JP2008107577A - Coating liquid for forming optical compensation coating film, optical compensation coating film manufactured using the coating liquid, optical element and liquid crystal display device, and method for forming the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating liquid for forming an optical compensation coating film, from which an optical compensation coating film can be inexpensively manufactured without requiring a complicated filming process, to provide a coating liquid for an optical compensation coating film, from which an optical compensation film having characteristics represented by [(n<SB>x</SB>+n<SB>y</SB>)/2-n<SB>z</SB>]×d<0 can be inexpensively manufactured, and to provide an optical element with a low haze having the characteristics of the optical compensation coating film without requiring labor and time for sticking a film or the like. <P>SOLUTION: The coating liquid for an optical compensation coating film comprises (A) cellulose N-substituted carbamate and (B) a monocarboxylic acid ester-based solvent in which the component (A) is soluble, wherein an ester group has a 1-16C alkyl chain. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  Coating liquid for forming an optical compensation coating film that can be suitably used for an optical device such as a liquid crystal display device, or an optical compensation coating film formed using the coating liquid, an optical element, a liquid crystal display device, and these The present invention relates to a forming method.

  Various optical devices such as liquid crystal display devices use various films together with a liquid crystal cell, a polarizer, etc. (in this application, a film is a layer formed directly on another substrate, which is peeled off from the substrate) And a film formed by direct solution casting, melt casting, etc.). In particular, a film for optical compensation for compensating birefringence caused by other components in the apparatus is generally used (for example, for use in applications such as widening the viewing angle and preventing color leakage during black display). Is). As a material for forming such a film for optical compensation, for example, a polymer such as polycarbonate, polyester, polystyrene, polyamide, polyimide, polyethersulfone, etc. is used. ), A stretching process (phase difference imparting), and a bonding process. However, these methods require not only film formation but also labor for pasting the film, and a simpler method has been demanded.

In order to solve these problems, a thin film forming method in which a polyimide paste is applied has been proposed (see, for example, Patent Document 1). However, this method _{is <although} it is possible to form a system having the optical properties of _{n x = n y, n z} > n z those with optical properties of _{n x} ≧ _{n y,} in other words, [ It was not possible to form a film having a negative thickness retardation value represented by (n _x + _ny ) / 2− _nz ] × d.

On the other hand, a polymer compound solution having a functional group capable of photoisomerization is applied, dried, and then irradiated with light to control the orientation of the polymer, or a liquid crystal polymer solution or a liquid crystal polymer melt the coating, after drying, to align the liquid crystal was heat-treated at the glass transition temperature of the polymer, by fixing the orientation by cooling, to form a film having an optical property of n _z> n _x ≧ n _y (For example, refer to Patent Document 2).

  However, in these methods, compared to the formation of a retardation layer by applying a polyimide paste, when a polymer compound having a functional group capable of photoisomerization is used, light irradiation must be performed, and a liquid crystal polymer is used. In some cases, the liquid crystal is generally expensive, resulting in a high cost.

By the way, when a coating film is formed after dissolving the resin to form a coating solution, haze may increase due to the influence of the internal structure, surface shape, etc. of the coating film. When the haze increases, the turbidity causes a problem that the optical characteristics deteriorate.
JP 2001-290023 A JP-A-7-13022

An object of the present invention is to provide a coating solution for forming an optical compensation coating film, which can produce an optical compensation coating film at low cost without requiring a complicated process. Furthermore, an optical compensation coating that has a characteristic of [(n _x + _ny ) / 2−n _z ] × d <0 and can easily produce an optical compensation coating film having a low haze at low cost. An object of the present invention is to provide a film-forming coating liquid, and an optical compensation coating film, an optical element, a liquid crystal display device and the like formed using the coating liquid.

  In order to solve such problems, the present inventors have intensively studied, and as a result, have solved the above problems with a coating solution for forming an optical compensation coating film formed by containing (A) and (B) below. As a result, the inventors have found out that the present invention can be achieved.

(A) Cellulose N-substituted carbamate (B) A monocarboxylic acid ester solvent in which component (A) can be dissolved, wherein the ester group has an alkyl chain having 1 to 16 carbon atoms.

That is, the present invention
It is a coating liquid for forming an optical compensation coating film formed by containing (A) and (B) below (claim 1),
(A) Cellulose N-Substituted Carbamate (B) A monocarboxylic acid ester solvent in which component (A) can be dissolved, wherein the ester group has an alkyl chain having 1 to 16 carbon atoms. The cellulose N -The substituted carbamate has at least one hydroxyl group of cellulose converted to N-substituted carbamate, and at least one hydrogen atom bonded to the nitrogen atom of the carbamate group is selected from the following general formulas (1) to (3) Substituted by a group (substituent bonded to N), and the substituents bonded to N of a plurality of N-substituted carbamate groups are the same or different and are selected from the following general formulas (1) to (3) It is a coating liquid for forming an optical compensation coating film (claim 2), which is a base,

（式中Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５は、同一又は異なって、水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数１〜２０のハロゲン化アルキル基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基、炭素数７〜２０のアラルキル基、炭素数７〜２０のアラルキルオキシ基、炭素数１〜２１のアシルオキシ基、ハロゲン原子、ニトロ基を表す。）

(Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ are the same or different and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or 1 to 20 carbon atoms. Halogenated alkyl groups, C6-C20 aryl groups, C6-C20 aryloxy groups, C7-C20 aralkyl groups, C7-C20 aralkyloxy groups, C1-C21 Represents an acyloxy group, a halogen atom, or a nitro group.)

（式中Ｒ^６、Ｒ^７、Ｒ^８、Ｒ^９、Ｒ^１０、Ｒ^１１、Ｒ^１２は、同一又は異なって、水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数１〜２０のハロゲン化アルキル基、炭素数１〜２１のアシルオキシ基、ハロゲン原子、ニトロ基を表す。）

(Wherein R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² are the same or different and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms. Represents a halogenated alkyl group having 1 to 20 carbon atoms, an acyloxy group having 1 to 21 carbon atoms, a halogen atom, or a nitro group.)

（式中Ｒ^１３、Ｒ^１４、Ｒ^１５、Ｒ^１６、Ｒ^１７、Ｒ^１８、Ｒ^１９は、同一又は異なって、水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数１〜２０のハロゲン化アルキル基、炭素数１〜２１のアシルオキシ基、ハロゲン原子、ニトロ基を表す。）
前記モノカルボン酸エステル系溶媒が、酢酸メチル、酢酸エチル、酢酸ｎ−プロピル、酢酸イソプロピル、酢酸ｎ−ブチル、酢酸イソブチル、酢酸ｓｅｃ−ブチル、酢酸ｔｅｒｔ−ブチル、酢酸ｎ−ペンチル、酢酸ｎ−ヘキシル、酢酸ｎ−ヘプチル、酢酸ｎ−オクチルから選ばれる少なくとも一つである、更には、酢酸ｎ−ブチル、酢酸ｎ−ペンチル、酢酸ｎ−ヘキシルから選ばれる少なくとも一つである、前記光学補償用塗工膜形成用塗工液（請求項３、４）であり、
更に、（Ｃ）エーテル系溶媒を含有して形成されていることを特徴とする前記光学補償用塗工膜形成用塗工液（請求項５）であり、
前記塗工液を塗工、乾燥してなる光学補償用塗工膜、更には、面内の屈折率のうち最大のものをｎ_ｘ、最小のものをｎ_ｙとし、厚み方向の屈折率をｎ_ｚ、膜厚をｄとした時に、以下の数式１を満たすことを特徴とする前記光学補償用塗工膜（請求項６、７）であり、
〔（ｎ_ｘ＋ｎ_ｙ）／２−ｎ_ｚ〕×ｄ＜０ （数式１）
前記塗工液を基板に塗工し塗工基板とした後、該塗工基板を乾燥することを特徴とする、更には、該塗工基板を下限０℃、上限４０℃の範囲の温度で１次乾燥した後、更に、該塗工基板を下限８０℃、上限３００℃で２次乾燥することを特徴とする光学補償用塗工膜の形成方法（請求項８、９）であり、
前記形成方法を用いて形成したことを特徴とする、更にはヘーズが５％以下であることを特徴とする光学素子（請求項１１、１２）であり、
前記光学補償用塗工膜を、制御された複屈折性を有するフィルムの少なくとも一方の面に形成させてなることを特徴とする、更には、制御された複屈折性を有するフィルムが、正の複屈折性を有する材料からなるフィルムであることを特徴とする光学補償フィルム（請求項１３、１４）であり、
基板として制御された複屈折性を有するフィルムを用い、前記光学補償用塗工膜の形成方法により製造したことを特徴とする積層光学補償フィルム（請求項１５）であり、
前記光学補償用塗工膜、光学素子、積層光学補償フィルム、偏光板から選ばれる１以上の構成を備えたことを特徴とする液晶表示装置（請求項１７）である。

