JP2007321108A - Polymer composition, retardation film, polarizing plate, liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer composition which can impart reverse wavelength dispersibility to films, and to provide a retardation film which can be produced in a simple production process and has such reverse wavelength dispersibility as that of broad band λ/four plates. <P>SOLUTION: This polymer composition is characterized by containing at least one polymer which contains one of connection groups of Figure (R is H, a 1 to 30C alkyl or a 3 to 30C cycloalkyl) in each repeating unit and a part having an absorption band of 300 nm<λmax<400 nm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a polymer composition that imparts reverse wavelength dispersibility to a film. The present invention also relates to a retardation plate having a birefringent reverse wavelength dispersion such as a broadband λ / 4 plate. Furthermore, the present invention relates to a polarizing plate and a liquid crystal display device using the retardation plate.

  A phase difference plate used for a liquid crystal display device is widely used for the purpose of improving a high contrast ratio and a color shift at a wide viewing angle in a color TFT liquid crystal display device or the like in various display modes. The types of retardation plates include a quarter wave plate (hereinafter abbreviated as “λ / 4 plate”) that converts linearly polarized light into circularly polarized light, and 1/2 that converts the polarization vibration plane of linearly polarized light by 90 °. There are wave plates (hereinafter abbreviated as “λ / 2 plates”). However, the conventional retardation plate can be adjusted to a phase difference of λ / 4 or λ / 2 of the light wavelength for monochromatic light, but is a composite wave in which light in the visible light range is mixed. For white light, there is a problem that a distribution occurs in the polarization state at each wavelength and the light is converted into colored polarized light. This originates in the material which comprises a phase difference plate having wavelength dispersion about a phase difference.

  In order to solve such problems, various broadband retardation plates capable of giving a uniform phase difference to light in a wide wavelength range have been studied. For example, a quarter-wave plate in which the phase difference of birefringent light is ¼ wavelength and a half-wave plate in which the phase difference of birefringent light is ½ wavelength have their optical axes intersected. A retardation plate bonded in a state is disclosed (for example, see Patent Document 1). Further, there is disclosed a retardation plate formed by laminating at least two retardation plates having an optical retardation value of 160 to 320 nm and the respective slow axes are not parallel or orthogonal to each other (for example, Patent Document 2).

  However, in order to produce the above-mentioned retardation plate, a complicated process of adjusting the optical orientation (optical axis and slow axis) of the two polymer films is required. The optical orientation of the polymer film generally corresponds to the longitudinal or lateral direction of the sheet or roll film. A polymer film having an optical axis or a slow axis in an oblique direction of a sheet or roll is difficult to produce industrially in large quantities. Furthermore, it is necessary to set the optical orientation of the two polymer films to an angle that is neither parallel nor orthogonal. Therefore, in order to manufacture these retardation films, it is necessary to manufacture a chip by cutting two kinds of polymer films at a predetermined angle and bonding the chips together. The chip bonding process and the like are complicated in operation, and are liable to cause quality deterioration due to axial misalignment, resulting in a low yield, an increase in cost, and deterioration due to contamination. In addition, it is difficult to strictly adjust the optical retardation value of the polymer film, and quality deterioration and the like are more likely to occur.

In order to solve such a problem, a method for producing a broadband λ / 4 plate with a single retardation plate without laminating retardation plates has been proposed (for example, see Patent Document 3).
This method is prepared by uniaxial stretching using a polymer film obtained by copolymerizing a monomer unit having a high refractive index anisotropy and a monomer unit having a negative birefringence. Since this stretched polymer film has reverse wavelength dispersion, it is possible to produce a broadband λ / 4 plate with a single retardation film and solve the above problems, but the obtained retardation Since the range of values is narrow, sufficient optical properties cannot be obtained unless a number of layers are laminated. As a result, the polarizing plate becomes thicker and heavier. In addition, it is necessary to prevent the occurrence of optical axis misalignment and foreign matter contamination in the process of laminating films, and there is a problem that the manufacturing is complicated.

  In Patent Document 4, a polymerizable liquid crystal compound is applied to the upper layer of the cellulose acylate film, dried and polymerized, and after removing the cured film, only the cellulose acylate film is stretched by 20% at 150 ° C. to reverse wavelength dispersion A film has been made. Even this method cannot solve the problem of complicated manufacturing.

JP-A-10-68816 JP-A-10-90521 International Publication No. 00/2675 Pamphlet JP 2005-242293 A

  In view of the above-mentioned problems, an object of the present invention is to provide a novel polymer composition and thereby a retardation plate having reverse wavelength dispersion such as a broadband λ / 4 plate that can be produced by a simple production process. It is to provide. Moreover, it is providing the polarizing plate and liquid crystal display device which used this phase difference plate.

  As a result of intensive studies to solve the above problems, the present inventors have found that the wavelength dispersion in the film can be reversed by adding a specific polymer composition to the specific film. It was. The present invention has been made based on such findings.

（ここで、Ｒは水素原子、炭素数１〜３０のアルキル基または炭素数３〜３０のシクロアルキル基を表す。）
［２］前記重合体が、該重合体の主鎖に対し略直交方向に３００ｎｍ＜λ_max＜４００ｎｍの吸収を有する部分を含むことを特徴とする［１］項に記載の高分子組成物。 The object of the present invention has been achieved by the following means.
[1] A polymer composition comprising a repeating unit containing at least one polymer containing any of the following linking groups and a moiety having an absorption of 300 nm <λ _max <400 nm.

(Here, R represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or a cycloalkyl group having 3 to 30 carbon atoms.)
[2] The polymer composition as described in the item [1], wherein the polymer includes a portion having an absorption of 300 nm <λ _max <400 nm in a direction substantially orthogonal to the main chain of the polymer.

（式中、Ａ₁およびＡ₂は−Ｏ−、−ＮＲ−（Ｒは水素原子または置換基）、−Ｓ−、−ＣＯ−からそれぞれ独立に選ばれる基を表し、Ｒ₁、Ｒ₂、Ｒ₃は置換基を表す。ｎは０から２までの整数を表す。Ｘは炭素数３〜３０の直鎖状、分枝状又は環状のアルキレン基を表す。Ｌ₁およびＬ₂はそれぞれ下記連結基のいずれかを表す。

（ここで、Ｒは水素原子、炭素数１〜３０のアルキル基または炭素数３〜３０のシクロアルキル基を表す。）） [3] The polymer composition as described in [1] or [2], wherein the polymer includes a repeating unit represented by the following general formula (I).

(Wherein, A ₁ and A ₂ each independently represent a group selected from —O—, —NR— (wherein R is a hydrogen atom or a substituent), —S—, —CO—, R ₁ , R ₂ , R ₃ represents a substituent, n represents an integer of 0 to 2. X represents a linear, branched or cyclic alkylene group having 3 to 30 carbon atoms, L ₁ and L ₂ are as follows. Represents any linking group.

(Here, R represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or a cycloalkyl group having 3 to 30 carbon atoms.)

（式中、Ａ₁およびＡ₂は−Ｏ−、−ＮＲ−（Ｒは水素原子または置換基）、−Ｓ−、−ＣＯ−からそれぞれ独立に選ばれる基を表し、Ｒ₁、Ｒ₂、Ｒ₃は置換基を表す。ｎは０から２までの整数を表す。Ｌ₁およびＬ₂はそれぞれ下記連結基のいずれかを表す。

（ここで、Ｒは水素原子、炭素数１〜３０のアルキル基または炭素数３〜３０のシクロアルキル基を表す。）） [4] The polymer composition according to any one of [1] to [3], wherein the polymer includes a repeating unit represented by the following general formula (II).

(Wherein, A ₁ and A ₂ each independently represent a group selected from —O—, —NR— (wherein R is a hydrogen atom or a substituent), —S—, —CO—, R ₁ , R ₂ , R ₃ represents a substituent, n represents an integer of 0 to 2. L ₁ and L ₂ each represent any of the following linking groups.

(Here, R represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or a cycloalkyl group having 3 to 30 carbon atoms.)

[5] The polymer composition according to any one of [1] to [4], comprising a cellulose compound.
[6] The polymer composition as described in the item [5], wherein the cellulose compound is cellulose acylate.
[7] A polymer film formed from the polymer composition according to any one of [1] to [6].
[8] In the film obtained by subjecting the polymer composition according to any one of [1] to [6] to orientation treatment such as stretching, birefringence Δn (550 nm) is positive with respect to the orientation direction. A birefringence Δn at a specific wavelength satisfies the following mathematical formulas (1) and (2).
Formula (1) 0.5 <Δn (450 nm) / Δn (550 nm) <1.0
Formula (2) 1.05 <Δn (630 nm) / Δn (550 nm) <1.5
[9] A polarizing plate comprising the retardation plate according to the item [8].
[10] A liquid crystal display device comprising the polarizing plate according to the item [9].

  The polymer composition of the present invention can impart reverse wavelength dispersibility to a film by adding it to a specific film. Further, the optical film of the present invention containing the polymer compound has reverse wavelength dispersion, and the retardation plate made of the optical film is useful as a λ / 4 plate, and can be preferably applied to a liquid crystal display device. it can.

  Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

[Polymer composition]
<Polymer>
In general, in a film obtained by subjecting a polymer composition to orientation treatment such as stretching, the birefringence Δn (550 nm) is positive with respect to the orientation direction, and the birefringence Δn at a specific wavelength is expressed by the following formula (1) 0.5 < Δn (450 nm) / Δn (550 nm) <1.0
Formula (2) 1.05 <Δn (630 nm) / Δn (550 nm) <1.5
In order to express the wavelength dispersion of Δn as described above, the absorption wavelength and the direction of the transition moment in the orientation direction (hereinafter referred to as TD direction) and the direction orthogonal thereto (hereinafter referred to as MD direction) are arranged well. There is a need. Here, they are blue (450 nm), green (550 nm), and red (630 nm), and it is necessary to match the optimum retardation at each wavelength in order to improve viewing angle characteristics.
In the present invention, when the positive birefringence is given to the most important green (550 nm), the preferable range of blue (450 nm) and red (630 nm) is the range of the above formulas (1) and (2). It is preferable that

Since Δn is a value obtained by subtracting the refractive index in the MD direction from the refractive index in the TD direction, the wavelength dispersion in the MD direction is more downward than the wavelength dispersion of the refractive index in the TD direction. If the side and the left are the short wavelength side), the subtracted value is
Formula (3): 1> | Δn (450 nm) / Δn (550 nm) |, and Formula (4): 1 <| Δn (630 nm) / Δn (550 nm) |
Satisfied. Since the wavelength dispersion of the refractive index is closely related to the absorption of the substance as represented by the Lorentz-Lorenz equation, in order to make the wavelength dispersion in the MD direction more downward, TD If the absorption transition wavelength in the MD direction can be made longer than that in the direction, a film satisfying equations (3) and (4) can be designed. For example, in a polymer material that has been stretched, the MD direction is perpendicular to the molecular chain. It is very difficult for a polymer material to lengthen the absorption transition wavelength in the polymer width direction. On the other hand, if the absorption transition wavelength of the “specific compound” is a long wave in the polymer width direction (MD direction) by adding and orienting the “specific compound” to the polymer material, the formulas (3) and (4) ) Can be designed.
If the refractive index of the “specific compound” is larger in the TD direction than in the MD direction, there is no problem that the birefringence Δn (550 nm) is positive with respect to the TD direction as a film. Even if the refractive index of the “specific compound” is larger in the MD direction than in the TD direction, there is no problem as long as the refractive index of the polymer material is large in the TD direction and the birefringence Δn (550 nm) as a film is positive.

