JP2006257204A - Cellulose ester film, method for producing the same, polarizing plate, retardation plate and optical display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a cellulose ester film in which display unevenness and change of visibility by humidity which occur when the film is built in a liquid crystal display device can be improved. <P>SOLUTION: The method for producing the cellulose ester film comprises melting a mixture of a cellulose ester satisfying each of the formula (S-1): 2.5≤A+B≤3.0, the formula (S-2): 0≤A≤2.2 and the formula (S-3): 0.8≤B≤3.0 (wherein A is a degree of substitution of acetyl group to hydroxyl group of cellulose; B is a degree of substitution of 3-22C acyl group to hydroxy group of cellulose) with a fluorine-based surfactant having a specific structure in an amount of 0.01-5 mass% based on solid content of the cellulose ester and forming the mixture into a film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a cellulose ester film by melt film formation. The present invention also relates to a cellulose ester film excellent in optical properties, a polarizing plate, a retardation plate and an optical display device using the same.

Conventionally, when producing a cellulose ester film used in a liquid crystal image display device, the cellulose ester is dissolved in a chlorinated organic solvent such as dichloromethane, and this is cast on a substrate and dried to form a film. The solution casting method is mainly implemented. Among the chlorinated organic solvents, dichloromethane is preferably used because it is a good solvent for cellulose acylate and has a low boiling point (about 40 ° C.), which makes it easy to dry in a film forming process and a drying process.
On the other hand, in recent years, from the viewpoint of environmental conservation, it has been strongly demanded to suppress discharge of organic solvents including chlorinated organic solvents. For this reason, a more strict closed system is adopted to prevent the organic solvent from leaking from the system, or even if it leaks from the system, the organic solvent is adsorbed through the gas absorption tower before being released to the outside air, or burned by thermal power Measures were taken so that almost no organic solvent was discharged by processing such as decomposing or decomposing with an electron beam. However, even if these measures were taken, no further non-emission was achieved, so further improvements were required.

As a countermeasure, a method of melt-forming cellulose ester has been developed as a film-forming method that does not use an organic solvent (Patent Document 1). In this method, the melting point is lowered to facilitate film formation by elongating the carbon chain of the ester group of the cellulose ester. Specifically, melt film formation is enabled by changing the cellulose acetate conventionally used to cellulose propionate, cellulose propionate, or the like. In addition, when a retardation film is produced using a conventional cellulose ester film as a substrate, there is also a problem that the visual field characteristics are likely to fluctuate with changes in humidity.
JP 2000-352620 A

However, when a polarizing plate is prepared by using the film formed by this method and incorporated in a liquid crystal display device, there is a problem that significant display unevenness occurs. In particular, the display unevenness in the longitudinal direction is large, and the display unevenness in the width direction is a level that needs to be improved. Such a failure is particularly prominent when incorporated in a large-sized liquid crystal display panel of 15 inches or more, and has been a big problem. This is because, in the process of forming a film by extruding a melt from a melt-kneader through a T-die (slit) onto a casting drum and solidifying by cooling, the die streaks appearing at the T-die are uneven in thickness in the width direction (TD). This is caused by unevenness in thickness in the longitudinal direction (MD) (horizontal dan) due to the close contact condition on the casting drum.
In view of these problems of the prior art, an object of the present invention is to provide a cellulose ester film that can improve display unevenness and visibility change due to humidity that occur when incorporated in a liquid crystal display device. . Furthermore, the present invention has conventionally used an organic solvent in the production of a cellulose ester film. However, it requires a great deal of time and management to cope with the environment at the time of operation and to recover the organic solvent. The goal is to improve significantly.

The above object of the present invention has been achieved by the present invention having the following constitution.
(Aspect 1)
The following general formulas (2A), (2B), (2C) and (2D) with respect to the cellulose ester satisfying the following formulas (S-1) to (S-3) and the solid content of the cellulose ester: A method for producing a cellulose ester film comprising a step of melt-forming a mixture of 0.01 to 5% by mass of a fluorosurfactant represented.
Formula (S-1) 2.5 <= A + B <= 3.0
Formula (S-2) 0 ≦ A ≦ 2.2
Formula (S-3) 0.8 ≦ B ≦ 3.0
(In the formula, A represents the substitution degree of the acetyl group to the hydroxyl group of cellulose, and B represents the substitution degree of the acyl group having 3 to 22 carbon atoms to the hydroxyl group of cellulose.)

General formula (2A)

In the formula, R ^A1 and R ^A2 each represent a substituted or unsubstituted alkyl group, and at least one of R ^A1 and R ^A2 represents an alkyl group substituted with a fluorine atom. R ^A3 , R ^A4 and R ^A5 each independently represent a hydrogen atom or a substituent, L ^A1 , L ^A2 and L ^A3 each independently represent a single bond or a divalent linking group, and X ⁺ represents a cationic substituent. Represents a group. Y ⁻ represents a counter anion, but Y ⁻ may not be present when the charge is 0 in the molecule. m ^A is 0 or 1.

式中、Ｒ^B3、Ｒ^B4およびＲ^B5はそれぞれ独立に水素原子または置換基を表す。ＡおよびＢはそれぞれ独立にフッ素原子または水素原子を表す。ｎ^B3およびｎ^B4はそれぞれ独立に４〜８のいずれかの整数を表す。Ｌ^B1およびＬ^B2はそれぞれ独立に、置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンオキシ基またはこれらを組み合わせてできる２価の連結基を表す。ｍ^Bは０または１を表す。Ｍはカチオンを表す。 General formula (2B)

In the formula, R ^B3 , R ^B4 and R ^B5 each independently represent a hydrogen atom or a substituent. A and B each independently represent a fluorine atom or a hydrogen atom. n ^B3 and n ^B4 each independently represents an integer of 4 to 8. L ^B1 and L ^B2 each independently represent a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkyleneoxy group, or a divalent linking group formed by combining these. m ^B represents 0 or 1. M represents a cation.

式中、Ｒ^C1は置換または無置換のアルキル基を表し、Ｒ^CFはパーフルオロアルキレン基を表す。Ａは水素原子またはフッ素原子を表し、Ｌ^C1は置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンオキシ基またはこれらを組み合わせてできる２価の連結基を表す。Ｙ^C1およびＹ^C2は、一方が水素原子を、もう一方が−Ｌ^C2−ＳＯ₃Ｍを表す。ここで、Ｌ^C2は単結合または置換もしくは無置換のアルキレン基を表し、Ｍはカチオンを表す。 General formula (2C)

In the formula, R ^C1 represents a substituted or unsubstituted alkyl group, and R ^CF represents a perfluoroalkylene group. A represents a hydrogen atom or a fluorine atom, and L ^C1 represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkyleneoxy group, or a divalent linking group formed by combining these. One of Y ^C1 and Y ^C2 represents a hydrogen atom, and the other represents -L ^C2 -SO ₃ M. Here, L ^C2 represents a single bond or a substituted or unsubstituted alkylene group, and M represents a cation.

General formula (2D)
[Rf ^D- (L ^D ) _nD ] _mD -W

In the formula, Rf ^D represents a perfluoroalkyl group, L ^D represents an alkylene group, W represents a group having an anionic group, a cationic group, a betaine group or a nonionic polar group necessary for imparting surface activity. To express. n ^D represents 0 or 1, and m ^D represents any integer of 1 to 3.

(Aspect 2)
A molten mixture (melt) of the cellulose ester and the fluorosurfactant represented by any one of the general formulas (2A), (2B), (2C) and (2D) is solidified on the casting drum, and then on the casting drum The cellulose ester film formed in 1 is peeled, the tension is cut with a nip roll, and the tension at the time of winding is 0.01 kg / cm ^{2 to} 10 kg / cm ² , and the film is wound (Aspect 1). A method for producing a cellulose ester film.
(Aspect 3)
When the molten mixture is solidified on the casting drum, cooling between (Tg + 30 ° C.) and Tg (where Tg is the glass transition temperature of the cellulose ester film) is performed at a rate of 10 ° C./second to 100 ° C./second (solidification rate). The method for producing a cellulose ester film according to (Aspect 1) or (Aspect 9), wherein

(Aspect 4)
A mixture of a cellulose ester and a fluorosurfactant represented by any one of the general formulas (2A), (2B), (2C) and (2D) is 180 ° C. to After melt | dissolving at 250 degreeC, it extrudes on a casting drum from T-die, The manufacturing method of the cellulose-ester film as described in (aspect 2) or (aspect 3) characterized by the above-mentioned.
(Aspect 5)
After extruding from the T-die, cooling between Tg and (Tg-20 ° C) is performed at a rate of 0.1 ° C / second to 20 ° C / second, and the cellulose ester according to (Aspect 4) Film production method.

(Aspect 6)
Any one of (Aspect 1) to (Aspect 5) is characterized by having a step of extending 1% to 500% in at least one direction (preferably in a casting direction or a direction orthogonal to the casting direction) after melt film formation. The method for producing a cellulose ester film according to claim 1.
(Aspect 7)
A cellulose ester film produced by the production method according to any one of (Aspect 1) to (Aspect 6).

(Aspect 8)
One of the general formulas (2A), (2B), (2C) and (2D) for the cellulose ester satisfying the following formulas (S-1) to (S-3) and the solid content of the cellulose ester A cellulose ester film comprising 0.01 to 5% by mass of a fluorine-based surfactant represented by the formula:
Formula (S-1) 2.5 <= A + B <= 3.0
Formula (S-2) 0 ≦ A ≦ 2.2
Formula (S-3) 0.8 ≦ B ≦ 3.0
(In the formula, A represents the substitution degree of the acetyl group to the hydroxyl group of cellulose, and B represents the substitution degree of the acyl group having 3 to 22 carbon atoms to the hydroxyl group of cellulose.)

式中、Ｒ^A1およびＲ^A2はそれぞれ置換もしくは無置換のアルキル基を表すが、Ｒ^A1およびＲ^A2の少なくとも１つはフッ素原子で置換されたアルキル基を表す。Ｒ^A3、Ｒ^A4およびＲ^A5はそれぞれ独立に水素原子または置換基を表し、Ｌ^A1、Ｌ^A2およびＬ^A3はそれぞれ独立に単結合または２価の連結基を表し、Ｘ⁺はカチオン性の置換基を表す。Ｙ^-は対アニオンを表すが、分子内で荷電が０になる場合にはＹ^-はなくてもよい。ｍ^Aは０または１である。 General formula (2A)

In the formula, R ^A1 and R ^A2 each represent a substituted or unsubstituted alkyl group, and at least one of R ^A1 and R ^A2 represents an alkyl group substituted with a fluorine atom. R ^A3 , R ^A4 and R ^A5 each independently represent a hydrogen atom or a substituent, L ^A1 , L ^A2 and L ^A3 each independently represent a single bond or a divalent linking group, and X ⁺ represents a cationic substituent. Represents a group. Y ⁻ represents a counter anion, but Y ⁻ may not be present when the charge is 0 in the molecule. m ^A is 0 or 1.

式中、Ｒ^B3、Ｒ^B4およびＲ^B5はそれぞれ独立に水素原子または置換基を表す。ＡおよびＢはそれぞれ独立にフッ素原子または水素原子を表す。ｎ^B3およびｎ^B4はそれぞれ独立に４〜８のいずれかの整数を表す。Ｌ^B1およびＬ^B2はそれぞれ独立に、置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンオキシ基またはこれらを組み合わせてできる２価の連結基を表す。ｍ^Bは０または１を表す。Ｍはカチオンを表す。 General formula (2B)

In the formula, R ^B3 , R ^B4 and R ^B5 each independently represent a hydrogen atom or a substituent. A and B each independently represent a fluorine atom or a hydrogen atom. n ^B3 and n ^B4 each independently represents an integer of 4 to 8. L ^B1 and L ^B2 each independently represent a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkyleneoxy group, or a divalent linking group formed by combining these. m ^B represents 0 or 1. M represents a cation.

式中、Ｒ^C1は置換または無置換のアルキル基を表し、Ｒ^CFはパーフルオロアルキレン基を表す。Ａは水素原子またはフッ素原子を表し、Ｌ^C1は置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンオキシ基またはこれらを組み合わせてできる２価の連結基を表す。Ｙ^C1およびＹ^C2は、一方が水素原子を、もう一方が−Ｌ^C2−ＳＯ₃Ｍを表し、Ｍはカチオンを表す。 General formula (2C)

In the formula, R ^C1 represents a substituted or unsubstituted alkyl group, and R ^CF represents a perfluoroalkylene group. A represents a hydrogen atom or a fluorine atom, and L ^C1 represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkyleneoxy group, or a divalent linking group formed by combining these. One of Y ^C1 and Y ^C2 represents a hydrogen atom, the other represents -L ^C2 -SO ₃ M, and M represents a cation.

General formula (2D)
[Rf ^D- (L ^D ) _nD ] _mD -W

In the formula, Rf ^D represents a perfluoroalkyl group, L ^D represents an alkylene group, W represents a group having an anionic group, a cationic group, a betaine group or a nonionic polar group necessary for imparting surface activity. To express. n ^D represents 0 or 1, and m ^D represents any integer of 1 to 3.

(Aspect 9)
The acyl group having 3 to 22 carbon atoms substituted for the hydroxyl group of cellulose is one or more acyl groups selected from the group consisting of propionyl group, butyryl group, pentanoyl group and hexanoyl group. The cellulose ester film according to any one of (Aspect 7) to (Aspect 8).
(Aspect 10)
In any one of (Aspect 7) to (Aspect 9), the in-plane retardation (Re) is 0 ≦ Re ≦ 200 nm, and the thickness direction retardation (Rth) is −200 ≦ Rth ≦ 500 nm. The cellulose ester film according to claim 1.

(Aspect 11)
The cellulose ester film according to any one of (Aspect 7) to (Aspect 10), wherein the thickness unevenness of the cellulose ester film is 0% to 2%.
(Aspect 12)
The cellulose ester film according to any one of (Aspect 7) to (Aspect 11), wherein the contact angle of water on the film surface is 45 ° or less (25 ° C./relative humidity 60%).

(Aspect 13)
The cellulose ester film according to any one of (Aspect 7) to (Aspect 12), wherein the cellulose ester satisfies the following formulas (S-4) to (S-6).
Formula (S-4) 2.6 ≦ A + B ′ ≦ 3.0
Formula (S-5) 0 ≦ A ≦ 1.8
Formula (S-6) 1.2 ≦ B ′ ≦ 3.0
(In the formula, A represents the degree of substitution of the acetyl group with respect to the hydroxyl group of cellulose, and B ′ represents the total degree of substitution of the propionyl group, butyryl group, pentanoyl group, and hexanoyl group with respect to the hydroxyl group of cellulose.)

(Aspect 14)
An optical polarizing plate characterized by laminating at least one layer of the cellulose ester film according to any one of (Aspect 7) to (Aspect 13) on a polarizing film (in the present specification, simply referred to as a polarizing plate). is there).
(Aspect 15)
The optical polarizing plate according to (Aspect 14), wherein the polarizing film is tenter-stretched in a direction substantially 45 ° with respect to the longitudinal direction.

(Aspect 16)
An optical compensation film (retardation plate), wherein the cellulose ester film according to any one of (Aspect 7) to (Aspect 15) is used as a base material.
(Aspect 17)
(Aspect 7) -An antireflection film characterized by using the cellulose ester film according to any one of (Aspect 16) as a substrate.
(Aspect 18)
(Aspect 7) An optical display device produced using the cellulose ester film according to any one of (Aspect 13).
(Aspect 19)
(Aspect 14) A liquid crystal display using the optical polarizing plate according to (Aspect 15), the optical compensation film according to (Aspect 16), or the antireflection film according to (Aspect 17). apparatus.

  According to the production method of the present invention, it is possible to provide a cellulose ester film in which thickness unevenness and optical property unevenness are greatly reduced. In addition, improvements in scratch resistance and dust prevention were seen, and unexpected effects could be obtained. Furthermore, if a liquid crystal display device is manufactured by incorporating the cellulose ester film of the present invention, changes in optical properties due to display unevenness and humidity can be suppressed. Furthermore, the present invention was able to greatly improve the environmental response during work in the production of a cellulose ester film.

BEST MODE FOR CARRYING OUT THE INVENTION

  Below, the cellulose-ester film of this invention and its manufacturing method are demonstrated in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

<Cellulose ester>
(Cellulose ester)
The cellulose ester used in the present invention satisfies the following formulas (S-1) to (S-3).
Formula (S-1) 2.5 <= A + B <= 3.0
Formula (S-2) 0 ≦ A ≦ 2.2
Formula (S-3) 0.8 ≦ B ≦ 3.0
(In the formula, A represents the substitution degree of the acetyl group to the hydroxyl group of cellulose, and B represents the substitution degree of the acyl group having 3 to 22 carbon atoms to the hydroxyl group of cellulose.)

  The glucose unit which comprises cellulose and has a beta (β) -1,4 bond has free hydroxyl groups at the 2nd, 3rd and 6th positions. The cellulose ester is a polymer (polymer) obtained by esterifying some or all of these hydroxyl groups. The degree of acyl substitution means the sum of the ratios of esterification of cellulose for each of the 2-position, 3-position and 6-position (100% esterification has a substitution degree of 1). In the present invention, 2.6 ≦ A + B ≦ 3.0 is more preferable, and 2.67 ≦ A + B ≦ 2.97 is more preferable. Preferably, A is 0 ≦ A ≦ 1.4, B is preferably 1.3 ≦ B ≦ 2.97, and more preferably 1.4 ≦ B ≦ 2.97. In the present invention, the substitution degree of the hydroxyl groups at the 2nd, 3rd and 6th positions of the cellulose is not particularly limited, but the substitution degree at the 6th position of the cellulose ester is preferably 0.7 or more, more preferably 0.8. It is above, Especially preferably, it is 0.85 or more. By these, the solubility and heat resistance of cellulose ester can be improved.

  Next, the C3-C22 acyl group represented by the substituent B of the cellulose ester of the present invention may be either an aliphatic acyl group or an aromatic acyl group. When the acyl group of the cellulose ester of the present invention is an aliphatic acyl group, the number of carbon atoms is preferably 3-18, more preferably 3-12, and the number of carbons is 3-8. It is particularly preferred. Examples of these aliphatic acyl groups include an alkylcarbonyl group, an alkenylcarbonyl group, and an alkynylcarbonyl group. When the acyl group is an aromatic acyl group, the carbon number is preferably 6-22, more preferably 6-18, and particularly preferably 6-12. Each of these acyl groups may further have a substituent.

  Examples of preferred acyl groups include propionyl, butanoyl, pentanoyl, hexanoyl, heptanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, Examples thereof include an isobutyryl group, a pivaloyl group, a cyclohexanecarbonyl group, an oleoyl group, a benzoyl group, a naphthalenecarbonyl group, a phthaloyl group, and a cinnamoyl group.

  The acyl group constituting the ester of the cellulose ester of the present invention is more preferably an aliphatic acyl group having 6 or less carbon atoms, selected from the group consisting of an acetyl group, a propionyl group, a butyryl group, a pentanoyl group, and a hexanoyl group. One or more acyl groups are preferred. More preferred is one or more acyl groups selected from the group consisting of an acetyl group, a propionyl group, a butyryl group and a pentanoyl group, and even more preferred is a group selected from the group consisting of an acetyl group, a propionyl group and a butyryl group. One or more acyl groups. The acyl group constituting the ester of the cellulose ester of the present invention may be a single species or a plurality of species.

  Further, the cellulose ester used in the present invention preferably satisfies 2.6 ≦ A + B ′ ≦ 3.0, 0 ≦ A ≦ 1.8, and 1.0 ≦ B ′ ≦ 3 (where A is Substitution degree of acetyl group, B ′ represents the sum of substitution degree of propionyl group, butyryl group, pentanoyl group and hexanoyl group). More preferably, the cellulose ester used in the present invention satisfies 2.6 ≦ A + B ′ ≦ 3.0, 0 ≦ A ≦ 1.4, and 1.2 ≦ B ′ ≦ 3. In particular, the cellulose ester used in the present invention preferably satisfies 2.7 ≦ A + B ′ ≦ 3.0, 0 ≦ A ≦ 1.0, and 1.7 ≦ B ′ ≦ 3. Thus, by reducing the content of acetyl groups and increasing the content of propionyl, butyryl, pentanoyl, and hexanoyl groups, it is possible to suppress changes in Re and Rth with respect to humidity when filmed.

(Method for producing cellulose ester)
Next, the manufacturing method of the cellulose ester of this invention is demonstrated. The more detailed raw material cotton and the synthesis method of the cellulose ester of the present invention are described in Invention Technical Journal (Public Technical Number 2001-1745, published on March 15, 2001, Invention Society), pages 7-12. . As the cellulose raw material, those derived from hardwood pulp, softwood pulp, and cotton linter are preferably used. As a cellulose raw material, it is preferable to use a high-purity material having an α-cellulose content of 92 mass% to 99.9 mass%. When the cellulose raw material is in the form of a sheet or a lump, it is preferable to pulverize in advance, and it is preferable that the pulverization of the cellulose form proceeds from a fine powder to a feather shape.

  Prior to acylation, the cellulose raw material is preferably subjected to a treatment (activation) in contact with an activator. As the activator, carboxylic acid or water can be used. However, when water is used, an excess of acid anhydride is added after activation to perform dehydration or to replace water. It is preferable to include a step of washing with an acid or adjusting acylation conditions. The activator may be added by adjusting to any temperature, and the addition method can be selected from spraying, dropping, dipping and the like. Preferred carboxylic acids as activators are carboxylic acids having 2 to 7 carbon atoms (for example, acetic acid, propionic acid, butyric acid, 2-methylpropionic acid, valeric acid, 3-methylbutyric acid, 2-methylbutyric acid, 2,2- Dimethylpropionic acid (pivalic acid), hexanoic acid, 2-methylvaleric acid, 3-methylvaleric acid, 4-methylvaleric acid, 2,2-dimethylbutyric acid, 2,3-dimethylbutyric acid, 3,3-dimethylbutyric acid, Cyclopentanecarboxylic acid, heptanoic acid, cyclohexanecarboxylic acid, benzoic acid, etc.), more preferably acetic acid, propionic acid, or butyric acid. In the activation, sulfuric acid or the like may be further added in an amount of 0.1% by mass to 10% by mass with respect to the cellulose.

