JP2019185061A - Polarizing plate with adhesive layer and manufacturing method of the same, active energy ray curable polymer composition used for the manufacture, and liquid crystal display - Google Patents

Abstract

To provide a polarizing plate with an adhesive layer including: a polarizing plate protective film only on one face of a polarization element; and an adhesive layer having an antistatic agent, such as ionic liquid formulated therein on the other face of the polarization element, the polarizing plate with an adhesive layer having moisture heat durability exhibiting good optical characteristics even after a moisture heat durability test.SOLUTION: There is provided a polarizing plate with an adhesive layer including a transparent protective film (PF1) on one face of a polarization element (P) obtained by causing a polyvinyl alcohol resin layer to adsorb and align iodine, and a cured layer (BL1) and an antistatic agent-containing adhesive layer on the other face, where the cured layer (BL1) has an average film thickness of 0.5 to 10 μ, and is formed of an aqueous solution of an active energy ray-curable polymer composition including, as a main component, a polymer compound having an ethylenically unsaturated group.SELECTED DRAWING: None

Description

  The present invention relates to a polarizing plate with a pressure-sensitive adhesive layer having a cured layer formed from an ionizing radiation curable composition of a specific water solvent on a polarizing element obtained by adsorbing and orienting iodine to a polyvinyl alcohol resin layer, and the polarization thereof. The present invention relates to a method for manufacturing a plate. Furthermore, the present invention relates to an active energy ray-curable polymer composition used for producing the polarizing plate and an image display device such as a liquid crystal display device using the polarizing plate.

  Liquid crystal display devices (LCDs) are widely used for liquid crystal panels such as liquid crystal televisions, personal computers, mobile phones, and digital cameras. Usually, the liquid crystal display device has a liquid crystal panel member in which polarizing plates are bonded to both sides of a liquid crystal cell, and display is performed by controlling light from the backlight member with the liquid crystal panel member. Here, the polarizing plate is composed of a polarizing element and a protective film bonded to both sides thereof, and a general polarizing element is obtained by dyeing a stretched polyvinyl alcohol (PVA) film with iodine or a dichroic dye. As a protective film, a cellulose acylate film or the like is used.

In recent years, in order to reduce the thickness of the liquid crystal panel, the polarizing plate protective film on the liquid crystal cell side is eliminated from the two protective films bonded to both surfaces of the polarizing element.
On the other hand, an antistatic agent such as an ionic liquid may be added to the pressure-sensitive adhesive layer to prevent static electricity generated when the release film is peeled off when the polarizing plate with the pressure-sensitive adhesive is bonded to a liquid crystal display device. Proposed. (For example, Patent Document 1)
Combining the above, in a single-sided polarizing plate having a protective film only on one side of the polarizer, the pressure-sensitive adhesive layer is laminated on the polarizing element without a protective film, as described in Patent Document 2. When a pressure-sensitive adhesive layer having an ionic liquid or an ionic solid is laminated on a polarizing element without a protective film, the polarizing element is deteriorated, so that the wet heat durability performance is lowered, and as a result, the optical characteristics are greatly reduced.

International Publication No. 2007/034533 Pamphlet JP 2014-048497 A

  In view of the above situation, the problem of the present invention, that is, the problem to be solved by the present invention, is that the polarizing element has a polarizing plate protective film only on one surface and the other surface of the polarizing element has ions. A polarizing plate with a pressure-sensitive adhesive layer, which has a pressure-sensitive adhesive layer blended with an antistatic agent such as an ionic liquid, and has excellent heat resistance and moisture resistance even after a wet heat durability test Is to provide a board.

  As a result of intensive studies, the present inventors have estimated that the decrease in optical properties after the wet heat durability test is due to the movement of the antistatic agent in the adhesive and the iodine complex in the polarizing element using moisture as a medium. ) An ultraviolet curable composition in which an acrylate monomer and a photopolymerization initiator are dissolved in an organic solvent is applied onto a polarizing element of a single-sided polarizing plate, dried, and then irradiated with UV under a nitrogen purge to provide a cured layer. It has been found that the movement of the polarizing plate can be suppressed and the wet heat durability of the polarizing plate is improved.

However, in a polarizing plate manufacturing process using a polarizing element prepared by adsorbing and orienting iodine to a polyvinyl alcohol resin layer, usually, organic solvents are hardly used. Therefore, it corresponds to explosion-proof, recovery of organic solvents after drying, etc. It is not organic solvent specification. Therefore, in order to introduce the above method into the manufacturing process of the polarizing plate, the manufacturing equipment must be modified to an organic solvent specification, which places a significant burden on the polarizing plate manufacturer. In addition, the use of organic solvents (VOC) has brought about a new problem that the burden on the environment increases.
In addition, when a polyfunctional (meth) acrylate monomer is used, if UV irradiation is performed in the air without using a nitrogen purge facility, the cured layer surface becomes unreacted due to the inhibition of curing by oxygen. Problems such as adhering will occur. Therefore, a new problem that necessitates the introduction of nitrogen purge equipment has also arisen.

In view of the above situation, the problem of the present invention, that is, the problem to be solved by the present invention is that the polarizing element has a polarizing plate protective film only on one surface and the other surface has an ionic liquid or the like. A polarizing plate with a pressure-sensitive adhesive layer that has a pressure-sensitive adhesive layer and a thin polarizing plate with a pressure-sensitive adhesive layer, but has good heat resistance even after a wet heat durability test. It is to provide a polarizing plate by a method with a small modification load in the manufacturing process of the polarizing plate and a low environmental load, and also provides an active energy ray-curable polymer composition for producing such a polarizing plate. It is to be.
Another object of the present invention is to provide a method for producing such a polarizing plate, and yet another object of the present invention is a liquid crystal having wet heat resistance with improved display characteristics after a wet heat durability test. It is to provide a display device.

  As a result of intensive studies, the present inventors have a transparent protective film only on one surface of a polarizing element formed by adsorbing and orienting iodine to a polyvinyl alcohol resin, and on the opposite side of the transparent protective film of the polarizing element. A water-based active energy ray-curable composition containing a polymer compound having an ethylenically unsaturated group as a main component in a polarizing plate with an adhesive layer in which an adhesive layer containing an antistatic agent such as an ionic compound is laminated. The present inventors have found that optical property deterioration after a moisture resistance test can be suppressed by installing a cured layer having a specific thickness formed between the polarizing element and the pressure-sensitive adhesive layer, thereby completing the present invention.

Moreover, the cured layer of the present invention improves the wet heat durability of the polarizing plate by laminating between the polarizing element and the transparent protective film (PF2) on the liquid crystal cell side even in the polarizing plate having the transparent protective film on both sides of the polarizing element. As a result, the second invention was completed. In particular, as described above, it is presumed that the decrease in optical properties after the wet heat endurance test, which is the subject of the present invention, is generated using moisture as a medium. In the second aspect of the invention, the transparent protective film (PF2) on the liquid crystal cell side is used. The effect is observed when the cellulose acylate film has a relatively high moisture permeability thickness of 10 to 50 μm.
The problem to be solved by the present invention can be solved by the following means.

(1) A transparent protective film (PF1) is provided on one surface of a polarizing element (P) formed by adsorbing and orienting iodine to a polyvinyl alcohol resin layer, and a cured layer (BL1) and an antistatic agent are provided on the other surface. A pressure-sensitive adhesive layer-attached polarizing plate provided with a containing pressure-sensitive adhesive layer,
The cured layer (BL1) has an average film thickness of 0.5 to 10 μm, and is formed from an aqueous solution of an active energy ray-curable polymer composition whose main component is a polymer compound having an ethylenically unsaturated group. A polarizing plate with a pressure-sensitive adhesive layer.
(2) In the aqueous solution of the active energy ray-curable polymer composition, the content of the polymer compound having an ethylenically unsaturated group in the solid content is 50 to 99% by weight (1) ) Polarizing plate with an adhesive layer.

