JPWO2016060144A1 - Polymer composition, optical film, circularly polarizing plate and display device - Google Patents

Abstract

An object of the present invention is to provide a polymer composition capable of forming a high-order structure by allowing a compound having a predetermined structure to coexist with an aromatic or aliphatic carbamate substituted polymer. The polymer composition of the present invention is a polymer composition containing a polymer having a repeating unit, the polymer having a hydroxy group and a carbamate group, and having an asymmetric carbon in the repeating unit. An aromatic or aliphatic carbamate substituted polymer, further comprising a compound having a structure represented by the general formula (1), wherein the content of the compound is the aromatic or aliphatic carbamate substituted polymer It is characterized by being in the range of 0.005 to 20% by mass with respect to.

Description

  The present invention relates to a polymer composition, an optical film, a circularly polarizing plate, and a display device. More specifically, the present invention relates to a polymer composition that can form a high-order higher-order structure.

Synthetic polymers are widely used in all industries, but only a few polymers, such as polyester and polyvinyl chloride, are widely used from the pursuit of productivity and have excellent performance. Polyethersulfone (PES), aramid, etc. are only used for a few special purposes.
A major problem with general-purpose synthetic polymers is heat resistance. At present, there is no known synthetic polymer that is excellent in heat resistance and economical in production and cost.
Synthetic polymers design and manufacture polymers having desired performance by designing the structure of the monomers or combining various monomers. However, it is very difficult to control the higher-order structure of the synthetic polymer only by the combination of the monomers. In order to develop a new function by controlling the higher-order structure, it is necessary to use modern technology. Even enormous costs and precise manufacturing facilities are required.

On the other hand, many natural polymers have high heat resistance, and when they exist in large quantities in nature, the production cost is very low, and advanced production equipment is not required. Moreover, the structure is originally controlled when it exists in nature. In particular, a natural polymer having chirality has a high-order structure.
Polymers with a controlled higher order structure can add various properties, and natural polymers are very useful especially in applications utilizing the anisotropy of polymers such as optical films. . In addition, when an interaction such as a hydrogen bond is formed in a polymer or between polymers, a higher-order structure is immobilized, so that a more excellent function can be imparted (for example, non-patent Reference 1).

In the case of using a natural polymer as a film, a method for introducing a substituent has been known for the purpose of expressing the required performance. In particular, many films are used because acyl groups can form hydrogen bonds and the introduction reaction of acyl groups into natural polymers is easy. As with acyl groups, carbamate groups are relatively easy to introduce into natural polymers, but films incorporating carbamate groups are not widely used compared to acyl group-substituted films.
Although there are reports of substituted cellulose films in a range where the degree of carbamate substitution is limited when used as an optical film (see, for example, Patent Document 1), in a film composed only of a carbamate-substituted cellulose resin, the carbamate linking moiety is acyl. It was found that the orientation was inferior because the distance was longer than that of the connecting portion and it was easy to freely rotate, and the desired performance was not actually obtained. In addition, no technique for improving the orientation of the carbamate group has been reported so far.

JP 2010-235757 A

C. Yamamoto, et. al. , Journal of Polymer Science Part A, 2006, 5087-5098.

  The present invention has been made in view of the above-described problems and situations, and the solution to the problem is that a compound having a predetermined structure coexists in an aromatic or aliphatic carbamate-substituted polymer, thereby achieving a highly advanced higher-order structure. It is to provide a polymer composition capable of forming Furthermore, by using the polymer composition, an optical film, a circularly polarizing plate, and a display device that exhibit excellent reverse wavelength dispersion and a retardation of λ / 4, and have small fluctuations in retardation due to humidity and heat. Is to provide.

In order to solve the above problems, the present inventor, in the process of studying the cause of the above problems, in order to design a high value-added polymer, in addition to the interaction within the polymer and the interaction between the polymers As a result of intensive investigations on means capable of controlling the higher-order structure of the polymer, it was found that the substituents in the polymer are specifically highly oriented when a low-molecular compound having a certain functional group coexists.
Furthermore, as a result of verifying the effects of various low molecular weight compounds, it was discovered that the derivative derived from the raw material remaining when a substituent was introduced into the polymer had an effect on the orientation of the polymer. Invented.
That is, the said subject which concerns on this invention is solved by the following means.

1. A polymer composition containing a polymer having a repeating unit,
The polymer is an aromatic or aliphatic carbamate substituted polymer having a hydroxy group and a carbamate group and having an asymmetric carbon in the repeating unit;
Furthermore, it contains a compound having a structure represented by the following general formula (1), and
Content of the said compound exists in the range of 0.005-20 mass% with respect to the said aromatic or aliphatic carbamate substituted polymer, The polymer composition characterized by the above-mentioned.
General formula (1)
(Ra—O—) _m1 —CO— (NH—Rn) _m2
(In the formula, Ra represents a hydrogen atom or an aliphatic group. Rn represents an aromatic group or an aliphatic group. When m1 represents 0, m2 represents 2. When m1 represents 1, m2 represents m2. Represents 1)

  2. 2. The polymer composition according to item 1, wherein the aromatic or aliphatic carbamate substituted polymer has a structure represented by the following general formula (2).

(Wherein R ₂ , R ₃ and R ₆ each independently represents a hydrogen atom, an aliphatic group or an aromatic group. L ₂ , L ₃ and L ₆ each independently represents a single bond, —CO -, -CO-NH- and-(Lw-O) q- represents a divalent linking group formed from one or more groups selected from the group consisting of:-Lw represents an alkylene group, q is Represents an integer of 1 to 10. p represents an average degree of polymerization and represents an integer of 10 to 2000.)

3. In the aromatic or aliphatic carbamate substituted polymer having the structure represented by the general formula (2),
_-L 2 _-R 2 in glucose units, _-L 3 -R ₃ and _-L 6 -R ₆ is, represents a -CO-NH-Rc independently if Rc represents an aromatic group or an aliphatic group The average value of the degree of substitution of —H ₂ —R ₂ , —L ₃ —R ₃ and —L ₆ —R ₆ of the hydrogen atom of the hydroxy group at the 2nd, 3rd and 6th positions is represented by the following formula (a): 3. The polymer composition according to item 2, wherein
Formula (a):
0.00 <{(substitution degree with -L ₂ -R ₂ ) + (substitution degree with -L ₃ -R ₃ ) + (substitution degree with -L ₆ -R ₆ )} ≦ 2.50

  4). The content of the compound having the structure represented by the general formula (1) is 0.01 to 5 mass with respect to the aromatic or aliphatic carbamate substituted polymer having the structure represented by the general formula (2). The polymer composition according to any one of items 1 to 3, wherein the polymer composition is in the range of%.

  5. An optical film comprising the polymer composition according to any one of items 1 to 4.

  6). 6. The optical film according to item 5, which is a long film and has a slow axis within a range of 40 to 50 ° with respect to the longitudinal direction.

  7). A circularly polarizing plate, wherein the optical film according to Item 5 or 6 and a polarizer are bonded.

  8). A display device comprising the optical film according to item 5 or 6.

  By the above-mentioned means of the present invention, a polymer composition capable of forming a high-order structure can be provided by allowing a compound having a predetermined structure to coexist with an aromatic or aliphatic carbamate-substituted polymer. . Furthermore, by using the polymer composition, an optical film, a circularly polarizing plate, and a display device that exhibit excellent reverse wavelength dispersion and a phase difference of λ / 4, and that have a small phase difference variation due to humidity and heat. Can be provided.

The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
In a polymer having an asymmetric carbon in a repeating unit, the positions of substituents around the asymmetric carbon are arranged at specific positions, and regularity is generated by repeating this structure. In particular, in the case of natural polymers, unit structures having asymmetric carbons are regularly arranged, so that the intramolecular structure is presumed to be controlled in a higher order. Furthermore, when an aromatic or aliphatic carbamate group is introduced into the polymer as a modifying group, the intramolecular / intermolecular hydrogen bond is generated by immobilizing the hydroxy group in the repeating unit, thereby immobilizing the structure of the polymer. Therefore, it is considered that the orientation of the polymer becomes higher due to the aromatic or aliphatic carbamate group.
In addition, an aromatic or aliphatic carbamate substituted polymer and an unreacted raw material, a reaction by-product, or a compound having a structure represented by the general formula (1) added separately coexist as a polymer composition. The effect of the π-π stack or the hydrophobic interaction in addition to the hydrogen bond is presumed that the compound enters between the substituents of the carbamate-substituted polymer, and each group is easily oriented in one direction. Is done.

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 | 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 | 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 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 display device of the present invention

  The polymer composition of the present invention is a polymer composition containing a polymer having a repeating unit, the polymer having a hydroxy group and a carbamate group, and having an asymmetric carbon in the repeating unit. An aromatic or aliphatic carbamate substituted polymer, further comprising a compound having a structure represented by the general formula (1), wherein the content of the compound is higher than the aromatic or aliphatic carbamate substituted polymer. It is in the range of 0.005 to 20% by mass with respect to the molecule. This feature is a technical feature common to the inventions according to claims 1 to 8.

  As an embodiment of the present invention, it is preferable that the aromatic or aliphatic carbamate-substituted polymer has a structure represented by the general formula (2) from the viewpoint of manifesting effects.

