100% (99% or more).

[Production Example 5] Production of Hard Coating Agent (H ₁ )

Sb ₂ O ₅ particles (catalyzed into a catalyst) 250 parts by industrial company, number average particle size 30nm), 3 parts by light diffusion agent (inorganic hard coating material) SiO2 particles (manufactured by CI Kasei Co., Ltd., number average particle size 300nm), and photopolymerization initiator (CIBA.SPECIALTY ．2 parts manufactured by CHEMICALS, trade name "IRGACURE (registered trademark) 184"), and methacrylfluorene-modified dimethyl polysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "X-22-164A ”) 1 part, and a hard coating agent (H ₁ ) was produced by stirring at 2000 rpm for 5 minutes using a stirrer.

[Production Example 6] Production of Resin Composition (E ₁ )

100 parts of the hydrogenated block copolymer (D ₁ ) produced in Production Example 1 was added with (2- (5-chloro-2H-benzotriazol-2-yl) -6-tert-butyl) as an ultraviolet absorber. 6.0 parts of base-p-cresol (UVA ₁ ) (manufactured by Sumitomo Chemical Co., Ltd., trade name "SUMlSORB (registered trademark) 300") and uniformly mixed. The obtained mixture was extruded at a resin temperature of 210 ° C using a biaxial extruder out. after cooling the extrudate, followed by cutting pelletizer manufactured by the resin composition (E ₁₎ 97 parts of the pellets. the resin composition for producing (E ₁₎ summary of the detail shown in table 1.

[Production Examples 7 to 10] Production of Resin Compositions (E ₂ ) to (E ₅ )

Except that the block copolymer hydrides (D ₁ ) to (D ₄ ) produced in Production Examples 1 to 4 were used, 100 parts of the block copolymer hydride (D) was used. 5-chloro-2H-benzotriazol-2-yl) -6. Tert-butyl-p-cresol (UVA ₁ ) and / or 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol (UVA ₂ ) (manufactured by Sumitomo Chemical Co., Ltd. under the trade name "SUMISORB (registered trademark) 340") was added in addition to the amount described in Table 1, and is related to manufacturing Example 6 was performed in the same manner to produce pellets of the resin compositions (E ₂ ) to (E ₅ ). A summary of the manufactured resin compositions (E ₂ ) to (E ₅ ) is shown in Table 1.

(Example 1) Multilayer film (m ₁ h ₁ )

[Manufacture of laminated film (m ₁ )]

Pellets using a resin composition (E ₁ ), and a ring-opening metathesis polymer hydrogenated polymer (F ₁ ) as a thermoplastic resin (manufactured by Japan Zeon Corporation, trade name "ZEONEX (registered trademark) 690R", glass transition temperature) 136 deg.] C) of the pellets produced resin composition is formed comprising (E ₁₎ of the intermediate layer layer (e _1), for the complex containing the ring-opening (F ₁₎ of the resin layer (f ₁₎ for the decomposition of the polymer hydrogenated polymer skin Two kinds of three-layer laminated film (m ₁ ).

Specifically, the laminated film (m ₁ ) is manufactured by using a T-die type two-layer three-layer film forming machine (T-die width 300 mm) using a uniaxial extruder 2 machine with a screw having a diameter of 20 mm and a mirror surface. Thin film pulling machine for casting drum. The manufacturing conditions of the laminated film are set to a resin temperature of 220 ° C for the resin composition (E ₁ ), a resin temperature of 250 ° C for the ring-opening metathesis polymer hydrogenated polymer (F ₁ ), a T-die temperature of 250 ° C, and a casting drum temperature 80 ° C.

The manufactured multilayer film (m ₁ ) has a three-layer structure of (f ₁ ) / (e ₁ ) / (f ₁ ), with a width of 230 mm and a total thickness of 40 μm (thickness of each layer: 10 μm / 20 μm / 10 μm).

