JP7027003B2 - Laminated optical film and its manufacturing method, and image display device - Google Patents

Description

The present invention relates to a laminated optical film in which a transparent protective film is laminated on at least one surface of the optical film via an adhesive layer formed by curing the adhesive composition, and a method for producing the same. The laminated optical film can form an image display device such as a liquid crystal display (LCD), an organic EL display device, a CRT, or a PDP.

Liquid crystal display devices are rapidly expanding into the market for watches, mobile phones, PDA, notebook computers, personal computer monitors, DVD players, TVs, and the like. The liquid crystal display device visualizes the polarization state due to the switching of the liquid crystal, and a polarizing element is used because of the display principle thereof. In particular, in applications such as TVs, higher brightness, higher contrast, and wider viewing angle are required, and even in polarizing films, higher transmittance, higher degree of polarization, and higher color reproducibility are required.

As the polarizing element, since it has high transmittance and high degree of polarization, for example, an iodine-based polarizing element having a stretched structure in which iodine is adsorbed on polyvinyl alcohol (hereinafter, also simply referred to as “PVA”) is the most widely used. It is used. Generally, as the polarizing film, a film in which a transparent protective film is bonded to both sides of a polarizing element by a so-called water-based adhesive obtained by dissolving a polyvinyl alcohol-based material in water is used (Patent Document 1 below). As the transparent protective film, triacetyl cellulose having high moisture permeability is used. When the water-based adhesive is used (so-called wet lamination), a drying step is required after the polarizing element and the transparent protective film are bonded together.

On the other hand, instead of the water-based adhesive, an active energy ray-curable adhesive composition has been proposed. When the polarizing film is produced using the active energy ray-curable adhesive composition, the productivity of the polarizing film can be improved because the drying step is not required. For example, the present inventors have proposed a radical polymerization type active energy ray-curable adhesive composition using an N-substituted amide-based monomer as a curable component (Patent Document 2 below).

Japanese Unexamined Patent Publication No. 2001-296427 Japanese Unexamined Patent Publication No. 2012-052000

The adhesive layer formed by using the active energy ray-curable adhesive composition described in Patent Document 2 has excellent adhesiveness, but in the market, it is in a poor environment with respect to an optical film, for example, under harsh humidification conditions. However, it may be required to have excellent adhesiveness. For example, the active energy ray-curable adhesive composition is superior to the water-based adhesive in terms of humidification optical durability, but there is room for further improvement in the conventionally known active energy ray-curable adhesive composition. Was the current situation.

The present invention has been developed in view of the above circumstances, and an object of the present invention is to provide a laminated optical film having excellent adhesiveness between an optical film and a transparent protective film.

In order to solve the above problems, the present inventors have focused on the interface between the transparent protective film and the adhesive layer provided in the laminated optical film, and have made a diligent study. As a result, it has been found that the above problem can be solved by forming a compatible layer in which the composition of the transparent protective film and the composition of the adhesive layer continuously change at such an interface.

That is, the present invention is a laminated optical film in which a transparent protective film is laminated on at least one surface of the optical film via an adhesive layer formed by curing the adhesive composition, wherein the transparent protective film is provided. The present invention relates to a laminated optical film characterized in that a compatible layer having a continuously changing composition thereof is formed between the film and the adhesive layer.

In the laminated optical film, the SP value distance between the SP value of the transparent protective film and the SP value of the adhesive composition is preferably 12 or less.

In the laminated optical film, the compatible layer was formed by bringing the organic solvent into contact with the surface of the transparent protective film on the side where the adhesive layer is formed, and then applying the adhesive composition. It is preferable that it is a thing.

In the laminated optical film, the optical film coated with the adhesive composition after the compatible layer is brought into contact with an organic solvent on the surface of the transparent protective film on the side where the adhesive layer is formed. , It is preferable that the adhesive composition is formed by laminating the transparent protective film from the coated surface side to the contact surface of the transparent protective film with the organic solvent.

In the laminated optical film, after the compatible layer brings the organic solvent into contact with the surface of the transparent protective film on the side where the adhesive layer is formed, the contact surface of the transparent protective film with the organic solvent and the above. It is formed by applying the adhesive composition to both surfaces of the transparent protective film side surface of the optical film, and laminating the transparent protective film and the optical film from both coated surface sides. It is preferable to have.

In the laminated optical film, the SP value distance between the SP value of the transparent protective film and the SP value of the organic solvent is preferably 12 or less.

In the laminated optical film, it is preferable that the adhesive composition is an active energy ray-curable adhesive composition containing a monomer having a polymerizable group.

In the laminated optical film, it is preferable that the optical film is a polyvinyl alcohol-based polarizing element.

In the laminated optical film, it is preferable that the transparent protective film is at least one thermoplastic resin selected from the group consisting of polyarylate, polycarbonate, acrylic polymer and triacetyl cellulose.

The present invention also relates to a method for producing a laminated optical film in which a transparent protective film is laminated on at least one surface of the optical film via an adhesive layer formed by curing the adhesive composition. A pretreatment step of bringing an organic solvent having an SP value distance of 12 or less from the transparent protective film into contact with the surface of the transparent protective film on the side forming the adhesive layer, and the organic solvent of the transparent protective film. A coating step of directly applying the adhesive composition to at least one surface of the contact surface and the surface of the optical film on the transparent protective film side, and the transparent protective film and the optical film are coated with the adhesive composition. A bonding step of forming a compatible layer in which these compositions continuously change between the transparent protective film and the adhesive layer by bonding through an object, and the optical film surface side or the above. Includes an adhesive step of adhering the optical film and the transparent protective film via an adhesive layer formed by irradiating an active energy ray from the surface side of the transparent protective film to cure the adhesive composition. The present invention relates to a method for manufacturing a laminated optical film.

In the method for producing a laminated optical film, the SP value distance between the SP value of the transparent protective film and the SP value of the adhesive composition is preferably 12 or less.

Further, the present invention relates to an image display device characterized in that the laminated optical film according to any one of the above is used.

In the laminated optical film according to the present invention, a compatible layer in which the composition thereof continuously changes is formed between the transparent protective film and the adhesive layer. This improves the adhesiveness of the laminated optical film due to the improved adhesiveness between the transparent protective film and the adhesive layer. In particular, when the SP value distance between the SP value of the transparent protective film and the SP value of the adhesive composition is 12 or less, the compatible layer is formed more reliably, so that the laminated optical film is finally formed. Adhesiveness is further improved.

In the present invention, the SP value shall mean the dissolution parameter proposed by Hansen et al., And the SP value is represented by one point in the three-dimensional space. The affinity between two substances (for example, a transparent protective film and an adhesive composition) can be evaluated by the distance between the two SP values (SP value distance), and the SP value distance between the two substances is small. It can be said that the affinity is great.

In the present invention, in particular, after the organic solvent is brought into contact with the surface of the transparent protective film on the side forming the adhesive layer, (1) the adhesive composition is applied to the contact surface of the transparent protective film with the organic solvent. , (2) The adhesive composition is applied to the optical film and bonded from the coated surface side of the adhesive composition of the optical film to the contact surface of the transparent protective film with the organic solvent, or (3) the adhesive composition. Is applied to the contact surface of the transparent protective film with the organic solvent, and the adhesive composition is also applied to the optical film, and then the transparent protective film and the optical film are bonded to each other via the adhesive composition. Therefore, a compatible layer can be formed. When the compatible layer is formed in this way, the adhesiveness of the laminated optical film is further improved. The following can be considered as the reasons why such an effect can be obtained.

The transparent protective film, which is a constituent material of the laminated optical film, has a skin layer (a region having a small free volume) on the surface, and has a drawback that the adhesive composition is difficult to penetrate into the skin layer. However, particularly in the laminated optical film provided with the compatible layer formed by the above methods (1) to (3), the skin layer on the surface of the transparent protective film is eliminated, and the adhesive composition easily penetrates. As a result, a compatible layer in which these compositions continuously change is stably and surely formed between the transparent protective film and the adhesive layer, and the adhesiveness of the laminated optical film is further improved.

When the surface of the transparent protective film on the side where the adhesive layer is formed is pretreated with an organic solvent having an SP value distance of 12 or less from the transparent protective film, the surface between the transparent protective film and the adhesive layer is separated. A compatible layer in which these compositions change continuously is formed more stably and reliably, and the optical properties and adhesiveness of the laminated optical film are particularly improved.

The laminated optical film according to the present invention has a transparent protective film laminated on at least one surface of the optical film via an adhesive layer formed by curing the adhesive composition, and is transparently protected. It is characterized in that a compatible layer in which the composition of the transparent protective film and the adhesive layer is continuously changed is formed between the film and the adhesive layer.

The "compatible layer in which the composition of the transparent protective film and the adhesive layer changes continuously" is, for example, (1) a cross-sectional image by a transmission electron microscope (TEM), and (2) a flight time type secondary ion. Confirmed by mass spectrometry (Time-of-Flyght Second Ion Mass Spectrometry; TOF-SIMS) for composition analysis in the depth direction, or (3) 3 wavelength tube inspection, laser microscope, optical interference presence / absence analysis by reflection spectrum, etc. can do.

In the present invention, the compatible layer formed as follows can be exemplified.
(1) A compatible layer formed by contacting an organic solvent with the surface of the transparent protective film on the side forming the adhesive layer and then applying the adhesive composition.
(2) After the organic solvent is brought into contact with the surface of the transparent protective film on the side forming the adhesive layer, the optical film coated with the adhesive composition is applied to the transparent protective film from the coated surface side of the adhesive composition. After the organic solvent is brought into contact with the compatible layer formed by adhering to the contact surface with the organic solvent of (3) the surface on the side where the adhesive layer of the transparent protective film is formed, the organic of the transparent protective film is formed. It was formed by applying an adhesive composition to both the contact surface with the solvent and the surface on the transparent protective film side of the optical film, and laminating the transparent protective film and the optical film from both coated surfaces. Soluble layer.
In any of the above cases (1) to (3), the skin layer existing on the surface of the transparent protective film is eliminated by treating with an organic solvent, and the adhesive composition becomes a transparent protective film. It becomes easy to penetrate, and then the adhesive composition is cured, so that a compatible layer in which these compositions are continuously changed is formed between the transparent protective film and the adhesive layer. In (3) above, an adhesive composition having the same composition may be used as the adhesive composition applied to the transparent protective film and the adhesive composition applied to the optical film, and adhesives having different compositions may be used. An agent composition may be used. However, even when an adhesive composition having a different composition is used, as described later, an adhesive composition having an SP value distance of 12 or less from the SP value of the transparent protective film constituting the laminated optical film shall be used. Is preferable.

The adhesive composition used as a raw material for the adhesive layer included in the laminated optical film will be described below. In the present invention, the adhesive composition can be preferably an active energy ray-curable adhesive composition that can be cured by irradiating with active energy rays to form an adhesive layer.

<Active energy ray-curable adhesive composition>
The active energy ray-curable adhesive composition that can be used in the present invention can be roughly classified into electron beam curability, ultraviolet curability, and visible light curability. Further, the form of curing can be classified into a radical polymerization curing type adhesive composition and a cationically polymerizable adhesive composition. In the present invention, active energy rays having a wavelength range of 10 nm to less than 380 nm are referred to as ultraviolet rays, and active energy rays having a wavelength range of 380 nm to 800 nm are referred to as visible light. In particular, the active energy ray-curable adhesive composition that can be used in the present invention is particularly preferably visible light curable using visible light of 380 nm to 450 nm.

<1: Radical polymerization curable compound>
Examples of the radically polymerizable compound include compounds having a radically 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-functional polyfunctional radical-polymerizable compound can be used. In addition, these radically polymerizable compounds may be used alone or in combination of two or more. As these radically polymerizable compounds, for example, compounds having a (meth) acryloyl group are suitable. In addition, in this invention, (meth) acryloyl means acryloyl group and / or methacryloyl group, and "(meth)" has the same meaning below. Examples of the compound having a (meth) acryloyl group include a (meth) acrylamide derivative having a (meth) acrylamide group and a (meth) acrylate having a (meth) acryloyloxy group. Examples of the compound having a (meth) acryloyl group are exemplified below, but various selections can be made and used, and the compound is not particularly limited. The content of the radically polymerizable compound in the active energy ray-curable adhesive composition of the present invention is preferably 10% by weight or more.

で表される化合物（ただし、Ｒ^１は水素原子またはメチル基であり、Ｒ^２およびＲ^３はそれぞれ独立に、水素原子、アルキル基、ヒドロキシアルキル基、アルコキシアルキル基または環状エーテル基であって、Ｒ^２およびＲ^３は環状複素環を形成してもよい）が挙げられる。アルキル基、ヒドロキシアルキル基、および／またはアルコキシアルキル基のアルキル部分の炭素数は特に限定されないが、例えば１～４個のものが例示される。また、Ｒ^２およびＲ^３が形成してもよい環状複素環は、例えばＮ－アクリロイルモルフォリンが挙げられる。 ≪Monofunctional radically polymerizable compound≫
Examples of the monofunctional radically polymerizable compound include the following general formula (1).

Compounds represented by (where R ¹ is a hydrogen atom or a methyl group, and R ² and R ³ are independently hydrogen atoms, alkyl groups, hydroxyalkyl groups, alkoxyalkyl groups or cyclic ether groups, respectively. R ² and R ³ may form a cyclic heterocycle). The number of carbon atoms in the alkyl portion of the alkyl group, hydroxyalkyl group, and / or alkoxyalkyl group is not particularly limited, and examples thereof include 1 to 4 carbon atoms. Further, examples of the cyclic heterocycle that R ² and R ³ may form include N-acryloylmorpholine.

Specific examples of the compound represented by the general formula (1) include N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, and N-isopropyl ( N-alkyl group-containing (meth) acrylamide derivatives such as meta) acrylamide, N-butyl (meth) acrylamide, N-hexyl (meth) acrylamide; N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N -N-hydroxyalkyl group-containing (meth) acrylamide derivatives such as methylol-N-propane (meth) acrylamide; N-alkoxy group-containing (meth) acrylamide derivatives such as N-methoxymethylacrylamide and N-ethoxymethylacrylamide. Be done. Examples of the cyclic ether group-containing (meth) acrylamide derivative include a heterocycle-containing (meth) acrylamide derivative in which the nitrogen atom of the (meth) acrylamide group forms a heterocycle, and examples thereof include N-acrylloylmorpholine and N. -Acryloylpiperidin, N-methacryloylpiperidin, N-acrylamidepyrrolidine and the like can be mentioned. Among these, N-hydroxyethylacrylamide and N-acryloylmorpholine are preferably used from the viewpoints of excellent reactivity, high elastic modulus of cured product, and excellent adhesion to substituents. can.

For example, from the viewpoint of improving adhesiveness and water resistance when a polarizing element and a transparent protective film are bonded via an adhesive layer, and further improving productivity due to a high polymerization rate, it is generally used in an adhesive composition. The content of the compound represented by the formula (1) is preferably 1 to 50% by weight, more preferably 3 to 20% by weight. In particular, if the content of the compound described in the general formula (1) is too large, the water absorption rate of the cured product may increase and the water resistance may deteriorate.

Further, the adhesive composition used in the present invention may contain another monofunctional radically polymerizable compound as a curable component in addition to the compound represented by the general formula (1). Examples of the monofunctional radically polymerizable compound 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 ( Meta) 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 ( Examples thereof include (meth) acrylic acid (1-20 carbon atoms) alkyl esters such as meth) acrylates and n-octadecyl (meth) acrylates.

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. (Meta) 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 acrylicate, dicyclopentenyloxyethyl (meth) acrylicate, dicyclopentanyl (meth) acrylicate, etc .; 2-methoxyethyl (meth) acrylate, 2-ethoxy Ethyl (meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethylcarbitol (meth) acrylate, phenoxyethyl (meth) acrylate, alkylphenoxypolyethylene glycol (meth) acrylate, etc. An alkoxy group- or phenoxy group-containing (meth) acrylate; and the like. When the resin composition of the present invention is used as an adhesive for a polarizing film, it contains an alkoxy group or a phenoxy group such as phenoxyethyl (meth) acrylate and alkylphenoxypolyethylene glycol (meth) acrylate from the viewpoint of adhesion to a protective film. It preferably contains (meth) acrylate. The content is preferably 1% by weight to 30% by weight with respect to the resin composition.

Examples of the (meth) acrylic acid derivative include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-. Hydroxyalkyl (meth) acrylates such as hydroxybutyl (meth) acrylates, 6-hydroxyhexyl (meth) acrylates, 8-hydroxyoctyl (meth) acrylates, 10-hydroxydecyl (meth) acrylates, 12-hydroxylauryl (meth) acrylates. , [4- (Hydroxymethyl) cyclohexyl] methyl acrylate, cyclohexanedimethanol mono (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate and other hydroxyl group-containing (meth) acrylates; glycidyl (meth) acrylate, Epoxy group-containing (meth) acrylates such as 4-hydroxybutyl (meth) acrylate glycidyl ether; 2,2,2-trifluoroethyl (meth) acrylate, 2,2,2-trifluoroethyl ethyl (meth) acrylate, tetra Halogen-containing (meth) acrylates such as fluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate, and 3-chloro-2-hydroxypropyl (meth) acrylate. ) Acrylate; Alkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate; 3-oxytenylmethyl (meth) acrylate, 3-methyl-oxetanylmethyl (meth) acrylate, 3-ethyl-oxetanylmethyl (meth) acrylate , 3-butyl-oxetanylmethyl (meth) acrylate, 3-hexyluoxetanylmethyl (meth) acrylate and other oxetane group-containing (meth) acrylates; tetrahydrofurfuryl (meth) acrylate, butyrolactone (meth) acrylate, and other heterocycles. Examples thereof include (meth) acrylates having (meth) acrylates, neopentyl glycol (meth) acrylic acid adducts of hydroxypivalate, and p-phenylphenol (meth) acrylates. Of these, 2-hydroxy-3-phenoxypropyl acrylate is preferable because it has excellent adhesion to various protective films.

