JP2007148312A - Coating film for optical compensation, and optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide a coating film for optical compensation without requiring a complicated film forming step, to provide a method for forming a coating film for optical compensation that shows a negative value of (n<SB>x</SB>+n<SB>y</SB>)/2-n<SB>z</SB>and its larger absolute value, wherein n<SB>x</SB>represents the maximum refractive index and n<SB>y</SB>represents the minimum refractive index in the film plane, n<SB>z</SB>represents a refractive index in the thickness direction, and d represents the film thickness, so as to obtain to an optical element having the same characteristics without requiring a troublesome work such as sticking a film and an optical element in a thin film state containing cellulose N-substituted carbamate, and to provide an optical element manufactured by the above method. <P>SOLUTION: The coating film for optical compensation contains cellulose N-substituted carbamate. The method for forming a coating film for optical compensation includes applying a coating liquid containing cellulose N-substituted carbamate and a solvent that can dissolve the compound on a substrate to obtain a coated substrate and drying the substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical compensation coating film for optically compensating for a phase difference by a liquid crystal cell or the like, an optical compensation coating film-forming coating solution suitable for forming the coating film, and the optical compensation coating film. The present invention relates to a film forming method. Furthermore, it is related with the optical element manufactured using them, and the manufacturing method of an optical element. Furthermore, the present invention relates to an optical compensation film (retardation film), a polarizing plate provided with the optical compensation film, and a liquid crystal display device.

  In a liquid crystal display device, a phase difference film for optical compensation is used in order to compensate for a phase difference due to birefringence of a liquid crystal cell, a polarizing plate, other liquid crystal display device constituent films, etc., and to expand a viewing angle. As such a retardation film, for example, a polymer such as polycarbonate, polyester, polystyrene, polyamide, polyimide, polyethersulfone, solution casting method, uniaxial stretching method after solution casting, and drying product after solution casting. Examples thereof include a biaxial stretching method, an extrusion method, a uniaxial stretching method of an extruded product, a biaxial stretching method of the extruded product, a calendar method, and the like (for example, see Patent Document 1 and Patent Document 2). Such a retardation film is a film made of a material having a positive intrinsic birefringence value such as polycarbonate, or a film such as polystyrene, in accordance with the applied liquid crystal cell, polarizing plate, or other liquid crystal display device constituting film. One to several films made of a material having a negative intrinsic birefringence value are used separately. In order to use these films, first, a complicated film forming process is required for film formation, and it is also necessary to attach these films to liquid crystal display device components.

To solve these problems, formation of the retardation layer has been proposed by the thin film formation by paste coating of polyimide having the optical properties of _{n z <n x = n y} ( e.g., see Patent Document 3.). _Meanwhile, those having an optical characteristics of the _{n z> n x ≧ n y} , in other words, _{[(n x + n y) /} 2-n z ] that the value of the thickness retardation expressed as × d is negative for _the application of the compounds with optical properties of _{n z>} n x = n _y is proposed. This is a method of applying a solution of a polymer compound having a functional group capable of photoisomerization, drying and then applying light to control the orientation of the polymer, or applying a liquid crystal polymer solution or a liquid crystal polymer melt, After drying, the liquid crystal is aligned by heat treatment at the glass transition temperature of the polymer, and the alignment is fixed by cooling (for example, see Patent Document 4). However, compared to the formation of a retardation layer by applying polyimide paste, when using a polymer compound having a functional group that can be photoisomerized, there is a complication that light irradiation has to be performed. However, there is a drawback that it is expensive and expensive.

By the way, in order to compensate a large thickness direction retardation due to birefringence of a liquid crystal cell, a polarizing plate, and other liquid crystal display device constituting films, the sign of the retardation in the thickness direction is opposite, and [(n _x + n It is effective to use an optical compensation material having a large absolute value of the thickness retardation represented by _y ) / 2−n _z ] × d. For that purpose, it is particularly effective to form a material having a large absolute value represented by (n _x + _ny ) / 2− _nz by a large forming method. This is because, when the absolute value of the value represented by (n _x + _ny ) / 2− _nz is not sufficient and the film thickness needs to be increased, the liquid crystal display device components after forming the coating film are bulky. This is because problems such as an increase in the material cost of the coating film arise.
JP-A-3-33719 JP 11-248939 A JP 2001-290023 A JP-A-7-13022

An object of the present invention is to provide a coating film for optical compensation at a low cost without requiring a complicated film forming step. Furthermore, an optical compensation coating film having the characteristics of [(n _x + _ny ) / 2−n _z ] × d <0 is provided at low cost, and the characteristics can be achieved without the need for film sticking or the like. An optical element is provided.

