JP7329644B2 - POLARIZING PLATE WITH ADHESIVE LAYER, MANUFACTURING METHOD THEREOF, ACTIVE ENERGY-RADIATION-CURED POLYMER COMPOSITION USED FOR MANUFACTURING THE SAME, AND LIQUID CRYSTAL DISPLAY DEVICE - Google Patents

Description

The present invention provides a polarizing plate with a pressure-sensitive adhesive layer having a polarizing element formed by adsorbing and aligning iodine on a polyvinyl alcohol-based resin layer, and a curable layer formed of a specific ionizing radiation-curable composition in a water solvent, and a polarizing plate thereof. It relates to a method for manufacturing a board. 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 applications such as liquid crystal televisions, liquid crystal panels for personal computers, mobile phones, digital cameras, and the like. Generally, a liquid crystal display device has a liquid crystal panel member in which polarizing plates are adhered to both sides of a liquid crystal cell with an adhesive, and display is performed by controlling light from a backlight member with the liquid crystal panel member. Here, the polarizing plate is composed of a polarizing element and protective films laminated on both sides thereof. A cellulose acylate film or the like is used as a protective film.

In recent years, in order to make the liquid crystal panel thinner, the polarizing plate protective film on the liquid crystal cell side has been removed from the two protective films laminated on 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 in order 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 only on one side of the polarizer, the pressure-sensitive adhesive layer is laminated on the polarizing element without the protective film interposed therebetween, as described in Patent Document 2. If a pressure-sensitive adhesive layer containing an ionic liquid or an ionic solid is laminated on a polarizing element without a protective film interposed therebetween, the polarizing element is deteriorated and the wet heat durability performance is lowered, resulting in a large deterioration in optical properties.

International publication 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 to have a polarizing plate protective film only on one side of the polarizing element and to A thin polarizing plate with an adhesive layer, which has an adhesive layer containing an antistatic agent such as a liquid, and yet has excellent optical properties even after the endurance test. It is to provide a board.

As a result of intensive studies by the present inventors, it is presumed that the decrease in optical properties after the wet heat durability test is due to the migration of the antistatic agent in the adhesive and the iodine complex in the polarizing element using moisture as a medium. ) An ultraviolet curable composition obtained by dissolving an acrylate monomer and a photopolymerization initiator in an organic solvent is applied on the polarizing element of a single-sided polarizing plate, dried, and then irradiated with UV under a nitrogen purge to form a cured layer. movement can be suppressed, and the wet heat durability of the polarizing plate is improved.

However, in the process of manufacturing a polarizing plate using a polarizing element produced by adsorbing and orienting iodine on a polyvinyl alcohol-based resin layer, almost no organic solvent is usually used. Not designed for organic solvents. Therefore, in order to introduce the above method into the manufacturing process of the polarizing plate, the manufacturing equipment must be modified to the specifications of the organic solvent, which imposes a considerable burden on the polarizing plate manufacturer. In addition, a new problem that the use of organic solvents (VOC) increases the load on the environment has also emerged.
In addition, when using a polyfunctional (meth)acrylate monomer, if UV irradiation is performed in the atmosphere without using nitrogen purge equipment, the cured layer surface becomes unreacted due to the inhibition of curing by oxygen. problems such as adhesion of As a result, a new problem arises that requires the introduction of nitrogen purge equipment.

In view of the above circumstances, 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 only on one surface of a polarizing element and an ionic liquid or the like on the other surface. A thin polarizing plate with an adhesive layer that has an adhesive layer containing an antistatic agent, yet has good optical properties even after a wet heat durability test. , to provide a polarizing plate by a method that requires less modification of the polarizing plate manufacturing process and less burden on the environment, and 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 a further object of the present invention is to provide a liquid crystal having durability against humidity and heat, which exhibits improved display characteristics after a durability test on humidity and heat. It is to provide a display device.

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

In addition, even in a polarizing plate having transparent protective films 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 wet heat durability of the polarizing plate. I found that it can be done, and came to the completion of the second invention. In particular, as described above, it is presumed that the decrease in optical properties after the wet heat durability test, which is a problem in the present invention, occurs with moisture as a medium. The effect is observed when the cellulose acylate film has a relatively high moisture permeability and a thickness of 10 to 50 μm.
The problems to be solved by the present invention can be solved by the following means.

(1) A transparent protective film (PF1) is provided on one side of a polarizing element (P) formed by adsorbing and aligning iodine on a polyvinyl alcohol-based resin layer, and a cured layer (BL1) and an antistatic agent are provided on the other side. A polarizing plate with an adhesive layer provided with an adhesive layer containing
The cured layer (BL1) has an average 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 a pressure-sensitive adhesive layer, characterized in that it is a polarizer.
(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 ) with a pressure-sensitive adhesive layer.

