JP2003055476A - Cellulose acylate film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a cellulose acylate film that can be peeled off from a substrate in the producing process by preparing a solution in which a cellulose acylate is dissolved in an organic solvent in a stable state and provide an excellent cellulose acylate film that has a good surface condition by the use of the solution. SOLUTION: The cellulose acylate film is formed from a cellulose acylate solution in which a cellulose acylate is dissolved in an amount of 15-30 wt.% in an organic solvent wherein the cellulose acylate has an aggregate molecular weight of 4,000,000-10,000,000 (at 25 deg.C) in a dilute solution prepared by diluting the cellulose acylate solution with an organic solvent having a composition the same as the above-described organic solvent used in dissolving the cellulose acylate so that the content of the cellulose acylate is adjusted to an amount of 0.1-1 wt.%.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a cellulose acylate film useful for a silver halide photographic light-sensitive material or a liquid crystal image display device.

[0002]

2. Description of the Related Art Conventionally, an organic solvent of a cellulose acylate solution used for producing a cellulose acylate used for a silver halide photographic light-sensitive material or a liquid crystal image display device is a chlorine-containing carbonic acid such as methylene chloride. Hydrogen is used. Methylene chloride (boiling point 40 ° C)
Conventionally, it has been 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 manufacturing process and is easily dried. On the other hand, methylene chloride has a low boiling point and is easily volatilized, so even if it is closed equipment, it may leak slightly in the handling process and there is a limit to recovery, and there is a problem that it is not possible to completely prevent the dispersion into the atmosphere. Improvements are desired in this respect. Therefore, in order to solve this problem, using methylene chloride, it was studied to prepare a higher concentration cellulose acylate solution to reduce the amount of the solvent used, but the peeling from the metal support during casting was insufficient. The improvement was desired. Furthermore, the search for a solvent for cellulose acylate other than methylene chloride has been made. Known as organic solvents exhibiting solubility in cellulose acylate, particularly cellulose triester, are acetone (boiling point 56 ° C.), methyl acetate (boiling point 56 ° C.), tetrahydrofuran (boiling point 65 ° C.), 1,3-dioxolane ( Boiling point 75 ° C.), 1,4-dioxane (boiling point 101 ° C.) and the like. However, these organic solvents have not been sufficiently soluble by the conventional dissolution method to be practically usable.

As a solution to this problem, J. M. G. Cowie
Et al., Makromol. chem. 143, page 105 (1971), cellulose triacetate (acetylation degree 60.1% to 61.3%) in acetone at -80 ° C.
To -70 ° C. and then warmed to 0.
It is reported that a dilute solution of 5 to 5 mass% is obtained. A method of dissolving cellulose acylate at such a low temperature is called a cooling dissolution method. In addition, Kenji Uede et al. Describes spinning technology using a cooling dissolution method in "Dry spinning from acetone solution of cellulose triacetate" in Textile Machinery Society, Vol. 34, pp. 57-61 (1981). There is.

Further, in JP-A-9-95538, JP-A-9-95544 and JP-A-9-95557,
Against the background of the above technique, it is disclosed that cellulose acylate is dissolved by a cooling dissolution method using a non-chlorine organic solvent. The non-chlorine organic solvent used at that time is an organic solvent selected from ethers, ketones or esters, and in particular, a cellulose acylate is dissolved by a cooling dissolution method to produce a film. Acetone, 2-methoxyethyl acetate, cyclohexanone, ethyl formate, methyl acetate, etc. are preferred as these specific organic solvents.

On the other hand, the cellulose acylate film is
Generally, it is manufactured by a solvent cast method or a melt cast method. In the solvent cast 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 practice. In the recent solvent cast method, the problem is to improve the productivity of the film-forming process by shortening the time required from casting the dope onto the support to peeling the molding film on the support. Has become. In particular, when a cellulose acylate film is obtained by the solvent cast method, it is difficult to peel the cellulose acylate film from its support when the cellulose acylate solution is cooled and dissolved using the above-mentioned non-chlorine organic solvent. Is a problem. Furthermore, it is required to increase productivity in response to the recent increase in demand for cellulose acylate film, and therefore high-speed casting is earnestly desired. From this viewpoint as well, the cellulose acylate film produced by the solution using a non-chlorine organic solvent was inferior in the high-speed casting property.

In this method, cellulose acylate is cast on a band or a drum, which is a metal support, and dried or cooled to give a gel film having high strength. The gel film is peeled from the support while containing an organic solvent. This is because it is difficult to peel the cellulose acylate film from the support during the subsequent step of being sufficiently dried. The chlorine-based organic solvent of methylene chloride was also found and the improvement thereof was desired as described above, but the non-chlorine-based organic solvent was more difficult to peel off, and the improvement thereof was desired. On the other hand, it is also possible to use high temperature and high pressure as a method for dissolving the cellulose acylate in a non-chlorine organic solvent, which is a useful means. However, the cellulose acylate solution produced by this method is not sufficiently peeled off from the cast metal support during its production, and its improvement has been desired. To solve this problem, in JP-A-10-316701, the acid dissociation index pKa is 1.93 to 4.50 [preferably 2.0 to 4.4, more preferably 2.2 to 4.3 (for example, , 2.5-4.
0), especially 2.6-4.3 (eg 2.6-4.0).
Acid] or a salt thereof is preferred as a stripping agent. However, as a drawback, it causes a problem that a fine salt is formed with the alkaline earth metal contained in the cellulose acylate in the cellulose acylate solution and adheres to the system in a long casting process. There was a hope for its improvement. Although some solutions have been shown to significantly improve stripping with these strippers, they have been unsatisfactory.

[0007]

Therefore, when preparing a solution of cellulose acylate in an organic solvent, particularly a non-chlorine organic solvent, it is possible to solve the problem that peeling from the support is difficult due to drying after casting. Excellent surface cellulose acylate
To make a film. The object of the present invention is to dissolve a cellulose acylate solution prepared by a room temperature dissolution, a cooling dissolution method or a high temperature high pressure dissolution method using a chlorine-based organic solvent, more preferably a non-chlorine-based organic solvent, to obtain an excellent surface cellulose. It is to provide a cellulose film. Further, it is an object of the present invention to easily peel the film from the support for the purpose of drying after casting and imparting excellent productivity.

[0008]

The objects of the present invention have been achieved by the following cellulose acylate films (1) to (8). (1) A cellulose acylate solution in which 15 to 30% by mass of cellulose acylate is dissolved in an organic solvent,
The molecular weight of the aggregate of cellulose acylate in the diluted solution prepared by adjusting the solution to 0.1 to 1% by mass with an organic solvent having the same composition is 4
A cellulose acylate film produced from a cellulose acylate solution having a viscosity of 1,000,000 to 10,000,000 (25 ° C).

