WO2017057256A1

WO2017057256A1 - Laminate, polarizing plate, and image display device

Info

Publication number: WO2017057256A1
Application number: PCT/JP2016/078233
Authority: WO
Inventors: 寛野副; 佑起中沢; 一洋雨宮
Original assignee: 富士フイルム株式会社
Priority date: 2015-09-30
Filing date: 2016-09-26
Publication date: 2017-04-06

Abstract

A laminate, a polarizing plate using this laminate, and an image display device. The laminate has a layer containing a cellulose ester and a layer containing an adhesive polymer. The layer containing the adhesive polymer is adjacent to at least one surface of the layer containing the cellulose ester. The adhesive polymer has a repeating unit [a] and a repeating unit [b]. [a]: A repeating unit derived from a specific compound, e.g., a styrene compound, and having a solubility parameter δ t of 13.5-19.5. [b] A repeating unit derived from a specific compound, e.g., an ester acrylate compound, and having a solubility parameter δ t of 20.0-26.0.

Description

Laminated body, polarizing plate, and image display device

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

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 apparatus is partly caused by moisture 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 addition, such a decrease in image quality becomes more apparent when used in harsh environments such as outdoor applications.

As the protective film, acrylic polymers, styrenes, vinyl esters, maleic anhydrides, copolymers thereof, or cellulose polymers are widely used from the viewpoint of versatility and processability. Due to the necessity of further improving the durability, the optical film is being modified (for example, Patent Documents 1 to 3).

JP-A-9-197128 JP 2012-172062 A JP 2013-101281 A

As a result of repeated investigations from the viewpoint of suppressing the deterioration of the polarizer, the inventors of the present invention, including the films described in the above-mentioned patent documents, when the film is highly thinned to the above-described required level, It has been found that it is difficult to sufficiently suppress the deterioration of the polarizer under high temperature and high humidity conditions. As a result of continuous examination on this point, the present inventors have found a correlation between the moisture content of the protective film and the deterioration of the polarizing plate.
Furthermore, when a conventional protective film having a laminated structure or a laminate using a conventional protective film is exposed to a high temperature and high humidity condition for a long time, the layers of the laminate are peeled off, resulting in durability. I found it was not enough.

An object of the present invention is to provide a laminate having a low moisture content and excellent durability, a polarizing plate using the laminate, and an image display device.

As a result of intensive studies in view of the above problems, the present inventors have found that a polymer having a repeating unit having a specific structure with a solubility parameter within a specific range and a repeating unit having a specific structure with a different solubility parameter from the repeating unit. A laminate comprising a layer containing a cellulose ester on a layer containing a cellulose ester has a low moisture content and excellent interlayer adhesion between the layer containing the polymer and the layer containing the cellulose ester, It has been found that deterioration of the polarizer can be effectively suppressed even under high temperature and high humidity conditions by using it as a protective film for the polarizer. The present invention has been further studied and completed based on these findings.

The above-described problems of the present invention have been solved by the following means.
<1> A laminate having a layer containing a cellulose ester and a layer containing an adhesive polymer,
The layer containing the adhesive polymer is adjacent to at least one side of the layer containing the cellulose ester;
The adhesive polymer has at least one repeating unit of the following [a] and at least one repeating unit of the following [b].
Laminated body.
[A]: A repeating unit derived from a styrene compound, a terpene compound, a C5 fraction compound or a C9 fraction compound, and having a solubility parameter δt calculated by the Hoy method of 13.5 to 19.5 [B]: A repeating unit derived from an acrylate compound, a (meth) acrylic compound, a (meth) acrylamide compound, a vinyl acetate compound, a vinyl ketone compound, a maleic anhydride compound or a styrene compound, or an ethylenic group other than these repeating units A repeating unit derived from a compound having a saturated bond, and having a solubility parameter δt calculated by the Hoy method of 20.0 to 26.0

<2> The laminate according to <1>, wherein the adhesive polymer has a repeating unit represented by the following general formula 1 as a repeating unit of [a].

In general formula 1, R ¹ , R ² and R ³ each independently represent a hydrogen atom, a halogen atom, an alkyl group or an aryl group.
R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an acyl group, an acyloxy group or an alkoxycarbonyl group. To express.

<3> The laminate according to <1> or <2>, wherein the adhesive polymer has a repeating unit represented by the following general formula 2 as the repeating unit of [b].

In General Formula 2, R ⁴ represents a hydrogen atom or an alkyl group.
R ⁵ and R ⁶ each independently represents a hydrogen atom, an alkyl group, an aryl group or an alkoxycarbonyl group.
L is a single bond, an alkylene group, an arylene group, a divalent linking group selected from —C (═O) —, —O— and —N (R ⁷ ) —, or two or more of these linking groups. The bivalent coupling group which combines these is shown. R ⁷ represents a hydrogen atom or an alkyl group.

<4> Any one of <1> to <3>, wherein the molar amount of the repeating unit [b] in the total molar amount of the repeating units constituting the adhesive polymer is 5 mol% or more and 95 mol% or less. The laminated body as described in.

<5> The laminate according to any one of <1> to <4>, wherein the adhesive polymer has a repeating unit represented by the following general formula 1-1 as the repeating unit of [a].

In general formula 1-1, R ⁸ represents a hydrogen atom, an alkyl group or an aryl group.
R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁵ each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an acyl group, an acyloxy group or an alkoxycarbonyl group. To express.

<6> The laminate according to any one of <1> to <5>, wherein the adhesive polymer has a repeating unit represented by the following general formula 2-1 as a repeating unit of [b].

In general formula 2-1, R ⁹ represents a hydrogen atom or an alkyl group.
L is a single bond, an alkylene group, an arylene group, a divalent linking group selected from —C (═O) —, —O— and —N (R ¹⁰ ) —, or two or more of these linking groups. The bivalent coupling group which combines these is shown. R ¹⁰ represents a hydrogen atom or an alkyl group.

<7> The laminate according to any one of <1> to <6>, wherein the cellulose ester is cellulose acylate.
<8> A polarizing plate comprising the laminate according to any one of <1> to <7> above and a polarizer.
<9> An image display device having the polarizing plate according to <8>.

The laminate of the present invention has a low moisture content, is excellent in interlayer adhesion, and can prevent delamination under high temperature and high humidity conditions. The laminate of the present invention can effectively suppress deterioration of the polarizer under high temperature and high humidity conditions by being superimposed on the polarizer.
Moreover, the polarizing plate and the image display device of the present invention can effectively prevent deterioration of the polarizer even under high temperature and high humidity conditions by using the laminate exhibiting the above excellent effects, and have high durability. Show.
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”.
The above and other features and advantages of the present invention will become more apparent from the following description, with reference where appropriate to the accompanying drawings.

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.

In the present specification, the numerical 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, etc. (hereinafter referred to as substituents, etc.) indicated by specific symbols, or when a plurality of substituents etc. 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 other than a 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 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 synonymous with a compound or repeating unit in which substitution or non-substitution is not specified.
Further, in the present specification, when simply referred to as “substituent”, a group selected from the following substituent group T may be mentioned 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 has a further substituent, it means the total number of carbon atoms including this substituent.
In this specification, when a certain group can adopt a non-cyclic skeleton and a cyclic skeleton, unless otherwise specified, the certain group includes a non-cyclic skeleton group and a cyclic skeleton group. For example, the alkyl group includes a linear alkyl group, a branched alkyl group, and a cyclic (cyclo) alkyl group. When a certain group takes a cyclic skeleton, the lower limit of the number of carbon atoms in the group of the cyclic skeleton is 3 or more, preferably 5 or more, regardless of the lower limit of the number of carbon atoms specifically described in the certain group.
In this specification, the term “(meth) acrylic acid” is used to include both methacrylic acid and acrylic acid. The same applies to “(meth) acrylamide”. In this specification, the term “acrylic acid” is used in a broader sense than usual. That is, “acrylic acid” is used to include all compounds having the structure of R ^A —C (═CR ^B ₂ ) COOH (R ^A and R ^B each independently represent a hydrogen atom or a substituent, provided that , When R ^A is methyl, means methacrylic acid). The same applies to “acrylamide”.