(3) The above (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 ethylenically unsaturated groups 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 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 or via a transparent protective film (PF2) on the opposite side of the polarizing element (P) of the cured layer (BL1) of the polarizing plate ( The polarizing plate with an adhesive layer according to any one of 1) to (7).
(9) The polarizing plate with an adhesive layer as described in (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 an adhesive layer as described in any one of (1) to (9), wherein the adhesive layer contains an ionic antistatic agent.

(11) A cured layer (BL2) having a 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), characterized in that
(12) A liquid crystal display device in which the polarizing plate according to any one of (1) to (11) is adhered to at least one side of a liquid crystal cell.
(13) An active energy ray-curable polymer composition used for the production of a polarizing plate according to any one of (1) to (11), which, when made into an aqueous solution, contains a high An active energy ray-curable polymer composition characterized by containing 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 aligning iodine on a polyvinyl alcohol-based resin layer to form a single-sided polarizing plate;
applying an aqueous solution of an active energy ray-curable polymer composition containing water as a main solvent onto the polarizing element of the single-sided polarizing plate;
After drying the applied aqueous solution of the active energy ray-curable polymer composition, a step of irradiating an active energy ray under normal atmosphere under atmospheric pressure to form a cured layer, and an antistatic agent-containing pressure-sensitive adhesive layer. The method for producing a polarizing plate with an adhesive layer according to any one of (1) to (11), comprising the step of providing.

According to the present invention, it is possible to provide a pressure-sensitive adhesive layer-attached polarizing plate that is thin, has excellent antistatic properties, and has durability against humidity and heat with little change in optical properties (decrease in degree of polarization, etc.) after a durability test under humidity and heat. By using the pressure-sensitive adhesive layer-attached polarizing plate of the present invention, it is possible to provide a display device in which light leakage is suppressed after the passage 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 in 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-based resin film, dyeing the PVA-based resin film with iodine, and uniaxially stretching the film.

As the PVA-based resin, generally used is one obtained by saponifying a polyvinyl acetate-based resin, as described above. The degree of saponification is about 85 mol % or more, preferably about 90 mol % or more, more preferably about 99 mol % to 100 mol %. Examples of polyvinyl acetate-based resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate with other monomers copolymerizable therewith, such as ethylene-vinyl acetate copolymers. Amalgamation etc. are mentioned. Other copolymerizable monomers include, for example, unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids and the like. The degree of polymerization of the PVA-based resin is 1,000 to 10,000, preferably 1,500 to 5,000. This PVA-based resin may be modified, for example, aldehyde-modified polyvinyl formal, polyvinyl acetal, polyvinyl butyral, or the like.

The manufacturing method of the polarizing element is not particularly limited, but there is a method in which a polyvinyl alcohol-based resin film wound in advance in a roll is sent out and stretched, dyed, cross-linked, etc., or a method in which a polyvinyl alcohol-based resin and a resin base material for stretching are used. A typical method includes a step of producing a laminate of the above and stretching the laminate. Any of these methods can be used in the present invention. 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. Moreover, the thickness of the polarizing element of the present invention is preferably 3 to 35 μm, more preferably 4 to 30 μm, even more preferably 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 water as a main solvent. In the present invention, the content of a polymer compound having an ethylenically unsaturated group as a main component means that the content of the polymer compound having an ethylenically unsaturated group is the highest in the aqueous solution solid content of the curable polymer composition. means that One type or two or more types of polymer compounds having an ethylenically unsaturated group may be used. When there are two or more types of polymer compounds having ethylenically unsaturated groups, the "content of polymer compounds having ethylenically unsaturated groups" means the content of all polymer compounds having ethylenically unsaturated groups (compounds means 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. More preferred. By suppressing the content within this range, it is possible to suppress the change in optical properties of the polarizing plate laminated with the cured layer after the moisture resistance test.
In the structure of the polarizing plate having two layers of 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 from the viewpoint of productivity, it may be formed from different active energy ray-curable polymer compositions.

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, which is effective in improving wet heat durability. point is preferable. The present inventors presume that a hydrophobic structure is preferable for improving wet heat durability, but an emulsion-type polymer compound has a hydrophobic structure and is preferable from the viewpoint of improving wet heat durability.
There are two types of emulsion-type polymer compounds: the forced emulsification type, which uses a surfactant as an emulsifier, and the self-emulsification type, which introduces a hydrophilic group into the compound. There is no bleed out, which is more preferable in the present invention.

