JP4991170B2 - Optical resin film, polarizing plate, and liquid crystal display device - Google Patents

Description

  The present invention relates to an optical resin film, a polarizing plate using the same, and a liquid crystal display device.

  Liquid crystal display devices are increasingly used year by year as space-saving image display devices with low power consumption. Conventionally, the large viewing angle dependence of images has been a major drawback of liquid crystal display devices, but in recent years, the high viewing angle liquid crystal mode of the VA mode has been put into practical use, which enables high-quality images such as televisions to be displayed. In demanded markets, the demand for liquid crystal display devices is expanding rapidly. Accordingly, in the liquid crystal display device, further improvement in the optical compensation capability is required for the optical compensation member used for improving the color, contrast, and viewing angle dependency thereof.

As an optical compensation film for a VA mode liquid crystal display device, a combination of an A plate and a C plate is known to have a particularly high effect of improving the contrast viewing angle. Furthermore, Patent Document 1 discloses that optical compensation is performed with polymer films having different wavelength dispersions of in-plane retardation and thickness direction retardation, so that contrast is further improved with a single compensation film, and color in black display is improved. A technique for bringing the color closer to gray is disclosed. However, this method was insufficient in optimizing the retardation. Further, in Patent Document 2, in order to realize the above-mentioned wavelength dispersion characteristic, a stretched polymer film having a reverse wavelength dispersion characteristic in which the retardation becomes smaller as the wavelength becomes shorter becomes a forward wavelength in which the retardation becomes larger as the wavelength becomes shorter. A technique using a laminated retardation film in which coating layers having dispersion characteristics are laminated is disclosed. However, this method has a problem in terms of productivity and cost because the manufacturing process is complicated due to the laminated type.
WO2004 / 068226 A1 JP 2004-326089 A

  An object of the present invention is to provide an optical resin film in which the wavelength dispersion of in-plane retardation and the wavelength dispersion of thickness direction retardation are independently controlled. The object of the present invention is to provide an optical resin film having an in-plane retardation that is smaller on the shorter wavelength side (reverse wavelength dispersion) and a thickness direction retardation that is larger on the shorter wavelength side (forward wavelength dispersion). A further object of the present invention is to provide a liquid crystal display device having a wide viewing angle and a high display quality without causing problems such as color change by using a polarizing plate produced by using them in a liquid crystal display device. To do.

［式（１）のＡ ₁ 、Ａ ₂ 、Ａ ₃ 、Ａ ₅ はそれぞれ独立して、水素原子、炭素数１〜１０のアルキル基、アリール基、炭素数４〜１５のシクロアルキル基、ハロゲン原子である。また、Ａ ₁ 〜Ａ ₅ には、Ａ ₁ とＡ ₂ 、Ａ ₁ とＡ ₃ またはＡ ₂ とＡ ₅ から形成されるアルキレン基も含まれる。ｒは０〜２の整数を示す。

［式（３）中、Ｂ ₁ 〜Ｂ ₄ はそれぞれ独立して、水素原子、アルキル基、シクロアルキル基、アリール基、ハロゲン化アルキル基、加水分解性シリル基または−（ＣＨ ₂ ）jＸで表される極性基を示し、Ｂ ₁ 〜Ｂ ₄ の少なくとも一つは加水分解性シリル基または−（ＣＨ ₂ ）jＸで表される極性基を含む。ここで、Ｘは−Ｃ（Ｏ）ＯＲ ¹ または−ＯＣ（Ｏ）Ｒ ² であり、Ｒ ¹ 、Ｒ ² は炭素数１〜１０のアルキル基、アルケニル基、シクロアルキル基、アリール基、またはこれらのハロゲン置換体からなる基から選ばれた置換基、ｊは０〜３の整数である。また、Ｂ ₁ 〜Ｂ ₄ には、Ｂ ₁ とＢ ₃ またはＢ ₂ とＢ ₄ から形成されるアルキレン基、Ｂ ₁ とＢ ₂ またはＢ ₃ とＢ ₄ から形成されるアルキリデニル基も含まれる。ｒは０〜２の整数を示す。
〔４〕
前記スチレン及び／もしくはスチレン誘導体と他のモノマーとの共重合体が、スチレン及び／もしくはスチレン誘導体と、アクリルニトリル、無水マレイン酸、メチルメタクリレートおよびブタジエンから選ばれる少なくとも一種との共重合体である、〔１〕〜〔３〕のいずれかに記載の延伸光学樹脂フィルム。
〔５〕
該添加剤が２００ｎｍ以上４００ｎｍ以下の波長領域に吸収極大を有することを特徴とする〔１〕〜〔４〕のいずれかに記載の延伸光学樹脂フィルム。
〔６〕
該延伸光学樹脂フィルムの遅相軸と延伸方向の成す角度が−５°以上５°以下であり、かつ長手方向における前記角度の変動幅が５°以下である〔１〕〜〔５〕のいずれかに記載の延伸光学樹脂フィルム。
〔７〕
光学樹脂フィルムの膜厚が４０〜１１０μｍである〔１〕〜〔６〕のいずれかに記載の延伸光学樹脂フィルム。
〔８〕
負の固有複屈折性を有する添加剤を光学樹脂フィルムに添加し、該フィルムを延伸することを特徴とする〔１〕〜〔７〕のいずれかに記載の延伸光学樹脂フィルムの製造方法。
〔９〕
偏光子の両側に保護フィルムが貼り合わされてなる偏光板であって、該保護フィルムの少なくとも１枚が〔１〕〜〔７〕のいずれかに記載の延伸光学樹脂フィルムであることを特徴とする偏光板。
〔１０〕
液晶セルおよびその両側に配置された二枚の偏光板からなる液晶表示装置であって、少なくとも１枚の偏光板が〔９〕に記載の偏光板であることを特徴とする液晶表示装置。
〔１１〕
液晶モードがＯＣＢまたはＶＡモードである〔１０〕に記載の液晶表示装置。
〔１２〕
〔９〕に記載の偏光板をセルのバックライト側に用いたことを特徴とするＶＡモード液晶表示装置。
本発明は、上記〔１〕〜〔１２〕に係る発明であるが、以下、それ以外の事項（例えば、下記１）〜１１））についても記載している。
１）高分子樹脂と、該高分子樹脂１００質量部に対する含有量が０．１〜２０質量部の負の固有複屈折性を有する添加剤の少なくとも１種とを含有し、レターデーションが下記（Ａ）〜（Ｆ）の関係を満たし、より好ましくは下記（Ａ１）〜（Ｆ１）を満たし、さらに好ましくは下記（Ａ２）〜（Ｆ２）を満たすことを特徴とする延伸光学樹脂フィルム。
０ｎｍ＜Ｒｅ（５４６）＜３００ｎｍ （Ａ）
３０ｎｍ＜Ｒｔｈ（５４６）＜７００ｎｍ （Ｂ）
０．１＜Ｒｅ（４８０）／Ｒｅ（５４６）＜１．０ （Ｃ）
１．０＜Ｒｅ（６２８）／Ｒｅ（５４６）＜４．０ （Ｄ）
０．８＜Ｒｔｈ（４８０）／Ｒｔｈ（５４６）＜４．０ （Ｅ）
０．１＜Ｒｔｈ（６２８）／Ｒｔｈ（５４６）＜１．２ （Ｆ） As a result of intensive studies, the present inventors have found that the above problems can be achieved by the following means.
[1]
Contains a polymer resin which is a cellulose acylate or cycloolefin polymer, and at least one additive having a negative intrinsic birefringence of 0.1 to 20 parts by mass with respect to 100 parts by mass of the polymer resin The retardation is a stretched optical resin film satisfying the following relationships (A) to (F), and the additive is a copolymer of styrene and / or a styrene derivative and another monomer, or polystyrene: A stretched optical resin film.
0 nm <Re (546) <300 nm (A)
30 nm <Rth (546) <700 nm (B)
0.1 <Re (480) / Re (546) <1.0 (C)
1.0 <Re (628) / Re (546) <4.0 (D)
0.8 <Rth (480) / Rth (546) <4.0 (E)
0.1 <Rth (628) / Rth (546) <1.2 (F)
[2]
The stretched optical resin film according to [1], wherein the acylate of the cellulose acylate is an alkyl carbonyl ester, an alkenyl carbonyl ester, an aromatic carbonyl ester or an aromatic alkyl carbonyl ester.
[3]
In [1], the cycloolefin polymer is a cycloolefin addition polymer including a structural unit (a) represented by the following general formula (1) and a structural unit (b) represented by the following general formula (3). The stretched optical resin film described.

[A ₁ , A ₂ , A ₃ and A _{5 in} Formula (1) are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group, a cycloalkyl group having 4 to 15 carbon atoms, or a halogen atom. It is. A _{1 to} A ₅ also include an alkylene group formed from A ₁ and A ₂ , A ₁ and A _3, or A ₂ and A ₅ . r represents an integer of 0-2.

[In formula (3), B _{1 to} B ₄ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, a halogenated alkyl group, a hydrolyzable silyl group, or — (CH ₂ ) jX. And at least one of B _{1 to} B ₄ includes a hydrolyzable silyl group or a polar group represented by — (CH ₂ ) jX. Here, X is —C (O) OR ¹ or —OC (O) R ² , and R ¹ and R ² are each an alkyl group having 1 to 10 carbon atoms, an alkenyl group, a cycloalkyl group, an aryl group, or these A substituent selected from the group consisting of halogen substituents, j is an integer of 0-3. B _{1 to} B ₄ also include an alkylene group formed from B ₁ and B ₃ or B ₂ and B ₄ , and an alkylidenyl group formed from B ₁ and B ₂ or B ₃ and B ₄ . r represents an integer of 0-2.
[4]
The copolymer of styrene and / or a styrene derivative and another monomer is a copolymer of styrene and / or a styrene derivative and at least one selected from acrylonitrile, maleic anhydride, methyl methacrylate, and butadiene. The stretched optical resin film according to any one of [1] to [3].
[5]
The stretched optical resin film according to any one of [1] to [4], wherein the additive has an absorption maximum in a wavelength region of 200 nm to 400 nm.
[6]
Any of [1] to [5], wherein an angle formed between the slow axis of the stretched optical resin film and the stretch direction is -5 ° or more and 5 ° or less, and a fluctuation range of the angle in the longitudinal direction is 5 ° or less. A stretched optical resin film according to claim 1.
[7]
The stretched optical resin film according to any one of [1] to [6], wherein the film thickness of the optical resin film is 40 to 110 μm.
[8]
The method for producing a stretched optical resin film according to any one of [1] to [7], wherein an additive having negative intrinsic birefringence is added to the optical resin film, and the film is stretched.
[9]
A polarizing plate having a protective film bonded to both sides of a polarizer, wherein at least one of the protective films is the stretched optical resin film according to any one of [1] to [7]. Polarizer.
[10]
A liquid crystal display device comprising a liquid crystal cell and two polarizing plates arranged on both sides thereof, wherein at least one polarizing plate is the polarizing plate described in [9].
[11]
The liquid crystal display device according to [10], wherein the liquid crystal mode is OCB or VA mode.
[12]
[9] A VA mode liquid crystal display device using the polarizing plate according to [9] on the backlight side of the cell.
The present invention relates to the above [1] to [12], but hereinafter, other matters (for example, the following 1) to 11)) are also described.
1) A polymer resin and at least one additive having a negative intrinsic birefringence of 0.1 to 20 parts by mass with respect to 100 parts by mass of the polymer resin, and the retardation is as follows ( A stretched optical resin film that satisfies the relationships A) to (F), more preferably satisfies the following (A1) to (F1), and more preferably satisfies the following (A2) to (F2).
0 nm <Re (546) <300 nm (A)
30 nm <Rth (546) <700 nm (B)
0.1 <Re (480) / Re (546) <1.0 (C)
1.0 <Re (628) / Re (546) <4.0 (D)
0.8 <Rth (480) / Rth (546) <4.0 (E)
0.1 <Rth (628) / Rth (546) <1.2 (F)

20 nm <Re (546) <200 nm (A1)
70 nm <Rth (546) <500 nm (B1)
0.3 <Re (480) / Re (546) <1.0 (C1)
1.0 <Re (628) / Re (546) <3.0 (D1)
1.0 <Rth (480) / Rth (546) <3.0 (E1)
0.3 <Rth (628) / Rth (546) <1.0 (F1)

30 nm <Re (546) <150 nm (A2)
100 nm <Rth (546) <400 nm (B2)
0.5 <Re (480) / Re (546) <1.0 (C3)
1.0 <Re (628) / Re (546) <2.0 (D3)
1.0 <Rth (480) / Rth (546) <2.0 (E3)
0.5 <Rth (628) / Rth (546) <1.0 (F3)

2) the polymer resin is a cell Rurosuashire DOO, stretched optical resin film of the support serial to 1).

3) the polymer resin is a cyclo olefin polymer over, stretched optical resin film according to 1).
4) The stretched optical resin film according to any one of 1) to 3), wherein the additive has an absorption maximum in a wavelength region of 200 nm to 400 nm.
5) The angle formed between the slow axis of the stretched optical resin film and the stretch direction is -5 ° or more and 5 ° or less, and the fluctuation range of the angle in the longitudinal direction is 5 ° or less. A stretched optical resin film according to claim 1.
6) The stretched optical resin film according to any one of 1) to 5), wherein the optical resin film has a thickness of 40 to 110 μm.

7) The method for producing a stretched optical resin film according to any one of 1) to 6), wherein an additive having negative intrinsic birefringence is added to the optical resin film, and the film is stretched.
8) A polarizing plate in which a protective film is bonded to both sides of a polarizer, and at least one of the protective films is a stretched optical resin film according to any one of 1) to 7). Board.
9) A liquid crystal display device comprising a liquid crystal cell and two polarizing plates disposed on both sides thereof, wherein at least one polarizing plate is the polarizing plate described in 8).
10) The liquid crystal display device according to 9), wherein the liquid crystal mode is OCB or VA mode.
11) A VA mode liquid crystal display device using the polarizing plate according to 10) on a backlight side of a cell.

  In the present invention, an optical resin film having in-plane retardation of reverse wavelength dispersion and thickness direction retardation of forward wavelength dispersion is particularly preferable.

  The optical resin film having the optical properties of the present invention can be obtained by adding an additive having negative intrinsic birefringence to the optical resin and stretching it. Preferably, an optical resin having a characteristic that the wavelength dispersion characteristic in the visible light region of in-plane retardation is substantially flat or reverse dispersion is used.

  That is, when a negative intrinsic birefringent additive is added to the stretched optical resin as a matrix, the additive maximizes the orientation direction of the polymer main chain of the optical resin and the polarizability anisotropy of the additive. The orientation direction of the in-plane retardation of the optical resin and the additive is almost orthogonal because the orientation is oriented so that the directions are almost orthogonal, and the in-plane retardation of the optical resin is the in-plane retardation of the additive. Only the value is canceled out, and the specific retardation value of the present invention can be obtained. The stretched optical resin is more preferable when the wavelength dispersion characteristic in the visible light region of in-plane retardation and thickness direction retardation is substantially flat or reverse dispersion. Since the wavelength dispersion characteristic of the additive is forward dispersion, as a result, the wavelength dispersion characteristic of the in-plane retardation of the stretched optical film is reversed when the wavelength dispersion characteristic of the in-plane retardation of the optical resin is flat. When the dispersion is inverse dispersion, the dispersion has a larger inverse dispersion characteristic. On the other hand, in the thickness direction retardation, both the optical resin and the additive are aligned in the plane, and the direction in which the polarizability anisotropy is maximum is also aligned in the plane. On the contrary, it will strengthen each other. If the additive has a forward dispersion characteristic that exceeds the wavelength dispersion characteristic that is flat or reverse dispersion of the optical resin, as a result, the thickness direction retardation of the stretched optical film has a forward dispersion characteristic. .

ADVANTAGE OF THE INVENTION According to this invention, the optical resin film and polarizing plate which controlled the wavelength dispersion of in-plane retardation and the wavelength dispersion of thickness direction retardation independently can be provided. In particular, it is possible to produce an optical resin film and a polarizing plate in which in-plane retardation is reverse wavelength dispersion and thickness direction retardation is forward wavelength dispersion.
According to the present invention, an optical resin film can be produced by casting a polymer solution and stretching a film without performing coating, and it can be produced more simply and at a lower cost than the conventional technique for coating. it can.

  Such a polarizing plate having an optical compensation function can be used particularly advantageously in VA (vertically aligned) type and OCB (optically compensated bend) type liquid crystal display devices, and has a wide contrast viewing angle and color viewing angle. A display device is obtained.

[Optical resin]
First, the stretched optical resin used in the present invention will be described in detail.
Examples of the stretched optical resin of the present invention include various transparent polymer resins, and are not particularly limited. Examples include polycarbonate, polyester, polyvinyl chloride, cellulose acylate, and cycloolefin polymer. Among them, it is preferable to use a retardation having a wavelength dispersion characteristic that is substantially flat in the visible light region or having a reverse wavelength dispersion characteristic. More preferably, a polymer is used. It is particularly preferable to use cellulose acetate as the cellulose acylate.

(Cellulose acylate)
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). The total acyl substitution degree, that is, D2 + D3 + D6 is preferably 2.00 to 2.96, more preferably 2.22 to 2.95, and particularly preferably 2.40 to 2.94. These cellulose acylate films can produce a solution having a preferable solubility, and in particular, a non-chlorine organic solvent can produce a good solution. Furthermore, it becomes possible to produce a solution having a low viscosity and good filterability.

  The substituent for the hydroxyl group of cellulose is preferably an acetyl group. Further, the acyl group having 2 or more carbon atoms substituted on the hydroxyl group of cellulose may be an aliphatic group or an aryl group, and is not particularly limited. These are, for example, cellulose alkylcarbonyl esters, alkenylcarbonyl esters, aromatic carbonyl esters, aromatic alkylcarbonyl esters, and the like, each of which may further have a substituted group. These preferred substituents include propionyl, butanoyl, keptanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, iso-butanoyl, t-butanoyl, cyclohexanecarbonyl, oleoyl, Examples include benzoyl, naphthylcarbonyl, cinnamoyl groups and the like. Among these, propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, oleoyl, benzoyl, naphthylcarbonyl, cinnamoyl and the like are more preferable. Particularly preferred are propionyl and butanoyl.

(Method for synthesizing cellulose acylate)
The basic principle of the cellulose acylate synthesis method is described in Nobuhiko Umeda et al., Wood Chemistry pages 180-190 (Kyoritsu Shuppan, 1968). A typical synthesis method is a liquid phase acetylation method using a carboxylic acid anhydride-acetic acid-sulfuric acid catalyst. Specifically, cellulose raw materials such as cotton linter and wood pulp are pretreated with an appropriate amount of acetic acid, and then put into a pre-cooled carboxylated mixed solution to be esterified to complete cellulose acylate (2nd, 3rd and 6th). The total degree of acyl substitution at the position is approximately 3.00). The carboxylated mixed solution generally contains acetic acid as a solvent, carboxylic anhydride as an esterifying agent, and sulfuric acid as a catalyst. The carboxylic anhydride is usually used in a stoichiometric excess over the sum of the cellulose that reacts with it and the water present in the system. After completion of the acylation reaction, a neutralizing agent (for example, calcium, magnesium, iron, aluminum or zinc) is used for hydrolysis of excess carboxylic anhydride remaining in the system and neutralization of a part of the esterification catalyst. Of carbonate, acetate or oxide). Next, the obtained complete cellulose acylate is saponified and aged by maintaining it at 50 to 90 ° C. in the presence of a small amount of an acetylation reaction catalyst (generally, remaining sulfuric acid) to obtain the desired degree of acyl substitution and polymerization. The cellulose acylate having a degree is changed. When the desired cellulose acylate is obtained, the catalyst remaining in the system is completely neutralized with a neutralizing agent as described above, or in water or dilute sulfuric acid without neutralization. The cellulose acylate solution is added (or water or dilute sulfuric acid is added into the cellulose acylate solution) to separate the cellulose acylate, and the cellulose acylate is obtained by washing and stabilizing treatment.

  The cellulose acylate film of the present invention is preferably composed of a cellulose acylate in which the polymer component constituting the film substantially has the above definition. “Substantially” means 55% by mass or more (preferably 70% by mass or more, more preferably 80% by mass or more) of the polymer component. Cellulose acylate particles are preferably used as a raw material for film production. 90% by mass or more of the particles to be used preferably have a particle diameter of 0.5 to 5 mm. Moreover, it is preferable that 50 mass% or more of the particle | grains to be used have a particle diameter of 1-4 mm. The cellulose acylate particles preferably have a shape as close to a sphere as possible.

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

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 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 of the present invention, its moisture content is preferably 2% by mass or less, more preferably 1% by mass or less, and particularly 0.7% by mass or less. It is a cellulose acylate having a rate. In general, cellulose acylate contains water and is known to be 2.5 to 5% by mass. In order to obtain the moisture content of the cellulose acylate in the present invention, it is necessary to dry, and the method is not particularly limited as long as the desired moisture content is obtained.
These cellulose acylates used in the present invention are described on pages 7 to 12 of the Japan Society for Invention and Technology (Publication No. 2001-1745, published on March 15, 2001, Japan Society of Inventions). It is described in detail.

[Manufacture of optical resin film]
The optical resin film of the present invention is produced by a solvent cast method. In the solvent cast method, a film is produced using a solution (dope) in which an optical resin is dissolved in an organic solvent.
The organic solvent is a solvent selected from ethers having 3 to 12 carbon atoms, ketones having 3 to 12 carbon atoms, esters having 3 to 12 carbon atoms, and halogenated hydrocarbons having 1 to 6 carbon atoms. It is preferable to contain.
The ether, ketone and ester may have a cyclic structure. A compound having two or more functional groups of ether, ketone and ester (that is, —O—, —CO— and —COO—) can also be used as the organic solvent. The organic solvent may have another functional group such as an alcoholic hydroxyl group. In the case of an organic solvent having two or more types of functional groups, the number of carbon atoms is preferably within the above-described preferable range of carbon atoms of the solvent having any functional group.

