JP2014005348A - Resin composition, and optical compensation film using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a resin composition which is suitable for optical compensation films; an optical compensation film which uses the resin composition and has excellent retardation characteristics; and a method for producing the optical compensation film.SOLUTION: The resin composition is provided. A resin component of the resin composition contains 30-99 wt.% of a cellulose resin represented by the specified general formula (1) and 70-1 wt.% of a fumaric acid diester polymer including 60 mol% or more of fumaric acid diester residue units. The resin composition contains 70-99.99 wt.% of the resin component and 0.01-30 wt.% of an additive that has an aromatic hydrocarbon ring or an aromatic heterocycle. Also provided are the optical compensation film using the resin composition, and the method for producing the optical compensation film. (In the formula, R, Rand Reach independently represent hydrogen or a C1-C12 acyl group.)

Description

  The present invention relates to a resin composition and an optical compensation film using the same, and more particularly to a resin composition and an optical compensation film for a liquid crystal display excellent in retardation characteristics.

  Liquid crystal displays are widely used as the most important display devices in the multimedia society, including cellular phones, computer monitors, laptop 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 contrast and compensating for color tone when viewed from the front or obliquely.

  There are many liquid crystal displays such as vertical alignment type (VA-LCD), in-plane alignment type liquid crystal (IPS-LCD), super twist nematic type liquid crystal (STN-LCD), reflection type liquid crystal display, and transflective type liquid crystal display. There is a method, and an optical compensation film suitable for the display is required.

  As a conventional optical compensation film, a stretched film made of cellulose resin, polycarbonate, cyclic polyolefin, or the like is used. In particular, a film made of a cellulose-based resin such as a triacetyl cellulose film is widely used because it has good adhesion to polyvinyl alcohol as a polarizer.

  However, an optical compensation film made of a cellulose resin has several problems. For example, a cellulose resin film is processed into an optical compensation film having a retardation value adapted to various displays by adjusting stretching conditions, but the three-dimensional film obtained by uniaxial or biaxial stretching of the cellulose resin film. In order to manufacture an optical compensation film having a refractive index of ny ≧ nx> nz and other three-dimensional refractive indexes, for example, a three-dimensional refractive index such as ny> nz> nx or ny = nz> nx. Requires a special stretching method such as attaching a heat-shrinkable film to one or both sides of the film, heat-stretching the laminate, and applying a shrinking force in the thickness direction of the polymer film, and the refractive index (position It is also difficult to control the phase difference value (see, for example, Patent Documents 1 to 3). Here, nx is the refractive index in the fast axis direction (the direction with the smallest refractive index) in the film surface, ny is the refractive index in the slow axis direction (the direction in which the refractive index is the largest) in the film surface, and nz is the film surface. The refractive index outside (thickness direction) is shown.

  Cellulosic resin films are generally produced by a solvent casting method. Since a cellulose resin film formed by a casting method has an out-of-plane retardation (Rth) of about 40 nm in the film thickness direction, IPS mode liquid crystal There are problems such as color shift in displays. Here, the out-of-plane phase difference (Rth) is a phase difference value represented by the following equation.

Rth = [(nx + ny) / 2−nz] × d
(Where nx is the refractive index in the fast axis direction in the film plane, ny is the refractive index in the slow axis direction in the film plane, nz is the refractive index outside the film plane, and d is the film thickness). )
Moreover, the retardation film which consists of a fumarate ester-type resin is proposed (for example, refer patent document 4).

  However, the three-dimensional refractive index of the stretched film made of a fumarate ester resin is nz> ny> nx, and in order to obtain an optical compensation film exhibiting the above three-dimensional refractive index, it is laminated with another optical compensation film or the like. Etc. are necessary.

Japanese Patent No. 2818983 JP-A-5-297223 JP-A-5-323120 JP 2008-64817 A

  The present invention has been made in view of the above problems, and an object thereof is to provide a resin composition suitable for an optical compensation film and an optical compensation film having excellent retardation characteristics using the resin composition.

  As a result of intensive studies to solve the above problems, the present inventors have obtained a resin composition containing a cellulose resin, a fumaric acid diester polymer, and an additive having an aromatic hydrocarbon ring or an aromatic heterocycle, The present inventors have found that an optical compensation film using the same and a method for producing the same can solve the above-mentioned problems, and have completed the present invention. That is, the present invention provides a fumaric acid diester polymer 99-1 containing 10 to 99% by weight of a cellulose-based resin represented by a predetermined formula as a resin component and 60 mol% or more of a fumaric acid diester residue unit represented by the predetermined formula. A resin comprising 70% to 99.99% by weight of the resin component and 0.01 to 30% by weight of an additive having an aromatic hydrocarbon ring or an aromatic heterocyclic ring. A composition, an optical compensation film using the composition, and a method for producing the same.

  Hereinafter, the present invention will be described in detail.

  The resin composition of the present invention contains 10 to 99% by weight of a cellulose-based resin represented by the following general formula (1) and 60 mol% or more of a fumaric acid diester residue unit represented by the following general formula (2) as a resin component. Containing 90 to 1% by weight of a fumaric acid diester polymer, and further containing 0.01 to 30% by weight of the resin component 70 to 99.99% by weight and an aromatic hydrocarbon ring or aromatic heterocycle contains.

（式中、Ｒ_１、Ｒ_２、Ｒ_３はそれぞれ独立して水素又は炭素数１〜１２のアシル基を示す。）

_{(Wherein, R 1, R 2, R} 3 each independently represent hydrogen or an acyl group having 1 to 12 carbon atoms.)

（式中、Ｒ_４、Ｒ_５はそれぞれ独立して炭素数１〜１２のアルキル基を示す。）
本発明の樹脂組成物が含有するセルロース系樹脂は、β−グルコース単位が直鎖状に重合した高分子であり、グルコース単位の２位、３位および６位の水酸基の一部または全部をアシル基によりエステル化したポリマーであり、例えば、セルロースアセテート、セルロースプロピオネート、セルロースブチレート、セルロースアセテートブチレート等が挙げられる。

(In formula, R < ₄ >, R < ₅ > shows a C1-C12 alkyl group each independently.)
The cellulosic resin contained in the resin composition of the present invention is a polymer in which β-glucose units are linearly polymerized, and some or all of the hydroxyl groups at the 2nd, 3rd and 6th positions of the glucose unit are acylated. Examples of the polymer esterified with a group include cellulose acetate, cellulose propionate, cellulose butyrate, and cellulose acetate butyrate.