Furthermore, the present invention provides a method for forming an optical compensation coating film that contains cellulose N-substituted carbamate, has a negative value represented by (n _x + _ny ) / 2- _nz , and has a larger absolute value. It is to provide an optical element manufactured using the forming method.

  In order to solve such problems, the present inventors have found that the above problems can be solved by an optical compensation coating film characterized by containing cellulose N-substituted carbamate. The present invention has been reached.

  That is, the present invention relates to a coating film for optical compensation, which is formed containing cellulose N-substituted carbamate.

As a preferred embodiment, it is formed by containing a cellulose N- substituted carbamates, 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, film The present invention relates to a coating film for optical compensation characterized by satisfying a relationship of [(n _x + _ny ) / 2− _nz ] × d <0, where d is a thickness.

  In a preferred embodiment, 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 cellulose carbamate is represented by the following general formula ( It is a compound that is substituted with a group selected from 1) to (3), and the plurality of N-substituents are the same or different and are groups selected from the following general formulas (1) to (3). It is related with the coating film for optical compensation characterized by these.

（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。）
さらに本発明は、下記（Ａ）、（Ｂ）を含有して形成される光学補償用塗工膜形成用塗工液に関する。

(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.)
Furthermore, the present invention relates to a coating solution for forming an optical compensation coating film formed by containing the following (A) and (B).

(A) The cellulose N-substituted carbamate according to any one of claims 1 to 3 (B) A solvent in which component (A) is soluble and soluble.

  Furthermore, the present invention relates to a method for forming an optical compensation coating film, wherein the coating liquid is applied to a substrate to form a coated substrate, and then the coated substrate is dried.

  As a preferred embodiment, after the coated substrate is primarily dried at a temperature in the range of 0 ° C. lower limit and 40 ° C. upper limit, the coated substrate is further subjected to secondary drying at a lower limit of 80 ° C. and an upper limit of 300 ° C. The present invention relates to a method for forming a characteristic optical compensation coating film.

  Furthermore, the present invention provides an optical compensation coating characterized in that after a coating liquid is applied to a substrate to form a coated substrate, the coating film is annealed by exposure to the vapor of component (B) and further dried. The present invention relates to a film forming method.

  Furthermore, the present invention relates to a method for manufacturing an optical element using the above-described forming method.

  Furthermore, this invention relates to the optical element manufactured using said manufacturing method.

  Furthermore, the present invention relates to an optical compensation film manufactured using the above-described forming method.

  Furthermore, the present invention relates to a polarizing plate characterized in that an optical compensation film is mounted on at least one surface of a polarizer as a polarizer protective film.

  Furthermore, the present invention relates to a liquid crystal display device provided with an optical compensation film.

  The present invention further relates to a liquid crystal display device including a polarizing plate equipped with an optical compensation film.

When the coating film for optical compensation of the present invention is used, an optical element can be produced without the need for troublesome film forming steps and film sticking, and in particular, [(n _x + _ny ) / 2− _nz ]. An optical element having an optical compensation layer of xd <0 can be manufactured. Further, when the method for forming a coating film for optical compensation of the present invention is used, a cellulose N-substituted carbamate having a larger value represented by (n _x + _ny ) / 2− _nz having a negative negative value. Since an optical compensation coating film containing can be formed, and a thinner optical element can be manufactured, it is extremely useful industrially.

  Hereinafter, the present invention will be described in detail. The present invention is a coating film for optical compensation, which is formed by containing cellulose N-substituted carbamate.

