WO2020218061A1

WO2020218061A1 - Curable composition, cured product layer, optical laminate, and image display device

Info

Publication number: WO2020218061A1
Application number: PCT/JP2020/016288
Authority: WO
Inventors: 亜依小橋; 悠司淺津
Original assignee: 住友化学株式会社
Priority date: 2019-04-26
Filing date: 2020-04-13
Publication date: 2020-10-29
Also published as: TW202043300A; JP2020180238A

Abstract

This curable composition includes an aqueous resin and a silane compound. The aqueous resin includes an oxazolyl group-containing polymer. This curable composition also ideally includes an acid compound and the oxazolyl group-containing polymer ideally is an oxazolyl group-containing (meth) acrylic polymer.　This optical laminate includes an optical layer and a first cured product layer comprising a cured product of the curable composition.

Description

Curable composition, cured product layer, optical laminate, and image display device

The present invention relates to a curable composition. The present invention also relates to a cured product layer composed of a cured product of the curable composition, an optical laminate containing the cured product layer, and an image display device including the optical laminate.

In recent years, liquid crystal display devices have been developed for mobile device applications such as smartphones and tablet terminals and in-vehicle device applications such as car navigation systems. In such an application, since there is a possibility of being exposed to a harsher environment as compared with the conventional indoor TV application, it is an issue to improve the durability of the device.

Durability is also required for optical films that make up liquid crystal display devices and the like. That is, the optical film incorporated in the liquid crystal display device or the like may be placed in a high temperature or high temperature and high humidity environment, or may be placed in an environment in which high temperature and low temperature are repeated. In these environments, However, it is required that the optical characteristics do not deteriorate.

Examples of the optical film include a polarizing plate in which a protective film is attached to one side or both sides of a polarizing element using an adhesive (Patent Document 1 and the like).

JP-A-2017-82026

An object of the present invention is to provide a curable composition containing a cured product layer composed of a cured product of the curable composition and capable of providing an optical laminate having good optical durability in a high temperature and high humidity environment. There is.
Another object of the present invention is to provide an optical laminate containing a cured product layer composed of a cured product of a curable composition and having good optical durability in a high temperature and high humidity environment, and an image display device including the same. To do.

The present invention provides the curable composition, the cured product layer, the optical laminate, and the image display device shown below.
[1] Containing an aqueous resin and a silane compound,
The aqueous resin is a curable composition containing an oxazolyl group-containing polymer.
[2] The curable composition according to [1], wherein the oxazolyl group-containing polymer is an oxazolyl group-containing (meth) acrylic polymer.
[3] The curable composition according to [1] or [2], which further contains an acid compound.
[4] The curable composition according to any one of [1] to [3], wherein the silane compound has a silanol group.
[5] The silane compound further comprises a group consisting of an amino group, a carboxyl group, an epoxy group, an acetoacetyl group, a hydroxyalkyl group, a mercapto group, an oxyalkylene group, and an alkenyl group which may have a substituent. The curable composition according to [4], which has one or more functional groups of choice.
[6] The curing according to [4] or [5], wherein the silane compound further has a functional group having at least one functional group of an amino group and a carboxyl group which may have a substituent. Sex composition.
[7] The silane compound further contains a Si—O—Si bond and contains
The curable composition according to [5] or [6], which has the functional group in the structure of the silane compound.
[8] A cured product layer obtained by curing the curable composition according to any one of [1] to [7].
[9] Includes an optical layer and a first cured product layer
The first cured product layer is an optical laminate which is the cured product layer according to [8].
[10] Further, it contains a first thermoplastic resin film, and contains
The optical laminate according to [9], wherein the optical layer, the first cured product layer, and the first thermoplastic resin film are laminated in this order.
[11] Further, a second cured product layer and a second thermoplastic resin film are included.
The optical according to [9] or [10], wherein the second cured product layer and the second thermoplastic resin film are laminated in this order on the side of the optical layer opposite to the first cured product layer side. Laminated body.
[12] The optical laminate according to [11], wherein the second cured product layer is a cured product of the curable composition according to [8].
[13] An image display device including the optical laminate according to any one of [1] to [13] and an image display element.

It is possible to provide a curable composition containing a cured product layer composed of a cured product of the curable composition and capable of providing an optical laminate having good optical durability in a high temperature and high humidity environment.
It is possible to provide an optical laminate containing a cured product layer composed of a cured product of a curable composition and having good optical durability in a high temperature and high humidity environment, and an image display device including the same.

It is the schematic sectional drawing which shows an example of the optical laminated body which concerns on this invention. It is schematic cross-sectional view which shows another example of the layer structure of the optical laminate which concerns on this invention. It is schematic cross-sectional view which shows another example of the layer structure of the optical laminate which concerns on this invention. It is schematic cross-sectional view which shows another example of the layer structure of the optical laminate which concerns on this invention. It is schematic cross-sectional view which shows another example of the layer structure of the optical laminate which concerns on this invention. It is schematic cross-sectional view which shows another example of the layer structure of the optical laminate which concerns on this invention.

<Curable composition>
The curable composition according to the present invention contains an aqueous resin and a silane compound, and the aqueous resin contains an oxazolyl group-containing polymer. Hereinafter, the curable composition according to the present invention is referred to as "curable composition (S)", the above-mentioned aqueous resin is referred to as "aqueous resin (A)", and the above-mentioned oxazolyl group-containing polymer is referred to as "oxazolyl group-containing polymer (a)". , The silane compound having a silanol group may be referred to as "silane compound (B)".

The curable composition (S) can be used as a coating liquid for forming a coating film (coating layer) on the substrate. For example, a coating film can be formed by applying the curable composition (S) onto a base material and curing the coating layer. The base material is preferably an optical layer. The optical layer will be described later. In this case, the optical laminate includes an optical layer and a first cured product layer composed of a cured product of the curable composition (S).

The curable composition (S) can also be used as an adhesive composition. In one embodiment, the curable composition (S) is an adhesive composition for adhering the optical layer and the first thermoplastic resin film. In this case, the optical laminate includes an optical layer, a first cured product layer (adhesive layer) composed of a cured product of the curable composition (S), and a first thermoplastic resin film in this order.
In this optical laminate, the curable composition (S) is coated on at least one of the bonding surfaces of the optical layer and the first thermoplastic resin film, and the optical layer and the first thermoplastic are passed through the coating layer. It can be produced by laminating a resin film to obtain a laminated body and then curing the coating layer.

The curable composition (S) is an aqueous composition containing the aqueous resin (A). The aqueous composition is a solution in which the compounding component is dissolved in a solvent containing water, or a dispersion (for example, an emulsion) in which the compounding component is dispersed in a solvent containing water.

The viscosity of the curable composition (S) at 25 ° C. is preferably 50 mPa · sec or less, more preferably 1 mPa · sec or more and 30 mPa · sec or less, and 2 mPa · sec or more and 20 mPa · sec or less. Is even more preferable. If the viscosity at 25 ° C. exceeds 50 mPa · sec, it becomes difficult to apply the coating uniformly, which may cause uneven coating, and may cause problems such as clogging of piping.
The viscosity of the curable composition (S) at 25 ° C. can be measured by an E-type viscometer.

[1] Water-based resin (A)
The water-based resin (A) contains at least one of a water-soluble polymer soluble in an aqueous solvent and an water-dispersible polymer dispersible in an aqueous solvent. The water-soluble polymer is not particularly limited as long as it is a polymer that can be dissolved in an aqueous solvent. The water-dispersible polymer is not particularly limited as long as it is a polymer that can be dispersed in an aqueous solvent.

In the present specification, the aqueous solvent means water or a solvent containing water as a main component, and the term "water as a main component" means that 50% by mass or more of the total mass of the components constituting the solvent is water. The solvent other than water among the aqueous solvents is not particularly limited as long as it is a solvent that does not easily layer-separate in the coexistence with water, but is preferably a solvent that dissolves in water, for example, methanol, ethanol, or isopropyl alcohol. , Alcohols such as n-propyl alcohol; ketones such as acetone and methyl ethyl ketone; glycols such as ethylene glycol and diethylene glycol; glycol ethers such as N-methylpyrrolidone (NMP), tetrahydrofuran and butyl cellosolve and the like.

The aqueous resin (A) contains at least the oxazolyl group-containing polymer (a).
The aqueous resin (A) is one or 2 selected from a water-soluble polymer soluble in an aqueous solvent other than the oxazolyl group-containing polymer (a) and an aqueous-dispersible polymer dispersible in an aqueous solvent. It may contain more than a seed.

The content of the aqueous resin (A) in the curable composition (S) is preferably 50% by mass or more and 95% by mass or less, more preferably, when the solid content concentration of the curable composition (S) is 100% by mass. Is 55% by mass or more and 90% by mass or less, more preferably 60% by mass or more and 85% by mass or less. Keeping the content of the aqueous resin (A) within the above range improves the optical durability of the optical laminate in a high temperature and high humidity environment, and between the optical layer and the first cured product layer in the optical laminate. It is preferable from the viewpoint of adhesion and adhesion between the first cured product layer and the first thermoplastic resin film.
The solid content concentration refers to the total concentration of components other than the solvent contained in the curable composition (S).

[1-1] Oxazolyl group-containing polymer (a)
The oxazolyl group-containing polymer (a) is a water-soluble polymer that can be dissolved in an aqueous solvent and an aqueous-dispersible polymer that can be dispersed in an aqueous solvent. From the viewpoint of the optical properties of the first cured product layer, the oxazolyl group-containing polymer (a) is preferably a water-soluble polymer.

