JP2009265295A - Retardation film, polarizing plate and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retardation film that improves the viewing angle of an IPS type liquid crystal display device having small variation in optical characteristics due to environmental change. <P>SOLUTION: The retardation film is a cellulose ester film of 20 to 50 μm in thickness which includes at least a first optical anisotropic layer and a second optical anisotropic layer, the first optical anisotropic layer having an in-surface retardation Ro of 0 to 10 nm and a thickness-directional retardation Rt of -400 to -80 nm and the second optical anisotropic layer containing cellulose ester having a hydroxyl group of cellulose substituted by acetyl group and an acyl group whose carbon atomicity is 3 to 5, the retardation film being characterized in that the degree A of substitution of the acetyl group and the degree B of substitution of the acyl group whose carbon atomicity is 3 to 5 satisfy expression (I) 2.0≤A+B≤3.0 and expression (II) 0<B and while the in-plane retardation Ro is 20 to 150 nm, the thickness-directional retardation Rt is 100 to 300 nm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a retardation film having an optically anisotropic layer made of liquid crystal, a polarizing plate using the retardation film, and a liquid crystal display device.

  As a liquid crystal display device, a liquid crystal display device using a so-called in-plane switching (IPS) mode in which a lateral electric field excellent in viewing angle characteristics is applied to the liquid crystal, or a liquid crystal having a negative dielectric anisotropy is vertically aligned. A vertical alignment (VA) mode in which alignment is divided by protrusions and slit electrodes formed in the panel has been proposed and put into practical use.

  In recent years, these panels have been developed not only for monitor applications but also for TV applications, and screen brightness has been greatly improved accordingly. For this reason, slight light leakage in the diagonally oblique incidence direction during black display, which has not been considered as a problem in these operation modes, has become apparent as a cause of deterioration in display quality.

  Many of the proposed methods for improving the viewing angle of the color tone and the black display are based on the birefringence anisotropy of the liquid crystal in the liquid crystal cell by using an optical compensation sheet such as a retardation film. Since this is an improved system, there is a problem in that light leakage based on the deviation from the orthogonal crossing angle of the polarization axes when the orthogonal polarizing plate is viewed obliquely cannot be sufficiently solved.

  Therefore, in Patent Document 1, a retardation layer formed by vertically aligning with an optical compensation sheet is provided on a support as an optically anisotropic layer, and by using an additive in the layer, not only a viewing angle but also a retardation is provided. Techniques have also been proposed for improving screen unevenness due to unevenness.

  In patent document 2, the technique which prescribed | regulated the characteristic of the cellulose-ester film used as the support body for providing an anisotropic layer is proposed.

However, these techniques are also not sufficient to cope with the unevenness of the screen caused by the environmental change of the support for providing the optically anisotropic layer, particularly the influence of the heat from the backlight and the humidity of the storage atmosphere. Furthermore, the enlargement of the screen of the liquid crystal display device finally revealed the alignment unevenness of the liquid crystal layer which is an optically anisotropic layer.
JP 2007-45993 A JP 2007-155972 A

  The present invention uses a retardation film having a small alignment unevenness of a liquid crystal layer that is durable to environmental changes, a retardation film that increases the front contrast ratio of a liquid crystal display device using the retardation film, and the retardation film. An object is to provide a polarizing plate and a liquid crystal display device.

  As a result of intensive studies to achieve the above object, the present inventors have found that the in-plane retardation Ro is 0 to 10 nm and the thickness direction retardation Rt is 400 to -80 nm. Along with the anisotropic layer, the inventors found that it is effective to control the substituent, degree of substitution and film thickness of the raw material cellulose ester of the cellulose ester film used for the retardation film, and completed the present invention. .

That is, the present invention has been achieved by the following means.
1. It includes at least a first optical anisotropic layer and a second optical anisotropic layer, an in-plane retardation Ro of the first optical anisotropic layer is 0 to 10 nm, and a letter in the thickness direction Film thickness 20 containing a cellulose ester in which Rd is -400 to -80 nm and the second optically anisotropic layer is obtained by substituting a hydroxyl group of cellulose with an acetyl group and an acyl group having 3 to 5 carbon atoms. A cellulose ester film of ˜50 μm, wherein the substitution degree A of the acetyl group and the substitution degree B of the acyl group having 3 to 5 carbon atoms satisfy the following formulas (I) and (II): A retardation film having a retardation Ro of 20 to 150 nm and a thickness direction retardation Rt of 100 to 300 nm.
Formula (I): 2.0 ≦ A + B ≦ 3.0
Formula (II): 0 <B
Ro = (nx−ny) × d
Rt = ((nx + ny) / 2−nz) × d
It is.
Where nx is the refractive index in the slow axis direction in the plane of the optically anisotropic layer, ny is the refractive index in the direction perpendicular to the slow axis in the plane of the optically anisotropic layer, and nz is optical. (The refractive index in the thickness direction of the anisotropic layer, d represents the thickness (nm) of the optical anisotropic layer, and the measurement wavelength of the refractive index is 590 nm.)
2. The first optically anisotropic layer is composed of a composition containing a rod-like liquid crystal compound, and the molecules of the rod-like liquid crystal compound are substantially perpendicular to the layer plane in the first optically anisotropic layer. 2. The retardation film as described in 1 above, which is fixed in an oriented state.
3. A polarizing plate comprising a polarizing plate sandwiched between two polarizing plate protective films, wherein at least one of the polarizing plate protective films is the retardation film described in 1 or 2 above.
4). 3. A liquid crystal display device using the retardation film as described in 1 or 2 above.

  According to the present invention, it is possible to obtain a retardation film which is durable to environmental changes and has a small alignment unevenness of a liquid crystal layer, a polarizing plate and a liquid crystal display device using the retardation film.

Hereinafter, the present invention will be described in more detail. In the present specification, when a numerical value represents a physical property value, a characteristic value, etc., the description “(numerical value 1) to (numerical value 2)” means “(numerical value 1) or more and (numerical value 2) or less”. . In the present specification, the description “(meth) acrylate” means “at least one of acrylate and methacrylate”. The same applies to “(meth) acrylic acid” and the like.
<The retardation film of the present invention>
The retardation film of the present invention comprises a first optically anisotropic layer having an in-plane retardation Ro of 0 to 10 nm and a thickness direction retardation Rt of 400 to -80 nm, and a predetermined cellulose ester. And a second optically anisotropic layer comprising a cellulose ester film having a thickness of 20 to 50 μm, an in-plane retardation Ro of 20 to 150 nm, and a thickness direction retardation Rt of 100 to 300 nm. It is characterized by that.

  According to the present inventors, Ro and Rt are linear functions of the film thickness from the definition, and even when it is expected to move linearly with respect to the environmental change, the thickness becomes less than 50 μm. Has found that the movement is off-linear.

  This is because the unevenness due to the environmental change was caused by the occurrence of non-uniformity due to the environmental change of the cellulose ester film. It is presumed that the ester film itself is easily homogenized, and as a result, unevenness is hardly observed.

  In addition, the details of the point that the front contrast is hardly lowered or the front contrast is improved when the retardation film of the present invention is used in a liquid crystal display device are unknown, It is presumed that the effect on the front contrast appears due to the decrease in reflection and scattering at the interface due to the close refractive index of.

The cellulose ester film of the present invention comprises cellulose and other additives.
<Cellulose ester>
First, the cellulose ester used as the raw material of the cellulose ester film used as a 2nd optically anisotropic layer in this invention is described.

  In the present invention, a cellulose ester film substantially consisting of a specific cellulose ester is used as the second optically anisotropic layer.

The cellulose ester is a mixed fatty acid ester of cellulose obtained by substituting a hydroxyl group of cellulose with an acetyl group and an acyl group having 3 to 5 carbon atoms, and the degree of substitution of the cellulose with a hydroxyl group is represented by the following formula ( It is a cellulose ester satisfying I) and (II).
Formula (I): 2.0 ≦ A + B ≦ 3.0
Formula (II): 0 <B
Here, in the formula, A and B represent the substitution degree of the acyl group substituted with the hydroxyl group of cellulose, A is the substitution degree of the acetyl group, and B is the substitution degree of the acyl group having 3 to 5 carbon atoms. is there.

  As long as the above formula is satisfied, two or more different cellulose esters may be mixed and used.

  Glucose units having β-1,4 bonds constituting cellulose have free hydroxyl groups at the 2nd, 3rd and 6th positions.

  Cellulose ester is a polymer obtained by esterifying some or all of these hydroxyl groups with an acyl group. The degree of acyl substitution means the proportion of cellulose esterified at each of the 2-position, 3-position and 6-position (100% esterification has a degree of substitution of 1).

  In the present invention, the total substitution degree (A + B) of hydroxyl groups A and B is 2.0 to 3.0, preferably 2.2 to 2.9, as shown in the above formula (I). And particularly preferably 2.40 to 2.85. Further, the substitution degree of B is a value exceeding 0, preferably 0.9 or more, particularly preferably 1.3 or more, as shown in the above formula (II).

  When A + B is less than 2.0, the hydrophilicity becomes strong and it is easy to be affected by environmental humidity. When B is 0 and becomes cellulose acetate, it becomes susceptible to environmental humidity.

  Further, 28% or more of B is preferably the substitution degree of the 6-position hydroxyl group, more preferably 30% or more is the substitution degree of the 6-position hydroxyl group, more preferably 31% or more, and particularly 32% or more is 6%. The degree of substitution of the coordinate hydroxyl group is preferred.

  Furthermore, the total substitution degree of A and B of the 6-position hydroxyl group of the cellulose ester is preferably 0.75 or more, more preferably 0.80 or more, and particularly preferably 0.85 or more.

  With these cellulose ester films, a solution for preparing a film having preferable solubility and filterability can be produced, and a good solution can be produced even in a non-chlorine organic solvent. Furthermore, it is possible to prepare a solution having a low viscosity and good filterability.

  The acyl group having 3 to 5 carbon atoms may be an aliphatic group or an aromatic hydrocarbon group, and is not particularly limited.

  These are, for example, cellulose alkylcarbonyl esters, alkenylcarbonyl esters, aromatic carbonyl esters, aromatic alkylcarbonyl esters, and the like, each of which may further have a substituted group.

  These preferred B include propionyl, butanoyl, pentanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, i-butanoyl, t-butanoyl, cyclohexanecarbonyl, oleoyl, benzoyl , Naphthylcarbonyl, cinnamoyl group, and the like.

  Among these, propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, oleoyl, benzoyl, naphthylcarbonyl, cinnamoyl group and the like are preferable. Particularly preferred are propionyl and butanoyl groups.

  Further, the substitution degree B is preferably 0.3 or more, more preferably 0.4 to 2.0 or less, further preferably 0.5 to 1.5, and particularly preferably 0.6 to 1.3.

  By setting the degree of substitution B within this range, it is possible to suppress physical deformation accompanying a decrease in Tg during high temperature storage and changes in optical characteristics during high humidity storage.

  Specific examples of the cellulose ester used in the present invention include cellulose acetate propionate and cellulose acetate butyrate.

The degree of substitution of the acetyl group, propionyl group and / or butyl group can be determined by calculation according to ASTM: D-817-96 (test method for cellulose acetate, etc.).
(Synthesis method of cellulose ester)
The basic principle of the cellulose ester synthesis method is described in Mita et al., Wood chemistry, 180-190 (Kyoritsu Shuppan, 1968). A typical synthesis method is a liquid phase acetylation method using a carboxylic acid anhydride-acetic acid-sulfuric acid catalyst.

  In order to obtain the cellulose ester, specifically, a cellulose raw material such as cotton linter or wood pulp is pretreated with an appropriate amount of acetic acid, and is then esterified by introducing it into a pre-cooled carboxylated mixed solution. The total acyl substitution degree at the 2nd, 3rd and 6th positions is approximately 3.00).

  The carboxylated mixed solution generally contains acetic acid as a solvent, carboxylic anhydride as an esterifying agent, and sulfuric acid as a catalyst. The carboxylic anhydride is usually used in a stoichiometric excess over the sum of the cellulose that reacts with it and the water present in the system.

  After completion of the esterification reaction, a neutralizing agent (for example, calcium, magnesium, iron, aluminum or zinc) is used for hydrolysis of excess carboxylic anhydride remaining in the system and neutralization of a part of the esterification catalyst. Of carbonate, acetate or oxide).

  Next, the obtained complete cellulose ester is saponified and aged by maintaining it at 50 to 90 ° C. in the presence of a small amount of an acetylation reaction catalyst (generally, remaining sulfuric acid) to obtain a desired degree of acyl substitution and degree of polymerization. To a cellulose ester having When the desired cellulose ester is obtained, the catalyst remaining in the system is completely neutralized using the neutralizing agent as described above, or the cellulose in water or dilute sulfuric acid without neutralization. The specific cellulose ester can be obtained by introducing an ester solution (or by adding water or dilute sulfuric acid into the cellulose ester solution) to separate the cellulose ester, washing and stabilizing treatment, etc. .

  In the cellulose ester film, the polymer component constituting the film is preferably substantially composed of the specific cellulose ester. “Substantially” means 55% by mass or more (preferably 70% by mass or more, more preferably 80% by mass or more) of the polymer component.

  The cellulose ester is preferably used in the form of particles. 90% by mass or more of the particles to be used preferably have a particle diameter of 0.5 to 5 mm. Moreover, it is preferable that 50 mass% or more of the particle | grains to be used have a particle diameter of 1-4 mm. The cellulose ester particles preferably have a shape as close to a sphere as possible.

  The degree of polymerization of the cellulose ester preferably used in the present invention is a viscosity average degree of polymerization, preferably 200 to 700, more preferably 250 to 550, still more preferably 250 to 400, and particularly preferably 250 to 350. The average degree of polymerization can be measured by the intrinsic viscosity method of Uda et al. (Kazuo Uda, Hideo Saito, “Journal of Textile Society”, 1962, Vol. 18, No. 1, pages 105-120). Further details are described in JP-A-9-95538.

  When the low molecular component is removed, the average molecular weight (degree of polymerization) is increased, but the viscosity is lower than that of a normal cellulose ester. Therefore, the cellulose ester from which the low molecular component is removed is useful.

  A cellulose ester having a small amount of low molecular components can be obtained by removing low molecular components from a cellulose ester synthesized by an ordinary method. The removal of low molecular components can be carried out by washing the cellulose ester with a suitable organic solvent.

  In addition, when manufacturing a cellulose ester with few low molecular components, it is preferable to adjust the sulfuric acid catalyst amount in an acetylation reaction to 0.5-25 mass parts with respect to 100 mass parts of cellulose esters.

  When the amount of the sulfuric acid catalyst is in the above range, a cellulose ester that is preferable also in terms of molecular weight distribution (uniform molecular weight distribution) can be synthesized. When used during the production of cellulose ester, the water content is preferably 2% by mass or less, more preferably 1% by mass or less, and particularly 0.7% by mass or less.

  In general, the cellulose ester contains water and is known to have a water content of 2.5 to 5% by mass. In order to make the moisture content of a cellulose ester into the said range, it is necessary to dry, The method is not specifically limited.

  The raw material cotton of cellulose ester and the synthesis method thereof are disclosed in JIII Journal of Technical Disclosure No. 2001-1745 (issued March 15, 2001, Invention Association) p. Raw material cotton and synthesis methods described in detail in 7-12 can be employed.

  The cellulose ester film according to the present invention can be obtained by preparing a cellulose ester solution in which the specific cellulose ester and, if necessary, an additive are dissolved in an organic solvent, and forming the film using the solution. .

(Other additives for the second optically anisotropic layer)
Additives that can be added to the cellulose ester solution include, for example, plasticizers, UV absorbers, deterioration inhibitors, retardation (optical anisotropy) developing agents, retardation (optical anisotropy) reducing agents, and wavelength dispersion. Examples thereof include regulators, fine particles, dyes, peeling accelerators and infrared absorbers.

  In the present invention, a retardation developer is used. Moreover, it is preferable to use at least one of a plasticizer, an ultraviolet absorber, a dye, and a peeling accelerator.

  They may be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, ultraviolet absorbers of 20 ° C. or lower and 20 ° C. or higher can be mixed and used, and plasticizers can also be mixed and used, for example, as described in JP-A No. 2001-151901.

  As the ultraviolet absorber, any type can be selected according to the purpose, and a salicylic acid ester-based, benzophenone-based, benzotriazole-based, benzoate-based, cyanoacrylate-based, nickel complex-based absorber or the like is used. Preferred are benzophenone series, benzotriazole series, and salicylic acid ester series.

  Examples of benzophenone ultraviolet absorbers include 2,4-dihydroxybenzophenone, 2-hydroxy-4-acetoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2′-di-hydroxy-4-methoxybenzophenone, 2, 2′-di-hydroxy-4,4′-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4- (2-hydroxy-3- And methacryloxy) propoxybenzophenone.

  As a benzotriazole ultraviolet absorber, 2 (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2 (2′-hydroxy-5′-tert-butylphenyl) ) Benzotriazole, 2 (2′-hydroxy-3 ′, 5′-di-tert-amylphenyl) benzotriazole, 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5 Examples include chlorobenzotriazole, 2 (2′-hydroxy-5′-tert-octylphenyl) benzotriazole, and the like.

  Examples of salicylic acid esters include phenyl salicylate, p-octylphenyl salicylate, and p-tert-butylphenyl salicylate.

  Among these exemplified ultraviolet absorbers, in particular, 2-hydroxy-4-methoxybenzophenone, 2,2′-di-hydroxy-4,4′-methoxybenzophenone, 2 (2′-hydroxy-3′-tert-butyl- 5'-methylphenyl) -5-chlorobenzotriazole, 2 (2'-hydroxy-5'-tert-butylphenyl) benzotriazole, 2 (2'-hydroxy-3 ', 5'-di-tert-amylphenyl) ) Benzotriazole, 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole is particularly preferred.

  As the ultraviolet absorber, it is preferable to use a combination of a plurality of absorbers having different absorption wavelengths because a high blocking effect can be obtained in a wide wavelength range. The ultraviolet absorber for liquid crystal is preferably one that is excellent in the ability to absorb ultraviolet light having a wavelength of 370 nm or less from the viewpoint of preventing deterioration of the liquid crystal and that has little absorption of visible light having a wavelength of 400 nm or more from the viewpoint of liquid crystal display properties.

  Particularly preferred ultraviolet absorbers are the benzotriazole compounds, benzophenone compounds, and salicylic acid ester compounds mentioned above. Among these, a benzotriazole-based compound is preferable because unnecessary coloring with respect to the cellulose ester is small.

  As for the ultraviolet absorber, JP-A-60-235852, JP-A-3-199201, JP-A-5-194789, JP-A-5-271471, JP-A-6-107854, JP-A-6-118233, JP-A-6-118233, 130226, 6-148430, 7-11055, 7-11056, 8-29619, 8-239509, and JP-A-2000-204173 can also be used. it can.

  0.001-5 mass% is preferable with respect to a cellulose ester, and, as for the addition amount of a ultraviolet absorber, 0.01-1 mass% is more preferable. If the addition amount is less than 0.001% by mass, the effect of addition cannot be sufficiently exhibited. If the addition amount exceeds 5% by mass, the ultraviolet absorber may bleed out to the film surface.

  Further, the ultraviolet absorber may be added simultaneously with the dissolution of the cellulose ester, or may be added to the dope after dissolution. In particular, a mode in which an ultraviolet absorbent solution is added to the dope immediately before casting using a static mixer or the like is preferable because the spectral absorption characteristics can be easily adjusted.

  The deterioration inhibitor can prevent cellulose triacetate and the like from deteriorating and decomposing. Examples of the deterioration preventing agent include butylamine, hindered amine compounds (JP-A-8-325537), guanidine compounds (JP-A-5-271471), benzotriazole-based UV absorbers (JP-A-6-235819), and benzophenone-based compounds. There are compounds such as UV absorbers (JP-A-6-118233).

  The plasticizer is preferably a phosphate ester or a carboxylic acid ester. The plasticizer may be triphenyl phosphate (TPP), tricresyl phosphate (TCP), cresyl diphenyl phosphate, octyl diphenyl phosphate, biphenyl diphenyl phosphate (BDP), trioctyl phosphate, tributyl phosphate, dimethyl phthalate (DMP) ), Diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP), diethyl hexyl phthalate (DEHP), triethyl O-acetylcitrate (OACTE), tributyl O-acetylcitrate ( OACTB), acetyl triethyl citrate, acetyl tributyl citrate, butyl oleate, methyl acetyl ricinoleate, dibutyl sebacate, tria Chin, tributyrin, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, and more preferably one selected from butyl phthalyl butyl glycolate.

  Furthermore, the plasticizer is preferably (di) pentaerythritol esters, glycerol esters, diglycerol esters.

  Examples of the peeling accelerator include ethyl esters of citric acid. Furthermore, as an infrared absorber, it describes in Unexamined-Japanese-Patent No. 2001-194522, for example.

  In the present invention, a dye for adjusting the hue may be added. The content of the dye is preferably from 10 to 1000 ppm, more preferably from 50 to 500 ppm, by mass ratio with respect to the cellulose ester. By containing the dye in this way, light piping of the cellulose ester film can be reduced, and yellowness can be improved.

  These compounds may be added together with the cellulose ester or the solvent during the preparation of the cellulose ester solution, or may be added during or after the solution preparation. Moreover, you may add to the ultraviolet absorber liquid added in-line.

  The dye used in the present invention is preferably a compound represented by the following general formula (1) or (2).

In formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are each a hydrogen atom, a hydroxyl group, an aliphatic group, an aromatic group, a heterocyclic group, a halogen atom atom, a cyano group, a nitro ^{group, -COR 9, -COOR 9, -NR} 9 R 10, -NR 10 COR 11, -NR 10 SO 2 R 11, -CONR 9 R 10, -SO 2 NR 9 R 10, ^{-COR 11, -SO 2 R 11,} -OCOR 11, -NR 9 CONR 10 R 11, represents a -CONHSO ² R ¹¹ or ^-SO 2 NHCOR ^{11, R 9} and ^{R 10} are each a hydrogen atom, an aliphatic group, An aromatic group or a heterocyclic group is represented, and R ¹¹ represents an aliphatic group, an aromatic group or a heterocyclic group. R ⁹ and R ¹⁰ may be linked to form a 5- or 6-membered ring, and R ¹ and R ² or R ² and R ³ may be linked to form a ring.

In Formula (2), R ²¹ , R ²³ and R ²⁴ are each a hydrogen atom, a hydroxyl group, a nitro group, a cyano group, an aliphatic group, an aromatic group, —COR ²⁹ , —COOR ²⁹ , —NR ²⁹ R ³⁰ , — represents NR ³⁰ COR ³¹ or _{^{-NR 30 SO 2 R 31, R}} 22 represents an aliphatic group or an aromatic ^{group, R 29} and ^{R 30} are the same meaning as ^{R 9} and ^{R 10} in formula (1) , R ³¹ has the same meaning as R ¹¹ in formula (1). However, one or more of R ²¹ , R ²² , R ²³ and R ²⁴ are groups other than hydrogen.

  Below, each group of General formula (1) is demonstrated in detail.

The aliphatic group represented by R ^{1 to} R ¹¹ is an alkyl group having 1 to 20 carbon atoms (for example, methyl, ethyl, n-butyl, isopropyl, 2-ethylhexyl, n-decyl, n-octadecyl), carbon number 1 to 20 cycloalkyl groups (for example, cyclopentyl, cyclohexyl) or allyl groups, substituents [for example, halogen atoms (for example, F, Cl, Br, I), hydroxyl groups, cyano groups, nitro groups, carboxylic acid groups , an aryl group having 6 to 10 carbon atoms (e.g., phenyl, naphthyl), amino group having 0 to 20 carbon atoms _{(e.g., NH 2, NHCH 3, N} (C 2 H 5) 2, N (C 4 H 9) ₂ , N (C ₈ H ₁₇ ) ₂ , anilino, 4-methoxyanilino), an amide group having 1 to 20 carbon atoms (for example, acetylamino, hexanoylamino, benzoylamino, Octadecanoylamino), a carbamoyl group having 1 to 20 carbon atoms (for example, unsubstituted carbamoyl, methylcarbamoyl, ethylcarbamoyl, octylcarbamoyl, hexadecylcarbamoyl), an ester group having 2 to 20 carbon atoms (for example, methoxycarbonyl, Ethoxycarbonyl, phenoxycarbonyl, n-butoxycarbonyl, dodecyloxycarbonyl), C1-C20 alkoxy group or aryloxy group (methoxy, ethoxy, butoxy, isopropoxy, benzyloxy, phenoxy, octadecyloxy), C1-C1 20 sulfonamide groups (for example, methanesulfonamide, ethanesulfonamide, butanesulfonamide, benzenesulfonamide, octanesulfonamide), sulfamoyl groups having 0 to 20 carbon atoms (examples) Unsubstituted sulfamoyl, methylsulfamoyl, butylsulfamoyl, decylsulfamoyl), 5- or 6-membered heterocycles (eg pyridyl, pyrazolyl, morpholino, piperidino, pyrrolino, benzoxazolyl)] You may have.