(2) The cellulose according to (1), wherein the cellulose acylate is a cellulose acylate whose degree of substitution of the hydroxyl group of cellulose satisfies all of the following formulas (I) to (III). Acylate film: (I) 2.6 ≦ SA + SB ≦ 3.0 (II) 2.0 ≦ SA ≦ 3.0 (III) 0 ≦ SB ≦ 0.8 [wherein SA and SB are hydroxyl groups of cellulose] Represents the substituent of the acyl group substituted by; SA represents the degree of substitution of the acetyl group; and SB represents the number of carbon atoms of 3 to 22.
Represents the substitution degree of the acyl group]. (3) The organic solvent is a non-chlorine organic solvent selected from ethers having 3 to 12 carbon atoms, ketones having 3 to 12 carbon atoms, and esters having 3 to 12 carbon atoms. The cellulose acylate film according to (1), which is at least one kind of solvent.

(4) A cellulose acylate solution according to (1), wherein the cellulose acylate solution is obtained by at least one of the following preparation methods (IV) to (VI): (IV) at -10 to 55 ° C. Swelling step, the mixture 0
Method for preparing cellulose acetate solution comprising heating cellulose acetate to 57 ° C to dissolve cellulose acetate in organic solvent (V) Swelling at -10 to 55 ° C, -100 to -1
Cooling to 0 ° C., and cooling the cooled mixture from 0 to 57
Method for preparing a cellulose acetate solution comprising the step of heating cellulose acetate in an organic solvent by heating to (VI) -swelling at -10 to 55 ° C, 0.2 to 30M
A preparation method comprising the steps of heating at 60 to 240 ° C. at high pressure and high temperature in Pa, and cooling the heated mixture to 0 to 57 ° C. to dissolve cellulose acetate in an organic solvent. (5) A step of filtering the obtained cellulose acylate solution by using particles having a particle diameter of 0.1 to 5 mm in 90% by mass or more of the cellulose acylate when mixing the cellulose acylate and the organic solvent. , A step of casting a cellulose acylate solution on a support, a step of peeling, a drying step of evaporating a solvent to form a film, and a step of winding the prepared cellulose acylate film (1) The cellulose acylate film described in 1.

(6) The cellulose acylate solution is a cellulose acylate solution containing at least one plasticizer in an amount of 0.1 to 20 mass% with respect to the cellulose acylate, and / or at least one ultraviolet ray. It is a cellulose acylate solution containing 0.001 to 5 mass% of an absorbent with respect to cellulose acylate, and / or at least one kind of fine particle powder is 0.001 to 5 mass% with respect to cellulose acylate. %, And / or a cellulose acylate solution containing at least one fluorosurfactant in an amount of 0.001 to 2% by mass based on the cellulose acylate, And / or at least one releasing agent is added to the cellulose acylate in an amount of 0.00
It is a cellulose acylate solution containing 0 to 1% by mass, and / or at least one deterioration inhibitor is 0.0001 to 2% by mass with respect to the cellulose acylate.
It is a cellulose acylate solution containing and / or a cellulose acylate solution containing at least one optical anisotropy controlling agent in an amount of 0.1 to 15% by mass based on the cellulose acylate. A cellulose acylate film as described in (1) above.

(7) The cellulose acylate film according to (1), wherein two or more kinds of cellulose acylate solutions are co-cast in the casting step. (8) The produced cellulose acylate film is a cellulose acylate film used as an optical protective layer and has a film thickness of 10 to 500 μm, or the produced cellulose acylate film is a silver halide. It is used as a support for a photographic light-sensitive material and has a film thickness of 30 to 250 μm (1)
The cellulose acylate film described in 1.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION First, the cellulose acylate preferably used in the present invention will be described in detail. Cellulose acylate is not particularly limited as long as it exhibits the effects of the present invention. However, among them, preferable cellulose acylates include the following materials. That is, the cellulose acylate is a cellulose acylate whose degree of substitution of the hydroxyl group of cellulose satisfies all of the following formulas (I) to (III). (I) 2.6 ≦ SA + SB ≦ 3.0 (II) 2.0 ≦ SA ≦ 3.0 (III) 0 ≦ SB ≦ 0.8 where SA and SB are substituted with a hydroxyl group of cellulose. Represents the substituent of the acyl group, SA represents the substitution degree of the acetyl group, and SB represents the number of carbon atoms.
It is the substitution degree of the acyl group of 22.

The β-1,4-bonded glucose unit constituting cellulose has a free hydroxyl group at the 2-position, 3-position and 6-position. Cellulose acylate is a polymer obtained by esterifying some or all of these hydroxyl groups with an acyl group. The degree of acyl substitution is 2
For each of the 3rd, 6th, and 6th positions, the ratio of esterification of cellulose (100% esterification means a substitution degree of 1) is meant. In the present invention, the sum of the substitution degrees 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, and particularly 0 to 0.6. Further, 28% or more of SB is a substituent of the 6-position hydroxyl group, more preferably 30% or more is a substituent of the 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, a cellulose acylate film having a total substitution degree of SA and SB at the 6-position of cellulose acylate of 0.8 or more, further 0.85, and particularly 0.90 can be mentioned. By using these cellulose acylate films, a solution having a preferable solubility can be prepared, and particularly in a non-chlorine organic solvent, a good solution can be prepared.

Acyl group having 3 to 22 carbon atoms (SB)
Is not particularly limited, and may be an aliphatic group or an allyl group. They are, for example, cellulose alkyl carbonyl ester, alkenyl carbonyl ester, aromatic carbonyl ester, aromatic alkyl carbonyl ester and the like, which may each have a further substituted group. Preferred SBs are propionyl, butanoyl, keptanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, iso-butanoyl, t-butanoyl, cyclohexanecarbonyl, oleoyl, benzoyl. , Naphthylcarbonyl, cinnamoyl group and the like. Among these, propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, oleoyl, benzoyl, naphthylcarbonyl, cinnamoyl and the like.

