JP2008064941A - Polarizer protective film, its manufacturing method, and polarizer and liquid crystal display using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizer protective film which has a viewing angle characteristics not too large with less color changes, and also has an optical compensation function not producing uneveness such as frame-shaped uneven areas by the heat of the back light, and to provide its manufacturing method, a polarizer and a liquid crystal display using it. <P>SOLUTION: The polarizer protective film has an optical compensation function containing a thermoplastic resin and is 10-45 μm thick with Ro of 5-20nm and Rth of 70-120nm as expressed in the following expression. (i) Ro=(nx-ny)×d (ii) Rth=((nx+ny)/2-nz)×d, where nx represents the maximum refractive index of in the plane, ny refractive index in the direction of nx in the plane, nz refractive index in the film thickness direction, each being 590nm, and d denotes the film thickness (nm). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a polarizing plate protective film, a method for producing a polarizing plate protective film, and a polarizing plate and a liquid crystal display device using the same, having a viewing angle characteristic that is not too wide, little color change, and further, heat of a backlight, etc. The present invention relates to a polarizing plate protective film having no unevenness such as frame unevenness generated by the method, a method for producing a polarizing plate protective film, a polarizing plate using the same, and a liquid crystal display device.

  Twisted Nematic (hereinafter referred to as “rotating mode”) is used for notebook PCs and desktop monitors, because low power consumption, thinning, and low price are more important than video performance and ultra-wide viewing angle characteristics like LCD TVs. Many devices adopt the type drive system.

  However, since the TN type drive system has a very narrow viewing angle as it is, it is necessary to enlarge the viewing angle, and an optical compensation film coated, aligned and polymerized as shown in Patent Document 1 is used. ing. In recent years, the response speed of the TN system has also increased, and since it has been adopted in some liquid crystal TVs, there is an increasing demand for viewing angle expansion.

  However, these display devices do not always require the ultra-wide viewing angle characteristics as those of recent liquid crystal TVs, but rather have a viewing angle characteristic that is not too wide, and the yellowing of the color depending on the viewing angle may occur. Less is often preferred.

Further, in the TN type liquid crystal display device using the optical compensation film, when stress is generated when the polarizing film contracts due to the heat of the backlight due to the difference in the photoelastic coefficient between the cured layer of the discotic liquid crystal and the support. A frame-like light leak occurs, and this is a particularly serious problem especially when displaying black.
JP 2002-156527 A

  Accordingly, it is an object of the present invention to provide a polarizing plate protective film and a polarizing plate having an optical compensation function that has a viewing angle characteristic that is not too wide, has little color change, and has no unevenness in the frame caused by the heat of the backlight, etc. It is providing the manufacturing method of a protective film, a polarizing plate using the same, and a liquid crystal display device.

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

  1. A polarizing plate protective film having an optical compensation function containing a thermoplastic resin, wherein the thickness of the polarizing plate protective film is in the range of 10 to 45 μm, and Ro represented by the following formula is in the range of 5 to 20 nm. And Rth is in the range of 70 to 120 nm.

(I) Ro = (nx−ny) × d
(Ii) Rth = ((nx + ny) / 2−nz) × d
Where nx is the maximum refractive index in the plane, ny is the refractive index in the direction perpendicular to nx in the plane, nz is the refractive index in the film thickness direction, each refractive index is a value of 590 nm, and d is the film thickness of the film. (Nm).

  2. 2. The polarizing plate protective film as described in 1 above, wherein the polarizing plate protective film contains a cellulose ester.

  3. 3. The polarizing plate protective film according to 2, wherein the cellulose ester satisfies the following formula, where X is the acetyl group substitution degree and Y is the propionyl group substitution degree.

(Iii) 2.0 ≦ (X + Y) ≦ 2.6
(Iv) 0.1 ≦ Y ≦ 1.0
4). The polarizing plate protective film is a film that stretches 1.05 to 1.2 times in the transport direction or in the direction perpendicular to the transport direction, and the in-plane slow axis is substantially parallel to or substantially perpendicular to the transport direction. 4. The polarizing plate protective film according to any one of 1 to 3 above.

  5. 5. The method for producing a polarizing plate protective film, wherein the stretching described in 4 is performed using a tenter capable of independently controlling the web grip length (distance from the start of gripping to the end of gripping) left and right by the right and left gripping means. .

  6). 5. A polarizing plate using the polarizing plate protective film according to any one of 1 to 4 on at least one surface.

  7). 7. A liquid crystal display device using the polarizing plate according to 6 above, wherein the polarizing plate protective film is bonded to the liquid crystal cell side.

  8). 8. The liquid crystal display device according to 7, wherein the liquid crystal cell is a Twisted Nematic (hereinafter also referred to as TN) type liquid crystal cell.

  According to the present invention, there is provided a polarizing plate protective film having a viewing angle characteristic that is not too wide, having little color change, and further having an optical compensation function that has no unevenness such as unevenness of a frame caused by heat of a backlight, etc. A manufacturing method, a polarizing plate using the same, and a liquid crystal display device can be provided.

  The best mode for carrying out the present invention will be described in detail below, but the present invention is not limited thereto.

  The polarizing plate protective film of the present invention is a polarizing plate protective film having an optical compensation function containing a thermoplastic resin, wherein the thickness of the polarizing plate protective film is in the range of 10 to 45 μm, and is represented by the following formula: Ro is in the range of 5 to 20 nm, and Rth is in the range of 70 to 120 nm. With this configuration, the viewing angle characteristic is not too wide, the color change is small, and the backlight A polarizing plate protective film in which unevenness such as frame unevenness generated by heat or the like is improved is obtained.

  Here, the “polarizing plate protective film having an optical compensation function” is a film in which the polarizing plate protective film also serves as an optical compensation film, and refers to a film that is directly bonded to a polarizer via an adhesive or an adhesive.

(I) Ro = (nx−ny) × d
(Ii) Rth = ((nx + ny) / 2−nz) × d
Where nx is the maximum refractive index in the plane, ny is the refractive index in the direction perpendicular to nx in the plane, nz is the refractive index in the film thickness direction, each refractive index is a value of 590 nm, and d is the film thickness of the film. (Nm).

  As a result of diligent investigations in view of the above problems, the present inventors have made the polarizing plate protective film thinner, defined the range of retardation values, and further the cellulose ester having a specific total acyl group substitution degree, the draw ratio of the film It has been found that the above-mentioned effects are particularly excellent by controlling the above.

  In particular, with regard to stretching, the stretching ratio specified in the present invention is in a stretched region where unevenness is likely to occur, and a tenter that can independently control the gripping length of the web (distance from the start of gripping to the end of gripping) by left and right gripping means is used. It has also been found that extremely high-precision stretching is possible by performing the above.

  The present invention is described in further detail below.

(Thermoplastic resin)
Although it does not specifically limit as a thermoplastic resin which comprises the polarizing plate protective film of this invention, Although a cellulose ester, a polycarbonate, an acrylic resin, a cycloolefin polymer, polyester etc. are mentioned as a preferable example, it is not limited only to these. Absent.

Among these resins, the polarizing plate protective film of the present invention preferably contains a cellulose ester, and is preferably a cellulose ester film. (Hereinafter, the polarizing plate protective film of the present invention may be referred to as the cellulose ester film of the present invention.)
Hereinafter, the cellulose ester used in the present invention will be described.

  The cellulose ester film constituting the polarizing plate protective film preferably uses a lower fatty acid ester of cellulose. The lower fatty acid in the lower fatty acid ester of cellulose means a fatty acid having 6 or less carbon atoms. For example, cellulose acetate, cellulose propionate, cellulose butyrate and the like are preferable as the lower fatty acid ester of cellulose. In addition, mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate can be used. The most preferable lower fatty acid ester of cellulose has an acyl group having 2 to 4 carbon atoms as a substituent, and preferably satisfies the following formula when the substitution degree of acetyl group is X and the substitution degree of propionyl group is Y.

(Iii) 2.0 ≦ (X + Y) ≦ 2.6
(Iv) 0.1 ≦ Y ≦ 1.0
The portion not substituted with an acyl group usually exists as a hydroxyl group. These can be synthesized by known methods.

  These acyl group substitution degrees can be measured according to the method prescribed in ASTM-D817-96.

  The molecular weight of the cellulose ester used in the present invention is preferably a number average molecular weight (Mn) of 80,000 to 200,000. More preferred are 100,000 to 200,000, particularly preferably 150,000 to 200,000.

  In the cellulose ester used in the present invention, the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), Mw / Mn is preferably 1.4 to 3.0 as described above, and more preferably 1.7. It is the range of -2.2.

  The average molecular weight and molecular weight distribution of the cellulose ester can be measured by a known method using high performance liquid chromatography. Using this, the number average molecular weight and the weight average molecular weight can be calculated, and the ratio (Mw / Mn) can be calculated.

The measurement conditions are as follows.
Solvent: Methylene chloride column: Shodex K806, K805, K803G (used by connecting 3 products manufactured by Showa Denko KK)
Column temperature: 25 ° C
Sample concentration: 0.1% by mass
Detector: RI Model 504 (manufactured by GL Sciences)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0ml / min
Calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corp.) Mw = 100000-500 calibration curves with 13 samples were used. It is preferable to obtain 13 samples at approximately equal intervals.

  As the cellulose ester, cellulose ester synthesized from cotton linter, wood pulp, kenaf or the like as a raw material can be used alone or in combination. In particular, it is preferable to use a cotton linter (hereinafter sometimes simply referred to as a linter) or a cellulose ester synthesized from wood pulp alone or in combination.

  Moreover, the cellulose ester obtained from these can be mixed and used in arbitrary ratios, respectively. These cellulose esters are prepared by using an organic acid such as acetic acid or an organic solvent such as methylene chloride when sulfuric acid is used as the acylating agent (acetic anhydride, propionic anhydride, butyric anhydride). It can obtain by making it react by a conventional method using a protic catalyst like.

  In the case of acetylcellulose, it is necessary to extend the time for the acetylation reaction in order to increase the acetylation rate. However, if the reaction time is too long, the decomposition proceeds at the same time, and the polymer chain is broken and the acetyl group is decomposed, resulting in undesirable results. Therefore, it is necessary to set the reaction time within a certain range in order to increase the degree of acetylation and suppress decomposition to some extent. It is not appropriate to define the reaction time because the reaction conditions are various and greatly change depending on the reaction apparatus, equipment and other conditions. As the decomposition of the polymer progresses, the molecular weight distribution becomes wider. Therefore, in the case of cellulose ester, the degree of decomposition can be defined by the value of weight average molecular weight (Mw) / number average molecular weight (Mn) that is usually used. That is, in the process of acetylation of cellulose triacetate, the weight average molecular weight is used as one index of the reaction degree for allowing the acetylation reaction to be carried out for a sufficient time for acetylation without being too long and being decomposed too much. The value of (Mw) / number average molecular weight (Mn) can be used.

  An example of a method for producing a cellulose ester is shown below: 100 parts by mass of a flocculent linter was crushed as a cellulose raw material, 40 parts by mass of acetic acid was added, and pretreatment activation was performed at 36 ° C. for 20 minutes. Thereafter, 8 parts by mass of sulfuric acid, 260 parts by mass of acetic anhydride and 350 parts by mass of acetic acid were added, and esterification was performed at 36 ° C. for 120 minutes. After neutralization with 11 parts by mass of a 24% magnesium acetate aqueous solution, saponification aging was carried out at 63 ° C. for 35 minutes to obtain acetylcellulose. This was stirred for 160 minutes at room temperature using a 10-fold acetic acid aqueous solution (acetic acid: water = 1: 1 (mass ratio)), then filtered and dried to obtain purified acetylcellulose having an acetyl substitution degree of 2.75. . This acetylcellulose had Mn of 92000, Mw of 156000, and Mw / Mn of 1.7. Similarly, cellulose esters having different degrees of substitution and Mw / Mn ratios can be synthesized by adjusting the esterification conditions (temperature, time, stirring) and hydrolysis conditions of the cellulose ester.

  The synthesized cellulose ester is preferably purified to remove low molecular weight components or to remove unacetylated or low acetylated components by filtration.

  In the case of mixed acid cellulose ester, it can be obtained by the method described in JP-A-10-45804. The measuring method of the substitution degree of an acyl group can be measured according to the provisions of ASTM-D817-96.

  Cellulose esters are also affected by trace metal components in cellulose esters. These are considered to be related to water used in the production process, but it is preferable that there are few components that can become insoluble nuclei, and metal ions such as iron, calcium, and magnesium contain organic acidic groups. Insoluble matter may be formed by salt formation with a polymer degradation product or the like that may be present, and it is preferable that the amount is small. The iron (Fe) component is preferably 1 ppm or less. About calcium (Ca) component, it is contained in a lot of ground water and river water, etc., and it becomes hard water, and it is unsuitable as drinking water. Coordination compounds with ligands, that is, complexes are easily formed, and scum (insoluble starch, turbidity) derived from many insoluble calcium is formed.