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 radically polymerizable compound include lactam-based vinyl monomers such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, and methylvinylpyrrolidone; vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, and vinylpyrazine. Examples thereof include vinyl-based monomers having a nitrogen-containing heterocycle such as vinylpyrrole, vinylimidazole, vinyloxazole, and vinylmorpholin.

Further, as the monofunctional radically polymerizable compound, a radically polymerizable compound having an active methylene group can be used. A radically polymerizable compound having an active methylene group is a compound having an active double bond group such as a (meth) acrylic group at the terminal or in the molecule and having an active methylene group. Examples of the active methylene group include an acetoacetyl group, an alkoxymalonyl group, a cyanoacetyl group and the like. The active methylene group is preferably an acetoacetyl group. Specific examples of the radically polymerizable compound having an active methylene group include 2-acetoxyethyl (meth) acrylate, 2-acetoxypropyl (meth) acrylate, 2-acetoxy-1-methylethyl (meth) acrylate and the like. Acetoxyalkyl (meth) acrylate; 2-ethoxymalonyloxyethyl (meth) acrylate, 2-cyanoacetoxyethyl (meth) acrylate, N- (2-cyanoacetoxyethyl) acrylamide, N- (2-propionylacetoxybutyl) Examples thereof include acrylamide, N- (4-acetoxymethylbenzyl) acrylamide, N- (2-acetoacetylaminoethyl) acrylamide and the like. The radically polymerizable compound having an active methylene group is preferably acetoacetoxyalkyl (meth) acrylate.

≪Polyfunctional radically polymerizable compound≫
Examples of the bifunctional or higher polyfunctional radically polymerizable compound include N, N'-methylenebis (meth) acrylamide, tripropylene glycol di (meth) acrylate, and tetraethylene glycol di, which are polyfunctional (meth) acrylamide derivatives. (Meta) acrylate, 1,6-hexanediol di (meth) acrylate, 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 Glycoldi (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, cyclic trimethylolpropaneformal (meth) acrylate, dioxane glycol di (meth) acrylate, trimethylolpropanetri (meth) acrylate, pentaerythritol tri ( (Meta) acrylic acids and polyhydric alcohols such as meta) acrylates, pentaerythritol tetra (meth) acrylates, dipentaerythritol penta (meth) acrylates, dipentaerythritol hexa (meth) acrylates, EO-modified diglycerin tetra (meth) acrylates. Examples thereof include 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.), Light Acrylate DCP-A (manufactured by Kyoeisha Chemical Co., Ltd.). , SR-531 (manufactured by Sartomer), CD-536 (manufactured by Sartomer) and the like are preferable. Further, if necessary, various epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates, various (meth) acrylate-based monomers and the like can be mentioned. The polyfunctional (meth) acrylamide derivative has a high polymerization rate and is excellent in productivity, and is also excellent in crosslinkability when the resin composition is a cured product. Therefore, it is preferable to include the polyfunctional (meth) acrylamide derivative in the adhesive composition.

For the radically polymerizable compound, a monofunctional radically polymerizable compound and a polyfunctional radically polymerizable compound should be used in combination from the viewpoint of achieving both adhesion to a substituent and various transparent protective films and optical durability in a harsh environment. Is preferable. Since the monofunctional radically polymerizable compound has a relatively low liquid viscosity, the liquid viscosity of the resin composition can be lowered by containing it in the resin composition. In addition, monofunctional radically polymerizable compounds often have functional groups that express various functions, and by containing them in the resin composition, various functions are expressed in the resin composition and / or the cured product of the resin composition. Can be made to. The polyfunctional radically polymerizable compound is preferably contained in the resin composition because the cured product of the resin composition can be three-dimensionally crosslinked. The ratio of the monofunctional radically polymerizable compound to the polyfunctional radically polymerizable compound is such that the polyfunctional radically polymerizable compound is mixed in the range of 10 parts by weight to 1000 parts by weight with respect to 100 parts by weight of the monofunctional radically polymerizable compound. Is preferable.

<2: Cationic polymerizable adhesive composition>
The cationically polymerizable compound used in the cationically polymerizable adhesive composition includes a monofunctional cationically polymerizable compound having one cationically polymerizable functional group in the molecule and two or more cationically polymerizable functional groups in the molecule. It is classified as a polyfunctional cationically polymerizable compound having. Since the monofunctional cationically polymerizable compound has a relatively low liquid viscosity, the liquid viscosity of the resin composition can be lowered by containing the monofunctional cationically polymerizable compound in the resin composition. In addition, monofunctional cationically polymerizable compounds often have functional groups that express various functions, and by containing them in the resin composition, various functions are expressed in the resin composition and / or the cured product of the resin composition. Can be made to. The polyfunctional cationically polymerizable compound is preferably contained in the resin composition because the cured product of the resin composition can be three-dimensionally crosslinked. The ratio of the monofunctional cationically polymerizable compound to the polyfunctional cationically polymerizable compound is such that the polyfunctional cationically polymerizable compound is mixed in the range of 10 parts by weight to 1000 parts by weight with respect to 100 parts by weight of the monofunctional cationically polymerizable compound. Is preferable. Examples of the cationically polymerizable functional group include an epoxy group, an oxetanyl group, and a vinyl ether group. Examples of the compound having an epoxy group include an aliphatic epoxy compound, an alicyclic epoxy compound, and an aromatic epoxy compound, and the cationically polymerizable adhesive composition of the present invention is excellent in curability and adhesiveness. It is particularly preferable to contain an alicyclic epoxy compound. Examples of the alicyclic epoxy compound include caprolactone-modified and trimethylcaprolactone-modified products of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate. And valerolactone modified products, and specific examples thereof include seroxide 2021, seroxide 2021A, seroxide 2021P, seroxide 2081, seroxside 2083, and seroxide 2085 (all manufactured by Daicel Chemical Industries, Ltd., Cyclic UVR-6105, Cyclic UVR). -6107, Syracure 30, R-6110 (all manufactured by Dow Chemical Japan Co., Ltd.) and the like. The compound having an oxetanyl group may improve the curability of the cationically polymerizable adhesive composition of the present invention. , It is preferable to contain it because it has the effect of lowering the liquid viscosity of the composition. Examples of the compound having an oxetanyl group include 3-ethyl-3-hydroxymethyloxetane and 1,4-bis [(3-ethyl-). 3-Oxetanyl) methoxymethyl] benzene, 3-ethyl-3- (phenoxymethyl) oxetane, di [(3-ethyl-3-oxetanyl) methyl] ether, 3-ethyl-3- (2-ethylhexyloxymethyl) Examples include oxetane and phenol novolac oxetane, and Aron oxetane OXT-101, Aron oxetane OXT-121, Aron oxetan OXT-221, Aron oxetan OXT-221, Aron oxetan OXT-212 (all manufactured by Toa Synthetic Co., Ltd.) are commercially available. The compound having a vinyl ether group is preferably contained because it has the effect of improving the curability of the cationically polymerizable adhesive composition of the present invention and lowering the liquid viscosity of the composition. Examples of the compound having a group include 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol vinyl ether, triethylene glycol divinyl ether, cyclohexanedimethanol divinyl ether, cyclohexanedimethanol monovinyl ether, and tricyclodecanevinyl ether. Examples thereof include cyclohexylvinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, pentaerythritol type tetravinyl ether and the like.

The bubble suppressant is a compound that can reduce the surface tension of the adhesive composition by blending it in the adhesive composition, and has an effect of reducing bubbles between the adherend and the adherend to be bonded. Examples of the bubble inhibitor include a silicone-based bubble inhibitor having a polysiloxane skeleton such as polydimethylsiloxane, and a (meth) acrylic bubble inhibitor having a (meth) acrylic skeleton obtained by polymerizing a (meth) acrylic acid ester or the like. When added to an adhesive composition, such as a polyether bubble inhibitor obtained by polymerizing vinyl ether or cyclic ether, or a fluorobubble inhibitor composed of a fluorine-based compound having a perfluoroalkyl group, the surface tension is reduced. Anything that has the effect of

Examples of the reactive group of the bubble inhibitor include a polymerizable functional group, and specifically, a radically polymerizable functional group having an ethylenic double bond such as a (meth) acryloyl group, a vinyl group and an allyl group, and glycidyl. Examples thereof include an epoxy group such as a group, an oxetane group, a vinyl ether group, a cyclic ether group, a cyclic thioether group, and a cationically polymerizable functional group such as a lactone group. From the viewpoint of reactivity in the adhesive composition, a bubble inhibitor having a double bond as a reactive group is preferable, and a bubble inhibitor having a (meth) acrylic loyl group is more preferable.

Considering the effect of suppressing Lami bubbles and the effect of improving adhesiveness, a silicone-based bubble suppressant is preferable among the bubble suppressants. Further, among the bubble suppressants, those containing a urethane bond or an isocyanurate ring structure in the main chain skeleton or the side chain are preferable in consideration of the adhesiveness of the adhesive layer. As the silicone-based bubble inhibitor, a commercially available product can also be preferably used, and examples thereof include "BYK-UV3505" (manufactured by Big Chemie Japan) which is an acrylic group-modified polydimethylsiloxane.

In order to achieve both the adhesive strength of the obtained adhesive layer and the effect of reducing lami bubbles, the content of the bubble inhibitor is 0.01 to 0. When the total amount of the adhesive composition is 100% by weight. It is preferably 6% by weight.

<Aspects of Radical Polymerizable Adhesive Composition>
When an electron beam or the like is used for the active energy ray, the adhesive composition does not need to contain a photopolymerization initiator, but when ultraviolet rays or visible light are used for the active energy ray, the adhesive composition. The product preferably contains a photopolymerization initiator.

≪Photopolymerization initiator≫
When a radically polymerizable compound is used, the photopolymerization initiator is appropriately selected by the active energy ray. When curing with ultraviolet rays or visible light, a photopolymerization initiator for ultraviolet or visible light cleavage is used. 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). -Aromatic ketone compounds such as (propyl) ketone, α-hydroxy-α, α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, α-hydroxycyclohexylphenylketone; methoxyacetophenone, 2,2-dimethoxy- Acetphenone compounds such as 2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1- [4- (methylthio) -phenyl] -2-morpholinopropane-1; venzoine methyl ether, Benzoy BR> tower G-tel compounds such as venzoin ethyl ether, benzoin isopropyl ether, venzoin butyl ether and anisoin methyl ether; aromatic ketal compounds such as benzyl dimethyl ketal; 2-naphthalene sulfonyl chloride and the like. Aromatic sulfonyl chloride compounds; photoactive oxime compounds such as 1-phenone-1,1-propanedione-2- (o-ethoxycarbonyl) oxime; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2, Thioxanthone compounds such as 4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone; camphorquinone; halogenated ketone; acylphosphinoxide; acyl Phosphonate and the like can be mentioned.

The blending amount of the photopolymerization initiator is 20% by weight or less with respect to the total amount of the adhesive composition. 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 adhesive composition used in the present invention is used in a visible light curable property containing a radically polymerizable compound as a curable component, a photopolymerization initiator having high sensitivity to light of 380 nm or more is used. Is preferable. A photopolymerization initiator having high sensitivity to light of 380 nm or more will be described later.

（式中、Ｒ^４およびＲ^５は－Ｈ、－ＣＨ_２ＣＨ_３、－ｉＰｒまたはＣｌを示し、Ｒ^４およびＲ^５は同一または異なっても良い）を単独で使用するか、あるいは一般式（２）で表される化合物と後述する３８０ｎｍ以上の光に対して高感度な光重合開始剤とを併用することが好ましい。一般式（２）で表される化合物を使用した場合、３８０ｎｍ以上の光に対して高感度な光重合開始剤を単独で使用した場合に比べて接着性に優れる。一般式（２）で表される化合物の中でも、Ｒ^４およびＲ^５が－ＣＨ_２ＣＨ_３であるジエチルチオキサントンが特に好ましい。接着剤組成物中の一般式（４）で表される化合物の組成比率は、接着剤組成物の全量に対して、０．１～５重量％であることが好ましく、０．５～４重量％であることがより好ましく、０．９～３重量％であることがさらに好ましい。 The photopolymerization initiator is a compound represented by the following general formula (2);

(In the formula, R ⁴ and R ⁵ indicate -H, -CH ₂ CH ₃ , -iPr or Cl, and R ⁴ and R ⁵ may be the same or different) may be used alone or the general formula (in the formula) may be used alone. It is preferable to use the compound represented by 2) in combination with a photopolymerization initiator having high sensitivity to light of 380 nm or more, which will be described later. When the compound represented by the general formula (2) is used, the adhesiveness is excellent as compared with the 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 (2), diethylthioxanthone in which R ⁴ and R ⁵ are −CH ₂ CH ₃ is particularly preferable. The composition ratio of the compound represented by the general formula (4) in the adhesive composition is preferably 0.1 to 5% by weight, preferably 0.5 to 4% by weight, based on the total amount of the adhesive composition. %, More preferably 0.9 to 3% by weight.

In addition, it is preferable to add a polymerization initiation aid as needed. Examples of the polymerization initiation aid include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, and isoamyl 4-dimethylaminobenzoate. , And ethyl 4-dimethylaminobenzoate is particularly preferred. When a polymerization initiator is used, the amount added thereof is usually 0 to 5% by weight, preferably 0 to 4% by weight, and most preferably 0 to 3% by weight, based on the total amount of the adhesive composition.

Further, if necessary, a known photopolymerization initiator can be used in combination. Since the transparent protective film having UV absorption ability does not transmit light of 380 nm or less, it is preferable to use a photopolymerization initiator having high sensitivity to light of 380 nm or more as the photopolymerization initiator. Specifically, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-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-cyclopentadiene-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-) 1-yl) -phenyl) titanium and the like can be mentioned.

（式中、Ｒ^６、Ｒ^７およびＲ^８は－Ｈ、－ＣＨ_３、－ＣＨ_２ＣＨ_３、－ｉＰｒまたはＣｌを示し、Ｒ^６、Ｒ^７およびＲ^８は同一または異なっても良い）を使用することが好ましい。一般式（３）で表される化合物としては、市販品でもある２－メチル－１－（４－メチルチオフェニル）－２－モルフォリノプロパン－１－オン（商品名：ＩＲＧＡＣＵＲＥ９０７ メーカー：ＢＡＳＦ）が好適に使用可能である。その他、２－ベンジル－２－ジメチルアミノ－１－（４－モルフォリノフェニル）－ブタノン－１（商品名：ＩＲＧＡＣＵＲＥ３６９ メーカー：ＢＡＳＦ）、２－（ジメチルアミノ）－２－［（４－メチルフェニル）メチル］－１－［４－（４－モルホリニル）フェニル］－１－ブタノン（商品名：ＩＲＧＡＣＵＲＥ３７９ メーカー：ＢＡＳＦ）が感度が高いため好ましい。 In particular, as the photopolymerization initiator, in addition to the photopolymerization initiator of the general formula (2), a compound represented by the following general formula (3);

(In the formula, R ⁶ , R ⁷ and R ⁸ indicate -H, -CH ₃ , -CH ₂ CH ₃ , -iPr or Cl, and R ⁶ , R ⁷ and R ⁸ may be the same or different). It is preferable to use it. As the compound represented by the general formula (3), 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one (trade name: IRGACURE907 manufacturer: BASF), which is also a commercially available product, is suitable. Can be used for. 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.

<Radical polymerizable compound having an active methylene group and a radical polymerization initiator having a hydrogen abstraction action>
In the above adhesive composition, when a radically polymerizable compound having an active methylene group is used as the radically polymerizable compound, it is preferably used in combination with a radical polymerization initiator having a hydrogen abstraction action. According to such a configuration, the adhesiveness of the adhesive layer of the polarizing film is remarkably improved even immediately after being taken out from a high humidity environment or water (non-drying state). The reason for this is not clear, but it is possible that the cause is <BR>. That is, the radically polymerizable compound having an active methylene group is incorporated into the main chain and / or side chain of the base polymer in the adhesive layer while being polymerized together with other radically polymerizable compounds constituting the adhesive layer, and adheres. Form a layer of agent. In such a polymerization process, when a radical polymerization initiator having a hydrogen abstraction action is present, hydrogen is abstracted from the radical polymerizable compound having an active methylene group to form a methylene group while forming a base polymer constituting the adhesive layer. Radicals are generated. Then, the methylene group in which radicals are generated reacts with the hydroxyl group of a polarizing element such as PVA, and a covalent bond is formed between the adhesive layer and the polarizing element. As a result, it is presumed that the adhesiveness of the adhesive layer of the polarizing film is significantly improved even in a non-drying state.

In the present invention, examples of the radical polymerization initiator having a hydrogen abstraction action include a thioxanthone-based radical polymerization initiator and a benzophenone-based radical polymerization initiator. The radical polymerization initiator is preferably a thioxanthone-based radical polymerization initiator. Examples of the thioxanthone-based radical polymerization initiator include compounds represented by the above general formula (2). Specific examples of the compound represented by the general formula (2) include thioxanthone, dimethylthioxanthone, diethylthioxanthone, isopropylthioxanthone, chlorothioxanthone and the like. Among the compounds represented by the general formula (2), diethylthioxanthone in which R ⁴ and R ⁵ are −CH ₂ CH ₃ is particularly preferable.

When the above adhesive composition contains a radically polymerizable compound having an active methylene group and a radical polymerization initiator having a hydrogen abstraction action, the active methylene is said to be when the total amount of the curable component is 100% by weight. It is preferable to contain 1 to 50% by weight of the radically polymerizable compound having a group and 0.1 to 10% by weight of the radical polymerization initiator with respect to the total amount of the curable resin composition.