Examples of the ether having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole.
Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclohexanone and methylcyclohexanone.
Examples of the esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate.
Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol.
The number of carbon atoms of the halogenated hydrocarbon is preferably 1 or 2, and most preferably 1. The halogen of the halogenated hydrocarbon is preferably chlorine. The proportion of halogenated hydrocarbon hydrogen atoms substituted with halogen is preferably 25 to 75 mol%, more preferably 30 to 70 mol%, and more preferably 35 to 65 mol%. More preferably, it is 40 to 60 mol%, and most preferably. Methylene chloride is a representative halogenated hydrocarbon.
The organic solvent of the present invention is preferably used by mixing methylene chloride and alcohol, and the ratio of alcohol to methylene chloride is preferably 1% by mass to 50% by mass, preferably 10% by mass to 40% by mass, and 12% by mass. % To 30% by mass is most preferable. As the alcohol, methanol, ethanol, and n-butanol are preferable, and two or more kinds of alcohols may be mixed and used.

A cellulose acylate solution can be prepared by a general method comprising processing at a temperature of 0 ° C. or higher (ordinary temperature or high temperature). The solution can be prepared using a dope preparation method and apparatus in a normal solvent cast method.
The amount of cellulose acylate is adjusted so that it is contained in an amount of 10 to 40% by mass in the resulting solution. The amount of cellulose acylate is more preferably 10 to 30% by mass. Arbitrary additives described later may be added to the organic solvent (main solvent).
The solution can be prepared by stirring cellulose acylate and an organic solvent at room temperature (0 to 40 ° C.). High concentration solutions may be stirred under pressure and heating conditions. Specifically, cellulose acylate and an organic solvent are placed in a pressure vessel and sealed, and stirred while heating to a temperature not lower than the boiling point of the solvent at normal temperature and in a range where the solvent does not boil.
The heating temperature is usually 40 ° C. or higher, preferably 60 to 200 ° C., more preferably 80 to 110 ° C.

Each component may be coarsely mixed in advance and then placed in a container. Moreover, you may put into a container sequentially. The container must be configured to allow stirring. The container can be pressurized by injecting an inert gas such as nitrogen gas. Moreover, you may utilize the raise of the vapor pressure of the solvent by heating. Or after sealing a container, you may add each component under pressure.
When heating, it is preferable to heat from the outside of the container. For example, a jacket type heating device can be used. Further, the entire container can be heated by providing a plate heater outside the container and piping to circulate the liquid.
It is preferable to provide a stirring blade inside the container and use this to stir. The stirring blade preferably has a length that reaches the vicinity of the wall of the container. A scraping blade is preferably provided at the end of the stirring blade in order to renew the liquid film on the vessel wall.
Instruments such as a pressure gauge and a thermometer may be installed in the container. Each component is dissolved in a solvent in the container. The prepared dope is taken out of the container after cooling, or taken out and then cooled using a heat exchanger or the like.

A solution can also be prepared by a cooling dissolution method. In the cooling dissolution method, cellulose acylate can be dissolved in an organic solvent that is difficult to dissolve by a normal dissolution method. In addition, even if it is a solvent which can melt | dissolve a cellulose acylate with a normal melt | dissolution method, there exists an effect that a uniform solution can be obtained rapidly according to a cooling melt | dissolution method.
In the cooling dissolution method, first, cellulose acylate is gradually added to an organic solvent at room temperature while stirring.
The amount of cellulose acylate is preferably adjusted so as to be contained in the mixture in an amount of 10 to 40% by mass. The amount of cellulose acylate is more preferably 10 to 30% by mass. Furthermore, you may add the arbitrary additive mentioned later in a mixture.

The mixture is then cooled to -100 to -10 ° C (preferably -80 to -10 ° C, more preferably -50 to -20 ° C, most preferably -50 to -30 ° C). The cooling can be performed, for example, in a dry ice / methanol bath (−75 ° C.) or a cooled diethylene glycol solution (−30 to −20 ° C.). The mixture of the cellulose acylate and the organic solvent is solidified by cooling.
The cooling rate is preferably 4 ° C./min or more, more preferably 8 ° C./min or more, and most preferably 12 ° C./min or more. The faster the cooling rate, the better. However, 10,000 ° C./second is the theoretical upper limit, 1000 ° C./second is the technical upper limit, and 100 ° C./second is the practical upper limit. The cooling rate is a value obtained by dividing the difference between the temperature at the start of cooling and the final cooling temperature by the time from the start of cooling to the final cooling temperature.

Furthermore, when this is heated to 0 to 200 ° C. (preferably 0 to 150 ° C., more preferably 0 to 120 ° C., most preferably 0 to 50 ° C.), cellulose acylate dissolves in the organic solvent. The temperature may be increased by simply leaving it at room temperature or in a warm bath.
The heating rate is preferably 4 ° C./min or more, more preferably 8 ° C./min or more, and most preferably 12 ° C./min or more. The higher the heating rate, the better. However, 10,000 ° C./second is the theoretical upper limit, 1000 ° C./second is the technical upper limit, and 100 ° C./second is the practical upper limit. The heating rate is the value obtained by dividing the difference between the temperature at the start of heating and the final heating temperature by the time from the start of heating until the final heating temperature is reached. is there.
A uniform solution is obtained as described above. If the dissolution is insufficient, the cooling and heating operations may be repeated. Whether or not the dissolution is sufficient can be determined by merely observing the appearance of the solution with the naked eye.

In the cooling dissolution method, it is desirable to use a sealed container in order to avoid moisture mixing due to condensation during cooling. In the cooling and heating operation, when the pressure is applied during cooling and the pressure is reduced during heating, the dissolution time can be shortened. In order to perform pressurization and decompression, it is desirable to use a pressure-resistant container.
In addition, according to the measurement by a differential scanning calorimeter (DSC), the 20 mass% solution which melt | dissolved cellulose acetate (acetylation degree: 60.9%, viscosity average polymerization degree: 299) in methyl acetate by the cooling dissolution method is. In the vicinity of 33 ° C., there exists a quasi-phase transition point between a sol state and a gel state, and a uniform gel state is obtained below this temperature. Therefore, it is necessary to keep this solution at a temperature equal to or higher than the pseudo phase transition temperature, preferably about 10 ° C. plus the gel phase transition temperature. However, this pseudo phase transition temperature varies depending on the degree of acetylation of cellulose acetate, the degree of viscosity average polymerization, the concentration of the solution, and the organic solvent used.

  A cellulose acylate film is produced from the prepared cellulose acylate solution (dope) by a solvent cast method. The dope is cast on a drum or band and the solvent is evaporated to form a film. It is preferable to adjust the concentration of the dope before casting so that the solid content is 18 to 35%. The surface of the drum or band is preferably finished in a mirror state. The dope is preferably cast on a drum or band having a surface temperature of 10 ° C. or less.

  As for the drying method in the solvent casting method, U.S. Pat. Nos. 2,336,310, 2,367,603, 2,429,078, 2,429,297, 2,429,978, 2,607,704, 2,739,69, 2,739,070, British Patents 6,407,331, 7,36892 Nos. 45-4554, 49-5614, JP-A-60-176834, JP-A-60-203430, and JP-A-62-115035. Drying on the band or drum can be performed by blowing an inert gas such as air or nitrogen.

  The obtained film can be peeled off from the drum or band, and further dried by high-temperature air whose temperature is successively changed from 100 to 160 ° C. to evaporate the residual solvent. The above method is described in Japanese Patent Publication No. 5-17844. According to this method, it is possible to shorten the time from casting to stripping. In order to carry out this method, it is necessary for the dope to gel at the surface temperature of the drum or band during casting.

  The ratio of residual solvent methylene chloride to alcohol is preferably 15% or more and 90% or less, more preferably 25% or more and 85% or less, and most preferably 35% or more and 80% or less.

  Two or more layers can be cast using the prepared cellulose acylate solution (dope) to form a film. In this case, it is preferable to produce a cellulose acylate film by a solvent cast method. The dope is cast on a drum or band and the solvent is evaporated to form a film. It is preferable to adjust the concentration of the dope before casting so that the solid content is in the range of 10 to 40%. The surface of the drum or band is preferably finished in a mirror state.

  When casting a plurality of cellulose acylate solutions of two or more layers, it is possible to cast a plurality of cellulose acylate solutions, from a plurality of casting openings provided at intervals in the direction of travel of the support. You may produce a film, casting and laminating the solution containing a cellulose acylate, respectively. For example, the methods described in JP-A-61-158414, JP-A-1-122419, and JP-A-11-198285 can be used. It can also be formed into a film by casting a cellulose acylate solution from two casting ports. For example, JP-B-60-27562, JP-A-61-94724, JP-A-61-947245, JP-A-61-104413, JP-A-61-158413, and JP-A-6-134933. The method described in each publication can be used. Further, a cellulose acylate film is disclosed in which a flow of a high-viscosity cellulose acylate solution described in JP-A-56-162617 is wrapped with a low-viscosity cellulose acylate solution, and the high- and low-viscosity cellulose acylate solution is extruded simultaneously. A casting method can also be used.

Also, using two casting ports, the film formed on the support by the first casting port is peeled off, and the second casting is performed on the side that was in contact with the support surface to produce a film. You can also For example, the method described in Japanese Patent Publication No. 44-20235 can be mentioned.
As the cellulose acylate solution to be cast, the same solution may be used, or different cellulose acylate solutions may be used. In order to give a function to a plurality of cellulose acylate layers, a cellulose acylate solution corresponding to the function may be extruded from each casting port. Furthermore, the cellulose acylate solution of the present invention can be cast simultaneously with other functional layers (for example, an adhesive layer, a dye layer, an antistatic layer, an antihalation layer, an ultraviolet absorption layer, a polarizing layer, etc.).

  In the conventional single-layer solution, it is necessary to extrude a cellulose acylate solution having a high concentration and a high viscosity in order to obtain a necessary film thickness. In such a case, the stability of the cellulose acylate solution is poor and solid matter is generated, which often causes problems due to defects or poor flatness. As a solution to this problem, by casting a plurality of cellulose acylate solutions from the casting port, it is possible to extrude a highly viscous solution onto the support at the same time, improving the flatness and improving the planar film. Not only can be produced, but also the use of a concentrated cellulose acylate solution can reduce the drying load and increase the production speed of the film.

[Stretching treatment]
In the cellulose acylate film of the present invention, the retardation can be adjusted by a stretching treatment. Furthermore, there is also a method of positively stretching in the width direction. -48271, and the like. In this method, the produced film is stretched in order to increase the in-plane retardation value of the cellulose acylate film.
The film is stretched at room temperature or under heating conditions. The heating temperature is preferably not higher than the glass transition temperature of the film. The stretching of the film may be uniaxial stretching only in the longitudinal or lateral direction, or may be simultaneous or sequential biaxial stretching. Stretching is performed at 1 to 200%. The stretching is preferably 1 to 100%, particularly preferably 1 to 50%. The birefringence of the optical film is preferably such that the refractive index in the width direction is larger than the refractive index in the length direction. Therefore, it is preferable to stretch more in the width direction. In addition, the stretching process may be performed in the middle of the film forming process, or the raw film that has been formed and wound may be stretched. In the former case, the stretching may be performed in a state including the residual solvent amount, and the stretching can be preferably performed at a residual solvent amount of 2 to 40%.

In order to improve the mechanical properties of the cellulose acylate film, the following plasticizers can be used. As the plasticizer, phosphoric acid ester or carboxylic acid ester is used. Examples of phosphate esters include triphenyl phosphate (TPP) and tricresyl phosphate (TCP). Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethyl hexyl phthalate (DEHP). Examples of citrate esters include triethyl O-acetylcitrate (OACTE) and tributyl O-acetylcitrate (OACTB). Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Phthalate plasticizers (DMP, DEP, DBP, DOP, DPP, DEHP) are preferably used. DEP and DPP are particularly preferred.
The addition amount of the plasticizer is preferably 0.1 to 25% by mass, more preferably 1 to 20% by mass, and most preferably 3 to 15% by mass of the amount of cellulose acylate.

  A degradation inhibitor (eg, antioxidant, peroxide decomposer, radical inhibitor, metal deactivator, acid scavenger, amine) may be added to the cellulose acylate film. The deterioration preventing agents are described in JP-A-3-199201, JP-A-51907073, JP-A-5-194789, JP-A-5-271471, and JP-A-6-107854. The addition amount of the deterioration preventing agent is preferably 0.01 to 1% by mass of the solution (dope) to be prepared, and more preferably 0.01 to 0.2% by mass. When the addition amount is in the above range, the effect of the deterioration preventing agent can be obtained, and bleed out (bleeding) to the film surface is not recognized, which is preferable. Examples of particularly preferred deterioration inhibitors include butylated hydroxytoluene (BHT) and tribenzylamine (TBA).

[Matting agent fine particles]
It is preferable to add fine particles 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, silica Mention may be made of magnesium and calcium phosphates. Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable. The silicon dioxide fine particles 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 diameter of 0.1 to 3.0 μm, and these fine particles are present as aggregates of primary particles in the film, and 0.1 to 0.1 μm on the film surface. An unevenness of 3.0 μm is formed. The secondary average particle size is preferably from 0.2 μm to 1.5 μm, more preferably from 0.4 μm to 1.2 μm, and most preferably from 0.6 μm to 1.1 μm. The primary and secondary particle sizes were determined by observing the particles in the film with a scanning electron microscope and determining the diameter of a circle circumscribing the particles 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 fine particles of silicon dioxide, for example, commercially available products such as Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.) can be used. Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used.

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

In order to obtain a cellulose acylate film having particles having a small secondary average particle size in the present invention, several methods are conceivable when preparing a fine particle dispersion. For example, a method of preparing a fine particle dispersion in which a solvent and fine particles are stirred and mixed in advance, adding the fine particle dispersion to a small amount of cellulose acylate solution separately prepared, stirring and dissolving, and further mixing with a main cellulose acylate dope solution There is. This method is a preferred 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 it with a disperser to make this fine particle additive solution. There is also a way to do it. 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%. Mass% is most preferred. A higher dispersion concentration is preferable because the liquid turbidity with respect to the added amount is lowered, and haze and aggregates are improved. The addition amount of the matting agent in the final cellulose 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.

  The winder used for the production of the cellulose acylate film used in the present invention may be a commonly used winder such as a constant tension method, a constant torque method, a taper tension method, or a program tension control method with a constant internal stress. It can be wound up by a take-up method.

[Glass transition temperature of cellulose acylate film]
The glass transition temperature of the cellulose acylate film can be measured by the method described in JIS standard K7121.
The glass transition temperature of the cellulose acylate film of the present invention is preferably from 80 ° C. to 200 ° C., more preferably from 100 ° C. to 170 ° C. The glass transition temperature can be lowered by including a low molecular compound such as a plasticizer or a solvent.

[Film thickness]
The thickness (dry film thickness) of the cellulose acylate film of the present invention is preferably from 40 μm to 110 μm, and more preferably from 50 μm to 100 μm.

<Cycloolefin polymer film>
Next, the cycloolefin type polymer used for the polarizing plate protective film of this invention is demonstrated in detail.
(Cycloolefin-based addition polymer)
The cycloolefin polymer used in the polarizing plate protective film of the present invention has a suitable ratio of the structural unit (a) represented by the following general formula (1) and the structural unit (b) represented by the following general formula (2). The cycloolefin type addition polymer contained in is preferable.

[A ₁ , A ₂ , A ₃ and A _{4 in the} formula (1) are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group, a cycloalkyl group having 4 to 15 carbon atoms, or a halogen atom. It is. A _{1 to} A ₄ also include an alkylene group formed from A ₁ and A ₂ , A ₁ and A _3, or A ₂ and A ₄ . r represents an integer of 0-2.

  Such a structural unit (a) is formed by addition polymerization of a cycloolefin compound represented by the following formula (2) (hereinafter referred to as “specific monomer (1)”).

[A ₁ , A ₂ , A ₃ and A _{4 in the} formula (2) are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group, a cycloalkyl group having 4 to 15 carbon atoms, or a halogen atom. It is. A _{1 to} A ₄ also include an alkylene group and an alkylidene group formed from A ₁ and A ₂ , A ₁ and A _3, or A ₂ and A ₄ . r represents an integer of 0-2. ]

  Specific examples of the “specific monomer (1)” represented by the formula (2) include bicyclo [2.2.1] hept-2-ene and 5-methyl-bicyclo [2.2.1]. Hept-2-ene, 5-ethyl-bicyclo [2.2.1] hept-2-ene, 5-propyl-bicyclo [2.2.1] hept-2-ene, 5-butyl-bicyclo [2. 2.1] Hept-2-ene, 5-pentyl-bicyclo [2.2.1] hept-2-ene, 5-hexyl-bicyclo [2.2.1] hept-2-ene, 5-heptyl- Bicyclo [2.2.1] hept-2-ene, 5-octyl-bicyclo [2.2.1] hept-2-ene, 5-decyl-bicyclo [2.2.1] hept-2-ene, 5-dodecyl-bicyclo [2.2.1] hept-2-ene, 5,6-dimethyl-bicyclo [2.2. ] Hept-2-ene, 5-methyl-5-ethyl-bicyclo [2.2.1] hept-2-ene, 5-phenyl-bicyclo [2.2.1] hept-2-ene, 5-cyclohexyl -Bicyclo [2.2.1] hept-2-ene, 5-cyclooctyl-bicyclo [2.2.1] hept-2-ene, 5-fluoro-bicyclo [2.2.1] hept-2-ene Ene, 5-chloro-bicyclo [2.2.1] hept-2-ene, tricyclo [4.2.015,8] non-2-ene, 1-methyltricyclo [4.2.0. 15,8] nona-2-ene, 6-methyltricyclo [4.2.0.15,8] nona-2-ene, tricyclo [5.2.1.02,6] dec-8-ene, 3-methyltricyclo [5.2.1.02,6] dec-8-ene, 4-methyltricyclo [ .2.1.02,6] dec-8-ene, tricyclo [6.2.1.02,7] undec-9-ene, 1-methyltricyclo [6.2.1.02,7] undeca -9-ene, 3-methyltricyclo [6.2.1.02,7] undec-9-ene, 1-ethyltricyclo [6.2.1.02,7] undec-9-ene, 3 -Ethyltricyclo [6.2.1.02,7] undec-9-ene, tricyclo [8.2.1.02,9] tridec-11-ene, 1-methyltricyclo [8.2.1 .02,9] tridec-11-ene, 5-methyltricyclo [8.2.1.02,9] tridec-11-ene, tetracyclo [4.4.0.12,5.17,10] dodeca -3-ene, 8-methyl-tetracyclo [4.4.0.12,517,10] dodeca- 3-ene, 8-ethyl-tetracyclo [4.4.0.12,517,10] dodec-3-ene, and the like.

  Also, 5-vinyl-bicyclo [2.2.1] hept-2-ene, 5- (1-butenyl) -bicyclo [2.2.1] hept-2-ene, tricyclo [5.2.1. 02,6] deca-3,8-diene, 1-methyltricyclo [5.2.1.02,6] deca-3,8-diene, 1-ethyltricyclo [5.2.1.02, 6] Addition polymerization of a cyclic diolefin compound such as deca-3,8-diene, and then hydrogenate the cycloolefinically unsaturated bond present in the side chain to obtain the structural unit (a). be able to.

  Among these “specific monomers (1)”, preferred are bicyclo [2.2.1] hept-2-ene or tricyclo [5.2.1.02,6] dec-8-ene. is there. In tricyclo [5.2.1.02,6] dec-8-ene, there are endo and exo stereoisomers, but in the present invention, the endo isomer is the final one. Therefore, it is preferable to use tricyclo [5.2.1.02,6] dec-8-ene having an endo content of at least 80%. Further, there is a method in which addition polymerization is carried out using endo-form tricyclo [5.2.1.02,6] deca-3,8-diene, and the cycloolefinic unsaturated bond remaining in the rear side chain is hydrogenated. Likewise preferred. Even in this case, the endo-form content is preferably 80% or more. The cycloolefin polymer obtained by using these is not only excellent in transparency and heat resistance, but also becomes a polymer having low water absorption, low dielectric property, and high toughness. The “specific monomer (1)” can be used alone or in combination of two or more.

  The structural unit (b) represented by the following formula (3) is subjected to addition polymerization of a cycloolefin represented by the following formula (4) (hereinafter referred to as “specific monomer (2)”). It is formed.

[In formula (3), B _{1 to} B ₄ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, a halogenated alkyl group, a hydrolyzable silyl group, or — (CH ₂ ) jX. And at least one of B _{1 to} B ₄ includes a hydrolyzable silyl group or a polar group represented by — (CH ₂ ) jX. Here, X is —C (O) OR ¹ or —OC (O) R ² , and R ¹ and R ² are each an alkyl group having 1 to 10 carbon atoms, an alkenyl group, a cycloalkyl group, an aryl group, or The substituent selected from the group consisting of these halogen substituents, j is an integer of 0-3. B _{1 to} B ₄ also include an alkylene group formed from B ₁ and B ₃ or B ₂ and B ₄ , and an alkylidenyl group formed from B ₁ and B ₂ or B ₃ and B ₄ . p shows the integer of 0-2.

