JP2010078967A - Polarizing plate and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizing plate contributing to the reduction of reddish discoloration which occurs when driving a liquid crystal display device in a relatively low-temperature and high-humidity environment. <P>SOLUTION: The polarizing plate includes at least a polarizer, a first protection film disposed on one surface of the polarizer, and a second protection film disposed on the other surface of the polarizer, and the sum of water vapor permeability rates of the first protection film and the second protection film at 60°C and 95% RH is ≥1,500 g/m<SP>2</SP>×day. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polarizing plate useful for a liquid crystal display device and a liquid crystal display device including the polarizing plate.

In a polarizing plate used in a liquid crystal display device, a protective film (hereinafter sometimes referred to as a protective layer) is usually bonded to both surfaces of a polarizer having polarizing ability via an adhesive layer. Conventionally, it is known that when a polarizing plate is exposed to heat and humidity over a long period of time, the polarization performance fluctuates, and further, the display performance of the liquid crystal display device decreases. One of the causes is considered to be that moisture in the environment permeates into the polarizing plate, thereby changing the size of the polarizer. Therefore, conventionally, it was thought that the use of a polymer film having a low moisture permeability for the protective film contributes to improving the durability of the polarizing plate (for example, Patent Document 1).
JP 2008-107499 A

  On the other hand, liquid crystal display devices are used in various forms, and durability is required not only in high temperature and high humidity environments but also in various environments such as low temperature and high humidity environments. In the past, the inventor's investigation has revealed that most of the studies have been to improve the durability of polarizing plates in high-temperature and high-humidity environments, which may impair the durability in other environments. It was. Specifically, when the polarizing plate is used for a long time under a relatively low temperature of about 20 ° C. and in a high humidity environment, red discoloration may occur. It was found that this discoloration becomes more prominent when a polarizing plate having a low moisture permeability polymer film on the surface is used.

  Accordingly, the present invention provides a polarizing plate that contributes to reducing reddish discoloration that occurs in a liquid crystal display device by use in a relatively low temperature and high humidity environment, and a relatively low temperature and high humidity environment. It is an object of the present invention to provide a liquid crystal display device in which reddish discoloration caused by use in the liquid crystal display device is reduced.

Means for solving the above problems are as follows.
[1] At least a polarizer, a first protective film disposed on one surface of the polarizer, and a second protective film disposed on the other surface of the polarizer, the first protective film And a sum of moisture permeability at 60 ° C. and 95% RH of the second protective film is 1500 g / m ² · day or more.
[2] A liquid crystal display device having at least a polarizing plate and a liquid crystal cell, wherein the polarizing plate includes a polarizer, a first protective film disposed on one surface of the polarizer, and the polarizer. A second protective film disposed on the other surface of the first protective film, and a sum of moisture permeability at 60 ° C. and 95% RH of the first protective film and the second protective film is 1500 g / m ² · day or more. There is a liquid crystal display device.
[3] The first protective film is disposed outside and the second protective film is disposed on the liquid crystal cell side, and the moisture permeability at 60 ° C. and 95% RH of the first protective film is 400 g / m ² · day or more, and The liquid crystal display device according to [2], wherein the second protective film has a moisture permeability of 1000 g / m ² · day or more at 60 ° C. and 95% RH.

  ADVANTAGE OF THE INVENTION According to this invention, the polarizing plate which contributes to reducing the reddish discoloration which arises in a liquid crystal display device by use in a comparatively low temperature and high humidity environment, and a comparatively low temperature and high humidity environment. A liquid crystal display device in which reddish discoloration caused by use in the liquid crystal display device is reduced can be provided.

Hereinafter, the present invention will be described in detail. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
The present invention includes at least a polarizer, a first protective film disposed on one surface of the polarizer, and a second protective film disposed on the other surface of the polarizer, and the first protection. The present invention relates to a polarizing plate, wherein the sum of moisture permeability at 60 ° C. and 95% RH of the film and the second protective film is 1500 g / m ² · day or more. In the polarizing plate of the present invention, the sum of the water vapor transmission rates of the two polarizing plates is within the above range, so even if moisture in the environment permeates into the polarizing plate, Can escape. As a result, even when the liquid crystal display device having the polarizing plate of the present invention is used for a long period of time in a relatively low temperature (for example, about 20 ° C.) and high humidity (for example, 95% RH), moisture remains on the polarizing plate. It is possible to suppress the occurrence of reddish discoloration, which has been a problem in the past, without being retained for a long time.

In the present invention, the sum of moisture permeability at 60 ° C. and 95% RH of the first protective film and the second protective film is preferably 2000 g / m ² · day or more.
In this specification, moisture permeability is calculated according to JIS Z-0208, except that the humidity control condition is changed to 60 ° C. and 95% RH. When measuring the moisture permeability of a sample, repeat the operation of taking out and weighing the cup placed in a constant temperature and humidity device at an appropriate time interval, and obtaining the mass increase per unit time with two consecutive weighings. Continue the evaluation until it becomes constant within 5%. Moreover, in order to exclude the influence by moisture absorption etc. of a sample, the blank cup which does not put a hygroscopic agent is measured, and the value of moisture permeability is correct | amended. Moreover, when measuring the moisture permeability of the protective film having a resin layer containing a vinyl alcohol polymer, set the sample in such an orientation that the resin layer provided on the transparent substrate film is in contact with the measuring cup, The moisture permeability from the transparent base film side is measured by the same method as described above.

The first and second protective films may be made of the same polymer film, and in this embodiment, the first and second protective films are selected from polymer films having a moisture permeability of 750 g / m ² · day or more at 60 ° C. and 95% RH. The first and second protective films may be made of other polymer films. For example, the moisture permeability of the first protective film at 60 ° C. and 95% RH is 400 / m ² · day or more. The moisture permeability of the second protective film at 60 ° C. and 95% RH may be 1000 / m ² · day or more, and the sum may be a combination of 1500 g / m ² · day or more. When incorporating the polarizing plate of the said aspect into a liquid crystal display device, arrange | position the 1st protective film of high moisture permeability on the outer side, and arrange | position the 2nd protective film of low moisture permeability on the inner side (liquid crystal cell side). Is preferred.

1. 1st and 2nd protective film There is no restriction | limiting in particular about the polymer film utilized as a 1st and 2nd protective film of the polarizing plate of this invention. Various polymer films can be used as long as the combination of moisture permeability is within the above range. Specifically, polymer films mainly composed of various polymers such as cellulose acylate, polyester, polycarbonate, saturated alicyclic structure-containing polymer, acrylic polymer, melamine polymer, and polyethylene can be used. Especially, the polymer film which has a cellulose acylate or a saturated alicyclic structure containing polymer as a main component is preferable.

  Commercially available products may be used. For example, commercially available cellulose acylate films include TAC-TD80U and TD80UL manufactured by Fuji Film. In addition, as a commercially available norbornene-based resin film that can be used, there is Arton manufactured by JSR. Examples of the amorphous polyolefin film that can be used include ZEONEX manufactured by ZEON Corporation. Also, ARC270 manufactured by Nitto Denko Corporation can be used.

1. -1 Cellulose acylate film In this invention, it is preferable to use a cellulose acylate film as a 1st and / or 2nd protective film. The cellulose acylate that can be used as a material for forming the protective film in the present invention is substantially composed of cellulose acylate obtained by substituting the hydroxyl group of the glucose unit constituting cellulose with an acyl group having 2 or more carbon atoms. It is preferable that the film becomes. Here, “substantially” means 55 mass% or more (preferably 70 mass% or more, more preferably 80 mass% or more) of the polymer component.
Two or more different cellulose acylates may be mixed and used.

The cellulose acylate is a mixed fatty acid ester of cellulose obtained by substituting the hydroxyl group of cellulose with an acetyl group and an acyl group having 3 or more carbon atoms. ) And (XIV) may be used. A film produced using such cellulose acylate tends to have high optical anisotropy.
Formula (XIII): 2.0 ≦ A + B ≦ 3.0
Formula (XIV): 0 <B

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

As shown in the above formula (XIII), the total degree of substitution of hydroxyl groups A and B (A + B) is 2.0 to 3.0, preferably 2.2 to 2.9, particularly preferably. Is 2.40-2.85. Further, the substitution degree of B is preferably larger than 0, more preferably 0.6 or more, as shown in the above formula (XIV).
When A + B is less than 2.0, the hydrophilicity becomes strong and it is easy to be affected by environmental humidity.
Further, 28% or more of B is preferably a 6-position hydroxyl group substituent, more preferably 30% or more is a 6-position hydroxyl group substituent, more preferably 31% or more, and particularly preferably 32% or more. A substituent at the 6-position hydroxyl group is preferred.
Furthermore, the total substitution degree of A and B at the 6-position of cellulose acylate is preferably 0.75 or more, more preferably 0.80 or more, and particularly preferably 0.85 or more. With these cellulose acylate films, a solution for preparing a film having preferable solubility and filterability can be produced, and a good solution can be produced even in a non-chlorine organic solvent. Furthermore, it is possible to prepare a solution having a low viscosity and good filterability.

  In addition, the cellulose acylate film used as a protective film disposed on the liquid crystal cell side of the polarizing plate has a substitution degree of the hydroxyl group at the 2-position of the glucose unit constituting the cellulose with an acyl group of DS2, and the acyl group of the hydroxyl group at the 3-position. It is preferable that the following formulas (XI) and (XII) be satisfied, where DS is the substitution degree by DS3 and DS6 is the substitution degree by the acyl group of the hydroxyl group at the 6-position.

Formula (XI): 2.0 ≦ DS2 + DS3 + DS6 ≦ 3.0
Formula (XII): DS6 / (DS2 + DS3 + DS6) ≧ 0.315

By satisfy | filling said Formula (XI) and (XII), the solubility to a solvent improves and the humidity dependence of optical anisotropy can be made small.

In the case where the cellulose acylate film is substantially composed of cellulose acylate which is a mixed fatty acid ester of cellulose in which a hydroxyl group of cellulose is substituted with an acetyl group and an acyl group having 3 or more carbon atoms, The substitution degrees DS2A, DS3A, DS6A of the acetyl groups at the 2nd, 3rd, 6th positions and the substitution degrees DS2B, DS3B, DS6B of the acyl groups with 3 or more carbon atoms at the 2nd, 3rd, 6th positions are as follows: It is preferable that the numerical formula (XIII) is satisfied, and at least one of DS2B, DS3B, and DS6B is a positive value.
Formula (XIII): 2.0 ≦ DS2A + DS2B + DS3A + DS3B + DS6A + DS6B ≦ 3.0
Here, the substitution degree of the acetyl group of the cellulose acylate at the 2nd, 3rd and 6th positions and the substitution degree B of the acyl group having 3 or more carbon atoms satisfy the following formula (XIV). preferable.
Formula (XIV): (DS6A + DS6B) / (DS2A + DS2B + DS3A + DS3B + DS6A + DS6B) ≧ 0.315
By satisfy | filling said Formula (XIII) or (XIV), the solubility to a solvent improves and the humidity dependence of optical anisotropy can be made small.

  The acyl group (B) having 3 or more carbon atoms may be an aliphatic group or an aromatic hydrocarbon group, and is not particularly limited. For example, cellulose alkylcarbonyl ester, alkenylcarbonyl ester, aromatic carbonyl ester, aromatic alkyl A carbonyl ester and the like, each of which may further have a substituted group. These preferred B include propionyl, butanoyl, keptanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, iso-butanoyl, t-butanoyl, cyclohexanecarbonyl, oleoyl, benzoyl , Naphthylcarbonyl, cinnamoyl group, and the like. Among these, propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, oleoyl, benzoyl, naphthylcarbonyl, cinnamoyl group and the like are preferable. Particularly preferred are a propionyl group and a butanoyl group. In the case of a propionyl group, the substitution degree B is preferably 1.3 or more.

Specific examples of the mixed fatty acid cellulose acylate include cellulose acetate propionate and cellulose acetate butyrate.

  As the cellulose acylate, a cellulose acylate having a degree of acyl substitution with a hydroxyl group of cellulose of 2.50 to 3.00 may be used. A film produced using such cellulose acylate tends to have small optical anisotropy. Furthermore, the substitution degree is preferably 2.75 to 3.00, and more preferably 2.85 to 3.00.

  Among the acyl groups having 2 to 22 carbon atoms to be substituted for the hydroxyl group of cellulose, the acyl group having 2 to 22 carbon atoms may be an aliphatic group or an allyl group, and is not particularly limited. A single or a mixture of two or more types But you can. 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 the cellulose described above, when it is substantially composed of at least two of an acetyl group, a propionyl group, and a butanoyl group, the cellulose has a total substitution degree of 2.50 to 3.00. The optical anisotropy of the acylate film can be reduced, which is preferable. The degree of acyl substitution is more preferably 2.75 to 3.00, and even more preferably 2.85 to 3.00.

The basic principle of the cellulose acylate synthesis method is described in Mita et al., Wood Chemistry pages 180-190 (Kyoritsu Shuppan, 1968). A typical synthesis method is a liquid phase acetylation method using a carboxylic acid anhydride-acetic acid-sulfuric acid catalyst.
In order to obtain the cellulose acylate, specifically, a cellulose raw material such as cotton linter or wood pulp is pretreated with an appropriate amount of acetic acid, and then esterified by introducing it into a pre-cooled carboxylated mixed solution. Synthesize the rate (total of acyl substitution at the 2nd, 3rd and 6th positions is approximately 3.00). The carboxylated mixed solution generally contains acetic acid as a solvent, carboxylic anhydride as an esterifying agent, and sulfuric acid as a catalyst. The carboxylic anhydride is usually used in a stoichiometric excess over the sum of the cellulose that reacts with it and the water present in the system. After completion of the esterification reaction, a neutralizing agent (for example, calcium, magnesium, iron, aluminum or zinc) is used for hydrolysis of excess carboxylic anhydride remaining in the system and neutralization of a part of the esterification catalyst. Of carbonate, acetate or oxide). Next, the obtained complete cellulose acylate is saponified and aged by maintaining it at 50 to 90 ° C. in the presence of a small amount of an acetylation reaction catalyst (generally, remaining sulfuric acid) to obtain the desired degree of acyl substitution and polymerization. The cellulose acylate having a degree is changed. When the desired cellulose acylate is obtained, the catalyst remaining in the system is completely neutralized with a neutralizing agent as described above, or in water or dilute sulfuric acid without neutralization. The cellulose acylate solution is added (or water or dilute sulfuric acid is added to the cellulose acylate solution), the cellulose acylate is separated, washed and stabilized, etc. Can be obtained.

In the cellulose acylate film, it is preferable that the polymer component constituting the film is substantially composed of the specific cellulose acylate. “Substantially” means 55% by mass or more (preferably 70% by mass or more, more preferably 80% by mass or more) of the polymer component. The cellulose acylate is preferably used in the form of particles. 90% by mass or more of the particles to be used preferably have a particle diameter of 0.5 to 5 mm. Moreover, it is preferable that 50 mass% or more of the particle | grains to be used have a particle diameter of 1-4 mm. The cellulose acylate particles preferably have a shape as close to a sphere as possible.
The degree of polymerization of the cellulose acylate preferably used in the present invention is a viscosity average degree of polymerization, preferably 200 to 700, more preferably 250 to 550, still more preferably 250 to 400, and particularly preferably 250 to 350. . 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. 18, No. 1, pages 105-120, 1962). Further details are described in JP-A-9-95538.

When the low molecular component is removed, the average molecular weight (polymerization degree) is increased, but the viscosity is lower than that of ordinary cellulose acylate. Therefore, the cellulose acylate from which the low molecular component is removed 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 acylates. When the amount of the sulfuric acid catalyst is in 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 cellulose acylate, the water content is preferably 2% by mass or less, more preferably 1% by mass or less, and particularly 0.7% by mass or less. In general, cellulose acylate contains water and is known to have a water content of 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.
The cellulose acylate raw material cotton and the synthesis method thereof are disclosed in JIII Journal of Technical Disclosure No. 2001-1745 (issued March 15, 2001, Invention Association) p. Raw material cotton and synthesis methods described in detail in 7-12 can be employed.

  The cellulose acylate film used in the present invention can be obtained by forming a film using a solution obtained by dissolving the cellulose acylate and, if necessary, an additive in an organic solvent.

