JP2007023124A - Cellulose compound composition, cellulose compound film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a cellulose compound composition able to form a film having a preferable retardation value as an optical film and a cellulose compound film having the preferable retardation value as the optical film. <P>SOLUTION: The cellulose compound composition contains at least one species of compounds having at least 2 units in which an aromatic heterocyclic group and an aromatic hydrocarbon ring group are bonded with a single bond. The cellulose compound film comprises the cellulose compound composition. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cellulose compound composition and a cellulose compound film comprising the cellulose compound composition.

  Among cellulose films, the cellulose acetate film is characterized by high optical isotropy (low retardation value) compared to other polymer films. Therefore, it is common to use a cellulose acetate film for an application requiring optical isotropy, for example, a polarizing plate. On the other hand, optical anisotropy (high retardation value) is required for an optical compensation sheet (retardation film) such as a liquid crystal display device. Therefore, it is common to use a synthetic polymer film having a high retardation value such as a polycarbonate film or a polysulfone film as the optical compensation sheet.

Recently, however, cellulose acetate films having a high retardation value that can be used for applications requiring optical anisotropy have been proposed (for example, Patent Document 1 and Patent Document 2). In the disclosed invention, in order to achieve a high retardation value with cellulose triacetate, an aromatic compound having at least two aromatic rings, particularly a compound having a 1,3,5-triazine ring, is added and subjected to stretching treatment. .
In general, cellulose triacetate is a polymer material that is difficult to stretch, and it is known that it is difficult to increase optical anisotropy. However, in Patent Documents 1 and 2, the additives are simultaneously oriented by stretching treatment. Therefore, it is possible to increase the optical anisotropy and realize a high retardation value.

  In recent years, it has become essential to reduce the thickness of a liquid crystal cell in order to reduce the weight of the liquid crystal display device and reduce the manufacturing cost. For this purpose, optical anisotropy (Re: retardation in the film plane) that can be realized with the compound having a 1,3,5-triazine ring described in Patent Documents 1 and 2 is applied to an optical film such as an optical compensation sheet. With respect to the value, Rth: retardation value in the thickness direction of the film, higher Re and lower Rth have been required.

However, as a result of intensive studies on the methods disclosed in Patent Documents 1 and 2, the inventor has a problem that the Re value and the Rth value described above cannot be controlled within a preferable range. found. Therefore, development of new optical performance control technology has become necessary.
European Patent Publication EP0911656A2 JP 2003-344655 A

The first object of the present invention is to provide a cellulose compound composition capable of forming a film having a preferable retardation value as an optical film.
The second object of the present invention is to provide a cellulose compound film having a preferable retardation value as an optical film.

（式中、Ｈａ、Ｈｂはそれぞれ独立に芳香族ヘテロ環基を表し、Ｌは単結合、または２価の連結基を表す。Ｒ_１、Ｒ_２は置換基を表し、それぞれ同じでも異なっていてもよく、可能であれば環を形成してもよい。ｎ、ｍは０以上５以下の整数を表し、それぞれ同じでも異なっていてもよい。）
（３）前記一般式（１）で表される化合物において、Ｈａ、Ｈｂがそれぞれ独立に５員環芳香族へテロ環基であることを特徴とする、（２）項に記載のセルロース化合物組成物。
（４）前記一般式（１）で表される化合物において、Ｈａ、Ｈｂがそれぞれ独立に1,2,4−オキサジアゾール基、1,3,4−オキサジアゾール基、1,2,4-チオジアゾール基、または1,3,4-チオジアゾール基であることを特徴とする、（２）項に記載のセルロース化合物組成物。
（５）前記セルロース化合物としてセルロースアシレートを含有することを特徴とする（１）〜（４）のいずれか１項に記載のセルロース化合物組成物。
（６）（１）〜（５）のいずれか１項に記載のセルロース化合物組成物からなるセルロース化合物フィルム。 The object of the present invention has been achieved by the following means.
(1) A cellulose compound composition comprising at least one compound containing at least two sites in which an aromatic heterocyclic group and an aromatic hydrocarbon ring group are connected by a single bond.
(2) A cellulose compound composition comprising at least one compound represented by the following general formula (1).

(In the formula, Ha and Hb each independently represent an aromatic heterocyclic group, L represents a single bond or a divalent linking group. R ₁ and R ₂ each represent a substituent, and may be the same or different. A ring may be formed if possible, and n and m each represent an integer of 0 to 5, and may be the same or different.
(3) The cellulose compound composition according to (2), wherein in the compound represented by the general formula (1), Ha and Hb are each independently a 5-membered aromatic heterocyclic group. object.
(4) In the compound represented by the general formula (1), Ha and Hb are each independently 1,2,4-oxadiazole group, 1,3,4-oxadiazole group, 1,2,4 The cellulose compound composition according to item (2), which is a -thiodiazole group or a 1,3,4-thiodiazole group.
(5) Cellulose acylate is contained as said cellulose compound, The cellulose compound composition of any one of (1)-(4) characterized by the above-mentioned.
(6) A cellulose compound film comprising the cellulose compound composition according to any one of (1) to (5).

  The cellulose compound composition of the present invention is useful for forming a film excellent in optical performance that satisfies both individually specified Re value and Rth value. Therefore, the cellulose compound film obtained from this is excellent in optical performance.

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

  The cellulose compound composition of one embodiment of the present invention is a composition containing a cellulose compound, and includes at least one compound containing a site in which an aromatic heterocyclic group and an aromatic hydrocarbon ring group are linked by a single bond. Contains seeds.

As an example of the aromatic heterocycle, a 5-membered or 6-membered aromatic heterocycle is preferable. The aromatic heterocycle may have a substituent, and other heterocycle, aliphatic ring or aromatic ring may be condensed. As examples of the substituent, examples of the substituents R ₁ and R ₂ described later can be applied. The hetero atom of the aromatic heterocyclic ring is preferably a nitrogen atom, an oxygen atom or a sulfur atom.

Examples of the aromatic hydrocarbon ring include a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, and a substituted or unsubstituted naphthyl group. Examples of the substituents R ₁ and R ₂ described later can be applied as the substituent.

  A preferred embodiment of the present invention is a cellulose compound composition containing at least one compound represented by the following general formula (1).

(In the formula, Ha and Hb each independently represent an aromatic heterocyclic group, L represents a single bond or a divalent linking group. R ₁ and R ₂ each represent a substituent, and may be the same or different. A ring may be formed if possible, and n and m each represent an integer of 0 to 5, and may be the same or different.

  In the general formula (1), specific examples of the aromatic heterocyclic group represented by Ha and Hb include, for example, furan, pyrrole, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, Triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benz Examples include oxazole, benzthiazole, benzotriazole, tetrazaindene, pyrrolotriazole, and pyrazolotriazole. More preferably, thiophene, imidazole, pyrazole, pyridine, pyrazine, triazole, triazine, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, isoquinoline, phthalazine, quinoxaline, quinazoline, tetrazole, benzimidazole, benzoxazole, benzthiazole , Benzotriazole, tetrazaindene, pyrrolotriazole, pyrazolotriazole benzimidazole, benzoxazole, benzthiazole, benzotriazole, more preferably a 5-membered aromatic heterocycle, particularly preferably the following H-1 to H -1,2,4-oxadiazole (H-1, H-2), 1,3,4-oxadiazole (H-5), 1,2,4-thiodiazole (H-3, H-4) or 1,3,4-thio An azole (H-6).