  The calcium (Ca) component is 60 ppm or less, preferably 0 to 30 ppm. The magnesium (Mg) component is preferably in the range of 0 to 70 ppm, particularly preferably 0 to 20 ppm, since too much will cause insoluble matter. Metal components such as iron (Fe) content, calcium (Ca) content, magnesium (Mg) content, etc. are pre-processed by completely digesting cellulose ester with micro digest wet cracking equipment (sulfuric acid decomposition) and alkali melting. After performing, it can obtain | require by performing an analysis using ICP-AES (inductively coupled plasma emission spectroscopy analyzer).

<Plasticizer>
The plasticizer is not particularly limited, but preferably at least a plasticizer selected from a polyhydric alcohol ester plasticizer, a phthalate ester, a citrate ester, a fatty acid ester, a glycolate plasticizer, a polycarboxylic acid ester, and the like. It is preferable to include 1 type. Of these, at least one is preferably a polyhydric alcohol ester plasticizer.

  The polyhydric alcohol ester plasticizer is a plasticizer comprising an ester of a dihydric or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule. Preferably it is a 2-20 valent aliphatic polyhydric alcohol ester.

  The polyhydric alcohol used in the present invention is represented by the following general formula (1).

Formula (1) R1- (OH) n
However, R1 represents an n-valent organic group, n represents a positive integer of 2 or more, and the OH group represents an alcoholic and / or phenolic hydroxyl group.

  Examples of preferred polyhydric alcohols include the following, but the present invention is not limited to these. Adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3- Butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane- Examples include 1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, and xylitol. In particular, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylolpropane, and xylitol are preferable.

  There is no restriction | limiting in particular as monocarboxylic acid used for the polyhydric alcohol ester of this invention, Well-known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid, etc. can be used. Use of an alicyclic monocarboxylic acid or aromatic monocarboxylic acid is preferred in terms of improving moisture permeability and retention.

  Examples of preferred monocarboxylic acids include the following, but the present invention is not limited thereto.

  As the aliphatic monocarboxylic acid, a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. The number of carbon atoms is more preferably 1-20, and particularly preferably 1-10. When acetic acid is contained, the compatibility with the cellulose ester is increased, and it is also preferable to use a mixture of acetic acid and another monocarboxylic acid.

  Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanoic acid, undecylic acid, lauric acid, tridecylic acid, Saturated fatty acids such as myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, laccelic acid, undecylenic acid, olein Examples thereof include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid.

  Examples of preferable alicyclic monocarboxylic acids include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, and derivatives thereof.

  Examples of preferred aromatic monocarboxylic acids include those in which an alkyl group is introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, and two or more benzene rings such as biphenylcarboxylic acid, naphthalenecarboxylic acid, and tetralincarboxylic acid. The aromatic monocarboxylic acid which has, or those derivatives can be mentioned. Benzoic acid is particularly preferable.

  The molecular weight of the polyhydric alcohol ester is not particularly limited, but is preferably 300 to 1500, and more preferably 350 to 750. A higher molecular weight is preferred because it is less likely to volatilize, and a smaller one is preferred in terms of moisture permeability and compatibility with cellulose ester.

  The carboxylic acid used for the polyhydric alcohol ester may be one kind or a mixture of two or more kinds. Moreover, all the OH groups in the polyhydric alcohol may be esterified, or a part of the OH groups may be left as they are.

  Below, the specific compound of a polyhydric alcohol ester is illustrated.

  The glycolate plasticizer is not particularly limited, but alkylphthalylalkyl glycolates can be preferably used. Examples of alkyl phthalyl alkyl glycolates include methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, octyl phthalyl octyl glycolate, methyl phthalyl ethyl Glycolate, ethyl phthalyl methyl glycolate, ethyl phthalyl propyl glycolate, methyl phthalyl butyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl methyl glycolate, butyl phthalyl ethyl glycolate, propyl phthalyl butyl glycol Butyl phthalyl propyl glycolate, methyl phthalyl octyl glycolate, ethyl phthalyl octyl glycolate, octyl phthalyl methyl glycolate, octyl phthalate Ethyl glycolate, and the like.

  Examples of the phthalate ester plasticizer include diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, and dicyclohexyl terephthalate.

  Examples of the citrate plasticizer include acetyl trimethyl citrate, acetyl triethyl citrate, and acetyl tributyl citrate.

  Examples of fatty acid ester plasticizers include butyl oleate, methylacetyl ricinoleate, and dibutyl sebacate.

  Polycarboxylic acid ester plasticizers can also be preferably used. Specifically, it is preferable to add the polyvalent carboxylic acid ester described in paragraphs [0015] to [0020] of JP-A No. 2002-265639 as one of the plasticizers.

  Examples of the phosphate ester plasticizer include triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate and the like.

  The polyester plasticizer is not particularly limited, but a polyester plasticizer having an aromatic ring or a cycloalkyl ring in the molecule can be preferably used. Although it does not specifically limit as a preferable polyester plasticizer, For example, the aromatic terminal ester plasticizer represented by following General formula (2) is preferable.

General formula (2) B- (GA) n-GB
(In the formula, B is a benzene monocarboxylic acid residue, G is an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms, A represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 1 or more.)
In the general formula (2), a benzene monocarboxylic acid residue represented by B and an alkylene glycol residue, oxyalkylene glycol residue or aryl glycol residue represented by G, an alkylene dicarboxylic acid residue or aryl dicarboxylic group represented by A It is composed of an acid residue and can be obtained by a reaction similar to that of a normal polyester plasticizer.

  Examples of the benzene monocarboxylic acid component of the polyester plasticizer used in the present invention include benzoic acid, para-tert-butylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, dimethylbenzoic acid, ethylbenzoic acid, and normalpropyl. There exist benzoic acid, aminobenzoic acid, acetoxybenzoic acid, etc., and these can be used as 1 type, or 2 or more types of mixtures, respectively.

  Examples of the alkylene glycol component having 2 to 12 carbon atoms of the polyester plasticizer include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1, 2-propanediol, 2-methyl 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2,2 -Diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3propanediol (3,3-dimethylolheptane), 3-methyl-1, 5-pentanediol 1,6-hexanediol, 2,2,4-trimethyl 1,3-pentanediol, 2-ethyl 1, -Hexanediol, 2-methyl 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, etc., and these glycols are one kind or two kinds or more Used as a mixture. In particular, an alkylene glycol having 2 to 12 carbon atoms is particularly preferable because of excellent compatibility with a cellulose ester.

  Examples of the oxyalkylene glycol component having 4 to 12 carbon atoms of the aromatic terminal ester include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol. Or it can be used as a mixture of two or more.

  Examples of the alkylene dicarboxylic acid component having 4 to 12 carbon atoms of the aromatic terminal ester include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid. These are used as one kind or a mixture of two or more kinds. Examples of the arylene dicarboxylic acid component having 6 to 12 carbon atoms include phthalic acid, terephthalic acid, isophthalic acid, 1,5 naphthalene dicarboxylic acid, and 1,4 naphthalene dicarboxylic acid.

  The polyester plasticizer that can be used in the present invention has a number average molecular weight of preferably 300 to 1500, more preferably 400 to 1000. The acid value is preferably 0.5 mgKOH / g or less, the hydroxyl value is 25 mgKOH / g or less, more preferably the acid value is 0.3 mgKOH / g or less, and the hydroxyl value is 15 mgKOH / g or less.

  Hereinafter, synthesis examples of the aromatic terminal ester plasticizer will be shown.

<Sample No. 1 (Aromatic terminal ester sample)>
A reaction vessel was charged with 410 parts of phthalic acid, 610 parts of benzoic acid, 737 parts of dipropylene glycol, and 0.40 part of tetraisopropyl titanate as a catalyst. While refluxing the monohydric alcohol, heating was continued at 130 to 250 ° C. until the acid value became 2 or less, and water produced was continuously removed. Subsequently, the distillate was removed at 200 to 230 ° C. under a reduced pressure of 100 to finally 4 × 10 2 Pa or less, followed by filtration to obtain an aromatic terminal ester plasticizer having the following properties.

Viscosity (25 ° C., mPa · s); 43400
Acid value: 0.2
<Sample No. 2 (Aromatic terminal ester sample)>
Sample No. 1 was used except that 410 parts of phthalic acid, 610 parts of benzoic acid, 341 parts of ethylene glycol, and 0.35 part of tetraisopropyl titanate as a catalyst were used in the reaction vessel. In the same manner as in No. 1, an aromatic terminal ester having the following properties was obtained.

Viscosity (25 ° C., mPa · s); 31000
Acid value: 0.1
<Sample No. 3 (Aromatic terminal ester sample)>
Sample No. 1 was used except that 410 parts of phthalic acid, 610 parts of benzoic acid, 418 parts of 1,2-propanediol, and 0.35 part of tetraisopropyl titanate as the catalyst were used in the reaction vessel. In the same manner as in No. 1, an aromatic terminal ester having the following properties was obtained.

Viscosity (25 ° C., mPa · s); 38000
Acid value: 0.05
<Sample No. 4 (Aromatic terminal ester sample)>
Sample No. 4 was used except that 410 parts of phthalic acid, 610 parts of benzoic acid, 418 parts of 1,3-propanediol, and 0.35 part of tetraisopropyl titanate as a catalyst were used in the reaction vessel. In the same manner as in No. 1, an aromatic terminal ester having the following properties was obtained.

Viscosity (25 ° C., mPa · s); 37000
Acid value: 0.05
Although the specific compound of an aromatic terminal ester plasticizer is shown below, this invention is not limited to this.

  The total content of the plasticizer in the cellulose ester film is preferably 5 to 30% by mass with respect to the total solid content. Furthermore, 5-20 mass% is preferable, 6-16 mass% is more preferable, Especially preferably, it is 8-13 mass%. The contents of the two kinds of plasticizers are each at least 1% by mass, preferably 2% by mass or more.

  The polyhydric alcohol ester plasticizer is preferably contained in an amount of 1 to 12% by mass, particularly preferably 3 to 11% by mass. If the amount is too small, deterioration of flatness is recognized, and if it is too much, bleeding out tends to occur. The mass ratio between the polyhydric alcohol ester plasticizer and the other plasticizer is preferably in the range of 1: 4 to 4: 1, more preferably 1: 3 to 3: 1. If the amount of the plasticizer added is too large or too small, the film is liable to be deformed, which is not preferable.

<Ultraviolet absorber>
The polarizing plate protective film according to the present invention preferably contains an ultraviolet absorber. The ultraviolet absorber is intended to improve durability by absorbing ultraviolet rays of 400 nm or less, and is particularly preferably added so that the transmittance at a wavelength of 370 nm is 10% or less. Is 5% or less, more preferably 2% or less.

  Although the ultraviolet absorber used in the present invention is not particularly limited, for example, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, nickel complex compounds, inorganic powders Examples include the body.

  For example, 5-chloro-2- (3,5-di-sec-butyl-2-hydroxylphenyl) -2H-benzotriazole, (2-2H-benzotriazol-2-yl) -6- (linear and side Chain dodecyl) -4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone, etc., and tinuvin 109, tinuvin 171, tinuvin 234, tinuvin 326, tinuvin 327, tinuvin 328, etc. These are commercially available products manufactured by Ciba Specialty Chemicals and can be preferably used.

  For example, as the benzotriazole ultraviolet absorber, a compound represented by the following general formula (A) can be used.

In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ may be the same or different, and are a hydrogen atom, halogen atom, nitro group, hydroxyl group, alkyl group, alkenyl group, aryl group, alkoxyl group, acyloxy Represents a group, aryloxy group, alkylthio group, arylthio group, mono- or dialkylamino group, acylamino group or 5- to 6-membered heterocyclic group, and R ₄ and R ₅ are closed to form a 5- to 6-membered carbocyclic ring May be.

  Moreover, these groups described above may have an arbitrary substituent.

  Although the specific example of the ultraviolet absorber which concerns on this invention is given to the following, this invention is not limited to these.

UV-1: 2- (2'-hydroxy-5'-methylphenyl) benzotriazole UV-2: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole UV-3 : 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole UV-4: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl)- 5-Chlorobenzotriazole UV-5: 2- (2'-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl) benzotriazole UV-6: 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol)
UV-7: 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole UV-8: 2- (2H-benzotriazol-2-yl) -6 (Linear and side chain dodecyl) -4-methylphenol (TINUVIN171, manufactured by Ciba)
UV-9: Octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl- Mixture of 4-hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate (TINUVIN 109, manufactured by Ciba)
Furthermore, the ultraviolet absorber preferably used in the present invention includes a benzophenone ultraviolet absorber and a triazine ultraviolet absorber.