(In the formula, R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ are the same or different and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms. Represents a halogenated alkyl group having 1 to 20 carbon atoms, an acyloxy group having 1 to 21 carbon atoms, a halogen atom, or a nitro group.)
The monocarboxylic acid ester solvent is methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, tert-butyl acetate, n-pentyl acetate, n-hexyl acetate. , N-heptyl acetate, n-octyl acetate, and at least one selected from n-butyl acetate, n-pentyl acetate, and n-hexyl acetate. It is a coating liquid for forming a film (claims 3 and 4),
Furthermore, (C) the coating liquid for forming an optical compensation coating film (Claim 5), characterized in that it is formed containing an ether solvent,
The coating film for optical compensation formed by coating and drying the coating solution, and further, the in-plane refractive index is _nx , the smallest is _ny, and the refractive index in the thickness direction is n _z , when the film thickness is d, the optical compensation coating film (Claims 6 and 7), wherein the following numerical formula 1 is satisfied:
[(N _x + n _y ) / 2−n _z ] × d <0 (Formula 1)
The coating liquid is applied to a substrate to form a coated substrate, and then the coated substrate is dried. Further, the coated substrate is heated at a temperature in the range of a lower limit of 0 ° C. and an upper limit of 40 ° C. After the primary drying, the coated substrate is further dried at a lower limit of 80 ° C. and an upper limit of 300 ° C., wherein the optical compensation coating film is formed (Claims 8 and 9).
An optical element characterized in that it is formed by using the forming method, and further haze is 5% or less (claims 11 and 12),
The optical compensation coating film is formed on at least one surface of a film having controlled birefringence, and the film having controlled birefringence is a positive film. An optical compensation film (Claims 13 and 14), which is a film made of a material having birefringence,
A laminated optical compensation film (claim 15), characterized in that it is produced by a method for forming a coating film for optical compensation using a film having controlled birefringence as a substrate.
A liquid crystal display device comprising one or more components selected from the coating film for optical compensation, an optical element, a laminated optical compensation film, and a polarizing plate (Claim 17).

When the coating liquid for forming an optical compensation coating film of the present invention is used, a low haze optical element can be produced without requiring a complicated process, and in particular, [(n _x + _ny ) / 2− _nz ]. Since an optical element having an optical compensation layer of xd <0 can be produced, it is extremely useful industrially.

  Hereinafter, the present invention will be described in detail.

  The cellulose N-substituted carbamate used in the present invention (hereinafter sometimes referred to as component (A)) is made from cellulose obtained from, for example, various wood pulps, cotton linters, cotton lints, and the like, and bases such as pyridine and triethylamine. It can be produced by a known method in which an isocyanate compound is reacted in the presence of a catalyst. In addition, by subjecting the reaction product to partial hydrolysis with an alkali such as sodium hydroxide or potassium hydroxide, one having a controlled N-substituted carbamate conversion rate can be produced. In addition, the base catalyst used at the time of the said reaction can also be used as a solvent. As other solvents at the time of synthesis, amide solvents such as N, N-dimethylformamide and N, N-dimethylacetamide can be suitably used. Furthermore, an inorganic salt such as lithium chloride can be added to improve the solubility of cellulose in a solvent. Examples of the isocyanate compound include compounds represented by the following general formulas (4) to (6).

（式中Ｒ^２０、Ｒ^２１、Ｒ^２２、Ｒ^２３、Ｒ^２４は、同一又は異なって、水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数１〜２０のハロゲン化アルキル基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基、炭素数７〜２０のアラルキル基、炭素数７〜２０のアラルキルオキシ基、炭素数１〜２１のアシルオキシ基、ハロゲン原子、ニトロ基を表す。）

(In the formula, R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are the same or different and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or 1 to 20 carbon atoms. Halogenated alkyl groups, C6-C20 aryl groups, C6-C20 aryloxy groups, C7-C20 aralkyl groups, C7-C20 aralkyloxy groups, C1-C21 Represents an acyloxy group, a halogen atom, or a nitro group.)

（式中Ｒ^２５、Ｒ^２６、Ｒ^２７、Ｒ^２８、Ｒ^２９、Ｒ^３０、Ｒ^３１は、同一又は異なって、水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数１〜２０のハロゲン化アルキル基、炭素数１〜２１のアシルオキシ基、ハロゲン原子、ニトロ基を表す。）

(In the formula, R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , R ³¹ are the same or different and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms. Represents a halogenated alkyl group having 1 to 20 carbon atoms, an acyloxy group having 1 to 21 carbon atoms, a halogen atom, or a nitro group.)

（式中Ｒ^３２、Ｒ^３３、Ｒ^３４、Ｒ^３５、Ｒ^３６、Ｒ^３７、Ｒ^３８は、同一又は異なって、水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数１〜２０のハロゲン化アルキル基、炭素数１〜２１のアシルオキシ基、ハロゲン原子、ニトロ基を表す。）
これらのイソシアネート系化合物は、単独で使用してもよく、２種以上を併用してもよい。

(Wherein R ³² , R ³³ , R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ , R ³⁸ are the same or different and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms. Represents a halogenated alkyl group having 1 to 20 carbon atoms, an acyloxy group having 1 to 21 carbon atoms, a halogen atom, or a nitro group.)
These isocyanate compounds may be used alone or in combination of two or more.

In the present invention, R ²⁰ , R ²¹ , R ²² , R ²³ , and R ²⁴ are the same or different from the viewpoint of availability of the isocyanate compound, and are a hydrogen atom, an alkyl group having 1 to 16 carbon atoms, or a carbon number. An alkoxy group having 1 to 16 carbon atoms, a halogenated alkyl group having 1 to 16 carbon atoms, an aryl group having 6 to 16 carbon atoms, an aryloxy group having 6 to 16 carbon atoms, an aralkyl group having 7 to 16 carbon atoms, and 7 to 7 carbon atoms The isocyanate compound represented by the general formula (4), which is 16 aralkyloxy group, acyloxy group having 1 to 17 carbon atoms, halogen atom or nitro group, is reacted, and at least one hydroxyl group of the cellulose is N-substituted. It is preferred to use a carbamateized cellulose N-substituted carbamate. Or R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , R ³¹ , R ³² , R ³³ , R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ , R ³⁸ are the same or different and hydrogen A general formula which is an atom, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, a halogenated alkyl group having 1 to 16 carbon atoms, an acyloxy group having 1 to 17 carbon atoms, a halogen atom, or a nitro group. It is preferable to use a cellulose N-substituted carbamate obtained by reacting the isocyanate compounds represented by (5) and (6) and at least one hydroxyl group of the cellulose is N-substituted carbamate. R ²⁰ , R ²¹ , R ²² , R ²³ , R ²⁴ are the same or different and are a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or a halogenated group having 1 to 12 carbon atoms. An alkyl group, an aryl group having 6 to 12 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an aralkyloxy group having 7 to 12 carbon atoms, an acyloxy group having 1 to 13 carbon atoms, It is more preferable to use a cellulose N-substituted carbamate in which an isocyanate compound represented by the general formula (4) which is a halogen atom or a nitro group is reacted and at least one of the hydroxyl groups of the cellulose is N-substituted carbamate. . Or R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , R ³¹ , R ³² , R ³³ , R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ , R ³⁸ are the same or different and hydrogen General formula which is an atom, a C1-C12 alkyl group, a C1-C12 alkoxy group, a C1-C12 halogenated alkyl group, a C1-C13 acyloxy group, a halogen atom, and a nitro group It is more preferable to use a cellulose N-substituted carbamate in which the isocyanate compound represented by (5) or (6) is reacted and at least one of the hydroxyl groups of the cellulose is N-substituted carbamate.