Examples of the additive that can be used in the cellulose acylate solution in the present invention include a plasticizer, an ultraviolet absorber, a deterioration preventing agent, a retardation (optical anisotropy) developing agent, and a retardation (optical anisotropy). Examples thereof include a reducing agent, a matting agent (fine particles), a peeling accelerator, and an infrared absorber. In the present invention, it is preferable to use a retardation developer. Moreover, it is preferable to use 1 or more types selected from a plasticizer, an ultraviolet absorber, a peeling accelerator, a dye and a matting agent.
They may be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, ultraviolet absorbers of 20 ° C. or lower and 20 ° C. or higher can be mixed and used, and plasticizers can also be mixed and used, for example, as described in JP-A No. 2001-151901.
As the ultraviolet absorber, any type can be selected according to the purpose, and a salicylic acid ester-based, benzophenone-based, benzotriazole-based, benzoate-based, cyanoacrylate-based, nickel complex-based absorber or the like is used. Preferred are benzophenone series, benzotriazole series, and salicylic acid ester series. Examples of benzophenone ultraviolet absorbers include 2,4-dihydroxybenzophenone, 2-hydroxy-4-acetoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2′-di-hydroxy-4-methoxybenzophenone, 2, 2′-di-hydroxy-4,4′-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4- (2-hydroxy-3- And methacryloxy) propoxybenzophenone. As a benzotriazole ultraviolet absorber, 2 (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2 (2′-hydroxy-5′-tert-butylphenyl) ) Benzotriazole, 2 (2′-hydroxy-3 ′, 5′-di-tert-amylphenyl) benzotriazole, 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5 Examples include chlorobenzotriazole, 2 (2′-hydroxy-5′-tert-octylphenyl) benzotriazole, and the like. Examples of salicylic acid esters include phenyl salicylate, p-octylphenyl salicylate, and p-tert-butylphenyl salicylate. Among these exemplified ultraviolet absorbers, in particular, 2-hydroxy-4-methoxybenzophenone, 2,2′-di-hydroxy-4,4′-methoxybenzophenone, 2 (2′-hydroxy-3′-tert-butyl- 5'-methylphenyl) -5-chlorobenzotriazole, 2 (2'-hydroxy-5'-tert-butylphenyl) benzotriazole, 2 (2'-hydroxy-3 ', 5'-di-tert-amylphenyl) ) Benzotriazole, 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole is particularly preferred.

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

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

  0.001-5 mass parts is preferable with respect to 100 mass parts of cellulose acylates, and, as for the addition amount of a ultraviolet absorber, 0.01-1 mass part is more preferable. If the addition amount is less than 0.001 part by mass, the effect of addition cannot be sufficiently exhibited. If the addition amount exceeds 5 parts by mass, the ultraviolet absorber may bleed out to the film surface within the above range. Is preferable.

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

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

  The plasticizer is preferably a phosphate ester or a carboxylic acid ester. The plasticizer may be triphenyl phosphate (TPP), tricresyl phosphate (TCP), cresyl diphenyl phosphate, octyl diphenyl phosphate, biphenyl diphenyl phosphate (BDP), trioctyl phosphate, tributyl phosphate, dimethyl phthalate (DMP) ), Diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP), diethyl hexyl phthalate (DEHP), triethyl O-acetylcitrate (OACTE), tributyl O-acetylcitrate ( OACTB), acetyl triethyl citrate, acetyl tributyl citrate, butyl oleate, methyl acetyl ricinoleate, dibutyl sebacate, tria Chin, tributyrin, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, and more preferably one selected from butyl phthalyl butyl glycolate. Furthermore, the plasticizer is preferably (di) pentaerythritol esters, glycerol esters, diglycerol esters. The addition amount of the plasticizer is preferably 1 to 30 parts by mass with respect to 100 parts by mass of cellulose acylate.

These additives may be added at any time in the dope preparation process, but may be added to the final preparation process of the dope preparation process by adding the preparation process. 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 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 and the like, but these are conventionally known techniques. The glass transition point Tg measured with a dynamic viscoelasticity measuring device for cellulose acylate film (Vibron: DVA-225 (ITG Measurement & Control Co., Ltd.)) is determined at 70 to 150 ° C. Furthermore, it is preferable that the elastic modulus measured with a tensile tester (Strograph-R2 (Toyo Seiki)) is 1500 to 4000 MPa. More preferably, the glass transition point Tg is 80 to 135 ° C. and the elastic modulus is 1500 to 3000 MPa. That is, the cellulose acylate film used in the present invention preferably has a glass transition point Tg and an elastic modulus within the above ranges from the viewpoint of process suitability for polarizing plate processing and liquid crystal display device assembly.
Furthermore, regarding the additive, the Japan Society of Invention and Innovation Technical Bulletin No. 2001-1745 (issued March 15, 2001, Japan Society of Invention) p. Those described in detail after 16 can be used as appropriate.

(Retardation expression agent)
In the present invention, it is preferable to use a retardation enhancer in order to greatly develop optical anisotropy and realize a preferable retardation value.
Examples of the retardation enhancer that can be used in the present invention include those composed of rod-shaped or discotic compounds.
As the rod-like or discotic compound, a compound having at least two aromatic rings can be used.
The addition amount of the retardation developer composed of the rod-like compound is preferably 0.1 to 30 parts by mass, and preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymer component containing cellulose acylate. Further preferred.
The discotic retardation enhancer is preferably used in a range of 0.05 to 20 parts by mass, and in a range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymer component containing cellulose acylate. More preferably, it is used in the range of 0.2 to 5 parts by mass, and most preferably in the range of 0.5 to 2 parts by mass.
Since the discotic compound is superior to the rod-like compound in Rth retardation expression, it is preferably used when a particularly large Rth retardation is required.
Two or more retardation developing agents may be used in combination.
The retardation developer composed of a rod-like or discotic compound preferably has maximum absorption in the wavelength region of 250 to 400 nm, and preferably has substantially no absorption in the visible region.

The discotic compound will be described. As the discotic compound, a compound having at least two aromatic rings can be used.
In the present specification, the “aromatic ring” includes an aromatic heterocycle in addition to an aromatic hydrocarbon ring.
The aromatic hydrocarbon ring is particularly preferably a 6-membered ring (that is, a benzene ring).
The aromatic heterocycle is generally an unsaturated heterocycle. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As the hetero atom, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable. Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring , Pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring.
As the aromatic ring, benzene ring, furan ring, thiophene ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, triazole ring, pyridine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring are preferable, In particular, a 1,3,5-triazine ring is preferably used. Specifically, for example, a compound disclosed in JP 2001-166144 A is preferably used as the discotic compound.

The number of aromatic rings contained in the discotic compound is preferably 2 to 20, more preferably 2 to 12, still more preferably 2 to 8, and most preferably 2 to 6. preferable.
The bond relationship between two aromatic rings can be classified into (a) a condensed ring, (b) a direct bond with a single bond, and (c) a bond through a linking group (for aromatic rings). , Spiro bonds cannot be formed). The connection relationship may be any of (a) to (c).

Examples of the condensed ring (a condensed ring of two or more aromatic rings) include an indene ring, a naphthalene ring, an azulene ring, a fluorene ring, a phenanthrene ring, an anthracene ring, an acenaphthylene ring, a biphenylene ring, a naphthacene ring, Pyrene ring, indole ring, isoindole ring, benzofuran ring, benzothiophene ring, indolizine ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring, purine ring, indazole ring, chromene ring, quinoline ring, isoquinoline Ring, quinolidine ring, quinazoline ring, cinnoline ring, quinoxaline ring, phthalazine ring, pteridine ring, carbazole ring, acridine ring, phenanthridine ring, xanthene ring, phenazine ring, phenothiazine ring, phenoxathiin ring, phenoxazine ring and thiant It includes emissions ring. Naphthalene ring, azulene ring, indole ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring and quinoline ring are preferred.

The single bond (b) is preferably a bond between carbon atoms of two aromatic rings. Two aromatic rings may be bonded with two or more single bonds to form an aliphatic ring or a non-aromatic heterocyclic ring between the two aromatic rings.

The linking group in (c) is also preferably bonded to carbon atoms of two aromatic rings. The linking group is preferably an alkylene group, an alkenylene group, an alkynylene group, —CO—, —O—, —NH—, —S—, or a combination thereof. Examples of linking groups composed of combinations are shown below. In addition, the relationship between the left and right in the following examples of the linking group may be reversed.
c1: -CO-O-
c2: —CO—NH—
c3: -alkylene-O-
c4: —NH—CO—NH—
c5: —NH—CO—O—
c6: —O—CO—O—
c7: -O-alkylene-O-
c8: -CO-alkenylene-
c9: -CO-alkenylene-NH-
c10: -CO-alkenylene-O-
c11: -alkylene-CO-O-alkylene-O-CO-alkylene-
c12: -O-alkylene-CO-O-alkylene-O-CO-alkylene-O-
c13: -O-CO-alkylene-CO-O-
c14: -NH-CO-alkenylene-
c15: -O-CO-alkenylene-

The aromatic ring and the linking group may have a substituent.
Examples of substituents include halogen atoms (F, Cl, Br, I), hydroxyl groups, carboxyl groups, cyano groups, amino groups, nitro groups, sulfo groups, carbamoyl groups, sulfamoyl groups, ureido groups, alkyl groups, alkenyls. Group, alkynyl group, aliphatic acyl group, aliphatic acyloxy group, alkoxy group, alkoxycarbonyl group, alkoxycarbonylamino group, alkylthio group, alkylsulfonyl group, aliphatic amide group, aliphatic sulfonamido group, aliphatic substituted amino group An aliphatic substituted carbamoyl group, an aliphatic substituted sulfamoyl group, an aliphatic substituted ureido group, and a non-aromatic heterocyclic group.

The alkyl group preferably has 1 to 8 carbon atoms. A chain alkyl group is preferable to a cyclic alkyl group, and a linear alkyl group is particularly preferable. The alkyl group may further have a substituent (eg, hydroxy group, carboxy group, alkoxy group, alkyl-substituted amino group). Examples of alkyl groups (including substituted alkyl groups) include methyl, ethyl, n-butyl, n-hexyl, 2-hydroxyethyl, 4-carboxybutyl, 2-methoxyethyl, and 2- A diethylaminoethyl group is included.
The alkenyl group preferably has 2 to 8 carbon atoms. A chain alkenyl group is preferable to a cyclic alkenyl group, and a linear alkenyl group is particularly preferable. The alkenyl group may further have a substituent. Examples of the alkenyl group include a vinyl group, an allyl group, and a 1-hexenyl group.
The alkynyl group preferably has 2 to 8 carbon atoms. A chain alkynyl group is preferable to a cyclic alkynyl group, and a linear alkynyl group is particularly preferable. The alkynyl group may further have a substituent. Examples of the alkynyl group include ethynyl group, 1-butynyl group and 1-hexynyl group.

The aliphatic acyl group preferably has 1 to 10 carbon atoms. Examples of the aliphatic acyl group include an acetyl group, a propanoyl group, and a butanoyl group.
The aliphatic acyloxy group preferably has 1 to 10 carbon atoms. Examples of the aliphatic acyloxy group include an acetoxy group.
The number of carbon atoms of the alkoxy group is preferably 1 to 8. The alkoxy group may further have a substituent (eg, alkoxy group). Examples of the alkoxy group (including a substituted alkoxy group) include a methoxy group, an ethoxy group, a butoxy group, and a methoxyethoxy group.
The alkoxycarbonyl group preferably has 2 to 10 carbon atoms. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group.
The number of carbon atoms of the alkoxycarbonylamino group is preferably 2 to 10. Examples of the alkoxycarbonylamino group include a methoxycarbonylamino group and an ethoxycarbonylamino group.

The alkylthio group preferably has 1 to 12 carbon atoms. Examples of the alkylthio group include a methylthio group, an ethylthio group, and an octylthio group.
The alkylsulfonyl group preferably has 1 to 8 carbon atoms. Examples of the alkylsulfonyl group include a methanesulfonyl group and an ethanesulfonyl group.
The aliphatic amide group preferably has 1 to 10 carbon atoms. Examples of the aliphatic amide group include an acetamide group.
The aliphatic sulfonamide group preferably has 1 to 8 carbon atoms. Examples of the aliphatic sulfonamido group include a methanesulfonamido group, a butanesulfonamido group, and an n-octanesulfonamido group.
The number of carbon atoms of the aliphatic substituted amino group is preferably 1 to 10. Examples of the aliphatic substituted amino group include a dimethylamino group, a diethylamino group, and a 2-carboxyethylamino group.
The aliphatic substituted carbamoyl group preferably has 2 to 10 carbon atoms. Examples of the aliphatic substituted carbamoyl group include a methylcarbamoyl group and a diethylcarbamoyl group.
The aliphatic substituted sulfamoyl group preferably has 1 to 8 carbon atoms. Examples of the aliphatic substituted sulfamoyl group include a methylsulfamoyl group and a diethylsulfamoyl group.
The number of carbon atoms in the aliphatic substituted ureido group is preferably 2 to 10. Examples of the aliphatic substituted ureido group include a methylureido group.
Examples of the non-aromatic heterocyclic group include a piperidino group and a morpholino group.
The molecular weight of the retardation developer composed of a discotic compound is preferably 300 to 800.

In the present invention, in addition to the aforementioned discotic compound, a rod-shaped compound having a linear molecular structure can also be preferably used. The linear molecular structure means that the molecular structure of the rod-like compound is linear in the most thermodynamically stable structure. The most thermodynamically stable structure can be obtained by crystal structure analysis or molecular orbital calculation. For example, molecular orbital calculation can be performed using molecular orbital calculation software (eg, WinMOPAC2000, manufactured by Fujitsu Limited) to determine the molecular structure that minimizes the heat of formation of the compound. The molecular structure being linear means that in the thermodynamically most stable structure obtained by calculation as described above, the angle of the main chain constituting the molecular structure is 140 degrees or more.

As the rod-shaped compound, those having at least two aromatic rings are preferable, and as the rod-shaped compound having at least two aromatic rings, a compound represented by the following general formula (1) is preferable.

General formula (1): Ar1-L1-Ar2

In the general formula (1), Ar1 and Ar2 are each independently an aromatic group.
In the present specification, the aromatic group includes an aryl group (aromatic hydrocarbon group), a substituted aryl group, an aromatic heterocyclic group, and a substituted aromatic heterocyclic group.
An aryl group and a substituted aryl group are more preferable than an aromatic heterocyclic group and a substituted aromatic heterocyclic group. The heterocycle of the aromatic heterocyclic group is generally unsaturated. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As a hetero atom, a nitrogen atom, an oxygen atom or a sulfur atom is preferable, and a nitrogen atom or a sulfur atom is more preferable.
As the aromatic ring of the aromatic group, a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, a thiazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyrimidine ring and a pyrazine ring are preferable, and a benzene ring is particularly preferable. .

Examples of the substituent of the substituted aryl group and the substituted aromatic heterocyclic group include a halogen atom (F, Cl, Br, I), a hydroxyl group, a carboxyl group, a cyano group, an amino group, an alkylamino group (eg, methyl). Amino group, ethylamino group, butylamino group, dimethylamino group), nitro group, sulfo group, carbamoyl group, alkylcarbamoyl group (eg, N-methylcarbamoyl group, N-ethylcarbamoyl group, N, N-dimethylcarbamoyl group) ), Sulfamoyl group, alkylsulfamoyl group (eg, N-methylsulfamoyl group, N-ethylsulfamoyl group, N, N-dimethylsulfamoyl group), ureido group, alkylureido group (eg, N -Methylureido group, N, N-dimethylureido group, N, N, N'-trimethylureido group), alkyl group (eg, Methyl, ethyl, propyl, butyl, pentyl, heptyl, octyl, isopropyl, s-butyl, t-amyl, cyclohexyl, cyclopentyl), alkenyl (eg, vinyl, allyl) Group, hexenyl group), alkynyl group (eg, ethynyl group, butynyl group), acyl group (eg, formyl group, acetyl group, butyryl group, hexanoyl group, lauryl group), acyloxy group (eg, acetoxy group, butyryloxy group, Hexanoyloxy group, lauryloxy group), alkoxy group (eg, methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, heptyloxy group, octyloxy group), aryloxy group (eg, phenoxy group), Alkoxycarbonyl group (eg, methoxycarbonyl group, ethoxycarbonyl group, Ropoxycarbonyl group, butoxycarbonyl group, pentyloxycarbonyl group, heptyloxycarbonyl group), aryloxycarbonyl group (eg, phenoxycarbonyl group), alkoxycarbonylamino group (eg, butoxycarbonylamino group, hexyloxycarbonylamino group) , Alkylthio groups (eg, methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, heptylthio group, octylthio group), arylthio groups (eg, phenylthio group), alkylsulfonyl groups (eg, methylsulfonyl group, ethylsulfonyl group) , Propylsulfonyl group, butylsulfonyl group, pentylsulfonyl group, heptylsulfonyl group, octylsulfonyl group), amide group (eg, acetamido group, butyramide group, hexylamide group, Uriruamido group) and a non-aromatic Hajime Tamaki (e.g., morpholyl groups include pyrazinyl group).

Examples of the substituent of the substituted aryl group and the substituted aromatic heterocyclic group include a halogen atom, a cyano group, a carboxyl group, a hydroxyl group, an amino group, an alkyl-substituted amino group, an acyl group, an acyloxy group, an amide group, an alkoxycarbonyl group, Alkoxy groups, alkylthio groups and alkyl groups are preferred.
The alkyl part and alkyl group of the alkylamino group, alkoxycarbonyl group, alkoxy group and alkylthio group may further have a substituent. Examples of the alkyl moiety and the substituent of the alkyl group include halogen atom, hydroxyl, carboxyl, cyano, amino, alkylamino group, nitro, sulfo, carbamoyl, alkylcarbamoyl group, sulfamoyl, alkylsulfamoyl group, ureido, alkylureido Group, alkenyl group, alkynyl group, acyl group, acyloxy group, acylamino group, alkoxy group, aryloxy group, alkoxycarbonyl group, aryloxycarbonyl group, alkoxycarbonylamino group, alkylthio group, arylthio group, alkylsulfonyl group, amide group And non-aromatic heterocyclic groups. As the substituent for the alkyl moiety and the alkyl group, a halogen atom, hydroxyl, amino, alkylamino group, acyl group, acyloxy group, acylamino group, alkoxycarbonyl group and alkoxy group are preferable.