[Manufacture of a multilayer film (m ₁ h ₁ ) with a hard coating layer (h ₁ )]

The hard coating agent (H ₁ ) obtained in Production Example 5 was applied to one surface of the obtained laminated film (m ₁ ) using a rod coater. After the application, an ultraviolet ray was used to irradiate ultraviolet rays in a range of wavelengths of 300 to 390 nm so that the cumulative light amount became 200 mJ / cm ² . The hard coating agent (H ₁ ) is hardened by this ultraviolet irradiation to form a hard coating layer (h ₁ ) having a thickness of 3 μm, thereby manufacturing a multilayer film (m ₁ h ₁ ) in which a hard coating layer (h) is laminated on one surface.

The manufactured multilayer film (m ₁ h ₁ ) has a 4-layer structure of (f ₁ ) / (e ₁ ) / (f ₁ ) / (h ₁ ), with a width of 230 mm and a total thickness of 43 μm (thickness of each layer: 10 μm / 20 μm / 10 μm / 3 μm).

Using the produced multilayer film (m ₁ h ₁ ), the in-plane retardation (Re) of the film, light transmittance in the ultraviolet region, moisture permeability, and surface scratch hardness were measured.

As a result, the in-plane retardation (Re) was 0.9 nm, the light transmittance was 2.3% at 380 nm, 0.0% at 300 nm, and the water vapor transmission rate was 1.6 g / m ² . 24h. Re (birefringence), light transmittance (ultraviolet shielding performance), and water vapor transmission (water vapor shielding) are all sufficiently small values. The surface scratch hardness was 2H and evaluated as good (X). The evaluation results are summarized and described in Table 2.

(Example 2) Multilayer film (m ₂ h ₁ )

[Manufacture of laminated film (m ₂ )]

A layer (e ₂ ) containing a resin composition (E ₂ ) was produced as an intermediate layer in the same manner as in Example 1 except that pellets of the resin composition (E ₂ ) were used instead of the resin composition (E ₁ ). The resin layer (f ₁ ) containing the ring-opening metathesis polymer hydrogenated polymer (F ₁ ) is a two-layer, three-layer laminated film (m ₂ ) of a surface layer.

The produced multilayer film (m ₂ ) had a three-layer structure of (f ₁ ) / (e ₂ ) / (f ₁ ), with a width of 230 mm and a total thickness of 40 μm (thickness of each layer: 10 μm / 20 μm / 10 μm).

[Manufacturing of multilayer film (m ₂ h ₁ ) with hard coat layer (h ₁ )]

Except for using the laminated film (m ₂₎ instead of the laminated film (m ₁₎ except that system as in Example 1 in the same manner produced a multilayer film (m ₂ h ₁₎ one surface layer laminated on the hard coat layer (H ₁₎ of.

The manufactured multilayer film (m ₂ h ₁ ) has a 4-layer structure of (f ₁ ) / (e ₂ ) / (f ₁ ) / (h ₁ ), with a width of 230 mm and a total thickness of 43 μm (thickness of each layer: 10 μm / 20μm / 10μm / 3μm).

The produced multilayer film (m ₂ h ₁ ) was used to evaluate birefringence, ultraviolet shielding performance, water vapor shielding performance, and surface scratch resistance. The evaluation results are summarized and described in Table 2.

(Example 3) Multilayer film (m ₃ h ₁ )

[Manufacture of laminated film (m ₃ )]

Except that polystyrene (F ₂ ) (manufactured by PS Japan, "PSJ-POLYSTYRENE (registered trademark) HF77") was used instead of the ring-opening metathesis polymer hydrogenated polymer (F ₁ ) as the thermoplastic resin, it was the same as Example 1 same manner as two kinds of three-layer laminated film of the surface layer (formed is manufactured (E ₁₎ of the layer (e ₁₎ an intermediate layer comprising a resin composition, comprising polystyrene (F ₂₎ of the resin layer (f ₂₎ is m ₃ ).

