JP2017149001A - Laminate, polarizing plate and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate having a cellulose ester resin layer which is excellent in interlayer adhesion, can effectively suppress permeation of a moisture content even when thinned, can be strongly bonded to a polarizer when used as a protective film of the polarizer, and can effectively suppress deterioration in the polarizer even under high temperature and high humidity condition; a polarizing plate using the laminate; and an image display device using the polarizing plate.SOLUTION: There are provided a laminate which has a cellulose ester resin layer, and a layer that comes in contact with the cellulose ester resin layer and contains a polymer having an alkaline hydrolyzable group; a polarizing plate using the laminate; and an image display device using the polarizing plate.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminate, a polarizing plate using the laminated body, and an image display device using the polarizing plate.

Image display devices represented by electroluminescence displays (ELDs) and liquid crystal display devices (LCDs) are increasingly required to be thin. In addition, the usage environment of image display devices has been diversified, including outdoor applications, and image display devices have the ability to stably maintain good image quality even in harsh environments (high durability). Is now required.
The decrease in image quality in the image display device is partly caused by water entering the polarizing plate and degrading the polarizer. The polarizer is protected by laminating a protective film (optical film) on the surface, but the protective film is also required to be thin. When the protective film is thinned, moisture is more likely to come into contact with the polarizer, and the image quality is likely to deteriorate. In order to make a practical polarizing plate, it is also important to improve the adhesion between the protective film and the polarizer.

  As the protective film, cellulose ester resins and acrylic resins are widely used from the viewpoints of versatility and processability. From the need to further enhance the protective effect of the polarizer, optical films are being modified (for example, Patent Documents 1 to 5).

International Publication No. 2009/047924 JP 2012-172062 A JP 2006-83225 A JP 2013-101281 A JP-A-9-197128

As a result of repeated studies on the polarizer protective function of the protective film, the present inventors clearly show that the conventional protective film structure including the films described in the above patent documents cannot sufficiently cope with the problem of polarizer deterioration. It has become. That is, it has been found that if the protective film is formed of a highly hydrophobic polymer in order to suppress moisture permeability to a high degree, it is difficult to stably maintain the adhesion between the protective film and the polarizer. In order to solve this problem, when a protective film is formed using a blended resin of a highly hydrophobic polymer and cellulose ester, the adhesion between the protective film and the polarizer is improved to some extent, but it is particularly thinned. It has become clear that it is difficult to enhance the function of reducing moisture permeability to the desired level.
The present invention is a laminate comprising a cellulose ester resin layer, excellent in interlayer adhesion, can effectively suppress moisture permeability even when thinned, and when used as a protective film for a polarizer Laminated body that can be firmly adhered to the polarizer and can effectively suppress the deterioration of the polarizer even under high temperature and high humidity conditions, a polarizing plate using the laminated body, and an image using the polarizing plate It is an object to provide a display device.

As a result of intensive studies in view of the above problems, the present inventors have found that a laminate in which a layer containing a polymer having an alkali hydrolyzable group is directly provided on a cellulose ester resin layer is obtained by combining a layer containing the polymer with cellulose. It has been found that the adhesiveness between the layers with the ester resin layer is excellent, and that the moisture permeability can be kept low even if the layer is thinned. Further, when the laminate is used as a protective film for a polarizer, the present inventors can generate hydroxy groups on the surface of the polymer layer by saponification treatment performed before bonding to the polarizer. It has been found that the layer can be firmly adhered to the surface of the polarizer, and as a result, deterioration of the polarizer can be effectively suppressed even under high temperature and high humidity conditions.
The present invention has been further studied based on these findings and has been completed.

一般式（１）中、Ａは単結合又は２価の基を示す。Ｚは下記一般式ＬＣ−１〜ＬＣ−１７から選ばれる基を示す。＊は連結部位を示す。

一般式ＬＣ−１〜ＬＣ−１７中、Ｒ^２は置換基を示す。＊＊はＡとの連結部位を示す。ｎは０〜４の整数である。

一般式（２）中、Ｒ^ａ〜Ｒ^ｄは水素原子又はアルキル基を示す。Ｒ^ｅはアルキル基を示す。＊は連結部位を示す。

一般式（３）中、Ｌ^１は単結合又は２価の基を示す。ｎ^１は１又は２である。＊は連結部位を示す。

一般式（４）中、Ｒ^ｆ〜Ｒ^ｉは水素原子、アルキル基又はハロゲン原子を示す。Ｘは電子求引性基を示す。＊は連結部位を示す。

一般式（５）中、Ｌ^２は単結合又は２価の基を示す。Ｚ^ａは一般式（５ａ）又は（５ｂ）で表される基を示す。＊は連結部位を示す。
一般式（５ａ）中、Ｒ^ｊ、Ｒ^ｋ及びＲ^ｍは水素原子又はアルキル基を示す。＊＊＊はＬ^２との連結部位を示す。
一般式（５ｂ）中、Ｒ^ｐ、Ｒ^ｑ、Ｒ^ｒ、Ｒ^ｓ及びＲ^ｔは水素原子又はアルキル基を示す。＊＊＊はＬ^２との連結部位を示す。

一般式（６）中、Ｌ^３は単結合又は２価の基を示す。Ｒ^ｕはアルキル基を示す。＊は連結部位を示す。

一般式（７）中、Ｌ^４は単結合又は２価の基を示す。Ｒ^ｖはアルキル基を示す。＊は連結部位を示す。
〔３〕
上記ポリマー中、上記アルカリ加水分解性基の含有量が０．００００１〜０．０２モル／ｇである、〔１〕又は〔２〕記載の積層体。
〔４〕
上記アルカリ加水分解性基を有するポリマーが下記一般式（１ａ）で表される繰り返し単位を有する、〔１〕〜〔３〕のいずれかに記載の積層体。

一般式（１ａ）中、Ｒ^Ａは水素原子、ハロゲン原子又はアルキル基を示す。
Ｒ^Ｂ及びＲ^Ｃは水素原子、アルキル基、アリール基又はアルコキシカルボニル基を示す。
Ｌ^Ａは単結合であるか、又は、アルキレン基、アリーレン基、−Ｃ（＝Ｏ）−、−Ｏ−及び−ＮＲ^Ｄ−から選ばれる２価の基もしくはこれらの基の２種以上を組合せてなる２価の連結基を示す。Ｒ^Ｄは水素原子又は置換基を示す。
＊１は上記一般式（１）〜（７）のいずれかで表されるアルカリ加水分解性基を示す。
〔５〕
上記アルカリ加水分解性基を有するポリマーが下記一般式（１ｂ）で表される繰り返し単位を有する、〔１〕〜〔４〕のいずれかに記載の積層体。

一般式（１ｂ）中、Ａ及びＺは、それぞれ上記一般式（１）におけるＡ及びＺと同義である。Ｒ^Ａ１は水素原子、ハロゲン原子又は炭素数１〜４のアルキル基を示す。
〔６〕
〔１〕〜〔５〕のいずれかに記載の積層体と、偏光子とを有する偏光板。
〔７〕
〔６〕に記載の偏光板を有する画像表示装置。 The above-described problems of the present invention have been solved by the following means.
[1]
A laminate comprising a cellulose ester resin layer and a layer containing a polymer having an alkali hydrolyzable group in contact with the cellulose ester resin layer.
[2]
The laminate according to [1], wherein the alkali hydrolyzable group is represented by any one of the following general formulas (1) to (7).

In general formula (1), A represents a single bond or a divalent group. Z represents a group selected from the following general formulas LC-1 to LC-17. * Indicates a linking site.

In General Formulas LC-1 to LC-17, R ² represents a substituent. ** indicates the site of connection with A. n is an integer of 0-4.

In the general formula ^(2), R a ~R ^d represents a hydrogen atom or an alkyl group. ^Re represents an alkyl group. * Indicates a linking site.

In General Formula (3), L ¹ represents a single bond or a divalent group. n ¹ is 1 or 2. * Indicates a linking site.

In the general formula ^(4), R f ~R ⁱ represents a hydrogen atom, an alkyl group or a halogen atom. X represents an electron withdrawing group. * Indicates a linking site.

In General Formula (5), L ² represents a single bond or a divalent group. Z ^a represents a group represented by the general formula (5a) or (5b). * Indicates a linking site.
In general formula (5a), R ^j , R ^k and R ^m represent a hydrogen atom or an alkyl group. *** indicates the linking site and ^{L 2.}
In the general formula ^{(5b), R p, R} q, R r, R s and ^{R t} represents a hydrogen atom or an alkyl group. *** indicates the linking site and ^{L 2.}

In General Formula (6), L ³ represents a single bond or a divalent group. R ^u represents an alkyl group. * Indicates a linking site.

In General Formula (7), L ⁴ represents a single bond or a divalent group. R ^v represents an alkyl group. * Indicates a linking site.
[3]
The laminate according to [1] or [2], wherein the content of the alkali hydrolyzable group in the polymer is 0.00001 to 0.02 mol / g.
[4]
The laminate according to any one of [1] to [3], wherein the polymer having an alkali hydrolyzable group has a repeating unit represented by the following general formula (1a).

In the general formula (1a), R ^A represents a hydrogen atom, a halogen atom or an alkyl group.
R ^B and R ^C represent a hydrogen atom, an alkyl group, an aryl group or an alkoxycarbonyl group.
L ^A is a single bond, or a divalent group selected from an alkylene group, an arylene group, —C (═O) —, —O—, and —NR ^D —, or a combination of two or more of these groups. And a divalent linking group. R ^D represents a hydrogen atom or a substituent.
* 1 represents an alkali hydrolyzable group represented by any one of the above general formulas (1) to (7).
[5]
The laminate according to any one of [1] to [4], wherein the polymer having an alkali hydrolyzable group has a repeating unit represented by the following general formula (1b).

In general formula (1b), A and Z have the same meanings as A and Z in general formula (1), respectively. R ^A1 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms.
[6]
A polarizing plate comprising the laminate according to any one of [1] to [5] and a polarizer.
[7]
The image display apparatus which has a polarizing plate as described in [6].

  In the present specification, the numerical value range represented by “to” means that the numerical values described before and after it are included as the lower limit value and the upper limit value.

  In the present specification, when there are a plurality of substituents, linking groups, and the like (hereinafter referred to as substituents) indicated by specific symbols, or when a plurality of substituents are specified simultaneously or alternatively, It means that a substituent etc. may mutually be same or different. The same applies to the definition of the number of substituents and the like. Further, when a plurality of substituents and the like are close (especially adjacent), they may be connected to each other or condensed to form a ring.

