WO2022071387A1

WO2022071387A1 - Polarizing film, optical film, and image display device

Info

Publication number: WO2022071387A1
Application number: PCT/JP2021/035849
Authority: WO
Inventors: 泰介笹川; 達也山崎
Original assignee: 日東電工株式会社
Priority date: 2020-09-30
Filing date: 2021-09-29
Publication date: 2022-04-07
Also published as: TW202219564A; CN115867836A; KR20230071099A; JP2022058231A

Abstract

Provided is a polarizing film excelling in humidification reliability even in a harsh, high temperature, high humidity environment.　The polarizing film is provided with an iodine-based polarizer and an adjacent layer on at least one side of the iodine-based polarizer, and has an HSP distance of 26 or greater between the adjacent layer and water. The adjacent layer preferably includes a barrier layer having a moisture permeability of 500 g/(m²•24 h) or less. In addition, the thickness of the barrier layer is preferably 1 μm or greater. The adjacent layer is also preferably provided with a barrier layer with an adhesive layer, which directly contacts the iodine-based polarizer, interposed therebetween.

Description

Polarizing film, optical film and image display device

The present invention relates to a polarizing film provided with an iodine-based polarizing element and an adjacent layer on at least one side of the iodine-based polarizing element. The polarizing film may form an image display device such as a liquid crystal display device (LCD), an organic EL display device, a CRT, or a PDP as an optical film obtained by itself or in which the polarizing film is laminated.

In various image display devices, a polarizing film is used for image display. For example, in a liquid crystal display (LCD), it is indispensable to arrange polarizing films on both sides of a glass substrate forming a liquid crystal panel surface due to its image forming method. Further, in the organic EL display device, in order to shield the specular reflection of external light by the metal electrode, a circularly polarizing film in which a polarizing film and a 1/4 wave plate are laminated is arranged on the visual recognition side of the organic light emitting layer.

As the polarizing film, generally, a film in which a protective film is bonded to one side or both sides of a polyvinyl alcohol-based film and a polarizing element made of a dichroic material such as iodine with various adhesives or the like is used. .. As the adhesive, for example, a radical polymerization type active energy ray-curable adhesive using an N-substituted amide-based monomer as a curable component has been proposed (Patent Documents 1 and 2 below). Such an adhesive exhibits excellent humidification reliability in a harsh environment under high humidity and high temperature, but the market is demanding an adhesive capable of further improving the humidification reliability. It was the actual situation.

Further, paying attention to the SP value (solubility parameter) of the curable component, at least three kinds of radically polymerizable compounds having different SP values are used in a predetermined composition ratio to obtain an adhesive layer having improved humidification reliability. An active energy ray-curable adhesive that can be formed has been proposed (Patent Document 3 below).

The polarizing film is required to have not only humidification reliability but also excellent resistance to a harsh environment of thermal shock (for example, a heat shock test in which temperature conditions of -30 ° C and 80 ° C are repeated). In some cases. For example, Patent Document 4 below describes a polarizing film having a polarizing element and a protective film layer formed on at least one surface of the polarizing element, and the thickness of the protective film layer is set to 0.5 μm or less. There is.

Japanese Unexamined Patent Publication No. 2008-287207 Japanese Unexamined Patent Publication No. 2010-078700 Japanese Unexamined Patent Publication No. 2012-144690 International Publication No. 2018-101204

According to the active energy ray-curable adhesive described in Patent Document 3, the humidification reliability can be satisfied with respect to various transparent protective films used in the production of the polarizing film. However, although the polarizing film obtained by using the active energy ray-curable adhesive described in Patent Document 3 can satisfy the water resistance (warm water immersion test) when immersed in warm water at 60 ° C. for 6 hours. In the market, humidification reliability in a harsh environment under further high temperature and high humidity has been required.

The polarizing film described in Patent Document 4 is developed for the purpose of improving heat shock resistance in response to a request for thinning of the polarizing film, and is developed for the purpose of improving humidification reliability. is not. Furthermore, Patent Document 4 does not contain any description or suggestion regarding the mechanism of effect manifestation of the present invention, which will be described later.

The present invention has been developed in view of the above circumstances, and an object of the present invention is to provide a polarizing film having excellent humidification reliability even in a harsh environment under high temperature and high humidity.

The above problem can be solved by the following configuration. That is, the present invention relates to a polarizing film comprising an iodine-based polarizing element and an adjacent layer on at least one surface of the iodine-based polarizing element, and the HSP value distance between the adjacent layer and water is 26 or more.

In the polarizing film, it is preferable that the adjacent layer includes a barrier layer having a moisture permeability of 500 g / ( ^m 2.24 h) or less.

In the polarizing film, the thickness of the barrier layer is preferably 1 μm or more.

In the polarizing film, it is preferable that the adjacent layer includes the barrier layer via an adhesive layer that is in direct contact with the iodine-based polarizing element.

In the polarizing film, it is preferable that the adjacent layer includes the barrier layer via an adhesive layer formed on the easy-adhesive layer that is in direct contact with the iodine-based polarizing element.

In the polarizing film, the ratio (Tb / Ta) of the thickness Tb of the barrier layer to the thickness Ta of the adhesive layer is preferably 0.05 to 50.

In the polarizing film, it is preferable to further include a resin film laminated on the surface of the iodine-based polarizing element on the side of the adjacent layer.

In the polarizing film, the moisture permeability of the resin film is preferably 80 g / ( ^m 2.24 h) or more.

Further, the present invention comprises an optical film in which at least one polarizing film according to any one of the above is laminated, a polarizing film according to any one of the above, or an image including the optical film according to the above. Regarding display devices.

The polarizing film according to the present invention is provided with an adjacent layer having an HSP value distance of 26 or more from water on at least one side of the iodine-based polarizing element. As a result, the polarizing film according to the present invention is excellent in humidification reliability even in a harsh environment under high temperature and high humidity. The reason why such an excellent effect is obtained is not clear, but it can be estimated as follows.

In a polarizing film equipped with an iodine-based polarizing element, the amount of change in the single transmittance and the amount of change in the degree of polarization of the polarizing film are both large due to the escape of iodine from the iodine-based polarizing element to the outer layer, especially under high temperature and high humidity. Tend to be. The present inventor focused on this tendency and tried to find the cause. It was newly found that iodine escapes from the iodine-based polarizing element to the outer layer together with water in a form in which iodine is attracted to water. As a result of examining this mechanism in detail, the present inventor suppresses iodine loss from the iodine-based polarizing element by providing an adjacent layer having an HSP value distance of 26 or more from water on at least one surface of the iodine-based polarizing element. However, it has been found that the humidification reliability can be dramatically improved even in a harsh environment under high temperature and high humidity.

In particular, in the polarizing film according to the present invention, a barrier layer having a moisture permeability of 500 g / ( ^m 2.24 h) or less is included as an adjacent layer, and the thickness of the barrier layer is set to 1 μm or more so that the polarizing film can be used. Iodine escape is remarkably suppressed, and humidification reliability can be further dramatically improved even in a harsh environment under high temperature and high humidity.

The polarizing film according to the present invention may be a film in which a resin film is laminated on the surface of the iodine-based polarizing element on the adjacent layer side, and particularly when the moisture permeability of the resin film is 80 g / ( ^m 2.24 h) or more. There may be. A resin film having a water permeability of 80 g / ( ^m 2.24 h) or more is particularly easy to pass water under high temperature and high humidity, and as described above, if it is a normal polarizing film, iodine is removed from the iodine-based polarizing element. Is likely to occur. However, since the polarizing film according to the present invention is provided with an adjacent layer having an HSP value distance of 26 or more from water on at least one surface of the iodine-based polarizing element, iodine escape from the iodine-based polarizing element is suppressed, and the temperature is high. Humidity reliability is dramatically improved even in harsh environments under wet conditions.

The polarizing film according to the present invention includes an iodine-based polarizing element and an adjacent layer on at least one surface of the iodine-based polarizing element.