The aromatic group represented by R ^{1 to} R ¹¹ represents an aryl group having 6 to 10 carbon atoms (for example, phenyl or naphthyl), and a substituent [for example, a substituent that the above-described aliphatic group may have] In addition to the above-described groups, an alkyl group having 1 to 20 carbon atoms (for example, methyl, ethyl, butyl, t-butyl, octyl, etc.) may be included.

The heterocyclic group represented by R ^{1 to} R ¹¹ represents a 5- or 6-membered heterocyclic ring (for example, pyridine, piperidine, morpholine, pyrrolidine, pyrazole, pyrazolidine, pyrazoline, pyrazolone, benzoxazole), and a substituent (for example, Each group mentioned as a substituent which the above-mentioned aromatic group may have may have.

Examples of the 5- or 6-membered ring formed by connecting R ⁹ and R ¹⁰ include a morpholine ring, a piperidine ring, and a pyrrolidine ring. The ring formed by connecting R ¹ and R ² or R ² and R ³ is preferably a 5- or 6-membered ring (for example, a benzene ring or a phthalimide ring).

  Next, each group of the general formula (2) will be described.

The aliphatic group represented by R ^{21 to} R ²⁴ has the same meaning as the aliphatic group represented by R ^{1 to} R ¹¹ in the general formula (1), and the aromatic group represented by R ^{21 to} R ²⁴ is generally It is synonymous with the aromatic group which R < ¹ > -R < ¹¹ > in Formula (1) represents.

  The timing of adding these additives may be any timing of the dope preparation step, but a step of adding the additive to the final preparation step of the dope preparation step may be performed. Furthermore, the amount of each material added is not particularly limited as long as the function is manifested.

  Moreover, when a cellulose-ester film is a multilayer, the kind and addition amount of the additive of each layer may differ.

  For example, although it describes in Unexamined-Japanese-Patent No. 2001-151902 etc., these are techniques conventionally known. The glass transition point Tg measured by a dynamic viscoelasticity measuring device (Vibron: DVA-225 (manufactured by IT Measurement Control Co., Ltd.)) of cellulose ester film is selected according to the type and amount of these additives. More preferably, the glass transition point Tg is preferably 80 to 135 ° C.

  That is, the cellulose ester film according to the present invention preferably has a glass transition point Tg in the above range from the viewpoint of process suitability for polarizing plate processing and liquid crystal display device assembly.

Furthermore, regarding the additive, the Japan Institute of Invention and Innovation Technical Bulletin No. 2001-1745 (issued on March 15, 2001, Invention Association) p. Those described in detail after 16 can be used as appropriate.
(Retardation expression agent)
In the present invention, the retardation is adjusted so that the optical anisotropy of the cellulose ester film can be used as the second optical anisotropic layer. In order to realize a preferable retardation value, it is preferable to use a retardation developer.

  The retardation enhancer increases Rt by 0.11 or more per 1 micron film thickness by adding 1 part by mass with respect to 100 parts by mass of the polymer component containing cellulose ester.

  More preferably, the retardation is increased by 0.2 or more per micron of film thickness, more preferably 0.3 or more per micron of film thickness.

  Examples of the retardation enhancer that can be used in the present invention include those composed of rod-shaped or discotic compounds.

  As the rod-like or discotic compound, a compound having at least two aromatic rings can be used.

  The addition amount of the retardation developer composed of the rod-like compound is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymer component containing the cellulose ester. preferable.

  The discotic retardation enhancer is preferably used in the range of 0.05 to 30 parts by mass and in the range of 0.1 to 20 parts by mass with respect to 100 parts by mass of the polymer component containing the cellulose ester. More preferably, it is more preferably used in the range of 0.2 to 15 parts by mass, and most preferably in the range of 0.5 to 10 parts by mass.

  Since the discotic compound is superior to the rod-shaped compound in the Rt retardation expression property, it is preferably used particularly when a large Rt retardation is required.

  Two or more retardation developing agents may be used in combination.

  The retardation developer composed of a rod-like or discotic compound preferably has maximum absorption in the wavelength region of 250 to 400 nm, and preferably has substantially no absorption in the visible region.

  The discotic compound will be described. As the discotic compound, a compound having at least two aromatic rings can be used. In the present specification, the “aromatic ring” includes an aromatic hetero ring in addition to an aromatic hydrocarbon ring.

  The aromatic hydrocarbon ring is particularly preferably a 6-membered ring (that is, a benzene ring).

  The aromatic heterocycle is generally an unsaturated heterocycle. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring.

  Aromatic heterocycles generally have the most double bonds. As the hetero atom, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable.

  Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring , Pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring.

  As the aromatic ring, benzene ring, furan ring, thiophene ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, triazole ring, pyridine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring are preferable, In particular, a 1,3,5-triazine ring is preferably used.

  Specifically, for example, a compound disclosed in JP 2001-166144 A is preferably used as the discotic compound.

  The number of aromatic rings contained in the discotic compound is preferably 2 to 20, more preferably 2 to 12, still more preferably 2 to 8, and most preferably 2 to 6. preferable.

  The bonding relationship between two aromatic rings can be classified into (a) when forming a condensed ring, (b) when directly connecting with a single bond, and (c) when connecting via a linking group (for aromatic rings). , Spiro bonds cannot be formed). The connection relationship may be any of (a) to (c).

Examples of the condensed ring (a condensed ring of two or more aromatic rings) include an indene ring, a naphthalene ring, an azulene ring, a fluorene ring, a phenanthrene ring, an anthracene ring, an acenaphthylene ring, a biphenylene ring, a naphthacene ring, Pyrene ring, indole ring, isoindole ring, benzofuran ring, benzothiophene ring, indolizine ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring, purine ring, indazole ring, chromene ring, quinoline ring, isoquinoline Ring, quinolidine ring, quinazoline ring, cinnoline ring, quinoxaline ring, phthalazine ring, pteridine ring, carbazole ring, acridine ring, phenanthridine ring, xanthene ring, phenazine ring, phenothiazine ring, phenoxathiin ring, phenoxazine ring and thiant It includes emissions ring. Naphthalene ring, azulene ring, indole ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring and quinoline ring are preferred.
The single bond (b) is preferably a bond between carbon atoms of two aromatic rings. Two aromatic rings may be bonded by two or more single bonds to form an aliphatic ring or a non-aromatic heterocyclic ring between the two aromatic rings.
The linking group in (c) is also preferably bonded to carbon atoms of two aromatic rings. The linking group is preferably an alkylene group, an alkenylene group, an alkynylene group, —CO—, —O—, —NH—, —S—, or a combination thereof. Examples of linking groups composed of combinations are shown below. In addition, the relationship between the left and right in the following examples of the linking group may be reversed.
c1: -CO-O-
c2: —CO—NH—
c3: -alkylene-O-
c4: —NH—CO—NH—
c5: —NH—CO—O—
c6: —O—CO—O—
c7: -O-alkylene-O-
c8: -CO-alkenylene-
c9: -CO-alkenylene-NH-
c10: -CO-alkenylene-O-
c11: -alkylene-CO-O-alkylene-O-CO-alkylene-
c12: -O-alkylene-CO-O-alkylene-O-CO-alkylene-O-
c13: -O-CO-alkylene-CO-O-
c14: -NH-CO-alkenylene-
c15: -O-CO-alkenylene-
The aromatic ring and the linking group may have a substituent.

  Examples of substituents include halogen atoms (F, Cl, Br, I), hydroxyl groups, carboxyl groups, cyano groups, amino groups, nitro groups, sulfo groups, carbamoyl groups, sulfamoyl groups, ureido groups, alkyl groups, alkenyls. Group, alkynyl group, aliphatic acyl group, aliphatic acyloxy group, alkoxy group, alkoxycarbonyl group, alkoxycarbonylamino group, alkylthio group, alkylsulfonyl group, aliphatic amide group, aliphatic sulfonamido group, aliphatic substituted amino group An aliphatic substituted carbamoyl group, an aliphatic substituted sulfamoyl group, an aliphatic substituted ureido group, and a non-aromatic heterocyclic group.

  It is preferable that the alkyl group has 1 to 8 carbon atoms. A chain alkyl group is preferable to a cyclic alkyl group, and a linear alkyl group is particularly preferable. The alkyl group may further have a substituent (eg, hydroxy group, carboxy group, alkoxy group, alkyl-substituted amino group).

  Examples of alkyl groups (including substituted alkyl groups) include methyl, ethyl, n-butyl, n-hexyl, 2-hydroxyethyl, 4-carboxybutyl, 2-methoxyethyl and 2-methoxyethyl. A diethylaminoethyl group is included.

  The alkenyl group preferably has 2 to 8 carbon atoms. A chain alkenyl group is preferable to a cyclic alkenyl group, and a linear alkenyl group is particularly preferable. The alkenyl group may further have a substituent. Examples of the alkenyl group include a vinyl group, an allyl group, and a 1-hexenyl group.

  The alkynyl group preferably has 2 to 8 carbon atoms. A chain alkynyl group is preferable to a cyclic alkynyl group, and a linear alkynyl group is particularly preferable. The alkynyl group may further have a substituent. Examples of the alkynyl group include ethynyl group, 1-butynyl group and 1-hexynyl group.

  The number of carbon atoms in the aliphatic acyl group is preferably 1-10. Examples of the aliphatic acyl group include an acetyl group, a propanoyl group, and a butanoyl group.

  The number of carbon atoms in the aliphatic acyloxy group is preferably 1-10. Examples of the aliphatic acyloxy group include an acetoxy group.

  The number of carbon atoms of the alkoxy group is preferably 1-8. The alkoxy group may further have a substituent (eg, alkoxy group). Examples of the alkoxy group (including a substituted alkoxy group) include a methoxy group, an ethoxy group, a butoxy group, and a methoxyethoxy group.

  The number of carbon atoms of the alkoxycarbonyl group is preferably 2-10. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group.

  The number of carbon atoms of the alkoxycarbonylamino group is preferably 2-10. Examples of the alkoxycarbonylamino group include a methoxycarbonylamino group and an ethoxycarbonylamino group.

  The alkylthio group preferably has 1 to 12 carbon atoms. Examples of the alkylthio group include a methylthio group, an ethylthio group, and an octylthio group.

  The alkylsulfonyl group preferably has 1 to 8 carbon atoms. Examples of the alkylsulfonyl group include a methanesulfonyl group and an ethanesulfonyl group.

  The number of carbon atoms in the aliphatic amide group is preferably 1-10. Examples of the aliphatic amide group include an acetamide group.

  The number of carbon atoms of the aliphatic sulfonamide group is preferably 1-8. Examples of the aliphatic sulfonamido group include a methanesulfonamido group, a butanesulfonamido group, and an n-octanesulfonamido group.

  The number of carbon atoms of the aliphatic substituted amino group is preferably 1-10. Examples of the aliphatic substituted amino group include a dimethylamino group, a diethylamino group, and a 2-carboxyethylamino group.

  The number of carbon atoms in the aliphatic substituted carbamoyl group is preferably 2-10. Examples of the aliphatic substituted carbamoyl group include a methylcarbamoyl group and a diethylcarbamoyl group.

  The number of carbon atoms in the aliphatic substituted sulfamoyl group is preferably 1-8. Examples of the aliphatic substituted sulfamoyl group include a methylsulfamoyl group and a diethylsulfamoyl group.

  The number of carbon atoms in the aliphatic substituted ureido group is preferably 2-10. Examples of the aliphatic substituted ureido group include a methylureido group.

  Examples of the non-aromatic heterocyclic group include a piperidino group and a morpholino group.

  The molecular weight of the retardation developer composed of a discotic compound is preferably 300 to 800.

  In the present invention, in addition to the aforementioned discotic compound, a rod-shaped compound having a linear molecular structure can also be preferably used. The linear molecular structure means that the molecular structure of the rod-like compound is linear in the most thermodynamically stable structure.

  The most thermodynamically stable structure can be obtained by crystal structure analysis or molecular orbital calculation. For example, molecular orbital calculation can be performed using molecular orbital calculation software (eg, WinMOPAC2000, manufactured by Fujitsu Limited) to obtain a molecular structure that minimizes the heat of formation of a compound.

  The molecular structure being linear means that in the thermodynamically most stable structure obtained by calculation as described above, the angle of the main chain constituting the molecular structure is 140 degrees or more.

As the rod-shaped compound, those having at least two aromatic rings are preferable, and as the rod-shaped compound having at least two aromatic rings, a compound represented by the following general formula (3) is preferable.
Formula (3): Ar ¹ -L ¹ -Ar ²
In the general formula (3), Ar ¹ and Ar ² each independently represent an aryl group (aromatic hydrocarbon group), a substituted aryl group, an aromatic heterocyclic group, or a substituted aromatic heterocyclic group. . An aryl group and a substituted aryl group are more preferable than an aromatic heterocyclic group and a substituted aromatic heterocyclic group.

  The heterocycle of the aromatic heterocyclic group is generally unsaturated. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring.

  Aromatic heterocycles generally have the most double bonds. As a hetero atom, a nitrogen atom, an oxygen atom or a sulfur atom is preferable, and a nitrogen atom or a sulfur atom is more preferable.

  As the aromatic ring of the aromatic group, a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, a thiazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyrimidine ring and a pyrazine ring are preferable, and a benzene ring is particularly preferable. .

  Examples of the substituent of the substituted aryl group and the substituted aromatic heterocyclic group include a halogen atom (F, Cl, Br, I), a hydroxyl group, a carboxyl group, a cyano group, an amino group, an alkylamino group (eg, methyl). Amino group, ethylamino group, butylamino group, dimethylamino group), nitro group, sulfo group, carbamoyl group, alkylcarbamoyl group (eg, N-methylcarbamoyl group, N-ethylcarbamoyl group, N, N-dimethylcarbamoyl group) ), Sulfamoyl group, alkylsulfamoyl group (eg, N-methylsulfamoyl group, N-ethylsulfamoyl group, N, N-dimethylsulfamoyl group), ureido group, alkylureido group (eg, N -Methylureido group, N, N-dimethylureido group, N, N, N'-trimethylureido group), alkyl group (example Methyl, ethyl, propyl, butyl, pentyl, heptyl, octyl, isopropyl, s-butyl, t-amyl, cyclohexyl, cyclopentyl), alkenyl (eg, vinyl, allyl) Group, hexenyl group), alkynyl group (eg, ethynyl group, butynyl group), acyl group (eg, formyl group, acetyl group, butyryl group, hexanoyl group, lauryl group), acyloxy group (eg, acetoxy group, butyryloxy group, Hexanoyloxy group, lauryloxy group), alkoxy group (eg, methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, heptyloxy group, octyloxy group), aryloxy group (eg, phenoxy group), Alkoxycarbonyl group (eg, methoxycarbonyl group, ethoxycarbonyl group) Propoxycarbonyl group, butoxycarbonyl group, pentyloxycarbonyl group, heptyloxycarbonyl group), aryloxycarbonyl group (eg, phenoxycarbonyl group), alkoxycarbonylamino group (eg, butoxycarbonylamino group, hexyloxycarbonylamino group), Alkylthio group (eg, methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, heptylthio group, octylthio group), arylthio group (eg, phenylthio group), alkylsulfonyl group (eg, methylsulfonyl group, ethylsulfonyl group, Propylsulfonyl group, butylsulfonyl group, pentylsulfonyl group, heptylsulfonyl group, octylsulfonyl group), amide group (eg, acetamido group, butyramide group, hexylamide group, Laurylamide group) and non-aromatic heterocyclic groups (eg, morpholyl group, pyrazinyl group).

  Examples of the substituent of the substituted aryl group and the substituted aromatic heterocyclic group include a halogen atom, a cyano group, a carboxyl group, a hydroxyl group, an amino group, an alkyl-substituted amino group, an acyl group, an acyloxy group, an amide group, an alkoxycarbonyl group, Alkoxy groups, alkylthio groups and alkyl groups are preferred.

  The alkyl part and alkyl group of the alkylamino group, alkoxycarbonyl group, alkoxy group and alkylthio group may further have a substituent.

  Examples of alkyl moieties and substituents of alkyl groups include halogen atom, hydroxyl, carboxyl, cyano, amino, alkylamino group, nitro, sulfo, carbamoyl, alkylcarbamoyl group, sulfamoyl, alkylsulfamoyl group, ureido, alkylureido Group, alkenyl group, alkynyl group, acyl group, acyloxy group, acylamino group, alkoxy group, aryloxy group, alkoxycarbonyl group, aryloxycarbonyl group, alkoxycarbonylamino group, alkylthio group, arylthio group, alkylsulfonyl group, amide group And non-aromatic heterocyclic groups. As the substituent for the alkyl moiety and the alkyl group, a halogen atom, hydroxyl, amino, alkylamino group, acyl group, acyloxy group, acylamino group, alkoxycarbonyl group and alkoxy group are preferable.

In General Formula (3), L ¹ is a divalent linking group selected from an alkylene group, an alkenylene group, an alkynylene group, —O—, —CO—, and a group thereof.

  The alkylene group may have a cyclic structure. As the cyclic alkylene group, cyclohexylene is preferable, and 1,4-cyclohexylene is particularly preferable. As the chain alkylene group, a linear alkylene group is more preferable than a branched alkylene group.

  The number of carbon atoms of the alkylene group is preferably 1-20, more preferably 1-15, still more preferably 1-10, still more preferably 1-8, and most preferably 1-6. It is.

  The alkenylene group and the alkynylene group preferably have a chain structure rather than a cyclic structure, and more preferably have a linear structure rather than a branched chain structure.

  The alkenylene group and the alkynylene group preferably have 2 to 10 carbon atoms, more preferably 2 to 8, more preferably 2 to 6, still more preferably 2 to 4, and most preferably 2. (Vinylene or ethynylene).

  The arylene group preferably has 6 to 20 carbon atoms, more preferably 6 to 16, and still more preferably 6 to 12.

In the molecular structure of the general formula (3), the angle formed by Ar ¹ and Ar ² across L ¹ is preferably 140 degrees or more.

  The rod-like compound can be synthesized by a method described in the literature. As literature, Mol. Cryst. Liq. Cryst. 53, 229 (1979), 89, 93 (1982), 145, 111 (1987), 170, 43 (1989), J. Am. Am. Chem. Soc. 113, 1349 (1991), 118, 5346 (1996), 92, 1582 (1970); Org. Chem. 40, 420 pages (1975), Tetrahedron, 48, No. 16, page 3437 (1992).

  It is more preferable to use a rod-like compound represented by the following general formula (4) as the retardation developer. The compound represented by the general formula (4) will be described below.

In the general formula (4), R ³¹ , R ³² , R ³³ , R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ , R ³⁹ and R ⁴⁰ each independently represent a hydrogen atom or a substituent, and R ³¹ , R ³² , R ³³ , R ³⁴ and R ³⁵ each represents an electron donating group. R ³⁸ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an aryloxy group having 6 to 12 carbon atoms. Group, an alkoxycarbonyl group having 2 to 12 carbon atoms, an acylamino group having 2 to 12 carbon atoms, a cyano group, or a halogen atom.

In the general formula (4), R ³¹ , R ³² , R ³³ , R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ , R ³⁹ and R ⁴⁰ each independently represent a hydrogen atom or a substituent, and the substituent will be described later. The substituent T can be applied.

At least one of R ³¹ , R ³² , R ³³ , R ³⁴ and R ³⁵ represents an electron donating group. It is more preferable that one of R ³¹ , R ³³ or R ³⁵ is an electron donating group and R ³³ is an electron donating group.

  An electron donating group is one having a Hammett σp value of 0 or less. Rov. , 91, 165 (1991), and those having a Hammett σp value of 0 or less are preferably applicable, and those having −0.85 to 0 are more preferably used. Examples thereof include an alkyl group, an alkoxy group, an amino group, and a hydroxyl group.

  The electron donating group is preferably an alkyl group or an alkoxy group, more preferably an alkoxy group (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, particularly preferably carbon). 1 to 4).

R ³¹ is preferably a hydrogen atom or an electron donating group, more preferably an alkyl group, an alkoxy group, an amino group, or a hydroxyl group, and still more preferably an alkyl group having 1 to 4 carbon atoms or a carbon number 1 to 12 Particularly preferably an alkoxy group (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms), Most preferred is a methoxy group.

R ³² is preferably a hydrogen atom, an alkyl group, an alkoxy group, an amino group or a hydroxyl group, more preferably a hydrogen atom, an alkyl group or an alkoxy group, still more preferably a hydrogen atom or an alkyl group (preferably having a carbon number). 1 to 4, more preferably a methyl group), an alkoxy group (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, and particularly preferably 1 to carbon atoms). 4). Particularly preferred are a hydrogen atom, a methyl group and a methoxy group.

R ³³ is preferably a hydrogen atom or an electron donating group, more preferably a hydrogen atom, an alkyl group, an alkoxy group, an amino group, or a hydroxyl group, still more preferably an alkyl group or an alkoxy group, particularly preferably. An alkoxy group (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 4 carbon atoms). Most preferred are n-propoxy group, ethoxy group and methoxy group.

R ³⁴ is preferably a hydrogen atom or an electron donating group, more preferably a hydrogen atom, an alkyl group, an alkoxy group, an amino group, or a hydroxyl group, and still more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. And an alkoxy group having 1 to 12 carbon atoms (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 4 carbon atoms). Is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and most preferably a hydrogen atom, a methyl group, or a methoxy group.

R ³⁵ is preferably a hydrogen atom, an alkyl group, an alkoxy group, an amino group or a hydroxyl group, more preferably a hydrogen atom, an alkyl group or an alkoxy group, still more preferably a hydrogen atom or an alkyl group (preferably having a carbon number). 1 to 4 is more preferably a methyl group), an alkoxy group (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, and most preferably 1 to 4 carbon atoms). It is. Particularly preferred are a hydrogen atom, a methyl group and a methoxy group.

R ³⁶ , R ³⁷ , R ³⁹ and R ⁴⁰ are preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or a halogen atom, more preferably a hydrogen atom or a halogen atom. More preferably a hydrogen atom.

R ³⁸ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an aryloxy group having 6 to 12 carbon atoms. Group, an alkoxycarbonyl group having 2 to 12 carbon atoms, an acylamino group having 2 to 12 carbon atoms, a cyano group, or a halogen atom, which may have a substituent if possible. The group T can be applied.

R ³⁸ is preferably an alkyl group having 1 to 4 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an aryloxy group having 2 to 12 carbon atoms. And more preferably an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryloxy group having 6 to 12 carbon atoms, more preferably an alkoxy group having 1 to 12 carbon atoms (preferably Is preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and particularly preferably a methoxy group, an ethoxy group, n-propoxy group, iso-propoxy group and n-butoxy group.

  Of the general formula (4), the following general formula (4-A) is more preferable.

In the general formula (4-A), R ⁴¹ represents an alkyl group. R ³¹ , R ³² , R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ , R ³⁹ and R ⁴⁰ each independently represent a hydrogen atom or a substituent. R ³⁸ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an aryloxy group having 6 to 12 carbon atoms. Group, an alkoxycarbonyl group having 2 to 12 carbon atoms, an acylamino group having 2 to 12 carbon atoms, a cyano group, or a halogen atom.

In the general formula (4-A), R ³¹ , R ³² , R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ , R ³⁸ , R ³⁹ and R ⁴⁰ are respectively synonymous with those in the general formula (4), and The preferable range is also the same.