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, cyclopropyl, cyclopentyl, cyclohexyl group, etc.), alkenyl group (preferably having 2-20 carbon atoms, more preferably 2-12, particularly preferably 2-8). For example, vinyl group, allyl group, 2-butenyl group, 3-pentenyl group, etc.), alkynyl group (preferably having 2 to 20, more preferably 2 to 12, particularly preferably 2 to 8 carbon atoms). For example, propargyl group, 3-pentynyl group, etc.), aryl group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20, particularly preferably 6 to 12, and examples thereof include a phenyl group, a biphenyl group, and a naphthyl group.), An amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 10, and particularly preferably Is 0 to 6, for example, an amino group, a methylamino group, a dimethylamino group, a diethylamino group, a dibenzylamino group, etc.), an alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12, particularly preferably 1 to 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 preferably 6 to 12, for example, phenyloxy group, 2-naphthyloxy group, etc.), acyl group (preferably having 1 to 0, more preferably 1 to 16, particularly preferably 1 to 12, and examples include acetyl, benzoyl, formyl, and pivaloyl groups), alkoxycarbonyl groups (preferably having 2 to 20 carbon atoms, More preferably, it is 2 to 16, particularly preferably 2 to 12, and examples thereof include a methoxycarbonyl group, an ethoxycarbonyl group, etc.), an aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, more preferably 7 to 7 carbon atoms). 16, particularly preferably 7 to 10, for example, a phenyloxycarbonyl group, etc.), an acyloxy group (preferably having 2 to 20, more preferably 2 to 16, more preferably 2 to 10 carbon atoms). For example, an acetoxy group, a benzoyloxy group, etc.), an acylamino group (preferably The number of carbon atoms is 2 to 20, more preferably 2 to 16, particularly preferably 2 to 10, and examples thereof include an acetylamino group and a benzoylamino group. ), An alkoxycarbonylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 and particularly preferably 2 to 12, such as methoxycarbonylamino group), aryloxycarbonylamino group ( The number of carbon atoms is preferably 7 to 20, more preferably 7 to 16, particularly preferably 7 to 12, and examples thereof include a phenyloxycarbonylamino group, and the like, and a sulfonylamino group (preferably having 1 to 20 carbon atoms). More preferably 1 to 16, particularly preferably 1 to 12, such as methanesulfonylamino group, benzenesulfonylamino group, etc.), sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0). To 16, particularly preferably 0 to 12, such as sulfamoyl group, methyl A sulfamoyl group, a dimethylsulfamoyl group, a phenylsulfamoyl group, etc.), a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, A carbamoyl group, a methylcarbamoyl group, a diethylcarbamoyl group, a phenylcarbamoyl group, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, Methylthio group, ethylthio group, etc.), arylthio group (preferably 6-20, more preferably 6-16, particularly preferably 6-12, such as phenylthio group). A sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, Are preferably 1 to 12, for example, mesyl group, tosyl group, etc.), sulfinyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 and particularly preferably 1 to 12; For example, methanesulfinyl group, benzenesulfinyl group, etc.), urethane group, ureido group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16, particularly preferably 1 to 12, such as ureido group, Methylureido group, phenylureido group, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16, particularly preferably 1 to 12, such as diethylphosphoric acid amide, Phenyl phosphoric acid amide, etc.), hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom) Element, 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 Examples of the ring-forming hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom, and a 5-membered ring, a 6-membered ring, or a condensed ring thereof is preferable. The heterocyclic group includes an aromatic heterocyclic group and an aliphatic heterocyclic group. Specific examples include imidazolyl group, pyridyl group, quinolyl group, furyl group, piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group, and the like. ) And a silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms such as a trimethylsilyl group and a triphenylsilyl group).
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.

A preferred embodiment of the present invention will be described below.

[Laminate]
As shown in FIG. 1, a laminated body 10 as a preferred example of the present invention is laminated adjacent to at least one surface of a layer (also referred to as a cellulose ester layer) 11 containing a cellulose ester and a cellulose ester layer 11. And a layer (also referred to as an adhesive polymer layer) 12 containing an adhesive polymer.
In the present invention, “adjacent lamination” means that both layers are directly laminated without an adhesive layer (adhesive layer) or the like for adhering or adhering both layers between the cellulose ester layer and the adhesive polymer layer. (Superimposed).

If the laminated body of this invention has the said laminated structure, another structure will not be specifically limited.
For example, it may have a three-layer laminated structure in which an adhesive polymer layer is laminated adjacent to both surfaces of the cellulose ester layer. Further, two or more adhesive polymer layers having different composition ratios may be provided on the cellulose ester layer as the adhesive polymer layer. Furthermore, you may have the various functional layers specialized in the specific function on the surface of the adhesive polymer layer. 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.

The laminate of the present invention having the above structure has a low moisture content and excellent interlayer adhesion. Even if this laminated body is made into a thin film, it is possible to prevent deterioration of the polarizer under high temperature and high humidity conditions by being superimposed on the polarizer.

<Layer containing adhesive polymer>
The adhesion polymer layer which comprises the laminated body of this invention is demonstrated.
In the present invention, the “adhesive polymer layer” means a layer containing an adhesive polymer described later in an amount of 50% by mass or more. The content of the adhesive polymer in the adhesive polymer layer is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and particularly preferably 85% by mass or more. The higher the content of the adhesive polymer, the higher the adhesiveness with the cellulose ester layer, which is preferable. Therefore, the content of the adhesive polymer in the adhesive polymer layer may be 100% by mass, and is usually 99% by mass or less. When the content of the adhesive polymer in the adhesive polymer layer is not 100% by mass, the balance can contain various additives described later.
Two or more adhesive polymers may be used in combination. That is, adhesive polymers having different composition ratios and / or molecular weights may be used in combination. In this case, the total amount of the adhesive polymer is within the above range.
In the present specification, the term “adhesive polymer” simply means a polymer that can be in close contact with the cellulose ester layer, and is merely used to facilitate understanding of the present invention. The “adhesive polymer” includes all polymers having a repeating unit as defined in the present invention regardless of the degree of adhesion. That is, in judging the gist and technical scope of the present invention, the term “adhesiveness” is not considered as an invention specific matter for interpreting the present invention in a limited manner.

-Adhesive polymer-
The adhesive polymer constituting the adhesive polymer layer has at least one repeating unit of the following [a] and at least one repeating unit of the following [b] in one molecule.
[A]: A repeating unit derived from a styrene compound, a terpene compound, a C5 fraction compound or a C9 fraction compound, and having a solubility parameter δt calculated by the Hoy method of 13.5 to 19.5 [B]: Acrylic ester compound, (meth) acrylic acid compound, (meth) acrylamide compound, vinyl acetate compound, vinyl ketone compound, maleic anhydride or repeating unit derived from styrene compound, or ethylenically unsaturated other than these repeating units A repeating unit derived from a compound having a bond and having a solubility parameter δt calculated by the Hoy method of 20.0 to 26.0 In the present invention, the C5 fraction compound and the C9 fraction compound are: Resolved oil fractions obtained when pyrolyzing naphtha or gas oil, respectively Chi, compounds contained in C5 fraction, or refers to a compound included in the C9 fraction.

The solubility parameter δt is literature ^{"Properties of Polymers 3 rd, ELSEVIER} , (1990)" The δt obtained for Amorphous Polymers according to the 214-220 pages, "2) Method of Hoy (1985,1989)" column of Meaning, calculated according to the description in the above column of the above document. Units of the solubility parameter δt in the present invention are "(cal ^/ cm ^{3) 1/2."}

The repeating unit [a] is not particularly limited as long as the above [a] is satisfied.
When the repeating unit satisfying the above [a] is derived from a styrene compound, the styrene compound is not particularly limited as long as it is a repeating unit that forms a styrene polymer. Examples of the styrenic polymer include [0011] to [0020] in JP-A No. 2004-123965, [0014] to [0016] in JP-A No. 2013-75969, and [0011] in JP-A No. 7-3094. ] Etc. can be referred to.
Specific examples of the styrene compound from which the repeating unit [a] is derived include, for example, styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene. 4-chloromethylstyrene, 2,6-dimethylstyrene, 2,6-dichlorostyrene, 2,6-difluorostyrene, pentafluorostyrene, 4-ethylstyrene, 4-butylstyrene, 4-tert-butylstyrene, 4 -Methoxystyrene, 4-trifluoromethylstyrene, 4-acetoxystyrene, 4-phenylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, vinylanthracene, α-methylstyrene, β-methylstyrene, 2-methyl-1- Phenylpropene, stilbene, divinylbenzene, Examples thereof include diisopropenylbenzene, 4-isopropenyltoluene, cinnamonitrile, and 1,1-diphenylethylene.

The above-mentioned [a] repeating unit is not particularly limited as long as it is a terpene-based polymer-forming repeating unit. Examples of the terpene compound for deriving such a repeating unit include, for example, [0011] of JP-A-8-3485, [0012] to [0014] of JP-A-2007-217603, and [0008] of JP-A-2008-248215. ] Or [0017] of JP 2008-217044 A can be referred to.
Specific examples of the terpene compound include, for example, α-pinene, β-pinene, dipentene (limonene), camphene, δ3-carene, α-terpinene, γ-terpinene, terpinolene, p-cymene, myrcene or allocymene. .

The above-mentioned repeating unit [a] is not particularly limited as long as it is derived from a C5 fraction compound, as long as it is a repeating unit forming a C5 fraction polymer. Examples of the C5 fraction compound that leads to such a repeating unit include, for example, [0012] of JP-A No. 2015-166405, [0045] of JP-A No. 2014-234448 or [0017] of JP-A No. 2011-98924. [0020] and the like can be referred to.
Specific examples of the C5 fraction compound include cyclopentadiene, isoprene, pentane, piperylene and the like.

The above-mentioned [a] repeating unit is not particularly limited as long as it is a repeating unit that forms a C9-based fraction-based polymer. Examples of the C9 fraction compound that leads to such a repeating unit include [0013] of JP-A-2015-166405, [0045] of JP-A-2014-234448, and the like.
Specific examples of the C9 fraction compound include indene and dicyclopentadiene.

The adhesive polymer preferably has a repeating unit derived from a styrene compound as the repeating unit of [a].
The adhesive polymer more preferably has a repeating unit represented by the following general formula 1 as the repeating unit [a].

In general formula 1, R ¹ , R ² and R ³ each represent a hydrogen atom, a halogen atom, an alkyl group or an aryl group. R ¹ , R ² and R ³ are each preferably a hydrogen atom, a halogen atom or an alkyl group, more preferably a hydrogen atom or an alkyl group, and still more preferably a hydrogen atom.
Examples of the halogen atom that can be employed as R ¹ , R ^2, or R ³ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
The alkyl group that can be used as R ¹ , R ^2, or R ³ may be linear, branched, or cyclic. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and still more preferably 1 to 3 carbon atoms. The alkyl group is more preferably methyl or ethyl, and still more preferably methyl.
The aryl group that can be adopted as R ¹ , R ^2, or R ³ 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.

