JP2003094466A - Method for manufacturing cellulose acylate film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a cellulose acylate film having a good surface state by easily releasing the film from a support in its manufacturing step in the case of obtaining a solution by dissolving a cellulose acylate in a chlorine organic solvent in a stable state and thereby obtaining the excellent cellulose acylate film. SOLUTION: A method for manufacturing the cellulose acylate film comprises a step of forming a film by casting a cellulose acylate solution in such a manner that the solution contains at least 15 to 30 mass% of the cellulose acylate in the chlorine organic solvent (the chlorine organic solvent is at least 50 mass% or more of the total organic solvent), 5% or more of weight fraction of molecules or associated matters having a particle size of 100 nm or more exists, the associated material having the number of associations of 5 or more exists or 5% or more of a weight fraction or an abundance of associated matters by number of 5% or more exists.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a silver halide photographic light-sensitive material or a cellulose acylate film useful as, for example, a polarizing plate protective film of a liquid crystal display device.

[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 and a polarizing plate protective film of a liquid crystal image display device is methylene chloride. Such chlorine-containing hydrocarbons have been 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 manufacturing process and is easily dried. In recent years, chlorine-based organic solvents, which have a low boiling point from the viewpoint of environmental protection, have significantly reduced leakage in the handling process even in closed equipment. For example, a thorough closed system was used to prevent leakage from the system, and in the unlikely event of a leak, a method was set up in which a gas absorption tower was installed to adsorb an organic solvent before it was released into the atmosphere, and then treated. further,
Almost no organic solvent was discharged due to combustion by thermal power or decomposition of chlorine-based organic solvent by electron beam before discharging.

On the other hand, a search has been made for a solvent for cellulose acylate other than methylene chloride, which has been preferably used as a chlorine-based organic solvent. Acetone (boiling point 56) is known as one known as an organic solvent exhibiting solubility in cellulose acylate, particularly cellulose triester.
° 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.degree. 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. Also,
In JP-A-9-95538, JP-A-9-95544, and JP-A-9-95557, in the background of the above technique,
It is disclosed that cellulose acylate is dissolved by a cooling dissolution method using a chlorine-free organic solvent. As the non-chlorine organic solvent used at that time, ethers,
An organic solvent selected from ketones or esters, and in particular, a film is prepared by dissolving cellulose acylate by a cooling dissolution method. Specific examples of these organic solvents include acetone, 2-methoxyethyl acetate,
Cyclohexanone, ethyl formate, and methyl acetate are preferred. However, even if these solvents are used, sufficient dissolution of the cellulose acylate is achieved, and it is still far from obtaining a cellulose acylate film by high speed casting.

Cellulose acylate film is generally produced by a solvent casting method or a melt casting 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, after casting the dope on the support,
It has been a subject to shorten the time required to peel off the molding film on the support and improve the productivity of the film forming process. In particular, when a cellulose acylate film is obtained by the solvent casting method, in the case of a cellulose acylate solution which is dissolved at room temperature, high temperature or by cooling using the above-mentioned non-chlorine organic solvent, peeling of the cellulose acylate film from its support is carried out. The problem is that it is difficult to remove. Further, 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, which is peeled from the support 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. It was also found in the chlorine-based organic solvent of methylene chloride, and its improvement was desired as described above. As one method of this improvement, Japanese Patent Laid-Open No.
-316701, the acid dissociation index pKa 1.93-4.
50 [preferably 2.0 to 4.4, more preferably 2.2 to 4.3 (for example, 2.5 to 4.0), particularly 2.
It is described that an acid of 6 to 4.3 (for example, about 2.6 to 4.0) or a salt thereof is preferable as the stripping agent. However, as a drawback of this method, a problem occurs in which 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. And the improvement was expected. 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 a chlorine-based organic solvent,
It is to solve the problem that peeling from the support is difficult due to drying after casting, and to produce a cellulose acylate film which is excellent not only in peeling but also in good condition. In particular, even if the casting speed is high, it is to form a cellulose acylate solution that is peeled off or has a good surface condition to produce an excellent cellulose acylate film.

An object of the present invention is to provide a cellulose acylate film having an excellent surface condition by casting a cellulose acylate solution prepared by a room temperature dissolution method, a cooling dissolution method or a high temperature high pressure dissolution method using a chlorine-based organic solvent. To do. Further, it is an object of the present invention to easily peel the film from the support for drying after casting and to impart excellent productivity.

[0009]

These objects have been solved by the following means. (1) In the method for producing a cellulose acylate film, which comprises casting a cellulose acylate solution into a film, the cellulose acylate solution is prepared from a chlorine-based organic solvent (chlorine-based organic solvent is at least 50% by mass of all organic solvents). Solution containing 15 to 30% by mass of cellulose acylate, and the weight fraction of the cellulose acylate molecule or aggregate having a particle size of 100 nm or more in the solution is 5 to 100.
%, And a method for producing a cellulose acylate film.

(2) In the method for producing a cellulose acylate film, which comprises casting a cellulose acylate solution into a film, the cellulose acylate solution comprises a chlorine-based organic solvent (chlorine-based organic solvent is at least 50% by mass of all organic solvents). 15-30 of cellulose acylate in a solution consisting of
A method for producing a cellulose acylate film, characterized in that it contains 5% by mass of a cellulose acylate aggregate having an association number of 5 or more in the solution.

(3) In the method for producing a cellulose acylate film, which comprises casting a cellulose acylate solution into a film, the cellulose acylate solution comprises a chlorine-based organic solvent (chlorine-based organic solvent is at least 50% by mass of all organic solvents). 15-30 of cellulose acylate in a solution consisting of
A method for producing a cellulose acylate film, which comprises 5% to 100% of the aggregates in the cellulose acylate aggregate having an association number of 5 or more, which is contained by mass%.

(4) The cellulose acylate is a cellulose acylate composed of a single or a mixture of which the degree of substitution of the hydroxyl group of cellulose satisfies all of the following formulas (I) to (III). The method for producing a cellulose acylate film according to any one of (1) to (3), characterized in that (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 is the degree of substitution of the acetyl group, and SB is the degree of substitution of the acyl group having 3 to 22 carbon atoms.