The polymer composition of the present invention is an aromatic or aliphatic carbamate substituted polymer having a structure represented by the general formula (2), wherein -L ₂ -R ₂ and -L ₃ -R ₃ in a glucose unit. And -L ₆ -R ₆ each independently represents —CO—NH—Rc, and Rc represents an aromatic group or an aliphatic group, the hydrogen atom of the hydroxy group at the 2-position, 3-position and 6-position -L ₂ -R _2, the average value of the degree of substitution _-L 3 -R ₃ and _-L 6 -R ₆ preferably satisfies the above formula (a). Thereby, a higher-order higher-order structure can be controlled.

  The polymer composition of the present invention is an aromatic or aliphatic carbamate substituted polymer in which the content of the compound having the structure represented by the general formula (1) has the structure represented by the general formula (2). It is preferable that it exists in the range of 0.01-5 mass% with respect to. Thereby, a hydrogen bond, a π-π interaction or / and a hydrophobic interaction are suitably formed between the aromatic or aliphatic carbamate substituted polymer and the compound, and the higher order structure can be controlled.

  The optical film of the present invention is characterized by containing the polymer composition of the present invention. Thereby, the optical film excellent in orientation can be provided.

  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 from the viewpoint of expression of effects.

  The circularly polarizing plate of the present invention is characterized in that the optical film of the present invention and a polarizer are bonded. Thereby, it is possible to provide a circularly polarizing plate that exhibits excellent reverse wavelength dispersion and a phase difference of λ / 4 and that has a small phase difference variation due to humidity and heat.

  The display device according to the present invention includes the optical film according to the present invention. As a result, it is possible to provide a display device that exhibits excellent reverse wavelength dispersion and a phase difference of λ / 4 and that has a small phase difference variation due to humidity and heat.

  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, "-" showing a numerical range is used by the meaning containing the numerical value described before and behind that as a lower limit and an upper limit.

<Polymer composition>
The polymer composition of the present invention is a polymer composition containing a polymer having a repeating unit, the polymer having a hydroxy group and a carbamate group, and having an asymmetric carbon in the repeating unit. An aromatic or aliphatic carbamate substituted polymer, further comprising a compound having a structure represented by the following general formula (1), wherein the content of the compound is higher than that of the aromatic or aliphatic carbamate substituted polymer: It is in the range of 0.005 to 20% by mass with respect to the molecule.
General formula (1)
(Ra—O—) _m1 —CO— (NH—Rn) _m2
In the formula, Ra represents a hydrogen atom or an aliphatic group. Rn represents an aromatic group or an aliphatic group. When m1 represents 0, m2 represents 2. When m1 represents 1, m2 represents 1.
Hereinafter, the compound having the structure represented by the general formula (1) and the aromatic or aliphatic carbamate substituted polymer will be described.

<Compound having the structure represented by the general formula (1)>
The compound having the structure represented by the general formula (1) will be described.
General formula (1)
(Ra—O—) _m1 —CO— (NH—Rn) _m2
In the formula, Ra represents a hydrogen atom or an aliphatic group. Rn represents an aromatic group or an aliphatic group. When m1 represents 0, m2 represents 2. When m1 represents 1, m2 represents 1. The aromatic group represented by Rn represents any of an aryl group, a substituted aryl group, a heteroaryl group, and a substituted heteroaryl group.

Ra is more preferably an aliphatic group from the viewpoint of compatibility, and for example, an alkyl group such as a methyl group, an ethyl group, or an isopropyl group is particularly preferable because of easy orientation.
Examples of the aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a naphthacenyl group, and a triphenylenyl group. Examples of heteroaryl groups include pyridyl, thienyl, thiazolyl, benzothiazolyl, benzoxazolyl, furyl, and imidazolyl groups.
Particularly preferred as the aromatic group represented by Rn is a phenyl group, a naphthyl group or a thienyl group, and among them, a phenyl group is particularly preferred.
As the aliphatic group represented by Rn, an alkyl group such as a methyl group, an ethyl group, or an isopropyl group is particularly preferable from the viewpoint of the effects of both hydrogen bonding and hydrophobic interaction.
Examples of the aliphatic group mean an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, a substituted alkynyl group, an aralkyl group, and a substituted aralkyl group. Specific examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, hexyl group, 2-ethylhexyl group, octyl group, normal decyl group, normal dodecyl group, 3, 5,5-trimethylhexyl group etc. are mentioned.

These groups may be further substituted with other groups. The substituent may be any group that does not inhibit π-π interaction or hydrogen bonding, and an aliphatic group is an example.
The aliphatic group means an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, a substituted alkynyl group, an aralkyl group, and a substituted aralkyl group. Specific examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, hexyl group, 2-ethylhexyl group, octyl group, normal decyl group, normal dodecyl group, 3, 5,5-trimethylhexyl group, benzyl group, 2-phenethyl group and the like can be mentioned. These groups may be further substituted with other groups. Examples of the substituent include an aliphatic group, a halogen atom, an alkylsulfonyl group, an arylsulfonyl group, an acyl group, an acylamino group, a sulfamoyl group, and a carbamoyl group.

The compound having the structure represented by the general formula (1) may be synthesized and added in accordance with a general synthesis method, or may be reacted when an aromatic or aliphatic carbamate substituent is introduced into a polymer. The agent may be generated in a reaction solution in which the reaction proceeds to introduce a substituent, or may be generated by reacting with water, methanol, ethanol or the like during the reaction treatment.
For example, when phenylisocyanate is hydrolyzed and decarboxylated with moisture and heat to produce aniline, diphenylurea is produced from aniline and the remaining phenylisocyanate. Further, when phenyl isocyanate reacts with methanol, methyl phenylcarbamate is produced, and when reacted with water, carbamic acid is produced.

<Aromatic or aliphatic carbamate substituted polymer>
The aromatic or aliphatic carbamate substituted polymer according to the present invention has at least one asymmetric carbon in the repeating unit, and further contains at least one hydroxy group as a whole of the aromatic or aliphatic carbamate substituted polymer. And a polymer having an aromatic carbamate group or an aliphatic carbamate group.
In the present invention, asymmetric carbon means carbon bonded to four different atoms or atomic groups.
The proportion of hydroxy groups in the whole aromatic or aliphatic carbamate substituted polymer is preferably in the range of 1 to 30% by mass, more preferably 5 to 20% by mass.

The aromatic or aliphatic carbamate group represents a substituent in which an aromatic group or aliphatic group and a carbamate group are linked, and specifically, is a substituent represented by the following general formula (A).
Formula (A)
* -O-CO-NH-Rc
In the general formula (A), Rc represents an aromatic group or an aliphatic group.

In the present invention, when an aromatic group or an aliphatic group is linked to a carbamate group, the hydrophobicity of the cellulose derivative is increased, the compatibility with an organic solvent is improved, and the compatibility with other resins is also increased. I guess that.
In addition, since aromatic groups and aliphatic groups are bonded to carbamate groups, in addition to hydrogen bonds, interactions such as π-π stack and hydrophobic interactions are likely to be formed. It is presumed that the compound having the structure represented by the general formula (1) enters between the substituents of the carbamate-substituted polymer, and each group is easily oriented in one direction.
Moreover, content of the compound which has a structure represented by General formula (1) exists in the range of 0.005-20 mass% with respect to an aromatic or aliphatic carbamate substituted polymer, 0.01-10 Within the range of mass% is preferable, and within the range of 0.01 to 5 mass% is more preferable.

The aromatic group specifically means an aryl group, a substituted aryl group, a heteroaryl group or a substituted heteroaryl group.
Examples of the aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a naphthacenyl group, and a triphenylenyl group.
Examples of the heteroaryl group include pyridyl group, thienyl group, thiazolyl group, benzothiazolyl group, benzoxazolyl group, furyl group, imidazolyl group and the like.
An aliphatic group means an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, a substituted alkynyl group, an aralkyl group, and a substituted aralkyl group.
Specific examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, hexyl group, 2-ethylhexyl group, octyl group, normal decyl group, normal dodecyl group, 3, 5,5-trimethylhexyl group etc. are mentioned.
These groups may be further substituted with other groups. Examples of the other group include an aliphatic group, and the aliphatic group included in the general formula (1) can be similarly used.
* Represents a moiety where an aromatic or aliphatic carbamate group is bonded to the polymer.

Next, an aromatic or aliphatic carbamate substituted polymer having a hydroxy group and a carbamate group and having an asymmetric carbon in the repeating unit will be described.
The aromatic or aliphatic carbamate substituted polymer preferably has a structure represented by the following general formula (2).

In the formula, 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 formed from one or more groups selected from the group consisting of a single bond, —CO—, —CO—NH— and — (Lw—O) q—. Represents a divalent linking group. Lw represents an alkylene group, and q represents an integer of 1 to 10. p represents an average degree of polymerization and represents an integer of 10 to 2000.
As the linking group represented by L ₂ , L ₃ and L ₆ , —CO— or —CO—NH— is particularly preferable.

