TW202114869A - Method for manufacturing polarizing film capable of suppressing the generation of bubbles in a polarizing film while improving the adhesion between a polarizing element and a transparent protective film - Google Patents

Abstract

The present invention provides a method for manufacturing a polarizing film. The method includes a first applying step of applying an adhesive composition to a binding face of a transparent protective film; a second applying step of applying an easy-adhesive composition to a binding face of a polarizing element; a bonding step of bonding the polarizing element with the transparent protective film; and an adhering step of irradiating active energy rays from the surface side of the polarizing element or the surface side of the transparent protective film to cure the adhesive composition and the easy-adhesive composition to obtain an adhesive layer so as to adhere the polarizing element to the transparent protective film through the adhesive layer disposed therebetween. An SP value distance between an SP value of the transparent protective film and an SP value of the adhesive composition is 5.3 or more, and the SP value distance between an average SP value calculated based on a volume ratio of the SP value of the adhesive composition and the SP value of the easy-adhesive composition and the SP value of the transparent protective film is 5.8 or less.

Description

Manufacturing method of polarizing film

Invention field

The present invention relates to a method for manufacturing a polarizing film in which a transparent protective film is provided on at least one side of a polarizer via an adhesive layer. The polarizing film may be used alone or in the form of an optical film laminated with the polarizing film to form an image display device such as a liquid crystal display device (LCD), an organic EL display device, a CRT, or a PDP.

Background of the invention

Among clocks, mobile phones, PDAs, notebook computers, computer monitors, DVD players, TVs, etc., liquid crystal display devices are rapidly opening up the market. A liquid crystal display device is a device that visualizes the polarization state of a switch based on a liquid crystal, and based on its display principle, a polarizer is used. Especially in TV applications, high brightness, high contrast, and wide viewing angle are increasingly required, and polarizing films are also increasingly required to have high transmittance, high degree of polarization, and high color reproducibility.

As a polarizer, from the viewpoint of having high transmittance and high degree of polarization, for example, iodine having a structure in which iodine is adsorbed on polyvinyl alcohol (hereinafter, also referred to as "PVA") and stretched is most widely used. Department of polarizing parts. Generally, a polarizing film is used in which a transparent protective film is bonded to both sides of a polarizer using a so-called aqueous adhesive made by dissolving a polyvinyl alcohol-based material in water (Patent Document 1 below). As the transparent protective film, cellulose triacetate with high moisture permeability or the like is used. When the above-mentioned aqueous adhesive (so-called wet lamination) is used, a drying step is required after bonding the polarizer and the transparent protective film.

On the other hand, instead of the above-mentioned water-based adhesive, an active energy ray-curable adhesive has been proposed. In the case of manufacturing a polarizing film using an active energy ray-curable adhesive, since a drying step is not required, the productivity of the polarizing film can be improved. For example, a radical polymerization type active energy ray-curable adhesive using an N-substituted amine-based monomer as a curable component has been proposed (Patent Document 2 below). Advanced technical literature Patent literature

Patent Document 1: Japanese Patent Application Publication No. 2001-296427 Patent Document 2: JP 2012-052000 A

Summary of the invention The problem to be solved by the invention

The adhesive layer formed using the active energy ray-curable adhesive described in Patent Document 2 can sufficiently withstand a water resistance test that evaluates the presence or absence of discoloration and peeling after immersing in 60°C warm water for 6 hours, for example. However, in recent years, adhesives for polarizing films are required to be able to withstand a more severe water resistance test, such as the degree of resistance to peeling when the end claws are peeled off after being immersed (saturated) in water. . Therefore, the current situation is that, including the polarizing film using the active energy ray-curable adhesive described in Patent Document 2, the adhesives for polarizing films reported so far have further improved adhesion. room.

In addition, in recent years, the thinning of the polarizing film is progressing. If bubbles or the like are present in the polarizing film, it is likely to be noticeable as an appearance defect, and it is often a product defect. Therefore, for example, it is indispensable to suppress the generation of air bubbles on the surface of the transparent protective film constituting the polarizing film or the adhesive layer for bonding the transparent protective film and the polarizer. However, the actual situation is that there is no report example for optimizing the affinity between the transparent protective film and the adhesive layer and suppressing the generation of bubbles in the polarizing film.

The present invention was developed in view of the above-mentioned actual situation, and its object is to provide a method for manufacturing a polarizing film that can improve the adhesion between the polarizer and the transparent protective film while suppressing the generation of bubbles in the polarizing film. Means to solve the problem

The above-mentioned problem can be solved by the following configuration. That is, the present invention relates to a method of manufacturing a polarizing film, wherein the polarizing film is provided with a transparent protective film on at least one surface of the polarizing member via an adhesive layer. The method includes: a first coating step, attaching the transparent protective film to The bonding surface is coated with an adhesive composition; the second coating step is to coat the easy-adhesive composition on the bonding surface of the polarizer; the bonding step is to bond the polarizer and the transparent protective film; and In the bonding step, active energy rays are irradiated from the side of the polarizer surface or the surface of the transparent protective film to cure the adhesive composition and the easy-adhesive composition to obtain an adhesive layer, so that the adhesive layer is interposed. The polarizer and the transparent protective film are bonded together, and the SP value distance between the SP value of the transparent protective film and the SP value of the adhesive composition is 5.3 or more, and is based on the SP value of the adhesive composition and The SP value distance between the calculated average SP value and the SP value of the transparent protective film by the volume ratio of each of the SP values of the easily-adhesive composition is 5.8 or less.

(式中，X為包含反應性基團的官能團，R¹ 及R² 分別獨立地表示氫原子、可亦具有取代基的脂肪族烴基、芳基或雜環基。X所含的反應性基團為選自於由乙烯基、(甲基)丙烯醯基、苯乙烯基、(甲基)丙烯醯胺基、乙烯基醚基、環氧基、氧雜環丁基及巰基所構成組群中的至少1種反應性基團)。Preferably, in the manufacturing method of the above-mentioned polarizing film, the above-mentioned easy-adhesive composition contains a compound represented by the following general formula (1), [Chemical formula 1]

(In the formula, X is a functional group containing a reactive group, and R ¹ and R ² each independently represent a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, or a heterocyclic group which may also have a substituent. The reactive group contained in X The group is selected from the group consisting of vinyl, (meth)acryloyl, styryl, (meth)acrylamido, vinyl ether, epoxy, oxetanyl and mercapto groups At least one reactive group in).

(式中，Y為有機基團，X’為X所含的反應性基團，R¹ 及R² 與上述定義相同)。Preferably, in the manufacturing method of the above-mentioned polarizing film, the compound represented by the above general formula (1) is a compound represented by the following general formula (1'), [Chemical formula 2]

(In the formula, Y is an organic group, X'is a reactive group contained in X, and R ¹ and R ² are the same as defined above).

(式中，R³ 為氫原子或甲基，R⁴ 及R⁵ 分別獨立地為氫原子、烷基、羥基烷基、烷氧基烷基或環狀醚基，R⁴ 及R⁵ 可亦形成環狀雜環)。 發明的效果Preferably, in the manufacturing method of the above-mentioned polarizing film, the above-mentioned easy-adhesive composition contains a radical polymerizable compound represented by the following general formula (2), [Chemical formula 3]

(In the formula, R ³ is a hydrogen atom or a methyl group, R ⁴ and R ⁵ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group, or a cyclic ether group. R ⁴ and R ⁵ may also be To form a cyclic heterocyclic ring). The effect of the invention

In the manufacturing method of the polarizing film of the present invention, the adhesive composition for bonding the polarizer and the transparent protective film is applied to the bonding surface of the transparent protective film (the bonding surface with the polarizing member) (Section One coating step). In the present invention, in the first coating step, the lamination applied to the transparent protective film is designed so that the SP value distance between the SP value of the transparent protective film and the SP value of the adhesive composition becomes 5.3 or more Surface adhesive composition. As a result, it is possible to manufacture a polarizing film that suppresses the generation of bubbles on the surface of the transparent protective film and/or in the adhesive layer. In the manufacturing method of the polarizing film of the present invention, the reason for obtaining the above-mentioned effects can be estimated as follows.

In order to improve the adhesive force between the adhesive and the adherend, an adhesive with excellent affinity with the adherend is usually selected. However, the inventors of the present application found that when producing a polarizing film based on such general knowledge, bubbles are likely to be generated in the polarizing film due to the following phenomenon. (1) When selecting an adhesive composition that has excessively excellent affinity for the transparent protective film, the adhesive composition excessively penetrates into the transparent protective film, and the surface of the transparent protective film (the coated surface of the adhesive composition) becomes dry status. (2) Since irregularities remain on the surface of the transparent protective film in a dry state, the surface roughness Ra becomes high. (3) Due to the unevenness remaining on the surface of the transparent protective film, air bubbles are generated in the laminated polarizing film.

In order to avoid the above phenomenon, in the present invention, in order to prevent the adhesive composition from penetrating excessively into the transparent protective film, the adhesive composition is used to fill the unevenness remaining on the surface of the transparent protective film to make the surface smooth, and the design is as follows Adhesive composition: moderately reduce the affinity between the transparent protective film and the adhesive composition used, specifically, make the SP value distance between the SP value of the transparent protective film and the SP value of the adhesive composition 5.3 the above. Thus, in the present invention, it is possible to manufacture a polarizing film in which the generation of bubbles on the surface of the transparent protective film and/or in the adhesive layer can be produced.

Furthermore, in the present invention, when manufacturing the polarizing film, it is not only necessary to suppress the generation of bubbles on the surface of the transparent protective film and/or in the adhesive layer, but also to take into account the adhesion between the polarizer and the transparent protective film, but In this regard, the distance between the average SP value calculated based on the volume ratio of the SP value of the adhesive composition and the SP value of the easy-adhesive composition and the SP value of the transparent protective film can be designed to be 5.8 The following is achieved. The reason can be presumed as follows.

As described above, in order to increase the adhesive force between the adhesive composition and the transparent protective film, when an adhesive composition having excellent affinity for the transparent protective film is selected, the possibility of air bubbles is increased. In the present invention, in order to suppress the generation of bubbles, the adhesive composition is designed such that the SP value distance between the SP value of the transparent protective film and the SP value of the adhesive composition becomes 5.3 or more, and the adhesive composition The bonding surface is coated with the easy-adhesive composition (second coating step). In this case, in the bonding step, the uncured adhesive composition applied to the bonding surface of the transparent protective film and the uncured easy bonding composition applied to the bonding surface of the polarizer are mixed , And the SP value distance between the average SP value calculated based on the SP value of the adhesive composition and the SP value of the easy-adhesive composition after mixing and the SP value of the transparent protective film is 5.8 or less It can be designed to ensure the adhesion between the cured adhesive layer and the transparent protective film, and suppress the generation of bubbles on the surface of the transparent protective film and/or in the adhesive layer.

It should be noted that in the present invention, the SP value represents the meaning of 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 (such as a transparent protective film and an adhesive composition) can be evaluated by the distance of the two SP values (SP value distance). If the SP value distance between the two substances is small, it can be said to be affinity Sex.

As described above, in the manufacturing method of the polarizing film of the present invention, it is possible to manufacture a polarizing film that has improved adhesion between the polarizer and the transparent protective film and suppressed the generation of bubbles in the polarizing film. Therefore, the image display device using the polarizing film of the present invention is particularly useful in applications requiring adhesiveness and appearance.

The form used to implement the invention

The manufacturing method of the polarizing film of the present invention has: a first coating step, coating the adhesive composition on the bonding surface of the transparent protective film; and a second coating step, coating easy bonding on the bonding surface of the polarizer Composition; bonding step, bonding the polarizer and the transparent protective film; and bonding step, irradiating active energy rays from the side of the polarizer or the transparent protective film to make the adhesive composition and the easy-to-bond composition After curing to obtain an adhesive layer, the polarizer and the transparent protective film are adhered via the adhesive layer. Hereinafter, the present invention will be specifically described.

＜Adhesive composition＞ The adhesive composition used in the manufacturing method of the polarizing film of the present invention is designed so that the SP value distance between the SP value of the transparent protective film and the SP value of the adhesive composition becomes 5.3 or more. Regarding the upper limit of the SP value distance, in order to appropriately maintain the adhesive force between the transparent protective film and the adhesive layer, it is preferably 5.9 or less, more preferably 5.8 or less. It should be noted that in the present invention, the SP value of the monomers constituting the adhesive composition is used as a reference, and the SP value of the adhesive composition can be adjusted to a desired range by appropriately adjusting the mixing ratio, etc. Inside. The method for measuring the SP value of the adhesive composition will be described later.

The form in which the adhesive composition is cured can be roughly classified into thermal curing and active energy ray curing. Examples of resins constituting the thermosetting adhesive composition include polyvinyl alcohol resins, epoxy resins, unsaturated polyesters, urethane resins, acrylic resins, urea resins, melamine resins, phenol resins, etc. Combine curing agents as needed to use. As the resin constituting the thermosetting adhesive composition, polyvinyl alcohol resin and epoxy resin are more preferably used. As an active energy ray curable adhesive composition, classification based on active energy rays can be roughly classified into electron beam curability, ultraviolet curability, and visible light curability. In addition, as a form of curing, it can be classified into a radical polymerizable adhesive composition and a cation polymerizable adhesive composition. In the present invention, the active energy rays in the wavelength range of 10 nm to 380 nm can be described as ultraviolet rays, and the active energy rays in the wavelength range of 380 nm to 800 nm can be described as visible light.

In the production of the polarizing film of the present invention, the adhesive composition is preferably curable with active energy rays. Furthermore, it is particularly preferable that the visible light curability using visible light of 380 nm to 450 nm is used.

Examples of the curable component contained in the radically polymerizable adhesive composition include radically polymerizable compounds. Examples of the radical polymerizable compound include compounds having a radical polymerizable functional group having a carbon-carbon double bond such as a (meth)acryloyl group and a vinyl group. For these curable components, either a monofunctional radical polymerizable compound or a bifunctional or higher polyfunctional radical polymerizable compound can be used. Moreover, these radically polymerizable compounds may be used individually by 1 type or in combination of 2 or more types. As these radically polymerizable compounds, for example, compounds having a (meth)acryloyl group are preferred. In addition, in this invention, (meth)acryloyl group means an allyl group and/or a methacryloyl group, and "(methyl)" has the same meaning in the following.