(5) In the preparation of the cellulose acylate solution, the cellulose acylate solution obtained from at least one of the following preparation methods (i) to (iii) is prepared (1) to ( 4) The method for producing a cellulose acylate film according to any one of items. (I) A step of swelling at -10 to 40 ° C,
A method for preparing a cellulose acetate solution, which comprises the steps of heating to -40 ° C and dissolving cellulose acetate in a chlorine-based organic solvent. (Ii) a step of swelling at -10 to 40 ° C, -100 to -1
Cooling to 0 ° C., and cooling the cooled mixture from 0 to 57
A method for preparing a cellulose acetate solution, which comprises the step of heating cellulose acetate in a chlorine-based organic solvent by heating to 0 ° C. (Iii) Step of swelling at -10 to 40 ° C, 0.2 to 30
A preparation method comprising a step of heating at 60 to 240 ° C. at a high pressure and a high temperature with Mpa, and a step of cooling the heated mixture to 0 to 57 ° C. to dissolve cellulose acetate in a chlorine-based organic solvent.

(6) A step of preparing a cellulose acylate solution by mixing cellulose acylate and a non-chlorine organic solvent, a step of filtering the obtained cellulose acylate solution, and a step of flowing the cellulose acylate solution on a support. It is characterized by comprising a step of rolling, a step of stripping, a step of drying a film by evaporating a solvent, and a step of winding the produced cellulose acylate film (1).
(5) The manufacturing method according to any one of (5).

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION First, the cellulose acylate used in the present invention will be described in detail. The cellulose acylate of the present invention is not particularly limited as long as it exhibits the effects of the present invention. In the present invention, two or more different types of cellulose acylate may be mixed and used. However, among them, preferred cellulose acylates include the following materials. That is, the cellulose acylate is a cellulose acylate in which the substitution degree 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 is the degree of substitution of the acetyl group, and SB is the degree of substitution of the acyl group having 3 to 22 carbon atoms. The β-1,4-bonded glucose unit that constitutes 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 total sum of the substitution degrees of SA and SB of the hydroxyl group is more preferably 2.70 to 2.96, and particularly preferably 2.80 to 2.95. The degree of substitution of SB is 0 to 0.8, and particularly 0 to 0.
It is 6. Further, 28% or more of SB is a substituent of 6-position hydroxyl group, more preferably 30% or more is a substituent of 6-position hydroxyl group, further preferably 31%, particularly 3
It is also preferable that 2% or more is a substituent of the 6-position hydroxyl group.
Furthermore, the total substitution degree of SA and SB at the 6-position of the cellulose acylate is 0.80 or more, and further 0.85.
In particular, a cellulose acylate film having 0.90 can also be mentioned. With these cellulose acylate films, a solution having a preferable solubility can be prepared,
In particular, a good solution can be prepared in a non-chlorine organic solvent.

SB is the substitution degree of an acyl group having 3 to 22 carbon atoms. The acyl group (SB) having 3 to 22 carbon atoms of the cellulose acylate of the present invention may be an aliphatic group or an allyl group and is not particularly limited. 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. These preferred SBs include propionyl, butanoyl,
Keptanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, iso-butanoyl, t-butanoyl, cyclohexanecarbonyl,
Examples thereof include oleoyl, benzoyl, naphthylcarbonyl and cinnamoyl groups. Among these,
Examples include propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, oleoyl, benzoyl, naphthylcarbonyl and cinnamoyl.

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 cellulose acylate preferably used in the present invention is a viscosity average degree of polymerization of 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 weight component is removed, the average molecular weight (polymerization degree) 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. When producing a cellulose acylate having 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 with respect to 100 parts by weight 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). When used in the production of the cellulose acylate of the present invention, its water content is preferably 2% by mass or less,
It is more preferably 1% by mass or less, and particularly preferably a cellulose acylate having a water content of 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 obtain the water content of the cellulose acylate, it is necessary to dry it, and the method is not particularly limited as long as the desired water content is obtained. For these cellulose acylates of the present invention, the raw material cotton and the synthesis method are described in detail in pages 7 to 12 of the Institute of Invention and Innovation published technical report (public technique number 2001-1745, published on March 15, 2001, Institute of Invention). It is described in.

The cellulose acylate solution of the present invention contains
Various additives (for example, plasticizers, UV inhibitors, deterioration inhibitors, optical anisotropy control agents, fine particles, release agents, infrared absorbers, etc.) can be added in each preparation step depending on the application. , They may be solid or oily. That is, the melting point and the boiling point are not particularly limited. For example, mixing of UV absorbing materials at 20 ° C. or lower and 20 ° C. or higher, mixing of plasticizers, and the like are also described, for example, in JP-A No. 2001-151901. Furthermore, the infrared absorbing dye is described in, for example, JP-A No. 2001-194522. Further, the addition may be carried out at any time in the dope preparation step, but may be carried out by adding a step of adding an additive to the final preparation step of the dope preparation step. Furthermore,
The addition amount of each material is not particularly limited as long as the function is exhibited. Further, when the cellulose acylate film is formed from multiple layers, the type and amount of the additive in each layer may be different. For example, it is described in Japanese Patent Application Laid-Open No. 2001-151902, but these are known techniques. Further details of these can be found in JIII Journal of Technical Disclosure (Kogi No. 2001-1745, March 1, 2001).
Materials described in detail on pages 16 to 22 by the Institute of Invention and Innovation, 5th day are preferably used.

Next, the chlorine-based organic solvent used in preparing the cellulose acylate solution of the present invention will be described. In the present invention, the chlorine-based organic solvent is not particularly limited as long as the purpose can be achieved within the range in which the cellulose acylate can be dissolved, cast and film-formed. The chlorine-based organic solvent of the present invention is preferably dichloromethane or chloroform. Dichloromethane is particularly preferable. In the present invention, mixing of an organic solvent other than the chlorine-based organic solvent is also not a particular problem. In that case, it is necessary to use at least 50 mass% of dichloromethane. The non-chlorine type organic solvent used in combination with the present invention is described below. That is, as the preferable non-chlorine-based organic solvent, a solvent selected from esters, ketones, ethers, alcohols, hydrocarbons and the like having 3 to 12 carbon atoms is preferable. The ester, ketone, ether and alcohol may have a cyclic structure. A compound having two or more of any of ester, ketone and ether functional groups (that is, -O-, -CO- and -COO-) can also be used as a solvent, and other functional groups such as an alcoholic hydroxyl group can be used. You may have a group simultaneously. In the case of a 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:
Mention may be made of ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate. 3 to 12 carbon atoms
Examples of ketones of acetone include acetone, methyl ethyl ketone,
Mention may be made of diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and methylcyclohexanone. Examples of ethers having 3 to 12 carbon atoms 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 alcohol may be 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 alcohols include methanol, ethanol, 1-propanol, 2-propanol, 1-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.

