JP2011122170A - Cellulose ester film containing ultraviolet absorbent polymer and ultraviolet absorbent polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cellulose ester film which has few troubles in coating application and is excellent in productivity and highly transparent. <P>SOLUTION: The cellulose ester film is characterized by comprising an ultraviolet absorbent polymer having repeating units represented by general formula (1), wherein J<SB>1</SB>represents -O-, -NR<SB>1</SB>-, -S-, -SO-, -SO<SB>2</SB>-, -POO-, -CO-, -COO-, -NR<SB>2</SB>CO-, -NR<SB>3</SB>COO-, -NR<SB>4</SB>CONR<SB>5</SB>-, -OCO-, -OCONR<SB>6</SB>-, -CONR<SB>7</SB>-, -NR<SB>8</SB>SO-, -NR<SB>9</SB>SO<SB>2</SB>-, etc.; R<SB>1</SB>to R<SB>11</SB>is H, alkyl, aryl group; Sp<SB>1</SB>is a divalent linking group. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cellulose ester film, an optical film used for optical applications, a polarizing plate, an optical compensation film, and a liquid crystal display device, and in particular, a protective film for a polarizing plate used for a liquid crystal display device, a retardation film, The present invention relates to an optical film that can be used for various functional films such as a viewing angle widening film, an antireflection film used in a plasma display, and various functional films used in an organic EL display.

  In recent years, the development of high definition, thin and light notebook computers has been progressing. Along with this, there is an increasing demand for higher performance and thinner film for protective films for polarizing plates for liquid crystals. In general, cellulose ester films are widely used as polarizing plate protective films for reasons such as transparency and refractive index. However, when the cellulose ester film is simply made into a thin film, various problems occur.

  That is, an ultraviolet absorber is used for the purpose of protecting a polarizer and a liquid crystal from ultraviolet rays in the cellulose ester film conventionally used for a protective film for a polarizing plate. If this cellulose ester film is simply thinned, the ultraviolet rays cannot be sufficiently cut, and the amount of the ultraviolet absorber must be increased by the amount of the thinned film.

  JP-A-6-130226 and JP-A-7-11056 have been proposed for ultraviolet absorbers.

  However, simply increasing the amount of the UV absorber proposed in these cases causes the UV absorber to adhere to the peeling roll and the transport roll in the cellulose ester film forming process, causing a failure and greatly reducing the productivity. It turns out that it causes a new problem.

  Patent Document 1 proposes a protective film for a polarizing plate containing an ultraviolet absorbing polymer.

  However, the UV-absorbing polymer proposed here has insufficient compatibility with the cellulose ester, so that the haze increases when the amount is increased, so that it can be used for high-definition liquid crystal display devices in recent years. It turned out to be insufficient.

  On the other hand, the optical compensation film is an optically anisotropic film that can be used for a liquid crystal display device that has attracted attention in recent years in place of the CRT.

  Since the liquid crystal display device uses a liquid crystal material having anisotropy, there is a problem of viewing angle that the display performance deteriorates when viewed from an oblique direction, and further improvement in performance has been desired.

  As an optical compensation film, an anisotropic material obtained by fixing the alignment form of a liquid crystalline compound has been the mainstream recently, but the production method thereof has conventionally been based on a cellulose ester film as a support, on which a liquid crystalline compound is formed. Since the UV light absorber in the cellulose ester film is mixed into the liquid crystal compound due to the bleed phenomenon, the orientation of the liquid crystal compound is disturbed or white turbidity occurs. Had.

JP-A-6-148430

  Accordingly, an object of the present invention is to provide a cellulose ester film with few coating failures, excellent productivity and excellent transparency, an optical film, a polarizing plate, an optical compensation film and a liquid crystal display device made using the same. There is to do.

  The above object of the present invention is achieved by the following configurations.

  (1) A cellulose ester film comprising an ultraviolet absorbing polymer containing a repeating unit represented by the following general formula (1).

(Wherein J ₁ represents —O—, —NR ₁ —, —S—, —SO—, —SO ₂ —, —POO—, —CO—, —COO—, —NR ₂ CO—, —NR) _{3 COO -, - NR 4 CONR} 5 -, - OCO -, - OCONR 6 -, - CONR 7 -, - NR 8 SO -, - NR 9 SO 2 -, - SONR 10 -, - SO 2 NR 11 - the _represents, R 1 _{to R 11} represents a hydrogen atom, an alkyl group, .Sp ₁ representing the aryl group represents a divalent linking group, a halogen atom, which may have a substituent. However, ultraviolet absorbent to Sp ₁ The group is bonded directly or through a spacer, or a part or all of the ultraviolet absorbing group forms part of the polymer main chain.)
(2) A cellulose ester film comprising an ultraviolet absorbing polymer containing a repeating unit represented by the following general formula (2).

(In the formula, J ₂ and J ₃ are synonymous with J ₁ in the general formula (1), and J ₂ and J ₃ may be the same as or different from each other. Sp ₂ and Sp ₃ are the general formulas. (1) It is synonymous with Sp ₁ and Sp ₂ and Sp ₃ may be the same or different from each other, but at least one of Sp ₂ and Sp ₃ has an ultraviolet absorbing group directly or a spacer. Or in at least one of Sp ₂ and Sp ₃ , part or all of the ultraviolet absorbing group forms part of the polymer main chain.)
(3) An ultraviolet absorbing polymer containing the repeating unit represented by the general formula (1) described in (1).

  (4) An ultraviolet absorbing polymer containing the repeating unit represented by the general formula (2) described in (2).

  That is, the present inventors have made various studies on the solution of the above-mentioned problems due to the fact that only low molecular weight UV absorbers can be used in the past, and as a result, the UV absorbing weight excellent in compatibility with cellulose esters. By selecting the combination, the inventors have developed an ultraviolet absorbing polymer that exerts a remarkable effect on the performance degradation and process contamination due to the bleed-out, as well as the disordered orientation of the optical compensation film, the optical performance degradation, and the cost.

  The polymer was found to have a remarkable effect not only on bleed-out but also on the heat and humidity resistance at high temperatures and high humidity, leading to the present invention.

  Configurations other than those described above according to the present invention are listed below.

  (A) A cellulose ester film comprising an ultraviolet absorbing polymer containing a repeating unit having an ultraviolet absorbing group represented by the following general formula (3).

(Wherein R _{12 to} R ₂₅ each represents a hydrogen atom, a halogen atom, or a substituent. In R _{12 to} R ₂₅ , adjacent ones may be bonded to each other to form a ring. The UV-absorbing group represented by the general formula (3) is bonded to the polymer main chain directly or via a spacer at any site, or a part or all of the UV-absorbing group is a polymer main chain. It forms part of the chain.)
(B) A cellulose ester film comprising an ultraviolet absorbing polymer containing a repeating unit having an ultraviolet absorbing group represented by the following general formula (4).

(Wherein R ₂₆ and R ₂₇ each represent an alkyl group having 1 to 10 carbon atoms, R ₂₈ , R ₂₉ and R ₃₀ each represents an alkyl group, an alkoxy group, an alkylthio group and an amino group, and X and Y are Each represents an electron-withdrawing group, provided that R _{26 to} R ₃₀ and X and Y may have a halogen atom or a substituent, and these are connected to each other to form a 5- or 6-membered ring; However, the UV-absorbing group represented by the general formula (4) is bonded to the polymer main chain directly or via a spacer at any site, or a part of the UV-absorbing group or All form part of the polymer backbone.)
(C) A cellulose ester film comprising an ultraviolet absorbing polymer containing a repeating unit having an ultraviolet absorbing group represented by the following general formula (5).

(In the formula, R _{66 to} R ₇₁ each represent a hydrogen atom, a halogen atom, or a substituent. X and Y have the same meanings as X and Y in formula (4), provided that in formula (5) The UV-absorbing group represented is bonded to the polymer main chain directly or via a spacer at any position, or part or all of the UV-absorbing group forms part of the polymer main chain. is doing.)
(D) A cellulose ester film comprising an ultraviolet-absorbing polymer containing a repeating unit represented by the following general formula (6).

(In the formula, R ₃₁ and R ₃₂ represent a hydrogen atom, a halogen atom and a substituent, l represents 0, 1, 2, 3 and m represents 0, 1, 2, 3, 4; Or R ₃₁ may be the same or different from each other when 3, and R ₃₂ may be the same or different from each other when m is 2, 3 or 4. J ₄ is * -O-, * -NR _1- , * -S-, * -SO-, * -SO _2- , * -POO-, * -CO-, * -COO-, * -NR ₂ CO-, * -NR ₃ COO- _{, * - NR 4 CONR 5 -} , * - OCO -, * - OCONR 6 -, * - CONR 7 -, * - NR 8 SO -, * - NR 9 SO 2 -, * - SONR 10 -, * - SO ₂ represents NR ₁₁ —, where the asterisk (*) indicates that it is connected to the ultraviolet absorbing group with *, R _{1 to} R ₁₁ are represented by the general formula (1) _R 1 _{to R 11} and .Sp ₄ is as defined in has the same meaning as Sp ₁ of the general formula (1).)
(E) A cellulose ester film comprising an ultraviolet absorbing polymer containing a repeating unit represented by the following general formula (7).