  The addition amount of the activator is preferably 0.05 to 100 times by mass, more preferably 0.1 to 20 times by mass, and 0.3 to 20 times by mass with respect to the mass of cellulose. Is particularly preferred. The activation time is preferably 20 minutes to 72 hours, more preferably 30 minutes to 24 hours, and particularly preferably 30 minutes to 12 hours. The activation temperature is preferably 0 ° C to 90 ° C, more preferably 15 ° C to 80 ° C, and particularly preferably 20 ° C to 60 ° C. The step of activating cellulose can also be performed under pressure or reduced pressure. Moreover, you may use electromagnetic waves, such as a microwave and infrared rays, as a heating means.

  In the method for producing a cellulose ester in the present invention, it is preferable to acylate a hydroxyl group of cellulose by adding an acid anhydride of carboxylic acid to cellulose and reacting with Bronsted acid or Lewis acid as a catalyst. As a method of obtaining the cellulose ester of the present invention, a method of reacting two carboxylic acid anhydrides as an acylating agent by mixing or sequentially adding them, a mixed acid anhydride of two carboxylic acids (for example, acetic acid / propionic acid mixing) Acid anhydrides), mixed acid anhydrides (for example, acetic acid / propionic acid mixed acid anhydrides) in the reaction system using carboxylic acid and another carboxylic acid anhydride (for example, acetic acid and propionic acid anhydride) as raw materials Product) and a method of reacting with cellulose, a method of once synthesizing a cellulose ester having a degree of substitution of less than 3, and further acylating the remaining hydroxyl group using an acid anhydride or acid halide. .

  The acid anhydride of the carboxylic acid preferably has 2 to 7 carbon atoms as the carboxylic acid. For example, acetic anhydride, propionic anhydride, butyric anhydride, 2-methylpropionic anhydride, valeric anhydride, 3-methylbutyric anhydride, 2-methylbutyric anhydride, 2,2-dimethylpropionic anhydride (pivalic anhydride), hexanoic anhydride, 2-methylvaleric anhydride, 3-methylvaleric anhydride 4-methylvaleric anhydride, 2,2-dimethylbutyric anhydride, 2,3-dimethylbutyric anhydride, 3,3-dimethylbutyric anhydride, cyclopentanecarboxylic anhydride, heptanoic anhydride, cyclohexanecarboxylic acid An acid anhydride, a benzoic acid anhydride, etc. can be mentioned.

  More preferred are acetic anhydride, propionic anhydride, butyric anhydride, valeric anhydride, hexanoic anhydride, heptanoic anhydride and the like, and particularly preferred are acetic anhydride, propionic anhydride, butyric acid. Anhydrous. For the purpose of preparing a cellulose ester, it is preferable to use these acid anhydrides in combination. The mixing ratio is preferably determined according to the substitution ratio of the target cellulose ester. The acid anhydride is usually preferably added in an excess equivalent to the cellulose, more preferably 1.2 to 50 equivalents, and more preferably 1.5 to 30 equivalents to the hydroxyl group of the cellulose. Addition of 2 to 10 equivalents is particularly preferable.

  As the acylation catalyst used in the production of the cellulose ester in the present invention, it is preferable to use Bronsted acid or Lewis acid. The definitions of Bronsted acid and Lewis acid are described in, for example, “Physical and Chemical Dictionary”, 5th edition (2000). Examples of preferable Bronsted acid include sulfuric acid, perchloric acid, phosphoric acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid and the like. Examples of preferred Lewis acids include zinc chloride, tin chloride, antimony chloride, magnesium chloride and the like. As the catalyst, sulfuric acid or perchloric acid is more preferable, and sulfuric acid is particularly preferable. The preferable addition amount of a catalyst is 0.1-30 mass% with respect to a cellulose, More preferably, it is 1-15 mass%, Most preferably, it is 3-12 mass%.

  In carrying out acylation, a solvent may be added for the purpose of adjusting viscosity, reaction rate, stirring ability, acyl substitution ratio, and the like. As such a solvent, dichloromethane, chloroform, carboxylic acid, acetone, ethyl methyl ketone, toluene, dimethyl sulfoxide, sulfolane and the like can be used, but carboxylic acid is preferable, for example, a carboxylic acid having 2 to 7 carbon atoms. Acids {eg acetic acid, propionic acid, butyric acid, 2-methylpropionic acid, valeric acid, 3-methylbutyric acid, 2-methylbutyric acid, 2,2-dimethylpropionic acid (pivalic acid), hexanoic acid, 2-methylvaleric acid , 3-methylvaleric acid, 4-methylvaleric acid, 2,2-dimethylbutyric acid, 2,3-dimethylbutyric acid, 3,3-dimethylbutyric acid, cyclopentanecarboxylic acid} and the like. More preferably, acetic acid, propionic acid, butyric acid and the like can be mentioned. These solvents may be used as a mixture.

  When acylation is performed, an acid anhydride and a catalyst, and further, if necessary, a solvent may be mixed and then mixed with cellulose, or these may be separately mixed with cellulose. It is preferable to prepare a mixture of an acid anhydride and a catalyst or a mixture of an acid anhydride, a catalyst and a solvent as an acylating agent and then react with cellulose. In order to suppress an increase in temperature in the reaction vessel due to reaction heat during acylation, the acylating agent is preferably cooled in advance. The cooling temperature is preferably −50 ° C. to 20 ° C., more preferably −35 ° C. to 10 ° C., and particularly preferably −25 ° C. to 5 ° C. The acylating agent may be added in a liquid state or may be frozen and added as a crystal, flake or block solid.

  Further, the acylating agent may be added to the cellulose at once or dividedly. In addition, cellulose may be added to the acylating agent all at once or in divided portions. When the acylating agent is added in portions, the same acylating agent or a plurality of different acylating agents may be used. As a preferred example, 1) a mixture of acid anhydride and solvent is added first, then the catalyst is added, and 2) a mixture of part of acid anhydride, solvent and catalyst is added first, then the rest of the catalyst and Add solvent mixture 3) Add acid anhydride and solvent mixture first, then add catalyst and solvent mixture 4) Add solvent first, acid anhydride and catalyst mixture or acid For example, a mixture of an anhydride, a catalyst, and a solvent may be added.

  Although acylation of cellulose is an exothermic reaction, in the method for producing a cellulose ester of the present invention, the maximum temperature reached during acylation is preferably -50 ° C to 50 ° C, and the degree of polymerization can be easily controlled. Yes, preferably -30 ° C to 45 ° C, more preferably -20 ° C to 40 ° C, particularly preferably -20 ° C to 35 ° C. A preferable acylation time is 0.5 to 24 hours, more preferably 1 to 12 hours, and particularly preferably 1.5 to 6 hours.

  In the method for producing the cellulose ester used in the present invention, it is preferable to add a reaction terminator after the acylation reaction. The reaction terminator may be any as long as it decomposes the acid anhydride, and preferred examples include water, alcohol (eg, ethanol, methanol, propanol, isopropyl alcohol, etc.) or a composition containing these. be able to. When adding a reaction terminator, a large exotherm that exceeds the cooling capacity of the reactor may occur, which may cause the degree of polymerization of the cellulose ester to decrease, or the cellulose ester may precipitate in an undesired form. In order to avoid inconvenience, it is preferable to add a mixture of a carboxylic acid such as acetic acid, propionic acid, butyric acid and water rather than directly adding water or alcohol, and acetic acid is particularly preferable as the carboxylic acid. The composition ratio of carboxylic acid and water can be used at any ratio, but the water content is 5% by mass to 80% by mass, further 10% by mass to 60% by mass, and particularly 15% by mass to 50% by mass. It is preferable that it is the range of these.

  The reaction terminator may be added to the acylation reaction vessel or the reactant may be added to the reaction terminator vessel. The reaction terminator is preferably added over 3 minutes to 3 hours, more preferably 4 minutes to 2 hours, still more preferably 5 minutes to 1 hour, and particularly preferably 10 minutes to 45 minutes. When adding the reaction terminator, the reaction vessel may or may not be cooled, but for the purpose of suppressing depolymerization, it is preferable to cool the reaction vessel to suppress the temperature rise. It is also preferable to cool the reaction terminator.

  After the acylation is stopped, neutralizing agents (for example, calcium, magnesium, iron, aluminum) are used for hydrolysis of excess carboxylic anhydride remaining in the system and for neutralization of some or all of the esterification catalyst. Alternatively, zinc carbonate, acetate, hydroxide or oxide) or a solution thereof may be added. As a solvent for the neutralizing agent, water, alcohol (eg, ethanol, methanol, propanol, isopropyl alcohol, etc.), carboxylic acid (eg, acetic acid, propionic acid, butyric acid, etc.), ketone (eg, acetone, ethyl methyl ketone, etc.), Preferred examples include polar solvents such as dimethyl sulfoxide and mixed solvents thereof.

  The cellulose ester thus obtained has a total degree of substitution of cellulose hydroxyl groups close to about 3. However, for the purpose of obtaining a desired degree of substitution, a small amount of catalyst (generally, a residual acyl such as sulfuric acid) is obtained. The ester bond is partially hydrolyzed by keeping it at 20 to 90 ° C. for several minutes to several days in the presence of water and a catalyst, so that the cellulose ester has a desired degree of acyl substitution (so-called aging). ) Is generally performed. Since the cellulose sulfate ester is also hydrolyzed during the partial hydrolysis, the amount of sulfate ester bound to the cellulose can be reduced by adjusting the hydrolysis conditions.

  When the desired cellulose ester is obtained, it is preferable to completely neutralize the catalyst remaining in the system using the neutralizing agent or a solution thereof as described above to stop the partial hydrolysis. By adding a neutralizing agent (for example, magnesium carbonate, magnesium acetate, etc.) that generates a salt that is poorly soluble in the reaction solution, a catalyst (for example, sulfate ester) bound to the solution or to cellulose is effectively removed. It is also preferable to remove.

  For the purpose of removing or reducing unreacted substances, hardly soluble salts, and other foreign matters in the cellulose ester, it is preferable to filter the reaction mixture after acylation. Filtration may be performed in any step from completion of esterification to reprecipitation. For the purpose of controlling filtration pressure and handleability, it is also preferable to dilute with an appropriate solvent prior to filtration. In the case of filtration, the filter medium is not particularly limited, and cloth, glass filter, cellulose filter paper, cellulose cloth filter, metal filter, polymer filter (for example, polypropylene filter, polyethylene filter, polyamide filter, fluorine filter) Filter). The filter aperture size is preferably 0.1 to 500 μm, more preferably 2 to 200 μm, and further 3 to 60 μm.

  By mixing the obtained cellulose ester solution in a poor solvent such as water or an aqueous solution of carboxylic acid (for example, acetic acid, propionic acid, butyric acid, etc.) or by mixing the poor solvent in the cellulose ester reaction solution, The cellulose ester can be reprecipitated, and the desired cellulose ester can be obtained by washing and stabilizing treatment. By reprecipitation, the purification efficiency can be improved, and the molecular weight distribution and apparent density can be adjusted. Reprecipitation may be carried out continuously or batchwise by a fixed amount. It is also preferable to control the form and molecular weight distribution of the re-precipitated cellulose ester by adjusting the concentration of the cellulose ester solution and the composition of the poor solvent depending on the substitution pattern or degree of polymerization of the cellulose ester.

  The produced cellulose ester is preferably washed. The cleaning may be any one that can remove impurities, but usually water or warm water is used. The temperature of the washing water is preferably 5 ° C to 100 ° C, more preferably 15 ° C to 90 ° C, and particularly preferably 30 ° C to 80 ° C. The washing treatment may be performed by a so-called batch method in which filtration and replacement of the washing liquid are repeated, or may be carried out using a continuous washing apparatus. It is also preferable to reuse the waste liquid generated in the reprecipitation and washing steps as a poor solvent for reprecipitation, or to recover and reuse a solvent such as carboxylic acid by means such as distillation. The progress of washing may be traced by any means, but preferred examples include methods such as hydrogen ion concentration, ion chromatography, electrical conductivity, ICP, elemental analysis, and atomic absorption spectrum. By treatment, Bronsted acid (sulfuric acid, perchloric acid, trifluoroacetic acid, p-toluenesulfonic acid, methanesulfonic acid, etc.) in cellulose ester, neutralizing agent (for example, calcium, magnesium, iron, aluminum or zinc carbonate) Salt, acetate, hydroxide or oxide), reaction product of neutralizing agent and catalyst, carboxylic acid (acetic acid, propionic acid, butyric acid, etc.), reaction product of neutralizing agent and carboxylic acid, etc. It is effective for enhancing the stability of the cellulose ester (particularly, the decomposition of the ester bond due to high temperature and high humidity).

  The cellulose ester after washing by hot water treatment is weakly alkaline (for example, carbonates such as sodium, potassium, calcium, magnesium, aluminum, hydrogen carbonate, It is also preferable to treat with an aqueous solution of hydroxide, oxide, etc.). The amount of residual impurities can be controlled by the amount of cleaning liquid, cleaning temperature, time, stirring method, shape of cleaning container, composition and concentration of stabilizer.

  In the present invention, in order to adjust the water content of the cellulose ester to a preferable amount, it is preferable to dry the cellulose ester. The drying method is not particularly limited as long as the desired moisture content can be obtained. However, it is preferable that the drying method be performed efficiently by using means such as heating, air blowing, decompression, and stirring alone or in combination. The drying temperature is preferably 0 to 200 ° C, more preferably 40 to 180 ° C, and particularly preferably 50 to 160 ° C. At this time, drying at a temperature lower than the glass transition point (Tg) of the cellulose ester is preferable, and drying at a temperature lower by 10 ° C. or more than Tg is more preferable. The moisture content of the cellulose ester of the present invention obtained by drying is preferably 2% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

  When cellulose ester is used as a raw material for film production, it is preferably in the form of particles or powder. The cellulose ester after drying may be pulverized or sieved to make the particle size uniform and improve the handleability. When the cellulose ester is in the form of particles, 90% by mass or more of the particles used preferably have a particle size of 0.5 to 5 mm. Moreover, it is preferable that 50 mass% or more of the particle | grains to be used have a particle size of 1-4 mm. The cellulose ester particles preferably have a shape as close to a sphere as possible.

  The polymerization degree of the cellulose ester preferably used in the present invention is an average polymerization degree of 150 to 700, preferably 180 to 550, more preferably 180 to 400, and particularly preferably an average polymerization degree of 200 to 350. The average degree of polymerization is determined by Uda et al.'S intrinsic viscosity method (Kazuo Uda, Hideo Saito, Journal of Textile Society, Vol. 18, No. 1, pages 105-120, 1962), molecular weight distribution measurement by gel permeation chromatography (GPC), etc. It can be measured by this method. Further details are described in JP-A-9-95538. These cellulose esters may use only 1 type and may mix 2 or more types. Such adjustment of the degree of polymerization can also be achieved by removing low molecular weight components. When the low molecular component is removed, the average molecular weight (degree of polymerization) increases, but the viscosity becomes lower than that of a normal cellulose ester, which is useful. The removal of low molecular components can be carried out by washing the cellulose ester with a suitable organic solvent. Moreover, what mixed suitably polymer components other than a cellulose ester may be used. The polymer component to be mixed is preferably one having excellent compatibility with the cellulose ester, and the transmittance when formed into a film is preferably 80% or more, more preferably 90% or more, and further preferably 92% or more.

The cellulose ester used in the present invention preferably has a weight average molecular weight Mw / number average molecular weight Mn ratio of 1.5 to 5.5, particularly preferably 2.0 to 5.0, more preferably. The cellulose ester is preferably 2.5 to 5.0, more preferably 3.0 to 5.0. These cellulose esters may use only 1 type and may mix 2 or more types. Moreover, what mixed suitably polymer components other than a cellulose ester may be used. The polymer component to be mixed is preferably one having excellent compatibility with the cellulose ester, and the transmittance when formed into a film is preferably 80% or more, more preferably 90% or more, and further preferably 92% or more. The cellulose ester is preferably pelletized, and the preferred pellet size is 1 mm ^{3 to} 10 cm ³ , more preferably 5 mm ³ to 5 cm ³ , and even more preferably 10 mm ^{3 to 3} cm ³ . Then, it dries on the above-mentioned conditions. It is desirable to store the obtained cellulose ester in a low-temperature dark place so that the storage is less affected by the environment. Furthermore, it is more preferable to store in a moisture-proof bag made of a prevention material such as aluminum, a SUS drum, or a container for storage.

  In addition, the synthesis of cellulose esters having a high degree of substitution at the 6-position is described in JP-A Nos. 11-5851, 2002-212338, 2002-338601, and the like. Other synthetic methods for cellulose esters include the presence of a base (sodium hydroxide, potassium hydroxide, barium hydroxide, sodium carbonate, pyridine, triethylamine, tert-butoxy potassium, sodium methoxide, sodium ethoxide, etc.) A method of reacting with a carboxylic acid anhydride or a carboxylic acid halide, or a method using a mixed acid anhydride (such as a mixed anhydride of carboxylic acid / trifluoroacetic acid or a mixed anhydride of carboxylic acid / methanesulfonic acid) as an acylating agent may be used. In particular, the latter method is effective when introducing an acyl group having a large number of carbon atoms or an acyl group that is difficult to be subjected to liquid phase acylation using a carboxylic acid anhydride-acetic acid-sulfuric acid catalyst.

<Fluorosurfactant>
Next, the fluorosurfactant represented by any one of the general formulas (2A), (2B), (2C) and (2D) of the present invention will be described.

General formula (2A)

In the formula, R ^A1 and R ^A2 each represent a substituted or unsubstituted alkyl group, and at least one of R ^A1 and R ^A2 represents an alkyl group substituted with a fluorine atom. R ^A3 , R ^A4 and R ^A5 each independently represent a hydrogen atom or a substituent, L ^A1 , L ^A2 and L ^A3 each independently represent a single bond or a divalent linking group, and X ⁺ represents a cationic substituent. Represents a group. Y ⁻ represents a counter anion, but Y ⁻ may not be present when the charge is 0 in the molecule. m ^A is 0 or 1.

In the general formula (2A), R ^A1 and R ^A2 each represent a substituted or unsubstituted alkyl group. The alkyl group has 1 or more carbon atoms and may be linear, branched or cyclic. Examples of the substituent include a halogen atom, an alkenyl group, an aryl group, an alkoxyl group, a halogen atom other than fluorine, a carboxylic acid ester group, a carbonamido group, a carbamoyl group, an oxycarbonyl group, and a phosphoric acid ester group. However, at least one of R ^A1 and R ^A2 represents an alkyl group substituted with a fluorine atom (hereinafter, the alkyl group substituted with a fluorine atom is referred to as “Rf”).

  Rf is an alkyl group substituted with at least one fluorine atom having 1 or more carbon atoms. Rf only needs to be substituted with at least one fluorine atom, and may have any of linear, branched and cyclic structures. Further, it may be further substituted with a substituent other than a fluorine atom, or may be substituted only with a fluorine atom. Examples of the substituent other than the fluorine atom of Rf include an alkenyl group, an aryl group, an alkoxyl group, a halogen atom other than fluorine, a carboxylic acid ester group, a carbonamido group, a carbamoyl group, an oxycarbonyl group, and a phosphoric acid ester group.

Rf is preferably a fluorine-substituted alkyl group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, and still more preferably 4 to 10 carbon atoms. As a preferable example of Rf,
_{- (CH 2) 2 - (} CF 2) 4 F,
_{- (CH 2) 2 - (} CF 2) 6 F,
_{- (CH 2) 2 - (} CF 2) 8 F,
_{- (CH 2) - (CF} 2) 4 H,
_{- (CH 2) - (CF} 2) 6 H,
_{- (CH 2) - (CF} 2) 8 H,
_{- (CH 2) 3 - (} CF 2) 4 F,
_{- (CH 2) 6 - (} CF 2) 4 F,
-CH (CF ₃₎ CF _3,
Etc.

Rf is more preferably an alkyl group having 4 to 10 carbon atoms, the terminal of which is substituted with a trifluoromethyl group, and particularly preferably 3 to 3 carbon atoms represented by — (CH ₂ ) α- (CF ₂ ) βF. 10 represents an alkyl group (α represents an integer of 1 to 6; β represents an integer of 3 to 8). In particular,
_{-CH 2 - (CF 2) 2} F,
_{- (CH 2) 6 - (} CF 2) 4 F,
_{- (CH 2) 3 - (} CF 2) 4 F,
_{-CH 2 - (CF 2) 3} F,
_{- (CH 2) 2 - (} CF 2) 4 F,
_{- (CH 2) 3 - (} CF 2) 4 F,
_{- (CH 2) 6 - (} CF 2) 4 F,
_{- (CH 2) 2 - (} CF 2) 6 F,
_{- (CH 2) 3 - (} CF 2) 6 F,
_{- (CH 2) 2 - (} CF 2) 6 F,
Etc. Among these, especially
_{- (CH 2) 2 - (} CF 2) 4 F and _{- (CH 2) 2 - (} CF 2) 6 F is most preferred.

In the general formula (2A), both R ^A1 and R ^A2 preferably represent Rf.
When R ^A1 and R ^A2 each represents an alkyl group other than Rf, that is, an alkyl group not substituted with a fluorine atom, the alkyl group is preferably a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms, A substituted or unsubstituted alkyl group having 6 to 24 carbon atoms is more preferable. Preferred examples of the unsubstituted alkyl group having 6 to 24 carbon atoms include n-hexyl group, n-heptyl group, n-octyl group, tert-octyl group, 2-ethylhexyl group, n-nonyl group, 1,1, 3-trimethylhexyl group, n-decyl group, n-dodecyl group, cetyl group, hexadecyl group, 2-hexyldecyl group, octadecyl group, eicosyl group, 2-octyldodecyl group, docosyl group, tetracosyl group, 2-decyltetra A decyl group, a tricosyl group, a cyclohexyl group, a cycloheptyl group, etc. are mentioned. Preferred examples of the alkyl group having 6 to 24 carbon atoms having a substituent include 2-hexenyl group, oleyl group, linoleyl group, linolenyl group, benzyl group, β-phenethyl group, 2-methoxyethyl group, 4-phenylbutyl group, 4-acetoxyethyl group, 6-phenoxyhexyl group, 12-phenyldodecyl group, 18-phenyloctadecyl group, 12- (p-chlorophenyl) dodecyl group, 2- (diphenyl phosphate) ethyl group, etc. Can be mentioned.

