JP6398426B2 - Resin composition - Google Patents

Description

  The present invention relates to a resin composition.

As a resin that is excellent in transparency and can be used for an optical material, a resin composition of an acrylic resin and a polycarbonate resin is known. For example, Patent Documents 1 and 2 disclose a resin composition of an acrylic resin and a polycarbonate resin as a resin composition that can be used for an optical material.
However, the optical materials obtained from the resin compositions disclosed in these Patent Documents 1 and 2 are not sufficiently low in phase difference and have low impact resistance.

JP-A-5-32846 Japanese Unexamined Patent Publication No. 2011-157412

  There has been a demand for a resin composition for obtaining an optical material having a sufficiently low phase difference and excellent impact resistance.

The present invention includes the following inventions.
[1] A resin composition comprising an acrylic resin, a polycarbonate resin, and rubber elastic particles,
The resin composition whose product of content of the said polycarbonate-type resin and content of the said rubber elastic body particle | grain with respect to 100 mass parts of said resin compositions is 1-120.
[2] The resin composition according to [1], wherein the content of the polycarbonate-based resin is 0.1 to 10 parts by mass with respect to 100 parts by mass of the resin composition.
[3] The resin composition according to [1] or [2], wherein the content of the rubber elastic body particles is 0.1 to 30 parts by mass with respect to 100 parts by mass of the resin composition.
[4] The resin composition according to any one of [1] to [3], wherein the polycarbonate-based resin has a viscosity average molecular weight of 5000 to 20000.
[5] The resin composition according to any one of [1] to [4], wherein the rubber elastic body particles include an acrylic elastic polymer.
[6] The acrylic resin is a homopolymer of methacrylic acid ester or a copolymer of methacrylic acid ester and a monomer other than methacrylic acid ester. The resin composition as described.
[7] The resin composition according to [6], wherein the monomer other than the methacrylic acid ester is an acrylic acid ester.
[8] A method for producing the resin composition according to any one of [1] to [7],
The method for producing a resin composition according to any one of [1] to [7], wherein an acrylic resin, a polycarbonate resin, and rubber elastic particles are melt-kneaded.
[9] An optical material comprising the resin composition according to any one of [1] to [7].
[10] An optical film comprising the resin composition according to any one of [1] to [7].
[11] An optical film obtained by extrusion molding the resin composition according to any one of [1] to [7].
[12] The optical film according to [10] or [11], wherein the thickness is 20 μm to 200 μm.
[13] A polarizing plate having the optical film according to any one of [10] to [12] on at least one surface of the polarizing film.
[14] A polarizing plate having the optical film according to any one of [10] to [12] on one surface of the polarizing film and having a protective film different from the optical film on the other surface.

  With the resin composition of the present invention, an optical material having a sufficiently low retardation and excellent impact resistance can be obtained.

  The resin composition of the present invention (hereinafter sometimes referred to as the present resin composition) contains an acrylic resin, a polycarbonate resin, and rubber elastic particles.

<Acrylic resin>
The acrylic resin contained in the resin composition is, for example, a polymer obtained by polymerizing an acrylic monomer. Examples of the acrylic monomer include (meth) acrylic acid and (meth) acrylic acid ester. The acrylic resin may be a homopolymer (homopolymer) obtained by polymerizing a single acrylic monomer, or a copolymer obtained by copolymerizing two or more acrylic monomers. Alternatively, it may be a copolymer of 50% by mass or more of acrylic monomer and 50% by mass or less of other monomers. In the present specification, the terms “acryl” and “methacryl” may be collectively referred to as “(meth) acryl”.

  Examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, Isobutyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, (meta Alkyl) (meth) acrylates such as isononyl acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, n-amyl (meth) acrylate, isoamyl (meth) acrylate, and lauryl (meth) acrylate Esters, methoxyethyl (meth) acrylate, and ethoxyethyl (meth) acrylate Etc., and the like. Among these, (meth) acrylic acid alkyl ester is preferable, (meth) acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms is more preferable, and methyl (meth) acrylate is more preferable.

  Other monomers include aromatic vinyl monomers, unsaturated nitriles, ethylenically unsaturated carboxylic acid hydroxyalkyl esters, ethylenically unsaturated carboxylic acid amides, ethylenically unsaturated acids other than acrylic acid and methacrylic acid, ethylenic Examples thereof include unsaturated sulfonic acid esters, ethylenically unsaturated alcohols and esters thereof, ethylenically unsaturated ethers, ethylenically unsaturated amines, ethylenically unsaturated silane compounds, and aliphatic conjugated dienes.

  Examples of the aromatic vinyl monomer include styrene, vinyl toluene, and α-methylstyrene.

  Examples of the unsaturated nitrile include acrylonitrile, α-chloroacrylonitrile, α-methoxyacrylonitrile, methacrylonitrile, and vinylidene cyanide.

  Examples of the ethylenically unsaturated carboxylic acid hydroxyalkyl ester include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate.

  Examples of the ethylenically unsaturated carboxylic acid amide include (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-butoxyethyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide, Nn-propoxymethyl ( Examples include meth) acrylamide, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, and N-diethyl (meth) acrylamide.

  Examples of ethylenically unsaturated acids other than (meth) acrylic acid include itaconic acid, fumaric acid, fumaric anhydride, maleic acid, maleic anhydride, vinylsulfonic acid, and ethylenically unsaturated carboxylic acids such as isoprenesulfonic acid, and And ethylenically unsaturated sulfonic acid. The ethylenically unsaturated acid monomer may be neutralized with an alkali metal such as sodium or potassium, or ammonia.

