JP5463848B2 - Optical compensation film and manufacturing method thereof - Google Patents

Description

  The present invention relates to an optical compensation film having an optical compensation function for a liquid crystal display element and excellent in optical characteristics such as wavelength dependency, and a method for producing the same. Specifically, it is an optical compensation film with an increased Rth (out-of-plane retardation), and a thinner optical compensation film is expected.

  Liquid crystal displays are widely used as the most important display devices in the multimedia society, from mobile phones to computer monitors, notebook computers, and televisions. Many optical films are used in liquid crystal displays to improve display characteristics.

  In particular, the optical compensation film plays a major role in improving the contrast when viewed from the front or obliquely, compensating for the color tone, and the like. As conventional optical compensation films, polycarbonate, cyclic polyolefin, cellulose resin biaxially stretched film, etc. are used, but with the thinning of displays, the development of materials with higher optical compensation functions with thinner films Is required.

  Harris and Chen of Akron University have proposed an optical compensation film made of rigid rod-shaped polyimide, polyester, polyamide, poly (amide-imide), and poly (ester-imide) (see, for example, Patent Documents 1 and 2). ), These materials have a characteristic of expressing a phase difference without undergoing a biaxial stretching process by coating because of their spontaneous molecular orientation.

  Furthermore, an optical compensation film made of polyimide with improved polyimide coating properties (solubility in a solvent) (see, for example, Patent Document 3), and a polarizing plate obtained by applying a discotic liquid crystal compound to a protective film of a polarizing plate (See, for example, Patent Document 4).

  Moreover, the stretched film (for example, refer patent document 5) which consists of a phenylmaleimide-isobutene copolymer, and the optical compensation film | membrane which consists of maleimide resin are disclosed (for example, refer patent document 6).

US Pat. No. 5,344,916 Japanese National Patent Publication No. 10-508048 Japanese Patent Laid-Open No. 2005-070745 Japanese Patent No. 2565644 JP 2008-287226 A

  However, since the polymer used in the methods proposed in Patent Documents 1 to 3 is an aromatic polymer, the wavelength dependency of the phase difference amount is large, and when used as an optical compensation film of a liquid crystal display element, color misregistration, etc. It has a problem of image quality degradation.

  In addition, the method using the discotic liquid crystal compound proposed in Patent Document 4 not only has problems such as requiring uniform alignment of the liquid crystal compound, complicating the coating process, and large alignment unevenness. Since the liquid crystal compound is mainly composed of an aromatic compound, it also has a quality problem that the wavelength dependency of the retardation amount is large.

  Patent Document 5 describes that, for example, an ultraviolet absorber such as benzotriazole, benzophenone, triazine, benzoate, or the like may be blended as necessary, but Rth (surface) is added. The effect of increasing the external phase difference amount) is not described.

  Therefore, the present invention aims to provide an optical compensation film having excellent optical properties, and more specifically, a biaxial stretching comprising a specific resin having excellent transparency and a cyclic hydrocarbon compound. An object of the present invention is to provide an optical compensation film that is expected to be thinned by biaxial stretching to increase Rth.

  As a result of intensive studies in view of the above problems, the inventors of the present invention are biaxially stretched optical compensation films comprising a specific resin and a cyclic hydrocarbon compound, and an optical compensation film having a specific relationship in three-dimensional refractive index. The present inventors have found that an optical compensation film having an optical compensation function, particularly an optical compensation film suitable for optical compensation for a liquid crystal display element, has been completed.

  That is, the present invention is a biaxially stretched optical compensation film made of a maleimide resin and a cyclic hydrocarbon compound, and the stretch axis directions of the optical compensation film are the x axis and the y axis in the film plane, and are orthogonal to this. The three-dimensional refractive index relationship when the out-of-plane direction is the z-axis, the refractive index in the x-axis direction is nx, the refractive index in the y-axis direction is ny, and the refractive index in the z-axis direction is nz is nx≈ny> nz It is related with the optical compensation film | membrane characterized by these.

  Hereinafter, the optical compensation film of the present invention will be described in detail.

  The optical compensation film of the present invention is a biaxially stretched optical compensation film comprising a maleimide resin and a cyclic hydrocarbon compound, and the stretching axis directions of the optical compensation film are the x-axis and y-axis in the film plane. The three-dimensional refractive index relationship is nx≈ when the out-of-plane direction perpendicular to the z axis is the z axis, the refractive index in the x axis direction is nx, the refractive index in the y axis direction is ny, and the refractive index in the z axis direction is nz. An optical compensation film characterized in that ny> nz.

By adding the above cyclic hydrocarbon compound, nx and ny increase and nz decreases. Therefore, by changing the addition amount of the cyclic hydrocarbon compound, Rth represented by the general formula (5) is increased. be able to.
Rth = ((nx + ny) / 2−nz) × d (5)
(Here, d represents the film thickness (nm) of the optical compensation film.)
Further, by performing biaxial stretching here, nx and ny are further increased, and therefore it is possible to express high Rth with a thinner film thickness.

  Examples of the maleimide resin used in the optical compensation film of the present invention include N-substituted maleimide polymer resin, N-substituted maleimide-maleic anhydride copolymer resin, and the like, and N-substituted resin constituting the maleimide resin. Examples of maleimide residue units include N-substituted maleimide residue units represented by the following general formula (1).

（ここで、Ｒ_１は、炭素数１〜１８の直鎖状アルキル基，炭素数１〜１８の分岐状アルキル基，炭素数１〜１８の環状アルキル基、ハロゲン基、エーテル基、エステル基、アミド基を示す。）
一般式（１）で示されるＮ−置換マレイミド残基単位におけるＲ_１は、炭素数１〜１８の直鎖状アルキル基，炭素数１〜１８の分岐状アルキル基，炭素数１〜１８の環状アルキル基、ハロゲン基、エーテル基、エステル基、アミド基であり、炭素数１〜１８の直鎖状アルキル基としては、例えばメチル基、エチル基、クロロエチル基、メトキシエチル基、ｎ−プロピル基、ｎ−ブチル基、ｎ−ヘキシル基、ｎ−オクチル基、ｎ−ラウリル基等が挙げられ、炭素数１〜１８の分岐状アルキル基としては、例えばイソプロピル基、イソブチル基、ｓ−ブチル基、ｔ−ブチル基等が挙げられ、炭素数１〜１８の環状アルキル基としては、例えばシクロヘキシル基等が挙げられ、ハロゲン基としては、例えば塩素、臭素、フッ素、ヨウ素等の１種又は２種以上が挙げられ、特にＲｔｈが大きく、溶剤への溶解性、機械的強度に優れる光学補償膜となることから、ｎ−ブチル基、イソブチル基、ｓ−ブチル基、ｔ−ブチル基、ｎ−ヘキシル基、ｎ−オクチル基等が好ましい。

(Here, R ₁ is a linear alkyl group having 1 to 18 carbon atoms, a branched alkyl group having 1 to 18 carbon atoms, a cyclic alkyl group having 1 to 18 carbon atoms, a halogen group, an ether group, an ester group, Indicates an amide group.)
R ₁ in the N-substituted maleimide residue unit represented by the general formula (1) is a linear alkyl group having 1 to 18 carbon atoms, a branched alkyl group having 1 to 18 carbon atoms, or cyclic having 1 to 18 carbon atoms. An alkyl group, a halogen group, an ether group, an ester group, an amide group, and examples of the linear alkyl group having 1 to 18 carbon atoms include a methyl group, an ethyl group, a chloroethyl group, a methoxyethyl group, an n-propyl group, An n-butyl group, an n-hexyl group, an n-octyl group, an n-lauryl group, and the like can be mentioned. Examples of the branched alkyl group having 1 to 18 carbon atoms include isopropyl group, isobutyl group, s-butyl group, t -Butyl group etc. are mentioned, As a C1-C18 cyclic alkyl group, a cyclohexyl group etc. are mentioned, for example, As a halogen group, one sort of chlorine, bromine, fluorine, iodine, etc., or Two or more types can be mentioned, and since it becomes an optical compensation film having particularly large Rth and excellent solubility in a solvent and mechanical strength, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n -A hexyl group, n-octyl group, etc. are preferable.