Next, a water-dispersible polyurethane (meth)acrylate, which is a self-emulsifying emulsion having a polyurethane structure and (meth)acrylate groups, 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)
In general, polyurethane is a reaction product of polyol and polyisocyanate. By using polyol having functional groups (hydrophilic groups) with ionic or non-ionic hydrophilicity in at least a part of polyol, it is possible to make polyurethane hydrophilic. groups can be introduced. Preferred examples of such polyols have one or more anionic salt groups, such as carboxylate and sulfonate groups, or acidic groups that can be converted into anionic bases, such as carboxylic acid groups or sulfonic acid groups. polyols. Specifically, α,α-dimethylolalkanoic acid, such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, etc. can be mentioned as examples of preferred polyols.

Similarly, a (meth)acryloyl group can be introduced into the polyurethane by using a polyol having (meth)acryloyl groups in at least a portion of the polyol. Preferred such compounds are (meth)acryloyldihydroxy compounds and poly(meth)acryloyldihydroxy compounds.
Alternatively, (meth)acryloyl groups 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 also 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-T-2014-529639 can be preferably used.

Commercially available water-dispersed polyurethane (meth)acrylates can also be used. (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, (above All of them are 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 are more preferable, and UCECOAT (registered trademark) 7571 is particularly preferable.
The reason for this is that using the water-dispersed polyurethane (meth)acrylate that becomes tack-free when the water is removed makes it possible to avoid problems such as contamination of the handling rolls without installing nitrogen purge equipment in the UV irradiation equipment. This is because the nitrogen purge equipment can be omitted, and the burden of modification of the polarizing plate manufacturing process can be 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 the self-emulsifying emulsion comprising a polymer compound having an ethylenically unsaturated group. Hydrophobic polyfunctional (meth)acrylate compounds alone are difficult to disperse in water, but when used in combination with a self-emulsifying emulsion, they can be dispersed in an aqueous solution, increasing the effect of improving the wet heat durability of polarizing plates. be able to.
Polyfunctional (meth)acrylate compounds that can be preferably used in the present invention are esters of polyhydric alcohol and (meth)acrylic acid, among which 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 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, 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 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 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 Propane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and tricyclodecanedimethanol di(meth)acrylate are preferred.
These can be contained in combination of two or more. Moreover, the commercial item containing two or more types can also be used.

Commercially available polyfunctional (meth)acrylates of the present invention can be used. , Osaka Organic Chemical Industry Co., Ltd. Viscoat (registered trademark) # 195, Viscoat (registered trademark) # 300, Viscoat (registered trademark) # 360, Daicel Allnex Co., Ltd. Acrylate monomer IRR 214-K, PETIA, PETRA , 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, preferably 5 to 25% by weight, based on the solid content of the active energy ray-curable polymer composition (BLC). is more preferred, and 8 to 20% by weight is even more preferred. Within this range, the polarizing plate provided with the cured layer has good wet heat durability, 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. For these polymerization initiators, the description in paragraphs [0064] to [0067] of JP-A-2014-170130 can be referred to.
Photopolymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, fluoroamine compounds, aromatic sulfoniums, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, coumarins and the like. Specific examples of the photopolymerization initiator, preferred embodiments, commercial products, etc. are described in paragraphs [0133] to [0151] of JP-A-2009-098658, and can be suitably used in the present invention as well. can.
In the present invention, a photoinitiator that is liquid at room temperature or a water-soluble photoinitiator is preferable because of its good dispersibility, and a water-soluble photoinitiator is more preferable because it has a large effect of improving wet 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 (registered trademark) 1870" (CGI-403/Irgacure (registered trademark) 184 = 7/3 mixed initiator), "Irgacure (registered trademark) 500", "Irgacure (registered trademark) 369", "Irgacure (registered trademark) 1173", "Irgacure (registered trademark) 2959", "Irgacure (registered trademark) 4265", "Irgacure (registered trademark) 4263", "Irgacure (registered trademark) 127", "OXE01" and the like; 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) QTX", "Kayacure (registered trademark) BTC", "Kayacure (registered trademark) MCA", etc.; , X33, KTO46, KT37, KIP150, TZT)", and combinations thereof.

Among them, as a liquid initiator 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 preferred, and the 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 initiation points are not excessively increased. 0.5 to 8% by mass, more preferably 1 to 5% by mass, based on the total solid content in the composition.

(Adhesion enhancer for polarizing element)
At least one 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 carboxyl group, in order to strengthen the adhesion between the polarizing element and the cured layer. and a hydroxyl group, or a compound having an ethylenically unsaturated group and a blocked isocyanate group can also be used.

Regarding adhesion enhancers, boronic acid derivatives are described in paragraph [0166] of JP-A-2012-150428, and among these, boronic acid compounds 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). 05 to 5% by weight is more preferable, and 0.1 to 3% by weight is even more preferable.