The alkyl group other than Rf represented by R ^A1 and R ^A2 is more preferably a substituted or unsubstituted alkyl group having 6 to 18 carbon atoms. Preferred examples of the unsubstituted alkyl group having 6 to 18 carbon atoms include n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, 1,1,3- Examples include trimethylhexyl group, n-decyl group, n-dodecyl group, cetyl group, hexadecyl group, 2-hexyldecyl group, octadecyl group, 4-tert-butylcyclohexyl group and the like. Preferable examples of the substituted alkyl group having 6 to 18 carbon atoms having a substituent include phenethyl group, 6-phenoxyhexyl group, 12-phenyldodecyl group, oleyl group, linoleyl group, and linolenyl group. .

The alkyl group other than Rf represented by R ^A1 and R ^A2 is particularly preferably an n-hexyl group, a cyclohexyl group, an n-heptyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group, 1,1,3-trimethylhexyl group, n-decyl group, n-dodecyl group, cetyl group, hexadecyl group, 2-hexyldecyl group, octadecyl group, oleyl group, linoleyl group, linolenyl group, most preferably carbon It is a linear, cyclic or branched unsubstituted alkyl group of formula 8-16.

In the general formula (2A), R ^A3 , R ^A4 and R ^A5 each independently represent a hydrogen atom or a substituent. Substituent T described later can be applied as the substituent. R ^A3 , R ^A4 and R ^A5 preferably represent an alkyl group or a hydrogen atom, more preferably represent an alkyl group having 1 to 12 carbon atoms or a hydrogen atom, and more preferably represent a methyl group or a hydrogen atom. And particularly preferably represents a hydrogen atom.

In the general formula (2A), L ^A2 and L ^A3 each independently represent a single bond or a divalent linking group. There is no particular limitation as long as it is a single bond or a divalent linking group, but preferably an arylene group, —O—, —S— or —NR ^A100 — (R ^A100 represents a hydrogen atom or a substituent. R ^A100 is the same as the substituent T described later, preferably an alkyl group, the aforementioned Rf or hydrogen atom, more preferably a hydrogen atom), or a group obtained by combining them alone. Preferred is —O—, —S— or —NR ^A100 —. L ^A2 and L ^A3 are more preferably —O— or —NR ^A100 —, still more preferably —O— or —NH—, and particularly preferably —O—.

In the general formula (2A), L ^A1 represents a divalent linking group. The divalent linking group is not particularly limited, but is preferably an alkylene group, an arylene group, -C (= O)-, -O-, -S-, -S (= O)-, -S (= O) ₂ — or —NR ^A100 — (R ^A100 represents a hydrogen atom or a substituent, and the substituent is the same as the substituent T described later. R ^A100 is preferably an alkyl group or a hydrogen atom, and more preferably. Is a hydrogen atom), or a group obtained by combining them, more preferably an alkylene group having 1 to 12 carbon atoms, an arylene group having 6 to 12 carbon atoms, -C (= O)-, -O. —, —S—, —S (═O) —, —S (═O) ₂ — or —NR ^A100 — is a group obtained alone or in combination. More preferably, Z is an alkylene group having 1 to 8 carbon atoms, —C (═O) —, —O—, —S—, —S (═O) —, —S (═O) ₂ — or —NR. ^A100 − is a group obtained alone or in combination thereof, for example,

- (CH _{2) 2} S-,
- (CH _{2) 2} NH-,
- (CH _{2) 3} NH-,
_{- (CH 2) 2 C (} = O) NH-,
_{- (CH 2) 2 SCH 2} -,
_{- (CH 2) 2 NHCH 2} -,
_{- (CH 2) 3 NHCH 2} -,
Etc.

In the general formula (2A), X ⁺ represents a cationic substituent, and X ⁺ is preferably an organic cationic substituent, and more preferably a nitrogen or phosphorus cationic group. More preferred is a pyridinium cation or an ammonium cation, and more preferred is a trialkylammonium cation represented by the following general formula (3).

General formula (3)

In the general formula (3), R ^A13 , R ^A14 and R ^A15 each independently represent a substituted or unsubstituted alkyl group. As the substituent, those exemplified as the substituent T described later can be applied. R ^A13 , R ^A14 and R ^A15 may combine with each other to form a ring, if possible. R ^A13 , R ^A14 and R ^A15 are preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and still more preferably a methyl group, an ethyl group or a methyl carboxyl group. And particularly preferably a methyl group.

In the general formula (3), Y ⁻ represents a counter anion and may be an inorganic anion or an organic anion. Further, when the charge becomes 0 in the molecule, Y ⁻ may not be present. Preferred examples of the inorganic anion include iodo ion, bromine ion and chlorine ion, and preferred examples of the organic anion include p-toluenesulfonate ion and benzenesulfonate ion. Y ^- is more preferably iodo ion, p-toluenesulfonic acid ion or benzenesulfonic acid ion, and still more preferably p-toluenesulfonic acid.

In the general formula (2A), m ^A represents 0 or 1, preferably 0.
Among the compounds represented by the general formula (2A), a compound represented by the following general formula (2A-1) is preferable.

General formula (2A-1)

In General Formula (2A-1), R ^A11 and R ^A12 each represent a substituted or unsubstituted alkyl group, and at least one of R ^A11 and R ^A12 represents an alkyl group substituted with a fluorine atom, and R ^A11 And the total number of carbon atoms of R ^A12 is 19 or less. L ^A2 and L ^A3 each independently represent —O—, —S—, or —NR ¹⁰⁰ —, R ¹⁰⁰ represents a hydrogen atom or a substituent, and L ^A1 represents a single bond or a divalent linking group. L ^A1 and Y ⁻ have the same meanings as those in the general formula (2A), and preferred ranges thereof are also the same. R ^A13 , R ^A14 and R ^A15 have the same ^{meanings as} those in the general formula (3), and preferred ranges thereof are also the same.

In the general formula (2A-1), L ^A2 and L ^A3 are each —O—, —S—, or —NR ¹⁰⁰ — (R ¹⁰⁰ represents a hydrogen atom or a substituent, and the substituent is a substituent described later. Those listed as T can be applied, and R ¹⁰⁰ is preferably an alkyl group, the aforementioned Rf, or a hydrogen atom, and more preferably a hydrogen atom. L ^A2 and L ^A3 are more preferably —O— or —NH—, and still more preferably —O—.

In the general formula (2A-1), R ^A11 and R ^A12 have the same ^{meanings as} R ^A1 and R ^A2 in the general formula (2A), respectively, and preferred ranges thereof are also the same. However, the total number of carbon atoms of R ^A11 and R ^A12 is 19 or less.
Among the compounds represented by the general formula (2), a compound represented by the following general formula (2A-2) is more preferable.

General formula (2A-2)

In the general formula (2A-2), R ^A13 , R ^A14 , R ^A15 , L ^A1 and Y ⁻ have the same ^{meanings as those in} the general formula (2A) and the general formula (3), respectively, and preferred ranges thereof are also the same. It is. A and B each independently represent a fluorine atom or a hydrogen atom. A and B both preferably represent a fluorine atom or a hydrogen atom, and preferably both represent a fluorine atom. In the general formula (2A-2), n ^A1 represents an integer of 1 to 6, and n ^A2 represents an integer of 3 to 8. Among the compounds represented by the general formula (2A), a compound represented by the following general formula (2A-3) is more preferable.

General formula (2A-3)

In the general formula (2A-3), n ^A1 represents any integer of 1 to 6, n ^A2 represents any integer of 3 to 8, but 2 (n ^A1 + n ^A2 ) is 19 or less. . R ^A13 , R ^A14 , R ^A15 , L ^A1 and Y ⁻ have the same ^{meanings as those in} the general formula (2A) and the general formula (3), respectively, and preferred ranges thereof are also the same.
n ^A1 represents an integer of 1 to 6, preferably an integer of 1 to 3, more preferably 2 or 3, and most preferably 2. n ^A2 represents an integer of 3 to 8, more preferably 3 to 6, and still more preferably 4 to 6. As a preferable combination of n ^A1 and n ^A2 , n ^A1 is preferably 2 or 3, and n ^A2 is preferably 4 or 6.

  Specific examples of the compound represented by the general formula (2A) are shown below, but the present invention is not limited to the following specific examples. Unless otherwise specified, the alkyl group and the perfluroalkyl group mean a straight chain structure in the structure notation of the exemplified compounds below. Of the abbreviations in the notation, 2EH means 2-ethylhexyl, and 2BO means 2-Butyllocyl.

  Next, the compound represented by the following general formula (2B) will be described in detail.

General formula (2B)

In the general formula (2B), R ^B3 , R ^B4 and R ^B5 each independently represent a hydrogen atom or a substituent. A and B each independently represent a fluorine atom or a hydrogen atom. n ^B3 and n ^B4 each independently represents an integer of 4 to 8. L ^B1 and L ^B2 each independently represent a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkyleneoxy group, or a divalent linking group formed by combining these. m ^B represents 0 or 1. M represents a cation.

In the general formula (2B), R ^B3 , R ^B4 and R ^B5 each independently represent a hydrogen atom or a substituent. Substituent T described later can be applied as the substituent.
R ^B3 , R ^B4 and R ^B5 are preferably an alkyl group or a hydrogen atom, more preferably an alkyl group having 1 to 12 carbon atoms or a hydrogen atom, still more preferably a methyl group or a hydrogen atom, Preferably it is a hydrogen atom. In the general formula (2B), A and B each independently represent a fluorine atom or a hydrogen atom. A and B are preferably both fluorine atoms or both hydrogen atoms, more preferably both fluorine atoms. In the general formula (2B), n ^B3 and n ^B4 each independently represents an integer of 4 to 8.

Preferably as n ^B3 and n ^B4 in integer of 4-6, and a n ^B3 = n ^B4, more preferably an integer of 4 or 6, and an n ^B3 = n ^B4, more preferably n ^B3 = n ^B4 = 4. In the general formula (2B), m ^B represents 0 or 1, both of which are likewise preferred.
In the general formula (2B), L ^B1 and L ^B2 each independently represent a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkyleneoxy group, or a divalent group formed by combining these. As the substituent, a substituent of the substituent T described later can be applied. L ^B1 and L ^B2 each preferably have 4 or less carbon atoms, and are preferably unsubstituted alkylene.

  M represents a cation and has the same meaning as M in the general formula (1). M is preferably lithium ion, sodium ion, potassium ion or ammonium ion, and more preferably lithium ion, sodium ion or potassium ion. More preferred is sodium ion. Among the compounds represented by the general formula (2B), compounds represented by the following general formula (2B-1) are preferable.

前記一般式（２Ｂ−１）中、Ｒ^B3、Ｒ^B4、Ｒ^B5、ｎ^B3、ｎ^B4、ｍ^B、Ａ、ＢおよびＭは、上記一般式（２Ｂ）におけるそれらと同義であり、また好ましい範囲も同様である。ｎ^B1およびｎ^B2はそれぞれ独立に１〜６のいずれかの整数を表す。前記一般式（２Ｂ−１）中、ｎ^B1およびｎ^B2はそれぞれ独立に１〜６のいずれかの整数を表す。ｎ^B1およびｎ^B2は１〜６の整数で、かつｎ^B1＝ｎ^B2であるのが好ましく、２または３で、かつｎ^B1＝ｎ^B2であるのがより好ましく、ｎ^B1＝ｎ^B2＝２であるのが更に好ましい。
上記一般式（２Ｂ）で表される化合物の中でも、下記一般式（２Ｂ−２）で表される化合物がより好ましい。 General formula (2B-1)

In the general formula (2B-1), R ^B3 , R ^B4 , R ^B5 , n ^B3 , n ^B4 , m ^B , A, B and M have the same meaning as those in the general formula (2B), and are preferable. The range is the same. n ^B1 and n ^B2 each independently represent an integer of 1 to 6. In the general formula (2B-1), n ^B1 and n ^B2 each independently represents an integer of 1 to 6. n ^B1 and n ^B2 in integer of 1 to 6, and is preferably an n ^B1 = n ^B2, 2 or 3, and more preferably from ^{n B1 = n B2, n B1} = n B2 = 2 More preferably.
Among the compounds represented by the general formula (2B), a compound represented by the following general formula (2B-2) is more preferable.

前記一般式（２Ｂ−２）中、ｎ^B3、ｎ^B4、ｍ^BおよびＭは上記一般式（２Ｂ）におけるそれらと同義であり、また好ましい範囲も同様である。前記一般式（２Ｂ−２）中、ｎ^B1およびｎ^B2は一般式（２Ｂ−１）におけるそれらと同義であり、また好ましい範囲も同様である。
上記一般式（２Ｂ）で表される化合物としては、より好ましくは下記一般式（２Ｂ−３）で表される化合物である。 General formula (2B-2)

In the general formula (2B-2), n ^B3 , n ^B4 , m ^B and M have the same meanings as those in the general formula (2B), and preferred ranges are also the same. In the general formula (2B-2), n ^B1 and n ^B2 have the same ^{meanings as those} in the general formula (2B-1), and preferred ranges are also the same.
The compound represented by the general formula (2B) is more preferably a compound represented by the following general formula (2B-3).

前記一般式（２Ｂ−３）中、ｎ^B5は２または３を表し、ｎ^B6は４〜６のいずれかの整数を表す。ｍ^Bは０または１を表し、どちらも同様に好ましい。Ｍは上記一般式（２Ｂ）におけるＭと同義であり、また、好ましい範囲も同様である。 以下に、上記一般式（２Ｂ）にで表される化合物の具体例を示すが、本発明は以下の具体例によってなんら限定されるものではない。 General formula (2B-3)

In the general formula (2B-3), n ^B5 represents 2 or 3, and n ^B6 represents any integer of 4 to 6. m ^B represents 0 or 1, both of which are likewise preferred. M has the same meaning as M in the general formula (2B), and the preferred range is also the same. Specific examples of the compound represented by the general formula (2B) are shown below, but the present invention is not limited to the following specific examples.

次に下記一般式（２Ｃ）で表される化合物について詳細に説明する。

Next, the compound represented by the following general formula (2C) will be described in detail.

前記一般式（２Ｃ）中、Ｒ^C1は置換もしくは無置換のアルキル基を表し、Ｒ^CFはパーフルオロアルキレン基を表す。Ａは水素原子またはフッ素原子を表し、Ｌ^C1は置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンオキシ基またはこれらを組み合わせてできる２価の連結基を表す。Ｙ^C1およびＹ^C2は一方が水素原子を、もう一方が−Ｌ^C2−ＳＯ₃Ｍを表し、Ｌ^C2は単結合または炭素数１〜１０の、置換もしくは無置換のアルキレン基を表し、Ｍはカチオンを表す。 General formula (2C)

In the general formula (2C), R ^C1 represents a substituted or unsubstituted alkyl group, and R ^CF represents a perfluoroalkylene group. A represents a hydrogen atom or a fluorine atom, and L ^C1 represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkyleneoxy group, or a divalent linking group formed by combining these. One of Y ^C1 and Y ^C2 represents a hydrogen atom, the other represents -L ^C2 -SO ₃ M, L ^C2 represents a single bond or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, M is Represents a cation.

In the general formula (2C), R ^C1 represents a substituted or unsubstituted alkyl group. The substituted or unsubstituted alkyl group represented by R ^C1 may be linear, branched, or have a cyclic structure. Substituent T described later can be applied as the substituent. Preferred examples of the substituent include alkenyl groups, aryl groups, alkoxy groups, halogen atoms (preferably Cl), carboxylic acid ester groups, carbonamido groups, carbamoyl groups, oxycarbonyl groups, and phosphoric acid ester groups. R ^C1 is preferably an unsubstituted alkyl group, R ^C1 is more preferably an unsubstituted alkyl group having 2 to 24 carbon atoms, still more preferably an unsubstituted alkyl group having 4 to 20 carbon atoms, and particularly preferably Is an unsubstituted alkyl group having 6 to 24 carbon atoms.

R ^CF represents a perfluoroalkylene group. Here, the perfluoroalkylene group refers to a group in which all hydrogen atoms of the alkylene group are fluorine-substituted. The perfluoroalkylene group may be linear or branched, and may have a cyclic structure. R ^CF preferably has 1 to 10 carbon atoms, and more preferably 1 to 8 carbon atoms.
A represents a hydrogen atom or a fluorine atom, and is preferably a fluorine atom.
L ^C1 represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkyleneoxy group, or a divalent group formed by combining these. The substituent is the same as the preferred range of the substituent mentioned for R ^C1 . L ^C1 preferably has 4 or less carbon atoms, and is preferably unsubstituted alkylene.

One of Y ^C1 and Y ^C2 represents a hydrogen atom, the other represents -L ^C2 -SO ₃ M, and M represents a cation. Here, preferred examples of the cation represented by M include alkali metal ions (lithium ions, sodium ions, potassium ions, etc.), alkaline earth metal ions (barium ions, calcium ions, etc.), ammonium ions, and the like. . Of these, more preferred are lithium ion, sodium ion, potassium ion or ammonium ion, still more preferred are lithium ion, sodium ion or potassium ion, and the total number of carbon atoms and substituents of the compound of the general formula (2C). The alkyl group can be appropriately selected depending on the degree of branching of the alkyl group.

When the total number of carbon atoms of R ^C1 , R ^CF and L ^C1 is 16 or more, lithium ions are excellent in terms of compatibility between solubility (particularly against water) and antistatic ability or coating uniformity. . L ^C2 represents a single bond or a substituted or unsubstituted alkylene group. The substituent is the same as the preferred range of the substituent mentioned for R ^C1 .
L ^C2 is preferably a single bond or an alkylene group having 2 or less carbon atoms, more preferably a single bond or an unsubstituted alkylene group, and still more preferably a single bond or a methylene group. L ^C2 is particularly preferably a single bond.
Among the compounds represented by the general formula (2C), a compound represented by the following general formula (2C-1) is preferable.

General formula (2C-1)

In the general formula (2C-1), R ^C11 represents a substituted or unsubstituted alkyl group having a total carbon number of 6 or more. R ^CF1 represents a perfluoroalkyl group having 6 or less carbon atoms. One of Y ^C11 and Y ^C12 represents a hydrogen atom, the other represents SO ₃ M ^C , and M ^C represents a cation. n ^C1 represents an integer of 1 or more.

In the general formula (2C-1), R ^C11 represents a substituted or unsubstituted alkyl group having 6 or more carbon atoms in total. However, R ^C11 does not become an alkyl group substituted with a fluorine atom. The substituted or unsubstituted alkyl group represented by R ^C11 may be linear, branched, or have a cyclic structure. Examples of the substituent include alkenyl groups, aryl groups, alkoxy groups, halogen atoms other than fluorine, carboxylic acid ester groups, carbonamido groups, carbamoyl groups, oxycarbonyl groups, and phosphoric acid ester groups.

The substituted or unsubstituted alkyl group represented by R ^C11 preferably has 6 to 24 carbon atoms in total. Preferred examples of the unsubstituted alkyl group having 6 to 24 carbon atoms include n-hexyl group, n-heptyl group, n-octyl group, tert-octyl group, 2-ethylhexyl group, n-nonyl group, 1,1, 3-trimethylhexyl group, n-decyl group, n-dodecyl group, cetyl group, hexadecyl group, 2-hexyldecyl group, octadecyl group, eicosyl group, 2-octyldodecyl group, docosyl group, tetracosyl group, 2-decyltetra A decyl group, a tricosyl group, a cyclohexyl group, a cycloheptyl group, etc. are mentioned. In addition, preferred examples of the substituted alkyl group having 6 to 24 carbon atoms including the carbon atoms of the substituent include 2-hexenyl group, oleyl group, linoleyl group, linolenyl group, benzyl group, β-phenethyl group, 2- Methoxyethyl group, 4-phenylbutyl group, 4-acetoxyethyl group, 6-phenoxyhexyl group, 12-phenyldodecyl group, 18-phenyloctadecyl group, 12- (p-chlorophenyl) dodecyl group, 2- (diphenyl phosphate) An ethyl group etc. can be mentioned.

The substituted or unsubstituted alkyl group represented by R ^C11 preferably has a total carbon number of 6 to 18. Preferred examples of the unsubstituted alkyl group having 6 to 18 carbon atoms include n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, 1,1,3- Examples include trimethylhexyl group, n-decyl group, n-dodecyl group, cetyl group, hexadecyl group, 2-hexyldecyl group, octadecyl group, 4-tert-butylcyclohexyl group and the like. In addition, preferable examples of the substituted alkyl group having 6 to 18 carbon atoms in total including the carbon number of the substituent include phenethyl group, 6-phenoxyhexyl group, 12-phenyldodecyl group, oleyl group, linoleyl group, linolenyl group, and the like. Is mentioned. Among them, as R ^C11 , n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, 1,1,3-trimethylhexyl group, n-decyl group, n-dodecyl group, cetyl group, hexadecyl group, 2-hexyldecyl group, octadecyl group, oleyl group, linoleyl group, and linolenyl group are more preferable, linear, cyclic or branched unsubstituted having 8 to 16 carbon atoms. Particularly preferred is an alkyl group.

In the general formula (2C-1), R ^CF1 represents a perfluoroalkyl group having 6 or less carbon atoms. Here, the perfluoroalkyl group refers to a group in which all hydrogen atoms of the alkyl group are substituted with fluorine. The alkyl group in the perfluoroalkyl group may be linear or branched, and may have a cyclic structure. Examples of the perfluoroalkyl group represented by R ^CF1 include trifluoromethyl group, pentafluoroethyl group, heptafluoro-n-propyl group, heptafluoroisopropyl group, nonafluoro-n-butyl group, undecafluoro-n. -Pentyl group, tridecafluoro-n-hexyl group, undecafluorocyclohexyl group and the like. Of these, a perfluoroalkyl group having 2 to 4 carbon atoms (for example, a pentafluoroethyl group, a heptafluoro-n-propyl group, a heptafluoroisopropyl group, a nonafluoro-n-butyl group, etc.) is preferable, and heptafluoro-n-propyl. The group, nonafluoro-n-butyl group is particularly preferred.

In the general formula (2C-1), n ^C1 represents an integer of 1 or more. Preferably, it is an integer of 1 to 4, and particularly preferably 1 or 2.
Further, as a combination of n ^C1 and R ^CF1 , when n ^C1 = 1, R ^CF1 is a heptafluoro-n-propyl group or a nonafluoro-n-butyl group; when n ^C1 = 2, R ^CF1 is nonafluoro- More preferably, it is an n-butyl group.

