TWI650365B - Thermoplastic resin film, stretch film, polarizer protective film and polarizing plate - Google Patents

Abstract

An object of the present invention is to provide a thermoplastic resin film having excellent transparency. As a solution to the present invention, a thermoplastic resin film is provided. In the resin composition, an acrylic resin and a polycarbonate resin are added in a total amount of 100% by weight, and the acrylic resin is 50 to 95% by weight. The polycarbonate resin is contained in a proportion of 5 to 50% by weight, and is characterized in that the acrylic resin is a resin containing a copolymer obtained by polymerizing a monomer component, and the monomer component is a total of the monomer component. 100% by weight, 50 to 95% by weight of methyl methacrylate, 5 to 50% by weight of (meth) acrylate represented by the following formula (I), and 0.1 to monofunctional monomers other than these 20% by weight, (Wherein R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group substituted with a cycloalkyl group, a cycloalkyl group, a cycloalkyl group substituted with an alkyl group, an alkyl group substituted with a naphthyl group, and naphthalene group to the alkyl group substituted with a naphthyl group, substituted in the phenyl group, a phenyl group, the phenyl group substituted with an alkyl, dicyclopentadiene or dicyclopentenyl group); at shear rate of 60sec ^- The shear viscosity of the resin composition of ¹ becomes 2500Pa. The temperature T ₂₅₀₀ (℃) satisfies the following formula (a) T ₂₅₀₀ <(1.5 × MVR _PC × W _a × W _a ) / (W _b × W _b ) +245 (a) (where MVR _PC represents the melt volume ratio of a polycarbonate-based resin at 300 ° C, W _a represents the weight% of the (meth) acrylate represented by the formula (I) in the monomer component, and W _b represents the resin composition (% By weight of polycarbonate resin).

Description

Thermoplastic resin film, stretch film, polarizer protection film, and polarizer

The present invention relates to a thermoplastic resin film and a stretched film obtained by stretching the thermoplastic resin film. The present invention also relates to a polarizer protective film composed of a thermoplastic resin film or a stretched film, and a polarizer including the polarizer protective film and a polarizer.

Polycarbonate-based resins generally have excellent heat resistance, dimensional stability, impact resistance, rigidity, and transparency. However, due to insufficient scratch resistance and long-term UV resistance, it also has the disadvantage of generating stress birefringence. In addition, methacrylic resins such as polymethyl methacrylate are known to have excellent transparency, surface hardness, UV resistance, weather resistance, chemical resistance, and the like. However, dimensional stability, impact resistance, and heat resistance are insufficient.

Accordingly, a mixture of a polycarbonate-based resin and a methacrylic resin is expected to make up for the shortcomings of individual components, and to bring substances that can be used in various applications. However, since a mixture of a general polycarbonate resin and a methacrylic resin is opaque, there is a problem that it cannot be used for applications requiring transparency.

Therefore, as a transparent mixture of a polycarbonate resin and a methacrylic resin, Patent Document 1 describes a resin composition containing a polymerized aromatic polycarbonate resin and a monomer unit of methyl methacrylate. A methacrylic resin obtained from 5 to 95% by weight, a methacrylic acid ester monomer unit having an ester group having a cyclic carbon group of 5 to 95% by weight, and 0 to 40% by weight of an α, β-unsaturated monomer unit.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Unexamined Patent Publication No. 1-1749

However, the thermoplastic resin film obtained from the resin composition described in Patent Document 1 is melt-extruded, and the obtained thermoplastic resin film may become cloudy and reduce transparency. Therefore, the transparency of the thermoplastic resin film is still improved. room.

In addition, in order to impart specific functions to a thermoplastic resin film or a stretched film formed by stretching a thermoplastic resin film, a surface treatment layer such as a hard coat layer may be provided on the film surface. However, a thermoplastic resin film or a stretched film provided with a surface treatment layer is often easily broken when grasped with a hand or a jig during steps such as transportation or bonding with other members. Therefore, when a surface-treated layer is provided for a thermoplastic resin film or a stretched film, it is desired that it is difficult to break even if grasped by a hand or a jig, and has excellent toughness.

An object of the present invention is to provide a thermoplastic resin film having excellent transparency and excellent toughness, and a stretched film obtained by stretching the thermoplastic resin film, and further provide a thermoplastic resin film or a stretched film therefrom. The polarizer protection film and the polarizer including the polarizer protection film and the polarizer.

In order to solve the above problems, the present invention provides the following inventions.

<1> A thermoplastic resin film, which is a thermoplastic resin film composed of a resin composition, in which an acrylic resin and a polycarbonate resin are added in an amount of 100% by weight relative to the total of the acrylic resin and the polycarbonate resin. The resin is contained in a proportion of 50 to 95% by weight, and the polycarbonate resin is contained in a proportion of 5 to 50% by weight. The acrylic resin is a resin containing a copolymer obtained by polymerizing a monomer component. 50 to 95% by weight of methyl methacrylate and 5 to 50% by weight of (meth) acrylate represented by the following formula (I) with respect to 100% by weight of the total of the monomer components, Monofunctional monomer is composed of 0.1 to 20% by weight, (Wherein R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group substituted with a cycloalkyl group, a cycloalkyl group, a cycloalkyl group substituted with an alkyl group, an alkyl group substituted with a naphthyl group, and naphthalene group to the alkyl group substituted with a naphthyl group, substituted in the phenyl group, a phenyl group, the phenyl group substituted with an alkyl, dicyclopentadiene or dicyclopentenyl group); at shear rate of 60sec ^- The shear viscosity of the resin composition of ¹ becomes 2500Pa. The temperature T ₂₅₀₀ (℃) satisfies the following formula (a) T ₂₅₀₀ <(1.5 × MVR _PC × W _a × W _a ) / (W _b × W _b ) +245 (a) (where MVR _PC represents the melt volume ratio of a polycarbonate-based resin at 300 ° C, W _a represents the weight% of the (meth) acrylate represented by the formula (I) in the monomer component, and W _b represents the resin composition (% By weight of polycarbonate resin).

<2> The thermoplastic resin film according to the aforementioned <1>, wherein the weight average molecular weight of the acrylic resin is 50,000 to 200,000.

<3> The thermoplastic resin film according to the aforementioned <1> or <2>, wherein the (meth) acrylate represented by formula (I) is cyclohexyl methacrylate, phenyl methacrylate, or naphthyl methacrylate And at least one selected from the group consisting of dicyclopentyl methacrylate and dicyclopentenyl methacrylate.

<4> The thermoplastic resin film according to any one of the aforementioned <1> to <3>, wherein the monofunctional mono-system methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate are formed At least one selected from the group.

<5> The thermoplastic resin film according to any one of <1> to <4>, which is produced by melt coextrusion.

<6> The thermoplastic resin film according to any one of <1> to <5>, wherein the surface is provided with a surface treatment layer on at least one side.

<7> A stretched film, which is stretched as described in any one of the above <1> to <5> Obtained from a thermoplastic resin film.

<8> The stretched film according to the aforementioned <7>, wherein a surface-treated layer is provided on at least one side of the surface.

<9> A polarizer protective film, which is composed of a thermoplastic resin film according to any one of the aforementioned <1> to <6>.

<10> A polarized protective film, which is composed of a stretched film as described in <7> or <8> above.

<11> A polarizing plate comprising a polarizer and a polarizer protective film as described in <9> or <10>, which is disposed on at least one side of the polarizer.

According to the present invention, a thermoplastic resin film having excellent transparency and excellent toughness, and a stretched film obtained by stretching the same are obtained. The thermoplastic resin film and the stretched film formed by stretching the thermoplastic resin film of the present invention are suitable for use as a polarizer protective film.

The thermoplastic resin film of the present invention is composed of a resin composition containing a specific acrylic resin and a specific polycarbonate resin in a specific ratio.

<Acrylic resin>

The acrylic resin used in the present invention is a resin containing a copolymer. The copolymer is obtained by polymerizing a monomer component. The monomer component is 50 to 95% by weight of methyl methacrylate, and the following formula ( (I) is composed of 5 to 50% by weight of a (meth) acrylate, and 0.1 to 20% by weight of a monofunctional monomer other than that, (Wherein R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group substituted with a cycloalkyl group, a cycloalkyl group, a cycloalkyl group substituted with an alkyl group, an alkyl group substituted with a naphthyl group, and naphthalene Group, naphthyl substituted with alkyl, alkyl substituted with phenyl, phenyl, phenyl substituted with alkyl, dicyclopentyl or dicyclopentenyl).

In the present specification, the term "(meth) acrylfluorenyl" means "acrylfluorenyl" or "methacrylfluorenyl".

A commercially available product of methyl methacrylate may be used as it is, or it may be used in other synthetic methods according to a conventionally known method.

From the point that methyl methacrylate improves the transparency and weather resistance of the acrylic resin, the copolymerization pair included in the acrylic resin is contained in an amount of 50 to 95% based on 100% by weight of the total of the monomer components. The percentage by weight is preferably a ratio of 60 to 90% by weight.

In the above formula (I), R ¹ represents a hydrogen atom or a methyl group, and is preferably a methyl group.

The (meth) acrylate represented by formula (I) (hereinafter sometimes referred to as (meth) acrylate) has at least one alicyclic hydrocarbon group or aromatic hydrocarbon group Alternatively, a commercially available product can be used directly, or it can be used in a method synthesized by other methods according to a conventionally known method.

In formula (I), R ² represents "alkyl substituted with cycloalkyl", "cycloalkyl", "cycloalkyl substituted with alkyl", "alkyl substituted with phenyl", "Phenyl", "phenyl substituted with alkyl", "alkyl substituted with naphthyl", "naphthyl", "naphthyl substituted with alkyl", "dicyclopentyl" or "Dicyclopentenyl".

As the "alkyl group" of the "alkyl group substituted by cycloalkyl group" represented by R ² , an alkyl group having 1 to 4 carbon atoms is preferred, and examples thereof include methyl, ethyl, n-propyl, and isopropyl "Cycloalkyl" as a substituent, preferably n-butyl, isobutyl, tert-butyl, etc., is preferably a cycloalkyl group having 5 to 12 carbon atoms. Examples include cyclopentyl and cyclohexyl. , Cyclobutyl, cyclooctyl, cyclododecyl and the like. However, the number of "cycloalkyl" substituents and the position of substitution in the alkyl group are not particularly limited. Examples of the "alkyl group substituted with cycloalkyl group" represented by R ² include methyl, ethyl, and cycloalkyl substituted with at least one hydrogen atom (H) having the above-mentioned carbon number of 5 to 12, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl and the like.