(In the formula, R ₃₃ and R ₃₄ represent a hydrogen atom, a halogen atom, and a substituent, s represents 0, 1, 2, 3, 4, o represents 0, 1, 2, 3, and s represents 2) when 3 or _4, each other _{R 33} may be the same as or different from each other, when o is 2 or _3, each other _{R 34} is optionally the same as or different from each other .J ₅ is, * - o-, * -NR _1- , * -S-, * -SO-, * -SO _2- , * -POO-, * -CO-, * -COO-, * -NR ₂ CO-, * -NR ₃ COO- _{, * - NR 4 CONR 5 -} , * - OCO -, * - OCONR 6 -, * - CONR 7 -, * - NR 8 SO -, * - NR 9 SO 2 -, * - SONR 10 -, * - SO ₂ represents NR ₁₁ —, where the asterisk (*) indicates that it is connected to the ultraviolet absorbing group with *, R _{1 to} R ₁₁ are represented by the general formula (1) (It is synonymous with R _{1 to} R _{11 in the} middle. Sp ₅ is synonymous with Sp _{1 in the} general formula (1).)
(F) A cellulose ester film comprising an ultraviolet absorbing polymer which is a copolymer derived from compounds represented by the following general formulas (8) and (9).

(In the formula, R _{35 to} R ₃₉ each represent a hydrogen atom, a halogen atom, or a substituent, and Sp ₆ has the same meaning as Sp _{1 in} formula (1). Q is 0, 1, 2, 3, 4, r represents 0, 1, 2, 3. When q is 2, 3 or 4, R ₃₅ may be the same or different from each other, and when r is 2 or 3, R ₃₆ are They may be the same or different.)
(G) A cellulose ester film comprising a modified cellulose in which a UV-absorbing group is bound to either a hydroxyl group of cellulose or a cellulose derivative directly or via a spacer.

  (H) Haze is 0-0.5, The cellulose-ester film of any one of said (1), (2), (a)-(g) characterized by the above-mentioned.

  (I) The cellulose ester film according to any one of (1), (2), and (a) to (h), wherein a transmittance at 380 nm is 0 to 10%.

  (J) The above-mentioned (1), wherein the ultraviolet-absorbing polymer or the modified cellulose to which the ultraviolet-absorbing group is bonded directly or through a spacer is a copolymer with an ethylenically unsaturated monomer, 2) The cellulose ester film according to any one of (a) to (i).

  (K) The optical film is the cellulose ester film according to any one of (1), (2), and (a) to (j).

  (L) The optical film as described in (k) above, wherein the cellulose ester is a lower fatty acid ester of cellulose.

  (M) In the polarizing plate having the first optical film, the polarizer, and the second optical film, the first optical film or the second optical film is the optical film described in (k) or (l). There is a polarizing plate.

  (N) A liquid crystal display device using the polarizing plate described in (m).

  (O) An optical compensation film comprising the cellulose ester film according to any one of (1), (2) and (a) to (j) as a support.

  (P) The optical compensation film as described in (o) above, wherein the optically anisotropic layer contains a discotic compound.

  (Q) The optical compensation film as described in (o) above, wherein the optically anisotropic layer contains a biaxial liquid crystal compound.

  (R) The optical compensation film as described in (o) above, wherein the optically anisotropic layer contains a rod-like liquid crystal compound.

  The cellulose ester film according to the present invention, an optical film, a polarizing plate, an optical compensation film, and a liquid crystal display device made using the same have few coating failures, excellent productivity, and excellent transparency.

  Hereinafter, the present invention will be described in more detail.

  The ultraviolet absorbing polymer of the inventions (1) to (4) of the present invention is any ultraviolet absorbing polymer containing a repeating unit represented by the general formulas (1) and (2). Good.

In the general formula (1), J ₁ represents —O—, —NR ₁ —, —S—, —SO—, —SO ₂ —, —POO—, —CO—, —COO—, —NR ₂ CO—, —NR ₃ COO—, —NR ₄ CONR ₅ —, —OCO—, —OCONR ₆ —, —CONR ₇ —, —NR ₈ SO—, —NR ₉ SO ₂ —, —SONR ₁₀ —, —SO ₂ NR ₁₁ — Represents —O—, —S—, —COO—, —OCO—, —NR ₂ CO—, and —CONR ₇ —. R _{1 to} R ₁₁ are each a hydrogen atom, an alkyl group (for example, a methyl group, an ethyl group, an isopropyl group, a hydroxyethyl group, a methoxymethyl group, a trifluoromethyl group, a t-butyl group), an aryl group (for example, a phenyl group). Group, naphthyl group, p-tolyl group, p-chlorophenyl group and the like). The alkyl group and aryl group may be substituted or unsubstituted.

Sp ₁ represents a divalent linking group and is not particularly limited, but preferably includes a divalent linking group containing an alkylene group or an arylene group, more preferably an alkylene group having 1 to 10 carbon atoms or a carbon number. 4 to 10 arylene groups. These divalent linking groups may have a halogen atom or a substituent. Examples of the substituent include an alkyl group (for example, methyl group, ethyl group, isopropyl group, hydroxyethyl group, methoxymethyl group, trifluoromethyl group, t-butyl group), aryl group (for example, phenyl group, naphthyl group, p -Tolyl group, p-chlorophenyl group etc.), acyl group (eg acetyl group, propanoyl group, butyroyl group etc.), sulfonyl group (eg methanesulfonyl group, butanesulfonyl group, phenylsulfonyl group etc.), alkoxy group (eg methoxy group) Ethoxy group, isopropoxy group, n-butoxy group, etc.), aryloxy group (eg, phenoxy group, etc.), alkylthio group (eg, methylthio group, ethylthio group, n-butylthio group, etc.), arylthio group (eg, phenylthio group, etc.) , Amino group, alkylamino group (for example, methylamino group) , Ethylamino group, dimethylamino group etc.), arylamino group (eg phenylamino group etc.), acylamino group (eg acetylamino group, propionylamino group etc.), hydroxyl group, cyano group, carbamoyl group (eg methylcarbamoyl group, Ethylcarbamoyl group, dimethylcarbamoyl group, etc.), sulfamoyl group (eg, ethylsulfamoyl group, dimethylsulfamoyl group, etc.), sulfonamide group, acyloxy group, oxycarbonyl group, sulfonylamino group (eg, methanesulfonylamino group, benzene) Sulfonylamino groups, etc.), ureido groups (eg, 3-methylureido group, 3,3-dimethylureido group, 1,3-dimethylureido group, etc.), sulfamoylamino groups (dimethylsulfamoylamino group, etc.), alkoxy Carbo Group (eg methoxycarbonyl group, ethoxycarbonyl group etc.), aryloxycarbonyl group (eg phenoxycarbonyl group etc.), nitro group, imide group (eg phthalimide group etc.), heterocyclic group (eg pyridyl group, benzimidazolyl group etc.) , A benzthiazolyl group, a benzoxazolyl group, etc.), preferably a hydrogen atom, a halogen atom, an alkyl group, an acylamino group, a carbamoyl group, an acyloxy group, or an oxycarbonyl group.

However, an ultraviolet-absorbing group is bonded to Sp ₁ directly or via a spacer, or a part or all of the ultraviolet-absorbing group forms part of the polymer main chain.

The spacer here may be any divalent linking group, but is preferably a divalent linking group containing a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, or -O. —, —NR ₄ O—, —S—, —SO—, —SO ₂ —, —POO—, —CO—, —COO—, —NR ₄₁ CO—, —NR ₄₂ COO—, —NR ₄₃ CONR _{44 -, - OCO -, - OCONR} 45 -, - CONR 46 - include either a substituted or unsubstituted alkylene group or a substituted or a divalent linking group comprising a combination of unsubstituted arylene group, a.

_Here, R 41 _{to R 46} each represent a hydrogen atom, a hydroxyl group, an alkyl group, an aryl group. Each of the alkyl group and the aryl group may have a plurality of substituents, and examples of the substituent include those exemplified as examples of the substituent that Sp ₁ in the general formula (1) can take.

  The UV-absorbing group in the present invention is a group that has extremely large spectral absorption at 380 nm and hardly absorbs visible light of 420 nm or more, and any group having such properties may be used. Can include ultraviolet absorbing groups obtained by removing one or more hydrogen atoms from the compounds represented by the following general formulas (10) to (18).

Each of the ultraviolet absorbing groups of the present invention may be substituted with one or more halogen atoms and substituents. Examples of the substituent, those mentioned as examples of the substituent Sp ₁ in the general formula (1), and the like. Of course, the repeating units represented by the general formulas (1) and (2), the UV-absorbing groups represented by the general formulas (3) to (5), and the repeating units represented by the general formulas (6) and (7). You may have an ultraviolet absorptive group in a unit.

In the general formulas (10) to (18), R _{55 to} R ₆₅ represent a hydrogen atom, a halogen atom, or a substituent, and examples of the substituent include those of the Sp ₁ substituent in the general formula (1). In general formula (12), R ₅₅ and R ₅₆ are preferably a hydrogen atom and an alkyl group. In general formula (15), R ₅₇ , R ₅₈ and R ₅₉ are each a hydrogen atom and an alkyl group. In the group, aryl group, and general formula (17), examples of R ₆₀ and R ₆₁ include an alkyl group.

In addition, R _{62 to} R ₆₅ in the general formulas (17) and (18) are preferably an alkyl group, an aryl group, an alkoxy group, an alkylthio group, and an amino group. In the general formula (15), X represents a methylene or chalcogen atom, preferably a sulfur atom.

