JP2006195157A - Optical compensation film, polarizing plate and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical material such as an optical compensation film and a polarizing plate which is excellent in a viewing angle characteristic and hardly causes the degradation of a display quality when changing environmental humidity, and to provide a liquid crystal display device using them. <P>SOLUTION: The optical compensation film comprises a cyclic polyolefine film satisfying the following relation (I) and a cellulose acylate film satisfying the following relations (II), (III). Otherwise, the liquid crystal display device includes the cyclic polyolefine film satisfying the following relation (I) and the cellulose acylate film satisfying the following relations (II), (III), at least one sheet at a time. (I): 35≤Re<SB>(630)</SB>≤350 and 70≤Rth<SB>(630)</SB>≤400, (II): 0≤Re<SB>(630)</SB>≤10 and ¾Rth<SB>(630)</SB>¾≤25, (III): ¾Re<SB>(400)</SB>-Re<SB>(700)</SB>¾≤10 and ¾Rth<SB>(400)</SB>-Rth<SB>(700)</SB>¾≤35. Therein, Re<SB>(λ)</SB>denotes a front retardation value (unit: nm) at wavelength λnm and Rth<SB>(λ)</SB>denotes a retardation value (unit: nm) of the film thickness direction at wavelength λnm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical compensation film, a polarizing plate, and a liquid crystal display device. In particular, the present invention relates to a cyclic polyolefin optical biaxial retardation film used for them and a cellulose acylate film useful for a liquid crystal display device, and further relates to an optical material using the same, an optical material such as a polarizing plate, and a liquid crystal display device.

A polarizing plate is usually produced by laminating a film mainly composed of cellulose triacetate as a protective film on both sides of a polarizing film in which iodine or a dichroic dye is oriented and adsorbed on polyvinyl alcohol. Cellulose triacetate has characteristics such as toughness, flame retardancy, and high optical isotropy (low retardation value), and is widely used as the protective film for polarizing plates described above. The liquid crystal display device is composed of a polarizing plate and a liquid crystal cell. At present, in a TN mode TFT liquid crystal display device which is the mainstream of liquid crystal display devices, as described in Patent Document 1, by inserting an optical compensation sheet (retardation film) between a polarizing plate and a liquid crystal cell, A liquid crystal display device with high display quality has been realized.
Cyclic polyolefin film is attracting attention as a film that can improve anisotropy, hygroscopicity and moisture permeability because of its high optical isotropy due to the design of molecular structure. Display films are being developed. However, fluctuations in the optical characteristics (retardation and direction of the optical axis) in the width direction and the length direction are problematic in hot melt film formation. In general, it is known that a film having an excellent surface shape can be obtained by solution casting. In order to produce optical anisotropy, the optical anisotropy can be freely controlled by transverse stretching with a tenter, longitudinal stretching between rolls, a combination thereof, etc. during solution casting. These are cellulose acylate films. It is much more expressive than alone (in the absence of functional additives).

  On the other hand, in recent liquid crystal display devices, improvement in viewing angle characteristics has been strongly demanded, and optical transparent films such as a protective film for a polarizer and a support for an optical compensation film are more optical. It is required to be isotropic. In order to be optically isotropic, it is important that the retardation value represented by the product of birefringence and thickness of the optical film is small. In particular, in order to improve display from an oblique direction, it is necessary to reduce not only the retardation (Re) in the front direction but also the retardation (Rth) in the film thickness direction. Specifically, when the optical properties of the optical transparent film are evaluated, the Re measured from the front of the film is small, and it is required that the Re does not change even if the angle is changed.

  So far, there has been a cellulose acylate film with a small Re on the front, but it was difficult to produce a cellulose acylate film with a small Re change with angle, that is, a small Rth.

  As a solution to this problem, it is strongly desired to improve the cellulose acylate film which is excellent in the bonding property to PVA by further reducing the optical anisotropy. Specifically, it is an optically isotropic optically transparent film in which Re on the front surface of the cellulose acylate film is substantially zero and the change in retardation angle is small, that is, Rth is also substantially zero.

  In the production of a cellulose acylate film, a compound called a plasticizer is generally added to improve the film forming performance. As types of plasticizers, phosphate triesters such as triphenyl phosphate and biphenyl diphenyl phosphate, phthalates, and the like are disclosed (for example, see Non-Patent Document 1). Among these plasticizers, those having the effect of reducing the optical anisotropy of the cellulose acylate film are known. For example, specific fatty acid esters are disclosed (for example, see Patent Document 2). ). However, the effect of reducing the optical anisotropy of cellulose acylate films using these conventionally known compounds is not sufficient.

Also, recent liquid crystal display devices are required to improve display color. Therefore, an optical transparent film such as a protective film for a polarizer or a support for an optical compensation film not only reduces Re and Rth in the visible region of a wavelength of 400 to 800 nm, but also changes Re and Rth depending on the wavelength, that is, wavelength dispersion. It needs to be small.
Further, there is a demand for a liquid crystal display device having a high-quality image that does not change display performance such as color, contrast, and viewing angle dependency even with environmental changes such as humidity.

JP-A-8-50206 JP 2001-247717 A "Plastic Materials Course Volume 17, Fiber-Based Resin", Nikkan Kogyo Shimbun, (Showa 45), p. 121

SUMMARY OF THE INVENTION A first object of the present invention is to provide a liquid crystal display device with little display characteristic fluctuation with respect to environmental temperature and humidity changes. A second object of the present invention is a cellulose having a small optical anisotropy (Re, Rth) and substantially optical isotropy, and further having a small wavelength dispersion of the optical anisotropy (Re, Rth). It is to provide an acylate film. The third object of the present invention is optical including a cyclic polyolefin film capable of developing optical anisotropy and a cellulose acylate film having small optical anisotropy (Re, Rth) and substantially optical isotropy. It is to provide a compensation film, a polarizing plate, and a liquid crystal display device.
The fourth object of the present invention is to show that optical materials such as an optical compensation film and a polarizing plate produced from a cellulose acylate film having small optical anisotropy and small wavelength dispersion have excellent viewing angle characteristics. And to provide a liquid crystal display device using them.

By using a cellulose acylate film having a small optical anisotropy and a small wavelength dispersion as a protective film for a polarizing plate, the optical properties of the polarizing plate can be improved. When used as a support for an optical compensation film, the optical performance of the optical compensation film itself can be brought out. By using these polarizing plates and optical compensation films in a liquid crystal display device, the contrast can be improved and the color can be improved.
As an optical compensation layer, a cyclic polyolefin film whose optical anisotropy can be freely controlled is used, and a polarizing plate protective film as a support thereof is not a commercially available cellulose acylate film such as Fujitac. By using the cellulose acylate film having small optical anisotropy (Re, Rth) and substantially optical isotropy, and further having small wavelength dispersion of optical anisotropy (Re, Rth). The function separation was made clearer.
In other words, a film with high optical anisotropy is a cyclic polyolefin film, which makes it difficult for optical properties to change with respect to environmental temperature and humidity changes. The cellulose acylate film is used which suppresses the properties and has high adhesion and adhesiveness to the polyvinyl alcohol of the polarizer and, in addition, has a smaller change in display performance than plain tack with respect to changes in environmental humidity. By using these combinations in a liquid crystal display device, the contrast can be improved and the color can be improved.
That is, the above object has been achieved by the following means.
(1)
An optical compensation film comprising a cyclic polyolefin film satisfying the following formula (I) and a cellulose acylate film satisfying the following formulas (II) and (III).
(I) 35 ≦ Re ₍₆₃₀₎ ≦ 350 and 70 ≦ Rth ₍₆₃₀₎ ≦ 400
(II) 0 ≦ Re ₍₆₃₀₎ ≦ 10 and | Rth ₍₆₃₀₎ | ≦ 25
(III) | Re ₍₄₀₀₎ −Re ₍₇₀₀₎ | ≦ 10 and | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ | ≦ 35
[Re ₍ λ ₎ represents the front retardation value (unit: nm) at the wavelength λnm, and Rth ₍ λ ₎ represents the retardation value (unit: nm) in the film thickness direction at the wavelength λnm. ]
(2)
At least one sheet of a cyclic polyolefin film satisfying the following formula (I) and a cellulose acylate film satisfying the following formulas (II) and (III) are included between two polarizing films of the liquid crystal display device. Liquid crystal display device.
(I) 35 ≦ Re ₍₆₃₀₎ ≦ 350 and 70 ≦ Rth ₍₆₃₀₎ ≦ 400
(II) 0 ≦ Re ₍₆₃₀₎ ≦ 10 and | Rth ₍₆₃₀₎ | ≦ 25
(III) | Re ₍₄₀₀₎ −Re ₍₇₀₀₎ | ≦ 10 and | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ | ≦ 35
[Re ₍ λ ₎ represents the front retardation value (unit: nm) at the wavelength λnm, and Rth ₍ λ ₎ represents the retardation value (unit: nm) in the film thickness direction at the wavelength λnm. ]
(3)
The cyclic polyolefin film is composed of a copolymer comprising at least one repeating unit represented by the general formula (A) and at least one cyclic repeating unit represented by the general formula (B). The optical compensation film according to (1) or the liquid crystal display device according to (2).

In the formula, m represents an integer of 0 to 4. R ^{1 to} R ⁴ are a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, X ^{1 to} X ² , and Y ^{1 to} Y ² are a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, and a halogen atom. substituted hydrocarbon group having 1 to 10 carbon _{atoms, - (CH 2) n COOR} 11, - (CH 2) n OOCR 12, - (CH 2) n NCO, - (CH 2) n NO 2, - ( CH ₂ ) _n CN, — (CH ₂ ) _n CONR ¹³ R ¹⁴ , — (CH ₂ ) _n NR ¹³ R ¹⁴ , — (CH ₂ ) _n OCOZ, — (CH ₂ ) _n OZ, — (CH ₂ ) _n W, (—CO) ₂ O, (—CO) ₂ NR ¹⁵ composed of X ¹ and Y ¹ or X ² and Y ² are shown. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ are hydrocarbon groups having 1 to 20 carbon atoms, Z is a hydrocarbon group or a hydrocarbon group substituted with halogen, and W is SiR ¹⁶ _p D _{3− p} (R ¹⁶ is a hydrocarbon group having 1 to 10 carbon atoms, D is a halogen atom —OCOR ¹⁶ or —OR ¹⁶ , p is an integer of 0 to 3), and n is an integer of 0 to 10.
(4)
The cyclic polyolefin film is a polymer comprising one type of cyclic repeating unit represented by general formulas (B) and (C), or at least two types of cyclic repeating represented by general formulas (B) and (C). The optical compensation film according to (1) or the liquid crystal display device according to (2), wherein the optical compensation film is a copolymer comprising units.

In the formula, m represents an integer of 0 to 4. R ^{3 to} R ⁶ are hydrogen atoms or hydrocarbon groups having 1 to 10 carbon atoms, X ^{2 to} X ³ and Y ^{2 to} Y ³ are hydrogen atoms, hydrocarbon groups having 1 to 10 carbon atoms, halogen atoms, and halogen atoms. substituted hydrocarbon group having 1 to 10 carbon _{atoms, - (CH 2) n COOR} 11, - (CH 2) n OOCR 12, - (CH 2) n NCO, - (CH 2) n NO 2, - ( CH ₂ ) _n CN, — (CH ₂ ) _n CONR ¹³ R ¹⁴ , — (CH ₂ ) _n NR ¹³ R ¹⁴ , — (CH ₂ ) _n OCOZ, — (CH ₂ ) _n OZ, — (CH ₂ ) _n W, (—CO) ₂ O, (—CO) ₂ NR ¹⁵ composed of X ² and Y ² or X ³ and Y ³ are shown. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ are hydrocarbon groups having 1 to 20 carbon atoms, Z is a hydrocarbon group or a hydrocarbon group substituted with halogen, and W is SiR ¹⁶ _p D _{3− p} (R ¹⁶ is a hydrocarbon group having 1 to 10 carbon atoms, D is a halogen atom —OCOR ¹⁶ or —OR ¹⁶ , p is an integer of 0 to 3), and n is an integer of 0 to 10.
(5)
The cyclic polyolefin film is cast on an endless metal support with an organic solvent solution containing 10% to 35% by weight of the polymer or copolymer, dried, and then peeled off from the metal support. The optical compensation film according to (3) or (4), wherein the film is formed by stretching in at least one of the width direction and the length direction, further drying and winding up, or The liquid crystal display device according to (3) or (4).
(6)
The cellulose acylate film contains at least one compound that reduces the retardation Rth in the film thickness direction within the range satisfying the following formulas (IV) and (V): (1), (3) -The optical compensation film in any one of (5), or the liquid crystal display device in any one of (2)-(5).
(IV) (Rth (A) −Rth (0)) / A ≦ −1.0
(V) 0.01 ≦ A ≦ 30
here,
Rth (A): Rth (nm) of a film containing A% of a compound that lowers Rth
Rth (0): Rth (nm) of a film not containing a compound that lowers Rth
A: Mass (%) of the compound when the mass of the film raw material polymer is 100
It is.
(7)
The optical compensation film according to any one of (1) and (3) to (6), wherein the cellulose acylate film is a cellulose acylate having an acyl substitution degree of 2.85 to 3.00, Or the liquid crystal display device in any one of (2)-(6).
(8)
The cellulose acylate film contains at least one compound that lowers | Rth ₍₄₀₀₎ -Rth ₍₇₀₀₎ | in an amount of 0.01 to 30% by mass based on the solid content of cellulose acylate (1 ), The optical compensation film according to any one of (3) to (7), or the liquid crystal display device according to any one of (2) to (7).
(9)
The film thickness of the said cellulose acylate film is 10-120 micrometers, The optical compensation film in any one of (1), (3)-(8), or (2)-(8) The liquid crystal display device according to any one of the above.
(10)
(1) A polarizing plate having at least one optical compensation film according to any one of (3) to (9) as a protective film for a polarizer.
(11)
The polarizing plate according to (10), wherein at least one layer of a hard coat layer, an antiglare layer and an antireflection layer is provided on the surface.
(12)
A liquid crystal display device comprising the optical compensation film according to any one of (1) and (3) to (9) and the polarizing plate according to (10) or (11).
(13)
A VA or IPS liquid crystal display device comprising the optical compensation film according to any one of (1) and (3) to (9) and the polarizing plate according to (10) or (11) .

  By using a cellulose acylate film and a cyclic polyolefin film with small optical anisotropy and small wavelength dispersion of Re and Rth, the viewing angle characteristics are excellent and the display quality is not lowered when the environmental humidity is changed. An optical material such as an optical compensation film and a polarizing plate, and a liquid crystal display device using these materials can be provided.

  Hereinafter, the present invention will be described in detail.

1. First, the cyclic polyolefin film of the present invention will be described.
The cyclic polyolefin film of the present invention is a cyclic polyolefin film that satisfies the following formula (I).
(I) 35 ≦ Re ₍₆₃₀₎ ≦ 350 and 70 ≦ Rth ₍₆₃₀₎ ≦ 400
The above formula (I) is: (I) 35 ≦ Re ₍₆₃₀₎ ≦ 300 and 100 ≦ Rth ₍₆₃₀₎ ≦ 350
More preferably,
(I) 35 ≦ Re ₍₆₃₀₎ ≦ 250 and 100 ≦ Rth ₍₆₃₀₎ ≦ 300
More preferably.
The cyclic polyolefin film of the present invention can be produced as follows.

(Cyclic polyolefin)
Examples of thermoplastic polymer resins having a cyclic olefin structure include (1) a norbornene polymer, (2) a polymer of a monocyclic olefin, (3) a polymer of a cyclic conjugated diene, and (4) a vinyl fat. Examples thereof include cyclic hydrocarbon polymers and hydrides of (1) to (4). Among these, from the viewpoints of optical properties, heat resistance, mechanical strength, and the like, norbornene-based polymers and hydrides thereof, vinyl alicyclic hydrocarbon polymers and hydrides thereof are preferable.

  Preferred polymers for the present invention are a copolymer cyclic polyolefin containing at least one type of repeating unit represented by the following general formula (A) and a cyclic repeating unit represented by the general formula (B), and a general formula (B) Alternatively, it is a ring-opening (co) polymer or an addition (co) polymer containing at least one cyclic repeating unit represented by (C).

In the formula, m represents an integer of 0 to 4. R ^{1 to} R ⁶ are hydrogen atoms or hydrocarbon groups having 1 to 10 carbon atoms, X ^{1 to} X ³ and Y ^{1 to} Y ³ are hydrogen atoms, hydrocarbon groups having 1 to 10 carbon atoms, halogen atoms, and halogen atoms. substituted hydrocarbon group having 1 to 10 carbon _{atoms, - (CH 2) n COOR} 11, - (CH 2) n OOCR 12, - (CH 2) n NCO, - (CH 2) n NO 2, - ( CH ₂ ) _n CN, — (CH ₂ ) _n CONR ¹³ R ¹⁴ , — (CH ₂ ) _n NR ¹³ R ¹⁴ , — (CH ₂ ) _n OCOZ, — (CH ₂ ) _n OZ, — (CH ₂ ) _n W, (—CO) ₂ O, (—CO) ₂ NR ¹⁵ composed of X ¹ and Y ^1, X ² and Y ^2, or X ³ and Y ³ are shown. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ are hydrocarbon groups having 1 to 20 carbon atoms, Z is a hydrocarbon group or a hydrocarbon group substituted with halogen, and W is SiR ¹⁶ _p D _{3− p} (R ¹⁶ is a hydrocarbon group having 1 to 10 carbon atoms, D is a halogen atom —OCOR ¹⁶ or —OR ¹⁶ , p is an integer of 0 to 3), and n is an integer of 0 to 10.

Norbornene polymer hydrides are disclosed in JP-A-1-240517, JP-A-7-196736, JP-A-60-26024 or JP-A-62-19801, and pamphlet of International Publication No. 04/070463. As disclosed in U.S. Pat. No. 6,037,049, it is produced by addition polymerization of a polycyclic unsaturated compound or by metathesis ring-opening polymerization followed by hydrogenation. In the norbornene-based polymer used in the present invention, R ^{9 to} R ¹² are preferably a hydrogen atom or —CH ₃ , X ³ , X ⁴ , Y ³ and Y ⁴ are preferably a hydrogen atom, Cl, —COOCH ₃ , The group is appropriately selected. This norbornene resin is marketed by JSR Corporation under the trade name Arton G or Arton F, and from Zeon Corporation, Zeonor ZF14, ZF16, Zeonex 250 or Zeonex 280. These are commercially available under the trade name and can be used.