The "cycloalkyl group" represented by R ² is preferably a cycloalkyl group having 5 to 12 carbon atoms, and examples thereof include cyclopentyl, cyclohexyl, cyclobutyl, cyclooctyl, and cyclododecyl. Moreover, if necessary, it may be further substituted with a substituent such as a hydroxyl group, an amino group, or a sulfo group.

As the "cycloalkyl group" represented by "cycloalkyl group substituted with alkyl group" represented by R ² , a cycloalkyl group having 5 to 12 carbon atoms is preferred, and examples thereof include cyclopentyl, cyclohexyl, cyclobutyl, Cyclooctyl, cyclododecyl, and the like, as the "alkyl" as a substituent thereof, an alkyl group having 1 to 4 carbon atoms is preferred, and examples thereof include methyl, ethyl, n-propyl, and isopropyl , N-butyl, isobutyl, tert-butyl and the like. However, the number of the "alkyl" of the substituent and the position of the substitution in the cycloalkyl group are not particularly limited. Examples of the "cycloalkyl group substituted with alkyl group" represented by R ² include cyclopentyl group, cyclohexyl group, cycloalkyl group substituted with alkyl group having at least one hydrogen atom (H) having the above-mentioned carbon number of 1 to 4, Cyclobutyl, cyclooctyl, cyclododecyl and the like.

As the "alkyl group" of the "alkyl group substituted by phenyl group" represented by R ² , an alkyl group having 1 to 4 carbon atoms is preferred, and examples thereof include methyl, ethyl, n-propyl, and isopropyl. , N-butyl, isobutyl, tert-butyl and the like. However, the number of "phenyl" groups in the substituent and the substitution position in the alkyl group are not particularly limited. Examples of the "alkyl group substituted with phenyl group" represented by R ¹ include methyl, ethyl, n-propyl, isopropyl, and n having at least one hydrogen atom (H) substituted with phenyl. -Butyl, isobutyl, tert-butyl, etc. (e.g. benzyl, phenethyl, etc.).

The "phenyl" represented by R ² is not particularly limited, and may be further substituted with a substituent such as a hydroxyl group, an amino group, or a sulfo group.

The "alkyl" as a substituent of the phenyl group of "phenyl substituted with an alkyl group" represented by R ² is preferably an alkyl group having 1 to 4 carbon atoms, and examples thereof include methyl, ethyl, and n- Propyl, isopropyl, n-butyl, isobutyl, tert-butyl and the like. However, the number of the "alkyl" group of the substituent and the substitution position at the phenyl group are not particularly limited. Examples of the "phenyl group substituted with an alkyl group" represented by R ¹ include o-tolyl, m-tolyl, and p-tolyl.

As the "alkyl group" of the "alkyl group substituted with naphthyl group" represented by R ² , an alkyl group having 1 to 4 carbon atoms is preferred, and examples thereof include methyl, ethyl, n-propyl, and isopropyl , N-butyl, isobutyl, tert-butyl and the like. However, the number of "naphthyl" of the substituent and the substitution position at the alkyl group are not particularly limited. Examples of the "naphthyl-substituted alkyl group" represented by R ² include methyl, ethyl, n-propyl, isopropyl, and n having at least one hydrogen atom (H) substituted with naphthyl. -Butyl, isobutyl, tert-butyl, etc. (for example, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylmethyl, 2-naphthylethyl, etc.).

The "naphthyl" represented by R ² is not particularly limited, and may be further substituted with a substituent such as a hydroxyl group, an amino group, or a sulfo group.

The "alkyl group" as a substituent of the naphthyl group of the "naphthyl group substituted with an alkyl group" represented by R ² is preferably an alkyl group having 1 to 4 carbon atoms, and examples include methyl, ethyl, and Propyl, isopropyl, n-butyl, isobutyl, tert-butyl and the like. However, the number of "alkyl" groups of the substituent and the position of substitution at the naphthyl group are not particularly limited. Examples of the "naphthyl substituted with an alkyl group" represented by R ² include methylnaphthyl and ethylnaphthyl.

The "dicyclopentyl" and "dicyclopentenyl" represented by R ² may be further substituted with a substituent such as an alkyl group, a hydroxyl group, an amino group, or a sulfo group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, and examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl. .

R ^{2 is} preferably cycloalkyl (preferably cyclohexyl), phenyl, naphthyl, dicyclopentyl, dicyclopentenyl, and more preferably cyclohexyl and phenyl.

In the present invention, the (meth) acrylate is preferably cyclohexyl methacrylate, phenyl methacrylate, naphthyl methacrylate, methyl Dicyclopentyl acrylate and dicyclopentenyl methacrylate, more preferably cyclohexyl methacrylate and phenyl methacrylate.

The (meth) acrylate may be used alone or in combination of two or more.

The (meth) acrylic acid ester is 100% by weight with respect to the total amount of the monomer components, and the copolymerization pair included in the acrylic resin contains 5 to 50% by weight, and preferably 10 to 40% by weight. When the content of the (meth) acrylic acid ester is less than 5% by weight, the compatibility with the polycarbonate resin of the acrylic resin decreases, and the transparency of the thermoplastic resin film decreases. In addition, when the content of the (meth) acrylate exceeds 50% by weight, in addition to the decrease in compatibility (transparency), the weather resistance of the thermoplastic resin film also decreases.

Monofunctional monomers other than methyl methacrylate and (meth) acrylates represented by formula (I) (hereinafter sometimes referred to as monofunctional monomers) may be used as they are, or they may be produced by conventional methods. Used by others synthesized.

The monofunctional monomer is not particularly limited as long as it is copolymerizable with methyl methacrylate and / or (meth) acrylate, but examples include methyl methacrylate and (meth) acrylate Other than (meth) acrylic acid alkyl esters, Alkenyl cyanide (for example, acrylonitrile, methacrylonitrile, etc.), acrylic acid, methacrylic acid, maleic anhydride, and the like. Among these, alkyl methacrylate or alkyl acrylate is preferred, and alkyl acrylate is particularly preferred.

Examples of the alkyl methacrylate include ethyl methacrylate, N-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, sec-butyl methacrylate, isobutyl methacrylate, methacrylic acid 2 -Ethylhexyl and the like. Among these, an alkyl methacrylate having an alkyl group having 2 to 4 carbon atoms is preferable. Examples of the acrylic alkyl group include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, butyl acrylate (n-butyl acrylate, t-butyl acrylate, sec-butyl acrylate, and acrylic acid). Isobutyl ester), 2-ethylhexyl acrylate, and the like.

In the present invention, as the monofunctional monomer, methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate are preferred.

Monofunctional monomers can be used alone or in combination of two or more.

The monofunctional monomer is 100% by weight with respect to the total amount of the monomer component, and includes the copolymerization pair included in the acrylic resin in a proportion of 0.1 to 20% by weight, preferably 0.2 to 10% by weight, and more preferably 0.3 to Contained in a proportion of 5% by weight. When the content of the monofunctional monomer is less than 0.1% by weight, thermal decomposition of the acrylic resin may be easily caused. Moreover, when content of a monofunctional monomer exceeds 20 weight%, the transparency and heat resistance of a thermoplastic resin film may fall.

In addition, as a monomer component constituting the acrylic resin, the aforementioned methyl methacrylate, the (meth) acrylate represented by the formula (I), and a monofunctional monomer may be included within a range that does not impair the effects of the present invention. Other monomers.

For the polymerization method when polymerizing monomer components, there is no particular The limitation is, for example, a known polymerization method such as block polymerization, solution polymerization, suspension polymerization, or emulsion polymerization. In the polymerization, a radical polymerization initiator is usually used, and a radical polymerization initiator and a chain transfer agent are preferably used.

As the polymerization initiator, for example, organic peroxides such as azo compounds such as azobisisobutyronitrile, lauryl peroxide, and 1,1-bis (t-butylperoxy) cyclohexane are preferably used. Free radical polymerization initiator. The polymerization initiator may be used alone or in combination of two or more. The amount of the polymerization initiator may be appropriately determined depending on the type of monomer, its ratio, and the like.

As the chain transfer agent, for example, thiols such as n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, and 2-ethylhexyl thioglycolate are preferably used. . The chain transfer agent may be used alone or in combination of two or more. The amount of the chain transfer agent may be appropriately determined depending on the type of monomer, its ratio, and the like.

The polymerization temperature, polymerization time, and the like when polymerizing the monomer components may be appropriately determined according to the type of monomer, the ratio of the monomers, and the like, and are not particularly limited.

The weight average molecular weight of the acrylic resin system is preferably 50,000 to 200,000, and more preferably 80,000 to 200,000. When the acrylic resin has a weight average molecular weight within such a range, the fluidity becomes excellent, and when a resin composition is produced, melt-kneading is easily performed to improve processability. In addition, the mechanical strength of the thermoplastic resin film obtained from the resin composition is improved.

The melt mass flow rate (MFR) at 230 ° C of the acrylic resin measured at a load of 3.8 kg is preferably 0.1 to 50 g / 10 minutes, and more preferably 0.2 to 30 g / 10 minutes. The acrylic resin has such a range In the case of MFR, the fluidity becomes excellent, and when a resin composition is produced, melt-kneading is easily performed. In addition, the mechanical strength of the thermoplastic resin film obtained from the resin composition is improved.

The acrylic resin may contain a release agent, an ultraviolet absorber, a dye, a pigment, a polymerization inhibitor, and an antioxidant, in addition to the copolymer obtained by polymerizing the monomer components, as long as the effect of the present invention is not impaired. Additives such as flame retardants, reinforcing materials, and the like are preferably 95 to 99.995 parts by weight relative to 100 parts by weight of the total acrylic resin.

<Polycarbonate resin>

Examples of the polycarbonate-based resin include those obtained by reacting a divalent phenol with a carbonylating agent by an interfacial polycondensation method or a melt transesterification method; and a carbonate prepolymer by a solid-phase transesterification method. Those obtained by polymerization, etc .; those obtained by polymerization of a cyclic carbonate compound by a ring-opening polymerization method, and the like.