Wherein _(4), B ₁ ~B 4 is the same as equation (3). p shows the integer of 0-2. ]

  Specific examples of such “specific monomer (2)” include, for example, the following compounds, but the present invention is not limited to these specific examples. 5-methoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5-ethoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5-butoxycarbonyl-bicyclo [2.2.1] ] Hept-2-ene, 5-methyl-5-methoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5-methyl-5-ethoxycarbonyl-bicyclo [2.2.1] hept-2 -Ene, 5-methyl-5-propoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5-methyl-5-butoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5 -Ethyl-5-methoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5-methyl-5-trifluoromethoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5-me Ru-bicyclo [2.2.1] hept-2-en-5-ylmethylcarboxylate, acrylate-1-methyl-bicyclo [2.2.1] hept-3-ene, methacrylic acid-1- Methyl-bicyclo [2.2.1] hept-3-ene, 5,6-di (methoxycarbonyl) -bicyclo [2.2.1] hept-2-ene, 5,6-di (methoxycarbonyl)- Bicyclo [2.2.1] hept-2-ene, 8-methyl-8-methoxycarbonyl-tetracyclo [4.4.0.12,5.17,10] dodec-3-ene, 8-methyl-8 -Ethoxycarbonyl-tetracyclo [4.4.0.12,5.17,10] dodec-3-ene, 5-trimethoxysilyl-bicyclo [2.2.1] hept-2-ene, 5-dimethoxychloro Silyl-bicyclo [2. .1] hept-2-ene, 5-methoxychloromethylsilyl-bicyclo [2.2.1] hept-2-ene, 5-dimethoxychlorosilyl-bicyclo [2.2.1] hept-2-ene, 5-methoxyhydridomethylsilyl-bicyclo [2.2.1] hept-2-ene, 5-dimethoxyhydridosilyl-bicyclo [2.2.1] hept-2-ene, 5-methoxydimethylsilyl-bicyclo [2] 2.1] hept-2-ene, 5-triethoxysilyl-bicyclo [2.2.1] hept-2-ene, 5-diethoxychlorosilyl-bicyclo [2.2.1] hept-2- Ene, 5-ethoxychloromethylsilyl-bicyclo [2.2.1] hept-2-ene, 5-diethoxyhydridosilyl-bicyclo [2.2.1] hept-2-ene, 5-ethoxydimethyl Tylsilyl-bicyclo [2.2.1] hept-2-ene, 5-ethoxydiethylsilyl-bicyclo [2.2.1] hept-2-ene, 5-propoxydimethylsilyl-bicyclo [2.2.1] Hept-2-ene, 5-tripropoxysilyl-bicyclo [2.2.1] hept-2-ene, 5-triphenoxysilyl-bicyclo [2.2.1] hept-2-ene, 5-trimethoxy Silylmethyl-bicyclo [2.2.1] hept-2-ene, 5-dimethylchlorosilyl-bicyclo [2.2.1] hept-2-ene, 5-methyldichlorosilyl-bicyclo [2.2.1] ] Hept-2-ene, 5-trichlorosilyl-bicyclo [2.2.1] hept-2-ene, 5-diethylchlorosilyl-bicyclo [2.2.1] hept-2-ene, 5-ethyldic Rosilyl-bicyclo [2.2.1] hept-2-ene, 5- (2-trimethoxysilyl) ethyl-bicyclo [2.2.1] hept-2-ene, 5- (2-dimethoxychlorosilyl) Ethyl-bicyclo [2.2.1] hept-2-ene, 5- (1-trimethoxysilyl) ethyl-bicyclo [2.2.1] hept-2-ene, 5- (2-trimethoxysilyl) Propyl-bicyclo [2.2.1] hept-2-ene, 5- (1-trimethoxysilyl) propyl-bicyclo [2.2.1] hept-2-ene, 5-triethoxysilylethyl-bicyclo [ 2.2.1] Hept-2-ene, 5-dimethoxymethylsilylmethyl-bicyclo [2.2.1] hept-2-ene, 5-trimethoxypropylsilyl-bicyclo [2.2.1] hept- 2-ene, -Methyl-5- (3-triethoxysilyl) propoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 8-triethoxysilyl-tetracyclo [4.4.0.12, 5.17,10 ] Dodec-3-ene, 8-methyldimethoxysilyl-tetracyclo [4.4.0.12, 5.17,10] dodec-3-ene, 5- [1'-methyl-2 ', 5'-dioxa -1′-silacyclopentyl] -bicyclo [2.2.1] hept-2-ene, 5- [1′-methyl-3 ′, 3 ′, 4 ′, 4′-tetraphenyl-2 ′, 5 ′ -Dioxa-1'-silacyclopentyl] -bicyclo [2.2.1] hept-2-ene, 5- [1'-methyl-3 ', 3', 4 ', 4'-tetramethyl-2', 5′-Dioxa-1′-silacyclopentyl] -bicyclo [2 2.1] hept-2-ene, 5- [1′-phenyl-2 ′, 5′-dioxa-1′-silacyclopentyl] -bicyclo [2.2.1] hept-2-ene, 5- [1′-Ethyl-2 ′, 5′-dioxa-1′-silacyclopentyl] -bicyclo [2.2.1] hept-2-ene, 5- [1 ′, 3′-dimethyl-2 ′, 5 '-Dioxa-1'-silacyclopentyl] -bicyclo [2.2.1] hept-2-ene, 5- [1'-methyl-3', 4'-dimethyl-2 ', 5'-dioxa-1 '-Silacyclopentyl] -bicyclo [2.2.1] hept-2-ene, 5- [1'-methyl-2', 6'-dioxa-1'-silacyclohexyl] -bicyclo [2.2.1 ] Hept-2-ene, 5- [1'-ethyl-2 ', 6'-dioxa-1'-silacy Hexyl] -bicyclo [2.2.1] hept-2-ene, 5- [1 ′, 3′-dimethyl-2 ′, 6′-dioxa-1′-silacyclohexyl] -bicyclo [2.2.1 ] Hept-2-ene, 5- [1′-methyl-4 ′, 4′-dimethyl-2 ′, 6′-dioxa-1′-silacyclohexyl] -bicyclo [2.2.1] hept-2- Ene, 5- [1′-methyl-4 ′, 4′-dimethyl-2 ′, 6′-dioxa-1′-silacyclohexyl] methyl-bicyclo [2.2.1] hept-2-ene, 5- [1′-Methyl-4 ′, 4′-dimethyl-2 ′, 6′-dioxa-1′-silacyclohexyl] ethyl-bicyclo [2.2.1] hept-2-ene, 5- [1′- Phenyl-4 ′, 4′-dimethyl-2 ′, 6′-dioxa-1′-silacyclohex L] -bicyclo [2.2.1] hept-2-ene, 5- [1′-methyl-4′-phenyl-2 ′, 6′-dioxa-1′-silacyclohexyl] -bicyclo [2.2 .1] Hept-2-ene, 5- [1′-methyl-4′-spiro-cyclohexyl-2 ′, 6′-dioxa-1′-silacyclohexyl] -bicyclo [2.2.1] hept-2 -Ene, 5- [1'-methyl-4'-ethyl-4'-butyl-2 ', 6'-dioxa-1'-silacyclohexyl] -bicyclo [2.2.1] hept-2-ene, 5- [1′-methyl-3 ′, 3′-dimethyl-5′methylene-2 ′, 6′-dioxa-1′-silacyclohexyl] -bicyclo [2.2.1] hept-2-ene, 5 -[1'-phenyl-2 ', 6'-dioxa-1'-silacyclohexyl] -Bicyclo [2.2.1] hept-2-ene, 5- [1'-methyl-3'-phenyl-2 ', 6'-dioxa-1'-silacyclohexyl] -bicyclo [2.2.1 ] Hept-2-ene, 5- [1′-methyl-4 ′, 4′-dimethyl-2 ′, 6′-dioxa-1′-silacyclohexyl] -7-oxa-bicyclo [2.2.1] Hept-2-ene, 5- [1′-methyl-2 ′, 6′-dioxa-1′-silacyclohexyl] -7-oxa-bicyclo [2.2.1] hept-2-ene, 5- [ 1'-methyl-2 ', 7'-dioxa-1'-silacycloheptyl] -bicyclo [2.2.1] hept-2-ene, 8- [1'-methyl-4', 4'-dimethyl -2 ', 6'-dioxa-1'-silacyclohexyl] -tetracyclo [4.4.0.12 517,10] dodec-3-ene, 8- [1′-methyl-2 ′, 6′-dioxa-1′-silacyclohexyl] -tetracyclo [4.4.0.12,517,10] dodeca-3 -Ene, 8-methyl-8-carboxymethyl-9-carboxymethyltetracyclo [4.4.0.12,5. 17, 10] -3-dodecene, and the like. These “specific monomers (2)” can be used alone or in combination of two or more.

  The proportion of the structural unit (b) contained in the cycloolefin-based polymer of the present invention is 5 to 95 mol%, preferably 10 to 90 mol%, more preferably 20 to 80 mol% in all structural units. If the proportion of the structural unit (b) of the cycloolefin polymer is too small, the adhesion / adhesion with the polyvinyl alcohol used in the polarizer may be poor. On the other hand, when the ratio is too large, the hygroscopicity is increased and the dimensional stability is inferior. The arrangement of the structural units (b) is not limited, such as random or block, in the cycloolefin polymer, but is preferably random. Further, the cycloolefin addition polymer containing the structural unit (b) having a reactive substituent such as a hydrolyzable silyl group, an ester group, an acryloyl group, or a methacryloyl group as a side chain substituent uses a crosslinking agent described later. Thus, the cycloolefin polymer film of the present invention can be made into a crosslinked product.

  In the cycloolefin polymer of the present invention, a structural unit (c) obtained by addition polymerization of a “specific α-olefin compound” can be further introduced.

  Specific examples of such “specific α-olefin compound” include ethylene, propylene, 1-butene, 1-hexene, 1-octene, trimethylsilylethylene, triethylsilylethylene, styrene, and the like. Ethylene is preferable.

  By introducing the repeating unit (c) derived from the “specific α-olefin compound” into the polymer, the glass transition temperature of the cycloolefin polymer of the present invention can be controlled. The ratio of the repeating unit (c) contained in the cycloolefin polymer of the present invention is 0 to 30 mol%, preferably 0 to 20 mol%. In addition, when the ratio of the repeating unit (c) exceeds 30 mol%, the glass transition temperature of the cycloolefin polymer of the present invention is as low as 170 ° C. or less, and the heat resistance is lowered, which is not preferable.

  The molecular weight of the cycloolefin polymer of the present invention is expressed in terms of polystyrene, the number average molecular weight is 10,000 to 300,000, the weight average molecular weight is 20,000 to 700,000, preferably the number average molecular weight is 20, The molecular weight is 50,000 to 200,000, the weight average molecular weight is 50,000 to 500,000, more preferably the number average molecular weight is 50,000 to 150,000, and the weight average molecular weight is 100,000 to 300,000. When the number average molecular weight is less than 10,000 and the weight average molecular weight is less than 20,000, the film may be inferior in toughness and easily cracked. On the other hand, when the number average molecular weight exceeds 300,000 and the weight average molecular weight exceeds 700,000, the solution viscosity increases, and the workability of film formation by the solution casting method, the surface of the obtained film, and the like may be deteriorated. .

  The glass transition temperature of the cycloolefin polymer of the present invention is 180 to 450 ° C., preferably 200 to 400 ° C. in an uncrosslinked state. When the glass transition temperature of the polymer is less than 180 ° C., the heat resistance is insufficient. On the other hand, when it exceeds 450 ° C., the film may not be tough and may be easily broken.

  The cycloolefin polymer of the present invention mainly uses the “specific monomer (1)” and, if necessary, uses the “specific monomer (2)” for cross-linking formation or adhesion / adhesion imparting. Further, it is produced using a “specific α-olefin compound” for controlling the glass transition temperature as required. Hereinafter, the manufacturing method will be described.

  Examples of the polymerization catalyst include single complex catalysts and multi-component catalysts such as palladium, nickel, cobalt, titanium and zircon listed in the following [1], [2] and [3]. It is not limited.

[1] Single complex catalyst such as Pd, Ni [Pd (CH ₃ CN) ₄ ] [BF ₄ ] ₂ , [Pd (PhCN) ₄ ] [SbF ₆ ], [(η3-crotyl) Pd (cyclooctadiene) )] [PF ₆ ], [(η3-crotyl) Ni (cycloocta-1,5-diene)] [B (3,5- (CF ₃ ) ₂ C ₆ F ₃ ) ₄ ], [(η3-crotyl) Ni (cycloocta-1,5-diene)] [PF ₆ ], [(η3-allyl) Ni (cycloocta-1,5-diene)] [B (C ₆ F ₅ ) ₄ ], [(η3-crotyl) Ni (cycloocta-1,5-diene) ] [SbF 6], Toluene · Ni (C 6 F 5) 2, Benzene · Ni (C 6 F 5) 2, mesitylene · Ni (C 6 F 5) 2 Ethyle _{her · Ni (C 6 F 5} ) 2,

[2] Multi-component catalyst di- [mu] -chloro-bis (6-methoxybicyclo [2.2.1] hept-2- by combination of palladium complex having [sigma] or [sigma], [pi] bond and organoaluminum or super strong acid salt A combination of en-endo-5σ, 2π) Pd and a compound selected from methylalumoxane (abbreviated as MAO), AgSbF ₆ , and AgBF ₄ . A combination of [(η3-aryl) PdCl] ₂ and AgSbF ₆ or AgBF ₄ . A combination of [(1,5-cyclooctadiene) Pd (CH ₃ ) Cl], PPh ₃ and NaB [3,5- (CF ₃ ) ₂ C ₆ H ₃ ] ₄ . The combination of these is mentioned.

[3] 1) transition metal compounds selected from nickel compounds, cobalt compounds, titanium compounds or zircon compounds, 2) compounds selected from superacids, Lewis acids and ionic boron compounds, and 3) A multi-component catalyst containing an organoaluminum compound.

1) Transition metal compound 1-1) Nickel compound, cobalt compound: at least one compound selected from the following group, organic carboxylate of nickel or cobalt, organic phosphite, organic phosphate, organic Compounds selected from sulfonates, β-diketone compounds and the like. For example, nickel 2-ethylhexanoate, nickel naphthenate, cobalt naphthenate, nickel oleate, nickel dodecanoate, cobalt dodecanoate, cobalt neodecanoate, nickel dodecylbenzenesulfonate, bis (acetylacetonato) nickel, bis (ethyl Acetoacetate) nickel etc. A compound obtained by modifying the above organic carboxylate of nickel with a super strong acid such as hexafluoroantimonic acid, tetrafluoroboric acid, trifluoroacetic acid, hexafluoroacetone, or the like, a nickel diene or triene coordination complex, for example, Dichloro (1,5-cyclooctadiene) nickel, [(η3-crotyl) (1,5-cyclooctadiene) nickel] hexafluorophosphate, and its tetrafluoroborate, tetrakis [3,5-bis (trifluoromethyl) )] Borate complexes, 5,9-cyclododecatriene) nickel, bis (norbornadiene) nickel, nickel complexes such as bis (1,5-cyclooctadiene) nickel, and nickel having atoms such as P, N, and O Ligands coordinated complexes, such as bis (triphenylphosphine) nickel dichloro Bis (triphenylphosphine) nickel dibromide, bis (triphenylphosphine) cobalt dibromide, bis [N- (3-t-butylsalicylidene) phenylaminate] nickel, Ni [PhC (O) CH] (Ph), Ni (OC ( C 6 H 4) PPh) (H) (PCy 3), Ni [OC (O) (C 6 H 4) P] (H) (PPh 3), bis (1,5 Reaction product of -cyclooctadiene) nickel and PhC (O) CH = PPh ₃ , 6- (i-Pr) ₂ C ₆ H ₃ N═CHC ₆ H ₃ (O) (Anth)] (Ph) (PPh ₃ ) Nickel complexes such as Ni (where Anth is 9-anthracenyl, Ph is phenyl, and Cy is an abbreviation for cyclohexyl).

1-2) Titanium compound, zircon compound: [t-BuNSiMe (Me ₄ Cp)] TiCl ₂ , (Me ₄ Cp) (O-iPr ₂ C ₆ H ₃ ) ₂ TiCl, (Me ₄ Cp) TiCl ₃ , ( Me ₄ Cp) Ti (OBu) ₃ , [t-BuNSiMeFlu] TiMe ₂ , [t-BuNSiMeFlu] TiCl ₂ Et (Ind) ₂ ZrCl ₂ , Ph ₂ C (Ind) (Cp) ZrCl ₂ , iPr (Cp) ( _{Flu) ZrCl 2, iPr (3} -tert-But-Cp) (Ind) ZrCl 2, iPr (Cp) (Ind) ZrCl 2, Me 2 Si (Ind) 2 ZrCl 2, Cp 2 ZrCl 2, [Cp is Cyclopentadienl , Ind is an abbreviation for Indenyl, and Flu is an abbreviation for Fluorenyl. ] Etc. are mentioned.

2) As a compound superacid selected from superacid, Lewis acid compound and ionic boron compound, for example, hexafluoroantimonic acid, hexafluorophosphoric acid, hexafluoroarsenic acid, trifluoroacetic acid, fluorosulfuric acid, trifluoromethanesulfonic acid, Tetrafluoroboric acid, tetrakis (pentafluorophenyl) boric acid, tetrakis [3,5-bis (trifluoromethyl) phenyl] boric acid, p-toluenesulfonic acid, pentafluoropropionic acid and the like can be mentioned. Examples of Lewis acid compounds include complexes of boron trifluoride with ethers, amines, phenols, etc., complexes of aluminum trifluoride ethers, amines, phenols, tris (pentafluorophenyl) borane, tris [3,5 Boron compounds such as bis (trifluoromethyl) phenyl] borane, aluminum compounds such as aluminum trichloride, aluminum tribromide, ethylaluminum dichloride, ethylaluminum sesquichloride, diethylaluminum fluoride, tri (pentafluorophenyl) aluminum , Organic halogen compounds exhibiting Lewis acidity such as hexafluoroacetone, hexachloroacetone, chloranil, hexafluoromethyl ethyl ketone, and other Lewis acidity such as titanium tetrachloride and pentafluoroantimony Such compounds. Examples of the ionic boron compound include triphenylcarbenium tetrakis (pentafluorophenyl) borate, triphenylcarbeniumtetrakis [3,5-bis (trifluoromethyl) phenyl] borate, triphenylcarbeniumtetrakis (2,4 , 6-trifluorophenyl) borate, triphenylcarbenium tetraphenylborate, tributylammonium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, N, N-diethylanilinium tetrakis (Pentafluorophenyl) borate, N, N-diphenylanilinium tetrakis (pentafluorophenyl) borate and the like.

3) Organoaluminum compounds, for example, alkylalumoxane compounds such as methylalumoxane, ethylalumoxane, butylalumoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, diisobutylaluminum hydride, diethylaluminum chloride, diethylaluminum fluoride, ethyl Alkyl aluminum compounds and halogenated alkyl aluminum compounds such as aluminum sesquichloride and ethylaluminum dichloride, or a mixture of the alkylalumoxane compound and the alkylaluminum compound are preferably used.

  The components of the single complex catalyst or multicomponent catalyst are used in the following amounts. Transition metal compounds such as nickel compounds, palladium compounds, cobalt compounds, titanium compounds, and zirconium compounds are 0.02 to 100 millimole atoms per mole of monomer, and organoaluminum compounds are per mole of transition metal compound. 1 to 5,000 mol, and the super strong acid, Lewis acid, and ionic boron compound are 0 to 100 mol with respect to 1 mol atom of the transition metal compound.

  The cycloolefin polymer of the present invention uses a single complex catalyst or a multi-component catalyst composed of the above components, and alicyclic hydrocarbon solvents such as cyclohexane, cyclopentane and methylcyclopentane, hexane, heptane, octane and the like. Aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents such as toluene, benzene, xylene, mesitylene, halogenated hydrocarbon solvents such as dichloromethane, 1,2-dichloroethane, 1,1-dichloroethane, tetrachloroethane, chlorobenzene, dichlorobenzene, etc. From the above, it is obtained by performing polymerization in a temperature range of -20 to 120 ° C. in a solvent selected from one or more.

(Cycloolefin ring-opening polymer)
As the cycloolefin polymer of the present invention, a ring-opening polymer having monomer units of the following general formulas (5) and (6) can also be preferably used.

Wherein (5), m is an integer of 1 or more, p is 0 or an integer of 1 or more, X is a vinylene group (-CH = CH-) or an ethylene group - shows the (-CH ₂ CH ₂₎ , R _{1 to} R ₄ are each independently a hydrogen atom; a halogen atom; a substituted or unsubstituted carbon atom having an linking group containing an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom; 30 hydrocarbon groups; or polar groups.
Further, R ₁ and R ₂ , R ₃ and R ₄ or R ₂ and R ₃ are bonded to each other to form a carbocyclic or heterocyclic ring having a monocyclic structure or other ring condensed to form a polycyclic structure. The formed carbocyclic or heterocyclic ring may be an aromatic ring or a non-aromatic ring. ]

[In Formula (6), Y represents a vinylene group (—CH═CH—) or an ethylene group (—CH ₂ CH ₂ —), and R _{5 to} R ₈ each independently represents a hydrogen atom; a halogen atom; A substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms which may have a linking group containing an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom; or a polar group. Further, R ₅ and R ₆ , R ₇ and R ₈ or R ₆ and R ₇ are bonded to each other, and a carbocyclic or heterocyclic ring having a polycyclic structure by condensing a monocyclic structure or other ring (provided that (Except for the structure represented by the general formula (1)), and the formed carbocyclic or heterocyclic ring may be an aromatic ring or a non-aromatic ring. ]

The polymers of the general formulas (5) and (6) are synthesized as (co) polymers of monomers (hereinafter also referred to as “specific polymers”) shown in the following (A) to (D).
(A) A ring-opening polymer of a compound represented by the following general formula (7) (hereinafter also referred to as “specific monomer d”).
(B) A ring-opening polymer of the specific monomer d and a compound copolymerizable with the specific monomer d (hereinafter also referred to as “copolymerizable monomer”).
(C) A hydrogenated product of the above ring-opening polymer (a) or (b) the ring-opening polymer.
(D) A compound obtained by cyclization of the ring-opened polymer of (a) or (b) by a Friedel-Craft reaction or a hydrogenated product thereof.

Wherein (7), m is an integer of 1 or more, p is 0 or an integer of 1 or more, R ₁ to R ₄ are each independently a hydrogen atom, a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom Or a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms which may have a linking group containing a silicon atom; or a polar group. Further, R ₁ and R ₂ , R ₃ and R ₄ or R ₂ and R ₃ are bonded to each other to form a carbocyclic or heterocyclic ring having a monocyclic structure or other ring condensed to form a polycyclic structure. The formed carbocyclic or heterocyclic ring may be an aromatic ring or a non-aromatic ring. ]

  The specific polymer uses a compound represented by the following general formula (8) as a copolymerizable monomer (hereinafter also referred to as “specific monomer b”), a specific monomer d and a specific monomer. It is preferable that it is a thing obtained by copolymerizing the body b. According to the specific polymer having such a configuration, the finally obtained specific retardation film has more excellent mechanical properties such as toughness, and is required for the specific retardation film by stretching. It becomes easy to obtain a desired phase difference.