In the general formula (1), L1 is a divalent linking group selected from an alkylene group, an alkenylene group, an alkynylene group, —O—, —CO— and a combination thereof.
The alkylene group may have a cyclic structure. As the cyclic alkylene group, cyclohexylene is preferable, and 1,4-cyclohexylene is particularly preferable. As the chain alkylene group, a linear alkylene group is more preferable than a branched alkylene group.
The alkylene group preferably has 1 to 20 carbon atoms, more preferably 1 to 15, more preferably 1 to 10, still more preferably 1 to 8, and most preferably 1 to 6. It is.

The alkenylene group and alkynylene group preferably have a chain structure rather than a cyclic structure, and more preferably have a linear structure rather than a branched chain structure.
The number of carbon atoms of the alkenylene group and the alkynylene group is preferably 2 to 10, more preferably 2 to 8, further preferably 2 to 6, further preferably 2 to 4, and most preferably 2. (Vinylene or ethynylene).
The arylene group preferably has 6 to 20 carbon atoms, more preferably 6 to 16, and still more preferably 6 to 12.

In the molecular structure of the general formula (1), the angle formed by Ar1 and Ar2 across L1 is preferably 140 degrees or more.
As the rod-like compound, a compound represented by the following formula (2) is more preferable.

Formula (2): Ar1-L2-X-L3-Ar2

In the general formula (2), Ar1 and Ar2 are each independently an aromatic group. The definition and examples of the aromatic group are the same as those of Ar1 and Ar2 in the general formula (1).

In the general formula (2), L 2 and L 3 are each independently a divalent linking group selected from an alkylene group, —O—, —CO— and a group consisting of a combination thereof.
The alkylene group preferably has a chain structure rather than a cyclic structure, and more preferably has a linear structure rather than a branched chain structure.
The alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, more preferably 1 to 6, still more preferably 1 to 4, and 1 or 2 (methylene or Most preferred is ethylene).
L2 and L3 are particularly preferably —O—CO— or —CO—O—.

In the general formula (2), X is 1,4-cyclohexylene, vinylene or ethynylene.
Specific examples of the compound represented by the general formula (1) or (2) include compounds described in [Chemical Formula 1] to [Chemical Formula 11] of JP-A No. 2004-109657.

Other preferred compounds are shown below.

Two or more rod-shaped compounds having a maximum absorption wavelength (λmax) shorter than 250 nm in the ultraviolet absorption spectrum of the solution may be used in combination.
The rod-like compound can be synthesized by a method described in the literature. References include Mol. Cryst. Liq. Cryst., 53, 229 (1979), 89, 93 (1982), 145, 111 (1987), 170, 43 Page (1989), J. Am. Chem. Soc., 113, 1349 (1991), 118, 5346 (1996), 92, 1582 (1970), J. Org Chem., 40, 420 (1975), Tetrahedron, 48, 16, 3437 (1992).

The cellulose acylate film used as a protective film may contain a matting agent. Usable matting agents (fine particles) 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, Mention may be made of magnesium silicate and calcium phosphate. Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable. The silicon dioxide fine particles preferably have a primary average particle size 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.
The amount of silicon dioxide fine particles used is preferably 0.01 to 0.3 parts by mass with respect to 100 parts by mass of the polymer component containing cellulose acylate.

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. When it is larger than 1.5 μm, the haze becomes strong, and when it is smaller than 0.2 μm, the effect of preventing stain is reduced.
The primary and secondary particle diameters are determined by observing the particles in the film with a scanning electron microscope and using the diameter of a circle circumscribing the particles as the particle diameter. Also, 200 particles are observed at different locations, and the average value is taken as the average particle diameter.

  As fine particles of silicon dioxide, for example, commercially available products such as Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (manufactured by 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 preferred 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 in-line 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.

Next, the organic solvent used for preparing the cellulose acylate solution will be described.
As the organic solvent, any of a chlorinated solvent containing a chlorinated organic solvent as a main solvent and a non-chlorinated solvent not containing a chlorinated organic solvent can be used.
(Chlorine solvent)
In preparing the cellulose acylate solution used in the present invention, a chlorinated organic solvent is preferably used as the main solvent. In the present invention, the type of the chlorinated organic solvent is not particularly limited as long as the object can be achieved within a range where the cellulose acylate can be dissolved, cast and formed. 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 in the total amount of the organic solvent. Other organic solvents used in combination with the chlorinated organic solvent in the present invention will be described below. That is, as another preferable 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.
Examples of combinations of chlorinated organic solvents and other organic solvents include the following compositions, but are not limited thereto.

Dichloromethane / methanol / ethanol / butanol (80/10/5/5, parts by mass),
Dichloromethane / acetone / methanol / propanol (80/10/5/5, parts by mass),
Dichloromethane / methanol / butanol / cyclohexane (80/10/5/5, parts by mass),
Dichloromethane / methyl ethyl ketone / methanol / butanol (80/10/5/5, parts by mass),
・ Dichloromethane / acetone / methyl ethyl ketone / ethanol / isopropanol (75/10/10/5/7, parts by mass)
・ Dichloromethane / cyclopentanone / methanol / isopropanol (80/10/5/8, part by mass)
Dichloromethane / methyl acetate / butanol (80/10/10, parts by mass),
Dichloromethane / cyclohexanone / methanol / hexane (70/20/5/5, parts by mass)
Dichloromethane / methyl ethyl ketone / acetone / methanol / ethanol (50/20/20/5/5, parts by mass),
・ Dichloromethane / 1, 3 dioxolane / methanol / ethanol (70/20/5/5, part by mass),
Dichloromethane / dioxane / acetone / methanol / ethanol (60/20/10/5/5, parts by mass),
Dichloromethane / acetone / cyclopentanone / ethanol / isobutanol / cyclohexane (65/10/10/5/5/5, parts by mass),
・ Dichloromethane / methyl ethyl ketone / acetone / methanol / ethanol (70/10/10/5/5, 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 / cyclopentanone / ethanol / butanol (65/20/10/5, parts by mass),
And so on.

Next, a non-chlorine organic solvent that is preferably used in preparing a cellulose acylate solution 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 cellulose acylate can be dissolved and cast and formed into a film. The non-chlorine organic solvent used in the present invention is preferably a solvent selected from esters, ketones and ethers having 3 to 12 carbon atoms. The ester, ketone and ether 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 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 non-chlorine organic solvent used in the above cellulose acylate is selected from the various viewpoints described above, and is preferably as follows. That is, the non-chlorine solvent is preferably a mixed solvent containing the non-chlorine organic solvent as a main solvent, and is a mixed solvent of three or more different solvents, wherein the first solvent is methyl acetate, ethyl acetate, At least one selected from methyl formate, ethyl formate, acetone, dioxolane, and dioxane, or a mixture thereof; the second solvent is selected from ketones having 4 to 7 carbon atoms or acetoacetate; The solvent is a mixed solvent selected from alcohols or hydrocarbons having 1 to 10 carbon atoms, more preferably alcohols having 1 to 8 carbon atoms. Note that when the first solvent is a mixed liquid of two or more kinds of solvents, the second solvent may be omitted. The first solvent is more preferably methyl acetate, acetone, methyl formate, ethyl formate, or a mixture thereof, and the second solvent is preferably methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl acetyl acetate, or a mixed solvent thereof. It may be.

  The alcohol as the third solvent may be linear, branched or cyclic, and is preferably a saturated aliphatic hydrocarbon. 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. These alcohols and hydrocarbons as the third solvent may be used alone or in combination of two or more, and are not particularly limited. As the third solvent, preferred specific compounds include alcohol, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and cyclohexanol, cyclohexane, hexane, Are methanol, ethanol, 1-propanol, 2-propanol, 1-butanol.

The mixing ratio of the above three types of mixed solvents is 20 to 95% by mass for the first solvent, 2 to 60% by mass for the second solvent, and 2 to 30% by mass for the third solvent in the total amount of the mixed solvent. The first solvent is preferably 30 to 90% by mass, the second solvent is 3 to 50% by mass, and the third alcohol is preferably 3 to 25% by mass. . In particular, it is preferable that the first solvent is 30 to 90% by mass, the second solvent is 3 to 30% by mass, and the third solvent is alcohol and 3 to 15% by mass. The non-chlorine-based organic solvent used in the present invention described above is more specifically described in JIII Journal of Technical Disclosure No. 2001-1745 (issued March 15, 2001, Invention Association) p. 12-16.
Preferred combinations of non-chlorine organic solvents can include the following, but are not limited thereto.

-Methyl acetate / acetone / methanol / ethanol / butanol (75/10/5/5/5, parts by mass),
-Methyl acetate / acetone / methanol / ethanol / propanol (75/10/5/5/5, parts by mass),
Methyl acetate / acetone / methanol / butanol / cyclohexane (75/10/5/5/5, parts by mass),
・ Methyl acetate / acetone / ethanol / butanol (81/8/7/4, parts by mass)
・ Methyl acetate / acetone / ethanol / butanol (82/10/4/4, parts by mass)
・ Methyl acetate / acetone / ethanol / butanol (80/10/4/6, part by mass)
Methyl acetate / methyl ethyl ketone / methanol / butanol (80/10/5/5, parts by mass),
-Methyl acetate / acetone / methyl ethyl ketone / ethanol / isopropanol (75/10/10/5/7, parts by mass)
Methyl acetate / cyclopentanone / methanol / isopropanol (80/10/5/8, parts by mass),
・ Methyl acetate / acetone / butanol (85/5/5, part by mass),
Methyl acetate / cyclopentanone / acetone / methanol / butanol (60/15/15/5/6, parts by mass),
-Methyl acetate / cyclohexanone / methanol / hexane (70/20/5/5, parts by mass)
・ Methyl acetate / methyl ethyl ketone / acetone / methanol / ethanol (50/20/20/5/5, part by mass),
・ Methyl acetate / 1,3-dioxolane / methanol / ethanol (70/20/5/5, parts by mass),
-Methyl acetate / dioxane / acetone / methanol / ethanol (60/20/10/5/5, parts by mass),
Methyl acetate / acetone / cyclopentanone / ethanol / isobutanol / cyclohexane (65/10/10/5/5/5, parts by mass),

・ Methyl formate / methyl ethyl ketone / acetone / methanol / ethanol (50/20/20/5/5, part by mass),
-Methyl formate / acetone / ethyl acetate / ethanol / butanol / hexane (65/10/10/5/5/5, parts by mass)
Acetone / methyl acetoacetate / methanol / ethanol (65/20/10/5, parts by mass),
Acetone / cyclopentanone / ethanol / butanol (65/20/10/5, parts by mass),
Acetone / 1,3-dioxolane / ethanol / butanol (65/20/10/5, parts by mass),
1,3-dioxolane / cyclohexanone / methyl ethyl ketone / methanol / butanol (55/20/10/5/5/5, parts by mass)
Etc.
Further, a cellulose acylate solution prepared by the following method can also be used.
A method of preparing a cellulose acylate solution with methyl acetate / acetone / ethanol / butanol (81/8/7/4, parts by mass) and adding 2 parts by weight of butanol after filtration and concentration. Methyl acetate / acetone / ethanol / Butanol (84/10/4/2, part by mass) A method for adding a cellulose acylate solution and adding 4 parts by weight of butanol after filtration and concentration. Methyl acetate / acetone / ethanol (84/10/6, A part of the dope used in the present invention is added with dichloromethane in addition to the above-mentioned non-chlorine organic solvent. You may make it contain below mass%.

(Characteristics of cellulose acylate solution)
The cellulose acylate solution is preferably a solution in which cellulose acylate is dissolved in the organic solvent at a concentration of 10 to 30% by mass from the viewpoint of film forming casting suitability, and more preferably 13 to 27% by mass. It is particularly preferably 15 to 25% by mass. The method for carrying out the cellulose acylate at these concentrations may be carried out so as to obtain a predetermined concentration at the stage of dissolution, or it is prepared as a low-concentration solution (for example, 9 to 14% by mass) and then concentrated as described later You may adjust to a predetermined high concentration solution by a process. Furthermore, after preparing a high-concentration cellulose acylate solution in advance, various additives may be added to obtain a predetermined low-concentration cellulose acylate solution, and any method is suitable for cellulose acylate solution concentration. If it is carried out to become, there is no particular problem.

Next, in the present invention, the aggregate molecular weight of cellulose acylate in a diluted solution in which the cellulose acylate solution is 0.1 to 5% by mass with an organic solvent having the same composition is 150,000 to 15 million. It is preferable in terms of solubility. More preferably, the associated molecular weight is 180,000 to 9 million. This associated molecular weight can be determined by a static light scattering method. In this case, it is preferable to dissolve so that the inertial square radius required at the same time is 10 to 200 nm. A more preferable inertial square radius is 20 to 200 nm. Furthermore, it is preferable to dissolve so that the second virial coefficient is −2 × 10 ⁻⁴ to + 4 × 10 ^−4, and more preferably, the second virial coefficient is −2 × 10 ⁻⁴ to + 2 × 10 ^−4. It is.

Here, the definition of the associated molecular weight, the inertial square radius and the second virial coefficient in the present invention will be described. These are measured using the static light scattering method according to the following method. The measurement is performed in a dilute region for the convenience of the apparatus, but these measured values reflect the behavior of the dope in the high concentration region.
First, cellulose acylate is dissolved in a solvent used for the dope to prepare 0.1 mass%, 0.2 mass%, 0.3 mass%, and 0.4 mass% solutions. In order to prevent moisture absorption, the cellulose acylate is dried at 120 ° C. for 2 hours, and is measured at 25 ° C. and 10% RH. The dissolution method is carried out according to the method employed at the time of dope dissolution (room temperature dissolution method, cooling dissolution method, high temperature dissolution method). Subsequently, the solution and the solvent are filtered through a 0.2 μm Teflon (registered trademark) filter. Then, the static light scattering of the filtered solution is measured at an interval of 10 ° from 30 ° to 140 ° at 25 ° C. using a light scattering measuring device (DLS-700 manufactured by Otsuka Electronics Co., Ltd.). The obtained data is analyzed by the BERRY plot method. In addition, the refractive index required for this analysis uses the value of the solvent calculated | required with the Abbe refractive system, and the refractive index concentration gradient (dn / dc) uses the differential refractometer (Otsuka Electronics Co., Ltd. DRM-1021). Measure using the solvent and solution used for light scattering measurement.

(Dope preparation)
Next, preparation of a cellulose acylate solution (dope) will be described. The method for dissolving the cellulose acylate is not particularly limited, and may be room temperature, or a cooling dissolution method or a high-temperature dissolution method, or a combination thereof. Regarding these, for example, JP-A-5-163301, JP-A-61-106628, JP-A-58-127737, JP-A-9-95544, JP-A-10-95854, JP-A-10-45950, JP 2000-53784, JP 11-322946, JP 11-322947, JP 2-276830, JP 2000-273239, JP 11-71463, JP 04-259511, Special JP 2000-273184, JP-A-11-323017, JP-A-11-302388, etc. describe methods for preparing cellulose acylate solutions. The above-described method for dissolving cellulose acylate in an organic solvent is applicable to the present invention as long as it is within the scope of the present invention. For details of these, particularly for non-chlorine-based solvent systems, the Japan Society of Invention and Innovation Technical Bulletin No. 2001-1745 (issued March 15, 2001, Invention Association) p. It is carried out in the manner described in detail in 22-25. Furthermore, the cellulose acylate dope solution suitable for the present invention is usually subjected to solution concentration and filtration. Similarly, the Japan Institute of Invention and Technology Publication No. 2001-1745 (issued March 15, 2001, Invention Association) p . 25 in detail. 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.

  It is preferable that the cellulose acylate solution has a viscosity and a dynamic storage elastic modulus within the ranges described below because it is easy to cast. 1 mL of the sample solution is measured with a rheometer (CLS 500) using a Steel Cone having a diameter of 4 cm / 2 ° (both manufactured by TA Instruments). Measurement conditions were measured at Oscillation Step / Temperature Ramp, varying from 40 ° C to -10 ° C at 2 ° C / min, and static non-Newtonian viscosity n * (Pa · s) at 40 ° C and storage at -5 ° C Obtain the elastic modulus G '(Pa). The sample solution is preliminarily kept at the measurement start temperature until the liquid temperature becomes constant, and then the measurement is started. In the present invention, the viscosity at 40 ° C. is 1 to 400 Pa · s, the dynamic storage elastic modulus at 15 ° C. is preferably 500 Pa or more, and more preferably the viscosity at 40 ° C. is 10 to 200 Pa · s. And the dynamic storage elastic modulus in 15 degreeC is 100-1 million. Furthermore, it is preferable that the dynamic storage elastic modulus at a low temperature is large. For example, when the casting support is −5 ° C., the dynamic storage elastic modulus is preferably 10,000 to 1,000,000 Pa at −5 ° C. When the body is at −50 ° C., the dynamic storage elastic modulus at −50 ° C. is preferably 10,000 to 5 million Pa.