In this specification, about the display of a compound, it uses in the meaning containing its salt and its ion besides the compound itself. In addition, it means that a part of the structure is changed as long as the desired effect is achieved.
Examples of the salt of the compound include, for example, an acid addition salt of the compound formed with the compound and an inorganic acid or an organic acid, or a base addition salt of the compound formed with the compound and an inorganic base or an organic base. Is mentioned. In addition, examples of the ion of the compound include an ion including a skeleton of the compound formed by dissociating the salt of the above-described compound.
In the present specification, a substituent that does not specify substitution or non-substitution (the same applies to a linking group) means that the group may have an arbitrary substituent as long as a desired effect is achieved. . This is also the same for compounds that do not specify substitution or non-substitution.
In the present specification, the term “substituent” includes groups selected from the following substituent group T unless otherwise specified. In addition, when only a substituent having a specific range is described (for example, when only described as “alkyl group”), a corresponding group of the following substituent group T (in the above case, an alkyl group) The preferred range in FIG.
In the present specification, when the number of carbon atoms of a certain group is defined, this number of carbons means the total number of carbon atoms in the group. That is, when this group is a form further having a substituent, it means the total number of carbon atoms including this substituent.

Substituent group T:
An alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms such as a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, an n-octyl group, n-decyl group, n-hexadecyl group, etc.), cycloalkyl group (preferably having 3 to 20, more preferably 3 to 12, particularly preferably 3 to 8 carbon atoms, cyclopropyl group) , A cyclopentyl group, a cyclohexyl group, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms such as vinyl group, allyl group, 2- Butenyl group, 3-pentenyl group, etc.), alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferred). Is 2-8, for example, propargyl group, 3-pentynyl group, etc.), aryl group (preferably 6-30, more preferably 6-20, particularly preferably 6-12, For example, a phenyl group, a biphenyl group, a naphthyl group, etc. are mentioned.), An amino group (preferably 0-20 carbon atoms, more preferably 0-10, particularly preferably 0-6, for example, amino group, methylamino Group, dimethylamino group, diethylamino group, dibenzylamino group, etc.), alkoxy group (preferably 1-20 carbon atoms, more preferably 1-12, particularly preferably 1-8, for example methoxy Group, ethoxy group, butoxy group, etc.), aryloxy group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms). Particularly preferred is 6 to 12, for example, phenyloxy group, 2-naphthyloxy group, etc.), acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 1 carbon atoms). 12 such as an acetyl group, a benzoyl group, a formyl group, a pivaloyl group, etc.), an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms). For example, a methoxycarbonyl group, an ethoxycarbonyl group, etc.), an aryloxycarbonyl group (preferably having 7 to 20, more preferably 7 to 16, particularly preferably 7 to 10 carbon atoms such as phenyloxy Carbonyl group, etc.), acyloxy group (preferably having 2 to 20 carbon atoms, more preferred) 2 to 16, particularly preferably 2 to 10, and examples thereof include an acetoxy group and a benzoyloxy group. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms such as acetylamino group and benzoylamino group), alkoxycarbonylamino group ( The number of carbon atoms is preferably 2 to 20, more preferably 2 to 16, and particularly preferably 2 to 12, and examples thereof include a methoxycarbonylamino group, and an aryloxycarbonylamino group (preferably 7 to 7 carbon atoms). 20, More preferably, it is 7-16, Most preferably, it is 7-12, for example, a phenyloxycarbonylamino group etc. are mentioned, A sulfonylamino group (preferably 1-20 carbon atoms, More preferably, it is 1-16. And particularly preferably 1 to 12, for example, methanesulfonylamino group, benzenesulfonate Amino groups, etc.), sulfamoyl groups (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms such as sulfamoyl group, methylsulfamoyl group, dimethylsulfa). And a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms such as a carbamoyl group and a methylcarbamoyl group). , Diethylcarbamoyl group, phenylcarbamoyl group, etc.), alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16, particularly preferably 1 to 12, such as methylthio group and ethylthio group) An arylthio group (preferably having 6 to 20 carbon atoms, More preferably, it is 6-16, Most preferably, it is 6-12, for example, a phenylthio group etc. are mentioned, A sulfonyl group (Preferably 1-20 carbon atoms, More preferably, it is 1-16, Most preferably, it is 1-1. 12, for example, a mesyl group, a tosyl group, etc.), a sulfinyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16, particularly preferably 1 to 12, such as a methanesulfinyl group, Benzenesulfinyl group, etc.), urethane group, ureido group (preferably 1-20 carbon atoms, more preferably 1-16, particularly preferably 1-12, for example, ureido group, methylureido group, phenyl Ureido groups, etc.), phosphoric acid amide groups (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms) Is preferably 1 to 12, and examples thereof include diethyl phosphoric acid amide and phenyl phosphoric acid amide. ), Hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, Heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom and a sulfur atom, specifically, for example, an imidazolyl group, a pyridyl group and a quinolyl group. , Furyl group, piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group, and the like, and silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, Particularly preferred is 3 to 24, and examples thereof include trimethylsilyl group and triphenylsilyl group. That).
These substituents may further have a substituent. Moreover, when there are two or more substituents, they may be the same or different. Further, adjacent substituents may be connected to each other to form a ring.

The laminate of the present invention is excellent in adhesion between layers and has low moisture permeability even if it is made thin. When the laminate of the present invention is used as a protective film for a polarizer, the laminate can be firmly adhered to the polarizer, and deterioration of the polarizer can be effectively suppressed even under high temperature and high humidity conditions.
The polarizing plate and the image display device of the present invention have the laminate of the present invention exhibiting the above effects as a polarizing plate protective film, and the deterioration of the polarizer can be effectively suppressed even under high temperature and high humidity conditions.
In the present specification, the degree of suppressing the deterioration of the polarizer under high temperature and high humidity conditions is also referred to as “polarizer durability” or “polarizing plate durability”.

FIG. 1 is a cross-sectional view showing an embodiment of the laminate of the present invention. FIG. 2 is a schematic diagram showing an outline of an embodiment of a liquid crystal display device including a polarizing plate incorporating the polarizing plate protective film of the present invention.

Preferred embodiments of the present invention are described below.
[Laminate]
As shown in FIG. 1, the laminate of the present invention comprises a cellulose ester resin layer 11 and a layer 12 containing a polymer having an alkali hydrolyzable group, which is directly provided on the cellulose ester resin layer 11 (hereinafter referred to as “the layer 12”). Simply referred to as “polymer layer”). Details of the cellulose ester resin layer 11 and the polymer layer 12 will be described later. In the laminate of the present invention, the polymer layer may be provided on one side of the cellulose ester resin layer 11 as shown in FIG. 1, or the polymer layer may be provided on both sides of the cellulose ester resin layer 11. There may be. More preferably, the laminate of the present invention has a form in which the polymer layer is provided on one side of the cellulose ester resin layer 11.
Two or more polymer layers having different composition ratios may be provided on the cellulose ester resin layer. When two or more polymer layers are formed, two or more polymer layers may be provided on one side of the cellulose ester resin layer, and two or more polymer layers may be provided on both sides of the cellulose ester resin layer. .

  Moreover, when the polymer layer is provided only on one side of the cellulose ester resin layer 11, the laminate of the present invention specializes in specific functions on the surface of the cellulose ester resin layer 11 opposite to the polymer layer. Various functional layers (not shown) may be included. Examples of such a functional layer include a hard coat layer, an antireflection layer, a light scattering layer, an antifouling layer, and an antistatic layer.

<Polymer layer>
The polymer layer which comprises the laminated body of this invention is demonstrated.

  In the present invention, the “polymer layer” refers to a polymer having an alkali hydrolyzable group (hereinafter referred to as “polymer (S)”. In the present specification, when simply referred to as “polymer”, polymer (S) or It means a layer containing 50% by mass or more of a corresponding polymer (for example, a polymer (S) and a polymer to be compared) and not a cellulose ester resin). Here, the content of the polymer (S) in the polymer layer is preferably 60% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, and particularly preferably 85% by mass or more. The higher the content of the polymer (S) in the polymer layer, the higher the adhesion to the cellulose ester resin layer and the low moisture permeability, and the more the deterioration of the polarizer when used as a protective film can be suppressed. It is preferable in that it can be performed. Therefore, the content of the polymer (S) in the polymer layer may be 100% by mass, and is usually 99% by mass or less. When the content of the polymer (S) in the polymer layer is not 100% by mass, the balance can contain various conventional additives. Examples of such additives include plasticizers, organic acids, dyes, polymers, retardation modifiers, ultraviolet absorbers, antioxidants, matting agents, and the like.

-Polymer (S)-
The polymer (S) has an alkali hydrolyzable group. In the present specification, the “alkali hydrolyzable group” means a group that is hydrolyzed by contact with water in the presence of an alkali (NaOH, KOH, etc.), resulting in a hydroxy group (—OH). . In addition, since a carboxy group or a sulfo group also has a hydroxy group in its structure, a substituent that generates a carboxy group or a sulfo group by alkali hydrolysis is also an alkali hydrolyzable group.

  In the alkali hydrolyzable group, as a functional group that is hydrolyzed when brought into contact with water in the presence of an alkali, for example, a lactone ring-containing group, an alkoxysulfonylphenyl group, a dicarboxylic anhydride structure-containing A group, an alkoxycarbonyl group, an epoxy group-containing group, an oxetanyl group-containing group, an alkoxycarbonylphenyl group, and an acyloxy group. Among these, the alkali hydrolyzable group preferably has a lactone ring.

The alkali hydrolyzable group has polarity. Therefore, it is presumed that it can interact relatively strongly with the cellulose ester resin layer described later, and is excellent in adhesiveness with the cellulose ester resin layer. In addition, the cellulose ester resin layer surface is partially densified by this adhesion, so that the hydrophobicity of the laminate is increased. As a result, the laminate using the polymer (S) has low moisture permeability (that is, permeates through the film). Excellent barrier performance against water. Therefore, by laminating the layer containing the polymer (S) and the cellulose ester resin to form a laminate, and using this as a polarizing plate protective film, the polarizer is effectively prevented from being exposed to water. It is estimated that it is possible to suppress the deterioration of the polarizer. In order to make the low moisture permeability more excellent, it is preferable that the alkali hydrolyzable group does not have a hydroxy group before being hydrolyzed.
On the other hand, since the polarizer is usually formed using polyvinyl alcohol as a material, the polymer having an alkali hydrolyzable group described above has greatly increased interaction with the polarizer due to the action of the hydroxy group generated after hydrolysis. Therefore, a film formed using the polymer (S) and a cellulose ester resin, which will be described later, are laminated, and then treated with an alkali (this alkali treatment includes a saponification treatment that is usually performed in the production of a polarizing plate). Producing a polarizing plate with excellent adhesion between the polarizer and the protective film by forming a hydroxy group on the surface of the polymer layer and using it as a polarizing plate protective film in such a manner that the polymer layer side is in contact with the polarizer. Is possible.

  The alkali hydrolyzable group possessed by the polymer (S) is preferably represented by any one of the following general formulas (1) to (7).

  In the general formula (1), * indicates a linking site for incorporation into the polymer (S). p is 0 or 1, and 1 is preferable.