As described above, in the present invention, in the presence of a radical polymerization initiator having a hydrogen abstraction action, a radical is generated in the methylene group of the radically polymerizable compound having an active methylene group, and the methylene group and a polarizing element such as PVA are generated. Reacts with the hydroxyl group to form a covalent bond. Therefore, in order to generate a radical in the methylene group of the radically polymerizable compound having an active methylene group and sufficiently form such a covalent bond, the radical having an active methylene group is taken when the total amount of the curable component is 100% by weight. The polymerizable compound is preferably contained in an amount of 1 to 50% by weight, more preferably 3 to 30% by weight. In order to sufficiently improve the water resistance and improve the adhesiveness in a non-drying state, the amount of the radically polymerizable compound having an active methylene group is preferably 1% by weight or more. On the other hand, if it exceeds 50% by weight, poor curing of the adhesive layer may occur. Further, the radical polymerization initiator having a hydrogen abstraction action is preferably contained in an amount of 0.1 to 10% by weight, more preferably 0.3 to 9% by weight, based on the total amount of the adhesive composition. .. In order for the hydrogen abstraction reaction to proceed sufficiently, it is preferable to use 0.1% by weight or more of the radical polymerization initiator. On the other hand, if it exceeds 10% by weight, it may not be completely dissolved in the composition.

<Photocationic polymerization initiator>
The cationically polymerizable adhesive composition contains at least one compound selected from the compound having an epoxy group, the compound having an oxetanyl group, and the compound having a vinyl ether group described above as a curable component, all of which are cationically polymerized. Since it is cured by a photocationic polymerization initiator, a photocationic polymerization initiator is blended. This photocationic polymerization initiator generates a cationic species or Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, and initiates a polymerization reaction of an epoxy group or an oxetanyl group. As the photocationic polymerization initiator, a photoacid generator and a photobase generator can be used, and the photoacid generator described later is preferably used. When the adhesive composition used in the present invention is used with visible light curability, it is particularly preferable to use a photocationic polymerization initiator having high sensitivity to light of 380 nm or more, but the photocationic polymerization initiator is Generally, since it is a compound that exhibits maximum absorption in a wavelength region near 300 nm or shorter, it is possible to add a light sensitizer that exhibits maximum absorption to light in a longer wavelength region, specifically, a wavelength longer than 380 nm. , Sensitive to light of wavelengths in the vicinity of this, can promote the generation of cation species or acids from the photocationic polymerization initiator. Examples of the photosensitizer include anthracene compounds, pyrene compounds, carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, photoreducing dyes and the like. Two or more types may be mixed and used. In particular, anthracene compounds are preferable because they have an excellent photosensitizing effect, and specific examples thereof include Anthracene UVS-1331 and Anthracene UVS-1221 (manufactured by Kawasaki Kasei Chemicals, Inc.). The content of the photosensitizer is preferably 0.1% by weight to 5% by weight, more preferably 0.5% by weight to 3% by weight.

<Other ingredients>
The adhesive composition used in the present invention preferably contains the following components.

<Acrylic oligomer>
The adhesive composition used in the present invention can contain an acrylic oligomer obtained by polymerizing a (meth) acrylic monomer in addition to the curable component according to the radically polymerizable compound. By containing the component in the adhesive composition, the curing shrinkage when irradiating and curing the composition with active energy rays is reduced, and the adhesive and an adherend such as a polarizing element and a transparent protective film can be attached to each other. The interfacial stress can be reduced. As a result, it is possible to suppress a decrease in the adhesiveness between the adhesive layer and the adherend. In order to sufficiently suppress the curing shrinkage of the cured product layer (adhesive layer), the content of the acrylic oligomer is preferably 20% by weight or less, preferably 15% by weight, based on the total amount of the adhesive composition. % Or less is more preferable. If the content of the acrylic oligomer in the adhesive composition is too large, the reaction rate when the composition is irradiated with active energy rays is drastically reduced, which may result in poor curing. On the other hand, the acrylic oligomer is preferably contained in an amount of 3% by weight or more, more preferably 5% by weight or more, based on the total amount of the adhesive composition.

Since the adhesive composition preferably has a low viscosity in consideration of workability and uniformity during coating, it is preferable that the acrylic oligomer obtained by polymerizing the (meth) acrylic monomer also has a low viscosity. .. As the acrylic oligomer having a low viscosity and capable of preventing the adhesive layer from curing and shrinking, those having a weight average molecular weight (Mw) of 15,000 or less are preferable, those having a weight average molecular weight (Mw) of 15,000 or less are more preferable, and those having a weight average molecular weight (Mw) of 5,000 or less are particularly preferable. preferable. On the other hand, in order to sufficiently suppress the curing shrinkage of the cured product layer (adhesive layer), the weight average molecular weight (Mw) of the acrylic oligomer is preferably 500 or more, more preferably 1000 or more. It is particularly preferably 1500 or more. Specific examples of the (meth) acrylic monomer constituting the acrylic oligomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and 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 (Meta) acrylate, 3-pentyl (meth) acrylate, 2,2-dimethylbutyl (meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl ( (Meta) acrylic acid (1-20 carbon atoms) alkyl esters such as meth) acrylates, 4-methyl-2-propylpentyl (meth) acrylates, N-octadecyl (meth) acrylates, and further, for example, cycloalkyl (meth) acrylates. ) 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, etc.) ) Acrylate, 2-norbornylmethyl (meth) acrylate, 5-norbornen-2-yl-methyl (meth) acrylate, 3-methyl-2-norbornylmethyl (meth) acrylate, etc.), containing hydroxyl group (meth) ) Acrylate esters (eg, hydroxyethyl (meth) acrylates, 2-hydroxypropyl (meth) acrylates, 2,3-dihydroxypropylmethyl-butyl (meth) methacrylates, etc.), alkoxy groups or phenoxy group-containing (meth) acrylics. Acid esters (2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethylcarbitol (meth) acrylate, phenoxy Ethyl (meth) acrylates, etc.), epoxy group-containing (meth) acrylic acid esters (eg, glycidyl (meth) acrylates, etc.), halogen-containing (meth) acrylic acid esters (eg, 2,2,2-trifluoroethyl). (Meta) acrylate, 2,2,2- Trifluoroethyl ethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate, etc.), alkylaminoalkyl (meth) Examples include acrylates (eg, dimethylaminoethyl (meth) acrylate, etc.). These (meth) acrylates can be used alone or in combination of two or more. Specific examples of the acrylic oligomer include "ARUFON" manufactured by Toagosei Co., Ltd., "Actflow" manufactured by Soken Chemical Co., Ltd., and "JONCRYL" manufactured by BASF Japan.

<Photoacid generator>
The adhesive composition may contain a photoacid generator. When the adhesive composition contains a photoacid generator, the water resistance and durability of the adhesive layer can be dramatically improved as compared with the case where the photoacid generator is not contained. The photoacid generator can be represented by the following general formula (4).

（ただし、Ｌ^＋は、任意のオニウムカチオンを表す。また、Ｘ^－は、ＰＦ６_６ ^－、ＳｂＦ_６ ^－、ＡｓＦ_６ ^－、ＳｂＣｌ_６ ^－、ＢｉＣｌ_５ ^－、ＳｎＣｌ_６ ^－、ＣｌＯ_４ ^－、ジチオカルバメートアニオン、ＳＣＮ^－よりからなる群より選択されるカウンターアニオンを表す。） General formula (4)

(However, L ⁺ represents an arbitrary onium cation. X ^- is _PF6-6- ^, _SbF6- ^, _AsF6- ^, _SbCl6- ^, _BiCl5- ^, _SnCl6- ^, _ClO4- ^, dithiocarbamate. Represents a counter anion selected from the group consisting of anion, SCN- ⁾ .

Next, the counter anion X ⁻ in the general formula (4) will be described.

The counter anion X ⁻ in the general formula (4) 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 is unlikely to occur in the cation coexisting in the molecule or various materials used in combination, and as a result, the photoacid generator itself represented by the general formula (4) itself. And it is possible to improve the stability of the composition using it over time. The non-nucleophilic anion here refers to an anion having a low ability to cause a nucleophilic reaction. Examples of such anions include _PF6-6- ^, _SbF6- ^, _AsF6- ^, _SbCl6- ^, _BiCl5- ^, _SnCl6- ^, _ClO4- ^, dithiocarbamate anion, SCN- ^and the like.

Specifically, "Cyracure UVI-6992", "Cyracure UVI-6974" (above, manufactured by Dow Chemical Japan Co., Ltd.), "Adeka Putmer SP150", "Adeka Putmer SP152", "Adeka Putmer" "SP170", "ADEKA CORPORATION SP172" (above, ADEKA Corporation), "IRGACURE250" (manufactured by Ciba Specialty Chemicals), "CI-5102", "CI-2855" (above, manufactured by Nippon Soda), "Sun Aid SI-60L", "Sun Aid SI-80L", "Sun Aid SI-100L", "Sun Aid SI-110L", "Sun Aid SI-180L" (all manufactured by Sanshin Chemical Co., Ltd.), "CPI-100P", "CPI-100A" (all manufactured by Sun Apro Co., Ltd.), "WPI-069", "WPI-113", "WPI-116", "WPI-041", "WPI-044", "WPI-054", "WPI-055", "WPAG-281", "WPAG-567", and "WPAG-596" (all manufactured by Wako Pure Chemical Industries, Ltd.) are mentioned as preferable specific examples of the photoacid generator of the present invention.

The content of the photoacid generator is 10% by weight or less, preferably 0.01 to 10% by weight, and preferably 0.05 to 5% by weight, based on the total amount of the adhesive composition. It is more preferably 0.1 to 3% by weight, and particularly preferably 0.1 to 3% by weight.

<Photobase generator>
The photobase generator can function as a catalyst for the polymerization reaction of a radically polymerizable compound or an epoxy resin by changing the molecular structure by irradiation with light such as ultraviolet rays or visible light or by cleaving the molecule. A compound that produces one or more basic substances. Examples of the basic substance are secondary amines and tertiary amines. Examples of the photobase generator include the above-mentioned α-aminoacetophenone compound, the above-mentioned oxime ester compound, an acyloxyimino group, an N-formylated aromatic amino group, an N-acylated aromatic amino group, a nitrobenzyl carbamate group, and an alcohol. Examples thereof include compounds having a substituent such as an oxybenzyl carbamate group. Of these, the oxime ester compound is preferable.

Examples of the compound having an acyloxyimino group include O, O'-diacetophenone succinate oxime, O, O'-dinaphthophenone succinate oxime, and a benzophenone oxime acrylate-styrene copolymer.

Examples of the compound having an N-formylated aromatic amino group and an N-acylated aromatic amino group include di-N- (p-formylamino) diphenylmethane and di-N (p-aceethylamino) diphenylmelan. Di-N- (p-benzoamide) diphenylmethane, 4-formylaminotoluylene, 4-acetylaminotoluylene, 2,4-diformylaminotoluylene, 1-formylaminonaphthalene, 1-acetylaminonaphthalene, 1,5 -Diformylaminonaphthalene, 1-formylaminoanthracene, 1,4-diformylaminoanthracene, 1-acetylaminoanthracene, 1,4-diformylaminoanthraquinone, 1,5-diformylaminoanthracinone, 3,3'- Examples thereof include dimethyl-4,4'-diformylaminobiphenyl and 4,4'-diformylaminobenzophenone.

Examples of the compound having a nitrobenzyl carbamate group and an alcoholoxybenzyl carbamate group include bis {{(2-nitrobenzyl) oxy} carbonyl} diaminodiphenylmethane and 2,4-di {{(2-nitrobenzyl) oxy} toluylene. , Bis {{(2-nitrobenzyloxy) carbonyl} hexane-1,6-diamine, m-xylidine {{(2-nitro-4-chlorobenzyl) oxy} amide}.

The photobase generator is preferably at least one of an oxime ester compound and an α-aminoacetophenone compound, and more preferably an oxime ester compound. As the α-aminoacetophenone compound, a compound having two or more nitrogen atoms is particularly preferable.

As other photobase generators, WPBG-018 (trade name: 9-anthrylmethyl N, N'-dieshylcrabate), WPBG-027 (trade name: (E) -1- [3- (2-hydroxyphenyl) -2-). Propenoyl] piperidine), WPBG-082 (trade name: guanidinium2- (3-benzoylphenyl) probeonate), WPBG-140 (trade name: 1- (anthraquinone-2-yl) ethilix-generating agent, etc.) You can also do it.

<Compound containing either an alkoxy group or an epoxy group>
In the above adhesive composition, a compound containing a photoacid generator and any of an alkoxy group and an epoxy group can be used in combination in the adhesive composition.

(Compounds and polymers with epoxy groups)
When using a compound having one or more epoxy groups in the molecule or a polymer having two or more epoxy groups in the molecule (epoxy resin), two functional groups having reactivity with the epoxy group are contained in the molecule. Compounds having one or more may be used in combination. Here, examples of the functional group having reactivity with the 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 an epoxy resin, a bisphenol A type epoxy resin derived from bisphenol A and epichlorohydrin, and a bisphenol F type epoxy derived from bisphenol F and epichlorohydrin. Resin, bisphenol S type epoxy resin, phenol novolac 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, Naphthalene type epoxy resin, biphenyl type epoxy resin, fluorene type epoxy resin, polyfunctional type epoxy resin such as trifunctional type epoxy resin and tetrafunctional type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, hidden in type epoxy resin , Isocyanurate type epoxy resin, aliphatic chain epoxy resin and the like, and these epoxy resins may be halogenated or hydrogenated. Examples of commercially available epoxy resin products include JER Coat 828, 1001, 801N, 806, 807, 152, 604, 630, 871, YX8000, YX8034, YX4000 manufactured by Japan Epoxy Resin Co., Ltd., and Epicron manufactured by DIC Co., Ltd. 830, EXA835LV, HP4032D, HP820, EP4100 series, EP4000 series, EPU series manufactured by ADEKA Co., Ltd., Serokiside series (2021, 2021P, 2083, 2085, 3000, etc.) manufactured by Daicel Chemical Co., Ltd., Epoxide series, EHPE Series, YD series manufactured by Nippon Steel Chemical Co., Ltd., YDF series, YDCN series, YDB series, phenoxy resin (polyhydroxypolyether synthesized from bisphenols and epichlorohydrin, having epoxy groups at both ends; YP series, etc.), Examples include, but are not limited to, the Denacol series manufactured by Nagase Chemtex and the Epoxy series manufactured by Kyoeisha Chemical Co., Ltd. Two or more of these epoxy resins may be used in combination.

(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. Typical examples of such compounds include melamine compounds, amino resins, and silane coupling agents.

The blending amount of the compound containing either an alkoxy group or an epoxy group is usually 30% by weight or less with respect to the total amount of the adhesive composition, and if the content of the compound in the composition is too large, the adhesiveness becomes poor. It may be reduced and the impact resistance to the drop test may be deteriorated. The content of the compound in the composition is more preferably 20% by weight or less. On the other hand, from the viewpoint of water resistance, the composition preferably contains 2% by weight or more of the compound, and more preferably 5% by weight or more.

<Silane coupling agent>
When the adhesive composition used in the present invention is active energy ray curable, it is preferable to use an active energy ray curable compound as the silane coupling agent, but it is not active energy ray curable. However, the same water resistance can be imparted.

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

Preferred are 3-methacryloxypropyltrimethoxysilane and 3-acryloxypropyltrimethoxysilane.

As a specific example of the silane coupling agent which is not active energy ray curable, the 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, and the like. 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) aminopropyltrimethoxysilane, 3- (N-ethylamino) -2-methylpropyltrimethoxysilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, N- Phenyl-γ-aminopropyltrimethoxysilane, N-benzyl-γ-aminopropyltrimethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldi Amino group-containing silanes such as ethoxymethylsilane, N-phenylaminomethyltrimethoxysilane, (2-aminoethyl) aminomethyltrimethoxysilane, N, N'-bis [3- (trimethoxysilyl) propyl] ethylenediamine; Examples of ketimine-type silanes such as N- (1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propaneamine can be mentioned.

As the silane coupling agent (D1) having an amino group, only one kind may be used, or a plurality of kinds may be used in combination. Of 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-Propylamine is preferred.

The blending amount of the silane coupling agent is preferably in the range of 0.01 to 20% by weight, preferably 0.05 to 15% by weight, and 0.1 to 10% by weight, based on the total amount of the adhesive composition. % Is more preferable. This is because if the blending amount exceeds 20% by weight, the storage stability of the adhesive composition deteriorates, and if it is less than 0.1% by weight, the effect of adhesive water resistance is not sufficiently exhibited.

Specific examples of non-active energy ray-curable silane coupling agents other than the above include 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropyltrimethoxy. Examples thereof include silane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatepropyltriethoxysilane, and imidazole silane.

<Compound with vinyl ether group>
When the adhesive composition used in the present invention contains a compound having a vinyl ether group, it is preferable because the adhesive water resistance between the substituent and the adhesive layer is improved. The reason why such an effect is obtained is not clear, but it is presumed that one of the reasons is that the vinyl ether group of the compound interacts with the substituent to increase the adhesive force between the substituent and the adhesive layer. To. In order to further enhance the adhesive water resistance between the decoder and the adhesive layer, the compound is preferably a radically polymerizable compound having a vinyl ether group. The content of the compound is preferably 0.1 to 19% by weight based on the total amount of the adhesive composition.

<Compounds that cause keto-enol tautomerism>
The adhesive composition used in the present invention may contain a compound that causes keto-enol tautomerism. For example, in an adhesive composition containing a cross-linking agent or an adhesive composition that can be used by blending a cross-linking agent, an embodiment containing the compound that causes the keto-enol tautomer can be preferably adopted. Thereby, the effect of suppressing an excessive increase in viscosity and gelation of the adhesive composition after blending the organometallic compound and the formation of a microgel product, and extending the pot life of the composition can be realized.

