JP2002265639A - Cellulose acylate film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cellulose acylate film having an excellent planar state. SOLUTION: This cellulose acylate film is produced from a solution obtained by dissolving a cellulose acylate in which the degree of substitution of hydroxy group of cellulose satisfies all of the following formulas (I) 2.6<=SA+SB<=3.0, (II) 2.0<=SA<=3.0 and (III) 0<=SB<=0.8 (SA is the degree of substitution of acetyl group substituting the hydroxy group of the cellulose and SB is the degree of substitution of a 3-22C acyl group substituting the hydroxy group of the cellulose), a <=22C polyfunctional carboxylic acid derivative having <=4.4 acid dissociation exponent and containing a carboxy group (may be in a salt state) in an organic solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cellulose acylate film useful for a silver halide photographic material or a liquid crystal image display.

[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 having a higher concentration to reduce the amount of solvent used was examined, 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 the like. 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
Etc. are described in Makromol. chem. In volume 143, page 105 (1971), cellulose triacetate (degree of acetylation: 60.1% to 61.3%) was added at -80 ° C in acetone.
To -70 ° C and then warmed to 0.
It reports that 5 to 5% by weight of dilute solution is obtained. Such a method of dissolving cellulose acylate at a low temperature is called a cooling dissolution method. In addition, Kenji Ude et al. Described spinning technology using a cooling dissolution method in "Dry spinning of cellulose triacetate from an acetone solution" in Textile Machinery Society, Vol. 34, pp. 57-61 (1981). I have.

[0004] Further, in each of JP-A-9-95538, JP-A-9-95544 and JP-A-9-95557, cellulose acylate is produced by cooling and dissolving using a non-chlorine-based organic solvent against the background of the above technology. Dissolving the rate 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 JP-A-11-60752, the transparency and stability of cellulose triacetate solutions prepared by these methods must be removed beforehand to remove the low polymerization degree portion of the cellulose triacetate, and the reproducibility of the cellulose triacetate solution is poor. In order to solve the complication that the 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 of 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 is not sufficiently peeled from the cast metal support during the production thereof, and improvement thereof 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 1.93-4.
50 [preferably 2.0 to 4.4, more preferably 2.2 to 4.3 (e.g., 2.5 to 4.0), particularly 2.0.
About 6 to 4.3 (for example, about 2.6 to 4.0)] or a salt thereof is preferred as a release agent. However, as a drawback, it is a problem of producing a fine salt with the alkaline earth metal contained in the cellulose acylate in a cellulose acylate solution and causing a problem of adhering to the system in a long casting process. There was expected improvement.

[0007]

Accordingly, when a solution of cellulose acylate in a non-chlorine organic solvent is prepared by a cooling dissolution method or a high-temperature and high-pressure dissolution method, it is cast and then separated from the support for drying. Is to solve the difficulties, and to produce an excellent planar cellulose acylate film. The object of the present invention is to dissolve a cellulose acylate solution prepared by a chlorine-based organic solvent, more preferably a non-chlorine-based organic solvent at room temperature, a cooling dissolution method or a high-temperature and high-pressure dissolution method, to obtain a cellulose having excellent surface properties. It is to provide a cellulose film. Further, the object of the present invention is to easily peel the film from the support for drying after casting,
It is to provide excellent productivity.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cellulose acylate in which the degree of substitution of cellulose with a hydroxyl group satisfies all of the following formulas (I) to (III): Cellulose acylate prepared from a cellulose acylate solution containing 0.002 to 2% by mass of a polycarboxylic acid derivative having at least one carboxyl group or a salt thereof having an acid dissociation index (pKa, 25 ° C) of 4.4 or less. Achieved by the film: (I) 2.6 ≦ SA + SB ≦ 3.0 (II) 2.0 ≦ SA ≦ 3.0 (III) 0 ≦ SB ≦ 0.8 where SA and SB are cellulose Represents a substituent of an acyl group substituted by a hydroxyl group, SA represents the degree of substitution of an acetyl group, and SB represents the degree of substitution of an acyl group having 3 to 22 carbon atoms.]

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The cellulose acylate used in the present invention is a cellulose acylate in which a hydroxyl group of cellulose is substituted by an acetic acid group (SA) and an acyl group having 3 to 22 carbon atoms (SB), The sum of the degree of substitution of SA + SB is 2.60 to 3, and the degree of substitution of SB is 0 to 3.
0.8. Glucose units having β-1,4 bonds constituting cellulose have free hydroxyl groups 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 is 2
For each of the 3-, 3-, and 6-positions, the ratio of cellulose esterification (100% esterification means 1 substitution degree). In the present invention, the sum of the degrees of substitution of SA and SB of the hydroxyl group is more preferably 2.7 to 2.96, and particularly preferably 2.80 to 2.95. Also,
The substitution degree of SB is 0 to 0.8, particularly 0 to 0.6. Further, in SB, at least 28% is a substituent of a 6-position hydroxyl group, more preferably at least 30% is a substituent of a 6-position hydroxyl group, further preferably 31%, particularly preferably 32%.
It is also preferable that the above is a substituent of the 6-position hydroxyl group. Further, there may be mentioned a cellulose acylate film in which the total degree of substitution of SA and SB at the 6-position of cellulose acylate is 0.8 or more, more preferably 0.85, especially 0.90. These cellulose acylate films make it possible to prepare a solution having good solubility, and particularly to prepare a good solution in a non-chlorine organic solvent.

The acyl group (SB) having 3 to 22 carbon atoms of cellulose acylate may be an aliphatic group or an allyl group, and is not particularly limited. These are, for example, alkyl carbonyl esters, alkenyl carbonyl esters or aromatic carbonyl esters of cellulose, aromatic alkyl carbonyl esters and the like, each of which may have a further substituted group. These preferred SBs
Is propionyl, butyryl, heptanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, isobutyryl, t-butyryl, cyclohexanoyl, oleoyl, benzoyl, naphthoyl or 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.

[0012] In the cellulose acylate film of the present invention, it is preferable that the polymer component constituting the film substantially comprises cellulose acylate having the above-mentioned definition. "Substantially" means 90% by mass or more (preferably 95% by mass or more, more preferably 98% by mass or more of the polymer component).
% By mass or more, most preferably 99% by mass or more). It is preferable to use cellulose acylate particles as a raw material for producing a film. 9 of the particles used
If it is 0% by mass or more, it preferably has a particle size of 0.5 to 5 mm. Further, it is preferable that 50% by mass or more of the particles used have a particle diameter of 1 to 4 mm. It is preferable that the cellulose acylate particles have a shape as close to spherical as possible.

The polymerization degree of the cellulose acylate is preferably from 200 to 700, more preferably from 2 to 700.
50 to 550, more preferably 250 to 400,
Most preferably, it is 250-350. The average degree of polymerization is
Uda et al.'S limiting viscosity method (Kazuo Uda, Hideo Saito, Journal of the Textile Society of Japan, Vol. 18, No. 1, pp. 105-120, 1962)
Can be measured. Further, it is described in detail 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 used at the time of producing the cellulose acylate of the present invention, the water content is preferably 2% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.7% by mass or less. It is a cellulose acylate having a ratio. Generally, cellulose acylate contains water and has a content of 2.5%.
~ 5% by mass is known. In order to obtain the water content of the cellulose acylate in the present invention, it is necessary to dry the cellulose acylate. The method is not particularly limited as long as the desired water content is obtained.