In the general formula (4-A), R ⁴¹ represents an alkyl group having 1 to 12 carbon atoms, and the alkyl group represented by R ⁴¹ may be linear or branched, and further has a substituent. However, it is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, still more preferably an alkyl group having 1 to 6 carbon atoms, and particularly preferably an alkyl group having 1 to 4 carbon atoms (for example, , Methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group and the like.

  Of the general formula (4), the following general formula (4-B) is more preferable.

In general formula (4-B), R ³¹ , R ³² , R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ , R ³⁹ and R ⁴⁰ each independently represent a hydrogen atom or a substituent. R ⁴¹ represents an alkyl group having 1 to 12 carbon atoms.

  X is an alkyl group having 1 to 4 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, a carbon number A 2-12 alkoxycarbonyl group, a C2-C12 acylamino group, a cyano group, or a halogen atom is represented.

In the general formula (4-B), R ³¹ , R ³² , R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ , R ³⁹ , and R ⁴⁰ are synonymous with those in the general formula (4), and preferred ranges are also included. It is the same.

In the general formula (4-B), R ⁴¹ has the same meaning as that in the general formula (4-A), and the preferred range is also the same.

  In general formula (4-B), X is an alkyl group having 1 to 4 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and 6 carbon atoms. Represents an aryloxy group having 12 to 12 carbon atoms, an alkoxycarbonyl group having 2 to 12 carbon atoms, an acylamino group having 2 to 12 carbon atoms, a cyano group, or a halogen atom.

When all of R ³¹ , R ³² , R ³⁴ and R ³⁵ are hydrogen atoms, X is preferably an alkyl group, alkynyl group, aryl group, alkoxy group or aryloxy group, more preferably an aryl group, alkoxy group Group, an aryloxy group, more preferably an alkoxy group (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 4 carbon atoms). And particularly preferably a methoxy group, a methoxy group, an n-propoxy group, an iso-propoxy group or an n-butoxy group.

When at least one of R ³¹ , R ³² , R ³⁴ , and R ³⁵ is a substituent, X is preferably an alkynyl group, an aryl group, an alkoxycarbonyl group, or a cyano group, more preferably an aryl group (preferably Is a C6-C12), cyano group, alkoxycarbonyl group (preferably C2-C12), more preferably aryl group (preferably C6-C12 aryl group, more preferably phenyl group). , P-cyanophenyl group and p-methoxyphenyl group), an alkoxycarbonyl group (preferably having a carbon number of 2-12, more preferably having a carbon number of 2-6, even more preferably having a carbon number of 2-4, particularly preferably methoxycarbonyl). , Ethoxycarbonyl, n-propoxycarbonyl), a cyano group, particularly preferably A phenyl group, a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, and a cyano group.

  Of the general formula (4), the following general formula (4-C) is more preferable.

In general formula (4-C), R ³¹ , R ³² , R ³⁴ , R ³⁵ , R ⁴¹ and X have the same meanings as those in general formula (4-B), and preferred ranges are also the same.

  Among the compounds represented by the general formula (4), a compound represented by the following general formula (4-D) is more preferable.

In general formula (4-D), R ³² , R ³⁴ and R ³⁵ have the same meanings as those in general formula (4-C), and preferred ranges thereof are also the same. R ⁵¹ and R ⁵² are each independently an alkyl group having 1 to 4 carbon atoms. X ¹ is an aryl group having 6 to 12 carbon atoms, an alkoxycarbonyl group having 2 to 12 carbon atoms, or a cyano group.

R ⁵¹ represents an alkyl group having 1 to 4 carbon atoms, preferably an alkyl group having 1 to 3 carbon atoms, and more preferably an ethyl group or a methyl group.

R ⁵² represents an alkyl group having 1 to 4 carbon atoms, preferably an alkyl group having 1 to 3 carbon atoms, more preferably an ethyl group or a methyl group, and still more preferably a methyl group.

X ¹ is an aryl group having 6 to 12 carbon atoms, an alkoxycarbonyl group having 2 to 12 carbon atoms, or a cyano group, preferably an aryl group having 6 to 10 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, or a cyano group. More preferably a phenyl group, a p-cyanophenyl group, a p-methoxyphenyl group, a methoxycarbonyl, an ethoxycarbonyl, an n-propoxycarbonyl, a cyano group, and still more preferably a phenyl group, a methoxycarbonyl group, an ethoxycarbonyl group, n-propoxycarbonyl group and cyano group.

  Of the general formula (4), the following general formula (4-E) is most preferable.

In the general formula (4-E), R ^{32 ′} , R ^{34 ′} and R ^{35 ′} each independently represent a hydrogen atom or a substituent, and any one is a group represented by —OR ^43. (R ⁴³ is an alkyl group having 1 to 4 carbon atoms). The ranges of substituents represented by R ^{32 ′} , R ^{34 ′} and R ^{35 ′} and preferred ranges thereof are the same as described above. R ⁵¹ , R ⁵² , and X ¹ are synonymous with those in formula (4-D), and preferred ranges are also the same.

In General Formula (4-E), any one of R ^{32 ′} , R ^{34 ′} and R ^{35 ′} is a group represented by —OR ⁴³ (R ⁴³ is an alkyl group having 1 to 4 carbon atoms). ), Preferably R ^{34 ′} and R ^{35 ′} are groups represented by —OR ⁴³ , and more preferably R ^{34 ′} is a group represented by —OR ⁴³ .

R ⁴³ represents an alkyl group having 1 to 4 carbon atoms, preferably an alkyl group having 1 to 3 carbon atoms, more preferably an ethyl group or a methyl group, and still more preferably a methyl group.

  The aforementioned substituent T will be described below.

  Examples of the substituent T include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms such as methyl, ethyl, iso-propyl, tert-butyl, and n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2 to 8, for example, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), an alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2-8, for example, propargyl, 3-pentynyl, etc.), aryl groups (preferably having 6-30 carbon atoms) More preferably, it has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyl, p-methylphenyl, naphthyl and the like, and a substituted or unsubstituted amino group (preferably having 0 to 0 carbon atoms). 20, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, etc.), an alkoxy group (preferably having a carbon number) 1 to 20, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy, ethoxy, butoxy, etc.), an aryloxy group (preferably 6 to 20 carbon atoms, more Preferably it has 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy, 2-naphthyloxy and the like. An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include acetyl, benzoyl, formyl, and pivaloyl). An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, etc.), an aryloxycarbonyl group ( Preferably it has 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, and examples thereof include phenyloxycarbonyl, etc.), an acyloxy group (preferably 2 to 20 carbon atoms, More preferably, it has 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms. Nzoyloxy and the like. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino), alkoxycarbonylamino group (Preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino), aryloxycarbonylamino group (preferably having carbon number) 7 to 20, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino, and the like, and sulfonylamino groups (preferably 1 to 20 carbon atoms, more preferably Has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms. And sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl and methylsulfamoyl). , Dimethylsulfamoyl, phenylsulfamoyl, etc.), a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl). , Methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio, Ethylthio etc.), arylthio group (preferably Has 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, and a sulfonyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl, tosyl, etc.), sulfinyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably Has 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms). For example, ureido, methylureido, phenylureido, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms) More preferably, it is C1-C16, Most preferably, it is C1-C12, for example, diethyl phosphoric acid amide, phenylphosphoric acid amide etc. are mentioned. ), Hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, Heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, specifically, for example, imidazolyl, pyridyl, quinolyl, furyl, piperidyl , Morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, and particularly preferably 3 to 24 carbon atoms). For example, trimethylsilyl, triphenylsilyl, etc.) . These substituents may be further substituted.

  Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

  Hereinafter, the compound represented by the general formula (4) will be described in detail with specific examples, but the present invention is not limited to the following specific examples.

  The compound represented by the general formula (4) can be synthesized by a general ester reaction of a substituted benzoic acid and a phenol derivative, and any reaction may be used as long as it is an ester bond forming reaction. Examples thereof include a method of converting a substituted benzoic acid to an acid halide and then condensing with phenol, a method of dehydrating condensation of a substituted benzoic acid and a phenol derivative using a condensing agent or a catalyst, and the like.

  In view of the production process and the like, a method in which the substituted benzoic acid is functionally converted to an acid halide and then condensed with phenol is preferable.

  Reaction solvents include hydrocarbon solvents (preferably toluene and xylene), ether solvents (preferably dimethyl ether, tetrahydrofuran, dioxane, etc.), ketone solvents, ester solvents, acetonitrile, dimethylformamide, dimethyl Acetamide or the like can be used.

  These solvents may be used alone or in admixture of several kinds, and preferred reaction solvents are toluene, acetonitrile, dimethylformamide and dimethylacetamide.

  The reaction temperature is preferably 0 to 150 ° C, more preferably 0 to 100 ° C, still more preferably 0 to 90 ° C, and particularly preferably 20 ° C to 90 ° C.

  In this reaction, it is preferable not to use a base. When a base is used, either an organic base or an inorganic base may be used, preferably an organic base such as pyridine, tertiary alkylamine (preferably triethylamine, ethyldiisopropyl). Pyramine and the like).

Two or more rod-shaped compounds having a maximum absorption wavelength (λmax) shorter than 250 nm in the ultraviolet absorption spectrum of the solution may be used in combination.
(Matting agent fine particles)
It is preferable to add fine particles as a matting agent to the cellulose ester film of the present invention. The fine particles used in the present invention 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, silica Mention may be made of magnesium and calcium phosphates.

  Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable. The fine particles of silicon dioxide preferably have a primary average particle diameter of 20 nm or less and an apparent specific gravity of 70 g / liter or more.

  Those having an average primary particle size as small as 5 to 16 nm are more preferred because they can reduce the haze of the film. The apparent specific gravity is preferably 90 to 200 g / liter or more, and more preferably 100 to 200 g / liter or more.

  A larger apparent specific gravity is preferable because a high-concentration dispersion can be produced, and haze and aggregates are improved.

  When the silicon dioxide fine particles are used, the amount used is preferably 0.01 to 0.3 parts by mass with respect to 100 parts by mass of the polymer component containing cellulose ester.

  These fine particles usually form secondary particles having an average particle diameter of 0.1 to 3.0 μm, and these fine particles are present as aggregates of primary particles in the film, and 0.1 to 0.1 μm on the film surface. An unevenness of 3.0 μm is formed.

  The secondary average particle size is preferably from 0.2 μm to 1.5 μm, more preferably from 0.4 μm to 1.2 μm, and most preferably from 0.6 μm to 1.1 μm.

  When it is larger than 1.5 μm, the haze becomes strong, and when it is smaller than 0.2 μm, the effect of preventing stain is reduced.

  The primary and secondary particle diameters are determined by observing the particles in the film with a scanning electron microscope and using the diameter of a circle circumscribing the particles as the particle diameter. Also, 200 particles are observed at different locations, and the average value is taken as the average particle diameter.

  As fine particles of silicon dioxide, for example, commercially available products such as Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (above Nippon Aerosil Co., Ltd.) can be used.

  Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (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 diameter of 20 nm or less and an apparent specific gravity of 70 g / liter or more, and the coefficient of friction is maintained while keeping the turbidity of the optical film low. It is particularly preferable because it has a great effect of reducing the effect.

  In order to obtain a cellulose ester film having particles having a small secondary average particle size in the present invention, several methods are conceivable when preparing a fine particle dispersion.

  For example, there is a method in which a fine particle dispersion liquid prepared by stirring and mixing a solvent and fine particles is prepared in advance, and this fine particle dispersion solution is added to a small amount of a separately prepared cellulose ester solution, stirred and dissolved, and further mixed with the main cellulose ester dope solution. .

  This method is a preferable preparation method in that the dispersibility of the silicon dioxide fine particles is good and the silicon dioxide fine particles are more difficult to reaggregate. In addition, after adding a small amount of cellulose ester to the solvent and dissolving with stirring, add the fine particles to this and disperse with a disperser to make this fine particle additive solution, and mix this fine particle additive solution with the dope solution using an in-line mixer. There is also a way to do it.

  Although this invention is not limited to these methods, 5-30 mass% is preferable, as for the density | concentration of silicon dioxide when silicon dioxide microparticles | fine-particles are mixed and disperse | distributed with a solvent etc., 10-25 mass% is more preferable, 15-20 Mass% is most preferred.

A higher dispersion concentration is preferable because the liquid turbidity with respect to the added amount is lowered, and haze and aggregates are improved. The addition amount of the matting agent in the final cellulose ester dope solution is preferably 0.01 to 1.0 g per 1 m ² , more preferably 0.03 to 0.3 g, and most preferably 0.08 to 0.16 g. preferable.

  The solvent used is preferably lower alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol and the like. Although it does not specifically limit as solvents other than a lower alcohol, It is preferable to use the solvent used at the time of film forming of a cellulose ester.

  Next, the organic solvent in which the cellulose ester according to the present invention is dissolved will be described.

In the present invention, any of a chlorinated solvent containing a chlorinated organic solvent as a main solvent and a non-chlorinated solvent not containing a chlorinated organic solvent can be used as the organic solvent.
(Chlorine solvent)
In preparing the cellulose ester solution according to the present invention, a chlorinated organic solvent is preferably used as the main solvent.

  In the present invention, the type of the chlorinated organic solvent is not particularly limited as long as the object can be achieved within the range in which the cellulose ester can be dissolved and solution casting can be performed.

  These chlorinated organic solvents are preferably dichloromethane and chloroform. Particularly preferred is dichloromethane. In addition, there is no particular problem in mixing an organic solvent other than the chlorinated organic solvent. In that case, it is necessary to use at least 50% by mass of dichloromethane in the total amount of the organic solvent.

  Other organic solvents used in combination with the chlorinated organic solvent in the present invention will be described below. That is, as another preferable organic solvent, a solvent selected from esters, ketones, ethers, alcohols, hydrocarbons and the like having 3 to 12 carbon atoms is preferable.

  Esters, ketones, ethers and alcohols may have a cyclic structure. A compound having two or more functional groups of esters, ketones and ethers (that is, —O—, —CO— and COO—) can also be used as a solvent. For example, other functional groups such as alcoholic hydroxyl groups can be used. You may have at the same time.

  In the case of a solvent having two or more types of functional groups, the number of carbon atoms may be within the specified range of the compound having any functional group. Examples of esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate.

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

  Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole. Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol.

  The alcohol used in combination with the chlorinated organic solvent may be linear, branched or cyclic, and among them, saturated aliphatic hydrocarbon is preferable. The hydroxyl group of the alcohol may be any of primary to tertiary.

  Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, 1-pentanol, 2-methyl-2-butanol and cyclohexanol. As the alcohol, fluorine-based alcohol is also used. Examples thereof include 2-fluoroethanol, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol and the like.

  Furthermore, the hydrocarbon may be linear, branched or cyclic. Either aromatic hydrocarbons or aliphatic hydrocarbons can be used. The aliphatic hydrocarbon may be saturated or unsaturated.

  Examples of hydrocarbons include cyclohexane, hexane, benzene, toluene and xylene.

Examples of combinations of chlorinated organic solvents and other organic solvents include the following compositions, but are not limited thereto.
Dichloromethane / methanol / ethanol / butanol (80/10/5/5, parts by mass),
Dichloromethane / acetone / methanol / propanol (80/10/5/5, parts by mass),
Dichloromethane / methanol / butanol / cyclohexane (80/10/5/5, parts by mass),
Dichloromethane / methyl ethyl ketone / methanol / butanol (80/10/5/5, parts by mass),
・ Dichloromethane / acetone / methyl ethyl ketone / ethanol / isopropanol (75/8/5/5/7, parts by mass)
・ Dichloromethane / cyclopentanone / methanol / isopropanol (80/7/5/8, part by mass)
Dichloromethane / methyl acetate / butanol (80/10/10, parts by mass),
Dichloromethane / cyclohexanone / methanol / hexane (70/20/5/5, parts by mass)
Dichloromethane / methyl ethyl ketone / acetone / methanol / ethanol (50/20/20/5/5, parts by mass),
Dichloromethane / 1, 3 dioxolane / methanol / ethanol (70/20/5/5, parts by mass),
Dichloromethane / dioxane / acetone / methanol / ethanol (60/20/10/5/5, parts by mass),
Dichloromethane / acetone / cyclopentanone / ethanol / isobutanol / cyclohexane (65/10/10/5/5/5, parts by mass)
Dichloromethane / methyl ethyl ketone / acetone / methanol / ethanol (70/10/10/5/5, parts by mass),
Dichloromethane / acetone / ethyl acetate / ethanol / butanol / hexane (65/10/10/5/5/5, parts by mass),
Dichloromethane / methyl acetoacetate / methanol / ethanol (65/20/10/5, parts by mass),
Dichloromethane / cyclopentanone / ethanol / butanol (65/20/10/5, parts by mass),
And so on.
(Non-chlorine solvent)
Next, the non-chlorine organic solvent that is preferably used in preparing the cellulose ester solution according to the present invention will be described.

  In the present invention, the non-chlorine organic solvent is not particularly limited as long as the object can be achieved as long as the cellulose ester can be dissolved and solution casting can be performed.

  The non-chlorine organic solvent used in the present invention is preferably a solvent selected from esters, ketones and ethers having 3 to 12 carbon atoms.

  The ester, ketone and ether may have a cyclic structure. A compound having two or more functional groups of esters, ketones and ethers (that is, —O—, —CO— and COO—) can also be used as a main solvent, and other compounds such as alcoholic hydroxyl groups can be used. It may have a functional group.

  In the case of the main solvent having two or more kinds of functional groups, the number of carbon atoms may be within the specified range of the compound having any functional group.

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

  Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and methylcyclohexanone. Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole.

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

  The non-chlorine organic solvent used in the above cellulose ester is selected from the various viewpoints described above, and is preferably as follows.

  That is, the non-chlorine solvent is preferably a mixed solvent containing the non-chlorine organic solvent as a main solvent, and is a mixed solvent of three or more different solvents, wherein the first solvent is methyl acetate, ethyl acetate, At least one selected from methyl formate, ethyl formate, acetone, dioxolane, and dioxane, or a mixture thereof; the second solvent is selected from ketones having 4 to 7 carbon atoms or acetoacetate; The solvent is a mixed solvent selected from alcohols or hydrocarbons having 1 to 10 carbon atoms, more preferably alcohols having 1 to 8 carbon atoms.

  Note that when the first solvent is a mixed liquid of two or more kinds of solvents, the second solvent may be omitted. The first solvent is more preferably methyl acetate, acetone, methyl formate, ethyl formate, or a mixture thereof, and the second solvent is preferably methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl acetyl acetate, or a mixed solvent thereof. It may be.

  The alcohol as the third solvent may be linear, branched or cyclic, and is preferably a saturated aliphatic hydrocarbon.

  The hydroxyl group of the alcohol may be any of primary to tertiary. Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, 1-pentanol, 2-methyl-2-butanol and cyclohexanol.

  As the alcohol, fluorine-based alcohol is also used. Examples thereof include 2-fluoroethanol, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol and the like.

  Furthermore, the hydrocarbon may be linear, branched or cyclic. Either aromatic hydrocarbons or aliphatic hydrocarbons can be used.

  The aliphatic hydrocarbon may be saturated or unsaturated. Examples of hydrocarbons include cyclohexane, hexane, benzene, toluene and xylene.

  These alcohols and hydrocarbons as the third solvent may be used alone or in combination of two or more, and are not particularly limited.

  As the third solvent, preferred specific compounds include alcohol, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and cyclohexanol, cyclohexane, hexane, Are methanol, ethanol, 1-propanol, 2-propanol, 1-butanol.

  The mixing ratio of the above three types of mixed solvents is 20 to 95% by mass for the first solvent, 2 to 60% by mass for the second solvent, and 2 to 30% by mass for the third solvent in the total amount of the mixed solvent. The first solvent is preferably 30 to 90% by mass, the second solvent is 3 to 50% by mass, and the third alcohol is preferably 3 to 25% by mass. .

  In particular, it is preferable that the first solvent is 30 to 90% by mass, the second solvent is 3 to 30% by mass, and the third solvent is alcohol and 3 to 15% by mass.

The non-chlorine-based organic solvent used in the present invention described above is more specifically described in JIII Journal of Technical Disclosure No. 2001-1745 (issued March 15, 2001, Invention Association) p. 12-16. Although the preferable combination of the said non-chlorine type | system | group organic solvent is mentioned below, it is not limited to these.
-Methyl acetate / acetone / methanol / ethanol / butanol (75/10/5/5/5, parts by mass),
-Methyl acetate / acetone / methanol / ethanol / propanol (75/10/5/5/5, parts by mass),
Methyl acetate / acetone / methanol / butanol / cyclohexane (75/10/5/5/5, parts by mass),
・ Methyl acetate / acetone / ethanol / butanol (81/8/7/4, parts by mass)
・ Methyl acetate / acetone / ethanol / butanol (82/10/4/4, parts by mass)
・ Methyl acetate / acetone / ethanol / butanol (80/10/4/6, part by mass)
Methyl acetate / methyl ethyl ketone / methanol / butanol (80/10/5/5, parts by mass),
-Methyl acetate / acetone / methyl ethyl ketone / ethanol / isopropanol (75/8/5/5/7, parts by mass)
-Methyl acetate / cyclopentanone / methanol / isopropanol (80/7/5/8, parts by mass),
-Methyl acetate / acetone / butanol (85/10/5, parts by mass),
Methyl acetate / cyclopentanone / acetone / methanol / butanol (60/15/14/5/6, parts by mass),
-Methyl acetate / cyclohexanone / methanol / hexane (70/20/5/5, parts by mass)
Methyl acetate / methyl ethyl ketone / acetone / methanol / ethanol (50/20/20/5/5, parts by mass),
Methyl acetate / 1,3-dioxolane / methanol / ethanol (70/20/5/5, parts by mass),
Methyl acetate / dioxane / acetone / methanol / ethanol (60/20/10/5/5, parts by mass),
Methyl acetate / acetone / cyclopentanone / ethanol / isobutanol / cyclohexane (65/10/10/5/5/5, parts by mass),
Methyl formate / methyl ethyl ketone / acetone / methanol / ethanol (50/20/20/5/5, parts by mass),
-Methyl formate / acetone / ethyl acetate / ethanol / butanol / hexane (65/10/10/5/5/5, parts by mass)
Acetone / methyl acetoacetate / methanol / ethanol (65/20/10/5, parts by mass)
Acetone / cyclopentanone / ethanol / butanol (65/20/10/5, parts by mass)
Acetone / 1,3-dioxolane / ethanol / butanol (65/20/10/5, parts by mass)
1,3-dioxolane / cyclohexanone / methyl ethyl ketone / methanol / butanol (55/20/10/5/5/5, parts by mass)
And so on.

Furthermore, the cellulose ester solution prepared by the following method can also be used.
A method of preparing a cellulose ester solution with methyl acetate / acetone / ethanol / butanol (81/8/7/4, parts by mass), adding 2 parts by weight of butanol after filtration and concentration, and methyl acetate / acetone / ethanol / A method of preparing a cellulose ester solution with butanol (84/10/4/2, parts by mass), adding 4 parts by weight of butanol after filtration and concentration, and methyl acetate / acetone / ethanol (84/10/6, parts by mass) In addition to the non-chlorine organic solvent, dichloromethane is used in an amount of 10% by mass or less of the total organic solvent amount. You may make it contain.
(Characteristics of cellulose ester solution)
When producing the cellulose ester film by the solution casting film forming method, the cellulose ester solution to be used is a solution obtained by dissolving cellulose ester in the organic solvent at a concentration of 10 to 30% by mass. It is preferable at the point of film | membrane suitability, More preferably, it is 13-27 mass%, Most preferably, it is 15-25 mass%. The cellulose ester solution having these concentrations may be prepared by dissolving the cellulose ester so as to have a predetermined concentration, or after preparing a low-concentration solution (for example, 9 to 14% by mass) in advance, concentration described later. It is good also as a predetermined high concentration solution through a process. Furthermore, after preparing a high concentration cellulose ester solution in advance, a predetermined low concentration cellulose ester solution may be obtained by adding various additives.

