JP2002317074A - Cellulose acylate film and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a cellulose acrylate film having excellent planar state. SOLUTION: In addition to a cellulose acrylate, a carboxylic acid having a molecular structure containing at least two ester bonds or amide bonds or its salt contained in an amount of 0.01-2.5 wt.% based on the cellulose acrylate is added to a cellulose acrylate film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cellulose acylate film useful for a silver halide photographic material or a liquid crystal image display and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, an organic solvent of a cellulose acylate solution used in producing a cellulose acylate used for a silver halide photographic light-sensitive material or a liquid crystal image display device is a chlorine-containing carbon dioxide such as methylene chloride. Hydrogen is used. Methylene chloride (boiling point 40 ° C)
Has been conventionally used as a good solvent for cellulose acylate, and is preferably used because it has a low boiling point in the film-forming and drying steps of the production process and thus is easy to dry. Conversely, methylene chloride has a low boiling point and is easy to volatilize. Improvement is desired in this respect. Therefore, in order to solve this problem, the use of methylene chloride to prepare a cellulose acylate solution with a higher concentration and to reduce the amount of solvent used was studied, but the peeling from the metal support during casting was insufficient. The improvement was desired. Further, a search for a solvent for cellulose acylate other than methylene chloride has been made. Acetone (boiling point 56 ° C.), methyl acetate (boiling point 56 ° C.), tetrahydrofuran (boiling point 65 ° C.), 1,3-dioxolan ( Boiling point 75 ° C), 1,4-dioxane (boiling point 101 ° C)
and so on. However, these organic solvents have not obtained sufficient solubility for practical use by conventional dissolution methods.

[0003] As a solution to this, J. J. M. G. FIG. Cowie
Et al. (Makromol. Chem. 143, p. 105 (1971)), cellulose triacetate (degree of acetylation: 60.1% to 61.3%) was cooled from -80 ° C to -70 ° C in acetone. 0.5 to 5% by mass by heating
Are reported to be obtained. Such a method of dissolving cellulose acylate at a low temperature is called a cooling dissolution method. Also, Kenji Ude et al., Journal of the Textile Machinery Society, 34
Vol., Pp. 57-61 (1981), "Spinning from Cellulose Triacetate in Acetone Solution" describes a spinning technique using a cooling dissolution method.

In Japanese Patent Application Laid-Open Nos. 9-95538, 9-95544 and 9-95557,
With the above technology as background, dissolving cellulose acylate by a cooling dissolution method using a non-chlorine organic solvent is disclosed. The non-chlorine organic solvent used at that time is an organic solvent selected from ethers, ketones and esters, and a film is produced by dissolving cellulose acylate by a cooling dissolution method. It is described that acetone, 2-methoxyethyl acetate, cyclohexanone, ethyl formate, methyl acetate and the like are preferable as these specific organic solvents. However, in Japanese Patent Application Laid-Open No. 11-60752, the reproducibility of transparency and stability of a cellulose triacetate solution prepared without removing the low polymerization degree portion of the cellulose triacetate in these methods without prior removal is poor, and the method has been conventionally commercially available. In order to solve the complication that a photographic grade cellulose triacetate cannot be used as it is, it has been proposed to add fluoroalcohol to a cellulose acylate solution for improvement. However, there is a problem that the addition of fluoroalcohol has a problem that cellulose acylate has a poor surface condition due to its strong oil / water repellency.

On the other hand, a cellulose acylate film is
Generally, it is produced by a solvent casting method or a melt casting method. In the solvent casting method, a solution (dope) in which cellulose acylate is dissolved in a solvent is cast on a support, and the solvent is evaporated to form a film. In the melt casting method, a film obtained by melting cellulose acylate by heating is cast on a support and cooled to form a film. The solvent cast method can produce a good film having higher flatness than the melt cast method. For this reason, the solvent cast method is more commonly used in practical use. In the recent solvent casting method, it is an issue to improve the productivity of the film forming process by reducing the time required from casting the dope on the support to peeling off the formed film on the support. Has become. In particular, when obtaining a cellulose acylate film by a solvent casting method, in the case of a cellulose acylate solution cooled and dissolved using the above-described non-chlorinated organic solvent, it is difficult to peel the cellulose acylate film from the support. That is the problem.

[0006] In this method, cellulose acylate is cast on a band or a drum as a metal support, dried or cooled to form a strong gel film, and peeled from the support in a state containing an organic solvent. This is because it is difficult to peel off the cellulose acylate film from the support during the step of drying sufficiently thereafter. As described above, improvement has been demanded for a chlorine-based organic solvent of methylene chloride. However, it is more difficult to peel off a non-chlorine-based organic solvent, and the improvement has been desired. This is presumed to be due to strong adhesion between the cellulose acylate solution and the support. On the other hand, as a method for dissolving cellulose acylate in a non-chlorine organic solvent, high temperature and high pressure can be used, which is a useful means. However, the cellulose acylate solution produced by this method also has insufficient peeling from the cast metal support during its production, and its improvement has been desired. To solve this problem, Japanese Unexamined Patent Application Publication No. 10-31670
In the publication No. 1, the acid dissociation index pKa is 1.93 to 4.50.
[Preferably 2.0 to 4.4, more preferably 2.2.
To 4.3 (e.g. 2.5 to 4.0), especially 2.6 to
4.3 (e.g., about 2.6 to 4.0)] or an acid salt thereof is preferred as a release agent. However, as a drawback, the production of alkaline earth metals and fine salts contained in cellulose acylate in a cellulose acylate solution causes a problem of sticking to the system in a long casting process, and the improvement has been made. Was expected.

[0007]

When a cellulose acylate solution is prepared using a non-chlorine organic solvent according to a room temperature dissolution method, a cooling dissolution method or a high temperature and high pressure dissolution method, the solution is supported for drying after casting. There is a problem that it is difficult to peel from the body. It is desired to solve this problem and produce an excellent planar cellulose acylate film.

An object of the present invention is to provide a cellulose acylate film whose surface condition can be easily improved.
Another object of the present invention is to prepare a cellulose acylate solution using an organic solvent (preferably a non-chlorine-based organic solvent) according to a room temperature dissolution method, a cooling dissolution method or a high-temperature high-pressure dissolution method to obtain a cellulose acylate having excellent surface properties. It is also about producing films. It is a further object of the present invention to provide a cellulose acylate solution that can easily peel the film from the support for drying after casting, and can obtain excellent productivity.

[0009]

Means for Solving the Problems The present invention provides the following (1) to
(33) A cellulose acylate film, a method for producing the same, and a cellulose acylate solution. (1) Cellulose acylate and a carboxylic acid or a salt thereof in an amount of 0.01 to 2.5% by mass of the cellulose acylate, wherein the carboxylic acid or a salt thereof contains at least two ester bonds or amide bonds. A cellulose acylate film having a molecular structure.

(2) The cellulose acylate film according to (1), wherein the acyl substitution degree of the cellulose acylate is from 2.60 to 3.00. (3) The acyl substitution degree of cellulose acylate is 2.80.
The cellulose acylate film according to (2), wherein (4) The cellulose acylate film according to (1), wherein the degree of substitution of the cellulose acylate with an acetyl group is from 2.00 to 3.00.

(5) The degree of substitution of cellulose acylate with an acyl group having 3 to 22 carbon atoms is 0.1 to 0.2.
The cellulose acylate film according to (1), which has a value of from 00 to 0.80. (6) The cellulose acylate is substituted with an acetyl group and an acyl group having 3 to 22 carbon atoms, and at least 30% of the acyl groups having 3 to 22 carbon atoms are substituted as a substituent of the 6-position hydroxyl group. The cellulose acylate film according to (1), which is present.

(7) The cellulose acylate film according to (1), wherein the degree of acyl substitution at the 6-position of the cellulose acylate is from 0.80 to 1.00. (8) The cellulose acylate film according to (1), wherein the degree of acyl substitution at the 6-position of the cellulose acylate is 0.85 to 1.00. (9) The cellulose acylate film according to (1), wherein the cellulose acylate has a viscosity average degree of polymerization of 250 to 550.

(10) The cellulose acylate film according to (1), wherein the carboxylic acid or a salt thereof has at least one carboxyl group having an acid dissociation index of 4.4 or less. (11) The cellulose acylate film according to (1), wherein the carboxylic acid or a salt thereof has at least two carboxyl groups. (12) The cellulose acylate film according to (1), wherein the carboxylic acid or a salt thereof has at least three carboxyl groups.

(13) The cellulose acylate film according to (1), wherein the carboxylic acid is an oligomer having 3 to 10 repeating units linked by 2 to 9 ester bonds or amide bonds. (14) The cellulose acylate film according to (1), which is for a protective layer of an optical material and has a thickness of 10 to 200 μm. (15) The cellulose acylate film according to (1), which is for a support of a silver halide photographic material and has a thickness of 30 to 250 μm.

(16) A method for producing a cellulose acylate film by applying a cellulose acylate solution obtained by dissolving cellulose acylate in an organic solvent, wherein the cellulose acylate solution contains 0.002 to 0.5% by mass.
And a carboxylic acid or a salt thereof, wherein the carboxylic acid or a salt thereof has a molecular structure containing at least two ester bonds or amide bonds.

(17) The method according to (16), wherein the organic solvent comprises a substantially non-chlorine organic solvent. (18) The organic solvent is selected from the group consisting of ethers having 2 to 12 carbon atoms, ketones having 3 to 12 carbon atoms, and esters having 2 to 12 carbon atoms (1
The production method according to 7).

(19) The ether is diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-
(18) The production method according to (18), which is selected from the group consisting of dioxane, 1,3-dioxane, 1,3-dioxolan, tetrahydrofuran, anisole, and phenetole. (20) The ketone is selected from the group consisting of acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and methylcyclohexanone (18)
The production method described in 1.

(21) The ester is ethyl formate,
(18) The production method according to (18), which is selected from the group consisting of propyl formate, pentyl formate, methyl acetate, ethyl acetate, propyl acetate, and pentyl acetate. (22) The organic solvent is a mixture of three or more different solvents, and the first solvent is selected from the group consisting of methyl acetate, ethyl acetate, methyl formate, ethyl formate, acetone, dioxolan and dioxane; The second solvent is selected from the group consisting of ketones having 4 to 7 carbon atoms and acetoacetate, and the third solvent is
(17) The production method according to (17), which is selected from the group consisting of alcohols and hydrocarbons having 1 to 10 carbon atoms.

(23) The organic solvent contains the first solvent at a ratio of 20 to 90% by mass, the second solvent at a ratio of 5 to 60% by mass, and the third solvent at a ratio of 5 to 30% by mass (2)
The production method according to 2). (24) The organic solvent is a mixture of three or more different solvents, and the first solvent and the second solvent are methyl acetate, ethyl acetate, methyl formate, ethyl formate, acetone,
Selected from the group consisting of dioxolane and dioxane,
And the third solvent is selected from the group consisting of alcohols and hydrocarbons having 1 to 10 carbon atoms (17)
The production method described in 1.

(25) The organic solvent contains 20 to 90% by mass of the first solvent, 5 to 60% by mass of the second solvent, and 5 to 30% by mass of the third solvent ( 24. The production method according to 24). (26) The organic solvent is methylene chloride (1
The production method according to 6). (27) a step of swelling a mixture of cellulose acylate and an organic solvent at 10 to 40 ° C. and a step of heating the swollen mixture to 0 to 57 ° C. to dissolve the cellulose acylate in the organic solvent; (16) The production method according to (16), wherein an acetate solution is used.

(28) a step of swelling the mixture of cellulose acylate and the organic solvent at -10 to 55 ° C, a step of cooling the swollen mixture to -100 to -10 ° C, and a step of cooling the cooled mixture to 0 to 57 ° C. The production method according to (16), wherein a cellulose acetate solution obtained by dissolving cellulose acylate in an organic solvent is used in the step of heating to a temperature of ° C. (29) a step of swelling a mixture of cellulose acylate and an organic solvent at −10 to 55 ° C., a step of heating the swollen mixture at 60 to 240 ° C. at 0.2 to 30 MPa, and a step of heating the heated mixture to 0 to 240 ° C. (16) The production method according to (16), wherein a cellulose acetate solution in which cellulose acylate is dissolved in an organic solvent is used by cooling to 57 ° C.

(30) As cellulose acylate, 9
Using cellulose acylate particles in which 0% by mass or more have a particle size of 0.1 to 5 mm, a treatment of filtering the cellulose acylate solution before application is performed (16).
The production method described in 1. (31) Cellulose acylate solution: 0.1 to 20% by mass of plasticizer with respect to cellulose acylate, 0.001 to 5% by mass of ultraviolet absorber with respect to cellulose acylate, and fine particles of cellulose acylate 0.001 to 5% by mass, the fluorine-based surfactant is 0.001 to 2% by mass based on the cellulose acylate, or the oil gelling agent is 0.001 to 2% by mass based on the cellulose acylate. The production method according to (16). (32) The production method according to (16), wherein two or more types of cellulose acylate solutions are co-cast in the casting step.

(33) A cellulose acylate solution in which cellulose acylate is dissolved in an organic solvent,
A cellulose acylate solution comprising a carboxylic acid or a salt thereof in an amount of 0.002 to 0.5% by mass, wherein the carboxylic acid or a salt thereof has a molecular structure containing at least two ester bonds or amide bonds. .

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Cellulose acylate is a cellulose derivative (cellulose ester) in which a hydrogen atom of a hydroxyl group of cellulose is substituted with an acyl group. The acyl group is generally an acetyl group (SA), but may be an acyl group (SB) having 3 or more (preferably 3 to 22) carbon atoms. The sum of the degrees of substitution of SA + SB is
Generally, it is 2.60 to 3.00, and the substitution degree of SB is 0.
00 to 0.80. Β- constituting cellulose
The 1,4-linked glucose unit has a free hydroxyl group at the 2-, 3- and 6-positions. Cellulose acylate is a polymer in which some or all of these hydroxyl groups are esterified with an acyl group. The degree of acyl substitution was determined for each of the 2-, 3- and 6-positions.
The ratio of cellulose esterification (100% esterification means substitution degree 1). The sum of the degrees of substitution of SA and SB in the hydroxyl group is preferably from 2.70 to 2.96, and more preferably from 2.80 to 2.95. Further, the substitution degree of SB is preferably from 0.00 to 0.80, and more preferably from 0.00 to 0.60.

In the cellulose acylate, it is particularly preferable that the degree of substitution of the cellulose with a hydroxyl group satisfies all of the following formulas (I) to (III). (I) 2.6 ≦ SA + SB ≦ 3.0 (II) 2.0 ≦ SA ≦ 3.0 (III) 0 ≦ SB ≦ 0.8 [wherein SA and SB are substituted by hydroxyl groups of cellulose. Is a substituent of an acyl group, SA is the degree of substitution of an acetyl group, and SB is the degree of substitution of an acyl group having 3 to 22 carbon atoms.]