[In formula (8), R < ₅ > -R < ₈ > is each independently substituted or unsubstituted which may have a hydrogen atom; a halogen atom; an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom. Or a hydrocarbon group having 1 to 30 carbon atoms; or a polar group. Further, R ₅ and R ₆ , R ₇ and R ₈ or R ₆ and R ₇ are bonded to each other, and a carbocyclic or heterocyclic ring having a polycyclic structure by condensing a monocyclic structure or other ring (provided that (Except for the structure represented by the general formula (5)), and the formed carbocyclic or heterocyclic ring may be an aromatic ring or a non-aromatic ring. ]

  Furthermore, the specific polymer is a ring-opening polymer of the specific monomer d and the specific monomer e, and is a structural unit derived from the specific monomer a represented by the above general formula (5) (hereinafter referred to as “the structural unit”). And a structural unit derived from the specific monomer e represented by the general formula (6) (hereinafter also referred to as “structural unit e”). It is preferable. The specific polymer having such a configuration is preferable in that a balance between heat resistance and heat processability by stretching or the like can be achieved.

As a halogen atom in General formula (7)-General formula (8), a fluorine atom, a chlorine atom, and a bromine atom are mentioned.
Examples of the hydrocarbon group having 1 to 30 carbon atoms include alkyl groups such as methyl group, ethyl group, and propyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; alkenyl groups such as vinyl group, allyl group, and propenyl group. Etc.

Further, the substituted or unsubstituted hydrocarbon group in the general formula (5) to the general formula (8) may be directly bonded to the ring structure, or may be bonded via a linking group. Good.
As the linking group, for example, a divalent hydrocarbon group having 1 to 10 carbon atoms [for example, an alkylene group represented by — (CH ₂ ) _q — (wherein q is an integer of 1 to 10)]; oxygen Linking group containing an atom, nitrogen atom, sulfur atom or silicon atom [for example, carbonyl group (—CO—), oxycarbonyl group (—O (CO) —), sulfone group (—SO ₂ —), ether bond (— O-), thioether bond (-S-), imino group (-NH-), amide bond (-NHCO-, -CONH-), siloxane bond (-OSi-), 8-methyl-8-n-propoxycarbonyl Tetracyclo [4.4.0.12,5.17,10] -3-dodecene, 8-methyl-8-isopropoxycarbonyltetracyclo [4.4.0.12,12,5. 17,10] -3-dodecene, 8-fluoro-8-pentafluoroethyl-9,9-bis (trifluoromethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8,9-difluoro-8-heptafluoroiso-propyl-9-trifluoromethyltetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8-chloro-8,9,9-trifluorotetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8,9-dichloro-8,9-bis (trifluoromethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8- (2,2,2-trifluoroethoxycarbonyl) tetracyclo [4.4.0.12,5.17,10] -3-dodecene, 8-methyl-8- (2,2,2-trifluoroethoxycarbonyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene,

8- (4-biphenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5.17,10] -3-dodecene, 8- (4-biphenylcarbonyloxyethyl) tetracyclo [4.4.0.12 , 5.17,10] -3-dodecene, 8-methyl-8- (4-biphenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8- (2-biphenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8-methyl-8- (2-biphenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8- (3-biphenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8-methyl-8- (3-biphenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8- (1-naphthylcarbonyloxymethyl) tetracyclo [4.4.0.12,5.17,10] -3-dodecene, 8-methyl-8- (1-naphthyl) Carbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8- (2-naphthylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8-methyl-8- (2-naphthylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8- (9-anthracenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8-methyl-8- (9-anthracenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 1,2- (2H, 3H- [1,3] epicyclopenta) -1,2-dihydroacenaphthylene and Diels-Alder adduct of cyclopentadiene However, the specific monomer a is not limited to these compounds. Moreover, these compounds can be used as specific monomer a individually or in combination of 2 or more types.

Among these, compounds having at least one polar group are preferable in the molecule, in particular, in the general formula (5), a hydrocarbon group of R ₁ and R ₃ is C1-10 hydrogen atom or a carbon atom, R ₂ and R ₄ correspond to a hydrogen atom or a monovalent organic group, and at least one of R ₂ and R ₄ is a polar group other than a hydrogen atom and a hydrocarbon group, This is preferable because it improves the adhesiveness and adhesiveness.

  Here, the content of the polar group in the obtained specific polymer is determined by a desired function or the like required for the finally obtained specific retardation film, and is not particularly limited. The structural unit derived from the specific monomer a having a polar group in all structural units derived from the monomer a is usually 1 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, All the structural units derived from the specific monomer a may have a polar group.

Further, as the specific monomer d, in the general formula (7), it is possible that at least one of R ₂ and R ₄ has a polar group represented by the following general formula (9). This is preferable because the glass transition temperature and water absorption of the coalesce can be easily controlled.

Wherein (9), n is an integer of 0 to 5, R ₁₀ is a monovalent organic group. ]

Specific examples of the monovalent organic group represented by R ₁₀ in the general formula (9) include alkyl groups such as a methyl group, an ethyl group, and a propyl group; a phenyl group, a naphthyl group, an anthracenyl group, a biphenylyl group, and the like. Aryl group; in addition, monovalent groups having an aromatic ring such as fluorenes such as diphenylsulfone and tetrahydrofluorene, and a heterocyclic ring such as a furan ring and an imide ring.
Moreover, in General formula (9), n is an integer of 0-5, Preferably it is an integer of 0-2, More preferably, it is 0. The smaller the value of n, the higher the glass transition temperature of the specific polymer obtained, which is preferable. In particular, the specific monomer a having n of 0 is preferable in terms of easy synthesis.

Furthermore, the specific monomer d is preferably one in which an alkyl group is further bonded to the carbon atom to which the polar group represented by the general formula (9) is bonded in the general formula (7). It is possible to achieve a balance between heat resistance and water absorption of the specific polymer. Here, the number of carbon atoms of the alkyl group is preferably 1 to 5, more preferably 1 to 2, and particularly preferably 1.
Further, as the specific monomer d, those in which m is 1 and p is 0 in the general formula (7) are preferable in that a specific polymer having a high glass transition temperature is obtained.

As a specific example of the specific monomer e,
Bicyclo [2.2.1] hept-2-ene,
Tricyclo [5.2.1.02,6] dec-8-ene,
Tricyclo [6.2.1.02,7] undec-9-ene,
5-methylbicyclo [2.2.1] hept-2-ene,
5-ethylbicyclo [2.2.1] hept-2-ene,
5-methoxycarbonylbicyclo [2.2.1] hept-2-ene,
5-methyl-5-methoxycarbonylbicyclo [2.2.1] hept-2-ene,
5-phenoxycarbonylbicyclo [2.2.1] hept-2-ene,
5-methyl-5-phenoxycarbonylbicyclo [2.2.1] hept-2-ene,
5-cyanobicyclo [2.2.1] hept-2-ene,
5-ethylidenebicyclo [2.2.1] hept-2-ene,
5-phenylbicyclo [2.2.1] hept-2-ene,
5- (2-naphthyl) bicyclo [2.2.1] hept-2-ene (α-form and β-form),
5-fluorobicyclo [2.2.1] hept-2-ene,
5-fluoromethylbicyclo [2.2.1] hept-2-ene,
5-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5-pentafluoroethylbicyclo [2.2.1] hept-2-ene,

5,5-difluorobicyclo [2.2.1] hept-2-ene,
5,6-difluorobicyclo [2.2.1] hept-2-ene,
5,5-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5-methyl-5-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5,5,6-trifluorobicyclo [2.2.1] hept-2-ene,
5,5,6-tris (fluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5,6,6-tetrafluorobicyclo [2.2.1] hept-2-ene,
5,5,6,6-tetrakis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5-difluoro-6,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,6-difluoro-5,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5,6-trifluoro-5-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5-fluoro-5-pentafluoroethyl-6,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,6-difluoro-5-heptafluoro-iso-propyl-6-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5-chloro-5,6,6-trifluorobicyclo [2.2.1] hept-2-ene,
5,6-dichloro-5,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5,6-trifluoro-6-trifluoromethoxybicyclo [2.2.1] hept-2-ene,
5,5,6-trifluoro-6-heptafluoropropoxybicyclo [2.2.1] hept-2-ene,
5- (4-phenylphenyl) bicyclo [2.2.1] hept-2-ene,

4- (bicyclo [2.2.1] hept-5-en-2-yl) phenylsulfonylbenzene,
5- (4-biphenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (4-biphenylcarbonyloxyethyl) bicyclo [2.2.1] hept-2-ene,
5- (4-biphenylcarbonyloxypropyl) bicyclo [2.2.1] hept-2-ene,
5-methyl-5- (4-biphenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (2-biphenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (2-biphenylcarbonyloxyethyl) bicyclo [2.2.1] hept-2-ene,
5-methyl-5- (2-biphenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (3-biphenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (3-biphenylcarbonyloxyethyl) bicyclo [2.2.1] hept-2-ene,
5- (1-naphthylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (1-naphthylcarbonyloxyethyl) bicyclo [2.2.1] hept-2-ene,

5-methyl-5- (1-naphthylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (2-naphthylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (2-naphthylcarbonyloxyethyl) bicyclo [2.2.1] hept-2-ene,
5-methyl-5- (2-naphthylcarbonyloxymethyl) methylbicyclo [2.2.1] hept-2-ene,
5- (9-anthracenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (9-anthracenylcarbonyloxyethyl) bicyclo [2.2.1] hept-2-ene,
5-methyl-5- (9-anthracenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
Examples thereof include Diels-Alder adducts of acenaphthylene and cyclopentadiene, but the specific monomer e is not limited to these compounds. These compounds can be used as the specific monomer e alone or in combination of two or more.

The specific polymer obtained by copolymerizing the specific monomer d and the specific monomer e is copolymerized with other copolymerizable monomers other than the specific monomer d and the specific monomer e. It may be made.
Examples of other copolymerizable monomers include cycloolefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, and dicyclopentadiene. The number of carbon atoms of the cycloolefin is preferably 4-20, and more preferably 5-12. In addition, specific unit amounts in the presence of unsaturated hydrocarbon-based polymers having an olefinically unsaturated bond in the main chain, such as polybutadiene, polyisoprene, styrene-butadiene copolymer, ethylene-nonconjugated diene copolymer, polynorbornene, etc. The specific monomer b may be polymerized as required, and the specific polymer thus obtained is useful as a raw material for a resin having high impact resistance.

The specific viscosity (η _inh ) of the specific polymer measured in chloroform at 30 ° C. is preferably 0.2 to 5 dl / g. More preferably, it is 0.3-4 dl / g, Most preferably, it is 0.5-3 dl / g. If it exceeds 5 dl / g, the solution viscosity becomes too high and the processability may be deteriorated, and if it is less than 0.2 dl / g, the film strength may be lowered.

As the molecular weight of the specific polymer, the polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is usually 8,000 to 1,000,000, preferably 10,000 to 500. , More preferably 20,000 to 100,000, particularly preferably 30,000 to 100,000, and the weight average molecular weight (Mw) is usually 20,000 to 3,000,000, preferably 30 , 1,000 to 1,000,000, more preferably 40,000 to 500,000, particularly preferably 40,000 to 300,000.
The molecular weight distribution of the specific polymer is such that the above-mentioned Mw / Mn is usually 1.5 to 10, preferably 2 to 8, more preferably 2.5 to 5, particularly preferably 2.5 to 4.5. .

  The glass transition temperature (Tg) of the specific polymer may be changed as appropriate by adjusting the type of the structural unit a and the structural unit b of the specific polymer, the ratio of the structural unit a and the structural unit b, or the addition of an additive. However, it is usually 100 to 250 ° C, preferably 110 to 200 ° C, more preferably 120 to 180 ° C. When Tg is 100 ° C. or lower, the heat distortion temperature is lowered, which may cause a problem in heat resistance, and the optical properties of the finally obtained film may be greatly affected by the temperature. Moreover, when Tg is 250 ° C. or higher, there is a high possibility that the thermoplastic norbornene-based resin is thermally deteriorated when heated to the vicinity of Tg for processing such as stretching.

  In the specific polymer having the structural unit d and the structural unit e, the ratio (d / e) of the structural unit d to the structural unit e is preferably d / e = 95/5 to 5/95 in molar ratio, More preferably, it is 95 / 5-60 / 40. If the proportion of the structural unit d is larger than the above range, the effect of improving toughness and desired optical properties may not be expected. Conversely, if the proportion of the structural unit d is smaller than the above range, the glass transition temperature is lowered and the heat resistance is decreased. May cause problems.

  Furthermore, in the specific polymer having the structural unit d and the structural unit e, it is preferable that the ratio (composition ratio) between the structural unit d and the structural unit e in the polymer is small in the entire molecular weight distribution range. Specifically, the composition ratio at an arbitrary molecular weight is within ± 50%, preferably within ± 30%, more preferably relative to the ratio of the specific monomer a and the specific monomer e subjected to the polymerization reaction. Can be obtained within a variation range of ± 20%, whereby a more uniform specific retardation film can be obtained. Further, by being within such a range, it becomes possible to obtain a more uniform retardation when stretched and oriented.

  Below, after ring-opening copolymerization of the specific monomer d and, if necessary, the specific monomer e or other copolymerizable monomer, or after ring-opening copolymerization of these monomers The conditions for producing a specific polymer obtained by hydrogenating the obtained ring-opening copolymer will be described.

(Ring-opening polymerization catalyst):
The ring-opening polymerization reaction of the monomer is performed in the presence of a metathesis catalyst.
This metathesis catalyst comprises (a) at least one selected from W, Mo and Re compounds, (b) Deming periodic table group IA elements (for example, Li, Na, K, etc.), IIA group elements (for example, Mg, Ca, etc.), Group IIB elements (eg, Zn, Cd, Hg, etc.), Group IIIB elements (eg, B, Al, etc.), Group IVA elements (eg, Ti, Zr, etc.) or Group IVB elements (eg, Si, Sn, etc.) Pb or the like), and a catalyst comprising a combination with at least one selected from those having at least one element-carbon bond or element-hydrogen bond. In this case, in order to increase the activity of the catalyst, an additive (c) described later may be added.

Representative examples of W, Mo or Re compounds suitable as the component (a) include compounds described in JP-A-1-240517 such as WCl ₆ , MoCl ₅ and ReOCl ₃ .
(B) Specific examples of the _{component, n-C 4 H 9 Li} , (C 2 H 5) 3 Al, (C 2 H 5) 2 AlCl, (C 2 H 5) 1.5 AlCl 1.5, (C 2 H ₅₎ AlCl _2, mention may be made of methyl alumoxane, LiH, etc., compounds described in JP-a-1-240517.
As typical examples of the component (c), alcohols, aldehydes, ketones, amines and the like can be preferably used, and compounds described in JP-A-1-240517 can be further used.

The amount of the metathesis catalyst used is the molar ratio of the component (a) to the specific monomer d and the specific monomer e (hereinafter referred to as “specific monomer”). : The specific monomer is usually in the range of 1: 500 to 1: 50000, preferably in the range of 1: 1000 to 1: 10000.
The ratio of the component (a) to the component (b) is such that “(a) :( b)” is 1: 1 to 1:50, preferably 1: 2 to 1:30 in terms of metal atomic ratio.
The ratio of the component (a) to the component (c) is such that the molar ratio “(c) :( a)” is 0.005: 1 to 15: 1, preferably 0.05: 1 to 7: 1. It is.

(Molecular weight regulator)
The molecular weight of the specific polymer can be adjusted depending on the polymerization temperature, the type of catalyst, and the type of solvent. In the present invention, it is preferable to adjust the molecular weight by allowing a molecular weight regulator to coexist in the reaction system. Suitable molecular weight regulators include, for example, α-olefins such as ethylene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and styrene. Of these, 1-butene and 1-hexene are preferred.
These molecular weight regulators can be used alone or in combination of two or more.
The amount of the molecular weight regulator used is 0.005 to 0.6 mol, preferably 0.02 to 0.5 mol, per 1 mol of the specific monomer subjected to the polymerization reaction.

(Solvent for ring-opening polymerization reaction)
Examples of the solvent used in the ring-opening polymerization reaction include alkanes such as pentane, hexane, heptane, octane, nonane, decane; cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin, norbornane; benzene, toluene, xylene , Ethylbenzene, cumene and other aromatic hydrocarbons; chlorobutane, bromohexane, methylene chloride, dichloroethane, hexamethylene dibromide, chlorobenzene, chloroform, tetrachloroethylene and other halogenated hydrocarbon compounds; ethyl acetate, n-butyl acetate, acetic acid Saturated carboxylic acid esters such as iso-butyl and methyl propionate; and ethers such as dimethoxyethane, dibutyl ether, and tetrahydrofuran, which are used alone There can be used in combination of two or more kinds. Among these, the above aromatic hydrocarbons are preferable.
The amount of the solvent used is such that the solvent: specific monomer (mass ratio) is usually in an amount of 1: 1 to 10: 1, preferably in an amount of 1: 1 to 5: 1.

(Hydrogenation):
The ring-opening copolymer obtained by the above ring-opening polymerization can be used as a specific polymer as it is, but a hydrogenated product in which the olefinically unsaturated bond remaining in the ring-opening copolymer is hydrogenated and It is preferable to do.

  This hydrogenated product has excellent thermal stability, and its characteristics are not easily deteriorated by heating during film formation processing, stretching processing, or use as a product. In such a hydrogenated product, the hydrogenation rate with respect to the olefinically unsaturated bond is 50% or more, preferably 70% or more, more preferably 90% or more, and particularly preferably 98% or more. Moreover, when the ring-opening copolymer used for hydrogenation has an aromatic ring in the molecule, it is preferable that the aromatic ring is not substantially hydrogenated after hydrogenation.

  In the hydrogenation reaction, a hydrogenation catalyst is added to an ordinary method, that is, a solution of a ring-opening copolymer, and hydrogen gas at normal pressure to 300 atm, preferably 3 to 200 atm, is added to 0 to 200 ° C., preferably It is performed by operating at 20 to 180 ° C.

As a hydrogenation catalyst, what is used for the hydrogenation reaction of a normal olefinic compound can be used. As this hydrogenation catalyst, a heterogeneous catalyst and a homogeneous catalyst are known. In addition, when hydrogenating a ring-opening polymer having a substituent having an aromatic ring in the molecule, it is preferable to select conditions under which the unsaturated bond of the aromatic ring is not substantially hydrogenated.
Examples of the heterogeneous catalyst include solid catalysts in which noble metals such as palladium, platinum, nickel, rhodium, and ruthenium are supported on a carrier such as carbon, silica, alumina, and titania. In addition, homogeneous catalysts include nickel naphthenate / triethylaluminum, nickel acetylacetonate / triethylaluminum, cobalt octenoate / n-butyllithium, titanocene dichloride / diethylaluminum monochloride, rhodium acetate, chlorotris (triphenylphosphine) rhodium. Dichlorotris (triphenylphosphine) ruthenium, chlorohydrocarbonyltris (triphenylphosphine) ruthenium, dichlorocarbonyltris (triphenylphosphine) ruthenium, and the like. The form of the catalyst may be powder or granular.
These hydrogenation catalysts are used in such a ratio that the ring-opening polymer: hydrogenation catalyst (mass ratio) is 1: 1 × 10 ⁻⁶ to 1: 2.

(Film production)
In the present invention, a thermoplastic norbornene resin made of a specific polymer can be formed into a film by a melt molding method or a solution casting method (solvent casting method), etc., but the thickness is highly uniform and the surface smoothness is high. It is preferable to use a solvent casting method in that a pre-processed film can be obtained. As the solvent casting method, for example, a thermoplastic norbornene-based resin is dissolved or dispersed in a solvent to prepare a film-forming solution containing the thermoplastic norbornene-based resin at an appropriate concentration. For example, a method of pouring or coating on a suitable carrier, drying it, and then peeling it from the carrier.

  When the thermoplastic norbornene resin is dissolved or dispersed in a solvent, the concentration of the thermoplastic norbornene resin is usually 0.1 to 90% by mass, preferably 1 to 50% by mass, and more preferably 10 to 35% by mass. %. When this concentration is less than 0.1% by mass, it may be difficult to obtain a pre-processed film having a required thickness, and when the solvent is removed by drying, the solvent may be evaporated. Accordingly, foaming or the like is likely to occur, and it may be difficult to obtain a pre-processed film having good surface smoothness. On the other hand, when the concentration exceeds 90% by mass, the solution viscosity of the film-forming solution becomes too high, and it may be difficult to obtain a film having a uniform thickness and surface condition.

  The viscosity of the film-forming solution is usually 1 to 1,000,000 (mPa · s), preferably 10 to 100,000 (mPa · s), more preferably 100 to 50,000 (mPa · s) at room temperature. s), particularly preferably 1000 to 40,000 (mPa · s).

  Solvents used for the preparation of the film forming liquid include aromatic solvents such as benzene, toluene and xylene, cellosolve solvents such as methyl cellosolve, ethyl cellosolve and 1-methoxy-2-propanol, diacetone alcohol, acetone and cyclohexanone. Ketone solvents such as methyl ethyl ketone, 4-methyl-2-pentanone, cyclohexanone, ethyl cyclohexanone and 1,2-dimethylcyclohexane, ester solvents such as methyl lactate and ethyl lactate, 2,2,3,3-tetrafluoro- Examples thereof include halogen-containing solvents such as 1-propanol, methylene chloride and chloroform, ether solvents such as tetrahydrofuran and dioxane, and alcohol solvents such as 1-pentanol and 1-butanol.

  In addition to the above solvents, the SP value (solubility parameter) is usually 10-30 (MPa1 / 2), preferably 10-25 (MPa1 / 2), more preferably 15-25 (MPa1 / 2), especially When a solvent in the range of preferably 15 to 20 (MPa1 / 2) is used, a processed film having good surface uniformity and optical properties can be obtained.

  Said solvent can be used individually or in combination of 2 or more types. When two or more solvents are used in combination, the SP value range of the obtained mixed solvent is preferably within the above range. At this time, the value of the SP value of the mixed solvent can be determined from the mass ratio of each solvent constituting the mixed solvent. For example, in the mixed solvent obtained from two types of solvents, the SP value of each solvent and their values When the mass fraction is W1 and W2, and the SP value is SP1 and SP2, the SP value of the mixed solvent can be calculated by the formula: SP value = W1 · SP1 + W2 · SP2.