  Vinyl alicyclic hydrocarbon polymers are disclosed in JP-A-10-87752 and JP-A-2001-272534. A compound having a structure in which a monocyclic cycloalkyl group, an alkyl-substituted cycloalkyl group, a cycloalkenyl group, or an alkyl-substituted cycloalkenyl group is bonded to a vinyl group or an α-alkyl-substituted vinyl group, a vinyl group, or an α-alkyl-substituted vinyl A cyclic compound such as a compound to which an aromatic hydrocarbon substituent is bonded, and ethylene, propylene, butene; conjugated dienes such as butadiene and isoprene; nonconjugated dienes such as ethylidene norbornene; acrylonitrile, acrylic acid, methacrylic acid Polymerization methods such as radical polymerization, coordination anionic polymerization, and cationic polymerization can be applied to linear diene compounds such as maleic anhydride, acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate, and vinyl chloride. This vinyl alicyclic hydrocarbon polymer is marketed by Mitsui Chemicals, Inc. under the name of Apel, for example, APL8008T (Tg70 ° C), APL6013T (Tg125 ° C) or APL6015T (Tg145) having different glass transition temperatures (Tg). Grade).

(Additive)
In the cyclic polyolefin solution of the present invention, various additives (for example, deterioration inhibitors, UV inhibitors, retardation (optical anisotropy) modifiers, fine particles, peeling accelerators, red, etc.) according to the application in each preparation step. External absorbents, etc.) can be added and they can be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, mixing of an ultraviolet absorbing material at 20 ° C. or lower and 20 ° C. or higher, and a mixture of deterioration preventing agents are also possible. Furthermore, infrared absorbing dyes are described, for example, in JP-A No. 2001-194522. Moreover, the addition time may be added at any time in the dope preparation step, but may be added by adding an additive to the final preparation step of the dope preparation step. Furthermore, the amount of each material added is not particularly limited as long as the function is manifested. Moreover, when a cyclic polyolefin film is formed from a multilayer, the kind and addition amount of the additive of each layer may differ.

(Deterioration inhibitor)
For the cyclic polyolefin film of the present invention, known deterioration (oxidation) inhibitors such as 2,6-di-t-butyl, 4-methylphenol, 4,4′-thiobis- (6-t-butyl-3-) are used. Methylphenol), 1,1′-bis (4-hydroxyphenyl) cyclohexane, 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 2,5-di-tert-butylhydroquinone, pentaerythrityl -Phenolic or hydroquinone antioxidants such as tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate can be added. Further, tris (4-methoxy-3,5-diphenyl) phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2,6-di-t It is preferable to use a phosphorus-based antioxidant such as -butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite. The added amount of the antioxidant is 0.05 to 5.0 parts by mass with respect to 100 parts by mass of the cyclic polyolefin.

(UV absorber)
For the cyclic polyolefin film of the present invention, an ultraviolet absorber is preferably used from the viewpoint of preventing deterioration of a polarizing plate or liquid crystal. As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having a small absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties. Specific examples of UV absorbers preferably used in the present invention include, for example, hindered phenol compounds, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds Etc. Examples of hindered phenol compounds include 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]. N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert) -Butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate and the like. Examples of benzotriazole compounds include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5- Triazine, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-tert-butyl-4- Hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole, (2 (2′-hydroxy-3 ′, 5′-di-tert-amylphenyl) -5 -Chlorobenzotriazole, 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and the like. The addition amount of these ultraviolet light inhibitors is preferably 1 ppm to 1.0%, more preferably 10 to 1000 ppm in terms of mass ratio with respect to cellulose acylate.

(Matting agent)
In the present invention, when the produced cyclic polyolefin film is handled, it is preferable to add fine particles in order to prevent scratches or deterioration of transportability. Preferred examples of the matting agent include inorganic compounds such as silicon-containing compounds, silicon dioxide, titanium oxide, zinc oxide, aluminum oxide, barium oxide, zirconium oxide, strongtium oxide, antimony oxide, tin oxide, and tin oxide / antimony. , Calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate are preferred, more preferably inorganic compounds and zirconium oxide containing silicon, Since the turbidity of the film can be reduced, silicon dioxide is particularly preferably used. As the silicon dioxide fine particles, for example, commercially available products having trade names such as Aerosil R972, R974, R812, 200, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.) can be used. As the fine particles of zirconium oxide, for example, those commercially available under trade names such as Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) can be used.
The primary average particle diameter of these fine particles is preferably 0.001 to 20 μm, more preferably 0.001 to 10 μm, and still more preferably 0.002 to 1 μm, from the viewpoint of keeping haze low. Especially preferably, it is 0.005-0.5 micrometer. The measurement of the primary average particle diameter of the fine particles is obtained by the average particle diameter of the particles with a transmission electron microscope. The purchased fine particles are often agglomerated and are preferably dispersed by a known method before use. The secondary particle diameter is preferably 0.2 to 1.5 μm by dispersion, and more preferably 0.3 to 1.0 μm. The amount of fine particles added is preferably 0.01 to 0.3 parts by weight, more preferably 0.05 to 0.2 parts by weight, and most preferably 0.08 to 0.12 parts by weight with respect to 100 parts by weight of the cyclic polyolefin. .

Next, the organic solvent in which the cyclic polyolefin of the present invention is dissolved will be described.
(Chlorine solvent)
In preparing the cyclic polyolefin solution of the present invention, a chlorinated organic solvent is preferably used as the main solvent. In the present invention, the kind of the chlorinated organic solvent is not particularly limited as long as the object can be achieved as long as the cyclic polyolefin can be dissolved, cast, and formed into a film. These chlorinated organic solvents are preferably dichloromethane and chloroform. Particularly preferred is dichloromethane. In addition, there is no particular problem in mixing an organic solvent other than the chlorinated organic solvent. In that case, it is necessary to use at least 50% by mass of dichloromethane. The non-chlorine organic solvent used in combination with the chlorinated organic solvent in the present invention is described below. That is, as a preferable non-chlorine organic solvent, a solvent selected from esters, ketones, ethers, alcohols, hydrocarbons and the like having 3 to 12 carbon atoms is preferable. Esters, ketones, ethers and alcohols 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 solvent. For example, other functional groups such as alcoholic hydroxyl groups can be used. You may have group simultaneously. In the case of a solvent having two or more types of functional groups, the number of carbon atoms may be within the specified range of the compound having any functional group. Examples of esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate. Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and methylcyclohexanone. Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole. Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol.

The alcohol used in combination with the chlorinated organic solvent may be linear, branched or cyclic, and among them, saturated aliphatic hydrocarbon is preferable. The hydroxyl group of the alcohol may be any of primary to tertiary. Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, 1-pentanol, 2-methyl-2-butanol and cyclohexanol. As the alcohol, fluorine-based alcohol is also used. Examples thereof include 2-fluoroethanol, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol and the like. Furthermore, the hydrocarbon may be linear, branched or cyclic. Either aromatic hydrocarbons or aliphatic hydrocarbons can be used. The aliphatic hydrocarbon may be saturated or unsaturated. Examples of hydrocarbons include cyclohexane, hexane, benzene, toluene and xylene.
Although the following can be mentioned as a combination of the chlorinated organic solvent which is a preferable main solvent of this invention, It is not limited to these.

Dichloromethane / methanol / ethanol / butanol (80/8/5/2, parts by mass),
Dichloromethane / methanol / butanol / cyclohexane (75/10/5/5/5, parts by mass),
Dichloromethane / acetone / methyl ethyl ketone / ethanol / isopropanol (75/10/10/5/7, parts by mass),
Dichloromethane / methyl acetate / butanol (80/10/10, parts by mass),
Dichloromethane / 1, 3 dioxolane / methanol / ethanol (70/20/5/5, parts by mass),
Dichloromethane / dioxane / acetone / methanol / ethanol (60/20/10/5/5, parts by mass),
Dichloromethane / acetone / ethyl acetate / ethanol / butanol / hexane (65/10/10/5/5/5, parts by mass),
Dichloromethane / methyl acetoacetate / methanol / ethanol (65/20/10/5, parts by mass),
・ Dichloromethane (100, parts by mass)
・ Dichloromethane / ethanol (92/8, parts by mass)
Etc.

By devising the solvent composition, the peel resistance value when peeling the dry film from the metal support greatly changes. By adding a non-solvent having polarity to the chlorinated organic solvent as the main solvent, the peel resistance is remarkably lowered. Examples of the polar solvent having a particularly great effect of reducing the peeling resistance include alcohols having 1 to 4 carbon atoms, monocarboxylic acids having 1 to 5 carbon atoms, divalent or higher carboxylic acids, and half esters thereof. Of these, alcohols are most preferred because of their excellent volatility. The preferable ratio of the chlorine-based main solvent and the polar non-solvent is 70 to 98 parts by mass for the chlorine-based solvent and 2 to 30 parts by mass for the polar non-solvent. A more desirable ratio is 78 to 95 parts by mass of the chlorinated solvent and 5 to 22 parts by mass of the polar non-solvent.
Preferred solvent combinations with low peel resistance include the following, but are not limited to these.
Dichloromethane / methanol / ethanol / butanol (83/10/5/2, parts by mass),
Dichloromethane / methyl acetate / ethanol (80/10/10, parts by mass),
Dichloromethane / methanol / isopropanol (78/15/7, parts by mass),
・ Dichloromethane / methanol (87/13, parts by mass)

(Non-chlorine solvent)
Next, the non-chlorine organic solvent that is preferably used in preparing the cyclic polyolefin solution of the present invention will be described. In the present invention, the non-chlorine organic solvent is not particularly limited as long as the object can be achieved as long as the cyclic polyolefin can be dissolved, cast, and formed into a film. The non-chlorine organic solvent used in the present invention is preferably a solvent selected from chain hydrocarbons having 3 to 12 carbon atoms, cyclic hydrocarbons, aromatic hydrocarbons, esters, ketones and ethers. 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, such as an alcoholic hydroxyl group. 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. Examples of chain hydrocarbons having 3 to 12 carbon atoms include hexane, octane, isooctane, decane, and the like. Examples of cyclic hydrocarbons having 3 to 12 carbon atoms include hexane and derivatives thereof. Examples of the aromatic hydrocarbon having 3 to 12 carbon atoms include benzene, toluene, xylene and the like. Examples of esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate. Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and methylcyclohexanone. Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole. Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol.

(Dope preparation)
Next, with respect to the preparation of the cyclic polyolefin solution (dope) of the present invention, the dissolution method is not particularly limited, and may be room temperature, or a cooling dissolution method or a high temperature dissolution method, or a combination thereof. With respect to these, the same technique as the cellulose acylate film is applicable, and the Institute of Technology Publication No. 2001-1745 (issued on March 15, 2001, which describes in detail the method for dissolving cellulose acylate, The 25th and later pages of the “Invention Association” are helpful. In addition, when it melt | dissolves at high temperature, it is the case where it is more than the boiling point of the organic solvent to be used, and in that case, it uses in a pressurized state.

  The viscosity of the cyclic polyolefin solution of the present invention is preferably in the range of 1 to 500 Pa · s at 25 ° C. More preferably, it is the range of 5-200 Pa.s. The viscosity was measured as follows. 1 mL of the sample solution was measured with a rheometer (CLS 500) using a Steel Cone having a diameter of 4 cm / 2 ° (both manufactured by TA Instruments). Measurement was started after the sample solution was kept warm at the measurement start temperature until the liquid temperature became constant.

  The cyclic polyolefin solution is characterized in that a high-concentration dope can be obtained, and a cyclic polyolefin solution having a high concentration and excellent stability can be obtained without depending on the means of concentration. Furthermore, in order to make it easy to melt | dissolve, after making it melt | dissolve at a low density | concentration, you may concentrate using a concentration means. The concentration method is not particularly limited. For example, the low-concentration solution is guided between the cylindrical body and the rotation trajectory of the outer periphery of the rotating blade rotating in the circumferential direction, and the temperature between the solution and the solution. A method of obtaining a high-concentration solution while evaporating the solvent by giving a difference (for example, JP-A-4-259511), a heated low-concentration solution is blown into the container from the nozzle, and the solution is applied from the nozzle to the inner wall of the container In which the solvent is flash evaporated and the solvent vapor is withdrawn from the container and the concentrated solution is withdrawn from the bottom of the container (eg, US Pat. No. 2,541,012, US Pat. No. 2,858,229, US Pat. No. 4,414,341, US Pat. No. 4,504,355, etc.).

Prior to casting, it is preferable to filter off foreign matters such as undissolved matter, dust, and impurities using a suitable filter medium such as a wire mesh or flannel. For the filtration of the cyclic polyolefin solution, a filter having an absolute filtration accuracy of 0.1 to 100 μm is used, and a filter having an absolute filtration accuracy of 0.5 to 25 μm is preferably used. The thickness of the filter is preferably 0.1 to 10 mm, and more preferably 0.2 to 2 mm. In that case, the filtration pressure is preferably 1.6 MPa or less, more preferably 1.3 MPa or less, further 1.0 MPa or less, and particularly preferably 0.6 MPa or less. As the filter medium, conventionally known materials such as glass fibers, cellulose fibers, filter paper, and fluororesins such as tetrafluoroethylene resin can be preferably used, and ceramics and metals are also preferably used.
The viscosity of the cyclic polyolefin solution just before film formation may be in a range that can be cast during film formation. s is more preferable, and 30 Pa · s to 200 Pa · s is still more preferable. In addition, although the temperature at this time will not be specifically limited if it is the temperature at the time of the casting, Preferably it is -5-70 degreeC, More preferably, it is -5-35 degreeC.

(Film formation)
A method for producing a film using a cyclic polyolefin solution will be described. As the method and equipment for producing the cyclic polyolefin film of the present invention, the same solution casting film forming method and solution casting film forming apparatus as those conventionally used for cellulose triacetate film production are used. The dope (cyclic polyolefin solution) prepared from the dissolving machine (kettle) is temporarily 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. 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. Both ends of the obtained web are sandwiched between clips, transported with a tenter and dried, then transported with a roll group of a drying device, dried, and wound up to a predetermined length with a winder. 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 for electronic displays, in addition to the solution casting film forming apparatus, surface processing on films such as an undercoat layer, an antistatic layer, an antihalation layer, a protective layer, etc. Therefore, a coating device is often added. Although each manufacturing process is described briefly below, it is not limited to these.

First, the prepared cyclic polyolefin solution (dope) is cast on a metal drum or metal band (belt) when a cyclic polyolefin film is produced by the solvent cast method, and the solvent is evaporated to form a film. To do. It is preferable to adjust the concentration of the dope before casting so that the polymer amount is 10 to 35% by mass. The surface of the drum or band is preferably finished in a mirror state. The dope is preferably cast on a drum or band having a surface temperature of 30 ° C. or lower, and particularly preferably a metal support temperature of −10 to 20 ° C.
Further, JP-A Nos. 2000-301555, 2000-301558, 7-032391, JP-A-3-193316, JP-A-5-086212, JP-A-62-237113, JP-A-2-276607. The cellulose acylate film forming techniques described in JP-A-55-014201, JP-A-2-111511, and JP-A-2-208650 can be applied in the present invention.

(Multilayer casting)
The cyclic polyolefin solution may be cast as a single layer liquid on a smooth band or drum as a metal support, or a plurality of cyclic polyolefin liquids of two or more layers may be cast. When casting a plurality of cyclic polyolefin solutions, a film may be produced while casting and laminating a solution containing a cyclic polyolefin from a plurality of casting ports provided at intervals in the traveling direction of the metal support. For example, the methods described in, for example, JP-A-61-158414, JP-A-1-122419, and JP-A-11-198285 can be applied.
Further, it may be formed into a film by casting a cyclic polyolefin solution from two casting ports. For example, JP-B-60-27562, JP-A-61-94724, JP-A-61-947245, This can be carried out by the methods described in JP-A Nos. 61-104813, 61-158413, and 6-134933. Also, a cyclic polyolefin film casting method described in Japanese Patent Application Laid-Open No. 56-162617 wraps a flow of a high-viscosity cyclic polyolefin solution with a low-viscosity cyclic polyolefin solution and simultaneously extrudes the high- and low-viscosity cyclic polyolefin solution. Good. Furthermore, it is also a preferred embodiment that the outer solution described in JP-A-61-94724 and JP-A-61-94725 contains a larger amount of an alcohol component which is a poor solvent than the inner solution. Alternatively, the film is formed by peeling the film formed on the metal support using the first casting port and performing the second casting on the side in contact with the metal support surface using the two casting ports. For example, it is a method described in Japanese Patent Publication No. 44-20235. The cyclic polyolefin solution to be cast may be the same solution or different cyclic polyolefin solutions, and is not particularly limited. In order to give a function to a plurality of cyclic polyolefin layers, a cyclic polyolefin solution corresponding to the function may be extruded from each casting port. Further, the cyclic polyolefin solution may be cast simultaneously with other functional layers (for example, an adhesive layer, a dye layer, an antistatic layer, an antihalation layer, a UV absorption layer, and a polarizing layer).