Next, an ethylenically unsaturated polymerizable group and an amino group, an amide group, and a compound having one or more functional groups and a hydroxyl group selected from the group consisting of a carboxy group, JP 2011-221186 paragraph [ 0031], and such compounds can be preferably used.
When using a compound having an ethylenically unsaturated polymerizable group, 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, the content is the active energy ray-curable polymer composition It is preferably 0.5 to 10% by weight, more preferably 1 to 8% by weight, based on the solid content of the product (BLC).

A compound having an ethylenically unsaturated group and a blocked isocyanate group will be described. A blocked isocyanate group means that under normal conditions, the isocyanate group is protected with another functional group to suppress the reactivity of the isocyanate group, while the isocyanate group can be deprotected by heating to regenerate the active isocyanate group. Indicates an isocyanate-blocked product.
Commercially available compounds having such an ethylenically unsaturated group and a blocked isocyanate group include, for example, 2-[(3,5-dimethylpyrazolyl)carboxyamino]ethyl methacrylate (Karenz MOI-BP (registered trademark), Showa Denko); 2-(0-[1'methylpropylideneamino]carboxyamino)ethyl methacrylate (Karenzu MOI-BM (registered trademark), Showa Denko), and the like.
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 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 largest among all the solvents contained in the curable composition. The water content in the total solvent is preferably 70 to 100% by weight, more preferably 80 to 100% by weight, even more preferably 90 to 100% by weight, even more preferably 95 to 100% by weight. It is particularly preferred to have

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

The surface of the transparent protective film may be subjected to surface treatment such as antiglare treatment, antireflection treatment, hard coat treatment, antistatic treatment, antifouling treatment, and the like to form a surface treatment layer. Two or more of these treatments may be applied to the surface treatment. These surface treatments are generally applied to the surface opposite to the bonding surface with the polarizing element. Either or both of the transparent protective film and its surface protective layer contain ultraviolet absorbers such as benzophenone compounds and benzotriazole compounds, and plasticizers such as phenylphosphate compounds and phthalate compounds. good too.

The term “transparent” 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 properties, but if it is too thin, the strength will be reduced and the workability will be poor. A suitable film thickness is 5 to 100 μm, preferably 10 to 80 μm, more preferably 15 to 70 μm.
An optical compensation film having an optically anisotropic layer can also be used as the transparent protective film (PF2) depending on the application of the polarizing plate.

[Layer structure of polarizing plate with adhesive layer]
When the pressure-sensitive adhesive layer-attached polarizing plate of the present invention is a single-sided polarizing plate having a transparent protective film (PF1) only on one side of the polarizing element, the cured layer of the present invention is applied to the opposite side of the polarizing element to the transparent protective film. (BL1). Furthermore, the cured layer (BL2) of the present invention may be provided between the transparent protective film and the polarizing element.
Further, when the pressure-sensitive adhesive layer-attached polarizing plate 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, it has the cured layer (BL1) of the present invention between the transparent protective film (PF2) and the polarizing element. Further, the cured layer (BL2) of the present invention may be provided between the transparent protective film (PF1) and the polarizing element.
In the present invention, the preferred layer structure of the pressure-sensitive adhesive layer-attached polarizing plate is shown below.

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

[Method for producing a polarizing plate with an adhesive layer]
Next, the method for producing the pressure-sensitive adhesive layer-attached polarizing plate 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 and the transparent protective film (PF1) produced as described above can be adhered and laminated using a known adhesive. Further, as described below, the active energy ray-curable polymer composition (BLC) of the present invention is allowed to function as an adhesive to form a cured layer (BL2) 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. Moreover, you may saponify to a transparent protective film.

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

(Lamination method of hardened layer)
Although the cured layer of the present invention may be formed by any method, the curable composition of the present invention is laminated on a polarizing element while controlling the thickness, and after drying, an active energy ray is irradiated to form a cured layer. is preferred.
Preferable methods 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 the cured layer 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 the polarizing element (P) and the transparent protective film (PF1) in advance, as described above.

Further, 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 passed through the pinch rolls. The thickness of the cured layer can be controlled by applying pressure. For this method, for example, the apparatus described in FIG. 2 of JP-A-2012-189968 can be used.

In the method using this pinch roll, a transparent protective film (PF1) is laminated to the polarizing element (P) in advance, and then the active energy ray of the present invention is applied between the polarizing element and the releasing 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. From the viewpoint of productivity, it is preferable to bond the transparent protective film (PF1) and the polarizing element (P) at the same time.

In this case, a transparent protective film (PF1) is supplied to one surface of the polarizing element (P), a releasing 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 ( The bonding of PF1) and the polarizer (P) and the formation of the cured layer (BL1) of the present invention can be performed simultaneously. After that, by peeling off the release film, a single-sided polarizing plate having a transparent protective film (PF1) only on one side of the polarizing element and the cured layer (BL1) of the present invention on the other side of the polarizing element is obtained. can be made.

