TWI772500B - Polarizing plate - Google Patents

Abstract

The present invention provides a polarizing plate excellent in optical durability even under a high temperature and high humidity environment. The polarizing plate comprises a polarizer and a first cured material layer in this order, and the first cured material layer is a cured material layer of a curable composition, wherein the curable composition comprises an oxazoline group-containing polymer (A), a carboxyl group-containing compound (B), and a compound (C) which accelerates the reaction between the oxazoline group of oxazoline group-containing polymer (A) and the carboxyl group of compound (B).

Description

polarizer

The present invention relates to polarizing plates.

In recent years, liquid crystal display devices have been gradually developed in mobile device applications represented by smartphones and tablet terminals, and vehicle-mounted devices represented by navigation systems. In such a use, compared with the conventional indoor TV use, since there is a possibility of being exposed to a harsh environment, it is a problem to improve the durability of the device.

Durability is also required for optical films constituting liquid crystal display devices and the like. That is, an optical film incorporated in a liquid crystal display device or the like is placed in a high temperature or high temperature and high humidity environment, or in an environment in which high temperature and low temperature are repeated, but even in such an environment, an optical film is required. Features don't get worse.

An example of the above-mentioned optical film is a polarizer formed by laminating a thermoplastic resin film such as a protective film using an adhesive on one side or both sides of the polarizer [for example, Japanese Patent Laid-Open No. 2009-008860 (Patent Document 1)] .

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2009-008860

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

The present invention provides a polarizing plate, a curable composition, and a cured product layer shown below.

唑啉基的聚合物(A)、具有羧基之化合物(B)、以及促進含有

唑啉基之聚合物(A)的

唑啉基、與化合物(B)之羧基反應之化合物(C)。 [1] A polarizing plate comprising a polarizer and a first cured product layer in this order, wherein the first cured product layer is a cured product layer of a curable composition, and the curable composition contains:

An oxazoline group-containing polymer (A), a carboxyl group-containing compound (B), and an accelerator containing

oxazoline-based polymer (A)

An oxazoline group, and a compound (C) reacted with the carboxyl group of the compound (B).

唑啉基之聚合物(A)及化合物(B)之合計量100質量份中，前述硬化性組成物中之化合物(B)的含量為0.01質量份以上15質量份以下。 [2] The polarizing plate according to the item [1], wherein the polarizing plate contains

Content of the compound (B) in the said curable composition is 0.01 mass part or more and 15 mass parts or less in 100 mass parts of total amounts of an oxazoline group polymer (A) and a compound (B).

唑啉基之聚合物(A)及化合物(B)的合計量100質量份，前述硬化性組成物中之化合物(C)的含量為超過10質量份且100質量份以下。 [3] The polarizing plate according to the item [1] or [2], wherein relative to the

The total amount of the oxazoline-based polymer (A) and the compound (B) is 100 parts by mass, and the content of the compound (C) in the curable composition is more than 10 parts by mass and 100 parts by mass or less.

[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 molecular weight of the compound (B) is 1000 or less.

[6] The polarizing plate according to any one of [1] to [5], which includes the polarizer, the first cured product layer, and the first thermoplastic resin film in this order.

[7] The polarizing plate according to the item [6], wherein the first thermoplastic resin film is selected from the group consisting of cellulose ester-based resins, polyester-based resins, (meth)acrylic-based resins, and cyclic polyolefin-based resins One or more thermoplastic resins in the formed group.

[8] The polarizing plate according to the item [6] or [7], comprising a second thermoplastic resin film, a second cured product layer, the polarizer, the first cured product layer, and the first cured product layer in this order Thermoplastic resin film.

[9] The polarizing plate according to any one of [1] to [8], wherein the polarizing plate contains a polyvinyl alcohol-based resin.

唑啉基之聚合物(A)、具有羧基之化合物(B)、以及促進含有

唑啉基之聚合物(A)的

唑啉基、與化合物(B)之羧基反應的化合物(C)。 [10] A curable composition for bonding a polarizer to a first thermoplastic resin film, comprising:

An oxazoline group-containing polymer (A), a carboxyl group-containing compound (B), and an accelerator containing

oxazoline-based polymer (A)

An oxazoline group and a compound (C) reacted with the carboxyl group of the compound (B).

唑啉基的聚合物(A)及化合物(B)之合計量100質量份中，化合物(B)之含量為0.01質量份以上15質量份以下。 [11] The polarizing plate according to the item [10], wherein the polarizing plate contains

The content of the compound (B) is 0.01 part by mass or more and 15 parts by mass or less in 100 parts by mass of the total amount of the oxazoline-based polymer (A) and the compound (B).

唑啉基的聚合物(A)及化合物(B)之合計量100質量份， 化合物(C)之含量為超過10質量份且100質量份以下。 [12] The polarizing plate according to the item [10] or [11], wherein relative to the

The total amount of the oxazoline-based polymer (A) and the compound (B) is 100 parts by mass, and the content of the compound (C) is more than 10 parts by mass and 100 parts by mass or less.

唑啉基之聚合物(A)、具有羧基之化合物(B)、以及促進含有

唑啉基之聚合物(A)的

唑啉基、與化合物(B)之羧基反應的化合物(C)；且，相對於含有

唑啉基的聚合物(A)及化合物(B)之合計量100質量份，化合物(C)之含量為超過10質量份且100質量份以下。 [13] A cured product layer obtained by curing a curable composition, the curable composition containing:

An oxazoline group-containing polymer (A), a carboxyl group-containing compound (B), and an accelerator containing

oxazoline-based polymer (A)

oxazoline, compound (C) reacted with the carboxyl group of compound (B);

The total amount of the oxazoline-based polymer (A) and the compound (B) is 100 parts by mass, and the content of the compound (C) is more than 10 parts by mass and 100 parts by mass or less.

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

10‧‧‧First thermoplastic resin film

15‧‧‧First hardened layer

20‧‧‧Second thermoplastic resin film

25‧‧‧Second hardened layer

30‧‧‧Polarizer

40‧‧‧Adhesive layer

50‧‧‧LCD unit

FIG. 1 is a schematic cross-sectional view showing an example of the layer structure of the polarizing plate of the present invention.

FIG. 2 is a schematic cross-sectional view showing another example of the layer structure of the polarizing plate of the present invention.

FIG. 3 is a schematic cross-sectional view showing another example of the layer structure of the polarizing plate of the present invention.

FIG. 4 is a schematic cross-sectional view showing another example of the layer structure of the polarizing plate of the present invention.

Fig. 5 is a schematic cross-sectional view showing another example of the layer structure of the polarizing plate of the present invention.

Fig. 6 is a schematic cross-sectional view showing another example of the optical layered product including the polarizing plate of the present invention.

<Polarizer>

唑啉基的聚合物(A)、具有羧基之化合物(B)〔以下亦稱為「化合物(B)」〕、及促進含有

唑啉基的聚合物(A)之

唑啉基與化合物(B)的羧基反應的化合物(C)〔以下亦稱為「化合物(C)」〕。 The polarizing plate of the present invention includes a polarizer and a first cured material layer in this order. The first cured product layer is a cured product layer of a curable composition containing:

An oxazoline group-containing polymer (A), a compound (B) having a carboxyl group (hereinafter also referred to as "compound (B)"], and the

Of the oxazoline-based polymers (A)

The compound (C) in which the oxazoline group reacts with the carboxyl group of the compound (B) [hereinafter also referred to as "compound (C)"].

The polarizing plate of 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 (eg, the degree of polarization) of the polarizing plate are not easily degraded even when placed in a high-temperature and high-humidity environment.

[1] Composition of polarizing plate

Examples of the layer structure of the polarizing plate of the present invention are shown in FIGS. 1 to 4 . The polarizing plate shown in FIG. 1 includes a polarizing plate 30 and a first cured material layer 15 laminated on one surface thereof. The first hardened material layer 15 coats the surface of the polarizer 30 and can function as a protective outer coating.

The polarizer 30 and the first hardened material layer 15 are preferably 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 on one surface with the first cured product layer 15 interposed therebetween. The first cured product layer 15 can function as an adhesive layer for bonding the polarizer 30 and the first thermoplastic resin film 10 to each other.

The first cured product layer 15 and the first thermoplastic resin film 10 are preferably in direct contact with each other.

The polarizer 30 and the first hardened material layer 15 are preferably 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 on one side with a first cured product layer 15 interposed therebetween, and a second cured film 30 on the other side of the polarizer 30 . The second thermoplastic resin film 20 to be laminated and bonded together with the object layer 25 . That is, the polarizing plate of the present invention may include 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. The first cured product layer 15 and the second cured product layer 25 can be used as an adhesive layer for bonding the polarizer 30 and the first thermoplastic resin film 10, and an adhesive for bonding the polarizer 30 and the second thermoplastic resin film 20, respectively. Floor.

The first cured product layer 15 and the first thermoplastic resin film 10 are preferably in direct contact with each other.

The polarizer 30 and the first hardened material layer 15 are preferably in direct contact with each other.

The second cured product layer 25 and the second thermoplastic resin film 20 are preferably in direct contact with each other.

The polarizer 30 and the second cured material layer 25 are preferably in direct contact with each other.

The polarizer shown in FIG. 4 includes a polarizer 30 , a first cured product layer 15 laminated on one side of the polarizer 30 , and a second thermoplastic layer laminated on the other side of the polarizer 30 with the second cured product layer 25 interposed therebetween. Resin film 20 . The first hardened material layer 15 can be used as a protective outer coating by covering 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 together.