In the general formulas (17) and (18), EWG _{1 to} EWG ₄ represent an electron-withdrawing group, and examples of the electron-withdrawing group include an acylamino group (for example, an acetylamino group and a propionylamino group), a sulfonylamino group (Eg methanesulfonylamino group, benzenesulfonylamino group etc.), sulfamoylamino group (eg dimethylsulfamoylamino group etc.), carbamoyl group (eg methylcarbamoyl group, ethylcarbamoyl group, dimethylcarbamoyl group etc.), sulfamoyl group (Eg ethylsulfamoyl group, dimethylsulfamoyl group etc.), alkoxycarbonyl group (eg methoxycarbonyl group, ethoxycarbonyl group etc.), aryloxycarbonyl group (eg phenoxycarbonyl group etc.), sulfonyl group (eg methanesulfonyl etc.) , A butanesulfonyl group, a phenylsulfonyl group, etc.), an acyl group (for example, an acetyl group, a propanoyl group, a butyroyl group, etc.), a substituent such as a nitro group, a cyano group, and a halogen atom, preferably a cyano group, an acyl group Group, sulfonyl group, alkoxycarbonyl group and carbamoyl group.

However, EWG ₁ and EWG ₂ of the general formula (17) and EWG ₃ and EWG ₄ of the general formula (18) do not need to be both electron-withdrawing groups, and either one is an electron-withdrawing group. good. Further, in the general formula (17), R _{60 to} R ₆₄ , EWG ₁ , EWG ₂ , and in the general formula (18), EWG ₃ , EWG ₄ and R ₆₅ may be connected to each other to form a 5- or 6-membered ring. .

In the general formula (2), J ₂ and J ₃ have the same meaning as J ₁ in the general formula (1), and J ₂ and J ₃ may be the same as or different from each other. Sp ₂ and Sp ₃ are synonymous with Sp ₁ in the general formula (1), and Sp ₂ and Sp ₃ may be the same as or different from each other. An ultraviolet-absorbing group is bonded to at least one of Sp ₂ and Sp ₃ directly or via a spacer, or at least one of Sp ₂ and Sp is a part or all of the ultraviolet-absorbing group of the polymer main chain. Forming part. Specific examples of the linking group and the substituent of Sp ₂ and Sp ₃ are based on Sp ₁ in the general formula (1).

  Examples of the UV-absorbing group include the same groups as those listed as the UV-absorbing group in the general formula (1). Similarly, examples of the spacer include those listed as the spacer in the general formula (1).

  Moreover, the ultraviolet absorbing polymer of the invention of the present invention (a), (b), (c) has an ultraviolet absorbing group represented by the general formulas (3), (4), (5). Any ultraviolet absorbing polymer containing repeating units may be used.

In the general formula (3), R _{12 to} R ₂₅ each have a hydrogen atom, a halogen atom, and a substituent, and examples of the substituent include those of Sp _{1 in} the general formula (1). And the like. R _{12 to} R ₂₅ may be the same or different from each other. In R _{12 to} R ₂₅ , adjacent ones may be bonded to each other to form a ring. The UV-absorbing group represented by the general formula (3) is bonded to the polymer main chain directly or via a spacer at any site, or a part or all of the UV-absorbing group is a polymer main chain. It forms part of the chain. Examples of the spacer include those listed as the spacer in the general formula (1).

In the general formula (4), R ₂₆ and R ₂₇ each represent an alkyl group having 1 to 10 carbon atoms, R ₂₈ , R ₂₉ and R ₃₀ each represent an alkyl group, an alkoxy group, an alkylthio group and an amino group, and X , Y each represents an electron-withdrawing group. Examples of the electron-withdrawing group include those exemplified as examples of EWG _{1 to} EWG ₄ in the general formulas (17) and (18). However, R _{26 to} R ₃₀ and X and Y may have a halogen atom or a substituent, and examples of the substituent are listed as examples of the substituent that Sp ₁ can take in the general formula (1). And the like. R _{26 to} R ₃₀ may be the same as or different from each other. The alkyl group, alkoxy group, alkylthio group, and amino group may have a substituent or may be unsubstituted.

However, R _{26 to} R ₃₀ , X, and Y may be connected to each other to form a 5- or 6-membered ring. However, the ultraviolet absorbing group represented by the general formula (4) is bonded to the polymer main chain directly or via a spacer at any site, or a part or all of the ultraviolet absorbing group is overlapped. It forms part of the combined main chain. Examples of the UV-absorbing group include the same groups as those listed as the UV-absorbing group in the general formula (1). Similarly, examples of the spacer include those listed as the spacer in the general formula (1).

In the general formula (5), R _{66 to} R ₇₁ each represent a hydrogen atom, a halogen atom, or a substituent. Preferably, R _{66 to} R ₇₀ are a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an amino group, or an alkyl group. An amino group is mentioned, and _R71 is a hydrogen atom, a halogen atom or an alkyl group. However, R _{66 to} R ₇₀ may be connected to each other to form a 5- or 6-membered ring. X and Y are synonymous with X and Y in the general formula (4). In R _{66 to} R ₇₀ , adjacent ones may be bonded to each other to form a ring. In the ultraviolet absorbing group represented by the general formula (5), X and Y are not bonded to each other to form a ring. However, the ultraviolet absorbing group represented by the general formula (5) is bonded to the polymer main chain directly or via a spacer at any site, or a part or all of the ultraviolet absorbing group is overlapped. It forms part of the combined main chain. Examples of the UV-absorbing group include the same groups as those listed as the UV-absorbing group in the general formula (1). Similarly, examples of the spacer include those listed as the spacer in the general formula (1).

  The ultraviolet absorbing polymer of the inventions of (d) and (e) may be any ultraviolet absorbing polymer containing the repeating units represented by the general formulas (6) and (7). . The ultraviolet absorbing polymer having either the repeating unit represented by the general formula (6) or the repeating unit represented by the general formula (7) is a copolymer with an ethylenically unsaturated monomer. It is preferable.

In the general formulas (6) and (7), R _{31 to} R ₃₄ each represent a halogen atom or a substituent. Examples of the substituent are listed as examples of the Sp ₁ substituent in the general formula (1). And the like. l represents 0, 1, 2, 3, m represents 0, 1, 2, 3, 4, s represents 0, 1, 2, 3, 4, o represents 0, 1, 2, 3, J _{4 are, * - O -, * -} NR 1 -, * - S -, * - SO -, * - SO 2 -, * - POO -, * - CO -, * - COO -, * - NR 2 _{CO -, * - NR 3 COO} -, * - NR 4 CONR 5 -, * - OCO -, * - OCONR 6 -, * - CONR 7 -, * - NR 8 SO -, * - NR 9 SO 2 -, * -SONR ₁₀ -and * -SO ₂ NR ₁₁ -are represented (note that * indicates that they are connected to an ultraviolet-absorbing group with *), preferably * -O-, * -NR _{1-. , * - S -, * -} SO -, * - SO 2 -, * - NR 3 COO -, * - NR 4 CONR 5 - a. J _{5 is, * - O -, * -} NR 1 -, * - S -, * - SO -, * - SO 2 -, * - POO -, * - CO -, * - COO -, * - NR 2 _{CO -, * - NR 3 COO} -, * - NR 4 CONR 5 -, * - OCO -, * - OCONR 6 -, * - CONR 7 -, * - NR 8 SO -, * - NR 9 SO 2 -, * -SONR ₁₀ -and * -SO ₂ NR ₁₁ -are represented (note that * indicates that it is connected to a UV-absorbing group (on the side opposite to Sp ₄ ) with *), preferably *- _{O -, * - NR 1 -} , * - S -, * - SO -, * - SO 2 -, * - NR 3 COO -, * - NR 4 CONR 5 - a. R ₁ to R ₁₁ has the same meaning as _R 1 _{to R 11} in the general formula (1). Sp ₄ and Sp ₅ represent a divalent linking group and may have a halogen atom or a substituent. Specific examples of the linking group and the substituent are based on Sp ₁ in the general formula (1). When l is 2 or 3, R ₃₁ may be the same as or different from each other. When m is any of 2, 3, and 4, R ₃₂ may be the same as or different from each other. When o is 2 or 3, R ₃₄ may be the same as or different from each other. When s is 2, 3, or 4, R ₃₃ may be the same as or different from each other.

  In the general formulas (6) and (7), it is preferable that s and o or l and m are not 0.

  The ultraviolet absorbing polymer of the invention of (f) may be any as long as it contains a copolymer derived from the compounds represented by the general formulas (8) and (9).

In the general formulas (8) and (9), R ₃₅ and R ₃₆ each represent a halogen atom and a substituent. Examples of the substituent include those Sp ₁ in the general formula (1) is exemplified as substituents which may be taken. R ₃₅ and R ₃₆ may be the same as or different from each other. q represents 0, 1, 2, 3, 4; r represents 0, 1, 2, 3; When r is 2 or 3, R ₃₆ may be the same as or different from each other. When q is 2, 3, or 4, R ₃₅ may be the same or different from each other. R _{37 to} R ₃₉ each represent any of a hydrogen atom, a halogen atom, and a substituent. Sp ₆ represents a divalent linking group and may have a halogen atom or a substituent. In Sp ₆ , specific examples of the linking group and the substituent are based on Sp ₁ of the general formula (1).

  The ultraviolet absorbing polymer of the invention of (g) may be any modified cellulose as long as the ultraviolet absorbing group is bonded directly or via a spacer to either a hydroxyl group of cellulose or a cellulose derivative. . A UV-absorbing group is bonded to a hydroxyl group of cellulose or a cellulose derivative via a spacer means that at least one UV-absorbing group is directly or spacer to any one of the three hydroxyl groups of the repeating unit of cellulose. The UV-absorbing group can be exemplified by those exemplified as the UV-absorbing group in the general formula (1), and the spacer is also exemplified as the spacer in the general formula (1). Can give. This UV-absorbing polymer has a very good compatibility with cellulose because the repeating unit is a cellulose derivative, which has been a problem during saponification during the manufacturing process of a cellulose film or with an alkali treatment liquid. It is stable with no bleeding phenomenon or crystal precipitation.