  Specific examples of the N-substituted maleimide residue unit include, for example, an N-methylmaleimide residue unit, an N-ethylmaleimide residue unit, an N-chloroethylmaleimide residue unit, an N-methoxyethylmaleimide residue unit, Nn-propylmaleimide residue unit, N-isopropylmaleimide residue unit, Nn-butylmaleimide residue unit, N-isobutylmaleimide residue unit, Ns-butylmaleimide residue unit, Nt- 1 type or 2 types, such as a butyl maleimide residue unit, a Nn-hexyl maleimide residue unit, a N-cyclohexyl maleimide residue unit, a Nn-octyl maleimide residue unit, a Nn-lauryl maleimide residue unit In particular, since the Rth is large, it becomes an optical compensation film excellent in solubility in a solvent and mechanical strength. Maleimide residue unit, N-isobutylmaleimide residue unit, Ns-butylmaleimide residue unit, Nt-butylmaleimide residue unit, Nn-hexylmaleimide residue unit, Nn-octylmaleimide residue Base units and the like are preferred.

  Examples of the N-substituted maleimide polymer resin include N-methylmaleimide polymer resin, N-ethylmaleimide polymer resin, N-chloroethylmaleimide polymer resin, N-methoxyethylmaleimide polymer resin, Nn- Propylmaleimide polymer resin, N-isopropylmaleimide polymer resin, Nn-butylmaleimide polymer resin, N-isobutylmaleimide polymer resin, Ns-butylmaleimide polymer resin, Nt-butylmaleimide polymer Examples thereof include resin, Nn-hexylmaleimide polymer resin, N-cyclohexylmaleimide polymer resin, Nn-octylmaleimide polymer resin, and Nn-laurylmaleimide polymer resin.

  Examples of the N-substituted maleimide polymer resin include N-methylmaleimide polymer resin, N-ethylmaleimide polymer resin, N-chloroethylmaleimide polymer resin, N-methoxyethylmaleimide polymer resin, Nn- Propylmaleimide polymer resin, N-isopropylmaleimide polymer resin, Nn-butylmaleimide polymer resin, N-isobutylmaleimide polymer resin, Ns-butylmaleimide polymer resin, Nt-butylmaleimide polymer Examples thereof include resin, Nn-hexylmaleimide polymer resin, N-cyclohexylmaleimide polymer resin, Nn-octylmaleimide polymer resin, and Nn-laurylmaleimide polymer resin.

  Examples of the N-substituted maleimide-maleic anhydride copolymer resin include N-methylmaleimide-maleic anhydride copolymer resin, N-ethylmaleimide-maleic anhydride copolymer resin, and N-chloroethylmaleimide-anhydride. Maleic acid copolymer resin, N-methoxyethylmaleimide-maleic anhydride copolymer resin, Nn-propylmaleimide-maleic anhydride copolymer resin, N-isopropylmaleimide-maleic anhydride copolymer resin, N -N-butylmaleimide-maleic anhydride copolymer resin, N-isobutylmaleimide-maleic anhydride copolymer resin, Ns-butylmaleimide-maleic anhydride copolymer resin, Nt-butylmaleimide-anhydrous Maleic acid copolymer resin, Nn-hexylmaleimide-maleic anhydride copolymer resin, N- Black hexyl maleimide - maleic anhydride copolymer resin, N-n-octyl maleimide - maleic anhydride copolymer resin, N-n-lauryl maleimide - can be mentioned maleic anhydride copolymer resin.

  Among them, the Nn-butylmaleimide polymer resin, the Nn-butylmaleimide polymer resin, and the Nn-butylmaleimide polymer resin, which are particularly excellent in film forming properties during film formation and become an optical compensation film excellent in optical compensation function and heat resistance, Nn-octylmaleimide polymer resin, Nn-octylmaleimide-maleic anhydride copolymer resin and the like are preferable, and Nn-butylmaleimide polymer resin and Nn-hexylmaleimide polymer are particularly preferable. Resins are preferred.

  Further, the maleimide resin constituting the optical compensation film of the present invention contains a residue unit other than the N-substituted maleimide residue unit and the maleic anhydride residue unit without departing from the object of the present invention. The residue unit may be, for example, a styrene residue unit such as a styrene residue unit or an α-methylstyrene residue unit; an acrylic acid residue unit; a methyl acrylate residue unit, or an ethyl acrylate residue. Units, acrylate residue units such as butyl acrylate residue units; methacrylic acid residue units; methacrylic acid ester residues such as methyl methacrylate residue units, ethyl methacrylate residue units, butyl methacrylate residue units Unit: Vinyl acetate residue unit such as vinyl acetate residue unit and vinyl propionate residue unit; acrylonitrile residue unit; methacrylonitrile residue It can be exemplified one or two or more units, and the like.

Moreover, as this maleimide-type resin, the number average molecular weight (Mn) of standard polystyrene conversion obtained from the elution curve measured by gel permeation chromatography (henceforth GPC) is 1 * 10 < ³ > or more. In particular, it is preferably 2 × 10 ⁴ or more and 2 × 10 ⁵ or less because it becomes an optical compensation film having excellent mechanical properties and excellent moldability during film formation.

  The maleimide resin constituting the optical compensation film of the present invention may be produced by any method as long as the maleimide resin is obtained. For example, N-substituted maleimides, maleic anhydride, and in some cases It can be produced by performing radical polymerization or radical copolymerization using a monomer copolymerizable with N-substituted maleimides. Examples of N-substituted maleimides include N-methylmaleimide, N-ethylmaleimide, N-chloroethylmaleimide, N-methoxyethylmaleimide, Nn-propylmaleimide, N-isopropylmaleimide, Nn- 1 such as butylmaleimide, N-isobutylmaleimide, Ns-butylmaleimide, Nt-butylmaleimide, Nn-hexylmaleimide, N-cyclohexylmaleimide, Nn-octylmaleimide, Nn-laurylmaleimide Examples of the copolymerizable monomer include styrenes such as styrene and α-methylstyrene; acrylic acid; acrylic esters such as methyl acrylate, ethyl acrylate, and butyl acrylate. Methacrylic acid; methyl methacrylate, methacrylate Methacrylic acid esters such as butyl methacrylate, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl laurate, vinyl stearate, etc .; acrylonitrile; one or more of methacrylonitrile, etc. Can be mentioned.

  Further, as the radical polymerization method, it can be carried out by a known polymerization method, and for example, any of a bulk polymerization method, a solution polymerization method, a suspension polymerization method, a precipitation polymerization method, an emulsion polymerization method and the like can be adopted. .

  Examples of the polymerization initiator used in the radical polymerization method include benzoyl peroxide, lauryl peroxide, octanoyl peroxide, acetyl peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, and dicumyl peroxide. , Organic peroxides such as t-butylperoxyacetate and t-butylperoxybenzoate; 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-butyronitrile), 2 , 2′-azobisisobutyronitrile, dimethyl-2,2′-azobisisobutyrate, 1,1′-azobis (cyclohexane-1-carbonitrile) and the like.

  And there is no restriction | limiting in particular as a solvent which can be used in a solution polymerization method, a suspension polymerization method, a precipitation polymerization method, and an emulsion polymerization method, For example, aromatic solvents, such as benzene, toluene, xylene; Methanol, ethanol, propyl alcohol, butyl alcohol Alcohol solvents such as cyclohexane, dioxane, tetrahydrofuran (THF), acetone, methyl ethyl ketone, dimethylformamide, isopropyl acetate, water, N-methylpyrrolidone, and the like, and mixed solvents thereof.

  Moreover, the polymerization temperature at the time of performing radical polymerization can be suitably set according to the decomposition temperature of a polymerization initiator, and generally it is preferable to carry out in the range of 40-150 degreeC.

  The present invention is a biaxially stretched optical compensation film in which a cyclic hydrocarbon compound is added to a maleimide resin, and it has been found that Rth increases by adding the cyclic hydrocarbon compound. As the cyclic hydrocarbon compound, a compound satisfying any one of the following general formulas (2), (3), and (4) is preferable, and compounds of the general formulas (2) and (3) are particularly preferable, and one type or two types are preferable. A combination of the above can be used.