The cured layer is formed by irradiating the layer with an active energy ray after drying, and the irradiation with the active energy ray can be performed at any stage before or after the release film is peeled off.
Alternatively, a transparent protective film (PF2) may be used as the releasing film, and the polarizing plate may have transparent protective films on both sides of the polarizing element without peeling off the film after irradiation with active energy rays. A polarizing plate having transparent protective films on both sides of this polarizing element is also one of the preferred embodiments of the present invention.

In the present invention, active energy rays such as radiation, gamma rays, alpha rays, electron beams and ultraviolet rays are used 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, ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arcs, xenon arcs, metal halide lamps, and ultraviolet rays emitted from light sources such as LEDs can be used. Also, in order to accelerate the curing reaction, the temperature can be raised during 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 an adhesive layer containing an antistatic agent. Examples of adhesives include acrylic, vinyl alcohol, silicone, polyester, polyurethane, and polyether. Moreover, the active energy ray polymerizable compound may be included.
Examples of antistatic agents include ion conductors made of alkali metal salts, ionic liquids, surfactants, conductive polymers, metal oxides, carbon black, and carbon nanomaterials. Among them, ion conductors and/or ionic liquids made of alkali metals are preferably used from the viewpoint of permanent chargeability and no coloration.

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 consisting of an organic cation and a fluorine-containing anion is preferred. 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 ⁻ as fluorine-containing anions and the like, and it is particularly preferred that it is any one of 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 organic cations include pyridinium cations, piperidinium cations, pyrrolidium cations, pyrroline ring-containing cations, pyrrole ring-containing cations, imidazolium cations, tetraalkylammonium cations, 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 cation, 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- piperidinium cations such as hexylpiperidinium 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 -pyrrolidinium cations such as propylpyrrolidinium cations, 1-ethyl-1-butylpyrrolidinium cations, 1-ethyl-1-pentylpyrrolidinium cations, 1-ethyl-1-hexylpyrrolidinium cations; cations having a pyrroline ring such as 2-methyl-1-pyrroline cation; cations having a pyrrole ring such as 1-ethyl-2-phenylindole cation, 1,2-dimethylindole cation, 1-ethylcarbazole cation; 1,3 -dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, etc. imidazolium cation; tetraalkylammonium cations such as tetramethylammonium cation, tetraethylammonium cation, tetrabutylammonium cation, tetrahexylammonium cation, triethylmethylammonium cation, tributylethylammonium cation, and trimethyldecylammonium cation.

Specific examples of ionic compounds composed of organic cations and fluorine-containing anions include 1-butyl-4-methylpyridinium tetrafluoroborate, 1-butyl-4-methylpyridinium hexafluorophosphate, 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl)imide, 1-butyl-1-methylpyrrolidium bis(trifluoromethanesulfonyl)imide, 1-butyl-1-methylpyrrolidium 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-methyl imidazolium trifluoromethanesulfonate, 1-methyl-3-octylimidazolium trifluoromethanesulfonate, 1,2,3-trimethylimidazolium trifluoromethanesulfonate, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate; tetraethylammonium trifluoromethanesulfonate Acetate, tetrahexylammonium tetrafluoroborate and the like.

On the other hand, examples of alkali metal cations include K ⁺ , Li ⁺ , Na ⁺ and the like. 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. among ionic compounds consisting of alkali metal cations and fluorine-containing anions is preferable because of its good antistatic performance.

The amount of the antistatic agent in the 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 adhesive composition. be. If the amount is less than 0.01% by weight, sufficient antistatic performance cannot be obtained, and if the amount is more than 10% by weight, the antistatic agent bleeds, resulting in a decrease in durability.

A curing step is preferably provided after applying the adhesive. This curing step is a step of curing the pressure-sensitive adhesive, but it also has the effect of further curing and stabilizing the adhesive layer formed between the polarizing element and the protective film. This curing step is carried out 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, but if the curing period is too long, the productivity will deteriorate. Further, the pressure-sensitive adhesive layer-attached polarizing plate of the present invention may be cut according to the size of the liquid crystal panel to be 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 comprises a liquid crystal cell and the polarizing plate with an adhesive layer of the present invention disposed on at least one side of the liquid crystal cell, and is bonded to the liquid crystal cell by the adhesive layer of the polarizing plate. It is characterized by

(Composition of a general liquid crystal display device)
A liquid crystal display device comprises a liquid crystal cell holding a liquid crystal between two electrode substrates, two polarizing plates disposed on both sides of the cell, and optionally between the liquid crystal cell and the polarizing plates. It has a structure in which at least one optical compensation film is arranged.
A 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. A transparent electrode layer is formed on a substrate as a transparent film containing a conductive material. The liquid crystal cell may further have a gas barrier layer, a hard coat layer or an undercoat layer (used for adhering the transparent electrode layer). These layers are typically provided on a substrate. The substrates of liquid crystal cells generally have a thickness of 50 μm to 2 mm.