As for the degree of substitution (SB) of an acyl group having 3 to 22 carbon atoms, it is preferable that at least 28% of the substituent is a substituent of a 6-position hydroxyl group, and at least 30% is a substituent of a 6-position hydroxyl group. More preferably, 31% or more is more preferably a substituent of a 6-position hydroxyl group, still more preferably 3% or more.
Most preferably, 2% or more is a substituent of the 6-position hydroxyl group. The sum of the degrees of substitution between the SA and SB at the 6-position of the cellulose acylate is preferably 0.80 or more.
It is more preferably at least 85, most preferably at least 0.90.

Acyl group having 3 to 22 carbon atoms (SB)
Is defined as -CO-R, wherein R is an aliphatic group, an aromatic group, or a heterocyclic group. R is preferably an aliphatic group or an aromatic group. The aliphatic group is an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group or a substituted alkynyl group. The aromatic group is an aryl group or a substituted aryl group. 3 carbon atoms
Examples of the acyl group of -22 include propionyl, butyryl,
Valeryl, hexanoyl, heptanoyl, octanoyl, nonanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, isobutyryl, t-butyryl, cyclohexanoyl, oleoyl, benzoyl, naphthoyl and cinnamoyl. Propionyl, butyryl, dodecanoyl, octadecanoyl, t-butyryl, oleoyl, benzoyl, naphthoyl and cinnamoyl are preferred.

The basic principle of the method for synthesizing cellulose acylate is described in Migita et al., Wood Chemistry, pp. 180-190 (Kyoritsu Shuppan, 1968). A typical synthesis method is a liquid phase acetylation method using a carboxylic anhydride-acetic acid-sulfuric acid catalyst. Specifically, after a cellulose raw material such as cotton linter or wood pulp is pretreated with an appropriate amount of acetic acid, it is put into a carboxylation mixed solution that has been cooled in advance to be esterified, and complete cellulose acylate (second, third and sixth positions) is obtained. The total degree of acyl substitution at the position is approximately 3.00). The carboxylation mixture generally contains acetic acid as a solvent, carboxylic anhydride as an esterifying agent, and sulfuric acid as a catalyst. The carboxylic anhydride is usually used in a stoichiometric excess of the total amount of the cellulose reacting therewith and the water present in the system. After the completion of the acylation reaction, a neutralizing agent (for example, calcium, magnesium, iron, aluminum or zinc) is used for hydrolysis of excess carboxylic anhydride remaining in the system and neutralization of a part of the esterification catalyst. (Carbonate, acetate or oxide). Next, the obtained complete cellulose acylate is saponified and aged by keeping at 50 to 90 ° C. in the presence of a small amount of an acetylation reaction catalyst (generally, residual sulfuric acid),
The cellulose acylate having the desired degree of acyl substitution and degree of polymerization is changed. When the desired cellulose acylate is obtained, the catalyst remaining in the system may be completely neutralized using the neutralizing agent as described above, or may be neutralized with water or dilute sulfuric acid. Put the cellulose acylate solution (or into the cellulose acylate solution,
Water or diluted sulfuric acid is added) to separate the cellulose acylate, and the cellulose acylate is obtained by washing and stabilizing.

It is preferable that the polymer component of the cellulose acylate film is substantially composed of cellulose acylate having the above definition. "Substantially" means 90% by weight or more (preferably 95% by weight or more, more preferably 98% by weight or more, and most preferably 99% by weight or more) of the polymer component. It is preferable to use cellulose acylate particles as a raw material for producing a film. 90% by mass of the particles used
The above preferably has a particle diameter of 0.5 to 5 mm. Further, 50% by mass or more of the particles used is 1 to 4%.
It preferably has a particle size of mm. It is preferable that the cellulose acylate particles have a shape as close to spherical as possible.

The degree of polymerization of cellulose acylate is preferably from 200 to 700 in terms of viscosity average degree of polymerization.
0 to 550, more preferably 250 to 400
Is more preferable, and most preferably 250 to 350. The average degree of polymerization was determined by the limiting viscosity method of Uda et al.
105-120, 1962). The viscosity average polymerization degree is also described in JP-A-9-95538. The viscosity average degree of polymerization is determined by the following equation from the intrinsic viscosity [η] of cellulose acetate measured by an Ostwald viscometer. (1) DP = [η] / Km where [η] is the intrinsic viscosity of cellulose acetate, and Km is a constant 6 × 10 −4. When the viscosity average degree of polymerization (DP) is 290 or more, the viscosity average degree of polymerization and the concentrated solution viscosity (η) according to the falling ball viscosity method are represented by the following formula (2).
Is preferably satisfied. (2) 2.814 × ln (DP) −11.753 ≦ ln
(Η) ≦ 6.29 × ln (DP) −31.469 In the formula, DP is a value of a viscosity average degree of polymerization of 290 or more,
η is the transit time (seconds) between the marked lines in the falling ball viscosity method. The above formula (2) is obtained by plotting the viscosity-average degree of polymerization and the viscosity of the concentrated solution and calculating from the results.

When the low molecular components are removed, the average molecular weight (degree of polymerization) increases, but the viscosity is lower than that of ordinary cellulose acylate, which is useful. Cellulose acylate having a small amount of low molecular components can be obtained by removing low molecular components from cellulose acylate synthesized by an ordinary method. The removal of low molecular components can be performed by washing the cellulose acylate with a suitable organic solvent. Examples of the organic solvent include ketones (eg, acetone), acetates (eg, methyl acetate), and cellosolves (eg, methyl cellosolve). In the present invention, it is preferable to use ketones, especially acetone. To increase the efficiency of removing low molecular components,
It is preferable to control the particle size by crushing or sieving the cellulose acylate particles before washing. In the case of producing cellulose silicate having a small amount of low molecular components, the amount of the sulfuric acid catalyst in the acetylation reaction is preferably adjusted to 5 to 25 parts by mass based on 100 parts by mass of cellulose. When the amount of the sulfuric acid catalyst is in the above range, cellulose acylate which is preferable in terms of molecular weight distribution (uniform molecular weight distribution) can be synthesized. When the cellulose acylate is used for producing a film, the water content of the cellulose acylate is preferably 2% by mass or less, more preferably 1% by mass or less,
Most preferably, it is 0.7% by mass or less. Common (eg, commercially available) cellulose acylates have a moisture content of 2.5 to 5% by weight. Therefore, when a general cellulose acylate is used, it is preferable to reduce the water content to 2% by mass or less by drying. Drying can be performed by various known means.

In the present invention, a carboxylic acid having a molecular structure containing at least two ester bonds or amide bonds or a salt thereof is used. The amount of carboxylic acid or a salt thereof contained in the film is 0.01% of cellulose acylate.
To 2.5% by mass, and 0.015 to 1.0% by mass.
And more preferably 0.025 to 0.5% by mass. The amount of the carboxylic acid or its salt contained in the cellulose acylate solution is 0.1%.
002 to 0.5% by mass, and 0.003 to 0.2
%, More preferably 0.005 to 0.1% by mass. The carboxylic acid or its salt has an acid dissociation index (pKa) of 4 measured at 25 ° C.
It preferably has at least one carboxyl group (which may be in the form of a salt) of 4 or less. The carboxylic acid or a salt thereof preferably has at least one carboxyl group having a pKa of 1.9 to 4.4, and has at least one carboxyl group having a pKa of 2.0 to 4.0. More preferably, it has at least one carboxyl group having a pKa of 2.0 to 3.9.

The carboxylic acid used in the present invention has a molecular structure containing at least two ester bonds or amide bonds. In other words, the carboxylic acid used in the present invention is
At least three repeating units are formed by an ester bond (-C
O-O-, -O-CO-) or an amide bond (-CO-
(NH-, -NH-CO-). The repeating unit is basically represented by the following (I) to (VI)
Can be classified into six types. ^{(I) -CO-L 1 -CO-} (II) -O-L 2 -O- (III) -NH-L 3 -NH- (IV) -CO-L 4 -O- (V) -CO- L ⁵ -NH- (VI) -OL ⁶ -NH- wherein L ¹ is a single bond, a divalent aliphatic group or a divalent aromatic group, and L ^{2 to} L ⁶ are A divalent aliphatic group or a divalent aromatic group.

The repeating units (IV) and (V) alone can constitute the carboxylic acid used in the present invention. Other repeating units form an ester bond or an amide bond by combining two or more kinds. The polymerization degree (number of repeating units) of the carboxylic acid or its salt is preferably from 3 to 5,000, more preferably from 4 to 1,000, and most preferably from 5 to 500. Examples of the monomer that forms the repeating unit include (I) a polycarboxylic acid, (II) a polyhydric alcohol or a polyphenol (polyol), (III) a polyamine,
(IV) hydroxy acids, (V) amino acids, (VI) amino alcohols or amino phenols can be used.

(I) Examples of polycarboxylic acids include oxalic acid (1.27), malonic acid (2.65) and succinic acid (4.
00), glutaric acid (4.13), adipic acid (4.2)
6), pimelic acid (4.31), azelaic acid (4.3)
9), fumaric acid (2.85), malic acid (3.24),
Tartaric acid (2.82-2.99), citric acid (2.8)
7), phthalic acid (2.75), isophthalic acid (3.5
0), terephthalic acid (3.54), trimellitic acid, 4
-Methylphthalic acid, 2,6-pyridinedicarboxylic acid (2.09), aspartic acid (1.93) and glutamic acid (2.18). The number in parentheses is
This is the lowest pKa value of the carboxyl group (plural) (hereinafter the same). Malonic, succinic, glutaric, fumaric, malic, tartaric and citric acids are preferred.

(II) Examples of polyhydric alcohols or phenols (polyols) include ethylene glycol, propylene glycol, butylene glycol, hexane glycol, cyclohexane dialcohol, cyclohexane dimethanol, dihydroxybenzene, trihydroxybenzene, glycerin, Glycidol, sorbitol,
Sorbitan, trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, polyethylene glycol (degree of polymerization: 2 to 10)
0), polypropylene glycol (degree of polymerization: 2 to 10)
0), polybutylene glycol (degree of polymerization: 2 to 10)
0), ethylene glycol / propylene glycol copolymer (degree of polymerization: 2 to 100) and polyglycerin (degree of polymerization: 2 to 100). (III) Examples of polyvalent amines include ethylenediamine, propylenediamine, butylenediamine, hexanediamine,
Cyclohexanediamine, diaminobenzene and xylenediamine are included.

(IV) Examples of hydroxy acids include malic acid (3.24), tartaric acid (2.82-2.99) and citric acid (2.87). (V) Examples of amino acids include aspartic acid (1.93)
And glutamic acid (2.18). (VI) Examples of amino alcohols include ethanolamine and propanolamine.

When the carboxyl group of the carboxylic acid forms a salt, the counter ion is preferably a metal ion or an ammonium ion, more preferably a metal ion.
Alkali metal ions are most preferred. Examples of a carboxylic acid having a molecular structure containing at least two ester bonds or amide bonds or a salt thereof are shown below.

[0039]

Embedded image

[0040]

Embedded image

[0041]

Embedded image

[0042]

Embedded image

[0043]

Embedded image

[0044]

Embedded image

[0045]

Embedded image

[0046]

Embedded image

In the cellulose acylate solution, various additives (for example, a plasticizer, an ultraviolet ray inhibitor, a deterioration inhibitor, fine particles, an optical property modifier, an oil gelling agent) depending on the use in each preparation step are added. Can be. The doping may be added at any time during the dope preparation step, but may be performed by adding a step of adding and preparing an additive to the last preparation step of the dope preparation step. The plasticizer is preferably a liquid having a boiling point of 200 or more and a liquid at 25 ° C or a solid having a melting point of 25 to 250 ° C. More preferably, a plasticizer which is liquid at a boiling point of 25 ° C. or higher at 250 ° C. or higher, or a solid having a melting point of 25 to 200 ° C. is exemplified. Phosphoric acid esters or carboxylic acid esters are preferably used as the plasticizer. Examples of phosphate esters include triphenyl phosphate (TPP) and tricresyl phosphate (TCP), cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate. Representative carboxylic esters are phthalic esters and citric esters. Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethylhexyl phthalate (DEH).
P) is included. Examples of citrate esters include O-acetyl triethyl citrate (OACTE) and O-acetyl tributyl citrate (OACTB), acetyl triethyl citrate, acetyl tributyl citrate, O-acetyl tri (ethyloxycarbonyl methylene) citrate Esters are included. These preferred plasticizers
Except for TPP (melting point: about 50 ° C.) at 25 ° C., it is liquid and has a boiling point of 250 ° C. or more.

Examples of other carboxylic esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate and various trimellitate esters. Examples of glycolic acid esters include triacetin, tributyrin, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, methyl phthalyl methyl glycolate, propyl phthalyl Propyl glycolate, butylphthalylbutyl glycolate, octylphthalyloctyl glycolate and the like can be mentioned. Among them, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, dimethyl phthalate,
Preferred are diethyl phthalate, dibutyl phthalate, dioctyl phthalate, diethylhexyl phthalate, triacetin, and ethyl phthalyl ethyl glycolate. Particularly, triphenyl phosphate, diethyl phthalate, and ethyl phthalyl ethyl glycolate are preferred. These plasticizers may be used alone or in combination of two or more. The amount of the plasticizer added is 2 to 30 with respect to the cellulose acylate.
It is preferable that the content be 5% by mass, particularly 5 to 20% by mass. JP-A No. 11-1 as a plasticizer for reducing optical anisotropy
(445) (Di) pentaerythritol esters described in JP-A-11-246704, glycerol esters described in JP-A-11-246704, diglycerol esters described in JP-A-2000-63560, JP-A-11-9
Citric acid esters described in JP-A-2574;
Substituted phenyl phosphates described in 1-90946 are preferably used.