(式中，R³ 氫原子或甲基，R⁴ 及R⁵ 分別獨立地為氫原子、烷基、羥基烷基、烷氧基烷基或環狀醚基，R⁴ 及R⁵ 可亦形成環狀雜環)。烷基、羥基烷基、及/或烷氧基烷基的烷基部分的碳原子數沒有特別限定，可示例出例如1~4個。另外，R⁴ 及R⁵ 可亦形成的環狀雜環可列舉例如N-丙烯醯基嗎啉等。Examples of the monofunctional radical polymerizable compound include compounds represented by the following general formula (2). [Chemical formula 4]

(In the formula, R ^{3 is a} hydrogen atom or a methyl group, R ⁴ and R ⁵ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group or a cyclic ether group. R ⁴ and R ⁵ may also form Cyclic heterocycle). The number of carbon atoms in the alkyl moiety of the alkyl group, hydroxyalkyl group, and/or alkoxyalkyl group is not particularly limited, and, for example, 1 to 4 can be exemplified. In addition, ^{examples of the cyclic heterocyclic ring that R 4} and R ⁵ may also form include N-acryloylmorpholine and the like.

As specific examples of the compound represented by the general formula (2), for example, N-methyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-bis Ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hexyl(meth)acrylamide, etc. Containing N-alkane (Meth)acrylamide derivatives; N-hydroxymethyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, N-hydroxymethyl-N-propyl(methyl) ) N-hydroxyalkyl (meth)acrylamide derivatives such as acrylamide; N-methoxymethacrylamide, N-ethoxymethacrylamide, etc. containing N-alkoxy ( (Meth)acrylamide derivatives and the like. In addition, examples of cyclic ether group-containing (meth)acrylamide derivatives include heterocyclic (meth)acrylamide derivatives in which the nitrogen atom of the (meth)acrylamide group forms a heterocyclic ring, such as N-acrylomorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, N-acryloylpyrrolidine, etc. can be mentioned. Among these, N-hydroxyethyl acrylamide and N-acrylamide can be suitably used from the aspect of excellent reactivity, the aspect of obtaining a cured product with high modulus of elasticity, and the aspect of excellent adhesion to the polarizer. Morpholine.

From the viewpoint of improving the adhesiveness and water resistance when the polarizer and the transparent protective film are bonded through the adhesive layer, the content of the compound described in the general formula (2) in the adhesive composition is higher It is preferably 0.01 to 80% by mass, more preferably 5 to 60% by mass.

In addition, in the adhesive composition used in the present invention, in addition to the compound represented by the general formula (2), another monofunctional radical polymerizable compound may be contained as a curable component. As a monofunctional radically polymerizable compound, various (meth)acrylic acid derivatives which have a (meth)acryloyloxy group are mentioned, for example. Specifically, examples include: methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, 2-methyl (meth)acrylate 2-nitropropyl ester, n-butyl (meth)acrylate, isobutyl (meth)acrylate, secondary butyl (meth)acrylate, tertiary butyl (meth)acrylate, (methyl) ) N-pentyl acrylate, tertiary pentyl (meth)acrylate, 3-pentyl (meth)acrylate, 2,2-dimethylbutyl (meth)acrylate, n-hexyl (meth)acrylate, ( Cetyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 4-methyl-2-propylpentyl (meth)acrylate, (meth)acrylate (Meth)acrylic acid (1-20 carbon atoms) alkyl esters such as n-octadecyl acrylate.

In addition, examples of the above-mentioned (meth)acrylic acid derivatives include (meth)acrylic acid cycloalkyl esters such as cyclohexyl (meth)acrylate and cyclopentyl (meth)acrylate; (meth)acrylic acid Benzyl esters and other (meth) aralkyl acrylates; 2-isobornyl (meth)acrylate, 2-norbornyl methyl (meth)acrylate, 2-norbornyl methyl (meth)acrylate, 5-norbornen-2-yl methyl (meth)acrylate, 3-methyl-2-norbornyl methyl (meth)acrylate, dicyclopentenyl (meth)acrylate, (meth) Polycyclic (meth)acrylates such as dicyclopentenyloxyethyl acrylate and dicyclopentyl (meth)acrylate; 2-methoxyethyl (meth)acrylate, 2-(meth)acrylate Ethoxyethyl, 2-methoxymethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth)acrylate, (methyl) ) Alkoxy or phenoxy-containing (meth)acrylates such as phenoxyethyl acrylate, alkylphenoxy polyethylene glycol (meth)acrylate, etc.; etc. Among these, dicyclopentenoxyethyl acrylate and phenoxyethyl acrylate are preferable in terms of excellent adhesion to various protective films.

In addition, examples of the above-mentioned (meth)acrylic acid derivatives include: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, Base) 2-hydroxybutyl acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxyl (meth)acrylate Decyl ester, 12-hydroxylauryl (meth)acrylate and other hydroxyalkyl (meth)acrylates, [4-(hydroxymethyl)cyclohexyl]methyl acrylate, cyclohexanedimethanol mono(meth)acrylic acid Ester, 2-hydroxy-3-phenoxypropyl (meth)acrylate and other hydroxyl-containing (meth)acrylates; glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidol Ether and other epoxy-containing (meth)acrylates; 2,2,2-trifluoroethyl (meth)acrylate, 2,2,2-trifluoroethylethyl (meth)acrylate, (methyl) ) Tetrafluoropropyl acrylate, hexafluoropropyl (meth)acrylate, octafluoropentyl (meth)acrylate, heptafluorodecyl (meth)acrylate, 3-chloro-2-hydroxyl (meth)acrylate Halogen-containing (meth)acrylates such as propyl ester; Alkylaminoalkyl (meth)acrylates such as dimethylaminoethyl (meth)acrylate; 3-oxetanyl methyl (meth)acrylate , 3-methyloxetanyl methyl (meth)acrylate, 3-ethyloxetanyl methyl (meth)acrylate, 3-butyloxetanyl methyl (meth)acrylate, (methyl) 3-hexyl oxetanyl methyl acrylate and other oxetanyl (meth)acrylates; tetrahydrofurfuryl (meth)acrylate, butyrolactone (meth)acrylates and other heterocyclic (methyl) ) Acrylate, hydroxypivalate neopentyl glycol (meth)acrylic acid adduct, p-phenylphenol (meth)acrylate, etc. Among these, 2-hydroxy-3-phenoxypropyl acrylate is preferable because of its excellent adhesion to various protective films.

In addition, examples of monofunctional radical polymerizable compounds include (meth)acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, etc. Carboxyl-containing monomers.

In addition, examples of monofunctional radical polymerizable compounds include endoamine-based vinyl monomers such as N-vinylpyrrolidone, N-vinyl-ε-caprolactone, and methyl vinylpyrrolidone; ethylene Vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piperazine, vinyl pyrazine, vinyl pyrrole, vinyl imidazole, vinyl oxazole, vinyl morpholine and other vinyls with nitrogen-containing heterocycles Monomers and so on.

The adhesive composition used in the present invention contains hydroxyl-containing (meth)acrylates, carboxyl-containing (meth)acrylates, and phosphoric acid-containing (meth) acrylates that have high polarity among monofunctional radical polymerizable compounds. ) In the case of acrylates, the adhesion to various substrates is improved. The content of the hydroxyl group-containing (meth)acrylate is preferably 1% by mass to 30% by mass relative to the resin composition. When the content is too large, the water absorption rate of the cured product may increase, and the water resistance may deteriorate. . The content of the carboxyl group-containing (meth)acrylate is preferably 1% by mass to 20% by mass relative to the resin composition. When the content is too large, the optical durability of the polarizing film decreases, which is undesirable. The phosphoric acid group-containing (meth)acrylate includes 2-(meth)acryloyloxyethyl acid phosphate, and the content thereof is preferably 0.1% by mass to 10% by mass relative to the resin composition. In the case of excessive content, the optical durability of the polarizing film is reduced, which is undesirable.

In addition, as the monofunctional radical polymerizable compound, a radical polymerizable compound having an active methylene group can be used. The radically polymerizable compound having an active methylene group is a compound having an active double bond group such as a (meth)acrylic group in the terminal or in the molecule, and having an active methylene group. As the active methylene group, for example, acetylacetoxy, alkoxypropanedioxin, cyanoacetoxy, and the like can be mentioned. The above-mentioned active methylene group is preferably acetyl acetyl group. Specific examples of radical polymerizable compounds having active methylene groups include, for example, 2-acetylacetoxyethyl (meth)acrylate, 2-acetylacetoxyethyl (meth)acrylate Acetyl propyl ester, (meth) acrylate 2-acetyl acetoxy ethyl-1-methyl ethyl (meth) acrylate, etc. Acetyl acetoxy ethyl alkyl ester; (meth) acrylic acid 2 -Ethoxypropanedioxyethyl, 2-cyanoacetoxyethyl (meth)acrylate, N-(2-cyanoacetoxyethyl)acrylamide, N-(2 -Propylacetoxybutyl)acrylamide, N-(4-acetoxyethylmethylbenzyl)acrylamide, N-(2-acetylacetoxybutyl) Base) acrylamide and the like. The radically polymerizable compound having an active methylene group is preferably acetoxyethyl alkyl (meth)acrylate.

In addition, examples of polyfunctional radical polymerizable compounds having two or more functions include N,N'-methylenebis(meth)acrylamide, trifunctional (meth)acrylamide derivatives, and trifunctional (meth)acrylamide derivatives. Propylene glycol di(meth)acrylate, tetraethylene glycol di(meth)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 addition Di(meth)acrylate, bisphenol A propylene oxide adduct di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, neopentyl glycol di(meth) Acrylate, tricyclodecane dimethanol bis (meth) acrylate, cyclic trimethylolpropane formal (meth) acrylate (Cyclic Trimethylolpropane formal (meth) Acrylate), dioxane diol two ( Meth) acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa (Meth) acrylate, EO modified diglycerol tetra(meth)acrylate and other (meth)acrylic acid and polyhydric alcohol esters, 9,9-bis[4-(2-(meth)acryloyloxy) Ethoxy)phenyl]fluorene. As specific examples, 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 Corporation), CD-536 (manufactured by Sartomer Corporation), etc. In addition, if necessary, various epoxy (meth)acrylates, urethane (meth)acrylates, polyester (meth)acrylates, and various (meth)acrylate monomers can be listed. Wait. It should be noted that the polyfunctional (meth)acrylamide derivatives are not only fast in polymerization speed, excellent in productivity, but also excellent in crosslinkability when the adhesive composition is made into a cured product, so it is preferably included in the adhesive Agent composition.

From the viewpoint of compatibility with polarizers, various transparent protective films, and optical durability in harsh environments, the radical polymerizable compound is preferably used in combination with a monofunctional radical polymerizable compound and a polyfunctional radical polymerizable compound. Compound. In addition, since the liquid viscosity of the monofunctional radical polymerizable compound is low, by containing the monofunctional radical polymerizable compound in the resin composition, the liquid viscosity of the resin composition can be reduced. In addition, monofunctional radical polymerizable compounds often have functional groups that exhibit various functions. By including the monofunctional radical polymerizable compound in the resin composition, it can be used in the resin composition and/or the cured product of the resin composition. Shows various functions in. Since the polyfunctional radical polymerizable compound can three-dimensionally crosslink the cured product of the resin composition, it is preferably contained in the resin composition. Regarding the ratio of the monofunctional radical polymerizable compound to the polyfunctional radical polymerizable compound, relative to 100 parts by mass of the monofunctional radical polymerizable compound, the ratio of the polyfunctional radical polymerizable compound is preferably 10 parts by mass to 1000 parts by mass. The range of parts by mass is mixed.

When the active energy rays use electron beams, etc., the radical polymerizable adhesive composition does not need to contain a photopolymerization initiator, but when the active energy rays use ultraviolet or visible light, the adhesive composition preferably contains Photopolymerization initiator.

The photopolymerization initiator in the case of using a radically polymerizable compound can be appropriately selected according to active energy rays. In the case of curing by ultraviolet or visible light, a photopolymerization initiator of ultraviolet or visible light series is used. Examples of the photopolymerization initiator include benzophenones such as benzil, benzophenone, benzoic acid, and 3,3′-dimethyl-4-methoxybenzophenone. Compounds; 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl) ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2- Aromatic ketone compounds such as hydroxypropiophenone and α-hydroxycyclohexyl phenyl ketone; methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy Acetophenone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one and other acetophenone compounds; benzoin methyl ether, benzoin Benzoin ether compounds such as ethyl ether, benzoin isopropyl ether, benzoin butyl ether, and anisole methyl ether; aromatic ketal compounds such as benzil dimethyl ketal; 2 -Aromatic sulfonyl chloride compounds such as naphthalenesulfonyl chloride; photoactive oxime compounds such as 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; thioxanthone, 2- Chlorothioxanthone, 2-Methylthioxanthone, 2,4-Dimethylthioxanthone, Isopropylthioxanthone, 2,4-Dichlorothioxanthone, 2,4-Diethylthioxanthone Thioxanthone compounds such as ketones, 2,4-diisopropylthioxanthone and dodecylthioxanthone; camphorquinone; halogenated ketones; phosphine oxides; phosphonates, etc.

The blending amount of the photopolymerization initiator is 20% by mass 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 mass, more preferably 0.05 to 10% by mass, and still more preferably 0.1 to 5% by mass.

In addition, when the adhesive composition used in the present invention is used for visible light curability containing a radically polymerizable compound as a curable component, particularly a photopolymerization initiator that is highly sensitive to light of 380 nm or more is used. Better. The photopolymerization initiator that is highly sensitive to light of 380 nm or more will be described later.

