JP2019045564A - Polarizing plate - Google Patents

Abstract

To provide a polarizing plate having excellent optical durability even under a high-temperature and high-humidity environment.SOLUTION: A polarizing plate contains a polarizer and a first cured product layer in the stated order. The first cured product layer is a cured product layer of a curable composition containing an oxazoline group-containing polymer (A), a compound having a carboxyl group (B), and a compound (C) that promotes the reaction between an oxazoline group of the oxazoline group-containing polymer (A) and a carboxyl group of the compound (B).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a polarizing plate.

2. Description of the Related Art In recent years, liquid crystal display devices have been developed for mobile device applications represented by smartphones and tablet-type terminals and in-vehicle device applications represented by car navigation systems. In such applications, there is a possibility of being exposed to a harsh environment as compared with the conventional indoor TV applications, and therefore, the improvement of the device durability has become an issue.
The durability is similarly required also in the optical film which comprises a liquid crystal display etc. That is, an optical film incorporated in a liquid crystal display or the like may be placed in a high temperature or high temperature / high humidity environment, or may be placed in an environment in which high temperature and low temperature are repeated. Also, it is required that the optical characteristics do not deteriorate.
One example of the above optical film is a polarizing plate formed by laminating and laminating a thermoplastic resin film such as a protective film on one side or both sides of a polarizer using an adhesive [eg, JP 2009-008860A] (Patent Document 1)].

JP, 2009-008860, A

  An object of the present invention is to provide a polarizing plate having good optical durability even in a high temperature and high humidity environment.

The present invention provides the following polarizing plate, curable composition and cured product layer.
[1] A polarizing plate including a polarizer and a first cured product layer in this order,
The first cured material layer is
An oxazoline group-containing polymer (A),
A compound (B) having a carboxyl group,
A compound (C) which promotes the reaction of the oxazoline group of the oxazoline group-containing polymer (A) with the carboxyl group of the compound (B),
A polarizing plate, which is a cured product layer of a curable composition containing
[2] The content of the compound (B) in the curable composition is 0.01 parts by mass or more and 15 parts by mass or less in 100 parts by mass of the total amount of the oxazoline group-containing polymer (A) and the compound (B) The polarizing plate described in [1].
[3] The content of the compound (C) in the curable composition is 10 parts by mass or more and 100 parts by mass or less based on 100 parts by mass of the total amount of the oxazoline group-containing polymer (A) and the compound (B) The polarizing plate as described in [1] or [2].
[4] The polarizing plate according to any one of [1] to [3], wherein the compound (B) has two or more carboxyl groups in the molecule.
[5] The polarizing plate according to any one of [1] to [4], wherein the compound (B) has a molecular weight of 1000 or less.
[6] The polarizing plate according to any one of [1] to [5], including the polarizer, the first cured product layer, and the first thermoplastic resin film in this order.
[7] The first thermoplastic resin film contains one or more thermoplastic resins selected from the group consisting of cellulose ester resins, polyester resins, (meth) acrylic resins and cyclic polyolefin resins, [6] The polarizing plate described in.
[8] The second thermoplastic resin film, the second cured product layer, the polarizer, the first cured product layer, and the first thermoplastic resin film in this order, [6] or [7] ] The polarizing plate as described in.
[9] The polarizer according to any one of [1] to [8], which contains a polyvinyl alcohol resin.
[10] A curable composition for adhering a polarizer and a first thermoplastic resin film,
An oxazoline group-containing polymer (A),
A compound (B) having a carboxyl group,
A compound (C) which promotes the reaction of the oxazoline group of the oxazoline group-containing polymer (A) with the carboxyl group of the compound (B),
A curable composition comprising:
[11] [10], wherein the content of the compound (B) is 0.01 parts by mass or more and 15 parts by mass or less in 100 parts by mass of the total amount of the oxazoline group-containing polymer (A) and the compound (B) Curable composition as described.
[12] The content of the compound (C) is 10 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the total amount of the oxazoline group-containing polymer (A) and the compound (B) [10] The curable composition as described in [11].
[13] an oxazoline group-containing polymer (A),
A compound (B) having a carboxyl group,
A compound (C) which promotes the reaction of the oxazoline group of the oxazoline group-containing polymer (A) with the carboxyl group of the compound (B),
A cured product layer obtained by curing a curable composition containing
The cured product layer whose content of a compound (C) is 10 mass parts or more and 100 mass parts or less with respect to 100 mass parts of total amounts of an oxazoline group containing polymer (A) and a compound (B).

  It is possible to provide a polarizing plate having good optical durability even under a high temperature and high humidity environment.

It is a schematic sectional drawing which shows an example of the laminated constitution of the polarizing plate which concerns on this invention. It is a schematic sectional drawing which shows another example of the laminated constitution of the polarizing plate which concerns on this invention. It is a schematic sectional drawing which shows another example of the laminated constitution of the polarizing plate which concerns on this invention. It is a schematic sectional drawing which shows another example of the laminated constitution of the polarizing plate which concerns on this invention. It is a schematic sectional drawing which shows another example of the laminated constitution of the polarizing plate which concerns on this invention. It is a schematic sectional drawing which shows an example of the optical laminated body containing the polarizing plate which concerns on this invention.

<Polarizer>
The polarizing plate which concerns on this invention contains a polarizer and a 1st hardened | cured material layer in this order. The first cured product layer is also referred to as an oxazoline group-containing polymer (A), a compound (B) having a carboxyl group [hereinafter, referred to as a “compound (B)”. And compounds (C) [hereinafter referred to as "compounds (C)" which promote the reaction of the oxazoline group of the oxazoline group-containing polymer (A) with the carboxyl group of the compound (B). And the cured product layer of the curable composition.

  The polarizing plate according to the present invention can exhibit good optical durability even in a high temperature and high humidity environment. Good optical durability refers to the property that the optical properties (for example, the degree of polarization) of the polarizing plate are unlikely to decrease even when placed under a high temperature and high humidity environment.

[1] Configuration of Polarizing Plate An example of the layer configuration of the polarizing plate according to the present invention is shown in FIGS.
The polarizing plate shown in FIG. 1 includes a polarizer 30 and a first cured material layer 15 laminated on one surface thereof. The first cured product layer 15 can function as an overcoat layer that covers and protects the surface of the polarizer 30.
It is preferable that the polarizer 30 and the first cured product layer 15 be in direct contact with each other.

The polarizing plate shown in FIG. 2 includes a polarizer 30 and a first thermoplastic resin film 10 laminated and bonded to one side of the polarizer 30 via the first cured product layer 15. The first cured product layer 15 can function as an adhesive layer for bonding the polarizer 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 be in direct contact with each other.
It is preferable that the polarizer 30 and the first cured product layer 15 be in direct contact with each other.

The polarizing plate shown in FIG. 3 includes a polarizer 30, a first thermoplastic resin film 10 laminated and bonded to one side of the polarizer 30 via the first cured product layer 15, and the other side of the polarizer 30. And a second thermoplastic resin film 20 laminated and bonded via the second cured product layer 25. That is, the polarizing plate according to the present invention comprises the second thermoplastic resin film 20, the second cured product layer 25, the polarizer 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 respectively bond an adhesive layer for bonding the polarizer 30 and the first thermoplastic resin film 10, and bond the polarizer 30 and the second thermoplastic resin film 20. It can function as an adhesive layer.
It is preferable that the first cured product layer 15 and the first thermoplastic resin film 10 be in direct contact with each other.
It is preferable that the polarizer 30 and the first cured product layer 15 be in direct contact with each other.
It is preferable that the second cured product layer 25 and the second thermoplastic resin film 20 be in direct contact with each other.
It is preferable that the polarizer 30 and the second cured product layer 25 be in direct contact with each other.

In the polarizing plate shown in FIG. 4, a polarizer 30, a first cured product layer 15 laminated on one surface thereof, and a second cured product layer 25 on the other surface of the polarizer 30 are laminated and bonded. And a second thermoplastic resin film 20. The first cured product layer 15 can function as an overcoat layer that covers and protects the surface of the polarizer 30. The second cured product layer 25 can function as an adhesive layer for bonding the polarizer 30 and the second thermoplastic resin film 20.
It is preferable that the polarizer 30 and the first cured product layer 15 be in direct contact with each other.
It is preferable that the second cured product layer 25 and the second thermoplastic resin film 20 be in direct contact with each other.
It is preferable that the polarizer 30 and the second cured product layer 25 be in direct contact with each other.