The polarizer 30 and the first hardened material layer 15 are preferably in direct contact with each other.

The second cured product layer 25 and the second thermoplastic resin film 20 are preferably in direct contact with each other.

The polarizer 30 and the second cured material layer 25 are preferably in direct contact with each other.

The polarizing plate shown in FIG. 5 includes a polarizing plate 30 , a first cured product layer 15 laminated on one surface thereof, and a second cured product layer 25 laminated on the other surface of the polarizing plate 30 . The first hardened material layer 15 and the second hardened material layer 25 can be used as protective outer coatings for covering the surface of the polarizer 30 .

The polarizer 30 and the first hardened material layer 15 are preferably in direct contact with each other.

The polarizer 30 and the second cured material layer 25 are preferably in direct contact with each other.

The polarizing plate system of the present invention may include other layers (or films) other than those described above. Other layers include, for example, an adhesive layer laminated on the outer surfaces 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 polarizer 30; A release film (also referred to as a "release film") on the outer surface of the adhesive layer; laminated on the first thermoplastic resin film 10, the second thermoplastic resin film 20, the first cured product layer 15, and the second cured product layer 25 And/or the protective film on the outer surface of the polarizer 30 (also referred to as "surface protective film"); 25 and/or the outer surface of the polarizer 30 is an optically functional film (or layer) or the like laminated with an adhesive layer or an adhesive layer interposed therebetween.

[2] The first hardened material layer

唑啉基的聚合物(A)、化合物(B)及化合物(C)。 The first cured product layer 15 is a cured product layer of a curable composition (S) containing:

An oxazoline-based polymer (A), a compound (B), and a compound (C).

唑啉基之聚合物(A) [2-1] Contains

oxazoline-based polymer (A)

唑啉基的聚合物(A)係在分子內具有

唑啉基之聚合物，以在側鏈具有

唑啉基的聚合物為較佳。 contain

The oxazoline-based polymer (A) has in the molecule

An oxazoline-based polymer with a side chain

An oxazoline-based polymer is preferred.

唑啉基的聚合物(A)之骨架結構無特別限制，但例如可為由選自(甲基)丙烯酸骨架、苯乙烯骨架、烯烴骨架、酯骨架、碳酸酯骨架等之1種以上的骨架所構成。 contain

The skeleton structure of the oxazoline-based polymer (A) is not particularly limited, but may be, for example, one or more skeletons selected from the group consisting of (meth)acrylic skeleton, styrene skeleton, olefin skeleton, ester skeleton, carbonate skeleton, and the like constituted.

In the present specification, "(meth)acrylic acid" means at least one kind selected from the group consisting of acrylic acid and methacrylic acid. The same applies to the descriptions of "(meth)acryloyl" and "(meth)acrylate".

唑啉基的聚合物(A)可在上述骨架結構之側鏈具有

唑啉基。 contain

The oxazoline-based polymer (A) may have in the side chain of the above-mentioned skeleton structure

oxazoline.

唑啉基的聚合物(A)之較佳的一例係含有

唑啉基的(甲基)丙烯酸系聚合物，該聚合物係包含由(甲基)丙烯酸骨架所構成的骨架結構作為構成單元之主成分，在側鏈導入有含有

唑啉基的構成單元(源自含有

唑啉基之單體的構成單元)作為共聚合成分。 contain

A preferable example of the oxazoline-based polymer (A) contains

An oxazoline-based (meth)acrylic polymer containing a skeleton structure composed of a (meth)acrylic skeleton as a main component of a structural unit, and a side chain containing

The structural unit of oxazoline group (derived from containing

The constituent unit of the monomer of the oxazoline group) as a copolymerization component.

唑啉基的聚合物(A)除了是將含有

唑啉基的單體共聚合而成者之外，亦可為藉由使聚合物之側鏈官能基改性而含有

唑啉基者。 contain

The oxazoline-based polymer (A) will contain in addition to

In addition to the copolymerization of oxazoline-based monomers, it can also be contained by modifying the side chain functional groups of the polymer.

oxazoline base.

唑啉基可舉例如2-

唑啉基、3-

唑啉基、4-

唑啉基等。

唑啉基較佳係2-

唑啉基等。

Examples of the oxazoline group include 2-

oxazolinyl, 3-

oxazolinyl, 4-

oxazolinyl etc.

The preferred oxazoline group is 2-

oxazolinyl etc.

唑啉基之單體可列舉2-異丙烯基-2-

唑啉、乙烯基-2-

唑啉等。 the above contains

As the monomer of oxazoline group, 2-isopropenyl-2-

oxazoline, vinyl-2-

oxazoline etc.

唑啉基的聚合物(A)之重量平均分子量較佳係5000以上，更佳係10000以上。從提升偏光板之光學耐久性、及提升偏光片30與第1硬化物層15之間的密著性或偏光片30與第1熱塑性樹脂膜10之間的接著性之觀點而言，重量平均分子量在上述範圍變得有利。含有

唑啉基的聚合物(A)之重量平均分子量通常為1000000(百萬)以下。 contain

The weight average molecular weight of the oxazoline-based polymer (A) is preferably 5,000 or more, more preferably 10,000 or more. From the viewpoint of enhancing the optical durability of the polarizing plate, and enhancing the adhesion between the polarizing plate 30 and the first cured product layer 15 or the adhesion between the polarizing plate 30 and the first thermoplastic resin film 10, the weight average The molecular weight becomes favorable in the above-mentioned range. contain

The weight average molecular weight of the oxazoline-based polymer (A) is usually 1,000,000 (million) or less.

唑啉基的聚合物(A)之重量平均分子量可利用凝膠滲透色層分析法(GPC)所得之標準聚苯乙烯換算值而測定。 contain

The weight-average molecular weight of the oxazoline-based polymer (A) can be measured by a standard polystyrene conversion value obtained by gel permeation chromatography (GPC).

唑啉基的聚合物(A)之

唑啉基量(每1g含有

唑啉基的聚合物(A)之固形份之

唑啉基的莫耳數)較佳係0.4mmol/g‧固體以上。

唑啉基量小於上述範圍時，偏光板之光學耐久性有降低之虞。從如此之觀點而言，含有

唑啉基的聚合物之

唑啉基量更佳係3mmol/g‧固體以上，更佳係5mmol/g‧固體以上9mmol/g‧固體以下。

唑啉基量之上限並無特別限制，但通常為50mmol/g‧固體以下。 contain

Of the oxazoline-based polymers (A)

Amount of oxazoline group (per 1g contains

of the solid content of the oxazoline-based polymer (A)

The molar number of the oxazoline group) is preferably 0.4 mmol/g·solid or more.

When the amount of oxazoline groups is less than the above range, the optical durability of the polarizing plate may be reduced. From this point of view, it contains

of oxazoline-based polymers

The amount of the oxazoline group is more preferably 3 mmol/g·solid or more, and more preferably 5 mmol/g·solid or more and 9 mmol/g·solid or less.

The upper limit of the amount of oxazoline groups is not particularly limited, but is usually 50 mmol/g·solid or less.

唑啉基的聚合物(A)較佳係水系，亦即水溶性之聚合物、或水分散性之聚合物。從第1硬化物層15之光學特性的觀點而言，含有

唑啉基的聚合物(A)較佳係水溶性之聚合物。 contain

The oxazoline-based polymer (A) is preferably a water-based polymer, 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 , containing

The oxazoline-based polymer (A) is preferably a water-soluble polymer.

唑啉基的聚合物(A)可使用市售品。具體而言，可舉例如日本觸媒股份有限公司製之EPOCROS WS-300、EPOCROS WS-500、EPOCROS WS-700(任一者皆為商品名)等含有

唑啉基的丙烯酸聚合物；日本觸媒股份有限公司製EPOCROS K-1000系列、EPOCROS K-2000系列、EPOCROS RPS系列(任一者皆為商品名)等含有

唑啉基的丙烯酸/苯乙烯聚合物。 contain

A commercial item can be used for the oxazoline-based polymer (A). Specifically, for example, EPOCROS WS-300, EPOCROS WS-500, and EPOCROS WS-700 (all of them are trade names) manufactured by Nippon Shokubai Co., Ltd. may contain

Acrylic polymer of oxazoline group; EPOCROS K-1000 series, EPOCROS K-2000 series, EPOCROS RPS series (any of them are trade names) manufactured by Nippon Shokubai Co., Ltd. contains

An oxazoline based acrylic/styrene polymer.

唑啉基的聚合物(A)可併用2種以上而使用。 contain

The oxazoline-based polymer (A) may be used in combination of two or more.

唑啉基的聚合物(A)較佳為EPOCROSWS-300、EPOCROSWS-500、EPOCROSWS-700等含有

唑啉基的丙烯酸聚合物。 From the optical durability and optical properties of the polarizing plate, the adhesion between the polarizing plate 30 and the first cured product layer 15, the adhesion between the polarizing plate 30 and the first thermoplastic resin film 10, and the first cured product layer 15 From the viewpoint of water resistance, contains

The oxazoline-based polymer (A) preferably contains EPOCROSWS-300, EPOCROSWS-500, EPOCROSWS-700, etc.

An oxazoline-based acrylic polymer.