Next, a polycarboxylic acid derivative having a carboxyl group or a salt thereof having an acid dissociation index (pKa, 25 ° C.) of 4.4 or less will be described in detail. The acid dissociation index of the carboxyl group is preferably pKa 1.9 to 4.
4, more preferably 2.0 to 4.0, even more preferably 2.0 to 3.9, and the obtained cellulose acylate film has good surface condition. Further, when the cellulose acylate solution is cast on a metal support and peeled off, the cellulose acylate solution can be easily peeled off, which is preferable in view of production suitability. The carboxyl group may be in a salt state. More specific preferred polycarboxylic acid derivatives having a carboxyl group or a salt thereof include polycarboxylic acid derivatives,
A hydrocarbon polycarboxylic acid ester containing at least one carboxylic acid or a salt thereof, a hydrocarbon polycarboxylic acid amide, an aromatic polycarboxylic acid ester, an aromatic polycarboxylic acid amide, a heterocyclic polycarboxylic acid ester; It is a multivalent carboxylic acid amide.

First, the polycarboxylic acid forming the polycarboxylic acid derivative will be described. The hydrocarbon polycarboxylic acid may be substituted or unsubstituted. For example, oxalic acid (1.27), malonic acid (pKa: 2.6)
5), succinic acid (4.00), glutaric acid (4.1)
3), adipic acid (4.26), pimelic acid (4.3)
1), azelaic acid (4.39), fumaric acid (2.8)
5) and the like, and malic acid (3.24), tartaric acid (2.
82-2.99), citric acid (2.87), phthalic acid (2.75), which is an aromatic polycarboxylic acid, isophthalic acid (3.50), terephthalic acid (3.54), trimellitic acid And 2,6-pyridinedicarboxylic acid (2.09) as a heterocyclic polycarboxylic acid such as 4-methylphthalic acid. Further, amino acids may be used as the organic acid, and for example, aspartic acid (1.93), glutamic acid (2.18) and the like are used. Among these, malonic acid which is an aliphatic polycarboxylic acid, succinic acid,
Glutaric acid, fumaric acid, malic acid, tartaric acid, citric acid and the like are preferred.

The polycarboxylic acid derivative preferably has an ester group or an amide group as the above-mentioned preferable one. First, the ester group is preferably a substituted or unsubstituted alkyl group, alkenyl group, or allyl group, and has a total carbon number of 1 to 200, more preferably 1 to 10
0, and 1 to 50. As the substituent of the alkyl group, alkenyl group and allyl group, a (poly) oxyalkylene group is preferable, and a (poly) oxyalkylene group is particularly preferably a poly (oxyethylene) group, a (poly) oxypropylene group, a (poly) oxy It is preferably a butylene group or a (poly) oxyglycerin group. The amide derivative, which is a preferred embodiment of the polycarboxylic acid derivative, is primary,
It may be substituted or unsubstituted secondary or tertiary, and is not particularly limited. As the substituent, an alkyl group, an alkenyl group, and an allyl group are preferable, and the total carbon number is 1 to
200, more preferably 1 to 100, and even more preferably 1 to 50. As the substituent of the alkyl group, alkenyl group and allyl group, a (poly) oxyalkylene group is preferable, and a (poly) oxyalkylene group is particularly preferably a poly (oxyethylene) group, a (poly) oxypropylene group, a (poly) oxy It is preferably a butylene group or a (poly) oxyglycerin group.

The aforementioned acids may be used as free acids,
It may be used in the form of a salt, for example, an alkali metal salt, an alkaline earth metal salt, or a heavy metal salt. As an alkali metal,
Lithium, potassium, sodium and the like can be exemplified, and as the alkaline earth metal, calcium, magnesium, barium, strontium and the like can be exemplified. Examples of heavy metals or transition metals include aluminum, zinc, tin, nickel, iron, lead, copper, and silver. Also preferred are substituted and unsubstituted amines having 5 or less carbon atoms, such as ammonium, methylamine, ethylamine, propylamine, butylamine, dimethylamine, trimethylamine, triethylamine, hydroxyethylamine, di (hydroxyethyl) amine, and tri (hydroxyethyl) amine. Ethyl) amine and the like can be used. Preferred alkali metals include sodium, and preferred alkaline earth metals include calcium and magnesium. These alkali metals and alkaline earth metals can be used alone or in combination of two or more, and alkali metals and alkaline earth metals may be used in combination. The total content of the acid and its metal salt is in a range that does not impair the releasability, transparency, film forming property, etc., for example, 1 g per 1 g of cellulose acylate.
× 10 ^{-9 to} 3 × 10 ^-5 mol, preferably 1 × 10 ^-8 to 2
× 10 ⁻⁵ mol (for example, 5 × 10 ^{−7 to} 1.5 × 10 ⁻⁵ mol), more preferably 1 × 10 ⁻⁷ to 1 × 10 ⁻⁵ mol (for example, 5 × 10 ⁻⁶ to 8 ×) 10 ^-6 mol), and usually about 5 × 10 ^{-7 to} 5 × 10 ^-6 mol (for example, 6 × 10 ^{-7 to} 3 × 10 ^-6 mol). Particularly preferred specific compounds among the above-mentioned polyvalent carboxylic acid derivatives are described below, but are not limited thereto.

RK-1: HOOC (CH ₂ ) _k CO (OCH ₂ CH ₂ ) _m OR; R = CH ₃ , k =
0, m = 6 RK-2: HOOC (CH ₂ ) _k CO (OCH ₂ CH ₂ ) _m OR; R = C ₄ H ₉ , k
= 0, m = 10 RK-3: HOOC (CH ₂ ) _k CO (OCH ₂ CH ₂ ) _m OR; R = C ₂ H ₅ , k
= 1, m = 5 RK-4: HOOC (CH ₂ ) _k CO (OCH ₂ CH ₂ ) _m OR; R = C ₈ H ₁₇ , k
= 2, m = 10 RK- 5: HOOC-CH 2 CH (OH) -COOR; R = CH 3 RK-6: HOOC-CH 2 CH (OH) -COOR; R = CH 2 CH (OH) CH 2 O) ₅
H RK-7: HOOC-CH 2 CH (OH) -COOR; R = (CH 2 CH 2 O) 5 -OC 4
H ₉ RK-8: HOOC—CH (OH) —CH (OH) —COOR; R = (CH ₂ CH ₂ O) ₃ —O
_{C 4 H 9 RK-9:} HOOC-CH (OH) -CH (OH) -COOR; R = (CH 2 CH 2 O) 10 -O
_{C 4 H 9 RK-10:} HOOC-CH (OH) -CH (OH) -COOR; R = (CH 2 -CH (CH 3) -
CH ₂ O) _3- (CH ₂ CH ₂ O) ₅ H RK-11: mono-citrate-ethoxy-tri (ethylene glycol) ester RK-12: di-butoxy-hexa- (ethylene glycol) citrate RK -13: Citrate di {ethoxy-tri (ethylene glycol)} ester RK-14: Monophthalic acid {ethoxy-penta (ethylene glycol)} ester RK-15: Monoisophthalate {dodecyloxy-deca (ethylene glycol)} Ester RK-16: trimellitic acid di {butoxy-penta (ethylene glycol)} ester RK-17: N-acetyl-aspartic acid mono {butoxy-hepta (ethylene glycol)} ester RK-18: 2,6-pyridinedicarboxylic acid Acid mono {ethoxy-penta (ethylene glycol)} ester RK-19: 2,6-pyridinedicarboxylic acid mono {penta (ethyl Len glycol)｝ ester