The oxazolyl group-containing polymer (a) is a polymer having an oxazolyl group in the molecule, and is preferably a polymer having an oxazolyl group in the side chain.
The skeleton structure of the oxazolyl group-containing polymer (a) is not particularly limited, and may consist of, for example, one or more skeletons selected from (meth) acrylic skeleton, styrene skeleton, olefin skeleton, ester skeleton, carbonate skeleton and the like. it can.
As used herein, the term "(meth) acrylic" refers to at least one selected from the group consisting of acrylic and methacrylic. The same applies to the notations such as "(meth) acryloyl" and "(meth) acrylate".

The oxazolyl group-containing polymer (a) can have an oxazolyl group in the side chain of the skeletal structure.
The oxazolyl group-containing polymer (a) may contain a structural unit having an oxazolyl group in the side chain (a structural unit derived from an oxazolyl group-containing monomer) and a structural unit having no oxazolyl group.
A preferable example of the oxazolyl group-containing polymer (a) is a structural unit (derived from an oxazolyl group-containing monomer) having a skeleton structure composed of a (meth) acrylic skeleton as the main component of the structural unit and having an oxazolyl group in the side chain as a copolymerization component. It is an oxazolyl group-containing (meth) acrylic polymer into which the constituent unit of the above is introduced.
The oxazolyl group-containing polymer (a) may be a copolymer of an oxazolyl group-containing monomer or a polymer containing an oxazolyl group by modifying the side chain functional group of the polymer.

Examples of the oxazolyl group include a 2-oxazolyl group, a 3-oxazolyl group, a 4-oxazolyl group and the like. The oxazolyl group is preferably a 2-oxazolyl group or the like.
Examples of the oxazoline group-containing monomer include 2-isopropenyl-2-oxazoline and vinyl-2-oxazoline.

The weight average molecular weight of the oxazolyl group-containing polymer (a) is preferably 5,000 or more, and more preferably 10,000 or more. The fact that the weight average molecular weight is in the above range means that the optical durability of the optical laminate in a high temperature and high humidity environment is improved, the adhesion between the optical layer and the first cured product layer in the optical laminate, and the first cured product. It can be advantageous from the viewpoint of adhesion between the layer and the first thermoplastic resin film.
The weight average molecular weight of the oxazolyl group-containing polymer (a) is usually 1,000,000 or less.
The weight average molecular weight of the oxazolyl group-containing polymer (a) can be measured as a standard polystyrene-equivalent value by gel permeation chromatography (GPC).

The amount of oxazolyl groups (the number of moles of oxazolyl groups per 1 g of solid content of the oxazolyl group-containing polymer (a)) of the oxazolyl group-containing polymer (a) is preferably 0.4 mmol / g · solid or more. If the amount of oxazolyl groups is smaller than the above range, the optical durability of the optical laminate in a high temperature and high humidity environment may be disadvantageous. From this point of view, the amount of oxazolyl groups in the oxazolyl group-containing polymer is more preferably 3 mmol / g · solid or more, still more preferably 5 mmol / g · solid or more and 9 mmol / g · solid or less.
The upper limit of the amount of oxazolyl group is not particularly limited, but is usually 50 mmol / g · solid or less.

A commercially available product may be used as the oxazolyl group-containing polymer (a). Specifically, oxazolyl group-containing acrylic polymers such as Epocross WS-300, Epocross WS-500, and Epocross WS-700 (all trade names) manufactured by Nippon Shokubai Co., Ltd .; Epocross K-1000 series and Epocross manufactured by Nippon Shokubai Co., Ltd. Examples thereof include oxazolyl group-containing acrylic / styrene polymers such as K-2000 series and Epocross RPS series (both are trade names).
The oxazolyl group-containing polymer (a) can be used in combination of two or more.
Optical durability and optical characteristics of the optical laminate in a high temperature and high humidity environment, adhesion between the optical layer and the first cured product layer in the optical laminate, and the first cured product layer and the first thermoplastic resin film. From the viewpoint of the adhesion between the layers and the water resistance of the first cured product layer, the oxazolyl group-containing polymer (a) is an oxazolyl group-containing acrylic polymer such as Epocross WS-300, Epocross WS-500, and Epocross WS-700. It is preferable to have.

The content of the oxazolyl group-containing polymer (a) is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably, when the total amount of the aqueous resin (A) is 100% by mass. Is 70% by mass or more, may be 100% by mass, is usually 100% by mass or less, may be 99% by mass or less, or may be 95% by mass or less. Keeping the content of the oxazolyl group-containing polymer (a) within the above range improves the optical durability of the optical laminate in a high temperature and high humidity environment, and the optical layer and the first cured product layer in the optical laminate. It is preferable from the viewpoint of the adhesion between the first cured product layer and the first thermoplastic resin film.

[1-2] Other water-based resins The water-based resin (A) is a water-soluble polymer soluble in an aqueous solvent other than the oxazolyl group-containing polymer (a) and a water-dispersible weight dispersible in an aqueous solvent. It may contain a coalescence (hereinafter, these may be collectively referred to as "other aqueous polymers").
Examples of other aqueous polymers include (meth) acrylic polymers; polyvinyl alcohol-based polymers; polyvinyl acetal-based polymers; ethylene-vinyl alcohol copolymers; polyvinylpyrrolidone-based polymers; polyamide-amine-based polymers; Epoxy-based polymer; Melamine-based polymer; Uria-based polymer; Polyamide-based polymer; Polyester-based polymer; Polyurethane-based polymer; Cellulous polymer such as methyl cellulose, hydroethyl cellulose, carboxymethyl cellulose; Sodium alginate, starch, etc. Examples include polymers.

The content of the other aqueous polymer is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass, when the total amount of the aqueous resin (A) is 100% by mass. % Or less, 20% by mass or less, or 10% by mass or less.

[2] Silane compound (B)
The silane compound (B) is preferably a compound in which an arbitrary functional group is bonded to a silicon atom. Examples of such a functional group include a hydrolyzable group such as an alkoxy group, an organic group having a reactive functional group such as a vinyl group, an amino group, an epoxy group, a haloalkyl group, a (meth) acroyl group and a mercapto group. Can be mentioned.
The silane compound (B) can be used alone or in combination of two or more.
By adding the silane compound (B) to the curable composition (S), the optical durability of the optical laminate in a high temperature and high humidity environment can be improved.

Examples of the silane compound (B) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, and N- (2). -Aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ) Ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3 -Glysidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropylethoxydimethylsilane and the like can be mentioned.

The silane compound (B) may be of the silicone oligomer type. When the silicone oligomer is shown in the form of a (monomer) oligomer, for example, the following can be mentioned.

3-Mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer,
3-Mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer,
3-Mercaptopropyltriethoxysilane-tetramethoxysilane copolymer,
A mercaptopropyl group-containing copolymer such as 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer;
Mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer,
Mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer,
Mercaptomethyltriethoxysilane-tetramethoxysilane copolymer,
Mercaptomethyl group-containing copolymers such as mercaptomethyltriethoxysilane-tetraethoxysilane copolymer;
3-Glydoxypropyltrimethoxysilane-tetramethoxysilane copolymer,
3-Glydoxypropyltrimethoxysilane-tetraethoxysilane copolymer,
3-Glydoxypropyltriethoxysilane-tetramethoxysilane copolymer,
3-Glydoxypropyltriethoxysilane-tetraethoxysilane copolymer,
3-Glydoxypropylmethyldimethoxysilane-tetramethoxysilane copolymer,
3-Glydoxypropylmethyldimethoxysilane-tetraethoxysilane copolymer,
3-Glydoxypropylmethyldiethoxysilane-tetramethoxysilane copolymer,
3-Glydoxypropyl group-containing copolymers such as 3-glycidoxypropylmethyldiethoxysilane-tetraethoxysilane copolymer;
3-Methoxyloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer,
3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer,
3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer,
3-Methacloyloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer,
3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer,
3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer,
3-Methacloyloxypropyl methyldiethoxysilane-tetraethoxysilane copolymer or other copolymer containing a methacryloyloxypropyl group;
3-Acryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer,
3-Acryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer,
3-Acryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer,
3-Acryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer,
3-Acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer,
3-Acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer,
3-Acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer,
Acryloyloxypropyl group-containing copolymers such as 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer;
Vinyl Trimethoxysilane-Tetramethoxysilane Copolymer,
Vinyl Trimethoxysilane-Tetraethoxysilane Copolymer,
Vinyltriethoxysilane-tetramethoxysilane copolymer,
Vinyltriethoxysilane-tetraethoxysilane copolymer,
Vinylmethyldimethoxysilane-tetramethoxysilane copolymer,
Vinylmethyldimethoxysilane-tetraethoxysilane copolymer,
Vinyl methyldiethoxysilane-tetramethoxysilane copolymer,
Vinyl group-containing copolymers such as vinylmethyldiethoxysilane-tetraethoxysilane copolymer;
3-Aminopropyltrimethoxysilane-tetramethoxysilane copolymer,
3-Aminopropyltrimethoxysilane-tetraethoxysilane copolymer,
3-Aminopropyltriethoxysilane-tetramethoxysilane copolymer,
3-Aminopropyltriethoxysilane-tetraethoxysilane copolymer,
3-Aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer,
3-Aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer,
3-Aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer,
Amino group-containing copolymers such as 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer.

The silane compound (B) is preferably a compound having a silanol group (-SiOH).
The silane compound (B) having a silanol group is not particularly limited as long as it has a silanol group. It may be a monomer having a silanol group. Further, even if a silanol group forms a dimer or a trimer by a condensation reaction or the like or a three-dimensional network structure is formed, if the formed body has a silanol group, a silanol group can be used. It can be included in the silane compound (B) having.