Preferred "specific compound" for such a purpose, a polymer containing a partial and 300 nm <moiety having absorption lambda _max <400 nm with an absorption of lambda _max <300 nm in the repeating units and the like.
The measurement of λ _max of a specific portion of the polymer can be performed by measuring the maximum absorption wavelength of the monomer forming the polymer. When absorption is not observed in the wavelength region of 300 nm or more when the maximum absorption wavelength of the monomer is measured, the monomer has absorption at λ _max <300 nm. The method for measuring the maximum absorption wavelength is not particularly limited, and any apparatus can be used.

ここで、Ｒは水素原子、炭素数１〜３０のアルキル基（例えば、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｔｅｒｔ−ブチル基、ｎ−オクチル基、２−エチルヘキシル基）、または炭素数３〜３０のシクロアルキル基（例えば、シクロヘキシル基、シクロペンチル基）を表す。さらに好ましくは−Ｏ−、−ＣＯＯ−、−ＯＣＯ−である。 The portion having the absorption of λ _max <300 nm in the repeating unit of the polymer preferably includes the following linking groups.

Here, R is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms (for example, methyl group, ethyl group, n-propyl group, isopropyl group, tert-butyl group, n-octyl group, 2-ethylhexyl group), or A cycloalkyl group having 3 to 30 carbon atoms (for example, a cyclohexyl group or a cyclopentyl group) is represented. More preferred are -O-, -COO-, and -OCO-.

The polymer may be a homopolymer obtained by polymerizing one kind of monomer as long as the repeating unit includes a portion having an absorption of λ _max <300 nm and a portion having an absorption of 300 nm <λ _max <400 nm. Even a copolymer obtained by polymerizing two or more kinds of monomers may be used. In the present invention, it is preferable to use a lambda _max <300 nm monomer and 300nm <λ _max <copolymer obtained by polymerizing a monomer having an absorption of 400nm with absorption. The copolymer may be a block copolymer, a random copolymer or a graft copolymer, but is preferably a random copolymer.

The polymer preferably includes a portion having an absorption of 300 nm <λ _max <400 nm in a direction substantially orthogonal to the main chain. This is because when the polymer composition containing the polymer is formed into a film and stretched, the absorption transition wavelength in the direction orthogonal to the orientation direction in the film (MD direction), that is, the direction orthogonal to the molecular chain in the polymer is long wave. If so, it is possible to design a film satisfying the mathematical formulas (3) and (4).

  Furthermore, the polymer is preferably a polymer comprising a repeating unit represented by the following general formula (I).

（式中、Ａ₁およびＡ₂は各々独立に、−Ｏ−、−ＮＲ−（Ｒは水素原子または置換基を表す。）、−Ｓ−及び−ＣＯ−からなる群から選ばれる基を表し、Ｒ₁、Ｒ₂、Ｒ₃は各々独立に置換基を表す。ｎは０から２までの整数を表す。Ｘは炭素数３〜３０の直鎖状、分枝状又は環状のアルキレン基を表す。Ｌ₁およびＬ₂はそれぞれ下記連結基のいずれかを表す。

（ここで、Ｒは水素原子、炭素数１〜３０のアルキル基または炭素数３〜３０のシクロアルキル基を表す。））

(Wherein A ₁ and A ₂ each independently represents a group selected from the group consisting of —O—, —NR— (R represents a hydrogen atom or a substituent), —S— and —CO—. , R ₁ , R ₂ and R ₃ each independently represents a substituent, n represents an integer of 0 to 2, and X represents a linear, branched or cyclic alkylene group having 3 to 30 carbon atoms. L ₁ and L ₂ each represent any of the following linking groups.

(Here, R represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or a cycloalkyl group having 3 to 30 carbon atoms.)

A ₁ and A ₂ each independently represent a group selected from the group consisting of —O—, —NR— (wherein R is a hydrogen atom or a substituent), —S—, and —CO—. Preferred are —O—, —NR— (R represents a substituent, and examples include R ₁ described later) and —S—.

In the general formula (I), in the divalent linking group represented by L ₁ and L ₂ , R is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms (for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group). , Tert-butyl group, n-octyl group, 2-ethylhexyl group) or a cycloalkyl group having 3 to 30 carbon atoms (for example, cyclohexyl group, cyclopentyl group).
More preferred are -O-, -COO-, and -OCO-.

In general formula (I), R ₁ is a substituent, and when there are a plurality of R _{1 s} , they may be the same or different and may form a ring. The following can be applied as examples of the substituent.

  A halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an alkyl group (preferably an alkyl group having 1 to 30 carbon atoms, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a tert- Butyl group, n-octyl group, 2-ethylhexyl group), cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms such as cyclohexyl group, cyclopentyl group, 4-n-dodecylcyclohexyl) Group), a bicycloalkyl group (preferably a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms. Bicyclo [1,2,2] heptan-2-yl group, bicyclo [2,2,2] octane-3-yl group)

An alkenyl group (preferably a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, such as a vinyl group or an allyl group), a cycloalkenyl group (preferably a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, That is, it is a monovalent group in which one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms is removed, for example, a 2-cyclopenten-1-yl, 2-cyclohexen-1-yl group), a bicycloalkenyl group (substituted or substituted). An unsubstituted bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group in which one hydrogen atom of a bicycloalkene having one double bond is removed. A bicyclo [2,2,1] hept-2-en-1-yl group, a bicyclo [2,2,2] oct-2-en-4-yl group), Rukiniru group (preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, such as ethynyl group, propargyl group),

An aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, such as a phenyl group, a p-tolyl group, a naphthyl group), a heterocyclic group (preferably a 5- or 6-membered substituted or unsubstituted aromatic group A monovalent group obtained by removing one hydrogen atom from an aromatic or non-aromatic heterocyclic compound, and more preferably a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms. 2-furyl group, 2-thienyl group, 2-pyrimidinyl group, 2-benzothiazolyl group), cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group (preferably substituted or unsubstituted having 1 to 30 carbon atoms) Alkoxy groups such as methoxy, ethoxy, isopropoxy, tert-butoxy, n-octyloxy, 2-methoxyethoxy), aryloxy Si group (preferably a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms such as phenoxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradeca Noylaminophenoxy group),

A silyloxy group (preferably a silyloxy group having 3 to 20 carbon atoms, such as trimethylsilyloxy group or tert-butyldimethylsilyloxy group), a heterocyclic oxy group (preferably a substituted or unsubstituted heterocycle having 2 to 30 carbon atoms) Ring oxy group, 1-phenyltetrazole-5-oxy group, 2-tetrahydropyranyloxy group), acyloxy group (preferably formyloxy group, substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, carbon number 6-30 substituted or unsubstituted arylcarbonyloxy groups such as formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy group), carbamoyloxy group (preferably Or substitution of 1 to 30 carbon atoms Is an unsubstituted carbamoyloxy group, for example, N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di-n-octylaminocarbonyloxy group, Nn -Octylcarbamoyloxy group), alkoxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms, for example, methoxycarbonyloxy group, ethoxycarbonyloxy group, tert-butoxycarbonyloxy group, n- Octylcarbonyloxy group), aryloxycarbonyloxy group (preferably substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, such as phenoxycarbonyloxy group, p-methoxyphenoxycarbonyloxy group) , P-n-hexadecyloxycarbonyl phenoxycarbonyl group),

An amino group (preferably an amino group, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted anilino group having 6 to 30 carbon atoms, such as an amino group, a methylamino group, a dimethylamino group; , Anilino group, N-methyl-anilino group, diphenylamino group), acylamino group (preferably formylamino group, substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, substituted or unsubstituted 6 to 30 carbon atoms, or Unsubstituted arylcarbonylamino group, for example, formylamino group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group), aminocarbonylamino group (preferably substituted or unsubstituted amino acid having 1 to 30 carbon atoms) Carbonylamino group, for example, carbamoylamino group, N, N-dimethylamino Sulfonylamino group, N, N-diethylaminocarbonylamino group, morpholinocarbonylamino group), alkoxycarbonylamino group (preferably a substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms, such as methoxycarbonylamino group, ethoxycarbonyl) Amino group, tert-butoxycarbonylamino group, n-octadecyloxycarbonylamino group, N-methyl-methoxycarbonylamino group), aryloxycarbonylamino group (preferably substituted or unsubstituted aryloxy having 7 to 30 carbon atoms) Carbonylamino group, for example, phenoxycarbonylamino group, p-chlorophenoxycarbonylamino group, mn-octyloxyphenoxycarbonylamino group),

Sulfamoylamino group (preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms such as sulfamoylamino group, N, N-dimethylaminosulfonylamino group, Nn-octylamino Sulfonylamino groups), alkyl and arylsulfonylamino groups (preferably substituted or unsubstituted alkylsulfonylamino groups having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonylamino groups having 6 to 30 carbon atoms, such as methylsulfonyl An amino group, a butylsulfonylamino group, a phenylsulfonylamino group, a 2,3,5-trichlorophenylsulfonylamino group, a p-methylphenylsulfonylamino group, a mercapto group, and an alkylthio group (preferably a substituent having 1 to 30 carbon atoms) Or an unsubstituted alkylthio group such as Ruthio group, ethylthio group, n-hexadecylthio group), arylthio group (preferably a substituted or unsubstituted arylthio group having 6 to 30 carbon atoms, such as phenylthio group, p-chlorophenylthio group, m-methoxyphenylthio group), A heterocyclic thio group (preferably a substituted or unsubstituted heterocyclic thio group having 2 to 30 carbon atoms, for example, 2-benzothiazolylthio group, 1-phenyltetrazol-5-ylthio group),

