JP2017165794A - Resin composition and optical compensation film prepared therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition having excellent phase difference properties and an optical compensation film prepared therewith.SOLUTION: The present invention provides a resin composition comprising a cellulose resin 30-85 wt.%, a fumarate-cinnamate copolymer resin 5-65 wt.%, and a phosphorous compound represented by formula (1) and/or formula (2) 1-20 wt.%.SELECTED DRAWING: None

Description

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

  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 retardation values suitable for 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 produce an optical compensation film having a refractive index of nx ≧ ny> nz and other three-dimensional refractive indexes, for example, a three-dimensional refractive index such as nx> nz> ny or nx = nz> ny. Requires a special stretching method such as bonding a heat-shrinkable film to one or both sides of the film, heat-stretching the laminate, and applying a shrinkage force in the thickness direction of the polymer film, and a refractive index ( It is also difficult to control the phase difference value (see, for example, Patent Documents 1 to 3).

  Here, nx represents the refractive index in the direction of the stretching axis in the film plane, ny represents the refractive index in the direction perpendicular to the stretching axis in the film plane, and nz represents the refractive index outside the film plane (thickness direction). .

  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 slow axis direction in the film plane, ny is the refractive index in the direction perpendicular to the stretching axis in the film plane, nz is the refractive index outside the film plane (thickness direction), d Indicates film thickness.)
Moreover, the retardation film which consists of a fumarate-type resin is proposed (for example, refer patent document 4).

  However, the stretched film made of a fumarate ester resin has a three-dimensional refractive index of nz> ny> nx, and an optical compensation film having a three-dimensional refractive index such as nx> nz> ny or nx = nz> ny. In order to obtain it, lamination with another optical compensation film or the like is necessary.

  Then, as an optical compensation film which shows the said three-dimensional refractive index, the resin composition and the optical compensation film using the same are proposed (for example, refer patent document 5-patent document 7).

  Although Patent Documents 5 to 7 show the above-mentioned three-dimensional refractive index, there is a demand for an optical compensation film that exhibits the above-mentioned three-dimensional refractive index and has a large retardation and a thinner film.

Japanese Patent No. 2818983 JP-A-5-297223 JP-A-5-323120 JP 2008-64817 A JP 2013-28741 A JP 2014-125609 A JP 2014-125610 A

  This invention is made | formed in view of the said subject, The objective is to provide the resin composition excellent in retardation characteristics, and an optical compensation film using the same.

  As a result of intensive studies to solve the above problems, the present inventors have found that an optical compensation film using a specific resin composition can solve the above problems, and have completed the present invention.

  That is, the present invention relates to a cellulose resin of 30 to 85% by weight, a fumaric acid ester-cinnamic acid ester copolymer resin containing 5 to 65% by weight of a fumaric acid ester residue unit and a cinnamic acid ester residue unit, and A resin composition containing 1 to 20% by weight of a phosphorus compound represented by the general formula (1) and / or a phosphorus compound represented by the following general formula (2), and an optical compensation film using the resin composition.

(Wherein R ₁ , R ₂ and R ₃ each independently represent hydrogen, an alkyl group, a phenyl group or a cumyl group.)

(In the formula, R ₄ , R ₅ and R ₆ each independently represents hydrogen or an alkyl group.)
Hereinafter, the present invention will be described in detail.

  The resin composition of the present invention comprises a cellulose resin 30 to 85% by weight, a fumaric acid ester-cinnamic acid ester copolymer resin 5 to 65% by weight containing a fumaric acid ester residue unit and a cinnamic acid ester residue unit, And 1 to 20% by weight of a phosphorus compound represented by the following general formula (1) and / or a phosphorus compound represented by the following general formula (2).

(Wherein R ₁ , R ₂ and R ₃ each independently represent hydrogen, an alkyl group, a phenyl group or a cumyl group.)

(In the formula, R ₄ , R ₅ and R ₆ each independently represents hydrogen or an alkyl group.)
The resin composition of the present invention contains a cellulose resin and a fumaric acid ester-cinnamic acid ester copolymer resin containing a fumaric acid ester residue unit and a cinnamic acid ester residue unit, thereby being used as an optical compensation film. In this case, the optical compensation film exhibits a three-dimensional refractive index such as nx>nz> ny and nx = nz> ny.

  In the present invention, the cellulose-based resin is not particularly limited, but when used as an optical compensation film, it is excellent in compatibility with a fumarate-cinnamate copolymer resin and has a large in-plane retardation Re. Since it becomes what is excellent in extending | stretching workability, it is preferable that it is a cellulose resin shown by following General formula (3).

(In formula, R < ₇ >, R <_8> , R < ₉ > shows hydrogen or a C1-C10 substituent each independently.)
Here, the cellulose resin represented by the general formula (3) is a polymer in which β-glucose units are linearly polymerized, and part or all of hydroxyl groups at the 2nd, 3rd and 6th positions of the glucose unit. Is a polymer substituted.

  The cellulose resin represented by the general formula (3) has hydrogen or a substituent having 1 to 10 carbon atoms from the viewpoint of solubility and compatibility. Examples of the substituent having 1 to 10 carbon atoms include acetyl group, propionyl group, butyryl group, pentanoyl group, hexanoyl group, heptanoyl group, octanoyl group, decanoyl group, isobutyryl group, t-butyryl group, cyclohexanoyl group, Benzoyl, naphthoyl, methoxy, ethoxy, propoxy, butoxy, hexyloxy, octyloxy, decanoxy, isobutoxy, t-butoxy, cyclohexoxy, phenoxy, benzyloxy, naphthoxy, hydroxymethyl Group, hydroxyethyl group, hydroxypropyl group, hydroxybutyl group, cyanoethyl group, carboxymethyl group, carboxyethyl group, aminoethyl group and the like. Among these, an acetyl group, a propionyl group, a butyryl group, a methoxy group, and an ethoxy group are preferable because the solubility and compatibility are further improved.

  The cellulose-based resin of the present invention may have only one type of substituent, or may have two or more types of substituents.

  The substitution degree of substitution through the oxygen atom of the hydroxyl group of cellulose in the cellulose resin of the present invention is the ratio of substitution of the hydroxyl group of cellulose for each of the 2-position, 3-position and 6-position (100% substitution) Means the degree of substitution 3), and the degree of substitution is preferably 1.5 to 3.0, more preferably 1.8 to 2.8 from the viewpoint of solubility, compatibility and stretch processability. .