  The degree of acylation means the proportion of the hydroxyl groups of cellulose esterified at each of the 2-position, 3-position and 6-position (100% esterification has a degree of substitution of 1). Preferably it is 1.5 <= DS <= 3.0, More preferably, it is 1.8-2.8. The cellulose resin preferably has an acyl group having 2 to 12 carbon atoms as a substituent. Examples of the acyl group having 2 to 12 carbon atoms include acetyl group, propionyl group, butyryl group, heptanoyl group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, isobutanoyl group, t-butyryl group, cyclohexanecarbonyl group, benzoyl group Group, naphthylcarbonyl group, cinnamoyl group and the like. Among these, an acetyl group, a propionyl group, and a butyryl group, which are acyl groups having 2 to 5 carbon atoms, are particularly preferable. Only one type of acyl group may be used in the cellulose resin used in the present invention, or two or more types of acyl groups may be used. When two or more types of acyl groups are used, one of them is preferably an acetyl group.

In the acylation of the cellulose resin, when an acid anhydride or acid chloride is used as an acylating agent, an organic acid such as acetic acid or methylene chloride is used as an organic solvent as a reaction solvent. As the catalyst, when the acylating agent is an acid anhydride, a protic catalyst such as sulfuric acid is preferably used, and when the acylating agent is an acid chloride (for example, CH ₃ CH ₂ COCl), Basic compounds are preferably used. The most common industrial synthesis method for mixed fatty acid esters of cellulose is to use cellulose mixed fatty acids containing fatty acids (acetic acid, propionic acid, valeric acid, etc.) corresponding to acetyl groups and other acyl groups or anhydrides thereof. This is a method of acylating with components.

The cellulosic resin preferably has a standard polystyrene equivalent number average molecular weight (Mn) of 1 × 10 ³ to 1 × 10 ⁶ obtained from an elution curve measured by gel permeation chromatography (GPC). It is more preferably 1 × 10 ⁴ to 2 × 10 ⁵ because it has excellent mechanical properties and excellent moldability during film formation.

The fumaric acid diester polymer (hereinafter referred to as fumaric acid diester polymer) contained in the resin composition of the present invention contains 60 mol% or more of the fumaric acid diester residue unit represented by the general formula (2). It is preferable that 75 mol% or more of the fumaric acid diester residue unit represented by the general formula (2) is included. Examples of the fumaric acid diester polymer include diisopropyl fumarate polymer, dicyclohexyl fumarate polymer, diisopropyl fumarate / diethyl fumarate copolymer, and the like. When the fumaric acid diester residue unit represented by the general formula (2) is less than 60 mol%, the expression of retardation is lowered. R ₄ and R ₅ which are ester substituents of the fumaric acid diester residue unit are alkyl groups having 1 to 12 carbon atoms, for example, methyl group, ethyl group, propyl group, isopropyl group, s-butyl group, t -Butyl group, s-pentyl group, t-pentyl group, s-hexyl group, t-hexyl group, 2-ethylhexyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group and the like. Examples of the fumarate diester residue unit represented by the general formula (2) include, for example, dimethyl fumarate residue, diethyl fumarate residue, di-n-propyl fumarate residue, diisopropyl fumarate residue, dimer fumarate. -N-butyl residue, di-s-butyl fumarate residue, di-t-butyl fumarate residue, di-n-pentyl fumarate residue, di-s-pentyl fumarate residue, di-fumarate -T-pentyl residue, di-n-hexyl fumarate residue, di-s-hexyl fumarate residue, di-t-hexyl fumarate residue, di-2-ethylhexyl fumarate, dicyclopropyl fumarate Examples include a residue, a dicyclopentyl fumarate residue, a dicyclohexyl fumarate residue, etc. Among them, a diisopropyl fumarate residue is preferable. The fumaric acid diester polymer comprises diisopropyl fumarate residue units of 60 to 95 mol%, diethyl fumarate residue units, di-n-propyl fumarate residue units, di-n-butyl fumarate residue units, fumaric acid A copolymer containing 5 to 40 mol% of a fumaric acid diester residue unit selected from di-2-ethylhexyl residue units is preferred.

  The fumaric acid diester polymer is 60 mol% or more of the fumaric acid diester residue unit represented by the general formula (2), and includes 40 mol% or less of the monomer residue unit copolymerizable with the fumaric acid diester. It is more preferable that the fumaric acid diester residue unit is 75 mol% or more. Residue units of monomers copolymerizable with fumaric acid diesters include, for example, styrene residues such as styrene residues and α-methylstyrene residues; acrylic acid residues; methyl acrylate residues, acrylic Acrylic acid residues such as ethyl acid residues and butyl acrylate residues; methacrylic acid residues; methacrylic acid ester residues such as methyl methacrylate residues, ethyl methacrylate residues and butyl methacrylate residues; Vinyl ester residues such as vinyl acetate residues and vinyl propionate residues; acrylonitrile residues; methacrylonitrile residues; olefin residues such as ethylene residues and propylene residues, vinyl pyrrolidone residues, vinyl pyridine residues 1 type or 2 types or more, such as group, can be mentioned.

The fumaric acid diester polymer has a number average molecular weight (Mn) in terms of standard polystyrene of 1 × 10 ^{3 to} 5 × 10 ⁶ obtained from an elution curve measured by gel permeation chromatography (GPC). Particularly, it is preferably 1 × 10 ⁴ to 2 × 10 ⁵ because it is excellent in mechanical properties and excellent in moldability during film formation.

  The ratio of the composition of the cellulose resin and the fumaric acid diester polymer in the resin composition of the present invention is 10 to 99% by weight of the cellulose resin and 90 to 1% by weight of the fumaric acid diester polymer. When the cellulosic resin is less than 10% by weight (when the fumaric acid diester polymer exceeds 90% by weight), or when the cellulosic resin exceeds 99% by weight (when the fumaric acid diester polymer is less than 1% by weight) It is difficult to control the phase difference. The content is preferably 30 to 97% by weight of a cellulose resin and 70 to 3% by weight of a fumaric acid diester polymer, more preferably 50 to 95% by weight of a cellulose resin and 50 to 5% by weight of a fumaric acid diester polymer.

  The fumaric acid diester polymer may be produced by any method as long as the fumaric acid diester polymer is obtained. For example, fumaric acid diesters may be copolymerized with fumaric acid diesters. It can be produced by using a monomer together and performing radical polymerization. Examples of the fumaric acid diesters include dimethyl fumarate, diethyl fumarate, di-n-propyl fumarate, diisopropyl fumarate, di-n-butyl fumarate, di-s-butyl fumarate, and fumaric acid. Di-t-butyl, di-s-pentyl fumarate, di-t-pentyl fumarate, di-s-hexyl fumarate, di-t-hexyl fumarate, di-2-ethylhexyl fumarate, dicyclofumarate Examples thereof include propyl, dicyclopentyl fumarate, and dicyclohexyl fumarate. Examples of the monomer copolymerizable with fumaric acid diester include styrenes such as styrene and α-methylstyrene; acrylic acid; methyl acrylate, acrylic Acrylic acid esters such as ethyl acrylate and butyl acrylate; methacrylic acid; methyl methacrylate, methacrylic acid Methacrylic acid esters such as ethyl and butyl methacrylate; Vinyl esters such as vinyl acetate and vinyl propionate; Acrylonitrile; Methacrylonitrile; Olefins such as ethylene and propylene; Vinyl pyrrolidone; One or two kinds such as vinyl pyridine The above can be mentioned.