<Iodine-based splitter>
The iodine-based splitter (hereinafter, also simply referred to as “polarizer” or “thin-thin deflector”) is not particularly limited, and various types can be used. Examples of the splitter include a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, and an ethylene-vinyl acetate copolymer partially saponified film, which is uniaxially stretched by adsorbing iodine. Can be mentioned. Examples of the thickness of the splitter include 3 to 20 μm.

However, in the present invention, from the viewpoint of improving humidification reliability in a harsh environment under high temperature and high humidity, it is preferable to use a thin polarizing element having a thickness of 3 μm or more and 15 μm or less as the polarizing element. 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 polarizing element has little unevenness in thickness, is excellent in visibility, and is excellent in durability against thermal shock because there is little dimensional change.

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

It is preferable that the polarizing element contains boric acid from the viewpoint of stretching stability and humidification reliability. Further, the boric acid content contained in the polarizing element is preferably 22% by mass or less, more preferably 20% by mass or less, based on the total amount of the polarizing element, from the viewpoint of suppressing the generation of through cracks. From the viewpoint of stretching stability and humidification reliability, the boric acid content with respect to the total amount of the substituents is preferably 10% by mass or more, more preferably 12% by mass or more.

As a thin polarizing element, a typical example is
Japanese Patent No. 4751486,
Japanese Patent No. 4751481,
Japanese Patent No. 4815544,
Japanese Patent No. 5048120,
International Publication No. 2014/07759 Pamphlet,
International Publication No. 2014/077663 Pamphlet,
And the like, or the thin polarizing element obtained from the manufacturing method described in these can be mentioned.

The thin polarizing element can be stretched at a high magnification and can improve the polarization performance even in a manufacturing method including a step of stretching in a laminated state and a step of dyeing. It is preferably obtained by a production method including a step of stretching in a boric acid aqueous solution as described in Japanese Patent No. 4751481 and Japanese Patent No. 4815544, and particularly described in Japanese Patent No. 4751481 and Japanese Patent No. 4815544. It is preferably obtained by a production method including a step of auxiliary stretching in the air before stretching in a certain boric acid aqueous solution. These thin splitters can be obtained by a manufacturing method including a step of stretching a polyvinyl alcohol-based resin (hereinafter, also referred to as PVA-based resin) layer and a stretching resin base material in a laminated state and a step of dyeing. With this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without any trouble such as breakage due to stretching because it is supported by the stretching resin base material.

<Adjacent layer>
The polarizing film according to the present invention is characterized in that it is provided with an adjacent layer on at least one surface of an iodine-based polarizing element, and the HSP value distance between the adjacent layer and water is 26.0 or more. First, the calculation method of the HSP value (solubility parameter) will be described below.

(Calculation method of solubility parameter (HSP value distance))
In the present invention, the solubility parameter (HSP value distance) of the adjacent layer is a Hansen calculation method [using the HSPiP version 4.1.07 calculation software], that is, the Hansen solubility parameter 1967. It is a value used for predicting the solubility of a substance announced by Hansen.

The Hansen solubility parameter is composed of the following three parameters.
-ΔD: Energy due to the dispersion force between molecules-δP: Energy due to dipole interaction between molecules-δH: Energy due to hydrogen bonds between molecules These three parameters can be regarded as coordinates in three-dimensional space. The affinity between two substances (eg, water and adjacent layer) can be evaluated by the distance between the two HSP values (HSP value distance), and the affinity when the HSP value distance between the two substances is small. Can be said to be large.

The HSP value distance calculation formula used as an index this time is a value calculated by substituting the above three components of Hansen of two substances into the following formula.

In the present invention, the adjacent layer provided on at least one surface of the iodine-based polarizing element preferably has an HSP distance of 26 or more, more preferably 27 or more, and even more preferably 28 or more.

In the present invention, an adjacent layer having an HSP distance of 26 or more may be provided on only one side of the iodine-based polarizing element, but in particular, both sides of the iodine-based polarizing element have an HSP distance of 26 or more. When the adjacent layer is provided, it is preferable because the humidification reliability is particularly excellent even in a harsh environment under high temperature and high humidity.

The adjacent layer may be provided with, for example, an adhesive layer and a barrier layer having a moisture permeability of 500 g / ( ^m 2.24 h) or less on at least one surface of the polarizing element. In this case, for example, a barrier layer may be formed on the adhesive layer that is in direct contact with the iodine-based polarizing element. When the adjacent layer is composed of an adhesive layer and a barrier layer, the HSP value distance of the adjacent layer from water can be calculated as follows.
(Thickness ratio of adhesive layer to adjacent layer) x (HSP value distance of adhesive layer to water) + (Thickness ratio of barrier layer to adjacent layer) x (HSP value distance to water of barrier layer)

<Barrier layer>
In particular, in the polarizing film according to the present invention, a barrier layer having a moisture permeability of 500 g / ( ^m 2.24 h) or less is included as an adjacent layer, and the thickness of the barrier layer is set to 1 μm or more so that the polarizing film can be used. Iodine escape is remarkably suppressed, and humidification reliability can be further dramatically improved even in a harsh environment under high temperature and high humidity. Examples of the resin component constituting the barrier layer include polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate resins; allylate resins; amide resins such as nylon and aromatic polyamides; polyethylene, polypropylene, and ethylene / propylene copolymers. It is preferable that the barrier layer is composed of a polyethylene-based polymer such as, a cyclo-based or cyclic olefin-based resin having a norbornene structure, a (meth) acrylic-based resin, or a mixture thereof. In particular, in the present invention, the resin constituting the barrier layer is preferably a polycarbonate-based resin, a cyclic polyolefin-based resin, or a (meth) acrylic-based resin, and particularly preferably a cyclic polyolefin-based resin.

Regarding the thickness Tb of the barrier layer, the lower limit is particularly preferably 0.75 μm, and particularly preferably 1 μm. By designing the lower limit of the thickness of the barrier layer as described above, it is possible to improve the humidification reliability in a harsh environment under high temperature and high humidity. The upper limit of the thickness of the barrier layer is, for example, about 3 μm, and more preferably about 1 μm, from the viewpoint of requesting the thinning of the polarizing film.

<Adhesive layer>
The adjacent layer having an HSP value distance of 26 or more with water may be composed of only an adhesive layer that is in direct contact with the iodine-based polarizing element, and a barrier layer is formed on the adhesive layer that is in direct contact with the iodine-based polarizing element. It may be composed of a single material, or a barrier layer may be formed on an adhesive layer that is in direct contact with an iodine-based polarizing element, and an adhesive layer may be further formed on the barrier layer. Further, the adhesive layer may be formed so as to be in direct contact with the iodine-based polarizing element, or may be formed on an easy-adhesive layer that is in direct contact with the iodine-based polarizing element. The easy-adhesive layer will be described later.

Regardless of whether the adhesive layer constituting the adjacent layer is one layer or two or more layers, the adhesive layer thickness Ta per layer is preferably 0.1 to 10 μm, and is 0. It is preferably .5 to 5 μm.

From the viewpoint of improving the humidification reliability of the polarizing film by the adjacent layer, the ratio (Tb / Ta) of the thickness Tb of the barrier layer to the thickness Ta of the adhesive layer is preferably 0.05 to 50, preferably 1 to 10. It is more preferable to have.

The adhesive composition used as a raw material for the adhesive layer of the present invention contains at least a curable component. It is preferable that the curable component is appropriately selected so that the HSP value distance of the cured adhesive layer from water is 25 or more and 27 or less.

The curable component can be roughly classified into an active energy ray curable type such as an electron beam curable type, an ultraviolet curable type, and a visible light curable type, and a thermosetting type. Further, the ultraviolet curable type adhesive and the visible light curable type adhesive can be classified into a radical polymerization curable type adhesive and a cationic polymerization type adhesive. In the present invention, active energy rays having a wavelength range of 10 nm to less than 380 nm are referred to as ultraviolet rays, and active energy rays having a wavelength range of 380 nm to 800 nm are referred to as visible light. The curable component of the radical polymerization curable adhesive can be used as a curable component of the thermosetting adhesive.