A represents a single bond or a divalent group.
When A is a divalent group, the divalent group is an alkylene group, a divalent alicyclic hydrocarbon group (a divalent group obtained by removing two hydrogen atoms contained in the ring-constituting atoms of the alicyclic hydrocarbon). Divalent aromatic hydrocarbon group (meaning a divalent group obtained by removing two hydrogen atoms of the ring atoms of the aromatic hydrocarbon), -O- or C (= O)- Or a divalent linking group formed by combining two or more of these groups.
When A is an alkylene group or an alkylene group is incorporated in A, the alkylene group may be linear or branched. 1-10 are preferable, as for carbon number of this alkylene group, 1-6 are more preferable, and 1-3 are more preferable.
When A is a divalent alicyclic hydrocarbon group or a divalent alicyclic hydrocarbon group is incorporated in A, the divalent alicyclic hydrocarbon group has a monocyclic structure. It may be a polycyclic structure. The divalent alicyclic hydrocarbon group preferably has 2 to 30 carbon atoms, and more preferably 2 to 10 carbon atoms.
When A is a divalent aromatic hydrocarbon group, or when a divalent aromatic hydrocarbon group is incorporated in A, the divalent aromatic hydrocarbon group may be a monocyclic structure It may be a polycyclic structure. The divalent aromatic hydrocarbon group preferably has 5 to 20 carbon atoms, and more preferably 5 to 12 carbon atoms.

  The molecular weight of A is preferably 14 to 600, more preferably 14 to 400.

Among them A is either a single bond or ^-A 1 -C (= O) is preferably a divalent linking group represented by -O-. A ¹ represents an alkylene group or a cycloalkylene group.
When A ¹ is an alkylene group, the alkylene group may be linear or branched. 1-10 are preferable, as for carbon number of this alkylene group, 1-6 are more preferable, 1-3 are more preferable, and it is especially preferable that they are a methylene group or ethylene group.
When A ¹ is a cycloalkylene group, the cycloalkylene group preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and still more preferably 5 to 10 carbon atoms. Preferable specific examples of the cycloalkylene group include, for example, a cyclohexylene group, an adamantylene group, and a norbornylene group.

  Z represents a group selected from the following general formulas LC-1 to LC-17.

In the above LC-1 to LC-17, R ² represents a substituent, and ** represents a linking site with A. In the case where A is a single bond, ** is a connecting site between A and an adjacent atom (for example, oxygen atom when p is 1).
n is an integer of 0 to 4, preferably 0 to 3, and more preferably 0 to 2.

When R ² is a substituent, examples of the substituent include a group selected from the above substituent group T. Among them, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, a carboxy group, a halogen atom, a hydroxy group, Or a cyano group is preferable and an alkyl group is especially preferable.
When R ² is an alkyl group, the alkyl group may be linear or branched. 1-10 are preferable, as for carbon number of this alkyl group, 1-6 are more preferable, 1-3 are more preferable, More preferably, it is methyl or ethyl.
When R ² is a cycloalkyl group, the cycloalkyl group preferably has 3 to 12 carbon atoms, more preferably 4 to 10 carbon atoms, particularly preferably 5 to 8 carbon atoms, and further preferably cyclopentyl or cyclohexyl.
When R ² is an alkoxy group, the alkoxy group may be linear or branched. 1-10 are preferable, as for carbon number of this alkoxy group, 1-6 are more preferable, 1-3 are more preferable, More preferably, it is methoxy or ethoxy.
When R ² is an alkoxycarbonyl group, the alkoxycarbonyl group may be linear or branched. 1-12 are preferable, as for carbon number of this alkoxycarbonyl group, 1-8 are more preferable, 1-6 are more preferable, More preferably, they are methoxycarbonyl or ethoxycarbonyl.
When there are two or more R ² (when n is 2 or more), two adjacent R ² may be connected to each other to form a ring. The ring formed is preferably a 5-membered ring or a 6-membered ring, and more preferably a 5-membered ring. Moreover, this ring may further have a substituent, and when there are two or more such substituents, they may be linked to each other to form a ring.

  LC-1 to LC-17 are alkali hydrolyzable groups. Taking LC-1 as an example, the structure after alkaline hydrolysis is shown below.

  More preferably, Z is LC-1, LC-4, LC-5, LC-6, LC-8 or LC-16.

  Specific examples of the substituent represented by the general formula (1) are shown below, but the present invention is not limited thereto. In the following structure, Me represents methyl. Moreover, * is a connection part corresponding to * in General formula (1).

  In the general formula (2), * indicates a linking site for incorporation into the polymer (S).

R ^{a to} R ^d represent a hydrogen atom or an alkyl group, and R ^e represents an alkyl group.
When R ^{a to} R ^d are alkyl groups, they may be linear or branched. 1-10 are preferable, as for carbon number of this alkyl group, 1-6 are more preferable, 1-3 are more preferable, More preferably, it is methyl or ethyl.
Although all of R ^{a to} R ^d may be in the form of an alkyl group, 0 to 2 of R ^{a to} R ^d are preferably alkyl groups. In a more preferred form of the general formula (2), R ^{a to} R ^d are all hydrogen atoms.

The alkyl group R ^e preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and particularly preferably 2 or 3. Of these, R ^e is preferably an alkyl group having 2 or 3 carbon atoms (preferably an ethyl group) and having an electron-withdrawing group as a substituent at the β-position of the alkyl group.
Examples of the electron withdrawing group include a halogen atom, a cyano group, and an acyl group (preferably an acyl group having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, and still more preferably 2 to 3 carbon atoms). An alkoxycarbonyl group (preferably having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, and further preferably an alkoxycarbonyl group having 2 to 3 carbon atoms), an aryloxycarbonyl group (preferably having 7 to 16 carbon atoms, more preferably Is an aryloxycarbonyl group having 7 to 13 carbon atoms), a carbamoyl group, an alkylsulfonyl group, or an arylsulfonyl group (preferably having 1 to 10, more preferably 1 to 5, more preferably 1 to 3 carbon atoms). Group), sulfamoyl group, perfluoroalkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 carbon atom) 10, more preferably include perfluoroalkyl group) having 1 to 8 carbon atoms. The electron withdrawing group is more preferably a halogen atom (preferably a fluorine atom) or a cyano group, and a cyano group is particularly preferable.

  The structure after the alkali group hydrolyzing the substituent represented by the general formula (2) is shown below.

  Specific examples of the substituent represented by the general formula (2) are shown below, but the present invention is not limited thereto.

In the general formula (3), * indicates a linking site for incorporation into the polymer (S). n ¹ is 1 or 2, and 1 is preferable.

L ¹ represents a single bond or a divalent group.
When L ¹ is a divalent group, the divalent group is preferably an alkylene group. This alkylene group may be linear or branched. L number ¹ is preferably carbon in the case of the alkylene group is preferably 1 to 10, more preferably 1 to 6, more preferably 1 to 3, more preferably methylene.

  The structure after the alkali group hydrolyzing the substituent represented by the general formula (3) is shown below.

  In the general formula (4), * indicates a linking site for incorporation into the polymer (S).

R ^{f to} R ⁱ represent a hydrogen atom, an alkyl group, or a halogen atom.
When R ^{f to} R ⁱ are alkyl groups, they may be linear, branched, or cyclic. When R ^f to R ⁱ is an alkyl group, the number of carbon atoms is preferably 1 to 10, more preferably 1 to 6, more preferably 1 to 3, more preferably methyl or ethyl. When two adjacent groups among R ^{f to} R ⁱ are alkyl groups, the two adjacent alkyl groups may be linked to each other to form a ring. Such a ring structure is preferably an alicyclic ring, more preferably a cyclohexane ring.
When R ^{f to} R ⁱ are halogen atoms, the halogen atoms are preferably fluorine atoms.
R ^{f to} R ⁱ are preferably hydrogen atoms.

X represents an electron withdrawing group.
Examples of the electron withdrawing group include a halogen atom, a cyano group, and an acyl group (preferably an acyl group having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, and still more preferably 2 to 3 carbon atoms). An alkoxycarbonyl group (preferably having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, and further preferably an alkoxycarbonyl group having 2 to 3 carbon atoms), an aryloxycarbonyl group (preferably having 7 to 16 carbon atoms, more preferably Is an aryloxycarbonyl group having 7 to 13 carbon atoms), a carbamoyl group, an alkylsulfonyl group, or an arylsulfonyl group (preferably having 1 to 10, more preferably 1 to 5, more preferably 1 to 3 carbon atoms). Group), sulfamoyl group, perfluoroalkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 carbon atom) 10, more preferably include perfluoroalkyl group) having 1 to 8 carbon atoms. The electron withdrawing group is more preferably a halogen atom (preferably a fluorine atom), a cyano group or a perfluoroalkyl group, and a cyano group is particularly preferable.

  The structure after the alkali group hydrolyzing the substituent represented by the general formula (4) is shown below.

  Specific examples of the substituent represented by the general formula (4) are shown below, but the present invention is not limited thereto.

  In the general formula (5), * indicates a linking site for incorporation into the polymer (S).

L ² represents a single bond or a divalent group.
When L ² is a divalent group, the divalent group is preferably an alkylene group. This alkylene group may be linear or branched. L ² is preferably a carbon number in the case of the alkylene group is preferably 1 to 10, more preferably 1 to 6, more preferably 1 to 3, more preferably methylene.

Z ^a represents a group represented by the general formula (5a) or (5b).
In the general formula (5a) or (5b), *** indicates the linking site and ^{L 2.} Note that when ^{L 2} is a single bond, in the general formula (5a) or (5b) *** becomes linking site with an oxygen atom.

R ^j , R ^k , R ^m , R ^p , R ^q , R ^r , R ^s and R ^t represent a hydrogen atom or an alkyl group.
When R ^j , R ^k , R ^m , R ^p , R ^q , R ^r , R ^s and R ^t are alkyl groups, the alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms. ~ 3 is more preferred, more preferably methyl or ethyl.
In the general formula (5a), 0 to 2 of R ^j , R ^k and R ^m are preferably alkyl groups, and 0 or 1 is more preferably alkyl.
In the general formula ^(5b), R ^p, preferably 0-3 of ^{R q,} R ^r, R ^s and ^{R t} is an alkyl group, more preferably 0-2 is alkyl, More preferably, 0 or 1 is an alkyl group.

  The structure after alkaline hydrolysis of the substituent represented by the general formula (5a) and the substituent represented by the general formula (5b) is shown below.

  Specific examples of the substituent represented by the general formula (5a) or (5b) are shown below, but the present invention is not limited thereto.

  In the general formula (6), * indicates a linking site for incorporation into the polymer (S).

L ³ represents a single bond or a divalent group.
When L ³ is a divalent group, a divalent linking group formed by combining —O—, —C (═O) —, —NR— and an alkylene group is preferred, and —C (═O) —O-alkylene is preferred. A divalent linking group represented by the group-or -C (= O) -NR-alkylene group- is more preferable. R represents a hydrogen atom, an alkyl group or an aryl group.
When an alkylene group is contained in L ³ , the alkylene group may be linear or branched. 1-10 are preferable, as for carbon number of this alkylene group, 1-6 are more preferable, and 1-3 are more preferable.

