JP7036880B2 - A polarizing plate with a pressure-sensitive adhesive layer and a method for manufacturing the same, an active energy ray-curable polymer composition used for the manufacture thereof, and a liquid crystal display device. - Google Patents

Description

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

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

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

International Publication No. 2007/034533 Pamphlet Japanese Unexamined Patent Publication No. 2014-048497

In view of the above situation, the problem of the present invention, that is, the problem to be solved by the present invention, is to have a polarizing plate protective film on only one surface of the polarizing element and to ionize on the other surface of the polarizing element. A thin polarizing plate with a pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer containing an antistatic agent such as a property liquid, but with a pressure-resistant layer having good optical characteristics even after a wet-heat durability test. Is to provide a board.

As a result of diligent studies by the present inventors, it is presumed that the deterioration of the optical properties after the moist heat durability test is due to the movement of the antistatic agent in the pressure-sensitive agent and the iodine complex in the polarizing element using water as a medium, and it is presumed to be polyfunctional (meth). ) An ultraviolet curable composition in which an acrylate monomer and a photopolymerization initiator are dissolved in an organic solvent is applied onto the polarizing element of a single-sided polarizing plate, dried, and then UV-irradiated 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 and heat durability of the polarizing plate is improved.

However, in the polarizing plate manufacturing process using a polarizing element produced by adsorbing and orienting iodine on a polyvinyl alcohol-based resin layer, an organic solvent is not usually used, so that it can be used for explosion-proofing, recovery of the organic solvent after drying, and the like. It is not an organic solvent specification. Therefore, in order to introduce the above method into the polarizing plate manufacturing process, the manufacturing equipment must be modified to the organic solvent specification, which imposes a significant burden on the polarizing plate manufacturer. In addition, a new problem has emerged that the use of an organic solvent (VOC) increases the burden on the environment.
In addition, when using a polyfunctional (meth) acrylate monomer, if UV irradiation is performed in the atmosphere without using a nitrogen purge facility, the surface of the cured layer becomes unreacted due to the inhibition of curing by oxygen, and when handled as it is, the monomer is placed on the handling roll. Problems such as adhesion occur. Therefore, a new problem has arisen that requires the introduction of nitrogen purging equipment.

In view of the above situation, the problem of the present invention, that is, the problem to be solved by the present invention, is to have a polarizing plate protective film on only one surface of the polarizing element and to use an ionic liquid or the like on the other surface. A thin polarizing plate with a pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer containing an antistatic agent, but a polarizing plate with a pressure-sensitive adhesive layer having good optical characteristics even after a wet-heat durability test. The present invention is to provide a polarizing plate by a method having a small modification load in the polarizing plate manufacturing process and a small environmental load, and also to provide 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 manufacturing such a polarizing plate, and another object of the present invention is a liquid crystal display having moisture resistance and heat durability with improved display characteristics after a wet and heat durability test. It is to provide a display device.

As a result of diligent studies, the present inventors have a transparent protective film on only one surface of the polarizing element formed by adsorbing and orienting iodine on a polyvinyl alcohol-based resin, and the surface opposite to the transparent protective film of the polarizing element. An aqueous active energy ray-curable composition containing a polymer compound having an ethylenically unsaturated group as a main component in a polarizing plate with a pressure-sensitive adhesive layer in which a pressure-sensitive adhesive layer containing an antioxidant such as an ionic compound is laminated. It has been found that deterioration of optical characteristics after a moisture resistance test can be suppressed by installing a cured layer formed by the above and having a specific film thickness between the polarizing element and the pressure-sensitive adhesive layer, and the present invention has been completed.

Further, even in a polarizing plate having a transparent protective film on both sides of the polarizing element, the cured layer of the present invention is laminated between the polarizing element and the transparent protective film (PF2) on the liquid crystal cell side to improve the moist heat durability of the polarizing plate. He found out what he could do and came to the completion of the second invention. In particular, as described above, it is presumed that the deterioration of the optical properties after the moist heat durability test, which is the subject of the present invention, is generated by using water as a medium, and in the second aspect of the invention, as a transparent protective film (PF2) on the liquid crystal cell side. The effect is seen when the cellulose acylate-based film having a relatively high moisture permeability and a thickness of 10 to 50 μm is used.
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 on a polyvinyl alcohol-based resin layer, and a cured layer (BL1) and an antistatic agent are provided on the other surface. A polarizing plate with a pressure-sensitive adhesive layer provided with a 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 containing a polymer compound having an ethylenically unsaturated group as a main component. A polarizing plate with an adhesive layer, which is characterized by being a polymer.
(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). ). The polarizing plate with an adhesive layer.

(3) The method according to (1) or (2), wherein the aqueous solution of the active energy ray-curable polymer composition is a self-emulsifying emulsion of the polymer composition having an ethylenically unsaturated group. A 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 a 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 5000 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. The polarizing plate with an adhesive layer according to any one of (1) to (5), which is 1 to 40% by weight of the solid content.
(7) The polarizing plate with an adhesive layer according to any one of (1) to (6), wherein the active energy ray-curable polymer composition further contains a photoradical polymerization initiator.
(8) The pressure-sensitive adhesive layer is provided directly on the surface of the cured layer (BL1) of the polarizing plate opposite to the polarizing element (P) or via a transparent protective film (PF2). 1) The polarizing plate with an adhesive layer according to any one of (7).
(9) The polarizing plate with an adhesive layer according to (8), wherein the transparent protective film (PF2) is a cellulose acylate-based film having a thickness of 10 to 50 μm.
(10) The polarizing plate with a 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).
(12) A liquid crystal display device in which the polarizing plate according to any one of (1) to (11) is attached to at least one side of a liquid crystal cell.
(13) An active energy ray-curable polymer composition used for producing the polarizing plate according to any one of (1) to (11), which has an ethylenically unsaturated group when used as an aqueous solution. An active energy ray-curable polymer composition comprising 50 to 99% by weight of a molecular compound in the solid content of an aqueous solution and 1 to 40% by weight of a polyfunctional (meth) acrylate compound in the solid content of an aqueous solution. ..