  In the cellulose N-substituted carbamate of the present invention, at least one hydroxyl group of cellulose is N-substituted carbamate, and at least one hydrogen atom bonded to a nitrogen atom of cellulose carbamate is represented by the following general formula (1) to The compound is substituted with a group selected from (3), and the plurality of N-substituents are the same or different and are compounds selected from the following general formulas (1) to (3). An optical compensation coating film.

（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。）
本発明における、セルロース Ｎ−置換カーバメートは（以下（Ａ）成分と言うことがある）、例えば、各種木材パルプ、綿リンター、綿リント等から得られるセルロースを原料とし、ピリジン、トリエチルアミン等の塩基触媒存在下でイソシアネート系化合物を反応させる既知の方法により製造することができる。尚、前記塩基触媒は溶媒としても使用することができる。その他の溶媒としては、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ，Ｎ−ジメチルアセトアミド等のアミド系溶媒を好適に用いることができる。更に、セルロースの溶媒に対する溶解性を向上させるために塩化リチウム等の無機塩を添加することもできる。また、このようなイソシアネート系化合物の例としては、下記一般式（４）〜（６）で表される化合物が挙げられる。

(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 cellulose N-substituted carbamate in the present invention (hereinafter sometimes referred to as the component (A)), for example, cellulose obtained from various wood pulps, cotton linters, cotton lints, and the like, and base catalysts such as pyridine and triethylamine It can be produced by a known method in which an isocyanate compound is reacted in the presence. The base catalyst can also be used as a solvent. As other solvents, 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 such isocyanate compounds 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 0.1, more preferably 0.5, still more preferably 1, and the upper limit is preferably 3, more preferably 2.95, and even more preferably 2.9. . When DS is lower than 0.1, 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, a coating solution for forming an optical compensation coating film (hereinafter sometimes simply referred to as a coating solution) will be described. The coating liquid contains (A) the cellulose N-substituted carbamate and (B) a solvent in which the component (A) is soluble and soluble.

  The solvent for the component (B) is not particularly limited as long as the component (A) is soluble. Specific examples include benzene, toluene, o-xylene, m-xylene, and p-xylene. Hydrocarbon solvents such as isomer mixtures of ethylbenzene, isopropylbenzene and diethylbenzene; methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, furfuryl alcohol, Alcohol solvents such as benzyl alcohol; ether solvents such as ethyl ether, isopropyl ether, 1,3-dioxolane, 1,4-dioxane, tetrahydropyran, tetrahydrofuran, 1,2-dimethoxyethane; acetone, 2-butanone, 4 -Methyl-2-pentanone, cyclohexanone Ketone solvents: 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-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, Halogen solvents such as 1,3,5-trichlorobenzene; methyl acetate, ethyl acetate, acetic acid Ester solvents such as propyl, isopropyl acetate, butyl acetate, ethylene glycol monomethyl ether acetate, ethyl cellosolve 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. These solvents may 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 components (A) and (B) is 1% by weight lower limit and 70% by weight upper limit, More preferably, 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.

  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 for the optical element 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 produced by polycondensation from bisphenol A and carbonyl chloride; polyacrylates such as polymethyl acrylate and polymethyl methacrylate; adipic acid Polyester polymers obtained by condensation of dibasic acids such as phthalic acid, isophthalic acid and terephthalic acid with glycols such as ethylene glycol, diethylene glycol, propylene glycol, tetramethylene glycol and neopentyl glycol, or ring-opening polymerization of lactones Styrene polymers such as polystyrene and poly (α-methylstyrene); copolymers of acrylate and styrene; polyolefins such as polyethylene, polynorbornene, polyisoprene hydrogenated, polybutadiene hydrogenated Coalescence Cellulosic resins such as triacetyl cellulose; polyamides such as nylon 6 and nylon 66; polyimides; polyamideimides; polyvinyl alcohol; vinyl chloride; polyethersulfone; And the like. As a substrate, these polymers can be used as a solution casting method, a uniaxial stretching method of a dried product after solution casting, a biaxial stretching method of a dried product after solution casting, an extrusion method, a uniaxial stretching method of an extruded product, Examples thereof include a film formed by an axial stretching method, a calendar method, etc., a polarizing plate, a glass plate, a color filter, a liquid crystal cell, etc., which are attached to a polarizer using these films as protective films. These substrates can also be used as substrates when forming an optical compensation coating film.