  In the present invention, by using the above-mentioned specific cellulose acylate, a high concentration dope can be obtained, and a cellulose acylate 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 cellulose acylate solution, it is preferable to use a filter having an absolute filtration accuracy of 0.1 to 100 μm, and it is more preferable to use a filter having an absolute filtration accuracy of 0.5 to 25 μm. 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 1.2 MPa or less, further 1.0 MPa or less, and particularly preferably 0.2 MPa or less. As the filter medium, conventionally known materials such as glass fibers, cellulose fibers, filter paper, fluororesins such as tetrafluoroethylene resin can be preferably used, and ceramics, metals and the like are particularly preferably used. The viscosity of the cellulose acylate solution immediately before film formation may be in a range that can be cast during film formation, and is usually prepared in a range of 10 Pa · s to 2000 Pa · s, preferably 30 Pa · s to 1000 Pa. · S is more preferable, and 40 Pa · s to 500 Pa · s is more preferable. The temperature at this time is not particularly limited as long as it is a temperature at the time of casting, but is preferably −5 to + 70 ° C., more preferably −5 to + 55 ° C.

(Membrane production; production method of cellulose acylate film)
Next, the manufacturing method of the said cellulose acylate film is demonstrated below. When a protective film consists only of the said cellulose acylate film, the following description is applied to the manufacturing method of the protective film of this invention.
The cellulose acylate film may be produced by biaxial stretching at a stretching ratio of 30 to 100% in a predetermined X direction and 10 to 60% in a Y direction orthogonal to the X direction.
Further, stretching in at least one direction of the X direction and the Y direction is biaxially stretched at a stretching speed of 70 to 200% / min. The film surface temperature at the time of extending | stretching at least one direction among a X direction and a Y direction is 130-180 degreeC. The amount of residual solvent when peeling off from the support is 50 to 100% by mass. The residual solvent amount at the end of biaxial stretching in the X direction and the Y direction is 15 to 30% by mass.
In the following, description will be given in order.
The cellulose acylate film can be obtained by forming a film using the cellulose acylate solution. As the film forming method and equipment, 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, and the dope is run endlessly from the die (slit) of the pressure die. The dry-dried dope film (also referred to as web) is peeled off from the metal support at a peeling point that is uniformly cast on the metal support and substantially rounds the metal support. Both ends of the obtained web are sandwiched between clips, transported by a tenter while keeping the width, dried, then transported by a roll group of a drying device, dried, and wound up to a predetermined length by 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 cellulose acylate solution (dope) is casted on a drum or band when a cellulose acylate film is produced by a solvent cast method, and the solvent is evaporated to form a film. It is preferable to adjust the concentration of the dope before casting so that the solid content is 5 to 40% 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 2000-301555, JP 2000-301558, JP 07-032391, JP 03-193316, JP 05-086212, JP 62-037113, JP 02-276607. The methods described in JP-A Nos. 55-014201, 02-111511, and 02-208650 can be used in the present invention.

(Multilayer casting)
The cellulose acylate solution may be cast as a single layer liquid on a smooth band or drum as a metal support, or a plurality of cellulose acylate liquids of two or more layers may be cast. When casting a plurality of cellulose acylate solutions, produce a film while casting and laminating a solution containing cellulose acylate from a plurality of casting openings provided at intervals in the traveling direction of the metal support. For example, the methods described in JP-A-61-158414, JP-A-1-122419, and JP-A-11-198285 can be applied. A film may also be formed by casting a cellulose acylate solution from two casting ports. For example, Japanese Patent Publication Nos. 60-27562, 61-94724, 61-947245, 61-947245, This can be carried out by the methods described in JP-A Nos. 61-104813, 61-158413, and 6-134933. Further, a cellulose acylate film in which a flow of a high-viscosity cellulose acylate solution described in JP-A-56-162617 is wrapped with a low-viscosity cellulose acylate solution and the high- and low-viscosity cellulose acylate solutions are simultaneously extruded. A casting method may be used. Furthermore, it is also a preferable aspect 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, by using two casting ports, peeling the film formed on the metal support by the first casting port, and performing the second casting on the side that was in contact with the metal support surface, A film may be prepared, for example, a method described in Japanese Patent Publication No. 44-20235. The cellulose acylate solutions to be cast may be the same solution or different cellulose acylate solutions, and are not particularly limited. In order to give a function to a plurality of cellulose acylate layers, a cellulose acylate solution corresponding to the function may be extruded from each casting port. Furthermore, the cellulose acylate solution can be cast by simultaneously casting other functional layers (for example, an adhesive layer, a dye layer, an antistatic layer, an antihalation layer, a UV absorbing layer, a polarizing layer).

  In the conventional single-layer liquid, it is necessary to extrude a high-concentration and high-viscosity cellulose acylate solution in order to obtain the required film thickness. In many cases, this causes a problem such as a fault or flatness. As a solution to this, by casting a plurality of cellulose acylate solutions from a casting port, a highly viscous solution can be extruded onto a metal support at the same time. Not only can it be produced, but also the use of a concentrated cellulose acylate solution can reduce the drying load and increase the film production speed. In the case of co-casting, the inner and outer thicknesses are not particularly limited, but preferably the outer side is preferably 1 to 50% of the total film thickness, and 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 cellulose acylate film having a laminated structure can be produced by co-casting cellulose acylate solutions having different additive concentrations such as the above-mentioned plasticizer, ultraviolet absorber and matting agent. For example, a cellulose acylate 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 plasticizer 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 plasticizer and ultraviolet absorber between the core layer and the skin layer. For example, the skin layer contains at least one of a low-volatile plasticizer and an ultraviolet absorber, and the core layer is made 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 to contain a peeling accelerator only in the skin layer on the metal support side. It is also preferable to add more alcohol, which is a poor solvent, to the skin layer than the core layer in order to cool the metal support by the cooling drum method to gel the solution. 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 cellulose acylate during 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, but 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 described in the above publication can be obtained. The endlessly running metal support used to produce the cellulose acylate film suitable for the present invention includes a drum whose surface is mirror-finished by chrome plating and a stainless steel belt (band and band) which is mirror-finished by surface polishing. May be used). One or two or more pressure dies used for producing a cellulose acylate film suitable for the present invention may be 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 cellulose acylate solution used for casting is preferably −10 to 55 ° C., more preferably 25 to 50 ° C. In that case, all of the processes may be the same, or may be different at various points in the process. If they are different, the temperature may be a desired temperature just before casting.

(Dry)
The drying of the dope on the metal support involved in the production of the cellulose acylate 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, A method of applying hot air from the back of the drum or belt, contacting the temperature-controlled liquid from the back of the belt or drum opposite the dope casting surface, and heating the drum or belt by heat transfer to control the surface temperature Although there is a heat transfer 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 ° C. lower than the boiling point of the lowest boiling solvent. Is preferred. This is not the case when the casting dope is cooled and peeled off without drying.
The Re value and Rth value of the cellulose acylate film can also be adjusted by adjusting the temperature on the metal support on which the dope film is cast, the temperature and amount of drying air applied to the dope film cast on the metal support. Can be adjusted. In particular, the Rth value is greatly affected by the drying conditions on the metal support. Increasing the temperature of the metal support, or increasing the temperature of the drying air applied to the dope film, or increasing the air volume of the drying air, that is, increasing the amount of heat applied to the dope film, lowers the Rth value. Rth is increased by reducing. In particular, the drying of the first half part immediately after casting and before peeling off greatly affects the Rth value.

(Extension process)
The retardation of the cellulose acylate film suitable for the present invention can be adjusted by stretching treatment. Furthermore, there is also a method of positively stretching in the width direction. For example, JP-A-62-115035, JP-A-4-152125, JP-A-4-284221, JP-A-4-298310, and JP-A-11 -48271, and the like. This stretches the produced film in order to increase the front retardation value of the cellulose acylate film.
The film is stretched simultaneously or sequentially by biaxial stretching. In order to achieve a large optical anisotropy, it is necessary to stretch the film at a high stretch ratio, and it is 30 to 100% in the predetermined X direction, preferably 50 to 100%, particularly preferably 60 to 100%, Biaxial stretching is preferably performed at a stretching ratio of 10 to 60%, preferably 30 to 60%, particularly preferably 40 to 60% in the Y direction orthogonal to the X direction.
The X direction and the Y direction may be perpendicular to each other, but the X direction is preferably the film width direction and the Y direction is the film longitudinal direction (flow direction). Further, “orthogonal” means that the Y direction is within a range of 90 ° ± 5 ° with respect to the X direction.
A large optical anisotropy can be obtained by setting the draw ratio in the X direction and the draw ratio in the Y direction within the above ranges.
In addition, a draw ratio means extending | stretching to the length of twice the length of the film of an unstretched state, for example, when set to 100% of draw ratio.

The film is stretched under heating conditions. In order to achieve a large optical anisotropy, it is necessary to stretch the film at a high stretch ratio. For this purpose, the film surface temperature during stretching is higher than the apparent glass transition temperature Tg of the film during stretching. Higher is preferred. In the present invention, the acylate film is stretched at 130 to 180 ° C. The film is preferably stretched at 140 to 180 ° C, more preferably 150 to 180 ° C.
In order to implement a high draw ratio, the residual solvent amount of the film during stretching may be increased instead of increasing the film surface temperature during stretching. Specifically, the residual solvent amount at the time of stretching can be defined by the residual solvent amount at the time of peeling off the web from the support or the residual solvent amount at the end of stretching. The amount of residual solvent at the time of peeling is 50 to 100% by mass, preferably 60 to 100% by mass, more preferably 70 to 100% by mass, and most preferably 80 to 100% by mass. The residual solvent amount at the end of stretching is 15 to 30% by mass, and preferably 20 to 30% by mass. The residual solvent amount (%) is defined by (A−B) / B × 100. Here, A is the mass of the web, and B is the mass after drying the web at 140 ° C. for 60 minutes.

Another means for achieving a large optical anisotropy is to increase the stretching speed. In the present invention, the stretching speed in the X or Y direction is 70 to 200% / min, preferably 80 to 200% / min, and most preferably 90 to 200% / min.
In order to reduce variation in the in-plane slow axis in the width direction, it is preferable to provide a relaxation step after transverse stretching. In the relaxation step, it is preferable to adjust the width of the film after relaxation to a range of 100 to 70% (relaxation rate of 0 to 30%) with respect to the width of the film before relaxation. The temperature in the relaxation step is preferably the apparent glass transition temperature Tg-10 to Tg + 20 ° C. of the film.
Here, the apparent Tg of the film in the stretching process is that the film containing the residual solvent is enclosed in an aluminum pan, and the temperature is increased from 25 ° C. to 150 ° C. at 20 ° C./min with a differential scanning calorimeter (DSC). Tg was determined by obtaining an endothermic curve.

The film thickness of the cellulose acylate film obtained after drying is preferably in the range of 20 to 70 μm in consideration of forming the protective film only with the cellulose acylate film, and more preferably in the range of 20 to 60 μm. The range of 20-50 micrometers is especially preferable. In order to reduce the internal haze of the film, it is effective to reduce the film thickness.
Further, in order to improve the display unevenness due to Re, Rth, and slow axis angle affected by the film thickness unevenness of the film, the film thickness unevenness is preferably 0.5 μm or less, and 0.4 μm or less. More preferably, it is more preferably 0.3 μm or less. In order to reduce the film thickness unevenness of the film, it is effective to perform a stretching treatment.
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 film thickness can also be adjusted by stretching. The width of the cellulose acylate film obtained as described above is preferably 0.5 to 3 m, more preferably 0.6 to 2.5 m, and still more preferably 0.8 to 2.2 m. The length is preferably 100 to 10000 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 preferably 3 mm to 50 mm, more preferably 5 mm to 30 mm, and the height is preferably 0.5 to 500 μm, more preferably 1 to 200 μm. This may be a single push or a double push.

1. -2 Antifungal antireflection film In this invention, the polymer film utilized as a protective film may have a functional layer. An example is an antiglare reflective film having an antiglare layer and a low refractive index layer on a polymer film. This example will be described below. The polymer film is not particularly limited, but a cellulose acylate film is preferable.
[Anti-glare layer]
The antiglare layer is formed for the purpose of contributing to the film antiglare properties due to surface scattering, and preferably hard coat properties for improving the scratch resistance of the film. Therefore, it preferably contains a translucent resin capable of imparting hard coat properties, translucent fine particles for imparting antiglare properties, and a solvent as essential components.

<Translucent fine particles>
The average particle diameter of the translucent fine particles is preferably 0.5 to 10 μm, more preferably 2.0 to 6.0 μm. If the average particle size is less than 0.5 μm, the light scattering angle distribution spreads to a wide angle, which may cause blurring of characters on the display. On the other hand, if it exceeds 10 μm, it is necessary to increase the film thickness of the antiglare layer, which causes problems such as an increase in curl and an increase in material cost.
Specific examples of the translucent fine particles include, for example, poly ((meth) acrylate) particles, crosslinked poly ((meth) acrylate) particles, polystyrene particles, crosslinked polystyrene particles, crosslinked poly (acryl-styrene) particles, and melamine resin particles. Preferred examples include resin particles such as benzoguanamine resin particles. Of these, cross-linked polystyrene particles, cross-linked poly ((meth) acrylate) particles, and cross-linked poly (acryl-styrene) particles are preferably used, and the transparent particles are selected according to the refractive index of each light-transmitting fine particle selected from these particles. By adjusting the refractive index of the light-sensitive resin, internal haze, surface haze, and centerline average roughness can be achieved. Specifically, a translucent resin (having a refractive index of 1.50 to 1.53 after curing) mainly composed of a trifunctional or higher functional (meth) acrylate monomer preferably used in an antiglare layer as described later A combination of translucent fine particles composed of a crosslinked poly (meth) acrylate polymer having an acrylic content of 50 to 100% by mass (preferably 55 to 100% by mass, more preferably 60 to 100% by mass) is preferable. A combination of a translucent resin and translucent fine particles (refractive index of 1.48 to 1.54) made of a crosslinked poly (styrene-acrylic) copolymer is preferred.

  Further, two or more kinds of translucent fine particles having different particle diameters may be used in combination. It is possible to impart an antiglare property with the light-transmitting fine particles having a larger particle diameter, and to reduce the roughness of the surface with the light-transmitting fine particles having a smaller particle diameter.

The translucent fine particles are preferably blended in the formed antiglare layer so as to be contained in an amount of 3 to 30% by mass in the total solid content of the antiglare layer. More preferably, it is 5-20 mass%. When it is less than 3% by mass, the antiglare property is insufficient, and when it exceeds 30% by mass, problems such as image blur, surface turbidity and glare occur.
Moreover, the density of the translucent fine particles is preferably 10 to 2500 mg / m ² , more preferably 10 to 1000 mg / m ² , and still more preferably 100 to 700 mg / m ² .

The refractive index of the translucent resin is preferably 1.45 to 1.70, more preferably 1.48 to 1.65. In order to adjust the refractive index of the antiglare layer, the kind and amount ratio of the light-transmitting resin and the light-transmitting fine particles may be appropriately selected. How to select can be easily known experimentally in advance.
In the present invention, the absolute value of the difference in refractive index between the translucent resin and the translucent fine particles (the refractive index of the translucent fine particles−the refractive index of the translucent resin) is preferably 0.00 to It is 0.03, More preferably, it is 0.00-0.02, More preferably, it is 0.00-0.01. When this difference exceeds 0.03, problems such as film character blur, a decrease in dark room contrast, and surface turbidity occur.
The refractive index of the translucent resin is preferably 1.45 to 1.70, and more preferably 1.48 to 1.65.
Further, the refractive index of the translucent fine particles is preferably 1.42 to 1.70, and more preferably 1.48 to 1.65.
Here, the refractive index of the light-transmitting resin and the light-transmitting fine particles can be quantitatively evaluated by directly measuring with an Abbe refractometer or by measuring a spectral reflection spectrum or spectral ellipsometry.

  The film thickness of the antiglare layer is preferably 1 to 10 μm, and more preferably 1.2 to 8 μm. If it is too thin, the hard property is insufficient, and if it is too thick, curling and brittleness may be deteriorated and workability may be lowered.

<Translucent resin>
The translucent resin is preferably a binder polymer having a saturated hydrocarbon chain or a polyether chain as a main chain, and more preferably a binder polymer having a saturated hydrocarbon chain as a main chain. The binder polymer preferably has a crosslinked structure.
The translucent resin is preferably a polymer obtained by using an ionizing radiation curable compound having two or more functional groups, more preferably three or more functional groups as a main component. In addition, the "main component" said here means containing 50 mass% or more. The content is more preferably 55% by mass or more, and most preferably 60% by mass or more.
As the binder polymer having a saturated hydrocarbon chain as a main chain, a polymer of an ethylenically unsaturated monomer is preferable. As the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure, a (co) polymer of a monomer having two or more, more preferably three or more ethylenically unsaturated groups is preferable.
In order to increase the refractive index of the binder polymer, the monomer structure has a high refractive index including at least one atom selected from an aromatic ring, a halogen atom other than fluorine, a sulfur atom, a phosphorus atom, and a nitrogen atom. It is also possible to select a monomer having a ratio, a monomer having a fluorene skeleton in the molecule, and the like.

Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid [for example, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di ( (Meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (Meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3- Chlorohexane tetramethacrylate, polyurethane polyacrylate, polyester polyacrylate], ethylene oxide modified products and caprolactone modified products of the above esters, vinylbenzene and its derivatives [eg, 1,4-divinylbenzene, 4-vinylbenzoic acid-2- Acryloyl ethyl ester, 1,4-divinylcyclohexanone], vinyl sulfone (eg, divinyl sulfone), acrylamide (eg, methylenebisacrylamide) and methacrylamide. Two or more of these monomers may be used in combination.
Among the above, a translucent resin having a tri- or higher functional (meth) acrylate monomer as a main component is particularly preferable. The term “main component” as used herein means containing 50% by mass or more. The content is more preferably 55% by mass or more, and most preferably 60% by mass or more.

  Specific examples of the high refractive index monomer include (meth) acrylates having a fluorene skeleton, bis (4-methacryloylthiophenyl) sulfide, vinyl naphthalene, vinyl phenyl sulfide, 4-methacryloxyphenyl-4′-methoxyphenyl thioether, etc. Is mentioned. Two or more of these monomers may be used in combination.

Polymerization of the monomer having an ethylenically unsaturated group can be performed by irradiation with ionizing radiation or heating in the presence of a photo radical (polymerization) initiator or a thermal radical (polymerization) initiator.
Accordingly, the antiglare layer is composed of a monomer for forming a translucent resin such as the above-mentioned ethylenically unsaturated monomer, a photo radical initiator or a thermal radical initiator, translucent fine particles, and an inorganic material as will be described later if necessary. It can be formed by preparing a coating liquid containing a filler and curing the coating liquid on a transparent support by a polymerization reaction by ionizing radiation or heat.

Photo radical (polymerization) initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfides Examples include compounds, fluoroamine compounds and aromatic sulfoniums. Examples of acetophenones include 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethylphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone and 2 -Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone is included. Examples of benzoins include benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether. Examples of the benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone. Examples of phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide.
Various examples are described in the latest UV curing technology (p.159, issuer; Kazuhiro Takashiro, publisher; Technical Information Association, Inc., published in 1991), and are useful for the present invention.
Preferable examples of commercially available photocleavable photoradical (polymerization) initiators include Irgacure (651, 184, 907) manufactured by Ciba Specialty Chemicals.
The photo radical (polymerization) initiator is preferably used in the range of 0.1 to 15 parts by mass, more preferably in the range of 1 to 10 parts by mass with respect to 100 parts by mass of the polyfunctional monomer.
In addition to the photoradical (polymerization) initiator, a photosensitizer may be used. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone and thioxanthone.

As the thermal radical initiator, organic or inorganic peroxides, organic azo, diazo compounds, and the like can be used.
Specifically, benzoyl peroxide, halogen benzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide, butyl hydroperoxide as organic peroxides, hydrogen peroxide, peroxides as inorganic peroxides. Ammonium sulfate, potassium persulfate, etc., 2-azo-bis-isobutyronitrile, 2-azo-bis-propionitrile, 2-azo-bis-cyclohexanedinitrile, etc. as diazo compounds, diazoaminobenzene, p -Nitrobenzenediazonium etc. can be mentioned.

The polymer having a polyether as the main chain is preferably a ring-opening polymer of a polyfunctional epoxy compound. The ring-opening polymerization of the polyfunctional epoxy compound can be performed by irradiation with ionizing radiation or heating in the presence of a photoacid generator or a thermal acid generator.
Accordingly, a coating liquid containing a polyfunctional epoxy compound, a photoacid generator or a thermal acid generator, translucent fine particles and an inorganic filler is prepared, and the coating liquid is applied onto a transparent support and then polymerized by ionizing radiation or heat. It can be cured by reaction to form an antiglare layer.

Instead of or in addition to a monomer having two or more ethylenically unsaturated groups, a monomer having a crosslinkable functional group is used to introduce a crosslinkable functional group into the polymer, and by reaction of this crosslinkable functional group, A crosslinked structure may be introduced into the binder polymer.
Examples of the crosslinkable functional group include isocyanate group, epoxy group, aziridine group, oxazoline group, aldehyde group, carbonyl group, hydrazine group, carboxyl group, methylol group and active methylene group. Vinylsulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane, and metal alkoxide such as tetramethoxysilane can also be used as a monomer for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used. That is, in the present invention, the crosslinkable functional group may not react immediately but may exhibit reactivity as a result of decomposition.
These binder polymers having a crosslinkable functional group can form a crosslinked structure by heating after coating.

In addition to the above light-transmitting fine particles, silicon, titanium, zirconium, aluminum, indium, zinc, tin are used for the antiglare layer in order to adjust the refractive index of the layer and reduce the haze value caused by internal scattering. And an inorganic filler comprising an oxide of at least one metal selected from antimony and having an average particle size of 0.2 μm or less, preferably 0.1 μm or less, more preferably 0.06 μm or less. Good. Since these inorganic fillers generally have a specific gravity higher than that of organic substances and can increase the density of the coating composition, they also have the effect of slowing the sedimentation rate of the light-transmitting fine particles.
The surface of the inorganic filler used in the antiglare layer is also preferably subjected to a silane coupling treatment or a titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used.
When using these inorganic fillers, the addition amount is preferably 10 to 90% of the total mass of the antiglare layer, more preferably 20 to 80%, and particularly preferably 30 to 75%.
Such an inorganic filler does not scatter because its particle size is sufficiently smaller than the wavelength of light, and a dispersion in which the filler is dispersed in a binder polymer behaves as an optically uniform substance.
In addition, an organosilane compound (preferably at least one of a hydrolyzate of an organosilane compound represented by the following general formula (1) and a partial condensate thereof) can be used for the antiglare layer. The addition amount of the organosilane compound is preferably 0.001 to 50 mass%, more preferably 0.01 to 20 mass%, based on the total solid content of the antiglare layer.

<Surfactant for antiglare layer>
In order to ensure surface uniformity such as coating unevenness, drying unevenness, point defects, etc., the antiglare layer should be coated with either a fluorine-based surfactant or a silicone-based surfactant, or both for forming an antiglare layer. It is preferable to contain in a composition. In particular, a fluorine-based surfactant is preferably used because an effect of improving surface defects such as coating unevenness, drying unevenness, and point defects of the antiglare antireflection film appears with a smaller addition amount.
The purpose is to increase productivity by giving high-speed coating suitability while improving surface uniformity.

  Preferable examples of the fluorosurfactant include a fluoroaliphatic group-containing copolymer (sometimes abbreviated as “fluorine polymer”), and the fluoropolymer includes the following monomer (i): A copolymer containing an acrylic resin or a methacrylic resin and a vinyl monomer copolymerizable therewith (for example, the monomer (ii) below) containing the corresponding repeating unit is useful.

(I) Fluoroaliphatic group-containing monomer represented by the following general formula (i)

In the general formula (i), R ¹¹ represents a hydrogen atom or a methyl group, X represents an oxygen atom, a sulfur atom or —N (R ¹² ) —, m is an integer of 1 to 6, and n is 2 to 4. Represents an integer. R ¹² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, specifically a methyl group, an ethyl group, a propyl group, or a butyl group, preferably a hydrogen atom or a methyl group. X is preferably an oxygen atom.

(Ii) a monomer represented by the following general formula (b) copolymerizable with (i) above

In the general formula (ii), R ¹³ represents a hydrogen atom or a methyl group, Y represents an oxygen atom, a sulfur atom or —N (R ¹⁵ ) —, and R ¹⁵ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Specifically, it represents a methyl group, an ethyl group, a propyl group or a butyl group, preferably a hydrogen atom or a methyl group. Y is an oxygen atom, -N (H) -, and -N (CH ³⁾ - are preferred.
R ¹⁴ represents a linear, branched or cyclic alkyl group having 4 to 20 carbon atoms, which may have a substituent. Examples of the substituent for the alkyl group of R ¹⁴ include a hydroxyl group, an alkylcarbonyl group, an arylcarbonyl group, a carboxyl group, an alkyl ether group, an aryl ether group, a halogen atom such as a fluorine atom, a chlorine atom, and a bromine atom, a nitro group, and a cyano group. Amino groups and the like, but not limited thereto. Examples of the linear, branched or cyclic alkyl group having 4 to 20 carbon atoms include butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl and undecyl which may be linear and branched. Group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, octadecyl group, eicosanyl group, etc., and monocyclic cycloalkyl groups such as cyclohexyl group, cycloheptyl group and the like, bicycloheptyl group, bicyclodecyl group, tricycloundecyl group Polycyclic cycloalkyl groups such as tetracyclododecyl group, adamantyl group, norbornyl group, tetracyclodecyl group and the like are preferably used.

The amount of the fluoroaliphatic group-containing monomer represented by the general formula (a) used in the fluoropolymer used in the present invention is 10 mol% or more based on each monomer of the fluoropolymer, preferably Is 15 to 70 mol%, more preferably in the range of 20 to 60 mol%.

The preferred weight average molecular weight of the fluoropolymer used in the present invention is preferably 3000 to 100,000, more preferably 5,000 to 80,000.
Further, the preferable addition amount of the fluorine-based polymer used in the present invention is a coating solution from the viewpoint of the effect of the fluorine-based polymer, and from the viewpoint of drying of the coating film and performance as a coating film (for example, reflectance, scratch resistance). The range is 0.001 to 5% by mass, preferably 0.005 to 3% by mass, and more preferably 0.01 to 1% by mass.

Hereinafter, although the example of the specific structure of the fluorine-type polymer which consists of a fluoro aliphatic group containing monomer represented by general formula (i) is shown, it is not this limitation. In addition, the number in a formula shows the molar ratio of each monomer component. Mw represents a mass average molecular weight.

However, by using such a fluoropolymer, the surface energy of the antiglare layer is lowered due to segregation of functional groups containing F atoms on the surface of the antiglare layer, resulting in low refraction on the antiglare layer. When the rate layer is overcoated, there arises a problem that the antireflection performance deteriorates. This is presumably because minute unevenness that cannot be visually detected in the low refractive index layer deteriorates because the wettability of the curable composition used for forming the low refractive index layer deteriorates. To solve such problems, by adjusting the structure and amount of the fluorine-based polymer, the surface energy of the antiglare layer preferably in ^{20mN · m -1 ~50mN · m -1} , more preferably it was found that it is effective to control the ^{30mN · m -1 ~40mN · m -1} . In order to realize the surface energy as described above, F / C, which is a ratio of a peak derived from a fluorine atom and a peak derived from a carbon atom, measured by X-ray photoelectron spectroscopy is 0.1 to 1.5. is required.

  Alternatively, when an upper layer is applied, by selecting a fluorine-based polymer that is extracted by a solvent that forms the upper layer, it is not unevenly distributed on the lower layer surface (= interface), and adhesion between the upper layer and the lower layer can be obtained. In addition, it is possible to provide an antiglare antireflection film that maintains surface uniformity even during high-speed application and has high scratch resistance. By preventing the surface free energy from decreasing, the object can also be achieved by controlling the surface energy of the antiglare layer before application of the low refractive index layer within the above range. Examples of such materials include an acrylic resin, a methacrylic resin, and a vinyl monomer copolymerizable therewith, containing a repeating unit corresponding to a fluoroaliphatic group-containing monomer represented by the following general formula C (For example, a monomer represented by the following general formula D).

(Iii) A fluoroaliphatic group-containing monomer represented by the following general formula (iii)

In the general formula (iii), R ²¹ represents a hydrogen atom, a halogen atom or a methyl group, more preferably a hydrogen atom or a methyl group. X ² represents an oxygen atom, a sulfur atom or —N (R ²² ) —, more preferably an oxygen atom or —N (R ²² ) —, and still more preferably an oxygen atom. m is an integer from 1 to 6 (more preferably from 1 to 3, more preferably 1), and n is an integer from 1 to 18 (more preferably from 4 to 12, and even more preferably from 6 to 8). Represents. R ²² represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms which may have a substituent, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and further preferably a hydrogen atom or a methyl group. X is preferably an oxygen atom.
In addition, two or more kinds of fluoroaliphatic group-containing monomers represented by the general formula C may be contained in the fluorine-based polymer as constituent components.

(Iv) A monomer represented by the following general formula (iv) that can be copolymerized with the above (iii)

In the general formula (iv), R ²³ represents a hydrogen atom, a halogen atom or a methyl group, and more preferably a hydrogen atom or a methyl group. Y ² represents an oxygen atom, a sulfur atom or —N (R ²⁵ ) —, more preferably an oxygen atom or —N (R ²⁵ ) —, and still more preferably an oxygen atom. R ²⁵ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and still more preferably a hydrogen atom or a methyl group.
R ²⁴ is an optionally substituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an alkyl group containing a poly (alkyleneoxy) group, and an optionally substituted aromatic group. Represents a group (for example, a phenyl group or a naphthyl group). A linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, or an aromatic group having 6 to 18 carbon atoms in total is more preferable, and a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms. Is more preferable.

  Hereinafter, examples of specific structures of fluoropolymers containing a repeating unit corresponding to the fluoroaliphatic group-containing monomer represented by the general formula (iii) will be shown, but the present invention is not limited thereto. In addition, the number in a formula shows the molar ratio of each monomer component. Mw represents a mass average molecular weight.

  Further, if the surface energy is prevented from being lowered when the low refractive index layer is overcoated on the antiglare layer, the deterioration of the antireflection performance can be prevented. When applying an anti-glare layer, the surface tension of the coating solution is lowered by using a fluoropolymer to improve surface uniformity and maintain high productivity by high-speed application. After application of the anti-glare layer, corona treatment, UV treatment, heat treatment, saponification Corona treatment is particularly preferred using surface treatment techniques such as treatment and solvent treatment, but the surface energy of the antiglare layer before application of the low refractive index layer is controlled within the above range by preventing the surface free energy from decreasing. You can also achieve your goals.

  Moreover, you may add a thixotropic agent in the coating composition for forming an anti-glare layer. Examples of the thixotropic agent include silica and mica of 0.1 μm or less. In general, the content of these additives is preferably about 1 to 10 parts by mass with respect to 100 parts by mass of the ultraviolet curable resin.

Next, the low refractive index layer will be described below.
[Low refractive index layer]
The refractive index of the low refractive index layer possessed by the antireflection film is 1.30 to 1.55, preferably 1.35 to 1.45. When the refractive index is in the above range, the antireflection performance is improved without lowering the mechanical strength of the film.
Further, the low refractive index layer preferably satisfies the following formula (I) from the viewpoint of reducing the reflectance.
Formula (I): (mλ / 4) × 0.7 <n1 × d1 <(mλ / 4) × 1.3
In the formula, m is a positive odd number, n1 is the refractive index of the low refractive index layer, and d1 is the film thickness (nm) of the low refractive index layer. Further, λ is a wavelength, which is a value in the range of 500 to 550 nm. In addition, satisfy | filling said numerical formula (I) means that m (positive odd number, usually 1) which satisfy | fills numerical formula (I) exists in the said wavelength range.

The material for forming the low refractive index layer will be described below.
The low refractive index layer contains, for example, a fluorine-containing polymer as a main component (here, “main component” means 50% by mass or more. The content is more preferably 55% by mass or more, and 60% by mass or more. Most preferred.) Is a cured film formed by applying, drying and curing a curable composition.
<Fluoropolymer for low refractive index layer>
The fluorine-containing polymer has a coefficient of dynamic friction of 0.03 to 0.20, a contact angle with respect to water of 90 to 120 °, a sliding angle of pure water of 70 ° or less, and heat or A polymer that is cross-linked by ionizing radiation is preferable in terms of improving productivity in the case of coating and curing a roll film while transporting the web.
Further, when the antireflection film is mounted on an image display device, the lower the peel strength from a commercially available adhesive tape, the easier it is to peel off after sticking a seal or memo. Is more preferable, and 100 gf or less is most preferable. If it is less than 0.1 gf, the surface protective laminate film tends to peel off when applied to a polarizing plate, a display device or the like, which is not preferable. Further, the higher the surface hardness measured with a microhardness meter, the harder it is to scratch. Therefore, the surface hardness is preferably 0.3 GPa or more, and more preferably 0.5 GPa or more.

  The fluorine-containing polymer used for the low refractive index layer contains a fluorine atom in a range of 35 to 80% by mass (more preferably 45 to 70% by mass) and contains a crosslinkable or polymerizable functional group. For example, in addition to hydrolysates and dehydration condensates of perfluoroalkyl group-containing silane compounds [eg (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane], fluorine-containing monomer units and Examples thereof include a fluorine-containing copolymer having a crosslinking reactive unit as a constituent unit. In the case of a fluorinated copolymer, the main chain preferably consists of only carbon atoms. That is, it is preferable that the main chain skeleton does not have an oxygen atom or a nitrogen atom.