（式中、Ｘ_１、Ｘ_２、Ｘ_３はそれぞれ水素原子、ハロゲン原子、置換もしくは無置換のアミノ基、メルカプト基、スルホン酸基、アルコキシ基、アルデヒド基、カルボキシル基、アルキル基、アルケニル基、アルキニル基、芳香族環を表し、それぞれが同一のものであっても、異なるものであってもよい。）
一般式（２）のＸ_１、Ｘ_２、Ｘ_３におけるハロゲン原子としては、例えばＦ、Ｃｌ、Ｂｒ、Ｉ等が挙げられ、置換もしくは無置換のアミノ基としては、例えば−ＮＨ_２、−ＮＨＣＨ_３、−Ｎ（ＣＨ_３）_２、−ＮＨＣ_２Ｈ_５、−Ｎ（Ｃ_２Ｈ_５）_２、−ＮＨＣ_３Ｈ_７、−Ｎ（Ｃ_３Ｈ_７）_２、−ＮＨ（Ｃ_４Ｈ_９）、−Ｎ（Ｃ_４Ｈ_９）_２、−ＮＨＰｈ、等が挙げられ、アルコキシ基としては、例えばメトキシ基、エトキシ基、ｎ−プロポキシ基、ｉ−プロポキシ基、ｎ−ブトキシ基、ｉ−ブトキシ基、ｔ−ブトキシ基、ｓ−ブトキシ基等が挙げられ、アルキル基としては炭素原子数１〜８であることが好ましく、例えばメチル、エチル、ｎ−ブチル、ｎ−ヘキシル等が挙げられ、アルケニル基としては炭素原子数２〜８であることが好ましく、例えばビニル、アリル、１−ヘキセニル等が挙げられ、アルキニル基としては炭素原子数２〜８であることが好ましく、例えばエチニル、１−ブチニル、１−ヘキシニル等が挙げられる。

(Wherein X ₁ , X ₂ and X ₃ are each a hydrogen atom, a halogen atom, a substituted or unsubstituted amino group, a mercapto group, a sulfonic acid group, an alkoxy group, an aldehyde group, a carboxyl group, an alkyl group, an alkenyl group, An alkynyl group and an aromatic ring, each of which may be the same or different.
Examples of the halogen atom in X ₁ , X ₂ , and X ₃ in the general formula (2) include F, Cl, Br, and I. Examples of the substituted or unsubstituted amino group include —NH ₂ and —NHCH. _{3, -N (CH 3) 2} , -NHC 2 H 5, -N (C 2 H 5) 2, -NHC 3 H 7, -N (C 3 H 7) 2, -NH (C 4 H 9) , —N (C ₄ H ₉ ) ₂ , —NHPh, and the like. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, and an i-butoxy group. , T-butoxy group, s-butoxy group and the like, and the alkyl group preferably has 1 to 8 carbon atoms, such as methyl, ethyl, n-butyl, n-hexyl and the like, and an alkenyl group As having 2 to 8 carbon atoms Preferably, for example, vinyl, allyl, 1-hexenyl and the like are exemplified. The alkynyl group preferably has 2 to 8 carbon atoms, and examples thereof include ethynyl, 1-butynyl, 1-hexynyl and the like.

  In addition to the aromatic hydrocarbon ring, the aromatic ring includes an aromatic heterocyclic ring and an aromatic condensed ring. Examples of the aromatic hydrocarbon ring include a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, Examples include a thiazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyrimidine ring, a pyrazine ring, and a 1,3,5-triazine ring. The number of aromatic rings is preferably 1-20, more preferably 1-12, and even more preferably 1-8.

  The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. As the hetero atom, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable. Examples of the aromatic heterocycle include, for example, furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring. , Pyridazine ring, pyrimidine ring, pyrazine ring, 1,3,5-triazine ring and the like.

  Examples of the aromatic condensed ring include, for example, indene ring, naphthalene ring, azulene ring, fluorene ring, phenanthrene ring, anthracene ring, acenaphthylene ring, biphenylene ring, naphthacene ring, pyrene ring, indole ring, isoindole ring, benzofuran ring, Benzothiophene ring, indolizine ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring, purine ring, indazole ring, chromene ring, quinoline ring, isoquinoline ring, quinolidine ring, quinazoline ring, cinnoline ring, quinoxaline ring , Phthalazine ring, pteridine ring, carbazole ring, acridine ring, phenanthridine ring, xanthene ring, phenazine ring, phenothiazine ring, phenoxathiin ring, phenoxazine ring, thianthrene ring, naphthalene ring, azulene , Indole ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring, quinoline ring and the like.

  The aromatic ring may have a substituent. However, the substituent is required not to sterically hinder the conformation of the two aromatic rings. In steric hindrance, the type and position of substituents are problematic. As the type of the substituent, a sterically bulky substituent (for example, a tertiary alkyl group) tends to cause steric hindrance. As the position of the substituent, steric hindrance is likely to occur when a position adjacent to the bond of the aromatic ring (ortho position in the case of a benzene ring) is substituted.

  Examples of the substituent include, for example, a halogen atom (F, Cl, Br, I), hydroxyl, carboxyl, cyano, amino, nitro, sulfo, carbamoyl, sulfamoyl, ureido, alkyl group, alkenyl group, alkynyl group, aliphatic acyl Group, aliphatic acyloxy group, alkoxy group, alkoxycarbonyl group, alkoxycarbonylamino group, alkylthio group, alkylsulfonyl group, aliphatic amide group, aliphatic sulfonamido group, aliphatic substituted amino group, aliphatic substituted carbamoyl group, fatty acid Group-substituted sulfamoyl group, aliphatic substituted ureido group, non-aromatic heterocyclic group and the like.

  It is preferable that the alkyl group has 1 to 8 carbon atoms. A chain alkyl group is preferable to a cyclic alkyl group, and a linear alkyl group is particularly preferable. The alkyl group may further have a substituent (eg, hydroxy, carboxy, alkoxy group, alkyl-substituted amino group). Examples of alkyl groups (including substituted alkyl groups) include methyl, ethyl, n-butyl, n-hexyl, 2-hydroxyethyl, 4-carboxybutyl, 2-methoxyethyl, 2-diethylaminoethyl and the like. .

  The alkenyl group preferably has 2 to 8 carbon atoms. A chain alkenyl group is preferable to a cyclic alkenyl group, and a linear alkenyl group is particularly preferable. The alkenyl group may further have a substituent. Examples of alkenyl groups include vinyl, allyl, 1-hexenyl and the like.

  The alkynyl group preferably has 2 to 8 carbon atoms. A chain alkynyl group is preferable to a cyclic alkynyl group, and a linear alkynyl group is particularly preferable. The alkynyl group may further have a substituent. Examples of alkynyl groups include ethynyl, 1-butynyl, 1-hexynyl and the like.

  The number of carbon atoms in the aliphatic acyl group is preferably 1-10. Examples of the aliphatic acyl group include acetyl, propanoyl, butanoyl and the like.

  The number of carbon atoms in the aliphatic acyloxy group is preferably 1-10. Examples of aliphatic acyloxy groups include acetoxy, for example.

  The number of carbon atoms of the alkoxy group is preferably 1-8. The alkoxy group may further have a substituent (eg, a substituted alkoxy group). Examples of alkoxy groups (including substituted alkoxy groups) include methoxy, ethoxy, butoxy, methoxyethoxy and the like.

  The number of carbon atoms of the alkoxycarbonyl group is preferably 2-10. Examples of the alkoxycarbonyl group include methoxycarbonyl, ethoxycarbonyl and the like.

  The number of carbon atoms of the alkoxycarbonylamino group is preferably 2-10. Examples of the alkoxycarbonylamino group include methoxycarbonylamino, ethoxycarbonylamino and the like.

  The alkylthio group preferably has 1 to 12 carbon atoms. Examples of the alkylthio group include, for example, methylthio, ethylthio, octylthio and the like.

  The alkylsulfonyl group preferably has 1 to 8 carbon atoms. Examples of the alkylsulfonyl group include methanesulfonyl, ethanesulfonyl and the like.

  The number of carbon atoms in the aliphatic amide group is preferably 1-10. Examples of aliphatic amide groups include, for example, acetamide.

  The number of carbon atoms of the aliphatic sulfonamide group is preferably 1-8. Examples of the aliphatic sulfonamide group include methanesulfonamide, butanesulfonamide, n-octanesulfonamide and the like.

  The number of carbon atoms of the aliphatic substituted amino group is preferably 1-10. Examples of the aliphatic substituted amino group include dimethylamino, diethylamino, 2-carboxyethylamino and the like.