Sulfamoyl group (preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms such as N-ethylsulfamoyl group, N- (3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group N-acetylsulfamoyl group, N-benzoylsulfamoyl group, N- (N′-phenylcarbamoyl) sulfamoyl group), sulfo group, alkyl and arylsulfinyl group (preferably having 1 to 30 carbon atoms substituted or Unsubstituted alkylsulfinyl group, substituted or unsubstituted arylsulfinyl group having 6 to 30 carbon atoms, such as methylsulfinyl group, ethylsulfinyl group, phenylsulfinyl group, p-methylphenylsulfinyl group), alkyl and arylsulfonyl groups ( Preferably, it has 1 to 3 carbon atoms A substituted or unsubstituted alkylsulfonyl group, a substituted or unsubstituted arylsulfonyl group having 6 to 30 carbon atoms, e.g., methylsulfonyl group, ethylsulfonyl group, phenylsulfonyl group, p- methylphenyl sulfonyl group),

An acyl group (preferably a formyl group, a substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, such as an acetyl group or a pivaloylbenzoyl group), Aryloxycarbonyl group (preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms, such as phenoxycarbonyl group, o-chlorophenoxycarbonyl group, m-nitrophenoxycarbonyl group, p-tert-butylphenoxy Carbonyl group), alkoxycarbonyl group (preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, tert-butoxycarbonyl group, n-octadecyloxycarbonyl group), carbamoyl Base Preferably, the substituted or unsubstituted carbamoyl group having 1 to 30 carbon atoms, for example, carbamoyl group, N-methylcarbamoyl group, N, N-dimethylcarbamoyl group, N, N-di-n-octylcarbamoyl group, N- (Methylsulfonyl) carbamoyl group),

Aryl and heterocyclic azo groups (preferably substituted or unsubstituted arylazo groups having 6 to 30 carbon atoms, substituted or unsubstituted heterocyclic azo groups having 3 to 30 carbon atoms, such as phenylazo group, p-chlorophenylazo group, 5-ethylthio-1,3,4-thiadiazol-2-ylazo group), imide group (preferably N-succinimide group, N-phthalimide group), phosphino group (preferably substituted or non-substituted having 2 to 30 carbon atoms) Substituted phosphino groups such as dimethylphosphino group, diphenylphosphino group, methylphenoxyphosphino group), phosphinyl groups (preferably substituted or unsubstituted phosphinyl groups having 2 to 30 carbon atoms such as phosphinyl group, dioctyl Oxyphosphinyl group, diethoxyphosphinyl group), phosphinyloxy group (preferred Or a substituted or unsubstituted phosphinyloxy group having 2 to 30 carbon atoms, such as a diphenoxyphosphinyloxy group or a dioctyloxyphosphinyloxy group, or a phosphinylamino group (preferably having a carbon number) 2-30 substituted or unsubstituted phosphinylamino groups such as dimethoxyphosphinylamino group, dimethylaminophosphinylamino group, silyl groups (preferably substituted or unsubstituted groups having 3 to 30 carbon atoms) Silyl group, for example, trimethylsilyl group, tert-butyldimethylsilyl group, phenyldimethylsilyl group).

  Among the above substituents, those having a hydrogen atom may be substituted with the above groups after removing this. Examples of such functional groups include an alkylcarbonylaminosulfonyl group, an arylcarbonylaminosulfonyl group, an alkylsulfonylaminocarbonyl group, and an arylsulfonylaminocarbonyl group. Examples thereof include a methylsulfonylaminocarbonyl group, a p-methylphenylsulfonylaminocarbonyl group, an acetylaminosulfonyl group, and a benzoylaminosulfonyl group.

R ₁ is preferably a chlorine atom, an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, a hydroxyl group, a carboxyl group, an alkoxy group, an aryloxy group, an acyloxy group, or an amino group, more preferably a chlorine atom or an alkyl group Group, aryl group, hydroxyl group and amino group.

R ₂ and R ₃ each independently represents a substituent. An example of R ₁ is given as an example. Preferably, it is preferred that substituent constant sigma _p value of Hammett is greater than zero electron withdrawing group, sigma _p value has an electron withdrawing substituent of 0 to 1.5 Further preferred. Examples of such a substituent include a trifluoromethyl group, a cyano group, a carbonyl group, and a nitro group. R ₂ and R ₃ may be bonded to form a ring.
Incidentally, sigma _p of Hammett's substituent constant, with respect to sigma _m, for example, Naoki Inamoto "Hammett Rule - Structure and Reactivity -" (Maruzen), and the synthesis of the Chemical Society of Japan ed., "Shin Jikken Kagaku Koza 14 Organic compound “Reaction V”, page 2605 (Maruzen), Tadao Nakatani, “Description of theoretical organic chemistry”, page 217 (Tokyo Kagaku Dojin), Chemical Review, 91, 165-195 (1991). .

In general formula (I), n represents an integer of 0 to 2, preferably 0 or 1.
In general formula (I), X represents a linear, branched or cyclic alkylene group having 3 to 30 (preferably 4 to 20) carbon atoms. Examples thereof include a propylene group, a butylene group, a 2-methylbutylene group, a 1,3-cyclobutylene group, a 1,4-cyclohexylene group, and a di-1,4-cyclohexylene group. In addition, the alkylene group referred to here may be that —CH ₂ — constituted may be substituted with —O—, —S—, —NR— (R is a hydrogen atom or an alkyl group), or —CO—. For example, the following structure is mentioned.

  The repeating unit represented by the general formula (I) is preferably a repeating unit represented by the following general formula (II).

（式中、Ａ₁およびＡ₂は−Ｏ−、−ＮＲ−（Ｒは水素原子または置換基）、−Ｓ−、−ＣＯ−からそれぞれ独立に選ばれる基を表し、Ｒ₁、Ｒ₂、Ｒ₃は置換基を表す。ｎは０から２までの整数を表す。Ｌ₁およびＬ₂はそれぞれ下記連結基のいずれかを表す。

（ここで、Ｒは水素原子、炭素数１〜３０のアルキル基または炭素数３〜３０のシクロアルキル基を表す。））
一般式（II）におけるＡ₁、Ａ₂、Ｌ₁、Ｌ₂、Ｒ₁、Ｒ₂、Ｒ₃、及びｎはそれぞれ、一般式（Ｉ）におけるＡ₁、Ａ₂、Ｌ₁、Ｌ₂、Ｒ₁、Ｒ₂、Ｒ₃、及びｎと同義であり、好ましい範囲も同様である。

(Wherein, A ₁ and A ₂ each independently represent a group selected from —O—, —NR— (wherein R is a hydrogen atom or a substituent), —S—, —CO—, R ₁ , R ₂ , R ₃ represents a substituent, n represents an integer of 0 to 2. L ₁ and L ₂ each represent any of the following linking groups.

(Here, R represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or a cycloalkyl group having 3 to 30 carbon atoms.)
In the general formula (II), A ₁ , A ₂ , L ₁ , L ₂ , R ₁ , R ₂ , R ₃ , and n are respectively A ₁ , A ₂ , L ₁ , L ₂ , _{R 1, R 2, R 3} , and have the same meanings as n, preferred ranges are also the same.

  Specific examples of the repeating unit represented by the general formula (I) or (II) are shown below, but the present invention is not limited thereto.

  The polymer contained in the polymer composition of the present invention may contain another repeating unit in consideration of solubility and the like in addition to the repeating unit represented by the general formula (I) or (II). There is no particular limitation. When the polymer contained in the polymer composition of the present invention contains another repeating unit, the ratio of the repeating unit represented by the general formula (I) or (II) to another repeating unit is 95: 5 to 5. It is preferably used in the range of 50:50, more preferably in the range of 90:10 to 75:25. Although the specific example of the said another repeating unit is shown below, this invention is not limited to these.

  The polymer contained in the polymer composition of the present invention can be obtained by a sequential polymerization reaction such as polycondensation or polyaddition, and the method is not limited. For example, the polycondensation method includes a melt polycondensation method using deacetic acid, a melt polycondensation method using dephenol, and a dehydrochloric acid homogeneous polycondensation performed in an organic solvent system in which an organic base is used as an acid chloride and a polymer is soluble. Any known method may be used, such as an interfacial polycondensation method in which a dicarboxylic acid compound is used as an acid chloride in a two-phase system of an alkaline aqueous solution and a water-immiscible organic solvent.

[Polymer composition]
The polymer contained in the above-described polymer composition of the present invention plays a role as a retardation control agent for optical films (particularly, a retardation increase and wavelength dispersion control agent). In particular, it plays a suitable role as a retardation control agent for obtaining a film excellent in Re expression by stretching and wavelength dispersion.
The polymer of the present invention may be used alone or in combination of a plurality of types to form a polymer composition. Further, the polymer of the present invention is a polymer composition containing a polymer not containing the repeating unit represented by the general formula (I) or (II) (hereinafter referred to as “another polymer”). In this case, a plurality of types may be used in combination.

  The degree of polymerization of the polymer is preferably in the range of 3 to 4000, although it depends on the molecular weight of the repeating unit. However, when a phase difference plate is used without using another polymer in combination, in view of physical properties such as strength of the obtained phase difference plate, a 100-4000 mer is preferable, a 150-3500 mer is more preferable, and a 200- A 3000-mer is more preferable. Moreover, when using another polymer together and making it a phase difference plate, when the compatibility etc. of polymers are considered, 3-300 mer is preferable, 3-250 mer is more preferable, 3-200 mer is more preferable. Is more preferable.

  The other polymer is not particularly limited as long as it is a commonly used polymer. For example, a polymer composition or a cellulose compound composed of ester, carbonate, olefin, acetylene, cycloolefin, norbornene, or the like can be mentioned, and a cellulose compound is preferable. The polymer composition preferably contains a cellulose compound as a main component. Here, “main component” means that the cellulose compound is contained in an amount of preferably 50% by mass or more, more preferably 75% by mass or more, based on the entire polymer composition.

  When the cellulose compound is used in combination, the content of the polymer containing the repeating unit represented by the general formula (I) or (II) of the present invention is 0.1 to 20 parts by mass with respect to the cellulose compound. It is preferably 0.1 to 16 parts by mass, more preferably 0.5 to 12 parts by mass, and most preferably 0.5 to 10 parts by mass.

  Another embodiment of the present invention is a film comprising the polymer composition. The polymer composition of the present invention may be a liquid (for example, a solution containing a cellulose compound) or a solid (for example, a film containing a cellulose compound as a main raw material), and has various forms. be able to.

  In the present invention, the “cellulose compound” is, for example, a compound having cellulose as a basic structure, and includes a compound having a cellulose skeleton obtained by introducing a functional group biologically or chemically using cellulose as a raw material. Say. The cellulose compound is preferably a cellulose ester, and more preferably cellulose acylate (such as cellulose triacylate and cellulose acylate propionate). In the present invention, two or more different cellulose compounds may be mixed and used.