  As the radical polymerization method, 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 employed.

  Examples of the polymerization initiator used for radical polymerization include benzoyl peroxide, lauryl peroxide, octanoyl peroxide, acetyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, and dicumyl peroxide. Organic peroxides such as 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-butyronitrile), 2,2′-azobisisobutyronitrile, dimethyl-2 Azo initiators such as 1,2′-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 solution polymerization method or precipitation polymerization method, For example, aromatic solvents, such as benzene, toluene, xylene; Alcohol solvents, such as methanol, ethanol, propyl alcohol, and butyl alcohol; Cyclohexane, Examples thereof include dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, dimethylformamide, isopropyl acetate, and a mixed solvent 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 30-150 degreeC.

The additive having an aromatic hydrocarbon ring or aromatic heterocycle contained in the resin composition of the present invention is not particularly limited with respect to the birefringence Δn represented by the following formula (1),
Since it becomes an optical compensation film excellent in optical characteristics, it is preferably 0.05 or more, more preferably 0.05 to 0.5, and particularly preferably 0.1 to 0.5. The Δn of the additive can be obtained by molecular orbital calculation.

Δn = ny−nx (1)
(In the formula, nx represents the refractive index in the fast axis direction of the additive molecule, and ny represents the refractive index in the slow axis direction of the additive molecule.)
The additive having an aromatic hydrocarbon ring or aromatic heterocycle in the resin composition of the present invention is not particularly limited as to the number of aromatic hydrocarbon rings or aromatic heterocycles in the molecule, but optical Since it becomes an optical compensation film excellent in characteristics, the number is preferably 1 to 12, and more preferably 1 to 8. Examples of the aromatic hydrocarbon ring include a 5-membered ring, a 6-membered ring, a 7-membered ring, or a condensed ring composed of two or more aromatic rings. Examples of the aromatic heterocycle include a furan ring. Thiophene ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, triazole ring, pyridine ring, pyrimidine ring, pyrazine ring, 1,3,5-triazine ring and the like.

  The aromatic hydrocarbon ring or aromatic heterocycle may have a substituent. Examples of the substituent include a hydroxyl group, an ether group, a carbonyl group, an ester group, a carboxylic acid residue, an amino group, and an imino group. Amide group, imide group, cyano group, nitro group, sulfonyl group, sulfonic acid residue, phosphonyl group, phosphonic acid residue and the like.

  Examples of the additive having an aromatic hydrocarbon ring or aromatic heterocycle used in the present invention include tricresyl phosphate, trixylenyl phosphate, triphenyl phosphate, 2-ethylhexyl diphenyl phosphate, cresyl diphenyl phosphate, and bisphenol. Phosphoric ester compounds such as A bis (diphenyl phosphate), dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dinormal octyl phthalate, 2-ethylhexyl phthalate, diisooctyl phthalate, dicapryl phthalate, dinonyl phthalate, diisononyl phthalate , Phthalate compounds such as didecyl phthalate and diisodecyl phthalate, tributyl trimellitate, tri-normal hexyl Trimellitic acid ester compounds such as rimerimate, tri (2-ethylhexyl) trimellitate, tri-normal octyl trimellitate, tri-isooctyl trimellitate, tri-isodecyl trimellitate, tri (2-ethylhexyl) pyromellitate, Pyromellitic acid such as tetrabutyl pyromellitate, tetra-normal hexyl pyromellitate, tetra (2-ethylhexyl) pyromellitate, tetra-normal octyl pyromellitate, tetra-isooctyl pyromellitate, tetra-isodecyl pyromellitate Ester compounds, benzoic acid ester compounds such as ethyl benzoate, isopropyl benzoate, ethyl paraoxybenzoate, phenyl salicylate, p-octylphenyl salicylate, p-tert-butylphenyl Salicylic acid ester compounds such as ricylate, glycolic acid ester compounds such as methyl phthalyl ethyl glycolate, ethyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, 2- (2′-hydroxy-5′-t-butyl) Benzotriazole compounds such as phenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) benzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,2′-dihydroxy Benzophenone compounds such as -4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, sulfonamide compounds such as N-benzenesulfonamide, 2,4-diphenyl-6 -(2-hydroxy- 4-methoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-ethoxyphenyl) -1,3,5-triazine, 2,4-diphenyl- (2- And triazine compounds such as hydroxy-4-propoxyphenyl) -1,3,5-triazine, 2,4-diphenyl- (2-hydroxy-4-butoxyphenyl) -1,3,5-triazine, and the like. Preferably, tricresyl phosphate, 2-ethylhexyl diphenyl phosphate, 2-hydroxy-4-methoxybenzophenone and the like can be mentioned, and these can be used alone or in combination of two or more.

  The ratio of the additive having an aromatic hydrocarbon ring or aromatic heterocycle in the resin composition of the present invention is 0.01 to 30% by weight (the above resin component: 70 to 99.99% by weight), preferably Is 0.5 to 20% by weight, more preferably 1 to 15% by weight. When it is less than 0.01% by weight, the optical properties are inferior, and when it exceeds 30% by weight, the mechanical properties are inferior.

  The resin composition of the present invention may contain an antioxidant in order to improve the thermal stability. Antioxidants include, for example, hindered phenol antioxidants, phosphorus antioxidants, sulfur antioxidants, lactone antioxidants, amine antioxidants, hydroxylamine antioxidants, vitamin E series Antioxidants and other antioxidants may be mentioned, and these antioxidants may be used alone or in combination of two or more.

  The resin composition of the present invention may contain a hindered amine light stabilizer or an ultraviolet absorber in order to improve the weather resistance. Examples of the ultraviolet absorber include benzotriazole, benzophenone, triazine, benzoate and the like.

  The resin composition of the present invention contains other polymers, surfactants, polymer electrolytes, conductive complexes, pigments, dyes, antistatic agents, antiblocking agents, lubricants, etc., as long as the gist of the invention is not exceeded. May be.

  The resin composition of the present invention can be obtained by blending a cellulosic resin, a fumaric acid diester polymer, and an additive having an aromatic hydrocarbon ring or an aromatic heterocycle.

  As a blending method, methods such as melt blending and solution blending can be used. The melt blending method is a method of manufacturing by melting and kneading a resin and an additive having an aromatic hydrocarbon ring or aromatic heterocycle by heating. The solution blending method is a method in which a resin and an additive having an aromatic hydrocarbon ring or aromatic heterocycle are dissolved in a solvent and blended. Solvents used for solution blending include chlorinated solvents such as methylene chloride and chloroform, aromatic solvents such as toluene and xylene, alcohol solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol and propanol, dimethylformamide, and N-methyl. Pyrrolidone or the like can be used. It is also possible to blend after dissolving each resin and an additive having an aromatic hydrocarbon ring or aromatic heterocycle in a solvent, and it is also possible to dissolve each resin powder, pellets, etc. in a solvent after kneading. Is possible. The obtained blended resin solution can be put into a poor solvent to precipitate the resin composition, or it can be used in the production of an optical compensation film as it is.

