WO2019163749A1

WO2019163749A1 - Polarizing film, method for manufacturing same, optical film, and image display device

Info

Publication number: WO2019163749A1
Application number: PCT/JP2019/006038
Authority: WO
Inventors: 菅野　亮; 昌之岡本; 紀二大學; 山崎　達也
Original assignee: 日東電工株式会社
Priority date: 2018-02-26
Filing date: 2019-02-19
Publication date: 2019-08-29

Abstract

Provided are: a polarizing film; and a method for manufacturing the same, the polarizing film being capable of suppressing the deterioration of the optical properties of a polarizer in a humidified environment, as well as exhibiting excellent crack durability, which is especially required for an irregular polarizing film subjected to, for example, small-diameter concave R-processing or small-hole processing. The polarizing film has a cellulose-based resin film as a transparent protective film on at least one surface of a polarizer, an adhesive layer being provided between the resin film and the polarizer. The adhesive layer is formed by a cured layer obtained by irradiating an active energy ray-curable adhesive composition with active energy rays, the active energy ray-curable adhesive composition containing predetermined amounts of active energy ray-curable compounds (A), (B), and (C) having SP values of 29.0-32.0 (MJ/m³)^1/2, at least 18.0 (MJ/m³)^1/2 and less than 21.0 (MJ/m³)^1/2, and 21.0-26.0 (MJ/m³)^1/2, respectively, on the basis of 100 wt% of the total amount of the composition.

Description

Polarizing film and manufacturing method thereof, optical film, and image display device

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

In various image display devices, a polarizing film is used for image display. For example, in a liquid crystal display device (LCD), it is indispensable to dispose polarizing films on both sides of a glass substrate on which a liquid crystal panel surface is formed because of its image forming method. Further, in the organic EL display device, a circularly polarizing film in which a polarizing film and a quarter wavelength plate are laminated is disposed on the viewing side of the organic light emitting layer in order to shield the specular reflection of external light on the metal electrode.

As the polarizing film, generally, a polyvinyl alcohol adhesive, an active energy ray curable adhesive, or the like is provided on one or both sides of a polarizer made of a dichroic material such as a polyvinyl alcohol film and iodine. The thing stuck together by is used.

In a severe environment of thermal shock (for example, a heat shock test in which a temperature condition of −40 ° C. and 85 ° C. is repeated), the polarizing film spreads along the absorption axis direction of the polarizer due to a change in the contraction stress of the polarizer. There is a problem that cracks (through cracks) are likely to occur. Therefore, in order to suppress the shrinkage of the polarizer and reduce the influence of thermal shock, if the thin polarizer has a thickness of 10 μm or less, the change in the shrinkage stress is small, so that the through crack is less likely to occur. For example, a polarizing film in which a protective film is bonded to one side or both sides of a thin polarizer having a thickness of 10 μm or less and generation of through cracks is suppressed is disclosed (for example, see Patent Document 1 below).

On the other hand, a thin polarizer having a thickness of 10 μm or less has a problem that the optical characteristics in a humidified environment are likely to deteriorate. Therefore, in the following Patent Document 2, a resin film having extremely low moisture permeability is used as a protective film for the thin polarizer, and the deterioration of the polarizer due to humidification of the thin polarizer is suppressed.

In recent years, polarizing plates have also been used in automobile meter displays, smart watches, etc., and due to their design, etc., the polarizing plate can be used in a shape other than rectangular, or a through hole can be formed in the polarizing plate. It has also been desired (see, for example, Patent Document 3 below). In the profile processing such as these, there is an increasing demand for more delicate and precise processing and more complicated processing that have not been seen in the past, such as small-diameter concave R processing and small-diameter holes. It has been found that there is a tendency that cracks are likely to occur in recessed portions such as small-diameter hole processing and small-diameter concave R processing as compared with the case of a short shape.

Japanese Patent Laying-Open No. 2015-152911 JP 2017-2111433 A JP2018-12182A

The technology described in Patent Document 2 uses a polarizing film that uses a resin film with extremely low moisture permeability as a protective film for the thin polarizer, and suppresses the deterioration of the thin polarizer in a humidified environment and the occurrence of cracks during thermal shock. Are trying. However, while evaluating the presence or absence of cracks in the processed part at the time of thermal shock in a deformed polarizing film subjected to recent small-diameter concave R processing and small-diameter hole processing, durability that can clear the more severe crack test is being sought. is there. Therefore, the actual situation is that the polarizing films reported up to now have room for further improvement in terms of durability against cracks.

The present invention has been developed in view of the above circumstances, and is particularly required for a deformed polarizing film subjected to suppression of deterioration of optical characteristics under a humidified environment, for example, small-diameter concave R processing or small-diameter hole processing. An object of the present invention is to provide a polarizing film capable of achieving both crack durability and a method for producing the same.

Furthermore, an object is to provide an optical film in which at least one polarizing film is laminated, and further an image display device using the polarizing film and / or the optical film.

The above problem can be solved by the following configuration. That is, the present invention is a polarizing film in which a transparent protective film is provided on at least one surface of a polarizer via an adhesive layer, and the transparent protective film is a cellulose resin film, and the adhesive The layer is formed by a cured product layer formed by irradiating an active energy ray-curable adhesive composition with active energy rays, and the active energy ray-curable adhesive composition has a total weight of 100% by weight. %, The active energy ray-curable compound (A) having an SP value of 29.0 (MJ / m ³ ) ^1/2 or more and 32.0 (MJ / m ³ ) ^1/2 or less is 0.0 to The active energy ray-curable compound (B) having 4.0% by weight and an SP value of 18.0 (MJ / m ³ ) ^1/2 or more and less than 21.0 (MJ / m ³ ) ^1/2 is 5.0. ~ 98.0 wt%, and SP value is 21 Is 0 ^(MJ / ^{m 3) 1/2} or more 26.0 ^(MJ / ^{m 3) 1/2} which is an active energy ray-curable compound (C) 5.0 ~ 98.0 wt% content is less The present invention relates to a polarizing film.

In the polarizing film, the thickness of the polarizer is preferably 3 μm or more and 15 μm or less.

In the polarizing film, the active energy ray-curable adhesive composition preferably contains 20 to 80% by weight of the active energy ray-curable compound (B) when the total amount of the composition is 100% by weight.

In the polarizing film, it is preferable that the active energy ray-curable adhesive composition contains an acrylic oligomer (D) obtained by polymerizing a (meth) acrylic monomer.

The said polarizing film _WHEREIN: It is preferable that the acrylic equivalent _{Cae of the} said active energy ray hardening-type adhesive composition represented by following formula (1) is 140 or more. C _ae = 1 / Σ (W _N / N _ae ) (1),
In the formula (1), W _N is a mass fraction of the active energy ray-curable compound _N in the composition, and N _ae is an acrylic equivalent of the active energy ray-curable compound N.

In the polarizing film, it is preferable that the active energy ray-curable adhesive composition contains a radical polymerization initiator having a hydrogen abstracting action.

In the polarizing film, the radical polymerization initiator is preferably a thioxanthone radical polymerization initiator.

In the polarizing film, the active energy ray-curable adhesive composition contains an acrylic oligomer (D),
Between the transparent protective film and the adhesive layer, a compatible layer in which these compositions continuously change is formed,
When the thickness of the compatible layer is P (μm) and the content of the acrylic oligomer (D) when the total amount of the composition is 100% by weight is Q% by weight, the value of P × Q is 10 Is preferably small.

In the polarizing film, at least one bonding surface of the polarizer and the transparent protective film has the following general formula (1):

(Wherein X is a functional group containing a reactive group, and R ¹ and R ² are each independently a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, or an aryl group. Or represents a heterocyclic group),
It is preferable that the compound represented by the general formula (1) is interposed between one or both of the polarizer and the adhesive layer and the transparent protective film and the adhesive layer.

In the polarizing film, the compound represented by the general formula (1) is represented by the following general formula (1 ′).

It is preferable that Y is an organic group (wherein X, R ¹ and R ² are the same as described above).

In the polarizing film, it is preferable that the bonding surface of the polarizer includes a compound represented by the general formula (1).

In the polarizing film, the reactive group possessed by the compound represented by the general formula (1) is an α, β-unsaturated carbonyl group, a vinyl group, a vinyl ether group, an epoxy group, an oxetane group, an amino group, an aldehyde group, It is preferably at least one reactive group selected from the group consisting of mercapto groups and halogen groups.

Further, the present invention provides a bonding process in which an active energy ray-curable adhesive composition is applied to at least one surface of a polarizer and a transparent protective film, and the polarizer and the transparent protective film are bonded together. Through the adhesive layer obtained by irradiating an active energy ray from the polarizer surface side or the transparent protective film surface side and curing the active energy ray-curable adhesive composition, The transparent protective film is a cellulose-based resin film, and the active energy ray-curable adhesive composition is 100% by weight of the total composition. when, SP value 29.0 ^(MJ / ^{m 3) 1/2} or more 32.0 ^(MJ / ^{m 3)} the active energy ray-curable compound is less than ^half the (a) 1.0 to 4.0 wt%, SP value of 18.0 ^(MJ / ^{m 3) 1/2} or more 21.0 ^(MJ / ^{m 3)} The active energy ray-curable compound is less than ^1/2 the (B) An active energy ray-curable compound having a SP value of 5.0 to 98.0% by weight and an SP value of 21.0 (MJ / m ³ ) ^1/2 or more and 26.0 (MJ / m ³ ) ^1/2 or less (C ) In an amount of 5.0 to 98.0% by weight.

In the manufacturing method of the said polarizing film, the following general formula (1): on the bonding surface of at least one of the said polarizer and the said transparent protective film:

(Wherein X is a functional group containing a reactive group, and R ¹ and R ² are each independently a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, or an aryl group. Or an easy adhesion treatment step of attaching a heterocyclic group.