  As the benzophenone-based ultraviolet absorber, a compound represented by the following general formula (B) is preferably used.

In the formula, Y represents a hydrogen atom, a halogen atom or an alkyl group, an alkenyl group, an alkoxyl group, and a phenyl group, and these alkyl group, alkenyl group, and phenyl group may have a substituent. A represents a hydrogen atom, an alkyl group, an alkenyl group, a phenyl group, a cycloalkyl group, an alkylcarbonyl group, an alkylsulfonyl group or a —CO (NH) _n-1 —D group, and D represents an alkyl group, an alkenyl group or a substituent. Represents a phenyl group which may have m and n represent 1 or 2.

  In the above, the alkyl group represents, for example, a linear or branched aliphatic group having up to 24 carbon atoms, the alkoxyl group represents, for example, an alkoxyl group having up to 18 carbon atoms, and the alkenyl group has, for example, carbon number An alkenyl group up to 16 represents an allyl group, a 2-butenyl group, or the like. In addition, as substituents to alkyl groups, alkenyl groups, and phenyl groups, halogen atoms such as chlorine atoms, bromine atoms, fluorine atoms, etc., hydroxyl groups, phenyl groups (this phenyl group is substituted with alkyl groups or halogen atoms, etc.) May be used).

  Specific examples of the benzophenone compound represented by the general formula (B) are shown below, but the present invention is not limited thereto.

UV-10: 2,4-dihydroxybenzophenone UV-11: 2,2'-dihydroxy-4-methoxybenzophenone UV-12: 2-hydroxy-4-methoxy-5-sulfobenzophenone UV-13: Bis (2-methoxy -4-hydroxy-5-benzoylphenylmethane)
These additives are preferably contained in an amount of 0.2 to 30% by mass, particularly preferably 1 to 20% by mass with respect to the polarizing plate protective film.

  Moreover, the compound which has a 1,3,5- triazine ring can be used especially preferable as a ultraviolet absorber of the polarizing plate protective film of this invention, and a retardation regulator.

  Among them, the compound having a 1,3,5-triazine ring is preferably a compound represented by the following general formula (R).

In the general formula (R), X ¹ is a single bond, —NR ₄ —, —O— or —S—; X ² is a single bond, —NR ₅ —, —O— or —S—; X ³ is a single bond, —NR ₆ —, —O— or —S—; R ¹ , R ² and R ³ are an alkyl group, an alkenyl group, an aryl group or a heterocyclic group; and R ₄ , R ₅ and R ₆ are a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group. The compound represented by the general formula (R) is particularly preferably a melamine compound.

In the melamine compound, in the general formula (R), X ¹ , X ² and X ³ are —NR ₄ —, —NR ₅ — and —NR ₆ —, respectively, or X ¹ , X ² and X 3 ³ is a single bond, and R ¹ , R ² and R ³ are heterocyclic groups having a free valence on the nitrogen atom. ^{-X 1 -R 1, -X 2 -R} 2 and -X ³ -R ³ are preferably the same substituents. R ¹ , R ² and R ³ are particularly preferably aryl groups. R ₄ , R ₅ and R ₆ are particularly preferably a hydrogen atom.

  The alkyl group is preferably a chain alkyl group rather than a cyclic alkyl group. A linear alkyl group is preferred to a branched alkyl group.

  The number of carbon atoms of the alkyl group is preferably 1-30, more preferably 1-20, still more preferably 1-10, still more preferably 1-8, 6 is most preferred. The alkyl group may have a substituent.

  Specific examples of the substituent include a halogen atom, an alkoxy group (for example, each group such as methoxy, ethoxy, and epoxyethyloxy) and an acyloxy group (for example, acryloyloxy, methacryloyloxy). The alkenyl group is preferably a chain alkenyl group rather than a cyclic alkenyl group. A linear alkenyl group is preferable to a branched chain alkenyl group. The number of carbon atoms in the alkenyl group is preferably 2 to 30, more preferably 2 to 20, still more preferably 2 to 10, still more preferably 2 to 8, 6 is most preferred. The alkenyl group may have a substituent.

  Specific examples of the substituent include a halogen atom, an alkoxy group (for example, each group such as methoxy, ethoxy, and epoxyethyloxy) or an acyloxy group (for example, each group such as acryloyloxy and methacryloyloxy).

  The aryl group is preferably a phenyl group or a naphthyl group, and particularly preferably a phenyl group. The aryl group may have a substituent.

  Specific examples of the substituent include, for example, a halogen atom, hydroxyl, cyano, nitro, carboxyl, alkyl group, alkenyl group, aryl group, alkoxy group, alkenyloxy group, aryloxy group, acyloxy group, alkoxycarbonyl group, alkenyloxy Carbonyl group, aryloxycarbonyl group, sulfamoyl, alkyl-substituted sulfamoyl group, alkenyl-substituted sulfamoyl group, aryl-substituted sulfamoyl group, sulfonamido group, carbamoyl, alkyl-substituted carmoyl group, alkenyl-substituted carbamoyl group, aryl-substituted carbamoyl group, amide group, alkylthio Groups, alkenylthio groups, arylthio groups and acyl groups are included. The said alkyl group is synonymous with the alkyl group mentioned above.

  The alkyl group of the alkoxy group, acyloxy group, alkoxycarbonyl group, alkyl-substituted sulfamoyl group, sulfonamido group, alkyl-substituted carbamoyl group, amide group, alkylthio group and acyl group is also synonymous with the alkyl group described above.

  The said alkenyl group is synonymous with the alkenyl group mentioned above.

  The alkenyl part of the alkenyloxy group, acyloxy group, alkenyloxycarbonyl group, alkenyl-substituted sulfamoyl group, sulfonamide group, alkenyl-substituted carbamoyl group, amide group, alkenylthio group and acyl group is also synonymous with the alkenyl group described above.

  Specific examples of the aryl group include phenyl, α-naphthyl, β-naphthyl, 4-methoxyphenyl, 3,4-diethoxyphenyl, 4-octyloxyphenyl, and 4-dodecyloxyphenyl. Can be mentioned.

  Examples of the aryloxy group, acyloxy group, aryloxycarbonyl group, aryl-substituted sulfamoyl group, sulfonamido group, aryl-substituted carbamoyl group, amide group, arylthio group, and acyl group are the same as the above aryl group.

When X ¹ , X ² or X ³ is —NR—, —O— or —S—, the heterocyclic group preferably has aromaticity.

  The heterocyclic ring in the heterocyclic group having aromaticity is generally an unsaturated heterocyclic ring, preferably a heterocyclic ring having the largest number of double bonds. The heterocyclic ring is preferably a 5-membered ring, a 6-membered ring or a 7-membered ring, more preferably a 5-membered ring or a 6-membered ring, and most preferably a 6-membered ring.

  The hetero atom in the heterocyclic ring is preferably each atom such as N, S or O, and particularly preferably an N atom.

  As the heterocyclic ring having aromaticity, a pyridine ring (as the heterocyclic group, for example, each group such as 2-pyridyl or 4-pyridyl) is particularly preferable. The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group are the same as the examples of the substituent of the aryl moiety.

When X ¹ , X ² or X ³ is a single bond, the heterocyclic group is preferably a heterocyclic group having a free valence on the nitrogen atom. The heterocyclic group having a free valence on the nitrogen atom is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and a 5-membered ring. Is most preferred. The heterocyclic group may have a plurality of nitrogen atoms.

  Moreover, the hetero atom in a heterocyclic group may have hetero atoms other than a nitrogen atom (for example, O atom, S atom). The heterocyclic group may have a substituent. Specific examples of the substituent of the heterocyclic group are the same as the specific examples of the substituent of the aryl moiety.

  Specific examples of the heterocyclic group having a free valence on the nitrogen atom are shown below.

  The molecular weight of the compound having a 1,3,5-triazine ring is preferably 300 to 2,000. The boiling point of the compound is preferably 260 ° C. or higher. The boiling point can be measured using a commercially available measuring device (for example, TG / DTA100, manufactured by Seiko Electronics Industry Co., Ltd.).

  Specific examples of the compound having a 1,3,5-triazine ring are shown below.

  In addition, several R shown below represents the same group.

(1) Butyl (2) 2-Methoxy-2-ethoxyethyl (3) 5-Undecenyl (4) Phenyl (5) 4-Ethoxycarbonylphenyl (6) 4-Butoxyphenyl (7) p-Biphenylyl (8) 4 -Pyridyl (9) 2-naphthyl (10) 2-methylphenyl (11) 3,4-dimethoxyphenyl (12) 2-furyl

(14) phenyl (15) 3-ethoxycarbonylphenyl (16) 3-butoxyphenyl (17) m-biphenylyl (18) 3-phenylthiophenyl (19) 3-chlorophenyl (20) 3-benzoylphenyl (21) 3 -Acetoxyphenyl (22) 3-benzoyloxyphenyl (23) 3-phenoxycarbonylphenyl (24) 3-methoxyphenyl (25) 3-anilinophenyl (26) 3-isobutyrylaminophenyl (27) 3-phenoxy Carbonylaminophenyl (28) 3- (3-ethylureido) phenyl (29) 3- (3,3-diethylureido) phenyl (30) 3-methylphenyl (31) 3-phenoxyphenyl (32) 3-hydroxyphenyl (33) 4-Ethoxycarbonylphenyl (34) 4-butoxyphenyl (35) p-biphenylyl (36) 4-phenylthiophenyl (37) 4-chlorophenyl (38) 4-benzoylphenyl (39) 4-acetoxyphenyl (40) 4-benzoyloxyphenyl ( 41) 4-phenoxycarbonylphenyl (42) 4-methoxyphenyl (43) 4-anilinophenyl (44) 4-isobutyrylaminophenyl (45) 4-phenoxycarbonylaminophenyl (46) 4- (3-ethyl (Ureido) phenyl (47) 4- (3,3-diethylureido) phenyl (48) 4-methylphenyl (49) 4-phenoxyphenyl (50) 4-hydroxyphenyl (51) 3,4-diethoxycarbonylphenyl ( 52) 3,4-dibutoxyphenyl (53) 3 -Diphenylphenyl (54) 3,4-diphenylthiophenyl (55) 3,4-dichlorophenyl (56) 3,4-dibenzoylphenyl (57) 3,4-diacetoxyphenyl (58) 3,4-dibenzoyl Oxyphenyl (59) 3,4-diphenoxycarbonylphenyl (60) 3,4-dimethoxyphenyl (61) 3,4-dianilinophenyl (62) 3,4-dimethylphenyl (63) 3,4-diphenoxy Phenyl (64) 3,4-dihydroxyphenyl (65) 2-naphthyl (66) 3,4,5-triethoxycarbonylphenyl (67) 3,4,5-tributoxyphenyl (68) 3,4,5- Triphenylphenyl (69) 3,4,5-triphenylthiophenyl (70) 3,4,5-trichlorophenyl (71) 3,4,5-tribenzoylphenyl (72) 3,4,5-triacetoxyphenyl (73) 3,4,5-tribenzoyloxyphenyl (74) 3,4,5-triphenoxycarbonylphenyl (75) 3,4,5-trimethoxyphenyl (76) 3,4,5-trianilinophenyl (77) 3,4,5-trimethylphenyl (78) 3,4,5-triphenoxyphenyl (79 ) 3,4,5-trihydroxyphenyl