唑啉基的聚合物(A)之含量較佳係60質量%以上95質量%以下，更佳係65質量%以上90質量%以下，再更佳係70質量%以上85質量%以下。偏光板之光學耐久性、及偏光片30與第1硬化物層15之間的密著性或偏光片30與第1熱塑性樹脂膜10之間的接著性之觀點而言，使含有

唑啉基的聚合物(A)之含量為上述之範圍內為較佳。 When the solid content concentration of the curable composition (S) is set to 100% by mass, it contains

The content of the oxazoline-based polymer (A) is preferably 60 mass % or more and 95 mass % or less, more preferably 65 mass % or more and 90 mass % or less, still more preferably 70 mass % or more and 85 mass % or less. From the viewpoint of the optical durability of the polarizing plate, the adhesion between the polarizing plate 30 and the first cured product layer 15 , or the adhesion between the polarizing plate 30 and the first thermoplastic resin film 10 , the

The content of the oxazoline-based polymer (A) is preferably within the above-mentioned range.

The solid content concentration means the total concentration of components other than the solvent contained in the curable composition (S).

[2-2] Compound (B)

唑啉基的聚合物(A)之

唑啉基反應之羧基的化合物。在此所謂之羧基亦包含羧基之衍生物。 The compound (B) having a carboxyl group has a

Of the oxazoline-based polymers (A)

The compound of the carboxyl group of the oxazoline reaction. The carboxyl group referred to herein also includes derivatives of the carboxyl group.

Carboxyl group derivatives include carboxylate anion groups. Examples of cations that serve as counter ions to the carboxylate anion group include metal ions such as lithium ions, sodium ions, and potassium ions; and organic cations such as ammonium ions, perium ions, and phosphonium ions.

The curable composition (S) may contain one compound (B) or two or more compounds (B).

Among them, from improving the optical durability of the polarizing plate, the adhesion between the polarizing plate 30 and the first cured product layer 15, the adhesion between the polarizing plate 30 and the first thermoplastic resin film 10, and the first cured product layer From the viewpoint of the water resistance of 15, the compound (B) 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. The 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, maleic acid, fumaric acid, itaconic acid, hexadienedioic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2 ,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 2,5-pyridinedicarboxylic acid, 3,5-pyridinedicarboxylic acid, diphenyl Sulfodicarboxylic acid, diphenylmethanedicarboxylic acid, oxalacetic acid, methyl fumaric acid, 2,6-pyridinedicarboxylic acid, etc.

Another example of the polyfunctional carboxylic acid compound is a tricarboxylic acid compound. Tricarboxylic acid compounds include: citric acid, aconitic acid, propane-1,2,3-tricarboxylic acid, trimellitic acid, 1,3,5-benzenetricarboxylic acid, 1,2,3-benzenetricarboxylic acid, Biphenyl-3,4',5-tricarboxylic acid, 1,3,5-cyclohexanetricarboxylic acid, etc.

Yet another example of a polyfunctional carboxylic acid compound is a tetracarboxylic acid compound. The tetracarboxylic acid compounds include: pyromellitic acid, diphenylsulfotetracarboxylic acid, biphenyltetracarboxylic acid, diphenylketonetetracarboxylic acid, naphthalenetetracarboxylic acid, thiophenetetracarboxylic acid, butanetetracarboxylic acid , 1,2,4,5-4 (4-carboxyphenyl)benzene, etc.

Among the polyfunctional carboxylic acid compounds exemplified above, at least one carboxyl group may be a derivative thereof.

The compound (B) may have other functional groups than the carboxyl group. An example of other functional groups is a hydroxyl 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 such a polymer is a carboxyl group-modified polymer. An example of the carboxyl group-modified polymer is a carboxyl group-modified polyvinyl alcohol-based polymer.

The carboxyl group-modified polyvinyl alcohol-based polymer is a polyvinyl alcohol-based polymer modified by introducing a carboxyl group or a derivative thereof into a side chain.

Examples of the carboxyl group derivatives include carboxylate anion groups. Examples of the cations that become the counter ions of the carboxylate anion group are as described above. An example of a preferred cation is sodium ion.

The polyvinyl alcohol-based polymer constituting the main chain of the carboxyl-modified polyvinyl alcohol-based polymer may be a vinyl alcohol homopolymer (completely saponified) obtained by saponifying polyvinyl acetate, which is a homopolymer of vinyl acetate. Polyvinyl alcohol or partially saponified polyvinyl alcohol) can also be a polyvinyl alcohol-based copolymer obtained by saponifying a copolymer of vinyl acetate and other monomers that can be copolymerized with it.

Examples of other monomers that can be copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth)acrylic acid amides having an ammonium group.

The degree of saponification of the carboxyl-modified polyvinyl alcohol-based polymer is usually 80 mol% or more and 100 mol% or less, preferably 85 mol% or more (eg, 88 mol% or more).

The degree of saponification of the carboxyl group-modified polyvinyl alcohol-based polymer can be measured according to JIS K 6726:1994.

The degree of modification (modification amount) due to the carboxyl group (or its derivative) of the carboxyl group-modified polyvinyl alcohol-based polymer is usually 0.1 mol % or more. From improving the optical durability of the polarizer, the adhesion between the polarizer 30 and the first cured product layer 15 , the adhesion between the polarizer 30 and the first thermoplastic resin film 10 , and the adhesion between the first cured product layer 15 . From the viewpoint of water resistance, the modification degree of the carboxyl group-modified polyvinyl alcohol-based polymer is preferably 0.5 mol % or more and 40 mol % or less, and 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-based polymer is usually 100 or more and 3000 or less.

The average degree of polymerization of the carboxyl group-modified polyvinyl alcohol-based polymer can be measured according to JIS K 6726:1994.

In a preferred embodiment, the molecular weight of the compound (B) is 1000 or less. The molecular weight is the molecular weight calculated from the chemical structural formula, but when the compound (B) is a polymer, it may be the number average molecular weight in terms of standard polystyrene measured by gel permeation chromatography (GPC).

The use of the compound (B) having a molecular weight of 1000 or less is advantageous because the optical durability of the polarizing plate can be improved. 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.

Further, from the optical durability of the polarizing plate, the adhesion between the polarizing plate 30 and the first cured product layer 15 , the adhesion between the polarizing plate 30 and the first thermoplastic resin film 10 , and the first cured product layer 15 From the viewpoint of water resistance, the molecular weight of the compound (B) is preferably 90 or more, more preferably 100 or more.

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

唑啉基的聚合物(A)及化合物(B)之合計量100質量份中，硬化性組成物(S)中之化合物(B)的含量較佳係0.01質量份以上15質量份以下，更佳係0.1質量份以上12質量份以下，再更佳係0.3質量份以上未達10質量份。 From the viewpoint of improving the optical durability of the polarizing plate, in the

The content of the compound (B) in the curable composition (S) is preferably not less than 0.01 parts by mass and not more than 15 parts by mass in 100 parts by mass of the total amount of the oxazoline-based polymer (A) and the compound (B), and more It is preferably 0.1 parts by mass or more and 12 parts by mass or less, and more preferably 0.3 parts by mass or more and less than 10 parts by mass.

When the content of the compound (B) is too small, it is difficult to obtain good optical durability of the polarizing plate.

In addition, when the content of the compound (B) is too large, the optical durability of the polarizer, 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 At least one of the properties and the water resistance of the first cured product layer 15 tends to decrease easily.

[2-3] Compound (C)

唑啉基的聚合物(A)之

唑啉基、與化合物(B)之羧基反應的化合物。在此所謂之促進係亦包含使該反應開始的情形。 Compound (C) promotes containing

Of the oxazoline-based polymers (A)

An oxazoline group, a compound reacted with the carboxyl group of the compound (B). The term "promoting system" as used herein also includes a situation in which the reaction is initiated.

唑啉基的聚合物(A)之

唑啉基與化合物(B)之羧基反應之觸媒的化合物。 Preferable examples of the compound (C) include acid compounds. Acid compounds can act to make containing

Of the oxazoline-based polymers (A)

A compound that is a catalyst for the reaction between an oxazoline group and 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, and phenylphosphoric acid. , sulfanilic acid, phenylphosphonic acid, acetic acid, propionic acid and other organic acids.

The curable composition (S) may contain one compound (C), or may contain two or more compounds (C).

The compound (C) can be formulated into the curable composition (S) as a solution (for example, an aqueous solution) containing the compound (C).

Among them, from the viewpoint of improving the optical durability of the polarizing plate, the adhesion between the polarizing plate 30 and the first cured product layer 15 , or the adhesion between the polarizing plate 30 and the first thermoplastic resin film 10 , the compound (C) is preferably a strong acid, and examples of such acid compounds include sulfuric acid, hydrogen chloride (hydrochloric acid), nitric acid, p-toluenesulfonic acid, and the like.

When the above-mentioned strong acid is used as the compound (C), in particular, the adhesion between the polarizer 30 and the first cured product layer 15 or the adhesion between the polarizer 30 and the first thermoplastic resin film 10 can be easily improved. Subsequent tendencies.

唑啉基的聚合物(A)及化合物(B)之合計量100質量份，硬化性組成物(S)中之化合物(C)的含量通常為6質量份以上150質量份以下，從提高偏光板之光學耐久性、及偏光片30與第1硬化物層15之間之密著性或偏光片30與第1熱塑性樹脂膜10之間之接著性的觀點而言，較佳係10質量份以上100質量份以下，更佳係超過10質量份100質量份以下，再更佳係15質量份以上100質量份以下。 relative to containing

The total amount of the oxazoline-based polymer (A) and the compound (B) is 100 parts by mass, and the content of the compound (C) in the curable composition (S) is usually 6 parts by mass to 150 parts by mass. From the viewpoint of the optical durability of the plate, the adhesion between the polarizer 30 and the first cured product layer 15 , or the adhesiveness between the polarizer 30 and the first thermoplastic resin film 10 , it is preferably 10 parts by mass More than 100 parts by mass or less, more preferably more than 10 parts by mass and less than 100 parts by mass, still more preferably more than 15 parts by mass and less than 100 parts by mass.