In the manufacturing method of the said polarizing film, the compound represented by the said General formula (1) is the following general formula (1 ').

In the method for producing a polarizing film, prior to the coating step, at least one surface of the polarizer and the transparent protective film, and a surface to be bonded is subjected to corona treatment, plasma treatment, excimer treatment, or frame treatment. It is preferable to carry out.

In the method for producing a polarizing film, the active energy ray preferably contains visible light having a wavelength range of 380 to 450 nm.

In the method for producing a polarizing film, the active energy ray preferably has a ratio of an integrated illuminance in a wavelength range of 380 to 440 nm to an integrated illuminance in a wavelength range of 250 to 370 nm of 100: 0 to 100: 50.

Furthermore, in the present invention, at least one polarizing film according to any one of the above is laminated, the polarizing film according to any one of the above, and / or the above optical film. The present invention relates to an image display device.

Not only irregular polarizing films with small-diameter concave R processing and small-diameter hole processing, but also normal polarizing films with a short shape, due to various factors, it is possible to suppress the deterioration of optical characteristics in a humidified environment. As described above, it is difficult to achieve both excellent crack durability. As a result of intensive studies by the present inventors to achieve both of these, first, it is possible to form an adhesive layer that improves the adhesiveness between the polarizer and the transparent protective film and improves the optical durability. (I) Active energy After developing a wire curable adhesive composition, it has been found that the optimal (ii) transparent protective film is selected and combined with (i) to achieve both of the above problems.

First, (i) the active energy ray-curable adhesive composition will be described. In order to form an adhesive layer having improved adhesion between the polarizer and the transparent protective film and improved optical durability, the active energy ray-curable adhesive composition is used in the present invention as an active energy ray-curable compound. It shall contain (A), an active energy ray-curable compound (B), and an active energy ray-curable compound (C). The SP value of the active energy ray-curable compound (A) is 29.0 (MJ / m ³ ) ^1/2 or more and 32.0 (MJ / m ³ ) ^1/2 or less, and the total amount of the composition is 100% by weight. The composition ratio is 0.0 to 4.0% by weight. Such an active energy ray-curable compound (A) has a high SP value, for example, a PVA polarizer (for example, SP value 32.8) and a saponified triacetyl cellulose (for example, SP value 32.7) as a transparent protective film, It greatly contributes to the improvement of adhesiveness with the adhesive layer. On the other hand, if the content of the active energy ray-curable compound (A) in the active energy ray-curable adhesive composition is large, the optical durability is deteriorated. Therefore, when the total amount of the composition is 100% by weight, the upper limit of the active energy ray-curable compound (A) is preferably 4.0% by weight, more preferably 2.0% by weight. It is preferably 5% by weight, more preferably 1.0% by weight, and particularly preferably no active energy ray curable compound (A).

The SP value of the active energy ray-curable compound (B) is 18.0 (MJ / m ³ ) ^1/2 or more and less than 21.0 (MJ / m ³ ) ^1/2 , and the composition ratio is 5.0 to 98.0% by weight. Such an active energy ray-curable compound (B) has a low SP value and is far away from water (SP value 47.9), which greatly contributes to improving the water resistance of the adhesive layer. When the total amount of the composition is 100% by weight, the composition ratio is preferably 20 to 80% by weight, and more preferably 25 to 70% by weight.

The SP value of the active energy ray-curable compound (C) is 21.0 (MJ / m ³ ) ^1/2 or more and 26.0 (MJ / m ³ ) ^1/2 or less, and the composition ratio is 5.0 to 98.0% by weight. The SP value of the active energy ray-curable compound (C) is close to the SP value (for example, 23.3) of unsaponified triacetyl cellulose as a transparent protective film and the SP value (for example, 22.2) of an acrylic film, for example. It contributes to the improvement of adhesiveness with these transparent protective films. When the total amount of the composition is 100% by weight, the composition ratio is preferably 20 to 80% by weight, and more preferably 25 to 70% by weight.

In the present invention, a specific (ii) transparent protective film and a polarizer are bonded by the above-described (i) active energy ray-curable adhesive composition.

(Ii) As the transparent protective film, a cellulose resin film is used. Cellulosic resin films have a small dimensional change upon thermal shock and a low coefficient of linear expansion. On the other hand, the moisture permeability is high. Therefore, in order to achieve both suppression of deterioration of optical properties in a humidified environment of the polarizing film and excellent crack durability, the cellulose-based resin film has both a positive surface and a negative surface. i) By adhering to a polarizer using an adhesive layer composed of a cured product layer of an active energy ray-curable adhesive composition, the negative side of the cellulose resin film can be compensated and both of the above problems can be achieved.

In particular, in the present invention, the specific (ii) transparent protective film and the thickness are 3 μm or more and 15 μm or less through the adhesive layer composed of the cured layer of the specific (i) active energy ray-curable adhesive composition. When a polarizing film is constructed by adhering a specific (iii) thin polarizer, it is possible to achieve both higher suppression of deterioration of optical properties of the polarizing film in a humidified environment and excellent crack durability at a higher level. preferable.

Schematic of the polarizing film with an adhesive layer which implemented the crack evaluation test.

The polarizing film which concerns on this invention comprises a specific transparent protective film and a polarizer through the adhesive bond layer which consists of a hardened | cured material layer of a specific active energy ray hardening-type adhesive composition, and comprises a polarizing film. To do.

<Active energy ray-curable adhesive composition>
The active energy ray-curable adhesive composition contains active energy ray-curable compounds (A), (B), and (C) as curable components. Specifically, the active energy ray having an SP value of 29.0 (MJ / m ³ ) ^1/2 or more and 32.0 (MJ / m ³ ) ^1/2 or less when the total amount of the composition is 100% by weight. Active energy of 0.0 to 4.0% by weight of curable compound (A) and SP value of 18.0 (MJ / m ³ ) ^1/2 or more and less than 21.0 (MJ / m ³ ) ^1/2 The linear curable compound (B) is 5.0 to 98.0% by weight, and the SP value is 21.0 (MJ / m ³ ) ^1/2 or more and 26.0 (MJ / m ³ ) ^1/2 or less. The active energy ray-curable compound (C) is contained in an amount of 5.0 to 98.0% by weight. In the present invention, the “composition total amount” means the total amount including various initiators and additives in addition to the active energy ray-curable compound.

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

(Calculation method of solubility parameter (SP value))
In the present invention, the solubility parameter (SP value) of an active energy ray-curable compound, a polarizer, various transparent protective films and the like is calculated by Fedors [“Polymer Engineering & Sci.”]. , Vol. 14, No. 2 (1974), pages 148-154]

(Where Δei is the evaporation energy at 25 ° C. belonging to the atom or group, and Δvi is the molar volume at 25 ° C.).

[Delta] ei and [Delta] vi in the above formulas represent constant numerical values given to i atoms and groups in the main molecule. Also, representative examples of numerical values of Δe and Δv given to atoms or groups are shown in Table 1 below.

The active energy ray-curable compound (A) has a radical polymerizable group such as a (meth) acrylate group and has an SP value of 29.0 (MJ / m ³ ) ^1/2 or more and 32.0 (MJ / m). ³ ) ^Any compound that is ^½ or less can be used without limitation. Specific examples of the active energy ray-curable compound (A) include hydroxyethyl acrylamide (SP value 29.5), N-methylol acrylamide (SP value 31.5) and the like. In the present invention, the (meth) acrylate group means an acrylate group and / or a methacrylate group.

The active energy ray-curable compound (B) has a radical polymerizable group such as a (meth) acrylate group and has an SP value of 18.0 (MJ / m ³ ) ^1/2 or more and 21.0 (MJ / m). ³ ) ^Any compound that is less than ^½ can be used without limitation. Specific examples of the active energy ray-curable compound (B) include, for example, tripropylene glycol diacrylate (SP value 19.0), 1,9-nonanediol diacrylate (SP value 19.2), tricyclodecanedi. Methanol diacrylate (SP value 20.3), cyclic trimethylolpropane formal acrylate (SP value 19.1), dioxane glycol diacrylate (SP value 19.4), EO-modified diglycerin tetraacrylate (SP value 20.9) ) And the like. Commercially available products can also be suitably used as the active energy ray-curable compound (B). For example, Aronix M-220 (manufactured by Toagosei Co., Ltd., SP value 19.0), light acrylate 1,9ND-A (Kyoeisha) Chemical company, SP value 19.2), light acrylate DGE-4A (manufactured by Kyoeisha Chemical Co., SP value 20.9), light acrylate DCP-A (manufactured by Kyoeisha Chemical Co., SP value 20.3), SR-531 (Manufactured by SARTOMER, SP value 19.1), CD-536 (manufactured by SARTOMER, SP value 19.4) and the like.

The active energy ray-curable compound (C) has a radical polymerizable group such as a (meth) acrylate group and has an SP value of 21.0 (MJ / m ³ ) ^1/2 or more and 26.0 (MJ / m). ³ ) ^Any compound that is ^½ or less can be used without limitation. Specific examples of the active energy ray-curable compound (C) include, for example, acryloylmorpholine (SP value 22.9), N-methoxymethylacrylamide (SP value 22.9), N-ethoxymethylacrylamide (SP value 22. 3). In addition, a commercial item can also be used suitably as an active energy ray hardening-type compound (C), for example, ACMO (the Kojin company make, SP value 22.9), Wasmer 2MA (the Kasano Kosan company make, SP value 22. 9), Wasmer EMA (manufactured by Kasano Kosan Co., Ltd., SP value 22.3), Wasmer 3MA (manufactured by Kasano Kosan Co., Ltd., SP value 22.4), and the like.