  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 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.

In primary drying, a temperature range with a lower limit of 0 ° C. and an upper limit of 40 ° C. is preferred, a lower limit of 5 ° C. and an upper limit of 35 ° C. are more preferred, and a lower limit of 10 ° C. and an upper limit of 30 ° C. are more preferred. Primary drying is necessary for the basic formation of the inner structure of the coating film necessary to increase 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. Secondary drying is necessary to establish the coating film internal structure necessary to increase the absolute value of the value represented by (n _x + _ny ) / 2− _nz . 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. In addition, when the absolute value of the value represented by (n _x + _ny ) / 2− _nz is sufficiently large, the established internal structure of the coating film is observed from the cross section of the coating film with a transmission electron microscope (TEM) or the like. Can be observed.

  Furthermore, the present invention provides a coating film for optical compensation by coating a coating solution on a substrate to form a coated substrate, then exposing the coating film to the vapor of component (B), and further drying the coating film. It can also be a method.

  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 in the vapor of the component (B) with the coating film of the coating substrate facing up and left still horizontally. The temperature at the time of annealing can be variously set, but the lower limit is preferably −30 ° C. and the upper limit [(B) component boiling point (° C.)], and the lower limit is −15 ° C. and the upper limit [(B) component boiling point (° C.) −5 ° C.] is more preferable, and the lower limit is 0 ° C., and the upper limit [(B) component boiling point (° C.) − 10 ° C.] is more preferable. If the annealing temperature is lower than −30 ° C., the annealing time tends to be longer, and if the annealing temperature is higher than the boiling point (° C.) of the component (B), the coating film tends to flow out from the substrate. There is. 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.

  Next, the manufacturing method of the optical element of this invention is demonstrated. The optical element here is composed of a substrate and an optical compensation coating film coated on the substrate. In addition, the optical compensation coating film is once peeled off from the substrate and then used for optical use.

  The optical element is coated on the one surface or both surfaces of the substrate using the coating method described in the method for forming the optical compensation coating film, followed by drying or the optical compensation coating. It can manufacture suitably by annealing and drying after application | coating using the coating method demonstrated by the formation method of a film | membrane.

  Drying can be suitably performed by using the drying method and drying temperature described in the method for forming the optical compensation coating film.

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, the thickness is taken as d, It is preferable to have a characteristic of [(n _x + n _y ) / 2−n _z ] × d <0. In particular, in an unstretched film formed by a solution casting method using a solution in which the cellulose N-substituted carbamate is dissolved in the solvent exemplified as the component (B), [(n _x + _ny ) / 2− _nz ] × It is preferable that the above characteristics be obtained by an optical compensation coating film formed by containing cellulose N-substituted carbamate satisfying the relationship of d <0. 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 in the measurement 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 measured at 590 nm using a lower limit of −1000 nm and an upper limit of −1 nm, more preferably a lower limit of −800 nm and an upper limit of −10 nm, and even more preferably a lower limit of −600 nm and an upper limit of −20 nm. 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 optical compensation film (retardation film) of the present invention will be described. The optical compensation film (retardation film) is a film formed from those exemplified as the substrate for the optical element, and the optical compensation layer is formed using the method for forming the optical compensation coating film. Can be more suitably produced.

  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. Examples of the protective film include those formed as examples of the substrate for the optical element, and the optical compensation film (retardation film) of the present invention. When the polarizing plate is bonded to both sides of the polarizer, after the polarizing plate is prepared, the optical compensation coating film of the present invention is provided on at least one side of the polarizing plate using the method for forming an optical compensation coating film. The polarizing plate of the present invention can be obtained. When the optical compensation film (retardation film) of the present invention is used as a protective film, it can be used on both sides of a polarizer, or the optical compensation film (retardation film) of the present invention is used on one side and the opposite. It is also possible to use a film made of the optical element substrate on the surface. In addition, a polarizing plate using the optical compensation film (retardation film) of the present invention on one side and a film of the substrate for the optical element on the opposite side is prepared, and then newly applied on one side or both sides. The coating film for optical compensation of the present invention can also be provided.