  Specific examples of the isocyanate compounds represented by the general formulas (4) to (6) include phenyl isocyanate, o-tolyl isocyanate, m-tolyl isocyanate, p-tolyl isocyanate, 2-ethylphenyl isocyanate, 3-ethyl. Phenyl isocyanate, 4-ethylphenyl isocyanate, 2-propylphenyl isocyanate, 3-propylphenyl isocyanate, 4-propylphenyl isocyanate, 2-butylphenyl isocyanate, 3-butylphenyl isocyanate, 4-butylphenyl isocyanate, 2,3-dimethyl Phenyl isocyanate, 2,4-dimethylphenyl isocyanate, 2,5-dimethylphenyl isocyanate, 2,6-dimethylphenyl isocyanate, 3,4-dimethylphenol Nyl isocyanate, 3,5-dimethylphenyl isocyanate, 2,3-diethylphenyl isocyanate, 2,4-diethylphenyl isocyanate, 2,5-diethylphenyl isocyanate, 2,6-diethylphenyl isocyanate, 3,4-diethylphenyl isocyanate 3,5-diethylphenyl isocyanate, 2,4,6-trimethylphenyl isocyanate, 2-methoxyphenyl isocyanate, 3-methoxyphenyl isocyanate, 4-methoxyphenyl isocyanate, 2-ethoxyphenyl isocyanate, 3-ethoxyphenyl isocyanate, 4 -Ethoxyphenyl isocyanate, 2- (fluoromethyl) phenyl isocyanate, 3- (fluoromethyl) phenyl isocyanate, 4- (full (Romethyl) phenyl isocyanate, 2- (chloromethyl) phenyl isocyanate, 3- (chloromethyl) phenyl isocyanate, 4- (chloromethyl) phenyl isocyanate, 2- (bromomethyl) phenyl isocyanate, 3- (bromomethyl) phenyl isocyanate, 4- (Bromomethyl) phenyl isocyanate, 2- (iodomethyl) phenyl isocyanate, 3- (iodomethyl) phenyl isocyanate, 4- (iodomethyl) phenyl isocyanate, 2- (difluoromethyl) phenyl isocyanate, 3- (difluoromethyl) phenyl isocyanate, 4- (Difluoromethyl) phenyl isocyanate, 2- (dichloromethyl) phenyl isocyanate, 3- (dichloromethyl) phenyl isocyanate, 4- (dichloromethyl) phenyl isocyanate, 2- (dibromomethyl) phenyl isocyanate, 3- (dibromomethyl) phenyl isocyanate, 4- (dibromomethyl) phenyl isocyanate, 2- (diiodomethyl) phenyl isocyanate, 3- (diiodomethyl) phenyl Isocyanate, 4- (diiodomethyl) phenyl isocyanate, 2- (trifluoromethyl) phenyl isocyanate, 3- (trifluoromethyl) phenyl isocyanate, 4- (trifluoromethyl) phenyl isocyanate, 2- (trichloromethyl) phenyl isocyanate, 3 -(Trichloromethyl) phenyl isocyanate, 4- (trichloromethyl) phenyl isocyanate, 2- (tribromomethyl) phenyl isocyanate, 3 (Tribromomethyl) phenyl isocyanate, 4- (tribromomethyl) phenyl isocyanate, 2- (triiodomethyl) phenyl isocyanate, 3- (triiodomethyl) phenyl isocyanate, 4- (triiodomethyl) phenyl isocyanate, 2- Biphenylyl isocyanate, 3-biphenylyl isocyanate, 4-biphenylyl isocyanate, 2-phenoxyphenyl isocyanate, 3-phenoxyphenyl isocyanate, 4-phenoxyphenyl isocyanate, 2′-benzylphenyl isocyanate, 3′-benzylphenyl isocyanate, 4 ′ -Benzylphenyl isocyanate, 2-benzyloxyphenyl isocyanate, 3-benzyloxyphenyl isocyanate, 4-benzyloxyphenyl Nyl isocyanate, 2-acetoxyphenyl isocyanate, 3-acetoxyphenyl isocyanate, 4-acetoxyphenyl isocyanate, 2-fluorophenyl isocyanate, 3-fluorophenyl isocyanate, 4-fluorophenyl isocyanate, 2-chlorophenyl isocyanate, 3-chlorophenyl isocyanate, 4 -Chlorophenyl isocyanate, 2-bromophenyl isocyanate, 3-bromophenyl isocyanate, 4-bromophenyl isocyanate, 2-iodophenyl isocyanate, 3-iodophenyl isocyanate, 4-iodophenyl isocyanate, 2,4-difluorophenyl isocyanate, 2, 5-difluorophenyl isocyanate, 2,6-difluorophenyl isocyanate 3,4-difluorophenyl isocyanate, 3,5-difluorophenyl isocyanate, 2,4-dichlorophenyl isocyanate, 2,5-dichlorophenyl isocyanate, 2,6-dichlorophenyl isocyanate, 3,4-dichlorophenyl isocyanate, 3,5- Dichlorophenyl isocyanate, 2,4-dibromophenyl isocyanate, 2,5-dibromophenyl isocyanate, 2,6-dibromophenyl isocyanate, 3,4-dibromophenyl isocyanate, 3,5-dibromophenyl isocyanate, 2,4-diiodophenyl Isocyanate, 2,5-diiodophenyl isocyanate, 2,6-diiodophenyl isocyanate, 3,4-diiodophenyl isocyanate, 3,5-diiod Phenyl isocyanate, 2,3,4-trifluorophenyl isocyanate, 2,3,4-trichlorophenyl isocyanate, 2,3,4-tribromophenyl isocyanate, 2,3,4-triiodophenyl isocyanate, 2-fluoro- 5-methylphenyl isocyanate, 2-fluoro-6-methylphenyl isocyanate, 3-fluoro-2-methylphenyl isocyanate, 3-fluoro-4-methylphenyl isocyanate, 4-fluoro-2-methylphenyl isocyanate, 4-fluoro- 3-methylphenyl isocyanate, 5-fluoro-2-methylphenyl isocyanate, 2-chloro-5-methylphenyl isocyanate, 2-chloro-6-methylphenyl isocyanate, 3-chloro-2-methylphenol Isocyanate, 3-chloro-4-methylphenyl isocyanate, 4-chloro-2-methylphenyl isocyanate, 4-chloro-3-methylphenyl isocyanate, 5-chloro-2-methylphenyl isocyanate, 2-bromo-5-methyl Phenyl isocyanate, 2-bromo-6-methylphenyl isocyanate, 3-bromo-2-methylphenyl isocyanate, 3-bromo-4-methylphenyl isocyanate, 4-bromo-2-methylphenyl isocyanate, 4-bromo-3-methyl Phenyl isocyanate, 5-bromo-2-methylphenyl isocyanate, 2-iodo-5-methylphenyl isocyanate, 2-iodo-6-methylphenyl isocyanate, 3-iodo-2-methylphenyl isocyanate, 3- Iodo-4-methylphenyl isocyanate, 4-iodo-2-methylphenyl isocyanate, 4-iodo-3-methylphenyl isocyanate, 5-iodo-2-methylphenyl isocyanate, 2-nitrophenyl isocyanate, 3-nitrophenyl isocyanate, 4-nitrophenyl isocyanate, 1-naphthyl isocyanate, 2-naphthyl isocyanate, 1-methyl-2-naphthyl isocyanate, 2-methyl-1-naphthyl isocyanate, 1-methoxy-2-naphthyl isocyanate, 2-methoxy-1-naphthyl Isocyanate, 1- (trifluoromethyl) -2-naphthyl isocyanate, 2- (trifluoromethyl) -1-naphthyl isocyanate, 1- (trichloromethyl) -2-naphthyl isocyanate 2- (trichloromethyl) -1-naphthyl isocyanate, 1- (tribromomethyl) -2-naphthyl isocyanate, 2- (tribromomethyl) -1-naphthyl isocyanate, 1- (triiodomethyl) -2-naphthyl isocyanate 2- (triiodomethyl) -1-naphthyl isocyanate, 1-acetoxy-2-naphthyl isocyanate, 2-acetoxy-1-naphthyl isocyanate, 1-fluoro-2-naphthyl isocyanate, 2-fluoro-1-naphthyl isocyanate, 1-chloro-2-naphthyl isocyanate, 2-chloro-1-naphthyl isocyanate, 1-bromo-2-naphthyl isocyanate, 2-bromo-1-naphthyl isocyanate, 1-iodo-2-naphthyl isocyanate, 2-iodo-1 -Naphth Isocyanate, 1-nitro-2-naphthyl isocyanate, 2-nitro-1-naphthyl isocyanate, and the like. The cellulose N-substituted carbamates obtained by reacting these and the isocyanate compounds may be used alone or in combination of two or more.