In the case of a single layer liquid, it is necessary to extrude a high-concentration and high-viscosity cyclic polyolefin solution in order to obtain the required film thickness. In this case, the cyclic polyolefin solution is not stable and solids are generated. It tends to cause problems due to failure or poor flatness. As a solution to this problem, by casting a plurality of cyclic polyolefin solutions from the casting port, it is possible to extrude a highly viscous solution onto a metal support at the same time. Not only can this be achieved, but a reduction in drying load can be achieved by using a concentrated cyclic polyolefin solution, and the production speed of the film can be increased.
In the case of co-casting, the inner and outer thicknesses are not particularly limited, but the outer side is preferably 1 to 50% of the total film thickness, more preferably 2 to 30%. Here, in the case of co-casting with three or more layers, the total thickness of the layer in contact with the metal support and the layer in contact with the air side is defined as the outer thickness. In the case of co-casting, a cyclic polyolefin film having a laminated structure can also be produced by co-casting cyclic polyolefin solutions having different additive concentrations such as the above-mentioned deterioration inhibitor, ultraviolet absorber, matting agent and the like. For example, a cyclic polyolefin film having a structure of skin layer / core layer / skin layer can be produced. For example, the matting agent can be contained in the skin layer in a large amount or only in the skin layer. The deterioration inhibitor and the ultraviolet absorber can be contained in the core layer more than the skin layer, and may be contained only in the core layer. It is also possible to change the type of deterioration inhibitor and ultraviolet absorber between the core layer and the skin layer. For example, the skin layer may contain a low volatility deterioration inhibitor and / or an ultraviolet absorber so that the core layer is plastic. It is also possible to add an excellent plasticizer or an ultraviolet absorber excellent in ultraviolet absorption. Moreover, it is also a preferable aspect that a peeling accelerator is contained only in the skin layer on the metal support side. Moreover, in order to cool a metal support body by a cooling drum method and to gelatinize a solution, it is also preferable to add more alcohol which is a poor solvent to a skin layer than a core layer. The Tg of the skin layer and the core layer may be different, and the Tg of the core layer is preferably lower than the Tg of the skin layer. Further, the viscosity of the solution containing the cyclic polyolefin at the time of casting may be different between the skin layer and the core layer, and the viscosity of the skin layer is preferably smaller than the viscosity of the core layer. It may be smaller than the viscosity.

(Casting)
As a solution casting method, a method in which the prepared dope is uniformly extruded from a pressure die onto a metal support, and a method using a doctor blade in which the dope once cast on the metal support is adjusted with a blade is used. Alternatively, there is a method using a reverse roll coater that adjusts with a reverse rotating roll, and a method using a pressure die is preferable. The pressure die includes a coat hanger type and a T die type, and any of them can be preferably used. In addition to the methods listed here, it can be carried out by various methods of casting a cellulose triacetate solution known in the art, and by setting each condition in consideration of differences in the boiling point of the solvent used, etc. The same effects as those described in the above publication can be obtained. The endlessly running metal support used for producing the cyclic polyolefin film of the present invention includes a drum whose surface is mirror-finished by chrome plating and a stainless steel belt (which may be called a band) whose surface is mirror-finished by surface polishing. Good) is used. The pressure die used for the production of the cyclic polyolefin film of the present invention may be one or two or more installed above the metal support. Preferably 1 or 2 groups. When two or more units are installed, the amount of dope to be cast may be divided into various ratios for each die, or the dope may be fed to the dies from each of a plurality of precision quantitative gear pumps. The temperature of the cyclic polyolefin solution used for casting is preferably −10 to 55 ° C., more preferably 25 to 50 ° C. In that case, all of the steps may be the same or may be different at different points in the step. If they are different, it may be a desired temperature just before casting.

(Dry)
The dope drying on the metal support involved in the production of the cyclic polyolefin film is generally performed by applying hot air from the surface side of the metal support (drum or belt), that is, the surface of the web on the metal support, drum Alternatively, a method in which hot air is applied from the back of the belt, a liquid whose temperature is controlled is brought into contact with the back of the belt or drum opposite the dope casting surface, and the drum or belt is heated by heat transfer to control the surface temperature. Although there is a heat method, the back surface liquid heat transfer method is preferable. The surface temperature of the metal support before casting may be any number as long as it is not higher than the boiling point of the solvent used for the dope. However, in order to promote drying and to lose fluidity on the metal support, the temperature should be set to 1 to 10 degrees lower than the boiling point of the lowest boiling solvent used. Is preferred. This is not the case when the cast dope is cooled and peeled off without drying.

(Extension process)
In the cyclic polyolefin film of the present invention, the retardation can be adjusted by a stretching treatment. Furthermore, there is also a method of positively stretching in the width direction. -48271, and the like. This stretches the produced film in order to increase the in-plane retardation value of the cyclic polyolefin film.
The film is stretched at room temperature or under heating conditions. The heating temperature is preferably ± 50 ° C. of the glass transition temperature of the film. More preferably, it is ± 45 ° C., more preferably ± 40 ° C. The stretching of the film may be uniaxial stretching only in the longitudinal or lateral direction, or may be simultaneous or sequential biaxial stretching. Stretching is performed by 0.5 to 200%. Stretching of 0.5 to 100% is preferable, and stretching of 0.5 to 50% is particularly preferable. The birefringence of the optical film is preferably such that the refractive index in the width direction is larger than the refractive index in the length direction. Therefore, it is preferable to stretch more in the width direction. In addition, the stretching process may be performed in the middle of the film forming process, or the raw film that has been formed and wound may be stretched. In the former case, the stretching may be performed in a state including the residual solvent amount, and the stretching can be preferably performed when the residual solvent amount is 1 to 50%.

The thickness of the finished (after drying) cyclic polyolefin film of the present invention varies depending on the purpose of use, but is usually in the range of 5 to 500 μm, preferably in the range of 30 to 150 μm, particularly for liquid crystal display devices, 40 to 110 μm. It is preferable that
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 cyclic polyolefin 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, knurling is preferably applied to at least one end, the width is 3 mm to 50 mm, more preferably 5 m to 30 mm, and the height is 0.5 to 500 μm, and more preferably 1 to 200 μm. This may be a single push or a double push. The variation in the Re value over the entire width is preferably ± 5 nm, and more preferably ± 3 nm. Further, the variation of the Rth value is preferably ± 10 nm, and more preferably ± 5 nm. Further, 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. In order to maintain transparency, the haze is preferably 0.01 to 2%. In order to reduce the haze, the added fine matting agent is sufficiently dispersed to reduce the number of aggregated particles, or the matting agent is used only in the skin layer in order to reduce the addition amount.

The cyclic polyolefin film has a great advantage that the moisture permeability and the equilibrium moisture content are small as compared with the cellulose acylate film conventionally used for polarizing plates. The moisture permeability is preferably 1000 g or less per square meter at 60 ° C. and 95% RH for 24 hours. More preferably, it is 400 g or less. A preferable equilibrium water content is 2.0% or less at 25 ° C. and 80% RH. More preferably, it is 1.0% or less. Additives such as UV absorbers and retardation enhancers are volatile and degradable, and optical properties change when a mass change or dimensional change of the film occurs. Therefore, it is preferable that the mass change amount of the film after aging for 48 hours at 80 ° C. 90% RH is 5% or less. Similarly, the dimensional change after 24 hours at 60 ° C. 95% RH is preferably 5% or less. Even if there is a small dimensional change or mass change, if the photoelastic coefficient of the film is small, the amount of change in optical characteristics is small. Accordingly, the photoelastic coefficient of the film is preferably 30 × 10 ⁻¹³ cm ² / dyne or less, and more preferably 15 × 10 ⁻¹³ cm ² / dyne or less.

(Adhesion)
When the cyclic polyolefin film of the present invention is bonded to a polarizing film such as PVA, a protective film for a polarizing film, a retardation film, etc., the bonding technique described in the item of polarizing plate described later, the method described in the surface treatment, and the like. Applicable. Moreover, it can also stick together using an adhesive material etc. In addition, an appropriate method is appropriately used depending on the type of material (hydrophilicity or hydrophobicity) on the other side to be bonded.

(Polarizer)
The polarizing plate is composed of a polarizer and two transparent protective films disposed on both sides thereof. As one protective film, the cyclic polyolefin film of the present invention can be used. The other protective film may be a normal cellulose acetate film. Examples of the polarizer include an iodine polarizer, a dye polarizer using a dichroic dye, and a polyene polarizer. The iodine polarizer and the dye polarizer are generally produced using a polyvinyl alcohol film. When the cyclic polyolefin film of the present invention is used as a polarizing plate protective film, the film is subjected to a surface treatment as described later, and then the film-treated surface and a polarizer are bonded together using an adhesive. Examples of the adhesive used include polyvinyl alcohol adhesives such as polyvinyl alcohol and polyvinyl butyral, vinyl latexes such as butyl acrylate, and gelatin. The polarizing plate is composed of a polarizer and a protective film that protects both surfaces of the polarizer, and further comprises 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 contact bonding layer bonded to a liquid crystal plate, and is used for the surface side which bonds a polarizing plate to a liquid crystal plate.

The method of laminating the cyclic polyolefin film of the present invention to the polarizer is preferably performed so that the transmission axis of the polarizer coincides with the slow axis of the cyclic polyolefin film of the present invention. In addition, when the polarizing plate produced under polarizing plate crossed Nicols was evaluated, the orthogonality accuracy between the slow axis of the cyclic polyolefin film of the present invention and the absorption axis of the polarizer (axis orthogonal to the transmission axis) was 1 °. When it was larger, it was found that the polarization degree performance under the polarizing plate crossed Nicols was lowered and light leakage occurred. In this case, when combined with a liquid crystal cell, sufficient black level and contrast cannot be obtained. Therefore, the deviation between the direction of the main refractive index nx of the cyclic polyolefin film of the present invention and the direction of the transmission axis of the polarizing plate is preferably within 1 °, preferably within 0.5 °.
UV3100PC (manufactured by Shimadzu Corporation) was used for the single plate transmittance TT, the parallel transmittance PT, and the orthogonal transmittance CT of the polarizing plate. In the measurement, measurement was performed in the range of 380 nm to 780 nm, and the average value of 10 measurements was used for each of the single plate, parallel, and orthogonal transmittance. The polarizing plate durability test was performed as follows in two types of forms in which (1) only the polarizing plate and (2) the polarizing plate were bonded to glass via an adhesive. For the measurement of only the polarizing plate, two orthogonal and identical ones were prepared and measured so that the optical compensation film was sandwiched between the two polarizers. Two samples (approx. 5 cm × 5 cm) are prepared by attaching a polarizing plate on glass so that the optical compensation film is on the glass side. In the single plate transmittance measurement, the film side of this sample was set facing the light source. Two samples were measured respectively, and the average value was defined as the transmittance of the single plate. The preferable range of polarization performance is 40.5 ≦ TT ≦ 45, 32 ≦ PT ≦ 39.5, and CT ≦ 1.5 in the order of single plate transmittance TT, parallel transmittance PT, and orthogonal transmittance CT, respectively. More preferable ranges are 41.0 ≦ TT ≦ 44.5, 34 ≦ PT ≦ 39.0, and CT ≦ 1.3. In the polarizing plate durability test, the amount of change is preferably smaller.

(Surface treatment of cyclic polyolefin film)
In the present invention, the surface of the cyclic polyolefin protective film is surface-treated in order to improve the adhesion between the polarizer and the protective film. As for the surface treatment, any method that can improve the adhesiveness may be used. Preferred surface treatments include, for example, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, and flame treatment. The glow discharge treatment here refers to so-called low temperature plasma that occurs under low pressure gas. In the present invention, plasma treatment under atmospheric pressure is also preferable. The details of the glow discharge treatment are described in US Pat. No. 3,462,335, US Pat. No. 3,761,299, US Pat. No. 4,072,769, and British Patent No. 891469. A method described in Japanese Patent Publication No. 59-556430 is also used in which the gas composition generated in the vessel is made only when the polyester support itself undergoes a discharge treatment after the discharge starts. In addition, the method described in Japanese Patent Publication No. 60-16614, in which the surface temperature of the film is set to 80 ° C. or higher and 180 ° C. or lower when the vacuum glow discharge treatment is performed, can also be applied.

The vacuum degree during the glow discharge treatment is preferably 0.5 to 3000 Pa, more preferably 2 to 300 Pa. The voltage is preferably between 500 and 5000V, more preferably between 500 and 3000V. The discharge frequency to be used is from DC to several thousand MHz, more preferably 50 Hz to 20 MHz, and further preferably 1 KHz to 1 MHz. The discharge treatment intensity is preferably 0.01 KV · A · min / m ^{2 to 5} KV · A · min / m ² , more preferably 0.15 KV · A · min / m ^{2 to 1} KV · A · min / m ² . is there.

In the present invention, it is also preferable to perform an ultraviolet irradiation method as the surface treatment. For example, it can be carried out by the processing methods described in JP-B 43-2603, JP-B 43-2604, and JP-B 45-3828. The mercury lamp is a high-pressure mercury lamp made of a quartz tube and preferably has an ultraviolet wavelength of 180 to 380 nm. As for the method of ultraviolet irradiation, a high pressure mercury lamp with a dominant wavelength of 365 nm can be used as long as the surface temperature of the protective film rises to around 150 ° C. in terms of the performance of the support. When low-temperature treatment is required, a low-pressure mercury lamp having a dominant wavelength of 254 nm is preferable. It is also possible to use an ozone-less high-pressure mercury lamp and a low-pressure mercury lamp. Regarding the amount of processed light, the greater the amount of processed light, the better the adhesive strength between the thermoplastic saturated alicyclic structure-containing polymer resin film and the polarizer, but the problem is that the film becomes colored and becomes brittle as the amount of light increases. appear. Therefore, a high-pressure mercury lamp having a main wavelength of 365 nm has a good irradiation light quantity of 20 to 10000 (mJ / cm ² ), more preferably 50 to 2000 (mJ / cm ² ). In the case of low-pressure mercury lamp for a 254nm main wavelength, the irradiation light amount 100~10000 (mJ / cm ²⁾ C., more preferably 300~1500 (mJ / cm ^2).

Furthermore, in the present invention, it is also preferable to perform a corona discharge treatment as the surface treatment. For example, it can be carried out by the processing methods described in JP-B-39-12838, JP-A-47-19824, JP-A-48-28067, and JP-A-52-42114. As the corona discharge treatment apparatus, a solid state corona treatment machine manufactured by Pillar, a LEPEL type surface treatment machine, a VETAPHON type treatment machine, or the like can be used. The treatment can be performed at normal pressure in air. The discharge frequency during the treatment is 5 to 40 KV, more preferably 10 to 30 KV, and the waveform is preferably an AC sine wave. The gap transparent lance between the electrode and the dielectric roll is 0.1 to 10 mm, more preferably 1.0 to 2.0 mm. The discharge is processed above a dielectric support roller provided in the discharge zone, and the treatment amount is 0.3 to 0.4 KV · A · min / m ² , more preferably 0.34 to 0.38 KV · A ·. Min / m ² .

In the present invention, it is also preferable to perform a flame treatment as the surface treatment. The gas used may be natural gas, liquefied propane gas, or city gas, but the mixing ratio with air is important. This is because the effect of surface treatment by flame treatment is thought to be brought about by plasma containing active oxygen, and the point is how much plasma activity (temperature) and oxygen are important properties of flame. is there. The governing factor of this point is the gas / oxygen ratio. When the reaction is carried out without excess or deficiency, the energy density is the highest and the plasma activity is increased. Specifically, the preferable mixing ratio of natural gas / air is 1/6 to 1/10, preferably 1/7 to 1/9 in volume ratio. In the case of liquefied propane gas / air, 1/14 to 1/22, preferably 1/16 to 1/19, and in the case of city gas / air, 1/2 to 1/8, preferably 1/3 to 1. / 7. Further, the flame treatment amount is 1 to 50 Kcal / m ² , more preferably 3 to 20 Kcal / m ² . Further, the distance between the tip of the burner inner flame and the film is preferably 3 to 7 cm, more preferably 4 to 6 cm. The burner nozzle shapes are: Flynburner (USA) ribbon type, Wise (USA) multi-hole type, Aerogen (UK) ribbon type, Kasuga Electric (Japan) staggered multi-hole type, Koike Oxygen ( Japan) is preferred. The backup roll that supports the film for the flame treatment is a hollow roll, and is preferably cooled at a constant temperature of 20 to 50 ° C. by cooling with cooling water.

  As for the degree of surface treatment, the preferred range varies depending on the type of surface treatment and the type of cyclic polyolefin, but as a result of the surface treatment, the contact angle with the pure water on the surface of the protective film subjected to the surface treatment is less than 50 °. It is preferable that The contact angle is more preferably 25 ° or more and less than 45 °. When the contact angle of the protective film surface with pure water is within the above range, the adhesive strength between the protective film and the polarizing film is improved.

(adhesive)
In the present invention, when a polarizer made of polyvinyl alcohol and a protective film made of a surface-treated thermoplastic saturated alicyclic structure-containing polymer resin are bonded, an adhesive containing a water-soluble polymer is used. .
Water-soluble polymers preferably used for the adhesive include N-vinylpyrrolidone, acrylic acid, methacrylic acid, maleic acid, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, vinyl alcohol, methyl vinyl ether, vinyl acetate. , Acrylamide, methacrylamide, diacetone acrylamide, vinyl imidazole and other homopolymers or copolymers having ethylenically unsaturated monomers, polyoxyethylene, polyoxypropylene, poly-2-methyloxazoline, methylcellulose, hydroxy Examples thereof include ethyl cellulose and hydroxypropyl cellulose gelatin. Of these, PVA and gelatin are preferred in the present invention.

The preferable PVA characteristic when using PVA for the adhesive is the same as the preferable characteristic of PVA used for the above-mentioned polarizer. In the present invention, it is preferable to use a crosslinking agent in combination. Examples of the cross-linking agent that is preferably used in combination with PVA as an adhesive include boric acid, polyvalent aldehyde, polyfunctional isocyanate compound, and polyfunctional epoxy compound, but boric acid is particularly preferred in the present invention.
When gelatin is used for the adhesive, so-called lime-processed gelatin, acid-processed gelatin, enzyme-processed gelatin, gelatin derivatives and modified gelatin can be used. Of these gelatins, lime-processed gelatin and acid-processed latin are preferably used. When gelatin is used for the adhesive, the crosslinking agent preferably used in combination is an active halogen compound (2,4-dichloro-6-hydroxy-1,3,5-triazine and its sodium salt) and an active vinyl compound ( 1,3-bisvinylsulfonyl-2-propanol, 1,2-bisvinylsulfonylacetamido) ethane, bis (vinylsulfonylmethyl) ether or vinyl polymers having a vinylsulfonyl group in the side chain), N-carbamoylpyridinium salts ((1-morpholinocarbonyl-3-pyridinio) methanesulfonate, etc.) and haloamidinium salts (1- (1-chloro-1-pyridinomethylene) pyrrolidinium 2-naphthalenesulfonate, etc.). In the present invention, active halogen compounds and active vinyl compounds are particularly preferably used.

