JP6574063B2 - Laminated body, optical film, polarizing plate protective film, polarizing plate and image display device - Google Patents

Description

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

Image display devices represented by electroluminescence displays (ELDs) and liquid crystal display devices (LCDs) are increasingly required to be thin. In addition, the usage environment of image display devices has been diversified, including outdoor applications, and image display devices have the ability to stably maintain good image quality even in harsh environments (high durability). Is now required.
The decrease in image quality in the image display 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 its surface, but the protective film is also required to be thin as the device becomes thinner. When the protective film is thinned, moisture easily comes 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 outdoors.

  As the protective film, cellulose resins, acrylic resins and the like are widely used from the viewpoints of versatility and processability. Modification of the protective film has been promoted from the need to further increase the durability (for example, Patent Document 1). It has also been reported that a polyester resin layer is laminated on the surface of the cellulose resin film in order to modify the optical properties of the protective film (for example, Patent Document 2).

JP 2012-172062 A Special table 2008-544304 gazette

  As a result of repeated studies on the conventional protective film from the viewpoint of suppressing the deterioration of the polarizer, the present inventors have sufficiently solved the problem of the deterioration of the polarizer, particularly when the protective film is thinned to the above-mentioned required level. It has become clear that it cannot respond.

  An object of the present invention is to provide a laminate having a layer containing a cellulose ester and having excellent interlayer adhesion. In addition, the present invention is a laminate having a layer containing a cellulose ester, has a low moisture permeability, and when used as a protective film for a polarizer, the polarizer deteriorates over time even under high temperature and high humidity conditions. It is an object of the present invention to provide a laminate that can effectively suppress the above. Moreover, this invention makes it a subject to provide the optical film, polarizing plate protective film, and polarizing plate using the said laminated body. Another object of the present invention is to provide an image display device using the polarizing plate.

As a result of intensive studies in view of the above-mentioned problems, the present inventors have directly developed a layer containing a cellulose ester and a layer containing a block polymer having a polyamide chain having a specific structure or a graft polymer having a polyamide chain having a specific structure. The laminated body is excellent in adhesion between layers, has a low moisture permeability and excellent moisture barrier function, and when used as a protective film for a polarizer, the polarizer can be used over time even under high temperature and high humidity conditions. It has been found that effective deterioration can be effectively suppressed.
The present invention has been further studied based on these findings and has been completed.

式中、Ｘ^１及びＸ^２はアミド結合を示す。Ｌ^１は単結合又は二価の基を示す。Ｒ^１〜Ｒ^３はアルキル基、アルケニル基、アリール基、アルコキシ基、ヒドロキシ基、カルボキシ基又はハロゲン原子を示す。ｎ^１〜ｎ^３は０〜４の整数である。＊は結合部を示す。
〔２〕
上記Ｌ^１が下記式（１−ａ）〜（１−ｊ）のいずれかで表される、〔１〕記載の積層体。

式中、＊は結合部を示す。
〔３〕
上記ブロックポリマー及び上記グラフトポリマーが下記一般式（２）で表される構造単位を有する、〔１〕又は〔２〕記載の積層体。

式中、Ｒ^４は炭素数１〜２０のアルキル基又は炭素数３〜２０のシクロアルキル基を示す。Ｒ^５は水素原子又はアルキル基を示す。Ｒ^６及びＲ^７は水素原子、アルキル基、アリール基又はアルコキシカルボニル基を示す。＊は結合部を示す。
〔４〕
上記セルロースエステルがセルロースアシレートである、〔１〕〜〔３〕のいずれかに記載の積層体。
〔５〕
〔１〕〜〔４〕のいずれかに記載の積層体を用いた光学フィルム。
〔６〕
〔１〕〜〔４〕のいずれかに記載の積層体を用いた偏光板保護フィルム。
〔７〕
〔１〕〜〔４〕のいずれかに記載の積層体と、偏光子とを有する偏光板。
〔８〕
〔７〕に記載の偏光板を有する画像表示装置。The above-described problems of the present invention have been solved by the following means.
[1]
A laminate having a structure in which a layer containing a cellulose ester and a block polymer containing a polyamide chain and / or a layer containing a graft polymer containing a polyamide chain are arranged adjacent to each other,
A laminate in which the polyamide chain has a structural unit represented by the following general formula (1).

Wherein, ^{X 1} and ^{X 2} represents an amide bond. L ¹ represents a single bond or a divalent group. R ^{1 to} R ^{3 each} represents an alkyl group, an alkenyl group, an aryl group, an alkoxy group, a hydroxy group, a carboxy group, or a halogen atom. n ¹ ~n ³ is an integer of 0-4. * Indicates a connecting part.
[2]
The laminate according to [1], wherein L ¹ is represented by any of the following formulas (1-a) to (1-j).

In formula, * shows a coupling | bond part.
[3]
The laminate according to [1] or [2], wherein the block polymer and the graft polymer have a structural unit represented by the following general formula (2).

In the formula, R ⁴ represents an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 3 to 20 carbon atoms. R ⁵ represents a hydrogen atom or an alkyl group. R ⁶ and R ⁷ represent a hydrogen atom, an alkyl group, an aryl group or an alkoxycarbonyl group. * Indicates a connecting part.
[4]
The laminate according to any one of [1] to [3], wherein the cellulose ester is cellulose acylate.
[5]
[1] An optical film using the laminate according to any one of [4].
[6]
A polarizing plate protective film using the laminate according to any one of [1] to [4].
[7]
A polarizing plate having the laminate according to any one of [1] to [4] and a polarizer.
[8]
The image display apparatus which has a polarizing plate as described in [7].

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

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

In this specification, about the display of a compound, it uses in the meaning containing its salt and its ion besides the compound itself. In addition, it means that a part of the structure is changed as long as the desired effect is achieved.
Examples of the salt of the compound include, for example, an acid addition salt of the compound formed with the compound and an inorganic acid or an organic acid, or a base addition salt of the compound formed with the compound and an inorganic base or an organic base. Is mentioned. In addition, examples of the ion of the compound include an ion including a skeleton of the compound formed by dissociating the salt of the above-described compound.
In the present specification, a substituent that does not clearly indicate substitution or non-substitution (the same applies to a linking group) means that the group may have an arbitrary substituent as long as a desired effect is achieved. . This is also the same for compounds that do not specify substitution or non-substitution.

In the present specification, the term “substituent” includes groups selected from the following substituent group T unless otherwise specified. In addition, when only a substituent having a specific range is described (for example, when only described as “alkyl group”), a corresponding group of the following substituent group T (in the above case, an alkyl group) The preferred range in FIG.
In the present specification, when the number of carbon atoms of a certain group is defined, this number of carbons means the total number of carbon atoms in the group. That is, when this group is a form further having a substituent, it means the total number of carbon atoms including this substituent.

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

The laminate of the present invention, the optical film of the present invention and the polarizing plate protective film using the laminate are excellent in interlayer adhesion. The laminate of the present invention, and the optical film and polarizing plate protective film of the present invention using the same have a low moisture permeability and an excellent moisture barrier function. The laminate of the present invention, the optical film of the present invention and the polarizing plate protective film using the laminate are effective for deterioration of the polarizer over time even under high temperature and high humidity conditions when used as a protective film for the polarizer. Can be suppressed.
The polarizing plate and the image display device of the present invention have the laminate of the present invention that exhibits the above effects, and the deterioration of the polarizer can be effectively suppressed even under high temperature and high humidity conditions.
In the present specification, the degree of suppressing the deterioration of the polarizer 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. FIG. 3A is a diagram showing an example of a block structure of a polymer. FIG. 3B is a diagram showing an example of a block structure of a polymer. FIG. 3C is a diagram showing an example of a block structure of a polymer. FIG. 3D is a diagram showing an example of a block structure of a polymer. FIG. 3E is a diagram showing an example of a block structure of a polymer. FIG. 4A is a diagram illustrating an example of a graft structure of a polymer. FIG. 4B is a diagram showing an example of a graft structure of a polymer. FIG. 4C is a diagram showing an example of a graft structure of a polymer. FIG. 4D is a diagram illustrating an example of a graft structure of a polymer. FIG. 4E is a diagram showing an example of a graft structure of a polymer.