  Cellulose has three hydroxyl groups per glucose residue, which is its structural unit. Therefore, when these hydroxyl groups are substituted, the degree of substitution per glucose residue (hereinafter referred to as DS) is 3 at maximum. In the present invention, the lower limit of DS is preferably 0.05, more preferably 1.0, still more preferably 1.9, and the upper limit is preferably 3, more preferably 2.95, and even more preferably 2.9. It is. When DS is lower than 0.05, it tends to be difficult to dissolve in a solvent. In the present invention, two or more cellulose N-substituted carbamates having different DSs may be used in combination, or may be used alone.

  Furthermore, the lower limit of the number average molecular weight of the component (A) is preferably 5000, more preferably 8000, and still more preferably 10,000, and the upper limit is preferably 500,000, more preferably 300,000, still more preferably 200,000. When the number average molecular weight is less than 5,000, the coating film strength tends to be reduced, and when the number average molecular weight is more than 500,000, it tends to be difficult to dissolve in a solvent (hereinafter sometimes referred to as component (B)). The number average molecular weight is a value measured by a gel permeation chromatography (GPC) method. In the present invention, two or more cellulose N-substituted carbamates having different number average molecular weights may be used in combination, or may be used alone.

  Hereinafter, the coating liquid for forming an optical compensation coating film of the present invention (hereinafter sometimes simply referred to as a coating liquid) will be described. The coating liquid is a monocarboxylic acid ester solvent in which (A) cellulose N-substituted carbamate, (B) (A) component can be dissolved, and the ester group has an alkyl chain having 1 to 16 carbon atoms. A solvent.

  The solvent of the component (B) is not particularly limited as long as it is a monocarboxylic acid ester solvent in which the component (A) can be dissolved and the ester group has an alkyl chain having 1 to 16 carbon atoms. Is an ester of a monocarboxylic acid such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, caproic acid, heptanoic acid, caprylic acid, nonanoic acid, capric acid, etc. Have an alkyl chain having 1 to 16 carbon atoms.

  These monocarboxylic acid esters may be used alone or in combination of two or more.

  In this invention, it is preferable to use the monocarboxylic acid ester in which an ester group has a C1-C16 alkyl chain from a dry viewpoint after coating, and an ester group has a C1-C12 alkyl chain. It is more preferable to use a monocarboxylic acid ester, and it is more preferable to use a monocarboxylic acid ester in which the ester group has an alkyl chain having 1 to 8 carbon atoms.

  Specific examples of these monocarboxylic acid esters include methyl formate, ethyl formate, n-propyl formate, isopropyl formate, n-butyl formate, isobutyl formate, sec-butyl formate, tert-butyl formate, n-pentyl formate, N-hexyl formate, n-heptyl formate, n-octyl formate, n-nonyl formate, n-decyl formate, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-acetate Butyl, tert-butyl acetate, n-pentyl acetate, n-hexyl acetate, n-heptyl acetate, n-octyl acetate, n-nonyl acetate, n-decyl acetate, methyl propionate, ethyl propionate, n-propyl propionate , Isopropyl propionate, n-butyl propionate, isobutyl propionate Sec-butyl propionate, tert-butyl propionate, n-pentyl propionate, n-hexyl propionate, n-heptyl propionate, n-octyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, N-butyl butyrate, isobutyl butyrate, sec-butyl butyrate, tert-butyl butyrate, n-pentyl butyrate, n-hexyl butyrate, n-heptyl butyrate, n-octyl butyrate, methyl isobutyrate, ethyl isobutyrate, n-isobutyrate Propyl, isopropyl isobutyrate, n-butyl isobutyrate, isobutyl isobutyrate, sec-butyl isobutyrate, tert-butyl isobutyrate, n-pentyl isobutyrate, n-hexyl isobutyrate, n-heptyl isobutyrate, n-isobutyrate Octyl, methyl valerate, ethyl valerate, n-pro valerate , Isopropyl valerate, n-butyl valerate, isobutyl valerate, sec-butyl valerate, tert-butyl valerate, n-pentyl valerate, n-hexyl valerate, methyl isovalerate, ethyl isovalerate, N-propyl isovalerate, isopropyl isovalerate, n-butyl isovalerate, isobutyl isovalerate, sec-butyl isovalerate, tert-butyl isovalerate, n-pentyl isovalerate, isovaleric n- Hexyl, methyl caproate, ethyl caproate, n-propyl caproate, isopropyl caproate, n-butyl caproate, isobutyl caproate, sec-butyl caproate, tert-butyl caproate, methyl heptanoate, heptanoic acid Ethyl, n-propyl heptanoate, isopropyl heptanoate, n-butyl heptanoate, Isobutyl butanoate, sec-butyl heptanoate, tert-butyl heptanoate, methyl caprylate, ethyl caprylate, n-propyl caprylate, isopropyl caprylate, n-butyl caprylate, isobutyl caprylate, sec-caprylate Examples include butyl, tert-butyl caprylate, methyl nonanoate, ethyl nonanoate, n-propyl nonanoate, isopropyl nonanoate, methyl caprate, ethyl caprate, n-propyl caprate, isopropyl caprate, and the like.

  From the viewpoint of both the solubility of the component (A) and the drying property after coating, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, tert-acetate -Butyl, n-pentyl acetate, n-hexyl acetate, n-heptyl acetate and n-octyl acetate are particularly preferred. Furthermore, n-butyl acetate, n-pentyl acetate, n-hexyl acetate, particularly n-pentyl acetate, and n-hexyl acetate are preferred from the viewpoint that haze is easily lowered.