The polarizing plate shown in FIG. 5 includes a polarizer 30, a first cured product layer 15 stacked on one side of the polarizer 30, and a second cured product layer 25 stacked on the other side of the polarizer 30. . The first cured product layer 15 and the second cured product layer 25 can function as an overcoat layer that covers and protects the surface of the polarizer 30.
It is preferable that the polarizer 30 and the first cured product layer 15 be in direct contact with each other.
It is preferable that the polarizer 30 and the second cured product layer 25 be in direct contact with each other.

  The polarizing plate according to the present invention can include other layers (or films) other than the above. As another layer, for example, an adhesive laminated on the outer surface of the first thermoplastic resin film 10, the second thermoplastic resin film 20, the first cured material layer 15, the second cured material layer 25 and / or the polarizer 30. Agent layer; a separate film (also referred to as "release film") laminated on the outer surface of the pressure-sensitive adhesive layer; first thermoplastic resin film 10, second thermoplastic resin film 20, first cured product layer 15, second Protecting film (also referred to as "surface protection film") laminated on the outer surface of the cured product layer 25 and / or the polarizer 30; first thermoplastic resin film 10, second thermoplastic resin film 20, first cured material layer 15, the optical functional film (or layer) etc. which are laminated | stacked on the outer surface of the 2nd hardened | cured material layer 25 and / or the polarizer 30 through an adhesive agent layer or an adhesive layer.

[2] First Cured Product Layer The first cured product layer 15 is a cured product layer of a curable composition (S) containing an oxazoline group-containing polymer (A), a compound (B) and a compound (C).

[2-1] Oxazoline Group-Containing Polymer (A)
The oxazoline group-containing polymer (A) is preferably a polymer having an oxazoline group in the molecule, and preferably a polymer having an oxazoline group in the side chain.
The skeleton structure of the oxazoline group-containing polymer (A) is not particularly limited, but may be, for example, one or more skeletons selected from (meth) acrylic skeleton, styrene skeleton, olefin skeleton, ester skeleton, carbonate skeleton and the like it can.
In the present specification, “(meth) acrylic” represents at least one selected from the group consisting of acrylic and methacrylic. The same applies to the notation of “(meth) acryloyl” and “(meth) acrylate”.

The oxazoline group-containing polymer (A) can have an oxazoline group on the side chain of the above-mentioned skeleton structure.
A preferred example of the oxazoline group-containing polymer (A) comprises a structural unit having a (meth) acrylic skeleton as a main component of the structural unit, and a structural unit having an oxazoline group in a side chain as a copolymer component And (x) an oxazoline group-containing (meth) acrylic polymer introduced with a structural unit of
The oxazoline group-containing polymer (A) may be one obtained by copolymerizing an oxazoline group-containing monomer, or one containing an oxazoline group by modifying the side chain functional group of the polymer.

As an oxazoline group, 2-oxazoline group, 3-oxazoline group, 4-oxazoline group etc. are mentioned, for example. The oxazoline group is preferably a 2-oxazoline group or the like.
Examples of the oxazoline group-containing monomer include 2-isopropenyl-2-oxazoline, vinyl-2-oxazoline and the like.

The weight average molecular weight of the oxazoline group-containing polymer (A) is preferably 5,000 or more, and more preferably 10,000 or more. When the weight average molecular weight is in the above range, the optical durability of the polarizing plate is improved, the adhesion between the polarizer 30 and the first cured product layer 15, the polarizer 30 and the first thermoplastic resin film 10 It can be advantageous from the viewpoint of the improvement of adhesion between The weight average molecular weight of the oxazoline group-containing polymer (A) is usually 1,000,000 (million) or less.
The weight average molecular weight of the oxazoline group-containing polymer (A) can be measured as a standard polystyrene conversion value by gel permeation chromatography (GPC).

  The amount of oxazoline groups of the oxazoline group-containing polymer (A) (the number of moles of oxazoline group per 1 g of the solid content of the oxazoline group-containing polymer (A)) is preferably 0.4 mmol / g · solid or more. If the amount of oxazoline group is smaller than the above range, the optical durability of the polarizing plate may be reduced. From such a point of view, the oxazoline group content of the oxazoline 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 oxazoline group is not particularly limited, but is usually 50 mmol / g · solid or less.

  The oxazoline group-containing polymer (A) is preferably an aqueous system, that is, a water-soluble polymer, or a water-dispersible polymer. From the viewpoint of the optical properties of the first cured product layer 15, the oxazoline group-containing polymer (A) is preferably a water-soluble polymer.

A commercially available product may be used as the oxazoline group-containing polymer (A). Specifically, oxazoline group-containing acrylic polymers such as Epocross WS-300, Epocross WS-500, Epocross WS-700 (all trade names) manufactured by Nippon Shokubai Co., Ltd .; Epocross K-1000 series made by Nippon Shokuhin Co., Ltd. Epocross Examples include oxazoline group-containing acrylic / styrene polymers such as K-2000 series and Epocross RPS series (all trade names).
The oxazoline group-containing polymer (A) can be used in combination of two or more.
Optical durability and optical properties of the polarizing plate, adhesion between the polarizer 30 and the first cured product layer 15, adhesion between the polarizer 30 and the first thermoplastic resin film 10, and first curing From the viewpoint of the water resistance of the product layer 15, the oxazoline group-containing polymer (A) is preferably an oxazoline group-containing acrylic polymer such as Epocross WS-300, Epocross WS-500, or Epocross WS-700.

The content of the oxazoline group-containing polymer (A) is preferably 60% by mass or more and 95% by mass or less, more preferably 65% by mass or more, when the solid content concentration of the curable composition (S) is 100% by mass. It is 90 mass% or less, more preferably 70 mass% or more and 85 mass% or less. When the content of the oxazoline group-containing polymer (A) is within the above range, the optical durability of the polarizing plate, the adhesion between the polarizer 30 and the first cured product layer 15, the polarizer 30, and It is preferable from the viewpoint of the adhesiveness between the first thermoplastic resin film 10 and the first thermoplastic resin film 10.
The solid content concentration refers to the total concentration of components other than the solvent contained in the curable composition (S).

[2-2] Compound (B)
The compound (B) which has a carboxyl group is a compound which has a carboxyl group which can react with the oxazoline group of oxazoline group containing polymer (A). The carboxyl group as referred to herein also includes a derivative of a carboxyl group.
Derivatives of carboxyl groups include carboxylate anion groups. Examples of the cation to be a counter ion of a carboxylate anion group include metal ions such as lithium ion, sodium ion and potassium ion; and organic cations such as ammonium ion, sulfonium ion and phosphonium ion.
The curable composition (S) may contain one type of compound (B) or may contain two or more types of compound (B).

  Among them, the compound (B) has an optical durability of the polarizing plate, an adhesion between the polarizer 30 and the first cured product layer 15, and an adhesion between the polarizer 30 and the first thermoplastic resin film 10. And from the viewpoint of enhancing the water resistance of the first cured product layer 15, it is preferably a compound (polyfunctional carboxylic acid compound) having two or more carboxyl groups (or derivatives thereof) in the molecule.

  An example of a polyfunctional carboxylic acid compound is a dicarboxylic acid compound. Examples of dicarboxylic acid compounds include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, tartaric acid, glutamic acid, malic acid and maleic acid Acid, fumaric acid, itaconic acid, muconic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid Acids, 2,5-pyridinedicarboxylic acid, 3,5-pyridinedicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenylmethanedicarboxylic acid, oxaloacetic acid, methyl fumaric acid, 2,6-pyridinedicarboxylic acid and the like.

  Another example of the polyfunctional carboxylic acid compound is a tricarboxylic acid compound. Examples of tricarboxylic acid compounds include citric acid, aconitic acid, propane-1,2,3-tricarboxylic acid, trimellitic acid, trimesic acid, hemimellitic acid, biphenyl-3,4 ', 5-tricarboxylic acid, 1,3, 5-cyclohexane tricarboxylic acid etc. are mentioned.

  Still another example of the polyfunctional carboxylic acid compound is a tetracarboxylic acid compound. As a tetracarboxylic acid compound, pyromellitic acid, diphenyl sulfone tetracarboxylic acid, biphenyl tetracarboxylic acid, benzophenone tetracarboxylic acid, naphthalene tetracarboxylic acid, thiophene tetracarboxylic acid, butane tetracarboxylic acid, 1,2,4,5- Tetrakis (4-carboxyphenyl) benzene etc. are mentioned.

In the polyfunctional carboxylic acid compounds exemplified above, at least one carboxyl group may be a derivative thereof.
The compound (B) may have another functional group other than a carboxyl group. An example of another functional group is a hydroxy group.
From the viewpoint of the optical durability of the polarizing plate, the number of carboxyl groups contained in the compound (B) is preferably 2 or 3.

  The polyfunctional carboxylic acid compound may be a polymer having two or more carboxyl groups (or derivatives thereof) in the molecule. An example of the polymer is a carboxyl group-modified polymer. One example of the carboxyl group-modified polymer is a carboxyl group-modified polyvinyl alcohol polymer.