In addition, in this invention, when the acrylic equivalent _{Cae of the} active energy ray-curable adhesive composition represented by the following formula (1) is 140 or more, the active energy ray-curable adhesive composition is cured. Curing shrinkage can be suppressed. This is preferable because adhesion to an adherend, particularly a polarizer, is improved.
C _ae = 1 / Σ (W _N / N _ae ) (1)
In the formula (1), W _N is a mass fraction of the active energy ray-curable compound _N in the composition, and N _ae is an acrylic equivalent of the active energy ray-curable compound N. In addition, in this invention, when the acrylic equivalent of an active energy ray hardening-type adhesive composition is more than predetermined, it can estimate as follows why the adhesive force of the adhesive layer obtained increases.

The higher the acrylic equivalent of the active energy ray-curable adhesive composition is, the more effective it is to suppress the volume shrinkage caused by the formation of covalent bonds when the composition is irradiated with active energy rays and cured. Thereby, the stress collected at the interface between the adhesive layer and the adherend can be relaxed, and as a result, the adhesive force of the adhesive layer is improved.

The acrylic equivalent C _ae is more preferably 155 or more, and further preferably 165 or more. In the present invention, the acrylic equivalent is defined as follows.
(Acrylic equivalent) = (molecular weight of acrylic monomer) / (number of (meth) acryloyl groups contained in one molecule of acrylic monomer)

The active energy ray-curable adhesive composition is an acrylic oligomer obtained by polymerizing a (meth) acrylic monomer in addition to the active energy ray-curable compounds (A), (B) and (C) as curable components. (D) may be contained. By containing the component (D) in the active energy ray-curable adhesive composition, volume shrinkage when the active energy ray is irradiated and cured on the composition is reduced, and the adhesive layer, the polarizer, and the transparent Interfacial stress with an adherend such as a protective film can be reduced. As a result, it is possible to suppress a decrease in adhesiveness between the adhesive layer and the adherend. In order to sufficiently suppress the curing shrinkage of the cured product layer (adhesive layer), the adhesive composition preferably contains 3.0% by weight or more of the acrylic oligomer (D), 5.0% by weight. It is more preferable to contain above. On the other hand, when there is too much content of the acrylic oligomer (D) in adhesive composition, the fall of the reaction rate at the time of irradiating an active energy ray to this composition is intense, and it may become a curing defect. Therefore, the content of the acrylic oligomer (D) in the adhesive composition is preferably 25% by weight or less, and more preferably 15% by weight or less.

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

The active energy ray-curable adhesive composition preferably contains a radical polymerization initiator (E) having a hydrogen abstracting action. According to such a configuration, the adhesiveness of the adhesive layer of the polarizing film is remarkably improved even in a high humidity environment or immediately after being taken out from water (non-dried state). The reason for this is not clear, but the following causes are considered. When the radical polymerization initiator (E) having a hydrogen abstraction action is present in the active energy ray curable adhesive composition, the active energy ray curable compound is polymerized to form a base polymer constituting the adhesive layer. However, hydrogen is extracted from, for example, a methylene group of the active energy ray-curable compound to generate radicals. And the methylene group etc. which the radical generate | occur | produced, and the hydroxyl group of polarizers, such as PVA, react, and a covalent bond is formed between an adhesive bond layer and a polarizer. As a result, it is speculated that the adhesiveness of the adhesive layer of the polarizing film is remarkably improved even in a non-dry state.

In the present invention, examples of the radical polymerization initiator (E) having a hydrogen abstracting action include thioxanthone radical polymerization initiators and benzophenone radical polymerization initiators. Examples of the thioxanthone radical polymerization initiator include compounds represented by the following general formula (2).

(Wherein R ³ and R ⁴ represent —H, —CH ₂ CH ₃ , —iPr or Cl, and R ³ and R ⁴ may be the same or different)

When the compound represented by the general formula (2) is used, the adhesiveness is excellent as compared with the case where a photopolymerization initiator having high sensitivity to light of 380 nm or more is used alone. A photopolymerization initiator that is highly sensitive to light of 380 nm or more will be described later. Among the compounds represented by the general formula (2), diethylthioxanthone in which R ³ and R ⁴ are —CH ₂ CH ₃ is particularly preferable.

Since the photopolymerization initiator of the general formula (2) can initiate polymerization by light having a long wavelength that passes through a transparent protective film having UV absorbing ability, the adhesive can be cured even through the UV absorbing film. Specifically, for example, even when laminating a transparent protective film having UV absorbing ability on both sides like triacetylcellulose-polarizer-triacetylcellulose, when containing a photopolymerization initiator of the general formula (2), Curing of the adhesive composition is possible.

The composition ratio of the radical polymerization initiator (E) having a hydrogen abstracting action in the composition, particularly the composition ratio of the compound represented by the general formula (2), is 0.00 when the total amount of the composition is 100% by weight. It is preferably 1 to 10% by weight, and more preferably 0.2 to 5% by weight.

Further, it is preferable to add a polymerization initiation assistant as necessary. Examples of polymerization initiators include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, etc. Among them, ethyl 4-dimethylaminobenzoate is particularly preferable. When a polymerization initiation assistant is used, its addition amount is usually 0 to 5% by weight, preferably 0 to 4% by weight, most preferably 0 to 3% by weight, when the total amount of the composition is 100% by weight. .

Further, a known photopolymerization initiator can be used in combination as necessary. Since the transparent protective film having UV absorbing ability does not transmit light of 380 nm or less, it is preferable to use a photopolymerization initiator that is highly sensitive to light of 380 nm or more as the photopolymerization initiator. Specifically, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine Oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (Η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole) 1-yl) -phenyl) titanium and the like.

In particular, as a photopolymerization initiator, in addition to the photopolymerization initiator of the general formula (2), a compound represented by the following general formula (3);

Wherein R ⁵ , R ⁶ and R ⁷ are —H, —CH ₃ , —CH ₂ CH ₃ , —iPr or Cl, and R ⁵ , R ⁶ and R ⁷ may be the same or different. It is preferable to contain. By using the photopolymerization initiators of the above general formula (2) and general formula (3) in combination, the reaction becomes highly efficient by these photosensitization reactions, and the adhesiveness of the adhesive layer is particularly improved.

The active energy ray-curable adhesive composition preferably further contains an active energy ray-curable compound having an active methylene group together with a radical polymerization initiator (E) having a hydrogen abstracting action. According to this structure, the adhesiveness of the adhesive bond layer which a polarizing film has further improves.

The active energy ray-curable compound having an active methylene group is a compound having an active double bond group such as a (meth) acryl 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, and a cyanoacetyl group. Specific examples of the active energy ray-curable compound having an active methylene group include 2-acetoacetoxyethyl (meth) acrylate, 2-acetoacetoxypropyl (meth) acrylate, 2-acetoacetoxy-1-methylethyl (meth), for example. Acetoacetoxyalkyl (meth) acrylate such as acrylate; 2-ethoxymalonyloxyethyl (meth) acrylate, 2-cyanoacetoxyethyl (meth) acrylate, N- (2-cyanoacetoxyethyl) acrylamide, N- (2-propionylacetoxy Butyl) acrylamide, N- (4-acetoacetoxymethylbenzyl) acrylamide, N- (2-acetoacetylaminoethyl) acrylamide and the like. In addition, the SP value of the active energy ray-curable compound having an active methylene group is not particularly limited, and a compound having an arbitrary value can be used.

<Photo acid generator>
The active energy ray-curable resin composition may contain a photoacid generator. When the said active energy ray hardening-type resin composition contains a photo-acid generator, the water resistance and durability of an adhesive bond layer can be improved significantly compared with the case where a photo-acid 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 ⁻ represents 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 an anion and SCN-)

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

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

Specifically, “Syracure UVI-6922”, “Syracure UVI-6974” (manufactured by Dow Chemical Japan Co., Ltd.), “Adekaoptomer SP150”, “Adekaoptomer SP152”, “Adekaoptomer” “SP170”, “Adekaoptomer SP172” (manufactured by ADEKA Corporation), “IRGACURE250” (manufactured by Ciba Specialty Chemicals), “CI-5102”, “CI-2855” (manufactured by Nippon Soda Co., Ltd.), “Sun-Aid SI-60L”, “Sun-Aid SI-80L”, “Sun-Aid SI-100L”, “Sun-Aid SI-110L”, “Sun-Aid SI-180L” (manufactured by Sanshin Chemical Co., Ltd.), “CPI-100P”, "CPI-100A" (San Apro Co., Ltd.), "WPI-06 "," WPI-113 "," WPI-116 "," WPI-041 "," WPI-044 "," WPI-054 "," WPI-055 "," WPAG-281 "," WPAG-567 " “WPAG-596” (manufactured by Wako Pure Chemical Industries, Ltd.) is a preferred specific example of the photoacid generator of the present invention.

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

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

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

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

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

The compounding amount of the compound containing either an alkoxy group or an epoxy group is usually 30% by weight or less with respect to the total amount of the composition, and if the content of the compound in the composition is too large, the adhesiveness decreases. In some cases, the impact resistance to the drop test is deteriorated. The content of the compound in the composition is more preferably 20% by weight or less. On the other hand, from the viewpoint of water resistance, the compound preferably contains 2% by weight or more, more preferably 5% by weight or more in the composition.

<Silane coupling agent>
As the silane coupling agent, those having a Si—O bond can be used without any particular limitation. Specific examples thereof include an active energy ray-curable organosilicon compound, or an active energy ray-curable organosilicon compound. Is mentioned. In particular, the organic group of the organosilicon compound preferably has 3 or more carbon atoms. Active energy ray curable compounds include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycid Xylpropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxy Examples thereof include silane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane.

Preferred are 3-methacryloxypropyltrimethoxysilane and 3-acryloxypropyltrimethoxysilane.