唑啉基的聚合物(A)及化合物(B)之合計量100質量份，化合物(C)之含量為80質量份以下。 In a preferred embodiment, from the viewpoint of improving the optical durability of the polarizing plate, the

The total amount of the oxazoline-based polymer (A) and the compound (B) is 100 parts by mass, and the content of the compound (C) is 80 parts by mass or less.

When the content of the compound (C) is too small, it is difficult to obtain good optical durability of the polarizing plate.

Moreover, when the content of the compound (C) is too small, the adhesiveness between the polarizer 30 and the first cured product layer 15 or the adhesiveness between the polarizer 30 and the first thermoplastic resin film 10 tends to decrease easily.

When the content of the compound (C) is too large, the optical durability of the polarizing plate, the adhesion between the polarizing plate 30 and the first cured product layer 15, the adhesion between the polarizing plate 30 and the first thermoplastic resin film 10, And at least any one of the water resistance of the 1st hardened material layer 15 tends to fall easily.

[2-4] Other ingredients

唑啉基的聚合物(A)、化合物(B)及化合物(C)以外之其他成分。 The curable composition (S) may contain

Components other than the oxazoline-based polymer (A), compound (B), and compound (C).

Other components include polyaldehydes, melamine-based compounds, zirconia compounds, zinc compounds, aziridine compounds, glyoxal, glyoxal derivatives, water-soluble epoxy resins, and other curable components or crosslinking agents; carboxyl groups Modified polyvinyl alcohol polymers other than modified polyvinyl alcohol polymers; additives for coupling agents, tackifiers, antioxidants, ultraviolet absorbers, heat stabilizers, hydrolysis inhibitors, etc.

The curable composition (S) may contain one kind or two or more kinds of other components.

The curable composition (S) preferably contains a solvent. Examples of the solvent include water, organic solvents, or a mixture of these. 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 mass % or more of the total solvent.

The solid content concentration of the curable composition (S) is usually 0.5 mass % or more and 20 mass % or less, preferably 1 mass % or more and 15 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 dispersion (for example, an emulsion) in which the formulation components are dissolved in a solvent containing water, or in which the formulation components are dispersed in a solvent containing water. Moreover, when the curable composition (S) is used for forming the overcoat layer, the curable composition (S) is preferably a solution obtained by dissolving the formulation components in a solvent containing water, or dispersed in a solvent containing water Dispersions (eg emulsions) with formulated ingredients.

The viscosity of the curable composition (S) at 25°C is preferably 50mPa·sec or less, more preferably 1mPa·sec or more and 30mPa·sec or less, and even more preferably 2mPa·sec or more and 20mPa·sec or less. If the viscosity at 25°C exceeds 50 mPa·sec, it becomes difficult to apply uniformly, and there is a possibility of uneven application, and there is a possibility that defects such as pipe plugging may occur.

The viscosity at 25°C of the curable composition (S) can be measured with an E-type viscometer.

[3] Polarizer

The polarizer 30 is a film having a function of selectively transmitting linearly polarized light in a certain direction from natural light.

The polarizer 30 includes a polarizer containing a polyvinyl alcohol-based resin, and more specifically, a polarizer composed of a polyvinyl alcohol-based resin film.

Examples of polarizers made of polyvinyl alcohol-based resin films include: iodine-based polarizers obtained by adsorbing/aligning iodine as a dichroic dye to a polyvinyl alcohol-based resin film, and iodine-based polarizers as dichroic dyes A dye-based polarizer made of chromatic dyes adsorbed/aligned on a polyvinyl alcohol-based resin film.

In addition, the polarizer 30 may also be a coating-type polarizer obtained by coating a base film with a dichroic dye in a lyotropic liquid crystal state, and aligning/immobilizing it.

The above polarizers selectively transmit linearly polarized light in one direction from natural light and absorb linearly polarized light in the other direction, so they are called absorbing polarizers.

The polarizer 30 is not limited to an absorbing polarizer, but can also be a reflective polarizer that selectively transmits linearly polarized light in one direction from natural light and reflects linearly polarized light in another direction, or a reflective polarizer that transmits linearly polarized light in another direction. As the scattering type polarizer that scatters linearly polarized light, an absorption type polarizer is preferable in terms of excellent visibility.

Among them, a polyvinyl alcohol-based polarizer composed of a polyvinyl alcohol-based resin film is more preferred, and a polyvinyl alcohol-based resin film is more preferably formed by adsorbing/aligning dichroic dyes such as iodine or dichroic dyes to the polyvinyl alcohol-based resin film The polyvinyl alcohol-based polarizer is particularly preferably a polyvinyl alcohol-based polarizer obtained by adsorbing/aligning iodine to a polyvinyl alcohol-based resin film.

As the polyvinyl alcohol-based resin constituting the polyvinyl alcohol-based polarizer, a saponified polyvinyl acetate-based resin can be used. The polyvinyl acetate-based resin includes, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, copolymers of other monomers that can be copolymerized with vinyl acetate, and the like. Examples of other monomer systems that can be copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth)acrylic acid amides 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 can be modified, for example, polyvinyl acetal or polyvinyl acetal modified with aldehydes can also be used. The average degree of polymerization of the polyvinyl alcohol-based resin is usually 1,000 or more and 10,000 or less, preferably 1,500 or more and 5,000 or less.

The average degree of polymerization of the polyvinyl alcohol-based resin can be determined according to JIS K 6726:1994.

A film formed from such a polyvinyl alcohol-based resin can be used as a base film of the polarizer 30 made of a polyvinyl alcohol-based resin film. The method of forming a polyvinyl alcohol-based resin into a film is not particularly limited, and a known method can be employed. The thickness of the polyvinyl alcohol-based embryonic membrane is, for example, 150 μm or less, preferably 100 μm or less (for example, 50 μm or less), and 5 μm or more.

The polarizer 30 composed of the polyvinyl alcohol-based resin film can be manufactured by a method including the following steps: a step of uniaxially extending the polyvinyl alcohol-based resin film; The steps of dyeing and adsorbing dichroic pigments; the step of treating the polyvinyl alcohol-based resin film with the dichroic pigments adsorbed with boric acid aqueous solution (crosslinking treatment); and the step of washing with boric acid aqueous solution after treatment.

The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before the dyeing of the dichroic dye, simultaneously with the dyeing, or after the dyeing. When uniaxial extension is performed after dyeing, the uniaxial extension may be performed before or during boric acid treatment. In addition, uniaxial stretching may be performed in these plural stages.

In the case of uniaxial stretching, uniaxial stretching can be performed between rolls with different peripheral speeds, or uniaxial stretching can be performed using heated rolls. Further, the uniaxial stretching may be dry stretching in which the stretching is carried out in the atmosphere, or wet stretching in which the polyvinyl alcohol-based resin film is stretched in a swollen state using a solvent such as water. The stretching ratio is usually 3 times or more and 8 times or less.

As a method of dyeing a polyvinyl alcohol-based resin film with a dichroic dye, for example, the method of immersing the film in an aqueous solution containing a dichroic dye can be mentioned. As a dichroic dye, iodine and a dichroic organic dye can be used. In addition, the polyvinyl alcohol-based resin film is preferably subjected to water immersion treatment before dyeing treatment.

As a dyeing treatment method with iodine, for example, a method of immersing a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide is exemplified. The content of iodine in the aqueous solution may be not less than 0.01 part by mass and not more than 1 part by mass per 100 parts by mass of water. The content of potassium iodide may be 0.5 parts by mass to 20 parts by mass per 100 parts by mass of water. In addition, the temperature of the aqueous solution may be 20°C or higher and 40°C or lower.

On the other hand, the method of immersing a polyvinyl alcohol-type resin film etc. in the aqueous solution containing a dichroic organic dye, etc. are mentioned, for example as the dyeing process method using a dichroic organic dye. Aqueous solutions containing dichroic organic dyes may contain inorganic salts such as sodium sulfate as dyeing auxiliaries. The content of the dichroic organic dye in the aqueous solution may 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 may be above 20°C and below 80°C.

The boric acid treatment method after dyeing with a dichroic dye includes, for example, a method of immersing the dyed polyvinyl alcohol-based resin film in an aqueous solution containing boric acid. When iodine is used as a dichroic dye, the boric acid-containing aqueous solution preferably contains potassium iodide. The amount of boric acid in the boric acid-containing aqueous solution may 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 may be 0.1 part by mass or more and 20 parts by mass or less per 100 parts by mass of water. The temperature of the aqueous solution may be 50°C or higher, for example, 50°C or higher and 85°C or lower.

The polyvinyl alcohol-based resin film after the boric acid treatment is usually washed with water. The water washing treatment can be performed by, for example, immersing the boric acid-treated polyvinyl alcohol-based resin film in water. The temperature of the water in the water washing treatment is usually 5°C or higher and 40°C or lower. After washing with water, a drying treatment is performed to obtain a polarizer 30 .

The drying treatment system can be performed using a hot air dryer or a far-infrared heater. By forming the hardened|cured material layer of the curable composition (S) on the surface of this polarizer 30, a polarizing plate can be obtained. As described above, the polarizing plate may further include the first thermoplastic resin film 10, the second thermoplastic resin film 20, the second cured product layer, and the like.