The carboxyl group-modified polyvinyl alcohol polymer is a polyvinyl alcohol polymer modified by introducing a carboxyl group or a derivative thereof into a side chain.
Derivatives of carboxyl groups include carboxylate anion groups. The example of the cation used as the counter ion of carboxylate anion group is as above-mentioned. An example of a preferred cation is sodium ion.

A polyvinyl alcohol polymer constituting the main chain of a carboxyl group-modified polyvinyl alcohol polymer is a vinyl alcohol homopolymer (completely saponified polyvinyl alcohol) obtained by saponifying polyvinyl acetate which is a homopolymer of vinyl acetate Or a partially saponified polyvinyl alcohol), or a polyvinyl alcohol copolymer obtained by saponifying a copolymer of vinyl acetate and another monomer copolymerizable therewith. It is also good.
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 carboxyl group-modified polyvinyl alcohol polymer is usually 80% by mole or more and 100% by mole or less, and preferably 85% by mole or more (eg, 88% by mole or more).
The degree of saponification of the carboxyl group-modified polyvinyl alcohol polymer can be measured according to JIS K 6726: 1994.

The modification | denaturation degree (modification amount) by the carboxyl group (or its derivative (s)) of a carboxyl group modified polyvinyl alcohol polymer is 0.1 mol% or more normally. The degree of modification of the carboxyl group-modified polyvinyl alcohol polymer is determined by the optical durability of the polarizing plate, the adhesion between the polarizer 30 and the first cured product layer 15, the polarizer 30 and the first thermoplastic resin film 10 From the viewpoint of enhancing the adhesiveness between them and the water resistance of the first cured product layer 15, it is preferably 0.5 mol% or more and 40 mol% or less, more preferably 1 mol% or more and 20 mol% or less. The degree of modification can be measured, for example, by ¹ H-NMR.

The average degree of polymerization of the carboxyl group-modified polyvinyl alcohol polymer is usually 100 or more and 3,000 or less.
The average degree of polymerization of the carboxyl group-modified polyvinyl alcohol polymer can be measured according to JIS K 6726: 1994.

In one preferred embodiment, the compound (B) has a molecular weight of 1000 or less. This molecular weight is a molecular weight calculated from a chemical structural formula, but when compound (B) is a polymer, it is a number average molecular weight measured as a standard polystyrene equivalent value by gel permeation chromatography (GPC) May be
Using the compound (B) having a molecular weight of 1000 or less may be advantageous in enhancing the optical durability of the polarizing plate. From the viewpoint of the optical durability of the polarizing plate, the molecular weight of the compound (B) is preferably 800 or less, more preferably 500 or less.
In addition, the molecular weight of the compound (B) is determined by the optical durability of the polarizing plate, the adhesion between the polarizer 30 and the first cured product layer 15, the distance between the polarizer 30 and the first thermoplastic resin film 10 It is preferably 90 or more, and more preferably 100 or more from the viewpoint of adhesion and water resistance of the first cured product layer 15.

  The compound (B) is preferably citric acid, malic acid, maleic acid or tartaric acid.

The content of the compound (B) in the curable composition (S) is preferably 100 parts by mass of the total amount of the oxazoline group-containing polymer (A) and the compound (B) from the viewpoint of enhancing the optical durability of the polarizing plate. Is 0.01 to 15 parts by mass, more preferably 0.1 to 12 parts by mass, and still more preferably 0.3 to 10 parts by mass.
When the content of the compound (B) is excessively small, it is difficult to obtain good optical durability of the polarizing plate. When the content of the compound (B) is excessively large, the optical durability of the polarizing plate, the adhesion between the polarizer 30 and the first cured product layer 15, the polarizer 30 and the first thermoplastic resin film 10 can be obtained. And / or the water resistance of the first cured product layer 15 tends to decrease.

[2-3] Compound (C)
The compound (C) is a compound that promotes the reaction of the oxazoline group of the oxazoline group-containing polymer (A) with the carboxyl group of the compound (B). The promotion referred to here includes the case of initiating the reaction.

  Preferred examples of the compound (C) include acid compounds. The acid compound may be a compound that functions as a catalyst for the reaction of the oxazoline group of the oxazoline group-containing polymer (A) with the carboxyl group of the compound (B).

Examples of the acid compound include inorganic acids such as sulfuric acid, hydrogen chloride, nitric acid, phosphoric acid, phosphorous acid and boric acid; p-toluenesulfonic acid, dodecylbenzenesulfonic acid, naphthalenesulfonic acid, methanesulfonic acid, benzenesulfonic acid, Organic acids such as phenyl phosphoric acid, sulfanilic acid, phenyl phosphonic acid, acetic acid, propionic acid and the like can be mentioned.
The curable composition (S) may contain one type of compound (C) or may contain two or more types of compound (C).
The compound (C) may be blended in the curable composition (S) as a solution (for example, an aqueous solution) containing the compound (C).

Among them, the compound (C) has an optical durability of the polarizing plate, an adhesion between the polarizer 30 and the first cured product layer 15, and an adhesion between the polarizer 30 and the first thermoplastic resin film 10. From the viewpoint of enhancing the properties, relatively strong acids are preferable, and examples of such acid compounds include sulfuric acid, hydrogen chloride (hydrochloric acid), nitric acid, p-toluenesulfonic acid and the like.
When a strong acid as described above is used as the compound (C), in particular, the adhesion between the polarizer 30 and the first cured product layer 15 and the adhesion between the polarizer 30 and the first thermoplastic resin film 10 Tend to improve.

The content of the compound (C) in the curable composition (S) is usually 6 parts by mass or more and 150 parts by mass or less based on 100 parts by mass of the total amount of the oxazoline group-containing polymer (A) and the compound (B) From the viewpoint of enhancing the optical durability of the polarizing plate, the adhesion between the polarizer 30 and the first cured product layer 15, and the adhesion between the polarizer 30 and the first thermoplastic resin film 10, The amount is preferably 10 parts by mass or more and 100 parts by mass or less, more preferably 10 parts by mass or more and 100 parts by mass or less, and still more preferably 15 parts by mass or more and 100 parts by mass or less.
In one preferable embodiment, the content of the compound (C) is 80 based on the total amount of 100 parts by mass of the oxazoline group-containing polymer (A) and the compound (B) from the viewpoint of enhancing the optical durability of the polarizing plate. It is below a mass part.

When the content of the compound (C) is excessively low, it is difficult to obtain good optical durability of the polarizing plate. In addition, when the content of the compound (C) is excessively low, the adhesion between the polarizer 30 and the first cured product layer 15 and the adhesion between the polarizer 30 and the first thermoplastic resin film 10 Tend to decrease.
When the content of the compound (C) is excessively large, the optical durability of the polarizing plate, the adhesion between the polarizer 30 and the first cured product layer 15, the polarizer 30 and the first thermoplastic resin film 10 are obtained. The adhesion between them and / or the water resistance of the first cured product layer 15 tends to be reduced.

[2-4] Other Components The curable composition (S) can contain other components other than the oxazoline group-containing polymer (A), the compound (B) and the compound (C).
As other components, curing components and crosslinking agents such as polyvalent aldehydes, melamine compounds, zirconia compounds, zinc compounds, aziridine compounds, glyoxals, glyoxal derivatives, water-soluble epoxy resins and the like; other than carboxyl group-modified polyvinyl alcohol polymers And modified additives such as coupling agents, tackifiers, antioxidants, ultraviolet absorbers, heat stabilizers, and hydrolysis inhibitors.
The curable composition (S) can contain one or more other components.

The curable composition (S) preferably contains a solvent. The solvent includes water, an organic solvent, or a mixture thereof. The solvent preferably contains water, but water and a water-soluble organic solvent may be used in combination. Examples of the organic solvent include alcohol solvents such as ethanol and 1-methoxy-2-propanol.
The main component of the solvent is preferably water. The main component means that it occupies 50% by mass or more of the total solvent.
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.

  The curable composition (S) can function as an adhesive composition. In this case, the curable composition (S) is preferably a water-based adhesive. That is, the curable composition (S) is preferably 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 . Further, even when the curable composition (S) is used to form the overcoat layer, the curable composition (S) may be a solution in which the compounding component is dissolved in a solvent containing water, It is preferable that it is a dispersion (for example, emulsion) which disperse | distributed the mixing | blending component to the 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 more preferred. When the viscosity at 25 ° C. exceeds 50 mPa · s, it is difficult to apply uniformly, which may cause uneven coating, and may cause problems such as clogging of piping.
The viscosity at 25 ° C. of the curable composition (S) can be measured by an E-type viscometer.