R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ each represent a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an acyl group, an acyloxy group or an alkoxycarbonyl group. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ are each preferably a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an acyloxy group or an alkoxy group, more preferably a hydrogen atom, a halogen atom or an alkyl group. Preferably, a hydrogen atom is more preferable.

Examples of the halogen atom that can be adopted as R ¹¹ , R ¹² , R ¹³ , R ¹⁴ or R ¹⁵ include a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and a fluorine atom or a chlorine atom is preferable.
The alkyl group which can be taken as R ¹¹ , R ¹² , R ¹³ , R ¹⁴ or R ¹⁵ may be linear, branched or cyclic. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and still more preferably 1 to 3 carbon atoms. The alkyl group is more preferably methyl, ethyl or butyl, and still more preferably methyl.
The alkenyl group which can be adopted as R ¹¹ , R ¹² , R ¹³ , R ¹⁴ or R ¹⁵ may be linear, branched or cyclic. The alkenyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still more preferably 2 or 3. The alkenyl group is more preferably ethenyl or propenyl, and even more preferably ethenyl.

The aryl group that can be adopted as R ¹¹ , R ¹² , R ¹³ , R ¹⁴ or R ¹⁵ has preferably 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, particularly preferably 6 to 12 carbon atoms, and particularly preferably phenyl.

The alkoxy group which can be taken as R ¹¹ , R ¹² , R ¹³ , R ¹⁴ or R ¹⁵ may be linear, branched or cyclic. The alkoxy group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and still more preferably 1 to 3 carbon atoms. The alkoxy group is more preferably methoxy or ethoxy.
The acyl group, acyloxy group or alkoxycarbonyl group which can be taken as R ¹¹ , R ¹² , R ¹³ , R ¹⁴ or R ^{15 is the same} as the corresponding group in the substituent group T, and the preferred ones are also the same. is there.

Two adjacent groups out of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ may be bonded to each other to form a ring. For example, two adjacent ethenyl groups may be bonded to each other to form a benzene ring (a naphthalene ring as a whole) including the carbon atom to which they are bonded.
R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ may each further have a substituent selected from the substituent group T described above. For example, the alkyl group which has a substituent is mentioned, Specifically, a trifluoromethyl group is mentioned.

The adhesive polymer further preferably has a repeating unit represented by the following general formula 1-1 as the repeating unit of the above [a].

In General Formula 1-1, R ⁸ represents a hydrogen atom, an alkyl group, or an aryl group. R ⁸ is preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom.
The alkyl group and aryl group that can be taken as R ^{8 have the same} meanings as the alkyl group and aryl group that can be taken as R ¹ , respectively, and the preferred ones are also the same.
R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁵ each represent a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an acyl group, an acyloxy group or an alkoxycarbonyl group.
R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁵ are respectively synonymous with R ¹¹ , R ¹² , R ¹³ , R ^{14 and} R ^{15 in the} general formula 1, and preferred ones are also the same.

Preferred examples of the repeating unit [a] are shown below as structural formulas, but the present invention is not limited to these specific examples.
In the following specific examples, A-1 to A-19 and A-37 are repeating units derived from a styrene compound, A-20 to A-23 are repeating units derived from a C5 fraction compound, and A-24 to A-28 is a repeating unit derived from a terpene compound, and A-29 to A-36 are repeating units derived from a C9 fraction compound.

The repeating unit [b] is not particularly limited as long as the above [b] is satisfied.
The repeating unit satisfying the above [b] is not particularly limited as long as it is a (meth) acrylic acid ester compound-derived repeating unit that forms a (meth) acrylic acid ester polymer. As the structure of such a repeating unit, for example, paragraphs [0021] to [0023] in JP-A No. 2004-323770 or [0024] to [0059] in JP-A No. 2014-185196 can be referred to.
Specific examples of the (meth) acrylic acid ester compound for deriving the repeating unit [b] include, for example, 2-hydroxyethyl acrylate, 2-acetoacetoxyethyl acrylate, 2-isocyanatoethyl acrylate, and methacrylic acid. Examples thereof include 2-hydroxyethyl, 2-dimethylaminoethyl methacrylate, 2-diethylaminoethyl methacrylate, and 2-isocyanatoethyl methacrylate.

The repeating unit [b] is not particularly limited as long as it is a (meth) acrylic acid compound-derived repeating unit that forms a (meth) acrylic acid polymer. As the structure of such a repeating unit, for example, paragraphs [0020] to [0027] of JP-A No. 2002-212221 can be referred to.
Specific examples of the (meth) acrylic acid compound from which the repeating unit [b] is derived include acrylic acid and its metal salt, and methacrylic acid and its metal salt.

The repeating unit [b] is not particularly limited as long as it is a (meth) acrylamide compound-derived repeating unit that forms a (meth) acrylic acid polymer. The preferred structure of the compound leading to such a repeating unit is as shown in the structural formulas exemplified later.

The repeating unit of [b] is not particularly limited as long as it is a vinyl acetate compound-derived repeating unit that forms a vinyl acetate polymer. As the structure of such a repeating unit, for example, paragraphs [0007] to [0008] of JP-A-2002-338609 can be referred to.
Specific examples of the vinyl acetate compound from which the repeating unit [b] is derived include vinyl acetate, vinyl propionate, vinyl pivalate, isopropenyl acetate and the like. Thus, in the present invention, “vinyl acetate compound” is used to include a compound in which a hydrogen atom of vinyl acetate is substituted.

The repeating unit [b] is not particularly limited as long as it is a vinyl ketone compound-derived repeating unit that forms a vinyl ketone polymer. As the structure of such a repeating unit, for example, paragraphs [0010] to [0017] of JP-A-2007-230940 or paragraphs [0009] to [0011] of JP-A-7-291886 can be referred to.
Specific examples of the vinyl ketone compound for deriving the repeating unit [b] include methyl vinyl ketone, ethyl vinyl ketone, isopropenyl methyl ketone and the like.

The above-mentioned repeating unit [b] derived from a maleic anhydride compound is not particularly limited as long as it is a repeating unit forming a maleic anhydride polymer. As the structure of such a repeating unit, for example, paragraphs [0027] to [0029] of JP-A-2006-1111710, paragraphs [0013] to [0015] of JP-A-2008-156400, and the like can be referred to.
Specific examples of the maleic anhydride compound from which the repeating unit [b] is derived include maleic anhydride, N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide and maleic acid. Thus, in the present invention, “maleic anhydride compound” is used to include a compound derived from maleic anhydride.

A preferable structure when the repeating unit [b] is derived from a styrene compound is as shown in the structural formula exemplified later.

The repeating unit [b] may be a repeating unit derived from a compound having an ethylenically unsaturated bond (carbon-carbon double bond) other than the repeating unit derived from each compound described above.

It is more preferable that the adhesive polymer has a repeating unit represented by the following general formula 2 as the repeating unit [b].

In General Formula 2, R ⁴ represents a hydrogen atom or an alkyl group. The alkyl group which can be taken as R ⁴ has the same meaning as R ¹ in the general formula 1, and the preferred one is also the same.
R ⁵ and R ⁶ each independently represents a hydrogen atom, an alkyl group, an aryl group or an alkoxycarbonyl group. R ⁵ and R ⁶ are each preferably a hydrogen atom.
The alkyl group and aryl group which can be taken as R ⁵ and R ⁶ are respectively synonymous with the alkyl group and aryl group which can be taken as R ² in the general formula 1, and the preferred ones are also the same.
The alkoxycarbonyl group which can be taken as R ⁵ and R ⁶ has the same meaning as the alkoxycarbonyl group in the substituent group T, and preferred ones are also the same.

L is a single bond, a divalent linking group selected from an alkylene group, an arylene group, —C (═O) —, —O— and —N (R ⁷ ) —, or a linking group thereof. A divalent linking group formed by combining two or more types is shown. R ⁷ represents a hydrogen atom or an alkyl group, and has the same meaning as R ¹ described above, and preferred ones are also the same.
The alkylene group that can be taken as L is preferably linear. The alkylene group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, more preferably 1 to 3, and particularly preferably 2.
The arylene group that can be taken as L 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.
The alkylene group and the arylene group that can be taken as L may each have a substituent. Examples of the substituent include the groups in the substituent group T described above.

In the divalent linking group formed by combining two or more linking groups, the number of the linking groups to be combined is not particularly limited, but is preferably 2 to 9, for example, and more preferably 2 or 3. The combination of the linking groups is not particularly limited, and for example, a combination of —C (═O) — and —O— or a combination including —C (═O) — and —O— is preferable. The combination including —C (═O) — and —O— includes a combination of —C (═O) —, —O— and an alkylene group, or —C (═O) —, —O— and an arylene group. The combination of —C (═O) —, —O— and an alkylene group is preferable. Among these, it is preferable that L is a linking group containing —C (═O) —, and —C (═O) — is bonded to the main chain (carbon atom to which R ⁴ is bonded).

The adhesive polymer further preferably has a repeating unit represented by the following general formula 2-1 as the repeating unit [b].

In general formula 2-1, R ⁹ represents a hydrogen atom or an alkyl group. R ⁹ has the same meaning as R ^{4 in} formula 2 above, and preferred ones are also the same.
L is a single bond, a divalent linking group selected from an alkylene group, an arylene group, —C (═O) —, —O— and —N (R ¹⁰ ) —, or a linking group thereof. A divalent linking group formed by combining two or more types is shown. R ¹⁰ represents a hydrogen atom or an alkyl group, and has the same meaning as R ⁷ described above, and preferred ones are also the same.
L in the general formula 2-1 has the same meaning as L in the general formula 2, and preferred ones are also the same.
In the repeating units represented by General Formula 2 and General Formula 2-1, the acetoacetoxy group in each repeating unit may be substituted with a substituent.