The non-chlorine type organic solvent used in combination with the chlorine type organic solvent which is the main solvent used for the above cellulose acylate is not particularly limited, but methyl acetate, ethyl acetate, methyl formate, ethyl formate, acetone, It is selected from dioxolane, dioxane, ketones or acetoacetic acid esters having 4 to 7 carbon atoms, alcohols or hydrocarbons having 1 to 10 carbon atoms. The preferred non-chlorine organic solvent used in combination is methyl acetate, acetone, methyl formate, ethyl formate, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl acetyl acetate, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol. , 2-butanol, and cyclohexanol, cyclohexane, hexane can be mentioned. The preferable combination of the organic solvent of the present invention can include, but is not limited to, the following.

Dichloroethane / methanol / ethanol / butanol (75/10/5/5/5, parts by mass), dichloroethane / acetone / methanol / propanol (80/10/5/5, parts by mass), dichloroethane / Methanol / butanol / cyclohexane (75/10/5/5/5, parts by mass), dichloroethane / methyl ethyl ketone / methanol /
Butanol (80/10/5/5, parts by mass) ・ Dichloroethane / acetone / methyl ethyl ketone / ethanol / isopropanol (75/10/10/5 /
7, parts by mass), dichloroethane / cyclopentanone / methanol / isopropanol (80/10/5/8, parts by mass), dichloroethane / methyl acetate / butanol (80/1
0/10, parts by mass), dichloroethane / cyclohexanone / methanol / hexane (70/20/5/5, parts by mass), dichloroethane / methyl ethyl ketone / acetone / methanol / ethanol (50/20/20/5/5, Parts by mass), dichloroethane / 1,3 dioxolane / methanol /
Ethanol (70/20/5/5, parts by mass),-Dichloroethane / dioxane / acetone / methanol / ethanol (60/20/10/5/5, parts by mass) -Dichloroethane / acetone / cyclopentanone / ethanol / Isobutanol / Cyclohexane (65/1
0/10/5/5/5, parts by mass), dichloromethane / methyl ethyl ketone / acetone / methanol / ethanol (70/10/10/5/5, parts by mass), dichloromethane / acetone / ethyl acetate / ethanol / butanol / Hexane (65/10/10/5/5 /
5 parts by mass), dichloromethane / methyl acetoacetate / methanol / ethanol (65/20/10/5, parts by mass), dichloromethane / cyclopentanone / ethanol / butanol (65/20/10/5, parts by mass) ), And so on.

In the present invention, the cellulose acylate solution contains 15 to 3 cellulose acylate in a chlorine-based organic solvent.
It is characterized in that it is a solution containing 0% by mass of dissolution, more preferably 17 to 27% by mass, and particularly 1
A cellulose acylate solution in which 8 to 25% by mass is dissolved is preferable. The method for carrying out the cellulose acylate at these concentrations may be carried out so that the solution has a predetermined concentration at the stage of dissolution, or is prepared as a low-concentration solution in advance and then adjusted to a predetermined high concentration in the concentration step described later. You may. 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 in any method, the cellulose acylate solution concentration of the present invention can be obtained. There is no particular problem if it is carried out.

In the present invention, in a cellulose acylate solution,
The weight fraction of the cellulose acylate molecule or aggregate having a particle diameter of 100 nm or more is 5 to 100%, more preferably 50 to 100%.

In the cellulose acylate solution, the weight fraction of the cellulose acylate aggregate having an association number of 5 or more is 5
-100%, but more preferably the weight fraction is 50-
That is 100%.

In the cellulose acylate solution, the presence ratio of the number of associated aggregates of cellulose acylate having an association number of 5 or more is 5 to 100%, more preferably 10 to 100% by weight. Is.

The abundance ratio of aggregates in the present invention is the ratio of the number of aggregates. The number of aggregates is calculated from the weight fraction of the aggregates and the number of associations, and the number of associations is the peak average value of the particle size determined by the dynamic light scattering method, and the molecular weight of aggregates and the number of single molecules determined by static light scattering. Calculate from molecular weight. In the present invention, the peak average value of particle diameter, the weight fraction of particle diameter, and the weight fraction of aggregates were measured by dynamic light scattering according to the following methods.

The weight fraction of particle size, the weight fraction of aggregates, and the abundance ratio of aggregates in a solution of 15 to 30 mass% are
It is known that there is no change even if the solution is diluted, and it can be measured with a diluted solution (for example, 0.1 to 15% by mass) for ease of measurement. Therefore, the details of the measurement with the diluted solution are shown below. The solution temperature for measurement is not particularly specified, but the solution temperature is preferably -10 to 50 ° C. First, cellulose acylate was dissolved in the solvent used for the dope to prepare a 0.5% by mass solution. In order to prevent moisture absorption, cellulose acylate was dried at 120 ° C. for 2 hours and weighed at 25 ° C. and 10% RH. The melting method is the method adopted when melting the dope (normal temperature melting method,
The cooling dissolution method and the high temperature dissolution method) were used. Subsequently, these solutions and the solvent were filtered through a 0.2 μm Teflon (registered trademark) filter, and a light scattering measurement device (DLS-7000 manufactured by Otsuka Electronics Co., Ltd.) was used at a temperature of 5 ° C. and 25 ° C.
The measurement was carried out at a measurement angle of 90 ° at 40 ° C and 40 ° C. The obtained data was analyzed by the Marcat method. Solvent viscosity is Ubbelohde viscometer, solvent refractive index is Abbe refractometer,
The measurement was performed using the solvent and solution used for the light scattering measurement. The results did not show any dependence on the measured temperature.

The molecular weight of the aggregate and the single molecular weight in the present invention were measured by static light scattering according to the following method. The measurement conditions are the same as those for dynamic light scattering. The sample was prepared in the same manner as the dynamic light scattering and measured by the same device. The change is the solution concentration (0.
1% by mass, 0.2% by mass, 0.3% by mass, 0.4% by mass) and the measurement angle (measured at intervals of 10 degrees from 30 ° to 140 °). The obtained data was analyzed by the Berry plot method. The refractive index required for the analysis depends on the value of the solvent obtained by the Abbe refraction system, and the concentration gradient (dn / dc) of the refractive index is measured by a differential refractometer (DRM-1021 manufactured by Otsuka Electronics Co., Ltd.).
The measurement was performed using the same solvent and solution as the light scattering measurement. In addition,
The results showed no dependence on the measured temperature.