The basic principle of the method for synthesizing cellulose acylate is described in Ueda et al., Wood Chemistry, pages 180-190 (Kyoritsu Shuppan, 1968). A typical synthesis method is a liquid phase acetylation method using a carboxylic acid anhydride-acetic acid-sulfuric acid catalyst. Specifically, after pre-treating a cellulose raw material such as cotton linter or wood pulp with an appropriate amount of acetic acid, the mixture is put into a pre-cooled carboxylic oxidation mixed solution to be esterified to obtain a complete cellulose acylate (2nd, 3rd and 6th). The total degree of acyl substitution at positions is about 3.00). The above-mentioned carboxylic oxidation mixed liquid generally contains acetic acid as a solvent, carboxylic acid anhydride as an esterifying agent, and sulfuric acid as a catalyst. Carboxylic anhydride is usually used in a stoichiometric excess over the total of the cellulose that reacts with it and the water present in the system. After 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. Aqueous solution of carbonate, acetate or oxide). Next, the obtained complete cellulose acylate is saponified and aged by keeping it 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 is completely neutralized with the neutralizing agent as described above, or it is added to water or diluted sulfuric acid without neutralization. Add the cellulose acylate solution (or, in 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 treatment.

In the cellulose acylate film of the present invention, it is preferable that the polymer component constituting the film is substantially composed of cellulose acylate having the above definition. "Substantially" means 55% by mass or more (preferably 70% by mass or more, more preferably 80% by mass) of the polymer component.
Mass% or more). Cellulose acylate particles are preferably used as a raw material for film production. 90% by mass or more of the particles used are 0.5 to 5 mm
It is preferable to have a particle size of. 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 a spherical shape as possible.

The degree of polymerization of the cellulose acylate preferably used in the present invention is such that the viscosity average degree of polymerization is 200 to 700,
Preferably 250 to 550, more preferably 250 to 4
00, particularly preferably a viscosity average degree of polymerization of 250 to 3
50. The average degree of polymerization is determined by the limiting viscosity method of Uda et al. (Kazuo Uda, Hideo Saito, Journal of the Fiber Society, Vol. 18, No. 1, 105
~ 120, 1962). Further, it is described in detail in JP-A-9-95538.

When the low-molecular component is removed, the average molecular weight (degree of polymerization) increases, but the viscosity becomes 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 a usual method. The removal of low molecular components can be carried out by washing the cellulose acylate with a suitable organic solvent. In the case of producing cellulose citrate containing a small amount of low-molecular components, it is preferable to adjust the amount of the sulfuric acid catalyst in the acetylation reaction to 0.5 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, it is possible to synthesize a cellulose acylate which is preferable in terms of molecular weight distribution (uniform molecular weight distribution).

The water content of cellulose acylate is preferably 2% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.7% by mass or less. Generally, cellulose acylate contains water and is known to be 2.5 to 5 mass%. In the present invention, in order to adjust the water content of the cellulose acylate,
It is necessary to dry the cellulose acylate, and the method is not particularly limited as long as the desired water content is obtained.
In the cellulose acylate used in the present invention, the raw material cotton and its synthesis method are described in JIII Journal of Technical Disclosure (Kogi No. 2001).
-1745, published by Mar. 15, 2001, Institute of Invention, pp. 7-12.

In the cellulose acylate solution, various additives (for example, a plasticizer, an anti-UV agent, an anti-degradation agent, an optical anisotropy control agent, fine particles, a release agent, etc.) depending on the application are used in each preparation step. Can be added. Further, the addition may be carried out at any time in the dope preparation process, but may be carried out by adding a process of adding an additive to the final preparation process of the dope preparation process. For details, refer to the Technical Bulletin published by JIII
1745, Issued March 15, 2001, Institute of Invention) 1
The materials described in detail on pages 6 to 22 are preferably used.

Next, the organic solvent used when 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 purpose can be achieved within the range capable of forming a film. First, as the chlorine-based solvent, methylene chloride and chloroform are preferable, and methylene chloride is particularly preferable. In the present invention, the non-chlorine organic solvent particularly preferably used as the organic solvent is
A solvent selected from esters, ketones and ethers having 3 to 12 carbon atoms is preferable. The ester, ketone, and ether may have a cyclic structure. ester,
Functional groups of ketones and ethers (ie, -O-,
A compound having two or more of any one of -CO- and -COO- can also be used as a main solvent and may have another functional group such as an alcoholic hydroxyl group. In the case of a main solvent having two or more kinds of functional groups, the number of carbon atoms may be within the specified range of the compound having any functional group. Examples of esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate. Examples of ketones having 3 to 12 carbon atoms include acetone,
Mention may be made of methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and methylcyclohexanone. 3 to 1 carbon atoms
Examples of 2 ethers include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole. Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol.

The solvent used for the above cellulose acylate is selected from the various viewpoints described above, but is preferably as follows. That is, a preferable solvent of cellulose acylate is a mixed solvent of three or more different kinds, and the first solvent is at least one selected from methyl acetate, ethyl acetate, methyl formate, ethyl formate, acetone, dioxolane, dioxane or Alternatively, it is a mixed solution thereof, the second solvent is selected from ketones or acetoacetic acid esters having 4 to 7 carbon atoms, and the third solvent is selected from alcohol or hydrocarbon having 1 to 10 carbon atoms. , And more preferably 1 to 1 carbon atoms
8 alcohol. When the first solvent is a mixed solution of two or more kinds of solvents, the second solvent may be omitted. 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, methyl acetyl acetate, and a mixed solution thereof. May be

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

The above-mentioned three kinds of mixed solvents should contain the first solvent in an amount of 20 to 95% by mass, the second solvent in an amount of 2 to 60% by mass, and the third solvent in an amount of 2 to 30% by mass. Is preferred, and further the first solvent is 30 to 90 mass%,
It is preferable that the second solvent is contained in an amount of 3 to 50% by mass and the third alcohol is contained in an amount of 3 to 25% by mass. Moreover, especially the 1st solvent is 30-90 mass%, and the 2nd solvent is 3-.
It is preferable that the content of the third solvent is 30% by mass, and the third solvent is alcohol, and the content is 3 to 15% by mass. Note that when the first solvent is a mixed liquid and the second solvent is not used, the first solvent is 20 to
90% by mass, the third solvent is preferably contained in a ratio of 5 to 30% by mass, further, the first solvent is 30 to 86% by mass, and the third solvent is further contained in 7 to 25% by mass. It is preferable. The non-chlorine-based organic solvent used in the present invention is described in more detail on pages 12 to 16 of the Invention Technical Disclosure Technical Report (Kogi Gi No. 2001-1745, published on March 15, 2001, Invention Technical Association). It is described in. In the present invention, preferable combinations of organic solvents can be mentioned below, but the invention is not limited thereto.