As a specific example of the compound that is not active energy ray-curable, a compound having an amino group is preferable. Specific examples of the compound having an amino group include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldi Ethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane, γ- (2- Aminoethyl) aminopropylmethyldiethoxysilane, γ- (2-aminoethyl) aminopropyltriisopropoxysilane, γ- (2- (2-aminoethyl) aminoethyl) aminopropyltrimethoxysilane, γ- (6- Aminohexyl) aminopropyltrimeth Sisilane, 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, Amino group-containing silanes such as (2-aminoethyl) aminomethyltrimethoxysilane, N, N′-bis [3- (trimethoxysilyl) propyl] ethylenediamine; N- (1,3-dimethylbutylidene) -3 -(Triethoxysilane May be mentioned ketimines type silanes such as Le) -1-propanamine.

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

Specific examples of compounds other than the above-described active energy ray-curable compounds include 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (Triethoxysilylpropyl) tetrasulfide, 3-isocyanatopropyltriethoxysilane, imidazolesilane and the like.

The blending amount of the silane coupling agent is preferably in the range of 0.01 to 20% by weight, preferably 0.05 to 15% by weight, and preferably 0.1 to 10% with respect to the total amount of the curable resin composition. More preferably, it is% by weight. This is because when the blending amount exceeds 20% by weight, the storage stability of the curable resin composition is deteriorated, and when it is less than 0.1% by weight, the effect of adhesion water resistance is not sufficiently exhibited.

<Compounds having a vinyl ether group>
When the active energy ray-curable adhesive composition used in the present invention contains a compound having a vinyl ether group, the adhesive water resistance between the polarizer and the adhesive layer is preferably improved. The reason why such an effect is obtained is not clear, but it is presumed that one of the reasons is that the adhesive force between the polarizer and the adhesive layer is increased by the interaction of the vinyl ether group of the compound with the polarizer. The In order to further increase the water resistance of adhesion between the polarizer and the adhesive layer, the compound is preferably an active energy ray-curable compound having a vinyl ether group. The content of the compound is preferably 0.1 to 19% by weight with respect to the total amount of the curable resin composition.

<Additives other than the above>
Moreover, various additives can be mix | blended with the curable resin composition used by this invention as another arbitrary component in the range which does not impair the objective and effect of this invention. Such additives include epoxy resin, polyamide, polyamideimide, polyurethane, polybutadiene, polychloroprene, polyether, polyester, styrene-butadiene block copolymer, petroleum resin, xylene resin, ketone resin, cellulose resin, fluorine-based oligomer, Polymers or oligomers such as silicone oligomers and polysulfide oligomers; polymerization inhibitors such as phenothiazine and 2,6-di-t-butyl-4-methylphenol; polymerization initiators; leveling agents; wettability improvers; Plasticizers; UV absorbers; inorganic fillers; pigments; dyes and the like.

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

<Adhesive layer>
The thickness of the adhesive layer formed by the active energy ray-curable adhesive composition is preferably 0.01 to 3.0 μm. When the thickness of the adhesive layer is too thin, the cohesive force of the adhesive layer is insufficient and the peeling force is lowered, which is not preferable. When the thickness of the adhesive layer is too thick, peeling is likely to occur when stress is applied to the cross section of the polarizing film, and peeling failure due to impact occurs, which is not preferable. The thickness of the adhesive layer is more preferably 0.1 to 2.5 μm, most preferably 0.5 to 1.5 μm.

<Transparent protective film>
In the present invention, a cellulose resin film is used as the transparent protective film. Cellulosic resin film means a film containing cellulose ester such as cellulose acetate as a main component, and is produced by, for example, melt-extrusion using cellulose ester alone and, if necessary, cellulose ester and other polymer components as raw materials. Is done. The term “main component” means that the resin film contains 50% by weight or more of the cellulose ester. In particular, from the viewpoint of improving the crack durability of the polarizing film, 50% by weight of the cellulose ester is used as the transparent protective film. It is preferable to use a cellulose resin film containing at least 70%, particularly a cellulose resin film containing 70% by weight or more of cellulose ester. Cellulose ester is an acetyl obtained by reacting cellulose, which is a natural polymer, with acetic anhydride to replace the hydroxyl group (OH-) contained in the cellulose molecule with an acetyl group (CH ₃ CO-) (acetylation). Cellulose is preferable, and it is particularly preferable to use TAC (triacetyl cellulose) in which all hydroxyl groups are acetylated.

In the present invention, a cellulose resin film containing a retardation may be used as the transparent protective film. In this case, since the transparent protective film also serves as a retardation film, the polarizing film can be thinned, which is preferable. The cellulose resin film containing a retardation is also produced by, for example, melt extrusion molding using cellulose ester alone and, if necessary, cellulose ester and other polymer components as raw materials. The cellulose ester can control the retardation value of the obtained retardation film by changing the type of the substituent of the lower fatty acid and the degree of substitution of the lower fatty acid. Moreover, in order to control a phase difference, a phase difference improvement agent and a phase difference control agent can also be contained. The cellulose ester can be produced by any appropriate method, for example, the method described in JP-A-2001-188128. In addition, many products of cellulose ester are commercially available, which is advantageous in terms of availability and cost. Examples of commercially available cellulose esters include trade names “UV-50”, “UV-80”, “SH-80”, “TD-80U”, “TD-TAC”, “UZ-” manufactured by Fujifilm Corporation. "TAC" and "KC series" manufactured by Konica.

When the cellulose ester contains an acetyl group as a substituent of the lower fatty acid, the degree of acetyl substitution is preferably 3 or less, more preferably 0.5 to 3, particularly preferably 1 to 3. When the cellulose ester contains a propionyl group as a substituent of the lower fatty acid, the propionyl substitution degree is preferably 3 or less, more preferably 0.5 to 3, particularly preferably 1 to 3. Further, when the cellulose ester is a mixed fatty acid ester in which a part of the hydroxyl group of cellulose is substituted with an acetyl group and the other part is substituted with a propionyl group, the sum of the degree of acetyl substitution and the degree of propionyl substitution is Preferably, it is 1 to 3, and more preferably 2 to 3. At this time, the degree of acetyl substitution is preferably 0.5 to 2.5, and the degree of propionyl substitution is preferably 0.3 to 1.5.

In addition, the acetyl substitution degree (or propionyl substitution degree) indicates the number of hydroxyl groups attached to carbons at 2, 3, and 6 positions in the cellulose skeleton with acetyl groups (or propionyl groups). The acetyl group (or propionyl group) may be biased to any of the carbons at the 2, 3, 6 positions in the cellulose skeleton, or may exist on average. The degree of acetyl substitution can be determined by ASTM-D817-91 (test method for cellulose acetate and the like). The propionyl substitution degree can be determined by ASTM-D817-96 (testing method for cellulose acetate and the like).

The cellulose ester preferably has a weight average molecular weight (Mw) measured by a gel permeation chromatograph (GPC) method using a tetrahydrofuran solvent, preferably 30,000 to 500,000, more preferably 50,000 to 400,000, Most preferably, it is 80,000 to 300,000. When the weight average molecular weight is in the above range, a material having excellent mechanical strength, good solubility, moldability, and casting operability can be obtained.

The molecular weight distribution (weight average molecular weight Mw / number average molecular weight Mn) of the cellulose ester is preferably 1.5 to 5.5, and more preferably 2 to 5.

It is preferable that the phase difference-containing cellulose resin film satisfies the relationship of nx> ny> nz. The in-plane retardation of the cellulose resin film containing a retardation is usually controlled in the range of 40 to 300 nm, and the thickness direction retardation is usually controlled in the range of 80 to 320 nm. Further, the in-plane retardation is preferably 40 to 100 nm, the thickness direction retardation is preferably 100 to 320 nm, and the Nz coefficient is preferably 1.8 to 4.5. The Nz coefficient is typically about 3.5 to 4.5. According to such a retardation-containing cellulose resin film, the viewing angle characteristics in the perspective direction can be improved. It is particularly suitable when applied to an IPS mode or VA mode liquid crystal display device. The Nz coefficient is expressed by Nz = (nx−nz) / (nx−ny) (the definitions of nx, ny, and nz are the same as the in-plane retardation and the thickness direction retardation).

Examples of the cellulose resin film containing a retardation include biaxial retardation films satisfying a refractive index relationship of nx> ny> nz (“WVBZ4A6”, “WVBZ4E4” manufactured by Fuji Film, “ KC4DR-1 ") is used. Control of these phase differences can be obtained by uniaxially stretching or biaxially stretching a polymer film containing a cellulose ester in the longitudinal direction or the transverse direction.

The cellulose resin film containing a retardation has an appropriate retardation depending on the purpose of use, such as for the purpose of compensating for coloring or viewing angle due to birefringence of various wavelength plates and liquid crystal layers. It is also possible to laminate two or more types of retardation-containing cellulose resin films and control optical characteristics such as retardation.

One or more kinds of arbitrary appropriate additives may be contained in the transparent protective film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, an anti-coloring agent, a flame retardant, a nucleating agent, an antistatic agent, a pigment, and a coloring agent. The content of the additive in the transparent protective film is preferably 0 to 50% by weight, more preferably 1 to 50% by weight, still more preferably 2 to 40% by weight, and particularly preferably 3 to 30% by weight. If the amount of the additive in the transparent protective film exceeds the above range, the high transparency of the transparent protective film may not be sufficiently exhibited.

The polarizing film according to the present invention may be one in which a transparent protective film is provided on only one surface of the polarizer via an adhesive layer, and the transparent protective film is provided on both surfaces of the polarizer via an adhesive layer. It may be provided. In the former case, a cellulose resin film is used as the transparent protective film. On the other hand, in the latter case, it is necessary to laminate a cellulose resin film as a transparent protective film on one surface of the polarizer via an adhesive layer, but on the other surface, a cellulose resin film as a transparent protective film. Alternatively, a resin film other than the cellulose resin film may be laminated as a transparent protective film.