In the case of using a mixed solvent as a solvent in the film forming liquid, it is possible to obtain a pre-processed film having a light diffusion function by combining a good solvent and a poor solvent with respect to the thermoplastic norbornene resin. it can. Specifically, when the SP value of the thermoplastic norbornene resin is SPx, the SP value of the good solvent of the thermoplastic norbornene resin is SPy, and the SP value of the poor solvent of the thermoplastic norbornene resin is SPz, SPx and SPy Is preferably 7 or less, more preferably 5 or less, particularly preferably 3 or less, and the difference between SPx and SPz is preferably 7 or more, more preferably 8 or more, and particularly preferably 9 or more. And the difference between SPz is preferably 3 or more, more preferably 5 or more, and even more preferably 7 or more, so that a light diffusion function can be imparted to the resulting pre-processed film. The specific retardation film can have a light diffusion function.
The proportion of the poor solvent in the mixed solvent is preferably 50% by mass or less, more preferably 30% by mass or less, particularly preferably 15% by mass or less, and most preferably 10% by mass or less. The difference between the boiling point of the poor solvent and the boiling point of the good solvent is preferably 1 ° C. or higher, more preferably 5 ° C. or higher, particularly preferably 10 ° C. or higher, and most preferably 20 ° C. or higher. It is preferably higher than the boiling point of the good solvent.

The temperature at which the thermoplastic norbornene-based resin is dissolved or dispersed in the solvent may be room temperature or high, and by sufficiently stirring, a film-forming solution in which the thermoplastic norbornene-based resin is uniformly dissolved or dispersed can be obtained.
Moreover, coloring agents, such as a dye and a pigment, can be suitably added to a film formation liquid as needed, and, thereby, the colored film before a process can be obtained.
Moreover, you may add a leveling agent to a film formation liquid for the purpose of improving the surface smoothness of the film before a process obtained. As such leveling agents, various ones can be used as long as they are general, and specific examples thereof include fluorine-based nonionic surfactants, special acrylic resin-based leveling agents, silicone-based leveling agents, and the like. .

As a carrier for forming the liquid layer of the film forming liquid, a metal drum, a steel belt, a polyester film made of polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), a polytetrafluoroethylene belt, or the like may be used. it can. As a method for applying the film forming liquid, a method using a die or a coater, a spray method, a brush coating method, a roll coating method, a spin coating method, a dipping method, or the like can be used.
Moreover, the thickness and surface smoothness of the pre-processed film obtained can also be controlled by repeatedly applying the film forming liquid.

When a polyester film is used as the carrier, a surface-treated film may be used.
As a surface treatment method, a hydrophilic treatment method generally used, for example, a method of laminating an acrylic resin or a sulfonate group-containing resin by coating or lamination, or a film surface hydrophilicity by corona discharge treatment or the like. The method etc. which improve are mentioned.

  In the solvent casting method, a specific method for removing the solvent in the liquid layer is not particularly limited, and a commonly used drying treatment method, for example, a method of passing through a drying furnace by a large number of rollers is used. However, if bubbles are generated as the solvent evaporates in the drying process, the properties of the specific retardation film finally obtained are significantly deteriorated. To avoid this, the drying process is performed in two or more stages. It is preferable to control the temperature or the air volume in each step.

  The amount of residual solvent in the pre-processed film thus obtained is usually 10% by mass or less, preferably 5% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less. Here, when the amount of residual solvent in the film before processing exceeds 10% by mass, the dimensional change with time is large when the specific retardation film obtained by stretching the film before processing is actually used. It is not preferable. Further, the residual solvent lowers the glass transition temperature and lowers the heat resistance, which is not preferable.

  Moreover, in order to perform the extending | stretching process mentioned later suitably, it may be necessary to adjust the residual solvent amount in the film before a process suitably within the said range. Specifically, the amount of residual solvent in the film before processing is usually 10 to 0.1% by mass, preferably 5 to 0.1% by mass, in order to stably and uniformly express the phase difference in the film by stretching and orientation treatment. %, More preferably 1 to 0.1% by mass. By leaving a trace amount of solvent in the pre-processed film, the stretching and orientation treatment may be facilitated or the retardation may be easily controlled.

In the present invention, the thickness of the film before processing is usually 1 to 500 μm (1,000 to 500,000 nm), preferably 1 to 300 μm (1,000 to 300,000 nm), more preferably 1 to 200 μm (1,000). ˜200,000), most preferably 1 to 100 μm (1,000 to 100,000 nm). When this thickness is less than 1 μm, it becomes difficult to substantially handle the unprocessed film. On the other hand, when the thickness is 500 μm or more, when the pre-processed film is wound up in a roll shape, a so-called “wrapping” may be attached and handling in post-processing or the like may be difficult.
The thickness distribution of the film before processing is usually within ± 20%, preferably within ± 10%, more preferably within ± 5%, particularly preferably within ± 3% with respect to the average value. The thickness variation per cm is usually 10% or less, preferably 5% or less, more preferably 1% or less, and particularly preferably 0.5% or less. By controlling the thickness distribution of the unprocessed film within the above range, it is possible to prevent the occurrence of retardation unevenness when the stretching and orientation treatment is performed on the unprocessed film.

Specific examples of the stretching method for producing the specific retardation film include known uniaxial stretching methods and biaxial stretching methods.
That is, by the horizontal uniaxial stretching method by the tenter method, the inter-roll compression stretching method, the longitudinal uniaxial stretching method using two sets of rolls having different circumferences, or the biaxial stretching method combining the horizontal uniaxial and the longitudinal uniaxial, the inflation method A stretching method or the like can be used.
In the case of the uniaxial stretching method, the stretching speed is usually 1 to 5,000% / min, preferably 50 to 1,000% / min, more preferably 100 to 1,000% / min, particularly preferably. Is 100-500% / min.
In the case of the biaxial stretching method, stretching may be performed in two directions at the same time, or the stretching may be performed in a direction different from the first stretching direction after uniaxial stretching. At this time, the intersecting angle of the two stretching axes for controlling the shape of the refractive index ellipsoid of the stretched film is not particularly limited because it is determined by desired characteristics, but is usually in the range of 120 to 60 degrees. is there. The stretching speed may be the same or different in each stretching direction, and is usually 1 to 5,000% / min, preferably 50 to 1,000% / min, and more preferably 100 to 1,000% / min, particularly preferably 100 to 500% / min.

The treatment temperature in the stretching orientation treatment is not particularly limited, but is usually Tg ± 30 ° C., preferably Tg ± 15 ° C., more preferably Tg, based on the glass transition temperature Tg of the thermoplastic norbornene resin used. It is in the range of −5 ° C. to Tg + 15 ° C. By setting the treatment temperature within the above range, it is possible to suppress the occurrence of phase difference unevenness, and it is preferable because the control of the refractive index ellipsoid becomes easy.
The draw ratio is not particularly limited because it is determined by desired properties, but is usually 1.01 to 10 times, preferably 1.03 to 5 times, and more preferably 1.03 to 3 times. When the draw ratio is 10 times or more, it may be difficult to control the phase difference.

  The stretched film may be cooled as it is, but is heat set by holding it in a temperature atmosphere of Tg-20 ° C. to Tg for at least 10 seconds, preferably 30 seconds to 60 minutes, more preferably 1 minute to 60 minutes. It is preferable to do. As a result, a stable retardation film can be obtained with little change over time in the retardation of transmitted light.

The dimensional shrinkage due to heating of the specific retardation film is usually 10% or less, preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less when heated at 100 ° C. for 500 hours. .
In order to make the dimensional shrinkage rate within the above range, in addition to the selection of the specific monomer a, the specific monomer b or other copolymerizable monomer, which is a raw material of the thermoplastic norbornene resin, cast It can be controlled by the method and the stretching method.
In addition, the dimensional shrinkage ratio due to heating of the pre-processed film in a state where the stretch orientation treatment has not been performed is usually 5% or less, preferably 3% or less, more preferably 1% when heating at 100 ° C. is performed for 500 hours. Hereinafter, it is particularly preferably 0.5% or less.

  The film stretched as described above gives a phase difference to transmitted light due to the orientation of molecules by stretching. This phase difference is determined by the type of thermoplastic norbornene resin used as a raw material, It can be controlled by adjusting the magnification, the stretching temperature or the thickness of the film before stretching (film before processing). For example, as for the draw ratio, even if the film has the same thickness before drawing, the absolute value of the retardation of transmitted light tends to increase as the draw ratio increases. A film that imparts a retardation to transmitted light can be obtained. In addition, as for the thickness of the film before stretching (film before processing), even if the stretching ratio is the same, the larger the thickness of the film before stretching, the larger the absolute value of the phase difference given to transmitted light tends to increase. By changing the thickness of the film before stretching, a retardation film that imparts a desired retardation to transmitted light can be obtained. In addition, with respect to the stretching treatment temperature, the lower the stretching temperature, the greater the absolute value of the retardation of the transmitted light. Therefore, by changing the stretching temperature, a retardation film that gives the desired retardation to the transmitted light is obtained. be able to.

  Moreover, in order to adjust the thickness of a specific phase difference film, it can control by adjusting the thickness of a film before a process, a draw ratio, etc. Specifically, for example, the thickness of the retardation film can be reduced by reducing the thickness of the film before processing or increasing the draw ratio.

In such a specific retardation film, the number of bright spots when converted per 1 m ² on the film surface is 10 or less, preferably 7 or less, more preferably 5 or less, and particularly preferably 3 Hereinafter, it is most preferably 0 or 1.
Here, the “bright spot” is a partial light leakage confirmed with the naked eye when a specific retardation film is sandwiched between polarizing plates in a crossed Nicol state, and usually has an outer diameter of 1 μm or more (circular shape). If it is, the diameter is measured, and if it is other shape, the length in the longitudinal direction is measured. Of course, depending on the required performance, a smaller one may be measured as a bright spot. Such bright spots are considered to be caused by partial unevenness of the phase difference in a minute region. That is, when foreign matter, bubbles, etc. are present in the film before processing, even if they are of a size that cannot be confirmed with the naked eye, stress is concentrated on the portion where foreign matter, bubbles, etc. are present when stretched, The phase difference in the stress concentrated portion may be different from the phase difference in the peripheral portion, and it is considered that light leaks due to the difference in the phase difference.

In the specific retardation film, the number of foreign matters when converted to 1 m ² on the film surface is preferably 10 or less, more preferably 5 or less, particularly preferably 3 or less, and most preferably 0. Or it is set to 1.
The term “foreign matter” as used herein substantially prevents light transmission when light is transmitted through the specific retardation film. When such a foreign substance is present in the specific retardation film, the transmitted light intensity is affected, and when used in a liquid crystal display element or the like, there is a risk of pixel omission or deterioration of characteristics.
The size of the foreign matter to be measured is usually an outer diameter of 1 μm or more (the diameter of a circular one, the length in the longitudinal direction of other shapes), but depending on the required performance Something smaller than this may be measured as a foreign object.

[Negative intrinsic birefringence additive]
Next, the negative intrinsic birefringent additive used in the present invention will be described.
In the present specification, the “negative intrinsic birefringent additive” means a material having a characteristic of exhibiting optically negative uniaxiality when the additive is oriented with uniaxial order. For example, when light is incident on a layer in which the material has a uniaxial orientation, a material in which the refractive index of light in the orientation direction is smaller than the refractive index of light in the direction perpendicular to the orientation direction is It is a negative intrinsic birefringence value additive.

  In particular, in the present invention, this “negative intrinsic birefringent additive” is aligned with the orientation of the polymer resin as a matrix, and exhibits the greatest polarizability anisotropy in a direction substantially perpendicular to the orientation direction. Here, the orientation direction of the additive molecule does not have to be exactly the same as the orientation of the polymer resin, and it is important to have the greatest polarizability anisotropy in a direction substantially perpendicular to the orientation direction of the polymer chain. It is. The orientation direction of the substituent having a large polarizability anisotropy is classified into two types, when oriented in the film in-plane direction while being orthogonal to the orientation direction of the polymer resin, and when oriented in the film thickness direction while being orthogonal. Broadly divided. In the optical film of the present invention, it is preferable that in-plane retardation has a reverse dispersion characteristic and the film thickness direction retardation has a forward dispersion characteristic. For that purpose, it is preferable that the substituent having a large polarizability anisotropy is oriented in the in-plane direction of the film while being orthogonal to the orientation direction of the polymer resin. In the present invention, the orientation direction of the polymer main chain and additive molecules can be measured using polarized Raman spectroscopy, polarized IR, etc., and the polarizability anisotropy of these can also be measured separately. The relative relationship between the two agents can be easily grasped.

As the negative intrinsic birefringent additive of the present invention, those having a large wavelength dispersion of the intrinsic birefringence value are preferable. Specifically, the intrinsic birefringence value (Δn) at a wavelength of 450 nm and a wavelength of 550 nm, respectively, When Δn (450) and Δn (550) are set, it is preferably selected from those satisfying the following relational expression.
| Δn (450) / Δn (550) |> 1.02

Furthermore, it is more preferable that it is selected from those satisfying the following relational expression.
| Δn (450) / Δn (550) |> 1.05
The larger value of | Δn (450) / Δn (550) | is preferable, but in the case of resin, it is generally 2.0 or less.

  The structure and molecular weight are not limited as long as the above conditions are satisfied, but a compound having high compatibility with the polymer resin and large polarizability anisotropy is preferable. The additive preferably has an absorption maximum in the wavelength region of 200 nm to 400 nm, more preferably has an absorption maximum in the wavelength region of 200 nm to 350 nm, and has an absorption maximum in the wavelength region of 250 nm to 350 nm. Particularly preferred. Specific examples of such additives include polystyrene, polystyrene-based polymers (copolymers of styrene and / or styrene derivatives and other monomers), polyacrylonitrile-based polymers, polymethyl methacrylate-based polymers, polycarbonate-based polymers, Cellulose ester polymers, or multi-component (binary, ternary, etc.) copolymer polymers thereof, styrene oligomers, benzyl methacrylate oligomers, cellulose ester oligomers (excluding those having a positive intrinsic birefringence value), and the like. . These may be used individually by 1 type and may use 2 or more types together.

  Examples of the polystyrene-based polymer include copolymers of styrene and / or styrene derivatives and other monomers, among which styrene and / or styrene derivatives and acrylonitrile, maleic anhydride, methyl methacrylate, and butadiene are selected. A copolymer with at least one kind is preferred.

  In this invention, among these, at least one selected from polystyrene, polystyrene-based polymer, polyacrylonitrile-based polymer, polymethylmethacrylate-based polymer is preferable, among these, from the viewpoint of high birefringence expression, Polystyrene and polystyrene-based polymers are more preferable, and a copolymer of styrene and / or a styrene derivative and maleic anhydride is particularly preferable in terms of high heat resistance. However, the present invention is not limited by the above specific examples.

It is preferred that the content is 0.1 to 20 mass parts relative to 100 parts by weight of polymeric resin of negative intrinsic birefringence additives of the invention described above, more preferably 1 to 15 mass parts, 1 10 mass parts is more preferable.
The negative intrinsic birefringence additive of the present invention is added to the polymer resin solution (dope) after being dissolved in an organic solvent such as alcohol, methylene chloride or dioxolane, or added directly to the dope composition. May be.

[Retardation]
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 with a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments). Rth (λ) is the above-mentioned Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotating axis) (if there is no slow axis, it is arbitrary in the film plane) The light is incident at a wavelength of λ nm from the inclined direction in steps of 10 degrees from the normal direction to 50 degrees on one side with respect to the film normal direction of KOBRA 21ADH or WR calculates based on the measured retardation value, the assumed average refractive index, and the input film thickness value. The retardation value is measured from any two directions with the slow axis as the tilt axis (rotary axis) (in the absence of the slow axis, the arbitrary direction in the film plane is the rotational axis), and the value Rth can also be calculated from the following formula (1) and formula (2) based on the assumed value of the average refractive index and the input film thickness value. Here, as the assumed value of the average refractive index, values in the polymer handbook (JOHN WILEY & SONS, INC) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of the 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 these assumed values of average refractive index and film thickness, KOBRA 21ADH or WR calculates nx, ny, and nz. From this calculated nx, ny, and nz, Nz = (nx−nz) / (nx−ny) is further calculated.

  The above Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction.

The Re of the cellulose acylate film of the present invention is preferably 20 to 200 nm, more preferably 25 to 100 nm, and most preferably 30 to 80 nm. Rth is preferably 70 nm to 400 nm, more preferably 90 nm to 350 nm, and most preferably 110 nm to 320 nm.
The Rth / Re ratio is preferably 1 or more and 10 or less, more preferably 2 or more and 9 or less.

The variation in the width direction of Re and Rth is preferably within 5%.
The angle formed between the slow axis of the film and the casting direction is preferably 85 ° or more and 95 ° or less, and the fluctuation range of the angle in the width direction is preferably 5 ° or less.

[Surface treatment of cellulose acylate film]
The cellulose acylate film is preferably subjected to a surface treatment. Specific examples include corona discharge treatment, glow discharge treatment, flame treatment, acid treatment, alkali treatment, and ultraviolet irradiation treatment. It is also preferable to provide an undercoat layer as described in JP-A-7-333433.
When used as a transparent protective film for a polarizing plate, it is particularly preferable to carry out acid treatment or alkali treatment, that is, saponification treatment for cellulose acylate, from the viewpoint of adhesiveness with a polarizer.
The surface energy is preferably 55 mN / m or more, and more preferably 60 mN / m or more and 75 mN / m or less.

Hereinafter, the alkali saponification treatment is specifically described as an example.
The alkali saponification treatment of the cellulose acylate film is preferably performed in a cycle in which the film surface is immersed in an alkaline solution, neutralized with an acidic solution, washed with water and dried.
Examples of the alkaline solution include potassium hydroxide solution and sodium hydroxide solution, and the prescribed concentration of hydroxide ions is preferably in the range of 0.1 to 3.0N, and in the range of 0.5 to 2.0N. More preferably it is. The alkaline solution temperature is preferably in the range of room temperature to 90 ° C, and more preferably in the range of 40 to 70 ° C.

The surface energy of a solid can be determined by a contact angle method, a wet heat method, and an adsorption method as described in “Basics and Applications of Wetting” (issued by Realize 1989.12.10). In the case of the cellulose acylate film of the present invention, it is preferable to use a contact angle method.
Specifically, two kinds of solutions having known surface energies are dropped on a cellulose acylate film, and at the intersection of the surface of the droplet and the surface of the film, the angle formed between the tangent line drawn on the droplet and the film surface, The surface angle of the film can be calculated by defining the angle containing the droplet as the contact angle.

[Moisture content of cellulose acylate film]
The water absorption rate of the cellulose acylate film can be evaluated by measuring the equilibrium water content at a constant temperature and humidity. The equilibrium moisture content is calculated by measuring the moisture content of the sample that has reached equilibrium after being left at a constant temperature and humidity for 24 hours by the Karl Fischer method, and dividing the moisture content (g) by the sample mass (g). .
The equilibrium water content of the cellulose acylate film of the present invention at 25 ° C. and 80% is preferably 3% by mass or less, more preferably 2.5% by mass or less, and most preferably 2% by mass or less.

[Moisture permeability]
The moisture permeability is calculated as the amount of moisture (g) that evaporates in 24 hours per 1 m ^{2 of} area by measuring the moisture permeability of each sample in accordance with the method described in JIS Z 0208.
The moisture permeability of the cellulose acylate film can be adjusted by various methods.
The moisture permeability can be reduced by adding a hydrophobic compound to the cellulose acylate film and reducing the water absorption rate of the cellulose acylate film.
The moisture permeability of the cellulose acylate film of the present invention measured by the method of JIS Z 0208, Condition A is preferably 20 g / m ² or more and 250 g / m ² or less, more preferably 40 g / m ² or more and 225 g / m ² or less, 100 g / m ² or more and 200 g / m ² or less is most preferable.

[Hygroscopic expansion coefficient]
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.
In order to prevent a frame-like transmittance increase, the hygroscopic expansion coefficient of the cellulose acylate film is preferably 30 × 10 ⁻⁵ /% RH or less, and is preferably 15 × 10 ⁻⁵ /% RH or less. More preferably, it is most preferably 10 × 10 ⁻⁵ /% RH or less. Further, the hygroscopic expansion coefficient is preferably small, but usually a value of 1.0 × 10 ⁻⁵ /% RH or more.
The method for measuring the hygroscopic expansion coefficient is shown below. 5 mm wide from the produced polymer film (retardation plate). A sample having a length of 20 mm was cut out, one end was fixed, and the sample was hung in an atmosphere of 25 ° C. and 20% RH (R0). A weight of 0.5 g was hung from the other end and left for 10 minutes to measure the length (L0). Next, the length (L1) was measured while maintaining the temperature at 25 ° C. and the humidity at 80% RH (R1). The hygroscopic expansion coefficient was calculated by the following equation. The measurement was performed 10 samples for the same sample, and the average value was adopted.
Hygroscopic expansion coefficient [/% RH] = {(L1-L0) / L0} / (R1-R0)

In order to reduce the dimensional change due to moisture absorption, it is preferable to reduce the amount of residual solvent during film formation to reduce the free volume in the polymer film.
A general method for reducing the residual solvent is to dry at a high temperature for a long time. However, if the time is too long, the productivity is naturally lowered. Therefore, the amount of residual solvent with respect to the cellulose acylate film is preferably in the range of 0.01 to 1% by mass, more preferably in the range of 0.02 to 0.07% by mass, and 0.03 to 0%. The most preferable range is 0.05 mass%.
By controlling the amount of the residual solvent, a polarizing plate having optical compensation ability can be produced at low cost with high productivity.

The amount of residual solvent was measured using a gas chromatograph (GC18A, manufactured by Shimadzu Corporation) by dissolving a certain amount of sample in chloroform.
In the solution casting method, a film is produced using a solution (dope) in which a polymer material is dissolved in an organic solvent. As described later, drying by the solution casting method is largely divided into drying on the drum (or band) surface and drying during film conveyance. When drying on the drum (or band) surface, it is preferable to dry slowly at a temperature that does not exceed the boiling point of the solvent being used (when the boiling point is exceeded, bubbles are formed). Moreover, it is preferable to dry at the time of film conveyance at the glass transition point of polymer material ± 30 ° C., more preferably ± 20 ° C.

Further, as another method for reducing the dimensional change due to moisture absorption, it is preferable to add a compound having a hydrophobic group. The material having a hydrophobic group is not particularly limited as long as it is a material having a hydrophobic group such as an alkyl group or a phenyl group in the molecule. Among the plasticizers and deterioration inhibitors added to the cellulose acylate film, In particular, the corresponding material is preferably used. Examples of these preferable materials include triphenyl phosphate (TPP) and tribenzylamine (TBA).
The addition amount of the compound having a hydrophobic group is preferably in the range of 0.01 to 30% by mass, more preferably in the range of 0.1 to 20% by mass with respect to the solution (dope) to be adjusted. preferable.