(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-based resin layer to form a single-sided polarizing plate.
A step of applying an aqueous solution of an active energy ray-curable polymer composition in which the main solvent is water onto the polarizing element of the single-sided polarizing plate.
After drying the applied aqueous solution of the active energy ray-curable polymer composition, the step of irradiating the applied active energy ray under atmospheric pressure and normal atmosphere to form a cured layer, and the antistatic agent-containing pressure-sensitive adhesive layer are performed. The method for manufacturing a polarizing plate with an adhesive layer according to any one of (1) to (11), which comprises a step of providing the polymer.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a polarizing plate with an adhesive layer, which is thin, has excellent antistatic properties, and has moisture resistance and heat durability with little change in optical characteristics (decrease in polarization degree, etc.) after a moisture and heat durability test. By using the polarizing plate with an adhesive layer of the present invention, it is possible to provide a display device in which light leakage is suppressed after a lapse of time in a high temperature and high humidity environment.

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

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

The method for manufacturing the polarizing element is not particularly limited, but a method of feeding out a polyvinyl alcohol-based resin film wound in a roll shape in advance and performing stretching, dyeing, cross-linking, etc., or a polyvinyl alcohol-based resin and a resin base material for stretching. A typical method includes a step of producing a laminated body of the above and stretching the laminated body in the state of the laminated body. In the present invention, any of these methods can be used. Methods for manufacturing 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. The thickness of the polarizing element of the present invention is preferably 3 to 35 μm, more preferably 4 to 30 μm, and even more preferably 5 to 25 μm.

[Hardened layer]
The cured layer (BL1) (BL2) of the present invention 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 and whose main solvent is water. In the present invention, the main component of the polymer compound having an ethylenically unsaturated group is that the content of the polymer compound having an ethylenically unsaturated group is the largest in the aqueous solution solid content of the curable polymer composition. Means that. The polymer compound having an ethylenically unsaturated group may be one kind or two or more kinds. When there are two or more types of polymer compounds having an ethylenically unsaturated group, the "content of the polymer compound having an ethylenically unsaturated group" is the content of all the polymer compounds having an ethylenically unsaturated group (compound). It means the total of 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. More preferred. By suppressing the content within this range, it is possible to suppress changes in the optical characteristics of the polarizing plate having the cured layer laminated after the moisture resistance test.
In the configuration of the polarizing plate having two layers of the cured layer (BL1) and (BL2), the cured layer (BL1) and (BL2) may be formed from the same active energy ray-curable polymer composition. Although preferable from the viewpoint of productivity, it may be formed from different active energy ray-curable polymer compositions.

The effect of improving the wet heat durability is that at least a part of the polymer compound having an ethylenically unsaturated group in the active energy ray-curable polymer composition of the present invention is a polymer emulsion having an ethylenically unsaturated group. Preferred in terms of points. Although the present inventors speculate that a hydrophobic structure is preferable for improving the moist heat durability, the emulsion-type polymer compound has a hydrophobic structure and is preferable from the viewpoint of improving the moist heat durability.
Emulsion type polymer compounds include forced emulsification type that uses a surfactant as an emulsifier and self-emulsification type that introduces a hydrophilic group into the compound. Self-emulsification type polymer emulsion is a surfactant after drying. 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 a (meth) acrylate group, which can be preferably used as an active energy ray-curable polymer compound in the present invention, will be described. do.

(Water-dispersible polyurethane (meth) acrylate)
Generally, polyurethane is a reaction product of a polyol and a polyisocyanate, but by using a polyol having a functional group (hydrophilic group) having ionic or nonionic hydrophilic properties in at least a part of the polyol, the polyurethane is hydrophilic. The group can be introduced. Preferred examples of such polyols have one or more acidic groups that can be converted to an anionic salt groups such as carboxylates and sulfonates, or anionic bases such as carboxylic acid groups or sulfonic acid groups. Examples include polyols. Specifically, α, α-dimethylolalkanoic acid, for example, 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 polyurethane by using a polyol having a (meth) acryloyl group as 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.
Further, a (meth) acryloyl group can be introduced into the polyurethane by synthesizing an isocyanate-terminated polyurethane and then end-capping it with a hydroxy functional (meth) acrylate compound. These methods can also be used together.

As the water-dispersed polyurethane (meth) acrylate of the present invention, those described as radiation-curable polyurethane dispersions in [0017] to [0028] of Japanese Patent Laid-Open No. 2014-529639 can be preferably used.

Commercially available water-dispersed polyurethane (meth) acrylates can also be used, for example, UCECOAT® 7674, UCECOAT® 7655, UCECOAT® 769, UCECOAT® 7571, UCECOAT. (Registered Trademark) 7689, UCECOAT (Registered Trademark) 7690, UCECOAT (Registered Trademark) 7890, UCECOAT (Registered Trademark) 7578, UCECOAT (Registered Trademark) 7710, UCECOAT (Registered Trademark) 7730, UCECOAT (Registered Trademark) 7733, All of them have trade names (manufactured by Allnex) and the like, and can be preferably used in the present invention.