  Specific examples of the fluorine-containing monomer unit include, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, perfluorooctylethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3- Dioxoles, etc.), (meth) acrylic acid partial or fully fluorinated alkyl ester derivatives (for example, Biscoat 6FM (manufactured by Osaka Organic Chemicals) and M-2020 (manufactured by Daikin)), fully or partially fluorinated vinyl ethers, etc. However, perfluoroolefins are preferable, and hexafluoropropylene is particularly preferable from the viewpoint of refractive index, solubility, transparency, availability, and the like.

  Examples of the crosslinking reactive unit include a structural unit obtained by polymerization of a monomer having a self-crosslinking functional group in the molecule such as glycidyl (meth) acrylate and glycidyl vinyl ether; carboxyl group, hydroxy group, amino group, sulfo group A structural unit obtained by polymerization of a monomer having, for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, maleic acid, crotonic acid, etc. And a structural unit in which a crosslinkable reactive group such as a (meth) acryloyl group is introduced by a polymer reaction (for example, it can be introduced by a technique such as allowing acrylic acid chloride to act on a hydroxy group).

  In addition to the fluorine-containing monomer unit and the cross-linking reactive unit, from the viewpoint of solubility in a solvent, film transparency, and the like, a monomer not containing a fluorine atom is appropriately copolymerized to introduce another polymerization unit. You can also. There are no particular limitations on the monomer units that can be used in combination, such as olefins [ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.], acrylic esters [methyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid 2 -Ethylhexyl], methacrylates (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyl toluene, α-methylstyrene, etc.), vinyl ethers (methyl) Vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, etc.], vinyl esters [vinyl acetate, vinyl propionate, vinyl cinnamate, etc.], acrylamides [N-tertbutylacrylamide, N-silane] B hexyl acrylamide], methacrylamides, and acrylonitrile derivatives.

  As described in JP-A-10-25388 and JP-A-10-147739, a curing agent may be appropriately used in combination with the fluoropolymer.

The fluorine-containing polymer particularly useful in the present invention is a random copolymer of perfluoroolefin and vinyl ethers or vinyl esters. In particular, it preferably has a group capable of undergoing crosslinking reaction alone (radical reactive group such as (meth) acryloyl group, ring-opening polymerizable group such as epoxy group and oxetanyl group).
These crosslinkable group-containing polymerized units preferably occupy 5 to 70 mol%, particularly preferably 30 to 60 mol% of the total polymerized units of the polymer.

  A preferred form of the fluorine-containing polymer for the low refractive index layer used in the present invention is a copolymer represented by the general formula 1.

In General Formula 1, L represents a linking group having 1 to 10 carbon atoms, more preferably a linking group having 1 to 6 carbon atoms, particularly preferably a linking group having 2 to 4 carbon atoms, It may have a branched structure, may have a ring structure, or may have a heteroatom selected from O, N and S.
Preferred examples include * — (CH ₂ ) ₂ —O — **, * — (CH ₂ ) ₂ —NH — **, * — (CH ₂ ) ₄ —O — **, * — (CH ₂ ). _{6 -O - **, * - (} CH 2) 2 -O- (CH 2) 2 -O - **, * - CONH- (CH 2) 3 -O - **, * -CH 2 CH (OH ) CH ₂ —O — **, * —CH ₂ CH ₂ OCONH (CH ₂ ) ₃ —O — ** (* represents the connecting site on the polymer main chain side, and ** represents the connecting on the (meth) acryloyl group side) Represents a part). m represents 0 or 1;

  In general formula 1, X represents a hydrogen atom or a methyl group. From the viewpoint of curing reactivity, a hydrogen atom is more preferable.

  In the general formula 1, A represents a repeating unit derived from an arbitrary vinyl monomer, and is not particularly limited as long as it is a constituent component of a monomer copolymerizable with hexafluoropropylene. Tg (contributes to film hardness), solubility in solvents, transparency, slipperiness, dust / antifouling properties, etc., can be selected as appropriate, depending on the purpose, depending on the single or multiple vinyl monomers It may be configured.

  Preferred examples include methyl vinyl ether, ethyl vinyl ether, t-butyl vinyl ether, cyclohexyl vinyl ether, isopropyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, glycidyl vinyl ether, vinyl ethers such as allyl vinyl ether, vinyl acetate, vinyl propionate, butyric acid. (Meth) such as vinyl esters such as vinyl, methyl (meth) acrylate, ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, glycidyl methacrylate, allyl (meth) acrylate, (meth) acryloyloxypropyltrimethoxysilane Acrylates, styrene, styrene derivatives such as p-hydroxymethylstyrene, crotonic acid, maleic acid, itaconic acid Can be mentioned unsaturated carboxylic acids and derivatives thereof, more preferably ether derivatives, vinyl ester derivatives, particularly preferably a vinyl ether derivative.

x, y and z represent the mol% of each constituent component, preferably 30 ≦ x ≦ 60, 5 ≦ y ≦ 70, 0 ≦ z ≦ 65, more preferably 35 ≦ x ≦ 55, 30 ≦ y ≦. 60, 0 ≦ z ≦ 20, particularly preferably 40 ≦ x ≦ 55, 40 ≦ y ≦ 55, and 0 ≦ z ≦ 10. However, x + y + z = 100.
A particularly preferred form of the copolymer used in the present invention is General Formula 2.

In general formula 2, X represents the same meaning as in general formula 1, and the preferred range is also the same.
n represents an integer of 2 ≦ n ≦ 10, preferably 2 ≦ n ≦ 6, and particularly preferably 2 ≦ n ≦ 4.
B represents a repeating unit derived from an arbitrary vinyl monomer, and may be composed of a single composition or a plurality of compositions. As an example, what was demonstrated as an example of A in the said General formula 1 is applicable.
x, y, z1 and z2 represent mol% of each repeating unit, and x and y preferably satisfy 30 ≦ x ≦ 60 and 5 ≦ y ≦ 70, respectively, more preferably 35 ≦ x ≦ 55. 30 ≦ y ≦ 60, particularly preferably 40 ≦ x ≦ 55 and 40 ≦ y ≦ 55. z1 and z2 preferably satisfy 0 ≦ z1 ≦ 65 and 0 ≦ z2 ≦ 65, more preferably 0 ≦ z1 ≦ 30 and 0 ≦ z2 ≦ 10, and 0 ≦ z1 ≦ 10, 0 It is particularly preferable that ≦ z2 ≦ 5. However, x + y + z1 + z2 = 100.
For the copolymer represented by the general formula 1 or 2, for example, a (meth) acryloyl group is introduced into a copolymer comprising a hexafluoropropylene component and a hydroxyalkyl vinyl ether component by any one of the methods described above. Can be synthesized. As the reprecipitation solvent used in this case, isopropanol, hexane, methanol and the like are preferable.
Preferable specific examples of the copolymer represented by the general formula 1 or 2 include those described in [0035] to [0047] of JP-A-2004-45462. It can be synthesized by the method.

The curable composition preferably contains (A) the fluoropolymer, (B) inorganic fine particles, and (C) an organosilane compound described later.
<Inorganic fine particles for low refractive index layer>
The amount of the inorganic fine particles is preferably ^{1mg / m 2 ~100mg / m 2} , more preferably ^{5mg / m 2 ~80mg / m 2} , more preferably from ^{10mg / m 2 ~60mg / m 2} . If the amount is too small, the effect of improving the scratch resistance is reduced. If the amount is too large, fine irregularities are formed on the surface of the low refractive index layer, and the appearance such as black tightening and the integrated reflectance may deteriorate. It is preferable to be inside.
Since the inorganic fine particles are contained in the low refractive index layer, it is desirable that the inorganic fine particles have a low refractive index. Examples thereof include fine particles of magnesium fluoride and silica. In particular, in terms of refractive index, dispersion stability, and cost, the silica fine particles are the main component (here, “main component” means 50% by mass or more. The content is more preferably 55% by mass or more. 60% by mass or more is most preferable).
The average particle size of the inorganic fine particles is preferably 30% or more and 100% or less, more preferably 35% or more and 80% or less, and still more preferably 40% or more and 60% or less of the thickness of the low refractive index layer. That is, when the thickness of the low refractive index layer is 100 nm, the particle size of the silica fine particles is preferably 30 nm to 100 nm, more preferably 35 nm to 80 nm, and still more preferably 40 nm to 60 nm.
If the particle size of the inorganic fine particles is within the above range, the effect of improving the scratch resistance is sufficient, and it is difficult to form fine irregularities on the surface of the low refractive index layer. The
The inorganic fine particles may be either crystalline or amorphous, and may be monodispersed particles or aggregated particles as long as a predetermined particle size is satisfied. The shape is most preferably a spherical diameter, but there is no problem even if the shape is indefinite.
Here, the average particle diameter of the inorganic fine particles is measured by a Coulter counter.

In order to further reduce the increase in the refractive index of the low refractive index layer, the inorganic fine particles preferably have a hollow structure, and the refractive index of the inorganic fine particles is 1.17 to 1.40, more preferably 1. It is 17-1.35, More preferably, it is 1.17-1.30. Here, the refractive index represents the refractive index of the whole particle, and does not represent the refractive index of only the inorganic material of the outer shell in the case of hollow structure inorganic fine particles. At this time, when the radius of the void in the particle is a and the radius of the particle outer shell is b, the porosity x represented by the following formula (II) is preferably 10 to 60%, more preferably 20 to 60. %, Most preferably 30-60%.
Formula (II): x = (4πa 3/3) / (4πb 3/3) × 100
If the refractive index of the hollow inorganic fine particles is made lower and the porosity is increased, the thickness of the outer shell becomes thinner and the strength of the particles becomes weaker. From the viewpoint of scratch resistance, the refractive index is 1 Particles with a low refractive index of less than .17 do not hold.
The refractive index of the inorganic fine particles was measured with an Abbe refractometer (manufactured by Atago Co., Ltd.).

In addition, at least one kind of inorganic fine particles (hereinafter referred to as “small size inorganic fine particles”) having an average particle size of less than 25% of the thickness of the low refractive index layer is referred to as “inorganic fine particles (hereinafter referred to as“ small size inorganic fine particles ”). It may be used in combination with “large-size inorganic fine particles”.
Since the small-sized inorganic fine particles can be present in the gaps between the large-sized inorganic fine particles, they can contribute as a retaining agent for the large-sized inorganic fine particles.
When the low refractive index layer is 100 nm, the average particle size of the small-sized inorganic fine particles is preferably 1 nm to 20 nm, more preferably 5 nm to 15 nm, and particularly preferably 10 nm to 15 nm. Use of such inorganic fine particles is preferable in terms of raw material costs and a retaining agent effect.
As described above, the inorganic fine particles have an average particle size of 30 to 100% of the thickness of the low refractive index layer as described above, have a hollow structure, and have a refractive index of 1.17 to 1. What is 40 is used especially preferably.

Inorganic fine particles are treated with physical surface treatment such as plasma discharge treatment or corona discharge treatment in order to stabilize dispersion in the dispersion or coating solution, or to improve the affinity and binding properties with the binder component. Further, chemical surface treatment with a surfactant, a coupling agent or the like may be performed. Of these, the use of a coupling agent is particularly preferred. As the coupling agent, an alkoxy metal compound (eg, titanium coupling agent, silane coupling agent) is preferably used. Among these, silane coupling treatment is particularly effective.
The coupling agent is used as a surface treatment agent for the inorganic fine particles of the low refractive index layer in advance for surface treatment prior to the preparation of the layer coating solution, and is further added as an additive during preparation of the layer coating solution. It is preferable to make it contain in a layer.
The inorganic fine particles are preferably dispersed in the medium in advance before the surface treatment in order to reduce the load of the surface treatment.

Next, (C) the organosilane compound will be described.
<Organosilane compound for low refractive index layer>
The curable composition contains at least one of a hydrolyzate of an organosilane compound and a partial condensate thereof (hereinafter, the obtained reaction solution is also referred to as “sol component”). In particular, it is preferable in terms of achieving both the antireflection ability and the scratch resistance.
This sol component functions as a binder for the low refractive index layer by applying the curable composition and then condensing in a drying and heating process to form a cured product. Moreover, in this invention, since it has the said fluorine-containing polymer, the binder which has a three-dimensional structure is formed by irradiation of actinic light.
The organosilane compound is preferably represented by the following general formula (1).
Formula (1): (R ¹⁰ ) _m Si (X) _4-m
In the general formula (1), R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, hexyl, decyl, hexadecyl and the like. The alkyl group is preferably an alkyl group having 1 to 30 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 6 carbon atoms. Examples of the aryl group include phenyl and naphthyl, and a phenyl group is preferable.
X represents a hydroxyl group or a hydrolyzable group, for example, an alkoxy group (preferably an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group or an ethoxy group), a halogen atom (for example, Cl, Br, I or the like). ), And R ² COO (R ² is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Examples include CH ³ COO, C ² H ⁵ COO, etc.), preferably Is an alkoxy group, particularly preferably a methoxy group or an ethoxy group.
m represents an integer of 1 to 3, preferably 1 or 2, and particularly preferably 1.

When R ¹⁰ or X there are a plurality, a plurality of R ¹⁰ or X groups may be different, even the same, respectively.
The substituent contained in R ¹⁰ is not particularly limited, but a halogen atom (fluorine, chlorine, bromine, etc.), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (methyl, ethyl, i-propyl, propyl, t-butyl etc.), aryl groups (phenyl, naphthyl etc.), aromatic heterocyclic groups (furyl, pyrazolyl, pyridyl etc.), alkoxy groups (methoxy, ethoxy, i-propoxy, hexyloxy etc.), aryloxy (phenoxy etc.) ), Alkylthio groups (methylthio, ethylthio, etc.), arylthio groups (phenylthio, etc.), alkenyl groups (vinyl, 1-propenyl, etc.), acyloxy groups (acetoxy, acryloyloxy, methacryloyloxy, etc.), alkoxycarbonyl groups (methoxycarbonyl, ethoxy) Carbonyl, etc.), aryloxy Carbonyl groups (phenoxycarbonyl, etc.), carbamoyl groups (carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-methyl-N-octylcarbamoyl, etc.), acylamino groups (acetylamino, benzoylamino, acrylicamino, methacrylamino) Etc.), and these substituents may be further substituted.

When there are a plurality of R ^{10 s} , at least one of them is preferably a substituted alkyl group or a substituted aryl group.
As the hydrolyzate and partial condensate of the organosilane compound represented by the general formula (1), an organosilane compound having a vinyl polymerizable substituent represented by the following general formula (2) is preferable.

In the general formula (2), R ¹ represents a hydrogen atom, a methyl group, a methoxy group, an alkoxycarbonyl group, a cyano group, a fluorine atom, or a chlorine atom. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group. A hydrogen atom, a methyl group, a methoxy group, a methoxycarbonyl group, a cyano group, a fluorine atom and a chlorine atom are preferred, a hydrogen atom, a methyl group, a methoxycarbonyl group, a fluorine atom and a chlorine atom are more preferred, and a hydrogen atom and a methyl group Is particularly preferred.
Y represents a single bond or * -COO-**, * -CONH-** or * -O-**, preferably a single bond, * -COO-** or * -CONH-**, * -COO-** is more preferable, and * -COO-** is particularly preferable. * Represents a position bonded to ═C (R ¹ ) —, and ** represents a position bonded to L.

  L represents a divalent linking chain. Specifically, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group having a linking group (for example, ether, ester, amide, etc.) inside, and a linking group inside. A substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, an alkylene group having a linking group therein is preferred, an unsubstituted alkylene group, an unsubstituted arylene group Further, an alkylene group having an ether or ester linking group inside is more preferable, an unsubstituted alkylene group, and an alkylene group having an ether or ester linking group inside is particularly preferable. Examples of the substituent include a halogen, a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, and an aryl group, and these substituents may be further substituted.

l and m each represent a mole fraction (l represents a number satisfying the formula of l = 100−m). m represents the number of 0-50. As for m, the number of 0-40 is more preferable, and the number of 0-30 is especially preferable.
R ^{2 to} R ⁴ are preferably a halogen atom, a hydroxyl group, an unsubstituted alkoxy group, or an unsubstituted alkyl group. R ^{2 to} R ⁴ are more preferably a chlorine atom, a hydroxyl group, or an unsubstituted alkoxy group having 1 to 6 carbon atoms, more preferably a hydroxyl group or an alkoxy group having 1 to 3 carbon atoms, and particularly preferably a hydroxyl group or a methoxy group.
R ⁵ represents a hydrogen atom or an alkyl group. The alkyl group is preferably a methyl group or an ethyl group.
R ⁶ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.
Furthermore, the hydrolyzate of organosilane represented by the general formula (2) and / or the partial condensate thereof is a mixture of a plurality of compounds represented by the general formula (2) having specific l and m. It may be a hydrolyzate and / or a partial condensate thereof.

  The weight average molecular weight of the compound of the general formula (2) is preferably from 450 to 20000, more preferably from 500 to 10,000, even more preferably from 550 to 5000, when a component having a molecular weight of less than 300 generated in the synthesis process is excluded. 600 to 3000 is particularly preferable.

  The compound of the general formula (2) is synthesized using one or more silane compounds as starting materials. Although the specific example of the silane compound used as the starting material of General formula (2) is shown below, it is not limited.