  When the above-mentioned crosslinking agent is used in combination, the preferred addition amount of the crosslinking agent is 0.1% by mass or more and less than 40% by mass, more preferably 0.5% by mass with respect to the water-soluble polymer in the adhesive. As mentioned above, it is less than 30 mass%. It is preferable to apply an adhesive to at least one surface of the protective film or the polarizer to form an adhesive layer, and to bond the adhesive film, and then apply the adhesive to the surface-treated surface of the protective film to form an adhesive layer. Is preferably bonded to the surface of the polarizer. The thickness of the adhesive layer is preferably 0.01 to 5 μm, and particularly preferably 0.05 to 3 μm after drying.

2. Next, the cellulose acylate film of the present invention will be described.

[Cellulose acylate raw cotton]
Cellulose acylate raw material cellulose used in the present invention includes cotton linter and wood pulp (hardwood pulp, softwood pulp) and the like, 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, Marusawa and Uda, “Plastic Materials Course (17) Fibrous Resin” (published by Nikkan Kogyo Shimbun, published in 1970), and the Japan Institute of Invention and Technology Publication No. 2001. The cellulose described in No.-1745 (pages 7 to 8) can be used, and is not particularly limited to the cellulose acylate film of the present invention.

[Substitution degree of cellulose acylate]
Next, the cellulose acylate of the present invention produced from the above-mentioned cellulose will be described. The cellulose acylate of the present invention is obtained by acylating a hydroxyl group of cellulose, and the substituent can be any acetyl group having 2 carbon atoms in the acyl group to those having 22 carbon atoms. In the cellulose acylate of the present invention, the degree of substitution of cellulose with a hydroxyl group is not particularly limited. You can get a degree. As a measuring method, it can carry out according to ASTM D-817-91.

  As described above, in the cellulose acylate of the present invention, the degree of substitution of the cellulose with a hydroxyl group is not particularly limited, but the degree of acyl substitution with the hydroxyl group of cellulose is preferably 2.50 to 3.00. Furthermore, the substitution degree is preferably 2.75 to 3.00, and more preferably 2.85 to 3.00.

  Among the acetic acid substituted for the hydroxyl group of cellulose and / or the fatty acid having 3 to 22 carbon atoms, the acyl group having 2 to 22 carbon atoms is not particularly limited and may be an aliphatic group or an allyl group. A mixture of the above may also be used. These are, for example, cellulose alkylcarbonyl esters, alkenylcarbonyl esters, aromatic carbonyl esters, aromatic alkylcarbonyl esters, and the like, each of which may further have a substituted group. These preferred acyl groups include acetyl, propionyl, butanoyl, heptanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, iso-butanoyl, t-butanoyl, cyclohexanecarbonyl, Examples include oleoyl, benzoyl, naphthylcarbonyl, and cinnamoyl groups. Among these, acetyl, propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, oleoyl, benzoyl, naphthylcarbonyl, cinnamoyl and the like are preferable, and acetyl, propionyl and butanoyl are more preferable.

  Among the acyl substituents substituted on the hydroxyl group of cellulose described above, in the case of substantially consisting of at least two types of acetyl group / propionyl group / butanoyl group, the total degree of substitution is 2.50 to 3.00 In addition, the optical anisotropy of the cellulose acylate film can be reduced. The degree of acyl substitution is more preferably 2.60 to 3.00, and even more preferably 2.65 to 3.00.

[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 Uda et al.'S intrinsic viscosity method (Kazuo Uda, Hideo Saito, Journal of Textile Society, Vol. This is described in detail in JP-A-9-95538.
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 a mass average molecular weight, Mn is a number average molecular weight) is small, and the 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 pages 7 to 12 in the raw material cotton and the synthesis method in the Japan Society for Invention and Innovation Technical Bulletin No. 2001-1745 (issued 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 (for example, compounds that reduce optical anisotropy, wavelength dispersion regulators, ultraviolet inhibitors, plasticizers, deterioration inhibitors) according to applications in each preparation step. , Fine particles, optical property modifiers, etc.) can be added and these are described below. Further, the addition may be performed at any time in the dope preparation process, but may be performed by adding an additive to the final preparation process of the dope preparation process.
A compound that reduces the optical anisotropy of the cellulose acylate film of the invention, particularly the retardation Rth in the film thickness direction represented by Rth = ((nx + ny) / 2-nz) × d is represented by the following formula (IV ) And (V) are preferably contained within the range satisfying (V).
(IV) (Rth (A) −Rth (0)) / A ≦ −1.0
(V) 0.01 ≦ A ≦ 30
The above formulas (IV) and (V) are: (IV) (Rth (A) −Rth (0)) / A ≦ −2.0
(V) 0.05 ≦ A ≦ 25
It is more desirable to be
(IV) (Rth (A) −Rth (0)) / A ≦ −3.0
(V) 0.1 ≦ A ≦ 20
It is even more desirable.
here,
Rth (A): Rth (nm) of a film containing A% of a compound that lowers Rth
Rth (0): Rth (nm) of a film not containing a compound that lowers Rth
A: Mass (%) of the compound when the mass of the film raw material polymer is 100
It is.

[Structural characteristics of compounds that reduce the optical anisotropy of cellulose acylate films]
The compound that reduces the optical anisotropy of the cellulose acylate film will be described. Optical anisotropy was sufficiently reduced by using a compound that suppresses in-plane and film thickness direction orientation of cellulose acylate in the film so that Re was zero and Rth was close to zero. For this purpose, it is advantageous that the compound that lowers the optical anisotropy is sufficiently compatible with cellulose acylate, and the compound itself does not have a rod-like structure or a planar structure. Specifically, when a plurality of planar functional groups such as aromatic groups are provided, a structure having these functional groups in a non-planar rather than the same plane is advantageous.

(Log P value)
In producing the cellulose acylate film of the present invention, octanol is among the compounds that reduce the optical anisotropy by inhibiting the cellulose acylate in the film from being oriented in the plane and in the film thickness direction as described above. -Compounds with a water partition coefficient (log P value) of 0 to 7 are preferred. A compound having a log P value of more than 7 is poor in compatibility with cellulose acylate, and tends to cause film turbidity or powder blowing. In addition, since a compound having a log P value smaller than 0 has high hydrophilicity, the water resistance of the cellulose acetate film may be deteriorated. A more preferable range of the logP value is 1 to 6, and a particularly preferable range is 1.5 to 5.
The octanol-water partition coefficient (log P value) can be measured by a flask immersion method described in JIS Japanese Industrial Standard Z7260-107 (2000). Further, the octanol-water partition coefficient (log P value) can be estimated by a computational chemical method or an empirical method instead of the actual measurement. As a calculation method, Crippen's fragmentation method (J. Chem. Inf. Comput. Sci., 27, 21 (1987)), Viswanadhan's fragmentation method (J. Chem. Inf. Comput. Sci., 29, 163). (1989)), Broto's fragmentation method (Eur. J. Med. Chem.-Chim. Theor., 19, 71 (1984)) and the like are preferably used, but the Crippen's fragmentation method (J. Chem. Inf .Comput.Sci., 27, 21 (1987)) is more preferable. When the log P value of a certain compound varies depending on the measurement method or calculation method, it is preferable to determine whether or not the compound is within the scope of the present invention by the Crippen's fragmentation method.

[Physical properties of compounds that reduce optical anisotropy]
The compound that reduces optical anisotropy may or may not contain an aromatic group. The compound that reduces the optical anisotropy preferably has a molecular weight of 150 or more and 3000 or less, preferably 170 or more and 2000 or less, and particularly preferably 200 or more and 1000 or less. A specific monomer structure may be used as long as these molecular weights are within the range, and an oligomer structure or a polymer structure in which a plurality of the monomer units are bonded may be used.
The compound that reduces optical anisotropy is preferably a liquid at 25 ° C. or a solid having a melting point of 25 to 250 ° C., more preferably a liquid at 25 ° C. or a melting point of 25 to 200 ° C. It is a solid. Moreover, it is preferable that the compound which reduces optical anisotropy does not volatilize in the process of dope casting for cellulose acylate film production and drying.
The addition amount of the compound that decreases the optical anisotropy is preferably 0.01 to 30% by mass, more preferably 1 to 25% by mass, and more preferably 5 to 20% by mass of the cellulose acylate. Is particularly preferred.
The compound that decreases the optical anisotropy may be used alone, or two or more compounds may be mixed and used in an arbitrary ratio.
The timing for adding the compound for reducing the optical anisotropy may be any time during the dope preparation process, or may be performed at the end of the dope preparation process.

  The compound that reduces the optical anisotropy is such that the average content of the compound in the portion from the surface on at least one side to 10% of the total film thickness is the average content of the compound in the central portion of the cellulose acylate film. 80-99%. The abundance of the compound of the present invention can be determined, for example, by measuring the amount of the compound at the surface and in the center by the method using an infrared absorption spectrum described in JP-A-8-57879.

  Although the specific example of the compound which reduces the optical anisotropy of the cellulose acylate film preferably used by this invention below is shown, this invention is not limited to these compounds.

  The value of logP described in the present invention is determined by the Crippen's fragmentation method (J. Chem. Inf. Comput. Sci., 27, 21 (1987)).

  General formula (1):

In the general formula (1), R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represent a hydrogen atom, an alkyl group, or an aryl group. Further, the total number of carbon atoms of R ¹ , R ² and R ³ is particularly preferably 10 or more. As the substituent, a fluorine atom, an alkyl group, an aryl group, an alkoxy group, a sulfone group, and a sulfonamide group are preferable, and an alkyl group, an aryl group, an alkoxy group, a sulfone group, and a sulfonamide group are particularly preferable. Further, the alkyl group may be linear, branched or cyclic, and preferably has 1 to 25 carbon atoms, more preferably 6 to 25, and more preferably 6 to 20 (E.g., methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, amyl, isoamyl, t-amyl, hexyl, cyclohexyl, heptyl, octyl, bicyclooctyl, nonyl, adamantyl, decyl, t-octyl, undecyl, Dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, didecyl) are particularly preferred. As the aryl group, those having 6 to 30 carbon atoms are preferable, and those having 6 to 24 carbon atoms (for example, phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, triphenylphenyl) are particularly preferable. Although the preferable example of a compound represented by General formula (1) is shown below, this invention is not limited to these specific examples.

  General formula (2):

In the formula, R ³¹ represents an alkyl group or an aryl group, and R ³² and R ³³ each independently represent a hydrogen atom, an alkyl group, or an aryl group. Here, the alkyl group may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and 1 to 12 carbon atoms. Is most preferred. As the cyclic alkyl group, a cyclohexyl group is particularly preferable. The aryl group preferably has 6 to 36 carbon atoms, and more preferably 6 to 24 carbon atoms.

  The above alkyl group and aryl group may have a substituent. Examples of the substituent include a halogen atom (for example, chlorine, bromine, fluorine and iodine), an alkyl group, an aryl group, an alkoxy group, an aryloxy group, An acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a sulfonylamino group, a hydroxy group, a cyano group, an amino group, and an acylamino group are preferable, and a halogen atom, an alkyl group, an aryl group, an alkoxy group, and an aryloxy are more preferable. Group, sulfonylamino group and acylamino group, particularly preferably alkyl group, aryl group, sulfonylamino group and acylamino group.

  Although the preferable example of a compound represented by General formula (2) below is shown below, this invention is not limited to these specific examples.

[Wavelength dispersion modifier]
A compound for reducing the wavelength dispersion of the cellulose acylate film (hereinafter also referred to as a wavelength dispersion adjusting agent) will be described. In order to improve the Rth wavelength dispersion of the cellulose acylate film of the present invention, a compound that decreases the Rth wavelength dispersion represented by ΔRth = | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ | It is desirable to contain at least one type within the range of satisfying VI) and (VII).
(VI) (ΔRth (B) −ΔRth (0)) / B ≦ −2.0
(VII) 0.01 ≦ B ≦ 30
In the above formulas (VI) and (VII), (VI) (ΔRth (B) −ΔRth (0)) / B ≦ −3.0
(VII) 0.05 ≦ B ≦ 25
It is more desirable to be
(VI) (ΔRth (B) −ΔRth (0)) / B ≦ −4.0
(VII) 0.1 ≦ B ≦ 20
It is even more desirable.
here,
Rth ₍₄₀₀₎ : Rth (nm) at 400 nm,
Rth ₍₇₀₀₎ : Rth (nm) at 700 nm,
ΔRth (B): ΔRth (nm) of a film containing B mass% of a compound that reduces ΔRth,
ΔRth (0): ΔRth (nm) of a film not containing a compound that reduces ΔRth,
B: Mass of compound (%) when the mass of the film raw material polymer is 100
It is.

  In general, the Re and Rth values of the cellulose acylate film have a wavelength dispersion characteristic that the longer wavelength side is larger than the shorter wavelength side. Therefore, it is required to smooth the chromatic dispersion by increasing Re and Rth on the relatively short wavelength side. On the other hand, a compound having absorption in the ultraviolet region of 200 to 400 nm has a wavelength dispersion characteristic in which the absorbance on the long wavelength side is larger than that on the short wavelength side. If the compound itself is isotropically present inside the cellulose acylate film, it is assumed that the birefringence of the compound itself, and thus the wavelength dispersion of Re and Rth, is large on the short wavelength side as well as the wavelength dispersion of absorbance. .

  Therefore, as described above, by using the compound having absorption in the ultraviolet region of 200 to 400 nm and assuming that the wavelength dispersion of Re and Rth of the compound itself is large on the short wavelength side, the Re and Rth of the cellulose acylate film are used. Chromatic dispersion can be prepared. For this purpose, the compound for adjusting the wavelength dispersion is required to be sufficiently homogeneously compatible with the cellulose acylate. The absorption band range in the ultraviolet region of such a compound is preferably 200 to 400 nm, more preferably 220 to 395 nm, and even more preferably 240 to 390 nm.

In recent years, liquid crystal display devices such as televisions, notebook personal computers, and mobile portable terminals have been required to have excellent transmittance of optical members used in liquid crystal display devices in order to increase luminance with less power. In that respect, a cellulose acylate film is a compound having absorption in the ultraviolet region of 200 to ₄₀₀ nm and reducing | Re ₍₄₀₀₎ -Re ₍₇₀₀₎ | and | Rth ₍₄₀₀₎ -Rth ₍₇₀₀₎ | When it is added, it is required to have excellent spectral transmittance. In the cellulose acylate film of the present invention, the spectral transmittance at a wavelength of 380 nm is preferably 45% or more and 95% or less, and the spectral transmittance at a wavelength of 350 nm is preferably 10% or less.

  As described above, the wavelength dispersion adjusting agent preferably used in the present invention preferably has a molecular weight of 250 to 1000 from the viewpoint of volatility. More preferably, it is 260-800, More preferably, it is 270-800, Most preferably, it is 300-800. A specific monomer structure may be used as long as these molecular weights are within the range, and an oligomer structure or a polymer structure in which a plurality of the monomer units are bonded may be used.

  It is preferable that the wavelength dispersion adjusting agent does not volatilize during the dope casting and drying process for producing the cellulose acylate film.

(Compound addition amount)
The addition amount of the chromatic dispersion adjusting agent preferably used in the present invention is preferably 0.01 to 30% by mass, more preferably 0.1 to 20% by mass, more preferably 0.1 to 20% by mass of the cellulose acylate. 2 to 10% by weight is particularly preferred.

(Method of compound addition)
These wavelength dispersion adjusting agents may be used alone or in combination of two or more compounds at an arbitrary ratio.
Further, the timing of adding these wavelength dispersion adjusting agents may be any time during the dope preparation process, or may be performed at the end of the dope preparation process.

  Specific examples of the wavelength dispersion adjusting agent preferably used in the present invention include, for example, benzotriazole compounds, benzophenone compounds, cyano group-containing compounds, oxybenzophenone compounds, salicylic acid ester compounds, nickel complex compounds, and the like. However, the present invention is not limited to these compounds.

  As the benzotriazole-based compound, those represented by the general formula (101) are preferably used as the wavelength dispersion adjusting agent of the present invention.

Formula (101) Q ¹ -Q ² -OH

(In the formula, Q ¹ represents a nitrogen-containing aromatic heterocycle Q ² represents an aromatic ring.)

Q ¹ represents a nitrogen-containing aromatic heterocycle, preferably a 5- to 7-membered nitrogen-containing aromatic heterocycle, more preferably a 5- to 6-membered nitrogen-containing aromatic heterocycle, such as imidazole , Pyrazole, triazole, tetrazole, thiazole, oxazole, selenazole, benzotriazole, benzothiazole, benzoxazole, benzoselenazole, thiadiazole, oxadiazole, naphthothiazole, naphthoxazole, azabenzimidazole, purine, pyridine, pyrazine, pyrimidine, And pyridazine, triazine, triazaindene, tetrazaindene, and the like. More preferably, it is a 5-membered nitrogen-containing aromatic heterocycle, specifically, imidazole, pyrazole, triazole, tetrazole, thiazole, oxazo. Benzotriazole, benzothiazole, benzoxazole, thiadiazole and oxadiazole are preferred, and benzotriazole is particularly preferred.
The nitrogen-containing aromatic heterocycle represented by Q ¹ may further have a substituent, and the substituent T described below can be applied as the substituent. In addition, when there are a plurality of substituents, each may be condensed to form a ring.