The produced multilayer film (m ₃ ) has a three-layer structure of (f ₂ ) / (e ₁ ) / (f ₂ ), with a width of 230 mm and a total thickness of 40 μm (thickness of each layer: 10 μm / 20 μm / 10 μm).

[Manufacturing of a multilayer film (m ₃ h ₁ ) with a hard coating layer (h ₁ )]

Except for using the laminated film (m ₃₎ instead of the laminated film (m ₁₎ except that system and the embodiment same manner as Example 1 is manufactured in a multilayer film on one side laminated with a hard coat layer (H ₁₎ of the (m ₃ h _1). The manufactured multilayer film (m ₃ h ₁ ) has a 4-layer structure of (f ₂ ) / (e ₁ ) / (f ₂ ) / (h ₁ ), with a width of 230 mm and a total thickness of 43 μm (thickness of each layer: 10 μm / 20μm / 10μm / 3μm). The produced multilayer film (m ₃ h ₁ ) was used to evaluate birefringence, ultraviolet shielding performance, water vapor shielding performance, and surface scratch resistance. The evaluation results are summarized and described in Table 2.

(Example 4) Multilayer film (m ₄ h ₁ )

[Manufacture of laminated film (m ₄ )]

Except that the resin composition (E ₃ ) was used instead of the resin composition (E ₁ ), a layer (e ₃ ) containing the resin composition (E ₃ ) was formed as an intermediate layer and produced in the same manner as in Example 1. The resin layer (f ₁ ) of the cyclic metathesis polymer hydrogenated polymer (F ₁ ) is a two-layer, three-layer laminated film (m ₄ ) of a surface layer.

The manufactured multilayer film (m ₄ ) had a three-layer structure of (f ₁ ) / (e ₃ ) / (f ₁ ), with a width of 230 mm and a total thickness of 40 μm (thickness of each layer: 10 μm / 20 μm / 10 μm).

[Manufacture of a multilayer film (m ₄ h ₁ ) with a hard coating layer (h ₁ )]

(M ₄₎ instead of the laminated film (m ₁₎ except for using the laminated film other than Department in Example 1 was carried out to manufacture the multilayer film (m ₄ h ₁₎ one surface layer laminated on the hard coat layer (H ₁₎ of. The manufactured multilayer film (m ₄ h ₁ ) has a 4-layer structure of (f ₁ ) / (e ₃ ) / (f ₁ ) / (h ₁ ), with a width of 230 mm and a total thickness of 43 μm (thickness of each layer: 10 μm / 20μm / 10μm / 3μm). The produced multilayer film (m ₃ h ₁ ) was used to evaluate birefringence, ultraviolet shielding performance, water vapor shielding performance, and surface scratch resistance. The evaluation results are summarized and described in Table 2.

(Example 5) Multilayer film (m ₅ h ₁ )

[Manufacture of laminated film (m ₅ )]

Except that the resin composition (E ₄ ) was used instead of the resin composition (E ₁ ), a layer (e ₄ ) containing the resin composition (E ₄ ) was formed as an intermediate layer and manufactured to form a layer containing the resin composition (E ₄ ) in the same manner as in Example 1. The resin layer (f ₁ ) of the cyclic metathesis polymer hydrogenated polymer (F ₁ ) is a two-layer, three-layer laminated film (m ₅ ) of a surface layer.

The manufactured multilayer film (m ₅ ) had a three-layer structure of (f ₁ ) / (e ₄ ) / (f ₁ ), with a width of 230 mm and a total thickness of 40 μm (thickness of each layer: 10 μm / 20 μm / 10 μm).