  Specific examples of the cellulose resin of the present invention include methyl cellulose, ethyl cellulose, triacetyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, and the like. Since a compensation film is obtained, ethyl cellulose, cellulose acetate butyrate, and cellulose acetate propionate are preferable.

Since the cellulose resin of the present invention has excellent mechanical properties and excellent moldability during film formation, standard polystyrene obtained from an elution curve measured by gel permeation chromatography (GPC). The converted number average molecular weight (Mn) is preferably 1 × 10 ³ to 1 × 10 ⁶ , more preferably 5 × 10 ³ to 2 × 10 ⁵ .

  The fumaric acid ester-cinnamate copolymer resin of the present invention includes a fumaric acid ester residue unit and a cinnamic acid ester residue unit. In the present invention, when the fumaric acid ester-cinnamic acid ester copolymer resin does not contain a fumaric acid ester residue unit, the compatibility with the cellulosic resin is inferior and does not contain a cinnamic acid ester residue unit. The phase difference characteristics are inferior.

  The fumaric acid ester-cinnamic acid ester copolymer resin of the present invention is not particularly limited as long as it contains a fumaric acid ester residue unit and a cinnamic acid ester residue unit, but is excellent in retardation characteristics and transparency. Since an optical compensation film is obtained, 1 to 65 mol% of a fumaric acid diester residue unit represented by the following general formula (4), 1 to 30 mol% of a fumaric acid monoester residue unit represented by the following general formula (5) And it is preferable that the cinnamate ester unit represented by the following general formula (6) contains 98 to 5 mol%.

(In formula, R < ₁₀ >, R < ₁₁ > shows a C1-C12 alkyl group each independently.)

(In the formula, R ₁₂ represents an alkyl group having 1 to 12 carbon atoms.)

(In formula, R < ₁₃ >, R < ₁₄ > shows a C1-C12 alkyl group each independently.)
R ₁₀ and R ₁₁ of the fumaric acid diester residue unit in the general formula (4) are each independently an alkyl group having 1 to 12 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, n- Examples include butyl 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. It is done.

  Specific examples of the fumaric acid diester residue unit represented by the general formula (4) include dimethyl fumarate residue, diethyl fumarate residue, di-n-propyl fumarate residue, diisopropyl fumarate residue, Di-n-butyl fumarate residue, di-s-butyl fumarate residue, di-t-butyl fumarate residue, di-n-pentyl fumarate residue, di-s-pentyl fumarate residue, Di-t-pentyl fumarate residue, di-n-hexyl fumarate residue, di-s-hexyl fumarate residue, di-t-hexyl fumarate residue, di-2-ethylhexyl fumarate, fumaric acid Examples include dicyclopropyl residue, dicyclopentyl fumarate residue, dicyclohexyl fumarate residue and the like. Of these, diethyl fumarate residue, diisopropyl fumarate residue, and di-t-butyl fumarate residue are preferable because of excellent compatibility and retardation characteristics.

R ₁₂ of the fumaric acid monoester residue unit in the general formula (5) is an alkyl group having 1 to 12 carbon atoms, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl 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.

  Specific examples of the fumaric acid monoester residue unit represented by the general formula (5) include a monomethyl fumarate residue, a monoethyl fumarate residue, a mono-n-propyl fumarate residue, and a monoisopropyl fumarate residue. Group, mono-n-butyl fumarate residue, mono-s-butyl fumarate residue, mono-t-butyl fumarate residue, mono-n-pentyl fumarate residue, mono-s-pentyl fumarate residue Group, mono-t-pentyl fumarate residue, mono-n-hexyl fumarate residue, mono-s-hexyl fumarate residue, mono-t-hexyl fumarate residue, mono-2-ethylhexyl fumarate, Examples thereof include a monocyclopropyl fumarate residue, a monocyclopentyl fumarate residue, a monocyclohexyl fumarate residue and the like. Among these, since it is excellent in compatibility and retardation characteristics, monoethyl fumarate residue, monoisopropyl fumarate residue, mono-n-propyl fumarate residue, mono-n-butyl fumarate residue, fumaric acid Mono-2-ethylhexyl residues are preferred.

R ₁₃ and R _{14 in} the cinnamic acid ester residue unit in the general formula (6) are alkyl groups having 1 to 12 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, Examples thereof include 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.