In the present invention, another solvent (hereinafter sometimes referred to as the component (C)) can be used in combination with the solvent of the component (B). The solvent for the component (C) is not particularly limited as long as the component (A) is soluble when mixed with the component (B). Specific examples include benzene, toluene, o- Hydrocarbon solvents such as isomer mixtures of xylene, m-xylene, p-xylene, ethylbenzene, isopropylbenzene, diethylbenzene; methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl Alcohol solvents such as -1-propanol, furfuryl alcohol, benzyl alcohol; ethyl ether, isopropyl ether, 1,3-dioxolane, 1,4-dioxane, tetrahydropyran, tetrahydrofuran, 1,2-dimethoxyethane, ethylene glycol monomethyl Ether, ethylene glycol mono Ether solvents such as tilether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether; ketone solvents such as acetone, 2-butanone, 4-methyl-2-pentanone, cyclohexanone; methylene chloride, chloroform, carbon tetrachloride, 1, 2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, 1,1,1,2-tetrachloroethane, 1,1,2,2-tetrachloroethane, pentachloroethane, hexachloroethane, 1- Chloropropane, 2-chloropropane, 1,1-dichloropropane, 1,2-dichloropropane, 1,3-dichloropropane, 2,2-dichloropropane, 1,2,3-trichloropropane, chlorobenzene, 1,2-di Chlorobenzene, 1,3-dichloro Halogen solvents such as benzene, 1,4-dichlorobenzene, 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, 1,3,5-trichlorobenzene; ethylene glycol monomethyl ether acetate, ethylene glycol mono Glycol ester solvents such as ethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate; amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, 1-methyl-2-pyrrolidinone; Examples include amine solvents such as pyrrolidine, piperidine, and pyrrole. Among these, ether solvents, particularly ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether are represented by ( _nx + _ny ) / 2- _nz. This is preferable because the absolute value of is easily increased. These solvents can be used alone or in combination of two or more.

  In the present invention, the amount of the solvent is preferably such that the ratio of the component (A) to the total weight of the component (A), the component (B), and the component (C) is 1% by weight lower limit and 70% by weight upper limit. More preferably, the lower limit is 2% by weight and the upper limit is 60% by weight, and the lower limit is 3% by weight and the upper limit is 50% by weight. When the proportion of the component (A) is less than 1% by weight, the coating film thickness tends to be thin and the required film thickness tends to be difficult to obtain, and when it is greater than 70% by weight, the viscosity of the coating liquid increases. , Workability tends to be inferior.

  Further, the component (B) is preferably used in such a range that the ratio of the component (B) to the total weight of the component (B) and the component (C) is 30% by weight lower limit and 100% by weight upper limit, More preferably, the upper limit is 100% by weight, and the lower limit is 50% by weight, and the upper limit is 100% by weight. When the proportion of the component (B) is less than 30% by weight, the haze of the coating film tends to increase.

  Next, resins that can be added for the purpose of modifying the properties of the coating film of the present invention will be described. The resins that can be added include polycarbonate resin, acrylic resin, polyester resin, polystyrene resin, polyolefin resin, polyamide resin, polyimide resin, polyvinyl alcohol resin, polyvinyl acetal resin, polyethersulfone resin, polyarylate resin, epoxy. Resins, silicone resins, phenol resins, urethane resins and the like are exemplified, but these can be added within a range that does not impair the object and effect of the present invention.

  Next, additives that can be added for the purpose of modifying the properties of the coating film and coating solution of the present invention will be described. Additives include antioxidants (eg, hindered phenols such as IRGANOX 1010, IRGANOX 1135, IRGANOX 1330, etc. manufactured by Ciba Specialty Chemicals), processing stabilizers (eg, HP-136, IRGANOX manufactured by Ciba Specialty Chemicals). E201, IRGAFOS 168, etc.), light stabilizers (eg, hindered amines such as Sanol LS-765 and Sanol LS-770 manufactured by Sankyo Lifetech), ultraviolet absorbers (eg, TINUVIN P, TINUVIN 213 manufactured by Ciba Specialty Chemicals) Benzotriazoles such as TINUVIN 326), adhesion improvers (eg, silane compounds such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane) Pulling agent), silanol condensation catalyst (for example, aluminum tris (ethyl acetoacetate) manufactured by Kawaken Fine Chemicals, aluminum chelate M, etc.), plasticizer (for example, esters such as di-2-ethylhexyl phthalate, diisobutyl adipate) And surfactants (for example, fluorine compounds such as Fluorad FC-430 and Fluorad FC-4430 manufactured by Sumitomo 3M), antistatic agents (for example, IRGASTAT P18 and IRGASTAT P22 manufactured by Ciba Specialty Chemicals), and the like. These can be added as long as the objects and effects of the present invention are not impaired.

  The coating liquid of the present invention can be obtained, for example, by mixing the above-mentioned components at a temperature not lower than the melting point of the solvent and not higher than the boiling point, after standing, or by stirring and mixing.

  Next, the substrate on which the coating liquid for forming an optical compensation coating film is applied will be described. Various substrates can be used as the substrate, but it is preferable that the substrate is transparent particularly from the viewpoint of use. Specific examples of compounds used for the substrate include polycarbonate polymers; polyacrylic esters such as polymethyl acrylate and polymethyl methacrylate; two bases such as adipic acid, phthalic acid, isophthalic acid, and terephthalic acid. Polyester polymers obtained by condensation of acid with glycols such as ethylene glycol, diethylene glycol, propylene glycol, tetramethylene glycol, neopentyl glycol or the like, or ring-opening polymerization of lactones; styrene such as polystyrene and poly (α-methylstyrene) Polymers; Copolymers of acrylic esters and styrene; Polyolefin polymers such as polyethylene, polypropylene, norbornene resins, cycloolefin polymers, polyisoprene hydrogenated products, polybutadiene hydrogenated products; Cellulosic resins such as cellulose; polyamides such as nylon 6 and nylon 66; polyimides; polyamideimides; polyvinyl alcohol; polyvinyl chloride; polysulfone; polyethersulfone; polyarylate; Examples include compounds described in pamphlets.

  In addition, these materials are formed by, for example, a solution casting method, a melt casting method, an extrusion method, a calendering method, and the like, and are contracted by using a non-stretching method, a uniaxial stretching method, a biaxial stretching method, or a shrinkable film. It can be stretched by a method or the like and used as a substrate. On the other hand, a glass plate, a color filter, a liquid crystal cell, or the like can be used as the substrate. The substrate used in the present invention may be formed by coating a coating solution (either single-sided coating or double-sided coating) to form a coating film, and then incorporating this laminated state into various optical devices as it is (according to this method) An optical element can be formed more easily, for example, a polarizing plate having an optical compensation function attached to a polarizer as a protective film, or a coating film from a substrate. The film itself may be peeled off and incorporated into various optical devices (this method is inferior to the former in terms of simplicity at the time of production, but it is also excellent in convenience by using a transfer method or the like. Since the solvent at the time does not cause damage to the optical device, the selection range of the coating liquid can be expanded.) Next, a film having controlled birefringence (in the present invention, a coating film is formed on a substrate, and this laminated structure is used as an optical element or a part thereof as it is. (When the refraction is controlled, the substrate is represented in this way). As a film having controlled birefringence, various films can be used as long as the birefringence is controlled to a desired birefringence, regardless of whether the film is positive birefringence, negative birefringence, or zero birefringence. In particular, from the viewpoint of viewing angle compensation, a film made of a material having positive birefringence can be preferably used. Specific examples of materials having positive birefringence include polycarbonate, polyethylene terephthalate, polypropylene, norbornene resin, cycloolefin polymer, cellulose resin, polyimide, polyvinyl alcohol, polysulfone, polyethersulfone, polyarylate, and the like. It is done. Incidentally, when a film having a positive birefringence is subjected to general longitudinal uniaxial stretching or the like to form a film, it has optically positive uniaxiality and its optical axis is parallel to the film surface. When an A plate is used and used together with the optical compensation coating film of the present invention, an optical compensation function such as reducing light leakage in the dark state of the liquid crystal display device is manifested and useful.

Preferred in-plane retardation of a film having controlled birefringence ((n _{xf −ny f} ) × d _f , where n _{xf is the} largest in the in-plane refractive index of the film, and x is the smallest n _yf , when the film thickness is d _f (nm)), when measured with 590 nm light, the in-plane retardation is preferably controlled such that the lower limit is 0 nm and the upper limit is 600 nm, and the lower limit is 0 nm and the upper limit is It is more preferable that the thickness is controlled to be 500 nm, and it is more preferable that the lower limit is 0 nm and the upper limit is 400 nm. When the in-plane retardation is larger than 600 nm, the retardation compensation effect of the laminated optical compensation film formed by forming the optical compensation coating film of the present invention on the film surface tends to be lowered.