  The cellulose compound used in the present invention will be described in detail. The cellulose compound used in the present invention is preferably cellulose acylate. Hereinafter, preferred embodiments of the present invention will be described by taking cellulose acylate as an example.

<Cellulose acylate raw material cotton>
Cellulose acylate raw material cellulose used in the present invention includes cotton linter and wood pulp (hardwood pulp, softwood pulp), etc., and any cellulose acylate obtained from any raw material cellulose can be used, optionally mixed. May be. Detailed descriptions of these raw material celluloses can be found in, for example, “Plastic Materials Course (17) Fibrous Resin” (by Marusawa / Uda, Nikkan Kogyo Shimbun, published in 1970) and JIII Journal of Technical Disclosure 2001-1745 ( 7 to 8) can be used, and the cellulose acylate film of the present invention is not particularly limited.

The specific cellulose acylate is a mixed fatty acid ester of cellulose obtained by substituting the hydroxyl group of cellulose with an acetyl group and an acyl group having 3 or more carbon atoms, and the degree of substitution of the cellulose with a hydroxyl group is as follows: It is preferable that the cellulose acylate satisfies Formula (5) and Formula (6).
Formula (5): 2.0 ≦ A + B ≦ 3.0
Formula (6): 0 <B
In the above formula, A represents the substitution degree of the acetyl group substituted by the hydroxyl group of cellulose, and B represents the substitution degree of the acyl group having 3 or more carbon atoms substituted by the hydroxyl group of cellulose.

  Glucose units having β-1,4 bonds constituting cellulose have free hydroxyl groups at the 2nd, 3rd and 6th positions. Cellulose acylate is a polymer obtained by esterifying some or all of these hydroxyl groups with acyl groups. 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).

<Degree of polymerization of cellulose acylate>
The degree of polymerization of the cellulose acylate in the present invention is preferably 180 to 700 in terms of viscosity average degree of polymerization. In the cellulose acetate, 180 to 550 is more preferable, 180 to 400 is more preferable, and 180 to 350 is particularly preferable. . By setting the degree of polymerization to 700 or less, the viscosity of the cellulose acylate dope solution does not become too high, and the film production by casting tends to be easy. Moreover, it is preferable that the polymerization degree is 180 or more because the strength of the produced film tends to be further improved. The average degree of polymerization can be measured by the intrinsic viscosity method of Uda et al. (Kazuo Uda, Hideo Saito, “Journal of the Textile Society”, Vol. 18, No. 1, pages 105-120, 1962). Specifically, it can be measured according to the method described in JP-A-9-95538.
Further, the molecular weight distribution of cellulose acylate preferably used in the present invention is evaluated by gel permeation chromatography, and its polydispersity index Mw / Mn (Mw is a weight average molecular weight, Mn is a number average molecular weight) is small, and the molecular weight distribution is Narrow is preferred. The specific value of Mw / Mn is preferably 1.0 to 3.0, more preferably 1.0 to 2.0, and further preferably 1.0 to 1.6. preferable.

When the low molecular component is removed, the average molecular weight (degree of polymerization) increases, but the viscosity becomes lower than that of normal cellulose acylate, which is useful. Cellulose acylate having a small amount of low molecular components can be obtained by removing low molecular components from cellulose acylate synthesized by a usual method. The removal of the low molecular component can be carried out by washing the cellulose acylate with an appropriate organic solvent. In addition, when manufacturing a cellulose acylate 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. When the amount of the sulfuric acid catalyst is within the above range, cellulose acylate that is preferable in terms of molecular weight distribution (uniform molecular weight distribution) can be synthesized. When used in the production of the cellulose acylate used in the present invention, the moisture content of the cellulose acylate is preferably 2% by mass or less, more preferably 1% by mass or less, and 0.7% by mass. More preferably, it is as follows. It is known that normal cellulose acylate contains water at a ratio of 2.5 to 5% by mass. In such a case, it is preferable to dry the cellulose acylate in order to obtain a preferable water content in the present invention. The drying method is not particularly limited as long as it can achieve the desired moisture content.
In addition, as the raw material cotton and the synthesis method of cellulose acylate in the present invention, for example, disclosed in the Japan Society for Invention and Innovation (Public Technical Number 2001-1745, pages 7 to 12, published on March 15, 2001, Invention Association). Those described can be preferably employed.

<Additives to cellulose acylate>
In addition to the polymer compound represented by the above general formula (I) or (II), the cellulose acylate solution includes various additives (for example, UV inhibitors, plasticizers, deterioration inhibitors, fine particles, optical property adjustment) Agents). Moreover, the addition time of the polymer compound represented by the general formula (I) or (II) and other additives may be added in any of the dope preparation steps, and the preparation step is performed at the end of the dope preparation step. These additives may be added as follows.

  These additives may be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, an ultraviolet absorber at 20 ° C. or lower and an ultraviolet absorber at 20 ° C. or higher can be mixed and used, and similarly, a plasticizer can be mixed and used. Specifically, the method described in JP 2001-151901 A can be employed.

(UV absorber)
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.

  Examples of the benzotriazole ultraviolet absorber include 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, 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 UV absorbers, 2-hydroxy-4-methoxybenzophenone, 2,2′-di-hydroxy-4,4′-methoxybenzophenone, 2- (2′-hydroxy-3′-tert-butyl), among others. -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 absorbent 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 above-described benzotriazole compounds, benzophenone compounds, and salicylic acid ester compounds. Among these, a benzotriazole-based compound is preferable because unnecessary coloring with respect to the cellulose ester is small.

  As for the UV absorber, JP-A-60-235852, JP-A-3-199201, JP-A-51907073, JP-A-5-194789, JP-A-5-271471, JP-A-6-107854, JP-A-6-107854. 118233, 6-148430, 7-11056, 7-11055, 7-11056, 8-29619, 8-239509, JP-A-2000-204173 These compounds can also be used.

  0.001-5 mass% is preferable with respect to a cellulose acylate, and, as for the addition amount of a ultraviolet absorber, 0.01-1 mass% is more preferable. If the addition amount is 0.001% by mass or more, the effect of addition can be sufficiently exerted, and if the addition amount is 5% by mass or less, it is preferable because bleeding out of the ultraviolet absorber to the film surface can be suppressed.

  Further, the ultraviolet absorber may be added simultaneously with dissolution of cellulose acylate, 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 spectral absorption characteristics can be easily adjusted.

(Deterioration inhibitor)
The deterioration inhibitor may be added to 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. A compound such as a UV absorber (JP-A-6-118233) can be used.

(Plasticizer)
The plasticizer is preferably a phosphate ester and / or a carboxylic acid ester. As the phosphate ester plasticizer, for example, triphenyl phosphate (TPP), tricresyl phosphate (TCP), cresyl diphenyl phosphate, octyl diphenyl phosphate, biphenyl diphenyl phosphate (BDP), trioctyl phosphate, tributyl phosphate and the like are preferable. . Examples of the carboxylate plasticizer include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP), diethyl hexyl phthalate (DEHP), O -Triethyl acetyl citrate (OACTE), tributyl O-acetyl citrate (OACTB), acetyl triethyl citrate, acetyl tributyl citrate, butyl oleate, methyl acetyl ricinoleate, dibutyl sebacate, triacetin, tributyrin, butyl phthalyl butyl Glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate and the like are preferable. Furthermore, the plasticizer is preferably (di) pentaerythritol esters, glycerol esters, diglycerol esters.

(Peeling accelerator)
Preferred examples of the peeling accelerator include citric acid ethyl esters.
(Infrared absorber)
As the infrared absorber, for example, those described in JP-A No. 2001-194522 are preferable.

(dye)
In the present invention, a dye for adjusting the hue may be added. The content of the dye is preferably 10 to 1000 ppm, more preferably 50 to 500 ppm in terms of a mass ratio with respect to cellulose acylate. By containing the dye in this way, light piping of the cellulose acylate film can be reduced, and yellowness can be improved. These compounds may be added together with cellulose acylate and a solvent during the preparation of the cellulose acylate solution, or may be added during or after the solution preparation. Moreover, you may add to the ultraviolet absorber liquid added in-line. The dyes described in JP-A-5-34858 can be used.

(Matting agent fine particles)
Fine particles may be added as a matting agent to the cellulose acylate 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, Mention may be made of magnesium silicate and calcium phosphate. As the fine particles, those containing silicon are more preferable in terms of low turbidity, and silicon dioxide is particularly preferable. The fine particles of silicon dioxide preferably have a primary average particle size 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.

  These fine particles usually form secondary particles having an average particle size of 0.1 to 3.0 μm, and these fine particles exist in the film as aggregates of primary particles, 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 0.2 μm to 1.5 μm, more preferably 0.4 μm to 1.2 μm, and most preferably 0.6 μm to 1.1 μm. For the primary / secondary particle size, the particles in the film were observed with a scanning electron microscope, and the diameter of the circle circumscribing the particles was defined as the particle size. In addition, 200 particles were observed at different locations, and the average value was taken as the average particle size.

  As the silicon dioxide fine particles, for example, commercially available products such as Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (all of which are trade names, manufactured by Nippon Aerosil Co., Ltd.) are used. be able to. Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (all of which are trade names, manufactured by Nippon Aerosil Co., Ltd.) and can be used.

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

In order to obtain a cellulose acylate film having particles having a small secondary average particle size in the present invention, several methods are conceivable when preparing a dispersion of fine particles. For example, a method of preparing a fine particle dispersion in which a solvent and fine particles are mixed with stirring in advance, adding this fine particle dispersion to a small amount of a separately prepared cellulose acylate solution, stirring and dissolving, and further mixing with the main cellulose acylate dope solution There is. 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, and use this as a fine particle additive solution. There is also a method of mixing. The present invention is not limited to these methods, but the concentration of silicon dioxide when the silicon dioxide fine particles are mixed and dispersed with a solvent or the like is preferably 5 to 30% by mass, more preferably 10 to 25% by mass, and 15 to 20%. More preferred is mass%. 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 acylate dope solution is preferably 0.01 to 1.0 g, more preferably 0.03 to 0.3 g, and 0.08 to 0.16 g per 1 m ^2. Most preferred.

  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.

