JP5426505B2 - Active energy ray-curable resin composition, adhesive layer, polarizing plate, optical film, and image display device - Google Patents

Description

  The present invention relates to an active energy ray-curable resin composition for forming an adhesive layer for adhering two or more members, particularly an active energy ray-curable resin composition for forming an adhesive layer of a polarizer and a transparent protective film. , And a polarizing plate. The polarizing plate can form an image display device such as a liquid crystal display device (LCD), an organic EL display device, a CRT, or a PDP alone or as an optical film in which the polarizing plate is laminated.

  Liquid crystal display devices are rapidly expanding in watches, mobile phones, PDAs, notebook computers, personal computer monitors, DVD players, TVs, and the like. The liquid crystal display device visualizes the polarization state by switching of the liquid crystal, and a polarizer is used from the display principle. In particular, in applications such as TVs, higher brightness, higher contrast, and wider viewing angles are required, and polarizing plates are also required to have higher transmittance, higher degree of polarization, and higher color reproducibility.

  As the polarizer, since it has a high transmittance and a high degree of polarization, for example, an iodine-based polarizer having a stretched structure by adsorbing iodine to polyvinyl alcohol (hereinafter also simply referred to as “PVA”) is most widely used. It is used. In general, a polarizing plate is used in which a transparent protective film is bonded to both surfaces of a polarizer with a so-called aqueous adhesive in which a polyvinyl alcohol-based material is dissolved in water (Patent Document 1 and Patent Document 2 below). ). As the transparent protective film, triacetyl cellulose having a high moisture permeability is used.

  When manufacturing a polarizing plate, when a water-based adhesive such as a polyvinyl alcohol-based adhesive is used (so-called wet lamination), a drying step is required after the polarizer and the transparent protective film are bonded together. . In order to improve the productivity of the polarizing plate, it is desirable to shorten the drying process or adopt another bonding method that does not require the drying process.

  In addition, when using a water-based adhesive, in order to enhance the adhesion with the polarizer, the water content of the polarizer must be relatively high (usually the water content of the polarizer is about 30%). A polarizing plate with good adhesion cannot be obtained. However, the polarizing plate thus obtained has problems such as large dimensional change under high temperature and high temperature and high humidity. On the other hand, in order to suppress a dimensional change, the moisture content of a polarizer can be reduced or a transparent protective film with low moisture permeability can be used. However, when such a polarizer and a transparent protective film are bonded together using a water-based adhesive, drying efficiency decreases, polarization characteristics decrease, or appearance defects occur, and a substantially useful polarizing plate is obtained. I can't.

  In addition, as represented by TVs in particular, as the screen size of image display devices has increased in recent years, it has become very important to increase the size of polarizing plates in terms of productivity and cost (yield and increase in number of products). Yes. However, in the polarizing plate using the water-based adhesive described above, the so-called light leakage (unevenness) that the polarizing plate causes a dimensional change due to the heat of the backlight and becomes uneven and the black display appears white in a part of the entire screen. ) Becomes prominent.

  In order to solve the above-described problems in wet lamination, an active energy ray-curable adhesive that does not contain water or an organic solvent has been proposed. Such an active energy ray-curable adhesive is roughly classified into a photocationic polymerization type and a photoradical polymerization type.

  Photocationic polymerization is generally known to inhibit the polymerization reaction in the presence of water. Therefore, there is no problem when the wet-stretched PVA polarizer is completely dried and the curable component in the adhesive is polymerized. However, when the transparent protective film is laminated through the adhesive layer in a state where the PVA polarizer is not sufficiently dried and the water content is high, the photocationic polymerization of the curable component is inhibited, and the adhesive layer causes poor curing. There is a case. In addition, as described in Patent Document 3 below, when the curable component is composed of an epoxy resin, the polymerization rate of the cationic photopolymerization is slow, and the polarizing plate is produced continuously by roll-to-roll (Roll To Roll). Curing may progress even after winding, and curling may occur in the polarizing plate. For this reason, the photo cationic polymerization type is not suitable for roll-to-roll production of polarizing plates. In addition, many low-molecular-weight and low-viscosity epoxy resins commonly used in the cationic photopolymerization type have toxic properties such as mutagenicity and irritation, and problems have been pointed out in terms of safety. .

  On the other hand, in the photo-radical polymerization type, the polymerization reaction is not inhibited by water. Therefore, there is no problem even if the transparent protective film is laminated through the adhesive layer in a state where the moisture content of the PVA polarizer is high. Moreover, since the polymerization rate of radical photopolymerization is faster than that of photocationic polymerization, it is suitable for roll-to-roll production of polarizing plates. Moreover, the toxicity of the curable component used in the radical photopolymerization type is lower than that of the epoxy resin.

  The present inventors have developed a radical polymerization type active energy ray curable adhesive using an N-substituted amide monomer as a curable component (Patent Document 4 below). Such an adhesive exhibits excellent durability under harsh environments under high humidity and high temperature. However, in the market, there is a demand for an adhesive that can further improve adhesiveness and / or water resistance. There was a real situation.

JP 2006-220732 A JP 2001-296427 A Japanese Patent No. 4306270 JP 2008-287207 A

  The present invention has been made in view of the above circumstances, and its purpose is to improve adhesion between two or more members, particularly a polarizer and a transparent protective film layer, and to improve durability and water resistance. The object is to provide an active energy ray-curable resin composition, a polarizing plate, an optical film and an image display device capable of forming an agent layer.

The above object can be achieved by the present invention as described below. That is, the active energy ray-curable resin composition according to the present invention has the following general formula (1) as a curable component:
^{_{CH 2 = C (R 1)}} -CONH 2-m - (X-O-R 2) m (1)
(R ¹ represents a hydrogen atom or a methyl group, X represents a —CH ₂ — group or a —CH ₂ CH ₂ — group, R ² represents a — (CH ₂ ) _n —H group (where n is 0, 1 Or 2), m represents 1 or 2), and an acid in which a (meth) acryloyl group and an acid group are bonded via an organic group having 1 to 10 carbon atoms It contains a group-containing (meth) acrylate monomer. In the present invention, the (meth) acrylate group means an acrylate group and / or a methacrylate group.

  In the active energy ray-curable resin composition, the organic group is preferably a (poly) alkylene oxide group.

  In the active energy ray-curable resin composition, the acid group is preferably a phosphate group.

In the active energy ray-curable resin composition, the acid group-containing (meth) acrylate monomer is represented by the following general formula (2):
^{_{(CH 2 = C (R 3}} ) -COO-Y) r -PO- (OH) 3-r (2)
(R ³ represents a hydrogen atom or a methyl group, Y represents — (CH ₂ CHR ⁴ —O) _s — (where R ⁴ represents a hydrogen atom, a methyl group or a chloromethyl group, and s represents 1 to 6). It is preferable that the phosphoric acid group-containing (meth) acrylate-based monomer represented by (), (wherein r represents 1, 2 or 3).