Further, the aromatic or aliphatic carbamate substituted polymer having a structure represented by the general formula (2), by _{-L 2 -R 2, -L 3 -R} 3 and _-L 6 -R ₆ in a glucose unit -L ₂ -R ₂ , -L ₃ -R ₃ and -L ₆ -R ₆ each independently represent -CO-NH-Rc, where Rc represents an aromatic group or an aliphatic group; It is preferable that the average value of the degree of substitution of the hydrogen atoms of the 3- and 6-position hydroxy groups (hereinafter referred to as “the degree of substitution by the modified substituent 2”) satisfies the following formula (a).
Formula (a):
0.00 <{(substitution degree with -L ₂ -R ₂ ) + (substitution degree with -L ₃ -R ₃ ) + (substitution degree with -L ₆ -R ₆ )} ≦ 2.50
The degree of substitution by the modified substituent 2 is preferably more than 0.00 and 2.50 or less, more preferably in the range of 0.01 to 1.00, and more preferably in the range of 0.01 to 0.50. A range of 0.03 to 0.30 is particularly preferable.

<< Synthesis Method of Aromatic or Aliphatic Carbamate-Substituted Polymer >>
The synthesis method of the aromatic or aliphatic carbamate substituted polymer of the present invention will be described.
As a specific method for producing the aromatic or aliphatic carbamate-substituted polymer of the present invention, a raw material polymer is dissolved in pyridine and a predetermined amount of an isocyanate compound such as phenyl isocyanate is dropped into the solution. Can be reacted. Although the reaction time depends on the degree of substitution of the carbamate substituent, the reaction can be carried out for about 2 to 10 hours.
The reaction product can be precipitated by adding an excess amount of a poor solvent of a carbamate-modified polymer composition such as methanol, and separated by filtration. For collecting the precipitate, a known material such as a filter cloth or a glass filter can be used as appropriate, and a glass filter is particularly preferred.
The filtrate is obtained by drying by a known drying method such as vacuum drying. What is necessary is just to confirm the degree of drying by measuring mass and confirming that it is a constant weight with which a reduction | decrease is not seen.

Next, the conditions for the carbamate reaction will be described.
The reaction solvent is not particularly limited as long as it is excellent in solubility of raw materials and products and does not inhibit the reaction, and can be appropriately selected depending on the kind of raw materials.
Examples of such solvents include ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, and isophorone, ester solvents such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, and methyl formate, pyridine, N, N-dimethyl. Nitrogen-containing compounds such as formamide, N, N-dimethylacetamide, N-methylpyrrolidone, acetonitrile, nitromethane, ethers (cyclic ethers, chain ethers) such as tetrahydrofuran, dioxane, dioxolane, dichloromethane, chloroform, dichloroethane And halogenated hydrocarbons such as tetrachloroethane and carbon tetrachloride, and sulfur-containing compounds such as dimethyl sulfoxide.
Among these, pyridine, N, N-dimethylformamide, N-methylpyrrolidone, and dichloromethane are preferable in view of solubility of raw materials and products, and pyridine is particularly preferable. A solvent can be used individually or in combination of 2 or more types.
The concentration in the reaction system can be appropriately selected in consideration of solubility, reaction efficiency, etc., but is generally about 2 to 50% by mass, preferably about 5 to 20% by mass.

Examples of the base include nitrogen-containing aromatic compounds such as pyridine and dimethylaminopyridine, tertiary amines such as triethylamine, tri-n-butylamine, and diisopropylethylamine, and inorganic bases. The reaction can be carried out even in the absence of a base.
The reaction solvent is not particularly limited as long as it is a solvent that dissolves the polymer composition, and preferably, dimethyl sulfoxide, dimethylformamide, N-methylpyrrolidone, dimethylimidazolidinone, acetone, tetrahydrofuran, and the like are exemplified. .
Although reaction temperature can be adjusted with the kind of raw material, Preferably, it is 10-100 degreeC, More preferably, it is 40-80 degreeC. Above 10 ° C., the reactivity of the reactant such as isocyanate is optimal, and the reaction time does not take too long. Moreover, it can suppress that a polymer | macromolecule decomposes | disassembles in the reaction solution in which a base coexists, or the coloring degree of a reaction product raises because it is 100 degrees C or less.

There is no restriction | limiting in particular as the addition method to the reaction system of isocyanate, For example, the method of adding collectively and the method of adding sequentially (continuous or intermittent addition) are mentioned. In the present invention, it is preferable to add sequentially (added continuously or intermittently) in terms of easy control of the reaction.
The obtained aromatic or aliphatic carbamate substituted polymer can be isolated and purified by ordinary operations such as reprecipitation.
Examples of the solvent (reprecipitation solvent) used in the reprecipitation operation from the reaction solution include aliphatic hydrocarbons such as pentane and hexane, alicyclic hydrocarbons such as cyclohexane, and aromatic carbonization such as benzene and xylene. Hydrogen, halogenated hydrocarbons such as methylene, chloroform, chlorobenzene and dichlorobenzene, nitrated hydrocarbons such as nitromethane, nitriles such as acetonitrile and benzonitrile, diethyl ether, diisopropyl ether, tetrahydrofuran and 1,4-dioxane Ethers such as acetone, methyl ethyl ketone, carboxylic acids such as acetic acid, esters such as ethyl acetate and butyl acetate, carbonates such as dimethyl carbonate, diethyl carbonate, and ethylene carbonate, methanol, ethanol, and propano , Isopropyl alcohol, alcohol and water-butanol and the like.

The amount of the reprecipitation solvent can be appropriately selected in consideration of efficiency, yield, etc. Generally, it is 100 to 1000 parts by mass (1 to 10 times), preferably 200 to 100 parts by mass with respect to 100 parts by mass of the polymer solution. 800 parts by mass (2 to 8 times).
The temperature for reprecipitation can be appropriately selected in consideration of efficiency and operability, but is usually about 0 to 50 ° C., preferably about room temperature (for example, about 20 to 35 ° C.). The reprecipitation operation can be performed by a known method such as a batch method or a continuous method using a conventional mixing vessel such as a stirring tank.
The re-precipitated polymer composition is usually subjected to conventional solid-liquid separation such as filtration and centrifugation, and dried before use. Filtration may be performed under pressure if necessary using a solvent-resistant filter medium. Drying is performed at a temperature of about 30 to 100 ° C., preferably about 40 to 80 ° C. under normal pressure or reduced pressure (preferably under reduced pressure).

  Examples of the solvent used in the reprecipitation operation include aliphatic hydrocarbons such as pentane and hexane, alicyclic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as benzene and xylene, dichloromethane, chloroform, chlorobenzene, and dioxane. Halogenated hydrocarbons such as chlorobenzene, nitrated hydrocarbons such as nitromethane, nitriles such as acetonitrile and benzonitrile, ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran and 1,4-dioxane, acetone, methyl ethyl ketone, etc. Ketones, carboxylic acids such as acetic acid, esters such as ethyl acetate and butyl acetate, carbonates such as dimethyl carbonate, diethyl carbonate, and ethylene carbonate, methanol, ethanol, propanol, isopropyl alcohol , And alcohols butanol, and water.

The following specific examples are shown as examples of the aromatic or aliphatic carbamate-substituted polymer according to the present invention, the compound having the structure represented by the general formula (1), and the polymer composition of the present invention.
Table 1 shows an example of a polymer used as a raw material for the aromatic or aliphatic carbamate substituted polymer. Tables 2-1 and 2-2 show examples of the aromatic or aliphatic carbamate substituted polymers represented by the general formula (2). Tables 3-1 and 3-2 show examples of compounds having a structure represented by the general formula (1) (hereinafter referred to as “aromatic or aliphatic compounds” in the table). Tables 4-1 and 4-2 show examples of the polymer composition of the present invention. The substituent introduced at the 2-position, 3-position or 6-position of the starting polymer was defined as “modified substituent 1”, and the degree of substitution by the modified substituent 1 and the total degree of substitution are shown in Table 1. Moreover, content [mass%] of the compound which has a structure represented by General formula (1) in the following table | surfaces represents the ratio with respect to the mass of substituted polymer. Further, the mixing ratio of other polymers represents the content in the polymer composition.

<Analysis of substitution degree>
In order to determine the degree of substitution of each substituent in the aromatic or aliphatic carbamate substituted polymer according to the present invention, a nuclear magnetic resonance analyzer can be used as the simplest method. That is, the aromatic or aliphatic carbamate substituted polymer according to the present invention can measure the degree of substitution for each substituent using ¹ H-NMR.
As a typical example, phenyl carbamate-substituted cellulose acetate will be specifically described.
After dissolving a suitable amount of phenyl carbamate cellulose acetate in a solvent such as deuterated chloroform, deuterated dichloromethane or deuterated dimethylformamide, the signal intensity of protons derived from aromatic groups with a chemical shift of 7 to 8 ppm and a chemical shift of 2 to 3 ppm The degree of acyl group substitution and the degree of phenyl carbamate substitution can be calculated from the intensity ratio of these by measuring the methyl proton of the nearby acetyl group.

The degree of carbamate substitution in the present invention refers to, for example, —L ₂ —R of the 2-position, 3-position and 6-position hydroxy groups in the aromatic carbamate-substituted polymer having a structure represented by the general formula (2). _{2, -L} 3 _-R 3, denote the degree of substitution by groups _-L 6 -R _6. The aromatic carbamate-substituted polymer in the present invention further has a substituent such as a phenyl group in the carbamate group as in the case of phenyl carbamate-substituted cellulose acetate. The same applies to the case of having an aliphatic group.

  Structure represented by general formula (1) in a polymer composition obtained by mixing a compound having an aromatic or aliphatic carbamate substituted polymer and a structure represented by general formula (1) in a mixed state at the synthesis stage The quantification of the compound having a value is determined by measuring the composition of the polymer composition by gas chromatography.