Among them, UCECOAT (registered trademark) 7571, UCECOAT (registered trademark) 7655, UCECOAT (registered trademark) 7689, and UCECOAT (registered trademark) 7849, which become tack-free when water is removed, are more preferable, and UCECOAT (registered trademark) 7571 is particularly preferable.
The reason is that by using water-dispersed polyurethane (meth) acrylate, which becomes tack-free when the above water is removed, problems such as soiling the handling roll can be avoided without installing a nitrogen purging facility in the UV irradiation facility. This is because the nitrogen purging equipment can be omitted and the burden of remodeling the polarizing plate manufacturing process is reduced.

(Polyfunctional (meth) acrylate)
The active energy ray-curable polymer composition of the present invention preferably further contains a polyfunctional (meth) acrylate compound in addition to a 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, they can be dispersed in aqueous solutions, further enhancing the effect of improving the moist heat durability of polarizing plates. 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, and among them, the (meth) acrylic equivalent (molecular weight / number of functional groups) 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 a large effect of improving wet and 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 trimethylolpropane. Glycoldi (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, trimethylolethanetri (meth) acrylate, dimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate , Dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate and the like.

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 Propanetri (meth) acrylates, PO-modified trimethylolpropanetri (meth) acrylates, ditrimethylolpropane tetra (meth) acrylates, and tricyclodecanedimethanol di (meth) acrylates are preferred.
These can be contained in combination of two or more. It is also possible to use a commercially available product containing two or more types.

As the polyfunctional (meth) acrylate of the present invention, a commercially available one can be used, and NK ester A-DCP, DCP, A-TMPT, TMPT, ATM-35E, A-TMMT manufactured by Shin Nakamura Chemical Industry Co., Ltd. can be used. , Osaka Organic Chemical Industry Co., Ltd. Viscort (registered trademark) # 195, Viscort (registered trademark) # 300, Viscort (registered trademark) # 360, Daicel Ornex Co., Ltd. Acrylate Monomer IRR 214-K, PETIA, PETRA , TMPTA, TMPEOTA, EBECRYL 135, OTA 480, EBERCRYL 40, BS710, BS730 manufactured by Arakawa Chemical Industry Co., Ltd. and the like.

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

(Polymer 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-A-2014-170130 can be referred to.
Examples of the photopolymerization initiator include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, and disulfide compounds. Examples thereof include fluoroamine compounds, aromatic sulfoniums, lofin dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, coumarins and the like. Specific examples, preferred embodiments, and commercially available products of the photopolymerization initiator are described in paragraphs [0133] to [0151] of JP-A-2009-0986658, and can be preferably used in the present invention as well. can.
In the present invention, a photoinitiator that is liquid at room temperature or a water-soluble photopolymerization initiator is preferable because of its good dispersibility, and a water-soluble photoinitiator is more preferable because it has a greater effect of improving wet and heat durability.

Commercially available photocleavable photoradical polymerization initiators include "Irgacure (registered trademark) 651", "Irgacure (registered trademark) 184", "Irgacure (registered trademark) 819", and "Irgacure (registered trademark)" manufactured by BASF. ) 907 ”,“ Irgacure® 1870 ”(CGI-403 / Irgacure® 184 = 7/3 mixing initiator),“ Irgacure® 500 ”,“ Irgacure® 369 ”, "Irgacure (registered trademark) 1173", "Irgacure (registered trademark) 2959", "Irgacure (registered trademark) 4265", "Irgacure (registered trademark) 4263", "Irgacure (registered trademark) 127", "OXE01", etc.; "Kayacure (registered trademark) DETX-S", "Kayacure (registered trademark) BP-100", "Kayacure (registered trademark) BDMM", "Kayacure (registered trademark) CTX", "Kayacure" manufactured by Nippon Kayaku Co., Ltd. (Registered Trademark) BMS ”,“ KayaCure® 2-EAQ ”,“ KayaCure® ABQ ”,“ KayaCure® CPTX ”,“ KayaCure® EPD ”,“ KayaCure® ) ITX ”,“ KayaCure® QTX ”,“ KayaCure® BTC ”,“ KayaCure® MCA ”, etc .; , X33, KTO46, KT37, KIP150, TZT) ”, and combinations thereof are given as preferable examples.

Among them, "Irgacure (registered trademark) 1173" 2-hydroxy-2-methyl-1-phenyl-propane-1-one or water-soluble "Irgacure (registered trademark) 2959" (1- [ 4- (2-Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one) is more preferred, and the water-soluble "Irgacure® 2959" (1- [4- (4) 2-Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-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 as to polymerize the polymerizable compound contained in the composition and not to increase the starting points too much. For this reason, 0.5 to 8% by mass is preferable, and 1 to 5% by mass is more preferable with respect to the total solid content in the composition.

(Adhesion strengthening agent 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 strengthening agent, 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 a boronic acid compound having an ethylenically unsaturated group is used, the content is preferably 0.01 to 10% by weight based on the solid content of the active energy ray-curable polymer composition (BLC). It is more preferably 05 to 5% by weight, and even more preferably 0.1 to 3% by weight.