  In the active energy ray-curable resin composition, the ratio of the acid group-containing (meth) acrylate monomer to the total amount of monomers constituting the curable component is 0.01% by mass or more and less than 10% by mass. preferable.

  The active energy ray-curable resin composition preferably further contains a monomer having two or more carbon-carbon double bonds.

  In addition, the adhesive layer according to the present invention is formed by a cured product layer of the active energy ray-curable resin composition described in any one of the above.

  In the adhesive layer, the glass transition temperature (Tg) is preferably 60 ° C. or higher.

  The polarizing plate according to the present invention is a polarizing plate in which a transparent protective film is provided on at least one surface of a polarizer via an adhesive layer, and the adhesive layer is any one of the above. It is formed by the hardened | cured material layer of an active energy ray hardening-type resin composition, It is characterized by the above-mentioned.

  In the polarizing plate, the adhesive layer preferably has a glass transition temperature (Tg) of 60 ° C. or higher.

  Moreover, the optical film according to the present invention is characterized in that at least one polarizing plate as described above is laminated.

  Furthermore, the image display device according to the present invention is characterized by using any of the polarizing plates described above and / or the optical film described above.

  The active energy ray-curable resin composition according to the present invention has higher durability than a water-based adhesive. Moreover, since it is a radical photopolymerization type | mold, compared with a photocationic polymerization type | mold, a polymerization rate is quick and it is excellent in productivity. Moreover, since it contains an N-substituted amide monomer and an acid group-containing (meth) acrylate monomer as a curable component, it is excellent in adhesiveness, durability and water resistance.

  In the active energy ray-curable resin composition according to the present invention, an acid group in which a (meth) acrylate group and an acid group are bonded via an organic group having 1 to 10 carbon atoms, preferably a (poly) alkylene oxide group. Since the containing (meth) acrylate monomer is contained, particularly the adhesiveness is remarkably improved. The reason for this effect is not clear, but by interposing an organic group having 1 to 10 carbon atoms between the polymerization main chain of (meth) acrylate and the acid group, the organic group functions as a spacer. As a result, it is presumed that the acid group easily interacts with two members to be bonded, such as a polarizer and a protective film. Therefore, as shown by the results to be described later, when acrylic acid or the like in which no spacer is interposed between the (meth) acryloyl group and the acid group is used, the adhesion cannot be improved to the same level as in the present invention.

When a phosphoric acid group-containing (meth) acrylate monomer is used as the acid group-containing (meth) acrylate monomer, the following general formula (2) is particularly preferable:
^{_{(CH 2 = C (R 3}} ) -COO-Y) r -PO- (OH) 3-r (2)
(R ³ represents a hydrogen atom or a methyl group, Y represents — (CH ₂ CHR ⁴ —O) _s — (where R ⁴ represents a hydrogen atom, a methyl group or a chloromethyl group, and s represents 1 to 6). ), A phosphoric acid group-containing (meth) acrylate monomer represented by (2) is used, and two phosphoric acid groups are present. Adhesion is further improved by hydrogen bonding (interaction) with a member such as a polarizer and a protective film.

  In the present invention, the ratio of the acid group-containing (meth) acrylate monomer to the total amount of monomers constituting the curable component is preferably 0.01% by mass or more and less than 10% by mass. By setting to such a ratio, the adhesiveness, durability, and water resistance of the adhesive layer can be improved in a well-balanced manner.

  In addition to the N-substituted amide monomer and the acid group-containing (meth) acrylate monomer as the curable component, a monomer having two or more carbon-carbon double bonds, particularly preferably a polyfunctional (meth) acrylate When the monomer is contained, the water resistance of the adhesive layer is particularly improved. As described above, when an acid group-containing (meth) acrylate-based monomer is contained, the adhesiveness of the adhesive layer is improved, but the amount of moisture absorption tends to increase because the polarity increases. However, when the composition forming the adhesive layer contains a monomer having two or more carbon-carbon double bonds, particularly preferably a polyfunctional (meth) acrylate monomer, the moisture absorption amount of the adhesive layer is moderate. The water resistance can be improved while improving the adhesion. In order to further improve the water resistance, it is more preferable to use a hydrophobic polyfunctional (meth) acrylate monomer.

  The adhesive layer according to the present invention is formed by the cured product layer of the active energy ray-curable resin composition described above. Such an adhesive layer is excellent in adhesiveness, durability and water resistance. It is preferable that the Tg of the adhesive layer is 60 ° C. or higher because durability is particularly excellent.

  In the polarizing plate according to the present invention, the polarizer and the transparent protective film are firmly bonded via the adhesive layer, and the adhesive layer is excellent in durability and water resistance. In particular, when the Tg of the adhesive layer is 60 ° C. or higher, more preferably 70 ° C. or higher, particularly preferably 90 ° C. or higher, the durability is particularly excellent, and the occurrence of heat shock cracks can be prevented. Here, the term “heat shock crack” means a phenomenon in which when the polarizer contracts, it tears in the stretching direction, and in order to prevent this, the polarizer is in the heat shock temperature range (−40 ° C. to 60 ° C.). It is important to suppress the expansion / contraction of the material. As described above, when the Tg of the adhesive layer is 60 ° C. or higher, it is possible to suppress a rapid change in elastic modulus of the adhesive layer in the heat shock temperature range and to reduce the expansion / contraction force acting on the polarizer. Therefore, the occurrence of heat shock cracks can be prevented.

  When the adhesive layer according to the present invention is provided, a polarizing plate with a small dimensional change can be produced, so that it is possible to easily cope with an increase in the size of the polarizing plate, and it is possible to suppress the production cost from the viewpoint of yield and number of production. Further, since the polarizing plate according to the present invention has good dimensional stability, it is possible to suppress the occurrence of unevenness in the image display device due to the external heat of the backlight.

  The active energy ray-curable resin composition according to the present invention includes, as essential components, an N-substituted amide monomer represented by the following general formula (1) and an acid group-containing (meth) acrylate monomer as curable components. contains. In the polarizing plate according to the present invention, a transparent protective film is provided on at least one surface of a polarizer via an adhesive layer, and an active energy ray-curable resin composition is used for forming the adhesive layer. Use.

The N-substituted amide monomer is represented by the following general formula (1):
^{_{CH 2 = C (R 1)}} -CONH 2-m - (X-O-R 2) m (1)
(R ¹ represents a hydrogen atom or a methyl group, X represents a —CH ₂ — group or a —CH ₂ CH ₂ — group, R ² represents a — (CH ₂ ) _n —H group (where n is 0, 1 Or 2) represents a methyl group or an ethyl group, and m represents 1 or 2.

  Specific examples of the N-substituted amide monomer include, for example, N-hydroxyethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N -Methoxyethyl (meth) acrylamide, N-ethoxyethyl (meth) acrylamide, etc. are mentioned. These N-substituted amide monomers can be used singly or in combination of two or more.