(3) The aqueous solution of the active energy ray-curable polymer composition is a self-emulsifying emulsion of a polymer composition having an ethylenically unsaturated group, described in (1) or (2) Polarizing plate with an adhesive layer.
(4) The polarizing plate with an adhesive layer according to any one of (1) to (3), wherein the polymer compound having an ethylenically unsaturated group is water-dispersible polyurethane (meth) acrylate. .
(5) The polarizing plate with an adhesive layer according to any one of (1) to (4), wherein the polymer compound having an ethylenically unsaturated group has a number average molecular weight of 5,000 to 100,000.

(6) The active energy ray-curable polymer composition further contains a polyfunctional (meth) acrylate compound, and the content of the polyfunctional (meth) acrylate compound is in an aqueous solution of the active energy ray-curable polymer composition. It is 1 to 40 weight% in solid content, The polarizing plate with an adhesive layer in any one of (1)-(5) characterized by the above-mentioned.
(7) The polarizing plate with the pressure-sensitive adhesive layer according to any one of (1) to (6), wherein the active energy ray-curable polymer composition further contains a radical photopolymerization initiator.
(8) The pressure-sensitive adhesive layer is provided directly or via a transparent protective film (PF2) on a surface opposite to the polarizing element (P) of the cured layer (BL1) of the polarizing plate ( The polarizing plate with an adhesive layer in any one of 1)-(7).
(9) The polarizing plate with the pressure-sensitive adhesive layer according to (8), wherein the transparent protective film (PF2) is a cellulose acylate film having a thickness of 10 to 50 μm.
(10) The polarizing plate with the pressure-sensitive adhesive layer according to any one of (1) to (9), wherein the pressure-sensitive adhesive layer contains an ionic antistatic agent.

(11) A cured layer (BL2) having a film thickness of 0.5 to 10 μm and having the same composition as the cured layer (BL1) is provided between the transparent protective film (PF1) and the polarizing element (P). The polarizing plate with an adhesive layer according to any one of (1) to (10), wherein
(12) A liquid crystal display device in which the polarizing plate according to any one of (1) to (11) is bonded to at least one side of a liquid crystal cell.
(13) An active energy ray-curable polymer composition used for production of the polarizing plate according to any one of (1) to (11), which has an ethylenically unsaturated group when formed into an aqueous solution. An active energy ray-curable polymer composition comprising a molecular compound in an aqueous solution solid content of 50 to 99% by weight and a polyfunctional (meth) acrylate compound in an aqueous solution solid content of 1 to 40% by weight. .

(14) A step of laminating a transparent protective film (PF1) only on one side of a polarizing element (P) formed by adsorbing and orienting iodine on a polyvinyl alcohol resin layer to form a single-side polarizing plate,
A step of applying an aqueous solution of an active energy ray-curable polymer composition whose main solvent is water on the polarizing element of the single-side polarizing plate;
A step of drying the applied aqueous solution of the active energy ray-curable polymer composition, irradiating the active energy ray under atmospheric pressure and normal atmosphere to form a cured layer, and an antistatic agent-containing pressure-sensitive adhesive layer The manufacturing method of the polarizing plate with an adhesive layer in any one of (1)-(11) characterized by including the process provided.

  According to the present invention, it is possible to provide a polarizing plate with a pressure-sensitive adhesive layer that is thin, has excellent antistatic properties, and has a resistance to wet heat resistance with little change in optical properties (such as a decrease in polarization degree) after a wet heat durability test. By using the polarizing plate with the pressure-sensitive adhesive layer of the present invention, it is possible to provide a display device in which light leakage after high temperature and high humidity environment aging is suppressed.

[Polarizing element]
A well-known polarizing element can be used for the polarizing element formed by adsorbing and orienting iodine to the polyvinyl alcohol (hereinafter also referred to as PVA) resin layer of the present invention. Such a polarizing element is generally formed by using a PVA resin film, dyeing this PVA resin film with iodine, and uniaxially stretching it.

  As described above, the PVA resin is generally obtained by saponifying a polyvinyl acetate resin. The degree of saponification is about 85 mol% or more, preferably about 90 mol% or more, more preferably about 99 mol% to 100 mol%. Polyvinyl acetate resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith, such as ethylene-vinyl acetate copolymer. Examples include coalescence. Examples of other copolymerizable monomers include unsaturated carboxylic acids, olefins, vinyl ethers, and unsaturated sulfonic acids. The degree of polymerization of the PVA resin is 1000 to 10000, preferably 1500 to 5000. This PVA-based resin may be modified, for example, polyvinyl formal modified with aldehydes, polyvinyl acetal, polyvinyl butyral, and the like.

The manufacturing method of the polarizing element is not particularly limited, but a method of producing a polyvinyl alcohol-based resin film that has been previously wound in a roll shape by feeding, stretching, dyeing, cross-linking, and the like, and a polyvinyl alcohol-based resin and a stretching resin substrate A method including a step of producing a laminate and stretching the laminate in a state of the laminate is typical. In the present invention, any of these methods can be used.
Manufacturing methods of these polarizing elements are described in paragraphs [0109] to [0128] of JP-A-2014-48497, and these methods can be used in the present invention. Moreover, the thickness of the polarizing element of the present invention is preferably from 3 to 35 μm, more preferably from 4 to 30 μm, still more preferably from 5 to 25 μm.

[Hardened layer]
The cured layers (BL1) and (BL2) of the present invention are formed from an aqueous solution of an active energy ray-curable polymer composition containing, as a main component, a polymer compound having an ethylenically unsaturated group and a main solvent being water. The main component of the polymer compound having an ethylenically unsaturated group in the present invention is the content of the polymer compound having an ethylenically unsaturated group in the aqueous solution solid content of the curable polymer composition. Means that. The polymer compound having an ethylenically unsaturated group may be one type or two or more types. When there are two or more types of polymer compounds having an ethylenically unsaturated group, “content of polymer compound having an ethylenically unsaturated group” means the content of all polymer compounds having an ethylenically unsaturated group (compounds) The sum of the individual contents).

The content of the polymer compound having an ethylenically unsaturated group in the solid content of the active energy ray-curable polymer composition is preferably 50 to 99% by weight, more preferably 70 to 99% by weight, and 80 to 99% by weight. Further preferred. By suppressing the content within this range, it is possible to suppress a change in optical characteristics after the moisture resistance test of the polarizing plate on which the cured layer is laminated.
In the configuration of the polarizing plate having two layers of the cured layers (BL1) and (BL2), the cured layers (BL1) and (BL2) may be formed from the same active energy ray-curable polymer composition. Although it is preferable in terms of productivity, it may be formed from different active energy ray-curable polymer compositions.

In the active energy ray-curable polymer composition of the present invention, at least a part of the polymer compound having an ethylenically unsaturated group is a polymer emulsion having an ethylenically unsaturated group. This is preferable. The present inventors speculate that a hydrophobic structure is preferable for improving wet heat durability, but the emulsion type polymer compound has a hydrophobic structure,
It is preferable from the viewpoint of improving wet heat durability.
In addition, emulsion type polymer compounds include a forced emulsification type that uses a surfactant as an emulsifier and a self-emulsification type in which a hydrophilic group is introduced into the compound. There is no bleed out, which is more preferred in the present invention.

  Next, a water-dispersible polyurethane (meth) acrylate, which is a self-emulsifying emulsion having a polyurethane structure and having a (meth) acrylate group, which can be preferably used as an active energy ray-curable polymer compound in the present invention will be described. To do.