To the cellulose acylate film, a deterioration inhibitor (eg, an antioxidant, a peroxide decomposer, a radical inhibitor, a metal deactivator, an acid scavenger, an amine) or an ultraviolet inhibitor is added. Is also good. These degradation inhibitors and UV inhibitors are described in JP-A-60-235852, JP-A-3-199201, JP-A-5-1907073, and JP-A-5-1907073.
194789, 5-271471, 6-107
No. 854, No. 6-118233, No. 6-148430
Nos. 7-11056, 7-11055, 7-
No. 11056, No. 8-29619, No. 8-23950
9, JP-A-2000-204173 and JP-A-200-204173
It is described in each publication of JP-A-193821. These addition amounts are 0.01 to 1% by mass of the solution (dope) to be prepared.
And more preferably 0.01 to 0.08% by mass. When the addition amount is less than 0.01% by mass, the effect of the deterioration inhibitor is hardly recognized.
If the amount exceeds 1% by mass, bleed-out (bleeding out) of the deterioration inhibitor on the film surface may be observed. The deterioration inhibitor is preferably a liquid having a boiling point of 200 or more and a temperature of 25 ° C. or a solid having a melting point of 25 to 250 ° C. More preferably, a deterioration inhibitor which is liquid at a boiling point of 25 ° C. or higher at 250 ° C. or higher or solid at a melting point of 25 to 200 ° C. is exemplified. When the deterioration inhibitor is a liquid, its purification is usually carried out by distillation under reduced pressure, but the higher the vacuum, the more preferable it is.
It is also particularly preferable to purify using a molecular distillation apparatus or the like. In the case where the plasticizer is a solid, it is generally carried out by recrystallization using a solvent, filtration, washing and drying. As the deterioration inhibitor, for example, JP-A-5-1
Preferable examples include a basic compound having a pKa of 4 or more described in Japanese Patent No. 94789. For example, primary, secondary, and tertiary amines and aromatic base compounds are preferable. Specific examples include tributylamine, trihexylamine, trioctylamine, dodecyl-dibutylamine, octadecyl-dimethylamine, tribenzylamine, diethylaminobenzene, and the like. Compounds A-1 to A-73 and B- described in (1) and (2)
1-B-67 can be used. A particularly preferred example of the deterioration inhibitor is butylated hydroxytoluene (BHT).

The ultraviolet absorber preferably used for the cellulose acylate film will be described. Specific examples of the ultraviolet absorber include oxybenzophenone-based compounds,
Examples include benzotriazole-based compounds, salicylic acid ester-based compounds, benzophenone-based compounds, cyanoacrylate-based compounds, nickel complex salt-based compounds, and the like. Hereinafter, specific examples of the benzotriazole-based ultraviolet absorber will be described, but the present invention is not limited thereto. 2- (2'-hydroxy-5'-methylphenyl) benzotriazole,
2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole, (2′-hydroxy-3 ′,
5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-
(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl) benzotriazole, 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6 -(2H-benzotriazol-2-yl) phenol), 2- (2'-hydroxy-
3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfo Benzophenone, bis (2-methoxy-4-hydroxy-5-benzoylphenylmethane), (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,
5-di-tert-butylanilino) -1,3,5-triazine, 2 (2′-hydroxy-3 ′, 5′-di-tert-
Butylphenyl) -5-chlorobenzotriazole,
(2 (2′-hydroxy-3 ′, 5′-di-tert-amylphenyl) -5-chlorobenzotriazole, 2,6
-Di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-
4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-tert-butyl-5-
Methyl-4-hydroxyphenyl) propionate],
1,6-hexanediol-bis [3- (3,5-di-
tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4
-Hydroxy-3,5-di-tert-butylanilino)-
1,3,5-triazine, 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3-
(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 1,3,5- Trimethyl-2,4,6-
Tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate and the like can be mentioned.

In particular, (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine, 2 (2'-hydroxy- 3 ', 5'-di-tert-butylphenyl)-
5-chlorobenzotriazole, (2 (2'-hydroxy-3 ', 5'-di-tert-amylphenyl) -5-chlorobenzotriazole, 2,6-di-tert-butyl-
p-cresol, pentaerythrityl-tetrakis [3
-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate] are preferred. Further, for example, a hydrazine-based metal deactivator such as N, N'-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine or tris (2,4-
A phosphorus-based processing stabilizer such as di-tert-butylphenyl) phosphite may be used in combination. The addition amount of these compounds is 0.01% by mass relative to cellulose acylate.
To 5% by mass, preferably 0.05 to 3% by mass.
Is more preferable.

A retardation increasing agent for controlling optical anisotropy is optionally added. In order to adjust the retardation of the cellulose acylate film, an aromatic compound having at least two aromatic rings is preferably used as a retardation increasing agent. Further, a colorant compound for preventing light piping may be added to the support for the light-sensitive material.
The content of the coloring agent is preferably from 10 to 1000 ppm by mass relative to cellulose acylate,
More preferably, it is 0 to 500 ppm. By including a coloring agent in this manner, the light piping of the cellulose acylate film can be reduced, and the yellow tint can be improved. These compounds may be added together with the cellulose acylate or the solvent when preparing the cellulose acylate solution, or may be added during or after the solution preparation.

Further, various additives may be added to the cellulose acylate solution at any stage before the preparation of the solution or after the preparation, if necessary. Examples of additives include inorganic fine particles, heat stabilizers such as alkaline earth metal salts,
Examples include an antistatic agent, a flame retardant, a lubricant, and an oil agent. At this time, the inorganic fine particles used have a role as an anti-smudge agent and an antistatic property. In that case, the hardness of the metal or metal compound is not particularly limited, but the Mohs hardness is preferably 1 to 10, and more preferably 2 to 10. or,
Organic fine particles are also preferably used, and examples thereof include cross-linked polystyrene, cross-linked polymethyl methacrylate, and cross-linked triazine resin. Particularly in the present invention,
When handling the cellulose acylate film, fine particles are generally added in order to prevent the film from being damaged or from being deteriorated in transportability. Preferred specific examples of these matting agents include, as inorganic compounds, compounds containing silicon, silicon dioxide, titanium oxide, zinc oxide, aluminum oxide, barium oxide, zirconium oxide, strongtium oxide, antimony oxide, tin oxide, and tin oxide.・ Antimony, calcium carbonate, talc,
Clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate, and the like are preferable, and inorganic compounds containing silicon and zirconium oxide are more preferable.
For example, Aerosil R972, R974, R812, 2
Commercial products having trade names such as 00, 300, R202, OX50, and TT600 (all manufactured by Nippon Aerosil Co., Ltd.) can be used. As the fine particles of zirconium oxide, for example, those commercially available under trade names such as Aerosil R976 and R811 (both manufactured by Nippon Aerosil Co., Ltd.) can be used.

As the organic compound, for example, polymers such as silicone resin, fluorine resin and acrylic resin are preferable, and among them, silicone resin is preferably used. Among the silicone resins, those having a three-dimensional network structure are particularly preferable.
Commercial products having a trade name such as 0 (all manufactured by Toshiba Silicone Co., Ltd.) can be used. The primary average particle diameter of these fine particles is preferably 0.001 to 20 μm, more preferably 0.001 to 10 μm, and still more preferably 0.00, from the viewpoint of suppressing haze.
2-1 μm, particularly preferably 0.005-0.5 μm.
5 μm. The measurement of the primary average particle diameter of the fine particles is obtained by measuring the particles with an average particle diameter using a transmission electron microscope. The apparent specific gravity of the fine particles is preferably 70 g / L or more, more preferably 90 to 200 g / L, and particularly preferably 100 to 200 g / L. For example, Aerosil 200V, Aerosil R972V
(These are manufactured by Nippon Aerosil Co., Ltd.), and they can be used.

Next, in the present invention, an oil gelling agent may be added to the solution, which is useful for improving casting properties and film surface condition. The material of the oil gelling agent is not limited as long as it can be added to the cellulose acylate solution to gel the solution. Here, in the present invention, gelation is a solution of an organic solvent of cellulose acylate, by adding an oil gelling agent, interaction between the oil gelling agents or with cellulose acylate, and furthermore, with the organic solvent and the like. A state in which a solution does not flow or solidifies due to interaction. That is, the oil gelling agent of the present invention is not a covalent bond such as a hydrogen bond, an electrostatic interaction, a coordination bond, a van der Waals force, or a π-π electron interaction in an organic solvent of cellulose acylate. One that forms a gel structure by self-association using a strong interaction as a driving force can be used. As these oil gelling agents, known literature (for example, J. Chem. So
c.Japan, Ind.Chem.Soc., 46,779 (1943), J.Am.Chem.So
c., 111,5542 (1989), J.Chem.Soc., Chem.Commun., 1993,3.
90, Angew.Chem.Int.Ed.Engl., 35, 1949 (1996), Chem.Le.
tt., 1996, 885, J. Chem. Soc., Chem. Commun., 1997, 545)
It is described in. In addition, the collection of polymer papers (VOL.55, No.1
0,585-589 (Oct., 1998)), surface (VOL.36, No.6,291-
303 (1998)), Textile and Industry (VOL.56, No.11, 329-332)
(2000)), JP-A-7-247473, JP-A-7-2
47474, JP-A-7-247475, JP-A-7-247
300758, JP-A-10-265761, JP-A-7-208446, JP-A-2000-3003, JP-A-5-230435, and JP-A-5-320617
The materials described in each gazette of the issue can be applied.

Preferred oil gelling agents are 1, 2, 3,
4-dibenzylidene-D-sorbitol, 12-hydroxystearic acid, amino acid derivative (N-lauroyl-
L-glutamic acid-α, etc.), cyclic dipeptides (2.5
-Diketopiperazine derivative), γ-bis-n-butylamine, spin-labeled steroid, cholesterol derivative, phenol cyclic oligomer, 2,3-bis-n-
Hexadecyloxyanthracene, butyrolactone derivative, urea derivative, vitamin H derivative, gluconamide derivative, cholic acid derivative, barbituric acid derivative and triaminopyrimidine derivative mixture, cyclohexanediamine derivative, cyclohexanetricarboxylic acid derivative, alone However, a plurality of mixtures may be used. Further, it is also preferable that the oil gelling agent is a cyclic dipeptide selected from the group consisting of valine, leucine, isoleucine, aspartic acid, aspartic acid ester, glutamic acid, glutamic acid ester and phenylalanine. It is also preferable that the oil gelling agent is an α-aminolactam derivative. The content of the oil gelling agent in the cellulose acylate solution is 0.01 to 5% by mass, preferably 0.02 to 4% by mass, and more preferably 0.02 to 3% by mass.

Next, an organic solvent used for preparing a solution of cellulose acylate will be described. In the present invention, cellulose acylate is dissolved and cast,
The organic solvent is not particularly limited as long as the film can be formed. These may be chlorinated organic solvents or non-chlorinated organic solvents. For example, examples of the chlorine-based organic solvent include methylene chloride and chloroform, and methylene chloride is particularly preferable. However, these chlorine-based organic solvents have recently been concerned about their environmental safety, and it is preferable to use non-chlorine-based organic solvents. The solvents preferably used in the present invention will be described in detail below. That is, it is preferable to produce a cellulose acylate film by a solvent casting method,
The film is manufactured using a solution (dope) in which cellulose acylate is dissolved in an organic solvent.

The organic solvent preferably used as the main solvent is preferably a solvent selected from esters, ketones and ethers having 3 to 12 carbon atoms. Esters, ketones, and ethers may have a cyclic structure. Functional groups of esters, ketones and ethers (i.e., -O
A compound having two or more of any of —, —CO— and —COO—) can also be used as the main solvent, and may have another functional group such as an alcoholic hydroxyl group. In the case of a main solvent having two or more types of functional groups,
The number of carbon atoms may be within the specified range for the compound having any functional group. Examples of the esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate. Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and methylcyclohexanone. 3 to 12 carbon atoms
Examples of ethers include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolan, tetrahydrofuran, anisole and phenetole. Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol.

Here, these main solvents for the cellulose acylate used in the present invention can show a preferable range in the solubility parameter. That is, the cellulose acylate used in the present invention has a solubility parameter of 17 to 22. There are many books describing the solubility parameter. Brandru
p, E. H et al. (Polymer Handbook (fourth editio
n), VII / 671 to VII / 714). Among them, the organic solvent which can be effectively used for the cellulose acylate of the present invention preferably has a solubility parameter of 19 to 21 MPa1 / 2. Examples of the organic solvent having a solubility parameter of 19 to 21 MPa1 / 2 include methyl ethyl ketone (19), cyclohexanone (20.3), cyclopentanone (20.9),
Methyl acetate (19.6), 2-butoxyethanol (1
9.4), methylene chloride (20.3), dioxane (1
9.6), 1,3-dioxolane (19.8), acetone (20.3), ethyl formate (19.2), methyl acetoacetate (about 20) and tetrahydrofuran (19.
4) and the like. Among them, methyl acetate, acetone, methyl acetoacetate, cyclopentanone,
Most preferred are cyclohexanone, methylene chloride and the like.
These are described in JP-A-9-95538. Further, N-methylpyrrolidone described in JP-A-61-124470 and JP-A-11-60807 are disclosed.
JP-A-112-6
1,3-dimethyl-2-imidazolidinone described in JP-A-3534 is also used.

The solvent used for the above-mentioned cellulose acylate is selected from the various viewpoints described above, and is preferably as follows. That is, the preferred solvent for cellulose acylate is a mixed solvent of three or more different solvents, and the first solvent is at least one selected from methyl acetate, ethyl acetate, methyl formate, ethyl formate, acetone, dioxolan, dioxane or Or a mixture thereof, wherein the second solvent is selected from ketones or acetoacetic esters having 4 to 7 carbon atoms, and the third solvent is selected from alcohols or hydrocarbons having 1 to 10 carbon atoms as the third solvent. , More preferably 1 to 1 carbon atoms
8 alcohol. When the first solvent is a mixture of two or more solvents, the second solvent may not be provided. The first solvent is more preferably methyl acetate, acetone, methyl formate, ethyl formate or a mixture thereof, and the second solvent is preferably methyl ethyl ketone, cyclopentanone, cyclohexanone, or methyl acetyl acetate. It may be.

The alcohol as the third solvent is preferably linear, branched or cyclic, and among them, a saturated aliphatic hydrocarbon is preferred. The hydroxyl group of the alcohol may be any of primary to tertiary. Examples of alcohols include methanol, ethanol, 1-propanol, 2-propanol, 1-
Butanol, 2-butanol, t-butanol, 1-pentanol, 2-methyl-2-butanol and cyclohexanol. In addition, as the alcohol, a fluorinated alcohol is also used. For example, 2-fluoroethanol, 2,2,2-trifluoroethanol,
Also included are 2,2,3,3-tetrafluoro-1-propanol. Further, the hydrocarbon may be linear, branched or cyclic. Both aromatic hydrocarbons and aliphatic hydrocarbons can be used. Aliphatic hydrocarbons may be saturated or unsaturated.
Examples of the hydrocarbon include cyclohexane, hexane, benzene, toluene and xylene. These third
The alcohols and hydrocarbons as the solvents may be used alone or as a mixture of two or more, and are not particularly limited. Third
As the solvent, preferred specific compounds are methanol, ethanol, 1-propanol and alcohol.
2-propanol, 1-butanol, 2-butanol,
And cyclohexanol, cyclohexane, hexane, particularly methanol, ethanol,
1-propanol, 2-propanol and 1-butanol.