R ^u represents an alkyl group. The alkyl group R ^u may be linear or branched. The number of carbon atoms in the alkyl group ^{R u} is preferably 1 to 10, more preferably 1 to 6, more preferably 1 to 3, more preferably methyl or ethyl.

  The structure after alkaline hydrolysis of the substituent represented by the general formula (6) is shown below.

  Specific examples of the substituent represented by the general formula (6) are shown below, but the present invention is not limited thereto.

  In the general formula (7), * indicates a linking site for incorporation into the polymer (S).

L ⁴ represents a single bond or a divalent group.
When L ⁴ is a divalent group, a divalent linking group formed by combining —O—, —C (═O) —, —NR— and an alkylene group is preferable, —C (═O) —O—, A divalent linking group represented by -C (= O) -O-alkylene group- or -C (= O) -NR- is more preferable. R represents a hydrogen atom, an alkyl group or an aryl group.
When an alkylene group is contained in L ⁴ , the alkylene group may be linear or branched. 1-10 are preferable, as for carbon number of this alkylene group, 1-6 are more preferable, and 1-3 are more preferable.

R ^v represents an alkyl group or an aryl group. When ^Rv is an alkyl group, the alkyl group may be linear or branched, and may be cyclic. The number of carbon atoms in the alkyl group ^{R v} is preferably 1 to 10, more preferably 1 to 6, more preferably 1 to 3, more preferably methyl or ethyl. The alkyl group may be substituted with a halogen atom.
When ^Rv is an aryl group, a phenyl group or a naphthyl group is preferable, and a phenyl group is more preferable.

  The structure after alkaline hydrolysis of the substituent represented by the general formula (7) is shown below.

  Specific examples of the substituent represented by the general formula (7) are shown below, but the present invention is not limited thereto.

  The polymer (S) preferably has a repeating unit represented by the following general formula (1a). The polymer (S) may have two or more repeating units represented by the following general formula (1a).

In the general formula (1a), R ^A represents a hydrogen atom, a halogen atom or an alkyl group.
When R ^A is a halogen atom, the halogen atom is a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.
When R ^A is an alkyl group, the alkyl group may be linear or branched. 1-10 are preferable, as for carbon number of this alkyl group, 1-5 are more preferable, and 1-3 are more preferable. The alkyl group ^RA is more preferably methyl, hydroxymethyl or trifluoromethyl, methyl or ethyl, and even more preferably methyl.
R ^A is more preferably a hydrogen atom or methyl.

When R ^B and R ^C are an alkyl group, the alkyl group may be linear or branched. 1-10 are preferable, as for carbon number of this alkyl group, 1-5 are more preferable, 1-3 are more preferable, More preferably, it is methyl or ethyl, More preferably, it is methyl.
When R ^B and R ^C are an aryl group, the aryl group preferably has 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, particularly preferably 6 to 12 carbon atoms, and particularly preferably phenyl.
When R ^B and R ^C are alkoxycarbonyl groups, the alkoxycarbonyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still more preferably methoxycarbonyl or ethoxycarbonyl.
R ^B and R ^C are more preferably a hydrogen atom.

L ^A is a single bond, or a divalent group selected from an alkylene group, an arylene group, —C (═O) —, —O—, and —NR ^D —, or a combination of two or more of these groups. And a divalent linking group. R ^D represents a hydrogen atom or a substituent. When ^RD is a substituent, examples of the substituent include a group selected from the substituent group T described above, and an alkyl group is particularly preferable. 1-6 are preferable, as for carbon number of this alkyl group, 1-4 are more preferable, and methyl or ethyl is further more preferable.
In linking groups L ^A divalent formed by combining two or more divalent groups described above, the number of the divalent group combined is not particularly limited, for example, preferably 2 to 9, 2 or Three is more preferable. Also, the combination of the linking groups is not particularly limited. For example, a combination of -C (= O)-, -O- and an alkylene group, or a combination of -C (= O)-, -O- and an arylene group. Are preferable, and a combination of —C (═O) —, —O— and an alkylene group is more preferable. Among them, ^{L A} is -C (= O) - is a divalent group containing a, -C (= O) - it is more preferably bonded to the main chain of the polymer (S).
The alkylene group L ^A or the alkylene group incorporated in L ^A is preferably linear. Moreover, 1-5 are preferable, as for carbon number of this alkylene group, 1-4 are more preferable, 1-3 are more preferable, and 2 is especially preferable.
The arylene group L ^A or the arylene group incorporated in L ^A preferably has 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, particularly preferably 6 to 12 carbon atoms, and particularly preferably phenylene.
L ^A is also preferably a single bond.

* 1 represents an alkali hydrolyzable group represented by any one of the above general formulas (1) to (7). That is, the connecting portion of the alkaline-hydrolyzable group represented by any one of General Formulas (1) to (7) * is linked with L ^A in the general formula (1a) (L ^A is a single bond In this case, the connecting part * of the alkali hydrolyzable group represented by any one of the general formulas (1) to (7) is connected to the carbon atom constituting the main chain of the polymer (S). ).

  When the polymer (S) has a repeating unit represented by the general formula (1a), part or all of the repeating unit represented by the general formula (1a) is represented by the following general formula (MC). A repeating unit is preferred.

In the general formula (MC), R ^A and * 1 have the same meanings as R ^A and * 1 in the general formula (1a), respectively, and preferred forms are also the same.

  When the polymer (S) has a repeating unit represented by the general formula (MC), a part or all of the repeating unit represented by the general formula (MC) is represented by the following general formula (1b). Preferably it is a unit.

In general formula (1b), A and Z have the same meanings as A and Z in general formula (1), respectively. R ^A1 represents a hydrogen atom, a halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atom) or an alkyl group having 1 to 4 carbon atoms.
When R ^A1 is an alkyl group having 1 to 4 carbon atoms, it is preferably methyl, hydroxymethyl or trifluoromethyl, more preferably methyl.
R ^A1 is more preferably a hydrogen atom or methyl.

  In the polymer (S) used in the present invention, the content of the alkali hydrolyzable group is preferably 0.00001 to 0.02 mol / g, and preferably 0.0005 to 0.01 mol / g. Is more preferably 0.001 to 0.01 mol / g, and further preferably 0.001 to 0.007 mol / g.

The polymer (S) may be a homopolymer or copolymer composed of only one or two or more repeating units having an alkali hydrolyzable group, or a repeat having an alkali hydrolyzable group. The copolymer comprised from the unit and the repeating unit which does not have an alkali hydrolysable group may be sufficient.
Preferable examples of the repeating unit having no alkali hydrolyzable group include a repeating unit derived from a (meth) acrylic acid ester compound. Preferable specific examples of such (meth) acrylate compounds include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and hexyl (meth) acrylate. , Cyclohexyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, allyl (meth) acrylate, phenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) acrylic Examples thereof include benzyl acid, 2-methoxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and tetrahydrofuryl (meth) acrylate.

  The polymer (S) includes a repeating unit represented by the general formula (1a) and a (meth) acrylic acid ester compound having no alkali hydrolyzable group (hereinafter referred to as “monomer (AE)”). It preferably consists of a repeating unit derived from. In this case, when the total of the molar amount of the repeating unit represented by the general formula (1a) constituting the polymer (S) and the molar amount of the repeating unit derived from the monomer (AE) is 100 mol%, 15-100 mol% is preferable, as for the molar amount of the repeating unit represented by General formula (1a), 20-100 mol% is more preferable, and 30-100 mol% is further more preferable.

The weight average molecular weight of the polymer (S) is preferably 10,000 to 1,000,000, more preferably 20,000 to 500,000, and further preferably 20,000 to 300,000. Preferably, it is 30,000-200,000.
The weight average molecular weight can be measured by the method described in Examples described later.

  The polymer (S) can be obtained by polymerizing a monomer having a specific structure corresponding to the structure of the target polymer (S) by a conventional method. For example, when the polymer (S) is composed of a monomer component having an ethylenically unsaturated bond, the target is obtained by heat treatment and / or light irradiation in the presence of a thermal polymerization initiator and / or a photopolymerization initiator. It can be obtained by polymerizing a monomer having a specific structure corresponding to the structure of the polymer (S).

  In this invention, there is no restriction | limiting in particular in the film thickness of the said polymer layer, 1-25 micrometers is preferable, 1-20 micrometers is more preferable, 1-15 micrometers is especially preferable. Moreover, 2-15 micrometers may be sufficient as this layer thickness, 3-15 micrometers may be sufficient, and 5-15 micrometers may be sufficient.

[Cellulose ester resin layer]
The cellulose ester resin layer which comprises the laminated body of this invention is a layer which contains 50 mass% or more of cellulose esters in a layer. 60 mass% or more is preferable, as for content of the cellulose ester in a cellulose-ester resin layer, 70 mass% or more is more preferable, 80 mass% or more is further more preferable, and 85 mass% or more is further more preferable. The upper limit of the content of the cellulose ester in the cellulose ester resin layer is usually 96% by mass or less, preferably 95% by mass or less, and more preferably 92% by mass or less. In this case, the remainder excluding the cellulose ester includes, for example, an additive described later.

<Cellulose ester>
The cellulose ester used as a raw material in the production of the cellulose ester resin layer of the present invention will be described.
Examples of the cellulose used as a raw material for the cellulose ester used in the present invention include cotton linter and wood pulp (hardwood pulp, softwood pulp). May be. Raw material cellulose is, for example, Marusawa, Uda, “Plastic Materials Course (17) Fibrous Resin”, Nikkan Kogyo Shimbun (published in 1970) and JSHI published technical bulletin No. 2001-1745 (page 7). To page 8) can be used.
As a cellulose ester, the well-known cellulose ester used for manufacture of a cellulose-ester film can be used without a restriction | limiting at all. Of these, cellulose acylate is preferably used.

(Cellulose acylate)
As the cellulose acylate used in the present invention, a known cellulose acylate used for producing a cellulose acylate film can be used without any limitation.
Glucose units having β-1,4 bonds constituting cellulose have free hydroxy groups at the 2nd, 3rd and 6th positions. Cellulose acylate is a polymer obtained by acylating a part of these hydroxy groups with an acyl group.
The degree of acyl substitution (hereinafter sometimes simply referred to as “degree of substitution”) indicates the degree of acylation of the hydroxy group of cellulose located at the 2-position, 3-position and 6-position, and is 2 for all glucose units. When the hydroxy groups at the 3rd, 6th and 6th positions are all acylated, the total degree of acyl substitution is 3. For example, in all glucose units, when only the 6-position is all acylated, the total acyl substitution degree is 1. Similarly, the total acyl substitution degree is 1 when all of either the 6-position and the 2-position are acylated in each glucose unit in all hydroxy groups of all glucose.
That is, the degree of substitution indicates the degree of acylation, assuming that 3 is when all the hydroxy groups in the glucose molecule are all acylated.
The degree of substitution of cellulose acylate is described in Tezuka et al., Carbohydrate. Res. , 273, 83-91 (1995), or according to the method prescribed in ASTM-D817-96.