Moreover, as another example of the manufacturing method of the polarizer 30, the method described in Unexamined-Japanese-Patent No. 2000-338329 and Unexamined-Japanese-Patent No. 2012-159778 is mentioned, for example. In this method, a solution containing a polyvinyl alcohol-based resin is applied on the surface of a base film to provide a resin layer, and then a laminate film composed of a base film and a resin layer is stretched, and then dyed, cross-linked A polarizer layer (polarizer 30 ) is formed from the resin layer by a combined treatment or the like. After the polarizer layer of the polarizing laminated film composed of the base film and the polarizer layer is bonded to the first thermoplastic resin film 10 as a protective film or the like via the curable composition (S), the base film is peeled off and removed. , the polarizing plate of the structure shown in Fig. 2 can be made. When the polarizer layer exposed by peeling of the base film is further bonded to the second thermoplastic resin film 20 via the curable composition, a polarizing plate having the configuration shown in FIG. 3 is obtained.

The thickness of the polarizer 30 can be set to 40 μm or less, preferably 30 μm or less (for example, 20 μm or less, more preferably 15 μm or less, and more preferably 10 μm or less or 8 μm or less). According to the methods described in Japanese Patent Laid-Open No. 2000-338329 and Japanese Patent Laid-Open No. 2012-159778, the polarizer 30 of the film can be more easily produced, and it becomes easier to set the thickness of the polarizer 30 to be, for example, 20 μm or less, Further, it is 15 μm or less, still further 10 μm or less, or 8 μm or less. The thickness of the polarizer 30 is usually 2 μm or more. The thickness of the polarizer 30 is reduced, which is beneficial to the thinning of the polarizer and even the image display device.

[4] Thermoplastic resin film

The first thermoplastic resin film 10 and the second thermoplastic resin film 20 can each be a light-transmitting (preferably optically transparent) thermoplastic resin, for example, a chain-shaped polyolefin-based resin (polypropylene-based resin, etc.), Polyolefin-based resins such as cyclic polyolefin-based resins (norbornene-based resins, etc.); cellulose ester-based resins such as cellulose triacetate and cellulose diacetate; polyethylene terephthalate, polyethylene naphthalate A film composed of polyester-based resins such as diesters and polybutylene terephthalate; polycarbonate-based resins; (meth)acrylic-based resins; or mixtures and copolymers of these.

The first thermoplastic resin film 10 and the second thermoplastic resin film 20 may each be an unstretched film or a uniaxially or biaxially stretched film. The biaxial extension may be simultaneous biaxial extension in two extension directions, and successive biaxial extension in a second direction different from the extension in the first direction.

The first thermoplastic resin film 10 and/or the second thermoplastic resin film 20 may be a protective film that functions to protect the polarizer 30, or may also be a protective film that also serves as an optical function such as a retardation film.

The retardation film is an optical functional film for the purpose of compensation of the retardation due to the liquid crystal cell of the image display element, and the like. For example, a retardation film with an arbitrary retardation value can be formed by stretching a film made of the thermoplastic resin described above (uniaxial stretching, biaxial stretching, etc.), or forming a liquid crystal layer on the thermoplastic resin film.

As the chain polyolefin-based resin, in addition to homopolymers of chain olefins such as polyethylene resins and polypropylene resins, copolymers composed of two or more kinds of chain olefins can be exemplified.

Cyclic polyolefin-based resin is a general term for resins containing cyclic olefins as polymerized units, represented by norbornene or tetracyclododecene (alias: dimethylene octahydronaphthalene, DIMETHANOOCTAHYDRONAPHALENE) or their derivatives. . Cyclic polyolefin-based resins include ring-opening (co)polymers of cyclic olefins and hydrogenated products thereof, addition polymers of cyclic olefins, cyclic olefins and chain olefins such as ethylene and propylene, or those having a vinyl group. Copolymers of aromatic compounds, and modified (co)polymers modified with unsaturated carboxylic acids or derivatives thereof, etc.

Among them, it is preferable to use a norbornene-based resin that uses a norbornene-based monomer such as norbornene or a polycyclic norbornene-based monomer as the cyclic olefin.

The cellulose ester resin can be a resin in which at least a part of the hydroxyl groups in cellulose is esterified with acetic acid, a part of which is esterified with acetic acid, and a mixed ester in which a part is esterified with other acids. The cellulose ester-based resin is preferably a cellulose acetate-based resin.

The cellulose acetate-based resins include cellulose triacetate, cellulose diacetate, cellulose acetate propionate, cellulose acetate butyrate, and the like.

The polyester-based resin is generally a resin other than the above-mentioned cellulose ester-based resin having an ester bond, and is composed of a polycondensate of a polyvalent carboxylic acid or a derivative thereof and a polyhydric alcohol.

Examples of polyester-based resins include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and polytrimethylene terephthalate. , Polypropylene naphthalate, polycyclohexane dimethyl terephthalate, polycyclohexane dimethyl naphthalate, etc.

Among them, polyethylene terephthalate is preferably used from the viewpoints of mechanical properties, solvent resistance, scratch resistance, cost, and the like. The term "polyethylene terephthalate" refers to a resin in which 80 mol% or more of the repeating unit is composed of ethylene terephthalate, and may contain structural units derived from other copolymerization components.

As another copolymerization component system, a dicarboxylic acid component or a diol component is mentioned.

Examples of dicarboxylic acid components include isophthalic acid, 4,4'-dicarboxydiphenyl, 4,4'-dicarboxybenzophenone, bis(4-carboxyphenyl)ethyl Alkane, adipic acid, sebacic acid, 5-sodium sulfoisophthalic acid, 1,4-dicarboxycyclohexane, etc.

Examples of glycol components include: propylene glycol, butylene glycol, neopentyl glycol, diethylene glycol, cyclohexane glycol, ethylene oxide adducts of bisphenol A, polyethylene glycol, polypropylene glycol, polytetraethylene glycol Methyl glycol, etc.

A dicarboxylic acid component and a diol component can also be used in combination of 2 or more types respectively as needed.

Moreover, hydroxycarboxylic acids, such as p-hydroxybenzoic acid, p-hydroxyethoxybenzoic acid, and (beta)-hydroxyethoxybenzoic acid, may be used together with both the said dicarboxylic acid component and diol component.

As for other copolymerization components, a small amount of dicarboxylic acid components and/or diol components having an amide bond, urethane bond, ether bond, carbonate bond and the like may be used.

Polycarbonate resins are polyesters formed from carbonic acid and diols or bisphenols. Among them, from the viewpoints of heat resistance, weather resistance, and acid resistance, aromatic polycarbonates having diphenylalkanes in the molecular chain are preferably used.

Polycarbonates include: 2,2-bis(4-hydroxyphenyl)propane (alias bisphenol A), 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyl) Polycarbonates derived from bisphenols such as phenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)isobutane, 1,1-bis(4-hydroxyphenyl)ethane, etc.

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 methacrylates and acrylates.

Examples of methacrylates include: methyl methacrylate, ethyl methacrylate, n-, iso- or tert-butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate , 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, etc.

Examples of the acrylate include ethyl acrylate, n-, iso- or tert-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 composed of only structural units derived from (meth)acrylic monomers, and may contain other structural units.

In a preferred embodiment, the (meth)acrylic resin contains methyl methacrylate, or contains methyl methacrylate and methyl acrylate as copolymerization components.

In a preferred embodiment, the (meth)acrylic resin can be a polymer with methacrylate as the main monomer (containing more than 50% by mass), preferably a methacrylate and other copolymerization components. copolymerized copolymer.

Examples of other copolymerization components other than the above-mentioned acrylates include: methyl 2-(hydroxymeth)acrylate, methyl 2-(1-hydroxyethyl)acrylate, ethyl 2-(hydroxymethyl)acrylate, 2-(hydroxymethyl)acrylate Hydroxyalkyl acrylates such as n-, iso- or tert-butyl (hydroxymeth)acrylate; unsaturated acids such as methacrylic acid and acrylic acid; halogenated styrenes such as chlorostyrene and bromostyrene; vinyltoluene, α -Substituted styrenes such as methylstyrene; unsaturated nitriles such as acrylonitrile and methacrylonitrile; unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride; phenylmaleimide, cyclohexylmalein Unsaturated imines such as imines; and other monofunctional monomers.

As for the other monofunctional monomers mentioned above, only one type may be used alone, or two or more types may be used in combination.

A polyfunctional monomer can also be used as the above-mentioned other copolymerization components.

The polyfunctional monomers include: ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate ) acrylate, nonaethylene glycol di(meth)acrylate, tetradecylethylene glycol di(meth)acrylate, etc. ethylene glycol or oligomers of both terminal hydroxyl groups are (meth)acrylated to form Propylene glycol or its oligomers whose two terminal hydroxyl groups are (meth)acrylated; neopentyl glycol di(meth)acrylate, hexanediol di(meth)acrylate, butanediol Hydroxyl groups of dihydric alcohols such as alcohol di(meth)acrylates are esterified with (meth)acrylates; bisphenol A, alkylene oxide adducts of bisphenol A, or two of these halogen substitution products The terminal hydroxyl group is esterified with (meth)acrylate; the polyol such as trimethylolpropane and neotaerythritol is esterified with (meth)acrylate, and the terminal hydroxyl group is (methyl) Epoxy ring-opening addition of glycidyl acrylate; dibasic acids such as succinic acid, adipic acid, terephthalic acid, phthalic acid, halogen substitutions of these, or alkylene oxides of these The finished product, etc., the epoxy group of (meth)acrylic acid glycidyl ester is ring-opened; (meth)acrylic acid aryl ester; 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 can be modified by the reaction between the functional groups possessed by the copolymer. Examples of this reaction include: demethanol condensation reaction of the methyl group of methyl (meth)acrylate and the hydroxyl group of methyl 2-(hydroxymeth)acrylate, and the carboxyl group of (meth)acrylic acid and the hydroxyl group of 2-(hydroxymethyl)acrylate. The dehydration condensation reaction of the hydroxyl group of methyl hydroxymeth)acrylate in the polymer chain, etc.