The above three kinds of mixed solvents are such that the first solvent is contained in a ratio of 20 to 90% by mass, the second solvent is contained in a ratio of 5 to 60% by mass, and the third solvent is contained in a ratio of 5 to 30% by mass. Is preferable, and the first solvent is 30 to 86% by mass,
Preferably, the second solvent contains 10 to 50% by mass and the third alcohol 7 to 25% by mass. Particularly, the first solvent is 30 to 80% by mass, and the second solvent is 1% by mass.
0 to 50% by mass, the third solvent is alcohol
Preferably, the content is 20% by mass. When the first solvent is a mixed solution and the second solvent is not used, the first solvent is preferably contained in a ratio of 20 to 90% by mass, and the third solvent is preferably contained in a ratio of 5 to 30% by mass, Furthermore, the first solvent is 30 to
86% by mass, and the third solvent is 7 to 25% by mass.
Preferably, it is included. Specific examples of preferred combinations of these solvents in the present invention include the following.

Methyl acetate / acetone / methanol / ethanol / butanol (75/10/5/5/5, parts by mass), methyl acetate / acetone / methanol / ethanol / propanol (75/10/5/5/5, parts by mass) Department),
Methyl acetate / acetone / methanol / ethanol / cyclohexane (75/10/5/5/5, parts by mass), methyl acetate / methyl ethyl ketone / methanol / ethanol (80/10/5/5, parts by mass), methyl acetate / acetone / Methyl ethyl ketone / ethanol (75/10/1)
0/5, parts by mass), methyl acetate / cyclopentanone / methanol / ethanol (80/10/5/5, parts by mass), methyl acetate / cyclopentanone / methanol / ethanol (80/10/5/5, Parts by mass), methyl acetate / cyclopentanone / acetone / methanol / ethanol (60/15/15/5/5, parts by mass), methyl acetate / cyclohexanone / methanol / hexane (70/2)
0/5/5, parts by mass), methyl acetate / methyl ethyl ketone / acetone / methanol / ethanol (50/20 /
20/5/5, parts by mass), methyl acetate / 1,3 dioxolane / methanol / ethanol (70/20/5/5,
Parts by mass), methyl acetate / dioxane / acetone / methanol / ethanol (60/20/10/5/5, parts by mass), methyl acetate / acetone / cyclopentanone / ethanol / butanol / cyclohexane (65/10/1)
0/5/5/5, parts by mass), methyl formate / methyl ethyl ketone / acetone / methanol / ethanol (50/2
0/20/5/5, parts by mass), methyl formate / acetone /
Ethyl acetate / ethanol / butanol / hexane (65
/ 10/10/5/5/5/5, parts by mass), acetone / methyl acetoacetate / methanol / ethanol (65/20 /
10/5, parts by mass), acetone / cyclopentanone / ethanol / butanol (65/20/10/5, parts by mass), acetone / 1,3 dioxolan / ethanol / butanol (65/20/10/5, parts by mass) Parts) 1,3 dioxolane / cyclohexanone / methyl ethyl ketone /
Methanol / butanol (55/20/10/5/5/5 /
5, parts by mass), acetone / methylene chloride / methanol (85/5/5, parts by mass), methyl acetate / methylene chloride / methanol / ethanol (70/10/15/5, parts by mass), 1,3-dioxolane / Methylene chloride / methanol / butanol (70/15/10/5, parts by mass),
1,4-dioxane / methylene chloride / acetone / methanol / butanol (70/5/15/5/5, parts by mass), cyclohexanone / methylene chloride / acetone / methanol / ethanol / propanol (60/10/1)
5/5/5/5, parts by mass), and the like,
Among these, methyl acetate / acetone / methanol / ethanol (75/15/5/5, parts by mass), methyl acetate / acetone / methanol / ethanol / butanol (75/10/5/5/5, parts by mass), Methyl acetate / cyclopentanone / methanol / ethanol (80/10
/ 5/5, parts by mass), acetone / methyl acetoacetate / ethanol / isopropanol (65/15/10/5 /
5, mass parts) is a preferred combination.

The dissolution method of the cellulose acylate solution (dope) is not particularly limited, and may be room temperature, may be a cooling dissolution method or a high temperature dissolution method, or a combination thereof. For example, JP-A-5-163
No. 301, JP-A-61-106628 and JP-A-58-106
127737, JP-A-9-95544, JP-A-10-95544
-95854, JP-A-10-45950, JP-A-20
00-53784, JP-A-11-322946, JP-A-11-322947, JP-A-2-276830
JP-A-2000-273239, JP-A-11-71
463, JP-A-04-259511, JP-A-2000
For example, JP-A-273184, JP-A-11-332017, and JP-A-11-302388 disclose methods for preparing a cellulose acylate solution. The above-described methods for dissolving cellulose acylate in an organic solvent can also be applied to the present invention within the scope of the present invention as appropriate. Hereinafter, the dissolution of the cellulose acylate in the non-chlorine-based organic solvent according to the present invention will be described in further detail.

In the case of dissolution at room temperature, cellulose acylate is mixed with a solvent or an additive at a temperature of 0 to 55 ° C., and the mixture is stirred and mixed in a dissolving pot or the like to dissolve. Regarding dissolution, it is important that the cellulose acylate powder is soaked sufficiently uniformly in the solvent, and it is essential not to generate so-called mamaco (cellulose acylate powder portion in which the solvent does not spread at all). Therefore, it may be preferable to add a solvent in advance to the stirring vessel and then reduce the pressure in the dissolution vessel to add the cellulose acylate. Conversely, in some cases, it is preferable to add cellulose acylate in advance to the stirring vessel, and then add the solvent while reducing the pressure in the dissolving vessel. It is also a preferable method for preparing a solution to wet cellulose acylate in advance with a poor solvent such as alcohol, and then add the ether, ketone or ester solvent having 3 to 12 carbon atoms of the present invention. When a plurality of solvents are used, the order of addition is not particularly limited. For example, after the cellulose acylate is added to the main solvent, another solvent (for example, a gelling solvent such as alcohol) may be added, or after the gelling solvent is wetted in advance by the cellulose acylate. May be added, which is effective in preventing heterogeneous dissolution. In addition, at the time of stirring, after mixing the cellulose acylate and the solvent, the mixture may be left as it is to allow the cellulose acylate to sufficiently swell with the solvent, and then may be stirred to obtain a uniform solvent.

The preparation of a cellulose acylate solution (dope) preferably used in the present invention is carried out according to a cooling dissolution method and will be described below. First, the temperature around room temperature (-10
(−55 ° C.), the cellulose acylate is gradually added to the organic solvent with stirring. When using multiple solvents,
The order of addition is not particularly limited. For example, after the cellulose acylate is added to the main solvent, another solvent (for example, a gelling solvent such as alcohol) may be added, or after the gelling solvent is wetted in advance by the cellulose acylate. May be added, which is effective in preventing heterogeneous dissolution. It is preferable to adjust the amount of cellulose acylate so that the mixture contains 5 to 40% by mass. More preferably, the amount of cellulose acylate is from 10 to 30% by mass. Further, an optional additive described below may be added to the mixture. Next, the mixture is heated to -100 to -10C (preferably -100 to -30).
° C, more preferably -100 to -50 ° C, most preferably -90 to -60 ° C). The cooling can be performed, for example, in a dry ice / methanol bath (−75 ° C.) or a mechanically cooled fluorine-based solvent (CFC). When cooled in this way, the mixture of the cellulose acylate and the organic solvent solidifies. The cooling rate is not particularly limited, but in the case of batch-type cooling, the viscosity of the cellulose acylate solution increases with cooling, and the cooling efficiency is inferior. is necessary.

Further, after the cellulose acylate solution is swollen, it can be achieved by transferring the cooling device at a predetermined cooling temperature for a short time. The cooling rate is preferably as high as possible, but the theoretical upper limit is 10,000 ° C./sec.
00 ° C / sec is the technical upper limit and 100 ° C
/ Sec is a practical upper limit. Note that the cooling rate is a value obtained by dividing the difference between the temperature at which cooling is started and the final cooling temperature by the time from when cooling is started to when the temperature reaches the final cooling temperature. Furthermore, this is 0-200 degreeC
(Preferably from 0 to 150 ° C., more preferably from 0 to 12
Heating to 0 ° C, most preferably 0 to 50 ° C) results in a solution in which the cellulose acylate flows in the organic solvent.
The temperature may be raised only at room temperature or heated in a warm bath. At this time, the pressure may be 0.3 to 30 MPa, but there is no particular problem. In that case, the heating is preferably performed in a short time as much as possible, preferably within 0.5 to 60 minutes, and particularly, heating for a short time of 0.5 to 2 minutes is recommended. If the dissolution is insufficient, the operation of cooling and heating may be repeated. Whether the dissolution is sufficient
The determination can be made only by visually observing the appearance of the solution. In the cooling dissolution method, it is desirable to use a closed container in order to avoid water contamination due to condensation during cooling. Further, in the cooling and heating operation, if the pressure is increased during cooling and the pressure is reduced during heating, the dissolution time can be shortened. In order to perform pressurization and decompression, it is desirable to use a pressure-resistant container. The above cooling and melting methods are described in detail in JP-A-9-95544, JP-A-10-95854, and JP-A-10-95854.

Next, a cellulose acylate solution (dope)
The high-temperature dissolution method which is preferably carried out in the preparation of is described below. First, cellulose acylate is gradually added to an organic solvent at a temperature around room temperature (−10 to 55 ° C.) with stirring. When a plurality of solvents are used, the order of addition is not particularly limited. For example, after the cellulose acylate is added to the main solvent, another solvent (for example, a gelling solvent such as alcohol) may be added, or after the gelling solvent is wetted in advance by the cellulose acylate. May be added, which is effective in preventing heterogeneous dissolution. It is preferable that the cellulose acylate solution is swelled in advance by adding cellulose acylate to a mixed organic solvent containing various solvents. In such a case, cellulose acylate may be gradually added to any of the solvents at −10 to 55 ° C. with stirring, or may be swollen in advance with a specific solvent and then added with another combined solvent. The mixture may be mixed to form a uniform swelling solution, and further the mixture may be swelled with two or more solvents, and then the remaining solvent may be added. Next, the organic solvent mixture is 0.2 MPa to 30 M
Heated to 60 to 240 ° C under pressure of Pa (preferably 80 to 220 ° C, more preferably 100 to 200 ° C,
Most preferably 100-190 ° C). The heating may be, for example, high pressure steam or an electric heat source. For high pressure, a pressure vessel or pressure line is required, but any of iron or stainless steel or other metal pressure vessel or line may be used, and there is no particular limitation. Further, carbon dioxide may be sealed in these high-temperature and high-pressure solutions to form a so-called supercritical solution.
In that case, the ratio of carbon dioxide to solvent is 5/95 to 70
/ 30 is preferable, and 10/90 to 60/40 is more preferable.

Next, since these heated solutions cannot be applied as they are, they need to be cooled to a temperature lower than the lowest boiling point of the solvent used. In that case, it is common to cool to −10 to 55 ° C. and return to normal pressure. For cooling, the high-pressure high-temperature container or line containing the cellulose acylate solution may be simply left at room temperature, and more preferably, the device may be cooled using a coolant such as cooling water. In addition,
The heating and cooling operations may be repeated to speed up the dissolution. Whether or not the dissolution is sufficient can be determined only by visually observing the appearance of the solution. In the high-pressure high-temperature dissolution method, a closed container is used to avoid evaporation of the solvent. Further, in the swelling step, the dissolution time can be further reduced by increasing the pressure or reducing the pressure. In order to perform pressurization and decompression, a pressure-resistant container or line is essential. These are described in JP-A-11-32.
Details are described in JP-A Nos. 2946 and 11-322947.

The amount of cellulose acylate is preferably adjusted to be 5 to 40% by mass in the solution, and more preferably 10 to 30% by mass. In the present invention, as described above, the concentration of the cellulose acylate solution is characterized by a high concentration,
A cellulose acylate solution having a high concentration and excellent stability can be obtained without depending on the means of concentration. After further dissolving at a low concentration to facilitate dissolution, the solution may be concentrated using a concentration means. As a method of concentration, for example, while guiding the low-concentration solution between the cylindrical body and the rotation trajectory of the outer periphery of the rotating blades that rotate in the circumferential direction inside, the solvent is evaporated by giving a temperature difference between the solution and the solution. (See JP-A-4-259511), a heated low-concentration solution is blown into a container from a nozzle, and the solvent is flash-evaporated until the solution hits the inner wall of the container from the nozzle. A method of extracting vapor from a container and extracting a highly concentrated solution from the container bottom (US Pat. No. 254101)
No. 2, 2858229, 4414341, 4
504355).

Prior to casting, it is preferable that foreign substances such as undissolved matter, dust, and impurities are removed by filtration using a suitable filtering material such as a wire mesh or flannel. Absolute filtration accuracy of 0.1 to 100 μm for filtration of cellulose acylate solution
Filter is used, and the absolute filtration accuracy is 0.5
It is preferable to use a filter having a size of ２５25 μm.
The thickness of the filter is preferably from 0.1 to 10 mm, more preferably from 0.2 to 2 mm. In that case, filtration pressure is 16 kgf / cm ² or less, more preferably 12 kgf / cm ² or less, more 10 kgf / c
It is preferable to filter at m ² or less, particularly preferably at 2 kgf / cm ² or less. As the filter material, conventionally known materials such as glass fiber, cellulose fiber, filter paper, and fluororesin such as tetrafluoroethylene resin can be preferably used, and ceramics and metals are particularly preferably used.
The viscosity of the cellulose acylate solution immediately before film formation may be in a range that can be cast at the time of film formation, and is usually 10 Pa · s or more.
It is preferably prepared in the range of 2000 Pa · s,
30 Pa · s to 1000 Pa · s is more preferable, and
Pa · s to 500 Pa · s is more preferable. The temperature at this time is not particularly limited as long as it is the temperature at the time of casting, but is preferably −5 to 70 ° C., and more preferably −
5-55 ° C.

