JP2015224256A - Method of producing cellulose derivative, method of producing substituted cellulose derivative, optical film, circular polarizing plate and organic electroluminescent display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing a substituted cellulose derivative by introducing a substituent into a cellulose derivative, and an optical film, a circular polarizing plate and an organic electroluminescent display device prepared using the compound.SOLUTION: In the presence of a compound represented by general formula (1), a compound represented by general formula (2) is hydrolyzed. In the general formula (1): (W)(Y), W represents an ion having an ion radius of 1.5-2.0 Å, Y represents a counterion, and m and n independently represent an integer of 1 or more.

Description

  The present invention relates to a method for producing a cellulose derivative, a method for producing a substituted cellulose derivative, an optical film, a circularly polarizing plate, and an organic electroluminescence display device.

  Cellulose is a polysaccharide abundant in nature, and cellulose derivatives are used in many fields. Among these, cellulose acetate is widely used as separation membranes such as reverse osmosis membranes, biodegradable plastics, paints such as lacquer, fibers and films. As a material that is kind to nature, it has recently attracted attention especially in environment-related fields.

In cellulose acetate, the functional group bonded to carbons at the 2, 3, 6 positions of the anhydroglucose unit is a hydroxy group or an acetyl group.
And the parameter which shows how many hydrogen groups are substituted by the acetyl group on the average among the hydroxyl groups couple | bonded with the carbon atom of the 2,3,6-position of an anhydroglucose unit is a substitution degree.

When adding value to cellulose acetate and using it for a new application, there are two methods of adding a low molecular weight compound as an additive or introducing a functional group directly into cellulose acetate.
In the former case, the low molecular weight compounds that are compatible with cellulose acetate are limited, and the characteristics of cellulose acetate itself, such as water absorption and low solubility in organic solvents, remain as problems. It is difficult to apply.
In the latter case, a new functional group is introduced into the hydroxy group in cellulose acetate. Specifically, a method for obtaining an aliphatic or aromatic acylated cellulose acetate by reacting cellulose acetate with an aliphatic or aromatic acid chloride or the like is known.
However, in this reaction, cellulose acetate with good solvent solubility has a limited degree of acetyl group substitution (cellulose acetate with a low degree of acetyl group substitution is difficult to dissolve in organic solvents). In addition to limiting the degree of substitution, it is very difficult to introduce the acyl group regioselectively and uniformly at the 2, 3, 6 positions. Depending on the position of substitution, the physical properties of the cellulose derivative produced and the properties of the optical film containing the cellulose derivative are greatly affected.

  For example, Patent Document 1 discloses an example in which an aliphatic or aromatic acyl group is substituted for a hydroxy group of cellulose acetate. However, the position of substitution in this cellulose mixed acid ester compound is not controlled, and vice versa. Advanced functions such as wavelength dispersion and environmental fluctuation resistance have not been developed.

Patent Documents 2 and 3 disclose films obtained by benzoylating cellulose acetate. However, in these Patent Documents 2 and 3, although cellulose anhydroglucose units having a high degree of substitution with the benzoyl group at the 6th position have been obtained, cellulose acetate having a benzoyl group selectively introduced at the 2nd and 3rd positions is obtained. Not.
Regarding the regioselective deacetylation of cellulose acetate at positions 2, 3, and 6, the report on the regioselectivity of deacetylation reaction using amine (Non-patent Document 1), tetrabutylammonium fluoride trihydrate Although there is a report on a selective deacetylation reaction at the 2nd and 3rd positions by a Japanese product (Non-Patent Document 2), an example using a metal salt as a base is not known.

Cellulose acetate is used, for example, as a polarizing plate protective film, and when the film is used under severe conditions of high temperature and high humidity, the degree of polarization of the polarizing plate may decrease due to its moisture permeability. There may be a case where a change in optical anisotropy occurs due to a change in size due to or a change in optical physical properties derived therefrom. In particular, when used as an optical film, the product performance is often adversely affected.
When cellulose acetate is used as a λ / 4 film having reverse wavelength dispersion, a substituent having UV absorption is introduced into cellulose acetate in order to improve reverse wavelength dispersion. If it is changed and introduced at the 6th position having high reactivity with the UV absorbing group, the desired reverse wavelength dispersibility cannot be obtained.

JP 2002-322201 A JP 2007-199392 A JP 2007-199391 A

Shibata, T. et al. Proc. Of 1st International Cellulose Conference, O3-01, Kyoto, Japan, 6-8 Nov. 2002. ) Biomacromolecules, 2013, 14, 1388-1394

  The present invention has been made in view of the above-described problems and circumstances, and its solution is to provide a method for producing a cellulose derivative that can cleave position-selective substituents of cellulose acetate and has good solvent solubility. It is to be. And it is providing the manufacturing method of the substituted cellulose derivative which introduce | transduced the substituent into this cellulose derivative. Furthermore, by using the substituted cellulose derivative, an optical film, a circularly polarizing plate, and an organic electroluminescence display device that exhibit excellent reverse wavelength dispersion and λ / 4 phase difference and have small dimensional fluctuation due to humidity and heat. Is to provide.

In order to solve the above problems, the present inventor is represented by the above general formula (2) in the presence of the compound having the structure represented by the above general formula (1) in the process of examining the cause of the above problems. By hydrolyzing a compound having a structure, a cellulose derivative having the structure represented by the general formula (3) is obtained, whereby regioselective cleavage of cellulose acetate is possible, and solvent solubility is achieved. Was found to be able to provide a method for producing a good cellulose derivative, leading to the present invention.
That is, the said subject which concerns on this invention is solved by the following means.
1. The structure represented by the following general formula (3) is obtained by hydrolyzing the compound having the structure represented by the following general formula (2) in the presence of the compound having the structure represented by the following general formula (1). A method for producing a cellulose derivative, which comprises obtaining a cellulose derivative having
General formula (1): (W) _m (Y) _n
[Wherein, W represents an ion having an ionic radius in the range of 1.5 to 2.0 Å. Y represents a counter ion. m and n each independently represent an integer of 1 or more. ]

［式中、Ｒ_２０、Ｒ_３０及びＲ_６０は、それぞれ、独立に水素原子、脂肪族基又は芳香族基を表す。Ｌ_２０、Ｌ_３０及びＬ_６０は、それぞれ、独立に単結合、−Ｏ−、−ＣＯ−又は−（Ｌｗ−Ｏ）ｑ−からなる群から選ばれる一種以上の基から形成される２価の連結基を表す。Ｌｗは、アルキレン基を表す。ｑは、０〜１０の整数を表す。ｐ０は、平均重合度を表し、１０〜２０００の整数を表す。］

[Wherein, R ₂₀ , R ₃₀ and R ₆₀ each independently represents a hydrogen atom, an aliphatic group or an aromatic group. L ₂₀ , L ₃₀ and L ₆₀ are each a divalent group formed from one or more groups independently selected from the group consisting of a single bond, —O—, —CO— or — (Lw—O) q—. Represents a linking group. Lw represents an alkylene group. q represents an integer of 0 to 10. p0 represents an average degree of polymerization and represents an integer of 10 to 2000. ]

［式中、Ｒ_２、Ｒ_３及びＲ_６は、それぞれ、独立に水素原子、脂肪族基又は芳香族基を表す。Ｌ_２、Ｌ_３及びＬ_６は、それぞれ、独立に単結合、−Ｏ−、−ＣＯ−又は−（Ｌｗ−Ｏ）ｑ−からなる群から選ばれる一種以上の基から形成される２価の連結基を表す。Ｌｗは、アルキレン基を表す。ｑは、０〜１０の整数を表す。ｐは、平均重合度を表し、１０〜２０００の整数を表す。
ただし、−Ｌ_２−Ｒ_２、−Ｌ_３−Ｒ_３及び−Ｌ_６−Ｒ_６による置換度は、下記式（ａ）及び下記式（ｂ）を満たす。
式（ａ）：（−Ｌ_２−Ｒ_２による置換度）＜（−Ｌ_６−Ｒ_６による置換度）
式（ｂ）：（−Ｌ_３−Ｒ_３による置換度）＜（−Ｌ_６−Ｒ_６による置換度）
−Ｌ_２−Ｒ_２、−Ｌ_３−Ｒ_３及び−Ｌ_６−Ｒ_６による置換度とは、無水グルコースユニットに対して、２位、３位及び６位の三つの炭素原子に結合しているヒドロキシ基のうち、平均して何個が置換基で水素原子が置換されているかを表す数値である。］

[Wherein R ₂ , R ₃ and R ₆ each independently represent a hydrogen atom, an aliphatic group or an aromatic group. L ₂ , L ₃ and L ₆ are each independently a divalent group formed from one or more groups selected from the group consisting of a single bond, —O—, —CO— or — (Lw—O) q—. Represents a linking group. Lw represents an alkylene group. q represents an integer of 0 to 10. p represents an average degree of polymerization and represents an integer of 10 to 2000.
_However, -L ₂ -R 2, degree of substitution with _-L 3 -R ₃ and _-L 6 -R ₆ satisfies the following formula (a) and the following formula (b).
Formula (a): (Substitution degree by -L ₂ -R ₂ ) <(Substitution degree by -L ₆ -R ₆ )
Formula (b): (Substitution degree by -L ₃ -R ₃ ) <(Substitution degree by -L ₆ -R ₆ )
The degree of substitution with -L ₂ -R ₂ , -L ₃ -R ₃ and -L ₆ -R ₆ refers to the bonding to three carbon atoms at the 2nd, 3rd and 6th positions relative to the anhydroglucose unit. It is a numerical value showing how many of the hydroxy groups on average are substituted with hydrogen atoms. ]

  2. In the said General formula (1), the ion represented by W is a cesium ion, The manufacturing method of the cellulose derivative of Claim 1 characterized by the above-mentioned.

  3. The method for producing a cellulose derivative according to item 1 or 2, wherein the compound having a structure represented by the general formula (1) is cesium carbonate.

4). In the general formula (2), R ₂₀ , R ₃₀ and R ₆₀ are each a hydrogen atom or a methyl group,
The cellulose derivative according to any one of items 1 to 3, wherein in the general formula (3), R ₂ , R _3, and R ₆ are each a hydrogen atom or a methyl group. Manufacturing method.

5. By reacting a cellulose derivative having a structure represented by the general formula (3) with a compound having a structure represented by the following general formula (4a), general formula (4b) or general formula (4c), The manufacturing method of the substituted cellulose derivative characterized by obtaining the substituted cellulose derivative which has a structure represented by following General formula (5).
General formula (4a): Rv- (L) q-X
[Wherein Rv represents an aliphatic group or an aromatic group. L represents a carbonyl group. q represents 0 or 1; X represents a halogen atom. ]
Formula (4b): (Rv-L) ₂ O
[Wherein Rv represents an aliphatic group or an aromatic group. L represents a carbonyl group. ]
General formula (4c): Rv-N = C = Z
[Wherein Rv represents an aliphatic group or an aromatic group. Z represents an oxygen atom or a sulfur atom. ]

［式中、Ｒ_２１、Ｒ_３１及びＲ_６１は、それぞれ、独立に水素原子、脂肪族基又は芳香族基を表す。ただし、Ｒ_２１、Ｒ_３１及びＲ_６１のうち少なくとも一つは、前記一般式（４ａ）、前記一般式（４ｂ）又は前記一般式（４ｃ）で表される構造を有する化合物に由来するＲｖである。Ｌ_２１、Ｌ_３１及びＬ_６１は、それぞれ、独立に、単結合、−Ｏ−、−ＣＯ−、−ＮＨＣＯ又は−（Ｌｗ−Ｏ）ｑ−からなる群から選ばれる一種以上の基から形成される２価の連結基を表す。Ｌｗは、アルキレン基を表す。ｑは、０〜１０の整数を表す。ｐ１は、平均重合度を表し、１０〜２０００の整数を表す。
なお、Ｒ_２１、Ｒ_３１及びＲ_６１のうち少なくとも一つが、Ｒｖであるときの、−Ｌ_２１−Ｒｖ、−Ｌ_３１−Ｒｖ及び−Ｌ_６１−Ｒｖによる置換度は、下記式（ｃ）及び下記式（ｄ）を満たす。
式（ｃ）：（−Ｌ_６１−Ｒｖによる置換度）＜（−Ｌ_２１−Ｒｖによる置換度）
式（ｄ）：（−Ｌ_６１−Ｒｖによる置換度）＜（−Ｌ_３１−Ｒｖによる置換度）
−Ｌ_２１−Ｒｖ、−Ｌ_３１−Ｒｖ及び−Ｌ_６１−Ｒｖによる置換度とは、無水グルコースユニットに対して、２位、３位及び６位の三つの炭素原子に結合しているヒドロキシ基のうち、平均して何個が置換基で水素原子が置換されているかを表す数値である。］

[Wherein, R ₂₁ , R ₃₁ and R ₆₁ each independently represents a hydrogen atom, an aliphatic group or an aromatic group. However, at least one of R ₂₁ , R ₃₁ and R ₆₁ is Rv derived from a compound having a structure represented by the general formula (4a), the general formula (4b) or the general formula (4c). is there. L ₂₁ , L ₃₁ and L ₆₁ are each independently formed from one or more groups selected from the group consisting of a single bond, —O—, —CO—, —NHCO or — (Lw—O) q—. Represents a divalent linking group. Lw represents an alkylene group. q represents an integer of 0 to 10. p1 represents an average degree of polymerization and represents an integer of 10 to 2000.
In addition, when at least one of R ₂₁ , R ₃₁ and R ₆₁ is Rv, the degree of substitution with -L ₂₁ -Rv, -L ₃₁ -Rv and -L ₆₁ -Rv is represented by the following formula (c) and The following formula (d) is satisfied.
Formula (c): (Substitution degree by -L ₆₁ -Rv) <(Substitution degree by -L ₂₁ -Rv)
Formula _{(d): (-} L 61 degree of substitution -Rv) _<(- degree of substitution by L 31 -Rv)
-L _{21 -Rv,} and the degree of substitution by _-L 31 -Rv and _-L 61 -Rv, against anhydroglucose unit, 2-position, 3-position and 6-position three hydroxy groups attached to a carbon atom Among these, on average, this is a numerical value representing how many hydrogen atoms are substituted with substituents. ]

  6). 6. The method for producing a substituted cellulose derivative according to item 5, wherein Rv is an aromatic group in the compound having a structure represented by the general formula (4a) to the general formula (4c).

  7). An optical film comprising a substituted cellulose derivative produced by the method for producing a substituted cellulose derivative according to item 5 or 6.

  8). 8. The optical film according to item 7, which is a long film and has a slow axis in a range of 40 to 50 ° with respect to the longitudinal direction.

  9. A circularly polarizing plate, wherein the optical film according to item 7 or item 8 and a polarizer are bonded.

  10. An organic electroluminescence display device comprising the circularly polarizing plate according to item 9.

By the above-mentioned means of the present invention, the substitution position and the substitution degree can be controlled, and a cellulose derivative having good solvent solubility can be produced. Moreover, the manufacturing method of the substituted cellulose derivative which introduce | transduced the substituent into the said cellulose derivative can be provided.
Further, the optical film containing the substituted cellulose derivative can substantially give a phase difference of λ / 4 to light in a wide band in visible light, has excellent wavelength dispersion, Changes in optical performance (color performance, reflection characteristics) with respect to environmental changes such as heat are suppressed, and it can also have a function as a polarizing plate protective film.
Moreover, the organic electroluminescent display apparatus which comprised the circularly-polarizing plate which comprised the said optical film, and the said circularly-polarizing plate as an antireflection member can be provided.

The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
When an ion (W) having an ionic radius of 1.5Å or more is present in the system, the oxygen atom of the carbonyl group of the acyl group at the 2nd and 3rd positions in the cellulose derivative is coordinated to the ion (W), and the intermediate shown below The body is stabilized.

Then, the electrophilicity of the carbonyl carbon at the 2 and 3 positions is increased, and the hydrolysis reaction is likely to occur. As a result, it is presumed that the acyl group at the 2 and 3 positions is selectively cleaved.
Furthermore, when a substituent is introduced as a new modifying group for the cellulose derivative in which either of the acyl groups at positions 2 and 3 is cleaved, the 2nd or 3rd position in which an acyl group that is not cleaved remains. Because of the substitution at the position, the new substituent is sterically hindered by the adjacent acyl group (see below. The following shows the case where the acyl group at the 2-position is cleaved). As a result, for example, when a substituent having UV absorption is introduced, the substituent is immobilized in a direction orthogonal to the main chain direction, so that an effect of increasing the expression of reverse wavelength dispersion can be obtained.