(Water-dispersible polyurethane (meth) acrylate)
Generally, polyurethane is a reaction product of polyol and polyisocyanate, but at least a part of the polyol is hydrophilic to polyurethane by using a polyol having a functional group (hydrophilic group) having ionic or nonionic hydrophilic properties. Groups can be introduced. Preferred examples of such polyols include one or more acidic groups that can be converted into anionic salt groups such as carboxylates and sulfonates, or anionic bases such as carboxylic acid groups or sulfonic acid groups. A polyol is mentioned. Specifically, α, α-dimethylolalkanoic acid such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid and the like can be mentioned as examples of preferable polyols.

Similarly, a (meth) acryloyl group can be introduced into a polyurethane by using a polyol having a (meth) acryloyl group in at least a part of the polyol. As such a compound, a (meth) acryloyl dihydroxy compound and a poly (meth) acryloyl dihydroxy compound are preferable.
Alternatively, a (meth) acryloyl group can be introduced into the polyurethane by end-capping with a hydroxy-functional (meth) acrylate compound after synthesizing the isocyanate-terminated polyurethane. These methods can be used in combination.

  As the water-dispersed polyurethane (meth) acrylate of the present invention, those described as radiation-curable polyurethane dispersions in [0017] to [0028] of JP-A-2014-529639 can be preferably used.

Commercially available water-dispersed polyurethane (meth) acrylates can also be used, for example, UCECOAT (registered trademark) 7664, UCECOAT (registered trademark) 7655, UCECOAT (registered trademark) 7699, UCECOAT (registered trademark) 7571, UCECOAT. (
Registered trademark) 7689, UCECOAT (registered trademark) 7690, UCECOAT (registered trademark) 7
890, UCECOAT (registered trademark) 7578, UCECOAT (registered trademark) 7710, UCECOAT (registered trademark) 7730, UCECOAT (registered trademark) 7733, etc. It can be preferably used.

Among them, UCECOAT (registered trademark) 7571, UCECOAT (registered trademark) 7655, UCECOAT (registered trademark) 7689, UCECOAT (which becomes tack-free when water is removed)
(Registered trademark) 7849 is more preferable, and UCECOAT (registered trademark) 7571 is particularly preferable.
The reason is that if water-dispersed polyurethane (meth) acrylate that becomes tack-free when the moisture is removed, problems such as fouling the handling roll can be avoided without providing a nitrogen purge facility in the UV irradiation facility. This is because the nitrogen purge equipment can be omitted, and the modification burden of the polarizing plate manufacturing process is reduced.

(Multifunctional (meth) acrylate)
The active energy ray-curable polymer composition of the present invention preferably further contains a polyfunctional (meth) acrylate compound in addition to the self-emulsifying emulsion composed of a polymer compound having an ethylenically unsaturated group. Hydrophobic polyfunctional (meth) acrylate compounds are difficult to disperse in water by themselves, but when used in combination with self-emulsifying emulsions, dispersion into aqueous solutions becomes possible, and the wet heat durability improvement effect of polarizing plates is further increased. be able to.
The polyfunctional (meth) acrylate compound that can be preferably used in the present invention is an ester of a polyhydric alcohol and (meth) acrylic acid, among which (meth) acrylic equivalent (molecular weight / functional group number) is 50 to 300, Those having a viscosity of 30 to 1000 mPa · s (25 ° C.) are preferable because they are relatively easy to disperse and have an effect of improving wet heat durability.

  Examples of such compounds include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, and triethylene. Glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, EO modified pentaerythritol tetra (meth) acrylate, PO modified pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) Acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate , Ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, etc. It is done.

Among them, pentaerythritol tetra (meth) acrylate, EO-modified pentaerythritol tetra (meth) acrylate, PO-modified pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO-modified trimethylol Propane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and tricyclodecane dimethanol di (meth) acrylate are preferred.
These can be used in combination of two or more. Moreover, the commercial item containing two or more types can also be used.

  The polyfunctional (meth) acrylate of this invention can use what is marketed, NK ester A-DCP, DCP, A-TMPT, TMPT, ATM-35E, A-TMMT by Shin-Nakamura Chemical Co., Ltd. , Biscoat (registered trademark) # 195, Biscoat (registered trademark) # 300, Biscoat (registered trademark) # 360, manufactured by Osaka Organic Chemical Industry Co., Ltd., acrylate monomer IRR 214-K, PETIA, PETRA, manufactured by Daicel Ornex Co., Ltd. , TMPTA, TMPEOTA, EBECRYL 135, OTA 480, EBERCRYL 40, BS710, BS730 manufactured by Arakawa Chemical Industries, Ltd., and the like.

  The content of the polyfunctional (meth) acrylate of the present invention is preferably 1 to 40% by weight, and preferably 5 to 25% by weight in the solid content of the active energy ray-curable polymer composition (BLC). Is more preferable, and it is still more preferable that it is 8 to 20 weight%. By setting it as this range, the wet heat durability of the polarizing plate provided with the cured layer is good, and a composition with good dispersibility can be prepared.

(Polymerization initiator)
The active energy ray-curable polymer composition of the present invention preferably contains a polymerization initiator, and the polymerization initiator is preferably a photopolymerization initiator. Regarding these polymerization initiators, the description in paragraphs [0064] to [0067] of JP 2014-170130 A can be referred to.
As photopolymerization initiators, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, Examples include fluoroamine compounds, aromatic sulfoniums, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, and coumarins. Specific examples, preferred embodiments, commercially available products, and the like of the photopolymerization initiator are described in paragraphs [0133] to [0151] of JP-A-2009-098658, and can be suitably used in the present invention as well. it can.
In the present invention, a photoinitiator that is liquid at room temperature or a water-soluble photopolymerization initiator is preferable because of good dispersibility.

Commercially available photocleavable photoradical polymerization initiators include “Irgacure (registered trademark) 651”, “Irgacure (registered trademark) 184”, and “Irgacure (registered trademark) 81” manufactured by BASF.
9 ”,“ Irgacure® 907 ”,“ Irgacure® 1870 ”(CGI-403 / Irgacure® 184 = 7/3 mixed initiator),“ Irgacure® 500 ”,“ "Irgacure (registered trademark) 369", "Irgacure (registered trademark) 11"
73 "," Irgacure (registered trademark) 2959 "," Irgacure (registered trademark) 4265 "," Irgacure (registered trademark) 4263 "," Irgacure (registered trademark) 127 "," OXE01 ", etc .; Nippon Kayaku Co., Ltd. "Kayacure (registered trademark) DETX-S", "Kayacure (registered trademark) BP-100", "Kayacure (registered trademark) BDMK", "Kayacure (registered trademark) CTX", "Kayacure (registered trademark) BMS""Kayacure (registered trademark) 2-EAQ", "Kayacure (registered trademark) ABQ", "Kayacure (registered trademark) CPTX", "Kayacure (registered trademark) EPD", "Kayacure (registered trademark) ITX", "Kayacure (registered trademark) ITX" (Registered trademark) QTX "," Kayacure (registered trademark) BTC "," Kayacure (registered trademark) MCA ", etc .;" Esac "manufactured by Sartomer ure (registered trademark) (KIP100F, KB1, EB3, BP, X33, KTO46, KT37, KIP150, TZT) "and the like, and combinations thereof are preferable examples.

Among them, as an initiator liquid at room temperature, “Irgacure (registered trademark) 1173” 2-hydroxy-2-methyl-1-phenyl-propan-1-one or water-soluble “Irgacure (registered trademark) 2959” (1- [ 4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one) is more preferable, and water-soluble “Irgacure (registered trademark) 2959” (1- [4- ( 2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one) is most preferred.

  The content of the photopolymerization initiator in the active energy ray-curable polymer composition (BLC) of the present invention is set so that the polymerizable compound contained in the composition is polymerized and the starting point does not increase excessively. From the reason for doing, 0.5-8 mass% is preferable with respect to the total solid in a composition, and 1-5 mass% is more preferable.