The silane compound (B) is composed of an amino group, a carboxyl group, an epoxy group, an acetoacetyl group, a hydroxyalkyl group, a mercapto group, an oxyalkylene group, and an alkenyl group which may have a substituent in addition to the silanol group. It is preferable to have one or more functional groups selected from the group. Of these, the silane compound (B) more preferably has a functional group of at least one of an amino group and a carboxyl group which may have a substituent in addition to the silanol group, and has a carboxyl group. Is even more preferable.
Amino groups that may have a substituent include an amino group that does not have a substituent (-NH ₂ ), an alkylamino group in which one or two hydrogen atoms are substituted with an alkyl group, one or one. A (hydroxyalkyl) amino group in which two hydrogen atoms are substituted with a hydroxyalkyl group (for example, -N (CH ₂ HC (OH) CH ₂ OH ₂ ) ₂ ), an aminoalkyl amino group (-NHC ₂ H ₄ NH _2). ) Etc. can be mentioned.
Specific examples of the functional groups include -NH ₂ , -NHC ₂ H ₄ NH ₂ , -COOH, -CH (OH) CH ₂ OH, and -N (CH ₂ HC (OH) CH ₂ OH ₂ ) _2. , -CHCH ₂ , -SH and the like.

When the silane compound (B) has two or more of the above functional groups, the functional groups may be the same or different from each other.
The above-mentioned functional group which the silane compound (B) having a silanol group may have can react with the oxazolyl group of the oxazolyl group-containing polymer (a). Since the silane compound (B) has the above functional groups, the silane compound (B) and the oxazolyl group-containing polymer (a) can react with each other. Therefore, the optical durability of the optical laminate in a high temperature and high humidity environment It is easy to improve the properties, the adhesion between the optical layer and the first cured product layer in the optical laminate, and the adhesion between the first cured product layer and the first thermoplastic resin film.

The silane compound (B) preferably contains a Si—O—Si bond in addition to the silanol group and the above-mentioned functional group. The silanol group and the above-mentioned functional group may be present anywhere in the structure of the silane compound (B) containing a Si—O—Si bond, but the silane compound (B) containing a Si—O—Si bond). It is preferable to have the above-mentioned functional group at the end of.

The content of the silane compound (B) is usually 0.01 part by mass or more with respect to 100 parts by mass of the aqueous resin (A) from the viewpoint of enhancing the optical durability of the optical laminate in a high temperature and high humidity environment. It is preferably 0.1 part by mass or more, more preferably 1 part by mass or more, and usually 60 parts by mass or less, preferably 45 parts by mass or less, and 30 parts by mass or less. Is more preferable.
By setting the content of the silane compound (B) in the curable composition (S) within the above range, the optical durability of the optical laminate in a high temperature and high humidity environment is improved, and the optical layer in the optical laminate is used. Good adhesion can be obtained between the first cured product layer and between the first cured product layer and the first thermoplastic resin film.
If the content of the silane compound (B) is excessively small, it is difficult to obtain the optical durability of the optical laminate in a high temperature and high humidity environment. Further, if the content of the silane compound (B) is excessively large, the optical durability of the optical laminate in a high temperature and high humidity environment tends to decrease.

[3] Acid compound (C)
The acid compound (C) can promote the reaction between the oxazolyl group of the oxazolyl group-containing polymer (a) and the functional group of the silane compound (B), particularly the above-mentioned reactive functional group. The promotion referred to here includes the case of initiating the reaction.

The silane compound (B) consists of an amino group, a carboxyl group, an epoxy group, an acetoacetyl group, a hydroxyalkyl group, a mercapto group, an oxyalkylene group, and an alkenyl group which may have a substituent in addition to the silanol group. When having one or more functional groups selected from the group, the acid compound (C) can accelerate the reaction between this functional group and the oxazolyl group of the oxazolyl group-containing polymer (a). The acid compound (C) may be a compound that functions as a catalyst for the reaction between the oxazolyl group of the oxazolyl group-containing polymer (a) and the above-mentioned functional group of the silane compound (B).

Examples of the acid compound (C) include inorganic acids such as sulfuric acid, hydrogen chloride, nitrate, phosphoric acid, phosphite, and boric acid; p-toluenesulfonic acid, dodecylbenzenesulfonic acid, naphthalenesulfonic acid, methanesulfonic acid, and benzenesulfon. Examples thereof include organic acids such as acids, phenylphosphoric acids, sulfanic acids, phenylphosphonic acids, acetic acids and propionic acids.
Among them, the acid compound (C) has the optical durability of the optical laminate in a high temperature and high humidity environment, the adhesion between the optical layer and the first cured product layer in the optical laminate, and the first cured product layer and the first cured product layer. From the viewpoint of enhancing the adhesion with the thermoplastic resin film, a relatively strong acid is preferable, and examples of such an acid compound include sulfuric acid, hydrogen chloride (hydrochloric acid), nitric acid, p-toluenesulfonic acid and the like. Be done.
When the above-mentioned strong acid is used as the acid compound (C), the adhesion between the optical layer and the first cured product layer in the optical laminate and the adhesion between the first cured product layer and the first thermoplastic resin film are particularly high. There is a tendency to improve the adhesion between them.

The curable composition (S) may contain one kind of acid compound (C) or may contain two or more kinds of acid compounds (C).
The acid compound (C) may be blended in the curable composition (S) as a solution (for example, an aqueous solution) containing the acid compound (C).

The content of the acid compound (C) is preferably 5 parts by mass or more and 80 parts by mass or less, more preferably 80 parts by mass, based on 100 parts by mass of the aqueous resin (A) (preferably the oxazolyl group-containing polymer (a)). It is 10 parts by mass or more and 70 parts by mass or less, and more preferably 15 parts by mass or more and 60 parts by mass or less.
When the content of the acid compound (C) is excessively small, the adhesion between the optical layer and the first cured product layer and between the first cured product layer and the first thermoplastic resin film in the optical laminate It is difficult to obtain at least one of. Further, when the content of the acid compound (C) is excessively large, it is between the optical layer and the first cured product layer in the optical laminate and between the first cured product layer and the first thermoplastic resin film. At least one of the adhesions tends to decrease.

[4] Other components The curable composition (S) can contain other components other than the aqueous resin (A), the silane compound (B), and the acid compound (C).
Other components include curable components such as polyvalent aldehydes such as glioxal and glioxal derivatives, melamine compounds, aziridine compounds, water-soluble epoxy resins, zirconium compounds, zinc compounds, titanium compounds, and metal compounds such as aluminum compounds, and cross-linking. Agents: Modified polyvinyl alcohol-based polymers other than carboxyl group-modified polyvinyl alcohol-based polymers; Additives such as coupling agents, tackifiers, antioxidants, ultraviolet absorbers, heat stabilizers, and hydrolysis inhibitors. ..
The curable composition (S) may contain one or more other components.

The curable composition (S) preferably contains an aqueous solvent for dissolving or dispersing the aqueous resin (A). As the aqueous solvent, those exemplified above can be used. As the aqueous solvent, 80% by mass or more of the total mass of the aqueous solvent is preferably water, more preferably 90% by mass or more is water, further preferably 95% by mass or more is water, and water. It may contain only.
The solid content concentration of the curable composition (S) is usually 0.5% by mass or more and 20% by mass or less, preferably 1% by mass or more and 15% by mass or less.

<Optical laminate>
The optical laminate according to the present invention includes an optical layer and a first cured product layer (a cured product layer composed of a cured product of the curable composition (S)) laminated on at least one surface thereof.
According to the present invention, since the cured product layer contained in the optical laminate is composed of the cured product of the curable composition (S), the optical laminate has good optical durability in a high temperature and high humidity environment. Can be.

[1] Configuration of Optical Laminates FIGS. 1 to 5 show examples of layer configurations of the optical laminates.
The optical laminate shown in FIG. 1 includes an optical layer 30 and a first cured product layer 15 laminated on one surface of the optical layer 30. The first cured product layer 15 can function as an overcoat layer that coats and protects the surface of the optical layer 30, an optical functional layer that additionally imparts an optical function to the optical layer 30, and the like.
It is preferable that the optical layer 30 and the first cured product layer 15 are in direct contact with each other.

The optical laminate shown in FIG. 2 includes an optical layer 30 and a first thermoplastic resin film 10 laminated and bonded to one surface thereof via a first cured product layer 15. The first cured product layer 15 can function as an adhesive layer for adhering the optical layer 30 and the first thermoplastic resin film 10.
It is preferable that the first cured product layer 15 and the first thermoplastic resin film 10 are in direct contact with each other.
It is preferable that the optical layer 30 and the first cured product layer 15 are in direct contact with each other.

The optical laminate shown in FIG. 3 includes an optical layer 30, a first thermoplastic resin film 10 laminated and bonded to one surface of the optical layer 30 via a first cured product layer 15, and the other surface of the optical layer 30. Includes a second thermoplastic resin film 20 that is laminated and bonded via a second cured product layer 25. That is, the optical laminate according to the present invention includes the second thermoplastic resin film 20, the second cured product layer 25, the optical layer 30, the first cured product layer 15, and the first thermoplastic resin film 10 in this order. It may be. The first cured product layer 15 and the second cured product layer 25 each adhere an adhesive layer for adhering the optical layer 30 and the first thermoplastic resin film 10, and the optical layer 30 and the second thermoplastic resin film 20. It can function as an adhesive layer.
It is preferable that the second cured product layer 25 and the second thermoplastic resin film 20 are in direct contact with each other.
It is preferable that the optical layer 30 and the second cured product layer 25 are in direct contact with each other.