  Examples of the ethylenically unsaturated sulfonate include alkyl vinyl sulfonate and alkyl isoprene sulfonate.

  Examples of the ethylenically unsaturated alcohol include allyl alcohol and methallyl alcohol. Ethylenically unsaturated alcohol esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl stearate, vinyl benzoate, allyl acetate, methallyl caproate, allyl laurate, allyl benzoate, vinyl alkyl sulfonate, alkyl sulfone. Examples include allyl acid and vinyl arylsulfonate.

  Examples of the ethylenically unsaturated ether include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, methyl allyl ether, and ethyl allyl ether.

  Examples of the ethylenically unsaturated amine include vinyldimethylamine, vinyldiethylamine, vinyldiphenylamine, allyldimethylamine, and methallyldiethylamine.

  Examples of the ethylenically unsaturated silane compound include vinyltriethylsilane, methylvinyldichlorosilane, dimethylallylchlorosilane, and vinyltrichlorosilane.

  Aliphatic conjugated dienes include 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-neopentyl-1,3-butadiene, and 2-chloro-1. , 3-butadiene, 1,2-dichloro-1,3-butadiene, 2,3-dichloro-1,3-butadiene, 2-bromo-1,3-butadiene, 2-cyano-1,3-butadiene, direct substitution Examples thereof include chain conjugated pentadienes, linear and side chain conjugated hexadienes, and the like.

(Methacrylic resin)
As the acrylic resin, a methacrylic resin is preferably used from the viewpoint of providing a resin composition for optical materials having excellent hardness, weather resistance, transparency, and the like. A methacrylic resin is a polymer obtained by polymerizing a monomer mainly composed of a methacrylic acid ester. For example, a polyalkyl methacrylate that is a homopolymer of a methacrylic acid ester, a copolymer of two or more methacrylic acid esters. Examples thereof include a copolymer, a copolymer of 50% by mass or more of a methacrylic acid ester and another monomer other than 50% by mass of a methacrylic acid ester, and the like.
In the case of a copolymer of a methacrylic acid ester and another monomer other than the methacrylic acid ester, the methacrylic acid ester is usually 99.9% by mass or less based on the total amount of the monomers, and other single amounts other than this. The body is 0.1% by mass or more, preferably 70% by mass or more of methacrylic acid ester, 30% by mass or less of other monomers, more preferably 90% by mass or more of methacrylic acid ester, The weight is 10% by mass or less.

  Examples of the methacrylic acid ester used for the methacrylic resin include the above-mentioned methacrylic acid esters, and methacrylic acid alkyl esters are preferably used.

  As monomers other than methacrylic acid ester, for example, acrylic acid ester, aromatic vinyl monomer, unsaturated nitrile, ethylenically unsaturated carboxylic acid hydroxyalkyl ester, ethylenically unsaturated carboxylic acid amide, ethylenically unsaturated Examples include acids, ethylenically unsaturated sulfonic acid esters, ethylenically unsaturated alcohols and esters thereof, ethylenically unsaturated ethers, ethylenically unsaturated amines, ethylenically unsaturated silane compounds, and aliphatic conjugated dienes. Among these, acrylic acid esters are preferable. Monomers other than methacrylic acid esters may be used alone or in combination of two or more.

Examples of the acrylic ester used in the methacrylic resin include the above acrylic esters, and alkyl acrylates are preferably used.
Aromatic vinyl monomer, unsaturated nitrile, ethylenically unsaturated carboxylic acid hydroxyalkyl ester, ethylenically unsaturated carboxylic acid amide, ethylenically unsaturated sulfonic acid ester, ethylenically unsaturated alcohol, ethylenic Examples of the unsaturated alcohol ester, ethylenically unsaturated ether, ethylenically unsaturated amine, ethylenically unsaturated silane compound and aliphatic conjugated diene include the compounds exemplified as the other monomers in the acrylic resin.
Examples of the ethylenically unsaturated acid used in the methacrylic resin include the compounds exemplified as the ethylenically unsaturated acid in the acrylic resin, acrylic acid and methacrylic acid.

  The acrylic resin can be obtained by a method of polymerizing the above monomers. Examples of the polymerization method include an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, a liquid injection polymerization method (cast polymerization method), and the like. The polymerization is usually initiated by light irradiation or a polymerization initiator. Examples of the polymerization initiator include azo initiators such as 2,2′-azobisisobutyronitrile and 2,2′-azobis (2,4-dimethylvaleronitrile), lauroyl peroxide, benzoyl peroxide, and the like. It is preferable to use a polymerization initiator such as a peroxide-based initiator or a redox-based initiator in which an organic peroxide and an amine are combined. When using a polymerization initiator, it is used in the ratio of 0.01-1 mass part normally with respect to 100 mass parts of monomers, Preferably it is 0.01-0.5 mass part. Furthermore, a chain transfer agent for controlling the molecular weight (a linear or branched alkyl mercaptan compound such as methyl mercaptan, n-butyl mercaptan, t-butyl mercaptan, etc.), a crosslinking agent or the like may be added.

  The acrylic resin may have a ring structure in the molecular chain from the viewpoint of improving the heat resistance of the obtained optical material resin composition. Examples of the ring structure include a lactone ring structure, a glutaric anhydride structure, a glutaric imide structure, a maleic anhydride structure, and a maleimide structure.