  The ratio of the cellulose-based resin, the fumaric acid diester polymer, and the additive having an aromatic hydrocarbon ring or aromatic heterocycle during blending is 10 to 99% by weight of cellulose-based resin: fumaric acid diester polymer: 90 Resin component (cellulosic resin and fumaric acid diester polymer): 70 to 99.99% by weight of an additive having an aromatic hydrocarbon ring or aromatic heterocycle: 0.01 to 30 % By weight. When the ratio of the additive is out of this range, it may be difficult to control the phase difference.

  The optical compensation film using the resin composition of the present invention has a thickness of 5 to 200 μm, preferably 10 to 100 μm, more preferably 30 to 80 μm, and particularly preferably 30 to 75 μm. When the thickness is less than 5 μm, it may be difficult to handle the film, and when it exceeds 200 μm, the optical member may not be suitable for thinning.

  The retardation characteristics of the optical compensation film using the resin composition of the present invention vary depending on the target optical compensation film, and 1) preferably the in-plane retardation (Re) represented by the following formula (2): 80 to 300 nm, more preferably 100 to 300 nm, particularly preferably 200 to 280 nm, and the Nz coefficient represented by the following formula (3) is preferably 0.35 to 0.65, more preferably 0.45 to 0 2) The in-plane retardation (Re) is preferably 50 to 200 nm, more preferably 80 to 160 nm, and the Nz coefficient is preferably −0.2 to 0.2, more preferably − 3) The in-plane retardation (Re) is preferably 0 to 20 nm, more preferably 0 to 5 nm, and the out-of-plane retardation (Rth) represented by the following formula (4) is preferably 0.1 to 0.1. Good It is properly -150～10Nm, more preferably from -120～0Nm. The measurement was performed using a fully automatic birefringence meter (trade name: KOBRA-21ADH, manufactured by Oji Scientific Instruments Co., Ltd.) under the measurement wavelength of 589 nm.

  These have retardation characteristics that are difficult to develop with conventional optical compensation films using cellulose resins.

Re = (ny−nx) × d (2)
Nz = (ny−nz) / (ny−nx) (3)
Rth = [(nx + ny) / 2−nz] × d (4)
(Where nx represents the refractive index in the fast axis direction in the film plane, ny represents the refractive index in the slow axis direction in the film plane, nz represents the refractive index outside the film plane, and d represents the film. Indicates thickness.)
The optical compensation film of the present invention has a light transmittance of preferably 85% or more, and more preferably 90% or more, for improving luminance.

  The optical compensation film of the present invention has a haze of preferably 2% or less, more preferably 1% or less, for improving contrast.

  As a method for producing an optical compensation film using the resin composition of the present invention, any method may be used as long as the optical compensation film of the present invention can be produced. Since an excellent optical compensation film can be obtained, it is preferably produced by a solution casting method. Here, the solution casting method is a method of obtaining an optical compensation film by casting a resin solution (generally referred to as a dope) on a support substrate and then evaporating the solvent by heating. As a casting method, for example, a T-die method, a doctor blade method, a bar coater method, a roll coater method, a lip coater method, or the like is used. The method of continuous extrusion is most commonly used. Examples of the support substrate used include a glass substrate, a metal substrate such as stainless steel and ferrotype, and a plastic substrate such as polyethylene terephthalate. In order to industrially continuously form a substrate having high surface properties and optical homogeneity, a metal substrate having a mirror-finished surface is preferably used. In the solution casting method, the viscosity of the resin solution is an extremely important factor when producing an optical compensation film with excellent thickness accuracy and surface smoothness. The viscosity of the resin solution is the resin concentration, molecular weight, and type of solvent. It depends on. A resin solution for producing an optical compensation film using the resin composition of the present invention is prepared by dissolving a cellulose resin and a fumaric acid diester polymer in a solvent. The viscosity of the resin solution can be adjusted by the molecular weight of the polymer, the concentration of the polymer, and the type of solvent. The viscosity of the resin solution is not particularly limited, but is preferably 100 to 10000 cps, more preferably 300 to 5000 cps, and particularly preferably 500 to 3000 cps in order to make film coating easier.

  Examples of the method for producing an optical compensation film using the resin composition of the present invention include 10 to 99% by weight of a cellulose-based resin represented by the following general formula (1) as a resin component and the following general formula (2). Additive having 90 to 1% by weight of fumaric acid diester polymer containing 60 mol% or more of fumaric acid diester residue unit, 70 to 99.99% by weight of the resin component and an aromatic hydrocarbon ring or aromatic heterocycle For example, 0.01 to 30% by weight is dissolved in a solvent, and the resulting resin solution is cast onto a substrate, dried, and then peeled off from the substrate.

（式中、Ｒ_１、Ｒ_２、Ｒ_３はそれぞれ独立して水素又は炭素数１〜１２のアシル基を示す。）

_{(Wherein, R 1, R 2, R} 3 each independently represent hydrogen or an acyl group having 1 to 12 carbon atoms.)

（式中、Ｒ_４、Ｒ_５はそれぞれ独立して炭素数１〜１２のアルキル基を示す。）
本発明の樹脂組成物を用いて得られた光学補償フィルムは、面内位相差（Ｒｅ）を発現するために一軸延伸またはアンバランス二軸延伸することが好ましい。光学補償フィルムを延伸する方法としては、ロール延伸による縦一軸延伸法やテンター延伸による横一軸延伸法、これらの組み合わせによるアンバランス逐次二軸延伸法やアンバランス同時二軸延伸法等を用いることができる。また本発明では、熱収縮性フィルムの収縮力の作用下に延伸を行う特殊延伸法を用いずに位相差特性を発現させることができる。

(In formula, R < ₄ >, R < ₅ > shows a C1-C12 alkyl group each independently.)
The optical compensation film obtained using the resin composition of the present invention is preferably uniaxially stretched or unbalanced biaxially stretched in order to develop in-plane retardation (Re). As a method for stretching the optical compensation film, it is possible to use a longitudinal uniaxial stretching method by roll stretching, a transverse uniaxial stretching method by tenter stretching, an unbalanced sequential biaxial stretching method or an unbalanced simultaneous biaxial stretching method by a combination thereof. it can. Moreover, in this invention, a phase difference characteristic can be expressed, without using the special extending | stretching method which extends | stretches under the effect | action of the shrinkage force of a heat-shrinkable film.

  The thickness of the optical compensation film at the time of stretching is 40 to 200 μm, preferably 50 to 180 μm, more preferably 60 to 160 μm. If the thickness is less than 40 μm, stretching may be difficult, and if it exceeds 200 μm, the optical member may not be suitable for thinning.