  The number of carbon atoms in the aliphatic substituted carbamoyl group is preferably 2-10. Examples of the aliphatic substituted carbamoyl group include, for example, methylcarbamoyl, diethylcarbamoyl and the like.

  The number of carbon atoms in the aliphatic substituted sulfamoyl group is preferably 1-8. Examples of the aliphatic substituted sulfamoyl group include, for example, methylsulfamoyl, diethylsulfamoyl and the like.

  The number of carbon atoms in the aliphatic substituted ureido group is preferably 2-10. Examples of aliphatic substituted ureido groups include, for example, methylureido.

  Examples of non-aromatic heterocyclic groups include piperidino and morpholino.

Among these, as X ₁ , X ₂ and X ₃ in the general formula (2), a mercapto group and an aromatic ring are preferable.

  Specific examples of the compound represented by the general formula (2) include 2,4-diamino-6-butylamino-1,3,5-triazine, 2,4,6-trimercapto-1,3,5- Triazine, 2,4,6-triphenyl-1,3,5-triazine, 2-methoxy-4-methyl-6- (methylamino) -1,3,5-triazine, 2-amino-4-methoxy- 6-methyl-1,3,5-triazine and the like, particularly 2,4,6-trimercapto-1,3,5-triazine, 2,4,6-triphenyl-1,3,5-triazine Is preferred.

（式中Ｘ_４、Ｘ_５、Ｘ_６はそれぞれ、単結合またはアルキレン基、アルケニレン基、アルキニレン基、芳香族環、−ＮＨ−、−ＮＲ−、−Ｓ−、−ＣＯ−、−Ｏ−、を表し、Ｒ_２、Ｒ_３、Ｒ_４は水素原子、置換もしくは無置換のアルキル基、アルケニル基、芳香族環を表す。）
一般式（３）のＸ_４、Ｘ_５、Ｘ_６におけるアルキレン基としては炭素原子数１〜８であることが好ましく、例えばメチレン、エチレン、ｎ−ブチレン、ｎ−ヘキシレン等が挙げられ、アルケニレン基としては炭素原子数２〜８であることが好ましく、例えばビニレン、アリレン、１−ヘキセニレン等が挙げられ、アルキニレン基としては炭素原子数２〜８であることが好ましく、例えばエチニレン、１−ブチニレン、１−ヘキシニレン等が挙げられる。

(Wherein X ₄ , X ₅ and X ₆ are each a single bond or an alkylene group, an alkenylene group, an alkynylene group, an aromatic ring, —NH—, —NR—, —S—, —CO—, —O—, R ₂ , R ₃ and R ₄ represent a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group and an aromatic ring.
The alkylene group in X ₄ , X ₅ and X ₆ in the general formula (3) preferably has 1 to 8 carbon atoms, and examples thereof include methylene, ethylene, n-butylene, n-hexylene, and the like, alkenylene group Is preferably 2 to 8 carbon atoms, for example, vinylene, arylene, 1-hexenylene, etc., and the alkynylene group preferably has 2 to 8 carbon atoms, such as ethynylene, 1-butynylene, Examples include 1-hexynylene.

The aromatic ring includes an aromatic heterocyclic ring and an aromatic condensed ring in addition to the aromatic hydrocarbon ring, and examples thereof include an aromatic ring of X ₁ , X ₂ , and X _{3 in} the general formula (2).

The substituted or unsubstituted alkyl group in R ₂ , R ₃ and R ₄ in the general formula (3) preferably has 1 to 8 carbon atoms, such as methyl, ethyl, n-butyl, n-hexyl and the like. The alkenyl group preferably has 2 to 8 carbon atoms, such as vinyl, allyl, 1-hexenyl and the like, and the alkynyl group preferably has 2 to 8 carbon atoms, such as ethynyl. , 1-butynyl, 1-hexynyl and the like.

The aromatic ring includes an aromatic heterocyclic ring and an aromatic condensed ring in addition to the aromatic hydrocarbon ring, and examples thereof include an aromatic ring of X ₁ , X ₂ , and X _{3 in} the general formula (2).

  Specific examples of the compound represented by the general formula (3) include 2,4-diamino-6- [2- (2-methyl-1-imidazolyl) ethyl] -1,3,5-triazine, 6- ( Dibutylamino) -2,4-dimercapto-1,3,5-triazine, 2- (3,4-dimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- ( 3-carboxyanilino) -4,6-dichloro-1,3,5-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2, 4,6-trianilinyl-1,3,5-triazine, 2,4-diamino-6-diallylamino-1,3,5-triazine, 2- [2- (5-methylfuran-2-yl) vinyl] -4,6-bis (trichloromethyl -1,3,5-triazine and the like, in particular 2,4,6-trianilinyl-1,3,5-triazine, 6- (dibutylamino) -2,4-dimercapto-1,3,5-triazine 2,4-diamino-6-diallylamino-1,3,5-triazine is preferred.

（式中Ｘ_７、Ｘ_８、Ｘ_９はそれぞれ、単結合またはアルキレン基、アルケニレン基、アルキニレン基、芳香族環、−ＮＨ−、−ＮＲ−、−Ｓ−、−ＣＯ−、−Ｏ−を表し、Ｒ_５、Ｒ_６、Ｒ_７は水素原子、置換もしくは無置換のアルキル基、アルケニル基、芳香族環を表す。）
一般式（４）のＸ_７、Ｘ_８、Ｘ_９におけるアルキレン基としては炭素原子数１〜８であることが好ましく、例えばメチレン、エチレン、ｎ−ブチレン、ｎ−ヘキシレン等が挙げられ、アルケニレン基としては炭素原子数２〜８であることが好ましく、例えばビニレン、アリレン、１−ヘキセニレン等が挙げられ、アルキニレン基としては炭素原子数２〜８であることが好ましく、例えばエチニレン、１−ブチニレン、１−ヘキシニレン等が挙げられる。

(Wherein X ₇ , X ₈ and X ₉ are each a single bond or an alkylene group, an alkenylene group, an alkynylene group, an aromatic ring, —NH—, —NR—, —S—, —CO—, —O—). R ₅ , R ₆ and R ₇ represent a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group and an aromatic ring.
The alkylene group in X ₇ , X ₈ and X ₉ in the general formula (4) preferably has 1 to 8 carbon atoms, and examples thereof include methylene, ethylene, n-butylene, n-hexylene, and the like, alkenylene group Is preferably 2 to 8 carbon atoms, for example, vinylene, arylene, 1-hexenylene, etc., and the alkynylene group preferably has 2 to 8 carbon atoms, such as ethynylene, 1-butynylene, Examples include 1-hexynylene.

The aromatic ring includes an aromatic heterocyclic ring and an aromatic condensed ring in addition to the aromatic hydrocarbon ring, and examples thereof include an aromatic ring of X ₁ , X ₂ , and X _{3 in} the general formula (2).

The substituted or unsubstituted alkyl group in R ₅ , R ₆ and R ₇ in the general formula (4) preferably has 1 to 8 carbon atoms, such as methyl, ethyl, n-butyl, n-hexyl, etc. The alkenyl group preferably has 2 to 8 carbon atoms, such as vinyl, allyl, 1-hexenyl, etc., and the alkynyl group preferably has 2 to 8 carbon atoms. For example, ethynyl, 1-butynyl, 1-hexynyl and the like.

The aromatic ring includes an aromatic heterocyclic ring and an aromatic condensed ring in addition to the aromatic hydrocarbon ring, and examples thereof include an aromatic ring of X ₁ , X ₂ , and X _{3 in} the general formula (2).

  Specific examples of the compound represented by the general formula (4) include 1,3,5-benzenetrithiol, 1,3,5-benzenetricarbonyltrichloride, 1,3,5-triphenylbenzene, N, N ″, N ″ ″-triphenyl-1,3,5-benzenetriamine, 1,3,5-tri (9H-carbazol-9-yl) benzene, 1,3,5-tri-t-butyl Examples include benzene, 1,3,5-triacetylbenzene, 1,3,5-trimethoxybenzene, 1,3,5-tris (4-bromophenyl) benzene, and more particularly 1,3,5-triphenyl. Benzene, N, N ″, N ″ ″-triphenyl-1,3,5-benzenetriamine are preferred.