Preferred embodiments of the present invention are described below.
[Laminate]
As shown in FIG. 1, a laminate 10 which is a preferred embodiment of the laminate of the present invention includes a cellulose ester-containing layer 11 (hereinafter, also simply referred to as “cellulose ester layer”) and a cellulose ester layer 11. A layer 12 containing a block polymer and / or a graft polymer including a polyamide chain having a structural unit represented by the following general formula (1), which is arranged adjacent to at least one surface of It is also referred to as a “polyamide chain-containing polymer layer”.
In the present invention, “adjacently arranged” means a form in which a cellulose ester layer and a polyamide chain-containing polymer layer are directly laminated (directly laminated). That is, there is no adhesive layer between the cellulose ester layer and the polyamide chain-containing polymer layer so that the two layers are in close contact with each other.

In the laminate of the present invention, the polyamide chain-containing polymer layer 12 may be provided on one side of the cellulose ester layer 11 as shown in FIG. The form provided with the polyamide chain containing polymer layer 12 may be sufficient. More preferably, the laminate of the present invention has a form in which the polyamide chain-containing polymer layer 12 is provided on one side of the cellulose ester layer 11.
Further, the laminate of the present invention may have a form in which two or more polyamide chain-containing polymer layers having different compositions are provided on the cellulose ester layer. When two or more polyamide chain-containing polymer layers are formed, the cellulose ester layer may be provided with two or more polyamide chain-containing polymer layers on one side, and two or more polyamide chains are provided on both sides of the cellulose ester layer. The form which provided the containing polymer layer may be sufficient.
Moreover, the laminated body of this invention may have the various functional layers (not shown) specialized for a specific function other than a cellulose-ester layer and a polyamide chain containing 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.

<Polyamide chain-containing polymer layer>
The polyamide chain-containing polymer layer constituting the laminate of the present invention will be described.
In the present invention, the “polyamide chain-containing polymer layer” means a layer containing a polyamide chain-containing polymer to be described later in an amount of 50% by mass or more. The content of the polyamide chain-containing polymer in the polyamide chain-containing 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 polyamide chain-containing polymer, the better the adhesion with the cellulose ester layer, and the moisture permeability can be suppressed. Therefore, the content of the polyamide chain-containing polymer in the polyamide chain-containing polymer layer may be 100% by mass, and is usually 99% by mass or less. When the content of the polyamide chain-containing polymer in the polyamide chain-containing polymer layer is not 100% by mass, the balance can contain various additives described later.
Two or more polyamide chain-containing polymers may be used in combination in the polyamide chain-containing polymer layer. That is, you may use together the polyamide chain containing polymer from which the composition ratio of a structural unit, a structure, and / or molecular weight differ in a polyamide chain containing polymer layer. When two or more types of polyamide chain-containing polymers are used in combination, the content of the polyamide chain-containing polymer in the polyamide chain-containing polymer layer described above is the total amount of the two or more types of polyamide chain-containing polymers.

− Polyamide chain-containing polymer −
The polyamide chain-containing polymer constituting the polyamide chain-containing polymer layer is a block polymer or a graft polymer, and a block polymer and a graft polymer may be used in combination. In these polymer structures, a polyamide chain having one or more structural units (repeating units) represented by the following general formula (1) is included. In addition, * shown in the formula in this specification shows the coupling | bond part (connection part) for incorporating in a polymer structure.

In General Formula (1), X ¹ and X ^{2 each} represent an amide bond (—NH—CO— or —CO—NH—).

L ¹ represents a single bond or a divalent group. The divalent group that can be taken as L ¹ is not particularly limited as long as the effects of the present invention are not impaired, and the molecular weight is preferably 12 to 800, more preferably 12 to 500. The divalent group that can be taken as L ¹ is preferably a divalent group having an aliphatic ring having 40 to 500 carbon atoms, and more preferably a divalent group consisting of an aliphatic ring having 40 to 300 carbon atoms. This aliphatic ring may be a monocyclic structure or a condensed polycyclic structure. When the aliphatic ring has a condensed polycyclic structure, a form in which an aromatic ring or an aliphatic ring is condensed to an aliphatic ring having a monocyclic structure is exemplified. Ring constituting an aliphatic ring (when the aliphatic ring is a monocyclic structure, it means this monocycle, and when the aliphatic ring is a condensed polycyclic structure, it means each ring constituting the condensed polycyclic structure) .) Is preferably a 3- to 8-membered ring, more preferably a 4- to 6-membered ring. The aliphatic ring may have a substituent, and the substituent is an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and still more preferably 1 to 3 carbon atoms). ) Is preferred.
From the viewpoint of further suppressing moisture permeability and imparting appropriate flexibility or rigidity, L ¹ is preferably represented by any of the following formulas (1-a) to (1-p), More preferably, it is represented by any of the following formulas (1-a) to (1-j), and the following formulas (1-b), (1-c), (1-e), (1-f) , (1-g) or (1-i), particularly preferably represented by the following formula (1-b), (1-c) or (1-e).

R ^{1 to} R ³ represent an alkyl group, an alkenyl group, an aryl group, an alkoxy group, a hydroxy group, a carboxy group, or a halogen atom.
The alkyl group that can be employed as R ^{1 to} R ³ preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 5 carbon atoms. This alkyl group may be linear or branched. The alkyl group preferably has a halogen atom (preferably a fluorine atom) as a substituent. The alkyl group that can be adopted as R ^{1 to} R ³ is more preferably methyl, ethyl, or trifluoromethyl.
The alkenyl group that can be employed as R ^{1 to} R ³ preferably has 2 to 15 carbon atoms, more preferably 2 to 10 carbon atoms, and still more preferably 2 to 5 carbon atoms. This alkenyl group may be linear or branched. Preferred examples of the alkenyl group include vinyl, allyl and butenyl groups.
An aryl group which may take as R ¹ to R ^3, it is preferably 6 to 30 carbon atoms, more preferably 6 to 15, 6 to 10 is more preferred. This aryl group is particularly preferably phenyl.
The alkoxy group that can be employed as R ^{1 to} R ³ preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 5 carbon atoms. This alkoxy group may be linear or branched. Preferred examples of this alkoxy group include methoxy, ethoxy, propyloxy and butoxy.
The halogen atom which can be taken as R ^{1 to} R ³ is, for example, a fluorine atom, a bromine atom, a chlorine atom or an iodine atom, and among them, a fluorine atom is preferable.
n ¹ ~n ³ is an integer from 0 to 4, preferably an integer of 0 to 3, more preferably an integer of 0 to 2, 0 or 1 is more preferred.

In the three benzene rings shown in the general formula (1), it is preferable that two linking sites of each benzene ring to be incorporated into the polyamide chain are located in the para position or the meta position. That is, for the benzene ring shown on the left side of the general formula (1), the positional relationship of the linking site with X ^{1 of} this benzene ring with respect to the linking site indicated with * of this benzene ring is para- or meta. The benzene ring shown at the center in the general formula (1) has a positional relationship of the linking site with L ^{1 of} this benzene ring relative to the linking site with X ¹ of this benzene ring. The para-position or the meta-position is preferred, and for the benzene ring shown on the right side in the general formula (1), the linking site with X ^{2 of} this benzene ring with respect to the linking site with L ¹ of this benzene ring It is preferable that the positional relationship is para-position or meta-position.

The polyamide chain preferably contains 30% by mass or more, more preferably 40% by mass or more, and more preferably 50% by mass or more of the structural unit represented by the general formula (1) in the polyamide chain. More preferably, it is more preferably 70% by mass or more, further preferably 80% by mass or more, and particularly preferably 90% by mass or more. Moreover, it is also preferable that the said polyamide chain is a form which consists of a structural unit represented by the said General formula (1).
When the polyamide chain is not in the form of the structural unit of the general formula (1), the structural unit constituting the remainder excluding the structural unit of the general formula (1) in the polyamide chain is an amide bond and a polymer main chain. There is no particular limitation as long as it is incorporated therein. For example, the remainder excluding the structural unit of the general formula (1) can be composed of one or more structural units (repeating units) represented by the following general formula (3).

In General Formula (3), X ³ and X ⁴ represent an amide bond (—NH—CO— or —CO—NH—).
R ^c and R ^d are both synonymous with R ¹ in the general formula (1), and their preferred forms are also the same. n ³ and ^{n 4} is an integer from 0 to 4, preferably an integer of 0 to 3, more preferably an integer of 0 to 2, 0 or 1 is more preferred.

  When the polyamide chain has a structural unit of the general formula (1) and a structural unit other than the structural unit of the general formula (1), each structural unit may be present in a block form in the polyamide chain, and randomly May be present.

  Although the preferable specific example of the structural unit which comprises the said polyamide chain, or the combination of a structural unit is shown below, this invention is not limited to these.