  Cellulose ester film is known to have a phase difference that varies depending on humidity. As a cause of this, water molecules coordinate to acyl groups, and the birefringence of acyl groups changes to cause the phase difference to vary. Conceivable. On the other hand, as described above, if the acyl groups at the 2- and 3-positions are sterically immobilized, the water molecule becomes difficult to coordinate, or even if the water molecule is coordinated, the acyl group Therefore, it is presumed that the change in birefringence is suppressed, and as a result, the phase difference fluctuation can be suppressed.

Schematic diagram explaining shrinkage ratio in oblique stretching of optical film Schematic which showed an example of the rail pattern of the diagonal stretcher applicable to the manufacturing method of the optical film of this invention Schematic which shows an example (example which extends | stretches diagonally after extending | stretching from a long film original fabric roll) which concerns on embodiment of this invention. Schematic which shows an example (example which extends continuously diagonally, without winding up a long film original fabric) concerning the manufacturing method which concerns on embodiment of this invention Schematic sectional view showing an example of the configuration of the organic electroluminescence display device of the present invention

In the method for producing a cellulose derivative of the present invention, the compound having the structure represented by the general formula (2) is hydrolyzed in the presence of the compound having the structure represented by the general formula (1). A cellulose derivative having a structure represented by the general formula (3) is obtained. This feature is a technical feature common to the inventions according to claims 1 to 10.
As an embodiment of the present invention, it is preferable that the ion represented by W in the general formula (1) is a cesium ion from the viewpoint of manifesting the effect of the present invention. When the ion represented by W is a cesium ion, a stable intermediate is formed when the carbonyl group of the acyl group at the 2- and 3-positions of the cellulose derivative having the structure represented by the general formula (2) is coordinated. Can be formed. The electrophilicity of the carbonyl carbon at the 2 and 3 positions is increased, and the hydrolysis reaction is likely to occur. As a result, the acyl group at the 2 and 3 positions is selectively cleaved.

  Moreover, it is preferable that the compound having the structure represented by the general formula (1) is cesium carbonate because it does not cause a side reaction, but the acyl group cleavage reaction has a well-balanced basicity.

In the general formula (2), R ₂₀ , R ₃₀ and R ₆₀ are each a hydrogen atom or a methyl group. In the general formula (3), R ₂ , R ₃ and R ₆ are each a hydrogen atom. Or it is preferable that it is a methyl group at the point which raises an orientation degree, when making it orientate as a film.

  The method for producing a substituted cellulose derivative of the present invention is represented by the cellulose derivative having the structure represented by the general formula (3) and the general formula (4a), the general formula (4b), or the general formula (4c). By reacting with a compound having a structure, it is preferable to obtain a substituted cellulose derivative having a structure represented by the general formula (5) from the viewpoint of improving water resistance and improving solubility in an organic solvent.

  Moreover, in the compound having the structure represented by the general formula (4a) to the general formula (4c), it is used as an optical film at the same time that Rv is an aromatic group and water resistance and solubility are most improved. It is sometimes preferable in that the reverse wavelength dispersion can be improved.

Moreover, the substituted cellulose derivative manufactured by the manufacturing method of the substituted cellulose derivative of this invention can be used suitably for an optical film. The optical film containing the substituted cellulose derivative can substantially give a phase difference of λ / 4 to light in a wide band in visible light, has excellent wavelength dispersion, and further, moisture, heat, etc. Changes in optical performance (color performance, reflection characteristics) with respect to environmental fluctuations are suppressed, and it can also have a function as a polarizing plate protective film.
The optical film of the present invention is a long film, and preferably has a slow axis in the range of 40 to 50 ° with respect to the longitudinal direction.

Moreover, the optical film of this invention can be used suitably for a circularly-polarizing plate.
Moreover, the circularly-polarizing plate of this invention can be used suitably for an organic electroluminescent display apparatus.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

  Hereinafter, the manufacturing method of the cellulose derivative of this invention, the manufacturing method of a substituted cellulose derivative, an optical film, a circularly-polarizing plate, and the detail of an organic electroluminescent display apparatus are demonstrated.

[Method for producing cellulose derivative]
The method for producing a cellulose derivative of the present invention hydrolyzes a compound having a structure represented by the following general formula (2) in the presence of a compound having a structure represented by the following general formula (1) (in the presence of a base). Thus, a cellulose derivative having a structure represented by the following general formula (3) is obtained.

<Compound having structure represented by general formula (1)>
General formula (1): (W) _m (Y) _n
In the general formula (1), W represents an ion having an ion radius in the range of 1.5 to 2.0 kg.
Examples of the ion represented by W include cesium ion, tetraphenylborate ion, tetraphenylphosphonium ion, tetraphenylarsonium ion, and ethyl violet.

In the general formula (1), Y represents a counter ion.
m and n each independently represent an integer of 1 or more.

Specific examples of the compound (base) having the structure represented by the general formula (1) include cesium carbonate, cesium fluoride, sodium tetraphenylborate, potassium tetraphenylborate, tetraphenylphosphonium bromide, tetraphenylphosphonium chloride. And tetraphenylarsonium chloride.
Preferred are cesium carbonate, cesium fluoride, sodium tetraphenylborate, potassium tetraphenylborate, and tetraphenylphosphonium bromide.

In the regioselective acyl group cleavage reaction of the present invention, particularly when W is a cesium ion,
(1) A stable intermediate can be formed when the carbonyl group of the 2,3-position acyl group of the cellulose derivative having a large ionic radius of the cesium cation and having the structure represented by the general formula (2) is coordinated.
(2) Although cesium carbonate and cesium fluoride do not cause side reactions, the acyl group cleavage reaction proceeds with a good balance.
(3) Both cesium carbonate and cesium fluoride have high solubility in organic solvents, and the reaction system is uniform because it dissolves in the solvent that dissolves the cellulose derivative having the structure represented by the general formula (2). The speed is fast.
Therefore, it is the most preferable ion.

Moreover, since the treatment after the reaction is easy, there is no problem in mass production.
Furthermore, when another reaction such as a benzoylation reaction is performed by running following the acyl group cleavage reaction, side reactions are unlikely to occur and the base is not inconvenient.

<Compound having a structure represented by the general formula (2)>

In the general formula (2), R ₂₀ , R ₃₀ and R ₆₀ each independently represent a hydrogen atom, an aliphatic group or an aromatic group.
Examples of the aliphatic group represented by R ₂₀ , R ₃₀ and R ₆₀ include an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group). , Dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (eg, vinyl group, allyl group, etc.), alkynyl group (eg, ethynyl group, Propargyl group, etc.).
The aliphatic group represented by R ₂₀ , R ₃₀ and R ₆₀ is preferably a methyl group, an ethyl group or a propyl group.

Examples of the aromatic group represented by R ₂₀ , R ₃₀ and R ₆₀ include aromatic hydrocarbon ring groups (for example, phenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, Acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.), aromatic heterocyclic group (for example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group) Group, triazolyl group (for example, 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, Isothiazolyl, furazanyl, thienyl, quinolyl, benzofuryl, dibenzo Nzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom) Quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, and the like.
The aromatic group represented by R ₂₀ , R ₃₀ and R ₆₀ is preferably a phenyl group or a thienyl group.

In the general formula (2), L ₂₀ , L ₃₀ and L ₆₀ are each independently one or more groups selected from the group consisting of a single bond, —O—, —CO— or — (Lw—O) q—. Represents a divalent linking group formed from
L ₂₀ , L ₃₀ and L ₆₀ are preferably —O— and —CO—.

In the general formula (2), Lw represents an alkylene group. q represents an integer of 0 to 10.
p0 represents an average degree of polymerization and represents an integer of 10 to 2000.

<Cellulose derivative having a structure represented by the general formula (3)>

In the general formula (3), R ₂ , R ₃ and R ₆ each independently represent a hydrogen atom, an aliphatic group or an aromatic group.
The aliphatic group represented by R ₂ , R ₃ and R ₆ is preferably a methyl group or a propyl group.

In the general formula (3), L ₂ , L ₃ and L ₆ are each independently one or more groups selected from the group consisting of a single bond, —O—, —CO— or — (Lw—O) q—. Represents a divalent linking group formed from
L ₂ , L ₃ and L ₆ are preferably —O— and —CO—.

In the general formula (3), Lw represents an alkylene group. q represents an integer of 0 to 10.
p represents an average degree of polymerization and represents an integer of 10 to 2000.

_However, -L ₂ -R 2, degree of substitution with _-L 3 -R ₃ and _-L 6 -R ₆ satisfies the following formula (a) and the following formula (b).
Formula (a): (Substitution degree by -L ₂ -R ₂ ) <(Substitution degree by -L ₆ -R ₆ )
Formula (b): (Substitution degree by -L ₃ -R ₃ ) <(Substitution degree by -L ₆ -R ₆ )
The degree of substitution with -L ₂ -R ₂ , -L ₃ -R ₃ and -L ₆ -R ₆ refers to the bonding to three carbon atoms at the 2nd, 3rd and 6th positions relative to the anhydroglucose unit. It is a numerical value showing how many of the hydroxy groups on average are substituted with hydrogen atoms.

In the present invention, the degree of substitution of anhydroglucose units with -L ₂ -R ₂ , -L ₃ -R ₃ and -L ₆ -R ₆ is determined according to Cellulose Communication ₆ , 73-79 (1999) and Chalality 12 (9). , 670-674, and can be determined by ¹ H-NMR or ¹³ C-NMR.

  In addition, the cellulose derivative having the structure represented by the general formula (3) includes a case where a hydroxy group is bonded to all three carbon atoms at 2, 3, 6 positions, and 2, 3, 6 positions. Among the hydroxy groups bonded to the three carbon atoms, a case where a hydrogen atom is substituted with a substituent is present in a mixture.

As the reaction solvent used in the hydrolysis reaction, various solvents such as water, alcohols, and organic solvents for dissolving metal salts can be used. These solvents may be used alone or in combination.
Depending on the type of the solvent, a known phase transfer catalyst (for example, a crown ether such as 18-crown-6 or a quaternary ammonium salt such as tetrabutylammonium bromide) may be used.
In the present invention, a solvent having a high solubility of the cellulose derivative having the structure represented by the general formula (2) and a high solubility of the compound (base) having the structure represented by the general formula (1) is particularly preferable. preferable. Examples include N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, 1,3-dimethylimidazolidinone, acetone, acetonitrile, methylene chloride, chloroform and the like.
Particularly preferred are N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, and 1,3-dimethylimidazolidinone.

Although the reaction temperature in the manufacturing method of this invention changes also with the kind of raw material, it is in the range of 0-150 degreeC normally, Preferably it is in the range of 30-80 degreeC.
As a method for adding the reactant, a compound having a structure represented by the general formula (2) as a raw material is added to a solvent, and then a compound (base) having a structure represented by the general formula (1) is added. Is preferred. The base may be added all at once or separately.
Since the reaction time varies depending on the reaction conditions and the like, it cannot be generally determined, but is usually about 3 to 24 hours, preferably about 6 to 12 hours.

  As a means for purifying the cellulose derivative produced after the reaction, a poor solvent of the cellulose derivative is sequentially added to the solution containing the cellulose derivative (crystallization method), or a solution containing the cellulose derivative is added to the cellulose derivative. Although there are methods (precipitation method) for adding to a poor solvent and precipitating, it is not limited to these methods.

The poor solvent to be used may be a solvent having low solubility of the produced cellulose derivative, such as water and alcohols (methanol, ethanol, isopropyl alcohol, butanol, 2-butanol, t-butyl alcohol, pentanol, 2-pen (Tanol, 3-pentanol, etc.), aliphatic hydrocarbons such as hexane, alicyclic hydrocarbons such as cyclohexane, mixed solvent of water and alcohols, mixed solvent of water and acetic acid, mixed solvent of water and acetone, water And a mixed solvent of acetic acid and alcohols (such as methanol, ethanol, isopropyl alcohol, and butanol), a mixed solvent of water, acetone, and alcohols (such as methanol, ethanol, isopropyl alcohol, and butanol), and the like.
The alcohol is preferably methanol.
The amount of the poor solvent used in the purification operation is, for example, in the range of 3 to 20 parts by mass, preferably in the range of 3 to 10 parts by mass with respect to the cellulose derivative reaction solution.
By setting the amount of the poor solvent within the above range, a high-quality cellulose derivative can be efficiently obtained, which is economically advantageous.

For the drying of the crystals obtained by the above purification, a well-known and commonly used method can be used, and examples thereof include a vacuum drying method. The drying pressure in the vacuum drying method is, for example, about full vacuum to about 100 kPa · A, and the drying temperature is, for example, in the range of 20 to 140 ° C.
Examples of the dryer used in the vacuum drying method include a Nauter type dryer, a conical dryer, a paddle dryer, a shelf type dryer, a vibration fluidized dryer, and a band ventilation dryer.

Although the specific example of the cellulose derivative which has a structure represented by General formula (2) and General formula (3) is shown, the compound which can be used by this invention is not limited at all by the following exemplary compounds.

  In the production method of the present invention, the cellulose derivative having the structure represented by the general formula (2) as a raw material is specifically cellulose that is not substituted at all, or hydroxy at the 2nd, 3rd and 6th positions. Cellulose ester in which a part of the group is substituted with an ester group such as an acetyl group, a propionyl group, or a butyl group, or a cellulose in which some of the hydroxyl groups at the 2nd, 3rd and 6th positions of the cellulose ester are further substituted with an ether group There are ester ethers and the like.

These compounds can also be produced by referring to known methods, for example, methods described in “Encyclopedia of Cellulose”, pages 131 to 164 (Asakura Shoten, 2000).
For example, a typical synthesis method of cellulose acetate is a liquid phase acetylation method using acetic anhydride (acetyl group donor), acetic acid (solvent), and sulfuric acid (catalyst).
Specifically, a cellulose raw material such as wood pulp is pretreated with an appropriate amount of acetic acid, and then charged into a precooled acetylated mixed solution to form an acetic ester to synthesize cellulose acetate. After completion of the acetylation reaction, a neutralizing agent (for example, sodium, potassium, calcium, magnesium, iron, etc.) is used for hydrolysis of excess acetic anhydride remaining in the system and neutralization of a part of the esterification catalyst. An aqueous solution of aluminum, zinc or ammonium carbonate, acetate or oxide) is added. The obtained cellulose acetate is aged in the presence of a small amount of an acetylation reaction catalyst (generally, remaining sulfuric acid) by keeping it within a range of 50 to 90 ° C., and a desired degree of acetyl group substitution and degree of polymerization are obtained. It is possible to synthesize cellulose acetate.

The cellulose derivative having the structure represented by the general formula (3) produced by the production method of the present invention is more preferably further substituted with a new substituent to obtain a substituted cellulose derivative.
For example, by substituting with a substituent having UV absorption, a cellulose derivative having reverse wavelength dispersion can be formed and used as a film for λ / 4.

[Method for producing substituted cellulose derivative]
The method for producing a substituted cellulose derivative of the present invention is represented by the cellulose derivative having the structure represented by the general formula (3) and the following general formula (4a), general formula (4b), or general formula (4c). A substituted cellulose derivative having a structure represented by the following general formula (5) is obtained by reacting with a compound having a structure.

<Cellulose derivative having a structure represented by general formula (4a), general formula (4b) or general formula (4c)>
General formula (4a): Rv- (L) q-X
In the general formula (4a), Rv represents an aliphatic group or an aromatic group, and preferably an aromatic group.
Examples of the aliphatic group represented by Rv include a methyl group, an ethyl group, a propyl group, and a heptyl group, and a methyl group or an ethyl group is preferable.
Examples of the aromatic group represented by Rv include a phenyl group, a pyridyl group, a thienyl group, and a naphthyl group, and a phenyl group is preferable.
L represents a carbonyl group.
q represents 0 or 1;
X represents a halogen atom. Examples of the halogen atom include a chlorine atom and a bromine atom, and a chlorine atom is preferable.

Formula (4b): (Rv-L) ₂ O
In the general formula (4b), Rv represents an aliphatic group or an aromatic group, and preferably an aromatic group.
Examples of the aliphatic group represented by Rv include a methyl group, an ethyl group, a propyl group, and a heptyl group, and a methyl group or an ethyl group is preferable.
Examples of the aromatic group represented by Rv include a phenyl group, a pyridyl group, a thienyl group, and a naphthyl group, and a phenyl group is preferable.
L represents a carbonyl group.

General formula (4c): Rv-N = C = Z
In the general formula (4c), Rv represents an aliphatic group or an aromatic group, and preferably an aromatic group.
Examples of the aliphatic group represented by Rv include a methyl group, an ethyl group, a propyl group, and a heptyl group, and a methyl group or an ethyl group is preferable.
Examples of the aromatic group represented by Rv include a phenyl group, a pyridyl group, a thienyl group, and a naphthyl group, and a phenyl group is preferable.
Z represents an oxygen atom or a sulfur atom.