<Quantitative determination by gas chromatography>
Equipment used: Gas chromatography GC-14B manufactured by Shimadzu Corporation
Separation column: Capillary column DB-17 (0.32 mmφ × 30 m) manufactured by J & W SCIENTIFIC INC
Separation conditions: initial temperature 50 ° C., 3 minutes holding temperature increase rate: 40 ° C./min
Final temperature: 140 ° C, 1.5 minute holding Injection temperature: 250 ° C
Detector temperature: 250 ° C
Flow rate: Nitrogen 25mL / min
Detector: FID
Sample preparation: The sample was diluted about 10 times with tetrahydrofuran, and toluene was used as an internal standard substance.

Moreover, it is preferable that the polymer composition of the present invention further contains another polymer.
As other polymers, cellulose, chitin, hyaluronic acid, dextrin and the like can be preferably used.
An example of a method for synthesizing the polymer composition of the present invention is shown below.

[Synthesis Example 1: Synthesis of Polymer Composition P-1]
In a 500 mL four-necked flask equipped with a cooling tube, a nitrogen introduction tube, a stirrer, and a thermometer, 50.0 g of cellulose acetate (A-1) vacuum-dried at 60 ° C. for 12 hours was added, and 250 mL of pyridine was added to suspend the suspension. After making the suspension, 6.3 g of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added.
Next, nitrogen was introduced, the temperature was raised to 80 ° C. with stirring, and the mixture was reacted for 6 hours. Then, after cooling to 25 degreeC, the reaction liquid was dripped in ethanol 500mL, and precipitation was produced | generated. The product obtained by filtration from the precipitate was dissolved by adding 40 mL of acetone, and then dropped into 200 mL of methanol and 200 mL of pure water to cause precipitation.
30 mL of acetone was added to and dissolved in the product obtained by filtration from the precipitate, and then dropped into 400 mL of pure water to generate a precipitate. The product filtered off from the precipitate was washed with water and vacuum-dried at 60 ° C. for 4 hours to obtain 48.0 g of a polymer composition P-1.

As a result of ¹ H-NMR analysis, the degree of carbamate substitution of P-1 was 0.10. The degree of substitution was determined by comparing the chemical shift (3.4 to 5.5 ppm) area of proton derived from the cellulose skeleton with the chemical shift (6.7 to 7.8 ppm) area of the proton of the phenyl group.
The content of methyl phenylcarbamate was 0.01% by mass as determined by gas chromatography.

[Synthesis Example 2: Synthesis of Polymer Composition P-9]
Into a 500 mL four-necked flask equipped with a cooling tube, a nitrogen introduction tube, a stirrer, and a thermometer, 50.0 g of cellulose acetate (M-1) vacuum-dried at 60 ° C. for 12 hours was added, and 250 mL of pyridine was added to suspend. After making it a turbid liquid, 6.2 g of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added.
Next, nitrogen was introduced, and the temperature was raised to 120 ° C. with stirring, followed by reaction for 4 hours. Then, after cooling to 25 degreeC, the reaction liquid was dripped in ethanol 500mL, and precipitation was produced | generated. The product obtained by filtration from the precipitate was dissolved by adding 40 mL of dichloromethane, and then dropped into 300 mL of isopropyl alcohol and 300 mL of pure water to cause precipitation.
30 mL of acetone was added to and dissolved in the product obtained by filtration from the precipitate, and then dropped into 400 mL of pure water to generate a precipitate. The product filtered off from the precipitate was washed with water and vacuum dried at 60 ° C. for 4 hours to obtain 45.5 g of a polymer composition P-9.

As a result of ¹ H-NMR analysis, the degree of carbamate substitution of P-9 was 0.10. The degree of substitution was determined by comparing the chemical shift (3.4 to 5.5 ppm) area of proton derived from the cellulose skeleton with the chemical shift (6.7 to 7.8 ppm) area of the proton of the phenyl group.
The contents of methyl phenylcarbamate and diphenylurea were 0.01% by mass and 0.05% by mass, respectively, as determined by gas chromatography.

[Synthesis Example 3: Synthesis of Polymer Composition P-16]
In a 500 mL four-necked flask equipped with a cooling tube, a nitrogen introduction tube, a stirrer, and a thermometer, 50.0 g of cellulose acetate (M-1) vacuum-dried at 60 ° C. for 12 hours was placed, and 200 mL of dimethylimidazolidinone was added. After adding a suspension, 7.5 g of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added.
Nitrogen was introduced, and the temperature was raised to 80 ° C. with stirring, followed by reaction for 6 hours. Then, after cooling to 25 degreeC, the reaction liquid was dripped in methanol 500mL, and the precipitation was produced | generated. After filtration, washing with methanol and vacuum drying at 60 ° C. for 4 hours, 45.3 g of a polymer composition P-16 was obtained. The content of methyl phenylcarbamate was 0.10% by mass as determined by gas chromatography.

As a result of ¹ H-NMR analysis, the degree of carbamate substitution of P-16 was 0.20. The degree of substitution was determined by comparing the chemical shift (3.4 to 5.5 ppm) area of proton derived from the cellulose skeleton with the chemical shift (6.7 to 7.8 ppm) area of the proton of the phenyl group.

[Synthesis Example 4: Synthesis of Polymer Composition P-24]
Into a 500 mL four-necked flask equipped with a cooling tube, a nitrogen introduction tube, a stirrer, and a thermometer, 50.0 g of cellulose acetate (M-1) vacuum-dried at 60 ° C. for 12 hours was added, and 250 mL of pyridine was added to suspend. After making it a turbid liquid, 8.5 g of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added.
Next, nitrogen was introduced and the temperature was raised to 120 ° C. with stirring, followed by reaction for 3 hours. Then, after cooling to 25 degreeC, the reaction liquid was dripped in methanol 500mL, and the precipitation was produced | generated. Tetrahydrofuran (40 mL) was added to the product obtained by filtration from the precipitate to dissolve it, and then dropped into 300 mL of isopropyl alcohol and 300 mL of pure water to cause precipitation.
30 mL of acetone was added to and dissolved in the product obtained by filtration from the precipitate, and then dropped into 400 mL of pure water to generate a precipitate. The product filtered off from the precipitate was washed with water and vacuum dried at 60 ° C. for 4 hours to obtain 45.5 g of a polymer composition P-24.

As a result of ¹ H-NMR analysis, the degree of carbamate substitution of P-24 was 0.25. The degree of substitution was determined by comparing the chemical shift (3.4 to 5.5 ppm) area of proton derived from the cellulose skeleton with the chemical shift (6.7 to 7.8 ppm) area of the proton of the phenyl group.
The content of diphenylurea was 0.10% by mass as determined by gas chromatography.

[Synthesis Example 5: Synthesis of Polymer Composition P-27]
In a 500 mL four-necked flask equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer, 50.0 g of cellulose acetate (M-1) vacuum-dried at 60 ° C. for 12 hours was placed, and 200 mL of dimethylformamide and 10 mL of pyridine were added. Was added to make a suspension, and 8.1 g of m-tolyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added.
Nitrogen was introduced and the temperature was raised to 80 ° C. with stirring, followed by reaction for 8 hours. Then, after cooling to 25 degreeC, the reaction liquid was dripped in methanol 500mL, and the precipitation was produced | generated. After separation by filtration, 30 mL of acetone was added to the obtained polymer and dissolved, and then dropped into 200 mL of methanol and 200 mL of pure water to cause precipitation.
After separation by filtration, it was washed with methanol and vacuum-dried at 60 ° C. for 8 hours to obtain 50.1 g of a polymer composition P-27. The content of methyl m-tolylcarbamate was 0.10% by mass as determined by gas chromatography.

As a result of ¹ H-NMR analysis, the degree of carbamate substitution of P-27 was 0.10. The degree of substitution was determined by comparing the chemical shift (3.4 to 5.5 ppm) area of proton derived from the cellulose skeleton with the chemical shift (6.7 to 7.8 ppm) area of the proton of the phenyl group.

[Synthesis Example 6: Synthesis of Polymer Composition P-38]
Into a 500 mL four-necked flask equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer, 50.0 g of cellulose acetate (M-1) vacuum-dried at 60 ° C. for 12 hours is added, and 300 mL of pyridine is added to suspend. After preparing a turbid solution, 4.1 g of ethyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added.
Nitrogen was introduced and the temperature was raised to 80 ° C. with stirring, followed by reaction for 8 hours. Then, after cooling to 25 degreeC, the reaction liquid was dripped in methanol 500mL, and the precipitation was produced | generated. After separation by filtration, 30 mL of acetone was added to the obtained polymer and dissolved, and then dropped into 200 mL of methanol and 200 mL of pure water to cause precipitation.
After separation by filtration, it was washed with methanol and vacuum-dried at 60 ° C. for 8 hours to obtain 50.1 g of a polymer composition P-38. The content of diethylurea was 0.10% by mass as determined by gas chromatography.

As a result of ¹ H-NMR analysis, the degree of carbamate substitution of P-38 was 0.10. The degree of substitution was determined by comparing the chemical shift (3.4 to 5.5 ppm) area of protons derived from the cellulose skeleton with the chemical shift (1.0 to 1.5 ppm) area of protons in the ethyl carbamate group. .