(Compound addition ratio)
In the cellulose acylate film of the present invention, the total amount of compounds having a molecular weight of 3000 or less is preferably 5 to 45% by mass with respect to the mass of cellulose acylate. More preferably, it is 10-40 mass%, More preferably, it is 15-30 mass%. As described above, these compounds include compounds that reduce optical anisotropy, wavelength dispersion adjusters, ultraviolet inhibitors, plasticizers, deterioration inhibitors, fine particles, release agents, infrared absorbers, and the like. Furthermore, the total amount of compounds having a molecular weight of 2000 or less is more preferably within the above range. By setting the total amount of these compounds to 5% by mass or more, it becomes difficult for the properties of the cellulose acylate alone to appear, and for example, the optical performance and physical strength are less likely to fluctuate with changes in temperature and humidity. In addition, by setting the total amount of these compounds to 45% by mass or less, the limit of the compatibility of the compounds in the cellulose acylate film is exceeded, and the film is precipitated on the film surface and the cloudiness of the film (crying out from the film) is suppressed. It tends to be preferable

<Organic solvent of cellulose acylate solution>
In this invention, it is preferable to manufacture a cellulose acylate film by the solvent cast method, and it is preferable to manufacture using the solution (dope) which melt | dissolved the cellulose acylate in the organic solvent. The organic solvent preferably used as the main solvent in the present invention is preferably a solvent selected from esters, ketones, ethers having 3 to 12 carbon atoms, and halogenated hydrocarbons having 1 to 7 carbon atoms. Esters, ketones and ethers 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. It may have a functional group of 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.

  As described above, for the cellulose acylate film of the present invention, a chlorinated halogenated hydrocarbon may be used as a main solvent. For example, the disclosed technique (published technical report 2001-1745, pages 12-16, issued in 2001, invention. As described in the Association), a non-chlorine solvent may be used as the main solvent.

In addition, as the solvent for the cellulose acylate solution and the film, those disclosed in the following patent documents including the dissolution method can be mentioned as a preferred embodiment. JP 2000-95876 A, JP 12-95877 A, JP 10-324774 A, JP 8-152514 A, JP 10-330538 A, JP 9-95538 A, JP 9-95557 A, Special Kaihei 10-235664, JP-A-12-63534, JP-A-11-21379, JP-A-10-182853, JP-A-10-278056, JP-A-10-279702, JP-A-10-323853, JP-A-10-323853 JP-A-10-237186, JP-A-11-60807, JP-A-11-152342, JP-A-11-292988, JP-A-11-60752, and JP-A-11-60752.
According to these patent documents, not only the preferable solvent for the cellulose acylate of the present invention but also the solution physical properties and coexisting substances to be coexisted are described, and these are also preferable embodiments in the present invention.

<Manufacturing process of cellulose acylate film>
Next, a method for producing a film using a cellulose acylate solution will be described. As a method and equipment for producing the cellulose acylate film of the present invention, a solution casting film forming method and a solution casting film forming apparatus conventionally used for producing a cellulose triacetate film can be widely adopted.

(Dissolution process)
The method for dissolving the cellulose acylate solution (dope) is not particularly limited, and it may be performed at room temperature or further by a cooling dissolution method or a high temperature dissolution method, or a combination thereof. Regarding the preparation of the cellulose acylate solution in the present invention, and further the steps of solution concentration and filtration accompanying the dissolution step, JIII Journal of Technical Disclosure (Technical No. 2001-1745, pages 22-25, March 15, 2001) The manufacturing process described in detail in the Japanese publication, Invention Association) is preferably used.

  The dope transparency of the cellulose acylate solution in the present invention is preferably 85% or more, more preferably 88% or more, and further preferably 90% or more. In the present invention, it was confirmed that various additives were sufficiently dissolved in the cellulose acylate dope solution. As a specific method for calculating the dope transparency, the dope solution is injected into a 1 cm square glass cell, and the absorbance at 550 nm is measured with a spectrophotometer (UV-3150, trade name, Shimadzu Corporation). Only the solvent is measured in advance as a blank, and the transparency of the cellulose acylate solution is calculated from the ratio with the absorbance of the blank.

(Casting, drying, winding process)
The dope (cellulose acylate solution) prepared from the dissolving machine (kettle) is once 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 revolutions, and the dope is run endlessly from the die (slit) of the pressure die. The dope film (also referred to as web) is peeled from the metal support at the peeling point where the metal support is uniformly cast on the metal support, and the metal support has almost gone around. The both ends of the obtained web are sandwiched between clips, transported by a tenter while holding the width and dried, and then the obtained film is mechanically transported by a roll group of a drying device, dried, and then rolled by a winder Wind up to a predetermined length. 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 or the silver halide photographic light-sensitive material which is an optical member for electronic display, which is the main use of the cellulose acylate film of the present invention, the solution casting film forming apparatus In addition, a coating apparatus is often added for surface processing on films such as an undercoat layer, an antistatic layer, an antihalation layer, and a protective layer. These are described in detail in the Japan Institute of Invention Disclosure Technical Bulletin (Public Technical Number 2001-1745, pages 25-30, published on March 15, 2001, Japan Institute of Invention), and include casting (including co-casting). ), Metal support, drying, peeling, etc., and can be preferably used in the present invention.

(Extension process)
The cellulose acylate film preferably used in the present invention preferably has a retardation value adjusted by stretching. In particular, when the in-plane retardation value of the cellulose acylate film is set to a high value, a method of positively stretching in the width direction, for example, JP-A-62-115035, JP-A-4-152125, A method of stretching the produced film described in JP-A-4-284111, JP-A-4-298310, and JP-A-11-48271 can be used.

  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. The film is preferably stretched by 1 to 200%, more preferably stretched by 1 to 100%, and further preferably stretched by 1 to 50%.

  In order to suppress light leakage when the polarizing plate is viewed obliquely, it is necessary to arrange the transmission axis of the polarizing film and the in-plane slow axis of the cellulose acylate film in parallel. Since the transmission axis of the roll film-like polarizing film produced continuously is generally parallel to the width direction of the roll film, it is composed of the roll film-like polarizing film and the roll film-like cellulose acylate film. In order to continuously bond the protective film, the in-plane slow axis of the roll film-shaped protective film needs to be parallel to the width direction of the film. Therefore, it is preferable to stretch more in the width direction. The stretching process may be performed in the middle of the film forming process, or the original fabric that has been formed and wound may be stretched. In the former case, stretching may be performed in a state containing a residual solvent, and the stretching can be preferably performed at a residual solvent amount of 2 to 30% by mass.

  The thickness of the cellulose acylate film preferably used in the present invention obtained after drying varies depending on the purpose of use, is preferably in the range of 5 to 500 μm, more preferably in the range of 20 to 300 μm, and 30 to 30 μm. More preferably, it is in the range of 150 μm. Moreover, it is preferable that it is 40-110 micrometers for optical use, especially for VA liquid crystal display devices. The film thickness 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 so as to obtain a desired thickness.

  The width of the cellulose acylate 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, it is preferable to give knurling to at least one end, the knurling 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. is there. This may be a single push or a double push.

  The variation in the Re (590) value in the width direction of the film is preferably ± 5 nm, and more preferably ± 3 nm. Further, the variation in the Rth (590) value in the width direction is preferably ± 10 nm, and more preferably ± 5 nm. Moreover, it is preferable that the variation in the Re value and the Rth value in the length direction is also within the range of the variation in the width direction.

<Optical properties of cellulose acylate film>
(Measurement of Re and Rth)
In this specification, Re (λ) and Rth (λ) represent in-plane retardation and retardation in the thickness direction at a wavelength λ, respectively. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (both trade names, manufactured by Oji Scientific Instruments).
When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.
Rth (λ) is the wavelength from the direction inclined by + 40 ° with respect to the normal direction of the film, with Re (λ) and the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis). Retardation value measured by incidence of 590 nm light and in-plane slow axis as tilt axis (rotation axis) (if there is no slow axis, any direction in the film plane is the rotation axis) With respect to the normal direction of the film, light of wavelength λ nm is incident in 10 degree steps from the normal direction to 50 degrees on one side, and a total of 6 points are measured, and the measured retardation value and average It is calculated in KOBRA 21ADH or WR based on the assumed value of refractive index and the input film thickness value.
In the above case, in the case of a film having a direction in which the retardation value is zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, retardation at a tilt angle larger than the tilt angle. The value is calculated in KOBRA 21ADH or WR after changing its sign to negative.
In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (in the case where there is no slow axis, the arbitrary direction in the film plane is the rotation axis), Based on the value, the assumed value of the average refractive index, and the input film thickness value, Rth can also be calculated by the following equations (13) and (14).

  In formula (13), Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction. nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction perpendicular to nx in the plane, and nz represents the refractive index in the direction perpendicular to nx and ny.

In the case where the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optic axis, Rth (λ) is calculated by the following method.
Rth (λ) is from -50 ° to + 50 ° with respect to the film normal direction, with Re (λ) as the slow axis (indicated by KOBRA 21ADH or WR) in the plane and the tilt axis (rotation axis). In each of the 10 degree steps, light of wavelength λ nm is incident from each inclined direction and measured at 11 points. Based on the measured retardation value, the assumed average refractive index, and the input film thickness value, KOBRA 21ADH or Calculated in WR.
In the above measurement, as the assumed value of the average refractive index, the values of “Polymer Handbook” (JOHN WILEY & SONS, INC) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). By inputting the assumed value of the average refractive index and the film thickness, nx, ny, and nz are calculated in KOBRA 21ADH or WR. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

Re (λ) value and Rth (λ) value satisfy the following formulas (7) and (8), respectively, in order to widen the viewing angle of a liquid crystal display device, particularly a VA mode and OCB mode liquid crystal display device. Is preferable. In particular, a film (preferably a cellulose acylate film) is preferable when used as a protective film on the liquid crystal cell side of the polarizing plate.
Formula (7): 0 nm ≦ Re (590) ≦ 200 nm
Formula (8): 0 nm ≦ Rth (590) ≦ 400 nm
(In the formula, Re (590) and Rth (590) are values (unit: nm) at the wavelength λ = 590 nm.)
More preferably,
Formula (7-1): 30 nm ≦ Re (590) ≦ 150 nm
Formula (8-1): 30 nm ≦ Rth (590) ≦ 300 nm

When a film (preferably a cellulose acylate film) preferably used in the present invention is used for the VA mode and the OCB mode, a mode in which two sheets are used on both sides of the cell in total (two-sheet type), and the top and bottom of the cell There are two types of forms (single sheet type) that are used only on either side.
In the case of the two-sheet type, Re (590) is preferably 20 to 100 nm, and more preferably 30 to 70 nm. Rth (590) is preferably from 70 to 300 nm, more preferably from 100 to 200 nm.
In the case of a single sheet type, Re (590) is preferably 30 to 150 nm, and more preferably 40 to 100 nm. Rth (590) is preferably from 100 to 300 nm, more preferably from 150 to 250 nm.