The optical laminate shown in FIG. 4 is laminated and laminated on the optical layer 30, the first cured product layer 15 laminated on one surface thereof, and the other surface of the optical layer 30 via the second cured product layer 25. Includes a second thermoplastic resin film 20 to be combined. The first cured product layer 15 can function as an overcoat layer that coats and protects the surface of the optical layer 30, an optical functional layer that additionally imparts an optical function to the optical layer 30, and the like. The second cured product layer 25 can function as an adhesive layer for adhering the optical layer 30 and the second thermoplastic resin film 20.
It is preferable that the optical layer 30 and the first cured product layer 15 are in direct contact with each other.
It is preferable that the second cured product layer 25 and the second thermoplastic resin film 20 are in direct contact with each other.
It is preferable that the optical layer 30 and the second cured product layer 25 are in direct contact with each other.

The optical laminate shown in FIG. 5 includes an optical layer 30, a first cured product layer 15 laminated on one surface of the optical layer 30, and a second cured product layer 25 laminated on the other surface of the optical layer 30. Including. The first cured product layer 15 and the second cured product layer 25 function as an overcoat layer that coats and protects the surface of the optical layer 30, an optical functional layer that additionally imparts an optical function to the optical layer 30, and the like. Can be done.
It is preferable that the optical layer 30 and the first cured product layer 15 are in direct contact with each other.
It is preferable that the optical layer 30 and the second cured product layer 25 are in direct contact with each other.

The optical layer 30 may be various optical films (films having optical characteristics) that can be incorporated into an image display device such as a liquid crystal display device. Examples of the optical layer 30 include a polarizer, a retardation film, a brightness improving film, an antiglare film, an antireflection film, a diffusion film, a light collecting film and the like.

The optical laminate can include layers (or films) other than the above. Examples of the other layer include an adhesive laminated on the outer surface of the first thermoplastic resin film 10, the second thermoplastic resin film 20, the first cured product layer 15, the second cured product layer 25, and / or the optical layer 30. Agent layer; Separate film laminated on the outer surface of the pressure-sensitive adhesive layer (also referred to as "release film"); 1st thermoplastic resin film 10, 2nd thermoplastic resin film 20, 1st cured product layer 15, 2nd A protective film (also referred to as a "surface protective film") laminated on the outer surface of the cured product layer 25 and / or the optical layer 30; the first thermoplastic resin film 10, the second thermoplastic resin film 20, and the first cured product layer. 15. Examples thereof include an optically functional film (or layer) laminated on the outer surface of the second cured product layer 25 and / or the optical layer 30 via an adhesive layer or an adhesive layer.

[2] Polarized light The polarized light is a layer or film having a function of selectively transmitting linearly polarized light in a certain direction from natural light.
Examples of the polarizer include a film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol-based resin film. Examples of the dichroic dye include iodine and a dichroic organic dye.
Further, the polarizing element may be a coating type polarizing film in which a dichroic dye in a Riotrovic liquid crystal state is coated on a base film and oriented and immobilized.
The above-mentioned polarizer is called an absorption type polarizer because it selectively transmits linearly polarized light in one direction from natural light and absorbs linearly polarized light in the other direction.

The polarizer is not limited to the absorption type polarizer, but is a reflection type polarizer that selectively transmits linearly polarized light in one direction from natural light and reflects the linearly polarized light in the other direction, or a linearly polarized light in the other direction. A scattering type polarizer may be used, but an absorption type polarizer is preferable from the viewpoint of excellent visibility. Of these, a polyvinyl alcohol-based polarizing film composed of a polyvinyl alcohol-based resin film is more preferable, and a polyvinyl alcohol-based polarizing film in which a bicolor dye such as iodine or a bicolor dye is adsorbed and oriented on the polyvinyl alcohol-based resin film is preferable. More preferably, a polyvinyl alcohol-based polarizing film in which iodine is adsorbed and oriented on the polyvinyl alcohol-based resin film is particularly preferable.

As the polyvinyl alcohol-based resin, a saponified polyvinyl acetate-based resin can be used. Examples of the polyvinyl acetate-based resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and a copolymer of vinyl acetate and another monomer copolymerizable with the vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth) acrylamides having an ammonium group.

The degree of saponification of the polyvinyl alcohol-based resin is usually 85 mol% or more and 100 mol% or less, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes can be used. The average degree of polymerization of the polyvinyl alcohol-based resin is usually 1000 or more and 10000 or less, preferably 1500 or more and 5000 or less.
The average degree of polymerization of the polyvinyl alcohol-based resin can be determined in accordance with JIS K 6726: 1994.

A film formed of such a polyvinyl alcohol-based resin is used as a raw film for a polarizing film composed of a polyvinyl alcohol-based resin film. The method for forming a film of the polyvinyl alcohol-based resin is not particularly limited, and a known method is adopted. The thickness of the polyvinyl alcohol-based raw film is, for example, 150 μm or less, preferably 100 μm or less (for example, 50 μm or less), and 5 μm or more.

A polarizing film composed of a polyvinyl alcohol-based resin film can be produced by a known method. Specifically, the step of uniaxially stretching the polyvinyl alcohol-based resin film; the step of adsorbing the dichroic dye by dyeing the polyvinyl alcohol-based resin film with the dichroic dye; the polyvinyl alcohol on which the dichroic dye is adsorbed. It can be produced by a method including a step of treating (cross-linking) the based resin film with an aqueous boric acid solution; and a step of washing with water after treatment with the aqueous boric acid solution.

The thickness of the polarizer can be 40 μm or less, preferably 30 μm or less (for example, 20 μm or less, further 15 μm or less, and further 10 μm or less or 8 μm or less). According to the methods described in JP-A-2000-338329 and JP-A-2012-159778, a thin-film polarizer can be more easily produced, and the thickness of the polarizer can be increased to, for example, 20 μm or less, further 15 μm. Below, it becomes easier to make it 10 μm or less or 8 μm or less. The thickness of the polarizer is usually 2 μm or more. Reducing the thickness of the polarizer is advantageous for reducing the thickness of the optical laminate (polarizing plate) and the image display device including the optical laminate (polarizing plate). In general, the thinner the polarizer, the lower the optical durability tends to be. However, by using the curable composition of the present invention, even such a thin-film polarizing plate can have good durability. ..

[3] Phase-difference film The retardation film is a stretched film obtained by uniaxially stretching or biaxially stretching a translucent thermoplastic resin; a film in which a liquid crystal compound such as a discotic liquid crystal or a nematic liquid crystal is oriented and fixed; Examples thereof include those in which the above-mentioned liquid crystal layer is formed on a material film. Further, in the present specification, the zero retardation film is also included in the retardation film.
The base film is usually a film made of a thermoplastic resin, and an example of the thermoplastic resin is a cellulosic ester-based resin such as triacetyl cellulose.
Examples of the translucent thermoplastic resin include resins constituting the first thermoplastic resin film 10 described later.

The zero retardation film refers to a film in which both the in-plane retardation value Re and the thickness direction retardation value Rth are -15 to 15 nm. This retardation film is suitably used for a liquid crystal display device in IPS mode. The in-plane retardation value Re and the thickness direction retardation value Rth are preferably −10 to 10 nm, and more preferably both −5 to 5 nm. The in-plane retardation value Re and the thickness direction retardation value Rth referred to here are values at a wavelength of 590 nm.

The in-plane retardation value Re and the thickness direction retardation value Rth are expressed by the following equations, respectively:
Re = (n _{x −} n _y ) × d
Rth = [(n _x + n _y ) / 2-n _z ] x d
Defined in. Wherein, n _x is a refractive index in a slow axis direction (x-axis direction) in the film plane, n _y is the fast axis direction in the film plane of the (y-axis direction orthogonal to the x-axis in a plane) The refractive index, _nz is the refractive index in the film thickness direction (the z-axis direction perpendicular to the film surface), and d is the film thickness.

As the zero retardation film, for example, a resin film made of a polyolefin resin such as a cellulose resin, a chain polyolefin resin and a cyclic polyolefin resin, a polyethylene terephthalate resin or a (meth) acrylic resin can be used. In particular, since the retardation value can be easily controlled and easily obtained, a cellulosic resin, a polyolefin resin, or a (meth) acrylic resin is preferably used.

As a film that expresses optical anisotropy by coating and orientation of a liquid crystal compound,
First form: a retardation film in which a rod-shaped liquid crystal compound is oriented horizontally with respect to a supporting substrate.
Second form: a retardation film in which the rod-shaped liquid crystal compound is oriented perpendicular to the supporting substrate,
Third form: A retardation film in which the rod-shaped liquid crystal compound changes its orientation spirally in the plane.
Fourth form: a retardation film in which a disk-shaped liquid crystal compound is inclined or oriented,
Fifth form: A biaxial retardation film in which a disk-shaped liquid crystal compound is oriented perpendicularly to a supporting substrate.

For example, as the optical layer used in the organic electroluminescence display, the first form, the second form, and the fifth form are preferably used. Alternatively, these may be laminated and used.

When the retardation film is a layer made of a polymer in the oriented state of the polymerizable liquid crystal compound (hereinafter, may be referred to as an "opticallyotropic layer"), the retardation film may have anti-wavelength dispersibility. preferable. The inverse wavelength dispersibility is an optical characteristic in which the liquid crystal alignment in-plane retardation value at a short wavelength is smaller than the liquid crystal alignment in-plane retardation value at a long wavelength, and the retardation film is preferably expressed by the following formula. (1) and equation (2) are satisfied. Re (λ) represents an in-plane retardation value with respect to light having a wavelength of λ nm.
Re (450) / Re (550) ≤ 1 (1)
1 ≦ Re (630) / Re (550) (2)
When the retardation film is in the first form and has anti-wavelength dispersibility, it is preferable because the coloring at the time of black display on the display device is reduced, and 0.82 ≦ Re (450) / Re (550) in the formula (1). ) ≤ 0.93 is more preferable. Further, 120 ≦ Re (550) ≦ 150 is preferable.