(Adhesion enhancer with polarizing element)
One or more selected from the group consisting of a boronic acid compound having an ethylenically unsaturated group, an ethylenically unsaturated polymerizable group, an amino group, an amide group, and a carboxy group in order to enhance the adhesion between the polarizing element and the cured layer A compound having a functional group and a hydroxyl group, or a compound having an ethylenically unsaturated group and a blocked isocyanate group can also be used.

As for the adhesion enhancer, a boronic acid derivative is described in paragraph [0166] of JP2012-150428A, and among these, a boronic acid compound having an ethylenically unsaturated group can be preferably used.
When using the boronic acid compound which has an ethylenically unsaturated group, it is preferable that content is 0.01 to 10 weight% in solid content of the said active energy ray-curable polymer composition (BLC). More preferably, it is 05-5 weight%, and it is still more preferable that it is 0.1-3 weight%.

Next, as a compound having an ethylenically unsaturated polymerizable group and one or more functional groups selected from the group consisting of an amino group, an amide group, and a carboxy group, and a hydroxyl group, paragraphs of JP2011-221186A [ [0031] Such a compound can be preferably used.
When using a compound having one or more functional groups selected from the group consisting of an ethylenically unsaturated polymerizable group and an amino group, an amide group, and a carboxy group and a hydroxyl group, the content is the active energy ray-curable polymer composition. It is preferable that it is 0.5 to 10 weight% in solid content of a thing (BLC), and it is more preferable that it is 1 to 8 weight%.

The compound having an ethylenically unsaturated group and a blocked isocyanate group will be described. Under normal conditions, the blocked isocyanate group can protect the isocyanate group with other functional groups to suppress the reactivity of the isocyanate group, and can be deprotected by heating to regenerate the active isocyanate group. The isocyanate block body is shown.
As a commercial item of such a compound having an ethylenically unsaturated group and a blocked isocyanate group, for example, 2-[(3,5-dimethylpyrazolyl) carboxyamino] ethyl methacrylate (Karenz MOI-BP (registered trademark), Showa) Made by Denko); 2- (0-methacrylic acid)
[1 ′ Methylpropylideneamino] carboxyamino) ethyl (Karenz MOI-BM (
Registered trademark) and Showa Denko).
When using a compound having an ethylenically unsaturated group and a blocked isocyanate group, the content is preferably 0.5 to 10% by weight in the solid content of the active energy ray-curable polymer composition (BLC), More preferably, it is 1 to 8% by weight.

(solvent)
In the active energy ray-curable polymer composition (BLC) of the present invention, the main solvent is water. In the present invention, “the main solvent is water” means that the water content is the highest among all the solvents contained in the curable composition. The content of water in all the solvents is preferably 70 to 100% by weight, more preferably 80 to 100% by weight, still more preferably 90 to 100% by weight, and 95 to 100% by weight. It is particularly preferred.

[Transparent protective film]
The transparent protective film (PF1 and PF2) of the present invention is, for example, a film made of a cellulose resin such as triacetyl cellulose or diacetyl cellulose, or a film made of a polyester resin such as polyethylene terephthalate, polyethylene naphthalate, or polybutylene terephthalate. And a film made of a polycarbonate resin, a film made of a cycloolefin resin such as norbornene, and a (meth) acrylic polymer film. Among these transparent protective films, a film made of a cellulose-based resin, particularly a cellulose acylate film is preferably used.

  The surface of the transparent protective film may be subjected to any surface treatment such as anti-glare treatment, anti-reflection treatment, hard coat treatment, antistatic treatment, and antifouling treatment to form a surface treatment layer. In the surface treatment, these two or more treatments may be performed. These surface treatments are generally applied to the surface opposite to the surface to be bonded to the polarizing element. Either or both of the transparent protective film and its surface protective layer contain an ultraviolet absorber such as a benzophenone compound or a benzotriazole compound, or a plasticizer such as a phenyl phosphate compound or a phthalate compound. Also good.

The term “transparent” as used in the present invention means that the visible light transmittance is 60% or more, preferably 80% or more, and particularly preferably 90% or more.
The film thickness of the transparent protective film is preferably thin from the viewpoint of optical properties, but if it is too thin, the strength is lowered and the processability is poor. A suitable film thickness is 5 to 100 μm, preferably 10 to 80 μm, and more preferably 15 to 70 μm.
Depending on the use of the polarizing plate, an optical compensation film having an optically anisotropic layer can be used as the transparent protective film (PF2).

[Layer structure of polarizing plate with adhesive layer]
When the polarizing plate with the pressure-sensitive adhesive layer of the present invention is a single-sided polarizing plate having a transparent protective film (PF1) only on one surface of the polarizing element, the cured layer of the present invention is disposed on the surface opposite to the transparent protective film of the polarizing element. (BL1). Furthermore, you may have the cured layer (BL2) of this invention between a transparent protective film and a polarizing element.
Moreover, when the polarizing plate with an adhesive layer of this invention has a transparent protective film (PF1) and a transparent protective film (PL2) on both surfaces of a polarizing element, the surface opposite to the transparent protective film (PF1) of a polarizing element That is, the cured layer (BL1) of the present invention is provided between the transparent protective film (PF2) and the polarizing element. Furthermore, you may have the cured layer (BL2) of this invention between a transparent protective film (PF1) and a polarizing element.
In the present invention, the preferred layer constitution of the polarizing plate with the pressure-sensitive adhesive layer is shown below.

Transparent protective film (PF1) / polarizing element (P) / cured layer (BL1) / adhesive layer Transparent protective film (PF1) / polarizing element (P) / cured layer (BL1) / transparent protective film (PF2) / adhesive Layer transparent protective film (PF1) / cured layer (BL2) / polarizing element (P) / cured layer (BL1) / adhesive layer transparent protective film (PF1) / cured layer (BL2) / polarizing element (P) / cured layer (BL1) / Transparent protective film (PF2) / Adhesive layer

[Method for producing polarizing plate with pressure-sensitive adhesive layer]
Next, a method for producing the polarizing plate with the pressure-sensitive adhesive layer of the present invention will be described.
(Adhesion of polarizing element (P) and transparent protective film (PF1))
The polarizing plate of the present invention can be laminated by previously bonding a transparent protective film and a polarizing element.
The polarizing element and the transparent protective film (PF1) produced as described above can be bonded and laminated using a known adhesive. Further, as described later, the active energy ray-curable polymer composition (BLC) of the present invention functions as an adhesive, and a cured layer (BL2) is formed between the transparent protective film (PF1) and the polarizing element (P). You can also

  When bonding the polarizing element and the transparent protective film, in order to improve the adhesion between the polarizing element and the adhesive, and between the transparent protective film and the adhesive, one or both of the bonding surfaces of the polarizing element and the transparent protective film In addition, surface treatment such as corona treatment, plasma treatment, ultraviolet irradiation, and primer coating treatment may be performed in advance. Further, the transparent protective film may be saponified.

By the above, the polarizing plate by which the transparent protective film (PF1) was formed in the single side | surface of a polarizing element through the adhesive bond layer is obtained.
In the case of a single-side polarizing plate having a transparent protective film only on one surface of the polarizing element, as described above, the polarizing element and the transparent protective film are bonded and laminated using an adhesive, and the transparent protective film is applied only on one side. The single-sided polarizing plate is prepared, and then a cured layer is laminated on the surface opposite to the transparent protective film of the polarizing element of the single-sided polarizing plate.

(Lamination method of hardened layer)
The cured layer of the present invention may be formed by any method. While controlling the thickness, the curable composition of the present invention is laminated on the polarizing element, and after drying, an active energy ray is irradiated to form a cured layer. Is preferred.
Examples of a preferable method for laminating the curable composition on the polarizing element while controlling the thickness in the present invention include a coating method and a method using a pinch roll.