The adhesive polymer has, as the repeating unit [b], a repeating unit derived from an acrylate compound (in the compounds represented by the general formulas 2 and 2-1, L is —C (═O) — and —O— It is preferable to have a combination.

Preferred examples of the repeating unit [b] are shown below as structural formulas, but the present invention is not limited to these examples.
In the following specific examples, B-1 to B-4, B-12, B-13, B-17 to B-30, B-42 to B47 and B-50 are repeating units derived from (meth) acrylic acid ester compounds. B-5, B-14 to B-16 are repeating units derived from (meth) acrylic acid compounds, and B-6 to B-11, B-48 and B-49 are derived from (meth) acrylamide compounds. B-31 to A-34 are repeating units derived from a vinyl acetate compound, B-35 and B-36 are repeating units derived from a vinyl ketone compound, and B-37 to B-41 are anhydrous. It is a repeating unit derived from a maleic acid compound, and B-51 is a repeating unit derived from a styrene compound.

The adhesive polymer is not particularly limited as to the content of each repeating unit as long as it has both the repeating unit [a] and the repeating unit [b].

From the viewpoint of increasing the affinity between the adhesive polymer layer and the cellulose ester layer and obtaining a laminate having excellent interlayer adhesion, the total amount of monomer components (repeating units) constituting the adhesive polymer is The molar amount of the repeating unit [b] is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more. The molar amount of the repeating unit (b) occupying in the total molar amount of the monomer component constituting the adhesive polymer is preferably 95 mol% or less, more preferably 90 mol% or less, and even more preferably 80 mol% or less. .

In addition, from the viewpoint of obtaining a laminate having both adhesion and moisture content at a higher level, the molar amount of the repeating unit [a] in the total molar amount of the monomer components constituting the adhesive polymer is determined. It is preferably 5 mol% or more, more preferably 10 mol% or more, still more preferably 20 mol% or more, still more preferably 30 mol% or more, and 40 mol% or more. It is particularly preferable to set it to 50 mol% or more. The molar amount of the repeating unit [a] in the total molar amount of the monomer components constituting the adhesive polymer is preferably 95 mol% or less, and more preferably 90 mol% or less.

In the adhesive polymer, the content of the repeating unit [a] and the content of the repeating unit [b] are in a molar ratio: [[a] repeating unit] / [[b] repeating unit. ] = 95/5 to 10/90, preferably [repeat unit of [a]] / [repeat unit of [b]] = 95/5 to 30/70, more preferably [[a ] [Repeat unit] / [repeat unit of [b]] = 92/8 to 50/50 is more preferable, and [repeat unit of [a]] / [repeat unit of [b]] = 90/10 It is particularly preferable to satisfy ˜60 / 40, and most preferably, [repeat unit of [[a]] / [repeat unit of [b]] = 90/10 to 75/25.

In the adhesive polymer, the molar amount of the repeating unit represented by the general formula 1 in the total molar amount of the repeating unit [a] is preferably 50 mol% or more, and 70 mol% or more. More preferably, it is more preferably 80 mol% or more, and particularly preferably 90 mol% or more. The adhesive polymer preferably has a molar amount of the repeating unit represented by the general formula 1 in the total molar amount of the repeating unit [a] of 100 mol% or less. It is also preferred that all of the repeating units [a] contained therein are repeating units represented by the above general formula 1.
In the adhesive polymer, the molar amount of the repeating unit represented by the general formula 1-1 in the total molar amount of the repeating unit [a] is preferably 50 mol% or more, and 70 mol% or more. More preferably, it is more preferably 80 mol% or more, and particularly preferably 90 mol% or more. Further, the adhesive polymer preferably has a molar amount of the repeating unit represented by the general formula 1-1 in the total molar amount of the repeating unit [a] of 100 mol% or less. It is also preferred that all of the repeating units [a] contained in the functional polymer are repeating units represented by the general formula 1-1.

In the adhesive polymer, the molar amount of the repeating unit represented by the above general formula 2 in the total molar amount of the repeating unit [b] is preferably 50 mol% or more, and 70 mol% or more. More preferably, it is more preferably 80 mol% or more, and particularly preferably 90 mol% or more. In addition, the adhesive polymer preferably has a molar amount of the repeating unit represented by the general formula 2 in the total molar amount of the repeating unit [b] of 100 mol% or less. It is also preferred that all of the repeating units [b] contained therein are repeating units represented by the above general formula 2.
In the adhesive polymer, the molar amount of the repeating unit represented by the general formula 2-1 in the total molar amount of the repeating unit [b] is preferably 50 mol% or more, and 70 mol% or more. More preferably, it is more preferably 80 mol% or more, and particularly preferably 90 mol% or more. The adhesive polymer preferably has a molar amount of the repeating unit represented by the general formula 2-1 in the total molar amount of the repeating unit [b] of 100 mol% or less. It is also preferred that all of the repeating units [b] contained in the conductive polymer are repeating units represented by the general formula 2-1.

The adhesive polymer may have other repeating units in addition to the repeating unit [a] and the repeating unit [b] as long as the effects of the present invention are not impaired. In the total molar amount of the monomer component constituting the adhesive polymer, the content of the repeating unit (a) and the content of the repeating unit (b) are preferably 50% by mass or more in total. More preferably, it is 70 mass% or more, More preferably, it is 80 mass% or more, It is especially preferable that it is 90 mass% or more. In the adhesive polymer, the molar amount of the repeating unit [a] and the repeating unit [b] is preferably 100 mol% or less in total, and the repeating unit [a] and the above [b] It is also preferred that the form is composed of repeating units.

The reason why the layer using the adhesive polymer having the repeating unit [a] and the repeating unit [b] is excellent in adhesion to the cellulose ester layer is not clear, but is estimated as follows. That is, the solubility parameter δt of the repeating unit in the condition [b] is relatively close to the solubility parameter δt of the cellulose ester, and it is considered that a partial gradient occurs in the affinity with the cellulose ester in the adhesive polymer layer. . And it is estimated that a part with a comparatively high affinity with a cellulose ester interacts effectively with a cellulose-ester layer, and improves interlayer adhesiveness. Moreover, since the adhesive polymer also has the repeating unit [a] having a high solubility parameter δt, the moisture permeability of the laminate can be effectively suppressed.
Furthermore, the laminate in which the adhesive polymer layer and the cellulose ester layer are laminated has a structure in which moisture penetrated into the inside is suppressed and moisture permeability is more effectively suppressed due to the laminated structure of different materials. it is conceivable that.

The adhesive polymer contains the repeating unit [a] and the repeating unit [b], and can efficiently express the characteristics of each repeating unit. In particular, when the repeating unit [a] and the repeating unit [b] have a good balance in the above-mentioned preferred composition ratio (molar ratio), the characteristics of each repeating unit are made compatible at a higher level. be able to. For example, the adhesive polymer exhibits excellent water resistance by having the repeating unit [a] having a smaller solubility parameter δt than the repeating unit [b].

The lower limit of the weight average molecular weight of the adhesive polymer used in the present invention is not particularly limited, but is preferably 5,000 or more, more preferably 10,000 or more, and 15,000 or more. Is more preferably 35,000 or more, and most preferably 75,000 or more. On the other hand, the upper limit value of the weight average molecular weight of the adhesive polymer is preferably 2,000,000 or less, more preferably 1,500,000 or less, and 1,000, from the viewpoint of film forming properties. Is more preferably 50,000 or less, even more preferably 750,000 or less, still more preferably 500,000 or less, particularly preferably 350,000 or less, and 250,000 or less. Most preferably it is.
The molecular weight can be measured by the method described in Examples described later.

The film thickness of the adhesive polymer layer is not particularly limited, preferably 1 to 25 μm, more preferably 1 to 20 μm, and particularly preferably 1 to 15 μm.

[Cellulose ester layer]
The cellulose ester 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 layer, 70 mass% or more is more preferable, 80 mass% or more is further more preferable, and 85 mass% or more is especially preferable. The upper limit of the content of the cellulose ester in the cellulose ester 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 layer of the present invention will be described.
The cellulose ester can be used without particular limitation as long as it is a cellulose ester used for the production of a cellulose ester film.
The β-1,4-bonded glucose unit constituting cellulose has free hydroxy groups at the 2nd, 3rd and 6th positions. The cellulose ester is a polymer (polymer) obtained by esterifying a part of these hydroxy groups with an esterifying agent or the like.
Examples of cellulose include cotton linter and wood pulp (hardwood pulp, softwood pulp), and the like. Any cellulose obtained from any raw material cellulose can be used, and in some cases, a mixture may be used. Raw material cellulose is, for example, Marusawa and Uda, “Plastic Materials Course (17) Fibrous Resin”, Nikkan Kogyo Shimbun (published in 1970) and JIII Journal of Technical Publication 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.
The acyl substitution degree (hereinafter, sometimes simply referred to as “substitution degree”) 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, if all glucose units are all acylated at position 6, the total degree of acyl substitution is 1. Similarly, the total acyl substitution degree is 1 when all of any one of the 6-position and 2-position is acylated in each glucose unit in all hydroxy groups of all glucose.
That is, the degree of substitution indicates the degree of acylation, where 3 is the case where 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, from the viewpoint of moisture permeability, and 2.30 or more. More preferably, it is less than 2.97, and particularly preferably 2.30 to 2.95.

The acyl group of the cellulose acylate used in the present invention is not particularly limited, and may have one acyl group or may have two or more acyl groups. 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, cyclohexane Examples include carbonyl, 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 or more from the viewpoint of moisture permeability and optical properties. It is preferably 3.00 or less, more preferably 2.20 to 3.00, even more preferably 2.30 to 3.00, and 2.30 to 2.97. More preferred is 2.30 to 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. 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 an acyl group having 3 to 4 carbon atoms is contained, the degree of substitution 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.
In addition, mixed acid esters having fatty acid acyl groups and substituted or unsubstituted aromatic acyl groups described in paragraphs [0023] to [0038] of JP-A-2008-20896 can also be preferably used.