The aromatic ring represented by Q ² may be an aromatic hydrocarbon ring or an aromatic heterocycle. These may be monocyclic or may form a condensed ring with another ring.
The aromatic hydrocarbon ring is preferably (preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (for example, benzene ring, naphthalene ring etc.), more preferably 6 carbon atoms. -20 aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms.) More preferred is a benzene ring.
The aromatic heterocycle is preferably an aromatic heterocycle containing a nitrogen atom or a sulfur atom. Specific examples of the heterocyclic ring include, for example, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, isoquinoline, Examples include phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzthiazole, benzotriazole, and tetrazaindene. Preferred examples of the aromatic heterocycle include pyridine, triazine, and quinoline.
The aromatic ring represented by Q ² is preferably an aromatic hydrocarbon ring, more preferably a naphthalene ring or a benzene ring, and particularly preferably a benzene ring. Q ² may further have a substituent, and the substituent T described later is preferable.
Examples of the substituent T include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms such as methyl, ethyl, iso-propyl, tert-butyl, and n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2 to 8, for example, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), an alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2-8, for example, propargyl, 3-pentynyl, etc.), aryl groups (preferably having 6-30 carbon atoms) More preferably, it has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyl, p-methylphenyl, naphthyl and the like, and a substituted or unsubstituted amino group (preferably having 0 to 0 carbon atoms). 20, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, etc.), an alkoxy group (preferably having a carbon number) 1 to 20, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy, ethoxy, butoxy, etc.), an aryloxy group (preferably 6 to 20 carbon atoms, more Preferably it has 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy, 2-naphthyloxy and the like. An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include acetyl, benzoyl, formyl, and pivaloyl). An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, etc.), an aryloxycarbonyl group ( Preferably it has 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, and examples thereof include phenyloxycarbonyl, etc.), an acyloxy group (preferably 2 to 20 carbon atoms, More preferably, it has 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms. Nzoyloxy and the like. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino), alkoxycarbonylamino group (Preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino), aryloxycarbonylamino group (preferably having carbon number) 7 to 20, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino, and the like, and sulfonylamino groups (preferably 1 to 20 carbon atoms, more preferably Has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms. And sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl and methylsulfamoyl). , Dimethylsulfamoyl, phenylsulfamoyl, etc.), a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl). , Methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio, Ethylthio etc.), arylthio group (preferably Has 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, and a sulfonyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl, tosyl, etc.), sulfinyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably Has 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms). For example, ureido, methylureido, phenylureido, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms) More preferably, it is C1-C16, Most preferably, it is C1-C12, for example, diethyl phosphoric acid amide, phenylphosphoric acid amide etc. are mentioned. ), Hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, Heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, specifically, for example, imidazolyl, pyridyl, quinolyl, furyl, piperidyl , Morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, and particularly preferably 3 to 24 carbon atoms). For example, trimethylsilyl, triphenylsilyl, etc.) . These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

As the general formula (101), a compound represented by the following general formula (101-A) is preferable.
General formula (101-A)

(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ each independently represents a hydrogen atom or a substituent)

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , and R ⁹ each independently represent a hydrogen atom or a substituent. Applicable. These substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure.
R ¹ and R ³ are preferably hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, substituted or unsubstituted amino groups, alkoxy groups, aryloxy groups, hydroxy groups, and halogen atoms, more preferably hydrogen atoms. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group and a halogen atom, more preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, particularly preferably an alkyl group having 1 to 12 carbon atoms (preferably 4 to 12 carbon atoms).

R ² and R ⁴ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably A hydrogen atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, more preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, particularly preferably a hydrogen atom and a methyl group, most preferably Is a hydrogen atom.

R ⁵ and R ⁸ are preferably hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, substituted or unsubstituted amino groups, alkoxy groups, aryloxy groups, hydroxy groups, and halogen atoms, more preferably hydrogen atoms. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, more preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, particularly preferably a hydrogen atom and a methyl group, most preferably It is a hydrogen atom.

R ⁶ and R ⁷ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably a hydrogen atom. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, more preferably a hydrogen atom and a halogen atom, and particularly preferably a hydrogen atom and a chlorine atom.

More preferable as the general formula (101) is a compound represented by the following general formula (101-B).
General formula (101-B)

(In formula, R < ¹ >, R < ³ >, R < ⁶ > and R < ⁷ > are synonymous with those in general formula (101-A), and their preferred ranges are also the same.)

  Specific examples of the compound represented by formula (101) are listed below, but the present invention is not limited to the following specific examples.

  Among the benzotriazole compounds exemplified in the above examples, when the cellulose acylate film of the present invention was produced without including those having a molecular weight of 320 or less, it was confirmed that it was advantageous in terms of retention.

In addition, as the benzophenone compound which is one of the wavelength dispersion adjusting agents used in the present invention, those represented by the general formula (102) are preferably used.
Formula (102)

(In the formula, Q ¹ and Q ² each independently represent an aromatic ring. X represents NR (R represents a hydrogen atom or a substituent), an oxygen atom or a sulfur atom.)

The aromatic ring represented by Q ¹ and Q ² may be an aromatic hydrocarbon ring or an aromatic heterocycle. These may be monocyclic or may form a condensed ring with another ring.
The aromatic hydrocarbon ring represented by Q ¹ and Q ² is preferably (preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (for example, a benzene ring, a naphthalene ring, etc.). More preferably an aromatic hydrocarbon ring having 6 to 20 carbon atoms, still more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms.) More preferably, it is a benzene ring.
The aromatic heterocycle represented by Q ¹ and Q ² is preferably an aromatic heterocycle containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom. Specific examples of the heterocyclic ring include, for example, furan, pyrrole, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, Examples include quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzothiazole, benzotriazole, and tetrazaindene. Preferred examples of the aromatic heterocycle include pyridine, triazine, and quinoline.
The aromatic ring represented by Q ¹ and Q ² is preferably an aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 10 carbon atoms, still more preferably a substituted or unsubstituted benzene ring. is there.
Q ¹ and Q ² may further have a substituent, and the substituent T described later is preferable, but the substituent does not contain a carboxylic acid, a sulfonic acid, or a quaternary ammonium salt. Further, if possible, substituents may be linked to form a ring structure.

  X represents NR (R represents a hydrogen atom or a substituent. Substituent T described later can be applied as the substituent), an oxygen atom or a sulfur atom, and X is preferably NR (R is preferably an acyl group) , A sulfonyl group, and these substituents may be further substituted.), Or O, particularly preferably O.

  Examples of the substituent T include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms such as methyl, ethyl, iso-propyl, tert-butyl, and n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2 to 8, for example, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), an alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2-8, for example, propargyl, 3-pentynyl, etc.), aryl groups (preferably having 6-30 carbon atoms) More preferably, it has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyl, p-methylphenyl, naphthyl and the like, and a substituted or unsubstituted amino group (preferably having 0 to 0 carbon atoms). 20, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, etc.), an alkoxy group (preferably having a carbon number) 1 to 20, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy, ethoxy, butoxy, etc.), an aryloxy group (preferably 6 to 20 carbon atoms, more Preferably it has 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy, 2-naphthyloxy and the like. An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include acetyl, benzoyl, formyl, and pivaloyl). An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, etc.), an aryloxycarbonyl group ( Preferably it has 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, and examples include phenyloxycarbonyl, etc.), an acyloxy group (preferably 2 to 20 carbon atoms, More preferably, it has 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms. Nzoyloxy and the like. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino), alkoxycarbonylamino group (Preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino), aryloxycarbonylamino group (preferably having carbon number) 7 to 20, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino, and the like, and sulfonylamino groups (preferably 1 to 20 carbon atoms, more preferably Has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms. And sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, and particularly preferably 0 to 12 carbon atoms, such as sulfamoyl and methylsulfamoyl). , Dimethylsulfamoyl, phenylsulfamoyl, etc.), a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl). , Methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio, Ethylthio etc.), arylthio group (preferably Has 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, and a sulfonyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl, tosyl, etc.), sulfinyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably Has 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms). For example, ureido, methylureido, phenylureido, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms) More preferably, it is C1-C16, Most preferably, it is C1-C12, for example, diethyl phosphoric acid amide, phenylphosphoric acid amide etc. are mentioned. ), Hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, Heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, specifically, for example, imidazolyl, pyridyl, quinolyl, furyl, piperidyl , Morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, and particularly preferably 3 to 24 carbon atoms). For example, trimethylsilyl, triphenylsilyl, etc.) . These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

As the general formula (102), a compound represented by the following general formula (102-A) is preferable.
Formula (102-A)

(In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , and R ⁹ each independently represents a hydrogen atom or a substituent.)

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , and R ⁹ each independently represent a hydrogen atom or a substituent. Applicable. These substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure.

R ¹ , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁸ and R ⁹ are preferably a hydrogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, substituted or unsubstituted amino group, alkoxy group, aryl An oxy group, a hydroxy group and a halogen atom, more preferably a hydrogen atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group and a halogen atom, still more preferably a hydrogen atom and a carbon 1-12 alkyl group. Particularly preferred are a hydrogen atom and a methyl group, and most preferred is a hydrogen atom.

R ² is preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, a halogen atom, more preferably a hydrogen atom or one carbon atom. An alkyl group having -20 carbon atoms, an amino group having 0-20 carbon atoms, an alkoxy group having 1-12 carbon atoms, an aryloxy group having 6-12 carbon atoms, and a hydroxy group, and more preferably an alkoxy group having 1-20 carbon atoms. And particularly preferably an alkoxy group having 1 to 12 carbon atoms.

R ⁷ is preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, a halogen atom, more preferably a hydrogen atom or one carbon atom. An alkyl group having -20 carbon atoms, an amino group having 0-20 carbon atoms, an alkoxy group having 1-12 carbon atoms, an aryloxy group having 6-12 carbon atoms, and a hydroxy group, more preferably a hydrogen atom, having 1-20 carbon atoms. An alkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably a methyl group), particularly preferably a methyl group or a hydrogen atom.

More preferable as the general formula (102) is a compound represented by the following general formula (102-B).
General formula (102-B)

(Wherein R ¹⁰ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aryl group.)

R ¹⁰ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aryl group. Applicable.
R ¹⁰ is preferably a substituted or unsubstituted alkyl group, more preferably a substituted or unsubstituted alkyl group having 5 to 20 carbon atoms, and still more preferably a substituted or unsubstituted alkyl group having 5 to 12 carbon atoms. (Including n-hexyl group, 2-ethylhexyl group, n-octyl group, n-decyl group, n-dodecyl group, benzyl group, etc.), particularly preferably a substitution of 6 to 12 carbon atoms or It is an unsubstituted alkyl group (2-ethylhexyl group, n-octyl group, n-decyl group, n-dodecyl group, benzyl group).

The compound represented by the general formula (102) can be synthesized by a known method described in JP-A-11-12219.
Specific examples of the compound represented by the general formula (102) are given below, but the present invention is not limited to the following specific examples.

As the compound containing a cyano group, which is one of the wavelength dispersion adjusting agents used in the present invention, those represented by the general formula (103) are preferably used.
General formula (103)

(In the formula, Q ¹ and Q ² each independently represent an aromatic ring. X ¹ and X ² represent a hydrogen atom or a substituent, and at least one of them represents a cyano group, a carbonyl group, a sulfonyl group, an aromatic group. Represents an aromatic ring.) The aromatic ring represented by Q ¹ and Q ² may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. These may be monocyclic or may form a condensed ring with another ring.

  The aromatic hydrocarbon ring is preferably (preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (for example, benzene ring, naphthalene ring etc.), more preferably 6 carbon atoms. -20 aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms.) More preferred is a benzene ring.

  The aromatic heterocycle is preferably an aromatic heterocycle containing a nitrogen atom or a sulfur atom. Specific examples of the heterocyclic ring include, for example, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, isoquinoline, Examples include phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzthiazole, benzotriazole, and tetrazaindene. Preferred examples of the aromatic heterocycle include pyridine, triazine, and quinoline.

The aromatic ring represented by Q ¹ and Q ² is preferably an aromatic hydrocarbon ring, and more preferably a benzene ring.
Q ¹ and Q ² may further have a substituent, and a substituent T described later is preferable. Examples of the substituent T include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms such as methyl, ethyl, iso-propyl, tert-butyl, and n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2 to 8, for example, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), an alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2-8, for example, propargyl, 3-pentynyl, etc.), aryl groups (preferably having 6-30 carbon atoms) More preferably, it has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyl, p-methylphenyl, naphthyl and the like, and a substituted or unsubstituted amino group (preferably having 0 to 0 carbon atoms). 20, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, etc.), an alkoxy group (preferably having a carbon number) 1 to 20, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy, ethoxy, butoxy, etc.), an aryloxy group (preferably 6 to 20 carbon atoms, more Preferably it has 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy, 2-naphthyloxy and the like. An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include acetyl, benzoyl, formyl, and pivaloyl). An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, etc.), an aryloxycarbonyl group ( Preferably it has 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, and examples thereof include phenyloxycarbonyl, etc.), an acyloxy group (preferably 2 to 20 carbon atoms, More preferably, it has 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms. Nzoyloxy and the like. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino), alkoxycarbonylamino group (Preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino), aryloxycarbonylamino group (preferably having carbon number) 7 to 20, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino, and the like, and sulfonylamino groups (preferably 1 to 20 carbon atoms, more preferably Has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms. And sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl and methylsulfamoyl). , Dimethylsulfamoyl, phenylsulfamoyl, etc.), a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl). , Methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio, Ethylthio etc.), arylthio group (preferably Has 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, and a sulfonyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl, tosyl, etc.), sulfinyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably Has 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms). For example, ureido, methylureido, phenylureido, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms) More preferably, it is C1-C16, Most preferably, it is C1-C12, for example, diethyl phosphoric acid amide, phenylphosphoric acid amide etc. are mentioned. ), Hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, Heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, specifically, for example, imidazolyl, pyridyl, quinolyl, furyl, piperidyl , Morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, and particularly preferably 3 to 24 carbon atoms). For example, trimethylsilyl, triphenylsilyl, etc.) . These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

X ¹ and X ² each represent a hydrogen atom or a substituent, and at least one of them represents a cyano group, a carbonyl group, a sulfonyl group, or an aromatic heterocycle. The substituent T described above can be applied to the substituents represented by X ¹ and X ² . In addition, the substituent represented by X ¹ and X ² may be further substituted with another substituent, and X ¹ and X ² may each be condensed to form a ring structure.

X ¹ and X ² are preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, a nitro group, a carbonyl group, a sulfonyl group, or an aromatic heterocycle, and more preferably a cyano group, a carbonyl group, a sulfonyl group, An aromatic heterocycle, more preferably a cyano group or a carbonyl group, and particularly preferably a cyano group or an alkoxycarbonyl group (—C (═O) OR (R is an alkyl group having 1 to 20 carbon atoms, 6 carbon atoms). ~ 12 aryl groups and combinations thereof.

As the general formula (103), a compound represented by the following general formula (103-A) is preferable.
General formula (103-A)

(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ each independently represents a hydrogen atom or a substituent. X ¹ and X ² Are the same as those in formula (103), and the preferred range is also the same.)

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ each independently represents a hydrogen atom or a substituent. Is applicable. These substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure.

R ¹ , R ² , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁹ , and R ¹⁰ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, An alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably a hydrogen atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, still more preferably a hydrogen atom and carbon 1-12. An alkyl group, particularly preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

R ³ and R ⁸ are preferably hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, substituted or unsubstituted amino groups, alkoxy groups, aryloxy groups, hydroxy groups, halogen atoms, more preferably hydrogen atoms. , An alkyl group having 1 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, and a hydroxy group, more preferably a hydrogen atom and a carbon number. An alkyl group having 1 to 12 carbon atoms and an alkoxy group having 1 to 12 carbon atoms, particularly preferably a hydrogen atom.

More preferable as the general formula (103) is a compound represented by the following general formula (103-B).
General formula (103-B)

(Wherein R ³ and R ⁸ have the same meanings as those in formula (103-A), and preferred ranges are also the same. X ³ represents a hydrogen atom or a substituent.)

X ³ represents a hydrogen atom or a substituent. As the substituent, the above-described substituent T can be applied, and if possible, the substituent may be further substituted with another substituent. X ³ is preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, a nitro group, a carbonyl group, a sulfonyl group or an aromatic heterocyclic ring, more preferably a cyano group, a carbonyl group, a sulfonyl group or an aromatic heterocyclic ring. More preferably a cyano group or a carbonyl group, and particularly preferably a cyano group or an alkoxycarbonyl group (—C (═O) OR (R is an alkyl group having 1 to 20 carbon atoms, an aryl having 6 to 12 carbon atoms). Group and a combination thereof).

More preferred as the general formula (103) is a compound represented by the general formula (103-C).
General formula (103-C)

(Wherein R ³ and R ⁸ have the same meanings as those in formula (103-A), and the preferred ranges are also the same. R ²¹ represents an alkyl group having 1 to 20 carbon atoms.)

R ²¹ is preferably an alkyl group having 2 to 12 carbon atoms, more preferably an alkyl group having 4 to 12 carbon atoms, and still more preferably 6 carbon atoms when both R ³ and R ⁸ are hydrogen. To 12 alkyl groups, particularly preferably n-octyl group, tert-octyl group, 2-ethylhexyl group, n-decyl group, n-dodecyl group, most preferably 2-ethylhexyl group. It is.

When R ³ and R ⁸ are preferably other than hydrogen as R ²¹ , the compound represented by the general formula (103-C) has a molecular weight of 300 or more and an alkyl group having 20 or less carbon atoms. preferable.

  The compound represented by the general formula (103) of the present invention can be synthesized by the method described in Journal of American Chemical Society 63, 3452 (1941).

  Specific examples of the compound represented by the general formula (103) are given below, but the present invention is not limited to the following specific examples.

[Matting agent fine particles]
It is preferable to add fine particles as a matting agent to the cellulose acylate film of the present invention. The fine particles used in the present invention include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, silica Mention may be made of magnesium and calcium phosphates. Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable. The 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 fine particles of silicon dioxide, for example, commercially available products such as Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (above Nippon Aerosil Co., Ltd.) can be used. Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used.

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

In order to obtain a cellulose acylate film having particles having a small secondary average particle size in the present invention, several methods are conceivable when preparing a fine particle dispersion. For example, a method of preparing a fine particle dispersion in which a solvent and fine particles are mixed with stirring in advance, adding this fine particle dispersion to a small amount of cellulose acylate solution separately prepared, 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, after adding a small amount of cellulose ester to the solvent and dissolving with stirring, add the fine particles to this and disperse with a disperser to make this fine particle additive solution, and mix this fine particle additive solution with the dope solution using an inline mixer 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.

[Plasticizer, degradation inhibitor, release agent]
In addition to the above-mentioned compound that optically reduces anisotropy and the wavelength dispersion adjusting agent, the cellulose acylate film of the present invention has various additives (for example, a plasticizer, an ultraviolet ray, etc.) in each preparation step. Inhibitors, degradation inhibitors, release agents, infrared absorbers, etc.), which may be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, mixing of ultraviolet absorbing material at 20 ° C. or lower and 20 ° C. or higher, and similarly, mixing of a plasticizer is described in, for example, JP-A-2001-151901. Furthermore, infrared absorbing dyes are described, for example, in JP-A No. 2001-194522. Moreover, the addition time may be added at any time in the dope preparation step, but may be added by adding an additive to the final preparation step of the dope preparation step. Furthermore, the amount of each material added is not particularly limited as long as the function is manifested. Moreover, when a cellulose acylate film is formed from a multilayer, the kind and addition amount of the additive of each layer may differ. For example, it is described in Japanese Patent Application Laid-Open No. 2001-151902, but these are conventionally known techniques. For these details, materials described in detail on pages 16 to 22 in the Invention Association's public technical bulletin number 2001-1745 (issued on March 15, 2001, Invention Association) are preferably used.