In the general formula (2C-1), Y ^C11 and Y ^C12 is a hydrogen atom while the other represents SO ₃ M ^C, M ^C represents a cation. Examples of the cation represented by M ^C, for example, an alkali metal ion (lithium ion, sodium ion, potassium ion), alkaline earth metal ions (barium ion, calcium ion, etc.), an ammonium ion and the like are preferably exemplified The Of these, lithium ion, sodium ion, potassium ion or ammonium ion is particularly preferable, and sodium ion is most preferable.
Specific examples of the compound represented by the general formula (2C) are shown below, but the present invention is not limited to the following specific examples.

Next, the general formula (2D) will be described in detail.
General formula (2D)
[Rf ^D- (L ^D ) _nD ] _mD -W
In the formula, Rf ^D represents a perfluoroalkyl group, L ^D represents an alkylene group, and W has an anionic group, a cationic group, a betaine group, or a nonionic polar group necessary for imparting surface activity. Represents a group. n ^D represents an integer of 0 or 1, m ^D represents an integer of 1-3.

Rf ^D represents a C 3-20 perfluoroalkyl group, and specific examples thereof include C ₃ F ₇ -group, C ₄ F ₉ -group, C ₆ F ₁₃ -group, C ₈ H ₁₇ -group, C _{8 And 12} F ₂₅ -group, C ₁₆ F ₃₃ -group, and the like.

The L ^D group represents an alkylene group. The alkylene group has 1 or more carbon atoms, preferably 2 or more, and preferably 20 or less. Specifically, methylene group, ethylene group, 1,2-propylene group, 1,3-propylene group, 1,2-butylene group, 1,4-butylene group, 1,6-hexylene group, 1,2-octylene. Groups and the like.

In the present invention, a mixture of a plurality of compounds in which Rf ^D is a perfluoroalkyl group having a chain length different from each other may be used, or only a compound having a single perfluoroalkyl group may be used. Also, a mixture of a plurality of compounds having the same Rf ^{D and} different L ^D may be used. In the present invention, when using a mixture of a plurality of compounds in which Rf ^D is a perfluoroalkyl group having a chain length different from each other, the average chain length of the perfluoroalkyl group is preferably 4 to 10 carbon atoms. 4 to 9 is particularly preferable.

n ^D represents an integer of 0 or 1, and is preferably 1. m ^D represents an integer of 1 to 3, and when m ^D is 2 or 3, [Rf ^D- (L ^D ) n ^D ] may be the same as or different from each other. When W is not a phosphate ester group, m ^D = 1 is preferable. When W represents a phosphate ester group, any of m ^D = 1 to 3 may be used, and when m ^D = 1 to 3 is a mixture, The average value is preferably 0.5-2.

  W represents a group having a cationic group, an anionic group, a betaine group, or a polar nonionic group necessary for imparting surface activity. As long as these groups are included, the connection method with Rc is not limited. Examples of anionic groups necessary for imparting surface activity include sulfonic acid groups and their ammonium or metal salts, carboxylic acid groups and their ammonium or metal salts, phosphonic acid groups and their ammonium or metal salts, sulfate ester groups and Examples thereof include ammonium or metal salts thereof, phosphate ester groups and ammonium or metal salts thereof.

Examples of cationic groups necessary for imparting surface activity include quaternary alkylammonium groups such as trimethylammoniumethyl group and trimethylammoniumpropyl group; aromatic ammonium such as dimethylphenylammoniumalkyl group and N-methylpyridinium group Groups. An appropriate counter ion exists in these groups, and examples thereof include a halogen atom, a benzenesulfonate anion, a toluenesulfonate anion, and the like, and a toluenesulfonate anion is preferable. Examples of the betaine group necessary for imparting surface activity include a group having a betaine structure such as —N ⁺ (CH ₃ ) ₂ CH ₂ COO ⁻ and —N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ COO ^−. Is mentioned. Examples of nonionic groups necessary for imparting surface activity include polyoxyalkylene groups and polyhydric alcohol groups, with polyoxyalkylene groups such as polyethylene glycol and polypropylene glycol being preferred. However, the terminal of these groups may be a group other than a hydrogen atom, for example, an alkyl group.

In the general formula (2D), Rf ^D is preferably a perfluoroalkyl group having 4 to 16 carbon atoms, and more preferably a perfluoroalkyl group having 6 to 16 carbon atoms. L ^D preferably represents an alkylene group having 2 to 16 carbon atoms, more preferably represents an alkylene group having 2 to 8 carbon atoms, and particularly preferably represents an ethylene group. n ^D is preferably 1. L ^D and the group necessary for imparting surface activity may be bonded in any manner, for example, they can be bonded by an alkylene chain, arylene, etc., and these groups may have a substituent. . These groups may contain an oxy group, a thio group, a sulfonyl group, a sulfoxide group, a sulfonamide group, an amide group, an amino group or the like in the main chain or side chain.

  Specific examples of the compound represented by the general formula (2D) are shown below, but the present invention is not limited to the following specific examples.

  The compound represented by the above general formula (2D) can be produced by a usual synthesis method, and those widely marketed as so-called telomer type perfluoroalkyl group-containing surfactants can be used. . Examples include ZONYL FSP, FSE, FSJ, NF, TBS, FS-62, FSA, FSK (more ionic), ZONYL 9075, FSO, FSN, FSN-100, FS-300, manufactured by DUPONT Corporation. FS-310 (more non-ionic), S-111, S-112, S-113, S-121, S-131, S-132 (more ionic), S-141, S manufactured by Asahi Glass Co., Ltd. -145 (more nonionic), Unidyne DS-101, DS-102, DS-202, DS-301 (more ionic), DS-401, DS-403 (more nonionic) manufactured by Daikin Industries, Ltd. And the like.

  Of the various compounds described above, ionic surfactants are used in various different salt forms by means of ion exchange or neutralization, etc., depending on the purpose of use, various properties required, etc. It can be used in the presence of two or more counter ions.

  Hereinafter, examples of the substituent which the substitutable group in the above general formula may have and the substituent T will be described. Examples of the substituent T include an alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms. Examples thereof include a methyl group, an ethyl group, and isopropyl. Group, tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group and the like, alkenyl group (preferably having 2 to 20 carbon atoms, more preferably). Is an alkenyl group having 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a 2-butenyl group, and a 3-pentenyl group, and an alkynyl group (preferably a carbon atom). An alkynyl group having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, such as a propargyl group, 3 A pentynyl group), an aryl group (preferably an aryl group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 12 carbon atoms, such as a phenyl group and p-methyl group). A phenyl group, a naphthyl group, etc.), a substituted or unsubstituted amino group (preferably a carbon number of 0-20, more preferably a carbon number of 0-10, particularly preferably a carbon number of 0-6, For example, an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, a dibenzylamino group, etc.)

An alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, and a butoxy group). An aryloxy group (preferably an aryloxy group having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include a phenyloxy group and a 2-naphthyloxy group. An acyl group (preferably having a carbon number of 1-20, more preferably a carbon number of 1-16, particularly preferably a carbon number of 1-12, such as an acetyl group, a benzoyl group, a formyl group, a pivaloyl group, etc. An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 2 carbon atoms). 2 alkoxycarbonyl groups, for example, methoxycarbonyl group, ethoxycarbonyl group and the like, and aryloxycarbonyl groups (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, and particularly preferably carbon numbers). An aryloxycarbonyl group having 7 to 10 carbon atoms, such as a phenyloxycarbonyl group, an acyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 2 carbon atoms). 10 acyloxy groups such as an acetoxy group and a benzoyloxy group)

An acylamino group (preferably an acylamino group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as an acetylamino group and a benzoylamino group), alkoxycarbonyl An amino group (preferably an alkoxycarbonylamino group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as a methoxycarbonylamino group), aryloxy Carbonylamino group (preferably an aryloxycarbonylamino group having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as a phenyloxycarbonylamino group) Sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferred Or a sulfonylamino group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include a methanesulfonylamino group and a benzenesulfonylamino group, and a sulfamoyl group (preferably having a carbon number of 0 to 20). More preferably, it is a sulfamoyl group having 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, and examples thereof include a sulfamoyl group, a methylsulfamoyl group, a dimethylsulfamoyl group, and a phenylsulfamoyl group. ), A carbamoyl group (preferably a carbamoyl group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms. For example, an unsubstituted carbamoyl group, a methylcarbamoyl group, diethylcarbamoyl group Group, phenylcarbamoyl group, etc.),

An alkylthio group (preferably an alkylthio group having 1 to 20 carbon atoms, more preferably an alkylthio group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as a methylthio group and an ethylthio group), an arylthio group ( Preferably it is C6-C20, More preferably, it is C6-C16, Most preferably, it is C6-C12 arylthio group, for example, a phenylthio group etc. are mentioned, A sulfonyl group (preferably C1-C1). 20, more preferably a sulfonyl group having 1 to 16 carbon atoms, particularly preferably a sulfonyl group having 1 to 12 carbon atoms, such as a mesyl group and a tosyl group, and a sulfinyl group (preferably having a carbon number of 1 to 20, more A sulfinyl group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms is preferable. Zensulfinyl group and the like), ureido group (preferably a ureido group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, an unsubstituted ureido group , Methylureido group, phenylureido group, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, particularly preferably having 1 to 12 carbon atoms). Yes, for example, diethyl phosphoric acid amide group, phenyl phosphoric acid amide group, etc.), hydroxy group, mercapto group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, Carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having a carbon number of 1 to 0, more preferably a heterocyclic group of 1 to 12, for example, a heterocyclic group having a heteroatom such as a nitrogen atom, an oxygen atom, a sulfur atom, such as an imidazolyl group, a pyridyl group, a quinolyl group, a furyl group , Piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably A silyl group having 3 to 24 carbon atoms, and examples thereof include a trimethylsilyl group and a triphenylsilyl group). These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be bonded to each other to form a ring.

The amount of the fluorosurfactant used in the present invention is 0.01 to 5% by mass, preferably 0.02 to 3% by mass, more preferably 0.05 to 2%, based on the solid content of the cellulose ester. It is mass%, Most preferably, it is 0.05-1 mass%.
The form of the fluorosurfactant of the present invention is not particularly limited, and there is no problem whether it is fixed or liquid at room temperature (25 ° C.). The addition method is not particularly limited, and only the fluorosurfactant may be mixed in an organic solvent, and then the cellulose ester powder may be added. Moreover, you may add a fluorine-type surfactant, after melt | dissolving a cellulose ester in the organic solvent. The fluorosurfactant may be added in its liquid or solid state, or a fluorosurfactant solution prepared by dissolving a part of the organic solvent in advance is added to the organic solvent or cellulose ester solution. It may be added. In particular, when the fluorosurfactant is solid, it is dissolved in an organic solvent in advance to provide consistent productivity, and is stored in a dedicated tank and transported to a cellulose ester dissolution facility via piping as necessary. The

<Method for producing cellulose ester film>
Various additives (for example, a plasticizer, an ultraviolet inhibitor, a deterioration inhibitor, fine particles, an optical property modifier, etc.) according to the application can be added to the cellulose ester of the present invention in each preparation step. Moreover, the addition time may be added at any time in the melt (dope) production process, but may be performed by adding an additive to the final preparation process of the dope preparation process. As a plasticizer to be preferably added, phosphate ester or carboxylic acid ester is used. Examples of phosphate esters include triphenyl phosphate (TPP) and tricresyl phosphate (TCP), cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate.

  Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethyl hexyl phthalate (DEHP). Examples of citrate esters include triethyl O-acetyl citrate (OACTE) and tributyl O-acetyl citrate (OACTB), acetyl triethyl citrate, acetyl tributyl citrate.

  Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Examples of glycolic acid esters include triacetin, tributyrin, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, and butyl phthalyl butyl glycolate. Further trimethylolpropane tribenzoate, pentaerythritol tetrabenzoate, ditrimethylolpropane tetraacetate, ditrimethylolpropane tetrapropionate, pentaerythritol tetraacetate, sorbitol hexaacetate, sorbitol hexapropionate, sorbitol triacetate tripropionate, inositol pentaacetate Sorbitan tetrabutyrate is also preferably used.

  Among them, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, diethyl hexyl phthalate, triacetin, ethyl phthalyl ethyl glycolate, trimethylol propane tribenzoate, penta Erythritol tetrabenzoate, ditrimethylolpropane tetraacetate, pentaerythritol tetraacetate, sorbitol hexaacetate, sorbitol hexapropionate, sorbitol triacetate tripropionate and the like are preferable. In particular, triphenyl phosphate, diethyl phthalate, ethyl phthalyl ethyl glycolate, trimethylolpropane tribenzoate, pentaerythritol tetrabenzoate, ditrimethylolpropane tetraacetate, sorbitol hexaacetate, sorbitol hexapropionate, and sorbitol triacetate tripropionate are preferable. These plasticizers may be used alone or in combination of two or more. The addition amount of the plasticizer is preferably 5 to 30% by mass, particularly preferably 5 to 16% by mass with respect to the cellulose ester. As these plasticizers, (di) pentaerythritol esters described in JP-A No. 11-124445, glycerol esters described in JP-A No. 11-246704, diglycerol esters described in JP-A No. 2000-63560, Examples thereof include citrate esters described in JP-A No. 11-92574, substituted phenyl phosphate esters described in JP-A No. 11-90946, and the like.

  A degradation inhibitor (for example, an antioxidant, a peroxide decomposer, a radical inhibitor, a metal deactivator, an acid scavenger, an amine) or an ultraviolet ray inhibitor may be added to the cellulose ester film. As for these deterioration preventing agents and ultraviolet ray preventing agents, JP-A-60-235852, JP-A-3-199201, JP-A-51907073, JP-A-5-194789, JP-A-5-271471, JP-A-6-107854. 6-118233, 6-148430, 7-11056, 7-11055, 7-11056, 8-29619, 8-239509, JP-A-2000-204173. There are descriptions in each publication. These addition amounts are preferably 0.01 to 1% by mass, and more preferably 0.01 to 0.2% by mass of the melt (dope) to be prepared. When the addition amount is less than 0.01% by mass, the effect of the deterioration preventing agent is hardly recognized. When the addition amount exceeds 1% by mass, bleed-out (bleeding) of the deterioration preventing agent to the film surface may be observed. As a particularly preferred example of the deterioration preventing agent, butylated hydroxytoluene (BHT) can be mentioned.

  Particularly preferably, one or more ultraviolet absorbers are contained. From the viewpoint of preventing deterioration of the liquid crystal, the ultraviolet absorbent for liquid crystal is preferably excellent in the ability to absorb ultraviolet light having a wavelength of 380 nm or less, and has little absorption of visible light having a wavelength of 400 nm or more from the viewpoint of liquid crystal display properties. Examples include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like. Particularly preferred ultraviolet absorbers are benzotriazole compounds and benzophenone compounds. Among these, a benzotriazole-based compound is preferable because unnecessary coloring with respect to the cellulose ester is small.

  Preferred UV inhibitors include 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], triethylene glycol -Bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine, 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di tert-butyl-4-hydroxyphenyl) propionate, N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6 -Tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate and the like. In particular, 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate] is most preferred. Further, for example, hydrazine-based metal deactivators such as N, N′-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine and tris (2,4-di-tert A phosphorus processing stabilizer such as -butylphenyl) phosphite may be used in combination. The addition amount of these compounds is preferably 1 ppm to 3.0%, more preferably 10 ppm to 2% in terms of mass ratio with respect to the cellulose ester.

  A retardation increasing agent for controlling the optical anisotropy is optionally added. In order to adjust the retardation of the cellulose ester film, it is preferable to use an aromatic compound having at least two aromatic rings as a retardation increasing agent. An aromatic compound is used in 0.01-20 mass parts with respect to 100 mass parts of cellulose esters. The aromatic compound is preferably used in the range of 0.05 to 15 parts by mass, and more preferably in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the cellulose acylate. Two or more aromatic compounds may be used in combination. The aromatic ring of the aromatic compound includes an aromatic hetero ring in addition to the aromatic hydrocarbon ring.

  The aromatic hydrocarbon ring is particularly preferably a 6-membered ring (that is, a benzene ring). The aromatic heterocycle is generally an unsaturated heterocycle. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As the hetero atom, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable. Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring , Pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring.

  By appropriately using a retardation increasing agent, the Re retardation value and the Rth retardation value can be adjusted. In this specification, the Re retardation value and the Rth retardation value are calculated based on the following. Re (λ) and Rth (λ) respectively represent in-plane retardation and retardation in the thickness direction at wavelength λ. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH (manufactured by Oji Scientific Instruments). Rth (λ) is measured by making light of wavelength λnm incident from the direction inclined with respect to the normal direction of the film, using Re (λ) and the slow axis (determined by KOBRA 21ADH) as the tilt axis (rotation axis). KOBRA 21ADH is calculated based on the plurality of retardation values. At this time, it is necessary to input an assumed value of average refractive index and a film thickness.

  KOBRA 21ADH calculates nx, ny, and nz in addition to Rth (λ). The average refractive index of 1.48 is used for cellulose acetate, but values of polymer films for typical optical applications other than cellulose acetate include cycloolefin polymer (1.52), polycarbonate (1.59), poly Values such as methyl methacrylate (1.49) and polystyrene (1.59) can be used. As the average refractive index value of other existing polymer materials, a polymer handbook (John Wiley & Sons, Inc.) or a catalog value of a polymer film can be used. In the case of a material whose average refractive index is unknown, it can be measured using an Abbe refractometer. In this specification, λ refers to 550 ± 5 nm or 590 ± 5 nm unless otherwise specified.

Generally, the Rth of the cellulose ester film of the present invention is −200 nm to 500 nm per 100 μm, and further used at −100 nm to 400 nm. It is particularly preferable to use at −70 nm to 250 nm. Further, Re is 0 nm to 200 nm per 100 μm, and it is particularly preferable to use 0 nm to 150 nm. At this time, Re may be either a casting method or a width direction and is not particularly limited.
In addition, various additives may be added to the cellulose ester of the present invention as needed at any stage after preparation of the melt. Additives include heat stabilizers such as ultraviolet absorbers, silica, kaolin, talc, diatomaceous earth, quartz, calcium carbonate, barium sulfate, titanium oxide, inorganic particles such as alumina, and group 2 metal salts such as calcium and magnesium, Antistatic agents, flame retardants, lubricants, oils, etc.

Next, the melt film-forming process of the present invention and its conditions will be described.
In general, melt film formation is carried out through a kneading / extrusion process, a casting process, a stretching process, a relaxation process, a cooling process, a winding process, and a processing process in which cellulose ester is preheated to a predetermined temperature and mixed with additives. A cellulose ester film is obtained. In the following, the melt film-forming technique of the present invention will be described. In the present invention, in order to improve the display unevenness of the liquid crystal display device, the cellulose ester is characterized by containing a fluorosurfactant. Can be made as small as possible. The optimization of melt film forming conditions is described in detail below.

1) Preheating of cellulose ester After sufficiently drying cellulose ester in advance, it is put into a hopper of a melt extruder. As preferable drying, the water content in the cellulose ester is 0.5% by mass or less, more preferably 0.2% by mass, and particularly 0.1% by mass or less. Thereby, the hydrolysis of the cellulose ester which develops during melting can be suppressed, and the generation of foreign substances associated therewith can be suppressed. Such drying can be achieved by drying the cellulose ester preferably at 80 to 180 ° C., preferably for 0.1 to 100 hours. This treatment may be performed in an air atmosphere, in an inert gas (for example, nitrogen) atmosphere, or in a vacuum. Foreign substances generated during film formation can be reduced by the pretreatment. This is because the generation source of the foreign matter is derived from the decomposition product of cellulose ester. The heating temperature of the hopper that is preferably used in the present invention is preferably (Tg-50 ° C) to (Tg + 30 ° C), more preferably (Tg-40 ° C) to (Tg + 10 ° C), and more preferably (Tg). It is recommended to heat to −30 ° C.) to Tg. Thereby, moisture re-adsorption from the air to the cellulose ester in the hopper can be suppressed.

2) Kneading and Extruding The cellulose ester is kneaded at a desired melting temperature heated in the preheating process using a kneading screw having a compression ratio of 2 to 15 installed in a melt extruder. That is, in the present invention, the melting temperature of the cellulose ester of the present invention is preferably set to 180 ° C. to 250 ° C., more preferably 190 ° C. to 240 ° C., and further preferably 200 ° C. to 230 ° C. in order to eliminate die lines. When melted at a high temperature of 260 ° C. or higher, the cellulose ester of the present invention is decomposed, and thickness unevenness caused by a die line generated by the decomposition product remaining in the die can be reduced. However, when the melting temperature is lowered in this way, poor melting occurs, and this tends to cause shakiness. That is, in the present invention, it is also recommended to use a screw with a high compression ratio so as not to cause insolubility even at low temperatures. A preferable compression ratio is 3 to 15, more preferably 4 to 12, and more preferably 5 to 10. It is common to melt at a compression ratio of less than 3.

  In this case, the melting temperature may be a constant temperature, or may be carried out at a melting temperature obtained by being divided and controlled. More preferably, the temperature on the upstream side (hopper side) is higher by 1 ° C. to 50 ° C. than the temperature on the downstream side (T-die side), more preferably 2 ° C. to 30 ° C., and even more preferably 3 ° C. to 20 ° C. It is preferable because decomposition of the cellulose ester can be further suppressed. Preferably, in order to efficiently perform the melting, the temperature of the upstream portion of the liquid feeding is set higher, and after the melting, the temperature is lowered in order to suppress the decomposition of the cellulose ester. The kneading time is preferably 2 minutes to 60 minutes, more preferably 3 minutes to 40 minutes, and further preferably 4 minutes to 30 minutes. Furthermore, it is also preferable to carry out the inside of the melt extruder in an inert (nitrogen or the like) stream.

