WO2020174728A1 - Method for producing polarizing film, polarizing element with highly adhesive layer, polarizing film, optical film, and image display device - Google Patents

Abstract

This method for producing a polarizing film involves providing a transparent protective film to at least one side of a polarizing element, with an adhesive layer interposed therebetween. The method for producing a polarizing film is characterized by having an application step in which the highly adhesive composition is applied to the side of the polarizing element on which the adhesive layer is to be formed, and the highly adhesive composition containing: a specific boron-containing compound; and one or both of an organic solvent having a boiling point of 85°C or higher and a monomer comprising a polymerizable group having a boiling point of 85°C or higher.

Description

Method for producing polarizing film, polarizer with easy-adhesion layer, polarizing film, optical film, and image display device

The present invention relates to a method for producing a polarizing film in which a transparent protective film is provided on at least one surface of a polarizer via an adhesive layer, a polarizer with an easily adhesive layer, and a polarizing film. 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 by itself or as an optical film in which the polarizing film is laminated.

Liquid crystal display devices are rapidly expanding in markets such as watches, mobile phones, PDAs, notebook computers, personal computer monitors, DVD players, and TVs. A liquid crystal display device visualizes a polarization state due to switching of liquid crystal, and a polarizer is used due to its display principle. In particular, in applications such as TVs, higher brightness, higher contrast, and wider viewing angle are required, and polarizing films are also required to have higher transmittance, higher polarization degree, and higher color reproducibility.

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

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

JP 2001-296427 A JP 2012-052000A

The adhesive layer formed using the active energy ray-curable adhesive described in Patent Document 2 is sufficient for a water resistance test for evaluating the presence or absence of color loss and peeling after 6 hours of immersion in 60° C. hot water. Can be cleared. However, in recent years, with respect to the adhesive for polarizing film, for example, it is possible to clear a more severe water resistance test that evaluates the presence or absence of peeling when peeling the end nails after immersing in water (saturation). However, further improvement in water resistance is being demanded. Therefore, the polarizing films that have been reported to date, including the polarizing film using the active energy ray-curable adhesive described in Patent Document 2, have room for further improvement in terms of water-resistant adhesiveness. Met.

Further, in recent years, from the viewpoint of accelerating the production process and reducing process defects, for example, when applying an easy-adhesion composition or an adhesive composition to a substrate, it is required to improve the coatability. .. However, in the case of coating an easily adhesive composition or an adhesive composition while improving the water-resistant adhesiveness of the polarizing film, the actual situation was that there has been no report example of a manufacturing method with improved coatability. ..

The present invention has been developed in view of the above circumstances, when applying the easy-adhesion composition to the adhesive layer forming surface side of the polarizer for improving the water-resistant adhesion of the polarizing film, the coating property An object of the present invention is to provide an improved method for producing a polarizing film.

Furthermore, it is an object to provide a polarizer with an easy-adhesion layer, a polarizing film, an optical film, and an image display device, which are materials for a polarizing film having improved water-resistant adhesion.

　で表される化合物（ただし、Ｘは反応性基を含む官能基であり、Ｒ^１およびＲ^２はそれぞれ独立に、水素原子、置換基を有してもよい、脂肪族炭化水素基、アリール基、またはヘテロ環基を表す）と、沸点が８５℃以上である有機溶剤および沸点が８５℃以上である重合性基を有する単量体のいずれか一方またはその両方と、を含有することを特徴とする偏光フィルムの製造方法に関する。なお、本発明においては、前記一般式（１）に記載の化合物を「ホウ素含有化合物」ともいう。 The above problems can be solved by the following configurations. That is, the present invention is a method for producing a polarizing film in which a transparent protective film is provided on at least one surface of a polarizer via an adhesive layer, wherein the adhesive layer is easily adhered to the adhesive layer forming surface side of the polarizer. There is a coating step of coating the composition, wherein the easily adhesive composition has the following general formula (1):

(Wherein X is a functional group containing a reactive group, R ¹ and R ² are each independently a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group) Or a heterocyclic group) and either one or both of an organic solvent having a boiling point of 85° C. or higher and a monomer having a polymerizable group having a boiling point of 85° C. or higher. And a method for producing a polarizing film. In the present invention, the compound represented by the general formula (1) is also referred to as “boron-containing compound”.

　で表される化合物（ただし、Ｙは有機基であり、Ｘ、Ｒ^１およびＲ^２は前記と同じ）であることが好ましい。 In the method for producing a polarizing film, the compound represented by the general formula (1) is represented by the following general formula (1′).

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

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

In the above method for producing a polarizing film, the water content of the polarizer is preferably 15% by weight or less.

In the above method for producing a polarizing film, it is preferable that the easy-adhesion composition contains water.

In the above method for producing a polarizing film, it is preferable that the coating step is a step of coating the easy-adhesion composition using a post-measurement coating method.

In the above polarizing film manufacturing method, it is preferable that the post-measurement coating method is a gravure roll coating method using a gravure roll.

　で表される化合物（ただし、Ｘは反応性基を含む官能基であり、Ｒ^１およびＲ^２はそれぞれ独立に、水素原子、置換基を有してもよい、脂肪族炭化水素基、アリール基、またはヘテロ環基を表す）と、沸点が８５℃以上である有機溶剤および沸点が８５℃以上である重合性基を有する単量体のいずれか一方またはその両方と、を含有することを特徴とする易接着層付偏光子に関する。 The present invention is also a polarizer with an easy-adhesion layer in which an easy-adhesion layer is formed on at least one surface of the polarizer, wherein the easy-adhesion layer has the following general formula (1):

(Wherein X is a functional group containing a reactive group, R ¹ and R ² are each independently a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group) Or a heterocyclic group) and either one or both of an organic solvent having a boiling point of 85° C. or higher and a monomer having a polymerizable group having a boiling point of 85° C. or higher. And a polarizer with an easily adhesive layer.

　で表される化合物（ただし、Ｙは有機基であり、Ｘ、Ｒ^１およびＲ^２は前記と同じ）であることが好ましい。 In the polarizer with the easily adhesive layer, the compound represented by the general formula (1) has the following general formula (1′).

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

In the polarizer with the easily adhesive layer, the reactive group contained in the compound represented by the general formula (1) is a (meth)acrylamide group, an α,β-unsaturated carbonyl group, a vinyl group, a vinyl ether group, an epoxy group. It is preferably at least one reactive group selected from the group consisting of an oxetane group, an amino group, an aldehyde group, a mercapto group, and a halogen group.

The present invention also provides a polarizing film, characterized in that a transparent protective film is provided on an easily adhesive layer forming surface of the polarizer with an easily adhesive layer described above through an adhesive layer, and the polarizing film. The present invention also relates to an image display device characterized in that at least one optical film is laminated, and further, the polarizing film described above and/or the optical film described above is used.

The method for producing a polarizing film according to the present invention has a coating step of applying an easy-adhesion composition to the side of the polarizer on which the adhesive layer is formed in order to improve the water-resistant adhesion of the polarizing film. As a method of providing an easy-adhesion layer on the polarizer, conventionally, for example, various skeletons having a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a silicone skeleton, a polyamide skeleton, a polyimide skeleton, a polyvinyl alcohol skeleton, a drying property or In consideration of handleability, it has been common to coat a polarizer with an easily adhesive composition containing a low boiling point organic solvent such as isopropanol or water as a diluent. However, in the conventional method, it is difficult to control the drying timing of the low boiling point organic solvent or water blended as a diluent, and when the timing cannot be optimized, the smoothness of the coated surface deteriorates, or the polarizer and coating In some cases, the coating property of the easy-adhesion composition was deteriorated due to deterioration of the peelability from the coating member provided in the apparatus.

However, in the present invention, together with the boron-containing compound represented by the formula (1), one of an organic solvent having a boiling point of 85° C. or higher and a monomer having a polymerizable group having a boiling point of 85° C. or higher, or its Both are blended in the easy-adhesion composition. This makes it possible to improve both the water-resistant adhesiveness of the polarizing film and the coating property when the easily-adhesive composition is applied to the side of the polarizer on which the adhesive layer is formed.

In the easy-adhesion composition, the boron-containing compound represented by the above formula (1) can react with a functional group such as a hydroxyl group included in the polarizer. This makes it possible to improve the adhesiveness between the polarizer and the adhesive layer, and as a result, the effect of improving the water-resistant adhesiveness of the polarizing film is exhibited. Here, when the water content of the polarizer is low, specifically, for example, when the water content of the polarizer is 15% by weight or less, the boron-containing compound cannot sufficiently react with the functional group included in the polarizer. The effect may not be fully obtained. However, even when the water content of the polarizer is low, the reactivity of the boron-containing compound with the functional group of the polarizer is increased by adding water to the easy-adhesion composition, thereby adhering to the polarizer. The adhesiveness with the agent layer can be improved. As a result, even when the water content of the polarizer is low, the water-resistant adhesiveness of the polarizing film is improved, and the coatability is improved when the easily adhesive composition is applied to the adhesive layer forming surface side of the polarizer. Can be compatible.

The method for producing a polarizing film according to the present invention, when the coating step is a step of applying the easy-adhesion composition by using a post-measurement coating method, while improving the water-resistant adhesiveness of the polarizing film, polarization The coatability at the time of applying the easy-adhesion composition to the adhesive layer forming surface of the child can be particularly improved. In the present invention, the “post-measurement coating method” means a method of applying an external force to the liquid film to remove the excess liquid to obtain a predetermined coating film thickness. Specific examples of the post-metering coating method include a gravure roll coating method, a forward roll coating method, an air knife coating method, and a rod/bar coating method. In the present invention, the reason why the above effect is obtained when the coating step is the step of coating the easily adhesive composition by using the post-measurement coating method can be estimated as follows.

With the post-measurement coating method, an external force is applied to the liquid film of the coated easy-adhesion composition, which makes it easy for the easy-adhesion composition to volatilize. As a result, when the excess liquid is removed to obtain a predetermined coating film thickness, the easy-adhesion composition volatilizes more than necessary, and the coating film thickness becomes nonuniform (this phenomenon is also referred to as "transverse coating"). ), or the coating member develops tackiness due to volatilization of the easy-adhesion composition, and a coating member provided in a coating device used in the post-measurement coating system, for example, a gravure roll coating system. For example, the coating film of the easy-adhesion composition develops adhesiveness to the gravure roll, and the peeling property between the polarizer to be coated and the gravure roll deteriorates (this phenomenon is also called "sticking"). May occur. However, in the present invention, it is selected from the group consisting of an organic solvent having a boiling point of 85° C. or higher and a monomer having a polymerizable group, together with the boron-containing compound represented by the formula (1) in the easily adhesive composition. At least one kind is blended. This makes it possible to improve the adhesion between the polarizer and the adhesive layer by the boron-containing compound, reduce the volatilization of the easy-adhesion composition, and prevent the occurrence of lateral damping and sticking. As a result, the method for producing a polarizing film according to the present invention, even when the coating step is a step of applying the easy-adhesion composition using a post-measurement coating method, the water-resistant adhesion of the polarizing film. It is possible to improve the coating property when the easily-adhesive composition is coated on the side of the polarizer on which the adhesive layer is formed, while improving the coating property.