When the retardation film is a film having an optically anisotropic layer, the polymerizable liquid crystal compound is described in "3" of the Liquid Crystal Handbook (edited by the Liquid Crystal Handbook Editorial Committee, published on October 30, 2000 by Maruzen Co., Ltd.). Among the compounds described in ".8.6 Network (completely crosslinked type)" and "6.5.1 Liquid crystal material b. Polymerizable nematic liquid crystal material", compounds having a polymerizable group, and Japanese Patent Application Laid-Open No. 2010-31223 The polymerizable liquid crystal compounds described in JP-A-2010-270108, JP-A-2011-6360, JP-A-2011-207765, JP-A-2016-81035, and International Publication No. 2017/043438 Can be mentioned.

Examples of the method for producing a retardation film from a polymer in the oriented state of a polymerizable liquid crystal compound include the method described in JP-A-2010-31223.

In the case of the second embodiment, the in-plane retardation value Re (550) may be adjusted in the range of 0 to 10 nm, preferably in the range of 0 to 5 nm, and the phase difference value Rth in the thickness direction is −10 to −−. It may be adjusted in the range of 300 nm, preferably in the range of −20 to −200 nm.
The phase difference value Rth in the thickness direction, which means the refractive index anisotropy in the thickness direction, is the phase difference value R50 and the in-plane phase difference value Re, which are measured by inclining 50 degrees with the in-plane phase advance axis as the inclination axis. Can be calculated from. That is, the retardation value Rth in the thickness direction is the in-plane retardation value Re, the retardation value R50 measured by inclining 50 degrees with the phase advance axis as the tilt axis, the thickness d of the retardation film, and the retardation film. From the average refractive index n ₀ , n _x , _ny and n _z can be obtained by the following equations (4) to (6), and these can be substituted into the equation (3) for calculation.

Rth = [(n _x + n _y ) / 2- _nz ] x d (3)
Re = (n _{x −} n _y ) × d (4)
R50 = (n _{x −} n _y ') × d / cos (φ) (5)
(n _x + n _y + n _z ) / 3 = n ₀ (6)
here,
φ = sin ^-1 [sin (40 °) / n ₀ ]
n _y '= n _y x n _z / [ _ny ² x sin ² (φ) + n _z ² x cos ² (φ)] ^1/2

The retardation film may be a multilayer film having two or more layers. For example, a protective film is laminated on one side or both sides of a retardation film, and two or more retardation films are laminated via an adhesive or an adhesive.

[4] First Cured Product Layer The first cured product layer 15 is a cured product layer composed of a cured product of the curable composition (S). The curable composition (S) is as described above. The curable composition (S) can be cured by heat, for example.

[5] Thermoplastic Resin Film The first thermoplastic resin film 10 and the second thermoplastic resin film 20 are each a translucent (preferably optically transparent) thermoplastic resin, for example, a chain polyolefin resin. Polypropylene-based resins such as (polypropylene-based resins, etc.), cyclic polyolefin-based resins (norbornen-based resins, etc.); Cellulosic ester-based resins such as triacetyl cellulose and diacetyl cellulose; polyester-based resins such as polyethylene terephthalate, polyethylene naphthalate, and thermoplastics. A film made of a resin; a polycarbonate-based resin; a (meth) acrylic-based resin; a polystyrene-based resin; or a mixture thereof, a copolymer, or the like can be used.

The first thermoplastic resin film 10 and the second thermoplastic resin film 20 may be either an unstretched film or a uniaxially or biaxially stretched film, respectively. The biaxial stretching may be a simultaneous biaxial stretching that simultaneously stretches in two stretching directions, or may be a sequential biaxial stretching that stretches in a second direction different from this after stretching in the first direction.
The first thermoplastic resin film 10 and / or the second thermoplastic resin film 20 may be a protective film that plays a role of protecting the optical layer 30, or is a protective film that also has an optical function such as a retardation film. You can also do it.
For the retardation film, the description in [3] above is cited.

Examples of the chain polyolefin resin include homopolymers of chain olefins such as polyethylene resin and polypropylene resin, and copolymers composed of two or more kinds of chain olefins.

The cyclic polyolefin-based resin is a general term for resins containing norbornene, tetracyclododecene (also known as dimethanooctahydronaphthalene), or a cyclic olefin typified by a derivative thereof as a polymerization unit. Examples of the cyclic polyolefin resin include a ring-opening (co) polymer of a cyclic olefin and a hydrogenated product thereof, an addition polymer of a cyclic olefin, a cyclic olefin and a chain olefin such as ethylene and propylene, or an aromatic compound having a vinyl group. Examples thereof include copolymers of the above, and modified (co) copolymers obtained by modifying these with unsaturated carboxylic acids or derivatives thereof.
Of these, a norbornene-based resin using a norbornene-based monomer such as norbornene or a polycyclic norbornene-based monomer is preferably used as the cyclic olefin.

The cellulose ester-based resin is a resin in which at least a part of the hydroxyl groups in cellulose is acetic acid esterified, and a mixed ester in which a part is acetic acid esterified and a part is esterified with another acid. May be good. The cellulosic ester resin is preferably an acetyl cellulosic resin.
Examples of the acetyl cellulosic resin include triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, and cellulose acetate butyrate.

The polyester-based resin is a resin other than the above-mentioned cellulose ester-based resin having an ester bond, and is generally composed of a polyvalent carboxylic acid or a polycondensate of a derivative thereof and a polyhydric alcohol.
Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexanedimethylterephthalate, and polycyclohexanedimethylnaphthalate.
Of these, polyethylene terephthalate is preferably used from the viewpoints of mechanical properties, solvent resistance, scratch resistance, cost and the like. Polyethylene terephthalate refers to a resin in which 80 mol% or more of the repeating unit is composed of ethylene terephthalate, and is a constituent unit derived from other copolymerization components (dicarboxylic acid component such as isophthalic acid; diol component such as propylene glycol). May include.

The polycarbonate resin is a polyester formed from carbonic acid and glycol or bisphenol. Among them, aromatic polycarbonate having a diphenylalkane in the molecular chain is preferably used from the viewpoint of heat resistance, weather resistance and acid resistance.
Examples of polycarbonate include 2,2-bis (4-hydroxyphenyl) propane (also known as bisphenol A), 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) cyclohexane, and 1, Examples thereof include polycarbonate derived from bisphenols such as 1-bis (4-hydroxyphenyl) isobutane and 1,1-bis (4-hydroxyphenyl) ethane.

The (meth) acrylic resin is a polymer containing a structural unit derived from the (meth) acrylic monomer, and examples of the (meth) acrylic monomer include methacrylic acid ester and acrylic acid ester.

Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, n-, i- or t-butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, and 2-hydroxyethyl methacrylate. And so on.

Examples of the acrylic acid ester include ethyl acrylate, n-, i- or t-butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate and the like. ..

The (meth) acrylic resin may be a polymer consisting of only structural units derived from the (meth) acrylic monomer, or may contain other structural units.

In one preferred embodiment, the (meth) acrylic resin comprises methyl methacrylate as a copolymerization component, or comprises methyl methacrylate and methyl acrylate.
In one preferred embodiment, the (meth) acrylic resin can be a polymer containing a methacrylic acid ester as a main monomer (containing 50% by mass or more), and the methacrylic acid ester and other copolymerization components. Is preferably a copolymer in which is copolymerized.

The glass transition temperature of the (meth) acrylic resin is preferably 80 ° C. or higher and 160 ° C. or lower. The glass transition temperature is the polymerization ratio of the methacrylic acid ester-based monomer and the acrylic acid ester-based monomer, the carbon chain length of each ester group, the type of functional group having them, and the polyfunctional monomer for the entire monomer. It can be controlled by adjusting the polymerization ratio of the monomer.

It is also effective to introduce a ring structure into the main chain of the polymer as a means for raising the glass transition temperature of the (meth) acrylic resin. The ring structure is preferably a heterocyclic structure such as a cyclic acid anhydride structure, a cyclic imide structure and a lactone structure. Specific examples thereof include a cyclic acid anhydride structure such as a glutaric anhydride structure and a succinic anhydride structure; a cyclic imide structure such as a glutarimide structure and a succinic anhydride structure; and a lactone ring structure such as butyrolactone and valerolactone.
As the content of the ring structure in the main chain is increased, the glass transition temperature of the (meth) acrylic resin tends to be increased.
The cyclic acid anhydride structure and the cyclic imide structure are introduced by copolymerizing a monomer having a cyclic structure such as maleic anhydride and maleimide; the cyclic acid anhydride structure is formed by a dehydration / demethanol condensation reaction after polymerization. Method of introduction; It can be introduced by a method of reacting an amino compound to introduce a cyclic imide structure or the like.
For a resin (polymer) having a lactone ring structure, after preparing a polymer having a hydroxyl group and an ester group in a polymer chain, the hydroxyl group and the ester group in the obtained polymer are required by heating. Therefore, it can be obtained by a method of forming a lactone ring structure by cyclization condensation in the presence of a catalyst such as an organic phosphorus compound.