In the present invention, two types of cellulose esters or cellulose acylates having one or both of an ester group and a degree of substitution can be used in combination. In this case, you may form as a laminated structure which consists of a different cellulose ester by the co-casting method etc. which are mentioned later.

The degree of polymerization of the cellulose ester or cellulose acylate used in the present invention is preferably 250 to 800, more preferably 300 to 600. The number average molecular weight of the cellulose ester or cellulose acylate used in the present invention is preferably 40000 to 230,000, more preferably 60000 to 230,000, and most preferably 75,000 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 layer of the present invention, other resins (for example, (meth) acrylic resin etc.) can be used in combination with the cellulose ester within a range not impairing the effects of the present invention. 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, still more preferably 20% by mass or less, and particularly preferably 15% by mass or less in the cellulose ester film. 10 mass% or less is the most preferable.

<Formation of cellulose ester layer>
Next, the formation of the cellulose ester layer will be described.
The method for forming the cellulose ester layer is not particularly limited. For example, a melt film forming method or a solution film forming method (solvent casting method) is preferable, and the solution film forming method is more preferable in consideration of volatilization and decomposition of additives. preferable. 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 the Japanese Patent Publications Nos. 45-4554, 49-5614, JP-A-60-176834, JP-A-60-203430, and JP-A-62-115035. The cellulose ester layer may be subjected to a stretching treatment. For the stretching method and conditions, refer to, for example, JP-A-62-115035, JP-A-4-152125, 4-284221, 4-298310, and 11-48271. can do.

(Casting)
The solution casting method includes a method of uniformly extruding the prepared dope from a pressure die onto a metal support, and a doctor that adjusts the film thickness with a blade of the dope once cast on a metal support. There are a method using a blade and a method using a reverse roll coater which adjusts with a reverse 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 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, a coating method, It is particularly preferable to use the simultaneous co-casting (also referred to as simultaneous multi-layer co-casting) method from the viewpoint of stable production and production cost reduction.
When producing a cellulose ester 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 provided on a casting support (band or drum) from a separate slit or the like. The dope is extruded using a casting die that can be extruded at the same time, 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, a casting dope for the first layer is first extruded from a casting die on a casting support, cast, and dried or dried without being dried. The dope for casting for two layers is extruded from the casting die, and if necessary, the dope is successively cast or laminated to the third layer or more and peeled off from the support after an appropriate time. And dried to form a cellulose ester layer.
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. Form a layer.

(Stretching)
The cellulose ester layer is also preferably stretched after casting and drying. The stretching direction of the cellulose ester layer may be either a film transport direction (MD (Machine Direction) direction) or a direction (TD (Transverse Direction) direction) orthogonal to the transport 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 conveyance 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 the slow axes in the plane of the layer are arranged in parallel is preferable. Since the transmission axis of the roll film polarizer produced continuously is generally parallel to the width direction of the roll film, the protection comprising the roll film polarizer and the roll film cellulose ester layer is used. In order to continuously bond the films, the in-plane slow axis of the roll film-like protective film needs to be parallel to the width direction of the cellulose ester 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, stretching may be performed in a state including the residual solvent amount, and the residual solvent amount = (residual volatile matter mass / film mass after heat treatment) × 100% is stretched in a state of 0.05 to 50%. It is preferable to do. It is more preferable to stretch 5 to 80% in a state where the residual solvent amount is 0.05 to 5%.

<Additives>
The said cellulose-ester layer may contain the additive in the range which does not impair the effect of this invention. Examples of the additive include known plasticizers, organic acids, dyes, polymers, retardation adjusting agents, ultraviolet absorbers, antioxidants, matting agents, and the like. Regarding these, the description of paragraph numbers [0062] to [0097] of JP2012-155287A can be referred to, and the contents thereof are incorporated in the present specification. Examples of the additive include a peeling accelerator, an organic acid, and a polyvalent carboxylic acid derivative. With respect to these, the description of WO2015 / 005398, paragraphs [0212] to [0219] can be referred to, and the contents thereof 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 layer contains two or more additives), the total content thereof is preferably 50 parts by mass or less with respect to 100 parts by mass of the cellulose ester, The amount is more preferably 30 parts by mass or less, and further preferably 5 to 20 parts by mass.

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

Although it does not specifically limit as a plasticizer, The polyvalent ester compound (henceforth "polyhydric alcohol ester plasticizer") of a polyhydric alcohol, and a polycondensation ester compound (henceforth "polycondensation ester plasticizer") Or a carbohydrate compound (hereinafter also referred to as “carbohydrate derivative plasticizer”). For polyhydric alcohol ester plasticizers, paragraphs [0081] to [0098] of WO2015 / 005398, and for polycondensed ester plasticizers, paragraphs [0099] to [0122] of the same publication, carbohydrate derivative plasticizers. Can be referred to paragraphs [0123] to [0140] of the same publication, the contents of which are incorporated herein.
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.

The content of the plasticizer 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 preferably 2 to 15 parts by mass, more preferably 5 to 15 parts by mass.
Two or more plasticizers may be used in combination. Also when using 2 or more types together, the specific example and preferable range of content are the same as the above.

(Antioxidant)
One preferable additive may include an antioxidant. Regarding the antioxidant, reference can be made to the description of paragraphs [0143] to [0165] of International Publication No. 2015/005398, the contents of which are incorporated herein.

(Radical scavenger)
One preferred additive may include a radical scavenger. Regarding the radical scavenger, the description in paragraphs [0166] to [0199] of International Publication No. 2015/005398 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 be mentioned. With regard to the deterioration preventing agent, the description in paragraphs [0205] to [0206] of International Publication No. 2015/005398 can be referred to, and the contents thereof are incorporated in the present specification.

(Barbituric acid compound)
The cellulose ester layer may 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 layer by adding this compound. For example, the barbituric acid compound is effective for improving the hardness of the cellulose ester layer. The barbituric acid compound is also effective in improving the durability of a polarizing plate having a cellulose ester layer containing this compound against light, heat or humidity. Regarding the barbituric acid compound that can be used in the cellulose ester layer, for example, the description in paragraphs [0029] to [0060] of International Publication No. 2015/005398 can be referred to, and the contents thereof are incorporated herein.

<Saponification treatment>
The cellulose ester 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 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 temperature of the alkaline solution is preferably in the range of room temperature (25 ° C.) 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.

The film thickness of the cellulose ester layer is preferably 1 to 80 μm, more preferably 1 to 60 μm, still more preferably 3 to 60 μm.
When the cellulose ester layer has a laminated structure of three or more layers, the thickness of the core layer is preferably 3 to 70 μm, more preferably 5 to 60 μm. In the case of a three-layer structure, the thickness of skin layer A and skin layer B is preferably 0.5 to 20 μm, more preferably 0.5 to 10 μm, and still more preferably 0.5 to 3 μm. The core layer is a layer located inside in the laminated structure, and in the case of a three-layer structure, the core layer is an intermediate layer, and the skin layers A and B are layers located outside in the laminated structure or the three-layer structure. Say.

[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, a cellulose ester layer can be produced by a method described later, and then an adhesive polymer layer can be formed by various known coating methods to produce a laminate. Although there is no restriction | limiting in particular as such a coating method, A micro gravure coating system can be used preferably. In addition, even if it is a case where any application | coating method is used, if an adhesive polymer is melt | dissolved in a suitable solvent by a suitable density | concentration, a coating liquid will not be specifically limited, Coating conditions and film-forming conditions Is not particularly limited.
In addition, from the viewpoint of suitability for mass production, it can be produced by a melt casting method or a solution 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 preferable. 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.

<Physical properties of the laminate>
(Haze)
In the laminate of the present invention, the haze measured by the following method is preferably 1% or less, more preferably 0.7% or less, and particularly preferably 0.5% or less. A laminate exhibiting such haze is excellent in transparency and suitable as a film member for a liquid crystal display device. Although the lower limit of haze is 0.001% or more, for example, it is not specifically limited.
The haze is measured in accordance with JIS K7136 (2000) using a haze meter (HGM-2DP, Suga Test Instruments) in an environment of 25 ° C. and a relative humidity of 60% using a laminate 40 mm × 80 mm.

(Film thickness)
The film thickness of the laminate of the present invention can be appropriately determined according to the application, but can be set to 5 to 100 μm, 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. The film thickness of the laminate is more preferably 8 to 80 μm, still more preferably 10 to 70 μm.

(Moisture permeability)
The moisture permeability of the laminate is measured under the conditions of 40 ° C. and 90% relative humidity based on the description of JIS Z-0208.
Moisture permeability of the laminate of the present invention is preferably not more than 1600g ^/ m 2 ^/ day, more preferably not more than 1000g ^/ m 2 ^/ day, more preferably at most 600g ^/ m 2 ^/ day , 200 g / m ² / day or less is particularly preferable. 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 water content at a relative humidity of 80% is preferably 0% by mass or more and less than 4% by mass. The content 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 less than 4% by mass, the dependence of retardation on humidity changes does not become too great, and the display unevenness of the liquid crystal display device at the time of black display after normal temperature, high humidity and high temperature and high humidity environment is suppressed. This is also preferable.
The moisture content can be measured by a Karl Fischer method using a film sample 7 mm × 35 mm using a moisture measuring device and sample drying apparatuses “CA-03” and “VA-05” (both manufactured by Mitsubishi Chemical Corporation). . 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. In general, a polarizing plate in which both surfaces of a polarizer are sandwiched between polarizing plate protective films to protect both surfaces is widely used.

