JP6376872B2 - Method for producing laminated optical film - Google Patents

Description

  The present invention relates to a method for producing a laminated optical film in which at least a first optical film and a second optical film are laminated via an adhesive layer formed by curing an active energy ray-curable adhesive composition. The laminated optical film can form an image display device such as a liquid crystal display device (LCD), an organic EL display device, a CRT, or a PDP.

  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 TV, higher brightness, higher contrast, and wider viewing angle are required, and polarizing films 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 film in which a transparent protective film is bonded to both surfaces of a polarizer by a so-called aqueous adhesive in which a polyvinyl alcohol-based material is dissolved in water is used (Patent Document 1 and Patent Document 2 below). ). As the transparent protective film, triacetyl cellulose having a high moisture permeability is used. When the water-based adhesive is used (so-called wet lamination), a drying process is required after the polarizer and the transparent protective film are bonded together.

  On the other hand, an active energy ray-curable adhesive has been proposed instead of the water-based adhesive. When manufacturing a polarizing film using an active energy ray hardening-type adhesive, since a drying process is not required, productivity of a polarizing film can be improved. For example, the present inventors have proposed radical polymerization-type active energy ray-curable adhesives using N-substituted amide monomers as curable components (Patent Documents 3 and 4 below).

JP 2006-220732 A JP 2001-296427 A JP2012-052000A JP 2012-068593 A

  The adhesive layer formed using the active energy ray-curable adhesive described in Patent Documents 3 and 4 is, for example, a water resistance test for evaluating the presence or absence of color loss or peeling after immersion in warm water at 60 ° C. for 6 hours. It is clear enough. However, in recent years, the adhesive for a laminated optical film can be cleared of a more severe water resistance test that evaluates the presence or absence of peeling when, for example, peeling off an end nail after being immersed (saturated) in water. Further improvement of water resistance is being demanded. Therefore, the adhesives for laminated optical films reported up to now including the active energy ray-curable adhesives described in Patent Documents 3 and 4 have room for further improvement in terms of water resistance. Met.

  By the way, in recent years, an organic polymer material is often required to have a trade-off characteristic, and it is actually difficult to satisfy the required characteristic with a single organic polymer material. In order to satisfy the contradictory required characteristics, techniques for adding and compounding different kinds of materials having different properties to organic polymer materials have been proposed in many fields. In the bonding technique, for example, when two different types of adherends are bonded, it is conceivable to form the adhesive layer so as to have a two-layer structure in order to improve the adhesion to each adherend. However, when the adhesive layer is formed in a two-layer structure, stress concentrates on the interface, and the adhesive force of the adhesive layer may be reduced. Particularly, in recent years, it is difficult to establish a technique for forming an adhesive layer with a two-layer structure in an adhesive for laminated optical films that is required to be thin, and there is no such report as far as the present inventors can know. .

  As described above, in the field of adhesives for laminated optical films, particularly where thinning is required, it is difficult to develop a technology that increases water resistance while increasing adhesion when two different optical films are bonded. There was a real situation.

  The present invention has been developed to solve the above-described problems, and exhibits a high adhesive force when laminating two different types of optical films, and manufactures a laminated optical film having an adhesive layer excellent in water resistance. It aims to provide a method.

  When the optical films to be laminated are different from each other, for example, to show different properties from the viewpoint of hydrophilicity, forming an adhesive layer for laminating these optical films in a two-layer structure is Although it is advantageous from the viewpoint of improving the adhesive strength, as described above, there is a possibility that the adhesive strength may decrease due to interfacial peeling in the adhesive layer.

On the other hand, an active energy ray containing at least two or more different active energy ray curable adhesive compositions, including the first active energy ray curable adhesive composition and the second active energy ray curable adhesive composition. According to the production method in which the first optical film and the second optical film are bonded by irradiating active energy rays after bonding two optical films through the curable adhesive composition. The present inventors have found that even when active energy ray-curable adhesive compositions having different values are used, interfacial peeling does not easily occur in the adhesive layer. The present invention has been completed based on this discovery, and has the following configuration.

That is, the present invention is a method for producing a laminated optical film in which at least a first optical film and a second optical film are laminated via an adhesive layer formed by curing an active energy ray-curable adhesive composition. The active energy ray-curable adhesive composition includes at least two different active energy rays including a first active energy ray-curable adhesive composition and a second active energy ray-curable adhesive composition. It contains a curable adhesive composition, the first active energy ray-curable adhesive composition is applied to the bonding surface of the first optical film, and the bonding surface of the second optical film is further applied. A coating step of coating the second active energy ray-curable adhesive composition, a bonding step of bonding the first optical film and the second optical film, Through the adhesive layer formed by irradiating active energy rays from the first optical film surface side or the second optical film surface side and curing the active energy ray-curable adhesive composition, The manufacturing method of the lamination | stacking optical film characterized by including the adhesion process to adhere | attach a 1st optical film and a said 2nd optical film.

  According to the manufacturing method of the laminated optical film, the first active energy ray-curable adhesive composition applied to the bonding surface of the first optical film and the bonding surface of the second optical film were applied. The second active energy ray-curable adhesive composition is bonded in a fluid state. As a result, even if the first active energy ray-curable adhesive composition and the second active energy ray-curable adhesive composition are different from each other, a certain degree of compatibilization proceeds between the two layers. The agent layer does not form a two-layer structure, but forms a component gradient structure. Therefore, interface peeling between the first active energy ray-curable adhesive composition and the second active energy ray-curable adhesive composition hardly occurs. Therefore, the first active energy ray-curable adhesive composition having high affinity with the first optical film is appropriately selected, and the second active energy ray-curable adhesive composition having high affinity with the second optical film is appropriately selected. By selecting, the laminated optical film which has favorable adhesiveness between a 1st optical film and a 2nd optical film can be manufactured, preventing delamination in an adhesive bond layer.

  In the method for producing a laminated optical film according to the present invention, at least the first optical film and the second optical film are laminated via an adhesive layer formed by curing the active energy ray-curable adhesive composition. A method for producing a laminated optical film, wherein the active energy ray-curable adhesive composition includes a first active energy ray-curable adhesive composition and a second active energy ray-curable adhesive composition, Containing at least two different active energy ray-curable adhesive compositions, applying the first active energy ray-curable adhesive composition to the bonding surface of the first optical film, A coating step in which the second active energy ray-curable adhesive composition is further overcoated on the coating surface coated with the first active energy ray-curable adhesive composition; A bonding step of bonding the second optical film from the coating surface side of the second active energy ray-curable adhesive composition coated on the optical film, and the first optical film surface side or the second optical film; The first optical film and the second optical film are bonded via the adhesive layer formed by irradiating active energy rays from the surface side and curing the active energy ray-curable adhesive composition. The manufacturing method of the laminated optical film characterized by including the adhesion process to make.

  According to the manufacturing method of the said laminated optical film, with respect to the 1st active energy ray hardening-type adhesive composition coated on the bonding surface of the 1st optical film, a 2nd active energy ray hardening-type adhesive composition is The top coat is applied. And it applied to the coating surface which applied the 1st active energy ray hardening-type adhesive composition coated on the bonding surface of a 1st optical film, and the 1st active energy ray hardening-type adhesive composition. The second active energy ray-curable adhesive composition is in contact with the fluidity state. As a result, even if the first active energy ray curable adhesive composition and the second active energy ray curable adhesive composition have different compositions, a certain degree of compatibilization proceeds at these interfaces, and the component gradient A structure is formed. Therefore, interface peeling between the first active energy ray-curable adhesive composition and the second active energy ray-curable adhesive composition hardly occurs. Therefore, the first active energy ray-curable adhesive composition having high affinity with the first optical film is appropriately selected, and the second active energy ray-curable adhesive composition having high affinity with the second optical film is appropriately selected. By selecting, it is possible to produce a laminated optical film in which the first optical film and the second optical film have good adhesiveness while preventing delamination in the adhesive layer.

  In the method for producing a laminated optical film, the liquid viscosity of the first active energy ray-curable adhesive composition is preferably higher than the liquid viscosity of the second active energy ray-curable adhesive composition. When overcoating the second active energy ray-curable adhesive composition with respect to the first active energy ray-curable adhesive composition coated on the bonding surface of the first optical film, the first active energy ray-curable type is applied. When the liquid viscosity of the adhesive composition is higher than the liquid viscosity of the second active energy ray curable adhesive composition, the second active energy ray curable adhesive composition is changed to the first active energy ray curable adhesive composition. It can be reliably applied on the object.

  In the method for producing a laminated optical film, it is preferable that a contact angle of the active energy ray-curable adhesive composition with respect to the first optical film and the second optical film is 5 to 50 degrees. According to such a configuration, the wettability of the active energy ray-curable adhesive composition is excellent with respect to the first optical film and the second optical film, so that the interlayer adhesiveness of the finally obtained laminated optical film is sufficiently ensured. it can.

  In the method for producing a laminated optical film, the first optical film and the second optical film are selected from the group consisting of a polyvinyl alcohol polarizer, an acrylic resin film, a cycloolefin resin film, a polyester resin film, and a polyolefin resin film. Preferably, the first optical film and the second optical film are selected from the group consisting of the acrylic resin film, the cycloolefin resin film, the polyester resin film, and the polyolefin resin film. It is preferable that it is at least one optical film selected. When the optical film to be laminated is as described above, it is possible to produce a laminated optical film having an adhesive layer exhibiting high adhesive force when laminated and having excellent water resistance.

  In the method for producing a laminated optical film, the acrylic resin film, the cycloolefin resin film, the polyester resin film, and the polyolefin resin film have an acrylic resin, a polyurethane resin, a polyvinyl alcohol resin, a melamine resin, In the case where an easy-adhesion layer containing at least one resin selected from the group consisting of oxazoline group-containing resins is formed, the adhesive property of the laminated optical film is further increased, which is preferable.

In the method for producing a laminated optical film, at least the first optical film and the second optical film are selected from the group consisting of the acrylic resin film, the cycloolefin resin film, the polyester resin film, and the polyolefin resin film. In the case of one type of optical film, the active energy ray-curable adhesive composition contains 25 to 98 radical polymerizable compounds having an SP value of 18 to 21 (MJ / m ³ ) ^1/2. When it is contained by weight, the following effects are obtained. Specifically, when the specific optical film is used and the active energy ray-curable adhesive composition contains a predetermined amount of a radical polymerizable compound exhibiting a predetermined SP value, A compatible layer is formed between the optical film and the optical film. As a result, the adhesive property of the laminated optical film is further increased, which is preferable.

  In the method for producing a laminated optical film, one of the first optical film and the second optical film is the polyvinyl alcohol polarizer, and the active energy is applied to a bonding surface of the polyvinyl alcohol polarizer. It is preferable that the wire curable adhesive composition contains a hydroxyl group-containing radical polymerizable compound. This configuration is preferable because the adhesive force between the polyvinyl alcohol polarizer and the adhesive layer is further increased.

Schematic which shows the evaluation method of the component inclination structure in the adhesive bond layer using TOF-SIMS

  The laminated optical film according to the present invention is obtained by laminating at least a first optical film and a second optical film via an adhesive layer formed by curing an active energy ray-curable adhesive composition. The adhesive layer is formed of a cured product layer obtained by irradiating an active energy ray-curable adhesive composition with active energy rays.

  Active energy ray curable adhesive compositions can be broadly classified into electron beam curable, ultraviolet curable, visible light curable, and the like. Furthermore, ultraviolet curable and visible light curable adhesives can be classified into radical polymerization curable adhesives and cationic polymerization adhesives. In the present invention, an active energy ray having a wavelength range of 10 nm to less than 380 nm is expressed as ultraviolet light, and an active energy ray having a wavelength range of 380 nm to 800 nm is expressed as visible light.

  Examples of the compound constituting the radical polymerization curable adhesive include a radical polymerizable compound. Examples of the radical polymerizable compound include compounds having a radical polymerizable functional group of a carbon-carbon double bond such as a (meth) acryloyl group and a vinyl group. As these curable components, either a monofunctional radical polymerizable compound or a bifunctional or higher polyfunctional radical polymerizable compound can be used. Moreover, these radically polymerizable compounds can be used individually by 1 type or in combination of 2 or more types. As these radically polymerizable compounds, for example, compounds having a (meth) acryloyl group are suitable. The active energy ray-curable adhesive composition used in the present invention preferably contains a compound having a (meth) acryloyl group as a main component. Specifically, the total amount of the active energy ray-curable adhesive composition is When the content is 100% by weight, the compound having a (meth) acryloyl group is preferably contained in an amount of 50% by weight or more, and more preferably 80% by weight or more. In the present invention, (meth) acryloyl means an acryloyl group and / or methacryloyl group, and “(meth)” has the same meaning hereinafter.

<Monofunctional radical polymerizable compound>
Examples of the monofunctional radical polymerizable compound include (meth) acrylamide derivatives having a (meth) acrylamide group. A (meth) acrylamide derivative is preferable in terms of securing adhesiveness with a polarizer and various transparent protective films, and having a high polymerization rate and excellent productivity. Specific examples of (meth) acrylamide derivatives include, for example, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N -N-alkyl group-containing (meth) acrylamide derivatives such as butyl (meth) acrylamide, N-hexyl (meth) acrylamide; N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N-methylol-N- N-hydroxyalkyl group-containing (meth) acrylamide derivatives such as propane (meth) acrylamide; N-aminoalkyl group-containing (meth) acrylamide derivatives such as aminomethyl (meth) acrylamide and aminoethyl (meth) acrylamide; N-methoxymethyl N-alkoxy group-containing (meth) acrylamide derivatives such as acrylamide and N-ethoxymethylacrylamide; N-mercaptoalkyl group-containing (meth) acrylamide derivatives such as mercaptomethyl (meth) acrylamide and mercaptoethyl (meth) acrylamide; It is done. Examples of the heterocyclic-containing (meth) acrylamide derivative in which the nitrogen atom of the (meth) acrylamide group forms a heterocyclic ring include, for example, N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, and N-acryloylpyrrolidine. Etc.

  Among the (meth) acrylamide derivatives, N-hydroxyalkyl group-containing (meth) acrylamide derivatives are preferable from the viewpoint of adhesion to polarizers and various transparent protective films, and monofunctional radical polymerizable compounds are also preferred. Examples include various (meth) acrylic acid derivatives having a (meth) acryloyloxy group. Specifically, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, 2-methyl-2-nitropropyl (meth) acrylate, n-butyl ( (Meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, t-pentyl (meth) acrylate, 3-pentyl (meth) acrylate, 2,2-dimethylbutyl (meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 4-methyl-2-propylpentyl ( (Meth) acrylate, n-o Tadeshiru (meth) (meth) acrylic acid (1-20 carbon atoms) such as acrylates alkyl esters.