In the polarizer with an easily adhesive layer according to the present invention, the easily adhesive layer is either a boron-containing compound, an organic solvent having a boiling point of 85° C. or higher, and a monomer having a polymerizable group having a boiling point of 85° C. or higher. Have one or both. Therefore, the polarizing film and the optical film provided with the polarizer with such an easy-adhesion layer are excellent in improving the water-resistant adhesiveness. Therefore, the image display device using the polarizing film and/or the optical film according to the present invention is particularly useful in applications where water-resistant adhesiveness is required.

The present invention is a method for producing a polarizing film in which a transparent protective film is provided on at least one surface of a polarizer via an adhesive layer, wherein the adhesive layer-forming surface of the polarizer is an easily adhesive composition. Has a coating step of coating. Hereinafter, the present invention will be specifically described.

　で表される化合物（ただし、Ｘは反応性基を含む官能基であり、Ｒ^１およびＲ^２はそれぞれ独立に、水素原子、置換基を有してもよい、脂肪族炭化水素基、アリール基、またはヘテロ環基を表す）を含有する。前記脂肪族炭化水素基としては、炭素数１～２０の置換基を有してもよい直鎖または分岐のアルキル基、炭素数３～２０の置換基を有してもよい環状アルキル基、炭素数２～２０のアルケニル基が挙げられ、アリール基としては、炭素数６～２０の置換基を有してもよいフェニル基、炭素数１０～２０の置換基を有してもよいナフチル基などが挙げられ、ヘテロ環基としては例えば、少なくとも一つのヘテロ原子を含む、置換基を有してもよい５員環または６員環の基が挙げられる。これらは互いに連結して環を形成してもよい。一般式（１）中、Ｒ^１およびＲ^２として好ましくは、水素原子、炭素数１～３の直鎖または分岐のアルキル基であり、最も好ましくは、水素原子である。なお、一般式（１）で表される化合物は、最終的に製造された偏光フィルム中で、未反応の状態で偏光子と接着剤層との間の易接着層中に存在しても良く、各官能基が反応した状態で存在しても良い。また、本発明においては、偏光子の接着剤層形成面側の全面に易接着組成物を塗工することにより易接着層を形成してもよく、少なくとも一部の面に易接着組成物を塗工することにより易接着層を形成してもよい。 <Easy adhesive composition>
In the present invention, the easily adhesive composition has the following general formula (1):

(Wherein X is a functional group containing a reactive group, R ¹ and R ² are each independently a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group) , Or represents a heterocyclic group). The aliphatic hydrocarbon group may be a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, a cyclic alkyl group having 3 to 20 carbon atoms which may have a substituent, or a carbon atom. Examples thereof include an alkenyl group having 2 to 20 carbon atoms, and examples of the aryl group include a phenyl group having 6 to 20 carbon atoms and optionally a naphthyl group having 10 to 20 carbon atoms. And the heterocyclic group includes, for example, a 5- or 6-membered ring group containing at least one hetero atom and optionally having a substituent. These may be linked to each other to form a ring. In the 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 present in an easily adhesive layer between the polarizer and the adhesive layer in an unreacted state in the finally produced polarizing film. The functional groups may exist in a reacted state. Further, in the present invention, the easy-adhesion layer may be formed by applying the easy-adhesion composition to the entire surface of the adhesive layer forming surface of the polarizer, and the easy-adhesion composition may be formed on at least a part of the surface. The easily adhesive layer may be formed by coating.

X in the compound represented by the general formula (1) is a functional group containing a reactive group, and is a functional group capable of reacting with the curable component constituting the adhesive layer, and as a reactive group contained in X Are, 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. 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 contained in X is a vinyl group, a (meth)acrylic 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, and X is contained particularly when the adhesive composition constituting the adhesive layer is radically polymerizable. The reactive group is preferably at least one reactive group selected from the group consisting of (meth)acrylic group, styryl group and (meth)acrylamide group, and the compound represented by the general formula (1) is It is more preferable to have a (meth)acrylamide group because the reactivity is high and the copolymerization rate with the active energy ray-curable resin composition is increased. In addition, the polarity of the (meth)acrylamide group is high and the adhesiveness is excellent, which is also preferable in that the effect of the present invention can be efficiently obtained. When the curable resin composition constituting the adhesive layer is cationically polymerizable, the reactive group contained in X is a hydroxyl group, an amino group, an aldehyde, a carboxyl group, a vinyl ether group, an epoxy group, an oxetane group or a mercapto group. It is preferable to have at least one functional group selected, particularly when it has an epoxy group, which is excellent in adhesion between the obtained curable resin layer and the adherend, and when it has a vinyl ether group, a curable resin composition. Is preferable because it has excellent curability.

　で表される化合物（ただし、Ｙは有機基であり、Ｘ、Ｒ^１およびＲ^２は前記と同じ）が挙げられる。さらに好適には、以下の化合物（１ａ）～（１ｄ）が挙げられる。 Specific preferred 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 described above). More preferably, the following compounds (1a) to (1d) are mentioned.

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

As the compound represented by the general formula (1), in addition to the above-exemplified compounds, hydroxyethyl acrylamide and boric acid ester, methylol acrylamide and boric acid ester, hydroxyethyl acrylate and boric acid ester, and hydroxybutyl. An ester of (meth)acrylate and boric acid can be exemplified, such as an ester of acrylate and boric acid.

If the content of the compound represented by the general formula (1) in the easy-adhesion composition is too small, the ratio of the compound represented by the general formula (1) present on the surface of the easy-adhesion layer decreases, and the easy-adhesion effect is obtained. May be low. Therefore, the content of the compound represented by the general formula (1) in the easy-adhesion composition is preferably 0.01% by weight or more, more preferably 0.05% by weight or more, and 0.1. It is more preferably 1% by weight or more.

In the present invention, the easily-adhesive composition includes the organic compound having a boiling point of 85°C or higher and the monomer having a polymerizable group having a boiling point of 85°C or higher together with the boron-containing compound represented by the formula (1). Either or both are contained.

Examples of the organic solvent having a boiling point of 85°C or higher include diacetone alcohol (boiling point 166°C), ethylene glycol (boiling point 197.3°C), acetic acid (boiling point 118°C), 1-butanol (boiling point 117°C), 2 -Butanol (boiling point 99.5°C), cyclohexanol (boiling point 161°C), 1-hexanol (boiling point 156.5°C), dipropylene glycol (boiling point 230.5°C), propylene glycol (boiling point 187°C), N, N-dimethylformamide (DMF) (boiling point 153°C), glycerol diacetate (boiling point 280°C), methyl cellosolve (boiling point 124.1°C), tetramethylene sulfone (sulfolane) (boiling point 285°C), glycerol 1,2-carbonate (Boiling point 160° C./0.8 mmHg), N,N-dimethylacetamide (boiling point 165° C.), dimethyl sulfoxide (DMSO) (boiling point 189° C.) and the like. From the viewpoint of coatability, the boiling point of the organic solvent is preferably 90°C or higher, and more preferably 100°C or higher. The upper limit of the boiling point of the organic solvent is not particularly limited, but may be about 300° C., for example.

In the present invention, when the easy-adhesion composition to be used contains the organic solvent, the content thereof is an easy-adhesion composition from the viewpoint of simultaneously improving the adhesiveness between the polarizer and the adhesive layer and improving the coatability. When the total amount of the above is 100% by weight, it is preferably 5 to 80% by weight, and more preferably 10 to 50% by weight. Further, in the present invention, when the easy-adhesion composition used contains the organic solvent, the reactivity of the boron-containing compound with respect to the functional group of the polarizer is increased, and the adhesion between the polarizer and the adhesive layer is improved. From this viewpoint, it is preferable to further contain water, and in that case, the content is preferably 5 to 90% by weight, and 30 to 80% by weight when the total amount of the easily adhesive composition is 100% by weight. More preferably.

Examples of the polymerizable group contained in the monomer having a boiling point of 85° C. or higher include radically polymerizable functional groups of carbon-carbon double bond such as (meth)acryloyl group and vinyl group. Examples of the monomer include acryloylmorpholine (boiling point 158° C.), ethylene glycol diacrylate (n number of ethylene glycol moieties ≈9) (boiling point 197.3° C.), hydroxyethyl acrylamide (boiling point 124° C.), N-vinyl. Pyrrolidone (boiling point 90° C.), acrylic acid (boiling point 141° C.), allyl alcohol (boiling point 97° C.) and the like can be mentioned. From the viewpoint of coatability, the boiling point of the monomer is preferably 90°C or higher, more preferably 100°C or higher. The upper limit of the boiling point of the monomer is not particularly limited, but may be about 300° C., for example.

In the present invention, when the easy-adhesion composition to be used contains the monomer, from the viewpoint of simultaneously improving the adhesiveness between the polarizer and the adhesive layer and improving the coatability, the content thereof is the easy-adhesive composition. When the total amount of the product is 100% by weight, it is preferably 5 to 80% by weight, more preferably 10 to 50% by weight. Further, in the present invention, even when the easy-adhesion composition to be used contains the monomer, the reactivity of the boron-containing compound with respect to the functional group of the polarizer is increased, and the adhesiveness between the polarizer and the adhesive layer is increased. From the viewpoint of improving the water content, it is preferable to further contain water, and in that case, the content is preferably 5 to 90% by weight, and 30 to 80% by weight, based on 100% by weight of the easy-adhesion composition. % Is more preferable.

In the present invention, the easily adhesive composition may contain other additives such as a tackifier, a UV absorber, an antioxidant, a stabilizer such as a heat resistance stabilizer, and the like.

<Easy adhesion layer>
In the method for producing a polarizing film according to the present invention, after the coating step of applying the easy-adhesive composition to the adhesive layer forming surface side of the polarizer, an easy-adhesion layer is provided by providing a drying step or the like if necessary. To form. In the present invention, when the thickness of the easy-adhesion layer included in the polarizer is too large, the cohesive force of the easy-adhesion layer may be decreased, and the easy-adhesion effect may be decreased. Therefore, when the polymerizable monomer volatilizes in the drying step and does not remain in the easy adhesion layer, the thickness of the easy adhesion layer is 300 nm or less, preferably 200 nm or less, and 100 nm or less from the viewpoint of productivity. Is more preferable. On the other hand, the lower limit of the thickness for the easy-adhesion layer to sufficiently exert the effect is at least the thickness of the monomolecular film of the compound represented by the general formula (1), and usually 0.1 nm or more. , Preferably 1 nm or more, more preferably 2 nm or more. When the polymerizable monomer does not volatilize in the drying step and remains in the easy-adhesion layer, the thickness of the easy-adhesion layer is 3 μm or less, preferably 2 μm or less, and 1 μm or less from the viewpoint of productivity. More preferable. On the other hand, the lower limit of the thickness for the easy-adhesion layer to sufficiently exert the effect is at least the thickness of the monomolecular film of the compound represented by the general formula (1), and usually 0.1 nm or more. , Preferably 1 nm or more, more preferably 2 nm or more.

When the content of the compound represented by the general formula (1) in the easy-adhesion layer is too small, the ratio of the compound represented by the general formula (1) present on the surface of the easy-adhesion layer decreases, and the easy-adhesion effect is reduced. It may be low. Therefore, the content of the compound represented by the general formula (1) in the easy-adhesion layer is preferably 0.01% by weight or more, more preferably 0.05% by weight or more, More preferably, it is at least wt %.