As the compound that causes the keto-enol telecommunication, various β-dicarbonyl compounds can be used. Specific examples include acetylacetone, 2,4-hexanedione, 3,5-heptanedione, 2-methylhexane-3,5-dione, 6-methylheptane-2,4-dione, 2,6-dimethylheptane-. Β-diketones such as 3,5-dione; acetoacetate esters such as methyl acetoacetate, ethyl acetoacetate, isopropyl acetoacetate, tert-butyl acetoacetate; ethyl propionyl acetate, ethyl propionyl acetate, isopropyl propionyl acetate, propionyl acetate Propionyl acetates such as tert-butyl; isobutyryl acetates such as ethyl isobutyryl acetate, ethyl isobutyryl acetate, isopropyl isobutyryl acetate, tert-butyl isobutyryl acetate; malonic acid esters such as methyl malonate and ethyl malonate; etc. Can be mentioned. Among them, suitable compounds include acetylacetone and acetoacetic ester. The compound that causes such keto-enol tautomerism may be used alone or in combination of two or more.

The amount of the compound that causes keto-enol tvariability is, for example, 0.05 parts by weight to 10 parts by weight, preferably 0.2 parts by weight to 3 parts by weight (for example, 0.3) with respect to 1 part by weight of the organic metal compound. It can be 2 parts by weight to 2 parts by weight). If the amount of the compound used is less than 0.05 parts by weight with respect to 1 part by weight of the organometallic compound, it may be difficult to exert a sufficient effect of use. On the other hand, if the amount of the compound used exceeds 10 parts by weight with respect to 1 part by weight of the organometallic compound, it may excessively interact with the organometallic compound and it may be difficult to develop the desired water resistance.

<Polyrotaxane>
The adhesive composition of the present invention may contain polyrotaxane. The polyrotaxane is a cyclic molecule, a linear molecule penetrating the opening of the cyclic molecule, and a blockade arranged at both ends of the linear molecule so that the cyclic molecule is not detached from the linear molecule. Has a group and. The cyclic molecule preferably has an active energy ray-curable functional group.

The cyclic molecule is not particularly limited as long as it is a molecule in which a linear molecule is skewered in its opening and can move on the linear molecule and has an active energy ray-polymerizable group. In addition, in this specification, "cyclic" of "cyclic molecule" means substantially "cyclic". That is, the cyclic molecule does not have to be completely ring-closed as long as it is mobile on the linear molecule.

Specific examples of the cyclic molecule include cyclic polymers such as cyclic polyethers, cyclic polyesters, cyclic polyether amines and cyclic polyamines, and cyclodextrins such as α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin. Be done. Among them, cyclodextrins such as α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin are preferable because they are relatively easy to obtain and a large number of types of blocking groups can be selected. Two or more kinds of cyclic molecules may be mixed in the polyrotaxane or in the adhesive.

In the polyrotaxane used in the present invention, the cyclic molecule has an active energy ray-polymerizable group. As a result, the polyrotaxane reacts with the active energy ray-curable component to obtain an adhesive whose cross-linking point is movable even after curing. The active energy ray-polymerizable group contained in the cyclic molecule may be a group that can be polymerized with the above-mentioned active energy ray-curable compound, and for example, a radical polymerizable group such as a (meth) acryloyl group or a (meth) acryloyloxy group may be used. Can be mentioned.

When cyclodextrin is used as the cyclic molecule, the active energy ray-polymerizable group is preferably introduced into the hydroxyl group of the cyclodextrin via any suitable linker. The number of active energy ray-polymerizable groups contained in one molecule of polyrotaxane is preferably 2 to 1280, more preferably 50 to 1000, and even more preferably 90 to 900.

It is preferable that a hydrophobic modifying group is introduced into the cyclic molecule. The introduction of the hydrophobic modifying group may improve the compatibility with the active energy ray-curable component. Further, since hydrophobicity is imparted, it is possible to prevent water from entering the interface between the adhesive layer and the polarizing element when used in a polarizing film, and further improve water resistance. Examples of the hydrophobic modifying group include polyester chains, polyamide chains, alkyl chains, oxyalkylene chains, ether chains and the like. Specific examples include the groups described in [0027] to [0042] of WO2009 / 145073.

A polarizing film using a resin composition containing polyrotaxane as an adhesive has excellent water resistance. The reason why the water resistance of the polarizing film is improved is not clear, but it is presumed as follows. That is, the cross-linking point can move due to the mobility of the cyclic molecule of polyrotaxane (so-called gliding effect), which imparts flexibility to the cured adhesive and increases the adhesion of the substituent to the surface irregularities. As a result, it is considered that the intrusion of water into the interface between the polarizing element and the adhesive layer was prevented. Furthermore, it is considered that the fact that polyrotaxane has a hydrophobic modifying group to impart hydrophobicity to the adhesive also contributed to the prevention of water intrusion into the interface between the polarizing element and the adhesive layer.

The content of polyrotaxane is preferably 2% by weight to 50% by weight with respect to the resin composition.

で表される化合物（ただし、Ｘはビニル基、（メタ）アクリル基、スチリル基、（メタ）アクリルアミド基、ビニルエーテル基、エポキシ基、オキセタン基およびメルカプト基からなる群より選択される少なくとも１種の反応性基を含む官能基であり、Ｒ^９およびＲ^１０はそれぞれ独立に、水素原子、置換基を有してもよい、脂肪族炭化水素基、アリール基、またはヘテロ環基を表す）を含有することができる。一般式（５）に記載の化合物は、ポリビニルアルコール系偏光子が有する水酸基と容易にエステル結合を形成する。また、前記一般式（５）に記載の化合物はさらに反応性基を含むＸを有し、Ｘが含む反応性基を介して接着剤組成物に含まれる他の硬化性成分と反応する。つまり、硬化性樹脂層が有するホウ酸基および／またはホウ酸エステル基が、偏光子が有する水酸基と共有結合を介して強固に接着する。これにより、偏光子と硬化性樹脂層との界面に水分が存在しても、これらが水素結合および／またはイオン結合のみならず、共有結合を介して強固に相互作用しているため、偏光子と硬化性樹脂層との間の接着耐水性が飛躍的に向上する。偏光子と硬化物層との接着性および耐水性向上、特には偏光子と透明保護フィルムとを接着剤層を介して接着させる場合の接着性および耐水性向上の見地から、接着剤組成物中、一般式（５）に記載の化合物の含有量は、０．００１～５０重量％であることが好ましく、０．１～３０重量％であることがより好ましく、１～１０重量％であることが最も好ましい。 The adhesive composition has the following general formula (5):

(However, X is at least one selected from the group consisting of a vinyl group, a (meth) acrylic group, a styryl group, a (meth) acrylamide group, a vinyl ether group, an epoxy group, an oxetane group and a mercapto group. It is a functional group containing a reactive group, and R ⁹ and R ¹⁰ each independently contain a hydrogen atom, a substituent may have a substituent, an aliphatic hydrocarbon group, an aryl group, or a heterocyclic group). can do. The compound of the general formula (5) easily forms an ester bond with the hydroxyl group of the polyvinyl alcohol-based substituent. Further, the compound represented by the general formula (5) further has an X containing a reactive group, and reacts with other curable components contained in the adhesive composition via the reactive group contained in the X. That is, the boric acid group and / or the boric acid ester group of the curable resin layer firmly adheres to the hydroxyl group of the substituent via a covalent bond. As a result, even if water is present at the interface between the polarizing element and the curable resin layer, these are strongly interacting with each other not only through hydrogen bonds and / or ionic bonds but also through covalent bonds. The adhesive water resistance between the and the curable resin layer is dramatically improved. In the adhesive composition, from the viewpoint of improving the adhesiveness and water resistance between the polarizing element and the cured product layer, particularly when the polarizing element and the transparent protective film are bonded via the adhesive layer, the adhesiveness and water resistance are improved. The content of the compound according to the general formula (5) is preferably 0.001 to 50% by weight, more preferably 0.1 to 30% by weight, and more preferably 1 to 10% by weight. Is the most preferable.

<Organometallic compound>
When the adhesive composition of the present invention simultaneously contains at least one organic metal compound selected from the group consisting of a metal alkoxide and a metal chelate and a polymerizable compound having a polymerizable functional group and a carboxyl group, a polarizing element is used. It is preferable because the adhesive water resistance between the metal and the adhesive layer is improved. The organometallic compound becomes an active metal species due to the intervention of moisture, and as a result, the organometallic compound strongly interacts with both the substituent and the active energy ray-curable component constituting the adhesive layer. As a result, even if water is present at the interface between the decoder and the adhesive layer, they strongly interact with each other via the organic metal compound, so that the adhesive water resistance between the ligand and the adhesive layer is high. Is dramatically improved. Although organometallic compounds greatly contribute to improving the adhesiveness and water resistance of the adhesive layer, the composition containing them has a short pot life and productivity due to unstable liquid stability. It tends to get worse. This is because the organic metal compound is highly reactive and comes into contact with a trace amount of water contained in the composition, causing a hydrolysis reaction and a self-condensation reaction, resulting in self-aggregation and whitening of the composition liquid (aggregate). (Generation, phase separation, precipitation) is presumed to be one of the causes. However, when the composition contains a polymerizable compound having a polymerizable functional group and a carboxyl group together with the organic metal compound, the hydrolysis reaction and the self-condensation reaction of the organic metal compound are suppressed, and the organic metal compound in the composition is suppressed. The liquid stability of the above can be dramatically improved. The proportion of the organometallic compound is preferably 0.05 to 15% by weight, more preferably 0.1 to 10% by weight, based on the total amount of the composition. If the blending amount exceeds 15% by weight, the storage stability of the composition may be deteriorated, or the ratio of the components for adhering to the polarizing element or the protective film may be relatively insufficient, and the adhesiveness may be deteriorated. Further, when it is less than 0.05% by weight, the effect of adhesive water resistance is not sufficiently exhibited. When the total amount of the organic metal compound is α (mol) in the curable adhesive composition, the content of the polymerizable compound having a compatible functional group and a carboxyl group is preferably 0.25α (mol) or more. , 0.35α (mol) or more is more preferable, and 0.5α (mol) or more is particularly preferable. When the content of the polymerizable compound having a compatible functional group and a carboxyl group is less than 0.25α (mol), the stabilization of the organometallic compound becomes insufficient, the hydrolysis reaction and the self-condensation reaction proceed, and the pot life May be shortened. The upper limit of the content of the polymerizable compound with respect to the total amount α (mol) of the organometallic compound is not particularly limited, but for example, about 4α (mol) can be exemplified.

<Chlorinated polyolefin>
Chlorinated polyolefin may be blended in the adhesive composition according to the present invention. In this case, the obtained adhesive layer is remarkably reduced in dyeability due to the iodine compound derived from the polyvinyl alcohol-based polarizing element, and functions as a protective layer for suppressing the release / diffusion of the iodine compound from the polarizing element. As a result, when the adhesive composition according to the present invention is used for a polarizing film, the optical durability of the polarizing film is significantly improved. The adhesive composition according to the present invention needs to be optically transparent, and as the polyolefin-based resin, a chlorinated polyolefin that is soluble in an active energy ray-curable component and does not cause layer separation or precipitation is selected. It is preferable to do so. Polyolefins that have not been chlorinated are not preferable because they have extremely low solubility in curable components that are cured by irradiation with active energy rays.

Examples of the chlorinated polyolefin that can be used in the present invention include chlorinated polyethylene, chlorinated polypropylene, acrylic-modified or urethane-modified chlorinated polyolefin.

The chlorine content in the chlorinated polyolefin is preferably 25 to 50% by weight, more preferably 30 to 45% by weight. If it is less than 25% by weight, the solubility in the active energy ray-curable component may decrease, and it may be difficult to form an optically transparent composition. If it exceeds 50% by weight, the change in optical characteristics under severe humidification conditions when the polarizing film is formed becomes large, and the effect of the present invention may not be obtained. The chlorine content in the chlorinated polyolefin can be measured according to JIS-K7229. More specifically, for example, it can be measured by using an "oxygen flask combustion method" in which a chlorine-containing resin is burned in an oxygen atmosphere, the generated gaseous chlorine is absorbed by water, and the amount is quantified by titration.

The weight average molecular weight of the chlorinated polyolefin) is preferably 3,000 to 100,000, more preferably 5,000 to 80,000, and most preferably 10,000 to 20,000. Used. If the molecular weight of the chlorinated polyolefin is too low, the water resistance may not be sufficiently improved when it is made into a cured product. Further, if the molecular weight is too high, the solubility in the active energy ray-curable component may be significantly lowered, and it may be difficult to form an optically transparent composition.

Examples of commercially available chlorinated polyolefins include Supercron series (manufactured by Nippon Paper Chemicals Co., Ltd.), Hardlen series (manufactured by Toyobo Co., Ltd.), and Eraslen series (manufactured by Showa Denko Co., Ltd.). Can be done.

Among the products available on the market, "Supercron 814HS", "Supercron 390S", "Supercron 803MW", "Supercron 803L", "Supercron B", of the Supercron series (manufactured by Nippon Paper Chemicals Co., Ltd.), "Hardlen 16-LP", "Hardlen 15-LP" of the Hardren series (manufactured by Toyobo), "Eraslen 404B", "Eraslen 402B", "Eraslen 401A" of the Eraslen series (manufactured by Showa Denko), etc. It can be preferably used, and in particular, "Supercron 814HS" is more preferably used because it has an excellent balance between solubility in an active energy ray-curable component and stability of optical properties under severe humidification conditions when made into a polarizing film. Can be done.

<Additives other than the above>
In addition, various additives can be added to the adhesive composition used in the present invention as other optional components as long as the purpose and effect of the present invention are not impaired. Examples of such additives include epoxy resins, polyamides, polyamideimides, polyurethanes, polybutadienes, polychloroprenes, polyethers, polyesters, styrene-butadiene block copolymers, petroleum resins, xylene resins, ketone resins, cellulose resins, and fluorooligomers. Polymers or oligomers such as silicone-based oligomers and polysulfide-based oligomers; polymerization inhibitors such as phenothiazine and 2,6-di-t-butyl-4-methylphenol; polymerization initiators; surfactants; plastics; UV absorbers ; Inorganic fillers; Pigments; Dyes and the like can be mentioned.

The above additives are usually 0 to 10% by weight, preferably 0 to 5% by weight, and most preferably 0 to 3% by weight, based on the total amount of the adhesive composition.

<Characteristics of adhesive composition>
As for the SP value of the adhesive composition, the SP value distance between the SP value and the SP value of the transparent protective film constituting the laminated optical film is preferably 12 or less, and more preferably 10 or less. This is preferable because a compatible layer in which these compositions continuously change is more reliably formed between the transparent protective film and the adhesive layer. In the present invention, the SP value of the adhesive composition can be adjusted within a desired range by appropriately adjusting the mixing ratio or the like with reference to the SP value of the monomers constituting the adhesive composition. It is possible. The method for measuring the SP value of the adhesive composition will be described later.

In order to effectively suppress the generation of Lami bubbles, the adhesive composition used in the present invention preferably has a surface tension of 30 mN / m or less before curing. The method for measuring the surface tension of the adhesive composition before curing will be described later.

The adhesive composition used in the present invention preferably has a bulk water absorption rate of 10% by weight or less when the cured product obtained by curing the composition is immersed in pure water at 23 ° C. for 24 hours. The bulk water absorption rate is expressed by the following formula.
Formula: {(M2-M1) / M1} x 100 (%),
However, by setting M1: the weight of the cured product before immersion and M2: the weight of the cured product after immersion to 10% by weight or less, the polarizing film is polarized when it is placed in a harsh high temperature and high humidity environment. The movement of water to the child is suppressed, and the increase in the transmittance of the polarizing element and the decrease in the degree of polarization can be suppressed. The bulk water absorption rate is preferably 5% by weight or less, more preferably 3% by weight or less, from the viewpoint of improving the optical durability of the adhesive layer of the polarizing film in a harsh environment under high temperature. Most preferably, it is 1% by weight or less. On the other hand, when the polarizing element and the transparent protective film are bonded together, the polarizing element retains a certain amount of water, and when the curing adhesive and the water contained in the polarizing element come into contact with each other, repellents, bubbles, etc. Appearance may be poor. In order to suppress poor appearance, it is preferable that the curable adhesive can absorb a certain amount of water. More specifically, the bulk water absorption rate is preferably 0.01% by weight or more, and more preferably 0.05% by weight or more.

The viscosity of the adhesive composition used in the present invention is preferably 3 to 100 mPa · s, more preferably 5 to 50 mPa · s, and most preferably 10 to 30 mPa · s. If the viscosity of the adhesive composition is high, the surface smoothness after coating is poor and the appearance is poor, which is not preferable. The adhesive composition used in the present invention can be applied by heating or cooling the composition to adjust the viscosity to a preferable range.

The adhesive composition used in the present invention preferably has a high octanol / water partition coefficient (hereinafter referred to as logPow value). The logPow value is an index showing the lipophilicity of a substance, and means the logarithmic value of the partition coefficient of octanol / water. A high logPow means that it is lipophilic, that is, it has a low water absorption rate. The logPow value can be measured (the flask dipping method described in JIS-Z-7260), but it is calculated based on the structure of each compound which is a component (curable component, etc.) of the curable adhesive for a polarizing film. It can also be calculated by. In this specification, the logPow value calculated by ChemDraw Ultra manufactured by Cambridge Soft Co., Ltd. is used.
Based on the above calculated values, the logPow value of the curable adhesive for a polarizing film in the present invention can be calculated by the following formula.
Curable adhesive logPow = Σ (logPowi × Wi)
logPowi: logPow value of each component of the curable adhesive Wi: (number of moles of i component) / (total number of moles of each component of the curable adhesive)
In the above calculation, among the components of the curable adhesive, the components that do not form the skeleton of the cured product (adhesive layer) such as the polymerization initiator and the photoacid generator are excluded from the components in the above calculation. The logPow value of the curable adhesive for a polarizing film of the present invention is preferably 1 or more, more preferably 1.5 or more, and most preferably 2 or more. This makes it possible to improve the adhesive water resistance and the humidification durability. On the other hand, the logPow value of the curable adhesive for a polarizing film of the present invention is usually about 8 or less, preferably 5 or less, and more preferably 4 or less. If this logPow value is too high, appearance defects such as cissing and air bubbles are likely to occur as described above, which is not preferable.