  The stretching temperature is not particularly limited, but is preferably 50 to 200 ° C., more preferably 100 to 160 ° C., because good retardation characteristics can be obtained. Although there is no restriction | limiting in particular in the draw ratio of uniaxial stretching, since a favorable phase difference characteristic is acquired, 1.05-3 times are preferable and 1.1-2.0 times are further more preferable. Although there is no restriction | limiting in particular in the draw ratio of unbalance biaxial stretching, since it becomes an optical compensation film excellent in the optical characteristic, 1.05 to 3 times are preferable in the length direction, and 1.1 to 2.0 times are preferable. Furthermore, since it becomes an optical compensation film excellent in optical characteristics, 1.01 to 1.2 times is preferable in the width direction, and 1.05 to 1.1 times is more preferable. The in-plane retardation (Re) can be controlled by the stretching temperature and the stretching ratio.

  The optical compensation film using the resin composition of the present invention can be laminated with a film containing another resin as necessary. Examples of other resins include polyether sulfone, polyarylate, polyethylene terephthalate, polynaphthalene terephthalate, polycarbonate, cyclic polyolefin, maleimide resin, fluorine resin, polyimide, and the like. It is also possible to laminate a hard coat layer or a gas barrier layer.

  An optical compensation film using the resin composition of the present invention is useful as an optical compensation film for liquid crystal displays or an antireflection film because it is a thin film and exhibits specific retardation characteristics.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.

  In addition, the various physical properties shown by an Example were measured with the following method.

<Analysis of polymer>
The structural analysis of the polymer was determined by proton nuclear magnetic resonance spectroscopy ( ¹ H-NMR) spectrum analysis using a nuclear magnetic resonance measuring apparatus (manufactured by JEOL, trade name: JNM-GX270).

<Measurement of number average molecular weight>
Using a gel permeation chromatography (GPC) apparatus (trade name: C0-8011 (manufactured by Tosoh Corporation, column GMH _HR- H)), tetrahydrofuran or dimethylformamide as a solvent, measurement at 40 ° C., standard polystyrene Calculated as a converted value.

<Measurement of light transmittance and haze of optical compensation film>
The light transmittance and haze of the film produced were measured using a haze meter (trade name: NDH2000, manufactured by Nippon Denshoku Industries Co., Ltd.). The light transmittance was measured according to JIS K 7361-1 (1997 edition). Measurements were made in accordance with JIS-K 7136 (2000 version).

<Measurement of phase difference characteristics>
The retardation characteristic of the optical compensation film was measured using a sample tilt type automatic birefringence meter (manufactured by Oji Scientific Instruments, trade name: KOBRA-WR) using light with a wavelength of 589 nm.

Synthesis example 1
Into a 5 liter autoclave, 2400 g of distilled water containing 0.2% by weight of hydroxypropylmethylcellulose, 1388 g of diisopropyl fumarate, 212 g of diethyl fumarate, 12.7 g of a polymerization initiator (trade name: manufactured by NOF Corporation, perbutyl PV) are prepared. The suspension radical polymerization reaction was carried out under conditions of a polymerization temperature of 48 ° C. and a polymerization time of 30 hours. The obtained polymer particles were recovered by filtration, washed thoroughly with water and methanol, and dried at 80 ° C. to obtain a diisopropyl fumarate / diethyl fumarate polymer. The number average molecular weight of the obtained diisopropyl fumarate / diethyl fumarate polymer was 98,000, 83 mol% diisopropyl fumarate units, and 17 mol% diethyl fumarate units.

Synthesis example 2
In a 5 liter autoclave, 2600 g of distilled water containing 0.2% by weight of hydroxypropylmethylcellulose, 1232 g of diisopropyl fumarate, 168 g of di-n-butyl fumarate, 11 g of a polymerization initiator (manufactured by NOF Corporation, trade name: perbutyl PV) The suspension radical polymerization reaction was carried out under conditions of charging, polymerization temperature 47 ° C., and polymerization time 36 hours. The obtained polymer particles were collected by filtration, washed thoroughly with water and methanol, and dried at 80 ° C. to obtain a diisopropyl fumarate / di-n-butyl fumarate polymer. The number average molecular weight of the obtained polymer was 88000, diisopropyl fumarate unit 88 mol%, and di-n-butyl fumarate unit 12 mol%.

Synthesis example 3
In a 5 liter autoclave, 2600 g of distilled water containing 0.2% by weight of hydroxypropyl methylcellulose, 1200 g of diisopropyl fumarate, 184 g of di-2-ethylhexyl fumarate, 11 g of a polymerization initiator (manufactured by NOF Corporation, trade name: perbutyl PV) The suspension radical polymerization reaction was carried out under conditions of charging, polymerization temperature 47 ° C., and polymerization time 36 hours. The obtained polymer particles were collected by filtration, washed thoroughly with water and methanol, and dried at 80 ° C. to obtain a diisopropyl fumarate / di-n-butyl fumarate polymer. The number average molecular weight of the obtained polymer was 85000, diisopropyl fumarate unit 92.5 mol%, and di-n-butyl fumarate unit 7.5 mol%.

Synthesis example 4
In a 1 liter autoclave, 200 g of diisopropyl fumarate, 17 g of diethyl fumarate, 32 g of vinylpyrrolidone, and 0.2 g of a polymerization initiator (manufactured by NOF Corporation, trade name: perbutyl PV) were charged at a polymerization temperature of 45 ° C. and a polymerization time of 8 hours. A radical polymerization reaction was performed under the conditions. The solution containing the obtained polymer was added to a large excess of methanol to precipitate the polymer. The obtained polymer was filtered and dried at 80 ° C. to obtain a diisopropyl fumarate / diethyl fumarate / vinylpyrrolidone polymer. The number average molecular weight of the obtained polymer was 45000, diisopropyl fumarate unit 80 mol%, diethyl fumarate unit 6 mol%, and vinylpyrrolidone unit 14 mol%.

Example 1
130 g of cellulose butyrate (butyryl group = 82 mol%, total substitution degree DS = 2.46, number average molecular weight = 70,000), 30 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and triclet 10 g of zirconium phosphate (Δn = 0.18) was dissolved in 640 g of methylene chloride. The dissolved material is cast onto a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 150 μm. [Resin component (cellulose butyrate: 81% by weight, diisopropyl fumarate / diethyl fumarate polymer: 19% by weight): 94% by weight, tricresyl phosphate: 6% by weight]. The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. to a length of 1.5 times and a width of 1.1 times (thickness after stretching: 122 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are shown in Table 1.