An acrylic resin having a lactone ring structure in the molecular chain can be obtained, for example, by subjecting a methacrylic resin having a hydroxyl group and an ester group in the molecular chain to a cyclocondensation reaction in the molecule. As an acrylic resin having a hydroxyl group and an ester group in the molecular chain, for example, a monomer mixture containing monomers such as methacrylic acid ester, acrylic acid ester and 2- (hydroxyalkyl) alkyl acrylate is polymerized. What can be obtained can be mentioned. Examples of the methacrylic acid ester and acrylic acid ester include the above-mentioned methacrylic acid esters and acrylic acid esters.
Cyclocondensation is carried out, for example, by heating the acrylic resin, and the hydroxyl group and ester group present in the molecular chain of the acrylic resin are cyclized and condensed to produce a lactone ring structure. System resin can be obtained. In such a cyclocondensation reaction, an organic phosphorus compound is usually used as a catalyst.

  An acrylic resin having a glutaric anhydride structure in the molecular chain is, for example, a homopolymer of methyl methacrylate, a copolymer of methyl methacrylate and methacrylic acid, a copolymer of methyl methacrylate and acrylic acid, or The copolymer of methyl methacrylate, methacrylic acid and acrylic acid is usually 150 to 350 ° C., preferably 220 to 320 ° C. in the presence of a basic compound such as sodium hydroxide, potassium hydroxide or sodium methylate. It can be obtained by heat treatment for modification.

  An acrylic resin having a glutarimide structure in the molecular chain is, for example, a homopolymer of methyl methacrylate, a copolymer of methyl methacrylate and methacrylic acid, a copolymer of methyl methacrylate and acrylic acid, or It can be obtained by modifying a copolymer of methyl methacrylate, methacrylic acid and acrylic acid by heat treatment usually in the range of 150 to 350 ° C., preferably 220 to 320 ° C. in the presence of ammonia or a primary amine. it can.

  An acrylic resin having a maleic anhydride structure in the molecular chain can be obtained, for example, by copolymerizing methyl methacrylate and maleic anhydride. The acrylic resin having a maleimide structure in the molecular chain is obtained by copolymerizing, for example, methyl methacrylate and maleimide, N-substituted maleimide N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-benzylmaleimide, etc. Can be obtained at

  Among these methacrylic resins, polymethyl methacrylate, which is a homopolymer of methyl methacrylate, methyl methacrylate of 50% by mass or more and 99.9% by mass or less, and methyl methacrylate of 50% by mass or less and 0.1% by mass or more. Particularly preferred are copolymers with other (meth) acrylic acid esters. A copolymer of 50% by mass or more of methyl methacrylate and 50% by mass or less of (meth) acrylic acid ester other than methyl methacrylate is based on the total amount of methyl methacrylate and the (meth) acrylic acid ester. Copolymer obtained by polymerizing a monomer mixture containing methyl methacrylate in a proportion of 50% by mass or more and (meth) acrylic acid ester other than methyl methacrylate in a proportion of 50% by mass or less It is a coalescence. In this monomer mixture, methyl methacrylate is preferably contained in a proportion of 70 to 99.9% by mass, more preferably 90 to 99.9% by mass. In this mixture, (meth) acrylic acid esters other than methyl methacrylate are preferably contained in a proportion of 30 to 0.1% by mass, more preferably 10 to 0.1% by mass. The

  The viscosity average molecular weight (Mv) of the acrylic resin is preferably 50000 to 300000, more preferably 80000 to 200000, and still more preferably 100000 to 150,000.

Mv of the acrylic resin is obtained using the following formula (1).
lnMv = {ln [η] −ln (4.8 × 10 ⁻⁵ )} / 0.8 (1)
In the formula (1), [η] represents the intrinsic viscosity, and is obtained as a positive value satisfying the following formula (2) from the viscosity number VN measured according to ISO 1628-6.
VN = [η] + 0.4 × [η] ² (2)

<Polycarbonate resin>
Examples of the polycarbonate resin contained in the present resin composition include those obtained by reacting a dihydric phenol and a carbonylating agent by a method such as an interfacial polycondensation method or a melt transesterification method. Examples of the polycarbonate resin include those obtained by polymerizing a carbonate prepolymer by a solid phase transesterification method or the like. Examples of the polycarbonate resin include those obtained by polymerizing a cyclic carbonate compound by a ring-opening polymerization method.

  Examples of the dihydric phenol include hydroquinone, resorcinol, 4,4′-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, 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 called 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 Ci-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′-dihydroxydiphenylsulfone, 4,4′-dihydroxydiphenylsulfoxide, 4,4 ′ -Dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ester and the like. These may be used alone or in combination of two or more.

  Among these dihydric phenols, bisphenol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 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-hydroxyphenyl) -m-diisopropylbenzene are preferred. In particular, use of bisphenol A alone, bisphenol A, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 2,2-bis {(4-hydroxy-3-methyl) phenyl } Combination with at least one selected from the group consisting of propane and α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene is preferred.

  Examples of the carbonylating agent include carbonyl halides (such as phosgene), carbonate esters (such as diphenyl carbonate), and haloformates (such as dihaloformates of dihydric phenols). These may be used alone or in combination of two or more.

The viscosity average molecular weight (Mv) of the polycarbonate-based resin is preferably 5000 to 20000, more preferably 10,000 to 15000, and still more preferably 11,000 to 14,000. The Mv of the polycarbonate resin can be calculated from the intrinsic viscosity [η] of the 20 ° C. methylene chloride solution as a value satisfying the following Schnell equation.
[Η] = 1.23 × 10 ⁻⁴ Mv ^0.83

<Rubber elastic particles>
The rubber elastic particles are particles including a layer exhibiting rubber elasticity. The rubber elastic particles may be particles composed only of a layer exhibiting rubber elasticity, or particles having a multilayer structure having another layer together with a layer exhibiting rubber elasticity (hereinafter sometimes referred to as a rubber elastic layer). It may be. The layer exhibiting rubber elasticity includes a rubber elastic polymer. Examples of the rubber elastic polymer include olefin-based elastic polymers, diene-based elastic polymers, styrene-diene-based elastic copolymers, acrylic-based elastic polymers, and the like. Among these, an acrylic elastic polymer is preferable from the viewpoint of light resistance and transparency of the resin composition.