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.

When the cellulose acylate and the chlorine-based organic solvent are mixed, it is preferable to use particles in which 90% by mass or more of the cellulose acylate is 0.1 to 5 mm,
In preparing the cellulose acylate solution, it is preferable to employ at least one of the following preparation methods (i) to (iii). (I) A step of swelling at -10 to 40 ° C,
A method for preparing a cellulose acetate solution, which comprises the steps of heating to -40 ° C and dissolving cellulose acetate in a chlorine-based organic solvent. (Ii) a step of swelling at -10 to 40 ° C, -100 to -1
Cooling to 0 ° C., and cooling the cooled mixture from 0 to 57
A method for preparing a cellulose acetate solution, which comprises the step of heating cellulose acetate in a chlorine-based organic solvent by heating to 0 ° C. (Iii) Step of swelling at -10 to 40 ° C, 0.2 to 30
A preparation method comprising a step of heating at 60 to 240 ° C. at a high pressure and a high temperature with Mpa, and a step of cooling the heated mixture to 0 to 57 ° C. to dissolve cellulose acetate in a chlorine-based organic solvent.

Further, the dope solution of cellulose acylate of the present invention is usually subjected to solution concentration and filtration, and similarly, the Institute of Invention and Innovation (Gazette No. 2001-1745, 20).
Invention Society, published March 15, 2001) on page 25.

Next, a method for producing a film using the cellulose acylate solution of the present invention will be described. As the production method of the present invention, basically, a step of preparing a cellulose acylate solution by mixing a cellulose acylate and a non-chlorine organic solvent, a step of filtering the resulting cellulose acylate solution, a cellulose acylate It comprises a step of casting the solution on a support, a step of peeling it off, a step of drying the solvent to form a film, and a step of winding the produced cellulose acylate film. As the method and equipment for producing the cellulose acylate film of the present invention, a solution casting film forming method and a solution casting film forming apparatus conventionally used for producing a cellulose triacetate film 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 filtered to remove foreign matters before casting. From the dope outlet, send the dope to the pressure die through a pressure metering gear pump that can accurately deliver a fixed amount by the number of rotations,
The dope is evenly cast from the die (slit) of the pressure die onto the metal support of the casting part that is running endlessly, and at the peeling point where the metal support makes a complete turn, the dope film (web) (Also referred to as)) from the metal support. 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 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.

In the present invention, regarding the contents and casting of each layer, the following constitutions are particularly preferable. That is, the cellulose acylate solution is a cellulose acylate solution containing at least one liquid or solid plasticizer in an amount of 0.1 to 20 mass% with respect to the cellulose acylate at any temperature, and / or A cellulose acylate solution containing at least one liquid or solid ultraviolet absorber in an amount of 0.001 to 5 mass% with respect to the cellulose acylate, and / or at least one solid having an average particle size of 5 Fine particle powder having a particle size of ˜3000 nm is 0.001 to 5% by mass relative to cellulose acylate.
It is a cellulose acylate solution containing, and / or a cellulose acylate solution containing 0.001 to 2 mass% of at least one fluorine-based surfactant with respect to cellulose acylate, and And / or a cellulose acylate solution containing 0.0001 to 2% by mass of at least one releasing agent with respect to the cellulose acylate, and / or at least one deterioration inhibitor with respect to the cellulose acylate. 0.0001
To 2% by mass, and / or at least one optical anisotropy control agent is added to the cellulose acylate in an amount of 0.1 to 15%.
% By weight, and / or at least one infrared absorber is contained in an amount of 0.1 to 5 relative to cellulose acylate.
It is preferably a cellulose acylate solution containing mass%.

Furthermore, in the cellulose acylate solution and the cellulose acylate film, which are made up of a manufacturing step of simultaneously or successively co-casting two or more kinds of cellulose acylate solutions in the casting step, the chlorine-based solvent of each layer is used. The composition is the same or different, the additive in each layer is one kind or a mixture of two or more kinds, the addition position of the additive to each layer is Either the layers are the same layer or different layers, the concentration of the additive in the solution is the same or different in each layer, and the molecular weight of the aggregates in each layer is the same. Or the molecular weight of different aggregates, the temperature of the solution of each layer is the same or different, and the coating of each layer. Either the coating amount is the same or different, the viscosity of each layer is the same or different, and the film thickness after drying of each layer is the same or different. That the materials present in each layer have the same state or distribution or different states or distributions, and that the physical properties of each layer are either the same or different,
It is also preferable that the physical properties of each layer are either uniform or have different physical property distributions. Here, the physical properties include the physical properties described in detail on pages 6 to 7 of JIII Journal of Technical Disclosure (Kogi Gi No. 2001-1745, published on Mar. 15, 2001, JIII). For example, haze, transmittance, spectral characteristics, retardation Re, Rth, molecular orientation axis, axial deviation, tear strength, folding endurance, tensile strength, winding Rt difference inside and outside, crease, dynamic friction, alkaline hydrolysis, curl value, water content. Rate, residual solvent amount, heat shrinkage rate, high humidity dimension evaluation,
It includes moisture permeability, flatness of the base, dimensional stability, heat shrinkage initiation temperature, elastic modulus, measurement of bright spot foreign matter, and also includes impedance and surface condition used for evaluation of the base. In addition, the Technical Bulletin published by the Invention Association
2001-1745, published by Mar. 15, 2001, Institute of Invention, page 11 of cellulose acylate, in which the yellow index, transparency, and thermophysical properties (T
g, heat of crystallization) and the like.

In the present invention, the casting speed is 5 to 200 m / min, and / or the cellulose acylate film solution after casting is peeled from the metal support and immediately after that, the solution is adhered to the metal support side. Contacting the side of the film with the first roll and subsequently the side of the web that was on the air side of the metal support to the second roll and then drying, and / or first contacting The diameter of the roll becomes smaller toward the center of the roll, or the second roll is such that the diameter becomes larger toward the center of the roll, and And / or the dried winding shape is in a roll shape and has a length of 50 m to 10000 m, and / or the dried winding shape is in a roll shape and has a length of 5
It is preferable that the length is 0 m to 10000 m, and / or the widthwise length thereof is 30 cm to 500 cm, and / or both ends thereof are knurled at a height of 1 μm to 1 mm.