As the transparent protective film that can be used other than the cellulose resin film, a film having excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is preferable. Examples thereof include polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, acrylic polymers such as polymethyl methacrylate, styrene polymers such as polystyrene and acrylonitrile / styrene copolymer (AS resin), and polycarbonate polymers. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or the above Examples of the polymer that forms the transparent protective film include polymer blends.

Moreover, as a transparent protective film that can be used other than the cellulose resin film, a polymer film described in JP-A-2001-343529 (WO01 / 37007), for example, (A) a substituted and / or unsubstituted imide in the side chain And a resin composition containing a thermoplastic resin having a group and a thermoplastic resin having a substituted and / or unsubstituted phenyl and nitrile group in the side chain. Specific examples include a film of a resin composition containing an alternating copolymer composed of isobutylene and N-methylmaleimide and an acrylonitrile / styrene copolymer. As the film, a film made of a mixed extruded product of the resin composition or the like can be used. Since these films have a small phase difference and a small photoelastic coefficient, problems such as unevenness due to the distortion of the polarizing film can be eliminated, and since the moisture permeability is small, the humidification durability is excellent.

The thickness of the transparent protective film can be determined as appropriate, but is generally preferably 5 to 100 μm from the viewpoints of workability such as strength and handleability and thin layer properties. 10 to 60 μm is particularly preferable, and 13 to 40 μm is more preferable.

<Polarizer>
In the present invention, from the viewpoint of improving crack durability, it is preferable to use a thin polarizer having a thickness of 3 μm or more and 15 μm or less as the polarizer. In particular, from the viewpoint of suppressing the occurrence of through cracks in the polarizer, the thickness is preferably 12 μm or less, more preferably 10 μm or less, and particularly preferably 8 μm or less. Such a thin polarizer has less thickness unevenness, excellent visibility, and less dimensional change, and therefore excellent durability against thermal shock.

A polarizer using a polyvinyl alcohol resin is used. Examples of polarizers include dichroic iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. Examples thereof include those obtained by adsorbing a substance and uniaxially stretched, and polyene-based oriented films such as polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic material such as iodine is preferable.

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

The polarizer preferably contains boric acid from the viewpoint of stretching stability and humidification reliability. The boric acid content contained in the polarizer is preferably 22% by weight or less, more preferably 20% by weight or less, based on the total amount of the polarizer, from the viewpoint of suppressing the occurrence of through cracks. From the viewpoint of stretching stability and humidification reliability, the boric acid content with respect to the total amount of the polarizer is preferably 10% by weight or more, and more preferably 12% by weight or more.

As a thin polarizer, typically, Japanese Patent No. 4751486, Japanese Patent No. 4751481, Japanese Patent No. 4815544, Japanese Patent No. 5048120, International Publication No. 2014/0777599, International Publication No. The thin polarizer described in the publication 2014/077636 pamphlet etc. or the thin polarizer obtained from the manufacturing method described in these can be mentioned.

As the thin polarizer, among the production methods including the step of stretching in the state of a laminate and the step of dyeing, Patent No. 4751486, Patent, in that it can be stretched at a high magnification and the polarization performance can be improved. What is obtained by the manufacturing method including the process of extending | stretching in a boric-acid aqueous solution as described in the 4751481 specification and the patent 4815544 specification is preferable, and it describes especially in the patent 4751481 specification and the patent 4815544 specification. What is obtained by the manufacturing method including the process of extending | stretching in the air auxiliary before extending | stretching in the boric-acid aqueous solution which has this is preferable. These thin polarizers can be obtained by a production method including a step of stretching and dyeing a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a stretching resin base material in a laminated state. With this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching by being supported by the stretching resin substrate.

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

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

Moreover, in the polarizing film which concerns on this invention, the easily bonding layer containing a specific boric acid group containing compound is formed in the at least one bonding surface of a polarizer and a transparent protective film, and this polarizer and a transparent protective film are used. It is good also as a structure laminated | stacked through an adhesive bond layer. According to this configuration, the adhesive property between the polarizer and the transparent protective film and the adhesive layer is good, and the adhesive force is sustainable even under severe conditions such as in a dew condensation environment or in water. A film can be provided.

Specifically, the following general formula (1) is applied to at least one bonding surface of the polarizer and the transparent protective film:

(Wherein X is a functional group containing a reactive group, and R ¹ and R ² are each independently a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, or an aryl group. Or a heterocyclic group), and the compound represented by the general formula (1) is interposed between one or both of the polarizer and the adhesive layer and between the transparent protective film and the adhesive layer. It is preferable to do. Examples of the aliphatic hydrocarbon group include a linear or branched alkyl group which may have a substituent having 1 to 20 carbon atoms, a cyclic alkyl group which may have a substituent having 3 to 20 carbon atoms, carbon Examples of the aryl group include a phenyl group which may have a substituent having 6 to 20 carbon atoms, a naphthyl group which may have a substituent having 10 to 20 carbon atoms, and the like. Examples of the heterocyclic group include, for example, a 5-membered or 6-membered ring group which has at least one hetero atom and may have a substituent. These may be connected to each other to form a ring. In general formula (1), R ¹ and R ² are preferably a hydrogen atom or a linear or branched alkyl group having 1 to 3 carbon atoms, and most preferably a hydrogen atom. In addition, the compound represented by the general formula (1) may be interposed between the polarizer and the adhesive layer and / or between the transparent protective film and the adhesive layer in an unreacted state in the polarizing film. Alternatively, the functional groups may be present in a reacted state. Moreover, "it is equipped with the compound represented by General formula (1) in the bonding surface of at least one of a polarizer and a transparent protective film" means that the compound represented by General formula (1) is this bonding, for example It means that there is at least one molecule on the surface. However, in order to sufficiently improve the adhesive water resistance between the polarizer and the transparent protective film and the adhesive layer, an easy-adhesion composition containing the compound represented by the general formula (1) is used to facilitate adhesion. It is preferable to form a layer on at least a part of the bonding surface, and it is more preferable to form an easy-adhesion layer on the entire surface of the bonding surface.

In the following embodiment, an example in which an easy adhesion layer is formed on at least a part of the bonding surface, that is, a polarizing film in which a transparent protective film is laminated on at least one surface of a polarizer via an adhesive layer. The polarizing film includes an easy-adhesion layer formed using an easy-adhesion composition containing the compound represented by the general formula (1) on at least one bonding surface of the polarizer and the transparent protective film. To do.

X which the compound represented by General formula (1) has is a functional group containing a reactive group, Comprising: It is a functional group which can react with the sclerosing | hardenable component which comprises an adhesive bond layer, As reactive group which X contains For example, hydroxyl group, amino group, aldehyde group, carboxyl group, vinyl group, (meth) acryl group, styryl group, (meth) acrylamide group, vinyl ether group, epoxy group, oxetane group, α, β-unsaturated carbonyl Group, mercapto group, halogen group and the like. When the curable resin composition constituting the adhesive layer is active energy ray curable, the reactive group included in X is a vinyl group, a (meth) acryl group, a styryl group, a (meth) acrylamide group, a vinyl ether group, It is preferably at least one reactive group selected from the group consisting of an epoxy group, an oxetane group, and a mercapto group. In particular, when the curable resin composition constituting the adhesive layer is radically polymerizable, X is The reactive group to be contained is preferably at least one reactive group selected from the group consisting of a (meth) acryl group, a styryl group, and a (meth) acrylamide group, and the compound represented by the general formula (1) Is more preferable because it has a high reactivity and a high copolymerization ratio with the active energy ray-curable resin composition. Moreover, since the polarity of a (meth) acrylamide group is high and it is excellent in adhesiveness, it is preferable also from the point that the effect of this invention can be acquired efficiently. When the curable resin composition constituting the adhesive layer is cationically polymerizable, the reactive group included in X is selected from hydroxyl group, amino group, aldehyde, carboxyl group, vinyl ether group, epoxy group, oxetane group, and mercapto group. It is preferable to have at least one functional group selected, particularly when it has an epoxy group, because it is excellent in adhesion between the resulting curable resin layer and the adherend, and when it has a vinyl ether group, a curable resin composition. Is preferable because of its excellent curability.

Preferable specific examples of the compound represented by the general formula (1) include the following general formula (1 ′)

(Wherein Y is an organic group, and X, R ¹ and R ² are the same as those described above). More preferred are the following compounds (1a) to (1d).

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

In addition to the compounds exemplified above, the compound represented by the general formula (1) includes hydroxyethyl acrylamide and boric acid ester, methylol acrylamide and boric acid ester, hydroxyethyl acrylate and boric acid ester, and hydroxybutyl. Examples include esters of (meth) acrylates and boric acid, such as esters of acrylate and boric acid.

As described above, the polarizing film according to the present invention includes a polarizer and a transparent protective film through an adhesive layer formed by a cured product layer formed by irradiating an active energy ray-curable adhesive composition with active energy rays. Are stacked. In the present invention, in particular, when the active energy ray-curable adhesive composition contains the acrylic oligomer (D), a phase in which these layers continuously change between the transparent protective film and the adhesive layer. A melt layer may be formed. When such a compatible layer is formed, the adhesive force between the transparent protective film and the adhesive layer is improved. However, when the thickness of the compatible layer is P (μm) and the content of the acrylic oligomer (D) when the total amount of the composition is 100% by weight is Q% by weight, the value of P × Q is 10 Is preferably small. In the case of providing such a configuration, the adhesive force between the adhesive layer and the transparent protective film is particularly increased, which is preferable. On the other hand, if the content of the acrylic oligomer (D) is too high, the acrylic oligomer (D) generally has a large molecular weight, and a compatible layer is formed between the adhesive layer and the transparent protective film. At this time, it hardly penetrates into the transparent protective film side, tends to be unevenly distributed at the interface between the adhesive layer and the compatible layer, and as a result, easily becomes a fragile layer. Due to the fragile layer, adhesive fracture is likely to occur. Therefore, when the content of the acrylic oligomer (D) is Q% by weight, at least the value of P × Q can be designed to be smaller than 10. preferable. Moreover, when the compatibilization between the adhesive layer and the transparent protective film proceeds excessively and the thickness P (μm) of the compatible layer becomes too thick, a part of the compatible layer becomes a fragile layer, and the adhesive layer Adhesive strength with the transparent protective film tends to be reduced. For this reason, the thickness P (μm) of the compatible layer is preferably designed so that at least the value of P × Q is smaller than 10.