  As the N-substituted amide monomer, commercially available products can also be suitably used. Specifically, for example, N-hydroxyethylacrylamide (trade name “HEAA”, manufactured by Kojin Co., Ltd.), N-methoxymethyl acrylamide (trade name “Wasmer 2MA”, manufactured by Kasano Kosan Co., Ltd.), N-ethoxymethylacrylamide (product) Name “Wasmer EMA” (manufactured by Kasano Kosan Co., Ltd.), N-methoxymethylmethacrylamide (trade name “Wasmer 2MA”, manufactured by Kasano Kosan Co., Ltd.), and the like.

  As the N-substituted amide monomer, N-hydroxyethyl (meth) acrylamide and N-methoxymethyl (meth) acrylamide are preferable. The N-substituted amide-based monomer exhibits good adhesion to a transparent protective film using a low moisture content polarizer or a material with low moisture permeability. Among the monomers exemplified above, N- Hydroxyethyl acrylamide exhibits particularly good adhesion. On the other hand, N-methoxymethyl acrylamide does not contribute much to the improvement of adhesive strength, but when N-hydroxyethyl acrylamide and a hydrophobic polyfunctional (meth) acrylate monomer are used in combination, they have an effect of compatibilizing them. Play. Therefore, a combined system of N-hydroxyethyl acrylamide and N-methoxymethyl (meth) acrylamide is preferable in consideration of adhesiveness and durability.

  In the present invention, when adhesiveness and water resistance are taken into consideration, the ratio of the N-substituted amide monomer represented by the general formula (1) to the total amount of monomers constituting the curable component is 50 to 99 masses. % Is preferable, and 60 to 90% by mass is more preferable.

In the acid group-containing (meth) acrylate monomer, the (meth) acryloyl group and the acid group are organic groups having 1 to 10 carbon atoms, particularly preferably — (CH ₂ CHR ⁴ —O) _s — (where R ⁴ represents a hydrogen atom, a methyl group or a chloromethyl group, and s represents an integer of 1 to 6), and is a monomer bonded via a (poly) alkylene oxide group. In the present invention, examples of the “acid group” include a phosphoric acid group, a sulfonic acid group, and a carboxylic acid group, and among these, a phosphoric acid group is preferable.

In the present invention, as the acid group-containing (meth) acrylate monomer, the following general formula (2):
^{_{(CH 2 = C (R 3}} ) -COO-Y) r -PO- (OH) 3-r (2)
(R ³ represents a hydrogen atom or a methyl group, Y represents — (CH ₂ CHR ⁴ —O) _s — (wherein R ⁴ represents a hydrogen atom, a methyl group or a chloromethyl group, and s represents 1 to 6) A phosphoric acid group-containing (meth) acrylate monomer represented by (poly) alkylene oxide group represented by (indicating an integer), and r represents 1, 2 or 3.

Specific examples of phosphoric acid group-containing (meth) acrylate monomers include, for example:
_{(CH 2 = CH-COO-} CH 2 CH 2 O) -PO- (OH) 2,
_{(CH 2 = CH-COO-} CH 2 CH 2 O) 2 -PO-OH,
_{(CH 2 = CH-COO-} CH 2 CH 2 O) 3 -PO,
_{(CH 2 = CCH 3 -COO-} CH 2 CH 2 O) -PO- (OH) 2,
_{(CH 2 = CCH 3 -COO- (} CH 2 CH 2 O) q) -PO- (OH) 2 ( However, q is 4 or 5),
_{(CH 2 = CCH 3 -COO- (} CH 2 CH (CH 3) O) q) -PO- (OH) 2 ( However, q is 5 or 6),
_{(CH 2 = CCH 3 -COO- (} CH 2 CH (-CH 2 Cl) O)) - PO- (OH) 2,
Or the phosphate of these monomers and monoethanolamine etc. is mentioned, for example.

  Commercially available products can also be suitably used as the phosphate group-containing (meth) acrylate monomer. For example, “Light Acrylate P-1A” (Kyoeisha Chemical), “Biscoat 3PA” (Osaka Organic Chemical Industry), “Phosmer M” ”(Unichemical),“ Phosmer MH ”(Unichemical),“ Phosmer PE ”(Unichemical),“ Phosmer PP ”(Unichemical),“ Phosmer CL ”(Unichemical), and the like.

  In the present invention, the ratio of the acid group-containing (meth) acrylate monomer to the total amount of monomers constituting the curable component is preferably 0.01% by mass or more and less than 10% by mass, and 0.1% by mass. More preferably, it is less than 5% by mass.

  In the present invention, in addition to the N-substituted amide monomer represented by the general formula (1) and the acid group-containing (meth) acrylate monomer as the curable component, it has two or more carbon-carbon double bonds. A monomer, particularly preferably a polyfunctional (meth) acrylate monomer, is preferable because the water resistance of the adhesive layer is improved. In consideration of the water resistance of the adhesive layer, the monomer having two or more carbon-carbon double bonds is more preferably hydrophobic. Monomers having two or more hydrophobic carbon-carbon double bonds, particularly hydrophobic polyfunctional (meth) acrylate monomers include, for example, tricyclodecane dimethanol diacrylate, divinylbenzene, N, N′-methylene. Bisacrylamide, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) Acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol glycol di (meth) acrylate, glycerin di (meth) acrylate, EO modified glycerin tri (meth) acrylate, EO modified diglycerin tetra ( (Meth) acrylate, (meth) acrylic acid 2- (2-vinyloxyethoxy) ethyl, bisphenol A-EO adduct di (meth) acrylate, trimethylolpropane tri (meth) acrylate, hydroxypivalate neopentyl glycol (meth) Acrylic acid adduct, EO-modified trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, iso Anuric acid EO-modified di (meth) acrylate, isocyanuric acid EO-modified tri (meth) acrylate, ε-caprolactone-modified tris ((meth) acryloxyethyl) isocyanurate, 1,1-bis ((meth) acryloyloxymethyl) ethyl Examples include isocyanate, a polymer of 2-hydroxyethyl (meth) acrylate and 1,6-diisocyanate hexane, 9,9-bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene, and the like.

  In this invention, it is preferable that the ratio of the monomer which has a 2 or more carbon-carbon double bond with respect to the total amount of the monomer which comprises a sclerosing | hardenable component is 5-50 mass%, and is 9-40 mass%. More preferably. When this proportion is less than 5% by mass, sufficient water resistance may not be obtained. On the other hand, when it exceeds 50% by mass, sufficient adhesion may not be obtained.

  In the present invention, an N-substituted amide monomer represented by the general formula (1) and an acid group-containing (meth) acrylate monomer as long as the curable component does not impair adhesiveness, durability and water resistance. Other monomers other than the monomer having two or more carbon-carbon double bonds can be used in combination. Examples of such monomers include N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropylacrylamide, N-butyl (meth) acrylamide, N -Hexyl (meth) acrylamide, aminomethyl (meth) acrylamide, aminoethyl (meth) acrylamide, mercaptomethyl (meth) acrylamide, mercaptoethyl (meth) acrylamide, N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine N-substituted amide monomers other than those represented by the general formula (1) such as N-acryloylpyrrolidine, N-vinylformamide, N-vinylacetamide, and N-vinyl-2-caprolactam.