Next, as a compound having one or more functional groups and a hydroxyl group selected from the group consisting of an ethylenically unsaturated polymerizable group, an amino group, an amide group, and a carboxy group, the compound of JP2011-221186A. 0031], and such a compound can be preferably used.
When a compound having one or more functional groups and a hydroxyl group selected from the group consisting of an ethylenically unsaturated polymerizable group, an amino group, an amide group, and a carboxy group is used, the content is the above-mentioned active energy ray-curable polymer composition. The solid content of the substance (BLC) is preferably 0.5 to 10% by weight, more preferably 1 to 8% by weight.

A compound having an ethylenically unsaturated group and a blocked isocyanate group will be described. The blocked isocyanate group can suppress the reactivity of the isocyanate group by protecting the isocyanate group with another functional group under normal conditions, while deprotecting the isocyanate group by heating to regenerate the active isocyanate group. Indicates an isocyanate block body.
Examples of commercially available compounds having such an ethylenically unsaturated group and a blocked isocyanate group include 2-[(3,5-dimethylpyrazolyl) carboxyamino] ethyl methacrylate (Carens MOI-BP®, Showa). Denko); 2- (0- [1'methylprovideneamino] carboxyamino) ethyl methacrylate (Carens MOI-BM (registered trademark), Showa Denko) and the like can be mentioned.
When a compound having an ethylenically unsaturated group and a blocked isocyanate group is used, the content is preferably 0.5 to 10% by weight based on the solid content of the active energy ray-curable polymer composition (BLC). It is more preferably 1 to 8% by weight.

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

[Transparent protective film]
The transparent protective film (PF1 and PF2) of the present invention is, for example, a film made of a cellulose-based resin such as triacetyl cellulose or diacetyl cellulose, a film made of a polyester resin such as polyethylene terephthalate, polyethylene naphthalate, or polybutylene terephthalate. , 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 cellulosic resin, particularly a cellulosic 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. As the surface treatment, these two or more treatments may be applied. These surface treatments are generally applied to the surface opposite to the surface to be bonded to the polarizing element. One or both of the transparent protective film and its surface protective layer contains an ultraviolet absorber such as a benzophenone compound or a benzotriazole compound, or a plasticizer such as a phenyl phosphate compound or a phthalate ester compound. May be good.

Transparency as used in the present invention means that the transmittance of visible light 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 characteristics, but if it is too thin, the strength is lowered and the workability is inferior. The appropriate 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 also be used as the transparent protective film (PF2).

[Layer structure of polarizing plate with adhesive layer]
When the polarizing plate with an adhesive layer of the present invention is a single-sided polarizing plate having a transparent protective film (PF1) on only one surface of the polarizing element, the cured layer of the present invention is formed on the surface opposite to the transparent protective film of the polarizing element. Has (BL1). Further, the cured layer (BL2) of the present invention may be provided between the transparent protective film and the polarizing element.
Further, when the polarizing plate with an adhesive layer of the present invention has a transparent protective film (PF1) and a transparent protective film (PL2) on both surfaces of the polarizing element, the surface opposite to the transparent protective film (PF1) of the polarizing element. That is, the cured layer (BL1) of the present invention is provided between the transparent protective film (PF2) and the polarizing element. Further, the cured layer (BL2) of the present invention may be further provided between the transparent protective film (PF1) and the polarizing element.
In the present invention, the layer structure of the polarizing plate with a preferable 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 of manufacturing a polarizing plate with an 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 adhering a transparent protective film and a polarizing element in advance. The polarizing element produced as described above and the transparent protective film (PF1) 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 to form a cured layer (BL2) between the transparent protective film (PF1) and the polarizing element (P). You can also do it.

When adhering the polarizing element and the transparent protective film, one or both of the bonding surfaces of the polarizing element and the transparent protective film are used to improve the adhesiveness between the polarizing element and the adhesive, and the transparent protective film and the adhesive. May be subjected to surface treatment such as corona treatment, plasma treatment, ultraviolet irradiation, and primer coating treatment in advance. Further, the transparent protective film may be saponified.

As described above, a polarizing plate having a transparent protective film (PF1) formed on one side of the polarizing element via an adhesive layer can be obtained.
In the case of a single-sided polarizing plate having a transparent protective film on only one surface of the polarizing element, the polarizing element and the transparent protective film are bonded and laminated using an adhesive as described above, and the transparent protective film is applied to only one side. A single-sided polarizing plate having a single-sided polarizing plate can be produced, and then a cured layer can be laminated on the surface of the single-sided polarizing plate opposite to the transparent protective film of the polarizing element.

(Method of laminating the cured layer)
The cured layer of the present invention may be formed by any method, but the curable composition of the present invention is laminated on a polarizing element while controlling the thickness, and after drying, the cured layer is irradiated with active energy rays to form a cured layer. Is preferable.
In the present invention, preferred methods for laminating the curable composition on the polarizing element while controlling the thickness include a coating method and a method using a pinch roll.

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

Further, in the method using pinch roll, 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 releasable film, and the solution passes through the pinch roll. The pressure can be applied to control the thickness of the cured layer. For this method, for example, the apparatus described in FIG. 2 of JP2012-189966A can be used.

In the method using this pinch roll, a transparent protective film (PF1) is bonded to the polarizing element (P) in advance, and then the active energy ray of the present invention is formed between the polarizing element and the releasable film. A cured layer (BL1) having a controlled thickness can be formed by supplying an aqueous solution of the curable polymer composition (BLC) and passing it through a pinch roll, but when the cured layer (BL1) is laminated, it can be formed. At the same time, it is preferable to simultaneously bond the transparent protective film (PF1) and the polarizing element (P) in terms of productivity.