  In the case of producing the cellulose ester film by a solution casting film forming method, in a diluted solution in which the cellulose ester is dissolved at a concentration of 0.1 to 5% by mass in an organic solvent having the same composition as the cellulose ester solution, The aggregate molecular weight of the cellulose ester is preferably from 150,000 to 15 million from the viewpoint of improving the peelability.

  More preferably, the associated molecular weight is 180,000 to 9 million. This associated molecular weight can be determined by a static light scattering method. In this case, it is preferable to dissolve so that the inertial square radius required at the same time is 10 to 200 nm.

A more preferable inertial square radius is 20 to 200 nm. Furthermore, it is preferable to dissolve so that the second virial coefficient is −2 × 10 ⁻⁴ to + 4 × 10 ^−4, and more preferably, the second virial coefficient is −2 × 10 ⁻⁴ to + 2 × 10 ^−4. It is.

  Here, the definition of the association molecular weight, the inertial square radius, and the second virial coefficient will be described. These are measured using the static light scattering method according to the following method.

  The measurement is performed in a dilute region for the convenience of the apparatus, but these measured values reflect the behavior of the dope in the high concentration region.

  First, a cellulose ester is dissolved in a solvent used for the dope to prepare a 0.1 mass%, 0.2 mass%, 0.3 mass%, and 0.4 mass% solution.

  In order to prevent moisture absorption, the cellulose ester dried at 120 ° C. for 2 hours is used at 25 ° C. and 10% RH. The dissolution method is carried out according to the method employed at the time of dope dissolution (room temperature dissolution method, cooling dissolution method, high temperature dissolution method).

  Subsequently, these solutions and the solvent are filtered through a 0.2 μm filter made of tetrafluoroethylene (manufactured by DuPont). The filtered solution is measured for static light scattering at intervals of 10 degrees from 30 degrees to 140 degrees at 25 ° C. using a light scattering measuring device (DLS-700 manufactured by Otsuka Electronics Co., Ltd.).

The obtained data is analyzed by the BERRY plot method. In addition, the refractive index required for this analysis uses the value of the solvent calculated | required with the Abbe refractive system, and the refractive index gradient (dn / dc) uses the differential refractometer (Otsuka Electronics Co., Ltd. product DRM-1021). Measure using the solvent and solution used for light scattering measurement.
(Dope preparation)
Next, preparation of a cellulose ester solution (dope) will be described. The method for dissolving the cellulose ester is not particularly limited, and may be room temperature, and further, a cooling dissolution method or a high temperature dissolution method, and further a combination thereof.

  Regarding these, for example, JP-A-5-163301, JP-A-61-106628, JP-A-58-127737, JP-A-9-95544, JP-A-10-95854, JP-A-10-45950, JP 2000-53784, JP 11-322946, JP 11-322947, JP 2-276830, JP 2000-273239, JP 11-71463, JP 04-259511, Special JP 2000-273184, JP-A-11-323017, JP-A-11-302388, etc. describe methods for preparing cellulose ester solutions.

  The above-described method for dissolving these cellulose esters in an organic solvent is applicable to the present invention as long as it is within the scope of the present invention.

  For details of these, particularly for non-chlorine-based solvent systems, the Japan Society of Invention and Innovation Technical Bulletin No. 2001-1745 (issued March 15, 2001, Invention Association) p. It is carried out in the manner described in detail in 22-25.

  Further, the cellulose ester dope solution according to the present invention is usually subjected to solution concentration and filtration, and similarly, the Japan Institute of Invention and Innovation Technical Report No. 2001-1745 (issued March 15, 2001, Japan Institute of Invention) p. 25 in detail.

  In addition, when it melt | dissolves at high temperature, it is the case where it is more than the boiling point of the organic solvent to be used, and in that case, it uses in a pressurized state.

  It is preferable that the cellulose ester solution has a viscosity and a dynamic storage elastic modulus within the ranges described below because it is easy to cast. 1 ml of the sample solution is measured with a rheometer (CLS 500) using Steel Cone (both manufactured by TA Instruments) having a diameter of 4 cm / 2 °.

The measurement conditions are Oscillation Step / TemperatureRo Ramp, measured by varying the range from 40 ° C to -10 ° C at 2 ° C / min, static non-Newtonian viscosity n ^* (Pa · s) at 40 ° C, and storage elasticity at 5 ° C. The rate G ′ (Pa) is obtained.

  The sample solution is preliminarily kept at the measurement start temperature until the liquid temperature becomes constant, and then the measurement is started. In the present invention, the viscosity at 40 ° C. is 1 to 400 Pa · s, the dynamic storage elastic modulus at 15 ° C. is preferably 500 Pa or more, and more preferably the viscosity at 40 ° C. is 10 to 200 Pa · s. And the dynamic storage elastic modulus in 15 degreeC is 100-1 million.

  Furthermore, it is preferable that the dynamic storage elastic modulus at a low temperature is large. For example, when the casting support is −5 ° C., the dynamic storage elastic modulus is preferably 10,000 to 1,000,000 Pa at −5 ° C. When the body is at −50 ° C., the dynamic storage elastic modulus at −50 ° C. is preferably 10,000 to 5 million Pa.

  In the present invention, since the above-mentioned specific cellulose ester is used, it is characterized in that a high concentration dope is obtained, and a cellulose ester solution having a high concentration and excellent stability can be obtained without relying on a means of concentration. can get.

  Furthermore, in order to make it easy to melt | dissolve, after making it melt | dissolve at a low density | concentration, you may concentrate using a concentration means.

  The concentration method is not particularly limited. For example, the low-concentration solution is guided between the cylindrical body and the rotation trajectory of the outer periphery of the rotating blade rotating in the circumferential direction, and the temperature between the solution and the solution. A method of obtaining a high-concentration solution while evaporating the solvent by giving a difference (for example, JP-A-4-259511), a heated low-concentration solution is blown into the container from the nozzle, and the solution is applied from the nozzle to the inner wall of the container In which the solvent is flash evaporated and the solvent vapor is withdrawn from the container and the concentrated solution is withdrawn from the bottom of the container (eg, US Pat. No. 2,541,012, US Pat. No. 2,858,229, US Pat. No. 4,414,341, US Pat. No. 4,504,355, etc.).

  Prior to casting, it is preferable to filter off foreign matters such as undissolved matter, dust, and impurities using a suitable filter medium such as a wire mesh or flannel.

  For filtration of the cellulose ester solution, it is preferable to use a filter having an absolute filtration accuracy of 0.1 to 100 μm, and it is more preferable to use a filter having an absolute filtration accuracy of 0.5 to 25 μm.

  The thickness of the filter is preferably from 0.1 to 10 mm, more preferably from 0.2 to 2 mm. In that case, the filtration pressure is preferably 1.6 MPa or less, more preferably 1.2 MPa or less, further 1.0 MPa or less, and particularly preferably 0.2 MPa or less.

  As the filter medium, conventionally known materials such as glass fibers, cellulose fibers, filter paper, fluororesins such as tetrafluoroethylene resin can be preferably used, and ceramics, metals and the like are particularly preferably used. The viscosity of the cellulose ester solution immediately before film formation may be in a range that can be cast during film formation, and is usually preferably adjusted in the range of 10 Pa · s to 2000 Pa · s, preferably 30 Pa · s to 1000 Pa ·. s is more preferable, and 40 Pa · s to 500 Pa · s is more preferable.

The temperature at this time is not particularly limited as long as it is a temperature at the time of casting, but is preferably −5 to + 70 ° C., more preferably −5 to + 55 ° C.
(Film formation)
The cellulose ester film relating to the present invention can be obtained by forming a film using the cellulose ester solution.

  As a film forming method and equipment, a solution casting film forming apparatus conventionally used for producing a cellulose triacetate film is used.

  The dope (cellulose ester solution) prepared from the dissolving machine (kettle) is temporarily stored in a storage kettle, and the foam contained in the dope is defoamed for final preparation.

  The dope is sent from the dope discharge port to the pressure die through a pressure metering gear pump capable of delivering a constant amount of liquid with high accuracy, for example, by the number of rotations, and the dope is run endlessly from the die (slit) of the pressure die. The dry-dried dope film (also referred to as web) is peeled off from the metal support at a peeling point that is uniformly cast on the metal support and substantially rounds the metal support.

  Both ends of the obtained web are sandwiched between clips, transported by a tenter while keeping the width, dried, then transported by a roll group of a drying device, dried, and wound up to a predetermined length by a winder.

  The combination of the tenter and the roll group dryer varies depending on the purpose. In the solution casting film forming method used for the functional protective film for electronic displays, in addition to the solution casting film forming apparatus, surface processing on films such as an undercoat layer, an antistatic layer, an antihalation layer, a protective layer, etc. Therefore, a coating device is often added. Although each manufacturing process is described briefly below, it is not limited to these.

  First, the prepared cellulose ester solution (dope) is produced by casting a dope on a drum or band and evaporating the solvent when a cellulose ester film is produced by a solution casting film forming method.

  It is preferable to adjust the concentration of the dope before casting so that the solid content is 5 to 40% by mass. 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 30 ° C. or lower, and particularly preferably a metal support temperature of −10 to 20 ° C.

Further, JP 2000-301555, JP 2000-301558, JP 07-032391, JP 03-193316, JP 05-086212, JP 62-037113, JP 02-276607. The methods described in JP-A Nos. 55-014201, 02-111511, and 02-208650 can be used in the present invention.
(Multilayer casting)
The cellulose ester solution may be cast as a single layer liquid on a smooth band or drum as a metal support, or a plurality of cellulose ester liquids of two or more layers may be cast.

  When casting a plurality of cellulose ester solutions, even if a film is produced while casting and laminating a solution containing a cellulose ester from a plurality of casting openings provided at intervals in the traveling direction of the metal support, For example, the methods described in, for example, JP-A-61-158414, JP-A-1-122419, and JP-A-11-198285 can be applied. Further, it may be formed into a film by casting a cellulose ester solution from two casting ports. For example, JP-B-60-27562, JP-A-61-94724, JP-A-61-947245, JP-A-6-247245 It can be carried out by the methods described in JP-A-61-104813, JP-A-61-158413, and JP-A-6-134933.

  Also, a cellulose ester film casting method in which a flow of a high-viscosity cellulose ester solution described in JP-A-56-162617 is wrapped in a low-viscosity cellulose ester solution and the high- and low-viscosity cellulose ester solution is simultaneously extruded. Good. Furthermore, it is also a preferable embodiment that the outer solution described in JP-A-61-94724 and JP-A-61-94725 contains a larger amount of an alcohol component which is a poor solvent than the inner solution.

  Alternatively, by using two casting ports, peeling the film formed on the metal support by the first casting port, and performing the second casting on the side that was in contact with the metal support surface, A film may be prepared, for example, a method described in Japanese Patent Publication No. 44-20235.

  The cellulose ester solution to be cast may be the same solution or different cellulose ester solutions and is not particularly limited. In order to give a function to a plurality of cellulose ester layers, a cellulose ester solution corresponding to the function may be extruded from each casting port.

  Further, the cellulose ester solution can be cast simultaneously with other functional layers (for example, an adhesive layer, a dye layer, an antistatic layer, an antihalation layer, a UV absorbing layer, a polarizer, etc.).

  In conventional single-layer liquids, it is necessary to extrude a high-concentration and high-viscosity cellulose ester solution to obtain the required film thickness. In this case, the stability of the cellulose ester solution is poor and solids are generated. In many cases, however, it becomes a problem due to a failure or poor flatness.

  As a solution to this, by casting multiple cellulose ester solutions from the casting port, a highly viscous solution can be extruded onto a metal support at the same time. Not only can the drying load be reduced by using a concentrated cellulose ester solution, but the production speed of the film can be increased.

  In the case of co-casting, the inner and outer thicknesses are not particularly limited, but preferably the outer side is preferably 1 to 50% of the total film thickness, and more preferably 2 to 30%.

  Here, in the case of co-casting with three or more layers, the total thickness of the layer in contact with the metal support and the layer in contact with the air side is defined as the outer thickness. In the case of co-casting, a cellulose ester film having a laminated structure can be produced by co-casting cellulose ester solutions having different additive concentrations such as the above-mentioned plasticizer, ultraviolet absorber and matting agent.

  For example, a cellulose ester film having a structure of skin layer / core layer / skin layer can be produced. For example, the matting agent can be contained in the skin layer in a large amount or only in the skin layer.

  The plasticizer and the ultraviolet absorber can be contained in the core layer more than the skin layer, and may be contained only in the core layer.

  It is also possible to change the type of plasticizer and ultraviolet absorber between the core layer and the skin layer. It is also possible to add an excellent plasticizer or an ultraviolet absorber excellent in ultraviolet absorption.

  Moreover, it is also a preferable aspect to contain a peeling accelerator only in the skin layer on the metal support side. It is also preferable to add more alcohol, which is a poor solvent, to the skin layer than the core layer in order to cool the metal support by the cooling drum method to gel the solution. The Tg of the skin layer and the core layer may be different, and the Tg of the core layer is preferably lower than the Tg of the skin layer.

Further, the viscosity of the solution containing the cellulose ester at the time of casting may be different between the skin layer and the core layer, and the viscosity of the skin layer is preferably smaller than the viscosity of the core layer. It may be smaller than the viscosity.
(Casting)
As a solution casting method, a method in which the prepared dope is uniformly extruded from a pressure die onto a metal support, and a method using a doctor blade in which the dope once cast on the metal support is adjusted with a blade is used. Alternatively, there is a method using a reverse roll coater that adjusts with a reverse rotating roll, but a method using a pressure die is preferable.

  The pressure die includes a coat hanger type and a T die type, and any of them can be preferably used. In addition to the methods mentioned here, it can be carried out by various methods of casting a cellulose triacetate solution known in the art, and by setting each condition in consideration of differences in the boiling point of the solvent used, etc. The same effects as described in the respective publications can be obtained. The endlessly running metal support used to manufacture the cellulose ester film according to the present invention includes a drum whose surface is mirror-finished by chrome plating and a stainless steel belt whose surface is mirror-finished by surface polishing (even though it is called a band) Good) is used.

  One or two or more pressure dies used in the production of the cellulose ester film according to the present invention may be installed above the metal support.

  Preferably 1 or 2 groups. When two or more units are installed, the amount of dope to be cast may be divided into various ratios for each die, or the dope may be fed to the dies from each of a plurality of precision quantitative gear pumps.

The temperature of the cellulose ester solution used for casting is preferably −10 to 55 ° C., more preferably 25 to 50 ° C. In that case, all of the processes may be the same, or may be different at various points in the process. If they are different, the temperature may be a desired temperature just before casting.
(Dry)
The dope drying on the metal support involved in the production of the cellulose ester film is generally performed by applying hot air from the surface side of the metal support (drum or belt), that is, the surface of the web on the metal support, drum Alternatively, a method in which hot air is applied from the back of the belt, a liquid whose temperature is controlled is brought into contact with the back of the belt or drum opposite the dope casting surface, and the drum or belt is heated by heat transfer to control the surface temperature. Although there is a heat method, the back surface liquid heat transfer method is preferable.

  The surface temperature of the metal support before casting may be any number as long as it is not higher than the boiling point of the solvent used for the dope.

However, in order to promote drying and to lose fluidity on the metal support, the temperature should be set to 1 to 10 ° C. lower than the boiling point of the lowest boiling solvent used. Is preferred. This is not the case when the casting dope is cooled and peeled off without drying.
(Extension process)
The retardation of the cellulose ester film according to the present invention can be adjusted by stretching.

  Furthermore, there is also a method of positively stretching in the width direction. For example, JP-A-62-115035, JP-A-4-152125, JP-A-4-284111, JP-A-4-298310, and JP-A-11 -48271, and the like.

  This stretches the produced film in order to increase the in-plane retardation value of the cellulose ester film.

  The film is stretched at room temperature or under heating conditions. The heating temperature is preferably not higher than the glass transition temperature of the film. The stretching of the film may be uniaxial stretching only in the longitudinal or lateral direction, or may be simultaneous or sequential biaxial stretching. Stretching is performed at 1 to 200%.

  The stretching is preferably 1 to 100%, particularly preferably 1 to 50%. The birefringence of the optical film is preferably such that the refractive index in the width direction is larger than the refractive index in the length direction. Therefore, it is preferable to stretch more in the width direction.

  In addition, the stretching process may be performed in the middle of the film forming process, or the raw film that has been formed and wound may be stretched. In the former case, the stretching may be performed in a state including the residual solvent amount, and the stretching can be preferably performed at a residual solvent amount of 2 to 30%.

  Although the film thickness of the cellulose ester film relating to the present invention obtained after drying varies depending on the purpose of use, it is preferably 20 to 50 μm in order to obtain the effects of the present invention.

  The thickness of the film may be adjusted by adjusting the solid content concentration contained in the dope, the slit gap of the die base, the extrusion pressure from the die, the metal support speed, and the like.

  The width of the cellulose ester film obtained as described above is preferably 0.5 to 3 m, more preferably 0.6 to 2.5 m, and still more preferably 0.8 to 2.2 m. The length is preferably 100 to 10000 m per roll, more preferably 500 to 7000 m, and still more preferably 1000 to 6000 m.

  When winding, knurling is preferably applied to at least one end, the width is preferably 3 mm to 50 mm, more preferably 5 mm to 30 mm, and the height is preferably 0.5 to 500 μm, more preferably 1 to 200 μm. This may be a single push or a double push.

The variation in the Ro (590) value of the full width is preferably ± 5 nm, and more preferably ± 3 nm. Further, the variation of the Rt (590) value is preferably ± 10 nm, and more preferably ± 5 nm. Moreover, it is preferable that the variation in the Ro value and the Rt value in the length direction is also within the range of the variation in the width direction.
(Optical properties of cellulose ester film)
The cellulose ester film used for the second optically anisotropic layer is combined with the first optically anisotropic layer having a predetermined optical characteristic to provide a viewing angle of a liquid crystal display device, particularly an IPS mode liquid crystal display device. In order to contribute to widening, the following expressions (III) and (IV) are satisfied.
Formula (III): 20 nm ≦ Ro (590) ≦ 150 nm,
Formula (IV): 100 nm ≦ Rt (590) ≦ 300 nm
The Ro (590) of the second optically anisotropic layer is preferably 30 to 130 nm, and more preferably 40 to 110 nm. In addition, Rt (590) of the second optically anisotropic layer is preferably 120 to 280 nm, and more preferably 140 to 260 nm.

  In the present invention, Nz = Ro / Rt + 0.5 is preferably adjusted to 1.5 to 7.0. 2.0 to 5.5 is more preferably adjusted. Particularly preferred is 2.5 to 4.5. These adjustments can be made according to the type of additive, the amount added, and the draw ratio.

  In the present specification, Ro (λ) and Rt (λ) respectively represent in-plane retardation and retardation in the thickness direction at the measurement wavelength λ.

  Ro (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA-21ADH (manufactured by Oji Scientific Instruments).

  Rt (λ) is the wavelength of λnm from the direction inclined by + 40 ° with respect to the normal direction of the film using the Ro (λ) and the in-plane slow axis (determined by KOBRA-21ADH) as the tilt axis (rotary axis). Retardation value measured by making light incident, and measurement by making light of wavelength λ nm incident from a direction inclined by -40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis (rotation axis) KOBRA 21ADH is calculated based on the retardation values measured in a total of three directions.

  Here, as the assumed value of the average refractive index, values in the polymer handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can be used.

  The average refractive index of the cellulose ester at the wavelength is measured using an Abbe refractometer and a spectral light source, and nx, ny, and nz are calculated by KOBRA 21ADH by inputting the measured value of the average refractive index and the film thickness. . In this specification, the measurement wavelength is 590 nm unless otherwise specified.

  The variation of the slow axis angle in the film plane of the cellulose ester film relating to the present invention is preferably in the range of -2 to +2 degrees with respect to the reference direction of the roll film, and in the range of -1 to +1 degrees. More preferably, it is most preferably in the range of -0.5 degrees to +0.5 degrees. Here, the reference direction is the longitudinal direction of the roll film when the cellulose ester film is longitudinally stretched, and the width direction of the roll film when laterally stretched.

  Further, the cellulose ester film according to the present invention has a difference ΔRo (= Ro 10% RH−Ro 80% RH) between 0 to 10 nm at 25 ° C. and 10% RH and 25 ° C. and 80% RH, and 25 ° C. The difference ΔRt (= Rt 10% RH−Rt 80% RH) between the Rt value at 10% RH and the Rt value at 25 ° C. and 80% RH is 0 to 30 nm, which reduces the color change with time of the liquid crystal display device. Preferred above.

  In addition, the cellulose ester film according to the present invention preferably has an equilibrium water content of 3.2% or less at 25 ° C. and 80% RH in order to reduce the color change with time of the liquid crystal display device.

  The moisture content is measured by measuring a 7 mm × 35 mm cellulose ester film sample according to the present invention by the Karl Fischer method using a moisture meter and a sample drying apparatus (CA-03, VA-05, both Mitsubishi Chemical Corporation). It is calculated by dividing the amount of water (g) by the sample mass (g).

The cellulose ester film according to the present invention has a liquid crystal display having a moisture permeability of 60 ° C., 95% RH, 24 hr (film thickness 80 μm conversion) of 400 g / m ² · 24 hr to 1800 g / m ² · 24 hr. It is preferable in order to reduce the color change with time of the apparatus.

  If the film thickness of the cellulose ester film is thick, the moisture permeability becomes small, and if the film thickness is thin, the moisture permeability becomes large. Therefore, it is necessary to convert the sample of any film thickness to a standard of 80 μm. Conversion of the film thickness is obtained as (water vapor permeability in terms of 80 μm = measured moisture permeability × measured film thickness μm / 80 μm).

  The measurement method of moisture permeability is “Polymer Physical Properties II” (Polymer Experiment Course 4, Kyoritsu Shuppan), pages 285-294: Measurement of vapor permeation amount (mass method, thermometer method, vapor pressure method, adsorption amount method) The method described in can be applied.

  The glass transition temperature was measured by adjusting a cellulose ester film sample (unstretched) 5 mm × 30 mm according to the present invention at 25 ° C. and 60% RH for 2 hours or more, and then measuring a dynamic viscoelasticity measuring device (Vibron: DVA-225 (eye Tee Measurement Control Co., Ltd.)), measured at a distance between grips of 20 mm, a heating rate of 2 ° C./minute, a measurement temperature range of 30 ° C. to 200 ° C., and a frequency of 1 Hz. When a linear axis is taken at a temperature (° C.), a straight line 1 is drawn in the solid region to draw a straight line 1 in the solid region, and the storage elastic modulus transitions from the solid region to the glass transition region. When the straight line 2 is drawn, the intersection of the straight line 1 and the straight line 2 is a temperature at which the storage elastic modulus suddenly decreases and the film starts to soften when the temperature rises. Roll And a temperature of Tg (dynamic viscoelasticity).

  The cellulose ester film according to the present invention preferably has a haze of 0.01 to 2%. Here, the haze can be measured as follows.

  The haze is measured by measuring a cellulose ester film sample 40 mm × 80 mm according to the present invention at 25 ° C. and 60% RH with a haze meter (HGM-2DP, Suga Test Instruments) in accordance with JIS K-6714.

  Moreover, it is preferable that the mass change when the cellulose-ester film concerning this invention is left to stand for 48 hours on 80 degreeC and 90% RH conditions is 0 to 5%.

  In addition, the cellulose ester film according to the present invention has a dimensional change when left for 24 hours under conditions of 60 ° C. and 95% RH, and a size when left for 24 hours under conditions of 90 ° C. and 5% RH. It is preferable that all the changes are 0 to 5%.

It is preferable that the photoelastic coefficient is 50 × 10 ⁻¹³ cm ² / dyne or less in order to reduce the color change with time of the liquid crystal display device.

  As a specific measuring method, a tensile stress is applied to the major axis direction of a 10 mm × 100 mm cellulose ester film sample, and the retardation at that time is measured with an ellipsometer (M150, JASCO Corporation). The photoelastic coefficient is calculated from the amount of change in retardation.

  The retardation film of the present invention has a first optical anisotropic layer having an in-plane retardation Ro of 0 to 10 nm and a retardation Rt in the thickness direction of 400 to -80 nm. The in-plane retardation of the first optically anisotropic layer is preferably 0 to 5 nm, and more preferably 0 to 3 nm.