  Moreover, you may use the monofunctional (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, etc. which have various aromatic rings and hydroxy groups as an arbitrary component.

  As the monofunctional (meth) acrylate having an aromatic ring and a hydroxy group, various monofunctional (meth) acrylates having an aromatic ring and a hydroxy group can be used. The hydroxy group may exist as a substituent of the aromatic ring, but in the present invention, it exists as an organic group (bonded to a hydrocarbon group, particularly an alkylene group) that bonds the aromatic ring and the (meth) acrylate. Those that do are preferred.

  Examples of the monofunctional (meth) acrylate having an aromatic ring and a hydroxy group include a reaction product of a monofunctional epoxy compound having an aromatic ring and (meth) acrylic acid. Examples of the monofunctional epoxy compound having an aromatic ring include phenyl glycidyl ether, t-butylphenyl glycidyl ether, and phenyl polyethylene glycol glycidyl ether. Specific examples of the monofunctional (meth) acrylate having an aromatic ring and a hydroxy group include, for example, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxy-3-t-butylphenoxypropyl (meth) Acrylate, 2-hydroxy-3-phenyl polyethylene glycol propyl (meth) acrylate, etc. are mentioned.

  Moreover, as said urethane (meth) acrylate, the hydroxyl group of the one end of diol compounds, such as (meth) acrylate which has an isocyanate group, and polyalkylene glycols, such as polyurethane diol, polyester diol, polyether diol, polyethylene glycol, polypropylene glycol, etc. And a reaction product thereof.

  Moreover, various additives can be mix | blended with the active energy ray hardening-type resin composition which concerns on this invention as another arbitrary component in the range which does not impair the objective and effect of this invention. Such additives include epoxy resin, polyamide, polyamideimide, polyurethane, polybutadiene, polychloroprene, polyether, polyester, styrene-butadiene block copolymer, petroleum resin, xylene resin, ketone resin, cellulose resin, fluorine-based oligomer, Polymers or oligomers such as silicone oligomers and polysulfide oligomers; polymerization inhibitors such as phenothiazine and 2,6-di-t-butyl-4-methylphenol; polymerization initiation aids; leveling agents; wettability improvers; Plasticizer; UV absorber; Silane coupling agent; Inorganic filler; Pigment;

  The active energy ray-curable resin composition according to the present invention can be used in an electron beam curable type or an ultraviolet curable type.

  In the electron beam curable type, any appropriate condition can be adopted as the irradiation condition of the electron beam as long as the active energy ray curable resin composition can be cured. For example, in the electron beam irradiation, the acceleration voltage is preferably 5 kV to 300 kV, and more preferably 10 kV to 250 kV. If the acceleration voltage is less than 5 kV, the electron beam may not reach the adhesive and may be insufficiently cured. If the acceleration voltage exceeds 300 kV, the penetration force through the sample is too strong and damages the transparent protective film and the polarizer. There is a risk of giving. The irradiation dose is 5 to 100 kGy, more preferably 10 to 75 kGy. When the irradiation dose is less than 5 kGy, the adhesive becomes insufficiently cured, and when it exceeds 100 kGy, the transparent protective film and the polarizer are damaged, resulting in a decrease in mechanical strength and yellowing, thereby obtaining predetermined optical characteristics. I can't.

  Electron beam irradiation is usually performed in an inert gas, but if necessary, it may be performed in the atmosphere or under a condition in which a small amount of oxygen is introduced. Depending on the material of the transparent protective film, by appropriately introducing oxygen, the transparent protective film surface where the electron beam first hits can be obstructed to prevent oxygen damage and prevent damage to the transparent protective film. An electron beam can be irradiated efficiently.

  On the other hand, in the case of using a protective film imparted with ultraviolet absorbing ability in the ultraviolet curable type, light having a wavelength shorter than 380 nm is absorbed, so that light having a wavelength shorter than 380 nm does not reach the active energy ray curable resin composition. Therefore, it does not contribute to the polymerization reaction. Furthermore, light having a wavelength shorter than 380 nm absorbed by the protective film is converted into heat, and the protective film itself generates heat, causing defects such as curling and wrinkling of the polarizing plate. Therefore, when the ultraviolet curable type is adopted in the present invention, it is preferable to use an apparatus that does not emit light having a wavelength shorter than 380 nm as the ultraviolet ray generating apparatus, and more specifically, the integrated illuminance and wavelength in the wavelength range of 380 to 440 nm. The ratio with the integrated illuminance in the range of 250 to 370 nm is preferably 100: 0 to 100: 50, and more preferably 100: 0 to 100: 40. As the ultraviolet ray satisfying such a relationship of integrated illuminance, a gallium-filled metal halide lamp and an LED light source that emits light in the wavelength range of 380 to 440 nm are preferable. Alternatively, low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, incandescent lamp, xenon lamp, halogen lamp, carbon arc lamp, metal halide lamp, fluorescent lamp, tungsten lamp, gallium lamp, excimer laser or sunlight as the light source, It is also possible to use a light having a wavelength shorter than 380 nm by using a band pass filter.

  In the ultraviolet curable type, it is preferable to warm the active energy ray-curable resin composition before irradiation with ultraviolet rays (heating before irradiation), in which case it is preferable to heat to 40 ° C. or higher, and to 50 ° C. or higher. It is more preferable to heat. In addition, it is also preferable to warm the active energy ray-curable resin composition after irradiation with ultraviolet rays (heating after irradiation), in which case it is preferable to warm to 40 ° C. or higher, and warm to 50 ° C. or higher. More preferred.

  When the active energy ray curable resin composition is used as an electron beam curable type, it is not particularly necessary to include a photopolymerization initiator in the composition, but when used as an ultraviolet curable type, a photo radical generator is used. It is preferable to use it. Examples of the photo radical generator include a hydrogen abstraction type photo radical generator and a cleavage type photo radical generator.