(式中，R⁶ 及R⁷ 表示-H、-CH₂ CH₃ 、-iPr或Cl，R⁶ 及R⁷ 可以相同或不同)。使用通式(3)所示的化合物的情況下，與單獨使用對380nm以上的光具有高靈敏度的光聚合引發劑的情況相比，黏接性優異。通式(3)所示的化合物中，特佳R⁶ 及R⁷ 為-CH₂ CH₃ 的二乙基噻噸酮。相對於固化性樹脂組合物的總量，固化性樹脂組合物中的通式(3)所示的化合物的組成比率較佳為0.1~5質量%、更佳為0.5~4質量%、進一步更佳為0.9~3質量%。As the above-mentioned photopolymerization initiator, it is preferable to use a compound represented by the following general formula (3) alone; or a combination of a compound represented by the general formula (3) and a photopolymerization initiator with high sensitivity to light of 380 nm or more described later Agent. [Chemical formula 5]

(In the formula, R ⁶ and R ⁷ represent -H, -CH ₂ CH ₃ , -iPr or Cl, and R ⁶ and R ⁷ may be the same or different). When the compound represented by the general formula (3) is used, the adhesiveness is superior compared to 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 (3), R ⁶ and R ⁷ are particularly preferably diethyl thioxanthone in which _{-CH 2} CH _{3 is used.} Relative to the total amount of the curable resin composition, the composition ratio of the compound represented by the general formula (3) in the curable resin composition is preferably 0.1 to 5 mass%, more preferably 0.5 to 4 mass%, and still more Preferably, it is 0.9 to 3% by mass.

In addition, it is preferable to add a polymerization initiation assistant as necessary. Examples of the polymerization initiation aids include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, 4 -Ethyl dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, etc., particularly preferably ethyl 4-dimethylaminobenzoate. In the case of using a polymerization initiation auxiliary agent, its addition amount is usually 0 to 5% by mass, preferably 0 to 4% by mass, and most preferably 0 to 3% by mass relative to the total amount of the curable resin composition.

In addition, a known photopolymerization initiator can be used in combination as necessary. Since the transparent protective film having UV absorption capability does not transmit light of 380 nm or less, it is preferable to use a photopolymerization initiator that is highly sensitive to light of 380 nm or more as the photopolymerization initiator. Specifically, examples include: 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1 -(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-? (Alkolinyl)phenyl)-1-butanone, 2,4,6-trimethylbenzyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzyl)phenyl oxide Phosphine, bis(η5-2,4-cyclopentadien-1-yl)bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium and the like.

(式中，R⁸ 、R⁹ 及R¹⁰ 表示-H、-CH₃ 、-CH₂ CH₃ 、-iPr或Cl，R⁸ 、R⁹ 及R¹⁰ 可以相同或不同)。作为通式(4)所示的化合物，可以適宜使用作為市售品的2-甲基-1-(4-甲硫基苯基)-2-嗎啉代丙烷-1-酮(商品名：IRGACURE907、製造商：BASF)。此外，2-苄基-2-二甲基胺基-1-(4-嗎啉代苯基)-1-丁酮(商品名：IRGACURE369、製造商：BASF)、2-(二甲基胺基)-2-[(4-甲基苯基)甲基]-1-[4-(4-嗎啉基)苯基]-1-丁酮(商品名：IRGACURE379、製造商：BASF)由於靈敏度高，因而較佳。In particular, as the photopolymerization initiator, it is preferable to further contain a compound represented by the following general formula (4) in addition to the photopolymerization initiator of the general formula (3), [Chemical formula 6]

(In the formula, R ⁸ , R ⁹ and R ¹⁰ represent -H, -CH ₃ , -CH ₂ CH ₃ , -iPr or Cl, and R ⁸ , R ⁹ and R ¹⁰ may be the same or different). As the compound represented by the general formula (4), commercially available 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (trade name: IRGACURE907, manufacturer: BASF). In addition, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone (trade name: IRGACURE369, manufacturer: BASF), 2-(dimethylamine Group)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone (trade name: IRGACURE379, manufacturer: BASF) The sensitivity is high, so it is better.

In the above-mentioned adhesive composition, when a radical polymerizable compound having a living methylene group is used as the radical polymerizable compound, it is preferably used in combination with a radical polymerization initiator having a hydrogen abstraction action. According to this structure, the adhesiveness of the adhesive layer which a polarizing film has especially immediately after taking out from a high-humidity environment or water (non-dry state) is improved remarkably. The reason is not clear, but it is believed to be the following reason. In other words, the radical polymerizable compound having a living methylene group is polymerized together with other radical polymerizable compounds constituting the adhesive layer, and enters the main chain and/or side chain of the base polymer in the adhesive layer , Form an adhesive layer. In the polymerization process, if a radical polymerization initiator with a hydrogen abstraction effect is present, the base polymer constituting the adhesive layer is formed, and hydrogen is abstracted from the radical polymerizable compound with active methylene group. Free radicals are generated in the methyl group. In addition, the methylene group that generates free radicals reacts with the hydroxyl group of the polarizer such as PVA to form a covalent bond between the adhesive layer and the polarizer. As a result, it is estimated that the adhesiveness of the adhesive layer of the polarizing film is significantly improved even in a non-dried state.

In the present invention, examples of the radical polymerization initiator having a hydrogen abstraction action include thioxanthone-based radical polymerization initiators, benzophenone-based radical polymerization initiators, and the like. The radical polymerization initiator is preferably a thioxanthone-based radical polymerization initiator. As a thioxanthone radical polymerization initiator, the compound represented by the said general formula (3) is mentioned, for example. Specific examples of the compound represented by the general formula (3) include thioxanthone, dimethylthioxanthone, diethylthioxanthone, isopropylthioxanthone, and chlorothiaxanthone. Among the compounds represented by the general formula (3), R ⁶ and R ⁷ are particularly preferably diethyl thioxanthone in which _{-CH 2} CH _{3 is used.}

When the adhesive composition contains a radical polymerizable compound having a reactive methylene group and a radical polymerization initiator having a hydrogen abstraction effect, when the total amount of curable components is 100% by mass, relative The total amount of the curable resin composition preferably contains 1 to 50% by mass of the radical polymerizable compound having an active methylene group and 0.1 to 10% by mass of a radical polymerization initiator.

As described above, in the present invention, in the presence of a radical polymerization initiator having a hydrogen abstraction effect, the methylene group of the radical polymerizable compound having a reactive methylene group is caused to generate free radicals, and the methylene group interacts with PVA. The hydroxyl groups of the polarizer react to form a covalent bond. Therefore, in order to generate free radicals from the methylene group of the radically polymerizable compound having active methylene groups and to sufficiently form the covalent bond, when the total amount of curable components is 100% by mass, it is preferable to contain active methylene groups. The methyl radical polymerizable compound contains 1 to 50% by mass, more preferably 3 to 30% by mass. In order to sufficiently improve the water resistance and improve the adhesiveness in a non-dry state, it is preferable to make the radical polymerizable compound having an active methylene group to 1% by mass or more. On the other hand, if it exceeds 50% by mass, poor curing of the adhesive layer may occur. In addition, with respect to the total amount of the adhesive composition, a radical polymerization initiator having a hydrogen abstraction effect is preferably contained in 0.1-10% by mass, and more preferably 0.3-9% by mass. In order to allow the hydrogen abstraction reaction to proceed sufficiently, it is preferable to use a radical polymerization initiator of 0.1% by mass or more. On the other hand, if it exceeds 10% by mass, it may not completely dissolve in the composition.

The adhesive composition used in the present invention preferably further contains the following components as necessary.

In the present invention, the adhesive composition may be blended with the compound described in the general formula (1), preferably the compound described in the general formula (1'), and more preferably the compound described later. Compounds described in formulas (1a) to (1d). When these compounds are blended in the adhesive composition, the adhesiveness with the polarizer and the transparent protective film may be improved, which is preferable. From the viewpoint of improving the adhesion between the polarizer and the transparent protective film and the water resistance, in the adhesive composition, the content of the compound described in the general formula (1) is preferably 0.001-50% by mass, more preferably 0.1-30% by mass, most preferably 1-10% by mass.

The bubble inhibitor is a compound that can reduce the surface tension by being blended into the adhesive composition, and thus has the effect of reducing bubbles between the adherend to be bonded. As the bubble inhibitor, for example, polydimethylsiloxane and other organosilicon bubble inhibitors having a polysiloxane skeleton, and (meth)acrylic acid esters formed by polymerizing (meth)acrylic acid esters can be used. Skeleton (meth)acrylic bubble suppressor, polyether bubble suppressor made by polymerizing vinyl ether, cyclic ether, etc., fluorine bubble suppressor made of fluorine-containing compound with perfluoroalkyl group, etc. , When added to the adhesive composition, it has the effect of reducing its surface tension.

The bubble inhibitor preferably has a reactive group in the compound. In this case, when the polarizer and the transparent protective film are bonded together, the generation of lamination bubbles can be reduced. Examples of the reactive group possessed by the bubble suppressor include polymerizable functional groups. Specifically, examples include radical polymerizable groups having olefinic double bonds such as (meth)acryloyl, vinyl, and allyl groups. Functional groups, epoxy groups such as glycidyl groups, cationically polymerizable functional groups such as oxetanyl groups, vinyl ether groups, cyclic ether groups, cyclic thioether groups, and lactone groups. From the viewpoint of reactivity in the adhesive composition, a bubble inhibitor having a double bond as a reactive group is preferred, and a bubble inhibitor having a (meth)acryloyl group is more preferred.

In consideration of the lamination bubble suppressing effect and the adhesion improving effect, among the above-mentioned bubble suppressors, silicone-based bubble suppressors are preferred. In addition, in the bubble suppressor, in consideration of the adhesiveness of the adhesive layer, it is preferable to suppress a bubble containing a urethane bond or an isocyanurate ring structure in the main chain skeleton or side chain. Agent. As the organosilicon-based bubble inhibitor, commercially available products can also be suitably used. For example, "BYK-UV3505" (manufactured by BYK-Chemie Japan) which is an acryl-based modified polydimethylsiloxane is mentioned.

In order to have both the adhesive force of the resulting adhesive layer and the effect of reducing lamination bubbles, when the total amount of the adhesive composition is 100% by mass, the content of the bubble inhibitor is preferably 0.01 to 0.6% by mass.

The adhesive composition used in the present invention may contain an acrylic oligomer obtained by polymerizing a (meth)acrylic monomer in addition to the curable component of the above-mentioned radical polymerizable compound. By including the acrylic oligomer in the adhesive composition, the curing shrinkage when the composition is irradiated with active energy rays and cured can be reduced, thereby reducing the adhesive, polarizer, transparent protective film, etc. The interface stress of the adherent. 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 mass or less, and more preferably 15% by mass or less with respect to the total amount of the adhesive composition. When 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 may be drastically reduced, resulting in poor curing. On the other hand, with respect to the total amount of the adhesive composition, the acrylic oligomer is preferably contained at 3% by mass or more, and more preferably at 5% by mass or more.

In consideration of workability and uniformity during coating, the adhesive composition preferably has a low viscosity. Therefore, the acrylic oligomer formed by the polymerization of (meth)acrylic monomers is also preferably low. Viscosity. As a low-viscosity acrylic oligomer capable of preventing curing shrinkage of the adhesive layer, its weight average molecular weight (Mw) is preferably 15,000 or less, more preferably 10,000 or less, and particularly preferably 5,000 or less. On the other hand, in order to sufficiently suppress 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, and 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, (meth) ) Isopropyl acrylate, 2-methyl-2-nitropropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, secondary butyl (meth)acrylate , Tertiary butyl (meth)acrylate, n-pentyl (meth)acrylate, tertiary pentyl (meth)acrylate, 3-pentyl (meth)acrylate, 2,2-di (meth)acrylate Methyl butyl ester, n-hexyl (meth)acrylate, cetyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 4-(meth)acrylate (Meth)acrylic acid (1-20 carbon atoms) alkyl esters such as methyl-2-propylpentyl ester and n-octadecyl (meth)acrylate, and for example: (meth)acrylic acid cycloalkane Base ester (e.g. cyclohexyl (meth)acrylate, cyclopentyl (meth)acrylate, etc.), aralkyl (meth)acrylate (e.g. benzyl (meth)acrylate, etc.), polycyclic ( Meth) acrylate (e.g. 2-isobornyl (meth)acrylate, 2-norbornyl methyl (meth)acrylate, 5-norbornen-2-yl methyl (meth)acrylate, ( (Meth)acrylate 3-methyl-2-norbornyl methyl ester, etc.), hydroxyl-containing (meth)acrylates (e.g. hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, (Meth) 2,3-dihydroxypropyl methyl butyl acrylate, etc.), alkoxy- or phenoxy-containing (meth)acrylates (2-methoxyethyl (meth)acrylate, ( 2-ethoxyethyl (meth)acrylate, 2-methoxymethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth)acrylate Alcohol esters, phenoxyethyl (meth)acrylate, etc.), epoxy group-containing (meth)acrylates (such as glycidyl (meth)acrylate, etc.), halogen-containing (meth)acrylates ( For example, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,2-trifluoroethyl ethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, (meth)acrylic acid Hexafluoropropyl, octafluoropentyl (meth)acrylate, heptafluorodecyl (meth)acrylate, etc.), alkylaminoalkyl (meth)acrylate (for example, dimethyl (meth)acrylate) Ethyl amino ethyl, etc.) and so on. These (meth)acrylates can be used individually or in combination of 2 or more types. As specific examples of the acrylic oligomer, "ARUFON" manufactured by Toagosei Co., Ltd., "ACTFLOW" manufactured by Soken Chemical Co., Ltd., "JONCRYL" manufactured by BASF Japan Ltd., and the like can be cited.

A photoacid generator may be contained in the above-mentioned adhesive composition. When the photoacid generator is contained in the adhesive composition, the water resistance and durability of the adhesive layer can be greatly improved. The photoacid generator can be represented by the following general formula (5).