Examples of the curable component include radically polymerizable compounds used in radical polymerization curable adhesives. Examples of the radically polymerizable compound include compounds having a radically polymerizable functional group of a carbon-carbon double bond such as a (meth) acryloyl group and a vinyl group. As these curable components, either a monofunctional radical-polymerizable compound or a bifunctional or higher-functional polyfunctional radical-polymerizable compound can be used. In addition, these radically polymerizable compounds may be used alone or in combination of two or more. As these radically polymerizable compounds, for example, compounds having a (meth) acryloyl group are suitable. In addition, in this invention, (meth) acryloyl means acryloyl group and / or methacryloyl group, and "(meth)" has the same meaning below.

Examples of the monofunctional radically polymerizable compound include (meth) acrylamide derivatives having a (meth) acrylamide group. The (meth) acrylamide derivative is preferable in terms of ensuring adhesiveness to a polarizing element and various transparent protective films, and also in terms of high polymerization rate and excellent productivity. Specific examples of the (meth) acrylamide derivative include, for example, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, and N. -N-alkyl group-containing (meth) acrylamide derivatives such as butyl (meth) acrylamide and N-hexyl (meth) acrylamide; N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N-methylol-N- N-hydroxyalkyl group-containing (meth) acrylamide derivatives such as propane (meth) acrylamide; N-aminoalkyl group-containing (meth) acrylamide derivatives such as aminomethyl (meth) acrylamide and aminoethyl (meth) acrylamide; N-methoxymethyl N-alkoxy group-containing (meth) acrylamide derivatives such as acrylamide and N-ethoxymethylacrylamide; N-mercaptoalkyl group-containing (meth) acrylamide derivatives such as mercaptomethyl (meth) acrylamide and mercaptoethyl (meth) acrylamide. Be done. Examples of the heterocyclic-containing (meth) acrylamide derivative in which the nitrogen atom of the (meth) acrylamide group forms a heterocycle include N-acrylloylmorpholine, N-acrylloylpiperidin, N-methacryloylpiperidin, and N-acrylloylpyrrolidine. And so on.

Further, examples of the monofunctional radically polymerizable compound include various (meth) acrylic acid derivatives having a (meth) acryloyloxy group. Specifically, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, 2-methyl-2-nitropropyl (meth) acrylate, n-butyl ( Meta) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, t-pentyl (meth) acrylate, 3-pentyl (meth) acrylate, 2,2-Dimethylbutyl (meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 4-methyl-2-propylpentyl ( Examples thereof include (meth) acrylic acid (1-20 carbon atoms) alkyl esters such as meth) acrylates and n-octadecyl (meth) acrylates.

Examples of the (meth) acrylic acid derivative include cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate and cyclopentyl (meth) acrylate; aralkyl (meth) acrylates such as benzyl (meth) acrylate; 2-isobornyl. (Meta) acrylate, 2-norbornylmethyl (meth) acrylate, 5-norbornen-2-yl-methyl (meth) acrylate, 3-methyl-2-norbornylmethyl (meth) acrylate, dicyclopentenyl (meth) ) Polycyclic (meth) acrylates such as acrylicate, dicyclopentenyloxyethyl (meth) acrylicate, dicyclopentanyl (meth) acrylicate, etc .; 2-methoxyethyl (meth) acrylate, 2-ethoxy Ethyl (meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, alkylphenoxypolyethylene glycol (meth) acrylate, etc. An alkoxy group- or phenoxy group-containing (meth) acrylate; and the like.

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

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

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

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

Examples of the bifunctional or higher polyfunctional radically polymerizable compound include tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9. -Nonandiol di (meth) acrylate, 1,10-decanediol diacrylate, 2-ethyl-2-butylpropanediol di (meth) acrylate, bisphenol A di (meth) acrylate, bisphenol A ethylene oxide adduct di (meth) ) Acrylate, bisphenol A propylene oxide adduct di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neopentyl glycol di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, cyclic tri Methylol propaneformal (meth) acrylate, dioxane glycol di (meth) acrylate, trimethylol propanetri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate. , Dipentaerythritol hexa (meth) acrylate, EO-modified diglycerin tetra (meth) acrylate or other (meth) acrylic acid and polyhydric alcohol esterified product, 9,9-bis [4- (2- (meth) acryloyl) Oxyethoxy) phenyl] fluorene can be mentioned. Specific examples include Aronix M-220, M-306 (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- Examples thereof include A (manufactured by Kyoeisha Chemical Co., Ltd.), SR-531 (manufactured by Sartomer), and CD-536 (manufactured by Sartomer). Further, if necessary, various epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates, various (meth) acrylate-based monomers and the like can be mentioned.

The radically polymerizable compound is a combination of a monofunctional radically polymerizable compound and a polyfunctional radically polymerizable compound from the viewpoint of achieving both adhesion to a polarizing element and various transparent protective films and optical durability in a harsh environment. Is preferable. Usually, it is preferable to use the monofunctional radically polymerizable compound in a ratio of 30 to 90% by weight and the polyfunctional radically polymerizable compound in a ratio of 10 to 70% by weight with respect to 100% by weight of the radically polymerizable compound.

The curable adhesive for a polarizing film of the present invention is an active energy ray-curable adhesive when a curable component is used as an active energy ray-curable component, and a thermosetting component when a curable component is used as a thermosetting component. Can be used as a thermosetting adhesive. When an electron beam or the like is used for the active energy ray, the active energy ray-curable adhesive does not need to contain a photopolymerization initiator, but the active energy ray-curable adhesive can be used for the active energy ray. When ultraviolet rays or visible rays are used, it is preferable to contain a photopolymerization initiator. On the other hand, when the curable component of the adhesive is used as the thermosetting component, the adhesive preferably contains a thermopolymerization initiator.

When a radically polymerizable compound is used, the photopolymerization initiator is appropriately selected by the active energy ray. When curing with ultraviolet rays or visible light, a photopolymerization initiator for ultraviolet or visible light cleavage is used. Examples of the photopolymerization initiator include benzophenone compounds such as benzyl, benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone; 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2). -Aromatic ketone compounds such as (propyl) ketone, α-hydroxy-α, α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, α-hydroxycyclohexylphenylketone; methoxyacetophenone, 2,2-dimethoxy- Acetphenone compounds such as 2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1- [4- (methylthio) -phenyl] -2-morpholinopropane-1; benzophenone methyl ether, Benzophenone ether compounds such as venzoin ethyl ether, benzoin isopropyl ether, venzoin butyl ether and anisoin methyl ether; aromatic ketal compounds such as benzyl dimethyl ketal; aromatic sulfonyl chlorides such as 2-naphthalene sulfonyl chloride. System compounds; Photoactive oxime compounds such as 1-phenone-1,1-propanedione-2- (o-ethoxycarbonyl) oxime; thioxanthone, 2-chlorothioxanson, 2-methylthioxanson, 2,4- Thioxanthone compounds such as dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone; benzophenone; halogenated Examples thereof include ketones; acylphosphinoxides; acylphosphonates and the like.

The blending amount of the photopolymerization initiator is 20 parts by weight or less with respect to 100 parts by weight of the total amount of the curable component (radical polymerizable compound). The blending amount of the photopolymerization initiator is preferably 0.01 to 20 parts by weight, more preferably 0.05 to 10 parts by weight, and further preferably 0.1 to 5 parts by weight.

Further, when the curable adhesive for a polarizing film of the present invention is used in a visible light curable type containing a radically polymerizable compound as a curable component, a photopolymerization initiator having high sensitivity to light of 380 nm or more is used. It is preferable to use it. A photopolymerization initiator having high sensitivity to light of 380 nm or more will be described later.