In general formula (1), L represents a single bond or a divalent linking group. Preferred as the divalent linking group is a group represented by —NR ⁷ — (R ⁷ represents a hydrogen atom, an alkyl group which may have a substituent or an aryl group), —SO ₂ —, — CO-, substituted or unsubstituted alkylene group, substituted or unsubstituted alkenylene group, alkynylene group, substituted or unsubstituted phenylene group, substituted or unsubstituted biphenylene group, substituted or unsubstituted naphthalene group, -O-, -S-, -SO-, and a group obtained by combining two or more of these divalent groups. More preferably, a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenylene group, an alkynylene group, a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted naphthalene group, Preferably, it is a group selected from the following L-1 to L-20.

  When L is a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenylene group or an alkynylene group, the alkylene group, alkenylene group and alkynylene group preferably have 1 to 15 carbon atoms, and more preferably 1 to 10 carbon atoms. Most preferably, it is 1 to 8. When L is a substituted or unsubstituted alkenylene group, Ha and Hb are mutually in trans and cis positions relative to the alkenylene group, but are not limited here. The trans position is preferred. When L is a substituted or unsubstituted phenylene group, Ha and Hb are preferably in the 1,4-position or 1,3-position of phenylene. When L is a substituted or unsubstituted biphenylene group, it is preferable that Ha and Hb are in a 4,4′-position or 4,3′-position relationship with each other. When L is a substituted or unsubstituted naphthalene group, Ha and Hb are 1,3-position, 1,4-position, 1,5-position, 1,6-position, 1,7-position, 2,4-position, 2, It is preferable to have a 5th, 2nd, 6th, 2, 7th or 2nd, 8th position.

In the general formula (1), R ₁ and R ₂ represent a substituent. The following can be applied as preferred examples.

  Halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), alkyl group (preferably alkyl group having 1 to 30 carbon atoms, such as methyl group, ethyl group, n-propyl group, isopropyl group, t-butyl Group, n-octyl group, 2-ethylhexyl group), cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl group, cyclopentyl group, 4-n-dodecylcyclohexyl group) ), A bicycloalkyl group (preferably a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms. For example, Bicyclo [1,2,2] heptan-2-yl, bicyclo [2,2,2] octane-3-yl), alkenyl (Preferably a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, such as a vinyl group or an allyl group), a cycloalkenyl group (preferably a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, that is, A monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms, for example, 2-cyclopenten-1-yl, 2-cyclohexen-1-yl), bicycloalkenyl group (substituted or unsubstituted); A bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group in which one hydrogen atom of a bicycloalkene having one double bond is removed. , 2,1] hept-2-en-1-yl, bicyclo [2,2,2] oct-2-en-4-yl), an alkynyl group (preferably Or a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms such as an ethynyl group or a propargyl group, an aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms such as a phenyl group, p -Tolyl group, naphthyl group), a heterocyclic group (preferably a monovalent group obtained by removing one hydrogen atom from a 5- or 6-membered substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, More preferably, it is a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms, for example, 2-furyl group, 2-thienyl group, 2-pyrimidinyl group, 2-benzothiazolyl group), cyano group, Hydroxyl group, nitro group, carboxyl group, alkoxy group (preferably a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms such as methoxy group, ethoxy group, iso Propoxy group, t-butoxy group, n-octyloxy group, 2-methoxyethoxy group), aryloxy group (preferably a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, such as phenoxy group, 2- Methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradecanoylaminophenoxy group), silyloxy group (preferably a silyloxy group having 3 to 20 carbon atoms, for example, trimethylsilyloxy group, tert -Butyldimethylsilyloxy group), heterocyclic oxy group (preferably substituted or unsubstituted heterocyclic oxy group having 2 to 30 carbon atoms, 1-phenyltetrazol-5-oxy group, 2-tetrahydropyranyloxy group) An acyloxy group (preferably a formyloxy group, substituted with 2 to 30 carbon atoms) Is an unsubstituted alkylcarbonyloxy group, a substituted or unsubstituted arylcarbonyloxy group having 6 to 30 carbon atoms, such as formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenyl Carbonyloxy group), carbamoyloxy group (preferably a substituted or unsubstituted carbamoyloxy group having 1 to 30 carbon atoms, such as N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy Group, N, N-di-n-octylaminocarbonyloxy group, Nn-octylcarbamoyloxy group), alkoxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms, for example, Methoxycal Nyloxy group, ethoxycarbonyloxy group, tert-butoxycarbonyloxy group, n-octylcarbonyloxy group), aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, for example, , Phenoxycarbonyloxy group, p-methoxyphenoxycarbonyloxy group, pn-hexadecyloxyphenoxycarbonyloxy group), amino group (preferably amino group, substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms) A substituted or unsubstituted anilino group having 6 to 30 carbon atoms, such as amino group, methylamino group, dimethylamino group, anilino group, N-methyl-anilino group, diphenylamino group), acylamino group (preferably formyl Amino group, carbon number 1-30 Substituted or unsubstituted alkylcarbonylamino group, substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms, such as formylamino group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group), amino Carbonylamino group (preferably a substituted or unsubstituted aminocarbonylamino group having 1 to 30 carbon atoms such as carbamoylamino group, N, N-dimethylaminocarbonylamino group, N, N-diethylaminocarbonylamino group, morpholinocarbonyl Amino group), an alkoxycarbonylamino group (preferably a substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms, such as a methoxycarbonylamino group, an ethoxycarbonylamino group, a tert-butoxycarbonylamino group, n Octadecyloxycarbonylamino group, N-methyl-methoxycarbonylamino group), aryloxycarbonylamino group (preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms, such as phenoxycarbonylamino group, p -Chlorophenoxycarbonylamino group, mn-octyloxyphenoxycarbonylamino group), sulfamoylamino group (preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms, such as sulfamoyl Amino group, N, N-dimethylaminosulfonylamino group, Nn-octylaminosulfonylamino group), alkyl and arylsulfonylamino group (preferably substituted or unsubstituted alkylsulfonylamino having 1 to 30 carbon atoms, carbon number) 6-30 Substituted or unsubstituted arylsulfonylamino group, for example, methylsulfonylamino group, butylsulfonylamino group, phenylsulfonylamino group, 2,3,5-trichlorophenylsulfonylamino group, p-methylphenylsulfonylamino group), mercapto group An alkylthio group (preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, such as a methylthio group, an ethylthio group or an n-hexadecylthio group), an arylthio group (preferably a substituted or unsubstituted group having 6 to 30 carbon atoms) Arylthio group such as phenylthio group, p-chlorophenylthio group, m-methoxyphenylthio group), heterocyclic thio group (preferably a substituted or unsubstituted heterocyclic thio group having 2 to 30 carbon atoms such as 2-benzo Thiazolylthio group, 1-phenyltetrazo -5-ylthio group), sulfamoyl group (preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms, such as N-ethylsulfamoyl group, N- (3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group, N-acetylsulfamoyl group, N-benzoylsulfamoyl group, N- (N′phenylcarbamoyl) sulfamoyl group), sulfo group, alkyl and arylsulfinyl group (preferably having carbon number) 1-30 substituted or unsubstituted alkylsulfinyl groups, 6-30 substituted or unsubstituted arylsulfinyl groups such as methylsulfinyl group, ethylsulfinyl group, phenylsulfinyl group, p-methylphenylsulfinyl group), alkyl and An arylsulfonyl group (preferably A substituted or unsubstituted alkylsulfonyl group having 1 to 30 carbon atoms, a substituted or unsubstituted arylsulfonyl group having 6 to 30 carbon atoms (for example, a methylsulfonyl group, an ethylsulfonyl group, a phenylsulfonyl group, a p-methylphenylsulfonyl group), An acyl group (preferably a formyl group, a substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, such as an acetyl group or a pivaloylbenzoyl group), Aryloxycarbonyl group (preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms, such as phenoxycarbonyl group, o-chlorophenoxycarbonyl group, m-nitrophenoxycarbonyl group, p-tert-butylphenoxy Carbonyl group), alkoxycarbonyl A group (preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms such as methoxycarbonyl group, ethoxycarbonyl group, tert-butoxycarbonyl group, n-octadecyloxycarbonyl group), carbamoyl group (preferably carbon A substituted or unsubstituted carbamoyl group having a number of 1 to 30, for example, carbamoyl group, N-methylcarbamoyl group, N, N-dimethylcarbamoyl group, N, N-di-n-octylcarbamoyl group, N- (methylsulfonyl) Carbamoyl group), aryl and heterocyclic azo groups (preferably substituted or unsubstituted arylazo groups having 6 to 30 carbon atoms, substituted or unsubstituted heterocyclic azo groups having 3 to 30 carbon atoms such as phenylazo group, p- Chlorophenylazo group, 5-ethylthio-1,3,4-thiadiazo Ru-2-ylazo group), imide group (preferably N-succinimide group, N-phthalimide group), phosphino group (preferably substituted or unsubstituted phosphino group having 2 to 30 carbon atoms, such as dimethylphosphino Group, diphenylphosphino group, methylphenoxyphosphino group), phosphinyl group (preferably a substituted or unsubstituted phosphinyl group having 2 to 30 carbon atoms, such as phosphinyl group, dioctyloxyphosphinyl group, diethoxyphosphinyl group) Phosphinyloxy group (preferably a substituted or unsubstituted phosphinyloxy group having 2 to 30 carbon atoms, such as diphenoxyphosphinyloxy group, dioctyloxyphosphinyloxy group), phosphinyloxy group, Finylamino group (preferably a substituted or unsubstituted phosphinylamino group having 2 to 30 carbon atoms) Group such as dimethoxyphosphinylamino group, dimethylaminophosphinylamino group), silyl group (preferably a substituted or unsubstituted silyl group having 3 to 30 carbon atoms such as trimethylsilyl group, tert-butyldimethyl) Silyl group, phenyldimethylsilyl group).