RK-20: methyl tartrate RK-21: dimethyl citrate RK-22: HOOC-CH = CH-COO (CH ₂ CH ₂ ) ₇ -C ₂ H ₉ RK-23: HOOC-CH _2- CONR ₁・ R ₂ ; R ₁ = H, R ₂ = (CH ₂ CH
₂ O) ₅ H RK-24: HOOC-CH ₂ -CONR ₁ · R ₂ ; R ₁ = R ₂ = (CH ₂ CH ₂ O)
₅ H RK-25: HOOC-CH (OH) -CH ₂ CONH (CH ₂ CH ₂ O) ₅ H RK-26: HOOC-CH (OH) -CH ₂ CON [(CH ₂ CH ₂ O) ₃ H] _{2 RK-27: HOOC-CH} (OH) -CH (OH) -CON [(CH 2 CH 2 O) 5 H] 2 H RK-28: citric acid mono {N- octa (ethylene glycol)} amide RK- 29: terephthalic acid monomethyl {N- Butokishideka (ethylene glycol)} amide _{RK-30: NaOOC (CH 2} ) k CO (OCH 2 CH 2) m OR; R = C 2 H 5,
k = 0, m = 15 RK-31: KOOC (CH ₂ ) _k CO (OCH ₂ CH ₂ ) _m OR; R = C ₄ H ₉ , k
= 0, m = 10 RK- 32: Ca [OOC (CH 2) k CO (OCH 2 CH 2) m OR] 2; R = C 2 H
_{5, k = 1, m =} 5 RK-33: NH 3 OOC-CH 2 CH (OH) -COOR; R = CH 3 RK-34: LiOOC-CH 2 CH (OH) -COOR; R = CH 2 CH (OH) CH ₂ O)
₅ H RK-35: Mg [OOC-CH (OH) -CH (OH) -COOR] ₂ ; R = (CH ₂ CH
₂ O) ₃ -OC ₄ H ₉ RK-36: Na salt of citric acid mono {ethoxy-tri (ethylene glycol)} ester RK-37: Na salt of di {butoxy-hexa (ethylene glycol) citric acid ester RK -38: K salt of di-ethoxy-tri (ethylene glycol) citrate RK-39: Na salt of mono-ethoxy-penta (ethylene glycol) phthalate RK-40: Di-butoxy trimellitate Li salt of penta (ethylene glycol)｝ ester RK-41: Na salt of dimethyl tartrate RK-42: Trihydroxyethylamine salt of dimethyl citrate RK-43: NaOOC-CH = CH-COO (CH ₂ CH ₂ ) ₇ -C ₂ H ₉ RK-44: NaOOC-CH (OH) -CH ₂ CONH (CH ₂ CH ₂ O) ₅ H RK-45: KOOC-CH (OH) -CH ₂ CON [(CH ₂ CH ₂ O ) ₃ H] ₂ RK-46: Na salt of di {N-octa (ethylene glycol)} citrate amide

The cellulose acylate solution is preferably peeled off from the metal support at 20 to 1000% by weight (% of solution weight divided by solid weight) after casting, and generally, a release agent is used. If not, peeling is difficult unless the amount is 20 to 150% by mass, and there is a disadvantage that drying time is required. On the other hand, the cellulose acylate solution containing the release agent can be released even when the residual solvent is 20 to 500% by mass, so that the drying time can be shortened and the productivity can be greatly improved. Further, by containing a release agent, the peeling load at the time of peeling could be remarkably reduced, whereby the surface condition was remarkably improved. Such a cellulose acylate film has high releasability from a metal support in the production of a film by a casting method, and can improve the film-forming speed and, consequently, the productivity of the cellulose acylate film. Further, the cellulose acylate film is excellent in optical properties such as transparency, and its transparency is, for example, 60 to 100% (preferably 70 to 100%,
More preferably about 75 to 100%), and usually 7
It is about 0 to 98%, and the haze is 0.01 to 8%, preferably 0.02 to 5%. Furthermore, the yellowness index (Yellowness Index, YI) as an index of the yellowness of cellulose acetate is, for example, 0.05 to 1
0, preferably 0.08 to 7. In the cellulose acylate solution, various additives (for example, a plasticizer, an ultraviolet ray inhibitor, a deterioration inhibitor,
Microparticles, optical property modifiers, etc.).
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 preferred plasticizer in the present invention has a boiling point of 200
Above, liquid at 25 ° C. or melting point of 25 to 25
It is preferably a solid at 0 ° C. More preferably, it is liquid at a boiling point of 250C or higher at 25C or has a melting point of 2C.
Plasticizers that are solid at 5-200 ° C. are included. 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 (DMP)
EP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP)
And diethylhexyl phthalate (DEHP). 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 are liquid at 25 ° C except TPP (melting point about 50 ° C) and have a boiling point of 25 ° C.
0 ° C. or higher.

Examples of other carboxylic esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic 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 Examples include propyl glycolate, butyl phthalyl butyl glycolate, and octyl phthalyl octyl glycolate. Among them, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate,
Preferred are tributyl phosphate, dimethyl phthalate, 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 addition amount of the plasticizer is 2 to 30% by mass based on the cellulose acylate,
Particularly, 5 to 20% by mass is preferable. In addition, in the present invention, as plasticizers for reducing the optical anisotropy, (di) pentaerythritol esters described in JP-A-11-124445 and glycerol esters described in JP-A-11-246704 are used. JP-A-2000-6
Diglycerol esters described in JP-A-3560, citrate esters described in JP-A-11-92574, and substituted phenyl phosphate esters described in JP-A-11-90946 are preferably used.

To the cellulose acylate film, an antioxidant (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. Regarding these deterioration inhibitors and ultraviolet inhibitors, JP-A-60-235852, JP-A-3-199201, JP-A-5-1907073, JP-A-5-194789, JP-A-5-271471,
JP-A-6-107854, JP-A-6-118233
JP-A-6-148430, JP-A-7-11056
JP-A-7-11055, JP-A-7-11056
JP-A-8-29619, JP-A-8-239509
JP-A-7-11056, JP-A-2000-2041
No. 73, 5-1970073, JP-A-5-194789
JP-A-6-107854, JP-A-60-2358
No. 52, JP-A-12-193821, JP-A-8-29
No. 619, JP-A-6-118233, JP-A-6-14
No. 8430 is described in each gazette. The amount of these additives
It is preferably from 0.01 to 1% by mass of the solution (dope) to be prepared, and more preferably from 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 preferred in the present invention has a boiling point of 200 or more and 2
It is preferably a liquid at 5 ° C or a solid with a melting point of 25-250 ° C. More preferably, the boiling point is 2
Liquid at 25 ° C. or higher at 50 ° C. or having a melting point of 25 to 20
And a deterioration inhibitor which is a solid at 0 ° C. 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. Deterioration inhibitors are described in, for example,
Preferred examples include a basic compound having a pKa of 4 or more described in 194789. For example, first grade, second grade,
Tertiary amines and aromatic base compounds are preferred. Specific examples include tributylamine, trihexylamine, trioctylamine, dodecyl-dibutylamine, octadecyl-dimethylamine, tribenzylamine, diethylaminobenzene, and the like. And the compound A- described in (2)
1 to A-73 and B-1 to 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 of the present invention will be described. Specific examples of the ultraviolet absorber preferably used in the present invention include, for example, oxybenzophenone-based compounds, benzotriazole-based compounds, salicylate-based compounds, benzophenone-based compounds, cyanoacrylate-based compounds, nickel complex-based compounds, and the like. Specific examples of the benzotriazole-based ultraviolet absorber will be given, 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- (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'-te
(rt-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, 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. Also, 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, more preferably 0.05 to 3% by mass.

A retardation increasing agent for controlling the 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, and from 50 to 500 ppm.
ppm is more preferred. 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 is prepared.