  Specific examples of the cinnamate residue represented by the general formula (6) include 4-methoxycinnamate methyl residue, 4-methoxycinnamate ethyl residue, and 4-methoxycinnamate isopropyl residue. A group, 4-methoxycinnamic acid n-propyl residue, 4-methoxycinnamic acid n-butyl residue, 4-methoxycinnamic acid sec-butyl residue, 4-methoxycinnamic acid tert-butyl residue, 4-methoxy cinnamate 2-ethylhexyl residue, 4-ethoxy cinnamate methyl residue, 4-ethoxy cinnamate ethyl residue, 4-ethoxy cinnamate isopropyl residue, 4-ethoxy cinnamate n-propyl residue, 4-ethoxycinnamic acid n-butyl residue, 4-ethoxycinnamic acid sec-butyl residue, 4-ethoxycinnamic acid tert-butyl residue, 4-ethoxycinnamic acid 2-ethylhexyl residue, 4-isopropoxy Methyl cinnamate residue, 4-isopropoxycinnamic acid ethyl residue, 4-isopropoxycinnamic acid isopropyl residue, 4-isopropoxycinnamic acid n-propyl residue, 4-isopropoxycinnamic acid n -Butyl residue, 4-isopropoxycinnamic acid sec-butyl residue, 4-isopropoxycinnamic acid tert-butyl residue, 4-isopropoxycinnamic acid 2-ethylhexyl residue, 4-n-propoxycin Methyl cinnamate residue, 4-n-propoxycinnamate ethyl residue, 4-n-propoxycinnamate isopropyl residue, 4-n-propoxycinnamate n-propyl residue, 4-n-propoxycin Cinnamate n-butyl residue, 4-n-propoxycinnamate sec-butyl residue, 4-n-propoxycinnamate tert-butyl residue, 4-n-propoxycinnamate 2-ethylhexyl residue, 4- -Methyl butoxycinnamic acid residue, 4-n-butoxycinnamic acid ethyl residue, 4-n-butoxycinnamic acid isopropyl residue, 4-n-butoxycinnamic acid n-propyl residue, 4-n-butoxycinnamic acid residue n-butyl residue, 4-n-butoxycinnamic acid sec-butyl residue, 4-n-butoxycinnamic acid tert-butyl residue, 4-n-butoxycinnamic acid 2-ethylhexyl residue, 4-sec-butoxysilicate Methyl cinnamate residue, 4-sec-butoxycinnamate ethyl residue, 4-sec-butoxycinnamate isopropyl residue, 4-sec-butoxycinnamate n-propyl residue, 4-sec-butoxycinnamate n- Butyl residue, 4-sec-butoxycinnamic acid sec-butyl residue, 4-sec-butoxycinnamic acid tert-butyl residue, 4-sec-butoxycinnamic acid 2-ethylhexyl Residue, 4-tert-butoxycinnamic acid methyl residue, 4-tert-butoxycinnamic acid ethyl residue, 4-tert-butoxycinnamic acid isopropyl residue, 4-tert-butoxycinnamic acid n-propyl residue, 4-tert-Butoxycinnamic acid n-butyl residue, 4-tert-Butoxycinnamic acid sec-Butyl residue, 4-tert-Butoxycinnamic acid tert-Butyl residue, 4-tert-Butoxycinnamic acid 2-ethylhexyl residue 3-methyl cinnamate residues, 3-methoxy ethyl cinnamate residues, 3-methoxy cinnamate ethyl residues, 3-methoxy cinnamate isopropyl residues, 3-methoxy cinnamate n-propyl residues, 3-methoxy cinnamate n-butyl residue, 3-methoxycinnamic acid sec-butyl residue, 3-methoxycinnamic acid tert-butyl residue, 3-methoxycinnamic acid 2-ethylhexyl residue 3-methyl ethoxycinnamate residue, 3-ethoxyethyl cinnamate residue, 3-ethoxy cinnamate isopropyl residue, 3-ethoxycinnamic acid n-propyl residue, 3-ethoxycinnamic acid n-butyl residue 3-Ethoxycinnamic acid sec-Butyl residue, 3-Ethoxycinnamic acid tert-Butyl residue, 3-Ethoxycinnamic acid 2-ethylhexyl residue, 3-Isopropoxycinnamic acid methyl residue, 3-Isopropoxysilicate Ethyl cinnamate residue, 3-isopropoxycinnamate isopropyl residue, 3-isopropoxycinnamate n-propyl residue, 3-isopropoxycinnamate n-butyl residue, 3-isopropoxycinnamate sec-butyl residue, 3-isopropoxycinnamate tert-butyl residue, 3-isopropoxycinnamate 2-ethylhexyl residue, 3-n-propoxycinnamate methyl Groups, 3-n-propoxycinnamic acid ethyl residue, 3-n-propoxycinnamic acid isopropyl residue, 3-n-propoxycinnamic acid n-propyl residue, 3-n-propoxycinnamic acid n- Butyl residue, 3-n-propoxycinnamic acid sec-butyl residue, 3-n-propoxycinnamic acid tert-butyl residue, 3-n-propoxycinnamic acid 2-ethylhexyl residue, 3-n- Butoxycinnamate methyl residue, 3-n-butoxycinnamate ethyl residue, 3-n-butoxycinnamate isopropyl residue, 3-n-butoxycinnamate n-propyl residue, 3-n-butoxycinnamate n -Butyl residue, 3-n-butoxycinnamate sec-butyl residue, 3-n-butoxycinnamate tert-butyl residue, 3-n-butoxycinnamate 2-ethylhexyl residue, 3-sec-butoxycinnamate Methyl acid residue 3-sec-butoxycinnamate ethyl residue, 3-sec-butoxycinnamate isopropyl residue, 3-sec-butoxycinnamate n-propyl residue, 3-sec-butoxycinnamate n-butyl residue, 3 -sec-butoxycinnamate sec-butyl residue, 3-sec-butoxycinnamate tert-butyl residue, 3-sec-butoxycinnamate 3-ethylhexyl residue, 3-tert-butoxycinnamate methyl residue, 3 -tert-butoxycinnamate ethyl residue, 3-tert-butoxycinnamate isopropyl residue, 3-tert-butoxycinnamate n-propyl residue, 3-tert-butoxycinnamate n-butyl residue, 3-tert -Butoxycinnamic acid sec-butyl residue, 3-tert-butoxycinnamic acid tert-butyl residue, 3-tert-butoxycinnamic acid 2-ethylhexyl residue, 2-methoxymethylcinnamate residue, 2-methoxyethylcinnamate residue, 2-methoxyisopropylcinnamate residue, 2-methoxycinnamate n-propyl residue, 2- Methoxycinnamic acid n-butyl residue, 2-methoxycinnamic acid sec-butyl residue, 2-methoxycinnamic acid tert-butyl residue, 2-methoxycinnamic acid 2-ethylhexyl residue, 2-ethoxycinnamic leather Acid methyl residue, 2-ethoxycinnamic acid ethyl residue, 2-ethoxycinnamic acid isopropyl residue, 2-ethoxycinnamic acid n-propyl residue, 2-ethoxycinnamic acid n-butyl residue, 2-ethoxycinnamic acid sec-butyl residue, 2-ethoxycinnamic acid tert-butyl residue, 2-ethoxycinnamic acid 2-ethylhexyl residue, 2-isopropoxycinnamic acid methyl residue, 2-isopropoxycinnamic leather Ethyl residue, 2-isopropoxycinnamic acid isopropyl residue, 2-isopropoxycinnamic acid n-propyl residue, 2-isopropoxycinnamic acid n-butyl residue, 2-isopropoxycinnamic acid sec- Butyl residue, 2-isopropoxycinnamic acid tert-butyl residue, 2-isopropoxycinnamic acid 2-ethylhexyl residue, 2-n-propoxycinnamic acid methyl residue, 2-n-propoxycinnamic acid Ethyl residue, 2-n-propoxycinnamate isopropyl residue, 2-n-propoxycinnamate n-propyl residue, 2-n-propoxycinnamate n-butyl residue, 2-n-propoxycin Cinnamic acid sec-butyl residue, 2-n-propoxycinnamic acid tert-butyl residue, 2-n-propoxycinnamic acid 2-ethylhexyl residue, 2-n-butoxycinnamic acid methyl residue, 2-n -Butoki Ethyl cinnamate residue, 2-n-butoxy cinnamate isopropyl residue, 2-n-butoxy cinnamate n-propyl residue, 2-n-butoxy cinnamate n-butyl residue, 2-n-butoxy cinnamate residue Acid sec-butyl residue, 2-n-butoxycinnamate tert-butyl residue, 2-n-butoxycinnamate 2-ethylhexyl residue, 2-sec-butoxycinnamate methyl residue, 2-sec-butoxycinnamate Ethyl acid residue, 2-sec-butoxycinnamic acid isopropyl residue, 2-sec-butoxycinnamic acid n-propyl residue, 2-sec-butoxycinnamic acid n-butyl residue, 2-sec-butoxycinnamic acid sec -Butyl residue, 2-sec-butoxycinnamate tert-butyl residue, 2-sec-butoxycinnamate 2-ethylhexyl residue, 2-tert-butoxycinnamate methyl A group, 2-tert-butoxycinnamate ethyl residue, 2-tert-butoxycinnamate isopropyl residue, 2-tert-butoxycinnamate n-propyl residue, 2-tert-butoxycinnamate n-butyl residue, Examples include 2-tert-butoxycinnamic acid sec-butyl residue, 2-tert-butoxycinnamic acid tert-butyl residue, 2-tert-butoxycinnamic acid 2-ethylhexyl residue, and the like. Among these, since it is excellent in compatibility and retardation properties, 4-methoxycinnamate methyl residue, 4-methoxycinnamate ethyl residue, 4-methoxycinnamate n-propyl residue, 4-methoxy A 2-ethylhexyl cinnamate residue is preferred.