  The ultraviolet absorbing polymer of the present invention is a polymer containing a repeating unit represented by the general formulas (1), (2), (6), (7), the general formulas (3), (4), Either a polymer containing a repeating unit having an ultraviolet absorbing group represented by (5), a copolymer derived from the compounds represented by the general formulas (8) and (9), or a hydroxyl group of cellulose And a copolymer derived from the repeating unit of the present invention or the compound of the present invention, containing at least one kind selected from modified cellulose bonded with an ultraviolet absorbing group directly or through a spacer. As long as it contains, it may be a homopolymer or a copolymer with a plurality of other continuous units.

  Other continuous units include, for example, acrylamide derivative-containing monomers, acrylic ester derivative-containing monomers, methacrylic ester derivative-containing monomers, vinyl ether derivative-containing monomers, ethylene oxide derivative-containing monomers, vinyl ester derivative-containing monomers, dicarboxylic acid derivative-containing monomers, Examples thereof include continuous units obtained from diol derivative-containing monomers and diamine derivative-containing monomers.

  When the ultraviolet-absorbing polymer of the present invention or the modified cellulose is used as a copolymer, it is preferably a copolymer with an ethylenically unsaturated monomer. More preferably, the ethylenically unsaturated monomer is a methacrylic acid ester having a hydroxyl group or an ether bond, or an acrylic acid ester having a hydroxyl group.

  Preferred examples are given below. Methacrylic acid and its ester derivatives (methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, octyl methacrylate, cyclohexyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, tetrahydrofurfuryl methacrylate, benzyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc.) or acrylic acid and its ester derivatives (methyl acrylate, ethyl acrylate, propyl acrylate, Butyl acrylate, i-butyl acrylate, t-butyl acrylate, octyl acrylate, cyclohexyl acrylate, 2-hydroxyethyl acrylate, 2-acrylate Droxypropyl, tetrahydrofurfuryl acrylate, benzyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, etc.), alkyl vinyl ether (methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, etc.), alkyl vinyl ester (vinyl formate, vinyl acetate) , Vinyl butyrate, vinyl caproate, vinyl stearate, etc.), acrylonitrile, vinyl chloride, styrene and the like can be mentioned as preferred examples.

  Among these ethylenically unsaturated monomers, acrylic acid ester having a hydroxyl group or ether bond, or methacrylic acid ester (for example, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, tetrahydrofurfuryl acrylate, acrylic acid) 2-Ethoxyethyl, diethylene glycol ethoxylate acrylate, 3-methoxybutyl acrylate) are preferred. These may be used alone or in combination of two or more, and copolymerized with the ultraviolet absorbing monomer.

  Moreover, it is preferable that content of an ultraviolet absorptive monomer in an ultraviolet absorptive polymer is 1-70 mass% or more. More preferably, it is 20-70 mass%, Furthermore, it is preferable that it is 30-60 mass%. In particular, when the ultraviolet absorbing polymer is a copolymer of a repeating unit represented by the general formula (6) and an ethylenically unsaturated monomer, it is represented by the general formula (6) in the ultraviolet absorbing polymer. The content of the repeating unit is preferably 1 to 45% by mass, more preferably 10 to 45% by mass, and still more preferably 20 to 40% by mass. In particular, it is preferable that the content of the repeating unit represented by the general formula (7) in the ultraviolet absorbing polymer is 1 to 55% by mass. More preferably, it is 10-55 mass%, More preferably, it is 20-50 mass%.

  It is preferable to mix the polymer used for this invention in the ratio of 0.01-40 mass% with respect to a cellulose ester, More preferably, it is preferable to mix in the ratio of 0.01-30 mass%. In addition, when the film thickness of a cellulose-ester film is 65 micrometers or less, 1-10 mass% is preferable, More preferably, it is 1-5 mass%. Moreover, when the film thickness of a cellulose ester is 70 micrometers or more, 0.5-5 mass% is preferable, More preferably, it is 0.5-2.5 mass%. If the haze at the time of forming the cellulose ester film at this time is 0 to 0.5, the haze is not particularly limited, but the haze is preferably 0.2 or less. More preferably, the haze when the cellulose ester film is formed is 0 to 0.2, and the transmittance at 380 nm is 0 to 10%.

  In addition, the ultraviolet absorbing polymer of the present invention can be used together with other low molecular compounds, high molecular compounds, inorganic compounds, etc. when mixed with cellulose ester. For example, it is also a kind of preferable aspect to mix the ultraviolet-absorbing polymer of this invention and another low molecular weight ultraviolet absorber simultaneously with a cellulose-ester film.

  Although the polymer of this invention can be used without a restriction | limiting especially if it is except a monomer, The weight average molecular weight of a preferable polymer is 500-1 million, Most preferably, it is 1000-100,000. More preferably, it is 2000-20000, Furthermore, it is 7000-15000.

  The polymerization method of the polymer of the present invention is not particularly limited, and examples thereof include radical polymerization, anionic polymerization, and cationic polymerization. Examples of the initiator for the radical polymerization method include azo compounds and peroxides, and examples thereof include azobisisobutyronitrile (AIBN), azobisisobutyric acid diester derivatives, and benzoyl peroxide.

  The polymerization solvent is not particularly limited. For example, aromatic hydrocarbon solvents such as toluene and chlorobenzene, halogenated hydrocarbon solvents such as dichloroethane and chloroform, ether solvents such as tetrahydrofuran and dioxane, and amide solvents such as dimethylformamide. And alcohol solvents such as methanol, ester solvents such as ethyl acetate, ketone solvents such as acetone, water solvents and the like. Depending on the selection of the solvent, solution polymerization that polymerizes in a homogeneous system, precipitation polymerization that precipitates the produced polymer, and emulsion polymerization that polymerizes in a micelle state can also be performed.

  The ultraviolet-absorbing polymer of the present invention has a good compatibility with cellulose and a high molecular weight as compared with conventionally known low-molecular-weight ultraviolet absorbers and the like. The bleeding phenomenon and crystal precipitation, which are problems when saponifying with a liquid, do not occur. Furthermore, the generation of haze is extremely small, the polymer itself is sufficiently stable against ultraviolet rays, heat and humidity, and there is almost no deterioration in ultraviolet absorption properties even when exposed to high temperatures and high humidity, and resistance to moisture and heat. Excellent cellulose ester film can be obtained.

  The polarizing plate of the present invention has a first polarizing plate protective film, a polarizer, and a second polarizing plate protective film. At least one of the first polarizing plate protective film or the second polarizing plate protective film is the cellulose ester film of the present invention.

(Preparation method of polarizing plate)
The polarizing plate can be produced by a general method. For example, there is a method in which a cellulose ester film of the present invention is alkali-treated and bonded to both surfaces of a polarizing film produced by immersing and stretching in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution. The alkali saponification treatment is a treatment in which the cellulose ester film is immersed in a high-temperature strong alkaline solution in order to improve the wetness of the aqueous adhesive and improve the adhesiveness.

  The cellulose ester film of the present invention will be described.

  As the cellulose ester used in the present invention, the cellulose ester is preferably a lower fatty acid ester.

  The lower fatty acid in the lower fatty acid ester of cellulose ester means a fatty acid having 6 or less carbon atoms. For example, cellulose acetate, cellulose propionate, cellulose butyrate and the like are preferable examples of the lower fatty acid ester of cellulose.

  In addition to the above, mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate described in JP-A Nos. 10-45804, 8-231761, and US Pat. No. 2,319,052 are used. I can do it.

  Among the above description, cellulose triacetate is particularly preferably used as the lower fatty acid ester of cellulose.

  Furthermore, from the viewpoint of base strength, a polymerization degree of 250 to 400 and a total substitution degree of 2.3 to 3.0 are particularly preferable, and 2.6 to 2.8 is particularly preferable. Alternatively, cellulose acetate propionate having a total substitution degree of 2.3 to 2.8, an acetyl substitution degree of 1.5 to 2.5, and a propionyl substitution degree of 0.1 to 1.0 is preferably used.

  As the cellulose triacetate, either cellulose triacetate synthesized from cotton linter or cellulose triacetate synthesized from wood pulp can be used alone or in combination. If peelability from the belt or drum becomes a problem, it is preferable to use a large amount of cellulose triacetate synthesized from a cotton linter that has good peelability from the belt or drum. When cellulose triacetate synthesized from wood pulp is mixed and used, the ratio of cellulose triacetate synthesized from cotton linter is preferably 40% by mass or more, and the effect of releasability becomes remarkable, more preferably 60% by mass or more. Most preferably, it is used alone.

  The polarizing film, which is the main component of the polarizing plate of the present invention, is an element that allows only light of a polarization plane in a certain direction to pass through. A typical polarizing film currently known is a polyvinyl alcohol polarizing film. There are one in which iodine is dyed on a polyvinyl alcohol film and one in which a dichroic dye is dyed. These are formed by forming a polyvinyl alcohol aqueous solution into a film and dyeing it by uniaxial stretching or dyeing and then uniaxially stretching, and then performing a durability treatment with a boron compound. A transparent cellulose ester film, which is a protective film for a polarizing plate of the present invention, is laminated on the surface of the polarizing film to form a polarizing plate.

  The manufacturing method of the cellulose-ester film of this invention is demonstrated.