[Manufacture of a multilayer film (m ₅ h ₁ ) with a hard coating layer (h ₁ )]

Except for using the laminated film (m ₅₎ laminated film (m ₁₎ was used instead of, based in Example 1 was carried out to manufacture a multilayer film on one side laminated with a hard coat layer (H ₁₎ of the (m ₅ h _1). The manufactured multilayer film (m ₅ h ₁ ) has a 4-layer structure of (f ₁ ) / (e ₄ ) / (f ₁ ) / (h ₁ ), with a width of 230 mm and a total thickness of 43 μm (thickness of each layer: 10 μm / 20μm / 10μm / 3μm).

The produced multilayer film (m ₅ h ₁ ) was used to evaluate birefringence, ultraviolet shielding performance, water vapor shielding performance, and surface scratch resistance. The evaluation results are summarized and described in Table 2.

(Example 6) Multilayer film (m ₆ h ₁ )

[Manufacture of laminated film (m ₆ )]

Except that the resin composition (E ₅ ) was used instead of the resin composition (E ₁ ), a layer (e ₅ ) containing the resin composition (E ₅ ) was formed as an intermediate layer and manufactured to form a layer containing the resin composition (E ₅ ) in the same manner as in Example 1. The resin layer (f ₁ ) of the cyclic metathesis polymer hydrogenated polymer (F ₁ ) is a two-layer, three-layer laminated film (m ₆ ) of a surface layer.

The produced multilayer film (m ₆ ) had a three-layer structure of (f ₁ ) / (e ₅ ) / (f ₁ ), with a width of 230 mm and a total thickness of 40 μm (thickness of each layer: 10 μm / 20 μm / 10 μm).

[Manufacture of a multilayer film (m ₆ h ₁ ) with a hard coating layer (h ₁ )]

Except for using the laminated film (m ₆₎ instead of the laminated film (m ₁₎ except that system as in Example 1 in the same manner and manufactured in a multilayer film on one side laminated with a hard coat layer (H ₁₎ of the (m ₆ h _1). The manufactured multilayer film (m ₆ h ₁ ) has a 4-layer structure of (f ₁ ) / (e ₅ ) / (f ₁ ) / (h ₁ ), with a width of 230 mm and a total thickness of 43 μm (thickness of each layer: 10 μm / 20μm / 10μm / 3μm).

The manufactured multilayer film (m ₆ h ₁ ) was used to evaluate birefringence, ultraviolet shielding performance, water vapor shielding performance, and surface scratch resistance. The evaluation results are summarized and described in Table 2.

(Comparative Example 1) Laminated film (m ₁ )

The two types of three-layer laminated film (m ₁ ) produced in Example 1 with no laminated hard coat layer (h) were used to evaluate birefringence, ultraviolet shielding performance, water vapor shielding performance, and surface damage resistance. The evaluation results are summarized and described in Table 2.

(Comparative Example 2) Laminated film (m ₇ )

[Manufacture of laminated film (m ₇ )]

A resin-containing composition was produced in the same manner as in Example 1 except that the hydrogenated block copolymer (D ₁ ) of Production Example 1 was used instead of the ring-opening metathesis polymer hydrogenated polymer (F ₁ ) as the thermoplastic resin. (E ₁₎ of the layer (e ₁₎ an intermediate layer, comprising the hydrogenated block copolymer (D ₁₎ of the resin layer (d ₁₎ of two kinds of three-layer laminated film of the surface layer (m _7).

The produced multilayer film (m ₇ ) has a three-layer structure of (d ₁ ) / (e ₁ ) / (d ₁ ), with a width of 230 mm and a total thickness of 40 μm (thickness of each layer: 10 μm / 20 μm / 10 μm). The laminated film (m ₇ ) produced using the unlaminated hard coat layer (h) was evaluated for birefringence, ultraviolet shielding performance, water vapor shielding performance, and surface scratch resistance. The evaluation results are summarized and described in Table 2.