[Dimension change rate]
The dimensional change rate of the cellulose acylate film can be calculated by the following formula by measuring the dimensional change before and after aging at a constant temperature with a pin gauge.
Dimensional change rate (%) = [(L2-L1) / L1] × 100
In the formula, L1 represents a dimension before aging, and L2 represents a dimension after aging.

  The dimensional change rate of the cellulose acylate film of the present invention at 90 ° C. for 24 hours is preferably −0.5% to 0.5%, more preferably −0.3% to 0.3%, 0.2% or more and 0.2% or less is most preferable.

[Elastic modulus of cellulose acylate film]
The elastic modulus of the cellulose acylate film can be determined by a tensile test. In the cellulose acylate film of the present invention, at least one direction in the width direction or the casting direction is preferably 1.0 GPa or more and 6.0 GPa or less, more preferably 2.0 GPa or more and 5.5 GPa or less, and more preferably 2.5 GPa or more and 5.0 GPa or less. Is most preferred.

[Photoelasticity]
The photoelastic coefficient of the cellulose acylate film of the present invention is preferably 60 × 10 ⁻⁸ cm ² / N or less, and more preferably 20 × 10 ⁻⁸ cm ² . The photoelastic coefficient can be obtained by an ellipsometer.

(Film surface treatment)
The stretched polymer film of the present invention has a hydrophilic surface to ensure adhesion between the polarizer and the optically anisotropic layer or the alignment layer provided between the optically anisotropic layer and the stretched polymer film of the present invention. Preferably it has been treated.
As the surface treatment method, for example, a method of providing an adhesive layer described in JP-A No. 2000-24167, JP-A No. 10-130402, JP-A No. 2002-148436, JP-A No. 2002-90546, JP-A No. 2001-350017, Further, hydrophilicity can be imparted by surface treatment such as corona discharge treatment described in JP-A No. 2001-350018.

(Configuration of polarizing plate)
First, a protective film and a polarizer constituting the polarizing plate of the present invention will be described.
The polarizing plate of the present invention is a polarizing plate in which a protective film is bonded to both sides of a polarizer, and at least one of the protective films is preferably the stretched optical resin film of the present invention.
Moreover, you may have an adhesive layer, a separate film, and a protective film as a component other than a polarizer and a protective film. Furthermore, it is preferable to provide a hard coat layer, an antiglare layer, an antireflection layer, and the like on the surface of the protective film. These layers will be described later.

(1) Protective film The polarizing plate of the present invention has two protective films, one on each side of the polarizer, and at least one is the stretched optical resin film of the present invention. Moreover, it is preferable that at least one of the two protective films has a function as a retardation film. When using the polarizing plate of this invention for a liquid crystal display device, it is preferable that at least one of the two polarizing plates arrange | positioned at the both sides of a liquid crystal cell is a polarizing plate of this invention.
The protective film used in the present invention is preferably a polymer film produced from norbornene resin, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, polyarylate, polysulfone, cellulose acylate, etc., and is a cellulose acylate film. Most preferred.

(2) Polarizer The polarizer of the present invention is preferably composed of polyvinyl alcohol (PVA) and a dichroic molecule. However, as described in JP-A-11-248937, PVA or polyvinyl chloride is used. A polyvinylene polarizer in which a polyene structure is generated by dehydration and dechlorination and oriented is also usable.

PVA is a polymer material obtained by saponifying polyvinyl acetate, but may contain components copolymerizable with vinyl acetate such as unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, and vinyl ethers. . In addition, modified PVA containing an acetoacetyl group, a sulfonic acid group, a carboxyl group, an oxyalkylene group, or the like can also be used.
The saponification degree of PVA is not particularly limited, but is preferably 80 to 100 mol%, particularly preferably 90 to 100 mol% from the viewpoint of solubility and the like. The degree of polymerization of PVA is not particularly limited, but is preferably 1000 to 10,000, and particularly preferably 1500 to 5000.
The syndiotacticity of PVA is preferably 55% or more for improving durability as described in Japanese Patent No. 2978219, but 45 to 52.5% described in Japanese Patent No. 3317494 is also preferably used. it can.

After PVA is formed into a film, it is preferable to introduce a dichroic molecule to constitute a polarizer. As a method for producing a PVA film, a method of forming a film by casting a stock solution in which a PVA resin is dissolved in water or an organic solvent is generally preferably used. The concentration of the polyvinyl alcohol-based resin in the stock solution is usually 5 to 20% by mass, and a PVA film having a thickness of 10 to 200 μm can be produced by forming this stock solution by casting. The PVA film can be produced with reference to Japanese Patent No. 3342516, Japanese Patent Application Laid-Open No. 09-328593, Japanese Patent Application Laid-Open No. 2001-302817, and Japanese Patent Application Laid-Open No. 2002-144401.
The degree of crystallinity of the PVA film is not particularly limited. However, in order to reduce the average crystallinity (Xc) of 50 to 75% by mass described in Japanese Patent No. 3251073 and the in-plane hue variation, Japanese Patent Application Laid-Open No. 2002-2005 A PVA film having a crystallinity of 38% or less described in No. 236214 can be used.

The birefringence (Δn) of the PVA film is preferably small, and a PVA film having a birefringence of 1.0 × 10 ⁻³ or less described in Japanese Patent No. 3342516 can be preferably used. However, as described in JP-A-2002-228835, in order to obtain a high degree of polarization while avoiding cutting during stretching of the PVA film, the birefringence of the PVA film may be set to 0.02 or more and 0.01 or less. Alternatively, as described in JP-A-2002-060505, the value of (nx + ny) / 2-nz may be 0.0003 or more and 0.01 or less. The retardation (in-plane) of the PVA film is preferably from 0 nm to 100 nm, and more preferably from 0 nm to 50 nm. Moreover, 0 nm or more and 500 nm or less are preferable, and, as for Rth (film thickness direction) of a PVA film, 0 nm or more and 300 nm or less are more preferable.

In addition, the polarizing plate of the present invention includes a PVA film having a 1,2-glycol bond amount of 1.5 mol% or less described in Japanese Patent No. 3021494, 5 μm or more described in JP-A No. 2001-316492. PVA film having 500 or less optical foreign matter per 100 cm ² , PVA film having a hot water cutting temperature spot of 1.5 ° C. or less in the TD direction of the film described in JP-A-2002-030163, and glycerin PVA film formed from a solution in which 1 to 100 parts by weight of a trivalent to hexavalent polyhydric alcohol such as 1 to 100 parts by weight or a plasticizer described in JP-A-6-289225 is mixed is preferably used. Can be used.

  Although the film thickness before extending | stretching of a PVA film is not specifically limited, 1 micrometer-1 mm are preferable and 20-200 micrometers is especially preferable from a viewpoint of stability of film holding | maintenance and the uniformity of extending | stretching. As described in JP-A-2002-236212, a thin PVA film in which the stress generated when stretching 4 to 6 times in water is 10 N or less may be used.

Dichroic molecule I ₃ ^- or I ₅ ^- can be preferably used an iodine ion or a dichroic dye higher such. In the present invention, higher-order iodine ions are particularly preferably used. Higher-order iodine ions can be found in “Applications of Polarizing Plates” by Ryo Nagata, CMC Publishing and Industrial Materials, Vol. 28, No. 7, p. 39-p. As described in 45, PVA can be produced by immersing PVA in a solution obtained by dissolving iodine in an aqueous potassium iodide solution and / or an aqueous boric acid solution and adsorbing and orienting the PVA.

  When a dichroic dye is used as the dichroic molecule, an azo dye is preferable, and a bisazo dye and a trisazo dye are particularly preferable. The dichroic dye is preferably a water-soluble dye. For this reason, a hydrophilic substituent such as a sulfonic acid group, an amino group or a hydroxyl group is introduced into the dichroic molecule, so that a free acid, an alkali metal salt, an ammonium salt or an amine is introduced. It is preferably used as a salt.

  Specific examples of such dichroic dyes include C.I. I. Direct Red 37, Congo Red (C.I. Direct Red 28), C.I. I. Direct Violet 12, C.I. I. Direct Blue 90, C.I. I. Direct Blue 22, C.I. I. Direct Blue 1, C.I. I. Direct Blue 151, C.I. I. Benzidines such as Direct Green 1, C.I. I. Direct Yellow 44, C.I. I. Direct Red 23, C.I. I. Diphenylurea such as Direct Red 79, C.I. I. Stilbene series such as Direct Yellow 12, C.I. I. Dinaphthylamine type such as Direct Red 31, C.I. I. Direct Red 81, C.I. I. Direct Violet 9, C.I. I. Mention may be made of J acid systems such as Direct Blue 78.

  In addition, C.I. I. Direct Yellow 8, C.I. I. Direct Yellow 28, C.I. I. Direct Yellow 86, C.I. I. Direct Yellow 87, C.I. I. Direct Yellow 142, C.I. I. Direct Orange 26, C.I. I. Direct Orange 39, C.I. I. Direct Orange 72, C.I. I. Direct Orange 106, C.I. I. Direct Orange 107, C.I. I. Direct Red 2, C.I. I. Direct Red 39, C.I. I. Direct Red 83, C.I. I. Direct Red 89, C.I. I. Direct Red 240, C.I. I. Direct Red 242, C.I. I. Direct Red 247, C.I. I. Direct Violet 48, C.I. I. Direct Violet 51, C.I. I. Direct Violet 98, C.I. I. Direct Blue 15, C.I. I. Direct Blue 67, C.I. I. Direct Blue 71, C.I. I. Direct Blue 98, C.I. I. Direct Blue 168, C.I. I. Direct Blue 202, C.I. I. Direct Blue 236, C.I. I. Direct Blue 249, C.I. I. Direct Blue 270, C.I. I. Direct Green 59, C.I. I. Direct Green 85, C.I. I. Direct Brown 44, C.I. I. Direct Brown 106, C.I. I. Direct Brown 195, C.I. I. Direct Brown 210, C.I. I. Direct Brown 223, C.I. I. Direct Brown 224, C.I. I. Direct Black 1, C.I. I. Direct Black 17, C.I. I. Direct Black 19, C.I. I. Direct Black 54 and the like are further disclosed in JP-A-62-70802, JP-A-1-161202, JP-A-1-172906, JP-A-1-172907, JP-A-1-183602, JP-A-1-248105, The dichroic dyes described in JP-A-1-265205 and JP-A-7-261024 can also be preferably used. In order to produce dichroic molecules having various hues, two or more of these dichroic dyes may be blended. When a dichroic dye is used, the adsorption thickness may be 4 μm or more as described in JP-A No. 2002-082222.

If the content of the dichroic molecule in the film is too small, the degree of polarization is low, and if it is too large, the single-plate transmittance is lowered. Therefore, the polyvinyl alcohol polymer constituting the film matrix is usually used. On the other hand, it is adjusted to a range of 0.01% by mass to 5% by mass.
A preferable film thickness of the polarizer is preferably 5 μm to 40 μm, and more preferably 10 μm to 30 μm. The ratio between the thickness of the polarizer and the thickness of the protective film described later is 0.01 ≦ A (polarizer film thickness) / B (protective film thickness) ≦ 0.16 described in JP-A No. 2002-174727. A range is also preferable.
The crossing angle between the slow axis of the protective film and the absorption axis of the polarizer may be any value, but is preferably parallel or an azimuth angle of 45 ± 20 °.

(Polarizing plate manufacturing process)
Next, the manufacturing process of the polarizing plate of this invention is demonstrated.
The production process of the polarizing plate in the present invention is preferably composed of a swelling process, a dyeing process, a hardening process, a stretching process, a drying process, a protective film bonding process, and a post-bonding drying process. The order of the dyeing step, the hardening step, and the stretching step may be arbitrarily changed, or several steps may be combined and performed simultaneously. Moreover, as described in Japanese Patent No. 3331615, washing with water after the hardening step can be preferably performed.

  In the present invention, it is particularly preferable to sequentially perform the swelling process, the dyeing process, the hardening process, the stretching process, the drying process, the protective film bonding process, and the drying process after bonding in the order described. An on-line surface inspection step may be provided during or after the above-described steps.

The swelling step is preferably performed only with water, but as described in JP-A-10-153709, in order to stabilize the optical performance and avoid wrinkling of the polarizing plate substrate in the production line, The degree of swelling of the polarizing plate substrate can also be managed by swelling the polarizing plate substrate with an aqueous boric acid solution.
Moreover, although the temperature and time of a swelling process can be defined arbitrarily, 10 to 60 degreeC and 5 to 2000 second are preferable.
For the dyeing step, the method described in JP-A No. 2002-86554 can be used. Further, as a dyeing method, not only immersion but any means such as application or spraying of iodine or a dye solution can be used. Further, as described in JP-A-2002-290025, iodine concentration, dye bath temperature, stretch ratio in the bath, and a method of dyeing while stirring the bath liquid in the bath may be used.

When higher-order iodine ions are used as the dichroic molecule, in order to obtain a high-contrast polarizing plate, it is preferable to use a solution obtained by dissolving iodine in an aqueous potassium iodide solution in the dyeing step. In this case, iodine in the iodine-potassium iodide aqueous solution is preferably 0.05 to 20 g / l, potassium iodide is 3 to 200 g / l, and the mass ratio of iodine and potassium iodide is preferably 1 to 2000. The dyeing time is preferably 10 to 1200 seconds, and the liquid temperature is preferably 10 to 60 ° C. More preferably, iodine is 0.5 to 2 g / l, potassium iodide is 30 to 120 g / l, the mass ratio of iodine and potassium iodide is 30 to 120, dyeing time is 30 to 600 seconds, and liquid temperature is 20-50 degreeC is good.
Further, as described in Japanese Patent No. 3145747, boron compounds such as boric acid and borax may be added to the dyeing solution.

  In the hardening step, it is preferable to immerse in the crosslinking agent solution or apply the solution to contain the crosslinking agent. Further, as described in JP-A-11-52130, the hardening process can be performed in several steps.

  As the cross-linking agent, those described in US Reissue Patent No. 232897 can be used, and as described in Japanese Patent No. 3357109, a polyhydric aldehyde may be used as a cross-linking agent in order to improve dimensional stability. However, boric acids are most preferably used. When boric acid is used as a crosslinking agent used in the hardening step, metal ions may be added to the boric acid-potassium iodide aqueous solution. Zinc chloride is preferred as the metal ion, but as described in JP 2000-35512 A, zinc halides such as zinc iodide, zinc sulfates, zinc acetates and the like are used instead of zinc chloride. You can also.

  In the present invention, it is preferable to prepare a boric acid-potassium iodide aqueous solution to which zinc chloride has been added, and perform dura- tion by immersing the PVA film. Boric acid is preferably 1 to 100 g / l, potassium iodide is 1 to 120 g / l, zinc chloride is preferably 0.01 to 10 g / l, hardening time is preferably 10 to 1200 seconds, and liquid temperature is preferably 10 to 60 ° C. . More preferably, boric acid is 10 to 80 g / l, potassium iodide is 5 to 100 g / l, zinc chloride is 0.02 to 8 g / l, hardening time is 30 to 600 seconds, and liquid temperature is 20 to 50 ° C is preferable.

  For the stretching step, a longitudinal uniaxial stretching method as described in US Pat. No. 2,454,515 or a tenter method as described in JP-A-2002-86554 can be preferably used. A preferable draw ratio is 2 times or more and 12 times or less, and more preferably 3 times or more and 10 times or less. Moreover, the relationship between the draw ratio, the thickness of the original fabric and the thickness of the polarizer is described in JP-A No. 2002-040256 (polarizer film thickness / raw film thickness after bonding of the protective film) × (total draw ratio) > 0.17 or the relationship between the width of the polarizer when leaving the final bath and the width of the polarizer when bonding the protective film is 0.80 ≦ (protective film pasting) described in JP-A-2002-040247 It is also preferable to satisfy the following condition: polarizer width at the time / width of the polarizer when leaving the final bath) ≦ 0.95.

  As the drying step, a method known in JP-A-2002-86554 can be used, but a preferable temperature range is 30 ° C. to 100 ° C., and a preferable drying time is 30 seconds to 60 minutes. Further, as described in Japanese Patent No. 3148513, heat treatment is performed so that the fading temperature in water is 50 ° C. or higher, or as described in Japanese Patent Laid-Open Nos. 07-325215 and 07-325218. Aging in a temperature and humidity controlled atmosphere can also be preferably performed.

  A protective film bonding process is a process of bonding the both surfaces of the above-mentioned polarizer which went out of the drying process with two protective films. A method of bonding with a pair of rolls is preferably used so that the adhesive liquid is supplied immediately before bonding and the polarizer and the protective film are overlapped. Further, as described in JP-A-2001-296426 and JP-A-2002-86554, the moisture content of the polarizer at the time of bonding is controlled in order to suppress the groove-like unevenness of the record due to the stretching of the polarizer. Is preferably adjusted. In the present invention, a moisture content of 0.1% to 30% is preferably used.

  The adhesive between the polarizer and the protective film is not particularly limited, and examples thereof include PVA resin (including modified PVA such as acetoacetyl group, sulfonic acid group, carboxyl group, oxyalkylene group) and boron compound aqueous solution. PVA resin is preferable. The thickness of the adhesive layer is preferably 0.01 to 5 μm, and particularly preferably 0.05 to 3 μm after drying.

Moreover, in order to improve the adhesive force of a polarizer and a protective film, it is preferable to perform adhesion after surface-treating the protective film to make it hydrophilic. The surface treatment method is not particularly limited, and a known method such as a saponification method using an alkaline solution or a corona treatment method can be used. Further, an easy-adhesion layer such as a gelatin undercoat layer may be provided after the surface treatment. As described in JP-A-2002-267839, the contact angle of the protective film surface with water is preferably 50 ° or less.
The drying conditions after bonding are in accordance with the method described in JP-A No. 2002-86554, but the preferred temperature range is 30 ° C. to 100 ° C., and the preferred drying time is 30 seconds to 60 minutes. It is also preferable to perform aging in an atmosphere with temperature and humidity control as described in JP-A-07-325220.

The element content in the polarizer is as follows: iodine 0.1-3.0 g / m ² , boron 0.1-5.0 g / m ² , potassium 0.1-2.00 g / m ² , zinc 0-2. It is preferably 00 g / m ² . Further, the potassium content may be 0.2% by mass or less as described in JP-A No. 2001-166143, and the zinc content in the polarizer is described in JP-A No. 2000-035512. It is good also as 0.04 mass%-0.5 mass%.

  As described in Japanese Patent No. 3323255, in order to increase the dimensional stability of the polarizing plate, an organic titanium compound and / or an organic zirconium compound is added and used in any of the dyeing process, stretching process and hardening process And at least 1 type of compound chosen from the organic titanium compound and the organic zirconium compound can also be contained. A dichroic dye may be added to adjust the hue of the polarizing plate.

(Characteristics of polarizing plate)
(1) Transmittance and degree of polarization The preferred single plate transmittance of the polarizing plate of the present invention is 42.5% or more and 49.5% or less, more preferably 42.8% or more and 49.0% or less. A preferable range of the degree of polarization defined by Formula 4 is 99.900% or more and 99.999% or less, and more preferably 99.940% or more and 99.995% or less. A preferable range of the parallel transmittance is 36% or more and 42% or less, and a preferable range of the orthogonal transmittance is 0.001% or more and 0.05% or less. A preferable range of the dichroic ratio defined by Formula 5 is 48 or more and 1215 or less, and more preferably 53 or more and 525 or less.
The above-described transmittance is defined based on JISZ8701.

  Here, K, S (λ), y (λ), and τ (λ) are as follows.

S (λ): spectral distribution of standard light used for color display y (λ): color matching function in XYZ system τ (λ): spectral transmittance

  The degree of polarization is defined by Equation 4 below.

The dichroic ratio is defined by the following formula 5.

The iodine concentration and the single plate transmittance may be within the ranges described in JP-A No. 2002-258051.
The parallel transmittance may be small in wavelength dependency as described in Japanese Patent Application Laid-Open Nos. 2001-083328 and 2002-022950. The optical characteristics when the polarizing plates are arranged in crossed Nicols may be in the range described in Japanese Patent Laid-Open No. 2001-091136, and the relationship between parallel transmittance and orthogonal transmittance is disclosed in Japanese Patent Laid-Open No. 2002-174728. It may be within the range described.

  As described in Japanese Patent Application Laid-Open No. 2002-221618, the standard deviation of the parallel transmittance every 10 nm when the light wavelength is between 420 and 700 nm is 3 or less, and the light wavelength is between 420 and 700 nm. The minimum value of (parallel transmittance / orthogonal transmittance) every 10 nm may be 300 or more.

  The parallel transmittance and the orthogonal transmittance at a wavelength of 440 nm of the polarizing plate, the parallel transmittance, the parallel transmittance and the orthogonal transmittance at a wavelength of 550 nm, and the parallel transmittance and the orthogonal transmittance at a wavelength of 610 nm are disclosed in JP-A No. 2002-258042 and JP-A No. The range described in 2002-258043 can also be preferably performed.

(2) Hue The hue of the polarizing plate of the present invention is preferably evaluated using the lightness index L ^* and the chromaticness index a ^* and b ^* in the L ^* a ^* b ^* color system recommended as the CIE uniform perceptual space. Is done.
L ^* , a ^* , and b ^* are defined by Equation 6 using X, Y, and Z described above.

Here, X ₀ , Y ₀ , and Z ₀ represent tristimulus values of the illumination light source. In the case of standard light C, X ₀ = 98.072, Y ₀ = 100, Z ₀ = 118.225, and standard light D _In the case of ₆₅ , X ₀ = 95.045, Y ₀ = 100, Z ₀ = 108.892.

The preferable range of a ^* for a single polarizing plate is −2.5 or more and 0.2 or less, and more preferably −2.0 or more and 0 or less. A preferable range of b ^* of the single polarizing plate is 1.5 or more and 5 or less, and more preferably 2 or more and 4.5 or less. The preferable range of a ^* of the parallel transmitted light of the two polarizing plates is −4.0 to 0, and more preferably −3.5 to −0.5. The preferred range of b ^* of the parallel transmitted light of the two polarizing plates is 2.0 or more and 8 or less, more preferably 2.5 or more and 7 or less. The preferable range of a ^* of the orthogonally transmitted light of the two polarizing plates is −0.5 or more and 1.0 or less, and more preferably 0 or more and 2 or less. The preferable range of b ^* of the orthogonally transmitted light of the two polarizing plates is −2.0 or more and 2 or less, and more preferably −1.5 or more and 0.5 or less.