(其中，L^＋ 表示任意的鎓陽離子。另外，X^- 表示選自於由PF₆ ^- 、SbF₆ ^- 、AsF₆ ^- 、SbCl₆ ^- 、BiCl₅ ^- 、SnCl₆ ^- 、ClO₄ ^- 、二硫代胺基甲酸鹽陰離子、SCN-所構成組群中的抗衡陰離子。)General formula (5) [Chemical formula 7]

(Wherein, L ⁺ represents any cation Further, X ^-. Selected from the group consisting represents _{^{PF 6 -, SbF 6 -,}} AsF 6 -, SbCl 6 -, BiCl 5 -, SnCl 6 -, ClO 4 -, disulfide The counter anion in the group consisting of carbamate anion and SCN-.)

^{Next, the counter anion X-} in the general formula (5) will be described.

^{In principle, the counter anion X-} in the general formula (5) is not particularly limited, and a non-nucleophilic anion is preferred. When the counter anion X is a non-nucleophilic anion, it is difficult to cause the nucleophilic reaction of the cations coexisting in the molecule and the various materials used in combination. As a result, the photoacid generator represented by the general formula (5) itself and the use of it can be improved. The stability of the composition over time. The non-nucleophilic anion mentioned here refers to an anion with a low ability to cause a nucleophilic reaction. Examples of such anions _{^{include: PF 6 -, SbF 6 -}} , AsF 6 -, SbCl 6 -, BiCl 5 -, SnCl 6 -, ClO 4 -, formate anions dithio group, SCN ^- and the like.

Specifically, preferred specific examples of the photoacid generator of the present invention include "CYRACURE UVI-6992", "CYRACURE UVI-6974" (above, manufactured by Dow Chemical Japan Limited), "Adekaoptomer SP150", and "Adekaoptomer SP152", "Adekaoptomer SP170", "Adekaoptomer SP172" (above, manufactured by ADEKA Co., Ltd.), "IRGACURE250" (manufactured by Ciba Specialty Chemicals Inc.), "CI-5102", "CI-2855" (above, Nippon Soda Co. , Ltd.), "San-Aid SI-60L", "San-Aid SI-80L", "San-Aid SI-100L", "San-Aid SI-110L", "San-Aid SI-180L" (Above, manufactured by Sanshin Chemical Co., Ltd.), "CPI-100P", "CPI-100A" (above, manufactured by San-Apro Ltd.), "WPI-069", "WPI-113", "WPI-116" , "WPI-041", "WPI-044", "WPI-054", "WPI-055", "WPAG-281", "WPAG-567", "WPAG-596" (above, Wako Pure Chemical Industries, Ltd. system).

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

The photoalkali generator is a kind of basic substance that can be used as a radical polymerizable compound and a catalyst for the polymerization reaction of epoxy resin by changing the molecular structure or cleaving the molecule by light irradiation such as ultraviolet light or visible light. Compound. Examples of basic substances include secondary amines and tertiary amines. As the photobase generator, for example, the above-mentioned α-aminoacetophenone compound, the above-mentioned oxime ester compound, having an oxyimino group, an N-methylated aromatic amine group, and an N-acylated aromatic amine can be mentioned. Compounds with substituents such as nitrobenzyl carbamate groups, nitrobenzyl carbamate groups, and alkoxybenzyl carbamate groups. Among them, oxime ester compounds are preferred.

As the compound having an oxyimino group, for example, O,O'-succinic acid benzophenone oxime, O,O'-succinic acid benzophenone oxime, benzophenone oxime acrylate- Styrene copolymer.

Examples of compounds having N-formylated aromatic amine groups and N-formylated aromatic amine groups include di-N-(p-formylamino) diphenylmethane and di-N-( P-Acetylamino)diphenylmethane, bis-N-(p-benzylamino)diphenylmethane, 4-formamide stilbene, 4-acetamido stilbene, 2 , 4-Dimethyamino stilbene, 1-methyaminonaphthalene, 1-acetylaminonaphthalene, 1,5-dimethylaminonaphthalene, 1-methyaminonaphthalene, 1-methyaminonaphthalene Anthracene, 1,4-dimethylaminoanthracene, 1-acetylaminoanthracene, 1,4-dimethylaminoanthracene, 1,5-dimethylaminoanthraquinone, 3 ,3'-dimethyl-4,4'-dimethylamino biphenyl, 4,4'-dimethylamino benzophenone.

Examples of compounds having a nitrobenzylcarbamate group and an alkoxybenzylcarbamate group include: bis{{(2-nitrobenzyl)oxy}carbonyl}diamino group Diphenylmethane, 2,4-bis{(2-nitrobenzyl)oxy}stilbene, bis{(2-nitrobenzyloxy)carbonyl}hexane-1,6-diamine, O-dimethylaniline {{(2-nitro-4-chlorobenzyl)oxy}amide}.

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

As other photobase generators, WPBG-018 (trade name, 9-anthrylmethyl N,N'-diethylcarbamate (9-anthrylmethyl N,N'-diethylcarbamate)), WPBG -027 (trade name, (E)-1-[3-(2-hydroxyphenyl)-2-propenyl]piperidine ((E)-1-[3-(2-hydroxyphenyl) -2-propenoyl ]piperidine)), WPBG-082 (trade name, guanidinium2-(3-benzoylphenyl)propionate), WPBG-140 (trade name, 1-( Anthraquinon-2-yl) ethyl imidazole carboxylate (1-(anthraquinon-2-yl)ethyl imidazolecarboxylate) photobase generator.

In the adhesive composition described above, a photoacid generator and a compound containing any of an alkoxy group and an epoxy group may be used in combination in the adhesive composition.

When using a compound with one or more epoxy groups in the molecule or a polymer (epoxy resin) with two or more epoxy groups in the molecule, it can be used in combination with two or more epoxy groups in the molecule that react with epoxy groups The compound of the functional group. Among them, the functional group reactive with the epoxy group includes, for example, a carboxyl group, a phenolic hydroxyl group, a mercapto group, a primary or secondary aromatic amine group, and the like. In consideration of three-dimensional curability, it is particularly preferable to have two or more of these functional groups in one molecule.

Examples of polymers having one or more epoxy groups in the molecule include epoxy resins, including bisphenol A type epoxy resins derived from bisphenol A and epichlorohydrin, and bisphenol F and epichlorohydrin. Derived bisphenol F epoxy resin, bisphenol S epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, bisphenol F novolac epoxy resin 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, trifunctional type Epoxy resins, polyfunctional epoxy resins such as tetrafunctional epoxy resins, glycidyl ester epoxy resins, glycidylamine epoxy resins, hydantoin epoxy resins, isocyanurate epoxy resins Oxygen resins, aliphatic chain epoxy resins, etc., these epoxy resins may be halogenated or hydrogenated. Examples of commercially available epoxy resin products include: JER code 828, 1001, 801N, 806, 807, 152, 604, 630, 871, YX8000, YX8034, YX4000, and EPICLON830 manufactured by DIC Co., Ltd. manufactured by Japan Epoxy Resin , EXA835LV, HP4032D, HP820, EP4100 series, EP4000 series, EPU series manufactured by ADEKA Co., Ltd., CELLOXIDE series manufactured by Daicel Chemical Industries, Ltd. (2021, 2021P, 2083, 2085, 3000, etc.), Epolead series, EHPE series, YD series, YDF series, YDCN series, YDB series, phenoxy resin manufactured by Nippon Steel Chemical Co., Ltd. (It is a polyhydroxy polyether synthesized from bisphenols and epichlorohydrin and having epoxy groups at both ends; YP Series, etc.), Denacol series manufactured by Nagase ChemteX Corporation, Epolight series manufactured by Kyoeisha Chemical Co., Ltd., but not limited to these. These epoxy resins can be used in combination of two or more types.

The compound having an alkoxy group in the molecule is not particularly limited as long as it has one or more alkoxy group in the molecule, and a known compound can be used. Examples of such compounds include melamine compounds, amino resins, silane coupling agents, and the like.

With respect to the total amount of the adhesive composition, the blending amount of the compound containing either an alkoxy group or an epoxy group is usually 30% by mass or less. If the content of the compound in the composition is too large, the adhesive Decrease in performance, and the impact resistance to the drop weight test may deteriorate. The content of the compound in the composition is more preferably 20% by mass or less. On the other hand, from the viewpoint of water resistance, the compound is preferably contained in the composition at 2% by mass or more, and more preferably 5% by mass or more.

When the adhesive composition used in the present invention is active energy ray curable, the silane coupling agent preferably uses an active energy ray curable compound, but even if it is not active energy ray curable, the same water resistance can be imparted Sex.

Specific examples of the silane coupling agent include vinyl trichlorosilane, vinyl trimethoxy silane, vinyl triethoxy silane, 2-(3,4-epoxy) which are active energy ray-curable compounds. Cyclohexyl) ethyl trimethoxy silane, 3-glycidoxy propyl trimethoxy silane, 3-glycidoxy propyl methyl diethoxy silane, 3-glycidoxy propyl Triethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3- Methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, etc.

Preferred are 3-methacryloxypropyl trimethoxysilane and 3-acryloxypropyl trimethoxysilane.

As a specific example of the non-active energy ray-curable silane coupling agent, a silane coupling agent having an amino group is preferred. Specific examples of the silane coupling agent having an amino group include: γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-aminopropyltriisopropoxy Silane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyl diethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ -(2-Aminoethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)aminopropyl triethoxysilane, γ-(2-aminoethyl) )Aminopropylmethyldiethoxysilane, γ-(2-aminoethyl)aminopropyltriisopropoxysilane, γ-(2-(2-aminoethyl)aminoethyl Yl)aminopropyltrimethoxysilane, γ-(6-aminohexyl)aminopropyltrimethoxysilane, 3-(N-ethylamino)-2-methylpropyltrimethoxysilane , Γ-ureidopropyl trimethoxysilane, γ-ureidopropyl triethoxysilane, N-phenyl-γ-aminopropyl trimethoxysilane, N-benzyl-γ-aminopropyl Trimethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane, N-cyclohexylaminomethyl triethoxysilane, N-cyclohexylaminomethyl diethoxy Methyl silane, N-phenylaminomethyl trimethoxy silane, (2-aminoethyl) aminomethyl trimethoxy silane, N,N'-bis[3-(trimethoxy silane Yl)propyl]ethylenediamine and other amino-containing silanes; N-(1,3-dimethylbutylene)-3-(triethoxysilyl)-1-propylamine and other ketimine-type silanes class.

The silane coupling agent having an amine group may be used alone or in combination of multiple types. Among these, in order to ensure good adhesion, γ-aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-amine) are preferred. Ethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)aminopropyl triethoxysilane, γ-(2-aminoethyl)aminopropyl Methyldiethoxysilane, N-(1,3-dimethylbutylene)-3-(triethoxysilyl)-1-propylamine.

Relative to the total amount of the adhesive composition, the blending amount of the silane coupling agent is preferably in the range of 0.01 to 20% by mass, more preferably 0.05 to 15% by mass, and still more preferably 0.1 to 10% by mass. This is because when the blending amount is more than 20% by mass, the storage stability of the adhesive composition deteriorates, and when it is less than 0.1% by mass, it is difficult to fully exhibit the effect of adhesive water resistance.

Specific examples of non-active energy ray-curable silane coupling agents other than the above include 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropyl Methyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl) tetrasulfide, 3-isocyanatopropyltriethoxysilane, imidazole silane, etc.

When the adhesive composition used in the present invention contains a compound having a vinyl ether group, the adhesion water resistance between the polarizer and the adhesive layer is improved, which is preferable. The reason for this effect is not clear, but it is presumed that one of the reasons is that the vinyl ether group of the compound interacts with the polarizer to increase the adhesive force between the polarizer and the adhesive layer. In order to further improve the adhesion and water resistance of the polarizer and the adhesive layer, the compound is preferably a radical polymerizable compound having a vinyl ether group. In addition, the content of the compound is preferably 0.1 to 19% by mass relative to the total amount of the adhesive composition.

The adhesive composition used in the present invention may contain a compound that produces keto-enol tautomerism. For example, in an adhesive composition containing a crosslinking agent or an adhesive composition capable of being blended with a crosslinking agent, it is preferable to adopt a method including the above-mentioned keto-enol tautomerism-producing compound. Thereby, it is possible to suppress excessive viscosity increase, gelation, and formation of microgels of the adhesive composition after blending the organometallic compound, and the effect of prolonging the pot life of the composition can be achieved.

As the above-mentioned compound that produces keto-enol tautomerism, various β-dicarbonyl compounds can be used. Specific examples include: acetone, 2,4-hexanedione, 3,5-heptanedione, 2-methylhexane-3,5-dione, 6-methylheptane-2, Β-diketones such as 4-dione, 2,6-dimethylheptane-3,5-dione; methyl acetylacetate, ethyl acetylacetate, isopropyl acetylacetate, acetylacetate Acetyl acetates such as tertiary butyl ester; propylacetate esters such as ethyl propylacetate, ethyl propylacetate, isopropyl propylacetate, tertiary butyl propylacetate, etc.; Isobutyryl acetates such as ethyl butyryl acetate, ethyl isobutyryl acetate, isobutyl isopropyl acetate, tertiary butyl isobutyryl acetate, etc.; malonic acid esters such as methyl malonate and ethyl malonate; and many more. Among them, examples of suitable compounds include acetone and acetyl acetate. The above-mentioned keto-enol tautomerism-producing compound may be used alone or in combination of two or more kinds.

The amount of the compound that produces keto-enol tautomerism can be set to 0.05 parts by mass to 10 parts by mass, preferably 0.2 parts by mass to 3 parts by mass (e.g., 0.3 parts by mass to 1 part by mass of the organometallic compound). 2 parts by mass). If the amount of the above-mentioned compound used is less than 0.05 part by mass with respect to 1 part by mass of the organometallic compound, it may sometimes be difficult to exert a sufficient use effect. On the other hand, if the amount of the compound used is more than 10 parts by mass relative to 1 part by mass of the organometallic compound, it may interact excessively with the organometallic compound and it may become difficult to express the target water resistance.

The adhesive composition of the present invention may contain polyrotaxane. The polyrotaxane has a cyclic molecule, a linear molecule penetrating the opening of the cyclic molecule, and a chain seal arranged at both ends of the linear molecule so that the cyclic molecule is not separated from the linear molecule base. It is preferable that the cyclic molecule has an active energy ray-curable functional group.