When forming a hardened layer by a coating method, a known method (eg, wire bar coating method, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method) can be used.
When using a coating method, it is preferable to form a cured layer (BL1) after preparing a polarizing element (P) with a transparent protective film (PF1) bonded in advance as described above.

  In the method using pinch rolls, an aqueous solution of the active energy ray-curable polymer composition (BLC) of the present invention is supplied between the polarizing element (P) and the release film and passes through the pinch rolls. By applying pressure, the thickness of the cured layer can be controlled. For this method, for example, the apparatus shown in FIG. 2 of JP2012-189968A can be used.

  In this method using pinch rolls, a transparent protective film (PF1) bonded to a polarizing element (P) is prepared in advance, and then the active energy ray of the present invention between the polarizing element and the releasable film. By supplying an aqueous solution of the curable polymer composition (BLC) and allowing the pinch roll to pass therethrough, a cured layer (BL1) with a controlled thickness can be formed. However, when the cured layer (BL1) is laminated, It is preferable from the viewpoint of productivity that the transparent protective film (PF1) and the polarizing element (P) are simultaneously bonded at the same time.

  In this case, a transparent protective film (PF1) is supplied to one surface of the polarizing element (P), a release film is supplied to the other surface, and an adhesive is provided between the transparent protective film (PF1) and the polarizing element. By supplying the composition, supplying an aqueous solution of the active energy ray-curable polymer composition (BLC) of the present invention between the releasable film and the polarizing element and passing the pinch roll, a transparent protective film ( The bonding of PF1) and the polarizer (P) and the formation of the cured layer (BL1) of the present invention can be performed simultaneously. Thereafter, a single-side polarizing plate having a transparent protective film (PF1) only on one side of the polarizing element by peeling off the release film and having the cured layer (BL1) of the present invention on the other side of the polarizing element. Can be produced.

The cured layer is formed by irradiating active energy rays after drying, and the irradiation of active energy rays can be performed at any stage before or after the release of the releasable film.
Moreover, it can also be set as the polarizing plate which uses a transparent protective film (PF2) as a releasable film, does not peel this film after active energy ray irradiation, and has a transparent protective film on both surfaces of a polarizing element. A polarizing plate having a transparent protective film on both surfaces of the polarizing element is also a preferred embodiment of the present invention.

In the present invention, radiation, gamma rays, alpha rays, electron beams, ultraviolet rays and the like are used as active energy rays for curing the cured layer. Among these methods, a method of adding a polymerization initiator that generates radicals using ultraviolet rays and curing with ultraviolet rays is particularly preferable.
In the case of ultraviolet irradiation, ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arcs, xenon arcs, metal halide lamps, ultraviolet rays emitted from light beams such as LEDs, and the like can be used. Moreover, in order to accelerate | stimulate hardening reaction, temperature can also be raised at the time of hardening, 25-100 degreeC is preferable, More preferably, it is 30-80 degreeC, Most preferably, it is 40-70 degreeC.

(Adhesive layer)
In this invention, it has an adhesive layer containing an antistatic agent. Examples of the pressure-sensitive adhesive include acrylic, vinyl alcohol, silicon, polyester, polyurethane, and polyether types. Moreover, the active energy ray polymeric compound may be included.
Examples of the antistatic agent include ionic conductive agents composed of alkali metal salts, ionic liquids, surfactants, conductive polymers, metal oxides, carbon black, and carbon nanomaterials. Among these, from the viewpoint of permanent chargeability and no coloration, an ionic conductive agent and / or ionic liquid made of an alkali metal is preferably used.

In the present invention, the antistatic agent is preferably an ionic compound containing a fluorine-containing anion. Examples of the ionic compound containing a fluorinated anion include an ionic compound comprising an organic cation and a fluorinated anion, and an ionic compound comprising an alkali metal cation and a fluorinated anion. An ionic compound comprising an organic cation and a fluorine-containing anion is preferred. Fluorine-containing anions include BF ₄ ⁻ , PF ₆ ⁻ , CF ₃ COO ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (SO ₂ F) ₂ N ⁻ , C ₄ F ₉ SO ₃ ⁻ In particular, CF ₃ COO ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (SO ₂ F) ₂ N ⁻ , or C ₄ F ₉ SO ₃ ⁻ is particularly preferable. preferable.

  Examples of the organic cation include a pyridinium cation, a piperidinium cation, a pyrrolidinium cation, a cation having a pyrroline ring, a cation having a pyrrole ring, an imidazolium cation, and a tetraalkylammonium cation. Specifically, 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, 1-hexyl-3 -Pyridinium cations such as methylpyridinium cation and 1-hexyl-4-methylpyridinium cation; 1-propylpiperidinium cation, 1-pentylpiperidinium cation, 1,1-dimethylpiperidinium cation, 1-methyl- 1-ethylpiperidinium cation, 1-methyl-1-propylpiperidinium cation, 1-methyl-1-butylpiperidinium cation, 1-methyl-1-pentylpiperidinium cation, 1-methyl-1- Piper such as hexyl piperidinium cation Lidinium cation; 1,1-dimethylpyrrolidinium cation, 1-ethyl-1-methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidinium cation, 1-methyl-1-butylpyrrolidinium cation, 1-methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium cation, 1-ethyl-1-propylpyrrolidinium cation, 1 -Pyrrolidinium cations such as ethyl-1-butylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation, 1-ethyl-1-hexylpyrrolidinium cation; 2-methyl-1-pyrroline cation A cation having a pyrroline ring such as 1-ethyl-2-phenylindole cation Cation having a pyrrole ring such as 1,2-dimethylindole cation, 1-ethylcarbazole cation; 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation Imidazolium cations such as 1-butyl-3-methylimidazolium cation and 1-hexyl-3-methylimidazolium cation; tetramethylammonium cation, tetraethylammonium cation, tetrabutylammonium cation, tetrahexylammonium cation, triethylmethyl Examples thereof include tetraalkylammonium cations such as ammonium cation, tributylethylammonium cation, and trimethyldecylammonium cation.

Specific examples of the ionic compound comprising an organic cation and a fluorine-containing anion include 1-butyl-4-methylpyridinium tetrafluoroborate, 1-butyl-4-methylpyridinium hexafluorophosphate, and 1-butyl-3-methylpyridinium bis. (Trifluoromethanesulfonyl) imide, 1-butyl-1-methylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-butyl-1-methylpyrrolidinium tetrafluoroborate; 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, 1-butyl-2,3-dimethylimidazolium hexafluorophosphate 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-methyl-3-octylimidazolium trifluoromethanesulfonate, 1,2,3-trimethylimidazolium trifluoromethanesulfonate, 1-hexyl-3-methylimidazole Examples include lithium trifluoromethanesulfonate; tetraethylammonium trifluoroacetate, tetrahexylammonium tetrafluoroborate and the like.

On the other hand, examples of the alkali metal cation include K ⁺ , Li ⁺ , and Na ⁺ . Among ionic compounds composed of alkali metal cations and fluorine-containing anions, LiBF ₄ , LiPF ₆ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li (SO ₂ F) ₂ N, LiC ₄ F ₉ SO ₃ Lithium salts such as are preferable because of their good antistatic performance.

  The blending amount of the antistatic agent in the pressure-sensitive adhesive composition used in the present invention is 0.01 to 10% by weight, preferably 0.1 to 8% by weight, based on the total solid content of the pressure-sensitive adhesive composition. is there. If it is less than 0.01% by mass, sufficient antistatic performance cannot be obtained, and if it is more than 10% by weight, durability is lowered by bleeding of the antistatic agent, which is not preferable.