  Examples of the (meth) acrylic acid derivative include cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate and cyclopentyl (meth) acrylate; aralkyl (meth) acrylates such as benzyl (meth) acrylate; 2-isobornyl (Meth) acrylate, 2-norbornylmethyl (meth) acrylate, 5-norbornen-2-yl-methyl (meth) acrylate, 3-methyl-2-norbornylmethyl (meth) acrylate, dicyclopentenyl (meth) ) Polycyclic (meth) acrylates such as acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate; 2-methoxyethyl (meth) acrylate, 2-ethoxy Ethyl (meth) acrylate, 2 Alkoxy or phenoxy group-containing (meth) methoxymethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, alkylphenoxy polyethylene glycol (meth) acrylate ) Acrylate;

  Examples of the (meth) acrylic acid derivative include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4- Hydroxyalkyl (meth) acrylates such as hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate And [4- (hydroxymethyl) cyclohexyl] methyl acrylate, cyclohexanedimethanol mono (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate and other hydroxyl group-containing (Meth) acrylate; glycidyl (meth) acrylate, epoxy group-containing (meth) acrylate such as 4-hydroxybutyl (meth) acrylate glycidyl ether; 2,2,2-trifluoroethyl (meth) acrylate, 2,2,2- Trifluoroethylethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate, 3-chloro-2-hydroxypropyl Halogen-containing (meth) acrylates such as (meth) acrylates; alkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate; 3-oxetanylmethyl (meth) acrylates, 3 Oxetane group-containing (meth) acrylates such as methyl-oxetanylmethyl (meth) acrylate, 3-ethyl-oxetanylmethyl (meth) acrylate, 3-butyl-oxetanylmethyl (meth) acrylate, 3-hexyloxoxanylmethyl (meth) acrylate, etc. ; (Meth) acrylate having a heterocyclic ring such as tetrahydrofurfuryl (meth) acrylate and butyrolactone (meth) acrylate, neopentyl glycol (meth) acrylic acid hydroxypivalate, p-phenylphenol (meth) acrylate, etc. Is mentioned.

  Examples of the monofunctional radically polymerizable compound include carboxyl group-containing monomers such as (meth) acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid.

  Examples of the monofunctional radical polymerizable compound include lactam vinyl monomers such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, and methylvinylpyrrolidone; vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, Examples thereof include vinyl monomers having a nitrogen-containing heterocyclic ring such as vinyl pyrrole, vinyl imidazole, vinyl oxazole and vinyl morpholine.

  Moreover, as a monofunctional radically polymerizable compound, the radically polymerizable compound which has an active methylene group can be used. The radical polymerizable compound having an active methylene group is a compound having an active methylene group having an active double bond group such as a (meth) acryl group at the terminal or in the molecule. Examples of the active methylene group include an acetoacetyl group, an alkoxymalonyl group, and a cyanoacetyl group. The active methylene group is preferably an acetoacetyl group. Specific examples of the radical polymerizable compound having an active methylene group include 2-acetoacetoxyethyl (meth) acrylate, 2-acetoacetoxypropyl (meth) acrylate, 2-acetoacetoxy-1-methylethyl (meth) acrylate, and the like. Acetoacetoxyalkyl (meth) acrylate; 2-ethoxymalonyloxyethyl (meth) acrylate, 2-cyanoacetoxyethyl (meth) acrylate, N- (2-cyanoacetoxyethyl) acrylamide, N- (2-propionylacetoxybutyl) Examples include acrylamide, N- (4-acetoacetoxymethylbenzyl) acrylamide, and N- (2-acetoacetylaminoethyl) acrylamide. The radical polymerizable compound having an active methylene group is preferably acetoacetoxyalkyl (meth) acrylate.

<Polyfunctional radical polymerizable compound>
Examples of the bifunctional or higher polyfunctional radical polymerizable compound include tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9. -Nonanediol di (meth) acrylate, 1,10-decanediol diacrylate, 2-ethyl-2-butylpropanediol di (meth) acrylate, bisphenol A di (meth) acrylate, bisphenol A ethylene oxide adduct di (meth) ) Acrylate, bisphenol A propylene oxide adduct di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neopentyl glycol di (meth) acrylate, tricyclodecane dimethanol di (meth) Acryte, cyclic trimethylolpropane formal (meth) acrylate, dioxane glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta Esterified products of (meth) acrylic acid and polyhydric alcohols such as (meth) acrylate, dipentaerythritol hexa (meth) acrylate, EO-modified diglycerin tetra (meth) acrylate, 9,9-bis [4- (2- (Meth) acryloyloxyethoxy) phenyl] fluorene. Specific examples include Aronix M-220 (manufactured by Toagosei Co., Ltd.), light acrylate 1,9ND-A (manufactured by Kyoeisha Chemical Co., Ltd.), light acrylate DGE-4A (manufactured by Kyoeisha Chemical Co., Ltd.), and light acrylate DCP-A (kyoeisha chemical) SR-531 (manufactured by Sartomer), CD-536 (manufactured by Sartomer), and the like. Moreover, various epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates, various (meth) acrylate monomers, and the like are included as necessary.

In the present invention, the optical film to be bonded is at least one optical film selected from the group consisting of an acrylic resin film, a cycloolefin resin film, a polyester resin film, and a polyolefin resin film, and an active energy ray When the curable adhesive composition contains 25 to 98% by weight of a radically polymerizable compound having an SP value of 18 to 21 (MJ / m ³ ) ^1/2 when the total amount of the composition is 100% by weight. When containing 30 to 90% by weight, more preferably 40 to 80% by weight, a compatible layer is formed between the adhesive layer and the optical film. As a result, the adhesive property of the laminated optical film is further increased, which is preferable.

Here, the calculation method of the SP value (solubility parameter) in the present invention will be described below.

(Calculation method of solubility parameter (SP value))
In the present invention, the solubility parameter (SP value) of a radically polymerizable compound, a polarizer, various transparent protective films and the like is calculated by the FEDORS calculation method [“Polymer Engineering and Science (POLYMER ENG. & SCI.)”, No. 14, Vol. 2 (1974), pages 148-154]

Where ΔEI is the evaporation energy at 25 ° C. belonging to the atom or group, and ΔVI is the molar volume at 25 ° C.

  In the above formulas, ΔEI and ΔVI represent constant numerical values given to I atoms and groups in the main molecule. Table 1 below shows typical examples of numerical values of ΔE and ΔV given to atoms or groups.

Specific examples of the radical polymerizable compound having an SP value of 18 to 21 (MJ / m ³ ) ^1/2 include, for example, tripropylene glycol diacrylate (SP value 19.0 (MJ / m ³ ) ^1/2 ) 1,9-nonanediol diacrylate (SP value 19.2 (MJ / m ³ ) ^1/2 ), tricyclodecane dimethanol diacrylate (SP value 20.3 (MJ / m ³ ) ^1/2 ), Cyclic trimethylolpropane formal acrylate (SP value 19.1 (MJ / m ³ ) ^1/2 ), dioxane glycol diacrylate (SP value 19.4 (MJ / m ³ ) ^1/2 ), EO-modified diglycerin tetra Acrylate (SP value 20.9 (MJ / m ³ ) ^1/2 ) and the like. In addition, a commercial item can also be used suitably as a radically polymerizable compound whose SP value is 18-21 (MJ / m < ³ >) < ^1/2 >, for example, Aronix M-220 (made by Toagosei Co., Ltd., SP value 19. 0 (MJ / m ³ ) ^1/2 ), light acrylate 1,9ND-A (manufactured by Kyoeisha Chemical Co., Ltd., SP value 19.2 (MJ / m ³ ) ^1/2 ), light acrylate DGE-4A (Kyoeisha Chemical Co., Ltd.) Manufactured, SP value 20.9 (MJ / m ³ ) ^1/2 ), light acrylate DCP-A (manufactured by Kyoeisha Chemical Co., SP value 20.3 (MJ / m ³ ) ^1/2 ), SR-531 (SARTOMER) And SP-value 19.1 (MJ / m ³ ) ^1/2 ), CD-536 (manufactured by SARTOMER, SP value 19.4 (MJ / m ³ ) ^1/2 ), and the like.

  In the method for producing a laminated optical film according to the present invention, the active energy ray-curable adhesive composition to be used is a first active energy ray-curable adhesive composition and a second active energy ray-curable adhesive composition. It is characterized by containing at least two or more different active energy ray-curable adhesive compositions. “Active energy ray-curable adhesive composition is different” means that the radically polymerizable compound and the composition ratio are different, for example, from the viewpoint of hydrophilicity / hydrophobicity, the active energy ray-curable adhesive composition is It means having different characteristics. When the laminated optical film produced in the production method according to the present invention is, for example, a polarizing film in which a transparent protective film is laminated on at least one surface of the polarizer via an adhesive layer, the polarizer is hydrophilic. On the other hand, transparent protective films tend to be hydrophobic. Therefore, in this invention, when a 1st optical film is a polarizer and a 2nd optical film is a transparent protective film, in order to improve adhesiveness, the 1st active energy ray hardening type distribute | arranged to the 1st optical film side The adhesive composition is preferably hydrophilic, and the second active energy ray-curable adhesive composition is preferably hydrophobic.

  In the present invention, logPow is an index for evaluating the hydrophilicity and hydrophobicity of the radical polymerizable compound contained in the active energy ray-curable adhesive composition. The octanol / water partition coefficient (logPow) is an index representing the lipophilicity of a substance, and means the logarithmic value of the octanol / water partition coefficient. High logPow means that it is lipophilic, that is, low water absorption. The logPow value can be measured (flask immersion method described in JIS-Z-7260), but can also be calculated. In this specification, the logPow value calculated by Chem Draw Ultra manufactured by Cambridge Soft is used.

  In particular, in the present invention, when the first optical film is a polarizer and the second optical film is a transparent protective film, the first active energy ray-curable adhesive composition disposed on the first optical film side has a log Pow of It is preferable to contain the A component which is -1-1, and it is preferable that the 2nd active energy ray hardening-type adhesive composition contains the B component whose logPow is 2-7. In such a configuration, (i) the first active energy ray-curable adhesive composition is applied to the bonding surface of the first optical film, and the second active energy beam curing is further applied to the bonding surface of the second optical film. Or (ii) applying the first active energy ray-curable adhesive composition to the bonding surface of the first optical film, and applying the first active energy ray-curable adhesive. When the second active energy ray-curable adhesive composition is further overcoated on the coated surface on which the composition is applied, the adhesive layer interposed between the polarizer and the transparent protective film is on the polarizer side. It has a component gradient structure in which the concentration of the A component exhibiting high hydrophilicity is high. For this reason, a polarizer and a transparent protective film show the adhesiveness which was excellent, and a polarizing film provided with the adhesive bond layer excellent in water resistance can be manufactured.

For example, in the adhesive layer of the polarizing film, a method for confirming that the component A has a component gradient structure in which the concentration of the component A changes in the thickness direction is, for example, time of flight secondary ion mass spectrometry (Time of Flight Secondary Ion Mass). The method of using Spectrometry (TOF-SIMS) is mentioned. The principle of TOF-SIMS is that when a sample is irradiated with a primary ion beam (for example, 1E12 ions / cm ² or less) under an ultra-high vacuum, secondary ions are released only from the outermost surface of the sample (a depth of about several millimeters). A mass spectrum is obtained by introducing secondary ions into a time-of-flight (TOF type) mass spectrometer. By utilizing this principle, information on the chemical composition of the elemental composition and compound existing on the outermost surface of the sample can be obtained. Furthermore, in this invention, in order to confirm the component inclination structure in the thickness direction in the adhesive bond layer interposed between a transparent protective film and a polarizer, a cluster ion etching method can be used.

The “cluster ion etching method” will be described below. For example, when the surface of the adhesive layer is etched using a general etching method using a monoatomic ion beam (Ar ⁺ , Cs ^+, etc.) as etching ions, the molecular structure on the surface of the adhesive layer is destroyed, A damage layer is formed. In this case, even if an attempt is made to obtain the mass spectrum of the surface using TOF-SIMS, an accurate mass spectrum of the surface of the adhesive layer cannot be measured due to the influence of the damaged layer. On the other hand, when the “cluster ion etching method” using “Ar gas cluster ions (Arn ⁺ )” as etching ions is used, damage applied to the surface of the adhesive layer after etching is reduced, and a damaged layer is formed. Therefore, the surface of the adhesive layer after etching retains the molecular structure of the surface before etching. Therefore, the mass spectrum of the surface of the adhesive layer can be accurately measured by using TOF-SIMS.

  The schematic which shows the evaluation method of the component inclination structure in the thickness direction in the adhesive bond layer using TOF-SIMS in FIG. 1 is shown. (I) of FIG. 1 shows an example of a polarizing film that is a laminated optical film that can be produced in the present invention. In such a polarizing film, a transparent protective film 2 is laminated on both surfaces of a polarizer 1 with an adhesive layer 3 interposed therebetween. Has been. First, the transparent protective film 2 of the polarizing film shown in (I) (the upper transparent protective film 2 in FIG. 1 (I)) is horizontally cut with a microtome to reduce the thickness of the transparent protective film 2 in contact with the adhesive layer 3. ((II)). Next, as shown in (III), the composition of the surface is analyzed by measuring the mass spectrum of the surface of the thin transparent protective film 2 using TOF-SIMS. Next, as shown in (IV), after etching the surface of the transparent protective film 2 thinly cut using the “cluster ion etching method”, the composition of the surface is analyzed using TOF-SIMS. Further, as shown in (V), the surface of the transparent protective film 2 is deposited by etching the surface of the transparent protective film 2 using the “cluster ion etching method”, and TOF-SIMS Is used to analyze the composition of the surface. Thereafter, the etching process using the “cluster ion etching method” and the analysis of the composition of the surface of the deposited adhesive layer 3 are repeated using TOF-SIMS, and etching is performed until the surface finally reaches the polarizer surface. Processing and analysis of the composition of the surface of the adhesive layer 3 (and the polarizer 1) are continued. By the method demonstrated above, in this invention, the component inclination structure in the thickness direction in the adhesive bond layer interposed between a transparent protective film and a polarizer can be confirmed.

  As the A component having a log Pow of −1 to 1, among the radical polymerizable compounds described above, a compound having a log Pow of −1 to 1 can be arbitrarily used. Specifically, for example, hydroxyethyl acrylamide ( Product name “HEAA”, manufactured by Kojin Co., Ltd., LogPow; −0.56), N-vinylformamide (trade name “Beamset 770”, manufactured by Arakawa Chemical Co., Ltd., LogPow; −0.25), acryloylmorpholine (product) Name “ACMO”, manufactured by Kojin Co., Ltd., LogPow; −0.20), γ-butyrolactone acrylate (trade name “GBLA”, manufactured by Osaka Organic Chemical Industry Co., Ltd., LogPow; 0.19), acrylic acid dimer (trade name) “Β-CEA”, manufactured by Daicel Corporation, LogPow; 0.2), N-vinylpyrrolidone (trade name “NVP”, manufactured by Nippon Shokubai Co., Ltd., LogPo) w; 0.24), acetoacetoxyethyl methacrylate (trade name “AAEM”, manufactured by Nippon Synthetic Chemical Co., Ltd., LogPow; 0.27), 2-hydroxyethyl acrylate (trade name “HEA”, manufactured by Osaka Organic Chemical Industries, Ltd., LogPow; 0.28), glycidyl methacrylate (trade name “Light Ester G”, manufactured by Kyoeisha Chemical Co., Ltd., LogPow; 0.57), dimethylacrylamide (trade name “DMAA”, manufactured by Kojin Co., Ltd., LogPow; 0.58), Tetrahydrofurfuryl alcohol acrylic acid multimer ester (trade name “Biscoat # 150D”, manufactured by Osaka Organic Chemical Industry Co., Ltd., LogPow; 0.60), 4-hydroxybutyl acrylate (trade name “4-HBA”, Osaka Organic Chemical Industries, Ltd.) Company, LogPow; 0.68), acrylic acid (trade name “acrylic acid”) Manufactured by Mitsubishi Chemical Corporation, LogPow; 0.69), triethylene glycol diacrylate (trade name "LIGHT ACRYLATE 3EG-A" manufactured by Kyoeisha Chemical Co., Ltd., LogPow; 0.72), and the like. Among these, in this invention, it is preferable to use a (meth) acrylamide derivative as A component whose logPow is -1 to 1, and also use of hydroxyethyl acrylamide, acryloyl morpholine, or dimethyl acrylamide is preferable. Other than (meth) acrylamide derivatives, 4-hydroxybutyl acrylate is preferably used.