  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. The optical compensation film (retardation film) of the present invention is mounted on the side and / or the outgoing light side, and / or the polarizing plate of the present invention is mounted on the polarizing plate on the incident light side and / or the outgoing light side of the liquid crystal cell. Thus, the liquid crystal display device of the present invention 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.

  In addition, the optical compensation coating film of the present invention, the optical compensation coating film-forming coating liquid, the optical element produced using them, and the optical compensation film (retardation film) are VA, IPS, It can be used for viewing angle expansion of a liquid crystal display device using an OCB type liquid crystal cell. 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 optical compensation film (retardation film) are used in video, camera, mobile phone, personal computer, television, It can be suitably used for liquid crystal display device production parts such as monitors and automobile instrument panels.

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

The three-dimensional refractive indexes by using the _{(n x, n y, n} z) calculated Oji Scientific Instruments Ltd. automatic birefringence meter KOBRA-WR, and subjected to measurement by 590nm light under 25 ° C., were calculated three-dimensional refractive index. From the results obtained, was determined plane retardation by _{(n x -n y) × d} . Moreover, the thickness retardation was calculated | required by [( _nx + _ny ) / 2- _nz ] * d. 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, was determined plane retardation by _{(n x -n y) × d} . Moreover, the thickness retardation was calculated | required by [( _nx + _ny ) / 2- _nz ] * d.

(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) 1.0 g was added, and 100 ml of pyridine was added to form a suspension, and then 7.7 g of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added. Nitrogen was introduced, and the temperature was raised to 110 ° C. with stirring, followed by reaction for 7 hours. Thereafter, after cooling to 25 ° C., the reaction solution was dropped into 400 ml of ethanol to form a precipitate. After separation by filtration, 25 ml of acetone was added to the obtained polymer to dissolve it, and then dropped into 400 ml of pure water to cause precipitation. After separation by filtration, the obtained polymer was again dissolved in 30 ml of acetone and dropped into 400 ml of pure water to form a precipitate. After separation by filtration, washing with water and vacuum drying at 60 ° C. for 4 hours, 2.5 g of cellulose N-phenyl carbamate (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.

Synthesis Example 2 Synthesis of Cellulose N-Phenyl Carbamate (2) 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) 1.0 g was added, and 100 ml of pyridine was added to form a suspension, and then 7.7 g of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added. Nitrogen was introduced, and the temperature was raised to 110 ° C. with stirring, followed by reaction for 7 hours. Thereafter, after cooling to 25 ° C., the reaction solution was dropped into 400 ml of ethanol to form a precipitate. After separation by filtration, the obtained polymer was dissolved by adding 30 ml of acetone, and then dropped into 400 ml of pure water to cause precipitation. After separation by filtration, it was washed with water and vacuum dried at 60 ° C. for 4 hours to obtain 2.2 g of cellulose N-phenyl carbamate (2) (hereinafter sometimes referred to as synthetic product (2)). The substitution degree DS of the synthesized product (2) 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.

(Synthesis Example 3) Synthesis of cellulose N- [2- (trifluoromethyl) phenyl] carbamate (3) In a 500 ml four-necked flask equipped with a cooling tube, a nitrogen introducing tube, a stirrer, and a thermometer, 7 at 60 ° C. 7. 1.0 g of cellulose (Avicel TG-F20, manufactured by Asahi Kasei Chemicals), which was vacuum-dried for a period of time, was added to form a suspension by adding 100 ml of pyridine, and further 2- (trifluoromethyl) phenyl isocyanate (manufactured by Tokyo Chemical Industry). 7 g was added. Nitrogen was introduced, and the temperature was raised to 110 ° C. with stirring, followed by reaction for 7 hours. Thereafter, after cooling to 25 ° C., 200 ml of ethanol was added, and the reaction solution was dropped into 1.5 L of pure water to produce a precipitate. After separation by filtration, the obtained polymer was dissolved by adding 100 ml of acetone, and then dropped into 2 L of pure water to cause precipitation. After separation by filtration, washing with water and vacuum drying at 60 ° C. for 4 hours, the polymer was put into a Soxhlet extractor. After Soxhlet extraction with methanol 20 times, vacuum drying was performed at 25 ° C. for 4 hours to obtain 3.4 g of cellulose N- [2- (trifluoromethyl) phenyl] carbamate (3) (hereinafter, synthesis) Sometimes called product (3).) DS of the synthesized product (3) was 3 as a result of proton NMR analysis. In addition, DS compares the chemical shift (3.5 to 5.5 ppm) area of proton derived from cellulose skeleton and the chemical shift (6.9 to 7.9 ppm) area of proton of 2- (trifluoromethyl) phenyl group. Decided by.