  The acrylic elastic polymer can be composed of a polymer mainly composed of alkyl acrylate. This may be a homopolymer of alkyl acrylate, or a copolymer of 50% by mass or more of alkyl acrylate and 50% by mass or less of other monomers. As the alkyl acrylate, those having 4 to 8 carbon atoms in the alkyl group are usually used. Examples of copolymerization of monomers other than alkyl acrylate include alkyl methacrylates such as methyl methacrylate and ethyl methacrylate, styrene monomers such as styrene and alkylstyrene, acrylonitrile and methacrylo Monofunctional monomers such as unsaturated nitriles such as nitriles, alkenyl esters of unsaturated carboxylic acids such as allyl (meth) acrylate and methallyl (meth) acrylate, and dibasic acids such as diallyl maleate And polyfunctional monomers such as unsaturated carboxylic acid diesters of glycols such as alkylene glycol di (meth) acrylate.

  The rubber elastic particles containing the acrylic elastic polymer are preferably multi-layered particles having an acrylic elastic polymer layer. Specifically, it has a two-layer structure having a hard polymer layer mainly composed of alkyl methacrylate on the outside of the acrylic elastic polymer, and further mainly comprises alkyl methacrylate on the inside of the acrylic elastic polymer. The thing of the 3 layer structure which has a hard polymer layer is mentioned. Examples of the monomer composition in the polymer mainly composed of alkyl methacrylate constituting the hard polymer layer formed on the outer side or the inner side of the acrylic elastic polymer are the methacrylic compounds mentioned above as examples of the acrylic resin. This is the same as the monomer composition example of a polymer mainly composed of an alkyl acid, and a monomer composition mainly composed of methyl methacrylate is preferably used. Such acrylic rubber elastic particles having a multilayer structure can be produced, for example, by the method described in Japanese Patent Publication No. 55-27576.

  The rubber elastic particles preferably have a number average particle diameter of the rubber elastic layer contained therein in the range of 10 to 350 nm. Thereby, since slight unevenness | corrugation is formed in the film surface, slipperiness can be improved. The average particle diameter of the rubber elastic particles is more preferably 30 nm or more, further 50 nm or more, and even more preferably 300 nm or less, further 280 nm or less.

  The number average particle diameter of the rubber elastic particles is measured as follows. That is, when such rubber elastic particles are mixed with an acrylic resin to form a film and the cross section thereof is dyed with an aqueous solution of ruthenium oxide, only the rubber elastic layer is colored and observed in a substantially circular shape. Acrylic resin is not dyed. Therefore, from the cross section of the film dyed in this way, a thin piece is prepared using a microtome or the like, and this is observed with an electron microscope. And after extracting 100 dye | stained rubber elastic body particles at random and calculating each diameter, let the number average value be a number average particle diameter.

  When the outermost layer is a hard polymer mainly composed of methyl methacrylate and the rubber elastic body particles in which the rubber elastic polymer is encapsulated are used, the rubber is mixed with the base acrylic resin. The outermost layer of the elastic particles is mixed with the base acrylic resin. Therefore, when the cross section is dyed with ruthenium oxide and observed with an electron microscope, the rubber elastic particles are observed as particles excluding the outermost layer. Specifically, when the rubber elastic particles having a two-layer structure in which the inner layer is a rubber elastic polymer and the outer layer is a hard polymer mainly composed of methyl methacrylate, the rubber elastic polymer of the inner layer is used. Part is dyed and observed as particles with a single layer structure, the innermost layer is a hard polymer mainly composed of methyl methacrylate, the intermediate layer is a rubber elastic polymer, and the outermost layer is made of methyl methacrylate. When rubber elastic particles having a three-layer structure, which is a main hard polymer, are used, a two-layer in which only the rubber elastic polymer portion of the intermediate layer is dyed without dyeing the central portion of the innermost particle. Observed as structured particles.

<Resin composition>
The present resin composition contains a polycarbonate-based resin and rubber elastic particles so that the product of the respective contents with respect to 100 parts by mass of the present resin composition is 1 or more and 120 or less. The product value is preferably 10 or more and 105 or less, and more preferably 30 or more and 55 or less.

  This resin composition contains a polycarbonate-type resin with respect to 100 mass parts of this resin composition, Preferably in the ratio of 0.1 to 10 mass parts. When the content of the polycarbonate resin is less than 0.1 parts by mass, the phase difference tends to increase. When the content of the polycarbonate-based resin exceeds 10 parts by mass, the transparency tends to decrease. The content of the polycarbonate-based resin with respect to 100 parts by mass of the present resin composition is more preferably 1 part by mass or more, further preferably 4 parts by mass or more, and more preferably 9 parts by mass or less, and still more preferably. Is 8 parts by mass or less, more preferably 6 parts by mass or less.

  The present resin composition contains rubber elastic body particles in a proportion of preferably 0.1 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the present resin composition. There exists a tendency for the elasticity modulus of this resin composition to become high enough that content of a rubber elastic body particle is 30 mass parts or less. Further, when the content of the rubber elastic body particles with respect to 100 parts by mass of the resin composition is 0.1 parts by mass or more, the film-forming property when molding a film from the resin composition, and the impact resistance of the obtained film In order to further improve the property, it is preferable, and by forming slight irregularities on the film surface, the slip property can be enhanced. The content of the rubber elastic particles with respect to 100 parts by mass of the acrylic resin is more preferably 25 parts by mass or less, still more preferably 20 parts by mass or less, still more preferably 15 parts by mass or less, and more Preferably it is 1 mass part or more, More preferably, it is 5 mass parts or more.