Furthermore, it is preferred that the adhesive composition used in the present invention is substantially free of water or volatile solvents. Since it does not substantially contain a volatile solvent, heat treatment is not required, and not only is it excellent in productivity, but it is also preferable because it is possible to suppress deterioration of the optical characteristics of the stator due to heat. "Substantially free" means that, for example, when the total amount of the adhesive composition is 100% by weight or less, it is contained in an amount of less than 5% by weight, and in particular, it is contained in an amount of less than 2% by weight. And.

Further, since the adhesive composition used in the present invention has a curable component, when the adhesive composition is cured, curing shrinkage usually occurs. The curing shrinkage rate is an index showing the rate of curing shrinkage when the adhesive layer is formed from the resin composition. When the curing shrinkage rate of the adhesive layer is large, it is preferable to suppress the occurrence of interfacial strain when the adhesive composition is cured to form the adhesive layer, resulting in poor adhesion. From the above viewpoint, the curing shrinkage rate of the cured product obtained by curing the resin composition having the effect of the present invention is preferably 10% or less. The curing shrinkage rate is preferably small, and the curing shrinkage rate is preferably 8% or less, more preferably 5% or less. The curing shrinkage rate is measured by the method described in Japanese Patent Application Laid-Open No. 2013-104869, and specifically, measured by the method using a curing shrinkage sensor manufactured by Centec Co., Ltd. described in Examples.

Further, from the viewpoint of safety, the adhesive composition used in the present invention preferably uses a material having low skin irritation as the curable component. Skin irritation is described in P.I. I. It can be judged by the index I. P. I. I is widely used to indicate the degree of skin damage and is measured by the drape method. The measured value is displayed in the range of 0 to 8, and it is judged that the smaller the value is, the lower the irritation is, but since the error of the measured value is large, it is better to regard it as a reference value. P. I. I is preferably 4 or less, more preferably 3 or less, and most preferably 2 or less.

The present invention is characterized in that a compatible layer whose composition continuously changes is formed between the transparent protective film constituting the laminated optical film and the adhesive layer. The transparent protective film will be described below.

<Transparent protective film>
As the transparent protective film, in order to form a compatible layer with the adhesive layer, it is preferable to use a transparent protective film that has undergone a pretreatment step in which an organic solvent is brought into contact with the surface on the side where the adhesive layer is formed. Is preferable. In the pretreatment step, for example, the transparent protective film may be dipped in the organic solvent, but in consideration of productivity, it is preferable to apply the organic solvent to the transparent protective film.

The method of applying the organic solvent to the transparent protective film is appropriately selected according to the desired coating thickness, and is, for example, a reverse coater, a gravure coater (direct, reverse or offset), a bar reverse coater, a roll coater, a die coater, etc. Examples include bar coaters and rod coaters.

As the organic solvent, a solvent having an SP value distance of 12 or less from the transparent protective film can be preferably used, and for example, esters such as ethyl acetate, butyl acetate and 2-hydroxyethyl acetate; methyl ethyl ketone, acetone, cyclohexanone, etc. Ketones such as methyl isobutyl ketone, diethyl ketone, methyl-n-propyl ketone and acetylacetone; cyclic ethers such as tetrahydrofuran (THF) and dioxane; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; toluene , Aromatic hydrocarbons such as xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol and cyclohexanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether and the like. Glycol ethers; examples thereof include glycol ether acetates such as diethylene glycol monomethyl ether acetate and diethylene glycol monoethyl ether acetate, and mixtures thereof. As the organic solvent, it is more preferable to use a solvent having an SP value distance of 10 or less from the transparent protective film. The organic solvent used preferably contains substantially no solute, and more specifically, the solute content of the organic solvent is preferably less than 5% by weight, more preferably less than 1% by weight. It is more preferable to use an organic solvent containing no solute. The method for measuring the SP value of the organic solvent will be described later.

As the transparent protective film, a film having an SP value distance of 10 or less from the adhesive composition as a raw material for forming the adhesive layer can be preferably used. The method of measuring the SP value of the transparent protective film will be described later.

The transparent protective film preferably has excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropic property, and the like. 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, and styrene such as polystyrene and acrylonitrile-styrene copolymer (AS resin). Examples thereof include based polymers and polystyrene polymers. 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 polyamides, imide polymers, and sulfone polymers. , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, allylate polymer, polyoxymethylene polymer, epoxy polymer, or the above. Polymer blends and the like are also examples of polymers that form the transparent protective film. Among these, polyarylate, polycarbonate, acrylic polymer and triacetyl cellulose are preferable in the present invention. The transparent protective film may contain one or more suitable additives. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, a color inhibitor, a flame retardant, a nucleating agent, an antistatic agent, a pigment, a colorant and the like. 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 the content of the thermoplastic resin in the transparent protective film is 50% by weight or less, the high transparency inherent in the thermoplastic resin may not be sufficiently exhibited.

The laminated optical film according to the present invention, particularly a polarizing film, is preferably one in which a polarizing element and a transparent protective film having a light transmittance of less than 5% at a wavelength of 365 nm are laminated via an adhesive layer. The adhesive composition used in the present invention contains the above-mentioned photopolymerization initiator of the general formula (2) and irradiates ultraviolet rays through a transparent protective film having UV absorbing ability to cure the adhesive layer. Can be formed. Therefore, the adhesive layer can be cured even in a polarizing film in which a transparent protective film having a UV absorbing ability is laminated on both sides of the polarizing element. However, as a matter of course, the adhesive layer can be cured even in a polarizing film in which a transparent protective film having no UV absorption ability is laminated. The transparent protective film having UV absorption ability means a transparent protective film having a transmittance of less than 10% for light at 380 nm.

Examples of the method for imparting the UV absorbing ability to the transparent protective film include a method of incorporating 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 salt compounds, triazine compounds and the like. ..

In terms of ultraviolet curability or visible light curability, it is preferable to heat the adhesive composition for a polarizing film (warming before irradiation) before irradiating with ultraviolet rays or visible light, in which case the temperature is 40 ° C. or higher. Is preferable, and it is more preferable to heat the temperature to 50 ° C. or higher. Further, it is also preferable to heat the adhesive composition for a polarizing film after irradiation with ultraviolet rays or visible light (heating after irradiation), in which case it is preferable to heat to 40 ° C. or higher, and to heat to 50 ° C. or higher. Is more preferable.

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

As the transparent protective film, Tg (glass transition temperature) is preferably 115 ° C. or higher, more preferably 120 ° C. or higher, still more preferably 125 ° C. or higher, and particularly preferably 130 ° C. or higher. When the Tg is 115 ° C. or higher, the durability of the polarizing film can be excellent. The upper limit of Tg of the transparent protective film is not particularly limited, but is preferably 170 ° C. or lower from the viewpoint of moldability and the like.

The transparent protective film provided on one or both sides of the polarizing element is preferably excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropic property, etc., and has a moisture permeability of 150 g / m ² /. Those having a length of 24 h or less are more preferable, those having a capacity of 140 g / m ² / 24h or less are particularly preferable, and those having a speed of 120 g / m ² / 24h or less are even more preferable. Moisture permeability is determined by the method described in 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; allylate resins; amide resins such as nylon and aromatic polyamides; polyethylene and polypropylene. , Polyethylene-based polymers such as ethylene / propylene copolymers, cyclic olefin-based resins having a cyclo-based or norbornene structure, (meth) acrylic-based resins, or mixtures thereof can be used. Among the resins, a polycarbonate resin, a cyclic polyolefin resin, and a (meth) acrylic resin are preferable, and a cyclic polyolefin resin and a (meth) acrylic resin are particularly preferable.

The thickness of the transparent protective film can be appropriately determined, but is generally preferably 5 to 100 μm in terms of workability such as strength and handleability, and thin layerability. In particular, 10 to 60 μm is preferable, and 20 to 40 μm is more preferable.

As the transparent protective film, a film having a front retardation of less than 40 nm and a thickness direction retardation of less than 80 nm is usually used. The front phase difference Re is represented by Re = (nx-ny) × d. The thickness direction phase difference Rth is represented by Rth = (nx-nz) × d. The Nz coefficient is represented by Nz = (nx-nz) / (nx-ny). [However, the refractive indexes in the slow axis direction, the phase advance axis direction, and the thickness direction of the film are nx, ny, and nz, respectively, and d (nm) is the thickness of the film. The slow axis direction is the direction in which the refractive index in the film surface is maximized. ]. It is preferable that the transparent protective film is not colored as much as possible. A protective film having a retardation value in the thickness direction of −90 nm to +75 nm is preferably used. By using a film having a retardation value (Rth) of −90 nm to +75 nm in the thickness direction, coloring (optical coloring) of the polarizing film caused by the transparent protective film can be almost eliminated. The thickness direction retardation value (Rth) is more preferably −80 nm to +60 nm, and particularly preferably −70 nm to +45 nm.

On the other hand, as the transparent protective film, a retardation plate having a front retardation of 40 nm or more and / or a retardation of thickness direction of 80 nm or more can be used. The frontal phase difference is usually controlled in the range of 40 to 200 nm, and the thickness direction phase difference is usually controlled in the range of 80 to 300 nm. When a retardation plate is used as the transparent protective film, the retardation plate also functions as the transparent protective film, so that the thickness can be reduced.

Examples of the retardation plate include a birefringent film formed by uniaxially or biaxially stretching a polymer material, an alignment film of a liquid crystal polymer, and a film in which an alignment layer of a liquid crystal polymer is supported by a film. The thickness of the retardation plate is not particularly limited, but is generally about 20 to 150 μm. Examples of the polymer material include polyvinyl alcohol, polyvinyl butyral, polymethylvinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, polysulfone, polyethylene terephthalate, polyethylene naphthalate, and polyethersulfone. Polyphenylsulfone, polyphenylene oxide, polyallylsulfone, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose resin, cyclic polyolefin resin (norbornen-based resin), or their binary, ternary various copolymers, and grafts. Examples include polymers and blends. These polymer materials become oriented substances (stretched films) by stretching or the like.

Examples of the liquid crystal polymer include various types of main chain type and side chain type in which a conjugated linear atomic group (mesogen) that imparts liquid crystal orientation is introduced into the main chain or side chain of the polymer. .. Specific examples of the main chain type liquid crystal polymer include a nematically oriented polyester-based liquid crystal polymer, a discotic polymer, and a cholesteric polymer having a structure in which a mesogen group is bonded at a spacer portion that imparts flexibility. As a specific example of the side chain type liquid crystal polymer, polysiloxane, polyacrylate, polymethacrylate or polymalonate is used as a main chain skeleton, and a nematic orientation-imparting para-substitution via a spacer portion composed of a group of conjugated atoms as a side chain. Examples thereof include those having a mesogen moiety composed of a cyclic compound unit. For these liquid crystal polymers, for example, a liquid crystal polymer solution is applied on an alignment-treated surface such as a thin film formed on a glass plate, such as polyimide or polyvinyl alcohol, which has been subjected to rubbing treatment, or an obliquely vapor-deposited silicon oxide. It is performed by developing and heat-treating.

The retardation plate may have an appropriate phase difference according to the purpose of use, for example, for the purpose of compensating for coloring and viewing angle due to birefringence of various wave plates and liquid crystal layers, and may have two or more types. A phase difference plate may be laminated to control optical characteristics such as a phase difference.

The retardation plate has the relationship of nx = ny> nz, nx> ny> nz, nx> ny = nz, nx> nz> ny, nz = ny> ny, nz> ny> ny, nz> ny = ny. Satisfied ones are selected and used according to various uses. It should be noted that ny = nz includes not only the case where ny and nz are completely the same, but also the case where ny and nz are substantially the same.

For example, in a retardation plate satisfying nx> ny> nz, a retardation plate satisfying a frontal phase difference of 40 to 100 nm, a thickness direction phase difference of 100 to 320 nm, and an Nz coefficient of 1.8 to 4.5 is used. Is preferable. For example, in a retardation plate (positive A plate) satisfying nx> ny = nz, it is preferable to use a retardation plate satisfying a front retardation of 100 to 200 nm. For example, in a retardation plate (negative A plate) satisfying nz = nx> ny, it is preferable to use a retardation plate satisfying a front retardation of 100 to 200 nm. For example, in the retardation plate satisfying nx> nz> ny, it is preferable to use a retardation plate having a front retardation of 150 to 300 nm and an Nz coefficient of more than 0 to satisfying 0.7. Further, as described above, for example, those satisfying nx = ny> nz, nz> nx> ny, or nz> nx = ny can be used.

The transparent protective film can be appropriately selected depending on the liquid crystal display device to be applied. For example, in the case of VA (including Vertical Laidnment, MVA, PVA), it is desirable that the transparent protective film on at least one of the polarizing films (cell side) has a phase difference. As a specific phase difference, it is desirable that Re = 0 to 240 nm and Rth = 0 to 500 nm. In terms of the three-dimensional refractive index, the case of nx> ny = nz, nx> ny> nz, nx> nz> ny, nx = ny> nz (positive A plate, biaxial, negative C plate) is desirable. In the VA type, it is preferable to use a combination of a positive A plate and a negative C plate, or a single biaxial film. When the polarizing films are used above and below the liquid crystal cell, the top and bottom of the liquid crystal cell may have a phase difference, or either the top or bottom transparent protective film may have a phase difference.

For example, in the case of IPS (including In-Plane Switching and FFS), either the transparent protective film on one side of the polarizing film has a phase difference or the transparent protective film does not have a phase difference. For example, when it does not have a phase difference, it is desirable that it does not have a phase difference both above and below (cell side) of the liquid crystal cell. When it has a phase difference, it is desirable that one of the upper and lower sides has a phase difference (for example, nx> nz> ny on the upper side) when the upper and lower sides of the liquid crystal cell have a phase difference. A biaxial film that satisfies the relationship, when there is no phase difference on the lower side, or when the positive A plate is on the upper side and the positive C plate is on the lower side). When it has a phase difference, the range of Re = −500 to 500 nm and Rth = −500 to 500 nm is desirable. In terms of the three-dimensional refractive index, nx> ny = nz, nx> nz> ny, nz> nz = ny, nz> nz> ny (positive A plate, biaxial, positive C plate) are desirable.

The transparent protective film may be further laminated with a peelable base material in order to supplement its mechanical strength and handleability. The peelable substrate can be peeled off from the laminate containing the transparent protective film and the polarizing element before or after the transparent protective film and the polarizing element are bonded together, during or in a separate step.

<Optical film>
In the laminated optical film according to the present invention, the optical film is preferably a polarizing element, and in particular, in the present invention, the laminated optical film is formed by curing an adhesive composition on at least one surface of the polarizing element. It is preferably a polarizing film in which a transparent protective film is laminated via an adhesive layer.

<Polarizer>
The polarizing element is not particularly limited, and various types can be used. As the extruder, for example, a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, an ethylene / vinyl acetate copolymerization system partially saponified film, and two colors such as iodine and a dichroic dye are used. Examples thereof include a uniaxially stretched film by adsorbing a sex material, a polyene-based oriented film such as a dehydrated product of polyvinyl alcohol and a dehydrogenated product of polyvinyl chloride. Among these, a polyvinyl alcohol-based film and a polarizing element made of a dichroic substance such as iodine are preferable. The thickness of these splitters is preferably 2 to 30 μm, more preferably 4 to 20 μm, and most preferably 5 to 15 μm. If the thickness of the splitter is thin, the optical durability is lowered, which is not preferable. When the thickness of the polarizing element is thick, the dimensional change becomes large under high temperature and high humidity, which causes a problem of display unevenness, which is not preferable.

A polarizing element obtained by dyeing a polyvinyl alcohol-based film with iodine and uniaxially stretching it can be produced, for example, by immersing polyvinyl alcohol in an aqueous solution of iodine to dye it and stretching it to 3 to 7 times its original length. If necessary, it can be immersed in an aqueous solution such as boric acid or potassium iodide. Further, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed with water before dyeing. By washing the polyvinyl alcohol-based film with water, stains on the surface of the polyvinyl alcohol-based film and anti-blocking agents can be washed, and by swelling the polyvinyl alcohol-based film, it also has the effect of preventing non-uniformity such as uneven dyeing. be. Stretching may be performed after staining with iodine, stretching while staining, or stretching and then staining with iodine. It can be stretched in an aqueous solution such as boric acid or potassium iodide or in a water bath.

Further, the adhesive composition used in the present invention exhibits its effect (satisfying the optical durability in a harsh environment under high temperature and high humidity) when a thin polarizing element having a thickness of 10 μm or less is used as the polarizing element. It can be remarkably expressed. The above-mentioned polarizing element having a thickness of 10 μm or less has a relatively large influence of moisture as compared with a polarizing element having a thickness of more than 10 μm, has insufficient optical durability in an environment of high temperature and high humidity, and has an increased transmittance and a degree of polarization. Decline is likely to occur. That is, when the above-mentioned extruder of 10 μm or less is laminated with the adhesive layer having a bulk water absorption of 10% by weight or less of the present invention, the movement of water to the polarizing element is suppressed in a harsh high temperature and high humidity environment. As a result, deterioration of optical durability such as increase in transmittance and decrease in degree of polarization of the polarizing film can be remarkably suppressed. The thickness of the splitter is preferably 1 to 7 μm from the viewpoint of thinning. It is preferable that such a thin polarizing element has less unevenness in thickness, has excellent visibility, has less dimensional change, and can be made thinner as a polarizing film.

Typical examples of the thin polarizing element include JP-A-51-069644, JP-A-2000-338329, WO2010 / 100917 pamphlet, PCT / JP2010 / 00146, and Japanese Patent Application No. 2010-. The thin polarizing film described in the specification of No. 269002 and the specification of Japanese Patent Application No. 2010-263692 can be mentioned. These thin polarizing films can be obtained by a manufacturing 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 any trouble such as breakage due to stretching because it is supported by the stretching resin base material.