Examples of divalent phenols include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, and bis {(4-hydroxy-3,5- Dimethyl) phenyl} methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2-bis ( 4-hydroxyphenyl) propane (commonly known as bisphenol A), 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis {(4-hydroxy-3,5 -Dimethyl) phenyl} propane, 2,2-bis {(4-hydroxy-3,5-dibromo) phenyl} propane, 2,2-bis {(3-isopropyl-4-hydroxy) Phenyl} propane, 2,2-bis {(4-hydroxy-3-phenyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,4-bis (4 -Hydroxyphenyl) -2-methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 1, 1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -4-isopropylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3 , 3,5-trimethylcyclohexane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis {(4-hydroxy-3-methyl) phenyl} fluorene, α, α '-Bis (4-hydroxyphenyl) -o-diisopropylbenzene, α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene, α, α'-bis (4- (Hydroxyphenyl) -p-diisopropylbenzene, 1,3-bis (4-hydroxyphenyl) -5,7-dimethyladamantane, 4,4'-dihydroxydiphenylphosphonium, 4, 4'-dihydroxydiphenylsulfene, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl ether, 4, 4'-dihydroxydiphenyl ester and the like. These can be used alone or in combination of two or more.

Among these divalent phenols, bisphenol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, and 2,2-bis (4-hydroxyphenyl) butane are preferred. , 2,2-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,2-bis ( 4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and α, α'-bis (4-hydroxy (Phenyl) -m-diisopropylbenzene. Particularly preferred are bisphenol A alone, or bisphenol A, and 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 2,2-bis {( 4-hydroxy-3-methyl) phenyl} propane and at least one selected from the group consisting of α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene and used in combination.

Examples of the carbonylating agent include carbonyl halides (phosgene, etc.), carbonates (diphenyl carbonate, etc.), and haloformates (dihaloformate of divalent phenol, etc.). These can be used alone or in combination of two or more on.

The weight average molecular weight of the polycarbonate-based resin used in the present invention is preferably 20,000 to 60,000, and more preferably 22,000 to 40,000. When the polycarbonate-based resin has a weight average molecular weight within such a range, the fluidity becomes excellent, and when a resin composition is produced, melt-kneading is easily performed to improve processability. In addition, the impact resistance and heat resistance of the thermoplastic resin film obtained from the resin composition are improved.

Polycarbonate-based resin as measured at a load of 1.2kg melt volume rate of 300 deg.] C (the MVR) is preferably 8 ~ 100cm ^3/10 minutes and more preferably 10 ~ 85cm ^3/10 min. When the polycarbonate-based resin has an MVR within this range, the fluidity is excellent, and melt-kneading is easy when the resin composition is produced. In addition, the mechanical strength of the thermoplastic resin film obtained from the resin composition is improved.

The polycarbonate resin may contain additives such as a release agent, an ultraviolet absorber, a dye, a pigment, a polymerization inhibitor, an antioxidant, a flame retardant, and a reinforcing material, as long as the effects of the present invention are not impaired.

<Resin composition>

The resin composition is contained in an amount of 50 to 95% by weight of the acrylic resin and 5 to 50% by weight of the polycarbonate resin based on 100% by weight of the total of the acrylic resin and the polycarbonate resin. When the content of the polycarbonate-based resin is less than 5% by weight, the mechanical strength of the thermoplastic resin film obtained from the resin composition becomes insufficient. When the content of the polycarbonate-based resin exceeds 50% by weight, the resin composition and heat are reduced. Transparency of plastic resin film. The acrylic resin is preferably contained in a proportion of 50 to 80% by weight, and the polycarbonate resin is preferably contained in a proportion of 20 to 50% by weight.

In the resin composition of the present invention, in addition to the acrylic resin and the polycarbonate resin, an ultraviolet absorber, an antioxidant, a compatibilizer, a stabilizer, a colorant, Foaming agents, lubricants, release agents, antistatic agents, flame retardants, flame retardant additives and other conventional additives. In addition, a small amount of other thermoplastic resins can be added. These additives may be added during melt-kneading of a resin mixture containing an acrylic resin and a polycarbonate resin, or may be added before or after the melt-kneading. When the additive is added, the total content of the acrylic resin and the polycarbonate resin is preferably 70 to 99.995 parts by weight based on 100 parts by weight of the total amount of the resin composition.

Examples of the ultraviolet absorber include a triazine ultraviolet absorber, a benzophenone ultraviolet absorber, a benzotriazole ultraviolet absorber, a benzoate ultraviolet absorber, and a cyanoacrylate ultraviolet absorber. Wait. These can be used alone or in combination of two or more.

Examples of the triazine-based ultraviolet absorber include 2,4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3,5-triazine, and 2,4-diphenyl -6- (2-hydroxy-4-ethoxyphenyl) -1,3,5-triazine, 2,4-diphenyl- (2-hydroxy-4-propoxyphenyl) -1 , 3,5-triazine, 2,4-diphenyl- (2-hydroxy-4-butoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- ( 2-hydroxy-4-butoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-hexyloxyphenyl) -1,3, 5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-octyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-dodecyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy- 4-benzyloxyphenyl) -1,3,5-triazine and the like.

Examples of the benzophenone-based UV absorber include 2,4-dihydroxy-benzophenone, 2-hydroxy-4-methoxy-benzophenone, and 2-hydroxy-4-n-octyloxy -Benzophenone, 2-hydroxy-4-dodecyloxy-benzophenone, 2-hydroxy-4-octadecyloxy-benzophenone, 2,2'-dihydroxy-4 -Methoxy-benzophenone, 2,2'-dihydroxy-4,4'-dimethoxy-benzophenone, 2,2 ', 4,4'-tetrahydroxy-benzophenone Wait.

Examples of the benzotriazole-based ultraviolet absorber include 2- (2'-hydroxy-5-methylphenyl) benzotriazole and 2- (2'-hydroxy-3 ', 5'-di-t -Butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5 ' -Methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'- tert-butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimidemethyl) -5'-methylphenyl) benzotriazole, 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), 2- (2'- Hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2 (2'-hydroxy-3 ', 5'-di-tert-butylphenyl)- 5-chlorobenzotriazole, (2 (2'-hydroxy-3 ', 5'-di-tert-pentylphenyl) -5-chlorobenzotriazole, 2 (2'-hydroxy-3', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, (2 (2'-hydroxy-3 ', 5'-di-tert-pentylphenyl) -5-chlorobenzo Triazole and so on.

Examples of the benzoate-based ultraviolet absorber include 2,4-di-t-butylphenyl-3 ', 5'-di-t-butyl-4'-hydroxybenzoate, 2, 6- Di-t-butylphenyl-3 ', 5'-di-t-butyl-4'-hydroxybenzoate, n-hexadecyl-3,5-di-t-butyl-4 -Hydroxybenzoate and n-octadecyl-3,5-di-t-butyl-4-hydroxybenzoate, etc.

Examples of the cyanoacrylate-based ultraviolet absorber include 2'-ethylhexyl-2-cyano-3,3-diphenylacrylate, ethyl-2-cyano-3- (3 ', 4 '-Methylenedioxyphenyl) -acrylate and the like.

Examples of the ultraviolet absorber include triazine-based ultraviolet absorbers, such as "Kemisorb 102" manufactured by CHEMIPRO Chemical Co., Ltd., and "AdekastabLAF70" manufactured by ADEKA Co., Ltd., and benzotriazole-based ultraviolet absorbers. Commercial products such as "AdekastabLA31" manufactured by ADEKA Corporation are listed.

The weight average molecular weight of the ultraviolet absorber is preferably 500 to 1,000, and more preferably 550 to 700. When the weight average molecular weight is too small, it is easy to volatilize during molding, and when the molecular weight is too large, the compatibility of the acrylic resin or polycarbonate resin tends to decrease.

The molar absorption coefficient of the ultraviolet absorber at a wavelength at which absorption is extremely large is preferably 10 L / mol. cm or more, more preferably 15L / mol. cm or more. Since the molar absorption coefficient of the ultraviolet absorber is in the above specific range, the ultraviolet absorption energy can be changed to be more excellent, and the content of the ultraviolet absorber can be reduced.

Examples of the antioxidant include hindered phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. These can be used alone or in combination of two or more.

Examples of the hindered phenol-based antioxidant include Ciba- "Irganox1010", "Irganox1035", "Irganox1076", "Irganox1222", "Antigene P", "Antigene 3C", "Antigene FR", "SumilizerS", "SumilizerGA80" manufactured by Geigy Co., Ltd. ", Commercially available products such as" AdekastabAO70 "," AdekastabAO80 "," AdekastabAO503 "made by ADEKA Co., Ltd.

Examples of the phosphorus-based antioxidant include ginseng (2,4-di-t-butylphenyl) phosphite, 2-[[2,4,8,10-ethane (1,1-dimethylethyl) ) Dibenzo [d, f] [1,3,2] dioxoPhosphepine-6-yl] oxy] -N, N-bis [2-[[2,4,8,10- 1,1-dimethylethyl) dibenzo [d, f] [1,3,2] dioxophosphepine-6-yl] oxy] -ethyl] Ethanamine, diphenyltridecyl Phosphite, triphenylphosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octylphosphite, bis (2,6-di-tert-butyl 4-methylphenyl) pentaerythritol diphosphite and the like. Among these, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite is preferred.

Examples of the sulfur-based antioxidant include dimethyl disulfide, diethyl disulfide, di-n-propyl disulfide, di-n-butyl disulfide, and di-sec-butyl disulfide. Sulfide, di-tert-butyl disulfide, di-tert-pentyl disulfide, dicyclohexyl disulfide, di-tert-octyl disulfide, di-n-dodecyl disulfide Compounds, di-tert-dodecyl disulfide, and the like. Among these, di-tert-alkyl disulfide is preferable, and di-tert-dodecyl disulfide is more preferable.

The resin composition is obtained, for example, by melt-kneading a resin mixture containing an acrylic resin and a polycarbonate resin.

In order to uniformly melt-kneading of these resins, melt-kneading is generally 180 ~ 320 ℃, preferably at a temperature of 200 ~ 300 ℃, typically at shear rate of 10 ~ 200sec ^-1, preferably to 30 ~ 150sec ^- The cutting speed of ¹ is performed.

As a machine used for melt-kneading, a general mixer, a kneader, etc. can be used. Specific examples include a one-axis kneading extruder, a two-axis kneading extruder, a belt mixer, a Henschel mixer, an internal mixer, and a drum. Among these, a biaxial kneading extruder is preferred. Further, if necessary, the melt-kneading can be performed in an atmosphere of an inert gas such as a nitrogen gas, an argon gas, or a helium gas.

By doing so, a resin composition having excellent transparency can be obtained. Although a thermoplastic resin film is obtained from the resin composition as described later, it is not limited to this, and it is processed into a desired shape to obtain a molded body. This molded body is also excellent in transparency.