[Synthesis Example 7: Synthesis of Polymer Composition P-52]
Into a 500 mL four-necked flask equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer, 50.0 g of cellulose acetate (M-1) vacuum-dried at 60 ° C. for 12 hours is added, and 300 mL of pyridine is added to suspend. After the suspension, 6.1 g of hexyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added.
Nitrogen was introduced and the temperature was raised to 80 ° C. with stirring, followed by reaction for 8 hours. Then, after cooling to 25 degreeC, the reaction liquid was dripped in methanol 500mL, and the precipitation was produced | generated. After separation by filtration, 30 mL of acetone was added to the obtained polymer and dissolved, and then dropped into 200 mL of methanol and 200 mL of pure water to cause precipitation.
After separation by filtration, it was washed with methanol and vacuum-dried at 60 ° C. for 8 hours to obtain 50.1 g of a polymer composition P-52. The content of dihexyl urea was 0.10% by mass as determined by gas chromatography.

As a result of ¹ H-NMR analysis, the degree of carbamate substitution of P-52 was 0.10. The degree of substitution is determined by comparing the chemical shift (3.4 to 5.5 ppm) area of protons derived from the cellulose skeleton with the chemical shift (0.9 to 1.1 ppm) area of protons of the hexyl carbamate group. did.

[Synthesis Example 8: Synthesis of Polymer Composition P-68]
In a 500 mL four-necked flask equipped with a cooling tube, a nitrogen introduction tube, a stirrer, and a thermometer, 50.0 g of cellulose acetate (M-3) vacuum-dried at 60 ° C. for 12 hours was placed, and 200 mL of N-methylpyrrolidone was added. After adding 10 mL of pyridine to form a suspension, 9.3 g of 3,5-dimethylphenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added. Nitrogen was introduced and the temperature was raised to 80 ° C. with stirring, followed by reaction for 10 hours.
Then, after cooling to 25 degreeC, the reaction liquid was dripped in methanol 500mL, and the precipitation was produced | generated. After separation by filtration, 30 mL of acetone was added to the obtained polymer and dissolved, and then dropped into 200 mL of methanol and 200 mL of pure water to cause precipitation.
After separation by filtration, it was washed with methanol and vacuum-dried at 60 ° C. for 8 hours to obtain 52.0 g of a polymer composition P-68. The content of methyl 3,5-dimethylphenylcarbamate was 0.01% by mass as determined by gas chromatography.

As a result of ¹ H-NMR analysis, the degree of carbamate substitution of P-68 was 0.10. The degree of substitution was determined by comparing the chemical shift (3.4 to 5.5 ppm) area of proton derived from the cellulose skeleton with the chemical shift (6.7 to 7.8 ppm) area of the proton of the phenyl group.

[Comparative Synthesis Example 1: Synthesis of Comparative Polymer Composition E-1]
In a 500 mL four-necked flask equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer, 50.0 g of cellulose acetate (M-1) vacuum-dried at 60 ° C. for 12 hours was placed, and 200 mL of dimethylformamide and 20 mL of pyridine were added. Was added to form a suspension, and 4.2 g of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added.
Nitrogen was introduced and the temperature was raised to 80 ° C. with stirring, followed by reaction for 18 hours. Then, after cooling to 25 degreeC, the reaction liquid was dripped in methanol 500mL, and the precipitation was produced | generated. After separation by filtration, 50 mL of dichloromethane was added to the obtained polymer to dissolve it, and then dropped into 500 mL of methanol to cause precipitation.
After separation by filtration, the obtained polymer was dissolved in 50 mL of tetrahydrofuran and dropped into 500 mL of methanol to form a precipitate. After separation by filtration, it was washed with methanol, and again dissolved in 30 mL of tetrahydrofuran and added dropwise to 300 mL of methanol to form a precipitate. After filtration, it was washed with methanol and dried in vacuo at 60 ° C. for 8 hours. 40.1 g of comparative polymer composition E-1 was obtained. As a result of gas chromatographic determination, the methyl phenylcarbamate content was below the measurement limit (0.0000% by mass).

As a result of ¹ H-NMR analysis, the degree of carbamate substitution of E-1 was 0.10. The degree of substitution was determined by comparing the chemical shift (3.4 to 5.5 ppm) area of proton derived from the cellulose skeleton with the chemical shift (6.7 to 7.8 ppm) area of the proton of the phenyl group.

[Comparative Synthesis Example 2: Synthesis of Comparative Polymer Composition E-2]
In a 500 mL four-necked flask equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer, 50.0 g of cellulose acetate (M-1) vacuum-dried at 60 ° C. for 12 hours was placed, and 200 mL of dimethylformamide and 20 mL of pyridine were added. Was added to form a suspension, and 4.2 g of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added.
Nitrogen was introduced and the temperature was raised to 80 ° C. with stirring, followed by reaction for 18 hours. Then, after cooling to 25 degreeC, the reaction liquid was dripped in methanol 500mL, and the precipitation was produced | generated. After separation by filtration, the resulting polymer was dissolved by adding 50 mL of tetrahydrofuran, and then dropped into 300 mL of methanol and 200 mL of pure water to cause precipitation.
After separation by filtration, the obtained polymer was dissolved in 30 mL of tetrahydrofuran and dropped into 300 mL of methanol to form a precipitate. After separation by filtration, it was washed with methanol, and again dissolved in 30 mL of tetrahydrofuran and dropped into 200 mL of methanol to form a precipitate. After filtration, it was washed with methanol and dried in vacuo at 60 ° C. for 8 hours. 45.3 g of a comparative polymer composition E-2 was obtained. The content of methyl phenylcarbamate was 0.0008% by mass as determined by gas chromatography.

The degree of carbamate substitution of E-2 was 0.10 as a result of ¹ H-NMR analysis. The degree of substitution was determined by comparing the chemical shift (3.4 to 5.5 ppm) area of proton derived from the cellulose skeleton with the chemical shift (6.7 to 7.8 ppm) area of the proton of the phenyl group.

[Comparative Synthesis Example 3: Synthesis of Comparative Polymer Composition E-7]
0.0005% by mass of methyl benzoate was added to Comparative Polymer Composition E-1 synthesized by the same method as Comparative Synthesis Example 1 to obtain Comparative Polymer Composition E-7.

[Comparative Synthesis Example 4: Synthesis of Comparative Polymer Composition E-11]
A 500 mL four-necked flask equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer was charged with 50.0 g of cellulose acetate (M-1) that had been vacuum-dried at 60 ° C. for 12 hours, and 200 mL of dimethylformamide and 20 mL of pyridine. Was added to form a suspension, and 4.5 g of benzoyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added.
Nitrogen was introduced, and the temperature was raised to 80 ° C. with stirring, followed by reaction for 6 hours. Then, after cooling to 25 degreeC, the reaction liquid was dripped in methanol 500mL, and the precipitation was produced | generated. After separation by filtration, the obtained polymer was dissolved by adding 40 mL of acetone, and then dropped into 200 mL of methanol and 200 mL of pure water to cause precipitation.
After separation by filtration, the polymer was washed with methanol, and the obtained polymer was again dissolved in 30 mL of acetone and dropped into 400 mL of pure water to form a precipitate. After separation by filtration, it was washed with water and vacuum dried at 60 ° C. for 4 hours to obtain 43.8 g of a comparative polymer composition E-11.
The content of methyl benzoate was 0.001% by mass as determined by gas chromatography.

The degree of carbamate substitution of E-11 was 0.15 as a result of ¹ H-NMR analysis. The degree of substitution is determined by comparing the chemical shift area (3.4 to 5.5 ppm) of protons derived from the cellulose skeleton with the chemical shift area (6.7 to 7.8 ppm) of protons on the benzoyl group benzene ring. did.

  The polymer composition of the present invention can also be obtained by a method of adding a compound having a structure represented by the general formula (1) to an aromatic or aliphatic carbamate substituted polymer. As an example, a method for preparing P-1 when added is shown.

[Preparation Example 1: Preparation of polymer composition P-1]
To 30.00 g of the polymer composition E-1 produced by the above method, 3.0 mg of methyl phenylcarbamate was added to obtain a polymer composition P-1. The content of methyl phenylcarbamate was 0.01% by mass as determined by gas chromatography.

  In addition to the aromatic or aliphatic carbamate substituted polymer and the compound having the structure represented by the general formula (1), the polymer composition of the present invention preferably contains another polymer. An example of the preparation method in this case is shown.

[Preparation Example 2: Preparation of polymer composition P-2]
10.0 g of the resin (M-1) was added to 40.0 g of the polymer composition P-1 produced by the above method, and the mixture was stirred well to obtain a polymer composition P-2. .

[Optical film]
The optical film of the present invention is characterized by containing the above-described polymer composition of the present invention, and is preferably a λ / 4 retardation 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.
As a method of setting the angle of the slow axis with respect to the longitudinal direction in the range of 40 to 50 ° in this way, a method of performing oblique stretching described later on the formed film before stretching 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>
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, and therefore generally has a retardation of 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, are measured at a relative humidity of 55% for, _{n x} is the film the maximum refractive index in-plane represents the (refractive index in a slow axis direction), n _y represents the refractive index in the direction perpendicular to the slow axis in the film plane, n _z is the thickness perpendicular to the film plane The refractive index in the vertical direction is represented, and d represents the thickness (nm) of the 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, it is preferable that the display device includes this circularly polarizing plate in that the 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 polymer composition of the present invention, the optical film of the present invention can contain various additives for the purpose of imparting various functions.
The additive applicable to the present invention is not particularly limited, and may be, for example, a retardation increasing agent, a wavelength dispersion improving agent, a deterioration inhibitor, an ultraviolet absorber, a matting agent, and a plasticizer as long as the object and effects of the present invention are not impaired. 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.
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 polymer composition. preferable.