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

In general formula (1), n and m represent integers of 0 or more and 5 or less, and may be the same or different. When n or m is 2 or more, a plurality of R ₁ and R ₂ may be the same or different, and may be connected to each other to form a ring if possible.

  Hereinafter, the compound containing at least one kind of the aromatic heterocyclic group and the aromatic hydrocarbon ring group contained in the cellulose compound composition of the present invention with a single bond will be described in detail with specific examples. The present invention is not limited by the following specific examples. Regarding the following compounds, unless otherwise specified, the number in parentheses () indicates the exemplified compound (X).

  In the cellulose compound composition of the present invention, the content of a compound containing a site in which an aromatic heterocyclic group and an aromatic hydrocarbon ring group are connected by a single bond, or a compound represented by the general formula (1) is cellulose. It is preferable that it is 0.1-20 mass% with respect to a compound, More preferably, it is 0.5-16 mass%, More preferably, it is 1-12 mass%, Most preferably, it is 1-8 mass%.

  The compound containing a site in which an aromatic heterocyclic group and an aromatic hydrocarbon ring group are connected by a single bond and the compound represented by the general formula (1) can be used as a retardation control agent for an optical film. It can be suitably used as a retardation control agent for obtaining a film having excellent Re developability by stretching. The compound containing a site in which an aromatic heterocyclic group and an aromatic hydrocarbon ring group are linked by a single bond and the compound represented by the general formula (1) are particularly useful as a retardation control agent for a cellulose compound film. Details, such as a manufacturing method of the film containing these compounds, are mentioned below.

  The synthesis of a compound containing a site in which an aromatic heterocyclic group and an aromatic hydrocarbon ring group are linked by a single bond and a compound represented by the general formula (1) (retardation control agent) can be performed by a known method. For example, the following synthesis examples can be given, but the invention is not limited thereto.

[Synthesis Example 1: Synthesis of Exemplified Compound (1)]
Exemplified compound (1) was synthesized according to the following scheme.

  To a methanol solution of 125.1 g (1.05 mol) of 4-cyanophenol, 139 g (2.1 mol) of a 50% aqueous hydroxylamine solution was added dropwise at room temperature. The temperature of the reaction system was gradually raised to reflux and stirred for 3 hours. After the reaction, the mixture was cooled with ice, and cold water was added to the reaction system to precipitate crystals. The obtained crystals were filtered and dried to obtain 135.8 g (yield 85%) of (1-A).

  (1-A) To 150 ml of 15.2 g (0.1 mol) of N, N-dimethylacetamide was added 8.1 ml (0.1 mol) of pyridine at room temperature, and 25.4 g of 3,4,5-trimethoxybenzoic acid chloride. (0.11 mol) was added in portions. After the addition, the mixture was stirred at room temperature for 30 minutes, and then the reaction temperature was raised to 100 degrees. The mixture was stirred as it was for 3 hours and then allowed to cool. When water was added, crystals precipitated and were filtered off. The crystals separated by filtration were dried, dispersed in ethyl acetate, heated and filtered. Furthermore, 30 g (yield 91%) of (1-B) was obtained by performing the same operation with methanol.

  9.6 ml (55 mmol) of N, N-diisopropylethylamine was added to a solution of 16.4 g (50 mmol) of (1-B) in 250 ml of tetrahydrofuran under ice-cooling, and 10.5 g (55 mmol) of octyl chloroformate in 50 ml of tetrahydrofuran. The solution was added dropwise. The mixture was stirred for 3 hours while raising the temperature to room temperature. By adding methanol to the reaction system, crystals were precipitated and filtered and dried. By dispersing in methanol, heating, and filtration, 20 g of exemplary compound (1) was obtained (yield 84%).

[Synthesis Example 2: Synthesis of Exemplified Compound (13)]
Exemplified compound (13) was synthesized according to the following scheme.

  (13-A) was obtained in the same manner as in Synthesis Example 1. Yield 88%

  (13-A) 8.1 ml (0.1 mol) of pyridine was added to 300 ml of 17 g (0.1 mol) of N, N-dimethylacetamide at room temperature, and 6.7 g (33 mmol) of phthaloyl dichloride was added in portions. After the addition, the mixture was stirred at room temperature for 30 minutes, and then the reaction temperature was raised to 100 degrees. The mixture was stirred as it was for 3 hours and then allowed to cool. When methanol was added, crystals precipitated and were filtered off. The crystals separated by filtration were dried to obtain 36 g (yield 83%) of (13-B).

  To a solution of 8.7 g (20 mmol) of (13-B) in 300 ml of N, N-dimethylacetamide, 8.7 ml (50 mmol) of N, N-diisopropylethylamine was added at room temperature, and further 2-ethylhexyl chloroformate 9 .6 ml (50 mmol) was added dropwise. 14 g of potassium carbonate was added and the mixture was stirred at room temperature for 3 hours. Tetrahydrofuran was added, followed by filtration, and methanol was added to the filtrate to precipitate crystals. After filtration and drying, 13 g of the exemplified compound (13) was obtained by dispersing in methanol, heating, and filtration (yield 88%).