Further, various additives may be added to the cellulose acylate solution at any stage after the preparation or before the preparation of the solution, if necessary. Examples of the additives include heat stabilizers such as inorganic fine particles and alkaline earth metal salts, antistatic agents, flame retardants, lubricants, and oils. In particular, the inorganic fine particles used have a role as an anti-smudge agent and have an antistatic property. In this case, the hardness of the metal or metal compound is not particularly limited, but the Mohs' hardness is preferably 1 to 10, more preferably 2 to 10. Organic fine particles are also preferably used, and examples thereof include cross-linked polystyrene, cross-linked polymethyl methacrylate, and cross-linked triazine resin. In particular, in the present invention, when the produced cellulose acylate film is handled,
In order to prevent scratching and deterioration of transportability,
It is common practice to add fine particles. Preferred specific examples of these matting agents include, as an inorganic compound, a compound containing silicon, silicon dioxide, titanium oxide, zinc oxide,
Aluminum oxide, barium oxide, zirconium oxide,
Strongium oxide, antimony oxide, tin oxide, tin / antimony oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate are preferred, and furthermore Preferred are inorganic compounds containing silicon and zirconium oxide. For example, Aerosil R972, R974, R812, 20
Commercial products having trade names such as 0, 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, 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 in the present invention 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. Compounds having two or more of ester, ketone and ether functional groups (i.e., -O-, -CO- and -COO-) can also be used as the main solvent. May be provided. 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 of the compound having any one of the functional groups. Examples of the esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate. 3 or more carbon atoms
Examples of twelve ketones include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and methylcyclohexanone. Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane,
Examples include 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-ethoxyethyl acetate,
Examples include methoxyethanol and 2-butoxyethanol.

Here, a description of cellulose acylate is given.
These main solvents have a preferred range of solubility parameters.
Can be shown. That is, the cellulose used in the present invention
Acylate has a solubility parameter of 17-22
Is shown. Books describing the solubility parameters
Although there are many, for example, Brandrup, E .; H's
Polymer Handbook (fourth e
description), VII / 671 to VII / 714.
It is listed. Among them, the cellulos used in the present invention
Organic solvents that can be used effectively for ose acylate include 19
~ 21MPa ^1/2Having a solubility parameter of
preferable. Solubility parameter is 19-21MPa^1/2
Examples of the organic solvent are methyl ethyl ketone (1
9), cyclohexanone (20.3), cyclopentano
(20.9), methyl acetate (19.6), 2-butoki
Siethanol (19.4), methylene chloride (20.
3), dioxane (19.6), 1,3-dioxolane
(19.8), acetone (20.3), ethyl formate (1
9.2), methyl acetoacetate (about 20)
Drofuran (19.4) and the like can be mentioned. This
Among them, methyl acetate, acetone, methyl acetoacetate,
Clopentanone, cyclohexanone, methylene chloride, etc.
Is most preferred. These are described in JP-A-9-955.
No. 38 publication. Further, JP-A-61-12
N-methylpyrrolidone described in JP-A-4470
A fluoroalcohol described in JP 11-60807 A,
1,3-dimene described in JP-A-112-63534
Chill 2-imidazolidinone is also used.

The solvent used for the above-mentioned cellulose acylate is selected from the above various viewpoints, but is preferably as follows. That is, a preferable solvent of the cellulose acylate used in the present invention is a mixed solvent of three or more different solvents, and the first solvent is selected from methyl acetate, ethyl acetate, methyl formate, ethyl formate, acetone, dioxolan, and dioxane. At least one 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 has 1 to 1 carbon atoms.
It is selected from 0 alcohols or hydrocarbons, and is more preferably an alcohol having 1 to 8 carbon atoms. 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 straight-chain, 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.

In the above three types of mixed solvents, 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), 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
/ 10/10/5, parts by mass), methyl acetate / cyclopentanone / methanol / ethanol (80/10/5 /
5, mass parts), methyl acetate / cyclopentanone / methanol / ethanol (80/10/5/5, mass parts), methyl acetate / cyclopentanone / acetone / methanol /
Ethanol (60/15/15/5/5, parts by mass), methyl acetate / cyclohexanone / methanol / hexane (70/20/5/5, parts by mass), methyl acetate / methyl ethyl ketone / acetone / methanol / ethanol (5 parts by mass)
0/20/20/5/5, 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 /
10/10/5/5/5, parts by mass), methyl formate / methyl ethyl ketone / acetone / methanol / ethanol (50/20/20/5/5, parts by mass), methyl formate /
Acetone / ethyl acetate / ethanol / butanol / hexane (65/10/10/5/5/5, parts by mass), acetone / methyl acetoacetate / methanol / ethanol (6
5/20/10/5, parts by mass), acetone / cyclopentanone / ethanol / butanol (65/20/10 /
5, parts by mass), acetone / 1,3 dioxolane / ethanol / butanol (65/20/10/5, parts by mass),
1,3 dioxolane / cyclohexanone / methyl ethyl ketone / methanol / butanol (55/20/10 /
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 / parts by mass)
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 /
15/5/5/5, parts by mass), and among them, methyl acetate / acetone / methanol / ethanol (75/15/5/5, parts by mass), methyl acetate / acetone / methanol / ethanol / Butanol (7
5/10/5/5/5, 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,
Parts by mass) are preferred.

The preparation of the cellulose acylate solution (dope) is not particularly limited, and may be carried out at room temperature, by a cooling dissolution method or a high temperature dissolution method, or by a combination thereof. These are described, for example, in JP-A-5-163301 and JP-A-61-10662.
No. 8, JP-A-58-127737, JP-A-9-955
No. 44, JP-A-10-95854, JP-A-10-45
950, JP-A-2000-53784, JP-A-11-
322946, JP-A-11-322947, JP-A-2-276830, JP-A-2000-273239,
JP-A-11-71463, JP-A-04-259511
JP-A-2000-273184, JP-A-11-32
No. 3017 and JP-A-11-302388, etc., describe a method 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.

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 dissolved by stirring and mixing in a dissolving pot or the like. 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. 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 10 to 30% by mass.

The preparation of the cellulose acylate solution (dope) is carried out according to the cooling dissolution method and will be 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 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 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 -30C, more preferably -10C).
(0 to -50C, most preferably -90 to -60C). 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, the cellulose acylate solution can be achieved by swelling and then 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 preferable to use a closed container in order to avoid water contamination due to condensation during cooling. In addition, in the cooling and heating operation, when 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.

The high-temperature dissolution method preferably used for preparing the cellulose acylate solution (dope) will be 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 of the present invention is added with cellulose acylate in a mixed organic solvent containing various solvents and swells in advance. 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 3 MPa.
It is heated to 60 to 240 ° C. under a pressure of 0 MPa (preferably 80 to 220 ° C., more preferably 100 to 200 ° C.).
° 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-
70/30 is preferable, and 10/90 to 60/40 is more preferable.
Is preferred.

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.

As described above, the concentration of the cellulose acylate solution is characterized in that a high-concentration dope can be obtained, and a cellulose acylate solution having a high concentration and excellent stability can be obtained without relying on concentration means. . After further dissolving at a low concentration to facilitate dissolution, the solution may be concentrated using a concentration means. The method of concentration is not particularly limited. A method of obtaining a high-concentration solution while evaporating the solvent by giving a difference (for example, Japanese Patent Application Laid-Open No.
No. 9511), 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. From U.S. Pat. No. 2,541,012, U.S. Pat.
SP 2,858,229, USP 4,414,3
No. 41, USP 4,504, 355, etc.).

It is preferable that the solution is filtered to remove foreign matters such as undissolved matter, dust, and impurities by using a suitable filter medium such as a wire mesh or flannel before casting. For filtration of the cellulose acylate solution, a filter having an absolute filtration accuracy of 0.1 to 100 μm is used.
It is preferable to use a filter of 25 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, the filtration pressure is 16 kgf / cm ² or less, and more preferably 12 kf / cm ^2.
It is preferable to filter at gf / cm ² or less, more preferably at 10 kgf / cm ² or less, particularly preferably at 2 kgf / cm ² or less. Filter media include glass fiber, cellulose fiber,
A conventionally known material such as a filter paper and a fluororesin such as a tetrafluoroethylene resin can be preferably used, and particularly, ceramics and metal are preferably used. The viscosity of the cellulose acylate solution immediately before film formation may be in a range that can be cast during film formation, and is usually 10 Pa · s to 2000 Pa.
.S, preferably 30 Pa · s
１０００1000 Pa · s is more preferable, and 40 Pa · s〜5
00 Pa · s is more preferred. 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 70C, more preferably -5 to 55C.