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-methylphenol, octyl-3 -[3-t-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-t-butyl-4-hydroxy-5- ( A mixture of 5-chloro-2H-benzotriazol-2-yl) phenyl] propionate can be mentioned, but is not limited thereto.
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.

(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 polymer composition solution used for the production of an optical film from the viewpoint of the effect of the addition of the deterioration inhibitor and suppressing bleeding out of the deterioration inhibitor to the film surface. It is preferably within a range of 0.01 to 1% by mass of (dope), and more preferably within a 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. The secondary particles exist as aggregates 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 separately prepared additive solutions having a polymer composition concentration of less than 5% by mass. Then, after stirring and dissolving, a method of further mixing with the polymer composition of the present invention is preferred.
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 the hydrophilic additive in advance with the matting agent fine particle dispersion and then mixing the hydrophobic additive, aggregation of the additive on the matting agent surface can be suppressed, and the haze can be suppressed. Is low, and light leakage in black display when incorporated in a liquid crystal display device is preferable.

An in-line mixer is preferably used for mixing the matting agent fine particle dispersant with the additive solution and the polymer composition 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 dope solution of the polymer composition 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 0.01 to 0.1% by mass is particularly preferable.

[Method for producing optical film containing polymer composition]
The method for producing the optical film of the present invention is not particularly limited, but a method for producing by the solvent cast method (solution film forming method) is preferable. In the solvent cast method, an optical film is produced using a solution (dope) obtained by dissolving a polymer composition 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 in the range of mol%, particularly preferably in 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 ratio of the polymer composition 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 the polymer composition and the organic solvent at room temperature (0 to 40 ° C.). High concentration solutions may be stirred under pressure and heating conditions. Specifically, the polymer composition and the organic solvent are placed in a pressure vessel and sealed, and stirred while being heated to a temperature equal to or higher 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.
Moreover, it is preferable to provide a stirring blade inside the container and stir using this. 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 polymer composition 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 polymer composition 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, the polymer composition is gradually added to an organic solvent at room temperature while stirring. The amount of the polymer composition is preferably adjusted so as to be contained in the mixture in the range of 5 to 40% by mass. The amount of the polymer composition 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 polymer composition 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.
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, if 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.

Furthermore, when this is heated within the range of 0 to 200 ° C. (preferably 0 to 150 ° C., more preferably 0 to 120 ° C., more preferably 0 to 50 ° C.), the polymer composition is dissolved in the organic solvent. To do. 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 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.
An optical film having a polymer composition is produced from a solution (dope) containing the prepared aromatic or aliphatic carbamate substituted polymer and a compound having a structure represented by the general formula (1) by a solvent cast method.

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

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 casting method, U.S. Pat. Nos. 2,336,310, 2,367,603, 2,429,078, 2,429,297, 2,429,978, 2,607,704 Nos. 2739069 and 2739070, British Patent Nos. 640731 and 736892, Japanese Patent Publication Nos. 45-4554, 49-5614, and Japanese Patent Application Laid-Open No. 60-60. There are descriptions in JP-A-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.

Two or more layers can be cast using the prepared dope to form a film. In this case, it is preferable to produce a film of the polymer composition 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. Further, when stretching 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 FIG. 1, when the optical film F is obliquely stretched in the direction of reference numeral 12, the optical film F is contracted to M ₂ by being obliquely bent. That is, when the gripping tool that holds the optical film F travels at the bending angle θ, it bends at the bending angle θ and proceeds by M ₁ . At this time, since the gripping tool has advanced by M ₂ in the film entering direction (direction orthogonal to the stretching direction (TD direction) 11), the optical film F contracted by M ₁ -M _2. Become.
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.
Considering 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. Bonding is possible and 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 within a 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 by the right and left gripping tools (tenters) at the entrance of the oblique stretching apparatus (position G in the drawing), 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 device (position G in the figure) and facing the direction substantially perpendicular to the film traveling direction (feeding direction D1). The film travels on the asymmetric rails Ji and Jo, and the film gripped by the tenter is released at the position at the end of stretching (position H in the figure).
At this time, as the left and right gripping tools opposed at the entrance of the oblique stretching apparatus (position G in the figure) travel on the left and right asymmetric rails Ji and Jo, the gripping tool Ci traveling on the Ji side is the Jo side. The positional relationship is advancing with respect to the gripping tool Co traveling.

  That is, the gripping tools Ci and Co, which are opposed to the film feeding direction D1 at the oblique stretching apparatus entrance (the gripping start position by the film gripping tool) G, are positioned at the end of the film stretching. In the state of H, a 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 will 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 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 G 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 G 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, represented by the general formula (A) described above) deviated from the main chain of the polymer composition that is a matrix resin by performing a shrinkage treatment following the stretching treatment. The orientation of the optical adjusting agent is rotated by shrinking the orientation of the compound) in the direction perpendicular to the stretching direction (the fast axis direction), and the main axis of the optical adjusting agent is the matrix resin. Can be matched to the main chain. 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 within the range of Tg to (Tg + 30) ° C., and the temperature of the stretching zone is within the range of Tg to (Tg + 30) ° C. The temperature of the zone is preferably 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 create a temperature difference in the width direction in the stretching zone, a method of adjusting the opening degree of the nozzle that sends warm air into the temperature-controlled room to make a difference in the width direction, or a method of controlling heating by arranging heaters in the width direction, etc. 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, thickness unevenness in the width direction can be reduced.
In the stretching zone of the oblique stretching apparatus, the thickness unevenness in the width direction can be further improved 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.

Examples of the oblique stretching method applicable in the present invention include the stretching methods shown in FIGS. 3A to 3C, FIGS. 4A and 4B in addition to the method shown in FIG.
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 device, 16 denotes a film feeding device, 17 denotes a transport direction changing device, 18 denotes a winding device, and 19 denotes a film forming device. 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
3A to 3C show patterns in which the arrangement of the film feeding device 16 and the conveyance direction changing device 17 is changed.
4A and 4B show a pattern in which the film formed by the film forming apparatus 19 is directly fed out 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, the generation of wrinkles of the film can be effectively prevented, and the winding property of the film is improved, 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 formation 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 film forming method described above.
In the melt film forming method, a composition containing an additive such as a polymer composition and a plasticizer is heated and melted to a temperature exhibiting fluidity, and then cast as a melt containing a fluid thermoplastic resin. Is the method.
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 is usually preferably kneaded and pelletized in advance.
Pelletization can be performed by a known method, for example, a dry polymer composition, a plasticizer, and other additives are fed to an extruder with a feeder, and kneaded using a single or twin screw extruder, It can be obtained by extruding in a strand form from a die, 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, but the raw material powder is directly fed into a feeder and supplied to an 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. After removing foreign matter by filtering with a leaf disk type filter or the like, 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 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, an oblique stretching device or the like as described above can be preferably used. The stretching temperature is preferably carried out in the temperature range of Tg to (Tg + 60) ° C. of the resin that usually constitutes the film.

Prior to winding, the ends may be slit and trimmed to a product width, and knurling (embossing) may be applied to both ends to prevent sticking and scratching when 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 optical 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 optical 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 °. More preferably, it is more preferably in the range of 43 to 47 °, and particularly preferably in 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. It is preferable to be produced.
The circularly polarizing plate of the present invention is produced using the optical film of the present invention, and in particular, preferably produced using a λ / 4 retardation film. The effect of shielding the specular reflection of the metal electrode of the organic EL element can be exhibited at all wavelengths of light. 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 a display device including an organic EL element, 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 a phase difference film, it is possible to form an adhesive layer and to bond a polarizer and a phase difference film with 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 EL image display device, but when applied to the organic EL image display device, the effect of shielding the specular reflection of the metal electrode of the organic EL illuminant is manifested. To do.

<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 dyeing the polyvinyl alcohol film, and then 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, but from the point that 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 performed. 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 through the adhesive layer. It can manufacture by the manufacturing method including the hardening process which hardens an adhesive bond layer in the bonded 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.

[Display device]
The display device of the present invention is manufactured by including the optical film of the present invention.
The display device of the present invention preferably includes a circularly polarizing plate using the retardation film of the present invention and an organic EL element. This is because by using the retardation film of the present invention, reflection during observation can be prevented, and an organic EL display device with improved black expression can be obtained.
The screen size of the display device is not particularly limited, and can be 20 inches or more.
FIG. 5 is a schematic explanatory diagram of a configuration in the case where the display device of the present invention includes an organic EL element. The configuration of the 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. A long circularly polarizing plate C in which a polarizer 110 is sandwiched between a λ / 4 retardation film 109 and a protective film 111 is provided on an organic EL element B having a film 108 (which may be omitted) to constitute a display device A.

It is preferable that a cured layer 112 is laminated on the protective film 111.
The hardened layer 112 not only prevents the surface of the display device from being scratched 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, a display device including an organic EL element forms a light emitting element (organic EL element) by sequentially laminating a metal electrode, an organic light emitting layer, and a transparent electrode on a transparent substrate.
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, There are known configurations having various combinations such as a stacked body of an electron injection layer composed of such a light emitting layer and a perylene derivative, and a stacked body of these hole injection layer, light emitting layer, and electron injection layer. Yes.