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 layer in the laminate is bonded to at least one surface of the polarizer using an adhesive. Can do.

The laminate of the present invention can be used as a polarizing plate protective film. When using as a polarizing plate protective film, the preparation method of the polarizing plate of this invention is not specifically limited, It can produce according to a general method. For example, there is a method in which the laminate of the present invention is treated with an alkali 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 or JP-A-6-118232 may be applied. Other surface treatments can also be performed. Examples of other surface treatments include methods such as corona discharge, glow discharge, ultraviolet (UV) irradiation, and flame treatment.
When the laminate has a form in which an adhesive polymer layer is provided on one side of the cellulose ester layer, the laminate surface of the laminate with the polarizer may be on the adhesive polymer layer side, or on the cellulose ester layer side. But it ’s okay. From the viewpoint of improving the adhesion between the polarizer and the laminate, it is preferable to directly bond the cellulose ester layer side to the polarizer.

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.

Although it does not specifically limit as an adhesive agent used for bonding a polarizing plate protective film and a polarizer, For example, the aqueous solution of polyvinyl alcohol or polyvinyl acetal (for example, polyvinyl butyral), vinyl polymer (for example, polybutyl) Acrylate) latex, UV curable adhesive, and the like. A particularly preferred adhesive is an aqueous solution of fully saponified polyvinyl alcohol.

The polarizing plate is composed of a polarizer and protective films protecting both surfaces thereof, and at least one of the protective films is preferably a laminate of the present invention. The polarizing plate of the present invention includes the laminate of the present invention as a polarizing plate protective film. Therefore, deterioration of the polarizer is effectively prevented, and high polarizer durability is exhibited. Furthermore, it is also preferable that this polarizing plate is constituted by laminating a separate film on the surface. The separate film is used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection. The separate film is used for the purpose of covering the adhesive layer to be bonded to the liquid crystal plate, and is used on the surface side of the polarizing plate to be bonded to the liquid crystal plate.

The polarizing plate of the present invention preferably has the following physical properties or characteristics.
(Orthogonal transmittance CT)
In the polarizing plate of the present invention, the value of the orthogonal transmittance CT at a wavelength of 410 nm is preferably CT ≦ 2.0 (all units are%), more preferably CT ≦ 1.3, and CT ≦ More preferably, 0.6, and particularly preferably CT ≦ 0.05. The lower the orthogonal transmittance at a wavelength of 410 nm, the less light leakage near the wavelength of 410 nm. On the other hand, the higher the orthogonal transmittance at the wavelength of 410 nm, the more light leaks around the wavelength of 410 nm, and the black display on the display becomes blue. Therefore, a low orthogonal transmittance means that the polarization performance is good. From the viewpoint of changing performance such as color reproducibility, the orthogonal transmittance at a wavelength of 410 nm is preferably low. The orthogonal transmittance can be measured using, for example, an automatic polarizing film measuring apparatus: VAP-7070 (manufactured by JASCO Corporation).

(Orthogonal transmittance change)
The polarizing plate of the present invention is excellent in durability, more specifically, in suppressing deterioration of polarizing plate performance even when left for a long time under high temperature and high humidity conditions. As an index for evaluating durability, the amount of change in the orthogonal transmittance before and after the polarizing plate is placed under high temperature and high humidity for a predetermined period can be used. For example, the amount of change in orthogonal transmittance at a wavelength of 410 nm when left in an environment of 80 ° C. and relative humidity of 85% for 500 hours [change amount = (orthogonal transmittance after standing (%)) − (orthogonal transmittance before standing) Rate (%))] is preferably 0.05% or less, more preferably the change amount is 0.03% or less, still more preferably the change amount is zero or less, and the change amount is negative. It is particularly preferable that the value, that is, the orthogonal transmittance after being left is smaller than the orthogonal transmittance before being left. This means that the polarization performance has improved during standing at high temperature and high humidity. In the present invention, in addition to preventing deterioration of polarization performance under high temperature and high humidity, it is also possible to improve polarization performance.

In the present invention, the orthogonal transmittance uses an average value when measured 10 times. Further, the amount of change in the orthogonal transmittance is obtained as the difference between the average values obtained by performing the measurement 10 times before and after leaving.

(Other characteristics)
Other preferable optical characteristics 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 liquid crystal display device as an embodiment of the image display device of the present invention includes a liquid crystal cell in which liquid crystal is supported between two electrode substrates, two polarizing plates disposed on both sides thereof, and Accordingly, at least one optical compensation film is provided between the liquid crystal cell and the polarizing plate.
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 layer 24 and a first (upper liquid crystal cell) electrode substrate 23 and a second (lower liquid crystal cell) electrode substrate 25 arranged on both surface sides (referred to as upper and lower sides in FIG. 2). A first (upper) polarizing plate 21 and a second (lower) polarizing plate 26 disposed on both sides of the liquid crystal cell. 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.
Although not shown, the first polarizing plate 21 and the second 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. Moreover, after arrange | positioning the laminated body of this invention as a polarizing plate protective film of the 1st polarizing plate 21 (viewing side polarizing plate) among two polarizing plates, it is further the 2nd polarizing plate 26 (backlight side polarizing plate). It is also preferable to arrange the laminate of the present invention as a polarizing plate protective film. Thereby, expansion / contraction of the polarizer contained in two polarizing plates can be suppressed, and the curvature of a panel can be prevented. The liquid crystal display device 20 of the present invention is preferably laminated in the order of the laminate of the present invention as a polarizing plate protective film, a polarizer, and a general transparent protective film from the outside of the device (the side far from the liquid crystal cell).

The liquid crystal layer 24 of the liquid crystal cell is usually formed by sealing liquid crystal in a space formed by sandwiching a spacer between two substrates. The transparent electrode layer is formed on the substrate as a transparent film containing a conductive substance. Thereby, it becomes an electrode substrate provided with the substrate and the transparent electrode layer. The liquid crystal cell may further be provided with a gas barrier layer, a hard coat layer, or an undercoat layer (undercoat layer) (used for adhesion of the transparent electrode layer). These layers are usually provided on the substrate.

The laminate of the present invention can also be preferably used as an optical compensation film for liquid crystal display devices. In this case, the liquid crystal display device has a liquid crystal cell in which liquid crystal is supported between two electrode substrates, two polarizers disposed on both sides thereof, and at least between the liquid crystal cell and the polarizer described above. It is more preferable that the laminate of the present invention is arranged as an optical compensation film.

(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-Ferroelectric Liquid Crystal), OCB (Optically LilyCryBTS). Various display modes such as (Electrically Controlled Birefringence) and HAN (Hybrid Aligned Nematic) have been proposed. In addition, a display mode in which the above display mode is oriented and divided has been proposed. The cellulose 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>
Into a 1 L three-necked flask equipped with a thermometer, a stirring blade and a reflux ring, 75.0 g of methyl ethyl ketone was charged and stirred at 85 ° C. under a nitrogen stream. Separately, in a 300 mL Erlenmeyer flask, 133.5 g of styrene (a compound that leads to repeating unit A-1 exemplified above), 16.5 g of 2-hydroxyethyl acrylate (a monomer that leads to repeating unit B-1 exemplified above), A monomer composition was prepared by measuring 0.1 g of dimethyl 2,2′-azobisisobutyrate and 75.0 g of methyl ethyl ketone and mixing and dissolving them.
Next, the monomer composition was dropped into methyl ethyl ketone stirred at 85 ° C. at a rate of 1.1 mL / min. A chemical pump was used for dripping. The reaction solution after completion of the addition was further reacted at 85 ° C. for 6 hours. After the reaction was completed, the reaction solution was allowed to cool to room temperature (25 ° C.), diluted with 500 mL of methyl ethyl ketone, and reprecipitated with 5 L of methanol to form a white precipitate. Obtained. The obtained white precipitate was filtered off, redispersed and washed with 2 L of methanol three times, and dried at 60 ° C. overnight to obtain 91.0 g of the target polymer P-1.

<Synthesis Examples 2 to 22: Synthesis of Polymers P-2 to P-22>
In the synthesis example 1, as shown in the following Table 1, the same as the synthesis example 1 except that the monomer for introducing the repeating unit or the charging ratio thereof was changed or the amount of the polymerization initiator used was changed appropriately. Thus, polymers P-2 to P-22 were synthesized.
In Table 1 below, the numbers described in the “Structure” column of the repeating unit correspond to the numbers of the repeating unit exemplified above (the same applies hereinafter).

<Comparative Synthesis Examples 1 and 2: Synthesis of Comparative Polymers HP-1 and HP-2>
Comparative Polymers HP-1 and HP-2 were obtained in the same manner as in Synthesis Example 1 except that the monomer type used in the Synthesis Example 1 was changed to a monomer that leads to the repeating unit shown in Table 1 below.