  The total acyl substitution degree of the cellulose acylate used in the present invention is preferably 1.50 or more and 3.00 or less, more preferably 2.00 to 2.97, more preferably 2.30 or more from the viewpoint of moisture permeability. More preferably, it is less than 2.97, and particularly preferably 2.30-2.95.

  There is no restriction | limiting in particular in the acyl group of the cellulose acylate used for this invention, The form which has 1 type of acyl groups may be sufficient, and the form which has 2 or more types of acyl groups may be sufficient. The cellulose acylate that can be used in the present invention preferably has an acyl group having 2 or more carbon atoms as a substituent. The acyl group having 2 or more carbon atoms is not particularly limited, and may be an aliphatic acyl group or an aromatic acyl group. Specific examples of the acyl group having 2 or more carbon atoms include acetyl, propionyl, butanoyl, heptanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, isobutanoyl, tert-butanoyl, cyclohexanecarbonyl Oleoyl, benzoyl, naphthylcarbonyl, cinnamoyl and the like. Among these, acetyl, propionyl, butanoyl, dodecanoyl, octadecanoyl, tert-butanoyl, oleoyl, benzoyl, naphthylcarbonyl, and cinnamoyl are preferable, and acetyl, propionyl, and butanoyl are more preferable.

  Cellulose acetate using only an acetyl group as the acyl group of cellulose acylate can be suitably used in the present invention. The total acyl substitution degree of this cellulose acetate is 2.00 to 3 from the viewpoint of moisture permeability and optical properties. It is preferably 0.000, more preferably 2.20 to 3.00, still more preferably 2.30 to 3.00, still more preferably 2.30 to 2.97, It is especially preferable that it is 2.30-2.95.

A mixed fatty acid ester having two or more kinds of acyl groups can also be preferably used as the cellulose acylate in the present invention. Moreover, the mixed acid ester which has a fatty-acid acyl group and a substituted or unsubstituted aromatic acyl group as described in Paragraphs 0023-0038 of Unexamined-Japanese-Patent No. 2008-20896 can also be used preferably. Among them, the acyl group of the mixed fatty acid ester preferably includes an acetyl group and an acyl group having 3 to 4 carbon atoms. When the mixed fatty acid ester contains an acetyl group as an acyl group, the degree of acetyl substitution is preferably less than 2.5 and more preferably less than 1.9. On the other hand, when the acyl group having 3 to 4 carbon atoms is contained, the substitution degree of the acyl group having 3 to 4 carbon atoms is preferably 0.1 to 1.5, and preferably 0.2 to 1.2. Is more preferable, and 0.5 to 1.1 is particularly preferable.
As the cellulose ester resin layer used in the present invention, it is also preferable to employ a resin layer composed of a plurality of layers composed of different cellulose acylates by a co-casting method described later.

  The cellulose ester or cellulose acylate used in the present invention preferably has a polymerization degree of 250 to 800, more preferably 300 to 600. The cellulose ester or cellulose acylate used in the present invention has a number average molecular weight of preferably 40000 to 230,000, more preferably 60000 to 230,000, and most preferably 75000 to 200000. The degree of polymerization can be determined by ordering the number average molecular weight measured in terms of polystyrene by Gel Permeation Chromatography (GPC) with the molecular weight of the glucopyranose unit of cellulose ester or cellulose acylate.

The cellulose ester used in the present invention can be synthesized by a conventional method. For example, cellulose acylate can be synthesized using an acid anhydride or acid chloride as an acylating agent. When the acylating agent is an acid anhydride, an organic acid (for example, acetic acid) or methylene chloride is used as a reaction solvent. Further, a protic catalyst such as sulfuric acid can be used as the catalyst. When the acylating agent is an acid chloride, a basic compound can be used as a catalyst. In general industrial production of cellulose acylate, an organic acid (acetic acid, propionic acid, butyric acid, etc.) or an acid anhydride (acetic anhydride, propionic anhydride, butyric anhydride, etc.) corresponding to the desired acyl group in cellulose is used. Is used to esterify the hydroxy group.
For example, a cellulose derived from cotton linter or wood pulp is used as a raw material, and this is activated with an organic acid such as acetic acid and then esterified with an organic acid having a desired structure in the presence of a sulfuric acid catalyst. Acylate can be obtained. When an organic acid anhydride is used as the acylating agent, cellulose is generally esterified using an excess amount of the organic acid anhydride relative to the amount of hydroxy groups present in the cellulose.
Cellulose acylate can also be synthesized, for example, by the method described in JP-A-10-45804.

  Further, in the cellulose ester resin layer of the present invention, other resins (for example, (meth) acrylic resin and the like) can be used in combination with the cellulose ester as long as the effects of the present invention are not impaired. The content of the other resin in the cellulose ester film is preferably 40% by mass or less, more preferably 30% by mass or less, further preferably 20% by mass or less, and further preferably 15% by mass or less in the cellulose ester film. 10 mass% or less is still more preferable.

<Formation of cellulose ester resin layer>
Next, the formation of the cellulose ester resin layer will be described.
The formation of the cellulose ester resin layer is not particularly limited. For example, the cellulose ester resin layer is preferably formed by a melt film formation method or a solution film formation method (solvent casting method). More preferably, it is formed by a membrane method (solvent cast method). Examples of film production using the solvent cast method are described in U.S. Pat. Nos. 2,336,310, 2,367,603, 2,492,078, 2,492,977, Nos. 2,492,978, 2,607,704, 2,739,069 and 2,739,070, British Patent Nos. 640731 and 736892 And JP-B Nos. 45-4554, 49-5614, JP-A-60-176834, JP-A-60-203430, JP-A-62-115035, and the like. Moreover, the said cellulose-ester resin layer may be extended | stretched. With respect to the stretching method and conditions, for example, refer to JP-A-62-115035, JP-A-4-152125, 4-284221, 4-298310, and 11-48271. can do.

(Casting)
As a method of casting the solution, a method of uniformly extruding the prepared dope from a pressure die onto a metal support, a doctor blade for adjusting the film thickness with a blade of the dope once cast on a support of metal or the like And a method using a reverse roll coater that adjusts with a reversely rotating roll, and a method using a pressure die is preferred. The pressure die includes a coat hanger type and a T die type, and any of them can be preferably used. In addition to the methods listed here, it can be carried out by various known methods for casting a cellulose ester solution, and each condition is set in consideration of differences in the boiling point of the solvent used. can do.

The cellulose ester resin layer may be a single layer or multiple layers, and in the case of multiple layers, it is preferable to use a lamination casting method such as a co-casting method, a sequential casting method, or a coating method. In particular, the simultaneous co-casting (also referred to as simultaneous multi-layer co-casting) method is particularly preferable from the viewpoint of stable production and production cost reduction.
When producing a cellulose ester resin layer by the co-casting method and the sequential casting method, first, a cellulose ester solution (also referred to as a dope) for each layer is prepared, and this solution is cast on a support.
In the co-casting method (multi-layer simultaneous casting), first, a casting dope for each layer (which may be three layers or more) is simultaneously applied from a separate slit or the like on a casting support (band or drum). The dope is extruded using a casting die that can be extruded, and the layers are cast simultaneously. It is a casting method in which after casting, the film is peeled off from the support after an appropriate time and dried to form a film. By using a co-casting die, for example, a total of three layers: a surface layer two layers formed from a surface layer dope on a casting support, and a core layer composed of a core layer dope sandwiched between these surface layers. It can be extruded and cast simultaneously on a support.

In the sequential casting method, the casting dope for the first layer is first extruded from the casting die on the casting support, cast, and dried on the second layer without drying or drying. The dope for casting is extruded from the casting die, and if necessary, the dope is cast and laminated sequentially up to the third layer or more, and peeled off from the support after a suitable time and dried. Then, a cellulose ester resin layer is formed.
In the coating method, generally, a core layer is formed into a film by a solution casting method, and a coating solution that is a target cellulose ester solution is applied to the surface layer, followed by drying to form a cellulose ester having a laminated structure. A resin layer is formed.

(Stretching)
The cellulose ester resin layer is preferably stretched after casting and drying. The stretching direction of the cellulose ester resin layer may be either the film transport direction (MD (Machine Direction) direction) or the direction orthogonal to the transport direction (TD (Transverse Direction) direction). Considering the subsequent polarizing plate processing process, the TD direction is preferable. The stretching process may be performed a plurality of times in two or more stages.

Methods for stretching in the TD direction are described in, for example, JP-A-62-115035, JP-A-4-152125, JP-A-2842211, JP-A-298310, and JP-A-11-48271. Yes. In the case of stretching in the TD direction, the film can be stretched by conveying the film while holding the film with a tenter and gradually widening the width of the tenter. Further, after the film is dried, it can be stretched using a stretching machine (preferably uniaxial stretching using a long stretching machine).
In the case of stretching in the MD direction, for example, it can be performed by adjusting the speed of the film transport roller to make the winding speed faster than the film peeling speed.

  When the laminate of the present invention is used as a protective film for a polarizer (also referred to as a polarizing plate protective film), in order to suppress light leakage when the polarizing plate is viewed obliquely, the transmission axis of the polarizer and the cellulose ester An embodiment in which slow axes in the plane of the resin layer are arranged in parallel is preferable. Since the transmission axis of the roll film-like polarizer produced continuously is generally parallel to the width direction of the roll film, it is composed of the roll film-like polarizer and the roll film-like cellulose ester resin layer. In order to continuously bond the protective film, the in-plane slow axis of the roll film-shaped protective film needs to be parallel to the width direction of the cellulose ester resin layer. Therefore, it is preferable to stretch more in the TD direction. The stretching process may be performed in the middle of the film forming process, or the original fabric that has been formed and wound may be stretched.

  The stretching in the TD direction is preferably 5 to 100%, more preferably 5 to 80%, and particularly preferably 5 to 40%. In the case of unstretched, the stretching is 0%. The stretching process may be performed in the middle of the film forming process, or the original fabric that has been formed and wound may be stretched. In the former case, the stretching may be performed in a state including the residual solvent amount, and the residual solvent amount = (residual volatile matter mass / heat-treated film mass) × 100% is stretched in a state of 0.05 to 50%. It is preferable to do. More preferably, the residual solvent is stretched 5 to 80% in a state of 0.05 to 5%.