When the produced cellulose acylate film is a cellulose acylate film which is used as an optical protective layer, the film thickness is preferably 10 to 500 μm, and it is a support for silver halide photographic light-sensitive material. When used as a body, the film thickness is 30 to 250
It is preferably μm.

The cellulose acylate film can be improved in adhesion between the cellulose acylate film and each functional layer (for example, an undercoat layer and a back layer) by optionally performing a surface treatment. 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. To be Details of these are disclosed in the Technical Bulletin for Invention
001-1745, published by Mar. 15, 2001, Institute of Invention), pages 30 to 32. In the plasma treatment at atmospheric pressure, which has been attracting attention in recent years, for example, irradiation energy of 20 to 500 Kgy is used under 10 to 1000 Kev, and more preferably 30 to 500.
Irradiation energy of 20-300 Kgy under Kev is used. Of these, the alkali saponification treatment is particularly preferable and is extremely effective as the surface treatment of the cellulose acylate film.

The alkali saponification treatment is carried out by applying a saponification solution. Examples of the coating method include a dip coating method, a curtain coating method, an extrusion coating method, a bar coating method and an E-type coating method. The solvent of the alkali saponification treatment coating liquid is
It is preferable to select a solvent which has good wettability for applying the saponification solution to the transparent support and which keeps the surface state good without forming irregularities on the surface of the transparent support by the solvent of the saponification solution. Specifically, alcohol solvents are preferable, and isopropyl alcohol is particularly preferable. Also, an aqueous solution of a surfactant can be used as a solvent.
The alkali of the coating solution for alkali saponification is preferably an alkali soluble in the above solvent, more preferably KOH or NaOH. The pH of the saponification coating solution is preferably 10 or more, more preferably 12 or more. The reaction conditions during alkali saponification are preferably 1 second or more and 5 minutes or less at room temperature, more preferably 2 seconds or more and 1 minute or less, and particularly preferably 3 seconds or more and 30 seconds or less. After the alkali saponification reaction, the surface coated with the saponification solution is preferably washed with water. In addition, coating-type saponification treatment and alignment film de-coating described later,
It can be performed continuously, and the number of steps can be reduced.

In order to achieve the adhesion between the film and the emulsion layer, a method of surface-activating and then directly coating 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 a functional layer is applied thereon. For details of these undercoat layers, refer to the Japan Institute of Invention and Innovation Technical Report (Kogi No. 2001-174).
5, Issued March 15, 2001, Institute of Invention), page 32. Also, regarding the functional layers of the cellulose acylate film of the present invention, various functional layers are disclosed in the Technical Bulletin of the Institute of Invention (Kogi No. 2001-1745, published on March 15, 2001, Institute of Invention), pages 32 to 45. Are described in detail in.

The application of the cellulose acylate produced in the present invention will be briefly described first. The optical film of the present invention is particularly useful 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 dipped 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,
You may perform easy adhesion processing as described in Unexamined-Japanese-Patent No. 6-118232. As the adhesive used to bond the protective film-treated surface and the polarizer, for example,
Examples thereof include polyvinyl alcohol-based adhesives such as polyvinyl alcohol and polyvinyl butyral, and vinyl-based latex such as butyl acrylate. The polarizing plate is composed of a polarizer and a protective film that protects both sides of the polarizer,
Further, a protective film is attached to one surface of the polarizing plate, and a separate film is attached to the other surface. Protect film and separate film are
Used to protect the polarizing plate during 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. Further, 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, since a transparent hard coat layer, an antiglare layer, an antireflection layer, etc. 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 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
Nematic), IPS (In-Plane Sw)
etching), FLC (Ferroelectric)
c Liquid Crystal), AFLC (An
ti-ferroelectric Liquid C
physical), OCB (optically com)
Penstory Bend), STN (Suppe
r Twisted Nematic), VA (Ver
Tally Aligned) and HAN (Hy
Various display modes such as bridge aligned 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
It may be used as a support of an optical compensation sheet of a TN type liquid crystal display device having a mode liquid crystal cell. The cellulose acylate film of the invention may be used as a support of 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-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 product (△ nd) is 30
It is in the range of 0 to 1500 nm. Regarding the optical compensation sheet used in the STN type liquid crystal display device, see JP-A 2000-1
It is described in Japanese Patent No. 05316. The cellulose acylate film of the present invention is a V having a VA mode liquid crystal cell.
It is particularly advantageously used as a support for an optical compensation sheet of an A type liquid crystal display device. The cellulose acylate film of the present invention is an OCB type liquid crystal display device having an OCB mode liquid crystal cell or an HA having a HAN mode liquid crystal cell.
It is also advantageously used as a support for an optical compensation sheet of an N-type liquid crystal display device.

The cellulose acylate film of the present invention is TN type, STN type, HAN type, GH (Guest-type).
It is also advantageously used as an optical compensation sheet for a (Host) type reflective liquid crystal display device. These display modes have long been well known. Regarding the TN reflective liquid crystal display device, JP-A-10-123478 and WO984832
No. 0 and Japanese Patent No. 3022477 have descriptions.
The optical compensation sheet used for the reflective liquid crystal display device is described in WO00-65384. The cellulose acylate film of the present invention has an ASM (Axial)
y Symmetric Aligned Micro
It is also advantageously used as a support for an optical compensation sheet of an ASM type liquid crystal display device having a cell) mode liquid crystal cell. 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.
et al. , SID 98 Digest 108
9 (1998)). The applications of these detailed cellulose acylate films described above are disclosed in JIII Journal of Technical Disclosure (Jpn. Pat. No. 2001-1745, 200).
Invention Society, published March 15, 1), pages 45-59. Specific embodiments of the cellulose acylate of the invention are described below, but the invention is not limited thereto.

[0047]

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 removed from the support was visually observed, and the unpeeled film 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 on the film. B: Horizontal unevenness was slightly observed on the film. C: Lateral unevenness was considerably observed on the film. D: A large amount of horizontal unevenness was observed on the film.

(3) Hard spots on film (abbreviated as hard spots) The obtained films were visually observed and the hard spots on the surface were evaluated as follows. A: No spots were found on the film surface. B: A few spots were observed on the film surface. C: Significant spots were recognized 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 by using a haze meter (1001DP type, manufactured by Nippon Denshoku Industries Co., Ltd.).