Next, a method for producing a film using a cellulose acylate solution will be described. In the production of the cellulose acylate film of the present invention, a solution casting film forming method and a solution casting film forming apparatus conventionally used for producing a cellulose triacetate film can be used. The dope (cellulose acylate solution) prepared from the dissolver (pot) is once stored in a storage pot, and the foam contained in the dope is defoamed for final preparation. Dope from dope outlet
For example, a dope is sent to a pressurized die through a pressurized fixed-quantity gear pump that can perform high-precision fixed-quantity liquid feeding according to the number of revolutions, and the dope is uniformly distributed on a metal support of a casting part running endlessly from a die (slit) of the pressurized die. At the peeling point where the metal support has made one round, the freshly dried dope film (also called a web) is peeled from the metal support. Both ends of the obtained web are sandwiched by clips, transported by a tenter while maintaining the width, and dried. Subsequently, the web is transported by a group of rolls of a drying device, dried, and wound up to a predetermined length by a winder. The combination of the tenter and the roll group drying device varies depending on the purpose. In a solution casting film forming method used for a silver halide photographic material or a functional protective film for an electronic display, in addition to a solution casting film forming apparatus, an undercoat layer, an antistatic layer, an antihalation layer, a protective layer, etc. In order to process the surface of the film, a coating device is often added. The following briefly describes each of the manufacturing steps, but is not limited thereto.

First, when the cellulose acylate solution (dope) thus prepared is formed into a cellulose acylate film by a solvent casting method, the dope is cast on a drum or a band, and the solvent is evaporated to form a film. I do. The concentration of the dope before casting is preferably adjusted so that the solid content is 5 to 40% by mass. It is preferable that the surface of the drum or the band is finished in a mirror state. The dope is preferably cast on a drum or band having a surface temperature of 30 ° C. or lower, and particularly preferably a metal support temperature of −10 to 20 ° C. Further, JP-A-2000-301555 and JP-A-200
0-301558, JP-A-7-032391, JP-A-03-193316, JP-A-05-086212
JP-A-62-037131, JP-A-02-276
607, JP-A-55-014201, JP-A-02-201
The techniques described in JP-A-111511 and JP-A-02-208650 can be applied to the present invention.

In the present invention, the obtained cellulose acylate solution may be cast as a monolayer solution on a smooth band or a drum as a metal support, or a cellulose acylate solution having two or more layers may be cast. May be cast. When casting a plurality of cellulose acylate solutions, a film is produced while casting and laminating a solution containing cellulose acylate from a plurality of casting ports provided at intervals in the traveling direction of the metal support, and laminating them. For example, Japanese Patent Application Laid-Open
Methods described in JP-A-158414, JP-A-1-122419, and JP-A-11-198285 can be applied. Alternatively, the film may be formed by casting a cellulose acylate solution from two casting ports, for example, JP-B-60-27562, JP-A-61-94724, JP-A-61-947245, JP-A-61-104813, JP-A-61-158413
And JP-A-6-134933. Also, a cellulose acylate film described in JP-A-56-162617, in which a flow of a high-viscosity cellulose acylate solution is wrapped with a low-viscosity cellulose acylate solution and the high- and low-viscosity cellulose acylate solutions are simultaneously extruded. A casting method may be used. Furthermore, Japanese Patent Application Laid-Open Nos. 61-94724 and 61-94.
It is also a preferred embodiment that the outer solution described in each publication of No. 725 contains more alcohol component which is a poor solvent than the inner solution. Alternatively, by using two casting ports, peeling the film formed on the metal support by the first casting port, and performing the second casting on the side in contact with the metal support surface, It may be to make a film,
For example, a method described in Japanese Patent Publication No. 44-20235. The cellulose acylate solutions to be cast may be the same solution or different cellulose acylate solutions, and are not particularly limited. In order to give a function to a plurality of cellulose acylate layers, a cellulose acylate solution corresponding to the function may be extruded from each casting port. Further, the cellulose acylate solution of the present invention can be simultaneously cast with other functional layers (for example, an adhesive layer, a dye layer, an antistatic layer, an antihalation layer, a UV absorption layer, a polarizing layer, etc.). .

In the conventional monolayer liquid, it is necessary to extrude a high-concentration and high-viscosity cellulose acylate solution in order to obtain a required film thickness. In this case, the stability of the cellulose acylate solution is poor. In many cases, solids were generated, resulting in troubles such as bumps and poor flatness. As a solution to this, by casting a plurality of cellulose acylate solutions from a casting port, a high-viscosity solution can be simultaneously extruded onto a metal support, and the planarity is improved and an excellent planar film is obtained. Not only can it be produced, but also by using a concentrated cellulose acylate solution, a reduction in the drying load can be achieved, and the production speed of the film can be increased.

In the case of co-casting, the thickness of the inner side and the outer side is not particularly limited. is there. Here, in the case of co-casting of three or more layers, the total thickness of the layer in contact with the metal support and the layer in contact with the air side is defined as the outer thickness. In the case of co-casting, a cellulose acylate film having a laminated structure can be produced by co-casting cellulose acylate solutions having different concentrations of additives such as the above-mentioned plasticizer, ultraviolet absorber and matting agent. For example, a cellulose acylate film having a structure of skin layer / core layer / skin layer can be produced. For example, the matting agent can be contained in a large amount in the skin layer or only in the skin layer. The plasticizer and the ultraviolet absorber can be added to the core layer more than the skin layer, or may be added only to the core layer.
The type of the plasticizer and the ultraviolet absorber can be changed between the core layer and the skin layer. For example, the skin layer contains a low-volatility plasticizer and / or an ultraviolet absorber, and the core layer has excellent plasticity. It is also possible to add a plasticizer or an ultraviolet absorber excellent in ultraviolet absorption. In a preferred embodiment, the release agent is contained only in the skin layer on the metal support side. Further, in order to cool the metal support by the cooling drum method to gel the solution, it is also preferable to add more alcohol, which is a poor solvent, to the skin layer than to the core layer. The Tg of the skin layer and the Tg of the core layer may be different, and the Tg of the skin layer may be different.
It is preferred that the Tg of the core layer be lower. Further, the viscosity of the solution containing cellulose acylate at the time of casting may be different between the skin layer and the core layer, and the viscosity of the skin layer is preferably smaller than the viscosity of the core layer. May be smaller than the viscosity.

More specifically, the casting method useful in the present invention is described in detail. A method in which the prepared dope is uniformly extruded from a pressure die onto a metal support, and a method in which the dope once cast on the metal support is bladed. A method using a doctor blade or a method using a reverse roll coater to adjust the film thickness with a counter-rotating roll is preferred, but a method using a pressure die is preferable. The pressure die includes a coat hanger type and a T-die type, and any of them can be preferably used. In addition, it can be carried out by various methods for casting and forming a cellulose triacetate solution conventionally known in addition to the methods mentioned here, and by setting each condition in consideration of a difference in the boiling point of the solvent used, etc. The same effects as those described in the above publication can be obtained. As a metal support running endlessly used for producing the cellulose acylate film of the present invention, a drum whose surface is mirror-finished by chrome plating or a stainless belt (surface called a band) which is mirror-finished by surface polishing is used. Is also used. One or more pressure dies may be provided above the metal support for the production of the cellulose acylate film of the present invention. Preferably it is one or two. When two or more units are installed, the dope amount to be cast may be divided into various ratios for each die.
The dope may be sent to the die at a respective ratio from a plurality of precision metering gear pumps. The temperature of the cellulose acylate solution used for casting is preferably from -10 to 55C, more preferably from 25 to 50C. In that case, all of the steps may be the same, or may be different at various points in the steps. If different, the temperature may be a desired temperature immediately before casting.

The drying of the dope on the metal support in the production of the cellulose acylate film of the present invention is generally carried out by drying the dope on the surface side of the metal support (drum or belt).
In other words, a method of applying hot air from the surface of the web on the metal support, a method of applying hot air from the back of the drum or belt, and contacting a temperature-controlled liquid from the back of the belt or drum opposite the dope casting surface. There is a liquid heat transfer method in which the surface temperature is controlled by heating the drum or belt by heat transfer, and a back liquid heat transfer method is preferable. The surface temperature of the metal support before casting may be any number of times as long as it is lower than the boiling point of the solvent used for the dope. However, in order to promote drying and to lose the fluidity on the metal support, the temperature should be set to 1 to 10 ° C. lower than the boiling point of the solvent having the lowest boiling point among the solvents used. Is preferred. This is not the case when the casting dope is cooled and peeled off without drying.

Further, there is a method of positively stretching in the width direction. For example, JP-A-62-115035,
JP-A-152125, JP-A-4-284221, JP-A-4-298310, and JP-A-11-48271. In order to increase the in-plane retardation value of the cellulose acylate film, the produced film is stretched. The stretching of the film is performed at normal temperature or under heating conditions. The heating temperature is preferably equal to or lower than the glass transition temperature of the film. The stretching of the film may be uniaxial stretching or biaxial stretching. The stretching is preferably from 1 to 200%, particularly preferably from 1 to 100%. The thickness of the finished (after drying) cellulose acylate film of the present invention is:
Although it depends on the purpose of use, it is usually in the range of 5 to 500 μm, preferably in the range of 20 to 300 μm, and most preferably in the range of 30 to 150 μm. The film thickness may be adjusted by adjusting the concentration of the solid content contained in the dope, the slit gap of the die, the extrusion pressure from the die, the speed of the metal support, and the like so as to obtain the desired thickness.

The width of the cellulose acylate film obtained as described above is preferably 0.5 to 3 m, more preferably 0.6 to 2.5 m, and still more preferably 0.8 to 3 m.
~ 2.2 m. Length is 100 to 10 per roll
Preferably, it is wound at 000 m, more preferably 50 m
0 to 7000 m, more preferably 1000 to 6
000 m. When winding, it is preferable to impart knurling to at least one end, the width is 3mm ~ 50mm,
More preferably, the height is 5 to 30 mm, and the height is 0.5 to 500.
μm, and more preferably 1 to 200 μm. This may be a single push or a double push.

The cellulose acylate film can be optionally subjected to a surface treatment to improve the adhesion between the cellulose acylate film and each functional layer (for example, an undercoat layer and a back layer). For example, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment can be used. The glow discharge treatment referred to here is so-called low-temperature plasma generated under a low-pressure gas of 10-3 to 20 Torr. Furthermore, plasma treatment under atmospheric pressure is also preferable.
The plasma treatment used for the surface treatment of the cellulose acylate film of the invention will be described. In particular,
There are methods using vacuum glow discharge, atmospheric pressure glow discharge, and the like. Other methods include a method such as flame plasma processing. These are described, for example, in JP-A-6-12306.
No. 2, JP-A-11-293011 and 11-5
The method described in each publication of 857 can be used. Above all, those based on atmospheric pressure glow discharge are preferably used. The plasma-excitable gas refers to a gas that is plasma-excited under the above-mentioned conditions, such as argon, helium, neon, krypton, xenon, nitrogen, carbon dioxide, fluorocarbons such as tetrafluoromethane, and mixtures thereof. Can be As these gases, those obtained by adding a reactive gas capable of imparting a polar functional group such as a carboxyl group, a hydroxyl group, or a carbonyl group to the surface of a plastic film to an inert gas such as argon or neon are used as an excitable gas. . As the reactive gas, in addition to hydrogen, oxygen, and nitrogen, in addition to gases such as steam and ammonia, low-boiling organic compounds such as lower hydrocarbons and ketones can be used as necessary. ,oxygen,
Gases such as carbon dioxide, nitrogen and water vapor are preferred. In the case of using steam, a gas obtained by bubbling another gas through water can be used. Alternatively, steam may be mixed.

Next, an ultraviolet irradiation method is also preferably used in the present invention, and Japanese Patent Publication No. 43-2603 and
No. 4, and JP-B No. 45-3828. The mercury lamp is a high-pressure mercury lamp composed of a quartz tube, and has a wavelength of ultraviolet light of 180 to 38.
Those between 0 nm are preferred. With respect to the method of irradiating ultraviolet rays, a high-pressure mercury lamp having a main wavelength of 365 nm can be used as the light source if there is no problem in the performance of the support that the surface temperature of the cellulose acylate film rises to around 150 ° C. When low-temperature processing is required, a low-pressure mercury lamp having a main wavelength of 254 nm is preferable. It is also possible to use an ozoneless type high-pressure mercury lamp and a low-pressure mercury lamp. Regarding the amount of processing light, as the amount of processing light increases, the adhesive strength between the cellulose acylate film and the layer to be bonded improves, but the film becomes colored and becomes brittle as the amount of light increases. Therefore, with a high-pressure mercury lamp having a main wavelength of 365 nm, the irradiation light amount is preferably ^{20 to} 10000 (mJ / cm ² ), more preferably 50 to 2000 (mJ / cm ² ). 2
When the low-pressure mercury lamp whose main wavelength is 54 nm, the irradiation light quantity 100~10000 (mJ / cm ²⁾ C., more preferably 300~1500 (mJ / cm ^2).

Next, corona discharge treatment is also preferably used as a surface treatment of the cellulose acylate film. Japanese Patent Publication Nos. 42114
Can be performed by the processing method described in each of the publications. Corona discharge treatment equipment is a solid state corona treatment machine manufactured by Pillar, a LEPEL type surface treatment machine, VE
A TAPHON type processor or the like can be used. The treatment can be performed at normal pressure in air. Describing the flame treatment, the gas used may be any of natural gas, liquefied propane gas and city gas, but the mixing ratio with air is important. This is because the effect of the surface treatment by the flame treatment is considered to be brought about by the plasma containing active oxygen. is there. These two factors are determined by the gas / oxygen ratio. When the reaction is performed without excess or deficiency, the energy density becomes highest and the plasma activity becomes high. Specifically, a preferable mixing ratio of natural gas / air is 1/6 to 1/1 in volume ratio.
10, preferably 1/7 to 1/9. In the case of liquefied propane gas / air, 1/14 to 1/22, preferably 1/16 to 1/19, and in the case of city gas / air, 1/14 to 1/29.
It is 2 to 1/8, preferably 1/3 to 1/7. Also,
The flame treatment amount is preferably in the range of 1 to 50 Kcal / m ² , more preferably 3 to 20 Kcal / m ² .

The alkali saponification treatment preferably used as a surface treatment for a cellulose acylate film will be specifically described. The alkali saponification treatment is preferably performed in a cycle in which the surface of the cellulose acylate film is immersed in an alkaline solution, neutralized with an acidic solution, washed with water and dried. Examples of the alkaline solution include a potassium hydroxide solution and a sodium hydroxide solution, and the specified concentration of hydroxide ions is preferably 0.1 N to 3.0 N, and more preferably 0.5 N to 2.0 N. Is more preferred. The temperature of the alkali solution is preferably in the range of room temperature to 90 ° C, more preferably 40 ° C to 70 ° C. Next, it is generally washed with water, and then after passing through an acidic aqueous solution,
A cellulose acylate film having been subjected to surface treatment by washing with water is obtained. At this time, examples of the acid used for the acidic aqueous solution include hydrochloric acid, nitric acid, sulfuric acid, acetic acid, formic acid, chloroacetic acid, and oxalic acid. The concentration of the acidic aqueous solution is from 0.01 N
3.0N, preferably 0.05N to 2.0N
Is more preferable. When the cellulose acylate film of the invention is used as a transparent protective film for a polarizing plate, it is particularly preferable to perform an acid treatment or an alkali treatment, that is, a saponification treatment on the cellulose acylate, from the viewpoint of adhesion to the polarizing film. . These solutions may be water alone, or may be a mixture of water-soluble organic solvents (methanol, ethanol, isopropanol, acetone, etc.).