[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 mass of the cellulose acylate. More preferably, it is 10 to 40%, and even more preferably 15 to 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, more preferably 2000 or less, and even more preferably 1000 or less. When the total amount of these compounds is 5% or less, the properties of cellulose acylate alone are likely to be obtained, and there are problems such as that the optical performance and physical strength are likely to vary 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, for the cellulose acylate film of the present invention, a chlorinated halogenated hydrocarbon may be used as the main solvent, and it is described in JIII Journal of Technical Disclosure No. 2001-1745 (pages 12 to 16). As described above, a non-chlorine solvent may be used as the main solvent, and the present invention is not particularly limited to the cellulose acylate film of the present invention.

  In addition, the solvent for the cellulose acylate solution and the film of the present invention is disclosed in the following patents, including its dissolution method, and is a preferred embodiment. They are, for example, JP 2000-95876 A, JP 12-95877 A, JP 10-324774 A, JP 8-152514 A, JP 10-330538 A, JP 9-95538 A. JP, 9-95557, JP 10-235664, JP 12-63534, JP 11-21379, JP 10-182853, JP 10-278056. JP-A-10-279702, JP-A-10-323853, JP-A-10-237186, JP-A-11-60807, JP-A-11-152342, JP-A-11-292988, This is described in, for example, Kaihei 11-60752 and JP-A-11-60752. According to these patents, 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 also 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 solution concentration and filtration steps involved in the dissolution step, the Japan Society of Invention and Innovation Technical Bulletin No. 2001-1745 (issued March 15, 2001, Invention Association) The manufacturing process described in detail on pages 22 to 25 is preferably used.

(Transparency of dope solution)
The dope transparency of the cellulose acylate solution of the present invention is preferably 85% or more. More preferably, it is 88% or more, and more preferably 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 was poured into a 1 cm square glass cell, and the absorbance at 550 nm was measured with a spectrophotometer (UV-3150, Shimadzu Corporation). Only the solvent was measured in advance as a blank, and the transparency of the cellulose acylate solution was 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. As a 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 temporarily 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. 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, a 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 Invention Association Public Technical Bulletin No. 2001-1745 (issued March 15, 2001, Invention Association). 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.

[Change in optical performance of film after high humidity treatment]
[Evaluation of properties of cellulose acylate film]
Regarding the change in the optical performance due to the environmental change of the cellulose acylate film of the present invention, it is preferable that the amount of change in Re and Rth of the film treated at 60 ° C. and 90% RH for 240 hours is 15 nm or less. More preferably, it is 12 nm or less, and more preferably 10 nm or less.
[Change in optical performance of film after high temperature treatment]
Further, it is desirable that the amount of change in Re and Rth of the film treated at 80 ° C. for 240 hours is 15 nm or less. More preferably, it is 12 nm or less, and more preferably 10 nm or less.
[Compound volatilization after film heat treatment]
A compound that lowers Rth and a compound that lowers ΔRth, which can be preferably used in the cellulose acylate film of the present invention, has a volatilization amount of a compound from a film treated at 80 ° C. for 240 hours of 30% or less. I want to see that. More preferably, it is 25% or less, and more preferably 20% or less.
In addition, the amount of volatilization from the film is a compound in which a film treated at 80 ° C. for 240 hours and an untreated film are each dissolved in a solvent, a compound is detected by liquid high-performance chromatography, and the peak area of the compound is left in the film The amount is calculated by the following formula.
Volatilization amount (%) = {(Amount of remaining compound in untreated product) − (Amount of remaining compound in treated product)} / (Amount of remaining compound in untreated product) × 100

[Glass Transition Temperature Tg of Film]
The glass transition temperature Tg of the cellulose acylate film of the present invention is 80 to 165 ° C. From the viewpoint of heat resistance, Tg is more preferably 100 to 160 ° C, and particularly preferably 110 to 150 ° C. The glass transition temperature Tg is measured with a differential scanning calorimeter (DSC2910, T.A. Instrument) using a 10 mg cellulose acylate film sample of the present invention at a temperature rising / lowering rate of 5 ° C./min. To calculate the glass transition temperature Tg.

[Haze of film]
The haze of the cellulose acylate film of the present invention is preferably 0.01 to 2.0%. More preferably, it is 0.05 to 1.5%, and more preferably 0.1 to 1.0%. As an optical film, the transparency of the film is important. The haze is measured by measuring the cellulose acylate film sample 40 mm × 80 mm of the present invention at 25 ° C. and 60% RH with a haze meter (HGM-2DP, Suga Test Instruments) according to JIS K-6714.

[Humidity dependency of Re and Rth of film]
It is preferable that both the in-plane retardation Re and the thickness direction retardation Rth of the cellulose acylate film of the present invention are small in change due to humidity. Specifically, the difference ΔRth (= Rth10% RH−Rth80% RH) between the Rth value at 25 ° C. and 10% RH and the Rth value at 25 ° C. and 80% RH is preferably 0 to 50 nm. More preferably, it is 0-40 nm, More preferably, it is 0-35 nm.

[Equilibrium moisture content of film]
The equilibrium moisture content of the cellulose acylate film of the present invention is 25 ° C. at 80 ° C. regardless of the film thickness so as not to impair the adhesion with a water-soluble polymer such as polyvinyl alcohol when used as a protective film of a polarizing plate. The equilibrium moisture content at% RH is preferably 0 to 4%. It is more preferably 0.1 to 3.5%, and particularly preferably 1 to 3%. When the equilibrium moisture content is 4% or more, the dependency of retardation due to humidity change becomes too large when used as a support for an optical compensation film.
The moisture content is measured by measuring the cellulose acylate film sample 7 mm × 35 mm of the present invention by the Karl Fischer method using a moisture measuring device and a sample drying apparatus (CA-03, VA-05, both Mitsubishi Chemical Corporation). . It is calculated by dividing the amount of water (g) by the sample mass (g).

[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 the conditions of a temperature of 60 ° C. and a humidity of 95% RH based on JIS standard JISZ0208, and converted to a film thickness of 80 μm, 400 to 2000 g / It should be 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 moisture permeability × measured film thickness μm / 80 μm).
The measurement method of moisture permeability is “Polymer Physical Properties II” (Polymer Experiment Course 4, Kyoritsu Shuppan), pages 285-294: Measurement of vapor permeation amount (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) was applied. , Toyo Seiki Co., Ltd.) calculates the amount of water per unit area (g / m ² ) according to JIS Z-0208, and obtains moisture permeability = mass after moisture conditioning−mass before moisture conditioning.

[Dimensional change of film]
The dimensional stability of the cellulose acylate film of the present invention is as follows: dimensional change rate after standing for 24 hours under the conditions of 60 ° C. and 90% RH (high humidity) and the condition of 90 ° C. and 5% RH. It is preferable that the dimensional change rate after standing for 24 hours (high temperature) is 0.5% or less. More preferably, it is 0.3% or less, and even more preferably, it is 0.15% or less.
As a specific measurement method, two cellulose acylate film samples 30 mm × 120 mm were prepared, conditioned at 25 ° C. and 60% RH for 24 hours, and automatically pin gauge (Shinto Kagaku Co., Ltd.) at both ends. Holes with a diameter of 6 mm are opened at an interval of 100 mm to obtain the original punch interval (L0). Punch interval size (L1) after one sample was treated at 60 ° C. and 90% RH for 24 hours, punch after one sample was treated at 90 ° C. and 5% RH for 24 hours The distance dimension (L2) is measured. Measurement was made to a minimum scale of 1/1000 mm at all intervals. Dimensional change rate of 60 ° C. and 90% RH (high humidity) = {| L0−L1 | / L0} × 100, Dimensional change rate of 90 ° C. and 5% RH (high temperature) = {| L0−L2 | / The dimensional change rate is determined as L0} × 100.

[Elastic modulus of film]
(Elastic modulus)
Elastic modulus of the cellulose acylate film of this invention is preferably from 200 to 500 kgf / mm ^2, more preferably 240~470kgf / mm ^2, further preferably 270~440kgf / mm ^2. As a specific measuring method, using Toyo Baldwin's universal tensile tester STM T50BP, the stress at 0.5% elongation is measured in a 23 ° C./70% atmosphere at a tensile rate of 10% / min to obtain the elastic modulus. .

[Photoelastic coefficient of film]
(Photoelastic coefficient)
The photoelastic coefficient of the cellulose acylate film of the present invention is preferably 50 × 10 ⁻¹³ cm ² / dyne or less. It is more preferably 30 × 10 ⁻¹³ cm ² / dyne or less, and further preferably 20 × 10 ⁻¹³ cm ² / dyne or less. As a specific measuring method, a tensile stress is applied to the major axis direction of a 12 mm × 120 mm cellulose acylate film sample, and the retardation at that time is measured with an ellipsometer (M150, JASCO Corporation). The photoelastic coefficient from the amount of change in retardation with respect to

[Front retardation change before and after stretching, detection of slow axis]
A sample of 100 × 100 mm is prepared, and stretched in the machine conveyance direction (MD direction) or the vertical direction (TD direction) under a temperature of 140 ° C. using a fixed uniaxial stretching machine. The front retardation of each sample before and after stretching is measured using an automatic birefringence meter KOBRA21ADH. The detection of the slow axis is determined from the orientation angle obtained during the retardation measurement. It is preferable that the change in Re by stretching is small, specifically, in-plane front retardation (nm) of a film in which Re (n) is stretched by n (%), in-plane of a film in which Re (0) is not stretched It is preferable to have | Re (n) −Re (0) | /n≦1.0 when the front retardation (nm) is satisfied, and | Re (n) −Re (0) | / n ≦ 0. 3 or less is more preferable.

[Direction with slow axis]
When the cellulose acylate film of the present invention is used as a protective film for a polarizer, since the polarizer has an absorption axis in the machine transport direction (MD direction), the slow axis of the cellulose acylate film is near the MD direction or TD. I want to be there. Light leakage and color change can be reduced by making the slow axis parallel or orthogonal to the polarizer. “Near” means that the slow axis and the MD or TD direction are in the range of 0 to 10 °, preferably 0 to 5 °.

[Cellulose acylate film with positive intrinsic birefringence]
When the cellulose acylate film of the present invention is stretched in the direction having a slow axis in the film plane, the front retardation Re increases, and when stretched in the direction perpendicular to the direction having the slow axis, the front retardation Re decreases. Become. This indicates that the intrinsic birefringence is positive, and it is effective to stretch in the direction perpendicular to the slow axis in order to cancel the Re developed in the film. As this method, for example, when the film has a slow axis in the machine conveyance direction (MD direction), it is considered to reduce the front Re by using tenter stretching in a direction perpendicular to MD (TD direction). It is done. As an opposite example, when the TD direction has a slow axis, it is conceivable that the front Re is made smaller by increasing the tension of the machine transport roll in the MD direction and stretching.

[Cellulose acylate film with negative intrinsic birefringence]
When the cellulose acylate film of the present invention is stretched in a direction having a slow axis, the front retardation Re may be reduced, and when stretched in a direction perpendicular to the direction having a slow axis, the front retardation Re may be increased. This indicates that the intrinsic birefringence is negative, and it is effective to stretch in the same direction as the slow axis in order to cancel out the Re developed in the film. As this method, for example, when the film has a slow axis in the machine conveyance direction (MD direction), the front Re can be reduced by increasing the tension of the machine conveyance roll in the MD direction and stretching. . As an opposite example, when the TD direction has a slow axis, it is conceivable to reduce the front Re by using tenter stretching in a direction perpendicular to the MD (TD direction).

[Method for Evaluating Cellulose Acylate Film of the Present Invention]
In the evaluation of the cellulose acylate film of the present invention, measurement is carried out by the following method.

(In-plane retardation Re, thickness direction retardation Rth)
A sample 30 mm × 40 mm is conditioned at 25 ° C. and 60% RH for 2 hours. Re ₍ λ ₎ is an automatic birefringence meter KOBRA 21ADH (manufactured by Oji Scientific Instruments Co., Ltd.). Inject and measure. Rth ₍ λ ₎ is the Re ₍ λ ₎ and incident light having a wavelength of λ nm with the slow axis in the plane being the tilt axis and the film normal direction being 0 °, and the sample being tilted to 50 ° every 10 °. Based on the retardation value measured, the assumed average refractive index of 1.48 and the film thickness are input and calculated.

(Measurement of chromatic dispersion of Re and Rth)
A sample 30 mm × 40 mm was conditioned at 25 ° C. and 60% RH for 2 hours, and an ellipsometer M-150 (manufactured by JASCO Corporation) was used to make light of a wavelength of 780 nm to 380 nm incident in the normal direction of the film. Obtain Re at the wavelength and measure the wavelength dispersion of Re. Further, the wavelength dispersion of Rth was measured by making light having a wavelength of 780 to 380 nm incident from the direction inclined by + 40 ° with respect to the normal direction of the film with the slow axis in the plane as the tilt axis. Measured in three directions, the retardation value measured by making light with a wavelength of 780 to 380 nm incident from a direction tilted by −40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis Based on the retardation value, it is calculated by inputting the assumed average refractive index value of 1.48 and the film thickness.

(Molecular orientation axis)
The sample 70mm x 100mm was conditioned at 25 ° C and 65% RH for 2 hours, and the molecule was determined from the phase difference when the incident angle at normal incidence was changed with an automatic birefringence meter (KOBRA21DH, Oji Scientific Co., Ltd.). The orientation axis is calculated.
(Axis misalignment)
Moreover, the axis | shaft misalignment angle was measured with the automatic birefringence meter (KOBRA-21ADH, Oji Scientific Instruments). 20 points are measured at equal intervals over the entire width in the width direction, and the average value of absolute values is obtained. The range of the slow axis angle (axis deviation) is the measurement of 20 points at equal intervals over the entire width direction, and the difference between the average of the absolute value of the axis deviation and the average of the four points from the smaller absolute value. Is taken.

(Transmittance)
The transmittance of visible light (615 nm) is measured on a 20 mm × 70 mm sample at 25 ° C. and 60% RH with a transparency measuring instrument (AKA phototube colorimeter, KOTAKI Corporation).
(Spectral characteristics)
A sample 13 mm × 40 mm was measured for transmittance at a wavelength of 300 to 450 nm with a spectrophotometer (U-3210, Hitachi, Ltd.) at 25 ° C. and 60% RH. The inclination width was obtained at a wavelength of 72% -5%. The limit wavelength was expressed by a wavelength of (gradient width / 2) + 5%. The absorption edge is represented by a wavelength having a transmittance of 0.4%. From this, the transmittances at 380 nm and 350 nm are evaluated.

[Film surface properties]
The surface of the cellulose acylate film of the present invention has an arithmetic average roughness (Ra) of surface irregularities of the film based on JIS B0601-1994 of 0.1 μm or less and a maximum height (Ry) of 0.5 μm or less. preferable. Preferably, the arithmetic average roughness (Ra) is 0.05 μm or less, and the maximum height (Ry) is 0.2 μm or less. The concave and convex shapes on the film surface can be evaluated by an atomic force microscope (AFM).

[In-plane variation of retardation of cellulose acylate film]
The cellulose acylate film of the present invention preferably satisfies the following formula.
| Re _(MAX) −Re _(MIN) | ≦ 3 and | Rth _(MAX) −Rth _(MIN) | ≦ 5
[In the formula, Re _(MAX) and Rth _(MAX) − are the maximum retardation values of 1 m square film cut out arbitrarily, and Re _(MIN) and Rth _(MIN) are the minimum values. ]

[Retention of film]
In the cellulose acylate film of the present invention, retention of various compounds added to the film is required. Specifically, the mass change of the film when the cellulose acylate film of the present invention is allowed to stand for 48 hours under the condition of 80 ° C./90% RH is preferably 0 to 5%. More preferably, it is 0 to 3%, and still more preferably 0 to 2%.
<Reservation evaluation method>
The sample was cut to a size of 10 cm × 10 cm, and the mass after being allowed to stand for 24 hours in an atmosphere of 23 ° C. and 55% RH was measured, and left for 48 hours under the conditions of 80 ± 5 ° C. and 90 ± 10% RH. . The surface of the sample after the treatment is lightly wiped, the mass after standing for 1 day at 23 ° C. and 55% RH is measured, and the retention property is calculated by the following method.
Retention property (mass%) = {(mass before standing−mass after standing) / mass before standing} × 100

[Mechanical properties of film]
(curl)
The curl value in the width direction of the cellulose acylate film of the present invention is preferably −10 / m to + 10 / m. The cellulose acylate film of the present invention is subjected to surface treatment described later, rubbing treatment for coating an optically anisotropic layer, alignment film, coating and bonding of an optically anisotropic layer, etc. When the curl value in the width direction of the cellulose acylate film of the present invention is outside the above range, the handling of the film may be hindered and the film may be cut. In addition, the film is strongly in contact with the transport roll at the edge and center of the film, so it is easy to generate dust, and foreign matter adheres to the film. May exceed the value. Further, by setting the curl in the above-mentioned range, it is possible to reduce color spot failures that are likely to occur when the optically anisotropic layer is installed, and it is possible to prevent bubbles from entering when the polarizing film is bonded, which is preferable.
The curl value can be measured according to a measurement method (ANSI / ASCPH1.29-1985) defined by the American National Standards Institute.

(Tear strength)
The tear strength (Elmendorf tear method) based on the tear test method of JISK7128-2: 1998 is preferably 2 g or more when the film thickness of the cellulose acylate film of the present invention is in the range of 20 to 80 μm. More preferably, it is 5-25g, Furthermore, it is 6-25g. Moreover, 8 g or more is preferable at 60 micrometer conversion, More preferably, it is 8-15g. Specifically, it can be measured using a light load tear strength tester after conditioning a sample piece of 50 mm × 64 mm under the conditions of 25 ° C. and 65% RH for 2 hours.

[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 probably because free deposition is reduced by reducing the amount of residual solvent during film formation by the above-described solvent casting method.