[Cellulose Compound Composition]
The cellulose compound composition of the present invention comprises at least one selected from a compound containing a site in which an aromatic heterocyclic group and an aromatic hydrocarbon ring group are linked by a single bond and a compound represented by the general formula (1). It is a cellulose compound composition containing. In the present invention, the “cellulose compound” is a compound having cellulose as a basic structure, and includes a compound having a cellulose skeleton obtained by introducing a functional group biologically or chemically using cellulose as a raw material. The cellulose compound is preferably a cellulose ester, and more preferably cellulose acylate (such as cellulose triacylate and cellulose acylate propionate). In the present invention, two or more different cellulose compounds may be mixed and used.
Moreover, another embodiment of this invention is a cellulose compound film which consists of this composition. In the present invention, the cellulose compound composition may be a liquid (for example, a cellulose compound solution) or a solid (for example, a cellulose compound film).

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

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

The specific cellulose acylate is a mixed fatty acid ester of cellulose obtained by substituting the hydroxyl group of cellulose with an acetyl group and an acyl group having 3 or more carbon atoms, and the degree of substitution of the cellulose with a hydroxyl group is as follows: It is preferable that the cellulose acylate satisfies the mathematical formulas (4) and (5).
Formula (4): 2.0 ≦ A + B ≦ 3.0
Formula (5): 0 <B
Here, A and B in the formula represent the substitution degree of the acyl group substituted with the hydroxyl group of cellulose, A is the substitution degree of the acetyl group, and B is the substitution degree of the acyl group having 3 or more carbon atoms.

  Glucose units having β-1,4 bonds constituting cellulose have free hydroxyl groups at the 2nd, 3rd and 6th positions. Cellulose acylate is a polymer obtained by esterifying some or all of these hydroxyl groups with acyl groups. The degree of acyl substitution means the proportion of cellulose esterified at each of the 2-position, 3-position and 6-position (100% esterification has a degree of substitution of 1).

[Degree of polymerization of cellulose acylate]
The degree of polymerization of cellulose acylate preferably used in the present invention is 180 to 700 in terms of viscosity average polymerization degree, and in cellulose acetate, 180 to 550 is more preferable, 180 to 400 is more preferable, and 180 to 350 is particularly preferable. . If the degree of polymerization is too high, the viscosity of the cellulose acylate dope solution becomes high, and film production becomes difficult due to casting. If the degree of polymerization is too low, the strength of the produced film will decrease. The average degree of polymerization can be measured by the intrinsic viscosity method of Uda et al. (Kazuo Uda, Hideo Saito, “Journal of Textile Society”, Vol. 18, No. 1, pages 105-120, 1962). This is described in detail in JP-A-9-95538.
Further, the molecular weight distribution of cellulose acylate preferably used in the present invention is evaluated by gel permeation chromatography, and its polydispersity index Mw / Mn (Mw is mass average molecular weight, Mn is number average molecular weight) is small, and molecular weight distribution. Is preferably narrow. The specific value of Mw / Mn is preferably 1.0 to 3.0, more preferably 1.0 to 2.0, and most preferably 1.0 to 1.6. preferable.

  When the low molecular component is removed, the average molecular weight (degree of polymerization) increases, but the viscosity becomes lower than that of normal cellulose acylate, which is useful. Cellulose acylate having a small amount of low molecular components can be obtained by removing low molecular components from cellulose acylate synthesized by a usual method. The removal of the low molecular component can be carried out by washing the cellulose acylate with an appropriate organic solvent. In addition, when manufacturing a cellulose acylate with few low molecular components, it is preferable to adjust the sulfuric acid catalyst amount in an acetylation reaction to 0.5-25 mass parts with respect to 100 mass parts of cellulose. When the amount of the sulfuric acid catalyst is within the above range, cellulose acylate that is preferable in terms of molecular weight distribution (uniform molecular weight distribution) can be synthesized. When used in the production of the cellulose acylate of the present invention, its moisture content is preferably 2% by mass or less, more preferably 1% by mass or less, and particularly 0.7% by mass or less. It is a cellulose acylate having a rate. In general, cellulose acylate contains water and is known to be 2.5 to 5% by mass. In order to obtain the moisture content of the cellulose acylate in the present invention, it is necessary to dry, and the method is not particularly limited as long as the desired moisture content is obtained. These cellulose acylates of the present invention are described in detail on page 7 to page 12 of the raw material cotton and the synthesis method in the Japan Society for Invention and Technology (public technical number 2001-1745, published on March 15, 2001, Japan Society for Invention). It is described in.

  The cellulose acylate of the present invention can be used as a single group or a mixture of two or more different types of cellulose acylates as long as the substituent, substitution degree, polymerization degree, molecular weight distribution and the like are within the above-mentioned ranges.

[Additive to cellulose acylate]
In the cellulose acylate solution of the present invention, various additives other than the compounds used in the present invention in each preparation step (for example, UV inhibitors, plasticizers, deterioration inhibitors, fine particles, optical properties) The additive may be added at any time in the dope preparation process, but the additive is added to the final preparation process of the dope preparation process. You may carry out by adding the process to do.

  They may be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, ultraviolet absorbers of 20 ° C. or lower and 20 ° C. or higher can be mixed and used, and plasticizers can also be mixed and used, for example, as described in JP-A-2001-151901.

[Ultraviolet absorber]
As the ultraviolet absorber, any type can be selected according to the purpose, and a salicylic acid ester-based, benzophenone-based, benzotriazole-based, benzoate-based, cyanoacrylate-based, nickel complex-based absorber or the like is used. Preferred are benzophenone series, benzotriazole series, and salicylic acid ester series.

  Examples of benzophenone ultraviolet absorbers include 2,4-dihydroxybenzophenone, 2-hydroxy-4-acetoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2′-di-hydroxy-4-methoxybenzophenone, 2, 2′-di-hydroxy-4,4′-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4- (2-hydroxy-3- And methacryloxy) propoxybenzophenone.

  As a benzotriazole ultraviolet absorber, 2 (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2 (2′-hydroxy-5′-t-butylphenyl) ) Benzotriazole, 2 (2′-hydroxy-3 ′, 5′-di-t-amylphenyl) benzotriazole, 2 (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) -5 Examples include chlorobenzotriazole, 2 (2′-hydroxy-5′-t-octylphenyl) benzotriazole, and the like.

  Examples of salicylic acid esters include phenyl salicylate, p-octylphenyl salicylate, and p-tert-butylphenyl salicylate.

  Among these exemplified ultraviolet absorbers, in particular, 2-hydroxy-4-methoxybenzophenone, 2,2′-di-hydroxy-4,4′-methoxybenzophenone, 2 (2′-hydroxy-3′-t-butyl- 5'-methylphenyl) -5-chlorobenzotriazole, 2 (2'-hydroxy-5'-t-butylphenyl) benzotriazole, 2 (2'-hydroxy-3 ', 5'-di-t-amylphenyl) ) Benzotriazole, 2 (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) -5-chlorobenzotriazole is particularly preferred.