  The molecular weight of these cyclic hydrocarbon compounds is preferably 100 to 800.

  The blending ratio of the maleimide resin and the cyclic hydrocarbon compound in the optical compensation film of the present invention is such that an optical compensation film having excellent adhesion to the substrate can be obtained, so that the cyclic carbonization is performed with respect to 100 parts by weight of the maleimide resin. The hydrogen compound is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, and particularly preferably 0.5 to 5 parts by weight.

  Moreover, there is no restriction | limiting in particular as a compounding method of a maleimide-type resin and a cyclic hydrocarbon type compound, For example, it can carry out by adding a cyclic hydrocarbon type compound to the solution which melt | dissolved the maleimide-type resin in the solvent. .

  The solvent used in that case is not particularly limited as long as the maleimide resin can be dissolved, for example, aromatic solvents such as toluene, xylene, chlorobenzene, nitrobenzene; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. Ketone solvents; ether solvents such as dimethyl ether, diethyl ether, methyl-t-butyl ether, tetrahydrofuran and dioxane; acetate solvents such as methyl acetate, ethyl acetate, acetic acid-n-propyl, isopropyl acetate and butyl acetate; hexane, Hydrocarbon solvents such as cyclohexane, octane, decane; alcohol solvents such as methanol, ethanol, propanol, butanol; salts such as carbon tetrachloride, chloroform, methylene chloride, dichloroethane, trichloroethane System solvent; dimethylformamide, amide solvents such as dimethylacetamide; N- methylpyrrolidone and the like, which may be used in combination of two or more.

  The optical compensation film of the present invention is a biaxially stretched optical compensation film comprising a maleimide resin and a cyclic hydrocarbon compound, and a preferable production method includes a glass substrate, a cellulose resin such as triacetyl cellulose, and the like. Coating film obtained by coating a solution made of a maleimide resin and a cyclic hydrocarbon compound on a substrate such as a film made, a polyacrylic film, a polyethylene terephthalate (PET) film, or a cyclic polyolefin film, and drying Is produced by biaxial stretching, and the maleimide resin is preferably a maleimide resin comprising a maleimide residue unit represented by the general formula (1).

  The coating method is a solution obtained by dissolving a maleimide resin and a cyclic hydrocarbon compound in a solvent, a glass substrate, a film made of a cellulose resin such as triacetyl cellulose, a polyacrylic film, a polyethylene terephthalate (PET) film, a cyclic polyolefin. In this method, after coating on a substrate such as a film, the solvent is removed by heating or the like. As a coating method at that time, for example, a doctor blade method, a bar coater method, a gravure coater method, a slot die coater method, a lip coater method, a comma coater method or the like is used. In industry, the gravure coater method is generally used for thin film coating, and the comma coater method is generally used for thick film coating.

  In solution coating, since an optical compensation film having higher transparency and excellent thickness accuracy and surface smoothness can be obtained, the solution viscosity is preferably 10 to 10000 cps, particularly 10 to 5000 cps. It is preferable to

  In this case, the coating thickness of the film composed of the maleimide resin and the cyclic hydrocarbon compound is determined by the Rth (out-of-plane retardation) of the coating film, and among them, excellent surface smoothness and improved viewing angle. Is preferably 0.1 to 200 μm after drying, more preferably 0.5 to 100 μm, and particularly preferably 1 to 50 μm.

  The biaxial stretching of the optical compensation film of the present invention is not particularly limited. Generally, the stretching ratio is 1. in the stretching temperature range of −50 to + 50 ° C. of the glass transition temperature of the maleimide resin measured using a differential scanning calorimeter. The film can be stretched in the range of 1 to 5 times. In particular, since the optical characteristics such as phase difference, light transmittance, and haze are greatly affected by the thickness, it is preferable to reduce the thickness unevenness as much as possible. In the biaxial stretching of the optical compensation film of the present invention, the stretching temperature can be lowered by controlling the drying conditions during production and leaving the solvent. Moreover, it is also possible to exfoliate and extend | stretch from a base material, and it is also possible to extend | stretch together a laminated body with a base material.

  Specific examples of the biaxial stretching method include a method in which a solution composed of a maleimide resin and a cyclic hydrocarbon compound is applied on a substrate, and is dried and then biaxially stretched. Examples of the biaxial stretching method that can be adopted include a method of stretching by a tenter, a method of rolling by a calendar and stretching, and a method of stretching between rolls.

  The optical compensation film of the present invention is a biaxially stretched optical compensation film made of a maleimide resin and a cyclic hydrocarbon compound. The biaxially stretched film increases Rth and imparts a high optical compensation function. .

  The optical compensation film of the present invention is a biaxially stretched optical compensation film comprising a maleimide resin and a cyclic hydrocarbon compound, and the stretching axis directions of the optical compensation film are the x-axis and y-axis in the film plane, and The three-dimensional refractive index relationship is nx≈ny> where the orthogonal direction is the z-axis, the refractive index in the x-axis direction is nx, the refractive index in the y-axis direction is ny, and the refractive index in the z-axis direction is nz. It is an optical compensation film characterized by being nz.

  The optical compensation film of the present invention preferably has an Rth (out-of-plane retardation amount) represented by the following general formula (5) by adding a cyclic hydrocarbon compound as compared with the case where no addition is performed. It can be increased to 2 times or more, more preferably 1.5 times or more.

Rth = ((nx + ny) / 2−nz) × d (5)
(Here, d represents the film thickness (nm) of the optical compensation film.)
As described above, these cyclic hydrocarbon compounds can increase the Rth of the optical compensation film with a relatively small amount of use, and can adjust the increase amount of Rth according to the addition amount. Moreover, since it is relatively compatible with the maleimide resin, it is difficult to precipitate (bleed out) on the surface of the film. Therefore, by using such a cyclic hydrocarbon compound, it is possible to easily obtain a film in which the Rth of the optical compensation film is adjusted to an arbitrary value.

  The Rth of the optical compensation film of the present invention changes the thickness of the coating film composed of the maleimide resin and the cyclic hydrocarbon compound, the blending ratio of the maleimide resin and the cyclic hydrocarbon compound, and the biaxial stretching conditions. Therefore, Rth is preferably in the range of 50 to 2000 nm, and the viewing angle of the liquid crystal display element is further improved because the optical compensation film can be easily controlled and can be adapted as a retardation film. Since it is excellent in effect, it is preferably in the range of 70 to 1000 nm, particularly 120 to 500 nm.

  The optical compensation film of the present invention is preferably a liquid crystal display element having a small color shift when used in a liquid crystal display element, so that the wavelength dependency of the phase difference amount is preferably small, and it is tilted by 40 degrees and has a measurement wavelength of 450 nm. The wavelength dependence (R450 / R589) of the phase difference indicated by the ratio of the phase difference (R450) measured with the light of R and the phase difference (R589) measured with the light having the measurement wavelength of 589 nm is 1.1 or less. In particular, it is preferably 1.08 or less.

  Further, the optical compensation film of the present invention may contain an antioxidant in order to improve the thermal stability. Examples of the antioxidant include hindered phenol antioxidants, phosphorus antioxidants, and other antioxidants. These antioxidants may be used alone or in combination. And since an antioxidant effect | action improves synergistically, it is preferable to use together and use a hindered phenolic antioxidant and phosphorus antioxidant, for example, 100 weight part of hindered phenolic antioxidants in that case It is particularly preferable to use a phosphorous antioxidant mixed in an amount of 100 to 500 parts by weight. Further, the addition amount of the antioxidant is preferably 0.01 to 10 parts by weight, particularly in the range of 0.5 to 1 part by weight with respect to 100 parts by weight of the maleimide resin constituting the optical compensation film of the present invention. Preferably there is.

  The optical compensation film of the present invention is blended with other polymers, polymer electrolytes, conductive complexes, inorganic fillers, pigments, dyes, antistatic agents, antiblocking agents, lubricants and the like within the scope of the invention. It may be.

  The optical compensation film of the present invention can be used after being peeled off from the substrate, and can also be used as a laminate (an optical compensation film) with the substrate or another optical film. In particular, as another optical film when used as a laminate with another optical film, a cellulose-based film and a cyclic polyolefin film are preferable in terms of transparency and strength.