[3] Polarizer The polarizer 30 is a film having a function of selectively transmitting linearly polarized light in one direction from natural light.
The polarizer 30 may include a polarizer including a polyvinyl alcohol-based resin, and more specifically, may include a polarizer composed of a polyvinyl alcohol-based resin film.
As a polarizer comprised with a polyvinyl alcohol-type resin film, For example, the iodine-type polarizer which made the polyvinyl alcohol-type resin film adsorb and orientate iodine as a dichroic dye, A polyvinyl alcohol-type resin film makes a dichroic dye And dye-based polarizers in which a dichroic dye is adsorbed and oriented.
In addition, the polarizer 30 may be a coating type polarizer in which a dichroic dye in a lyotropic liquid crystal state is coated on a base film and oriented and fixed.
The above 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 30 is not limited to the absorption polarizer, and is a reflective polarizer that selectively transmits one linearly polarized light from natural light and reflects the other linearly polarized light, or the other linearly polarized light. Although it may be a scattering type polarizer that scatters, absorption type polarizers are preferable in terms of excellent visibility. Among them, a polyvinyl alcohol-based polarizer composed of a polyvinyl alcohol-based resin film is more preferable, and a polyvinyl alcohol-based polarizer having a polyvinyl alcohol-based resin film adsorbed and oriented with a dichroic dye such as iodine or a dichroic dye More preferably, a polyvinyl alcohol-based polarizer in which iodine is adsorbed and oriented to a polyvinyl alcohol-based resin film is particularly preferable.

  As polyvinyl alcohol-type resin which comprises a polyvinyl alcohol-type polarizer, what saponified polyvinyl acetate type resin can be used. Examples of polyvinyl acetate resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. 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 resin is usually 85% by mole or more and 100% by mole or less, preferably 98% by mole or more. The polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes can also be used. The average degree of polymerization of the polyvinyl alcohol 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.

  What formed such a polyvinyl alcohol-type resin into a film is used as a raw film of the polarizer 30 comprised with the polyvinyl alcohol-type resin film. The method of forming a polyvinyl alcohol-based resin into a film 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 (eg, 50 μm or less), and 5 μm or more.

  The polarizer 30 composed of a polyvinyl alcohol-based resin film is a process of uniaxially stretching a polyvinyl alcohol-based resin film; a process of adsorbing a dichroic dye by dyeing the polyvinyl alcohol-based resin film with a dichroic dye; It can manufacture by the method including the process of processing (crosslinking processing) the boric acid aqueous solution the polyvinyl alcohol-type resin film by which the color pigment was adsorbed, and the process washed with water after the treatment with boric acid aqueous solution.

  The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after the dyeing of the dichroic dye. If uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before or during the boric acid treatment. Moreover, you may uniaxially stretch in these several steps.

  In uniaxial stretching, uniaxial stretching may be performed between rolls having different peripheral speeds, or uniaxial stretching may be performed using a heat roll. The uniaxial stretching may be dry stretching in which stretching is performed in the air, or may be wet stretching in which a polyvinyl alcohol resin film is swollen using a solvent such as water. The stretching ratio is usually 3 to 8 times.

  Examples of the method of dyeing a polyvinyl alcohol-based resin film with a dichroic dye include a method of immersing the film in an aqueous solution containing a dichroic dye. As the dichroic dye, iodine or a dichroic organic dye is used. The polyvinyl alcohol-based resin film is preferably subjected to immersion treatment in water prior to the dyeing treatment.

As a dyeing processing method by iodine, a method of immersing a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide, and the like can be mentioned. The content of iodine in this aqueous solution can be 0.01 parts by mass or more and 1 part by mass or less per 100 parts by mass of water. The content of potassium iodide can be 0.5 parts by mass or more and 20 parts by mass or less per 100 parts by mass of water. Further, the temperature of the aqueous solution can be 20 ° C. or more and 40 ° C. or less.
On the other hand, as a dyeing processing method with a dichroic organic dye, a method of immersing a polyvinyl alcohol-based resin film in an aqueous solution containing a dichroic organic dye may, for example, be mentioned. The aqueous solution containing the dichroic organic dye may contain an inorganic salt such as sodium sulfate as a dyeing assistant. The content of the dichroic organic dye in this aqueous solution can be 1 × 10 ⁻⁴ parts by mass or more and 10 parts by mass or less per 100 parts by mass of water. The temperature of the aqueous solution can be 20 ° C. or more and 80 ° C. or less.

  As a boric-acid processing method after dyeing | staining with a dichroic dye, the method of immersing the dyed polyvinyl alcohol-type resin film in boric-acid containing aqueous solution etc. are mentioned. When using iodine as a dichroic dye, it is preferable that this boric-acid containing aqueous solution contains potassium iodide. The amount of boric acid in the boric acid-containing aqueous solution can be 2 parts by mass or more and 15 parts by mass or less per 100 parts by mass of water. The amount of potassium iodide in the aqueous solution can be 0.1 parts by mass or more and 20 parts by mass or less per 100 parts by mass of water. The temperature of the aqueous solution can be 50 ° C. or more, and is, for example, 50 ° C. or more and 85 ° C. or less.

The polyvinyl alcohol resin film after boric acid treatment is usually washed with water. The water washing process can be performed, for example, by immersing a boric acid-treated polyvinyl alcohol resin film in water. The temperature of water in the water washing treatment is usually 5 ° C. or more and 40 ° C. or less. After washing with water, drying treatment is performed to obtain a polarizer 30.
The drying process can be performed using a hot air dryer or a far infrared heater. By forming a cured product layer of the curable composition (S) on the surface of the polarizer 30, a polarizing plate can be obtained. As described above, the polarizing plate can further have the first thermoplastic resin film 10, the second thermoplastic resin film 20, the second cured material layer, and the like.

  Moreover, as another example of the manufacturing method of the polarizer 30, the method as described in Unexamined-Japanese-Patent No. 2000-338329 or 2012-159778 is mentioned, for example. In this method, a solution containing a polyvinyl alcohol-based resin is applied to the surface of a substrate film to form a resin layer, and then a laminated film comprising the substrate film and the resin layer is stretched, and then a dyeing treatment, a crosslinking treatment, etc. To form a polarizer layer (polarizer 30) from the resin layer. After bonding the 1st thermoplastic resin film 10 as a protective film etc. via curable composition (S) to the polarizer layer surface of this light-polarizing laminated film which consists of a base film and a polarizer layer, a base material is carried out. The film can be peeled off to obtain a polarizing plate of the configuration shown in FIG. If the 2nd thermoplastic resin film 20 is further bonded via the curable composition on the polarizer layer surface exposed by peeling of a base film, it will become a polarizing plate of the structure shown by FIG.

  The thickness of the polarizer 30 can be 40 μm or less, preferably 30 μm or less (eg, 20 μm or less, further 15 μm or less, still 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, the thin film polarizer 30 can be manufactured more easily, and the thickness of the polarizer 30 is, for example, 20 μm or less, and further. Of 15 μm or less, or even 10 μm or less or 8 μm or less. The thickness of the polarizer 30 is usually 2 μm or more. Reducing the thickness of the polarizer 30 is advantageous for reducing the thickness of the polarizing plate and hence the image display device.

[4] Thermoplastic Resin Film Each of the first thermoplastic resin film 10 and the second thermoplastic resin film 20 is a translucent (preferably optically transparent) thermoplastic resin, for example, a chain-like polyolefin resin (Polypropylene-based resin etc.), Polyolefin-based resin such as cyclic polyolefin-based resin (norbornene-based resin etc.); Cellulose ester-based resin such as triacetylcellulose and diacetylcellulose; Polyester-based such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate Resin; polycarbonate resin; (meth) acrylic resin; or a mixture of these, a copolymer, etc. can be used.

The first thermoplastic resin film 10 and the second thermoplastic resin film 20 may each be either an unstretched film or a uniaxially or biaxially stretched film. The biaxial stretching may be simultaneous biaxial stretching simultaneously stretching in two stretching directions, or sequential biaxial stretching stretching in a first direction and then stretching in a second different direction.
The first thermoplastic resin film 10 and / or the second thermoplastic resin film 20 may be a protective film having a role of protecting the polarizer 30, or may be a protective film having an optical function such as a retardation film. It can also be done.
The retardation film is an optical functional film used for the purpose of compensation of retardation by a liquid crystal cell which is an image display element. For example, an arbitrary retardation value is given by stretching (uniaxial stretching or biaxial stretching etc.) the film made of the thermoplastic resin or forming a liquid crystal layer etc. on the thermoplastic resin film. It can be made a retardation film.

  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 chain olefins.