<Water permeability of film>
The moisture permeability of a film (preferably a cellulose acylate film) used for the optical compensation sheet of the present invention is measured under conditions of a temperature of 60 ° C. and a humidity of 95% RH (relative humidity) based on JIS standard JIS Z 0208. The film thickness is preferably 400 to 2000 g / m ² · 24 h in terms of a film thickness of 80 μm. More preferably 500~1800g / m ² · 24h, and particularly preferably 600~1600g / m ² · 24h. By making it 2000 g / m ² · 24 h or less, the absolute value of the humidity dependence of the Re value and Rth value of the film is less likely to exceed 0.5 nm /% RH, which is preferable. Also, when an optically anisotropic film is formed by laminating an optically anisotropic layer on the film of the present invention (preferably a cellulose acylate film), the absolute value of humidity dependency of Re value and Rth value is 0.5 nm /%. It is difficult to exceed RH, which is preferable. When this optical compensation sheet or polarizing plate is incorporated in a liquid crystal display device, it causes a change in color and a decrease in viewing angle. In addition, when the moisture permeability of the film (preferably cellulose acylate film) is set to 400 g / m ² · 24 h or more, the film (preferably cellulose acylate film) is used when a polarizing plate is produced by sticking to both surfaces of the polarizing film. The rate film) makes it difficult for the adhesive to dry and poor adhesion.
If the film (preferably cellulose acylate film) is thick, the moisture permeability tends to be small, and if the film is thin, the moisture permeability tends to be large. Therefore, the moisture permeability in the present invention is described as a value obtained by converting the film thickness to 80 μm. Conversion of the film thickness is obtained as (water vapor permeability in terms of 80 μm = measured water vapor permeability × measured film thickness μm / 80 μm).
The measurement method for moisture permeability is “Polymer Physical Properties II” (Polymer Experiment Course 4, Kyoritsu Shuppan), pages 285 to 294: Measurement of vapor permeation (mass method, thermometer method, vapor pressure method, adsorption amount method) The film (preferably cellulose acylate film) sample 70 mmφ of the present invention is conditioned at 25 ° C. 90% RH and 60 ° C. 95% RH for 24 hours, respectively, and a moisture permeation test apparatus (KK-709007, trade name, Toyo Seiki Co., Ltd.) calculates the amount of water per unit area according to JIS Z-0208 (g / m ² ), and moisture permeability = mass after moisture conditioning−before moisture conditioning Calculate by mass.

<Residual solvent amount of film>
In this invention, it is preferable to dry on the conditions from which the amount of residual solvents with respect to a film (preferably cellulose acylate film) becomes the range of 0.01-1.5 mass%. More preferably, it is 0.01-1.0 mass%. When the film of the present invention (preferably a cellulose acylate film) is used as a support, curling can be further suppressed by setting the amount of residual solvent within this range. This is presumably because the main effect factor is that the free volume is reduced by reducing the amount of residual solvent at the time of film formation by the solvent casting method described above.

<Hygroscopic expansion coefficient of film>
The hygroscopic expansion coefficient of the film of the present invention (preferably a cellulose acylate film) is preferably 30 × 10 ⁻⁵ /% RH or less, more preferably 15 × 10 ⁻⁵ /% RH or less, and more preferably 10 ×. More preferably, it is 10 ⁻⁵ /% RH or less. The lower limit is not particularly defined, and the hygroscopic expansion coefficient tends to be preferably small, but more preferably 1.0 × 10 ⁻⁵ /% RH or more. The hygroscopic expansion coefficient indicates the amount of change in the length of the sample when the relative humidity is changed at a constant temperature. By adjusting the hygroscopic expansion coefficient, when the film of the present invention (preferably a cellulose acylate film) is used as an optical compensation film support, the frame-shaped transmittance is maintained while maintaining the optical compensation function of the optical compensation film. Light leakage due to the rise, that is, distortion can be prevented.

<Surface treatment>
The film (preferably cellulose acylate film) is optionally surface-treated to achieve improved adhesion between the film (preferably cellulose acylate film) and each functional layer (for example, the undercoat layer and the back layer). can do. For example, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment can be used. The glow discharge treatment here may be low-temperature plasma that occurs in a low-pressure gas of 10 ^{−3 to} 20 Torr (0.133 Pa to 2.67 kPa), and plasma treatment under atmospheric pressure is also preferable. A plasma-excitable gas is a gas that is plasma-excited under the above-mentioned conditions, and examples thereof include chlorofluorocarbons such as argon, helium, neon, krypton, xenon, nitrogen, carbon dioxide, tetrafluoromethane, and mixtures thereof. It is done. Details of these are described in detail in the Japan Institute of Invention Disclosure Technical Bulletin (Public Technical Number 2001-1745, pages 30 to 32, issued on March 15, 2001, Invention Association), and preferably used in the present invention. Can do.

(Alkaline saponification treatment)
The alkali saponification treatment is preferably carried out by a method in which a film (preferably a cellulose acylate film) is directly immersed in a tank of a saponification solution or a method in which a saponification solution is applied to a film (preferably a cellulose acylate film). Examples of the coating method include a dip coating method, a curtain coating method, an extrusion coating method, a bar coating method, and an E-type coating method. The solvent of the alkaline saponification treatment coating solution has good wettability in order to apply the saponification solution to the film (preferably a cellulose acylate film), and the saponification solution solvent causes the film (preferably the cellulose acylate film) to be coated on the surface. It is preferable to select a solvent that keeps the surface shape good without forming irregularities. Specifically, an alcohol solvent is preferable, and isopropyl alcohol is particularly preferable. An aqueous solution of a surfactant can also be used as a solvent. The alkali of the alkali saponification coating solution is preferably an alkali that dissolves in the above solvent, and more preferably KOH or NaOH. The pH of the saponification coating solution is preferably 10 or more, and more preferably 12 or more. The reaction conditions at the time of alkali saponification are preferably 1 second to 5 minutes at room temperature, more preferably 5 seconds to 5 minutes, and particularly preferably 20 seconds to 3 minutes. After the alkali saponification reaction, it is preferable to wash the surface on which the saponification solution is applied with water or with an acid and then with water.

<Functional layer>
The film of the present invention (preferably a cellulose film) is applied to optical uses and photographic photosensitive materials as its uses. In particular, the optical application is preferably a liquid crystal display device, and the liquid crystal display device has a liquid crystal cell in which liquid crystal is supported between two electrode substrates, two polarizing elements disposed on both sides thereof, and the liquid crystal It is more preferable that at least one optical compensation sheet is disposed between the cell and the polarizing element. These liquid crystal display devices include TN (Twisted Nematic), IPS (In-Plane Switching Crystal), FLLC (Ferroelectric Liquid Crystal), AFLC (Anti-Ferroelectric Liquid Crystal), OCB (Optical Liquid Crystal). ), ECB (Electrically Controlled Birefringence), VA (Vertically Aligned) and HAN (Hybrid Aligned Nematic).
In that case, when using the film (preferably cellulose film) of this invention for the above-mentioned optical use, providing various functional layers is implemented. These are, for example, an antistatic layer, a cured resin layer (transparent hard coat layer), an antireflection layer, an easy adhesion layer, an antiglare layer, an optical compensation layer, an alignment layer, a liquid crystal layer, and the like. These functional layers and materials for which the film of the present invention (preferably a cellulose film) can be used include surfactants, slip agents, matting agents, antistatic layers, hard coat layers, etc. It is described in detail in technical reports (public technical numbers 2001-1745, pages 32 to 45, published on March 15, 2001, Invention Association), and can be preferably used in the present invention.

[Polarizer]
The use of the film of the present invention (preferably a cellulose film) will be described.
The film of the present invention (preferably a cellulose film) is particularly useful as a polarizing plate protective film. When using as a polarizing plate protective film, the manufacturing method of a polarizing plate is not specifically limited, It can manufacture by a general method. There is a method in which the obtained film (preferably a cellulose film) is alkali-treated, and a polarizing film prepared by immersing and stretching a polyvinyl alcohol film in an iodine solution is bonded to both surfaces using a completely saponified polyvinyl alcohol aqueous solution. Instead of alkali treatment, easy adhesion processing as described in JP-A-6-94915 and JP-A-6-118232 may be performed.
Examples of the adhesive used to bond the protective film-treated surface and the polarizing film include polyvinyl alcohol adhesives such as polyvinyl alcohol and polyvinyl butyral, vinyl latexes such as butyl acrylate, and the like.
The polarizing plate is composed of a polarizing film and protective films that protect both surfaces thereof, and may further be configured by bonding a protective film on one surface of the polarizing plate and a separate film on the opposite surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection. In this case, the protect film is bonded for the purpose of protecting the surface of the polarizing plate, and is used on the side opposite to the surface where the polarizing plate is bonded to the liquid crystal plate. Moreover, a separate film is used in order to cover the adhesive layer bonded to a liquid crystal plate, and is used for the surface side which bonds a polarizing plate to a liquid crystal plate.
In a liquid crystal display device, a substrate containing liquid crystal is usually disposed between two polarizing plates, but a polarizing plate protective film to which the film of the present invention (preferably a cellulose film) is applied is excellent in any part. Displayability is obtained. In particular, the polarizing plate protective film on the display side outermost surface of the liquid crystal display device is provided with a transparent hard coat layer, an antiglare layer, an antireflection layer, and the like.

[Optical compensation film (retardation plate)]
The film of the present invention (preferably a cellulose film) can be used for various applications, and is particularly effective when used as an optical compensation film for a liquid crystal display device. The optical compensation film is generally used for a liquid crystal display device and refers to an optical material that compensates for a retardation, and is synonymous with a retardation plate, an optical compensation sheet, and the like. The optical compensation film has birefringence and is used for the purpose of removing the color of the display screen of the liquid crystal display device or improving the viewing angle characteristics.

[Liquid Crystal Display]
<Configuration of general liquid crystal display device>
When the film of the present invention (preferably a cellulose film) is used as an optical compensation film, the transmission axis of the polarizing film and the slow axis of the optical compensation film made of the film of the present invention (preferably a cellulose film) It may be arranged at an angle. The liquid crystal display device includes a liquid crystal cell having a liquid crystal supported between two electrode substrates, two polarizing films disposed on both sides thereof, and at least one sheet between the liquid crystal cell and the polarizing film. The optical compensation film is arranged.
The liquid crystal layer of the liquid crystal cell is usually formed by sealing liquid crystal in a space formed by sandwiching a spacer between two substrates. The transparent electrode layer is formed on the substrate as a transparent film containing a conductive substance. The liquid crystal cell may further be provided with a gas barrier layer, a hard coat layer, or an undercoat layer (undercoat layer) (used for adhesion of the transparent electrode layer). These layers are usually provided on the substrate. The substrate of the liquid crystal cell preferably has a thickness of 50 μm to 2 mm.

