KR20140042714A - Cellulose acylate film, polarizing plate, and liquid crystal display device - Google Patents

Abstract

The present invention relates to a cellulose acylate film having a thin thickness. When the cellulose acylate film is inserted in a liquid crystal display device, non-uniform display rarely occurs, and a high front contrast can be realized. The cellulose acylate film contains cellulose acylate having a total acyl group substitution degree of 2.1-2.6 and satisfies the following (1) to (4): (1) at least one kind of poly-condensed ester that contains aromatic dicarboxylic acid residues and aliphatic diol residues, wherein the ratio of the aromatic dicarboxylic acid residues to the entire dicarboxylic acid residues in the poly-condensed ester is 70 mol% or more; (2) the thickness of the film is 15-45 μm; (3) the retardation (Rth) in a thickness direction for a wavelength of 550 nm satisfies Rth/d>=0.0025, wherein d represents the thickness (nm) of the film; and (4) the absolute value of an Rth change during a water contact test is 5 nm.

Description

Cellulose acylate film, polarizer and liquid crystal display device {CELLULOSE ACYLATE FILM, POLARIZING PLATE, AND LIQUID CRYSTAL DISPLAY DEVICE}

The present invention relates to a cellulose acylate film, and a polarizing plate and a liquid crystal display device using the cellulose acylate film. In particular, it is related with the cellulose acylate film which can be used suitably as optical films, such as a polarizing plate protective film and retardation film.

Background Art In recent years, TV applications of liquid crystal display devices have progressed, and high quality and low price associated with the increase in screen size have been increasingly demanded. In particular, the liquid crystal display device of VA mode has become the most common as a liquid crystal display device for TV from the point of comparatively high contrast and comparatively high manufacture yield. Although a polarizing plate is inserted in such a liquid crystal display device, the cellulose acylate film is employ | adopted as a protective film of such a polarizing plate (Unexamined-Japanese-Patent No. 2011-162769 and Unexamined-Japanese-Patent No. 2012-108349).

On the other hand, in recent years, the demand for thinning of a liquid crystal display device is increasing. Therefore, it is advantageous to make the polarizing plate, which is a component of the liquid crystal display, thinner.

As a method of thinning a polarizing plate, it is conceivable to thin the film (cellulose acylate film) which has a cellulose acylate used as a protective film of a polarizing plate as a main component. Here, in order to express predetermined | prescribed retardation (Rth), making the film thickness of a cellulose acylate film thin, it is considered to use the thing with relatively small substitution degree (total acyl substitution degree) of the acyl group of a cellulose acylate. However, the film using the cellulose acylate which has a small degree of the total acyl substitution is concerned that dew condensation nonuniformity arises. Condensation nonuniformity is the nonuniformity which arises by the water partly adhered to the surface of a polarizing plate during the transportation to a cell or a module form, and the part to which water adhered and the part which is not adhered. When the cellulose acylate film having such condensation nonuniformity is inserted into the liquid crystal display device, it is feared to cause display nonuniformity.

Moreover, as a liquid crystal display device, when this cellulose acylate film was inserted into the thin liquid crystal display device whose glass of a panel is 500 micrometers or less, and it carried out the durability test under high temperature, high humidity, the cell using thin film glass bends and a liquid crystal display device is carried out. It can be seen that the nonuniformity of the display occurs.

Among the display unevenness, the unevenness (four corner unevenness) of the corner of the liquid crystal display device caused by the unevenness (water contact portion unevenness) of the contacted water and the warpage of the cell is serious, and also affects the front contrast of the liquid crystal display device.

Moreover, when only one film thickness is made thin among the protective films of a polarizing plate, a polarizing plate will curl and there exists a possibility of generating a bonding defect at the time of bonding to a cell.

Moreover, the usage form of a liquid crystal display device also becomes various, and durability in various environments, such as the environment of low temperature and high humidity, as well as the environment of high temperature and high humidity, is calculated | required. Since much of what has been studied conventionally was improvement of the durability of the polarizing plate in high temperature, high humidity environment, it turned out by examination of this inventor that the durability in another environment may be impaired. Specifically, when the polarizer is used for a long time at a relatively low temperature of about 20 ° C. and under a high humidity environment, red discoloration may occur, but low moisture permeability is observed on both surfaces of the polarizer such as JP 2010-78967 A. It turned out that this discoloration becomes more remarkable when the polarizing plate which has a polymer film of is used.

An object of the present invention is to solve such a problem, and is a polarizing plate having a thin cellulose acylate film, which can be bonded to a cell with good yield, and display irregularities are less likely to occur when inserted into a liquid crystal display device. It is an object to provide a polarizing plate capable of achieving high front contrast.

As a result of earnestly examining by this inventor under such a situation, it discovered that the said subject can be solved by the following means <1>, Preferably by <2>-<12>.

Cellulose acylate film containing the cellulose acylate of <1> all acyl-group substitution degree 2.1-2.6, and satisfy | filling following (1)-(4);

(1) containing at least one polycondensation ester containing an aromatic dicarboxylic acid residue and an aliphatic diol residue, and the ratio of the aromatic dicarboxylic acid residue to all the dicarboxylic acid residues in the polycondensation ester is 70 It is mol% or more;

(2) the film thickness is 15 to 45 µm;

(3) the retardation (Rth) in the film thickness direction at a wavelength of 550 nm satisfies Rth / d ≧ 0.0025 (where d represents the film thickness (nm));

(4) the absolute value of the Rth change at the time of water contact test is 5 nm or less;

Here, the absolute value of the Rth change at the time of the water contact test is taken out after immersing the film in water heated to 40 ° C for 12 hours, and the water droplets on the surface of the film are wiped off and dried naturally, and then in a 25 ° C 60% relative humidity environment. This is the absolute value of the difference between Rth at a wavelength of 590 nm and an untreated state after standing for 24 hours.

The cellulose acylate film as described in <1> whose internal haze of the <2> said cellulose acylate film is 0.05% or less.

The cellulose acylate film as described in <1> or <2> whose <3> said cellulose acylate is cellulose acetate.

<4> A cellulose acylate film is extended | stretched by extending | stretching temperature in Tg-70 degreeC-Tg-30 degreeC (Tg is glass transition temperature of a cellulose acylate) in the state of 35-65 mass% of residual solvents, < The cellulose acylate film in any one of 1>-<3>.

A <5> 1st polarizing plate protective film and a 2nd polarizing plate protective film are included, The said 1st polarizing plate protective film is a cellulose acylate film in any one of <1>-<4>.

The film thickness of a <6> said 2nd polarizing plate protective film is 10-29 micrometers, The polarizing plate as described in <5> characterized by the above-mentioned.

The water vapor transmission rate of the <7> said 2nd polarizing plate protective film is 100 g / m <2> * 24hr or less, The polarizing plate as described in <5> or <6> characterized by the above-mentioned.

<8> The liquid crystal display device which has a polarizing plate in any one of <5>-<7>.

The liquid crystal display device as described in <8> arrange | positioned so that a <9> said 1st polarizing plate protective film may become a liquid crystal cell side.

The liquid crystal display device as described in <8> which is arrange | positioned so that a <10> said 1st polarizing plate protective film may become a liquid crystal cell side, and has glass of 50-500 micrometers in thickness.

Extending | stretching a <11> cellulose acylate film by Tg-70 degreeC-Tg-30 degreeC (Tg is glass transition temperature of a cellulose acylate) in the state of 35-65 mass% of residual solvents, The said cellulose acylate film contains the cellulose acylate of all acyl-group substitution degree 2.1-2.6, and satisfy | fills following (1) and (2), The manufacturing method of the cellulose acylate film characterized by the above-mentioned;

(1) containing at least one polycondensation ester containing an aromatic dicarboxylic acid residue and an aliphatic diol residue, and the ratio of the aromatic dicarboxylic acid residues to all the dicarboxylic acid residues in the polycondensation ester is 70 It is mol% or more;

(2) The film thickness is 15-45 micrometers.

The manufacturing method of the cellulose acylate film as described in <11> whose <12> said cellulose acylate film is a cellulose acylate film in any one of <1>-<4>.

As a thin cellulose acylate film, when it inserts into a liquid crystal display device, a display nonuniformity does not produce easily and the cellulose acylate film which can achieve high front contrast became able to be provided.

Moreover, as a polarizing plate which has a thin cellulose acylate film, the curl of a polarizing plate is small, the display nonuniformity does not arise easily when inserted in a liquid crystal display device, and the polarizing plate which can achieve high front contrast became possible.

1 is a schematic cross-sectional view of an example of a liquid crystal display of the present invention.

Hereinafter, the contents of the present invention will be described in detail. Although description of the element | module described below may be made | formed based on typical embodiment of this invention, this invention is not limited to such embodiment. In addition, it is used by the meaning which includes with "-" the numerical value described before and after that as a lower limit and an upper limit in this specification. In addition, in this specification, "front surface" means the normal line direction with respect to a display surface, and "front contrast" shall mean the contrast computed from the white luminance and black luminance measured in the normal direction of a display surface.

<Cellulose acylate film>

The cellulose acylate film of this invention contains the cellulose acylate of all acyl-group substitution degree 2.1-2.6, and satisfy | fills following (1)-(4); (1) Aromatic dicarboxylic acid residue And at least one polycondensation ester containing an aliphatic diol residue, wherein the ratio of the aromatic dicarboxylic acid residues to all the dicarboxylic acid residues in the polycondensation esters is at least 70 mol%;

(2) the film thickness is 15 to 45 µm;

(3) the retardation (Rth) in the film thickness direction at a wavelength of 550 nm satisfies Rth / d ≧ 0.0025 (where d represents the film thickness (nm));

(4) the absolute value of the Rth change at the time of water contact test is 5 nm or less;

Here, the absolute value of the Rth change at the time of the water contact test is taken out after immersing the film in water heated to 40 ° C for 12 hours, and the water droplets on the surface of the film are wiped off and dried naturally, and then in a 25 ° C 60% relative humidity environment. This is the absolute value of the difference between Rth at a wavelength of 590 nm and an untreated state after standing for 24 hours.

Hereinafter, these details are demonstrated.

<Cellulose acylate>

The cellulose acylate film used by this invention contains the cellulose acylate of all acyl substitution degree 2.1-2.6.

Examples of the film material contained in the cellulose acylate film of the present invention include cellulose esters, and having an ester-substituted cellulose skeleton obtained by introducing a functional group biologically or chemically using the cellulose acylate and other cellulose as a raw material. The compound can be mentioned. Moreover, it is preferable that the cellulose acylate film of this invention contains the said cellulose acylate as a main component. Here, "as a main component" shows the polymer when it consists of a single polymer, and shows the polymer with the highest mass fraction among the polymers which comprise when it consists of several polymer.

The cellulose acylate is an ester of cellulose and carboxylic acid, and as the carboxylic acid, a fatty acid having 2 to 22 carbon atoms is more preferable, and a cellulose acylate which is a lower fatty acid having 2 to 4 carbon atoms is most preferable. Do.

(Cellulose acylate raw material)

Examples of the cellulose of the cellulose acylate raw material used in the present invention include cotton linter and wood pulp (softwood pulp, softwood pulp), and the like. Any cellulose acylate obtained from any raw material cellulose may be used, or may be mixed and used in some cases. . For a detailed description of these raw celluloses, see, for example, "Plastic Material Lecture 17 Fiber-Based Resin" (Marusawa, Uta Books, Daily Industrial Newspaper, 1970). Cellulose described in page 8) can be used, and the cellulose acylate film of the present invention is not particularly limited.

(Substitution degree of cellulose acylate)

Next, the preferable cellulose acylate is described in the present invention, in which the cellulose described above is produced as a raw material.

The cellulose acylate used in the present invention is one in which the hydroxyl group of the cellulose is acylated, and the substituents can be used from the acetyl group having 2 carbon atoms of the acyl group to 22 carbon atoms. Although it does not specifically limit about the measurement of the substitution degree with respect to the hydroxyl group of a cellulose in a cellulose acylate in this invention, The binding degree of the acetic acid substituted by the hydroxyl group of cellulose and / or a C3-C22 fatty acid is measured, The degree of substitution can be obtained by calculation. As a measuring method, it can carry out according to ASTMD-817-91.

As for the cellulose acylate used for this invention, it is preferable that the total acyl substitution degree of the said cellulose acylate is 2.1-2.6, and the said total acyl substitution degree is 2.3-2.6.

Since the total acyl substitution degree of the cellulose acylate used for this invention is more preferable in the viewpoint of the optical characteristic and the humidity stability of an optical characteristic as it is the said preferable range, it is preferable in it being 2.6 or less from a viewpoint which can lower haze more.

Among the acetic acid and / or C3-C22 fatty acid substituted by the hydroxyl group of cellulose, as a C2-C22 acyl group, it may be an aliphatic group, an aryl group, it does not specifically limit, Single or two or more types may be sufficient as it. They are alkylcarbonyl ester, alkenylcarbonyl ester, aromatic carbonyl ester, aromatic alkylcarbonyl ester, etc. of cellulose, for example, and may have group substituted further, respectively. As these preferable acyl groups, an acetyl group, propionyl group, butanoyl group, heptanoyl group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, tridecanoyl group, tetradecanoyl group, hexadecanoyl group, octa Decanoyl group, i-butanoyl group, t-butanoyl group, cyclohexanecarbonyl group, oleoyl group, benzoyl group, naphthylcarbonyl group, cinnamoyl group and the like. Of these, acetyl, propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, oleoyl, benzoyl, naphthylcarbonyl and cinnamoyl groups are preferred, An o-yl group, and a butanoyl group are more preferable. More preferable groups are acetyl group and propionyl group, and most preferred group is acetyl group (when cellulose acylate is cellulose acetate).

It is preferable that the polymerization degree of the cellulose acylate used preferably by this invention is 180-700 in a viscosity average polymerization degree, 180-550 is more preferable, 180-400 are still more preferable, 180-350 in cellulose acetate This is particularly preferred. If the degree of polymerization is less than or equal to the upper limit, the viscosity of the dope solution of cellulose acylate does not become too high, and thus film production by casting can be facilitated. If the degree of polymerization is lower than the lower limit, it is preferable because no problem such as lowering of the strength of the produced film occurs. Viscosity average degree of polymerization can be measured by the intrinsic viscosity method such as Uda Kazuo, Hideo Hideo, "The Textile Society", Vol. 18 No. 1, 105-120 pages (1962). This method is described in detail in Japanese Patent Application Laid-Open No. 9-95538.

Moreover, the molecular weight distribution of the cellulose acylate used preferably by this invention is evaluated by gel permeation chromatography, the polydispersity index Mw / Mn (Mw is mass mean molecular weight, Mn is number average molecular weight) is small, It is preferable that the molecular weight distribution is narrow. As a specific value of Mw / Mn, it is preferable that it is 1.0-4.0, It is more preferable that it is 2.0-4.0, It is most preferable that it is 2.3-3.4.

<Polycondensation ester>

In the present invention, at least one polycondensation ester containing an aromatic dicarboxylic acid residue and an aliphatic diol residue is contained, and the ratio of the aromatic dicarboxylic acid residues to all the dicarboxylic acid residues in the polycondensation ester is 70 It is mol% or more. When such a polycondensation ester is blended, the expression of retardation is increased, and the membrane can be hydrophobized more effectively. Moreover, in the polycondensation ester which has many aromatic units, the interaction between an aromatic ring and a cellulose acylate arises, and even if it contains the water, the orientation of a polycondensation ester hardly changes, and it is a rita before and after water treatment. It is thought that there is an effect of reducing the change of the date.

In the polycondensation ester used in the present invention, both ends thereof are each independently a -OH group, -OC (= O) -R ¹ Group, -C (= O) -OR ² Flag, -OR ³ Group consisting of a group and a -COOH group (wherein the above R ¹ ~ R ³ Each independently represent an aliphatic group).

In this specification, the residue of a polycondensation ester is a partial structure of a polycondensation ester, and shows the partial structure which has the characteristic of the monomer which forms a polycondensation ester. For example, the dicarboxylic acid residue formed from dicarboxylic acid HOOC-R-COOH is -OC-R-CO- and the diol residue formed from diol HO-R'-OH is -O-R'-O - to be.

In the polycondensation ester, an aromatic dicarboxylic acid residue is used as the dicarboxylic acid residue.

Moreover, the ratio of the aromatic dicarboxylic acid residue with respect to all the dicarboxylic acid residues in the polycondensation ester used for this invention is 70 mol% or more, It is preferable that it is 80% or more, It is more preferable that it is 90% or more.

By making the said aromatic dicarboxylic acid residue ratio into 70 mol% or more, there exists a tendency for the cellulose acylate film which shows sufficient optical expressability (especially large value of Rth per film thickness) to show sufficient optical expression even if it is thin.