(80) phenyl (81) 3-ethoxycarbonylphenyl (82) 3-butoxyphenyl (83) m-biphenylyl (84) 3-phenylthiophenyl (85) 3-chlorophenyl (86) 3-benzoylphenyl (87) 3 -Acetoxyphenyl (88) 3-benzoyloxyphenyl (89) 3-phenoxycarbonylphenyl (90) 3-methoxyphenyl (91) 3-anilinophenyl (92) 3-isobutyrylaminophenyl (93) 3-phenoxy Carbonylaminophenyl (94) 3- (3-ethylureido) phenyl (95) 3- (3,3-diethylureido) phenyl (96) 3-methylphenyl (97) 3-phenoxyphenyl (98) 3-hydroxyphenyl (99) 4-Ethoxycarbonylphenyl (100) 4-butoxyphenyl (101) p-biphenylyl (102) 4-phenylthiophenyl (103) 4-chlorophenyl (104) 4-benzoylphenyl (105) 4-acetoxyphenyl (106) 4-benzoyloxyphenyl ( 107) 4-phenoxycarbonylphenyl (108) 4-methoxyphenyl (109) 4-anilinophenyl (110) 4-isobutyrylaminophenyl (111) 4-phenoxycarbonylaminophenyl (112) 4- (3-ethyl (Ureido) phenyl (113) 4- (3,3-diethylureido) phenyl (114) 4-methylphenyl (115) 4-phenoxyphenyl (116) 4-hydroxyphenyl (117) 3,4-diethoxycarbonylphenyl ( 118) 3 , 4-dibutoxyphenyl (119) 3,4-diphenylphenyl (120) 3,4-diphenylthiophenyl (121) 3,4-dichlorophenyl (122) 3,4-dibenzoylphenyl (123) 3,4- Diacetoxyphenyl (124) 3,4-dibenzoyloxyphenyl (125) 3,4-diphenoxycarbonylphenyl (126) 3,4-dimethoxyphenyl (127) 3,4-dianilinophenyl (128) 3,4 -Dimethylphenyl (129) 3,4-diphenoxyphenyl (130) 3,4-dihydroxyphenyl (131) 2-naphthyl (132) 3,4,5-triethoxycarbonylphenyl (133) 3,4,5- Tributoxyphenyl (134) 3,4,5-triphenylphenyl (135) 3 4,5-triphenylthiophenyl (136) 3,4,5-trichlorophenyl (137) 3,4,5-tribenzoylphenyl (138) 3,4,5-triacetoxyphenyl (139) 3,4 5-tribenzoyloxyphenyl (140) 3,4,5-triphenoxycarbonylphenyl (141) 3,4,5-trimethoxyphenyl (142) 3,4,5-trianilinophenyl (143) 3,4 , 5-trimethylphenyl (144) 3,4,5-triphenoxyphenyl (145) 3,4,5-trihydroxyphenyl

(146) phenyl (147) 4-ethoxycarbonylphenyl (148) 4-butoxyphenyl (149) p-biphenylyl (150) 4-phenylthiophenyl (151) 4-chlorophenyl (152) 4-benzoylphenyl (153) 4 -Acetoxyphenyl (154) 4-benzoyloxyphenyl (155) 4-phenoxycarbonylphenyl (156) 4-methoxyphenyl (157) 4-anilinophenyl (158) 4-isobutyrylaminophenyl (159) 4-phenoxy Carbonylaminophenyl (160) 4- (3-ethylureido) phenyl (161) 4- (3,3-diethylureido) phenyl (162) 4-methylphenyl (163) 4-phenoxyphenyl (164) 4-hydroxyphenyl

(165) phenyl (166) 4-ethoxycarbonylphenyl (167) 4-butoxyphenyl (168) p-biphenylyl (169) 4-phenylthiophenyl (170) 4-chlorophenyl (171) 4-benzoylphenyl (172) 4 -Acetoxyphenyl (173) 4-benzoyloxyphenyl (174) 4-phenoxycarbonylphenyl (175) 4-methoxyphenyl (176) 4-anilinophenyl (177) 4-isobutyrylaminophenyl (178) 4-phenoxy Carbonylaminophenyl (179) 4- (3-ethylureido) phenyl (180) 4- (3,3-diethylureido) phenyl (181) 4-methylphenyl (182) 4-phenoxyphenyl (183) 4-hydroxyphenyl

(184) phenyl (185) 4-ethoxycarbonylphenyl (186) 4-butoxyphenyl (187) p-biphenylyl (188) 4-phenylthiophenyl (189) 4-chlorophenyl (190) 4-benzoylphenyl (191) 4 -Acetoxyphenyl (192) 4-benzoyloxyphenyl (193) 4-phenoxycarbonylphenyl (194) 4-methoxyphenyl (195) 4-anilinophenyl (196) 4-isobutyrylaminophenyl (197) 4-phenoxy Carbonylaminophenyl (198) 4- (3-ethylureido) phenyl (199) 4- (3,3-diethylureido) phenyl (200) 4-methylphenyl (201) 4-phenoxyphenyl (202) 4-hydroxyphenyl

(203) phenyl (204) 4-ethoxycarbonylphenyl (205) 4-butoxyphenyl (206) p-biphenylyl (207) 4-phenylthiophenyl (208) 4-chlorophenyl (209) 4-benzoylphenyl (210) 4 -Acetoxyphenyl (211) 4-benzoyloxyphenyl (212) 4-phenoxycarbonylphenyl (213) 4-methoxyphenyl (214) 4-anilinophenyl (215) 4-isobutyrylaminophenyl (216) 4-phenoxy Carbonylaminophenyl (217) 4- (3-ethylureido) phenyl (218) 4- (3,3-diethylureido) phenyl (219) 4-methylphenyl (220) 4-phenoxyphenyl (221) 4-hydroxyphenyl

(222) phenyl (223) 4-butylphenyl (224) 4- (2-methoxy-2-ethoxyethyl) phenyl (225) 4- (5-nonenyl) phenyl (226) p-biphenylyl (227) 4-ethoxy Carbonylphenyl (228) 4-butoxyphenyl (229) 4-methylphenyl (230) 4-chlorophenyl (231) 4-phenylthiophenyl (232) 4-benzoylphenyl (233) 4-acetoxyphenyl (234) 4-benzoyl Oxyphenyl (235) 4-phenoxycarbonylphenyl (236) 4-methoxyphenyl (237) 4-anilinophenyl (238) 4-isobutyrylaminophenyl (239) 4-phenoxycarbonylaminophenyl (240) 4- ( 3-ethylureido Phenyl (241) 4- (3,3-diethylureido) phenyl (242) 4-phenoxyphenyl (243) 4-hydroxyphenyl (244) 3-butylphenyl (245) 3- (2-methoxy-2-ethoxyethyl) ) Phenyl (246) 3- (5-nonenyl) phenyl (247) m-biphenylyl (248) 3-ethoxycarbonylphenyl (249) 3-butoxyphenyl (250) 3-methylphenyl (251) 3-chlorophenyl (252) 3-phenylthiophenyl (253) 3-benzoylphenyl (254) 3-acetoxyphenyl (255) 3-benzoyloxyphenyl (256) 3-phenoxycarbonylphenyl (257) 3-methoxyphenyl (258) 3-anilinophenyl (259) 3-I Butyrylaminophenyl (260) 3-phenoxycarbonylaminophenyl (261) 3- (3-ethylureido) phenyl (262) 3- (3,3-diethylureido) phenyl (263) 3-phenoxyphenyl (264) 3 -Hydroxyphenyl (265) 2-butylphenyl (266) 2- (2-methoxy-2-ethoxyethyl) phenyl (267) 2- (5-nonenyl) phenyl (268) o-biphenylyl (269) 2-ethoxycarbonyl Phenyl (270) 2-Butoxyphenyl (271) 2-Methylphenyl (272) 2-Chlorophenyl (273) 2-Phenylthiophenyl (274) 2-Benzoylphenyl (275) 2-Acetoxyphenyl (276) 2-Benzoyloxy Phenyl (277) 2 Phenoxycarbonylphenyl (278) 2-methoxyphenyl (279) 2-anilinophenyl (280) 2-isobutyrylaminophenyl (281) 2-phenoxycarbonylaminophenyl (282) 2- (3-ethylureido) phenyl ( 283) 2- (3,3-diethylureido) phenyl (284) 2-phenoxyphenyl (285) 2-hydroxyphenyl (286) 3,4-dibutylphenyl (287) 3,4-di (2-methoxy-2) -Ethoxyethyl) phenyl (288) 3,4-diphenylphenyl (289) 3,4-diethoxycarbonylphenyl (290) 3,4-didodecyloxyphenyl (291) 3,4-dimethylphenyl (292) 3, 4-dichlorophenyl (293) 3,4-dibenzoyl Enyl (294) 3,4-diacetoxyphenyl (295) 3,4-dimethoxyphenyl (296) 3,4-di-N-methylaminophenyl (297) 3,4-diisobutyrylaminophenyl (298) 3 , 4-diphenoxyphenyl (299) 3,4-dihydroxyphenyl (300) 3,5-dibutylphenyl (301) 3,5-di (2-methoxy-2-ethoxyethyl) phenyl (302) 3,5- Diphenylphenyl (303) 3,5-diethoxycarbonylphenyl (304) 3,5-didodecyloxyphenyl (305) 3,5-dimethylphenyl (306) 3,5-dichlorophenyl (307) 3,5-dibenzoyl Phenyl (308) 3,5-diacetoxyphenyl (309) 3,5-dimethoxyphenyl (3 0) 3,5-di-N-methylaminophenyl (311) 3,5-diisobutyrylaminophenyl (312) 3,5-diphenoxyphenyl (313) 3,5-dihydroxyphenyl (314) 2,4 -Dibutylphenyl (315) 2,4-di (2-methoxy-2-ethoxyethyl) phenyl (316) 2,4-diphenylphenyl (317) 2,4-diethoxycarbonylphenyl (318) 2,4-di Dodecyloxyphenyl (319) 2,4-dimethylphenyl (320) 2,4-dichlorophenyl (321) 2,4-dibenzoylphenyl (322) 2,4-diacetoxyphenyl (323) 2,4-dimethoxyphenyl ( 324) 2,4-di-N-methylaminophenyl (325) 2,4-diisobutyrylaminopheny (326) 2,4-diphenoxyphenyl (327) 2,4-dihydroxyphenyl (328) 2,3-dibutylphenyl (329) 2,3-di (2-methoxy-2-ethoxyethyl) phenyl (330) 2,3-diphenylphenyl (331) 2,3-diethoxycarbonylphenyl (332) 2,3-didodecyloxyphenyl (333) 2,3-dimethylphenyl (334) 2,3-dichlorophenyl (335) 2, 3-dibenzoylphenyl (336) 2,3-diacetoxyphenyl (337) 2,3-dimethoxyphenyl (338) 2,3-di-N-methylaminophenyl (339) 2,3-diisobutyrylaminophenyl (340) 2,3-diphenoxyphenyl (341) 2,3-dihydroxyphenyl (342 2,6-dibutylphenyl (343) 2,6-di (2-methoxy-2-ethoxyethyl) phenyl (344) 2,6-diphenylphenyl (345) 2,6-diethoxycarbonylphenyl (346) 2, 6-didodecyloxyphenyl (347) 2,6-dimethylphenyl (348) 2,6-dichlorophenyl (349) 2,6-dibenzoylphenyl (350) 2,6-diacetoxyphenyl (351) 2,6- Dimethoxyphenyl (352) 2,6-di-N-methylaminophenyl (353) 2,6-diisobutyrylaminophenyl (354) 2,6-diphenoxyphenyl (355) 2,6-dihydroxyphenyl (356) 3,4,5-tributylphenyl (357) 3,4,5-tri (2-methoxy-2-ethoxy) Til) phenyl (358) 3,4,5-triphenylphenyl (359) 3,4,5-triethoxycarbonylphenyl (360) 3,4,5-tridodecyloxyphenyl (361) 3,4,5- Trimethylphenyl (362) 3,4,5-trichlorophenyl (363) 3,4,5-tribenzoylphenyl (364) 3,4,5-triacetoxyphenyl (365) 3,4,5-trimethoxyphenyl ( 366) 3,4,5-tri-N-methylaminophenyl (367) 3,4,5-triisobutyrylaminophenyl (368) 3,4,5-triphenoxyphenyl (369) 3,4,5 -Trihydroxyphenyl (370) 2,4,6-tributylphenyl (371) 2,4,6-tri (2-methoxy-2-ethoxyethyl) ) Phenyl (372) 2,4,6-triphenylphenyl (373) 2,4,6-triethoxycarbonylphenyl (374) 2,4,6-tridodecyloxyphenyl (375) 2,4,6-trimethyl Phenyl (376) 2,4,6-trichlorophenyl (377) 2,4,6-tribenzoylphenyl (378) 2,4,6-triacetoxyphenyl (379) 2,4,6-trimethoxyphenyl (380 ) 2,4,6-tri-N-methylaminophenyl (381) 2,4,6-triisobutyrylaminophenyl (382) 2,4,6-triphenoxyphenyl (383) 2,4,6- Trihydroxyphenyl (384) Pentafluorophenyl (385) Pentachlorophenyl (386) Pentamethoxyphenyl (38 ) 6-N-methylsulfamoyl-8-methoxy-2-naphthyl (388) 5-N-methylsulfamoyl-2-naphthyl (389) 6-N-phenylsulfamoyl-2-naphthyl (390) 5-Ethoxy-7-N-methylsulfamoyl-2-naphthyl (391) 3-methoxy-2-naphthyl (392) 1-ethoxy-2-naphthyl (393) 6-N-phenylsulfamoyl-8- Methoxy-2-naphthyl (394) 5-methoxy-7-N-phenylsulfamoyl-2-naphthyl (395) 1- (4-methylphenyl) -2-naphthyl (396) 6,8-di-N- Methylsulfamoyl-2-naphthyl (397) 6-N-2-acetoxyethylsulfamoyl-8-methoxy-2-naphthyl (398) 5-acetoxy-7- N-phenylsulfamoyl-2-naphthyl (399) 3-benzoyloxy-2-naphthyl (400) 5-acetylamino-1-naphthyl (401) 2-methoxy-1-naphthyl (402) 4-phenoxy-1 -Naphtyl (403) 5-N-methylsulfamoyl-1-naphthyl (404) 3-N-methylcarbamoyl-4-hydroxy-1-naphthyl (405) 5-methoxy-6-N-ethylsulfamoyl- 1-naphthyl (406) 7-tetradecyloxy-1-naphthyl (407) 4- (4-methylphenoxy) -1-naphthyl (408) 6-N-methylsulfamoyl-1-naphthyl (409) 3- N, N-dimethylcarbamoyl-4-methoxy-1-naphthyl (410) 5-methoxy-6-N-benzylsulfamoyl 1-naphthyl (411) 3,6-di-N-phenylsulfamoyl-1-naphthyl (412) methyl (413) ethyl (414) butyl (415) octyl (416) dodecyl (417) 2-butoxy-2 -Ethoxyethyl (418) benzyl (419) 4-methoxybenzyl

(424) Methyl (425) Phenyl (426) Butyl

(430) methyl (431) ethyl (432) butyl (433) octyl (434) dodecyl (435) 2-butoxy-2-ethoxyethyl (436) benzyl (437) 4-methoxybenzyl

  In the present invention, a melamine polymer may be used as the compound having a 1,3,5-triazine ring. The melamine polymer is preferably synthesized by a polymerization reaction between a melamine compound represented by the following general formula (M) and a carbonyl compound.