Since the fumaric acid ester-cinnamic acid ester copolymer resin of the present invention is particularly excellent in mechanical properties and excellent in moldability during film formation, it is obtained by gel permeation chromatography (GPC). The number average molecular weight (Mn) in terms of standard polystyrene obtained from the measured elution curve is preferably 1 × 10 ^{3 to} 5 × 10 ⁶ , and more preferably 5 × 10 ³ to 2 × 10 ⁵ .

  The resin composition of the present invention is excellent in retardation characteristics by containing a phosphorus compound represented by the following general formula (1) and / or a phosphorus compound represented by the following general formula (2). .

(Wherein R ₁ , R ₂ and R ₃ each independently represent hydrogen, an alkyl group, a phenyl group or a cumyl group.)

(In the formula, R ₄ , R ₅ and R ₆ each independently represents hydrogen or an alkyl group.)
In the phosphorus compound represented by the general formula (1) of the present invention, R ₁ , R ₂ , and R ₃ each independently represent hydrogen, an alkyl group, a phenyl group, or a cumyl group. Examples of the alkyl group include, for example, methyl Group, ethyl group, propyl group, isopropyl group, n-butyl 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.

  Specific examples of the phosphorus compound represented by the general formula (1) include di (nonylphenyl) pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4,6-tri-t-butylphenyl) pentaerythritol diphosphite, bis (2,4-dic (Milphenyl) pentaerythritol diphosphite, tetra (tridecyl) isopropylidene diphenol diphosphite, tetra (tridecyl) -4,4′-n-butylidenebis (2-t-butyl-5-methylphenol) diphosphite, etc. It is done. Among these, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite and bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite are excellent in retardation characteristics. Phosphites are preferred.

In the phosphorus compound represented by the general formula (2) of the present invention, R ₄ , R ₅ , and R ₆ each independently represent hydrogen or an alkyl group, and examples of the alkyl group include a methyl group, an ethyl group, and a propyl group. Group, isopropyl group, n-butyl 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.

  Specific examples of the phosphorus compound represented by the general formula (2) include tetrakis (2,4-di-tert-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4-di). -Tert-butyl-5-methylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3'-biphenylenediphosphonite, tetrakis (2,4 -Di-tert-butylphenyl) -3,3'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,6-di) -Tert-butylphenyl) -4,3'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -3 3′-biphenylene diphosphonite, bis (2,4-di-tert-butylphenyl) -4-phenyl-phenylphosphonite, bis (2,4-di-tert-butylphenyl) -3-phenyl-phenylphospho Bis (2,6-di-n-butylphenyl) -3-phenyl-phenylphosphonite, bis (2,6-di-tert-butylphenyl) -4-phenyl-phenylphosphonite, bis (2, 6-di-tert-butylphenyl) -3-phenyl-phenylphosphonite and the like. Among these, tetrakis (2,4-di-tert-butylphenyl) -4,4 is excellent because of excellent retardation characteristics. '-Biphenylenediphosphonite, tetrakis (2,4-di-tert-butyl-5-methylphenyl) -4,4'-biphenyl Njihosuhonaito is preferable.

  In the present invention, the ratio of the composition of the cellulose resin, the fumaric acid ester-cinnamate copolymer resin and the phosphorus compound can control the phase difference performance and can exhibit a more excellent phase difference. Therefore, the cellulose-based resin is 30 to 85% by weight, the fumaric acid ester-cinnamate copolymer resin is 5 to 65% by weight, and the phosphorus compound is 1 to 20% by weight. 80% by weight, 10 to 60% by weight of a fumaric acid ester-cinnamate copolymer resin, and 1 to 15% by weight of a phosphorus compound, more preferably 40 to 80% by weight of a cellulose resin, fumaric acid ester The cinnamate copolymer resin is 20 to 60% by weight and the phosphorus compound is 1 to 10% by weight.

  The fumarate-cinnamate copolymer resin of the present invention may be produced by any method as long as the resin is obtained. For example, a monomer having a residue unit represented by general formula (4) or general formula (5), or a monomer having a residue unit represented by general formula (4) or general formula (5) in some cases , And a monomer copolymerizable therewith, and can be produced by radical polymerization. Examples of the copolymerizable monomer at this time include styrenes such as styrene and α-methylstyrene; acrylic acid; acrylic acid esters such as methyl acrylate, ethyl acrylate, and butyl acrylate; methacrylic acid; Methacrylic acid esters such as methyl methacrylate, ethyl methacrylate and butyl methacrylate; Vinyl esters such as vinyl acetate and vinyl propionate; Acrylonitrile; Methacrylonitrile; N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide N-substituted maleimides such as; olefins such as ethylene and propylene; vinyl pyrrolidone; one or more of vinyl pyridine and the like.

  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 optical compensation film of the present invention contains other polymers, surfactants, polymer electrolytes, conductive complexes, pigments, dyes, antistatic agents, antiblocking agents, lubricants and the like within the scope of the invention. May be.

  The thickness of the optical compensation film of the present invention is preferably from 5 to 200 μm, more preferably from 5 to 150 μm, particularly preferably from 5 to 120 μm, from the viewpoints of handleability of the film and suitability for thinning of the optical member. .