In this specification, the said aromatic dicarboxylic acid residue means the dicarboxylic acid residue containing at least 1 arylene group. That is, in the present specification, in the aromatic dicarboxylic acid residue, in addition to the -OC-Ar-CO- residue, for example, -OC-Ar'-L-CO- or -OC-L'-Ar ' Dicarboxylic acid residues having a structure such as '-CO-, -OC-L' '-Ar' ''-L ''-CO- (Ar, Ar ', Ar' 'and Ar' '' Each independently represents an arylene group, and L, L 'and L' 'each independently represent a divalent linking group other than the arylene group). As a bivalent coupling group other than the said arylene group, an aliphatic group, an atomic coupling group, etc. are mentioned, for example, An alkylene group, an alkyleneoxy group, an oxygen atom, a sulfur atom, etc. are mentioned specifically ,.

Especially, it is preferable that the said aromatic dicarboxylic acid residue is a structure of -OC-Ar-CO- residue from a compatible viewpoint with a cellulose acylate.

It is preferable that said Ar is a C6-C16 arylene group, It is more preferable that it is a C6-C12 arylene group, It is especially preferable that it is a phenylene group or a naphthylene group, It is especially preferable that it is a phenylene group. Moreover, although said Ar has a substituent further or does not need to have it, it is preferable that it does not have a substituent, As a substituent, a hydroxyl group, an acyl group, a carbonyl group, etc. are mentioned, for example.

Specific examples of the aromatic dicarboxylic acid residue include phthalic acid residue, terephthalic acid residue, isophthalic acid residue, 1,5-naphthalenedicarboxylic acid residue, 1,4-naphthalenedicarboxylic acid residue, and 1,8-naphthalenedicar Acid residues, 2,8-naphthalenedicarboxylic acid residues, 2,6-naphthalenedicarboxylic acid residues, and the like. Among these examples, phthalic acid residues, terephthalic acid residues, 2,6-naphthalenedicarboxylic acid residues are preferable, phthalic acid residues and terephthalic acid residues are more preferable, and terephthalic acid residues are more preferable.

In the said polycondensation ester, aromatic dicarboxylic acid residue is formed of the aromatic dicarboxylic acid used for mixing.

When the said polycondensation ester contains a terephthalic acid residue as an aromatic dicarboxylic acid residue, it is excellent in compatibility with a cellulose acylate more, and a bleeding-out occurs also at the time of film forming and heat drawing of a cellulose acylate film. It can be set as a difficult cellulose acylate film.

Moreover, 1 type of aromatic dicarboxylic acid residues may be contained in the said polycondensation ester, or 2 or more types may be contained. When two types of aromatic dicarboxylic acid residues are contained in the said polycondensation ester, it is preferable that a phthalic acid residue and a terephthalic acid residue are contained.

The polycondensation ester contains aliphatic dicarboxylic acid residues in addition to the aromatic dicarboxylic acid residues if the proportion of the aromatic dicarboxylic acid residues is 70 mol% or more relative to all the dicarboxylic acid residues in the polycondensation ester. You may be.

Specific examples of the aliphatic dicarboxylic acid residues include, for example, oxalic acid residues, malonic acid residues, succinic acid residues, maleic acid residues, fumaric acid residues, glutaric acid residues, adipic acid residues, pimelic acid residues, and suveric acid residues. , Azelaic acid residues, sebacic acid residues, dodecanedicarboxylic acid residues, or 1,4-cyclohexanedicarboxylic acid residues.

Aliphatic dicarboxylic acid residue is formed in the said polycondensation ester from the aliphatic dicarboxylic acid used for mixing.

It is preferable that average carbon number is 5.5-10.0, as for the said aliphatic dicarboxylic acid residue, it is more preferable that it is 5.5-8.0, It is still more preferable that it is 5.5-7.0. When the average carbon number of the aliphatic diol is 7.0 or less, it is possible to reduce the heating loss of the compound and to prevent the occurrence of a planar failure, which is thought to be caused by process contamination due to bleed-out during drying of the cellulose acylate web. Moreover, when the average carbon number of aliphatic diol is 2.5 or more, it is excellent in compatibility, and precipitation of a polycondensation ester does not occur easily, and it is preferable.

Specifically, when the said polymeric ester contains the said aliphatic dicarboxylic acid residue, it is preferable to contain a succinic acid residue or adipic acid residue, and it is more preferable to have a succinic acid residue.

In the said polycondensation ester, only 1 type of aliphatic dicarboxylic acid residue may be contained or 2 or more types may be contained. When two aliphatic dicarboxylic acid residues are contained in the said polycondensation ester, it is preferable that succinic acid residue and adipic acid residue are contained. When one type of aliphatic dicarboxylic acid residue is contained in the said polycondensation ester, it is preferable that succinic acid residue is contained. By setting it as such an aspect, the average carbon number of a diol residue can be adjusted to the said preferable range, and compatibility with a cellulose acylate becomes favorable.

Aliphatic diol residue is used as a diol residue for the said polycondensation ester.

Examples of the aliphatic diols used in the present invention include alkyldiols and alicyclic diols. Examples of the aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, and 1,3. -Butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentylglycol), 2,2-di Ethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3,3-dimethylolheptane), 3-methyl-1, 5-pentanediol, 1,6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, 1 , 9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, diethylene glycol, cyclohexanedimethanol and the like, which are preferably used as one or two or more mixtures together with ethylene glycol. Do.

Especially, in this invention, it is a cellulose whose said polycondensation ester is a polycondensation ester whose ratio of a C3 or more aliphatic diol residue with respect to all diol residues (henceforth a C3 or more aliphatic diol ratio) is 30 mol% or more. It is preferable from a viewpoint of the improvement of the compatibility of an acylate and a polycondensation ester, and the solubility improvement of the polycondensation ester to the solvent.

It is more preferable that it is 30 mol% or more, and, as for the said C3 or more aliphatic diol ratio, it is especially preferable that it is 50-80 mol%.

Examples of the aliphatic diol residue having 3 or more carbon atoms include 1,2-propanediol residue, 1,3-propanediol residue, 1,2-butanediol residue, 1,3-butanediol residue, and 2-methyl-1,3-propanediol residue , 1,4-butanediol residue, 1,5-pentanediol residue, 2,2-dimethyl1,3-propanediol (neopentyl glycol) residue, 1,4-hexanediol residue, 1,4-cyclohexanediol residue Etc. can be mentioned. Among these, as the aliphatic diol residue having 3 or more carbon atoms which is preferably used in the present invention, 1,2-propanediol residue, 1,3-propanediol residue, 1,2-butanediol residue, 1,3-butanediol residue, 2-methyl At least one of -1,3-propanediol residue, 1,4-butanediol residue, 1,5-pentanediol residue, and 2,2-dimethyl1,3-propanediol (neopentyl glycol) residue, more preferably Of 1,2-propanediol residues, 1,3-propanediol residues, 1,2-butanediol residues, 1,3-butanediol residues, 2-methyl-1,3-propanediol residues, 1,4-butanediol residues At least one species, and particularly preferably 1,2-propanediol residues.

Crystallization of polycondensation esters can be prevented by using 1,2-propanediol residues or 1,3-propanediol residues.

As a diol residue other than C3 or more aliphatic diol, when an aliphatic diol residue is used, ethylene glycol residue etc. can be used.

In the said polycondensation ester, an aliphatic diol residue is formed by the aliphatic diol used for mixing.

In the said polycondensation ester, only 1 type of aliphatic diol residue may be contained or 2 or more types may be contained. When two aliphatic diol residues are contained in the said polycondensation ester, it is preferable that a 1, 2- propanediol residue and ethylene glycol residue are contained.

The polycondensation ester may contain an aromatic diol residue in addition to an aliphatic diol residue.

As a specific example of the said aromatic diol residue, For example, a bisphenol A residue, a 1, 2- hydroxybenzene residue, a 1, 3-hydroxybenzene residue, a 1, 4- hydroxybenzene residue, 1, 4- benzene dimethanol Residues; and the like.

In this invention, it is preferable that especially the terminal is sealed by the alkyl group or the aromatic group, and it is polycondensation ester. This is effective against time-lapse deterioration in high temperature, high humidity by protecting a terminal by a hydrophobic functional group, and becomes a factor which shows the role which delays the hydrolysis of an ester group.

It is preferable to protect with a monoalcohol residue or a monocarboxylic acid residue so that both ends of the polycondensation ester of this invention may not become a carboxylic acid or an OH group.

In this case, as the monoalcohol, a substituted or unsubstituted monoalcohol having 1 to 30 carbon atoms is preferable, and methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, isopentanol, hexanol, isohexanol, cyclo Hexyl alcohol, octanol, isooctanol, 2-ethylhexyl alcohol, nonyl alcohol, isononyl alcohol, tert-nonyl alcohol, decanol, dodecanol, dodecahexanol, dodecaoctanol, allyl alcohol, oleyl alcohol, etc. And substituted alcohols such as aliphatic alcohols, benzyl alcohol, and 3-phenylpropanol.

Terminal sealing alcohols that can be preferably used are methanol, ethanol, propanol, isopropanol, butanol, isobutanol, isopentanol, hexanol, isohexanol, cyclohexyl alcohol, isooctanol, 2-ethylhexyl alcohol, isononyl Alcohol, oleyl alcohol, benzyl alcohol, and especially methanol, ethanol, propanol, isobutanol, cyclohexyl alcohol, 2-ethylhexyl alcohol, isononyl alcohol, benzyl alcohol.

In the case of encapsulating with a monocarboxylic acid residue, the monocarboxylic acid used as the monocarboxylic acid residue is preferably a substituted or unsubstituted monocarboxylic acid having 1 to 30 carbon atoms. These may be aliphatic monocarboxylic acids or aromatic ring-containing carboxylic acids. The preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butanoic acid, caprylic acid, caproic acid, decanoic acid, dodecanoic acid, stearic acid and oleic acid. Examples of the aromatic ring-containing monocarboxylic acid include Examples include benzoic acid, p-tert-butylbenzoic acid, p-tert-amylbenzoic acid, orthotoluic acid, metatoluic acid, paratoluic acid, dimethylbenzoic acid, ethylbenzoic acid, normalpropylbenzoic acid, aminobenzoic acid, acetoxybenzoic acid, and the like. These can use 1 type (s) or 2 or more types, respectively.

Although the specific example of the said polycondensation ester is described in the following Table 1, this invention is not limited to the following specific example.

(Synthesis method of polycondensation ester)

Synthesis of the polycondensation ester used in the present invention is a thermal melt condensation method by a polyesterification reaction or transesterification reaction of diol and dicarboxylic acid by a conventional method, or acid chlorides and glycols of these acids It can be synthesize | combined easily also by any method of the interfacial condensation method of the. Moreover, about the polycondensation ester which concerns on this invention, there is a detailed description in Murai Koichi horseshoe "The plasticizer the theory and application" (the Saisho Shobo Co., Ltd., the first edition of March 1, 1983). Japanese Laid-Open Patent Publication Nos. 05-155809, 05-155810, 5-197073, 2006-259494, and 07-330670 , Japanese Unexamined Patent Application Publication No. 2006-342227, Japanese Unexamined Patent Publication No. 2007-003679, and the like can be used.

&Lt; Other components &gt;

In addition to a polycondensation ester, a sugar ester, a retardation expression agent, a low molecular weight additive, etc. can be suitably used for the cellulose acylate film of this invention as needed.

(Sugar ester)

The sugar ester compound refers to a compound in which at least one of the substitutable groups (eg, hydroxyl group, carboxyl group) in the polysaccharide constituting the compound and at least one substituent group are ester-bonded. That is, the sugar ester compound mentioned here also includes a wide range of sugar derivatives, and includes compounds containing a sugar moiety such as, for example, gluconic acid as a structure. In other words, the sugar ester compound includes an ester of glucose and a carboxylic acid and an ester of gluconic acid and an alcohol.

It is preferable that the substitutable group in the polysaccharide which comprises the said sugar ester compound is a hydroxyl group.

In the said sugar ester compound, the structure (henceforth a sugar residue) derived from the polysaccharide which comprises a sugar ester compound is contained. The monosaccharide structure of the said sugar residue is called the structural unit of a sugar ester compound. It is preferable that the structural unit of the said sugar ester compound contains a pyranose structural unit or a furanose structural unit, and it is more preferable that all the sugar residues are a pyranose structural unit or a furanose structural unit. Moreover, when the said sugar ester consists of polysaccharides, it is preferable to include both a pyranose structural unit or a furanose structural unit.

Although the sugar residue of the said sugar ester compound may be derived from 5 monosaccharides or 6 monosaccharides, it is preferable that it is derived from 6 monosaccharides.

It is preferable that it is 2-4, as for the number of the structural units contained in the said sugar ester compound, it is more preferable that it is 2-3, and it is especially preferable that it is two. That is, it is preferable that the sugar which comprises the said sugar ester compound is a disaccharide-a tetrasaccharide, It is more preferable that it is a disaccharide-a trisaccharide, It is especially preferable that it is a disaccharide.

In the present invention, the sugar ester compound is more preferably a sugar ester compound including 2 to 4 pyranose structural units or furanose structural units at least one of the hydroxyl groups esterified, and at least one of the hydroxyl groups. More preferably, the dog is a sugar ester compound containing two esterified pyranose structural units or two furanose structural units.

As an example of the said monosaccharide or the sugar containing 2-4 monosaccharide units, for example, erythrose, threose, ribose, arabinose, xylose, ricose, allose, altrose, glucose, fructose Os, Mannose, Gloose, Idoose, Galactose, Talos, Trehalose, Isotrehalose, Neotrehalose, Trehalosamine, Kojibiose, Nigerose, Maltose, Multitol, Isomalose, Sophorose, Laminaribiose, Cello Vios, genthiobis, lactose, lactosamine, lactitol, lactose, melibiose, primeberose, lutinos, silaviose, sucrose, sucralose, turanose, bicyanos, cellulose, cacotlios, Gentianos, Isomaltrios, Isopanos, Maltotrios, Manninotrios, Melezitose, Panos, Planteos, Raffinose, Solartrios, Umbelliferose, Li Cotetraose, maltotetraose, starchiose, baltopentaose, verbarcose, maltohexaose, xylitol, sorbitol and the like.

Preferably, it is ribose, arabinose, xylose, lixose, glucose, fructose, mannose, galactose, trehalose, maltose, cellobiose, lactose, sucrose, sucralose, xylitol, sorbitol, and more preferably. Is arabinose, xylose, glucose, fructose, mannose, galactose, maltose, cellobiose and sucrose, and particularly preferably, xylose, glucose, fructose, mannose, galactose, maltose, cello Viose, sucrose, xylitol, sorbitol.

As a preferable example of the substituent of the said sugar ester compound, it is an alkyl group (preferably C1-C22, More preferably, it is C1-C12, Especially preferably, it is a C1-C8 alkyl group, for example, a methyl group, an ethyl group, a propyl group) , Hydroxyethyl group, hydroxypropyl group, 2-cyanoethyl group, benzyl group, etc., aryl group (preferably 6 to 24 carbon atoms, more preferably 6 to 18, particularly preferably 6 to 12 aryl groups) For example, a phenyl group, a naphthyl group, an acyl group (preferably C1-C22, More preferably, it is C2-C12, Especially preferably, it is an C2-C8 acyl group, for example, an acetyl group, propy O'Nyl group, butyryl group, pentanoyl group, hexanoyl group, octanoyl group, benzoyl group, toluyl group, phthalyl group, etc.), an amide group (preferably C1-C22, More preferably, it is C2-C12, Especially preferably, carbon 2-8 amides, such as formamide group, acetamide group, etc., imide group (preferably C4-C22, More preferably, C4-C12, Especially preferably, C4-C8 amide group For example, a succinimide group, a phthalimide group, etc. are mentioned. Especially, an alkyl group or an acyl group is more preferable, a methyl group, an acetyl group, a propionyl group, a butyryl group (among these, i-butyryl group is preferable) and a benzoyl group are more preferable, and at least one of an acetyl group and a butyryl group is included. It is particularly preferable to use one, more preferably one containing only an acetyl group or both containing an acetyl group and a butyryl group.

As a sugar ester compound used for this invention, the compound shown below is mentioned. However, the sugar ester compound which can be used by this invention is not limited to these. In addition, in the following structural formula, R respectively independently represents arbitrary substituents, and some R may be same or different.

In addition, as said sugar ester compound, Unexamined-Japanese-Patent No. 2001-247717, Unexamined-Japanese-Patent No. 2005-515285, International Publication WO2007 / 125764, International Publication WO2009 / 011228, International Publication WO2009 / 031464 The sugar ester compound described in this etc. can also be used.

As a method for obtaining the sugar ester compound, a commercially available ester derivatization method which is commercially available from Tokyo Chemical Co., Ltd., Aldrich, etc., or commercially available carbohydrates (for example, Japanese Patent Application Laid-Open No. 8). -245678) can be synthesized.

As for the said sugar ester compound, the number average molecular weight becomes like this. Preferably it is 200-3500, More preferably, it is 420-3000, Especially preferably, the range of 450-2000 is preferable.