  As the ultraviolet absorber, it is preferable to use a combination of a plurality of absorbers having different absorption wavelengths because a high blocking effect can be obtained in a wide wavelength range. The ultraviolet absorbent for liquid crystal is preferably one that is excellent in the ability to absorb ultraviolet light having a wavelength of 370 nm or less from the viewpoint of preventing deterioration of the liquid crystal and that has little absorption of visible light having a wavelength of 400 nm or more from the viewpoint of liquid crystal display properties. Particularly preferred ultraviolet absorbers are the benzotriazole compounds, benzophenone compounds, and salicylic acid ester compounds mentioned above. Among these, a benzotriazole-based compound is preferable because unnecessary coloring with respect to the cellulose ester is small.

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

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

  Further, the ultraviolet absorber may be added simultaneously with dissolution of cellulose acylate, or may be added to the dope after dissolution. In particular, a mode in which an ultraviolet absorbent solution is added to the dope immediately before casting using a static mixer or the like is preferable because spectral absorption characteristics can be easily adjusted.

[Deterioration inhibitor]
The deterioration inhibitor can prevent cellulose triacetate and the like from deteriorating and decomposing. Examples of the deterioration preventing agent include butylamine, hindered amine compounds (JP-A-8-325537), guanidine compounds (JP-A-5-271471), benzotriazole-based UV absorbers (JP-A-6-235819), and benzophenone-based compounds. There are compounds such as UV absorbers (JP-A-6-118233).

[Plasticizer]
The plasticizer is preferably a phosphate ester or a carboxylic acid ester. Examples of the phosphate ester plasticizer include triphenyl phosphate (TPP), tricresyl phosphate (TCP), cresyl diphenyl phosphate, octyl diphenyl phosphate, biphenyl diphenyl phosphate (BDP), trioctyl phosphate, tributyl phosphate and the like; Examples of the acid ester plasticizer include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP), diethyl hexyl phthalate (DEHP), O-acetyl citrate. Triethyl acid (OACTE), O-acetyl tributyl citrate (OACTB), acetyl triethyl citrate, acetyl tributyl citrate, oleic acid , Methyl ricinoleate, dibutyl sebacate, triacetin, tributyrin, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, etc. The plasticizer used in the invention is more preferably selected from these exemplified plasticizers. Furthermore, the plasticizer is preferably (di) pentaerythritol esters, glycerol esters, diglycerol esters.

[Peeling accelerator]
Examples of the peeling accelerator include citric acid ethyl esters.
[Infrared absorber]
Furthermore, as an infrared absorber, it describes in Unexamined-Japanese-Patent No. 2001-194522, for example.

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

[Matting agent fine particles]
It is preferable to add fine particles as a matting agent to the cellulose acylate film of the present invention. The fine particles used in the present invention include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, silica Mention may be made of magnesium and calcium phosphates. Fine particles containing silicon are preferable from the viewpoint of low turbidity, and silicon dioxide is particularly preferable. The fine particles of silicon dioxide preferably have a primary average particle diameter of 20 nm or less and an apparent specific gravity of 70 g / liter or more. Those having an average primary particle size as small as 5 to 16 nm are more preferred because they can reduce the haze of the film. The apparent specific gravity is preferably 90 to 200 g / liter or more, and more preferably 100 to 200 g / liter or more. A larger apparent specific gravity is preferable because a high-concentration dispersion can be produced, and haze and aggregates are improved.

  These fine particles usually form secondary particles having an average particle diameter of 0.1 to 3.0 μm, and these fine particles are present as aggregates of primary particles in the film, and 0.1 to 0.1 μm on the film surface. An unevenness of 3.0 μm is formed. The secondary average particle size is preferably from 0.2 μm to 1.5 μm, more preferably from 0.4 μm to 1.2 μm, and most preferably from 0.6 μm to 1.1 μm. The primary and secondary particle sizes were determined by observing the particles in the film with a scanning electron microscope and determining the diameter of a circle circumscribing the particles as the particle size. In addition, 200 particles were observed at different locations, and the average value was taken as the average particle size.

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

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

In order to obtain a cellulose acylate film having particles having a small secondary average particle size in the present invention, several methods are conceivable when preparing a fine particle dispersion. For example, a method of preparing a fine particle dispersion in which a solvent and fine particles are stirred and mixed in advance, adding the fine particle dispersion to a small amount of a separately prepared cellulose acylate solution, stirring and dissolving, and further mixing with the main cellulose acylate dope solution There is. This method is a preferable preparation method in that the dispersibility of the silicon dioxide fine particles is good and the silicon dioxide fine particles are more difficult to reaggregate. In addition, a small amount of cellulose ester is added to the solvent, stirred and dissolved, and then the fine particles are added and dispersed with a disperser to make this fine particle additive solution. There is also a way to do it. The present invention is not limited to these methods, but the concentration of silicon dioxide when the silicon dioxide fine particles are mixed and dispersed with a solvent or the like is preferably 5 to 30% by mass, more preferably 10 to 25% by mass, and 15 to 20%. Mass% is most preferred. A higher dispersion concentration is preferable because the liquid turbidity with respect to the added amount is lowered, and haze and aggregates are improved. The addition amount of the matting agent in the final cellulose acylate dope solution is preferably 0.01 to 1.0 g, more preferably 0.03 to 0.3 g, and 0.08 to 0.16 g per 1 m ^2. Most preferred.

  The solvent used is preferably lower alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol and the like. Although it does not specifically limit as solvents other than a lower alcohol, It is preferable to use the solvent used at the time of film forming of a cellulose ester.

[Rate of compound addition]
In the cellulose acylate film of the present invention, the total amount of compounds having a molecular weight of 3000 or less is preferably 5 to 45% based on the weight of the cellulose acylate. More preferably, it is 10-40%, More preferably, it is 15-30%. As described above, these compounds include compounds that reduce optical anisotropy, wavelength dispersion regulators, ultraviolet inhibitors, plasticizers, deterioration inhibitors, fine particles, release agents, infrared absorbers, etc. Is preferably 3000 or less, and more preferably 2000 or less. When the total amount of these compounds is 5% or less, the properties of the cellulose acylate alone are likely to be produced, and there are problems such that the optical performance and physical strength are likely to fluctuate with changes in temperature and humidity. Moreover, when the total amount of these compounds is 45% or more, problems such as exceeding the limit of compound compatibility in the cellulose acylate film and depositing on the film surface to cause the film to become cloudy (crying out of the film) occur. It becomes easy.

[Organic solvent for cellulose acylate solution]
In the present invention, it is preferable to produce a cellulose acylate film by a solvent cast method, and the film is produced using a solution (dope) in which cellulose acylate is dissolved in an organic solvent. The organic solvent preferably used as the main solvent of the present invention is preferably a solvent selected from esters, ketones, ethers having 3 to 12 carbon atoms, and halogenated hydrocarbons having 1 to 7 carbon atoms. Esters, ketones and ethers may have a cyclic structure. A compound having two or more functional groups of esters, ketones and ethers (that is, —O—, —CO— and —COO—) can also be used as a main solvent. It may have a functional group of In the case of the main solvent having two or more kinds of functional groups, the number of carbon atoms may be within the specified range of the compound having any functional group.

  As described above, chlorine-based halogenated hydrocarbons may be used as the main solvent for the cellulose acylate film of the present invention, and as described in JIII Journal of Technical Disclosure 2001-1745 (pages 12-16), A non-chlorinated solvent may be used as the main solvent, and is not particularly limited to the cellulose acylate film of the present invention.