The (meth) acrylic resin and the thermoplastic resin film formed from the (meth) acrylic resin may contain additives, if necessary. Examples of the additive include a lubricant, an antiblocking agent, a heat stabilizer, an antioxidant, an antistatic agent, a lightproofing agent, an impact resistance improving agent, a surfactant and the like.
These additives can also be used when a thermoplastic resin other than the (meth) acrylic resin is used as the thermoplastic resin constituting the thermoplastic resin film.

The (meth) acrylic resin may contain acrylic rubber particles which are impact improving agents from the viewpoint of film forming property on the film, impact resistance of the film, and the like. Acrylic rubber particles are particles containing an elastic polymer mainly composed of an acrylic acid ester as an essential component, and have a single-layer structure substantially consisting of only this elastic polymer, or one elastic polymer. Examples thereof include a multi-layer structure having layers.

Examples of the elastic polymer include a crosslinked elastic copolymer containing alkyl acrylate as a main component and copolymerizing another copolymerizable vinyl-based monomer and a crosslinkable monomer.
Examples of the alkyl acrylate that is the main component of the elastic polymer include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like, which have an alkyl group having 1 or more and 8 or less carbon atoms. An alkyl acrylate having an alkyl group having 4 or more carbon atoms is preferably used.

Examples of the other vinyl-based monomer copolymerizable with the alkyl acrylate include a compound having one polymerizable carbon-carbon double bond in the molecule, and more specifically, methyl methacrylate. Methacrylic acid esters such as, aromatic vinyl compounds such as styrene; vinyl cyan compounds such as acrylonitrile, and the like.

Examples of the crosslinkable monomer include a crosslinkable compound having at least two polymerizable carbon-carbon double bonds in the molecule, and more specifically, ethylene glycol di (meth) acrylate and butane. Examples thereof include (meth) acrylates of polyhydric alcohols such as diol di (meth) acrylate; alkenyl esters of (meth) acrylic acid such as allyl (meth) acrylate; and divinylbenzene.

A laminate of a film made of a (meth) acrylic resin containing no rubber particles and a film made of a (meth) acrylic resin containing rubber particles is used as a thermoplastic resin film to be bonded to the optical layer 30. You can also. Further, a (meth) acrylic resin layer is formed on one side or both sides of a retardation-developing layer made of a resin different from the (meth) acrylic resin, and the one in which the retardation is expressed is bonded to the optical layer 30. It can also be a thermoplastic resin film.

The first thermoplastic resin film 10 and the second thermoplastic resin film 20 are each one or more thermoplastics selected from the group consisting of a cellulose ester resin, a polyester resin, a (meth) acrylic resin, and a cyclic polyolefin resin. A film containing a resin is preferable, and a cellulose ester-based resin film, a polyester-based resin film, a (meth) acrylic-based resin film, or a cyclic polyolefin-based resin film is more preferable.

The first thermoplastic resin film 10 and / or the second thermoplastic resin film 20 contains an ultraviolet absorber, an infrared absorber, an organic dye, a pigment, an inorganic dye, an antioxidant, an antistatic agent, a surfactant, a lubricant, and the like. It may contain a dispersant, a heat stabilizer and the like. When the optical laminate is applied to an image display device, a thermoplastic resin film containing an ultraviolet absorber is placed on the visual side of an image display element (for example, a liquid crystal cell or an organic EL display element) to display the image. Deterioration due to ultraviolet rays can be suppressed.
Examples of the ultraviolet absorber include salicylic acid ester compounds, benzophenone compounds, benzotriazole compounds, cyanoacrylate compounds, nickel complex salt compounds and the like.

The first thermoplastic resin film 10 and the second thermoplastic resin film 20 may be films made of the same thermoplastic resin, or may be films made of different thermoplastic resins. The first thermoplastic resin film 10 and the second thermoplastic resin film 20 may be the same or different in terms of thickness, presence / absence of additives, their types, retardation characteristics, and the like.

The first thermoplastic resin film 10 and / or the second thermoplastic resin film 20 has a hard coat layer, an antiglare layer, an antireflection layer, a light diffusion layer, and an antistatic layer on its outer surface (the surface opposite to the optical layer 30). A surface treatment layer (coating layer) such as an antifouling layer, an antifouling layer, and a conductive layer may be provided.

The thickness of the first thermoplastic resin film 10 and the second thermoplastic resin film 20 is usually 5 μm or more and 200 μm or less, preferably 10 μm or more and 120 μm or less, more preferably 10 μm or more and 85 μm or less, and further preferably 15 μm or more and 65 μm or less. Is. The thickness of the first thermoplastic resin film 10 and the second thermoplastic resin film 20 may be 50 μm or less, or 40 μm or less, respectively. Reducing the thickness of the first thermoplastic resin film 10 and the second thermoplastic resin film 20 is advantageous for reducing the thickness of the optical laminate (polarizing plate) and the image display device including the optical laminate (polarizing plate).

On the surface to which the curable composition of the first thermoplastic resin film 10 and the second thermoplastic resin film 20 is applied, from the viewpoint of improving adhesion, surfaces such as saponification treatment, plasma treatment, corona treatment, and primer treatment are performed. The modification treatment may be performed, or the surface modification treatment may not be performed from the viewpoint of simplifying the process. The surface modification treatment may be performed on the bonding surface of the optical layer 30 instead of the bonding surface of the thermoplastic resin film or together with the bonding surface.
When the first thermoplastic resin film 10 or the second thermoplastic resin film 20 is a cellulose ester-based resin film, it is preferable to carry out a saponification treatment from the viewpoint of improving adhesion. Examples of the saponification treatment include a method of immersing in an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide.

[6] Second Curable Layer The curable composition forming the second cured layer 25 may be the above-mentioned curable composition (S), or may be another curable composition different from this. There may be. The second cured product layer 25 is preferably a cured product layer of the curable composition (S) from the viewpoint of optical durability of the optical laminate in a high temperature and high humidity environment.
When the first cured product layer 15 and the second cured product layer 25 are formed from the curable composition (S), these curable compositions may have the same composition or different compositions. You may.
Other curable compositions include known water-based compositions (including water-based adhesives) in which a curable resin component is dissolved or dispersed in water, and known active energy rays containing an active energy ray-curable compound. Examples thereof include a curable composition (including an active energy ray-curable adhesive) and the like.

Examples of the resin component contained in the aqueous composition include polyvinyl alcohol-based resin and urethane resin.
The aqueous composition containing a polyvinyl alcohol-based resin is a curable component such as a polyhydric aldehyde, a melamine-based compound, a zirconia compound, a zinc compound, glyoxal, a glyoxal derivative, and a water-soluble epoxy resin in order to improve adhesion and adhesiveness. And a cross-linking agent can be further contained.
Examples of the aqueous composition containing the urethane resin include an aqueous composition containing a polyester ionomer type urethane resin and a compound having a glycidyloxy group. The polyester-based ionomer type urethane resin is a urethane resin having a polyester skeleton, in which a small amount of an ionic component (hydrophilic component) is introduced.

The active energy ray-curable composition is a composition that is cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays. When an active energy ray-curable composition is used, the second cured product layer 25 is a cured product layer of the composition.

The active energy ray-curable composition can be a composition containing an epoxy compound that is cured by cationic polymerization as a curable component, and preferably an ultraviolet curable composition containing such an epoxy compound as a curable component. It is a thing. The epoxy-based compound means a compound having an average of 1 or more, preferably 2 or more epoxy groups in the molecule. Only one type of epoxy compound may be used, or two or more types may be used in combination.

As the epoxy compound, a hydride epoxy compound (having an alicyclic ring) obtained by reacting epichlorohydrin with an alicyclic polyol obtained by hydrogenating the aromatic ring of an aromatic polyol. Polyglycidyl ether of polyol); an aliphatic epoxy compound such as an aliphatic polyhydric alcohol or a polyglycidyl ether of an alkylene oxide adduct thereof; an epoxy compound having one or more epoxy groups bonded to an alicyclic ring in the molecule. Examples thereof include certain alicyclic epoxy compounds.

The active energy ray-curable composition can contain, as a curable component, a (meth) acrylic compound which is radically polymerizable in place of or together with the epoxy compound. The (meth) acrylic compound is a (meth) acrylate monomer having one or more (meth) acryloyloxy groups in the molecule; obtained by reacting two or more kinds of functional group-containing compounds, and at least two in the molecule. Examples thereof include (meth) acryloyloxy group-containing compounds such as (meth) acrylate oligomers having a (meth) acryloyloxy group.

When the active energy ray-curable composition contains an epoxy-based compound that is cured by cationic polymerization as a curable component, it preferably contains a photocationic polymerization initiator. Examples of the photocationic polymerization initiator include aromatic diazonium salts; onium salts such as aromatic iodonium salts and aromatic sulfonium salts; and iron-allene complexes.
When the active energy ray-curable composition contains a radically polymerizable component such as a (meth) acrylic compound, it preferably contains a photoradical polymerization initiator. Examples of the photoradical polymerization initiator include an acetophenone-based initiator, a benzophenone-based initiator, a benzoin ether-based initiator, a thioxanthone-based initiator, xanthone, fluorenone, camphorquinone, benzaldehyde, anthraquinone and the like.

The optical laminate may include an adhesive layer instead of the second cured product layer 25. That is, the second thermoplastic resin film 20 may be attached to the optical layer 30 via the pressure-sensitive adhesive layer.
As for the pressure-sensitive adhesive layer, the description of the pressure-sensitive adhesive layer described later is cited.