3) Cast Melted cellulose ester is passed through a gear pump to remove the pulsation of the extruder. Subsequently, filtration is performed with a metal mesh filter or the like. The mesh size is preferably 2 to 30 μm, more preferably 2 to 20 μm, and still more preferably 2 to 10 μm. At this time, it is preferable to pressurize and shorten the time required for filtration as much as possible. The filtration pressure is preferably 0.5 MPa to 15 MPa, more preferably 2 Pa to 15 MPa, and most preferably 10 Pa to 15 MPa. A higher filtration pressure is preferable because the filtration time can be shortened, but it is preferable to use a high pressure within a range in which the filter is not damaged. The temperature during filtration is preferably 180 ° C to 230 ° C, more preferably 180 ° C to 220 ° C, and further preferably 190 ° C to 220 ° C. If the temperature during filtration is less than or equal to the upper limit value, it is preferable because problems such as thermal degradation hardly occur. If the temperature is greater than or equal to the lower limit value, it takes too much time for filtration and inconvenience such as thermal degradation proceeds. Is preferable because it is difficult to cause. The time required for filtration should be as short as possible to prevent yellowing of the film. The amount of filtration per 1 cm 2 of filter is preferably 0.05 to 100 cm ³ , more preferably 0.1 to 100 cm ³ , and most preferably 0.5 to 100 cm ³ .

   Next, the sheet is extruded in a sheet form onto a cooling drum conveyed from a film forming die (T-type), but it is preferable to extrude from a T-die controlled to a temperature lower than the melting temperature as described above. It is possible to divide the melt temperature into a plurality of different temperatures in the melt extruder, and in this case, the melt temperature closest to the T-die is used as a reference. Thereafter, as described above, a constant distance (preferably 1 to 50 cm) is maintained between the T-die and the casting drum. At this time, it is preferable to put in the casing so that the temperature fluctuation during this period is small. Furthermore, in the present invention, it is preferable that the temperature of the T-die is lower by 5 ° C. to 30 ° C. than the melting temperature. This is characterized in that the temperature of the T-die is lowered in order to prevent it from staying on the T-die and decomposing and burning the cellulose ester, which causes die line. In ordinary film formation, it is common to level the generated die line by setting the melt die to the same temperature or higher from the melt-kneader to the T-die, and lowering the melt viscosity. In the case of melt film formation, it is effective to lower the temperature as described above.

  Moreover, in order to eliminate the horizontal dan (stepwise unevenness generated in the width direction) of the cellulose ester film, it is preferable in the present invention that the distance between the T-die and the casting drum be 2 cm to 50 cm. More preferably, they are 5 cm-40 cm, More preferably, they are 7 cm-35 cm. Usually, in order to prevent neck-in, the T-die and the casting drum are generally as close as possible. In the present invention, it is preferably close to 1 to 3 cm. In the present invention, since the cellulose ester is difficult to neck-in, it is preferable to widen the space between the casting drum and the T-die as described above. The temperature of the casting drum at this time is preferably (Tg-30 ° C) to Tg, more preferably (Tg-20 ° C) to (Tg-1 ° C), and still more preferably (Tg-15 ° C) to (Tg-2). ° C). Further, increasing the distance between the T-die and the casting drum in this manner also has an effect of leveling and reducing the die streaks. The Tg of the cellulose ester of the present invention is preferably 70 ° C to 180 ° C, more preferably 80 ° C to 160 ° C, and still more preferably 90 ° C to 150 ° C.

  Extrusion may be performed in a single layer, or multiple layers may be extruded using a multi-manifold die or a field block die. Thereafter, the resin is extruded onto a casting drum having an appropriately selected diameter (preferably 10 to 200 cm), number (preferably 2 to 20) and temperature (preferably Tg-30 ° C.). At this time, it is preferable to use a method such as an electrostatic application method, an air knife method, an air chamber method, a vacuum nozzle method, or a touch roll method to increase the adhesion between the casting drum and the melt-extruded sheet. Such an adhesion improving method may be performed on the front surface of the melt-extruded sheet or a part thereof.

  Next, it is preferable that the molten cellulose ester (melt) extruded from the T-die is as long as possible to cool and solidify on the casting drum. That is, the melt extruded at Tg or more from the T-die becomes below Tg and shrinks on the casting drum. At this time, since shrinkage in the in-plane direction is suppressed by friction between the melt and the casting drum, shrinkage in the thickness direction becomes dominant. That is, a plane orientation is formed here and Rth is expressed. If this contraction is abrupt, unevenness of Rth is likely to occur, and the point is to cool slowly as described above. That is, it is preferable to cool and solidify between (Tg + 30 ° C.) and Tg at a rate (solidification rate) of 10 ° C./second to 100 ° C./second, more preferable solidification rate is 15 ° C./second to 80 ° C./second, It is preferable to cool at 20 ° C./second to 60 ° C./second. In the case of a normal resin, it is solidified at 300 ° C./second or more, so the above range in the cooling of the present invention is a sufficiently slow cooling rate. Therefore, it is preferable to control the temperature between the casting drum and the T-die, and the preferable temperature is (Tg-30 ° C) to (Tg + 50 ° C), more preferably (Tg-20 ° C) to (Tg + 40 ° C), Preferably, it is (Tg-10 ° C) to (Tg + 30 ° C).

  In the present invention, the number of preferable casting drums is 2 to 10, more preferably 2 to 6, and further preferably 3 to 5. The temperatures of these casting drums may be the same or different. More preferably, the temperature of the most upstream casting drum is lower than that of the most downstream casting drum. When three or more are arranged, the casting drum temperature between them may be higher or lower than the temperature of the preceding roll. That is, the temperature at the uppermost stream and the most downstream position may be lowered, and the roll temperature therebetween may be set arbitrarily. The diameter of these casting drums is usually 20 cm to 200 cm. These film forming speeds are preferably formed at a speed of 15 m / min to 300 m / min. More preferably, it is 20 m / min-200 m / min, More preferably, it is 30 m / min-100 m / min.

After cooling, it is preferable that the cellulose ester film is peeled off from the casting drum, passed through a nip roll, cut with a nip roll, and then wound up at a winding tension of 0.01 kg / cm ^{2 to} 10 kg / cm ^2. , more preferably ^{0.10kg / cm 2 ~9kg / cm 2} , more preferably from ^{0.10kg / cm 2 ~9kg / cm 2} . The winding speed is preferably 10 m / min to 100 m / min, more preferably 15 m / min to 80 m / min, still more preferably 20 m / min to 70 m / min. The film forming width is preferably 1.5 m to 5 m, more preferably 1.6 m to 4 m, and still more preferably 1.7 m to 3 m. Since the sheet immediately after being peeled off from the casting drum has a temperature close to Tg, it is stretched by the winding tension to express Re and Rth, and this becomes more prominent at the end than at the center.

For this reason, Re and Rth develop parabolic unevenness. There is a method in which a nip roll is installed after the casting drum to cut the winding tension. However, the cutting cannot be completely cut, and the tension is slightly propagated to the sheet after the casting drum is peeled off. This causes Re and Rth unevenness. Such unevenness occurs over the entire width direction, so it is difficult to detect with a small size, and becomes a problem when a large size is cut out. For this reason, it is a point to wind up with the above weak tensions (normally, it winds at 20 kg / cm < ² > or more). Winding misalignment is likely to occur by winding at such a low tension, but this can be countered by applying knurling (thickening) processing to both ends. The thickness of the unstretched film thus obtained is preferably 30 μm to 400 μm, more preferably 40 μm to 200 μm, still more preferably 50 μm to 150 μm. Further, Re and Rth are preferably 0 nm to 100 nm, more preferably 0 nm to 50 nm, and still more preferably 0 nm to 25 nm.
The thickness unevenness of the unstretched film thus obtained uses a fluorine-based surfactant represented by any one of the general formulas (2A), (2B), (2C) and (2D) according to the present invention. Is significantly improved. The thickness unevenness of an unstretched film produced using a fluorosurfactant can usually be 3.5% or less, preferably 3% or less, more preferably 2% or less, and even more preferably 1 .5% or less, particularly preferably 1% or less.

  The above is an improvement measure of the present invention performed on an unstretched film, but by stretching the unstretched film obtained in this way, thickness unevenness, Re unevenness, Rth unevenness, Re, Rth A stretched film having a smaller humidity fluctuation can be obtained. The sheet thus obtained is preferably trimmed at both ends and wound up. The trimmed portion is re-processed as a raw material for the same type of film or as a raw material for a film of a different type after being pulverized or subjected to processing such as granulation or depolymerization / repolymerization as necessary. May be used. In addition, it is also preferable from the viewpoint of scratch prevention to attach a laminate film on at least one surface before winding.

4) Stretching Stretching is preferably performed at Tg to (Tg + 50 ° C.), more preferably (Tg + 1 ° C.) to (Tg + 30 ° C.), and further preferably (Tg + 2 ° C.) to (Tg + 20 ° C.). A preferable draw ratio is 1% to 500%, more preferably 3% to 400%, and still more preferably 5% to 300%. These stretching operations may be performed in one stage or in multiple stages. The draw ratio here is determined using the following equation.
Stretch ratio (%) = 100 × {(Length after stretching) − (Length before stretching)} / Length before stretching Such stretching is performed by using two or more pairs of nip rolls having a higher peripheral speed on the outlet side. The film may be stretched in the longitudinal direction (longitudinal stretching), or both ends of the film may be held by a chuck and spread in the orthogonal direction (perpendicular to the longitudinal direction) (lateral stretching). Generally, in either case, when the draw ratio is increased, both Re and Rth can be increased. Further, the ratio of Re and Rth can be freely controlled by controlling the value (aspect ratio) obtained by dividing the space between nip rolls by the film width in the case of longitudinal stretching. That is, the Rth / Re ratio can be increased by reducing the aspect ratio. In the case of lateral stretching, it can be controlled by stretching in the orthogonal direction and simultaneously stretching in the longitudinal direction, or conversely relaxing. That is, the Rth / Re ratio can be increased by stretching in the vertical direction, and the Rth / Re ratio can be decreased by relaxing in the vertical direction. Such stretching speed is preferably 10% / min to 10000% / min, more preferably 20% / min to 1000% / min, and further preferably 30% / min to 800% / min.

  In the present invention, the in-plane retardation (Re) is preferably 0 ≦ Re ≦ 200 nm, the thickness direction retardation (Rth) is −200 ≦ Rth ≦ 500 nm, and the film thickness is 40 to 150 μm. is there. More preferably, the in-plane retardation (Re) is 0 ≦ Re ≦ 150 nm, the thickness direction retardation (Rth) is −100 ≦ Rth ≦ 350 nm, and the film thickness is 40 to 120 μm. Further, in order to make the unevenness of Re, Rth, and thickness smaller, it is preferable to give a stretching gradient in the width direction in addition to using the raw material with less unevenness as described above. That is, in both the case of longitudinal stretching and the case of lateral stretching, stretching at both ends is likely to proceed, and Re and Rth are likely to be expressed. An edge part refers to the area | region of 10% with respect to a full width, and it can achieve this by making it 6 to 40 degreeC higher than a center part, More preferably 7 to 30 degreeC, More preferably, it makes 8 to 25 degreeC higher. In order to increase the temperature at both ends in this way, heat sources (panel heaters, infrared heaters, etc.) may be added to both ends, or hot air outlets may be added. By giving a temperature distribution in this way, more uniform stretching can be achieved than stretching at a constant temperature. Such a decrease is a phenomenon peculiar to a cellulose ester film.

  The film thickness after stretching is preferably 10 to 300 μm, more preferably 20 μm to 200 μm, and still more preferably 30 μm to 100 μm. The angle θ formed by the film forming direction (longitudinal direction) and the slow axis of Re of the film is preferably closer to 0 °, + 90 °, or −90 °. That is, in the case of longitudinal stretching, it is preferably as close to 0 °, preferably 0 ± 3 °, more preferably 0 ± 1.5 °, and further preferably 0 ± 0.5 °. In the case of transverse stretching, 90 ± 3 ° or −90 ± 3 ° is preferable, more preferably 90 ± 1.5 ° or −90 ± 1.5 °, and still more preferably 90 ± 0.5 ° or −90 ± 0. 5 °.

  Here, the cooling temperature after the heat treatment varies depending on the heat treatment temperature and the film thickness, but is usually air-cooled in a temperature range of −40 ° C. to (Tg−10) ° C. Preferably, it is 0-40 degreeC. Under the present circumstances, the temperature difference of cooling media, such as air which cools the surface of a film, and a back surface, affects the non-thermal deformation property of the obtained (biaxial) stretched film. When the temperature difference of the cooling gas is too large, the difference in thermal shrinkage between the front and back surfaces of the obtained (biaxial) stretched film is increased, the film is easily distorted during heating, warping is likely, and deformation is increased. Considering such points, it is preferable that the temperature difference between the cooling medium such as air for cooling the front and back surfaces of the film is small. However, in order to achieve the object of the present invention, the temperature difference is adjusted within 5 ° C. This is very important.

These stretched cellulose ester films before and after stretching preferably have a vertical and horizontal dimensional shrinkage of ± 0.1% or less at 105 ° C. for 5 hours, and dimensional shrinkage at 80 ° C. and 90% relative humidity. The rate is preferably less than ± 0.5% both vertically and horizontally, the haze is preferably 0.6% or less, the tear strength is preferably 10 g or more both vertically and horizontally, and the tensile strength is longitudinal. The width is preferably 50 N / mm ² or more, and the elastic modulus is preferably 3 kN / mm ² or more for both length and width.
These unstretched and stretched cellulose ester films may be used alone or in combination with a polarizing plate, and a liquid crystal layer or a layer with a controlled refractive index (low reflection layer) or hard A coat layer may be provided for use.

The thickness unevenness of the cellulose ester film after stretching is preferably 0% to 2% in both the thickness direction and the width direction, more preferably 0% to 1.5%, still more preferably 0% to 1%, and preferable Rth unevenness. Is preferably 0% to 10%, more preferably 0% to 7%, still more preferably 0% to 5%, and the preferred Re unevenness is preferably 0% to 10%, more preferably 0% to 7%. More preferably, it is 0% to 5%, and Re and Rth fluctuations with humidity are preferably 0% / relative humidity% to 1.5% / relative humidity%, more preferably 0% / relative humidity% to 1.2%. % / Relative humidity%, more preferably 0% / relative humidity% to 1% / relative humidity%. Such a stretched film can be achieved by stretching the unstretched film having the above properties. That is, a stretched film with small Re unevenness can be achieved by stretching an unstretched film (raw fabric) with small Re unevenness, and the same applies to Rth unevenness, thickness unevenness, and Re and Rth temperature changes.
In the present invention, by using a film with reduced thickness unevenness as described above, it is possible to perform uniform stretching in both thickness and retardation (the above-mentioned JP-A 2000-2000 in which the method of the present invention is not implemented). When a film having thickness unevenness as described in Japanese Patent No. 352620 is stretched, the thickness unevenness is easily amplified because the film is stretched from a mechanically weak thin area. The reverse is the case with such cellulose ester films).

<Modification of cellulose ester film>
Next, about the cellulose ester film of this invention, the preferable aspect in the case of providing a function further is described. First, a surface treatment method for a cellulose ester film will be described.
The cellulose ester film can achieve improved adhesion between the cellulose ester film and each functional layer (for example, the undercoat layer and the 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 also indicates so-called low temperature plasma that occurs under a low pressure gas of 10 ^{−3 to} 20 Torr, but may be a glow discharge treatment under atmospheric pressure.

First, glow discharge treatment under low pressure is described in U.S. Pat. Nos. 3,462,335, 3,761,299, 4,072,769 and British Patent 891,469. ing. In addition, a specific gas such as an inert gas, nitrogen oxides, or an organic compound gas is also introduced. When the surface of the polymer is subjected to a glow discharge treatment, it may be performed at atmospheric pressure or under reduced pressure. It may be carried out while introducing various gases and water such as oxygen, nitrogen, helium or argon into the atmosphere of the glow discharge treatment. The degree of vacuum during the glow discharge treatment is preferably 0.005 to 20 Torr, more preferably 0.02 to 2 Torr. The voltage is preferably between 500 and 5000V, more preferably between 500 and 3000V. The discharge frequency to be used is from DC to several thousand MHz, more preferably 50 Hz to 20 MHz, and further preferably 1 KHz to 1 MHz. The discharge treatment intensity is preferably 0.01 KV · A · min / m ^{2 to 5} KV · A · min / m ² , more preferably 0.15 KV · A · min / m ^{2 to 1} KV · A · min / m ² . is there.

Next, an ultraviolet irradiation method is also preferably used in the present invention. The mercury lamp used is a high-pressure mercury lamp made of a quartz tube and preferably has an ultraviolet wavelength of 180 to 380 nm. As for the method of ultraviolet irradiation, a high pressure mercury lamp with a dominant wavelength of 365 nm can be used as long as the surface temperature of the cellulose ester film rises to around 150 ° C. in terms of support performance. When low-temperature treatment is required, a low-pressure mercury lamp having a dominant wavelength of 254 nm is preferable. Ozone-less high-pressure mercury lamps and low-pressure mercury lamps can also be used. With regard to the amount of processed light, the greater the amount of processed light, the better the adhesion between the cellulose ester film and the adherend layer, but the problem arises that the support becomes colored and the support becomes brittle as the amount of light increases. Therefore, a high-pressure mercury lamp having a main wavelength of 365 nm has a good irradiation light quantity of 20 to 10000 (mJ / cm ² ), more preferably 50 to 2000 (mJ / cm ² ). In the case of low-pressure mercury lamp for a 254nm main wavelength, the irradiation light amount 100~10000 (mJ / cm ²⁾ C., more preferably 300~1500 (mJ / cm ^2).

Next, corona discharge treatment is also preferable as the surface treatment of the cellulose ester film. As the corona discharge treatment apparatus, a solid state corona treatment machine manufactured by Pillar, a LEPEL type surface treatment machine, a VETAPHON type treatment machine, or the like can be used. The treatment can be performed in air at normal pressure. The discharge frequency during the treatment is 5 to 40 KV, more preferably 10 to 30 KV, and the waveform is preferably an AC sine wave. The gap clearance between the electrode and the dielectric roll is 0.1 to 10 mm, more preferably 1.0 to 2.0 mm. The discharge is processed above a dielectric support roller provided in the discharge zone, and the treatment amount is 0.3 to 0.4 KV · A · min / m ² , more preferably 0.34 to 0.38 KV · A ·. Min / m ² .

Next, the flame treatment will be described. The gas used may be natural gas, liquefied propane gas, or city gas, but the mixing ratio with air is important. A preferable mixing ratio of natural gas / air is 1/6 to 1/10, preferably 1/7 to 1/9 by volume. In the case of liquefied propane gas / air, 1/14 to 1/22, preferably 1/16 to 1/19, and in the case of city gas / air, 1/2 to 1/8, preferably 1/3 to 1. / 7.
Further, the flame treatment amount is 1 to 50 Kcal / m ² , more preferably 3 to 20 Kcal / m ² .

  Moreover, the alkali saponification process preferably used as the surface treatment of the cellulose ester film will be specifically described. It is preferable that the cellulose ester film surface is immersed in an alkaline solution, then neutralized with an acidic solution, washed with water and dried. Examples of the alkaline solution include a potassium hydroxide solution and a sodium hydroxide solution, and the concentration of hydroxide ions is preferably 0.1 mol / L to 4.0 mol / L, preferably 0.5 mol / L to 3.5 mol. More preferably, it is / L. The alkaline solution temperature is preferably in the range of room temperature to 90 ° C, more preferably 40 ° C to 70 ° C. Next, it is generally washed with water, and then an acidic aqueous solution is passed through, followed by washing with water to obtain a surface-treated cellulose ester film.

  At this time, the acid is hydrochloric acid, nitric acid, sulfuric acid, acetic acid, formic acid, chloroacetic acid, oxalic acid, etc., and its concentration is preferably 0.01 mol / L to 3.0 mol / L, 0.05 mol / L More preferably, it is -2.0 mol / L. The alkali saponification time is preferably 20 to 600 seconds, more preferably 30 to 300 seconds, and particularly preferably 40 to 210 seconds. The neutralization is preferably carried out in 20 to 600 seconds, more preferably 30 to 250 seconds, and particularly preferably 40 to 180 seconds. Further, the washing with water is preferably performed in 20 to 400 seconds, more preferably 30 to 300 seconds, and particularly preferably 40 to 210 seconds.

The surface energy of the solid obtained by these methods can be determined by the contact angle method, the wet heat method, and the adsorption method as described in “Basics and Applications of Wetting” (issued by Realize 1989.12.10). The contact angle method is preferably used, and the contact angle of water is preferably 10 to 45 °, more preferably 10 to 40 °, and particularly preferably 10 to 30 °. In order to bond the cellulose ester film and the functional layer, after surface activation treatment, directly apply the functional layer on the cellulose ester film to obtain adhesive strength, and after some surface treatment Alternatively, there is a method in which an undercoat layer (adhesive layer) is provided and a functional layer is applied thereon without surface treatment.
Various contrivances have also been made for the constitution of the undercoat layer, and a layer that is often adjacent to the support (hereinafter abbreviated as the undercoat first layer) is provided as the first layer, and a functional layer is provided as the second layer thereon. There is a so-called multi-layer method in which an undercoat second layer that adheres well is applied.

  In the single layer method, good adhesion is often achieved by expanding the cellulose ester film and interfacial mixing with the undercoat layer material. Examples of the primer polymer used in the present invention include water-soluble polymers, cellulose esters, latex polymers, and water-soluble polyesters. Examples of water-soluble polymers include gelatin, gelatin derivatives, casein, agar, sodium alginate, starch, polyvinyl alcohol, polyacrylic acid copolymer, maleic anhydride copolymer, and cellulose esters such as carboxymethyl cellulose and hydroxyethyl cellulose. Etc. Examples of the latex polymer include a vinyl chloride-containing copolymer, a vinylidene chloride-containing copolymer, an acrylate ester-containing copolymer, a vinyl acetate-containing copolymer, and a butadiene-containing copolymer. In the first subbing layer in the multi-layer method, for example, a copolymer starting from a monomer selected from vinyl chloride, vinylidene chloride, butadiene, methacrylic acid, acrylic acid, itaconic acid, maleic anhydride and the like is used. As oligomers or polymers of polyethyleneimine, epoxy resin, grafted gelatin, nitrocellulose and the like.

  Moreover, as a preferable aspect, the cellulose-ester film of this invention is providing the hydrophilic binder layer for adhere | attaching with a polarizer. For example, a vinyl acetate-maleic acid copolymer compound containing -COOM group, or a hydrophilic cellulose derivative (for example, methyl cellulose, carboxymethyl cellulose, hydroxyalkyl cellulose, etc.), a polyvinyl alcohol derivative (for example, vinyl acetate-vinyl alcohol copolymer, Polyvinyl acetal, polyvinyl formal, polyvinyl benzal, etc.) natural polymer compounds (for example, gelatin, casein gum arabic, etc.), hydrophilic group-containing polyester derivatives (for example, sulfone group-containing polyester copolymers).