  In addition, the solvent for the cellulose acylate solution and film of the present invention is disclosed in the following patent documents including the dissolution method, and is a preferred embodiment. For example, JP-A-2000-95876, JP-A-12-95877, JP-A-10-324774, JP-A-8-152514, JP-A-10-330538, JP-A-9-95538, and JP-A-9 JP-A-95557, JP-A-10-235664, JP-A-12-63534, JP-A-11-21379, JP-A-10-182853, JP-A-10-278056, JP-A-10-279702, JP-A-10- No. 323853, JP-A-10-237186, JP-A-11-60807, JP-A-11-152342, JP-A-11-292988, JP-A-11-60752, JP-A-11-60752, and the like. Has been. According to these patent documents, not only the preferred solvent for the cellulose acylate of the present invention but also the physical properties of the solution and the coexisting substances to be coexisted are described, which is a preferred embodiment in the present invention.

[Manufacturing process of cellulose acylate film]
(Dissolution process)
The method for dissolving the cellulose acylate solution (dope) of the present invention is not particularly limited, and it may be performed at room temperature or further by a cooling dissolution method or a high temperature dissolution method, or a combination thereof. Regarding the preparation of the cellulose acylate solution in the present invention, and further the steps of solution concentration and filtration accompanying the dissolution step, the technical report of the Japan Society of Invention (Publication No. 2001-1745, published on March 15, 2001, Japan Society of Invention) The manufacturing process described in detail on pages 22 to 25 is preferably used.

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

(Casting, drying, winding process)
Next, a method for producing a film using the cellulose acylate solution of the present invention will be described. For the method and equipment for producing the cellulose acylate film of the present invention, a solution casting film forming method and a solution casting film forming apparatus conventionally used for producing a cellulose triacetate film are used. The dope (cellulose acylate solution) prepared from the dissolving machine (kettle) is once stored in a storage kettle, and the foam contained in the dope is defoamed for final preparation. The dope is sent from the dope discharge port to the pressure die through a pressure metering gear pump capable of delivering a constant amount of liquid with high accuracy, for example, by the number of rotations, and the dope is run endlessly from the die (slit) of the pressure die. The dry-dried dope film (also referred to as web) is peeled off from the metal support at a peeling point that is uniformly cast on the metal support and substantially rounds the metal support. The both ends of the obtained web are sandwiched between clips, transported by a tenter while holding the width and dried, and then the obtained film is mechanically transported by a roll group of a drying device, dried, and then rolled by a winder Wind up to a predetermined length. The combination of the tenter and the roll group dryer varies depending on the purpose. In the solution casting film forming method used for the functional protective film or the silver halide photographic light-sensitive material which is an optical member for electronic display, which is the main use of the cellulose acylate film of the present invention, the solution casting film forming apparatus In addition, a coating apparatus is often added for surface processing on films such as an undercoat layer, an antistatic layer, an antihalation layer, and a protective layer. These are described in detail on pages 25 to 30 in the Japan Society for Invention and Innovation Technical Report (Public Technical Number 2001-1745, published on March 15, 2001, Japan Society of Inventions). Including), metal support, drying, peeling and the like, and can be preferably used in the present invention.
Moreover, 10-120 micrometers is preferable, as for the thickness of a cellulose acylate film, 20-100 micrometers is more preferable, and 30-90 micrometers is more preferable.

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

  The film is stretched at room temperature or under heating conditions. The heating temperature is preferably not higher than the glass transition temperature of the film. The stretching of the film may be uniaxial stretching only in the longitudinal or lateral direction, or may be simultaneous or sequential biaxial stretching. Usually, the stretching is performed at 1 to 200%, but the stretching is preferably performed at 1 to 100%, particularly preferably 1 to 50%.

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

  The film thickness of the cellulose acylate film preferably used in the present invention obtained after drying varies depending on the purpose of use, and is usually preferably in the range of 5 to 500 μm, more preferably in the range of 20 to 300 μm, particularly 30 to 30 μm. A range of 150 μm is preferred. Moreover, it is preferable that it is 40-110 micrometers for optical use, especially for VA liquid crystal display devices. The film thickness may be adjusted by adjusting the solid content concentration contained in the dope, the slit gap of the die base, the extrusion pressure from the die, the metal support speed, and the like so as to obtain a desired thickness.

  The width of the cellulose acylate film obtained as described above is preferably 0.5 to 3 m, more preferably 0.6 to 2.5 m, and still more preferably 0.8 to 2.2 m. The length is preferably 100 to 10,000 m per roll, more preferably 500 to 7000 m, and still more preferably 1000 to 6000 m. When winding, it is preferable to give knurling to at least one end, the knurling width is preferably 3 mm to 50 mm, more preferably 5 mm to 30 mm, and the height is preferably 0.5 to 500 μm, more preferably 1 to 200 μm. is there. This may be a single push or a double push.

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

[Optical properties of cellulose acylate film]
In the present specification, Reλ and Rthλ represent in-plane retardation and retardation in the thickness direction at the wavelength λ, respectively. Reλ is measured by making light having a wavelength of λ nm incident in the normal direction of the film in “KOBRA 21ADH” (manufactured by Oji Scientific Instruments). Rthλ is light having a wavelength of λ nm from the direction inclined by + 40 ° with respect to the normal direction of the film, with Reλ and the in-plane slow axis (determined by “KOBRA 21ADH”) as the tilt axis (rotation axis). The retardation value measured and the retardation measured by injecting light of wavelength λ nm from the direction inclined by −40 ° with respect to the normal direction of the film, with the in-plane slow axis as the tilt axis (rotation axis) “KOBRA 21ADH” is calculated based on the retardation value measured in a total of three directions, the assumed value of the average refractive index, and the input film thickness value.
Here, as the assumed value of the average refractive index, values in the polymer handbook (JOHN WILEY & SONS, INC) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). The KOBRA 21ADH calculates nx, ny, and nz by inputting the assumed value of the average refractive index and the film thickness.

It is preferable that the Reλ retardation value and the Rthλ retardation value satisfy the following formulas (2) and (3), respectively, in order to widen the viewing angle of a liquid crystal display device, particularly a VA mode liquid crystal display device. In particular, a cellulose acylate film is preferable when used for a protective film on the liquid crystal cell side of the polarizing plate.
Formula (2): 0 nm ≦ Re ₅₉₀ ≦ 200 nm
Formula (3): 0 nm ≦ Rth ₅₉₀ ≦ 400 nm
[In the formula, Re ₅₉₀ and Rth ₅₉₀ are values at a wavelength λ = 590 nm (unit: nm). ]