For the molding process, for example, a resin composition obtained by melt-kneading an acrylic resin and a polycarbonate resin can be directly used. After the resin composition is formed into a specific shape such as a pellet, the resin composition in this specific shape can be used. The forming method is not particularly limited, and examples thereof include an injection molding method, a press molding method, and a melt extrusion molding method.

The molded body is useful as, for example, an electro-optical material (a material for a lens, a disc substrate, a light guide plate, etc.), a cover material (a material for a cover such as a display), a resin glazing material, and the like.

<Thermoplastic resin film>

The thermoplastic resin film of the present invention has a shear viscosity of 2500 Pa at a shear rate of the resin composition of 60 sec ^-1 . The temperature T of s ₂₅₀₀ (° C) must satisfy the following formula (a).

T ₂₅₀₀ <(1.5 × MVR _PC × W _a × W _a ) / (W _b × W _b ) +245 (a) In the formula, MVR _PC represents the melt volume ratio of polycarbonate resin at 300 ° C, W _a represents the weight% of the (meth) acrylate represented by the formula (I) in the monomer component, and W _b represents the weight% of the polycarbonate-based resin in the resin composition.

By satisfying the formula (a), occurrence of white turbidity is suppressed, and a thermoplastic resin film having excellent transparency is obtained. When the formula (a) is not satisfied, it is liable to become cloudy and a thermoplastic resin film having excellent transparency cannot be obtained.

As a method for obtaining a thermoplastic resin film from a resin composition, as described later, a melt extrusion molding method is preferred. In the melt extrusion molding method, a resin composition is melt-kneaded by an extruder, and the molten resin is extruded into a film shape from a die continuously to form a film. Between the molten resin and the extrusion from the die, the molten resin usually gives a shear stress at a shear rate of 60 sec ^-1 . When this shear stress is imparted, the viscosity of the molten resin (ie, the shear viscosity) is usually 2500 Pa because it is easy to extrude the molten resin. s or less. Shear viscosity can be expected by adjusting the temperature of the molten resin when shear stress is applied. When the shear viscosity is reduced, the temperature of the molten resin can be increased. When the shear viscosity is further increased, the molten resin can be reduced. Temperature.

When the present inventors examined the relationship between the resin composition and the occurrence of white turbidity in the obtained thermoplastic resin film, they found that increasing the temperature of the molten resin at the time when the shear stress is applied makes it easier for the thermoplastic resin film to become white turbid, As a result of the investigation, it was found that the resin composition that became the raw material of the thermoplastic resin film had a shear viscosity of 2500 Pa at a shear rate of 60 sec ^-1 . When the temperature T _{2500 of} s is lower than a specific value, that is, when the above formula (a) is satisfied, a thermoplastic resin film having excellent transparency is obtained.

When the resin composition satisfies the above formula (a), the following reasons are considered as reasons for obtaining a thermoplastic resin film having excellent transparency.

First, the present inventors found that the resin composition has a fog point, and this fog point is slightly equal to the value calculated from the right side of the above formula (a). Furthermore, the present inventors have found that when the temperature of the molten resin when the shear stress is imparted is equal to or higher than the fog point of the resin composition, the thermoplastic resin film is liable to become cloudy. From the above, it is considered that the temperature of the molten resin when the shear stress is imparted, that is, the shear viscosity of the resin composition at a shear speed of 60 sec ^-1 becomes 2500 Pa. If the temperature T _{2500 of} s is lower than the value calculated from the right side of the above formula (a), it can be melt-extruded at a temperature lower than the fog point of the resin composition to suppress the occurrence of white turbidity. A thermoplastic resin film with excellent transparency.

In this specification, the fog point of a resin composition refers to a method of increasing a set temperature of a mold by a melt extrusion molding method to produce a thermoplastic resin film, and measuring the total light transmittance of the obtained thermoplastic resin film in accordance with JIS K7361-1. In the case of melt extrusion molding of a thermoplastic resin film whose total light transmittance is 85% or less, the set temperature of the mold degree.

The thickness of the thermoplastic resin film is preferably 10 to 1000 μm, more preferably 20 to 500 μm, and even more preferably 20 to 300 μm.

As a method for obtaining a thermoplastic resin film from a resin composition, for example, first, a resin composition containing an acrylic resin and a polycarbonate resin is obtained, and second, the resin composition is subjected to a melt extrusion molding method and a solution flow. Forming methods such as stretch film method and hot stamping method. Among them, a melt extrusion molding method is preferred.

As the melt extrusion molding method, for example, first, an acrylic resin and a polycarbonate resin are mixed, and if necessary, the other components described above are also mixed to obtain a resin composition. Second, the obtained resin composition is passed through a shaft or It is a two-axis extruder for melt-kneading. Furthermore, the molten resin is continuously extruded from the T die into a film shape. Further, the molten resin is continuously extruded from the T die into a pair. The surface is formed by holding between smooth metal rolls. Cooling to obtain a polarized photoprotective film. The method of mixing acrylic resin, polycarbonate resin, and other components if necessary is not particularly limited. Any known method can be used. A super mixer or an internal mixer can be used, and one-axis or two-axis extrusion can be used. Coming out for melting and kneading, you can also combine these.

The thermoplastic resin film is preferably a film composed of a single layer, and may be a film composed of two or more layers within a range that does not impair the effects of the present invention. When the thermoplastic resin film is a multilayer film, each layer may be formed from a resin composition having the same composition, or may be formed from resin compositions having different compositions. The so-called resin composition of different composition refers to the resin contained Although the kind of resin is different, although the kind of resin is the same, but the content of each resin is different, the kind or content of the resin is the same, but the additives are different, etc., in any case.

The thermoplastic resin film can be suitably used as a polarizer protection film. Thermoplastic resin films can be laminated to, for example, polarizer photoprotective films, for example, building lighting members such as windows or shed roof materials, vehicle lighting members such as windows, agricultural lighting members such as greenhouses, lighting members, front filters, etc. Display components.

<Stretched film>

The stretched film is obtained by stretching a thermoplastic resin film. The stretched film is formed by stretching a thermoplastic resin film, and like the thermoplastic resin film, it suppresses the occurrence of cloudiness and has excellent transparency. Since the stretched film is stretched, it has excellent mechanical properties.

Examples of stretching include uniaxial stretching and biaxial stretching. Among these, biaxial stretching is preferred.

Examples of the biaxial stretching include sequential stretching and simultaneous biaxial stretching. Examples of the stretching direction include a mechanical flow direction of an unstretched film (that is, a thermoplastic resin film), a direction perpendicular to the mechanical flow direction, and a direction oblique to the mechanical flow direction. The stretching ratio is preferably 1.1 to 3.0 times. Here, in this specification, the mechanical flow direction is defined as the longitudinal direction, the longitudinal stretching is defined as the longitudinal stretching, the direction perpendicular to the mechanical flow direction is defined as the lateral direction, and the lateral stretching is defined. For horizontal stretching.

The stretched film can be suitably used as a polarizer protection film. In addition to the polarizer protective film, the stretched film can be laminated to, for example, a building lighting member such as a window or a shed roof material, a vehicle lighting member such as a window, an agricultural lighting member such as a greenhouse, a lighting member, or a front filter. And other display components.

The thermoplastic resin film or stretched film of the present invention preferably has a surface-treated layer on at least one side of the film, and preferably on one side. Since the surface treatment layer is provided by the thermoplastic resin film or the stretched film, specific functions can be provided in accordance with the type of the surface treatment layer. Examples of the surface treatment layer include [a] a hard coating layer for preventing scratches on the surface, [b] an antistatic layer, [c] an anti-reflection layer, [d] an antifouling layer, and [e] responsible for raising the vision An anti-glare layer that prevents the reflection of external light, and reduces the ripples caused by the interference of a prism sheet and a color filter.

A thermoplastic resin film or a stretched film having a surface-treated layer on at least one side of the present invention suppresses the occurrence of white turbidity, is excellent in transparency, is difficult to break even when grasped by a hand or a jig, and has excellent toughness.

When the surfaces on both sides of the thermoplastic resin film or the stretched film are provided with surface treatment layers, the types of the surface treatment layers or the composition of the surface treatment layers constituting the surfaces on both sides may be the same or different from each other.

(Hard coating)

Hard coating has improved surface hardness of thermoplastic resin film or stretched film This function is provided for the purpose of preventing scratches on the surface. The hard coat layer is preferably the pencil hardness specified in JIS K 5600-5-4: 1999 "General Test Methods for Coatings-Part 5: Mechanical Properties of Coating Films-Section 4: Scratch Hardness (Pencil Method)" The test (the optical film having a hard coating layer was measured on a glass plate) indicates a value of H or harder.

The hard coat layer can be formed by applying a hardening coating on at least one surface of a thermoplastic resin film or a stretched film to form a hardening coating film, and then hardening the coating film.

The material forming the hard coat layer is generally hardened by heat or light. For example, organic hard-coat materials such as silicone-based, melamine-based, epoxy-based, acryl-based, urethane acrylate-based, and inorganic hard-coat materials such as silicon dioxide can be cited. Among these, since the adhesion to a thermoplastic resin film or a stretched film is good and the productivity is excellent, it is preferable to use an urethane acrylate-based or polyfunctional acrylate-based hard coating material.

The hard coating layer is intended to contain various fillers for the purpose of adjusting the refractive index, improving the bending elastic modulus, stabilizing the volume shrinkage rate, and further improving heat resistance, antistatic properties, and anti-glare properties. The hard coat layer may also contain additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, leveling agents, and defoamers.

(Antistatic layer)

The antistatic layer is provided for the purpose of imparting conductivity to the surface of a thermoplastic resin film or a stretched film, and suppressing effects due to static electricity. Antistatic In the formation of the layer, for example, a method of applying a resin composition containing a conductive substance (antistatic agent) to a thermoplastic resin film or a stretched film can be employed. For example, by coexisting an antistatic agent in the hard coating material used for the formation of the hard coat layer described above, an antistatic hard coat layer can be formed.

(Anti-reflection layer)

The anti-reflection layer is a layer for preventing external light reflection, and is provided on the surface of a thermoplastic resin film or a stretched film directly or through other layers such as a hard coat layer. The thermoplastic resin film or stretched film with an anti-reflection layer preferably has a reflectance of 2% or less at an incident angle of 5 ° for light having a wavelength of 430 to 700 nm, and more preferably the same reflection at an incident angle for light of a wavelength of 550 nm The rate is 1% or less.