  The present resin composition may contain an additive. Additives include lubricants, stabilizers, antioxidants, UV absorbers, light stabilizers, colorants, foaming agents, lubricants, mold release agents, antistatic agents, flame retardants, polymerization inhibitors, flame retardant aids, reinforcement Agents and the like. These may be used alone or in combination of two or more. When the additive is added, the content thereof is preferably 0.005 to 30% by mass with respect to the present resin composition.

Examples of the lubricant include stearic acid compounds, acrylic compounds, and ester compounds, and stearic acid compounds are preferable.
By blending a lubricant into the resin composition, for example, it is possible to prevent tight tightening when a film made of the resin composition is wound into a roll, thereby improving the packing state in the wound state. The Any lubricant may be used as long as it has a function of improving the slipperiness of the film surface.

  The resin composition is transparent when visually observed. For example, the total light transmittance (Tt) of the optical film made of the resin composition obtained by molding the resin composition into a film is preferably more than 92.0. The total light transmittance (Tt) is measured according to JIS K7361-1.

  Another example of the transparency is haze measured according to JIS K7136. The internal haze of the optical film made of the present resin composition is preferably 0.4% or less. If the internal haze exceeds 0.4%, for example, when an optical film made of the present resin composition is incorporated in a display device, the white luminance is lowered and the screen becomes dark.

Examples of the phase difference index include a thickness direction phase difference (R _th ) measured with a light beam of 590 nm. _{R th} of the optical film made of the resin composition is preferably -7～7Nm.
_Further, the _{R th, ΔP = R th /} d calculated by dividing the optical film thickness was measured by a contact thickness meter is preferably ^{-75 × 10 -6 ~75 × 10 -6} , more preferably - a ^{50 × 10 -6 ~50 × 10 -6} , more preferably from ^{-30 × 10 -6 ~30 × 10 -6} .

<Method for producing the present resin composition>
As a manufacturing method of this resin composition, the method of melt-kneading acrylic resin, polycarbonate-type resin, and rubber elastic body particle | grains is mentioned. The melt-kneading is usually performed at a temperature of 180 to 300 ° C. and a shear rate of 10 to 1000 sec ⁻¹ .

When the temperature at the time of melt kneading is less than 180 ° C., the polycarbonate resin used may not be sufficiently melted. On the other hand, when the temperature at the time of melt kneading exceeds 300 ° C., the acrylic resin or polycarbonate resin to be used may be thermally decomposed. Furthermore, when the shear rate during melt kneading is less than 10 sec ⁻¹ , the acrylic resin and the polycarbonate resin may not be sufficiently kneaded. On the other hand, when the shear rate at the time of melt kneading exceeds 1000 sec ⁻¹ , the acrylic resin or the polycarbonate resin may be decomposed.
In order to obtain a resin composition in which each component is more uniformly mixed, the melt kneading is preferably performed at a temperature of 190 to 300 ° C., more preferably 200 to 300 ° C., preferably 20 to 700 sec ⁻¹ , and more. Preferably, it is carried out at a shear rate of 50 to 500 sec- ¹ .

  As an apparatus used for melt kneading, a normal mixer or kneader can be used. Specific examples include a single-screw kneader, a twin-screw kneader, a multi-screw extruder, a Henschel mixer, a Banbury mixer, a kneader, and a roll mill. Further, when the shear rate is increased within the above range, a high shear processing device or the like may be used. As a high shear processing apparatus, for example, “NHSS2-28” manufactured by Niigata Machine Techno Co., Ltd. is commercially available. Melt-kneading may be performed in an inert gas atmosphere such as nitrogen gas, argon gas, helium gas, if necessary.

  When the present resin composition contains the above-mentioned additive, the additive may be added in advance to at least one of the acrylic resin and the polycarbonate resin, or may be added at the time of melt kneading. It may be added before or after.

<Optical material>
The resin composition can be molded into a desired shape and used as an optical material that is excellent in retardation and impact resistance. Furthermore, the optical material comprising the resin composition tends to be excellent in transparency and weather resistance. Suitable optical materials for which the present resin composition is used include optical films, light guide plates, display front plates, signboards and the like.
In the molding process, the resin composition melt-kneaded by the above-described manufacturing method may be supplied to a molding machine while being heated and melted to be molded. Alternatively, the obtained resin composition may be formed into pellet-shaped resin pellets, which are heated and melted by a molding machine such as an injection molding machine, a hydraulic press, or an extrusion molding machine, and then molded. The molding temperature is usually about 150 to 350 ° C, preferably about 180 to 300 ° C, more preferably about 200 to 300 ° C.

  Since the present resin composition has a sufficiently small phase difference, the phase difference of the obtained optical material becomes small even if it is molded by extrusion molding in which the phase difference tends to increase.

<Optical film>
In the case of producing the optical film, for example, the resin composition can be produced by an extrusion molding method in which the resin composition is supplied to an extrusion molding machine to be heated and melted and then extruded from a die. As a method of extruding from the die, a normal method such as a feed block method or a multi-manifold method is employed.