  Further, the retardation in the thickness direction of the optically anisotropic layer is preferably −360 to −100 nm, and more preferably −320 to −120 nm.

  The first optically anisotropic layer is preferably formed from a composition containing at least one liquid crystal compound. The liquid crystal compound is preferably a rod-like liquid crystal compound. When a rod-like liquid crystal compound is used, it is preferable that rod-like molecules are vertically aligned in the first optically anisotropic layer.

  The type of liquid crystal compound is not particularly limited. The first optically anisotropic layer contained in the retardation film of the present invention may be prepared, for example, by forming a low molecular liquid crystal compound in a nematic orientation in a liquid crystal state and then immobilizing it by photocrosslinking or thermal crosslinking. .

  Alternatively, the polymer liquid crystalline compound may be formed in a nematic alignment in a liquid crystal state and then cooled to cool the alignment. In the present invention, a liquid crystalline compound is used for the production of the optically anisotropic layer, but the liquid crystalline compound is often contained in the optically anisotropic layer in a state of being fixed by polymerization or the like in the production process. Finally, it is not necessary to show liquid crystallinity. The polymerizable liquid crystal compound may be a polyfunctional polymerizable liquid crystal or a monofunctional polymerizable liquid crystal compound.

  In the first optical anisotropic layer included in the retardation film of the present invention, the molecules of the liquid crystal compound are preferably fixed in a predetermined alignment state, preferably in a vertical alignment state. The term “substantially perpendicular to the rod-like liquid crystalline compound” means that the angle formed between the film surface and the director of the rod-like liquid crystalline compound is in the range of 70 ° to 90 °. 80 ° to 90 ° are more preferable, and 85 ° to 90 ° are more preferable.

  The first optically anisotropic layer contained in the retardation film of the present invention may be formed on a support. The second optically anisotropic layer made of the aforementioned predetermined cellulose ester film may be used as the support, or after the first optically anisotropic layer is provided on the temporary support, the polarizer or the first 2 may be transferred to the optically anisotropic layer 2, or an optically isotropic film may be used as the support. A polarizer and the retardation film of the present invention can be laminated and incorporated into a liquid crystal display device or the like as a polarizing plate.

  Next, materials used for manufacturing the first optical anisotropic layer, a manufacturing method, and the like will be described in detail.

The first optically anisotropic layer can be formed from a composition containing a liquid crystal compound such as a rod-like liquid crystal compound and, if desired, the following polymerization initiator, alignment control agent, and other additives.
(Bar-shaped liquid crystalline compound)
In the present invention, it is preferable to form the first optically anisotropic layer using a rod-like liquid crystalline compound. Examples of rod-like liquid crystalline compounds include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines. , Phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are preferably used.

  Not only the above low-molecular liquid crystalline compounds but also high-molecular liquid crystalline compounds can be used. It is more preferable to fix the alignment of the rod-like liquid crystal compound by polymerization. As the liquid crystalline compound, those having a partial structure capable of causing polymerization or crosslinking reaction by actinic rays, electron beams, heat, or the like are suitably used.

The number of the partial structures is preferably 1 to 6, more preferably 1 to 3. As the polymerizable rod-like liquid crystalline compound, Makromol. Chem. 190, 2255 (1989), Advanced Materials 5, 107 (1993), US Pat. Nos. 4,683,327, 5,622,648, and 5,770,107, International Publication WO95 / 22586. No. 95/24455, No. 97/00600, No. 98/23580, No. 98/52905, JP-A-1-272551, No. 6-16616, and No. 7-110469. 11-80081, JP 2001-328773, JP 2004-240188, JP 2005-99236, JP 2005-99237, JP 2005-121827, JP It is possible to use the compounds described in 2002-30042 That.
(Vertical alignment accelerator)
In order to uniformly align the liquid crystal compound vertically, it is necessary to control the alignment of the liquid crystal compound vertically on the alignment film interface side and the air interface side. For this purpose, a composition obtained by adding a compound having an effect of vertically aligning the liquid crystalline compound by an excluded volume effect, an electrostatic effect, or a surface energy effect to the alignment film may be employed.

  In addition, with regard to alignment control on the air interface side, a compound that is unevenly distributed at the air interface during alignment of the liquid crystalline compound and acts to align the liquid crystalline compound vertically by its excluded volume effect, electrostatic effect, or surface energy effect is blended The liquid crystal composition may be used.

As such a compound (alignment film interface side vertical alignment agent) that promotes the vertical alignment of the molecules of the liquid crystal compound on the alignment film interface side, a pyridinium derivative is preferably used. As a compound (air interface side vertical alignment agent) that promotes the vertical alignment of the molecules of the liquid crystal compound on the air interface side, a fluoro aliphatic group that promotes the uneven distribution of the compound on the air interface side, One or more hydrophilic groups selected from the group consisting of a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phosphonoxy group {—OP (═O) (OH) ₂ }, and salts thereof A compound is preferably used.

Further, by blending these compounds, for example, when a liquid crystalline composition is prepared as a coating solution, the coating property of the coating solution is improved, and the occurrence of unevenness and repellency is suppressed. The vertical alignment agent will be described in detail below.
(Alignment film interface side vertical alignment agent)
As the alignment film interface-side vertical alignment agent that can be used in the present invention, a pyridinium derivative (pyridinium salt) represented by the following formula (I) is preferably used. By adding at least one of the pyridinium derivatives to the liquid crystalline composition, the molecules of the discotic liquid crystalline compound can be aligned substantially vertically in the vicinity of the alignment film.

In the formula (I), L ⁰ represents a divalent linking group, an alkylene group and —O—, —S—, —CO—, —SO ₂ —, —NR ^a — (where R ^a is the number of carbon atoms. Is an alkyl group or a hydrogen atom having 1 to 5), an alkenylene group, an alkynylene group or an arylene group, and preferably a divalent linking group having 1 to 20 carbon atoms. The alkylene group may be linear or branched.

In the formula (I), R ⁰ is a hydrogen atom, an unsubstituted amino group, or a substituted amino group substituted with a substituent having 1 to 20 carbon atoms. When R ⁰ is a substituted amino group, it is preferably substituted with an aliphatic group.

Examples of the aliphatic group include an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, and a substituted alkynyl group. When R ⁰ is a disubstituted amino group, two aliphatic groups may be bonded to each other to form a nitrogen-containing heterocyclic ring. The nitrogen-containing heterocycle formed at this time is preferably a 5-membered ring or a 6-membered ring.

R ⁰ is preferably a hydrogen atom, an unsubstituted amino group or a substituted amino group having 1 to 20 carbon atoms, and is a hydrogen atom, an unsubstituted amino group or a substituted amino group having 2 to 12 carbon atoms. More preferably, it is more preferably a hydrogen atom, an unsubstituted amino group, or a substituted amino group having 2 to 8 carbon atoms. When R ⁰ is an amino group, it is preferably substituted at the 4-position of the pyridinium ring.

In the formula (I), X ⁰ is an anion. Examples of anions include halogen anions (for example, fluorine ions, chlorine ions, bromine ions, iodine ions, etc.), sulfonate ions (for example, methanesulfonate ions, trifluoromethanesulfonate ions, methylsulfate ions, p-toluene). Sulfonate ion, p-chlorobenzenesulfonate ion, 1,3-benzenedisulfonate ion, 1,5-naphthalenedisulfonate ion, 2,6-naphthalenedisulfonate ion, sulfate ion, carbonate ion, nitrate ion, thiocyanate Examples include acid ions, perchlorate ions, tetrafluoroborate ions, picrate ions, acetate ions, formate ions, trifluoroacetate ions, phosphate ions (for example, hexafluorophosphate ions), and hydroxide ions. X ⁰ is preferably a halogen anion, a sulfonate ion, or a hydroxide ion.

In the formula (I), Y ¹ is a divalent linking group having 1 to 30 carbon atoms having a 5-membered or 6-membered ring as a partial structure.

The cyclic partial structure contained in Y ¹ is more preferably a cyclohexyl ring, an aromatic ring or a heterocyclic ring. Examples of the aromatic ring include a benzene ring, an indene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring, an anthracene ring, a biphenyl ring, and a pyrene ring. More preferred are a benzene ring, a biphenyl ring, and a naphthalene ring.

  The hetero atom constituting the hetero ring is preferably a nitrogen atom, an oxygen atom or a sulfur atom, for example, a furan ring, a thiophene ring, a pyrrole ring, a pyrroline ring, a pyrrolidine ring, an oxazole ring, an isoxazole ring, a thiazole ring or an isothiazole. Ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, pyrazoline ring, pyrazolidine ring, triazole ring, furazane ring, tetrazole ring, pyran ring, dioxane ring, dithiane ring, thiine ring, pyridine ring, piperidine ring, oxazine ring Morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring and triazine ring.

The heterocycle is preferably a 6-membered ring. The divalent linking group having a 5-membered ring or 6-membered ring represented by Y ¹ as a partial structure may have a substituent.

  In the formula (I), Z represents a halogen-substituted phenyl group, a nitro-substituted phenyl group, a cyano-substituted phenyl group, a phenyl group substituted with an alkyl group having 1 to 10 carbon atoms, or an alkoxy having 2 to 10 carbon atoms. A phenyl group substituted with a group, an alkyl group having 1 to 12 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxy having 2 to 13 carbon atoms A carbonyl group, an aryloxycarbonyl group having 7 to 26 carbon atoms, an arylcarbonyloxy group having 7 to 26 carbon atoms, a cyano-substituted phenyl group, a halogen-substituted phenyl group, and an alkyl having 1 to 10 carbon atoms. Phenyl group substituted with a group, phenyl group substituted with an alkoxy group having 2 to 10 carbon atoms, aryloxycarboe having 7 to 26 carbon atoms Group or carbon atoms is preferably an aryl carbonyl group having 7 to 26.

  Z may further have a substituent. Examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom), a cyano group, a nitro group, and a carbon atom number of 1 to 16. An alkyl group having 1 to 16 carbon atoms, an alkynyl group having 1 to 16 carbon atoms, a halogen-substituted alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, An acyl group having 2 to 16 carbon atoms, an alkylthio group having 1 to 16 carbon atoms, an acyloxy group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, a carbamoyl group, a carbon atom An alkyl-substituted carbamoyl group having 2 to 16 carbon atoms and an acylamino group having 2 to 16 carbon atoms are included.

  The pyridinium compound used in the present invention is preferably a pyridinium compound represented by the following formula (Ia).

In the formula (Ia), L ⁰³ represents a single bond, —O—, —O—CO—, —CO—O—, —C≡C—, —CH═CH—, —CH═N—, —N═. CH—, —N═N—, —O—AL—O—, —O—AL—O—CO—, —O—AL—CO—O—, —CO—O—AL—O—, —CO—. O-AL-O-CO-, -CO-O-AL-CO-O-, -O-CO-AL-O-, -O-CO-AL-O-CO- or O-CO-AL-CO -O-. AL is an alkylene group having 1 to 10 carbon atoms. L ⁰³ represents a single bond, —O—, —O—AL—O—, —O—AL—O—CO—, —O—AL—CO—O—, —CO—O—AL—O—, — CO-O-AL-O-CO-, -CO-O-AL-CO-O-, -O-CO-AL-O-, -O-CO-AL-O-CO- or O-CO-AL -CO-O- is preferable, and a single bond or O- is more preferable.

In the formula (Ia), L ⁰⁴ represents a single bond, —O—, —O—CO—, —CO—O—, —C≡C—, —CH═CH—, —CH═N—, —N═. CH- or N = N-.

In the formula (Ia), R ⁰³ is a hydrogen atom, an unsubstituted amino group, or an alkyl-substituted amino group having 2 to 20 carbon atoms. When R ⁰³ is a dialkyl-substituted amino group, two alkyl groups may be bonded to each other to form a nitrogen-containing heterocycle.

The nitrogen-containing heterocycle formed at this time is preferably a 5-membered ring or a 6-membered ring. R ⁰³ is more preferably a hydrogen atom, an unsubstituted amino group, or a dialkyl-substituted amino group having 2 to 12 carbon atoms, and most preferably a hydrogen atom, an unsubstituted amino group, or a dialkyl-substituted amino group having 2 to 8 carbon atoms. . When R ⁰³ is an unsubstituted amino group, the 4-position of the pyridinium ring is preferably amino-substituted.

In the formula (Ia), Y ² and Y ³ are each independently a divalent group consisting of a 6-membered ring which may have a substituent. Examples of the 6-membered ring include an aliphatic ring, an aromatic ring (benzene ring), and a heterocyclic ring. Examples of the 6-membered aliphatic ring include a cyclohexane ring, a cyclohexene ring, and a cyclohexadiene ring. Examples of 6-membered heterocycles include pyran ring, dioxane ring, dithiane ring, thiin ring, pyridine ring, piperidine ring, oxazine ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring and triazine ring. Can be mentioned. Another 6-membered ring or 5-membered ring may be condensed to the 6-membered ring.

  Examples of the substituent include a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, and an alkoxy group having 1 to 12 carbon atoms. The alkyl group and the alkoxy group may be substituted with an acyl group having 2 to 12 carbon atoms or an acyloxy group having 2 to 12 carbon atoms. The definition of an acyl group and an acyloxy group will be described later.

In the formula (Ia), X ⁰¹ is an anion. X ⁰¹ is preferably a monovalent anion. Examples of anions include halogen anions (eg, fluorine ions, chlorine ions, bromine ions, iodine ions) and sulfonate ions (eg, methanesulfonate ions, p-toluenesulfonate ions, benzenesulfonate ions). It is.

In Formula (Ia), Z ¹ is a hydrogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, and the alkyl group and the alkoxy group are each a carbon atom. It may be substituted with an acyl group having 2 to 12 atoms or an acyloxy group having 2 to 12 carbon atoms.

In the formula (Ia), m is 1 or 2, and when m is 2, two L ⁰⁴ and two Y ³ may be different.

When m is 2, Z ¹ is preferably a cyano group, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

When m is 1, Z ¹ is an alkyl group having 7 to 12 carbon atoms, an alkoxy group having 7 to 12 carbon atoms, an acyl-substituted alkyl group having 7 to 12 carbon atoms, or 7 carbon atoms. It is preferably an acyl-substituted alkoxy group having -12, an acyloxy-substituted alkyl group having 7-12 carbon atoms, or an acyloxy-substituted alkoxy group having 7-12 carbon atoms.

  The acyl group is represented by —CO—R, the acyloxy group is represented by —O—CO—R, and R is an aliphatic group (alkyl group, substituted alkyl group, alkenyl group, substituted alkenyl group, alkynyl group, substituted alkynyl group) or aromatic. Group (aryl group, substituted aryl group). R is preferably an aliphatic group, and more preferably an alkyl group or an alkenyl group.

In formula (Ia), p is an integer of 1-10. C _p H _2p means a chain alkylene group which may have a branched structure. C _p H _2p is preferably a linear alkylene group. Further, p is more preferably 1 or 2.

  Specific examples of the compound represented by formula (I) and / or (Ia) are shown below. Here, Me represents a methyl group.

  A pyridinium derivative is generally obtained by alkylating a pyridine ring (Menstokin reaction).

The preferable range of the content of the pyridinium derivative in the liquid crystal composition varies depending on the use, but 0.005 in the liquid crystal composition (liquid crystal composition excluding the solvent when prepared as a coating liquid). It is preferably -8% by mass, more preferably 0.01-5% by mass.
(Air interface side vertical alignment agent)
As an air interface side vertical alignment agent usable in the present invention, a fluoro aliphatic group, a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phosphonoxy group {—OP (═O) (OH) ₂ } And one or more hydrophilic groups selected from the group consisting of the salts thereof, a fluoroaliphatic group-containing polymer (hereinafter referred to as “fluorine polymer”), or a compound represented by the general formula (III) Fluorine compounds are preferably used.

  First, the fluorine polymer will be described.

The fluoropolymer usable in the present invention includes a fluoroaliphatic group, a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phosphonoxy group {—OP (═O) (OH) ₂ }, and their It contains one or more hydrophilic groups selected from the group consisting of salts.

  The types of polymers are described in “Revised Chemistry of Polymer Synthesis” (Takayuki Otsu, published by Kagaku Dojin Co., 1968), pages 1-4, for example, polyolefins, polyesters, polyamides, polyimides. , Polyurethanes, polycarbonates, polysulfones, polycarbonates, polyethers, polyacetals, polyketones, polyphenylene oxides, polyphenylene sulfides, polyarylates, polytetrafluoroethylene (PTFE), polyvinylidene fluorides And cellulose derivatives. The fluoropolymer is preferably a polyolefin.

  The fluorine-based polymer is a polymer having a fluoroaliphatic group in the side chain. The fluoroaliphatic group preferably has 1 to 12 carbon atoms, and more preferably 6 to 10 carbon atoms.

  The aliphatic group may be linear or cyclic, and when it is linear, it may be linear or branched.

  Of these, a linear fluoroaliphatic group having 6 to 10 carbon atoms is preferable. The degree of substitution with fluorine atoms is not particularly limited, but 50% or more of hydrogen atoms in the aliphatic group are preferably substituted with fluorine atoms, and more preferably 60% or more are substituted. The fluoroaliphatic group is contained in a side chain bonded to the polymer main chain via an ester bond, an amide bond, an imide bond, a urethane bond, a urea bond, an ether bond, a thioether bond, an aromatic ring, or the like.

  One of the fluoroaliphatic groups is derived from a fluoroaliphatic compound produced by a telomerization method (also referred to as a telomer method) or an oligomerization method (also referred to as an oligomer method).

  Regarding the production method of these fluoroaliphatic compounds, for example, “Synthesis and Function of Fluorine Compounds” (Supervision: Nobuo Ishikawa, Issue: CMC Co., 1987), “Chemistry of Organic Fluorines Compounds”. II "(Monograph 187, Ed by Milos Hudricky and Attila E. Pavlath, American Chemical Society 1995).

  The telomerization method is a method of synthesizing a telomer by radical polymerization of a fluorine-containing vinyl compound such as tetrafluoroethylene using an alkyl halide having a large chain transfer constant such as iodide as a telogen (example in Scheme-1). showed that).

  The obtained terminal iodinated telomer is usually subjected to appropriate terminal chemical modification such as [Scheme 2], and led to a fluoroaliphatic compound. These compounds are further converted into a desired monomer structure as needed, and used for the production of a fluoropolymer.

  Specific examples of monomers that can be used in the production of the fluorine-based polymer that can be used in the present invention are listed below, but the present invention is not limited to the following specific examples.

  One aspect of a fluorine-based polymer that can be used in the present invention is represented by a repeating unit derived from a fluoroaliphatic group-containing monomer (hereinafter sometimes referred to as “fluorine-based monomer”) and the following formula (II): It is a copolymer having a repeating unit containing a hydrophilic group.

In the above formula (II), R ⁶¹ , R ⁶² and R ⁶³ each independently represents a hydrogen atom or a substituent. Q represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, or a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof. L represents an arbitrary group selected from the following linking group group, or a divalent linking group formed by combining two or more thereof.
(Linked group group)
Single bond, —O—, —CO—, —NR ^b — (R ^b represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group), —S—, —SO ₂ —, —P (═O) (OR ^f ) — (R ^f represents an alkyl group, an aryl group, or an aralkyl group), an alkylene group, and an arylene group.

In formula (II), R ⁶¹ , R ⁶² and R ⁶³ each independently represents a hydrogen atom or a substituent selected from the substituent group exemplified below.
(Substituent group)
An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, still more preferably 1 to 8 carbon atoms, such as a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group and the like, alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, More preferably, it is a C2-C8 alkenyl group, for example, a vinyl group, an aryl group, 2-butenyl group, 3-pentenyl group etc., an alkynyl group (preferably C2-C20, more preferably). Is an alkynyl group having 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms, such as a propargyl group or a 3-pentynyl group. An aryl group (preferably an aryl group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, still more preferably 6 to 12 carbon atoms, such as a phenyl group, a p-methylphenyl group, A naphthyl group), an aralkyl group (preferably an aralkyl group having 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, still more preferably 7 to 12 carbon atoms, such as a benzyl group, a phenethyl group, A 3-phenylpropyl group), a substituted or unsubstituted amino group (preferably an amino group having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, still more preferably 0 to 6 carbon atoms, For example, an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, an anilino group, etc.), an alkoxy group (preferably An alkoxy group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 10 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, and a butoxy group, and an alkoxycarbonyl group (preferably Is an alkoxycarbonyl group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably 2 to 10 carbon atoms, such as a methoxycarbonyl group and an ethoxycarbonyl group, and an acyloxy group (preferably carbon An acyloxy group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably 2 to 10 carbon atoms, such as an acetoxy group and a benzoyloxy group, and an acylamino group (preferably having 2 to 20 carbon atoms). More preferably an acylamino group having 2 to 16 carbon atoms, more preferably 2 to 10 carbon atoms. For example, an acetylamino group, a benzoylamino group, etc.), an alkoxycarbonylamino group (preferably having a carbon number of 2-20, more preferably having a carbon number of 2-16, and further preferably having a carbon number of 2-12). A methoxycarbonylamino group), an aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 16 carbon atoms, and further preferably having 7 to 12 carbon atoms) A carbonylamino group, such as a phenyloxycarbonylamino group), a sulfonylamino group (preferably a sulfonyl group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms). An amino group, for example, a methanesulfonylamino group, And sulfamoyl groups (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, still more preferably 0 to 12 carbon atoms, such as sulfamoyl group, methyl A sulfamoyl group, a dimethylsulfamoyl group, a phenylsulfamoyl group and the like), a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms). For example, an unsubstituted carbamoyl group, a methylcarbamoyl group, a diethylcarbamoyl group, a phenylcarbamoyl group, and the like, an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms). More preferably an alkylthio group having 1 to 12 carbon atoms. Examples thereof include a methylthio group and an ethylthio group), an arylthio group (preferably an arylthio group having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, and still more preferably 6 to 12 carbon atoms. Group), a sulfonyl group (preferably a sulfonyl group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms, and examples thereof include a mesyl group and a tosyl group. A sulfinyl group (preferably a sulfinyl group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and still more preferably 1 to 12 carbon atoms, such as a methanesulfinyl group and a benzenesulfinyl group). Ureido groups (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and even more preferred) Or a ureido group having 1 to 12 carbon atoms, such as an unsubstituted ureido group, a methylureido group, or a phenylureido group, and a phosphoric acid amide group (preferably having 1 to 20 carbon atoms, more preferably A phosphoric acid amide group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, such as a diethylphosphoric acid amide group and a phenylphosphoric acid amide group), a hydroxy group, a mercapto group, a halogen atom ( For example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having 1 to 30 carbon atoms) More preferably, it is a 1-12 heterocyclic group, for example, a heterocyclic ring having a heteroatom such as a nitrogen atom, an oxygen atom, a sulfur atom, etc. For example, imidazolyl group, pyridyl group, quinolyl group, furyl group, piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group, etc.), silyl group (preferably having 3 carbon atoms) -40, more preferably a silyl group having 3 to 30 carbon atoms, still more preferably 3 to 24 carbon atoms, and examples thereof include a trimethylsilyl group and a triphenylsilyl group. These substituents may be further substituted with these substituents. Moreover, when it has two or more substituents, they may be the same or different. If possible, they may be bonded to each other to form a ring.

R ⁶¹ , R ⁶² and R ⁶³ are each independently a hydrogen atom, an alkyl group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.) or a group represented by -LQ described later. It is preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a chlorine atom, or a group represented by -LQ, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Particularly preferred are a hydrogen atom and an alkyl group having 1 to 2 carbon atoms. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, sec-butyl group and the like. The alkyl group may have a suitable substituent. Examples of the substituent include a halogen atom, aryl group, heterocyclic group, alkoxyl group, aryloxy group, alkylthio group, arylthio group, acyl group, hydroxyl group, acyloxy group, amino group, alkoxycarbonyl group, acylamino group, oxycarbonyl Group, carbamoyl group, sulfonyl group, sulfamoyl group, sulfonamido group, sulfolyl group, carboxyl group and the like. The carbon number of the alkyl group does not include the carbon atom of the substituent. The same applies to the carbon number of other groups.