The cyclic polyolefin-based resin is a generic term for resins containing cyclic olefin as a polymerization unit, typified by norbornene, tetracyclododecene (alias: dimethanooctahydronaphthalene) or derivatives thereof. Cyclic polyolefin-based resins include ring-opened (co) polymers of cyclic olefins and their hydrogenated products, addition polymers of cyclic olefins, cyclic olefins and linear olefins such as ethylene and propylene or aromatic compounds having a vinyl group and And copolymers thereof, and modified (co) polymers obtained by modifying these with unsaturated carboxylic acids and derivatives thereof.
Among them, a norbornene-based resin using a norbornene-based monomer such as norbornene or a polycyclic norbornene-based monomer as a cyclic olefin is preferably used.

The cellulose ester resin is a resin in which at least a part of hydroxyl groups in cellulose is acetate-esterified, and a mixed ester in which a part is acetate-esterified and a part is esterified with another acid, It is also good. The cellulose ester resin is preferably an acetyl cellulose resin.
Examples of acetyl cellulose resins include triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, and cellulose acetate butyrate.

The polyester-based resin is a resin having an ester bond and other than the above-mentioned cellulose ester-based resin, and is generally made of a polycondensate of polyvalent carboxylic acid or derivative thereof and polyvalent alcohol.
Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexanedimethyl terephthalate, polycyclohexanedimethyl naphthalate and the like.
Among them, polyethylene terephthalate is preferably used in view of mechanical properties, solvent resistance, scratch resistance, cost and the like. The polyethylene terephthalate refers to a resin in which 80 mol% or more of the repeating unit is composed of ethylene terephthalate, and may contain a constituent unit derived from another copolymerization component.

Other copolymerization components include dicarboxylic acid components and diol components.
Examples of the dicarboxylic acid component include isophthalic acid, 4,4'-dicarboxydiphenyl, 4,4'-dicarboxybenzophenone, bis (4-carboxyphenyl) ethane, adipic acid, sebacic acid, 5-sodium sulfoisophthalic acid, 1 , 4-dicarboxycyclohexane and the like.
Examples of the diol component include propylene glycol, butanediol, neopentyl glycol, diethylene glycol, cyclohexanediol, ethylene oxide adduct of bisphenol A, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like.
The dicarboxylic acid component and the diol component can also be used in combination of two or more types as needed.
Moreover, it is also possible to use together hydroxycarboxylic acids, such as p-hydroxy benzoic acid, p-hydroxy ethoxy benzoic acid, (beta) -hydroxy ethoxy benzoic acid, with the said dicarboxylic acid component and diol component.
As another copolymerization component, a small amount of a dicarboxylic acid component having an amide bond, a urethane bond, an ether bond, a carbonate bond or the like and / or a diol component may be used.

Polycarbonate resins are polyesters formed from carbonic acid and glycol or bisphenol. Among them, aromatic polycarbonates having diphenyl alkane in the molecular chain are preferably used from the viewpoints of heat resistance, weather resistance and acid resistance.
Examples of polycarbonates include 2,2-bis (4-hydroxyphenyl) propane (also known as bisphenol A), 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1, Polycarbonates derived from bisphenols such as 1-bis (4-hydroxyphenyl) isobutane, 1,1-bis (4-hydroxyphenyl) ethane and the like can be mentioned.

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

  As methacrylic acid esters, methyl methacrylate, ethyl methacrylate, n-, i- or t-butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate Etc.

  Examples of acrylic esters 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 only of structural units derived from (meth) acrylic monomers, or may contain other structural units.

In one preferred embodiment, the (meth) acrylic resin contains methyl methacrylate as a copolymer component, or contains 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 another copolymer component It is preferable that it is a copolymer in which is copolymerized.

As other copolymerization components other than the above-mentioned acrylic acid ester, for example, methyl 2- (hydroxymethyl) acrylate, methyl 2- (1-hydroxyethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate, 2- Hydroxyalkyl acrylic acid esters such as (hydroxymethyl) acrylic acid n-, i- or t-butyl;
Unsaturated acids such as methacrylic acid and acrylic acid;
Halogenated styrenes such as chlorostyrene and bromostyrene;
Substituted styrenes such as vinyl toluene and α-methylstyrene;
Unsaturated nitriles such as acrylonitrile and methacrylonitrile;
Unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride;
Unsaturated imides such as phenyl maleimide and cyclohexyl maleimide;
Etc. can be mentioned.
The other monofunctional monomers may be used alone or in combination of two or more.

A polyfunctional monomer may be used as the other copolymerization component.
As a polyfunctional monomer, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, nona ethylene glycol di (meth) Those obtained by esterifying both terminal hydroxyl groups of ethylene glycol or its oligomers such as acrylate and tetradecaethylene glycol di (meth) acrylate with (meth) acrylic acid;
Esterification of both terminal hydroxyl groups of propylene glycol or its oligomer with (meth) acrylic acid;
Hydroxyl groups of a dihydric alcohol such as neopentyl glycol di (meth) acrylate, hexanediol di (meth) acrylate, butanediol di (meth) acrylate esterified with (meth) acrylic acid;
Bisphenol A, an alkylene oxide adduct of bisphenol A, or both terminal hydroxyl groups of these halogen-substituted products are esterified with (meth) acrylic acid;
Those obtained by esterifying polyhydric alcohols such as trimethylolpropane and pentaerythritol with (meth) acrylic acid, and those obtained by ring-opening addition of epoxy group of glycidyl (meth) acrylate to these terminal hydroxyl groups;
Those obtained by ring-opening addition of epoxy group of glycidyl (meth) acrylate to succinic acid, adipic acid, terephthalic acid, phthalic acid, dibasic acids such as halogen substituted products thereof, or alkylene oxide adducts thereof;
Aryl (meth) acrylates; aromatic divinyl compounds such as divinyl benzene;
Etc.
Among them, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate and neopentyl glycol dimethacrylate are preferably used.

  The (meth) acrylic resin may be one modified by the reaction between functional groups possessed by the copolymer. Examples of the reaction include intramolecular demethanol condensation reaction of a methyl ester group of methyl (meth) acrylate and a hydroxyl group of methyl 2- (hydroxymethyl) acrylate, and a carboxyl group of (meth) acrylic acid The polymer intrachain dehydration condensation reaction with the hydroxyl group of methyl 2- (hydroxymethyl) acrylate and the like can be mentioned.

  The glass transition temperature of the (meth) acrylic resin is preferably 80 ° C. or more and 160 ° C. or less. The glass transition temperature is a polymerization ratio of a methacrylic acid ester monomer to an acrylic acid ester monomer, a carbon chain length of each ester group and a kind of functional group having them, and a polyfunctional single monomer for the whole monomer. It can be controlled by adjusting the polymerization ratio of the mer.

As a means for raising the glass transition temperature of (meth) acrylic resins, it is also effective to introduce a ring structure into the main chain of the polymer. 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 cyclic acid anhydride structures such as a glutaric anhydride structure and a succinic anhydride structure; cyclic imide structures such as a glutarimide structure and a succinic imide structure; and lactone ring structures 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 able to be increased.
Cyclic acid anhydride structure and cyclic imide structure are introduced by copolymerizing a monomer having a cyclic structure such as maleic anhydride and maleimide; cyclic acid anhydride structure is obtained by post-polymerization dehydration / demethanol condensation reaction Method of Introduction: It can be introduced by a method of reacting an amino compound to introduce a cyclic imide structure.
The resin (polymer) having a lactone ring structure is prepared by preparing a polymer having a hydroxyl group and an ester group in the polymer chain, and then heating the hydroxyl group and the ester group in the obtained polymer by heating. Accordingly, it can be obtained by a method of forming a lactone ring structure by cyclocondensation in the presence of a catalyst such as an organophosphorus compound.

The (meth) acrylic resin and the thermoplastic resin film formed therefrom may optionally contain an additive. Examples of the additive include lubricants, antiblocking agents, heat stabilizers, antioxidants, antistatic agents, light stabilizers, impact modifiers, surfactants and the like.
These additives can be used also when using other thermoplastic resins other than a (meth) acrylic-type resin as a thermoplastic resin which comprises a thermoplastic resin film.

  The (meth) acrylic resin may contain acrylic rubber particles, which are impact modifiers, from the viewpoint of film forming property to a film, impact resistance of a film, and the like. Acrylic rubber particles are particles containing an elastic polymer mainly composed of acrylic acid ester as an essential component, and one having a single layer structure substantially consisting only of this elastic polymer, or one elastic polymer. The thing of the multilayer structure made into a layer is mentioned.