The photopolymerization initiator is a compound represented by the following general formula (1);

(In the formula, R ¹ and R ² indicate -H, -CH ₂ CH ₃ , -iPr or Cl, and R ¹ and R ² may be the same or different), or the general formula (in the formula) may be used alone. It is preferable to use the compound represented by 1) in combination with a photopolymerization initiator having high sensitivity to light of 380 nm or more, which will be described later. When the compound represented by the general formula (1) is used, the adhesiveness is excellent as compared with the case where a photopolymerization initiator having high sensitivity to light of 380 nm or more is used alone. Among the compounds represented by the general formula (1), diethylthioxanthone in which R ¹ and R ² are −CH ₂ CH ₃ is particularly preferable. The composition ratio of the compound represented by the general formula (1) in the curable resin composition is preferably 0.1 to 5% by weight, preferably 0.5 to 5% by weight, based on the total amount of the curable resin composition. It is more preferably 4% by weight, still more preferably 0.9 to 3% by weight.

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

Further, a known photopolymerization initiator can be used in combination if necessary. Since the transparent protective film having a UV absorbing ability does not transmit light of 380 nm or less, it is preferable to use a photopolymerization initiator having high sensitivity to light of 380 nm or more as the photopolymerization initiator. Specifically, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 , 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine Oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (η5-2,4-cyclopentadiene-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-) 1-yl) -phenyl) titanium and the like can be mentioned.

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

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

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

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

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

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

The adhesive composition used in the present invention is, if necessary, a compound represented by the following general formula (3);

(However, X is a functional group containing a reactive group, and R ⁶ and R ⁷ are each independently having a hydrogen atom and a substituent, an aliphatic hydrocarbon group, an aryl group, or a heterocyclic group. Represents), preferably the compound according to the general formula (3');

(However, Y is an organic group, X'is a reactive group contained in X, and R ⁶ and R ⁷ are the same as described above), more preferably described in the general formulas (3a) to (3d) described later. Compound;

Can be incorporated into the adhesive composition. When these compounds are blended in the adhesive composition, the adhesiveness to the polarizing element and the transparent protective film may be improved, which is preferable. From the viewpoint of improving the adhesiveness and water resistance between the polarizing element and the transparent protective film, the content of the compound represented by the general formula (3) in the adhesive composition is 0.001 to 50% by mass. It is preferably 0.1 to 30% by mass, more preferably 1 to 10% by mass, and most preferably 1 to 10% by mass.

In the general formula (3), the aliphatic hydrocarbon group has a linear or branched alkyl group which may have a substituent having 1 to 20 carbon atoms and a substituent having 3 to 20 carbon atoms. Examples thereof include a cyclic alkyl group which may have a substituent and an alkenyl group having 2 to 20 carbon atoms, and examples of the aryl group include a phenyl group which may have a substituent having 6 to 20 carbon atoms and a substituent having 10 to 20 carbon atoms. Examples thereof include a naphthyl group which may have a naphthyl group, and examples of the heterocyclic group include a 5-membered ring or a 6-membered ring group which may have a substituent and which contains at least one hetero atom. These may be connected to each other to form a ring. In the general formula (3), R ⁶ and R ⁷ are preferably a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, and most preferably a hydrogen atom.

X contained in the compound represented by the general formula (3) is a functional group containing a reactive group, which is a functional group capable of reacting with a curable component constituting the adhesive layer, and is a reactive group contained in X. For example, hydroxyl group, amino group, aldehyde group, carboxyl group, vinyl group, (meth) acrylic group, styryl group, (meth) acrylamide group, vinyl ether group, epoxy group, oxetane group, α, β-unsaturated carbonyl. Groups, mercapto groups, halogen groups and the like can be mentioned. When the curable resin composition constituting the adhesive layer is active energy ray curable, the reactive group contained in X is a vinyl group, a (meth) acrylic group, a styryl group, a (meth) acrylamide group, a vinyl ether group, and the like. It is preferably at least one reactive group selected from the group consisting of an epoxy group, an oxetane group and a mercapto group, and particularly when the adhesive composition constituting the adhesive layer is radically polymerizable, X is contained. The reactive group is preferably at least one reactive group selected from the group consisting of a (meth) acrylic group, a styryl group and a (meth) acrylamide group, and the compound represented by the general formula (1) is preferable. When it has a (meth) acrylamide group, it is more preferable because it has high reactivity and the copolymerization rate with the active energy ray-curable resin composition increases. Further, since the (meth) acrylamide group has a high polarity and excellent adhesiveness, the effect of the present invention can be efficiently obtained, which is also preferable. When the curable resin composition constituting the adhesive layer is cationically polymerizable, the reactive group contained in X is composed of a hydroxyl group, an amino group, an aldehyde, a carboxyl group, a vinyl ether group, an epoxy group, an oxetane group and a mercapto group. It is preferable to have at least one functional group selected, particularly when it has an epoxy group, it is preferable because it has excellent adhesion between the obtained curable resin layer and the adherend, and when it has a vinyl ether group, it is a curable resin composition. It is preferable because it has excellent curability.

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

In addition to the above-exemplified compounds, the compounds represented by the general formula (3) include hydroxyethyl acrylamide and an ester of boric acid, methylol acrylamide and an ester of boric acid, hydroxyethyl acrylate and an ester of boric acid, and hydroxybutyl. Esters of (meth) acrylate and boric acid, such as esters of acrylate and boric acid, can be exemplified.

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

The bubble suppressant preferably has a reactive group in the compound. In this case, it is possible to reduce the generation of Lami bubbles when the polarizing element and the transparent protective film are bonded together. Examples of the reactive group of the bubble inhibitor include a polymerizable functional group, and specifically, a radically polymerizable functional group having an ethylenic double bond such as a (meth) acryloyl group, a vinyl group and an allyl group, and glycidyl. Examples thereof include an epoxy group such as a group, an oxetane group, a vinyl ether group, a cyclic ether group, a cyclic thioether group, and a cationically polymerizable functional group such as a lactone group. From the viewpoint of reactivity in the adhesive composition, a bubble inhibitor having a double bond as a reactive group is preferable, and a bubble inhibitor having a (meth) acrylic loyl group is more preferable.

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

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

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

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

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

General formula (4)

(However, L ⁺ represents an arbitrary onium cation. X ^- is PF _6- ^, SbF _6- ^, AsF _6- ^, SbCl _6- ^, BiCl _5- ^, SnCl _6- ^, ClO _4- ^, dithiocarbamate. Represents a counter anion selected from the group consisting of anion, SCN- ⁾ .

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

The counter anion X ⁻ in the general formula (4) is not particularly limited in principle, but a non-nucleophilic anion is preferable. When the counter anion X ^- is a non-nucleophilic anion, the nucleophilic reaction is unlikely to occur in the cation coexisting in the molecule or various materials used in combination, and as a result, the photoacid generator itself represented by the general formula (4) itself. And it is possible to improve the stability of the composition using it over time. The non-nucleophilic anion here refers to an anion having a low ability to cause a nucleophilic reaction. Examples of such anions include PF _6- ^, SbF _6- ^, AsF _6- ^, SbCl _6- ^, BiCl _5- ^, SnCl _6- ^, ClO _4- ^, dithiocarbamate anion, SCN ^-and the like.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Preferably, 3-methacryloxypropyltrimethoxysilane and 3-acryloxypropyltrimethoxysilane.

As a specific example of a silane coupling agent that is not active energy ray curable, a silane coupling agent having an amino group is preferable. Specific examples of the silane coupling agent having an amino group include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropylmethyldimethoxysilane, and γ-amino. Propylmethyldiethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane, γ- (2-Aminoethyl) Aminopropylmethyldiethoxysilane, γ- (2-aminoethyl) aminopropyltriisopropoxysilane, γ- (2- (2-aminoethyl) aminoethyl) aminopropyltrimethoxysilane, γ- (6-Aminohexyl) Aminopropyltrimethoxysilane, 3- (N-ethylamino) -2-methylpropyltrimethoxysilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, N-phenyl-γ -Aminopropyltrimethoxysilane, N-benzyl-γ-aminopropyltrimethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane , N-Phenylaminomethyltrimethoxysilane, (2-aminoethyl) aminomethyltrimethoxysilane, N, N'-bis [3- (trimethoxysilyl) propyl] ethylenediamine and other amino group-containing silanes; N-( Examples thereof include ketimine-type silanes such as 1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propaneamine.