L represents a divalent linking group selected from the above linking group group, or a divalent linking group formed by combining two or more thereof. In the linking group group, R ^{b in} —NR ^b — represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and preferably a hydrogen atom or an alkyl group. In addition, R ^f of —PO (OR ^f ) — represents an alkyl group, an aryl group, or an aralkyl group, and preferably an alkyl group. The carbon number when R ^b and R ^f represent an alkyl group, an aryl group or an aralkyl group is the same as that described in the “substituent group”. L preferably contains a single bond, —O—, —CO—, —NR ^b —, —S—, —SO ₂ —, an alkylene group or an arylene group, and —CO—, —O—, —NR It is particularly preferable that ^b- , an alkylene group or an arylene group is contained. When L includes an alkylene group, the alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 6 carbon atoms. Specific examples of particularly preferable alkylene groups include a methylene group, an ethylene group, a trimethylene group, a tetrabutylene group, and a hexamethylene group. When L contains an arylene group, the carbon number of the arylene group is preferably 6 to 24, more preferably 6 to 18, and still more preferably 6 to 12. Specific examples of particularly preferred arylene groups include phenylene groups and naphthalene groups. When L contains a divalent linking group (that is, an aralkylene group) obtained by combining an alkylene group and an arylene group, the carbon number of the aralkylene group is preferably 7 to 34, more preferably 7 to 26, and still more preferably. 7-16. Specific examples of particularly preferred aralkylene groups include a phenylenemethylene group, a phenyleneethylene group, and a methylenephenylene group. The group listed as L may have a suitable substituent. As such a substituent, the same substituents as those described above as the substituents for R ⁶¹ , R ⁶² and R ⁶³ can be exemplified.

  The specific structure of L is illustrated below.

  In the formula (II), Q is a carboxyl group, a salt of a carboxyl group (for example, lithium salt, sodium salt, potassium salt, ammonium salt (for example, ammonium, tetramethylammonium, trimethyl-2-hydroxyethylammonium, tetrabutylammonium, Trimethylbenzylammonium, dimethylphenylammonium, etc.), pyridinium salts, etc.), sulfo groups, salts of sulfo groups (examples of cations forming the salts are the same as those described above for carboxyl groups), phosphonoxy groups, salts of phosphonoxy groups ( Examples of the cation forming the salt are the same as those described for the carboxyl group).

  A carboxyl group, a sulfo group, and a phospho group are more preferable, and a carboxyl group or a sulfo group is particularly preferable.

  The fluoropolymer may contain one type of repeating unit represented by the formula (II) or two or more types.

  Moreover, the said fluorine-type polymer may have 1 type (s) or 2 or more types of repeating units other than said each repeating unit. The other repeating units are not particularly limited, and preferred examples thereof include repeating units derived from ordinary radical polymerizable monomers.

Hereinafter, specific examples of monomers for deriving other repeating units will be given. The fluoropolymer may contain a repeating unit derived from one or more monomers selected from the following monomer group.
Monomer group (1) Alkenes ethylene, propylene, 1-butene, isobutene, 1-hexene, 1-dodecene, 1-octadecene, 1-eicocene, hexafluoropropene, vinylidene fluoride, chlorotrifluoroethylene, 3, 3, 3-trifluoropropylene, tetrafluoroethylene, vinyl chloride, vinylidene chloride, etc .;
(2) Dienes 1,3-butadiene, isoprene, 1,3-pentadiene, 2-ethyl-1,3-butadiene, 2-n-propyl-1,3-butadiene, 2,3-dimethyl-1,3 -Butadiene, 2-methyl-1,3-pentadiene, 1-phenyl-1,3-butadiene, 1-α-naphthyl-1,3-butadiene, 1-β-naphthyl-1,3-butadiene, 2-chloro -1,3-butadiene, 1-bromo-1,3-butadiene, 1-chlorobutadiene, 2-fluoro-1,3-butadiene, 2,3-dichloro-1,3-butadiene, 1,1,2- Trichloro-1,3-butadiene and 2-cyano-1,3-butadiene, 1,4-divinylcyclohexane and the like;
(3) Derivatives of α, β-unsaturated carboxylic acid (3a) Alkyl acrylates methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate , Amyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, tert-octyl acrylate, dodecyl acrylate, phenyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, 2-bromoethyl acrylate, 4-chlorobutyl acrylate, 2-cyanoethyl acrylate, 2-acetoxyethyl acrylate, methoxybenzyl ester Chryrate, 2-chlorocyclohexyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, 2-methoxyethyl acrylate, ω-methoxypolyethylene glycol acrylate (number of added polyoxyethylene: n = 2 to 100), 3-methoxy Butyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, 2- (2-butoxyethoxy) ethyl acrylate, 1-bromo-2-methoxyethyl acrylate, 1,1-dichloro-2-ethoxyethyl acrylate, glycidyl acrylate Such);
(3b) alkyl methacrylates methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, amyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2 -Ethylhexyl methacrylate, n-octyl methacrylate, stearyl methacrylate, benzyl methacrylate, phenyl methacrylate, allyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, cresyl methacrylate, naphthyl methacrylate, 2-methoxyethyl methacrylate, 3-methoxybutyl methacrylate, ω Methoxypolyethylene glycol methacrylate (number of added polyoxyethylene: n = 2 to 100), 2-acetoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-butoxyethyl methacrylate, 2- (2-butoxyethoxy) ethyl methacrylate Glycidyl methacrylate, 3-trimethoxysilylpropyl methacrylate, allyl methacrylate, 2-isocyanatoethyl methacrylate, etc .;
(3c) Unsaturated polycarboxylic acid diesters dimethyl maleate, dibutyl maleate, dimethyl itaconate, dibutyl taconate, dibutyl crotonate, dihexyl crotonate, diethyl fumarate, dimethyl fumarate, etc .;
(3d) Amides of α, β-unsaturated carboxylic acids N, N-dimethylacrylamide, N, N-diethylacrylamide, Nn-propylacrylamide, N-tertbutylacrylamide, N-tertoctylmethacrylamide, N- Cyclohexylacrylamide, N-phenylacrylamide, N- (2-acetoacetoxyethyl) acrylamide, N-benzylacrylamide, N-acryloylmorpholine, diacetone acrylamide, N-methylmaleimide and the like;
(4) Unsaturated nitriles acrylonitrile, methacrylonitrile, etc .;
(5) Styrene and its derivatives Styrene, vinyl toluene, ethyl styrene, p-tert butyl styrene, methyl p-vinyl benzoate, α-methyl styrene, p-chloromethyl styrene, vinyl naphthalene, p-methoxy styrene, p-hydroxy Methyl styrene, p-acetoxy styrene, etc .;
(6) Vinyl esters Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl benzoate, vinyl salicylate, vinyl chloroacetate, vinyl methoxyacetate, vinyl vinyl acetate, etc .;
(7) Vinyl ethers methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether, n-dodecyl Vinyl ether, n-eicosyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, fluorobutyl vinyl ether, fluorobutoxyethyl vinyl ether and the like; and (8) other polymerizable monomers N-vinylpyrrolidone, methyl vinyl ketone, phenyl vinyl ketone, Methoxyethyl vinyl ketone, 2-vinyl oxazoline, 2-isopropenyl oxazoline, etc.

  In the fluoropolymer, the amount of the fluoroaliphatic group-containing monomer is preferably 5% by mass or more, more preferably 10% by mass or more, and more preferably 30% by mass or more of the total amount of constituent monomers of the polymer. Is more preferable.

  In the fluoropolymer, the amount of the repeating unit represented by the formula (II) is preferably 0.5% by mass or more of the total amount of constituent monomers of the fluoropolymer, and is 1 to 20% by mass. More preferably, it is 1 to 10% by mass.

  Since the above-mentioned mass percentage is likely to vary in a preferable range depending on the molecular weight of the monomer used, the content of the repeating unit represented by the formula (II) is expressed by the number of functional group moles per unit mass of the polymer. Can be defined accurately.

  When this notation is used, the preferable amount of the hydrophilic group (Q in the formula (II)) contained in the fluoropolymer is 0.1 mmol / g to 10 mmol / g, and the more preferable amount is 0. .2 mmol / g to 8 mmol / g.

  The fluoropolymer used in the present invention has a mass average molecular weight of preferably 1,000,000 or less, more preferably 500,000 or less, and even more preferably 100,000 or less. The mass average molecular weight can be measured as a value in terms of polystyrene (PS) using gel permeation chromatography (GPC).

  The polymerization method of the fluorine-based polymer is not particularly limited. For example, a polymerization method such as cation polymerization, radical polymerization, or anion polymerization using a vinyl group can be employed. Polymerization is particularly preferred in that it can be used for general purposes.

  As the polymerization initiator for radical polymerization, known compounds such as radical thermal polymerization initiators and radical photopolymerization initiators can be used, and it is particularly preferable to use radical thermal polymerization initiators.

  Here, the radical thermal polymerization initiator is a compound that generates radicals by heating to a decomposition temperature or higher. Examples of such radical thermal polymerization initiators include diacyl peroxide (acetyl peroxide, benzoyl peroxide, etc.), ketone peroxide (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), hydroperoxide (hydrogen peroxide, tert. -Butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyesters (tert-butyl peroxyacetate, tert -Butyl peroxypivalate, etc.), azo compounds (azobisisobutyronitrile, azobisisovaleronitrile, etc.), persulfates (ammonium persulfate, sodium persulfate) Beam, such as potassium sulphate).

  Such radical thermal polymerization initiators can be used alone or in combination of two or more.

  The radical polymerization method is not particularly limited, and an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, a solution polymerization method, and the like can be adopted.

  The solution polymerization, which is a typical radical polymerization method, will be described more specifically. The outlines of other polymerization methods are the same, and details thereof are described, for example, in “Polymer Science Experimental Method” edited by Polymer Society (Tokyo Kagaku Dojin, 1981).

  An organic solvent is used for solution polymerization. These organic solvents can be arbitrarily selected as long as the objects and effects of the present invention are not impaired.

  These organic solvents are usually organic compounds having boiling points under atmospheric pressure in the range of 50 to 200 ° C., and organic compounds that uniformly dissolve each component are preferred. Examples of preferred organic solvents are: alcohols such as isopropanol and butanol; ethers such as dibutyl ether, ethylene glycol dimethyl ether, tetrahydrofuran and dioxane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethyl acetate and acetic acid And esters such as butyl, amyl acetate, and γ-butyrolactone; and aromatic hydrocarbons such as benzene, toluene, and xylene.

  In addition, these organic solvents can be used individually by 1 type or in combination of 2 or more types. Furthermore, a water-mixed organic solvent in which water is used in combination with the above organic solvent is also applicable from the viewpoint of the solubility of the monomer and the polymer to be produced.

  Also, the solution polymerization conditions are not particularly limited, but for example, it is preferable to heat within a temperature range of 50 to 200 ° C. for 10 minutes to 30 hours.

  Furthermore, in order not to deactivate the generated radicals, it is preferable to perform an inert gas purge not only during solution polymerization but also before the start of solution polymerization. Usually, nitrogen gas is suitably used as the inert gas.

  In order to obtain the fluoropolymer in a preferable molecular weight range, a radical polymerization method using a chain transfer agent is particularly effective.

  As chain transfer agents, mercaptans (for example, octyl mercaptan, decyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, octadecyl mercaptan, thiophenol, p-nonylthiophenol, etc.), polyhalogenated alkyls (for example, carbon tetrachloride, Chloroform, 1,1,1-trichloroethane, 1,1,1-tribromooctane, etc.) and low-activity monomers (α-methylstyrene, α-methylstyrene dimer, etc.) can be used, but preferably It is a mercaptan having 4 to 16 carbon atoms.

  The amount of these chain transfer agents to be used is remarkably influenced by the activity of the chain transfer agent, the combination of the monomers, the polymerization conditions, and the like, and must be precisely controlled. It is about 01 mol% to 50 mol%, more preferably 0.05 mol% to 30 mol%, still more preferably 0.08 mol% to 25 mol%.

  These chain transfer agents may be present in the system simultaneously with the target monomer whose degree of polymerization is to be controlled in the polymerization process, and the addition method is not particularly limited. It may be added after being dissolved in the monomer, or may be added separately from the monomer.

  In addition, what has a polymeric group as a substituent is preferable for a fluoropolymer to fix the orientation state of a discotic liquid crystalline compound.

  Specific examples that can be preferably used in the present invention as fluorine-based polymers are shown below, but the present invention is not limited to these specific examples. Here, the numerical values (numerical values such as a, b, c, and d) in the formula are mass percentages indicating the composition ratio of each monomer, and Mw is the mass average molecular weight in terms of PEO measured by GPC.

  The fluoropolymer used in the present invention can be produced by a publicly known and commonly used method. For example, it can be produced by adding a general-purpose radical polymerization initiator to an organic solvent containing the above-mentioned fluorine-based monomer, a monomer having a hydrogen bonding group, and the like, and polymerizing it.

  Further, in some cases, other addition-polymerizable unsaturated compounds can be further added and produced by the same method as described above. Depending on the polymerizability of each monomer, a dropping polymerization method in which a monomer and an initiator are added dropwise to a reaction vessel is also effective for obtaining a polymer having a uniform composition.

  The preferred range of the content of the fluoropolymer in the liquid crystalline composition (liquid crystalline composition excluding the solvent when prepared as a coating liquid) varies depending on the application, but the liquid crystalline composition (coating liquid) In the composition excluding the solvent), it is preferably 0.005 to 8% by mass, more preferably 0.01 to 5% by mass, and 0.05 to 1% by mass. Is more preferable.

  If the addition amount of the fluorine-based polymer is less than 0.005% by mass, the effect is insufficient, and if it exceeds 8% by mass, the coating film cannot be sufficiently dried, or the performance as an optical film (for example, letter Adversely affects the uniformity of the foundation.

  Next, the fluorine-containing compound represented by the formula (III) that can be similarly used as the air interface side vertical alignment agent will be described.

Formula (III)
(R ¹⁰⁰ ) _mo -L ^100- (W) _no
In the formula, R ¹⁰⁰ represents an alkyl group, an alkyl group having a CF ₃ group at the terminal, or an alkyl group having a CF ₂ H group at the terminal, and mo represents an integer of 1 or more. A plurality of R ¹⁰⁰ may be the same or different, but at least one represents an alkyl group having a CF ₃ group or a CF ₂ H group at the terminal. L ¹⁰⁰ represents a (mo + no) -valent linking group, W represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, or phosphonoxy {—OP (═O) (OH) ₂ } Or a salt thereof, and no represents an integer of 1 or more.

In the formula (III), R ¹⁰⁰ functions as a hydrophobic group of the fluorine-containing compound. The alkyl group represented by R ¹⁰⁰ is a substituted or unsubstituted alkyl group, which may be linear or branched, preferably an alkyl group having 1 to 20 carbon atoms, and more preferably Is an alkyl group of 4 to 16, particularly preferably an alkyl group of 6 to 16. As the substituent, any of the substituents exemplified as the substituent group D described later can be applied.

The alkyl group having a CF ₃ group at the terminal represented by R ¹⁰⁰ preferably has 1 to 20 carbon atoms, more preferably 4 to 16 and even more preferably 4 to 8.

The alkyl group having a CF ₃ group at the terminal is an alkyl group in which some or all of the hydrogen atoms contained in the alkyl group are substituted with fluorine atoms. 50% or more of hydrogen atoms in the alkyl group are preferably substituted with fluorine atoms, more preferably 60% or more are substituted, and particularly preferably 70% or more are substituted.

The remaining hydrogen atoms may be further substituted with the substituents exemplified as the substituent group D described later. The alkyl group having a CF ₂ H group at the terminal represented by R ¹⁰⁰ preferably has 1 to 20 carbon atoms, more preferably 4 to 16 and even more preferably 4 to 8.

The alkyl group having a CF ₂ H group at the terminal is an alkyl group in which some or all of the hydrogen atoms contained in the alkyl group are substituted with fluorine atoms. 50% or more of the hydrogen atoms in the alkyl group are preferably substituted with fluorine atoms, more preferably 60% or more are substituted, and even more preferably 70% or more are substituted.

The remaining hydrogen atoms may be further substituted with a substituent exemplified as the substituent group D described later. Examples of an alkyl group having a CF ₃ group at the terminal represented by R ¹⁰⁰ or an alkyl group having a CF ₂ H group at the terminal are shown below.
R1: n-C ₈ F _17-
R2: nC ₆ F _{13-
R3: n-C 4 F 9} -
_{R4: n-C 8 F 17} - (CH 2) 2 -
_{R5: n-C 6 F 13} - (CH 2) 2 -
_{R6: n-C 4 F 9} - (CH 2) 2 -
_{R7: H- (CF 2) 8} -
_{R8: H- (CF 2) 6} -
_{R9: H- (CF 2) 4} -
_{R10: H- (CF 2) 8} - (CH 2) -
R11: H— (CF ₂ ) ₆ — (CH ₂ ) —
R12: H— (CF ₂ ) ₄ — (CH ₂ ) —
In the formula ^(III), the represented by ^{L 100} (mo + no) -valent linking group is an alkylene group, an alkenylene group, an aromatic group, a heterocyclic ^{group, -CO -, - NR d -} (R d are carbon atoms Is a linking group in which at least two groups selected from the group consisting of —O—, —S—, —SO—, and —SO ₂ — are combined.

In the formula (III), W represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, or a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof. . The preferred range of W is the same as Q in formula (II).

  Among the fluorine-containing compounds represented by the formula (III), compounds represented by the following formula (III) -a or formula (III) -b are preferable.

In formula (III) -a, R ¹⁰⁴ and R ¹⁰⁵ each represent an alkyl group, an alkyl group having a CF ₃ group at the terminal, or an alkyl group having a CF ₂ H group at the terminal, and R ¹⁰⁴ and R ¹⁰⁵ are simultaneously It is not an alkyl group.

W ¹ and W ² are each a hydrogen atom, a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, phosphonoxy {—OP (═O) (OH) ₂ } or a salt thereof, or An alkyl group, an alkoxy group or an alkylamino group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent is represented, but W ¹ and W ² are not simultaneously hydrogen atoms.

Formula (III) -b
_{^{(R 106 -L 102 -) m2}} (Ar 101) -W 3
In formula (III) -b, R ¹⁰⁶ represents an alkyl group, an alkyl group having a CF ₃ group at the terminal, or an alkyl group having a CF ₂ H group at the terminal, m2 represents an integer of 1 or more, R ¹⁰⁶ may be the same or different, but at least one represents an alkyl group having a CF ₃ group or a CF ₂ H group at the terminal.

L ¹⁰² represents an alkylene group, an aromatic group, —CO—, —NR′— (R ′ is an alkyl group having 1 to 5 carbon atoms or a hydrogen atom), —O—, —S—, —SO—, It represents a divalent linking group selected from the group consisting of —SO ₂ — and combinations thereof, and the plurality of L ¹⁰² may be the same or different. Ar ¹⁰¹ represents an aromatic hydrocarbon ring or an aromatic heterocycle, W ³ represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof, or an alkyl group, an alkoxy group or an alkylamino group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent.

  First, the formula (III) -a will be described.

R ¹⁰⁴ and R ¹⁰⁵ have the same meaning as R ¹⁰⁰ in formula (III), and the preferred range is also the same. A carboxyl group (—COOH) or a salt thereof represented by W ¹ and W ² , a sulfo group (—SO ₃ H) or a salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof is It is synonymous with W in Formula (III), and its preferable range is also the same.

The alkyl group having a carboxyl group, a sulfo group, or a phosphonoxy group as a substituent represented by W ^{1 or} W ² may be linear or branched, and preferably has 1 to 20 carbon atoms. It is an alkyl group, More preferably, it is a 1-8 alkyl group, Most preferably, it is a 1-3 alkyl group.

The alkyl group having a carboxyl group, a sulfo group, or a phosphonoxy group as the substituent only needs to have at least one carboxyl group, sulfo group, or phosphonoxy group. It is synonymous with the carboxyl group represented by W in Formula (III), a sulfo group, and a phosphonoxy group, and its preferable range is also the same. The alkyl group having a carboxyl group, a sulfo group, or a phosphonoxy group as the substituent may be substituted with any other substituent, and the substituent is any of the substituents exemplified as the substituent group D described later. Can be applied. The alkoxy group having a carboxyl group, a sulfo group, or a phosphonoxy group as a substituent represented by W ^{1 or} W ² may be linear or branched, and preferably has 1 to 20 carbon atoms. An alkoxy group, more preferably an alkoxy group of 1 to 8, and particularly preferably an alkoxy group of 1 to 4.

  The alkoxy group having a carboxyl group, a sulfo group, or a phosphonoxy group as the substituent only needs to have at least one carboxyl group, a sulfo group, or a phosphonoxy group. It is synonymous with the carboxyl group represented by W in Formula (III), a sulfo group, and a phosphonoxy group, and its preferable range is also the same.

The alkoxy group having a carboxyl group, a sulfo group, or a phosphonoxy group may be substituted with other substituents, and any of the substituents exemplified as the substituent group D described later can be applied as the substituent. . The alkylamino group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent represented by W ^{1 or} W ² may be linear or branched, and preferably has 1 to 20 carbon atoms. More preferably 1 to 8 alkylamino groups, and still more preferably 1 to 4 alkylamino groups.

  The alkylamino group having a carboxyl group, a sulfo group, or a phosphonoxy group may have at least one carboxyl group, a sulfo group, or a phosphonoxy group. Examples of the carboxyl group, the sulfo group, and the phosphonoxy group include the above-described formula ( It is synonymous with the carboxyl group represented by W in III), a sulfo group, and a phosphonoxy group, and its preferable range is also the same.

  The alkylamino group having a carboxyl group, a sulfo group, or a phosphonoxy group may be substituted with other substituents, and any of the substituents exemplified as Substituent Group D described later is applied as the substituent. it can.

W ¹ and W ² are particularly preferably each a hydrogen atom or (CH ₂ ) _n SO ₃ M (n represents 0 or 1). M represents a cation, but M may not be present when the charge is 0 in the molecule.

  As cations represented by M, for example, protonium ions, alkali metal ions (lithium ions, sodium ions, potassium ions, etc.), alkaline earth metal ions (barium ions, calcium ions, etc.), ammonium ions and the like are preferably applied. . Of these, proton ions, lithium ions, sodium ions, potassium ions, and ammonium ions are particularly preferable.

  Next, the formula (III) -b will be described.

R ¹⁰⁶ has the same meaning as R ¹⁰⁰ in formula (III) -b, and the preferred range thereof is also the same. L ¹⁰² is preferably an alkylene group having 1 to 12 carbon atoms, an aromatic group having 6 to 12 carbon atoms, —CO—, —NR—, —O—, —S—, —SO—, —SO ₂ — and Represents a linking group having a total carbon number of 0 to 40 consisting of a combination thereof, more preferably an alkylene group having 1 to 8 carbon atoms, a phenyl group, —CO—, —NR—, —O—, —S—, —SO. ₂ represents a linking group having 0 to 20 carbon atoms and a combination thereof. Ar ¹⁰¹ preferably represents an aromatic hydrocarbon ring having 6 to 12 carbon atoms, more preferably a benzene ring or a naphthalene ring.

As a carboxyl group (—COOH) or a salt thereof represented by W ³ , a sulfo group (—SO ₃ H) or a salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof, or a substituent The alkyl group, alkoxy group, or alkylamino group having a carboxyl group, a sulfo group or a phosphonoxy group is a carboxyl group (—COOH) represented by W ¹ and W ² in the formula (III) -a or a salt thereof, sulfo Group (—SO ₃ H) or a salt thereof, phosphonoxy {—OP (═O) (OH) ₂ } or a salt thereof, or an alkyl group, an alkoxy group, or an alkyl having a carboxyl group, a sulfo group, or a phosphonoxy group as a substituent It is synonymous with an amino group and its preferable range is also the same.

W ³ is preferably a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, or a carboxyl group (—COOH) or a salt thereof or a sulfo group (—SO ₃ H) as a substituent. or an alkylamino group having a salt thereof, particularly preferably SO ₃ M or CO ₂ M.