<Adhesive layer>
The adhesive layer is formed by curing the adhesive composition. The thickness of the adhesive layer 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 becomes insufficient and the peeling force decreases, which is not preferable. If the thickness of the adhesive layer is too thick, peeling easily occurs 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.

<Adhesive composition>
The modes of curing the adhesive composition can be roughly classified into heat curing and active energy ray curing. Examples of the resin constituting the thermosetting adhesive composition include polyvinyl alcohol resin, epoxy resin, unsaturated polyester, urethane resin, acrylic resin, urea resin, melamine resin, phenol resin and the like, and a curing agent as necessary. Are used together. As the resin constituting the thermosetting adhesive composition, polyvinyl alcohol resin and epoxy resin can be more preferably used. The active energy ray-curable adhesive composition can be roughly classified into electron beam curable agents, ultraviolet ray curable agents, and visible ray curable agents according to the classification by the active energy ray. Further, the form of curing can be classified into a radically polymerizable adhesive composition and a cationically polymerizable adhesive composition. In the present invention, an active energy ray having a wavelength range of 10 nm to less than 380 nm is referred to as an ultraviolet ray, and an active energy ray having a wavelength range of 380 nm to 800 nm is referred to as a visible ray.

In the production of the polarizing film according to the present invention, the adhesive composition is preferably active energy ray curable. Further, it is particularly preferable that the resin is curable with visible light utilizing visible light of 380 nm to 450 nm.

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

　で表される化合物（ただし、Ｒ^３は水素原子またはメチル基であり、Ｒ^４およびＲ^５はそれぞれ独立に、水素原子、アルキル基、ヒドロキシアルキル基、アルコキシアルキル基または環状エーテル基であって、Ｒ^４およびＲ^５は環状複素環を形成してもよい）が挙げられる。アルキル基、ヒドロキシアルキル基、および／またはアルコキシアルキル基のアルキル部分の炭素数は特に限定されないが、例えば１～４個のものが例示される。また、Ｒ^４およびＲ^５が形成してもよい環状複素環は、例えばＮ－アクリロイルモルホリンなどが挙げられる。 As the monofunctional radically polymerizable compound, for example, the following general formula (2):

(Wherein R ³ is a hydrogen atom or a methyl group, R ⁴ and R ⁵ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group or a cyclic ether group, R ⁴ and R ⁵ may form a cyclic heterocycle). The number of carbon atoms of the alkyl moiety of the alkyl group, hydroxyalkyl group, and/or alkoxyalkyl group is not particularly limited, but examples thereof include 1 to 4 carbon atoms. Examples of the cyclic heterocycle which R ⁴ and R ⁵ may form include N-acryloylmorpholine.

Specific examples of the compound represented by the general formula (2) include, for example, N-methyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl( N-alkyl group-containing (meth)acrylamide derivatives such as (meth)acrylamide, N-butyl (meth)acrylamide, N-hexyl (meth)acrylamide; N-methylol (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, N -N-hydroxyalkyl group-containing (meth)acrylamide derivatives such as methylol-N-propane (meth)acrylamide; N-alkoxy group-containing (meth)acrylamide derivatives such as N-methoxymethylacrylamide and N-ethoxymethylacrylamide. To be Examples of the cyclic ether group-containing (meth)acrylamide derivative include a heterocycle-containing (meth)acrylamide derivative in which the nitrogen atom of the (meth)acrylamide group forms a heterocycle, and examples thereof include N-acryloylmorpholine and N-acryloylmorpholine. -Acryloyl piperidine, N-methacryloyl piperidine, N-acryloyl pyrrolidine and the like can be mentioned. Among these, N-hydroxyethylacrylamide and N-acryloylmorpholine are preferably used because of their excellent reactivity, the ability to obtain a cured product with a high elastic modulus, and their excellent adhesiveness to a polarizer. it can.

From the viewpoint of improving adhesiveness and water resistance when the polarizer and the transparent protective film are adhered via an adhesive layer, the content of the compound represented by the general formula (2) in the adhesive composition is 0. It is preferably from 01 to 80% by weight, more preferably from 5 to 40% by weight.

In addition to the compound represented by the general formula (2), the adhesive composition used in the present invention may contain another monofunctional radically polymerizable compound as a curable component. Examples of the monofunctional radically polymerizable compound include various (meth)acrylic acid derivatives having a (meth)acryloyloxy group. Specifically, for example, methyl(meth)acrylate, ethyl(meth)acrylate, n-propyl(meth)acrylate, isopropyl(meth)acrylate, 2-methyl-2-nitropropyl(meth)acrylate, n-butyl( (Meth)acrylate, isobutyl(meth)acrylate, s-butyl(meth)acrylate, t-butyl(meth)acrylate, n-pentyl(meth)acrylate, t-pentyl(meth)acrylate, 3-pentyl(meth)acrylate, 2,2-dimethylbutyl(meth)acrylate, n-hexyl(meth)acrylate, cetyl(meth)acrylate, n-octyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, 4-methyl-2-propylpentyl( Examples thereof include (meth)acrylic acid (C 1-20) alkyl esters such as (meth)acrylate and n-octadecyl (meth)acrylate.

Examples of the (meth)acrylic acid derivative include cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate and cyclopentyl (meth)acrylate; aralkyl (meth)acrylates such as benzyl (meth)acrylate; 2-isobornyl (Meth)acrylate, 2-norbornylmethyl(meth)acrylate, 5-norbornen-2-yl-methyl(meth)acrylate, 3-methyl-2-norbornylmethyl(meth)acrylate, dicyclopentenyl(meth ) Polycyclic (meth)acrylates such as acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate; 2-methoxyethyl (meth)acrylate, 2-ethoxy Such as ethyl (meth)acrylate, 2-methoxymethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethylcarbitol (meth)acrylate, phenoxyethyl (meth)acrylate, alkylphenoxy polyethylene glycol (meth)acrylate Alkoxy group- or phenoxy group-containing (meth)acrylate; and the like. Among these, dicyclopentenyloxyethyl acrylate and phenoxyethyl acrylate are preferable because of their excellent adhesion to various protective films.

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

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

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

In the adhesive composition used in the present invention, among the monofunctional radically polymerizable compounds, a hydroxyl group-containing (meth)acrylate having a high polarity, a carboxyl group-containing (meth)acrylate, a phosphoric acid group-containing (meth)acrylate, etc. When it contains, the adhesion to various substrates is improved. The content of the hydroxyl group-containing (meth)acrylate is preferably 1% by weight to 30% by weight based on the resin composition. If the content is too large, the water absorption rate of the cured product becomes high, and the water resistance may deteriorate. The content of the carboxyl group-containing (meth)acrylate is preferably 1% by weight to 20% by weight based on the resin composition. If the content is too large, the optical durability of the polarizing film is reduced, which is not preferable. Examples of the phosphoric acid group-containing (meth)acrylate include 2-(meth)acryloyloxyethyl acid phosphate, and the content is 0.1% by weight to 10% by weight based on the resin composition. preferable. If the content is too large, the optical durability of the polarizing film is reduced, which is not preferable.

Also, as the monofunctional radically polymerizable compound, a radically polymerizable compound having an active methylene group can be used. The radically polymerizable compound having an active methylene group is a compound having an active double bond group such as a (meth)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, a cyanoacetyl group and the like. The active methylene group is preferably an acetoacetyl group. Specific examples of the radically polymerizable compound having an active methylene group include, for example, 2-acetoacetoxyethyl (meth)acrylate, 2-acetoacetoxypropyl (meth)acrylate, 2-acetoacetoxy-1-methylethyl (meth)acrylate and the like. Acetoacetoxyalkyl(meth)acrylate; 2-ethoxymalonyloxyethyl(meth)acrylate, 2-cyanoacetoxyethyl(meth)acrylate, N-(2-cyanoacetoxyethyl)acrylamide, N-(2-propionylacetoxybutyl) Examples thereof include acrylamide, N-(4-acetoacetoxymethylbenzyl)acrylamide, N-(2-acetoacetylaminoethyl)acrylamide and the like. The radically polymerizable compound having an active methylene group is preferably acetoacetoxyalkyl(meth)acrylate.

Examples of difunctional or higher polyfunctional radically polymerizable compounds include, for example, polyfunctional (meth)acrylamide derivatives N,N'-methylenebis(meth)acrylamide, tripropylene glycol di(meth)acrylate, tetraethylene glycol di. (Meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol diacrylate, 2-ethyl-2-butylpropanediol di(meth ) Acrylate, bisphenol A di(meth)acrylate, bisphenol A ethylene oxide adduct di(meth)acrylate, bisphenol A propylene oxide adduct di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, neopentyl Glycol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, dioxane glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri( (Meth)acrylic acid and polyhydric alcohol such as (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and EO-modified diglycerin tetra(meth)acrylate And 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene. As specific examples, Aronix M-220 (manufactured by Toagosei Co., Ltd.), light acrylate 1,9ND-A (manufactured by Kyoeisha Chemical Co., Ltd.), light acrylate DGE-4A (manufactured by Kyoeisha Chemical Co., Ltd.), light acrylate DCP-A (Kyoeisha Chemical Co., Ltd.) Preferred), SR-531 (available from Sartomer), CD-536 (available from Sartomer), and the like. If necessary, various epoxy (meth)acrylates, urethane (meth)acrylates, polyester (meth)acrylates, various (meth)acrylate-based monomers and the like can be mentioned. The polyfunctional (meth)acrylamide derivative is preferably contained in the adhesive composition because it has a high polymerization rate and is excellent in productivity and is excellent in crosslinkability when the adhesive composition is a cured product.

The radically polymerizable compound is a combination of a monofunctional radically polymerizable compound and a polyfunctional radically polymerizable compound from the viewpoint of achieving both adhesiveness to a polarizer and various transparent protective films and optical durability in a harsh environment. Is preferred. Since the monofunctional radically polymerizable compound has a relatively low liquid viscosity, the liquid viscosity of the resin composition can be reduced by including it in the resin composition. In addition, a monofunctional radically polymerizable compound often has a functional group that exerts various functions, and when incorporated into the resin composition, various functions are exhibited in the resin composition and/or the cured product of the resin composition. Can be made. The polyfunctional radically polymerizable compound is preferably contained in the resin composition because the cured product of the resin composition can be three-dimensionally crosslinked. The ratio of the monofunctional radical-polymerizable compound to the polyfunctional radical-polymerizable compound is such that the polyfunctional radical-polymerizable compound is mixed in the range of 10 to 1000 parts by weight with respect to 100 parts by weight of the monofunctional radical-polymerizable compound. Is preferred.

When using an electron beam or the like as the active energy ray, the radical-polymerizable adhesive composition does not need to contain a photopolymerization initiator, but when using ultraviolet rays or visible light as the active energy ray, adhesion The agent composition preferably contains a photopolymerization initiator.