The glass transition point of the (meth)acrylic resin is preferably 80°C or higher and 160°C or lower. The glass transition point can be determined by the polymerization ratio of methacrylate-based monomer and acrylate-based monomer, the carbon chain length of each ester group and the type of functional group possessed by it, and the relative ratio of multifunctional monomer to monolayer. It can be controlled by adjusting the polymerization ratio of the whole body.

The means for increasing the glass transition point of the (meth)acrylic resin 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. Specifically, cyclic acid anhydride structures such as a glutaric anhydride structure and a succinic anhydride structure; a cyclic imide structure such as a cyclopentimide structure and a succinimide structure; ester ring structure.

The larger the content of the ring structure in the main chain, the higher the glass transition point of the (meth)acrylic resin tends to be.

Cyclic acid anhydride structure and cyclic imide structure can be introduced by copolymerizing monomers with cyclic structure such as maleic anhydride and maleimide; by dehydration/de-methanol condensation reaction after polymerization A method of introducing a cyclic acid anhydride structure; a method of introducing a cyclic imide structure by reacting an amine compound, and the like.

The resin (polymer) with lactone ring structure can be prepared from a polymer with hydroxyl groups and ester groups in the polymer chain, and the hydroxyl groups and ester groups in the obtained polymer can be heated and adjusted according to needs. In the presence of a catalyst such as an organophosphorus compound, it can be obtained by performing cyclocondensation to form a lactone ring structure.

The (meth)acrylic resin and the thermoplastic resin film formed therefrom may contain additives as required. Examples of additives include slip agents, pressure-resistant adhesives, heat stabilizers, antioxidants, antistatic agents, light fastness agents, impact resistance improvers, surfactants, and the like.

These additives can also be used when another 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 modifiers from the viewpoints of film formability for films, shock resistance of films, and the like. Acrylic rubber particles refer to particles containing an elastic polymer mainly composed of acrylic ester as an essential component, and examples include those having a single-layer structure substantially composed of only the elastic polymer, or the elastic polymer as one of the particles. A multi-layer structure of layers.

As an example of the said elastic polymer, the crosslinking elastic copolymer which has an acrylic alkyl group as a main component, and copolymerized the other vinylic monomer and crosslinkable monomer which can be copolymerized can be mentioned.

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 having an alkyl carbon number of 1 or more and 8 or less, preferably used Alkyl acrylate having an alkyl group having 4 or more carbon atoms.

Examples of other vinyl-based monomers that can be copolymerized with the above-mentioned alkyl acrylate include compounds having one polymerizable carbon-carbon double bond in the molecule, and more specifically, methyl methacrylates such as methyl methacrylate, etc. Acrylates; aromatic vinyl compounds such as styrene; vinyl cyanide compounds such as acrylonitrile, etc.

Examples of the crosslinkable monomers include compounds having crosslinkability of at least two polymerizable carbon-carbon double bonds in the molecule, and more specifically, ethylene glycol di(meth)acrylate, (meth)acrylates of polyhydric alcohols such as diol di(meth)acrylate; allyl (meth)acrylates such as allyl (meth)acrylate; divinylbenzene and the like.

A laminate of a film composed of a (meth)acrylic resin containing no rubber particles and a film composed of a (meth)acrylic resin containing rubber particles may be used as the thermoplastic resin film to be bonded to the polarizer 30 . In addition, the (meth)acrylic resin layer may be formed on one side or both sides of the retardation developing layer composed of a resin different from the (meth)acrylic resin, and the one that exhibits the retardation may be attached to the polarizer. 30 thermoplastic resin film.

Preferably, the first thermoplastic resin film 10 and the second thermoplastic resin film 20 each contain a material selected from the group consisting of cellulose ester-based resins, polyester-based resins, (meth)acrylic resins, and cyclic polyolefin-based resins. The film of one or more thermoplastic resins is more preferably a cellulose ester-based resin film, a polyester-based resin film, a (meth)acrylic resin film, or a cyclic polyolefin-based resin film.

The first thermoplastic resin film 10 and/or the second thermoplastic resin film 20 may contain an ultraviolet absorber. When a polarizing plate is applied to an image display device such as a liquid crystal display device, by arranging a thermoplastic resin film containing an ultraviolet absorber on the viewing side of the image display element (for example, a liquid crystal cell), the image display element can be inhibited. Deterioration caused by ultraviolet rays.

Examples of the ultraviolet absorber include salicylate-based compounds, benzophenone-based compounds, benzotriazole-based compounds, cyanoacrylate-based compounds, nickel zirconium salt-based 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 thickness, presence or absence of additives, their types, retardation characteristics, and the like.

The first thermoplastic resin film 10 and/or the second thermoplastic resin film 20 may have a hard coat layer, an anti-glare layer, an anti-reflection layer, a light-diffusing layer, an anti-reflection layer on the outer surface (the surface opposite to the polarizer 30) Surface treatment layer (coating layer) such as electrostatic layer, antifouling layer, conductive layer, etc.

The thicknesses of the first thermoplastic resin film 10 and the second thermoplastic resin film 20 are 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 still more preferably 15 μm or more and 65 μm or less. The thicknesses of the first thermoplastic resin film 10 and the second thermoplastic resin film 20 may be 50 μm or less, respectively, or 40 μm or less. Reducing the thicknesses of the first thermoplastic resin film 10 and the second thermoplastic resin film 20 is advantageous for the polarizing plate and even the thinning of the image display device.

On the surfaces of the first thermoplastic resin film 10 and the second thermoplastic resin film 20 on which the curable composition is applied, saponification treatment, plasma treatment, corona treatment, and primer may be performed from the viewpoint of improving adhesion. Surface modification treatment such as treatment may not be performed from the viewpoint of simplification of steps. The surface modification treatment can be performed in place of the bonding surface of the thermoplastic resin film, or on the bonding surface of the polarizer 30 together with the bonding surface.

When the first thermoplastic resin film 10 or the second thermoplastic resin film 20 is a cellulose ester resin film, it is preferable to perform a saponification treatment from the viewpoint of improving adhesion. The saponification treatment includes a method of immersing in an alkaline aqueous solution such as sodium hydroxide and potassium hydroxide.

[5] Second hardened material layer

The curable composition forming the second cured material layer 25 may be the above-mentioned curable composition (S), or may be another curable composition different from this. From the viewpoint of the optical durability of the polarizing plate, etc., the second cured product layer 25 is preferably a cured product layer of the curable composition (S).

When the first cured product layer 15 and the second cured product layer 25 are formed of a curable composition (S), these curable compositions may have the same composition or different compositions.

Other curable compositions include known water-based adhesives in which curable adhesive components are dissolved or dispersed in water, and known active energy ray curable adhesives containing an active energy ray curable compound.

Examples of the water-based adhesive include those obtained by dissolving or dispersing adhesive components such as polyvinyl alcohol-based resins and urethane resins in water.

In order to improve the adhesiveness, the water-based adhesive containing a polyvinyl alcohol-based resin may contain polyaldehydes, melamine-based compounds, zirconia compounds, zinc compounds, glyoxal, glyoxal derivatives, water-soluble epoxy resins and other hardening properties ingredients or cross-linking agents.

Examples of the water-based adhesive containing a urethane resin include a polyester-based ionomer-type urethane resin and a water-based adhesive containing a compound having a glycidyloxy group. The polyester-based ionomer-type urethane resin is a urethane resin having a polyester skeleton and into which a small amount of an ionic component (hydrophilic component) is introduced.

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

The active energy ray-curable adhesive may be an adhesive containing an epoxy-based compound cured by cationic polymerization as a curable component, and preferably an ultraviolet-curable adhesive containing such an epoxy-based compound as a curable component agent. The epoxy-based compound refers to a compound having, on average, one or more, preferably two or more, epoxy groups in the molecule. Only one type of epoxy-based compound may be used, or two or more types may be used in combination.

Examples of the epoxy-based compound include: a hydrogenated epoxy-based compound (having an alicyclic ring) obtained by reacting epichlorohydrin among alicyclic polyols obtained by hydrogenating the aromatic ring of an aromatic polyol. glycidyl ethers of polyhydric alcohols); aliphatic epoxy-based compounds such as polyglycidyl ethers of aliphatic polyhydric alcohols or their alkylene oxide adducts; having at least one bond in the molecule to an alicyclic Alicyclic epoxy-based compounds and the like of epoxy-based compounds of epoxy groups of rings.

The active energy ray-curable adhesive may contain the epoxy-based compound and a radically polymerizable (meth)acrylic-based compound in place of the epoxy-based compound as a curable component. Examples of the (meth)acrylic compound include: (meth)acrylate monomers having one or more (meth)acryloyloxy groups in the molecule; those obtained by reacting two or more functional group-containing compounds; A compound containing a (meth)acryloyloxy group, such as a (meth)acrylate oligomer having at least two (meth)acryloyloxy groups in the molecule.