As the silane coupling agent having an amino group, only one type may be used, or a plurality of types may be used in combination. Of these, in order to ensure good adhesion, γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane , Γ- (2-Aminoethyl) Aminopropyltriethoxysilane, γ- (2-Aminoethyl) Aminopropylmethyldiethoxysilane, N- (1,3-dimethylbutylidene) -3- (Triethoxysilyl)- 1-Propylamine is preferred.

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

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

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

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

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

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

The adhesive composition of the present invention can contain polyrotaxane. The polyrotaxane is a cyclic molecule, a linear molecule penetrating the opening of the cyclic molecule, and a seal placed at both ends of the linear molecule so that the cyclic molecule does not desorb from the linear molecule. Has a group and. The cyclic molecule preferably has an active energy ray-curable functional group.

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

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

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

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

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

A polarizing film using a resin composition containing polyrotaxane as an adhesive has excellent water resistance. The reason why the water resistance of the polarizing film is improved is not clear, but it is presumed as follows. That is, the cross-linking point can move due to the mobility of the cyclic molecule of polyrotaxane (so-called gliding effect), which imparts flexibility to the cured adhesive and increases the adhesion of the substituent to the surface irregularities. As a result, it is considered that the intrusion of water into the interface between the polarizing element and the adhesive layer was prevented. Furthermore, it is considered that the fact that polyrotaxane has a hydrophobic modifying group to impart hydrophobicity to the adhesive also contributed to the prevention of water intrusion into the interface between the polarizing element and the adhesive layer. The content of polyrotaxane is preferably 2% by mass to 50% by mass with respect to the resin composition.

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

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

<Easy-adhesive composition>
In order to further improve the adhesiveness between the polarizing element and the adjacent layer, in the present invention, the easy-adhesion composition may be applied to the bonding surface of the polarizing element (bonding surface with the adjacent layer). The easy-adhesive composition preferably contains the compound represented by the general formula (3). It is preferable to apply the easy-adhesion composition containing the boron-containing compound represented by the general formula (3) to the bonded surface of the polarizing element because the water resistance of the polarizing film is particularly improved. The reason why such an effect is exhibited is not clear, but the following reasons can be presumed.

In the easy-adhesion composition, the boron-containing compound represented by the above formula (3) can react with a functional group such as a hydroxyl group included in the substituent. This makes it possible to improve the adhesiveness between the polarizing element and, for example, the adhesive layer, and as a result, has the effect of improving the water resistance of the polarizing film. In the present invention, the easy-adhesive layer may be formed by applying the easy-adhesive composition to the entire surface on the adjacent layer side of the polarizing element, or by applying the easy-adhesive composition to at least a part of the surface. An easy-adhesion layer may be formed.

Among the compounds represented by the general formula (3), the compounds represented by the general formula (3') are preferable, and the compounds (3a) to (3d) are more preferable.

If the content of the compound represented by the general formula (3) is too small in the easy-adhesion composition, the proportion of the compound represented by the general formula (3) present on the surface of the easy-adhesion layer decreases, and the easy-adhesion effect is achieved. May be low. Therefore, the content of the compound represented by the general formula (3) in the easy-adhesion composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and 0. It is more preferably 1% by mass or more.

In addition to the compound described in the general formula (3) and the compound described in the general formula (3), in the present invention, a solvent may be contained in the easy-adhesion composition. As the solvent that may be contained in the easy-adhesion composition, a solvent capable of stabilizing the compound represented by the general formula (3) and dissolving or dispersing it is preferable. As such a solvent, an organic solvent, water, or a mixed solvent thereof can be used. Examples of the solvent include esters such as ethyl acetate, butyl acetate and 2-hydroxyethyl acetate; ketones such as methyl ethyl ketone, acetone, cyclohexanone, methyl isobutyl ketone, diethyl ketone, methyl-n-propyl ketone and acetyl acetone; tetrahydrofuran ( Cyclic ethers such as THF), dioxane; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; methanol, ethanol, n-propanol, isopropanol and cyclohexanol. Lipid or alicyclic alcohols such as; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether; glycol ether acetates such as diethylene glycol monomethyl ether acetate and diethylene glycol monoethyl ether acetate; etc. Is selected from.

Further, when the easy-adhesion composition is used in the present invention, it may contain other additives such as a tackifier, an ultraviolet absorber, an antioxidant, a stabilizer such as a heat-resistant stabilizer, and the like.

<Resin film>
The polarizing film according to the present invention may include a resin film laminated on the surface of the iodine-based polarizing element on the adjacent layer side. In the conventional polarizing film in which a resin film having a moisture permeability of 80 g / ( ^m 2.24 h) or more is laminated on an iodine-based polarizing element via an adhesive layer, iodine is added to the resin film from the iodine-based polarizing element. Moisture reliability tends to deteriorate as a result of omission, but the polarizing film according to the present invention improves humidification reliability. Examples of the resin film having a moisture permeability of 80 g / ( ^m 2.24 h) or more in the present invention include a specific transparent protective film or a retardation film.

Examples of the transparent protective film having a moisture permeability of 80 g / ( ^m 2.24 h) or more include a TAC film (moisture permeability 1250 g / ( ^m 2.24 h)) and a TAC film with a hard coat (moisture permeability 420 g / ( ^m 2.24 h)). 24h)), polycarbonate film (moisture permeability 90g / (m ^2.24h )) and the like can be mentioned.

Examples of the retardation film having a moisture permeability of 80 g / (m ^2.24h ) or more include a polycarbonate resin-based retardation film (moisture permeability 90 g / (m ^2.24h )) and a retardation film containing a liquid crystal solidifying layer (transparency). Humidity 500 g / ( ^m 2.24 h)), and the like.

Hereinafter, an example of a method for manufacturing a polarizing film according to the present invention will be described.

The polarizing film according to the present invention can be manufactured, for example, by the following manufacturing method.
A method for producing a polarizing film including an iodine-based polarizing element and an adjacent layer on at least one surface of the iodine-based polarizing element, wherein the adjacent layer is in direct contact with the iodine-based polarizing element, and the adhesive. A barrier layer is provided on the layer, the HSP value distance between the adjacent layer and water is 26 or more, and an adhesive composition as a raw material for the adhesive layer is provided on at least one surface of the iodine-based polarizing element. The coating process for coating, the barrier layer surface of the barrier layer with a separator film, which is a laminate of the resin layer to be the barrier layer and the separator, and the coated surface of the adhesive composition of the iodine-based polarizing element are bonded together. A method for producing a polarizing film, which comprises a bonding process and a forming process of peeling off the separator of the barrier layer with a separator film to form a polarizing element with a barrier layer.

In addition, in the polarizing film according to the present invention, in order to further improve the adhesiveness between the polarizing element and the adjacent layer, in the present invention, the easy-adhesion composition is applied to the bonding surface of the polarizing element (bonding surface with the adjacent layer). You may paint things. In this case, before the coating step of applying the adhesive composition which is the raw material of the adhesive layer to at least one surface of the iodine-based polarizing element (this is referred to as "adhesive composition coating step"), An easy-adhesive composition coating step may be provided in which the easy-adhesive composition is applied to the bonded surface of the polarizing element (bonded surface with the adjacent layer).

<Coating process>
The method for applying the adhesive composition, the easy-adhesive composition, and the adhesive composition to the bonded surface of the polarizing element is appropriately selected depending on the viscosity of the composition and the desired thickness, but is an iodine-based polarizing element. From the viewpoint of removing foreign matter on the surface and coatability, it is preferable to use the post-weighing coating method. Specific examples of the post-weighing coating method include a gravure roll coating method, a forward roll coating method, an air knife coating method, and a rod / bar coating method. Among these, the gravure roll coating method is particularly preferable from the viewpoint of removing foreign substances on the surface of the transparent protective film and coating property.