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

The cured layer is formed by irradiating with active energy rays after drying, and the irradiation with active energy rays can be performed at any stage before or after peeling of the releasable film.
Further, it is also possible to use a transparent protective film (PF2) as a releasable film, and to use a polarizing plate having transparent protective films on both sides of the polarizing element without peeling the film after irradiation with active energy rays. A polarizing plate having transparent protective films on both sides of the polarizing element is also one of the preferred embodiments 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 them, 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, ultraviolet rays emitted from light rays such as ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arcs, xenon arcs, metal halide lamps, and LEDs can be used. Further, in order to promote the curing reaction, the temperature can be raised at the time of curing, preferably 25 to 100 ° C., more preferably 30 to 80 ° C., and most preferably 40 to 70 ° C.

(Adhesive layer)
The present invention has a pressure-sensitive adhesive layer containing an antistatic agent. Examples of the pressure-sensitive adhesive include acrylic-based, vinyl alcohol-based, silicon-based, polyester-based, polyurethane-based, and polyether-based adhesives. Further, it may contain an active energy ray-polymerizable compound.
Examples of the antistatic agent include an ionic conductor composed of an alkali metal salt, an ionic liquid, a surfactant, a conductive polymer, a metal oxide, carbon black, and a carbon nanomaterial. Among them, an ionic conductor and / or an ionic liquid made of an alkali metal is preferably used from the viewpoint of permanent chargeability and non-coloring.

In the present invention, the antistatic agent is preferably an ionic compound containing a fluorine-containing anion. Examples of the ionic compound containing the fluorine-containing anion include an ionic compound composed of an organic cation and a fluorine-containing anion, an ionic compound composed of an alkali metal cation and a fluorine-containing anion, and the like. An ionic compound composed of an organic cation and a fluorine-containing anion is preferable. 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- Etc., especially CF ₃ ^{COO- ,} CF ₃ SO _3- ^, (CF ₃ SO ₂ ) ₂ N- ^, (SO ₂ F) ₂ N- ^, C ₄ F ₉ SO _3- . preferable.

Examples of the organic cation include a pyridinium cation, a piperidium cation, a pyrroline cation, a cation having a pyrroline ring, a cation having a pyrroline ring, an imidazolium cation, a tetraalkylammonium cation and the like. 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 cations, 1-hexyl-4-methylpyridinium cations; 1-propylpiperidinium cations, 1-pentylpiperidinium cations, 1,1-dimethylpiperidinium cations, 1-methyl- 1-Ethylpiperidinium cation, 1-methyl-1-propylpiperidinium cation, 1-methyl-1-butylpiperidinium cation, 1-methyl-1-pentylpiperidinium cation, 1-methyl-1- Piperidinium cations such as hexylpiperidinium cations; 1,1-dimethylpyrridinium cations, 1-ethyl-1-methylpyrrolidinium cations, 1-methyl-1-propylpyrrolidinium cations, 1-methyl- 1-butylpyrrolidinium cation, 1-methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium cation, 1-ethyl-1 -Pyrolidinium cations such as propylpyrridinium cations, 1-ethyl-1-butylpyrrolidinium cations, 1-ethyl-1-pentylpyrrolidinium cations, 1-ethyl-1-hexylpyrrolidinium cations; Cations with a pyrroline ring such as 2-methyl-1-pyrrolin cations; cations with a pyrrol ring such as 1-ethyl-2-phenylindole cations, 1,2-dimethylindole cations, 1-ethylcarbazole cations; 1,3 -Dimethylimidazolium cations, 1,3-diethylimidazolium cations, 1-ethyl-3-methylimidazolium cations, 1-butyl-3-methylimidazolium cations, 1-hexyl-3-methylimidazolium cations, etc. Imidazollium cations; tetraalkylammonium cations such as tetramethylammonium cations, tetraethylammonium cations, tetrabutylammonium cations, tetrahexylammonium cations, triethylmethylammonium cations, tributylethylammonium cations, and trimethyldecylammonium cations can be exemplified.

Specific examples of the ionic compound consisting of 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-methylpyrrolidiumbis (trifluoromethanesulfonyl) imide, 1-butyl-1-methylpyrrolidiumtetrafluoroborate; 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-methyl Imidazolium trifluoromethanesulfonate, 1-methyl-3-octylimidazolium trifluoromethanesulfonate, 1,2,3-trimethylimidazolium trifluoromethanesulfonate, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate; tetraethylammonium tolfluoro Examples thereof include acetate and tetrahexyl ammonium tetrafluoroborate.

On the other hand, examples of the alkali metal cation include K ⁺ , Li ⁺ , and Na ⁺ . Among the ionic compounds composed of alkali metal cations and fluorine-containing anions, LiBF ₄ , LiPF ₆ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) 2N, Li (SO ₂ F) ₂ N, LiC ₄ F ₉ SO ₃ , etc. Lithium salt is preferable because it has 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 mass, based on the total solid content of the pressure-sensitive adhesive composition. be. 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 due to bleeding of the antistatic agent, which is not preferable.