  When the optical compensation film of the present invention and an optical compensation film of a substrate are used, the coating film made of the maleimide resin and the cyclic hydrocarbon compound is laminated on the substrate, and a biaxially stretched laminate. It is preferable to do.

  Examples of the substrate include films made of cellulose resin such as triacetyl cellulose, polyacrylic film, and cyclic polyolefin film.

  As a method for producing an optical compensation film, for example, a solution comprising a maleimide resin and a cyclic hydrocarbon compound is applied to a substrate, and the laminate of the substrate and the coating film obtained by drying is biaxially stretched. The method of doing is mentioned.

  Examples of the biaxial stretching method include a method of stretching with a tenter, a method of rolling and stretching with a calendar, and a method of stretching between rolls.

  The optical compensation film has a stretching axis direction as x1 axis and y1 axis, an out-of-plane direction perpendicular thereto as z1 axis, a refractive index in x1 axis direction as nx1, a refractive index in y1 axis direction as ny1, and a z1 axis direction. The three-dimensional refractive index relationship when the refractive index is nz1 is preferably nx1≈ny1> nz1.

  The optical compensation film preferably has an Rth (out-of-plane retardation value) represented by the general formula (5) in the range of 50 to 2000 nm, and is excellent in the effect of improving the viewing angle of the liquid crystal display element. Is preferably in the range of 70 to 1000 nm, particularly 120 to 500 nm.

  Since the optical compensation film becomes a liquid crystal display element with small color shift when used in a liquid crystal display element, it is preferable that the wavelength dependency of the retardation amount is small, and it is tilted by 40 degrees with light having a measurement wavelength of 450 nm. It is preferable that the wavelength dependency (R450 / R589) of the phase difference amount indicated by the ratio of the measured phase difference amount (R450) and the phase difference amount (R589) measured with light having a measurement wavelength of 589 nm is 1.1 or less. In particular, it is preferably 1.08 or less.

  Since the optical compensation film has good image quality characteristics when used in a liquid crystal display device, the light transmittance measured in accordance with JIS K 7361-1 (1997 edition) may be 85% or more. It is preferably 90% or more. Further, the haze (cloudiness) measured in accordance with JIS K 7136 (2000 version) is preferably 2% or less, and particularly preferably 1% or less.

  The optical compensation film is preferably one having high heat resistance from the stability of quality when used for a liquid crystal display element, and preferably has a glass transition temperature of 100 ° C. or more of the maleimide resin used, and further 120 ° C. Those above are preferable, and those having a temperature of 135 ° C. or more are particularly preferable.

  The optical compensation film of the present invention can be used by being laminated with a polarizing plate.

  The optical compensation film of the present invention can be used as an optical compensation film for liquid crystal display elements such as a viewing angle improving film and a color compensation film for liquid crystal display elements.

  The optical compensation film of the present invention is a biaxially stretched optical compensation film comprising a maleimide-based resin and a cyclic hydrocarbon-based compound, and a thinner optical compensation film by increasing Rth (out-of-plane retardation). Therefore, it is useful as an optical compensation film effective for improving the contrast and viewing angle characteristics of a liquid crystal display element, particularly a VA-mode liquid crystal television.

  EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

~ Measurement of number average molecular weight (Mn) ~
Using gel permeation chromatography (GPC) (manufactured by Tosoh Corporation, trade name HLC-802A), dimethylformamide was used as a solvent to obtain a standard polystyrene equivalent value.

~ Measurement of glass transition temperature ~
A differential scanning calorimeter (manufactured by Seiko Denshi Kogyo Co., Ltd., trade name DSC2000) was used and the temperature was 10 ° C / min. It measured at the temperature increase rate of.

~ Measurement of light transmittance ~
As an evaluation of transparency, light transmittance was measured in accordance with JIS K 7361-1 (1997 edition).

~ Measurement of haze ~
As an evaluation of transparency, haze was measured according to JIS K 7136 (2000 version).

~ Measurement of refractive index ~
It measured using the Abbe refractometer (product made from Atago) based on JISK7142 (1981 edition).

~ Calculation of 3D refractive index ~
Using a sample tilt type automatic birefringence meter (trade name KOBRA-WR, manufactured by Oji Scientific Instruments Co., Ltd.), the elevation angle was changed and the three-dimensional refractive index was measured with light having a measurement wavelength of 589 nm. Further, Re (in-plane retardation) and Rth (out-of-plane retardation) were calculated from the three-dimensional refractive index.

~ Measurement of wavelength dependence of phase difference ~
The wavelength dependence (R450 / R589) of the phase difference amount is the ratio of the phase difference amount (R450) measured with light having a measurement wavelength of 450 nm tilted by 40 degrees and the phase difference amount (R589) measured with light having a measurement wavelength of 589 nm. Indicated.

Synthesis Example 1 (Example of production of Nn-butylmaleimide polymer resin)
A glass sealed tube was charged with 32.4 g of Nn-butylmaleimide and 0.054 g of dimethyl-2,2′-azobisisobutyrate as a polymerization initiator, and after substitution with nitrogen, a polymerization temperature of 60 ° C. and a polymerization time of 5 The radical polymerization reaction was performed under time conditions. After the reaction, chloroform was added to form a polymer solution, and the polymer was precipitated by mixing with excess methanol. The obtained polymer was filtered, washed sufficiently with methanol and dried at 80 ° C. to obtain 20 g of Nn-butylmaleimide polymer resin. The number average molecular weight of the obtained Nn-butylmaleimide polymer resin was 120,000. The glass transition temperature (hereinafter referred to as Tg) was 185 ° C.

Synthesis Example 2 (Production Example of Nn-Hexylmaleimide Polymer Resin)
In a glass sealed tube, 40 g of Nn-hexylmaleimide and 0.05 g of dimethyl-2,2′-azobisisobutyrate as a polymerization initiator are charged, and after nitrogen substitution, a polymerization temperature of 60 ° C. and a polymerization time of 5 hours. The radical polymerization reaction was performed under the following conditions. After the reaction, chloroform was added to form a polymer solution, and the polymer was precipitated by mixing with excess methanol. The obtained polymer was filtered, sufficiently washed with methanol, and dried at 80 ° C. to obtain 32 g of Nn-hexylmaleimide polymer resin. The number average molecular weight of the obtained Nn-hexylmaleimide polymer resin was 160000. Moreover, Tg was 148 degreeC.

Comparative Example 1
The Nn-butylmaleimide polymer resin obtained in Synthesis Example 1 is dissolved in a mixed solvent composed of 50 parts by weight of toluene and 50 parts by weight of methyl ethyl ketone to form a 13% solution, and the surface is coated with silicon by a coater. The resulting film was cast on the PET film substrate and dried at room temperature for 48 hours to obtain a laminate (coating film + substrate) having a width of 50 mm and a thickness of 61 μm (thickness only of the coating film).

  The obtained coating film was biaxially stretched 1.5 times at 150 ° C., and the optical properties after stretching were evaluated. The physical properties of the obtained coating film are shown below.

  The obtained coating film had a thickness of 50 μm, a light transmittance of 91.0%, a haze of 0.6%, and a three-dimensional refractive index of nx = 1.53014, ny = 1.53010, and nz = 1.52855. Yes, Rth = 78.5 m, Re = 2.0 nm. Furthermore, R450 / R589 which shows the wavelength dependence of phase difference amount was 1.05.

Comparative Example 2
The solution prepared in the same manner as in Comparative Example 1 was further added with 2,4,6-trimercapto-1,3,5-cyclic hydrocarbon compound to 100 parts by weight of Nn-butylmaleimide polymer resin. After adding 3 parts by weight of triazine (compound of general formula (2)), it was cast on a PET film substrate whose surface was coated with silicon by a coater, dried at room temperature for 48 hours, and 50 mm wide and 50 μm thick. A laminate (coating film + base material) having a thickness of only the coating film was obtained. The physical properties of the obtained coating film are shown below.

  The obtained coating film had a thickness of 50 μm, a light transmittance of 91.1%, a haze of 0.6%, and a three-dimensional refractive index of nx = 1.51843, ny = 1.1.5842, and nz = 1.51626. Yes, Rth = 108.3 m, Re = 0.5 nm. Furthermore, R450 / R589 which shows the wavelength dependence of phase difference amount was 1.05.

  As a result, although the obtained coating film has a relationship of nx≈ny> nz, the value of Rth is not sufficient because it is unstretched.