In the above synthetic reaction scheme, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group.

  The alkyl group, alkenyl group, aryl group, heterocyclic group, and substituents thereof have the same meanings as the groups and substituents described in the general formula (I).

  The polymerization reaction between the melamine compound and the carbonyl compound is the same as the method for synthesizing a normal melamine resin (for example, melamine formaldehyde resin). Moreover, you may use a commercially available melamine polymer (melamine resin).

  The molecular weight of the melamine polymer is preferably 2,000 to 400,000. Specific examples of the repeating unit of the melamine polymer are shown below.

MP-1: R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ : CH ₂ OH
^{MP-2: R 13, R} 14, R 15, R 16: CH 2 OCH 3
^{MP-3: R 13, R} 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-4: R 13, R} 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-5: R 13, R} 14, R 15, R 16: CH 2 NHCOCH = CH 2
^{MP-6: R 13, R} 14, R 15, R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-7: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 OCH 3
^{MP-8: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 OCH 3
^{MP-9: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 OCH 3
^{MP-10: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 OCH 3
^{MP-11: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 OCH 3
^{MP-12: R 13, R} 14, R 16: CH 2 OCH 3; R 15: CH 2 OH
^{MP-13: R 13, R} 16: CH 2 OCH 3; R 14, R 15: CH 2 OH
^{MP-14: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-i-C 4 H 9
^{MP-15: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-i-C 4 H 9
^{MP-16: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-17: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-i-C 4 H 9
^{MP-18: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-19: R 13, R} 14, R 16: CH 2 O-i-C 4 H 9; R 15: CH 2 OH
^{MP-20: R 13, R} 16: CH 2 O-i-C 4 H 9; R 14, R 15: CH 2 OH
MP-21: R ¹³ , R ¹⁴ , R ¹⁵ : CH ₂ OH; R ¹⁶ : CH _{2 On} -C ₄ H ₉
^{MP-22: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-23: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-24: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9
^{MP-25: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-26: R 13, R} 14, R 16: CH 2 O-n-C 4 H 9; R 15: CH 2 OH
^{MP-27: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-28: R 13, R} 14: CH 2 OH; R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-29: R 13, R} 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-30: R 13, R} 16: CH 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-31: R 13: CH} 2 OH; R 14, R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-32: R 13: CH} 2 OH; R 14, R 16: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-33: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-34: R 13: CH} 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-35: R 13, R} 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-36: R 13, R} 16: CH 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-37: R 13: CH} 2 OCH 3; R 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-38: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH
^{MP-39: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-40: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-41: R 13: CH} 2 OH; R 14: CH 2 O-n-C 4 H 9; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-42: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-43: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-44: R 13: CH} 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2
^{MP-45: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-46: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-47: R 13: CH} 2 OH; R 14: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-48: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-49: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-50: R 13: CH} 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2

^{MP-51: R 13, R} 14, R 15, R 16: CH 2 OH
^{MP-52: R 13, R} 14, R 15, R 16: CH 2 OCH 3
^{MP-53: R 13, R} 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-54: R 13, R} 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-55: R 13, R} 14, R 15, R 16: CH 2 NHCOCH = CH 2
^{MP-56: R 13, R} 14, R 15, R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-57: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 OCH 3
^{MP-58: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 OCH 3
^{MP-59: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 OCH 3
^{MP-60: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 OCH 3
^{MP-61: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 OCH 3
^{MP-62: R 13, R} 14, R 16: CH 2 OCH 3; R 15: CH 2 OH
^{MP-63: R 13, R} 16: CH 2 OCH 3; R 14, R 15: CH 2 OH
^{MP-64: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-i-C 4 H 9
^{MP-65: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-i-C 4 H 9
^{MP-66: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-67: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-i-C 4 H 9
^{MP-68: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-69: R 13, R} 14, R 16: CH 2 O-i-C 4 H 9; R 15: CH 2 OH
^{MP-70: R 13, R} 16: CH 2 O-i-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-71: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-72: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-73: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-74: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9
^{MP-75: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-76: R 13, R} 14, R 16: CH 2 O-n-C 4 H 9; R 15: CH 2 OH
^{MP-77: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-78: R 13, R} 14: CH 2 OH; R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-79: R 13, R} 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-80: R 13, R} 16: CH 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-81: R 13: CH} 2 OH; R 14, R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-82: R 13: CH} 2 OH; R 14, R 16: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-83: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-84: R 13: CH} 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-85: R 13, R} 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-86: R 13, R} 16: CH 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-87: R 13: CH} 2 OCH 3; R 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-88: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH
^{MP-89: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-90: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-91: R 13: CH} 2 OH; R 14: CH 2 O-n-C 4 H 9; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-92: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-93: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-94: R 13: CH} 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2
^{MP-95: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-96: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-97: R 13: CH} 2 OH; R 14: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-98: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-99: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-100: R 13: CH} 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2

^{MP-101: R 13, R} 14, R 15, R 16: CH 2 OH
^{MP-102: R 13, R} 14, R 15, R 16: CH 2 OCH 3
^{MP-103: R 13, R} 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-104: R 13, R} 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-105: R 13, R} 14, R 15, R 16: CH 2 NHCOCH = CH 2
^{MP-106: R 13, R} 14, R 15, R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-107: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 OCH 3
^{MP-108: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 OCH 3
^{MP-109: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 OCH 3
^{MP-110: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 OCH 3
^{MP-111: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 OCH 3
^{MP-112: R 13, R} 14, R 16: CH 2 OCH 3; R 15: CH 2 OH
^{MP-113: R 13, R} 16: CH 2 OCH 3; R 14, R 15: CH 2 OH
^{MP-114: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-i-C 4 H 9
^{MP-115: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-i-C 4 H 9
^{MP-116: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-117: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-i-C 4 H 9
^{MP-118: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-119: R 13, R} 14, R 16: CH 2 O-i-C 4 H 9; R 15: CH 2 OH
^{MP-120: R 13, R} 16: CH 2 O-i-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-121: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-122: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-123: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-124: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9
^{MP-125: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-126: R 13, R} 14, R 16: CH 2 O-n-C 4 H 9; R 15: CH 2 OH
^{MP-127: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-128: R 13, R} 14: CH 2 OH; R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-129: R 13, R} 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-130: R 13, R} 16: CH 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-131: R 13: CH} 2 OH; R 14, R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-132: R 13: CH} 2 OH; R 14, R 16: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-133: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-134: R 13: CH} 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-135: R 13, R} 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-136: R 13, R} 16: CH 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-137: R 13: CH} 2 OCH 3; R 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-138: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH
^{MP-139: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-140: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-141: R 13: CH} 2 OH; R 14: CH 2 O-n-C 4 H 9; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-142: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-143: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-144: R 13: CH} 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2
^{MP-145: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-146: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-147: R 13: CH} 2 OH; R 14: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-148: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-149: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-150: R 13: CH} 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2

^{MP-151: R 13, R} 14, R 15, R 16: CH 2 OH
^{MP-152: R 13, R} 14, R 15, R 16: CH 2 OCH 3
^{MP-153: R 13, R} 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-154: R 13, R} 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-155: R 13, R} 14, R 15, R 16: CH 2 NHCOCH = CH 2
^{MP-156: R 13, R} 14, R 15, R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-157: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 OCH 3
^{MP-158: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 OCH 3
^{MP-159: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 OCH 3
^{MP-160: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 OCH 3
^{MP-161: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 OCH 3
^{MP-162: R 13, R} 14, R 16: CH 2 OCH 3; R 15: CH 2 OH
^{MP-163: R 13, R} 16: CH 2 OCH 3; R 14, R 15: CH 2 OH
^{MP-164: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-i-C 4 H 9
^{MP-165: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-i-C 4 H 9
^{MP-166: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-167: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-i-C 4 H 9
^{MP-168: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-169: R 13, R} 14, R 16: CH 2 O-i-C 4 H 9; R 15: CH 2 OH
^{MP-170: R 13, R} 16: CH 2 O-i-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-171: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-172: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-173: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-174: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9
^{MP-175: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-n-C 4 H 9
MP-176: R ¹³ , R ¹⁴ , R ¹⁶ : CH _{2 On} -C ₄ H ₉ ; R ¹⁵ : CH ₂ OH
^{MP-177: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-178: R 13, R} 14: CH 2 OH; R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-179: R 13, R} 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-180: R 13, R} 16: CH 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-181: R 13: CH} 2 OH; R 14, R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-182: R 13: CH} 2 OH; R 14, R 16: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-183: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-184: R 13: CH} 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-185: R 13, R} 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-186: R 13, R} 16: CH 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-187: R 13: CH} 2 OCH 3; R 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-188: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH
^{MP-189: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-190: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-191: R 13: CH} 2 OH; R 14: CH 2 O-n-C 4 H 9; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-192: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-193: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-194: R 13: CH} 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2
^{MP-195: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-196: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-197: R 13: CH} 2 OH; R 14: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-198: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-199: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-200: R 13: CH} 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2
In the present invention, a copolymer obtained by combining two or more of the above repeating units may be used. Two or more homopolymers or copolymers may be used in combination.

  Moreover, you may use together the compound which has a 2 or more types of 1,3,5- triazine ring. Two or more kinds of discotic compounds (for example, a compound having a 1,3,5-triazine ring and a compound having a porphyrin skeleton) may be used in combination.

  Moreover, the triazine type compound shown by general formula (I) of Unexamined-Japanese-Patent No. 2001-235621 is also preferably used for the cellulose ester film which concerns on this invention.

  The cellulose ester film according to the present invention preferably contains two or more ultraviolet absorbers.

  As the UV absorber, a polymer UV absorber can be preferably used, and in particular, a polymer type UV absorber described in JP-A-6-148430 is preferably used.

  The method for adding the UV absorber is to add the UV absorber to the dope after dissolving the UV absorber in an alcohol such as methanol, ethanol or butanol, an organic solvent such as methylene chloride, methyl acetate, acetone or dioxolane, or a mixed solvent thereof. Or you may add directly in dope composition. For an inorganic powder that does not dissolve in an organic solvent, a dissolver or a sand mill is used in the organic solvent and cellulose ester to disperse and then added to the dope.

  The amount of the UV absorber used is not uniform depending on the type of UV absorber, the operating conditions, etc., but when the dry film thickness of the cellulose ester film is 30 to 200 μm, it is 0.5 to 10 with respect to the cellulose ester film. % By mass is preferred, 0.5-4% by mass is more preferred, and 0.6-2% by mass is particularly preferred.

<Fine particles>
The polarizing plate protective film of the present invention preferably contains fine particles.

  The fine particles used in the present invention include, as examples of inorganic compounds, silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, tin oxide, indium oxide, zinc oxide, ITO, antimony oxide. Alternatively, these composite oxides, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate can be mentioned. Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable.

  The average primary particle diameter of the fine particles is preferably 5 nm to 1 μm, and more preferably 5 to 50 nm. These are mainly contained as primary particles or secondary aggregates having a particle size of 0.05 to 1 μm, preferably 0.05 to 0.3 μm. The content of these fine particles in the polarizing plate protective film is preferably 0.05 to 10% by mass, and particularly preferably 0.1 to 1% by mass.

  Silicon dioxide fine particles are commercially available, for example, under the trade names Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.). I can do it.