  When the first optical film is a polarizer, the first active energy ray-curable adhesive composition preferably contains an A component having a logPow of −1 to 1. Furthermore, in order to improve the adhesive strength and water resistance of the adhesive layer, when the total amount of the first active energy ray-curable adhesive composition is 100% by weight, the log Pow is −1 to 1, The content is preferably 5 to 95% by weight, and more preferably 30 to 80% by weight.

  In the present invention, when a component having a log Pow of 2 to 7 is a B component, the B component exhibits high hydrophobicity. As the B component having a log Pow of 2 to 7, a compound having a log Pow of 2 to 7 among the radical polymerizable compounds described above can be arbitrarily used. Specifically, for example, dicyclopentenyl acrylate- (Trade name “Fancryl FA-511AS”, manufactured by Hitachi Chemical Co., Ltd., LogPow; 2.26), butyl acrylate (trade name “butyl acrylate”, manufactured by Mitsubishi Chemical Corporation, LogPow; 2.35), 1, 6-hexanediol diacrylate (trade name “Light acrylate 1.6HX-A”, manufactured by Kyoeisha Chemical Co., Ltd., LogPow; 2.43), dicyclopentanyl acrylate (trade name “Fancryl FA-513AS”, Hitachi Chemical Co., Ltd., LogPow; 2.58), dimethylol-tricyclodecane diacrylate (trade name “Light Acrylate DC”) -A ", manufactured by Kyoeisha Chemical Co., Ltd., LogPow; 3.05), isobornyl acrylate (trade name" Light Acrylate IB-XA ", manufactured by Kyoeisha Chemical Co., Ltd., LogPow; 3.27), hydroxypivalate neopentyl glycol acrylic Acid adduct (trade name “light acrylate HPP-A”, manufactured by Kyoeisha Chemical Co., Ltd., LogPow; 3.35), 1,9-nonanediol diacrylate (trade name “light acrylate 1,9ND-A”, Kyoeisha Chemical Co., Ltd.) Manufactured by LogPow; 3.68), o-phenylphenol EO modified acrylate (trade name “Fancryl FA-301A”, manufactured by Hitachi Chemical Co., Ltd., LogPow; 3.98), 2-ethylhexyloxetane (trade name “Aron Oxetane OXT” -212 ", manufactured by Toagosei Co., Ltd., LogPow; 4.24), Bisuf Nord-A-diglycidyl ether (trade name “JER828”, manufactured by Mitsubishi Chemical Corporation, LogPow; 4.76), bisphenol A EO6 molar modified diacrylate (trade name “FA-326A”, manufactured by Hitachi Chemical Co., Ltd., LogPow; 4 .84), bisphenol A EO4 mole modified diacrylate (trade name “FA-324A”, manufactured by Hitachi Chemical Co., Ltd., LogPow; 5.15), bisphenol A PO2 mole modified diacrylate (trade name “FA-P320A”, Hitachi Chemical) LogPow; 6.10), bisphenol A PO3 molar modified diacrylate (trade name “FA-P323A”, Hitachi Chemical, LogPow; 6.26), bisphenol A PO4 molar modified diacrylate (trade name “FA”) -P324A ", manufactured by Hitachi Chemical Co., Ltd., LogPow; 6.4 ), And the like. Among these, in this invention, it is preferable to use polyfunctional (meth) acrylate as B component whose logPow is 2-7, Furthermore, 1, 6- hexanediol diacrylate), dimethylol- tricyclodecanedi. Acrylate, hydroxypivalate neopentyl glycol acrylic acid adduct, 1,9-nonanediol diacrylate, 2-ethylhexyl oxetane, bisphenol-A-diglycidyl ether, bisphenol A EO6 mole modified diacrylate, bisphenol A EO4 mole modified diacrylate The use of bisphenol A PO2 mole modified diacrylate, bisphenol A PO3 mole modified diacrylate, or bisphenol A PO4 mole modified diacrylate is preferred.

  When the second optical film is a transparent protective film, the second active energy ray-curable adhesive composition preferably contains a B component having a logPow of 2 to 7. Furthermore, in order to improve the adhesive strength and water resistance of the adhesive layer, when the total amount of the second active energy ray-curable adhesive composition is 100% by weight, the log Pow is 2-7. The content is preferably 30 to 95% by weight, and more preferably 50 to 80% by weight.

  When an active energy ray-curable adhesive composition uses an electron beam or the like as the active energy ray, the active energy ray-curable adhesive composition does not need to contain a photopolymerization initiator. When ultraviolet rays or visible rays are used for the energy rays, it is preferable to contain a photopolymerization initiator.

<Photopolymerization initiator>
The photopolymerization initiator in the case of using the radical polymerizable compound is appropriately selected depending on the active energy ray. In the case of curing by ultraviolet light or visible light, a photopolymerization initiator for ultraviolet light or visible light cleavage is used. Although the said photoinitiator may be used independently, when mixing and using a some photoinitiator, since a cure rate and curability can be adjusted, it is preferable. Examples of the photopolymerization initiator include benzophenone compounds such as benzyl, benzophenone, benzoylbenzoic acid, and 3,3′-dimethyl-4-methoxybenzophenone; 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2) -Propyl) ketone, [alpha] -hydroxy- [alpha], [alpha] '-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, 1-hydroxycyclohexyl phenyl ketone, 1- [4- (2-hydroxyethoxy) -phenyl]- 2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane Aromatic ketone compounds such as -1-one; methoxyacetophenone, 2,2-dimeth Acetophenone compounds such as ci-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1- [4- (methylthio) -phenyl] -2-morpholinopropane-1; benzoin methyl Benzoin ether compounds such as ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, and anisoin methyl ether; aromatic ketal compounds such as benzyldimethyl ketal; aromatics such as 2-naphthalenesulfonyl chloride Sulfonyl chloride compounds; photoactive oxime compounds such as 1-phenone-1,1-propanedione-2- (o-ethoxycarbonyl) oxime; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2, 4-dimethylthioxa Thioxanthone compounds such as Son, Isopropylthioxanthone, 2,4-Dichlorothioxanthone, 2,4-Diethylthioxanthone, 2,4-Diisopropylthioxanthone, Dodecylthioxanthone; Camphorquinone; Halogenated ketone; Acyl Phosphinoxide; acyl phosphonate and the like.

  The blending amount of the photopolymerization initiator is 20% by weight or less when the total amount of the active energy ray-curable adhesive composition is 100% by weight. The blending amount of the photopolymerization initiator is preferably 0.01 to 20% by weight, more preferably 0.05 to 10% by weight, and further preferably 0.1 to 5% by weight.

  Further, when the curable adhesive for laminated optical film of the present invention is used in a visible light curable type containing a radical polymerizable compound as a curable component, it is a photopolymerization initiator particularly sensitive to light of 380 nm or more. Is preferably used. A photopolymerization initiator that is highly sensitive to light of 380 nm or more will be described later.

  As said photoinitiator, the compound represented by following General formula (1);

(Wherein R ¹ and R ² represent —H, —CH ₂ CH ₃ , —iPr or Cl, and R ¹ and R ² may be the same or different), respectively, or a general formula ( It is preferable to use together the compound represented by 1) and a photopolymerization initiator that is highly sensitive to light of 380 nm or more, which will be described later. When the compound represented by the general formula (1) is used, the adhesiveness is excellent as compared with a case where a photopolymerization initiator having high sensitivity to light of 380 nm or more is used alone. Among the compounds represented by the general formula (1), diethylthioxanthone in which R ¹ and R ² are —CH ₂ CH ₃ is particularly preferable. The composition ratio of the compound represented by the general formula (1) in the adhesive is preferably 0.1 to 5% by weight when the total amount of the active energy ray-curable adhesive composition is 100% by weight. 0.5 to 4% by weight is more preferable, and 0.9 to 3% by weight is even more preferable.

  Moreover, it is preferable to add a polymerization initiation assistant as required. Examples of polymerization initiators include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, and the like. Among them, ethyl 4-dimethylaminobenzoate is particularly preferable. When using a polymerization initiation aid, the amount added is usually 0 to 5 parts by weight, preferably 0 to 4 parts by weight, most preferably 0 to 3 parts by weight, based on 100 parts by weight of the total amount of the curable component. is there.

  Moreover, a well-known photoinitiator can be used together as needed. Since the transparent protective film having UV absorbing ability does not transmit light of 380 nm or less, it is preferable to use a photopolymerization initiator that is highly sensitive to light of 380 nm or more as the photopolymerization initiator. Specifically, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 2- (Dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine Oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole) 1-yl) -phenyl) titanium and the like.

  In particular, as a photopolymerization initiator, in addition to the photopolymerization initiator of the general formula (1), a compound represented by the following general formula (2);

Wherein R ³ , R ⁴ and R ⁵ represent —H, —CH ₃ , —CH ₂ CH ₃ , —iPr or Cl, and R ³ , R ⁴ and R ⁵ may be the same or different. It is preferable to use it. As the compound represented by the general formula (2), 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (trade name: IRGACURE907 manufacturer: BASF) which is also a commercially available product is suitable. Can be used. In addition, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (trade name: IRGACURE369 manufacturer: BASF), 2- (dimethylamino) -2-[(4-methylphenyl) Methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone (trade name: IRGACURE379 manufacturer: BASF) is preferable because of its high sensitivity.

  In the present invention, among the photopolymerization initiators, it is preferable to use a hydroxyl group-containing photopolymerization initiator. When the active energy ray-curable adhesive composition contains a hydroxyl group-containing photopolymerization initiator as a polymerization initiator, the solubility in the adhesive layer having a high concentration of the component A on the polarizer side is increased, and the adhesive layer The curability of is increased. Examples of the photopolymerization initiator having a hydroxyl group include 2-methyl-2-hydroxypropiophenone (trade name “DAROCUR1173”, manufactured by BASF), 1-hydroxycyclohexyl phenyl ketone (trade name “IRGACURE184”, manufactured by BASF). ), 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one (trade name “IRGACURE2959”, manufactured by BASF), 2-hydroxy-1- Examples include {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one (trade name “IRGACURE127”, manufactured by BASF). In particular, 1-hydroxycyclohexyl phenyl ketone is more preferable because it has particularly excellent solubility in an adhesive layer having a high concentration of component A.

<Radical polymerizable compound having active methylene group and radical polymerization initiator having hydrogen abstraction action>
In the active energy ray-curable adhesive composition, when a radical polymerizable compound having an active methylene group is used as the radical polymerizable compound, it is preferably used in combination with a radical polymerization initiator having a hydrogen abstracting action. According to such a configuration, the adhesiveness of the adhesive layer of the polarizing film is remarkably improved even in a high humidity environment or immediately after being taken out from water (non-dried state). The reason for this is not clear, but the following causes are considered. That is, the radical polymerizable compound having an active methylene group is taken into the main chain and / or side chain of the base polymer in the adhesive layer while polymerizing together with other radical polymerizable compounds constituting the adhesive layer. An agent layer is formed. In such a polymerization process, when a radical polymerization initiator having a hydrogen abstracting action is present, a base polymer constituting the adhesive layer is formed, while hydrogen is extracted from the radical polymerizable compound having an active methylene group to form a methylene group. Radicals are generated. And the methylene group which the radical generate | occur | produced, and the hydroxyl group of polarizers, such as PVA, react, and a covalent bond is formed between an adhesive bond layer and a polarizer. As a result, it is speculated that the adhesiveness of the adhesive layer of the polarizing film is remarkably improved even in a non-dry state.

In the present invention, examples of the radical polymerization initiator having a hydrogen abstracting action include thioxanthone radical polymerization initiators and benzophenone radical polymerization initiators. The radical polymerization initiator is preferably a thioxanthone radical polymerization initiator. Examples of the thioxanthone radical polymerization initiator include compounds represented by the above general formula (1). Specific examples of the compound represented by the general formula (1) include thioxanthone, dimethylthioxanthone, diethylthioxanthone, isopropylthioxanthone, and chlorothioxanthone. Among the compounds represented by the general formula (1), diethylthioxanthone in which R ¹ and R ² are —CH ₂ CH ₃ is particularly preferable.

  In the active energy ray-curable adhesive composition, when the radical polymerizable compound having an active methylene group and a radical polymerization initiator having a hydrogen abstracting action are contained, the total amount of the curable component is 100% by weight. In this case, it is preferable to contain 1 to 50% by weight of the radical polymerizable compound having an active methylene group and 0.1 to 10 parts by weight of the radical polymerization initiator with respect to 100 parts by weight of the total amount of the curable component.

  As described above, in the present invention, a radical is generated in the methylene group of a radical polymerizable compound having an active methylene group in the presence of a radical polymerization initiator having a hydrogen abstraction function, and the methylene group and a polarizer such as PVA are used. React with a hydroxyl group to form a covalent bond. Therefore, in order to generate radicals in the methylene group of the radical polymerizable compound having an active methylene group and to sufficiently form such a covalent bond, when the total amount of the curable component is 100% by weight, the radical having an active methylene group. The content of the polymerizable compound is preferably 1 to 50% by weight, and more preferably 3 to 30% by weight. In order to sufficiently improve the water resistance and improve the adhesion in a non-dry state, the radical polymerizable compound having an active methylene group is preferably 1% by weight or more. On the other hand, if it exceeds 50% by weight, the adhesive layer may be poorly cured. Moreover, it is preferable to contain 0.1-10 weight part with respect to 100 weight part of whole quantity of a sclerosing | hardenable component, and, as for the radical polymerization initiator which has a hydrogen abstraction effect | action, it is further contained 0.3-9 weight part. More preferred. In order for the hydrogen abstraction reaction to proceed sufficiently, it is preferable to use 0.1 parts by weight or more of a radical polymerization initiator. On the other hand, if it exceeds 10 parts by weight, it may not completely dissolve in the composition.

<Cationic polymerization curable adhesive>
Examples of the curable component of the cationic polymerization curable adhesive include compounds having an epoxy group or an oxetanyl group. The compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various generally known curable epoxy compounds can be used. As a preferable epoxy compound, a compound having at least two epoxy groups and at least one aromatic ring in the molecule (aromatic epoxy compound), or at least two epoxy groups in the molecule, at least one of them. Examples thereof include a compound (alicyclic epoxy compound) formed between two adjacent carbon atoms constituting an alicyclic ring. However, the active energy ray-curable adhesive composition has an octanol / water partition coefficient even in the case where a cationic polymerization curable adhesive is used to realize a component gradient structure in the adhesive layer in the adhesive layer. It is necessary to contain an A component whose logPow is −1 to 1 and a B component whose logPow is 2 to 7.