<Substituted cellulose derivative having a structure represented by the general formula (5)>

In the general formula (5), R ₂₁ , R ₃₁ and R ₆₁ each independently represent a hydrogen atom, an aliphatic group or an aromatic group.
However, at least one of R ₂₁ , R ₃₁ and R ₆₁ is Rv derived from a compound having a structure represented by the general formula (4a), the general formula (4b) or the general formula (4c). is there.
L ₂₁ , L ₃₁ and L ₆₁ are each independently formed from one or more groups selected from the group consisting of a single bond, —O—, —CO—, —NHCO or — (Lw—O) q—. Represents a divalent linking group.
Lw represents an alkylene group.
q represents an integer of 0 to 10.
p1 represents an average degree of polymerization and represents an integer of 10 to 2000.

In addition, when at least one of R ₂₁ , R ₃₁ and R ₆₁ is Rv, the degree of substitution with -L ₂₁ -Rv, -L ₃₁ -Rv and -L ₆₁ -Rv is represented by the following formula (c) and The following formula (d) is satisfied.
Formula (c): (Substitution degree by -L ₆₁ -Rv) <(Substitution degree by -L ₂₁ -Rv)
Formula _{(d): (-} L 61 degree of substitution -Rv) _<(- degree of substitution by L 31 -Rv)
-L _{21 -Rv,} and the degree of substitution by _-L 31 -Rv and _-L 61 -Rv, against anhydroglucose unit, 2-position, 3-position and 6-position three hydroxy groups attached to a carbon atom Among these, on average, this is a numerical value representing how many hydrogen atoms are substituted with substituents.

  By reacting a cellulose derivative having a structure represented by the general formula (3) with a compound having a structure represented by the general formula (4a), the general formula (4b) or the general formula (4c), Specific examples of the substituted cellulose derivative having the structure represented by the general formula (5) are shown below.

As for the manufacturing method of the substituted cellulose derivative which has a structure represented by the said General formula (5), the following methods are mentioned, for example.
The cellulose derivative is dissolved in an organic solvent (for example, methylene chloride, dimethylformamide, dimethyl sulfoxide, acetone, tetrahydrofuran, N-methylpyrrolidone, etc.) in which the cellulose derivative is dissolved, and the general formula (4a), general formula (4b), or general A compound represented by the formula (4c) is added, and a base (for example, an organic base such as pyridine or triethylamine, or an inorganic base such as potassium carbonate or sodium carbonate) is added as appropriate, and the reaction is performed at room temperature or with heating.
The obtained composition can be dissolved in a good solvent such as acetone or tetrahydrofuran, and purified by a method such as reprecipitation using a poor solvent such as water, methanol, or ethanol.

[Optical film]
The optical film of the present invention is characterized by containing the above-described cellulose derivative of the present invention, and is preferably a λ / 4 retardation film.

The optical properties of the optical film of the present invention obtained by applying the cellulose derivative of the present invention are not particularly limited, but the in-plane of the film measured at a light wavelength of 550 nm in an environment of a temperature of 23 ° C. and a relative humidity of 55%. The phase difference value Ro ₅₅₀ is in the range of 120 to 160 nm, and the ratio value Ro ₄₅₀ / Ro ₅₅₀ between the phase difference values Ro ₄₅₀ and Ro ₅₅₀ in the film plane measured at light wavelengths of 450 nm and 550 nm, respectively, is 0. It is preferable that it is the structure containing the cellulose derivative which exists in the range of 65-0.99.

  The optical film of the present invention is a long film, and preferably has a slow axis in the range of 40 to 50 ° with respect to the longitudinal direction.

Thus, as a method of making the angle of the slow axis with respect to the long direction into the range of 40-50 degrees, the method of performing the diagonal stretch mentioned later to the film before the stretched film formed can be mentioned. .
The “optical film” in the present invention refers to a film having an optical function of imparting a desired phase difference to transmitted light. As the optical function, for example, linearly polarized light having a specific wavelength is used. Examples include a function of converting to elliptically polarized light or circularly polarized light, or a function of converting elliptically polarized light or circularly polarized light into linearly polarized light.
In particular, the “λ / 4 retardation film” means an optical film having a characteristic that the in-plane retardation of the film is about 1/4 with respect to a predetermined wavelength of light (usually in the visible light region). Say.

<Characteristics of optical film>
Since the optical film of the present invention (hereinafter also referred to as the retardation film of the present invention) obtains circularly polarized light in the visible light wavelength range, the retardation of about 1/4 of the wavelength in the visible light wavelength range. A broadband λ / 4 phase difference film having

The in-plane retardation Ro _λ and the thickness direction retardation Rt _λ of the retardation film of the present invention are represented by the following formula (i). Note that λ represents a wavelength (nm) for measuring each phase difference. The value of the phase difference used in the present invention can be calculated, for example, by measuring the birefringence at each wavelength in an environment of 23 ° C. and 55% relative humidity using an Axoscan manufactured by Axometrics. .

Formula (i)
Ro _λ = (n _xλ −n _yλ ) × d
Rt _λ = [(n _xλ + n _yλ ) / 2−n _zλ ] × d
In the above formula (i), lambda represents an optical wavelength (nm) used in the _{measurement, n x, n y, n} z is, 23 ° C., respectively, as measured in an environment of 55% RH, _{n x} is the film maximum refractive index in-plane represents the (slow axis direction of the refractive index), n _y represents a refractive index in a direction perpendicular to the slow axis in the film plane, n _z is the vertical thickness in the film plane The refractive index of a direction is represented and d represents the thickness (nm) of a film.

Here, when the in-plane retardation of the retardation film at the light wavelength λ (nm) is Ro _λ , in the retardation film of the present invention, the in-plane retardation value Ro ₅₅₀ measured at the light wavelength of 550 nm is 120. Within the range of ˜160 nm, the ratio value Ro ₄₅₀ / Ro ₅₅₀ of the retardation value Ro ₄₅₀ and Ro ₅₅₀ in the film plane measured at the light wavelengths of 450 nm and 550 nm, respectively, is within the range of 0.65 to 0.99. Preferably there is.

The retardation value Ro ₅₅₀ defined in the present invention is preferably in the range of 120 to 160 nm, more preferably in the range of 130 to 150 nm, and still more preferably in the range of 135 to 145 nm. In the optical film of the present invention, when Ro ₅₅₀ is in the range of 120 to 160 nm, the phase difference at a wavelength of 550 nm is approximately ¼ wavelength, and a circularly polarizing plate is produced using an optical film having such characteristics. For example, by providing the organic EL display device with this circularly polarizing plate, performance stability in various usage environments can be improved.

In the optical film of the present invention, Ro ₄₅₀ / Ro ₅₅₀ which is a ratio value of retardation value Ro ₄₅₀ and Ro ₅₅₀ in the film surface which is an indicator of wavelength dispersion characteristics is 0.65 to 0.99. Is preferably in the range of 0.70 to 0.94, and more preferably in the range of 0.75 to 0.89. If Ro ₄₅₀ / Ro ₅₅₀ is in the range of 0.65 to 0.99, the phase difference exhibits an appropriate reverse wavelength dispersion characteristic, and when a long circularly polarizing plate is produced, a wide band of light can be obtained. On the other hand, an antireflection effect is obtained.

On the other hand, the phase difference Rt _λ in the film thickness direction is preferably such that the phase difference Rt ₅₅₀ measured at an optical wavelength of 550 nm is in the range of 60 to 200 nm, more preferably in the range of 70 to 150 nm, More preferably, it is in the range of 100 nm. If Rt ₅₅₀ is in the range of 60 to 200 nm, it is possible to prevent a change in hue when viewed obliquely on a large screen.

<Various additives for optical film>
In addition to the cellulose derivative of the present invention, the optical film of the present invention can contain various additives for the purpose of imparting various functions.

  Additives that can be applied to the present invention are not particularly limited, and are, for example, a retardation increasing agent, a wavelength dispersion improving agent, a deterioration inhibitor, an ultraviolet absorber, a matting agent, a plasticizer, and the like within a range that does not impair the object effects of the present invention. An agent or the like can be used.

  Below, the typical additive applicable to the optical film of this invention is shown.

(UV absorber)
The optical film of the present invention can contain an ultraviolet absorber.

Examples of ultraviolet absorbers include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like, but less benzotriazole compounds Compounds are preferred. In addition, ultraviolet absorbers described in JP-A-10-182621 and JP-A-8-337574 and polymer ultraviolet absorbers described in JP-A-6-148430 are also preferably used.
In the case where the optical film of the present invention is used as a protective film for a polarizing plate in addition to a retardation film, the ultraviolet absorber has an ability to absorb ultraviolet rays having a wavelength of 370 nm or less from the viewpoint of preventing deterioration of a polarizer and an organic EL device. In view of the display property of the organic EL element, it is preferable that the organic EL element has a characteristic that absorbs less visible light having a wavelength of 400 nm or more.

Benzotriazole-based UV absorbers useful in the present invention include, for example, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t -Butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-butyl Phenyl) -5-chlorobenzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5
'-Methylphenyl] benzotriazole, 2,2-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (2'-Hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methyl Phenol, octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl-4- And a mixture of hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate, and the like. .

  Further, as a commercial product, “TINUVIN 109”, “TINUVIN 171”, “TINUVIN 326”, “TINUVIN 328” (above, trade name, manufactured by BASF Japan Ltd.) are preferable. Can be used.

  The addition amount of the ultraviolet absorber is preferably in the range of 0.1 to 5.0% by mass, and more preferably in the range of 0.5 to 5.0% by mass with respect to the cellulose derivative.

(Degradation inhibitor)
A degradation inhibitor such as an antioxidant, a peroxide decomposer, a radical polymerization inhibitor, a metal deactivator, an acid scavenger, and amines may be added to the optical film of the present invention. The deterioration inhibitor is described in, for example, JP-A-3-199201, JP-A-5-97073, JP-A-5-194789, JP-A-5-271471, and JP-A-6-107854. The amount of the deterioration inhibitor added is a cellulose solution (dope) used for the production of an optical film from the viewpoint of suppressing the bleed-out of the deterioration inhibitor to the film surface because of the effect of the addition of the deterioration inhibitor. Is preferably in the range of 0.01 to 1% by mass, and more preferably in the range of 0.01 to 0.2% by mass. Examples of particularly preferred deterioration inhibitors include butylated hydroxytoluene (abbreviation: BHT) and tribenzylamine (abbreviation: TBA).

(Matting agent fine particles)
It is preferable to add fine particles as a matting agent to the optical film of the present invention.
Examples of the matting agent fine particles include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, and magnesium silicate. And calcium phosphate. Among these matting agent fine particles, those containing silicon are preferable in terms of low turbidity (haze), and silicon dioxide is particularly preferable.
The fine particles of silicon dioxide preferably have a primary average particle size in the range of 1 to 20 nm and an apparent specific gravity of 70 g / liter or more. The primary average particle size is preferably within the range of 5 to 16 nm from the viewpoint of reducing the haze of the optical film. The apparent specific gravity is further preferably in the range of 90 to 200 g / liter, particularly preferably in the range of 100 to 200 g / liter. A larger apparent specific gravity is preferable because a high-concentration dispersion can be produced, and haze and aggregates are improved.

  These fine particles usually form secondary particles having an average particle size in the range of 0.05 to 2.0 μm. These secondary particles exist as an aggregate of primary particles in the optical film, and form irregularities of 0.05 to 2.0 μm on the optical film surface. The secondary average particle size is preferably in the range of 0.05 to 1.0 μm, more preferably in the range of 0.1 to 0.7 μm, and particularly preferably in the range of 0.1 to 0.4 μm. The primary particle size and the secondary particle size were determined by observing fine particles in the optical film with a scanning electron microscope and determining the diameter of a circle circumscribing the particles as the particle size. Also, 200 particles are observed at different locations, and the average value is taken as the average particle size.

  As the silicon dioxide fine particles, for example, commercially available products such as Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (above, Nippon Aerosil Co., Ltd., trade name) may be used. it can. Zirconium oxide fine particles are commercially available, for example, as Aerosil R976 and R811 (above, trade name, manufactured by Nippon Aerosil Co., Ltd.) and can be used.

  Among these, Aerosil 200V and Aerosil R972V are fine particles of silicon dioxide having a primary average particle size of 20 nm or less and an apparent specific gravity of 70 g / liter or more, and the friction coefficient is maintained while keeping the haze of the optical film low. This is particularly preferable because the effect of lowering is great.

  The matting agent fine particles are preferably prepared by the following method and applied to an optical film. That is, a matting agent fine particle dispersion in which a solvent and matting agent fine particles are stirred and mixed is prepared in advance, and this matting agent fine particle dispersion is added to various additive solutions prepared separately with a cellulose derivative concentration of less than 5% by mass. After stirring and dissolving, a method of further mixing with the main cellulose derivative dope is preferable.

  Since the surface of the matting agent fine particles is hydrophobized, when an additive having hydrophobicity is added, the additive is adsorbed on the surface of the matting agent fine particles, and the aggregate of the additive is formed using this as a core. Likely to happen. Therefore, by mixing a relatively hydrophilic additive with the matting agent fine particle dispersion in advance and then mixing a hydrophobic additive, aggregation of the additive on the surface of the matting agent can be suppressed. Is low, and light leakage in black display when incorporated in a liquid crystal display device is preferable.

  It is preferable to use an in-line mixer for mixing the matting agent fine particle dispersant and the additive solution and mixing the cellulose derivative dope. Although the present invention is not limited to these methods, the concentration of silicon dioxide when the silicon dioxide fine particles are mixed and dispersed with a solvent or the like is preferably within the range of 5 to 30% by mass, and within the range of 10 to 25% by mass. More preferably, it is in the range of 15 to 20% by mass. A higher dispersion concentration is preferable because turbidity with respect to the same amount of addition is reduced, and generation of haze and aggregates can be suppressed. The addition amount of the matting agent in the final cellulose derivative dope solution is preferably in the range of 0.001 to 1.0% by mass, more preferably in the range of 0.005 to 0.5% by mass. A range of 01 to 0.1% by mass is particularly preferable.

[Method for producing optical film containing cellulose derivative]
The method for producing the optical film of the present invention is not particularly limited, but a method for producing by the solvent casting method (solution casting method) is preferable. In the solvent cast method, an optical film is produced using a solution (dope) in which a cellulose derivative is dissolved in an organic solvent.

  The organic solvent used for the preparation of the dope includes ethers having 3 to 12 carbon atoms, ketones having 3 to 12 carbon atoms, esters having 3 to 12 carbon atoms, and 1 to 6 carbon atoms. It is preferable to use a solvent selected from halogenated hydrocarbons.

  Ethers, ketones and esters may have a cyclic structure. A compound having two or more functional groups of ethers, ketones and esters (that is, —O—, —CO— and —COO—) can also be used as the organic solvent. The organic solvent may have other functional groups such as alcoholic hydroxy groups. In the case of an organic solvent having two or more types of functional groups, the number of carbon atoms is preferably within the range of the above-mentioned preferable number of carbon atoms of the solvent having any functional group.

  Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole, phenetole and the like.

  Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclohexanone, and methylcyclohexanone.

  Examples of esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, pentyl acetate and the like.

  Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol, 2-butoxyethanol and the like.

  The number of carbon atoms of the halogenated hydrocarbon is preferably 1 or 2, and most preferably 1. The halogen of the halogenated hydrocarbon is preferably chlorine. The proportion of halogen atoms in the halogenated hydrocarbon substituted with halogen is preferably in the range of 25 to 75 mol%, more preferably in the range of 30 to 70 mol%, and more preferably 35 to 65 mol%. More preferably within the range of mol%, particularly preferably within the range of 40 to 60 mol%. Methylene chloride is a representative halogenated hydrocarbon.

  For the preparation of the dope, it is preferable to use a mixed solvent of methylene chloride and alcohols, and the ratio of alcohols to methylene chloride is preferably in the range of 1 to 50% by mass, and in the range of 5 to 40% by mass. The range of 8 to 30% by mass is particularly preferable. As the alcohol, methanol, ethanol, and n-butanol are preferable, and two or more kinds of alcohols may be mixed and used.

  The dope can be prepared by a general method under a temperature of 0 ° C. or higher (room temperature or high temperature). The solution can be prepared by using a dope preparation method and apparatus in a normal solvent cast method. In the case of a general method, it is preferable to use a halogenated hydrocarbon (particularly methylene chloride) as the organic solvent.

  The concentration of the cellulose derivative in the dope is preferably in the range of 5 to 40% by mass, and more preferably in the range of 10 to 30% by mass. Various additives described above may be added to the organic solvent (main solvent).