It is preferable to contain 2-35 mass% of the said sugar ester compound with respect to a cellulose acylate, It is more preferable to contain 5-20 mass%, It is especially preferable to contain 10-15 mass%.

(Retardation expression agent)

The film of this invention may contain a retardation expression agent, in order to express a retardation value. Although there is no restriction | limiting in particular as said retardation expression agent, A rod-shaped retardation expression agent (henceforth a rod-shaped compound), or a disk-shaped retardation expression agent (henceforth a disk-shaped compound) are mentioned, Half-phase compounds are preferred. Such a disk-like compound makes it easy to express retardation, and also acts to hydrophobize the membrane, and can reduce the change in retardation before and after the water treatment.

It is preferable that it is 0.1 mass part or more and less than 3 mass parts with respect to 100 mass parts of cellulose acylate components, and, as for the addition amount of the retardation expression agent which consists of rod-shaped compounds, it is more preferable that it is 0.5 mass part or more and less than 2 mass parts. On the other hand, it is preferable that it is 0.1-10 mass% with respect to the said cellulose acylate, It is more preferable that it is 0.5-4 mass%, It is especially preferable that it is 1-3 mass%.

Since a discotic compound is superior to rod-like compound in Rth retardation expression property, it is used preferably when especially large Rth retardation is needed. You may use together two or more types of retardation expression agents.

It is preferable that a retardation expression agent has maximum absorption in the wavelength range of 250-400 nm, and it is preferable that it does not have absorption in a visible region substantially.

Discus compound is demonstrated. As the discotic compound, a compound having at least two aromatic rings can be used.

In the present specification, the "aromatic ring" includes an aromatic hetero ring in addition to the aromatic hydrocarbon ring.

The aromatic hydrocarbon ring is particularly preferably a 6 membered ring (ie, a benzene ring).

Aromatic hetero rings are generally unsaturated hetero rings. It is preferable that it is a 5-membered ring, a 6-membered ring, or a 7-membered ring, and, as for an aromatic hetero ring, it is more preferable that it is a 5-membered ring or a 6-membered ring. Aromatic hetero rings generally have the largest number of double bonds. As a hetero atom, a nitrogen atom, an oxygen atom, and a sulfur atom are preferable, and a nitrogen atom is especially preferable. Examples of aromatic hetero rings include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole Ring, pyran ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring.

As an aromatic ring, a benzene ring, a condensed benzene ring, and biphenyls are preferable. Especially 1,3,5-triazine ring is used preferably. Specifically, for example, the compound disclosed in JP 2001-166144 A is preferably used.

It is preferable that carbon number of the aromatic ring which a retardation expression agent has is 2-20, It is more preferable that it is 2-12, It is further more preferable that it is 2-8, It is most preferable that it is 2-6.

The bonding relationship between two aromatic rings can be classified into (a) forming a condensed ring, (b) directly connecting with a single bond, and (c) bonding through a linking group (because it is an aromatic ring, Spiro bonds cannot be formed). The coupling relationship may be any of (a)-(c).

Examples of the condensed ring (condensed ring of two or more aromatic rings) of (a) include indene ring, naphthalene ring, azulene ring, fluorene ring, phenanthrene ring, anthracene ring, acenaphthylene ring, biphenylene ring , Naphthacene ring, pyrene ring, indole ring, isoindole ring, benzofuran ring, benzothiophene ring, indolidine ring, benzoxazole ring, benzothiazole ring, benzoimidazole ring, benzotriazole ring, purine ring , Indazole ring, chromen ring, quinoline ring, isoquinoline ring, quinolysin ring, quinazoline ring, cinnaline ring, quinoxaline ring, phthalazine ring, pteridine ring, carbazole ring, acridine Ring, phenanthridine ring, xanthene ring, phenazine ring, phenothiazine ring, phenoxatiin ring, phenoxazine ring and thianthrene ring. Preferred are naphthalene ring, azulene ring, indole ring, benzoxazole ring, benzothiazole ring, benzoimidazole ring, benzotriazole ring and quinoline ring.

It is preferable that the single bond of (b) is a bond between carbon atoms of two aromatic rings. Two aromatic rings may be bonded by two or more single bonds to form an aliphatic ring or a non-aromatic heterocycle between the two aromatic rings.

It is preferable that the linking group of (c) also couple | bonds with the carbon atom of two aromatic rings. It is preferable that a coupling group is an alkylene group, an alkenylene group, an alkynylene group, -CO-, -O-, -NH-, -S-, or a combination thereof. An example of a connector made of a combination is shown below. In addition, the left-right relationship of the example of the following coupler may be reversed.

c1 ： -CO-O-

c2: -CO-NH-

c3: -alkylene-O-

c4 ： -NH-CO-NH-

c5 ： -NH-CO-O-

c6: -O-CO-O-

c7: -O-alkylene-O-

c8 ： -CO-alkenylene-

c9 ： -CO-alkenylene-NH-

c10: -CO-alkenylene-O-

c11: -alkylene-CO-O-alkylene-O-CO-alkylene-

c12: -O-alkylene-CO-O-alkylene-O-CO-alkylene-O-

c13: -O-CO-alkylene-CO-O-

c14: -NH-CO-alkenylene-

c15 ： -O-CO-alkenylene-

The aromatic ring and the linking group may have a substituent.

Examples of the substituent include halogen atom (F, Cl, Br, I), hydroxyl group, carboxyl group, cyano group, amino group, nitro group, sulfo group, carbamoyl group, sulfamoyl group, ureide group, alkyl group, alkenyl group , Alkynyl group, aliphatic acyl group, aliphatic acyloxy group, alkoxy group, alkoxycarbonyl group, alkoxycarbonylamino group, alkylthio group, alkylsulfonyl group, aliphatic amide group, aliphatic sulfonamide group, aliphatic substituted amino group, aliphatic substituted carbamoyl group , Aliphatic substituted sulfamoyl groups, aliphatic substituted uraid groups and non-aromatic heterocyclic groups.

It is preferable that carbon number of an alkyl group is 1-8. A chain alkyl group is more preferable than a cyclic alkyl group, and a linear alkyl group is especially preferable. The alkyl group may further have a substituent (for example, a hydroxyl group, a carboxy group, an alkoxy group, an alkyl substituted amino group). Examples of the alkyl group (including a substituted alkyl group) include methyl group, ethyl group, n-butyl group, n-hexyl group, 2-hydroxyethyl group, 4-carboxybutyl group, 2-methoxyethyl group and 2-diethylaminoethyl group Each group of is included.

It is preferable that carbon number of an alkenyl group is 2-8. A chain alkenyl group is more preferable than a cyclic alkenyl group, and a linear alkenyl group is especially preferable. The alkenyl group may further have a substituent. Examples of the alkenyl group include a vinyl group, allyl group, and 1-hexenyl group.

It is preferable that carbon number of an alkynyl group is 2-8. A chain alkynyl group is more preferable than a cyclic alkynyl group, and a linear alkynyl group is especially preferable. The alkynyl group may further have a substituent. Examples of the alkynyl group include an ethynyl group, 1-butynyl group and 1-hexynyl group.

It is preferable that carbon number of an aliphatic acyl group is 1-10. Examples of aliphatic acyl groups include acetyl groups, propanoyl groups and butanoyl groups.

It is preferable that carbon number of an aliphatic acyloxy group is 1-10. Examples of aliphatic acyloxy groups include acetoxy groups.

It is preferable that carbon number of an alkoxy group is 1-8. The alkoxy group may further have a substituent (for example, an alkoxy group). Examples of the alkoxy group (including a substituted alkoxy group) include a methoxy group, an ethoxy group, a butoxy group and a methoxyethoxy group.

It is preferable that carbon number of an alkoxycarbonyl group is 2-10. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group.

It is preferable that carbon number of the alkoxycarbonylamino group is 2-10. Examples of the alkoxycarbonylamino group include a methoxycarbonylamino group and an ethoxycarbonylamino group.

It is preferable that carbon number of an alkylthio group is 1-12. Examples of the alkylthio group include methylthio group, ethylthio group and octylthio group.

It is preferable that carbon number of an alkylsulfonyl group is 1-8. Examples of the alkylsulfonyl group include a methanesulfonyl group and an ethanesulfonyl group.

It is preferable that carbon number of an aliphatic amide group is 1-10. Examples of aliphatic amide groups include acetamide.

It is preferable that carbon number of an aliphatic sulfonamide group is 1-8. Examples of aliphatic sulfonamide groups include methanesulfonamide groups, butanesulfonamide groups and n-octanesulfonamide groups.

It is preferable that carbon number of an aliphatic substituted amino group is 1-10. Examples of the aliphatic substituted amino group include a dimethylamino group, diethylamino group and 2-carboxyethylamino group.

It is preferable that carbon number of an aliphatic substituted carbamoyl group is 2-10. Examples of aliphatic substituted carbamoyl groups include methylcarbamoyl groups and diethylcarbamoyl groups.

It is preferable that carbon number of an aliphatic substituted sulfamoyl group is 1-8. Examples of the aliphatic substituted sulfamoyl group include a methyl sulfamoyl group and a diethyl sulfamoyl group.

It is preferable that carbon number of an aliphatic substituted ureide group is 2-10. Examples of the aliphatic substituted ureide group include a methyl ureide group.

Examples of the nonaromatic heterocyclic group include a piperidino group and a morpholino group.

It is preferable that the molecular weight of a retardation expression agent is 300-800.

In this invention, it is preferable to use the triazine compound represented by following General formula (I) as said disk shaped compound.

The compound of formula (I)

In said general formula (I):

R²⁰¹ Each independently represents an aromatic ring or a heterocyclic ring having a substituent at at least any one of an ortho position, a meta position and a para position.

X ²⁰¹ Each independently represents a single bond or -NR ^202- . Where R ²⁰² Each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group, or a heterocyclic group.

R ²⁰¹ It is preferable that this aromatic ring is phenyl or naphthyl, and it is especially preferable that it is phenyl. R ²⁰¹ This aromatic ring may have at least one substituent at any substitution position. Examples of the substituent include halogen atoms, hydroxyl groups, cyano groups, nitro groups, carboxyl groups, alkyl groups, alkenyl groups, aryl groups, alkoxy groups, alkenyloxy groups, aryloxy groups, acyloxy groups, alkoxycarbonyl groups and alkenyloxy Carbonyl group, aryloxycarbonyl group, sulfamoyl group, alkyl substituted sulfamoyl group, alkenyl substituted sulfamoyl group, aryl substituted sulfamoyl group, sulfonamide group, carbamoyl, alkyl substituted carbamoyl group, alkenyl substituted carbamoyl group, Aryl substituted carbamoyl groups, amide groups, alkylthio groups, alkenylthio groups, arylthio groups and acyl groups are included.

R ²⁰¹ It is preferable that the heterocyclic group which this represents has aromaticity. The heterocyclic ring having aromaticity is generally an unsaturated heterocyclic ring, preferably a heterocyclic ring having the largest double bond. 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. It is preferable that the hetero atom of a hetero ring is a nitrogen atom, a sulfur atom, or an oxygen atom, and it is especially preferable that it is a nitrogen atom. As a heterocyclic ring which has aromaticity, a pyridine ring (as a heterocyclic group, 2-pyridyl or 4-pyridyl) is especially preferable. The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group are the same as those of the substituent of the aryl moiety.

X ²⁰¹ It is preferable that the heterocyclic group in the case of this single bond is a heterocyclic group which has a free valency in a nitrogen atom. It is preferable that the heterocyclic group which has a free valency in a nitrogen atom is a 5-membered ring, a 6-membered ring, or a 7-membered ring, It is more preferable that it is a 5-membered ring or a 6-membered ring, It is most preferable that it is a 5-membered ring. The heterocyclic group may have a plurality of nitrogen atoms. Moreover, the heterocyclic group may have hetero atoms (for example, O and S) other than a nitrogen atom. Below, the example of the heterocyclic group which has a free valency in a nitrogen atom is shown. Where -C ₄ H ₉ ⁿ Represents nC ₄ H ₉ .

R ²⁰² Although the alkyl group which is represented may be a cyclic alkyl group or a chain alkyl group, a linear alkyl group is preferable and a linear alkyl group is more preferable than a branched chain alkyl group. The number of carbon atoms in the alkyl group is preferably 1 to 30, more preferably 1 to 20, still more preferably 1 to 10, still more preferably 1 to 8, and most preferably 1 to 6 . The alkyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (eg, methoxy group, ethoxy group) and an acyloxy group (eg, acryloyloxy group, methacryloyloxy group).

R ²⁰² Although the alkenyl group which may represent may be a cyclic alkenyl group or a linear alkenyl group, it is preferable to represent a chain alkenyl group, and it is more preferable to represent a linear alkenyl group rather than a branched chain alkenyl group. The number of carbon atoms of 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, and most preferably 2 to 6 desirable. The alkenyl group may have a substituent. In the example of a substituent, it is the same as the substituent of the alkyl group mentioned above.

R ²⁰² The aromatic ring group and the heterocyclic group represented by R ²⁰¹ It is the same as the aromatic ring and heterocyclic ring which are shown, and its preferable range is also the same. The aromatic ring group and the heterocyclic group may further have a substituent, and examples of the substituent are the same as the substituents of the aromatic ring and hetero ring of R ²⁰¹ .

The compound represented by general formula (I) can be synthesize | combined by a well-known method, such as the method of Unexamined-Japanese-Patent No. 2003-344655, for example. Details of the retardation expression agent are described on page 49 of Publication 2001-1745.

Moreover, in addition to the said compound, you may contain the compound represented by following formula (II-1).

In general formula (II-1)

(In the general formula ^(II-1), Y 1 represents a methine group, or -N-. Ra ³¹ is an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic ring. ³¹ Rb, Rc ^31, Rd ³¹ And Re ³¹ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, Q ²¹ represents a single bond, -O-, -S-, or -NRf-, and Rf represents hydrogen An atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group; Ra ³¹ It may connect with and form a ring. X ³¹ , X ³² , and X ³³ Each independently represents a single bond or a divalent linking group. X ³⁴ Is the following general formula (Q)

General formula (Q)

(In general formula (Q), * side is a connection site with N atom substituted by the heterocyclic ring in the compound represented by the said General formula (II-1).)

Represents a linking group selected from the group consisting of divalent linking groups.

Although the specific example of an optical expression agent is given to the following, this invention is not limited by the following specific example.

(Low molecular weight additives)

As a low molecular weight additive, an Rth control agent and a regulator, a deterioration inhibitor, a ultraviolet inhibitor, another plasticizer, an infrared absorber, etc. are mentioned. These may be solid or an oily substance may be sufficient as them. That is, it is not specifically limited in the melting point or boiling point. For example, it mixes 20 degrees C or less and 20 degrees C or more ultraviolet absorbing material, similarly mixes deterioration inhibitor, etc. Moreover, as an infrared absorbing dye, it is described, for example in Unexamined-Japanese-Patent No. 2001-194522. Moreover, although the addition time may be added anywhere in a cellulose acylate solution (dope) manufacturing process, you may add and add the process of adding and preparing an additive to the last preparation process of a dope preparation process. In addition, the amount of each material added is not particularly limited as long as the function is expressed.

In the polymer solution, a deterioration inhibitor (for example, an antioxidant, a peroxide decomposing agent, a radical inhibitor, a metal deactivator, an acid trapping agent, and an amine) may be added. About the said antideterioration agent, Unexamined-Japanese-Patent No. 3-199201, 5-197073, 5-194789, 5-271471, and 6-107854 have description. The addition amount of the said degradation inhibitor is 0.01-1 mass% of the solution (dope) prepared from the viewpoint of the effect by the addition of the degradation inhibitor, and suppressing the bleed out (bleeding) of the said degradation inhibitor with respect to the film surface. It is preferable, and it is more preferable that it is 0.01-0.2 mass%. Examples of particularly preferred deterioration inhibitors include butylated hydroxytoluene (BHT) and tribenzylamine (TBA).

In the polymer solution, a known plasticizer other than the polycondensation ester may be added to improve the mechanical properties or to improve the drying rate. Phosphoric acid ester or carboxylic acid ester is used as said plasticizer. Examples of the phosphate ester include triphenyl phosphate (TPP) and tricresyl phosphate (TCP). Phthalic acid ester and citric acid ester are typical as carboxylic acid ester. Examples of phthalate esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethylhexyl phthalate (DEHP). . Examples of citric acid ester include O-acetyl citrate triethyl (OACTE) and O-acetyl citrate tributyl (OACTB). Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Phthalate ester plasticizers (DMP, DEP, DBP, DOP, DPP, DEHP) are preferably used. DEP and DPP are particularly preferred. It is preferable that the addition amount of a plasticizer is 0.1-25 mass% of the quantity of cellulose acylate, It is more preferable that it is 1-20 mass%, It is most preferable that it is 3-15 mass%.