  In the present invention, the dope solution in which the cellulose ester is dissolved is a state in which the cellulose ester is dissolved in a solvent (solvent), and a plasticizer is added to the dope solution, and other additives as necessary. Can also be added. As a density | concentration of the cellulose ester in dope liquid, 10-30 mass% is preferable, More preferably, it is 18-20 mass%.

  The solvent used in the present invention may be used alone or in combination, but it is preferable to use a mixture of a good solvent and a poor solvent from the viewpoint of production efficiency, and more preferably, the mixing ratio of the good solvent and the poor solvent is good. A solvent is 70-95 mass%, and a poor solvent is 30-5 mass%.

  With the good solvent and the poor solvent used in the present invention, those that dissolve the cellulose ester used alone are defined as good solvents, and those that swell or do not dissolve alone are defined as poor solvents. Therefore, depending on the amount of acetic acid bonded to the cellulose ester, the good solvent and the poor solvent change. For example, when acetone is used as the solvent, the amount of the acetic acid bonded to the cellulose ester is 55% and the amount of the acetic acid is 60%. turn into.

  Examples of the good solvent used in the present invention include organic halogen compounds such as methylene chloride and dioxolanes.

  Depending on the amount of acetic acid bound to the cellulose ester, examples of a solvent that can be a good solvent and a poor solvent include acetone, methyl acetate, and ethyl acetate.

  As the poor solvent used in the present invention, for example, methanol, ethanol, n-butanol, cyclohexane and the like are preferably used.

  As a method for dissolving the cellulose ester when preparing the dope described above, a general method can be used. However, as a preferable method, the cellulose ester is mixed with a poor solvent and wetted or swollen. A method of mixing with a good solvent is preferably used. At this time, under pressure, the method of heating at a temperature not lower than the boiling point of the solvent at a room temperature and in a range where the solvent does not boil and dissolving while stirring prevents the occurrence of massive undissolved material called gel or mamako. More preferable.

  The pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or by increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside. For example, a jacket type is preferable because temperature control is easy.

  The heating temperature with the addition of the solvent is preferably a temperature not lower than the melting point of the solvent used and in a range where the solvent does not boil, for example, 60 ° C. or higher and 70 to 110 ° C. is preferable. The pressure is adjusted at a set temperature so that the solvent does not boil.

  After dissolution, it is taken out from the container while cooling, or extracted from the container with a pump or the like and cooled with a heat exchanger or the like, and used for film formation. Although the cooling temperature at this time may be cooled to room temperature, it is more preferable to cool to a temperature 5 to 10 ° C. lower than the boiling point and perform casting at that temperature because the dope viscosity can be reduced.

  As the support in the casting step, a support obtained by mirror-finishing belt-shaped or drum-shaped stainless steel is preferably used. The temperature of the support in the casting process can be cast in a general temperature range of 0 ° C. to a temperature lower than the boiling point of the solvent, but the dope is gelled by casting on a support at 0 to 30 ° C. In order to increase the peeling limit time, it is preferable, and it is more preferable to cast it on a support at 5 to 15 ° C. The peeling limit time is the time during which the cast dope is on the support at the limit of the casting speed at which a transparent and flat film can be continuously obtained. A shorter peeling limit time is preferable because of excellent productivity.

  The surface temperature of the support on the side to be cast (cast) is 10 to 55 ° C., the temperature of the solution is 25 to 60 ° C., and the temperature of the solution is preferably higher than the temperature of the support by 0 ° C. or more, More preferably, it is set to 5 ° C. or higher.

  The higher the solution temperature and the support temperature, the faster the solvent can be dried. However, if the temperature is too high, foaming or flatness may be deteriorated.

  A more preferable range of the temperature of the support is 20 to 40 ° C, and a more preferable range of the solution temperature is 35 to 45 ° C.

  Moreover, since the adhesive force of a film and a support body can be reduced by making the support body temperature at the time of peeling into 10-40 degreeC, More preferably, 15-30 degreeC, it is preferable.

  In order for the cellulose ester film during production to exhibit good flatness, the residual solvent amount when peeling from the support is preferably 10 to 80%, more preferably 20 to 40%, particularly preferably. 20-30%.

  In the present invention, the amount of residual solvent is defined by the following formula.

Residual solvent amount = (mass before heat treatment−mass after heat treatment) / (mass after heat treatment) × 100%
In addition, the heat treatment when measuring the residual solvent amount represents that the film is heat treated at 115 ° C. for 1 hour.

  Peeling is usually performed at a peeling tension of 196 to 245N (20 to 25 kgf) / m when peeling the support and the film. However, the content of the UV absorber per unit mass of the cellulose ester is large, and conventionally Since the cellulose ester film of the present invention which is made thinner than the above is easily wrinkled at the time of peeling, it is preferably peeled with a force within 167 N (17 kgf) / m from the lowest tension that can be peeled, more preferably It is peeling with the force within 137N (14kgf) / m from the lowest tension.

  Moreover, in the drying process of the cellulose ester film, the film peeled off from the support is further dried, and the residual solvent amount is preferably 3% by mass or less, more preferably 0.5% by mass or less.

  In the film drying process, generally, a method of drying while transporting the film by a roll suspension method or a pin tenter method is adopted. For the liquid crystal display member, it is preferable to dry while maintaining the width by a pin tenter method in order to improve the dimensional stability. In particular, it is particularly preferable to maintain the width in a large amount of residual solvent immediately after peeling from the support because the effect of improving dimensional stability is more exhibited. The means for drying the film is not particularly limited, and is generally performed with hot air, infrared rays, a heating roll, microwaves, or the like. It is preferable to carry out with hot air in terms of simplicity. The drying temperature is preferably divided into 3 to 5 stages in the range of 40 to 150 ° C and gradually increased, and more preferably in the range of 80 to 140 ° C in order to improve dimensional stability.

  The cellulose ester film of the present invention preferably contains a plasticizer. The plasticizer that can be used is not particularly limited, but in the phosphate ester type, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, etc. For phthalate esters, diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, etc. For glycolate esters, triacetin, tributyrin, butyl phthalyl butyl glycolate, ethyl phthalyl Ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, etc. are preferably used alone or in combination. There.

  By containing these plasticizers, a film having excellent dimensional stability and water resistance can be obtained, which is particularly preferable.

  In the present invention, the combined use of the above-described ultraviolet absorber and a plasticizer having a melting point of 20 ° C. or lower among these plasticizers is excellent in workability, and is preferable in terms of foreign matter failure and surface quality. The plasticizer having a melting point of 20 ° C. or lower is not particularly limited as long as the melting point is 20 ° C. or lower, and can be selected from the above plasticizers. Examples thereof include tricresyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, diethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, triacetin, ethyl phthalyl ethyl glycolate and the like. These plasticizers are also preferably used alone or in combination.

  The melting point in the present invention is the true melting point described in the Chemical Dictionary of Kyoritsu Publishing Co., Ltd.

  The amount of these plasticizers used is preferably 1 to 15% by mass with respect to the cellulose ester in terms of film performance and processability. For a liquid crystal display member, 5 to 15% by mass is more preferable from the viewpoint of dimensional stability, and 7 to 12% by mass is particularly preferable.

  Moreover, 1 mass%-10 mass% are preferable, and, as for content of the plasticizer whose melting | fusing point is 20 degrees C or less with respect to a cellulose ester, More preferably, they are 3 mass%-7 mass%.

  Processability is the ease of processing when slitting or punching a base film or liquid crystal display member. If the processability is poor, the cut surface will be sawtoothed, generating chips and adhering to the product. This is not preferable because it causes a foreign matter failure.

  The cellulose ester film of the present invention is preferably used for a liquid crystal display member because of its high dimensional stability and good ultraviolet cut performance. A liquid crystal display member is a member used in a liquid crystal display device. For example, a polarizing plate, a protective film for a polarizing plate, a retardation plate, a reflective plate, a viewing angle improving film, an antiglare film, an antireflective film, and a charge Prevention films and the like. Among the above descriptions, the cellulose ester film of the present invention is more preferably used in polarizing plates and protective films for polarizing plates that have strict requirements on dimensional stability.

  Although the cellulose ester film of this invention is based also on a use, it is preferable that thickness is 5-200 micrometers, More preferably, it is 10-100 micrometers, Most preferably, it is 20-65 micrometers.

  If necessary, fine particles may be added to the optical film of the present invention as a matting agent. As examples of the inorganic compound as fine particles used in the present invention, silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, Mention may be made of aluminum silicate, magnesium silicate and calcium phosphate. Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable. Silicon dioxide fine particles are commercially available, for example, under the trade names Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (above Nippon Aerosil Co., Ltd.). it can. Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used.

  Among these, Aerosil 200V and Aerosil R972V are particularly preferable because they have a great effect of reducing the friction coefficient while keeping the turbidity of the optical film low.

  Examples of the polymer include silicone resin, fluorine resin, and acrylic resin. Silicone resins are preferable, and those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, 105, 108, 120, 145, 3120, and 240 (manufactured by Toshiba Silicone Co., Ltd.) It is marketed by name and can be used.

  Next, the optical compensation film of the present invention will be described.

  The optical compensation film is a film having optical anisotropy that can be used mainly for a liquid crystal display device, and is generally produced by providing an optical anisotropic layer on a support film.

  The optical compensation film of the present invention uses the cellulose ester film described in (1) or (2) of the present invention as a support, and has an optically anisotropic layer thereon. The compound preferably used for the optically anisotropic layer is a discotic compound, a biaxial liquid crystalline compound, or a rod-like liquid crystalline compound, and more preferably a discotic liquid crystalline compound having a nematic phase or a biaxial having a nematic phase. Liquid crystal compound, a rod-like liquid crystal compound having a nematic phase.