Examples of preferable organic solvent combinations include:
Methyl acetate / acetone / methanol / ethanol / butanol (75/10/5/5/5, mass part), methyl acetate / acetone / methanol / ethanol / propanol (75/10/5/5/5, mass part), Methyl acetate / acetone / methanol / butanol / cyclohexane (7
5/10/5/5/5, parts by mass), methyl acetate / methyl ethyl ketone / methanol / butanol (80/10 /
5/5, parts by mass), methyl acetate / acetone / methyl ethyl ketone / ethanol / isopropanol (75/10
/ 10/5/7, parts by mass), methyl acetate / cyclopentanone / methanol / isopropanol (80/10/5)
/ 8, mass part), methyl acetate / cyclopentanone / methanol / isobutanol (80/10/5/7, mass part), methyl acetate / cyclopentanone / acetone / methanol / butanol (60/15/15 / 5/6, mass part), methyl acetate / cyclohexanone / methanol / hexane (70/20/5/5, mass part), methyl acetate /
Methyl ethyl ketone / acetone / methanol / ethanol (50/20/20/5/5, parts by mass), methyl acetate / 1,3 dioxolane / methanol / ethanol (70
/ 20/5/5, parts by mass), methyl acetate / dioxane /
Acetone / methanol / ethanol (60/20/10
/ 5/5, mass part), methyl acetate / acetone / cyclopentanone / ethanol / isobutanol / cyclohexane (65/10/10/5/5/5, mass part), methyl formate / methyl ethyl ketone / acetone / methanol / Ethanol (50/20/20/5/5, mass part), methyl formate / acetone / ethyl acetate / ethanol / butanol / hexane (65/10/10/5/5/5, mass part), acetone / acetoacetic acid Methyl / methanol / ethanol (65/20/10/5, parts by mass), acetone /
Cyclopentanone / Ethanol / Butanol (65/2
0/10/5, 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 (55/2
0/10/5/5/5, parts by mass), acetone / methylene chloride / methanol (85/5/5, parts by mass), methyl acetate / methylene chloride / methanol / ethanol (70/1
0/15/5, parts by mass), 1,3-dioxolane / methylene chloride / methanol / butanol (70/15/10
/ 5, parts by mass), 1,4-dioxane / methylene chloride /
Acetone / methanol / butanol (70/5/15 /
5/5, parts by mass), cyclohexanone / methylene chloride /
Acetone / methanol / ethanol / isopropanol (60/10/15/5/5/5, parts by mass) and the like can be mentioned. In addition to the above organic solvent, methylene chloride may be contained in the dope in an amount of 10% by mass or less based on the total amount of the organic solvent.

Further, in the present invention, a methylene chloride type can be used as the chlorine type organic solvent. The following solvent compositions are preferable. However, from the viewpoint of environmental safety, it is preferable to use a combination of the above-mentioned chlorine-free organic solvents. Moreover, it is preferable to carry out the dissolution with a chlorine-based organic solvent by a cooling dissolution method. Examples of the methylene chloride-based solvent composition include methylene chloride / methanol / butanol (80/18/3, mass part), methylene chloride / methanol / isopropanol (80/18/5, mass part),
Methylene chloride / acetone / methanol / ethanol / isopropanol (70/10/15/5/10, parts by mass), methylene chloride / acetone / methyl ethyl ketone /
Methanol / Butanol / Isopropanol (60/1
0/5/5/5/5, parts by mass).

In order to control the associated molecular weight of cellulose acylate, it is effective to add a poor solvent for cellulose acylate (eg, alcohol, hydrocarbon) and adjust the amount thereof. Preferred alcohols are methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol and cyclohexanol.
Preferred hydrocarbons are hexane and cyclohexane.

The dope used in the present invention is characterized in that the cellulose acylate is dissolved in an organic solvent in an amount of 15 to 30% by mass, more preferably 17 to 27% by mass,
It is particularly preferable that 18 to 25% by mass is dissolved.
The method of adjusting to these concentrations may be carried out so that the solution has a predetermined concentration at the stage of dissolution, or may be prepared as a low-concentration solution in advance and then adjusted to a predetermined high concentration in a concentration step described later. Furthermore, after a high-concentration cellulose acylate solution is prepared in advance, various additives may be added to give a predetermined low-concentration cellulose acylate solution, and the cellulose acylate solution concentration of the present invention may be adjusted by any method. There is no particular problem if it is carried out.

Next, the present invention is characterized in that the molecular weight of aggregates of cellulose acylate in the diluted solution prepared by adding 0.1 to 1% by mass of the cellulose acylate solution with the organic solvent having the same composition is 4 to 10,000,000. And More preferably, the associated molecular weight is 4 to 7 million. This associated molecular weight can be determined by the static light scattering method. At this time, it is preferable that the radius of gyration, which is simultaneously obtained, be 40 to 200 nm. A more preferable radius of inertia square is 70 to 200 nm. Furthermore, it is preferable to dissolve so that the second virial coefficient is −2 × 10 ⁻⁴ to 4 × 10 ^−4, and more preferably the second virial coefficient is −2 × 10 ⁻⁴ to 2 × 10 ^−4. Is.

Here, the definitions of the associated molecular weight, the squared radius of gyration and the second virial coefficient will be described. These were measured using the static light scattering method according to the following method. Note that these measurements are performed in a dilute region for the convenience of the device, but these measured values reflect the behavior of the dope in the high concentration region. First, cellulose acylate is dissolved in the solvent used for the dope, and 0.1 mass%, 0.2 mass%, 0.3
A mass% and 0.4 mass% solution was prepared. In addition, in order to prevent moisture absorption, cellulose acylate was dried at 120 ° C. for 2 hours and weighed in an environment of 25 ° C. and 10% RH. The dissolution method is the method adopted when the dope was dissolved.
(Normal temperature melting method, cooling melting method, high temperature melting method). Subsequently, these solutions and the solvent were filtered through a 0.2 μm Teflon (registered trademark) filter. And
The filtered solution was measured for static light scattering by using a light scattering measuring device (DLS-700, manufactured by Otsuka Electronics Co., Ltd.) at 25 ° C. from 30 ° to 140 ° at 10 ° intervals. The obtained data was analyzed by the BERRY plot method. In addition,
For the refractive index required for this analysis, the value of the solvent obtained by the Abbe refraction system was used, and for the concentration gradient (dn / dc) of the refractive index, a differential refractometer (DRM-1021 manufactured by Otsuka Electronics Co., Ltd.) was used.
The measurement was performed using the solvent and solution used for the light scattering measurement.