The polyamide chain-containing polymer is a block polymer or a graft polymer as described above, and has a partial structure composed of a polyamide chain having the structural unit of the general formula (1) and a partial structure other than the polyamide chain.
In the present specification, the term “block structure” is used in a broader sense than usual as described later. With this in mind, first, a schematic diagram of the basic structure of the block polymer and graft polymer is shown. The description will be given with reference. In the following description, in order to facilitate understanding, a polymer composed of 1 to 4 kinds of structural units A to D will be described as a model.

  In the following description, “main chain direction” means a direction in which each repeating unit is connected in each partial structure forming a polyamide chain-containing polymer.

(Block polymer)
The block polymer is a polymer having a block structure. The block structure refers to a structure in which the main chain directions of the partial structures composed of a single structural unit are only a single linear direction in the polymer chain. The block structure is composed of two or more structural units.

When the polyamide chain-containing polymer is a block polymer, examples of the block structure include the structures shown in FIGS. 3A to 3E (sometimes referred to as FIG. 3 together). In FIG. 3, A to D represent different structural units (same in FIGS. 4 and 5).
The block structure shown in FIG. 3A is a block structure (A-B type) in which a partial structure composed of the structural unit A and a partial structure composed of the structural unit B are combined in a single linear direction within the polymer chain.
The block structure shown in FIG. 3B is a block structure (B-A-B type) in which a partial structure consisting of a structural unit B is bonded to both ends of a partial structure consisting of a structural unit A in a single linear direction within a polymer chain. ). The block structure shown in FIG. 3C has a partial structure composed of the structural unit B, a partial structure composed of the structural unit A, and a partial structure composed of the structural unit C as the third component in this order in the polymer chain. It is a block structure coupled in one linear direction. The block structure shown in FIG. 3D is the same as the block structure shown in FIG. 3C, in which the partial structure consisting of the structural unit C and the partial structure consisting of the structural unit D as the fourth component are combined in a single linear direction within the polymer chain. Block structure. The block structure shown in FIG. 3E is a block structure in which a partial structure composed of the structural unit A and a partial structure composed of the structural unit B are alternately repeated (coupled) twice in a single linear direction in the polymer chain. It is.

(Graft polymer)
The graft polymer is a polymer having a graft structure. The graft structure means one that satisfies both the following conditions (G-1) to (G-3).
(G-1) Another polymer PB ^G1 (also referred to as a branch polymer) consisting of one or more types of structural units with respect to the polymer PA ^G1 (also referred to as a trunk polymer) composed of one or more types of structural units Is a structure in which one or more are bonded.
(G-2) In the polymer chain, the main chain direction of the polymer PB ^G1 is different from the main chain direction of the polymer PA ^G1 .
(G-3) to the polymer ^{PB G1,} polymer ^{PB G2} having a main chain direction different from the main chain direction of the polymer ^{PB G1} is not bound.

The number of the polymer PB ^G1 bonded to the polymer PA ^G1 may be one or more, and is appropriately determined according to characteristics required for the polyamide chain-containing polymer. In the present invention, for example, the number of the polymer PB ^G1 bonded to the polymer PA ^G1 can be 1 to 200, preferably 1 to 100, and more preferably 1 to 50.

Examples of the graft structure include the structures shown in FIGS. 4A to 4E (sometimes collectively referred to as FIG. 4).
The graft structure shown in FIG. 4A is a graft structure in which three polymers PB ^G1 (branched polymer) composed of structural unit B are bonded to polymer PA ^G1 (trunk polymer) composed of structural unit A.
The graft structure shown in FIGS. 4B to 4E is a graft structure having the structural unit C as the third component, the structural unit C and the structural unit D as the fourth component.
That is, the graft structure shown in FIG. 4B is a graft in which three polymers PB ^G1 (branched polymer) composed of structural unit B are bonded to random structure polymer PA ^G1 (trunk polymer) composed of structural unit A and structural unit C. Structure. The graft structure shown in FIG. 4C has two polymers PB ^G1-B composed of structural unit B and one polymer PB ^G1-C composed of structural unit C, compared to polymer PA ^G1 (trunk polymer) composed of structural unit A. This is a combined graft structure. The graft structure shown in FIG. 4D is a graft structure in which three polymers PB ^G1-BC having a random structure composed of structural units B and C are bonded to a polymer PA ^G1 (trunk polymer) composed of a structural unit A. In the graft structure shown in FIG. 4E, three polymers PB ^G1-CD having a block structure composed of structural units C and D are bonded to a polymer PA ^G1-AB (trunk polymer) having a random structure composed of structural units A and B. Graft structure.

  The graft polymer can be obtained by a conventional method. For example, it can be synthesized by a grafting through method, a grafting to method, or a grafting from method. For details, see, for example, Takeshi Endo, Mitsuo Sawamoto et al., “Synthesis of Polymers (above)-Radical Polymerization / Cationic Polymerization / Anionic Polymerization”, Kodansha, 2010, p60, p108-110 and p387-393. it can.

The graft structure described above can be confirmed as a particle shape by measuring the mean square turning radius <S ^ 2> from static light scattering measurement. The presence or absence of the block structure can be confirmed by nuclear magnetic resonance (NMR) measurement.
For the identification of each block structure and graft structure, refer to “Organic / Polymer Measurement Lab Guide for Young Researchers”, Kodansha, 2006.

In the above, the basic structure (general structure) of the block polymer and the graft polymer has been described using schematic diagrams. In the present invention, the term “block structure” has a broader meaning than the ordinary meaning described above. It is used in the meaning. That is, when assuming a polymer in which a polyamide chain (chain X) in which a plurality of types of structural units are linked in a random or block form and a partial structure (chain Y) other than the polyamide chain is linked, the chain X is In the present invention, the entire chain X is regarded as one partial structure constituting the block polymer. Similarly, when the chain Y has a structure in which a plurality of types of structural units are connected in a random or block form, the entire chain Y is regarded as one partial structure constituting the block polymer.
Therefore, in the present invention, the configurations shown in FIGS. 4A, 4B, and 4D can be seen together. In FIG. 4E, the trunk polymer shows a form of random copolymerization. In the present invention, this trunk polymer is considered as one partial structure constituting the block polymer. Further, in FIG. 4E, when both the partial structure composed of the structural unit C and the partial structure composed of the structural unit D are both polyamide chains or both chains other than the polyamide chain, the whole of these two partial structures is combined with the block polymer. Consider it as a single partial structure.
Therefore, in the following description, when it is referred to as “partial structure consisting of structural unit A”, this partial structure is a polyamide chain in which a plurality of types of structural units are connected in a random or block form, or a plurality of types of structural units. Means that the chain is a chain other than a polyamide chain linked in a random or block form. The same applies to “a partial structure composed of the structural unit B”, “a partial structure composed of the structural unit C”, and “a partial structure composed of the structural unit D”. Based on this premise, an example of the correspondence relationship between the embodiment of FIGS. 3 and 4 and the structure of the polyamide chain-containing polymer will be described below.

  In the structures of FIGS. 3A, 3B and 3E, one of the partial structure consisting of the structural unit A and the partial structure consisting of the structural unit B is a polyamide chain having the structural unit of the general formula (1), The other is a chain other than the polyamide chain.

In the structure of FIG. 3C, for example, the partial structure composed of the structural unit A is a polyamide chain having the structural unit of the general formula (1), and both the partial structure composed of the structural unit B and the partial structure composed of the structural unit C are both. The form which is chains other than a polyamide chain can be assumed. Moreover, the partial structure consisting of the structural unit A is a chain other than the polyamide chain, and the partial structure consisting of the structural unit B and the partial structure consisting of the structural unit C are both polyamide chains having the structural unit of the general formula (1). A form can be assumed.
In the case where both the partial structure composed of the structural unit A and the partial structure composed of the structural unit B are polyamide chains, that is, a structure in which two polyamide chains having different structural units are connected, the portion composed of the structural unit A The whole of the structure and the partial structure composed of the structural unit B is viewed as one partial structure constituting the block polymer. Similarly, when both the partial structure consisting of the structural unit A and the partial structure consisting of the structural unit C are polyamide chains, the whole of the partial structure consisting of the structural unit A and the partial structure consisting of the structural unit C is blocked. It is considered as one partial structure constituting the polymer. In these forms, the remaining partial structure is a chain other than the polyamide chain.
In the case where both the partial structure consisting of the structural unit A and the partial structure consisting of the structural unit B are chains other than the polyamide chain, that is, a structure in which two chains other than the polyamide chain are connected. The whole of the partial structure composed of the structural unit A and the partial structure composed of the structural unit B is regarded as one partial structure constituting the block polymer. Similarly, when the partial structure consisting of the structural unit A and the partial structure consisting of the structural unit C are both chains other than the polyamide chain, the total of the partial structure consisting of the structural unit A and the partial structure consisting of the structural unit C is combined. Is considered as one partial structure constituting the block polymer. In these forms, the remaining partial structure is a polyamide chain having the structural unit of the general formula (1).