  Examples of the hydrogen abstraction type photo radical generator include 1-methylnaphthalene, 2-methylnaphthalene, 1-fluoronaphthalene, 1-chloronaphthalene, 2-chloronaphthalene, 1-bromonaphthalene, 2-bromonaphthalene, 1-iodonaphthalene. , 2-iodonaphthalene, 1-naphthol, 2-naphthol, 1-methoxynaphthalene, 2-methoxynaphthalene, naphthalene derivatives such as 1,4-dicyanonaphthalene, anthracene, 1,2-benzanthracene, 9,10-dichloroanthracene , 9,10-dibromoanthracene, 9,10-diphenylanthracene, 9-cyanoanthracene, 9,10-dicyanoanthracene, 2,6,9,10-tetracyanoanthracene, anthracene derivatives, pyrene derivatives, carbazole 9-methylcarbazole, 9-phenylcarbazole, 9-prop-2-ynyl-9H-carbazole, 9-propyl-9H-carbazole, 9-vinylcarbazole, 9H-carbazole-9-ethanol, 9-methyl-3-nitro -9H-carbazole, 9-methyl-3,6-dinitro-9H-carbazole, 9-octanoylcarbazole, 9-carbazolemethanol, 9-carbazolepropionic acid, 9-carbazolepropionitrile, 9-ethyl-3,6 -Dinitro-9H-carbazole, 9-ethyl-3-nitrocarbazole, 9-ethylcarbazole, 9-isopropylcarbazole, 9- (ethoxycarbonylmethyl) carbazole, 9- (morpholinomethyl) carbazole, 9-acetylcarbazole, 9- Allyl Rubazole, 9-benzyl-9H-carbazole, 9-carbazoleacetic acid, 9- (2-nitrophenyl) carbazole, 9- (4-methoxyphenyl) carbazole, 9- (1-ethoxy-2-methyl-propyl) -9H -Carbazole, 3-nitrocarbazole, 4-hydroxycarbazole, 3,6-dinitro-9H-carbazole, 3,6-diphenyl-9H-carbazole, 2-hydroxycarbazole, 3,6-diacetyl-9-ethylcarbazole, etc. Carbazole derivatives, benzophenone, 4-phenylbenzophenone, 4,4'-bis (dimethoxy) benzophenone, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, methyl 2-benzoylbenzoate Ester, 2- Benzophenone derivatives such as methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 3,3′-dimethyl-4-methoxybenzophenone, 2,4,6-trimethylbenzophenone, aromatic carbonyl compounds, [4- (4-methyl Phenylthio) phenyl] -phenylmethanone, xanthone, thioxanthone, 2-chlorothioxanthone, 4-chlorothioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 1- Examples include thioxanthone derivatives such as chloro-4-propoxythioxanthone and coumarin derivatives.

  The cleavage type photo radical generator is a type of photo radical generator that generates radicals by cleavage of the compound upon irradiation with active energy rays. Specific examples thereof include arylalkyls such as benzoin ether derivatives and acetophenone derivatives. Examples include, but are not limited to, ketones, oxime ketones, acylphosphine oxides, S-phenyl thiobenzoates, titanocenes, and derivatives obtained by increasing the molecular weight thereof. Commercially available cleavage type photo radical generators include 1- (4-dodecylbenzoyl) -1-hydroxy-1-methylethane, 1- (4-isopropylbenzoyl) -1-hydroxy-1-methylethane, 1-benzoyl. -1-hydroxy-1-methylethane, 1- [4- (2-hydroxyethoxy) -benzoyl] -1-hydroxy-1-methylethane, 1- [4- (acryloyloxyethoxy) -benzoyl] -1-hydroxy- 1-methylethane, diphenyl ketone, phenyl-1-hydroxy-cyclohexyl ketone, benzyldimethyl ketal, bis (cyclopentadienyl) -bis (2,6-difluoro-3-pyryl-phenyl) titanium, (η6-isopropylbenzene) -(Η5-cyclopentadienyl) -iron (II) hexaf Fluorophosphate, trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxy-benzoyl)-(2,4,4-trimethyl-pentyl) -phosphine oxide, bis (2,4,6-trimethylbenzoyl) -2, 4-dipentoxyphenylphosphine oxide or bis (2,4,6-trimethylbenzoyl) phenyl-phosphine oxide, (4-morpholinobenzoyl) -1-benzyl-1-dimethylaminopropane, 4- (methylthiobenzoyl) -1 -Methyl-1-morpholinoethane may be mentioned, but is not limited thereto.

  The photoradical generator used in the present invention, that is, the hydrogen abstraction type or cleavage type photoradical generator can be used alone or in combination. Among these, a combination of one or more cleavage type photoradical generators is more preferable in terms of the stability of the composition and the curability of the composition in the present invention. Among the cleavage type photo radical generators, acylphosphine oxides are preferable. More specifically, trimethylbenzoyldiphenylphosphine oxide (trade name “DAROCURE TPO”; manufactured by Ciba Japan), bis (2,6-dimethoxy-benzoyl) )-(2,4,4-trimethyl-pentyl) -phosphine oxide (trade name “CGI 403”; manufactured by Ciba Japan) or bis (2,4,6-trimethylbenzoyl) -2,4-dipen Toxiphenylphosphine oxide (trade name “IRGACURE819”; manufactured by Ciba Japan Co., Ltd.) is preferable.

  When using a photoradical generator, the amount used is preferably 0.01 to 10 parts by mass, and 0.05 to 5 parts by mass with respect to the total amount of the active energy ray-curable resin composition. It is more preferable that the content is 0.1 to 3 parts by mass.

  Further, in the active energy ray-curable resin composition according to the present invention, in addition to the photo radical generator, a sensitizer that increases the curing rate and sensitivity of the electron beam represented by a carbonyl compound may be added. .

  Examples of the sensitizer include anthracene, phenothiazene, perylene, thioxanthone, and benzophenone thioxanthone. Further, sensitizing dyes include thiopyrylium salt dyes, merocyanine dyes, quinoline dyes, styrylquinoline dyes, ketocoumarin dyes, thioxanthene dyes, xanthene dyes, oxonol dyes, cyanine dyes, rhodamine dyes. And pyrylium salt pigments.

  As specific anthracene compounds, dibutoxyanthracene, dipropoxyanthraquinone (Anthracure UVS-1331, 1221 manufactured by Kawasaki Kasei Co., Ltd.) and the like are effective.

  When adding a sensitizer, it is preferable that the content is 0.01-20 mass parts with respect to the active energy ray-curable resin composition whole quantity, and it is 0.01-10 mass parts. More preferred is 0.1 to 3 parts by mass.

  In the polarizing plate according to the present invention, a transparent protective film is provided on at least one surface of a polarizer via an adhesive layer, and the adhesive layer is a cured product of the above-described active energy ray-curable resin composition. It is formed by a layer.

  The adhesive layer formed by the active energy ray-curable resin composition has higher durability than the aqueous adhesive layer. In the present invention, it is preferable to use an adhesive layer having a Tg of 60 ° C. or higher and to control the thickness of the adhesive layer to be 0.01 to 7 μm. As described above, in the polarizing plate of the present invention, the active energy ray-curable resin composition having an adhesive layer having a high Tg of 60 ° C. or higher is used, and the thickness of the adhesive layer is controlled within the above range. In addition, the durability under harsh environments under high humidity and high temperature can be satisfied. In consideration of the durability of the polarizing plate, in the present invention, in particular, when Tg (° C.) of the adhesive layer is defined as A and the thickness (μm) of the adhesive layer is defined as B, Formula (1): A− It is preferable that 12 × B> 58 is satisfied.