Next, with respect to the preparation of the cellulose acylate solution (dope) of the present invention, the dissolution method is not particularly limited, and it may be carried out at room temperature, a cooling dissolution method or a high temperature dissolution method, or a combination thereof. It
Regarding these, for example, JP-A-5-163301, JP-A-61-106628, JP-A-58-127737,
JP-A-9-95544, JP-A-10-95854, JP-A-10-45950, JP-A-2000-53784, JP-A-11-322946, and JP-A-11-32294.
7, JP-A-2-276830, JP-A-2000-2732
39, JP-A-11-71463, JP-A-04-2595
11, JP-A-2000-273184, JP-A-11-32.
3017, JP-A No. 11-302388 and the like, a method for preparing a cellulose acylate solution is described. The above-described methods for dissolving these cellulose acylates in a non-chlorine organic solvent can also be applied to these techniques within the scope of the present invention. For details of these, please refer to the Technical Report of the Invention Association of Japan.
1-1745, issued March 15, 2001, Institute of Invention)
The method is described in detail at pages 22 to 25. Further, the dope solution of the cellulose acylate of the present invention is usually subjected to solution concentration and filtration, and similarly, the Invention Association Publication Technical Report (Publication No. 2001-1745, 2001).
(Invention Society, published March 15, 2015) in detail on page 25.

Next, a method for producing a film using the cellulose acylate solution of the present invention will be described. As the method and equipment for producing the cellulose acylate film of the present invention, the solution casting film forming method and the solution casting film forming apparatus conventionally used for the production of cellulose triacetate film are used. The dope (cellulose acylate solution) prepared from the dissolver (pot) is temporarily stored in a storage pot, and the bubbles contained in the dope are removed to make the final preparation. The dope is sent from the dope outlet to the pressurizing die through a pressurizing constant quantity gear pump that can deliver the dope with high accuracy by the number of rotations, and the dope of the casting part running endlessly from the die (slit) of the pressurizing die. The dope film (also referred to as a web), which is dry and dried, is peeled from the metal support at a peeling point which is evenly cast on the metal support and the metal support makes one round. Both ends of the obtained web are sandwiched by clips and conveyed by a tenter while keeping the width and dried, and then conveyed by rolls of a drying device to complete the drying and wound by a winder to a predetermined length. The combination of the tenter and the roll group drying device varies depending on the purpose. In the solution casting film forming method used for the silver halide photographic light-sensitive material and the functional protective film for electronic displays, in addition to the solution casting film forming device, an undercoat layer, an antistatic layer, an antihalation layer, a protective layer, etc. A coating device is often added for the surface treatment of the film.
Each of these manufacturing steps is described in detail in pages 25 to 30 of the Institute of Invention and Innovation public technical report (Kogi No. 2001-1745, issued March 15, 2001, Society of Invention).
It is classified into casting (including co-casting), metal support, drying, peeling and stretching.

The cellulose acylate film can be subjected to a surface treatment as the case may be 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 here may be low-temperature plasma that occurs under a low pressure gas of 10 ^{−3 to} 20 Torr, and plasma treatment under atmospheric pressure is also preferable. The plasma-excitable gas refers to a gas that is plasma-excited under the above conditions, and examples thereof include CFCs such as argon, helium, neon, krypton, xenon, nitrogen, carbon dioxide, and tetrafluoromethane, and a mixture thereof. it can. These are described in the Technical Bulletin published by the Invention Association (Kogi No. 2001-
1745, March 15, 2001, Institute of Invention) 3
It is described in detail on pages 0 to 32. In addition, the plasma treatment under atmospheric pressure, which has been attracting attention in recent years, includes, for example, 10 to 1
Irradiation energy of 20-500 Kgy is used under 000 Kev, and more preferably 2 under 30-500 Kev.
Irradiation energy of 0 to 300 Kgy is used. Of these, the alkali saponification treatment is particularly preferable and is extremely effective as the surface treatment of the cellulose acylate film.

In order to achieve the adhesion between the film and the emulsion layer, after the surface activation treatment, a method of directly applying a functional layer on the cellulose acylate film to obtain an adhesive force, and a method of temporarily applying a surface There is a method in which an undercoat layer (adhesive layer) is provided after the treatment or without the surface treatment, and the functional layer is applied thereon. For details of these undercoat layers, refer to the Technical Report of the Invention Association of Japan (Kogi No. 2001-1745,
(Published March 15, 2001, Institute of Invention), page 32. Also, regarding the functional layer of the cellulose acylate film of the present invention, various functional layers are disclosed in JIII Journal of Technical Disclosure (Kogi No. 2001-1745, March 1, 2001).
(Published on May 5th, Japan Institute of Invention), pages 32 to 45.

The application of the produced cellulose acylate film will be briefly described first. INDUSTRIAL APPLICABILITY The cellulose acylate film of the present invention is useful as an optical film, particularly as a polarizing plate protective film. When used as a polarizing plate protective film, the method for producing the polarizing plate is not particularly limited, and it can be produced by a general method. There is a method in which the obtained cellulose acylate film is treated with an alkali, and a polyvinyl alcohol film is immersed and stretched in an iodine solution and laminated on both surfaces of the polarizer using a completely saponified polyvinyl alcohol aqueous solution. Instead of alkali treatment, JP-A-6-94915 and JP-A-6-11882
You may give easy adhesion processing as described in each gazette of No. 32. Examples of the adhesive used to bond the protective film-treated surface to the polarizer include polyvinyl alcohol adhesives such as polyvinyl alcohol and polyvinyl butyral, vinyl latex such as butyl acrylate, and the like.

The polarizing plate is composed of a polarizer and a protective film for protecting both surfaces thereof. Further, a protective film is laminated on one surface of the polarizing plate, and a separate film is laminated on the other surface. The protect film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection. In this case, the protect film is attached for the purpose of protecting the surface of the polarizing plate, and is used on the side opposite to the side where the polarizing plate is attached to the liquid crystal plate. The separate film is used for the purpose of covering the adhesive layer that is stuck to the liquid crystal plate, and is used on the surface side where the polarizing plate is stuck to the liquid crystal plate. In a liquid crystal display device, a substrate containing a liquid crystal is usually arranged between two polarizing plates, but a polarizing plate protective film to which the optical film of the present invention is applied can obtain excellent displayability at any position. . In particular, 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, so that 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 in various applications and is particularly effective when used as an optical compensation sheet for liquid crystal display devices. The cellulose acylate film of the invention can be used in liquid crystal cells of various display modes. TN (Twisted Nemat
ic), IPS (In-Plane Switching), FLC (Ferroe)
lectric Liquid Crystal), AFLC (Anti-ferroelec)
tric Liquid Crystal), OCB (Optically Compensat)
ory Bend), STN (Supper Twisted Nematic), VA
(Vertically Aligned) and HAN (Hybrid Aligned)
Various display modes such as Nematic) have been proposed. In addition, a display mode in which the above display mode is orientation-divided is also proposed. The cellulose acylate film is effective in liquid crystal display devices of any display mode. It is also effective in any of the transmissive, reflective, and semi-transmissive liquid crystal display devices. The cellulose acylate film of the present invention is used for TN having a TN mode liquid crystal cell.
You may use it as a support body of the optical compensation sheet of a liquid crystal display device. The cellulose acylate film of the present invention is
It may be used as a support of an optical compensation sheet of an STN type liquid crystal display device having a TN mode liquid crystal cell. Generally, in an STN type liquid crystal display device, rod-shaped liquid crystalline molecules in a liquid crystal cell are twisted within a range of 90 to 360 degrees, and the refractive index anisotropy (Δn) and cell gap (d) of the rod-shaped liquid crystalline molecules are twisted. ) And (Δnd) are in the range of 300 to 1500 nm.
The optical compensation sheet used in the STN type liquid crystal display device is described in JP-A-2000-105316.
The cellulose acylate film of the invention is particularly advantageously used as a support for an optical compensation sheet of a VA type liquid crystal display device having a VA mode liquid crystal cell. The cellulose acylate film of the invention is advantageously used also as a support for an optical compensation sheet of an OCB type liquid crystal display device having an OCB mode liquid crystal cell or a HAN type liquid crystal display device having a HAN mode liquid crystal cell.