  It is preferable to provide a curing step after applying the adhesive. This curing step is a step of curing the pressure-sensitive adhesive. In addition, the adhesive layer formed between the polarizing element and the protective film is further cured and stabilized. This curing step is performed under a temperature environment of 15 to 85 ° C, preferably 20 to 50 ° C, more preferably 20 to 30 ° C. The period is, for example, 1 to 90 days. However, if this curing period is long, the productivity is deteriorated, so that it is preferably about 1 to 30 days, and more preferably about 1 to 7 days. Moreover, you may cut the polarizing plate with an adhesive layer of this invention according to the magnitude | size of the liquid crystal panel used together. This cutting process may be performed after the polarizing plate is bonded to the liquid crystal panel.

[Liquid Crystal Display]
The liquid crystal display device of the present invention includes a liquid crystal cell and the polarizing plate with the pressure-sensitive adhesive layer of the present invention disposed in at least one of the liquid crystal cells, and is bonded to the liquid crystal cell by the pressure-sensitive adhesive layer of the polarizing plate. It is characterized by being.

(General liquid crystal display device configuration)
The liquid crystal display device includes a liquid crystal cell having a liquid crystal supported between two electrode substrates, two polarizing plates disposed on both sides thereof, and, if necessary, between the liquid crystal cell and the polarizing plate. At least one optical compensation film is arranged.
The liquid crystal layer of the liquid crystal cell is usually formed by sealing liquid crystal in a space formed by sandwiching a spacer between two substrates. The transparent electrode layer is formed on the substrate as a transparent film containing a conductive substance. The liquid crystal cell may further be provided with a gas barrier layer, a hard coat layer, or an undercoat layer (undercoat layer) (used for adhesion of the transparent electrode layer). These layers are usually provided on the substrate. The substrate of the liquid crystal cell generally has a thickness of 50 μm to 2 mm.

(Types of liquid crystal display devices)
The film of the present invention can be used for liquid crystal cells in various display modes. TN (Tw
istted Nematic), IPS (In-Plane Switching), FL
C (Ferroelectric Liquid Crystal), AFLC (Anti
-Ferroelectric Liquid Crystal), OCB (Optically Compensatory Bend), STN (Super Twisted Nematic), VA (Vertically Aligned), ECB (Elect
Various display modes such as a realistic controlled birefringence (HAN) and a hybrid aligned nematic (HAN) have been proposed. In addition, a display mode in which the above display mode is oriented and divided has been proposed. The polarizing plate of the present invention is effective in any display mode liquid crystal display device. In addition, any of a transmissive type, a reflective type, and a transflective liquid crystal display device can be used.

  When the polarizing plate of the present invention is bonded to both surfaces of the IPS mode liquid crystal cell, light leakage when viewed from an oblique direction during black display is particularly preferable.

The present invention will be specifically described below based on examples. The materials, reagents, substance amounts and ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the present invention is not limited to the following examples.
First, the present invention will be described by taking as an example the following layer structure having a transparent protective film only on one side of a polarizing element.
Transparent protective film (PF1) / Polarizing element (P) / Hardened layer (BL1) / Adhesive layer

(Preparation of polarizing element)
A PVA film having an average polymerization degree of 2400 and a saponification degree of 99.9 mol% and a film thickness of 40 μm was immersed in warm water at 25 ° C. for 120 seconds to swell. Next, the PVA film was dyed while immersed in an aqueous solution of 0.6% by weight of iodine / potassium iodide (weight ratio = 2/3) and stretched 2.1 times. Thereafter, the film was stretched in an acidic bath containing boric acid and potassium iodide at 60 ° C., washed with water and dried to prepare a polarizing element having a film thickness of 15 μm.

(Preparation of polarizing plate adhesive)
A modified PVA resin containing an acetoacetyl group (manufactured by Nippon Synthetic Chemical Co., Ltd .: Gohsenx Z-410) was dissolved in water to prepare an aqueous solution A adjusted to a solid content concentration of 3%. Subsequently, maleic acid was added so that it might become 0.5 weight% with respect to the said aqueous solution A, and the glyoxal was added as a crosslinking agent after that. The addition amount of glyoxal was set to 5 by weight when the weight of Z-410 was 100. Sodium hydroxide was added to this aqueous solution to adjust the pH to 2.5 to obtain a polarizing plate adhesive.

(Saponification of cellulose acylate film)
A commercially available cellulose acylate film TD60 (manufactured by Fuji Film Co., Ltd .: film thickness 60 μm) was immersed in a 1.5 mol / L NaOH aqueous solution (saponification solution) maintained at 55 ° C. for 2 minutes, and then the film was washed with water. Thereafter, the film was immersed in a 0.05 mol / L sulfuric acid aqueous solution at 25 ° C. for 30 seconds, and then a washing bath was passed under running water for 30 seconds to make the film neutral. Then, draining with an air knife was repeated three times, and after dropping the water, the film was retained in a drying zone at 70 ° C. for 15 seconds and dried to produce a saponified film.

(Production of single-sided polarizing plate)
The polarizing plate adhesive prepared above is applied to one side of the saponified cellulose acylate film prepared above so that the thickness after drying is 80 nm, and the polarizing element 1 is applied to the polarizing element 1 via the adhesive layer. After bonding using a combination machine, the film was dried at 60 ° C. for 10 minutes to obtain a single-side polarizing plate.

[Preparation of active energy ray-curable polymer composition for forming cured layer]
Hereinafter, a method for preparing an aqueous liquid of an active energy ray-curable polymer composition for forming a cured layer (hereinafter also referred to as a composition for forming a cured layer) will be described. In consideration of coating properties and the like, the solid content concentration and the pH of the solution were adjusted as necessary.
Prepared as shown below.

(Composition of cured layer forming composition BLC-1)
UCECOAT 7571 (35% by weight aqueous solution) 242.9 parts by mass (solid content 85.0 parts by mass)
A-TMPT 12.0 parts by mass Irgacure 2959 3.0 parts by mass

Purified water was added to the above blend so that the solid content concentration was 35% by weight, and after mixing and irradiation with ultrasonic waves, a cured layer forming composition (BLC-1) was prepared through a filter having a pore size of 5 μm. .
The cured layer forming compositions BLC-2 to BLC-8 were prepared in the same manner as the cured layer forming composition BLC-1. The composition ratios are shown in Table 1. Table 1 shows the mass ratio of the solid content of each component. Here, the solid content is a composition excluding a solvent (including water contained in UCECOAT 7571 in BLC-1).

The materials used in Table 1 are shown below.
UCECOAT 7571: Water-dispersible polyurethane (meth) acrylate (UV Curable Waterbone Resin) [manufactured by Allnex Co., Ltd.] Solid content concentration 35% by weight, number average molecular weight Mn = 10000, having a polyurethane structure composed of polyol and polyisocyanate, self Emulsified emulsion, tack-free after drying ・ UCECOAT 7849: Water-dispersible polyurethane (meth) acrylate (UV Curable Waterbone Resin) [manufactured by Allnex Co., Ltd.] Solid content concentration 35% by weight, number average molecular weight Mn = 10000, from polyol and polyisocyanate Self-emulsifying emulsion with polyurethane structure, tack-free after drying

A-TMPT: trimethylolpropane triacrylate [manufactured by Shin-Nakamura Chemical Co., Ltd.] Viscosity: 110 (mPa · s / 25 ° C.), acrylic equivalent: 98.7
-Biscoat # 360: Trimethylolpropane EO 3.5 mol adduct triacrylate [manufactured by Osaka Organic Chemical Industry Co., Ltd.] Viscosity: 65 (mPa · s / 25 ° C), acrylic equivalent: 147.7
A-DCP: Tricyclodecane dimethanol diacrylate [manufactured by Shin-Nakamura Chemical Co., Ltd.] Viscosity: 120 (mPa · s / 25 ° C.), acrylic equivalent: 152.0
BS-710: pentaerythritol polyacrylate (main component is pentaerythritol tetraacrylate) [Arakawa Chemical Industries, Ltd.] Viscosity: 500 (mPa · s / 25 ° C.)
, Acrylic equivalent: 88.0