<Additives>
The cellulose ester resin layer may contain an additive as long as the effects of the present invention are not impaired. Examples of the additive include known plasticizers, organic acids, dyes, polymers, retardation adjusting agents, ultraviolet absorbers, antioxidants, matting agents, and the like. About these, description of Paragraph Nos. 0062-0097 of JP, 2012-155287, A can be referred to, and these contents are built into this specification. Examples of the additive include a peeling accelerator, an organic acid, and a polyvalent carboxylic acid derivative. About these, the description of WO2015 / 005398 Paragraphs 0212 to 0219 can be referred to, and these contents are incorporated in the present specification. Furthermore, examples of the additive include a radical scavenger, a deterioration inhibitor, and a barbituric acid compound, which will be described later.
The content of the additive (when the cellulose ester resin layer contains two or more additives) is preferably 50 parts by mass or less with respect to 100 parts by mass of the cellulose ester. 30 parts by mass or less, more preferably 5 to 30 parts by mass.

(Plasticizer)
One preferred additive is a plasticizer. By adding a plasticizer to the cellulose ester resin layer, the hydrophobicity of the cellulose ester resin layer can be increased. This point is preferable from the viewpoint of reducing the water content of the cellulose ester resin layer. The use of such a plasticizer can reduce the occurrence of display unevenness of the image display device due to humidity when the laminate having a cellulose ester resin layer is used as a polarizing plate protective film. preferable.

  The molecular weight of the plasticizer is preferably 3000 or less, more preferably 1500 or less, and still more preferably 1000 or less, from the viewpoint of obtaining the above-described effect by adding it satisfactorily. The molecular weight of the plasticizer is, for example, 300 or more, preferably 350 or more, from the viewpoint of low volatility. In the case of multimeric plasticizers, the molecular weight is the number average molecular weight.

As the plasticizer, a polyhydric ester compound of polyhydric alcohol (hereinafter also referred to as “polyhydric alcohol ester plasticizer”), a polycondensed ester compound (hereinafter also referred to as “polycondensed ester plasticizer”), And carbohydrate compounds (hereinafter also referred to as “carbohydrate derivative plasticizers”). For polyhydric alcohol ester plasticizers, WO2015 / 005398 paragraphs 0081 to 0098, for polycondensation ester plasticizers, paragraphs 00099 to 0122, and for carbohydrate derivative plasticizers, paragraphs 0123 to 0140. The contents of which are hereby incorporated by reference. The content of these plasticizers is 1 to 20 parts by mass with respect to 100 parts by mass of the resin (cellulose ester) of the layer to which the plasticizer is added from the viewpoint of achieving both the effect of adding the plasticizer and suppressing the precipitation of the plasticizer. It is preferable to set it as 2-15 mass parts, and it is still more preferable to set it as 5-15 mass parts.
Two or more kinds of these plasticizers may be added. Also when adding 2 or more types, the specific example and preferable range of addition amount are the same as the above.

(Antioxidant)
One preferable additive may include an antioxidant. Regarding the antioxidant, the description of WO 2015/005398, paragraphs 0143 to 0165 can be referred to, and the contents thereof are incorporated in the present specification.

(Radical scavenger)
One preferred additive may include a radical scavenger. Regarding the radical scavenger, the description of WO 2015/005398 paragraphs 0166 to 0199 can be referred to, and the contents thereof are incorporated in the present specification.

(Deterioration inhibitor)
As one of preferable additives, a deterioration preventing agent can also be mentioned. Regarding the deterioration preventing agent, the description of WO 2015/005398, paragraphs 0205 to 0206 can be referred to, and the contents thereof are incorporated in the present specification.

(Barbituric acid compound)
The cellulose ester resin layer can also contain a compound having a barbituric acid structure (barbituric acid compound). A barbituric acid compound is a compound which can express various functions in a cellulose-ester resin layer by adding this compound. For example, the barbituric acid compound is effective for improving the hardness of the cellulose ester resin layer. The barbituric acid compound is also effective in improving the durability against light, heat, humidity and the like of a polarizing plate provided with a cellulose ester resin layer containing this compound. About the barbituric acid compound which can be added to the said cellulose-ester resin layer, description of the international publication 2015/005398 Paragraph 0029-0060 paragraph can be referred, for example, These contents are integrated in this-application specification.

<Saponification treatment>
The cellulose ester resin layer can be improved in adhesion to a polarizer material such as polyvinyl alcohol by alkali saponification treatment.
As the saponification method, the method described in paragraph No. 0211 and paragraph No. 0212 of JP-A-2007-86748 can be used.

  For example, the alkali saponification treatment for the cellulose ester resin layer is preferably performed in a cycle in which the film surface is immersed in an alkali solution, neutralized with an acidic solution, washed with water and dried. Examples of the alkaline solution include potassium hydroxide solution and sodium hydroxide solution. The concentration of hydroxide ions is preferably in the range of 0.1 to 5.0 mol / L, and more preferably in the range of 0.5 to 4.0 mol / L. The alkaline solution temperature is preferably in the range of room temperature to 90 ° C, more preferably in the range of 40 to 70 ° C.

  Instead of the alkali saponification treatment, easy adhesion processing as described in JP-A-6-94915 and JP-A-6-118232 may be performed.

  1-80 micrometers is preferable, as for the film thickness of the said cellulose-ester resin layer, 1-60 micrometers is more preferable, and 3-60 micrometers is more preferable. The film thickness may be 5 to 60 μm, 10 to 60 μm, 20 to 60 μm, or 30 to 60 μm.

[Manufacturing method of laminate]
The manufacturing method of the laminated body of this invention is demonstrated.
The laminated body of this invention is not specifically limited, A well-known method is employable. In addition to the melt film forming method and the solution film forming method (solvent cast method), after preparing the cellulose ester resin layer, a layer containing the polymer (S) is formed by various known coating methods, and this is dried to obtain a laminate. Can also be manufactured. Although there is no restriction | limiting in particular as said application | coating method, A micro gravure coating system can be used preferably. In any case, any coating method may be used as long as the monomer is dissolved in an appropriate solvent at an appropriate concentration. There is no particular limitation.
In addition, from the viewpoint of mass production suitability, it can be applied by a melt film forming method or a solution film forming method (solvent casting method). As the melt film forming method, a production method such as a T-die method is preferably used, and a simultaneous coextrusion method is particularly preferably used. As the solution casting method, it is preferable to use a lamination casting method such as the above-mentioned co-casting method, sequential casting method, coating method or the like. Is particularly preferable from the viewpoints of stable production and production cost reduction.

  In the laminate of the present invention, the value of the ratio of the thickness of the polymer layer (layer containing the polymer (S)) and the thickness of the cellulose ester resin layer in the laminate is [polymer layer] / [cellulose ester resin layer]. ] = 0.5 / 95.5 to 0.49 / 0.51, and more preferably [polymer layer] / [cellulose ester resin layer] = 1/99 to 20/80.

(Film thickness)
Although the film thickness of the laminated body of this invention can be suitably adjusted according to a use, it can be 5-100 micrometers, for example. When the thickness is 5 μm or more, the handling property when producing a web-like film is improved, which is preferable. Moreover, by setting it as 100 micrometers or less, it becomes easy to respond to a humidity change and it becomes easy to maintain an optical characteristic. As for the film thickness of a laminated body, 8-80 micrometers is more preferable, and 10-70 micrometers is still more preferable.

(Moisture permeability)
The moisture permeability of the laminate is measured under conditions of 40 ° C. and relative humidity 90% based on JIS Z-0208.
The moisture permeability of the laminate of the present invention is preferably 1600 g / m ² / day (24 hours) or less, more preferably 1000 g / m ² / day or less, and 600 g / m ² / day or less. More preferably, it is particularly preferably 200 g / m ² / day or less. By controlling the moisture permeability of the laminated body within the above range, the liquid crystal display device mounted with the laminated body of the present invention is warped at normal temperature, high humidity, and high temperature and high humidity, and displayed during black display. Unevenness can be suppressed.

(Moisture content)
The moisture content of the laminate (equilibrium moisture content) is 25 ° C., regardless of the film thickness, so as not to impair the adhesion with a hydrophilic thermoplastic resin such as polyvinyl alcohol when used as a protective film for a polarizing plate. The moisture content at a relative humidity of 80% is preferably 0 to 4% by mass. It is more preferably 0 to 2.5% by mass, and still more preferably 0 to 1.5% by mass. If the equilibrium moisture content is 4% by mass or less, the dependence of retardation on humidity changes does not become too large, and the display unevenness of the liquid crystal display device during black display after normal temperature, high humidity, and high temperature and high humidity environments is suppressed. This is also preferable.
The moisture content is measured by measuring a film sample 7 mm × 35 mm by a Karl Fischer method using a moisture measuring device and sample drying apparatuses “CA-03” and “VA-05” (both manufactured by Mitsubishi Chemical Corporation). Can do. The moisture content can be calculated by dividing the moisture content (g) by the sample mass (g).

[Polarizer]
The polarizing plate of the present invention includes a polarizer and at least one laminate of the present invention as a protective film for the polarizer.

  As the polarizer, for example, a film obtained by immersing and stretching a polyvinyl alcohol film in an iodine solution can be used. When using a polarizer obtained by immersing and stretching a polyvinyl alcohol film in an iodine solution, for example, the saponification surface of the cellulose ester resin layer in the laminate is bonded to at least one surface of the polarizer using an adhesive. be able to. Examples of the adhesive include an aqueous solution of polyvinyl alcohol or polyvinyl acetal (for example, polyvinyl butyral), a latex of a vinyl-based polymer (for example, polybutyl acrylate), and an ultraviolet curable adhesive. A particularly preferred adhesive is an aqueous solution of fully saponified polyvinyl alcohol.

The production method of the polarizing plate of the present invention is not particularly limited, and can be produced according to a general method. For example, there is a method in which the laminate of the present invention is subjected to an alkali treatment (saponification treatment) and bonded to both surfaces of a polarizer produced by immersing and stretching a polyvinyl alcohol film in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution. Instead of alkali treatment, easy adhesion processing as described in JP-A-6-94915 and JP-A-6-118232 may be performed. Further, the surface treatment as described above may be performed.
Especially in this invention, it is preferable to perform the said alkali treatment. That is, by hydrolyzing the alkali hydrolyzable group present on the surface of the polymer layer and exposing the hydroxy group, the adhesion between the polymer layer and the polarizer based on polyvinyl alcohol is effectively enhanced. be able to. On the other hand, since the alkali hydrolyzable group present inside the polymer layer is not hydrolyzed, the barrier performance of the polymer layer against water is not substantially impaired.
When the laminate is in a form in which the polymer layer is provided on one side of the cellulose ester resin layer, the laminate surface of the laminate with the polarizer is preferably on the polymer layer side.