  M represents a cation, but M may not be present when the charge is 0 in the molecule. As cations represented by M, for example, protonium ions, alkali metal ions (lithium ions, sodium ions, potassium ions, etc.), alkaline earth metal ions (barium ions, calcium ions, etc.), ammonium ions and the like are preferably applied. . Of these, proton ions, lithium ions, sodium ions, potassium ions, and ammonium ions are particularly preferable.

In the present specification, the substituent group D includes an alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms, such as a methyl group. , Ethyl group, isopropyl group, tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (preferably having 2 carbon atoms) -20, more preferably an alkenyl group having 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a 2-butenyl group, and a 3-pentenyl group), alkynyl A group (preferably an alkynyl group having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, still more preferably 2 to 8 carbon atoms, Argyl group, 3-pentynyl group and the like), an aryl group (preferably an aryl group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and further preferably 6 to 12 carbon atoms). Group, p-methylphenyl group, naphthyl group and the like), substituted or unsubstituted amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, and further preferably 0 to 6 carbon atoms). An amino group, for example, an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, a dibenzylamino group and the like),
An alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, still more preferably 1 to 8 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, and a butoxy group). An aryloxy group (preferably an aryloxy group having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, still more preferably 6 to 12 carbon atoms, and examples thereof include a phenyloxy group and a 2-naphthyloxy group. An acyl group (preferably an acyl group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and still more preferably 1 to 12 carbon atoms, such as an acetyl group, a benzoyl group, a formyl group, and a pivaloyl group. Etc.), an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably A C2-C12 alkoxycarbonyl group, for example, a methoxycarbonyl group, an ethoxycarbonyl group, and the like; an aryloxycarbonyl group (preferably having a carbon number of 7-20, more preferably having a carbon number of 7-16, even more preferably Is an aryloxycarbonyl group having 7 to 10 carbon atoms, such as a phenyloxycarbonyl group, and an acyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and still more preferably carbon atoms). An acyloxy group having a number of 2 to 10, and examples thereof include an acetoxy group and a benzoyloxy group).

  An acylamino group (preferably an acylamino group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably 2 to 10 carbon atoms, such as an acetylamino group and a benzoylamino group), alkoxycarbonyl An amino group (preferably an alkoxycarbonylamino group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably 2 to 12 carbon atoms, such as a methoxycarbonylamino group), aryloxy Carbonylamino group (preferably an aryloxycarbonylamino group having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, still more preferably 7 to 12 carbon atoms, such as a phenyloxycarbonylamino group) A sulfonylamino group (preferably having 1 to 20 carbon atoms) Preferably it is a C1-C16, More preferably, it is a C1-C12 sulfonylamino group, for example, a methanesulfonylamino group, a benzenesulfonylamino group, etc.), a sulfamoyl group (preferably C0-20). More preferably, it is a sulfamoyl group having 0 to 16 carbon atoms, more preferably 0 to 12 carbon atoms, and examples thereof include a sulfamoyl group, a methylsulfamoyl group, a dimethylsulfamoyl group, and a phenylsulfamoyl group. ), A carbamoyl group (preferably a carbamoyl group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and still more preferably 1 to 12 carbon atoms, such as an unsubstituted carbamoyl group, a methylcarbamoyl group, or a diethylcarbamoyl group. Group, phenylcarbamoyl group, etc.), al A ruthio group (preferably an alkylthio group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms, such as a methylthio group and an ethylthio group), an arylthio group ( Preferably it is a C6-C20, More preferably, it is a C6-C16, More preferably, it is a C6-C12 arylthio group, For example, a phenylthio group etc. are mentioned, A sulfonyl group (preferably C1-C1). 20, more preferably a sulfonyl group having 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms, and examples thereof include a mesyl group and a tosyl group), a sulfinyl group (preferably having a carbon number of 1 to 20, and more. Preferably it is a C1-C16, More preferably, it is a C1-C12 sulfinyl group, for example, a methane sulfinyl group, A benzenesulfinyl group), a ureido group (preferably a ureido group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms, for example, an unsubstituted ureido group , Methylureido group, phenylureido group, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and further preferably 1 to 12 carbonic acid amide groups). Yes, for example, diethyl phosphoric acid amide group, phenyl phosphoric acid amide group, etc.), hydroxy group, mercapto group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, Carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably carbon 1-30, more preferably 1-12, for example, a heterocyclic group having a heteroatom such as a nitrogen atom, oxygen atom, sulfur atom, etc., for example, an imidazolyl group, a pyridyl group, a quinolyl group, A furyl group, a piperidyl group, a morpholino group, a benzoxazolyl group, a benzimidazolyl group, a benzthiazolyl group, and the like, and a silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, still more preferable). Is a silyl group having 3 to 24 carbon atoms, and examples thereof include a trimethylsilyl group and a triphenylsilyl group. These substituents may be further substituted with these substituents. Further, when two or more substituents are present, they may be the same or different. If possible, they may be bonded to each other to form a ring.

  The fluorine-containing compound preferably has a polymerizable group as a substituent in order to fix the orientation state of the discotic liquid crystalline compound.

  Specific examples of the fluorine-containing compound represented by the formula (III) that can be used in the present invention are shown below, but the fluorine-containing compound used in the present invention is not limited thereto.

  The preferable range of the content of the fluorine-containing compound in the liquid crystal composition varies depending on the use, but 0.005 to 0.005 in the liquid crystal composition (a composition excluding the solvent in the case of a coating liquid). The content is preferably 8% by mass, more preferably 0.01 to 5% by mass, and still more preferably 0.05 to 1% by mass.

(Polymerization initiator)
It is preferable to fix the molecules of the liquid crystal compound aligned in a desired alignment state (for example, vertical alignment in the case of a rod-like liquid crystal compound) while maintaining the alignment state.

  The immobilization is preferably performed by a polymerization reaction of the polymerizable group (P) introduced into the liquid crystal compound.

  The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator. A photopolymerization reaction is preferred. Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatic acyloin. Compound (described in US Pat. No. 2,722,512), polynuclear quinone compound (described in US Pat. Nos. 3,046,127 and 2,951,758), a combination of triarylimidazole dimer and p-aminophenyl ketone (US Pat. No. 3,549,367) Description), acridine and phenazine compounds (JP-A-60-105667, U.S. Pat. No. 4,239,850) and oxadiazole compounds (U.S. Pat. No. 4,212,970).

  The amount of the photopolymerization initiator used is preferably 0.01 to 20% by mass, more preferably 0.5 to 5% by mass, based on the solid content of the coating solution.

(Other additives for the first optically anisotropic layer)
Along with the liquid crystal compound, a plasticizer, a surfactant, a polymerizable monomer, and the like can be used in combination to improve the uniformity of the coating film, the strength of the film, the orientation of the liquid crystal compound, and the like. These materials are preferably compatible with the liquid crystal compound and do not inhibit the alignment.

  Examples of the polymerizable monomer include radically polymerizable or cationically polymerizable compounds. Preferably, it is a polyfunctional radically polymerizable monomer and is preferably copolymerizable with the above-described polymerizable group-containing liquid crystal compound.

  Examples thereof include those described in paragraph numbers [0018] to [0020] in JP-A No. 2002-296423. The amount of the compound added is generally in the range of 1 to 50% by mass and preferably in the range of 5 to 30% by mass with respect to the discotic liquid crystalline molecules.

  Examples of the surfactant include conventionally known compounds, and fluorine compounds are particularly preferable. Specifically, for example, compounds described in paragraphs [0028] to [0056] in JP-A No. 2001-330725, and compounds described in paragraphs [0069] to [0126] in Japanese Patent Application No. 2003-295212. Is mentioned.

  The polymer used together with the liquid crystal compound is preferably capable of thickening the coating solution. A cellulose ester can be mentioned as an example of a polymer.

  Preferable examples of the cellulose ester include those described in paragraph [0178] of JP-A No. 2000-155216. The addition amount of the polymer is preferably in the range of 0.1 to 10% by mass, and in the range of 0.1 to 8% by mass with respect to the liquid crystal molecules so as not to inhibit the alignment of the liquid crystal compound. It is more preferable.

  The first optically anisotropic layer is, for example, a coating liquid prepared by dissolving and / or dispersing a liquid crystalline compound and additives such as a polymerization initiator and an alignment controller added as required in a solvent. It can be formed by coating on a support.

  It is preferable to form an alignment film on a support and apply the coating solution on the surface of the alignment film. As the solvent used for preparing the coating solution, an organic solvent is preferably used.

Examples of organic solvents include amides (eg, N, N-dimethylformamide), sulfoxides (eg, dimethyl sulfoxide), heterocyclic compounds (eg, pyridine), hydrocarbons (eg, benzene, hexane), alkyl halides (eg, , Chloroform, dichloromethane), esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane). Alkyl halides and ketones are preferred. Two or more organic solvents may be used in combination.
(Application method)
The coating liquid can be applied by a known method (eg, wire bar coating method, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method). Especially, when forming the said 1st optically anisotropic layer, it is preferable to apply | coat using a wire bar coating method, and it is preferable that the rotation speed of a wire bar satisfy | fills a following formula.

0.6 <(W × (R + 2r) × π) / V <1.4
[W: Number of rotations of wire bar (rpm), R: Diameter of core of bar (m), r: Diameter of wire (m), V: Conveying speed of support (m / min)]
The range of (W × (R + 2r) × π) / V is more preferably 0.7 to 1.3, and still more preferably 0.8 to 1.2.

  A die coating method is preferably used for forming the first optically anisotropic layer, and a coating method using a slide coater or a slot die coater is particularly preferable.

  For example, the coating methods described in JP-A No. 2004-290775, JP-A No. 2004-290776, JP-A No. 2004-358296, JP-A No. 2005-13989, and the like can be used.

  Next, as described above, after the composition is applied to the surface of the support or the alignment film, the molecules of the liquid crystalline compound are aligned (preferably vertical alignment for rod-like liquid crystalline molecules), and the molecules are aligned. To form an optically anisotropic layer.

  The alignment temperature can be determined in consideration of the transition temperature of the liquid crystal compound to be used, the desired alignment state, and the like. The immobilization is preferably carried out by a polymerization reaction or a crosslinking reaction of liquid crystalline molecules or a polymerizable monomer that is optionally added to the composition.

It is preferable to use ultraviolet rays for light irradiation for polymerization. The irradiation energy ^is preferably ^{20mJ / cm 2 ~50J / cm 2} , further preferably 100 to 800 mJ / cm ^2. In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions.

The thickness of the formed optically anisotropic layer is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm, and still more preferably 1 to 5 μm.
(Alignment film)
When forming the first optically anisotropic layer, it is preferable to align the molecules of the liquid crystalline compound by coating the composition on the surface of the alignment film. Since the alignment film has a function of defining the alignment direction of the liquid crystalline compound, it is preferably used for realizing a preferred embodiment of the present invention.

  However, if the alignment state is fixed after aligning the liquid crystalline compound, the alignment film plays the role, and thus is not necessarily an essential component of the present invention. That is, it is possible to produce the polarizing plate of the present invention by transferring only the optically anisotropic layer on the alignment film in which the alignment state is fixed onto the polarizer.

  The alignment film is an organic compound (eg, ω-tricosanoic acid) formed by rubbing treatment of an organic compound (preferably a polymer), oblique deposition of an inorganic compound, formation of a layer having a microgroove, or Langmuir-Blodgett method (LB film). , Dioctadecylmethylammonium chloride, methyl stearylate).

  Furthermore, an alignment film in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known.

  The alignment film is preferably formed by polymer rubbing treatment.

  Examples of the polymer include methacrylate copolymer, styrene copolymer, polyolefin, polyvinyl alcohol, modified polyvinyl alcohol, poly (N-methylol) described in paragraph No. [0022] of JP-A-8-338913. Acrylamide), polyester, polyimide, vinyl acetate copolymer, carboxymethylcellulose, polycarbonate and the like. Silane coupling agents can be used as the polymer. Water-soluble polymers (eg, poly (N-methylolacrylamide), carboxymethylcellulose, gelatin, polyvinyl alcohol, modified polyvinyl alcohol) are preferred, gelatin, polyvinyl alcohol and modified polyvinyl alcohol are more preferred, and polyvinyl alcohol and modified polyvinyl alcohol are most preferred. .

  The saponification degree of polyvinyl alcohol is preferably 70 to 100%, more preferably 80 to 100%. The polymerization degree of polyvinyl alcohol is preferably 100 to 5000.

  The alignment film that can be used for the production of the first optically anisotropic layer binds a side chain having a crosslinkable functional group (eg, a double bond) to the main chain, or aligns liquid crystal molecules. It is preferable to introduce a crosslinkable functional group having a function into the side chain.

  As the polymer used for the alignment film, either a polymer that can be crosslinked by itself or a polymer that is crosslinked by a crosslinking agent can be used, and a plurality of combinations thereof can be used.

  When a side chain having a crosslinkable functional group is bonded to the main chain of the alignment film polymer, or a crosslinkable functional group is introduced into a side chain having a function of aligning liquid crystalline molecules, the alignment film polymer and the optically anisotropic film The polyfunctional monomer contained in the conductive layer can be copolymerized.

  As a result, not only between the polyfunctional monomer and the polyfunctional monomer, but also between the alignment film polymer and the alignment film polymer and between the polyfunctional monomer and the alignment film polymer is firmly bonded by a covalent bond.

  Therefore, the strength of the retardation film can be remarkably improved by introducing the crosslinkable functional group into the alignment film polymer.

  The crosslinkable functional group of the alignment film polymer preferably contains a polymerizable group in the same manner as the polyfunctional monomer. Specific examples include those described in paragraphs [0080] to [0100] in JP-A-2000-155216.

  Apart from the crosslinkable functional group, the alignment film polymer can also be crosslinked using a crosslinking agent. Examples of the crosslinking agent include aldehydes, N-methylol compounds, dioxane derivatives, compounds that act by activating carboxyl groups, active vinyl compounds, active halogen compounds, isoxazole and dialdehyde starch.

  Two or more kinds of crosslinking agents may be used in combination. Specific examples include compounds described in paragraphs [0023] to [0024] in JP-A-2002-62426. Aldehydes having high reaction activity, particularly glutaraldehyde are preferred.

  0.1-20 mass% is preferable with respect to a polymer, and, as for the addition amount of a crosslinking agent, 0.5-15 mass% is more preferable. The amount of the unreacted crosslinking agent remaining in the alignment film is preferably 1.0% by mass or less, and more preferably 0.5% by mass or less.

  By adjusting in this way, even if the alignment film is used for a long time in a liquid crystal display device or left in a high temperature and high humidity atmosphere for a long time, sufficient durability without reticulation can be obtained.

  The alignment film is basically formed by applying a solution containing the polymer, the cross-linking agent, and the additive, which is an alignment film forming material, onto a transparent support, followed by heat drying (cross-linking) and rubbing treatment. be able to.

  As described above, the crosslinking reaction may be performed at any time after coating on the transparent support. When a water-soluble polymer such as polyvinyl alcohol is used as the alignment film forming material, the coating solution is preferably a mixed solvent of an organic solvent (eg, methanol) having a defoaming action and water. The ratio of water: methanol is preferably 0: 100 to 99: 1, and more preferably 0: 100 to 91: 9. Thereby, generation | occurrence | production of a bubble is suppressed and the defect of the layer surface of an orientation film and also an optically anisotropic layer reduces remarkably.

  As a coating method used for preparing the alignment film, a spin coating method, a dip coating method, a curtain coating method, an extrusion coating method, a rod coating method or a roll coating method is preferable. A rod coating method is particularly preferable. The film thickness after drying is preferably 0.1 to 10 μm.

  Heating and drying can be performed at 20 ° C to 110 ° C. In order to form sufficient cross-linking, 60 ° C to 100 ° C is preferable, and 80 ° C to 100 ° C is particularly preferable. The drying time can be 1 minute to 36 hours, preferably 1 minute to 30 minutes.

  The pH is preferably set to an optimum value for the crosslinking agent to be used. When glutaraldehyde is used, the pH is 4.5 to 5.5, and 5 is particularly preferable.

  The alignment film is preferably provided on the transparent support. The alignment film can be obtained by rubbing the surface after crosslinking the polymer layer as described above.

  For the rubbing treatment, a treatment method widely adopted as a liquid crystal alignment treatment process of LCD can be applied.

  That is, a method of obtaining the orientation by rubbing the surface of the orientation film in a certain direction using paper, gauze, felt, rubber, nylon, polyester fiber or the like can be used. In general, it is carried out by rubbing several times using a cloth in which fibers having a uniform length and thickness are flocked on average.

  The said composition is apply | coated to the rubbing process surface of alignment film, and the molecule | numerator of a liquid crystalline compound is aligned. Thereafter, if necessary, the alignment film polymer and the polyfunctional monomer contained in the optically anisotropic layer are reacted, or the alignment film polymer is crosslinked using a cross-linking agent, thereby allowing the first optical difference. An isotropic layer can be formed.

  The thickness of the alignment film is preferably in the range of 0.1 to 10 μm.

(Support)
As the support for forming the first optically anisotropic layer made of a liquid crystalline composition, the second optically anisotropic layer made of a specific cellulose acylate film may be used. After the first optical anisotropic layer is provided on the support, it may be transferred onto the second optical anisotropic layer, or an optically isotropic film may be used as the support separately. Also good.

  When a temporary support is used, the optical properties of the support are not particularly limited, but it is preferable that the first optical anisotropic layer can be easily peeled off.

  When the first optically anisotropic layer is formed on an optically isotropic support, the support may be removed or left when used in a liquid crystal display device. The support can also be used as a protective film for a polarizer. The support preferably has a light transmittance of 80% or more.

  As a substantially isotropic support, the in-plane retardation (Ro) is preferably 0 to 20 nm, more preferably 0 to 10 nm, and most preferably 0 to 5 nm.

  The retardation in the thickness direction (Rt) is preferably -60 nm to 60 nm, preferably -40 nm to 40 nm, and most preferably -20 nm to 20 nm. The chromatic dispersion is preferably such that the ratio of Ro400 / Ro700 is less than 1.2.

  Examples of the polymer include cellulose ester, polycarbonate, polysulfone, polyethersulfone, polyacrylate, polymethacrylate and cyclic polyolefin. Cellulose esters are preferred, acetyl cellulose is more preferred, and triacetyl cellulose is most preferred.

  As the cyclic polyolefin, a polymer obtained by hydrogenation reaction of a ring-opening polymer of tetracyclododecene or a ring-opening copolymer of tetracyclododecene and norbornene described in JP-B-2-9619 Can be used from the series of Arton (manufactured by JSR), Zeonex, and Zeonore (manufactured by Nippon Zeon). The polymer film is preferably formed by a solution casting film forming method.

  The thickness of the transparent support is preferably 20 to 500 μm, and more preferably 50 to 200 μm. In order to improve adhesion between the transparent support and the layer (adhesive layer, vertical alignment film or retardation layer) provided thereon, surface treatment (eg, glow discharge treatment, corona discharge treatment, ultraviolet light (UV) ) Treatment, flame treatment).

An adhesive layer (undercoat layer) may be provided on the transparent support. Moreover, the average particle diameter is 10 to 100 nm in order to give the transparent support or the long transparent support a slip property in the transport process or to prevent the back surface and the surface from sticking after winding. It is preferable to use what formed the polymer layer which mixed the inorganic particle of about 5%-40% by solid content mass ratio on the one side of the support body by application | coating or co-casting with a support body.
<Polarizing plate>
The polarizing plate of the present invention includes a polarizer and the retardation film of the present invention.

  As the polarizer, an iodine polarizer, a dye polarizer using a dichroic dye, or a polyene polarizer can be used.

  The iodine polarizer and the dye polarizer are generally produced using a polyvinyl alcohol film. The absorption axis of the polarizer corresponds to the stretching direction of the film. Accordingly, a polarizer stretched in the longitudinal direction (transport direction) has an absorption axis parallel to the longitudinal direction, and a polarizer stretched in the lateral direction (perpendicular to the transport direction) is perpendicular to the longitudinal direction. Has an absorption axis.

  The preferable manufacturing method of the polarizing plate of this invention includes the process of laminating | stacking a polarizer and retardation film continuously in a respectively elongate state. The long polarizing plate is cut according to the screen size of the liquid crystal display device used.

  A polarizer generally has a protective film on both surfaces. The cellulose ester film contained in the retardation film of the present invention can function as a protective film for a polarizer. In such a case, it is necessary to separately bond a protective film to the surface of the polarizer on the retardation film side. There is no.

  In the polarizing plate of the present invention, an isotropic adhesive layer and / or a substantially isotropic transparent protection is provided between the polarizer and the cellulose ester film (one member of the retardation film of the present invention). Preferably only the film is included.

  Specifically, the substantially isotropic transparent protective film is a film having an in-plane retardation Ro of 0 to 10 nm and a thickness direction retardation Rt of 20 to 20 nm. Films containing cellulose esters or cyclic polyolefins are preferred.

  In a first aspect of the polarizing plate of the present invention, the first optical anisotropic layer, the second optical anisotropic layer, and the polarizer are laminated in this order, and the first 2 is a polarizing plate in which the direction of the slow axis of the optically anisotropic layer and the direction of the absorption axis of the polarizer are substantially orthogonal, and the second aspect of the polarizing plate of the present invention is: The second optical anisotropic layer, the first optical anisotropic layer, and the polarizer are laminated in this order, and the slow axis of the second optical anisotropic layer It is a polarizing plate in which the direction and the direction of the absorption axis of the polarizer are substantially parallel.

The direction of the slow axis of the 2nd optically anisotropic layer which consists of a specific cellulose-ester film can be adjusted with the extending | stretching direction at the time of producing a cellulose-ester film.
<Liquid crystal display device>
The liquid crystal display device of the present invention includes at least the polarizing plate of the present invention. The liquid crystal display device of the present invention may be any of a reflection type, a semi-transmission type, a transmission type liquid crystal display device and the like.

  A liquid crystal display device generally includes a polarizing plate, a liquid crystal cell, and a retardation plate, a reflection layer, a light diffusion layer, a backlight, a front light, a light control film, a light guide plate, a prism sheet, a color filter, and the like as necessary. Although comprised from a member, in this invention, there is no restriction | limiting in particular except the point which makes it essential to use the polarizing plate of this invention.

  The liquid crystal cell is not particularly limited, and a general liquid crystal cell such as a liquid crystal layer sandwiched between a pair of transparent substrates provided with electrodes can be used. The transparent substrate constituting the liquid crystal cell is not particularly limited as long as the liquid crystal material constituting the liquid crystal layer is aligned in a specific alignment direction.

  Specifically, a transparent substrate in which the substrate itself has a property of orienting liquid crystals, a transparent substrate in which an alignment film having the property of orienting liquid crystals is provided, but the substrate itself lacks the alignment ability. Either can be used.

  Moreover, a well-known thing can be used for the electrode of a liquid crystal cell. Usually, it can be provided on the surface of the transparent substrate in contact with the liquid crystal layer, and when a substrate having an alignment film is used, it can be provided between the substrate and the alignment film.

  The material exhibiting liquid crystallinity for forming the liquid crystal layer is not particularly limited, and examples thereof include various ordinary low-molecular liquid crystalline compounds, high-molecular liquid crystalline compounds, and mixtures thereof that can constitute various liquid crystal cells. Moreover, a pigment | dye, a chiral agent, a non-liquid crystalline compound, etc. can also be added to these in the range which does not impair liquid crystallinity.

  In addition to the electrode substrate and the liquid crystal layer, the liquid crystal cell may include various components necessary for forming various types of liquid crystal cells described later.

  As a method of the liquid crystal cell, a TN (Twisted Nematic) method, a STN (Super Twisted Nematic) method, an ECB (Electrically Controlled Bi-Floringence) method, an IPS (In-Plane Switching) method, a V (In-Plane Switching) method, a VA (In-Plane Switching) method, an VA (In-Plane Switching) method, a VA (In-Plane Switching) method, an A-V (In-Plane Switching) method, Vertical Alignment (PVA) method, PVA (Patterned Vertical Alignment) method, OCB (Optically Compensated BiRoofingence) method, HAN (Hybrid Aligned Nematic) method, ASMr Aligned Nematic Crocell) method, a halftone gray scale method, the domain division method or a ferroelectric liquid crystal, various methods such as a display system using an antiferroelectric liquid crystal and the like.