  The dope can be prepared by stirring a cellulose derivative and an organic solvent at room temperature (0 to 40 ° C.). High concentration solutions may be stirred under pressure and heating conditions. Specifically, the cellulose derivative and the organic solvent are placed in a pressure vessel and sealed, and stirred while being heated to a temperature not lower than the boiling point of the solvent at normal temperature and in a range where the solvent does not boil.

  The heating temperature is usually 40 ° C or higher, preferably in the range of 60 to 200 ° C, more preferably in the range of 80 to 110 ° C.

  Each component may be roughly mixed in advance and then charged into the container. Moreover, you may put into a container sequentially. The container must be provided with a mechanism capable of stirring. An inert gas such as nitrogen gas can be injected to pressurize the container. Moreover, you may pressurize using the raise of the vapor pressure of the solvent by heating. Or after sealing a container, you may add each component under pressure.

  When heating, the method of heating from the outer peripheral part of a container is preferable. For example, a jacket type heating device can be used. Further, the entire container can be heated by providing a plate heater outside the container, or by installing a pipe on the outer periphery of the container and circulating the heated liquid in the pipe.

  It is preferable to provide a stirring blade inside the container and use this to stir. The stirring blade preferably has a length that reaches the vicinity of the wall of the container. A scraping blade is preferably provided at the end of the stirring blade in order to renew the liquid film on the vessel wall.

  Instruments such as a pressure gauge and a thermometer may be installed in the container. Each component is dissolved in a solvent in a container. The prepared dope is taken out of the container after cooling, or is taken out and then cooled using a heat exchanger or the like.

  A solution can also be prepared by a cooling dissolution method. In the cooling dissolution method, the cellulose derivative can be dissolved in an organic solvent that is difficult to dissolve by a normal dissolution method. In addition, even if it is a solvent which can melt | dissolve a cellulose derivative with a normal melt | dissolution method, there exists an effect by which a rapid and uniform solution is obtained by applying the cooling melt | dissolution method.

  In the cooling dissolution method, first, a cellulose derivative is gradually added to an organic solvent with stirring at room temperature. The amount of the cellulose derivative is preferably adjusted so as to be contained in the mixture in the range of 5 to 40% by mass. The amount of the cellulose derivative is more preferably in the range of 10 to 30% by mass. Furthermore, you may add the above-mentioned arbitrary additive in a mixture.

Next, the mixture is cooled within a range of −100 to −10 ° C. (preferably −80 to −10 ° C., more preferably −50 to −20 ° C., particularly preferably −50 to −30 ° C.).
The cooling can be performed, for example, in a dry ice / methanol bath (−75 ° C.) or a cooled diethylene glycol solution (−30 to −20 ° C.). By cooling, the mixture of the cellulose derivative and the organic solvent is solidified.

The cooling rate is preferably 4 ° C./min or more, more preferably 8 ° C./min or more, and particularly preferably 12 ° C./min or more. The faster the cooling rate, the better. However, 10,000 ° C./second is the theoretical upper limit, 1000 ° C./second is the technical upper limit, and 100 ° C./second is the practical upper limit.
The cooling rate is a value obtained by dividing the difference between the temperature at the start of cooling and the final cooling temperature by the time from the start of cooling to the final cooling temperature.

  Furthermore, when this is heated within the range of 0 to 200 ° C. (preferably 0 to 150 ° C., more preferably 0 to 120 ° C., and still more preferably 0 to 50 ° C.), the cellulose derivative is dissolved in the organic solvent. . The temperature may be increased by simply leaving it at room temperature or in a warm bath.

  The heating rate is preferably 4 ° C./min or more, more preferably 8 ° C./min or more, and even more preferably 12 ° C./min or more. The higher the heating rate, the better. However, 10,000 ° C./second is the theoretical upper limit, 1000 ° C./second is the technical upper limit, and 100 ° C./second is the practical upper limit. The heating rate is the value obtained by dividing the difference between the temperature at the start of heating and the final heating temperature by the time from the start of heating until the final heating temperature is reached. is there.

  A uniform solution is obtained as described above. If the dissolution is insufficient, the cooling and heating operations may be repeated. Whether or not the dissolution is sufficient can be determined by merely observing the appearance of the solution with the naked eye.

  In the cooling dissolution method, it is preferable to use an airtight container in order to avoid moisture mixing due to condensation during cooling. In the cooling and heating operation, when the pressure is applied during cooling and the pressure is reduced during heating, the dissolution time can be shortened. In order to perform pressurization and pressure reduction, it is preferable to use a pressure-resistant container.

  An optical film having a cellulose derivative is produced from the prepared cellulose derivative solution (dope) by a solvent cast method.

<Solution casting method>
The optical film of the present invention is preferably manufactured by the solution casting method as described above.
In the solution casting method, a step of preparing a dope by heating and dissolving a cellulose derivative and various additives satisfying the characteristics specified in the present invention in an organic solvent, and the prepared dope on a belt-shaped or drum-shaped metal support Includes a step of casting, a step of drying the cast dope as a web, a step of peeling from the metal support, a step of stretching or shrinking the peeled web, a step of drying, a step of winding up the finished film, etc. .

The dope is cast on a drum or band and the solvent is evaporated to form a film. It is preferable to adjust the concentration of the dope before casting so that the solid content is in the range of 18 to 35%. The surface of the drum or band is preferably finished in a mirror state.
The dope is preferably cast on a drum or band having a surface temperature of 10 ° C. or less.

Regarding the drying method in the solvent cast method, U.S. Pat. Nos. 2,336,310, 2,367,603, 2,492,078, 2,492,977, 2, Nos. 492,978, 2,607,704, 2,739,069 and 2,739,070, British Patent Nos. 640,731 and 736,892 As well as Japanese Patent Publication Nos. 45-4554, 49-5614, JP-A-60-176834, JP-A-60-203430, and JP-A-62-115035.
Drying on the drum or band can be performed by blowing an inert gas such as air or nitrogen to the cast film.

The prepared cellulose derivative solution (dope) can be cast into two or more layers to form a film. In this case, it is preferable to produce a cellulose derivative film by a solvent cast method. The dope is cast on a drum or band and the solvent is evaporated to form a film.
It is preferable to adjust the concentration of the dope before casting so that the solid content is in the range of 5 to 40%.
The surface of the drum or band is preferably finished in a mirror state.

<Extension process>
As described above, the optical film (retardation film) of the present invention preferably has an in-plane retardation Ro ₅₅₀ measured at a light wavelength of 550 nm in the range of 120 to 160 nm, but was formed as described above. The properties can be imparted by stretching the optical film.

  The stretching method applicable to the present invention is not particularly limited. For example, a method in which a circumferential speed difference is applied to a plurality of rollers and a longitudinal stretching is performed using a circumferential speed difference between the plurality of rollers therebetween. , Both ends of the web are fixed with clips and pins, and the distance between the clips and pins is extended in the longitudinal direction according to the direction of travel, similarly the method of extending in the horizontal direction and extending in the horizontal direction, or the vertical and horizontal directions are expanded at the same time. The method of extending | stretching to both directions is employable individually or in combination.

  That is, the film may be stretched in the transverse direction, longitudinally, or in both directions with respect to the film forming direction, and when stretched in both directions, simultaneous stretching or sequential stretching may be used. May be. In the case of the so-called tenter method, driving the clip portion by the linear drive method is preferable because smooth stretching can be performed and the risk of breakage and the like can be reduced.

  As the stretching process, the film is usually stretched in the width direction (TD direction) and contracted in the transport direction (MD direction), but when contracted, it is easy to match the main chain direction when transported in an oblique direction. In addition, the phase difference effect is even greater. The shrinkage rate can be determined by the transport angle.

  FIG. 1 is a schematic diagram for explaining the shrinkage ratio in oblique stretching.

In Figure 1, when the oblique stretching the optical film F in the direction of the reference numerals A2, the optical film F shrinks to M ₂ by being obliquely bent. That is, when the gripping tool that grips the optical film F advances as it is without bending at the bending angle θ, it should advance by a length M ₁ ′ in a predetermined time. However, in reality, it bends at a bending angle θ and proceeds by M ₁ (where M ₁ = M ₁ ′). At this time, since the gripping tool advances by M ₂ in the film entering direction (direction orthogonal to the stretching direction (TD direction) A1), the optical film F has a length M ₃ (where M ₃ = M ₁ -M ₂₎ the fact that only shrinkage.

At this time, the shrinkage rate (%) is
Shrinkage rate (%) = (M ₁ −M ₂ ) / M ₁ × 100. If the bending angle is θ,
M ₂ = M ₁ × sin (π−θ), and the shrinkage rate is
Shrinkage rate (%) = (1-sin (π−θ)) × 100

  In FIG. 1, reference numeral 11 is a stretching direction (TD direction), reference numeral 13 is a transport direction (MD direction), and reference numeral 14 indicates a slow axis.

  In consideration of the productivity of the long circularly polarizing plate, the optical film (retardation film) of the present invention has an orientation angle of 45 ° ± 2 ° with respect to the transport direction. Can be bonded, which is preferable.

(Stretching with an oblique stretching device)
Next, the oblique stretching method of stretching in the 45 ° direction will be further described.
In the method for producing an optical film of the present invention, an oblique stretching apparatus is preferably used as a method for imparting an oblique orientation to the optical film to be stretched.

  As an oblique stretching apparatus applicable to the present invention, the orientation angle of the film can be freely set by changing the rail pattern in various ways, and the orientation axis of the film can be oriented with high accuracy evenly in the left-right direction across the film width direction. It is preferable to be a film stretching apparatus capable of controlling the film thickness and retardation with high accuracy.

  FIG. 2 is a schematic view showing an example of a rail pattern of an oblique stretching apparatus applicable to the production of the optical film of the present invention. In addition, FIG. 2 shown here is an example, Comprising: The extending | stretching apparatus applicable in this invention is not limited to this.

In general, in the oblique stretching apparatus, as shown in FIG. 2, the feeding direction D1 of the long film original is different from the winding direction D2 of the stretched film after stretching, and forms a feeding angle θi. doing. The feeding angle θi can be arbitrarily set to a desired angle in the range of more than 0 ° and less than 90 °.
In the present specification, the term “long” refers to a film having a length of at least about 5 times the width of the film, preferably a film having a length of 10 times or more.

  The long film original is gripped at both ends by the left and right gripping tools (tenters) at the entrance of the oblique stretching apparatus (position A in the figure), and travels as the gripping tool travels. The left and right gripping tools are the left and right gripping tools Ci and Co at the entrance of the oblique stretching apparatus (position A in the figure) and facing the direction substantially perpendicular to the film traveling direction (feeding direction D1). The film travels on the asymmetric rails Ri and Ro, and the film gripped by the tenter is released at the position at the end of stretching (position B in the figure).

  At this time, as the left and right gripping tools facing each other at the entrance of the oblique stretching device (position A in the figure) travel on the left and right asymmetric rails Ri and Ro, the gripping tool Ci traveling on the Ri side becomes the Ro side. The positional relationship is advancing with respect to the gripping tool Co traveling.

  That is, at the entrance of the oblique stretching apparatus (the grip start position by the film gripping tool) A, the gripping tools Ci and Co that are opposed to the film feeding direction D1 are positioned at the end of the film stretching. In the state of B, the straight line connecting the grippers Ci and Co is inclined by an angle θL with respect to a direction substantially perpendicular to the film winding direction D2.

  According to the above method, the original film is stretched obliquely. Here, “substantially vertical” indicates that the angle is in a range of 90 ± 1 °.

  More specifically, in the method for producing the optical film of the present invention, it is preferable to perform oblique stretching using the tenter capable of oblique stretching described above.

This stretching apparatus is an apparatus that heats a film raw fabric to an arbitrary temperature at which stretching can be performed and obliquely stretches the film.
This stretching apparatus includes a heating zone, a pair of rails on the left and right on which a gripping tool for transporting the film travels, and a number of gripping tools that travel on the rails.
Both ends of the film sequentially supplied to the inlet of the stretching apparatus are gripped by a gripping tool, the film is guided into the heating zone, and the film is released from the gripping tool at the outlet of the stretching apparatus. The film released from the gripping tool is wound around the core. Each of the pair of rails has an endless continuous track, and the gripping tool which has released the grip of the film at the outlet portion of the stretching apparatus travels outside and is sequentially returned to the inlet portion.

The rail pattern of the stretching device has an asymmetric shape on the left and right, and the rail pattern can be adjusted manually or automatically depending on the orientation angle, stretch ratio, etc. given to the long stretched film to be manufactured. It has become.
In the oblique stretching apparatus used in the present invention, it is preferable that the position of each rail portion and the rail connecting portion can be freely set, and the rail pattern can be arbitrarily changed (the ○ portion in FIG. 2 indicates an example of the connecting portion). ).

In the present invention, the gripping tool of the stretching apparatus travels at a constant speed with a constant interval from the front and rear gripping tools. The traveling speed of the gripping tool can be selected as appropriate, but is usually in the range of 1 to 100 m / min.
The difference in travel speed between the pair of left and right grippers is usually 1% or less, preferably 0.5% or less, more preferably 0.1% or less of the travel speed. This is because if there is a difference in the traveling speed between the left and right sides of the film at the exit of the stretching process, wrinkles and shifts occur at the exit of the stretching process, so the speed difference between the left and right gripping tools is required to be substantially the same speed. Because.
In general stretching equipment, etc., there is a speed unevenness that occurs in the order of seconds or less depending on the period of the sprocket teeth driving the chain, the frequency of the drive motor, etc. This does not correspond to the speed difference described in the invention.

  In the stretching apparatus applicable to the present invention, a large bending rate is often required for the rail that regulates the locus of the gripping tool, particularly in a portion where the film is transported obliquely. For the purpose of avoiding interference between gripping tools due to sudden bending or local stress concentration, it is preferable that the trajectory of the gripping tool draws a curve at the bent portion.

  In the present invention, the long film original fabric is gripped in order by the right and left gripping tools at the entrance of the oblique stretching apparatus (position A in the drawing) and travels as the gripping tool travels. The left and right gripping tools facing the direction substantially perpendicular to the film traveling direction (feeding direction D1) at the entrance of the oblique stretching apparatus (position A in the figure) run on a rail that is asymmetrical to the preheating zone. Through a heating zone having a stretching zone and a heat setting zone.

  The preheating zone refers to a section that travels while maintaining a constant interval between the gripping tools that grip both ends at the entrance of the heating zone.

  The stretching zone refers to a section where the gap between the gripping tools gripping both ends starts to reach a predetermined distance. In the stretching zone, the oblique stretching as described above is performed, but the stretching may be performed in the longitudinal direction or the lateral direction before and after the oblique stretching as necessary. In the case of oblique stretching, there is contraction in the MD direction (fast axis direction) which is a direction perpendicular to the slow axis during bending.

In the optical film of the present invention, an optical modifier (for example, a compound represented by the above general formula (A) described above) deviated from the main chain of the cellulose derivative that is a matrix resin by performing a shrinkage treatment following the stretching treatment. ) In the direction perpendicular to the stretching direction (fast axis direction), thereby rotating the orientation state of the optical adjusting agent so that the main axis of the optical adjusting agent is aligned with the main chain of the cellulose derivative as the matrix resin. be able to. As a result, it is possible to increase the refractive index n _Y280 of the fast axis direction in the ultraviolet region 280 nm, can be a steep slope of n _y order chromatic dispersion in the visible light region.

  The heat setting zone refers to a section in which the gripping tools at both ends run in parallel with each other in a period in which the interval between the gripping tools after the stretching zone becomes constant again. You may pass through the area (cooling zone) by which the temperature in a zone is set to below the glass transition temperature Tg of the thermoplastic resin which comprises a film, after passing through a heat setting zone. At this time, in consideration of shrinkage of the film due to cooling, a rail pattern that narrows the gap between the opposing gripping tools in advance may be used.

  The temperature of each zone is the glass transition temperature Tg of the thermoplastic resin, the temperature of the preheating zone is in the range of Tg to Tg + 30 ° C., the temperature of the stretching zone is in the range of Tg to Tg + 30 ° C., and the temperature of the cooling zone is It is preferable to set within the range of Tg-30 ° C to Tg.

  In order to control thickness unevenness in the width direction, a temperature difference may be given in the width direction in the stretching zone. In order to give a temperature difference in the width direction in the stretching zone, a method of adjusting the opening degree of the nozzle for sending warm air into the temperature-controlled room so as to make a difference in the width direction, and controlling heating by arranging heaters in the width direction are known. Can be used.