The lamination of the laminate of the present invention is preferably bonded to the polarizer so that the transmission axis of the polarizer and the slow axis of the laminate of the present invention are parallel, orthogonal or 45 °. The slow axis can be measured by various known methods, for example, using a birefringence meter (KOBRADH, manufactured by Oji Scientific Instruments).
Here, parallel, orthogonal, or 45 ° includes a range of errors allowed in the technical field to which the present invention belongs. For example, it means that it is within a range of ± 10 ° from a strict angle with respect to parallel, orthogonal and 45 °, respectively, and the error from the strict angle is preferably within a range of ± 5 °, and within a range of ± 3 °. Is more preferable.
The parallel of the transmission axis of the polarizer and the slow axis of the laminate of the present invention means that the direction of the main refractive index nx of the laminate of the present invention and the direction of the transmission axis of the polarizer intersect at an angle of ± 10 °. Means that This angle is preferably within a range of ± 5 °, more preferably within a range of ± 3 °, further preferably within a range of ± 1 °, and most preferably within a range of ± 0.5 °.
Further, the orthogonality of the transmission axis of the polarizer and the slow axis of the laminate of the present invention means that the direction of the main refractive index nx of the laminate of the present invention and the direction of the transmission axis of the polarizer are 90 ° ± 10 °. It means that they intersect at an angle within the range of. This angle is preferably in the range of 90 ° ± 5 °, more preferably in the range of 90 ° ± 3 °, even more preferably in the range of 90 ° ± 1 °, most preferably 90 ° ± 0.1 °. Within range. If it is the above ranges, the fall of the polarization degree performance under polarizing plate cross Nicol will be suppressed, and light omission will be reduced and it is preferable.

  The polarizing plate is comprised with the polarizer and the protective film which protects both surfaces, and it is preferable to make at least 1 sheet of a protective film into the laminated body of this invention. Further, usually, a protective film is bonded to one surface of the polarizing plate, and a separate film is bonded to the other surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection. In this case, the protect film is bonded for the purpose of protecting the surface of the polarizing plate, and is used on the side opposite to the surface where the polarizing plate is bonded to the liquid crystal plate. Moreover, a separate film is used in order to cover the adhesive layer bonded to a liquid crystal plate, and is used for the surface side which bonds a polarizing plate to a liquid crystal plate.

<Degree of polarization>
In the polarizing plate of the present invention, the degree of polarization is preferably 95.0% or more, more preferably 98.0% or more, and most preferably 99.5% or more.

  In the present invention, the degree of polarization of the polarizing plate can be measured using an automatic polarizing film measuring device VAP-7070 manufactured by JASCO Corporation. More specifically, a polarization degree spectrum is calculated from the orthogonal transmittance and parallel transmittance measured at a wavelength of 380 nm to 700 nm by the following formula, and a weighted average of the light source (auxiliary illuminant C) and CIE visibility (Y) is calculated. Can be obtained.

Polarization degree (%)
= {(Parallel transmittance−Orthogonal transmittance) / (Parallel transmittance + Orthogonal transmittance)} ^1/2 × 100

<Change in polarization degree>
The polarizing plate of the present invention is excellent in durability under wet heat aging conditions. For this reason, the amount of change in the degree of polarization before and after the polarizing plate durability test described later is small.
The polarizing plate of the present invention measures orthogonal transmittance and parallel transmittance using an automatic polarizing film measuring device VAP-7070 manufactured by JASCO Corporation, and calculates the degree of polarization according to the above formula. It is preferable that the amount of change in polarization degree is less than 5% when stored in an environment of 85% humidity for 500 hours.

<Other characteristics>
Other preferable optical characteristics and the like of the polarizing plate of the present invention are described in paragraph numbers 0238 to 0255 of JP-A-2007-086748, and it is preferable to satisfy these characteristics.

[Image display device]
The polarizing plate of the present invention is preferably used for an image display device. Examples of such an image display device include a liquid crystal display device and an organic electroluminescence display device. When used for an organic electroluminescence display device, for example, it is used for antireflection applications. Especially, the polarizing plate of this invention is used suitably for a liquid crystal display device.
<Liquid crystal display device>
The liquid crystal display device which is one embodiment as the image display device of the present invention includes a liquid crystal cell and the polarizing plate of the present invention disposed in at least one of the liquid crystal cells.

A preferred embodiment of the liquid crystal display device will be described.
FIG. 2 is a schematic view showing an embodiment of the liquid crystal display device. In FIG. 2, the liquid crystal display device 20 includes a liquid crystal cell having a liquid crystal layer 24 and a liquid crystal cell upper electrode substrate 23 and a liquid crystal cell lower electrode substrate 25 disposed above and below, and upper polarizing plates disposed on both sides of the liquid crystal cell. 21 and the lower polarizing plate 26. A color filter may be disposed between the liquid crystal cell and each polarizing plate. When the liquid crystal display device 20 is used as a transmission type, a cold cathode or hot cathode fluorescent tube, or a backlight having a light emitting diode, field emission element, or electroluminescent element as a light source is disposed on the back surface. The substrate of the liquid crystal cell generally has a thickness of 50 μm to 2 mm.

The upper polarizing plate 21 and the lower polarizing plate 26 usually have a configuration in which a polarizer is sandwiched between two polarizing plate protective films. In the liquid crystal display device 20 of the present invention, it is preferable that at least one polarizing plate is the polarizing plate of the present invention. The polarizing plates 21 and 26 included in the liquid crystal display device 20 of the present invention are the laminate of the present invention as a polarizing plate protective film, a polarizer, and a general transparent protective film in order from the outside of the device (the side far from the liquid crystal cell). A form in which each layer is laminated in order is preferable. Moreover, it replaces with the said general transparent protective film, and the form which used the laminated board of this invention as a phase difference film is also preferable.
The substrate of the liquid crystal cell generally has a thickness of 50 μm to 2 mm.

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

  The present invention will be described in more detail based on examples, but the present invention is not limited to the following examples.

[Synthesis example]
<Synthesis Example 1: Synthesis of Polymer P-1>
In a 1 L three-necked flask equipped with a thermometer, stirring blades, and reflux ring, 75.0 g of methyl ethyl ketone was charged and stirred at 75 ° C. under a nitrogen stream. Separately, 90 g of γ-butyrolactone methacrylate (GBLMA, manufactured by Osaka Organic Chemical Industry), 0.08 g of polymerization initiator (manufactured by Wako Pure Chemical Industries), and 75.0 g of methyl ethyl ketone were weighed and mixed and dissolved in a 300 mL Erlenmeyer flask. To prepare a monomer solution.
Next, the monomer solution was dropped into methyl ethyl ketone stirred at 75 ° C. at a rate of 1.2 mL / min. A chemical pump was used for dripping. The reaction solution after completion of the dropwise addition is further reacted at 75 ° C. for 6 hours. After the reaction, the reaction solution is allowed to cool to room temperature, diluted with 200 mL of methyl ethyl ketone, and reprecipitated in an aqueous solution of 5 L of water / 0.3 L of methanol. A white precipitate was obtained. After filtering off the obtained white precipitate, washing with 2 L of water was repeated three times, followed by drying at 40 ° C. for 24 hours to obtain 70 g of the following polymer P-1. In addition, the number attached | subjected to the repeating unit of the polymer in a present Example shows mol% of the repeating unit which exists in a polymer.

<Synthesis Examples 2-8: Synthesis of Polymers P-2 to P-8>
In the said synthesis example 1, the monomer seed | species to be used was changed into the monomer which introduce | transduces the following repeating unit, and it carried out similarly to the synthesis example 1, and obtained polymer P-2-P-8.

<Comparative Synthesis Example 1: Synthesis of Comparative Polymer HP-1>
In the said synthesis example 1, the monomer seed | species to be used was changed into the monomer which introduce | transduces the following repeating unit, and it carried out similarly to the synthesis example 1, and obtained comparative polymer HP-1.

Table 1 below also shows the weight average molecular weight of the polymer and the molar amount (mol / g) of the alkali hydrolyzable group in 1 g of the polymer.
The molar amount of the alkali hydrolyzable group in the polymer obtained in each of the above synthesis examples and comparative synthesis examples was determined by ¹ H NMR measurement using a nuclear magnetic resonance spectrum measuring apparatus (NMR300 MHz) manufactured by BRUKER.
As the weight average molecular weight of the polymer, a weight average molecular weight measured in terms of polystyrene by gel permeation chromatography (GPC) was adopted. Specific measurement conditions are shown below.
GPC device: GPC device manufactured by Tosoh Corporation (HLC-8320GPC, Ecosec)
Column: TSK gel SuperHZM-H, TSK gel SuperHZ4000, TSK gel SuperHZ2000 combined use (made by Tosoh, 4.6 mm ID (inner diameter) x 15.0 cm)
Eluent: Tetrahydrofuran (THF)

[Production Example 1: Production of laminates S-1 to S-8, comparative laminate HS-1 and single layer CS-2]
<Preparation of Cellulose Ester Resin Layer CA-1>
The following composition was put into a mixing tank, stirred while heating to dissolve each component, and a cellulose acetate solution (dope A) having a solid content concentration of 22% by mass was prepared.
[Composition of Cellulose Acetate Solution (Dope A)]
Cellulose acetate with an acetyl substitution degree of 2.86 100 parts by weight Triphenyl phosphate (plasticizer) 7.8 parts by weight Biphenyl diphenyl phosphate (plasticizer) 3.9 parts by weight Ultraviolet absorber (Tinubin 328 manufactured by Ciba Japan) 0.9 Part by weight Ultraviolet absorber (manufactured by Tinuvin 326 Ciba Japan) 0.2 part by weight Methylene chloride (first solvent) 336 parts by weight Methanol (second solvent) 29 parts by weight 1-butanol (third solvent) 11 parts by weight

  Using the band casting apparatus, the prepared dope was uniformly cast from a casting die onto a stainless steel endless band (casting support) having a width of 2000 mm. When the amount of residual solvent in the dope reaches 40% by mass, it is peeled off from the casting support as a polymer film, conveyed without being actively stretched by a tenter, and dried at 130 ° C. in a drying zone. It was. The thickness of the obtained cellulose ester resin layer (cellulose ester film) CA-1 was 55 μm.

<Preparation of cellulose ester resin layer CA-2>
Cellulose ester resin layer (cellulose ester film) CA-2 (thickness: 60 μm) was obtained in the same manner as in the preparation of CA-1.

<Preparation of laminated body S-1>
The polymer P-1 was mixed with methyl ethyl ketone so as to have a solid content of 15%, charged into a glass separable flask equipped with a stirrer, stirred at room temperature for 5 hours, and filtered through a polypropylene depth filter having a pore size of 5 μm. A composition for forming a polymer layer was obtained. Next, the composition for forming a polymer layer was applied on the cellulose ester resin layer CA-1 prepared by the above-described procedure using a gravure coater. Subsequently, it dried at 25 degreeC for 1 minute, and also dried at 120 degreeC for about 5 minutes, and obtained the laminated body S-1 with a film thickness of 60 micrometers.

<Preparation of laminated bodies S-2 to S-8 and comparative laminated body HS-1>
In the above <Preparation of laminate S-1>, the polymer P-1 used for the polymer layer forming composition was changed as shown in Table 2 below, and the cellulose ester resin layer was changed as shown in Table 2 below. Produced the laminated bodies S-2 to S-8 and the comparative laminated body HS-1 in the same manner as in <Preparation of the laminated body S-1>. Each of the obtained laminates had a thickness of 60 μm.