In order to achieve the adhesion between the film and the functional layer, a method of applying a functional layer directly on a cellulose acylate film after performing a surface activation treatment to obtain an adhesive force, There is a method in which an undercoat layer (adhesive layer) is provided after treatment or without surface treatment, and a functional layer is applied thereon. Various contrivances have been made for the constitution of the undercoat layer, and a layer (hereinafter abbreviated as the first undercoat layer) which is well adjacent to the support is provided as a first layer, and a functional layer is formed as a second layer thereon. There is a so-called multi-layer method in which an undercoating second layer that adheres well is applied. In the single-layer method, good adhesion is often achieved by expanding the cellulose acylate film and mixing it with the undercoat material.
Examples of the undercoat polymer used in the present invention include a water-soluble polymer, a cellulose acylate, a latex polymer, and a water-soluble polyester. As a polymer,
Gelatin, gelatin derivatives, casein, agar, sodium alginate, starch, polyvinyl alcohol, polyacrylic acid copolymer, maleic anhydride copolymer, and the like. Examples of cellulose acylate include carboxymethyl cellulose and hydroxyethyl cellulose.

The cellulose acylate film of the invention is applied to optical uses and photographic materials as its uses. In particular, it is preferable that the optical application is a liquid crystal display device, and the liquid crystal display device has a liquid crystal cell carrying liquid crystal between two electrode substrates, two polarizing elements disposed on both sides of the liquid crystal cell, and the liquid crystal. It is more preferable that at least one optical compensation sheet is disposed between the cell and the polarizing element. These liquid crystal display devices include TN, I
PS, FLC, AFLC, OCB, STN, VA, and HAN are preferable, and details will be described later. At that time, when the cellulose acylate film produced using the non-chlorine organic solvent of the present invention is used for the above-mentioned optical application, various functional layers are provided. They include, for example, an antistatic layer, a cured resin layer (a transparent hard coat layer),
Anti-reflection layer, easy adhesion layer, anti-glare layer, optical compensation layer, alignment layer,
For example, a liquid crystal layer. Examples of these functional layers and their materials of the present invention include surfactants, slip agents, matting agents, antistatic layers, hard coat layers, and the like.

First, a surfactant is used depending on the purpose of use.
Although classified into a dispersant, a coating agent, a wetting agent, an antistatic agent, and the like, these objects can be achieved by appropriately using a surfactant described below. Surfactants are nonionic,
Any of ionic (anion, cation, betaine) can be used. Further, a fluorine-based surfactant is also preferably used as a coating agent in an organic solvent or as an antistatic agent. The layer used may be a cellulose acylate solution or any of the other functional layers. When used in optical applications, examples of functional layers include undercoat layers, intermediate layers,
Orientation control layer, refractive index control layer, protective layer, antifouling layer, adhesive layer,
Examples include a back undercoat layer and a back layer. The amount used is not particularly limited as long as it is an amount necessary for achieving the purpose, but generally, the amount used is 0.1 to the mass of the layer to be added.
It is preferably 0001 to 5% by mass, and more preferably 0.1 to 5% by mass.
It is preferably from 0005 to 2% by mass. In that case, the coating amount is preferably 0.02 to 1000 mg, more preferably 0.05 to 200 mg per 1 m ² . Preferred nonionic surfactants include
Polyoxyethylene, polyoxypropylene, polyoxybutylene, a surfactant having a nonionic hydrophilic group of polyglycidyl and sorbitan, specifically, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxy Ethylene-polyoxypropylene glycol, polyhydric alcohol fatty acid partial ester, polyoxyethylene polyhydric alcohol fatty acid partial ester, polyoxyethylene fatty acid ester,
Examples include polyglycerin fatty acid esters, fatty acid diethanolamides, and triethanolamine fatty acid partial esters.

Examples of the anionic surfactant include carboxylate, sulfate, sulfonate and phosphate ester, and typical examples are fatty acid salt, alkylbenzene sulfonate and alkylnaphthalene sulfonate. Salt, alkyl sulfonate, α-olefin sulfonate, dialkyl sulfosuccinate, α-sulfonated fatty acid salt, N-methyl-N-oleyltaurine, petroleum sulfonate, alkyl sulfate, sulfated oil, polyoxy Examples include ethylene alkyl ether sulfate, polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene styrenated phenyl ether sulfate, alkyl phosphate, polyoxyethylene alkyl ether phosphate, and naphthalene sulfonate formaldehyde condensate. . Examples of the cationic surfactant include an amine salt, a quaternary ammonium salt, a pyridum salt and the like, and primary to tertiary fatty amine salts, quaternary ammonium salts (tetraalkylammonium salt, trialkylbenzylammonium) Salts, alkylpyridium salts, alkylimidazolium salts, etc.). Examples of amphoteric surfactants include carboxybetaine, sulfobetaine and the like, and N-trialkyl-N-carboxymethylammonium betaine, N
-Trialkyl-N-sulfoalkylene ammonium betaine and the like. These surfactants are described in Applications of Surfactants (Koshobo, Takao Karimei, published September 1, 1980). In the present invention, a preferred surfactant is not particularly limited in its use amount, and any surfactant may be used as long as desired surfactant properties can be obtained. Specific examples of the surfactant are described below, but are not limited thereto (here, -C ₆ H _4- represents a phenylene group).

Further, a slipping agent may be contained in any of the layers above the cellulose acylate film, and in that case, the outermost layer is particularly preferred. As the slip agent used,
For example, polyorganosiloxanes disclosed in JP-B-53-292, U.S. Pat. No. 4,275,
No. 146, higher fatty acid amides as disclosed in JP-B-58-33541, UK Patent No. 92
No. 7,446, or JP-A-55-126238 and JP-A-58-90633, which are examples of a higher fatty acid ester (containing a fatty acid having 10 to 24 carbon atoms and an alcohol having 10 to 24 carbon atoms). Ester), and
Metal salts of higher fatty acids as disclosed in U.S. Pat. No. 3,933,516, and JP-A-58-505.
No. 34, an ester of a linear higher fatty acid and a linear higher alcohol, disclosed in WO 901081
Higher fatty acid-higher alcohol esters containing a branched alkyl group as disclosed in 15.8 are known. Among these, polyorganosiloxanes include polyalkylsiloxanes such as polydimethylsiloxane and polydiethylsiloxane, polyarylsiloxanes such as polydiphenylsiloxane and polymethylphenylsiloxane, and generally known polyorganosiloxanes. issue,
JP-B-55-49294 and JP-A-60-140
No. 341, an organopolysiloxane having an alkyl group of C5 or more, an alkylpolysiloxane having a polyoxyalkylene group in a side chain, alkoxy, hydroxy, hydrogen, carboxyl, amino, mercapto in a side chain. It is also possible to use a modified polysiloxane such as an organopolysiloxane having a group,
A block copolymer having a siloxane unit can be used. Specific examples of such compounds are shown below, but are not limited thereto. Further, as higher fatty acids and derivatives thereof, higher alcohols and derivatives thereof, higher fatty acids, metal salts of higher fatty acids,
Higher fatty acid esters, higher fatty acid amides, polyhydric alcohol esters of higher fatty acids, etc .; higher fatty alcohols; Fate, trialkyl phosphate, higher aliphatic alkyl sulfonic acid, an amide compound thereof or a salt thereof can be used. Specific examples of such compounds are shown below, but the present invention is not limited thereto.

By using such a slipping agent, it is possible to obtain an excellent film having excellent scratch strength and free from repelling or the like on the undercoat surface. The amount of the slip agent used is not particularly limited, but the content is 0.0005 to 2 g /
m ² , more preferably 0.001 to
1 g / m ² , particularly preferably 0.002 to 0.5 g / m ²
It is. The layer to which the slip agent is added is not particularly limited, but is preferably contained in the outermost layer on the back surface. The surface layer containing the above-mentioned slipping agent can be formed by applying a coating solution obtained by dissolving the same in an appropriate organic solvent onto a support or a support having a back layer provided with another layer, and drying. Further, the slip agent can be added in the form of a dispersion in the coating solution. The slip performance is preferably a static friction coefficient of 0.30 or less, more preferably 0.25 or less, and particularly preferably 0.13 or less. Further, it is preferable that the coefficient of static friction with the contacting material is small, which is also useful for preventing scratches and the like. The coefficient of static friction with the mating material at that time is also preferably 0.3 or less, more preferably 0.25 or less, and particularly preferably 0.13 or less. In many cases, it is preferable to reduce the coefficient of static friction between the front and back of the film or the optical film. Further, the dynamic friction coefficient is preferably 0.30 or less, and more preferably 0.3.
It is preferably 25 or less, particularly preferably 0.15 or less. Further, the coefficient of kinetic friction with the mating material to be contacted is preferably 0.3 or less,
Further, it is preferably 0.25 or less, particularly preferably 0.15 or less.
In many cases, it is preferable to reduce the dynamic friction coefficient of the front and back of the film or the optical film. The dynamic friction coefficient between them is preferably 0.30 or less, more preferably 0.25 or less.
In particular, 0.13 or less is preferable.

In the functional layer of the cellulose acylate film of the present invention, it is preferable to use a matting agent in order to improve the slipperiness of the film and the adhesion resistance under high humidity. In that case, the average height of the protrusions on the surface is 0.005 to
10 μm is preferable, and more preferably 0.01 to 5 μm
It is. The better the number of the projections on the surface, the better. A preferable protrusion is in a range having an average height of the protrusion, for example, when the protrusion is formed with a spherical or irregular matting agent, the content is 0.5 to 600 mg / m ² , and more preferable. Is 1 to 400 mg / m ² . At this time, as the matting agent to be used, fine particles added to the cellulose acylate film described above can be used, and the composition thereof is not particularly limited, and may be an inorganic or organic substance, or a mixture of two or more kinds. Inorganic compounds and organic compounds of the matting agent include, for example, barium sulfate, manganese colloid, titanium dioxide, strontium barium sulfate, silicon dioxide,
There are fine powders of inorganic substances such as aluminum oxide, tin oxide, zinc oxide, calcium carbonate, barium sulfate, talc, kaolin, and calcium sulfate. And titanium dioxide (rutile type or anatase type) generated by titanium slug and sulfuric acid. It can also be obtained by pulverizing an inorganic substance having a relatively large particle size, for example, 20 μm or more, and then performing classification (vibration filtration, air classification, etc.). In addition, polytetrafluoroethylene, cellulose acetate, polystyrene, polymethyl methacrylate, polypropylene methacrylate, polymethyl acrylate, polyethylene carbonate, acrylic styrene resin, silicone resin, polycarbonate resin, benzoguanamine resin, melamine resin, polyolefin powder Also, pulverized and classified organic polymer compounds such as polyester-based resins, polyamide-based resins, polyimide-based resins, polyfluoroethylene-based resins, and starch can be used. Alternatively, a polymer compound synthesized by a suspension polymerization method, a polymer compound formed into a spherical shape by a spray drying method or a dispersion method, or an inorganic compound can be used.

The polarizing plate used as the optical film or the polarizing plate protective film of the present invention can be subjected to antistatic processing, transparent hard coat processing, antiglare processing, antireflection processing, easy adhesion processing and the like. Alternatively, an optical compensation function can be provided by forming an alignment film and providing a liquid crystal layer. These details can be applied to the technology described in JP-A-2000-352620, and are described below. What is antistatic processing?
When the resin film is handled, the resin film is provided with a function of preventing the resin film from being charged. Specifically, this is performed by providing a layer containing an ion conductive substance or conductive fine particles. Here, the ionic conductive substance refers to a substance that exhibits electric conductivity and contains ions that are carriers that carry electricity, and examples thereof include ionic polymer compounds. Of these, preferred are those in which the conductive substance is in the form of fine particles, which are finely dispersed and added to the above-mentioned resin, and preferable conductive substances used in these are metal oxides and these. It is desirable to contain conductive fine particles composed of a composite oxide of the above and ionicene conductive polymers or quaternary ammonium cation conductive polymer particles having an intermolecular crosslink as described in JP-A-9-203810. . The preferred particle size is in the range of 5 nm to 10 μm, and the more preferred range depends on the type of fine particles used.

Examples of metal oxides that are conductive fine particles
Are ZnO, TiO_Two, SnO_Two, Al_TwoO_Three, In_TwoO_Three,
SiO_Two, MgO, BaO, MoO_Two , V_TwoO_FiveEtc.
Are preferably these composite oxides, particularly ZnO, TiO
_TwoAnd SnO_TwoIs preferred. Examples including heteroatoms include
For example, for ZnO, addition of Al, In, etc., TiO _Two
For Nb, Ta, etc., and SnO_TwoAgainst
Is effective to add Sb, Nb, halogen element, etc.
You. The addition amount of these different atoms is 0.01 to 25 mol%
Is preferably in the range of 0.1 to 15 mol%.
Preferred. Furthermore, organic electronically conductive organic compounds are also useful.
Can be used. For example, polythiophene, polypyrrole,
Lianiline, polyacetylene, polyphosphazene, etc.
It is. These are polystyrene sulfonates as acid donors.
Preferred for use in complexes with phosphoric acid, perchloric acid, etc.
Can be.

The optical film of the present invention can be provided with a transparent hard coat layer. Active ray curable resin or thermosetting resin is preferably used as the transparent hard coat layer. The actinic ray-curable resin layer refers to a layer mainly composed of a resin which is cured through a crosslinking reaction or the like by irradiation with actinic rays such as ultraviolet rays or electron beams. Typical examples of the actinic ray-curable resin include an ultraviolet ray curable resin and an electron beam curable resin. Examples of the ultraviolet-curable resin include an ultraviolet-curable acrylic urethane-based resin, an ultraviolet-curable polyester acrylate-based resin, an ultraviolet-curable epoxy acrylate-based resin, an ultraviolet-curable polyol acrylate-based resin, and an ultraviolet-curable epoxy resin. be able to. UV-curable acrylic urethane-based resins are generally obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer, and further adding 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter acrylate includes methacrylate). Can be easily obtained by reacting an acrylate monomer having a hydroxyl group such as 2-hydroxypropyl acrylate, etc., and described in, for example, JP-A-59-151110.