<Types of liquid crystal display devices>
The film of the present invention (preferably a cellulose film) can be used for liquid crystal cells in various display modes. Specifically, display modes such as TN, IPS, FLC, AFLC, OCB, STN, VA, ECB, and HAN are listed. The display mode can also be used in a display mode in which the orientation is divided. Further, the film of the present invention (preferably a cellulose film) can be preferably used in any of transmissive, reflective, and transflective liquid crystal display devices.

(TN type liquid crystal display device)
The film of the present invention (preferably a cellulose film) may be used as a support for an optical compensation sheet of a TN liquid crystal display device having a TN mode liquid crystal cell. TN mode liquid crystal cells and TN type liquid crystal display devices have been well known for a long time. The optical compensation sheet used in the TN type liquid crystal display device can be produced according to the descriptions in JP-A-3-9325, JP-A-6-148429, JP-A-8-50206, and JP-A-9-26572. it can. Also, Mori et al. (Jpn. J. Appl. Phys. Vol. 36, (1997), p. 143 and Jpn. J. Appl. Phys. Vol. 36, (1997), p. 1068). ).

(STN type liquid crystal display)
The film of the present invention (preferably a cellulose film) may be used as a support for an optical compensation sheet of an STN type liquid crystal display device having an STN mode liquid crystal cell. In general, in a STN type liquid crystal display device, rod-like liquid crystalline molecules in a liquid crystal cell are twisted in the range of 90 to 360 degrees, and the refractive index anisotropy (Δn) and cell gap (d) of the rod-like liquid crystalline molecules. Product (Δnd) is in the range of 300 to 1500 nm. The optical compensation sheet used in the STN type liquid crystal display device can be manufactured according to the description in JP-A-2000-105316.

(VA type liquid crystal display device)
The film of the present invention (preferably a cellulose film) is particularly advantageously used as a support for an optical compensation sheet of a VA liquid crystal display device having a VA mode liquid crystal cell. The Re value of the optical compensation sheet used in the VA liquid crystal display device is preferably 0 to 150 nm and the Rth value is preferably 70 to 400 nm. When two optically anisotropic polymer films are used for the VA liquid crystal display device, the Rth value of the film is preferably 70 to 250 nm. When one optically anisotropic polymer film is used for the VA liquid crystal display device, the Rth value of the film is preferably 150 to 400 nm. The VA-type liquid crystal display device may be an alignment-divided system as described in, for example, JP-A-10-123576.

(IPS liquid crystal display device and ECB liquid crystal display device)
The film of the present invention (preferably a cellulose film) is also advantageous as a support for an optical compensation sheet of an IPS liquid crystal display device and an ECB liquid crystal display device having liquid crystal cells of IPS mode and ECB mode, or as a protective film for a polarizing plate. Used for. In these modes, the liquid crystal material is aligned substantially in parallel during black display, and black is displayed by aligning liquid crystal molecules parallel to the substrate surface in the absence of voltage. In these embodiments, the polarizing plate using the film of the present invention (preferably a cellulose film) contributes to the improvement of the color tone, the expansion of the viewing angle, and the improvement of the contrast. In this embodiment, of the protective films of the polarizing plate above and below the liquid crystal cell, the protective film (protective film on the cell side) disposed between the liquid crystal cell and the polarizing plate is preferably a film of the present invention (preferably a cellulose film). ) Is preferably used on at least one side. More preferably, an optically anisotropic layer is disposed between the protective film of the polarizing plate and the liquid crystal cell, and the retardation value of the disposed optically anisotropic layer is not more than twice the value of Δn · d of the liquid crystal layer. It is preferable to set to.

(OCB type liquid crystal display device and HAN type liquid crystal display device)
The film of the present invention (preferably a cellulose film) is also advantageously used as a support for an optical compensation sheet of an OCB type liquid crystal display device having an OCB mode liquid crystal cell or a HAN type liquid crystal display device having a HAN mode liquid crystal cell. . In the optical compensation sheet used for the OCB type liquid crystal display device or the HAN type liquid crystal display device, it is preferable that the direction in which the absolute value of the retardation value is minimum does not exist in the plane of the optical compensation sheet or in the normal direction. The optical properties of the optical compensation sheet used in the OCB type liquid crystal display device or the HAN type liquid crystal display device are also the optical properties of the optically anisotropic layer, the optical properties of the support, and the optically anisotropic layer and the support. Is determined by the arrangement of An optical compensation sheet used for an OCB type liquid crystal display device or a HAN type liquid crystal display device can be produced according to the description in JP-A-9-197397. It can also be prepared according to the description of Mori et al. (Jpn. J. Appl. Phys. Vol. 38, (1999), p. 2837).

(Reflective liquid crystal display)
The film of the present invention (preferably a cellulose film) is also advantageously used as an optical compensation sheet for a reflective liquid crystal display device of TN type, STN type, HAN type, or GH (Guest-Host) type. These display modes have been well known since ancient times. The TN-type reflective liquid crystal display device can be manufactured according to the descriptions in JP-A-10-123478, International Publication WO98 / 48320, and Japanese Patent No. 3022477. The optical compensation sheet used in the reflective liquid crystal display device can be produced according to the description in International Publication WO00 / 65384.

(Other liquid crystal display devices)
The film of the present invention (preferably a cellulose film) is also advantageously used as a support for an optical compensation sheet of an ASM type liquid crystal display device having a liquid crystal cell of ASM (Axial Symmetrical Microcell) mode. The ASM mode liquid crystal cell is characterized in that the thickness of the cell is maintained by a resin spacer whose position can be adjusted. Other properties are the same as those of the TN mode liquid crystal cell. The ASM mode liquid crystal cell and the ASM type liquid crystal display device can be manufactured according to the description of Kume et al. (Kume et al., SID 98 Digest, (1998), p. 1089).

<Hard coat film, antiglare film, antireflection film>
The film of the present invention (preferably a cellulose film) can also be preferably used for a hard coat film, an antiglare film and an antireflection film. For the purpose of improving the visibility of flat panel displays such as LCD, PDP, CRT, EL, etc., any one of a hard coat layer, an antiglare layer and an antireflection layer is provided on one or both sides of the film of the present invention (preferably a cellulose film). Or all can be provided. A preferred embodiment of such an antiglare film or antireflection film is described in detail in JIII Journal of Technical Disclosure (Technology No. 2001-1745, pages 54 to 57, issued on March 15, 2001, Invention Association). The film of the present invention (preferably a cellulose film) can be preferably used.

<Photographic film support>
Furthermore, the film of the present invention (preferably a cellulose film) can be applied as a support for a silver halide photographic light-sensitive material. Specifically, the film of the present invention (preferably a cellulose film) is preferably used according to the description regarding color negative in JP-A-2000-105445. Further, application as a support for a color reversal silver halide photographic light-sensitive material is also preferable, and it can be produced according to various materials, formulations and processing methods described in JP-A No. 11-282119.

<Transparent substrate>
The film of the present invention (preferably a cellulose film) has optical anisotropy close to zero and can have excellent transparency. Therefore, the liquid crystal cell glass substrate of a liquid crystal display device is substituted, that is, a driving liquid crystal is enclosed. It can also be used as a transparent substrate.
Since the transparent substrate enclosing the liquid crystal needs to have excellent gas barrier properties, a gas barrier layer may be provided on the surface of the film of the present invention (preferably a cellulose film) as necessary. The form and material of the gas barrier layer are not particularly limited, but SiO ₂ or the like is vapor-deposited on at least one surface of the film of the present invention (preferably a cellulose film), or a relative gas barrier such as a vinylidene chloride polymer or a vinyl alcohol polymer. A method of providing a high polymer coating layer can be considered, and these can be used as appropriate.
In order to use as a transparent substrate for enclosing liquid crystal, a transparent electrode for driving the liquid crystal by applying a voltage may be provided. Although it does not specifically limit as a transparent electrode, A transparent electrode can be provided by laminating | stacking a metal film, a metal oxide film, etc. on the at least single side | surface of the film of this invention (preferably a cellulose film). Among these, a metal oxide film is preferable from the viewpoint of transparency, conductivity, and mechanical properties, and an indium oxide thin film containing mainly 2 to 15% by mass of tin oxide and zinc oxide can be preferably used. For details of these techniques, for example, methods described in JP-A Nos. 2001-125079 and 2000-227603 can be used.

  In order to control the Re value and the Rth value of the film of the present invention (preferably a cellulose film) within a preferable range, the polymer compound (retardation control agent) represented by the general formula (I) or (II) used is used. ) And the amount added, and the stretching ratio of the film is preferably adjusted as appropriate. In particular, in the present invention, a retardation control agent capable of achieving a desired Rth value is selected from the polymer compounds represented by the general formula (I) or (II), and a desired Re value is obtained. As described above, a film having a desired Re value and Rth value (preferably a cellulose film) can be obtained by appropriately setting the addition amount of the retardation control agent and the stretching ratio of the film.

  Hereinafter, the present invention will be described in more detail based on examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

Example 1
[Synthesis of Polymer (1)]
A polymer (1) was synthesized according to the following scheme.

Synthesis from compound (1-A) to compound (1-D) was performed by Journal of Chemical Crystallography (1997); 27 (9); 515-526. It carried out by the method of description.
20.7 g of compound (1-D), 2.0 g of p-sec-butylphenol, 1.8 g of tetrabutylammonium chloride, 200 ml of dichloromethane, 64 ml of 2 mol / L sodium hydroxide aqueous solution, 86 ml of water, equipped with a stirrer The reaction vessel was put into a reaction vessel and stirred at room temperature (25 ° C.) 300 rpm under a nitrogen stream. After 30 minutes, a solution of 11.2 g of adipic acid chloride dissolved in 100 ml of dichloromethane was added. Thereafter, stirring was continued for 3 hours, and then 100 mL of dichloromethane was added to separate the organic phase. Further, a solution obtained by diluting 0.52 ml of 12 mol / L hydrochloric acid water with 250 ml of water was added to wash the organic layer. After further washing with 250 ml of water twice, 100 ml of dichloromethane was added to the separated organic layer, diluted, and then poured into 2.5 liters of vigorously stirred methanol over 1 hour. The milky white precipitate obtained was collected by filtration in methanol, heat-dried at 40 ° C. for 12 hours, and then dried at 70 ° C. for 3 hours under reduced pressure to obtain 36.9 g of polymer (1).
As a result of measuring the molecular weight of the obtained polymer (1) with GPC (THF solvent), the weight average molecular weight was 10,900.
In addition, regarding the solution absorption of the compound (1-D), it is determined that λ _max : 338 nm and λ _max : 349 nm are Journal of Chemical Crystallography (1997); 27 (9); 515-526. It is described in. Adipic acid was also measured in the same manner as described in the above document, but no absorption was observed in the wavelength region exceeding 300 nm. This means that adipic acid has absorption in the wavelength range of λ _max <300 nm, as described herein.