Before the coating step, the easy-adhesive composition may be applied to the coated surface of the binder composition of the polarizing element. As a method of applying the easy-adhesion composition to the bonded surface of the polarizing element, it is preferable to use a post-measurement coating method because it has the same effect as the above-mentioned coating process.

In the gravure roll coating method, various patterns can be formed on the surface of the gravure roll, for example, a honeycomb mesh pattern, a trapezoidal pattern, a lattice pattern, a pyramid pattern, a diagonal line pattern, or the like can be formed. In order to effectively prevent the occurrence of appearance defects of the finally obtained polarizing film, it is preferable that the pattern formed on the surface of the gravure roll is a honeycomb mesh pattern. In the case of the honeycomb mesh pattern, the cell volume is preferably 1 to 5 cm ³ / m ² and 2 to 3 cm ³ / m ² in order to improve the surface accuracy of the coated surface after the easy-adhesive composition is applied. Is preferable. Similarly, in order to improve the surface accuracy of the coated surface after coating the easy-adhesive composition, the number of cell lines per roll 1 inch is preferably 200 to 3000 lines / inch. Further, it is preferable that the rotation speed ratio of the gravure roll to the traveling speed of the polarizing element is 100 to 300%.

<Lasting process>
The polarizing element and the resin film for forming the barrier layer are bonded to each other via the adhesive composition coated as described above. The polarizing element and the resin film for forming the barrier layer can be bonded by a roll laminator or the like.

<Formation process>
The barrier layer with a separator is preferably molded by cast molding or extrusion molding. In cast molding, a barrier layer with a separator can be obtained by applying a solution in which a resin to be a barrier layer is dissolved in an arbitrary solvent to a separator and drying the solvent. In extrusion molding, a barrier layer with a separator can be obtained by coextrusion of a resin to be a barrier layer and a resin to be a separator.

When forming a barrier layer by cast molding, a barrier having an arbitrary thickness is obtained by appropriately adjusting the wire thickness called the bar coater count or wire when applying the solution, and further, by appropriately adjusting the solid content concentration of the solution to be applied. Layers can be formed.

A second coating step of producing a laminate of a polarizing element and a barrier layer via an adhesive layer, and then applying an adhesive composition to the barrier layer as needed, followed by the adhesive composition. In the second bonding step of bonding a resin film such as a transparent protective film or a retardation film to the coated surface, an active energy ray is irradiated, and an adjacent layer is interposed via an adhesive layer which is a cured product of the adhesive composition. An adhesive step of adhering the iodine-based polarizing element and the resin film may be carried out.

<Adhesion process>
After the polarizing element and the transparent protective film are bonded together, they are irradiated with active energy rays (electron beam, ultraviolet rays, visible light, etc.) to cure and bond the adhesive composition, or the adhesive composition and the easy-adhesive composition. Form a layer of agent. The irradiation direction of the active energy ray (electron beam, ultraviolet ray, visible light, etc.) can be any appropriate direction. It is preferable to irradiate from the transparent protective film side. When irradiated from the splitter side, the substituent may be deteriorated by active energy rays (electron beam, ultraviolet rays, visible light, etc.).

As the irradiation conditions when irradiating the electron beam, any appropriate conditions can be adopted as long as the above-mentioned adhesive composition can be cured. For example, in electron beam irradiation, the acceleration voltage is preferably 5 kV to 300 kV, and more preferably 10 kV to 250 kV. If the acceleration voltage is less than 5 kV, the electron beam may not reach the adhesive and the curing may be insufficient. If the acceleration voltage exceeds 300 kV, the penetrating power through the sample is too strong and damages the transparent protective film and the polarizing element. May be given. The irradiation dose is 5 to 100 kGy, more preferably 10 to 75 kGy. When the irradiation dose is less than 5 kGy, the adhesive is insufficiently cured, and when it exceeds 100 kGy, the transparent protective film and the polarizing element are damaged, the mechanical strength is lowered and yellowing occurs, and the predetermined optical characteristics are obtained. I can't.

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

In the method for producing a polarizing film, it is preferable to use an active energy ray containing 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. .. When ultraviolet rays and visible light are used, and when a transparent protective film having an ultraviolet absorbing ability (ultraviolet opaque transparent protective film) is used, it is shorter than 380 nm because it absorbs light having a wavelength shorter than about 380 nm. Light of wavelength does not reach the adhesive composition and does not contribute to its polymerization reaction. Further, the light having a wavelength shorter than 380 nm absorbed by the transparent protective film is converted into heat, and the transparent protective film itself generates heat, which causes defects such as curl and wrinkles of the polarizing film. Therefore, when ultraviolet rays and visible rays are adopted in the present invention, it is preferable to use a device that does not emit light having a wavelength shorter than 380 nm as an active energy ray generator, and more specifically, integration in a wavelength range of 380 to 440 nm. The ratio of the illuminance to the integrated illuminance in the wavelength range of 250 to 370 nm is preferably 100: 0 to 100: 50, and more preferably 100: 0 to 100: 40. In the method for producing a polarizing film according to the present invention, gallium-filled metal halide lamps and LED light sources that emit light in a wavelength range of 380 to 440 nm are preferable as the active energy rays. Alternatively, with ultraviolet rays such as low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, incandescent lamp, xenon lamp, halogen lamp, carbon arc lamp, metal halide lamp, fluorescent lamp, tungsten lamp, gallium lamp, excima laser or sunlight. A light source containing visible light can be used, and a bandpass filter can be used to block ultraviolet rays having a wavelength shorter than 380 nm. In order to prevent curling of the polarizing film while improving the adhesive performance of the adhesive layer between the polarizing element and the transparent protective film, a gallium-filled metal halide lamp can be used and light having a wavelength shorter than 380 nm can be blocked. It is preferable to use an active energy ray obtained through a bandpass filter or an active energy ray having a wavelength of 405 nm obtained by using an LED light source.

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

<Optical film>
The polarizing film produced by the production method according to the present invention can be used as an optical film laminated with another optical layer in practical use. The optical layer is not particularly limited, but for example, a liquid crystal such as a retardation film (including a wave plate such as 1/2 or 1/4), a visual compensation film, a luminance improving film, a reflecting plate or an antitransmissive plate, etc. Examples thereof include an optical layer that may be used for forming a display device or the like.

As the retardation film, a 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 phase difference is usually controlled in the range of 40 to 200 nm, and the thickness direction phase difference is usually controlled in the range of 80 to 300 nm.

Examples of the retardation film include a birefringent film obtained by uniaxially or biaxially stretching a polymer material, an alignment film of a liquid crystal polymer, and a film in which an alignment layer of a liquid crystal polymer is supported by a film. The thickness of the retardation film is not particularly limited, but is generally about 20 to 150 μm.

The retardation film has the following equations (1) to (3):
0.70 <Re [450] / Re [550] <0.97 ... (1)
1.5 × 10 ^-3 <Δn <6 × 10 ^-3 ... (2)
1.13 <NZ <1.50 ... (3)
(In the equation, Re [450] and Re [550] are in-plane retardation values of the retardation film measured with light having a wavelength of 450 nm and 550 nm at 23 ° C., respectively, and Δn is the slow phase of the retardation film. In-plane double refraction, which is nx-ny when the refractive indexes in the axial direction and the phase-advancing axis direction are nx and ny, respectively, and NZ is when nz is the refractive index in the thickness direction of the retardation film. A reverse wavelength dispersion type retardation film satisfying (the ratio of nx-nz which is double refraction in the thickness direction to nx-ny which is in-plane double refraction) may be used.

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

The adhesive layer can also be provided on one or both sides of a polarizing film or an optical film as a superimposing layer of a different composition or type. Further, when provided on both sides, adhesive layers having different compositions, types and thicknesses can be formed on the front and back sides of the polarizing film or the optical film. The thickness of the adhesive layer can be appropriately determined depending on the purpose of use, adhesive strength, etc., and is generally 1 to 500 μm, preferably 1 to 200 μm, and particularly preferably 1 to 100 μm.