  Next, the method for forming the optical compensation coating film of the present invention will be described. The coating film for optical compensation can be suitably prepared on a substrate by applying the coating liquid of the present invention to one or both sides of the substrate to form a coated substrate, and then drying the coated substrate. As coating methods, gravure roll coating method, Mayer bar coating method, doctor blade coating method, reverse roll coating method, dip coating method, air knife coating method, calendar coating method, skies coating method, kiss coating method, bar coating method , Slot die coating method, spin coating method and the like.

  As a drying method, the coated substrate is left (air dried) in an inert gas such as air or nitrogen, a method of heat drying in a hot air oven, an infrared heating furnace, or the like, and vacuum drying with a vacuum dryer or the like. It can carry out by the method to carry out, etc. or combining these.

As the drying temperature condition, either constant temperature or multistage temperature increase can be used. In the case of constant temperature, a temperature range of a lower limit of −30 ° C. and an upper limit of 300 ° C. is preferable, a lower limit of 0 ° C. and an upper limit of 280 ° C. are more preferable, and a lower limit of 10 ° C. and an upper limit of 260 ° C. are more preferable. When the drying temperature is lower than −30 ° C., the drying time tends to be longer, and when it is higher than 300 ° C., the coating film and the substrate tend to be thermally deteriorated. Although the above temperature range is relatively wide, in order to increase the absolute value of the value represented by (n _x + n _y ) / 2− _nz , it is desirable to perform at a low temperature close to the lower limit (painting). The formation of the internal structure of the film proceeds more). However, since the drying time becomes very long at such a low temperature, the range in which a desired value represented by ( _nx + _ny ) / 2- _nz can be obtained in consideration of the boiling point of the solvent. It is necessary to select the temperature at. Although such constant temperature drying can be used, in order to dry effectively, it is preferable to raise the temperature in multiple stages, and from the economical viewpoint, primary drying and secondary drying are particularly preferable.

When performing two-stage drying, the primary drying preferably has a temperature range of a lower limit of 0 ° C and an upper limit of 40 ° C, more preferably a lower limit of 5 ° C and an upper limit of 35 ° C, and even more preferably a lower limit of 10 ° C and an upper limit of 30 ° C. The drying time is preferably 3 minutes or more. The primary drying is effective for the foundation formation of the internal structure of the coating film for increasing the absolute value of the value represented by (n _x + _ny ) / 2− _nz . When the primary drying temperature is lower than 0 ° C., the drying time required for the basic formation of the inner structure of the coating film tends to be longer. When the primary drying temperature is higher than 40 ° C., it is expressed by (n _x + _ny ) / 2− _nz. There is a tendency that it becomes difficult to form the foundation of the internal structure of the coating film necessary for increasing the absolute value of the value to be determined.

In secondary drying, a temperature range of a lower limit of 80 ° C. and an upper limit of 300 ° C. is preferred, a lower limit of 90 ° C. and an upper limit of 280 ° C. are more preferred, and a lower limit of 100 ° C. and an upper limit of 260 ° C. are more preferred. In addition to completely removing the solvent, the secondary drying has developed the foundation of the internal structure of the coating film formed by the primary drying, and actually has a value expressed by (n _x + _ny ) / 2− _nz. This is effective for increasing the absolute value. When the secondary drying temperature is lower than 80 ° C., the establishment of the internal structure of the coating film tends to be insufficient, and when it is higher than 300 ° C., thermal deterioration of the coating film or the substrate tends to occur.

  Further, in the present invention, the coating liquid is coated on a substrate to form a coated substrate, and then the coating film is annealed by exposure to the vapor of the component (B) and / or the component (C) and further dried. A method for forming a compensation coating film may also be used.

  Annealing is preferably performed in order to improve the leveling property of the coating film and to relieve stress. For example, it is effective for reducing in-plane retardation and reducing in-plane retardation. In the present invention, the annealing is preferably performed by leaving the coating film on the coating substrate in the vapor of the component (B) and / or the component (C) horizontally. The temperature during annealing can be variously set, but the lower limit is preferably −30 ° C. and the upper limit [(B) component or (C) component, whichever is the higher boiling point (° C.)], and the lower limit is −15 ° C. and the upper limit [( B) component or (C) component, whichever is higher boiling point (° C.)-5 ° C.], more preferably lower limit 0 ° C., upper limit [(B) component or (C) component, whichever is higher boiling point (° C. -10 ° C] is more preferred. If the temperature during annealing is lower than −30 ° C., the annealing time tends to be longer, and if the temperature during annealing is higher than the higher boiling point (° C.) of either the component (B) or the component (C), the coating film There is a tendency that flow out of the substrate tends to occur. The pressure at the time of annealing can be set variously and can be performed under atmospheric pressure, pressurization, or reduced pressure, but atmospheric pressure is preferable in terms of workability.

  The coating film and the optical compensation coating film thus formed may be incorporated into various optical devices as an optical element together with the substrate, or after being peeled off from the substrate, various optical devices using only the film as an optical element. It may be used by incorporating it in

On the other hand, an optical compensation for coated films of the present invention, largest of the n _x of the in-plane refractive _index, minimum one of the n _y, the refractive index in the thickness direction n _z, thickness and d Sometimes it is preferable to have the characteristics [(n _x + n _y ) / 2−n _z ] × d <0. Further, when the thickness of the optical compensation for coated film and d (nm), the in-plane retardation _is represented by _{(n x -n y) × d} , the thickness retardation, _[(n x _{+ n} y) / 2- _nz ] × d, but the in-plane retardation is preferably 0 nm lower limit and 300 nm upper limit, more preferably 0 nm lower limit and 200 nm upper limit, and more preferably 0 nm lower limit and 100 nm upper limit when measured with 590 nm light. If the in-plane retardation is larger than 300 nm, it tends to be difficult to compensate for the retardation due to birefringence in a liquid crystal cell or the like. In addition, the thickness retardation is preferably lower limit −1000 nm and upper limit −1 nm, more preferably lower limit −800 nm and upper limit −10 nm, and further preferably lower limit −600 nm and upper limit −20 nm in the measurement with 590 nm light. If the thickness phase difference is smaller than −1000 nm, it tends to be difficult to compensate for the phase difference due to birefringence in a liquid crystal cell or the like.

Next, the laminated optical compensation film of the present invention will be described. The laminated optical compensation film of the present invention is formed by forming the optical compensation coating film on at least one surface of a film having controlled birefringence, and particularly as described above, controlled birefringence. The film having the property is preferably formed from a material having positive birefringence.

Next, the polarizing plate of the present invention will be described. As a polarizing plate, for example, a protective film is bonded to both surfaces of a polarizer using an adhesive such as a polyester adhesive, a polyacrylic adhesive, an epoxy adhesive, a cyanoacrylic adhesive, or a polyurethane adhesive. And the like. Examples of polarizers include polarizers made by adsorbing and orienting iodine and / or dichroic dyes on hydrophilic polymer films, and polyenes formed by dehydration treatment of polyvinyl alcohol-based films. Examples include polarizers and polyvinyl chloride films prepared by dehydrochlorination treatment to form polyene and orientation. Examples of the hydrophilic polymer film used for the polarizer include a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, a saponified film of an ethylene-vinyl acetate copolymer, and the like. As the protective film, those exemplified above as the substrate can be used. In particular, the aforementioned laminated optical compensation film can also be used (in this case, in addition to the function of the polarizing plate, the function of optical compensation can be added to the polarizing plate). When the laminated optical compensation film of the present invention is used as a protective film, it can be used on both sides of a polarizer, the laminated optical compensation film of the present invention is used on one side, and the substrate or the like is simply placed on the opposite side. It can also be used. Further, the optical compensation coating film of the present invention can be separately provided after the production of these polarizing plates.