  Since the retardation characteristics of the optical compensation film of the present invention are more excellent as display characteristics of the display, the in-plane retardation (Re) represented by the following formula (a) is 50 to 300 nm, and the following formula ( It is preferable that the Nz coefficient indicated by b) is 0.35 <Nz <0.65. The phase difference characteristics at this time are measured using a fully automatic birefringence meter (manufactured by Oji Scientific Instruments Co., Ltd., trade name KOBRA-21ADH) under a measurement wavelength of 589 nm.

Re = (nx−ny) × d (a)
Nz = (nx-nz) / (nx-ny) (b)
(Where nx represents the refractive index in the direction of the stretching axis in the film plane, ny represents the refractive index in the direction perpendicular to the stretching axis in the film plane, and nz represents the refractive index outside the film plane (thickness direction). D indicates the film thickness.)
In the present invention, the in-plane retardation (Re) is preferably 60 to 300 nm, more preferably 70 to 280 nm, and the Nz coefficient is preferably 0.35 to 0.65, and more preferably 0.45 to 0.4. 55.

  These have retardation characteristics that are difficult to develop with a general optical compensation film.

  As the wavelength dispersion characteristic of the optical compensation film of the present invention, the ratio Re (450) / Re (550) of the retardation at 450 nm to the retardation at 550 nm is preferably 0.60 <Re (450) in order to suppress color misregistration. /Re(550)<1.10, more preferably 0.60 <Re (450) / Re (550) <1.05, and particularly preferably 0.61 <Re (450) / Re (550). ) <1.02.

  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 1% or less, more preferably 0.5% or less, for improving contrast.

  In order to reduce the required film thickness, the optical compensation film of the present invention has a ratio Re (589) (nm) / film thickness (μm) of 589 nm to a film thickness (μm) of 4.0 nm / μm or more. It is preferable that

  As a method for producing the optical compensation film of the present invention, any method can be used as long as the optical compensation film of the present invention can be produced. However, an optical compensation film excellent in optical characteristics, heat resistance, surface characteristics and the like can be obtained. Therefore, it is preferable to manufacture 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. In general, a method of continuously extruding is 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. Solvents used in the solution include, for example, chlorinated solvents such as methylene chloride and chloroform; aromatic solvents such as toluene and xylene; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone and cyclohexanone; ethyl acetate, acetic acid An ester solvent such as butyl; an alcohol solvent such as methanol, ethanol, or propanol; an ether solvent such as dioxane or tetrahydrofuran; dimethylformamide, N-methylpyrrolidone, or the like can be used. Each resin and additive can be dissolved in a solvent and then blended. The powder, pellets, etc. of each resin can be kneaded and then dissolved in the solvent.

  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. The viscosity of the resin solution when producing the optical compensation film of the present invention 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 the optical compensation film of the present invention include a cellulose resin, a fumarate-cinnamate copolymer resin containing a fumarate residue unit and a cinnamate residue unit, and a general formula ( The resin composition containing the phosphorus compound represented by 1) or the phosphorus compound represented by the general formula (2) is dissolved in a solvent, and the resulting resin solution is cast on a substrate, dried, and then from the substrate. Exfoliation.

  The optical compensation film of the present invention is preferably uniaxially stretched or unbalanced biaxially stretched 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 preferably from 10 to 200 μm, more preferably from 30 to 180 μm, particularly preferably from 30 to 150 μm, from the viewpoint of ease of stretching treatment and compatibility with thinning of the optical member. .

  The stretching temperature is not particularly limited, but is preferably 50 to 200 ° C., more preferably 100 to 180 ° C., because good retardation characteristics can be obtained. The stretching ratio of uniaxial stretching is preferably 1.05 to 3.5 times, and more preferably 1.1 to 3.0 times because good retardation characteristics can be obtained. Since the stretch ratio of unbalanced biaxial stretching can provide good retardation characteristics, 1.05 to 3.5 times are preferable in the length direction, 1.1 to 3.0 times are more preferable, and the width direction 1.0 to 1.2 times is preferable, and 1.0 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 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.

  Since the optical compensation film of the present invention exhibits specific retardation characteristics, it is useful as an optical compensation film for liquid crystal displays and an antireflection film.

  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 (manufactured by Tosoh Corporation, trade name: C0-8011 (equipped with column GMH _HR- H)), measurement was performed at 40 ° C. using tetrahydrofuran or dimethylformamide as a solvent, It calculated | required as a standard polystyrene conversion value.

<Measurement of light transmittance and haze of optical compensation film>
The light transmittance and haze of the produced film 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 version). The measurement was performed according to JIS-K 7136 (2000 version).

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

<Measurement of wavelength dispersion characteristics>
Using a sample tilt type automatic birefringence meter (manufactured by Oji Scientific Instruments, trade name: KOBRA-WR), optical as a ratio of phase difference Re (450) due to light having a wavelength of 450 nm and phase difference Re (550) due to light having a wavelength of 550 nm The wavelength dispersion characteristic of the compensation film was measured.

Synthesis Example 1 (Synthesis of diisopropyl fumarate / monoethyl fumarate / 4-methoxycinnamate n-propyl copolymer resin)
A glass ampule with a capacity of 75 mL was charged with 11 g of diisopropyl fumarate, 3 g of monoethyl fumarate, 42 g of n-propyl 4-methoxycinnamate, and 0.56 g of tert-butyl peroxypivalate as a polymerization initiator, and replaced with nitrogen and depressurized. After repeating the above, it was sealed under reduced pressure. This ampoule was placed in a thermostat at 50 ° C. and held for 72 hours for radical polymerization. After completion of the polymerization reaction, the polymer was taken out from the ampoule and dissolved in 200 g of tetrahydrofuran. This polymer solution was dropped into 4 L of hexane and precipitated, and then vacuum dried at 80 ° C. for 10 hours to obtain 23 g of diisopropyl fumarate / monoethyl fumarate / 4-methoxycinnamate n-propyl copolymer resin. Obtained. The obtained copolymer resin has a number average molecular weight of 33,000, diisopropyl fumarate residue unit of 21 mol%, monoethyl fumarate residue unit of 8 mol%, 4-methoxycinnamic acid n-propyl residue unit of 71 mol%. Met.