Example 1
To 0.85 g of the synthetic product (1), 4.15 g of butyl acetate was added and dissolved at 25 ° C. Next, this coating solution was applied to a 150 μm thick glass substrate (average refractive index: 1.52, in-plane retardation: 0 nm, thickness retardation: 1 nm) using a bar coater, and then 1 ° C. at 120 ° C. The optical element was produced by drying in air for a minute. 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, and the results are shown in Table 1.

(Example 2)
To 0.85 g of the synthetic product (1), 4.15 g of ethyl cellosolve acetate was added and dissolved at 25 ° C. Next, this coating solution was applied to a 150 μm-thick glass substrate (average refractive index: 1.52, in-plane retardation: 0 nm, thickness retardation: 1 nm) using a bar coater, and then ethyl cellosolve acetate It put into the glass container with which vapor | steam was filled, and after sealing, it annealed at 25 degreeC for 24 hours. Thereafter, the coated substrate was taken out and dried in air at 120 ° 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, and the results are shown in Table 1.

(Example 3)
To 1.0 g of the synthetic product (3), 9.0 g of chloroform was added and dissolved at 25 ° C. Next, this coating solution was applied to 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, and then 1 at 100 ° C. The optical element was produced by drying in air for a minute. 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, and the results are shown in Table 1.

Example 4
The optical element produced in Example 3 was put in a glass container filled with chloroform vapor, sealed, and then annealed at 30 ° C. for 7.5 hours. Thereafter, the optical element was taken out and dried in air at 100 ° C. for 1 minute. 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, and the results are shown in Table 1. Here, small ones were obtained birefringence in the plane than the Example 3 (n x _{-n y).} That is, the in-plane retardation can be reduced by annealing.

(Example 5)
To 0.52 g of the synthetic product (2), 3.48 g of 1,2-dimethoxyethane was added and dissolved at 23 ° 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, this coated substrate was dried in air at 23 ° C. for 44 hours 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 2.

(Example 6)
To 0.5 g of the synthetic product (2), 4.5 g of ethylene glycol monomethyl ether acetate was added and dissolved at 23 ° 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, this coated substrate was 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 2.

(Example 7)
To 0.5 g of the synthetic product (2), 4.0 g of butyl acetate and 0.5 g of ethylene glycol monomethyl ether acetate were added and dissolved at 23 ° 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, this coated substrate was dried in air at 23 ° C. for 25 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 2.

(Example 8)
The same operation as in Example 7 was performed except that the coated substrate was dried in air at 30 ° C. for 25 minutes to produce an optical element. The physical properties of the obtained optical element were measured. The results are shown in Table 2.

Example 9
The same operation as in Example 5 was performed except that the coated substrate was dried in air at 23 ° C. for 44 hours and further dried in air at 100 ° C. for 1 minute to produce an optical element. The physical properties of the obtained optical element were measured. The results are shown in Table 2. An optical element having a larger absolute value represented by (n _x + _ny ) / 2− _nz is obtained than in Example 5 which is simply dried in air at 23 ° C. for 44 hours.

(Example 10)
The same operation as in Example 6 was performed except that the coated substrate was dried in air at 23 ° C. for 19 hours and further dried in air at 100 ° C. for 1 minute to produce an optical element. The physical properties of the obtained optical element were measured. The results are shown in Table 2. An optical element having a larger absolute value represented by (n _x + _ny ) / 2− _nz is obtained than in Example 6 which is only dried in air at 100 ° C. for 1 minute.