  Examples of discotic compounds include benzene derivatives, cyclohexane derivatives, azacrown macrocycles, phenylacetylene macrocycles, triphenylene derivatives, truxene derivatives, phthalocyanine derivatives, anthraquinone derivatives, fulvalene derivatives, bipyranylidene derivatives, β-diketone complexes, and the like. It is done. More preferably, a discotic liquid crystalline compound having a structure in which such a discotic compound is used as a mother nucleus at the center of a molecule and a linear alkyl group, an alkoxy group, a substituted benzoyloxy group, or the like is radially substituted as a side chain thereof. It is done. However, the molecule itself is not limited to the above description as long as it has negative uniaxiality and can give a certain orientation.

  A biaxial liquid crystalline compound is a liquid crystalline compound having two optical axes in a liquid crystal state. In other words, when the refractive index in the triaxial direction of the liquid crystal phase is nx, ny, nz in ascending order, it is a liquid crystalline compound that satisfies the relationship of nx <ny <nz. For example, Handbook of Liquid Crystals Chapter XV Biaxial Nematic Liquid Examples thereof include liquid crystal compounds as described in Crystals. However, the present invention is not limited to the above description as long as the refractive indexes in one direction and another direction are all different and can provide a certain orientation.

  A rod-like liquid crystal compound is the most general liquid crystal compound and is a generic name for compounds whose molecular shape can be regarded as a rod shape. The molecular shape can be regarded as a rod-like shape when the major axis of the molecule is a and the minor axis of the molecule is b. If a / b is sufficiently large, it is said to be rod-shaped, preferably a / b ≧ 2, more preferably a / b ≧ 3. However, the molecule is not limited to the above description as long as the molecule itself has positive uniaxiality and can give a certain orientation.

  These compounds are composed of a compound alone or a composition containing at least one kind of the compound. These compounds may be either low-molecular or high-molecular compounds, but they are fixed without impairing the alignment form in the liquid crystal state. In order to make these compounds, these compounds are mixed into the polymer, or cooled while maintaining the alignment state from the liquid crystal phase formation temperature, or a polymerizable group is introduced into the liquid crystalline compound, and a polymerization initiator is introduced. After the composition added with is heated to the liquid crystal phase formation temperature, the alignment state may be stably fixed by a polymerization reaction.

  Materials for the protective film include polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene-maleic anhydride maleic copolymer, polyvinyl alcohol, N-methylol acrylamide, styrene-vinyl toluene copolymer, chlorosulfonated polyethylene. Nitrocellulose, polyvinyl chloride, polyolefin chloride, polyester, polyimide, vinyl acetate-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, polyethylene, polypropylene, polycarbonate and other high-molecular substances, silane coupling agents, etc. Can be mentioned. Cumulative films formed by Langmuir-Blodget (LB method) such as ω-tricosanoic acid, dioctadecyldimethylammonium chloride and methyl stearate can also be used.

  As the light for polymerization, electron beam, ultraviolet ray, visible ray, and infrared ray (heat ray) are preferable, and ultraviolet ray is more preferable. In general, radical polymerization or cationic polymerization using a photopolymerization initiator by ultraviolet rays has a very high polymerization rate and is preferable in terms of productivity in the production process. As the radical light source, a low-pressure mercury lamp, a high-pressure discharge lamp, and a short arc discharge lamp are preferably used, and a high-pressure discharge lamp is more preferably used.

  The optical compensation film of the present invention is a film for performing viewing angle compensation of a liquid crystal display element, preferably a director having different directors on the upper and lower surfaces of the film, and more preferably gradually changing in the film thickness direction. It is the film which has formed the hybrid orientation.

  In order to obtain the hybrid alignment of the present invention, it is desirable to sandwich the upper and lower sides of the liquid crystal material at different interfaces, or to use an electric field, a magnetic field, etc. As a specific aspect, a single substrate and an air interface are used. The lower interface of the liquid crystal layer is in contact with the substrate, and the upper interface is in contact with air. It is preferable to apply on the support in a state where one interface is in contact with the gas phase.

  The alignment substrate that can be preferably used in the present invention has a function of defining the alignment direction of the compound of the optically anisotropic layer. The alignment substrate is formed by rubbing treatment of an organic compound (preferably polymer), oblique deposition of an inorganic compound, formation of a layer having a microgroove, or an organic compound (eg, ω-tricosanoic acid) by the Langmuir-Blodgett method (LB film). , Dioctadecylmethylammonium chloride, methyl stearylate). Furthermore, an alignment substrate that generates an alignment function by application of an electric field, application of a magnetic field, or light irradiation can also be used.

  The optical compensation film of the present invention is obtained by applying the liquid crystalline compound on these alignment substrates, and then performing a uniform alignment process and an immobilization process. Coating on the substrate can be performed using a solution in which the material is dissolved in various solvents or a solution in which the material is melted. In the process, a solution in which a liquid crystal compound is dissolved in the solvent is used. The solution coating is preferably applied.

  These solutions are then applied onto the alignment substrate described above. Examples of the coating method include vapor deposition, spin coating, dip coating, and extrusion coating. After coating, the solvent is removed, and a layer having a uniform thickness is first formed on the substrate. Usually, the solvent is removed using air drying at room temperature, drying on a hot plate, drying in a drying furnace, blowing hot air or hot air, and the like.

  Thereafter, in order to align, heat treatment is preferably performed, and the heat treatment is performed at a temperature higher than the liquid crystal transition point of the liquid crystalline compound. That is, the liquid crystal compound is aligned in the liquid crystal state, or is changed to a temperature range that exhibits a liquid crystal phase after being changed to an isotropic liquid state that is higher than the temperature range that exhibits a liquid crystal phase. . Usually, the temperature of the heat treatment is performed in a range of 0 ° C to 200 ° C, and a range of 20 ° C to 150 ° C is particularly preferable.

  In the present invention, in the above heat treatment step, a magnetic field or an electric field may be used to align the liquid crystalline compound. The alignment state thus obtained is then cooled or polymerized by light, heat or the like to fix the alignment state without impairing it, and the optical compensation film of the present invention is obtained.

  The optical compensation film of the present invention thus obtained can exhibit a suitable optical compensation effect by using one or a plurality of the optical compensation films for a liquid crystal display.

  Although the example of a polymerization of an ultraviolet absorptive polymer is described below, this invention is not limited to these (polymerization examples 1-9).

<Polymerization example 1>
Synthesis of polymer A (general formula (2))

  Add 0.02 g of antimony oxide to 11.83 g (20 mmol) of dihydroxybenzotriazole (a) and 2.92 g (20 mmol) of adipic acid (b), and place in a polymerization tube equipped with a vacuum stirrer. A nitrogen gas introduction tube was connected to the polymerization tube, and this polymerization tube was put in an oil bath and slowly passed with nitrogen gas while being heated to 180 ° C. While stirring, the temperature was gradually raised to 270 ° C., and at the same time the degree of vacuum was increased to 102 Pa. After heating for 3 hours as it was, it was allowed to cool and polymer A was obtained quantitatively. As a result of measuring the molecular weight of the polymer A by GPC, the number average molecular weight was 12,500. The structure of the polymer was confirmed by 1H-NMR.

<Polymerization example 2>
Synthesis of polymer B (general formulas (2) and (3))

  Add 0.02 g of antimony oxide to 10.35 g (20 mmol) of pentahydroxytriazine (c) and 2.64 g (20 mmol) of glutaric acid (d), and put into a polymerization tube equipped with a vacuum stirrer. A nitrogen gas introduction tube was connected to the polymerization tube, and this polymerization tube was put in an oil bath and slowly passed with nitrogen gas while being heated to 180 ° C. While stirring, the temperature was gradually raised to 270 ° C., and at the same time the degree of vacuum was increased to 102 Pa. After heating for 3 hours as it was, it was allowed to cool and polymer B was obtained quantitatively. As a result of measuring the molecular weight of the polymer B by GPC, the number average molecular weight was 23,000. The structure of the polymer was confirmed by 1H-NMR.

<Polymerization Example 3>
Synthesis of polymer C (general formula (7))

  7.18 g (20 mmol) of acrylic monomer (e) and 10.75 g (125 mmol) of acrylic monomer (f) were placed in a 100 ml three-headed Kolben, and the pressure was reduced by a vacuum pump, followed by nitrogen substitution three times. Dissolved in 60 ml of dehydrated tetrahydrofuran under nitrogen and heated to reflux. To this solution was added AIBN, 1.16 g (7.25 mmol) in tetrahydrofuran, and the mixture was heated to reflux for 3 hours. The solvent of the reaction solution was distilled off under reduced pressure, then dissolved in a small amount of tetrahydrofuran and reprecipitated with acetone. The precipitate was collected by filtration to obtain polymer C. As a result of measuring the molecular weight of the polymer C by GPC, the number average molecular weight was 16,800. Moreover, the structure of the polymer confirmed by 1H-NMR that the unit ratios of the acrylic monomer (e) and the acrylic monomer (f) were 40% by mass and 60% by mass, respectively.