  As described above, the active energy ray-curable resin composition is preferably selected such that the Tg of the adhesive layer formed thereby is 60 ° C. or higher, more preferably 70 ° C. or higher. Further, it is preferably 75 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 120 ° C. or higher. On the other hand, if the Tg of the adhesive layer becomes too high, the flexibility of the polarizing plate is lowered. Therefore, the Tg of the adhesive layer is preferably 300 ° C. or lower, more preferably 240 ° C. or lower, and further preferably 180 ° C. or lower.

  Moreover, as above-mentioned, the thickness of an adhesive bond layer becomes like this. Preferably it is 0.01-7 micrometers, More preferably, it is 0.01-5 micrometers, More preferably, it is 0.01-2 micrometers, Most preferably, it is 0.01-1 micrometer. When the thickness of the adhesive layer is smaller than 0.01 μm, the cohesive force of the adhesive force itself cannot be obtained, and the adhesive strength may not be obtained. On the other hand, if the thickness of the adhesive layer exceeds 7 μm, the polarizing plate cannot satisfy the durability.

  In the polarizing plate according to the present invention, the active energy ray-curable resin composition is applied to the surface of the polarizer that forms the adhesive layer and / or the surface of the transparent protective film that forms the adhesive layer. A step of bonding the transparent protective film, and then a step of curing the active energy ray-curable resin composition by active energy ray irradiation to form an adhesive layer.

  The polarizer and the transparent protective film may be subjected to a surface modification treatment before applying the active energy ray-curable resin composition. Specific examples of the treatment include corona treatment, plasma treatment, and saponification treatment.

  The coating method of the active energy ray-curable resin composition is appropriately selected depending on the viscosity of the composition and the target thickness. Examples of coating methods include reverse coaters, gravure coaters (direct, reverse and offset), bar reverse coaters, roll coaters, die coaters, bar coaters, rod coaters and the like. In addition, for coating, a method such as a dapping method can be appropriately used.

  A polarizer and a transparent protective film are bonded together through the adhesive applied as described above. Bonding of the polarizer and the transparent protective film can be performed with a roll laminator or the like.

  After bonding a polarizer and a transparent protective film, an active energy ray (an electron beam, ultraviolet rays, etc.) is irradiated, an active energy ray hardening-type resin composition is hardened, and an adhesive bond layer is formed. The irradiation direction of active energy rays (electron beam, ultraviolet ray, etc.) can be irradiated from any appropriate direction. Preferably, it irradiates from the transparent protective film side. When irradiated from the polarizer side, the polarizer may be deteriorated by active energy rays (electron beams, ultraviolet rays, etc.).

  When the polarizing plate according to the present invention is produced in a continuous line, the line speed depends on the curing time of the adhesive, but is preferably 1 to 500 m / min, more preferably 5 to 300 m / min, and still more preferably 10 to 100 m / min. min. When the line speed is too low, productivity is poor, or damage to the transparent protective film is too great, and a polarizing plate that can withstand a durability test or the like cannot be produced. When the line speed is too high, the adhesive is not sufficiently cured, and the target adhesiveness may not be obtained.

  In the polarizing plate of the present invention, the polarizer and the transparent protective film are bonded together via an adhesive layer formed by a cured product layer of the active energy ray-curable resin composition. An easy-adhesion layer can be provided between the adhesive layers. The easy adhesion layer can be formed of, for example, various resins having a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a silicone-based, a polyamide skeleton, a polyimide skeleton, a polyvinyl alcohol skeleton, and the like. These polymer resins can be used alone or in combination of two or more. Moreover, you may add another additive for formation of an easily bonding layer. Specifically, a stabilizer such as a tackifier, an ultraviolet absorber, an antioxidant, and a heat resistance stabilizer may be used.

  The easy adhesion layer is usually provided in advance on a transparent protective film, and the easy adhesion layer side of the transparent protective film and the polarizer are bonded together with an adhesive layer. The easy-adhesion layer is formed by coating and drying the material for forming the easy-adhesion layer on the transparent protective film by a known technique. The material for forming the easy-adhesion layer is usually adjusted as a solution diluted to an appropriate concentration in consideration of the thickness after drying and the smoothness of coating. The thickness of the easy adhesion layer after drying is preferably 0.01 to 5 μm, more preferably 0.02 to 2 μm, and still more preferably 0.05 to 1 μm. Note that a plurality of easy-adhesion layers can be provided, but also in this case, the total thickness of the easy-adhesion layers is preferably in the above range.

  In the polarizing plate of the present invention, a transparent protective film is bonded to at least one surface of a polarizer via an adhesive layer formed of a cured product layer of the active energy ray-curable resin composition.

  The polarizer is not particularly limited, and various types can be used. Examples of the polarizer include hydrophilic polymer films such as polyvinyl alcohol film, partially formalized polyvinyl alcohol film, and ethylene / vinyl acetate copolymer partially saponified film, and two colors such as iodine and dichroic dye. And polyene-based oriented films such as those obtained by adsorbing a functional material and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic material such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 1 to 80 μm.

  A polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol in an aqueous solution of iodine and stretching it 3 to 7 times the original length. If necessary, it can be immersed in an aqueous solution of boric acid or potassium iodide. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with dirt and anti-blocking agents by washing the polyvinyl alcohol film with water, it also has the effect of preventing unevenness such as uneven coloring by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched in an aqueous solution of boric acid or potassium iodide or in a water bath.

  As a material for forming the transparent protective film provided on one side or both sides of the polarizer, a material excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is preferable. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene such as polystyrene and acrylonitrile / styrene copolymer (AS resin) And polymers based on polycarbonate and polycarbonate. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or the above Examples of the polymer that forms the transparent protective film include polymer blends. One or more kinds of arbitrary appropriate additives may be contained in the transparent protective film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, an anti-coloring agent, a flame retardant, a nucleating agent, an antistatic agent, a pigment, and a coloring agent. The content of the thermoplastic resin in the transparent protective film is preferably 50 to 100% by mass, more preferably 50 to 99% by mass, further preferably 60 to 98% by mass, and particularly preferably 70 to 97% by mass. . When content of the said thermoplastic resin in a transparent protective film is 50 mass% or less, there exists a possibility that the high transparency etc. which a thermoplastic resin originally has cannot fully be expressed.

  Moreover, as a transparent protective film, the polymer film as described in Unexamined-Japanese-Patent No. 2001-343529 (WO01 / 37007), for example, (A) thermoplastic resin which has a substituted and / or unsubstituted imide group in a side chain, ( B) Resin compositions containing a thermoplastic resin having substituted and / or unsubstituted phenyl and nitrile groups in the side chain. Specific examples include a film of a resin composition containing an alternating copolymer composed of isobutylene and N-methylmaleimide and an acrylonitrile / styrene copolymer. As the film, a film made of a mixed extruded product of the resin composition or the like can be used. Since these films have a small phase difference and a small photoelastic coefficient, problems such as unevenness due to the distortion of the polarizing plate can be eliminated, and since the moisture permeability is small, the humidification durability is excellent.