得られた光学補償フィルムは全光線透過率が高く透明性に優れる、ヘーズが小さい、面内位相差（Ｒｅ）およびＮｚ係数が目的とする光学特性を有するものであった。

The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 2
130 g of cellulose acetate butyrate (acetyl group = 15 mol%, butyryl group = 70 mol%, total substitution degree DS = 2.55, number average molecular weight = 72,000), diisopropyl fumarate obtained by Synthesis Example 4 30 g of diethyl vinylpyrrolidone acid polymer and 10 g of tricresyl phosphate (Δn = 0.18) were dissolved in 640 g of methylene chloride. The dissolved material is cast onto a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 150 μm. [Resin component (cellulose acetate butyrate: 81 wt%, diisopropyl fumarate / diethyl fumarate / vinyl pyrrolidone polymer: 19 wt%): 94 wt%, tricresyl phosphate: 6 wt%]. The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. to a length of 1.5 times and a width of 1.1 times (thickness after stretching: 123 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 3
158 g of cellulose butyrate (butyryl group = 87 mol%, total substitution degree DS = 2.61, number average molecular weight = 70,000), 12 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and 2- 10 g of ethylhexyl diphenyl phosphate (Δn = 0.23) was dissolved in 800 g of methyl ethyl ketone. The dissolved material is cast onto a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 150 μm. [Resin component (cellulose butyrate: 93 wt%, diisopropyl fumarate / diethyl fumarate polymer: 7 wt%): 95 wt%, 2-ethylhexyl diphenyl phosphate: 5 wt%]. The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. to 1.5 times in length and 1.1 times in width (125 μm thickness after stretching).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 4
138 g of cellulose butyrate (butyryl group = 86 mol%, total substitution degree DS = 2.58, number average molecular weight = 70,000), 32 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and 2- 10 g of hydroxy-4-methoxybenzophenone (Δn = 0.11) was dissolved in 800 g of methyl ethyl ketone. The dissolved material is cast onto a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 150 μm. [Resin component (cellulose butyrate: 80 wt%, diisopropyl fumarate / diethyl fumarate polymer: 20 wt%): 94 wt%, 2-hydroxy-4-methoxybenzophenone: 6 wt%]. The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. to 1.5 times in length and 1.1 times in width (thickness after stretching 120 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 5
54 g of cellulose acetate propionate (acetyl group = 5 mol%, propionyl group = 80 mol%, total substitution degree DS = 2.55, number average molecular weight = 75,000), diisopropyl fumarate obtained in Synthesis Example 3 116 g of di-2-ethylhexyl fumarate polymer and 10 g of tricresyl phosphate (Δn = 0.18) were dissolved in 800 g of methyl ethyl ketone. The dissolved material is cast on a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 180 μm. [Resin component (cellulose acetate propionate: 32% by weight, diisopropyl fumarate / di-2-ethylhexyl fumarate polymer: 68% by weight): 94% by weight, tricresyl phosphate: 6% by weight] . The obtained optical compensation film was cut into a 50 mm square, and stretched at 125 ° C. to a length of 1.25 times and a width of 1.05 times (thickness after stretching 160 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 6
153 g of cellulose butyrate (butyryl group = 82 mol%, total substitution DS = 2.46, number average molecular weight = 70,000), 17 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and triclet 20 g of zilphate (Δn = 0.18) was dissolved in 800 g of methylene chloride. The dissolved material is cast onto a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 150 μm. [Resin component (cellulose butyrate: 90% by weight, diisopropyl fumarate / diethyl fumarate polymer: 10% by weight): 89% by weight, tricresyl phosphate: 11% by weight]. The obtained optical compensation film was cut into a 50 mm square, and stretched at 125 ° C. in length 2.0 times and width 1.1 times (thickness after stretching 106 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 7
153 g of cellulose butyrate (butyryl group = 82 mol%, total substitution DS = 2.46, number average molecular weight = 70,000), 17 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and triclet 10 g of zilphate (Δn = 0.18) was dissolved in 800 g of methylene chloride. The dissolved material is cast on a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 80 μm. [Resin component (cellulose butyrate: 90 wt%, diisopropyl fumarate / diethyl fumarate polymer: 10 wt%): 94 wt%, tricresyl phosphate: 6 wt%].

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film has high light transmittance and excellent transparency, low haze, in-plane retardation (Re) and out-of-plane retardation (Rth) in the thickness direction have the desired optical characteristics. there were.