  In the display device, 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 the recombination of these holes and electrons excites the fluorescent material. The phosphor emits light on the principle that it emits light when it 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 a display device, in order to extract light emitted from the organic light emitting layer, at least one of the electrodes needs to be transparent. Usually, a transparent electrode formed of a transparent conductor such as indium tin oxide (ITO) is used as an anode. It is preferable to use as.
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 a 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 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 display device looks like a mirror surface.

In a display device including an organic EL element having a transparent electrode on the surface side of an organic light emitting layer that emits light by applying a voltage and a metal electrode on the back side of the organic light emitting layer, the surface side (viewing side) of the transparent electrode In addition, a polarizing plate can be provided, 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 display device is transmitted only by the linearly polarized light component by the polarizer, and this linearly polarized light is generally elliptically polarized by the retardation plate, but the retardation film is particularly a λ / 4 retardation film. In addition, when the angle formed by the polarization direction of the polarizer and the retardation film is 45 ° or 135 °, circular polarization is obtained.
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 degrees shown below represent average values.
Further, the substituted polymer, aromatic or aliphatic compound (hereinafter referred to as “aromatic or aliphatic compound”) and polymer composition used as comparative examples are shown in Tables 5-1 to 5- It was shown in 3.

<< Example 1: Production of retardation film (optical film) >>
[Production of Retardation Film F-3]
(Preparation of fine particle dispersion)
Fine particles (Aerosil R812 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 using a Manton Gorin disperser to prepare a fine particle dispersion.

(Preparation of fine particle additive solution)
50 parts by mass of dimethyl chloride was placed in the dissolution tank, and 50 parts by mass of the fine particle dispersion prepared above was slowly added while sufficiently stirring the dimethyl chloride. Further, dispersion was performed with an attritor (manufactured by Nippon Coke Kogyo Co., Ltd.) so that the secondary particles had a predetermined particle size. This was filtered through Finemet NF manufactured by Nippon Seisen Co., Ltd. to prepare a fine particle additive solution.

(Preparation of dope)
Next, the following dimethyl chloride and ethanol were added to the pressure dissolution tank. The synthesized polymer composition P-1 was charged into a pressure dissolution tank containing an organic solvent while stirring. This was completely dissolved with heating and stirring.
Next, after adding the fine particle addition solution, Azumi Filter Paper No. The dope was prepared by filtration using 244.
<Dope composition>
Dimethyl chloride 340 parts by mass Ethanol 64 parts by mass Polymer composition P-1 100 parts by mass Fine particle additive solution 2 parts by mass

(Film formation)
The prepared dope was cast on a stainless steel belt support, and then the film was peeled from the stainless steel belt support.
The peeled raw film was uniaxially stretched only in the width direction (TD direction) using a tenter while heating, and the conveyance tension was adjusted so as not to shrink in the conveyance direction (MD direction).
Next, drying was terminated while the drying zone was conveyed through many rollers, and a roll-shaped raw film was produced.

(Stretching process)
Using the oblique stretching apparatus having the configuration shown in FIG. 2, this raw film is stretched in an oblique direction so that the optical slow axis of the film is 45 ° with respect to the transport direction. Phase difference film F-3 was produced.
In addition, as stretching conditions, the film thickness of the original film is such that the in-plane retardation value Ro ₅₅₀ measured at a light wavelength of 550 nm is 147 nm, the film thickness is 50 μm, and Ro ₄₅₀ / Ro ₅₅₀ is 0.82. The stretching temperature, the width direction (TD direction) and the stretching ratio in the transport direction (MD direction) were appropriately adjusted.

[Production of Retardation Films F-1, F-2, F-4 to F-98]
In the production of the retardation film F-3, the phase difference film F- was similarly obtained except that the type of the polymer composition was changed to the polymer composition described in Table 6-1 to Table 6-3. 1, F-2, F-4 to F-98 were prepared.
As the stretching conditions, the in-plane retardation value Ro ₅₅₀ and DSP (Ro ₄₅₀ / Ro ₅₅₀ ) measured at a light wavelength of 550 nm are the values described in Table 7-1 and Table 7-2. The stretching temperature, the width direction (TD direction) and the stretching ratio in the transport direction (MD direction) were appropriately adjusted.

<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, an 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 550 nm. And the measured value was substituted into the following equation to obtain the retardation value at a film thickness of 50 μm. The obtained results are shown in Tables 7-1 and 7-2.
Of formula (I): in-plane retardation _{Ro = (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

<Wavelength dispersibility>
The retardation value of the center part of the width direction of the obtained optical film was measured. For measurement, an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments) 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 nm and 550 nm. The rate was measured, and the value of Ro was obtained by substituting the measured value into the formula (I). The obtained Ro was substituted into the following formula (II) to obtain wavelength dispersion (DSP). This value is preferably 1.10 or less. The obtained results are shown in Tables 7-1 and 7-2.
Formula (II): wavelength dispersion = Ro (450 nm) / Ro (550 nm)

<Measurement of orientation coefficient>
The orientation coefficient of the retardation film was measured according to the following method.
First, the orientation coefficient will be described.
In the present invention, the measurement of the orientation coefficient employs a uniaxial orientation coefficient (orientation coefficient f _xy ).
The orientation coefficient f _xy can be obtained according to the following equation. For details of f _xy , see P.A. A. Flumoy, and W.C. J. et al. Reference can be made to Schaffers, Spectrochimica Acta, 22, 5 (1966).

f _xy represents the orientation coefficient in the in-plane direction. Further, _fxz represents an orientation coefficient in the film thickness direction. D _xy and D _xz represent infrared dichroic ratios, and both of the values are 1.00 in a completely spatially isotropic non-oriented sample.

here,
D ₀ = cot ² (δ)
Δ is an angle formed by a transition moment vector formed by molecular vibration and a molecular axis. In order to calculate this precisely, it is necessary to examine the direction of the moment of molecular vibration, but it is usually sufficient to select the vibration mode parallel to the molecular axis and the mode perpendicular to the molecular axis and calculate these as 0 ° and 90 °, respectively. Information about orientation can be obtained.
Theoretically, the orientation coefficient is 0 in the case of non-orientation, 1.0 in the case of being completely oriented in the observation direction, and -0.5 in the case of being orthogonal to the observation direction.
For each retardation film, the O—C—C stretching vibration (1039 ± 10 cm ⁻¹ maximum peak value) of the cellulose skeleton was calculated as a vibration mode (δ = 0 °) parallel to the molecular axis. The base line is a straight line connecting a minimum value between 1510 and 1530 cm ⁻¹ and a minimum value between 930 and 1000 cm ⁻¹ for C—C—O.

The peak value can be determined according to the following method.
The infrared dichroic ratio was measured using attenuated total reflection infrared spectroscopy (ATR-IR method). For specific calculation methods, see J.H. P. Hobbs, C.I. S. P. Sung (JP Hobbs, C. S. P. Sung, K. Krishan, and, S. Hill, Macromolecules, 16, 193 (1983)).
Determination of the infrared dichroic ratio was measured intensity of (strongest peak appearing between 1039cm ^-1 ± 10cm ^-1) peak derived from C-O symmetric stretching vibration of cellulose groups. The peak intensity is the wave number (xcm ⁻¹ ) of the peak top, the point having the smallest absorbance among x to (x + 50) cm ⁻¹ and the most of x to (x−50) cm ^−1. A point having a low absorbance was connected, and this was used as a baseline, and the peak intensity was measured and determined.
First, light is incident parallel to the longitudinal direction, and the absorbance (ATEx) when the polarized light is perpendicular to the incident surface and the absorbance (ATMx) when the polarized surface is parallel to the incident surface are obtained, and then parallel to the width direction. In the same manner, ATEy and ATMy were measured in the same manner, and the infrared dichroic ratios f _xy and f _xz were calculated using the above-described equations.

The specific orientation coefficient f _xy in the present invention was measured using the polarized ATR method under the following measurement conditions.
Measuring device: NICOLET380 manufactured by Thermo
Prism: Germanium Pressure between prism and sample: 30 cN · m
Area of jig for pressing sample against prism: 1 cm ²
Incident angle: 45 °
Number of reflections: 1 time Resolution: 4 cm ⁻¹
Data interpolation: 0.5 cm ^-1
The refractive index of the sample was calculated as 1.477 in the polymer composition of the present invention. The prism (germanium) was 4.00. Vertically polarized light and horizontally polarized light were incident on an incident surface composed of light incident on the sample surface and reflected light using a wire grid polarizer, and an FTIR-ATR spectrum was measured. The above measurement was performed by setting the MD direction as the x axis, the vertical direction (width direction TD) as the y axis, and the thickness direction as the z axis.