[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. The hygroscopic expansion coefficient is preferably small, but usually it is 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 in a low-pressure gas of 10 ^{−3 to} 20 Torr, and plasma treatment under atmospheric pressure is also preferable. A plasma-excitable gas is a gas that is plasma-excited under the above conditions, and includes 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 in pages 30 to 32 of the Invention Association Public Technical Bulletin No. 2001-1745 (issued on March 15, 2001, Invention Association), and preferably used in the present invention. be able to.

[Contact angle of film surface by alkali saponification]
Alkali saponification is one effective means of surface treatment when the cellulose acylate film of the present invention is used as a transparent protective film for a polarizing plate. In this case, the contact angle on the film surface after the alkali saponification treatment is preferably 55 ° or less. More preferably, it is 50 ° or less, and more preferably 45 ° or less. The contact angle evaluation method can be used as an evaluation of hydrophilicity / hydrophobicity by an ordinary method in which a water droplet having a diameter of 3 mm is dropped on the surface of the film after the alkali saponification treatment and the angle formed by the film surface and the water droplet is determined.

(Light resistance)
As an index of light durability of the cellulose acylate of the present invention, it is preferable that the color difference ΔE * ab of the film irradiated with super xenon light for 240 hours is 20 or less. More preferably, it is 18 or less, and more preferably 15 or less. For the measurement of the color difference, UV3100 (manufactured by Shimadzu Corporation) was used. The measurement is carried out by adjusting the film to 25 ° C. and 60% RH for 2 hours or more, and then measuring the color of the film before irradiation with xenon light to determine initial values (L0 ^* , a0 ^* , b0 ^* ). Thereafter, the film alone is irradiated with xenon light for 240 hours under conditions of 150 W / m ² , 60 ° C. and 50% RH with Super Xenon Weather Meter SX-75 (manufactured by Suga Test Instruments Co., Ltd.). After the elapse of a predetermined time, the film is taken out from the thermostat, adjusted to 25 ° C. and 60% RH for 2 hours, and then subjected to color measurement again to obtain values after irradiation (L1 ^* , a1 ^* , b1 ^* ). From these, the color difference ΔE ^* ab = ((L0 ^* −L1 ^* ) ^ 2+ (a0 ^* −a1 ^* ) ^ 2+ (b0 ^* −b1 ^* ) ^ 2) ^ 0.5 is obtained.

[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. They 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. 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. Technique No. 2001-1745 (issued on March 15, 2001, Invention Association) is described in detail on 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 for bonding 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 is further constructed by laminating a protective film on one surface of the polarizing plate and a separate film on the opposite 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 outermost surface of the display side of the liquid crystal display device is provided with a transparent hard coat layer, an antiglare layer, an antireflection 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, refers to an optical material that compensates for a phase difference, and is synonymous with a phase difference 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. The cellulose acylate film of the present invention has small optical anisotropy with Re and Rth of 0 ≦ Re ₍₆₃₀₎ ≦ 10 nm and | Rth ₍₆₃₀₎ | ≦ 25 nm, and | Re ₍₄₀₀₎ −Re ₍₇₀₀₎ | ≦ 10 and | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ | ≦ 35 and the wavelength dispersion is small, so that no additional anisotropy occurs, and if an optically anisotropic layer having birefringence is used in combination, the optical properties of the optically anisotropic layer are reduced. Only performance can be expressed.

Therefore, when the cellulose acylate film of the present invention is used as an optical compensation film of a liquid crystal display device, Re and Rth of the optically anisotropic layer used together are Re ₍₆₃₀₎ = 0 to 350 nm and | Rth ₍₆₃₀₎ | = 0. The thickness is preferably 400 nm, and any optically anisotropic layer may be used within this range. The optical performance and driving method of the liquid crystal cell of the liquid crystal display device in which the cellulose acylate film of the present invention is used are not limited, and any optical anisotropic layer required as an optical compensation film can be used in combination. . The optically anisotropic layer used in combination may be formed from a composition containing a liquid crystalline compound or may be formed from a polymer film having birefringence.
In the optical compensation film of the present invention, as the optically anisotropic layer used in combination, a cyclic polyolefin film satisfying 35 ≦ Re ₍₆₃₀₎ ≦ 350 and 70 ≦ Rth ₍₆₃₀₎ ≦ 400, which is a polymer film having birefringence. Formed from. More preferably, it is formed from a cyclic polyolefin film that satisfies 35 ≦ Re ₍₆₃₀₎ ≦ 300 and 100 ≦ Rth ₍₆₃₀₎ ≦ 350. More preferably, it is formed from 35 ≦ Re ₍₆₃₀₎ ≦ 250 and 100 ≦ Rth ₍₆₃₀₎ ≦ 300.
The liquid crystalline compound is preferably a discotic liquid crystalline compound or a rod-shaped liquid crystalline compound.

(Discotic liquid crystalline compounds)
Examples of discotic liquid crystalline compounds that can be used in the optically anisotropic layer include various documents (C. Destrade et al., Mol. Crysr. Liq. Cryst., Vol. 71, page 111 (1981); Japan). Chemistry Association, Quarterly Review, No. 22, Liquid Crystal Chemistry, Chapter 5, Chapter 10 Section 2 (1994); B. Kohne et al., Angew. Chem. Soc. Chem. Comm., Page 1794. (1985); J. Zhang et al., J. Am. Chem. Soc., Vol. 116, page 2655 (1994)).

  In the optically anisotropic layer, the discotic liquid crystalline molecules are preferably fixed in an aligned state, and most preferably fixed by a polymerization reaction. The polymerization of discotic liquid crystalline molecules is described in JP-A-8-27284. In order to fix the discotic liquid crystalline molecules by polymerization, it is necessary to bond a polymerizable group as a substituent to the discotic core of the discotic liquid crystalline molecules. However, when the polymerizable group is directly connected to the disc-shaped core, it becomes difficult to maintain the orientation state in the polymerization reaction. Therefore, a linking group is introduced between the discotic core and the polymerizable group. JP-A-2001-4387 discloses a discotic liquid crystalline molecule having a polymerizable group.

(Bar-shaped liquid crystalline compound)
Examples of rod-like liquid crystalline compounds that can be used in the optically anisotropic layer include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, Cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are included. Not only the above low-molecular liquid crystalline compounds but also high-molecular liquid crystalline compounds can be used.

  In the optically anisotropic layer, the rod-like liquid crystalline molecules are preferably fixed in an aligned state, and most preferably fixed by a polymerization reaction. Examples of polymerizable rod-like liquid crystalline compounds that can be used in the present invention include Makromol. Chem. 190, 2255 (1989), Advanced Materials 5, 107 (1993), US Pat. Nos. 4,683,327, 5,622,648 and 5,770,107, International Publication No. 95/22586. Pamphlet, pamphlet of 95/24455, pamphlet of 97/00600, pamphlet of 98/23580, pamphlet of 98/52905, JP-A-1-272551, JP-A-6-16616, 7-110469 And the compounds described in JP-A-11-80081, JP-A-2001-328773, and the like.

(Optically anisotropic layer made of polymer film)
As described above, the optically anisotropic layer may be formed from a polymer film. The polymer film is formed from a polymer that can exhibit optical anisotropy. Examples of such polymers include polyolefins (eg, polyethylene, polypropylene, norbornene polymers), polycarbonates, polyarylate, polysulfone, polyvinyl alcohol, polymethacrylic acid esters, polyacrylic acid esters and cellulose esters (eg, cellulose triacetate, Cellulose diacetate). Further, a copolymer or a polymer mixture of these polymers may be used.
In the optical compensation film of the present invention, the optically anisotropic layer is formed from a cyclic polyolefin film satisfying 35 ≦ Re ₍₆₃₀₎ ≦ 350 and 70 ≦ Rth ₍₆₃₀₎ ≦ 400.

  The optical anisotropy of the polymer film is preferably obtained by stretching. The stretching is preferably uniaxial stretching or biaxial stretching. Specifically, longitudinal uniaxial stretching using a difference in peripheral speed between two or more rolls, tenter stretching for grasping both sides of the polymer film and stretching in the width direction, or biaxial stretching in combination of these is preferable. In addition, using two or more polymer films, the optical properties of the entire two or more films may satisfy the above conditions. The polymer film is preferably produced by a solvent cast method in order to reduce unevenness in birefringence. The thickness of the polymer film is preferably 20 to 500 μm, and most preferably 40 to 100 μm.

  Further, as the polymer film forming the optically anisotropic layer, at least one polymer material selected from the group consisting of polyamide, polyimide, polyester, polyetherketone, polyamideimide polyesterimide, and polyaryletherketone is used. A method in which a solution in which is dissolved in a solvent is applied to a substrate and the solvent is dried to form a film can also be preferably used. At this time, a method of stretching the polymer film and the base material to develop optical anisotropy and using it as an optical anisotropic layer can also be preferably used. The cellulose acylate film of the invention is preferably used as the base material. Can be used. In addition, the polymer film is prepared on another substrate, and after the polymer film is peeled off from the substrate, it is bonded to the cellulose acylate film of the present invention and used as an optically anisotropic layer. It is also preferable. In this method, the thickness of the polymer film can be reduced, and is preferably 50 μm or less, and more preferably 1 to 20 μm.

(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 Liquid BTS). 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 device)
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 in 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 a single 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 in parallel with the substrate surface in the absence of applied 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 optical anisotropic layer, the optical properties of the support, and the optical 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 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 reflective liquid crystal display device is described in Japanese Patent Application Laid-Open No. 10-123478, International Publication No. 98/48320, and Japanese Patent No. 3022477. The optical compensation sheet used in the reflective liquid crystal display device is described in International Publication No. 00/65384 pamphlet.

(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 in an ASM (axially aligned 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 Society of Invention and Innovation Technical Bulletin No. 2001-1745 (issued 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 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 driving liquid crystals. 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 surface of the cellulose acylate film of the present invention, or a relatively gas barrier property such as vinylidene chloride polymer or 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 properties, and an indium oxide thin film mainly containing 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.

Examples of the present invention will be given below, but the present invention is not limited thereto.
[Film Formation Example 1] (Creation of cyclic polyolefin film F-1)

<Synthesis of Cyclic Polyolefin Polymer P-1>
100 parts by mass of purified toluene and 100 parts by mass of norbornene carboxylic acid methyl ester were charged into a reaction kettle. Next, ethylhexanoate-Ni 25 mmol% (based on monomer mass) dissolved in toluene, tri (pentafluorophenyl) boron 0.225 mol% (based on monomer mass), and triethylaluminum 0.25 mol% (based on monomer mass) dissolved in toluene ) Was charged into the reaction kettle. The reaction was allowed to proceed for 18 hours at room temperature with stirring. After completion of the reaction, the reaction mixture was put into excess ethanol to form a copolymer precipitate. The copolymer (P-1) obtained by purifying the precipitate was vacuum dried at 65 ° C. for 24 hours.

The following composition was put into a mixing tank, stirred to dissolve each component, and then filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm.
――――――――――――――――――――――――――――――――
Cyclic polyolefin solution D-1
――――――――――――――――――――――――――――――――
Cyclic polyolefin P-1 150 parts by mass Methylene chloride 380 parts by mass Methanol 70 parts by mass ―――――――――――――――――――――――――――――――

Next, the following composition containing the cyclic polyolefin solution D-1 prepared by the above method was charged into a disperser to prepare a mat agent dispersion M-1.
――――――――――――――――――――――――――――――――
Matting agent dispersion M-1
――――――――――――――――――――――――――――――――
Silica particles having an average particle diameter of 16 nm (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) 2 parts by mass Methylene chloride 73 parts by mass Methanol 10 parts by mass Cyclic polyolefin solution D-1 10 parts by mass ――――――――――――― ―――――――――――――――――――
100 parts by mass of the cyclic polyolefin solution D-1 and 1.35 parts by mass of the matting agent dispersion M-1 were mixed to prepare a dope for film formation.
The above dope was cast using a band casting machine. A film peeled off from the band at a residual solvent amount of about 25% by mass was stretched in the width direction at a stretch rate of 10% using a tenter, and kept from 130 ° C. to 140 ° C. while keeping the film from wrinkling. Dry by applying hot air of ℃. Thereafter, the tenter transport was shifted to the roll transport, and further dried at 120 to 140 ° C. and wound up. The resulting cyclic polyolefin film (F-1) had a thickness of 80 μm, a haze of 0.5, a Re retardation of 63 nm, and an Rth retardation of 200 nm.

[Film Formation Example 2] (Creation of cyclic polyolefin film F-2)
The following composition was placed in a pressure-resistant sealed tank and stirred, and then heated to 80 ° C. with warm water to dissolve each component. After cooling, the mixture was filtered through a filter paper having an average pore diameter of 34 μm and a sintered metal filter having an average pore diameter of 10 μm.
――――――――――――――――――――――――――――――――
Cyclic polyolefin solution D-2
――――――――――――――――――――――――――――――――
Topas 5013 150 parts by mass (Distributor Polyplastics Corporation)
600 parts by mass of hexane ――――――――――――――――――――――――――――――――

Next, the following composition containing the cyclic polyolefin solution D-2 prepared by the above method was charged into a disperser to prepare a matting agent dispersion M-2.
――――――――――――――――――――――――――――――――
Matting agent dispersion M-2
――――――――――――――――――――――――――――――――
Silica particles having an average particle diameter of 16 nm (aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) 2 parts by mass hexane 80 parts by mass cyclic polyolefin solution D-2 10 parts by mass --------- ――――――――――――――
100 parts by mass of the above cyclic polyolefin solution D-2 and 1.1 parts by mass of the matting agent dispersion M-2 were mixed to prepare a dope for film formation.
The above dope was cast using a band casting machine. A film peeled off from the band with a residual solvent amount of about 18% by mass was stretched in the width direction at a stretch rate of 50% using a tenter and kept hot so as not to cause wrinkles. -140 ° C) and dried. Thereafter, the tenter transport was shifted to the roll transport, and further dried at 120 to 140 ° C. and wound up. The resulting cyclic polyolefin film (F-2) had a thickness of 80 μm, a haze of 0.4, a Re retardation of 60 nm, and an Rth retardation of 180 nm.

[Film Formation Example 3] (Creation of cyclic polyolefin film F-3)
The following composition was put into a mixing tank, stirred to dissolve each component, and then filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm.
――――――――――――――――――――――――――――――――
Cyclic polyolefin solution D-3
――――――――――――――――――――――――――――――――
Arton G (manufactured by JSR Corporation) 150 parts by weight hexane 600 parts by weight ――――――――――――――――――――――――――――――――

Next, the following composition containing the cyclic polyolefin solution D-3 prepared by the above method was charged into a disperser to prepare a mat agent dispersion M-3.
――――――――――――――――――――――――――――――――
Matting agent dispersion M-3
――――――――――――――――――――――――――――――――
Silica particles having an average particle diameter of 16 nm (aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) 2 parts by mass hexane 80 parts by mass cyclic polyolefin solution D-3 10 parts by mass --------- ――――――――――――――
100 parts by mass of the cyclic polyolefin solution D-3 and 1.1 parts by mass of the matting agent dispersion M-3 were mixed to prepare a dope for film formation.
The above dope was cast using a band casting machine. A film peeled off from the band with a residual solvent amount of about 22% by mass was stretched in the width direction at a stretch rate of 2% using a tenter, and kept hot so that wrinkles did not enter the film (130 ° C. To 140 ° C.) and dried. Thereafter, the tenter transport was shifted to the roll transport, and further dried at 120 to 140 ° C. and wound up. The resulting cyclic polyolefin film (F-3) had a thickness of 80 μm, a haze of 0.2, a Re retardation of 60 nm, and an Rth retardation of 190 nm.

[Film Formation Example 4] (Production of Cellulose Acylate Film 001 to 003, 101 to 104)

(Preparation of cellulose acetate solution)
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acetate solution D.

(Cellulose acetate solution D composition)
Cellulose acetate having an acetylation degree of 2.86 100.0 parts by mass Methylene chloride (first solvent) 402.0 parts by mass Methanol (second solvent) 60.0 parts by mass

(Preparation of matting agent solution)
20 parts by mass of silica particles having an average particle diameter of 16 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) and 80 parts by mass of methanol were mixed well for 30 minutes to obtain a silica particle dispersion. This dispersion was put into a disperser together with the following composition, and further stirred for 30 minutes or more to dissolve each component to prepare a matting agent solution.

(Matting agent solution composition)
Silica particle dispersion liquid having an average particle diameter of 16 nm 10.0 parts by mass Methylene chloride (first solvent) 76.3 parts by mass Methanol (second solvent) 3.4 parts by mass Cellulose acetate solution D 10.3 parts by mass

(Preparation of additive solution)
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare an additive solution.

(Additive solution composition)
Compound A-19 that lowers optical anisotropy 49.3 parts by mass Wavelength dispersion modifier UV-102 7.6 parts by mass Methylene chloride (first solvent) 58.4 parts by mass Methanol (second solvent) 8.7 Parts by weight cellulose acetate solution D 12.8 parts by weight

(Preparation of Cellulose Acetate Film Sample 101)
94.6 parts by mass of the cellulose acetate solution D, 1.3 parts by mass of the matting agent solution, and 4.1 parts by mass of the additive solution were mixed after filtration, and cast using a band casting machine. The mass ratios of Compound A-19 and wavelength dispersion modifier UV-102, which reduce optical anisotropy with the above composition, to cellulose acetate were 12% and 1.8%, respectively. The film was peeled from the band with a residual solvent amount of 30% and dried at 140 ° C. for 40 minutes to produce a cellulose acetate film. The resulting cellulose acetate film had a residual solvent amount of 0.2% and a film thickness of 80 μm.

(Production of cellulose acetate film samples 001 to 003 and 102 to 104)
Cellulose acetate film samples 001 to 003 and 102 to 104 were prepared in the same manner except that the types and amounts of the compound that reduces the optical anisotropy in the additive solution and the wavelength dispersion adjusting agent were changed to those shown in Table 1. . In Table 1, the solution composition for preparing Sample 101 is also entered.