(Type of liquid crystal display device)
The film of the present invention can be used in liquid crystal cells of various display modes. TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), AFLC (Anti-Ferroelectric Liquid Crystal), OCB (Optically Compensatory Bend), STN (Super Twisted Nematic), VA (Vertically Aligned), ECB ( Various display modes have been proposed, such as Electrically Controlled Birefringence) and HAN (Hybrid Aligned Nematic). Further, a display mode in which the above display mode is divided in orientation has also been proposed. The polarizing plate of the present invention is effective in liquid crystal display devices of any display mode. Also, it can be used in any of transmissive, reflective, and transflective liquid crystal display devices.

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

The present invention will be specifically described based on examples below. The materials, reagents, amounts and ratios of substances, operations, etc. shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Accordingly, the present invention is limited and not restricted to the following examples.
First, the present invention will be described with an example of the following layer structure having a transparent protective film only on one side of a polarizing element.
Transparent protective film (PF1)/polarizing element (P)/curing layer (BL1)/adhesive layer

(Fabrication of polarizing element)
A PVA film having an average degree of polymerization of 2400 and a degree of saponification of 99.9 mol % and having a film thickness of 40 μm was immersed in hot water at 25° C. for 120 seconds to swell. Then, the PVA film was dyed while being 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 with a film thickness of 15 μm.

(Preparation of Adhesive for Polarizing Plate)
A modified PVA-based resin containing an acetoacetyl group (Gohsenex Z-410, manufactured by Nippon Synthetic Chemical Co., Ltd.) was dissolved in water to prepare an aqueous solution A adjusted to a solid concentration of 3%. Then, maleic acid was added to the aqueous solution A so as to be 0.5% by weight, and then glyoxal was added as a cross-linking agent. The amount of glyoxal added was 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 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 passed through a washing bath under running water for 30 seconds to neutralize the film. Then, water was removed by an air knife three times, and after water was removed, the film was dried by staying in a drying zone at 70° C. for 15 seconds to prepare a saponified film.

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

[Preparation of active energy ray-curable polymer composition for forming cured layer]
Hereinafter, a method for preparing an aqueous solution of an active energy ray-curable polymer composition (hereinafter also referred to as a composition for forming a cured layer) that forms a cured layer will be described. 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 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

Pure water was added to the above formulation so that the solid content concentration was 35% by weight, mixed, irradiated with ultrasonic waves, and passed through a filter with a pore size of 5 μm to prepare a composition for forming a cured layer (BLC-1). .
Cured layer-forming compositions BLC-2 to BLC-8 were prepared in the same manner as the cured layer-forming composition BLC-1. Table 1 shows the proportion of each composition. Table 1 shows the content mass ratio of the solid content of each component. Here, the solid content is the composition excluding the solvent (in BLC-1, water: including that contained in UCECOAT 7571).

The materials used in Table 1 are shown below.
UCECOAT 7571: Water-dispersible polyurethane (meth)acrylate (UV Curable 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 a polyurethane structure that is 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
・Viscoat #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) [manufactured by Arakawa Chemical Industries, Ltd.] viscosity: 500 (mPa s / 25 ° C.), acrylic equivalent: 88.0

・ BS-730: Ditrimethylolpropane tetraacrylate [manufactured by 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)

(Preparation of single-sided polarizing plate with cured layer)
Using a bar coater on the polarizer of the single-sided polarizing plate prepared above, the composition for forming a cured layer (BLC-1) was applied so that the film thickness after drying was 2.5 μm, and then at 60 ° C. Allow to dry for 10 minutes. Thereafter, an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) with an output of 160 W/cm at atmospheric pressure is used to irradiate ultraviolet rays with an illuminance of 400 mW/cm ² and an irradiation dose of 500 mJ/cm ² to cure the coating layer. A single-sided polarizing plate with a cured 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 cured layer-forming composition and the thickness of the cured layer were changed as shown in Table 1. In the single-sided polarizing plates 13 and 14, no cured layer was laminated on the polarizing element.

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

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

(Preparation of polarizing plates 2 to 14 with adhesive layer)
Polarizing plate 1 with an adhesive layer except that the type of cured layer forming composition, the thickness of the cured layer, and the type of adhesive composition were changed to those shown in Table 2 with respect to polarizing plate 1 with an adhesive layer Adhesive layer-attached polarizing plates 2 to 14 were obtained in the same manner as above.
The adhesive layer-attached polarizing plates 13 and 14 do not have a hardened layer, and the adhesive layer is laminated directly on the polarizing element.