The cyclic molecule is not particularly limited as long as it is a molecule whose openings enclose linear molecules in a string, can move on the linear molecules, and have an active energy ray polymerizable group. In addition, in this specification, the "cyclic" of the "cyclic molecule" means that it is substantially "cyclic." That is, as long as it can move on a linear molecule, the cyclic molecule may not completely close the ring.

Specific examples of cyclic molecules include cyclic polymers such as cyclic polyethers, cyclic polyesters, cyclic polyetheramines, and cyclic polyamines, and α-cyclodextrin, β-cyclodextrin, and γ -Cyclodextrins such as cyclodextrin. Among them, cyclodextrins such as α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin, which are relatively easy to obtain and can select many types of chain-blocking groups, are preferred. Two or more types of cyclic molecules may be mixed in the polyrotaxane or the binder.

In the polyrotaxane used in the present invention, the cyclic molecule has an active energy ray polymerizable group. Thereby, the polyrotaxane reacts with the active energy ray curable component, and an adhesive whose crosslinking point is movable even after curing can be obtained. The active energy ray polymerizable group possessed by the cyclic molecule may be a group capable of polymerizing with the above-mentioned active energy ray curable compound, and examples thereof include (meth)acryloyl and (meth)acryloyloxy groups. Radical polymerizable groups such as groups.

When cyclodextrin is used as the cyclic molecule, it is preferable to introduce an active energy ray polymerizable group to the hydroxyl group of the cyclodextrin through any appropriate linker. The number of active energy ray polymerizable groups contained in one molecule of polyrotaxane is preferably from 2 to 1280, more preferably from 50 to 1,000, and still more preferably from 90 to 900.

Preferably, a hydrophobic modification group is introduced into the cyclic molecule. By introducing a hydrophobic modification group, the compatibility with active energy ray curable components can be improved. In addition, due to the hydrophobicity, when used in a polarizing film, water can be prevented from entering the interface between the adhesive layer and the polarizing member, and the water resistance can be further improved. Examples of the hydrophobic modification group include polyester chains, polyamide chains, alkyl chains, alkylene oxide chains, ether chains, and the like. As a specific example, the groups described in paragraphs [0027] to [0042] of WO2009/145073 can be cited.

A polarizing film using a polyrotaxane-containing resin composition as an adhesive has excellent water resistance. The reason why the water resistance of the polarizing film is improved has not yet been determined, but it is presumed as follows. That is, it is believed that the crosslinking point can move due to the mobility of the cyclic molecules of the polyrotaxane (the so-called pulley effect), thereby imparting flexibility to the cured adhesive and adhering to the uneven surface of the polarizer As a result, the intrusion of water into the interface between the polarizer and the adhesive layer is prevented. In addition, it is believed that by making the polyrotaxane have a hydrophobic modification group, hydrophobicity can be imparted to the adhesive, which also helps prevent water from intruding into the interface between the polarizer and the adhesive layer. The content of the polyrotaxane relative to the resin composition is preferably 2% by mass to 50% by mass.

In the present invention, in order to form the adhesive layer, a cationically polymerizable adhesive composition can be used. As the cationically polymerizable compound used in the cationically polymerizable adhesive composition, it can be classified into a monofunctional cationically polymerizable compound having one cationically polymerizable functional group in the molecule, and a cationically polymerizable compound having two or more cationically polymerizable functional groups in the molecule. Multifunctional cationic polymerizable compound. Since the liquid viscosity of the monofunctional cationically polymerizable compound is low, by containing the monofunctional cationically polymerizable compound in the resin composition, the liquid viscosity of the resin composition can be reduced. In addition, monofunctional cationically polymerizable compounds often have functional groups that exhibit various functions. By including the monofunctional cationically polymerizable compound in the resin composition, it can be expressed in the resin composition and/or the cured resin composition. Various functions are provided. Since the polyfunctional cationically polymerizable compound can three-dimensionally crosslink the cured product of the resin composition, it is preferably contained in the resin composition. Regarding the ratio of the monofunctional cationic polymerizable compound to the polyfunctional cationic polymerizable compound, it is preferable that the multifunctional cationic polymerizable compound be in the range of 10 parts by mass to 1000 parts by mass relative to 100 parts by mass of the monofunctional cationic polymerizable compound. mixing. Examples of the cationically polymerizable functional group include an epoxy group, an oxetanyl group, and a vinyl ether group. Examples of compounds having epoxy groups include aliphatic epoxy compounds, alicyclic epoxy compounds, and aromatic epoxy compounds. Since they are excellent in curability and adhesiveness, it is particularly preferred to contain alicyclic epoxy compounds as The cationic polymerizable adhesive composition of the present invention. As the alicyclic epoxy compound, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, 3,4-epoxycyclohexylmethyl-3,4-cyclic Modified caprolactone, modified trimethylcaprolactone, and modified valerolactone of oxycyclohexane carboxylate. Specifically, CELLOXIDE 2021, CELLOXIDE 2021A, CELLOXIDE 2021P, and CELLOXIDE 2081 , CELLOXIDE 2083, CELLOXIDE 2085 (the above is made by Daicel Chemical Industry Co., Ltd.), Cyracure UVR-6105, Cyracure UVR-6107, Cyracure 30, R-6110 (the above is made by Dow Chemical Japan Ltd.), etc. Since it has the effect of improving the curability of the cationically polymerizable adhesive composition of the present invention and reducing the liquid viscosity of the composition, it is preferable to contain a compound having an oxetanyl group. Examples of the compound having oxetanyl group include 3-ethyl-3-hydroxymethyloxetane, 1,4-bis[(3-ethyl-3-oxetanyl)methoxy Methyl]benzene, 3-ethyl-3-(phenoxymethyl)oxetane, bis[(3-ethyl-3-oxetanyl)methyl]ether, 3-ethyl 3-(2-ethylhexyloxymethyl)oxetane, novolac oxetane, etc., commercially available ARON OXETANE OXT-101, ARON OXETANE OXT-121, ARON OXETANE OXT-211 , ARON OXETANE OXT-221, ARON OXETANE OXT-212 (the above are manufactured by Toagosei Co., Ltd.), etc. Since it has the effect of improving the curability of the cationically polymerizable adhesive composition of the present invention and reducing the liquid viscosity of the composition, it is preferable to contain a compound having a vinyl ether group. Examples of the compound having a vinyl ether group include 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, and triethylene diethylene glycol. Alcohol divinyl ether, cyclohexane dimethanol divinyl ether, cyclohexane dimethanol monovinyl ether, tricyclodecane vinyl ether, cyclohexyl vinyl ether, methoxyethyl vinyl ether, ethyl Oxyethyl vinyl ether, pentaerythritol type tetravinyl ether, etc.

The cationic polymerizable adhesive composition contains at least one compound selected from the group consisting of 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, and they They are all cured by cationic polymerization, so a photocationic polymerization initiator is blended. The photocationic polymerization initiator generates cationic species or Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, thereby initiating the polymerization reaction of epoxy groups and oxetanyl groups. As a photocationic polymerization initiator, a photoacid generator and a photobase generator can be used, and the photoacid generator mentioned later can be used suitably. In addition, in the case of using the adhesive composition used in the present invention as the 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, a compound that shows great absorption in the vicinity of 300 nm or a wavelength region shorter than 300 nm. Therefore, by blending in a longer wavelength region, specifically, a compound that exhibits great absorption under light of a wavelength longer than 380 nm The photosensitizer can sense light of a wavelength near it and promote the production of cationic species or acid from the photocationic polymerization initiator. Examples of photosensitizers include anthracene compounds, pyrene compounds, carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, photoreducible dyes, etc., and they may also be mixed Use more than two kinds. In particular, anthracene compounds are excellent in photosensitizing effects and are therefore preferred. Specific examples include Anthracure UVS-1331 and Anthracure UVS-1221 (manufactured by Kawasaki Chemical Co., Ltd.). The content of the photosensitizer is preferably 0.1% by mass to 5% by mass, more preferably 0.5% by mass to 3% by mass.

＜Adhesive layer＞ The adhesive layer is formed by curing the adhesive composition and the easy-adhesive composition. Specifically, first, in the bonding step, the uncured adhesive composition applied to the bonding surface of the transparent protective film and the uncured easy bonding composition applied to the bonding surface of the polarizer mixing. Then, in the subsequent bonding step, by irradiating active energy rays, the adhesive composition and the easy-adhesive composition are cured in a mixed state to form an adhesive layer. The thickness of the adhesive layer is preferably 0.01 to 3.0 μm. In the case where the thickness of the adhesive layer is too thin, the cohesive force of the adhesive layer is insufficient, and the peeling force is reduced, which is undesirable. When the thickness of the adhesive layer is too thick, it is easy to cause peeling when stress is applied to the cross section of the polarizing film, and peeling failure due to impact occurs, which is undesirable. The thickness of the adhesive layer is more preferably 0.1 to 2.5 μm, most preferably 0.5 to 1.5 μm.

In the present invention, the SP value of the average SP value calculated by the volume ratio of the SP value of the uncured adhesive composition and the SP value of the uncured easy-adhesive composition and the SP value of the transparent protective film The SP value of the adhesive layer obtained after curing is designed so that the distance becomes 5.8 or less. Here, in the present invention, the adhesive composition and the easy-adhesive composition are cured in a mixed state to form an adhesive layer. Therefore, the SP value of the adhesive layer obtained after curing can be compared with the adhesive The SP value of the composition and the SP value of the easy-adhesive composition were calculated by averaging based on the respective volume ratios. Regarding the lower limit of the SP value distance between the SP value of the transparent protective film and the SP value of the adhesive layer, from the viewpoint of effectively suppressing the generation of bubbles in the polarizing film, for example, 5.3 or more can be exemplified.

(式中，X為包含反應性基團的官能團，R¹ 及R² 分別獨立地表示氫原子、可亦具有取代基的脂肪族烴基、芳基或雜環基)。藉由將含有上述通式(1)表示的含硼化合物的易黏接組合物塗敷於偏光件的貼合面，特別地，偏光薄膜的耐水黏接性提高，因而較佳。表現出上述效果的理由尚未明確，但可以推定出以下的理由。<Easy-adhesive composition> In order to further improve the adhesiveness between the polarizer and the transparent protective film, in the present invention, it is preferable to apply easy coating on the bonding surface of the polarizer (the bonding surface with the transparent protective film). Bonding composition. Preferably, the aforementioned easy-adhesive composition contains a compound represented by the following general formula (1), [Chemical formula 8]

(In the formula, X is a functional group containing a reactive group, and R ¹ and R ² each independently represent a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, or a heterocyclic group which may also have a substituent). By applying the easy-adhesive composition containing the boron-containing compound represented by the above general formula (1) to the bonding surface of the polarizer, in particular, the water-resistant adhesiveness of the polarizing film is improved, which is preferable. The reason for the above-mentioned effect is not clear, but the following reasons can be inferred.

In the easy-adhesive composition, the boron-containing compound described in the above formula (1) can react with functional groups such as the hydroxyl group of the polarizer, thereby improving the adhesion between the polarizer and the adhesive layer. As a result, Plays the effect of improving the water-resistant adhesiveness of the polarizing film.

In the above general formula (1), examples of the aliphatic hydrocarbon group include linear or branched alkyl groups having 1 to 20 carbon atoms, which may also have substituents, and those having 3 to 20 carbon atoms, which may also have substituents. The cyclic alkyl group and the alkenyl group having 2 to 20 carbon atoms. Examples of the aryl group include the phenyl group having 6 to 20 carbon atoms, which may also have substituents, and the phenyl group having 10 to 20 carbon atoms, which may also have substituents. Examples of the heterocyclic group include a 5-membered ring or 6-membered ring group which contains at least one heteroatom and may also have a substituent. They can be connected to each other to form a ring. In the general formula (1), as R ¹ and R ² , a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms is preferred, and a hydrogen atom is most preferred. It should be noted that in the final manufactured polarizing film, the compound represented by the general formula (1) may exist in the easy-adhesive layer between the polarizer and the adhesive layer in an unreacted state, or in each The functional group exists in it in the state after the reaction. In addition, in the present invention, the easy-adhesive layer may be formed by applying the easy-adhesive composition to the entire surface on the side where the adhesive layer of the polarizer is formed, or it may be formed by coating the easy-adhesive composition on at least a part of the surface. The bonding composition forms an easy bonding layer.

X in the compound represented by the general formula (1) is a functional group containing a reactive group, and is a functional group capable of reacting with the curable component constituting the adhesive layer. Examples of the reactive group contained in X include : Hydroxyl group, amino group, aldehyde group, carboxyl group, vinyl group, (meth)acrylic acid group, styryl group, (meth)acrylic acid amino group, vinyl ether group, epoxy group, oxetanyl group, α,β-unsaturated carbonyl, mercapto, halogen group, etc. In the case where the curable resin composition constituting the adhesive layer is curable with active energy rays, the reactive group contained in X is preferably selected from vinyl, (meth)acryloyl, styrene Group, (meth)acrylamido group, vinyl ether group, epoxy group, oxetanyl group and mercapto group constituted by at least one reactive group, especially in the formation of the adhesive layer When the adhesive composition is radically polymerizable, the reactive group contained in X is preferably selected from the group consisting of (meth)acrylic acid groups, styryl groups, and (meth)acrylic acid amino groups. At least one kind of reactive group in the constituent group, when the compound represented by the general formula (1) has a (meth)acrylamido group, the reactivity is high, and the copolymerization with the active energy ray curable resin composition The rate is increased and therefore better. In addition, the (meth)acrylamide group has high polarity and excellent adhesiveness, and therefore, it is also preferable from the viewpoint of efficiently obtaining the effects of the present invention. When the curable resin composition constituting the adhesive layer is cationically polymerizable, the reactive group contained in X preferably has a group selected from the group consisting of a hydroxyl group, an amino group, an aldehyde group, a carboxyl group, a vinyl ether group, and an epoxy group. At least one kind of functional group among oxetanyl group, oxetanyl group and mercapto group, especially when it has an epoxy group, the obtained curable resin layer has excellent adhesion with the adherend, so it is preferred. In the case of a base ether group, the curable resin composition is excellent in curability, which is preferable.