As an example of the above-mentioned elastic polymer, there is mentioned a crosslinked elastic copolymer containing an alkyl acrylate as a main component and copolymerized with another vinyl monomer and a crosslinkable monomer copolymerizable therewith.
The alkyl acrylate which is the main component of the elastic polymer includes, for example, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate and the like, having an alkyl group having a carbon number of about 1 to 8 The alkyl acrylate having an alkyl group having 4 or more carbon atoms is preferably used.

  Examples of other vinyl monomers copolymerizable with the above alkyl acrylate include compounds having one polymerizable carbon-carbon double bond in the molecule, and more specifically methyl methacrylate And methacrylates; aromatic vinyl compounds such as styrene; and vinyl cyano compounds such as acrylonitrile.

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

  A laminate of a film made of a (meth) acrylic resin not containing 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 polarizer 30 You can also. In addition, a (meth) acrylic resin layer is formed on one side or both sides of a retardation expression layer made of a resin different from the (meth) acrylic resin, and the one exhibiting the retardation is bonded to the polarizer 30. The thermoplastic resin film can also be used.

  Each of the first thermoplastic resin film 10 and the second thermoplastic resin film 20 is at least one thermoplastic resin selected from the group consisting of a cellulose ester resin, a polyester resin, a (meth) acrylic resin and a cyclic polyolefin resin. It is preferably a film containing a resin, and more preferably a cellulose ester resin film, a polyester resin film, a (meth) acrylic resin film, or a cyclic polyolefin resin film.

The first thermoplastic resin film 10 and / or the second thermoplastic resin film 20 may contain an ultraviolet absorber. When the polarizing plate is applied to an image display device such as a liquid crystal display device, a thermoplastic resin film containing an ultraviolet light absorber is disposed on the viewing side of an image display device (for example, a liquid crystal cell). Deterioration can be suppressed.
Examples of UV absorbers include salicylic acid ester compounds, benzophenone compounds, benzotriazole compounds, cyanoacrylate compounds, and nickel complex compounds.

  The first thermoplastic resin film 10 and the second thermoplastic resin film 20 may be films composed of the same thermoplastic resin, or may be films composed of different thermoplastic resins. The first thermoplastic resin film 10 and the second thermoplastic resin film 20 may be the same or different in thickness, presence or absence of additives, types thereof, 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 antireflective layer, a light diffusion layer, an electrification layer on the outer surface (surface opposite to the polarizer 30). You may provide surface treatment layers (coating layer), such as a prevention layer, an antifouling layer, and a conductive layer.

  The thickness of each of the first thermoplastic resin film 10 and the second thermoplastic resin film 20 is generally 5 μm to 200 μm, preferably 10 μm to 120 μm, more preferably 10 μm to 85 μm, and still more preferably 15 μm to 65 μm. It is. The thickness of each 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. Reducing the thickness of the first thermoplastic resin film 10 and the second thermoplastic resin film 20 is advantageous for thinning the polarizing plate and hence the image display device.

The surface of the first thermoplastic resin film 10 and the second thermoplastic resin film 20 to which the curable composition is applied is a surface such as saponification treatment, plasma treatment, corona treatment, or primer treatment from the viewpoint of improving adhesion. A modification treatment may be performed, or a surface modification treatment may not be performed from the viewpoint of process simplification. The surface modification treatment may be performed on the bonding surface of the polarizer 30 instead of, or together with the bonding surface of the thermoplastic resin film.
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 perform a saponification treatment from the viewpoint of improving adhesion. As a saponification process, the method of immersing in the aqueous solution of an alkali like sodium hydroxide or potassium hydroxide is mentioned.

[5] Second Hardened Material Layer The curable composition forming the second hardened material layer 25 may be the above-mentioned curable composition (S), or another curable composition different therefrom. It 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 and the like of the polarizing plate.
In the case where 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. May be
Other curable compositions include known aqueous adhesives in which a curable adhesive component is dissolved or dispersed in water, and known active energy ray curable adhesives containing active energy ray curable compounds. Be

Examples of the water-based adhesive include water-based adhesives in which an adhesive component such as polyvinyl alcohol resin or urethane resin is dissolved or dispersed in water.
A water-based adhesive containing a polyvinyl alcohol-based resin is a curable component such as a polyvalent aldehyde, a melamine-based compound, a zirconia compound, a zinc compound, a glyoxal, a glyoxal derivative, a water-soluble epoxy resin, or a crosslinking agent in order to improve adhesion. Can be contained.
As a water-based adhesive containing a urethane resin, a water-based adhesive containing a polyester ionomer type urethane resin and a compound having a glycidyloxy group can be mentioned. A polyester-based ionomer-type urethane resin is a urethane resin having a polyester skeleton, into which a small amount of ionic component (hydrophilic component) is introduced.

  An active energy ray-curable adhesive is an adhesive that cures upon irradiation with active energy rays such as ultraviolet light, visible light, electron beams, and X-rays. In the case of using an active energy ray-curable adhesive, the second cured product layer 25 is a cured product layer of the adhesive.

  The active energy ray-curable adhesive can be an adhesive containing, as a curable component, an epoxy-based compound which is cured by cationic polymerization, and preferably, an ultraviolet-curable adhesive comprising such an epoxy-based compound as a curable component It is an agent. The epoxy compound means a compound having an average of one or more, preferably two or more epoxy groups in the molecule. The epoxy compounds may be used alone or in combination of two or more.

  As an epoxy compound, a hydrogenated epoxy compound obtained by reacting epichlorohydrin with an alicyclic polyol obtained by subjecting an aromatic ring of an aromatic polyol to a hydrogenation reaction (having an alicyclic ring Aliphatic epoxy compounds such as glycidyl ethers of polyols); aliphatic polyalcohols or polyglycidyl ethers of alkylene oxide adducts thereof; epoxy compounds having at least one epoxy group bonded to an alicyclic ring in the molecule A certain alicyclic epoxy type compound etc. are mentioned.

  The active energy ray-curable adhesive can contain, as a curable component, a (meth) acrylic compound which is radically polymerizable instead of or together with the above-mentioned epoxy compound. (Meth) acrylic compounds are (meth) acrylate monomers having one or more (meth) acryloyloxy groups in the molecule; obtained by reacting two or more functional group-containing compounds, and at least two in the molecule And (meth) acryloyloxy group-containing compounds such as (meth) acrylate oligomers having a (meth) acryloyloxy group of

When the active energy ray-curable adhesive contains an epoxy compound curable by cationic polymerization as a curable component, it preferably contains a photo cationic polymerization initiator. Examples of the cationic photopolymerization 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 adhesive contains a radical polymerizable component such as a (meth) acrylic compound, it is preferable to contain a photo radical polymerization initiator. Examples of photo radical polymerization initiators include acetophenone initiators, benzophenone initiators, benzoin ether initiators, thioxanthone initiators, xanthones, fluorenones, camphorquinones, benzaldehydes, anthraquinones and the like.

  The polarizing plate may include an adhesive layer instead of the second cured product layer 25. That is, the second thermoplastic resin film 20 may be bonded to the polarizer 30 via the pressure-sensitive adhesive layer. For the pressure-sensitive adhesive layer, the description of the pressure-sensitive adhesive layer described later is cited.

[6] Production of Polarizing Plate By laminating and bonding the first thermoplastic resin film 10 on one surface of the polarizer 30 via the first cured product layer 15, a polarizing plate having the configuration shown in FIG. 2 is obtained. By further laminating and adhering the second thermoplastic resin film 20 to the other surface of the polarizer 30 via the second cured product layer 25, a polarizing plate having the configuration shown in FIG. 3 can be obtained.
When manufacturing the polarizing plate which has both the 1st thermoplastic resin film 10 and the 2nd thermoplastic resin film 20, these films may carry out lamination adhesion on one side at a time stepwise, or laminate the film of both sides simultaneously It may be adhered.

As a method of adhering the polarizer 30 and the first thermoplastic resin film 10, the curable composition (S) is applied to either one or both of the polarizer 30 and the bonding surface of the first thermoplastic resin film 10 It coats, the other bonding side is laminated on this, for example, the method of pressing and bonding from the upper and lower sides using a bonding roll etc. is mentioned.
For coating of the curable composition (S), various coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater can be used, for example. In addition, while the polarizer 30 and the first thermoplastic resin film 10 are continuously supplied such that the bonding surfaces of the two are on the inside, the curable composition (S) may be cast between them. Good.

  After laminating the polarizer 30 and the first thermoplastic resin film 10, heat treatment is performed on the laminate including the polarizer 30, the first cured product layer 15, and the first thermoplastic resin film 10. Is preferred. The temperature of the heat treatment is, for example, 40 ° C. or more and 100 ° C. or less, preferably 50 ° C. or more and 90 ° C. or less. The heat treatment can remove the solvent contained in the curable composition layer. Moreover, the curing / crosslinking reaction of the curable composition can be advanced by the heat treatment.