Example 8
153 g of cellulose butyrate (butyryl group = 86 mol%, total substitution degree DS = 2.58, number average molecular weight = 70,000), 17 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and triclet 20 g of zilphate (Δn = 0.18) was dissolved in 800 g of methylene chloride. The dissolved material is cast on a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 100 μm. [Resin component (cellulose butyrate: 90% by weight, diisopropyl fumarate / diethyl fumarate polymer: 10% by weight): 89% by weight, tricresyl phosphate: 11% by weight]. The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. to 2.0 times in length and 1.1 times in width (thickness after stretching 70 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 9
171 g of cellulose butyrate (butyryl group = 86 mol%, total substitution degree DS = 2.58, number average molecular weight = 70,000), 9 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and triclet 20 g of zilphate (Δn = 0.18) was dissolved in 800 g of methylene chloride. The dissolved material is cast on a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 100 μm. [Resin component (cellulose butyrate: 95% by weight, diisopropyl fumarate / diethyl fumarate polymer: 5% by weight): 90% by weight, tricresyl phosphate: 10% by weight]. The obtained optical compensation film was cut into a 50 mm square and uniaxially stretched 2.0 times in length at 125 ° C. (thickness after stretching 70 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 10
130 g of cellulose butyrate (butyryl group = 82 mol%, total substitution degree DS = 2.46, number average molecular weight = 70,000), 30 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and tributyltri 10 g of meritate (Δn = 0.11) was dissolved in 800 g of methylene chloride. The dissolved material is cast on a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 180 μm. [Resin component (cellulose butyrate: 81 wt%, diisopropyl fumarate / diethyl fumarate polymer: 19 wt%): 94 wt%, tributyl trimellitate: 6 wt%]. The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. by 1.5 times in length and 1.1 times in width (thickness after stretching: 145 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 11
130 g of cellulose butyrate (butyryl group = 82 mol%, total substitution degree DS = 2.46, number average molecular weight = 70,000), 30 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and tetrabutyl 10 g of pyromellitate (Δn = 0.13) was dissolved in 800 g of methylene chloride. The dissolved material is cast on a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 180 μm. [Resin component (cellulose butyrate: 81 wt%, diisopropyl fumarate / diethyl fumarate polymer: 19 wt%): 94 wt%, tetrabutyl pyromellitate: 6 wt%]. The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. to 1.5 times in length and 1.1 times in width (thickness after stretching: 143 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 12
130 g of cellulose butyrate (butyryl group = 82 mol%, total substitution degree DS = 2.46, number average molecular weight = 70,000), 30 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and 2- 7 g of (2′-hydroxy-5′-t-butylphenyl) benzotriazole (Δn = 0.13) was dissolved in 800 g of methylene chloride. The dissolved material is cast on a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 180 μm. [Resin component (cellulose butyrate: 81 wt%, diisopropyl fumarate / diethyl fumarate polymer: 19 wt%): 96 wt%, 2- (2′-hydroxy-5′-t-butylphenyl] ) Benzotriazole: 4% by weight]. The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. by 1.5 times in length and 1.1 times in width (thickness after stretching: 141 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 13
130 g of cellulose butyrate (butyryl group = 82 mol%, total substitution DS = 2.46, number average molecular weight = 70,000), 30 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and 2, 7 g of 4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3,5-triazine (Δn = 0.21) was dissolved in 800 g of methylene chloride. The dissolved material is cast on a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 180 μm. [Resin component (cellulose butyrate: 81% by weight, diisopropyl fumarate / diethyl fumarate polymer: 19% by weight): 96% by weight, 2,4-diphenyl-6- (2-hydroxy-4- Methoxyphenyl) -1,3,5-triazine: 4% by weight]. The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. to 1.5 times in length and 1.1 times in width (140 μm thickness after stretching).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 14
130 g of cellulose butyrate (butyryl group = 82 mol%, total substitution degree DS = 2.46, number average molecular weight = 70,000), 30 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and benzoic acid 20 g of ethyl (Δn = 0.08) was dissolved in 800 g of methylene chloride. The dissolved material is cast on a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 180 μm. [Resin component (cellulose butyrate: 81 wt%, diisopropyl fumarate / diethyl fumarate polymer: 19 wt%): 89 wt%, ethyl benzoate: 11 wt%]. The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. to 1.5 times in length and 1.1 times in width (thickness after stretching: 148 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 15
130 g cellulose butyrate (butyryl group = 82 mol%, total substitution degree DS = 2.46, number average molecular weight = 70,000), 30 g diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and diethyl phthalate 20 g (Δn = 0.07) was dissolved in 800 g of methylene chloride. The dissolved material is cast on a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 180 μm. [Resin component (cellulose butyrate: 81 wt%, diisopropyl fumarate / diethyl fumarate polymer: 19 wt%): 89 wt%, diethyl phthalate: 11 wt%]. The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. to 1.5 times in length and 1.1 times in width (thickness after stretching: 149 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Example 16
130 g of cellulose butyrate (butyryl group = 82 mol%, total substitution degree DS = 2.46, number average molecular weight = 70,000), 30 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and triclet Zilphosphate 53 g was dissolved in 640 g of methylene chloride. The dissolved material is cast onto a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 150 μm. [Resin component (cellulose butyrate: 81 wt%, diisopropyl fumarate / diethyl fumarate polymer: 19 wt%): 75 wt%, tricresyl phosphate: 25 wt%]. The obtained optical compensation film was cut into a 50 mm square and stretched at 120 ° C. to 1.5 times in length and 1.1 times in width (thickness after stretching 121 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are shown in Table 1.

  The obtained optical compensation film had high optical transmittance, excellent transparency, small haze, in-plane retardation (Re) and Nz coefficient, and the desired optical characteristics.

Comparative Example 1
200 g of cellulose butyrate and 10 g of tricresyl phosphate (Δn = 0.18) used in Example 1 were dissolved in 800 g of methylene chloride, cast on a support of a solution casting apparatus by a T-die method, and a drying temperature of 30 The film (resin composition) having a width of 150 mm and a thickness of 80 μm was obtained (cellulose butyrate: 95 wt%, tricresyl phosphate: 5 wt%).

  The total light transmittance, haze, and retardation characteristics of the obtained film were measured. The results are shown in Table 2.

得られたフィルムは全光線透過率が高く透明性に優れる、ヘーズが小さいものの、厚み方向の位相差（Ｒｔｈ）が大きく目的とする光学特性を有していなかった。

The obtained film had a high total light transmittance and excellent transparency and a small haze, but had a large retardation in the thickness direction (Rth) and did not have the desired optical properties.

Comparative Example 2
200 g of cellulose acetate butyrate and 10 g of tricresyl phosphate (Δn = 0.18) used in Example 2 were dissolved in 800 g of tetrahydrofuran, and cast on a support of a solution casting apparatus by a T-die method. The film (resin composition) having a width of 150 mm and a thickness of 77 μm was obtained (cellulose acetate butyrate: 95% by weight, tricresyl phosphate: 5% by weight).

  The total light transmittance, haze, and retardation characteristics of the obtained film were measured. The results are also shown in Table 2.

  Although the obtained film had high total light transmittance and excellent transparency and small haze, the out-of-plane retardation (Rth) in the thickness direction was large and did not have the desired optical characteristics.

Comparative Example 3
200 g of diisopropyl fumarate / diethyl fumarate polymer used in Example 1 and 10 g of tricresyl phosphate (Δn = 0.18) were dissolved in 800 g of methylene chloride, and the resulting solution was poured onto the support of the solution casting apparatus by the T-die method. And dried stepwise at a drying temperature of 30 ° C. and then 80 ° C. to obtain a film (resin composition) having a width of 150 mm and a thickness of 80 μm (resin component: 95 wt%, tricresyl phosphate: 5 wt%) .

  The total light transmittance, haze, and retardation characteristics of the obtained film were measured. The results are also shown in Table 2.

  Although the obtained film had high total light transmittance and excellent transparency and small haze, the out-of-plane retardation (Rth) in the thickness direction was large and did not have the desired optical characteristics.

Comparative Example 4
200 g of cellulose acetate butyrate and 10 g of tricresyl phosphate (Δn = 0.18) used in Example 2 were dissolved in 800 g of methyl ethyl ketone, and cast on a support of a solution casting apparatus by a T-die method. After drying stepwise at 100 ° C. and then at 100 ° C., an optical compensation film (resin composition) having a width of 150 mm and a thickness of 200 μm was obtained (cellulose acetate butyrate: 95 wt%, tricresyl phosphate: 5 wt%). The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. to 1.5 times in length and 1.1 times in width (thickness after stretching: 163 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 2.

  The obtained optical compensation film had a high total light transmittance and excellent transparency, but had a small haze, but the in-plane retardation (Re) and Nz coefficient did not have the desired optical characteristics.

Comparative Example 5
136 g of cellulose butyrate (butyryl group = 87 mol%, total substitution degree DS = 2.61, number average molecular weight = 70,000), diisopropyl fumarate / di-n-butyl fumarate obtained in Synthesis Example 2 34 g and 10 g of diisodecyl adipate (Δn = 0.02) were dissolved in 800 g of methyl ethyl ketone. The dissolved material is cast on a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 220 μm. [Resin component (cellulose butyrate: 80 wt%, diisopropyl fumarate / di-n-butyl fumarate polymer: 20 wt%): 94 wt%, diisodecyl adipate: 6 wt%]. The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. to 1.5 times in length and 1.1 times in width.

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 2.