(Damp heat durability test)
The pressure-sensitive adhesive polarizing plate prepared above was cut into a size of 35 mm × 35 mm, the release film was peeled off, and a glass plate of 50 mm × 50 mm with a thickness of 1 mm was laminated on one side using a laminator roll. It was held in an autoclave for 20 minutes under atmospheric pressure to obtain a test piece. Two test pieces were prepared for each level.
The prepared test piece was placed under conditions of 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 the application was measured using V7100 manufactured by JASCO Corporation, and the change in degree of polarization ΔPE was calculated according to the following formula.

Amount of change in degree of polarization ΔPE = (degree of polarization before input) - (degree of polarization after input)
The degree of polarization was calculated according to the following method.
The transmittance (Tp) when the two prepared polarizing plates are superimposed with the absorption axes parallel to each other and the transmittance (Tc') when the absorption axes are superimposed at right angles are measured, and the degree of polarization is calculated from the following formula. (PE) was calculated.
Degree of polarization PE = ((Tp-Tc')/(Tp+Tc')) ^0.5 × 100 [%]
In the present invention, ΔPE after the wet heat durability test must 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)
After peeling off the PET release film of the adhesive polarizing plate, the surface resistance value of the adhesive layer surface was measured using a super insulation resistance/micro current meter TR8601 (manufactured by Advantest Co., Ltd.), and the surface resistance value (Ω/□ ) in common logarithm (logSR). The lower the logSR, the better the antistatic properties. In the present invention, it is necessary to be 14.0 or less, and 13.0 or less is more preferable.

The results shown in Table 1 reveal the following.
1. Adhesive containing an antistatic agent 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, as a main component, a polymer compound having an ethylenically unsaturated group of the present invention The adhesive-attached polarizing plate laminated with the agent layer does not lower the degree of polarization after the wet heat durability test, and has good durability against heat and humidity.
2. When the active energy ray-curable composition is mainly composed of a polymer compound having an ethylenically unsaturated group and further contains a polyfunctional (meth)acrylate compound, the decrease in the degree of polarization after the heat and humidity durability test is less, and the heat and humidity resistance is more durable. It also has good properties.

Next, an example in which an adhesion enhancer is used in the cured layer-forming composition will be shown.
(Preparation of cured layer forming composition BLC-9)
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.

(Solid content composition of cured layer forming composition BLC-9)
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 cured layer forming composition BLC-9)
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-vinylphenyl boronic acid: reagent [manufactured by Tokyo Chemical Industry Co., Ltd.]
・ Boronic acid compound A: See the chemical formula below

(Preparation of polarizing plates 15 and 16 with adhesive and evaluation of polarizing plates 15 and 16)
Adhesive-attached polarizing plates 15 and 16 were prepared in the same manner as in the adhesive layer-attached polarizing plate 1, except that the cured layer-forming compositions were changed to (BLC-9) and (BLC-10).
Polarizing plates 15 and 16 with adhesive were evaluated in the same manner as in polarizing plate 1 with adhesive, except that polarizing plate 22 or polarizing plate 23 was used. Table 2 shows the results.

From the results shown in Table 2, it is clear that even when a boronic acid compound is used as an 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 durability is good.

Next, the present invention will be described using the following two layer structures having transparent protective films on both sides of a polarizing element as an example.
Transparent protective film (PF1)/polarizing element (P)/hardening layer (BL1)/transparent protective film (PF2)/adhesive layer Transparent protective film (PF1)/hardening layer (BL2)/polarizing element (P)/hardening layer (BL1) / transparent protective film (PF2) / adhesive layer

(Preparation of cellulose acylate film containing no ultraviolet absorber)
With reference to paragraphs [0160] to [0163] of JP-A-2012-177894, a UV absorber-free cellulose resin having a film thickness of 20 μm was prepared in the same manner except that the flow rate was adjusted so that the thickness of the main stream was 14 μm. A rate film (CA-1) was produced.

(Saponification of cellulose acylate film CA-1)
A saponified cellulose acylate film (CA-1) was prepared 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.

(Production of polarizing plate 21)
A polarizing element was produced in the same manner as in Example 1 above.
A polarizing plate adhesive was applied to one side of the saponified cellulose acylate film TD60 so that the thickness after drying was 80 nm, and at the same time, a curable composition ( BLC-6) is applied so that the thickness after drying is 2.5 μm, and the polarizing element is bonded through the polarizing plate adhesive and the curable composition (BLC-6) using a roll bonding machine. A saponified cellulose acylate film TD60 and a saponified cellulose acylate film (CA-1) were laminated on both sides.

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

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

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

(Preparation of polarizing plate 21 with adhesive layer)
A pressure-sensitive adhesive layer was applied on the release-treated PET release 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 allowed to stand at 23° C. and 65% humidity for 7 days to obtain a polarizing plate 21 with an adhesive layer. The thickness of the adhesive layer was 15 µm.