Although the thickness of the antireflection layer may be about 0.01 to 1 μm, it is preferably 0.02 to 0.5 μm. The antireflection layer has a refractive index that is smaller than that of the layer on which it is provided (thermoplastic resin film, stretched film, or hard coat layer, etc.). Specifically, the antireflection layer has a low refractive index having a refractive index of 1.30 to 1.45. The layer may be a low refractive index layer in which a thin film made of an inorganic compound and a high refractive index layer in a thin film made of an inorganic compound are laminated on each other.

The material forming the low refractive index layer is not particularly limited as long as the refractive index is small.

Examples include resin materials such as ultraviolet curable acrylic resins; mixed materials in which inorganic fine particles such as colloidal silica are dispersed in the resin; sol-gel materials containing alkoxysilanes, and the like. Such a low refractive index layer It can be formed by coating a polymer that has been polymerized, or it can be formed by coating in the state of a monomer or oligomer of a precursor, followed by polymerization and hardening. In addition, in order to impart antifouling properties to individual materials, it is preferable to include a compound having a fluorine atom in the molecule.

As a sol-gel material for forming a low-refractive-index layer, it is suitable for those having a fluorine atom in the molecule. A typical example of a sol-gel material having a fluorine atom in the molecule is a polyfluoroalkylalkoxysilane. The polyfluoroalkylalkoxysilane can be, for example, a compound represented by the following formula: CF ₃ (CF ₂ ) _n CH ₂ CH ₂ Si (OR) ₃ , where R represents an alkyl group having 1 to 5 carbon atoms, n represents an integer from 0 to 12. Among them, compounds in which n in the above formula is 2 to 6 are preferred.

Specific examples of the polyfluoroalkylalkoxysilane include the following compounds.

3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3,3,4,4,5,5,6,6,7,7 , 8,8,8-tridecafluorooctyltrimethoxysilane, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyltriethyl Oxysilane, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10,10-heptadecafluorodecyltrimethoxysilane, 3, 3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyltriethoxysilane and the like.

The low refractive index layer may be composed of a cured product of a thermosetting fluorine-containing compound or an active energy ray-curable fluorine-containing compound. This hardened substance, It is preferably within a range of 0.03 to 0.15, and more preferably within a range of 90 to 120 ° with respect to a contact angle with water. As hardenable fluorine-containing compounds, in addition to polyfluoroalkyl groups containing silane compounds (such as 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10 , 10-heptadecafluorodecyltriethoxysilane, etc.), and fluoropolymers having a crosslinkable functional group can be mentioned.

The fluorine-containing polymer having a crosslinkable functional group can be produced by the following method 1) or 2): 1) a method of copolymerizing a fluorine-containing monomer and a monomer having a crosslinkable functional group Or, 2) a method of copolymerizing a fluorine-containing monomer with a monomer having a functional group, and secondly adding a compound having a crosslinkable functional group to the above-mentioned functional group in the polymer.

Examples of the fluorine-containing monomer include, for example, vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxy, etc. Fluoroolefins; partially or fully fluorinated alkyl ester derivatives of (meth) acrylic acid; fully or partially fluorinated vinyl ethers of (meth) acrylic acid.

Examples of the monomer having a crosslinkable functional group or the compound having a crosslinkable functional group include monomers having a glycidyl group such as glycidyl acrylate or glycidyl methacrylate; Or a monomer of a carboxyl group of methacrylic acid; a monomer having a hydroxyl group such as hydroxyalkyl acrylate or hydroxyalkyl methacrylate; a monomer of an alkenyl group such as allyl acrylate or allyl methacrylate Monomers; monomers having amine groups; monomers having sulfonic acid groups.

The material used to form the low refractive index layer can improve the scratch resistance, and can also include silicon dioxide, aluminum oxide, titanium dioxide, oxygen Fine particles of inorganic compounds such as zirconium and magnesium fluoride are dispersed in a sol of an alcohol solvent. From the viewpoint of antireflection, the inorganic compound fine particles used therefor are preferably those having a smaller refractive index. The inorganic compound fine particles may be those having voids, and particularly preferred are silicon dioxide hollow fine particles. The average particle diameter of the hollow fine particles is preferably in a range of 5 to 2000 nm, and particularly preferably in a range of 20 to 100 nm. Here, the average particle diameter means a number average particle diameter obtained by observation with a transmission electron microscope.

(Antifouling layer)

The antifouling layer is provided for imparting water resistance, oil repellency, sweat resistance, stain resistance, and the like. Suitable for forming antifouling layer. Fluorine-containing organic compounds. Examples of the fluorine-containing organic compound include fluorocarbon, perfluorosilane, and polymer compounds thereof. The formation method of the antifouling layer may be a physical vapor growth method, a chemical vapor growth method, a wet coating method, or the like, which are representative examples of vapor deposition or sputtering depending on the material to be formed. The average thickness of the antifouling layer is usually about 1 to 50 nm, and preferably 3 to 35 nm.

(Anti-glare layer)

The anti-glare layer is a layer having a fine uneven shape on the surface, and is preferably formed using the hard coating material described above.

An anti-glare layer having a fine uneven shape on the surface can be produced by the following 1) or 2): 1) forming a coating film containing fine particles on a thermoplastic resin film or a stretched film, and setting the unevenness according to the fine particles Method, 2) Forming a coating film containing fine particles or not containing the thermoplastic resin A method (also referred to as embossing method) or the like for transferring a concave-convex shape by pressing a mold (roller, etc.) for imparting a concave-convex shape to the surface after stretching the film or stretched film.

In the above method 1), a curable resin composition containing a curable transparent resin and fine particles is coated on a thermoplastic resin film or a stretched film, and the coating layer can be hardened by irradiation or heating with light such as ultraviolet rays. To form an anti-glare layer. The curable transparent resin is preferably selected from a material having a high hardness (hard coating). As the curable transparent resin, a photo-curable resin such as an ultraviolet-curable resin, a thermo-curable resin, an electron beam-curable resin, etc. can be used, but from the viewpoints of productivity and hardness of the obtained anti-glare layer, It is preferable to use a photocurable resin, and it is more preferable to use an ultraviolet curable resin. When a photocurable resin is used, the curable resin composition further contains a photopolymerization initiator.

As the photocurable resin, a polyfunctional acrylate is generally used. Specific examples thereof include a tri- or tri-acrylate of trimethylolpropane; a tri- or tetra-acrylate of pentaerythritol; and a polyfunctional product of a reaction product of an acrylate having at least one hydroxyl group and a diisocyanate in the molecule Ethyl urethane acrylate. These polyfunctional acrylates can be used individually or in combination of 2 or more types as needed.

In addition, a mixture of a polyfunctional ethyl urethane acrylate, a polyol (meth) acrylate, and a (meth) acrylfluorene-based polymer having an alkyl group containing two or more hydroxyl groups may be used as the photocuring property. Resin. The polyfunctional ethyl urethane acrylate constituting the photocurable resin is produced using, for example, (meth) acrylic acid and / or (meth) acrylate, a polyol, and a diisocyanate. Specifically, from (meth) acrylic acid and / or (meth) acrylic acid An acrylate and a polyhydric alcohol are prepared as a hydroxy (meth) acrylate having at least one hydroxyl group in the molecule, and by reacting this with a diisocyanate, a polyfunctional urethane acrylate can be produced. The polyfunctional urethane ethyl acrylate produced in this manner becomes the photocurable resin itself disclosed previously. In the production, one type of (meth) acrylic acid and / or (meth) acrylate can be used, and two or more types can be used in combination. The same is true for polyols and diisocyanates, and one type can be used, and two or more types can be combined. use.

The (meth) acrylate to be a raw material of the polyfunctional urethane ethyl acrylate may be a chain or cyclic alkyl ester of (meth) acrylic acid. Specific examples thereof include meth (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and butyl (meth) ) Alkyl (meth) acrylates of acrylates, and cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate.

The polyhydric alcohol which becomes another raw material of the polyfunctional urethane ethyl acrylate is a compound having at least two hydroxyl groups in the molecule. Examples include ethylene glycol, propylene glycol, 1,3-propanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1, 6-hexanediol, 1,9-nonanediol, 1,10-decanediol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl-1 , 5-pentanediol, neopentyl glycol esters of hydroxypivalic acid, cyclohexanedimethylol, 1,4-cyclohexanediol, Spiroglycol, tricyclodecanediol Methylol, hydrogenated bisphenol A, ethylene oxide-added bisphenol A, propylene oxide-added bisphenol A, trimethylolethane, trimethylolpropane, glycerol, 3-methylpentane-1,3 , 5-triol, pentaerythritol, dipentaerythritol, tripentaerythritol, glucose, etc.

Diisocyanate, which is another raw material of polyfunctional urethane ethyl acrylate, is a compound having two isocyanate groups (-NCO) in the molecule. A variety of aromatic, aliphatic, or alicyclic diisocyanates can be used. . Specific examples include tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-methylphenyl diisocyanate, 4,4'-diphenyl diisocyanate, 1 , 5-naphthalene diisocyanate, 3,3'-dimethyl-4,4'-diphenyl diisocyanate, xylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4'-diphenyl Methane diisocyanates and nuclear hydrides of diisocyanates having aromatic rings among these.

The polyhydric alcohol (meth) acrylate constituting the above-mentioned photocurable resin together with the polyfunctional urethane ethyl acrylate is a (meth) group of a compound (that is, a polyhydric alcohol) having at least two hydroxyl groups in the molecule. Acrylate. Specific examples thereof include pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and 1,6-hexane. Glycol di (meth) acrylate and the like. The polyol (meth) acrylate may be used alone or in combination of two or more.

The polyol (meth) acrylate preferably contains pentaerythritol triacrylate and / or pentaerythritol tetraacrylate.

Furthermore, these polyfunctional ethyl urethane acrylates and polyhydric alcohol (meth) acrylates together constitute a photocurable resin, and a (meth) acrylfluorene-based polymer having an alkyl group containing two or more hydroxyl groups In the case of an alkyl group containing two or more hydroxyl groups in one constituent unit. For example Examples include a polymer containing 2,3-dihydroxypropyl (meth) acrylate as a constituent unit, or a polymer containing 2,3-dihydroxypropyl (meth) acrylate, including 2-hydroxyethyl ( Polymers such as meth) acrylates as constituent units.

As mentioned above, the use of (meth) acryl fluorene-based photocurable resin as an example can improve the adhesiveness with a thermoplastic resin film or a stretched film, and improve the mechanical strength. Anti-glare film to prevent surface scratches.

As the fine particles, those having an average particle diameter of 0.5 to 5 μm and a refractive index difference from the hardening transparent resin after curing are preferably 0.02 to 0.2. By using fine particles having an average particle diameter and a refractive index difference within this range, fog can be effectively expressed.