Example 1
Except for changing the amount of 2,4,6-trimercapto-1,3,5-triazine added to 1 part by weight, the width was 50 mm and the thickness was 60 μm (thickness of the coating film only) in the same manner as in Comparative Example 2. A laminate (coating film + base material) was obtained.

  The obtained coating film was biaxially stretched 1.5 times at 150 ° C., and the optical properties after stretching were evaluated. The physical properties of the obtained coating film are shown below.

  The obtained coating film has a thickness of 50 μm, a light transmittance of 90.9%, a haze of 0.7%, and a three-dimensional refractive index of nx = 1.53022, ny = 1.53020, and nz = 1.52734. Yes, Rth = 143.5 m, Re = 1.0 nm. Furthermore, R450 / R589 which shows the wavelength dependence of phase difference amount was 1.05.

  As a result, the obtained coated film had a tendency of nx≈ny> nz more than the coated film of only the Nn-butylmaleimide polymer resin shown in Comparative Example 1, and the cyclic hydrocarbon It is a film in which Rth is increased by the compound. In addition, since the wavelength dependence is small, it can be said that a thin film is expected and it is more excellent as an optical compensation film.

Example 2
Except for changing the amount of 2,4,6-trimercapto-1,3,5-triazine added to 3 parts by weight, the width was 50 mm (thickness of the coated film only) and the thickness was 58 μm in the same manner as in Example 1. A laminate (coating film + base material) was obtained.

  The obtained coating film was biaxially stretched 1.5 times at 150 ° C., and the optical properties after stretching were evaluated. The physical properties of the obtained coating film are shown below.

  The obtained coating film had a thickness of 50 μm, a light transmittance of 91.0%, a haze of 0.6%, and a three-dimensional refractive index of nx = 1.53031, ny = 1.530311, and nz = 1.52686. Yes, Rth = 172.5 m, Re 0.0 nm. Furthermore, R450 / R589 which shows the wavelength dependence of phase difference amount was 1.06.

  As a result, the obtained coated film had a tendency of nx≈ny> nz more than the coated film of only the Nn-butylmaleimide polymer resin shown in Comparative Example 1, and the cyclic hydrocarbon It is a film in which Rth is increased by the compound. In addition, since the wavelength dependence is small, it can be said that a thin film is expected and it is more excellent as an optical compensation film.

Example 3
A width of 50 mm was obtained in the same manner as in Example 1, except that the cyclic hydrocarbon compound was changed to 2,4-dimercapto-6-dibutylamino-1,3,5-triazine (compound of general formula (3)). A laminate (coating film + base material) having a thickness of 59 μm (thickness only of the coating film) was obtained.

  The obtained coating film was biaxially stretched 1.5 times at 150 ° C., and the optical properties after stretching were evaluated. The physical properties of the obtained coating film are shown below.

  The obtained coating film has a thickness of 50 μm, a light transmittance of 91.2%, a haze of 0.6%, and a three-dimensional refractive index of nx = 1.53021, ny = 1.53019, and nz = 1.57441. Yes, Rth = 139.5 m, Re = 1.0 nm. Furthermore, R450 / R589 which shows the wavelength dependence of phase difference amount was 1.05.

  As a result, the obtained coated film had a tendency of nx≈ny> nz more than the coated film of only the Nn-butylmaleimide polymer resin shown in Comparative Example 1, and the cyclic hydrocarbon It is a film in which Rth is increased by the compound. In addition, since the wavelength dependence is small, it can be said that a thin film is expected and it is more excellent as an optical compensation film.

Example 4
Except for changing the amount of 2,4-dimercapto-6-dibutylamino-1,3,5-triazine to 3 parts by weight, the width was 50 mm and the thickness was 60 μm (only the coating film only) in the same manner as in Example 3. (Thickness) laminate (coating film + substrate) was obtained.

  The obtained coating film was biaxially stretched 1.5 times at 150 ° C., and the optical properties after stretching were evaluated. The physical properties of the obtained coating film are shown below.

  The obtained coating film had a thickness of 50 μm, a light transmittance of 91.1%, a haze of 0.7%, and a three-dimensional refractive index of nx = 1.53029, ny = 1.53025, and nz = 1.52720. Yes, Rth = 153.5 m, Re = 2.0 nm. Furthermore, R450 / R589 which shows the wavelength dependence of phase difference amount was 1.05.

  As a result, the obtained coated film had a tendency of nx≈ny> nz more than the coated film of only the Nn-butylmaleimide polymer resin shown in Comparative Example 1, and the cyclic hydrocarbon It is a film in which Rth is increased by the compound. In addition, since the wavelength dependence is small, it can be said that a thin film is expected and it is more excellent as an optical compensation film.

Comparative Example 3
The Nn-hexylmaleimide polymer resin obtained in Synthesis Example 2 was dissolved in a mixed solvent composed of 50 parts by weight of toluene and 50 parts by weight of methyl ethyl ketone to form a 12% solution, and a 185 μm cyclic polyolefin film group was formed by a coater. It was cast on a material and dried at room temperature for 48 hours to obtain a laminate (coating film + base material) having a width of 50 mm and a total thickness of 195 μm.

  The obtained laminate was biaxially stretched 1.25 times at 140 ° C., and the optical properties after stretching were evaluated. The physical properties of the obtained laminate are shown below.

  The obtained laminate has a thickness of 180 μm, a light transmittance of 91.8%, a haze of 0.6%, and a three-dimensional refractive index of nx1 = 1.53018, ny1 = 1.53016, and nz1 = 1.52983. Rth = 61.2 m and Re = 3.6 nm. Furthermore, R450 / R589 which shows the wavelength dependence of phase difference amount was 1.06.

Comparative Example 4
2,4-Diamino-6-diallylamino-1,3, as a cyclic hydrocarbon compound, with respect to 100 parts by weight of Nn-hexylmaleimide polymer resin in a solution prepared in the same manner as in Comparative Example 3. After adding 3 parts by weight of 5-triazine (compound of general formula (3)), it was cast on a 185 μm cyclic polyolefin film substrate by a coater, dried at room temperature for 48 hours, 50 mm wide and 195 μm total thickness. A laminate (coating film + base material) was obtained. The physical properties of the obtained laminate are shown below.

  The obtained laminate has a thickness of 180 μm, a light transmittance of 91.8%, a haze of 0.6%, and a three-dimensional refractive index of nx1 = 1.53009, ny1 = 1.53009, and nz1 = 1.52988. Rth = 37.8 m and Re = 0.0 nm. Furthermore, R450 / R589 which shows the wavelength dependence of phase difference amount was 1.06.

  As a result, although the obtained laminate has a relationship of nx1≈ny1> nz1, the value of Rth is not sufficient because it is unstretched.

Example 5
A laminate (coating with a width of 50 mm and a total thickness of 195 μm was produced in the same manner as in Comparative Example 3 except that the amount of 2,4-diamino-6-diallylamino-1,3,5-triazine was changed to 1 part by weight. (Film + substrate) was obtained.

  The obtained laminate was biaxially stretched 1.25 times at 140 ° C., and the optical properties after stretching were evaluated. The physical properties of the obtained laminate are shown below.

  The obtained laminate has a thickness of 180 μm, a light transmittance of 91.7%, a haze of 0.6%, and a three-dimensional refractive index of nx1 = 1.53089, ny1 = 1.53089, and nz1 = 1.53013. Rth = 136.8 m, Re = 0.0 nm. Furthermore, R450 / R589 which shows the wavelength dependence of phase difference amount was 1.06.

  As a result, the obtained laminate had a tendency of nx1≈ny1> nz1 more strongly than the laminate of only the Nn-hexylmaleimide polymer resin shown in Comparative Example 3, and the cyclic hydrocarbon compound Rth is rising. In addition, since the wavelength dependence is small, it can be said that a thin film is expected and it is more excellent as an optical compensation film.

Example 6
A laminate (coating having a width of 50 mm and a total thickness of 193 μm was produced in the same manner as in Example 5 except that the amount of 2,4-diamino-6-diallylamino-1,3,5-triazine was changed to 3 parts by weight. (Film + substrate) was obtained.

  The obtained laminate was biaxially stretched 1.25 times at 140 ° C., and the optical properties after stretching were evaluated. The physical properties of the obtained laminate are shown below.