(Example 11)
The same operation as in Example 7 was performed except that the coated substrate was dried in air at 23 ° C. for 25 minutes and further dried in air at 250 ° C. for 1 minute to produce an optical element. The physical properties of the obtained optical element were measured. The results are shown in Table 2. An optical element having a larger absolute value represented by (n _x + _ny ) / 2− _nz is obtained than in Example 7 which is simply dried in air at 23 ° C. for 25 minutes.

(Example 12)
The same operation as in Example 8 was performed except that the coated substrate was dried in air at 30 ° C. for 25 minutes and further dried in air at 250 ° C. for 1 minute to produce an optical element. The physical properties of the obtained optical element were measured. The results are shown in Table 2. An optical element having a larger absolute value represented by (n _x + _ny ) / 2− _nz is obtained than in Example 8 which was only dried in air at 30 ° C. for 25 minutes.

（実施例１３）
ガラス基板の代わりに４０μｍ厚のセルロースアセテートフィルム（面内位相差：０ｎｍ，厚み位相差：８ｎｍ）を用い、その上に１００００ｎｍの塗工膜を形成して光学補償フィルムを作製したこと以外は実施例１０と同様の操作を行った。得られた光学補償フィルムの物性測定を行った結果、面内位相差は０ｎｍ、厚み位相差は−４０ｎｍであった。

(Example 13)
Implemented except that a 40 μm thick cellulose acetate film (in-plane retardation: 0 nm, thickness retardation: 8 nm) was used instead of the glass substrate, and a 10,000 nm coating film was formed thereon to produce an optical compensation film. The same operation as in Example 10 was performed. As a result of measuring the physical properties of the obtained optical compensation film, the in-plane retardation was 0 nm and the thickness retardation was −40 nm.

(Example 14)
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. Furthermore, the optical compensation film produced in Example 13 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. .

(Example 15)
A liquid crystal display device equipped with an IPS liquid crystal cell was prepared, and a display device in which the optical compensation film produced in Example 13 was superimposed on the outgoing light side of the liquid crystal cell was produced. 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 16)
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 14 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 1)
The same operation as in Example 15 was performed except that the optical compensation film produced in Example 13 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 2)
The same operation as in Example 16 was performed except that the polarizing plate produced in Example 14 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 (13)

  A coating film for optical compensation, comprising a cellulose N-substituted carbamate. Is formed by containing a cellulose N- substituted carbamates, 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, the thickness when the d The coating film for optical compensation according to claim 1, wherein a relationship of [(n _x + _ny ) / 2−n _z ] × d <0 is satisfied. In the cellulose N-substituted carbamate, at least one of hydroxyl groups of cellulose is N-substituted carbamate, and at least one hydrogen atom bonded to a nitrogen atom of the cellulose carbamate is represented by the following general formulas (1) to (3). And a plurality of N-substituents are the same or different and are compounds selected from the following general formulas (1) to (3): The coating film for optical compensation according to any one of claims 1 and 2.

(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.) A coating solution for forming an optical compensation coating film formed by containing the following (A) and (B).
(A) Cellulose N-substituted carbamate according to claims 1 to 3 (B) A solvent in which component (A) is soluble and soluble   A method for forming an optical compensation coating film, comprising: applying a coating solution according to claim 4 onto a substrate to form a coated substrate; and drying the coated substrate.   6. The coated substrate is first dried at a temperature in a range of 0 ° C. lower limit and 40 ° C. lower limit, and then further dried at 80 ° C. lower limit and 300 ° C. upper limit. A method for forming the coating film for optical compensation as described.   An optical compensation coating comprising: applying the coating liquid according to claim 4 onto a substrate to form a coated substrate; exposing the coating film to vapor of component (B); and further drying the coating film. Method for forming a film.   An optical element manufacturing method using the forming method according to claim 5.   An optical element manufactured using the manufacturing method according to claim 8.   An optical compensation film produced by using the forming method according to claim 5.   A polarizing plate comprising the optical compensation film according to claim 10 mounted on at least one surface of a polarizer as a polarizer protective film.   A liquid crystal display device comprising the optical compensation film according to claim 10.   A liquid crystal display device comprising the polarizing plate according to claim 11.