  Zirconium oxide fine particles are commercially available under the trade names of Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used.

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

  Among these, Aerosil 200V and Aerosil R972V are particularly preferably used because they have a large effect of reducing the friction coefficient while keeping the turbidity of the polarizing plate protective film low.

<dye>
A dye may be added to the polarizing plate protective film of the present invention to adjust the color. For example, a blue dye may be added to suppress the yellowness of the film. A preferable dye is an anthraquinone dye.

  The anthraquinone dye may have an arbitrary substituent at an arbitrary position from the 1st position to the 8th position of the anthraquinone. Preferred substituents include an anilino group, hydroxyl group, amino group, nitro group, or hydrogen atom. In particular, it is preferable to contain a blue dye described in paragraphs [0034] to [0037] of JP-A No. 2001-154017, particularly an anthraquinone dye. Further, it preferably contains an infrared absorbing dye, and in particular, any one of thiopyrylium squarylium dye, thiopyrylium croconium dye, pyrylium squarylium dye, and pyrylium croconium dye disclosed in JP-A-2001-154017. It is preferable that Specifically, an infrared absorbing dye represented by the general formula (1) or general formula (2) of the publication can be preferably added.

  Various additives can be used in the present invention.

  For example, it is useful to contain an antioxidant, and the type of antioxidant to be contained is not particularly limited, and various kinds of antioxidants can be used. For example, hindered phenol compounds, phosphite compounds can be used. Examples thereof include antioxidants such as compounds and thioether compounds. Among these, an antioxidant of a hindered phenol compound is preferable in terms of transparency. Content of antioxidant is 0.01-2 mass% normally with respect to polyester, Preferably it is 0.1-0.5 mass%.

  In addition, anti-coloring agents, crystal nucleating agents, slip agents, stabilizers, anti-blocking agents, peeling aids, fluorescent whitening agents, viscosity modifiers, antifoaming agents, clearing agents, antistatic agents, pH adjusting agents, etc. You may let them.

  Various additives may be batch-added to a dope that is a cellulose ester-containing solution before film formation, or an additive solution may be separately prepared and added in-line. In particular, it is preferable to add a part or all of the fine particles in-line in order to reduce the load on the filter medium.

  When the additive solution is added in-line, it is preferable to dissolve a small amount of cellulose ester in order to improve mixing with the dope. A preferable amount of the cellulose ester is 1 to 10 parts by mass, and more preferably 3 to 5 parts by mass with respect to 100 parts by mass of the solvent.

  In order to perform in-line addition and mixing in the present invention, for example, an in-line mixer such as a static mixer (manufactured by Toray Engineering), SWJ (Toray static type in-tube mixer Hi-Mixer) or the like is preferably used.

<Method for producing polarizing plate protective film>
Next, the manufacturing method of the polarizing plate protective film of the present invention will be described by taking cellulose ester as an example of the thermoplastic resin.

  The polarizing plate protective film of the present invention is produced by dissolving a cellulose ester and an additive in a solvent to prepare a dope, casting a dope on a belt-shaped or drum-shaped metal support, and casting the dope. Is performed by a step of drying as a web, a step of peeling from a metal support, a step of stretching or maintaining the width, a step of further drying, and a step of winding up the finished film.

  The process for preparing the dope will be described. The concentration of cellulose ester in the dope is preferably higher because the drying load after casting on the metal support can be reduced. However, if the concentration of cellulose ester is too high, the load during filtration increases and the filtration accuracy increases. Becomes worse. As a density | concentration which makes these compatible, 10-35 mass% is preferable, More preferably, it is 15-25 mass%.

  The solvent used in the dope of the present invention may be used alone or in combination of two or more. However, it is preferable from the viewpoint of production efficiency that a good solvent and a poor solvent of cellulose ester are mixed and used. The more solvent is preferable from the viewpoint of solubility of the cellulose ester. The preferable range of the mixing ratio of the good solvent and the poor solvent is 70 to 98% by mass for the good solvent and 2 to 30% by mass for the poor solvent. With a good solvent and a poor solvent, what dissolve | melts the cellulose ester to be used independently is defined as a good solvent, and what poorly swells or does not melt | dissolve is defined as a poor solvent. Therefore, depending on the acyl group substitution degree of the cellulose ester, the good solvent and the poor solvent change. For example, when acetone is used as the solvent, the cellulose ester acetate ester (acetyl group substitution degree 2.4) and cellulose acetate propionate are good. As a solvent, cellulose acetate (acetyl group substitution degree 2.8) is a poor solvent.

  Although the good solvent used for this invention is not specifically limited, Organic halogen compounds, such as a methylene chloride, dioxolanes, acetone, methyl acetate, methyl acetoacetate, etc. are mentioned. Particularly preferred is methylene chloride or methyl acetate.

  Moreover, although the poor solvent used for this invention is not specifically limited, For example, methanol, ethanol, n-butanol, cyclohexane, cyclohexanone, etc. are used preferably. Moreover, it is preferable that 0.01-2 mass% of water contains in dope.

  A general method can be used as a method of dissolving the cellulose ester when preparing the dope described above. When heating and pressurization are combined, it is possible to heat above the boiling point at normal pressure. It is preferable to stir and dissolve while heating at a temperature that is equal to or higher than the boiling point of the solvent at normal pressure and that the solvent does not boil under pressure, in order to prevent the generation of massive undissolved materials called gels and mamacos. Moreover, after mixing a cellulose ester with a poor solvent and making it wet or swell, the method of adding a good solvent and melt | dissolving is also used preferably.

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

  The heating temperature with the addition of a solvent is preferably higher from the viewpoint of the solubility of the cellulose ester, but if the heating temperature is too high, the required pressure increases and the productivity deteriorates. A preferable heating temperature is 45 to 120 ° C, more preferably 60 to 110 ° C, and still more preferably 70 ° C to 105 ° C. The pressure is adjusted so that the solvent does not boil at the set temperature.

  Alternatively, a cooling dissolution method is also preferably used, whereby the cellulose ester can be dissolved in a solvent such as methyl acetate.

  Next, this cellulose ester solution is filtered using a suitable filter medium such as filter paper. As the filter medium, it is preferable that the absolute filtration accuracy is small in order to remove insoluble matters and the like, but there is a problem that the filter medium is likely to be clogged if the absolute filtration accuracy is too small. For this reason, a filter medium with an absolute filtration accuracy of 0.008 mm or less is preferable, a filter medium with 0.001 to 0.008 mm is more preferable, and a filter medium with 0.003 to 0.006 mm is still more preferable.

  There are no particular restrictions on the material of the filter medium, and ordinary filter media can be used. However, plastic filter media such as polypropylene and Teflon (registered trademark), and metal filter media such as stainless steel do not drop off fibers. preferable. It is preferable to remove and reduce impurities, particularly bright spot foreign matter, contained in the raw material cellulose ester by filtration.

Bright spot foreign matter is when two polarizing plates are placed in a crossed Nicol state, a cellulose ester film is placed between them, light is applied from the side of one polarizing plate, and observed from the side of the other polarizing plate. It is a point (foreign matter) where light from the opposite side appears to leak, and the number of bright spots having a diameter of 0.01 mm or more is preferably 200 / cm ² or less. More preferably, it is 100 pieces / cm < ² > or less, More preferably, it is 50 pieces / m < ² > or less, More preferably, it is 0-10 pieces / cm < ² > or less. Further, it is preferable that the number of bright spots of 0.01 mm or less is small.

  The dope can be filtered by an ordinary method, but the method of filtering while heating at a temperature not lower than the boiling point of the solvent at normal pressure and in a range where the solvent does not boil under pressure is the filtration pressure before and after filtration. The increase in the difference (referred to as differential pressure) is small and preferable. A preferred temperature is 45 to 120 ° C, more preferably 45 to 70 ° C, and still more preferably 45 to 55 ° C.

  A smaller filtration pressure is preferred. The filtration pressure is preferably 1.6 MPa or less, more preferably 1.2 MPa or less, and further preferably 1.0 MPa or less.

  Here, the dope casting will be described.

  The metal support in the casting (casting) step preferably has a mirror-finished surface, and a stainless steel belt or a drum whose surface is plated with a casting is preferably used as the metal support. The cast width can be 1 to 4 m. The surface temperature of the metal support in the casting step is set to −50 ° C. to a temperature at which the solvent boils and does not foam. A higher temperature is preferable because the web can be dried faster, but if it is too high, the web may foam or flatness may deteriorate. The preferable support temperature is appropriately determined at 0 to 100 ° C, and more preferably 5 to 30 ° C. Alternatively, it is also a preferable method that the web is gelled by cooling and peeled from the drum in a state containing a large amount of residual solvent. The method for controlling the temperature of the metal support is not particularly limited, and there are a method of blowing hot air or cold air, and a method of contacting hot water with the back side of the metal support. It is preferable to use warm water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short. When using warm air, considering the temperature drop of the web due to the latent heat of vaporization of the solvent, while using warm air above the boiling point of the solvent, there may be cases where wind at a temperature higher than the target temperature is used while preventing foaming. . In particular, it is preferable to perform drying efficiently by changing the temperature of the support and the temperature of the drying air during the period from casting to peeling.

  In order for the cellulose ester film to exhibit good flatness, the residual solvent amount when peeling the web from the metal support is preferably 10 to 150% by mass, more preferably 20 to 40% by mass or 60 to 130% by mass. Especially preferably, it is 20-30 mass% or 70-120 mass%.

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

Residual solvent amount (% by mass) = {(MN) / N} × 100
M is the mass of a sample collected during or after the production of the web or film, and N is the mass after heating M at 115 ° C. for 1 hour.

  The poor solvent ratio in the residual solvent can be measured by the following measuring method.

(Poor solvent amount in residual solvent amount)
The residual solvent is collected from the sample containing the residual solvent, and each solvent is quantified by gas chromatography measurement.

Poor solvent ratio (%) in residual solvent = {Poor solvent content (g) / Total residual solvent amount (g)} × 100
The residual solvent amount can be measured for each type of solvent by the method described below.

  A film of a certain area is cut out, finely cut to about 5 mm, stored in a dedicated vial, sealed with a septum and an aluminum cap, and then set in a head space sampler HP7694 manufactured by Hewlett-Packard. Gas chromatography (GC) connected to a headspace sampler uses a 5971 model manufactured by Hewlett-Packard Co. equipped with a flame ionization detector (FID) as a detector. The measurement conditions are as follows.

Headspace sampler heating conditions: 120 ° C, 20 minutes GC introduction temperature 150 ° C
Column: DB-624 manufactured by J & W
Temperature rise: 45 ° C, hold for 3 minutes → 100 ° C (8 ° C / min)
A gas chromatogram is obtained using the above measurement conditions. After storing a certain amount of each solvent to be measured diluted with butanol in a vial, each solvent is measured using a calibration curve prepared using the peak area of the chromatogram obtained by measurement in the same manner as described above. The amount of residual solvent in the film was obtained, and the poor solvent ratio in the residual solvent was determined from the above formula.

  Specifically, the ratio of a good solvent such as methylene chloride or methyl acetate and a poor solvent such as an alcohol having 1 to 4 carbon atoms can be obtained and used as the poor solvent ratio in the residual solvent.

Ratio of poor solvent in residual solvent (%) = {content of poor solvent (C1-C4 alcohol (g)) / total residual solvent amount (C1-C4 alcohol + methylene chloride or methyl acetate (g)] )} × 100
Further, in the drying step of the cellulose ester film, the web is peeled off from the metal support, and further dried, and the residual solvent amount is preferably 1% by mass or less, more preferably 0.1% by mass or less, Especially preferably, it is 0-0.01 mass% or less.

  In the film drying process, generally, a roll drying method (a method in which a plurality of rolls arranged on the upper and lower sides are alternately passed through and dried) or a method of drying while transporting the web by a tenter method is adopted.

  In order to produce the cellulose ester film for the polarizing plate protective film of the present invention, after peeling from the metal support, the film may be stretched by 1.05 to 1.2 times in the transport direction or the transport direction and the orthogonal direction. preferable.

  Stretching in the transport direction (also referred to as MD direction) is preferably performed immediately after peeling by a peeling tension and a subsequent transport tension. For example, it is preferable to peel at a peeling tension of 210 N / m or more, and particularly preferably 220 to 300 N / m.

  In order to stretch in the conveyance direction and the orthogonal direction (also referred to as the width direction or the TD direction), it is preferable to use a tenter method in which both ends of the web are gripped with clips or the like. It is particularly preferable to use a tenter capable of independently controlling the distance to the end of gripping) on the left and right. In particular, when producing an optical film that is stretched within a relatively low magnification range as in the present invention, it was difficult to make the retardation size and the direction of the slow axis uniform by stretching. By controlling the stretching, it can be controlled with high accuracy.