(Comparative Example 3) Multilayer film (m ₇ h ₁ )

[Manufacture of a multilayer film (m ₇ h ₁ ) with a hard coat layer (h ₁ )]

A multilayer film (m ₇ h ₁ ) having a hard coat layer (h ₁ ) laminated on one surface was produced in the same manner as in Example 1 except that the laminated film (m ₇ ) produced in Comparative Example 2 was used. The manufactured multilayer film (m ₇ h ₁ ) has a 4-layer structure of (d ₁ ) / (e ₁ ) / (d ₁ ) (h ₁ ), with a width of 230 mm and a total thickness of 43 μm (thickness of each layer: 10 μm / 20 μm / 10 μm / 3 μm).

The produced multilayer film (m ₇ h ₁ ) was used to evaluate birefringence, ultraviolet shielding performance, water vapor shielding performance, and surface scratch resistance. The evaluation results are summarized and described in Table 2.

(Comparative example 4) laminated film (m ₈ )

[Manufacture of laminated film (m ₈ )]

Instead of using the resin composition (E ₄ ) instead of the resin composition (E ₁ ), the block copolymer hydride (D ₄ ) produced in Production Example 4 was used instead of the ring-opening metathesis polymer hydrogenated polymer (F ₁ ) as heat. other than a thermoplastic resin, based in the same manner as in Example 1, is formed is manufactured (D ₄₎ of the resin layer of the resin composition (E ₄₎ of layer (e ₄₎ an intermediate layer, containing a hydrogenated block copolymer comprising (d ₄ ) Two kinds of three-layer laminated film (m ₈ ) as the surface layer.

The manufactured multilayer film (m ₈ ) had a three-layer structure of (d ₄ ) / (e ₄ ) / (d ₄ ), with a width of 230 mm and a total thickness of 40 μm (thickness of each layer: 10 μm / 20 μm / 10 μm).

The laminated film (m ₈ ) produced using the unlaminated hard coat layer (h) was evaluated for birefringence, ultraviolet shielding performance, water vapor shielding performance (moisture permeability), and surface damage resistance. The evaluation results are summarized and described in Table 2.

From the results of this example and comparative example, the following cases are known.

A layer (e) containing a resin composition (E) (the resin composition (E) is prepared by blending a block copolymer hydride (D) with an ultraviolet absorber)) is used as an intermediate layer, and an intercalation layer is contained in this layer. The laminated film in which the resin layer (d) of the segment copolymer hydride (D) is used as a surface layer is easily damaged (Comparative Examples 2, 4). Although the moisture permeability is low and the birefringence is excellent and minimized, the scratch hardness of the surface is low and is 6B or less.

A layer (e) containing a resin composition (E) (the resin composition (E) is prepared by blending a block copolymer hydride (D) with an ultraviolet absorber)) as an intermediate layer, and the block containing copolymer is copolymerized. When the resin layer (d) of the hydride (D) is used as the surface of the laminated film of the surface layer and the hard coat layer (h) is further laminated, it is still easy to be injured and insufficient (Comparative Example 3). Although the moisture permeability is low and the birefringence is excellent and minimized, the scratch hardness of the surface is only about B and cannot be improved.

A layer (e) containing a resin composition (E) (the resin composition (E) is prepared by blending an ultraviolet absorber with a block copolymer hydride (D)) as an intermediate layer, and a single layer In the case where the thermoplastic resin (F) having a surface scratch hardness of B, that is, the resin layer (f) of the ring-opening metathesis polymer hydrogenated polymer becomes a laminated film, the scratch resistance is insufficient (Comparative Example 1). Although the moisture permeability is the lowest and the birefringence is small and good, the surface scratch hardness is 2B and it is easy to be injured. Compared with the laminated film (Comparative Examples 2 and 4) using the block copolymer hydride (D) as the surface layer, although the surface scratch hardness became higher, it was insufficient.