The undercoat layer optionally applied to the cellulose ester film of the present invention can contain inorganic or organic fine particles as a matting agent to such an extent that the transparency of the functional layer is not substantially impaired. Silica (SiO ₂ ), titanium dioxide (TiO ₂ ), calcium carbonate, magnesium carbonate and the like can be used as the inorganic fine particle matting agent. Examples of the organic fine particle matting agent include polymethyl methacrylate, cellulose acetate propionate, polystyrene, a treatment solution-soluble one described in US Pat. No. 4,142,894, and US Pat. No. 4,396,706. Polymers described in the specification can be used. These fine particle matting agents preferably have an average particle size of 0.01 to 10 μm. More preferably, it is 0.05-5 micrometers. Further, the content thereof is preferably 0.5~600mg / m ^2, is more preferably from 1 to 400 mg / m ^2. The undercoating liquid is generally a well-known coating method such as dip coating, air-knife coating, curtain coating, roller coating, wire bar coating, gravure coating, slide coating, or US Pat. , 681,294 specification, and can be applied by an extrusion coating method using a hopper.

In the configuration of the protective film for polarizing plate in which the cellulose ester film of the present invention is used, it is preferable that an antistatic layer is provided on at least one layer of the film or a hydrophilic binder layer for adhering to the polarizer is provided. First, the conductive layer of the present invention will be described below. As the conductive material, a conductive metal oxide or a conductive polymer is preferable. A transparent conductive film by vapor deposition or sputtering may be used. Examples of metal oxides are preferably ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, MoO ₂ , V ₂ O ₅ , or a composite oxide thereof. In particular, ZnO, SnO ₂ or V ₂ O ₅ is preferable. As examples of the hetero atoms of the composite oxide, addition of Al, In, Ta, Sb, Nb, halogen, and Ag is effective, and the addition amount is preferably in the range of 0.01 mol% to 25 mol%. The volume resistivity of these conductive metal oxide powders is 10 ⁷ Ω-cm, particularly 10 ⁵ Ω-cm or less, and the primary particle size is 100 to 0.2 μm. It is preferable that the conductive layer contains 0.01% to 20% by volume fraction of powder having a specific structure with a major structure having a major axis of 300 to 6 μm. The amount of the conductive fine particles is preferably 0.01~5.0g / m ^2, in particular 0.005~1g / m ² is preferred.

  The binder for dispersing the conductive fine particles is not particularly limited as long as it has a film-forming ability. For example, proteins such as gelatin and casein, carboxymethyl cellulose, hydroxyethyl cellulose, acetyl cellulose, diacetyl cellulose, and triacetyl cellulose. Cellulose compounds such as dextran, agar, sodium alginate, starch derivatives, etc., polyvinyl alcohol, polyvinyl acetate, polyacrylate ester, polymethacrylate ester, polystyrene, polyacrylamide, poly-N-vinylpyrrolidone, polyester, Examples thereof include synthetic polymers such as polyvinyl chloride and polyacrylic acid.

The ion conductive substance is a substance containing ions that are carriers that show electric conductivity and select electricity. As an example, a metal oxide sol containing an ionic polymer compound and an electrolyte can be given. The electrical resistance of these conductive layers is preferably 10 ¹² Ω (25 ° C., relative humidity 10%) or less, more preferably 10 ¹⁰ Ω or less, and particularly preferably 10 ⁹ Ω or less. Further, as the conductive material, an organic electron conductive material is also preferable, and examples thereof include a polyaniline derivative, a polythiophene derivative, a polypyrrole derivative, and a polyacetylene derivative.

In the use of the cellulose ester film of the present invention, a surfactant is preferably used. In the functional layer of the present invention, the surfactant is classified into a dispersant, a coating agent, a wetting agent, an antistatic agent, etc. depending on the purpose of use, but by appropriately using the surfactant described below, The goal can be achieved. As the surfactant used in the present invention, either nonionic or ionic (anion, cation, betaine) can be used. Further, a fluorine-based low molecular surfactant is preferably used as a coating agent in an organic solvent or as an antistatic agent. The layer used may be a layer made of cellulose ester, or any other functional layer. When used in optical applications, examples of the functional layer include an undercoat layer, an intermediate layer, an orientation control layer, a refractive index control layer, a protective layer, an antifouling layer, an adhesive layer, a back undercoat layer, and a back layer. Although the amount used is not particularly limited as long as it is an amount necessary to achieve the purpose, it is generally preferably 0.0001 to 5% by mass, more preferably 0.0005 to the mass of the layer to be added. 2% by mass is preferred. In this case, the coating amount is preferably 0.02 to 1000 mg, more preferably 0.05 to 200 mg per 1 m ² .

  Further, a slip agent may be contained in any layer on the cellulose ester film, and in that case, the outermost layer is particularly preferable. Examples of the slip agent used include polyorganosiloxanes disclosed in Japanese Patent Publication No. 53-292, higher fatty acid amides disclosed in US Pat. No. 4,275,146, Higher fatty acid esters (such as those having 10 to 24 carbon atoms and fatty acids such as those disclosed in JP-A-58-33541, British Patent No. 927,446 or JP-A-55-126238 and 58-90633). Esters of alcohols having 10 to 24 carbon atoms), and higher fatty acid metal salts as disclosed in US Pat. No. 3,933,516, and also disclosed in JP-A-58-50534 Esters of linear higher fatty acids and linear higher alcohols, branched alkyl groups as disclosed in WO 90108115.8 Higher alcohol esters and the like are known - higher fatty acids containing.

Among these, as polyorganosiloxane, in addition to polyalkylsiloxanes such as polydimethylsiloxane polydiethylsiloxane and polyarylsiloxanes such as polydiphenylsiloxane and polymethylphenylsiloxane, which are generally known, JP-B 53-292 No., JP-B-55-49294, JP-A-60-140341, etc., an organopolysiloxane having an alkyl group of C ₅ or more, an alkylpolysiloxane having a polyoxyalkylene group in the side chain, A modified polysiloxane such as an organopolysiloxane having an alkoxy, hydroxy, hydrogen, carboxyl, amino, or mercapto group in the side chain can be used, a block copolymer having a siloxane unit, or JP-A-60-191240. In Siloxane units as may be used graft polymer having a side chain. In coating the slip agent, it can be used together with a binder having a film forming ability. As such a polymer, known thermoplastic resins, thermosetting resins, radiation curable resins, reactive resins, mixtures thereof, and hydrophilic binders such as gelatin can be used. The sliding performance preferably has a coefficient of static friction of 0.25 or less, and the sample was conditioned at a temperature of 25 ° C. and a relative humidity of 60% for 2 hours and then measured with a HEIDON-10 static friction coefficient measuring machine using a 5 mmφ stainless steel ball. The smaller the value, the better the slipperiness.

In the functional layer of the cellulose ester film of the present invention, it is preferable to use a matting agent for improving the slipperiness of the film and the adhesion resistance under high humidity. In that case, the average height of the protrusions on the surface is preferably 0.005 to 10 μm, more preferably 0.01 to 5 μm. Further, it is better that there are a large number of protrusions on the surface. A preferable protrusion is within a range having an average height of the protrusion, for example, when the protrusion is formed with a spherical or irregular matting agent, the content is 0.5 to 600 mg / m ² , and more preferable. Is 1 to 400 mg / m ² . At this time, the matting agent to be used is not particularly limited in its composition, and may be inorganic or organic, or a mixture of two or more.
Inorganic and organic compounds of matting agents include fine powders of inorganic substances such as barium sulfate, manganese colloid, titanium dioxide, strontium barium sulfate, and silicon dioxide. Examples thereof include silicon dioxide such as synthetic silica and titanium dioxide (rutile type and anatase type) produced by titanium slug and sulfuric acid. It can also be obtained by pulverizing from an inorganic substance having a relatively large particle size, for example, 20 μm or more, followed by classification (vibration filtration, wind classification, etc.). Other examples include pulverized and classified products of organic polymer compounds such as polytetrafluoroethylene, cellulose acetate, polystyrene, polymethyl methacrylate, polypropyl methacrylate, polymethyl acrylate, polyethylene carbonate, and starch. Alternatively, a polymer compound synthesized by a suspension polymerization method, a polymer compound made spherical by a spray drying method or a dispersion method, or an inorganic compound can be used.

  The film of the present invention can be provided with a transparent hard coat layer. An actinic ray curable resin or a thermosetting resin is preferably used as the transparent hard coat layer. The actinic radiation curable resin layer refers to a layer mainly composed of a resin that is cured through a crosslinking reaction or the like by irradiation with actinic rays such as ultraviolet rays or electron beams. Typical examples of the actinic radiation curable resin include an ultraviolet curable resin and an electron beam curable resin, but a resin that is cured by irradiation with an actinic ray other than ultraviolet rays and electron beams may be used. Examples of the ultraviolet curable resin include an ultraviolet curable acrylic urethane resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, and an ultraviolet curable epoxy resin. be able to. In JP-A-2003-039014, the coated film is rolled and gripped in the width direction and dried, and a coating solution containing an actinic radiation curable substance is cured, and thus has high flatness. The invention has been described and is applicable to the present invention.

  The film of the present invention can be provided with an antireflection layer. Various configurations such as a single layer and a multilayer are known as the configuration of the antireflection layer, but a multilayer structure having a structure in which a high refractive index layer and a low refractive index layer are alternately laminated is generally used. Examples of the configuration include those composed of two layers of a high refractive index layer / low refractive index layer from the transparent substrate side, or three layers having different refractive indexes, a medium refractive index layer (transparent substrate or hard Layers with higher refractive index than coat layer and lower refractive index than high refractive index layer) / high refractive index layer / low refractive index layer, etc. Something to do is also proposed. Among these, from the viewpoint of durability, optical characteristics, cost, productivity, and the like, it is preferable to apply a high refractive index layer / medium refractive index layer / low refractive index layer in this order on a substrate having a hard coat layer.

  The optical film of the present invention can also be provided with an antiglare layer. The antiglare layer has a structure containing fine particles in the layer in order to have an antiglare function by scattering the light on the surface of the antiglare layer or inside the antiglare layer by giving the surface an uneven structure. Yes. Preferred configurations for these layers are as shown below. This is a layer having a film thickness of 0.5 to 5.0 μm and containing one or more kinds of fine particles having an average particle size of 0.25 to 10 μm. The average particle size is 1.1 to 2 times the film thickness. It is a layer containing silicon dioxide particles and silicon dioxide fine particles having an average particle size of 0.005 to 0.1 μm in a binder such as diacetyl cellulose, and can thereby exhibit an antiglare function. Examples of the “particles” include inorganic particles and organic particles.

  The optical film of the present invention can be subjected to anti-curl processing. Anti-curl processing gives the function of trying to curl with the surface to which it is applied inside, but by applying this processing, some surface processing is performed on one side of the transparent resin film, It works to prevent curling with the surface facing inward when different degrees and types of surface treatment are applied. The anti-curl layer may be provided on the side opposite to the side having the anti-glare layer or anti-reflection layer of the substrate, or, for example, an easy-adhesion layer may be coated on one side of the transparent resin film, and the anti-curl processing is performed on the opposite side. The mode which coats is mentioned.

<Utilization of cellulose ester film of the present invention>
Combining the cellulose ester film of the present invention with the functional layer described in detail on pages 32 to 45 of the Japan Institute of Invention Disclosure Technical Report (public technical number 2001-1745, issued March 15, 2001, Japan Society of Invention). Is preferred. Among these, application of a polarizing film (polarizing plate), application of an optical compensation layer (optical compensation sheet), and application of an antireflection layer (antireflection film) are preferable.

(1) Application of polarizing film (preparation of polarizing plate)
Currently, a commercially available polarizing film is generally produced by immersing a stretched polymer in a solution of iodine or dichroic dye in a bath and allowing the iodine or dichroic dye to penetrate into the binder. It is. The iodine and the dichroic dye in the polarizing film develop polarizing performance by being oriented in the binder. The dichroic dye preferably has a hydrophilic substituent (for example, sulfo, amino, hydroxyl). For example, the compounds described in page 58 of the Japan Society of Invention Disclosure Technique (Public Technical No. 2001-1745, published on March 15, 2001, Japan Society of Invention).

  As the binder for the polarizing film, either a polymer that can be crosslinked per se or a polymer that is crosslinked by a crosslinking agent can be used, and a plurality of combinations thereof can be used. Examples of the binder include a water-soluble polymer (for example, poly (N-methylolacrylamide), carboxymethylcellulose, gelatin, polyvinyl alcohol, modified polyvinyl alcohol) described in paragraph No. [0022] of JP-A-8-338913. Preferably, gelatin, polyvinyl alcohol and modified polyvinyl alcohol are more preferable, and polyvinyl alcohol and modified polyvinyl alcohol are most preferable. The modified polyvinyl alcohol is described in JP-A-8-338913, JP-A-9-152509, and JP-A-9-316127. The binder thickness is preferably 1 to 50 μm, more preferably 2 to 50 μm, and further 5 to 30 μm. The binder of the polarizing film may be cross-linked. Crosslinkable boron compounds (for example, boric acid and borax) can also be used as a crosslinking agent. The addition amount of the crosslinking agent in the binder is preferably 0.1 to 20% by mass with respect to the binder.

The polarizing film is preferably dyed with iodine or a dichroic dye after the polarizing film is stretched (stretching method) or rubbed (rubbing method).
In the stretching method, the stretching ratio is preferably 2.5 to 30.0 times, and more preferably 3.0 to 10.0 times. For the stretching, a parallel stretching method, or a method of stretching using a tenter projecting in an oblique direction as described in JP-A-2002-86554 can be used. The saponified cellulose ester film and a polarizing film prepared by stretching are bonded to prepare a polarizing plate. The laminating direction is preferably performed so that the casting axis direction of the cellulose ester film and the stretching axis direction of the polarizing plate are 45 degrees. The bonding adhesive is not particularly limited, and examples thereof include PVA resins (including modified PVA such as acetoacetyl group, sulfonic acid group, carboxyl group, oxyalkylene group) and boron compound aqueous solution. preferable. The thickness of the adhesive layer is preferably 0.01 to 10 μm, and particularly preferably 0.05 to 5 μm after drying.

(2) Application of optical compensation layer (creation of optical compensation sheet)
The optically anisotropic layer is for compensating the liquid crystal compound in the liquid crystal cell in the black display of the liquid crystal display device, forms an alignment film on the cellulose ester film, and further provides an optically anisotropic layer. Is formed. An alignment film is provided on the surface-treated cellulose ester film. This film has a function of defining the alignment direction of liquid crystalline molecules. However, if the alignment state is fixed after aligning the liquid crystalline compound, the alignment film plays the role, and thus is not necessarily an essential component of the present invention. That is, it is possible to produce the polarizing plate of the present invention by transferring only the optically anisotropic layer on the alignment film in which the alignment state is fixed onto the polarizer. The alignment film is an organic compound (for example, ω-tricosanoic acid) formed by rubbing treatment of an organic compound (preferably polymer), oblique deposition of an inorganic compound, formation of a layer having a microgroove, or Langmuir-Blodgett method (LB film). , Dioctadecylmethylammonium chloride, methyl stearylate). Furthermore, an alignment film in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known.

  The alignment film is preferably applied by spin coating, dip coating, curtain coating, extrusion coating, rod coating, or roll coating. A rod coating method is particularly preferable. The film thickness after drying is preferably 0.1 to 10 μm. Heating and drying can be performed at 20 ° C to 110 ° C. In order to form sufficient cross-linking, 60 ° C to 100 ° C is preferable, and 80 ° C to 100 ° C is particularly preferable. The drying time can be 1 minute to 36 hours, preferably 1 minute to 30 minutes. The pH is preferably set to an optimum value for the crosslinking agent to be used. When glutaraldehyde is used, the pH is 4.5 to 5.5, and 5 is particularly preferable. The thickness of the alignment film thus obtained is preferably in the range of 0.1 to 10 μm.

Next, the liquid crystalline molecules of the optically anisotropic layer are aligned on the alignment film. Thereafter, as necessary, the alignment film polymer and the polyfunctional monomer contained in the optically anisotropic layer are reacted, or the alignment film polymer is crosslinked using a crosslinking agent.
The liquid crystalline molecules used in the optically anisotropic layer include rod-like liquid crystalline molecules and discotic liquid crystalline molecules. The rod-like liquid crystal molecules and the disk-like liquid crystal molecules may be high-molecular liquid crystals or low-molecular liquid crystals, and further include those in which low-molecular liquid crystals are cross-linked and no longer exhibit liquid crystallinity.
(Rod-like liquid crystalline molecules)
The rod-like liquid crystal molecule may be bonded to a (liquid crystal) polymer.
For rod-like liquid crystalline molecules, see Chapter 4, Chapter 7 and Chapter 11 of the Chemical Chemistry of the Quarterly Chemical Review Vol. 22, Liquid Crystal Chemistry (1994), and the 142nd Committee of the Japan Society for the Promotion of Science. Described in Chapter 3. The birefringence of the rod-like liquid crystal molecule is preferably in the range of 0.001 to 0.7. The rod-like liquid crystalline molecule preferably has a polymerizable group in order to fix its alignment state. The polymerizable group is preferably a radically polymerizable unsaturated group or a cationically polymerizable group. Specifically, for example, the polymerizable group described in paragraphs [0064] to [0086] of JP-A-2002-62427, A polymerizable liquid crystal compound is mentioned.

(Discotic liquid crystalline molecules)
As a discotic liquid crystalline molecule, a compound having liquid crystallinity having a structure in which a linear alkyl group, an alkoxy group, and a substituted benzoyloxy group are radially substituted as a side chain of the mother nucleus with respect to the mother nucleus at the center of the molecule Is also included. The molecule or the assembly of molecules is preferably a compound that has rotational symmetry and can give a certain orientation. In the optically anisotropic layer formed from the discotic liquid crystalline molecules, the compound finally contained in the optically anisotropic layer does not need to be a discotic liquid crystalline molecule. Also included are compounds that have a group that reacts with heat or light, and that eventually polymerize or cross-link by reaction with heat or light to increase the molecular weight and lose liquid crystallinity. Preferred examples of the discotic liquid crystalline molecules are described in JP-A-8-50206. The polymerization of discotic liquid crystalline molecules is described in JP-A-8-27284. In order to fix the discotic liquid crystalline molecules by polymerization, it is necessary to bond a polymerizable group as a substituent to the discotic core of the discotic liquid crystalline molecules. A compound in which the discotic core and the polymerizable group are bonded via a linking group is preferable, whereby the orientation state can be maintained even in the polymerization reaction. For example, compounds described in paragraph numbers [0151] to [0168] of JP-A No. 2000-155216 are exemplified.

(Other composition of optically anisotropic layer)
Along with the liquid crystal molecules, a plasticizer, a surfactant, a polymerizable monomer, etc. can be used in combination to improve the uniformity of the coating film, the strength of the film, the orientation of the liquid crystal molecules, and the like. It is preferable that the liquid crystal molecules have compatibility with the liquid crystal molecules and can change the tilt angle of the liquid crystal molecules or do not inhibit the alignment.

(Formation of optically anisotropic layer)
The optically anisotropic layer can be formed by applying a coating liquid containing liquid crystalline molecules and, if necessary, a polymerization initiator described later and optional components on the alignment film. The thickness of the optically anisotropic layer is preferably 0.1 to 20 μm, more preferably 0.5 to 15 μm, and most preferably 1 to 10 μm. The aligned liquid crystal molecules can be fixed while maintaining the alignment state. The immobilization is preferably performed by a polymerization reaction. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator. A photopolymerization reaction is preferred.

  It is also preferable to combine this optical compensation film and a polarizing film. Specifically, the optically anisotropic layer is formed by applying the coating liquid for the optically anisotropic layer as described above to the surface of the polarizing film. As a result, without using a polymer film between the polarizing film and the optically anisotropic layer, a thin polarizing plate having a small stress (strain × cross-sectional area × elastic modulus) associated with the dimensional change of the polarizing film is produced. . When the polarizing plate according to the present invention is attached to a large liquid crystal display device, an image with high display quality can be displayed without causing problems such as light leakage. The tilt angle of the polarizing film and the optical compensation layer may be stretched so as to match the angle formed by the transmission axis of the two polarizing plates bonded to both sides of the liquid crystal cell constituting the LCD and the vertical or horizontal direction of the liquid crystal cell. preferable. A normal inclination angle is 45 °. Recently, however, devices that are not necessarily 45 ° have been developed for transmissive, reflective, and transflective LCDs, and it is preferable that the stretching direction can be arbitrarily adjusted in accordance with the design of the LCD.

<Use in liquid crystal display>
(General liquid crystal display device configuration)
The cellulose ester film can be used in various applications. The cellulose ester film of the present invention is effective when used as an optical compensation sheet for liquid crystal display devices. When the film itself is used as an optical compensation sheet, the transmission axis of the polarizing element (described later) and the slow axis of the optical compensation sheet made of a cellulose ester film are arranged so as to be substantially parallel or perpendicular. Is preferred. Such an arrangement of the polarizing element and the optical compensation sheet is described in JP-A-10-48420. The liquid crystal display device includes a liquid crystal cell having a liquid crystal supported between two electrode substrates, two polarizing elements disposed on both sides thereof, and at least one sheet between the liquid crystal cell and the polarizing element. An optical compensation sheet is arranged.

The liquid crystal layer of the liquid crystal cell is usually formed by sealing liquid crystal in a space formed by sandwiching a spacer between two substrates. The transparent electrode layer is formed on the substrate as a transparent film containing a conductive substance. The liquid crystal cell may further be provided with a gas barrier layer, a hard coat layer, or an undercoat layer (used for adhesion of the transparent electrode layer). These layers are usually provided on the substrate. The substrate of the liquid crystal cell generally has a thickness of 80 to 500 μm.
The optical compensation sheet is a birefringent film for removing the coloration of the liquid crystal screen. The cellulose ester film itself of the present invention can be used as an optical compensation sheet. Further, the function may be imparted as an antireflection layer, an antiglare layer, a λ / 4 layer or a biaxially stretched cellulose ester film. In addition, in order to improve the viewing angle of the liquid crystal display device, the cellulose ester film of the present invention and a film exhibiting birefringence opposite to that (positive / negative relationship) may be used as an optical compensation sheet. The thickness range of the optical compensation sheet is the same as the preferable thickness of the film of the present invention described above.