It is preferable to provide a curing step after applying the pressure-sensitive adhesive. This curing step is a step of curing the pressure-sensitive adhesive, but at the same time, the effect of further curing and stabilizing the adhesive layer formed between the above-mentioned polarizing element and the protective film can be obtained. This curing step is performed in 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, but if the curing period is long, the productivity deteriorates, so that it is preferably about 1 to 30 days, more preferably about 1 to 7 days. Further, the polarizing plate with the pressure-sensitive adhesive layer of the present invention may be cut according to the size of the liquid crystal panel used together. This cutting process may be performed after the polarizing plate is attached to the liquid crystal panel.

[Liquid crystal display device]
The liquid crystal display device of the present invention includes a liquid crystal cell and a polarizing plate with a pressure-sensitive adhesive layer of the present invention arranged on 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.

(Configuration of general liquid crystal display device)
The liquid crystal display device includes a liquid crystal cell in which a liquid crystal is supported between two electrode substrates, two polarizing plates arranged on both sides thereof, and, if necessary, between the liquid crystal cell and the polarizing plate. It has a configuration in which at least one optical compensation film is arranged.
The liquid crystal layer of a liquid crystal cell is usually formed by enclosing a 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 be further provided with a gas barrier layer, a hard coat layer, or an undercoat layer (undercoat layer) (used for adhering 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.

(Type of liquid crystal display device)
The film of the present invention can be used for liquid crystal cells in various display modes. TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), AFLC (Anti-ferroelectric Liquid Crystal), OCB (Optical Type Various display modes such as (Electricularly Controlled Birefringence) and HAN (Hybrid Aligned Nematic) have been proposed. In addition, a display mode in which the above display mode is oriented and divided is also proposed. The polarizing plate of the present invention is effective in a liquid crystal display device in any display mode. Further, any of a transmissive type, a reflective type, and a semi-transmissive type liquid crystal display device can be used.

When the polarizing plate of the present invention is attached to both sides of the liquid crystal cell in the IPS mode, light leakage when viewed from an oblique direction at the time of black display is suppressed, which is particularly preferable.

Hereinafter, the present invention will be specifically described based on Examples. The materials, reagents, amounts of substances and their ratios, operations, etc. shown in the following examples can be appropriately changed as long as they do not deviate 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 the following layer structure having a transparent protective film on only one side of the polarizing element as an example.
Transparent protective film (PF1) / polarizing element (P) / cured layer (BL1) / adhesive layer

(Manufacturing of polarizing element)
A PVA film having an average degree of polymerization 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. Then, the PVA film was dyed while being immersed in an aqueous solution having a concentration of iodine / potassium iodide (weight ratio = 2/3) of 0.6% by weight and stretched 2.1 times. Then, it 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 adhesive for polarizing plate)
A modified PVA-based resin containing an acetoacetyl group (manufactured by Nippon Synthetic Chemistry Co., Ltd .: Gosenex Z-410) was dissolved in water to prepare an aqueous solution A adjusted to a solid content concentration of 3%. Then, maleic acid was added so as to be 0.5% by weight with respect to the aqueous solution A, and then glyoxal was added as a cross-linking agent. The amount of glyoxal added 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 an adhesive for a polarizing plate.

(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. Then, after immersing the film in a 0.05 mol / L sulfuric acid aqueous solution at 25 ° C. for 30 seconds, the film was further passed through a water washing bath for 30 seconds under running water to neutralize the film. Then, draining with an air knife was repeated three times, and after the water was dropped, the film was allowed to stay in a drying zone at 70 ° C. for 15 seconds to be dried to prepare a saponified film.

(Manufacturing 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 is rolled onto the polarizing element 1 via the adhesive layer. After bonding using a combination machine, the mixture was dried at 60 ° C. for 10 minutes to obtain a single-sided polarizing plate.

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

(Composition of composition BLC-1 for forming a hardened layer)
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

Pure water was added to the above formulation so that the solid content concentration was 35% by weight, and after mixing, ultrasonic waves were applied, and then a cured layer forming composition (BLC-1) was prepared through a filter having a pore size of 5 μm. ..
Similar to the cured layer forming composition BLC-1, the cured layer forming compositions BLC-2 to BLC-8 were prepared. The ratio of each composition is shown in Table 1. Table 1 shows the content mass ratio of the solid content of each component. Here, the solid content is a composition excluding a solvent (in BLC-1, water: including those contained in UCECOAT 7571).

The materials used in Table 1 are shown below.
-UCECOAT 7571: Water-dispersible polyurethane (meth) acrylate (UV Cureble Waterborne Resin) [manufactured by Allnex] 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 Waterborne Resin) [manufactured by Allnex] 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 Industry Co., Ltd.] Viscosity: 110 (mPa · s / 25 ° C.), Acrylic equivalent: 98.7
Viscosity # 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: Tricyclodecanedimethanol diacrylate [manufactured by Shin Nakamura Chemical Industry Co., Ltd.] Viscosity: 120 (mPa · s / 25 ° C.), Acrylic equivalent: 152.0
BS-710: Pentaerythritol polyacrylate (main component is pentaerythritol tetraacrylate) [manufactured by Arakawa Chemical Industry Co., Ltd.] Viscosity: 500 (mPa · s / 25 ° C.), Acrylic equivalent: 88.0

BS-730: Ditrimethylolpropane tetraacrylate [manufactured by Arakawa Chemical Industry Co., 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)

(Manufacturing of single-sided polarizing plate with hardened layer)
Using a bar coater, the cured layer forming composition (BLC-1) was applied onto the polarizing element of the single-sided polarizing plate prepared above so that the film thickness after drying was 2.5 μm, and then at 60 ° C. It was dried for 10 minutes. Then, using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) with an output of 160 W / cm at atmospheric pressure, the coating layer is cured by irradiating it 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. (Polarizer 1)

(Preparation of polarizing plates 2 to 14)
Single-sided polarizing plates 2 to 14 were produced in the same manner as the polarizing plate 1 except that the type of the cured layer forming composition and the film thickness of the cured layer were changed as shown in Table 1. Further, the single-sided polarizing plates 13 and 14 did not have a cured layer laminated on the polarizing element.