<Photocationic polymerization initiator>
The cationic polymerization curable adhesive contains the epoxy compound and the oxetane compound described above as curable components, and these are cured by cationic polymerization, and therefore, a photocationic polymerization initiator is blended therein. This cationic photopolymerization initiator generates a cationic species or a Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, and starts a polymerization reaction of an epoxy group or an oxetanyl group.

<Other ingredients>
The active energy ray-curable adhesive composition according to the present invention may contain the following components.

<Acrylic oligomer>
The active energy ray-curable adhesive composition used in the present invention is an acrylic composition obtained by polymerizing a (meth) acrylic monomer in addition to the curable component of the radical polymerizable compound or the cationic polymerization curable adhesive. An oligomer can be contained. When the active energy ray-curable adhesive composition contains an acrylic oligomer obtained by polymerizing a non-polymerizable (meth) acrylic monomer, the component of the adhesive composition interposed between the polarizer and the transparent protective film The uneven distribution easily proceeds, and the component gradient structure in which the concentration of the component A changes in the thickness direction is more easily obtained. For this reason, since adhesiveness with the polarizer and transparent protective film of an adhesive bond layer, and water resistance further improve, it is preferable. Furthermore, by containing an acrylic oligomer component in the active energy ray-curable adhesive composition, the shrinkage of curing when the active energy ray is irradiated and cured on the composition is reduced, and the adhesive, the polarizer, Interfacial stress with an adherend such as a transparent protective film can be reduced. As a result, it is possible to suppress a decrease in adhesiveness between the adhesive layer and the adherend. In order to more surely obtain the component gradient structure of the cured product layer (adhesive layer), and to sufficiently suppress the curing shrinkage, the total amount of the active energy ray-curable adhesive composition was set to 100% by weight. When the content of the acrylic oligomer is preferably 5 to 30% by weight, more preferably 10 to 20% by weight.

  The active energy ray-curable adhesive composition preferably has a low viscosity in consideration of workability and uniformity during coating. Therefore, an acrylic oligomer (A) obtained by polymerizing a (meth) acrylic monomer. It is also preferable that the viscosity is low. The acrylic oligomer having a low viscosity preferably has a weight average molecular weight (Mw) of 15000 or less, more preferably 10,000 or less, and particularly preferably 5000 or less. On the other hand, in order to further promote the uneven distribution of the components of the adhesive composition interposed between the polarizer and the transparent protective film, the weight average molecular weight (Mw) of the acrylic oligomer (A) is preferably 500 or more, It is more preferably 1000 or more, and particularly preferably 1500 or more. Specific examples of the (meth) acrylic monomer constituting the acrylic oligomer (A) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, 2 -Methyl-2-nitropropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, S-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, t-pentyl (meth) acrylate, 3-pentyl (meth) acrylate, 2,2-dimethylbutyl (meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) acrylate, n-octyl (meth) acrylate, 2 -Ethylhexyl (meth) acryl (Meth) acrylic acid (carbon number 1-20) alkyl esters such as 4-methyl-2-propylpentyl (meth) acrylate and N-octadecyl (meth) acrylate, and further, for example, cycloalkyl (meth) Acrylate (eg, cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, etc.), aralkyl (meth) acrylate (eg, benzyl (meth) acrylate, etc.), polycyclic (meth) acrylate (eg, 2-isobornyl (meth) Acrylate, 2-norbornylmethyl (meth) acrylate, 5-norbornen-2-yl-methyl (meth) acrylate, 3-methyl-2-norbornylmethyl (meth) acrylate, etc.), hydroxyl group-containing (meth) Acrylic esters (e.g., Droxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2,3-dihydroxypropylmethyl-butyl (meth) methacrylate, etc.), alkoxy group or phenoxy group-containing (meth) acrylic acid esters (2-methoxyethyl ( (Meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, etc.), epoxy Group-containing (meth) acrylic acid esters (for example, glycidyl (meth) acrylate), halogen-containing (meth) acrylic acid esters (for example, 2,2,2-trifluoroethyl (meth) acrylate, 2,2 , 2-trifluoroethylethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate, etc.), alkylaminoalkyl (Meth) acrylate (for example, dimethylaminoethyl (meth) acrylate etc.) etc. are mentioned. These (meth) acrylates can be used alone or in combination of two or more. Specific examples of the acrylic oligomer (A) include “ARUFON” manufactured by Toagosei Co., Ltd., “Act Flow” manufactured by Soken Chemical Co., Ltd., “JONCRYL” manufactured by BASF Japan.

  When the acrylic oligomer (A) is a liquid, it is preferably used because it is not necessary to consider the solubility in the adhesive composition. The acrylic oligomer (A) is usually a liquid when the glass transition temperature (Tg) is less than 25 ° C. In order to achieve both compatibility with the adhesive composition and uneven distribution of components in the adhesive layer, the acrylic oligomer (A) preferably contains a polar functional group. Examples of the polar functional group include a hydroxyl group, an epoxy group, a carboxyl group, and an alkoxysilyl group. Specific examples include “ARUFON UH series”, “ARUFON UC series”, “ARUFON UF series”, “ARUFON UG series”, “ARUFON US series” (all manufactured by Toagosei Co., Ltd.). Especially, since the adhesive improvement by interaction with a polarizer is anticipated, it is preferable to contain an epoxy group. Specific examples include “ARUFON UG-4000” and “ARUFON UG-4010” (both manufactured by Toagosei Co., Ltd.).

<Photo acid generator>
The active energy ray-curable adhesive composition can contain a photoacid generator. When the active energy ray-curable resin composition contains a photoacid generator, the water resistance and durability of the adhesive layer can be dramatically improved as compared with the case where no photoacid generator is contained. . The photoacid generator can be represented by the following general formula (3).

General formula (3)
(However, L ⁺ represents an arbitrary onium cation. X ⁻ represents PF6 ₆ ⁻ , SbF.
_It represents a counter anion selected from the group consisting of ₆ ⁻ , AsF ₆ ⁻ , SbCl ₆ ⁻ , BiCl ₅ ⁻ , SnCl ₆ ⁻ , ClO ₄ ⁻ , dithiocarbamate anion, and SCN—. )
Preferred examples of the onium cation structure as the onium cation L ⁺ constituting the general formula (3) include onium cations selected from the following general formulas (4) to (12).

General formula (4)

General formula (5)

General formula (6)

General formula (7)

General formula (8)

General formula (9)

General formula (10)

Formula (11)

Formula (12)
(In the general formulas (4) to (12), R ¹ , R ² and R ³ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, substituted or An unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heterocyclic oxy group, a substituted or unsubstituted acyl group, R ⁴ represents a group selected from a substituted or unsubstituted carbonyloxy group, a substituted or unsubstituted oxycarbonyl group, or a halogen atom, and R ⁴ represents a group similar to the groups described in R ¹ , R ² and R ^3. .R ⁵ is a substituted or unsubstituted alkyl group, is .R ⁶ and R ⁷ represents a substituted or unsubstituted alkylthio group, independently, be substituted Represents an unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, and R represents a halogen atom, a hydroxyl group, a carboxyl group, a mercapto group, a cyano group, a nitro group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted group. Alkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted aryl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted alkoxyl group, substituted or unsubstituted aryloxy group, substituted or unsubstituted Heterocyclic oxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted arylthio group, substituted or unsubstituted heterocyclic thio group, substituted or unsubstituted acyl group, substituted or unsubstituted carbonyloxy group, substituted or ^.Ar 4 represent either a non-substituted oxycarbonyl group, Ar Represents a substituted or unsubstituted aryl group, .X represent either a substituted or unsubstituted heterocyclic group, an oxygen or sulfur atom .i is .j is 0-4 represents an integer of 0 to 5 K represents an integer of 0 to ^3. Adjacent Rs, Ar ⁴ and Ar ⁵ , R ² and R ³ , R ² and R ⁴ , R ³ and R ⁴ , R ¹ and R ² , R ¹ and R ³ , R ¹ and R ⁴ , R ¹ and R, or R ¹ and R ⁵ may be a cyclic structure bonded to each other.)

Onium cation (sulfonium cation) corresponding to general formula (4):
Dimethylphenylsulfonium, dimethyl (o-fluorophenyl) sulfonium, dimethyl (m-chlorophenyl) sulfonium, dimethyl (p-bromophenyl) sulfonium, dimethyl (p-cyanophenyl) sulfonium, dimethyl (m-nitrophenyl) sulfonium, dimethyl ( 2,4,6-tribromophenyl) sulfonium, dimethyl (pentafluorophenyl) sulfonium, dimethyl (p- (trifluoromethyl) phenyl) sulfonium, dimethyl (p-hydroxyphenyl) sulfonium, dimethyl (p-mercaptophenyl) sulfonium , Dimethyl (p-methylsulfinylphenyl) sulfonium, dimethyl (p-methylsulfonylphenyl) sulfonium, dimethyl (o-acetylphenyl) sulfonium Dimethyl (o-benzoylphenyl) sulfonium, dimethyl (p-methylphenyl) sulfonium, dimethyl (p-isopropylphenyl) sulfonium, dimethyl (p-octadecylphenyl) sulfonium, dimethyl (p-cyclohexylphenyl) sulfonium, dimethyl (p-methoxy) Phenyl) sulfonium, dimethyl (o-methoxycarbonylphenyl) sulfonium, dimethyl (p-phenylsulfanylphenyl) sulfonium, (7-methoxy-2-oxo-2H-chromen-4-yl) dimethylsulfonium, (4-methoxynaphthalene- 1-yl) dimethylsulfonium, dimethyl (p-isopropoxycarbonylphenyl) sulfonium, dimethyl (2-naphthyl) sulfonium, dimethyl (9-anthryl) Rufonium, diethylphenylsulfonium, methylethylphenylsulfonium, methyldiphenylsulfonium, triphenylsulfonium, diisopropylphenylsulfonium, diphenyl (4-phenylsulfanyl-phenyl) -sulfonium, 4,4′-bis (diphenylsulfonium) diphenyl sulfide, 4, 4′-bis [di [(4- (2-hydroxy-ethoxy) -phenyl)] sulfonium]] diphenyl sulfide, 4,4′-bis (diphenylsulfonium) biphenylene, diphenyl (o-fluorophenyl) sulfonium, diphenyl ( m-chlorophenyl) sulfonium, diphenyl (p-bromophenyl) sulfonium, diphenyl (p-cyanophenyl) sulfonium, diphenyl (m-nitrophenyl) ) Sulfonium, diphenyl (2,4,6-tribromophenyl) sulfonium, diphenyl (pentafluorophenyl) sulfonium, diphenyl (p- (trifluoromethyl) phenyl) sulfonium, diphenyl (p-hydroxyphenyl) sulfonium, diphenyl (p -Mercaptophenyl) sulfonium, diphenyl (p-methylsulfinylphenyl) sulfonium, diphenyl (p-methylsulfonylphenyl) sulfonium, diphenyl (o-acetylphenyl) sulfonium, diphenyl (o-benzoylphenyl) sulfonium, diphenyl (p-methylphenyl) ) Sulfonium, diphenyl (p-isopropylphenyl) sulfonium, diphenyl (p-octadecylphenyl) sulfonium, diphenyl (p-si Rohexylphenyl) sulfonium, diphenyl (p-methoxyphenyl) sulfonium, diphenyl (o-methoxycarbonylphenyl) sulfonium, diphenyl (p-phenylsulfanylphenyl) sulfonium, (7-methoxy-2-oxo-2H-chromene-4- Yl) diphenylsulfonium, (4-methoxynaphthalen-1-yl) diphenylsulfonium, diphenyl (p-isopropoxycarbonylphenyl) sulfonium, diphenyl (2-naphthyl) sulfonium, diphenyl (9-anthryl) sulfonium, ethyldiphenylsulfonium, methyl Ethyl (o-tolyl) sulfonium, methyldi (p-tolyl) sulfonium, tri (p-tolyl) sulfonium, diisopropyl (4-phenylsulfanyl) Nyl) sulfonium, diphenyl (2-thienyl) sulfonium, diphenyl (2-furyl) sulfonium, diphenyl (9-ethyl-9Hcarbazol-3-yl) sulfonium, and the like, but are not limited thereto. .

Onium cation corresponding to general formula (5) (sulfoxonium cation):
Dimethylphenylsulfoxonium, dimethyl (o-fluorophenyl) sulfoxonium, dimethyl (m-chlorophenyl) sulfoxonium, dimethyl (p-bromophenyl) sulfoxonium, dimethyl (p-cyanophenyl) sulfoxonium, dimethyl (M-nitrophenyl) sulfoxonium, dimethyl (2,4,6-tribromophenyl) sulfoxonium, dimethyl (pentafluorophenyl) sulfoxonium, dimethyl (p- (trifluoromethyl) phenyl) sulfoxonium , Dimethyl (p-hydroxyphenyl) sulfoxonium, dimethyl (p-mercaptophenyl) sulfoxonium, dimethyl (p-methylsulfinylphenyl) sulfoxonium, dimethyl (p-methylsulfonylphenyl) sulfoxo , Dimethyl (o-acetylphenyl) sulfoxonium, dimethyl (o-benzoylphenyl) sulfoxonium, dimethyl (p-methylphenyl) sulfoxonium, dimethyl (p-isopropylphenyl) sulfoxonium, dimethyl (p- Octadecylphenyl) sulfoxonium, dimethyl (p-cyclohexylphenyl) sulfoxonium, dimethyl (p-methoxyphenyl) sulfoxonium, dimethyl (o-methoxycarbonylphenyl) sulfoxonium, dimethyl (p-phenylsulfanylphenyl) sulfo Xonium, (7-methoxy-2-oxo-2H-chromen-4-yl) dimethylsulfoxonium, (4-methoxynaphthalen-1-yl) dimethylsulfoxonium, dimethyl (p-isopropoxyca) Bonylphenyl) sulfoxonium, dimethyl (2-naphthyl) sulfoxonium, dimethyl (9-anthryl) sulfoxonium, diethylphenylsulfoxonium, methylethylphenylsulfoxonium, methyldiphenylsulfoxonium, triphenylsulfoxonium Ni, diisopropylphenylsulfoxonium, diphenyl (4-phenylsulfanyl-phenyl) -sulfoxonium, 4,4′-bis (diphenylsulfoxonium) diphenyl sulfide, 4,4′-bis [di [(4- ( 2-hydroxy-ethoxy) -phenyl)] sulfoxonium] diphenyl sulfide, 4,4′-bis (diphenylsulfoxonium) biphenylene, diphenyl (o-fluorophenyl) sulfoxonium, diphenyl (m-chloro) Phenyl) sulfoxonium, diphenyl (p-bromophenyl) sulfoxonium, diphenyl (p-cyanophenyl) sulfoxonium, diphenyl (m-nitrophenyl) sulfoxonium, diphenyl (2,4,6-tribromophenyl) ) Sulfoxonium, diphenyl (pentafluorophenyl) sulfoxonium, diphenyl (p- (trifluoromethyl) phenyl) sulfoxonium, diphenyl (p-hydroxyphenyl) sulfoxonium, diphenyl (p-mercaptophenyl) sulfoxo Ni, diphenyl (p-methylsulfinylphenyl) sulfoxonium, diphenyl (p-methylsulfonylphenyl) sulfoxonium, diphenyl (o-acetylphenyl) sulfoxonium, diphenyl (o-benzoy) Ruphenyl) sulfoxonium, diphenyl (p-methylphenyl) sulfoxonium, diphenyl (p-isopropylphenyl) sulfoxonium, diphenyl (p-octadecylphenyl) sulfoxonium, diphenyl (p-cyclohexylphenyl) sulfoxonium, Diphenyl (p-methoxyphenyl) sulfoxonium, diphenyl (o-methoxycarbonylphenyl) sulfoxonium, diphenyl (p-phenylsulfanylphenyl) sulfoxonium, (7-methoxy-2-oxo-2H-chromene-4- Yl) diphenylsulfoxonium, (4-methoxynaphthalen-1-yl) diphenylsulfoxonium, diphenyl (p-isopropoxycarbonylphenyl) sulfoxonium, diphenyl (2-naphthyl) Sulfoxonium, diphenyl (9-anthryl) sulfoxonium, ethyldiphenylsulfoxonium, methylethyl (o-tolyl) sulfoxonium, methyldi (p-tolyl) sulfoxonium, tri (p-tolyl) sulfoxonium , Diisopropyl (4-phenylsulfanylphenyl) sulfoxonium, diphenyl (2-thienyl) sulfoxonium, diphenyl (2-furyl) sulfoxonium, diphenyl (9-ethyl-9Hcarbazol-3-yl) sulfoxonium, etc. However, it is not limited to these.