The polarizing film according to the present invention comprises a coating step of applying the active energy ray-curable adhesive composition described above to at least one surface of the polarizer and the transparent protective film, and the polarizer and the transparent protective film. Through the adhesive layer obtained by irradiating the active energy ray from the polarizer surface side or the transparent protective film surface side and curing the active energy ray-curable adhesive composition, the laminating step to be bonded together, A bonding step of bonding the polarizer and the transparent protective film.

The polarizer and the transparent protective film may be subjected to surface modification treatment before the coating process. In particular, it is preferable to perform a surface modification treatment on the surface of the polarizer. Examples of the surface modification treatment include corona treatment, plasma treatment, excimer treatment, flame treatment and the like, and corona treatment is particularly preferable. By performing the corona treatment, a reactive functional group such as a carbonyl group or an amino group is generated on the surface of the polarizer, and adhesion with the curable resin layer is improved. Moreover, the foreign material on the surface is removed by the ashing effect, or the unevenness on the surface is reduced, so that a polarizing film having excellent appearance characteristics can be created.

<Coating process>
The method of applying the active energy ray-curable adhesive composition is appropriately selected depending on the viscosity of the composition and the desired thickness. For example, a reverse coater, a gravure coater (direct, reverse or offset), a bar reverse coater, Examples include roll coaters, die coaters, bar coaters, and rod coaters. The viscosity of the active energy ray-curable adhesive composition used in the present invention is preferably 3 to 100 mPa · s, more preferably 5 to 50 mPa · s, and most preferably 10 to 30 mPa · s. When the viscosity of the composition is high, the surface smoothness after coating is poor and the appearance is poor, which is not preferable. The active energy ray-curable adhesive composition used in the present invention can be applied by adjusting the viscosity to a preferred range by heating or cooling the composition.

<Bonding process>
A polarizer and a transparent protective film are bonded together through the active energy ray hardening-type adhesive composition applied as mentioned above. Bonding of the polarizer and the transparent protective film can be performed with a roll laminator or the like.

<Adhesion process>
After laminating the polarizer and the transparent protective film, the active energy ray (electron beam, ultraviolet ray, visible light, etc.) is irradiated to cure the active energy ray-curable adhesive composition to form an adhesive layer. The irradiation direction of active energy rays (electron beam, ultraviolet ray, visible light, etc.) can be irradiated from any appropriate direction. Preferably, it irradiates from the transparent protective film side. When irradiated from the polarizer side, the polarizer may be deteriorated by active energy rays (electron beam, ultraviolet ray, visible light, etc.).

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

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

When the polarizing film according to the present invention is produced, active energy rays containing visible light having a wavelength range of 380 nm to 450 nm, particularly active energy rays having the largest irradiation amount of visible light having a wavelength range of 380 nm to 450 nm are used. It is preferable. When using ultraviolet light and visible light, and using a transparent protective film (ultraviolet non-transparent transparent protective film) imparted with ultraviolet absorbing ability, it absorbs light having a wavelength shorter than about 380 nm. Light of a wavelength does not reach the active energy ray curable resin composition and does not contribute to the polymerization reaction. Furthermore, light having a wavelength shorter than 380 nm absorbed by the transparent protective film is converted into heat, and the transparent protective film itself generates heat, which causes defects such as curling and wrinkling of the polarizing film. Therefore, when ultraviolet rays or visible rays are used in the present invention, it is preferable to use an apparatus that does not emit light having a wavelength shorter than 380 nm as the active energy ray generator, and more specifically, integration in the 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. When the polarizing film according to the present invention is manufactured, the active energy ray is preferably a gallium-encapsulated metal halide lamp or an LED light source that emits light in the wavelength range of 380 to 440 nm. Or low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, incandescent lamp, xenon lamp, halogen lamp, carbon arc lamp, metal halide lamp, fluorescent lamp, tungsten lamp, gallium lamp, excimer laser or sunlight A light source including visible light can be used, and ultraviolet light having a wavelength shorter than 380 nm can be blocked using a band pass filter. In order to prevent the polarization film from curling while improving the adhesive performance of the adhesive layer between the polarizer and the transparent protective film, a gallium-encapsulated metal halide lamp can be used and light with a wavelength shorter than 380 nm can be blocked. It is preferable to use an active energy ray obtained through a band pass filter or an active energy ray having a wavelength of 405 nm obtained using an LED light source.

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

The active energy ray-curable adhesive composition used in the present invention is suitably used particularly for forming an adhesive layer for adhering a polarizer and a transparent protective film having a light transmittance of a wavelength of 365 nm of less than 5%. Is possible. Here, the active energy ray-curable resin composition according to the present invention includes the photopolymerization initiator represented by the general formula (2) described above, and is thus irradiated with ultraviolet rays through a transparent protective film having UV absorption ability. The adhesive layer can be formed by curing. Therefore, an adhesive bond layer can be hardened also in a polarizing film which laminated a transparent protective film which has UV absorption ability on both sides of a polarizer. However, as a matter of course, the adhesive layer can also be cured in a polarizing film in which a transparent protective film having no UV absorbing ability is laminated. In addition, the transparent protective film which has UV absorption ability means the transparent protective film whose transmittance | permeability with respect to light of 380 nm is less than 10%.

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

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

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

In the manufacturing method of the polarizing film which concerns on this invention, the easy adhesion which forms the easily bonding layer containing a specific boric acid group containing compound in at least one bonding surface of a polarizer and a transparent protective film before a coating process. A processing step may be provided. Specifically, the following production method;
It is a manufacturing method of the polarizing film by which the transparent protective film was laminated | stacked through the adhesive bond layer on the at least one surface of the polarizer, Comprising: On at least one bonding surface of a polarizer and a transparent protective film, the said general formula ( A curable resin composition on the adhesion surface of at least one of the easy adhesion treatment step of attaching the compound represented by 1), more preferably the compound represented by the general formula (1 ′), and the polarizer and the transparent protective film A curing process is performed by irradiating active energy rays from the polarizer side or the transparent protective film side. It can be manufactured by the manufacturing method of a polarizing film including the adhesion process which adheres a polarizer and a transparent protective film through the adhesive layer obtained by making it.

<Easily bonding process>
As a method for forming an easy-adhesion layer on the bonding surface of at least one of the polarizer and the transparent protective film using an easy-adhesion composition containing the compound represented by the general formula (1), for example, the general formula (1) The easily bonding composition (A) containing the compound represented by this is manufactured, and the method of forming this by apply | coating etc. to at least one bonding surface of a polarizer and a transparent protective film is mentioned. Examples of the easy-adhesive composition (A) that may be contained in addition to the compound represented by the general formula (1) include solvents and additives.

When the easy-adhesive composition (A) contains a solvent, the composition (A) is applied to at least one bonding surface of the polarizer and the transparent protective film, and a drying process or a curing process (such as heat treatment) is performed as necessary. May be performed.

As the solvent that may be contained in the easy-adhesion composition (A), a solvent that can stabilize and dissolve or disperse the compound represented by the general formula (1) is preferable. As the 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 acetylacetone; tetrahydrofuran ( THF), cyclic ethers such as dioxane; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; methanol, ethanol, n-propanol, isopropanol, cyclohexanol Aliphatic or alicyclic alcohols such as; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether; Chi glycol monomethyl ether acetate, glycol ether acetates such as diethylene glycol monoethyl ether acetate; is selected from the like.

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

In addition, when an easily bonding composition (A) contains a polymerization initiator, before laminating | stacking an adhesive bond layer, the compound represented by General formula (1) may react in an easily bonding layer, In some cases, the effect of improving the adhesive water resistance of the polarizing film, which is the purpose of the above, cannot be sufficiently obtained. Therefore, the content of the polymerization initiator in the easy-adhesion layer is preferably less than 2% by weight, more preferably less than 0.5% by weight, and particularly preferably no polymerization initiator is contained.

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

About the method of forming an easily bonding layer on a polarizer using the said easily bonding composition (A), the method of immersing a polarizer directly in the processing bath of a composition (A), and a well-known coating method are used suitably. . Specific examples of the coating method include, but are not limited to, roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, and curtain coating.

In the present invention, if the thickness of the easy-adhesion layer provided in the polarizer is too thick, the cohesive force of the easy-adhesion layer may be reduced, and the easy-adhesion effect may be reduced. Therefore, the thickness of the easy-adhesion layer is preferably 2000 nm or less, more preferably 1000 nm or less, and further preferably 500 nm or less. On the other hand, the lower limit of the thickness for the easy-adhesion layer to sufficiently exert the effect includes at least the thickness of the monomolecular film of the compound represented by the general formula (1), preferably 1 nm or more, more Preferably it is 2 nm or more, More preferably, it is 3 nm or more.