<Haze>
Using a haze meter (1001DP type, manufactured by Nippon Denshoku Industries Co., Ltd.) according to JIS K 7136-2000, the film was subjected to haze measurement at any 10 points under the conditions of 23 ° C. and 55% RH, and the average The value was determined. The results obtained were ranked according to the following levels.
◎: 0% or more and less than 0.5% ○: 0.5% or more and less than 1.0% △: 1.0% or more and less than 1.5% ×: 1.5% or more

<Evaluation of fluctuation range with respect to humidity change of phase difference>
The magnitude of the fluctuation range ΔRo with respect to the temperature and humidity change of the retardation defined by the following relational expression (r) was evaluated. In addition, the automatic birefringence meter (Oji Scientific Instruments Co., Ltd. product, KOBRA-21ADH) was used for the measuring apparatus.
Relational expression (r): ΔRo = {[Ro (23 ° C., 10% RH) −Ro (23 ° C., 80% RH)] / Ro (23 ° C., 55% RH)} × 100 (%)

In the formula, Ro (23 ° C./10% RH), Ro (23 ° C./80% RH), and Ro (23 ° C./55% RH) are 23 ° C. and 80% in an environment of 23 ° C. and 10% RH, respectively. An in-plane retardation Ro measured at a measurement light wavelength of 590 nm after the retardation film was conditioned for 36 hours under an environment of RH or an environment of 23 ° C. and 55% RH.
Moreover, the fluctuation range ΔRo with respect to the temperature / humidity change of the retardation was ranked into the following levels.
◎: 0% or more and less than 5% ○: 5% or more and less than 10% △: 10% or more and less than 15% ×: 15% or more

<Phase variation>
The wound optical film is allowed to stand for 3 months in an environment of a temperature of 23 ° C. and a humidity of 55% RH, and then a phase difference value Ro at a measurement wavelength of 550 nm is measured using KOBRA-21ADH (manufactured by Oji Scientific Instruments). Measurement was performed, and the fluctuation of the phase difference value Ro before and after being left standing was evaluated as the phase difference fluctuation ΔRo. The criteria for evaluating the phase difference fluctuation are as follows.
A: The maximum fluctuation of the Ro value is zero.
○: The maximum fluctuation of the Ro value is greater than 0 and 2 nm or less.
X: The maximum fluctuation | variation of Ro value is 5 nm or more.

<Humidity and heat resistance: dimensional change against heat and humidity change>
Two marks (crosses) were placed in the casting direction of the produced optical film, treated at 60 ° C. and 90% RH for 1000 hours, and the distance between the marks (crosses) before and after treatment was measured with an optical microscope. .
From the measurement results, wet heat resistance was evaluated as the durability of the optical film by evaluating the dimensional change according to the following criteria.
Dimensional change rate (%) = [(a1-a2) / a1] × 100
a1 represents the distance before the wet heat treatment, and a2 represents the distance after the wet heat treatment.
◎: Less than 0.3% ○: 0.3% or more, less than 0.5% △: 0.5% or more, less than 0.7% ×: 0.7% or more In Tables 7-1 and 7-2 The result of evaluation about each Example and each comparative example is shown.

  From the results shown in Table 7-1 and Table 7-2, among the optical films F-1 to F-98, the optical film of the present invention has retardation characteristics and wavelength dispersion as compared with the optical film of the comparative example. (DSP), wet heat phase difference fluctuation and haze were all found to be excellent.

In the retardation film F-1, cellulose is substituted with phenyl carbamate, but since it does not contain a low molecular compound having a structure represented by the general formula (1) in the present invention, the orientation of the phenyl group is high. It is considered that the orientation direction is also biased in the thickness direction of the film. As a result, it was found that the in-plane retardation value was small for use as a λ / 4 plate and the reverse wavelength dispersion was poor.
On the other hand, if the compound having the structure represented by the general formula (1) according to the present invention is present in the polymer composition even at 0.005%, the orientation of the phenyl group is remarkably increased. It was found that the orientation direction also increased in the in-plane direction.
In addition, since the compound having the structure represented by the general formula (1) is the remainder or by-product of the raw material reactant, the polymer composition of the present invention requires a small purification load, and the production efficiency is low. There is an advantage that the cost increases.

Example 2 Production of Display Device
(Production of circularly 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.) was bonded together with water paste to produce a circularly polarizing plate.

(Production of organic EL cell)
According to the method described in the example of JP2010-20925A using a 3 mm-thick 50 inch (127 cm) non-alkali glass, it is described in FIG. 8 of JP2010-20925A. An organic EL cell having the structure described above was produced.

(Production of display device)
After applying an adhesive to the surface of the retardation film of each circularly polarizing plate prepared above, a display device was prepared by bonding to the viewing side of the organic EL cell.

(Evaluation of display device)
About each produced said display apparatus, basic display characteristics, such as a black color characteristic and reflectivity (visibility), were evaluated in accordance with the conventional method, and the result was shown to Table 8-1 and Table 8-2.
≪Color unevenness≫
The display was displayed in black in an environment of 23 ° C. and 55% RH, observed from the front and an angle of 45 ° obliquely, and color unevenness was evaluated according to the following criteria.
A: Color unevenness was not observed.
B: Weak color unevenness was observed in an area of 1/8 or less of the display surface.
C: Weak color unevenness was observed in an area of more than ¼ of the display surface and ¼ or less.
D: Weak color unevenness was observed in an area exceeding 1/4 of the display surface.
E: Strong color unevenness was observed in an area exceeding 1/4 of the display surface.
Here, if it is C level or higher, there is no practical problem, but it is preferably B level or higher, particularly preferably A level or higher.

≪Viewing angle degradation≫
The viewing angle of the liquid crystal display device was measured using EZ-Contrast 160D manufactured by ELDIM in an environment of 23 ° C. and 55% RH. Subsequently, the viewing angle of the produced liquid crystal display device was measured in an environment of 23 ° C., 20% RH, and further 23 ° C., 80% RH, and evaluated according to the following criteria. Finally, viewing angle measurement was performed again in an environment of 23 ° C. and 55% RH, and it was confirmed that the change during the measurement was a reversible fluctuation. These measurements were made after the liquid crystal display device was placed in the environment for 5 hours.
◎: Vertical / horizontal viewing angle variation of 0 ° or more and less than 1 ° ○: Vertical / horizontal viewing angle variation of 1 ° or more and less than 3 ° Δ: Vertical / horizontal viewing angle variation of 3 ° or more and less than 5 ° The viewing angle variation is 5 ° or more. Here, if it is Δ level or more, there is no practical problem, but it is preferably ○ level or more, and particularly preferably ◎ level or more.

  As a result, it was confirmed that the display device using the optical film of the present invention has good characteristics.

  According to the present invention, a polymer composition capable of forming a high-order higher-order structure can be provided, and can be used for an optical film, a circularly polarizing plate, a display device, and the like.

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 Ji, Jo Rail Wo Width of the film before stretching W Width of the film after stretching 16 Film feeding device 17 Transport direction changing device 18 Winding device 19 Film forming device A Display device B Organic EL element C Circular polarization 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 (8)

A polymer composition containing a polymer having a repeating unit,
The polymer is an aromatic or aliphatic carbamate substituted polymer having a hydroxy group and a carbamate group and having an asymmetric carbon in the repeating unit;
Furthermore, it contains a compound having a structure represented by the following general formula (1), and
Content of the said compound exists in the range of 0.005-20 mass% with respect to the said aromatic or aliphatic carbamate substituted polymer, The polymer composition characterized by the above-mentioned.
General formula (1)
(Ra—O—) _m1 —CO— (NH—Rn) _m2
(In the formula, Ra represents a hydrogen atom or an aliphatic group. Rn represents an aromatic group or an aliphatic group. When m1 represents 0, m2 represents 2. When m1 represents 1, m2 represents m2. Represents 1) The polymer composition according to claim 1, wherein the aromatic or aliphatic carbamate-substituted polymer has a structure represented by the following general formula (2).

(Wherein R ₂ , R ₃ and R ₆ each independently represents a hydrogen atom, an aliphatic group or an aromatic group. L ₂ , L ₃ and L ₆ each independently represents a single bond, —CO -, -CO-NH- and-(Lw-O) q- represents a divalent linking group formed from one or more groups selected from the group consisting of:-Lw represents an alkylene group, q is Represents an integer of 1 to 10. p represents an average degree of polymerization and represents an integer of 10 to 2000.) In the aromatic or aliphatic carbamate substituted polymer having the structure represented by the general formula (2),
_-L 2 _-R 2 in glucose units, _-L 3 -R ₃ and _-L 6 -R ₆ is, represents a -CO-NH-Rc independently if Rc represents an aromatic group or an aliphatic group The average value of the degree of substitution of —H ₂ —R ₂ , —L ₃ —R ₃ and —L ₆ —R ₆ of the hydrogen atom of the hydroxy group at the 2nd, 3rd and 6th positions is represented by the following formula (a): The polymer composition according to claim 2, wherein:
Formula (a):
0.00 <{(substitution degree with -L ₂ -R ₂ ) + (substitution degree with -L ₃ -R ₃ ) + (substitution degree with -L ₆ -R ₆ )} ≦ 2.50   The content of the compound having the structure represented by the general formula (1) is 0.01 to 5 mass with respect to the aromatic or aliphatic carbamate substituted polymer having the structure represented by the general formula (2). The polymer composition according to any one of claims 1 to 3, wherein the polymer composition is in a range of%.   An optical film comprising the polymer composition according to any one of claims 1 to 4.   6. The optical film according to claim 5, which is a long film and has a slow axis in a range of 40 to 50 [deg.] With respect to the longitudinal direction.   A circularly polarizing plate, wherein the optical film according to claim 5 or 6 and a polarizer are bonded.   A display device comprising the optical film according to claim 5.

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