The optical film of the present invention may be provided with an antireflection layer. Various types of antireflection layers are known, such as a single layer and a multilayer. However, a multilayer having a structure in which high-refractive-index layers and low-refractive-index layers are alternately laminated is generally used. Examples of the configuration include a layer composed of two layers of a high refractive index layer / a low refractive index layer in order from the transparent substrate side, or a layer having a different refractive index, and a medium refractive index layer (a transparent substrate or a hard substrate). A layer having a higher refractive index than the coating layer and a lower refractive index than the high refractive index layer) / a layer having a high refractive index / a layer having a low refractive index; Some suggestions have been made. Above all, from the viewpoint of durability, optical properties, cost, productivity, and the like, it is preferable to apply a high-refractive-index layer / a medium-refractive-index layer / a low-refractive-index layer on a substrate having a hard coat layer in this order. A high-refractive-index layer (sometimes provided with a medium-refractive-index layer) and a low-refractive-index layer facing the air are sequentially laminated on the substrate surface. On the other hand, an optical interference layer formed by setting it to a certain value to form an antireflection laminate is particularly preferable as the antireflection layer, and the refractive index and the film thickness can be calculated from the measurement of spectral reflectance. The optical film of the present invention may be subjected to a curl prevention process. Anti-curl processing is to give the function of trying to curl with the surface on which it is applied inside, but by performing this processing, one surface of the transparent resin film is processed in some way, and When a surface treatment of a different degree and type is performed, it functions to prevent the surface from being curled with its surface inside. The anti-curl layer is provided on the side opposite to the side having the anti-glare layer or the anti-reflection layer of the substrate, or for example, an easy-adhesion layer may be applied on one side of a transparent resin film, Is applied.

The physical properties of the cellulose acylate film produced by the above method will be described in more detail. When the optical film of the present invention is a polarizing plate protective film, the protective film preferably has a thickness in the range of 5 to 500 μm. The thickness of the protective film is 20 to
More preferably, it is in the range of 300 μm,
Most preferably, it is in the range of 150 μm. In the present invention, the in-plane retardation Re of the cellulose acylate film formed as described above is obtained.
Is particularly preferably less than 500 nm,
It is more preferably less than 200 nm, further preferably less than 200 nm, still more preferably 100 nm or less, further preferably 50 nm or less, and even more preferably 30 nm or less. It is particularly preferably 10 nm or less, and more preferably 5 nm. Further, Rth of the cellulose acylate film of the present invention is 0 nm to 600 per 100 μm.
nm, and further used from 0 nm to 400 nm. In particular, it is preferable to use it at 0 nm to 250 nm.
The angle θ (here, θ) between the film forming direction (corresponding to the longitudinal direction) of the optical film of the present invention and the slow axis of the film.
It is more preferable that 1) is closer to 0 °, + 90 ° or −90 °. Here, θ1 is a narrow angle formed between the film forming direction and the slow axis, and is in a range of + 90 ° to −90 °. Particularly when used as a protective film for a polarizing plate, it contributes to an improvement in the degree of polarization of the obtained polarizing plate. Here, the slow axis is the direction in which the refractive index in the film plane is highest.

In the present invention, the cellulose acylate film formed as described above preferably has a vertical and horizontal dimensional shrinkage of ± 0.1% or less at 105 ° C. for 5 hours. . Further, the haze of the cellulose acylate film in terms of 80 μm is preferably 0.6% or less, particularly preferably 0.5% or less, more preferably 0.1% or less. still,
The lower limit of the haze value is not particularly limited. Further, the tear strength of the optical film of the present invention is preferably 10 g or more, more preferably 12 g or more,
The weight is more preferably 15 g or more, more preferably 18 g or more, further preferably 20 g or more, and even more preferably 22 g or more. The tensile strength of the cellulose acylate film is 50 N / m.
m ² or more, and the elastic modulus is 3 kN / m
m ² or more. The dynamic friction coefficient of the cellulose acylate film is preferably 0.40 or less, more preferably 0.35 or less. The optical film of the present invention has excellent dimensional stability, 80 ° C., 90% RH
± 0.5% when left for 12 hours at
%, More preferably less than 0.3%, more preferably less than 0.1%, more preferably 0.1%.
It is less than 08%, more preferably less than 0.06%, and still more preferably less than 0.04%.

The use of the cellulose acylate produced according to the present invention will be briefly described first, and the details will be described later. The optical film of the present invention is particularly useful for a polarizing plate protective film. When used as a protective film for a polarizing plate, the method for manufacturing the polarizing plate is not particularly limited, and the polarizing plate can be manufactured by a general method. There is a method in which the obtained cellulose acylate film is alkali-treated, and the polyvinyl alcohol film is immersed and stretched in an iodine solution, and bonded to both surfaces of the polarizer using a completely saponified polyvinyl alcohol aqueous solution. JP-A-6-9 instead of alkali treatment
An easy bonding process as described in JP-A No. 4915 and JP-A-6-118232 may be applied. Examples of the adhesive used for bonding the protective film-treated surface and the polarizer include a polyvinyl alcohol-based adhesive such as polyvinyl alcohol and polyvinyl butyral, and a vinyl-based latex such as butyl acrylate.

The polarizing plate is composed of a polarizer and a protective film for protecting both surfaces of the polarizer. Further, a protective film is bonded to one surface of the polarizing plate, and a separate film is bonded to the other surface. The protect film and the separate film are used for protecting the polarizing plate at the time of shipping the polarizing plate, at the time of product inspection, and the like. In this case, the protective film is bonded for the purpose of protecting the surface of the polarizing plate, and is used on the side opposite to the surface where the polarizing plate is bonded to the liquid crystal plate. The separate film is used for the purpose of covering the adhesive layer to be bonded to the liquid crystal plate, and is used on the side where the polarizing plate is bonded to the liquid crystal plate. In a liquid crystal display device, a substrate containing a liquid crystal is usually disposed between two polarizing plates, but a polarizing plate protective film to which the optical film of the present invention is applied can obtain excellent display properties regardless of the position. . In particular, since a transparent hard coat layer, an antiglare layer, an antireflection layer, and the like are provided on the polarizing plate protective film on the outermost surface on the display side of the liquid crystal display device, it is particularly preferable to use the polarizing plate protective film in this portion.

The cellulose acylate film of the invention can be used for various purposes, and is particularly effective when used as an optical compensation sheet for a liquid crystal display. When a cellulose acylate film is used as the optical compensation sheet, the transmission axis of the polarizing element (described later) and the slow axis of the optical compensation sheet made of the cellulose acylate film may be arranged at any angle. A liquid crystal display device has a liquid crystal cell holding liquid crystal between two electrode substrates, two polarizing elements disposed on both sides thereof, and at least one sheet between the liquid crystal cell and the polarizing element. It has a configuration in which an optical compensation sheet is arranged. The liquid crystal layer of a liquid crystal cell is usually formed by enclosing liquid crystal in a space formed by sandwiching a spacer between two substrates. The transparent electrode layer is formed on a substrate as a transparent film containing a conductive substance. The liquid crystal cell may further be provided with a gas barrier layer, a hard coat layer or an undercoat layer (used for bonding the transparent electrode layer). These layers are usually provided on a substrate. The substrate of the liquid crystal cell is generally 50 μm to 2 m.
m. The optical compensation sheet has birefringence,
It is used for the purpose of removing coloring of the display screen of the liquid crystal display device and improving the viewing angle characteristics. The cellulose acylate film of the present invention itself can be used as an optical compensation sheet. Further, a function may be provided as an antireflection layer, an antiglare layer, a λ / 4 layer, or a biaxially stretched cellulose acylate film. Further, in order to improve the viewing angle of the liquid crystal display device, the cellulose acylate film of the present invention and a film exhibiting the opposite birefringence (positive / negative relationship) may be used as an optical compensation sheet. . The thickness range of the optical compensation sheet is the same as the preferred thickness of the film of the present invention described above.

The cellulose acylate film of the present invention can be used for liquid crystal cells of various display modes. TN (Twisted Nematic), IPS (In-Plane Swit)
ching), FLC (Ferroelectric Liquid Crystal),
AFLC (Anti-ferroelectric Liquid Crystal), O
CB (Optically Compensatory Bend), STN (Suppe
Various display modes such as r Twisted Nematic), VA (Vertically Aligned) and HAN (Hybrid Aligned Nematic) have been proposed. In addition, a display mode in which the above-mentioned display mode is orientation-divided has been proposed. The cellulose acylate film is effective in a liquid crystal display device of any display mode. Further, the present invention is effective in any of the transmissive, reflective, and transflective liquid crystal display devices.

The cellulose acylate film of the present invention may be used as a support for an optical compensation sheet of a TN type liquid crystal display device having a TN mode liquid crystal cell. The TN mode liquid crystal cell and the TN type liquid crystal display device have been well known for a long time. The optical compensatory sheet used for the TN liquid crystal display device is described in JP-A-3-9325, JP-A-6-148429, JP-A-8-50206, and JP-A-9-26572. Mori et al. (Jpn. J. Appl. Phys. Vol.
36 (1997) p. 143 and Jpn.J. Appl. Phys. Vol. 36 (1997) p. 10
68). The cellulose acylate film of the invention may be used as a support for an optical compensation sheet of an STN type liquid crystal display device having an STN mode liquid crystal cell. Generally, in an STN-type liquid crystal display device, rod-like liquid crystal molecules in a liquid crystal cell are twisted in a range of 90 to 360 degrees, and the refractive index anisotropy (△ n) of the rod-like liquid crystal molecules and the cell gap (d) ) Is in the range of 300 to 1500 nm. The optical compensation sheet used for the STN liquid crystal display device is described in JP-A-2000-105316.

The cellulose acylate film of the present invention is particularly advantageously used as a support for an optical compensation sheet of a VA liquid crystal display device having a VA mode liquid crystal cell. Re of optical compensation sheet used for VA liquid crystal display device
It is preferable that the retardation value be 0 to 150 nm and the Rth retardation value be 70 to 400 nm. The Re retardation value is more preferably from 20 to 70 nm. When two optically anisotropic polymer films are used in a VA liquid crystal display device, the Rth retardation value of the film is preferably from 70 to 250 nm. When one optically anisotropic polymer film is used in a VA liquid crystal display device, the R
The th retardation value is preferably from 150 to 400 nm. VA liquid crystal display devices are disclosed in, for example,
An orientation-divided system as described in Japanese Patent Application Laid-Open No. 0-123576 may be used. The cellulose acylate film of the invention is advantageously used as a support for an optical compensation sheet of an OCB type liquid crystal display device having an OCB mode liquid crystal cell or a HAN type liquid crystal display device having a HAN mode liquid crystal cell. In the optical compensatory sheet used for the OCB type liquid crystal display device or the HAN type liquid crystal display device, it is preferable that the direction in which the absolute value of the retardation becomes minimum does not exist in the plane of the optical compensatory sheet nor in the normal direction. The optical properties of the optical compensatory sheet used in the OCB type liquid crystal display device or the HAN type liquid crystal display device also include the optical properties of the optically anisotropic layer, the optical properties of the support, and the optically anisotropic layer and the support. Is determined by the arrangement. OC
An optical compensatory sheet used for a B-type liquid crystal display device or a HAN type liquid crystal display device is disclosed in JP-A-9-197497.
There is a description in the publication. Also described in a paper by Mori et al. (Jpn. J. Appl. Phys. Vol. 38 (1999) p. 2837).

The cellulose acylate film of the present invention can be made of TN type, STN type, HAN type, GH (Guest-Host).
It is also used advantageously as an optical compensation sheet of a reflection type liquid crystal display device. These display modes have been well known since ancient times. The TN type reflection type liquid crystal display device is described in JP-A-10-123478, WO98848320, and Japanese Patent No. 30222477. Regarding the optical compensation sheet used for the reflection type liquid crystal display device, WO00
-65384. The cellulose acylate film of the present invention is manufactured by ASM (Axially Symmetric).
ASM with liquid crystal cell in Aligned Microcell) mode
It is also advantageously used as a support for an optical compensation sheet of a liquid crystal display device. The ASM mode liquid crystal cell is characterized in that the thickness of the cell is maintained by a resin spacer whose position can be adjusted. Other properties are the same as those of the TN mode liquid crystal cell. As for the ASM mode liquid crystal cell and the ASM type liquid crystal display device, a paper by Kume et al.
me et al., SID98 Digest 1089 (1998)). Hereinafter, specific embodiments of the cellulose acylate of the present invention will be described, but the present invention is not limited thereto.

[0105]

EXAMPLES In each of the examples, cellulose acylate,
The chemical and physical properties of solutions and films are
It was measured and calculated as follows.

(1) Peeling residue of the film The surface of the support when peeling the obtained film from the support was visually observed, and the peeling residue of the cellulose acylate film was evaluated as follows. A: No peeling is observed on the support. B: Slight peeling was observed on the support. C: Peeling residue was considerably observed on the support. D: A large amount of peeling was observed on the support.

(2) Lateral unevenness of the film (abbreviated as unevenness) The obtained film was visually observed, and the defect of the horizontal unevenness was evaluated as follows. A: No horizontal unevenness is found on the film. B: Horizontal unevenness was slightly observed in the film. C: Horizontal unevenness was considerably observed in the film. D: A large amount of horizontal unevenness was observed in the film.

(3) Film spots (abbreviated as spots) The obtained film was visually observed, and spots on the surface were evaluated as follows. A: No bumps were found on the film surface. B: Slight bumps were observed on the film surface. C: Significant bumps were observed on the film surface. D: Irregularities were observed on the film surface, and a lot of bumps were observed.

(4) Alkaline Hydrolysis Characteristics of Film A 100 mm × 100 mm sample was subjected to automatic alkali saponification.
2N hydroxylation at 60 ° C with a processing device (manufactured by Shinto Kagaku Co., Ltd.)
Saponify with sodium aqueous solution for 3 minutes, wash with water for 4 minutes
Was. Next, the sample was heated at 30 ° C. and 0.01N diluted nitric acid for 4 minutes.
And neutralized for 4 minutes. Then, at 100 ° C,
3 minutes, air drying 1 hour, visually evaluate the following
Was. A: No whitening is observed. B: Whitening is slightly observed. C: Whitening is considerably observed. D: Whitening is remarkably observed.