  The length of the preheating zone, the stretching zone, the shrinking zone and the cooling zone can be appropriately selected. The length of the preheating zone is usually within a range of 100 to 150% with respect to the length of the stretching zone, and the length of the fixed zone. Is usually in the range of 50 to 100%.

The draw ratio (W / Wo) in the drawing step is preferably in the range of 1.3 to 3.0, more preferably in the range of 1.5 to 2.8. When the draw ratio is within this range, the thickness unevenness in the width direction can be reduced.
In the stretching zone of the oblique stretching apparatus, it is possible to further improve the uneven thickness in the width direction by making a difference in the stretching temperature in the width direction. In addition, Wo represents the width of the film before stretching, and W represents the width of the film after stretching.

  As an oblique stretching method applicable in the present invention, in addition to the method shown in FIG. 2, the stretching methods shown in FIGS. 3 (a) to 3 (c) and FIGS. 4 (a) and 4 (b) are given. be able to.

FIG. 3 is a schematic view showing an example of a production method applicable to the present invention (an example in which the film is drawn from a long film original fabric roller and then obliquely stretched), and the long film original fabric once wound up in a roll shape. The pattern which extends | stretches and diagonally stretches is shown.
FIG. 4 is a schematic view showing an example of another manufacturing method applicable to the present invention (an example of continuous oblique stretching without winding a long film original), and winding the long film original. The pattern which performs a diagonal stretch process continuously, without showing is shown.

  3 and 4, reference numeral 15 denotes an oblique stretching apparatus, reference numeral 16 denotes a film feeding apparatus, reference numeral 17 denotes a transport direction changing apparatus, reference numeral 18 denotes a winding apparatus, and reference numeral 19 denotes a film forming apparatus. In each figure, the code | symbol which shows the same thing may be abbreviate | omitted.

The film feeding device 16 is slidable and swivelable or slidable so that the film can be fed out at a predetermined angle with respect to the oblique stretching device inlet. It is preferable to be able to send
(A)-(c) of FIG. 3 has shown the pattern which changed arrangement | positioning of the film delivery apparatus 16 and the conveyance direction change apparatus 17, respectively.
4A and 4B show a pattern in which the film formed by the film forming apparatus 19 is directly fed to the stretching apparatus 15.
By configuring the film feeding device 16 and the conveyance direction changing device 17 in such a configuration, it becomes possible to further narrow the width of the entire manufacturing apparatus, and to finely control the film feeding position and angle. Thus, it becomes possible to obtain a long stretched film with small variations in film thickness and optical value. In addition, by making the film feeding device 16 and the transport direction changing device 17 movable, it is possible to effectively prevent the left and right clips from being caught in the film.

By arranging the winding device 18 so that the film can be pulled at a predetermined angle with respect to the outlet of the oblique stretching device, it is possible to finely control the film take-up position and angle, and variations in film thickness and optical value. It becomes possible to obtain a long stretched film having a small diameter. Therefore, it is possible to effectively prevent the film from being wrinkled and to improve the winding property of the film, so that the film can be wound up in a long length.
In the present invention, the take-up tension T (N / m) of the stretched film is adjusted within a range of 100 N / m <T <300 N / m, preferably 150 N / m <T <250 N / m. .

<Melt film forming method>
The optical film (λ / 4 retardation film) of the present invention may be formed by a melt film forming method in addition to the solution casting method described above.
The melt film forming method is a molding method in which a composition containing an additive such as a cellulose derivative and a plasticizer is heated and melted to a temperature exhibiting fluidity, and then cast as a melt containing a fluid thermoplastic resin. is there.

  The molding method for heating and melting can be classified into, for example, a melt extrusion molding method, a press molding method, an inflation method, an injection molding method, a blow molding method, and a stretch molding method. Among these molding methods, the melt extrusion molding method is preferable from the viewpoint of mechanical strength and surface accuracy.

The plurality of raw materials used in the melt extrusion method are usually preferably kneaded and pelletized in advance.
Pelletization can be performed by a known method. For example, dry cellulose derivatives, plasticizers, and other additives are fed to an extruder with a feeder, kneaded using a single or twin screw extruder, and then from a die. It can be obtained by extruding into a strand, cooling with water or air, and cutting.

The additives may be mixed before being supplied to the extruder, or may be supplied by individual feeders.
A small amount of additives such as matting agent fine particles and antioxidants are preferably mixed in advance in order to mix uniformly.

  The extruder used for pelletization preferably has a method of suppressing the shearing force and processing at the lowest possible temperature so that the resin can be pelletized so that the resin does not deteriorate (molecular weight reduction, coloring, gel formation, etc.). For example, in the case of a twin screw extruder, it is preferable to rotate in the same direction using a deep groove type screw. From the uniformity of kneading, the meshing type is preferable.

  A film is formed using the pellets obtained as described above. Of course, it is also possible to form the film as it is after it is not formed into pellets, and the raw material powder is put into the feeder as it is, supplied to the extruder, heated and melted.

  Using a single-screw or twin-screw type extruder, the melting temperature when extruding is within the range of 200 to 300 ° C., filtered through a leaf disk type filter or the like to remove foreign matter, and then from the T-die. The film is cast into a film, and the film is nipped with a cooling roller and an elastic touch roller, and solidified on the cooling roller.

  When introducing into the extruder from the supply hopper, it is preferable to carry out under vacuum or reduced pressure or in an inert gas atmosphere to prevent oxidative decomposition and the like.

  The extrusion flow rate is preferably performed stably by introducing a gear pump or the like. Further, a stainless fiber sintered filter is preferably used as a filter used for removing foreign substances. A stainless steel fiber sintered filter is a product in which stainless steel fiber bodies are intricately intertwined and compressed, and the contact points are sintered and integrated. The density is changed according to the thickness of the fiber and the amount of compression, and filtration is performed. The accuracy can be adjusted.

  Additives such as plasticizers and fine particles may be mixed with the resin in advance, or may be kneaded in the middle of the extruder. In order to add uniformly, it is preferable to use a mixing apparatus such as a static mixer.

The film temperature on the touch roller side when the film is nipped between the cooling roller and the elastic touch roller is preferably in the range of Tg to Tg + 110 ° C. of the film.
A known elastic touch roller can be used as the elastic touch roller having an elastic surface used for such a purpose. The elastic touch roller is also called a pinching rotary body, and a commercially available one can also be used.

  When peeling the film from the cooling roller, it is preferable to control the tension to prevent deformation of the film.

The film obtained as described above can be subjected to stretching and shrinkage treatment by stretching operation after passing through the step of contacting the cooling roller.
As a method of stretching and shrinking, a known roller stretching device or oblique stretching device as described above can be preferably used. The stretching temperature is usually preferably performed in the temperature range of Tg to Tg + 60 ° C. of the resin constituting the film.

Before winding, the end may be slit and cut to the width to be the product, and knurling (embossing) may be applied to both ends to prevent sticking and scratching during winding.
The knurling method can process a metal ring having an uneven pattern on its side surface by heating or pressing. In addition, since the film has deform | transformed and cannot use as a product normally, the holding | grip part of the clip of both ends of a film is cut out and reused.

The retardation film of the present invention can be formed into a circularly polarizing plate by laminating so that the angle between the slow axis and the transmission axis or absorption axis of the polarizer described later is substantially 45 °.
In the present invention, “substantially 45 °” means within a range of 40 to 50 °.

  The angle between the in-plane slow axis of the retardation film of the present invention and the transmission axis or absorption axis of the polarizer is preferably in the range of 41 to 49 °, and in the range of 42 to 48 °. It is more preferable that it is within the range of 43 to 47 °, and it is particularly preferable that it is within the range of 44 to 46 °.

[Circularly polarizing plate]
The circularly polarizing plate of the present invention is obtained by cutting a long roll having a long protective film, a long polarizer and a long optical film (λ / 4 retardation film) of the present invention in this order. Produced.
Since the circularly polarizing plate of the present invention is produced using the optical film (λ / 4 retardation film) of the present invention, it can be applied to all the wavelengths of visible light by applying it to an organic EL display device described later. An effect of shielding the specular reflection of the metal electrode of the EL element can be exhibited. As a result, reflection during observation can be prevented and black expression can be improved.

In addition, the circularly polarizing plate of the present invention preferably has an ultraviolet absorption function.
It is preferable that the protective film on the viewing side has an ultraviolet absorbing function from the viewpoint that both the polarizer and the organic EL element can exhibit a protective effect against ultraviolet rays.
Furthermore, when the retardation film on the light emitter side also has an ultraviolet absorbing function, when used in an organic EL display device described later, deterioration of the organic EL element can be further suppressed.

In addition, the circularly polarizing plate of the present invention has an optical film (λ / 4 position) in which the angle of the slow axis (that is, the orientation angle θ) is adjusted to be “substantially 45 °” with respect to the longitudinal direction. By using the retardation film, it is possible to form an adhesive layer and bond the polarizer and the retardation film together by a consistent production line.
Specifically, after finishing the step of producing a polarizer by stretching a polarizing film, a step of laminating a polarizer and a retardation film can be incorporated during or after the subsequent drying step, Each can be continuously supplied, and can be connected in a production line that is consistent with the next process by winding in a roll state after bonding.
In addition, when bonding a polarizer and retardation film, a protective film can also be simultaneously supplied in a roll state and can also be bonded continuously. From the viewpoint of performance and production efficiency, it is preferable to simultaneously bond a retardation film and a protective film to a polarizer. That is, after finishing the step of producing a polarizer by stretching the polarizing film, during the subsequent drying step or after the drying step, the protective film and the retardation film are respectively bonded to both sides with an adhesive, It is also possible to obtain a rolled circularly polarizing plate.

  In the circularly polarizing plate of the present invention, the polarizer is preferably sandwiched between the optical film (λ / 4 retardation film) of the present invention and a protective film, and a cured layer is laminated on the viewing side of the protective film. preferable.

  The circularly polarizing plate can be provided in a liquid crystal display device or an organic electroluminescence image display device. By applying the circularly polarizing plate to an organic electroluminescence image display device as an example, the specular reflection of the metal electrode of the organic electroluminescence light emitter can be achieved. Expresses the shielding effect.

<Protective film>
In the circularly polarizing plate, the polarizer is preferably sandwiched between the optical film of the present invention and the protective film.
As such a protective film, other cellulose ester-containing films are suitably used. For example, a commercially available cellulose ester film (for example, Konica Minoltack KC8UX, KC5UX, KC4UX, KC8UCR3, KC4SR, KC4BR, KC4CR, KC4DR, KC4FR , KC4KR, KC8UY, KC6UY, KC4UY, KC4UE, KC8UE, KC8UY-HA, KC2UA, KC4UA, KC6UAKC, 2UAH, KC4UAH, KC6UAH, Z TD60UL, Fujitac TD40UL, Fujitac R02, Fujitac R06, Fujifilm Corporation) Used properly.
Although the thickness in particular of a protective film is not restrict | limited, It can be set as about 10-200 micrometers, Preferably it exists in the range of 10-100 micrometers, More preferably, it exists in the range of 10-70 micrometers.

(Polarizer)
A polarizer is an element that passes only light having a plane of polarization in a certain direction. Examples thereof include a polyvinyl alcohol polarizing film.
The polyvinyl alcohol polarizing film includes those obtained by dyeing iodine on a polyvinyl alcohol film and those obtained by dyeing a dichroic dye.

The polarizer can be obtained by uniaxially stretching a polyvinyl alcohol film and then dyeing; or after dying a polyvinyl alcohol film and uniaxially stretching, and preferably by further performing a durability treatment with a boron compound.
The film thickness of the polarizer is preferably in the range of 5 to 30 μm, and more preferably in the range of 5 to 15 μm.

  Examples of the polyvinyl alcohol film include ethylene unit content of 1 to 4 mol%, polymerization degree of 2000 to 4000, and saponification degree of 99.0 to 99 described in JP2003-248123A, JP2003-342322A, and the like. 99 mol% ethylene-modified polyvinyl alcohol is preferably used. Moreover, it is preferable to produce a polarizing plate by the method of Unexamined-Japanese-Patent No. 2011-1000016, patent 4691205, and patent 4804589, and sticking it with the optical film of this invention.

<Adhesive>
The bonding of the optical film of the present invention and the polarizer is not particularly limited, but can be performed using a completely saponified polyvinyl alcohol adhesive after saponifying the optical film.
It can also be bonded using an actinic ray curable adhesive or the like. However, since the elastic modulus of the obtained adhesive layer is high and the deformation of the polarizing plate is easily suppressed, the bonding using the photocurable adhesive is possible. It is preferable to be a combination.

  Preferred examples of the photocurable adhesive include (α) a cationic polymerizable compound, (β) a photo cationic polymerization initiator, and (γ) a wavelength longer than 380 nm, as disclosed in JP2011-08234A. And a photo-curable adhesive composition containing each component of a photosensitizer exhibiting maximum absorption in the light of (δ) and a naphthalene-based photosensitization aid. However, other photocurable adhesives may be used.

[Production method of polarizing plate]
Hereinafter, an example of the manufacturing method of the polarizing plate using a photocurable adhesive agent is demonstrated.
The polarizing plate includes (1) a pretreatment step for easily adhering the surface of the optical film to which the polarizer is bonded, and (2) at least one of the adhesive surfaces of the polarizer and the optical film. (3) A bonding step of bonding the polarizer and the optical film through the obtained adhesive layer, and 4) A polarizer and the optical film are bonded through the adhesive layer. It can manufacture by the manufacturing method including the hardening process which hardens an adhesive bond layer in the match | combined state. What is necessary is just to implement the pre-processing process of (1) as needed.

<Pretreatment process>
In the pretreatment step, an easy adhesion treatment is performed on the adhesive surface of the optical film with the polarizer.
When bonding an optical film to both surfaces of a polarizer, easy adhesion processing is performed on the bonding surface of each optical film with the polarizer.
Examples of the easy adhesion treatment include corona treatment and plasma treatment.

<Adhesive application process>
In the adhesive application step, the photocurable adhesive is applied to at least one of the adhesive surfaces of the polarizer and the optical film.
When the photocurable adhesive is directly applied to the surface of the polarizer or the optical film, the application method is not particularly limited. For example, various coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater can be used.
Moreover, after casting a photocurable adhesive between a polarizer and an optical film, the method of pressurizing with a roller etc. and spreading uniformly can also be utilized.

<Bonding process>
Thus, after apply | coating a photocurable adhesive agent, it uses for a bonding process.
In this bonding step, for example, when a photocurable adhesive is applied to the surface of the polarizer in the previous application step, an optical film is superimposed thereon. When a photocurable adhesive is applied to the surface of the optical film in the previous application step, a polarizer is superimposed thereon.
In addition, when a photocurable adhesive is cast between the polarizer and the optical film, the polarizer and the optical film are superposed in that state. In the case where the optical film is bonded to both surfaces of the polarizer, and the photocurable adhesive is used on both surfaces, the optical film is superimposed on the both surfaces of the polarizer via the photocurable adhesive. Usually, in this state, both sides (if the optical film is superimposed on one side of the polarizer, the polarizer side and the optical film side, and if the optical film is superimposed on both sides of the polarizer, The pressure is sandwiched between rolls from the optical film side).
As the material of the roll, metal, rubber or the like can be used. The rollers arranged on both sides may be made of the same material or different materials.

<Curing process>
In the curing step, the active energy ray is irradiated to the uncured photocurable adhesive to cure the adhesive layer containing the epoxy compound or the oxetane compound. Thereby, the overlapped polarizer and the optical film are bonded via the photocurable adhesive.
When bonding an optical film to the single side | surface of a polarizer, you may irradiate an active energy ray from either a polarizer side or an optical film side.
Moreover, when bonding an optical film on both surfaces of a polarizer, an active energy ray is applied from either one of the optical films in a state where the optical film is superimposed on both surfaces of the polarizer via a photocurable adhesive. It is advantageous to irradiate and simultaneously cure the photocurable adhesive on both sides.

  As the active energy ray, visible light, ultraviolet ray, X-ray, electron beam or the like can be used, and since it is easy to handle and has a sufficient curing speed, generally, an electron beam or ultraviolet ray is preferably used.

Any appropriate condition can be adopted as the electron beam irradiation condition as long as the adhesive can be cured. For example, in the electron beam irradiation, the acceleration voltage is preferably in the range of 5 to 300 kV, more preferably in the range of 10 to 250 kV. If the acceleration voltage is within the above range, the electron beam reaches the adhesive and can be cured reliably, and the penetrating power through the sample is too strong and the electron beam rebounds, damaging the transparent optical film and the polarizer. There is no risk of giving.
The irradiation dose is in the range of 5 to 100 kGy, more preferably in the range of 10 to 75 kGy. If the irradiation dose is within the above range, the adhesive is sufficiently cured, and the mechanical properties are prevented from lowering or yellowing without damaging the transparent optical film or the polarizer, and the predetermined optical characteristics are obtained. Can be obtained.