BS-730: Ditrimethylolpropane tetraacrylate [Arakawa Chemical Industries, Ltd.] Viscosity: 560 (mPa · s / 25 ° C.), acrylic equivalent: 116.8
・ Irgacure 2959: Photopolymerization initiator [manufactured by BASF]
・ Irgacure 1173: Photopolymerization initiator [manufactured by BASF]
-PSA1: See below (preparation of adhesive composition)-PSA2: See below (preparation of adhesive composition)

(Production of single-sided polarizing plate with hardened layer)
Using a bar coater on the polarizer of the single-sided polarizing plate produced above, a composition for forming a cured layer (
BLC-1) was applied so that the film thickness after drying was 2.5 μm, and then dried at 60 ° C. for 10 minutes. Thereafter, using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) having an output of 160 W / cm at atmospheric pressure, the coating layer is cured by irradiating with ultraviolet rays having an illuminance of 400 mW / cm ² and an irradiation amount of 500 mJ / cm ^2. A single-sided polarizing plate with a hardened layer was produced. (Polarizing plate 1)

(Preparation of polarizing plates 2 to 14)
Single-sided polarizing plates 2 to 14 were prepared in the same manner as polarizing plate 1 except that the type of the cured layer forming composition and the thickness of the cured layer were changed as shown in Table 1. Moreover, the single-sided polarizing plates 13 and 14 did not laminate | stack a hardened layer on a polarizing element.

Next, a polarizing plate with an adhesive layer will be described.
(Preparation of adhesive composition)
Ion comprising 1-butyl-3-methylpyridinium cation, which is an ionic compound comprising an organic cation and a fluorine-containing anion, and an (CF ₃ SO ₂ ) ₂ N anion as an antistatic agent according to Example 12 of WO 2010/064551 A pressure-sensitive adhesive composition (PSA1) containing a liquid was prepared.
Similarly, a pressure-sensitive adhesive composition (PSA2) containing no ionic liquid was prepared according to Comparative Example 11.

(Preparation of polarizing plate 1 with adhesive layer)
The pressure-sensitive adhesive layer was applied onto the peeled PET release film using a doctor blade and dried at 90 ° C. for 3 minutes. After drying, it was bonded to the cured layer side (the side on which the protective film was not laminated) of the above polarizing plate 1 and allowed to stand for 7 days at 23 ° C. and 65% humidity to obtain a polarizing plate 1 with an adhesive layer. . The thickness of the pressure-sensitive adhesive layer was 15 μm.

(Preparation of polarizing plates 2 to 14 with an adhesive layer)
The polarizing plate 1 with an adhesive layer except having changed the kind of composition for hardening layer formation, the film thickness of a cured layer, and the kind of adhesive composition with respect to the polarizing plate 1 with an adhesive layer to what was shown in Table 2. In the same manner, polarizing plates 2 to 14 with an adhesive layer were obtained.
In addition, the polarizing plates 13 and 14 with an adhesive layer do not have a hardening layer, but the adhesive layer is laminated | stacked directly on the polarizing element.

(Wet heat durability test)
The pressure-sensitive adhesive polarizing plate produced above is cut into a size of 35 mm × 35 mm, the release film is peeled off, and bonded to one side of a 50 mm × 50 mm, 1 mm thick glass plate using a laminator roll, then 5 ° C. A test piece was obtained by holding the sample in an autoclave for 20 minutes under atmospheric pressure. Two test pieces were prepared for each level.
The prepared test piece was put in for 500 hours under conditions of a temperature of 60 ° C. and a humidity of 90% RH. The polarization degree of the polarizing film (test piece) before and after the injection was measured using V7100 manufactured by JASCO Corporation, and the change in polarization degree ΔPE was calculated according to the following formula.

Change amount of polarization ΔPE = (degree of polarization before throwing) − (degree of polarization after throwing)
The degree of polarization was calculated according to the following method.
The transmittance (Tp) when the produced two polarizing plates are superposed in parallel with the absorption axis and the transmissivity (Tc ′) when the absorption axes are superposed with each other perpendicular to each other are measured. (PE) was calculated.
Polarization degree PE = ((Tp−Tc ′) / (Tp + Tc ′)) ^0.5 × 100 [%] In the present invention, ΔPE after the wet heat durability test needs to be 1.0% or less. .50% or less is preferable, 0.10% or less is more preferable, and 0.02% or less is particularly preferable.

(Measurement of surface resistance)
After peeling off the PET release film from the adhesive polarizing plate, the surface resistance value of the adhesive layer surface was measured using a super insulation resistance / microammeter TR8601 (manufactured by Advantest Co., Ltd.), and the surface resistance value (Ω / □) ) In common logarithm (log SR). The lower the log SR, the better the antistatic property. In the present invention, it should be 14.0 or less, and more preferably 13.0 or less.

From the results shown in Table 1, the following is clear.
1. Adhesive containing an antistatic agent on a cured layer of a single-sided polarizing plate having a cured layer formed from an aqueous solution of an active energy ray-curable composition mainly composed of a polymer compound having an ethylenically unsaturated group of the present invention The pressure-sensitive adhesive polarizing plate in which the adhesive layer is laminated does not have a decrease in the degree of polarization after the wet heat durability test and has good wet heat resistance.
2. When the active energy ray-curable composition is composed mainly of a polymer compound having an ethylenically unsaturated group and further contains a polyfunctional (meth) acrylate compound, the degree of polarization after the wet heat durability test is less and the heat and heat resistance is further improved. The property is also good.

Next, an example in which an adhesion reinforcing agent is used in the composition for forming a cured layer is shown.
(Preparation of composition BLC-9 for hardening layer formation)
A cured layer forming composition (BLC-9) was prepared in the same manner as the cured layer forming composition (BLC-1) except that the composition of the solid content was changed as shown below.

(Composition of solid content of composition BLC-9 for forming a cured layer)
UCECOAT 7571 84.0 parts by weight A-TMP 12.0 parts by weight 4-vinylphenylboronic acid 1.0 part by weight Irgacure 2959 3.0 parts by weight

(Preparation of composition BLC-9 for hardening layer formation)
A cured layer forming composition (BLC-10) was prepared in the same manner as in the cured layer forming composition (BLC-9) except that 4-vinylphenylboronic acid was replaced with the following boronic acid compound A.

The materials newly used in (BLC-9) and (BLC10) are shown below.
・ 4-Vinylphenylboronic acid: Reagent [manufactured by Tokyo Chemical Industry Co., Ltd.]
Boronic acid compound A: Refer to the following chemical formula

(Preparation of polarizing plates 15 and 16 with adhesive and evaluation of polarizing plates 15 and 16)
Polarizing plates 15 and 16 with pressure-sensitive adhesive were prepared in the same manner except that the composition for forming a cured layer was changed to (BLC-9) and (BLC-10) for the polarizing plate 1 with pressure-sensitive adhesive layer.
Moreover, except having replaced with the adhesive polarizing plate 22 or the polarizing plate 23 similarly to the polarizing plate 1 with an adhesive, the polarizing plates 15 and 16 with an adhesive were evaluated similarly. The results are shown in Table 2.

  From the results shown in Table 2, it is clear that even when a boronic acid compound is used as the adhesion enhancer in the composition for forming a cured layer, the degree of polarization does not decrease after the wet heat durability test and the wet heat resistance is good.