The photopolymerization initiator when using a radically polymerizable compound is appropriately selected depending on the active energy ray. When curing with ultraviolet light or visible light, a photopolymerization initiator that cleaves ultraviolet light or visible light is used. Examples of the photopolymerization initiator include benzophenone compounds such as benzyl, benzophenone, benzoylbenzoic acid, and 3,3′-dimethyl-4-methoxybenzophenone; 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2 -Propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, α-hydroxycyclohexylphenyl ketone and other aromatic ketone compounds; methoxyacetophenone, 2,2-dimethoxy- Acetophenone compounds such as 2-phenylacetophenone, 2,2-diethoxyacetophenone and 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1; benzoin methyl ether, Benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether and anisoin methyl ether; aromatic ketal compounds such as benzyldimethyl ketal; aromatic sulfonyl chlorides such as 2-naphthalenesulfonyl chloride Compounds; photoactive oxime compounds such as 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, Thioxanthone compounds such as isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone; camphorquinone; halogenated ketones; acylphosphinoxide; acylphosphonate can give.

The compounding amount of the photopolymerization initiator is 20% by weight or less based on the total amount of the adhesive composition. The compounding amount of the photopolymerization initiator is preferably 0.01 to 20% by weight, more preferably 0.05 to 10% by weight, and further preferably 0.1 to 5% by weight.

Further, when the adhesive composition used in the present invention is used with visible light curability containing a radically polymerizable compound as a curable component, a photopolymerization initiator having high sensitivity to light of 380 nm or more is used. It is preferable. The photopolymerization initiator having high sensitivity to light of 380 nm or more will be described later.

（式中、Ｒ^６およびＲ^７は－Ｈ、－ＣＨ_２ＣＨ_３、－ｉＰｒまたはＣｌを示し、Ｒ^６およびＲ^７は同一または異なっても良い）を単独で使用するか、あるいは一般式（３）で表される化合物と後述する３８０ｎｍ以上の光に対して高感度な光重合開始剤とを併用することが好ましい。一般式（３）で表される化合物を使用した場合、３８０ｎｍ以上の光に対して高感度な光重合開始剤を単独で使用した場合に比べて接着性に優れる。一般式（３）で表される化合物の中でも、Ｒ^６およびＲ^７が－ＣＨ_２ＣＨ_３であるジエチルチオキサントンが特に好ましい。硬化性樹脂組成物中の一般式（３）で表される化合物の組成比率は、硬化性樹脂組成物の全量に対して、０．１～５重量％であることが好ましく、０．５～４重量％であることがより好ましく、０．９～３重量％であることがさらに好ましい。 As the photopolymerization initiator, a compound represented by the following general formula (3):

(Wherein R ⁶ and R ⁷ represent —H, —CH ₂ CH ₃ , —iPr or Cl, and R ⁶ and R ⁷ may be the same or different), or they may be used alone or in the general formula ( It is preferable to use the compound represented by 3) in combination with a photopolymerization initiator having high sensitivity to light having a wavelength of 380 nm or more, which will be described later. When the compound represented by the general formula (3) is used, the adhesiveness is excellent as compared with the case where a photopolymerization initiator having high sensitivity to light of 380 nm or more is used alone. Among the compounds represented by the general formula (3), diethylthioxanthone in which R ⁶ and R ⁷ are —CH ₂ CH ₃ is particularly preferable. The composition ratio of the compound represented by the general formula (3) in the curable resin composition is preferably 0.1 to 5% by weight, and 0.5 to 5% by weight based on the total amount of the curable resin composition. It is more preferably 4% by weight, further preferably 0.9 to 3% by weight.

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

Also, a known photopolymerization initiator can be used in combination, if necessary. Since the transparent protective film having UV absorbing ability does not transmit light having a wavelength of 380 nm or less, it is preferable to use a photopolymerization initiator having high sensitivity to light having a wavelength 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.

（式中、Ｒ^８、Ｒ^９およびＲ^１０は－Ｈ、－ＣＨ_３、－ＣＨ_２ＣＨ_３、－ｉＰｒまたはＣｌを示し、Ｒ^８、Ｒ^９およびＲ^１０は同一または異なっても良い）を使用することが好ましい。一般式（４）で表される化合物としては、市販品でもある２－メチル－１－（４－メチルチオフェニル）－２－モルフォリノプロパン－１－オン（商品名：ＩＲＧＡＣＵＲＥ９０７　メーカー：ＢＡＳＦ）が好適に使用可能である。その他、２－ベンジル－２－ジメチルアミノ－１－（４－モルフォリノフェニル）－ブタノン－１（商品名：ＩＲＧＡＣＵＲＥ３６９　メーカー：ＢＡＳＦ）、２－（ジメチルアミノ）－２－［（４－メチルフェニル）メチル］－１－［４－（４－モルホリニル）フェニル］－１－ブタノン（商品名：ＩＲＧＡＣＵＲＥ３７９　メーカー：ＢＡＳＦ）が感度が高いため好ましい。 In particular, as a photopolymerization initiator, in addition to the photopolymerization initiator of the general formula (3), a compound represented by the following general formula (4);

(In the formula, R ⁸ , R ⁹ and R ¹⁰ represent —H, —CH ₃ , —CH ₂ CH ₃ , —iPr or Cl, and R ⁸ , R ⁹ and R ¹⁰ may be the same or different.) Preference is given to using. As the compound represented by the general formula (4), 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (trade name: IRGACURE907 manufacturer: BASF), which is a commercially available product, is preferable. Can be used for. In addition, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (trade name: IRGACURE369 manufacturer: BASF), 2-(dimethylamino)-2-[(4-methylphenyl) Methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone (trade name: IRGACURE379 manufacturer: BASF) is preferable because of its high sensitivity.

In the above adhesive composition, when a radical polymerizable compound having an active methylene group is used as the radical polymerizable compound, it is preferably used in combination with a radical polymerization initiator having a hydrogen abstraction action. According to this structure, the adhesiveness of the adhesive layer of the polarizing film is significantly improved even immediately after taking out from a high humidity environment or water (non-dried state). The reason for this is not clear, but the following causes are considered. That is, the radically polymerizable compound having an active methylene group is incorporated into the main chain and/or side chain of the base polymer in the adhesive layer while polymerizing with the other radically polymerizable compound that constitutes the adhesive layer, thereby adhering. The agent layer is formed. In the polymerization process, when a radical polymerization initiator having a hydrogen abstraction action is present, hydrogen is abstracted from the radical polymerizable compound having an active methylene group to form a methylene group while the base polymer forming the adhesive layer is formed. Radicals are generated. Then, the methylene group in which the radical is generated reacts with the hydroxyl group of the polarizer such as PVA to form a covalent bond between the adhesive layer and the polarizer. As a result, it is speculated that the adhesiveness of the adhesive layer of the polarizing film is significantly improved even in the non-dried state.

In the present invention, examples of the radical polymerization initiator having a hydrogen abstraction action include thioxanthone type radical polymerization initiators and benzophenone type radical polymerization initiators. The radical polymerization initiator is preferably a thioxanthone-based radical polymerization initiator. Examples of the thioxanthone radical polymerization initiator include compounds represented by the above general formula (3). Specific examples of the compound represented by the general formula (3) include thioxanthone, dimethylthioxanthone, diethylthioxanthone, isopropylthioxanthone, and chlorothioxanthone. Among the compounds represented by the general formula (3), diethylthioxanthone in which R ⁶ and R ⁷ are —CH ₂ CH ₃ is particularly preferable.

In the case where the adhesive composition contains a radical polymerizable compound having an active methylene group and a radical polymerization initiator having a hydrogen abstraction action, the active methylene is defined when the total amount of the curable component is 100% by weight. It is preferable that the radical polymerizable compound having a group is contained in an amount of 1 to 50% by weight, and the radical polymerization initiator is contained in an amount of 0.1 to 10% by weight based on the total amount of the curable resin composition.

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

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

In the present invention, the compound represented by the general formula (1), preferably the compound represented by the general formula (1′), and more preferably the compound represented by the general formulas (1a) to (1d) is used as an adhesive. It can be incorporated into the composition. When these compounds are blended in the adhesive composition, the adhesion to the polarizer or the transparent protective film may be improved, which is preferable. From the standpoint of improving the adhesiveness and water resistance of the polarizer and the cured product layer, particularly in the case of adhering the polarizer and the transparent protective film via the adhesive layer, the adhesiveness and water resistance are improved. The content of the compound represented by the general formula (1) is preferably 0.001 to 50% by weight, more preferably 0.1 to 30% by weight, and 1 to 10% by weight. Is most preferred.

The air bubble suppressor is a compound that can lower the surface tension of the adhesive composition when blended in the adhesive composition, and thus has the effect of reducing air bubbles between the adherend and the adherend. Examples of the bubble suppressor include a silicone-based bubble suppressor having a polysiloxane skeleton such as polydimethylsiloxane, a (meth)acrylic bubble suppressor having a (meth)acrylic skeleton obtained by polymerizing a (meth)acrylic acid ester, and the like. When added to the adhesive composition, it reduces the surface tension when it is added to the adhesive composition, such as polyether-based bubble suppressor polymerized with vinyl ether or cyclic ether, and fluorine-based bubble suppressor composed of fluorine-based compound having perfluoroalkyl group. It is possible to use one having the effect of

The air bubble suppressor preferably has a reactive group in the compound. In this case, when laminating the polarizer and the transparent protective film, it is possible to reduce the generation of lamellar bubbles. Examples of the reactive group contained in the bubble suppressor include a polymerizable functional group. Specifically, for example, a radical polymerizable functional group having an ethylenic double bond such as a (meth)acryloyl group, a vinyl group, an allyl group, or glycidyl. Examples thereof include epoxy groups such as groups, oxetane groups, vinyl ether groups, cyclic ether groups, cyclic thioether groups, and cationically polymerizable functional groups such as lactone groups. From the viewpoint of reactivity in the adhesive composition, a bubble suppressor having a double bond as a reactive group is preferable, and a bubble suppressor having a (meth)acryloyl group is more preferable.

Considering the effect of suppressing laminating air bubbles and the effect of improving adhesiveness, silicone-based air bubble suppressing agents are preferable among the above air bubble suppressing agents. Further, among the air bubble suppressors, in view of the adhesiveness of the adhesive layer, those containing a urethane bond or an isocyanurate ring structure in the main chain skeleton or the side chain are preferable. Commercially available products can be preferably used as the silicone-based air bubble suppressor, and examples thereof include "BYK-UV3505" (manufactured by BYK Japan KK) which is an acrylic group-modified polydimethylsiloxane.

In order to achieve both the adhesive force of the obtained adhesive layer and the effect of reducing lami bubbles, the content of the bubble suppressor is 0.01 to 0. It is preferably 6% by weight.