  The driving method of the liquid crystal cell is not particularly limited, and a passive matrix method used for STN-LCD and the like, and an active matrix method using an active electrode such as a TFT (Thin Film Transistor) electrode and a TFD (Thin Film Diode) electrode, Any driving method such as a plasma addressing method may be used. A field sequential method that does not use a color filter may be used.

  The polarizing plate of the present invention is preferably used for reflective, transflective, and transmissive liquid crystal display devices. A reflective liquid crystal display device usually has a configuration in which a reflector, a liquid crystal cell, and a polarizing plate are laminated in this order. The retardation plate is disposed between the reflector and the polarizer (between the reflector and the liquid crystal cell or between the liquid crystal cell and the polarizer).

  The reflector may share the liquid crystal cell and the substrate. As the polarizing plate, the polarizing plate of the present invention can be used. In such a case, the retardation plate may not be separately provided.

  The transflective liquid crystal display device includes a liquid crystal cell, a polarizing plate disposed on the viewer side of the liquid crystal cell, and at least one retardation plate disposed between the polarizing plate and the liquid crystal cell. And at least one transflective layer disposed behind the liquid crystal layer as viewed from the viewer, and at least one retardation plate and polarizing plate behind the transflective layer as viewed from the viewer And have.

  In this type of liquid crystal display device, it is possible to use both a reflection mode and a transmission mode by installing a backlight. Both polarizing plates may be the polarizing plate of the present invention, or only one of them may be the polarizing plate of the present invention.

  When the polarizing plate of the present invention is arranged, a retardation plate may not be separately arranged between the liquid crystal cell and the polarizing plate of the present invention.

  The mode of the liquid crystal cell is not particularly limited, but is preferably an IPS mode or an FFS mode.

  In an IPS mode liquid crystal cell, rod-like liquid crystal molecules are aligned substantially parallel to the substrate, and the liquid crystal molecules respond in a planar manner when an electric field parallel to the substrate surface is applied.

  In the IPS mode, black is displayed when no electric field is applied, and the transmission axes of the pair of upper and lower polarizing plates are orthogonal. JP-A-10-54982, JP-A-11-202323, JP-A-9-292522 are disclosed in which a retardation film is used to reduce leakage light during black display in an oblique direction and to improve the viewing angle. No. 11-133408, No. 11-305217, No. 10-307291, and the like.

  For example, the polarizing plate according to the first aspect includes a pair of substrates and a liquid crystal cell in which liquid crystal molecules sandwiched between the pair of substrates are aligned substantially parallel to the substrate during black display. When used in a liquid crystal display device having an IPS mode liquid crystal cell (for example, an IPS mode liquid crystal cell), the first optical anisotropic layer and the second optical anisotropic layer are formed on the outside of one of the pair of substrates from the substrate side. The polarizing plate is arranged so that the light-sensitive layer and the polarizer are in this order, and the slow axis of the second optically anisotropic layer is substantially parallel to the major axis direction of the liquid crystal molecules during black display. And a second polarizer can be further disposed outside the other substrate. In this case, the absorption axes of both polarizers are arranged so as to be orthogonal to each other.

  The polarizing plate of the second aspect includes a pair of substrates and a liquid crystal layer in which liquid crystal molecules sandwiched between the pair of substrates are aligned substantially parallel to the substrate during black display. When used in a liquid crystal display device having an IPS mode liquid crystal cell (for example, an IPS mode liquid crystal cell), the second optical anisotropic layer and the first optical anisotropy are formed on the outside of one of the pair of substrates from the substrate side. The polarizing plate is arranged so that the light-sensitive layer and the polarizer are in this order, and the slow axis of the second optically anisotropic layer and the major axis direction of the liquid crystal molecules during black display are substantially perpendicular to each other. In addition, a second polarizer can be further disposed outside the other substrate.

  In this case, the absorption axes of both polarizers are arranged to be orthogonal to each other. Also in this case, both polarizers are arranged so that the absorption axes thereof are orthogonal to each other.

  In any of the above embodiments, only a substantially isotropic adhesive layer and / or a substantially isotropic transparent protective film is included between the second polarizer and the substrate. It is preferable.

  Specifically, the substantially isotropic transparent protective film has an in-plane retardation Ro of 0 to 10 nm and a thickness direction retardation Rt of 20 to 20 nm, and has such optical characteristics, for example. Films containing cellulose esters or cyclic polyolefins are preferred.

The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention.
Example 1
<Production of second optically anisotropic layers (C1) to (C4)>
(Second optically anisotropic layer (C1))
A cellulose ester film corresponding to the second optically anisotropic layer (C1) was produced as follows.

First, a dope (cellulose ester solution) having the following composition was prepared.
(Cellulose ester dope composition)
Cellulose acetate propionate CE1 100 parts by mass (acetyl group substitution degree (A) 1.95, propionyl group substitution degree (B) 0.7)
Triphenyl phosphate 10 parts by mass Ethylphthalyl ethyl glycolate 2 parts by mass Tinuvin 326 (manufactured by Ciba Japan) 1 part by mass AEROSIL 200V (manufactured by Nippon Aerosil Co., Ltd.) 0.1 part by mass Methylene chloride 300 parts by mass Ethanol 40 parts by weight Cellulose acetate having an acetylation degree of 60.9% (degree of polymerization 300, Mn / Mw = 1.5) 100 parts by weight Triphenyl phosphate (plasticizer) 7.8 parts by weight Biphenyl diphenyl phosphate (plasticizer) 3.9 parts by mass Methylene chloride (first solvent) 300 parts by mass Methanol (second solvent) 54 parts by mass 1-butanol (third solvent) 11 parts by mass After raising the temperature from 20 ° C. to 80 ° C., the mixture was stirred for 3 hours while maintaining the temperature at 80 ° C. The cellulose acetate propionate was completely dissolved.

  Then, stirring was stopped and the liquid temperature was lowered to 43 ° C. The dope was filtered using a filter paper (Azumi filter paper No. 244, manufactured by Azumi Filter Paper Co., Ltd.) to obtain a dope.

  The dope prepared as described above is cast through a casting die kept at 30 ° C. onto a 30 ° C. support made of a stainless steel endless belt to form a web (dope film), and finally After drying on the support until the residual solvent amount in the web reached 80% by mass, the web was peeled from the support with a peeling roll.

  Next, the web is dried with a drying air flow of 120 ° C. in a roll conveying and drying process arranged in a staggered manner, and subsequently introduced into a tenter, and both ends of the web are sandwiched with clips, and under the condition where residual solvent is present, The film was stretched in the width direction and dried by applying a drying air.

  At this time, the film (web) is stretched in the TD direction (width direction), and at the same time, the TD direction stretch rate (%) × 0.1 to the TD direction stretch rate (%) × 0.3 in the MD direction range. Stretching at a TD stretch rate of 20% was performed by changing the shrinkage rate in the MD direction (longitudinal direction) so as to perform relaxation shrinkage.

  Moreover, the atmospheric temperature of the dry part between tenters was changed from peeling, and the residual solvent amount at the time of film stretching was changed. The amount of residual solvent of the film at the time of stretching was measured by sampling a part of the film (base) in a tenter.

  Further, the web (film) is dried with a drying air of 100 ° C. in a roll conveyance drying process arranged in a staggered manner, wound up by a winder, and finally a cellulose acetate propionate film having a film thickness of 50 μm is produced. did.

  In this cellulose acetate propionate film (C1), the amount of residual solvent during film stretching was 5%. Further, the relaxation shrinkage in the MD direction of the film was set to -3%.

Further, in this cellulose acetate propionate film (C1), the gripping length of each clip that grips both ends of the film during stretching in the TD direction was 100 mm (10% of the film width).
(Second Optically Anisotropic Layer Comparison Example 1C1 of JP 2007-155972 A)
A comparative optical film having a thickness after drying of 60 μm was prepared in the same manner as in (C1) except that 100 parts by mass of cellulose acetate having an acetyl group substitution degree of 2.66 was used as the cellulose ester.
<Production of second optically anisotropic layers (C2) to (C4)>
Cellulose esters with different types of acyl groups and different degrees of substitution described in Table 1 were prepared. This was carried out by adding sulfuric acid (7.8 parts by mass with respect to 100 parts by mass of cellulose) as a catalyst, adding carboxylic acid as a raw material for the acyl substituent, and carrying out an acylation reaction at 40 ° C.

  At this time, the kind and substitution degree of the acyl group were adjusted by adjusting the kind and amount of the carboxylic acid. Moreover, it age | cure | ripened at 40 degreeC after acylation.

Furthermore, the low molecular weight component of the cellulose ester was removed by washing with acetone.
(Dissolution (preparation of dope))
The cellulose ester shown in Table 1 was added to the following mixed solvent, dichloromethane / methanol (87/13 parts by mass) with stirring so that the mass concentration of cotton was 15% by mass, and heated to stir to dissolve.

  At the same time, 7.8 parts by mass of triphenyl phosphate (TPP) and 3.9 parts by mass of biphenyl diphenyl phosphate (BDP) as plasticizers are respectively added to 100 parts by mass of the cellulose ester, and 5 parts by mass of the following retardation regulator. , Matting agent (silicon dioxide (primary particle diameter 20 nm), Mohs hardness about 7) 0.05 parts by mass, UV absorber B (TINUVIN327, manufactured by Ciba Japan Co., Ltd.) 0.375 parts by mass, UV absorption 0.75 parts by mass of Agent C (TINUVIN 328, manufactured by Ciba Japan Co., Ltd.) was added and stirred while heating to prepare a dope.

(Casting)
The above dope was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of 25 to 35% by mass was stretched in the range of about Tg (see Table 1) -5 to Tg (see Table 1) + 5 ° C. with a tenter and 1-1. A cellulose ester film (described in thickness table 2) was produced by stretching in the width direction at a stretching ratio of 6 times (see Table 2). Table 1 shows the stretch ratio of the tenter.

The produced film is passed through a dielectric heating roll having a temperature of 60 ° C., and after the film surface temperature is raised to 40 ° C., an alkaline solution having the following composition is applied by a bar coater to 14 ml / m ² and heated to 110 ° C. After being kept for 10 seconds under the steam type far-infrared heater (manufactured by Noritake Co., Ltd.), 3 ml / m ^{2 of} pure water was similarly applied using a bar coater.

The film temperature at this time was 40 degreeC. Next, washing with a fountain coater and draining with an air knife were repeated three times, and then the film was retained in a drying zone at 70 ° C. for 2 seconds and dried.
<Alkaline solution composition>
Potassium hydroxide 4.7 parts by weight Water 15.7 parts by weight Isopropanol 64.8 parts by weight Propylene glycol 14.9 parts by weight C ₁₆ H ₃₃ O (CH ₂ CH ₂ O) ₁₀ H (surfactant) 1.0 part by weight Part The optical characteristics of the produced cellulose ester film were measured using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments). The results are shown in Table 2. This film was designated as second optically anisotropic layers C1 to C4.

<Production of first optically anisotropic layer>
An alignment film coating solution having the following composition was continuously applied with a # 14 wire bar on the saponified surface of the produced long cellulose ester film (C1). The alignment film was formed by drying with warm air of 60 ° C. for 60 seconds and further with warm air of 100 ° C. for 120 seconds.
(Composition of alignment film coating solution)
The following modified polyvinyl alcohol 10 parts by weight Water 371 parts by weight Methanol 119 parts by weight Glutaraldehyde 0.5 parts by weight

  A coating solution containing a rod-like liquid crystal compound having the following composition was continuously applied onto the prepared alignment film with a # 5.0 wire bar.

  The conveyance speed of the film was 20 m / min. The solvent was dried in a step of continuously heating from room temperature to 80 ° C., and then heated in a drying zone at 80 ° C. for 90 seconds to align the rod-like liquid crystal compound.

  Subsequently, the temperature of the film was maintained at 60 ° C., and the alignment of the liquid crystal compound was fixed by UV irradiation to form the first optical anisotropic layer B1.

  Subsequently, the film prepared in a 1.5 mol / L sodium hydroxide aqueous solution at 55 ° C. was immersed for 2 minutes, and then immersed in water to sufficiently wash away sodium hydroxide. Then, after being immersed for 1 minute in 5 mmol / L sulfuric acid aqueous solution of 35 degreeC, it was immersed in water and the dilute sulfuric acid aqueous solution was fully washed away. Finally, the sample was thoroughly dried at 120 ° C.

  In this way, a retardation film F1 in which the first and second optically anisotropic layers were laminated was produced.

Similarly, the cellulose ester film (C1) was changed to a cellulose ester film (C2 to C4), respectively, and retardation films F2 to F4 were produced.
(Composition of coating liquid (S1) containing rod-like liquid crystal compound)
The following rod-like liquid crystalline compound (I) 100 parts by mass Photopolymerization initiator (Irgacure 907, manufactured by Ciba Japan Co., Ltd.) 3 parts by mass Sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1 part by mass 0.4 parts by mass of the following fluorine-based polymer 1 part by mass of the following pyridinium salt 172 parts by mass of methyl ethyl ketone

  Only the optically anisotropic layer containing the rod-like liquid crystalline compound was peeled from the produced retardation film F1, and the optical characteristics were measured using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments). .

The Ro of only the optically anisotropic layer measured at a wavelength of 590 nm was 0 nm, and Rt was −260 nm. It was also confirmed that an optically anisotropic layer in which rod-like liquid crystal molecules were aligned substantially perpendicular to the film surface was formed.
Example 2
<Preparation of Polarizing Plate (P1-4)>
A roll-shaped polyvinyl alcohol film having a thickness of 80 μm continuously dyed in an aqueous iodine solution was stretched 5 times in the transport direction and dried to obtain a long polarizer.

  One surface of the polarizer is the surface on which the first optically anisotropic layer of the produced retardation film F1 is not formed, and the other surface is a saponified cellulose triacetate film (Konica Minolta Attack). KC4UY (manufactured by Konica Minolta Opto Co., Ltd.) was continuously bonded using a polyvinyl alcohol-based adhesive to produce a long polarizing plate P1.

  At this time, the absorption axis of the polarizer is parallel to the longitudinal direction, and the angle formed by the absorption axis of the polarizer and the slow axis of the second optical anisotropic layer (cellulose ester film) is 90 °. Met.

Similarly, the retardation film F1 was changed to the said retardation films F2-4, and the elongate polarizing plate P2-4 was produced.
<Production of cellulose acetate film (T0)>
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose triacetate solution A.
(Preparation of cellulose triacetate solution A)
Cellulose triacetate having an acetyl substitution degree of 2.94 100 parts by mass Methylene chloride (first solvent) 402 parts by mass Methanol (second solvent) 60 parts by mass (Preparation of matting agent solution)
20 parts by mass of silica particles having an average particle diameter of 16 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) and 80 parts by mass of methanol were mixed well for 30 minutes to obtain a silica particle dispersion.

  This dispersion was put into a disperser together with the following composition, and further stirred for 30 minutes or more to dissolve each component to prepare a matting agent solution.

Silica particle dispersion liquid having an average particle size of 16 nm 10.0 parts by mass Methylene chloride (first solvent) 76.3 parts by mass Methanol (second solvent) 3.4 parts by mass Cellulose acetate solution A 10.3 parts by mass (additive solution) Preparation)
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution.

The following optical anisotropy reducing agent 49.3 parts by mass The following wavelength dispersion adjusting agent 4.9 parts by mass Methylene chloride (first solvent) 58.4 parts by mass Methanol (second solvent) 8.7 parts by mass Cellulose triacetate Solution A 12.8 parts by mass

(Production of cellulose triacetate film)
94.6 parts by mass of the cellulose triacetate solution A, 1.3 parts by mass of the matting agent solution, and 4.1 parts by mass of the additive solution were mixed after filtration, and cast using a band casting machine.

  The mass ratio of the compound that reduces optical anisotropy and the wavelength dispersion adjusting agent to cellulose acetate in the above composition was 12% and 1.2%, respectively.

The film was peeled from the band with a residual solvent amount of 30% and dried at 140 ° C. for 40 minutes to produce a long cellulose acetate film T0 having a thickness of 80 μm. The in-plane retardation (Ro) of the obtained film was 1 nm (the slow axis was a direction perpendicular to the film longitudinal direction), and the thickness direction retardation (Rt) was −1 nm.
<Production of Polarizing Plate (P0)>
A roll-shaped polyvinyl alcohol film having a thickness of 80 μm continuously dyed in an aqueous iodine solution was stretched 5 times in the transport direction and dried to obtain a long polarizer.

The cellulose acetate film T0 saponified on one side of this polarizer and the commercially available cellulose triacetate film (Konica Minolta Tack KC4UY, manufactured by Konica Minolta Opto) on the other side were polyvinyl alcohol-based. A polarizing plate P0 was produced by continuously bonding using an adhesive.
Example 3
<Production of Liquid Crystal Display Devices (L1) to (L4)>
The liquid crystal cell was taken out from the liquid crystal television TH-32LX500 (manufactured by Matsushita Electric Industrial Co., Ltd.), and the polarizing plate and the optical film which were pasted on the viewer side and the backlight side were peeled off. In this liquid crystal cell, when no voltage was applied and during black display, the liquid crystal molecules were aligned substantially in parallel between the glass substrates, and the slow axis direction was horizontal to the screen.

  The produced polarizing plates (P1 and P0) were bonded to the upper and lower glass substrates of the parallel alignment cell using an adhesive. At this time, P1 is disposed on the polarizing plate on the backlight side, P0 is disposed on the viewer side, and the first optical anisotropic layer included in the polarizing plate P1 is in contact with the glass substrate on the backlight side. Moreover, it bonded together so that the cellulose acetate film T0 contained in polarizing plate P0 might contact the glass substrate by the side of a viewer.

  Further, the polarizer P1 and the liquid crystal cell were arranged so that the absorption axis of the polarizing plate P1 and the slow axis of the liquid crystal cell were orthogonal, and the absorption axes of the polarizing plate P1 and the polarizing plate P0 were orthogonal. The liquid crystal cell to which the polarizing plate was bonded in this way was again incorporated into the liquid crystal television TH-32LX500. In this way, a liquid crystal display device L1 was produced.

  The above polarizing plate P1 was changed to polarizing plates P2 to P4, respectively, to prepare liquid crystal display devices L2 to L4.

In the liquid crystal display devices L2 to L4, the liquid crystal cell, the first optical anisotropic layer, the second optical anisotropic layer, and the polarizing plate layer are in this order. The slow axis and the major axis direction of the liquid crystal molecules during black display were substantially parallel.
<Evaluation of liquid crystal display device>
(Durability evaluation against environmental changes)
The liquid crystal display device with the polarizing plate prepared above was conditioned for 50 hours in an environment of 23 ° C. and 10% RH, and then the luminance measurement of white display and black display was performed using EZ-Contrast 160D manufactured by ELDIM. The contrast (ratio of white luminance to black luminance) was calculated, and the angle of the contrast 200 in the 45 ° and 135 ° directions of the display device was used as the viewing angle. Similarly, the viewing angle was measured after humidity was adjusted for 50 hours in an environment of 23 ° C. and 90% RH. The results are shown in Table 3.
(Measurement method of front contrast and maximum contrast)
The liquid crystal display device shown below is created, and the brightness (Y value) of white and black is measured from the front direction using CS-2000 manufactured by Konica Minolta Sensing Co., Ltd. in a dark room, and the ratio thereof is calculated. White brightness / black brightness was defined as front contrast. Further, the maximum contrast direction was calculated using EZ-Contrast 160D manufactured by ELDIM, and the maximum contrast was obtained by measuring the white and black luminance at that angle.
(Evaluation method for uneven orientation)
<Phase difference unevenness>
A retardation film sample was subjected to retardation Ro measurement at 0.5 mm pitch at a measurement spot of 0.5 mm using a birefringence phase difference measuring device AD-175SI manufactured by Saitoh Co., Ltd. The measurement was performed by inclining 40 ° with the in-plane slow axis of the film as the tilt axis.

  In addition, before performing application | coating of a liquid-crystal layer, the phase difference nonuniformity of the cellulose-ester film was measured and it confirmed that there was no nonuniformity in less than 0.080 nm by 0.1 mm space | interval.

  The following was used as a reference for phase difference unevenness.

Interval Retardation difference Evaluation 0.1mm Less than 0.080nm ◎
0.1mm 0.080 or more and less than 0.110nm ○
0.1 mm 0.110 or more and less than 0.150 nm
0.1 mm 0.150 nm or more ×
<Heat unevenness>
Remove the polarizing plate of Matsushita Electric's 26-inch LCD TV, VIERA 26LX60 liquid crystal panel, and place the polarizing plate using the retardation film of the present invention on the liquid crystal panel viewing side, and the liquid crystal layer on the liquid crystal cell side. Pasted together.

  On the backlight side, a polarizing plate using an isotropic cellulose triacetate (TAC) film whose phase difference was adjusted to Ro = 0.8 nm and Rt = 1.1 nm was bonded.

  These configurations are shown in FIG. In the figure, what is described as a TAC film was Konica Minolta Tack KC4UY (manufactured by Konica Minolta Opto).

  The viewing-side polarizing plate was produced as follows. A saponified KC4UY was bonded to one surface of a polarizer obtained by adsorbing iodine to a stretched polyvinyl alcohol film using a polyvinyl alcohol-based adhesive. On the other surface, the retardation film of the present invention was bonded using a polyurethane-based adhesive to produce a viewing side polarizing plate.

  The backlight side polarizing plate saponified the cellulose ester film as usual, and bonded together using the polyvinyl alcohol-type adhesive agent, and produced the polarizing plate.

  The liquid crystal panel produced as described above was stored at 60 ° C. and 90% RH for 24 hours, the backlight was turned on to display black, and the intensity of unevenness was visually observed after 2 hours.

Situation Evaluation Strong unevenness at the four corners and cloudy unevenness on the entire surface ×
Strong unevenness occurs at the four corners △
Weak cloudy unevenness ○
No unevenness ◎

  In the liquid crystal display device of the present invention, a high contrast was obtained as compared with the liquid crystal display device of the comparative example, and the deterioration of the viewing angle when viewed from an oblique direction after storage at high temperature and high humidity was also small.

Claims (4)

It includes at least a first optical anisotropic layer and a second optical anisotropic layer, an in-plane retardation Ro of the first optical anisotropic layer is 0 to 10 nm, and a letter in the thickness direction Film thickness 20 containing a cellulose ester in which Rd is -400 to -80 nm and the second optically anisotropic layer is obtained by substituting a hydroxyl group of cellulose with an acetyl group and an acyl group having 3 to 5 carbon atoms. A cellulose ester film of ˜50 μm, wherein the substitution degree A of the acetyl group and the substitution degree B of the acyl group having 3 to 5 carbon atoms satisfy the following formulas (I) and (II): A retardation film having a retardation Ro of 20 to 150 nm and a thickness direction retardation Rt of 100 to 300 nm.
Formula (I): 2.0 ≦ A + B ≦ 3.0
Formula (II): 0 <B
Ro = (nx−ny) × d
Rt = ((nx + ny) / 2−nz) × d
It is.
Where nx is the refractive index in the slow axis direction in the plane of the optically anisotropic layer, ny is the refractive index in the direction perpendicular to the slow axis in the plane of the optically anisotropic layer, and nz is optical. (The refractive index in the thickness direction of the anisotropic layer, d represents the thickness (nm) of the optical anisotropic layer, and the measurement wavelength of the refractive index is 590 nm.)   The first optically anisotropic layer is composed of a composition containing a rod-like liquid crystal compound, and the molecules of the rod-like liquid crystal compound are substantially perpendicular to the layer plane in the first optically anisotropic layer. 2. The retardation film according to claim 1, wherein the retardation film is fixed in an aligned state, and the thickness direction retardation Rt of the layer in which the alignment of the rod-like liquid crystal compound is fixed is −400 to −80 nm. A retardation film.   A polarizing plate having both sides of a polarizer sandwiched between two polarizing plate protective films, wherein at least one of the polarizing plate protective films is the retardation film according to claim 1 or 2. .   A liquid crystal display device using the retardation film according to claim 1.