(Fine particles made of mat)

In the said polymer solution, it is preferable to contain microparticles | fine-particles as a mat agent. Examples of the fine particles that can be used in the present invention include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, calcium silicate hydrate, aluminum silicate, magnesium silicate and calcium phosphate. have. It is preferable that the fine particles include silicon because the turbidity is lowered, and silicon dioxide is particularly preferable. It is preferable that the microparticles | fine-particles of silicon dioxide have a primary average particle diameter of 20 nm or less, and an apparent specific gravity is 70 g / L or more. It is more preferable that the average diameter of a primary particle is 5-16 nm as small as it can lower the haze of a film. The apparent specific gravity is preferably 90 to 200 g / l, more preferably 100 to 200 g / l. The larger the apparent specific gravity, the more desirable it is to make a high-concentration dispersion, and the haze and agglomerates are quantified. Preferred embodiments are described in detail in pages 35 to 36 of the Invention Association Publication (Publication No. 2001-1745, published March 15, 2001, Invention Association), and a method for producing the cellulose acylate film of the present invention. It can also be used preferably.

In addition to the above, you may mix | blend another additive with the cellulose acylate film of this invention within the range which does not deviate from the meaning of this invention. Specifically, a peeling accelerator, a deterioration inhibitor, etc. are illustrated.

<Characteristics of Cellulose Acylate Film>

(Layer Structure of Cellulose Acylate Film)

Although the film of this invention may be a single | mono layer film, or may have a laminated structure of two or more layers, it is preferable that it is a single | mono layer film.

(Film thickness)

The film thickness of this invention is 15-45 micrometers. Thus, by setting it as a thin cellulose acylate film, a thin polarizing plate and a thin liquid crystal display device are obtained. It is preferable that it is 20-40 micrometers, and, as for the film thickness of the film of this invention, it is more preferable that it is 22-30 micrometers. When the film of this invention is a laminated film, the range of the total film thickness of a film is the said preferable range.

(Film width)

It is preferable that the film width of this invention is 1000 mm or more, It is more preferable that it is 1500 mm or more, It is especially preferable that it is 1800 mm or more.

(ΔRth before and after the water contact test)

As for the cellulose acylate film of this invention, the absolute value of (DELTA) Rth after performing a water contact test is 5 nm or less, 4 nm or less is preferable, and its 3 nm or less is more preferable. Moreover, it is more preferable that the value of (DELTA) Rth is 0-3 nm. Such (DELTA) Rth adjusts extending | stretching conditions (remaining solvent amount and extending | stretching temperature at the start of extending | stretching) in manufacture of a cellulose acylate film, or the compounding quantity of the aromatic dicarboxylic acid group in the polycondensation ester contained in a cellulose acylate film. It can achieve by making it into 70 mol% or more.

(Re, Rth)

It is preferable that the retardation of the in-plane and film thickness direction in wavelength 550 nm of the film of this invention satisfy | fills following formula (1) and (2).

Equation (1) 40 nm ≤ Re (550) ≤ 80 nm

(In Formula (1), Re (550) represents the retardation of the in-plane direction in wavelength 550 nm.)

Equation (2) 100 nm ≤ Rth (550) ≤ 300 nm

(In Formula (2), Rth (550) represents the retardation of the film thickness direction in wavelength 550nm.)

It is preferable to express retardation in such a range from the viewpoint of the improvement of contrast and black taste change of a liquid crystal display device.

It is preferable that it is 40-65 nm, and, as for said Re (550), it is more preferable that it is 45-60 nm.

It is preferable that the said Rth (550) is 100-300 nm, It is more preferable that it is 100-230 nm, It is still more preferable that it is 105-150 nm.

(Rth / d)

In this invention, when the film thickness of a film is set to dnm, Rth / d is 0.0025 or more and can also be 0.0030 or more. High Rth / d means high retardation expression. Such high retardation expressability adjusts stretching conditions (remaining solvent amount and stretching temperature at the start of stretching) in the production of the cellulose acylate film, or aromatic dicarboxyl in the polycondensation ester contained in the cellulose acylate film. It can achieve by making the compounding quantity of an acidic radical into 70 mol% or more.

In addition, the film thickness in this invention says an average film thickness.

Re (λ) and Rth (λ) in the present specification indicate in-plane retardation and retardation in the thickness direction, respectively, at the wavelength λ. In this specification, when there is no description in particular, wavelength (lambda) shall be 550 nm. Re (λ) is measured by injecting light having a wavelength of λnm in the film normal line direction in KOBRA 21ADH (manufactured by Oji Measuring Instruments Co., Ltd.). Rth (λ) is the Re (λ) of the in-plane slow axis (judged by KOBRA 21ADH) as the inclination axis (rotation axis) (when there is no ground axis, any direction in the film plane is the rotation axis) In total, six points were measured by injecting light having a wavelength of λnm from the inclined direction in 10 degree steps from the normal direction to the 50 degree one side with respect to the film normal direction, and the measured values of the retardation value and average refractive index, KOBRA 21ADH is calculated based on the film thickness value. In addition, the retardation value is measured from the arbitrary two directions as a slow axis as an inclination axis (rotation axis) (when there is no ground axis, arbitrary direction in a film plane), and the assumption value of the value and an average refractive index, and Rth can also be calculated from the following formulas (A) and (B) based on the input film thickness value. The assumption of the average refractive index can use the value of the catalog of a polymer handbook (JOHN WILEY & SONS, INC) and various optical films. If the value of the average refractive index is not already known, it can be measured with an Abbe refractometer. The value of the average refractive index of a main optical film is illustrated below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59). By inputting the assumption values and the film thicknesses of these average refractive indices, KOBRA 21ADH calculates nx, ny, and nz. From this calculated nx, ny, and nz, Nz = (nx-nz) / (nx-ny) is also calculated.

The formula (A)

Here, Re (theta) represents the retardation value in the direction which inclined angle (theta) from a normal direction, nx, ny, and nz represent the refractive index of each main-axis orientation of a refractive index ellipsoid, and d represents a film thickness .

Rth = ((nx + ny) / 2-nz) × d Formula (B)

In addition, at this time, although the average refractive index n is needed as a parameter, this used the value measured by the Abbe refractometer ("Abe refractometer 2-T" by the Atago Co., Ltd.).

(Internal haze)

As for the cellulose acylate film of this invention, it is preferable that internal haze is 0.05% or less, It is more preferable that it is 0.04% or less, It is more preferable that it is 0.35% or less.

Haze represents haze value (%) measured according to JISK7136.

The internal haze of the film of this invention was dripped several drops of glycerin on both surfaces of the obtained cellulose acylate film, and was measured in the state sandwiched between both sides by the glass plate (made by MICRO SLIDE GLASS part number S9213, MATSUNAMI) of thickness 1.3mm. From the haze value (%), the value (%) which subtracted the haze measured in the state which dripped several drops of glycerin between two glass sheets is shown.

Haze of the cellulose acylate film of this invention was measured in the same environment in the film left to stand for 24 hours in 23 degreeC and 55% of relative humidity conditions using the turbidimeter (NDH2000, Nippon Denshoku Industries Co., Ltd.). .

The low haze is generally considered to be preferable. In addition, simply lowering the overall haze is insufficient to improve the front contrast, and it is preferable to adjust the internal haze within the above range from the viewpoint of improving the front contrast of the liquid crystal display device.

(Dimensional change rate)

As for the film of this invention, it is more preferable that the rate of dimensional change before and after passing for 24 hours at 60 degreeC relative humidity 90% satisfies following formula (7) in a film conveyance direction and the direction orthogonal to it.

-0.5% ≤ ｛(L'-L0) / L0｝ × 100 ≤ 0.5% (7)

L0 represents the film length after humidity adjustment for 2 hours or more in the atmosphere of 25 degreeC and 60% of a relative humidity, L 'represents the film length after adjusting for 24 hours at 90% of 60 degreeC relative humidity, and again controlling humidity for 2 hours. .

When the dimensional change rate is in the range of the formula (7), since the dimensional change of the film hardly occurs in the alkali saponification process, wrinkles and mixing of air can be suppressed in the bonding process of the polarizing plate. As for the said dimensional change rate, it is more preferable that it is -0.4 to 0.4%, and it is especially preferable that it is -0.2 to 0.2%.

<The manufacturing method of a cellulose acylate film>

The cellulose acylate film of this invention can employ | adopt a widely known method of manufacturing a cellulose ester film, etc., and it is preferable to manufacture by the solvent casting method. In the solvent cast method, a film can be manufactured using the solution (dope) which melt | dissolved the cellulose acylate in the organic solvent.

It is preferable that the organic solvent contains the solvent chosen from the ether of 3-12 carbon atoms, the ketone of 3-12 carbon atoms, the ester of 3-12 carbon atoms, and the halogenated hydrocarbon of 1-6 carbon atoms. . The ether, ketone and ester may have a cyclic structure. The compound which has two or more of functional groups (that is, -O-, -CO-, and -COO-) of an ether, a ketone, and ester can also be used as an organic solvent. The organic solvent may have other functional groups, such as an alcoholic hydroxyl group. In the case of the organic solvent which has two or more types of functional groups, the carbon atom number should just be in the prescribed range of the compound which has any functional group.

Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phentol This includes.

Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclohexanone and methylcyclohexanone.

Examples of esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate.

Examples of the organic solvent having two or more functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol.

The number of carbon atoms of the halogenated hydrocarbon is preferably 1 or 2, most preferably 1. The halogen of the halogenated hydrocarbon is preferably chlorine. The proportion of the halogenated hydrocarbon in which the hydrogen atom is substituted with halogen is preferably 25 to 75 mol%, more preferably 30 to 70 mol%, still more preferably 35 to 65 mol%, and more preferably 40 to 60 mol% % Is most preferable. Methylene chloride is a representative halogenated hydrocarbon.

You may mix and use two or more types of organic solvents.

A cellulose acylate solution can be prepared by a general method. The general method means treatment at a temperature of 0 占 폚 or higher (room temperature or high temperature). The solution can be prepared by using a method and apparatus for preparing dope in a conventional solvent casting method. In the case of a general method, it is preferable to use a halogenated hydrocarbon (particularly methylene chloride) as the organic solvent.

The amount of cellulose acylate is adjusted to contain 10-40 mass% in the solution obtained. The amount of cellulose acylate is more preferably 10 to 30% by mass. In the organic solvent (main solvent), you may add the arbitrary additive mentioned later.

A solution can be prepared by stirring a cellulose acylate and an organic solvent at normal temperature (0-40 degreeC). The high concentration solution may be stirred under pressurized and heated conditions. Specifically, the cellulose acylate and the organic solvent are placed in a pressurized container and sealed, and the mixture is stirred while heating to a temperature not lower than the boiling point at normal temperature of the solvent and not boiling the solvent. The heating temperature is usually 40 占 폚 or higher, preferably 60 to 200 占 폚, and more preferably 80 to 110 占 폚.

Each ingredient may be preliminarily mixed thoroughly and then placed in a container. In addition, it may be charged in a sequential container. The vessel needs to be configured to be able to stir. The vessel can be pressurized by injecting an inert gas such as nitrogen gas. Moreover, you may use the raise of the vapor pressure of a solvent by heating. Alternatively, after sealing the container, each component may be added under pressure.

When heating, it is preferable to heat from the exterior of a container. For example, a jacket type heating device can be used. It is also possible to heat the entire container by providing a plate heater on the outside of the container and piping to circulate the liquid.

It is preferable to provide a stirring blade inside a container and to stir using this. It is preferable that the agitating blade has a length reaching the vicinity of the wall of the container. In order to update the liquid film of the wall of a container, it is preferable to provide a scraper blade at the end of the stirring blade.

Instrumentation such as pressure gauge, thermometer, etc. may be installed in the container. Each component is dissolved in a solvent in a container. The prepared dope is taken out of the container after cooling, or after it is taken out and cooled using a heat exchanger or the like.

The solution may also be prepared by a cooling dissolution method. In the cooling dissolution method, the cellulose acylate can be dissolved in an organic solvent that is difficult to dissolve by the usual dissolution method. Moreover, even if it is a solvent which can melt | dissolve a cellulose acylate by a normal dissolution method, there exists an effect that a uniform solution can be obtained quickly by a cooling dissolution method.

In the cooling solution method, first, the cellulose acylate is gradually added while stirring in an organic solvent at room temperature. It is preferable to adjust the quantity of cellulose acylate so that it may contain 10-40 mass% in this mixture. The amount of cellulose acylate is more preferably 10 to 30% by mass. Further, optional additives described below may be added to the mixture.

Next, the mixture is cooled to -100 to -10 占 폚 (preferably -80 to -10 占 폚, more preferably -50 to -20 占 폚, most preferably -50 to -30 占 폚). Cooling can be performed, for example in a dry ice methanol bath (-75 degreeC) or the cooled diethylene glycol solution (-30--20 degreeC). When it cools in this way, the mixture of a cellulose acylate and an organic solvent will solidify.

It is preferable that a cooling rate is 4 degree-C / min or more, It is more preferable that it is 8 degree-C / min or more, It is most preferable that it is 12 degree-C / min or more. Although a cooling rate is so preferable that it is quick, 10000 degree-C / sec is a theoretical upper limit, 1000 degree-C / sec is a technical upper limit, and 100 degree-C / sec is a practical upper limit. The cooling rate is a value obtained by dividing the difference between the temperature at the start of cooling and the final cooling temperature by the time from the start of cooling until the final cooling temperature is reached.

Moreover, when this is heated to 0-200 degreeC (preferably 0-150 degreeC, More preferably, 0-120 degreeC, most preferably 0-50 degreeC), a cellulose acylate will melt | dissolve in an organic solvent. The heating may be left at room temperature or warmed in a warm bath. It is preferable that a heating rate is 4 degree-C / min or more, It is more preferable that it is 8 degree-C / min or more, It is most preferable that it is 12 degree-C / min or more. Although a heating rate is so preferable that it is quick, 10000 degree-C / sec is a theoretical upper limit, 1000 degree-C / sec is a technical upper limit, and 100 degree-C / sec is a practical upper limit. The heating rate is a value obtained by dividing the difference between the temperature at the start of heating and the final heating temperature by the time from the start of heating until the final heating temperature is reached.

Thus, a uniform solution can be obtained. Further, when the dissolution is insufficient, the operation of cooling and heating may be repeated. Whether or not dissolution is sufficient can be judged only by visually observing the appearance of the solution.

In the cooling dissolution method, it is preferable to use a sealed container in order to avoid moisture mixing due to condensation during cooling. Further, in the cooling and warming operation, when the pressure is applied during cooling and the pressure is reduced during warming, the dissolving time can be shortened. In order to perform pressurization and depressurization, it is preferable to use a pressure-resistant container.

In addition, the 20 mass% solution which melt | dissolved the cellulose acylate (total acetyl substitution degree: 60.9%, viscosity average degree of polymerization: 299) in methyl acetate by the cooling dissolution method according to the differential scanning calorimetry (DSC) is near 33 degreeC. The pseudo phase transition point of a sol state and a gel state exists, and it becomes a uniform gel state below this temperature. Therefore, it is necessary to store this solution at a temperature above the pseudo phase transition temperature, preferably at a temperature of about 10 ° C plus the gel phase transition temperature. However, this pseudo phase transition temperature changes with the total acetyl substitution degree of a cellulose acylate, viscosity average polymerization degree, solution concentration, and the organic solvent to be used.

From the prepared cellulose acylate solution (dope), a cellulose acylate film can be manufactured by the solvent casting method.

The dope is flexible on a drum or a band, and evaporates a solvent to form a film. As for the dope before casting | flow_spread, it is preferable to adjust density | concentration so that solid content may be 18-35 mass%. The surface of the drum or band is preferably finished in a mirror-finished state. For the casting and drying method in the solvent cast method, U.S. Patents 2336310, 2367603, 2492078, 2492977, 2492978, 22607704, 2739069, 2727070, and British Patent 640731 And Japanese Unexamined Patent Publication Nos. 45-4554, 49-5614, 60-176834, 60-203430, and 62-115035.

The dope is preferably flexible on a drum or band having a surface temperature of 10 DEG C or less. It is preferable to air dry for 2 seconds or more after being soft. The obtained film may be peeled off from the drum or the band, and further dried by hot air with a sequential temperature change from 100 ° C to 160 ° C to evaporate the residual solvent. The above-described method is disclosed in Japanese Patent Application Laid-Open No. 5-17844. According to this method, it is possible to shorten the time from peeling to peeling. In order to carry out this method, it is necessary that the dope gels at the surface temperature of the drum or band at the time of softening.

A plasticizer can be added to a cellulose ester film in order to improve mechanical properties or to improve a drying speed. As the plasticizer, phosphoric acid ester or carboxylic acid ester is used. Examples of the phosphate ester include triphenyl phosphate (TPP) and tricresyl phosphate (TCP). Phthalic acid ester and citric acid ester are typical as carboxylic acid ester. Examples of phthalate esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethylhexyl phthalate (DEHP). . Examples of citric acid ester include O-acetyl citrate triethyl (OACTE) and O-acetyl citrate tributyl (OACTB). Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Phthalate ester plasticizers (DMP, DEP, DBP, DOP, DPP, DEHP) are preferably used. DEP and DPP are particularly preferred. It is preferable that the addition amount of a plasticizer is 0.1-25 mass% of the quantity of cellulose acylate, It is more preferable that it is 1-20 mass%, It is most preferable that it is 3-15 mass%.