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

When using an active energy ray-curable adhesive, after drying a curable composition layer as needed, an active energy ray is irradiated and a curable composition layer is hardened.
The light source used to irradiate the active energy ray may be any one capable of generating ultraviolet light, electron beam, X-ray 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 a light emission distribution at a wavelength of 400 nm or less are suitably used.

  The polarizing plate which does not have a 1st thermoplastic resin film on the 1st hardened | cured material layer 15 as shown in FIG. 1 applies the curable composition (S) on the surface of the polarizer 30, and the obtained lamination is obtained. The body can be produced, for example, by heat treatment at 80 ° C. for 300 seconds in a hot air dryer. Moreover, after manufacturing the laminated body which consists of separate film / curable composition (S) / polarizer 30, a separate film is peeled and the polarizing plate shown in FIG. 1 is manufactured also by heat-processing after that. Can.

The thickness of the first cured product layer 15 formed of 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, more preferably 10 nm or more and 5 μm or less, more preferably Is 20 nm or more and 1 μm or less. The adhesive layer formed from the above-mentioned known water-based adhesive can also have a similar thickness.
The thickness of the adhesive layer formed of the active energy ray-curable adhesive is, for example, 10 nm or more and 20 μm or less, preferably 100 nm or more and 10 μm or less, 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 different thicknesses.

[7] Other Constituent Elements of Polarizing Plate [7-1] Optical Functional Film The polarizing plate can be provided with other optical functional films other than the polarizer 30 for imparting a desired optical function, One preferred example is 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 be laminated separately from these films. In the latter case, the retardation film is formed of 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 pressure-sensitive adhesive layer or the adhesive layer. Can be laminated to the outer surface of

As a retardation film, a birefringent film composed of a stretched film of a light transmitting thermoplastic resin; a film in which a discotic liquid crystal or a nematic liquid crystal is oriented and fixed; the above liquid crystal layer is formed on a base film And the like.
The base film is usually a film made of a thermoplastic resin, and one example of the thermoplastic resin is a cellulose ester-based resin such as triacetyl cellulose.

  Examples of other optical functional films (optical members) that may be included in the polarizing plate include a light collector, a brightness enhancement film, a reflective layer (reflective film), a semi-transmissive reflective layer (semi-transmissive reflective film), a light diffusion layer (light Diffusion film etc. These are generally provided when the polarizing plate is a polarizing plate disposed on the back side (backlight side) of the liquid crystal cell.

  The light collecting plate is used for the purpose of light path control and the like, and may be a prism array sheet, a lens array sheet, a dot-attached sheet or the like.

  The brightness enhancement film is used for the purpose of improving the brightness in a liquid crystal display device to which a polarizing plate is applied. Specifically, a reflection type polarization separation sheet designed to have anisotropy in reflectance by laminating a plurality of thin film films having mutually different anisotropy of refractive index, an alignment film of cholesteric liquid crystal polymer and its alignment The circularly polarized light separation sheet etc. which supported the liquid crystal layer on the base film are mentioned.

  The reflective layer, the semi-transmissive reflective layer, and the light diffusion layer are provided to make the polarizing plate an optical member of a reflective type, a semi-transmissive type, or a diffusion type. The reflective polarizing plate is used in a liquid crystal display device of a type in which incident light from the viewing side is reflected and displayed, and a light source such as a backlight can be omitted, so that the liquid crystal display device can be easily thinned. A semi-transmissive polarizing plate is used as a reflective type in a bright place and in a liquid crystal display device of a type in which light from a backlight is displayed in a dark place. Further, the diffusion type polarizing plate is used for a liquid crystal display device in which light diffusibility is imparted to suppress display defects such as moiré. The reflective layer, the semitransparent reflective layer and the light diffusion layer can be formed by a known method.

[7-2] Pressure-Sensitive Adhesive Layer The polarizing plate according to the present invention can include a pressure-sensitive adhesive layer. As an adhesive layer, the adhesive layer for bonding a polarizing plate to image display elements, such as a liquid crystal cell, or another optical member is mentioned. The pressure-sensitive adhesive layer is the outer surface of the polarizer 30 in the polarizing plate having the configuration shown in FIGS. 1 and 2, and the first thermoplastic resin film 10 or the second thermoplastic resin film in the polarizing plate having the configuration shown in FIG. 20, the outer surface of the first cured product layer 15 or the second thermoplastic resin film 20 in the polarizing plate having the configuration shown in FIG. 4, or the first cured material layer 15 in the polarizing plate having the configuration shown in FIG. It can be laminated on the outer surface of the second cured product layer 25.

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

To form a pressure-sensitive adhesive layer on a polarizing plate, for example, a pressure-sensitive adhesive composition is dissolved or dispersed in an organic solvent such as toluene or ethyl acetate to prepare a pressure-sensitive adhesive solution, and this is directly coated on the target surface of the polarizing plate Using a method of forming a pressure-sensitive adhesive layer or a method of forming a pressure-sensitive adhesive layer in sheet form on a separate film subjected to release treatment and transferring it to a target surface of a polarizing plate. Can.
The thickness of the pressure-sensitive adhesive layer is determined according to the adhesive strength and the like, but a range of 1 μm to 50 μm is appropriate, and preferably 2 μm to 40 μm.

  The polarizing plate may include the above-described separate film. The separate film can be a film made of a polyethylene-based resin such as polyethylene, a polypropylene-based resin such as polypropylene, or a polyester-based resin such as polyethylene terephthalate. Among them, a stretched film of polyethylene terephthalate 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, etc. be able to.

[7-3] Protecting Film The polarizing plate according to the present invention has a surface (typically, the first thermoplastic resin film 10, the second thermoplastic resin film 20, the first cured product layer 15 and / or the second A protective film for protecting the surface of the cured product layer 25 can be included. The protective film is peeled off together with the pressure-sensitive adhesive layer it has, for example, after a polarizing plate is bonded to an image display element or another optical member.

The protective film is composed of, for example, a base film and a pressure-sensitive adhesive layer laminated thereon. The above description is cited for the pressure-sensitive adhesive layer.
The resin constituting the substrate film is, for example, a thermoplastic resin such as a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, a polyester resin such as polyethylene terephthalate or polyethylene naphthalate, and a polycarbonate resin. be able to. Preferably, polyester resins such as polyethylene terephthalate are used.

<Liquid crystal panel and liquid crystal display device>
The polarizing plate according to the present invention can be used in a liquid crystal panel and a liquid crystal display device. The liquid crystal panel includes a liquid crystal cell and polarizing plates disposed on both sides thereof. The liquid crystal display device includes a liquid crystal panel and a backlight.
The polarizing plate according to the present invention can be disposed on one side or both sides of the liquid crystal cell. A pressure-sensitive adhesive layer can be used to attach the polarizing plate to the liquid crystal cell.
An example of an optical laminate in which a polarizing plate is laminated on a liquid crystal cell via an adhesive layer is shown in FIG. The optical laminate shown in FIG. 6 is obtained by laminating the polarizing plate shown in FIG. 3 on one side of the liquid crystal cell 50 with the adhesive layer 40 interposed therebetween. The first thermoplastic resin film 10, the first A cured product layer 15, a polarizer 30, a second cured product layer 25, a second thermoplastic resin film 20, an adhesive layer 40, and a liquid crystal cell 50 are included in this order. For the pressure-sensitive adhesive layer 40, the above description of the pressure-sensitive adhesive layer is cited.
The liquid crystal cell may be of any type, for example, various liquid crystal cells such as an active matrix drive type liquid crystal cell represented by a thin film transistor type and a simple matrix drive type liquid crystal cell represented by a super twisted nematic type Thus, a liquid crystal panel and a liquid crystal display device can be formed. The polarizing plates provided on both sides of the liquid crystal cell may be the same or different.

Hereinafter, the present invention will be more specifically described by way of examples, but the present invention is not limited by these examples. In the examples,% and parts representing contents or amounts used are by mass unless otherwise specified.
In Table 1, an oxazoline group-containing polymer (A), a compound (B) having a carboxyl group, and a compound which promotes the reaction between the oxazoline group of the oxazoline group-containing polymer (A) and the carboxyl group of the compound (B) C) is abbreviated as (A), (B) and (C) respectively.