  The heat-melted resin composition extruded from a die is usually formed into a film by being brought into close contact with a roll or a belt. The number, arrangement, and material of the rolls and belts at this time are not particularly limited. For example, the surface shape of a roll or belt can be obtained by passing a resin composition extruded from a die by heating and melting between two metal rolls, or by passing the resin composition in contact with a metal roll and a metal belt. Is preferable in terms of improving the surface accuracy of the film surface and improving the surface treatment. As two metal rolls, a metal roll having elasticity and a metal roll having no elasticity are used, and a resin composition in a heated and melted state immediately after being extruded from a die is sandwiched between these metal rolls, and resin The method of passing the composition while contacting the surfaces of both metal rolls is suitable for obtaining a film in which distortion during molding is reduced and strength and heat shrinkable anisotropy are reduced. The metal roll having elasticity includes, for example, a shaft roll and a cylindrical metal thin film that is arranged so as to cover the outer peripheral surface of the shaft roll and that contacts the molten resin. Among them, the one in which a fluid whose temperature is controlled, such as water or oil, is enclosed, and the one in which a metal belt is wound around the surface of a rubber roll.

  Thus, the thickness of the optical film obtained is 20-200 micrometers normally, Preferably it is 20-180 micrometers, More preferably, it is 20-170 micrometers.

<Polarizing plate>
Since an optical film made of the present resin composition has a low retardation and tends to be excellent in transparency, it is suitably used as a protective film laminated on at least one surface of a polarizing film in a polarizing plate. The protective film is bonded to the polarizing film using, for example, an adhesive.

(Polarizing film)
As the polarizing film, for example, a film obtained by adsorbing and orienting a dichroic dye on a polyvinyl alcohol-based resin film can be used. As the dichroic dye, iodine or a dichroic organic dye is used. Such a polarizing film has an absorption axis based on a dichroic dye that is adsorbed and oriented, and the dichroic dye absorbs a polarization component parallel to the absorption axis and transmits an orthogonal polarization component. Can do. A polarizing film having iodine adsorbed and oriented on a polyvinyl alcohol resin film is referred to as an iodine polarizing film, and a polarizing film having a dichroic organic dye adsorbed and oriented on a polyvinyl alcohol resin film is referred to as a dye polarizing film. Has been.

  The polyvinyl alcohol resin constituting the polarizing film can be obtained by saponifying the polyvinyl acetate resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and other monomers copolymerizable therewith is used. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, and unsaturated sulfonic acids. The polyvinyl alcohol resin may be modified, for example, polyvinyl formal, polyvinyl acetal, polyvinyl butyral and the like modified with aldehydes may be used.

  A polarizing film is usually a humidity adjusting step for adjusting the moisture of the polyvinyl alcohol-based resin film, a uniaxial stretching step for uniaxially stretching the polyvinyl alcohol-based resin film, and a dichroic dyeing of the polyvinyl alcohol-based resin film with a dichroic dye. It is manufactured through a dyeing process for adsorbing and orienting the dye, a boric acid treatment process for treating the polyvinyl alcohol resin film on which the dichroic dye is adsorbing and orienting with an aqueous boric acid solution, and a washing process for washing off the boric acid aqueous solution. The uniaxial stretching step can be performed before or after the dyeing step, or can be performed during the dyeing step. When performing a uniaxial stretching process after a dyeing process, it can also be performed during the boric acid treatment process after a dyeing process. The uniaxial stretching step may be performed in multiple steps. The method of uniaxial stretching may be a method of stretching uniaxially between rolls having different peripheral speeds, or a method of stretching uniaxially using a hot roll. Moreover, the dry-type extending | stretching which extends | stretches in air | atmosphere may be sufficient, and the wet extending | stretching which extends | stretches in the state swollen with the solvent may be sufficient. The draw ratio is usually about 4 to 8 times. The thickness of the finally obtained polarizing film is preferably about 1 to 50 μm, for example.

(Protective film)
When protective films are laminated on both sides of the polarizing film, the protective films laminated on both sides may be optical films made of the present resin composition, or the protective film laminated on one side may be the present resin composition. The protective film which consists of other transparent resin other than this resin composition may be sufficient as the protective film laminated | stacked on the other surface.
Examples of the film made of a resin other than the resin composition include acrylic resins (for example, methacrylic resins), chain polyolefin resins (for example, polypropylene resins), cyclic polyolefin resins, and polyvinyl chloride resins. , Cellulose resins such as cellulose acetate resins (for example, triacetyl cellulose, diacetyl cellulose, etc.), styrene resins, acrylonitrile / butadiene / styrene copolymer resins, acrylonitrile / styrene copolymer resins, polyvinyl acetate resins, Polyvinylidene chloride resin, polyamide resin, polyacetal resin, polycarbonate resin, modified polyphenylene ether resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polysulfone resin, polyester Terusuruhon resins, polyarylate resins, polyamide-imide resins, and the protective film made of polyimide resin.
The thickness of these protective films is usually 20 to 200 μm, preferably 20 to 170 μm.

  As a film made of a transparent resin other than the present resin composition, a retardation film such as a wave plate viewing angle compensation film such as a quarter wave plate or a half wave plate may be used. By laminating such a retardation film, the number of films used can be reduced as compared with the case where a retardation film is used independently of a polarizing plate. Therefore, it is possible to reduce the weight and thickness of a liquid crystal display device using a polarizing plate. As a retardation film such as a wave plate or a viewing angle compensation film, a conventionally known film can be used. The retardation film is, for example, a polycarbonate resin, a polyvinyl alcohol resin, a polystyrene resin, an acrylic resin, a polyolefin resin (eg, polypropylene), a cyclic polyolefin resin, a polyarylate resin, a polyimide resin, or a polyamide resin. It can be obtained by stretching a film made of a resin or the like by an appropriate method such as uniaxial or biaxial. The retardation film may be a birefringent film in which the refractive index in the thickness direction of the film is controlled by applying a shrinkage force and / or stretching force under adhesion with the heat-shrinkable film.