A method for producing a film using a cellulose acylate solution will be described. As a method and equipment for producing a cellulose acylate film, a solution casting film forming method and a solution casting film forming apparatus conventionally used for producing a cellulose triacetate film are 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. The dope is fed from the dope discharge port to a pressurized die through a pressurized metering gear pump that can perform high-precision quantitative liquid feeding, for example, by the number of rotations. At a peeling point where the metal support is evenly cast on the metal support and the metal support has substantially made a round, the freshly dried dope film (also referred to as 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 a cellulose acylate solution (dope) prepared is prepared 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-07-032391, JP-A-03-193316, and 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 single layer solution on a smooth band or a drum as a metal support, or a plurality of cellulose acylate solutions of 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 impart 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, but preferably the outer side has a total thickness of 1 to 1.
It is preferably 50%, more preferably 2 to 30%.
% Thickness. 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 core layer is preferably lower than the Tg of the skin layer.
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 by a method of uniformly extruding the prepared dope from a pressure die onto a metal support, and a method of using a dope once cast on the metal support by a blade. There is a method using a doctor blade for adjusting the film thickness by a method, a method using a reverse roll coater for adjusting with a roll rotating in the reverse direction, and the like, 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 also a method of positively stretching in the width direction. In the present invention, for example, JP-A-62-115035
JP-A-4-152125, JP-A-4-28421
No. 1, JP-A-4-298310, and JP-A-11-111
48271, etc. this is,
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 varies depending on the purpose of use, but is usually from 5 to 50.
The range is 0 μm, more preferably 20 to 300 μm, and most preferably 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 from 0.5 to 3 m, more preferably from 0.6 to 2.5 m, and still more preferably from 0.8 to 2.5 m.
2.2 m. Length is 100-100 per roll
It is preferable that the film is wound at a length of 500 m, more preferably 500 m
7000 m, more preferably 1000 to 60 m
00m. At the time of winding, it is preferable to impart knurling to at least one end, and the width is 3 mm to 50 mm, more preferably 5 m to 30 mm, and the height is 0.5 to 500 μ.
m, 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 is disclosed in JP-B-43-2603 and JP-B-43-260.
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 ozone-less 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 ). 25
In the case of low-pressure mercury lamp for a 4nm and dominant wavelength, 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 which is preferably used as a surface treatment for a cellulose acylate film will be specifically described. After immersing the surface of the cellulose acylate film in an alkaline solution, it is preferably 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.
~ 3.0N, preferably 0.5N ~ 2.0N
Is more preferable. 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, the cellulose acylate film is generally washed with water and then passed through an acidic aqueous solution, and then washed with water to obtain a surface-treated cellulose acylate film. At this time, the acid includes hydrochloric acid, nitric acid, sulfuric acid, acetic acid, formic acid, chloroacetic acid, oxalic acid, and the like, and its concentration is preferably 0.01 N to 3.0 N, and more preferably 0.05 N to 2.0 N. 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 adhesion between the film and the emulsion layer, a surface activation treatment is performed, and then a functional layer is directly applied on the cellulose acylate film 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 present invention is used for optical applications and photographic materials. 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, the 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. The surfactant used in the present invention may be either nonionic or ionic (anion, cation, betaine). 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 for optical applications, examples of the functional layer include an undercoat layer, an intermediate layer, an orientation control layer, a refractive index control layer, a protective layer, an antifouling layer, an adhesive layer, 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 is generally preferably 0.0001 to 5% by mass, more preferably 0.0005 to 5% by mass, based on the mass of the layer to be added. 2% by mass is preferred. In that case, the coating amount is preferably 0.02 to 1000 mg, and more preferably 0.05 to 200 mg per 1 m ² . Preferred nonionic surfactants are surfactants having a nonionic hydrophilic group of polyoxyethylene, polyoxypropylene, polyoxybutylene, polyglycidyl or sorbitan, and specifically, polyoxyethylene alkyl ether, polyoxyethylene Oxyethylene alkyl phenyl ether,
Polyoxyethylene-polyoxypropylene glycol, polyhydric alcohol fatty acid partial ester, polyoxyethylene polyhydric alcohol fatty acid partial ester, polyoxyethylene fatty acid ester, polyglycerin fatty acid ester, fatty acid diethanolamide, triethanolamine fatty acid partial ester Can be.

The anionic surfactants include carboxylate, sulfate, sulfonate and phosphate ester salts. Representative examples are fatty acid salt, alkylbenzene sulfonate, alkylnaphthalene sulfonate,
Alkyl sulfonate, α-olefin sulfonate, dialkyl sulfosuccinate, α-sulfonated fatty acid salt, N-methyl-N-oleyltaurine, petroleum sulfonate, alkyl sulfate, sulfated oil, polyoxyethylene 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 amine salts, quaternary ammonium salts, and pyridum salts. Primary to tertiary fatty amine salts, quaternary ammonium salts (tetraalkylammonium salts, trialkylbenzylammonium salts, Alkylpyridium salts, alkylimidazolium salts, etc.). Examples of the amphoteric surfactant include carboxybetaine and sulfobetaine, such as N-trialkyl-N-carboxymethylammonium betaine and N-trialkyl-N-sulfoalkyleneammonium betaine. 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, any of the layers above the cellulose acylate film may contain a slipping agent, in which 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 a C5 or more alkyl group, an alkylpolysiloxane having a polyoxyalkylene group in a side chain, an alkoxy, hydroxy, hydrogen, carboxyl, amino, mercapto group in a side chain And a modified polysiloxane such as an organopolysiloxane having a siloxane unit, and a block copolymer having a siloxane unit. Specific examples of such compounds are shown below, but are not limited thereto. Also,
Higher fatty acids and derivatives thereof, higher alcohols and derivatives thereof include higher fatty acids, metal salts of higher fatty acids, higher fatty acid esters, higher fatty acid amides, higher fatty acid polyhydric alcohol esters and the like, and higher fatty alcohols.
Monoalkyl phosphite of higher aliphatic alcohol,
A dialkyl phosphite, a trialkyl phosphite, a monoalkyl phosphate, a dialkyl phosphate, a trialkyl phosphate, a 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 scratching strength and free from repelling or the like on the undercoating 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 . 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 addition, there are many cases where it is preferable to reduce the static friction coefficient of the front and back of the film or the optical film,
The coefficient of static friction during this period is preferably 0.30 or less, more preferably 0.25 or less, and particularly preferably 0.13 or less. Also,
The dynamic friction coefficient is also preferably 0.30 or less, more preferably 0.25
Below, especially below 0.15 is preferred. Further, the coefficient of kinetic friction with the mating material to be contacted is preferably 0.3 or less, more preferably 0.25 or less, particularly preferably 0.15 or less. In many cases, it is preferable to reduce the dynamic friction coefficient between 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, and particularly preferably 0.13 or less.