The hue may be evaluated by the chromaticity coordinates (x, y) calculated from the aforementioned X, Y, and Z. For example, the chromaticity (x _p , y _p ) of the parallel transmitted light of the two polarizing plates. And the chromaticity (x _c , y _c ) of the orthogonal transmitted light are within the ranges described in JP-A-2002-214436, JP-A-2001-166136, and JP-A-2002-169024, or the relationship between the hue and the absorbance. It can also be preferably performed within the range described in JP-A-2001-311827.

(3) Viewing angle characteristics When a polarizing plate is arranged in crossed Nicol and light with a wavelength of 550 nm is incident, when vertical light is incident, from a azimuth of 45 degrees with respect to the polarization axis, 40 degrees with respect to the normal line It is also preferable that the transmittance ratio and the xy chromaticity difference when the light is incident at an angle of within the range described in Japanese Patent Application Laid-Open Nos. 2001-166135 and 2001-166137. Further, as described in JP-A-10-068817, the light transmittance (T ₀ ) in the vertical direction of the polarizing plate laminate having the crossed Nicols arrangement and the light transmission in the direction inclined by 60 ° from the normal line of the laminate. The ratio (T ₆₀ / T ₀ ) to the rate (T ₆₀ ) is 10000 or less, or as described in JP-A No. 2002-139625, the polarizing plate is at an arbitrary angle from the normal to an elevation angle of 80 degrees. When natural light is incident, the transmittance difference of transmitted light within a wavelength range of 20 nm within the wavelength range of 520 to 640 nm of the transmission spectrum is set to 6% or less, or a film described in JP-A-08-248201 It is also preferable that the brightness difference of the transmitted light at an arbitrary place 1 cm above is within 30%.

(4) Durability (4-1) Wet heat durability As described in JP-A-2001-116922, light transmittance and polarization degree before and after standing in an atmosphere of 60 ° C. and 90% RH for 500 hours. It is preferable that the change rate of is 3% or less based on the absolute value. In particular, the change rate of the light transmittance is 2% or less, and the change rate of the polarization degree is preferably 1.0% or less, more preferably 0.1% or less based on the absolute value. Further, as described in JP-A-07-0777608, it is also preferred that the degree of polarization after standing at 80 ° C. and 90% RH for 500 hours is 95% or more and the single transmittance is 38% or more.

(4-2) Dry durability It is preferable that the light transmittance and the rate of change of the degree of polarization before and after standing in a dry atmosphere at 80 ° C. for 500 hours are also 3% or less based on absolute values. In particular, the change rate of the light transmittance is preferably 2% or less, and the change rate of the polarization degree is preferably 1.0% or less, more preferably 0.1% or less based on the absolute value.

(4-3) Other durability Further, as described in JP-A-06-167611, the shrinkage after standing at 80 ° C. for 2 hours is 0.5% or less, or the both sides of the glass plate are crossed. The x and y values after leaving the Nicol-arranged polarizing plate laminate in an atmosphere of 69 ° C. for 750 hours are within the ranges described in JP-A-10-068818, or an atmosphere of 80 ° C. and 90% RH. the change in spectral intensity ratio of the 105 cm ^-1 and 157cm ^-1 after 200 hours standing processing by Raman spectroscopy at medium, it is also preferable to fall within the range as described in JP-a-08-094834 and JP-a-09-197127 It can be carried out.

(5) Orientation degree The higher the degree of orientation of PVA, the better the polarization performance, but the range of 0.2 to 1.0 is preferable as the order parameter value calculated by means such as polarization Raman scattering or polarization FT-IR. It is. Further, as described in JP-A-59-133509, the difference between the orientation coefficient of the polymer segment in the entire amorphous region of the polarizer and the orientation coefficient of the occupied molecule (0.75 or more) is at least 0. 15, the orientation coefficient of the amorphous region of the polarizer is 0.65 to 0.85 as described in JP-A No. 04-204907, and the higher order iodine ions of I ₃ ⁻ and I ₅ ⁻ It is also preferable to set the degree of orientation to 0.8 to 1.0 as an order parameter value.

(6) Other properties As described in JP-A-2002-006133, the contraction force in the absorption axis direction per unit width when heated at 80 ° C. for 30 minutes is 4.0 N / cm or less, As described in 2002-236213, when the polarizing plate was placed under heating conditions of 70 ° C. for 120 hours, both the dimensional change rate in the absorption axis direction and the dimensional change rate in the polarization axis direction of the polarizing plate were It is also preferable to make it within ± 0.6%, or to set the moisture content of the polarizing plate to 3% by mass or less as described in JP-A-2002-090546. Further, as described in JP-A No. 2000-249832, the surface roughness in the direction perpendicular to the stretching axis is set to 0.04 μm or less based on the center line average roughness, or described in JP-A No. 10-268294. The refractive index n ₀ in the transmission axis direction is preferably made larger than 1.6, or the relationship between the thickness of the polarizing plate and the thickness of the protective film is preferably within the range described in JP-A-10-111411. be able to.

(Functionalization of polarizing plate)
The polarizing plate of the present invention includes an LCD viewing angle widening film, a retardation film such as a λ / 4 plate for application to a reflective LCD, an antireflection film for improving display visibility, a brightness enhancement film, It is preferably used as a functionalized polarizing plate combined with an optical film having functional layers such as a coat layer, a forward scattering layer, and an antiglare (antiglare) layer.
One embodiment of the configuration in which the polarizing plate of the present invention and the above-described functional optical film are combined is shown in FIG. The functional optical film 3 may be bonded to the polarizer 2 through an adhesive layer as a protective film on one side of the polarizing plate 5 (FIG. 1A), and the protective films 1a and 1b are attached to both surfaces of the polarizer 2. The functional optical film 3 may be bonded to the provided polarizing plate 5 through the adhesive layer 4 (FIG. 1B). In the former case, an arbitrary transparent protective film may be used for the other protective film 1. Moreover, in the polarizing plate of this invention, it is also preferable to stick an optical functional layer to a protective film through an adhesion layer, and to set it as the structure of FIG. It is also preferable that the peel strength between the layers such as the functional layer and the protective film is 4.0 N / 25 mm or more described in JP-A No. 2002-311238. The functional optical film is preferably disposed on the liquid crystal module side according to the intended function, or on the side opposite to the liquid crystal module, that is, on the display side or the backlight side.

The functional optical film used in combination with the polarizing plate of the present invention will be described below.
(1) Viewing Angle Enlargement Film The polarizing plate of the present invention includes TN (Twisted Nematic), IPS (In-Plane Switching), OCB (Optically Compensatory).
Bend), VA (Vertically Aligned), and ECB (Electrically Controlled Birefringence) can be used in combination with a viewing angle widening film proposed for display modes.

As a viewing angle widening film for TN mode, Journal of the Japan Printing Society Vol. 36 No. 3 (1999) p. 40-44, monthly display August issue (2002) p. No. 20-24, JP-A-4-229828, JP-A-6-75115, JP-A-6-214116, JP-A-8-50206, etc. are preferably used in combination with WV film (manufactured by Fuji Photo Film Co., Ltd.). The
A preferred configuration of the viewing angle widening film for the TN mode has an alignment layer and an optically anisotropic layer in this order on the transparent polymer film. Although a viewing angle expansion film may be used by being bonded to a polarizing plate via an adhesive, SID'00 Dig. , P. As described in 551 (2000), it is particularly preferable from the viewpoint of thinning that one of the protective films of the polarizer is also used.

  The alignment layer can be provided by means such as a rubbing treatment of an organic compound (preferably a polymer), oblique deposition of an inorganic compound, or formation of a layer having a microgroup. Furthermore, an alignment layer in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known. The rubbing treatment is preferably performed by rubbing the surface of the polymer layer several times in a certain direction with paper or cloth. It is preferable that the absorption axis direction and the rubbing direction of the polarizer are substantially parallel. As the polymer used for the alignment layer, polyimide, polyvinyl alcohol, a polymer having a polymerizable group described in JP-A-9-152509, and the like can be preferably used. The thickness of the alignment layer is preferably 0.01 to 5 μm, and more preferably 0.05 to 2 μm.

  The optically anisotropic layer preferably contains a liquid crystalline compound. The liquid crystal compound used in the present invention particularly preferably has a discotic compound (discotic liquid crystal). The discotic liquid crystal molecule has a disk-like core portion like a triphenylene derivative represented by the following chemical formula, and has a structure in which side chains extend radially therefrom. In order to impart stability over time, it is also preferable to further introduce a group that reacts with heat, light or the like. Preferred examples of the discotic liquid crystal are described in JP-A-8-50206.

  The discotic liquid crystal molecules are aligned almost parallel to the film plane with a pretilt angle in the rubbing direction in the vicinity of the alignment layer, and the discotic liquid crystal molecules are oriented so that they are perpendicular to the plane on the opposite air side. doing. The discotic liquid crystal layer as a whole has a hybrid alignment, and this layer structure can realize a wide viewing angle of a TN mode TFT-LCD.

  The optically anisotropic layer is generally a discotic compound and another compound (for example, a polymerizable monomer, a photopolymerization initiator) dissolved in a solvent, coated on the alignment layer, dried, and then discotic nematic. After heating to the phase formation temperature, it is obtained by polymerization by irradiation with UV light or the like and further cooling. The discotic nematic liquid crystal phase-solid phase transition temperature of the discotic liquid crystalline compound used in the present invention is preferably 70 to 300 ° C, particularly preferably 70 to 170 ° C.

In addition to the discotic compound added to the optically anisotropic layer, the compound has compatibility with the discotic compound and can give a preferable change in tilt angle to the liquid crystalline discotic compound or inhibit the alignment. Any compound can be used as long as it is not. Among these, additives for controlling the orientation on the air interface side such as polymerizable monomers (eg, compounds having vinyl group, vinyloxy group, acryloyl group and methacryloyl group), fluorine-containing triazine compounds, cellulose acetate, cellulose acetate Mention may be made of polymers such as pionate, hydroxypropylcellulose and cellulose acetate butyrate. These compounds are generally used in an amount of 0.1 to 50% by mass, preferably 0.1 to 30% by mass, based on the discotic compound.
The thickness of the optically anisotropic layer is preferably 0.1 to 10 μm, and more preferably 0.5 to 5 μm.

  A preferred embodiment of the viewing angle widening film is composed of a cellulose acylate film as a transparent substrate film, an alignment layer provided thereon, and an optically anisotropic layer comprising a discotic liquid crystal formed on the alignment layer And the optically anisotropic layer is crosslinked by UV light irradiation.

  In addition to the above, when the viewing angle widening film and the polarizing plate of the present invention are combined, for example, as described in JP-A-07-198942, a compound having an optical axis in a direction intersecting the plate surface is used. It is also preferable to laminate with a phase difference plate exhibiting anisotropy in refraction or to make the dimensional change rate of the protective film and the optically anisotropic layer substantially the same as described in JP-A No. 2002-258052. It can be carried out. Further, as described in JP-A-12-258632, the moisture content of the polarizing plate bonded to the viewing angle widening film is set to 2.4% or less, or as described in JP-A-2002-267839. Further, the contact angle with water on the surface of the viewing angle widening film can be preferably set to 70 ° or less.

  The viewing angle widening film for an IPS mode liquid crystal cell is used for optical compensation of liquid crystal molecules aligned in parallel to the substrate surface and for improving the viewing angle characteristics of the orthogonal transmittance of the polarizing plate during black display without an electric field. In the IPS mode, black is displayed when no electric field is applied, and the transmission axes of the pair of upper and lower polarizing plates are orthogonal. However, when observed from an oblique direction, the crossing angle of the transmission axes is not 90 °, and leakage light is generated, resulting in a decrease in contrast. When the polarizing plate of the present invention is used in an IPS mode liquid crystal cell, the in-plane retardation as described in JP-A-10-54982 is close to 0 and the thickness direction is reduced in order to reduce leakage light. It is preferably used in combination with a viewing angle widening film having a phase difference.

  The OCB mode viewing angle widening film for liquid crystal cells is intended to improve the viewing angle characteristics of black display by optically compensating the liquid crystal layer that is vertically aligned at the center of the liquid crystal layer by applying an electric field and tilted near the substrate interface. used. When the polarizing plate of the present invention is used in an OCB mode liquid crystal cell, it is preferably used in combination with a viewing angle widening film in which a discotic liquid crystalline compound as described in US Pat. No. 5,805,253 is hybrid-aligned.

The viewing angle widening film for liquid crystal cells in the VA mode improves the viewing angle characteristics of black display in a state where liquid crystal molecules are vertically aligned with respect to the substrate surface in the absence of an electric field. As such a viewing angle widening film, a film having an in-plane retardation close to 0 and having a retardation in the thickness direction as described in Japanese Patent No. 2866372, and a discotic compound are used. Films arranged in parallel to the substrate, stretched films with the same in-plane retardation value laminated so that the slow axes are orthogonal, and liquid crystals to prevent the deterioration of orthogonal transmittance in the oblique direction of the polarizing plate It is preferably used in combination with a laminate of films made of rod-like compounds such as molecules.
Moreover, what gave phase difference by extending | stretching norbornene-type resin film and polycarbonate resin can also be used preferably as a viewing angle expansion film or its part.

(2) Retardation film The polarizing plate of the present invention preferably has a retardation layer. The retardation layer in the present invention is preferably a λ / 4 plate, and can be used as a circularly polarizing plate by laminating the polarizing plate of the present invention and the λ / 4 plate. The circularly polarizing plate has a function of converting incident light into circularly polarized light, and is preferably used for a reflective liquid crystal display device, a transflective liquid crystal display device such as an ECB mode, or an organic EL element.

  The λ / 4 plate used in the present invention is a retardation film having a retardation (Re) of approximately ¼ of the wavelength in the visible light wavelength range in order to obtain almost perfect circularly polarized light in the visible light wavelength range. It is preferable that “Retardation of approximately ¼ in the wavelength range of visible light” means that the longer the wavelength is from 400 to 700 nm, the larger the retardation, and the retardation value (Re450) measured at a wavelength of 450 nm is 80 to 125 nm. And the range which satisfies the relationship whose retardation value (Re590) measured by wavelength 590nm is 120-160 nm is shown. It is more preferable that Re590-Re450 ≧ 5 nm, and it is particularly preferable that Re590-Re450 ≧ 10 nm.

  The λ / 4 plate used in the present invention is not particularly limited as long as the above conditions are satisfied, but for example, described in JP-A-5-27118, JP-A-10-68816, and JP-A-10-90521. A λ / 4 plate obtained by laminating a plurality of polymer films, a λ / 4 plate obtained by stretching a single polymer film described in WO00 / 65384, WO00 / 26705, JP 2000-284126 A, A known λ / 4 plate such as a λ / 4 plate in which at least one optically anisotropic layer is provided on a polymer film described in JP-A-2002-31717 can be used. Moreover, the direction of the slow axis of the polymer film and the orientation direction of the optically anisotropic layer can be arranged in any direction according to the liquid crystal cell.

  In the circularly polarizing plate, the slow axis of the λ / 4 plate and the transmission axis of the polarizer can intersect at an arbitrary angle, but preferably intersect within a range of 45 ° ± 20 °. However, the slow axis of the λ / 4 plate and the transmission axis of the polarizer may intersect within a range other than the above.

  When the λ / 4 plate is formed by laminating the λ / 4 plate and the λ / 2 plate, as described in Japanese Patent No. 3236304 and Japanese Patent Laid-Open No. 10-68816, the λ / 4 plate and The λ / 2 plate is preferably bonded so that the angle formed between the slow axis in the plane of the λ / 2 plate and the transmission axis of the polarizing plate is substantially 75 ° and 15 °.

(Adhesive)
Next, the pressure-sensitive adhesive preferably used in the present invention will be described.
As the adhesive, an adhesive using a base polymer such as acrylic acid, methacrylic acid, butyl rubber, or silicone can be used. Although not particularly limited, (meth) acrylate base polymers such as butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, A copolymer base polymer using two or more of these (meth) acrylic acid esters is preferably used. In the pressure-sensitive adhesive, a polar monomer is usually copolymerized in these base polymers. Examples of the polar monomer include (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, Examples thereof include monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group, and the like, such as glycidyl (meth) acrylate.

  The pressure-sensitive adhesive usually contains a crosslinking agent. Crosslinking agents include those that generate divalent or polyvalent metal ions and carboxylate metal salts, those that form amide bonds with polyamine compounds, those that form ester bonds with polyepoxy compounds and polyols, polyisocyanate compounds and amides. Examples of these compounds include one that forms a bond, and these compounds are used as a cross-linking agent in one or more kinds and mixed with a base polymer.

  As for the thickness of the adhesive layer of this invention, 2-50 micrometers is preferable. It is a normal form that a separate film is bonded to the surface of the pressure-sensitive adhesive layer opposite to the polarizing plate in order to protect the pressure-sensitive adhesive layer. As the separate film, a polyester film that has been subjected to a release treatment with a silicone resin or the like is used. This separate film is peeled and removed at the time of bonding with a liquid crystal cell or another optical functional film.

(Liquid crystal display device using polarizing plate)
Next, a liquid crystal display device in which the polarizing plate of the present invention is used will be described. In the liquid crystal display device of the present invention, two polarizing plates are arranged on both sides of the liquid crystal cell, and at least one of the polarizing plates is the polarizing plate of the present invention.

FIG. 2 is an example of a liquid crystal display device in which the polarizing plate of the present invention is used.
The liquid crystal display device shown in FIG. 2 of the present invention includes a liquid crystal cell (10-13), and an upper polarizing plate 6 and a lower polarizing plate 17 that are disposed with the liquid crystal cell (10-13) interposed therebetween. The polarizing plate is sandwiched between a polarizer and a pair of transparent protective films, but is shown as an integrated polarizing plate in FIG. The liquid crystal cell includes a liquid crystal layer formed of an upper electrode substrate 10 and a lower electrode substrate 13 and liquid crystal molecules 12 sandwiched therebetween. The liquid crystal cell is different in the alignment state of liquid crystal molecules that perform ON / OFF display. However, the polarizing plate of the present invention can be used in any display mode regardless of the transmissive and reflective types.
Among these display modes, the OCB mode or the VA mode is preferable.

  An alignment film (not shown) is formed on the surface of the electrode substrates 10 and 13 in contact with the liquid crystal molecules 12 (hereinafter sometimes referred to as “inner surface”), and is formed by a rubbing process or the like applied on the alignment film. The orientation of the liquid crystal molecules 12 in a state where no electric field is applied or a state where a low voltage is applied is controlled. Further, on the inner surfaces of the substrates 10 and 13, a transparent electrode (not shown) capable of applying an electric field to the liquid crystal layer made of the liquid crystal molecules 12 is formed.

The rubbing direction of the TN mode is applied in directions perpendicular to each other on the upper and lower substrates, and the magnitude of the tilt angle can be controlled by the strength and the number of rubbing times. The alignment film is formed by applying and baking a polyimide film. The magnitude of the twist angle (twist angle) of the liquid crystal layer is determined by the crossing angle of the upper and lower substrates in the rubbing direction and the chiral agent added to the liquid crystal material. Here, a chiral agent having a pitch of about 60 μm is added so that the twist angle becomes 90 °.
The twist angle is in the vicinity of 90 ° (85 to 95 °) in the case of a notebook computer, a personal computer monitor, and a liquid crystal display device for a television, and is 0 to 70 ° in the case of use as a reflective display device such as a mobile phone. Set. In the IPS mode and the ECB mode, the twist angle is 0 °. In the IPS mode, electrodes are disposed only on the lower substrate 8 and an electric field parallel to the substrate surface is applied. In the OCB mode, there is no twist angle and the tilt angle is increased, and in the VA mode, the liquid crystal molecules 12 are aligned perpendicular to the upper and lower substrates.

Here, the magnitude of the product Δnd of the thickness d of the liquid crystal layer and the refractive index anisotropy Δn changes the brightness during white display. Therefore, in order to obtain the maximum brightness, the range is set for each display mode.
The crossing angle between the absorption axis 7 of the upper polarizing plate 6 and the absorption axis 18 of the lower polarizing plate 17 is generally laminated substantially orthogonally to obtain a high contrast. The crossing angle between the absorption axis 7 of the upper polarizing plate 6 of the liquid crystal cell and the rubbing direction of the upper substrate 10 varies depending on the liquid crystal display mode, but is generally set to be parallel or vertical in the TN and IPS modes. In OCB and ECB modes, it is often set to 45 °. However, the optimum value differs in each display mode for adjusting the color tone and viewing angle of the display color, and the present invention is not limited to this range.

  The liquid crystal display device in which the polarizing plate of the present invention is used is not limited to the configuration of FIG. 2, and may include other members. For example, a color filter may be disposed between the liquid crystal cell and the polarizer. Moreover, the viewing angle widening film mentioned above can also be separately arranged between the liquid crystal cell and the polarizing plate. The polarizing plates 6 and 17 and the optically anisotropic layers (viewing angle widening films) 8 and 15 may be arranged in a laminated form bonded with an adhesive, and one of the liquid crystal cell side protective films is used for widening the viewing angle. It may be arranged as a so-called integrated elliptical polarizing plate.

  When the liquid crystal display device using the polarizing plate of the present invention is used as a transmission type, a backlight using a cold cathode or a hot cathode fluorescent tube, or a light emitting diode, a field emission element, or an electroluminescent element as a light source. Can be placed on the back. Further, the liquid crystal display device in which the polarizing plate of the present invention is used may be of a reflective type. In such a case, only one polarizing plate may be disposed on the observation side, and the back of the liquid crystal cell or under the liquid crystal cell. A reflective film is installed on the inner surface of the side substrate. Of course, a front light using the light source may be provided on the liquid crystal cell observation side. The liquid crystal display device of the present invention is preferably a VA mode liquid crystal display device using the polarizing plate of the present invention on the backlight side of the cell.

[Example 1]
<Preparation of Cellulose Acylate Film 1>
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acylate solution.