M-48: CH ₃ —Si (OCH ₃ ) _{3
M-49: C 2 H 5} -Si (OCH 3) 3
_{M-50: t-C 4} H 9 -Si (OCH 3) 3

  Among these, it is particularly preferable to use (M-1), (M-2), (M-25), (M-48), and (M-49) as starting materials. Details of the synthesis method will be described later.

  At least one of the hydrolyzate of organosilane and its partial condensate preferably has low volatility in order to stabilize the performance of the coated product. Specifically, the volatilization amount per hour at 105 ° C. is 5 It is preferably at most mass%, more preferably at most 3 mass%, particularly preferably at most 1 mass%.

  The hydrolyzate and partial condensate of the organosilane compound are generally produced by treating the organosilane compound in the presence of a catalyst. Catalysts include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid; organic acids such as oxalic acid, acetic acid, formic acid, methanesulfonic acid and toluenesulfonic acid; inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia; triethylamine, Examples thereof include organic bases such as pyridine; metal alkoxides such as triisopropoxyaluminum and tetrabutoxyzirconium; metal chelate compounds having a metal such as Zr, Ti or Al as a central metal. In the present invention, it is preferable to use a metal chelate compound, an acid catalyst of inorganic acids and organic acids. Inorganic acids are preferably hydrochloric acid and sulfuric acid, and organic acids are preferably those having an acid dissociation constant (pKa value (25 ° C.)) of 4.5 or less in water, and further, acid dissociation constants in hydrochloric acid, sulfuric acid and water. Is preferably an organic acid having an acid dissociation constant of 2.5 or less in hydrochloric acid, sulfuric acid or water, more preferably an organic acid having an acid dissociation constant of 2.5 or less in water. Specifically, methanesulfonic acid, oxalic acid, phthalic acid, and malonic acid are more preferable, and oxalic acid is particularly preferable.

As the metal chelate compound represented by the general formula R ⁷ OH (wherein, R ⁷ is an alkyl group having 1 to 10 carbon atoms) alcohol and R ⁸ COCH ₂ COR ⁹ (where represented by, R ⁸ is the number of carbon atoms 1 to 10 alkyl groups, R ⁹ represents an alkyl group having 1 to 10 carbon atoms or a compound represented by an alkoxy group having 1 to 10 carbon atoms), and is selected from Zr, Ti, and Al. Any metal having a central metal as the metal can be used without any particular limitation. Within this category, two or more metal chelate compounds may be used in combination. The metal chelate compound used in the present invention has the general formula Zr (OR ⁷ ) p 1 (R ⁸ COCHCOR ⁹ ) p 2, Ti (OR ⁷ ) q 1 (R ⁸ COCHCOR ⁹ ) q 2, and Al (OR ⁷ ) r 1 (R ⁸ ). Those selected from the group of compounds represented by COCHCOR ⁹ ) r2 are preferred, and they serve to promote the condensation reaction of the hydrolyzate and partial condensate of the organosilane compound.
R ⁷ and R ⁸ in the metal chelate compound may be the same or different and each is an alkyl group having 1 to 10 carbon atoms, specifically, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, sec -Butyl group, t-butyl group, n-pentyl group, phenyl group and the like. R ⁹ represents an alkyl group having 1 to 10 carbon atoms as described above, or an alkoxy group having 1 to 10 carbon atoms, such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and n-butoxy. Group, sec-butoxy group, t-butoxy group and the like. In the metal chelate compound, p1, p2, q1, q2, r1, and r2 represent integers that satisfy p1 + p2 = 4, q1 + q2 = 4, and r1 + r2 = 3, respectively.

Specific examples of these metal chelate compounds include tri-n-butoxyethylacetoacetate zirconium, di-n-butoxybis (ethylacetoacetate) zirconium, n-butoxytris (ethylacetoacetate) zirconium, tetrakis (n-propylacetate). Zirconium chelate compounds such as acetate) zirconium, tetrakis (acetylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium; diisopropoxy bis (ethylacetoacetate) titanium, diisopropoxy bis (acetylacetate) titanium, diiso Titanium chelate compounds such as propoxy bis (acetylacetone) titanium; diisopropoxyethyl acetoacetate aluminum, diisopropyl Poxyacetylacetonate aluminum, isopropoxybis (ethylacetoacetate) aluminum, isopropoxybis (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonate) aluminum, monoacetylacetonate bis (ethyl) An aluminum chelate compound such as acetoacetate) aluminum.
Among these metal chelate compounds, tri-n-butoxyethyl acetoacetate zirconium, diisopropoxybis (acetylacetonate) titanium, diisopropoxyethyl acetoacetate aluminum, and tris (ethyl acetoacetate) aluminum are preferable. These metal chelate compounds can be used individually by 1 type or in mixture of 2 or more types. Moreover, the partial hydrolyzate of these metal chelate compounds can also be used.

  In the present invention, it is preferable that at least one of a β-diketone compound and a β-ketoester compound is further added to the curable composition. This will be further described below.

In the present invention, at least one of a β-diketone compound and a β-keto ester compound represented by the general formula R ⁸ COCH ₂ COR ⁹ is used, and the stability of the curable composition used in the present invention is improved. It acts as an agent. Here, R ⁸ represents an alkyl group having 1 to 10 carbon atoms, and R ⁹ represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. That is, by coordinating with a metal atom in the metal chelate compound (a compound of at least one of zirconium, titanium and aluminum compounds), at least one of hydrolyzate and partial condensate of organosilane compound by these metal chelate compounds. It is thought that the effect | action which accelerates | stimulates any condensation reaction is suppressed, and the effect | action which improves the storage stability of the obtained composition is comprised. R ⁸ and R ⁹ constitute a β- diketone compound and β- ketoester compound are the same as R ⁸ and R ⁹ constituting the metal chelate compound.

Specific examples of the β-diketone compound and β-ketoester compound include acetylacetone, methyl acetoacetate, ethyl acetoacetate, acetoacetate-n-propyl, acetoacetate-i-propyl, acetoacetate-n-butyl, acetoacetate- sec-butyl, acetoacetate-t-butyl, 2,4-hexane-dione, 2,4-heptane-dione, 3,5-heptane-dione, 2,4-octane-dione, 2,4-nonane-dione , 5-methyl-hexane-dione and the like. Of these, ethyl acetoacetate and acetylacetone are preferred, and acetylacetone is particularly preferred. These β-diketone compounds and β-ketoester compounds can be used alone or in admixture of two or more.
In the present invention, the β-diketone compound and the β-ketoester compound are preferably used in an amount of 2 mol or more, more preferably 3 to 20 mol, per 1 mol of the metal chelate compound from the viewpoint of the storage stability of the composition.

The compounding amount of the organosilane compound is preferably 0.1 to 50% by mass, more preferably 0.5 to 20% by mass, and most preferably 1 to 10% by mass based on the total solid content of the low refractive index layer.
The organosilane compound may be added directly to the curable composition (coating solution for anti-glare layer, low refractive index layer, etc.), but the organosilane compound is treated in the presence of a catalyst in advance to prepare the organosilane compound. It is preferable to prepare at least one of a hydrolyzate and a partial condensate of a silane compound and prepare the curable composition using the obtained reaction solution (sol solution). In the present invention, first, the organosilane is prepared. A composition containing a metal chelate compound and at least one of a hydrolyzate of the compound and a partial condensate thereof, and a solution obtained by adding at least one of a β-diketone compound and a β-ketoester compound to the antiglare layer or It is preferable to coat it by incorporating it in at least one coating solution of the low refractive index layer.

  5-100 mass% is preferable, the usage-amount of the sol component of the organosilane with respect to a fluorine-containing polymer in a low refractive index layer has more preferable 5-40 mass%, 8-35 mass% is still more preferable, 10-30 mass % Is particularly preferred. When the amount used is in the above range, the refractive index is appropriate, and the shape and surface shape of the film are good.

  An inorganic filler other than the above-described inorganic fine particles can be added to the curable composition in an addition amount within a range that does not impair the desired effect of the present invention. Details of the inorganic filler will be described later.

[Other substances contained in curable composition for low refractive index layer]
The curable composition is prepared by adding various additives, a radical polymerization initiator, and a cationic polymerization initiator to the (A) fluorine-containing polymer, (B) inorganic fine particles, and (C) the organosilane compound as necessary. Further, they are prepared by dissolving them in a suitable solvent. At this time, the concentration of the solid content is appropriately selected according to the use, but is generally about 0.01 to 60% by mass, preferably 0.5 to 50% by mass, particularly preferably 1% to 20% by mass. %.

  Curing agents such as polyfunctional (meth) acrylate compounds, polyfunctional epoxy compounds, polyisocyanate compounds, aminoplasts, polybasic acids or anhydrides thereof from the viewpoint of interfacial adhesion with the lower layer directly in contact with the low refractive index layer Can also be added in small amounts. When adding these, it is preferable to set it as the range of 30 mass% or less with respect to the total solid of a low refractive index layer film | membrane, It is more preferable to set it as the range of 20 mass% or less, The range of 10 mass% or less It is particularly preferable that

  In addition, for the purpose of imparting properties such as antifouling properties, water resistance, chemical resistance, and slipping properties, a known silicone compound or fluorine compound antifouling agent, slipping agent, and the like may be appropriately added. When these additives are added, it is preferably added in the range of 0.01 to 20% by mass of the total solid content of the low refractive index layer, more preferably in the range of 0.05 to 10% by mass. Particularly preferred is 0.1 to 5% by mass.

  Preferable examples of the silicone compound include those having a substituent at at least one of a terminal end and a side chain of a compound chain containing a plurality of dimethylsilyloxy units as repeating units. The compound chain containing dimethylsilyloxy as a repeating unit may contain a structural unit other than dimethylsilyloxy. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, fluoroalkyl group, polyoxyalkylene group, carboxyl group, amino group and the like. It is done. Although there is no restriction | limiting in particular in molecular weight, It is preferable that it is 100,000 or less, It is especially preferable that it is 50,000 or less, It is most preferable that it is 3000-30000. Although there is no restriction | limiting in particular in silicone atom content of a silicone type compound, it is preferable that it is 18.0 mass% or more, it is especially preferable that it is 25.0-37.8 mass%, and 30.0-37.0. Most preferably, it is mass%. Examples of preferred silicone compounds are X-22-174DX, X-22-2426, X-22-164B, X22-164C, X-22-170DX, X-22-176D, X, manufactured by Shin-Etsu Chemical Co., Ltd. -22-1821 (named above), manufactured by Chisso Corporation, FM-0725, FM-7725, FM-4421, FM-5521, FM6621, FM-1121, Gelest DMS-U22, RMS-033, RMS- 083, UMS-182, DMS-H21, DMS-H31, HMS-301, FMS121, FMS123, FMS131, FMS141, FMS221 (named above) but not limited thereto.

As the fluorine compound, a compound having a fluoroalkyl group is preferable. The fluoroalkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and a straight chain (for example, —CF ₂ CF ₃ , —CH ₂ (CF ₂ ) ₄ H, —CH ₂ (CF ₂ ) ₈ CF ₃ , —CH ₂ CH ₂ (CF ₂ ) ₄ H, etc.), even branched structures (eg, —CH (CF ₃ ) ₂ , —CH ₂ CF (CF ₃ ) ₂ , —CH (CH ₃ ) CF ₂ CF ₃ , —CH (CH ₃ ) (CF ₂ ) ₅ CF ₂ H, etc.), but alicyclic structures (preferably 5-membered or 6-membered rings such as perfluorocyclohexyl groups) , A perfluorocyclopentyl group or an alkyl group substituted with these, and may have an ether bond (for example, —CH ₂ OCH ₂ CF ₂ CF ₃ , —CH ₂ CH ₂ OCH ₂ C). ₄ F ₈ H, —CH ₂ CH ₂ OCH ₂ CH ₂ C ₈ F ₁₇ , —CH ₂ C H ₂ OCF ₂ CF ₂ OCF ₂ CF ₂ H, etc.). A plurality of the fluoroalkyl groups may be contained in the same molecule.
It is preferable that the fluorine-based compound further has a substituent that contributes to bond formation or compatibility with the low refractive index layer film. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, polyoxyalkylene group, carboxyl group, amino group and the like. The fluorine-based compound may be a polymer or an oligomer with a compound not containing a fluorine atom, and the molecular weight is not particularly limited. Although there is no restriction | limiting in particular in fluorine atom content of a fluorine-type compound, It is preferable that it is 20 mass% or more, It is especially preferable that it is 30-70 mass%, It is most preferable that it is 40-70 mass%. Examples of preferred fluorine-based compounds include Daikin Chemical Industries, Ltd., R-2020, M-2020, R-3833, M-3833 (named above), Dainippon Ink Co., Ltd., Megafac F-171. , F-172, F-179A, defender MCF-300 (trade name), etc., but are not limited thereto.

  For the purpose of imparting properties such as dust resistance and antistatic properties, a known cationic surfactant or a dustproof agent such as a polyoxyalkylene compound, an antistatic agent, or the like can be appropriately added. These dustproofing agent and antistatic agent may contain the structural unit as a part of the function in the above-mentioned silicone compound or fluorine compound. When these are added as additives, it is preferably added in the range of 0.01 to 20% by mass of the total solid content of the low refractive index layer, more preferably in the range of 0.05 to 10% by mass. Particularly preferred is 0.1 to 5% by mass. Examples of preferred compounds include, but are not limited to, Dainippon Ink Co., Ltd., Megafac F-150 (trade name), Toray Dow Corning Co., Ltd., SH-3748 (trade name), and the like. Do not mean.

[About other layers]
Another layer may be provided between the polymer film and the antiglare layer, and an antistatic layer (when there is a demand such as lowering the surface resistance value from the display side, there is a problem with dust on the surface etc. A hard coat layer (when the hardness is insufficient with only the antiglare layer), a moisture proof layer, an adhesion improving layer, a rainbow unevenness (interference unevenness) preventing layer, and the like. These layers can be formed by a known method.

The antiglare antireflection film can be formed by the following method, but is not limited to this method.
First, a coating solution containing components for forming each layer is prepared. In that case, the raise of the moisture content in a coating liquid can be suppressed by suppressing the volatilization amount of a solvent to the minimum. The moisture content in the coating solution is preferably 5% or less, more preferably 2% or less. The suppression of the volatilization amount of the solvent is achieved by improving the sealing property at the time of stirring after putting each material into the tank, minimizing the air contact area of the coating liquid at the time of liquid transfer operation, and the like. Moreover, you may provide the means to reduce the moisture content in a coating liquid during application | coating, or before and behind that.

  Filtration capable of removing almost all foreign substances (pointing to 90% or more) corresponding to the dry film thickness (about 50 nm to 120 nm) of the low refractive index layer directly formed on the coating solution for forming the antiglare layer It is preferable to Since the light-transmitting fine particles for imparting antiglare properties are equal to or greater than the film thickness of the low refractive index layer, the filtration should be performed on the intermediate liquid to which all materials other than the light-transmitting fine particles are added. Is preferred. In addition, when a filter capable of removing foreign substances having a small particle diameter as described above is not available, almost all foreign substances corresponding to the wet film thickness (about 1 to 10 μm) of the layer directly formed thereon are removed. It is preferable to perform filtration. By such means, the point defects of the layer formed directly thereon can be reduced.

Next, a coating solution for forming an antiglare layer and, if necessary, a low refractive index layer is applied on a transparent support by a coating method such as an extrusion method (die coating method) or a micro gravure method, dry. Thereafter, the monomer or curable resin for forming the antiglare layer or the low refractive index layer is cured by at least one of light irradiation and heating. As a result, an antiglare layer or a low refractive index layer is formed.
In order to supply the antiglare and antireflection film with high productivity, an extrusion method (die coating method) is preferably used.

  When forming the antiglare layer, it is preferable to apply the coating liquid in the range of 6 to 30 μm as a wet coating thickness directly or via another layer on the polymer film, and further from the viewpoint of preventing drying unevenness. The range of 3-20 micrometers is more preferable. Moreover, when forming a low refractive index layer, it is preferable to apply | coat a coating composition in the range of 1-10 micrometers as wet coating film thickness directly or via another layer on an anti-glare layer, More preferably, it is applied in the range of 5 μm.

  The antiglare layer and the low refractive index layer are applied on the polymer film directly or via other layers, and then conveyed in a web to a heated zone to dry the solvent. In this case, the temperature of the drying zone is preferably 25 ° C. to 140 ° C., the first half of the drying zone is relatively low temperature, and the second half is preferably relatively high temperature. However, it is preferably below the temperature at which components other than the solvent contained in the coating composition of each layer start to volatilize. For example, some of the commercially available photo radical generators used in combination with ultraviolet curable resins volatilize around several tens of percent within a few minutes in warm air at 120 ° C. Some acrylate monomers and the like undergo volatilization in warm air at 100 ° C. In such a case, it is preferable that it is below the temperature at which components other than the solvent contained in the coating composition of each layer start to volatilize as described above.

Moreover, the drying wind after apply | coating the coating composition of each layer on a transparent support body has the wind speed of the coating-film surface 0.1-2 m / sec while the solid content concentration of the said coating composition is 1-50%. It is preferable to be in the range in order to prevent drying unevenness.
Moreover, after apply | coating the coating composition of each layer on a transparent support body, the temperature difference of the conveyance roll and transparent support which contacts the surface opposite to the application surface of a transparent support within a drying zone is 0 degreeC-20. Within the range of ° C., drying unevenness due to heat transfer unevenness on the transport roll can be prevented, which is preferable.