The thin polarizing film can be stretched at a high magnification and can improve the polarization performance even in a manufacturing method including a step of stretching in a laminated state and a step of dyeing. It is preferably obtained by a production method including a step of stretching in a boric acid aqueous solution as described in JP2010 / 00460, or in Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692, particularly preferably. It is preferably obtained by a production method including a step of auxiliary stretching in the air before stretching in the boric acid aqueous solution described in Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692.

で表される化合物（ただし、Ｘは反応性基を含む官能基であり、Ｒ^１０およびＲ^１１はそれぞれ独立に、水素原子、置換基を有してもよい、脂肪族炭化水素基、アリール基、またはヘテロ環基を表す）を備えてもよい。前記脂肪族炭化水素基としては、炭素数１～２０の置換基を有してもよい直鎖または分岐のアルキル基、炭素数３～２０の置換基を有してもよい環状アルキル基、炭素数２～２０のアルケニル基が挙げられ、アリール基としては、炭素数６～２０の置換基を有してもよいフェニル基、炭素数１０～２０の置換基を有してもよいナフチル基等が挙げられ、ヘテロ環基としては例えば、少なくとも一つのヘテロ原子を含む、置換基を有してもよい５員環または６員環の基が挙げられる。これらは互いに連結して環を形成してもよい。一般式（６）中、Ｒ^１０およびＲ^１１として好ましくは、水素原子、炭素数１～３の直鎖または分岐のアルキル基であり、最も好ましくは、水素原子である。なお、一般式（６）で表される化合物は積層光学フィルム中で、未反応の状態で偏光子と接着剤層との間および／または透明保護フィルムと接着剤層との間に介在しても良く、各官能基が反応した状態で介在しても良い。また、「偏光子の貼合面に、一般式（６）で表される化合物を備える」とは、例えば一般式（６）で表される化合物が、該貼合面に少なくとも１分子存在することを意味する。ただし、偏光子と接着剤層との間の接着耐水性を十分に向上させるためには、一般式（６）で表される化合物を含む易接着組成物を用いて、易接着層を該貼合面の少なくとも一部に形成することが好ましく、該貼合面の全面に易接着層を形成することがより好ましい。 In the present invention, the following general formula (6):

(However, X is a functional group containing a reactive group, and R ¹⁰ and R ¹¹ may independently have a hydrogen atom and a substituent, respectively, an aliphatic hydrocarbon group and an aryl group. , Or a heterocyclic group). The aliphatic hydrocarbon group includes a linear or branched alkyl group which may have a substituent having 1 to 20 carbon atoms, a cyclic alkyl group which may have a substituent having 3 to 20 carbon atoms, and carbon. Examples thereof include an alkenyl group having a number of 2 to 20, and examples of the aryl group include a phenyl group which may have a substituent having 6 to 20 carbon atoms, a naphthyl group which may have a substituent having 10 to 20 carbon atoms and the like. Examples of the heterocyclic group include a 5-membered or 6-membered ring group which may have a substituent and contains at least one heteroatom. These may be connected to each other to form a ring. In the general formula (6), R ¹⁰ and R ¹¹ are preferably a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, and most preferably a hydrogen atom. The compound represented by the general formula (6) is interposed in the laminated optical film between the substituent and the adhesive layer and / or between the transparent protective film and the adhesive layer in an unreacted state. It is also possible to intervene in a state where each functional group has reacted. Further, "the compound represented by the general formula (6) is provided on the bonded surface of the polarizing element" means that, for example, at least one molecule of the compound represented by the general formula (6) is present on the bonded surface. Means that. However, in order to sufficiently improve the adhesive water resistance between the polarizing element and the adhesive layer, the easy-adhesive layer is attached by using an easy-adhesive composition containing a compound represented by the general formula (6). It is preferable to form it on at least a part of the mating surface, and it is more preferable to form an easy-adhesive layer on the entire surface of the mating surface.

X contained in the compound represented by the general formula (6) is a functional group containing a reactive group, which is a functional group capable of reacting with a curable component constituting the adhesive layer, and is a reactive group contained in X. For example, hydroxyl group, amino group, aldehyde group, carboxyl group, vinyl group, (meth) acrylic group, styryl group, (meth) acrylamide group, vinyl ether group, epoxy group, oxetane group, α, β-unsaturated carbonyl. Groups, mercapto groups, halogen groups and the like can be mentioned. When the curable resin composition constituting the adhesive layer is active energy ray curable, the reactive group contained in X is a vinyl group, a (meth) acrylic group, a styryl group, a (meth) acrylamide group, a vinyl ether group, and the like. It is preferably at least one reactive group selected from the group consisting of an epoxy group, an oxetane group and a mercapto group, and X is particularly when the curable resin composition constituting the adhesive layer is radically polymerizable. The reactive group contained is preferably at least one reactive group selected from the group consisting of a (meth) acrylic group, a styryl group and a (meth) acrylamide group, and is a compound represented by the general formula (6). When has a (meth) acrylamide group, it is more preferable because it has high reactivity and the copolymerization rate with the active energy ray-curable resin composition is increased. Further, since the (meth) acrylamide group has a high polarity and excellent adhesiveness, the effect of the present invention can be efficiently obtained, which is also preferable. When the curable resin composition constituting the adhesive layer is cationically polymerizable, the reactive group contained in X is composed of a hydroxyl group, an amino group, an aldehyde, a carboxyl group, a vinyl ether group, an epoxy group, an oxetane group and a mercapto group. It is preferable to have at least one functional group selected, particularly when it has an epoxy group, it is preferable because it has excellent adhesion between the obtained curable resin layer and the adherend, and when it has a vinyl ether group, it is a curable resin composition. It is preferable because it has excellent curability.

で表される化合物（ただし、Ｙは有機基であり、Ｘ、Ｒ^１０およびＲ^１１は前記と同じ）が挙げられる。さらに好適には、以下の化合物（６ａ）～（６ｄ）が挙げられる。

As a preferable specific example of the compound represented by the general formula (6), the following general formula (6')

Examples thereof include compounds represented by (where Y is an organic group and X, R ¹⁰ and R ¹¹ are the same as described above). More preferably, the following compounds (6a) to (6d) can be mentioned.

In the present invention, the compound represented by the general formula (6) may be a compound in which a reactive group and a boron atom are directly bonded, but as shown in the above specific example, the general formula (6) It is preferable that the compound represented by (1) is a compound in which a reactive group and a boron atom are bonded via an organic group, that is, a compound represented by the general formula (6'). When the compound represented by the general formula (6) is bonded to a reactive group via, for example, an oxygen atom bonded to a boron atom, the adhesive water resistance of the polarizing film tends to deteriorate. On the other hand, the compound represented by the general formula (1) does not have a boron-oxygen bond, but contains a reactive group while having a boron-carbon bond by bonding a boron atom and an organic group. When it is a compound (general formula (6')), it is preferable because the adhesive water resistance of the polarizing film is improved. The organic group specifically means an organic group having 1 to 20 carbon atoms which may have a substituent, and more specifically, for example, having a substituent having 1 to 20 carbon atoms. It may have a linear or branched alkylene group, a cyclic alkylene group which may have a substituent having 3 to 20 carbon atoms, a phenylene group which may have a substituent having 6 to 20 carbon atoms, and 10 to 10 carbon atoms. Examples thereof include a naphthylene group which may have 20 substituents.

In addition to the above-exemplified compounds, the compounds represented by the general formula (6) include hydroxyethyl acrylamide and an ester of boric acid, methylol acrylamide and an ester of boric acid, hydroxyethyl acrylate and an ester of boric acid, and hydroxybutyl. Esters of (meth) acrylate and boric acid, such as esters of acrylate and boric acid, can be exemplified.

As a method for forming an easy-adhesion layer using the easy-adhesion composition containing the compound represented by the general formula (6) on the bonded surface of the polarizing element, for example, the compound represented by the general formula (6) is included. Examples thereof include a method of producing the easy-adhesion composition (A) and applying it to the bonding surface of the polarizing element. ), Examples of the compound which may be contained in addition to the compound represented by) include a solvent and an additive.

When the easy-adhesion composition (A) contains a solvent, the composition (A) may be applied to the bonded surface of the polarizing element, and a drying step or a curing treatment (heat treatment or the like) may be performed as necessary.

As the solvent that may be contained in the easy-adhesion composition (A), a solvent capable of stabilizing the compound represented by the general formula (6) and dissolving or dispersing it is preferable. As such a solvent, an organic solvent, water, or a mixed solvent thereof can be used. Examples of the solvent include esters such as ethyl acetate, butyl acetate and 2-hydroxyethyl acetate; ketones such as methyl ethyl ketone, acetone, cyclohexanone, methyl isobutyl ketone, diethyl ketone, methyl-n-propyl ketone and acetyl acetone; tetrahydrofuran ( Cyclic ethers such as THF), dioxane; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; methanol, ethanol, n-propanol, isopropanol and cyclohexanol. Lipid or alicyclic alcohols such as; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether; glycol ether acetates such as diethylene glycol monomethyl ether acetate and diethylene glycol monoethyl ether acetate; etc. Is selected from.

Additives that may be included in the easy-adhesive composition (A) include, for example, surfactants, plasticizers, tackifiers, low molecular weight polymers, polymerizable monomers, surface lubricants, leveling agents, antioxidants, corrosion inhibitors. Agents, light stabilizers, UV absorbers, polymerization inhibitors, silane coupling agents, titanium coupling agents, inorganic or organic fillers, metal powders, particles, foils and the like.

When the easy-adhesion composition (A) contains a polymerization initiator, the compound represented by the general formula (6) may react in the easy-adhesion layer before laminating the adhesive layer. In some cases, the effect of improving the adhesive water resistance of the polarizing film, which is the purpose of the above, cannot be sufficiently obtained. Therefore, the content of the polymerization initiator in the easy-adhesion layer is preferably less than 2% by weight, preferably less than 0.5% by weight, and particularly preferably no polymerization initiator.

If the content of the compound represented by the general formula (6) in the easy-adhesion layer is too small, the proportion of the compound represented by the general formula (6) present on the surface of the easy-adhesion layer decreases, and the easy-adhesion effect is obtained. May be lower. Therefore, the content of the compound represented by the general formula (1) in the easy-adhesion layer is preferably 1% by weight or more, more preferably 20% by weight or more, and more preferably 40% by weight or more. Is even more preferable.

As a method for forming the easy-adhesion layer on the polarizing element by using the easy-adhesion composition (A), a method of directly immersing the polarizing element in the treatment bath of the composition (A) or a known coating method is appropriately used. .. Specific examples of the coating method include, but are not limited to, a roll coat, a gravure coat, a reverse coat, a roll brush, a spray coat, an air knife coat, and a curtain coat method.

In the present invention, if the thickness of the easy-adhesion layer included in the polarizing element is too thick, the cohesive force of the easy-adhesion layer may decrease, and the easy-adhesion effect may decrease. Therefore, the thickness of the easy-adhesion layer is preferably 2000 nm or less, more preferably 1000 nm or less, and further preferably 500 nm or less. On the other hand, as the lowermost limit of the thickness for the easy-adhesion layer to fully exert its effect, at least the thickness of the monolayer of the compound represented by the general formula (1) can be mentioned, preferably 1 nm or more, and more. It is preferably 2 nm or more, and more preferably 3 nm or more.

When the easy-adhesion layer is formed on the bonding surface of the polarizing element, in addition to the compound described in the general formula (6) in the easy-adhesion layer formed on the bonding surface of the polarizing element, M- is added to the structural formula. It may contain a compound having an O bond (M is silicon, titanium, aluminum, zirconium and O represents an oxygen atom). In particular, in the present invention, the compound having an MO bond is preferably an organosilicon compound and at least one organometallic compound selected from the group consisting of a metal alkoxide and a metal chelate.

As the organosilicon compound, a compound having a Si—O bond can be used without particular limitation, and specific examples thereof include an organosilicon compound having an active energy ray curability or an organosilicon compound having no active energy ray curability. Can be mentioned. In particular, it is preferable that the organic group of the organosilicon compound has 3 or more carbon atoms. Active energy ray-curable compounds include vinyl trichlorosilane, vinyl trimethoxysilane, vinyl triethoxysilane, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycid. Xipropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxy Examples thereof include silane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane.

Preferred are 3-methacryloxypropyltrimethoxysilane and 3-acryloxypropyltrimethoxysilane.

As a specific example of the compound which is not active energy ray curable, a compound having an amino group is preferable. Specific examples of the compound having an amino group include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropylmethyldimethoxysilane, and γ-aminopropylmethyldi. Ethoxysilane, 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) Aminopropyltrimethoxysilane, 3- (N-ethylamino) -2-methylpropyltrimethoxysilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, N-phenyl-γ-aminopropyl Trimethoxysilane, N-benzyl-γ-aminopropyltrimethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane, N- Amine group-containing silanes such as phenylaminomethyltrimethoxysilane, (2-aminoethyl) aminomethyltrimethoxysilane, N, N'-bis [3- (trimethoxysilyl) propyl] ethylenediamine; N- (1,3) -Cetimine-type silanes such as dimethylbutylidene) -3- (triethoxysilyl) -1-propaneamine can be mentioned.

As the compound having an amino group, only one kind may be used, or a plurality of kinds may be used in combination. Of 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-Propylamine is preferred.

Specific examples of non-active energy ray-curable compounds other than the above include 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and bis. (Triethoxysilylpropyl) Tetrasulfide, 3-Isoxypropyltriethoxysilane, imidazolesilane and the like can be mentioned.

A metal alkoxy is a compound in which at least one alkoxy group, which is an organic group, is bonded to a metal, and a metal chelate is a compound in which an organic group is bonded or coordinated to a metal via an oxygen atom. As the metal, titanium, aluminum and zirconium are preferable. Among these, aluminum and zirconium have faster reactivity than titanium, and the pot life of the composition (A) forming the easy-adhesion layer may be shortened, and the effect of improving the adhesive water resistance may be reduced. Therefore, titanium is more preferable as the metal of the organometallic compound from the viewpoint of improving the adhesive water resistance of the easy-adhesive layer.

When the easy-adhesion composition (A) for forming the easy-adhesion layer contains a metal alkoxide as an organometallic compound, it is preferable to use one having an organic group having 3 or more carbon atoms in the metal alkoxide. It is more preferable to contain the above. When the number of carbon atoms is 2 or less, the pot life of the composition (A) may be shortened, and the effect of improving the adhesive water resistance may be reduced. Examples of the organic group having 6 or more carbon atoms include an octoxy group, which can be suitably used. Examples of suitable metal alkoxides include, for example, tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetraoctyl titanate, tertiary aluminum titanate, tetraterlary butyl titanate, tetrastearyl titanate, zirconium tetraisopropoxide, zirconium. Tetranormal butoxide, zirconium tetraoctoxide, zirconium tetratershary butoxide, zirconium tetrapropoxide, aluminum sec butyrate, aluminum ethylate, aluminum isoprepilate, aluminum butyrate, aluminum diisopropyrate monosecondary butyrate, monosec butoxyaluminum Diisopropoxide, etc. may be mentioned. Of these, tetraoctyl titanate is preferable.

When the easy-adhesion composition (A) for forming the easy-adhesion layer contains a metal chelate as an organometallic compound, it is preferable that the metal chelate contains an organic group having 3 or more carbon atoms. When the number of carbon atoms is 2 or less, the pot life of the easy-adhesion composition (A) may be shortened, and the effect of improving the adhesive water resistance may be reduced. Examples of the organic group having 3 or more carbon atoms include an acetylacetonate group, an ethylacetacetate group, an isostearate group, and an octylene glycolate group. Among these, an acetylacetonate group or an ethylacetacetate group is preferable as the organic group from the viewpoint of improving the adhesive water resistance of the easy-adhesion layer. Examples of suitable metal chelates include, for example, titanium acetylacetonate, titanium octylene glycolate, titanium tetraacetylacetonate, titanium ethylacetacetate, polyhydroxytitanium stearate, dipropoxybis (acetylacetonato) titanium, di. Butoxytitanium-bis (octylene glycolate), dipropoxytitanium-bis (ethylacetoacetate), titanium lactate, titanium diethanolaminate, titaniumtriethanolaminate, dipropoxytitanium-bis (lactate), dipropoxytitanium-bis ( Triethanol aminate), di-n-butoxytitanium-bis (triethanolaminate), tri-n-butoxytitanium monostearate, diisopropoxybis (ethylacetoacetate) titanium, diisopropoxybis (acetyl) Acetate) Titanium, Diisopropoxy-bis (Acetylacetone) Titanium, Titanium Phosphate Compound, Titanium Lactate Ammium Salt, Titanium-1,3-Propanedioxybis (Ethylacet Acetate), Titanium Dodecylbenzenesulfonate Compound, Titanium Aminoethyl Amino etanolate, zirconium tetraacetylacetonate, zirconium monoacetylacetonate, zirconium bisacetylacetonate, zirconium acetylacetonate bisethylacetoneacetate, zirconium acetate, tri-n-butoxyethylacetone acetate zirconium, di-n-butoxybis ( Ethylacetacetate) zirconium, n-butoxytris (ethylacetate acetate) zirconium, tetrakis (n-propylacetone acetate) zirconium, tetrakis (acetylacetate acetate) zirconium, tetrakis (ethylacetate acetate) zirconium, aluminum ethylacetate acetate, aluminum acetyl Acetylacetone, Aluminum Acetylacetone Bisethylacetate, Diisopropoxyethylacetoneacetate Aluminum, Diisopropoxyacetylacetonate Aluminum, Isopropoxybis (Ethylacetoneacetate) Aluminum, Isopropoxybis (Acetylacetonate) Aluminum, Tris ( Ethylacetacetate) Aluminum, Tris (Acetylacetonet) Aluminum, Monoacetylacetonate Bis (Ethylacetoneacete) G) Aluminum is mentioned. Of these, titanium acetylacetonate and titanium ethylacetate acetate are preferable.

In addition to the above, the organic metal compounds that can be used in the present invention include organic carboxylic acid metal salts such as zinc octylate, zinc laurate, zinc stearate, and tin octylate, acetylacetone zinc chelate, benzoylacetone zinc chelate, and dibenzoylmethane zinc. Examples thereof include zinc chelating compounds such as chelate and ethyl acetoacetate zinc chelating.