In the structure of FIG. 3D, at least one partial structure is a polyamide chain having the structural unit of the general formula (1) among the partial structures composed of the structural units A to D, and at least one part. The form whose structure is chains other than a polyamide chain can be assumed.
Further, when the adjacent partial structures are both polyamide chains, or when they are both chains other than the polyamide chain, the entire adjacent partial structures are regarded as one partial structure constituting the block polymer. In addition, when all three consecutive partial structures are polyamide chains, or when all three consecutive partial structures are chains other than polyamide chains, the entire three partial structures consecutively connected are Considered as one partial structure constituting the block polymer.

In the structures of FIGS. 4A, 4B, and 4D, either the backbone polymer or the branch polymer is a polyamide chain having the structural unit of the general formula (1), and the other is a chain other than the polyamide chain.
In the structure of FIG. 4C, one or two of the trunk polymer, the branched polymer composed of the structural unit B, and the branched polymer composed of the structural unit C are polyamide chains having the structural unit of the general formula (1). The other structural unit is a partial structure other than the polyamide chain.
In FIG. 4E, one or two of the backbone polymer, the partial structure consisting of the structural unit C of the branched polymer, and the partial structure consisting of the structural unit D of the branched polymer are structural units of the general formula (1). And the remainder is a polymer structure other than the polyamide chain. However, when the partial structure consisting of C and the partial structure consisting of D are both polyamide chains, or both are chains other than the polyamide chain, the total of the partial structure consisting of C and the partial structure consisting of D is It is considered as one partial structure constituting the branched polymer.

  The above examples illustrate examples of the polyamide chain-containing polymer used in the present invention, and the polyamide chain-containing polymer used in the present invention is not limited to the above forms except as defined in the present invention. Absent. That is, the polyamide chain-containing polymer used in the present invention may be composed of a polyamide chain having the structural unit of the general formula (1) and a polymer chain other than the polyamide chain. However, the polyamide chain-containing polymer used in the present invention is not a star structure or a hyperbranched structure, and the polyamide chain-containing polymer used in the present invention has a block structure or a graft structure as described above.

Subsequently, a structure other than the polyamide chain (hereinafter, also referred to as “NPA structure”) constituting the polyamide chain-containing polymer will be described.
The NPA structure is not particularly limited as long as it is composed of a polymer chain other than the polyamide chain. The polymer chain which has 2 or more types can be mentioned.

  The styrene compound is not particularly limited as long as it is a structural unit forming a styrene polymer. Specific examples of the styrene compound 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-trifluoromethyl Styrene, 4-acetoxystyrene, 4-phenylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, vinylanthracene, α-methylstyrene, β-methylstyrene, 2-methyl-1-phenylpropene, stilbene, divinylbenzene, di Isopropenylbenzene, 4- Examples thereof include isopropenyl toluene, cinnamonitrile, and 1,1-diphenylethylene.

The (meth) acrylic acid ester compound is more preferably a (meth) acrylic acid alkyl ester compound or a (meth) acrylic acid cycloalkyl ester compound. The alkyl group of this (meth) acrylic acid alkyl ester compound may be linear or branched. 1-30 are preferable, as for carbon number of the alkyl group which comprises a (meth) acrylic-acid alkylester compound, 1-20 are more preferable, 1-18 are still more preferable, and 1-16 are especially preferable. 3-30 are preferable, as for carbon number of the cycloalkyl group of a (meth) acrylic-acid cycloalkyl ester compound, 4-20 are more preferable, 5-18 are still more preferable, and 6-16 are especially preferable.
Specific examples of the (meth) acrylic acid ester compound and the (meth) acrylic acid cycloalkyl ester compound include, for example, propyl acrylate, isopropyl acrylate, n-butyl acrylate, iso-butyl acrylate, sec-butyl acrylate. Tert-butyl acrylate, hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, hexyl methacrylate And cyclohexyl methacrylate, 2-ethylhexyl methacrylate or dodecyl methacrylate.

  Examples of the olefin compound include ethylene, propylene, isoprene, butadiene, isobutene, and vinyl chloride. In the present invention, even if the olefin compound can be interpreted as a vinylidene compound, when the structure is composed of only a carbon atom and a hydrogen atom, it is classified as an olefin compound instead of a vinylidene compound.

  Examples of the vinylidene compound include vinylidene chloride, vinylidene fluoride, tetrafluoroethylene, trifluoroethylene chloride, and perfluoroalkoxytrifluoroethylene.

  From the viewpoint of increasing the solubility of the polyamide chain-containing polymer in the solvent, the NPA structure preferably has one or more structural units represented by the following general formula (2).

R ⁴ represents an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 3 to 20 carbon atoms.
Alkyl group having 1 to 20 carbon atoms which can be taken as R ⁴ may have either linear or branched. 1-15 are preferable, as for carbon number of this alkyl group, 1-12 are more preferable, 1-10 are more preferable, 1-8 are more preferable, and 1-6 are more preferable.
In addition, when the alkyl group having 1 to 20 carbon atoms that can be employed as R ⁴ has a substituent, the substituent is a cycloalkyl group (preferably having 5 to 8 carbon atoms), an aryl group, a hydroxy group, or an alkoxy group. , An acyl group, an acyloxy group, a carboxy group, an alkoxycarbonyl group, a halogen atom, a heterocyclic group (preferably having 5 or 6 ring atoms, preferably 1 to 3 heteroatoms in the ring atoms), Or ^** -OC (= O) -NH- [phenyl group] (** represents a bond to an alkyl group), preferably a cycloalkyl group or ^** -OC (= O)- NH- [phenyl group] is more preferable. ^** represents a bond to an alkyl group.
The cycloalkyl group having 3 to 20 carbon atoms that can be employed as R ⁴ has more preferably 4 to 15 carbon atoms, and further preferably 5 to 12 carbon atoms. It is also preferable that the cycloalkyl group having 3 to 20 carbon atoms that can be adopted as R ⁴ is a form in which the substituents of the cycloalkyl group are connected to each other to form a condensed ring.
Also, if the cycloalkyl group having 3 to 20 carbon atoms which can be taken as R ⁴ has a substituent, it is preferable that the substituent of an alkyl group (which may have a either linear or branched), the number of carbon atoms It is preferably an alkyl group of 1 to 4, more preferably methyl, ethyl or t-butyl.

In general formula (2), R ⁵ represents a hydrogen atom or an alkyl group.
The alkyl group that can be adopted as R ⁵ may be linear or branched. 1-10 are preferable, as for carbon number of this alkyl group, 1-5 are more preferable, and 1-3 are more preferable. R ⁵ is more preferably methyl or ethyl, and even more preferably methyl.
R ⁵ is preferably a hydrogen atom or methyl.

R ⁶ and R ⁷ represent a hydrogen atom, an alkyl group, an aryl group or an alkoxycarbonyl group.
The alkyl group which can be taken as R ⁶ and R ⁷ may be linear or branched. 1-10 are preferable, as for carbon number of this alkyl group, 1-5 are more preferable, and 1-3 are more preferable. The alkyl group that can be taken as R ⁶ and R ⁷ is more preferably methyl or ethyl, and further preferably methyl.
The aryl group that can be employed as R ⁶ and R ⁷ 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.
The alkoxycarbonyl group that can be employed as R ⁶ and R ⁷ preferably has 2 to 10 carbon atoms, and more preferably 2 to 5 carbon atoms. The alkoxycarbonyl group which can be taken as R ⁶ and R ⁷ is more preferably methoxycarbonyl or ethoxycarbonyl.

The structural unit represented by the general formula (2) is preferably a structural unit represented by the following general formula (2-1).

In General Formula (2-1), R ⁴ and R ⁵ have the same meanings as R ⁴ and R ⁵ in General Formula (2), respectively, and preferred forms are also the same.