Onium cation (phosphonium cation) corresponding to the general formula (6):
Examples of phosphonium cations:
Trimethylphenylphosphonium, triethylphenylphosphonium, tetraphenylphosphonium, triphenyl (p-fluorophenyl) phosphonium, triphenyl (o-chlorophenyl) phosphonium, triphenyl (m-bromophenyl) phosphonium, triphenyl (p-cyanophenyl) phosphonium , Triphenyl (m-nitrophenyl) phosphonium, triphenyl (p-phenylsulfanylphenyl) phosphonium, (7-methoxy-2-oxo-2H-chromen-4-yl) triphenylphosphonium, triphenyl (o-hydroxyphenyl) ) Phosphonium, triphenyl (o-acetylphenyl) phosphonium, triphenyl (m-benzoylphenyl) phosphonium, triphenyl (p-methylphenyl) phospho Phonium, triphenyl (p-isopropoxyphenyl) phosphonium, triphenyl (o-methoxycarbonylphenyl) phosphonium, triphenyl (1-naphthyl) phosphonium, triphenyl (9-anthryl) phosphonium, triphenyl (2-thienyl) phosphonium , Triphenyl (2-furyl) phosphonium, triphenyl (9-ethyl-9Hcarbazol-3-yl) phosphonium, and the like, but are not limited thereto.

Onium cation corresponding to general formula (7) (pyridinium cation):
Examples of pyridinium cations:
N-phenylpyridinium, N- (o-chlorophenyl) pyridinium, N- (m-chlorophenyl) pyridinium, N- (p-cyanophenyl) pyridinium, N- (o-nitrophenyl) pyridinium, N- (p-acetylphenyl) ) Pyridinium, N- (p-isopropylphenyl) pyridinium, N- (p-octadecyloxyphenyl) pyridinium, N- (p-methoxycarbonylphenyl) pyridinium, N- (9-anthryl) pyridinium, 2-chloro-1- Phenylpyridinium, 2-cyano-1-phenylpyridinium, 2-methyl-1-phenylpyridinium, 2-vinyl-1-phenylpyridinium, 2-phenyl-1-phenylpyridinium, 1,2-diphenylpyridinium, 2-methoxy- 1-phenylpi Dinium, 2-phenoxy-1-phenylpyridinium, 2-acetyl-1- (p-tolyl) pyridinium, 2-methoxycarbonyl-1- (p-tolyl) pyridinium, 3-fluoro-1-naphthylpyridinium, 4-methyl Examples thereof include, but are not limited to, -1- (2-furyl) pyridinium, N-methylpyridinium, N-ethylpyridinium, and the like.

Onium cation (quinolinium cation) corresponding to general formula (8):
Examples of quinolinium cations:
N-methylquinolinium, N-ethylquinolinium, N-phenylquinolinium, N-naphthylquinolinium, N- (o-chlorophenyl) quinolinium, N- (m-chlorophenyl) quinolinium, N- (p -Cyanophenyl) quinolinium, N- (o-nitrophenyl) quinolinium, N- (p-acetylphenyl) quinolinium, N- (p-isopropylphenyl) quinolinium, N- (p-octadecyloxyphenyl) quinolinium, N- ( p-methoxycarbonylphenyl) quinolinium, N- (9-anthryl) quinolinium, 2-chloro-1-phenylquinolinium, 2-cyano-1-phenylquinolinium, 2-methyl-1-phenylquinolinium, 2-vinyl-1-phenylquinolinium, 2-phenyl-1-phenyl Norinium, 1,2-diphenylquinolinium, 2-methoxy-1-phenylquinolinium, 2-phenoxy-1-phenylquinolinium, 2-acetyl-1-phenylquinolinium, 2-methoxycarbonyl-1 -Phenylquinolinium, 3-fluoro-1-phenylquinolinium, 4-methyl-1-phenylquinolinium, 2-methoxy-1- (p-tolyl) quinolinium, 2-phenoxy-1- (2- Furyl) quinolinium, 2-acetyl-1- (2-thienyl) quinolinium, 2-methoxycarbonyl-1-methylquinolinium, 3-fluoro-1-ethylquinolinium, 4-methyl-1-isopropylquinolinium However, it is not limited to these.

Onium cation (isoquinolinium cation) corresponding to the general formula (9):
Examples of isoquinolinium cations:
N-phenylisoquinolinium, N-methylisoquinolinium, N-ethylisoquinolinium, N- (o-chlorophenyl) isoquinolinium, N- (m-chlorophenyl) isoquinolinium, N- (p-cyanophenyl) Isoquinolinium, N- (o-nitrophenyl) isoquinolinium, N- (p-acetylphenyl) isoquinolinium, N- (p-isopropylphenyl) isoquinolinium, N- (p-octadecyloxyphenyl) isoquinolinium, N- (p-methoxycarbonyl) Phenyl) isoquinolinium, N- (9-anthryl) isoquinolinium, 1,2-diphenylisoquinolinium, N- (2-furyl) isoquinolinium, N- (2-thienyl) isoquinolinium, N-naphthylisoquinolinium, etc. To mention That, without being limited thereto.

Onium cation corresponding to general formula (10) (benzoxazolium cation, benzothiazolium cation):
Examples of benzoxazolium cations:
N-methylbenzoxazolium, N-ethylbenzoxazolium, N-naphthylbenzoxazolium, N-phenylbenzoxazolium, N- (p-fluorophenyl) benzoxazolium, N- (p- Chlorophenyl) benzoxazolium, N- (p-cyanophenyl) benzoxazolium, N- (o-methoxycarbonylphenyl) benzoxazolium, N- (2-furyl) benzoxazolium, N- (o -Fluorophenyl) benzoxazolium, N- (p-cyanophenyl) benzoxazolium, N- (m-nitrophenyl) benzoxazolium, N- (p-isopropoxycarbonylphenyl) benzoxazolium, N- (2-thienyl) benzoxazolium, N- (m-carboxyphenyl) ben Oxazolium, 2-mercapto-3-phenylbenzoxazolium, 2-methyl-3-phenylbenzoxazolium, 2-methylthio-3- (4-phenylsulfanylphenyl) benzoxazolium, 6-hydroxy-3- (P-tolyl) benzoxazolium, 7-mercapto-3-phenylbenzoxazolium, 4,5-difluoro-3-ethylbenzoxazolium, and the like can be mentioned, but are not limited thereto. Absent.

Examples of benzothiazolium cations:
N-methylbenzothiazolium, N-ethylbenzothiazolium, N-phenylbenzothiazolium, N- (1-naphthyl) benzothiazolium, N- (p-fluorophenyl) benzothiazolium, N -(P-chlorophenyl) benzothiazolium, N- (p-cyanophenyl) benzothiazolium, N- (o-methoxycarbonylphenyl) benzothiazolium, N- (p-tolyl) benzothiazolium, N- (o-fluorophenyl) benzothiazolium, N- (m-nitrophenyl) benzothiazolium, N- (p-isopropoxycarbonylphenyl) benzothiazolium, N- (2-furyl) benzothia Zorium, N- (4-methylthiophenyl) benzothiazolium, N- (4-phenylsulfanylphenyl) benzothiazo , N- (2-naphthyl) benzothiazolium, N- (m-carboxyphenyl) benzothiazolium, 2-mercapto-3-phenylbenzothiazolium, 2-methyl-3-phenylbenzothiazolium 2-methylthio-3-phenylbenzothiazolium, 6-hydroxy-3-phenylbenzothiazolium, 7-mercapto-3-phenylbenzothiazolium, 4,5-difluoro-3-phenylbenzothiazolium However, it is not limited to these.

Onium cation corresponding to general formula (11) (furyl or thienyl iodonium cation):
Difuryl iodonium, dithienyl iodonium, bis (4,5-dimethyl-2-furyl) iodonium, bis (5-chloro-2-thienyl) iodonium, bis (5-cyano-2-furyl) iodonium, bis (5- Nitro-2-thienyl) iodonium, bis (5-acetyl-2-furyl) iodonium, bis (5-carboxy-2-thienyl) iodonium, bis (5-methoxycarbonyl-2-furyl) iodonium, bis (5-phenyl) -2-furyl) iodonium, bis (5- (p-methoxyphenyl) -2-thienyl) iodonium, bis (5-vinyl-2-furyl) iodonium, bis (5-ethynyl-2-thienyl) iodonium, bis ( 5-cyclohexyl-2-furyl) iodonium, bis (5-hydroxy-2-thio) Nyl) iodonium, bis (5-phenoxy-2-furyl) iodonium, bis (5-mercapto-2-thienyl) iodonium, bis (5-butylthio-2-thienyl) iodonium, bis (5-phenylthio-2-thienyl) Although iodonium etc. can be mentioned, it is not limited to these.

Onium cation corresponding to general formula (12) (diaryliodonium cation):
Diphenyliodonium, bis (p-tolyl) iodonium, bis (p-octylphenyl) iodonium, bis (p-octadecylphenyl) iodonium, bis (p-octyloxyphenyl) iodonium, bis (p-octadecyloxyphenyl) iodonium, phenyl (P-octadecyloxyphenyl) iodonium, 4-isopropyl-4′-methyldiphenyliodonium, (4-isobutylphenyl) -p-tolyliodonium, bis (1-naphthyl) iodonium, bis (4-phenylsulfanylphenyl) iodonium, Phenyl (6-benzoyl-9-ethyl-9H-carbazol-3-yl) iodonium, (7-methoxy-2-oxo-2H-chromen-3-yl) -4'-isopropylphenyliodonium Although and the like, but is not limited thereto.

Next, the counter anion X ⁻ in the general formula (3) will be described.

The counter anion X ⁻ in the general formula (3) is not particularly limited in principle, but a non-nucleophilic anion is preferable. When the counter anion X ⁻ is a non-nucleophilic anion, the nucleophilic reaction in the cations coexisting in the molecule and various materials used in combination is unlikely to occur. As a result, the photoacid generator itself represented by the general formula (2) It is possible to improve the aging stability of a composition using the same. The non-nucleophilic anion here refers to an anion having a low ability to cause a nucleophilic reaction. Examples of such anions include PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , SbCl ₆ ⁻ , BiCl ₅ ⁻ , SnCl ₆ ⁻ , ClO ₄ ⁻ , dithiocarbamate anion, SCN ^{− and the} like.

Among the exemplary anions described above, particularly preferable ones as the general formula (3) in counter anion X- _is, ^PF 6 -, SbF ₆ ^- and AsF ₆ ^- and the like, particularly _preferably, ^PF 6 -, SbF ₆ ^- and the like.

Therefore, as a specific example of a preferable onium salt constituting the photoacid generator that can be used in the present invention, a specific example of the structure of the onium cation represented by the above general formulas (3) to (12) An onium salt composed of an anion selected from PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , SbCl ₆ ⁻ , BiCl ₅ ⁻ , SnCl ₆ ⁻ , ClO ₄ ⁻ , dithiocarbamate anion, and SCN ⁻ .

  Specifically, “Syracure UVI-6922”, “Syracure UVI-6974” (above, manufactured by Dow Chemical Japan Co., Ltd.), “Adekaoptomer SP150”, “Adekaoptomer SP152”, “Adekaoptomer” “SP170”, “Adekaoptomer SP172” (manufactured by ADEKA Corporation), “IRGACURE250” (manufactured by Ciba Specialty Chemicals), “CI-5102”, “CI-2855” (manufactured by Nippon Soda Co., Ltd.), “Sun-Aid SI-60L”, “Sun-Aid SI-80L”, “Sun-Aid SI-100L”, “Sun-Aid SI-110L”, “Sun-Aid SI-180L” (above, manufactured by Sanshin Chemical Co., Ltd.), “CPI-100P”, “CPI-100A” (San Apro Co., Ltd.), “WPI-069 , “WPI-113”, “WPI-116”, “WPI-041”, “WPI-044”, “WPI-054”, “WPI-055”, “WPAG-281”, “WPAG-567”, “ “WPAG-596” (manufactured by Wako Pure Chemical Industries, Ltd.) is a preferred specific example of the photoacid generator of the present invention.

  Content of a photo-acid generator is 10 weight part or less with respect to 100 weight part of whole quantity of a sclerosing | hardenable component, It is preferable that it is 0.01-10 weight part, It is 0.05-5 weight part. It is more preferable that the amount is 0.1 to 3 parts by weight.

<Compound containing either alkoxy group or epoxy group>
In the active energy ray-curable adhesive composition, a compound containing a photoacid generator and either an alkoxy group or an epoxy group can be used in combination.

(Compound having epoxy group and polymer)
When using a compound having one or more epoxy groups in the molecule or a polymer (epoxy resin) having two or more epoxy groups in the molecule, two functional groups having reactivity with the epoxy group are contained in the molecule. Two or more compounds may be used in combination. Here, examples of the functional group having reactivity with an epoxy group include a carboxyl group, a phenolic hydroxyl group, a mercapto group, a primary or secondary aromatic amino group, and the like. It is particularly preferable to have two or more of these functional groups in one molecule in consideration of three-dimensional curability.