  The obtained optical compensation film had a high total light transmittance and excellent transparency, but had a small haze, but the in-plane retardation (Re) and Nz coefficient did not have the desired optical characteristics.

Comparative Example 6
11 g of cellulose butyrate (butyryl group = 82 mol%, total substitution degree DS = 2.46, number average molecular weight = 70,000), 159 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and triclet 10 g of zilphate (Δn = 0.18) was dissolved in 800 g of methylene chloride. The dissolved material is cast on a support of a solution casting apparatus by a T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then an optical compensation film (resin composition) having a width of 150 mm and a thickness of 200 μm. [Resin component (cellulose butyrate: 6% by weight, diisopropyl fumarate / diethyl fumarate polymer: 94% by weight): 94% by weight, tricresyl phosphate: 6% by weight]. The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. to 1.5 times in length and 1.1 times in width (thickness after stretching: 164 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 2.

  The obtained optical compensation film had a high total light transmittance and excellent transparency, but had a small haze, but the Nz coefficient did not have the desired optical characteristics.

Comparative Example 7
145 g of cellulose butyrate (butyryl group = 82 mol%, total substitution DS = 2.46, number average molecular weight = 70,000), 25 g of diisopropyl fumarate / diethyl fumarate polymer obtained in Synthesis Example 1 and triclet 91 g of zirconium phosphate (Δn = 0.18) was dissolved in 800 g of methylene chloride. The melted material is cast on a support of a solution casting apparatus by the T-die method, dried stepwise at a drying temperature of 30 ° C. and then 100 ° C., and then a resin composition (optical compensation film) having a width of 150 mm and a thickness of 200 μm. (Resin component (cellulose butyrate: 85% by weight, diisopropyl fumarate / diethyl fumarate polymer: 15% by weight): 65% by weight, tricresyl phosphate: 35% by weight). The obtained optical compensation film was cut into a 50 mm square and stretched at 125 ° C. to 1.5 times in length and 1.1 times in width (thickness after stretching: 162 μm).

  The total optical transmittance, haze, and retardation characteristics of the obtained optical compensation film were measured. The results are also shown in Table 2.

  The obtained optical compensation film had a high total light transmittance and excellent transparency, but had a small haze, but the in-plane retardation (Re) and Nz coefficient did not have the desired optical characteristics.

Claims (15)

A fumaric acid diester polymer 90 to 1 containing 10 to 99% by weight of a cellulose resin represented by the following general formula (1) and 60 mol% or more of a fumaric acid diester residue unit represented by the following general formula (2) as a resin component. A resin comprising 70% to 99.99% by weight of the resin component and 0.01 to 30% by weight of an additive having an aromatic hydrocarbon ring or an aromatic heterocyclic ring. Composition.

_{(Wherein, R 1, R 2, R} 3 each independently represent hydrogen or an acyl group having 1 to 12 carbon atoms.)

(In formula, R < ₄ >, R < ₅ > shows a C1-C12 alkyl group each independently.) 2. The resin composition according to claim 1, wherein the acylation degree of the cellulose resin represented by the general formula (1) is 1.5 to 3.0. The fumaric acid diester polymer comprises 60-95 mol% diisopropyl fumarate residue units and diethyl fumarate residue units, di-n-propyl fumarate residue units, di-n-butyl fumarate residue units, fumaric acid 3. The resin composition according to claim 1, comprising 5 to 40 mol% of a fumaric acid diester residue unit selected from di-2-ethylhexyl residue units. The additive having an aromatic hydrocarbon ring or an aromatic heterocycle has a birefringence Δn represented by the following formula (1) of 0.05 or more, and is any one of claims 1 to 3 The resin composition as described in the term.
Δn = ny−nx (1)
(In the formula, nx represents the refractive index in the fast axis direction of the additive molecule, and ny represents the refractive index in the slow axis direction of the additive molecule.) The additive having an aromatic hydrocarbon ring or aromatic heterocycle has 1 to 12 aromatic hydrocarbon rings or aromatic heterocycles in the molecule. Item 5. The resin composition according to any one of Items 4. An optical compensation film comprising the resin composition according to any one of claims 1 to 5 and having a thickness of 5 to 200 µm. The in-plane retardation (Re) represented by the following formula (2) is 80 to 300 nm, and the Nz coefficient represented by the following formula (3) is 0.35 to 0.65. The optical compensation film described.
Re = (ny−nx) × d (2)
Nz = (ny−nz) / (ny−nx) (3)
(Where nx represents the refractive index in the fast axis direction in the film plane, ny represents the refractive index in the slow axis direction in the film plane, nz represents the refractive index outside the film plane, and d represents the film. Indicates thickness.) The in-plane retardation (Re) represented by the formula (2) is 50 to 200 nm, and the Nz coefficient represented by the formula (3) is -0.2 to 0.2. Optical compensation film. The in-plane retardation (Re) represented by the formula (2) is 0 to 20 nm, and the out-of-plane retardation (Rth) represented by the following formula (4) is -150 to 10 nm. 6. The optical compensation film according to 6.
Rth = [(nx + ny) / 2−nz] × d (4)
(Where nx represents the refractive index in the fast axis direction in the film plane, ny represents the refractive index in the slow axis direction in the film plane, nz represents the refractive index outside the film plane, and d represents the film. Indicates thickness.) The optical compensation film according to any one of claims 6 to 9, wherein the light transmittance is 85% or more. The optical compensation film according to any one of claims 6 to 10, wherein the haze is 2% or less. A fumaric acid diester polymer 90 to 1 containing 10 to 99% by weight of a cellulose resin represented by the following general formula (1) and 60 mol% or more of a fumaric acid diester residue unit represented by the following general formula (2) as a resin component. Resin obtained by dissolving 70 to 99.99% by weight of the resin component and 0.01 to 30% by weight of an additive having an aromatic hydrocarbon ring or aromatic hetero ring in a solvent. The method for producing an optical compensation film according to any one of claims 6 to 11, wherein the solution is cast onto a base material, and after drying, the solution is peeled off from the base material.

_{(Wherein, R 1, R 2, R} 3 each independently represent hydrogen or an acyl group having 1 to 12 carbon atoms.)

(In formula, R < ₄ >, R < ₅ > shows a C1-C12 alkyl group each independently.) The method for producing an optical compensation film according to claim 12, wherein the cellulose resin represented by the general formula (1) has an acylation degree of 1.5 to 3.0. The fumaric acid diester polymer comprises 60-95 mol% diisopropyl fumarate residue units and diethyl fumarate residue units, di-n-propyl fumarate residue units, di-n-butyl fumarate residue units, fumaric acid 14. The method for producing an optical compensation film according to claim 12, comprising 5 to 40 mol% of a fumaric acid diester residue unit selected from di-2-ethylhexyl residue units. 9. The method for producing an optical compensation film according to claim 7, wherein a film having a thickness of 40 to 200 [mu] m obtained by casting is uniaxially stretched or unbalanced biaxially stretched.