(式中，Y為有機基團，X’為X所含的反應性基團，R¹ 及R² 與上述定義相同)。進一步可適宜列舉以下的化合物(1a)~(1d)。As a preferable specific example of the compound represented by the general formula (1), a compound represented by the following general formula (1') can be cited, [Chemical formula 9]

(In the formula, Y is an organic group, X'is a reactive group contained in X, and R ¹ and R ² are the same as defined above). Furthermore, the following compounds (1a) to (1d) can be suitably mentioned.

[Chemical formula 10]

In the present invention, the compound represented by the general formula (1) may be a compound in which a reactive group is directly bonded to a boron atom, but as shown in the above specific examples, the compound represented by the general formula (1) is preferred It is a compound in which a reactive group and a boron atom are bonded through an organic group, that is, it is preferably a compound represented by the general formula (1'). When the compound represented by the general formula (1) is, for example, a compound that bonds to a reactive group through an oxygen atom bonded to a boron atom, the adhesion 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 when a boron atom is bonded to an organic group, has a boron-carbon bond, and contains a reactive group (for the general formula (1) ')), the adhesion water resistance of the polarizing film is improved, so it is better. The above-mentioned organic group specifically refers to an organic group having 1 to 20 carbon atoms that may also have a substituent. More specifically, examples thereof include linear or branched carbon atoms having 1 to 20 that may also have substituents. Alkylene groups, cyclic alkylene groups with 3-20 carbon atoms, which may also have substituents, phenylene groups with 6-20 carbon atoms, which may also have substituents, and phenylene groups with 10-20 carbon atoms. Also has a substituted naphthylene group.

As the compound represented by the general formula (1), in addition to the above-exemplified compounds, an ester formed by hydroxyethyl acrylamide and boric acid, an ester formed by hydroxymethacrylamide and boric acid, hydroxyethyl acrylate and boric acid can be exemplified The formed ester, the ester formed by hydroxybutyl acrylate and boric acid, and the ester formed by (meth)acrylate and boric acid.

In the easy-adhesive composition, when the content of the compound represented by the general formula (1) is too small, the proportion of the compound represented by the general formula (1) present on the surface of the easy-adhesive layer decreases, and the easy-adhesive effect becomes low Happening. Therefore, in the easy-adhesive composition, the content of the compound represented by the general formula (1) is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and still more preferably 0.1% by mass or more.

In the present invention, in addition to the compound described in the above general formula (1) and the compound described in the above general formula (2), a solvent may be contained in the easy-adhesive composition. As the solvent that can be contained in the easy-adhesive composition (A), a solvent capable of stably dissolving or dispersing the compound represented by the general formula (1) is preferred. As the solvent, an organic solvent, water, or a mixed solvent thereof can be used. As the above-mentioned solvent, for example, it can be selected from the following: ethyl acetate, butyl acetate, 2-hydroxyethyl acetate and other esters; methyl ethyl ketone, acetone, cyclohexanone, methyl isobutyl ketone, diethyl ketone, Ketones such as methyl n-propyl ketone and acetone; cyclic ethers such as tetrahydrofuran (THF) and dioxane; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; aromatics such as toluene and xylene Group hydrocarbons; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol, cyclohexanol, etc.; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether and other two Alcohol ethers; glycol ether acetates such as diethylene glycol monomethyl ether acetate and diethylene glycol monoethyl ether acetate; etc.

In addition, in the present invention, when the easy-adhesive composition is used, other additives, such as stabilizers such as thickeners, ultraviolet absorbers, antioxidants, and heat-resistant stabilizers, may also be contained.

＜Easy bonding layer＞ In the manufacturing method of the polarizing film of the present invention, the easy-adhesive layer can be formed by the second coating step of applying the easy-adhesive composition to the bonding surface of the polarizer as needed, and then the easy-adhesive layer can be formed. In the present invention, when the thickness of the easy-adhesive layer provided in the polarizer is too thick, the cohesive force of the easy-adhesive layer may decrease, and the easy-adhesive effect may decrease. Therefore, the thickness of the easy-adhesion layer is 300 nm or less, preferably 200 nm or less, and more preferably 100 nm or less from the viewpoint of productivity. On the other hand, as the lower limit of the thickness for the easy-adhesive layer to fully exert its effect, at least the thickness of the monomolecular film of the compound represented by the general formula (1) is generally 0.1 nm or more, preferably 1 nm or more, more preferably 2 nm or more.

＜Polarizer＞ In the present invention, from the viewpoint of improving the optical durability in severe environments under high temperature and high humidity, as the polarizer, a thin polarizer having a thickness of 3 μm or more and 15 μm or less is preferably used. In particular, it is preferably 12 μm or less, more preferably 10 μm or less, and particularly preferably 8 μm or less. Such a thin polarizer has less unevenness in thickness, is excellent in visibility, and has little dimensional change, and therefore, is excellent in durability against thermal shock.

The polarizer uses a polarizer using polyvinyl alcohol-based resin. As the polarizer, for example, iodine and dichroic dyes are adsorbed on polyvinyl alcohol-based films, partially formalized polyvinyl alcohol-based films, ethylene-vinyl acetate copolymer-based partially saponified films, etc. Polyene-based oriented films, such as films obtained by uniaxially stretching polyvinyl alcohol films, dehydrated polyvinyl alcohol, and dehydrochloric acid-treated polyvinyl chloride. Among these, a polarizer made of a dichroic substance such as a polyvinyl alcohol-based film and iodine is preferable.

A polarizer obtained by dyeing a polyvinyl alcohol-based film with iodine and uniaxially stretched it can be produced, for example, by immersing polyvinyl alcohol in an aqueous solution of iodine for dyeing, and stretching it to 3 of its original length. ~7 times. If necessary, it may also contain boric acid, zinc sulfate, and zinc chloride, and may also be immersed in an aqueous solution such as potassium iodide. In addition, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed with water before dyeing. By washing the polyvinyl alcohol film with water, not only the stains and anti-blocking agent on the surface of the polyvinyl alcohol film can be cleaned, but also the effect of preventing unevenness such as uneven dyeing by swelling the polyvinyl alcohol film. Stretching may be performed after dyeing with iodine, or stretching may be performed while dyeing, or it may be dyed with iodine after stretching. Stretching can also be carried out in aqueous solutions such as boric acid and potassium iodide, or in a water bath.

From the aspects of tensile stability and humidification reliability, it is preferable that the polarizer contains boric acid. In addition, from the viewpoint of suppressing the occurrence of through cracks, the content of boric acid contained in the polarizer is preferably 22% by mass or less, and more preferably 20% by mass or less relative to the total amount of the polarizer. From the viewpoints of tensile stability and humidification reliability, the boric acid content is preferably 10% by mass or more, and more preferably 12% by mass or more with respect to the total amount of the polarizer.

Representative thin polarizers include Japanese Patent No. 4751486, Japanese Patent No. 4751481, Japanese Patent No. 4815544, Japanese Patent No. 5048120, International Publication No. 2014/077599 Pamphlet, International Publication The thin polarizer described in pamphlet No. 2014/077636, etc., or the thin polarizer obtained by the manufacturing method described in these documents.

As the above-mentioned thin polarizer, in the manufacturing method including the step of stretching in the state of a laminate and the step of dyeing, from the viewpoint that it can be stretched to a high magnification to improve the polarization performance, it is preferable to use, for example, Japanese Patent No. 4751486 The thin polarizer obtained by the manufacturing method including the step of stretching in an aqueous boric acid solution as described in the specification of Japanese Patent No. 4751481, and the specification of Japanese Patent No. 4815544 is particularly described in the specification of Japanese Patent No. 4751481. The manufacturing method of Japanese Patent No. 4815544, which includes a step of auxiliary stretching in a gas atmosphere before stretching in an aqueous solution of boric acid, is preferably a thin polarizer obtained. These thin polarizing films can be produced by a manufacturing method including a step of stretching a polyvinyl alcohol-based resin (hereinafter, also referred to as a PVA-based resin) layer and a resin substrate for stretching in a laminate state and a step of dyeing obtain. According to this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched by being supported by the resin base material for stretching without causing problems such as breakage due to stretching.

＜Transparent protective film＞ As the transparent protective film used in the present invention, a transparent protective film having an SP value at which the SP value distance between the SP values of the adhesive composition is 5.3 or more is used. In addition, the measuring method of the SP value of a transparent protective film is mentioned later. In addition, the transparent protective film used in the present invention preferably has excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and the like. Examples include polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulosic polymers such as cellulose diacetate and cellulose triacetate, and polymethylmethacrylate Acrylic polymers such as esters, styrene polymers such as polystyrene, acrylonitrile-styrene copolymer (AS resin), polycarbonate polymers, etc. In addition, polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, polyolefin polymers such as ethylene-propylene copolymers, vinyl chloride polymers, nylons, aromatic polyamides and other amides Polymers, imine polymers, turbid polymers, polyether turbid polymers, polyether ether ketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers , Vinyl butyral polymers, polyarylate polymers, polyoxymethylene polymers, epoxy polymers, or mixtures of the above polymers. One or more arbitrary suitable additives may be contained in the transparent protective film. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, colorants, and the like. The content of the thermoplastic resin in the transparent protective film is preferably from 50 to 100% by mass, more preferably from 50 to 99% by mass, still more preferably from 60 to 98% by mass, particularly preferably from 70 to 97% by mass. When the content of the thermoplastic resin in the transparent protective film is 50% by mass or less, there is a possibility that the high transparency inherent in the thermoplastic resin may not be sufficiently expressed.

In addition, examples of the transparent protective film include polymer films described in Japanese Patent Application Laid-Open No. 2001-343529 (WO01/37007), such as (A) a thermoplastic resin containing a substituted and/or unsubstituted imidine group on the side chain And a resin composition of a thermoplastic resin having a substituted and/or unsubstituted phenyl group and a nitrile group in the side chain. As a specific example, a film containing a resin composition of an alternating copolymer of isobutylene and N-methylmaleimide and an acrylonitrile-styrene copolymer can be cited. As the film, a film formed from a mixed extrusion product of a resin composition or the like can be used. These films have a small retardation and a small photoelastic coefficient, and therefore can eliminate problems such as unevenness caused by the strain of the polarizing film. In addition, the moisture permeability is small, and therefore, the humidification durability is excellent.

In addition, the moisture permeability of the transparent protective film used in the present invention is preferably 150 g/m ² /24h or less. According to this configuration, moisture in the air does not easily enter the polarizing film, and it is possible to suppress changes in the moisture content of the polarizing film itself. As a result, it is possible to suppress curling and dimensional changes of the polarizing film caused by the storage environment.

As a transparent protective film provided on one or both sides of the polarizer, a transparent protective film with excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc. is preferred, and the moisture permeability is more preferably 150g/ m ² /24h or less, particularly ^{preferably 120 g/m 2} /24h or less, and still more preferably 5 to 70 g/m ² /24h or less.

As a material for forming a transparent protective film that satisfies the aforementioned low moisture permeability, for example, polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate resins; polyarylate resins can be used. ; Amine resins such as nylon and aromatic polyamides; polyolefin polymers such as polyethylene, polypropylene, and ethylene-propylene copolymers, cyclic olefin resins having a cyclic or norbornene structure, (former Base) Acrylic resins, or their mixtures. Among the above resins, polycarbonate resins, cyclic polyolefin resins, and (meth)acrylic resins are preferred, and cyclic polyolefin resins and (meth)acrylic resins are particularly preferred.

The thickness of the transparent protective film can be appropriately determined. Generally speaking, it is preferably 5 to 100 μm in terms of strength, handling properties, and other aspects such as workability and thin layer properties. Especially preferably 10~60μm, even more preferably 13~40μm.

The above-mentioned transparent protective film generally uses a transparent protective film with a frontal retardation of less than 40 nm and a thickness direction retardation of less than 80 nm. The frontal phase difference Re is represented by Re=(nx-ny)×d. The thickness direction retardation Rth is represented by Rth=(nx-nz)×d. In addition, the Nz coefficient is represented by Nz=(nx-nz)/(nx-ny). [Here, let the refractive index of the slow axis direction, the advancing axis direction, and the thickness direction of the film be nx, ny, and nz, respectively, and let d (nm) be the thickness of the film. The slow axis direction is the direction in which the refractive index in the film plane reaches the maximum. ]. It should be noted that the transparent protective film is preferably as colorless as possible. It is preferable to use a protective film with a retardation value of -90nm~+75nm in the thickness direction. By using the protective film with the retardation value (Rth) in the thickness direction of -90nm~+75nm, the coloring (optical coloring) of the polarizing film caused by the transparent protective film can be basically eliminated. The thickness direction retardation value (Rth) is more preferably -80nm~+60nm, particularly preferably -70nm~+45nm.

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

Examples of the retardation plate include: a birefringent film obtained by uniaxially or biaxially stretching a polymer raw material, an alignment film of a liquid crystal polymer, and a phase obtained by supporting an alignment layer of a liquid crystal polymer by a film. Poor board and so on. The thickness of the phase difference plate is also not particularly limited, and it is usually about 20 to 150 μm. Examples of polymer raw materials include polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, and methyl cellulose. , Polycarbonate, polyacrylate, polyethylene, polyethylene terephthalate, polyethylene naphthalate, polyether sulfide, polyphenylene sulfide, polyphenylene ether, polyallyl sulfonic acid , Polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose resin, cyclic polyolefin resin (norbornene resin), or their binary system, ternary system, various copolymers, grafts Copolymers, blends, etc. These polymer raw materials become aligned (stretched films) by stretching or the like.