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

(Evaluation of adhesive-attached polarizing plates 21 to 23)
Polarizing plates 21 to 23 with an adhesive layer were evaluated in the same manner as the polarizing plate 1 with an adhesive layer. Table 2 shows the results.

The results shown in Table 3 clearly show the following.
1. In the adhesive-attached polarizing plate having transparent protective films on both sides and laminated with an antistatic agent-containing adhesive layer, 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, there is no decrease in the degree of polarization after the wet heat durability test, and the wet heat durability is also good.

Claims (12)

A polarizing element (P) formed by adsorbing and orienting iodine on a polyvinyl alcohol-based resin layer is provided with a transparent protective film (PF1) on one side, and a cured layer (BL1) and an antistatic agent-containing pressure-sensitive adhesive on the other side. A polarizing plate with an adhesive layer provided with a layer,
The cured layer (BL1) has an average thickness of 2.5 to 10 μm, is mainly composed of a polymer compound having an ethylenically unsaturated group, and contains an active energy containing a boronic acid compound having an ethylenically unsaturated group. formed from an aqueous solution of a linearly curable polymer composition,
At least part of the polymer compound having an ethylenically unsaturated group is a self-emulsifying emulsion,
A polarizing plate with an adhesive layer, wherein the boronic acid compound having an ethylenically unsaturated group is 4-vinylphenylboronic acid or a boronic acid compound represented by the following formula.

A polarizing element (P) formed by adsorbing and orienting iodine on a polyvinyl alcohol-based resin layer is provided with a transparent protective film (PF1) on one side, and a cured layer (BL1) and an antistatic agent-containing pressure-sensitive adhesive on the other side. A polarizing plate with an adhesive layer provided with a layer,
The cured layer (BL1) has an average thickness of 2.5 to 10 μm, is mainly composed of a polymer compound having an ethylenically unsaturated group, and contains an active energy containing a boronic acid compound having an ethylenically unsaturated group. formed from an aqueous solution of a linearly curable polymer composition,
Between the transparent protective film (PF1) and the polarizing element (P), a cured layer (BL2) having a thickness of 0.5 to 10 μm and having the same composition as the cured layer (BL1) is provided. ,
A polarizing plate with an adhesive layer, wherein the boronic acid compound having an ethylenically unsaturated group is 4-vinylphenylboronic acid or a boronic acid compound represented by the following formula.

3. The pressure-sensitive adhesive layer-carrying polarizing plate according to claim 1, wherein the polymer compound having ethylenically unsaturated groups is a self-emulsifying emulsion in which at least a portion thereof is 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 solid in the aqueous solution of the active energy ray-curable polymer composition. 4. The pressure-sensitive adhesive layer-attached polarizing plate according to claim 1, wherein the polarizing plate is 1 to 40% by weight based on the weight of the adhesive layer. Claims 1 to 4, characterized in that 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. The polarizing plate with an adhesive layer according to any one of . 6. The pressure-sensitive adhesive layer-attached polarizing plate according to claim 1, wherein the polymer compound having ethylenically unsaturated groups has a number average molecular weight of 5,000 to 100,000. 2. The pressure-sensitive adhesive layer is provided directly or via a transparent protective film (PF2) on the opposite side of the polarizing element (P) of the cured layer (BL1) of the polarizing plate. 7. The polarizing plate with an adhesive layer according to any one of 6. 8. The pressure-sensitive adhesive layer-attached polarizing plate according to claim 7, wherein the transparent protective film (PF2) is a cellulose acylate film having a thickness of 10 to 50 μm. 9. The polarizing plate with an adhesive layer according to claim 1, wherein the 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 9 is adhered to at least one side of a liquid crystal cell. 10. The active energy ray-curable polymer composition used for producing the polarizing plate according to any one of claims 1 to 9, wherein when an aqueous solution is prepared, the polymer compound having an ethylenically unsaturated group is added to the aqueous solution. An active energy ray-curable polymer composition containing 50 to 99% by weight of the solid content and 1 to 40% by weight of the polyfunctional (meth)acrylate compound in the solid content of the aqueous solution. A step of laminating a transparent protective film (PF1) only on one side of a polarizing element (P) formed by adsorbing and aligning iodine on a polyvinyl alcohol-based resin layer to form a single-sided polarizing plate;
applying an aqueous solution of an active energy ray-curable polymer composition containing water as a main solvent onto the polarizing element of the single-sided polarizing plate;
After drying the applied aqueous solution of the active energy ray-curable polymer composition, a step of irradiating an active energy ray under normal atmosphere under atmospheric pressure to form a cured layer, and an antistatic agent-containing pressure-sensitive adhesive layer. 10. The method for producing a polarizing plate with an adhesive layer according to any one of claims 1 to 9, comprising the step of providing.