<Optical film>
The polarizing film of the present invention can be used as an optical film laminated with another optical layer in practical use. The optical layer is not particularly limited. For example, a liquid crystal such as a retardation film (including wavelength plates such as 1/2 and 1/4), a visual compensation film, a brightness enhancement film, a reflection plate, and an anti-transmission plate. What becomes an optical layer which may be used for formation of a display apparatus etc. is mention | raise | lifted. These optical layers can be used as a base film of a base film with an easy-adhesion layer in the present invention, and are subjected to surface modification treatment as necessary to react with hydroxyl groups, carbonyl groups, amino groups, and the like. Has a functional group. Therefore, an easy-adhesion-treated retardation film comprising the compound represented by the general formula (1) on at least one surface of the retardation film containing at least a reactive functional group on the surface, particularly the general formula (1). In the retardation film with an easy-adhesion layer formed with an easy-adhesion layer containing the compound represented by the formula, the adhesion between the retardation film and the adhesive layer is improved, and as a result, the adhesiveness is particularly improved. preferable.

As the retardation film, a film having a front retardation of 40 nm or more and / or a thickness direction retardation of 80 nm or more can be used. The front 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, a liquid crystal polymer alignment film, and a liquid crystal polymer alignment layer supported by the film. The thickness of the retardation film is not particularly limited, but is generally about 20 to 150 μm.

As the retardation film, the following formulas (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 formula, 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 retardation of the retardation film. It is in-plane birefringence that is nx-ny when the refractive indexes in the axial direction and the fast axis direction are nx and ny, respectively, and NZ is the refractive index in the thickness direction of the retardation film. An inverse wavelength dispersion type retardation film satisfying (the ratio of nx-nz which is birefringence in the thickness direction and nx-ny which is in-plane birefringence) may be used.

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

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

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

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

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

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

<Preparation of thin polarizer 1>
A polyvinyl alcohol film having an average polymerization degree of 2400 and a saponification degree of 99.9 mol% and a thickness of 30 μm was immersed in warm water at 30 ° C. for 60 seconds to swell. Next, the film was dyed while being immersed in an aqueous solution of 0.3% concentration of iodine / potassium iodide (weight ratio = 0.5 / 8) and stretched to 3.5 times. Then, it extended | stretched so that the total draw ratio might be 6 times in 65 degreeC borate ester aqueous solution. After extending | stretching, it dried for 3 minutes in 40 degreeC oven, and obtained the PVA-type thin polarizer (12 micrometers in thickness).

<Production of thin polarizer 2>
First, a laminated body in which a PVA layer having a thickness of 9 μm is formed on an amorphous PET substrate is produced by air-assisted stretching at a stretching temperature of 130 ° C., and then the stretched laminated body is colored by dyeing. And a colored laminate including a 5 μm-thick PVA layer stretched integrally with an amorphous PET substrate so that the total stretch ratio is 5.94 times by stretching in boric acid water 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-stage stretching are oriented in the higher order, and the iodine adsorbed by the dyeing is oriented in the one direction as the polyiodine ion complex. Thus, an optical film laminate including a PVA layer having a thickness of 5 μm constituting the thin polarizer 2 was obtained.

<Transparent protective film>
Triacetyl cellulose film having a thickness of 25 μm (trade name: TJ25UL, manufactured by Fuji Film) “TAC1”, 40 μm thickness (trade name: TJ40ULF, manufactured by Fuji Film), “TAC2”, having a thickness of 60 μm (product) Name: TG60ULS, manufactured by Fuji Film Co., Ltd.) was used as “TAC3”.
A triacetyl cellulose film with a retardation of 41 μm in thickness (trade name: WVBZ4E4, manufactured by Fuji Film Co., Ltd.) was used as “TAC4”.
An acrylic film having a thickness of 40 μm (trade name: HX-40UC, manufactured by Toyo Kohan Co., Ltd.) was used as “ACRYL”.
A cycloolefin film having a thickness of 13 μm (trade name: ZF14-013, manufactured by Nippon Zeon Co., Ltd.) was used as “COP1”, and a film having a thickness of 25 μm (trade name: ZF14-025, manufactured by Nippon Zeon Co., Ltd.) was used as “COP2”.

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

(Adjustment of active energy ray-curable adhesive composition)
Examples 1 to 10, Comparative Examples 1 to 5
In accordance with the formulation table shown in Table 2, the following components were mixed and stirred at 50 ° C. for 1 hour to obtain active energy ray-curable adhesive compositions used in Examples 1 to 10 and Comparative Examples 1 to 5. Obtained. The numerical values in the table indicate% by weight when the total amount of the composition is 100% by weight.

(1) Active energy ray-curable compound (A) (hereinafter also simply referred to as “component A”)
HEAA (hydroxyethylacrylamide), SP value 29.5, acrylic equivalent 115.15, trade name “HEAA” manufactured by Kojin Co., Ltd. (2) active energy ray-curable compound (B) (hereinafter also simply referred to as “component B”) )
1,9NDA (1,9-nonanediol diacrylate), SP value 19.2, acrylic equivalent 134, trade name “Light Acrylate 1.9ND-A”, DCP-A (Tricyclodecane Dimethanol Di) manufactured by Kyoeisha Chemical Co., Ltd. Acrylate), SP value 20.3, acrylic equivalent 152.19, trade name “light acrylate DCP-A”, HPPA (hydroxypivalate neopentyl glycol acrylic acid adduct), SP value 19.6, acrylic Equivalent 156.18, trade name “Light acrylate HPP-A”, Kyoeisha Chemical Co., Ltd. P2H-A (phenoxydiethylene glycol acrylate), SP value 20.4, acrylic equivalent 236.26, trade name “Light acrylate P2H-A”, Kyoeisha Chemical Co., Ltd. (3) Active energy ray-curable compound (C) Below, simply referred to as "component C")
ACMO (acryloylmorpholine), SP value 22.9, acrylic equivalent 141.17, trade name “ACMO”, 4HBA (4-hydroxybutyl acrylate) manufactured by Kojinsha, SP value 23.8, acrylic equivalent 144.2, Osaka Made by Organic Chemical Industries,
M-5700: 2-hydroxy-3-phenoxypropyl acrylate, SP value 24.4, acrylic equivalent 222.24, trade name “Aronix M-5700”, Toagosei Co., Ltd. (4) polymerized (meth) acrylic monomer Acrylic oligomer (D) (hereinafter also simply referred to as “component D”)
UP1190, trade name “ARUFON UP1190”, manufactured by Toagosei Co., Ltd. (5) boric acid group-containing compound (compound described in general formula (1))
4-vinylphenylboronic acid, acrylic equivalent 180.2
(6) Radical polymerization initiator with hydrogen abstraction KAYACURE DETX-S (diethylthioxanthone, compound described in general formula (2)), trade name “KAYACURE DETX-S”, Nippon Kayaku Co., Ltd. (7) Photopolymerization Initiator IRGACURE907 (2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, compound described in general formula (3)), trade name “IRGACURE907”, manufactured by BASF

(Preparation of Polarizing Film) Example 1 Using a wire bar (No. 2 manufactured by Daiichi Rika Co., Ltd.), the bonding surface of the thin polarizer 1 was treated with 0.1% 4-vinylphenylboronic acid in isopropyl alcohol. An easy-adhesive composition containing 3% by weight was applied and air-dried at 60 ° C. for 1 minute to remove the solvent, thereby producing a thin polarizer 1 having an easy-adhesive layer on one side. Next, an MCD coater (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, number of gravure roll wires: 1000 / inch, rotational speed 140% / line speed) was used for the bonding surface of the transparent protective film. The active energy ray-curable adhesive composition adjusted to the blending amount described in 1 was applied so as to have a thickness of 0.7 μm, and bonded to the surface of the thin polarizer 1 where the easy-adhesion layer was formed using a roll machine. Then, from the bonded transparent protective film side, the active energy ray curing device is irradiated with the visible light to cure the active energy ray-curable adhesive, and then dried with hot air at 70 ° C. for 3 minutes, and transparently protected on one side. A polarizing film having a thin polarizer 1 was obtained. The line speed of bonding was 25 m / min.

(Preparation of polarizing film) Examples 2 to 10, Comparative Examples 1 to 5
Using a wire bar (Daiichi Rika Co., Ltd., No. 2), 4-vinylphenylboronic acid in isopropyl alcohol was added to the surface of the thin polarizer 2 of the optical film laminate including the thin polarizer 2 in an amount of 0.1. An easy-adhesive composition containing 3% by weight was applied and air-dried at 60 ° C. for 1 minute to remove the solvent, thereby producing a polarizer with an easy-adhesive layer. Next, an MCD coater (manufactured by Fuji Machine Co., Ltd.) (cell shape: honeycomb, number of gravure roll wires: 1000 / inch, rotational speed 140% / line speed) is used for the bonding surface of the transparent protective film. The active energy ray-curable adhesive composition adjusted to the blending amount described in 2 was applied so as to have a thickness of 0.7 μm, and bonded to a polarizer with an easy-adhesion layer with a roll. Then, after irradiating the said visible light with the active energy ray irradiation apparatus from the bonded transparent protective film side and hardening an active energy ray hardening-type adhesive agent, it dried with hot air at 70 degreeC for 3 minute (s). Thereafter, the amorphous PET substrate was peeled off to obtain a polarizing film having a thin polarizing film. The line speed of bonding was 25 m / min.

<Measurement of compatible layer thickness>
In order to observe the cross section of the film, the test piece prepared by the ultrathin section method was observed with a transmission electron microscope (TEM) (manufactured by Hitachi, Ltd., product name “H-7650”) at an acceleration voltage of 100 kV. A TEM photograph was taken, the presence of a compatible layer was confirmed, and the thickness was measured.