  Although the thickness of a transparent protective film can be determined suitably, generally it is about 1-500 micrometers from points, such as workability | operativity, such as intensity | strength and handleability, and thin-layer property. 1-300 micrometers is especially preferable, and 5-200 micrometers is more preferable.

  In addition, when providing a transparent protective film on both surfaces of a polarizer, the transparent protective film which consists of the same polymer material may be used by the front and back, and the transparent protective film which consists of a different polymer material etc. may be used.

  A functional layer such as a hard coat layer, an antireflection layer, an antisticking layer, a diffusion layer or an antiglare layer can be provided on the surface of the transparent protective film to which the polarizer is not adhered. The functional layers such as the hard coat layer, antireflection layer, antisticking layer, diffusion layer and antiglare layer can be provided on the transparent protective film itself, and separately provided separately from the transparent protective film. You can also.

  The polarizing plate of the present invention can be used as an optical film laminated with another optical layer in practical use. The optical layer is not particularly limited. For example, for forming a liquid crystal display device such as a reflection plate, a semi-transmission plate, a retardation plate (including wavelength plates such as 1/2 and 1/4), and a viewing angle compensation film. One or more optical layers that may be used can be used. In particular, a reflective polarizing plate or a semi-transmissive polarizing plate in which a polarizing plate or a semi-transmissive reflecting plate is further laminated on the polarizing plate of the present invention, an elliptical polarizing plate or a circularly polarizing plate in which a retardation plate is further laminated on the polarizing plate. A wide viewing angle polarizing plate obtained by further laminating a viewing angle compensation film on a plate or a polarizing plate, or a polarizing plate obtained by further laminating a brightness enhancement film on the polarizing plate is preferable.

  The optical film in which the optical layer is laminated on the polarizing plate can be formed by a method of laminating separately in the manufacturing process of a liquid crystal display device or the like. It is excellent in stability and assembly work, and has the advantage of improving the manufacturing process of a liquid crystal display device and the like. Appropriate bonding means such as an adhesive layer can be used for lamination. When adhering the above polarizing plate and other optical films, their optical axes can be set at an appropriate arrangement angle in accordance with the target retardation characteristics.

  An adhesive layer for adhering to other members such as a liquid crystal cell can be provided on the polarizing plate or the optical film in which at least one polarizing plate is laminated. The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited. For example, an acrylic polymer, silicone-based polymer, polyester, polyurethane, polyamide, polyether, fluorine-based or rubber-based polymer is appropriately selected. Can be used. In particular, those having excellent optical transparency such as an acrylic pressure-sensitive adhesive, exhibiting appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and being excellent in weather resistance, heat resistance and the like can be preferably used.

  The pressure-sensitive adhesive layer can be provided on one side or both sides of a polarizing plate or an optical film as a superimposed layer of different compositions or types. Moreover, when providing in both surfaces, it can also be set as adhesive layers with a different composition, a kind, thickness, etc. in the front and back of a polarizing plate or an optical film. The thickness of the pressure-sensitive adhesive layer can be appropriately determined according to the purpose of use and adhesive force, and is generally 1 to 500 μm, preferably 1 to 200 μm, and particularly preferably 1 to 100 μm.

  The exposed surface of the adhesive layer is temporarily covered with a separator for the purpose of preventing contamination until it is put into practical use. Thereby, it can prevent contacting an adhesion layer in the usual handling state. As the separator, except for the above thickness conditions, for example, a suitable thin leaf body such as a plastic film, rubber sheet, paper, cloth, non-woven fabric, net, foamed sheet, metal foil, laminate thereof, and the like, silicone type or Appropriate ones according to the prior art, such as those coated with an appropriate release agent such as long-chain alkyl, fluorine-based or molybdenum sulfide, can be used.

  The polarizing plate or the optical film of the present invention can be preferably used for forming various devices such as a liquid crystal display device. The liquid crystal display device can be formed according to the conventional method. That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell, a polarizing plate or an optical film, and an illumination system as necessary, and incorporating a drive circuit. There is no limitation in particular except the point which uses the polarizing plate or optical film by invention, and it can apply according to the former. As the liquid crystal cell, any type such as a TN type, an STN type, or a π type can be used.

  An appropriate liquid crystal display device such as a liquid crystal display device in which a polarizing plate or an optical film is disposed on one side or both sides of a liquid crystal cell, or a backlight or a reflector used in an illumination system can be formed. In that case, the polarizing plate or optical film by this invention can be installed in the one side or both sides of a liquid crystal cell. When providing a polarizing plate or an optical film on both sides, they may be the same or different. Further, when forming a liquid crystal display device, for example, a single layer or a suitable part such as a diffusing plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusing plate, a backlight, etc. Two or more layers can be arranged.

  Examples of the present invention will be described below, but the embodiments of the present invention are not limited thereto.

<Tg: Glass transition temperature>
It measured with the temperature increase rate of 10 degree-C / min using the glass transition point temperature differential scanning calorimeter (DSC). As a sample, 5 mg of a sample was placed in an aluminum press-lid container and crimped.

<Polarizer>
A polyvinyl alcohol film having an average polymerization degree of 2400 and a saponification degree of 99.9 mol% and a thickness of 75 μm was immersed in warm water at 30 ° C. for 60 seconds to swell. Next, the film was dyed while being immersed in an aqueous solution of 0.3% concentration of iodine / potassium iodide (weight ratio = 0.5 / 8) and stretched to 3.5 times. Then, it extended | stretched so that the total draw ratio might be 6 times in 65 degreeC borate ester aqueous solution. After extending | stretching, it dried for 3 minutes in 40 degreeC oven, and obtained the polarizer.

<Transparent protective film>
As a first protective film, a triacetyl cellulose film (TAC) having a thickness of 80 μm was immersed in a 10% by mass aqueous solution of sodium hydroxide heated to 60 ° C. for 30 seconds, and then dried by a hot air dryer. As the second protective film, a 60 μm thick ZEONOR film (manufactured by Nippon Zeon Co., Ltd.) subjected to corona treatment was used. The contact angle at 23 ° C. was 32 °.

<Active energy rays>
The following (A), (B) and (C) were used as active energy rays. In addition, the illumination intensity of (A) and (B) was measured using the Sola-Check system made from Solatell.

(A) Ultraviolet light (gallium filled metal halide lamp) Irradiation device: Fusion UV Systems, Inc. Light HAMMER10 bulb: V bulb Peak illuminance: 1600 mW / cm ² , integrated irradiation amount 1000 / mJ / cm ² (wavelength 380 to 440 nm)
(B) Ultraviolet light (LED light source (LED light source having a peak illuminance at 385 nm)) Irradiation device: Panasonic Electric Works Aicure UD80 Peak illuminance: 3900 mW / cm ² , integrated irradiation amount 300 / mJ / cm ² (wavelength 380 to 440 nm)
(C) Electron beam irradiation device: Electron beam irradiation device manufactured by Eye Electron Beam Co., Ltd. Acceleration voltage: 250 kV Irradiation dose 20 kGy

(Adjustment of active energy ray-curable resin composition)
Examples 1-3, Comparative Examples 1-2
According to the recipe shown in Table 1, each component was mixed and stirred at 50 ° C. for 1 hour, and the active energy ray-curable resin compositions (a) to (e) (Examples 1 to 3, Comparative Examples 1 to 1). 2) was obtained. Each component used is as follows.