Arbitrary appropriate conditions can be employ | adopted for the irradiation conditions of an ultraviolet-ray, if it is the conditions which can cure | harden the said adhesive agent. The dose of ultraviolet rays is preferably in the range of 50~1500mJ / cm ² in accumulated light quantity, and even more preferably in the range of 100 to 500 mJ / cm ^2.

  In the polarizing plate obtained as described above, the thickness of the adhesive layer is not particularly limited, but is usually in the range of 0.01 to 10 μm, and preferably in the range of 0.5 to 5 μm.

[Organic EL display device]
The organic EL display device of the present invention is manufactured by including the above-described circularly polarizing plate of the present invention.

More specifically, the organic EL display device of the present invention includes a circularly polarizing plate using the retardation film of the present invention and an organic EL element. Therefore, the organic EL display device is prevented from being reflected during observation, and the black expression is improved.
The screen size of the organic EL display device is not particularly limited, and can be 20 inches or more.

  FIG. 5 is a schematic explanatory diagram of the configuration of the organic EL display device of the present invention. The configuration of the organic EL display device of the present invention is not limited to that shown in FIG.

  As shown in FIG. 5, a metal electrode 102, a TFT 103, an organic light emitting layer 104, a transparent electrode (ITO etc.) 105, an insulating layer 106, a sealing layer 107, on a transparent substrate 101 made of glass, polyimide, or the like. On the organic EL element B having the film 108 (which may be omitted), the above-described long circularly polarizing plate C having the polarizer 110 sandwiched between the retardation film 109 and the protective film 111 is provided, and the organic EL display device A is provided. Configure.

It is preferable that a cured layer 112 is laminated on the protective film 111.
The hardened layer 112 not only prevents scratches on the surface of the organic EL display device but also has an effect of preventing warpage due to the long circularly polarizing plate.
Further, an antireflection layer 113 may be provided on the cured layer.
The thickness of the organic EL element itself is about 1 μm.

In general, in an organic EL display device, a metal electrode, an organic light emitting layer, and a transparent electrode are sequentially laminated on a transparent substrate to form an element (organic EL element) that is a light emitter.
Here, the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative or the like and a light emitting layer made of a fluorescent organic solid such as anthracene, Or a structure having various combinations such as a laminate of an electron injection layer composed of such a light emitting layer and a perylene derivative, or a laminate of these hole injection layer, light emitting layer, and electron injection layer. Are known.

  In organic EL display devices, holes and electrons are injected into the organic light-emitting layer by applying a voltage to the transparent electrode and the metal electrode, and the energy generated by recombination of these holes and electrons excites the phosphor material. It emits light on the principle that it emits light when the excited fluorescent material returns to the ground state. The mechanism of recombination in the middle is the same as that of a general diode, and as can be predicted from this, the current and the emission intensity show strong nonlinearity with rectification with respect to the applied voltage.

In an organic EL display device, in order to take out light emitted from the organic light emitting layer, at least one of the electrodes needs to be transparent, and is usually a transparent electrode formed of a transparent conductor such as indium tin oxide (ITO). Is preferably used as the anode.
On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a material having a small work function for the cathode, and usually metal electrodes such as Mg—Ag and Al—Li are used.

  The circularly polarizing plate having the retardation film described above can be applied to an organic EL display device having a large screen having a screen size of 20 inches or more, that is, a diagonal distance of 50.8 cm or more.

  In the organic EL display device having such a configuration, the organic light emitting layer is formed of a very thin film having a thickness of about 10 nm. Therefore, the organic light emitting layer transmits light almost completely like the transparent electrode. As a result, light that is incident from the surface of the transparent substrate at the time of non-light emission, passes through the transparent electrode and the organic light emitting layer, and is reflected by the metal electrode is again emitted to the surface side of the transparent substrate. The display surface of the organic EL display device looks like a mirror surface.

  In an organic EL display device including an organic EL element having a transparent electrode on the surface side of an organic light emitting layer that emits light when a voltage is applied and a metal electrode on the back surface side of the organic light emitting layer, the surface side of the transparent electrode (visible) A polarizing plate can be provided on the side), and a retardation plate can be provided between the transparent electrode and the polarizing plate.

Since the retardation film and the polarizing plate have a function of polarizing light incident from the outside and reflected by the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized by the polarization function.
In particular, if the retardation film is composed of a λ / 4 retardation film and the angle formed by the polarization direction of the polarizer and the retardation film is adjusted to 45 ° or 135 °, the mirror surface of the metal electrode is completely shielded. be able to.

  That is, the external light incident on the organic EL display device is transmitted only by the linearly polarized light component by the polarizer, and this linearly polarized light is generally elliptically polarized light by the retardation plate, but the retardation film is particularly λ / 4 retardation. When the angle formed by the polarization direction of the polarizer and the retardation film is 45 ° or 135 °, it becomes circularly polarized light.

  This circularly polarized light is transmitted through the transparent substrate, the transparent electrode, and the organic thin film, is reflected by the metal electrode, is again transmitted through the organic thin film, the transparent electrode, and the transparent substrate, and becomes linearly polarized light again on the retardation film. And since this linearly polarized light is orthogonal to the polarization direction of a polarizing plate, it cannot permeate | transmit a polarizing plate. As a result, the mirror surface of the metal electrode can be completely shielded.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "%" is used in an Example, unless otherwise indicated, "mass%" is represented. Moreover, all the substitution frequencies shown below represent average values.
In addition, cellulose derivatives (a-1) to (a-8), (A-1) to (A-8), (C-1), (C-2) and substituted cellulose derivatives (B-1) shown below. ) To (B-8), (D-1), and (D-2) are represented by the cellulose derivatives (a-1) to (a) shown in Table 1, Table 2, Table 3, and Table 4 described above. -8), (A-1) to (A-8), (C-1), (C-2) and substituted cellulose derivatives (B-1) to (B-8), (D-1), ( An example of D-2) is shown.

１Ｌ四つ口フラスコに、セルロースアセテートａ−１（アセチル基置換度２．８９）５０ｇを入れ、Ｎ−メチルピロリドン（ＮＭＰ）５００ｍＬを加え、室温でかき混ぜて溶解した。炭酸セシウム５７ｇを加え、８時間かき混ぜた。メタノール５００ｍＬと水１Ｌの混合溶液に反応溶液を注入し、析出した固体をろ別した。固体をメタノールで洗浄した後に、５０℃で１２時間乾燥させ、セルロース誘導体（Ａ−１）が４２ｇ得られた。２，３，６位の置換度は^１Ｈ−ＮＭＲから算出した。 Example 1
<Production Example of Cellulose Derivative Having Structure Represented by General Formula (3)>
<< Production Example of Cellulose Derivative (A-1) >>

In a 1 L four-necked flask, 50 g of cellulose acetate a-1 (acetyl group substitution degree 2.89) was added, 500 mL of N-methylpyrrolidone (NMP) was added, and the mixture was stirred and dissolved at room temperature. 57 g of cesium carbonate was added and stirred for 8 hours. The reaction solution was poured into a mixed solution of 500 mL of methanol and 1 L of water, and the precipitated solid was separated by filtration. The solid was washed with methanol and then dried at 50 ° C. for 12 hours to obtain 42 g of a cellulose derivative (A-1). The degree of substitution at positions 2, 3, 6 was calculated from ¹ H-NMR.

１Ｌ四つ口フラスコに、セルロースアセテートａ−２（アセチル基置換度２．６８）５０ｇを入れ、Ｎ−メチルピロリドン（ＮＭＰ）５００ｍＬを加え、室温でかき混ぜて溶解した。フッ化セシウム９５ｇを加え、２４時間かき混ぜた。メタノール５００ｍＬと水１Ｌの混合溶液に反応溶液を注入し、析出した固体をろ別した。固体をメタノールで洗浄した後に、５０℃で１２時間乾燥させ、セルロース誘導体（Ａ−２）が３８ｇ得られた。２，３，６位の置換度は^１Ｈ−ＮＭＲから算出した。 << Production Example of Cellulose Derivative (A-2) >>

In a 1 L four-necked flask, 50 g of cellulose acetate a-2 (acetyl group substitution degree 2.68) was added, 500 mL of N-methylpyrrolidone (NMP) was added, and the mixture was stirred and dissolved at room temperature. 95 g of cesium fluoride was added and stirred for 24 hours. The reaction solution was poured into a mixed solution of 500 mL of methanol and 1 L of water, and the precipitated solid was separated by filtration. The solid was washed with methanol and then dried at 50 ° C. for 12 hours to obtain 38 g of a cellulose derivative (A-2). The degree of substitution at positions 2, 3, 6 was calculated from ¹ H-NMR.

１Ｌ四つ口フラスコに、セルロースアセテートａ−３（アセチル基置換度２．２８）５０ｇを入れ、Ｎ−メチルピロリドン（ＮＭＰ）５００ｍＬを加え、室温でかき混ぜて溶解した。テトラフェニルホウ酸ナトリウム６５ｇを加え、２４時間かき混ぜた。メタノール５００ｍＬと水１Ｌの混合溶液に反応溶液を注入し、析出した固体をろ別した。固体をメタノールで洗浄した後に、５０℃で１２時間乾燥させ、セルロース誘導体（Ａ−３）が３１ｇ得られた。２，３，６位の置換度は^１Ｈ−ＮＭＲから算出した。 << Production Example of Cellulose Derivative (A-3) >>

In a 1 L four-necked flask, 50 g of cellulose acetate a-3 (acetyl group substitution degree 2.28) was added, 500 mL of N-methylpyrrolidone (NMP) was added, and the mixture was stirred and dissolved. 65 g of sodium tetraphenylborate was added and stirred for 24 hours. The reaction solution was poured into a mixed solution of 500 mL of methanol and 1 L of water, and the precipitated solid was separated by filtration. The solid was washed with methanol and then dried at 50 ° C. for 12 hours to obtain 31 g of a cellulose derivative (A-3). The degree of substitution at positions 2, 3, 6 was calculated from ¹ H-NMR.

１Ｌ四つ口フラスコに、セルロースアセテートプロピオネートａ−４（アセチル基置換度１．９８、プロピオニル基置換度０．３７）５０ｇを入れ、Ｎ−メチルピロリドン（ＮＭＰ）５００ｍＬを加え、室温でかき混ぜて溶解した。炭酸セシウム１５ｇを加え６時間かき混ぜた。メタノール５００ｍLと水１Ｌの混合溶液に反応溶液を注入し、析出した固体をろ別した。固体をメタノールで洗浄した後に、５０℃で１２時間乾燥させ、セルロース誘導体（Ａ−４）が１２ｇ得られた。２，３，６位の置換度は^１Ｈ−ＮＭＲから算出した。 << Production Example of Cellulose Derivative (A-4) >>

Into a 1 L four-necked flask, put 50 g of cellulose acetate propionate a-4 (acetyl group substitution degree 1.98, propionyl group substitution degree 0.37), add N-methylpyrrolidone (NMP) 500 mL, and stir at room temperature. And dissolved. 15 g of cesium carbonate was added and stirred for 6 hours. The reaction solution was poured into a mixed solution of 500 mL of methanol and 1 L of water, and the precipitated solid was separated by filtration. The solid was washed with methanol and then dried at 50 ° C. for 12 hours to obtain 12 g of a cellulose derivative (A-4). The degree of substitution at positions 2, 3, 6 was calculated from ¹ H-NMR.

１Ｌ四つ口フラスコに、セルロースアセテートプロピオネートａ−５（アセチル基置換度２．０７、ペンタノイル置換度０．５３）５０ｇを入れ、Ｎ−メチルピロリドン（ＮＭＰ）５００ｍＬを加え、室温でかき混ぜて溶解した。炭酸セシウム３２ｇを加え１０時間かき混ぜた。メタノール５００ｍLと水１Ｌの混合溶液に反応溶液を注入し、析出した固体をろ別した。固体をメタノールで洗浄した後に、５０℃で１２時間乾燥させ、セルロース誘導体（Ａ−５）が２９ｇ得られた。２，３，６位の置換度は^１Ｈ−ＮＭＲから算出した。 << Production Example of Cellulose Derivative (A-5) >>

Into a 1 L four-necked flask, put 50 g of cellulose acetate propionate a-5 (acetyl group substitution degree 2.07, pentanoyl substitution degree 0.53), add N-methylpyrrolidone (NMP) 500 mL, and stir at room temperature. Dissolved. 32 g of cesium carbonate was added and stirred for 10 hours. The reaction solution was poured into a mixed solution of 500 mL of methanol and 1 L of water, and the precipitated solid was separated by filtration. The solid was washed with methanol and then dried at 50 ° C. for 12 hours to obtain 29 g of a cellulose derivative (A-5). The degree of substitution at positions 2, 3, 6 was calculated from ¹ H-NMR.

１Ｌ四つ口フラスコに、セルロースプロピオネートａ−６（プロピオニル基置換度２．３５）５０ｇを入れ、Ｎ−メチルピロリドン（ＮＭＰ）５００ｍＬを加え、室温でかき混ぜて溶解した。炭酸セシウム３２ｇを加え１０時間かき混ぜた。メタノール５００ｍＬと水１Ｌの混合溶液に反応溶液を注入し、析出した固体をろ別した。固体をメタノールで洗浄した後に、５０℃で１２時間乾燥させ、セルロース誘導体（Ａ−６）が３２ｇ得られた。２，３，６位の置換度は^１Ｈ−ＮＭＲから算出した。 << Production Example of Cellulose Derivative (A-6) >>

In a 1 L four-necked flask, 50 g of cellulose propionate a-6 (propionyl group substitution degree 2.35) was added, 500 mL of N-methylpyrrolidone (NMP) was added, and the mixture was dissolved by stirring at room temperature. 32 g of cesium carbonate was added and stirred for 10 hours. The reaction solution was poured into a mixed solution of 500 mL of methanol and 1 L of water, and the precipitated solid was separated by filtration. The solid was washed with methanol and then dried at 50 ° C. for 12 hours to obtain 32 g of a cellulose derivative (A-6). The degree of substitution at positions 2, 3, 6 was calculated from ¹ H-NMR.

１Ｌ四つ口フラスコに、セルロースアセテートメチルエーテルａ−７（アセチル基置換度２．０７、プロピオニル基置換度０．７６）５０ｇを入れ、Ｎ−メチルピロリドン（ＮＭＰ）５００ｍＬを加え、室温でかき混ぜて溶解した。炭酸セシウム５０ｇを加え８時間かき混ぜた。メタノール５００ｍＬと水１Ｌの混合溶液に反応溶液を注入し、析出した固体をろ別した。固体をメタノールで洗浄した後に、５０℃で１２時間乾燥させ、セルロース誘導体（Ａ−７）が４９ｇ得られた。２，３，６位の置換度は^１Ｈ−ＮＭＲから算出した。 << Production Example of Cellulose Derivative (A-7) >>

In a 1 L four-necked flask, put 50 g of cellulose acetate methyl ether a-7 (acetyl group substitution degree 2.07, propionyl group substitution degree 0.76), add N-methylpyrrolidone (NMP) 500 mL, and stir at room temperature. Dissolved. 50 g of cesium carbonate was added and stirred for 8 hours. The reaction solution was poured into a mixed solution of 500 mL of methanol and 1 L of water, and the precipitated solid was separated by filtration. The solid was washed with methanol and then dried at 50 ° C. for 12 hours to obtain 49 g of a cellulose derivative (A-7). The degree of substitution at positions 2, 3, 6 was calculated from ¹ H-NMR.

１Ｌ四つ口フラスコに、セルロースアセテートヒドロキシプロピルエーテルａ−８（アセチル基置換度２．３５、ヒドロキシプロピルエーテル置換度０．４８）ｇを入れ、Ｎ−メチルピロリドン（ＮＭＰ）５００ｍＬを加え、室温でかき混ぜて溶解した。炭酸セシウム４５ｇを加え８時間かき混ぜた。メタノール５００ｍＬと水１Ｌの混合溶液に反応溶液を注入し、析出した固体をろ別した。固体をメタノールで洗浄した後に、５０℃で１２時間乾燥させ、セルロース誘導体Ａ−８が４２ｇ得られた。２，３，６位の置換度は^１Ｈ−ＮＭＲから算出した。 << Production Example of Cellulose Derivative (A-8) >>

Into a 1 L four-necked flask, put cellulose acetate hydroxypropyl ether a-8 (acetyl group substitution degree 2.35, hydroxypropyl ether substitution degree 0.48 g), add N-methylpyrrolidone (NMP) 500 mL, and at room temperature Stir to dissolve. 45 g of cesium carbonate was added and stirred for 8 hours. The reaction solution was poured into a mixed solution of 500 mL of methanol and 1 L of water, and the precipitated solid was separated by filtration. The solid was washed with methanol and then dried at 50 ° C. for 12 hours to obtain 42 g of cellulose derivative A-8. The degree of substitution at positions 2, 3, 6 was calculated from ¹ H-NMR.