The cellulose acylate film of the present invention comprises TN type, STN type, HAN type and GH (Guest-Host).
It is also advantageously used as an optical compensation sheet for a reflection type liquid crystal display device of the type. These display modes have long been well known. The TN type reflection type liquid crystal display device is described in JP-A-10-123478, WO9848320, and Japanese Patent No. 3022477. The optical compensation sheet used for the reflective liquid crystal display device is described in International Patent Application WO00-65384. The cellulose acylate film of the present invention is ASM
It is also advantageously used as a support of an optical compensation sheet of an ASM type liquid crystal display device having a liquid crystal cell of (Axially Symmetric Aligned Microcell) mode. The ASM mode liquid crystal cell is characterized in that the cell thickness is maintained by a resin spacer whose position can be adjusted. Other properties are similar to those of the TN mode liquid crystal cell. Regarding the ASM mode liquid crystal cell and the ASM type liquid crystal display device, a paper by Kume et al. (Kume et al., SID 98 Digest 1
089 (1998)). The detailed applications of these cellulose acylate films described above are described in JIII Journal of Technical Disclosure (Kogi No. 2001-1745, 2001 March).
(Invention Society), pages 15 to 59, in detail.

[0040]

Examples In each example, cellulose acylate,
The chemical and physical properties of solutions and films are:
It was measured and calculated as follows.

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

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

(3) Film lumps (abbreviated as lumps) The obtained films were visually observed, and the lumps on the surface were evaluated as follows. A: No spots were found on the surface of the film. B: Some spots were found on the surface of the film. C: Significant spots were observed on the film surface. D: Unevenness was observed on the film surface, and many spots were recognized.

(4) Haze of film The haze was measured using a 1001DP type (manufactured by Nippon Denshoku Industries Co., Ltd.).

Example 1 (1-1) Preparation of Cellulose Acylate Solution In a 100 L stainless steel dissolution tank having a stirring blade, the following solvent mixed solution was well stirred and dispersed, and Table 1 was prepared.
The cellulose acylate powder (flakes) described in 1 above was gradually added, and the whole was charged to 40 kg. As the solvent, methyl acetate, butanol, acetone, methanol, and ethanol were used, all having a water content of 0.2 mass% or less. First, for powder of cellulose triacetate, powder was put into a dispersion tank, the pressure in the tank was reduced to 1300 Pa, and the stirring shear rate was initially 15 m.
/ Sec (shear stress 5 × 104 kgf / m / sec ² )
Dissolver type eccentric stirring shaft that stirs at a peripheral speed of 1 and an anchor blade on the central axis, and disperse for 30 minutes under the condition of stirring at a peripheral speed of 1 m / sec (shear stress 1 × 104 kgf / m / sec ² ). did. The starting temperature of dispersion was 25 ° C, and the final temperature reached was 48 ° C. After the dispersion was completed, the high-speed stirring was stopped, the peripheral speed of the anchor blade was set to 0.5 m / sec, and the stirring was continued for 100 minutes to swell the cellulose triacetate flakes. Until the end of swelling, the inside of the tank was pressurized with nitrogen gas to 0.12 MPa. At this time, the oxygen concentration in the tank was less than 2 vol%, and there was no problem in explosion protection. The water content in the dope is 0.
It was confirmed to be 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 diameter 1.5 mm, standard deviation 0.5 mm
Powder) (addition amount is shown in Table 1), methyl acetate (5
8 parts by mass), acetone (5 parts by mass), methanol (5 parts by mass), ethanol (5 parts by mass), butanol (addition amount is shown in Table 1), plasticizer A (ditrimethylolpropane tetraacetate) (1. 2 parts by mass), plasticizer B (triphenyl phosphate) (1.2 parts by mass), UV agent a
(2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,
3,5-triazine (0.2 parts by mass), UV agent b (2
(2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole) (0.2 parts by mass), 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
Mass part) and citric acid monoethyl ester (0.04 mass part) were used. The main solvent used here, methyl acetate, has a solubility parameter of 19.6, and acetone used in combination has a solubility parameter of 20.3. Further, the cellulose triacetate used here has a residual acetic acid content of 0.1% by mass or less,
Was 0.05% by mass, Mg was 0.007% by mass, and Fe was 5 ppm. The 6-position acetyl group was 0.95, which was 32.2% of all acetyl groups. The acetone extracted content was 11% by mass, and the ratio of the weight average molecular weight to the number average molecular weight was 0.5, showing a uniform distribution. The haze was 0.08, the transparency was 93.5%, the Tg was 160 ° C., and the crystallization heat value was 6.2 J / g.

(1-2) Cellulose triacetate film solution The obtained non-uniform gel-like solution is fed by a screw pump whose axial center is heated to 30 ° C., and cooled from the outer periphery of the screw to -75. The cooling part was passed through for 3 minutes at 0 ° C. Cooling was performed using a refrigerant of -80 ° C cooled in a refrigerator. Then, the solution obtained by cooling was heated to 50 ° C. while being fed by a screw pump and transferred to a stainless steel container. After stirring at 50 ° C. for 2 hours to form a uniform solution, the solution was filtered with a filter paper having an absolute filtration accuracy of 0.01 mm (# 63 manufactured by Toyo Roshi Kaisha, Ltd.), and further a filter paper having an absolute filtration accuracy of 2.5 μm (manufactured by Pall Ltd., It was filtered through FH025).