Examples will be given below.
It is not limited to. Example 1 (1-1) Preparation of cellulose acylate solution It has a stirring blade and has a 500-liter stage where cooling water circulates around the periphery.
In a non-soluble dissolution tank, mix well with the following solvent mixture solution
-While dispersed, the cellulose acylate powder described in Table 1
(Flake) is gradually added, and the total amount becomes 200 kg.
I prepared it. The solvent, methylene chloride
And butanol, acetone, methanol, ethanol
All of them have a water content of 0.2% by mass or less
It was First, cellulose triacetate powder
The powder is put into the tank and the pressure inside the tank is reduced to 1300 Pa.
Then, the stirring shear rate is initially 15 m / sec (shear stress 5
× 10 ^Fourkgf / m / sec²) Diso stirring at the peripheral speed
Ruber type eccentric stirring shaft and anchor blade on the central shaft
With a peripheral speed of 1 m / sec (shear stress 1 × 10^Fourkgf
/ M / sec²) Disperse for 30 minutes under stirring conditions
It was The starting temperature of dispersion is 25 ° C, and the temperature of
The final temperature reached 35 ° C because the cooling water was run.
became. After the dispersion is completed, the high speed stirring is stopped and the anchor blade
Stir for 100 minutes at a peripheral speed of 0.5 m / sec.
Then, the cellulose triacetate flakes were swollen.
Until the end of swelling, the inside of the tank was adjusted to 0.12 MPa with nitrogen gas.
It was pressurized so that At this time, the oxygen concentration in the tank is 2
It was less than vol% and kept in a good condition for explosion protection.
Also, the water content in the dope should be 0.2% by mass or less.
confirmed. The composition of the cellulose acylate solution is as follows.
It is Ri.

Cellulose triacetate (degree of substitution 2.8
2, viscosity average degree of polymerization 320, water content 0.2 mass%, viscosity of 6 mass% in methylene chloride solution 305 mPa.
s, average particle diameter 1.5 mm, standard deviation 0.5 mm
The amount of addition is shown in Table 1), dichloromethane (58 parts by weight), acetone (5 parts by weight), methanol (6 parts by weight), isopropanol (4 parts by weight), butanol (the addition amount is shown in Table 1). Description), 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 parts by mass) ) And citric acid monoethyl ester (0.04 parts by mass) were used. Further, the cellulose triacetate used here has a residual acetic acid content of 0.1 mass% or less, Ca of 0.05 mass% and 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. In addition, the acetone extract is 11
The mass% and the ratio of the weight average molecular weight to the number average molecular weight were 0.5, and the distribution was uniform. Haze is 0.0
8, 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 35 ° 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 35 ° C.
It was cast on a mirror-finished stainless steel support, which was a drum having a diameter of 3 m, through a casting caster. The substrate temperature was -10 ° C, the casting speed was 80 m / min, and the coating width was 150 c.
m. The drying was performed by blowing dry air at 45 ° C. After 8.5 seconds, the drum type mirror surface stainless steel support was peeled off (the solid content concentration immediately after the peeling was about 20 to 70% by mass).
, Then 110 ° C, 5 minutes, then 130 ° C.
It was dried for 10 minutes (the film temperature was about 130 ° C.) to obtain a cellulose triacetate film (film thickness 80 μm).

(1-4) Results Table 1 shows the evaluation results of the obtained samples. The weight fraction of molecules or aggregates with a particle size of 100 nm or more, the number of associations is 5
The above weight fraction of the aggregates and the abundance ratio of the aggregates are not regulated by the solution concentration or the solution temperature, but in Table 1, the values at 0.5% by mass and 25 ° C. are shown as a representative.

[0057]

[Table 1]

Comparative Sample 1-10, in which no molecules or aggregates having a particle size of 100 nm or more are present, and no aggregates having an association number of 5 or more are present, peeling residue is remarkably generated, and unevenness and haze are greatly inferior. Met. Further, Comparative Sample 1-11, which had a low solution concentration of cellulose acylate and was outside the range of the present invention, also had significantly poor peeling residue and poor unevenness and haze. Comparative Sample 1-12, in which the solution concentration of the cellulose acylate was high and outside the range of the present invention, had very bad spots, an extremely bad surface condition, and bad haze. SA which represents a substituent of an acyl group substituted by a hydroxyl group of cellulose, SA
(Substitution degree of acetyl group), and SB (3 to 2 carbon atoms)
Comparative Sample 1-13 having a value of (degree of substitution of acyl group of 2) outside the range of the present invention was unpeeled, uneven, bad, and poor in surface condition. On the other hand, Samples 1-1 to 1-9 of the present invention
Was excellent in surface condition with no peeling residue, no unevenness, no spots, and little haze.

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

The non-uniform gel-like solution obtained from the above-mentioned cellulose triacetate film solution (1-2) was sent by a screw pump and passed through a heating part heated at 140 ° C. and 1 Mpa for 3 minutes. After 110 ℃, 1Mp
It is heated and pressurized to a, 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 0.0025 mm (manufactured by Pall Ltd., FH02).
It was filtered in 5).

(2-1) The sample 2-4 of the present invention obtained as a result had good filterability, no peeling residue, and excellent unevenness, spots and haze.
From this, it was confirmed that in the present invention, a cellulose acetate solution and a cellulose acetate film which are excellent in high temperature and high pressure dissolution can be produced. The weight fraction of molecules or aggregates having a particle size of 100 nm or more in the dilute solution of the cellulose acylate solution of Sample 2-4 was 90.
%, The weight fraction of those with 5 or more meetings is 91%, and the number of meetings is 5
It was confirmed that the above-mentioned existence number of aggregates was 84%.

Example 3 Sample 3-3 of the present invention was prepared in exactly the same manner as in Example 1 except that the plasticizers A and B were both removed in an amount of 0 parts by weight. The obtained sample 3-3 had no peeling residue, and both unevenness and spots were A, and haze was 0.
3 was excellent. On the other hand, when the folding endurance test was carried out, the sample 1-3 showed 125 times, whereas the sample 3-3, which is within the scope of the present invention and does not contain a plasticizer, has a cutting resistance test of 106 times, which is not a practical problem. 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 is evaluated by the sample 120 m.
The m × 120 mm was conditioned at 23 ° C., 65% RH for 2 hours, and evaluated by measuring the number of reciprocations until it was cut by bending in accordance with ISO8776-1988. In addition,
In a dilute solution of the cellulose acylate solution of Sample 3-3,
The weight fraction of molecules or aggregates with a particle size of 100 nm or more is 62.
%, The weight fraction of those with 5 or more meetings is 61%, and the number of meetings is 5
It was confirmed that the above-mentioned existence number of aggregates was 16%.