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

The adhesive composition preferably has a low viscosity in consideration of workability and uniformity during coating, and thus it is preferable that the acrylic oligomer obtained by polymerizing the (meth)acrylic monomer also has a low viscosity. .. The acrylic oligomer having a low viscosity and capable of preventing the curing shrinkage of the adhesive layer has a weight average molecular weight (Mw) of 15,000 or less, preferably 10,000 or less, more preferably 5,000 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 is preferably 500 or more, more preferably 1000 or more, It is particularly preferably 1500 or more. Specific examples of the (meth)acrylic monomer constituting the acrylic oligomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, and 2-methyl- 2-nitropropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, S-butyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, t-pentyl (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)acrylic acid (C 1-20) alkyl esters such as (meth)acrylate, 4-methyl-2-propylpentyl (meth)acrylate, 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), polycyclic (meth)acrylate (eg, 2-isobornyl (meth)acrylate) ) Acrylate, 2-norbornylmethyl(meth)acrylate, 5-norbornen-2-yl-methyl(meth)acrylate, 3-methyl-2-norbornylmethyl(meth)acrylate, etc.), hydroxyl group-containing (meth ) Acrylic acid esters (eg, hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2,3-dihydroxypropylmethyl-butyl (meth)methacrylate), alkoxy group or phenoxy group-containing (meth)acryl Acid esters (2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxymethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethylcarbitol (meth)acrylate, phenoxy Ethyl (meth)acrylate, etc., epoxy group-containing (meth)acrylic acid esters (eg, glycidyl (meth)acrylate, etc.), halogen-containing (meth)acrylic acid esters (eg, 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 kinds. Specific examples of the acrylic oligomer include “ARUFON” manufactured by Toagosei Co., Ltd., “Actflow” manufactured by Soken Chemical Co., Ltd., and “JONCRYL” manufactured by BASF Japan.

The above adhesive composition may contain a photo-acid generator. When the adhesive composition contains a photo-acid generator, the water resistance and durability of the adhesive layer can be dramatically improved as compared with the case where the photo-acid generator is not contained. The photoacid generator can be represented by the following general formula (5).

　（ただし、Ｌ^＋は、任意のオニウムカチオンを表す。また、Ｘ^－は、ＰＦ_６ ^－、ＳｂＦ_６ ^－、ＡｓＦ_６ ^－、ＳｂＣｌ_６ ^－、ＢｉＣｌ_５ ^－、ＳｎＣｌ_６ ^－、ＣｌＯ_４ ^－、ジチオカルバメートアニオン、ＳＣＮ^－よりからなる群より選択されるカウンターアニオンを表す。） General formula (5)

(However, L ⁺ represents any onium cation. Further, X ⁻ represents PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , SbCl ₆ ⁻ , BiCl ₅ ⁻ , SnCl ₆ ⁻ , ClO ₄ ⁻ , dithiocarbamate. anion, SCN ^- represents a counter anion selected from the group more consisting).

Next, the counter anion X ⁻ in the general formula (5) will be described.

The counter anion X ⁻ in the general formula (5) is not particularly limited in principle, but a non-nucleophilic anion is preferable. When the counter anion X ⁻ is a non-nucleophilic anion, nucleophilic reactions in cations coexisting in the molecule and various materials used together are unlikely to occur, resulting in the photoacid generator itself represented by the general formula (5). It is possible to improve the temporal stability of the composition and a composition using the same. The non-nucleophilic anion as used herein 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, "Cylacure UVI-6992", "Cyracure UVI-6974" (above, manufactured by Dow Chemical Japan Co., Ltd.), "Adeka Optomer SP150", "Adeka Optomer SP152", "Adeka Optomer" SP170", "ADEKA OPTOMER SP172" (above, manufactured by ADEKA Corporation), "IRGACURE250" (manufactured by Ciba Specialty Chemicals), "CI-5102", "CI-2855" (manufactured by Nippon Soda Co., Ltd.), "Sun-Aid SI-60L", "Sun-Aid SI-80L", "Sun-Aid SI-100L", "Sun-Aid SI-110L", "Sun-Aid SI-180L" (above Sanshin Chemical Co., Ltd.), "CPI-100P", "CPI-100A" (above, San-Apro Co., Ltd.), "WPI-069", "WPI-113", "WPI-116", "WPI-041", "WPI-044", "WPI-054", “WPI-055”, “WPAG-281”, “WPAG-567” and “WPAG-596” (all manufactured by Wako Pure Chemical Industries, Ltd.) are preferred specific examples of the photoacid generator of the present invention.

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

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

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

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

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

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

As other photobase generators, WPBG-018 (trade name: 9-anthrylmethyl N,N'-diethylcarbamate), WPBG-027 (trade name: (E)-1-[3-(2-hydroxyphenyl)-2- propenoyl] piperidine), WPBG-082 (trade name: guanidinium2-(3-benzoylphenyl)propionate), WPBG-140 (trade name: 1-(anthraquinon-2-yl) ethical imidazolase, etc.) You can also

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

When 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 is used, a functional group having reactivity with an epoxy group is used in the molecule. You may use together the compound which has three or more. Examples of the functional group having reactivity with an epoxy group include a carboxyl group, a phenolic hydroxyl group, a mercapto group, a primary or secondary aromatic amino group, and the like. It is particularly preferable to have two or more of these functional groups in one molecule in consideration of three-dimensional curability.

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

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

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 adhesive composition, and if the content of the compound in the composition is too large, the adhesiveness becomes poor. And the impact resistance to the drop test may deteriorate. The content of the compound in the composition is more preferably 20% by weight or less. On the other hand, from the viewpoint of water resistance, the composition preferably contains 2% by weight or more, and more preferably 5% by weight or more.

When the adhesive composition used in the present invention is an active energy ray-curable compound, the silane coupling agent is preferably an active energy ray-curable compound, but is not an active energy ray-curable compound. Similar water resistance can be imparted.

Specific examples of the silane coupling agent include vinyl trichlorosilane, vinyl trimethoxysilane, vinyl triethoxysilane, 2-(3,4 epoxycyclohexyl)ethyl trimethoxysilane, and 3-glycid as the active energy ray-curable compound. Xypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxy Examples thereof include silane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane.

Preferred are 3-methacryloxypropyltrimethoxysilane and 3-acryloxypropyltrimethoxysilane.

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

The silane coupling agent having an amino group may be used alone or in combination of two or more. Of these, γ-aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane and γ-(2-aminoethyl)aminopropylmethyldimethoxysilane are used to ensure good adhesion. , Γ-(2-aminoethyl)aminopropyltriethoxysilane, γ-(2-aminoethyl)aminopropylmethyldiethoxysilane, N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)- 1-propanamine is preferred.

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

Specific examples of silane coupling agents other than the above which are not curable by active energy rays include 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane. Examples thereof include silane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatopropyltriethoxysilane, and imidazolesilane.

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

The adhesive composition used in the present invention may contain a compound that produces keto-enol tautomerism. For example, in an adhesive composition containing a cross-linking agent or an adhesive composition that can be used by blending a cross-linking agent, an embodiment containing a compound that produces the keto-enol tautomerism can be preferably adopted. As a result, it is possible to realize an effect of suppressing an excessive increase in viscosity and gelation of the adhesive composition after the incorporation of the organometallic compound and the generation of a microgel product, and extending the pot life of the composition.

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

The amount of the compound that causes keto-enol tautomerism is, for example, 0.05 to 10 parts by weight, preferably 0.2 to 3 parts by weight (eg 0.3 Parts by weight to 2 parts by weight). When the amount of the above compound used is less than 0.05 parts by weight with respect to 1 part by weight of the organometallic compound, it may be difficult to exhibit a sufficient use effect. On the other hand, when the amount of the compound used exceeds 10 parts by weight with respect to 1 part by weight of the organometallic compound, it may interact with the organometallic compound excessively and it may be difficult to exhibit the desired water resistance.

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

The cyclic molecule is not particularly limited as long as it is a molecule in which a linear molecule is included in the opening in a skewered manner and can move on the linear molecule and has an active energy ray-polymerizable group. In addition, in the present specification, “cyclic” of “cyclic molecule” means substantially “cyclic”. That is, the cyclic molecule may not be completely closed as long as it can move on the linear molecule.

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

In the polyrotaxane used in the present invention, the cyclic molecule has an active energy ray-polymerizable group. As a result, the polyrotaxane and the active energy ray-curable component react with each other to obtain an adhesive whose crosslinking points are movable even after curing. The active energy ray-polymerizable group contained in the cyclic molecule may be any group capable of being polymerized with the active energy ray-curable compound, and examples thereof include radically polymerizable groups such as (meth)acryloyl group and (meth)acryloyloxy group. Can be mentioned.

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

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

A polarizing film using a resin composition containing polyrotaxane as an adhesive has excellent water resistance. The reason why the water resistance of the polarizing film is improved is not clear, but it is presumed as follows. That is, since the cross-linking point can move due to the mobility of the cyclic molecule of polyrotaxane (so-called pulley effect), flexibility is imparted to the cured adhesive, and the adhesion to the surface irregularities of the polarizer is increased. As a result, it is considered that the invasion of water into the interface between the polarizer and the adhesive layer was prevented. Furthermore, it is considered that the fact that the polyrotaxane has a hydrophobic modifying group to impart hydrophobicity to the adhesive also contributed to the prevention of water from entering the interface between the polarizer and the adhesive layer. The content of polyrotaxane is preferably 2% by weight to 50% by weight based on the resin composition.

In the present invention, a cationically polymerizable adhesive composition may be used for forming the adhesive layer. The cationically polymerizable compound used in the cationically polymerizable adhesive composition includes a monofunctional cationically polymerizable compound having one cationically polymerizable functional group in the molecule and two or more cationically polymerizable functional groups in the molecule. It is classified as a polyfunctional cationically polymerizable compound having. Since the monofunctional cationically polymerizable compound has a relatively low liquid viscosity, the liquid viscosity of the resin composition can be reduced by including it in the resin composition. In addition, monofunctional cationically polymerizable compounds often have functional groups that exert various functions, and when incorporated into the resin composition, various functions are exhibited in the resin composition and/or the cured product of the resin composition. Can be made. The polyfunctional cationically polymerizable compound is preferably contained in the resin composition because it can three-dimensionally crosslink the cured product of the resin composition. The ratio of the monofunctional cationically polymerizable compound and the polyfunctional cationically polymerizable compound is such that the polyfunctional cationically polymerizable compound is mixed in the range of 10 parts by weight to 1000 parts by weight with respect to 100 parts by weight of the monofunctional cationically polymerizable compound. Is preferred. Examples of the cationically polymerizable functional group include an epoxy group, an oxetanyl group, and a vinyl ether group. Examples of the compound having an epoxy group include an aliphatic epoxy compound, an alicyclic epoxy compound, and an aromatic epoxy compound.The cationically polymerizable adhesive composition of the present invention has excellent curability and adhesiveness, It is particularly preferable to contain an alicyclic epoxy compound. Examples of the alicyclic epoxy compound include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate modified with caprolactone or trimethylcaprolactone. And valerolactone modified products, and specific examples thereof include Celoxide 2021, Celoxide 2021A, Celoxide 2021P, Celoxide 2081, Celoxide 2083, Celoxide 2085 (all manufactured by Daicel Chemical Industries, Ltd.), Cylacure UVR-6105, Cylacure UVR-. 6107, Syracure 30, R-6110 (above, manufactured by Dow Chemical Japan) and the like. The compound having an oxetanyl group is preferably contained because it has the effects of improving the curability of the cationically polymerizable adhesive composition of the present invention and decreasing the liquid viscosity of the composition. Examples of the compound having an oxetanyl group include 3-ethyl-3-hydroxymethyloxetane, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]benzene, 3-ethyl-3-(phenoxymethyl)oxetane, Di[(3-ethyl-3-oxetanyl)methyl]ether, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, phenol novolac oxetane and the like can be mentioned. Alone oxetane OXT-101, Alone oxetane OXT-121 , Aron oxetane OXT-211, Aron oxetane OXT-221, Aron oxetane OXT-212 (all manufactured by Toagosei Co., Ltd.) and the like are commercially available. The compound having a vinyl ether group is effective in improving the curability of the cationically polymerizable adhesive composition of the present invention and in reducing the liquid viscosity of the composition, and is therefore preferably contained. Examples of the compound having a vinyl ether group include 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 4-hydroxybutyl vinyl ether, vinyl ether of diethylene glycol, triethylene glycol divinyl ether, cyclohexanedimethanol divinyl ether, cyclohexanedimethanol monovinyl ether, tricyclodecane vinyl ether. , Cyclohexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, pentaerythritol type tetravinyl ether and the like.