The average particle diameter of the fine particles can be obtained by a dynamic light scattering method or the like. The average particle diameter at this time is taken as a weight average particle diameter.

The fine particles may be organic fine particles or inorganic fine particles. As the organic fine particles, resin particles are generally used, and examples thereof include cross-linked polyacrylic particles, methyl methacrylate / styrene copolymer resin particles, cross-linked polystyrene particles, cross-linked polymethyl methacrylate particles, and silicone resins. Particles, polyimide particles, etc. In addition, as the inorganic fine particles, silica, colloidal silica, alumina, alumina sol, aluminum silicate, alumina-silica dioxide composite oxide, kaolin, talc, mica, calcium carbonate, and calcium phosphate can be used. Wait.

As the photopolymerization initiator, various types such as acetophenone-based, benzophenone-based, benzoin-ether-based, amine-based, and phosphine oxide-based can be used. Minute Examples of compounds that are acetophenone-based photopolymerization initiators include 2,2-dimethoxy-2-phenylacetophenone (also known as benzyldimethylketal) and 2,2-diethyl Oxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-2-morpholine 1- (4-methylthiophenyl) propane-1-one. Examples of compounds classified into benzophenone-based photopolymerization initiators include benzophenone, 4-chlorobenzophenone, and 4,4'-dimethoxybenzophenone. Examples of compounds classified into benzoin ether-based photopolymerization initiators include benzoin methyl ether and benzoin propyl ether. Examples of compounds classified as amine-based photopolymerization initiators include N, N, N ', N'-tetramethyl-4,4'-diaminobenzophenone (alias Michler's ketone). Examples of the phosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzylidene diphenylphosphine oxide. In addition, xanthene-based compounds, xanthones, and the like can also be used as photopolymerization initiators.

These photopolymerization initiators are commercially available. Examples of representative commercially available products are listed under the trade name of "Irgacure 907", "Irgacure 184", "Lucirin TPO", etc. sold by BASF from Germany.

The curable resin composition may contain a solvent if necessary. As the solvent, for example, any organic solvent that can dissolve the components constituting the curable resin composition such as ethyl acetate and butyl acetate can be used. It is also possible to use a mixture of two or more organic solvents.

The curable resin composition may contain a leveling agent, and for example, a fluorine-based or silicone-based leveling agent may be used. Among silicone leveling agents, they are reactive silicone, polydimethylsiloxane, polyether modified polydimethylsiloxane, polymethylalkylsiloxane, and the like. Among the silicone-based leveling agents, a reactive silicone and a siloxane-based leveling agent are preferred. If using reactive silicone A leveling agent, which imparts smoothness to the surface of the anti-glare layer, and can make it excellent in scratch resistance for a long period of time. In addition, when a siloxane-based leveling agent is used, the film formability can be improved.

In addition, when the anti-glare layer having a fine surface unevenness is formed by the method (imprint method) of the above 2), the shape of the mold is transferred to a thermoplastic resin film or a stretched film using a mold that forms a fine uneven shape. The resin layer is sufficient. When a fine surface uneven shape is formed by an imprint method, the resin layer to which the uneven shape is transferred may or may not contain fine particles. The resin constituting the resin layer is preferably a photocurable resin as exemplified in the method 1), and more preferably an ultraviolet curable resin. However, instead of the ultraviolet curable resin, by appropriately selecting a photopolymerization initiator, a visible light curable resin that can be cured by visible light having a longer wavelength than the ultraviolet light can also be used.

In the embossing method, a curable resin composition containing a photocurable resin such as an ultraviolet curable resin is coated on a (meth) acrylic resin film, and the coating is laminated to the unevenness of a mold while being coated. The surface side is hardened, and the uneven surface of the mold is transferred to the coating layer. More specifically, a curable resin composition is applied to a (meth) acrylic resin film so that the coating layer is in close contact with the uneven surface of the mold, and the (meth) acrylic resin film is irradiated. Light such as ultraviolet rays to harden the coating layer. Second, the (meth) acrylic resin film having the cured coating layer (anti-glare layer) is peeled from the mold to transfer the uneven shape of the mold. To the anti-glare layer.

Although the thickness of the anti-glare layer is not particularly limited, it is generally 2 to 30 μm, preferably 3 μm or more, and more preferably 20 μm or less. Anti-glare layer When it is thin, sufficient hardness cannot be obtained, and the surface tends to be scratched. When it is too thick, it tends to crack or the film curls due to the hardening shrinkage of the anti-glare layer, which tends to reduce productivity.

The haze value of the thermoplastic resin film or stretched film having an anti-glare layer is preferably in the range of 5 to 50%. When the haze value is too small, sufficient anti-glare performance cannot be obtained. When a polarizing plate having a thermoplastic resin film or a stretched film with an anti-glare layer is applied to an image display device, the screen is prone to reflect external light. In addition, when the fog value is too large, although the reflection of external light can be reduced, the interference of the black display screen is reduced. The haze value is a ratio of the diffusive transmittance to the total light transmittance, and is measured in accordance with JIS K 7136: 2000 "A method for determining a haze value of a plastic-transparent material".

<Polarizer>

On the surface of at least one side of the polarizer, a thermoplastic resin film or a stretched film can be disposed as a polarizer protective film and used as a polarizer. The polarizing plate includes a polarizer and a polarizer-protecting film disposed on a surface of at least one side of the polarizer. The polarizer protection film and the polarizer are preferably bonded together.

The polarizer can be a step of stretching a polyvinyl alcohol-based thermoplastic resin film through a uniaxial method according to a known method, and a step of dyeing the polyvinyl alcohol-based thermoplastic resin film with a dichroic dye to adsorb the dichroic dye. (5) A step of treating a polyvinyl alcohol-based thermoplastic resin film that adsorbs a dichroic dye with a boric acid aqueous solution, and a step of washing with a boric acid aqueous solution after treatment. The polarized photon obtained in this way becomes a person having an absorption axis in the aforementioned direction of uniaxial stretching.

As the polyvinyl alcohol-based resin, a saponified polyvinyl acetate-based resin can be used. Examples of the polyvinyl acetate-based resin include copolymers of vinyl acetate and other monomers copolymerizable therewith, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The saponification degree of the polyvinyl alcohol-based resin is preferably 85 to 100 mol%, and more preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified. For example, polyvinyl aldehyde or polyvinyl acetal modified with aldehydes may be used. The polymerization degree of the polyvinyl alcohol-based resin is preferably 1,000 to 10,000, and more preferably 1500 to 5,000.

Those who make such a polyvinyl alcohol-based resin are used as a polarizing film. The method of forming a polyvinyl alcohol-type resin is not specifically limited, A well-known method is used. The thickness of the polyvinyl alcohol-based primary and reverse film is preferably 10 to 150 μm.

The uniaxial stretching of the polyvinyl alcohol-based thermoplastic resin film can be performed before, simultaneously with, or after dyeing with a dichroic pigment. When a uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before or during a boric acid treatment. It is also possible to perform uniaxial stretching in these plural stages.

Uniaxial stretching can be performed by passing through spaced rollers with different peripheral speeds, or by holding by hot rollers. In addition, this uniaxial stretching may be dry stretching in the air, and may be a polyvinyl alcohol-based thermoplastic resin film using a solvent such as water or an organic solvent to swell it. In this state, wet stretching is performed. The stretching ratio is preferably 3 to 8 times.

Dyeing of the dichroic dye of the polyvinyl alcohol-based thermoplastic resin film can be performed, for example, by immersing the polyvinyl alcohol-based thermoplastic resin film in an aqueous solution containing the dichroic dye. As the dichroic dye, iodine or a dichroic organic dye is used. In the polyvinyl alcohol-based thermoplastic resin film, it is preferable to perform a dipping treatment with water before the dyeing treatment.

When using iodine as a dichroic dye, a method of dyeing by dipping a polyvinyl alcohol-based thermoplastic resin film in an aqueous solution containing iodine and potassium iodide is generally used. The content of iodine in this aqueous solution is preferably 0.01 to 1 part by weight per 100 parts by weight of water, and the content of potassium iodide is preferably 0.5 to 20 parts by weight per 100 parts by weight of water. The temperature of the aqueous solution used for dyeing is preferably 20 to 40 ° C. The immersion time (dyeing time) of the aqueous solution is preferably 20 to 1800 seconds.

When a dichroic organic dye is used as the dichroic dye, a method of dipping a polyvinyl alcohol-based thermoplastic resin film in an aqueous solution containing a water-soluble dichroic organic dye is generally used. The content of the dichroic organic dye in this aqueous solution is preferably 0.0001 to 10 parts by weight, more preferably 0.001 to 1 part by weight per 100 parts by weight of water. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the dichroic dye aqueous solution used for dyeing is preferably 20 to 80 ° C. The immersion time (dyeing time) of the aqueous solution is preferably 10 to 1800 seconds.

By the boric acid treatment after the dichroic dye is dyed, the dyed polyvinyl alcohol-based thermoplastic resin film can be dipped in the boric acid-containing Aqueous solution. The amount of boric acid in the boric acid-containing aqueous solution is preferably 2 to 15 parts by weight per 100 parts by weight of water; more preferably 5 to 12 parts by weight. When iodine is used as the dichroic dye, the boric acid-containing aqueous solution preferably contains potassium iodide. The amount of potassium iodide in the boric acid-containing aqueous solution is preferably 0.1 to 15 parts by weight, and more preferably 5 to 12 parts by weight per 100 parts by weight of water. The immersion time of the aqueous solution containing boric acid is preferably 60 to 1200 seconds, more preferably 150 to 600 seconds, and even more preferably 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is preferably 50 ° C or higher, more preferably 50 to 85 ° C, and even more preferably 60 to 80 ° C.

The polyvinyl alcohol-based thermoplastic resin film after the boric acid treatment is usually subjected to water washing treatment. The water washing treatment is performed, for example, by immersing a boric acid-treated polyvinyl alcohol-based thermoplastic resin film in water. The temperature of the water in the water washing treatment is preferably 5 to 40 ° C. The immersion time is preferably 1 to 120 seconds.

After washing with water, a drying process is performed to obtain polarized photons. The drying process can be performed using a hot-air dryer or a far-infrared heater. The temperature of the drying treatment is preferably 30 to 100 ° C, and more preferably 50 to 80 ° C. The drying time is preferably 60 to 600 seconds, and more preferably 120 to 600 seconds.