The structural unit constituting the NPA structure may have a solubility parameter δt of 18 to 26 from the viewpoint of dissolving the polyamide chain-containing polymer at a higher concentration in the coating solution for forming the polyamide chain-containing polymer layer. Preferably, it is 19-23. Solubility parameter δt is literature ^{"Properties of Polymers 3 rd, ELSEVIER} , (1990)" The 214-220 pages, means δt obtained for Amorphous Polymers according to "2) Method of Hoy (1985,1989)" column And calculated according to the description in the above column of the above document. In the present invention, the unit of the solubility parameter δt is “(cal / cm ³ ) ^1/2 ”.

  In the NPA structure, the content of the structural unit represented by the general formula (2) is preferably 10% by mass or more, more preferably 15% by mass or more, further preferably 25% by mass or more, and further 35% by mass or more. Preferably, 50% by mass or more is more preferable, 60% by mass or more is more preferable, 70% by mass or more is further preferable, 80% by mass or more is further preferable, and 90% by mass or more is particularly preferable. In addition, an embodiment in which the NPA structure is composed of a structural unit represented by the general formula (2) is also preferable.

  In the polyamide chain-containing polymer, the content of the polyamide chain having the structural unit of the general formula (1) is preferably 40% by mass or more, more preferably 60% by mass or more, and further preferably 70% by mass or more. And it is preferable that the polymer chain which comprises the remainder (polymer chain) remove | excluding the said polyamide chain from the said polyamide chain containing polymer consists of a structural unit of General formula (2).

  Although the preferable specific example of the structural unit which comprises the said NPA structure is shown below, this invention is not limited to these.

The polyamide chain constituting the polyamide chain-containing polymer exhibits high packing properties due to hydrogen bonding, π-π stacking, and the like. Moreover, the laminated body of this invention takes the structure which laminated | stacked the cellulose ester film and the polymer layer which has the said polyamide chain directly, and is excellent also in the adhesiveness between layers. Therefore, the laminate of the present invention has the desired optical properties possessed by the cellulose ester film and further exhibits a high degree of moisture barrier performance. When the laminate of the present invention is used as a polarizing plate protective film, it is possible to effectively suppress the deterioration of the polarizer.
The polyamide chain has low solubility in a solvent due to the high packing property described above, and a melt film forming method must be applied to film formation using a polymer comprising the polyamide chain. However, in the present invention, the polyamide chain-containing polymer has a partial structure other than the polyamide chain. As a partial structure other than the polyamide chain, a structure that contributes to improvement in solubility in a solvent can be adopted, and the solvation of the polymer can be effectively increased. As a result, it is possible to form a solution film that is simpler and more energy efficient when forming the film. In the polyamide chain-containing polymer, the partial structure of the polyamide chain and other partial structures are unevenly distributed and are presumed to be able to effectively draw out the low moisture permeability of the polyamide chain. .

The weight average molecular weight (Mw) of the polyamide chain-containing polymer used in the present invention is preferably 5,000 or more, more preferably 15,000 or more, and more preferably 30,000 or more from the viewpoint of the film surface shape. More preferably. On the other hand, the weight average molecular weight of the polyamide chain-containing polymer used in the present invention is preferably 1,000,000 or less, more preferably 800,000 or less, and more preferably 500,000, from the viewpoint of film forming properties. Is more preferably 200,000 or less, and most preferably 150,000 or less.
The molecular weight can be measured by the method described in Examples described later.

  There is no restriction | limiting in particular in the film thickness of the said polyamide chain containing polymer layer, 1-25 micrometers is preferable, 1-20 micrometers is more preferable, and 1-15 micrometers is especially preferable.

<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 glucose unit which comprises cellulose and has β-1,4 bonds 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, wood pulp (hardwood pulp, conifer pulp), and the like. Any cellulose obtained from any raw material cellulose can be used, and in some cases, a mixture may be used. The raw material cellulose is, for example, Marusawa, Uda, “Plastic Materials Course (17) Fibrous Resin”, Nikkan Kogyo Shimbun (published in 1970), or Japan Institute of Invention and Technology 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, assuming that 3 is when all the hydroxy groups in the glucose molecule are all acylated.
The degree of substitution of cellulose acylate is described in Tezuka et al., Carbohydrate. Res. , 273, 83-91 (1995), or according to the method prescribed in ASTM-D817-96.

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

  There is no restriction | limiting in particular in the acyl group of the cellulose acylate used for this invention, The form which has 1 type of acyl groups may be sufficient, and the form which has 2 or more types of acyl groups may be sufficient. The cellulose acylate that can be used in the present invention preferably has an acyl group having 2 or more carbon atoms as a substituent. The acyl group having 2 or more carbon atoms is not particularly limited, and may be an aliphatic acyl group or an aromatic acyl group. Specific examples of the acyl group having 2 or more carbon atoms include acetyl, propionyl, butanoyl, heptanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, isobutanoyl, tert-butanoyl, 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, still more preferably 2.30 to 3.00, and further preferably 2.30 to 2.97. Preferably, it is 2.30-2.95.

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

  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 cellulose ester or cellulose acylate used in the present invention preferably has a polymerization degree of 250 to 800, more preferably 300 to 600. The cellulose ester or cellulose acylate used in the present invention has a number average molecular weight of preferably 40000 to 230,000, more preferably 60000 to 230,000, and most preferably 75000 to 200000.
The degree of polymerization can be determined by dividing the number average molecular weight measured in terms of polystyrene by gel permeation chromatography (GPC) by 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.) corresponding to the desired acyl group or an acid anhydride (acetic anhydride, propionic anhydride, butyric anhydride, etc.) of 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 and the like) can be used in combination with the cellulose ester as long as the effects of the present invention are not impaired. The content of the other resin in the cellulose ester film is preferably 40% by mass or less, more preferably 30% by mass or less, 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 formation of the cellulose ester layer is not particularly limited. For example, the cellulose ester layer is preferably formed by a melt film forming method or a solution film forming method (solvent casting method). In consideration of volatilization and / or decomposition of the additive, More preferably, it is formed by a film forming method. Examples of polymer film production using the solvent cast method are described in US Pat. Nos. 2,336,310, 2,367,603, 2,492,078, and 2,492,977. 2,492,978, 2,607,704, 2,739,069 and 2,739,070, British Patent Nos. 640731 and 736892. Nos. 45-4554, 49-5614, JP-A-60-176834, JP-A-60-203430, and JP-A-62-115035 can be referred to. . 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, JP-A-4284221, JP-A-4-298310, JP-A-11-48271, and the like. be able to.

(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 or a coating method, In particular, it is particularly preferable to use a co-casting (also referred to as 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 a casting die, and if necessary, the dope is sequentially cast and 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 polymer film is dried, it can be stretched using a stretching machine (preferably uniaxial stretching using a long stretching machine).
In the case of stretching in the MD direction, for example, it can be performed by adjusting the speed of the film transport roller to make the winding speed faster than the film peeling speed.

  When the laminate of the present invention is used as a protective film for a polarizer (also referred to as a polarizing plate protective film), in order to suppress light leakage when the polarizing plate is viewed obliquely, the transmission axis of the polarizer and the cellulose ester An embodiment in which 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, the stretching may be performed in a state including the residual solvent amount, and the residual solvent amount = (residual volatile matter mass / heat-treated film mass) × 100% is stretched in a state of 0.05 to 50%. It is preferable to do. More preferably, the residual solvent is stretched 5 to 80% in a state of 0.05 to 5%.

<Additives>
The 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, and matting agents. About these, the description of paragraph number [0062]-[0097] of Unexamined-Japanese-Patent No. 2012-155287 can be referred to, These content is integrated in this-application specification. Examples of the additive include a peeling accelerator, an organic acid, and a polyvalent carboxylic acid derivative. Regarding these, the description in paragraphs [0212] to [0219] of International Publication No. WO2015 / 005398 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 30 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 WO 2015/005398, 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 the suppression of the precipitation of the plasticizer. It is preferable that it is 2-15 mass parts, and it is still more preferable to set it as 5-15 mass parts.
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, the description of paragraphs [0143] to [0165] of International Publication No. 2015/005398 can be referred to, and the contents thereof are incorporated in the present specification.

(Radical scavenger)
One preferred additive may include a radical scavenger. Regarding the radical scavenger, the description 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. Regarding 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. About the barbituric acid compound which can be used for the said cellulose-ester layer, the description of international publication 2015/005398 Paragraph [0029]-[0060] can be referred to, These content is integrated in this-application specification.