<Crack evaluation: Heat shock test>
A pressure-sensitive adhesive layer was provided on the transparent protective film side of the polarizing films obtained in Examples and Comparative Examples to prepare a polarizing film with a pressure-sensitive adhesive layer. Using a CO ₂ laser (product name: Laser Pro-SPIRIT), a polarizing film with a pressure-sensitive adhesive layer is placed on the long side of one of the rectangular shapes of 50 mm × 150 mm on the inner side by 14 °. Cut into an angled shape (absorption axis direction is 50 mm). The polarizing film 1 with an adhesive layer having a predetermined shape was bonded to a non-alkali glass having a thickness of 0.5 mm to prepare a sample. The sample was subjected to a heat shock of −40 to 85 ° C. in an environment of 30 minutes × 200 times each, and then A part of the polarizing film 1 with the adhesive layer shown in FIG. 1 (of the polarizing film 1 with the adhesive layer). The presence or absence of the occurrence of through cracks in the V-shaped portion on one long side was confirmed. This test was performed 10 times. When a crack occurred, the mark was evaluated as x. The irradiation conditions of the CO ₂ laser are as follows.
(Irradiation conditions)
Wavelength: 10.6 μm
Laser power: 30W
Oscillation mode: Pulse oscillation Laser beam diameter: 70 μm Laser irradiation surface: protective film side

<Optical durability of polarizing film>
The transmittance and degree of polarization of the produced polarizing film were measured using a spectral transmittance measuring device with an integrating sphere (Dot-3c of Murakami Color Research Laboratory).
The degree of polarization P is the transmittance when two identical polarizing films are overlapped so that their transmission axes are parallel (parallel transmittance: Tp), and overlapped so that their transmission axes are orthogonal to each other. It is calculated | required by applying the transmittance | permeability (orthogonal transmittance | permeability: Tc) at the time of combining to the following formula | equation. Polarization degree P (%) = {(Tp−Tc) / (Tp + Tc)} ^1/2 × 100
Each transmittance is represented by a Y value obtained by correcting visibility with a two-degree field of view (C light source) of JIS Z8701, with 100% of the completely polarized light obtained through the Granteller prism polarizer.
The polarizing film surface of this polarizing film is subjected to corona treatment and bonded with an acrylic adhesive having a thickness of 20 μm, and the other surface of the acrylic adhesive is bonded to an alkali-free glass. The initial value of the rate was measured. Subsequently, this polarizing film with glass was put in an environment of 65 ° C. and 90% RH for 250 hours, and the degree of polarization P and transmittance after the aging of the polarizing film with glass were measured. A value obtained by subtracting the initial polarization degree P from the polarization degree P after the lapse of time is defined as a change in polarization degree (Δ polarization degree P), and a numerical value obtained by subtracting the initial transmittance from the transmittance after the lapse of time is represented by a change in transmittance (Δ transmittance) ). Regarding Δ transmittance, if 1.3 or less, the optical durability is good, and if it exceeds 1.3, it means that the optical durability is deteriorated. Further, regarding the Δ polarization degree P, when it is within −0.1, the optical durability is good, and when it is −0.1 or less, it means that the optical durability is deteriorated.

<Adhesive strength>
The polarizing film was cut into a size of 200 mm parallel to the direction of stretching of the polarizer and 15 mm in the orthogonal direction, and the polarizing film was bonded to a glass plate. Then, cut with a cutter knife between the protective film and the polarizer, and with Tensilon, the protective film and the polarizer are peeled in the 90 ° direction at a peeling speed of 1000 mm / min, and the peel strength (N / 15 mm) is measured. did. When the peel strength exceeds 1.3 (N / 15 mm), the adhesive strength is excellent. When the peel strength is 1.0 to 1.3 (N / mm), the adhesive strength is at a practical level. When it is less than 1.0 (N / mm), it means that the adhesive strength is poor.

Claims

A polarizing film in which a transparent protective film is provided on at least one surface of a polarizer via an adhesive layer,
The transparent protective film is a cellulose resin film,
The adhesive layer is formed by a cured product layer formed by irradiating an active energy ray-curable adhesive composition with active energy rays,
In the active energy ray-curable adhesive composition, when the total amount of the composition is 100% by weight, the SP value is 29.0 (MJ / m 3 ) 1/2 or more and 32.0 (MJ / m 3 ) 1 / 0.0 to 4.0% by weight of the active energy ray-curable compound (A) which is 2 or less, and the SP value is 18.0 (MJ / m 3 ) 1/2 or more and 21.0 (MJ / m 3 ) 1 The active energy ray-curable compound (B) that is less than / 2 is 5.0 to 98.0% by weight, and the SP value is 21.0 (MJ / m 3 ) 1/2 or more and 26.0 (MJ / m 3 ) A polarizing film comprising 5.0 to 98.0% by weight of active energy ray-curable compound (C) which is ½ or less.
The polarizing film according to claim 1, wherein the polarizer has a thickness of 3 μm or more and 15 μm or less.
3. The polarizing film according to claim 1, wherein the active energy ray-curable adhesive composition contains 20 to 80% by weight of the active energy ray-curable compound (B) when the total amount of the composition is 100% by weight. .
The polarizing film according to any one of claims 1 to 3, wherein the active energy ray-curable adhesive composition contains an acrylic oligomer (D) obtained by polymerizing a (meth) acrylic monomer.
The polarizing film according to any one of claims 1 to 4, wherein an acrylic equivalent C ae of the active energy ray-curable adhesive composition represented by the following formula (1) is 140 or more.
C ae = 1 / Σ (W N / N ae ) (1),
In the formula (1), W N is a mass fraction of the active energy ray-curable compound N in the composition, and N ae is an acrylic equivalent of the active energy ray-curable compound N.
6. The polarizing film according to claim 1, wherein the active energy ray-curable adhesive composition contains a radical polymerization initiator having a hydrogen abstracting action.
The polarizing film according to claim 6, wherein the radical polymerization initiator is a thioxanthone radical polymerization initiator.
The active energy ray-curable adhesive composition contains an acrylic oligomer (D),
Between the transparent protective film and the adhesive layer, a compatible layer in which these compositions continuously change is formed,
When the thickness of the compatible layer is P (μm) and the content of the acrylic oligomer (D) when the total amount of the composition is 100% by weight is Q% by weight, the value of P × Q is 10 The polarizing film according to any one of claims 1 to 7, wherein the polarizing film is also small.
On at least one bonding surface of the polarizer and the transparent protective film, the following general formula (1):

(Wherein X is a functional group containing a reactive group, and R 1 and R 2 are each independently a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, or an aryl group. Or represents a heterocyclic group),
The compound represented by the general formula (1) is interposed between one or both of the polarizer and the adhesive layer and the transparent protective film and the adhesive layer. The polarizing film in any one of.
The compound represented by the general formula (1) is represented by the following general formula (1 ′)

The polarizing film according to claim 9, wherein Y is an organic group, and X, R 1 and R 2 are the same as above.
The polarizing film of Claim 9 or 10 provided with the compound represented by the said General formula (1) on the bonding surface of the said polarizer.
The reactive group possessed by the compound represented by the general formula (1) is an α, β-unsaturated carbonyl group, vinyl group, vinyl ether group, epoxy group, oxetane group, amino group, aldehyde group, mercapto group, halogen group. The polarizing film according to any one of claims 9 to 11, which is at least one reactive group selected from the group consisting of:
A coating step of coating the active energy ray-curable adhesive composition on at least one surface of the polarizer and the transparent protective film;
A bonding step of bonding the polarizer and the transparent protective film;
Through the adhesive layer obtained by irradiating active energy rays from the polarizer surface side or the transparent protective film surface side and curing the active energy ray-curable adhesive composition, the polarizer and Including an adhesion step for adhering the transparent protective film, the transparent protective film is a cellulose resin film,
In the active energy ray-curable adhesive composition, when the total amount of the composition is 100% by weight, the SP value is 29.0 (MJ / m 3 ) 1/2 or more and 32.0 (MJ / m 3 ) 1 / 0.0 to 4.0% by weight of the active energy ray-curable compound (A) which is 2 or less, and the SP value is 18.0 (MJ / m 3 ) 1/2 or more and 21.0 (MJ / m 3 ) 1 The active energy ray-curable compound (B) that is less than / 2 is 5.0 to 98.0% by weight, and the SP value is 21.0 (MJ / m 3 ) 1/2 or more and 26.0 (MJ / m 3 ) A method for producing a polarizing film, comprising 5.0 to 98.0% by weight of active energy ray-curable compound (C) that is ½ or less.
The method for producing a polarizing film according to claim 13, wherein the polarizer has a thickness of 3 μm or more and 15 μm or less.
On at least one bonding surface of the polarizer and the transparent protective film, the following general formula (1):

(Wherein X is a functional group containing a reactive group, and R 1 and R 2 are each independently a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, or an aryl group. Or a method for producing a polarizing film according to claim 13, comprising an easy-adhesion treatment step for adhering a heterocyclic group.
The compound represented by the general formula (1) is represented by the following general formula (1 ′)

The method for producing a polarizing film according to any one of claims 13 to 15, wherein Y is an organic group, and X, R 1 and R 2 are the same as described above.
The corona treatment, plasma treatment, excimer treatment or flame treatment is performed on at least one surface of the polarizer and the transparent protective film and on the surface to be bonded before the coating step. The manufacturing method of the polarizing film in any one.
The method for producing a polarizing film according to any one of claims 13 to 17, wherein the active energy ray contains visible light having a wavelength range of 380 to 450 nm.
19. The polarizing film according to claim 13, wherein the active energy ray has a ratio of an integrated illuminance in a wavelength range of 380 to 440 nm and an integrated illuminance in a wavelength range of 250 to 370 nm of 100: 0 to 100: 50. Production method.
An optical film, wherein at least one polarizing film according to any one of claims 1 to 12 is laminated.
An image display device comprising the polarizing film according to any one of claims 1 to 12 and / or the optical film according to claim 20.