[7] Manufacture of Optical Laminate The optical laminate having the configuration shown in FIG. 2 is obtained by laminating and adhering the first thermoplastic resin film 10 to one surface of the optical layer 30 via the first cured product layer 15. It can be obtained, and by further laminating and adhering the second thermoplastic resin film 20 to the other surface of the optical layer 30 via the second cured product layer 25, an optical laminate having the configuration shown in FIG. 3 can be obtained. Can be done.
When producing an optical laminate having both the first thermoplastic resin film 10 and the second thermoplastic resin film 20, these films may be laminated and bonded one side at a time step by step, or the films on both sides may be laminated and bonded at the same time. It may be laminated and bonded.

As a method of adhering the optical layer 30 and the first thermoplastic resin film 10 to one or both of the bonding surfaces of the optical layer 30 and the first thermoplastic resin film 10, the curable composition (S) is applied. Examples thereof include a method of coating, laminating the other laminating surface on the laminating surface, and pressing from above and below using a laminating roll or the like for laminating.
For coating the curable composition (S), for example, various coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater can be used. Further, even in a method in which the optical layer 30 and the first thermoplastic resin film 10 are continuously supplied so that the bonding surfaces of both are on the inside, and the curable composition (S) is cast between them. Good.

After the optical layer 30 and the first thermoplastic resin film 10 are bonded together, a heat treatment is performed on the laminate containing the optical layer 30, the first cured product layer 15, and the first thermoplastic resin film 10. Is preferable. The temperature of the heat treatment is, for example, 40 ° C. or higher and 100 ° C. or lower, preferably 50 ° C. or higher and 90 ° C. or lower. The solvent contained in the curable composition layer can be removed by heat treatment. In addition, the heat treatment can allow the curing / crosslinking reaction of the curable composition to proceed.

The above bonding method can also be applied to bonding the optical layer 30 and the second thermoplastic resin film 20.

When an active energy ray-curable composition is used as the curable composition constituting the second cured product layer, the curable composition layer is dried as necessary and then irradiated with active energy rays to form the curable composition. Harden the material layer.
The light source used for irradiating the active energy beam may be any light source capable of generating ultraviolet rays, electron beams, X-rays and the like. In particular, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, and the like having an emission distribution having a wavelength of 400 nm or less are preferably used.

As shown in FIG. 1, an optical laminate having no first thermoplastic resin film on the first cured product layer 15 was obtained by coating the surface of the optical layer 30 with the curable composition (S). The laminate can be produced, for example, by subjecting the laminate to heat treatment at 80 ° C. for 300 seconds with a hot air dryer. Further, the optical laminate shown in FIG. 1 is also produced by producing a laminate composed of a separate film / curable composition (S) / optical layer 30, peeling off the separate film, and then performing heat treatment. be able to.

The thickness of the first cured product layer 15 and the second cured product layer 25 formed from the curable composition (S) is, for example, 1 nm or more and 20 μm or less, preferably 5 nm or more and 10 μm or less, and more preferably 10 nm or more. It is 5 μm or less, more preferably 20 nm or more and 2 μm or less. The cured product layer formed from the above-mentioned known aqueous composition can also have the same thickness.
The thickness of the cured product layer formed from the active energy ray-curable composition is, for example, 10 nm or more and 20 μm or less, preferably 100 nm or more and 10 μm or less, and more preferably 500 nm or more and 5 μm or less.
The first cured product layer 15 and the second cured product layer 25 may have the same thickness or may be different in thickness.

[8] Other Components of Optical Laminate [8-1] Optical Functional Film The optical laminate has optical functionality other than the optical layer 30 (for example, a polarizer) for imparting a desired optical function. A film can be provided, a preferred example thereof being a retardation film.
As described above, the first thermoplastic resin film 10 and / or the second thermoplastic resin film 20 can also serve as a retardation film, but a retardation film can also be laminated separately from these films. In the latter case, the retardation film is the first thermoplastic resin film 10, the second thermoplastic resin film 20, the first cured product layer 15 and / or the second cured product layer 25 via the adhesive layer and the adhesive layer. Can be laminated on the outer surface of. For the retardation film, the description in [3] above is cited.

Examples of other optical functional films (optical members) that can be included in an optical laminate such as a polarizing plate include a condenser plate, a brightness improving film, a reflective layer (reflective film), a semi-transmissive reflective layer (semi-transmissive reflective film), A light diffusing layer (light diffusing film) or the like.

The condensing plate is used for the purpose of controlling the optical path, and can be a prism array sheet, a lens array sheet, a sheet with dots, or the like.

The brightness improving film is used for the purpose of improving the brightness in an image display device to which an optical laminate such as a polarizing plate is applied. Specifically, a reflective polarizing separation sheet designed to generate anisotropy in reflectance by laminating a plurality of thin films having different refractive index anisotropy, an alignment film of cholesteric liquid crystal polymer, and its orientation. Examples thereof include a circularly polarized light separation sheet in which a liquid crystal layer is supported on a base film.

The reflective layer, the semi-transmissive reflective layer, and the light diffusing layer are provided to make the polarizing plate a reflective, semi-transmissive, and diffuse optical member, respectively. The reflective polarizing plate is used in a liquid crystal display device of a type that reflects and displays incident light from the viewing side, and since a light source such as a backlight can be omitted, the liquid crystal display device can be easily made thinner. The transflective polarizing plate is used in a liquid crystal display device of a type that displays light from a backlight in a dark place as a reflective type in a bright place. Further, the diffusion type polarizing plate is used for a liquid crystal display device that imparts light diffusivity and suppresses display defects such as moire. The reflective layer, the transflective reflective layer and the light diffusing layer can be formed by a known method.

[8-2] Adhesive Layer The optical laminate can include an adhesive layer. Examples of the pressure-sensitive adhesive layer include a pressure-sensitive adhesive layer for bonding an optical laminate to an image display element such as a liquid crystal cell or an organic EL display element, or another optical member. The pressure-sensitive adhesive layer is the outer surface of the optical layer 30 in the optical laminate having the configuration shown in FIGS. 1 and 2, and the first thermoplastic resin film 10 or the second thermoplastic in the optical laminate having the configuration shown in FIG. The outer surface of the resin film 20, the outer surface of the first cured product layer 15 or the second thermoplastic resin film 20 in the optical laminate having the configuration shown in FIG. 4, and the first curing in the optical laminate having the configuration shown in FIG. It can be laminated on the outer surface of the material layer 15 or the second cured product layer 25.
FIG. 6 shows an example in which the pressure-sensitive adhesive layer 40 is laminated on the outer surface of the second thermoplastic resin film 20 of the optical laminate having the configuration shown in FIG.

As the pressure-sensitive adhesive used for the pressure-sensitive adhesive layer, a (meth) acrylic resin, a silicone-based resin, a polyester-based resin, a polyurethane-based resin, a polyether-based resin, or the like as a base polymer can be used. Among them, a (meth) acrylic pressure-sensitive adhesive is preferable from the viewpoints of transparency, adhesive strength, reliability, weather resistance, heat resistance, reworkability and the like.
The (meth) acrylic pressure-sensitive adhesive includes a (meth) acrylic acid alkyl ester having an alkyl group having 20 or less carbon atoms such as a methyl group, an ethyl group, an n-, i- or t-butyl group, and (meth). A weight average molecular weight of a functional group-containing (meth) acrylic monomer such as acrylic acid or hydroxyethyl (meth) acrylic acid blended so that the glass transition temperature is preferably 25 ° C. or lower, more preferably 0 ° C. or lower. A (meth) acrylic resin having a value of 100,000 or more is useful as a base polymer.

For the formation of the pressure-sensitive adhesive layer on the optical laminate, for example, the pressure-sensitive adhesive composition is dissolved or dispersed in an organic solvent such as toluene or ethyl acetate to prepare a pressure-sensitive adhesive liquid, which is directly applied to the target surface of the optical laminate. A method of forming an adhesive layer by coating, a method of forming an adhesive layer in a sheet shape on a separate film that has been subjected to a mold release treatment, and a method of transferring it to a target surface of an optical laminate, etc. Can be done by
The thickness of the pressure-sensitive adhesive layer is determined according to the adhesive strength and the like, but a range of 1 μm or more and 50 μm or less is appropriate, and preferably 2 μm or more and 40 μm or less.

The optical laminate may include the above separate film. The separate film can be a film made of a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, a polyester resin such as polyethylene terephthalate, or the like. Of these, a polyethylene terephthalate stretched film is preferable.

The pressure-sensitive adhesive layer contains, if necessary, a filler made of glass fiber, glass beads, resin beads, metal powder or other inorganic powder, a pigment, a colorant, an antioxidant, an ultraviolet absorber, an antistatic agent and the like. be able to.

[8-3] Protect film The surface of the optical laminate (typically, the first thermoplastic resin film 10, the second thermoplastic resin film 20, the first cured product layer 15 and / or the second cured product layer) A protective film for protecting the surface of 25) can be included. After the optical laminate is attached to, for example, an image display element or another optical member, the protective film is peeled off and removed together with the adhesive layer contained therein.

The protective film is composed of, for example, a base film and an adhesive layer laminated on the base film. The above description is cited for the pressure-sensitive adhesive layer.
The resin constituting the base film is, for example, a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, a polyester resin such as polyethylene terephthalate or polyethylene naphthalate, or a thermoplastic resin such as a polycarbonate resin. be able to. A polyester resin such as polyethylene terephthalate is preferable.

<Image display device>
The optical laminate according to the present invention can be applied to an image display device such as a liquid crystal display device or an organic electroluminescence (EL) display device. In this case, the image display device includes an optical laminate and an image display element. Examples of the image display element include a liquid crystal cell and an organic EL display element. As these image display elements, conventionally known ones can be used.