Table 1 below shows solubility parameters δt calculated by the Hoy method of the repeating units constituting the polymers obtained in the above synthesis examples and comparative synthesis examples.
Table 1 below also shows the content (mol%) of each repeating unit in the polymers obtained in the above synthesis examples and comparative synthesis examples. Here, the content of the repeating unit in the polymer is a chart obtained by measuring ¹ H-NMR of each polymer using a nuclear magnetic resonance (NMR) spectrum measurement apparatus (manufactured by BRUKER, 300 MHz). It was calculated (identified) from the integrated value.
Table 1 below shows the weight average molecular weights of the polymers obtained in the above synthesis examples and comparative synthesis examples. 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 equipment: GPC equipment manufactured by Tosoh Corporation (HLC-8320GPC, Ecosec)
Column: TSK gel SuperHZM-H, TSK gel SuperHZ4000, TSK gel SuperHZ2000 combined use (Tosoh, 4.6 mm ID (inner diameter) x 15.0 cm)
Eluent: Tetrahydrofuran (THF)
Measurement temperature: 40 ° C
Carrier flow rate: 1.0 mL / min
Sample concentration: 0.1% by mass
Detector: RI (refractive index) detector

[Production Example 1: Production of laminates S-1 to S-26 and HS-1 and HS-2]

<Preparation of cellulose ester 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 mass Ultraviolet absorber (manufactured by Tinuvin 326 Ciba Japan) 0.2 part by mass Methylene chloride (first solvent) 336 parts by mass Methanol (second solvent) 29 parts by mass 1-butanol (third solvent) 11 parts by mass ――――――――――――――――――――――――――――――――

Using a band casting apparatus, the prepared dope A 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 A reaches 40% by mass, it is peeled off as a polymer film from the casting support, and is conveyed without being actively stretched by a tenter and dried at 130 ° C. in a drying zone. went. The obtained cellulose ester layer (cellulose ester film) CA-1 had a thickness of 55 μm.

<Preparation of cellulose ester layer CA-2>
Using the band casting apparatus, the prepared dope A was uniformly cast from a casting die onto a stainless steel endless band (casting support) having a width of 2000 mm. When the residual solvent amount in the dope A reaches 40% by mass, the polymer film is peeled from the casting support, and the rotational speed of the downstream roller is made higher than the rotational speed of the upstream roller at the transition portion. Is stretched 1.2 times in the transport direction (MD) at a temperature of 170 ° C. and 1.5 times in the direction perpendicular to the transport direction (TD direction) with a tenter (stretch ratio is 1. 8 times), drying was performed at 130 ° C. in the drying zone. The film thickness of the obtained cellulose ester layer (cellulose ester film) CA-2 was 40 μm.

<Preparation of cellulose ester layer CA-3>
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution (dope B) having a solid content concentration of 22% by mass.

――――――――――――――――――――――――――――――――――
Composition of cellulose acetate solution (Dope B) ――――――――――――――――――――――――――――――――――
Cellulose acetate with an acetyl substitution degree of 2.87 100 parts by mass Monopet (registered trademark) SB (plasticizer) manufactured by Daiichi Kogyo Kagaku
9.0 parts by weight SAIB-100 (plasticizer) manufactured by Eastman Chemical Co., Ltd. 3.0 parts by weight UV absorber (UV-1 below) 2.0 parts by weight Methylene chloride (first solvent) 297.7 parts by weight Methanol (Second solvent) 75.4 parts by mass 1-butanol (third solvent) 3.8 parts by mass ――――――――――――――――――――――――――― ―――――――

Using a band casting apparatus, the prepared dope B 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 B reaches 40% by mass, it is peeled off as a polymer film from the casting support, transported without being actively stretched by a tenter, and dried at 130 ° C. in a drying zone. went. The obtained cellulose ester layer (cellulose ester film) CA-3 had a thickness of 55 μm.

<Preparation of cellulose ester layer CA-4>
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution (dope C) having a solid content concentration of 22% by mass.

――――――――――――――――――――――――――――――――――
Composition of cellulose acetate solution (Dope C) ――――――――――――――――――――――――――――――――――
Cellulose acetate with an acetyl substitution degree of 2.87 100 parts by weight Polycondensation polymer (A) (plasticizer) 12.0 parts by weight UV absorber (UV-1) 2.0 parts by weight Methylene chloride (first solvent) 297.7 Part by mass Methanol (second solvent) 75.4 parts by mass 1-butanol (third solvent) 3.8 parts by mass ――――――――――――――――――――――― ――――――――――

Polycondensation polymer (A): Polyester composed of adipic acid and ethanediol (terminal is a hydroxy group) (number average molecular weight = 1000)

Using a band casting apparatus, the prepared dope C 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 C reaches 40% by mass, it is peeled off as a polymer film from the casting support, and conveyed without being actively stretched by a tenter and dried at 130 ° C. in a drying zone. went. The obtained cellulose ester layer (cellulose ester film) CA-4 had a thickness of 55 μm.

<Preparation of cellulose ester layer CA-5>
In the production of the cellulose ester layer CA-3, a cellulose ester layer having a thickness of 55 μm was prepared in the same manner as in the production of the cellulose ester layer CA-3 except that 4.0 parts by mass of the following barbituric acid compound (1) was added. (Cellulose ester film) CA-5 was obtained.

The barbituric acid compound (1) is a barbituric acid compound (Exemplary Compound A-3) described in International Publication No. 2015/005398, and was synthesized by the method described in the publication.

<Preparation of laminate S-1>
The polymer P-1 was mixed with methyl ethyl ketone so as to have a solid content of 15% by mass, 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. Thus, an adhesive polymer forming composition was obtained. Next, the adhesive polymer-forming composition was applied onto the cellulose ester layer CA-1 produced above using a gravure coater. Subsequently, it was dried at 25 ° C. for 1 minute, and further dried at 120 ° C. for about 5 minutes to obtain a laminate S-1 having a film thickness of 60 μm.

<Preparation of Laminates S-2 to S-26 and Comparative Laminates HS-1 and HS-2>
In the production of the laminate S-1, the polymer P-1 used in the adhesive polymer forming composition was changed as shown in Table 2 below, and the cellulose ester layer was changed as shown in Table 2 below. In the same manner as in the production of the laminated body S-1, laminated bodies S-2 to S-26 and comparative laminated bodies HS-1 and HS-2 were produced. The thicknesses of the obtained laminates were all 60 μm.

<Evaluation of laminate>
About each produced laminated body, the moisture content and adhesiveness were evaluated by the following method. The results are shown in Table 2.

(1) Measurement of moisture content of laminate (water content at 25 ° C. and 80% relative humidity) After each laminate was placed in an environment of 80% relative humidity at a temperature of 25 ° C. for 24 hours, the following method was used. Thus, the moisture content was measured.
The moisture content was measured using a Karl Fischer method with a sample obtained by cutting each laminate into 7 mm x 35 mm with a moisture measuring device: CA-03 and a sample drying device: VA-05 (both manufactured by Mitsubishi Chemical Corporation). did. The measured moisture content (g) was divided by the sample mass (g) to calculate the moisture content, and this moisture content was evaluated according to the following evaluation criteria.
In this test, the moisture content is evaluated as A to C among the following four-stage evaluation, A and B are preferable, and A is more preferable.

A: Moisture content is 1.0% or more and less than 1.5% B: Moisture content is 1.5% or more and less than 2.5% C: Moisture content is 2.5% or more and less than 4.0% D: The water content is 4.0% or more

(2) Adhesion test of laminated body As a method for evaluating the adhesion between a layer containing a polymer and a layer containing cellulose acetate, a cross-cut test (cross-cut method) according to JIS K 5400 was applied. The specific procedure is shown below.
In each of the produced laminates, 11 cuts were made at intervals of 1 mm on the surface on the adhesive polymer layer side using a cutter knife and a cutter guide to produce 100 grids. After cellophane tape (registered trademark) is strongly pressure-bonded on this grid, the end of the tape is peeled off at an angle of 45 ° with respect to the surface, and the grid is in a state of peeling (the state of the grid constituting the grid) Was observed. The observation results were evaluated by applying the following evaluation criteria (the ratio (%) of peeled lattice eyes to 100 lattice eyes).
In this test, among the following four-stage evaluations, evaluations A to C are acceptable levels, evaluations A and B are preferable, and evaluation A is particularly preferable.

A: None of the lattice eyes peel off B: The lattice eye separation is less than 5% C: The lattice eye separation is 5% or more and less than 30% D: The lattice eye separation is 30% or more is there

From the results of Table 2, the laminates S-1 to S-26 each having a layer containing an adhesive polymer having the repeating unit [a] and the repeating unit [b] were all used as laminates. It was shown that the moisture content was small and the adhesion between the layers was excellent.
On the other hand, the laminate HS-1 having a layer containing the polymer HS-1 not having the repeating unit [b] was inferior in interlayer adhesion. On the other hand, the laminate HS-2 having a layer containing the polymer HS-2 having no repeating unit [a] had a high water content.

[Production Example 2: Preparation of polarizing plates PL-1 to PL-3, PL-5 to PL-7, and comparative polarizing plates HPL-1 and HPL-2]
In the following manner, polarizing plates PL-1 to PL-3, PL-5 to PL-7, and comparative polarizing plates HPL-1 and HPL-2 were prepared, respectively.
<Saponification>
Commercially available cellulose acylate film (Fujitack ZRD40, manufactured by Fuji Film) and the various laminates S-1, S-6, S-7, S-24, S-25, S-26HS-1 and HS-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 and dried to obtain a saponified ZRD40 and each laminate.

<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 prepare a polarizer having a thickness of 27 μm.

<Lamination>
Each of the laminates after saponification (the surface on which the adhesive polymer layer of each laminate is not laminated (that is, the surface of the cellulose ester layer) is placed in contact with the polarizer), the polarizer prepared above, The cellulose acylate film ZRD40 after saponification was bonded in this order with a PVA adhesive and thermally dried to obtain polarizing plates PL-1 to PL-3 and PL-5 to PL-7, and HPL- 1 and HPL-2 were produced respectively.
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 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.

Comparative polarizing plate HPL-1 could not be prepared because the cellulose ester layer and the adhesive polymer layer were peeled off during polarizing plate processing.

[Production Example 3: Production of polarizing plates PL-4 and PL-8 to PL-10]
Polarizer plates PL-4 and PL-8 to PL-10 were produced as follows.