(Lamination of polarizing film, optical film and protective film)
In order to laminate an optical film made of the present resin composition, another protective film, or the like on a polarizing film, it is usually sufficient to bond using an adhesive. Prior to bonding, at least one of the bonding surfaces of each film is preferably subjected to corona discharge treatment, plasma irradiation treatment, electron beam irradiation treatment, and other surface activation treatment.

  The adhesive can be arbitrarily selected and used from those that exhibit adhesive strength to each member. A typical example is an active energy ray-curable adhesive containing a component that is cured by irradiation with an active energy ray.

  When an active energy ray-curable adhesive is used, components that cure by irradiation of active energy rays constituting the active energy ray (hereinafter sometimes simply referred to as “curable components”) include epoxy compounds, oxetane compounds, acrylics. System compounds and the like. When a cationically polymerizable compound such as an epoxy compound or an oxetane compound is used, a cationic polymerization initiator is blended. When a radical polymerizable compound such as an acrylic compound is used, a radical polymerization initiator is blended. Among them, an adhesive having an epoxy compound as one of the curable components is preferable, and an adhesive having an alicyclic epoxy compound in which an epoxy group is directly bonded to a saturated hydrocarbon ring as one of the curable components is particularly preferable. . It is also effective to use an oxetane compound in combination.

  Epoxy compounds can be easily obtained from commercial products. For example, “Epicoat (registered trademark)” series sold by Japan Epoxy Resin Co., Ltd. and DIC Corporation, respectively, under the trade name. "Epicron (registered trademark)" series, "Epototo (registered trademark)" series sold by Toto Kasei Co., Ltd., "Adeka Resin" series sold by ADEKA Corporation, from Nagase ChemteX Corporation Examples include the “Denacol (registered trademark)” series sold, the “Dow Epoxy” series sold by Dow Chemical Company, and “Tepic (registered trademark)” sold by Nissan Chemical Industries, Ltd.

  An alicyclic epoxy compound in which an epoxy group is directly bonded to a saturated hydrocarbon ring can also be easily obtained as a commercial product, for example, sold under the trade name by Daicel Chemical Industries, Ltd. Examples include the “Celoxide (registered trademark)” series and the “Cyclomer (registered trademark)” series, and the “Cyracure” series sold by Dow Chemical.

  Oxetane compounds can also be easily obtained as commercial products. For example, “Aron Oxetane (registered trademark)” series sold by Toagosei Co., Ltd. and Ube Industries, Ltd. "ETERNACOLL (registered trademark)" series and the like.

  Cationic polymerization initiators can also be easily obtained as commercial products. For example, the “Kayarad (registered trademark)” series sold by Nippon Kayaku Co., Ltd., and Union Carbide, Inc. "Syracure" series, photo acid generators "CPI (registered trademark)" series sold by San Apro Co., Ltd., photo acid generators "TAZ", "BBI" sold by Midori Chemical Co., Ltd. and “DTS”, “Adekaoptomer” series sold by ADEKA Corporation, “RHODORSIL (registered trademark)” series sold by Rhodia, and the like.

  The active energy ray-curable adhesive can contain a photosensitizer as necessary. By using a photosensitizer, the reactivity is improved, and the mechanical strength and adhesive strength of the cured product layer can be further improved. Examples of the photosensitizer include carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, anthracene compounds, halogen compounds, and photoreducible dyes.

  Moreover, various additives can be mix | blended with an active energy ray hardening adhesive in the range which does not impair the adhesiveness. Examples of the additive include an ion trap agent, an antioxidant, a chain transfer agent, a tackifier, a thermoplastic resin, a filler, a flow regulator, a plasticizer, and an antifoaming agent. Furthermore, a curable component that cures by a reaction mechanism different from cationic polymerization can be blended within a range that does not impair the adhesion.

  As described above, the active energy ray-curable adhesive described above is applied to the bonding surface of the optical film or the bonding surface of the polarizing film, and after bonding both films through the coating layer, the active energy ray is applied thereto. It is cured by irradiation and becomes an adhesive layer that joins the polarizing film and the optical film. Moreover, it is apply | coated to the bonding surface of a polarizing film, or the bonding surface of a protective film, and after bonding both films through the coating layer, it is hardened by irradiating an active energy ray there, and a polarizing film and a protective film It becomes the adhesive bond layer which joins. The adhesive for forming the adhesive layer and the adhesive for forming the adhesive layer may be the same composition or different compositions, but irradiation with active energy rays for curing both Are preferably performed simultaneously.

  The active energy ray used for curing the active energy ray-curable adhesive may be, for example, X-ray having a wavelength of 1 to 10 nm, ultraviolet light having a wavelength of 10 to 400 nm, visible light having a wavelength of 400 to 800 nm, and the like. Among these, ultraviolet rays are preferably used in view of ease of use and ease of preparation of active energy ray-curable adhesive, stability and curing performance. As the ultraviolet light source, for example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a chemical lamp, a black light lamp, a microwave excitation mercury lamp, a metal halide lamp or the like having a light emission distribution at a wavelength of 400 nm or less may be used. it can.

  The thickness of the adhesive layer obtained using the active energy ray-curable adhesive is usually about 1 to 50 μm, and particularly preferably in the range of 1 to 10 μm.