１Ｌ四つ口フラスコに、セルロース誘導体（Ａ−１）４２ｇと塩化メチレン４２０ｍＬを加えてかき混ぜた。溶解したところに、塩化ベンゾイル２８ｇを分別添加し、トリエチルアミン３０ｇを入れた。ジメチルアミノピリジン１．０ｇを加え、１５時間かき混ぜた。反応溶液をメタノール１Ｌと水１Ｌの混合溶媒に滴下し、析出した固体をろ別した。得られた固体をメタノール１Ｌ中に分散させ、１時間かき混ぜて再びろ別した。５０℃で１２時間乾燥し、置換セルロース誘導体（Ｂ−１）が５０ｇ得られた。２，３，６位の置換度分布は、^１Ｈ−ＮＭＲ及び^１３Ｃ−ＮＭＲから算出した。 <Production Example of Substituted Cellulose Derivative Having Structure Represented by General Formula (5)>
<< Production Example of Substituted Cellulose Derivative (B-1) >>

To a 1 L four-necked flask, 42 g of cellulose derivative (A-1) and 420 mL of methylene chloride were added and stirred. When dissolved, 28 g of benzoyl chloride was added separately, and 30 g of triethylamine was added. 1.0 g of dimethylaminopyridine was added and stirred for 15 hours. The reaction solution was added dropwise to a mixed solvent of 1 L of methanol and 1 L of water, and the precipitated solid was separated by filtration. The obtained solid was dispersed in 1 L of methanol, stirred for 1 hour and filtered again. It dried at 50 degreeC for 12 hours, and 50g of substituted cellulose derivatives (B-1) were obtained. The substitution degree distributions at the 2, 3, 6 positions were calculated from ¹ H-NMR and ¹³ C-NMR.

１Ｌ四つ口フラスコに、セルロース誘導体（Ａ−２）３８ｇと塩化メチレン３８０ｍＬを加えてかき混ぜた。溶解したところに、塩化ベンゾイル２５ｇを分別添加し、トリエチルアミン２０ｇを入れた。ジメチルアミノピリジン１．０ｇを加え、２０時間かき混ぜた。反応溶液をメタノール１Ｌと水１Ｌの混合溶媒に滴下し、析出した固体をろ別した。得られた固体をメタノール１Ｌ中に分散させ、１時間かき混ぜて再びろ別した。５０℃で１２時間乾燥し、置換セルロース誘導体（Ｂ−２）が４５ｇ得られた。２，３，６位の置換度分布は、^１Ｈ−ＮＭＲ及び^１３Ｃ−ＮＭＲから算出した。 << Production Example of Substituted Cellulose Derivative (B-2) >>

To a 1 L four-necked flask, 38 g of cellulose derivative (A-2) and 380 mL of methylene chloride were added and stirred. When dissolved, 25 g of benzoyl chloride was added separately, and 20 g of triethylamine was added. 1.0 g of dimethylaminopyridine was added and stirred for 20 hours. The reaction solution was added dropwise to a mixed solvent of 1 L of methanol and 1 L of water, and the precipitated solid was separated by filtration. The obtained solid was dispersed in 1 L of methanol, stirred for 1 hour and filtered again. It dried at 50 degreeC for 12 hours, and 45g of substituted cellulose derivatives (B-2) were obtained. The substitution degree distributions at the 2, 3, 6 positions were calculated from ¹ H-NMR and ¹³ C-NMR.

１Ｌ四つ口フラスコに、セルロース誘導体（Ａ−３）３１ｇと塩化メチレン４２０ｍＬを加えてかき混ぜた。溶解したところに、塩化４−メトキシベンゾイル３８ｇを分別添加し、トリエチルアミン２８ｇを入れた。ジメチルアミノピリジン１．０ｇを加え、１２時間かき混ぜた。反応溶液をメタノール１Ｌと水１Ｌの混合溶媒に滴下し、析出した固体をろ別した。得られた固体をメタノール１Ｌ中に分散させ、１時間かき混ぜて再びろ別した。５０℃で１２時間乾燥し、置換セルロース誘導体（Ｂ−３）が４３ｇ得られた。２，３，６位の置換度分布は、^１Ｈ−ＮＭＲ及び^１３Ｃ−ＮＭＲから算出した。 << Production Example of Substituted Cellulose Derivative (B-3) >>

To a 1 L four-necked flask, 31 g of cellulose derivative (A-3) and 420 mL of methylene chloride were added and stirred. When dissolved, 38 g of 4-methoxybenzoyl chloride was added separately, and 28 g of triethylamine was added. 1.0 g of dimethylaminopyridine was added and stirred for 12 hours. The reaction solution was added dropwise to a mixed solvent of 1 L of methanol and 1 L of water, and the precipitated solid was separated by filtration. The obtained solid was dispersed in 1 L of methanol, stirred for 1 hour and filtered again. It dried at 50 degreeC for 12 hours, and 43g of substituted cellulose derivatives (B-3) were obtained. The substitution degree distributions at the 2, 3, 6 positions were calculated from ¹ H-NMR and ¹³ C-NMR.

１Ｌ四つ口フラスコに、セルロース誘導体（Ａ−４）１２ｇと塩化メチレン１２０ｍＬを加えてかき混ぜた。溶解したところに、塩化ベンゾイル１１ｇを分別添加し、トリエチルアミン１０ｇを入れた。ジメチルアミノピリジン１．０ｇを加え、２４時間かき混ぜた。反応溶液をメタノール１Ｌと水１Ｌの混合溶媒に滴下し、析出した固体をろ別した。得られた固体をメタノール１Ｌ中に分散させ、１時間かき混ぜて再びろ別した。５０℃で１２時間乾燥し、置換セルロース誘導（Ｂ−４）が３０ｇ得られた。２，３，６位の置換度分布は、^１Ｈ−ＮＭＲ及び^１３Ｃ−ＮＭＲから算出した。 << Production Example of Substituted Cellulose Derivative (B-4) >>

To a 1 L four-necked flask, 12 g of cellulose derivative (A-4) and 120 mL of methylene chloride were added and stirred. When dissolved, 11 g of benzoyl chloride was added separately, and 10 g of triethylamine was added. 1.0 g of dimethylaminopyridine was added and stirred for 24 hours. The reaction solution was added dropwise to a mixed solvent of 1 L of methanol and 1 L of water, and the precipitated solid was separated by filtration. The obtained solid was dispersed in 1 L of methanol, stirred for 1 hour and filtered again. After drying at 50 ° C. for 12 hours, 30 g of substituted cellulose derivative (B-4) was obtained. The substitution degree distributions at the 2, 3, 6 positions were calculated from ¹ H-NMR and ¹³ C-NMR.

１Ｌ四つ口フラスコに、セルロース誘導体（Ａ−５）２９ｇと塩化メチレン２９０ｍＬを加えてかき混ぜた。溶解したところに、塩化ベンゾイル１８ｇを分別添加し、トリエチルアミン１５ｇを入れた。ジメチルアミノピリジン１．０ｇを加え、１２時間かき混ぜた。反応溶液をメタノール１Ｌと水１Ｌの混合溶媒に滴下し、析出した固体をろ別した。得られた固体をメタノール１Ｌ中に分散させ、１時間かき混ぜて再びろ別した。５０℃で１２時間乾燥し、置換セルロース誘導体（Ｂ−５）が３９ｇ得られた。２，３，６位の置換度分布は、^１Ｈ−ＮＭＲ及び^１３Ｃ−ＮＭＲから算出した。 << Production Example of Substituted Cellulose Derivative (B-5) >>

In a 1 L four-necked flask, 29 g of cellulose derivative (A-5) and 290 mL of methylene chloride were added and stirred. When dissolved, 18 g of benzoyl chloride was added separately, and 15 g of triethylamine was added. 1.0 g of dimethylaminopyridine was added and stirred for 12 hours. The reaction solution was added dropwise to a mixed solvent of 1 L of methanol and 1 L of water, and the precipitated solid was separated by filtration. The obtained solid was dispersed in 1 L of methanol, stirred for 1 hour and filtered again. It dried at 50 degreeC for 12 hours, and 39g of substituted cellulose derivatives (B-5) were obtained. The substitution degree distributions at the 2, 3, 6 positions were calculated from ¹ H-NMR and ¹³ C-NMR.

１Ｌ四つ口フラスコに、セルロース誘導体（Ａ−６）３２ｇと塩化メチレン２９０ｍＬを加えてかき混ぜた。溶解したところに、２−チオフェンカルボニルクロリド１２ｇを分別添加し、トリエチルアミン１５ｇを入れた。ジメチルアミノピリジン１．０ｇを加え、２０時間かき混ぜた。反応溶液をメタノール１Ｌと水１Ｌの混合溶媒に滴下し、析出した固体をろ別した。得られた固体をメタノール１Ｌ中に分散させ、１時間かき混ぜて再びろ別した。５０℃で１２時間乾燥し、置換セルロース誘導体（Ｂ−６）が３５ｇ得られた。２，３，６位の置換度分布は、^１Ｈ−ＮＭＲ及び^１３Ｃ−ＮＭＲから算出した。 << Production Example of Substituted Cellulose Derivative (B-6) >>

To a 1 L four-necked flask, 32 g of cellulose derivative (A-6) and 290 mL of methylene chloride were added and stirred. When dissolved, 12 g of 2-thiophenecarbonyl chloride was added separately, and 15 g of triethylamine was added. 1.0 g of dimethylaminopyridine was added and stirred for 20 hours. The reaction solution was added dropwise to a mixed solvent of 1 L of methanol and 1 L of water, and the precipitated solid was separated by filtration. The obtained solid was dispersed in 1 L of methanol, stirred for 1 hour and filtered again. It dried at 50 degreeC for 12 hours, and 35g of substituted cellulose derivatives (B-6) were obtained. The substitution degree distributions at the 2, 3, 6 positions were calculated from ¹ H-NMR and ¹³ C-NMR.

１Ｌ四つ口フラスコに、セルロース誘導体（Ａ−７）４９ｇと塩化メチレン４９０ｍＬを加えてかき混ぜた。溶解したところに、無水安息香酸４８ｇを分別添加し、トリエチルアミン２０ｇを入れた。ジメチルアミノピリジン１．０ｇを加え、１５時間かき混ぜた。反応溶液をメタノール１Ｌと水１Ｌの混合溶媒に滴下し、析出した固体をろ別した。得られた固体をメタノール１Ｌ中に分散させ、１時間かき混ぜて再びろ別した。５０℃で１２時間乾燥し、置換セルロース誘導体（Ｂ−７）が５３ｇ得られた。２，３，６位の置換度分布は、^１Ｈ−ＮＭＲ及び^１３Ｃ−ＮＭＲから算出した。 << Production Example of Substituted Cellulose Derivative (B-7) >>

To a 1 L four-necked flask, 49 g of cellulose derivative (A-7) and 490 mL of methylene chloride were added and stirred. When dissolved, 48 g of benzoic anhydride was added separately, and 20 g of triethylamine was added. 1.0 g of dimethylaminopyridine was added and stirred for 15 hours. The reaction solution was added dropwise to a mixed solvent of 1 L of methanol and 1 L of water, and the precipitated solid was separated by filtration. The obtained solid was dispersed in 1 L of methanol, stirred for 1 hour and filtered again. It dried at 50 degreeC for 12 hours, and 53g of substituted cellulose derivatives (B-7) were obtained. The substitution degree distributions at the 2, 3, 6 positions were calculated from ¹ H-NMR and ¹³ C-NMR.

１Ｌ四つ口フラスコに、セルロース誘導体（Ａ−８）４２ｇと塩化メチレン４２０ｍＬを加えてかき混ぜた。溶解したところに、塩化ベンゾイル２８ｇを分別添加し、トリエチルアミン２０ｇを入れた。ジメチルアミノピリジン１．０ｇを加え、１５時間かき混ぜた。反応溶液をメタノール１Ｌと水１Ｌの混合溶媒に滴下し、析出した固体をろ別した。得られた固体をメタノール１Ｌ中に分散させ、１時間かき混ぜて再びろ別した。５０℃で１２時間乾燥し、置換セルロース誘導体（Ｂ−８）が５２ｇ得られた。２，３，６位の置換度分布は、^１Ｈ−ＮＭＲ及び^１３Ｃ−ＮＭＲから算出した。 << Production Example of Substituted Cellulose Derivative (B-8) >>

To a 1 L four-necked flask, 42 g of cellulose derivative (A-8) and 420 mL of methylene chloride were added and stirred. When dissolved, 28 g of benzoyl chloride was added separately, and 20 g of triethylamine was added. 1.0 g of dimethylaminopyridine was added and stirred for 15 hours. The reaction solution was added dropwise to a mixed solvent of 1 L of methanol and 1 L of water, and the precipitated solid was separated by filtration. The obtained solid was dispersed in 1 L of methanol, stirred for 1 hour and filtered again. It dried at 50 degreeC for 12 hours, and 52g of substituted cellulose derivatives (B-8) were obtained. The substitution degree distributions at the 2, 3, 6 positions were calculated from ¹ H-NMR and ¹³ C-NMR.

<Example of production of optical films 1-8>
Optical films 1-8 were produced using the substituted cellulose derivatives (B-1) to (B-8) produced above.
<< Production Example of Optical Film 1 >>
(Fine particle dispersion 1)
Fine particles (Aerosil R972V manufactured by Nippon Aerosil Co., Ltd.) 11 parts by weight Ethanol 89 parts by weight The above was stirred and mixed with a dissolver for 50 minutes, and then dispersed with Manton Gorin to prepare a fine particle dispersion 1.

(Fine particle addition liquid 1)
The fine particle dispersion 1 was slowly added to the dissolution tank containing methylene chloride with sufficient stirring. Furthermore, dispersion was carried out with an attritor. This was filtered with Finemet NF manufactured by Nippon Seisen Co., Ltd. to prepare a fine particle additive solution 1.
99 parts by mass of methylene chloride 5 parts by mass of fine particle dispersion 1

(Preparation of dope)
A dope having the following composition was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. Cellulose ester A was added to a pressurized dissolution tank containing a solvent while stirring. This was heated and stirred to dissolve completely, and this was dissolved in Azumi Filter Paper No. The dope was prepared by filtration using 244.

(Composition of dope)
Methylene chloride 340 parts by weight Ethanol 64 parts by weight Substituted cellulose derivative 1 100 parts by weight Monopet SB (Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by weight Particulate additive liquid 1 1 part by weight

Then, using an endless belt casting apparatus, the dope was cast uniformly on a stainless steel belt support at a temperature of 33 ° C. and a width of 1500 mm. The temperature of the stainless steel belt was controlled at 30 ° C.
On the stainless steel belt support, the solvent was evaporated until the residual solvent amount in the cast (cast) film was 75%, and then peeled off from the stainless steel belt support with a peeling tension of 130 N / m.
The peeled optical film was stretched 30% (1.30 times) in the width direction using a tenter while applying heat at 145 ° C. The residual solvent at the start of stretching was 14%.
Next, drying was terminated while the drying zone was conveyed by a number of rolls. Drying temperature is 1
At 30 ° C., the transport tension was 100 N / m.
As described above, an optical film 1 having a dry film thickness of 20 μm was obtained.

≪Examples of production of optical films 2-8≫
Optical films 1 to 8 were produced in the same manner except that the type of the substituted cellulose derivative was changed as shown in Table 5 in the production of the optical film 1.

<Example of production of optical films 9 and 10>
Cellulose derivatives (C-1), (C-2) and substituted cellulose derivatives (D-1) used in the production of optical films 9 and 10, types of substituents, substitution positions and substitution degrees of (D-2), etc. Is as shown in Table 3 and Table 4 below.