  Examples of the polymer having one or more epoxy groups in the molecule include epoxy resins, bisphenol A type epoxy resins derived from bisphenol A and epichlorohydrin, bisphenol F type epoxy derived from bisphenol F and epichlorohydrin. Resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, alicyclic epoxy resin, diphenyl ether type epoxy resin, hydroquinone type epoxy resin, Polyfunctional epoxy resins such as naphthalene type epoxy resin, biphenyl type epoxy resin, fluorene type epoxy resin, trifunctional type epoxy resin and tetrafunctional type epoxy resin, There are lysidyl ester type epoxy resins, glycidyl amine type epoxy resins, hydantoin type epoxy resins, isocyanurate type epoxy resins, aliphatic chain epoxy resins, etc. These epoxy resins may be halogenated and hydrogenated. It may be. As commercially available epoxy resin products, for example, JER Coat 828, 1001, 801N, 806, 807, 152, 604, 630, 871, YX8000, YX8034, YX4000 manufactured by Japan Epoxy Resin Co., Ltd., Epicron manufactured by DIC Corporation 830, EXA835LV, HP4032D, HP820, EP4100 series, EP4000 series, EPU series, manufactured by ADEKA Co., Ltd., Celoxide series (2021, 2021P, 2083, 2085, 3000, etc.) manufactured by Daicel Chemical Industries, Ltd., Eporide series, EHPE Series, YD series, YDF series, YDCN series, YDB series, phenoxy resin (polyethylene synthesized from bisphenols and epichlorohydrin) B carboxymethyl having an epoxy group at both ends with polyether; YP series, etc.), Nagase ChemteX Corporation of Denacol series manufactured by Kyoeisha but Chemical Co. Epo light series, and the like are not limited thereto. Two or more of these epoxy resins may be used in combination. In calculating the glass transition temperature Tg of the adhesive layer, the compound having an epoxy group and the polymer are not included in the calculation.

(Compounds and polymers having an alkoxyl group)
The compound having an alkoxyl group in the molecule is not particularly limited as long as it has one or more alkoxyl groups in the molecule, and known compounds can be used. Representative examples of such compounds include melamine compounds, amino resins, and silane coupling agents. In calculating the glass transition temperature Tg of the adhesive layer, the compound and polymer having an alkoxyl group are not included in the calculation.

  The compounding amount of the compound containing either an alkoxy group or an epoxy group is usually 30 parts by weight or less with respect to 100 parts by weight of the total amount of the curable component, and if the content of the compound in the composition is too large, May deteriorate and impact resistance against drop test may deteriorate. The content of the compound in the composition is more preferably 20 parts by weight or less. On the other hand, from the viewpoint of water resistance, the compound preferably contains 2 parts by weight or more, more preferably 5 parts by weight or more in the composition.

<Silane coupling agent>
When the polarizing film curable adhesive of the present invention is an active energy ray-curable curable adhesive, it is preferable to use an active energy ray-curable compound as the silane coupling agent. Even if not, the same water resistance can be imparted.

  Specific examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, and 3-glycid as active energy ray-curable compounds. Xylpropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxy Examples thereof include silane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane.

  Preferable are 3-methacryloxypropyltrimethoxysilane and 3-acryloxypropyltrimethoxysilane.

  As a specific example of the silane coupling agent that is not active energy ray-curable, a silane coupling agent (D1) having an amino group is preferable. Specific examples of the silane coupling agent (D1) having an amino group include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane , Γ- (2-aminoethyl) aminopropylmethyldiethoxysilane, γ- (2-aminoethyl) aminopropyltriisopropoxysilane, γ- (2- (2-aminoethyl) aminoethyl) aminopropyltrimethoxysilane , Γ- (6-aminohexyl) Minopropyltrimethoxysilane, 3- (N-ethylamino) -2-methylpropyltrimethoxysilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane N-benzyl-γ-aminopropyltrimethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane, N-phenylaminomethyl Amino group-containing silanes such as trimethoxysilane, (2-aminoethyl) aminomethyltrimethoxysilane, N, N′-bis [3- (trimethoxysilyl) propyl] ethylenediamine; N- (1,3-dimethylbutyrate) Reden)- - it can be exemplified (triethoxysilyl) -1-propane ketimines type silanes such as amines.

  As the silane coupling agent (D1) having an amino group, only one type may be used, or a plurality of types may be used in combination. Among these, in order to ensure good adhesion, γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane , Γ- (2-aminoethyl) aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropylmethyldiethoxysilane, N- (1,3-dimethylbutylidene) -3- (triethoxysilyl)- 1-propanamine is preferred.

  The blending amount of the silane coupling agent is preferably in the range of 0.01 to 20 parts by weight, preferably 0.05 to 15 parts by weight, with respect to 100 parts by weight of the total amount of the curable component. More preferably, it is 10 parts by weight. This is because when the blending amount exceeds 20 parts by weight, the storage stability of the adhesive deteriorates, and when it is less than 0.1 part by weight, the effect of water-resistant adhesiveness is not sufficiently exhibited. When calculating the glass transition temperature Tg of the adhesive layer, the silane coupling agent is not included in the calculation.

  Specific examples of silane coupling agents that are not active energy ray-curable other than the above include 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropyltrimethoxy. Examples include silane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatopropyltriethoxysilane, imidazolesilane, and the like.

<Additives other than the above>
Moreover, various additives can be mix | blended with the active energy ray hardening-type adhesive composition used by 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; Plasticizers; UV absorbers; inorganic fillers; pigments; dyes and the like.

  Said additive is 0-10 weight part normally with respect to 100 weight part of whole quantity of a sclerosing | hardenable component, Preferably it is 0-5 weight part, Most preferably, it is 0-3 weight part.

<Viscosity of adhesive>
The active energy ray-curable adhesive composition used in the present invention contains the curable component, but the viscosity of the adhesive composition is 100 cp or less at 25 ° C. from the viewpoint of coatability. preferable. On the other hand, when the curable adhesive for polarizing film of the present invention exceeds 100 cp at 25 ° C., the temperature of the adhesive can be controlled at the time of coating and adjusted to 100 cp or less. A more preferable range of the viscosity is 1 to 80 cp, and most preferably 10 to 50 cp. The viscosity can be measured using an E-type viscometer TVE22LT manufactured by Toki Sangyo Co., Ltd.

  The active energy ray-curable adhesive composition used in the present invention preferably uses a material having low skin irritation as the curable component from the viewpoint of safety. Skin irritation is P.I. I. Judgment can be made with the index I. P. I. I is widely used to indicate the degree of skin injury and is measured by the Draise method. The measured value is displayed in the range of 0 to 8, and it is determined that the irritation is lower as the value is smaller. However, since the error of the measured value is large, it should be taken as a reference value. P. I. I is preferably 4 or less, more preferably 3 or less, and most preferably 2 or less.

  The laminated optical film manufactured by the manufacturing method according to the present invention includes at least the first optical film and the second optical film via an adhesive layer formed by curing the active energy ray-curable adhesive composition. It is a laminated one.

<Adhesive layer>
The thickness of the adhesive layer formed with the active energy ray-curable adhesive composition is preferably controlled to be 0.1 to 3 μm. The thickness of the adhesive layer is more preferably 0.3-2 μm, and further preferably 0.5-1.5 μm. Setting the thickness of the adhesive layer to 0.1 μm or more is preferable in order to suppress the occurrence of poor adhesion due to the cohesive force of the adhesive layer and the occurrence of poor appearance (bubbles) during lamination. On the other hand, if the adhesive layer is thicker than 3 μm, the polarizing film may not be able to satisfy the durability.

  The active energy ray-curable adhesive composition is preferably selected so that the Tg of the adhesive layer formed thereby is 60 ° C. or higher, more preferably 70 ° C. or higher. 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 is too high, the flexibility of the polarizing film is lowered. Therefore, the Tg of the adhesive layer is preferably 300 ° C. or lower, more preferably 240 ° C. or lower, and further 180 ° C. or lower. Tg (glass transition temperature) is measured under the following measurement conditions using a TA Instruments dynamic viscoelasticity measuring device RSAIII.

Sample size: width 10mm, length 30mm,
Clamp distance 20mm,
Measurement mode: Tensile, Frequency: 1 Hz, Temperature rising rate: 5 ° C./min Dynamic viscoelasticity was measured and adopted as the temperature Tg of tan δ peak top.

Further, the active energy ray-curable adhesive composition is preferably designed so that the storage elastic modulus of the adhesive layer formed thereby is 1.0 × 10 ⁶ Pa or higher in the region of 70 ° C. or lower. . Further, it is more preferably 1.0 × 10 ⁷ Pa or more. The storage elastic modulus of the adhesive layer affects the polarizer cracks when the polarizing film is subjected to a heat cycle (from −40 ° C. to 80 ° C., etc.). If the storage elastic modulus is low, defects of the polarizer cracks occur. Cheap. The temperature region having a high storage elastic modulus is more preferably 80 ° C. or less, and most preferably 90 ° C. or less. The storage elastic modulus is measured under the same measurement conditions using a dynamic viscoelasticity measuring device RSAIII manufactured by TA Instruments simultaneously with Tg (glass transition temperature). The dynamic viscoelasticity was measured and the storage elastic modulus (E ′) value was adopted.

  In the method for producing a laminated optical film according to the present invention, at least a first optical film and a second optical film are laminated via an adhesive layer formed by curing an active energy ray-curable adhesive composition. A method for producing a laminated optical film, wherein the active energy ray-curable adhesive composition includes a first active energy ray-curable adhesive composition and a second active energy ray-curable adhesive composition. It contains different active energy ray-curable adhesive compositions of different types, and the first active energy ray-curable adhesive composition is applied to the bonding surface of the first optical film, and the first A coating step of coating the second active energy ray-curable adhesive composition on the bonding surface of the two optical films, the first optical film, and the second optical film; The bonding step, and the active energy ray-curable adhesive composition formed by irradiating active energy rays from the first optical film surface side or the second optical film surface side and curing the active energy ray-curable adhesive composition. A bonding step of bonding the first optical film and the second optical film through an adhesive layer.

In another method for producing a laminated optical film according to the present invention, at least a first optical film and a second optical film are laminated via an adhesive layer formed by curing an active energy ray-curable adhesive composition. A method for producing a laminated optical film, wherein the active energy ray-curable adhesive composition includes a first active energy ray-curable adhesive composition and a second active energy ray-curable adhesive composition, Containing at least two different active energy ray-curable adhesive compositions, applying the first active energy ray-curable adhesive composition to the bonding surface of the first optical film, A coating step of further overcoating the second active energy ray-curable adhesive composition on the coating surface coated with the first active energy ray-curable adhesive composition; A laminating step of laminating the second optical film from the coated surface side of the second active energy ray-curable adhesive composition coated on the film, and laminating the first optical film and the second optical film The bonding process formed by irradiating active energy rays from the first optical film surface side or the second optical film surface side and curing the active energy ray-curable adhesive composition An adhesion step of adhering the first optical film and the second optical film through an agent layer.

  In the method for producing a laminated optical film according to the present invention, when the laminated optical film is a polarizing film, the polarizer and the transparent protective film are subjected to surface modification before the application of the active energy ray-curable adhesive composition. Quality processing may be performed. Specific examples of the treatment include corona treatment, plasma treatment, and saponification treatment.

  The coating method of the active energy ray-curable adhesive 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.

  Two different optical films, for example, a polarizer and a transparent protective film are bonded together through the active energy ray-curable adhesive composition applied as described above. Bonding of the polarizer and the transparent protective film can be performed with a roll laminator or the like.

<Curing the adhesive>
The active energy ray curable adhesive composition used in the present invention can be used in an electron beam curable type, an ultraviolet curable type, or a visible light curable type. As the active energy ray curable adhesive composition, a visible light curable adhesive composition is preferable from the viewpoint of productivity.

  In the active energy ray curable adhesive composition, for example, after bonding a polarizer and a transparent protective film, the active energy ray (electron beam, ultraviolet ray, visible light, etc.) is irradiated to obtain an active energy ray curable adhesive composition. The object is cured to form an adhesive layer. The irradiation direction of active energy rays (electron beam, ultraviolet ray, visible light, 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 beam, ultraviolet ray, visible light, etc.).

  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 adhesive 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.

  In the method for producing a laminated optical film according to the present invention, in particular, the method for producing a polarizing film, the active energy ray contains visible light having a wavelength range of 380 nm to 450 nm, particularly the irradiation amount of visible light having a wavelength range of 380 nm to 450 nm. It is preferable to use the active energy ray having the largest number. In the case of using a transparent protective film (ultraviolet non-transparent transparent protective film) imparted with ultraviolet absorbing ability in the ultraviolet curable type and visible light curable type, light having a wavelength shorter than about 380 nm is absorbed. Light does not reach the active energy ray-curable adhesive and does not contribute to the polymerization reaction. Furthermore, light having a wavelength shorter than 380 nm absorbed by the transparent protective film is converted into heat, and the transparent protective film itself generates heat, which causes defects such as curling and wrinkling of the polarizing film. Therefore, when the ultraviolet curable type or the visible light curable type is adopted in the present invention, it is preferable to use a device that does not emit light having a wavelength shorter than 380 nm as the active energy ray generating device, and more specifically, the wavelength range 380. The ratio of the integrated illuminance of ˜440 nm to the integrated illuminance of the wavelength range 250 to 370 nm is preferably 100: 0 to 100: 50, and more preferably 100: 0 to 100: 40. As the active energy ray according to the present invention, a gallium-encapsulated metal halide lamp and an LED light source that emits light in the wavelength range of 380 to 440 nm are preferable. Or 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 A light source including visible light can be used, and ultraviolet light having a wavelength shorter than 380 nm can be blocked using a band pass filter. In order to prevent the polarization film from curling while improving the adhesive performance of the adhesive layer between the polarizer and the transparent protective film, a gallium-encapsulated metal halide lamp can be used and light with a wavelength shorter than 380 nm can be blocked. It is preferable to use an active energy ray obtained through a band pass filter or an active energy ray having a wavelength of 405 nm obtained using an LED light source.

  In the ultraviolet curable type or visible light curable type, it is also preferable to heat the active energy ray curable adhesive after irradiation with ultraviolet rays or visible light (heating after irradiation), and in this case, it is preferable to heat to 40 ° C. or higher. It is more preferable to heat to 50 ° C. or higher.

  The active energy ray-curable adhesive used in the present invention can be suitably used particularly for forming an adhesive layer for bonding a polarizer and a transparent protective film having a light transmittance of a wavelength of 365 nm of less than 5%. is there. Here, the active energy ray-curable adhesive according to the present invention irradiates ultraviolet rays through the transparent protective film having UV absorption ability by containing the photopolymerization initiator of the general formula (1) described above, The adhesive layer can be hardened. Therefore, an adhesive bond layer can be hardened also in a polarizing film which laminated a transparent protective film which has UV absorption ability on both sides of a polarizer. However, as a matter of course, the adhesive layer can also be cured in a polarizing film in which a transparent protective film having no UV absorbing ability is laminated. In addition, the transparent protective film which has UV absorption ability means the transparent protective film whose transmittance | permeability with respect to light of 380 nm is less than 10%.

  Examples of the method for imparting UV absorbing ability to the transparent protective film include a method of containing an ultraviolet absorber in the transparent protective film and a method of laminating a surface treatment layer containing an ultraviolet absorber on the surface of the transparent protective film.

  Specific examples of the ultraviolet absorber include conventionally known oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, triazine compounds, and the like. .