  The polarizing plate thus obtained is obtained by laminating an optical film made of the present resin composition on at least one side of a polarizing film made of a polyvinyl alcohol-based resin, and the present resin composition on one side of the polarizing film. The optical film which consists of is laminated | stacked, and the protective film which consists of another transparent resin is laminated | stacked on the other surface.

<Acrylic resin>
A methacrylic resin composed of a methyl methacrylate monomer unit and a methyl acrylate monomer unit and containing 97% by mass of the methyl methacrylate monomer unit and 3% by mass of the methyl acrylate monomer unit was used. The viscosity average molecular weight was 124,000.
<Polycarbonate resin>
TR2201 manufactured by Sumika Stylon Polycarbonate Co., Ltd. was used. The viscosity average molecular weight was 11,900.
<Rubber elastic particles>
As rubber elastic particles, the innermost layer is a hard polymer obtained by polymerization of a monomer composition consisting of 93.8% methyl methacrylate, 6.0% methyl acrylate, and 0.2% allyl methacrylate. The intermediate layer is an elastic polymer obtained by polymerization of a monomer composition consisting of 81% butyl acrylate, 17% styrene and 2% allyl methacrylate, and the outermost layer is 94% methyl methacrylate. Is a hard polymer obtained by polymerization of a monomer composition comprising 6% of methyl acrylate, and the mass ratio of the innermost layer / the intermediate layer / the outermost layer is 35/45/20, Elastic rubber particles having a spherical three-layer structure obtained by an emulsion polymerization method in which the average particle size of the elastic polymer layer is 0.22 μm were used.
The average particle diameter of the rubber elastic particles is obtained by mixing the rubber elastic particles with the methacrylic resin to form a film, dyeing the elastic polymer (intermediate layer) with ruthenium oxide in the cross section, and observing with an electron microscope. It was determined from the diameter of the stained part.
<Refractive index>
The refractive index was measured at 25 ° C. using an Abbe refractometer manufactured by Atago Co., Ltd.
<Total light transmittance>
Using a transmittance meter (HR-100, manufactured by Murakami Color Research Laboratory Co., Ltd.), it was measured according to JIS K7361-1.
<Internal haze>
Dimethyl phthalate was placed in a liquid cell, the film was immersed therein, and measurement was performed using a transmittance meter (HR-100, manufactured by Murakami Color Research Laboratory Co., Ltd.) according to JIS K7136.
<Phase difference>
An in-plane retardation value (R ₀ ) and a thickness direction retardation (R _th ) of the optical film were measured at a wavelength of 590 nm using a retardation measuring device KOBRA-WR manufactured by Oji Scientific Instruments.
<Birefringence>
R ₀ and R _th measured using a phase difference measuring device KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. are divided by the optical film thickness measured with a contact thickness meter, and ΔN _xy = R ₀ / d and ΔP = R _th / d was calculated.
<Bendability>
The case where the optical film was bent with a finger and was broken was rated as x, and the case where it was not broken was marked as o.

<Adjustment of resin composition>
The acrylic resin, the polycarbonate resin, and the rubber elastic particles are mixed with a super mixer at a ratio shown in Table 1, and melt-kneaded with a twin-screw extruder. The pellet of the resin composition which consists of a polycarbonate-type resin and rubber elastic-body particle | grains was obtained.

<Manufacture of optical film made of the present resin composition>
Each obtained resin composition was melt-kneaded with a single screw extruder with a vent having a screw diameter of 65 mm, and the molten resin was supplied to a T-die. Next, the supplied molten resin is continuously extruded from the T die into a film shape, and the film-shaped molten resin continuously extruded from the T die is placed between a pair of metal rolls having smooth surfaces. The optical film was obtained by sandwiching, forming and cooling. Table 2 shows the physical property values of the obtained optical film.

  The resin composition of the present invention is useful for obtaining an optical material having a sufficiently low retardation and excellent impact resistance.

Claims (13)

A resin composition comprising an acrylic resin, a polycarbonate resin, and rubber elastic particles,
And pair the resin composition 100 parts by weight,
The content of the polycarbonate resin is 7.0 parts by mass or less,
The content of rubber elastic particles is 10.4 to 15.0 parts by mass,
And the content of the polycarbonate resin, the content of the resin composition product is more than 62 105 following the rubber elastic particles. The resin composition according to claim 1, wherein the content of the polycarbonate-based resin is 0.1 parts by mass or more with respect to 100 parts by mass of the resin composition. The resin composition according to claim 1 or 2 , wherein the polycarbonate-based resin has a viscosity average molecular weight of 5,000 to 20,000. The resin composition according to any one of claims 1 to 3 , wherein the rubber elastic particles include an acrylic elastic polymer. The resin composition according to any one of claims 1 to 4 , wherein the acrylic resin is a homopolymer of methacrylic acid ester or a copolymer of methacrylic acid ester and a monomer other than methacrylic acid ester. . The resin composition according to claim 5 , wherein the monomer other than the methacrylic acid ester is an acrylic acid ester. A method for producing the resin composition according to any one of claims 1 to 6 ,
The method for producing a resin composition according to any one of claims 1 to 6 , wherein the acrylic resin, the polycarbonate resin, and the rubber elastic particles are melt-kneaded. Optical material comprising the resin composition according to any one of claims 1-6. The optical film which consists of a resin composition in any one of Claims 1-6 . The optical film obtained by extrusion-molding the resin composition in any one of Claims 1-6 . The optical film according to claim 9 or 10 , which has a thickness of 20 µm to 200 µm. On at least one surface of the polarizing film, a polarizing plate having an optical film according to any one of claims 9-11. On one surface of the polarizing film has an optical film according to any one of claims 9-11, a polarizing plate having a different protective film and the optical film to the other surface.