HEAA (hydroxyethyl acrylamide, N-substituted amide monomer described in the general formula (1)), 4HBA (4-hydroxybutyl acrylate) manufactured by Kojin Co., Ltd., Wasmer 2MA (N-methoxymethyl acrylamide) manufactured by Osaka Organic Chemical Industry Co., Ltd. N-substituted amide monomer described in general formula (1)), light acrylate DCP-A (tricyclodecane dimethanol diacrylate, hydrophobic polyfunctional (meth) acrylate monomer) manufactured by Kasano Kosan Co., Ltd., Kyoeisha Chemical Co., Ltd. Light acrylate P-1A (2-acryloyloxyethyl acid phosphate, phosphoric acid group-containing (meth) acrylate monomer described in the general formula (2)), β-CEA (β-carboxyethyl acrylate, manufactured by Kyoeisha Chemical Co., Ltd. Acid group-containing (meth) acrylate monomer), Daise - Cytec acrylate, Toagosei Co., Ltd. IRGACURE 819 (bis (2,4,6-trimethylbenzoyl) - phenyl phosphinothricin key side (photo-radical generator), manufactured by Ciba Japan K.K.

Production Examples 1 to 5 of Polarizing Plate
On the said transparent protective film, Examples 1-3, the active energy ray hardening-type resin composition (a) (henceforth only "composition (a)")-(e) which concerns on Comparative Examples 1-2, Using an MCD coater (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, number of gravure roll wires: 1000 / inch, rotation speed 140% / line speed), coating was performed to a thickness of 0.5 μm. It bonded together on both surfaces of the said polarizer with the roll machine. Thereafter, from the bonded transparent protective film side (both sides), it is heated to 50 ° C. using an IR heater (but not heated in Example 3), and the active energy rays (A) to (C) are applied to both sides. The composition (a) to (e) is cured by irradiation and then dried with hot air at 70 ° C. for 3 minutes (however, no hot air drying in Example 2), and polarized light having a transparent protective film on both sides of the polarizer. I got a plate. The line speed of bonding was 25 m / min.

[Evaluation]
The following evaluation was performed about the polarizing plate obtained by the Example and the comparative example. The results are shown in Table 2.

<Adhesion test of transparent protective film>
The polarizing plate is cut into a size of 200 mm in parallel to the stretching direction of the polarizer and 20 mm in the orthogonal direction, and a transparent knife is cut between the transparent protective film (triacetylcellulose film, ZEONOR film) and the polarizer with a polarizing knife. The plate was bonded to a glass plate. With Tensilon, the protective film and the polarizer were peeled off at 90 ° direction at a peeling speed of 500 mm / min, and the peel strength was measured. In addition, the infrared absorption spectrum of the peeled surface after peeling is measured by the ATR method. If both surfaces of the peeled surface are derived from the transparent protective film, ○ (cohesive failure of the transparent protective film), both surfaces of the peeled surface are bonded. △ (cohesive failure of the adhesive layer) if the spectrum is derived from the adhesive layer, × (protective film) if one side of the release surface is the spectrum of the adhesive layer, and the other side is a spectrum derived from the polarizer or transparent protective film And interfacial peeling between the adhesive layer and the adhesive layer.

<Hot water immersion test>
The polarizing plate was cut out to a size of 50 mm square, immersed in warm water at 60 ° C. for 6 hours, and the area residual ratio of the polarizer having a transmittance of 50% or less was measured. Each polarizing plate was evaluated according to the following criteria.
○: 90% or more △; 50-90%
×: Less than 50%

<Heat shock crack test>
A polarizing plate cut out to a size of 15 inches is attached to a glass plate, a heat cycle test from −40 ° C. to 80 ° C. is performed, and whether or not cracks are generated in the stretching direction of the polarizer after 100 cycles is determined. Visual evaluation was made according to the following criteria.
○: No occurrence of cracks in the polarizer Δ: Cracks are generated from one side of the polarizing plate, but have not reached the opposite sides ×: Cracks that have reached both opposite sides of the polarizing plate have occurred

Claims (10)

In a polarizing plate in which a transparent protective film is bonded to at least one surface of a polarizer via an adhesive layer, an active energy ray-curable resin composition for forming the adhesive layer,
As the curable component, the following general formula (1):
^{_{CH 2 = C (R 1)}} -CONH 2-m - (X-O-R 2) m (1)
(R ¹ represents a hydrogen atom or a methyl group, X represents a —CH ₂ — group or a —CH ₂ CH ₂ — group, R ² represents a — (CH ₂ ) _n —H group (where n is 0, 1 Or 2), m represents 1 or 2), and an acid in which a (meth) acryloyl group and an acid group are bonded via an organic group having 1 to 10 carbon atoms Containing a group-containing (meth) acrylate monomer ,
The organic group is a (poly) alkylene oxide group;
The active energy ray-curable resin composition, wherein the acid group is a phosphate group . The acid group-containing (meth) acrylate monomer is represented by the following general formula (2):
^{_{(CH 2 = C (R 3}} ) -COO-Y) r -PO- (OH) 3-r (2)
(R ³ represents a hydrogen atom or a methyl group, Y represents — (CH ₂ CHR ⁴ —O) _s — (where R ⁴ represents a hydrogen atom, a methyl group or a chloromethyl group, and s represents 1 to 6). The active energy ray curing according to claim 1, wherein the phosphoric acid group-containing (meth) acrylate monomer is a (poly) alkylene oxide group represented by: Mold resin composition. The active energy ray-curable type according to claim 1 or 2 , wherein a ratio of the acid group-containing (meth) acrylate monomer to a total amount of monomers constituting the curable component is 0.01% by mass or more and less than 10% by mass. Resin composition. Furthermore, the active energy ray hardening-type resin composition in any one of Claims 1-3 containing the monomer which has a 2 or more carbon-carbon double bond. The adhesive bond layer formed of the hardened | cured material layer of the active energy ray hardening-type resin composition in any one of Claims 1-4 . The adhesive layer according to claim 5 , wherein the glass transition temperature (Tg) is 60 ° C. or higher. A polarizing plate in which a transparent protective film is provided via an adhesive layer on at least one surface of a polarizer,
The said adhesive bond layer is formed by the hardened | cured material layer of the active energy ray hardening-type resin composition in any one of Claims 1-4 , The polarizing plate characterized by the above-mentioned. The polarizing plate according to claim 7 , wherein the adhesive layer has a glass transition temperature (Tg) of 60 ° C. or higher. 9. An optical film, wherein at least one polarizing plate according to claim 7 or 8 is laminated. The image display apparatus characterized by polarizing plate according to claim 7 or 8, and / or optical film according to claim 9 is used.