The cationically polymerizable adhesive composition contains, as a curable component, at least one compound selected from the compound having an epoxy group, the compound having an oxetanyl group, and the compound having a vinyl ether group described above, all of which are cationically polymerized. The photo-cationic polymerization initiator is blended because it is cured by. This cationic photopolymerization initiator generates a cationic species or a Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, and initiates a polymerization reaction of epoxy groups and oxetanyl groups. As the photocationic polymerization initiator, a photoacid generator and a photobase generator can be used, and the photoacid generator described below is preferably used. When the adhesive composition used in the present invention is curable with visible light, it is preferable to use a cationic photopolymerization initiator having high sensitivity to light of 380 nm or more. In general, since it is a compound that exhibits maximum absorption in the wavelength range around 300 nm or shorter, it is possible to add a photosensitizer that exhibits maximum absorption in light of longer wavelength range, specifically, longer than 380 nm. It is possible to promote the generation of cationic species or acid from the photocationic polymerization initiator by being sensitive to light having a wavelength in the vicinity thereof. Examples of the photosensitizer include anthracene compounds, pyrene compounds, carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, photoreducible dyes, and the like. You may use it in mixture of 2 or more types. In particular, the anthracene compound is preferable because it has an excellent photosensitizing effect, and specific examples thereof include Anthracure UVS-1331 and Anthracure UVS-1221 (manufactured by Kawasaki Kasei). The content of the photosensitizer is preferably 0.1% by weight to 5% by weight, and more preferably 0.5% by weight to 3% by weight.

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

Note that thin polarizers generally have a low moisture content, and specifically, the moisture content is often 15% by weight or less. Such a low-moisture-content thin polarizer has the above-mentioned effects, but on the other hand, it has low reactivity with the boron-containing compound contained in the easy-adhesion composition used in the present invention, so that the polarizer and the adhesive layer are The effect of improving the adhesiveness may not be sufficient. Therefore, in the method for producing a polarizing film according to the present invention, when a polarizer having a water content of 15% by weight or less is used, the easily adhesive composition preferably contains water, and specifically, the total amount of the composition. Is 100% by weight, the water content is preferably 5 to 90% by weight, more preferably 30 to 80% by weight.

The polarizer used is a polyvinyl alcohol-based resin. Examples of the polarizer include hydrophilic polymer films such as polyvinyl alcohol film, partially formalized polyvinyl alcohol film, and ethylene/vinyl acetate copolymer partially saponified film, and dichroism of iodine or dichroic dye. Examples include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydration-treated products, polyvinyl chloride dehydrochlorination-treated products, and the like. Among these, a polarizer made of a polyvinyl alcohol film and a dichroic material such as iodine is preferable.

A polarizer in which a polyvinyl alcohol film is dyed with iodine and stretched uniaxially can be produced by, for example, dyeing polyvinyl alcohol by immersing it in an aqueous solution of iodine and stretching it to 3 to 7 times its original length. If necessary, boric acid, zinc sulfate, zinc chloride or the like may be contained, or the solution may be immersed in an aqueous solution of potassium iodide or the like. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed with water before dyeing. By washing the polyvinyl alcohol-based film with water, it is possible to wash the stains and anti-blocking agent on the surface of the polyvinyl alcohol-based film, and by swelling the polyvinyl alcohol-based film, the effect of preventing unevenness such as uneven dyeing is also provided. is there. Stretching may be performed after dyeing with iodine, stretching while dyeing, or stretching and then dyeing with iodine. Stretching can be carried out in an aqueous solution of boric acid or potassium iodide or in a water bath.

It is preferable that the polarizer contains boric acid in terms of stretching stability and humidification reliability. In addition, the content of boric acid contained in the polarizer is preferably 22% by weight or less, and 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 is preferably 10% by weight or more, and more preferably 12% by weight or more, based on the total amount of the polarizer.

As the thin polarizer, typically, Japanese Patent No. 4751486, Japanese Patent No. 4751481, Japanese Patent No. 4815544, Japanese Patent No. 5048120, International Publication No. 2014/077599 pamphlet, international Examples thereof include thin polarizers described in JP-A-2014/077636 pamphlet, and thin polarizers obtained by the manufacturing method described therein.

As the thin polarizer, even in a manufacturing method including a step of stretching and a step of dyeing in the state of a laminated body, in that it can be stretched at a high magnification and the polarization performance can be improved, Japanese Patent No. 4751486 Specification, Patent Those obtained by a production method including a step of stretching in an aqueous solution of boric acid as described in Japanese Patent No. 4751481 and Japanese Patent No. 4815544 are preferable, and particularly, those described in Japanese Patent Nos. 4751481 and 4815544 What is obtained by a production method including a step of auxiliary stretching in the air before stretching in a boric acid aqueous solution is preferable. These thin polarizers can be obtained by a production method including a step of stretching a polyvinyl alcohol-based resin (hereinafter, also referred to as PVA-based resin) layer and a stretching resin base material in a laminate state and a dyeing step. According to this production method, even if the PVA-based resin layer is thin, it can be stretched without trouble such as breakage due to stretching because it is supported by the stretching resin base material.

<Transparent protective film>
As the transparent protective film, one having excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropic property and the like is preferable. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene such as polystyrene and acrylonitrile-styrene copolymer (AS resin). Examples thereof include a polymer and a polycarbonate polymer. Further, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene/propylene copolymer, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers. , Polyether sulfone-based polymer, polyether ether ketone-based polymer, polyphenylene sulfide-based polymer, vinyl alcohol-based polymer, vinylidene chloride-based polymer, vinyl butyral-based polymer, arylate-based polymer, polyoxymethylene-based polymer, epoxy-based polymer, or the above Blends of polymers and the like are also mentioned as examples of the polymer forming the transparent protective film. One or more kinds of any appropriate additive may be contained in the transparent protective film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a release agent, an anti-coloring agent, a flame retardant, a nucleating agent, an antistatic agent, a pigment and a coloring agent. The content of the thermoplastic resin in the transparent protective film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, further preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. .. When the content of the thermoplastic resin in the transparent protective film is 50% by weight or less, the high transparency originally possessed by the thermoplastic resin may not be sufficiently exhibited.

Further, as the transparent protective film, a polymer film described in JP 2001-343529 A (WO01/37007), for example, (A) a thermoplastic resin having a substituted and/or unsubstituted imide group in its side chain, Resin compositions containing a thermoplastic resin having substituted and/or unsubstituted phenyl and nitrile groups in the chain are mentioned. A specific example is a film of a resin composition containing an alternating copolymer of isobutylene and N-methylmaleimide and an acrylonitrile/styrene copolymer. As the film, a film made of a mixed extruded product of a resin composition or the like can be used. Since these films have a small retardation and a small photoelastic coefficient, problems such as unevenness due to distortion of the polarizing film can be eliminated, and the moisture permeability is small, so that they are excellent in humidification durability.

Further, in the present invention, the water vapor permeability of the transparent protective film used is preferably 150 g/m ² /24 h or less. According to this structure, it is difficult for moisture in the air to enter the polarizing film, and it is possible to suppress a change in the moisture content of the polarizing film itself. As a result, curling and dimensional change of the polarizing film caused by the storage environment can be suppressed.

The transparent protective film provided on one side or both sides of the polarizer is preferably one having excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropic property, etc., and particularly a water vapor transmission rate of 150 g/m ² /24 h. The following are more preferable, those of 120 g/m ² /24h or less are particularly preferable, and those of 5 to 70 g/m ² /24h or less are more preferable.

Examples of the material for forming the transparent protective film that satisfies the low moisture permeability include polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate resins; arylate resins; amide resins such as nylon and aromatic polyamides; polyethylene and polypropylene. A polyolefin-based polymer such as ethylene/propylene copolymer, a cyclo-based or cyclic olefin-based resin having a norbornene structure, a (meth)acrylic-based resin, or a mixture thereof can be used. Among the above resins, a polycarbonate resin, a cyclic polyolefin resin, and a (meth)acrylic resin are preferable, and a cyclic polyolefin resin and a (meth)acrylic resin are particularly preferable.

The thickness of the transparent protective film can be appropriately determined, but in general, 5 to 100 μm is preferable from the viewpoint of workability such as strength and handleability, and thin layer property. Particularly, it is preferably 10 to 60 μm, more preferably 13 to 40 μm.

The transparent protective film having a front surface retardation of less than 40 nm and a thickness direction retardation of less than 80 nm is usually used. The front phase difference Re is represented by Re=(nx−ny)×d. The thickness direction retardation Rth is represented by Rth=(nx−nz)×d. The Nz coefficient is represented by Nz=(nx-nz)/(nx-ny). [However, the refractive indexes in the slow axis direction, the fast axis direction, and the thickness direction of the film are nx, ny, and nz, respectively, and d (nm) is the thickness of the film. The slow axis direction is the direction in which the in-plane refractive index of the film is maximized. ]. The transparent protective film preferably has as little color as possible. A protective film having a retardation value in the thickness direction of −90 nm to +75 nm is preferably used. By using a retardation value (Rth) in the thickness direction of −90 nm to +75 nm, coloring of the polarizing film (optical coloring) due to the transparent protective film can be almost eliminated. The retardation value (Rth) in the thickness direction is more preferably −80 nm to +60 nm, particularly preferably −70 nm to +45 nm.

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

Examples of the retardation plate 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 a film. The thickness of the retardation plate is not particularly limited, but is generally about 20 to 150 μm. As the polymer material, for example, polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, polysulfone, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, Polyphenylene sulfide, polyphenylene oxide, polyallyl sulfone, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose resin, cyclic polyolefin resin (norbornene resin), or binary or ternary copolymers thereof, graft copolymer Examples thereof include polymers and blends. These polymer materials become oriented materials (stretched film) by stretching.