Next, a polarizing plate with an adhesive layer will be described.
(Preparation of adhesive composition)
Ion consisting of 1-butyl-3-methylpyridinium cation, which is an ionic compound consisting of an organic cation and a fluorine-containing anion, and (CF ₃ SO ₂ ) ₂ N anion as an antistatic agent according to Example 12 of the International Publication No. 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)
An adhesive layer was applied onto the peeled PET peeling film using a doctor blade, and dried at 90 ° C. for 3 minutes. After drying, it was attached to the cured layer side (the side on which the protective film was not laminated) of the above-mentioned polarizing plate 1 and left to stand for 7 days under the conditions of 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 adhesive layer)
Polarizer 1 with adhesive layer, except that the type of the composition for forming the cured layer, the film thickness of the cured layer, and the type of the adhesive composition are changed to those shown in Table 2 with respect to the polarizing plate 1 with the adhesive layer. In the same manner as above, polarizing plates 2 to 14 with an adhesive layer were obtained.
The polarizing plates 13 and 14 with the pressure-sensitive adhesive layer do not have a cured layer, and the pressure-sensitive adhesive layer is directly laminated on the polarizing element.

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

Amount of change in degree of polarization ΔPE = (degree of polarization before charging)-(degree of polarization after charging)
The degree of polarization was calculated according to the following method.
The transmittance (Tp) when the two prepared polarizing plates are overlapped in parallel with the absorption axes and the transmittance (Tc') when the absorption axes are orthogonally overlapped are measured, and the degree of polarization is measured from the following formula. (PE) was calculated.
Degree of polarization PE = ((Tp-Tc') / (Tp + Tc')) ^0.5 x 100 [%]
In the present invention, ΔPE after the wet heat durability test needs to be 1.0% or less, preferably 0.50% or less, more preferably 0.10% or less, and particularly preferably 0.02% or less.

(Measurement of surface resistance value)
After peeling off the PET release film of the adhesive polarizing plate, the surface resistance value on the surface of the adhesive layer is measured using a super-insulation resistance / micro ammeter TR8601 (manufactured by Advantest Co., Ltd.), and the surface resistance value (Ω / □). ) Is shown by the common logarithm (logSR). The lower the log SR, the better the antistatic property, and in the present invention, it is necessary to be 14.0 or less, and more preferably 13.0 or less.

From the results shown in Table 1, the following is clear.
1. 1. Adhesion containing an antioxidant on the cured layer of a single-sided polarizing plate having a cured layer formed from an aqueous solution of an active energy ray-curable composition containing a polymer compound having an ethylenically unsaturated group as a main component of the present invention. The polarizing plate with an adhesive on which the agent layer is laminated does not have a decrease in the degree of polarization after the moist heat durability test and has good moist heat resistance.
2. 2. When the active energy ray-curable composition contains a polymer compound having an ethylenically unsaturated group as a main component and further contains a polyfunctional (meth) acrylate compound, the degree of polarization after the moist heat endurance test is less lowered and the moist heat endurance is further increased. The sex is also good.

Next, an example in which an adhesion strengthening agent is used in the composition for forming a hardened layer will be shown.
(Preparation of composition BLC-9 for forming a hardened layer)
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 hardened layer)
UCECOAT 7571 84.0 parts by mass A-TMP 12.0 parts by mass 4-vinylphenylboronic acid 1.0 parts by mass Irgacure 2959 3.0 parts by mass

(Preparation of composition BLC-9 for forming a hardened layer)
A cured layer forming composition (BLC-10) was prepared in the same manner as in the same manner as for 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)
Plates 15 and 16 with a pressure-sensitive adhesive were prepared in the same manner except that the compositions for forming a cured layer were replaced with (BLC-9) and (BLC-10) for the polarizing plate 1 with a pressure-sensitive adhesive layer.
Further, the polarizing plates with adhesive 15 and 16 were evaluated in the same manner as the polarizing plate with adhesive 1 except that the polarizing plate 22 with adhesive or the polarizing plate 23 was replaced with the polarizing plate 23. The results are shown in Table 2.

From the results shown in Table 2, it is clear that even if a boronic acid compound is used as an adhesion strengthening agent in the cured layer forming composition, the degree of polarization does not decrease after the moist heat durability test and the moist heat resistance is also good.

Next, the present invention will be described by taking the following two layer configurations having transparent protective films on both sides of the polarizing element as an example.
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)
Cellulose auspicus containing no ultraviolet absorber having a film thickness of 20 μm in the same manner except that the flow rate is adjusted so that the mainstream thickness is 14 μm with reference to paragraphs [0160] to [0163] of JP2012-177894. 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 in the saponification of the cellulose acylate film TD60 described above.
(Manufacturing 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 the sacrifice-treated cellulose acylate film TD60 so that the thickness after drying is 80 nm, and at the same time, a curable composition (CA-1) is also applied to the sacrifice-treated cellulose acylate film (CA-1). While applying BLC-6) so that the thickness after drying is 2.5 μm, the polarizing element is subjected to a polarizing plate adhesive and a curable composition (BLC-6) using a roll bonding machine. A saponified cellulose acylate film TD60 and a sacrifice-treated cellulose acylate film (CA-1) were laminated on both sides.