In the functional layer of the cellulose acylate film, 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 preferably 0.005 to 10 μm, more preferably 0.01 to 5 μm.
The better the number of the projections on the surface, the better. A preferable projection is in a range having the average height of the projections, for example, when the projections are formed with a spherical or irregular matting agent, the content of the projections is 0.1.
5 to 600 mg / m ² , more preferably 1 to 4
00 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. The inorganic compound and the organic compound of the matting agent include, for example, barium sulfate, manganese colloid, titanium dioxide,
There are fine powders of inorganic substances such as strontium barium sulfate, silicon dioxide, aluminum oxide, tin oxide, zinc oxide, calcium carbonate, barium sulfate, talc, kaolin, and calcium sulfate, and further obtained by, for example, a wet method or gelling of silicic acid. And silicon dioxide (rutile type or anatase type) generated by titanium slag and sulfuric acid. Also, after pulverizing from an inorganic substance having a relatively large particle size, for example, 20 μm or more,
It can also be obtained by classification (vibration filtration, wind 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,
Alternatively, an inorganic compound can be used.

When used as an optical film or a protective film for a polarizing plate of the present invention, the polarizing plate 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 in the resin, and preferred conductive substances used in these include metal oxides and these. It is desirable to contain conductive fine particles composed of a composite oxide 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 include ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂
O ₃ , SiO ₂ , MgO, BaO, MoO ₂ , V ₂ O ₅
And the like, or a composite oxide of these is preferable.
O, TiO ₂ and SnO ₂ are preferred. Examples of containing heteroatoms include, for example, addition of Al and In to ZnO, addition of Nb and Ta to TiO ₂ , and addition of SnO.
_{For 2} , the addition of Sb, Nb, a halogen element or the like is effective. The addition amount of these hetero atoms is 0.01 to 25.
The range of mol% is preferable, but the range of 0.1 to 15 mol% is particularly preferable. Furthermore, organic electronic conductive organic compounds can also be used. For example, polythiophene, polypyrrole, polyaniline, polyacetylene, polyphosphazene, and the like. These are preferably used in a complex with polystyrene sulfonic acid, perchloric acid or the like as an acid donor.

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 cures 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. On the substrate surface, a high-refractive-index layer (which may be provided with a middle-refractive-index layer) and a low-refractive-index layer in the order of air are laminated in order. It is particularly preferable that the optical interference layer is formed by setting it to a certain value to form an anti-reflection layered product as the anti-reflection layer. The refractive index and the film thickness can be calculated by measuring the spectral reflectance. The optical film of the present invention may be subjected to a curl prevention process. What is anti-curl processing?
This function gives the function of rounding with the surface on which it is applied to the inside, but by performing this processing, one surface of the transparent resin film is subjected to some kind of surface treatment, and both surfaces have different degrees and types of surface When processing is performed, it functions to prevent curling with the 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 of 5 to 500 μm. The range is more preferably from 20 to 300 µm, and most preferably from 30 to 150 µm. In the present invention, the retardation Re in the in-plane direction of the cellulose acylate film formed as described above,
In particular, it is preferably less than 500 nm,
Is preferably less than 200 nm, more preferably less than 200 nm, still more preferably 100 nm or less, further preferably 50 nm or less, and 30 n
m is more preferable. It is particularly preferably 10 nm or less, and more preferably 5 nm. Further, the Rth of the cellulose acylate film of the invention is from 0 nm to 600 nm per 100 μm, and more preferably from 0 nm to 400 nm. Especially 0
It is preferably used in the range of nm to 250 nm. The angle θ (here, θ1) 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 is 0 °,
The closer to + 90 ° or −90 °, the more preferable. However, θ1 is a narrow angle between the film forming direction and the slow axis,
The range is from + 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 ratio 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 of 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-6-94915 instead of the alkali treatment
And an easy bonding process as described in JP-A-6-118232. 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 includes a polarizer and a protective film for protecting both surfaces of the polarizer, and further includes a protect film on one surface of the polarizer and a separate film on 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 present 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 Switching), FLC
(Ferroelectric Liquid Cry
stal), AFLC (Anti-ferroelec)
tric Liquid Crystal), OCB
(Optically Compensatory B
end), STN (Super Twisted N)
ematic), VA (Vertically Ali)
gned) and HAN (Hybrid Align)
Various display modes such as dNematic) 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 invention may be used as a support for an optical compensation sheet of a TN type liquid crystal display having a TN mode liquid crystal cell. TN mode liquid crystal cells and TN type liquid crystal display devices have been well known for a long time. Optical compensatory sheets used for TN type liquid crystal display devices are described in JP-A-3-9325, JP-A-6-148429 and JP-A-8-148429.
No. -50206 and JP-A-9-26572. Also, a paper by Mori et al. (Jpn. JA)
ppl. Phys. Vol. 36 (1997) p. 143 and Jpn. J. Appl. Phy
s. Vol. 36 (1997) p. 1068). 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 30
It is in the range of 0-1500 nm. An optical compensatory sheet used for an STN type liquid crystal display device is disclosed in JP-A-2000-1.
No. 05316.

The cellulose acylate film of the present invention
Is a VA type liquid crystal display device having a VA mode liquid crystal cell.
Particularly advantageously used as a support for optical compensatory sheets
You. Re of optical compensation sheet used for VA liquid crystal display device
When the retardation value is 0 to 150 nm, the Rth
It is preferable that the retardation value be 70 to 400 nm.
Good. Re retardation value is 20 to 70 nm
Is more preferable. Two pieces for VA type liquid crystal display
When using an optically anisotropic polymer film of
Rum's Rth retardation value is 70 to 250 nm
It is preferred that One light beam on VA liquid crystal display
When using an anisotropic polymer film,
Has an Rth retardation value of 150 to 400 nm.
Preferably, there is. VA type liquid crystal display devices are, for example,
As described in Kaihei 10-123576
Orientation-divided systems may be used. Cell of the present invention
Loose acylate film is an OCB mode liquid crystal cell
Of an OCB type liquid crystal display device having
Optical compensation sheet of HAN type liquid crystal display device having liquid crystal cell
It is also advantageously used as a support for the substrate. OCB type liquid crystal table
Compensation used for display devices or HAN type liquid crystal display devices
The sheet with the smallest absolute retardation
Direction does not exist in the plane of the optical compensation sheet or in the normal direction
Is preferred. OCB type liquid crystal display device or HAN
Properties of Optical Compensation Sheet Used for Liquid Crystal Display
The optical properties of the optically anisotropic layer and the optical properties of the support
And the arrangement of the optically anisotropic layer and the support
You. OCB type liquid crystal display device or HAN type liquid crystal display device
Japanese Patent Application Laid-Open No. 9-19 / 1990
No. 7397. Also, Mori
Other papers (Jpn. J. Appl. Phys. Vol. 38 (1999) p.2837)
There is a description.

The cellulose acylate film of the present invention
Are TN type, STN type, HAN type, GH (Guest-
An optical compensation sheet of a (Host) type reflection type liquid crystal display device;
It is also advantageously used. Are these display modes old?
Well-known. About TN type reflective liquid crystal display
Japanese Patent Application Laid-Open No. 10-123478, WO9884832
No. 0, and Japanese Patent No. 30222477,
is there. Optical Compensation Sheet Used for Reflective Liquid Crystal Display
Are described in WO00-65384. The present invention
Of cellulose acylate film of ASM (Axially
Symmetric Aligned Microcell) mode liquid crystal cell
Of the optical compensation sheet of the ASM type liquid crystal display device
It is also advantageously used. The ASM mode liquid crystal cell is
Cell thickness maintained by position adjustable resin spacers
There is a feature that has been. Other properties are TN mode
This is the same as that of the liquid crystal cell. ASM mode liquid crystal cell
For the ASM type liquid crystal display device, Kume et al.
Paper (Kume et al., SID 98 Digest 1089 (1998))
There is a description. The following describes the cellulose acylate of the present invention.
Specific embodiments are described, but are not limited thereto.
It is not something to be done.