<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 methods 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 alkaline solution temperature is preferably in the range of room temperature to 90 ° C, and 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 or JP-A-6-118232 may be performed.

1-80 micrometers is preferable, as for the film thickness of the said cellulose-ester layer, 1-60 micrometers is more preferable, and 3-60 micrometers is still more preferable.
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. The thickness of the skin layer A and skin layer B in the case of a three-layer structure 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 three-layer structure. Say.

[Manufacturing method of laminate]
The manufacturing method of the laminated body of this invention is demonstrated.
The manufacturing method of the laminated body of this invention is not specifically limited, A well-known method is employable. In addition to the melt film forming method or the solution film forming method, a cellulose ester layer can be produced by a method described later, and then a polyamide chain-containing 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 coating method is used, a coating liquid will not be specifically limited if a polyamide chain containing polymer is melt | dissolved in a suitable solvent by a suitable density | concentration, Coating conditions and film formation The conditions are not particularly limited.
As the melt film forming method, a production method such as a T-die method is preferably used, and a simultaneous coextrusion method is particularly preferably used. As the solution casting method, a lamination casting method such as the above co-casting method, sequential casting method or coating method is preferably used, and a simultaneous co-casting method (also referred to as simultaneous multi-layer co-casting) method is particularly used. Is particularly preferable from the viewpoints of stable production and production cost reduction.

<Physical properties or characteristics of the laminate>
The laminate of the present invention preferably has the following physical properties or characteristics.

(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.
A haze is measured according to JIS K7136 (2000) using a haze meter (HGM-2DP, Suga Test Instruments Co., Ltd.) in an environment of 25 ° C. and a relative humidity of 60% using a laminate 40 mm × 80 mm.

(Film thickness)
Although the film thickness of the laminated body of this invention can be suitably determined according to a use, it can be 5-100 micrometers, for example. When the thickness is 5 μm or more, the handling property when producing a web-like film is improved, which is preferable. Moreover, by setting it as 100 micrometers or less, it becomes easy to respond to a humidity change and it becomes easy to maintain an optical characteristic.
In order to meet the above-described demand for thinning of the image display device, the laminate is preferably thinned. In this case, the thickness of the laminate is preferably, for example, 8 to 80 μm, and 10 to 70 μm. Is more preferable.

(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 less than 1600g ^/ m 2 ^/ day, more preferably less than 1000g ^/ m 2 ^/ day, more preferably less than 500g ^/ m 2 ^/ day Particularly preferably, it is less than 250 g / m ² / day. By controlling the moisture permeability of the laminated body within the above range, the liquid crystal display device equipped with the laminated body of the present invention is warped at normal temperature, high humidity and high temperature and high humidity, and / or when black is displayed. Display unevenness can be suppressed.

(Moisture content)
The moisture content of the laminate (equilibrium moisture content) is 25 ° C., regardless of the film thickness, so as not to impair the adhesion with a hydrophilic thermoplastic resin such as polyvinyl alcohol when used as a protective film for a polarizing plate. The moisture content at a relative humidity of 80% is preferably 0 to 4% by mass. The water 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 4% by mass or less, the dependence of retardation on humidity changes does not become too large, and the display unevenness of the liquid crystal display device during black display after normal temperature, high humidity, and high temperature and high humidity environments is suppressed. This is also preferable.
The moisture content 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. That is, the polarizing plate of the present invention can be suitably used as an optical film or a polarizing plate protective film. Usually, a polarizing plate in which both surfaces of a polarizer are sandwiched between the laminates of the present invention and both surfaces are protected 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 performed. 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 is in a form in which a polyamide chain-containing 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 side of the polyamide chain-containing polymer layer, or the cellulose ester layer It may be on the side. From the viewpoint of further enhancing the effects of the present invention, it is preferable to directly bond the polyamide chain-containing polymer layer side with a 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 the range of ± 10 ° from the strict angle with respect to parallel, orthogonal and 45 °, respectively, and the error from the strict angle is preferably within the range of ± 5 °, and within the 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. Particularly preferred adhesives are aqueous solutions of fully saponified polyvinyl alcohol or UV curable adhesives.

  The polarizing plate is comprised with the polarizer and the protective film which protects both surfaces, and it is preferable to make at least 1 sheet of a protective film into the laminated body of this invention. 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.

[Optical properties of polarizing plate]
<Degree of polarization>
In the polarizing plate of the present invention, the degree of polarization is preferably 95.0% or more, more preferably 98% or more, and most preferably 99.5% or more.

  In the present invention, the degree of polarization of the polarizing plate can be measured using an automatic polarizing film measuring device VAP-7070 manufactured by JASCO Corporation. More specifically, it can be measured by the method described in the Example column.

<Change in polarization degree>
The polarizing plate of the present invention is excellent in durability under wet heat aging conditions. For this reason, the amount of change in the degree of polarization before and after the polarizing plate durability test described later is small.
The polarizing plate of the present invention measures orthogonal transmittance and parallel transmittance using an automatic polarizing film measuring device VAP-7070 manufactured by JASCO Corporation, and calculates the degree of polarization. It is preferable that the amount of change in polarization degree is less than 3% when stored for 500 hours in an environment.

<Other characteristics>
Other preferable optical characteristics of the polarizing plate of the present invention are described in paragraphs [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 laminate 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 QuantBandS). 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 laminate 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>

A 500 mL three-necked flask equipped with a thermometer, stirring blades, and reflux ring was charged with 20.0 g of methyl ethyl ketone and 1.08 g of 3-mercapto-1,2-propanediol, and stirred at 70 ° C. under a nitrogen stream. Separately, in a 100 mL Erlenmeyer flask, 50.1 g of methyl methacrylate, 0.230 g of dimethyl 2,2′-azobisisobutyrate and 30.0 g of methyl ethyl ketone were weighed and mixed to obtain a monomer composition (solution). Prepared.
Next, the monomer composition was dropped into methyl ethyl ketone stirred at 70 ° C. at a rate of 0.62 mL / min. A chemical pump was used for dripping. The reaction solution after completion of the dropwise addition was further reacted at 80 ° C. for 2 hours, and then 0.02 g of dimethyl 2,2′-azobisisobutyrate was added and stirred for 3 hours. After completion of the reaction, the reaction solution was allowed to cool to room temperature, diluted with 170 g of methyl ethyl ketone, and reprecipitated with a mixed solution of 2.5 L of methanol and 1.3 L of water to obtain a white precipitate. The obtained white precipitate was filtered off and dried at 50 ° C. overnight to obtain the desired product.

  In a 500 mL three-necked flask equipped with a thermometer, a stirring blade and a reflux ring, 56 g of N-methylpyrrolidone, 3.0 g of the diol synthesized above, 7.0 g of 2,2′-bis (trifluoromethyl) benzidine, Triethylamine (0.1 g) was charged and stirred at 40 ° C. under a nitrogen stream to completely dissolve the solution. After returning the internal temperature to room temperature, 5.44 g of isophthalic acid chloride was added in portions and stirred at room temperature for 4 hours. After completion of the reaction, the internal temperature was adjusted to 40 ° C., 66.8 μL of acetyl chloride was added, and the mixture was stirred at 60 ° C. for 1 hour. The reaction solution was allowed to cool to room temperature and reprecipitated with a mixed solution of 2.2 L of methanol and 0.6 L of water to obtain a white precipitate. The obtained white precipitate was filtered off and dried at 190 ° C. to obtain a polymer P-1 as a graft polymer.

<Synthesis Example 2: Synthesis of Polymer P-2>

A 500 mL three-necked flask equipped with a thermometer, stirring blades, and reflux ring was charged with 20.0 g of 1-methoxy-2-propanol and 0.772 g of 2-aminoethanethiol and stirred at 70 ° C. under a nitrogen stream. . Separately, 50.1 g of methyl methacrylate, 0.230 g of dimethyl 2,2′-azobisisobutyrate and 30.0 g of 1-methoxy-2-propanol were weighed into a 100 mL Erlenmeyer flask and mixed to prepare a monomer. A composition (solution) was prepared.
Next, the monomer composition was dropped into methyl ethyl ketone stirred at 70 ° C. at a rate of 0.62 mL / min. A chemical pump was used for dripping. The reaction solution after completion of the dropwise addition was further reacted at 80 ° C. for 2 hours, and then 0.02 g of dimethyl 2,2′-azobisisobutyrate was added and stirred for 3 hours. After completion of the reaction, the reaction solution was allowed to cool to room temperature, diluted with 170 g of 1-methoxy-2-propanol, and reprecipitated with a mixed solution of 2.5 L of methanol and 1.3 L of water to obtain a white precipitate. The obtained white precipitate was filtered off and dried at 50 ° C. overnight to obtain the desired product.