(Production Example: Production of Polarizer)
After immersing a 60 μm thick polyvinyl alcohol film (average degree of polymerization: about 2,400, degree of saponification: 99.9 mol% or more) in pure water at 30 ° C, the mass ratio of iodine / potassium iodide / water is It was immersed in an aqueous solution of 30 ° C., which is 0.02 / 2/100. Thereafter, it was immersed in an aqueous solution at 56.5 ° C. in which the mass ratio of potassium iodide / boric acid / water was 12/5/100. Subsequently, the resultant was washed with pure water at 8 ° C., and then dried at 65 ° C. to obtain a 23 μm-thick polarizer in which iodine was adsorbed and oriented to a polyvinyl alcohol film. The stretching was mainly performed in the steps of iodine dyeing and boric acid treatment, and the total stretching ratio was 5.5.

Examples 1 to 12 and Comparative Examples 1 to 5
(1) Preparation of Curable Composition The components shown in Table 1 were mixed together with pure water as a solvent in the amounts shown in Table 1 to prepare a curable composition (adhesive aqueous solution). The unit of the compounding quantity of each component shown in Table 1 is a mass part, and the compounding quantity of each component is the quantity in conversion of solid content. In each Example and Comparative Example, the total concentration of (A) and (B) in the obtained curable composition was 3.0% by mass.

(2) Preparation of Polarizing Plate One side of triacetylcellulose (TAC) film (trade name "KC4UAW" manufactured by Konica Minolta Opto, Inc., thickness: 40 μm) is subjected to a saponification treatment, and then the saponification treatment surface is applied. The curable composition prepared in the above (1) is coated using a bar coater, and one side of a zero retardation film (trade name “ZEONOR” manufactured by Nippon Zeon Co., Ltd.) made of a cyclic polyolefin resin having a thickness of 23 μm. The surface was treated with corona, and the curable composition prepared in the above (1) was applied to the corona-treated surface using a bar coater. A saponified TAC film is laminated on one side of the polarizer such that the curable composition layer is on the polarizer side, and a zero retardation film is laminated on the other side to achieve zero retardation film / curability A laminate having a layer structure of composition layer / polarizer / curable composition layer / TAC film was obtained. By subjecting this laminate to a heat treatment at 80 ° C. for 300 seconds with a hot air dryer, a polarizing plate having a layer configuration of zero retardation film / cured material layer / polarizer / cured material layer / TAC film is 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 bonded to a glass substrate via a (meth) acrylic adhesive on the zero retardation film side, and a measurement sample I got The layer configuration of the measurement sample is glass substrate / (meth) acrylic pressure-sensitive adhesive layer / zero retardation film / cured product layer / polarizer / cured product layer / TAC film. For the glass substrate, a non-alkali glass substrate (trade name "Eagle XG" manufactured by Corning Inc.) was used.
About the obtained measurement sample, MD transmittance and TD transmittance in the wavelength range of 380 to 780 nm are measured using a spectrophotometer with an integrating sphere (product name "V7100" manufactured by JASCO Corp.), each wavelength The degree of polarization was calculated. The calculated degree of polarization is corrected with a double vision (C light source) of JIS Z 8701: 1999 "Color display method-XYZ color system and X ₁₀ Y ₁₀ Z ₁₀ color system" before the endurance test. The visual sensitivity correction polarization degree Py was determined. The measurement sample was set to a spectrophotometer equipped with an integrating sphere so that the TAC film side of the polarizing plate was on the detector side and light was incident from the glass substrate side.

The degree of polarization is given by the following equation:
Degree of polarization (λ) = 100 × (Tp (λ) −Tc (λ)) / (Tp (λ) + Tc (λ))
Defined by
Tp (λ) is the transmittance (%) of the measurement sample measured in relation to the linear polarization of the incident wavelength λ (nm) and the parallel nicol.
Tc (λ) is the transmittance (%) of the measurement sample measured in the relationship between the linear polarization of the incident wavelength λ (nm) and the cross nicol.

Next, this measurement sample was placed in a high temperature and high humidity environment of 85 ° C. and relative humidity 85% RH for 500 hours, and then subjected to an endurance test placed in an environment of 23 ° C. and relative humidity 50% RH for 24 hours. After the endurance test, the degree of polarization correction Py was determined in the same manner as before the endurance test.
The optical durability of the polarizing plate was evaluated by calculating the absolute value (| ΔPy |) of the difference between the degree of polarization correction Py after the endurance test and the degree of polarization correction Py before the endurance test. The calculated values of | ΔPy | are shown in Table 1.
As the | ΔPy | is smaller, the optical durability is more excellent. In any of the examples and the comparative examples, the difference between the degree of polarization correction Py after the endurance test and the degree of polarization correction Py before the endurance test was a negative value.

The details of each component shown in Table 1 are as follows.
a1: trade name "Epocross WS-300" manufactured by Nippon Shokubai Co., Ltd. [2-solution of oxazoline group-containing acrylic polymer having side chain of 2-oxazoline group, solid content concentration: 10% by mass, oxazoline value (theoretical value) : 130 g solid / eq. The amount of oxazoline group (theoretical value): 7.7 mmol / g, solid, number average molecular weight: 4 × 10 ⁴ , weight average molecular weight: 12 × 10 ⁴ )]
b1: Citric acid b2: tartaric acid b3: malic acid b4: butane-1,2,3,4-tetracarboxylic acid b5: trade name "AP-10" manufactured by Nippon Shokubai Bi-Pobar KK [carboxyl group-modified polyvinyl alcohol , Average degree of polymerization: 1000, degree of saponification: 88 to 90 mol%]
c1: sulfuric acid c2: p-toluenesulfonic acid c3: acetic acid x 1: trade name “Gosefimer Z-200” (acetoacetyl group modified polyvinyl alcohol, average polymerization degree: 1100, degree of saponification manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 98.5 mol% or more]
y1: Glyoxal

  10 first thermoplastic resin film, 15 first cured product layer, 20 second thermoplastic resin film, 25 second cured product layer, 30 polarizer, 40 pressure sensitive adhesive layer, 50 liquid crystal cell.

Claims (13)

A polarizing plate including a polarizer and a first cured product layer in this order,
The first cured material layer is
An oxazoline group-containing polymer (A),
A compound (B) having a carboxyl group,
A compound (C) which promotes the reaction of the oxazoline group of the oxazoline group-containing polymer (A) with the carboxyl group of the compound (B),
A polarizing plate, which is a cured product layer of a curable composition containing   The content of the compound (B) in the curable composition is 0.01 parts by mass or more and 15 parts by mass or less in 100 parts by mass of the total amount of the oxazoline group-containing polymer (A) and the compound (B). Item 2. The polarizing plate according to item 1.   The content of the compound (C) in the curable composition is 10 parts by mass or more and 100 parts by mass or less based on 100 parts by mass of the total amount of the oxazoline group-containing polymer (A) and the compound (B). The polarizing plate as described in 1 or 2.   The polarizing plate according to any one of claims 1 to 3, wherein the compound (B) has two or more carboxyl groups in the molecule.   The polarizing plate of any one of Claims 1-4 whose compound (B) is 1000 or less molecular weight.   The polarizing plate of any one of Claims 1-5 which contains the said polarizer, the said 1st hardened | cured material layer, and a 1st thermoplastic resin film in this order.   The first thermoplastic resin film according to claim 6, wherein the first thermoplastic resin film comprises one or more thermoplastic resins selected from the group consisting of cellulose ester resins, polyester resins, (meth) acrylic resins and cyclic polyolefin resins. Polarizer.   The polarized light according to claim 6 or 7 which includes the 2nd thermoplastic resin film, the 2nd hardened material layer, the above-mentioned light polarizer, the 1st hardened material layer, and the 1st thermoplastic resin film in this order. Board.   The polarizing plate of any one of Claims 1-8 in which a polarizer contains polyvinyl alcohol-type resin. A curable composition for adhering a polarizer and a first thermoplastic resin film, comprising:
An oxazoline group-containing polymer (A),
A compound (B) having a carboxyl group,
A compound (C) which promotes the reaction of the oxazoline group of the oxazoline group-containing polymer (A) with the carboxyl group of the compound (B),
A curable composition comprising:   The curing according to claim 10, wherein the content of the compound (B) is 0.01 parts by mass or more and 15 parts by mass or less in 100 parts by mass of the total amount of the oxazoline group-containing polymer (A) and the compound (B). Sex composition.   The content of the compound (C) is 10 parts by mass or more and 100 parts by mass or less based on 100 parts by mass of the total amount of the oxazoline group-containing polymer (A) and the compound (B). Curable composition. An oxazoline group-containing polymer (A),
A compound (B) having a carboxyl group,
A compound (C) which promotes the reaction of the oxazoline group of the oxazoline group-containing polymer (A) with the carboxyl group of the compound (B),
A cured product layer obtained by curing a curable composition containing
The cured product layer whose content of a compound (C) is 10 mass parts or more and 100 mass parts or less with respect to 100 mass parts of total amounts of an oxazoline group containing polymer (A) and a compound (B).

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