  As a means for controlling the length of the portion gripping the left and right ends of the web with the tenter stretching device independently on the left and right sides and making the grip length of the web different on the left and right, specifically, for example, as shown in FIG. There is something like this. FIG. 1 schematically shows an example of a tenter stretching apparatus (10a) that is preferably used in manufacturing a polarizing plate protective film according to the present invention. In the same figure, the grip start position of the left and right grip means (clips) (2a) (2b) of the tenter stretching device (10a) is changed left and right, that is, the installation position of the clip closer (3a) (3b) is changed left and right. By changing the grip start position on the left and right, the left and right grip length of the film (F) is changed, thereby generating a force that twists the resin film (F) in the tenter (10a). The misalignment due to the conveyance can be corrected, and the stretching can be controlled with high accuracy. Further, it is possible to effectively prevent the meandering, slipping and wrinkling of the web.

  Although the illustrated tenter stretching device (10a) is schematically illustrated, it is usually provided in a single row state of a pair of left and right rotational drive devices (ring-shaped chains) (1a) (1b) made of an endless chain. Of the large number of clips (2a) and (2b), the clip (2a) and (2b) of the chain forward straight transition portion that grips and pulls both the left and right ends of the film (F) is the width direction of the film (F) The tracks of the left and right chains (1a) and (1b) are installed so as to be gradually separated from each other, and the film (F) is stretched in the width direction.

  The stretching time is preferably a short time. However, the minimum required stretching time range is defined from the viewpoint of web uniformity. Specifically, the range is preferably 1 to 10 seconds, and more preferably 4 to 10 seconds. Moreover, it is effective that the temperature at the time of extending | stretching is the range of the glass transition point -30--1 degreeC of this film, Preferably it is 100-160 degreeC.

In the tenter process, the heat transfer coefficient may be constant or changed. The heat transfer coefficient preferably has a heat transfer coefficient in the range of 41.9 to 419 × 10 ³ J / m ² hr. More preferably, in the range of ^{41.9~209.5 × 10 3 J / m 2} hr, and most preferably a range of ^{41.9~126 × 10 3 J / m 2} hr.

  The stretching speed in the width direction may be constant or may be changed. The stretching speed is preferably 50 to 500% / min, more preferably 100 to 400% / min, and most preferably 200 to 300% / min.

  In the tenter process, it is preferable that the temperature distribution in the width direction of the atmosphere is small from the viewpoint of improving the uniformity of the web, and the temperature distribution in the transverse direction in the tenter process is preferably within ± 5 ° C, and within ± 2 ° C. More preferably, it is within ± 1 ° C. By reducing the temperature distribution, it can be expected that the temperature distribution in the width direction of the web is also reduced.

  In the present invention, it is preferable to add a device for preventing meandering of a long film in order to correct wrinkles, creases, distortions, etc. more accurately, and an edge position controller (EPC) described in JP-A-6-8663. It is preferable to use a meandering correction device such as a center position controller (also referred to as CPC). These devices detect the edge of the film with an air servo sensor or optical sensor and control the transport direction based on that information so that the center of the edge of the film and the width direction is a constant transport position. Specifically, as the actuator, one or two guide rolls or a flat expander roll with drive is applied to the left and right (or up and down) with respect to the line direction to correct meandering, or to the left and right of the film A small pair of two pinch rolls is installed (one on the front and back of the film, and it is on both sides of the film), and the film is sandwiched and pulled to correct meandering. (Cross guider method). The principle of the meandering correction of these devices is that when the film is moving, for example, when going to the left, in the former method, the roll is tilted so that the film goes to the right, and in the latter method, one set on the right side is used. This pinch roll is nipped and pulled to the right. It is preferable to install at least one of these meandering prevention devices between the film peeling point and the tenter stretching device.

  It is preferable to provide a post-drying step (hereinafter, step D1) after the treatment in the tenter step.

  120-200 N / m is preferable and, as for the web conveyance tension | tensile_strength in process D1, 140-200 N / m is still more preferable. 140 to 160 N / m is most preferable.

  It is preferable to provide a tension cut roll for the purpose of preventing the web from stretching in the transport direction in step D1.

  The means for drying the web is not particularly limited, and can be generally performed with hot air, infrared rays, a heating roll, microwave, or the like, but it is preferably performed with hot air in terms of simplicity.

  The drying temperature in the web drying step is preferably increased stepwise from 30 to 150 ° C, and more preferably from 50 to 140 ° C in order to improve dimensional stability.

  The film thickness of the polarizing plate protective film is required to be in the range of 10 to 45 μm and preferably in the range of 20 to 40 μm for obtaining the effects of the present invention.

  In this invention, if it is the said film thickness range, the polarizing plate protective film made into the multilayer structure by the co-casting method may be sufficient. When the polarizing plate protective film has a multilayer structure, the plasticizer, ultraviolet absorber, and other additives can be appropriately blended in the base layer, the surface layer, or both.

  The variation of the thickness of the polarizing plate protective film is preferably within ± 3% in both the width direction and the longitudinal direction, more preferably within ± 2%, and particularly preferably within ± 0.5%.

  The polarizing plate protective film of the present invention preferably has a width of 1 to 4 m. Preferably it is 1.4-4m, More preferably, it is the range of 1.5-3m.

<Physical properties>
Moisture permeability of the polarizing plate protective film of the present invention, 40 ° C., or less 850g / m ² · 24h at 90% RH, preferably ^{20~800g / m 2 · 24h, 20~750g} / m 2 · 24h It is particularly preferred that The moisture permeability can be measured according to the method described in JIS Z 0208.

  The breaking elongation of the polarizing plate protective film of the present invention as measured by the following measurement is preferably 10 to 80%, more preferably 20 to 50%.

(Measurement of elongation at break)
A film containing an arbitrary residual solvent is cut into a sample width of 10 mm and a length of 130 mm, and a sample stored for 24 hours at 23 ° C. and 55% RH is obtained by performing a tensile test at a pulling speed of 100 mm / min with a distance between chucks of 100 mm. be able to.

  The haze by the following measurement of the cellulose ester film used in the present invention is preferably less than 10%, more preferably less than 1%, and particularly preferably 0 to 0.1%. The visible light transmittance is preferably 90% or more, more preferably 92% or more, and further preferably 94% or more.

(Haze value)
According to JIS K-6714, it can be measured using a haze meter (1001DP type, manufactured by Nippon Denshoku Industries Co., Ltd.) and used as an index of transparency.

(Measurement of transmittance)
Transmittance T is 380, 400, 500 nm from spectral transmittance τ (λ) obtained every 10 nm in a wavelength region of 350-700 nm using a spectral altimeter U-3400 (Hitachi, Ltd.). Transmittance can be calculated.

  The in-plane retardation value Ro of the cellulose ester film used in the present invention is 5 to 20 nm or less, and the retardation value Rth in the film thickness direction is 70 to 120 nm or less. The retardation value Ro is 5 to 15 nm or less, and the retardation value Rth is 100 to 110 nm or less.

  The retardation values Ro and Rth can be obtained by the following equations.

Ro = (nx−ny) × d
Rth = ((nx + ny) / 2−nz) × d
Here, nx is the maximum refractive index in the plane, ny is the refractive index in the direction perpendicular to nx in the plane, nz is the refractive index in the film thickness direction, each refractive index is a value of 590 nm, and d is a film film. Represents thickness (nm).

  The retardation values Ro and Rth can be measured using an automatic birefringence meter. For example, the wavelength can be obtained at 590 nm in an environment of 23 ° C. and 55% RH using KOBRA-21ADH (Oji Scientific Instruments).

  Moreover, the in-plane maximum refractive index of the polarizing plate protective film of the present invention is substantially parallel or substantially orthogonal to the film transport direction, both of which are the film transport direction ± 1 ° or the direction perpendicular to the film transport direction ± Preferably it is at 1 °.

  The polarizing plate protective film of the present invention is preferably used for a liquid crystal display member from the viewpoint of excellent moisture permeability, dimensional stability, etc., and in particular, polarizing plate protection for expanding the viewing angle bonded to the polarizing plate. Used as a film. In particular, use as a polarizing plate protective film that also serves as an optical compensation film is useful for reducing the number of polarizing plate members and reducing the thickness.

  For example, the polarizing plate protective film is subjected to a surface saponification treatment with a 2.5 mol / L sodium hydroxide aqueous solution at 40 ° C. for 60 seconds, washed with water for 3 minutes and dried. Separately, a 120 μm-thick polyvinyl alcohol was immersed in 100 parts by mass of an aqueous solution containing 1 part by mass of iodine and 4 parts by mass of boric acid, and a polarizing film stretched in the vertical direction at 50 ° C. was prepared. A polarizing plate can be produced by directly bonding a polarizing plate protective film subjected to the above surface saponification treatment on at least one surface using a 5% by mass aqueous solution of a completely saponified polyvinyl alcohol as an adhesive.

  Moreover, the polarizing plate protective film of the present invention can be used on both sides of the polarizing film or only on one side. When used on one side, the polarizing plate protective film on the opposite side of the polarizing film may be coated with a hard coat or the like, or the dichroic dye or the like is applied to the polarizing plate protective film of the present invention in the same direction. A polarizing plate can also be produced.

  The polarizing plate protective film of the present invention preferably has a light transmittance (of visible light) of 90% or more after saponification treatment, more preferably 94% or more, and further preferably 95% or more. The haze is preferably less than 1.4%, more preferably less than 1.0%, and further preferably less than 0.5%. In particular, 0% is most preferable.

  As another polarizing plate protective film to be bonded to the other surface, a commercially available cellulose ester film such as Konica Minoltack KC8UX, KC4UX, KC5UX, KC8UCR3, KC8UCR4, KC8UY, KC4UY, KC12UR, KC8UCR-3, KC8UCR- 4, KC8UCR-5, KC8UY-HA, KC8UX-RHA, KC8UX-RHA-N, Konica Minolta Opto, Fujitac TD80UF, T80UZ, T40UZ, anti-reflection film (Fuji Film CV Clear View UA) Fuji Photo Film A product made by Co., Ltd. is preferably used. The polarizing plate protective film used on the other surface of the polarizing plate protective film of the present invention is an optically isotropic polarizing plate having an in-plane retardation Ro of 0 to 20 nm and an Rth of -50 to 50 nm. A protective film is preferred. The polarizing plate protective film preferably has a hard coat layer or an antiglare layer having a thickness of 8 to 20 μm. For example, JP-A Nos. 2003-114333, 2004-203209, and 2004-354699 are disclosed. , 2004-354828, etc., a polarizing plate protective film having a hard coat layer or an antiglare layer is preferably used. Further, an antireflection layer, an antifouling layer or the like is preferably laminated on the hard coat layer or antiglare layer.

  Alternatively, a polarizing plate protective film that also serves as an optical compensation film having an optically anisotropic layer formed by aligning liquid crystal compounds such as discotic liquid crystal, rod-shaped liquid crystal, and cholesteric liquid crystal can be used. For example, the optically anisotropic layer can be formed by the method described in JP-A-2003-98348.

  The polarizing plate thus obtained is provided on one side or both sides of the cell side of the liquid crystal cell. In any case, the polarizing plate protective film of the present invention is disposed closer to the liquid crystal cell than the polarizing film, whereby the liquid crystal display device of the present invention is obtained.

  The polarizing plate protective film of the present invention can be applied to liquid crystal cells of various display modes. For example, TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), OCB (Optically Compensatory Bend). STN (Super Twisted Nematic), VA (Vertically Aligned), ECB (Electrically Controlled Birefringence), and HAN (Hybrid Aligned Nematic) liquid crystal cells that can be used.

  The polarizing plate protective film of the present invention or the polarizing plate using the same is particularly preferably incorporated in a TN mode liquid crystal display device.

  TN mode liquid crystal cells are used in the most widespread color TFT liquid crystal displays, and are described in various documents.

  Hereinafter, the liquid crystal display device of the present invention will be described with reference to the drawings.

  Units such as electrodes, color filters, and backlights are not shown because the drawing becomes complicated and optically important parts of the present invention are difficult to see.

  FIG. 2 is a schematic view showing an example of an optical rotation mode liquid crystal display device.

  FIG. 2A is a schematic diagram showing the liquid crystal monitor A. A portion (diamond) of the liquid crystal portion is taken out, the polarizing plate 11 of the partial configuration is shown in FIG. 2B, and the liquid crystal cell 12 is shown in FIG. FIG. 2D shows the other polarizing plate 13 in c).

  2B and 2D, reference numerals 14 and 22 denote polarizing plate protective films, reference numerals 15 and 21 denote polarizing films, and adjacent polarizing plate protective films 16 and 20 having the optical compensation function of the present invention. is there.