Example 1 (1-1) Preparation of Cellulose Acylate Solution In a 5 liter glass container having stirring blades, while stirring and dispersing well in a solvent mixed solution described below, the acid described in Table 1 was used. A polymer having a carboxylic acid or a salt thereof having a dissociation index (pKa, 25 ° C.) of 4.4 or less is gradually added, and a total of 2
kg. The solvents methyl acetate, butanol, acetone, methanol, and ethanol all used had a water content of 0.2% by mass or less. First, a powder of cellulose triacetate was charged into a dispersion tank, charged with nitrogen gas, and dispersed for 30 minutes by a dissolver type eccentric stirring shaft and a stirrer having an anchor blade at the center axis. Dispersion start temperature is 30
° C. After the dispersion, the high-speed stirring was stopped, and the peripheral speed of the anchor blade was set to 0.5 m / sec, and the mixture was further stirred for 100 minutes to swell the cellulose triacetate flakes. 0.12MP in the tank with nitrogen gas until swelling ends
a. At this time, the oxygen concentration in the tank was less than 2 vol%, and a state in which there was no problem in explosion protection was maintained. It was also confirmed that the water content in the dope was 0.2% by mass or less.

The cellulose acylate solution was prepared from cellulose triacetate (substitution degree: 2.82, viscosity average polymerization degree: 32).
0, water content 0.4 mass%, 6 in methylene chloride solution
Mass% viscosity 305 mPa · s, average particle size 1.5 m
m, powder having a standard deviation of 0.5 mm) 20 parts by mass, methyl acetate 58 parts by mass, acetone 5 parts by mass, methanol 5 parts by mass, ethanol 5 parts by mass, butanol 5 parts by mass, ditrimethylolpropane tetraacetate ( 1.2 parts by mass of plasticizer A), 1.2 parts by mass of triphenyl phosphate (plasticizer B), 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di- tert-butylanilino) -1,3,5-triazine (UV agent a)
0.2 parts by mass, 2- (2'-hydroxy-3 ', 5'-
0.2 parts by mass of di-tert-butylphenyl) -5-chlorobenzotriazole (UV agent b), 2- (2′-hydroxy-3 ′, 5′-di-tert-amylphenyl) -5
0.2 parts by mass of chlorobenzotriazole (UV agent c)
Silicon dioxide fine particles (particle diameter 20 nm, Mohs hardness about 7)
It has a composition consisting of 0.05 parts by mass and the carboxylic acid shown in Table 1 (the amount shown in Table 1). The solubility parameter of methyl acetate as the main solvent was 19.
6, and the acetone used in combination has a solubility parameter of 20.3. Cellulose triacetate has a residual acetic acid content of 0.1% by mass or less, 0.05% by mass of Ca, 0.007% by mass of Mg, and 5% by mass of Fe.
pm. The 6-position acetyl group was 0.95, which was 32.2% of the total acetyl. The acetone extractables were 11% by mass, the ratio of the weight average molecular weight to the number average molecular weight was 0.5, and the distribution was uniform. The haze is 0.08, the transparency is 93.5%, and the Tg is 160
° C, and the heat of crystallization was 6.2 J / g.

(1-2) Cellulose triacetate film solution The resulting non-uniform gel solution was fed by a screw pump and passed through a cooling part at -70 ° C for 3 minutes. Cooling was carried out using a −80 ° C. refrigerant cooled by a refrigerator. Then, the solution obtained by cooling is transferred to a stainless steel container, and stirred at 50 ° C. for 2 hours.
The solution was filtered through 3), and further filtered through a filter paper (FH025, manufactured by Pall Corporation) having an absolute filtration accuracy of 2.5 μm.

(1-3) Preparation of Cellulose Triacetate Film A filtered cellulose triacetate solution at 50 ° C.
It was cast on a mirror-finished stainless steel support through a casting gieser. The temperature of the support was 5 ° C., the casting speed was 3 m / min, and the coating width was 30 cm. It was left at room temperature for 1 minute, and then a drying air at 55 ° C. was blown for drying. After 5 minutes, peel off the mirror-finished stainless steel support, and then 11
It was dried at 0 ° C. for 10 minutes and further at 150 ° C. for 30 minutes (film temperature was about 140 ° C.) to obtain a cellulose triacetate film (film thickness: 80 μm).

(1-4) Results Table 1 shows the peeling residue obtained when a polymer having a carboxylic acid or a salt thereof having an acid dissociation index (pKa, 25 ° C.) of 4.4 or less according to the present invention is used. , Film surface (uneven,
(Bumps) and the evaluation results of the alkali hydrolysis characteristics are described. The control sample 1-1 which does not use a polymer having a carboxylic acid or a salt thereof having an acid dissociation index (pKa, 25 ° C.) of 4.4 or less according to the present invention has significant peeling off,
The unevenness, spots and alkali hydrolysis characteristics were also very poor. In contrast, Samples 1-2 to 1-11 of the present invention
Had no peeling residue, no unevenness and no bumps, and had excellent alkali hydrolysis properties. In contrast, comparative compounds A, B, and C, which are comparative polycarboxylic acids other than the present invention.
And Comparative Samples 1-11-2-15 using D and D had poor lumps and insufficient alkali hydrolysis properties.

[0115]

[Table 1]

Example 2 Sample 2-4 was obtained in exactly the same manner as in Example 1 except that (1-2) the cellulose triacetate film solution was changed as follows.

(1-2) Cellulose triacetate film solution The resulting non-uniform gel solution was fed by a screw pump and passed through a heated portion heated and pressurized to 130 ° C. and 15 Mpa for 3 minutes. , 110 ° C., 1 Mpa, heated and pressurized, and filtered through a filter paper (manufactured by Toyo Roshi Kaisha, Ltd., # 63) with an absolute filtration accuracy of 0.01 mm. ).

(2-1) Results Sample 2-4 of the present invention obtained had good filterability, no peeling residue, and was excellent in unevenness, spots, and alkali hydrolysis characteristics. From this, it was confirmed that in the present invention, a cellulose acetate solution and a cellulose acetate film excellent in high-temperature and high-pressure dissolution can be produced.

Example 3 Sample 3-4 of the present invention was prepared in the same manner as in Example 1 except that both plasticizers A and B were removed as 0 parts by mass. Produced. The obtained sample 3-4 has no peeling, unevenness,
The spots were both A, and the alkaline hydrolysis property was A, which was excellent. On the other hand, when the bending resistance test was performed, Sample 1-4 was 117 times, whereas Sample 3-4 which was within the scope of the present invention but did not have a plasticizer had a cut resistance test of 1 times.
There was no practical problem with 02 times, but it was slightly inferior. Therefore, it is clear that in the present invention, it is a more preferable embodiment that the cellulose acylate film contains a plasticizer. Here, the evaluation of the bending strength was performed using a sample of 120 mm ×
120 mm is conditioned at 23 ° C. and 65% RH for 2 hours,
According to ISO 8776-1988, the number of reciprocations until cutting by bending was measured and evaluated.

Example 4 Sample 4-6 of the present invention was prepared in exactly the same manner as in Example 1 except that UV agents a, b, and c were all removed as 0 parts by mass in Sample 1-6 of Example 1. Was prepared. The obtained sample 4-6 has no peeling, unevenness,
The spots were evaluated as A, and the alkaline hydrolysis properties were also excellent as A. On the other hand, when the light fading test was carried out for one month with a xenon lamp of 30,000 lux, samples 1-3 were obtained.
Has a haze of 0.4%, which is within the range of the present invention, but the alkali hydrolysis characteristics of Sample 4-6 are slightly deteriorated to B. Therefore, it is clear that in the present invention, it is a more preferable embodiment that the cellulose acylate film contains a UV agent.

Example 5 A sample 5-6 of the present invention was produced in exactly the same manner as in Example 1 except that the fine particles of silica were removed as 0 parts by mass in Sample 1-6 of Example 1. The obtained sample 5-6 had no peeling, and the unevenness and spots were evaluated as A, and the alkali hydrolysis property was also A, which was excellent. On the other hand, when the two films were piled up and examined for slipperiness, Sample 1-3 could be moved smoothly, whereas Sample 5-6 was within the scope of the present invention. The movement was a little bad.
Therefore, it is clear that in the present invention, it is a more preferable embodiment that the cellulose acylate film contains fine particles.

Example 6 Sample 1 of the present invention of Example 1
7, a cellulose triacetate film of Sample 6-7 of the present invention was prepared in exactly the same manner as in Example 1 except that the preparation of (1-2) cellulose triacetate film of Example 1 was changed as follows. That is, (1-
A part of the cellulose triacetate solution obtained in 2) was sampled, and a cellulose triacetate solution (solution A) was prepared by diluting with 10% by mass of methyl acetate. According to the co-casting method described in JP-A-06-134993, the obtained solution was laminated and co-cast with the cellulose triacetate solution of Sample 1-3 and on both sides thereof. Then, a co-cast cellulose triacetate film was obtained. The film thickness was 3 μm on both sides and 34 μm inside, so that the total thickness was 40 μm. The surface condition of the obtained sample 6-7 was smoother than that of the sample 1-3, and was more excellent without unevenness. Therefore, it is clear that co-casting is a more excellent aspect in the present invention.

[Example 7] In Example 1 described in JP-A-11-316378, the first transparent support was replaced with the cellulose triacetate film (second Film) thickness 100
Example 1 described in JP-A-11-316378 was carried out in exactly the same manner except that the thickness was changed to μm, thereby producing a sample 7-3. The obtained elliptically polarizing plate had excellent optical characteristics. Therefore, it is clear that the use of a specific washing solution in the production process of the present invention is a preferable embodiment without any problem even if the cellulose acylate film produced thereafter is applied to an optical polarizing plate.

Example 8 Sample 1 of the present invention of Example 1
No. 3 in the cellulose triester film of No. 3
No. 33433, cellulose triacetate manufactured by Fuji Photo Film Co., Ltd. of Example 1 was used as the sample 1 of the present invention.
Example 1 described in JP-A-7-333433 except that the cellulose triacetate film of No. -6 was used.
An optical compensation filter film sample was prepared in exactly the same manner as described above. The obtained filter film had excellent viewing angles in the right, left, up and down directions. Therefore, it is understood that the cellulose triacetate film of the present invention is excellent for optical use.

Ninth Embodiment In the present invention, a liquid crystal display device which is used for various kinds of optical applications and which is a representative example of the present invention is described in Example 1 of Japanese Patent Application Laid-Open No. 10-48420. Example 1 of JP-A-9-26572
20. An optically anisotropic layer containing discotic liquid crystal molecules, an alignment film coated with polyvinyl alcohol,
Good performance can be obtained by using the VA-type liquid crystal display device described in FIGS. 2 to 9 of 00-154261 and the OCB type liquid crystal display device of FIGS. 10 to 15 of JP-A-2000-154261. Was.

Example 10 Sample 1 of the present invention of Example 1
-3, a sample 10-3 of the present invention, which is a film thereof, was produced in exactly the same manner as in Example 1 except that the film thickness was changed to 120 μm. Example 1 described in JP-A-4-73736 was added to one of the obtained films.
(Back layer composition) The first layer and the second layer were applied to prepare a back layer having a cationic polymer as a conductive layer. Further, the sample 105 of Example 1 described in JP-A-11-38568 was applied to the opposite side of the film base provided with the obtained back layer, to prepare a silver halide color photographic light-sensitive material. The obtained color film was excellent in image quality and had no problem in handling.

[0127]

According to the present invention, it is possible to provide a solution having good peeling properties when the film is peeled off after casting on a support of a cellulose acylate solution in the production process. Further, the cellulose acylate film solution of the present invention can provide a cellulose acylate film free from unevenness and unevenness. Further, a cellulose triester film having excellent optical anisotropy and excellent film strength can be provided. Further, a cellulose triacetate film excellent as a support for a light-sensitive material can be produced.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) G02B 5/30 G02B 5/30 G03C 1/795 G03C 1/795 // B29K 1:00 B29K 1:00 B29L 7:00 B29L 7:00 F term (reference) 2H023 FA01 FA13 2H049 BA02 BA06 BB33 BB51 4F071 AA09 AC10 AC12 AE22 AH16 AH19 BA02 BB02 BC01 4F205 AA01 AB07 AB10 AB11 AB14 AC05 GA07 GB02 GC02 GC07 GE22 GE24 4J002 AB02E EPH

Claims (13)

[Claims] 1. A cellulose acylate, comprising a carboxylic acid or a salt thereof in an amount of 0.01 to 2.5% by mass of the cellulose acylate, wherein the carboxylic acid or a salt thereof has at least two ester bonds or amide bonds. A cellulose acylate film having a molecular structure containing: 2. The cellulose acylate film according to claim 1, wherein the acyl substitution degree of the cellulose acylate is from 2.60 to 3.00. 3. The cellulose acylate film according to claim 1, wherein the degree of substitution of the cellulose acylate with an acetyl group is from 2.00 to 3.00. 4. The cellulose acylate having 3 carbon atoms.
The degree of substitution with the acyl group of from 22 to 22 is 0.00
2. The cellulose acylate film according to claim 1, which has a molecular weight of from 0.8 to 0.80. 5. The cellulose acylate is substituted with an acetyl group and an acyl group having 3 to 22 carbon atoms, and 30% or more of the acyl groups having 3 to 22 carbon atoms are substituted with a 6-position hydroxyl group. The cellulose acylate film according to claim 1, which is present as a base. 6. The cellulose acylate film according to claim 1, wherein the degree of acyl substitution at the 6-position of the cellulose acylate is from 0.80 to 1.00. 7. The cellulose acylate film according to claim 1, wherein the carboxylic acid or a salt thereof has at least one carboxyl group having an acid dissociation index of 4.4 or less. 8. The cellulose acylate film according to claim 1, wherein the carboxylic acid is an oligomer having 3 to 10 repeating units linked by 2 to 9 ester bonds or amide bonds. 9. A method for producing a cellulose acylate film by applying a cellulose acylate solution obtained by dissolving cellulose acylate in an organic solvent, wherein the cellulose acylate solution contains 0.002 to 0.5% by mass. A carboxylic acid or a salt thereof, wherein the carboxylic acid or a salt thereof has a molecular structure containing at least two ester bonds or amide bonds. 10. The production method according to claim 9, wherein the organic solvent comprises a substantially non-chlorinated organic solvent. 11. An organic solvent having 2 to 12 carbon atoms.
The method according to claim 9, wherein the ether is selected from the group consisting of: an ether, a ketone having 3 to 12 carbon atoms, and an ester having 2 to 12 carbon atoms. 12. The method according to claim 9, wherein the organic solvent is methylene chloride. 13. The cellulose acylate solution contains a plasticizer in an amount of 0.1 to 20% by mass based on the cellulose acylate and an ultraviolet absorber in an amount of 0.1 to 20% by mass based on the cellulose acylate.
001 to 5% by mass, fine particles 0.001 to 5% by mass with respect to cellulose acylate, or a fluorine-based surfactant with 0.001 to 5% by mass with respect to cellulose acylate.
The production method according to claim 9, wherein the content is from 2 to 2% by mass.