Examples of the polarizing film of the polarizing element include an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film. Any polarizing film is generally manufactured using a polyvinyl alcohol film. The protective film of the polarizing plate preferably has a thickness of 25 to 350 μm, and more preferably 40 to 200 μm. The liquid crystal display device may be provided with a surface treatment film. The functions of the surface treatment film include hard coat, anti-fogging treatment, anti-glare treatment and antireflection treatment.
As described above, there has also been proposed an optical compensation sheet in which an optically anisotropic layer containing a liquid crystal (particularly a discotic liquid crystal molecule) is provided on a support (Japanese Patent Laid-Open Nos. 3-9325 and 6-148429). Nos. 8-50206 and 9-26572). The cellulose ester film of the present invention can also be used as a support for such an optical compensation sheet.

(Optically anisotropic layer containing discotic liquid crystalline molecules)
The optically anisotropic layer is preferably a layer containing discotic liquid crystal molecules that are tilted and aligned. The angle formed by the disc surface of the discotic liquid crystal molecule and the support surface is preferably changed (hybrid alignment) in the depth direction of the optically anisotropic layer. The optical axis of the discotic liquid crystalline molecule exists in the normal direction of the disk surface. The discotic liquid crystalline molecule has birefringence in which the refractive index in the disc surface direction is larger than the refractive index in the normal direction of the disc surface. The discotic liquid crystalline molecules may be aligned substantially horizontally with respect to the support surface.

(VA type liquid crystal display device)
The cellulose ester film of the present invention is also effectively used as a support for an optical compensation sheet of a VA liquid crystal display device having a VA mode liquid crystal cell. In the optical compensation sheet used for the VA liquid crystal display device, it is preferable that the direction in which the absolute value of retardation is minimum does not exist in the plane of the optical compensation sheet or in the normal direction. The optical properties of the optical compensation sheet used in the VA liquid crystal display device are determined by the optical properties of the optically anisotropic layer, the optical properties of the support, and the arrangement of the optically anisotropic layer and the support. . When two optical compensation sheets are used in the VA liquid crystal display device, the in-plane retardation of the optical compensation sheet is preferably in the range of −5 nm to 5 nm. Therefore, the absolute value of the in-plane retardation of each of the two optical compensation sheets is preferably 0 to 5.

  When one optical compensation sheet is used in the VA liquid crystal display device, it is preferable that the in-plane retardation of the optical compensation sheet be in the range of −10 nm to 10 nm. What is necessary is just to provide the optical characteristic corresponding to various VA cells so that it may become such an optical characteristic range. The range corresponds to the cell gap, and in the single-sheet cellulose ester film, Re is 40 to 120 nm, preferably Re is 50 to 100 nm, and particularly 50 to 90 nm. Further, Rth is 160 to 300 nm, preferably Rth is 170 to 260 nm, particularly 180 to 240 nm. Further, when two optical compensation sheets are used in the VA liquid crystal display device, the cellulose ester film of the present invention may be provided with optical characteristics corresponding to various VA cells. The range corresponds to the cell gap, and in the double-type cellulose ester film, Re is 20 to 80 nm, preferably Re is 30 to 70 nm, and particularly 30 to 60 nm. Rth is 80 to 200 nm, preferably Rth is 90 to 180 nm, and particularly 95 to 165 nm.

(OCB type liquid crystal display device and HAN type liquid crystal display device)
The cellulose ester film of the present invention is also advantageously used as a support for an optical compensation sheet of an OCB type liquid crystal display device having an OCB mode liquid crystal cell or a HAN type liquid crystal display device having a HAN mode liquid crystal cell. In the optical compensation sheet used for the OCB type liquid crystal display device or the HAN type liquid crystal display device, it is preferable that the direction in which the absolute value of retardation is minimum does not exist in the plane of the optical compensation sheet or in the normal direction. The optical properties of the optical compensation sheet used in the OCB type liquid crystal display device or the HAN type liquid crystal display device are also the optical properties of the optical anisotropic layer, the optical properties of the support, and the optical anisotropic layer and the support. Is determined by the arrangement of The cellulose ester film of the present invention may have optical properties corresponding to various OCB mode liquid crystal cells. The range is that Re is 20 to 100 nm, preferably Re is 30 to 80 nm, and particularly 30 to 60 nm. Further, Rth is 150 to 300 nm, preferably Rth is 160 to 260 nm, particularly 170 to 250 nm.

(Other liquid crystal display devices)
The cellulose ester film of the present invention is also advantageously used as a support for an optical compensation sheet of an ASM type liquid crystal display device having an ASM (Axially Symmetric Alligned Microcell) mode liquid crystal cell. The ASM mode liquid crystal cell is characterized in that the thickness of the cell is maintained by a resin spacer whose position can be adjusted. Other properties are the same as those of the TN mode liquid crystal cell. The ASM mode liquid crystal cell and the ASM type liquid crystal display device are described in a paper by Kume et al. (Kume et al., SID 98 Digest 1089 (1998)). The cellulose ester film of the present invention may be used as a support for an optical compensation sheet of a TN type liquid crystal display device having a TN mode liquid crystal cell. TN mode liquid crystal cells and TN type liquid crystal display devices have been well known for a long time. The optical compensation sheet used for the TN liquid crystal display device is described in JP-A-3-9325, JP-A-6-148429, JP-A-8-50206, and JP-A-9-26572. For the optical compensation sheet for these various liquid crystal display devices, the cellulose ester of the present invention may have a desired range of optical properties.

<Measurement method and evaluation method>
The measurement method and evaluation method regarding the cellulose ester film are described below. Further, an additional characteristic evaluation method will be described later.

(Re and Rth and Re and Rth fluctuations with humidity)
After the cellulose ester film was conditioned for 24 hours at 25 ° C. and 60% relative humidity, the film was measured at 25 ° C. and 60% relative humidity using an automatic birefringence meter (KOBRA-21ADH: manufactured by Oji Scientific Instruments). In-plane retardation is measured by measuring the phase difference value at a wavelength of 590 nm from the direction normal to the surface and the tilt direction in increments of 10 ° from + 50 ° to −50 ° from the film normal with the slow axis as the rotation axis. The value (Re) and the retardation value (Rth) in the film thickness direction were calculated. Unless otherwise specified, Re and Rth refer to this value.

Further, these samples were similarly measured at 25 ° C. and 10% relative humidity, and Re (10% RH) and Rth (10% RH) were obtained. Further, these samples were similarly measured at 25 ° C. and a relative humidity of 80%, and Re (80% RH) and Rth (80% RH) were obtained. For each sample, humidity Re fluctuation and humidity Rth fluctuation were determined according to the following formula.
Humidity Re variation (% / relative humidity%) = [100 × {absolute value of difference between Re (80% RH) and Re (10% RH)} / Re (60% RH)] / 70
Humidity Rth variation (% / relative humidity%) = [100 × {absolute value of difference between Rth (80% RH) and Rth (10% RH)} / Rth (60% RH)] / 70

(Re unevenness, Rth unevenness, uneven thickness)
In the MD direction sampling, sampling was performed at a size of 100 points and 1 cm square at 1 m intervals in the longitudinal direction. The sampling in the TD direction was sampled at an equal interval of 5 cm in a size of 1 cm square over the entire width of the film formation.
The difference between each maximum value and the minimum value of each sample obtained was divided by each average value, and those expressed as percentages were defined as Re unevenness and Rth unevenness. The thickness unevenness was also measured by measuring the thickness of each sample, and the difference between the maximum value and the minimum value in the MD direction and the TD direction was divided by each average value, and the percentage was determined as the thickness unevenness.

(Photoelastic coefficient)
(A) Two types of 1 cm wide × 10 cm long films were cut so that the longitudinal direction was the MD direction and the TD direction.
(B) Set this on an ellipsometer (M-150 manufactured by JASCO Corporation) and apply a load of 100 g, 200 g, 300 g, 400 g, and 500 g along the longitudinal direction (10 cm length) in sequence at 25 ° C. and relative humidity. Re was measured with 632.8 nm light at 60%.
(C) The stress (value divided by the film cross-sectional area (kgf / cm ² )) is plotted on the horizontal axis, and the Re change (nm) is plotted on the vertical axis, and the photoelasticity (cm ² / kgf) is obtained from this slope. It was.
(D) The measured values of the two types of samples were averaged to obtain photoelasticity (cm ² / kgf).

(Substitution degree of cellulose ester)
The degree of substitution of the acyl group with respect to the hydroxyl group of cellulose is described in Carbohydr. Res. Was determined by ¹³ C-NMR according to the method described in 273 (1995) 83-91 (Tezuka et al.).
(Degree of polymerization of cellulose ester)
About 0.2 g of completely dried cellulose ester was precisely weighed and dissolved in 100 ml of a mixed solvent of methylene chloride: ethanol = 9: 1 (mass ratio). This was measured with an Ostwald viscometer for the number of seconds dropped at 25 ° C., and the degree of polymerization was determined by the following equation.
ηrel = T / T0 T: The number of seconds of dropping of the measurement sample [η] = (1 nηrel) / C T0: The number of seconds of dropping of the solvent alone
DP = [η] / Km C: concentration (g / l)
Km: 6 × 10 ^-4

(Haze)
A sample of 40 mm × 80 mm was measured according to JIS K-6714 using a haze meter (HGM-2DP, Suga Test Instruments) at 25 ° C. and a relative humidity of 60%.
(Transparency)
The transparency of visible light (615 nm) was measured for a sample of 20 mm × 70 mm at 25 ° C. and a relative humidity of 60% using a transparency measuring device (AKA photoelectric tube colorimeter, KOTAKI Corporation).
(Molecular orientation axis)
Sample 70mm x 100mm was conditioned for 2 hours at 25 ° C and relative humidity 65%, and the phase difference when the incident angle at normal incidence was changed using an automatic birefringence meter (KOBRA21DH, Oji Scientific Co., Ltd.) The molecular orientation axis was calculated by measurement.

(Axis misalignment)
Using an automatic birefringence meter (KOBRA-21ADH, Oji Scientific Instruments Co., Ltd.), a sample misalignment angle of 70 mm × 100 mm was measured. Twenty points were measured at equal intervals over the entire width in the width direction, and the average absolute value was determined. The range of the slow axis angle (axis deviation) is the measurement of 20 points at equal intervals over the entire width direction, and the difference between the average of the absolute value of the axis deviation and the average of the four points from the smaller absolute value. Is taken.
(Tear strength)
A sample 50 mm × 64 mm was conditioned at 23 ° C. and relative humidity 65% for 2 hours, and the load required for tearing was measured according to ISO 6383 / 2-1983 using a light load tear strength tester (Toyo Seiki Seisakusho). Evaluation was performed by averaging in the TD direction.

(Folding strength)
A sample 120 mm × 120 mm was conditioned for 2 hours at 23 ° C. and a relative humidity of 65%, and the number of reciprocations until it was cut by bending according to ISO8776-1988 was measured.
(Kisimi)
Samples 100 mm × 200 mm and 75 mm × 100 mm were conditioned at 23 ° C. and 65% relative humidity for 2 hours, and a large film was placed on the table using a Tensilon tensile tester (RTA-100, Orientec Co., Ltd.). A small film with a 200 g weight was fixed. We pulled the weight horizontally and measured the force when moving and the force when moving. Then, the static friction coefficient and the dynamic friction coefficient were calculated according to the following equations, respectively.
F = μ × W (W: weight of weight (kgf))
(Dynamic friction (steel ball method))
A 35mm x 100mm sample was conditioned for 2 hours at 23 ° C and 65% relative humidity. Using a dynamic friction coefficient measuring instrument (Toyo Baldwin), the sample was fixed on the table with the measurement surface facing up, and the steel ball was placed on the sample. Grated and measured the feed.

(Alkaline hydrolyzable)
A sample 100 mm × 100 mm was measured at 60 ° C. with an automatic alkali saponification treatment apparatus (Shinto Kagaku Co., Ltd.)
The mixture was saponified with a 2 mol / L aqueous sodium hydroxide solution for 3 minutes, washed with water for 4 minutes, neutralized with 30 mol, 0.01 mol / L dilute nitric acid for 4 minutes, and washed with water for 4 minutes. Then, it dried at 100 degreeC for 3 minutes, and also performed natural drying for 1 hour, and evaluated alkali hydrolyzability from the following visual reference | standard and the haze value before and behind a saponification process (25 degreeC and 60% of relative humidity).
A: No whitening was observed.
B: Slight whitening was observed.
C: Fair whitening was observed.
D: Remarkable whitening was observed.

(Curl value)
Sample 35mm x 3mm was conditioned for 24 hours at 25%, 55% and 85% relative humidity in a curl humidity control tank (HEIDON (No. YG53-168), Shinto Kagaku Co., Ltd.), and the radius of curvature was curled. Measured with In addition, curling with wet was measured after standing for 30 minutes in water having a water temperature of 25 ° C.
(Moisture and heat resistance)
A sample of 35 mm x 25 mm was aged for 200, 500, and 1000 hours at 85 ° C and 90% relative humidity, respectively, and two samples were bonded with an adhesive using Platinum Rainbow (PR-1G, Tabai Espec). The humidity was adjusted by pasting, the state of the sample was visually observed, the change in color was measured, and the following criteria were evaluated.
A: No particular abnormality is observed.
B: Decomposition odor or shape change due to decomposition is observed.

(Moisture content)
A 7 mm × 35 mm sample was measured by a Karl Fischer method using a moisture measuring device and a sample drying apparatus (CA-03, VA-05, both Mitsubishi Chemical Corporation). The moisture content (g) was calculated by dividing by the sample mass (g).
(Residual solvent amount)
Using a gas chromatography (GC-18A, Shimadzu Corporation), the amount of base residual solvent of a sample 7 mm × 35 mm was measured.

(Heat shrinkage)
Sample 30 mm x 120 mm was aged for 24 hours and 120 hours at 90 ° C and 5% relative humidity, and automatic pin gauges (Shinto Kagaku Co., Ltd.) were used to open 6mmφ holes at both ends at 100mm intervals. L1) was measured to a minimum scale of 1/1000 mm. Further, heat treatment was performed at 90 ° C. and 5% relative humidity for 24 hours and 120 hours, and the dimension (L2) of the punch interval was measured. The thermal contraction rate was determined by {(L1-L2) / L1} × 100.

(Moisture permeability, moisture permeability coefficient)
A 70 mmφ sample was conditioned at 25 ° C./90% relative humidity and 40 ° C./90% relative humidity for 24 hours, respectively, with a moisture permeation tester (KK-70907, Toyo Seiki Co., Ltd.) according to JIS Z-0208 The amount of water (g / m ² ) per unit area was calculated. And the water vapor transmission rate was calculated | required by the mass before humidity-mass before humidity control. Further, as a compulsory evaluation, the moisture permeability coefficient was measured after conditioning for 24 hours at 60 ° C. and 95% relative humidity.
(Foreign substance inspection)
Reflected light was applied to a range of the entire width of the sample × 1 m to visually detect foreign matter in the film, and then the foreign matter (lint) was confirmed and evaluated with a polarizing microscope.

(Dimensional stability)
The dimensional stability was evaluated by the heat shrinkage rate. Three test pieces each having a width of 30 mm and a length of 120 mm were collected from the vertical and horizontal directions of the sample. Holes of 6 mmφ were punched at both ends of the test piece at 100 mm intervals. This was conditioned for 3 hours or more in a room at 23 ± 3 ° C. and a relative temperature of 65 ± 5%. Using an automatic pin gauge (manufactured by Shinto Kagaku Co., Ltd.), the original size (L1) of the punch interval was measured to the minimum scale / 1000 mm. Next, the test piece was suspended in a thermostat at 80 ° C. ± 1 ° C. and heat-treated for 3 hours, adjusted to a humidity of 23 ± 3 ° C. and a relative humidity of 65 ± 5% for 3 hours or more, and then subjected to heat treatment with an automatic pin gauge. The dimension (L2) of the punch interval was measured. And the thermal contraction rate was computed by the following formula | equation.
Thermal contraction rate = (L1-L2 / L1) × 100

(Elastic modulus)
Using Toyo Baldwin Universal Tensile Tester STM T50BP, the stress at 0.5% elongation was measured at 23%, 70% atmosphere at a pulling rate of 10% / min, to determine the elastic modulus.
(Measurement of bright spot foreign matter)
Two polarizing plates were placed in an orthogonal state (crossed Nicols) to block transmitted light, and each sample was placed between the two polarizing plates. The polarizing plate used was a glass protective plate. Light was irradiated from one side, and the number of bright spots having a diameter of 0.01 mm or more per 1 cm ² was counted with an optical microscope (50 times) from the opposite side.
(Measurement of Tg)
20 mg of a sample was placed in a DSC measurement pan. This was heated from 30 ° C. to 250 ° C. at 10 ° C./min in a nitrogen stream and then cooled to 30 ° C. at −10 ° C./min. Thereafter, the temperature was raised again from 30 ° C. to 250 ° C., and the temperature at which the baseline started to deviate from the low temperature side was defined as Tg.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

Example 1
(1-1) Film formation of unstretched cellulose ester film (1) Preparation of cellulose ester pellet As a cellulose ester, cellulose ester A (acetyl substitution degree 1.00, butyryl substitution degree 1.70, total substitution degree 2.70, A powder having a viscosity average degree of polymerization of 220, a water content of 0.2% by mass, a viscosity of 190% by weight of 6% by mass in a dichloromethane solution, and an average particle size of 1.5 mm and a standard deviation of 0.5 mm was used. Cellulose ester A has a residual acetic acid content of 0.1% by mass or less, a residual butanoic acid content of 0.1% by mass or less, a Ca content of 80 ppm, a Mg content of 22 ppm, and a Fe content of 0.5 ppm. Furthermore, it contained 105 ppm of sulfur as sulfate groups.

  The substitution degree of the 6-position acetyl group was 0.33, and the substitution degree of the 6-position butyryl group was 0.57, which was 33% of the total acetyl. The methanol extract was 5% by mass or less, and the weight average molecular weight / number average molecular weight ratio was 2.8. The obtained cellulose ester A was formed into a solution on a glass plate using methylene chloride / methanol = 90/10 (mass ratio) to obtain a film having a thickness of 80 μm. The film consisting of cellulose ester A alone had a yellow index of 1.6, a haze of 0.07, a transparency of 92.9%, and a Tg (glass transition temperature; measured by DSC) of 128 ° C. This cellulose ester A was synthesized using cellulose collected from cotton as a raw material.

  After the cellulose ester A was dried at 120 ° C. for 3 hours and the water content was adjusted to 0.1% by mass or less, the fluorosurfactant of the present invention or comparative compounds (Comparative AD) are shown in Table 1. Add as it is (addition amount is part by mass with respect to the solid content of cellulose ester), 0.05 part by mass of silicon dioxide part particles (Aerosil R972V) (with respect to cellulose ester), and N, N ′, N ″ -Tri-m-toluyl-1,3,5-triazine-2,4,6-triamine was added in an amount of 4% by weight based on the cellulose ester. These were mixed and put into a hopper of a twin-screw kneading extruder, and further kneaded and melted at 200 ° C. with a screw rotation speed of 200 rpm and a residence time of 20 seconds. Furthermore, it was extruded into a strand having a diameter of 3 mm in a water bath, immersed for 1 minute (strand solidification), passed through 10 ° C. water for 30 seconds, lowered in temperature, and cut into a length of 5 mm to obtain a pellet. The obtained pellets made of cellulose ester A were dried at 100 ° C. for 10 minutes, and then stored in a moisture-proof bag made of a laminate film having aluminum.

(2) Filtration The cellulose ester formed into a cylindrical pellet having a diameter of 3 mm and a length of 5 mm was dried with a vacuum dryer at 110 ° C. for 3 hours. This was put into a hopper and melted at 200 ° C., followed by pressure filtration at a rate of 0.1 m / min at 10 MPa using a sintered metal filter having a diameter of 5 μm. It was confirmed that the obtained filtrate had a transparent and homogeneous composition.

(3) Melt film formation This is put into a hopper adjusted to be 118 ° C. (Tg−10 ° C.), and has an upstream melting temperature of 180 ° C., an intermediate melting temperature of 180 ° C., a downstream melting temperature of 180 ° C., and a compression ratio of 14 The T-die temperature is Tg-7 ° C, the distance between the T-die and the casting drum is 8cm, the solidification speed is 30 ° C / sec, the casting drum temperature is the first roll (upstream) (Tg-10) ° C, and the second roll (upstream). It was (Tg-11) ° C. and the third roll (upstream) (Tg-12) ° C., and the cooling rate was −15 ° C./second. The melt was melt extruded over 10 minutes. At this time, each level electrostatic application method (a 10 kV wire was placed 10 cm from the point where the melt was attached to the casting drum) was used. The solidified melt was peeled off and wound with a winding tension of 6 kg / cm ² via a nip roll. In addition, after trimming both ends (each 3% of the total width) immediately before winding, the both ends were subjected to thicknessing processing (knurling) having a width of 10 mm and a height of 50 μm, and then wound. For each level, the width was 1.5 m, and 500 m was wound at 30 m / min. The film thickness of the obtained film was 100 μm.

  The physical properties of the unstretched cellulose ester film thus obtained were measured by the methods described above and below and are shown in Table 1. The sample containing the fluorosurfactant of the present invention has an excellent surface shape, small Re, Rth and thickness unevenness, small dependency of optical characteristics on humidity change, and all points of scratch resistance and dust. It was excellent. Each evaluation was performed according to the following.

(Daisy)
The evaluation of the die stripe was carried out in accordance with the following by visual observation under a reflected light source.
A: Dice lines were not seen.
B: Dice lines were slightly seen.
C: Dice lines were clearly recognized.
D: Dice lines were remarkably generated on the entire surface.

(Scratch resistance of film)
The sample was cut to 5 cm x 30 cm (longitudinal direction was the casting direction), conditioned for 2 hours at 25 ° C and 60% relative humidity, then a diamond needle with a tip of 0.025 mmR was installed vertically and a continuous load was applied. Scratching at a speed of 60 cm / min. The scratched sample was subjected to transmitted light and the load (g) at which scratches began to appear was evaluated as scratch resistance. The larger it is, the better the scratch resistance.