The exposed surface of the adhesive layer is temporarily covered with a separator for the purpose of preventing contamination until it is put into practical use. This makes it possible to prevent the adhesive layer from coming into contact with the adhesive layer under normal handling conditions. Except for the above thickness conditions, the separator may be a suitable thin leaf such as a plastic film, rubber sheet, paper, cloth, non-woven fabric, net, foam sheet or metal leaf, or a laminate thereof, and if necessary, a silicone-based or long material. Appropriate conventional ones such as those coated with an appropriate release agent such as chain alkyl type, fluorine type and molybdenum sulfide can be used.

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

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

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

<Thin splitter>
First, a stretched laminate in which a 9 μm-thick PVA layer was formed on an amorphous PET substrate was subjected to aerial auxiliary stretching at a stretching temperature of 130 ° C. to form a stretched laminate, and then the stretched laminate was dyed to form a colored laminate. And further contains a 5 μm thick PVA layer in which the colored laminate was stretched integrally with the amorphous PET substrate so that the total stretch ratio was 5.94 times by stretching in boric acid at a stretching temperature of 65 ° C. An optical film laminate was produced. The PVA molecules in the PVA layer formed on the amorphous PET substrate by such two-step stretching are highly oriented, and the iodine adsorbed by dyeing is unidirectionally oriented as a polyiodide ion complex. An optical film laminate containing a 5 μm-thick PVA layer (thin polarizing element) constituting the iodine-based thin polarizing element was obtained.

<Transparent protective film>
The following films were used as the transparent protective film.
"TAC"; triacetyl cellulose (TAC) film (moisture permeability 420 g / ( ^m 2.24 h), HSP value distance from water 22.2, thickness 25 μm) (trade name "Konica Minolta Tack Film KC2UA", (Konica Minolta) ) "PC"; Polycarbonate (PC) film (moisture permeability 90 g / ( ^m 2.24 h), HSP value distance from water 22.2, thickness 13 μm)
"COP"; cycloolefin polymer (COP) film (moisture permeability 8 g / ( ^m 2.24 h), HSP value distance from water 33.3, thickness 20 μm) (trade name "Zeonoa film ZF14", manufactured by Zeon Corporation

<Phase difference film>
The retardation film was manufactured by the following manufacturing method.

Polymerization of polyester carbonate-based resin Polymerization was carried out using a batch polymerization apparatus consisting of two vertical reactors equipped with a stirring blade and a reflux condenser controlled at 100 ° C. Bis [9- (2-phenoxycarbonylethyl) fluoren-9-yl] 29.60 parts by mass (0.046 mol) of methane, 29.21 parts by mass (0.200 mol) of isosorbide (ISB), 42 of spiroglycol (SPG) .28 parts by mass (0.139 mol), 63.77 parts by mass (0.298 mol) of diphenyl carbonate (DPC) and calcium acetate monohydrate 1.19 x 10 ^-2 parts by mass (6.78 x 10- ⁾ as a catalyst. ⁵ mol) was charged. After substituting nitrogen under reduced pressure in the reactor, heating was performed with a heat medium, and stirring was started when the internal temperature reached 100 ° C. The internal temperature was brought to 220 ° C. 40 minutes after the start of the temperature rise, and the depressurization was started at the same time as controlling to maintain this temperature, and the temperature was 13.3 kPa 90 minutes after reaching 220 ° C. The phenol vapor produced by the polymerization reaction was guided to a reflux condenser at 100 ° C., the monomer component contained in a small amount in the phenol vapor was returned to the reactor, and the non-condensed phenol vapor was guided to a condenser at 45 ° C. for recovery. Nitrogen was introduced into the first reactor and the pressure was once restored to atmospheric pressure, and then the oligomerized reaction solution in the first reactor was transferred to the second reactor. Then, the temperature rise and depressurization in the second reactor were started, and the internal temperature was 240 ° C. and the pressure was 0.2 kPa in 50 minutes. Then, the polymerization was allowed to proceed until the stirring power became a predetermined value. When the predetermined power was reached, nitrogen was introduced into the reactor to repressurize, the produced polyester carbonate-based resin was extruded into water, and the strands were cut to obtain pellets.

Preparation of Phase Difference Film After vacuum-drying the obtained polyester carbonate resin (pellet) at 80 ° C for 5 hours, a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder set temperature: 250 ° C), T-die (width 200 mm) , Set temperature: 250 ° C.), chill roll (set temperature: 120 to 130 ° C.), and a film-forming device equipped with a winder was used to prepare a long resin film having a thickness of 130 μm. The obtained long resin film was stretched while adjusting so that a predetermined retardation was obtained, to obtain a retardation film having a thickness of 48 μm. The stretching conditions were a stretching temperature of 143 ° C. and a stretching ratio of 2.8 times in the width direction. The Re (550) of the obtained retardation film was 141 nm, the Re (450) / Re (550) was 0.86, and the Nz coefficient was 1.12.
The HSP value distance of the retardation film from water was 22.7, and the moisture permeability was 90 g / (m2.24h).

<Active energy ray>
Visible light (gallium-filled metal halide lamp) as an active energy ray Irradiator: Fusion UV Systems, Inc. Light HAMMER10 bulb: V bulb Peak illuminance: 1600 mW / cm ² , integrated irradiation dose 1000 / mJ / cm ² (wavelength 380 ~) 440 nm) was used. The illuminance of visible light was measured using a Solar-Check system manufactured by Solarll.

<Adhesive layers 1 to 3>
The adhesive layers 1 to 3 were formed from the following adhesive compositions 1 to 3 as raw materials.
"Adhesive composition 1"; an adhesive composition containing 30 parts by weight of ACMO, 30 parts by weight of 19NDA, and 15 parts by weight of P2HA (with water of the adhesive layer 1 obtained after curing the adhesive composition 1). HSP value distance; 27.0)
"Adhesive Composition 2"; An adhesive composition containing 36 parts by weight of 19NDA, 12.5 parts by weight of HEAA, 22 parts by weight of M5700, 6 parts by weight of DEAA, and 12.5 parts by weight of HPPA (adhesive). HSP value distance of the adhesive layer 2 obtained after curing the composition 2 with water; 25.7)
"Adhesive Composition 3"; Adhesive composition containing 10 parts by weight of 19NDA, 43.5 parts by weight of P2HA, 10 parts by weight of HEAA, 10 parts by weight of M5700, 10 parts by weight of M220, and 3 parts by weight of DEAA. Material (HSP value distance of the adhesive layer 3 obtained after curing the adhesive composition 3 with water; 25.5)

In each of the above adhesive compositions,
"ACMO"; acryloylmorpholine (trade name "ACMO", manufactured by KJ Chemicals)
"19NDA"; 1,9-nonanediol diacrylate (trade name "Light Acrylate 1,9ND-A", manufactured by Kyoeisha Chemical Co., Ltd.)
"P2HA"; phenoxydiethylene glycol acrylate (trade name "light acrylate P2HA", manufactured by Kyoeisha Chemical Co., Ltd.)
"HEAA"; N- (2-hydroxyethyl) acrylamide (trade name "HEAA", manufactured by KJ Chemicals)
"M5700"; reaction product of 2,3-epoxypropyl = phenyl ether containing 2-hydroxy-3-phenoxypropyl acrylate as a main component and acrylic acid.
(Product name "Aronix M-5700", manufactured by Toagosei Co., Ltd.)
"M220"; (Tripropylene glycol diacrylate) (trade name "Aronix M-220", manufactured by (Toagosei))
"DEAA"; (NN-diethylacrylamide) (trade name "DEAA", manufactured by (KJ Chemicals))
"HPPA"; (reactant with neopentyl glycol, hydroxypivalic acid, acrylic acid) (trade name "light acrylate HPP-A", manufactured by Kyoeisha Chemical Co., Ltd.)