(1-3) Preparation of Cellulose Triacetate Film The filtered cellulose triacetate solution at 50 ° C. is
It was cast on a mirror-like stainless steel support through a casting castor. Support temperature is 0 ℃, casting speed is 40m /
The coating width was 70 cm in minutes. Drying was carried out at 55 ° C. for drying. Peel off from the mirror-like stainless steel support after 5 minutes (solid content concentration immediately after peeling at this time is about 30-
60% by mass), followed by drying at 110 ° C. for 5 minutes and then at 140 ° C. for 10 minutes (film temperature is about 130 ° C.)
Then, the cellulose triacetate film (film thickness 80μ
m) was obtained.

(1-4) Results Table 1 shows the evaluation results of the obtained samples. The control sample 1-1 and the comparative sample 1-2 of the present invention, which had a low concentration of cellulose acylate and a high degree of association polymerization, were markedly inferior in peeling residue, unevenness, and haze.
On the other hand, Samples 1-2 to 1-8 of the present invention had no peeling residue, no unevenness, no spots, and a small haze, and were excellent in surface condition. Further, Comparative Samples 1-9 to 1-11 in which the solution concentration of cellulose acylate was low or the molecular weight of the aggregate was out of the range of the present invention had remarkably unpeeled residue and bad unevenness and haze. In addition, the inertia square radius in the samples 1-2 to 1-8 of the present invention is 40 to 2
00 nm, and the second virial coefficient is −2 × 10 ^−4.
It was confirmed to be 4 × 10 ⁻⁴ .

[0050]

[Table 1]

Example 2 Sample 2-4 of the present invention was obtained in the same manner as in Example 1 except that the (1-2) cellulose triacetate film solution was changed to the following.

(1-2) Cellulose triacetate film solution The obtained non-homogeneous gel solution was fed by a screw pump and passed through a heating part heated at 140 ° C. and 1 MPa for 3 minutes. , 110 ° C., 1 MPa, heated and pressurized, filtered through a filter paper with an absolute filtration accuracy of 0.01 mm (# 63 manufactured by Toyo Roshi Kaisha, Ltd.), and further, a filter paper with an absolute filtration accuracy of 0.0025 mm (PH, FH025). ).

(2-1) As a result, the sample 2-4 of the present invention was excellent in filterability, had no peeling residue, and was excellent in unevenness, spots and haze.
From this, it was confirmed that in the present invention, an excellent cellulose acetate solution and cellulose acetate film can be produced even at high temperature and high pressure dissolution.

[Example 3] Sample 3-4 of the present invention was prepared in the same manner as in Example 1 except that plasticizers A and B were both removed in an amount of 0 parts by mass in Sample 1-4 of Example 1. It was made. The obtained sample 3-4 was excellent in that there was no peeling residue, the unevenness and the spots were both A, and the haze was 0.3. On the other hand, when the folding endurance test was conducted,
Sample 1-4 was 95 times, whereas sample 3-4, which was within the scope of the present invention and had no plasticizer, had a cutting resistance test of 84 times, which was not a problem in practical use, but was slightly inferior. Therefore, in the present invention, it is clear that the cellulose acylate film containing a plasticizer is a more preferable embodiment. Here, the folding endurance was evaluated by the sample 120 mm × 120
mm was conditioned for 2 hours in an environment of 23 ° C. and 65% RH, and evaluated by measuring the number of reciprocations until bending and cutting in accordance with ISO8776-1988.

Example 4 Sample 4-6 of the present invention was carried out in exactly the same manner as in Example 1 except that UV agents a, b and c were all removed as 0 parts by mass in Sample 1-6 of Example 1. Was produced. The obtained Samples 4-6 were excellent in that there was no peeling residue, unevenness and spots were evaluation A, and haze was 0.2. On the other hand, when the photofading test was carried out for 1 month for a xenon lamp of 20,000 lux, the haze of Sample 1-6 was 0.4%, whereas the haze of Sample 4-6 was within the scope of the present invention. Was slightly improved to 0.6. Therefore, in the present invention, it is clear that the cellulose acylate film contains a UV agent in a more preferable embodiment.

[Example 5] Sample 5-7 of the present invention was prepared in exactly the same manner as in Example 1 except that fine particles of silica were removed as 0 parts by mass in Sample 1-7 of Example 1. The obtained sample 5-7 was an excellent sample in which no peeling residue was left, unevenness and spots were evaluated as A, and haze was 0.2. On the other hand, when the slipperiness was examined by stacking two sheets of the film, Sample 1-7 can smoothly move the two sheets, but within the scope of the present invention, Sample 5-
In No. 7, the movement between the films was a little bad. Therefore, in the present invention, it is clear that the cellulose acylate film contains fine particles as a more preferable embodiment.

[Example 6] Sample 1 of the present invention of Example 1-
5, except that the production of the (1-2) cellulose triacetate film of Example 1 was changed to
In exactly the same manner as described above, the cellulose triacetate film of Sample 6-5 of the present invention was produced. 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 it by adding 10% by mass of methyl acetate. The obtained solution was co-cast with the cellulose triacetate solution of Sample 1-5 inside and with the cellulose triacetate solution (solution A) on both sides thereof according to the co-casting method described in JP-A-06-134993. 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.
It was set to 0 μm. The surface condition of the obtained sample 6-5 was more excellent than that of the sample 1-5, with a smoother surface and no unevenness. Therefore, it is apparent that co-casting is an even more excellent mode in the present invention.

[Example 7] In Example 1 of JP-A-11-316378, a cellulose triacetate film (second film) obtained from Sample 1-4 of Example 1 of the present invention was used as the first transparent support. Except that the thickness is changed to 100 μm.
-Example 3 of -316378 gazette was implemented, and sample 7-
4 was produced. The optical characteristics of the obtained elliptically polarizing plate were excellent. Therefore, it is clear that the use of a specific washing solution in the production process of the present invention is a preferable mode in which the cellulose acylate film produced thereafter is applicable to an optical polarizing plate without any problem.

[Example 8] Sample 1 of the present invention in Example 1-
4 to the cellulose triester film described in JP-A-7-3
Fuji Photo Film Co., Ltd. of Example 1 of Japanese Patent No. 33433
An optical compensation filter film sample was prepared in exactly the same manner as in Example 1 of JP-A-7-333433, except that the cellulose triacetate produced was changed to the cellulose triacetate film of Sample 1-4 of the present invention. The obtained filter film had an excellent viewing angle on the left, right, top and bottom. Therefore, it is understood that the cellulose triacetate film of the present invention is excellent for optical use.