Synthesis Example 2 (Synthesis of diisopropyl fumarate / monoethyl fumarate / 4-methoxyethyl cinnamate copolymer resin)
A glass ampoule with a capacity of 75 mL was charged with 26 g of diisopropyl fumarate, 6 g of monoethyl fumarate, 24 g of ethyl 4-methoxycinnamate and 0.56 g of tert-butyl peroxypivalate, a polymerization initiator, and repeated nitrogen substitution and depressurization. After that, it was sealed under reduced pressure. This ampoule was placed in a thermostat at 50 ° C. and held for 72 hours for radical polymerization. After completion of the polymerization reaction, the polymer was taken out from the ampoule and dissolved in 200 g of tetrahydrofuran. This polymer solution was dropped into 4 L of hexane and precipitated, and then vacuum-dried at 80 ° C. for 10 hours to obtain 31 g of diisopropyl fumarate / monoethyl fumarate / 4-methoxyethyl cinnamate copolymer resin. . The obtained copolymer resin had a number average molecular weight of 41,000, diisopropyl fumarate residue units of 38 mol%, monoethyl fumarate residue units of 15 mol%, and ethyl 4-methoxycinnamate residue units of 47 mol%. It was.

Synthesis Example 3 (Synthesis of diethyl fumarate / monoethyl fumarate / 4-methoxycinnamate n-propyl copolymer resin)
Put 75 g of diethyl fumarate, 10 g of monoethyl fumarate, 31 g of 4-methoxycinnamic acid n-propyl and 0.56 g of tert-butyl peroxypivalate, a polymerization initiator, into a glass ampoule with a capacity of 75 mL. After repeating the above, it was sealed under reduced pressure. This ampoule was placed in a thermostat at 50 ° C. and held for 72 hours for radical polymerization. After completion of the polymerization reaction, the polymer was taken out from the ampoule and dissolved in 200 g of tetrahydrofuran. This polymer solution was dropped into 4 L of hexane and precipitated, and then vacuum dried at 80 ° C. for 10 hours to obtain 22 g of diethyl fumarate / monoethyl fumarate / 4-methoxycinnamic acid n-propyl copolymer resin. Obtained. The obtained copolymer resin has a number average molecular weight of 31,000, diethyl fumarate residue unit 62 mol%, monoethyl fumarate residue unit 9 mol%, 4-methoxycinnamic acid n-propyl residue unit 29 mol%. Met.

Synthesis Example 4 (Synthesis of diethyl fumarate / monoethyl fumarate / 4-methoxyethyl cinnamate copolymer resin)
Place 75 g of glass ampoule with 13 g of diethyl fumarate, 20 g of monoethyl fumarate, 17 g of ethyl 4-methoxycinnamate and 0.56 g of tert-butyl peroxypivalate, a polymerization initiator, and repeat nitrogen substitution and depressurization. After that, it was sealed under reduced pressure. This ampoule was placed in a thermostat at 50 ° C. and held for 72 hours for radical polymerization. After completion of the polymerization reaction, the polymer was taken out from the ampoule and dissolved in 200 g of tetrahydrofuran. This polymer solution was dropped into 4 L of hexane and precipitated, and then vacuum-dried at 80 ° C. for 10 hours to obtain 19 g of diethyl fumarate / monoethyl fumarate / 4-methoxyethyl cinnamate copolymer resin. . The number average molecular weight of the obtained copolymer resin was 35,000, diethyl fumarate residue unit 40 mol%, monoethyl fumarate residue unit 21 mol%, and 4-methoxycinnamate ethyl residue unit 39 mol%. It was.

Synthesis Example 5 (Synthesis of diisopropyl fumarate / mono n-butyl fumarate / 4-methoxycinnamate n-propyl copolymer resin)
A glass ampule with a capacity of 75 mL was charged with 13 g of diisopropyl fumarate, 20 g of mono-n-butyl fumarate, 17 g of 4-methoxycinnamic acid n-propyl and 0.56 g of tert-butyl peroxypivalate as a polymerization initiator, and substituted with nitrogen. After repeating the depressurization, it was sealed in a reduced pressure state. This ampoule was placed in a thermostat at 50 ° C. and held for 72 hours for radical polymerization. After completion of the polymerization reaction, the polymer was taken out from the ampoule and dissolved in 200 g of tetrahydrofuran. This polymer solution was dropped into 4 L of hexane and precipitated, and then vacuum-dried at 80 ° C. for 10 hours to thereby copolymerize diisopropyl fumarate / mono-n-butyl fumarate / 4-methoxycinnamic acid n-propyl. 25 g of resin was obtained. The obtained copolymer resin has a number average molecular weight of 42,000, a diisopropyl fumarate residue unit of 57 mol%, a mono n-butyl fumarate residue unit of 28 mol%, and a 4-methoxycinnamic acid n-propyl residue unit. It was 15 mol%.

Example 1
13.4 g of ethyl cellulose (number average molecular weight 86,000, total substitution degree 2.5), 10 g of diisopropyl fumarate / monoethyl fumarate / 4-methoxycinnamate n-propyl copolymer resin obtained by Synthesis Example 1 and bis 0.97 g of (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite is dissolved in butyl acetate to give an 18% by weight resin solution, which is then poured onto a polyethylene terephthalate film with a coater and dried. After drying at a temperature of 60 ° C., an optical compensation film (resin composition) having a width of 150 mm was obtained (ethyl cellulose: 55% by weight, diisopropyl fumarate / monoethyl fumarate / 4-methoxycinnamic acid n-propyl copolymer resin). : 41% by weight, bis (2,6-di-t-butyl-4-methylphenyl) pentaeri Li diphosphite: 4 wt%). The obtained optical compensation film was cut into a 50 mm square and uniaxially stretched 2.0 times at 140 ° C. (thickness after stretching: 40 μm). The optical compensation film thus obtained was measured for light transmittance, haze, retardation characteristics, and wavelength dispersion characteristics. 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.