After bonding two different optical films, for example, a polarizer and a transparent protective film, an active energy ray (electron beam, ultraviolet ray, visible light, etc.) is irradiated to cure the active energy ray-curable adhesive, and the adhesive Form a layer. The moisture content of the polarizer when the polarizer and the transparent protective film are bonded together is usually 1% or more, preferably 3% or more, more preferably 5% or more. In addition, when the moisture content of the polarizer is too high, the moisture in the polarizer moves to the adhesive layer after bonding, and the B component having a log POW of 2 to 7 in the adhesive composition is separated into layers, resulting in poor appearance. This is not preferable. The moisture content of the polarizer is preferably 18% or less, more preferably 15% or less, and most preferably 12% or less. For the polarizer moisture content, a sample of 180 mm × 500 mm was cut out from the obtained polarizer, and its initial weight (W (g)) was measured. The sample was allowed to stand in a dryer at 120 ° C. for 6 hours, and then the weight after drying (D (g)) was measured. From these measured values, the moisture content was determined by the following formula.
Moisture content (%) = {(WD) / W} × 100
The irradiation direction of active energy rays (electron beam, ultraviolet ray, visible light, 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 beam, ultraviolet ray, visible light, etc.).

When the laminated optical film 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 further preferably 10 to 100 m. / Min. When the line speed is too low, the productivity is poor, or the damage to the transparent protective film is too great, and a polarizing film that can withstand the durability test 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 method for producing a laminated optical film according to the present invention, when the laminated optical film is a polarizing film, the polarizer and the transparent protective film are bonded with a cured product layer of the active energy ray-curable adhesive. Although it bonds through an agent layer, an easily bonding layer can be provided between a transparent protective film and an adhesive bond layer. 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.

<Polarizer>
The production method according to the present invention is particularly useful as a production method of a polarizing film. The polarizer used in producing the polarizing film 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 80 μm or less.

  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.

  The active energy ray-curable adhesive composition used in the present invention has an effect (optical durability in harsh environments under high temperature and high humidity) when a thin polarizer having a thickness of 10 μm or less is used as the polarizer. Can be remarkably expressed). The polarizer having a thickness of 10 μm or less is relatively more affected by moisture than a polarizer having a thickness exceeding 10 μm, and has insufficient optical durability in a high-temperature and high-humidity environment, resulting in increased transmittance and degree of polarization. Decline is likely to occur. That is, when the polarizer of 10 μm or less is laminated with the adhesive layer having a bulk water absorption of 10% by weight or less according to the present invention, the movement of water to the polarizer is suppressed in a severe high temperature and high humidity environment. Thus, deterioration of optical durability such as an increase in transmittance of the polarizing film and a decrease in the degree of polarization can be remarkably suppressed. The thickness of the polarizer is preferably 1 to 7 μm from the viewpoint of thinning. Such a thin polarizer is preferable in that the thickness unevenness is small, the visibility is excellent, the dimensional change is small, and the thickness of the polarizing film can be reduced.

  As the thin polarizer, representatively, JP-A-51-069644, JP-A-2000-338329, WO2010 / 100917 pamphlet, PCT / JP2010 / 001460 specification, or Japanese Patent Application 2010- The thin polarizing film described in 269002 specification and Japanese Patent Application No. 2010-263692 specification can be mentioned. These thin polarizing films can be obtained by a production method including a step of stretching a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a stretching resin base material in a laminated state and a step of dyeing. With this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching by being supported by the stretching resin substrate.

  As the thin polarizing film, among the production methods including the step of stretching in the state of a laminate and the step of dyeing, WO2010 / 100917 pamphlet, PCT / PCT / PCT / JP 2010/001460 specification, or Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692 as described in the manufacturing method including a step of stretching in a boric acid aqueous solution is preferable. What is obtained by the manufacturing method including the process of extending | stretching in the air auxiliary | assistant before extending | stretching in the boric acid aqueous solution as described in Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692 is preferable.

  The thin high-performance polarizing film described in the specification of PCT / JP2010 / 001460 is a thin film having a thickness of 7 μm or less made of a PVA-based resin oriented with a dichroic material, which is integrally formed on a resin base material. It is a high-functional polarizing film, and has optical properties such as a single transmittance of 42.0% or more and a degree of polarization of 99.95% or more.

  The thin high-performance polarizing film generates a PVA-based resin layer by applying and drying a PVA-based resin on a resin substrate having a thickness of at least 20 μm, and the generated PVA-based resin layer is used as a dichroic dyeing solution. So that the dichroic substance is adsorbed on the PVA resin layer, and the PVA resin layer on which the dichroic substance is adsorbed is integrated with the resin base material in the boric acid aqueous solution so that the total draw ratio is the original length. It can manufacture by extending | stretching so that it may become 5 times or more.

  Moreover, it is a method for producing a laminate film including a thin high-performance polarizing film in which a dichroic substance is oriented, and includes a resin base material having a thickness of at least 20 μm and a PVA resin on one side of the resin base material. The said laminated body containing the process of producing | generating the laminated body film containing the PVA-type resin layer formed by apply | coating and drying aqueous solution, and the PVA-type resin layer formed in the single side | surface of the resin base material A step of adsorbing the dichroic substance to the PVA resin layer contained in the laminate film by immersing the film in a dye solution containing the dichroic substance, and a PVA resin adsorbing the dichroic substance A step of stretching the laminate film including a layer in a boric acid aqueous solution so that the total stretching ratio is 5 times or more of the original length, and a PVA resin layer on which a dichroic substance is adsorbed Stretched together with As a result, a thickness of 7 μm or less, a single transmittance of 42.0% or more, and a degree of polarization of 99.95% or more are formed of a PVA resin layer in which a dichroic material is oriented on one side of a resin base The thin high-performance polarizing film can be manufactured by including a step of manufacturing a laminate film on which a thin high-performance polarizing film having the above optical characteristics is formed.

The thin polarizing film in the above-mentioned Japanese Patent Application Nos. 2010-269002 and 2010-263692 is a continuous web polarizing film made of a PVA resin in which a dichroic material is oriented, and is amorphous. The laminate including the PVA-based resin layer formed on the ester-based thermoplastic resin base material was stretched in a two-stage stretching process consisting of air-assisted stretching and boric acid-water stretching, so that the thickness was 10 μm or less. Is. Such a thin polarizing film has P> − (10 ^{0.929T-42.4-1} ) × 100 (where T <42.3) and P ≧ when the single transmittance is T and the polarization degree is P. It is preferable that the optical properties satisfy 99.9 (where T ≧ 42.3).

  Specifically, the thin polarizing film is a stretch intermediate formed of an oriented PVA resin layer by high-temperature stretching in the air with respect to the PVA resin layer formed on the amorphous ester thermoplastic resin substrate of the continuous web. A colored intermediate product comprising a PVA-based resin layer in which a dichroic material (preferably iodine or a mixture of iodine and an organic dye) is oriented by adsorption of the dichroic material to the stretched intermediate product and a step of generating the product. A thin polarizing film comprising a step of forming a product, and a step of generating a polarizing film having a thickness of 10 μm or less comprising a PVA-based resin layer in which a dichroic material is oriented by stretching in a boric acid solution with respect to a colored intermediate product It can be manufactured by a manufacturing method.

  In this production method, the total draw ratio of the PVA resin layer formed on the amorphous ester thermoplastic resin base material by high-temperature drawing in air and drawing in boric acid solution should be 5 times or more. desirable. The liquid temperature of the boric acid aqueous solution for boric-acid water extending | stretching can be 60 degreeC or more. Before stretching the colored intermediate product in the aqueous boric acid solution, it is desirable to insolubilize the colored intermediate product. In this case, the colored intermediate product is added to the aqueous boric acid solution whose liquid temperature does not exceed 40 ° C. It is desirable to do so by dipping. The amorphous ester-based thermoplastic resin base material is amorphous polyethylene containing copolymerized polyethylene terephthalate copolymerized with isophthalic acid, copolymerized polyethylene terephthalate copolymerized with cyclohexanedimethanol, or other copolymerized polyethylene terephthalate. It can be terephthalate and is preferably made of a transparent resin, and the thickness thereof can be 7 times or more the thickness of the PVA resin layer to be formed. Moreover, the draw ratio of the high temperature stretching in the air is preferably 3.5 times or less, and the stretching temperature of the high temperature stretching in the air is preferably not less than the glass transition temperature of the PVA resin, specifically in the range of 95 ° C to 150 ° C. When performing high temperature stretching in the air by free end uniaxial stretching, the total stretching ratio of the PVA resin layer formed on the amorphous ester thermoplastic resin base material is preferably 5 to 7.5 times . In addition, when performing high-temperature stretching in the air by uniaxial stretching at the fixed end, the total stretching ratio of the PVA-based resin layer formed on the amorphous ester-based thermoplastic resin base material is 5 times or more and 8.5 times or less. Is preferred.

  More specifically, a thin polarizing film can be produced by the following method.

  A base material of a continuous web of isophthalic acid copolymerized polyethylene terephthalate (amorphous PET) in which 6 mol% of isophthalic acid is copolymerized is prepared. The glass transition temperature of amorphous PET is 75 ° C. A laminate comprising a continuous web of amorphous PET substrate and a polyvinyl alcohol (PVA) layer is prepared as follows. Incidentally, the glass transition temperature of PVA is 80 ° C.

  A 200 μm-thick amorphous PET base material and a 4-5% concentration PVA aqueous solution in which PVA powder having a polymerization degree of 1000 or more and a saponification degree of 99% or more are dissolved in water are prepared. Next, a PVA aqueous solution is applied to a 200 μm thick amorphous PET substrate and dried at a temperature of 50 to 60 ° C. to obtain a laminate in which a 7 μm thick PVA layer is formed on the amorphous PET substrate. .

  A laminated body including a PVA layer having a thickness of 7 μm is subjected to the following steps including a two-step stretching process of air-assisted stretching and boric acid water stretching to produce a thin high-functional polarizing film having a thickness of 3 μm. In the first-stage aerial auxiliary stretching step, the laminate including the 7 μm-thick PVA layer is integrally stretched with the amorphous PET substrate to produce a stretched laminate including the 5 μm-thick PVA layer. Specifically, in this stretched laminate, a laminate including a 7 μm-thick PVA layer is subjected to a stretching apparatus disposed in an oven set to a stretching temperature environment of 130 ° C. so that the stretching ratio is 1.8 times. Are stretched uniaxially at the free end. By this stretching treatment, the PVA layer contained in the stretched laminate is changed to a 5 μm thick PVA layer in which PVA molecules are oriented.

  Next, a colored laminate in which iodine is adsorbed on a PVA layer having a thickness of 5 μm in which PVA molecules are oriented is generated by a dyeing process. Specifically, this colored laminate has a single layer transmittance of the PVA layer constituting the high-functional polarizing film that is finally produced by using the stretched laminate in a staining solution containing iodine and potassium iodide at a liquid temperature of 30 ° C. Iodine is adsorbed to the PVA layer contained in the stretched laminate by dipping for an arbitrary period of time so as to be 40 to 44%. In this step, the staining solution uses water as a solvent and an iodine concentration in the range of 0.12 to 0.30% by weight and a potassium iodide concentration in the range of 0.7 to 2.1% by weight. The concentration ratio of iodine and potassium iodide is 1 to 7. Incidentally, potassium iodide is required to dissolve iodine in water. More specifically, by immersing the stretched laminate in a dyeing solution having an iodine concentration of 0.30% by weight and a potassium iodide concentration of 2.1% by weight for 60 seconds, iodine is applied to a 5 μm-thick PVA layer in which PVA molecules are oriented. A colored laminate is adsorbed on the substrate.

  Further, the colored laminated body is further stretched integrally with the amorphous PET base material by the second stage boric acid underwater stretching step to produce an optical film laminate including a PVA layer constituting a highly functional polarizing film having a thickness of 3 μm. To do. Specifically, this optical film laminate is stretched by applying a colored laminate to a stretching apparatus provided in a treatment apparatus set to a boric acid aqueous solution having a liquid temperature range of 60 to 85 ° C. containing boric acid and potassium iodide. It is stretched uniaxially at the free end so that the magnification is 3.3 times. More specifically, the liquid temperature of the boric acid aqueous solution is 65 ° C. It also has a boric acid content of 4 parts by weight with respect to 100 parts by weight of water and a potassium iodide content of 5 parts by weight with respect to 100 parts by weight of water. In this step, the colored laminate with adjusted iodine adsorption amount is first immersed in a boric acid aqueous solution for 5 to 10 seconds. After that, the colored laminate is passed as it is between a plurality of sets of rolls having different peripheral speeds, which is a stretching apparatus provided in the processing apparatus, and the stretching ratio is freely increased to 3.3 times over 30 to 90 seconds. Stretch uniaxially. By this stretching treatment, the PVA layer contained in the colored laminate is changed into a PVA layer having a thickness of 3 μm in which the adsorbed iodine is oriented higher in one direction as a polyiodine ion complex. This PVA layer constitutes a highly functional polarizing film of the optical film laminate.

  Although not an indispensable step for the production of an optical film laminate, the optical film laminate was removed from the boric acid aqueous solution and adhered to the surface of the 3 μm-thick PVA layer formed on the amorphous PET substrate by the washing step. It is preferable to wash boric acid with an aqueous potassium iodide solution. Thereafter, the washed optical film laminate is dried by a drying process using hot air at 60 ° C. The cleaning process is a process for eliminating appearance defects such as boric acid precipitation.

Similarly, it is not an indispensable process for producing an optical film laminate, but an adhesive is applied to the surface of a 3 μm-thick PVA layer formed on an amorphous PET substrate by a bonding and / or transfer process. However, after bonding the 80 μm thick triacetyl cellulose film, the amorphous PET substrate can be peeled off, and the 3 μm thick PVA layer can be transferred to the 80 μm thick triacetyl cellulose film.
[Other processes]
The manufacturing method of said thin-shaped polarizing film may include another process other than the said process. Examples of other steps include an insolubilization step, a crosslinking step, and a drying (adjustment of moisture content) step. The other steps can be performed at any appropriate timing.

  The insolubilization step is typically performed by immersing the PVA resin layer in a boric acid aqueous solution. By performing the insolubilization treatment, water resistance can be imparted to the PVA resin layer. The concentration of the boric acid aqueous solution is preferably 1 to 4 parts by weight with respect to 100 parts by weight of water. The liquid temperature of the insolubilizing bath (boric acid aqueous solution) is preferably 20 ° C to 50 ° C. Preferably, the insolubilization step is performed after the laminate is manufactured and before the dyeing step and the underwater stretching step.

  The crosslinking step is typically performed by immersing the PVA resin layer in an aqueous boric acid solution. By performing the crosslinking treatment, water resistance can be imparted to the PVA resin layer. The concentration of the boric acid aqueous solution is preferably 1 to 4 parts by weight with respect to 100 parts by weight of water. Moreover, when performing a bridge | crosslinking process after the said dyeing | staining process, it is preferable to mix | blend iodide further. By blending iodide, elution of iodine adsorbed on the PVA resin layer can be suppressed. The blending amount of iodide is preferably 1 part by weight to 5 parts by weight with respect to 100 parts by weight of water. Specific examples of the iodide are as described above. The liquid temperature of the crosslinking bath (boric acid aqueous solution) is preferably 20 ° C to 50 ° C. Preferably, the crosslinking step is performed before the second boric acid aqueous drawing step. In a preferred embodiment, the dyeing step, the crosslinking step, and the second boric acid aqueous drawing step are performed in this order.