A deterioration inhibitor (for example, antioxidant, peroxide decomposer, radical inhibitor, metal deactivator, acid trapping agent, and amine) may be added to the cellulose acylate film. The deterioration inhibitor is described in Japanese Unexamined Patent Publications No. 3-199201, 5-197073, 5-194789, 5-271471, and 6-107854. It is preferable that the addition amount of a deterioration inhibitor is 0.01-1 mass% of the solution (dope) prepared from a viewpoint which the effect by the deterioration inhibitor addition expresses, and suppresses the bleed out (bleeding out) of the deterioration inhibitor to the film surface. And it is more preferable that it is 0.01-0.2 mass%. Particularly preferred examples of the deterioration inhibitor include butylated hydroxytoluene (BHT) and tribenzylamine (TBA).

The drying method of a web dried and peeled on a drum or a belt is described. The web peeled off at the peeling position just before the drum and the belt are rotated by one turn is alternately passed through the roll group arranged in a zigzag form and conveyed, or the method of gripping both ends of the peeled web with a clip or the like and conveying it in a non-contact manner. Conveyed by Drying is performed by the method of making wind of predetermined temperature apply to both surfaces of the web (film) in conveyance, the method of using heating means, such as a microwave. Since rapid drying may impair the planarity of the film formed, in the initial stage of drying, it is preferable to dry at the temperature which does not foam a solvent, and to dry at high temperature after drying advances. In the drying process after peeling from a support body, a film tries to shrink | contract in the longitudinal direction or the width direction by evaporation of a solvent. Shrinkage becomes large as it dries at high temperature. Drying while suppressing this shrinkage as much as possible is preferable in order to improve the planarity of the finished film. In this regard, for example, as shown in Japanese Patent Laid-Open No. 62-46625, a method for carrying out the whole drying process or a part of the drying process while maintaining both ends of the width of the web with a clip or pin in the width direction. (Tenter system) is preferable. It is preferable that the drying temperature in the said drying process is 100-145 degreeC. Although drying temperature, dry air volume, and drying time differ according to the solvent to be used, what is necessary is just to select suitably according to the kind and combination of solvents used. In manufacture of the said cellulose acylate film, the web (film) peeled from a support body is extended | stretched when the residual solvent amount in a web is 35-65 mass% residual solvent (preferably 35-40 mass%). By setting it as such residual solvent amount and extending | stretching at low temperature as mentioned later, it becomes possible to lower internal haze.

The residual solvent amount can be represented by the following formula.

Residual solvent amount (mass%) = ｛(M-N) / N｝ × 100

Where M is the mass of the web at any point in time and N is the mass of the web measured at 110 ° C for 3 hours. If the amount of residual solvent in the web is too large, the effect of stretching is not obtained. If the amount is too small, the stretching may be significantly difficult, resulting in breakage of the web.

(Stretching)

Preferably the film of this invention is extended | stretched in the state of 35-65 mass% of residual solvent amount. As for extending | stretching temperature, Tg-70-Tg-30 degreeC (Tg is more preferable glass transition temperature (unit: degreeC) of a cellulose acylate film)). In the present invention, since the stretching is performed at such a low temperature, the retardation developing ability can be improved.

In this invention, it is preferable to convey by extending | stretching with a tension of 100 N / m or less, and to stretch, holding both ends of a cellulose acylate film. The tension is preferably 70 N / m or less. Moreover, although a lower limit is not specifically determined, 40 N / m or more is preferable.

It is preferable that it is 10 to 50%, and, as for a draw ratio, it is more preferable that it is 15 to 40%. In addition, the stretching may be carried out in the longitudinal direction, in the transverse direction, or in both directions, and preferably at least in the transverse direction. By making a draw ratio 10% or more, Re can be expressed more suitably and bowing can be made favorable. Moreover, haze can be reduced by making draw ratio into 50% or less.

The winding machine generally used can be used for the winding machine which winds up the obtained film, and can be wound up by the winding methods, such as the constant tension method, the constant torque method, the taper tension method, and the program tension control method with constant internal stress. In the optical film roll obtained as mentioned above, it is preferable that the slow-axis direction of a film is +/- 2 degree with respect to a winding direction (the longitudinal direction of a film), and it is preferable that it is the range of +/- 1 degree. Or it is preferable that it is +/- 2 degree with respect to the direction orthogonal to the winding direction (width direction of a film), and it is preferable to exist in the range of +/- 1 degree. It is preferable that especially the slow-axis direction of a film is within +/- 0.1 degree with respect to the winding direction (the longitudinal direction of a film). Or within ± 0.1 degrees with respect to the width direction of the film.

<Polarizer>

Although the cellulose acylate film of this invention functions as a retardation film, It is preferable to insert as a protective film of a polarizing plate preferably.

That is, the polarizing plate of this invention contains at least one cellulose acylate film of this invention as a 1st polarizing plate protective film in at least one side of a polarizer and this polarizer, and contains a 2nd polarizing plate protective film in the other side of the polarizer. do. Hereinafter, the polarizing plate of this invention is demonstrated.

Similarly to the film of the present invention, the aspect of the polarizing plate of the present invention is not only a polarizing plate of the aspect of the film piece cut into a size that can be inserted directly into the liquid crystal display device, but also produced in a long shape by continuous production and rolled up in a roll shape. The polarizing plate of a true aspect (for example, aspect of 2500 m or more of roll length or 3900 m or more) is also included. In order to use for a big screen liquid crystal display device, as above-mentioned, it is preferable that the width of a polarizing plate shall be 1470 mm or more.

In the polarizing plate of this invention, it is preferable that the film thickness of a polarizer is 3-20 micrometers, and it is more preferable that it is 5-20 micrometers.

In the polarizing plate of this invention, although at least one side of a 1st polarizing plate protective film contains the cellulose acylate film of this invention, a well-known cellulose acylate film can be used as another 2nd polarizing plate protective film. It is preferable that it is 10-40 micrometers, and, as for the thickness of the other 2nd polarizing plate protective film, it is more preferable that it is 10-29 micrometers.

Moreover, it is preferable that the total thickness of the polarizing plate of this invention is 40-100 micrometers, It is more preferable that it is 50-100 micrometers, It is especially preferable that it is 65-95 micrometers. The total thickness here is in addition to the polarizer and the polarizing plate protective film bonded to the both sides of this polarizer, and is the meaning containing the adhesive bond layer which bonds this polarizing plate protective film.

There is no restriction | limiting in particular about the specific structure of the polarizing plate of this invention, A well-known structure can be employ | adopted, For example, the structure of FIG. 6 of Unexamined-Japanese-Patent No. 2008-262161 can be employ | adopted.

<2nd polarizing plate protective film>

As a 2nd polarizing plate protective film, the film which consists of thermoplastic resins other than a cellulose acylate film can also be used. Examples of the optimal thermoplastic resins include (meth) acrylic resins, polycarbonate resins, polystyrene resins, olefin resins, glutaric anhydride resins, glutarimide resins, and the like. It can select from mixed resin of resin (However, the said (meth) acrylic-type resin contains a lactone ring containing polymer.).

It is preferable to use the film whose water vapor transmission rate (40 degreeC90% RH) prescribed | regulated to JISZ0208 especially 100 g / m <2> * 24hr or less. When water vapor transmission rate is 100 g / m <2> * 24hr, entry of water to a polarizer and a 1st polarizing plate protective film can be delayed, and generation | occurrence | production of the nonuniformity which is a subject of this invention can be reduced. As these films, a polyester film, a cycloolefin film, a polycarbonate film, a polyolefin film is mentioned.

The (meth) acrylic resin is a concept including both a methacrylic resin and an acrylic resin. The (meth) acrylic resin also includes derivatives of acrylate / methacrylate, particularly (co) polymers of acrylate ester / methacrylate ester.

((Meth) acrylic resin)

The repeating structural unit of the (meth) acrylic acid resin is not particularly limited. The (meth) acrylic acid resin preferably has a repeating structural unit derived from a (meth) acrylic acid ester monomer as a repeating structural unit.

The (meth) acrylic acid-based resin further includes a repeating structural unit formed by polymerizing at least one selected from a hydroxyl group-containing monomer, an unsaturated carboxylic acid and a monomer represented by the following general formula (201) as a repeating structural unit. You may include it.

General formula (201)

CH ₂ = C (X) R ²⁰¹

In the formula, R ²⁰¹ represents a hydrogen atom or a methyl group, X represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, a -CN group, and -CO-R ²⁰² Or -O-CO-R ²⁰³ Group and R ²⁰² and R ²⁰³ Represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms.)

Although it does not specifically limit as said (meth) acrylic acid ester, For example, Acrylic ester, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, cyclohexyl acrylate, benzyl acrylate; Methacrylic; Methacrylic acid esters such as methyl acid, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, and benzyl methacrylate; These etc. are mentioned, These may use only 1 type and may use 2 or more types together. Among these, methyl methacrylate is preferable at the point which is excellent in heat resistance and transparency.

When using the said (meth) acrylic acid ester, the content rate in the monomer component provided to a superposition | polymerization process, In order to fully exhibit the effect of this invention, Preferably it is 10-100 weight%, More preferably, it is 10-100 It is 40% by weight, More preferably, it is 40-100 weight%, Especially preferably, it is 50-100 weight%.

Although it does not specifically limit as said hydroxyl-containing monomer, For example, 2- (hydroxyalkyl) acrylic acid ester, such as (alpha)-hydroxymethylstyrene, (alpha)-hydroxyethyl styrene, and 2- (hydroxyethyl) acrylate; 2- (hydroxyalkyl) acrylic acid, such as 2- (hydroxyethyl) acrylic acid; These etc. are mentioned, These may use 1 type and may use 2 or more types together.

When using the said hydroxyl group containing monomer, the content rate in the monomer component provided to a superposition | polymerization process, In order to fully exhibit the effect of this invention, Preferably it is 0-30 weight%, More preferably, it is 0-20 weight% More preferably, it is 0-15 weight%, Especially preferably, it is 0-10 weight%.

As said unsaturated carboxylic acid, acrylic acid, methacrylic acid, crotonic acid, (alpha)-substituted acrylic acid, (alpha) -substituted methacrylic acid, etc. are mentioned, for example, These may use only 1 type and uses 2 or more types together do. Among these, acrylic acid and methacrylic acid are preferable at the point which fully exhibits the effect of this invention.

When using the said unsaturated carboxylic acid, the content rate in the monomer component provided to a superposition | polymerization process, In order to fully exhibit the effect of this invention, Preferably it is 0-30 weight%, More preferably, it is 0-20 weight %, More preferably, it is 0-15 weight%, Especially preferably, it is 0-10 weight%.

As a monomer represented by the said General formula (201), styrene, vinyltoluene, (alpha) -methylstyrene, acrylonitrile, methyl vinyl ketone, ethylene, propylene, vinyl acetate etc. are mentioned, for example, Even if these use only 1 type, You may use 2 or more types together. Among these, styrene and (alpha) -methylstyrene are preferable at the point which fully exhibits the effect of this invention.

When using the monomer represented by the said General formula (201), the content rate in the monomer component provided to a superposition | polymerization process, In order to fully exhibit the effect of this invention, Preferably it is 0-30 weight%, More preferably, 0-20 weight%, More preferably, it is 0-15 weight%, Especially preferably, it is 0-10 weight%.

The monomer component may form a lactone ring after polymerization. In that case, it is preferable to polymerize the monomer component to obtain a polymer having a hydroxyl group and an ester group in the molecular chain.

As a form of the polymerization reaction for superposing | polymerizing the said monomer component and obtaining the polymer which has a hydroxyl group and ester group in a molecular chain, it is preferable that it is a polymerization form using a solvent, and solution polymerization is especially preferable.

For example, the lactones described in JP 2007-316366, JP 2005-189623, WO2007 / 032304 and WO2006 / 025445 are also preferable in which the cyclic structure described in the following publication is introduced. It is a ring structure.

(Lactone ring-containing polymer)

Although a lactone ring containing polymer will not be specifically limited if it has a lactone ring, Preferably it has a lactone ring structure represented by following General formula (401).

General formula (401) ：

In General Formula (401), R ⁴⁰¹ , R ⁴⁰² and R ⁴⁰³ Each independently represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms, and the organic residue may contain an oxygen atom. Here, as an organic residue of 1-20 carbon atoms, a methyl group, an ethyl group, isopropyl group, n-butyl group, t-butyl group, etc. are preferable.

The content rate of the lactone ring structure represented by the said General formula (401) in the structure of a lactone ring containing polymer becomes like this. Preferably it is 5-90 mass%, More preferably, it is 10-70 mass%, More preferably, it is 10- 60 mass%, Especially preferably, it is 10-50 mass%. The heat resistance of the obtained polymer and surface hardness tend to improve by making the content rate of a lactone ring structure 5 mass% or more, and the moldability of the obtained polymer improves by making the content rate of a lactone ring structure 90 mass% or less. Tends to be.

The method for producing the lactone ring-containing polymer is not particularly limited, but preferably, after the polymer (p) having a hydroxyl group and an ester group in the molecular chain is obtained by a polymerization step, the obtained polymer (p) is heat treated to perform lactone ring. It is obtained by performing the lactone cyclocondensation process which introduces a structure into a polymer.

The mass average molecular weight of the lactone ring-containing polymer is preferably 1,000 to 2,000,000, more preferably 5,000 to 1,000,000, still more preferably 10,000 to 500,000, and particularly preferably 50,000 to 500,000.

As for a lactone ring containing polymer, the mass reduction rate in the range of 150-300 degreeC in dynamic TG measurement becomes like this. Preferably it is 1% or less, More preferably, it is 0.5% or less, More preferably, it is 0.3% or less. About the measuring method of dynamic TG, the method of Unexamined-Japanese-Patent No. 2002-138106 can be used.

Since the lactone ring-containing polymer has a high cyclization condensation reaction rate, there is little dealcohol reaction in the manufacturing process of the molded article, and it is possible to avoid the drawback that bubbles or silver bath (silver streaks) enter the molded article after the alcohol. Can be. In addition, since the lactone ring structure is sufficiently introduced into the polymer by the high ring condensation reaction rate, the obtained lactone ring-containing polymer has high heat resistance.

When the lactone ring-containing polymer is a chloroform solution having a concentration of 15% by mass, the coloring degree (YI) is preferably 6 or less, more preferably 3 or less, still more preferably 2 or less, particularly preferably 1 or less. to be. When coloring degree (YI) is six or less, since the problem of transparency being impaired by coloring hardly arises, it can use preferably in this invention.

As for a lactone ring containing polymer, the 5% mass reduction temperature in thermal mass spectrometry (TG) becomes like this. Preferably it is 330 degreeC or more, More preferably, it is 350 degreeC or more, More preferably, it is 360 degreeC or more. 5% mass reduction temperature in thermal mass spectrometry (TG) is an index of thermal stability, and when it is set to 330 degreeC or more, there exists a tendency for sufficient thermal stability to be exhibited easily. The thermal mass spectrometry can use the said dynamic TG measuring apparatus.

As for a lactone ring containing polymer, glass transition temperature (Tg) becomes like this. Preferably it is 115 degreeC or more, More preferably, it is 125 degreeC or more, More preferably, it is 130 degreeC or more, Especially preferably, it is 135 degreeC or more, Most preferably 140 It is more than ℃.

The total amount of remaining volatile matter contained in the lactone ring-containing polymer is preferably 5,000 ppm or less, more preferably 2,000 ppm or less, still more preferably 1,500 ppm, particularly preferably 1,000 ppm. If the total amount of the remaining volatile matter is 5,000 ppm or less, molding defects such as coloration, foaming, or silver streak due to deterioration or the like during molding are less likely to occur.

As for a lactone ring containing polymer, the total light transmittance measured by the method based on ASTM-D-1003 with respect to the molded article obtained by injection molding becomes like this. Preferably it is 85% or more, More preferably, it is 88% or more, More preferably, 90% or more. Total light transmittance is an index of transparency, and when this is made into 85% or more, there exists a tendency for transparency to improve.

In the case of the polymerization form using a solvent, a polymerization solvent is not specifically limited, For example, aromatic hydrocarbon solvents, such as toluene, xylene, ethylbenzene; ketone solvents, such as methyl ethyl ketone and methyl isobutyl ketone; tetrahydro; Ether solvents, such as furan; These etc. are mentioned, Only 1 type of these may be used and 2 or more types may be used together.