Example 2
14.5 g of cellulose acetate butyrate (number average molecular weight 33,000, acetyl group = 15 mol%, butyryl group = 70 mol%, total substitution degree DS = 2.55), diisopropyl fumarate obtained in Synthesis Example 1 / 9 g of monoethyl fumarate / 4-methoxycinnamate n-propyl copolymer resin and 1.5 g of bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite were dissolved in butyl acetate. An 18% by weight resin solution was poured on a polyethylene terephthalate film with a coater and dried at a drying temperature of 60 ° C. to obtain an optical compensation film (resin composition) having a width of 150 mm (cellulose acetate butyrate: 58% by weight). %, Diisopropyl fumarate / monoethyl fumarate / 4-methoxycinnamate n-propyl copolymer Resin: 36 wt%, bis (2,6-di -t- butyl-4-methylphenyl) pentaerythritol diphosphite: 6 wt%). The obtained optical compensation film was cut into a 50 mm square and uniaxially stretched 2.0 times at 140 ° C. (thickness after stretching: 40 μm). The optical compensation film thus obtained was measured for light transmittance, haze, retardation characteristics, and wavelength dispersion characteristics. 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
17 g of ethyl cellulose (number average molecular weight 86,000, total substitution degree 2.5), 7.3 g of diisopropyl fumarate / monoethyl fumarate / 4-methoxyethyl cinnamate copolymer resin obtained by Synthesis Example 2 and tetrakis (2 , 4-Di-tert-butyl-5-methylphenyl) -4,4'-biphenylenediphosphonite in butyl acetate was dissolved in butyl acetate to form a 18% by weight resin solution, which was poured onto a polyethylene terephthalate film with a coater. After drying at a drying temperature of 60 ° C., an optical compensation film (resin composition) having a width of 150 mm was obtained (ethyl cellulose: 68% by weight, diisopropyl fumarate / monoethyl fumarate / 4-methoxy ethylcinnamate copolymer). Resin: 29% by weight, tetrakis (2,4-di-tert-butyl-5-methylphenyl ) -4,4′-biphenylenediphosphonite: 3% by weight). The obtained optical compensation film was cut into a 50 mm square and uniaxially stretched 2.0 times at 140 ° C. (thickness after stretching: 40 μm). The optical compensation film thus obtained was measured for light transmittance, haze, retardation characteristics, and wavelength dispersion characteristics. 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
16.5 g of cellulose acetate propionate (number average molecular weight 25,000, acetyl group = 7 mol%, propionyl group = 80 mol%, total substitution degree DS = 2.6), diethyl fumarate obtained by Synthesis Example 3 /7.3 g of monoethyl fumarate / 4-methoxycinnamic acid n-propyl copolymer resin and tetrakis (2,4-di-tert-butyl-5-methylphenyl) -4,4′-biphenylenediphosphonite 25 g was dissolved in butyl acetate to obtain a 18% by weight resin solution, which was poured on a polyethylene terephthalate film with a coater and dried at a drying temperature of 60 ° C. to obtain an optical compensation film (resin composition) having a width of 150 mm. (Cellulose acetate propionate: 66% by weight, diethyl fumarate / monoethyl fumarate / 4-methoxycinnamic acid n-propyl copolymer resin: 29% by weight, tetrakis (2,4-di-tert-butyl-5-methylphenyl) -4,4′-biphenylenediphosphonite: 5% by weight). The obtained optical compensation film was cut into a 50 mm square and uniaxially stretched 2.0 times at 140 ° C. (thickness after stretching: 40 μm). The optical compensation film thus obtained was measured for light transmittance, haze, retardation characteristics, and wavelength dispersion characteristics. 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
9.8 g of ethyl cellulose (number average molecular weight 86,000, total substitution degree 2.5), diethyl fumarate / monoethyl fumarate / 4-methoxyethyl cinnamate copolymer resin 11.5 g obtained by Synthesis Example 4 and bis 3.75 g of (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite is dissolved in butyl acetate to give an 18% by weight resin solution, which is poured onto a polyethylene terephthalate film with a coater and dried. After drying at a temperature of 60 ° C., an optical compensation film (resin composition) having a width of 150 mm was obtained (ethyl cellulose: 39% by weight, diethyl fumarate / monoethyl fumarate / 4-methoxyethyl cinnamate copolymer resin: 46 % By weight, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphie : 15 wt%). The obtained optical compensation film was cut into a 50 mm square and uniaxially stretched 2.0 times at 140 ° C. (thickness after stretching: 40 μm). The optical compensation film thus obtained was measured for light transmittance, haze, retardation characteristics, and wavelength dispersion characteristics. 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
Ethylcellulose (number average molecular weight 86,000, total substitution degree 2.5) 11.3 g, diisopropyl fumarate / mono n-butyl fumarate / 4-methoxycinnamic acid n-propyl copolymer resin obtained in Synthesis Example 5 10.8 g and 3 g of bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite were dissolved in butyl acetate to give a 18% by weight resin solution, which was poured onto a polyethylene terephthalate film with a coater and dried. After drying at 60 ° C., an optical compensation film (resin composition) having a width of 150 mm was obtained (ethylcellulose: 45% by weight, diisopropyl fumarate / mono-n-butyl fumarate / 4-methoxycinnamic acid n-propyl). Polymerized resin: 43% by weight, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphine Ito: 12 wt%). The obtained optical compensation film was cut into a 50 mm square and uniaxially stretched 2.0 times at 140 ° C. (thickness after stretching: 40 μm). The optical compensation film thus obtained was measured for light transmittance, haze, retardation characteristics, and wavelength dispersion characteristics. 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
15 g of cellulose acetate butyrate (number average molecular weight 33,000, acetyl group = 15 mol%, butyryl group = 70 mol%, total substitution degree DS = 2.55), diisopropyl fumarate / fumaric acid obtained in Synthesis Example 5 18 g of resin obtained by dissolving 8 g of mono-n-butyl / 4-methoxycinnamic acid n-propyl copolymer resin and 2 g of bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite in butyl acetate. The solution was poured onto a polyethylene terephthalate film with a coater and dried at a drying temperature of 60 ° C. to obtain an optical compensation film (resin composition) having a width of 150 mm (cellulose acetate butyrate: 60% by weight, diisopropyl fumarate). / Mono n-butyl fumarate / 4-methoxycinnamic acid n-propyl copolymer resin: 32 The amount%, bis (2,4-di -t- butyl-phenyl) pentaerythritol diphosphite: 8 wt%). The obtained optical compensation film was cut into a 50 mm square and uniaxially stretched 2.0 times at 140 ° C. (thickness after stretching: 40 μm). The optical compensation film thus obtained was measured for light transmittance, haze, retardation characteristics, and wavelength dispersion characteristics. 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.

Comparative Example 1
17 g of ethyl cellulose (number average molecular weight 86,000, total substitution degree 2.5) and 3 g of bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphate dissolved in butyl acetate are 18 wt. % Resin solution, poured on a polyethylene terephthalate film with a coater and dried at a drying temperature of 60 ° C. to obtain an optical compensation film (resin composition) having a width of 150 mm (ethylcellulose: 85% by weight, bis (2 , 6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite: 15% by weight). The obtained optical compensation film was cut into a 50 mm square and uniaxially stretched 2.0 times at 140 ° C. (thickness after stretching: 40 μm). The optical compensation film thus obtained was measured for light transmittance, haze, retardation characteristics, and wavelength dispersion characteristics. The results are also shown in Table 1.