<Polymerization example 4>
Synthesis of polymer D (general formulas (8) and (9))

  6.46 g (20 mmol) of methacrylic monomer (g) and 4.31 g (50 mmol) of vinyl acetate monomer (h) were placed in a 100 ml three-headed Kolben, and the pressure was reduced by a vacuum pump, followed by nitrogen substitution three times. Dissolved in 20 ml of dehydrated tetrahydrofuran under nitrogen and heated to reflux. A solution of AIBN, 0.57 mg (3.5 mmol) in tetrahydrofuran was added to this solution, and the mixture was heated to reflux for 3 hours. The solvent of the reaction solution was distilled off under reduced pressure, then dissolved in a small amount of tetrahydrofuran and reprecipitated with acetone. The precipitate was collected by filtration to obtain a polymer D. As a result of measuring the molecular weight of the polymer D by GPC, the number average molecular weight was 19,500. Moreover, the structure of the polymer confirmed by 1H-NMR that the unit ratios of the methacrylic monomer (g) and the vinyl acetate monomer (h) were 50% by mass and 50% by mass, respectively.

<Polymerization example 5>
Synthesis of polymer E

  10.0 g of diacetylcellulose was placed in a 100 ml three-headed Kolben, 20 ml of tetrahydrofuran, 11.0 g (80 mmol) of potassium carbonate, and 16.0 g (50 mmol) of an alkyl halide monomer (i) were added and heated to reflux for 3 hours. The solvent of the reaction solution was distilled off under reduced pressure, then dissolved in a small amount of DMF, and reprecipitated with hexane. The precipitate was collected by filtration to obtain a polymer E. The structure of the polymer E was confirmed by 1H-NMR.

<Polymerization Example 6>
Synthesis of polymer F (general formula (6))

  Vinyl monomer (j) 4.09 g (10 mmol), vinyl monomer (k) 2.53 g (9 mmol), vinyl monomer (l) 9.50 g (95 mmol) were placed in a 100 ml three-headed Kolben, and the pressure was reduced by a vacuum pump. Thereafter, nitrogen substitution was performed three times. Dissolved in 60 ml of dehydrated tetrahydrofuran under nitrogen and heated to reflux. To this solution was added a solution of AIBN, 0.93 g (5.7 mmol) in tetrahydrofuran, and the mixture was heated to reflux for 3 hours. After the solvent of the reaction solution was distilled off under reduced pressure, it was dissolved in a minimum amount of tetrahydrofuran and reprecipitated with acetone. The precipitate was collected by filtration to obtain a polymer F. As a result of measuring the molecular weight of the polymer F by GPC, the number average molecular weight was 21,000. The structure of the polymer was confirmed by 1H-NMR that the unit ratios of vinyl monomer (j), vinyl monomer (k) and vinyl monomer (l) were 25% by mass, 15% by mass and 60% by mass, respectively. .

<Polymerization Example 7>
Synthesis of polymer G (general formula (4))

  After adding 1.94 g (10 mmol) of carboxylic acid monomer (m) and 10 ml of methylene chloride to 100 ml of three-headed colben, 1.50 g (12 mmol) of oxalyl chloride and a few drops of dimethylformamide were added and stirred for about 1 hour. The solvent was removed under reduced pressure to obtain an acid chloride of the carboxylic acid monomer (m). Next, 1.32 g of polyvinyl alcohol (n≈2000) was placed in a 100 ml three-headed Kolben containing an acid chloride of the carboxylic acid monomer (m) and dissolved in 30 ml of tetrahydrofuran and 0.95 g (12 mmol) of pyridine for 3 hours. Stir. The solvent of the reaction solution was distilled off under reduced pressure, then dissolved in a small amount of tetrahydrofuran and reprecipitated with ethyl acetate. The precipitate was collected by filtration to obtain a polymer G. The structure of the polymer G was confirmed by 1H-NMR and IR to be polyvinyl alcohol having a substitution degree of 27%.

<Polymerization Example 8>
Synthesis of polymer H (general formula (5))

  After adding 2.17 g (10 mmol) of carboxylic acid monomer (n) and 10 ml of methylene chloride to 100 ml of three-headed colben, 1.50 g (12 mmol) of oxalyl chloride and a few drops of dimethylformamide were added and stirred for about 1 hour. The solvent was removed under reduced pressure to obtain an acid chloride of the carboxylic acid monomer (n). Next, 1.32 g of polyvinyl alcohol (n≈2000) is placed in a 100 ml three-headed Kolben containing an acid chloride of the carboxylic acid monomer (n) and dissolved in 30 ml of tetrahydrofuran and 0.95 g (12 mmol) of pyridine for 3 hours. Stir. The solvent of the reaction solution was distilled off under reduced pressure, then dissolved in a small amount of tetrahydrofuran and reprecipitated with ethyl acetate. The precipitate was collected by filtration to obtain a polymer H. The structure of the polymer H was confirmed by 1H-NMR and IR to be polyvinyl alcohol having a substitution degree of 25%.

<Polymerization example 9>
Synthesis of polymer I (general formula (1))

A 100 ml three-headed Kolben was decompressed with a vacuum pump and then purged with nitrogen three times. Under nitrogen, 60 ml of dehydrated diethyl ether and 13.34 g (40 mmol) of ethylene oxide monomer (o) were placed in a three-headed Kolben, and 0.06 g (0.4 mmol) of BF ₃ · OEt ₂ was added to this solution, followed by 3 hours at 0 ° C. Stir. After the solvent of the reaction solution was distilled off under reduced pressure, it was dissolved in a minimum amount of tetrahydrofuran and reprecipitated with acetone. The precipitate was collected by filtration to obtain polymer I. As a result of measuring the molecular weight of the polymer I by GPC, the number average molecular weight was 6200. The structure of the polymer was confirmed by 1H-NMR.

<Polymerization Example 10> (Comparison)
Synthesis of polymer J

  2,2′-azobis (2) dissolved in 150 ml of dioxane in 150 ml of three-headed colben in 150 ml of dioxane and heated and stirred at 70 ° C. in a nitrogen stream at 70 ° C. in 50 ml of acrylic monomer (p) and 10 g of acrylic monomer (q) , 4-Dimethylvaleronitrile) 270 mg was added, followed by reaction for 4 hours. The reaction mixture was cooled to room temperature, poured into 2 liters of ice water, and the precipitated solid was collected by filtration to obtain a polymer J. As a result of measuring the molecular weight of the polymer J by GPC, the number average molecular weight was 35,000. The structure of this polymer was confirmed to be a polymer containing 58 mol% of acrylic monomer (p) by 1H-NMR.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, the embodiment of this invention is not limited to these.

Example 1
<Samples 1-12>
(Silicon oxide dispersion)
Aerosil 200V (Nippon Aerosil Co., Ltd.)
(Average primary particle diameter of 12 nm, apparent specific gravity of 100 g / liter)
10 parts by mass Ethanol 90 parts by mass The above was stirred and mixed with a dissolver for 30 minutes, and then dispersed with Manton Gorin. The liquid turbidity after dispersion was 93 ppm.

(Preparation of additive liquid A)
The polymer A 10 parts by weight Methylene chloride 100 parts by weight The above was put into a closed container, heated, stirred and completely dissolved, and filtered.

  To this, 10 parts by mass of the silicon oxide dispersion was added with stirring, and the mixture was further stirred for 30 minutes, followed by filtration to prepare additive liquid A.

(Preparation of dope solution A)
85 parts by weight of triacetyl cellulose synthesized from linter cotton 15 parts by weight of triacetyl cellulose synthesized from wood pulp 2.5 parts by weight of ethylphthalyl ethyl glycolate 9 parts by weight Methylene chloride 475 parts by weight Ethanol 50 parts by weight The above was put into an airtight container, heated, stirred and completely dissolved, filtered, and a dope solution A was prepared.

  To 100 parts by mass of the dope solution, the part of the additive solution shown in Table 1 was added, and the mixture was sufficiently mixed with an in-line mixer (Toray static in-tube mixer Hi-Mixer, SWJ) and filtered. Next, using a belt casting apparatus, the belt was uniformly cast on a stainless steel band support at a temperature of 33 ° C. and a width of 1500 mm. With the stainless steel band support, the solvent was evaporated until the residual solvent amount was 25%, and the film was peeled off from the stainless steel band support with a peeling tension of 127 N (13 kgf) / m. The peeled cellulose triacetate film was slit to 1300 mm width, and then dried while being transported by a number of rolls in a drying zone while being stretched 1.03 times in the width direction by a pin tenter, and slit to 1100 mm width. Film sample 1 was obtained. The film thickness of the cellulose triacetate film at this time was 40 μm.

  Samples 2 to 12 were prepared in the same manner except that the additive solution A of sample 1 was replaced with the following additive solution and addition amount as shown in Table 1.

(Additive solution B)
An additive liquid B was prepared in the same manner except that the polymer A of the additive liquid A was changed to 10 parts by mass of the polymer B.

(Additive liquid C)
An additive liquid C was prepared in the same manner except that the polymer A of the additive liquid A was changed to 10 parts by mass of the polymer C.

(Additive liquid D)
An additive liquid D was prepared in the same manner except that the polymer A of the additive liquid A was changed to 10 parts by mass of the polymer D.

(Additive liquid E)
An additive liquid E was prepared in the same manner except that the polymer A of the additive liquid A was changed to 10 parts by mass of the polymer E.

(Additive solution F)
An additive solution F was prepared in the same manner except that the polymer A of the additive solution A was changed to 10 parts by mass of the polymer F.

(Additive liquid G)
An additive liquid G was prepared in the same manner except that the polymer A of the additive liquid A was replaced with the following ultraviolet absorber.

TINUVIN 109
(Ciba Specialty Chemicals Co., Ltd.) 8 parts by mass 2 parts by mass of the polymer G (additive solution H)
An additive liquid H was prepared in the same manner except that the polymer A of the additive liquid A was replaced with the following ultraviolet absorber.