A layer (e) containing a resin composition (E) (the resin composition (E) is prepared by blending an ultraviolet absorber with a block copolymer hydride (D)) as an intermediate layer, and the layer contains thermoplasticity When the resin layer (f) of the ring-opening metathesis polymer hydrogenated polymer of the resin (F) is further laminated with a hard coat layer (h) on the surface, the damage resistance is above an allowable level (Examples 1 and 2) , 4, 5). The moisture permeability is the lowest, the birefringence is small and good, and the surface scratch hardness also increases to about H ~ 2H.

A layer (e) containing a resin composition (E) (the resin composition (E) is prepared by blending an ultraviolet absorber with a block copolymer hydride (D)) as an intermediate layer, and the layer contains thermoplasticity When the resin layer (f) of the resin (F) is further laminated with the hard coat layer (h) on the surface, the damage resistance can be greatly improved (Example 3). Although the moisture permeability is higher, it is a very low value compared to the cellulose triacetate film. Although the birefringence is increased, it is sufficiently tolerable when used on the outermost surface side of a liquid crystal display, and the surface scratch hardness is increased. To about 3H.

In the block copolymer hydride (D) used in the present invention, when the weight average molecular weight Mw of the block copolymer (C) is approximately the same, the mechanism capable of maintaining the block copolymer hydride (D) is maintained. Within the range of strength, by increasing Mw (A ₁ ) and decreasing Mw (A ₂ ), Mw (A ₁ ) and Mw (A ₂ ) become very different asymmetric triblock copolymers. The present invention The multilayer film system can further improve the surface scratch hardness (when Examples 1 and 4 are compared with Examples 5 and 6).

    Industrial availability    

The multilayer film of the present invention is a multilayer film having a small birefringence, excellent ultraviolet shielding performance and water vapor shielding properties, and a specific block copolymer hydride with improved surface damage resistance, and is a polarizer for a polarizing film Optical films, such as a protective film, are useful.

Claims (3)

    A multilayer film comprising: (i) layer (e), which comprises 100 parts by weight of a block copolymer hydride (D), and is prepared by blending an ultraviolet absorber of 1.0 part by weight or more and 15.0 parts by weight or less. Resin composition (E), wherein the block copolymer hydride (D) contains at least two polymer blocks (A) having a structural unit derived from an aromatic vinyl compound as a main component, and a source A block copolymer (C) of a block copolymer of a self-chain conjugated diene compound having at least one polymer block (B) as a main component, and a total polymer block (A) and a total block When the weight fraction of the polymer block (B) in the block copolymer (C) is set to wA and wB, the block copolymer in which the ratio wA to wB is 60:40 to 90:10 (C) More than 90% of the carbon-carbon unsaturated bonds of the main chain and side chains and the carbon-carbon unsaturated bonds of the aromatic ring are hydrogenated; (ii) the resin layer (f), which contains Specific thermoplastic resin (F) on at least one or both sides of layer (e), wherein the specific thermoplastic resin (F) is selected from the group consisting of polyester, cycloolefin polymer, polystyrene, styrene copolymer, and (methyl ) More than one type of group consisting of acrylate (co) polymers; and (iii) Hard coating (h), which is laminated on the surface of at least one resin layer (f) in contact with layer (e) as Opposite side face.     The multilayer film according to item 1 of the scope of patent application, wherein the block copolymer (C) has a weight average molecular weight (Mw) of 40,000 to 100,000, and a structural unit derived from an aromatic vinyl compound is used as a main component The two polymer blocks (A ₁ ) and the polymer blocks (A ₂ ) of the components each form both ends of the block copolymer (C), and the weight average molecular weight Mw of the polymer block (A ₁ ) ( a ₁₎ is 20,000 or more and 80,000 or less, the polymer block (a ₂₎ weight average molecular weight Mw of (a ₂₎ is 4,000 or more and 7,000 or less.     The multilayer film according to item 1 or 2 of the scope of the patent application, wherein the scratch hardness of JIS K 5600-5-4 of the surface on which the aforementioned hard coat layer (h) is laminated is H or more.