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

[Water permeability of film]
The moisture permeability of the cellulose acylate film used in the optical compensation sheet of the present invention is measured under conditions of a temperature of 60 ° C. and a humidity of 95% RH (relative humidity) based on JIS standard JISZ0208, and converted to a film thickness of 80 μm. It is preferable that it is 400-2000 g / m < ² > * 24h. More preferably 500~1800g / m ² · 24h, and particularly preferably 600~1600g / m ² · 24h. If it exceeds 2000 g / m ² · 24 h, the tendency of the absolute value of the humidity dependence of the Re value and Rth value of the film to exceed 0.5 nm /% RH becomes strong. Also, when an optically anisotropic film is formed by laminating an optically anisotropic layer on the cellulose acylate film of the present invention, the absolute value of the humidity dependence of the Re value and Rth value tends to exceed 0.5 nm /% RH. It becomes strong and is not preferable. When this optical compensation sheet or polarizing plate is incorporated in a liquid crystal display device, it causes a change in color and a decrease in viewing angle. In addition, when the moisture permeability of the cellulose acylate film is less than 400 g / m ² · 24 h, when the polarizing plate is prepared by being attached to both surfaces of the polarizing film, the cellulose acylate film prevents the drying of the adhesive, and adhesion Cause a defect.
If the film thickness of the cellulose acylate film is thick, the moisture permeability becomes small, and if the film thickness is thin, the moisture permeability becomes large. Therefore, it is necessary to convert the sample of any film thickness to a standard of 80 μm. Conversion of the film thickness is obtained as (water vapor permeability in terms of 80 μm = measured water vapor permeability × measured film thickness μm / 80 μm).
The measurement method for moisture permeability is “Polymer Physical Properties II” (Polymer Experiment Course 4, Kyoritsu Shuppan), pages 285 to 294: Measurement of vapor permeation (mass method, thermometer method, vapor pressure method, adsorption amount method) The cellulose acylate film sample 70 mmφ of the present invention was conditioned at 25 ° C., 90% RH, 60 ° C., and 95% RH for 24 hours, respectively, and a moisture permeation test apparatus (KK- 709007, trade name, Toyo Seiki Co., Ltd.) according to JIS Z-0208, calculate the amount of moisture per unit area (g / m ² ), and obtain moisture permeability = weight after humidity adjustment-weight before humidity adjustment. .

[Residual solvent amount of film]
It is preferable to dry on the conditions that the amount of residual solvents with respect to the cellulose acylate film of the present invention is in the range of 0.01 to 1.5% by mass. More preferably, it is 0.01-1.0 mass%. Curling can be suppressed by setting the residual solvent amount of the transparent support used in the present invention to 1.5% or less. More preferably, it is 1.0% or less. This is presumably because the main effect factor is that the free volume is reduced by reducing the amount of residual solvent at the time of film formation by the solvent casting method described above.

[Hygroscopic expansion coefficient of film]
The hygroscopic expansion coefficient of the cellulose acylate film of the present invention is preferably 30 × 10 ⁻⁵ /% RH or less. The hygroscopic expansion coefficient is preferably 15 × 10 ⁻⁵ /% RH or less, and more preferably 10 × 10 ⁻⁵ /% RH or less. Further, the hygroscopic expansion coefficient is preferably small, but usually a value of 1.0 × 10 ⁻⁵ /% RH or more. The hygroscopic expansion coefficient indicates the amount of change in the length of the sample when the relative humidity is changed at a constant temperature. By adjusting this hygroscopic expansion coefficient, when the cellulose acylate film of the present invention is used as an optical compensation film support, the optical transmittance of the frame-shaped transmittance is increased while maintaining the optical compensation function of the optical compensation film. Leakage can be prevented.

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

[Alkaline saponification]
The alkali saponification treatment is preferably carried out by a method in which the cellulose acylate film is directly immersed in a saponification solution tank or a method in which the saponification solution is applied to the cellulose acylate film. Examples of the coating method include a dip coating method, a curtain coating method, an extrusion coating method, a bar coating method, and an E-type coating method. The solvent of the alkali saponification coating solution has good wettability in order to apply the saponification solution to the cellulose acylate film, and the surface of the cellulose acylate film surface is not formed by the saponification solution solvent without forming irregularities. It is preferred to select a solvent that remains good. Specifically, an alcohol solvent is preferable, and isopropyl alcohol is particularly preferable. An aqueous solution of a surfactant can also be used as a solvent. The alkali of the alkali saponification coating solution is preferably an alkali that dissolves in the above solvent, and more preferably KOH or NaOH. The pH of the saponification coating solution is preferably 10 or more, and more preferably 12 or more. The reaction conditions during alkali saponification are preferably 1 second to 5 minutes at room temperature, more preferably 5 seconds to 5 minutes, and particularly preferably 20 seconds to 3 minutes. After the alkali saponification reaction, it is preferable to wash the surface on which the saponification solution is applied with water or with an acid and then with water.

[Functional layer]
The cellulose acylate film of the present invention is applied to optical uses and photographic light-sensitive materials as its uses. In particular, the optical application is preferably a liquid crystal display device, and the liquid crystal display device has a liquid crystal cell in which liquid crystal is supported between two electrode substrates, two polarizing elements disposed on both sides thereof, and the liquid crystal It is more preferable that at least one optical compensation sheet is disposed between the cell and the polarizing element. As these liquid crystal display devices, TN, IPS, FLC, AFLC, OCB, STN, ECB, VA and HAN are preferable.
In that case, when using the cellulose acylate film of this invention for the above-mentioned optical use, providing various functional layers is implemented. These are, for example, an antistatic layer, a cured resin layer (transparent hard coat layer), an antireflection layer, an easy adhesion layer, an antiglare layer, an optical compensation layer, an alignment layer, a liquid crystal layer, and the like. Examples of these functional layers and materials for which the cellulose acylate film of the present invention can be used include surfactants, slip agents, matting agents, antistatic layers, hard coat layers, and the like. No. 2001-1745, published on March 15, 2001, Invention Association), pages 32 to 45, and can be preferably used in the present invention.

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

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

(General liquid crystal display device configuration)
When the cellulose acylate film is used as an optical compensation film, the transmission axis of the polarizing element and the slow axis of the optical compensation film made of the cellulose acylate film may be arranged at any angle. The liquid crystal display device includes a liquid crystal cell having a liquid crystal supported between two electrode substrates, two polarizing elements disposed on both sides thereof, and at least one sheet between the liquid crystal cell and the polarizing element. The optical compensation film is arranged.
The liquid crystal layer of the liquid crystal cell is usually formed by sealing liquid crystal in a space formed by sandwiching a spacer between two substrates. The transparent electrode layer is formed on the substrate as a transparent film containing a conductive substance. The liquid crystal cell may further be provided with a gas barrier layer, a hard coat layer, or an undercoat layer (undercoat layer) (used for adhesion of the transparent electrode layer). These layers are usually provided on the substrate. The substrate of the liquid crystal cell generally has a thickness of 50 μm to 2 mm.

(Types of liquid crystal display devices)
The cellulose acylate film of the present invention can be used for liquid crystal cells in various display modes. TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), AFLC (Anti-Ferroly Liquid Liquid Crystal), OCB (Optically Charged STP). Various display modes such as ECB (Electrically Controlled Birefringence) and HAN (Hybrid Aligned Nematic) have been proposed. In addition, a display mode in which the above display mode is oriented and divided has been proposed. The cellulose acylate film of the present invention is effective in any display mode liquid crystal display device. Further, it is effective in any of a transmissive type, a reflective type, and a transflective liquid crystal display device.

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

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

(VA type liquid crystal display device)
The cellulose acylate film of the present invention is particularly advantageously used as a support for an optical compensation sheet of a VA liquid crystal display device having a VA mode liquid crystal cell. It is preferable that the Re retardation value of the optical compensation sheet used in the VA liquid crystal display device is 0 to 150 nm and the Rth retardation value is 70 to 400 nm. The Re retardation value is more preferably 20 to 70 nm. When two optically anisotropic polymer films are used in the VA liquid crystal display device, the Rth retardation value of the film is preferably 70 to 250 nm. When one optically anisotropic polymer film is used for the VA liquid crystal display device, the Rth retardation value of the film is preferably 150 to 400 nm. The VA-type liquid crystal display device may be an alignment-divided system as described in, for example, JP-A-10-123576.