[0070]

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 off of the film The surface of the support when the obtained film was peeled off from the support was visually observed, and the peeling 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 defects of the horizontal unevenness were 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 its 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) The haze of the film was measured using a haze meter (Model 1001DP, manufactured by Nippon Denshoku Industries Co., Ltd.).

Example 1 (1-1) Preparation of Cellulose Acylate Solution In a 100-L stainless steel dissolving tank having stirring blades, while well stirring and dispersing in the following solvent mixed solution, Table 1 was prepared.
The cellulose acylate powder (flakes) described in 1) was gradually added, and the whole was charged to 40 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 is charged into a dispersion tank, and the pressure in the tank is reduced to 1300 Pa.
/ Sec (shear stress 5 × 104 kgf / m / sec ² )
Disperser type eccentric stirring shaft with stirring at peripheral speed and anchor blades at the central axis, and dispersed for 30 minutes under conditions of stirring at a peripheral speed of 1 m / sec (shear stress 1 × 104 kgf / m / sec ² ) did. The onset temperature of the dispersion was 25 ° C., and the final temperature reached 48 ° 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. Until the swelling was completed, the pressure in the tank was increased to 0.12 MPa with nitrogen gas. 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. The amount of water in the dope is 0.1.
It was confirmed that the content was 2% by mass or less. The composition of the cellulose acylate solution is as follows.

Cellulose triacetate (substitution degree 2.8)
2, viscosity average degree of polymerization 320, water content 0.4 mass%, viscosity of 6 mass% in methylene chloride solution 305 mPa ·
s, average particle size 1.5 mm, standard deviation 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, plasticizer A (ditrimethylolpropanetetraacetate) 1.2 parts by mass , Plasticizer B
1.2 parts by mass of (triphenyl phosphate), UV agent a (2,4-bis- (n-octylthio) -6- (4-
Hydroxy-3,5-di-tert-butylanilino)-
0.2 parts by mass of 1,3,5-triazine), UV agent b (2
0.2 parts by mass of (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole, UV agent c (2 (2′-hydroxy-3 ′, 5′-di -Tert-amylphenyl) -5-chlorobenzotriazole) 0.2 parts by mass, fine particles (silicon dioxide (particle size 20)
nm), Mohs hardness about 7) 0.05 parts by mass, and a material of a polyvalent carboxylic acid derivative (described in Table 1) was used. The main solvent used herein, methyl acetate, has a solubility parameter of 19.6, and acetone used in combination has a solubility parameter of 20.3, which is a solvent within the preferred range of the present invention. Further, the cellulose triacetate used here has a residual acetic acid amount of 0.1% by mass or less,
a is 0.05% by mass, Mg is 0.007% by mass,
Further, Fe was 5 ppm. 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 was 0.08, the transparency was 93.5%, the Tg was 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 support temperature was 10 ° C. and the casting speed was 3 m /
The coating width was 70 cm in minutes. Drying was performed by blowing a drying air at 55 ° C. After 5 minutes, peel off from the mirror-finished stainless steel support.
60% by mass), and then at 110 ° C. for 10 minutes.
Further drying at 150 ° C for 30 minutes (film temperature is about 140
° C) and a cellulose triacetate film (film thickness 8
0 μm).

(1-4) Results Table 1 shows the evaluation results of the peeling characteristics and the film surface condition (unevenness, spots) obtained when the release agent of the present invention was used. Control sample 1 not using the release agent of the present invention 1
Sample No. 1 had remarkable peeling, and unevenness, spots, and haze were very poor. On the other hand, Sample 1 of the present invention
Samples Nos. 2 to 1-11 had no peeling, had no unevenness or irregularities, had a small haze, and had excellent surface properties. Further, Comparative Sample 1-12, which is a compound of the present invention but uses a small amount thereof, and Comparative Sample 1-13 which is a release agent of the present invention but uses a large amount thereof, has a large haze and transparency. It was inferior. In addition, Comparative Samples 1-14 to 1-17 using Comparative Compounds A, B, C and D, which are polyvalent carboxylic acids other than the present invention, had bad spots and could not satisfy haze.

[0080]

[Table 1]

Example 2 Sample 2-3 of the present invention 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-like solution was fed by a screw pump, and passed through a heated portion heated at 180 ° C. and 1 Mpa for 3 minutes. , 110 ° C, 1Mpa, 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 2-3 of the present invention obtained had good filterability, no peeling, and excellent nonuniformity, spots and haze.
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 3-3 of the present invention was prepared in exactly the same manner as in Example 1 except that both plasticizers A and B were removed as 0 parts by mass from Sample 1-3 of Example 1. did. The obtained sample 3-3 had no peeling and was uneven, and the spots were both A, and the haze was 0.3, which was excellent.
On the other hand, when the folding test was performed, Sample 1-3 was 10
Sample 3-3, which is within the scope of the present invention but without a plasticizer, was 82 times in the cut endurance test, which was no problem in practical use, but 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 by measuring a sample 120 mm × 120 mm at 23 ° C.
Humidity control at 65% RH for 2 hours, ISO 8776-198
According to No. 8, the number of reciprocations until cutting by bending was measured and evaluated.

Example 4 Sample 4-6 of the present invention was prepared in 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. Produced. The obtained sample 4-6 has no peeling, unevenness,
The spots were rated A, and the haze was 0.2, which was excellent. On the other hand, when the light-fading test was carried out for 1 month with a xenon lamp at 30,000 lux, Sample 1-3 had a haze of 0.3.
4%, which is within the scope of the present invention, but is not limited to Samples 4-6.
The haze increased slightly to 0.7. 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 5-7 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 1-7 of Example 1.
The obtained sample 5-7 had no peeling and unevenness and spots were evaluated as A, and the haze was 0.3, 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 5-7 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
In Example 10, a cellulose triacetate film of Sample 6-10 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 in Example 1 was changed as follows. That is, (1
A part of the cellulose triacetate solution obtained in -1) 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 layered and co-cast with the cellulose triacetate solution of sample 1-3 and on both sides thereof. Thus, a co-cast cellulose triacetate film was obtained. The film thickness is 3 μm on both sides and 34 μm on the inside, and the total thickness is 4 μm.
The thickness was set to 0 μm. The surface state of the obtained sample 6-10 was smoother than that of the sample 1-3, and was more excellent without irregularities. Therefore, it is clear that co-casting is a more excellent aspect in the present invention.

[Example 7] In Example 1 of JP-A-11-316378, the first transparent support was replaced with a cellulose triacetate film (second film) obtained from Sample 1-3 of Example 1 of the present invention. Except that the thickness was changed to 100 μm.
The sample 7-3 was obtained by performing Example 1 of JP-316378A.
Was prepared. 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
Fuji Photo Film Co., Ltd. of Example 1 of 33433
Except that the cellulose triacetate produced was changed to the cellulose triacetate film of Sample 1-3 of the present invention,
An optical compensation filter film sample was prepared in exactly the same manner as in Example 1 of JP-A-7-333433. 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.

Embodiment 9 In the present invention, a sample 11 which is used for a variety of optical applications and which is a representative of the present invention is described in, for example, the liquid crystal display device described in Embodiment 1 of JP-A-10-48420. Japanese Patent Application Laid-Open No. 9-26572 discloses an optically anisotropic layer containing discotic liquid crystal molecules described in Example 1 and an alignment film coated with polyvinyl alcohol.
VA-type liquid crystal display device described in FIGS. 2 to 9 of 00-154261, and FIG. 1 of JP-A-2000-154261.
When used for the OCB type liquid crystal display devices described in Nos. 0 to 15, good performance was obtained.

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. The first layer and the second layer (back layer composition) of Example 1 of JP-A-4-73736 were applied to one of the obtained films, and a back layer having a cationic polymer as a conductive layer was prepared. . Furthermore, on the opposite side of the film base having the obtained back layer,
Sample 105 of Example 1 in JP-A-11-38568
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.