The content of the compound having an MO bond in the easy-adhesion layer is preferably 0 to 90% by weight, more preferably 1 to 70% by weight, and particularly preferably 10 to 50% by weight. preferable.

The polarizing element and the transparent protective film may be subjected to a surface modification treatment before laminating the above-mentioned adhesive composition. In particular, it is preferable that the surface of the polarizing element is surface-modified before the adhesive composition is applied or bonded. Examples of the surface modification treatment include treatments such as corona treatment, plasma treatment, itro treatment, excimer treatment, and low-pressure UV treatment, and corona treatment is particularly preferable. By performing the corona treatment, polar functional groups such as a carbonyl group and an amino group are generated on the surface of the polarizing element, and the adhesion to the curable resin layer is improved. In addition, foreign matter on the surface is removed by the ashing effect, and unevenness on the surface is reduced, so that a polarizing film having excellent appearance characteristics can be produced.

When the surface modifying treatment is applied to the polarizing element, it is preferable that the surface roughness of the surface of the polarizing element is 0.6 nm or more. The surface roughness is preferably 0.8 nm or more, more preferably 1 nm or more. By setting the surface roughness to 0.6 nm or more, the polarizing element can be satisfactorily conveyed even when the surface of the polarizing element is brought into contact with the guide roll in the manufacturing process of the polarizing film. If the surface roughness becomes too large, the temperature and water resistance deteriorates. Therefore, the surface roughness is preferably 10 nm or less, and more preferably 5 nm or less.

The measurement of the surface roughness is a parameter representing the surface roughness by the calculated average roughness (the average value of the unevenness of the surface). The surface roughness is measured in the Tapping mode using an atomic force microscope (AFM) Nanoscape IV manufactured by Beeco. For the cantilever, for example, a metrology probe: Tap300 (RTESS type) was used. The measuring range is 1 μm square.

<Polarizing film>
The thickness of the polarizing film obtained by laminating a polyvinyl alcohol-based polarizing element, an adhesive layer, a transparent protective film, and an adhesive layer, if necessary, is preferably 150 μm or less, and more preferably 100 μm or less. If the thickness of the polarizing film is too thick, the dimensional change becomes large under high temperature and high humidity, which causes a problem of display unevenness, which is not preferable.

The thickness of the cured product layer formed of the adhesive composition, particularly the adhesive layer, is preferably 0.2 to 3 μm. If the thickness of the cured product layer is too thin, the cohesive force of the cured product layer is insufficient and the peeling force is reduced, which is not preferable. If the thickness of the cured product layer is too thick, peeling is likely to occur when a stress is applied to the cross section of the polarizing film, and peeling failure due to impact occurs, which is not preferable. The thickness of the adhesive layer is more preferably 0.3 to 2 μm, and most preferably 0.4 to 1.5 μm.

Further, when the thickness of the adhesive layer is dμm and the content of the bubble inhibitor contained in the adhesive layer is y% by weight, when the following formula (1) is satisfied, the effect of suppressing lami bubbles and the effect of improving the adhesiveness are obtained. It is preferable because it can achieve both.
0.1-0.02d ≤ y ≤ 0.6-0.08d (1)

The laminated optical film according to the present invention, particularly the polarizing film, is produced by the following manufacturing method;
A method for producing a laminated optical film in which a transparent protective film is laminated via an adhesive layer formed by curing an adhesive composition on at least one surface of the optical film, which is an adhesive for the transparent protective film. A pretreatment step in which an organic solvent having an SP value distance of 10 or less from the transparent protective film is brought into contact with the surface on the side forming the layer, the contact surface with the organic solvent of the transparent protective film, and the transparent protective film side of the optical film. By directly applying the adhesive composition to at least one surface of the surface and bonding the transparent protective film and the optical film via the adhesive composition, the transparent protective film and the adhesive layer are adhered to each other. The adhesive composition is cured by irradiating an active energy ray from the optical film surface side or the transparent protective film surface side with the bonding step of forming a compatible layer in which these compositions continuously change. A method for producing a laminated optical film, which comprises an adhesive step of adhering an optical film and a transparent protective film via an adhesive layer formed by the adhesive layer.
Can be manufactured by. Here, the SP value distance between the SP value of the transparent protective film and the SP value of the adhesive composition is preferably 10 or less.

The method for applying the adhesive composition is appropriately selected depending on the viscosity of the composition and the desired thickness, and is, for example, a reverse coater, a gravure coater (direct, reverse or offset), a bar reverse coater, a roll coater, or a die coater. , Bar coater, rod coater, etc.

Normally, when laminating two films, it is customary to apply the adhesive composition to the laminating surface of the film on one side, for example, the contact surface of the transparent protective film with the organic solvent, and laminating the films on both sides. By applying an adhesive layer to both the surface of the transparent protective film in contact with the organic solvent and the surface of the optical film on the transparent protective film side, and then laminating the adhesive layer, the appearance quality is excellent. A laminated film can be obtained. As the coating method, a post-weighing coating method is preferable. In the present invention, the "post-measurement coating method" means a method of applying an external force to the liquid film to remove excess liquid to obtain a predetermined coating film thickness. In the method for producing a polarizing film according to the present invention, when an external force applied to a liquid film made of an adhesive composition is applied, foreign substances such as dust and dirt existing on the bonded surface are scraped off. Specific examples of the post-weighing coating method include a gravure roll coating method, a forward roll coating method, an air knife coating method, a rod / bar coating method, and the like. From the viewpoint of properties and the like, in the present invention, it is preferable that the coating method is a gravure roll coating method using a gravure roll.

The polarizing element and the transparent protective film can be bonded to each other via the adhesive composition coated as described above. The polarizing element and the transparent protective film can be bonded by a roll laminator or the like. The method of laminating the protective film on both sides of the stator is the method of laminating the polarizing element and one protective film and then the other protective film, and the method of laminating the splitter and the two protective films at the same time. It is selected from the methods that can be matched. The biting bubbles generated during bonding can be significantly reduced by adopting the former method, that is, the method of bonding the polarizing element and one protective film and then bonding another protective film. It is preferable because it can be used.

The active energy rays used in the curing step can be roughly classified into electron beam curability, ultraviolet curability, and visible light curability. In the present invention, active energy rays having a wavelength range of 10 nm to less than 380 nm are referred to as ultraviolet rays, and active energy rays having a wavelength range of 380 nm to 800 nm are referred to as visible light. In the production of the polarizing film according to the present invention, it is particularly preferable to use visible light of 380 nm to 450 nm.

In the laminated optical film according to the present invention, particularly the polarizing film, the adhesive composition for a polarizing film is directly applied to the polarizing element and / or the transparent protective film, and after the polarizing element and the transparent protective film are bonded to each other, the adhesive composition is applied. The adhesive composition is cured by irradiating it with active energy rays (electron beam, ultraviolet rays, visible light, etc.) to form an adhesive layer. The irradiation direction of the active energy ray (electron beam, ultraviolet ray, visible light, etc.) can be any appropriate direction. Irradiation is preferably performed from the transparent protective film side. When irradiated from the splitter side, the substituent may be deteriorated by active energy rays (electron beam, ultraviolet rays, visible light, etc.).

In terms of electron beam curability, any appropriate conditions can be adopted as the electron beam irradiation conditions as long as the adhesive composition for a polarizing film can be cured. For example, in 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 composition for the polarizing film and the curing may be insufficient. If the acceleration voltage exceeds 300 kV, the penetrating power through the sample is too strong and the transparent protective film. And may damage the polarizing element. 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 composition for a polarizing film is insufficiently cured, and when it exceeds 100 kGy, the transparent protective film and the polarizing element are damaged, the mechanical strength is lowered and yellowing occurs, and a predetermined value is obtained. Optical characteristics cannot be obtained.

The electron beam irradiation is usually performed in an inert gas, but if necessary, it may be performed in the atmosphere or under conditions where a small amount of oxygen is introduced. Although it depends on the material of the transparent protective film, by appropriately introducing oxygen, oxygen inhibition can be caused on the surface of the transparent protective film to which the electron beam first hits, and damage to the transparent protective film can be prevented, only for the adhesive. It is possible to efficiently irradiate the electron beam.

In the method for producing a laminated optical film, particularly a polarizing film according to the present invention, the active energy rays include visible light having a wavelength range of 380 nm to 450 nm, and particularly, the irradiation amount of visible light having a wavelength range of 380 nm to 450 nm is the largest. It is preferable to use active energy rays. When a transparent protective film (ultraviolet opaque transparent protective film) having an ultraviolet absorbing ability is used in terms of ultraviolet curability and visible light curability, it absorbs light having a wavelength shorter than about 380 nm, and therefore has a wavelength shorter than 380 nm. Light does not reach the adhesive composition and does not contribute to its polymerization reaction. Further, the 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 curl and wrinkles of the polarizing film. Therefore, when adopting ultraviolet curability and visible light curability in the present invention, it is preferable to use a device that does not emit light having a wavelength shorter than 380 nm as an active energy ray generator, and more specifically, a wavelength range of 380. The ratio of the integrated illuminance of about 440 nm to the integrated illuminance of the wavelength range of 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-filled metal halide lamp and an LED light source that emits light in a wavelength range of 380 to 440 nm are preferable. Alternatively, with ultraviolet rays such as 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, excima laser or sunlight. A light source containing visible light can be used, and a bandpass filter can be used to block ultraviolet rays having a wavelength shorter than 380 nm. In order to prevent curling of the polarizing film while improving the adhesive performance of the adhesive layer between the polarizing element and the transparent protective film, a gallium-filled metal halide lamp can be used and light having a wavelength shorter than 380 nm can be blocked. It is preferable to use an active energy ray obtained through a bandpass filter or an active energy ray having a wavelength of 405 nm obtained by using an LED light source.

When the polarizing film according to the present invention is produced in a continuous line, the line speed depends on the curing time of the adhesive composition, but is preferably 5 to 100 m / min, more preferably 10 to 50 m / min, and further preferably 20 to 20. It is 30 m / min. If 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 durability tests cannot be produced. If the line speed is too high, the adhesive composition may not be sufficiently cured and the desired adhesiveness may not be obtained.

The polarizing film of the present invention can be used as an optical film laminated with another optical layer in practical use. The optical layer is not particularly limited, but is used for forming, for example, a reflector, a transflective plate, a retardation plate (including a wave plate such as 1/2 or 1/4), a liquid crystal display device such as a viewing angle compensation film, and the like. One or more optical layers that may be used can be used. In particular, a reflective polarizing film or a semi-transmissive polarizing film in which a reflecting plate or a semi-transmissive reflecting plate is further laminated on the polarizing film of the present invention, an elliptically polarizing film or a circularly polarized light in which a retardation plate is further laminated on the polarizing film. A wide viewing angle polarizing film in which a viewing angle compensating film is further laminated on a film or a polarizing film, or a polarizing film in which a brightness improving film is further laminated on a polarizing film is preferable.

An optical film in which the above optical layer is laminated on a polarizing film can also be formed by a method in which the optical film is sequentially and separately laminated in a manufacturing process such as a liquid crystal display device. It is excellent in stability and assembly work, and has the advantage of improving the manufacturing process of liquid crystal display devices and the like. An appropriate adhesive means such as an adhesive layer may be used for laminating. When adhering the above-mentioned polarizing film or other optical film, the optical axes thereof can be set to an appropriate arrangement angle according to a target phase difference characteristic or the like.

An adhesive layer for adhering to another member such as a liquid crystal cell may be provided on the above-mentioned polarizing film or an optical film in which at least one polarizing film is laminated. The pressure-sensitive adhesive that forms the pressure-sensitive adhesive layer is not particularly limited, and for example, an acrylic polymer, a silicone-based polymer, polyester, polyurethane, a polyamide, a polyether, a fluoropolymer, a rubber-based polymer, or the like as a base polymer is appropriately selected. Can be used. In particular, an acrylic pressure-sensitive adhesive that has excellent optical transparency, exhibits appropriate wettability, cohesiveness, and adhesiveness, and has excellent weather resistance and heat resistance can be preferably used.

The adhesive layer can also be provided on one or both sides of a polarizing film or an optical film as a superimposing layer of different compositions or types. Further, when provided on both sides, adhesive layers having different compositions, types and thicknesses can be formed on the front and back sides of the polarizing film or the optical film. The thickness of the adhesive layer can be appropriately determined depending on the purpose of use, adhesive strength, etc., and is generally 1 to 100 μm, preferably 5 to 30 μm, and particularly preferably 10 to 20 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. This makes it possible to prevent the adhesive layer from coming into contact with the adhesive layer under normal handling conditions. Except for the above thickness conditions, the separator may be a suitable thin leaf such as a plastic film, rubber sheet, paper, cloth, non-woven fabric, net, foam sheet or metal leaf, or a laminate thereof, and if necessary, a silicone-based or long material. Appropriate conventional ones such as those coated with an appropriate release agent such as chain alkyl type, fluorine type and molybdenum sulfide can be used.

In the present invention, various laminated optical films can be manufactured by arbitrarily combining functional films such as the above-mentioned transparent protective film, polarizing element, and luminance improving film. An example of these is shown below.

(Pattern 1)
A polarizing film in which a transparent protective film is laminated on one surface of a polarizing element via an adhesive layer formed by curing the adhesive composition, which is between the transparent protective film and the adhesive layer. In addition, a polarizing film having a compatible layer in which these compositions change continuously. An easy-adhesive layer containing at least the compound represented by the general formula (6) may be formed on the surface of the polarizing element on the adhesive layer side.

(Pattern 2)
A polarizing film in which a transparent protective film is laminated on both sides of a polarizing element via an adhesive layer formed by curing an adhesive composition, which comprises at least one of the transparent protective film and the adhesive layer. A polarizing film in which a compatible layer in which these compositions change continuously is formed. An easy-adhesive layer containing at least the compound represented by the general formula (6) may be formed on the surface of the polarizing element on the adhesive layer side. Further, an adhesive layer may be laminated on the surface of the transparent protective film opposite to the adhesive layer.

(Pattern 3)
A transparent protective film is laminated on one surface of the polarizing element via an adhesive layer formed by curing the adhesive composition, and a pressure-sensitive adhesive layer is laminated on the other surface of the polarizing element. A polarizing film, which is a film in which a compatible layer in which these compositions continuously change is formed between a transparent protective film and an adhesive layer. An easy-adhesive layer containing at least the compound represented by the general formula (6) may be formed on the surface of the polarizing element on the adhesive layer side. Further, a functional film may be laminated on the surface of the pressure-sensitive adhesive layer opposite to the polarizing element, and the pressure-sensitive adhesive layer may be laminated on the surface of the transparent protective film opposite to the adhesive layer.

(Pattern 4)
A laminated optical film in which at least two transparent protective films are laminated via an adhesive layer, and a phase in which these compositions continuously change between the at least one transparent protective film and the adhesive layer. A laminated optical film on which a molten layer is formed. The transparent protective film to be laminated may be the same type of transparent protective film or different types of transparent optical film. Further, an adhesive layer may be laminated on the surface of the transparent protective film opposite to the adhesive layer.

(Pattern 5)
A polarizing film in which a transparent protective film is laminated on both sides of a polarizing element via an adhesive layer formed by curing an adhesive composition, which comprises at least one of the transparent protective film and the adhesive layer. A compatible layer in which these compositions change continuously is formed between them, and a transparent protective film is further laminated on the surface of at least one of the transparent protective films opposite to the adhesive layer via the adhesive layer. Polarizing film. An adhesive layer may be laminated on the surface of the transparent protective film located on the outermost side opposite to the adhesive layer.

(Pattern 6)
A transparent protective film is laminated on one surface of the polarizing element via an adhesive layer formed by curing the adhesive composition, and adhered to the surface of the transparent protective film opposite to the adhesive layer. A polarizing film in which a transparent protective film is further laminated via an agent layer, and a functional film is laminated on the other surface of the polarizing element via an adhesive layer, and is a polarizing film in which at least one transparent protective film and an adhesive layer are laminated. A polarizing film in which a compatible layer in which these compositions change continuously is formed. A functional film may be laminated on the surface of the pressure-sensitive adhesive layer opposite to the polarizing element, and the pressure-sensitive adhesive layer may be laminated on the surface of the transparent protective film opposite to the adhesive layer.

The polarizing film or 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 in the same manner as before. That is, the liquid crystal display device is generally formed by appropriately assembling a liquid crystal cell, a polarizing film or an optical film, and if necessary, components such as a lighting system, and incorporating a drive circuit. There is no particular limitation except that the polarizing film or the optical film according to the invention is used, and the conventional method can be applied. As the liquid crystal cell, any type such as TN type, STN type, and π type can be used.

It is possible to form an appropriate liquid crystal display device such as a liquid crystal display device in which a polarizing film or an optical film is arranged on one side or both sides of the liquid crystal cell, or a lighting system using a backlight or a reflector. In that case, the polarizing film or the optical film according to the present invention can be installed on one side or both sides of the liquid crystal cell. When polarizing films or optical films are provided on both sides, they may be the same or different. Further, when forming the liquid crystal display device, for example, an appropriate component such as a diffuser plate, an anti-glare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffuser plate, and a backlight is placed in one layer or at an appropriate position. 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.

In the present invention, the SP value and the SP value distance are determined by the following method.

<Method of estimating SP value of active energy ray-curable adhesive composition>
For the SP value of the active energy ray-curable adhesive composition, the solubility parameter (SP value) of Hansen was calculated by the Y-MB method of Hansen Solubility Parameter in Practice (HSPiP) for each of the constituent materials of the composition, and the solubility parameter (SP value) was calculated in the composition. It was obtained by taking the average value according to the molar ratio of.

<Method of estimating SP value of organic solvent>
The SP value of the organic solvent is described in Hansen Solubility Parameter in Practice (HSPiP) ver. The official value was obtained from the Hansen solubility parameter (SP value) database stored in 4.1.07. When two or more kinds of organic solvents were mixed and used, the average value was taken according to the molar ratio.