Examples of the liquid crystal polymer include various kinds of main chain type and side chain type in which a conjugated linear atomic group (mesogen) that imparts liquid crystal orientation is introduced into the main chain or side chain of the polymer. .. Specific examples of the main chain type liquid crystal polymer include a nematically oriented polyester liquid crystal polymer, a discotic polymer and a cholesteric polymer having a structure in which a mesogenic group is bonded to a spacer portion that imparts flexibility. Specific examples of the side chain type liquid crystal polymer include polysiloxane, polyacrylate, polymethacrylate, or polymalonate as a main chain skeleton, and para-substitution for imparting nematic orientation through a spacer portion composed of a conjugated atomic group as a side chain. Examples thereof include those having a mesogen moiety composed of a cyclic compound unit. These liquid crystal polymers are, for example, those obtained by rubbing the surface of a thin film such as polyimide or polyvinyl alcohol formed on a glass plate, or a solution of the liquid crystalline polymer on the orientation-treated surface such as obliquely vapor-deposited silicon oxide. It is performed by developing and heat treating.

The retardation plate may be one having an appropriate retardation according to the purpose of use such as various wavelength plates or one for the purpose of compensating for the viewing angle and the like due to birefringence of the liquid crystal layer, and may be two or more kinds. It may be one in which retardation plates are laminated to control optical characteristics such as retardation.

The retardation plate has a relationship of nx=ny>nz, nx>ny>nz, nx>ny=nz, nx>nz>ny, nz=nx>ny, nz>nx>ny, nz>nx=ny. Satisfactory ones are selected and used according to various applications. Note that ny=nz includes not only the case where ny and nz are completely the same, but also the case where ny and nz are substantially the same.

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

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

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

The transparent protective film may further be laminated with a peelable base material to supplement its mechanical strength and handleability. The peelable substrate can be peeled from the laminate containing the transparent protective film and the polarizer in a step or in another step before or after attaching the transparent protective film and the polarizer.

Each step in the method for producing a polarizing film according to the present invention will be described below.

The method for producing a polarizing film according to the present invention is a method for producing a polarizing film, in which at least one surface of the polarizer is provided with a transparent protective film via an adhesive layer, and an adhesive layer for the polarizer is formed. There is a coating step of coating the easily adhesive composition on the surface side.

Note that the polarizer and the transparent protective film may be surface-modified before the coating process. Particularly, 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 and flame treatment, and corona treatment is particularly preferable. By performing the corona treatment, reactive functional groups such as carbonyl groups and amino groups are generated on the surface of the polarizer, and the adhesion with the adhesive layer is improved. Further, the ashing effect removes foreign matter on the surface and reduces irregularities on the surface, and thus a polarizing film having excellent appearance characteristics can be produced.

<Coating process of easily adhesive composition>
In the present invention, the easily adhesive composition may be applied to one side of the polarizer, or the easily adhesive composition may be applied to both sides of the polarizer. The method for applying the easy-adhesion composition to the adhesive layer forming surface of the polarizer is appropriately selected depending on the viscosity of the composition and the intended thickness, but removal of foreign matter on the surface of the polarizer and coating property From the viewpoint, it is preferable to use the post-measurement coating method. Specific examples of the post-metering coating method include a gravure roll coating method, a forward roll coating method, an air knife coating method, and a rod/bar coating method. Among these, the gravure roll coating method is particularly preferable from the viewpoint of removing foreign matters on the surface of the polarizer and coating properties.

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

<Drying process of the easily adhesive composition>
In the method for producing a polarizing film according to the present invention, the adhesive layer-forming surface of the polarizer may be coated with the easy-adhesive composition to form a polarizer with an easy-adhesive layer. After the coating step, a polarizer with an easy-adhesion layer may be formed by optionally providing a drying step. As the drying step, a step known to those skilled in the art, for example, an air drying step, a heating step, or a hot air drying step can be used.

The method for producing a polarizing film according to the present invention comprises a step of applying an easy-adhesion composition, and optionally a step of drying the easy-adhesion composition to form a polarizer with an easy-adhesion layer, and then adding an easy-adhesion layer. At least one surface of the easily-adhesive layer forming surface of the polarizer and the transparent protective film, a step of applying an adhesive composition for applying the adhesive composition, and a step of laminating the polarizer and the transparent protective film together. And irradiating an active energy ray from the polarizer surface side or the transparent protective film surface side to bond the polarizer and the transparent protective film to each other via the adhesive layer obtained by curing the adhesive composition. And a process.

<Coating process of adhesive composition>
The method for applying the adhesive composition is appropriately selected depending on the viscosity of the composition and the desired thickness, and examples thereof include a reverse coater, a gravure coater (direct, reverse or offset), a bar reverse coater, a roll coater, and a die coater. , A bar coater, a rod coater and the like.

<Laminating process>
The polarizer and the transparent protective film are bonded together via the adhesive composition coated as described above. The lamination of the polarizer and the transparent protective film can be performed with a roll laminator or the like.

<Adhesion process>
After the polarizer and the transparent protective film are bonded together, active energy rays (electron beam, ultraviolet ray, visible light, etc.) are irradiated to cure the adhesive composition to form an adhesive layer. The active energy ray (electron beam, ultraviolet ray, visible ray, etc.) can be emitted from any appropriate direction. Irradiation is preferably performed from the transparent protective film side. When irradiated from the polarizer side, the polarizer may be deteriorated by active energy rays (electron rays, ultraviolet rays, visible rays, etc.).

The irradiation conditions for irradiating the electron beam can be any appropriate conditions as long as they can cure the adhesive composition. For example, the electron beam irradiation has an acceleration voltage of preferably 5 kV to 300 kV, more preferably 10 kV to 250 kV. If the accelerating voltage is less than 5 kV, the electron beam may not reach the adhesive and the curing may be insufficient. If the accelerating voltage exceeds 300 kV, the penetrating force through the sample is too strong and damages the transparent protective film and the polarizer. May be given. The irradiation dose is 5 to 100 kGy, more preferably 10 to 75 kGy. If the irradiation dose is less than 5 kGy, the adhesive will be insufficiently cured, and if it exceeds 100 kGy, the transparent protective film and the polarizer will be damaged, resulting in a decrease in mechanical strength and yellowing, and obtaining predetermined optical characteristics. I can't.

Electron beam irradiation is usually performed in an inert gas, but if necessary, it may be performed in the atmosphere or under the condition that a small amount of oxygen is introduced. Depending on the material of the transparent protective film, by appropriately introducing oxygen, it is possible to cause oxygen inhibition on the surface of the transparent protective film to which the electron beam first hits, and it is possible to prevent damage to the transparent protective film. The electron beam can be efficiently irradiated.

In the method for producing a polarizing film according to the present invention, an active energy ray containing visible light in the wavelength range of 380 nm to 450 nm, particularly an active energy ray having the largest irradiation amount of the visible light in the wavelength range of 380 nm to 450 nm is used as the active energy ray. It is preferable. When using ultraviolet rays or visible rays, when using a transparent protective film (ultraviolet-ray-impermeable transparent protective film) having an ultraviolet absorbing ability, since it absorbs light having a wavelength shorter than about 380 nm, it is shorter than 380 nm. Light of a wavelength does not reach the adhesive composition and does not contribute to its polymerization reaction. Further, the light having a wavelength shorter than 380 nm absorbed by the transparent protective film is converted into heat, which causes the transparent protective film itself to generate 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 an active energy ray generator, and more specifically, an integrated wavelength range of 380 to 440 nm. The ratio of the illuminance to the integrated illuminance in the wavelength range of 250 to 370 nm is preferably 100:0 to 100:50, and more preferably 100:0 to 100:40. In the method for producing a polarizing film according to the present invention, the active energy ray is preferably a gallium-encapsulated metal halide lamp or an LED light source emitting light in the wavelength range of 380 to 440 nm. Or ultraviolet light such as low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, incandescent lamp, xenon lamp, halogen lamp, carbon arc lamp, metal halide lamp, fluorescent lamp, tungsten lamp, gallium lamp, excimer laser or sunlight. A light source containing visible light may be used, and a bandpass filter may be used to block ultraviolet rays having a wavelength shorter than 380 nm. In order to prevent curling of the polarizing film while improving the adhesive performance of the adhesive layer between the polarizer and the transparent protective film, a gallium-encapsulated metal halide lamp is 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 bandpass filter or an active energy ray having a wavelength of 405 nm obtained by using an LED light source.

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

The adhesive composition used in the present invention can be suitably used particularly when forming an adhesive layer for adhering a polarizer and a transparent protective film having a light transmittance at a wavelength of 365 nm of less than 5%. Here, the adhesive composition used in the present invention contains the photopolymerization initiator represented by the general formula (3) to irradiate ultraviolet rays through the transparent protective film having the UV absorption ability to form an adhesive. The layer can be cured and formed. Therefore, the adhesive layer can be cured even in a polarizing film in which transparent protective films having UV absorbing ability are laminated on both sides of the polarizer. However, as a matter of course, the adhesive layer can be cured also in the polarizing film in which the transparent protective film having no UV absorbing ability is laminated. The transparent protective film having UV absorbing ability means a transparent protective film having a transmittance of 380 nm light of less than 10%.

As a method of imparting UV absorbing ability to the transparent protective film, there are a method of incorporating an ultraviolet absorber in the transparent protective film and a method of laminating a surface treatment layer containing the ultraviolet absorber on the surface of the transparent protective film.

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

When the polarizing film according to the present invention is manufactured in a continuous line, the line speed depends on the curing time of the adhesive composition, but is preferably 1 to 500 m/min, more preferably 5 to 300 m/min, and further preferably 10 to It is 100 m/min. If the line speed is too low, the productivity is poor, or the transparent protective film is damaged too much, so that a polarizing film that can withstand a durability test or the like cannot be produced. If the line speed is too high, the curable resin composition may be insufficiently cured and the desired adhesiveness may not be obtained.

<Optical film>
In practical use, the polarizing film of the present invention can be used as an optical film laminated with another optical layer. Although the optical layer is not particularly limited, for example, a liquid crystal such as a retardation film (including a wave plate such as 1/2 or 1/4), a visual compensation film, a brightness enhancement film, a reflection plate or an anti-transmission plate. Examples thereof include those used as optical layers that are sometimes used for forming display devices and the like.

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

The retardation film includes 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 a film. The thickness of the retardation film is not particularly limited, but is generally about 20 to 150 μm.

The retardation film has the following 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 a retardation of the retardation film. The in-plane birefringence is nx-ny, where nx and ny are the refractive indices in the axial direction and the fast axis direction, respectively, and NZ is the refractive index in the thickness direction of the retardation film when nz is the refractive index. An inverse wavelength dispersion type retardation film satisfying a ratio of nx-nz which is birefringence in the thickness direction and nx-ny which is in-plane birefringence may be used.

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

The adhesive layer may be provided on one side or both sides of the polarizing film or the optical film as a layer in which different compositions or types are laminated. Further, when it is provided on both surfaces, an adhesive layer having different composition, type and thickness may be provided on the front and back of the polarizing film or the optical film. The thickness of the pressure-sensitive adhesive layer can be appropriately determined depending on the purpose of use, adhesive strength, etc., and is generally 1 to 500 μm, preferably 1 to 200 μm, and particularly preferably 1 to 100 μm.

The exposed surface of the adhesive layer is temporarily covered with a separator for the purpose of preventing its contamination until it is put into practical use. As a result, it is possible to prevent contact with the adhesive layer in the usual handling state. As the separator, excluding the above thickness conditions, for example, a plastic film, a rubber sheet, a paper, a cloth, a non-woven fabric, a net, a foamed sheet or a metal foil, an appropriate thin sheet such as a laminate thereof, and a silicone-based or long Appropriate conventional ones such as those coated with an appropriate release agent such as a chain alkyl type, a fluorine type or molybdenum sulfide may be used.