  In a 500 mL three-necked flask equipped with a thermometer, a stirring blade, and a reflux ring, 56 g of N-methylpyrrolidone, 3.0 g of the amine synthesized above, 7.0 g of 2,2′-bis (trifluoromethyl) benzidine, Triethylamine (0.1 g) was charged and stirred at 40 ° C. under a nitrogen stream to completely dissolve the solution. After returning the internal temperature to room temperature, 5.40 g of isophthalic acid chloride was added in portions and stirred at room temperature for 4 hours. After completion of the reaction, the internal temperature was adjusted to 40 ° C., 66.8 μL of acetyl chloride was added, and the mixture was stirred at 60 ° C. for 1 hour. The reaction solution was allowed to cool to room temperature and reprecipitated with a mixed solution of 2.2 L of methanol and 0.6 L of water to obtain a white precipitate. The obtained white precipitate was filtered off and dried at 190 ° C. to obtain a polymer P-2 as a block polymer.

<Synthesis Examples 3-7, 9 and 10: Synthesis of Polymers P-3 to P-7, Polymer P-9 and Polymer P-10>
In the same manner as in Synthesis Example 2, block polymers (Polymers P-3 to P-7, Polymer P-9, and Polymer P-10) shown in Table 1 below were obtained. Similar to the polymer P-2 obtained in Synthesis Example 2, these block polymers are composed of one partial structure of a polyamide chain and one partial structure composed of a chain other than the polyamide chain.
In the polymer P-4, the molar ratio of the two structural units shown in the polyamide chain A-4 is 1: 1.

<Synthesis Example 8: Synthesis of Polymer P-8>
In the same manner as in Synthesis Example 1, a graft polymer (Polymer P-8) shown in Table 1 below was obtained. In the polymer P-8, the polyamide chain constitutes the main chain, and the polymethacrylate methyl chain constitutes the graft chain.

<Comparative Synthesis Example 1: Synthesis of Comparative Polymer HP-1>

  In a 500 mL three-necked flask equipped with a thermometer, a stirring blade and a reflux ring, 56 g of N-methylpyrrolidone, 3.0 g of the amine synthesized above, 7.0 g of 4,4′-methylenebis (2-methylcyclohexylamine) Then, 3.3 g of triethylamine was charged and stirred at 40 ° C. under a nitrogen stream to complete dissolution. After returning the internal temperature to room temperature, 6.09 g of isophthalic acid chloride was added in portions and stirred at room temperature for 4 hours. After completion of the reaction, the internal temperature was adjusted to 40 ° C., 66.8 μL of acetyl chloride was added, and the mixture was stirred at 60 ° C. for 1 hour. The reaction solution was allowed to cool to room temperature and reprecipitated with a mixed solution of 2.2 L of methanol and 0.6 L of water to obtain a white precipitate. The obtained white precipitate was filtered off and dried at 190 ° C. to obtain a polymer HP-1 as a block polymer.

<Comparative Synthesis Example 2: Synthesis of Comparative Polymer HP-2>
A 500 mL three-necked flask equipped with a thermometer, stirring blades, and reflux ring was charged with 172 mL of N-methylpyrrolidone and 17.3 g of 1,1-bis (4-aminophenyl) cyclohexane and stirred at room temperature under a nitrogen stream. And completely dissolved. 13.2 g of isophthalic acid chloride was added in portions and stirred at room temperature for 8 hours. After completion of the reaction, 0.51 g of acetyl chloride was added and stirred at 60 ° C. for 2 hours. The reaction solution was allowed to cool to room temperature and reprecipitated with 1.8 L of methanol to obtain a white precipitate. The obtained white precipitate was filtered off and dried at 190 ° C. to obtain a polymer HP-2 which is a linear homopolymer.

<Comparative Synthesis Example 3: Synthesis of Comparative Polymer HP-3>
In a 300 mL Erlenmeyer flask, 133.5 g of methyl methacrylate, 0.1 g of dimethyl 2,2′-azobisisobutyrate and 75.0 g of methyl ethyl ketone are weighed and mixed to dissolve the monomer composition. Prepared.
Next, 75.0 g of methyl ethyl ketone was charged into a 1 L three-necked flask equipped with a thermometer, a stirring blade and a reflux ring, and stirred at 85 ° C. under a nitrogen stream. The monomer composition was dropped into the methyl ethyl ketone at a rate of 1.1 mL / min. A chemical pump was used for dripping. The reaction solution after completion of the dropwise addition was further reacted at 85 ° C. for 6 hours. After completion of the reaction, the reaction solution was allowed to cool to room temperature, diluted with 500 mL of methyl ethyl ketone, and reprecipitated with 5 L of methanol to obtain a white precipitate. After filtering off the obtained white precipitate, redispersion washing with 2 L of methanol was repeated three times and dried at 60 ° C. overnight to obtain a polymer HP-3 which is a linear homopolymer.

The polymers obtained in the above synthesis examples and comparative synthesis examples are summarized in Table 1 below. The mass% of the partial structure of the polyamide chain and the partial structure other than the polyamide chain (other partial structure) shown in Table 1 below is the content of each partial structure in the polymer, and was calculated from NMR data.
Moreover, the weight average molecular weight (Mw) employ | adopted the weight average molecular weight measured by gel permeation chromatography (Gel Permeation Chromatography; GPC) in polystyrene conversion. Specific measurement conditions are shown below.
GPC device: GPC device manufactured by Tosoh Corporation (HLC-8320GPC, Ecosec)
Column: TSK gel SuperHZM-H, TSK gel SuperHZ4000, TSK gel SuperHZ2000 combined use (made by Tosoh, 4.6 mm ID (inner diameter) x 15.0 cm)
Eluent: N-methylpyrrolidone (NMP)
Column temperature: 40 ° C
Flow rate: 1.0 mL / min
The partial structures in Table 1 correspond to the exemplary structures described above.

[Test Example 1: Polymer solubility test]
In a vial, 0.2 g of the polymer synthesized above and a predetermined amount of methylene chloride / methanol (= 80/20 (w / w)) mixed solvent (polymer concentration is 10% by mass, 5% by mass, 1% by mass, And adjusted with a rotor (manufactured by ASONE, MIX ROTOR VMR-SR), and stirred at room temperature for 2 hours. After completion of stirring, the dissolved state was visually observed and evaluated according to the following evaluation criteria.
(Solubility evaluation criteria)
A: Completely dissolved at 10% by mass B: Completely dissolved at 5% by mass, but not completely dissolved at 10% by mass C: Completely dissolved at 1% by mass, but not completely dissolved at 5% by mass D: 1% by mass The results are shown in the table below.

  As shown in Table 2 above, it can be seen that the polyamide composed only of the structural unit of the general formula (1) defined in the present invention is inferior in solubility and difficult to apply to solution casting. In contrast, the polymers P-1 to P-10 which are the block polymer and graft polymer defined in the present invention have a polymer chain other than the polyamide chain in addition to the polyamide chain having the structural unit of the general formula (1). It is. Therefore, the solubility can be increased with respect to the solvent used for solution casting.

[Production Example 1: Production of laminates S-1 to S-10 and HS-1 and HS-2]
<Production of cellulose ester layer>
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 (manufactured by Tinuvin 328 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 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 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 thickness of the obtained cellulose ester layer (cellulose ester film) was 55 μm.

<Preparation of laminated body S-1>
The polymer P-1 was mixed with methyl ethyl ketone so as to have a solid content of 15% by mass, charged into a separable flask made of glass 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, a composition for forming a polyamide chain-containing polymer layer was obtained. Next, the above-mentioned composition for forming a polyamide chain-containing polymer layer was applied onto the cellulose ester layer prepared above using a gravure coater. Next, the applied composition for forming a polyamide chain-containing polymer layer 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 thickness of 60 μm.

<Preparation of laminated bodies S-2 to S-10 and comparative laminated bodies HS-1 and HS-2>
In preparation of the said laminated body S-1, except having changed the polymer P-1 used for the composition for polyamide chain containing polymer layer forming as shown in following Table 3, it is the same as that of preparation of the said laminated body S-1. Laminated bodies S-2 to S-10 and comparative laminated bodies HS-1 and HS-2 were produced.
The thicknesses of the obtained laminates were all 60 μm. In addition, HP-2 had low solubility, and it was not possible to form a laminate using HP-2.