  2B and 2D, the arrow 23 is the absorption axis of the polarizing film, and 24 is the in-plane slow axis of the polarizing plate protective film having an optical compensation function.

  In FIG. 2C, 17 and 19 are substrates, 25 and 26 are rubbing axes, and 18 is a liquid crystal.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

<< Production of polarizing plate protective film >>
The cellulose ester, plasticizer, and ultraviolet absorber used are listed in Table 1.

<Fine particle dispersion>
Fine particles (Aerosil R972V (produced by Nippon Aerosil Co., Ltd.)) 11 parts by mass (average diameter of primary particles 16 nm, apparent specific gravity 90 g / liter)
89 parts by mass of ethanol or more was stirred and mixed with a dissolver for 50 minutes, and then dispersed with Manton Gorin.

<Fine particle additive solution>
Cellulose ester C-3 was added to a dissolution tank containing methylene chloride and heated to completely dissolve, and this was then added to Azumi Filter Paper No. Filtered using 244. While finely stirring the filtered cellulose ester solution, the fine particle dispersion was slowly added thereto. Further, the particles were dispersed by an attritor so that the secondary particles had a predetermined particle size. This was filtered through Finemet NF manufactured by Nippon Seisen Co., Ltd. to prepare a fine particle additive solution.

Methylene chloride 99 parts by weight Cellulose ester C-3 (cellulose acetate propionate; acetyl group substitution degree 1.7, propionyl group substitution degree 0.7, total acyl group substitution degree 2.4) 4 parts by weight Fine particle dispersion 11 parts by weight <Composition of main dope 101>
Methylene chloride 300 parts by mass Ethanol 40 parts by mass Cellulose ester C-3 (cellulose acetate propionate; acetyl group substitution degree 1.7, propionyl group substitution degree 0.7, total acyl group substitution degree 2.4) 100 parts by mass Plasticity Agent (A) 6.5 parts by weight Plasticizer Ethylphthalylethyl glycolate 5.5 parts by weight UV absorber (A) 1.2 parts by weight UV absorber (B) 0.8 part by weight Dope solution 101 having the above composition Was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. The cellulose ester was added to the pressure dissolution tank containing the solvent while stirring. This was heated and stirred to completely dissolve, and a plasticizer and an ultraviolet absorber were further added and dissolved. This was designated as Azumi Filter Paper No. The main dope solution 101 was prepared by filtration using 244.

  Add 100 parts by weight of the main dope solution 101 and 5 parts by weight of the fine particle additive solution, mix thoroughly with an in-line mixer (Toray static in-tube mixer Hi-Mixer, SWJ), and then use a belt casting apparatus. And uniformly cast on a stainless steel band support having a width of 2 m. On the stainless steel band support, peeling is performed under the conditions of a peeling tension of 130 N / m, a residual solvent amount of 100% by mass, and a cold air temperature of 20 ° C. Further, a portion (roll) for cutting the tension of the peeling portion and the next transport tension are set. The conveyance was performed with a speed difference from the portion to be applied (roll).

  Next, the both ends of the web are gripped by clips with a tenter device capable of independently controlling the gripping length of the web (distance from the start of gripping to the end of gripping) by the left and right gripping means of FIG. 1, and 1.05 times at 145 ° C. And then holding the width at 145 ° C. and then releasing the holding, and further carrying it in a drying zone set at 145 ° C. for 30 minutes for drying, a width of 1.4 m and a width of 1 cm at the end. A polarizing plate protective film 101 having a film thickness of 40 μm having a knurling height of 8 μm was produced.

  Next, as shown in Table 2, the types of cellulose ester, plasticizer, and UV absorber, stretch ratio, and film thickness were changed to prepare polarizing plate protective films 102 to 124.

  Furthermore, a polarizing plate protective film 125 in which an optically anisotropic layer was formed on a TAC film having a thickness of 120 μm using a liquid crystal compound by the method described in Example 1 of JP2001-100042 A was prepared.

  The retardation values Ro and Rth of the produced polarizing plate protective film were measured by the following method and listed in Table 2.

[Measurement of retardation values Ro and Rth]
The average refractive index of the film sample was measured using an Abbe refractometer (1T) and a spectral light source. Moreover, the thickness of the film was measured using a commercially available micrometer.

  Using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments Co., Ltd.), in a film that was allowed to stand for 24 hours in an environment of 23 ° C. and 55% RH, the retardation of the film was measured at a wavelength of 589 nm in the same environment. went. The above-described average refractive index and film thickness are input to the following formula, and the in-plane retardation value Ro and the thickness direction retardation value Rth are obtained. The direction of the slow axis with respect to the width direction of the film is also measured at the same time.

Ro = (nx−ny) × d
Rth = {(nx + ny) / 2−nz} × d
(Where nx is the refractive index in the slow axis direction in the film plane, ny is the refractive index in the fast axis direction in the film plane, nz is the refractive index in the thickness direction of the film, and d is (The thickness of the film (nm).)

<Production of polarizing plate>
Subsequently, a polarizing plate was produced using each polarizing plate protective film 101-125.

  A polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times). This was immersed in an aqueous solution composed of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 ° C. composed of 6 g of potassium iodide, 7.5 g of boric acid and 100 g of water. This was washed with water and dried to obtain a polarizing film.

  Next, according to the following steps 1 to 5, a polarizing plate is prepared by laminating Konica Minolta Tack KC8UX-RHA (manufactured by Konica Minolta Opto) as the polarizing film, the retardation films 101 to 125, and the cellulose ester film on the back surface side. did.

  Step 1: Soaked in a 1 mol / L sodium hydroxide solution at 50 ° C. for 60 seconds, then washed with water and dried to obtain a saponified cellulose ester film bonded to the polarizing film.

  Step 2: The polarizing film was immersed in a polyvinyl alcohol adhesive tank having a solid content of 2% by mass for 1 to 2 seconds.

  Step 3: Lightly wipe off excess adhesive adhering to the polarizing film in Step 2 and place it on the cellulose ester film treated in Step 1, so that the anti-reflection layer of KC8UX-RHA is on the outside Laminated and placed.

Step 4: The polarizing plate protective film, the polarizing film, and the cellulose ester film sample laminated in Step 3 were bonded at a pressure of 20 to 30 N / cm ² and a conveyance speed of about 2 m / min.

  Step 5: A polarizing plate prepared in Step 4 in a drier at 80 ° C., a sample obtained by bonding the cellulose ester film and the polarizing plate protective films 101 to 125 were dried for 2 minutes to prepare polarizing plates 101 to 125.

<Production of liquid crystal cell and liquid crystal display device>
A polyimide alignment film was provided on a glass substrate on which an ITO transparent electrode was provided, and a rubbing treatment was performed. The two substrates were stacked with the alignment film facing each other through a 4.3 μm spacer. The two substrates were arranged so that the rubbing directions of the alignment film were orthogonal. A rod-like liquid crystal molecule (ZLI-4792, manufactured by Merck & Co., Inc.) is injected into the gap between the substrates, and the polarizing plate protective film according to the present invention of the polarizing plates 101 to 125 is provided on both sides of the TN liquid crystal cell produced as described above. Two sheets were attached using an adhesive so as to be on the cell side, and a liquid crystal display device was produced. A rectangular wave voltage of 55 Hz is applied to the liquid crystal cell of the liquid crystal display device, and the contrast ratio is 10 in the upper, lower, left, and right directions, with the transmittance of white display and black display at 1.6 V for white display and 4.8 V for black display as the contrast ratio. The viewing angle at which 20 was obtained was measured. In addition, the polarizing plate was bonded to the liquid crystal cell so that the rubbing axis of the substrate on which the polarizing plate was bonded coincided with the absorption axis of the polarizing plate.

<Evaluation>
The viewing angle measurement was performed using EZ-contrast 160R manufactured by ELDIM.

  For the measurement of the change in hue 60 °, the color luminance meter BM-5A manufactured by Topcon Co., Ltd. and a self-made turntable were used, and the polarizing plate protective film and elliptical polarizing plate of the present invention were bonded to a commercially available panel. With a white display, a self-made liquid crystal cell used a three-color light source (Hakuba Light Viewer 7000PRO), and a change in hue of 60 ° was measured based on the color of the light source.

(Viewing angle)
TN viewing angle evaluation criteria:
◎: Improved by 30 ° or more each on the left and right compared with the following commercially available TN ○: Improved 15 ° or more on each of the left and right compared with the following commercially available TN No improvement compared with the following commercially available TN Viewing angle of a commercially available TN type liquid crystal display device:
Viewing angle Up / Down Left / Right Inverted Left / Right TN 27 ° 60 ° 45 ° × 2 40 °
(Color change)
The produced liquid crystal display device was displayed in white, and a change in hue of 60 ° was measured by the following method.

  The measurement of the change in color 60 ° was measured using a Topcon Co., Ltd. color luminance meter BM-5A and a self-made turntable, and the polarizing plate protective film and polarizing plate of the present invention were bonded to a commercially available panel. In the display, in a self-made liquid crystal cell, a three-color light source (Hakuba Light Viewer 7000PRO) was used, and a change in hue of 60 ° was measured based on the color of the light source.

  As the maximum color change, when the absolute value of the amount of change in each coordinate axis of the xy coordinates was Δx and Δy, respectively, the evaluation was performed according to the following criteria.

○: Δx <0.02 and Δy <0.01
Δ: satisfies 0.02 ≦ Δx <0.2 and 0 ≦ Δy <0.2,
Or 0 ≦ Δx <0.2 and 0.01 ≦ Δy <0.2
X: Δx ≧ 0.2 or Δy ≧ 0.2
(Frame unevenness)
Each manufactured liquid crystal display device was lit for 1000 hours, and then the presence or absence of light leakage (frame unevenness) around the screen in black display was visually confirmed.

◯: No light leakage in the vicinity is observed. Δ: Light leakage in the periphery is recognized. X: Light leakage in the periphery is remarkable.

  From Table 2, it is clear that the polarizing plate using the polarizing plate protective film having the configuration of the present invention has improved viewing angle, color change, and frame unevenness as compared with the comparative example.

  It has also been found that the effect of the present invention is further improved by using a tenter device that can independently control the web gripping length (distance from the start of gripping to the end of gripping) by the left and right gripping means.

An example of the tenter stretching apparatus (10a) preferably used in the present invention is schematically shown. It is the schematic which shows an example of the liquid crystal display device of TN mode of this invention.

Explanation of symbols

1a Left ring chain (rotary drive)
1b Right wheel chain (rotary drive)
2a left clip 2b right clip 3a left clip closer 3b right clip closer 4a left clip opener 4b right clip opener 10a tenter stretching device 11, 13 polarizing plate 12 liquid crystal cell 14, 22 polarizing plate protective film 15, 21 polarizing film 16, 20 optical Polarizing plate protective film having compensation function 23 Absorption axis of polarizing film 24 In-plane slow axis of polarizing plate protective film having optical compensation function 17, 19 Substrate 18 Liquid crystal 25, 26 Rubbing axis

Claims (8)

A polarizing plate protective film having an optical compensation function containing a thermoplastic resin, wherein the polarizing plate protective film has a thickness in a range of 10 to 45 μm, and Ro represented by the following formula is in a range of 5 to 20 nm. And Rth is in the range of 70 to 120 nm.
(I) Ro = (nx−ny) × d
(Ii) Rth = ((nx + ny) / 2−nz) × d
Where nx is the maximum refractive index in the plane, ny is the refractive index in the direction perpendicular to nx in the plane, nz is the refractive index in the film thickness direction, each refractive index is a value of 590 nm, and d is the film thickness of the film. (Nm). The polarizing plate protective film according to claim 1, wherein the polarizing plate protective film contains a cellulose ester. The polarizing plate protective film according to claim 2, wherein the cellulose ester has an acetyl group substitution degree of X and a propionyl group substitution degree of Y, which satisfies the following formula.
(Iii) 2.0 ≦ (X + Y) ≦ 2.6
(Iv) 0.1 ≦ Y ≦ 1.0 The polarizing plate protective film is a film that stretches 1.05 to 1.2 times in the transport direction or in the direction perpendicular to the transport direction, and the in-plane slow axis is substantially parallel to or substantially perpendicular to the transport direction. The polarizing plate protective film of any one of Claims 1-3 characterized by the above-mentioned. The stretching according to claim 4 is performed using a tenter capable of independently controlling the gripping length of the web (distance from the start of gripping to the end of gripping) left and right by the right and left gripping means. Method. A polarizing plate comprising the polarizing plate protective film according to claim 1 on at least one surface. A liquid crystal display device using the polarizing plate according to claim 6, wherein the polarizing plate protective film is bonded to the liquid crystal cell side. 8. The liquid crystal display device according to claim 7, wherein the liquid crystal cell is a Twisted Nematic (hereinafter also referred to as TN) type liquid crystal cell.

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