When the active energy ray-curable adhesive contains, as a curable component, an epoxy-based compound cured by cationic polymerization, it is preferable to contain 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; iron-allene complexes and the like.

When the active energy ray-curable adhesive contains a radical polymerizable component such as a (meth)acrylic compound, it is preferable to contain a photoradical polymerization initiator. Examples of photo-radical polymerization initiators include acetonitrile-based initiators, benzophenone-based initiators, benzoin ether-based initiators, thioxanthone-based initiators, xanthone, Penone, camphorquinone, benzaldehyde, anthraquinone, etc.

The polarizing plate may contain an adhesive layer instead of the second cured material layer 25 . That is, the second thermoplastic resin film 20 may be bonded to the polarizer 30 via an adhesive layer. Regarding the adhesive layer, the description of the adhesive layer described later is cited.

[6] Manufacture of polarizing plate

By laminating and adhering the first thermoplastic resin film 10 on one side of the polarizer 30 with the first cured material layer 15 interposed therebetween, a polarizer having the structure shown in FIG. 2 can be obtained. The second thermoplastic resin film 20 is further laminated along with the second cured product layer 25, whereby a polarizing plate having the configuration shown in FIG. 3 can be obtained.

When manufacturing a polarizing plate having both the first thermoplastic resin film 10 and the second thermoplastic resin film 20, these films may be laminated and bonded on one side in stages, or films on both sides may be laminated and bonded simultaneously.

The method of bonding the polarizer 30 and the first thermoplastic resin film 10 may include applying the curable composition (S) on either or both sides of the bonding surface of the polarizer 30 and the first thermoplastic resin film 10, The other bonding surface is laminated thereon, for example, a method of pressing from top to bottom using a bonding roller or the like and bonding.

For the coating of the curable composition (S), various coating methods such as a doctor blade, a wire bar, a die-slot coater, a notch coater, and a gravure coater can be used. Moreover, the polarizer 30 and the 1st thermoplastic resin film 10 may be continuously supplied so that the bonding surface of both may become an inner side, and the form of casting a curable composition (S) therebetween may be sufficient.

After the polarizer 30 and the first thermoplastic resin film 10 are bonded together, it is preferable to perform heat treatment on the laminate of the polarizer 30 , the first cured product layer 15 , and the first thermoplastic resin film 10 . 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. Moreover, the curing/crosslinking reaction of the curable composition can be carried out by this heat treatment.

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

When an active energy ray curable adhesive is used, after drying the curable composition layer as necessary, the curable composition layer is cured by irradiating with active energy rays.

The light source used for irradiating the active energy rays may be any that can generate ultraviolet rays, electron rays, X-rays, and the like. In particular, it is preferable to use a low-pressure mercury-vapor lamp, a medium-pressure mercury-vapor lamp, a high-pressure mercury-vapor lamp, an ultra-high-pressure mercury-vapor lamp, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, a metal halide lamp, etc., which have a luminescence distribution at a wavelength of 400 nm or less.

As shown in FIG. 1, a polarizing plate that does not have a first thermoplastic resin film on the first cured product layer 15 is coated with a curable composition (S) on the surface of the polarizing plate 30, and the obtained laminated body can be, for example, Manufactured by applying heat treatment at 80° C. for 300 seconds with a hot air dryer.

Moreover, after manufacturing the laminated body which consists of the separation film/curable composition (S)/polarizer 30, the separation film is peeled off, and after that, a heat treatment may be performed to manufacture the polarizing plate shown in FIG. 1 .

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, and still more preferably 20 nm or more and 1 μm or less. . The adhesive layer formed from the above-mentioned known water-based adhesive may have a similar thickness.

The thickness of the adhesive layer formed from 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, and more preferably 500 nm or more and 5 μm or less.

The thicknesses of the first cured product layer 15 and the second cured product layer 25 may be the same or different.

[7] Other components of polarizing plate

[7-1] Optical functional film

The polarizing plate may be provided with other optical functional films other than the polarizer 30 for imparting desired optical functions, and a preferable example thereof is a retardation film.

As described above, the first thermoplastic resin film 10 and/or the second thermoplastic resin film 20 may also serve as retardation films, but retardation films different from these films may be laminated. In the latter case, the retardation film is laminated between 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 an adhesive layer or an adhesive layer. The outer surface.

Examples of the retardation film include: birefringent films composed of a stretched film of a light-transmitting thermoplastic resin; films in which discotic liquid crystals or nematic liquid crystals are aligned and fixed; those formed by forming the above-mentioned liquid crystal layer on a substrate film, etc. .

The base film is usually a film made of a thermoplastic resin, and an example of the thermoplastic resin is a cellulose ester resin such as cellulose triacetate.

Examples of other optically functional films (optical members) that the polarizing plate may contain are condensing plates, brightness enhancement films, reflection layers (reflection films), transflective layers (transflective films), light diffusion layers (light diffusion layers) film) etc. These are generally the case where the polarizing plate is arranged on the polarizing plate on the back side (backlight side) of the liquid crystal cell.

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

Brightness enhancement films are used for the purpose of enhancing the brightness of liquid crystal display devices using polarizers. Specifically, a reflective polarizing separator designed to produce anisotropy in reflectance by laminating a plurality of films of mutually different refractive index anisotropy, and cholesterol supported on a base film Alignment film of type liquid crystal polymer or circularly polarized light separation sheet of aligned liquid crystal layer, etc.

In order to use the polarizing plate as a reflective type, transflective type, and diffusion type optical member, a reflective layer, a transflective layer, and a light diffusion layer are respectively provided. Reflective polarizers are used in liquid crystal display devices that reflect incident light from the viewing side for display. Since light sources such as backlights can be omitted, the liquid crystal display device can be easily reduced in thickness. The transflective polarizer is used in a type of liquid crystal display device that is reflective in bright places and displays with light from a backlight in dark places. Moreover, the polarizing plate of the diffusion type is used in a liquid crystal display device that provides light diffusivity and suppresses display defects such as moiré. The reflection layer, the transflective layer, and the light diffusion layer can be formed by known methods.

[7-2] Adhesive layer

The polarizing plate system of the present invention may contain an adhesive layer. As an adhesive layer, the image display element for bonding a polarizing plate to a liquid crystal cell etc., or the adhesive layer of another optical member is mentioned. The adhesive layer is laminated on the outer surface of the polarizer 30 in the polarizing plate with the structure shown in FIGS. 1 and 2, and is laminated on the first thermoplastic resin film 10 or on the polarizing plate with the structure shown in FIG. 3. The outer surface of the second thermoplastic resin film 20 is laminated on the first cured product layer 15 or the outer surface of the second thermoplastic resin film 20 in the polarizing plate with the configuration shown in FIG. 4, and the configuration shown in FIG. 5 The polarizing plate is laminated on the outer surface of the first hardened material layer 15 or the second hardened material layer 25 .

As the adhesive used in the adhesive layer, (meth)acrylic resins, polysiloxane-based resins, polyester-based resins, polyurethane-based resins, polyether-based resins, and the like can be used as base polymers . Among them, from the viewpoints of transparency, adhesive strength, reliability, weather resistance, heat resistance, reworkability, and the like, (meth)acrylic adhesives are preferred.

In the (meth)acrylic adhesive, a (meth)acrylic resin with a weight average molecular weight of 100,000 or more can be used as the base polymer, and the (meth)acrylic resin contains methyl, ethyl or Alkyl (meth)acrylates having an alkyl group with a carbon number of 20 or less, such as n-, iso- or tert-butyl, and (meth)acrylates containing functional groups such as (meth)acrylic acid or hydroxyethyl (meth)acrylate ) The acrylic monomer is prepared so that the glass transition point is preferably 25°C or lower, more preferably 0°C or lower.

The adhesive layer is formed on the polarizer by dissolving or dispersing the adhesive composition in an organic solvent such as toluene or ethyl acetate to prepare an adhesive solution, and directly coating it on the opposite surface of the polarizer to form an adhesive The method of forming an adhesive layer, or the method of forming an adhesive layer in a sheet shape on the separation film subjected to the release treatment, and transferring it to the opposite surface of the polarizing plate, etc. are performed.

The thickness of the adhesive layer can be determined according to the adhesive force and the like, but is appropriately within a range of 1 μm or more and 50 μm or less, preferably 2 μm or more and 40 μm or less.

The polarizing plate may contain the above-mentioned separation film. The separation membrane may be a membrane composed of polyethylene-based resins such as polyethylene, polypropylene-based resins such as polypropylene, polyester-based resins such as polyethylene terephthalate, and the like. Among them, the stretched film of polyethylene terephthalate is preferred.

The adhesive layer can contain fillers, pigments, colorants, antioxidants, ultraviolet absorbers, antistatic agents, etc., which are composed of glass fibers, glass beads, resin beads, metal powders, or other inorganic powders as required. .

[7-3] Protective film

The polarizing plate of the present invention may contain a surface for protecting the surface (typically, the surface 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) the protective film. The protective film is, for example, after the image display element or other optical members are attached to the polarizing plate, the entire adhesive layer is peeled off and removed.

The protective film is composed of, for example, a base film and an adhesive layer laminated thereon. Regarding the adhesive layer system, the above-mentioned description can be cited.

The resin constituting the base film may be, for example, a polyethylene-based resin such as polyethylene, a polypropylene-based resin such as polypropylene, and a polyester-based resin such as polyethylene terephthalate or polyethylene naphthalate , Polycarbonate resins and other thermoplastic resins. Preferred are polyester resins such as polyethylene terephthalate.