<Preparation of active energy ray-curable adhesive composition>
Each component was mixed by the composition shown below, and it stirred at 50 degreeC for 1 hour, and obtained the active energy ray hardening-type adhesive composition.

――――――――――――――――――――――――――――――――――
Composition of active energy ray-curable adhesive composition ――――――――――――――――――――――――――――――――――
Radical polysynthetic compound: Aronix M-220 manufactured by Toa Gosei Co., Ltd.
20.0 parts by mass N-hydroxylacrylamide 40.0 parts by mass Kojin Acroylmorpholine 40.0 parts by mass Radical polymerization initiator: KAYACURE DETX-S manufactured by Nippon Kayaku Co., Ltd.
0.5 parts by mass Radical polymerization initiator: IRGACURE907 manufactured by BASF
1.5 parts by mass ――――――――――――――――――――――――――――――――――

<Preparation of polarizing plates PL-4 and PL-8 to PL-10>
Corona treatment was performed on the adhesive polymer layer side of the laminates S-6, S-24, S-25, and S-26 produced above. On the surface of the laminate subjected to the corona treatment, the active energy ray-curable adhesive composition prepared above is applied to an MCD coater (manufactured by Fuji Machine Co., Ltd., cell shape: honeycomb, number of gravure roll wires: 1000 / INCH, rotation speed). 140% / vs. Line speed) was applied to a thickness of 0.5 μm.
Separately, a cycloolefin film having a thickness of 40 μm (Arton G7810 manufactured by JSR) was prepared, and the surface thereof was subjected to corona treatment. The active energy ray-curable adhesive composition was applied to the corona-treated surface so as to have a thickness of 0.5 μm in the same manner as described above.
Then, the surface which apply | coated the active energy ray-curable adhesive composition of each said laminated body and the surface which apply | coated the active energy ray-curable adhesive composition of a cycloolefin type film were produced in the said manufacture example 2. A polarizing plate precursor was prepared by bonding to both sides of the polarizer. Then, it heated at 50 degreeC using IR heater from both surfaces of this polarizing plate precursor. Subsequently, the active energy ray shown below was irradiated to both surfaces of the polarizing plate precursor, and the said active energy ray hardening-type adhesive composition was hardened. Thereafter, it was dried with hot air at 70 ° C. for 3 minutes to obtain polarizing plates PL-4 and PL-8 to PL-10, respectively.

(Active energy rays)
As active energy rays, ultraviolet rays (gallium filled metal halide lamp), irradiation apparatus: Fusion UV Systems, Inc. Light HAMMER10, bulb: V bulb, peak illuminance: 1600 mW / cm ² , integrated irradiation amount 1000 / mJ / cm ² (wavelength) 380-440 nm) was used. The illuminance of ultraviolet rays was measured using a Sola-Check system manufactured by Solatell.

<Evaluation of polarizer durability of polarizing plate>
The polarizing plate durability of each polarizing plate was evaluated according to the following criteria by the amount of change in orthogonal transmittance in a high temperature and high humidity environment at a temperature of 85 ° C. and a relative humidity of 85% as follows.
The orthogonal transmittance of each of the produced polarizing plates was measured 10 times in the range of 380 to 780 nm using an automatic polarizing film measuring apparatus: VAP-7070 (manufactured by JASCO Corporation). The average value of the orthogonal transmittance at a wavelength of 410 nm was determined and used as the orthogonal transmittance before aging. In addition, the details of the measurement were as described above. The measurement was carried out using a sample (about 5 cm × 5 cm) attached to each polarizing plate on glass with an adhesive so that the polarizing plate protective film was on the air interface side. Was set in a measuring device with the light source facing the light source.
Thereafter, each polarizing plate was stored for 500 hours in an environment of 85 ° C. and a relative humidity of 85%. Next, in the same manner as described above, the average value of the orthogonal transmittance at a wavelength of 410 nm was determined and used as the orthogonal transmittance after aging.
The orthogonal transmittance was measured in an environment at 25 ° C. and a relative humidity of 60%.
The amount of change in orthogonal transmittance before and after storage was determined by the following formula.

Orthogonal transmittance change amount (%) = [Orthogonal transmittance after aging (%)-Orthogonal transmittance before aging (%)]

Polarizer durability was evaluated based on the following criteria for the amount of change in orthogonal transmittance. In this test, evaluations A + to B out of the following five grades are acceptable levels. Evaluations A + and A are preferred, and evaluation A + is particularly preferred.

A +: Change in orthogonal transmittance is −0.01 or more and less than 0.01% A: Change in orthogonal transmittance is 0.01% or more and less than 0.03% B: Change in orthogonal transmittance is 0.03% or more and 0 Less than 05% C: Change in orthogonal transmittance is 0.05% or more and less than 0.1% D: Change in orthogonal transmittance is 0.1% or more

From the results shown in Table 3, all of the polarizing plates HPL-1 to 10 provided with the laminates S-1, S-6, S-7, and S-24 to S-26 of the present invention are orthogonal transmittance change amounts. Was small and showed excellent polarizer durability. That is, by incorporating a polarizing plate using the laminate of the present invention as a protective film for a polarizer into an image display device, deterioration in image quality can be effectively suppressed even when used for a long time under high temperature and high humidity conditions. I understand.
In contrast, the comparative polarizing plate HPL-1 using the comparative laminate HS-1 as a protective film has a poor interlayer adhesion of the protective film, and the cellulose ester layer and the polymer layer are peeled off. It was not possible to produce a polarizing plate capable of performing the above. Further, the comparative polarizing plate HPL-2 using the comparative laminate HS-2 as a protective film resulted in a greatly inferior polarizer durability.

While this invention has been described in conjunction with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified and are contrary to the spirit and scope of the invention as set forth in the appended claims. I think it should be interpreted widely.

This application claims priority based on Japanese Patent Application No. 2015-195325 filed in Japan on September 30, 2015, and Japanese Patent Application No. 2016-016706 filed on January 29, 2016 in Japan. Which are hereby incorporated by reference herein as part of their description.

10 Laminate (laminate)
DESCRIPTION OF SYMBOLS 11 Cellulose ester layer 12 Adhesive polymer layer 20 Liquid crystal display device 21 1st (upper side) polarizing plate 22 Direction of 1st polarizing plate absorption axis 23 1st (on liquid crystal cell) electrode substrate 24 Liquid crystal layer 25 2nd (under liquid crystal cell) ) Electrode substrate 26 Second (lower) polarizing plate 27 Second polarizing plate absorption axis direction

Claims

A laminate having a layer containing a cellulose ester and a layer containing an adhesive polymer,
The layer containing the adhesive polymer is adjacent to at least one surface of the layer containing the cellulose ester;
The adhesive polymer has at least one repeating unit of the following [a] and at least one repeating unit of the following [b].
Laminated body.
[A]: A repeating unit derived from a styrene compound, a terpene compound, a C5 fraction compound or a C9 fraction compound, and having a solubility parameter δt calculated by the Hoy method of 13.5 to 19.5 [B]: A repeating unit derived from an acrylate compound, a (meth) acrylic compound, a (meth) acrylamide compound, a vinyl acetate compound, a vinyl ketone compound, a maleic anhydride compound or a styrene compound, or an ethylenic group other than these repeating units A repeating unit derived from a compound having a saturated bond, and having a solubility parameter δt calculated by the Hoy method of 20.0 to 26.0
The laminate according to claim 1, wherein the adhesive polymer has a repeating unit represented by the following general formula 1 as the repeating unit of [a].

In general formula 1, R 1 , R 2 and R 3 each independently represent a hydrogen atom, a halogen atom, an alkyl group or an aryl group.
R 11 , R 12 , R 13 , R 14 and R 15 each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an acyl group, an acyloxy group or an alkoxycarbonyl group. To express.
The laminate according to claim 1 or 2, wherein the adhesive polymer has a repeating unit represented by the following general formula 2 as the repeating unit of [b].

In General Formula 2, R 4 represents a hydrogen atom or an alkyl group.
R 5 and R 6 each independently represents a hydrogen atom, an alkyl group, an aryl group or an alkoxycarbonyl group.
L is a single bond, an alkylene group, an arylene group, a divalent linking group selected from —C (═O) —, —O— and —N (R 7 ) —, or two or more of these linking groups. The bivalent coupling group which combines these is shown. R 7 represents a hydrogen atom or an alkyl group.
The molar amount of the repeating unit (b) occupying in the total molar amount of the repeating unit constituting the adhesive polymer is 5 mol% or more and 95 mol% or less. Laminated body.
The laminate according to any one of claims 1 to 4, wherein the adhesive polymer has a repeating unit represented by the following general formula 1-1 as the repeating unit of [a].

In general formula 1-1, R 8 represents a hydrogen atom, an alkyl group or an aryl group.
R 21 , R 22 , R 23 , R 24 and R 25 each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an acyl group, an acyloxy group or an alkoxycarbonyl group. To express.
The laminate according to any one of claims 1 to 5, wherein the adhesive polymer has a repeating unit represented by the following general formula 2-1 as the repeating unit of [b].

In general formula 2-1, R 9 represents a hydrogen atom or an alkyl group.
L is a single bond, an alkylene group, an arylene group, a divalent linking group selected from —C (═O) —, —O— and —N (R 10 ) —, or two or more of these linking groups. The bivalent coupling group which combines these is shown. R 10 represents a hydrogen atom or an alkyl group.
The laminate according to any one of claims 1 to 6, wherein the cellulose ester is cellulose acylate.
A polarizing plate comprising the laminate according to any one of claims 1 to 7 and a polarizer.
An image display device having the polarizing plate according to claim 8.