(IPS liquid crystal display device and ECB liquid crystal display device)
The cellulose acylate film of the present invention is particularly advantageously used as a support for an optical compensation sheet of an IPS liquid crystal display device and an ECB liquid crystal display device having IPS mode and ECB mode liquid crystal cells, or as a protective film for a polarizing plate. It is done. In these modes, the liquid crystal material is aligned substantially in parallel during black display, and black is displayed by aligning liquid crystal molecules parallel to the substrate surface in the absence of voltage. In these embodiments, the polarizing plate using the cellulose acylate film of the present invention contributes to improving the color tone, widening the viewing angle, and improving the contrast. In this aspect, the cellulose acylate film of the present invention is used for the protective film (the protective film on the cell side) disposed between the liquid crystal cell and the polarizing plate among the protective films of the polarizing plates above and below the liquid crystal cell. It is preferable to use the polarizing plate at least on one side. More preferably, an optically anisotropic layer is disposed between the protective film of the polarizing plate and the liquid crystal cell, and the retardation value of the disposed optically anisotropic layer is twice the value of Δn · d of the liquid crystal layer. It is preferable to set as follows.

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

(Reflective liquid crystal display)
The cellulose acylate film of the present invention is also advantageously used as an optical compensation sheet for TN-type, STN-type, HAN-type, and GH (Guest-Host) type reflective liquid crystal display devices. These display modes have been well known since ancient times. The TN type reflection type liquid crystal display device is described in JP-A-10-123478, WO98848320, and Japanese Patent No. 3022477. The optical compensation sheet used in the reflective liquid crystal display device is described in WO00-65384.

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

(Hard coat film, antiglare film, antireflection film)
The cellulose acylate film of the present invention can be preferably applied to a hard coat film, an antiglare film and an antireflection film. For the purpose of improving the visibility of flat panel displays such as LCD, PDP, CRT, EL, etc., any or all of a hard coat layer, an antiglare layer and an antireflection layer are provided on one or both sides of the cellulose acylate film of the present invention. Can be granted. Preferred embodiments of such an antiglare film and antireflection film are described in detail in pages 54 to 57 of the Japan Institute of Invention and Technology (Publication No. 2001-1745, published on March 15, 2001, Japan Society of Invention). The cellulose acylate film of the present invention can be preferably used.

(Photo film support)
Furthermore, the cellulose acylate film of the present invention can be applied as a support for silver halide photographic light-sensitive materials, and various materials, formulations and processing methods described in the patent literature can be applied. Regarding these techniques, JP-A-2000-105445 describes in detail the color negative, and the cellulose acylate film of the present invention is preferably used. Further, application as a support for a color reversal silver halide photographic light-sensitive material is also preferable, and various materials, formulations and processing methods described in JP-A No. 11-282119 can be applied.

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

  In order to control the Re value and the Rth value of the cellulose compound film of the present invention within preferable ranges, compounds containing a moiety in which the aromatic heterocyclic group and the aromatic hydrocarbon ring group used are connected by a single bond, It is preferable to appropriately adjust the type and amount of the compound represented by formula (1) (retardation control agent) and the stretching ratio of the film. In particular, in the present invention, a retardation control agent capable of achieving a desired Rth value is selected, and the addition amount of the retardation control agent and the stretching ratio of the film are appropriately set so that a desired Re value is obtained. By doing so, a cellulose compound film having desired Re value and Rth value can be obtained.

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

Example 1
Preparation of Cellulose Acetate Film Each component of the following cellulose acetate solution composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution.

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

In another mixing tank, as the retardation control agent (additive 1 shown in Table 1 ⁾ ), the exemplified compound (13), (16), (27), (28), or the following comparative compound and 87 masses of methylene chloride. And 13 parts by mass of methanol were added and stirred while heating to prepare each retardation control (rising) agent solution.
A dope was prepared by mixing 36 parts by mass of a retardation control (raising) agent solution with 474 parts by mass of the cellulose acetate solution and stirring sufficiently. Each retardation controlling agent solution was prepared so that the amount of the retardation controlling agent was added in the amount shown in Table 1 with respect to 100 parts by weight of cellulose acetate.

  The obtained dope was cast using a band casting machine. A film having a residual solvent amount of 15% by mass was laterally stretched at a stretch ratio of 15% using a tenter under the conditions of 170 ° C. to produce a cellulose acetate film (thickness: 92 μm). About the produced cellulose acetate film (optical compensation sheet), the Re retardation value and the Rth retardation value at a wavelength of 590 nm were measured as follows. The results are shown in Table 1. In Table 1, No. 1 is a cellulose acetate film produced in the same manner except that no retardation control agent solution is added.

<Measurement of Re and Rth>
Re was measured with KOBRA 21ADH (manufactured by Oji Scientific Instruments Co., Ltd.) by making light having a wavelength of 590 nm incident in the normal direction of the film. Rth was measured by making light having a wavelength of 590 nm incident from the direction inclined by + 40 ° with respect to the normal direction of the film with the slow axis in the plane (determined by KOBRA 21ADH) as the tilt axis (rotation axis). The retardation value and the retardation value measured by making light with a wavelength of 590 nm incident from a direction inclined by −40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis (rotation axis). It was calculated based on the retardation value measured in the direction, the assumed value of the average refractive index, and the input film thickness value.

Comparative compound (compound described in Patent Document 2)

  As can be seen from the results in Table 1, when the exemplified compound of the present invention is added in the same weight part as the comparative compound, Re is expressed at the same level or higher, and the expression of Rth is small.

In addition, the film containing no comparative compound, the film containing 2 parts by mass of the comparative compound, and the film containing 5 parts by mass of the comparative compound are all
Rth = Re × 3.6 + 43 (Formula 1)
Meet.
Since the film containing the comparative compound expresses Re by stretching and Rth does not change so much, by adding the comparative compound,
Rth ≧ Re × 3.6 + 43 (Formula 2)
It can be seen that a film satisfying the optical characteristics of the region can be produced.
On the other hand, by adding the compound of the present invention, a novel cellulose compound film having a greater Re developability (that is, a region of Rth <Re × 3.6 + 43) that could not be realized with the film added with the comparative compound can be produced. I understand.

  As can be seen from the results in Table 1, by adding the compound of the present invention, a novel cellulose compound having optical characteristics in a region with higher Re expression that could not be realized by a known discotic compound (comparative compound) Film production became possible.

As described above, the cellulose compound film of the present invention can be suitably used as an optical film for liquid crystal display devices, particularly as an optical compensation sheet.

Claims (6)

  A cellulose compound composition comprising at least one compound containing at least two sites where an aromatic heterocyclic group and an aromatic hydrocarbon ring group are linked by a single bond. A cellulose compound composition comprising at least one compound represented by the following general formula (1).

(In the formula, Ha and Hb each independently represent an aromatic heterocyclic group, L represents a single bond or a divalent linking group. R ₁ and R ₂ each represent a substituent, and may be the same or different. A ring may be formed if possible, and n and m each represent an integer of 0 to 5, and may be the same or different.   The cellulose compound composition according to claim 2, wherein in the compound represented by the general formula (1), Ha and Hb are each independently a 5-membered aromatic heterocyclic group.   In the compound represented by the general formula (1), Ha and Hb are each independently 1,2,4-oxadiazole group, 1,3,4-oxadiazole group, 1,2,4-thiodiazole group. Or a cellulose compound composition according to claim 2, which is a 1,3,4-thiodiazole group.   Cellulose acylate is contained as said cellulose compound, The cellulose compound composition of any one of Claims 1-4 characterized by the above-mentioned. The cellulose compound film which consists of a cellulose compound composition of any one of Claims 1-5.