[0092]

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.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29L 7:00 B29L 7:00 C08L 1:10 C08L 1:10 F term (Reference) 2H023 FA00 2H049 BA02 BA04 BA06 BA42 BB12 BB33 BB49 BC09 BC22 4F071 AA09 AA81 AE04 AE05 AE10 AE17 AE19 AH19 BA02 BB02 BC02 BC12 4F205 AA01 AB07 AB10 AB11 AB14 AC05 AG01 GA07 GB02 GC07 GE22 GE24

Claims (25)

[Claims] 1. A cellulose acylate having a degree of substitution of cellulose with a hydroxyl group that satisfies all of the following formulas (I) to (III) is dissolved in an organic solvent.
a, 25 ° C.) is a polycarboxylic acid derivative having at least one carboxyl group having 4.4 or less or a salt thereof.
Cellulose acylate film prepared from a cellulose acylate solution containing 002 to 2% by mass: (I) 2.6 ≦ SA + SB ≦ 3.0 (II) 2.0 ≦ SA ≦ 3.0 (III) 0 ≦ SB ≦ 0.8 [wherein, SA and SB represent a substituent of an acyl group substituted by a hydroxyl group of cellulose, SA is a degree of substitution of an acetyl group, and SB is a substitution of an acyl group having 3 to 22 carbon atoms. Degrees.] 2. SA and S at the 6-position of cellulose acylate
The cellulose acylate film according to claim 1, wherein the total of the degree of substitution of B is 0.8 or more. 3. The sum of the degree of substitution of SA and SB is 2.80 to 3.80.
2.95, the degree of substitution of SB is 0 to 0.8,
The cellulose acylate film according to claim 1, wherein 30% or more of B is present as a substituent of a hydroxyl group at the 6-position, and the sum of the degrees of substitution of SA and SB at the 6-position is 0.85 or more. 4. The acyl group of SB is propionyl, butyryl, heptanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, isobutanoyl, t-butanoyl, cyclohexanoylbonyl, 2. The cellulose acylate film according to claim 1, which is oleoyl, benzoyl, naphthoyl or cinnamoyl. 5. A cellulose acylate having a content of 250 to 55.
The cellulose acylate film according to claim 1, which has a viscosity average degree of polymerization of 0. 6. The polyvalent carboxylic acid derivative is a hydrocarbon-based polycarboxylic acid ester having at least one carboxyl group or a salt thereof, a hydrocarbon-based polycarboxylic acid amide, an aromatic-based polycarboxylic acid ester, or an aromatic polycarboxylic acid ester. The cellulose acylate film according to claim 1, which is a polycarboxylic acid amide or a heterocyclic polycarboxylic acid amide. 7. A hydrocarbon polycarboxylic acid ester, a hydrocarbon polycarboxylic acid amide, an aromatic polycarboxylic acid ester, an aromatic polycarboxylic acid amide or a heterocyclic polycarboxylic acid, The cellulose acylate film according to claim 6, further comprising a (poly) oxyalkylene group. 8. The (poly) oxyalkylene group is a poly (oxyethylene) group, a (poly) oxypropylene group,
The cellulose acylate film according to claim 7, which is a (poly) oxybutylene group or a (poly) oxyglycerin group. 9. An organic solvent comprising an ether having 3 to 12 carbon atoms, a ketone having 3 to 12 carbon atoms and 3 carbon atoms.
The cellulose acylate film according to claim 1, which is a non-chlorinated organic solvent selected from the group consisting of esters of Nos. 1 to 12. 10. An ether having 3 to 12 carbon atoms is diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxane,
Selected from 1,3-dioxolane, tetrahydrofuran, anisole and phenetole, having 3 to 12 carbon atoms
Is selected from acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and methylcyclohexanone, and has 3 to 3 carbon atoms.
10. The cellulose acylate film according to claim 9, wherein the 12 esters are selected from ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, propyl acetate and pentyl acetate. 11. The organic solvent is a mixed solvent 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. Wherein the second solvent is selected from the group consisting of ketones and acetoacetates having 4 to 7 carbon atoms, and the third solvent is selected from the group consisting of alcohols and hydrocarbons having 1 to 10 carbon atoms. Item 6. The cellulose acylate film according to Item 1. 12. The method according to claim 1, wherein the first solvent is 20 to 90% by mass,
5 to 60% by mass of a third solvent and 5 to 30% by mass of a third solvent
The cellulose acylate film according to claim 11, which is contained at a ratio of: 13. The organic solvent is a mixed solvent of three or more different solvents, wherein the first solvent and the second solvent are methyl acetate, ethyl acetate, methyl formate, ethyl formate, acetone, dioxolan and dioxane. The cellulose acylate film according to claim 1, wherein the third solvent is selected from the group consisting of alcohols and hydrocarbons having 1 to 10 carbon atoms. 14. The method according to claim 14, wherein the first solvent is 20 to 90% by mass,
5 to 60% by mass of a third solvent and 5 to 30% by mass of a third solvent
The cellulose acylate film according to claim 13, which is contained at a ratio of: 15. The cellulose acylate film according to claim 1, wherein the organic solvent is methylene chloride. 16. The cellulose acylate film according to claim 1, wherein the cellulose acylate is dissolved at a concentration of 10 to 40% by mass. 17. A cellulose acylate solution containing a mixture of cellulose acylate and an organic solvent at -10 to 40 ° C.
The cellulose acylate film according to claim 1, wherein the cellulose acylate film is prepared by a step of swelling with an organic solvent and a step of heating the swelled mixture to 0 to 57 ° C to dissolve cellulose acylate in an organic solvent. 18. A cellulose acylate solution containing a mixture of cellulose acylate and an organic solvent at -10 to 55 ° C.
Swelling, cooling the swelled mixture to −100 to −10 ° C., and heating the cooled mixture to 0 to 57 ° C. to dissolve the cellulose acylate in the organic solvent. Item 10. The cellulose acylate film according to Item 1. 19. A cellulose acylate solution containing a mixture of cellulose acylate and an organic solvent at -10 to 55 ° C.
And swelling the mixture with 0.2 to 30 MPa at 6
The cellulose acylate according to claim 1, wherein the cellulose acylate is prepared by a step of heating the mixture to a temperature of 0 to 240 ° C under a high pressure and a high temperature, and a step of cooling the heated mixture to a temperature of 0 to 57 ° C to dissolve the cellulose acylate in an organic solvent. Film. 20. When mixing cellulose acylate and an organic solvent, particles of 0.1 to 5 mm in which 90% by mass or more of cellulose acylate are used, and the obtained cellulose acylate solution is filtered. 20. The cellulose acylate film according to any one of 17 to 19. 21. A method comprising: casting a cellulose acylate solution on a support; stripping the solution; drying the solvent by evaporating the solvent to form a film; and winding the dried film. 2. The cellulose acylate film according to 1. 22. The cellulose acylate film according to claim 21, wherein two or more kinds of cellulose acylate solutions are co-cast in the casting step. 23. The cellulose acylate solution contains a plasticizer in an amount of 0.1 to 20% by mass based on the cellulose acylate or an ultraviolet absorber in an amount of 0.001 to 5% by mass based on the cellulose acylate. The fine particle powder is contained in an amount of 0.001 to 5% by mass with respect to the cellulose acylate, or the fluorine-based surfactant is contained in the amount of 0.001 to 2% by mass with respect to the cellulose acylate. The cellulose acylate film according to claim 1. 24. The cellulose acylate film according to claim 1, which is for an optical material protective layer and has a thickness of 10 to 200 μm. 25. The cellulose acylate film according to claim 1, which is used for a silver halide photographic light-sensitive material support and has a thickness of 30 to 250 μm.