After the solvent drying zone, the coating is cured by passing through a zone where each coating is cured by means of ionizing radiation and heat on the web. For example, if the coating film is UV curable, it is to cure each layer by irradiating an irradiation amount of ultraviolet rays of 10mJ / cm ² ~1000mJ / cm ² by an ultraviolet lamp preferred. At that time, the irradiation distribution in the width direction of the web is preferably 50 to 100%, more preferably 80 to 100%, including both ends with respect to the central maximum irradiation. Further, when it is necessary to purge the nitrogen gas or the like to reduce the oxygen concentration in order to promote surface hardening, the oxygen concentration is preferably 0.01 vol% to 5 vol%, and the distribution in the width direction is 2 in oxygen concentration. Volume% or less is preferable.

  Further, when the curing rate (100-residual functional group content) of the antiglare layer becomes a certain value of less than 100%, a low refractive index layer is provided thereon and at least one of ionizing radiation and heat. When the low refractive index layer is cured, if the curing rate of the lower antiglare layer is higher than before the low refractive index layer is provided, the adhesion between the antiglare layer and the low refractive index layer is improved, which is preferable.

1. -3 Combination Examples of Protective Films As described above, in the present invention, either one of the first and second protective films has a low moisture permeability polymer film (for example, a moisture permeability measured at 60 ° C. and 95% RH of 400 g / m ² / day or more) and a highly moisture-permeable polymer film (for example, a moisture permeability measured at 60 ° C. and 95% RH of 1000 g / m ² / day or more) may be used.
Examples of the highly moisture permeable polymer film include cellulose triacetate film. Moreover, as a commercial item, FUJITACTD80UL (made by Fuji Film) etc. are contained. On the other hand, examples of the low moisture permeability polymer film include the antiglare reflection film having the antiglare layer and the low refractive index layer, for example, the antiglare reflection having a cellulose acylate film together with the layers. A film. Moreover, as a commercial item, ZEONOR-ZF-14 (made by Nippon Zeon) and ARC270 (made by Nitto Denko Corporation) are mentioned.

2. Polarizers Polarizers include iodine polarizers, dye polarizers using dichroic dyes, and polyene polarizers. The iodine polarizer and the dye polarizer are generally produced using a polyvinyl alcohol film. Any polarizer may be used in the present invention.

3. Production method of polarizing plate The production method of the polarizing plate of the present invention is not particularly limited, and can be produced by a general method.
For example, first, a polyvinyl alcohol film is immersed and drawn in an iodine solution to produce a polarizer.
Next, two polymer films used as a protective film are surface-treated to improve the adhesion to the polarizer. The treated surface is bonded to the surface of the polarizer using an adhesive to obtain a polarizing plate.
When the polymer film has an in-plane slow axis, it is preferable to bond the polarizer with the absorption axis of the polarizer orthogonal to the in-plane slow axis of the polymer film.

When the polymer film is a cellulose acylate film, it is preferable to carry out an alkali saponification treatment in order to improve the adhesion to the polarizer. Further, instead of alkali saponification treatment, easy adhesion processing as described in JP-A-6-94915 and JP-A-6-118232 may be performed. Depending on the type of polymer film, corona discharge treatment, glow discharge treatment, flame treatment, acid treatment, and ultraviolet irradiation treatment are also effective.
Examples of the adhesive used for bonding the treated surface of the protective film 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 a protective film may be bonded to one surface of the polarizing plate and a separate film may be bonded to 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 cell. Moreover, a separate film is used in order to cover the adhesive layer bonded to a liquid crystal cell, and is used for the surface side which bonds a polarizing plate to a liquid crystal cell.

4). Liquid crystal display device The liquid crystal display device of the present invention is a liquid crystal display device using at least one polarizing plate of the present invention. The polarizing plate of the present invention can be used for liquid crystal cells in various display modes, such as TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), AFLC (Anti-ferroelectric Liquid Crystal), It can be used in combination with cells of various display modes such as OCB (Optically Compensatory Bend), STN (Supper Twisted Nematic), VA (Vertically Aligned), and HAN (Hybrid Aligned Nematic).

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

1. Production of protective film -1 Production of Protective Film A-1 (1) Cellulose Acylate Cellulose acylate having the types of acyl groups and the substitution degree shown in the following table was prepared. This was carried out by adding sulfuric acid (7.8 parts by mass with respect to 100 parts by mass of cellulose) as a catalyst, adding carboxylic acid as a raw material for the acyl substituent, and carrying out an acylation reaction at 40 ° C. At this time, the kind and substitution degree of the acyl group were adjusted by adjusting the kind and amount of the carboxylic acid. Moreover, it age | cure | ripened at 40 degreeC after acylation. Further, the low molecular weight component of the cellulose acylate was removed by washing with acetone.

(2) Dissolution <1-1> Cellulose Acetate Solution The following composition is put into a mixing tank, stirred to dissolve each component, further heated to 90 ° C. for about 10 minutes, and then a filter paper having an average pore size of 34 μm and an average pore size. Filtration through a 10 μm sintered metal filter.

―――――――――――――――――――――――――――――――――
Cellulose acetate solution ――――――――――――――――――――――――――――――――――
Cellulose acylate 100.0 parts by mass Triphenyl phosphate (TPP) 8.0 parts by mass Biphenyl diphenyl phosphate (BDP) 4.0 parts by mass Methylene chloride 403.0 parts by mass Methanol 60.2 parts by mass ――――――――――――――――――――――――――――

<1-2> Matting Agent Dispersion Next, the following composition containing the cellulose acetate solution prepared by the above method was charged into a dispersing machine to prepare a matting agent dispersion.

――――――――――――――――――――――――――――――――――
Matting agent dispersion ――――――――――――――――――――――――――――――――――
Silica particles having an average particle diameter of 16 nm (Aerosil R972 manufactured by Nippon Aerosil Co., Ltd. 2.0 parts by mass methylene chloride 72.4 parts by mass methanol 10.8 parts by mass cellulose acetate solution 10.3 parts by mass ――――――――――――――――――――――――――

<1-3> Additive solution Next, the following composition containing the cellulose acylate solution prepared by the above method was put into a mixing tank and dissolved by stirring while heating to prepare an additive solution.

―――――――――――――――――――――――――――――――――
Additive solution ―――――――――――――――――――――――――――――――――
Retardation agent (1) 20.0 parts by mass Methylene chloride 58.3 parts by mass Methanol 8.7 parts by mass Cellulose acetate solution 12.8 parts by mass ――――――――――――――――― ――――――――――――――――

100 parts by mass of the cellulose acylate solution, 1.35 parts by mass of the matting agent dispersion, and film formation so that the addition amount of the retardation enhancer (1) in the cellulose acetate film is as shown in the following table. A dope was prepared. The addition ratio of the additive is shown in parts by mass when the amount of cellulose acetate is 100 parts by mass.
Retardation expression agent (1)

  The above dope was cast using a band casting machine. The film peeled from the band with the residual solvent amount shown in the following table is stretched in the longitudinal direction at a stretch ratio of 5% in the section from stripping to the tenter, and then stretched in the width direction at a stretch ratio of 40% using the tenter. Then, the film was removed from the tenter after shrinking (relaxing) in the width direction at a magnification of 7% immediately after transverse stretching to form a cellulose acetate film. The residual solvent amount of the film when the tenter was removed was 55%. Both ends were cut off in front of the winding part to make a width of 2000 mm and wound up as a roll film having a length of 4000 m.

The produced cellulose acetate film was used as protective film A-1. This film had a thickness of 60 μm, a haze of 0.7%, and a moisture permeability of 60 ° C. and 95% RH was 1800 g / cm ² · day.

1. -2 Preparation of protective film A-2 Fujitac TD80UL (manufactured by FUJIFILM Corporation) was used as it was as protective film A-2. This film had a moisture permeability of 1300 g / cm ² · day at 60 ° C. and 95% RH.
1. -3 Preparation of Protective Film A-3 ZEONOR-ZF14 (manufactured by Nippon Zeon Co., Ltd.) was used as it was as the protective film A-3. This film had a water vapor transmission rate of 10 g / cm ² · day or less at 60 ° C. and 95% RH.

1. -4 Preparation of protective film B-1 (Preparation of sol solution a)
A stirrer, a reactor equipped with a reflux condenser, 120 parts of methyl ethyl ketone, 100 parts of acryloyloxypropyltrimethoxysilane (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), 3 parts of diisopropoxyaluminum ethyl acetoacetate were added and mixed. Thereafter, 30 parts of ion-exchanged water was added and reacted at 60 ° C. for 4 hours, and then cooled to room temperature to obtain sol solution a. The mass average molecular weight was 1600, and among the components higher than the oligomer component, the component having a molecular weight of 1000 to 20000 was 100%. Further, from the gas chromatography analysis, the raw material acryloyloxypropyltrimethoxysilane did not remain at all.

(Preparation of coating solution E for antiglare layer)
31 g of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (PET-30, manufactured by Nippon Kayaku Co., Ltd.) was diluted with 38 g of methyl isobutyl ketone. Furthermore, 1.5 g of a polymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) was added and mixed and stirred. Subsequently, 0.04 g of a fluorine-based surface modifier (FP-149) and 6.2 g of a silane coupling agent (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.) were added. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.520.
Finally, 30 of crosslinked poly (acryl-styrene) particles having an average particle diameter of 3.5 μm (copolymerization composition ratio = 50/50, refractive index 1.540) dispersed in this solution for 20 minutes at 10,000 rpm with a Polytron disperser. 39.0 g of% cyclohexanone dispersion was added to obtain a finished solution.
The mixed solution was filtered through a polypropylene filter having a pore diameter of 30 μm to prepare a coating solution E for an antiglare layer.

(Preparation of coating solution A for low refractive index layer)
Thermally crosslinkable fluorine-containing polymer having a refractive index of 1.44 containing polysiloxane and hydroxyl group (JTA113, solid content concentration 6%, manufactured by JSR Corporation) 13 g, colloidal silica dispersion MEK-ST-L (trade name, average) Particle size 45 nm, solid content concentration 30%, manufactured by Nissan Chemical Co., Ltd.) 1.3 g, the sol solution a 0.6 g, methyl ethyl ketone 5 g, and cyclohexanone 0.6 g were added, and after stirring, using a polypropylene filter with a pore size of 1 μm Filtration was performed to prepare a low refractive index layer coating solution A. The refractive index of the layer formed with this coating solution was 1.45.

(1) Coating of anti-glare layer A triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd.) having a thickness of 80 μm is unwound in a roll form and disclosed in [0172] of JP 2007-41495 A The coating solution E for the antiglare layer is applied by the die coating method shown in the apparatus configuration and application conditions described, dried at 30 ° C. for 15 seconds, 90 ° C. for 20 seconds, and further air-cooled metal halide of 160 W / cm under nitrogen purge Using a lamp (manufactured by Eye Graphics Co., Ltd.), the coating layer is cured by irradiating ultraviolet rays with an irradiation amount of 90 mJ / cm ² to form an anti-glare layer having a thickness of 6 μm and winding up. It was.

(2) Coating of low refractive index layer The triacetyl cellulose film coated with the antiglare layer coating liquid E and coated with the antiglare layer is unwound again to obtain the low refractive index layer coating liquid A. The coating was applied under the basic conditions described in [2007] of JP 2007-41495, dried at 120 ° C. for 150 seconds, further dried at 140 ° C. for 8 minutes, and then purged with nitrogen to an atmosphere having an oxygen concentration of 0.1% by volume. Under a 240 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.), an ultraviolet ray with an irradiation amount of 900 mJ / cm ² was irradiated to form a low refractive index layer having a thickness of 100 nm and wound up.

(3) Saponification treatment of antiglare antireflection film After the formation of the low refractive index layer, the sample was subjected to the following treatment.
A 1.5 mol / l aqueous sodium hydroxide solution was prepared and kept at 55 ° C. A 0.01 mol / l dilute sulfuric acid aqueous solution was prepared and kept at 35 ° C. The produced antiglare antireflection film was immersed in the aqueous sodium hydroxide solution for 2 minutes, and then immersed in water to sufficiently wash away the aqueous sodium hydroxide solution. Subsequently, after being immersed in the dilute sulfuric acid aqueous solution for 1 minute, it was immersed in water to sufficiently wash away the dilute sulfuric acid aqueous solution. Finally, the sample was thoroughly dried at 120 ° C.
In this manner, a saponified antiglare antireflection film was produced. This was used as protective film B-1. This film had a water permeability of 1000 g / cm ² · day at 60 ° C. and 95% RH.

1. -5 Preparation of Protective Film B-2 Fujitac TD80UL (manufactured by FUJIFILM Corporation) was used as it was as the protective film B-2. This film had a moisture permeability of 1300 g / cm ² · day at 60 ° C. and 95% RH.
1. -6 Preparation of protective film B-3 ARC270 (manufactured by Nitto Denko Corporation) was used as it was as the protective film B-3. This film had a water vapor transmission rate of 400 g / cm ² · day at 60 ° C. and 95% RH.

2. 1. Production of polarizing plate -1 Production of Polarizer A polyvinyl alcohol film having a thickness of 100 μm and an average polymerization degree of 2,400 was stretched 2.5 times in the transport direction while being immersed in pure water at 30 ° C. for 1 minute. Next, the film was stretched 1.2 times in the conveying direction while immersed in a dyeing bath containing iodine and potassium iodide at 30 ° C. for 1 minute. Next, the film was stretched twice while immersed in a 4% by mass boric acid bath at 60 ° C. for 2 minutes, and further immersed in a 5% by mass potassium iodide concentration 5% by mass bath for 5 seconds, and then at 35 ° C. for 5 minutes. It dried and produced the polarizer.

2. -2 Saponification treatment of protective film The surface of each produced protective film (however, the protective film B-1 was subjected to saponification treatment as described above) was saponified. Specifically, each protective film was immersed in a 1.5 mol / L sodium hydroxide aqueous solution at 55 ° C. for 2 minutes, and then neutralized, washed with water, and dried to perform saponification treatment.

2. -3 Production of Polarizing Plate A polarizing plate having the structure shown in FIG. 1 was produced. Using the polyvinyl alcohol film produced above as the polarizer 10, the protective film produced as any one of the produced protective films A-1 to A-3 and the second protective film 12b as the first protective film 12a. Using any one of B-1 to B-3, a PVA aqueous solution was used as an adhesive and bonding was performed to prepare a polarizing plate. The aqueous PVA paste solution was prepared by dissolving a commercially available 5% aqueous solution of completely saponified polyvinyl alcohol at 95 ° C. and then filtering off the insoluble matter.
The combinations of protective films are shown in the table below. In addition, as shown in FIG. 1, about the protective film which has an in-plane slow axis, it was bonded by making the direction orthogonal to the absorption axis of a polarizer.

3. Production and Evaluation of Liquid Crystal Display Device A liquid crystal display device having a configuration shown in FIG. 2 was produced using each produced polarizing plate. Specifically, the produced polarizing plates were bonded to the liquid crystal cell LC of Sharp LC20D10 in the following combination to produce a liquid crystal display device.

Next, about each produced liquid crystal display device, half was covered with the moisture-proof seed, and it was left to stand in the cellco of 20 degreeC98% RH for 100 hours.
Thereafter, the luminance Y and the hue u ′ were measured with BM5A (manufactured by TOPCON) for each of the portion covered with the moisture-proof sheet and the portion not covered, and the differences ΔY and Δu ′ were obtained. Each difference was judged according to the following criteria. The results are shown in the table below.
O 1 cd / m ² > ΔY and 0.0002> Δu ′
Δ5 cd / m ² >ΔY> 1 cd / m ² , 0.0005> Δu ′> 0.0002
× ΔY ≧ 5 cd / m ² , Δu ′> 0.0005

It is a cross-sectional schematic diagram of the polarizing plate produced in the Example. It is a cross-sectional schematic diagram of the liquid crystal display device produced in the Example.

Explanation of symbols

10 Polarizer 12a First protective film 12b Second protective film LC Liquid crystal cell

Claims (3)

It has at least a polarizer, a first protective film disposed on one surface of the polarizer, and a second protective film disposed on the other surface of the polarizer, the first protective film and the first 2. A polarizing plate, wherein the sum of moisture permeability at 60 ° C. and 95% RH of the protective film is 1500 g / m ² · day or more. A liquid crystal display device having at least a polarizing plate and a liquid crystal cell, wherein the polarizing plate includes a polarizer, a first protective film disposed on one surface of the polarizer, and the other of the polarizers. A second protective film disposed on the surface, and a sum of moisture permeability at 60 ° C. and 95% RH of the first protective film and the second protective film is 1500 g / m ² · day or more. A characteristic liquid crystal display device. The first protective film is disposed on the outside and the second protective film is disposed on the liquid crystal cell side. The moisture permeability of the first protective film at 60 ° C. and 95% RH is 400 g / m ² · day or more, and the second The liquid crystal display device according to claim 2, wherein the moisture permeability of the protective film at 60 ° C. and 95% RH is 1000 g / m ² · day or more.

Images