<Transparent protective film>
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 weight, more preferably 50 to 99% by weight, still more preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. . When content of the said thermoplastic resin in a transparent protective film is 50 weight% or less, there exists a possibility that the high transparency etc. which a thermoplastic resin originally has cannot fully be expressed.

  Further, as the transparent protective film, a polymer film described in JP-A-2001-343529 (WO01 / 37007), for example, (A) a thermoplastic resin having a substituted and / or unsubstituted imide group in the side chain, and a side Examples thereof include a resin composition containing a thermoplastic resin having a substituted and / or unsubstituted phenyl and nitrile group in the 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 film can be eliminated, and since the moisture permeability is small, the humidification durability is excellent.

In the polarizing film, it is preferable moisture permeability of the transparent protective film is not more than 150g ^/ m 2 ^/ 24h. According to such a configuration, it is difficult for moisture in the air to enter the polarizing film, and a change in the moisture content of the polarizing film itself can be suppressed. As a result, the curling and dimensional change of the polarizing film caused by the storage environment can be suppressed.

As a material for forming a transparent protective film provided on one or both sides of the polarizer, a material excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, and the like is preferable. / ^m, more preferably not more 2 / 24h or less, particularly preferably those following 140 g ^/ m 2 / 24h, more preferably the following 120 g ^/ m 2 / 24h. The moisture permeability is determined by the method described in the examples.

  Examples of the material for forming the transparent protective film satisfying the low moisture permeability include polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate resins; arylate resins; amide resins such as nylon and aromatic polyamide; polyethylene, polypropylene Polyolefin polymers such as ethylene / propylene copolymers, cyclic olefin resins having a cyclo or norbornene structure, (meth) acrylic resins, or a mixture thereof can be used. Among the resins, polycarbonate resins, cyclic polyolefin resins, and (meth) acrylic resins are preferable, and cyclic polyolefin resins and (meth) acrylic resins are particularly preferable.

  Although the thickness of a transparent protective film can be determined suitably, generally it is about 1-100 micrometers from points, such as workability | operativity, such as intensity | strength and a handleability, and thin-layer property. 1-80 micrometers is especially preferable, and 3-60 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. The combination of the transparent protective film includes a combination of a polyethylene terephthalate film and a cyclic polyolefin resin film, a (meth) acrylic resin film and a cyclic polyolefin resin film, a (meth) acrylic resin film and a (meth) acrylic resin film. It is preferable from the viewpoint of moisture permeability. By providing a transparent protective film with low moisture permeability on both surfaces of the polarizer, it is difficult for moisture to enter the polarizing film, and a polarizing film having particularly excellent water resistance can be obtained.

  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.

<Optical film>
The polarizing film 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 film or semi-transmissive polarizing film in which a polarizing plate or a semi-transmissive reflecting plate is further laminated on the polarizing film of the present invention, an elliptical polarizing film or circularly polarizing film in which a retardation film is further laminated on a polarizing film. A wide viewing angle polarizing film obtained by further laminating a viewing angle compensation film on a film or a polarizing film, or a polarizing film obtained by further laminating a brightness enhancement film on the polarizing film is preferred.

  An optical film obtained by laminating the above optical layer on a polarizing film can be formed by a method of sequentially 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 film 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 film described above or an optical film in which at least one polarizing film 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 film or an optical film as an overlapping layer of different compositions or types. Moreover, when providing in both surfaces, it can also be set as adhesive layers, such as a different composition, a kind, and thickness, in the front and back of a polarizing film 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, an appropriate thin leaf body such as a plastic film, rubber sheet, paper, cloth, non-woven fabric, net, foamed sheet, metal foil, or a laminate thereof, or a silicone-based or long sheet as necessary. Appropriate ones according to the prior art, such as those coated with an appropriate release agent such as a chain alkyl type, fluorine type or molybdenum sulfide, can be used.

<Image display device>
The polarizing film 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 film 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 film 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 film or an optical film is disposed on one side or both sides of a liquid crystal cell, or a backlight or a reflecting plate that is used in an illumination system can be formed. In that case, the polarizing film 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 film or an optical film on both sides, they may be the same or different. Further, when forming the liquid crystal display device, for example, a single layer or a suitable layer 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.

Production Example 1
<Preparation of polyvinyl alcohol thin polarizer (corresponding to the first optical film)>
In order to produce a thin polarizer, first, a laminate in which a PVA layer having a thickness of 24 μm is formed on an amorphous PET base material is produced by air-assisted stretching at a stretching temperature of 130 ° C., and then stretched. A colored laminate is produced by dyeing the laminate, and the colored laminate is further stretched integrally with an amorphous PET substrate so that the total draw ratio is 5.94 times by stretching in boric acid water at a stretching temperature of 65 degrees. An optical film laminate including a 10 μm thick PVA layer was produced. The PVA molecules in the PVA layer formed on the amorphous PET substrate by such two-stage stretching are oriented in the higher order, and the iodine adsorbed by the dyeing is oriented in the one direction as the polyiodine ion complex. It was possible to produce an optical film laminate including a PVA layer having a thickness of 10 μm constituting a thin polyvinyl alcohol-based thin polarizer.

Production Example 2
<Preparation of transparent protective film (corresponding to the second optical film)>
A biaxial kneader containing 100 parts by weight of imidized MS resin and 0.62 part by weight of a triazine-based ultraviolet absorber (trade name: T-712, manufactured by Adeka Co.) described in Production Example 1 of JP 2010-284840 A Was mixed at 220 ° C. to prepare resin pellets. The obtained resin pellets were dried at 100.5 kPa and 100 ° C. for 12 hours, extruded from a T-die at a die temperature of 270 ° C. with a single screw extruder, and formed into a film (thickness: 160 μm). Further, the film is stretched in the conveyance direction in a 150 ° C. atmosphere (thickness 80 μm), and after applying an easy-adhesive containing an aqueous urethane resin, the film is stretched in a direction perpendicular to the film conveyance direction in a 150 ° C. atmosphere. and to obtain an acrylic film having a thickness of 40 [mu] m (moisture permeability ^58g / m 2 / 24h) (transparent protective film).

<Water vapor permeability of transparent protective film>
The moisture permeability was measured according to a moisture permeability test (cup method) of JIS Z0208. A sample cut to a diameter of 60 mm was set in a moisture permeable cup containing about 15 g of calcium chloride, and the temperature was 40 ° C. and the humidity was 90% R.D. H. The placed in a constant temperature machine, to determine the moisture permeability by measuring the weight increase of calcium chloride before and after allowing to stand for 24 hours ^{(g / m 2 / 24h)} .

<Active energy rays>
Visible light (gallium filled metal halide lamp) as an active energy ray 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 380) 440 nm) was used. The illuminance of visible light was measured using a Sola-Check system manufactured by Solatell.

Example 1
An active energy ray-curable adhesive composition containing the following compounds was prepared.
1st active energy ray hardening-type adhesive composition (liquid viscosity 350mPa * s / 25 degreeC); HEAA 94 weight%, IRGACURE907 3 weight%, KAYACURE DETX-S 3 weight%
Second active energy ray-curable adhesive composition (liquid viscosity: 10 mPa · s / 25 ° C.); light acrylate 1,9ND-A 94% by weight, IRGACURE907 3% by weight, KAYACURE DETX-S 3% by weight

The compound used was
HEAA: hydroxyethylacrylamide, logPow = −0.56, manufactured by Kojin Co., Ltd.
Light acrylate 1,9ND-A: 1,9-nonanediol diacrylate, logPow = 3.68, manufactured by Kyoeisha Chemical Co., Ltd.
IRGACURE907; 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, manufactured by BASF Corporation
KAYACURE DETX-S; diethylthioxanthone, manufactured by Nippon Kayaku Co., Ltd.

(Preparation of polarizing film)
The thin active polarizer corresponding to the first optical film was coated on the PVA layer surface with the first active energy ray-curable adhesive composition heated to 40 ° C. and adjusted to a liquid viscosity of 80 cp (adhesive layer thickness). 0.3 μm). Moreover, the 2nd active energy ray hardening-type adhesive composition is applied to the bonding surface of the transparent protective film applicable to a 2nd optical film (adhesive layer thickness 0.7 micrometer), and these are stuck with a roll machine. Combined. The ratio of the first active energy ray-curable adhesive composition to the second active energy ray-curable adhesive composition is 30:70. Thereafter, the first and second active energy ray-curable adhesive compositions are cured by irradiating both sides with the visible light, and then dried with hot air at 70 ° C. for 3 minutes to form transparent protective films on both sides of the polarizer. A polarizing film (laminated optical film) was obtained. The line speed of bonding was 25 m / min.

  About the polarizing film obtained in the said Example 1, the adhesive force with respect to a thin polarizer and a transparent protective film was evaluated. Moreover, the contact angle of the 1st active energy ray hardening-type adhesive composition with respect to a thin polarizer and the contact angle of the 2nd active energy ray hardening-type adhesive composition with respect to a transparent protective film were evaluated. The contact angle was evaluated based on JIS-K 6768. The evaluation results are shown in Table 2.

Example 2
Instead of the coating step of applying the second active energy ray-curable adhesive composition to the bonding surface of the transparent protective film corresponding to the second optical film, bonding of the thin polarizer corresponding to the first optical film Example 1 except that a coating process in which a second active energy ray-curable adhesive composition was further overcoated on the surface coated with the first active energy ray-curable adhesive composition on the surface was carried out. A polarizing film (laminated optical film) having a transparent protective film on both sides of the polarizer was obtained by the same method.

Comparative Example 1
The first activity containing 47% by weight of HEAA, 47% by weight of light acrylate 1,9ND-A, 3% by weight of IRGACURE907, 3% by weight of KAYACURE DETX-S on the bonding surface of the thin polarizer corresponding to the first optical film The same method as in Example 1 except that an energy ray curable adhesive composition (liquid viscosity: 21 mPa · s / 25 ° C.) was applied and a transparent protective film corresponding to the second optical film was bonded thereto. Thus, a polarizing film (laminated optical film) having a transparent protective film on both sides of the polarizer was obtained.

  The following evaluation was performed about the polarizing film obtained by the said Example and comparative example. The evaluation results are shown in Table 2.

<Adhesive strength>
The polarizing film obtained in each example was cut out to a size of 200 mm parallel to the stretching direction of the polarizer and 20 mm in the perpendicular direction, and a slit was cut between the transparent protective film and the polarizer with a cutter knife. Laminated to the board. Using Tensilon, the transparent protective film and the polarizer were peeled in the 90-degree direction at a peeling speed of 500 mm / min, and the peel strength was measured. Moreover, the infrared absorption spectrum of the peeling surface after peeling was measured by ATR method, and the peeling interface was evaluated based on the following reference | standard.
A: Cohesive failure of transparent protective film B: Interfacial peeling between transparent protective film / adhesive layer C: Interfacial peeling between adhesive layer / polarizer D: Cohesive failure of polarizer In the above criteria, A and D are adhesive strengths Is greater than the cohesive strength of the film, which means that the adhesive strength is very excellent. On the other hand, B and C mean that the adhesive force at the transparent protective film / adhesive layer (adhesive layer / polarizer) interface is insufficient (adhesive strength is poor). Taking these into consideration, the adhesive strength in the case of A or D is ○, A · B ("cohesive failure of transparent protective film" and "interfacial peeling between transparent protective film / adhesive layer" occur simultaneously) or A -Adhesive strength in the case of C ("cohesive failure of transparent protective film" and "interfacial peeling between adhesive layer / polarizer" occur simultaneously) Δ, adhesive strength in the case of B or C as x To do.

Claims (9)

A method for producing a laminated optical film in which at least a first optical film and a second optical film are laminated via an adhesive layer formed by curing an active energy ray-curable adhesive composition,
One of the first optical film and the second optical film is a polyvinyl alcohol polarizer,
The active energy ray curable adhesive composition includes at least two different active energy ray curable adhesives, including a first active energy ray curable adhesive composition and a second active energy ray curable adhesive composition. Containing an agent composition,
The first active energy ray-curable adhesive composition is applied to the bonding surface of the first optical film, and the second active energy ray-curable adhesive composition is further applied to the bonding surface of the second optical film. Coating process for coating,
A bonding step of bonding the first optical film and the second optical film;
Through the adhesive layer formed by irradiating active energy rays from the first optical film surface side or the second optical film surface side and curing the active energy ray-curable adhesive composition, The manufacturing method of the laminated optical film characterized by including the adhesion process to adhere | attach the said 1st optical film and the said 2nd optical film. A method for producing a laminated optical film in which at least a first optical film and a second optical film are laminated via an adhesive layer formed by curing an active energy ray-curable adhesive composition,
The active energy ray curable adhesive composition includes at least two different active energy ray curable adhesives, including a first active energy ray curable adhesive composition and a second active energy ray curable adhesive composition. Containing an agent composition,
The first active energy ray-curable adhesive composition is applied to the bonding surface of the first optical film, and the first active energy ray-curable adhesive composition is further applied to the coated surface. A coating step of overcoating the two active energy ray-curable adhesive composition;
A bonding step of bonding the second optical film from the coated surface side of the second active energy ray-curable adhesive composition coated on the first optical film;
Through the adhesive layer formed by irradiating active energy rays from the first optical film surface side or the second optical film surface side and curing the active energy ray-curable adhesive composition, The manufacturing method of the laminated optical film characterized by including the adhesion process to adhere | attach the said 1st optical film and the said 2nd optical film.   The method for producing a laminated optical film according to claim 2, wherein the liquid viscosity of the first active energy ray-curable adhesive composition is higher than the liquid viscosity of the second active energy ray-curable adhesive composition.   The method for producing a laminated optical film according to any one of claims 1 to 3, wherein a contact angle of the active energy ray-curable adhesive composition with respect to the first optical film and the second optical film is 5 to 50 degrees. . The said 1st optical film is the said polyvinyl alcohol type polarizer, The said 1st active energy ray hardening-type adhesive composition contains the radically polymerizable compound whose logPow is -1 to 1, Any of Claims 1-4. A method for producing a laminated optical film according to claim 1. Any pre-Symbol second optical film, wherein the acrylic resin film, wherein the cycloolefin resin film, wherein at least one of the optical film is selected from polyester resin film and the group consisting of the polyolefin resin film according to claim 1 to 5 A method for producing a laminated optical film according to claim 1. The acrylic resin film, the cycloolefin resin film, the polyester resin film, and the polyolefin resin film are selected from the group consisting of acrylic resin, polyurethane resin, polyvinyl alcohol resin, melamine resin, and oxazoline group-containing resin on the bonding surface. The method for producing a laminated optical film according to claim 6 , wherein an easy adhesion layer containing at least one kind of resin is formed. The method for producing a laminated optical film according to claim 6 or 7, wherein the second active energy ray-curable adhesive composition contains a radical polymerizable compound having a log Pow of 2 to 7 . Laminate according to the active energy ray-curable adhesive composition is coated on bonded mating surface of the front Symbol polyvinyl alcohol polarizer claim 1 containing a hydroxyl group-containing radical polymerizable compound Manufacturing method of optical film.