TINUVIN 109
(Ciba Specialty Chemicals Co., Ltd.) 5 parts by weight Polymer H 5 parts by weight (additive liquid I)
An additive liquid I was prepared in the same manner except that the polymer A of the additive liquid A was changed to 10 parts by mass of the polymer I.

(Additive liquid J)
An additive liquid J was prepared in the same manner except that the polymer A of the additive liquid A was replaced with the following ultraviolet absorber.

TINUVIN 326
(Ciba Specialty Chemicals Co., Ltd.) 5 parts by weight TINUVIN 328
(Ciba Specialty Chemicals Co., Ltd.) 5 parts by mass (additive liquid K)
An additive liquid K was prepared in the same manner except that the polymer A of the additive liquid A was changed to 10 parts by mass of the polymer J.

(Additive liquid L)
An additive liquid L was prepared in the same manner except that the polymer A was not added.

"Measuring method"
(Roll dirt)
After producing a 10000 m cellulose ester film, the degree of soiling of the first roll contacting the film peeled off from the stainless steel band support was visually observed and evaluated according to the following ranks.

A: I do not know at all that the roll is dirty B: I can see that the roll is partially dirty C: I can see that the roll is totally dirty D: The roll is completely dirty You can clearly see that A to C are the levels at which production can continue. D is the level at which production is interrupted and the roll is cleaned.

(Transmittance)
Using Spectrophotometer U-3200 (manufactured by Hitachi, Ltd.), the spectral absorption spectrum of the film was measured, the transmittances at 500 nm and 380 nm were determined, and ranking was performed as follows. The higher the transmittance at 500 nm, the better, and the lower the transmittance at 380 nm, the better.

(500 nm transmittance)
A: Transmittance 92% or more B: Transmittance 90% or more and less than 92% C: Transmittance 85% or more and less than 90% D: Transmittance less than 85% (380 nm transmittance)
A: Transmittance less than 6% B: Transmittance from 6% to less than 10% C: Transmittance from 10% to less than 25% D: Transmittance of 25% or more (Haze)
One film sample was measured according to ASTM-D1003-52 using T-2600DA manufactured by Tokyo Denshoku Industries Co., Ltd., and ranked as follows.

A: Haze less than 0.2% B: Haze 0.2% or more and less than 1% C: Haze 1% or more and less than 5% D: Haze 5% or more (Tear strength)
Plastics specified in JIS-K7128-2-Test method for tear strength of films and sheets-Measured according to the Elmendorf tear method.

(Pressed failure)
When a 10,000 m cellulose ester film was produced, the film was sampled, and the number of pressed failures of 30 μm or more present on the obtained film 1 m ² was counted.

(Preparation of polarizing plate)
A 120 μm thick polyvinyl alcohol film was immersed in 100 kg of an aqueous solution containing 1 kg of iodine and 4 kg of boric acid and stretched 6 times at 50 ° C. to form a polarizing film. Cellulose ester film samples subjected to alkali saponification treatment on both surfaces of this polarizing film were bonded to each other using a completely saponified polyvinyl alcohol 5% aqueous solution as an adhesive to prepare polarizing plates.

(Production of liquid crystal panel)
The polarizing plate of the 15-inch TFT color liquid crystal display LA-1529HM (manufactured by NEC) is peeled off and the liquid crystal cell is sandwiched so that the two polarizing plates thus produced are orthogonal to each other so that the polarizing axis of the polarizing plate remains unchanged. Thus, a 15-inch TFT type color liquid crystal display was produced.

  Two liquid crystal displays made of the cellulose acetate film of sample 12 and a liquid crystal display made of other cellulose acetate film are placed side by side, and JIS-X-9201 high-definition color digital is placed on this liquid crystal display. A bicycle image of an SCID image (CD-ROM manufactured by Japanese Standards Association) produced based on the standard image was displayed, and the resolution and sharpness were evaluated as follows.

(image)
A: The difference in resolution and sharpness does not change compared to the sample 12 B: The resolution and sharpness are slightly deteriorated compared to the sample 12 C: The resolution compared to the sample 12 , The sharpness is clearly degraded

  As apparent from Table 1 above, the UV-absorbing polymer of the present invention is excellent in compatibility with the cellulose ester, so that the occurrence of haze is extremely low, and the tear strength and transmittance are excellent. It can be seen that the roll contamination due to the bleed phenomenon, which has been a problem, and the failure caused by pressing are remarkably improved.

Example 2
Optical compensation films were prepared using the cellulose ester films (Sample 1 to Sample 10) prepared in Example 1 as a support.

(Preparation of optical compensation film (Sample 2-1))
On one side of the cellulose ester film (Sample 1), 2% polyvinyl cinnamate dissolved in methyl ethyl ketone was applied as an alignment film, and this film was irradiated with polarized ultraviolet rays. Spin a coating solution in which a photopolymerization initiator (Irgacure 907 manufactured by Ciba Geigy) and a sensitizer (Kayacure DETX manufactured by Nippon Kayaku Co., Ltd.) are dissolved in a 10% by mass methyl ethyl ketone solution of a discotic liquid crystalline compound (α). Coating was performed at 1000 rpm with a coater to form a coating layer of a liquid crystalline compound. After contacting a metal roller heated to a surface temperature of 95 ° C. for 40 seconds from the support side and aligning the liquid crystal, using a 120 W / cm high-pressure mercury lamp at 95 ° C. for 2 seconds at an illuminance of 600 mW / cm ² After UV irradiation, the film was returned to room temperature, and an optical compensation film coated with a liquid crystal compound-containing layer was produced.

(Sample 2-2)
Sample 2-2 was prepared in the same manner except that the cellulose ester film of Sample 2-1 was changed to Sample 2.

(Sample 2-3)
Sample 2-3 was prepared in the same manner except that the cellulose ester film of Sample 2-1 was changed to Sample 3.

(Sample 2-4)
Sample 2-4 was prepared in the same manner except that the cellulose ester film of Sample 2-1 was changed to Sample 4 and the discotic liquid crystalline compound (α) was changed to the biaxial liquid crystalline compound (β).

(Sample 2-5)
Sample 2-5 was produced in the same manner except that the cellulose ester film of Sample 2-4 was changed to Sample 5.

(Sample 2-6)
Sample 2-6 was produced in the same manner except that the cellulose ester film of Sample 2-4 was changed to Sample 6.

(Sample 2-7)
Sample 2-7 was produced in the same manner except that the cellulose ester film of Sample 2-1 was changed to Sample 7 and the discotic liquid crystalline compound (α) was changed to a rod-like liquid crystalline compound (γ).

(Sample 2-8)
Sample 2-8 was produced in the same manner except that the cellulose ester film of Sample 2-7 was changed to Sample 8.

(Sample 2-9)
Sample 2-9 was produced in the same manner except that the cellulose ester film of Sample 2-7 was changed to Sample 9.

(Sample 2-10)
Sample 2-10 was produced in the same manner except that the cellulose ester film of Sample 2-1 was changed to Sample 10.

(Sample 2-11)
Sample 2-11 was produced in the same manner except that the cellulose ester film of Sample 2-4 was changed to Sample 11.

  About these films, the alignment disorder of the liquid crystal compound was visually observed under crossed Nicols using a polarizing plate, and evaluated according to the following ranks.

A: No alignment disorder of the liquid crystal compound is observed. B: The alignment disorder of the liquid crystal compound is faintly recognized. C: The alignment disorder of the liquid crystal compound is clearly understood. D: The liquid crystal compound is not aligned at all.

  From the results shown in Table 2, the optical compensation film using the cellulose ester film of the present invention does not cause alignment disorder at all, which has been a problem in the past. It can be seen that the orientation of the liquid crystal compound is maintained unchanged even when the rod-like liquid crystal compound is changed.

Claims (4)

A cellulose ester film comprising an ultraviolet-absorbing polymer containing a repeating unit represented by the following general formula (1).

(Wherein J ₁ represents —O—, —NR ₁ —, —S—, —SO—, —SO ₂ —, —POO—, —CO—, —COO—, —NR ₂ CO—, —NR) _{3 COO -, - NR 4 CONR} 5 -, - OCO -, - OCONR 6 -, - CONR 7 -, - NR 8 SO -, - NR 9 SO 2 -, - SONR 10 -, - SO 2 NR 11 - the _represents, R 1 _{to R 11} represents a hydrogen atom, an alkyl group, .Sp ₁ representing the aryl group represents a divalent linking group, a halogen atom, which may have a substituent. However, ultraviolet absorbent to Sp ₁ The group is bonded directly or through a spacer, or a part or all of the ultraviolet absorbing group forms part of the polymer main chain.) A cellulose ester film comprising an ultraviolet absorbing polymer containing a repeating unit represented by the following general formula (2).

(In the formula, J ₂ and J ₃ are synonymous with J ₁ in the general formula (1), and J ₂ and J ₃ may be the same as or different from each other. Sp ₂ and Sp ₃ are the general formulas. (1) It is synonymous with Sp ₁ and Sp ₂ and Sp ₃ may be the same or different from each other, but at least one of Sp ₂ and Sp ₃ has an ultraviolet absorbing group directly or a spacer. Or in at least one of Sp ₂ and Sp ₃ , part or all of the ultraviolet absorbing group forms part of the polymer main chain.)   The ultraviolet absorptive polymer containing the repeating unit represented by the said General formula (1) of Claim 1.   The ultraviolet absorptive polymer containing the repeating unit represented by the said General formula (2) of Claim 2.