<Method of measuring SP value of transparent protective film>
A transparent protective film is used for 14 solvents with different solubilities, water, acetone, cyclopentanone, isopropyl alcohol, ethanol, methanol, toluene, p-xylene, cyclohexane, n-hexane, ethyl acetate, trichlorobenzene, anisole and theirs. It was immersed in the mixed solvent for 10 minutes. The state of the transparent protective film after soaking for 10 minutes was classified into three stages: (1) dissolution, (2) swelling, and (3) insoluble. Based on the information on the solubility in each solvent thus obtained, Hansen Solubility Parameter in Practice (HSPiP) ver. The solubility parameter (SP value) of Hansen was calculated by 4.1.07 (http://www.hansen-solubility.com/index.php).

<SP value distance (Ra-1) between the SP value of the transparent protective film and the SP value of the adhesive composition>
The dispersion term of Hansen's solubility parameter of the transparent protective film is σd, the polarity term is σp, the hydrogen bond term is σh, the dispersion term of Hansen's solubility parameter of the active energy ray-curable adhesive composition is σAd, and the polarity term is σAp. , When the hydrogen bond term is σAh, the following formula;
Ra-1 = [4 × (σd-σAd) ² + 2 × (σp-σAp) ² + 2 × (σh-σAh) ² ] ^1/2
Was defined as the "SP value distance between the SP value of the transparent protective film and the SP value of the adhesive composition" (= Ra-1). It was calculated using the Hansen solubility parameter of the transparent protective film and the active energy ray-curable adhesive composition calculated by the above method.

<SP value distance Ra-2 between the SP value of the transparent protective film and the SP value of the organic solvent>
The dispersion term of the Hansen solubility parameter of the transparent protective film is σd, the polarity term is σp, the hydrogen bond term is σh, the dispersion term of the Hansen solubility parameter of the organic solvent is σBd, the polarity term is σBp, and the hydrogen bond term is σBh. When you do, the following formula;
Ra-2 = [4 × (σd-σBd) ² + 2 × (σp-σBp) ² + 2 × (σh-σBh) ² ] ^1/2
Was defined as the "SP value distance between the SP value of the transparent protective film and the SP value of the organic solvent" (= Ra-2). It was calculated using the transparency parameter of Hansen of the transparent protective film and the organic solvent calculated by the above method.

In the present invention, a compatible layer in which these layers are continuously changed (in Tables 1 to 8, simply referred to as “compatible layer”) is formed between the transparent protective film and the adhesive layer. The following method was used to determine whether or not it was present.

<Confirmation of compatible layer>
In order to observe the cross section of the film, a test piece prepared by the ultrathin section method was observed with a transmission electron microscope (TEM) (manufactured by Hitachi, Ltd., product name "H-7650") at an acceleration voltage of 100 kV. A TEM photograph was taken. The case where the compatible layer was formed was defined as "yes", and the case where the compatible layer was not formed was defined as "absent".

Examples 1-1 to 1-9 and Comparative Examples 1-1 to 1-6
<Making a polarizing element>
A polyvinyl alcohol film having an average degree of polymerization of 2400 and a saponification degree of 99.9 mol% and a thickness of 45 μm was immersed in warm water at 30 ° C. for 60 seconds to swell. Then, the film was dyed by immersing it in an aqueous solution having a concentration of iodine / potassium iodide (weight ratio = 0.5 / 8) at a concentration of 0.3% and stretching it up to 3.5 times. Then, stretching was carried out in a boric acid ester aqueous solution at 65 ° C. so that the total stretching ratio was 6 times. After stretching, it was dried in an oven at 40 ° C. for 3 minutes to obtain a polyvinyl alcohol-based polarizing element X (thickness 18 μm). Next, using a wire bar (manufactured by Daiichi Rika Co., Ltd., No. 2), an easy-adhesive composition containing 1% by weight of 4-vinylphenylboronic acid and 99% by weight of isopropyl alcohol on both sides of the polarizing element X. Was applied and air-dried at 60 ° C. for 1 minute to remove the solvent to prepare a Boronic acid with an easy-adhesive layer having a thickness of 1 nm after drying of the easy-adhesive layer.

<Transparent protective film 1>
In a reaction vessel equipped with a stirrer, 2.70 kg of 2,2-bis (4-hydroxyphenyl) -4-methylpentane and 0.06 kg of tetrabutylammonium chloride were dissolved in 25 L of 1 M sodium hydroxide solution. A solution prepared by dissolving 1.22 kg of terephthalic acid chloride and 0.81 kg of isophthalic acid chloride in 30 L of toluene was added to this solution with stirring, and the mixture was stirred at room temperature for 90 minutes. Then, the polymerization solution was statically separated to separate the toluene solution containing the polymer, then washed with acetic acid water, washed with ion-exchanged water, and then poured into methanol to precipitate the polymer. The precipitated polymer was filtered and dried under reduced pressure to obtain 3.41 kg (yield 92%) of a white polymer.

The obtained polymer was dissolved in toluene, coated on biaxially stretched polypropylene, dried at 80 ° C. for 5 minutes, and then dried at 110 ° C. for 5 minutes to prepare a laminated film having a coating film of 15 μm. The obtained laminated film is stretched 1.2 times in the width direction at 145 ° C. while being conveyed using a simultaneous biaxial stretching machine, and is shrunk to MD 0.75 times to form a roll. A polyarylate-based transparent protective film 1 was obtained. The obtained transparent protective film 1 had a thickness of 15.0 μm, Re = 275 nm, Rth = 138 nm, and Nz coefficient = 0.5.

A wire bar (manufactured by Daiichi Rika Co., Ltd., No. 3) is used on the surface of the transparent protective film 1 on the side where the adhesive layer is formed, and the SP value distance from the transparent protective film 1 is Ra shown in Table 1. A pretreatment was performed by applying an organic solvent having a composition of -1. Next, on the contact surface of the transparent protective film 1 with the organic solvent, an adhesive composition having a composition such that the SP value distance from the transparent protective film 1 is Ra-2 shown in Table 1 is applied to the MCD coater (Fuji). (Made by Machinery Co., Ltd.) (Cell shape: Honeycomb, Number of gravure roll lines: 1000 lines / inch, Rotation speed 140% / Anti-line speed) is used to apply a coating to a thickness of 1 μm on both sides of the polarizing element X. It was pasted together with a roll machine. Then, the visible light was irradiated on both sides of the bonded transparent protective film 1 side (both sides) with an active energy ray irradiator to cure the curable adhesive, and then dried with hot air at 70 ° C. for 3 minutes. A polarizing film having a transparent protective film 1 on both sides of the polarizing element was obtained. The bonding line speed was 25 m / min.

The adhesiveness of the obtained polarizing film was evaluated by the following method.

<Initial adhesive strength>
The polarizing film was cut into a size of 200 mm parallel to the stretching direction of the polarizing element and 15 mm in the orthogonal direction, and the polarizing film was bonded to a glass plate. Then, a notch is made between the transparent protective film and the polarizing element with a cutter knife, and the protective film and the polarizing element are peeled off in the 90-degree direction at a peeling speed of 300 mm / min with Tencilon to increase the peeling strength (N / 15 mm). It was measured. In addition, the infrared absorption spectrum of the peeled surface after peeling was measured by the ATR method, and the peeling morphology was evaluated based on the following criteria. The results are shown in Table 1-8. In Table 1-8, the case where the peel strength is described as "break" means that the base material is broken when the peel strength is measured because the adhesive strength is superior to the break strength of the base material. ..
〇: When the material of the transparent protective film is destroyed or when the material of the polarizing element is destroyed △: When the material of the transparent protective film is destroyed and the interface peeling between the transparent protective film and the adhesive layer is mixed, or the material of the polarizing element When the breakage and the interfacial peeling between the decoder and the adhesive layer are mixed ×: When the transparent protective film and the adhesive interlayer are interfacially peeled, or when the substituent and the adhesive interlayer are interfacially peeled.

<Adhesive force after 85 ° C. 85RH-48h> A polarizing film is cut into a size of 200 mm parallel to the stretching direction of the polarizing element and 15 mm in the orthogonal direction, and the polarizing film is bonded to a glass plate under an environment of 85 ° C. and 85% RH. Was exposed for 48 hours. After that, the same evaluation as in the initial adhesive strength evaluation was performed, and the peel strength and the peeling morphology were evaluated. The results are shown in Table 1.

Examples 2-1 to 2-12- and Comparative Examples 2-1 to 2-8
A polarizing film was produced and evaluated by the same method as in Example 1 except that the transparent protective film was changed to the polycarbonate shown below and the organic solvent and the adhesive composition were changed to those shown in Table 2.

<Transparent protective film 2>
Polymerization was carried out using a batch polymerization apparatus consisting of two vertical reactors equipped with a stirring blade and a reflux condenser controlled at 100 ° C. Bis [9- (2-phenoxycarbonylethyl) fluoren-9-yl] 29.60 parts by mass (0.046 mol) of methane, 29.21 parts by mass (0.200 mol) of ISB, 42.28 parts by mass of SPG (0. 139 mol), 63.77 parts by mass (0.298 mol) of DPC and 1.19 × 10-2 parts by mass (6.78 × 10-5 mol) of calcium acetate monohydrate were charged as a catalyst. After substituting nitrogen under reduced pressure in the reactor, heating was performed with a heat medium, and stirring was started when the internal temperature reached 100 ° C. The internal temperature was brought to 220 ° C. 40 minutes after the start of the temperature rise, and the depressurization was started at the same time as controlling to maintain this temperature, and the temperature was 13.3 kPa 90 minutes after reaching 220 ° C. The phenol vapor produced by the polymerization reaction was guided to a reflux condenser at 100 ° C., the monomer component contained in a small amount in the phenol vapor was returned to the reactor, and the non-condensed phenol vapor was guided to a condenser at 45 ° C. for recovery. Nitrogen was introduced into the first reactor and the pressure was once restored to atmospheric pressure, and then the oligomerized reaction solution in the first reactor was transferred to the second reactor. Then, the temperature rise and depressurization in the second reactor were started, and the internal temperature was 240 ° C. and the pressure was 0.2 kPa in 50 minutes. Then, the polymerization was allowed to proceed until the predetermined stirring power was obtained. When the predetermined power was reached, nitrogen was introduced into the reactor to repressurize, the produced polyester carbonate was extruded into water, and the strands were cut to obtain pellets.

After vacuum-drying the obtained polycarbonate resin at 80 ° C. for 5 hours, a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder set temperature: 250 ° C.), T-die (width 200 mm, set temperature: 250 ° C.), chill roll ( A resin film having a thickness of 135 μm was produced using a film-forming device equipped with a set temperature (120 to 130 ° C.) and a winder.

The obtained elongated resin film is stretched in the width direction at a stretching temperature of 134 ° C. and a stretching ratio of 2.8 times, and subsequently subjected to relaxation treatment in the width direction of the stretched film to obtain a stretched film. Was produced. The conditions for the relaxation treatment were a relaxation temperature of 130 ° C. and a relaxation rate of 4.5%. A polycarbonate-based transparent protective film 2 having a thickness of 48 μm was obtained.

Examples 3-1 to 3-11 and Comparative Examples 3-1 to 3-3
A polarizing film was produced and evaluated by the same method as in Example 1 except that the transparent protective film was changed to the acrylic shown below and the organic solvent and the adhesive composition were changed to those shown in Table 3.

<Transparent protective film 3>
Transparent protective film A (containing glutarimide unit): MS resin (MS-200; copolymer of methyl methacrylate / styrene (molar ratio) = 80/20, manufactured by Nippon Steel Chemical Co., Ltd.) is imide with monomethylamine. (Imidization rate: 5%). The obtained imidized MS resin is a glutarimide unit represented by the general formula (1) described in JP-A-2016-139027 (in the formula, R ¹ and R ³ are methyl groups, and R ² is a hydrogen atom. Yes), the (meth) acrylic acid ester unit represented by the general formula (2) described in JP-A ^{- 2016-139027} ( ^R4 is a hydrogen atom, R5 and R6 are methyl groups), and a styrene unit. Have. For the imidization, a meshing type co-rotating twin-screw extruder having a diameter of 15 mm was used. The set temperature of each temperature control zone of the extruder was 230 ° C., the screw rotation speed was 150 rpm, the MS resin was supplied at 2.0 kg / hr, and the amount of monomethylamine supplied was 2 parts by weight with respect to 100 parts by weight of the MS resin. .. The MS resin was charged from the hopper, the resin was melted and filled with the kneading block, and then monomethylamine was injected from the nozzle. A seal ring was placed at the end of the reaction zone to fill the resin. The by-products and excess methylamine after the reaction were devolatile by reducing the pressure at the vent port to −0.08 MPa. The resin that came out as a strand from the die provided at the outlet of the extruder was cooled in a water tank and then pelletized with a pelletizer. The imidized MS resin was melt-extruded to form a film. At this time, an ultraviolet absorber (manufactured by ADEKA, "T-712") was supplied in an amount of 0.66 parts by weight based on 100 parts by weight of the MS resin. Next, an acrylic transparent protective film 3 (thickness 40 μm, Re = 2 nm, Rth = 2 nm) was biaxially stretched twice in length and twice in width.

Examples 4-1 to 4-7 and Comparative Examples 4-1 to 4-8
A polarizing film is produced by the same method as in Example 1 except that the transparent protective film is changed to the triacetyl cellulose (TAC) shown below and the organic solvent and the adhesive composition are changed to those shown in Table 4. And evaluated.

<Transparent protective film 2>
Triacetyl cellulose film with a thickness of 60 um Product name: TG60UL Fujifilm Co., Ltd.

Examples 5-1 to 5-4 and Comparative Example 5-1
A polarizing film was produced and evaluated by the same method as in Example 1 except that the pretreatment for applying the organic solvent was not performed.

Examples 6-1 to 6-6 and Comparative Examples 6-1 to 6-2
A polarizing film was produced and evaluated by the same method as in Example 2 except that the pretreatment for applying the organic solvent was not performed.

Examples 7-1 to 7-3 and Comparative Example 7-1
A polarizing film was produced and evaluated by the same method as in Example 3 except that the pretreatment for applying the organic solvent was not performed.

Examples 8-1 to 8-7 and Comparative Example 8-1
A polarizing film was produced and evaluated by the same method as in Example 4 except that the pretreatment for applying the organic solvent was not performed.

In Tables 1 to 8, the compounds used as the adhesive composition are shown below.
HEAA; hydroxyethyl acrylamide (manufactured by Kojinsha)
DEAA; diethyl acrylamide (manufactured by Kojinsha)
19ND-A; 1,9-nonanediol diacrylate (trade name "Light Acrylate 1,9ND-A", manufactured by Kyoeisha Chemical Co., Ltd.)
HPAA; hydroxypivalate didiacrylate (trade name: Light Acrylate HPPA, manufactured by Kyoeisha Chemical Co., Ltd.)
DCP-A; Dimethylol-tricyclodecanediacrylate (trade name "Light Acrylate DCP-A, manufactured by Kyoeisha Chemical Co., Ltd.)"
M-220; Tripropylene glycol diacrylate (trade name "Aronix M-220", NP-A manufactured by Toagosei Co., Ltd .; Neopentyl glycol diacrylate (trade name "Light acrylate NP-A", manufactured by Kyoeisha Chemical Co., Ltd.))
ACMO: Acryloyl morpholine (manufactured by Kojinsha)
Wasmer 2MA; N-Methoxymethylacrylamide (trade name "Wasmer 2MA", manufactured by Kasano Kosan Co., Ltd.)
NVP; N-vinylpyrrolidone (trade name "NVP", manufactured by Nippon Shokubai Co., Ltd.)
IB-XA; Isobornyl acrylate (trade name "Light Acrylate IB-XA", manufactured by Kyoeisha Chemical Co., Ltd.)
GBLA; γ-butyrolactone acrylate (trade name "GBLA", manufactured by Osaka Organic Chemical Industry Co., Ltd.)
M5700; 2-Hydroxy-3-phenoxypropyl acrylate (trade name: Aronix M5700, manufactured by Toagosei Co., Ltd.)
APG100; Dipropylene glycol diacrylate (trade name APG100, manufactured by Shin-Nakamura Chemical Co., Ltd.)
AAEA; 2-acetoacetoxyethyl acrylate (trade name AAEA, manufactured by Nippon Synthetic Chemistry Co., Ltd.)
ISTA; Isostearyl acrylate (trade name ISTA, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
Celoxide 2021P; 3', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: Celoxide 2021P, manufactured by Daicel)
FA513AS; Dicyclopentanyl acrylate (trade name: Funkryl FA513AS, manufactured by Hitachi Kasei Co., Ltd.)
GBL; γ-Butyrolactone (manufactured by Mitsubishi Chemical Corporation)
Propylene carbonate (manufactured by Tokyo Chemical Industry Co., Ltd.)
Anisole (manufactured by Tokyo Chemical Industry Co., Ltd.)

Claims (5)

A laminated optical film in which a transparent protective film is laminated on at least one surface of the optical film via an adhesive layer formed by curing the adhesive composition.
The skin layer of the transparent protective film has been eliminated,
A compatible layer in which these compositions continuously change is formed between the transparent protective film from which the skin layer has been eliminated and the adhesive layer.
A laminated optical film, characterized in that the SP value distance between the SP value of the transparent protective film and the SP value of the adhesive composition is 12 or less. The laminated optical film according to claim 1, wherein the adhesive composition is an active energy ray-curable adhesive composition containing a monomer having a polymerizable group. The laminated optical film according to claim 1 or 2 , wherein the optical film is a polyvinyl alcohol-based polarizing element. The laminated optical film according to any one of claims 1 to 3 , wherein the transparent protective film is at least one thermoplastic resin selected from the group consisting of polyarylate, polycarbonate, acrylic polymer and triacetyl cellulose. An image display device according to any one of claims 1 to 4 , wherein the laminated optical film is used.