As the liquid crystal polymer, for example, various liquid crystal polymers in which a conjugated linear atom group (messogen) that imparts liquid crystal alignment is introduced into the main chain of the polymer, the main chain type of the side chain, and the side chain type can be mentioned. Wait. As a specific example of the main chain type liquid crystal polymer, a structure in which a mesogen group is bonded with a spacer portion imparting flexibility, such as a nematic-aligned polyester-based liquid crystal polymer, Discotic polymers, cholesteric polymers, etc. Specific examples of side-chain type liquid crystal polymers include polysiloxane, polyacrylate, polymethacrylate, or polymalonate as the main chain skeleton, and a spacer composed of conjugated atomic groups is interposed. The portion has a mesogenic portion composed of a nematic alignment-imparting para-substituted cyclic compound unit as a side chain liquid crystal polymer. These liquid crystal polymers are, for example, liquid crystal polymers obtained by polishing the surface of thin films such as polyimide and polyvinyl alcohol formed on a glass plate, and liquid crystal obtained by obliquely vaporizing silicon oxide. For polymers and the like, a solution of a liquid crystalline polymer is spread on the alignment treatment surface and heat-treated.

The retardation plate may be, for example, various wave plates, a retardation plate having suitable retardation according to the purpose of use, the purpose of which is to use the birefringence of the liquid crystal layer to compensate for the coloring, viewing angle, etc., or it may be a stack of two or more types. The phase difference plate thus controls the phase difference and other optical characteristics of the phase difference plate.

The phase element difference plate can be selected and used according to various purposes. It satisfies nx=ny>nz, nx>ny>nz, nx>ny=nz, nx>nz>ny, nz=nx>ny, nz>nx>ny, nz>nx = Ny phase difference plate. It should be noted that ny=nz includes not only the case where ny and nz are exactly the same, but also the case where ny and nz are substantially the same.

For example, among the phase difference plates satisfying nx>ny>nz, it is preferable to use a phase difference plate having a frontal phase difference of 40-100 nm, a thickness direction phase difference of 100-320 nm, and an Nz coefficient of 1.8-4.5. For example, for a phase difference plate (positive A plate) that satisfies nx>ny=nz, it is preferable to use a phase difference plate whose front phase difference satisfies 100 to 200 nm. For example, for a phase difference plate (negative A plate) that satisfies nz=nx>ny, it is preferable to use a phase difference plate whose front phase difference satisfies 100 to 200 nm. For example, for a phase difference plate that satisfies nx>nz>ny, it is preferable to use a phase difference plate that has a frontal phase difference of 150 to 300 nm and an Nz coefficient that is greater than 0 and less than 0.7. In addition, as described above, for example, a phase difference plate satisfying nx=ny>nz, nz>nx>ny, or nz>nx=ny can be used.

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

For example, it can be used in the case of IPS (In-Plane Switching, including FFS), when the transparent protective film on one side of the polarizing film has a phase difference, or when it does not have a phase difference. For example, when there is no phase difference, it is preferable that there is no phase difference between the upper and lower sides (cell side) of the liquid crystal cell. The case where there is a phase difference is preferably a case where the upper and lower sides of the liquid crystal cell have a phase difference, and a case where any one of the upper and lower sides has a phase difference (for example, the upper side has a biaxial film satisfying the relationship nx>nz>ny, and the lower side has no phase In the case of poor, the upper side has a positive A plate, and the lower side has a positive C plate). When there is a phase difference, the range of Re=-500~500nm and Rth=-500~500nm is preferable. When described in terms of three-dimensional refractive index, nx>ny=nz, nx>nz>ny, nz>nx=ny, nz>nx>ny (positive A plate, biaxial, positive C plate) are preferable.

For the transparent protective film, in order to compensate for its mechanical strength and handleability, a peelable base material may be further laminated. The peelable base material can be peeled from the laminate containing the transparent protective film and the polarizer in a step or in another step before or after bonding the transparent protective film and the polarizer.

Hereinafter, each step in the manufacturing method of the polarizing film of the present invention will be described.

The manufacturing method of the polarizing film of the present invention is a method of manufacturing a polarizing film in which a transparent protective film is provided on at least one side of a polarizer via an adhesive layer. The method includes: a first coating step, laminating the transparent protective film The adhesive composition is coated on the surface; the second coating step is to coat the easy-adhesive composition on the bonding surface of the polarizer; the bonding step is to bond the polarizer and the transparent protective film; the bonding step is from the polarized light Active energy rays are irradiated on the surface side of the transparent protective film or the surface of the transparent protective film to cure the adhesive composition and the easy-adhesive composition to obtain an adhesive layer, so that the polarizing member and the transparent protective film are adhered via the adhesive layer. Pick up.

It should be noted that the polarizer and the transparent protective film may be subjected to surface modification treatment before the coating step. In particular, it is better to perform surface modification treatment on the surface of the polarizer. As the surface modification treatment, corona treatment, plasma treatment, excimer treatment, flame treatment, etc. can be cited, and corona treatment is particularly preferred. By performing corona treatment, reactive functional groups such as carbonyl groups and amine groups are generated on the surface of the polarizer, and the adhesion to the adhesive layer is improved. In addition, the ashing effect can remove impurities on the surface or reduce the unevenness of the surface, thereby making a polarizing film with excellent appearance characteristics.

<The application procedure of the adhesive composition> As a method of applying the adhesive composition to the bonding surface of the transparent protective film, it can be appropriately selected according to the viscosity of the composition and the target thickness. From the viewpoint of the removal of foreign matter on the surface of the transparent protective film and the coating properties, it is preferably used After measuring the coating method. Specific examples of the post-measurement coating method include a gravure roll coating method, a forward roll coating method, an air knife coating method, and a rod/rod coating method. Among these, from the viewpoint of the removal of foreign matter on the surface of the transparent protective film and the coating properties, the gravure roll coating method is particularly preferred.

<The application procedure of the easy-adhesive composition> In the present invention, the easy-adhesive composition can be coated on one side of the polarizer, or the easy-adhesive composition can be coated on both sides of the polarizer. As a method of applying the easy-adhesive composition to the bonding surface of the polarizer, it is preferable to use the post-measurement coating method from the viewpoint of exerting the same effect as the application step of the adhesive composition.

In the gravure roll coating method, various patterns can be formed on the surface of the gravure roll, for example, a honeycomb pattern, a trapezoidal pattern, a lattice pattern, a tapered pattern, or a diagonal pattern can be formed. In order to effectively prevent appearance defects of the polarizing film finally obtained, the pattern formed on the surface of the gravure roll is preferably a honeycomb mesh pattern. In the case of a honeycomb mesh pattern, in order to improve the surface accuracy of the coated surface after the easy-adhesive composition is applied, the cell volume is preferably 1 to 5 cm ³ /m ² , more preferably 2 to 3 cm ³ /m ² . Similarly, in order to improve the surface accuracy of the coated surface after the easy-adhesive composition is applied, the number of unit lines per 1 inch of the roll is preferably 200 to 3000 lines/inch. In addition, the rotation speed of the gravure roller is preferably 100% to 300% with respect to the traveling speed of the polarizer.

＜Drying step of easy-adhesive composition＞ In the manufacturing method of the polarizing film of the present invention, a polarizer with an easy-adhesive layer can be formed by applying an easy-adhesive composition on the bonding surface of the polarizer, or a polarizer with an easy-adhesive layer can be formed by applying the easy-adhesive composition on the adhesive surface of the polarizer. After the coating step, a drying step is provided as needed to form a polarizer with an easy-adhesive layer. The drying step can use steps known to those skilled in the art, such as an air drying step, a heating step, and a hot air drying step.

＜Fixing Steps＞ Through the adhesive composition and easy-adhesive composition applied as described above, the polarizer and the transparent protective film are bonded together. In the bonding step, the adhesive composition and the easy bonding composition are not cured, so they are mixed with each other by bonding, and in this state are cured in the next bonding step to form an adhesive Floor. The bonding of the polarizer and the transparent protective film can be performed using a roll laminator or the like.

＜Gluing step＞ After bonding the polarizer and the transparent protective film, irradiate active energy rays (electron beam, ultraviolet, visible light, etc.) to cure the adhesive composition, or the adhesive composition and the easy-adhesive composition to form an adhesive接剂层。 Adhesive layer. The irradiation direction of active energy rays (electron beam, ultraviolet rays, visible light, etc.) can be irradiated from any appropriate direction. It is preferable to irradiate from the side of the transparent protective film. If irradiated from the polarizer side, the polarizer may be degraded by active energy rays (electron beam, ultraviolet rays, visible light, etc.).

The irradiation conditions in the case of irradiating the electron beam may be any appropriate conditions as long as the above-mentioned adhesive composition can be cured. For example, the acceleration voltage of the electron beam irradiation is preferably 5kV~300kV, more preferably 10kV~250kV. When the accelerating voltage is less than 5kV, the electron beam may not reach the adhesive and the curing may be insufficient. If the accelerating voltage is greater than 300kV, the penetrating force through the sample may be too strong, which may cause damage to the transparent protective film and polarizer. Risk of injury. As the irradiation dose, it is 5 to 100 kGy, more preferably 10 to 75 kGy. When the irradiation dose is less than 5kGy, the curing of the adhesive will be insufficient. If it is more than 100kGy, it will damage the transparent protective film and polarizer, reduce the mechanical strength, yellowing, and fail to obtain the given optical properties.

The electron beam irradiation is usually carried out in an inert gas, and can be carried out in the atmosphere with a small amount of oxygen introduced as needed. Depending on the material of the transparent protective film, it is appropriate to introduce oxygen, and the surface of the transparent protective film that is in contact with the electron beam initially will cause oxygen obstruction, which can prevent damage to the transparent protective film, and can efficiently irradiate the electron beam to the adhesive only.

In the manufacturing method of the polarizing film of the present invention, as the active energy ray, it is preferable to use an active energy ray including visible light having a wavelength range of 380 nm to 450 nm, particularly an active energy ray having the largest irradiation amount of visible light having a wavelength range of 380 nm to 450 nm. In the case of using ultraviolet light, visible light, and using a transparent protective film (UV non-transmissive transparent protective film) with ultraviolet absorbing ability, it absorbs light with a wavelength shorter than 380nm, so light with a wavelength shorter than 380nm will not reach The adhesive composition does not contribute to its polymerization reaction. In addition, the light with a wavelength shorter than 380 nm absorbed by the transparent protective film is converted into heat, and the transparent protective film generates heat by itself, which causes defects such as curling and wrinkles of the polarizing film. Therefore, in the present invention, in the case of using ultraviolet and visible light, it is preferable to use a device that does not emit light with a wavelength shorter than 380nm as the active energy ray generating device. More specifically, the cumulative illuminance in the wavelength range of 380~440nm and The ratio of the cumulative illuminance in the wavelength range of 250~370nm is preferably 100:0~100:50, more preferably 100:0~100:40. In the manufacturing method of the polarizing film of the present invention, as the active energy rays, a metal halide lamp encapsulated with gallium and an LED light source emitting light in the wavelength range of 380 to 440 nm are preferable. Or you can use low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, incandescent lamp, xenon lamp, halogen lamp, carbon arc lamp, metal halide lamp, fluorescent lamp, tungsten lamp, gallium lamp, excimer Light sources containing ultraviolet and visible light, such as lasers or sunlight, can also be used after blocking ultraviolet rays with a wavelength shorter than 380nm with a band-pass filter. In order to improve the adhesion performance of the adhesive layer between the polarizer and the transparent protective film, and to prevent the polarizing film from curling, it is better to use a metal halide lamp encapsulated with gallium, and to use a lamp that can block wavelengths shorter than 380nm. Active energy rays obtained by a light band-pass filter, or active energy rays with a wavelength of 405 nm obtained by using an LED light source.

It is preferable to heat the adhesive composition before irradiating ultraviolet rays or visible light (heating before irradiation). In this case, heating to 40°C or higher is preferable, more preferably 50°C or higher. In addition, it is also preferable to heat the active energy ray-curable adhesive composition after irradiating it with ultraviolet rays or visible light (heating after irradiation). In this case, it is preferable to heat to 40°C or higher, more preferably to 50°C or higher.

The adhesive composition used in the present invention can be suitably used particularly when forming an adhesive layer formed by bonding a polarizer and a transparent protective film with a light transmittance of less than 5% at a wavelength of 365 nm. Here, the adhesive composition used in the present invention can be cured to form an adhesive layer by irradiating ultraviolet rays through a transparent protective film having UV absorption capability by containing the photopolymerization initiator of the above-mentioned general formula (3). Therefore, even for a polarizing film having a transparent protective film with UV absorbing ability on the two area layers of the polarizing member, the adhesive layer can be cured. However, of course, it is also possible to cure the adhesive layer for a polarizing film laminated with a transparent protective film that does not have UV absorbing ability. It should be noted that a transparent protective film with UV absorption capability refers to a transparent protective film with a transmittance of less than 10% to 380 nm light.

As a method of imparting UV absorbing ability to a transparent protective film, a method of containing an ultraviolet absorber in a transparent protective film, and a method of containing a surface treatment layer of an ultraviolet absorber in the surface area of the transparent protective film can be cited.

Specific examples of ultraviolet absorbers include, for example, conventionally known oxybenzophenone-based compounds, benzotriazole-based compounds, salicylate-based compounds, benzophenone-based compounds, and cyanoacrylates. Compounds, nickel complex salt compounds, triazine compounds, etc.

When the polarizing film of the present invention is manufactured on a continuous production line, the linear speed varies depending on the curing time of the adhesive composition, and is preferably 1 to 500 m/min, more preferably 5 to 300 m/min, and still more preferably 10 to 100m/min. If the line speed is too low, the productivity is insufficient, or the damage to the transparent protective film is too large, and it is impossible to produce a polarizing film that can withstand durability tests. When the line speed is too high, the curing of the curable resin composition may become insufficient, and the target adhesiveness may not be obtained.

＜Optical film＞ The polarizing film manufactured by the manufacturing method of the present invention can be used as an optical film laminated with other optical layers in practical use. The optical layer is not particularly limited. For example, retardation films (including 1/2, 1/4 wave plates), visual compensation films, brightness enhancement films, reflection plates, and anti-transmission plates can be used in liquid crystal displays. The optical film of the optical layer used in the formation of devices.