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

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

(Preparation of polarizing plate 23)
Instead of the curable composition (BLC-6), a polarizing plate adhesive was applied to the polarizing plate 21 on one side of the saponified cellulose acylate film (CA-1) so that the thickness after drying would be 80 nm. The polarizing plate 23 was manufactured in the same manner as the polarizing plate 21 except for the above.

(Preparation of polarizing plate 21 with adhesive layer)
An adhesive layer was applied onto the peeled PET peeling film using a doctor blade, and dried at 90 ° C. for 3 minutes. After drying, it was attached to the cellulose acylate film (CA-1) side of the above polarizing plate 21 and left 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)
The polarizing plate 22 with the pressure-sensitive adhesive and the polarizing plate 23 with the pressure-sensitive adhesive were produced in the same manner except that the polarizing plate 21 with the pressure-sensitive adhesive layer was replaced with the polarizing plate 22 or the polarizing plate 23, respectively.

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

The following is clear from the results shown in Table 3.
1. 1. Even in a polarizing plate with an adhesive having a transparent protective film on both sides and laminated with an adhesive layer containing an antioxidant, the cured layer of the present invention is laminated between the transparent protective film and the polarizing element on the adhesive layer side. By doing so, the degree of polarization does not decrease after the moist heat durability test, and the moist heat durability is also 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-based resin layer, and a cured layer (BL1) and an antistatic agent-containing 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 , contains a polymer compound having an ethylenically unsaturated group as a main component, and 1- [4- (2-hydroxyethoxy) -phenyl]. It was formed from an aqueous solution of an active energy ray-curable polymer composition containing -2-hydroxy-2-methyl-1-propane-1-one .
The polymer compound having an ethylenically unsaturated group is a polarizing plate with a pressure-sensitive adhesive layer, which is at least a part of a self-emulsifying emulsion . 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-based resin layer, and a cured layer (BL1) and an antistatic agent-containing 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, contains a polymer compound having an ethylenically unsaturated group as a main component, and 1- [4- (2-hydroxyethoxy) -phenyl]-. It was formed from an aqueous solution of an active energy ray-curable polymer composition containing 2-hydroxy-2-methyl-1-propane-1-one.
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). , Polarizing plate with adhesive layer. The polarizing plate with an adhesive layer according to claim 1 or 2, wherein the polymer compound having an ethylenically unsaturated group is a self-emulsifying emulsion in which at least a part thereof is a water-dispersible polyurethane (meth) acrylate. The active energy ray-curable polymer composition further contains a polyfunctional (meth) acrylate compound, and the content of the polyfunctional (meth) acrylate compound is a solid in an aqueous solution of the active energy ray-curable polymer composition. The polarizing plate with an adhesive layer according to any one of claims 1 to 3, which is 1 to 40% by weight in a minute. Claims 1 to 4 are characterized in that the content of the polymer compound having an ethylenically unsaturated group in the solid content is 50 to 99% by weight in the aqueous solution of the active energy ray-curable polymer composition. The polarizing plate with an adhesive layer according to any one of. The polarizing plate with an adhesive layer according to any one of claims 1 to 5, wherein the polymer compound having an ethylenically unsaturated group has a number average molecular weight of 5000 to 100,000. The polarized light with a pressure-sensitive adhesive layer according to any one of claims 1 to 6, wherein the aqueous solution of the active energy ray-curable polymer composition further contains a boronic acid compound having an ethylenically unsaturated group. Board. The polarizing plate with a pressure-sensitive adhesive layer according to claim 7 , wherein the boronic acid compound is 4-vinylphenylboronic acid or a boronic acid compound represented by the following formula.

Claim 1 is characterized in that the pressure-sensitive adhesive layer is provided directly or via a transparent protective film (PF2) on the surface of the cured layer (BL1) of the polarizing plate opposite to the polarizing element (P). The polarizing plate with an adhesive layer according to any one of 8 to 8. The polarizing plate with an adhesive layer according to claim 9, wherein the transparent protective film (PF2) is a cellulose acylate-based film having a thickness of 10 to 50 μm. The polarizing plate with a pressure-sensitive adhesive layer according to any one of claims 1 to 10, wherein the pressure-sensitive adhesive layer contains an ionic antistatic agent. A liquid crystal display device in which the polarizing plate according to any one of claims 1 to 11 is attached 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 any one of claims 1 to 11 , wherein a polymer compound having an ethylenically unsaturated group is used as an aqueous solution in an aqueous solution. An active energy ray-curable polymer composition comprising 50 to 99% by weight of a polyfunctional (meth) acrylate compound 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-based resin layer to form a single-sided polarizing plate.
A step of applying an aqueous solution of an active energy ray-curable polymer composition in which the main solvent is water onto the polarizing element of the single-sided polarizing plate.
After drying the applied aqueous solution of the active energy ray-curable polymer composition, the step of irradiating the applied active energy ray under atmospheric pressure and normal atmosphere to form a cured layer, and the antistatic agent-containing pressure-sensitive adhesive layer are performed. The method for manufacturing a polarizing plate with an adhesive layer according to any one of claims 1 to 11 , further comprising a step of providing.