By drying, the moisture content of polarized photons is reduced to a practical level. The moisture content is preferably 5 to 20% by weight, and more preferably 8 to 15% by weight. When the moisture content is less than 5% by weight, the flexibility of the polarized photon may be lost, and the polarized photon may be damaged or broken after drying. When the moisture content exceeds 20% by weight, the thermal stability of the polarized photon may be insufficient.

The polyvinyl alcohol-based thermoplastic resin thin film thus obtained The thickness of the polarized photon formed by adsorbing and aligning the dichroic dye on the film is preferably 5 to 40 μm.

When a polarizer protective film is arranged on the surface on one side of the polarizer, a transparent thermoplastic resin film may be arranged on the other side. The transparent thermoplastic resin film and the polarizer are the same as those in the case of the polarizer protective film and the polarizer, and are preferably bonded together. Examples of the transparent thermoplastic resin film include a triethylfluorene-based cellulose film, a polycarbonate film, a polyethylene terephthalate film, an acrylic fluorene-based thermoplastic resin film, an acrylic resin, and a polycarbonate resin. Laminated films, olefin-based thermoplastic resin films, and the like.

It is preferable to use an adhesive for the bonding of the polarizer protective film and the polarizer and the bonding of the polarizer and the transparent thermoplastic resin film. By using an adhesive, the polarizer protection film and the polarizer, and the polarizer and the transparent thermoplastic resin film are connected and bonded through the adhesive layer.

In addition, it is preferable to perform a corona discharge treatment, a plasma irradiation treatment, an electron beam irradiation treatment, and other surface activation treatments on at least one side of the bonding surface before bonding.

The adhesive used to form the adhesive layer can be used arbitrarily because it exhibits adhesion to individual components. In general, an aqueous adhesive is mentioned, that is, an active energy ray-curable adhesive that dissolves the adhesive component in water or disperses the adhesive component in water, or an active energy ray-curable adhesive including a component that is hardened by irradiation with active energy ray. Among them, an active energy ray-curable adhesive is preferred from the viewpoint of productivity.

Examples of the water-based adhesive include the use of polyvinyl alcohol. A composition based on a resin or urethane resin as a main component is a preferable adhesive.

When a polyvinyl alcohol-based resin is used as a main component of the water-based adhesive, examples of the polyvinyl alcohol-based resin include, in addition to partially saponified polyvinyl alcohol or fully saponified polyvinyl alcohol, such as carboxyl-modified polyvinyl alcohol and acetamidine Modified polyvinyl alcohol resins of acetamyl modified polyvinyl alcohol, methylol modified polyvinyl alcohol, and amino modified polyvinyl alcohol. When a polyvinyl alcohol-based resin is used as the adhesive component, many of the adhesives are prepared as an aqueous solution of the polyvinyl alcohol-based resin. The concentration of the polyvinyl alcohol-based resin in the aqueous adhesive solution is preferably 1 to 10 parts by weight, and more preferably 1 to 5 parts by weight with respect to 100 parts by weight of water.

In the water-based adhesive containing a polyvinyl alcohol-based resin as a main component, it is preferable to add a hardening component such as glyoxal or a water-soluble epoxy resin or a cross-linking agent in order to improve adhesion. Examples of the water-soluble epoxy resin include polyamine polyamines obtained by reacting a polyalkylene polyamine such as diethylenetriamine or triethylenetetramine with a dicarboxylic acid such as adipic acid to make epichlorohydrin. Polyamine polyamine epoxy resin obtained by the reaction of alcohol (Epichlorohydrin). As the polyamide polyamine epoxy resin, commercially available products can be used, and examples thereof include "Sumirez resin 650" and "Sumirez resin 675" manufactured by Sumika Chemtex Co., Ltd., and "WS-525" manufactured by Japan PMC Co., Ltd. . The addition amount of these hardenable components or crosslinking agents is preferably 1 to 100 parts by weight, and more preferably 1 to 50 parts by weight based on 100 parts by weight of the polyvinyl alcohol resin. When the addition amount is small, the adhesion improving effect is reduced, and when the addition amount is large, the adhesive layer may become brittle in some cases.

When an urethane resin is used as the main component of the water-based adhesive, examples of suitable adhesive compositions include polyester-based ionic polymer urethane resins and compounds having a glycidyloxy group. mixture. The polyester-based ionic polymer type urethane resin here refers to a urethane resin having a polyester skeleton, and a small amount of an ionic component (hydrophilic component) is introduced therein. The ionic polymer type urethane resin is preferably used as an aqueous adhesive because it is emulsified directly in water without using an emulsifier to become an emulsion.

When an activated energy ray-curable adhesive is used, as a component which is hardened by irradiation of an active energy ray constituting it (hereinafter sometimes simply referred to as a "curable component"), an epoxy compound, propylene oxide ( Oxetane) compounds, acryl fluorenyl compounds, and the like. When an cationically polymerizable compound such as an epoxy compound or an oxetane compound is used, a cationic polymerization initiator is added. When a radical polymerizable compound such as an acrylamide-based compound is used, a radical polymerization initiator is blended. Among them, an adhesive agent using an epoxy compound as one of the hardening components is preferred, and an adhesive agent using an alicyclic epoxy compound based on a saturated carbocyclic ring as the hardening component is more preferred. In addition, a propylene oxide (Oxetane) compound may be used in combination.

As the epoxy compound, commercially available products can be used, and examples thereof include "Epicoat" series manufactured by Japan Epoxy Resin Co., Ltd., "Epiclon" series manufactured by DIC Co., Ltd., and "EPOTOHTO" series manufactured by Tohto Kasei Co., Ltd. "ADEKA RESIN" series made by ADEKA Co., Ltd., made by Nagase Chemtex Co., Ltd. "Denacol" series, "The Dow Epoxy" series manufactured by The Dow Chemical Company, "TEPIC" manufactured by Nissan Chemical Industry Co., Ltd., etc.

As the alicyclic epoxy compound based on a saturated carbocyclic ring of the direct-bonding epoxy, commercially available products can be used, and examples thereof include the "CELLOXIDE" series and "CYCLOMER" series manufactured by Daicel Chemical Industry Co., Ltd., and manufactured by The Dow Chemical Company. "CYRACURE" series, etc.

As the propylene oxide (Oxetane) compound, commercially available products can be used, and examples thereof include "Aron Oxetane" series manufactured by Toa Synthesis Co., Ltd., and "ETERNACOLL" series manufactured by Ube Industries Co., Ltd.

Commercially available products can be used as the cationic polymerization initiator. Examples include the "KAYARAD" series manufactured by Nippon Kayaku Co., Ltd., the "CYRACURE" series manufactured by Union Carbide, and the photoacid generator manufactured by San Apro Co., Ltd. "CPI" series, "TAZ", "BBI" and "DTS" of photoacid generators manufactured by Green Chemical Co., Ltd., "Adekaoptomer" series manufactured by ADEKA Co., Ltd., and "RHODORSIL" series manufactured by Rhodia Corporation .

The active energy ray-curable adhesive may contain a photosensitizer if necessary. By using a photosensitizer, the reactivity is improved, and the mechanical strength or adhesion strength of the hardened layer is improved. Examples of the photosensitizer include a carbonyl compound, an organic sulfur compound, a persulfide, a redox compound, an azo and diazo compound, an onion compound, a halogen compound, and a photoreductive dye.

In active energy ray hardening adhesive, it does not damage its connection Various additives can be blended in the range of adhesion. Examples of the additives include ion trapping agents, antioxidants, chain transfer agents, adhesion-imparting agents, thermoplastic resins, fillers, flow regulators, plasticizers, and defoamers. Furthermore, in the range which does not impair its adhesivity, a hardening component hardened by other reaction mechanisms may be blended with cation polymerization.

Although the active energy ray-curable adhesives described above may have the same composition or different compositions, the irradiation of the active energy rays to harden both is preferably performed simultaneously.

Examples of the active energy rays include X-rays, ultraviolet rays, and visible rays. Among these, from the viewpoints of ease of use and ease of preparation of active energy ray-curable adhesive, stability, and curing performance, ultraviolet rays are preferred. Examples of the ultraviolet light source include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, and a metal halide lamp.

The thickness of the adhesive layer obtained by using the active energy ray-curable adhesive is preferably 1 to 50 μm, and more preferably 1 to 10 μm.

The polarizing plate is bonded to a liquid crystal cell, and can be used as a liquid crystal panel for a liquid crystal display device. The polarizing plate and the liquid crystal cell are preferably adhered through an adhesive layer using an adhesive. This adhesive layer uses acrylate as a main component, and is generally formed by copolymerizing an acrylic resin having a functional group containing acrylfluorene-based monomer and acrylfluorene-based adhesive as an adhesive component. A liquid crystal panel formed on a liquid crystal cell by bonding a polarizing plate through an adhesive layer can be used in a liquid crystal display device.

[Example]

Hereinafter, although the present invention will be specifically described with examples and comparative examples, the present invention is not limited to these examples.

Various physical properties of the obtained resin composition were measured and evaluated by the following methods.

<Glass transition temperature (Tg)>

The intermediate glass transition intermediate temperature measured by differential scanning calorimetry operation heating rate of 10 ° C / min in accordance with JIS K7121: 1987 is used as the glass transition temperature (Tg).

<Shear viscosity becomes 2500Pa. Temperature of s (T ₂₅₀₀ )>

Capirograph (manufactured by Toyo Seiki Seisakusho Co., Ltd., barrel radius: 9.55mm L / D of the capillary: 10), the shearing speed is fixed at 60sec ^-1 , the shearing viscosity at each temperature is measured, and the relationship between the shearing viscosity and the temperature is obtained. From this relationship, the shearing speed at 60sec is calculated. The shear viscosity of the resin composition of ^-1 becomes 2500Pa. The temperature of s is T ₂₅₀₀ . However, the relational expression is a formula that approximates the measurement result to an exponential function, and the least square method is used to calculate the formula.

(Synthesis example 1: Synthesis of acrylic resin)

As shown in Table 1, monomer components of 79.0% by weight of methyl methacrylate (MMA), 20.0% by weight of cyclohexyl methacrylate (CHMA), and 1.0% by weight of methyl acrylate (MA) were obtained. In this monomer composition, phase For 100 parts by weight of the monomer component, 0.2 parts by weight of lauryl peroxide is added as a polymerization initiator, and 0.50 parts by weight of 1-dodecyl mercaptan is added as a chain transfer agent with respect to 100 parts by weight of the monomer component. A monomer mixture obtained by dissolving these was obtained. In addition, 0.05 parts by weight of sodium polyacrylate was added as a suspension stabilizer to 100 parts by weight of ion-exchanged water, and 0.24 parts by weight of anhydrous first sodium phosphate was added with 100 parts by weight of ion-exchanged water, and 100 parts by weight of ion-exchanged water Part by weight, 0.28 part by weight of the second sodium phosphate 7 hydrate was added to ion-exchanged water to obtain a suspension polymerization aqueous phase in which these were dissolved. Next, 150 parts by weight of the suspension polymerization aqueous phase was added to 100 parts by weight of the monomer component to the monomer mixture to perform suspension polymerization. The obtained slurry-like reaction solution was dehydrated and washed with a dehydrator, and then dried to obtain a bead-like acrylic resin. About the obtained acrylic resin, GPC measurement was performed, and the weight average molecular weight (Mw) calculated | required by polymethylmethacrylate conversion is shown in Table 1.