As the above-mentioned retardation film, a retardation film having a frontal retardation of 40 nm or more and/or a thickness direction retardation of 80 nm or more can be used. The frontal retardation is usually controlled in the range of 40 to 200 nm, and the thickness direction retardation is usually controlled in the range of 80 to 300 nm.

Examples of retardation plates include: birefringent films obtained by uniaxially or biaxially stretching polymer materials, alignment films of liquid crystal polymers, and retardation films obtained by supporting an alignment layer of liquid crystal polymers. Board and so on. The thickness of the retardation film is also not particularly limited, and it is generally about 20 to 150 μm.

As the retardation film, a reverse wavelength dispersion type retardation film that satisfies the following formulas (1) to (3) can be used: 0.70＜Re[450]/Re[550]＜0.97・・・(1) 1.5×10 ^-3 ＜Δn＜6×10 ^-3・・・(2) 1.13＜NZ＜1.50・・・(3) (where, Re[450] and Re[550] are used at 23℃ with wavelength 450nm and The in-plane retardation value of the retardation film measured by 550nm light, Δn is the nx-ny when the retardation film's retardation axis direction and the advance axis direction are set to nx and ny respectively, that is, the in-plane double Refraction, NZ is the ratio of nx-nz to nx-ny when nz is the refractive index in the thickness direction of the retardation film, where nx-nz is thickness direction birefringence and nx-ny is in-plane birefringence).

The above-mentioned polarizing film and the optical film in which at least one layer of polarizing film is laminated may also be provided with an adhesive layer for bonding with other members such as a liquid crystal cell. The adhesive forming the adhesive layer is not particularly limited. For example, acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyethers, fluorines, rubbers, and other polymers can be appropriately selected as the base polymer. The adhesive of the object is used. In particular, it is preferable to use acrylic adhesives that have excellent optical transparency, exhibit moderate wettability, agglomeration, and adhesive properties such as adhesive properties, and are excellent in weather resistance, heat resistance, and the like.

The adhesive layer may be provided on one side or both sides of a polarizing film or an optical film in the form of an overlapping layer of layers of different compositions or types. In addition, when it is provided on both sides, adhesive layers of different compositions, types, thicknesses, etc. may be formed on the front and back surfaces of the polarizing film and the optical film. The thickness of the adhesive layer can be appropriately determined according to the purpose of use, adhesion, etc., and is usually 1 to 500 μm, preferably 1 to 200 μm, and particularly preferably 1 to 100 μm.

Until the exposed surface of the adhesive layer is put into actual use, for the purpose of preventing its contamination, etc., it is temporarily covered with a membrane by adhesive. This can prevent contact with the adhesive layer in a normal processing state. As the separator, in addition to the above-mentioned thickness conditions, suitable release agents such as silicones, long-chain alkyls, fluorines, molybdenum sulfide, etc. can be used as needed, such as plastic films, rubber sheets, paper, cloth, non-woven fabrics, etc. A separator obtained by coating a suitable thin layer body such as a net, a foamed sheet, a metal foil, and a laminate of these, etc., is a conventionally prescribed suitable separator such as a separator.

＜Image display device＞ The polarizing film or optical film of the present invention can be preferably used for the formation of various devices such as liquid crystal display devices. The formation of the liquid crystal display device can be performed according to a conventional method. That is, the liquid crystal display device is generally formed by appropriately assembling the liquid crystal cell, the polarizing film or the optical film, and the component parts such as the illumination system used as needed, and incorporating the driving circuit, etc. In the present invention, except for the use of the present invention It is not particularly limited except for a polarizing film or an optical film, and it can be carried out according to a conventional method. Regarding the liquid crystal cell, any type of liquid crystal cell, such as TN type, STN type, and π type, can be used.

Appropriate liquid crystal display devices, such as liquid crystal display devices with polarizing films or optical films arranged on one side or both sides of a liquid crystal cell, and liquid crystal display devices using backlights or reflectors in lighting systems, can be formed. In this case, the polarizing film or optical film of the present invention may be arranged 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. Furthermore, when the liquid crystal display device is formed, one layer or two or more layers such as diffuser, anti-glare layer, anti-reflection film, protective plate, scallop array, lens array sheet, light diffuser, etc. can be arranged at a suitable position. Suitable parts such as backlights. Example

Examples of the present invention are described below, but the embodiments of the present invention are not limited to these.

＜Polarizers＞ First, a laminate with a 9μm thick PVA layer formed on an amorphous PET substrate was assisted by stretching in a gas atmosphere at a stretching temperature of 130°C to form a stretched laminate. Next, the stretched laminate was borrowed The colored layered body is formed by dyeing, and the colored layered body is further stretched by stretching in a boric acid aqueous solution at a stretching temperature of 65 degrees so that the total stretching ratio becomes 5.94 times and is stretched integrally with the amorphous PET substrate to form An optical film laminate containing a 5 μm thick PVA layer. By such two-step stretching, an optical film laminate including a PVA layer with a thickness of 5 μm that constitutes a thin polarizer can be obtained. The PVA molecules of the PVA layer formed on the amorphous PET substrate of the thin polarizer are formed. High-order orientation, and the iodine adsorbed by dyeing is high-order aligned in one direction in the form of a polyiodide ion complex.

＜Transparent protective film＞ As the transparent protective film, a triacetate cellulose (TAC) film (product name: KC2UA, thickness: 25 μm) manufactured by Konica Minolta Co., Ltd. was used.

<Active energy rays> As active energy rays, visible light (metal halide lamp enclosed with gallium) is used. Irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., valve: V valve, peak illuminance: 1600 mW/cm ² , cumulative Irradiation is 1000/mJ/cm ² (wavelength 380~440nm). It should be noted that the illuminance of visible light was measured using the Sola-Check system manufactured by Solarell.

(Preparation of adhesive composition) When the total amount of radical polymerizable compounds in the composition is 100% by mass, acrylomorpholine (trade name "ACMO", manufactured by Koto Co., Ltd.), which is a radical polymerizable compound, is used as a radical 1,9-nonanediol diacrylate of a polymerizable compound (trade name "LIGHT ACRYLATE 1,9-NDA (described in Table 1 as "1,9-NDA")", manufactured by Kyoeisha Chemical Co., Ltd.), Diethyl thioxanthone (compound described in general formula (3), trade name "KAYACURE DETX-S (described in Table 1 as "DETX-S")" as a photopolymerization initiator, manufactured by Nippon Kayaku Co., Ltd. , 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (compound described in general formula (4), trade name "IRGACURE 907( It is described as "907")" in Table 1, manufactured by BASF Corporation) and mixed at the blending ratio described in Table 1, and then stirred at 50°C for 1 hour to prepare the viscosities used in the examples and comparative examples. Gel composition. The method of estimating the SP value of the adhesive composition will be described later.

(Preparation of easy bonding composition) When the total amount of the composition is 100% by mass, 4-vinylbenzeneboronic acid (manufactured by Junsei Chemical Co., Ltd.) as the compound described in the general formula (1) and acrylomorpholine as a radically polymerizable compound (Trade name "ACMO", manufactured by Koto Co., Ltd.) and pure water were mixed at the blending ratio described in Table 1, and then stirred at 50°C for 1 hour to prepare the examples and comparative examples. The easy bonding composition. The method of estimating the SP value of the easy-adhesive composition will be described later.

(The application step of the easy-adhesive composition) Using a gravure roll coating method equipped with a gravure roll, the PVA surface of the optical film laminate containing a 5μm thick PVA layer of the above-mentioned polarizer was coated with the easy-adhesive composition described in Table 1, and dried at 25°C with hot air 1 Minutes, thus fabricating a polarizer with easy-adhesive layer. Table 1 shows the thickness before drying (Wet thickness) when the easy-adhesive composition was applied in the coating step of each Example and Comparative Example.

(Manufacturing of Polarizing Film) Examples 1~2 and Comparative Examples 1~2 Using an MCD coater (manufactured by Fuji Machine Co., Ltd.) (cell shape: honeycomb, number of gravure rolls: 1000 lines/inch, rotation speed 140%/pair line speed), the above-mentioned bonding was applied to the bonding surface side of the transparent protective film The composition was adjusted to the thickness before drying (Wet thickness) described in Table 1, and an uncured adhesive layer was formed. Next, a roll machine was used to bond the transparent protective film from the easy-adhesive layer side of the polarizer with the easy-adhesive layer. Then, use an active energy ray irradiation device to irradiate the above-mentioned visible light from the side of the laminated transparent protective film to bond the polarizer and the transparent protective film, and then dry it with hot air at 70°C for 3 minutes, and laminate it on the other side of the polarizer. The amorphous PET substrate on the side was peeled and removed, thereby obtaining a polarizing film having a transparent protective film on one side of the polarizer. The bonding was performed at a linear speed of 25m/min.

<Method for estimating SP value of adhesive composition and easy-adhesive composition> The SP value of the adhesive composition and the easy-adhesive composition are calculated as follows: For the constituent materials of the composition, the Hansen Solubility Parameter in Practice (HSPiP) Y-MB method is used to calculate the Hansen Solubility Parameter (SP). Value), calculated from the average value of the volume ratio in the composition. It should be noted that, regarding the easy-adhesive composition, the SP value was calculated for constituent materials other than pure water.

＜Method for estimating SP value of adhesive layer＞ Regarding the SP value of the adhesive layer, the solubility parameter (SP value) of Hansen was calculated by averaging the SP value of the adhesive composition and the SP value of the easy-adhesive composition based on the respective volume ratios.

＜Measuring method of SP value of transparent protective film＞ The transparent protective film is immersed in 14 solvents with different solubility, namely water, acetone, cyclopentanone, isopropanol, ethanol, methanol, toluene, p-xylene, cyclohexane, n-hexane, ethyl acetate, trichlorobenzene , Anisole and their mixed solvents for 10 minutes. The condition of the transparent protective film after 10 minutes of immersion is classified into three levels of (1) dissolution, (2) swelling, and (3) insoluble. Based on the solubility information for each solvent thus obtained, Hansen Solubility Parameter in Practice (HSPiP) ver.4.1.07 (http://www.hansen-solubility.com/index.php) was used to calculate the Hansen Solubility Parameter ( SP value).

＜Between the SP value of the transparent protective film and the SP value of the adhesive composition (or the average SP value calculated based on the volume ratio of the SP value of the adhesive composition and the SP value of the easy-adhesive composition) SP value distance> Set the dispersion term of the Hansen solubility parameter of the transparent protective film to σd, the polarity term to σp, the hydrogen bond term to σh, and the Hansen solubility parameter of the adhesive composition (or based on When the average Hansen’s solubility parameter calculated by the volume ratio of the adhesive composition and the easy-adhesive composition is set to σAd, the polar term is set to σAp, and the hydrogen bond term is set to σAh, The following mathematical formula: Ra=[4×(σd－σAd) ² + 2×(σp－σAp) ² ＋2×(σh－σAh) ² ] ^1/2 =[4×(σd－σAd) ² ＋2×(σp －ΣAp) ² ＋2×(σh－σAh) ² ] ^{1/2 is} defined as "the SP value of the transparent protective film and the SP value of the adhesive composition (or the SP value of the adhesive composition and the easy-adhesive composition The SP value of the average SP value) between the SP value distance". The Hansen solubility parameters of the transparent protective film and adhesive composition (or adhesive layer) calculated by the above method were used for calculation.

(Peeling force (initial adhesion)) The obtained polarizing film was cut out to a size of 200 mm in a direction parallel to the stretching direction of the polarizer and 15 mm in the orthogonal direction, and the polarizing film was bonded to a glass plate. Then, cut an incision between the transparent protective film and the polarizer with a cutter, and use a universal tensile machine to peel the protective film and the polarizer in a 90-degree direction at a peeling speed of 300m/min. The peel strength (N/15mm) was measured. .

(Observation of the presence or absence of bubbles in the polarizing film) Illuminate the polarizing film with a fluorescent lamp, and observe whether there are bubbles with the naked eye. As described in Table 1, no bubbles were observed in the polarizing films produced in Examples 1 to 2 and Comparative Example 2, but in Comparative Example 1, a large number of bubbles were observed across the entire surface of the polarizing film.

Table 1

(no)

Claims (4)

A method for manufacturing a polarizing film, wherein at least one surface of the polarizing film is provided with a transparent protective film via an adhesive layer, the method comprising: In the first coating step, an adhesive composition is applied to the bonding surface of the transparent protective film; The second coating step is to coat the easy-adhesive composition on the bonding surface of the polarizer; In the bonding step, bonding the polarizer and the transparent protective film; and In the bonding step, active energy rays are irradiated from the surface of the polarizer or the surface of the transparent protective film to cure the adhesive composition and the easy-adhesive composition to obtain an adhesive layer, thereby separating the adhesive The adhesive layer adheres the polarizer and the transparent protective film, The SP value distance between the SP value of the transparent protective film and the SP value of the adhesive composition is 5.3 or more, and is based on the SP value of the adhesive composition and the easy-adhesive composition The SP value distance between the average SP value calculated from the volume ratio of each SP value and the SP value of the transparent protective film is 5.8 or less. The method for manufacturing a polarizing film of claim 1, wherein the easy-adhesive composition contains a compound represented by the following general formula (1):

In the formula, X is a functional group containing a reactive group, R ¹ and R ² each independently represent a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group which may also have a substituent, and a reactive group contained in X It is selected from the group consisting of vinyl, (meth)acryloyl, styryl, (meth)acrylamido, vinyl ether, epoxy, oxetanyl and mercapto groups Of at least one reactive group. The method for producing a polarizing film according to claim 2, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (1'):

In the formula, Y is an organic group, X'is a reactive group contained in X, and R ¹ and R ² are the same as defined above. The method for producing a polarizing film according to claim 2, wherein the easy-adhesive composition contains a radical polymerizable compound represented by the following general formula (2):

In the formula, R ³ is a hydrogen atom or a methyl group, R ⁴ and R ⁵ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group or a cyclic ether group. R ⁴ and R ⁵ may also be formed Cyclic heterocycle.