[Test Example 1: Interlayer adhesion test of laminate]
For the interlaminar adhesion of the laminate, a cross cut test according to JIS K 5400 was applied. The specific procedure is shown below.
Using a cutter knife and a cutter guide, 11 cuts with an interval of 1 mm were made on the polymer layer side surface of each laminate prepared above to prepare 100 grids (this is defined as 100%). After the cellophane tape was strongly pressure-bonded on the grid, the end of the tape was peeled off at an angle of 45 °, and the state of the grid (the state of peeling of the lattice constituting the grid) was observed. The observation results were evaluated by applying the following evaluation criteria.

A: No lattices are peeled off B: Peeling of lattices is less than 5% C: Peeling of lattices is 5% or more The results are shown in Table 2 below.

[Test Example 2: Evaluation of moisture permeability of laminated body (moisture permeability at 40 ° C. and 90% relative humidity)]
For the water vapor transmission rate, the measurement of vapor permeation (mass method, thermometer method, vapor pressure method, adsorption amount method) is applied. ,evaluated. The specific procedure is shown below.
According to the method of JIS Z-0208, each laminated body produced above was cut, and this cut laminated body was attached to a moisture permeable cup to obtain a test sample. This test sample was conditioned for 24 hours under conditions of a temperature of 40 ° C. and a relative humidity of 90%.
The weight of the test sample before and after humidity conditioning is weighed, the mass of the test sample before humidity conditioning is A, and the mass of the sample after tempering is B. Calculated.
Δm = | A−B |
Subsequently, the above Δm was converted to a value per 1 m ² of the sample area and used as moisture permeability (g / (m ² × day)). The moisture permeability of each obtained laminate was evaluated according to the following evaluation criteria.

A +: moisture permeability is less than 500 g / (m ² × day) A: moisture permeability is 500 g / (m ² × day) or more and less than 1000 g / (m ² × day) B: moisture permeability is 1000 g / (m ² × day) or more and less than 1600 g / (m ² × day) C: Moisture permeability is 1600 g / (m ² × day) or more The results are shown in Table 2 below.

  From the results shown in Table 2, it can be seen that the laminate of the present invention has excellent interlayer adhesion and low moisture permeability.

[Production Example 2: Production of polarizing plates PL-1 to PL-8 and comparative polarizing plates HPL-1 and HPL-2]
Polarizer plates PL-1 to PL-8 and comparative polarizer plates HPL-1 and HPL-2 were produced as described below.
(1) Saponification Commercially available cellulose acylate film (Fujitack ZRD40, manufactured by FUJIFILM Corporation) and each of the laminates S-1 to S-8, HS-1 and cellulose ester monolayer film CA- produced above. 2 was immersed in a 1.5 mol / L NaOH aqueous solution (saponification solution) maintained at 55 ° C. for 2 minutes, and then the ZRD 40 and each laminate were washed with water. Next, after the ZRD 40 and each laminate were immersed in a 0.05 mol / L sulfuric acid aqueous solution at 25 ° C. for 30 seconds, the washing bath was further passed under running water for 30 seconds to bring the ZRD 40 and each laminate to a neutral state. did. The obtained ZRD40 and each laminate were repeatedly drained with an air knife three times, and after dropping water, they were retained in a drying zone at 70 ° C. for 15 seconds, dried, and saponified ZRD40, each laminate and cellulose ester. Single layer film CA-2 was obtained.

(2) Production of Polarizer According to Example 1 of Japanese Patent Application Laid-Open No. 2001-141926, iodine was adsorbed to a stretched polyvinyl alcohol film to produce a polarizer having a thickness of 27 μm.

(3) Bonding Each laminated body after the saponification (the polymer layer surface of each laminated body is arranged so as to be in contact with the polarizer) or cellulose ester single layer film CA-2, the polarizer produced above, The cellulose acylate film ZRD40 after saponification of the above was laminated with a PVA adhesive in this order and thermally dried to obtain polarizing plates PL-1 to PL-8, comparative polarizing plates HPL-1 and HPL-2. Produced.
Under the present circumstances, it arrange | positioned so that the longitudinal direction of the roll of the produced polarizer and the longitudinal direction of the roll of the cellulose-ester resin layer of each laminated body may become parallel. Moreover, it arrange | positioned so that the longitudinal direction of the roll of a polarizer and the longitudinal direction of the roll of the said cell roll acylate film ZRD40 may become parallel.

[Test Example 3: Evaluation of adhesion between protective film and polarizer]
In the polarizing plate produced above, the adhesion between the laminate (protective film) and the polarizer was evaluated as follows.
The polarizing plate is cut into a size of 200 mm parallel to the stretching direction of the polarizer and 15 mm in the orthogonal direction. After cutting with a cutter knife between the laminate and the polarizer, the cellulose ester resin layer surface of the laminate is removed. Laminated with glass plate. Using the Tensilon universal testing machine RTG series (manufactured by A & D Co., Ltd.), the laminate and the polarizer were peeled at a peel rate of 3000 mm / min in the 90-degree direction, and the peel strength (unit: N (Newton)) ) Was measured. A similar test was performed on five polarizing plates, and the arithmetic average value of the obtained peel strengths was applied to the following evaluation criteria to evaluate adhesion. The larger the measured value, the greater the force required for peeling, that is, the better the adhesion.
<Evaluation criteria for adhesion between protective film and polarizer>
A: Peel strength is 3N or more B: Peel strength is 2N or more and less than 3N C: Peel strength is less than 2N

[Test Example 4: Evaluation of polarizer durability of polarizing plate]
The durability of the polarizing plate was measured by measuring the orthogonal transmittance and the polarization degree in the following manner in a form in which the polarizing plate was attached to glass through an adhesive.
On the glass plate, the polarizing plate prepared above is made so that the S-1 to S-8, HS-1 and CA-2 sides are on the air interface side (so as to be on the side away from the glass plate). Two pasted samples (about 5 cm × 5 cm) were prepared. About these samples, the glass plate side was set toward the light source, and the degree of polarization was measured. Each of the two samples was measured and the arithmetic average value was taken as the polarization degree of the polarizing plate.
The degree of polarization was calculated by the following formula.

Polarization degree (%) = [(parallel transmittance−orthogonal transmittance) / (orthogonal transmittance + parallel transmittance)] ^1/2 × 100

The degree of polarization was measured in the range of 380 nm to 780 nm using an automatic polarizing film measuring device VAP-7070 manufactured by JASCO Corporation, and the measured value at a wavelength of 410 nm at which the degree of deterioration is more noticeable than other wavelengths was adopted. .
Thereafter, it was stored for 500 hours in an environment of a temperature of 85 ° C. and a relative humidity of 85%. Subsequently, the polarization degree was measured about two samples like the above, the measured value of two samples was arithmetically averaged, and it was set as the polarization degree of the polarizing plate after a preservation | save. Based on the amount of change in the degree of polarization before and after storage, the polarizing plate durability was evaluated based on the following evaluation criteria.
Here, the amount of change in polarization degree is calculated by the following equation.

  Polarization degree change (%) = [Polarization degree after storage (%)] − [Polarization degree before storage (%)]

<Polarizer durability evaluation criteria>
Polarization degree change (%)
A +: Polarization degree change amount is less than 0.05% A: Polarization degree change amount is 0.05% or more and less than 2.0% B: Polarization degree change amount is 2.0% or more and less than 3.0% C: Polarization degree The amount of change is 3.0% or more. The results are shown in Table 3 below.

  From the results shown in Table 3, it can be seen that the polarizing plate of the present invention is excellent in the adhesion between the protective film and the polarizer and is excellent in the protective action of the polarizer.

10 Laminate (laminate)
DESCRIPTION OF SYMBOLS 11 Cellulose ester resin layer 12 Polymer layer 20 Liquid crystal display device 21 Upper polarizing plate 22 Upper polarizing plate absorption axis direction 23 Liquid crystal cell upper electrode substrate 24 Liquid crystal layer 25 Liquid crystal cell lower electrode substrate 26 Lower polarizing plate 27 Lower polarizing plate absorption Axial direction

Claims (7)

  A laminate comprising a cellulose ester resin layer and a layer containing a polymer having an alkali hydrolyzable group in contact with the cellulose ester resin layer. The laminate according to claim 1, wherein the alkali hydrolyzable group is represented by any one of the following general formulas (1) to (7).

In general formula (1), A represents a single bond or a divalent group. Z represents a group selected from the following general formulas LC-1 to LC-17. * Indicates a linking site.

In General Formulas LC-1 to LC-17, R ² represents a substituent. ** indicates the site of connection with A. n is an integer of 0-4.

In the general formula ^(2), R a ~R ^d represents a hydrogen atom or an alkyl group. ^Re represents an alkyl group. * Indicates a linking site.

In General Formula (3), L ¹ represents a single bond or a divalent group. n ¹ is 1 or 2. * Indicates a linking site.

In the general formula ^(4), R f ~R ⁱ represents a hydrogen atom, an alkyl group or a halogen atom. X represents an electron withdrawing group. * Indicates a linking site.

In General Formula (5), L ² represents a single bond or a divalent group. Z ^a represents a group represented by the general formula (5a) or (5b). * Indicates a linking site.
In general formula (5a), R ^j , R ^k and R ^m represent a hydrogen atom or an alkyl group. *** indicates the linking site and ^{L 2.}
In the general formula ^{(5b), R p, R} q, R r, R s and ^{R t} represents a hydrogen atom or an alkyl group. *** indicates the linking site and ^{L 2.}

In General Formula (6), L ³ represents a single bond or a divalent group. R ^u represents an alkyl group. * Indicates a linking site.

In General Formula (7), L ⁴ represents a single bond or a divalent group. R ^v represents an alkyl group. * Indicates a linking site.   The laminated body of Claim 1 or 2 whose content of the said alkali hydrolysable group is 0.00001-0.02 mol / g in the said polymer. The laminate according to any one of claims 1 to 3, wherein the polymer having an alkali hydrolyzable group has a repeating unit represented by the following general formula (1a).

In the general formula (1a), R ^A represents a hydrogen atom, a halogen atom or an alkyl group.
R ^B and R ^C represent a hydrogen atom, an alkyl group, an aryl group or an alkoxycarbonyl group.
L ^A is a single bond, or a divalent group selected from an alkylene group, an arylene group, —C (═O) —, —O—, and —NR ^D —, or a combination of two or more of these groups. And a divalent linking group. R ^D represents a hydrogen atom or a substituent.
* 1 represents an alkali hydrolyzable group represented by any one of the above general formulas (1) to (7). The laminate according to any one of claims 1 to 4, wherein the polymer having an alkali hydrolyzable group has a repeating unit represented by the following general formula (1b).

In general formula (1b), A and Z have the same meanings as A and Z in general formula (1), respectively. R ^A1 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms.   The polarizing plate which has the laminated body of any one of Claims 1-5, and a polarizer.   An image display device comprising the polarizing plate according to claim 6.

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