Example 4 In Example 1 except that the UV agents a, b and c were all removed as 0 parts by weight in the sample 1-6 of Example 1. Sample 4-6 of the present invention was manufactured in exactly the same manner as 1. Obtained Sample 4-
No. 6 had no peeling residue, unevenness and spots were evaluation A, and haze was 0.2, which was excellent. On the other hand, when the photo-fading test was carried out for 1 month for a xenon lamp of 20,000 lux, the haze of Sample 1-6 was 0.5%, whereas the haze of Sample 4-6 was within the scope of the present invention. Was slightly increased to 0.8. Therefore, in the present invention, it is clear that the cellulose acylate film containing a UV agent is a more preferable embodiment. In the dilute solution of the cellulose acylate solution of Sample 4-6, the weight fraction of molecules or aggregates having a particle size of 100 nm or more was 55%, the weight fraction of those having 5 or more associations was 73%, and the number of associations was 5 or more. It was confirmed that the abundance ratio of the aggregates was 18%.

Example 5 Sample 5-4 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 weight in Sample 1-4 of Example 1. The obtained sample 5-4 had no peeling residue, unevenness and spots were evaluated as A, and haze was 0.
3 was excellent. On the other hand, when two sheets of the film were stacked and examined for slipperiness, Sample 1-4 was able to smoothly move the two sheets, whereas Sample 5-4, which is within the scope of the present invention, shows a difference between the films. The movement was a little bad. Therefore, in the present invention, it is apparent that the cellulose acylate film containing fine particles is a more preferable embodiment. In the dilute solution of the cellulose acylate solution of Sample 5-4, the weight fraction of molecules or aggregates having a particle size of 100 nm or more was 93%, the weight fraction of those having 5 or more associations was 92%, and the number of associations was 5 or more. The number of aggregates present is 96
It was confirmed to be%.

Example 6 In Example 1-1 of the invention of Example 1, except that the production of the (1-2) cellulose triacetate film of Example 1 was changed as follows. A cellulose triacetate film of Sample 6-1 of the present invention was produced in exactly the same manner as in 1. That is, a part of the cellulose triacetate solution obtained in (1-1) was sampled, and a cellulose triacetate solution (solution A) diluted with 10% by mass of dichloromethane was prepared. The resulting solution is
According to the co-casting method described in JP-A 06-134993, the cellulose triacetate solution of Sample 1-5 was co-cast on the inside and the cellulose triacetate solution (solution A) on both sides thereof to form a co-cast cellulose triacetate film. Obtained. The film thickness was set to 3 μm on both sides and 34 μm inside so that the total thickness was 40 μm.
The surface condition of the obtained sample 6-1 was more excellent than that of sample 1-1, with a smoother surface and no unevenness. Therefore, it is apparent that co-casting is an even more excellent mode in the present invention. In the dilute solution of the cellulose acylate solution of Sample 6-1, the weight fraction of molecules or aggregates having a particle size of 100 nm or more is 5%, the weight fraction of those having an association number of 5 or more is 65%, the association number of 5 or more. The number of aggregates present is 19
It was confirmed to be%.

Example 7 In [Example 1] of JP-A No. 11-316378, the first transparent support was used as an example of the present invention. Example 1 of JP-A-11-316378 was carried out in exactly the same manner except that the thickness of the cellulose triacetate film (second film) obtained in Sample 1-1 of 1 was changed to 100 μm. Sample 7-1 was produced. The obtained elliptically polarizing plate had excellent optical characteristics. Therefore, it is clear that by using a specific washing solution in the production process of the present invention, a cellulose acylate film produced thereafter is a preferable mode in which there is no problem even if it is applied to an optical polarizing plate.

Example 8 A special feature was obtained except that the cellulose triacetate manufactured by Fuji Photo Film Co., Ltd. of Example 1 of JP-A-7-333433 was changed to the cellulose triacetate film of Sample 1-2 of the present invention of Example 1. An optical compensation filter film sample was prepared in exactly the same manner as in Example 1 of Kaihei 7-333433. The obtained filter film had an excellent viewing angle on the left, right, top and bottom. Therefore, it can be seen that the cellulose triacetate film of the present invention is excellent for optical use.

Example 9 The present invention is further used in various optical applications, and as a representative of the present invention, Sample 1-7 is used, for example, Japanese Patent Laid-Open No. 10-4842.
No. 0 liquid crystal display device described in Example 1, JP-A-9-26
572, an optically anisotropic layer containing discotic liquid crystal molecules described in Example 1, an alignment film coated with polyvinyl alcohol, a VA liquid crystal display device described in FIGS. 2 to 9 of JP-A-2000-154261, Japanese Patent Laid-Open No. 2000-15426
When used in the OCB type liquid crystal display device shown in FIGS. 10 to 15 of No. 1, good performance was obtained.

Example 10 Sample 10-5 of the invention, which is a film, was prepared in exactly the same manner as in Example 1 except that the film thickness of the sample 1-5 of the invention of Example 1 was 120 μm. It was made. On one side of the obtained film, JP-A-4-73736
(Back layer composition) of Example 1 of No. 1 was applied to prepare a back layer having a cationic polymer as a conductive layer. Further, sample 105 of Example 1 of JP-A No. 11-38568 was coated on the opposite surface of the obtained film base provided with a back layer to prepare a silver halide color photographic light-sensitive material. The color film obtained had excellent images and was easy to handle.

Example 11 The same procedure as in Example 1 except that the butanol was changed to isopropanol and the amount thereof was changed to 8 parts by mass in Sample 1-3 of the present invention of Example 1 Inventive Sample 11-3 was made. Obtained Sample 11-
No. 3 was unpeeled residue A, unevenness A and spot A, and haze was also small at 0.3, which was excellent in all respects. In the dilute solution of the cellulose acylate solution of Sample 11-3, the weight fraction of molecules or aggregates having a particle size of 100 nm or more was 62%, the weight fraction of those having 5 or more associations was 60%, and the number of associations was 5 or more. It was confirmed that the abundance ratio of aggregates was 15%.