(With trash)
A sample of 20 cm × 20 cm was prepared and conditioned for 3 days in an environment of 25 ° C./25% relative humidity. A 1 kg weight was applied to a nylon cloth (5 cm × 5 cm) as a whole on the surface of the conditioned sample to which conductivity was imparted, and the sample surface (10 cm × 5 cm) was rubbed 10 times to impart an electrostatic charge. 5 seconds later, a surface rubbed at a distance of 1 cm is placed on a pre-collected tobacco ash after 5 seconds, and the attached state of the tobacco ash is visually confirmed, and the following four stages A to D are performed. evaluated. It shows that the antistatic property is excellent in the order of A, B, C, and D.
A: Adherence of tobacco was not particularly recognized.
B: Faint tobacco was observed.
C: A considerable amount of tobacco was observed.
D: Significant adhesion of tobacco was observed.

That is, it can be seen that in the cellulose ester film samples 1-3 to 1-8 of the present invention, the die lines are greatly improved. Accordingly, Re unevenness, Rth unevenness and thickness unevenness were very small and excellent. It was also confirmed that the humidity dependence of Re and Rth was small and excellent. This is excellent in all respects such as scratch resistance and dust, and this is an unexpected and excellent effect by using the fluorine-based surfactant of the present invention. In contrast, Comparative Sample 1-1 that does not contain the fluorosurfactant of the present invention, Comparative Sample 1-2 that contains a small amount of fluorosurfactant, and Comparative Sample 1 that uses another material as a release agent. -10 to Comparative Sample 1-15 had poor die streaking, poor Re unevenness, Rth unevenness, and uneven thickness, and also had insufficient scratch resistance and dust. Further, Comparative Sample 1-9 containing the fluorosurfactant of the present invention but having too much content was problematic because the film film was whitened and white turbidity was observed. From the above, it was possible to produce an excellent cellulose ester film by including the fluorosurfactant of the present invention in the cellulose ester of the present invention.
In addition, the manufacturing method in the melt film forming of the present invention does not require measures for the fire risk and material safety of the organic solvent, compared with the conventional method of dissolving in an organic solvent and forming a solution film, It is excellent in that there is no need to carry out recovery.

In Samples 1-3 to 1-8 of the present invention, the amount of residual acetic acid is less than 0.01% by mass, the Ca content is less than 0.05% by mass, and the Mg content is less than 0.01% by mass. Met. In addition, the longitudinal and transverse average heat shrinkage (80 ° C./relative humidity 90% / 48 hours) of the film was −0.1%, and a film that hardly caused heat shrinkage was obtained.
Here, as a representative film sample of the present invention, Sample 1-3 has a haze of 0.2%, a transparency (transparency) of 93.3%, a slope width of 19.4 nm, a limit wavelength of 393.3 nm, and an absorption edge. The absorption at 375.5 nm and 380 nm is 1.7%, Re is 1.1 nm, Rth is 140 nm, the axis deviation (molecular alignment axis) is 0.2 °, the molecular alignment axis is 0.3 °, The elastic modulus is 3.23 GPa in the longitudinal direction and 3.06 GPa in the width direction, the tensile strength is 126 MPa in the longitudinal direction and 122 MPa in the width direction, and the elongation is 67% in the longitudinal direction and 61% in the width direction. Friction coefficient) was 0.53, the kishimi value (dynamic friction coefficient) was 0.42, the alkali hydrolyzability was A, the curl value was -0.2 at 25% relative humidity, and 1.3 at wet.

  The moisture content was 1.9% by mass, and the thermal shrinkage was −0.12% in the longitudinal direction and −0.09% in the width direction. The foreign matter had a lint of less than 5 pieces / m. Further, the bright spots were 0.02 mm to 0.05 mm less than 10/3 m, 0.05 to 0.1 mm less than 4/3 m, and 0.1 mm or more. These had excellent properties for optical applications. Moreover, adhesion after application was not observed (◯), and the moisture permeability was good (◯). Other samples of the present invention also showed characteristic values almost equivalent to those of Sample 1-3.

(Example 2)
Cellulose ester A in Sample 1-5 of the present invention of Example 1 was changed to cellulose ester B (acetyl substitution degree 0.65, butyryl substitution degree 2.30, total substitution degree 2.95, viscosity average polymerization degree 180, water content 0 Sample 1-5 of Example 1 except that the viscosity is 80 mPa · s, 2% by mass, 6% by mass in dichloromethane solution, and the average particle size is 1.5 mm and the standard deviation is 0.5 mm. Sample 2-1 of the present invention was produced in exactly the same manner as in Example 1. Further, cellulose ester A was converted to cellulose ester C (acetyl substitution degree 1.30, propionyl substitution degree 1.60, total substitution degree 2.90, viscosity average polymerization degree 360, water content 0.2 mass%, 6 mass in dichloromethane solution. Sample 2 of the present invention in exactly the same manner as Sample 1-5 of Example 1, except that the viscosity is 265 mPa · s, the average particle size is 1.4 mm, and the standard deviation is 0.5 mm. -2 was produced. Even with the cellulose ester B having a slightly low degree of polymerization of the cellulose ester of the present invention, the die streak was good and the Re unevenness, Rth unevenness and thickness unevenness were very small and excellent. Further, the sample 2-2 of the present invention using the cellulose ester C whose cellulose ester is cellulose acetylpropionate and has a high degree of polymerization is also excellent with very small die lines, Re unevenness, Rth unevenness, and uneven thickness. It was a thing. Furthermore, it was excellent in all points including scratch resistance and dust. From the above, it was confirmed that the permissible range of the degree of polymerization of the cellulose ester was wide in the present invention.

(Example 3)
In Example 1, sample 1-5 of the present invention was subjected to alkali saponification treatment under the following conditions. The film was immersed in a solution of 3 mol / L NaOH aqueous solution at 60 ° C. for 2 minutes, washed with water at 25 ° C. for 30 seconds, and then washed with 0.5 mol / L sulfuric acid aqueous solution (25 ° C.). Treated for a minute and washed again with water at 25 ° C. When the contact angle (vs. pure water) of the obtained alkali saponified film was measured, it was 32 ° and the wettability was good. The contact angle before the alkali saponification treatment is 61 °, and it can be seen that the sample of the present invention has excellent surface treatment properties. A 10 ml / m ² aqueous solution of PVA / glutaraldehyde (5% by mass / 0.2% by mass)) was applied onto these films, and a commercially available polarizing film HLC2-5618 (manufactured by Sanritz) was attached to the film at 70 ° C. For 1 hour and left at 30 ° C. for 6 days. The obtained polarizing film with a cellulose ester film was provided with 11 grid cuts at an angle of 45 ° and a depth of 200 μm at a right angle to the cellulose ester film side by a cutter knife. Nichiban cello tape No. 405 (cello tape: registered trademark) and Nitto tape (PET tape) were firmly attached to the entire surface of the scar and left for 30 minutes, and the edges were peeled off at right angles. As a result, all the saponified cellulose ester films were peeled off from the unsaponified cellulose ester film, but the polarizing film provided with the saponified cellulose ester film was peeled off from any tape. But it was not seen at all. From the above, it can be seen that the cellulose ester film of the present invention has excellent polarizing film properties.

(Example 3-2)
Sample 1-5 of the present invention obtained in Example 1 was carried out at a stretching temperature of 158 ° C., stretching ratios of 109% in the longitudinal direction (MD direction) and 145% in the lateral direction (TD direction). 1 (stretched film) was obtained. The stretching speed was 1 m / min. When the characteristic was evaluated in Table 1 about the obtained stretched film sample 3-1, it turns out that die lines are further improved by extending | stretching. In addition, Re unevenness, Rth unevenness, and unevenness in thickness were further reduced and excellent. It was also confirmed that the humidity dependence of Re and Rth was small and excellent. Re was 62 nm and Rth was 203 nm.

Example 4
Next, examples in which the cellulose ester film is applied to a polarizing plate and the like will be described.
(4-1) Preparation of polarizing plate (1) Saponification of cellulose ester film Unstretched cellulose triacetate film 1-5 and stretched cellulose ester film 3-1 were saponified by the following method. That is, 20 parts by mass of water was added to 80 parts by mass of isopropanol, and KOH was dissolved to 1.5 mol / L, and then the temperature was adjusted to 60 ° C. was used as a saponification solution. And 10 g / m < ² > was apply | coated on the 60 degreeC cellulose-ester film, and it saponified for 1 minute. Thereafter, hot water at 50 ° C. was sprayed at 10 liter / m ² · min for 1 minute to perform washing. Thereafter, drying air of 110 ° C. was sent at a wind speed of 15 m / sec and dried for 5 minutes. These saponifications were performed on a roll film at a speed of 45 m / min.

(2) Creation of Polarizing Layer According to Example 1 of JP-A-2001-141926, a peripheral speed difference was given between two pairs of nip rolls, and the film was stretched in the longitudinal direction to prepare a polarizing layer having a thickness of 20 μm.

(3) Bonding The polarizing layer obtained in this way, the saponified unstretched cellulose triacetate film 1-10, and the stretched cellulose ester film 3-1, sandwiching the polarizing layer between them, and then PVA (Puraray Co., Ltd. PVA-117H) 3% aqueous solution was used as an adhesive, and the polarizing axis and the cellulose ester film were laminated so that the longitudinal direction was 90 degrees. Among these, after attaching an unstretched and stretched cellulose ester film to a 20-inch VA liquid crystal display device described in FIGS. 2 to 9 of JP-A-2000-154261 at 25 ° C. and a relative humidity of 60%, Is brought into 25 ° C and 10% relative humidity, and the color change is visually evaluated on a 10-point scale (the larger the change, the greater the change), and the area where display unevenness occurs is visually evaluated. When the ratio (%) in which the occurrence of odor occurred was determined, the change in color tone of the cellulose ester film of the present invention was 1, which was very excellent.
Further, according to Example 1 of JP-A-2002-86554, the cellulose ester film of the present invention is similarly used for a polarizing plate stretched using a tenter so that the stretching axis is at an angle of 45 ° with respect to the absorption axis. Although it was fabricated, good results were obtained as described above.

(4-2) Preparation of optical compensation film Instead of the cellulose acetate film coated with the liquid crystal layer of Example 1 of JP-A-11-316378, the saponified stretched cellulose ester film 3-1 of the present invention is used. And after attaching this to the bend alignment liquid crystal cell described in Example 9 of JP-A-2002-62431 at 25 ° C. and 60% relative humidity, it is brought into 25 ° C. and 10% relative humidity. The change in contrast was visually evaluated, and the color change was evaluated on a 10-point scale (the larger the change, the greater the change), and a mark 2 was obtained. Good performance was obtained by carrying out the present invention.

(4-3) Preparation of low-reflection film The stretched and unstretched cellulose ester film sample 1-8 of the present invention was applied to the cellulose ester film of the present invention in accordance with Example 47 of the Japan Institute of Invention and Technology (Publication No. 2001-1745). When a low-reflection film was produced using it, good optical performance was obtained.

(Example 5)
The stretched film 3-1 of the present invention produced in Example 3 was used in place of the cellulose triacetate film sample 1301 in Example 13 described in JP-A-2002-265636. A bend-aligned liquid crystal cell was prepared in the same manner as in Example 13 described in JP-A-2002-265636 by preparing an optically anisotropic layer and a polarizing plate sample. The obtained liquid crystal cell had excellent viewing angle characteristics.

(Example 6)
Using the cellulose ester film sample 1-8 of the present invention produced in Example 1, the produced film had Re of 3 nm and Rth of 81 nm. This film was used in place of the cellulose triacetate film sample 1401 in Example 14 described in JP-A No. 2002-265636. Then, a TN type liquid crystal cell was produced in the same manner as in Example 14 described in JP-A No. 2002-265636 by producing an optically anisotropic layer and a polarizing plate sample. The obtained liquid crystal cell had excellent viewing angle characteristics.

(Example 7)
(1) Mounting on VA panel The polarizing plate produced in Example 4 of the present invention is a polarizing plate on the backlight side so that the polarizing plate on the viewing side is 26 ″ wide and the absorption axis of the polarizer is long. The plate was punched into a rectangle so that the absorption axis of the polarizer was short. VA mode liquid crystal TV (manufactured by Sony Corporation, KDL-L26RX2), peel off the front and back polarizing plates and retardation plate, and paste the polarizing plate produced in Example 4 of the present invention on the front and back sides in combination, A liquid crystal display device was produced. After attaching the polarizing plate, it was held at 50 ° C. and 5 kg / cm ² for 20 minutes for adhesion. In this case, the absorption axis of the polarizing plate on the viewing side is in the horizontal direction of the panel, the absorption axis of the polarizing plate on the backlight side is in the vertical direction of the panel, and the adhesive material surface is on the liquid crystal cell side. After removing the protective film, the viewing angle (range of contrast ratio of 10 or more) was calculated from the luminance measurement of black display and white display using a measuring device (EZ-Contrast 160D manufactured by ELDIM). When any polarizing plate was used, good viewing angle characteristics with polar angles of 80 ° or more were obtained in all directions.

Furthermore, light leakage and polarizing plate peeling tests were carried out by an endurance test, and it was confirmed that there was no problem. The durability test conditions are as follows.
1) Hold in an environment of 60 ° C and 90% relative humidity for 200 hours, take out in an environment of 25 ° C and 60% relative humidity, and display the liquid crystal display device in black 24 hours later, light leakage strength and peeling of the polarizing plate from the liquid crystal panel The presence or absence of was evaluated.
2) Hold at 80 ° C. dry for 200 hours, take out to 25 ° C. and 60% relative humidity environment, display the liquid crystal display device black one hour later, and evaluate the light leakage strength and whether the polarizing plate is peeled off from the liquid crystal panel did.

(Example 8)
The sample of the present invention is prepared on an optical anisotropic film exhibiting desired optical characteristics, the following different liquid crystal mode commercial monitors or television retardation films are peeled off, and the retardation film of the present invention is applied thereto. When viewing angle characteristics were examined, excellent wide viewing angle characteristics and colors were obtained, and it was confirmed that the cellulose ester of the present invention was useful.

(TN mode)
Both the viewing-side polarizing plate and the backlight-side polarizing plate were punched into a rectangular shape so that the absorption axis was 45 ° long with respect to the long side of the polarizing plate after punching at a size of 17 ″. A polarizing plate made of the cellulose ester of the present invention is bonded to the front and back sides of the TN mode liquid crystal monitor (manufactured by Samsung, SyncMaster 172X). did. After attaching the polarizing plate, it was held at 50 ° C. and 5 kg / cm ² for 20 minutes for adhesion. At this time, the optically anisotropic layer of the polarizing plate faced the cell substrate, and the rubbing direction of the liquid crystal cell and the rubbing direction of the optically anisotropic layer facing the liquid crystal cell were arranged to be antiparallel.

(IPS panel)
The polarizing plate of the present invention is such that the viewing side polarizing plate is 32 ″ wide and the absorption axis of the polarizer is long, and the backlight side polarizing plate is such that the absorption axis of the polarizer is short. Punched into a rectangle. The front and back polarizing plates and retardation plates of the IPS mode liquid crystal TV (manufactured by Hitachi, Ltd., W32-L5000) are peeled off, and the polarizing plates made from the cellulose ester of the present invention are attached to the front and back sides in combination. A liquid crystal display device was produced. After attaching the polarizing plate, it was held at 50 ° C. and 5 kg / cm ² for 20 minutes for adhesion. In this case, the absorption axis of the polarizing plate on the viewing side is in the horizontal direction of the panel, the absorption axis of the polarizing plate on the backlight side is in the vertical direction of the panel, and the adhesive layer surface is on the liquid crystal cell side.

  According to the production method of the present invention, it is possible to provide a cellulose ester film that greatly reduces die streaks, thickness unevenness and optical property unevenness, and has improved scratch resistance and dust prevention. If the cellulose ester film of the present invention is incorporated in an optical display device such as a liquid crystal display device, it is possible to greatly suppress changes in visibility due to display unevenness and humidity, which have been problems in the past. Therefore, the cellulose ester film of the present invention has high industrial applicability.

Claims (11)

Any of the following general formulas (2A), (2B), (2C) and (2D) with respect to the cellulose ester satisfying the following formulas (S-1) to (S-3) and the solid content of the cellulose ester The manufacturing method of the cellulose-ester film characterized by including the process of melt-casting the mixture with 0.01-5 mass% of fluorine-type surfactant represented by these.
Formula (S-1) 2.5 <= A + B <= 3.0
Formula (S-2) 0 ≦ A ≦ 2.2
Formula (S-3) 0.8 ≦ B ≦ 3.0
(In the formula, A represents the substitution degree of the acetyl group to the hydroxyl group of cellulose, and B represents the substitution degree of the acyl group having 3 to 22 carbon atoms to the hydroxyl group of cellulose.)
General formula (2A)

(Wherein R ^A1 and R ^A2 each represent a substituted or unsubstituted alkyl group, but at least one of R ^A1 and R ^A2 represents an alkyl group substituted with a fluorine atom. R ^A3 , R ^A4 and R ^A5 independently represents a hydrogen atom or a substituent, L ^A1 , L ^A2 and L ^A3 each independently represent a single bond or a divalent linking group, X ⁺ represents a cationic substituent, Y ⁻ represents (This represents a counter anion, but Y ⁻ may not be present when the charge is 0 in the molecule. ^{M A} is 0 or 1.)
General formula (2B)

(In the formula, R ^B3 , R ^B4 and R ^B5 each independently represent a hydrogen atom or a substituent. A and B each independently represent a fluorine atom or a hydrogen atom. N ^B3 and n ^B4 each independently represents 4 to 4) And represents an integer of 8. L ^B1 and L ^B2 each independently represent a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkyleneoxy group, or a divalent linking group formed by a combination thereof. ^B represents 0 or 1. M represents a cation.)
General formula (2C)

(Wherein R ^C1 represents a substituted or unsubstituted alkyl group, R ^CF represents a perfluoroalkylene group, A represents a hydrogen atom or a fluorine atom, L ^C1 represents a substituted or unsubstituted alkylene group, substituted or Y ^C1 and Y ^C2 each represents an unsubstituted alkyleneoxy group or a divalent linking group formed by a combination thereof, one of which represents a hydrogen atom and the other represents —L ^C2 —SO ₃ M, where L ^C2 represents a single bond or a substituted or unsubstituted alkylene group, and M represents a cation.)

General formula (2D)
[Rf ^D- (L ^D ) _nD ] _mD -W
(In the formula, Rf ^D represents a perfluoroalkyl group, L ^D is an alkylene group, W is a group having an anionic group, a cationic group, a betaine group or a nonionic polar group necessary for imparting surface activity. N ^D represents 0 or 1, and m ^D represents any integer of 1 to 3.)   The method for producing a cellulose ester film according to claim 1, further comprising a step of stretching 1% to 500% in at least one direction after the melt film formation.   A cellulose ester film produced by the production method according to claim 1. Any of the following general formulas (2A), (2B), (2C) and (2D) with respect to the cellulose ester satisfying the following formulas (S-1) to (S-3) and the solid content of the cellulose ester A cellulose ester film comprising 0.01 to 5% by mass of a fluorine-based interface represented by:
Formula (S-1) 2.5 <= A + B <= 3.0
Formula (S-2) 0 ≦ A ≦ 2.2
Formula (S-3) 0.8 ≦ B ≦ 3.0
(In the formula, A represents the substitution degree of the acetyl group to the hydroxyl group of cellulose, and B represents the substitution degree of the acyl group having 3 to 22 carbon atoms to the hydroxyl group of cellulose.)
General formula (2A)

(Wherein R ^A1 and R ^A2 each independently represents a substituted or unsubstituted alkyl group, but at least one of R ^A1 and R ^A2 represents an alkyl group substituted with a fluorine atom. R ^A3 , R ^A4 And R ^A5 each independently represents a hydrogen atom or a substituent, L ^A1 , L ^A2 and L ^A3 each independently represent a single bond or a divalent linking group, and X ⁺ represents a cationic substituent. ^- represents a counter anion, when the intramolecular charge is 0 Y ^- good .m ^a if not 0 or 1).
General formula (2B)

(In the formula, R ^B3 , R ^B4 and R ^B5 each independently represent a hydrogen atom or a substituent. A and B each independently represent a fluorine atom or a hydrogen atom. N ^B3 and n ^B4 each independently represents 4 to 4) And represents an integer of 8. L ^B1 and L ^B2 each independently represent a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkyleneoxy group, or a divalent linking group formed by a combination thereof. ^B represents 0 or 1. M represents a cation.)
General formula (2C)

(Wherein R ^C1 represents a substituted or unsubstituted alkyl group, R ^CF represents a perfluoroalkylene group, A represents a hydrogen atom or a fluorine atom, L ^C1 represents a substituted or unsubstituted alkylene group, substituted or Y ^C1 and Y ^C2 each represents an unsubstituted alkyleneoxy group or a divalent linking group formed by a combination thereof, one of which represents a hydrogen atom and the other represents —L ^C2 —SO ₃ M, where L ^C2 represents a single bond or a substituted or unsubstituted alkylene group, and M represents a cation.)

General formula (2D)
[Rf ^D- (L ^D ) _nD ] _mD -W
(In the formula, Rf ^D represents a perfluoroalkyl group, L ^D is an alkylene group, W is a group having an anionic group, a cationic group, a betaine group or a nonionic polar group necessary for imparting surface activity. N ^D represents 0 or 1, and m ^D represents any integer of 1 to 3.)   The acyl group having 3 to 22 carbon atoms substituted on the hydroxyl group of cellulose is at least one kind of acyl group selected from the group consisting of propionyl group, butyryl group, pentanoyl group and hexanoyl group. The cellulose ester film according to claim 3 or 4.   6. The in-plane retardation (Re) is 0 ≦ Re ≦ 200 nm, and the thickness direction retardation (Rth) is −200 ≦ Rth ≦ 500 nm. The cellulose ester film as described.   The cellulose ester film according to any one of claims 3 to 6, wherein the thickness unevenness of the cellulose ester film is 0% to 2%.   The cellulose ester film according to any one of claims 3 to 7, wherein a contact angle of water on the film surface is 45 ° or less (25 ° C / 60% relative humidity).   The optical polarizing plate produced using the cellulose-ester film as described in any one of Claims 3-7.   The phase difference plate produced using the cellulose-ester film as described in any one of Claims 3-7.   The optical display apparatus produced using the cellulose-ester film as described in any one of Claims 3-7.