Next, the present invention will be described by taking the following two layer structures having transparent protective films on both surfaces of the polarizing element as examples.
Transparent protective film (PF1) / polarizing element (P) / cured layer (BL1) / transparent protective film (PF2) / adhesive layer transparent protective film (PF1) / cured layer (BL2) / polarizing element (P) / cured layer (BL1) / Transparent protective film (PF2) / Adhesive layer

(Preparation of cellulose acylate film containing no UV absorber)
In the same manner except that the flow rate was adjusted so that the thickness of the mainstream became 14 μm with reference to paragraphs [0160] to [0163] of JP2012-177894A, a cellulose reed containing no UV absorber having a thickness of 20 μm. A rate film (CA-1) was produced.

(Saponification of cellulose acylate film CA-1)
A saponified cellulose acylate film (CA-1) was produced in the same manner as the saponification of the cellulose acylate film TD60 described above.
(Production of single-sided polarizing plate)
A single-sided polarizing plate was produced in the same manner as in Example 1.

(Preparation of polarizing plate 21)
A polarizing element was produced in the same manner as in Example 1.
A polarizing plate adhesive is applied to one side of a saponified cellulose acylate film TD60 so that the thickness after drying becomes 80 nm. At the same time, the curable composition (CA-1) is also applied to the saponified cellulose acylate film (CA-1). While applying BLC-6) so that the thickness after drying becomes 2.5 μm, using a roll laminator, the polarizing plate adhesive and the curable composition (BLC-6) are used for the polarizing element. Saponified cellulose acylate film TD60 and saponified cellulose acylate film (CA-1) were bonded to both sides.

After pasting, it is dried at 65 ° C. for 10 minutes, and using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) having an output of 160 W / cm at atmospheric pressure, an ultraviolet ray having an illuminance of 400 mW / cm ² and an irradiation amount of 1000 mJ / cm ² Was applied from the cellulose acylate film (CA-1) side subjected to saponification treatment to cure the coating layer, and a polarizing plate 21 with a cured layer was produced.

(Preparation of polarizing plate 22)
The polarizing plate 21 was coated with a curable composition (BLC-6) on one side of a saponified cellulose acylate film TD60 in place of the polarizing plate adhesive so that the thickness after drying was 1 μm. A polarizing plate 22 was produced in the same manner as the polarizing plate 21.

(Preparation of polarizing plate 23)
A polarizing plate adhesive is applied to one side of the saponified cellulose acylate film (CA-1) on the polarizing plate 21 instead of the curable composition (BLC-6) so that the thickness after drying becomes 80 nm. A polarizing plate 23 was produced in the same manner as the polarizing plate 21 except that.

(Preparation of polarizing plate with adhesive layer 21)
The pressure-sensitive adhesive layer was applied onto the peeled PET release film using a doctor blade and dried at 90 ° C. for 3 minutes. After drying, it was bonded to the cellulose acylate film (CA-1) side of the polarizing plate 21 and allowed to stand for 7 days under the conditions of 23 ° C. and 65% humidity to obtain a polarizing plate 21 with an adhesive layer. The thickness of the pressure-sensitive adhesive layer was 15 μm.

(Preparation of polarizing plates 22 and 23 with adhesive layer)
A polarizing plate 22 with an adhesive and a polarizing plate 23 with an adhesive were prepared in the same manner except that the polarizing plate 22 or the polarizing plate 23 was used instead of the polarizing plate 21 with an adhesive layer.

(Evaluation of polarizing plates with adhesive 21 to 23)
The polarizing plates 21 to 23 with pressure-sensitive adhesive were evaluated in the same manner as the polarizing plate 1 with pressure-sensitive adhesive layer. The results are shown in Table 2.

From the results shown in Table 3, the following is clear.
1. Even in a polarizing plate with an adhesive having a transparent protective film on both sides and an adhesive layer containing an antistatic agent, the cured layer of the present invention is laminated between the transparent protective film and the polarizing element on the adhesive layer side. As a result, the degree of polarization after the wet heat durability test is eliminated and the wet heat durability is good.

Claims (14)

A transparent protective film (PF1) is provided on one surface of a polarizing element (P) formed by adsorbing and orienting iodine on a polyvinyl alcohol resin layer, and a cured layer (BL1) and an antistatic agent-containing pressure-sensitive adhesive are provided on the other surface. A polarizing plate with an adhesive layer provided with a layer,
The cured layer (BL1) has an average film thickness of 0.5 to 10 μm, and is formed from an aqueous solution of an active energy ray-curable polymer composition whose main component is a polymer compound having an ethylenically unsaturated group. A polarizing plate with a pressure-sensitive adhesive layer. 2. The content of the polymer compound having an ethylenically unsaturated group in the solid content in the aqueous solution of the active energy ray-curable polymer composition is 50 to 99% by weight. Polarizing plate with an adhesive layer. 3. The adhesive layer according to claim 1, wherein the aqueous solution of the active energy ray-curable polymer composition is a self-emulsifying emulsion of a polymer composition having an ethylenically unsaturated group. Polarizer. The polarizing plate with an adhesive layer according to claim 1, wherein the polymer compound having an ethylenically unsaturated group is water-dispersible polyurethane (meth) acrylate. The number average molecular weight of the high molecular compound which has the said ethylenically unsaturated group is 5000-100000, The polarizing plate with an adhesive layer in any one of Claims 1-4 characterized by the above-mentioned. The active energy ray-curable polymer composition further contains a polyfunctional (meth) acrylate compound, and the content of the polyfunctional (meth) acrylate compound is in the solid content in the aqueous solution of the active energy ray-curable polymer composition. The polarizing plate with the pressure-sensitive adhesive layer according to claim 1, wherein the polarizing plate has a pressure-sensitive adhesive layer content of 1 to 40% by weight. The polarizing plate with the pressure-sensitive adhesive layer according to claim 1, wherein the active energy ray-curable polymer composition further contains a radical photopolymerization initiator. The pressure-sensitive adhesive layer is provided on the opposite surface of the cured layer (BL1) of the polarizing plate from the polarizing element (P), directly or via a transparent protective film (PF2). The polarizing plate with an adhesive layer in any one of -7. The polarizing plate with the pressure-sensitive adhesive layer according to claim 8, wherein the transparent protective film (PF2) is a cellulose acylate film having a thickness of 10 to 50 µm. The polarizing plate with the pressure-sensitive adhesive layer according to claim 1, wherein the pressure-sensitive adhesive layer contains an ionic antistatic agent. Between the transparent protective film (PF1) and the polarizing element (P), a cured layer (BL2) having a film thickness of 0.5 to 10 μm and the same composition as the cured layer (BL1) is provided. The polarizing plate with an adhesive layer in any one of Claims 1-10 characterized by the above-mentioned. A liquid crystal display device comprising the polarizing plate according to claim 1 bonded to at least one side of a liquid crystal cell. The active energy ray-curable polymer composition used for producing the polarizing plate according to claim 1, wherein the polymer compound having an ethylenically unsaturated group is an aqueous solution when the aqueous solution is used. An active energy ray-curable polymer composition comprising 50 to 99% by weight in a solid content and 1 to 40% by weight of a polyfunctional (meth) acrylate compound in an aqueous solution solid content. A step of laminating a transparent protective film (PF1) only on one side of a polarizing element (P) formed by adsorbing and orienting iodine on a polyvinyl alcohol resin layer,
A step of applying an aqueous solution of an active energy ray-curable polymer composition in which the main solvent is water on the polarizing element of the single-side polarizing plate;
A step of drying the applied aqueous solution of the active energy ray-curable polymer composition, irradiating active energy rays under atmospheric pressure and normal atmosphere to form a cured layer, and an antistatic agent-containing pressure-sensitive adhesive layer The manufacturing method of the polarizing plate with an adhesive layer in any one of Claims 1-11 characterized by including the process provided.