Example 12 In the sample 1-6 of the present invention of Example 1, cellulose triacetate (15 parts by mass) and cellulose acetate propionate (acetyl substitution degree 2.45, propionate substitution degree 0.25) were used. The total degree of substitution is 2.70, the viscosity average degree of polymerization is 320, and the water content is 0.3.
Mass%, viscosity of 6 mass% in methylene chloride solution 2
75 mPa · s, powder having an average particle diameter of 1.3 mm and standard deviation of 0.4 mm, residual acetic acid amount and propionic acid amount are both 0.05% by mass or less, Ca is 0.012% by mass, and Mg is 0 0.07% by mass, Fe at 5 ppm, 6-position acetyl group and propionyl group at 0.70 and 0.1, respectively.
7 and 33% of all substituents, 7% by mass of acetone extracted, the ratio of the weight average molecular weight to the number average molecular weight is 0.9, the yellowness index is 1.3, the haze is 0.2, and the transparency is 93. 6%, Tg 157 ° C., crystallization heat value 4.
3 J / g) (5 parts by mass), and cellulose acetate butyrate (acetyl substitution degree 2.39, butyrate substitution degree 0.45, total substitution degree 2.84, viscosity average degree of polymerization 34).
0, water content 0.4% by mass, 6 in methylene chloride solution
Mass% viscosity 295 mPa · s, average particle size 1.3 m
m and a standard deviation of 0.4 mm, the amount of residual acetic acid and the amount of butanoic acid are both 0.03 mass% or less, 0.005 mass% Ca, 0.004 mass% Mg, and 5 Fe.
ppm, 6-position acetyl group and butyroyl group are 0.72 and 0.20 respectively, 32% of all substituents, acetone extracted 14% by weight, ratio of weight average molecular weight to number average molecular weight is 1.3, yellow Ness index is 0.9, haze is 0.5, transparency is 92.9%, Tg is 153 ° C., and crystallization calorific value is 3.9 J / g) (5 parts by mass) The film, Sample 12-6 of the present invention, was prepared in exactly the same manner as in Example 1. Obtained Sample 12-
No. 6 was unpeeled residue A, unevenness A and spot A, and haze value was 0.3, which was small and excellent in all respects. Therefore, in the present invention, an excellent cellulose acylate film can be obtained even if two or more kinds of cellulose acylate are mixed and used. In the dilute solution of the cellulose acylate solution of Sample 12-6, the weight fraction of molecules or aggregates having a particle size of 100 nm or more was 59%, the weight fraction of those having 5 or more associations was 77%, and the number of associations was 5 or more. The number of existing aggregates is 2
It was confirmed to be 2%.

[0072]

Industrial Applicability According to the present invention, there is provided a solution having good peelability even at high speed when the cellulose acylate film is peeled off after being cast on the support of the cellulose acylate solution in the production process. Can be done. Furthermore, the cellulose acylate film solution of the present invention can provide a cellulose acylate film 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) // B29K 1:00 B29K 1:00 B29L 7:00 B29L 7:00 C08L 1:10 C08L 1:10 F term (reference) ) 2H023 FA01 2H049 BA02 BA06 BA25 BB33 BB51 BB62 BC09 BC14 BC22 4F070 AA02 AB09 AE28 BA02 BA03 CB05 CB11 CB12 4F071 AA09 AA81 AA88 AG34 AH19 BA02 BA03 BB02 BC01 4F205 AA01 AG01 GA22 GB02 GC02

Claims (6)

[Claims] 1. A method for producing a cellulose acylate film, which comprises casting a cellulose acylate solution into a film,
Cellulose acylate solution is a chlorine-based organic solvent (chlorine-based organic solvent is at least 50% by mass or more of all organic solvents)
15 to 30% by mass of cellulose acylate is dissolved in the solution consisting of, and the weight fraction of the cellulose acylate molecule or aggregate having a particle size of 100 nm or more in the solution is 5%.
A method for producing a cellulose acylate film, characterized in that the content is -100%. 2. A method for producing a cellulose acylate film, which comprises casting a cellulose acylate solution into a film,
Cellulose acylate solution is a chlorine-based organic solvent (chlorine-based organic solvent is at least 50% by mass or more of all organic solvents)
15 to 30% by mass of cellulose acylate is dissolved and contained in the solution consisting of, and the weight fraction of the cellulose acylate aggregate having an association number of 5 or more in the solution is 5 to 100%. A method for producing an acylate film. 3. A method for producing a cellulose acylate film, which comprises casting a cellulose acylate solution into a film,
Cellulose acylate solution is a chlorine-based organic solvent (chlorine-based organic solvent is at least 50% by mass or more of all organic solvents)
A cellulose acylate containing 15 to 30% by mass of cellulose acylate dissolved in a solution consisting of 5 to 100%, and the presence ratio of aggregates of the cellulose acylate aggregate having an association number of 5 or more is 5 to 100%. Film manufacturing method. 4. The cellulose acylate is a cellulose acylate which is a cellulose acylate having a degree of substitution of a hydroxyl group of cellulose satisfying all of the following formulas (I) to (III), and is composed of a single or a mixture. The method for producing a cellulose acylate film according to any one of claims 1 to 3, characterized in that: (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 is the degree of substitution of the acetyl group, and SB is the degree of substitution of the acyl group having 3 to 22 carbon atoms. 5. The method for producing a cellulose acylate solution, wherein the cellulose acylate solution is obtained from at least one of the following preparation methods (i) to (iii). 2. The method for producing a cellulose acylate film according to Item 1. (I) A step of swelling at -10 to 40 ° C,
A method for preparing a cellulose acetate solution, which comprises the steps of heating to -40 ° C and dissolving cellulose acetate in a chlorine-based organic solvent. (Ii) a step of swelling at -10 to 40 ° C, -100 to -1
Cooling to 0 ° C., and cooling the cooled mixture from 0 to 57
A method for preparing a cellulose acetate solution, which comprises the step of heating cellulose acetate in a chlorine-based organic solvent by heating to 0 ° C. (Iii) Step of swelling at -10 to 40 ° C, 0.2 to 30
A preparation method comprising a step of heating at 60 to 240 ° C. at a high pressure and a high temperature with Mpa, and a step of cooling the heated mixture to 0 to 57 ° C. to dissolve cellulose acetate in a chlorine-based organic solvent. 6. A step of preparing a cellulose acylate solution by mixing cellulose acylate and a non-chlorine organic solvent, a step of filtering the resulting cellulose acylate solution, and a casting of the cellulose acylate solution on a support. 6. The step of stripping, the step of stripping, the step of drying to evaporate the solvent to form a film, and the step of winding the produced cellulose acylate film. Production method.