(Cellulose acylate solution A composition)
Cellulose acetate with a degree of acetyl substitution of 2.75 100.0 parts by weight Triphenyl phosphate (plasticizer) 9.0 parts by weight Ethylphthalyl ethyl glycolate (plasticizer) 3.5 parts by weight Polystyrene (negative intrinsic birefringence) Additive, Aldrich Mw. 800)
2.0 parts by mass Methylene chloride (first solvent) 403.0 parts by mass Methanol (second solvent) 60.2 parts by mass

(Preparation of matting agent solution)
The following composition was charged into a disperser and stirred to dissolve each component to prepare a matting agent solution.

(Matting agent solution composition)
Silica particles having an average particle diameter of 16 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd. 2.0 parts by mass Methylene chloride (first solvent) 72.4 parts by mass Methanol (second solvent) 10.8 parts by mass Cellulose acetate solution A 0 .3 parts by mass

(Preparation of cellulose acylate film 1)
98.7 parts by mass of the cellulose acetate solution A and 1.3 parts by mass of the matting agent solution were mixed after filtration, and the film was peeled off from the band with a residual solvent content of 35% cast using a band casting machine. The film was stretched transversely at a stretch ratio of 35% using a tenter under the conditions of 130 ° C., and held at 140 ° C. for 30 seconds with the stretched width. Thereafter, the clip was removed and dried at 140 ° C. for 40 minutes to produce a cellulose acylate film 1. The finished cellulose acylate film 1 had a residual solvent amount of 0.2% and a film thickness of 92 μm.

[Example 2]
<Preparation of Cellulose Acylate Film 2>
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acylate solution.

(Cellulose acylate solution B composition)
Cellulose acetate with an acetyl substitution degree of 2.75 100.0 parts by weight Triphenyl phosphate (plasticizer) 9.0 parts by weight Ethylphthalyl ethyl glycolate (plasticizer) 3.5 parts by weight Polystyrene (negative intrinsic birefringence) Additive, Aldrich Mw. 800)
1.0 part by mass Methylene chloride (first solvent) 403.0 parts by mass Methanol (second solvent) 60.2 parts by mass

(Preparation of cellulose acylate film 2)
98.7 parts by mass of the cellulose acetate solution A and 1.3 parts by mass of the matting agent solution were mixed after filtration, and the film was peeled off from the band with a residual solvent content of 35% cast using a band casting machine. The film was stretched transversely at a draw ratio of 18% using a tenter under the conditions of 130 ° C. and held at 140 ° C. for 30 seconds with the stretched width. Thereafter, the clip was removed and dried at 140 ° C. for 40 minutes to produce a cellulose acylate film 1. The finished cellulose acylate film 1 had a residual solvent amount of 0.3% and a film thickness of 94 μm.

[Example 3]
<Preparation of stretched cycloolefin polymer film 1>
(Synthesis of cycloolefin polymer 1)
In a reaction vessel purged with nitrogen, 8-methyl-8-carboxymethyltetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 225 parts of specific monomer b, 25 parts of bicyclo [2.2.1] hept-2-ene, 18 parts of 1-hexene as a molecular weight regulator, and toluene 750 as a solvent. The solution was heated to 60 ° C. Next, 0.62 parts of a toluene solution containing 1.5 mol / l of triethylaluminum as a polymerization catalyst and tungsten hexachloride modified with t-butanol and methanol (t-butanol: methanol: tungsten) were added to the solution in the reaction vessel. = 0.35 mol: 0.3 mol: 1 mol) containing 3.7 parts of a 0.05 mol / l toluene solution, and the system was opened by heating and stirring at 80 ° C. for 3 hours. A ring-opening copolymer solution was obtained by a ring copolymerization reaction.
The polymerization conversion rate in this polymerization reaction was 97%, and the intrinsic viscosity (η _inh ) in 30 ° C. chloroform of the ring-opening copolymer constituting the obtained ring-opening copolymer solution was measured. It was 65 dl / g.

The autoclave was charged with 4000 parts of the obtained ring-opening copolymer solution, and carbonylchlorohydridotris (triphenylphosphine) ruthenium: RuHCl (CO) [P (C ₆ H ₅ ) ₃ ] was added to the ring-opening copolymer solution. 0.48 parts of ₃ was added, and the hydrogenation reaction was performed by heating and stirring for 3 hours under the conditions of a hydrogen gas pressure of 100 kg / cm ² and a reaction temperature of 165 ° C.
After cooling the obtained reaction solution (hydrogenated polymer solution), the hydrogen gas was released. This reaction solution was poured into a large amount of methanol to separate and recover a coagulated product, which was dried to obtain a hydrogenated polymer (hereinafter also referred to as “cycloolefin polymer 1”).

About the obtained cycloolefin polymer 1, a hydrogenation rate is set to 400 MHz ¹ H-
It was 99.9% as measured by NMR spectrum.
Further, the proportion of the structural unit b derived from bicyclo [2.2.1] hept-2-ene in the cycloolefin polymer 1 is measured by measuring a 400 MHz ¹ H-NMR spectrum, and appears in the vicinity of about 3.7 ppm. -Methyl-8-carboxymethyltetracyclo [4.4.0.12,5.17,10] -3-the peak of absorption of the methyl proton of the methyl ester of the structural unit a derived from dodecene; It was 20.1% when calculated based on the absorption peak of the proton of the alicyclic structure of structural unit a and structural unit b appearing at 3 ppm. In addition, by gel permeation chromatography (GPC), a polystyrene-equivalent weight average molecular weight Mw of 10,000 or less, 10,000 to 30,000 or less, and 30,000 or more are collected. When the proportion of each structural unit b was confirmed by a 400 MHz ¹ H-NMR spectrum, the variation with respect to the value of 20.1%, which is the proportion of the entire cycloolefin polymer 1, was all within 15%.

(Preparation of cycloolefin polymer film 1)
Cycloolefin polymer 1 was dissolved in toluene to a concentration of 30%. The solution viscosity at room temperature of the obtained solution was 30,000 mPa · s.
To this solution, pentaerythrityltetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] as an antioxidant was added in an amount of 0.1 mass per 100 mass parts of the cycloolefin polymer. 1 part by weight of a styrene-maleic anhydride copolymer (manufactured by Sekisui Chemical Co., Ltd., trade name: Dilark D332) as a negative intrinsic birefringent additive with respect to 100 parts by weight of cycloolefin polymer 1 After filtering the resulting solution using a sintered metal fiber filter made by Nippon Pole with a pore size of 5 μm while controlling the flow rate of the solution so that the differential pressure is within 0.4 MPa, a clean room of class 1000 Using “INVEX Lab Coater” made by Inoue Metal Industry installed in the inside, it is made hydrophilic with an acrylic acid surface treatment agent (to make it easy to adhere) Treated, thickness was applied to 100μm PET film (Toray Industries Co., Ltd. "Lumirror U94").
Next, the obtained liquid layer was subjected to a primary drying treatment at 50 ° C., and further subjected to a secondary drying treatment at 90 ° C., and then peeled off from the PET film, whereby a resin film having a thickness of 99 μm (hereinafter referred to as “a”). , Also referred to as “cycloolefin polymer film 1”). The resulting cycloolefin polymer film 1 had a residual solvent amount of 0.5% by mass and a light transmittance of 93% or more.

  Further, the cycloolefin polymer film 1 was heated to 120 ° C. (Tg + 10 ° C.) in a tenter and stretched 1.05 times in the longitudinal direction in the film in-plane direction at a stretching rate of 300% / min, The film is stretched 1.5 times in the transverse direction, and then cooled while maintaining this state for 1 minute in an atmosphere of 90 ° C. (Tg−20 ° C.), further cooled at room temperature, and taken out from the tenter. A stretched cycloolefin polymer film 1 was obtained. The thickness was 87 μm.

[Comparative Example 1]
<Preparation of laminated retardation film>
(Oriented stretched polymer film B)
A polycarbonate film (trade name: Pure Ace WR (Teijin Co., Ltd.)) having a thickness of 80 μm, which is made of a copolymer containing monomer units that form polymers with different wavelength dispersion characteristics produced by casting and stretching. A polycarbonate film was used for the stretched polymer film B serving as a base.

<Preparation of liquid crystal layer coating solution>
As a coating liquid for forming a liquid crystal layer having forward wavelength dispersion, a liquid crystal material having a polymerizable acrylate group at both ends and having a spacer between the mesogen in the central portion and the acrylate, the following liquid crystal material (B ) Was used. In addition, Irgacure Irg184 (manufactured by Chiba Specialty Chemicals) was used as the photopolymerization initiator (B). Furthermore, the following chiral agent (B) having acrylate groups polymerizable at both ends was used as a chiral agent. In the chiral agent (B) of formula 4, X = 3.

(Preparation of liquid crystal layer coating solution)
The following composition was charged into a disperser and stirred to dissolve each component to prepare a liquid crystal layer coating solution.

(Liquid crystal layer coating solution composition)
Liquid crystal material (B) 75.0 parts by mass Photopolymerization initiator (B) 1.0 part by mass Toluene (solvent) 25.0 parts by mass Chiral agent (B) 10.0 parts by mass

(Chiral nematic (cholesteric) liquid crystal layer deposition)
The prepared coating solution was applied onto the stretched polymer film B using a spin coating method.

  Subsequently, the film coated with the polymerizable liquid crystal coating solution was heated on a hot plate at 100 ° C. for 5 minutes to remove the residual solvent, and a twist-aligned liquid crystal structure was developed.

Subsequently, the applied liquid crystal layer was irradiated with ultraviolet rays (20 mJ / cm ² , wavelength 365 nm) to obtain a laminated film structure of a chiral nematic (cholesteric) liquid crystal layer having a thickness of 4.0 μm. The spiral pitch of the liquid crystal layer was 180 nm, and the reflection wavelength was 280 nm. This laminated retardation film was designated as a laminated retardation film 1.

<Measurement of retardation>
In-plane retardation Re (0) was measured using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments). Retardation Re (40) and Re (-40) were measured with the in-plane slow axis as the tilt axis at 40 ° and -40 °. Using the film thickness and the refractive index nx in the slow axis direction as parameters, the refractive index ny and the thickness direction in the fast axis direction are fitted to these measured values Re (0), Re (40), and Re (−40). The refractive index nz was determined by calculation to determine the Rth retardation value. The measurement wavelengths were 480 nm, 546 nm, and 628 nm.

  Table 1 shows the measurement results of film properties.

  From the results shown in Table 1, the stretched optical resin film of the present invention was able to make Re in the forward dispersion and Rth in the reverse dispersion by a simple manufacturing method without a coating process, as compared with the laminated retardation film of the comparative example.

[Example 4]
(Saponification treatment)
The cellulose acetate film 1 was immersed in a 1.5 N aqueous sodium hydroxide solution at 55 ° C. for 2 minutes. It wash | cleaned in the room temperature water-washing tub, and neutralized using 0.1 N sulfuric acid at 30 degreeC. Again, it was washed in a water bath at room temperature and further dried with hot air at 100 ° C. In this way, the surface of the cellulose acetate film was saponified.

(Preparation of polarizing plate)
A polarizing film was prepared by adsorbing iodine to a stretched polyvinyl alcohol film.
Next, the transparent support side of the produced cellulose acetate film was attached to one side of the polarizing film using a polyvinyl alcohol-based adhesive. The slow axis of the transparent support and the transmission axis of the polarizing film were arranged in parallel.
A commercially available cellulose triacetate film (Fujitac TD80UF, manufactured by Fuji Photo Film Co., Ltd.) was saponified in the same manner as the cellulose acetate film 1 and attached to the opposite side of the polarizing film using a polyvinyl alcohol-based adhesive. Thus, the polarizing plate 1 was produced.

[Comparative Example 2]
(Surface treatment of the laminated retardation film 1)
The polycarbonate film side of the laminated retardation film 1 was subjected to corona discharge produced by Kasuga Electric Co., Ltd. under the condition of 12 W · min / m ² to impart hydrophilicity.

[Comparative Example 2]
(Preparation of polarizing plate 2)
In the same manner as in Example 3, the laminated retardation film 1 surface-treated in Comparative Example 2 and the saponified Fuji Tac TD80 prepared above were bonded together so as to sandwich the polarizer, and then in an oven at 40 ° C. for 72 hours. Drying curing was performed to prepare the polarizing plate 2. The laminated retardation film 1 was bonded so that the polycarbonate side was in contact with the polarizer. The obtained polarizing plate had a transmittance of 40% and a polarization degree of 99.4%.

[Example 5]
(Durability test of polarizing plate)
When polarizing plates 1 and 2 prepared in Example 2 and Comparative Example 2 were cut into 20 cm × 20 cm and the adhesiveness between the polarizer and the protective film after aging at 60 ° C. and 90% RH for 500 hours was confirmed, While the polarizing plate 1 of the present invention maintained good adhesion, the polarizing plate 2 of the comparative example had peeling at the interface between the polarizer and the polycarbonate at the four corners of the square.

  From the results of Example 4, the polarizing plate 1 using the cellulose acylate film 1 of the present invention has better polarization performance and higher temperature and humidity than the polarizing plate 2 using the laminated retardation film 1 of the comparative example. It turns out that it is excellent in durability.

[Example 6]
As shown in FIG. 3, the polarizing plate on the observer side provided in the 22-inch liquid crystal display device (manufactured by Sharp Corporation) using a VA type liquid crystal cell is peeled off, and the polarizing plate 1 produced in Example 4 is used instead. Was affixed to the observer side via an adhesive such that the cellulose acetate film 1 of the present invention was on the liquid crystal cell side. The transmission axis of the polarizing plate on the observer side and the transmission axis of the polarizing plate on the backlight side were arranged so as to be orthogonal to each other.
It has been found that the polarizing plate of the present invention is preferable because the change in color and contrast depending on the viewing angle is small and the display unevenness is small.

[Example 7]
(Saponification treatment)
On the cellulose acetate film 2 produced in Example 2, 5.2 ml / m ^{2 of the following} composition was applied and dried at 60 ° C. for 10 seconds. The surface of the film was washed with running water for 10 seconds, and air at 25 ° C. was blown to dry the film surface.

(Saponification solution composition)
Isopropyl alcohol 818 parts by weight Water 167 parts by weight Propylene glycol 187 parts by weight Potassium hydroxide 68 parts by weight Surfactant (1) n-C ₁₆ H ₃₃ O (C ₂ H ₄ O) ₁₀ H 12 parts by weight

(Formation of alignment film)
On the cellulose acetate film 2 subjected to saponification treatment, a coating solution having the following composition was applied at 24 ml / m ² with a # 14 wire bar coater. Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 90 ° C. for 150 seconds.
Next, the formed film was rubbed in the direction of 45 ° with the stretching direction of the cellulose acetate film 2 (almost coincident with the slow axis).

(Orientation film coating solution composition)
Modified polyvinyl alcohol of the following formula 20 parts by mass Water 360 parts by mass Methanol 120 parts by mass Glutaraldehyde (crosslinking agent) 1.0 part by mass

(Formation of optically anisotropic layer)
Discotic liquid crystalline molecule (I) of the following formula: 91 parts by mass Ethylene oxide modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.) 9 parts by mass Cellulose acetate butyrate (CAB531-1, Eastman Chemical) 1.5 parts by weight Photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) 3 parts by weight A coating solution prepared by dissolving 1.0 part by weight of a citric ester mixture of the following formula in 214.2 parts by weight of methyl ethyl ketone Was applied in an atmosphere of 25 ° C. with a # 3.6 wire bar coater at 6.2 ml / m ² . This was attached to a metal frame and heated in a constant temperature bath at 140 ° C. for 2 minutes to align the discotic liquid crystalline molecules. Next, using a 120 W / cm high-pressure mercury lamp at 90 ° C., UV irradiation was performed for 1 minute to polymerize the discotic liquid crystalline molecules. Then, it stood to cool to room temperature.

(Preparation of polarizing plate)
A polarizing film was prepared by adsorbing iodine to a stretched polyvinyl alcohol film.
Next, the transparent support side of the produced optical compensation sheet was attached to one side of the polarizing film using a polyvinyl alcohol-based adhesive. The slow axis of the transparent support and the transmission axis of the polarizing film were arranged in parallel.
A commercially available cellulose triacetate film (Fujitac TD80UF, manufactured by Fuji Photo Film Co., Ltd.) was saponified in the same manner as in Example 2, and the other side of the polarizing film (with an optical compensation sheet attached) using a polyvinyl alcohol-based adhesive. Pasted on the side that did not exist).
Thus, the polarizing plate 3 was produced.

(Preparation of bend alignment liquid crystal cell)
A polyimide film was provided as an alignment film on a glass substrate with an ITO electrode, and the alignment film was rubbed. The obtained two glass substrates were faced to each other so that the rubbing directions were parallel to each other, and the cell gap was set to 5.7 μm. A bend-aligned liquid crystal cell was prepared by injecting a liquid crystal compound (ZLI1132, manufactured by Merck & Co., Inc.) having a Δn of 0.1396 into the cell gap.

(Production of liquid crystal display device)
Two produced polarizing plates 3 were attached so as to sandwich the produced bend alignment cell. The optically anisotropic layer of the polarizing plate faced the cell substrate, and the rubbing direction of the liquid crystal cell and the rubbing direction of the optically anisotropic layer facing it were antiparallel. When the liquid crystal display device thus produced was observed while changing the temperature and humidity, the liquid crystal display device using the polarizing plate 3 of the present invention is preferable because the change in the contrast viewing angle and the color viewing angle is small and the display unevenness is small. I understood it.

It is the schematic which shows the example of the polarizing plate of this invention. It is the schematic which shows the example of the liquid crystal display device of this invention. It is a figure which shows one embodiment of the structure which compounded the polarizing plate used in Example 6, and a functional optical film.

Explanation of symbols

1 Upper polarizing plate 2 Upper polarizing plate absorption axis 3 First optical anisotropic layer 4 First optical anisotropic layer slow axis direction 5 Liquid crystal cell upper electrode substrate 6 Upper substrate orientation control direction 7 ... Liquid crystal layer 8 ... Liquid crystal cell lower electrode substrate 9 ... Lower substrate orientation control direction 10 ... Second optical anisotropic layer 1
11 Second optically anisotropic layer 1 direction of slow axis 12 Second optically anisotropic layer 2
DESCRIPTION OF SYMBOLS 13 ... 2nd optically anisotropic layer 2 slow axis direction 14 lower polarizing plate 15 lower polarizing plate absorption axis direction 101 polarizing plate protective film 102 polarizing plate protective film slow axis direction 103 polarizing plate Polarizing film 104 Polarizing film absorption axis direction 105 Polarizing plate protective film 106 Polarizing plate protective film slow axis direction

Claims (12)

Contains a polymer resin which is a cellulose acylate or cycloolefin polymer, and at least one additive having a negative intrinsic birefringence of 0.1 to 20 parts by mass with respect to 100 parts by mass of the polymer resin and, and retardation an extension Shin optical resin film satisfying the following relationship (a) ~ (F), wherein the additive is selected from the group consisting of styrene and / or styrene derivatives and copolymers with other monomers, or A stretched optical resin film, which is polystyrene .
0 nm <Re (546) <300 nm (A)
30 nm <Rth (546) <700 nm (B)
0.1 <Re (480) / Re (546) <1.0 (C)
1.0 <Re (628) / Re (546) <4.0 (D)
0.8 <Rth (480) / Rth (546) <4.0 (E)
0.1 <Rth (628) / Rth (546) <1.2 (F) The stretched optical resin film according to claim 1, wherein the acylate of the cellulose acylate is an alkyl carbonyl ester, an alkenyl carbonyl ester, an aromatic carbonyl ester or an aromatic alkyl carbonyl ester. The cycloolefin polymer is a cycloolefin addition polymer containing a structural unit (a) represented by the following general formula (1) and a structural unit (b) represented by the following general formula (3): The stretched optical resin film described.

[A in Formula (1) ₁ , A ₂ , A _Three , A _Five Are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group, a cycloalkyl group having 4 to 15 carbon atoms, or a halogen atom. A ₁ ~ A _Five A ₁ And A ₂ , A ₁ And A _Three Or A ₂ And A _Five Also included are alkylene groups formed from r represents an integer of 0-2.

[In formula (3), B ₁ ~ B _Four Each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, a halogenated alkyl group, a hydrolyzable silyl group or — (CH ₂ ) Represents a polar group represented by jX, B ₁ ~ B _Four At least one of the hydrolyzable silyl group or — (CH ₂ A polar group represented by jX. Where X is -C (O) OR ¹ Or -OC (O) R ² And R ¹ , R ² Is a substituent selected from an alkyl group having 1 to 10 carbon atoms, an alkenyl group, a cycloalkyl group, an aryl group, or a group consisting of these halogen substituents, and j is an integer of 0 to 3. B ₁ ~ B _Four B ₁ And B _Three Or B ₂ And B _Four An alkylene group formed from B ₁ And B ₂ Or B _Three And B _Four Also included are alkylidenyl groups formed from r represents an integer of 0-2. The copolymer of styrene and / or a styrene derivative and another monomer is a copolymer of styrene and / or a styrene derivative and at least one selected from acrylonitrile, maleic anhydride, methyl methacrylate, and butadiene. The stretched optical resin film according to claim 1. The stretched optical resin film according to any one of claims 1 to 4 , wherein the additive has an absorption maximum in a wavelength region of 200 nm to 400 nm. Angle between the slow axis to the stretching direction of the stretched optical resin film is not more than 5 ° -5 ° or more, and in any one of claims 1 to 5 variation range of the angle in the longitudinal direction is greater than 5 ° The stretched optical resin film described. Stretched optical resin film according to any one of claims 1 to 6 the film thickness of the optical resin film is 40～110Myuemu. Adding an additive having a negative intrinsic birefringence in the optical resin film, the manufacturing method of the stretched optical resin film according to any one of claims 1 to 7, characterized in that drawing the film.   A polarizing plate having a protective film bonded to both sides of a polarizer, wherein at least one of the protective films is the stretched optical resin film according to claim 1. . A liquid crystal display device comprising a liquid crystal cell and two polarizing plates disposed on both sides thereof, wherein at least one polarizing plate is the polarizing plate according to claim 9 . The liquid crystal display device according to claim 10 , wherein the liquid crystal mode is OCB or VA mode. A VA mode liquid crystal display device comprising the polarizing plate according to claim 9 on a backlight side of a cell.

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