  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 2
17 g of diisopropyl fumarate / monoethyl fumarate / n-propyl methoxycinnamate copolymer resin obtained in Synthesis Example 1, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphos 3 g of phyto is dissolved in butyl acetate to obtain a resin solution of 18% by weight, and is poured on a polyethylene terephthalate film with a coater and dried at a drying temperature of 60 ° C. to obtain an optical compensation film (resin composition) having a width of 150 mm. (Diisopropyl fumarate / monoethyl fumarate / n-propyl 4-methoxycinnamate copolymer resin: 85% by weight, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite: 15% by weight). The obtained optical compensation film was cut into a 50 mm square and uniaxially stretched 1.2 times at 150 ° C. (thickness after stretching: 40 μm). The optical compensation film thus obtained was measured for light transmittance, haze, retardation characteristics, and wavelength dispersion characteristics. The results are also shown in Table 1.

  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 3
Cellulose acetate propionate (number average molecular weight 25,000, acetyl group = 7 mol%, propionyl group = 80 mol%, total substitution degree DS = 2.6) 6 g, diisopropyl fumarate / fumarate obtained in Synthesis Example 1 18% by weight of 12% monoethyl-4-methoxycinnamate n-propyl copolymer resin and 6g bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite dissolved in butyl acetate The resin solution was poured onto a polyethylene terephthalate film with a coater and dried at a drying temperature of 60 ° C. to obtain an optical compensation film (resin composition) having a width of 150 mm (cellulose acetate propionate: 15% by weight, Diisopropyl fumarate / monoethyl fumarate / 4-methoxycinnamate n-propyl copolymer Resin: 75 wt%, bis (2,6-di -t- butyl-4-methylphenyl) pentaerythritol diphosphite: 10 wt%). The obtained optical compensation film was cut into a 50 mm square and uniaxially stretched 2.0 times at 140 ° C. (thickness after stretching: 40 μm). The optical compensation film thus obtained was measured for light transmittance, haze, retardation characteristics, and wavelength dispersion characteristics. The results are also shown in Table 1.

  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 (14)

Cellulose-based resin 30 to 85% by weight, fumaric acid ester-cinnamic acid ester copolymer resin 5 to 65% by weight containing fumarate residue units and cinnamic ester residue units, and the following general formula (1) The resin composition containing 1-20 weight% of phosphorus compounds shown and / or the phosphorus compound shown by following General formula (2).

(Wherein R ₁ , R ₂ and R ₃ each independently represent hydrogen, an alkyl group, a phenyl group or a cumyl group.)

(In the formula, R ₄ , R ₅ and R ₆ each independently represents hydrogen or an alkyl group.) The resin composition according to claim 1, wherein the cellulose resin is represented by the following general formula (3), and the substitution degree is 1.5 to 3.0.

(In formula, R < ₇ >, R <_8> , R < ₉ > shows hydrogen or a C1-C10 substituent each independently.) The resin composition according to claim 1 or 2, wherein the cellulose resin is selected from the group consisting of methyl cellulose, ethyl cellulose, triacetyl cellulose, cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate. object. The fumaric acid ester-cinnamate copolymer resin is a fumaric acid diester residue unit represented by the following general formula (4), 1 to 65 mol%, a fumaric acid monoester residue unit represented by the following general formula (5) 2. A fumaric acid ester-cinnamic acid ester copolymer containing 1 to 30 mol% and 98 to 5 mol% of a cinnamic acid ester residue unit represented by the following general formula (6): The resin composition according to any one of claims 3 to 4.

(In formula, R < ₁₀ >, R < ₁₁ > shows a C1-C12 alkyl group each independently.)

(In the formula, R ₁₂ represents an alkyl group having 1 to 12 carbon atoms.)

(In formula, R < ₁₃ >, R < ₁₄ > shows a C1-C12 alkyl group each independently.) The resin according to claim 4, wherein the fumarate diester residue unit is selected from the group consisting of a diethyl fumarate residue unit, a diisopropyl fumarate residue unit, and a di-t-butyl fumarate residue unit. Composition. A fumarate monoester residue unit is a monoethyl fumarate residue unit, a monoisopropyl fumarate residue unit, a mono-n-propyl fumarate residue unit, a mono-n-butyl fumarate residue unit, a mono-fumarate residue 6. The resin composition according to claim 4, wherein the resin composition is selected from the group consisting of 2-ethylhexyl residue units. Cinnamic acid ester residue unit is 4-methoxycinnamic acid methyl residue unit, 4-methoxycinnamic acid ethyl residue unit, 4-methoxycinnamic acid n-propyl residue unit, 4-methoxycinnamic acid The resin composition according to any one of claims 4 to 6, wherein the resin composition is selected from the group consisting of 2-ethylhexyl residue units. An optical compensation film comprising the resin composition according to any one of claims 1 to 7. The in-plane retardation (Re) represented by the following formula (a) is 50 to 300 nm, and the Nz coefficient represented by the following formula (b) is 0.35 <Nz <0.65. 8. An optical compensation film according to 8.
Re = (nx−ny) × d (a)
Nz = (nx-nz) / (nx-ny) (b) The ratio of the retardation at 589 nm to the film thickness Re (589) (nm) / film thickness (μm) is 4.0 nm / μm or more, 10 or 9, Optical compensation film. The resin composition is dissolved in a solvent, and the obtained resin solution is cast on a substrate, dried, and then peeled off from the substrate to obtain the resin composition according to any one of claims 8 to 10. The manufacturing method of the optical compensation film of description. The method for producing an optical compensation film according to claim 11, wherein a film having a thickness of 10 to 200 μm obtained by casting is stretched at least uniaxially. 13. The method for producing an optical compensation film according to claim 11, wherein a film having a thickness of 10 to 200 [mu] m obtained by casting is uniaxially stretched by 1.05 to 3.5 times. The film having a thickness of 10 to 200 μm obtained by casting is unbalanced biaxially stretched by 1.05 to 3.5 times in the length direction and 1.0 to 1.2 times in the width direction. Item 13. A method for producing an optical compensation film according to Item 11 or 12.