Example 1
To 90 g of a 2: 3 mixed solvent of 2,4-trichlorobenzene and toluene, 10 g of a cycloolefin polymer (COP) film (trade name "Zeonoa film ZF14") was added to prepare a COP solution. Next, a COP solution prepared on a PET film (separator) is applied using a bar coater # 5, and then dried in an oven at 60 ° C. for 3 minutes to form a 1 μm-thick COP film (barrier) on the separator. A barrier layer with a separator film was produced in which layers) were laminated. The moisture permeability of the barrier layer was 480 g / ( ^m 2.24 h), and the HSP value distance from water was 33.3.

MCD coater (manufactured by Fuji Kikai Co., Ltd.) on the side surface (bonded surface) of the thin polarizing element of the optical film laminate in which the thin polarizing element and the amorphous PET substrate are laminated (cell shape: honeycomb, number of gravure rolls: The adhesive composition 2 was applied using 1000 lines / inch, rotation speed 140% / line speed), and bonded to the barrier layer surface (bonding surface) of the barrier layer with a separator film by a roll machine (bonding). The line speed is 25m / min). Then, the adhesive composition 2 was cured by irradiating the visible light from the separator film side of the barrier layer with the separator film with an active energy ray irradiating device. Then, by peeling the separator film from the barrier layer with the separator film, the thin polarizing element (an optical film laminate in which the thin polarizing element and the amorphous PET base material are laminated) and the barrier layer 1 are attached to the adhesive layer 2. A laminated film 1 laminated via the above was obtained. The thickness of the barrier layer 1 in the laminated film 1 was 1 μm, and the thickness of the adhesive layer 2 was 1 μm. The barrier layer 1 and the adhesive layer 2 form an adjacent layer 1, and the HSP value distance between the adjacent layer 1 and water was 29.4.

Adhesive composition 1 is applied to one barrier layer of the laminated film 1 by MCD coater (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, number of gravure rolls: 1000 lines / inch, rotation speed 140% / line speed). The film was coated to a thickness of 0.7 μm and bonded to the protective film 1 (“TAC”) with a roll machine (bonding line speed is 25 m / min). Then, the protective film 1 is irradiated from the protective film 1 side with an active energy ray irradiation device to cure the adhesive composition 1, so that the protective film 1 is laminated on the barrier layer 1 via the adhesive layer 1. I got 2. The thickness of the adhesive layer 1 was 0.9 μm.

The amorphous PET base material of the obtained laminated film 2 (amorphous PET base material included in an optical film laminate in which a thin polarizing element and an amorphous PET base material are laminated) is peeled off to obtain a thin polarizing element. Exposed. Next, the adhesive composition 2 was applied to the thin polarizing element surface side by the same method as described above, and bonded to the barrier layer surface (bonding surface) of the barrier layer with a separator film by a roll machine (bonding line). The speed is 25 m / min). Then, the adhesive composition 2 was cured by irradiating the visible light from the separator film side of the barrier layer with the separator film with an active energy ray irradiating device. Then, by peeling the separator film from the barrier layer with the separator film, a laminated film 3 in which the barrier layer 2 was laminated on the other surface of the thin polarizing element via the adhesive layer 2 was obtained. The thickness of the barrier layer 2 in the laminated film 3 was 1 μm, and the thickness of the adhesive layer 2 was 1 μm. The barrier layer 2 and the adhesive layer 2 form an adjacent layer 2, and the HSP value distance between the adjacent layer 2 and water was 29.4.

The adhesive composition 3 was applied to the two barrier layers of the laminated film 3 by the same method as described above, and bonded to the panel-side protective film (phase difference film) with a roll machine (bonding line speed is 25 m /). min). Then, by irradiating the adhesive composition 3 from the panel side protective film side with an active energy ray irradiating device to cure the adhesive composition 3, the polarizing film according to Example 1 (in order from the visual recognition side, "protective film 1"-"adhesive" Agent layer 1 "-" Barrier layer 1 "-" Adhesive layer 2 "-" Thin polarizing element "-" Adhesive layer 2 "-" Barrier layer 2 "-" Adhesive layer 3 "-" Panel side protective film " (Laminated polarizing film) was manufactured.

In addition, "protective film 1", "adhesive layer 1", "barrier layer 1", "adhesive layer 2", "thin polarizing element", "adhesive layer 2", "barrier layer 2" in Example 1 , The order of laminating the "adhesive layer 3" and the "panel-side protective film" is not limited to the order described above, and can be arbitrarily changed.

Examples 2 to 5, Comparative Examples 1 to 3
Examples except that the presence / absence of the barrier layer 1 and the adhesive layer 1 (or the barrier layer 2 and the adhesive layer 3), the type of the protective film 1, and the thickness of each adhesive layer are changed to those shown in Table 1. A polarizing film was produced by the same method as in 1.

(Transmittance change test)
The transmittance Ts of the obtained polarizing film was measured using an ultraviolet-visible spectrophotometer (V-7100 manufactured by JASCO Corporation), and the single transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc were measured for each of the polarizing films. Ts, Tp and Tc. These Ts, Tp and Tc are Y values measured by the JIS Z8701 two-degree visual field (C light source) and corrected for luminosity factor. The refractive index of the protective layer was 1.50, and the refractive index of the surface of the polarizing film opposite to the protective layer was 1.53. It is a Y value measured by a 2 degree field of view (C light source) of Z8701 and corrected for luminosity factor. The refractive index of the protective layer was 1.50, and the refractive index of the surface of the polarizing film opposite to the protective layer was 1.53. The single transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc measured using an ultraviolet-visible spectrophotometer (V-7100 manufactured by JASCO Corporation) were defined as Ts, Tp, and Tc of the polarizing film, respectively. These Ts, Tp and Tc are Y values measured by the JIS Z8701 two-degree visual field (C light source) and corrected for luminosity factor. The refractive index of the protective layer was 1.50, and the refractive index of the surface of the polarizing film opposite to the protective layer was 1.53. After exposure to 60 ° C. and 95% RH for 240 hours, the transmittance Ts of the polarizing film after charging was measured by the same method, and the transmittance change ΔT (%) = | (transmittance Ts (%) before charging. ))-(Transmittance Ts (%) after charging) | was determined. The results are shown in Table 1.

(Judgment of humidification reliability)
The judgment of humidification reliability is ⊚ when the transmittance change ΔT (%) obtained above is 0.4 or less, and 〇 and 0.8 when it is more than 0.4 and 0.8 or less. When it was 1.0 or less, it was evaluated as Δ, and when it exceeded 1.0, it was evaluated as ×. The results are shown in Table 1.

Claims

An iodine-based polarizing element and an adjacent layer on at least one surface of the iodine-based polarizing element are provided.
A polarizing film characterized in that the HSP value distance between the adjacent layer and water is 26 or more.
The polarizing film according to claim 1, wherein the adjacent layer includes a barrier layer having a moisture permeability of 500 g / ( m 2.24 h) or less.
The polarizing film according to claim 2, wherein the barrier layer has a thickness of 1 μm or more.
The polarizing film according to claim 2 or 3, wherein the adjacent layer includes the barrier layer via an adhesive layer that is in direct contact with the iodine-based polarizing element.
The polarizing film according to claim 2 or 3, wherein the adjacent layer includes the barrier layer via an adhesive layer formed on an easily adhesive layer that is in direct contact with the iodine-based polarizing element.
The polarizing film according to claim 4 or 5, wherein the ratio (Tb / Ta) of the thickness Tb of the barrier layer to the thickness Ta of the adhesive layer is 0.05 to 50.
The polarizing film according to any one of claims 1 to 6, further comprising a resin film laminated on the surface of the iodine-based polarizing element on the side of the adjacent layer.
The polarizing film according to claim 7, wherein the resin film has a moisture permeability of 80 g / ( m 2.24 h) or more.
An optical film characterized in that at least one polarizing film according to any one of claims 1 to 8 is laminated.
An image display device comprising the polarizing film according to any one of claims 1 to 8 or the optical film according to claim 9.