  The obtained laminate has a thickness of 180 μm, a light transmittance of 91.5%, a haze of 0.5%, and a three-dimensional refractive index of nx1 = 1.53098, ny1 = 1.53097, and nz1 = 1.52987. Rth = 198.9 m, Re = 1.8 nm. Furthermore, R450 / R589 which shows the wavelength dependence of phase difference amount was 1.07.

  As a result, the obtained laminate had a tendency of nx1≈ny1> nz1 more strongly than the laminate of only the Nn-hexylmaleimide polymer resin shown in Comparative Example 3, and the cyclic hydrocarbon compound Rth is rising. In addition, since the wavelength dependence is small, it can be said that a thin film is expected and it is more excellent as an optical compensation film.

Example 7
Except for changing the cyclic hydrocarbon compound to N, N ′, N ″ -triphenyl-1,3,5-benzenetriamine (compound of the general formula (4)), the width is the same as in Example 5. A laminate (coating film + substrate) having a thickness of 50 mm and a total thickness of 196 μm was obtained.

  The obtained laminate was biaxially stretched 1.25 times at 140 ° C., and the optical properties after stretching were evaluated. The physical properties of the obtained laminate are shown below.

  The obtained laminate has a thickness of 180 μm, a light transmittance of 91.7%, a haze of 0.6%, and a three-dimensional refractive index of nx1 = 1.53110, ny1 = 1.53108, and nz1 = 1.52965. Rth = 259.2 m and Re = 3.6 nm. Furthermore, R450 / R589 which shows the wavelength dependence of phase difference amount was 1.07.

  As a result, the obtained laminate had a tendency of nx1≈ny1> nz1 more strongly than the laminate of only the Nn-hexylmaleimide polymer resin shown in Comparative Example 3, and the cyclic hydrocarbon compound Rth is rising. In addition, since the wavelength dependence is small, it can be said that a thin film is expected and it is more excellent as an optical compensation film.

Example 8
A laminate having a width of 50 mm and a total thickness of 194 μm in the same manner as in Example 7 except that the amount of N, N ′, N ″ -triphenyl-1,3,5-benzenetriamine was changed to 3 parts by weight. (Coating film + substrate) was obtained.

  The obtained laminate was biaxially stretched 1.25 times at 140 ° C., and the optical properties after stretching were evaluated. The physical properties of the obtained laminate are shown below.

  The obtained laminate has a thickness of 180 μm, a light transmittance of 91.0%, a haze of 0.6%, and a three-dimensional refractive index of nx1 = 1.53162, ny1 = 1.53155, and nz1 = 1.52944. Rth = 386.1 m and Re = 12.6 nm. Furthermore, R450 / R589 which shows the wavelength dependence of phase difference amount was 1.05.

  As a result, the obtained laminate had a tendency of nx1≈ny1> nz1 more strongly than the laminate of only the Nn-hexylmaleimide polymer resin shown in Comparative Example 3, and the cyclic hydrocarbon compound Rth and R are rising. In addition, since the wavelength dependence is small, it can be said that a thin film is expected and it is more excellent as an optical compensation film.

Comparative Example 5
After adding 3 parts by weight of tri (2-ethylhexyl) phosphate that is not a cyclic hydrocarbon compound to 100 parts by weight of the Nn-butylmaleimide polymer resin, a solution prepared in the same manner as in Comparative Example 1, A laminate (coating film + base material) having a thickness of 62 μm was obtained in the same manner as in Comparative Example 1.

  The obtained coating film was uniaxially stretched 1.5 times at 150 ° C., and the optical properties after stretching were evaluated. The physical properties of the obtained coating film are shown below.

  The obtained coating film has a thickness of 50 μm, a light transmittance of 91.8%, a haze of 0.6%, and a three-dimensional refractive index of nx = 1.53005, ny = 1.500003, and nz = 1.52891. Yes, Rth = 56.5 m, Re = 1.0 nm. Furthermore, R450 / R589 which shows the wavelength dependence of phase difference amount was 1.06.

  As a result, the obtained coated film had a tendency of nx≈ny> nz not larger than the coated film of only the Nn-butylmaleimide polymer resin shown in Comparative Example 1, and the cyclic hydrocarbon There is no increase in Rth due to the use of a non-system compound. Therefore, it can be said that a compound that is not such a cyclic hydrocarbon compound and does not belong to any of the general formulas (2), (3), and (4) has no effect of increasing the Rth of the maleimide resin film. .

  Table 1 shows the evaluation results of the above optical characteristics.

Claims (12)

A maleimide resin, 2,4,6-trimercapto-1,3,5-triazine, 2, 4,6 Torianiriniru-1,3,5-triazine, 6- (dibutylamino) -2,4-dimercapto A biaxially stretched optical compensation film comprising a cyclic hydrocarbon compound selected from -1,3,5-triazine and 2,4-diamino-6-diallylamino-1,3,5-triazine, and an optical compensation film The x-axis and y-axis in the film plane are the stretching axis direction of the film, the z-axis is the out-of-plane direction perpendicular to the film axis, the refractive index in the x-axis direction is nx, the refractive index in the y-axis direction is ny, and the z-axis direction An optical compensation film, wherein a three-dimensional refractive index relationship when a refractive index is nz is nx≈ny> nz. 2. The optical compensation film according to claim 1, comprising a maleimide resin composed of an N-substituted maleimide residue unit represented by the following general formula (1).

(Here, R ₁ is a linear alkyl group having 1 to 18 carbon atoms, a branched alkyl group having 1 to 18 carbon atoms, a cyclic alkyl group having 1 to 18 carbon atoms, a halogen group, an ether group, an ester group, Represents an amide group.) 3. The optical compensation according to claim 1, wherein Rth (out-of-plane retardation amount) represented by the following general formula (5) when measured with light having a measurement wavelength of 589 nm is 50 to 2000 nm. film.
Rth = ((nx + ny) / 2−nz) × d (5)
(Here, d represents the film thickness (nm) of the optical compensation film.) The wavelength dependence (R450 / R589) of the phase difference indicated by the ratio of the phase difference (R450) measured at a measurement wavelength of 450 nm and the phase difference (R589) measured at a measurement wavelength of 589 nm is 1 The optical compensation film according to claim 1, wherein the optical compensation film is 1 or less. 5. The optical compensation film according to claim 1, which is an optical compensation film for a liquid crystal display element. 6. An optical compensation film comprising a laminate of the optical compensation film according to claim 1 and a substrate. The optical compensation film according to claim 6, wherein a substrate is laminated on a coating film made of a maleimide resin and a cyclic hydrocarbon compound, and biaxially stretched. The stretching axis direction of the laminate is the x1 axis and y1 axis in the film plane, the out-of-plane direction perpendicular to this is the z1 axis, the refractive index in the x1 axis direction is nx1, the refractive index in the y1 axis direction is ny1, and the z1 axis The optical compensation film according to claim 6 or 7, wherein a three-dimensional refractive index relationship when the refractive index in the direction is nz1 is nx1≈ny1> nz1. Maleimide resin and 2,4,6-trimercapto-1,3,5-triazine , 2,4,6-trianilinyl-1,3,5-triazine, 6- (dibutylamino) -2,4-dimercapto- A solution comprising a cyclic hydrocarbon compound selected from 1,3,5-triazine and 2,4-diamino-6-diallylamino-1,3,5-triazine is applied onto a substrate and dried. A method for producing an optical compensation film, wherein the obtained coating film is biaxially stretched. The method for producing an optical compensation film according to claim 9, wherein the maleimide resin solution is a solution of a maleimide resin comprising a maleimide residue unit represented by the general formula (1). A maleimide resin, 2,4,6-trimercapto-1,3,5-triazine, 2, 4,6 Torianiriniru-1,3,5-triazine, 6- (dibutylamino) -2,4-dimercapto A solution comprising a cyclic hydrocarbon compound selected from -1,3,5-triazine and 2,4-diamino-6-diallylamino-1,3,5-triazine is applied to a substrate and dried. A method for producing an optical compensation film, which is obtained by biaxially stretching the obtained laminate of a substrate and a coating film. The method for producing an optical compensation film according to claim 11, wherein the maleimide resin solution is a solution of a maleimide resin comprising a maleimide residue unit represented by the general formula (1).