When the optical laminate which is a polarizing plate is applied to a liquid crystal display device, the optical laminate may be arranged on the backlight side (back side) of the liquid crystal cell, or may be arranged on the visual side. It may be placed in both of them. When the optical laminate, which is a polarizing plate, is applied to an organic EL display device, the optical laminate is usually arranged on the visual side of the organic EL display element.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" and "part" in Examples and Comparative Examples are mass% and parts by mass.

[Manufacturing example: Fabrication of polarizer]
After immersing a 60 μm-thick polyvinyl alcohol film (average degree of polymerization: about 2,400, saponification degree: 99.9 mol% or more) in pure water at 30 ° C., the mass ratio of iodine / potassium iodide / water is increased. It was immersed in an aqueous solution at 30 ° C. of 0.02 / 2/100. Then, it was immersed in an aqueous solution at 56.5 ° C. having a mass ratio of potassium iodide / boric acid / water of 12/5/100. Subsequently, the mixture was washed with pure water at 8 ° C. and then dried at 65 ° C. to obtain a polarizer having a thickness of 23 μm in which iodine was adsorbed and oriented on a polyvinyl alcohol film. The stretching was mainly carried out in the steps of iodine staining and boric acid treatment, and the total stretching ratio was 5.5 times.

[Examples 1 to 3, Comparative Example 1]
(1) Preparation of curable composition A curable composition (adhesive aqueous solution) was prepared by mixing the components shown in Table 1 with pure water as an aqueous solvent in the blending amount shown in Table 1. The unit of the blending amount of each component shown in Table 1 is a mass part, and the blending amount of each component is the amount in terms of solid content. In Examples 1 to 3 and Comparative Examples 1 to 3, the concentration of the aqueous resin (A) in the obtained curable composition was 5.0% by mass.

(2) Preparation of Polarizing Plate A triacetyl cellulose (TAC) film [trade name "KC4UAW" manufactured by Konica Minolta Opto Co., Ltd., thickness: 40 μm] is saponified on one side and then on the saponified surface. The curable composition prepared in (1) above is coated with a bar coater, and a zero retardation film made of a cyclic polyolefin resin [trade name "ZEONOR" manufactured by Nippon Zeon Co., Ltd., thickness: 23 μm] is used. One surface was corona-treated, and the curable composition prepared in (1) above was coated on the corona-treated surface using a bar coater. A saponified TAC film is laminated on one surface of the polarizer and a corona-treated zero retardation film is laminated on the other surface so that the curable composition layer is on the polarizer side, so that the zero retardation is achieved. A laminate having a layer structure of a film / curable composition layer / polarizer / curable composition layer / TAC film was obtained. By heat-treating this laminate at 80 ° C. for 300 seconds with a hot air dryer, a polarizing plate having a layer structure of zero retardation film / cured product layer / polarizer / cured product layer / TAC film can be obtained. Made. The thickness of the cured product layer in the produced polarizing plate was 20 to 60 nm per layer.

(3) Evaluation of Optical Durability After cutting the obtained polarizing plate into a size of 30 mm × 30 mm, it is attached to a glass substrate via a (meth) acrylic adhesive on the zero retardation film side to measure a sample. Got The layer structure of the measurement sample is a glass substrate / (meth) acrylic pressure-sensitive adhesive layer / zero retardation film / cured product layer / polarizer / cured product layer / TAC film. A non-alkali glass substrate [trade name "Eagle XG" manufactured by Corning Inc.] was used as the glass substrate.
The obtained measurement sample was measured for MD transmittance and TD transmittance in the wavelength range of 380 to 780 nm using a spectrophotometer with an integrating sphere [product name "V7100" manufactured by JASCO Corporation], and each wavelength was measured. The degree of polarization in was calculated. The calculated degree of polarization is corrected for luminosity factor by the 2 degree field (C light source) of JIS Z 8701: 1999 "Color display method-XYZ color system and X10Y10Z10 color system", and the luminosity factor is corrected before the durability test. The degree of polarization Py was determined. The measurement sample was set in a spectrophotometer with an integrating sphere so that the TAC film side of the polarizing plate was the detector side and the light entered from the glass substrate side.

The degree of polarization (%) is calculated by the following formula:
Polarization degree (λ) = 100 × (Tp (λ) -Tc (λ)) / (Tp (λ) + Tc (λ))
Defined in.
Tp (λ) is the transmittance (%) of the measurement sample measured in relation to the linearly polarized light of the incident wavelength λ (nm) and the parallel Nicol.
Tc (λ) is the transmittance (%) of the measurement sample measured in relation to the linearly polarized light of the incident wavelength λ (nm) and the cross Nicol.

Next, this measurement sample was placed in a high temperature and high humidity environment with a temperature of 85 ° C. and a relative humidity of 85% RH for 500 hours, and then subjected to a durability test in which the measurement sample was placed in an environment with a temperature of 23 ° C. and a relative humidity of 50% RH for 24 hours. .. After the durability test, the luminosity factor correction polarization degree Py was determined by the same method as before the durability test.
The absolute value (| ΔPy |) of the difference between the luminosity factor correction polarization Py after the durability test and the luminosity factor correction polarization Py before the durability test was calculated. The calculated values of | ΔPy | are shown in Table 1.
The smaller the value of | ΔPy |, the better the optical durability in a high temperature and high humidity environment. In each of the Examples and Comparative Examples, the difference between the luminosity factor correction polarization Py after the durability test and the luminosity factor correction polarization Py before the durability test showed a negative value.

(4) Evaluation of Adhesion The obtained polarizing plate was bonded to a glass substrate on the zero retardation film side via a (meth) acrylic pressure-sensitive adhesive to prepare a polarizing plate with a pressure-sensitive adhesive layer. A test piece having a width of 25 mm and a length of about 200 mm was cut from the obtained polarizing plate with an adhesive layer, and the pressure-sensitive adhesive layer surface was bonded to soda glass. Next, a cutter blade is inserted between the polarizer and the TAC film, and the peeled portion is peeled 30 mm from the end in the length direction, and the peeled portion is peeled off by a universal tensile tester [“AG-1” manufactured by Shimadzu Corporation]. I grabbed it with the grip. The test piece in this state is subjected to JIS K 6854-2: 1999 "Adhesive-Peeling Adhesive Strength Test Method-Part 2: 180 ° Peeling" in an atmosphere at a temperature of 23 ° C. and a relative humidity of 55%. A 180-degree peeling test was performed at a gripping movement speed of 300 mm / min, and adhesion over a length of 170 mm excluding 30 mm of the gripped portion was determined. The results are shown in Table 1.

Details of each component shown in Table 1 are as follows.
A-1 of aqueous resin (A): Trade name "Epocross WS-300" manufactured by Nippon Catalyst Co., Ltd. [Aqueous solution of oxazoline group-containing acrylic polymer having 2-oxazoline group as side chain, solid content concentration: 10 mass %, Oxazoline value (theoretical value): 130 g solid / eq. , Oxazoline group weight (theoretical value): 7.7 mmol / g, solid, number average molecular weight: 4 × 10 ⁴ , weight average molecular weight: 12 × 10 ⁴ )]
A-2 of water-based resin (A): Trade name "Gosefimer Z-200" of Nippon Synthetic Chemical Industry Co., Ltd. [Polyvinyl alcohol modified with acetoacetyl group, average degree of polymerization: 1100, degree of saponification: 98. 5 mol% or more]
Silane compound (B): Trade name "X-12-1135" manufactured by Shin-Etsu Chemical Co., Ltd. [Silane compound having a carboxyl group and a silanol group]
Acid compound (C): Sulfuric acid

10 1st thermoplastic resin film, 15 1st cured product layer, 20 2nd thermoplastic resin film, 25 2nd cured product layer, 30 optical layer, 40 adhesive layer.

Claims

Contains water-based resin and silane compound
The aqueous resin is a curable composition containing an oxazolyl group-containing polymer.
The curable composition according to claim 1, wherein the oxazolyl group-containing polymer is an oxazolyl group-containing (meth) acrylic polymer.
The curable composition according to claim 1 or 2, further comprising an acid compound.
The curable composition according to any one of claims 1 to 3, wherein the silane compound has a silanol group.
The silane compound is further selected from the group consisting of an amino group, a carboxyl group, an epoxy group, an acetoacetyl group, a hydroxyalkyl group, a mercapto group, an oxyalkylene group, and an alkenyl group which may have a substituent. The curable composition according to claim 4, which has one or more functional groups.
The curable composition according to claim 4 or 5, wherein the silane compound further has a functional group of at least one of an amino group and a carboxyl group which may have a substituent.
The silane compound further contains a Si—O—Si bond and contains
The curable composition according to claim 5 or 6, which has the functional group in the structure of the silane compound.
A cured product layer obtained by curing the curable composition according to any one of claims 1 to 7.
Includes optical layer and first cured product layer
The first cured product layer is an optical laminate which is the cured product layer according to claim 8.
In addition, it contains a first thermoplastic resin film.
The optical laminate according to claim 9, wherein the optical layer, the first cured product layer, and the first thermoplastic resin film are laminated in this order.
Further, it contains a second cured product layer and a second thermoplastic resin film.
The optical laminate according to claim 9 or 10, wherein the second cured product layer and the second thermoplastic resin film are laminated in this order on the side of the optical layer opposite to the first cured product layer side. ..
The optical laminate according to claim 11, wherein the second cured product layer is a cured product of the curable composition according to claim 8.
The optical laminate according to any one of claims 9 to 12, wherein the optical layer is a polarizing element.
An image display device including the optical laminate according to any one of claims 9 to 13 and an image display element.