Moreover, in the 1st aspect of the manufacturing method of this invention, since a (meth) acrylic-type resin is melt | dissolved in an organic solvent and solution casting is formed, the organic solvent at the time of the synthesis | combination of (meth) acrylic-type resin is melt film forming It does not restrict | limit rather than carrying out, and may synthesize | combine using the high organic solvent of boiling point.

In the case of a polymerization reaction, you may add a polymerization initiator as needed. Although it does not specifically limit as a polymerization initiator, For example, cumene hydroperoxide, diisopropyl benzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butylperoxy isopropyl carbonate , organic peroxides such as t-amylperoxy-2-ethylhexanoate; 2,2'-azobis (isobutyronitrile), 1,1'-azobis (cyclohexanecarbonitrile), 2,2 ' Azo compounds, such as-azobis (2, 4- dimethylvaleronitrile); These etc. are mentioned, These may use 1 type and may use 2 or more types together. What is necessary is just to set the usage-amount of a polymerization initiator suitably according to the combination of monomers used, reaction conditions, etc., and it is not specifically limited.

The weight average molecular weight of a polymer can be adjusted by adjustment of the quantity of a polymerization initiator.

When superposing | polymerizing, in order to suppress gelation of a reaction liquid, it is preferable to control so that the density | concentration of the produced polymer in a polymerization reaction mixture may be 50 weight% or less. Specifically, when the concentration of the produced polymer in the polymerization reaction mixture exceeds 50% by weight, it is preferable to add the polymerization solvent to the polymerization reaction mixture as appropriate to control it to be 50% by weight or less. The concentration of the resulting polymer in the polymerization reaction mixture is more preferably 45% by weight or less, still more preferably 40% by weight or less.

It does not specifically limit as an aspect which adds a polymerization solvent suitably to a polymerization reaction mixture, A polymerization solvent may be added continuously and a polymerization solvent may be added intermittently. By controlling the concentration of the polymer produced in the polymerization reaction mixture in this way, the gelation of the reaction solution can be more sufficiently suppressed. As a polymerization solvent to add, although the solvent of the same kind as the solvent used at the time of the initial injection of a polymerization reaction may be sufficient, and a different kind of solvent may be sufficient, it is preferable to use the same kind of solvent as the solvent used at the time of initial injection of a polymerization reaction. . Moreover, 1 type of solvents may be sufficient as the polymerization solvent to add, and 2 or more types of mixed solvents may be sufficient as it.

As the acrylic resin and the derivative of (meth) acrylic acid which can be used in the present invention, and other copolymerizable monomers, JP-A-2009-122664, JP-A-2009-139661, JP-A-2009-139754, JP-A What is described in each publication, such as patent publication 2009-294262, international publication 2009/054376, can also be used. In addition, these do not limit this invention, These can be used individually or in combination of 2 or more types.

When two or more types of acrylic resins are used, it is preferable to use at least one acrylic resin having the above structure.

The mass average molecular weight Mw of the acrylic resin used in the present invention is preferably 80000 or more. When the mass average molecular weight Mw of the acrylic resin is 80000 or more, the mechanical strength is high and the handling suitability at the time of film production is excellent. From this viewpoint, the mass average molecular weight Mw of the acrylic resin is preferably 100000 or more. Moreover, from a viewpoint of the compatibility improvement with a cellulose ester, it is preferable that the mass mean molecular weight Mw of an acrylic resin is 3 million or less, and it is more preferable that it is 2 million or less.

As an acrylic resin used for this invention, a commercially available thing can be used. For example, Delpet 60N and 80N (manufactured by Asahi Chemical Industry Co., Ltd.), Dianal BR80, BR85, BR88 and BR102 (manufactured by Mitsubishi Rayon) and KT75 (manufactured by Denki Kagaku Kogyo) .

Two or more acrylic resins may be used in combination.

(Polyester Resin)

As polyester resin, polyethylene terephthalate and polyethylene naphthalate are preferable. In order to control peeling force and toughness suitably, you may add and use an additive.

(Polycarbonate Resin)

The thermoplastic resin which can be used for the present invention can be used by adding an additive to the polycarbonate resin in order to appropriately control the peel force and the toughness. As a polycarbonate film, as a commercial item, pure ace, pure ace WR (made by Teijin Chemical Co., Ltd.), Elmek (made by Kaneka Corporation) is mentioned.

(Polystyrene-based resin)

The thermoplastic resin which can be used for the present invention can be used by adding an additive to the polystyrene resin in order to appropriately control the peel force and the toughness.

(Cyclic polyolefin resin)

As the thermoplastic resin usable in the present invention, a cyclic polyolefin-based resin can be used. Here, cyclic polyolefin type resin shows the polymer resin which has a cyclic olefin structure.

Examples of the polymer resin having a cyclic olefin structure for use in the present invention include (1) a norbornene-based polymer, (2) a polymer of a cyclic olefin of a single ring, (3) a polymer of a cyclic conjugated diene, and (4) vinyl Alicyclic hydrocarbon polymer, and the hydride of (1)-(4).

Preferred polymers for the present invention include at least one additional (co) polymer cyclic polyolefin-based resin containing at least one or more repeating units represented by the following General Formula (IIX) and, if necessary, the repeating units represented by General Formula (IX). It is an addition (co) polymer cyclic polyolefin type resin which further contains a species or more. Moreover, the ring-opening (co) polymer containing at least 1 sort (s) of the cyclic repeating unit represented by general formula (IIIX) can also be used preferably.

General formula (IX)

General formula (IIX)

General formula (IIIX)

M shows the integer of 0-4 in a formula (IX)-(IIIX). R ¹ to R ⁶ Is a hydrocarbon group a hydrogen atom or a carbon number of ^{1 ~ 10, X 1 ~ X} 3, Y 1 ~ Y 3 A hydrogen atom, a hydrocarbon group of 1 to 10 carbon atoms, a halogen atom, a hydrocarbon group of 1 to 10 carbon atoms substituted with a halogen atom,-(CH ₂ ) _n COOR ¹¹ ,-(CH ₂ ) _n OCOR ¹² ,-(CH ₂ ) _n NCO,-(CH ₂ ) _n NO ₂ ,-(CH ₂ ) _n CN,-(CH ₂ ) _n CONR ¹³ R ¹⁴ ,-(CH ₂ ) _n NR ¹³ R ¹⁴ ,-(CH ₂ ) _n OZ, -(CH ₂ ) _n W, or X ¹ And Y ¹ or X ² And Y ² or (-CO) ₂ O consisting of X ³ and Y ³ , (-CO) ₂ NR ¹⁵ . In addition, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ Is a hydrogen atom, a hydrocarbon group of 1 to 20 carbon atoms, Z is a hydrocarbon group substituted by a hydrocarbon group or halogen, W is SiR ¹⁶ _p D _{3 -p} (R ¹⁶ D is a halogen atom, -OCOR ¹⁶ or -OR ^16, a hydrocarbon group, having a carbon number of 1 ~ 10 p represents an integer of 0 to 3), n represents an integer of 0 to 10.

Norbornene-based polymer hydrides are disclosed in Japanese Patent Application Laid-Open No. Hei 1-240517, Japanese Patent Laid-Open No. 7-196736, Japanese Patent Laid-Open No. 60-26024, Japanese Patent Laid-Open No. 62-19801, and Japanese Laid-Open Patent Publication. As disclosed in Japanese Patent Laid-Open Publication No. 2003-1159767 or Japanese Laid-Open Patent Publication No. 2004-309979 and the like, the polycyclic unsaturated compound is added by hydrogenation after addition polymerization or metathesis ring-opening polymerization. In the norbornene-based polymer used in the present invention, R ⁵ to R ⁶ Silver hydrogen atom or -CH ₃ Are preferred, X ³ , and Y ³ Silver hydrogen atom, Cl, -COOCH ₃ This is preferable and other groups are suitably selected. This norbornene-based resin is released under the trade name of Aton G or Aton F from JSR, and Zeonor ZF14, ZF16, Zeonex 250 from Nippon Xeon Or it is marketed under the brand name of Xeonex 280, These can be used.

Norbornene-based addition (co) polymers are disclosed in JP-A-10-7732, JP-A-2002-504184, JP-A-2004229157 A1, WO2004 / 070463 A1, and the like. It is obtained by addition-polymerizing norbornene-type polycyclic unsaturated compounds. Further, if necessary, norbornene-based polycyclic unsaturated compounds, conjugated dienes such as ethylene, propylene, butene; butadiene and isoprene; nonconjugated dienes such as ethylidene norbornene; acrylonitrile, acrylic acid, methacrylic acid, anhydrous You may add-polymerize linear diene compounds, such as maleic acid, an acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate, a vinyl chloride. This norbornene-based addition (co) polymer is available from Mitsui Chemicals Co., Ltd. under the trade name of Apel, and has a different glass transition temperature (Tg), for example, APL8008T (Tg 70 ° C), APL6013T (Tg 125 ° C) or Grades such as APL6015T (Tg 145 ° C.). Pellets such as TOPAS8007, copper 6013, and copper 6015 are available from Polyplastics. In addition, the Appear 3000 is released from Ferrania.

In this invention, although there is no restriction | limiting in the glass transition temperature (Tg) of cyclic polyolefin type resin, High Tg cyclic polyolefin resin of 200-400 degreeC can also be used, for example.

(Glutaric anhydride resin)

The glutaric anhydride type resin can be used for the thermoplastic resin which can be used for this invention. Here, glutaric anhydride type resin shows the polymer resin which has a glutaric anhydride unit.

It is preferable that the polymer which has a glutaric anhydride unit has a glutaric anhydride unit (henceforth a glutaric anhydride unit) represented by following General formula (402).

General formula (402) ：

In General Formula (402), R ³¹ and R ³² Each independently represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms. In addition, the organic residue may contain an oxygen atom. R ³¹ , R ³² Especially preferably, they represent the same or different hydrogen atom or a C1-C5 alkyl group.

It is preferable that the polymer which has a glutaric anhydride unit is an acrylic copolymer containing a glutaric anhydride unit. As an acryl-type thermoplastic copolymer, what has a glass transition temperature (Tg) of 120 degreeC or more from a heat resistant point is preferable.

As content of the glutaric anhydride unit with respect to an acryl-type thermoplastic copolymer, 5-50 mass% is preferable, More preferably, it is 10-45 mass%. By setting it as 5 mass% or more, More preferably, it is 10 mass% or more, the effect of heat resistance improvement can be acquired, and also the effect of a weather resistance improvement can also be obtained.

Moreover, it is preferable that said acrylic thermoplastic copolymer contains the repeating unit further based on an unsaturated carboxylic acid alkyl ester. As a repeating unit based on unsaturated carboxylic acid alkyl ester, it is preferable to represent with the following general formula (403), for example.

General formula (403):-[CH ₂ -C (R ⁴¹ ) (COOR ⁴² )]-

In General Formula (403), R ⁴¹ represents hydrogen or an alkyl group having 1 to 5 carbon atoms, and R ⁴² is substituted with an aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms, or a hydroxyl group or halogen having 1 or more carbon atoms or less. An aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms is shown.

The monomer corresponding to the repeating unit represented by General formula (403) is represented by following General formula (404).

General formula (404): CH ₂ = C (R ⁴¹ ) (COOR ⁴² )

As a preferable specific example of such a monomer, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, and n- (meth) acrylate Hexyl, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) acrylic acid 2 And 3,4,5,6-pentahydroxyhexyl and 2,3,4,5-tetrahydroxypentyl (meth) acrylic acid. Among these, methyl methacrylate is most preferably used. These may be used individually by 1 type, or may use 2 or more types together.

As for content of the unsaturated carboxylic acid alkyl ester unit with respect to said acrylic thermoplastic copolymer, 50-95 mass% is preferable, More preferably, it is 55-90 mass%. The acrylic thermoplastic copolymer having a glutaric anhydride unit and an unsaturated carboxylic acid alkyl ester type unit is obtained by polymerizing a copolymer having an unsaturated carboxylic acid alkyl ester type unit and an unsaturated carboxylic acid unit, for example. Can be.

As an unsaturated carboxylic acid unit, what is represented, for example by the following general formula (405) is preferable.

General formula _{(405): - [CH 2} -C (R 51) (COOH)] -

R ⁵¹ represents hydrogen or an alkyl group having 1 to 5 carbon atoms.

As a preferable specific example of the monomer which guide | induces an unsaturated carboxylic acid unit, the compound represented by the following general formula (406) which is a monomer corresponding to the repeating unit represented by General formula (405), maleic acid, and also the valence of maleic anhydride Although a degradation product etc. are mentioned, Acrylic acid and methacrylic acid are preferable at the point which is excellent in thermal stability, More preferably, it is methacrylic acid.

General formula (406): CH ₂ = C (R ⁵¹ ) (COOH)

These may be used individually by 1 type, or may use 2 or more types together. As mentioned above, the acryl-type thermoplastic copolymer which has a glutaric anhydride unit and an unsaturated carboxylic acid alkyl ester type unit, For example, copolymerizes the copolymer which has an unsaturated carboxylic acid alkyl ester type unit and an unsaturated carboxylic acid unit. Since it can be obtained by oxidizing, you may leave unsaturated carboxylic acid unit in the structural unit.

As content of the unsaturated carboxylic acid unit with respect to said acrylic thermoplastic copolymer, 10 mass% or less is preferable, More preferably, it is 5 mass% or less. By setting it as 10 mass% or less, fall of colorless transparency and retention stability can be prevented.

Moreover, the said acrylic thermoplastic copolymer may have the other vinylic monomer unit which does not contain an aromatic ring in the range which does not impair the effect of this invention. As a specific example of the other vinylic monomer unit which does not contain an aromatic ring, when it mentions corresponding monomer, vinyl cyanide monomers, such as an acrylonitrile, methacrylonitrile, an ethacrylonitrile; allyl glycidyl ether; maleic anhydride Acid, itaconic anhydride; N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, acrylamide, methacrylamide, N-methylacrylamide, butoxymethylacrylamide, N-propylmethacrylamide Aminoethyl acrylate, propylaminoethyl acrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, cyclohexylaminoethyl methacrylate; N-vinyldiethylamine, N-acetylvinylamine, allylamine, methalyl Amine, N-methylallylamine; 2-isopropenyl-oxazoline, 2-vinyl-oxazoline, 2-acroyl-oxazoline and the like. These may be used individually by 1 type and may use 2 or more types together.

As content of the other vinylic monomer unit which does not contain an aromatic ring with respect to said acrylic thermoplastic copolymer, 35 mass% or less is preferable.

In addition, about the vinyl-type monomeric unit (N-phenylmaleimide, phenyl amino ethyl methacrylate, p-glycidyl styrene, p-amino styrene, 2-styryl- oxazoline etc.) containing an aromatic ring, Since there exists a tendency for a fall in weatherability and weather resistance, it is preferable that it is only 1 mass% or less as content with respect to said acrylic thermoplastic copolymer.

(Glutarimide resin)

As a thermoplastic resin which can be used for this invention, glutarimide-type resin can be used. Here, glutarimide-type resin represents the polymer resin which has a glutarimide unit.

The glutarimide-based resin is a thermoplastic resin having a substituted or unsubstituted imide group in the side chain. By having a substituted or unsubstituted imide group in a side chain, the characteristic balance can be expressed from an optical characteristic, heat resistance, etc. point. The above (glutarimide-based resin is at least the following general formula (501):

General Formula (501)

Glutarimide units represented by the formula (wherein, R ³⁰¹ , R ³⁰² , R ³⁰³ Is independently hydrogen or an unsubstituted or substituted alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group). It is preferable to contain a glutarimide resin having 20% by weight or more.

As a preferable glutimide unit which comprises the glutarimide resin used for this invention, R ³⁰¹ and R ³⁰² Is hydrogen or a methyl group, R ³⁰³ This is a methyl group or a cyclohexyl group. A single kind may be sufficient as the glutarimide unit, and R ³⁰¹ , R ³⁰² , R ³⁰³ You may contain these different several types.

As a preferable 2nd structural unit which comprises glutarimide-type resin used for this invention, it is a unit which consists of acrylic acid ester or methacrylic acid ester. Preferable acrylic acid ester or methacrylic acid ester structural units include methyl acrylate, ethyl acrylate, methyl methacrylate, methyl methacrylate and the like. Moreover, N-alkyl methacrylamide, such as N-methylmethacrylamide and N-ethyl methacrylamide, is mentioned as another preferable imidation unit. These 2nd structural units may be individual types, and they may contain several types.

Content of the glutarimide unit represented by General formula (501) of glutarimide-type resin is 20 weight% or more based on the total repeating unit of glutarimide-type resin. Preferable content of a glutarimide unit is 20 to 95 weight%, More preferably, it is 50 to 90 weight%, More preferably, it is 60 to 80 weight%. When a glutarimide unit is smaller than this range, the heat resistance of the film obtained may be inadequate or transparency may be impaired. Moreover, when this range is exceeded, heat resistance will rise unnecessarily and it will become difficult to form a film, the mechanical strength of the film obtained will become extremely weak, and transparency may be impaired.