<Liquid crystal panel and liquid crystal display device>

The polarizing plate of the present invention can be used for liquid crystal panels and liquid crystal display devices. The liquid crystal panel includes a liquid crystal cell and polarizers disposed on both sides of the liquid crystal cell. The liquid crystal display device includes a liquid crystal panel and a backlight.

The polarizing plate of the present invention can be arranged on one side or both sides of the liquid crystal cell. An adhesive layer can be used to attach the polarizer and the liquid crystal cell.

An example of the optical laminated body which laminated|stacked a polarizing plate in a liquid crystal cell via an adhesive bond layer is shown in FIG. 6. FIG.

The optical lamination system shown in FIG. 6 is one in which the polarizing plate shown in FIG. 3 is laminated on one surface of the liquid crystal cell 50 with the adhesive layer 40 interposed therebetween, and includes the first thermoplastic resin film 10 and the first cured product layer 15 in this order. , the polarizer 30 , the second cured product layer 25 , the second thermoplastic resin film 20 , the adhesive layer 40 , and the liquid crystal cell 50 . Regarding the adhesive layer 40, the above description regarding the adhesive layer is cited.

The liquid crystal cell can be any, for example, liquid crystal cells can be formed using various liquid crystal cells such as an active matrix driving type liquid crystal cell represented by a thin film transistor type, a simple matrix driving type liquid crystal cell represented by a super twisted nematic type, and the like. Panels and liquid crystal display devices. The polarizers disposed on both sides of the liquid crystal cell may be the same or different.

[Example]

Hereinafter, although an Example is shown and this invention is demonstrated more concretely, this invention is not limited by these examples. In the example, the % and part indicating the content or usage amount are based on the mass unless otherwise specified.

唑啉基之聚合物(A)、具有羧基之化合物(B)、及促進含有

唑啉基之聚合物(A)的

唑啉基與化合物(B)的羧基反應的化合物(C)分別簡稱為(A)、(B)、(C)。 Table 1, contains

An oxazoline group-containing polymer (A), a carboxyl group-containing compound (B), and an accelerator containing

oxazoline-based polymer (A)

The compound (C) in which the oxazoline group reacts with the carboxyl group of the compound (B) is abbreviated as (A), (B), and (C), respectively.

(Production example: production of polarizer)

After immersing a polyvinyl alcohol film with a thickness of 60 μm (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 immersion in iodine/potassium iodide/water is 0.02/2/100 the aqueous solution at 30°C. Then, it was immersed in the aqueous solution whose mass ratio of potassium iodide/boric acid/water is 12/5/100 of 56.5 degreeC. Then, after washing with pure water at 8°C, it was dried at 65°C to obtain a polarizer having a thickness of 23 μm in which iodine was adsorbed and aligned on the polyvinyl alcohol film. The extension is mainly carried out by the steps of iodine dyeing and boric acid treatment, and the total extension ratio is 5.5 times.

<Examples 1 to 12, Comparative Examples 1 to 5>

(1) Preparation of curable composition

The components shown in Table 1 were mixed with pure water as a solvent in the preparation amounts shown in Table 1 to prepare a curable composition (aqueous adhesive solution). The unit of the compounding amount of each component shown in Table 1 is parts by mass, and the compounding amount of each component is the amount converted into a solid part. In each of Examples and Comparative Examples, the total concentration of (A) and (B) in the obtained curable composition was 3.0 mass %.

(2) Production of polarizing plate

Triacetate cellulose (TAC) film [trade name "KC4UAW" manufactured by Konica Minolta Opto Co., Ltd., thickness: 40 μm] was saponified on one side, and the saponified side was prepared with the above (1). The curable composition was applied using a rod coater, and a zero retardation film (trade name "ZEONOR" manufactured by Zeon Corporation, Japan) with a thickness of 23 μm was applied to one side The corona treatment was performed, and the curable composition prepared in the above (1) was applied to the corona treated surface using a rod coater. In such a way that the curable composition layer is on the polarizer side, a saponified TAC film is layered on one area of the polarizer, and a zero retardation film is layered on the other area to obtain a film with zero retardation/curable composition layer/polarizer/ A laminate composed of layers of curable composition layer/TAC film. This laminated body was heat-processed at 80 degreeC for 300 second with a hot air dryer, and the polarizing plate which has the layer structure of zero retardation film/cured material layer/polarizer/cured material layer/TAC film was produced. The thickness of each hardened layer in the produced polarizing plate is 20 to 60 nm.

(3) Evaluation of Optical Durability

The obtained polarizing plate was cut into a size of 30 mm×30 mm, and then a glass substrate was bonded to the zero retardation film side via a (meth)acrylic adhesive to obtain a measurement sample. The layer constitution of the measurement sample is glass substrate/(meth)acrylic adhesive layer/zero retardation film/cured material layer/polarizer/cured material layer/TAC film. For the glass substrate, an alkali-free glass substrate (trade name "Eagle XG" manufactured by Corning Corporation) was used.

For the obtained measurement sample, the MD transmittance and TD transmittance in the wavelength range of 380 to 780 nm were measured using a spectrophotometer with integrating sphere (product name "V7100" manufactured by Nippon Co., Ltd.), and calculated at The degree of polarization of each wavelength. For the calculated degree of polarization, the visibility correction is performed by the two-dimensional field of view (C light source) of JIS Z 8701:1999 "Representation of Color-XYZ Color System and X10Y10Z10 Color System", and the visibility correction before the durability test is obtained. Polarization Py.

In addition, the measurement sample was attached to the spectrophotometer with integrating sphere so that the TAC film side of the polarizing plate was the detector side, and light was incident from the glass substrate side.

The degree of polarization is defined by the following formula: degree of polarization (λ)=100×(Tp(λ)−Tc(λ))/(Tp(λ)+Tc(λ)).

Tp(λ) is the transmittance (%) of the measurement sample measured by the relationship between the linearly polarized light of the incident wavelength λ (nm) and the parallel Nicole.

Tc (λ) is the transmittance (%) of the measurement sample measured by the relationship between the linearly polarized light of the incident wavelength λ (nm) and the crossed Nicols.

Then, the measurement sample was subjected to an endurance test, which 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 in an environment with a temperature of 23°C and a relative humidity of 50%RH. Leave for 24 hours. After the endurance test, the visibility correction polarization degree Py was obtained by the same method as before the endurance test.

The absolute value (|ΔPy|) of the difference between the visibility correction polarization degree Py after the durability test and the visibility correction polarization degree Py before the durability test was calculated, and the optical durability of the polarizing plate was evaluated. Table 1 shows the calculated values of |ΔPy|.

The smaller |ΔPy|, the better the optical durability. In any of the Examples and Comparative Examples, the difference between the visibility correction polarization degree Py after the durability test and the visibility correction polarization degree Py before the durability test shows a negative value.

The details of each component shown in Table 1 are as follows.

唑啉基作為側鏈之含有

唑啉基的丙 烯酸系聚合物之水溶液、固形份濃度：10質量%、

唑啉價(理論值)：130g固體/eq.、

唑啉基量(理論值)：7.7mmol/g‧固體、數量平均分子量：4×10⁴、重量平均分子量：12×10⁴)〕 a1: The trade name "EPOCROS WS-300" manufactured by Nippon Shokubai Co., Ltd. [with 2-

The oxazoline group is contained as a side chain

Aqueous solution of oxazoline-based acrylic polymer, solid content concentration: 10% by mass,

Oxazoline valence (theoretical value): 130g solid/eq.,

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 Japan VAM & POVAL Co., Ltd. [carboxy-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

x1: Trade name "Gohsefimer Z-200" manufactured by Nippon Synthetic Chemical Industry Co., Ltd. [Acetyl acetyl group-modified polyvinyl alcohol, average degree of polymerization: 1100, degree of saponification: 98.5 mol% or more]

y1: glyoxal

15‧‧‧First hardened layer

30‧‧‧Polarizer

Claims (5)

A polarizing plate comprising a polarizer, a first cured product layer and a first thermoplastic resin film in this order, wherein the first cured product layer is a cured product layer of a curable composition, the curable composition comprising:

An oxazoline group-containing polymer (A), a carboxyl group-containing compound (B), and an accelerator containing

oxazoline-based polymer (A)

oxazoline group, compound (C) reacted with the carboxyl group of compound (B);

The total amount of the oxazoline-based polymer (A) and the compound (B) is 100 parts by mass, the content of the compound (B) in the curable composition is 0.01 parts by mass to 15 parts by mass, and the curable composition is The content of the compound (C) is more than 10 parts by mass and not more than 100 parts by mass; the compound (B) has two or more carboxyl groups in the molecule; the compound (C) is an acid compound; the first cured product layer is a An adhesive layer for bonding the polarizer and the first thermoplastic resin film. The polarizing plate according to claim 1, wherein the molecular weight of the compound (B) is 1,000 or less. The polarizing plate according to claim 1, wherein the first thermoplastic resin film comprises a resin selected from the group consisting of cellulose ester-based resins, polyester-based resins, (meth)acrylic-based resins, and cyclic polyolefin-based resins One or more thermoplastic resins in the group. The polarizing plate as described in any one of claims 1 to 3, wherein The second thermoplastic resin film, the second cured product layer, the polarizer, the first cured product layer, and the first thermoplastic resin film are included in this order. The polarizing plate according to any one of claims 1 to 3, wherein the polarizing plate comprises a polyvinyl alcohol-based resin.

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