１Ｌ四つ口フラスコに、セルロースアセテートａ−１（アセチル基置換度２．８９）５０ｇを入れ、アセトン５００ｍＬを加え、室温でかき混ぜて溶解した。硫酸６ｍＬを加え、６時間かき混ぜた。メタノール２００ｍＬとクエン酸リン酸緩衝液１Ｌの混合溶液に反応溶液を注入し、析出した固体をろ別した。固体をメタノールと水で洗浄した後に、５０℃で１２時間乾燥させ、セルロース誘導体（Ｃ−１）が２９ｇ得られた。２，３，６位の置換度は^１Ｈ−ＮＭＲから算出した。２，３位アセチル基よりも６位アセチル基が多く加水分解され、また、分子量も減少した。 << Production Example of Cellulose Derivative (C-1) >>

In a 1 L four-necked flask, 50 g of cellulose acetate a-1 (acetyl group substitution degree 2.89) was added, 500 mL of acetone was added, and the mixture was dissolved by stirring at room temperature. 6 mL of sulfuric acid was added and stirred for 6 hours. The reaction solution was poured into a mixed solution of 200 mL of methanol and 1 L of citrate phosphate buffer, and the precipitated solid was separated by filtration. The solid was washed with methanol and water and then dried at 50 ° C. for 12 hours to obtain 29 g of a cellulose derivative (C-1). The degree of substitution at positions 2, 3, 6 was calculated from ¹ H-NMR. The 6-position acetyl group was hydrolyzed more than the 2- and 3-position acetyl groups, and the molecular weight decreased.

１Ｌ四つ口フラスコに、セルロースアセテートａ−１（アセチル基置換度２．８９）５０ｇを入れ、アセトン５００ｍＬを加え、室温でかき混ぜて溶解した。炭酸カリウム１３ｇを加え、６時間かき混ぜた。メタノール２００ｍＬとクエン酸リン酸緩衝液１Ｌの混合溶液に反応溶液を注入し、析出した固体をろ別した。固体をメタノールと水で洗浄した後に、５０℃で１２時間乾燥させ、セルロース誘導体（Ｃ−２）が３３ｇ得られた。２，３，６位の置換度は^１Ｈ−ＮＭＲから算出した。２，３位アセチル基よりも６位アセチル基が多く加水分解された。 << Production Example of Cellulose Derivative (C-2) >>

In a 1 L four-necked flask, 50 g of cellulose acetate a-1 (acetyl group substitution degree 2.89) was added, 500 mL of acetone was added, and the mixture was dissolved by stirring at room temperature. 13 g of potassium carbonate was added and stirred for 6 hours. The reaction solution was poured into a mixed solution of 200 mL of methanol and 1 L of citrate phosphate buffer, and the precipitated solid was separated by filtration. The solid was washed with methanol and water, and then dried at 50 ° C. for 12 hours to obtain 33 g of a cellulose derivative (C-2). The degree of substitution at positions 2, 3, 6 was calculated from ¹ H-NMR. The 6-position acetyl group was hydrolyzed more than the 2- and 3-position acetyl groups.

１Ｌ四つ口フラスコに、セルロース誘導体（Ｃ−１）（重量平均分子量８５００）１５ｇと塩化メチレン１５０ｍＬを加えてかき混ぜた。溶解したところに、塩化ベンゾイル１２ｇを分別添加し、トリエチルアミン１０ｇを入れた。ジメチルアミノピリジン１．０ｇを加え、２４時間かき混ぜた。反応溶液をメタノール１Ｌと水１Ｌの混合溶媒に滴下し、析出した固体をろ別した。得られた固体をメタノール１Ｌ中に分散させ、１時間かき混ぜて再びろ別した。５０℃で１２時間乾燥し、置換セルロース誘導体（Ｄ−１）が３２ｇ得られた。２，３，６位の置換度分布は、^１Ｈ−ＮＭＲ及び^１３Ｃ−ＮＭＲから算出した。 << Production Example of Substituted Cellulose Derivative (D-1) >>

To a 1 L four-necked flask, 15 g of cellulose derivative (C-1) (weight average molecular weight 8500) and 150 mL of methylene chloride were added and stirred. When dissolved, 12 g of benzoyl chloride was added separately, and 10 g of triethylamine was added. 1.0 g of dimethylaminopyridine was added and stirred for 24 hours. The reaction solution was added dropwise to a mixed solvent of 1 L of methanol and 1 L of water, and the precipitated solid was separated by filtration. The obtained solid was dispersed in 1 L of methanol, stirred for 1 hour and filtered again. It dried at 50 degreeC for 12 hours, and 32g of substituted cellulose derivatives (D-1) were obtained. The substitution degree distributions at the 2, 3, 6 positions were calculated from ¹ H-NMR and ¹³ C-NMR.

１Ｌ四つ口フラスコに、セルロース誘導体（Ｃ−２）３３ｇと塩化メチレン３３０ｍＬを加えてかき混ぜた。溶解したところに、２−チオフェンカルボニルクロリド１５ｇを分別添加し、トリエチルアミン１０ｇを入れた。ジメチルアミノピリジン１．０ｇを加え、１２時間かき混ぜた。反応溶液をメタノール１Ｌと水１Ｌの混合溶媒に滴下し、析出した固体をろ別した。得られた固体をメタノール１Ｌ中に分散させ、１時間かき混ぜて再びろ別した。５０℃で１２時間乾燥し、置換セルロース誘導体（Ｄ−２）が３２ｇ得られた。２，３，６位の置換度分布は、^１Ｈ−ＮＭＲ及び^１３Ｃ−ＮＭＲから算出した。 << Production Example of Substituted Cellulose Derivative (D-2) >>

To a 1 L four-necked flask, 33 g of cellulose derivative (C-2) and 330 mL of methylene chloride were added and stirred. When dissolved, 15 g of 2-thiophenecarbonyl chloride was added separately, and 10 g of triethylamine was added. 1.0 g of dimethylaminopyridine was added and stirred for 12 hours. The reaction solution was added dropwise to a mixed solvent of 1 L of methanol and 1 L of water, and the precipitated solid was separated by filtration. The obtained solid was dispersed in 1 L of methanol, stirred for 1 hour and filtered again. It dried at 50 degreeC for 12 hours, and 32g of substituted cellulose derivatives (D-2) were obtained. The substitution degree distributions at the 2, 3, 6 positions were calculated from ¹ H-NMR and ¹³ C-NMR.

<< Examples of production of optical films 9 and 10 >>
Optical films 9 and 10 were produced in the same manner as in the production of the optical film 1 except that the type of the substituted cellulose derivative was changed to the substituted cellulose derivatives (D-1) and (D-2).

<Evaluation>
≪Dope solubility≫
The solubility of the dope obtained in “(Preparation of dope)” was visually confirmed.
Evaluation was performed according to the following criteria. The results obtained are shown in Table 5.
A: Completely dissolved and clear B: Completely dissolved C: Partially insoluble component D: Insoluble

≪Phase difference≫
The retardation value of the center part in the width direction of the obtained optical film at a wavelength of 550 nm was measured. For measurement, automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Co., Ltd.) is used to adjust the humidity for 2 hours in an environment of 23 ° C. and 55% RH, and measure the three-dimensional birefringence at a measurement wavelength of 590 nm. And the measured value was substituted into the following equation to obtain the retardation value at a film thickness of 50 μm. The results obtained are shown in Table 5.
Of formula (I): in-plane retardation _{R 0 = (n x -n y} ) × d
In the formula, d is the film thickness (nm), refractive index _nx (the maximum refractive index in the plane of the film, also referred to as the refractive index in the slow axis direction), _ny (with the slow axis in the film plane). Refractive index in the direction perpendicular to
“Phase difference nm / 50 μm” shown in Table 5 is a phase difference value per 50 μm of film thickness.

<< Wavelength dispersion >>
The retardation value of the center part of the width direction of the obtained optical film was measured. For measurement, automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments Co., Ltd.) was used to adjust the humidity for 2 hours in an environment of 23 ° C. and 55% RH, and three-dimensional birefringence at wavelengths of 450 and 630 nm. A rate measurement was performed, and the value of R ₀ was obtained by substituting the measured value into the formula (I). The obtained _R0 was substituted into the following formula (II) to obtain wavelength dispersion (DSP). This value is preferably 1.10 or less. The results obtained are shown in Table 5.
Formula (II): wavelength dispersion = R ₀ (450 nm) / R ₀ (630 nm)

≪Moisture heat dimension fluctuation≫
About the obtained optical film, two test pieces of 30 mm width × 120 mm length (casting direction) are collected. Holes with a diameter of 6 mm are punched at both ends in the length direction of the test piece with a 100 mm interval. After adjusting the humidity in an environment of 25 ° C. and 60% RH, the dimension of the punch interval before heat treatment was measured using an automatic pin cage (manufactured by Shinto Kagaku Co., Ltd.). Next, after putting each test piece in a thermo-hygrostat at 80 ° C. and 90% RH for 1000 hours, the test piece is left in a room at 25 ° C. and 60% RH for 2 hours. The dimensions were measured.
Dimensional shrinkage X (%) = [(Dimension before heat treatment−Dimension after heat treatment) / Dimension before heat treatment] × 100
Evaluation was performed according to the following criteria. The results obtained are shown in Table 5.
○: 0 ≦ X ≦ 1.0
Δ: 1.0 <X ≦ 1.5
×: 1.5 <X

  From the results shown in Table 5, the optical films 1 to 8 are superior to the optical films 9 and 10 in terms of dope solubility, retardation characteristics, wavelength dispersibility (DSP), and wet heat dimensional variation. It is recognized that

Example 2
<Production of Circular Polarizing Plate> A 120 μm thick polyvinyl alcohol film was uniaxially stretched (temperature 110 ° C., stretch ratio 5 times). This was immersed in an aqueous solution composed of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 ° C. composed of 6 g of potassium iodide, 7.5 g of boric acid and 100 g of water. This was washed with water and dried to obtain a polarizer.

  Bonding was performed using an adhesive so that the slow axis of each optical film produced in Example 1 and the absorption axis of the polarizer were 45 °, and a protective film (Konica Minolta) was attached to the back side of the polarizer. Tack KC4UY, thickness 40 μm, manufactured by Konica Minolta Co., Ltd.) were bonded together with water paste to produce circularly polarizing plates 1 to 10.

<Production of organic EL cell>
According to the method described in the example of JP 2010-20925 A using a 3 mm-thick 50 inch (127 cm) non-alkali glass, it was described in FIG. 8 of JP 2010-20925 A An organic EL cell having a configuration was produced.

<Production of organic EL display device>
After apply | coating an adhesive agent on the surface of the phase difference film of each circularly-polarizing plate produced above, the organic EL image display apparatuses 1-10 were produced by bonding on the visual recognition side of an organic EL cell.

<Evaluation of organic EL display device>
As a result of evaluating basic display characteristics such as black color characteristics and reflectivity (visibility) in accordance with a conventional method, the organic EL display apparatus using the optical film of the present invention. 1 to 8 could confirm that good characteristics were obtained.

11 Stretching direction 13 Conveying direction 14 Slow axis D1 Feeding direction D2 Winding direction F Optical film θi Bending angle (feeding angle)
Ci, Co Grip Ri, Ro Rail Wo Width of film before stretching W Width of film after stretching 16 Film feeding device 17 Transport direction changing device 18 Winding device 19 Film forming device A Organic electroluminescence display device B Organic electroluminescence Element C Circularly polarizing plate 101 Transparent substrate 102 Metal electrode 103 TFT
DESCRIPTION OF SYMBOLS 104 Organic light emitting layer 105 Transparent electrode 106 Insulating layer 107 Sealing layer 108 Film 109 (lambda) / 4 phase difference film 110 Polarizer 111 Protective film 112 Hardened layer 113 Antireflection layer

Claims (10)

The structure represented by the following general formula (3) is obtained by hydrolyzing the compound having the structure represented by the following general formula (2) in the presence of the compound having the structure represented by the following general formula (1). A method for producing a cellulose derivative, which comprises obtaining a cellulose derivative having
General formula (1): (W) _m (Y) _n
[Wherein, W represents an ion having an ionic radius in the range of 1.5 to 2.0 Å. Y represents a counter ion. m and n each independently represent an integer of 1 or more. ]

[Wherein, R ₂₀ , R ₃₀ and R ₆₀ each independently represents a hydrogen atom, an aliphatic group or an aromatic group. L ₂₀ , L ₃₀ and L ₆₀ are each a divalent group formed from one or more groups independently selected from the group consisting of a single bond, —O—, —CO— or — (Lw—O) q—. Represents a linking group. Lw represents an alkylene group. q represents an integer of 0 to 10. p0 represents an average degree of polymerization and represents an integer of 10 to 2000. ]

[Wherein R ₂ , R ₃ and R ₆ each independently represent a hydrogen atom, an aliphatic group or an aromatic group. L ₂ , L ₃ and L ₆ are each independently a divalent group formed from one or more groups selected from the group consisting of a single bond, —O—, —CO— or — (Lw—O) q—. Represents a linking group. Lw represents an alkylene group. q represents an integer of 0 to 10. p represents an average degree of polymerization and represents an integer of 10 to 2000.
_However, -L ₂ -R 2, degree of substitution with _-L 3 -R ₃ and _-L 6 -R ₆ satisfies the following formula (a) and the following formula (b).
Formula (a): (Substitution degree by -L ₂ -R ₂ ) <(Substitution degree by -L ₆ -R ₆ )
Formula (b): (Substitution degree by -L ₃ -R ₃ ) <(Substitution degree by -L ₆ -R ₆ )
The degree of substitution with -L ₂ -R ₂ , -L ₃ -R ₃ and -L ₆ -R ₆ refers to the bonding to three carbon atoms at the 2nd, 3rd and 6th positions relative to the anhydroglucose unit. It is a numerical value showing how many of the hydroxy groups on average are substituted with hydrogen atoms. ]   In the said General formula (1), the ion represented by W is a cesium ion, The manufacturing method of the cellulose derivative of Claim 1 characterized by the above-mentioned.   The method for producing a cellulose derivative according to claim 1 or 2, wherein the compound having a structure represented by the general formula (1) is cesium carbonate. In the general formula (2), R ₂₀ , R ₃₀ and R ₆₀ are each a hydrogen atom or a methyl group,
In the said General formula (3), R < ₂ >, R < ₃ > and R < ₆ > are respectively a hydrogen atom or a methyl group, The cellulose derivative as described in any one of Claim 1- Claim 3 characterized by the above-mentioned. Manufacturing method. By reacting a cellulose derivative having a structure represented by the general formula (3) with a compound having a structure represented by the following general formula (4a), general formula (4b) or general formula (4c), The manufacturing method of the substituted cellulose derivative characterized by obtaining the substituted cellulose derivative which has a structure represented by following General formula (5).
General formula (4a): Rv- (L) q-X
[Wherein Rv represents an aliphatic group or an aromatic group. L represents a carbonyl group. q represents 0 or 1; X represents a halogen atom. ]
Formula (4b): (Rv-L) ₂ O
[Wherein Rv represents an aliphatic group or an aromatic group. L represents a carbonyl group. ]
General formula (4c): Rv-N = C = Z
[Wherein Rv represents an aliphatic group or an aromatic group. Z represents an oxygen atom or a sulfur atom. ]

[Wherein, R ₂₁ , R ₃₁ and R ₆₁ each independently represents a hydrogen atom, an aliphatic group or an aromatic group. However, at least one of R ₂₁ , R ₃₁ and R ₆₁ is Rv derived from a compound having a structure represented by the general formula (4a), the general formula (4b) or the general formula (4c). is there. L ₂₁ , L ₃₁ and L ₆₁ are each independently formed from one or more groups selected from the group consisting of a single bond, —O—, —CO—, —NHCO or — (Lw—O) q—. Represents a divalent linking group. Lw represents an alkylene group. q represents an integer of 0 to 10. p1 represents an average degree of polymerization and represents an integer of 10 to 2000.
In addition, when at least one of R ₂₁ , R ₃₁ and R ₆₁ is Rv, the degree of substitution with -L ₂₁ -Rv, -L ₃₁ -Rv and -L ₆₁ -Rv is represented by the following formula (c) and The following formula (d) is satisfied.
Formula (c): (Substitution degree by -L ₆₁ -Rv) <(Substitution degree by -L ₂₁ -Rv)
Formula _{(d): (-} L 61 degree of substitution -Rv) _<(- degree of substitution by L 31 -Rv)
-L _{21 -Rv,} and the degree of substitution by _-L 31 -Rv and _-L 61 -Rv, against anhydroglucose unit, 2-position, 3-position and 6-position three hydroxy groups attached to a carbon atom Among these, on average, this is a numerical value representing how many hydrogen atoms are substituted with substituents. ]   6. The method for producing a substituted cellulose derivative according to claim 5, wherein Rv is an aromatic group in the compound having a structure represented by the general formula (4a) to the general formula (4c).   An optical film comprising a substituted cellulose derivative produced by the method for producing a substituted cellulose derivative according to claim 5 or 6.   The optical film according to claim 7, wherein the optical film is a long film and has a slow axis in a range of 40 to 50 ° with respect to the longitudinal direction.   A circularly polarizing plate, wherein the optical film according to claim 7 or 8 and a polarizer are bonded.   An organic electroluminescence display device comprising the circularly polarizing plate according to claim 9.

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