As needed, a third structural unit may be copolymerized with glutarimide-type resin. As an example of a preferable 3rd structural unit, Styrene-type monomers, such as styrene, substituted styrene, (alpha) -methylstyrene, acrylic monomers, such as butylacrylate, nitrile-type monomers, such as acrylonitrile and methacrylonitrile, maleimide, N- Structural units formed by copolymerizing maleimide monomers such as methyl maleimide, N-phenylmaleimide, and N-cyclohexyl maleimide can be used. These may be directly copolymerized with the glutarimide unit and the imidable unit in glutarimide-type resin, and may be graft-copolymerized with respect to the resin which has the glutimide unit and the imidable unit. When a 3rd component adds this, it is preferable that content rate in glutarimide-type resin is 5 mol% or more and 30 mol% or less based on the total repeating unit in glutarimide-type resin.

Glutarimide-based resins are described in U.S. Patent No. 3284425, U.S. Patent No. 4246374, JP-A 2-153904, etc., and resins obtained by using methacrylic acid methyl ester or the like as a main raw material as a resin having an imidizable unit. Can be obtained by imidating the resin having the imidable unit using ammonia or substituted amine. When obtaining glutarimide-type resin, the unit comprised from acrylic acid, methacrylic acid, or its anhydride may be introduce | transduced in glutarimide-type resin as a reaction by-product. Since the presence of such a structural unit, especially an acid anhydride, reduces the total light transmittance and haze of the film of this invention obtained, it is not preferable. As acrylic acid or methacrylic acid content, it is preferable to set it as 0.5 milliequivalents or less per 1 g of resin, Preferably it is 0.3 milliliters or less, More preferably, it is 0.1 milliliters or less. Moreover, as shown in Unexamined-Japanese-Patent No. 02-153904, it is also possible to obtain glutarimide-type resin by imidizing using resin mainly consisting of N-methyl acrylamide and methacrylic acid methyl ester.

Moreover, it is preferable that glutarimide resin has a weight average molecular weight of 1 * 10 <^4> -5 * 10 <^5> .

&Lt; Film having low moisture permeability layer &gt;

The film which provided the low moisture vapor transmission layer on the 2nd polarizing plate protective film and lowered the water vapor transmission rate can also be used. If the film having a low moisture vapor transmission layer satisfies the water vapor transmission rate of 100 g / m 2 · 24 hr or less, the low moisture vapor transmission layer may be formed of any material. However, the low moisture vapor transmission layer may have a cyclic aliphatic hydrocarbon group and unsaturated double bond in its molecule. It is preferable that it is a layer formed from the composition containing a compound, or the layer which has a resin containing a repeating unit derived from a chlorine-containing vinyl monomer, and is a composition containing the compound which has a cyclic aliphatic hydrocarbon group and unsaturated double bond in a molecule | numerator. It is more preferable that it is a layer formed with the.

(Composition of low moisture vapor barrier)

The low moisture-permeable layer which can be used for a 2nd polarizing plate protective film contains the layer formed from the composition containing the compound which has a cyclic aliphatic hydrocarbon group and unsaturated double bond in a molecule | numerator, or contains the repeating unit derived from a chlorine-containing vinyl monomer. It is preferable that it is a layer which has resin to make, and it is more preferable that it is a layer formed from the composition containing the compound which has a cyclic aliphatic hydrocarbon group and unsaturated double bond in a molecule | numerator.

The layer formed from the composition which has a compound which has a compound which has a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in the said molecule as a main component is demonstrated.

<< layer formed from the composition which has a compound which has a cyclic aliphatic hydrocarbon group and unsaturated double bond group in a molecule as a main component >>

In the present invention, the layer formed of a composition containing a compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in a molecule as a main component has a cyclic aliphatic hydrocarbon group and also has an unsaturated double bond group in the molecule in order to impart low moisture permeability. It is possible to form a composition containing a compound having, and further comprising a polymerization initiator, a light-transmitting particle, a fluorine-containing or silicone-based compound, a solvent, by applying, drying, and curing on a support directly or through another layer. have. Each component is demonstrated below. In addition, the main component of a composition or a layer means the component which occupies 50 mass% or more of this composition or the layer.

[Compound having cyclic aliphatic hydrocarbon group and unsaturated double bond group in molecule]

Compounds having a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in the molecule function as a binder. Moreover, the compound which has a cyclic aliphatic hydrocarbon group, and has an unsaturated double bond group can function as a hardening | curing agent, can improve the strength and scratch resistance of a coating film, and can provide low moisture permeability.

By using such a compound, low moisture permeability and high film strength can be realized. Although it is not clear in detail, by using the compound which has a cyclic aliphatic hydrocarbon group in a molecule | numerator, a hydrophobic cyclic aliphatic hydrocarbon group is introduce | transduced into a low moisture-permeable layer, and hydrophobization prevents acceptance of a molecule | numerator from the exterior and reduces moisture permeability. Moreover, by having an unsaturated double bond group in a molecule | numerator, a crosslinking point density is raised and the diffusion path of the water | moisture content in a low moisture-permeable layer is restrict | limited. Increasing the crosslinking point density also has the effect of relatively increasing the density of the cyclic aliphatic hydrocarbon group, making the lower moisture permeable layer more hydrophobic, preventing the adsorption of water molecules, and lowering the moisture permeability.

In order to raise a crosslinking point density, it is more preferable that the number of the unsaturated double bond groups which have in a molecule | numerator is two or more.

The cyclic aliphatic hydrocarbon group is preferably a group derived from an alicyclic compound having 7 or more carbon atoms, more preferably a group derived from an alicyclic compound having 10 or more carbon atoms, and even more preferably derived from an alicyclic compound having 12 or more carbon atoms. It is a group.

The cyclic aliphatic hydrocarbon group is particularly preferably a group derived from a polycyclic compound such as bicyclic or tricyclic.

More preferably, the central skeleton of the compound described in JP 2006-215096 A, the central skeleton of the compound described in JP 2001-10999 A, or the skeleton of an adamantane derivative, etc. Can be mentioned.

As the cyclic aliphatic hydrocarbon group (including a linking group), a group represented by any of the following general formulas (IY) to (VY) is preferable, and a group represented by the following general formulas (IY), (IIY), or (IVY) is more preferable. And group represented by the following general formula (IY) is more preferable.

General formula (IY)

In general formula (IY), L and L 'respectively independently represent a bivalent or more coupling group. n represents the integer of 1-3.)

General formula (IIY)

In general formula (IIY), L and L 'respectively independently represent a bivalent or more coupling group. and n represents an integer of 1 to 2.

General formula (IIIY)

In general formula (IIIY), L and L 'respectively independently represent a bivalent or more coupling group. and n represents an integer of 1 to 2.

General formula (IVY)

In General Formula (IVY), L and L 'respectively independently represent a bivalent or more coupling group, and L' 'represents a hydrogen atom or a bivalent or more coupling group.

General formula (VY)

In General Formula (V), L and L 'respectively independently represent a bivalent or more coupling group.

Specific examples of the cyclic aliphatic hydrocarbon group include norbornyl, tricyclodecanyl, tetracyclododecanyl, pentacyclopentadecanyl, adamantyl, diamantanyl, and the like.

As the unsaturated double coupler, (meth) there may be mentioned a polymerizable functional group such as a group, vinyl group, styryl group, allyl group, acryloyl, among others, (meth) acryloyl group and a -C (O) OCH = CH ₂ is desirable. Especially preferably, the compound containing three or more (meth) acryloyl groups in the following molecule | numerator can be used.

The compound which has a cyclic aliphatic hydrocarbon group and has 3 or more unsaturated double bond groups in a molecule | numerator is comprised by the said cyclic aliphatic hydrocarbon group and group which has an unsaturated double bond couple | bonding through the coupling group.

Examples of the linking group include a single bond, an alkylene group which may be substituted with 1 to 6 carbon atoms, an amide group which may be substituted for the N position, a carbamoyl group that may be substituted for the N position, an ester group, an oxycarbonyl group, an ether group, and the like. The group obtained by combining these is mentioned.

These compounds are the carboxylic acid, carboxyl of the polyol, such as diol and triol which have the said cyclic aliphatic hydrocarbon group, and the compound which has a (meth) acryloyl group, a vinyl group, a styryl group, an allyl group, etc., for example. It can be easily synthesized by one-step or two-step reaction with an acid derivative, an epoxy derivative, an isocyanate derivative and the like.

Preferably, compounds, such as (meth) acrylic acid, (meth) acryloyl chloride, (meth) acrylic anhydride, (meth) acrylic acid glycidyl, and the compound of WO2012 / 00316A (for example, 1,1- It can synthesize | combine by making it react with the polyol which has the said cyclic aliphatic hydrocarbon group using bis (acryloxymethyl) ethyl isocyanate).

Although the preferable specific example of a compound which has a cyclic aliphatic hydrocarbon group and an unsaturated double bond group is shown below, this invention is not limited to these.

[Polymerization initiator]

Although it is preferable to contain a polymerization initiator in the composition which has a compound which has a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in a molecule as a main component, a photoinitiator is preferable as a polymerization initiator.

As a photoinitiator, acetophenones, benzoin, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disul Fused compounds, fluoroamine compounds, aromatic sulfoniums, ropindimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, coumarins and the like. Specific examples of the photopolymerization initiator, preferred embodiments, commercial products, and the like are described in paragraphs [0133] to [0151] of JP2009-098658A and can be preferably used in the present invention as well.

`` Latest UV Curing Technology '' ｛Technical Information Association｝ (1991), p. 159, and "ultraviolet ray hardening system" Katomi Kiyoshi writing (the first year of peace, synthesis technical center issuance), p. Various examples are also described in 65-148 and are useful for this invention.

As a commercially available photo cleavage type radical photopolymerization initiator, "Irgacure 651", "Irgacure 184", "Irgacure 819" and "Irgacure 907" by Chiba Specialty Chemicals Co., Ltd. make , "Irgacure 1870" (CGI-403 / Irgacure 184 = 7/3 mixed initiator), "Irgacure 500", "Irgacure 369", "Irgacure 1173", "Irgacure 2959" , "Irugacure 4265", "Irugacure 4263", "Irugacure 127", "OXE01", etc .; "Gayacure-DETX-S" of Nippon Gunpowder Co., Ltd., "Gayacure-BP-" 100, Gayacure-BDMK, Gayacure-CTX, Gayacure-BMS, Gayacure-2-EAQ, Gayacure-ABQ, Gayacure-CPTX, Gayacure -EPD, Gayacure-ITX, Gayacure-QTX, Gayacure-BTC, Gayacure-MCA, and others; Esacure (KIP100F, KB1, EB3, BP, X33, KTO46, KT37, KIP150, TZT) ”, and combinations thereof Preferred examples can be given.

Content of the photoinitiator in the composition which has a compound which has a cyclic aliphatic hydrocarbon group and an unsaturated double bond group as a main component in the molecule | numerator used for this invention superposes | polymerizes the polymerizable compound contained in the said composition, and also the starting point does not increase too much For the reason for setting, 0.5-8 mass% is preferable with respect to the total solid in the composition for hard-coat layer formation, and 1-5 mass% is more preferable.

〔solvent〕

The composition which has a compound which has a cyclic aliphatic hydrocarbon group and unsaturated double bond group in the molecule used for this invention as a main component can contain a solvent. As the solvent, various solvents can be used in consideration of the solubility of the monomer, the drying property at the time of coating, the dispersibility of the light transmitting particles, and the like. As such an organic solvent, for example, dibutyl ether, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran , Anisole, phentol, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, acetone, methyl ethyl ketone (MEK), diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclo Hexanone, ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, methyl 2-methoxyacetate, 2-ethoxyacetate, 2-e Ethyl oxyacetate, 2-ethoxypropionate, 2-methoxyethanol, 2-propoxyethanol, 2-butoxyethanol, 1,2-diacetoxyacetone, acetylacetone, diacetone alcohol, methyl acetoacetate, aceto Methyl alcohol, ethyl alcohol, such as ethyl acetate , Isopropyl alcohol, n-butyl alcohol, cyclohexyl alcohol, isobutyl acetate, methyl isobutyl ketone (MIBK), 2-octanone, 2-pentanone, 2-hexanone, ethylene glycol ethyl ether, ethylene glycol isopropyl Ether, ethylene glycol butyl ether, propylene glycol methyl ether, ethyl carbitol, butyl carbitol, hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, benzene, toluene, xylene, and the like. It can be used individually by 1 type or in combination of 2 or more types.

When the said base film is a cellulose acylate film, it is preferable to use at least 1 sort (s) of dimethyl carbonate, methyl acetate, ethyl acetate, methyl ethyl ketone, acetyl acetone, and acetone, and either dimethyl carbonate or methyl acetate is more preferable. And methyl acetate is especially preferable.

It is preferable to use a solvent so that the concentration of the solid content of the composition mainly containing a compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in the molecule used may be in the range of 20 to 80 mass%, more preferably 30 It is-75 mass%, More preferably, it is 40-70 mass%.

In addition, about the layer which has resin containing the repeating unit derived from the said chlorine-containing vinyl monomer, the coating layer as described in [0042]-[0058] of Unexamined-Japanese-Patent No. 2008-230036 can be used preferably. As a component for forming the layer which consists of a composition containing vinylidene chloride as a main component, Asahi Chemical Life & Living Co., Ltd. among the materials of the coating layer as described in [0042]-[0058] of Unexamined-Japanese-Patent No. 2008-230036. It is preferable to use manufacture "saran resin R204".

In addition, the main component of a composition or a layer means the component which occupies 50 mass% or more of this composition or the layer.

(Configuration and Manufacturing Method of Low Water Vapor Layer)

The low moisture permeable layer may be a single layer or a plurality of layers. Although the lamination | stacking method of the said low moisture-permeable layer is not specifically limited, It is preferable to form the said low-moisture-permeable layer as a covalent bond with a base film, or to laminate | stack and form the said low-moisture layer by application | coating on the said base film, It is more preferable to laminate | stack and form the said low moisture-permeable layer by apply | coating on the said base film. That is, as for a 2nd polarizing plate protective film, it is more preferable that the said low moisture-permeable layer is laminated | stacked on the said base film by application | coating.

(Film thickness of low moisture vapor barrier)

It is preferable that the film thickness of the said low moisture-permeable layer is 1-20 micrometers, It is more preferable that it is 2-18 micrometers, It is especially preferable that it is 3-17 micrometers.

It is also preferable that the low moisture-permeable layer of a 2nd polarizing plate protective film has moisture permeability hard coat layer function, antireflection function, antifouling function, etc. together.

<Liquid Crystal Display Device>

The liquid crystal display device of this invention contains at least 1 polarizing plate of this invention, and is arrange | positioned so that a 1st polarizing plate protective film may become a liquid crystal cell side. The liquid crystal display device of this invention includes the polarizing plate of this invention containing the cellulose acylate film of this invention, and the contrast of the front direction and the color taste change of the viewing angle direction are remarkably improved.

In the liquid crystal display device of the present invention, the thickness of the glass constituting the liquid crystal cell is preferably 50 to 500 mu m. By using such glass, it becomes possible to make thickness of a liquid crystal display device thin.

The liquid crystal display device of the present invention is a liquid crystal display device having a liquid crystal cell and a pair of polarizing plates disposed on both sides of the liquid crystal cell, wherein at least one of the polarizing plates is the polarizing plate of the present invention, wherein the polarizer is an IPS, OCB or VA mode. It is preferable that it is a liquid crystal display device of.

There is no restriction | limiting in particular as a specific structure of the liquid crystal display device of this invention, A well-known structure can be employ | adopted, For example, the example made into the structure of FIG. 1 can be employ | adopted. The configuration described in FIG. 2 of Japanese Laid-Open Patent Publication No. 2008-262161 is also preferably employed.

Example

Hereinafter, the present invention will be described in more detail with reference to examples. Materials, reagents, amounts of substances, proportions thereof, operations, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.

(Preparation of cellulose acylate)

The kind of acyl group and substitution degree of the acyl group shown in the following table | surface were prepared. This added sulfuric acid (7.8 mass parts with respect to 100 mass parts of cellulose) as a catalyst, added the carboxylic acid used as a raw material of an acyl substituent, and performed the acylation reaction at 40 degreeC. At this time, the type and degree of substitution of the acyl group were adjusted by adjusting the kind and amount of the carboxylic acid. Moreover, aging was performed at 40 degreeC after acylation. Furthermore, the low molecular weight component of this cellulose acylate was wash | cleaned and removed by acetone.

[Examples and Comparative Examples]

<Film forming of a cellulose acylate film>

Using the cellulose acylate dope shown below, the film was formed into a film by the solution casting method, and it used for each Example and the comparative example.