(Synthesis Examples 2 to 3: Synthesis of acrylic resin)

A granular acrylic resin was obtained in the same procedure as in Synthesis Example 1 except that the components described in Table 1 were used at the ratios described in Table 1. The weight average molecular weight (Mw) of the obtained acrylic resin is shown in Table 1.

Table 2 shows the weight average molecular weight (Mw) and MVR of the polycarbonate resin (PC) used. All of these are polycarbonates manufactured by Sumika Stellon Polycarbonate. Hereinafter, as described in Table 2, if it is Caliber301-40, such as PC-40, the description may be omitted. About the obtained polycarbonate resin, GPC measurement was performed, and the weight average molecular weight (Mw) calculated | required by polystyrene conversion is shown in Table 2.

(Example 1: Preparation of resin composition)

As shown in Table 3, 70 parts by weight of the acrylic resin obtained in Synthesis Example 1 and 30 parts by weight of the polycarbonate resin (PC-15) were mixed, and a biaxial kneading extruder (manufactured by Japan Steel Works Co., Ltd.) was used. , TEX-30SS, the ratio of the length (L) of the screw to the diameter (D) of the screw (L / D) is 41), melt-kneading at a cylinder temperature of 250 ° C and a number of revolutions of 100 rpm. The melt was extruded into strands, and after cooling, the strands were cut with a strand cutter to obtain a granular resin composition. With respect to the obtained resin composition, Tg and T ₂₅₀₀ were obtained. For the obtained resin composition, a value of "(1.5 × MVR _PC × W _a × W _a ) / (W _b × W _b ) +245" was calculated. The results are shown in Table 3.

(Examples 2 to 5 and Comparative Example 1: Preparation of resin composition)

Except that the components described in Table 3 were used in the proportions described in Table 3, the same procedures as in Example 1 were used to obtain granular resin compositions. With respect to the obtained resin composition, Tg and T ₂₅₀₀ were obtained. For the obtained resin composition, a value of "(1.5 × MVR _PC × W _a × W _a ) / (W _b × W _b ) +245" was calculated. The results are shown in Table 3.

(Examples 1 to 5 and Comparative Example 1: Production of a thermoplastic resin film)

Each obtained resin composition was melt-kneaded in a uniaxial extruder with a screw diameter of 65 mm and a vent hole, and the molten resin was supplied to a T die. The temperature of the T mold was the T mold temperature described in Table 4 and a value that did not exceed the calculation result of the resin composition described in Table 3 (except for Comparative Example 1).

Next, the supplied molten resin is continuously extruded from the T die into a film shape, and further, the thin film-shaped molten resin continuously extruded from the T die is held on a smooth metal by a pair of surfaces. Between rollers Forming. After cooling, a thermoplastic resin film having a thickness of 120 m was obtained. About the obtained thermoplastic resin film, the total light transmittance (Tt) was measured by the following method. The results are shown in Table 4.

<Total light transmittance (Tt)>

The total light transmittance (Tt) was measured using a transmittance meter (HR-100, manufactured by Murakami Color Technology Research Institute) in accordance with JIS K7361-1.

(Examples 1 to 5 and Comparative Example 1: Production of a biaxially stretched film)

Each obtained thermoplastic resin film was biaxially stretched. First, each thermoplastic resin film is longitudinally stretched between two sets of squeeze roller pairs provided before and after each of the hot air circulation furnaces. The furnace can be divided into 4 areas at 1m intervals for temperature setting, the first area on the inlet side is set to room temperature, the second area is set to the same temperature as the Tg of each resin composition, and the third area is set to the next The fourth area on the mouth side of the outlet mouth is set to a temperature 10 ° C higher than Tg. By setting the speed of the film passing through the squeeze roller on the entrance side to 2 mm / min and the speed of the film passing through the squeeze roller on the exit side of the nozzle to 4.4 mm / min, a stretch ratio of 2.2 in the longitudinal direction was made Times as long as a longitudinally stretched film.

Next, the produced longitudinally stretched film was cut into a length of 1 m in the longitudinal direction, and a longitudinally stretched film having a length of 1 m in the longitudinal direction was obtained. The longitudinally stretched film having a length of 1 m in the longitudinal direction was introduced into a tenter. A horizontal stretching machine performs horizontal stretching. The transverse stretching is performed in a hot-air circulating furnace with a length of 4 m, and the temperature in the furnace is set to a temperature 10 ° C higher than the Tg. Set the speed through the furnace It was 1 mm / min, and the draw ratio was set to 2 times. As described above, a biaxially stretched film having a stretching ratio of 2.2 times in the longitudinal direction, a stretching ratio of 2 times in the transverse direction, and a thickness of 40 μm was obtained. About the obtained biaxially stretched film, the high-temperature tensile elastic modulus was measured by the following method. The results are shown in Table 4.

<High-temperature tensile elastic modulus>

Each biaxially stretched film was subjected to a tensile test at 80 ° C, and the high-temperature tensile elastic modulus was measured. A biaxially stretched film was taken with a longitudinal stretching direction as a long side, a rectangle of 120 mm in the longitudinal direction and 25 mm in the transverse direction was cut out, the distance between the chucks was set to 90 mm, and a tensile test was performed at a stretching speed of 5 mm / min in the longitudinal direction. The high-temperature tensile elastic modulus was calculated from the slope of the stress-strain curve in the region where the tensile strength was from 3 MPa to 6 MPa. The higher the high-temperature tensile elastic modulus, the more difficult it is to shrink in a high-temperature environment.

(Preparation of hardening paint)

25 parts of dipentaerythritol hexaacrylate [NK ester A-DPH manufactured by Shin Nakamura Chemical Industry Co., Ltd.], 2 parts of photoinitiator [IRGACURE 184 manufactured by Ciba Specialty Chemicals Co., Ltd.], 5 parts Antimony oxide fine particle sol [ELCOM V-4514 manufactured by Catalytic Chemical Industries, Ltd .; solid content concentration 20%] 10 parts, 1 part of 1-methoxy-2-propanol, 24 parts of isobutyl alcohol And 15 parts of diacetone alcohol to prepare a hardening coating.

(Examples 1 to 5 and Comparative Example 1: Production of Hard Coated Film)

Each of the obtained biaxially stretched films was cut into a size of 300 mm × 200 mm, and a coating film of a hardening paint was formed on one surface by a bar coating method. Next, it was dried at room temperature for 1 minute, and then dried in a hot air oven at 50 ° C for 3 minutes. After the solvent was volatilized, a 120 W high-pressure mercury lamp was applied to the coating film, and 0.5 J / cm ² of ultraviolet light was used to harden it. On the side surface, a hard-coated film including a thermoplastic resin film having a hard-coat layer having a thickness of 3.5 μm was obtained. About the obtained hard coating film, the toughness was evaluated by the following method. The results are shown in Table 4.

<Folding and Cracking Resistance>

In order to evaluate the toughness of the hard coating film, a folding crack resistance test was performed. The obtained hard-coated film was folded with a finger with the surface on which the hardened film was formed as an outer side, and it was judged that the hard-coated film was not cracked as ○, and the case where the hard-coated film was cracked as x.

Claims (11)

A thermoplastic resin film is a thermoplastic resin film composed of a resin composition in which an acrylic resin and a polycarbonate resin are 100% by weight relative to the total, and the acrylic resin is 50% It is contained in a proportion of ~ 95% by weight and a polycarbonate resin in an amount of 5 to 50% by weight, and is characterized in that the acrylic resin is a resin containing a copolymer obtained by polymerizing a monomer component. 100% by weight of the total body composition, 50 to 90% by weight of methyl methacrylate, 5 to 50% by weight of (meth) acrylate represented by the following formula (I), and other monofunctional monomers The body is composed of 0.1 to 20% by weight, (Wherein R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group substituted with a cycloalkyl group, a cycloalkyl group, a cycloalkyl group substituted with an alkyl group, an alkyl group substituted with a naphthyl group, and naphthalene group to the alkyl group substituted with a naphthyl group, substituted in the phenyl group, a phenyl group, the phenyl group substituted with an alkyl, dicyclopentadiene or dicyclopentenyl group); at shear rate of 60sec ^- The shear viscosity of the resin composition of ¹ becomes 2500Pa. The temperature T ₂₅₀₀ (℃) satisfies the following formula (a) T ₂₅₀₀ <(1.5 × MVR _PC × W _a × W _a ) / (W _b × W _b ) +245 (a) (where MVR _PC represents the melt volume ratio of a polycarbonate-based resin at 300 ° C, W _a represents the weight% of the (meth) acrylate represented by the formula (I) in the monomer component, and W _b represents the resin composition (% By weight of polycarbonate resin). The thermoplastic resin film according to claim 1, wherein the weight average molecular weight of the acrylic resin is 50,000 to 200,000. The thermoplastic resin film according to claim 1 or 2, wherein (meth) acrylate represented by the formula (I) is cyclohexyl methacrylate, phenyl methacrylate, naphthyl methacrylate, and bicyclic methacrylate At least one selected from the group consisting of amyl ester and dicyclopentenyl methacrylate. The thermoplastic resin film according to claim 1 or 2, wherein at least one selected from the group consisting of monofunctional monosystem methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. The thermoplastic resin film as claimed in claim 1 or 2 is produced by melt coextrusion. The thermoplastic resin film according to claim 1 or 2, wherein the surface is provided with a surface treatment layer on at least one side. A stretched film obtained by stretching the thermoplastic resin film according to any one of claims 1 to 5. The stretched film according to claim 7, wherein the surface is provided with a surface treatment layer on at least one side. A polarizer protection film is composed of a thermoplastic resin film according to any one of claims 1 to 6. A polarizer protective film is composed of a stretched film as claimed in claim 7 or 8. A polarizing plate comprising a polarizer and a polarizer protective film as claimed in claim 9 or 10 disposed on a surface of at least one side of the polarizer.