When the difference ΔRth (= Rth10% RH−Rth80% RH) in the film thickness direction between the relative humidity of 10% and the relative humidity of 80% was measured, no optical anisotropy reducing agent was added. In Comparative Samples 001 and 002 and Comparative Sample 003 to which the plasticizer biphenyldiphenyl phosphate (BDP) was added instead of the optical anisotropy reducing agent, ΔRth did not become 30 nm or less, and the humidity dependence of optical anisotropy was large. It was.
On the other hand, in the sample 101 containing the optical anisotropy reducing agent, ΔRth was in the range of 0 to 30 nm, and it was confirmed that the humidity dependency was reduced. Further, when the equilibrium water content at 25 ° C. and 80% RH of these samples was measured, all of them were 4% or less except for the comparative sample 001, and the cellulose acylate film was obtained by adding an optical anisotropy reducing agent or a wavelength dispersion adjusting agent. It was confirmed that was hydrophobized. Furthermore, when 60 ° C., 95% RH, and 24 hr moisture permeability (in terms of 80 μm) of these samples were measured, all of them were 400 g / m ² · 24 hr or more and 2000 g / m ² · 24 hr or less except for the comparative sample 001. It was confirmed that the samples 101 to 103 to which the optical anisotropy reducing agent and the wavelength dispersion adjusting agent were added compared with the comparative samples 002 and 003 all had improved moisture permeability.

  Table 2 shows the evaluation results of optical properties of the obtained cellulose acylate film samples 101 to 104 and comparative samples 001 to 003.

Samples 101 to 104 using compounds that reduce optical anisotropy use comparative samples 001 to 002 that do not use these compounds and biphenyl-diphenyl phosphate (BDP), which is a general plasticizer. Compared with the comparative sample 003, both Re ₍₆₃₀₎ and Rth ₍₆₃₀₎ are sufficiently lowered, and are nearly optically isotropic. In addition, the samples using the compound that adjusts the chromatic dispersion are sufficiently reduced in both | Re ₍₄₀₀₎ −Re ₍₇₀₀₎ | and | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ | As seen, the chromatic dispersion is approaching zero.

[Example 1]
A configuration example of the present invention when mounted on a liquid crystal display device is shown in FIGS. Film A is a commercially available cellulose acetate film, Film B is a cellulose acetate film of Samples 101 to 104 of Film Formation Example 4, PVA is the following polarizing film, and Film C is a cyclic polyolefin film formed in Film Formation Examples 1 to 3. pointing.
In this embodiment, a VA type liquid crystal cell is used. However, the use of the polarizing plate or the optical compensation film using the film of the present invention and the configuration thereof is not limited to the operation mode of the liquid crystal display device.

(Preparation of polarizing plate)
The cellulose acetate film sample 101 obtained in Example 4 and a commercially available cellulose acetate film (TF80UL, 80 μm) were immersed in a 1.5 N aqueous sodium hydroxide solution at 55 ° C. for 2 minutes. It wash | cleaned in the room temperature water-washing tub, and neutralized using 0.1 N sulfuric acid at 30 degreeC. Again, it was washed in a water bath at room temperature and further dried with hot air at 100 ° C. In this way, the surface of the cellulose acylate film was saponified.
Subsequently, a roll-shaped polyvinyl alcohol film having a thickness of 80 μm was continuously stretched 5 times in an iodine aqueous solution and dried to obtain a polarizing film. Using a 3% aqueous solution of polyvinyl alcohol (Kuraray PVA-117H) as an adhesive, alkali saponified cellulose acylate film sample 101 and TF80UL were prepared and bonded together with a polarizing film in between, and one side was cellulose acylate film 101 A polarizing plate having the other surface protected by TF80UL was obtained. At this time, the films were attached so that the slow axis of each film was parallel to the transmission axis of the polarizing film.
Attach the cyclic polyolefin film F-1 obtained in Example 1 to the cellulose acetate film sample 101 side of this polarizing plate via an adhesive so that its slow axis is parallel to the transmission axis of the polarizing film. A polarizing plate was created.
Next, a polarizing plate prepared using a commercially available cellulose acetate film (TF80UL: 80 μm) on both sides of the polarizing film in the same manner was used as the lower polarizing plate.

(Production of VA liquid crystal cell and liquid crystal display device)
The liquid crystal cell has a cell gap between substrates of 3.6 μm, and a liquid crystal material having negative dielectric anisotropy (“MLC6608”, manufactured by Merck & Co., Inc.) is dropped and sealed between the substrates. Prepared by forming a layer. The retardation of the liquid crystal layer (that is, the product Δn · d of the thickness d (μm) of the liquid crystal layer and the refractive index anisotropy Δn) was set to 300 nm. The liquid crystal material was aligned so as to be vertically aligned. On the upper side (observer side) of the vertical alignment type liquid crystal cell, a cyclic polyolefin film F-1 of the prepared upper polarizing plate was attached via an adhesive so as to be on the liquid crystal cell side. The prepared lower polarizing plate was attached to the lower side (backlight side) of the liquid crystal cell via an adhesive. A crossed Nicol arrangement was adopted so that the transmission axis of the upper polarizing plate was in the vertical direction and the transmission axis of the lower polarizing plate was in the horizontal direction (Configuration 101 in FIG. 1).

As a result of observing the manufactured liquid crystal display device, a neutral black display was realized in the front direction and the viewing angle direction. In addition, using a measuring instrument (EZ-Contrast 160D, manufactured by ELDIM), the viewing angle (contrast ratio is 10 or more and there is no gradation inversion on the black side) in eight stages from black display (L1) to white display (L8). As a result of measuring (range), the viewing angle was 80 degrees or more in both the left, right, top and bottom.
In addition, even if this liquid crystal panel is subjected to environmental humidity changes (10% RH, 80% RH) for 1 week, the color of the black display is almost the same as that measured at 60% RH for both viewing angles. The deterioration of liquid crystal display quality was not so much observed due to environmental humidity change.
The same results were obtained when cyclic polyolefin films F-2 and F-3 were used instead of cyclic polyolefin film F-1, but when 102 to 104 were used instead of cellulose acetate film sample 101. In any case of F-1, F-2, and F-3, the deterioration of the liquid crystal display quality due to the environmental humidity change was smaller in 102 than 102, 103 rather than 102, and 104 rather than 103. This suggests that the smaller the Rth humidity change, the smaller the degradation of display quality when the environmental humidity of the liquid crystal display panel is changed.

[Comparative Example 1]
In Example 1, the same procedure as in Example 1 was performed except that a commercially available cellulose acetate film (TF80UL: 80 μm) was used instead of the cellulose acetate film sample 101 of the upper polarizing plate, and the configuration 001 of FIG. 2 was obtained.
The black display in the front direction and the viewing angle direction of the obtained liquid crystal display device was slightly bluish. The viewing angle characteristics were good viewing angles of 80 degrees or more in both the left, right, top and bottom.
In addition, after changing the environmental humidity of the liquid crystal panel (10% RH, 80% RH) for 1 week, the color of the black display is further bluish, and the deterioration of the liquid crystal display quality is recognized due to the environmental humidity change. It was.

  As can be seen from Example 1 and Comparative Example 1 described above, even when the cyclic polyolefin film F-1 and the cellulose acetate film sample 101 with little change in optical properties due to changes in environmental humidity are used, there is a gap between the two polarizing films. In addition, if there is a single film that is susceptible to environmental humidity changes (such as a commercially available cellulose acetate film) and has a phase difference (Re, Rth) that is not zero, the display quality is degraded due to environmental humidity fluctuations. Will be invited.

[Example 2]
In Example 1, except that the upper polarizing plate was disposed on the lower side (backlight side), and the lower polarizing plate was disposed on the upper side (observer side), the configuration 201 in FIG. Obtained.
As a result of observing the manufactured liquid crystal display device, a neutral black display was realized in the front direction and the viewing angle direction. Moreover, as a result of measuring the viewing angle (the range in which the contrast ratio is 10 or more and there is no black-side gradation inversion) using a measuring machine, the viewing angle is 80 degrees or more in both the left, right, top and bottom.
In addition, even if this liquid crystal panel is subjected to environmental humidity changes (10% RH, 80% RH) for 1 week, the color of the black display is almost the same as that measured at 60% RH for both viewing angles. The deterioration of liquid crystal display quality was not so much observed due to environmental humidity change.

[Comparative Example 2]
Example 2 was performed in exactly the same way as Example 2 except that a commercially available cellulose acetate film (TF80UL: 80 μm) was used instead of the cellulose acetate film sample 101 of the lower polarizing plate, and the structure 002 of FIG. 2 was obtained.
The black display in the front direction and the viewing angle direction of the obtained liquid crystal display device was slightly bluish. The viewing angle characteristics were good viewing angles of 80 degrees or more in both the left, right, top and bottom.
In addition, after changing the environmental humidity of the liquid crystal panel (10% RH, 80% RH) for 1 week, the color of the black display is further bluish, and the deterioration of the liquid crystal display quality is recognized due to the environmental humidity change. It was.

  As can be seen from Examples 1 and 2 and Comparative Examples 1 and 2 described above, even when the cyclic polyolefin film F-1 and the cellulose acetate film sample 101 with little change in optical properties due to environmental humidity change are used, A film having a phase difference (Re, Rth) that is not subject to zero (such as a commercially available cellulose acetate film) and having a non-zero phase difference (such as a commercially available cellulose acetate film) is 1 regardless of whether it is above or below the liquid crystal cell. If there are too many sheets, the display quality will deteriorate due to environmental humidity fluctuations.

[Example 3]
The configurations 102 to 108 and the configurations 202 to 208 in FIG. 1 were also created by the same creation method as in the first and second embodiments, and the viewing angle and the color of black display were observed. The liquid crystal display quality was not significantly reduced even when the display quality was good and the environmental humidity was changed.

[Example 4]
The configurations 109 to 113 and configurations 209 to 213 in FIGS. 1 and 2 were also created by the same creation method as in Examples 1 to 3, and the viewing angle of the obtained liquid crystal display device and the color of black display were observed. The same results as in Examples 1 to 3 were obtained, and good display quality was obtained. Further, the deterioration of the liquid crystal display quality with respect to the environmental humidity change was better than that of Examples 1 to 3, and was a very slight change.

  This is an environment (such as a commercially available cellulose acetate film) between the two polarizing films even when the cyclic polyolefin film F-1 and the cellulose acetate film sample 101 with little optical property change due to environmental humidity change are used. Since there is no film that is susceptible to humidity changes and has a non-zero phase difference (Re, Rth) regardless of whether it is above or below the liquid crystal cell, there is almost no deterioration in display quality due to environmental humidity fluctuations. It is thought that.

[Example 5]
Configurations 114 to 118 and configurations 214 to 218 in FIG. 2 were performed in the same manner as in Examples 1 to 4. However, the lamination of the polarizing film of the upper polarizing plate of the configuration 114 to 118 and the lower polarizing plate of the configuration 214 to 218 and the cyclic polyolefin film C of Example 5 is performed with the cyclic polyolefin films F-1, F-2, F- 3 was subjected to glow discharge treatment (high frequency voltage of 3000 Hz, 4200 V applied between upper and lower electrodes, treatment for 20 seconds), and then the polarizing film was dried at 70 ° C. for 10 minutes or more using a polyvinyl alcohol adhesive. .
When the viewing angle of the obtained liquid crystal display device and the color of black display were observed, the same results as in Example 4 were obtained, and good display quality was obtained. Moreover, it was substantially equivalent to Example 4 with respect to environmental humidity change.
In this embodiment, the number of films provided for the liquid crystal display device can be reduced, leading to cost reduction, and the thickness of the liquid crystal display device can be reduced.

It is a figure which shows the structural example of the liquid crystal display device of this invention. It is a figure which shows the structural example of the liquid crystal display device of this invention and a comparative example.

Claims (13)

An optical compensation film comprising a cyclic polyolefin film satisfying the following formula (I) and a cellulose acylate film satisfying the following formulas (II) and (III).
(I) 35 ≦ Re ₍₆₃₀₎ ≦ 350 and 70 ≦ Rth ₍₆₃₀₎ ≦ 400
(II) 0 ≦ Re ₍₆₃₀₎ ≦ 10 and | Rth ₍₆₃₀₎ | ≦ 25
(III) | Re ₍₄₀₀₎ −Re ₍₇₀₀₎ | ≦ 10 and | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ | ≦ 35
[Re ₍ λ ₎ represents the front retardation value (unit: nm) at the wavelength λnm, and Rth ₍ λ ₎ represents the retardation value (unit: nm) in the film thickness direction at the wavelength λnm. ] At least one sheet of a cyclic polyolefin film satisfying the following formula (I) and a cellulose acylate film satisfying the following formulas (II) and (III) are included between two polarizing films of the liquid crystal display device. Liquid crystal display device.
(I) 35 ≦ Re ₍₆₃₀₎ ≦ 350 and 70 ≦ Rth ₍₆₃₀₎ ≦ 400
(II) 0 ≦ Re ₍₆₃₀₎ ≦ 10 and | Rth ₍₆₃₀₎ | ≦ 25
(III) | Re ₍₄₀₀₎ −Re ₍₇₀₀₎ | ≦ 10 and | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ | ≦ 35
[Re ₍ λ ₎ represents the front retardation value (unit: nm) at the wavelength λnm, and Rth ₍ λ ₎ represents the retardation value (unit: nm) in the film thickness direction at the wavelength λnm. ] The cyclic polyolefin film is composed of a copolymer comprising at least one repeating unit represented by the general formula (A) and at least one cyclic repeating unit represented by the general formula (B). The optical compensation film according to claim 1 or the liquid crystal display device according to claim 2.

In the formula, m represents an integer of 0 to 4. R ^{1 to} R ⁴ are a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, X ^{1 to} X ² , and Y ^{1 to} Y ² are a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, and a halogen atom. substituted hydrocarbon group having 1 to 10 carbon _{atoms, - (CH 2) n COOR} 11, - (CH 2) n OOCR 12, - (CH 2) n NCO, - (CH 2) n NO 2, - ( CH ₂ ) _n CN, — (CH ₂ ) _n CONR ¹³ R ¹⁴ , — (CH ₂ ) _n NR ¹³ R ¹⁴ , — (CH ₂ ) _n OCOZ, — (CH ₂ ) _n OZ, — (CH ₂ ) _n W, (—CO) ₂ O, (—CO) ₂ NR ¹⁵ composed of X ¹ and Y ¹ or X ² and Y ² are shown. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ are hydrocarbon groups having 1 to 20 carbon atoms, Z is a hydrocarbon group or a hydrocarbon group substituted with halogen, and W is SiR ¹⁶ _p D _{3− p} (R ¹⁶ is a hydrocarbon group having 1 to 10 carbon atoms, D is a halogen atom —OCOR ¹⁶ or —OR ¹⁶ , p is an integer of 0 to 3), and n is an integer of 0 to 10. The cyclic polyolefin film is a polymer comprising one type of cyclic repeating unit represented by general formulas (B) and (C), or at least two types of cyclic repeating represented by general formulas (B) and (C). 3. The optical compensation film according to claim 1, or the liquid crystal display device according to claim 2, wherein the optical compensation film is made of a copolymer comprising units.

In the formula, m represents an integer of 0 to 4. R ^{3 to} R ⁶ are hydrogen atoms or hydrocarbon groups having 1 to 10 carbon atoms, X ^{2 to} X ³ and Y ^{2 to} Y ³ are hydrogen atoms, hydrocarbon groups having 1 to 10 carbon atoms, halogen atoms, and halogen atoms. substituted hydrocarbon group having 1 to 10 carbon _{atoms, - (CH 2) n COOR} 11, - (CH 2) n OOCR 12, - (CH 2) n NCO, - (CH 2) n NO 2, - ( CH ₂ ) _n CN, — (CH ₂ ) _n CONR ¹³ R ¹⁴ , — (CH ₂ ) _n NR ¹³ R ¹⁴ , — (CH ₂ ) _n OCOZ, — (CH ₂ ) _n OZ, — (CH ₂ ) _n W, (—CO) ₂ O, (—CO) ₂ NR ¹⁵ composed of X ² and Y ² or X ³ and Y ³ are shown. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ are hydrocarbon groups having 1 to 20 carbon atoms, Z is a hydrocarbon group or a hydrocarbon group substituted with halogen, and W is SiR ¹⁶ _p D _{3− p} (R ¹⁶ is a hydrocarbon group having 1 to 10 carbon atoms, D is a halogen atom —OCOR ¹⁶ or —OR ¹⁶ , p is an integer of 0 to 3), and n is an integer of 0 to 10.   The cyclic polyolefin film is cast on an endless metal support with an organic solvent solution containing 10% to 35% by weight of the polymer or copolymer, dried, and then peeled off from the metal support. The optical compensation film according to claim 3 or 4, wherein the optical compensation film is formed by stretching in at least one of a width direction and a length direction, further drying and winding. 5. A liquid crystal display device according to 3 or 4. The cellulose acylate film contains at least one compound that lowers the retardation Rth in the film thickness direction within a range satisfying the following formulas (IV) and (V). 6. The optical compensation film according to claim 1, or the liquid crystal display device according to any one of claims 2 to 5.
(IV) (Rth (A) −Rth (0)) / A ≦ −1.0
(V) 0.01 ≦ A ≦ 30
here,
Rth (A): Rth (nm) of a film containing A% of a compound that lowers Rth
Rth (0): Rth (nm) of a film not containing a compound that lowers Rth
A: Mass (%) of the compound when the mass of the film raw material polymer is 100
It is.   7. The optical compensation film according to claim 1, wherein the cellulose acylate film is a cellulose acylate having an acyl substitution degree of 2.85 to 3.00. The liquid crystal display device in any one of -6. The cellulose acylate film contains at least one compound that lowers | Rth ₍₄₀₀₎ -Rth ₍₇₀₀₎ | in an amount of 0.01 to 30% by mass based on the solid content of cellulose acylate. The optical compensation film in any one of 1, 3-7, or the liquid crystal display device in any one of Claims 2-7.   The film thickness of the said cellulose acylate film is 10-120 micrometers, The optical compensation film in any one of Claims 1 and 3-8, or the liquid crystal in any one of Claims 2-8 Display device.   A polarizing plate comprising the optical compensation film according to claim 1 as at least one polarizer protective film.   The polarizing plate according to claim 10, wherein at least one layer of a hard coat layer, an antiglare layer, and an antireflection layer is provided on the surface.   A liquid crystal display device comprising the optical compensation film according to any one of claims 1 and 3 and the polarizing plate according to claim 10 or 11.   A VA or IPS liquid crystal display device comprising the optical compensation film according to any one of claims 1 and 3 and the polarizing plate according to claim 10 or 11.

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