[Test Example 2: Interlayer adhesion test of laminate]
The adhesion between the polyamide chain-containing polymer layer and the cellulose ester layer was measured by a cross cut test (cross cut method) according to JIS K 5400. The specific procedure is shown below.
In each of the laminates produced above, eleven notches were cut into the surface on the polyamide chain-containing polymer layer side using a cutter knife and a cutter guide at intervals of 1 mm to produce 100 grids. A cellophane tape (registered trademark) was strongly pressed onto the grid, and the end of the tape was peeled off at an angle of 45 ° with respect to the surface. The cellophane tape (registered trademark) was applied and peeled off five times continuously. A new cellophane tape (registered trademark) was used each time.
Thereafter, the state of the grids (the ratio of the grids that were peeled out of the 100 grids (lattices)) was observed. The observation results were evaluated by applying the following evaluation criteria.
<Adhesion evaluation criteria>
A: When the peeling of the grid is less than 5% B: When the peeling of the grid is 5% or more and less than 15% C: When the peeling of the grid is 15% or more and less than 30% D: When the peeling of the lattice is 30% or more, the results are shown in Table 3 below.

[Test Example 3: Evaluation of moisture permeability of laminate (moisture permeability at 40 ° C. and 90% relative humidity)]
For the water vapor transmission rate, the measurement of vapor permeation (mass method, thermometer method, vapor pressure method, adsorption amount method) is applied. ,evaluated. The specific procedure is shown below.
According to the method of JIS Z-0208, each laminated body produced above was cut, and this cut laminated body was attached to a moisture permeable cup to obtain a test sample. This test sample was conditioned for 24 hours under conditions of a temperature of 40 ° C. and a relative humidity of 90%.
The weight of the test sample before and after humidity control is weighed, the weight of the test sample before humidity control is a, and the weight of the sample after humidity control is b. Calculated.
Δm = | a−b |
Subsequently, the above Δm was converted to a value per 1 m ² of the sample area and used as moisture permeability (g / m ² / day). The moisture permeability of each obtained laminate was evaluated according to the following evaluation criteria.
<Moisture permeability evaluation criteria>
A: The moisture permeability is less than 500 g / m ² / day.
B: The moisture permeability is 500 g / m ² / day or more and less than 1000 g / m ² / day.
C: The water vapor transmission rate is 1000 g / m ² / day or more and less than 1200 g / m ² / day.
D: Moisture permeability is 1200 g / m ² / day or more.
The results are shown in Table 3 below.

As shown in Table 3 above, the comparative laminate HS-2 in which the layer laminated on the cellulose ester film is composed only of an acrylic resin has a low affinity with the cellulose ester layer and results in poor interlayer adhesion. It became. Moreover, this HS-2 was also inferior in moisture permeability.
In addition, the laminate HS-1 using a block polymer having a polyamide chain having a structure different from the polyamide chain defined in the present invention has high affinity with cellulose ester and excellent interlayer adhesion, but has high moisture permeability. The result decreased.
On the other hand, the laminates of the present invention were all excellent in interlayer adhesion, and the water vapor transmission was remarkably suppressed.

[Production Example 2: Preparation of polarizing plates PL-1 to PL-10 and comparative polarizing plates HPL-1 and HPL-2]
As described below, polarizing plates PL-1 to PL-10 and comparative polarizing plates HPL-1 and HPL-2 were produced.

<Production of polarizer>
According to Example 1 of Unexamined-Japanese-Patent No. 2001-141926, iodine was made to adsorb | suck to the stretched polyvinyl alcohol film, and the 27-micrometer-thick polarizer was produced.

<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.

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Composition of active energy ray-curable adhesive composition ――――――――――――――――――――――――――――――――――
Radical polysynthetic compound: Aronix M-220 manufactured by Toa Gosei Co., Ltd.
20.0 parts by weight N-hydroxylacrylamide 40.0 parts by weight manufactured by Kojin Co., Ltd. 40.0 parts by weight acroylmorpholine manufactured by Kojin Co., Ltd. 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 plate>
Corona treatment was performed on the polyamide chain-containing polymer layer side of each laminate 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.
Subsequently, the surface of each laminate applied with the active energy ray-curable adhesive composition and the surface of the cycloolefin-based film applied with the active energy ray-curable adhesive composition of the polarizer produced above were used. A polarizing plate precursor was prepared by bonding to both sides. 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 in each laminated body might become parallel. Moreover, it arrange | positioned so that the longitudinal direction of the roll of a polarizer and the longitudinal direction of the said cycloolefin type film might become parallel.

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. Then, it heated-air-dried at 70 degreeC for 3 minute (s), and each polarizing plate was obtained.
(Active energy rays)
As active energy rays, ultraviolet rays (gallium filled metal halide lamp), irradiation device: 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. In addition, the illumination intensity of the ultraviolet-ray was measured using the Sola-Check system by Solatell.

[Test Example 4: Evaluation of polarizer durability of polarizing plate]
For the polarizer durability of the polarizing plate, the degree of polarization was measured as follows in the form in which the polarizing plate was attached to glass via an adhesive.
Two samples (about 5 cm × 5 cm) in which a polarizing plate was attached on a glass plate so that the side of the laminated body was on the air interface side (side away from the glass plate) were prepared. About these samples, the glass plate side was set toward the light source, and the degree of polarization was measured. Each of the two samples was measured and the arithmetic average value was taken as the polarization degree of the polarizing plate.
The degree of polarization was calculated by the following formula.

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

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

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

(Polarizer durability evaluation criteria)
A: Polarization degree change amount is less than 0.05% B: Polarization degree change amount is 0.05% or more and less than 0.5% C: Polarization degree change amount is 0.5% or more and less than 1.0% D: Polarization degree The amount of change is 1.0% or more. The results are shown in Table 4 below.

As shown in Table 4 above, when a laminate having no polyamide chain-containing polymer layer as defined in the present invention was used as a protective film for a polarizer, it was polarized when exposed to high temperature and high humidity conditions for a long time. The result was that the child deteriorated significantly.
On the other hand, it was found that when the laminate of the present invention was used as a protective film for a polarizer, deterioration of the polarizer could be effectively suppressed even when exposed to high temperature and high humidity conditions for a long time.

  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 the priority based on Japanese Patent Application No. 2016-149500 for which it applied for a patent in Japan on July 29, 2016, and this is referred to here for the contents of this description. Capture as part.

10 Laminate (laminate)
DESCRIPTION OF SYMBOLS 11 Cellulose ester layer 12 Polyamide chain-containing polymer layer 20 Liquid crystal display device 21 First (upper) polarizing plate 22 First polarizing plate absorption axis direction 23 First (on liquid crystal cell) electrode substrate 24 Liquid crystal layer 25 Second (liquid crystal cell) Lower) Electrode substrate 26 Second (lower) polarizing plate 27 Direction of second polarizing plate absorption axis

Claims (8)

A laminate having a structure in which a layer containing a cellulose ester and a block polymer containing a polyamide chain and / or a layer containing a graft polymer containing a polyamide chain are arranged adjacent to each other,
A laminate in which the polyamide chain has a structural unit represented by the following general formula (1).

Wherein, ^{X 1} and ^{X 2} represents an amide bond. L ¹ represents a single bond or a divalent group. R ^{1 to} R ³ represent an alkyl group, an alkenyl group, an aryl group, an alkoxy group, a hydroxy group, a carboxy group, or a halogen atom. n ¹ ~n ³ is an integer of 0-4. * Indicates a connecting part. The laminate according to claim 1, wherein L ¹ is represented by any of the following formulas (1-a) to (1-j).

In formula, * shows a coupling | bond part. The laminate according to claim 1 or 2, wherein the block polymer and the graft polymer have a structural unit represented by the following general formula (2).

In the formula, R ⁴ represents an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 3 to 20 carbon atoms. R ⁵ represents a hydrogen atom or an alkyl group. R ⁶ and R ⁷ represent a hydrogen atom, an alkyl group, an aryl group or an alkoxycarbonyl group. * Indicates a connecting part.   The laminate according to any one of claims 1 to 3, wherein the cellulose ester is cellulose acylate.   The optical film using the laminated body of any one of Claims 1-4.   The polarizing plate protective film using the laminated body of any one of Claims 1-4.   The polarizing plate which has the laminated body of any one of Claims 1-4, and a polarizer.   An image display device comprising the polarizing plate according to claim 7.

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