  Next, the liquid crystal display device of the present invention will be described. Examples of the liquid crystal display device include a display device configured in the order of light source / light guide plate / light diffusion film / lens film / brightness enhancement film / polarizing plate / liquid crystal cell / polarizing plate. By mounting the laminated optical compensation film of the present invention on the side and / or the outgoing light side, and / or by mounting the polarizing plate of the present invention on the polarizing plate on the incident light side and / or outgoing light side of the liquid crystal cell. The liquid crystal display device can be obtained. Examples of the liquid crystal cell method include a VA (Vertical Alignment) method, an IPS (In-Plane Switching) method, an OCB (Optically Compensated Birefringence) method, and the like.

  The optical compensation coating film of the present invention, the coating liquid for forming an optical compensation coating film, the optical element and laminated optical compensation film produced using them are VA, IPS, OCB, etc. It can be used for widening the viewing angle of liquid crystal display devices using liquid crystal cells. The IPS method is particularly preferable in order to sufficiently exhibit the performance of the optical characteristics of the coating film for optical compensation in the present invention. The optical compensation coating film, the coating film-forming coating liquid, the optical element produced using them, and the laminated optical compensation film are used in video, camera, mobile phone, personal computer, television, monitor, automobile It can be used suitably for liquid crystal display device manufacturing parts such as instrument panels.

  Examples are shown below to describe the present invention in more detail, but the present invention is not limited to these examples.

(1) The three-dimensional refractive indexes _{[(n x, n y, n} z) or _{(n xf, n yf, n} zf) ] using the calculated Oji Scientific Instruments Ltd. automatic birefringence meter KOBRA-WR of under 25 ° C. Was measured with 590 nm light, and the three-dimensional refractive index was calculated. From the results obtained, it was determined by an in-plane retardation _(n x -n _y) × d or _{(n xf -n yf) × d} f. It was also determined by the thickness retardation _{[(n x + n y) /} 2-n z ] × d or _{[(n xf + n yf) /} 2-n zf ] × _{d f.} However, when the phase difference was measured with the slow axis as the tilt center axis, when the phase difference increased with the tilt angle, the following method was used in combination to determine the sign of the phase difference. Overlay the polycarbonate λ / 4 plate on the manufactured optical element and attach it to the automatic birefringence meter KOBRA-WR so that the orientation angle of the λ / 4 plate is 0 ± 1 degree, and then the slow axis is the center of tilt The phase difference was measured with 590 nm light at 25 ° C. with the axis. If the measurement result is higher than the phase difference of the single λ / 4 plate, it is considered that the phase difference of the single optical element is also increasing in the positive direction as the tilt angle increases, and is lower than the phase difference of the single λ / 4 plate. In this case, it is assumed that the phase difference of the optical element alone decreases in the negative direction as the tilt angle increases, and a positive / negative sign is given to the phase difference of the optical element alone measured previously, and the three-dimensional refractive index is set. Calculated. From the results obtained, it was determined by an in-plane retardation _(n x -n _y) × d or _{(n xf -n yf) × d} f. It was also determined by the thickness retardation _{[(n x + n y) /} 2-n z ] × d or _{[(n xf + n yf) /} 2-n zf ] × _{d f.}

(2) Haze measurement Measured according to JIS K 7136.

(Synthesis Example 1) Synthesis of cellulose N-phenyl carbamate (1) Cellulose (manufactured by Asahi Kasei Chemicals) was vacuum-dried at 60 ° C for 7 hours in a 500 ml four-necked flask equipped with a cooling tube, a nitrogen introduction tube, a stirrer, and a thermometer Avicel TG-F20) (3.0 g) was added, 300 ml of pyridine was added to form a suspension, and then 23.1 g of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added. Nitrogen was introduced, and the temperature was raised to 110 ° C. with stirring, followed by reaction for 7 hours. Then, after cooling to 25 degreeC, the reaction liquid was dripped in 1200 ml of ethanol, and the precipitation was produced | generated. After separation by filtration, the obtained polymer was dissolved by adding 90 ml of acetone, and then dropped into 1200 ml of pure water to cause precipitation. After separation by filtration, washing with water and vacuum drying at 60 ° C. for 8 hours, the polymer was put into a Soxhlet extractor. After performing Soxhlet extraction with methanol 20 times and vacuum-drying at 25 ° C. for 8 hours, 5.7 g of cellulose N-phenylcarbamate (1) was obtained (hereinafter sometimes referred to as synthetic product (1)). .) DS of the synthesized product (1) was 3 as a result of proton NMR analysis. In addition, DS was determined by comparing the chemical shift (3.4 to 5.5 ppm) area of proton derived from the cellulose skeleton with the chemical shift (6.7 to 7.8 ppm) area of the proton of the phenyl group.

(Example 1)
To 1.0 g of the synthetic product (1), 4.0 g of ethyl acetate was added and dissolved at 25 ° C. Next, this coating solution was coated on a glass substrate having a thickness of 150 μm (average refractive index: 1.52, in-plane retardation: 0 nm, thickness retardation: 1 nm) using a bar coater to obtain a coated substrate. Thereafter, the coated substrate was dried in air at 35 ° C. for 25 minutes, and further dried in air at 100 ° C. for 1 minute to produce an optical element. The coating thickness after drying (d (nm)) was determined by measuring the thickness of the entire optical element and subtracting the thickness of the glass substrate. Next, physical properties of the optical element obtained as described above were measured. The results are shown in Table 1.

  In addition, although the coating film formation process was confirmed using the polarizing microscope, formation of the liquid crystal phase was not confirmed through the drying process. Further, differential scanning calorimetry (DSC analysis) of the coated film was performed, but no phase transition to the liquid crystal phase was observed.

(Example 2)
To 0.5 g of the synthesized product (1), 4.0 g of n-butyl acetate and 0.5 g of ethylene glycol monobutyl ether acetate were added and dissolved at 25 ° C. Next, this coating solution was coated on a glass substrate having a thickness of 150 μm (average refractive index: 1.52, in-plane retardation: 0 nm, thickness retardation: 1 nm) using a bar coater to obtain a coated substrate. Thereafter, the coated substrate was dried in air at 25 ° C. for 25 minutes, and further dried in air at 250 ° C. for 10 minutes to produce an optical element. The coating thickness after drying (d (nm)) was determined by measuring the thickness of the entire optical element and subtracting the thickness of the glass substrate. Next, physical properties of the optical element obtained as described above were measured. The results are shown in Table 1.

(Example 3)
To 0.6 g of the synthesized product (1), 3.91 g of n-butyl acetate and 0.49 g of ethylene glycol monobutyl ether were added and dissolved at 25 ° C. Next, this coating solution was coated on a glass substrate having a thickness of 150 μm (average refractive index: 1.52, in-plane retardation: 0 nm, thickness retardation: 1 nm) using a bar coater to obtain a coated substrate. Thereafter, the coated substrate was dried in air at 25 ° C. for 17 minutes, and further dried in air at 100 ° C. for 5 minutes to produce an optical element. The coating thickness after drying (d (nm)) was determined by measuring the thickness of the entire optical element and subtracting the thickness of the glass substrate. Next, physical properties of the optical element obtained as described above were measured. The results are shown in Table 1.
Example 4
To 0.6 g of the synthetic product (1), 3.91 g of n-pentyl acetate and 0.49 g of ethylene glycol monobutyl ether were added and dissolved at 25 ° C. Next, this coating solution was coated on a glass substrate having a thickness of 150 μm (average refractive index: 1.52, in-plane retardation: 0 nm, thickness retardation: 1 nm) using a bar coater to obtain a coated substrate. Then, this coated substrate was dried in air at 25 ° C. for 35 minutes, and further dried in air at 160 ° C. for 5 minutes to produce an optical element. The coating thickness after drying (d (nm)) was determined by measuring the thickness of the entire optical element and subtracting the thickness of the glass substrate. Next, physical properties of the optical element obtained as described above were measured. The results are shown in Table 1.