(Cellulose acylate dope A)

-------------------------------------------------- ------------

Cellulose acylate resin: 100 parts by mass of the substituent shown in the following table and the degree of substitution

Additive: The thing described in the following table The quantity (unit: mass%) described in the following table

406 parts by mass of dichloromethane

61 parts by mass of methanol

-------------------------------------------------- ------------

Polycondensation ester was synthesize | combined according to description of Unexamined-Japanese-Patent No. 05-155809. That is, the terminal was sealed with the group shown in the following table using the dicarboxylic acid and diol shown in the following table. The sugar ester was synthesize | combined according to description of WO2011 / 016279 and Unexamined-Japanese-Patent No. 2012-31313.

The structure of a discotic compound is described below.

The cellulose acylate dope A is mixed with a dispersion of a mat agent such that 0.13 parts by mass of a mat agent (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd., secondary average particle size 1.0 μm or less), which is a fine particle, per 100 parts by mass of cellulose acylate, Stirred.

(Solution softness in monolayer)

The dope of the said composition was thrown into the mixing tank, and it stirred, and melt | dissolved each component, and filtered with the filter paper of 34 micrometers of average hole diameters, and the sintered metal filter of 10 micrometers of average hole diameters, and prepared the cellulose acylate dope. The dope was flexible with a band softener. In addition, the band was manufactured from SUS. The amount of residual solvent peeled off from a band in the state which was 10-30 mass% more than the amount of residual solvent before extending | stretching.

The film peeled off from the band was dried in the tenter apparatus using a tenter apparatus which clips and conveys both ends of a web with a clip. Under the present circumstances, the film peeled off from the band separate from the film provided for the following extending processes is completely dried in an unstretched state, and it is set as the cellulose acylate film for Tg measurement samples, and the glass transition temperature of this film is described in this specification. It measured by the method and described as film Tg in the following table | surface.

On the other hand, drying time and temperature are adjusted so that the amount of residual solvent at the time of extending | stretching start may be a value shown in the following table with respect to the film after the said drying, and the ambient temperature of the constant temperature zone in which the tenter in extending | stretching is provided is each film by a tenter. Stretching was performed in the transverse direction (direction perpendicular to the conveying direction) at the stretching ratio shown in the following table while hitting hot air so as to be the temperature shown in the table with respect to Tg in the dry film. In addition, the film after extending | stretching confirmed that the solvent remained.

Then, the film shifted from tenter conveyance to roll conveyance, dried at 120 degreeC again, and wound up. The film thickness at this time is described in the following table.

[evaluation]

(Measurement of Retardation Value)

Humidity was adjusted at 25 degreeC and 60% of a relative humidity for 2 hours or more, and the produced cellulose acylate film was made into a wavelength at 25 degreeC and 60% of a relative humidity using birefringence measuring apparatus (KOBRA 21ADH, Oji Meter Co., Ltd. product). The Re value and Rth value at 590 nm were measured and shown in the following table. Moreover, the value of Rth (nm) / film thickness (micrometer) was calculated, and it showed in the table together. The film thickness d was made into the average film thickness.

(Water contact test)

The produced film was cut out to 4 cm in width and height, and the humidity was adjusted for 1 hour in an environment of 25 ° C. 60% relative humidity, and then bonded to a glass of 5 cm in width and pressure using an adhesive. In this state, Re and Rth of the film of an initial state were measured using KOBRA 21ADH (made by Oji Measurement Instruments Co., Ltd.). 500 microliters of pure water was dripped on the measured film using a micropipette, the film was quickly covered with Saran Lab (made by Asahi Kasei Co., Ltd.), and the surroundings were made of Kapton tape (Nitto Electric Co., Ltd.). It was affixed and sealed it. The sample was placed in a thermostat controlled at 35 ° C. for 12 hours, then taken out, and the saran wrap was removed to wipe off water attached to the film surface. Then, after adjusting humidity for 2 hours in the environment of 25 degreeC 60% relative humidity, Re and Rth were measured. The absolute value of the difference of Re and Rth before and behind a process was made into the optical change at the time of a water treatment test.

(Internal haze)

The measurement of the internal haze was carried out by dropping a few drops of glycerin onto both sides of a 40 mm x 80 mm cellulose acylate film sample of the present invention, and from two sides with two glass plates of 1.3 mm thickness (manufactured by MICRO SLIDE GLASS part number S9213, manufactured by MATSUNAMI). Glycerin was placed between two glasses at a temperature of 25 ° C. and 60% relative humidity from a haze value measured by a haze meter “HGM-2DP” using a tester manufactured by Co., Ltd., in accordance with JIS K-6714. The value (%) which subtracted the haze measured in the state which dripped several drops was made into internal haze. The results are shown in the table below.

(Production of polarizing plate)

Iodine was adsorbed to the stretched polyvinyl alcohol film to prepare a polarizer. The thickness of the polarizer was prepared by changing the film thickness and the draw ratio of the unstretched polyvinyl alcohol film.

Next, according to the following process, the cellulose acylate film of an Example and a comparative example was bonded to one surface of the polarizer, and the other polarizing plate protective film of the following table was bonded to the other surface.

Process 1: It was immersed in 1.5 mol / L sodium hydroxide solution of 55 degreeC for 120 second, and then it was washed with water. Furthermore, after immersing in 0.005 mol / L of the diluted sulfuric acid aqueous solution for 1 minute, it was immersed in water, and the diluted sulfuric acid aqueous solution was wash | cleaned enough. Finally, the sample was sufficiently dried at 120 ° C. It dried and obtained the cellulose acetate film which saponified the side to bond with a polarizer.

Process 2: The said polarizer was immersed for 1-2 second in the polyvinyl alcohol adhesive tank of 2 mass% of solid content.

Process 3: The excess adhesive adhering to the polarizer in process 2 was lightly wiped and removed, and this was placed on the cellulose ester film processed in the process 1, and it was arrange | positioned.

Process 4: The cellulose-ester film laminated | stacked at the process 3, a polarizer, and a back side cellulose-ester film were bonded together at the pressure of 20-30 N / cm <2> and a conveyance speed at about 2 m / min.

Process 5: The sample which bonded the polarizer manufactured by the process 4 and the cellulose ester film in the 80 degreeC drier was dried for 2 minutes, and the polarizing plate corresponding to a cellulose ester film was produced, respectively.

The transmission axis of a polarizer and the slow axis of the cellulose acylate film of each Example and comparative example which performed the saponification process above were arrange | positioned so that it might become parallel.

Films other than a cellulose acylate film of the 2nd polarizing plate protective film of the following table were bonded together with a polarizer as follows. On the film, the following UV curable adhesive agent was used as the film with the adhesive agent coated so that it might become 5 micrometers in thickness using a microgravure coater (gravure roll: # 300, rotation speed 140% / line speed). Subsequently, this was bonded to the polarizer immersed in the said polyvinyl alcohol adhesive agent with a roll group together with a cellulose ester film. The electron beam was irradiated from both sides of the bonded film, and the polarizing plate which has a film in both sides of the polarizer was obtained. The line speed was 20 m / min, the acceleration voltage was 250 kV, and the irradiation dose was 20 kGy.

<UV curing adhesive>

100 mass parts of 2-hydroxyethyl acrylates, and 11 mass parts of ditrimethylol propane tetraacrylate (Sartomer Japan Co., Ltd. make, brand name SR355) were mix | blended and the UV curing adhesive agent was prepared.

<2nd polarizing plate protective film (films other than a cellulose acylate film)>

COP ： Cycloolefin film (film thickness 25 μm)

PET: Polyethylene terephthalate film (film thickness 25 micrometers)

PC ： Polycarbonate film (film thickness 25 micrometers)

PMMA 1: (meth) acrylic resin film having a lactone ring structure of the following structure (film thickness of 25 μm)

[In the general formula, R ¹ is a hydrogen atom, R ² and R ^3. (Meth) acrylic resin ｛copolymerization monomer mass ratio having a lactone ring structure which is a silver methyl group = methyl methacrylate / 2- (hydroxymethyl) methyl acrylate = 8/2, lactone ring structure about 100%, content ratio of lactone ring structure 19.4%, mass average molecular weight 133000, melt flow rate 6.5 g / 10 min (240 ° C., 10 kgf), Tg 131 ° C.90 parts by mass, acrylonitrile-styrene (AS) resin ｛Toyo AS AS20, Toyo Styrene Preparation 10 parts by mass of mixture; Tg 127 캜]

PMMA 2: Coating the following low moisture-permeable layer (2 micrometers) on the said PMMA 1 (film thickness of 23 micrometers) (film thickness of 25 micrometers)

[Preparation of composition for low moisture vapor layer formation]

Chlorine-containing polymer ： R204

@Asahi Mars life & living Co., Ltd. production "Saran resin R204"} 12.0 g

Tetrahydrofuran 62.0 g

13.0 g of toluene

13.0 g of methyl ethyl ketone

[Formation of low moisture-permeable layer]

PMMA 1 film (23 micrometers) was taken out as a transparent protective film in roll form, and the said low moisture vapor transmission layer composition was apply | coated using a bar coater on the conditions of a film conveyance speed of 30 m / min, and it is 1 minute at 100 degreeC. It dried, and wound up after passing the zone of 25 degreeC 65% atmosphere for 1 minute, conveying a film. The film thickness of the low moisture-permeable layer at this time was 2.0 micrometers.

(Moisture permeability)

The water vapor transmission rate of the film used as a 2nd polarizing plate protective film was measured by the method prescribed | regulated to JISZ0208 (40 degreeC 90% RH24h).

(Mounting to liquid crystal display device)

The polarizing plate and the retardation plate of the front and back of the liquid crystal TV (LC-46LX1, the product made by SHARP) of VA mode were peeled off, and it used as a liquid crystal cell. The polarizing plate of each Example and a comparative example was provided as the visual recognition side polarizing plate of the liquid crystal display device using the said vertically-aligned liquid crystal cell, and a backlight side polarizing plate. At this time, the polarizing plate was provided so that a 1st polarizing plate protective film (the cellulose acylate film of Examples 1-25 and Comparative Examples 1-7) may become a liquid crystal cell side. The visual recognition side polarizing plate and the backlight side polarizing plate were affixed on the liquid crystal cell through an adhesive. It was set as cross nicol arrangement so that the transmission axis of the visual recognition side polarizing plate might be an up-down direction, and the transmission axis of a backlight side polarizing plate might be left-right direction.

The manufactured liquid crystal display device was used as the liquid crystal display device of each Example and a comparative example.

(Condensation nonuniformity of liquid crystal display device)

With the liquid crystal panel mounted with the prepared polarizing plate lying down horizontally, 500 μl of pure water was dropped on the surface of the viewer-side polarizing plate using a micropipette, and quickly covered with a film by Saran Lab (manufactured by Asahi Chemical Co., Ltd.). It was affixed with Kapton tape (made by Nitto Corporation) and sealed. The panel was turned on in this state and left still for 12 hours. Thereafter, the saran wrap was removed, the water adhered to the film surface was wiped off, and after lighting for 3 hours, the panel was observed in the inclined direction, and the presence or absence of nonuniformity was observed. A and B are practical levels.

A: The difference of light leakage between a water contact part and its surroundings is small

B: There is a difference in light leakage between the water contact part and its surroundings, but the boundary is unclear.

C: There is a difference in light leakage between the water contact portion and its surroundings, and the boundary is clear, and the water contact marks are outstanding.

(4 corner non-uniformity evaluation of the liquid crystal display device)

The liquid crystal panel on which the manufactured polarizing plate is mounted is placed in an environment of 40 ° C. 95% relative humidity for 24 hours and then in a 40 ° C. dry environment for 2 hours, after which the panel is turned on for 24 hours in an environment of 25 ° C. 60% relative humidity. The nonuniformity was observed from the front side. A and B are practical levels.

A: There is no light leakage at the 4 corners of the panel or the light leakage is very weak.

B: Light leak is seen at the 4 corners of the panel, but the boundary is indefinite, so light leak is inconspicuous

C: A light leak is seen in the corner of panel 4, and a boundary is clear, and the light leaked part and the non-light leaked part can be visually recognized clearly.

(Front Contrast Evaluation)

Using a measuring instrument (BM5A, manufactured by TOPCON), the luminance values of the black display and the white display in the panel front direction were measured to calculate the front contrast (white luminance / black luminance). A and B are practical levels.

The observed contrast was evaluated according to the following criteria.

A: The contrast is 6000 or more

B: Contrast is 5700 or more and less than 6000

C ： Contrast is less than 5700

(Curl Evaluation of Polarizing Plate)

After cutting the manufactured polarizing plate into the size of 10 cm x 10 cm, placing it in the temperature-humidity environment of 25 degreeC and 60% of a relative humidity for 48 hours or more, the distance to the point away from the plane when the polarizing plate is left on a plane Was the amount of curl.

A: The curl amount is less than ± 10 mm.

B: The amount of curl is ± 10 mm or more but less than ± 20 mm.

C ： More than ± 20mm curl amount

22: protective film
12: Poisson side polarizer
15: retardation film
13: liquid crystal layer
14: retardation film
11: backlight side polarizer
21: Protective film

Claims (15)

The cellulose acylate film which contains the cellulose acylate of all the acyl-group substitution degree 2.1-2.6, and satisfy | fills following (1)-(4).
(1) containing at least one polycondensation ester containing an aromatic dicarboxylic acid residue and an aliphatic diol residue, and the ratio of the aromatic dicarboxylic acid residue to all the dicarboxylic acid residues in the polycondensation ester is 70 It is mol% or more;
(2) the film thickness is 15 to 45 µm;
(3) the retardation (Rth) in the film thickness direction at a wavelength of 550 nm satisfies Rth / d ≧ 0.0025 (where d represents the film thickness (nm));
(4) The absolute value of Rth change at the time of water contact test is 5 nm or less.
(Here, the absolute value of the Rth change at the time of water contact test is taken out after immersing the film in water heated to 40 ° C for 12 hours, wipe off the water droplets on the film surface, and naturally dry it, and then at 25 ° C 60% relative humidity environment Absolute value of difference between Rth at wavelength 590 nm and untreated Rth after standing for 24 hours under the following conditions.) The method according to claim 1,
The cellulose acylate film whose internal haze of the said cellulose acylate film is 0.05% or less. The method according to claim 1,
The cellulose acylate film, wherein the cellulose acylate is cellulose acetate. The method according to claim 1,
The cellulose acylate film in which a cellulose acylate film is extended | stretched by Tg-70 degreeC-Tg-30 degreeC (Tg is glass transition temperature of a cellulose acylate) in the state of 35-65 mass% of residual solvents. . The method according to claim 1,
The cellulose acylate film whose internal haze of the said cellulose acylate film is 0.05% or less and whose said cellulose acylate is cellulose acetate. The method according to claim 1,
Cellulose acylate is cellulose acetate, the stretching temperature is Tg-70 ℃ to Tg-30 ℃ (Tg is the glass transition temperature of cellulose acylate) in the state of the residual solvent amount of 35 to 65% by mass Acylate film. The method according to claim 1,
The internal haze of the said cellulose acylate film is 0.05% or less, the said cellulose acylate is cellulose acetate, and extending | stretching temperature is Tg-70 degreeC-Tg-30 degreeC (Tg) in the state of 35-65 mass% of residual solvent amount. Is a glass transition temperature of a cellulose acylate), The cellulose acylate film formed by extending | stretching. A 1st polarizing plate protective film and a 2nd polarizing plate protective film are included, The said 1st polarizing plate protective film is a cellulose acylate film of Claim 1, The polarizing plate characterized by the above-mentioned. The method of claim 8,
The film thickness of the said 2nd polarizing plate protective film is 10-29 micrometers, The polarizing plate characterized by the above-mentioned. The method of claim 8,
The water vapor transmission rate of the said 2nd polarizing plate protective film is 100 g / m <2> * 24hr or less, The polarizing plate characterized by the above-mentioned. The liquid crystal display device which has a polarizing plate of Claim 8. The method of claim 11,
The liquid crystal display device in which the said 1st polarizing plate protective film is arrange | positioned so that it may be a liquid crystal cell side. The method of claim 11,
The liquid crystal display device which is arrange | positioned so that a said 1st polarizing plate protective film may become a liquid crystal cell side, and has glass of 50-500 micrometers in thickness. Stretching temperature of a cellulose acylate film in Tg-70 degreeC-Tg-30 degreeC (Tg is glass transition temperature of a cellulose acylate) in the state of 35-65 mass% of residual solvents, The said cellulose The acylate film contains the cellulose acylate of all the acyl-group substitution degree 2.1-2.6, and satisfy | fills following (1) and (2), The manufacturing method of the cellulose acylate film characterized by the above-mentioned.
(1) containing at least one polycondensation ester containing an aromatic dicarboxylic acid residue and an aliphatic diol residue, and the ratio of the aromatic dicarboxylic acid residue to all the dicarboxylic acid residues in the polycondensation ester is 70 It is mol% or more;
(2) The film thickness is 15-45 micrometers. 15. The method of claim 14,
The said cellulose acylate film is a manufacturing method of the cellulose acylate film which is the cellulose acylate film of any one of Claims 1-7.

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