Example 2
[Synthesis of Polymer (2)]
First, compound (2-B) was synthesized according to the following scheme. The synthesis from compound (2-A) to compound (2-B) was performed by a known method.

20.7 g of the compound (1-D) prepared in Example 1, 2.0 g of p-sec-butylphenol, 1.8 g of tetrabutylammonium chloride, 200 ml of dichloromethane, 64 ml of 2 mol / L sodium hydroxide aqueous solution, water 86 ml was put into a reaction vessel equipped with a stirrer, and stirred at room temperature (25 ° C.) 300 rpm under a nitrogen stream. After 30 minutes, a solution of 8.96 g of adipic acid chloride and 2.56 g of compound (2-B) in 110 ml of dichloromethane was added. Thereafter, stirring was continued for 3 hours, and then 100 mL of dichloromethane was added to separate the organic phase. Further, a solution obtained by diluting 0.52 ml of 12 mol / L hydrochloric acid water with 250 ml of water was added to wash the organic layer. After further washing with 250 ml of water twice, 100 ml of dichloromethane was added to the separated organic layer, diluted, and then poured into 2.5 liters of vigorously stirred methanol over 1 hour. The milky white precipitate obtained was collected by filtration in methanol, dried by heating at 40 ° C. for 12 hours, and then dried at 70 ° C. for 3 hours under reduced pressure to obtain 37.0 g of polymer (2) as a random copolymer.
As a result of measuring the molecular weight of the obtained polymer (2) with GPC (THF solvent), the weight average molecular weight was 10,500.
For Compound (2-A), Journal of Chemical Crystallography (1997); 27 (9); 515-526. As a result, the absorption was not observed in the wavelength region exceeding 300 nm. This means that the compound (2-A) has an absorption in the wavelength range of λ _max <300 nm, as described herein.

Example 3
[Production of cellulose acetate film]
Each component of the following cellulose acetate solution composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution.

(Cellulose acetate solution composition)
Cellulose acetate having an acetylation degree of 60.9% 100 parts by weight Triphenyl phosphate (plasticizer) 7.8 parts by weight Biphenyl diphenyl phosphate (plasticizer) 3.9 parts by weight Methylene chloride (first solvent) 318 parts by weight Methanol (No. 2 solvents) 47 parts by mass

In another mixing tank, the polymer (1), the polymer (2) or the comparative compound (1), 87 parts by mass of methylene chloride and 13 parts by mass of methanol are added and stirred while heating to form each retardation. A control agent solution was prepared.
36 parts by mass of the retardation control agent solution prepared above was mixed with 474 parts by mass of the cellulose acetate solution, and the dope was prepared by sufficiently stirring. In addition, each retardation control agent solution was added so that the quantity of a polymer (1), a polymer (2), or a comparison compound (1) might add the mass part of Table 1 with respect to 100 mass parts of cellulose acetate. Prepared.

The obtained dope was cast using a band casting machine. A cellulose acetate film (thickness: 92 μm) was produced by transversely stretching a film having a residual solvent amount of 15% by mass at a stretching ratio of 15% by free end uniaxial stretching at 150 ° C.
With respect to the produced cellulose acetate film, Re values at wavelengths of 450 nm, 550 nm, and 630 nm were measured using KOBRA 21ADH (trade name, manufactured by Oji Scientific Instruments) with light of each wavelength incident in the normal direction of the film. The results are shown in Table 1. In Table 1, No. 1 is a cellulose acetate film produced in the same manner except that no retardation control agent solution is added.

As is apparent from the results in Table 1, the sample No. which did not use the retardation control agent solution. No. 1 has an extremely low Re value, and it was found that the Re expression by stretching cannot be obtained. Moreover, it turned out that it does not satisfy | fill said Numerical formula (1) and (2), but is inferior to the wavelength dispersion of birefringence (DELTA) n. Sample No. to which the comparative compound (1) was added was used. No. 6 had a large Re value at each wavelength, but did not satisfy the above formulas (1) and (2), indicating that the wavelength dispersion of birefringence Δn was inferior.
In contrast, all of the samples of the present invention (sample Nos. 2 to 5) have a large Re value at each wavelength, satisfy the mathematical formulas (1) and (2), and have excellent wavelength dispersion of birefringence Δn. I understood it.

Sample No. to which comparative compound (1) was added 6 and the sample No. 1 to which the same amount of the polymer (1) or polymer (2) of the present invention as the comparative compound (1) was added. When comparing 3 and 5, the value of Re (550 nm) is not significantly different. 3 and 5 satisfy the above formulas (1) and (2), while sample nos. It turns out that 6 is not satisfied.
In addition, the sample No. in which the addition amount of the polymer of the present invention was changed was changed. Comparing 2 and 3 and 4 and 5, it can be seen that Re (550 nm) increases as the addition amount increases.

Example 4
(Preparation of polarizing plate)
A polarizing film was prepared by adsorbing iodine to a stretched polyvinyl alcohol film.
Cellulose acylate film No. 1 prepared in Example 3 above. 4 was affixed to one side of the polarizing film using a polyvinyl alcohol-based adhesive. The saponification treatment was performed under the following conditions.

A 1.5 mol / liter aqueous sodium hydroxide solution was prepared and kept at 55 ° C. A 0.01 mol / liter dilute sulfuric acid aqueous solution was prepared and kept at 35 ° C. The produced cellulose acylate film was immersed in the aqueous sodium hydroxide solution for 2 minutes, and then immersed in water to sufficiently wash away the aqueous sodium hydroxide solution. Subsequently, after being immersed in the above-mentioned dilute sulfuric acid aqueous solution for 1 minute, it was immersed in water to sufficiently wash away the dilute sulfuric acid aqueous solution. Finally, the sample was thoroughly dried at 120 ° C.
A commercially available cellulose triacylate film (Fujitac TD80UF, trade name, manufactured by Fuji Photo Film Co., Ltd.) is saponified and attached to the opposite side of the polarizer using a polyvinyl alcohol adhesive at 70 ° C. Dried for 10 minutes or more.
The transmission axis of the polarizing film and the slow axis of the cellulose acylate film produced as described above were arranged in parallel. The transmission axis of the polarizing film and the slow axis of the commercially available cellulose triacylate film were arranged so as to be orthogonal to each other.

(Production of liquid crystal cell)
The liquid crystal cell has a cell gap between substrates of 3.6 μm, and a liquid crystal material having negative dielectric anisotropy (“MLC6608”, trade name, manufactured by Merck & Co., Inc.) is dropped between the substrates and sealed. A liquid crystal layer was formed between them. The retardation of the liquid crystal layer (that is, the product Δn · d of the thickness d (μm) of the liquid crystal layer and the refractive index anisotropy Δn) was set to 300 nm. The liquid crystal material was aligned so as to be vertically aligned.

(Mounting on VA panel)
A commercially available super high contrast product (trade name, HLC2-5618, manufactured by Sanlitz Co., Ltd.) was used for the upper polarizing plate (observer side) of the liquid crystal display device using the vertical alignment type liquid crystal cell. On the lower polarizing plate (backlight side), cellulose acylate film No. 1 prepared in Example 3 was used. The polarizing plate provided with 4 was installed so that this cellulose acylate film might become the liquid crystal cell side. The upper polarizing plate and the lower polarizing plate were attached to the liquid crystal cell via an adhesive. The crossed Nicols were arranged so that the transmission axis of the upper polarizing plate was in the vertical direction and the transmission axis of the lower polarizing plate was in the left-right direction.

A rectangular wave voltage of 55 Hz was applied to the liquid crystal cell. A normally black mode with 5 V white display and 0 V black display was set. Black display at a black viewing azimuth angle of 45 degrees and a polar viewing angle of 60 degrees and a color shift between an azimuth angle of 45 degrees polar angle of 60 degrees and an azimuth angle of 180 degrees and a polar angle of 60 degrees were observed.
As a result of observing the produced liquid crystal display device, it was found that the liquid crystal panel using the film of the present invention can achieve a neutral black display in both the front direction and the viewing angle direction.

Claims (10)

A polymer composition comprising at least one polymer containing one of the following linking groups as a repeating unit and a moiety having an absorption of 300 nm <λ _max <400 nm.

(Here, R represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or a cycloalkyl group having 3 to 30 carbon atoms.) The polymer composition according to claim 1, wherein the polymer includes a portion having an absorption of 300 nm <λ _max <400 nm in a direction substantially perpendicular to the main chain of the polymer. The polymer composition according to claim 1 or 2, wherein the polymer comprises a repeating unit represented by the following general formula (I).

(Wherein, A ₁ and A ₂ each independently represent a group selected from —O—, —NR— (wherein R is a hydrogen atom or a substituent), —S—, —CO—, R ₁ , R ₂ , R ₃ represents a substituent, n represents an integer of 0 to 2. X represents a linear, branched or cyclic alkylene group having 3 to 30 carbon atoms, L ₁ and L ₂ are as follows. Represents any linking group.

(Here, R represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or a cycloalkyl group having 3 to 30 carbon atoms.) The polymer composition according to any one of claims 1 to 3, wherein the polymer comprises a repeating unit represented by the following general formula (II).

(Wherein, A ₁ and A ₂ each independently represent a group selected from —O—, —NR— (wherein R is a hydrogen atom or a substituent), —S—, —CO—, R ₁ , R ₂ , R ₃ represents a substituent, n represents an integer of 0 to 2. L ₁ and L ₂ each represent any of the following linking groups.

(Here, R represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or a cycloalkyl group having 3 to 30 carbon atoms.)   The polymer composition according to claim 1, comprising a cellulose compound.   6. The polymer composition according to claim 5, wherein the cellulose compound is cellulose acylate.   A polymer film formed from the polymer composition according to claim 1. In the film obtained by subjecting the polymer composition according to any one of claims 1 to 6 to an orientation treatment such as stretching, the birefringence Δn (550 nm) is positive with respect to the orientation direction and the compound at a specific wavelength. A phase difference plate having a refractive index Δn satisfying the following mathematical formulas (1) and (2).
Formula (1) 0.5 <Δn (450 nm) / Δn (550 nm) <1.0
Formula (2) 1.05 <Δn (630 nm) / Δn (550 nm) <1.5   A polarizing plate comprising the retardation plate according to claim 8. A liquid crystal display device comprising the polarizing plate according to claim 9.