[Embodiment 9] Further, in the present invention, the liquid crystal display device described in Embodiment 1 of Japanese Unexamined Patent Publication No. 10-48420 is used as a representative of the present invention for various optical applications. Example 1 of JP-A-9-26572
An optically anisotropic layer containing discotic liquid crystal molecules, an alignment film coated with polyvinyl alcohol,
2 to 9 of Japanese Unexamined Patent Publication No. 00-154261, and FIG. 1 of Japanese Unexamined Patent Publication No. 2000-154261.
When used in the OCB type liquid crystal display devices described in 0 to 15, good performance was obtained.

[Example 10] Sample 1 of the present invention of Example 1
-3, except that the film thickness was 120 μm, Sample 10-3 of the present invention, which is the film, was produced in exactly the same manner as in Example 1. 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 to prepare a back layer having a cationic polymer as a conductive layer. . Furthermore, on the opposite surface of the film base provided with the obtained back layer,
Sample 105 of Example 1 of Japanese Patent Laid-Open No. 11-38568
Was applied to prepare a silver halide color photographic light-sensitive material. The obtained color film had excellent images and was easy to handle.

[Example 11] Sample 1 of the present invention of Example 1
-3, except that the butanol was changed to isopropanol and the amount thereof was changed to 8 parts by mass, the film of the present invention, Sample 11-3, was prepared in exactly the same manner as in Example 1. The obtained diluted solution had an aggregate molecular weight of 5,700,000, unpeeled residue A, unevenness A and spot A, and a haze as small as 0.3, which was excellent in all respects.

[Embodiment 12] Sample 1 of the present invention of Embodiment 1
In -6, a film of the present invention, Sample 12-3, was prepared in exactly the same manner as in Example 1 except that methyl acetate was changed to methylene chloride. The resulting dilute solution had an aggregate molecular weight of 6.3 million, peeling residue A, unevenness A and spot A, and a haze as small as 0.3, which was excellent in all respects.

[0064]

According to the present invention, when the cellulose acylate film is cast on the support of the cellulose acylate solution in the production process and then the cellulose acylate film is stripped off, a solution having good strippability at high speed is obtained. With this solution, it is possible to provide a cellulose acylate film that is free from unevenness and spots. Further, a cellulose triester film having excellent optical anisotropy and excellent film strength can be provided. Furthermore, a cellulose triacetate film excellent as a support for a light-sensitive material can be produced.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 1:10 C08L 1:10 F term (reference) 2H023 FA01 4F071 AA09 AC06 AC07 AC10 AH19 BA02 BB02 BC01 4F205 AA01J AB06 AB07 AB20 AC04 AC05 AG01 AH73 AR20 GA07 GC06 GE22 GF02 GF03 GF24 GN13 GN18 GN21 GN29

Claims (8)

[Claims] 1. Cellulose acylate is added to an organic solvent in an amount of 15
A cellulose acylate solution having a dissolved amount of ˜30% by mass, wherein the solution has a molecular weight of 4,000,000 to 10,000,000 associated with the cellulose acylate in a diluted solution of 0.1 to 1% by mass with an organic solvent having the same composition. (25 ° C.) A cellulose acylate film produced from a cellulose acylate solution. 2. The cellulose acylate according to claim 1, wherein the cellulose acylate is a cellulose acylate in which the degree of substitution of the hydroxyl group of cellulose satisfies all of the following formulas (I) to (III). Rate film: (I) 2.6 ≦ SA + SB ≦ 3.0 (II) 2.0 ≦ SA ≦ 3.0 (III) 0 ≦ SB ≦ 0.8 [In the formula, SA and SB are hydroxyl groups of cellulose. SA represents a substituent of a substituted acyl group; SA represents a substitution degree of an acetyl group; and SB represents a carbon atom number of 3 to 22.
Represents the substitution degree of the acyl group]. 3. The organic solvent is a non-chlorine organic solvent having 3 to 12 carbon atoms, and having 3 to 1 carbon atoms.
The cellulose acylate film according to claim 1, which is at least one solvent selected from the ketones of 2 and the esters of 3 to 12 carbon atoms. 4. A cellulose acylate solution having the following (I
The cellulose acylate film according to claim 1, which is obtained by at least one preparation method of V) to (VI): (IV) a step of swelling at -10 to 55 ° C,
Method for preparing cellulose acetate solution comprising heating cellulose acetate to 57 ° C to dissolve cellulose acetate in organic solvent (V) Swelling at -10 to 55 ° C, -100 to -1
Cooling to 0 ° C., and cooling the cooled mixture from 0 to 57
Method for preparing a cellulose acetate solution comprising the step of heating cellulose acetate in an organic solvent by heating to (VI) -swelling at -10 to 55 ° C, 0.2 to 30M
A preparation method comprising the steps of heating at 60 to 240 ° C. at high pressure and high temperature in Pa, and cooling the heated mixture to 0 to 57 ° C. to dissolve cellulose acetate in an organic solvent. 5. When mixing the cellulose acylate and the organic solvent, 90% by mass or more of the cellulose acylate,
Using a particle having a particle size of 0.1 to 5 mm, a step of filtering the obtained cellulose acylate solution, a step of casting the cellulose acylate solution on a support, a step of peeling off, a solvent evaporation film The cellulose acylate film according to claim 1, which is produced from a drying step of forming a film, and a step of winding the produced cellulose acylate film. 6. The cellulose acylate solution contains at least one plasticizer in an amount of 0.1 to cellulose acylate.
To be a cellulose acylate solution containing 20 to 20% by mass, and / or a cellulose acylate solution containing at least one ultraviolet absorber in an amount of 0.001 to 5% by mass based on the cellulose acylate. And / or a cellulose acylate solution containing at least one kind of fine particle powder in an amount of 0.001 to 5% by mass with respect to the cellulose acylate, and / or at least one fluorine-containing surfactant as a cellulose acylate solution. It is a cellulose acylate solution containing 0.001 to 2% by mass relative to the rate, and / or at least one release agent is 0.0001 to 2 relative to the cellulose acylate.
A cellulose acylate solution containing 1% by mass, and / or a cellulose acylate solution containing 0.0001 to 2% by mass of at least one deterioration inhibitor with respect to the cellulose acylate, and 2. A cellulose acylate film according to claim 1, which is a cellulose acylate solution containing 0.1 to 15% by mass of at least one optical anisotropy controlling agent with respect to the cellulose acylate. . 7. The cellulose acylate film according to claim 1, wherein two or more kinds of cellulose acylate solutions are co-cast in the casting step. 8. The produced cellulose acylate film is a cellulose acylate film used as an optical protective layer and has a film thickness of 10 to 500 μm, or the produced cellulose acylate film is a halogen. The cellulose acylate film according to claim 1, which is used as a support for silver halide photographic light-sensitive material and has a film thickness of 30 to 250 µm.