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

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

<Polarizer>
First, a laminate in which a PVA layer having a thickness of 9 μm is formed on an amorphous PET substrate is subjected to auxiliary stretching in air at a stretching temperature of 130° C. to form a stretched laminate, and then the stretched laminate is dyed to obtain a colored laminate. And further comprising a 5 μm-thick PVA layer stretched integrally with the amorphous PET substrate so that the total stretching ratio becomes 5.94 times by stretching in water with boric acid at a stretching temperature of 65° C. An optical film laminate was produced. The PVA molecules in the PVA layer formed on the amorphous PET substrate by such a two-step stretching are highly oriented, and the iodine adsorbed by dyeing is highly oriented in one direction as a polyiodine ion complex. An optical film laminate including a PVA layer having a thickness of 5 μm, which constitutes a thin polarizer, was obtained. The water content of the thin polarizer (PVA layer) was 10% by weight.

<Transparent protective film A>
A twin-screw kneader was prepared by mixing 100 parts by weight of the imidized MS resin described in Production Example 1 of JP-A-2010-284840 and 0.62 parts by weight of a triazine-based UV absorber (manufactured by ADEKA CORPORATION, trade name: T-712). Were mixed at 220° C. to prepare resin pellets. The obtained resin pellet was dried at 100.5 kPa and 100° C. for 12 hours, and extruded from a T-die at a die temperature of 270° C. with a single-screw extruder to form a film (thickness 160 μm). Further, the film is stretched in the conveying direction in an atmosphere of 150° C. (thickness 80 μm), and then an easy adhesive containing an aqueous urethane resin is applied, and then stretched in an atmosphere of 150° C. in a direction orthogonal to the film conveying direction. Thus, a transparent protective film A having a thickness of 40 μm was obtained.

<Transparent protective film B>
As the transparent protective film B, a triacetyl cellulose film having a thickness of 60 μm (Fujitac TG60UL manufactured by Fuji Film Co., Ltd.) was used.

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

(Preparation of easily adhesive composition)
The easily adhesive compositions used in Examples 1 to 10 and Comparative Examples 1 to 3 were prepared according to the compositions shown in Table 1. Details of the raw materials shown in Table 1 are shown below.
(1) Boron-containing compound 3-acrylamidophenylboronic acid; manufactured by Junsei Chemical Co., Ltd. (2) Leveling agent Product name “Olfin EXP.4200”, manufactured by Nissin Chemical Industry Co., Ltd. (3) Polymerizable with a boiling point of 85° C. or higher Monomer having group Acryloylmorpholine (boiling point 158°C); trade name "ACMO", Kojinsha ethylene glycol diacrylate (n number of ethylene glycol sites ≈ 9) (boiling point 197.3°C); trade name "Light" Acrylate 9EG-A", hydroxyethyl acrylamide (boiling point: 124°C) manufactured by Kyoeisha Chemical Co., Ltd.; trade name "HEAA", Kojin Co., Ltd. (4) Organic solvent having a boiling point of 85°C or higher, diacetone alcohol (boiling point: 166°C)
Ethylene glycol (boiling point 197.3°C)
(5) Diluent water (boiling point 100°C)
Isopropyl alcohol (boiling point 82.4°C)

(Coating process of easily adhesive composition)
Using the gravure roll coating method including a gravure roll, the easy-adhesion composition shown in Table 1 was applied to the PVA surface of the optical film laminate including the PVA layer having a thickness of 5 μm of the above polarizer, A polarizer with an easy-adhesion layer was produced by air-drying for 1 minute at ℃. Table 1 shows the thickness before drying (Wet thickness) and the thickness after drying (Dry thickness) at the time of coating the easy-adhesion composition in the coating process of each Example and Comparative Example.

(Coatability evaluation)
In the coating process of each of the examples and comparative examples, the case where no lateral dan was generated during coating was evaluated as ◯, and the case where lateral dan was generated was evaluated as x. Further, the case where the gravure roll and the polarizer were not sticking was evaluated as ◯, and the case where sticking was evaluated as x. The results are shown in Table 1.

(Adjustment of adhesive composition)
Acryloylmorpholine 43.0% by weight, 1,9-nonanediol diacrylate (trade name "Light acrylate 1.9ND-A", manufactured by Kyoeisha Chemical Co., Ltd.) 43.0% by weight based on 100% by weight of the total composition %, an acrylic oligomer obtained by polymerizing a (meth)acrylic monomer (trade name “ARUFON UG4010”, manufactured by Toagosei Co., Ltd.), 9.7% by weight, and a photoinitiator diethylthioxanthone (described in general formula (3)). Compound, trade name "KAYACURE DETX-S", manufactured by Nippon Kayaku Co., Ltd.) 2.9% by weight, photopolymerization initiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1- Adhesion used in Examples and Comparative Examples by mixing 1.4% by weight of ON (the compound described in the general formula (4), trade name “IRGACURE907”, manufactured by BASF) at 50° C. for 1 hour. The agent composition was prepared.

(Production of polarizing film)
On the bonding surface side of the transparent protective film A, an MCD coater (manufactured by Fuji Kikai Co., Ltd.) (cell shape: honeycomb, gravure roll wire number: 1000/inch, rotation speed 140%/line speed) is used for the above adhesion. The agent composition was applied to a thickness of 0.7 μm to form an uncured adhesive layer. Then, using a roll machine, the polarizer with the easy-adhesion layer was attached to the transparent protective film from the side of the easy-adhesion layer. After that, the visible light rays are irradiated from the laminated transparent protective film side by an active energy ray irradiation device to bond the polarizer and the transparent protective film, and then dried with hot air at 70° C. for 3 minutes to obtain a polarizer. The amorphous PET base material laminated on the other side was peeled and removed to obtain a polarizing film having a transparent protective film on one side of the polarizer. The bonding line speed was 25 m/min. For evaluation of water-resistant adhesion, a transparent protective film B was used and a polarizing film was produced by the same method as described above.

(Water resistant adhesion evaluation (initial adhesion))
The obtained polarizing film was cut into a size of 200 mm parallel to the stretching direction of the polarizer and 15 mm in the orthogonal direction, and the polarizing film was attached to a glass plate. Then, a notch is made between the transparent protective film and the polarizer with a cutter knife, and the protective film and the polarizer are peeled off at a peeling speed of 300 mm/min in a 90° direction by a tensilon, and the peeling strength (N/15 mm) is obtained. It was measured. Further, the infrared absorption spectrum of the peeled surface after peeling was measured by the ATR method, and the peeled form was evaluated based on the following criteria. The results are shown in Table 1.
◯: When the material of the transparent protective film is destroyed or when the material of the polarizer is destroyed ×: When the interface between the transparent protective film and the adhesive layer is separated, or when the interface between the polarizer and the adhesive layer is separated

(Water resistant adhesion evaluation (cold water immersion peel test))
The polarizing film obtained in each example was cut into a size of 200 mm parallel to the stretching direction of the polarizer and a size of 20 mm in the orthogonal direction. The polarizing film was immersed in pure water at 23° C. for 24 hours, taken out, and wiped with a dry cloth. Then, a notch was made between the protective film and the polarizer with a cutter knife, and the polarizing film was attached to a glass plate. The transparent protective film and the polarizer were peeled off at a peeling speed of 10 m/min in the 90° direction with Tensilon, and the peeling strength was measured. The above evaluation was performed within 1 minute after taking out the polarizing film from pure water. The results are shown in Table 1.

(Water-resistant adhesion evaluation (harsh cold water immersion peel test))
The polarizing film obtained in each example was cut into a size of 200 mm parallel to the stretching direction of the polarizer and a size of 20 mm in the orthogonal direction. The polarizing film was immersed in pure water at 23° C. for 48 hours, taken out, and wiped with a dry cloth. Then, a notch was made between the protective film and the polarizer with a cutter knife, and the polarizing film was attached to a glass plate. The transparent protective film and the polarizer were peeled off at a peeling speed of 10 m/min in the 90° direction with Tensilon, and the peeling strength was measured. The above evaluation was performed within 1 minute after taking out the polarizing film from pure water. The results are shown in Table 1.

 

 

Claims (13)

At least one surface of the polarizer, a method of manufacturing a polarizing film provided with a transparent protective film through an adhesive layer,
There is a coating step of coating an easily adhesive composition on the adhesive layer forming surface side of the polarizer,
The easily adhesive composition has the following general formula (1):

(Wherein X is a functional group containing a reactive group, R ¹ and R ² are each independently a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group) Or a heterocyclic group) and either one or both of an organic solvent having a boiling point of 85° C. or higher and a monomer having a polymerizable group having a boiling point of 85° C. or higher. And a method for manufacturing a polarizing film. The compound represented by the general formula (1) has the following general formula (1′)

The method for producing a polarizing film according to claim 1, wherein the compound is represented by the formula (wherein Y is an organic group and X, R ¹ and R ² are the same as above). The reactive group contained in the compound represented by the general formula (1) is a (meth)acrylamide group, α,β-unsaturated carbonyl group, vinyl group, vinyl ether group, epoxy group, oxetane group, amino group, aldehyde group. The method for producing a polarizing film according to claim 1, wherein the polarizing film is at least one reactive group selected from the group consisting of, a mercapto group, and a halogen group. The method for producing a polarizing film according to any one of claims 1 to 3, wherein the water content of the polarizer is 15% by weight or less. The method for producing a polarizing film according to any one of claims 1 to 4, wherein the easily adhesive composition contains water. The method for producing a polarizing film according to any one of claims 1 to 5, wherein the coating step is a step of coating the easily adhesive composition using a post-measurement coating method. The method for producing a polarizing film according to claim 6, wherein the post-measurement coating method is a gravure roll coating method using a gravure roll. A polarizer with an easily adhesive layer in which an easily adhesive layer is formed on at least one surface of the polarizer,
The easily adhesive layer has the following general formula (1):

(Wherein X is a functional group containing a reactive group, R ¹ and R ² are each independently a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group) Or a heterocyclic group) and either one or both of an organic solvent having a boiling point of 85° C. or higher and a monomer having a polymerizable group having a boiling point of 85° C. or higher. A polarizer with an easy-adhesion layer. The compound represented by the general formula (1) has the following general formula (1′)

The polarizer with an easy-adhesion layer according to claim 8, which is a compound represented by the formula (wherein Y is an organic group and X, R ¹ and R ² are the same as above). The reactive group contained in the compound represented by the general formula (1) is a (meth)acrylamide group, α,β-unsaturated carbonyl group, vinyl group, vinyl ether group, epoxy group, oxetane group, amino group, aldehyde group. The polarizer with an easy-adhesion layer according to claim 8, which is at least one reactive group selected from the group consisting of a mercapto group, and a halogen group. A polarizing film, characterized in that a transparent protective film is provided on the surface of the polarizer with the easily adhesive layer according to any one of claims 8 to 10 on which the easily adhesive layer is formed, via an adhesive layer. An optical film comprising at least one polarizing film according to claim 11 laminated. An image display device comprising the polarizing film according to claim 11 and/or the optical film according to claim 12.