（比較例１）
合成品（１）０．６ｇに１，３−ジオキソラン４．４ｇを加え、２５℃下で溶解した。次に、この塗工液をバーコーターを用いて１５０μｍ厚のガラス基板（平均屈折率：１．５２，面内位相差：０ｎｍ，厚み位相差：１ｎｍ）に塗工し塗工基板とした。その後、この塗工基板を２５℃で２５分間、空気中で乾燥し、更に、１００℃で１分間、空気中で乾燥して光学素子を作製した。乾燥後の塗工膜厚（ｄ（ｎｍ））は、光学素子全体の厚みを測定し、ガラス基板の厚みを差し引くことにより求めた。その結果、厚みは１００００ｎｍであった。次に、上記によって得られた光学素子の物性測定を行った結果、面内位相差は１ｎｍ、厚み位相差は−６０ｎｍ、ヘーズは１０．０％であり、高ヘーズであった。

(Comparative Example 1)
4.4 g of 1,3-dioxolane was added to 0.6 g of the synthesized product (1) and dissolved at 25 ° C. Next, this coating solution was coated on a glass substrate having a thickness of 150 μm (average refractive index: 1.52, in-plane retardation: 0 nm, thickness retardation: 1 nm) using a bar coater to obtain a coated substrate. Then, this coated substrate was dried in air at 25 ° C. for 25 minutes, and further dried in air at 100 ° C. for 1 minute to produce an optical element. The coating thickness after drying (d (nm)) was determined by measuring the thickness of the entire optical element and subtracting the thickness of the glass substrate. As a result, the thickness was 10,000 nm. Next, as a result of measuring the physical properties of the optical element obtained as described above, the in-plane retardation was 1 nm, the thickness retardation was −60 nm, the haze was 10.0%, and the haze was high.

(Example 5)
A 41 μm thick cellulose acetate film (in-plane retardation: 1 nm, thickness retardation: 30 nm) was used in place of the glass substrate, and a 10000 nm coating film was formed thereon to produce a laminated optical compensation film. The same operation as in Example 3 was performed. As a result of measuring the physical properties of the obtained laminated optical compensation film, the in-plane retardation was 2 nm and the thickness retardation was −60 nm.

(Example 6)
Other than using a cycloolefin polymer film (in-plane retardation: 215 nm, thickness retardation: 100 nm) of 87 μm thickness instead of the glass substrate, and forming a 10000 nm coating film thereon to produce a laminated optical compensation film The same operation as in Example 3 was performed. As a result of measuring the physical properties of the obtained laminated optical compensation film, the in-plane retardation was 210 nm and the thickness retardation was 15 nm.

(Example 7)
A polyvinyl alcohol film was impregnated with iodine and stretched to prepare a polarizer. A cellulose acetate film having a thickness of 80 μm was bonded to one side of the polarizer using a polyacrylic adhesive. Further, the laminated optical compensation film produced in Example 5 was bonded to the opposite surface of the polarizer using a polyacrylic adhesive so that the coating film surface was on the outside, and a polarizing plate having an optical compensation layer was produced. did.

(Example 8)
A liquid crystal display device equipped with an IPS liquid crystal cell was prepared, and a display device in which the laminated optical compensation film prepared in Example 5 was superimposed on the outgoing light side of the liquid crystal cell was manufactured. As a result of observing the display screen, a good image was obtained without changing the color display when viewed from the front or from an oblique direction.

Example 9
Prepare a liquid crystal display device equipped with an IPS liquid crystal cell, remove the polarizing plate on the outgoing light side, and replace the polarizing plate produced in Example 7 with the coating film surface facing the outgoing light side of the liquid crystal cell. A display device bonded to a liquid crystal cell was manufactured. As a result of observing the display screen, a good image was obtained without changing the color display when viewed from the front or from an oblique direction.

(Comparative Example 2)
The same operation as in Example 8 was performed except that the laminated optical compensation film produced in Example 5 was not used. As a result, when viewed from an oblique direction, the color display was different from that viewed from the front due to the birefringence of the liquid crystal display device constituent members.

(Comparative Example 3)
The same operation as in Example 9 was performed except that the polarizing plate produced in Example 7 was not used and the polarizing plate on the outgoing light side was used as it was. As a result, when viewed from an oblique direction, the color display was different from that viewed from the front due to the birefringence of the liquid crystal display device constituent members.

Claims (17)

A coating solution for forming an optical compensation coating film formed by containing the following (A) and (B).
(A) Cellulose N-Substituted Carbamate (B) A monocarboxylic acid ester solvent in which component (A) is soluble, wherein the ester group has an alkyl chain having 1 to 16 carbon atoms. In the cellulose N-substituted carbamate, at least one hydroxyl group of cellulose is N-substituted carbamate, and at least one hydrogen atom bonded to a nitrogen atom of the carbamate group is represented by the following general formulas (1) to (3). (The substituent bonded to N), and the substituents bonded to N of the plurality of N-substituted carbamate groups are the same or different and are represented by the following general formulas (1) to (3). The coating solution for forming an optical compensation coating film according to claim 1, wherein the coating solution is an optical compensation coating film.

(Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ are the same or different and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or 1 to 20 carbon atoms. Halogenated alkyl groups, C6-C20 aryl groups, C6-C20 aryloxy groups, C7-C20 aralkyl groups, C7-C20 aralkyloxy groups, C1-C21 Represents an acyloxy group, a halogen atom, or a nitro group.)

(Wherein R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² are the same or different and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms. Represents a halogenated alkyl group having 1 to 20 carbon atoms, an acyloxy group having 1 to 21 carbon atoms, a halogen atom, or a nitro group.)

(In the formula, R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ are the same or different and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms. Represents a halogenated alkyl group having 1 to 20 carbon atoms, an acyloxy group having 1 to 21 carbon atoms, a halogen atom, or a nitro group.)   The monocarboxylic acid ester solvent is methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, tert-butyl acetate, n-pentyl acetate, n-hexyl acetate. The coating solution for forming an optical compensation coating film according to claim 1, wherein the coating solution is at least one selected from the group consisting of n-octyl acetate, and heptyl acetate.   The monocarboxylic acid ester solvent is at least one selected from n-butyl acetate, n-pentyl acetate, and n-hexyl acetate, according to any one of claims 1 to 3. Coating liquid for forming optical compensation coating film.   The coating solution for forming an optical compensation coating film according to any one of claims 1 to 3, further comprising (C) an ether solvent.   An optical compensation coating film obtained by coating and drying the coating solution according to claim 1. Of the in-plane refractive indexes, the largest one is _nx , the smallest one is _ny , the refractive index in the thickness direction is _nz , and the film thickness is d. The coating film for optical compensation according to claim 6.
[(N _x + n _y ) / 2−n _z ] × d <0 (Formula 1)   6. A method for forming a coating film for optical compensation, comprising: coating a coating liquid according to claim 1 on a substrate to form a coated substrate; and drying the coated substrate.   9. The coated substrate is first dried at a temperature in a range of a lower limit of 0 ° C. and an upper limit of 40 ° C., and then the coated substrate is further subjected to secondary drying at a lower limit of 80 ° C. and an upper limit of 300 ° C. A method for forming the coating film for optical compensation as described.   The method for forming a coating film for optical compensation according to claim 9, wherein the primary drying time is 3 minutes or more.   An optical element formed by using the method for forming an optical compensation coating film according to claim 8.   The optical element according to claim 11, wherein the haze is 5% or less.   A laminated optical compensation comprising the optical compensation coating film according to any one of claims 6 and 7 formed on at least one surface of a film having controlled birefringence. the film.   14. The laminated optical compensation film according to claim 13, wherein the film having controlled birefringence is a film made of a material having positive birefringence.   A laminated optical compensation film manufactured by the method for forming a coating film for optical compensation according to any one of claims 8 to 10, wherein a film having controlled birefringence is used as a substrate. .   A polarizing plate comprising the laminated optical compensation film according to claim 13 as a polarizer protective film mounted on at least one surface of a polarizer.   The optical compensation coating film according to claim 6, 7, the optical element according to claim 11, 12, the laminated optical compensation film according to claim 13, 14, or 15, or the polarizing plate according to claim 16. A liquid crystal display device comprising one or more components selected from the group consisting of: