JP2020134911A - Manufacturing method of polarization film, polarizer with easy-adhesion layer, polarization film, optical film and picture display unit - Google Patents

Abstract

To provide a manufacturing method of a polarization film with coating properties thereof improved, when coating an easy-adhesion composition on an adhesive layer formation surface side of a polarizer in order to improve water-resistant adhesiveness of the polarization film.SOLUTION: There is provided a manufacturing method of a polarization film having a transparent protective film interposing an adhesive layer at least on one surface of a polarizer. The manufacturing method of a polarization film includes a coating process of coating an easy-adhesion composition on an adhesive layer formation surface side of the polarizer. The easy-adhesion composition includes: a prescribed boron-containing compound; and one of or both of an organic solvent with a boiling point of 85°C or higher and a monomer having a polymerizable group with a boiling point of 85°C or higher.SELECTED DRAWING: None

Description

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 the polarizing element via an adhesive layer, a polarizing element with an easy-adhesive layer, and a polarizing film. The polarizing film can form an image display device such as a liquid crystal display (LCD), an organic EL display device, a CRT, or a PDP as an optical film obtained by itself or in which the polarizing films are laminated.

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

As the polarizer, since it has high transmittance and high degree of polarization, for example, an iodine-based polarizer having a stretched structure in which iodine is adsorbed on polyvinyl alcohol (hereinafter, also simply referred to as “PVA”) is the most widely used. It is used. Generally, as the polarizing film, a transparent protective film is bonded to both sides of the polarizing element by a so-called water-based adhesive in which a polyvinyl alcohol-based material is dissolved in water (Patent Document 1 below). As the transparent protective film, triacetyl cellulose having high moisture permeability or the like 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, instead of the water-based adhesive, an active energy ray-curable adhesive has been proposed. 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-based monomer as a curable component (Patent Document 2 below).

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

The adhesive layer formed by using the active energy ray-curable adhesive described in Patent Document 2 is sufficient for a water resistance test for evaluating the presence or absence of color loss and peeling after being immersed in warm water at 60 ° C. for 6 hours, for example. It can be cleared. However, in recent years, the adhesive for polarizing films has been soaked (saturated) in water and then the end nails have been peeled off, for example, to evaluate the presence or absence of peeling, which is sufficient to clear a stricter water resistance test. , Further improvement in water resistance is required. Therefore, there is room for further improvement in terms of water resistance of the polarizing films reported to date, including the polarizing film using the active energy ray-curable adhesive described in Patent Document 2. Met.

Further, in recent years, from the viewpoints of speeding up the production process and reducing process defects, for example, when applying an easy-adhesion composition or an adhesive composition to a base material, it is required to improve the coatability. .. However, when applying an easy-adhesion composition or an adhesive composition while improving the water-resistant adhesiveness of the polarizing film, there has been no report on a manufacturing method with improved coatability. ..

The present invention has been developed in view of the above circumstances, and when the easy-adhesion composition is applied to the adhesive layer forming surface side of the polarizing element in order to improve the water-resistant adhesiveness of the polarizing film, the coatability is improved. It is an object of the present invention to provide an improved method for producing a polarizing film.

Furthermore, it is an object of the present invention to provide a polarizer with an easily adhesive layer, a polarizing film, an optical film, and an image display device, which are materials for a polarizing film having improved water resistance.

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 problem can be solved by the following configuration. That is, the present invention is a method for manufacturing a polarizing film in which a transparent protective film is provided on at least one surface of the polarizing element via an adhesive layer, and is easily adhered to the adhesive layer forming surface side of the polarizer. It has a coating step of coating the composition, and the easy-adhesive composition has the following general formula (1):

Compound represented by (where X is a functional group containing a reactive group, and R ¹ and R ² may independently have a hydrogen atom and a substituent, an aliphatic hydrocarbon group and an aryl group, respectively. , Or a heterocyclic group) and 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. The present invention relates to a method for producing a polarizing film. In the present invention, the compound described in the general formula (1) is also referred to as a "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 the following general formula (1').

It is preferable that the compound is represented by (where 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 method for producing a polarizing film, the water content of the polarizer is preferably 15% by weight or less.

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

In the 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 method for producing a polarizing film, 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。 Further, the present invention is a polarizer with an easy-adhesion layer in which an easy-adhesion layer is formed on at least one surface of the polarizer, and the easy-adhesion layer is the following general formula (1):

Compound represented by (where X is a functional group containing a reactive group, and R ¹ and R ² may independently have a hydrogen atom and a substituent, an aliphatic hydrocarbon group and an aryl group, respectively. , Or a heterocyclic group) and 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. Regarding a hydrocarbon with an easy-adhesion 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 an easy-adhesion layer, the compound represented by the general formula (1) is the following general formula (1').

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

In the polarizer with an easy-adhesion layer, the reactive groups of the compound represented by the general formula (1) are (meth) acrylamide group, α, β-unsaturated carbonyl group, vinyl group, vinyl ether group and epoxy group. , Oxetane group, amino group, aldehyde group, mercapto group, and halogen group are preferably at least one reactive group selected from the group.

Further, the present invention is a polarizing film, the polarizing film, characterized in that a transparent protective film is provided on the easily adhesive layer forming surface of the polarizing element with an easy adhesive layer according to any one of the above via an adhesive layer. However, the present invention relates to an optical film characterized in that at least one sheet is laminated, and further to an image display device characterized in that the above-mentioned polarizing film and / or the above-mentioned optical film is used.

The method for producing a polarizing film according to the present invention includes a coating step of applying an easy-adhesion composition to the adhesive layer forming surface side of the polarizer in order to improve the water-resistant adhesiveness of the polarizing film. Conventionally, as a method of providing an easy-adhesive layer on a polarizer, various resins having a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a silicone type, a polyamide skeleton, a polyimide skeleton, a polyvinyl alcohol skeleton, etc. In consideration of handleability, it was common to apply an easy-adhesive composition containing a low boiling point organic solvent such as isopropanol or water as a diluent to the polarizer. However, with the conventional method, it is difficult to control the drying timing of the low boiling point organic solvent or water to be blended as a diluent, and if the timing cannot be optimized, the smoothness of the coated surface deteriorates, or the polarizer and coating are performed. The coatability of the easy-adhesion composition may deteriorate due to the 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), either 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 a monomer thereof. Both are blended in the easy-adhesion composition. As a result, it is possible to achieve both improvement in water resistance of the polarizing film and improvement in coatability when the easy-adhesion composition is applied to the adhesive layer forming surface side of the polarizer.

In the easy-adhesion composition, the boron-containing compound described in the above formula (1) can react with a functional group such as a hydroxyl group contained in a polarizer. This makes it possible to improve the adhesiveness between the polarizer and the adhesive layer, and as a result, has the effect of improving the water resistance of the polarizing film. Here, when the water content of the polarizer is low, specifically, for example, when the moisture content of the polarizer is 15% by weight or less, the boron-containing compound and the functional group contained in the polarizer cannot sufficiently react with each other. The effect may not be sufficient. However, even when the water content of the polarizer is low, by blending water in the easy-adhesion composition, the reactivity of the boron-containing compound with the functional group contained in the polarizer is enhanced, and thereby adhesion 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 resistance of the polarizing film is improved, and the coatability when the easy-adhesion composition is applied to the adhesive layer forming surface side of the polarizer is improved. Can be compatible with each other.

In the method for producing a polarizing film according to the present invention, when the coating step is a step of coating the easy-adhesion composition using a post-metric coating method, the polarizing film is polarized while improving the water-resistant adhesiveness of the polarizing film. It is possible to particularly improve the coatability when the easy-adhesive composition is applied to the adhesive layer forming surface side of the child. In the present invention, the "post-measurement coating method" means a method of applying an external force to the liquid film to remove excess liquid and obtain a predetermined coating film thickness. Specific examples of the post-weighing coating method include a gravure roll coating method, a forward roll coating method, an air knife coating method, and a rod / bar coating method. In the present invention, when the coating step is a step of coating the easy-adhesion composition using the post-measurement coating method, the reason why the effect is obtained can be presumed as follows.

In the post-measurement coating method, an external force is applied to the liquid film of the coated easy-adhesive composition, so that the easy-adhesive composition easily volatilizes. 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 non-uniform (this phenomenon is also called "horizontal dan"). ), Or the coating film develops adhesiveness due to the volatilization of the easy-adhesion composition, and the coating member provided in the coating device used in the post-measurement coating method, for example, the gravure roll coating method. For example, the coating film of the easy-adhesive composition develops adhesiveness to the gravure roll, and the peelability between the polarizer to be coated and the gravure roll deteriorates (this phenomenon is also called "sticking"). May occur. However, in the present invention, the easy-adhesion composition is selected from the group consisting of the boron-containing compound of the formula (1), an organic solvent having a boiling point of 85 ° C. or higher, and a monomer having a polymerizable group. At least one type is blended. Thereby, the boron-containing compound can improve the adhesiveness between the polarizer and the adhesive layer, reduce the volatilization of the easy-adhesion composition, and prevent the occurrence of lateral dan and sticking. As a result, in the method for producing a polarizing film according to the present invention, even when the coating step is a step of coating the easy-adhesion composition using a post-measurement coating method, the water-resistant adhesiveness of the polarizing film It is possible to particularly improve the coatability when the easy-adhesion composition is applied to the adhesive layer forming surface side of the polarizer.

In the polarizer with an easy-adhesion layer according to the present invention, the easy-adhesion layer is either a boron-containing compound, an organic solvent having a boiling point of 85 ° C. or higher, or a monomer having a polymerizable group having a boiling point of 85 ° C. or higher. Has one or both. Therefore, the polarizing film and the optical film provided with the polarizer with the easy-adhesion layer are excellent in improving the water adhesion resistance. 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 resistance 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 polarizing element via an adhesive layer, and an easy-adhesion composition is provided on the adhesive layer forming surface side of the polarizer. Has a coating process to coat. 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 easy-adhesion composition is described by the following general formula (1):

Compound represented by (where X is a functional group containing a reactive group, and R ¹ and R ² may independently have a hydrogen atom and a substituent, an aliphatic hydrocarbon group and an aryl group, respectively. , Or representing a heterocyclic group). The aliphatic hydrocarbon group includes a linear or branched alkyl group which may have a substituent having 1 to 20 carbon atoms, a cyclic alkyl group which may have a substituent having 3 to 20 carbon atoms, and carbon. Examples thereof include an alkenyl group having a number of 2 to 20, and examples of the aryl group include a phenyl group which may have a substituent having 6 to 20 carbon atoms, a naphthyl group which may have a substituent having 10 to 20 carbon atoms and the like. Examples of the heterocyclic group include a 5-membered ring or 6-membered ring group which may have a substituent and contains at least one heteroatom. These may be connected to each other to form a ring. In the general formula (1), R ¹ and R ² are preferably a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, and most preferably a hydrogen atom. The compound represented by the general formula (1) may be present in the easily adhesive layer between the polarizer and the adhesive layer in an unreacted state in the finally produced polarizing film. , Each functional group may exist in a reacted state. Further, in the present invention, the easy-adhesive layer may be formed by applying the easy-adhesive composition to the entire surface of the polarizer on the adhesive layer-forming surface side, and the easy-adhesive composition may be applied to at least a part of the surface. An easy-adhesion layer may be formed by coating.

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

で表される化合物（ただし、Ｙは有機基であり、Ｘ、Ｒ^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。 As a preferable specific example of the compound represented by the general formula (1), the following general formula (1')

Examples thereof include compounds represented by (where 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) can be mentioned.

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

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

If the content of the compound represented by the general formula (1) in the easy-adhesion composition is too small, the proportion of the compound represented by the general formula (1) present on the surface of the easy-adhesion layer decreases, and the easy-adhesion effect 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. It is more preferably 1% by weight or more.

In the present invention, the easy-adhesion composition is any 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, together with the boron-containing compound represented by the formula (1). Contains one or both.

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 (sulfolan) (boiling point 285 ° C), glycerol 1,2-carbonate (Boiling point 160 ° C / 0.8 mmHg), N, N-dimethylacetamide (boiling point 165 ° C.), dimethylsulfoxide (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, more preferably 100 ° C. or higher. The upper limit of the boiling point of the organic solvent is not particularly limited, but for example, about 300 ° C. can be exemplified.

In the present invention, when the easy-adhesion composition used contains the organic solvent, the content thereof is the easy-adhesion composition from the viewpoint of both 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, 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 the functional group contained in the polarizer is enhanced, and the adhesiveness between the polarizer and the adhesive layer is improved. From this point of view, it is preferable to further contain water, and in that case, the content is preferably 5 to 90% by weight, preferably 30 to 80% by weight, when the total amount of the easy-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 a radically polymerizable functional group of a carbon-carbon double bond such as a (meth) acryloyl group and a vinyl group. Examples of the monomer include acrylic morpholine (boiling point 158 ° C.), ethylene glycol diacrylate (n number of ethylene glycol moiety ≈ 9) (boiling point 197.3 ° C.), hydroxyethyl acrylamide (boiling point 124 ° C.), and N-vinyl. Examples thereof include pyrrolidone (boiling point 90 ° C.), acrylic acid (boiling point 141 ° C.), and allyl alcohol (boiling point 97 ° C.). 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 for example, about 300 ° C. can be exemplified.

In the present invention, when the easy-adhesion composition used contains the above-mentioned monomer, the content thereof is the easy-adhesion composition from the viewpoint of both improving the adhesiveness between the polarizer and the adhesive layer and improving the coatability. When the total amount of the substance 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 used contains the above-mentioned monomer, the reactivity of the boron-containing compound with the functional group contained in the polarizer is enhanced, and the adhesiveness between the polarizer and the adhesive layer is enhanced. From the viewpoint of improving the above, it is preferable to further contain water, and in that case, the content is preferably 5 to 90% by weight, preferably 30 to 80% by weight, when the total amount of the easy-adhesive composition is 100% by weight. More preferably.

In the present invention, the easy-adhesion composition may contain other additives such as a tackifier, an ultraviolet absorber, an antioxidant, a stabilizer such as a heat-resistant stabilizer, and the like.

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

If the content of the compound represented by the general formula (1) in the easy-adhesion layer is too small, the proportion 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 lower. 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, and 0.1. More preferably, it is by weight% or more.

<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. If the thickness of the adhesive layer is too thin, the cohesive force of the adhesive layer is insufficient and the peeling force is reduced, which is not preferable. If the thickness of the adhesive layer is too thick, peeling is likely to occur when a stress is applied to the cross section of the polarizing film, and peeling failure due to impact occurs, which is not preferable. The thickness of the adhesive layer is more preferably 0.1 to 2.5 μm, most preferably 0.5 to 1.5 μm.

<Adhesive composition>
The form of curing the adhesive composition can be roughly classified into thermosetting 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 if necessary, a curing agent. Is used in combination. As the resin constituting the thermosetting adhesive composition, a polyvinyl alcohol resin and an epoxy resin can be more preferably used. The active energy ray-curable adhesive composition can be roughly classified into electron beam curability, ultraviolet curability, and visible light curability as classified by active energy rays. Further, the form of curing can be classified into a radically polymerizable adhesive composition and a cationically polymerizable adhesive composition. In the present invention, active energy rays having a wavelength range of 10 nm to less than 380 nm are referred to as ultraviolet rays, and active energy rays having a wavelength range of 380 nm to 800 nm are referred to as visible light.

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

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

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。 Examples of the monofunctional radically polymerizable compound include the following general formula (2):

Compounds represented by (where R ³ is a hydrogen atom or a methyl group, and R ⁴ and R ⁵ are independently hydrogen atoms, alkyl groups, hydroxyalkyl groups, alkoxyalkyl groups or cyclic ether groups, respectively. R ⁴ and R ⁵ may form a cyclic heterocycle). The number of carbon atoms in the alkyl portion of the alkyl group, hydroxyalkyl group, and / or alkoxyalkyl group is not particularly limited, and examples thereof include 1 to 4 carbon atoms. Further, examples of the cyclic heterocycle that R ⁴ and R ⁵ may form include N-acryloyl morpholine and the like.

Specific examples of the compound represented by the general formula (2) include N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, and N-isopropyl ( N-alkyl group-containing (meth) acrylamide derivatives such as meta) acrylamide, N-butyl (meth) acrylamide, N-hexyl (meth) acrylamide; N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N -N-hydroxyalkyl group-containing (meth) acrylamide derivatives such as methylol-N-propane (meth) acrylamide; N-alkoxy group-containing (meth) acrylamide derivatives such as N-methoxymethylacrylamide and N-ethoxymethylacrylamide. Be done. Examples of the cyclic ether group-containing (meth) acrylamide derivative include a heterocycle-containing (meth) acrylamide derivative in which the nitrogen atom of the (meth) acrylamide group forms a heterocycle, and examples thereof include N-acrylloylmorpholine and N. -Acrylamide piperidine, N-methacryloyl piperidine, N-acrylamide and the like. Among these, N-hydroxyethylacrylamide and N-acryloylmorpholine can be preferably used from the viewpoints of excellent reactivity, high elastic modulus of cured product, and excellent adhesion to polarizers. it can.

From the viewpoint of improving adhesiveness and water resistance when the polarizer and the transparent protective film are adhered via the adhesive layer, the content of the compound represented by the general formula (2) in the adhesive composition is 0. It is preferably 01 to 80% by weight, more preferably 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 ( Meta) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, t-pentyl (meth) acrylate, 3-pentyl (meth) acrylate, 2,2-Dimethylbutyl (meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 4-methyl-2-propylpentyl ( Examples thereof include (meth) acrylic acid (1-20 carbon atoms) alkyl esters such as meta) 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. (Meta) acrylate, 2-norbornylmethyl (meth) acrylate, 5-norbornen-2-yl-methyl (meth) acrylate, 3-methyl-2-norbornylmethyl (meth) acrylate, dicyclopentenyl (meth) ) Polycyclic (meth) acrylates such as acrylicate, dicyclopentenyloxyethyl (meth) acrylicate, dicyclopentanyl (meth) acrylicate, etc .; 2-methoxyethyl (meth) acrylate, 2-ethoxy Ethyl (meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, alkylphenoxypolyethylene glycol (meth) acrylate, etc. An alkoxy group- or phenoxy group-containing (meth) acrylate; and the like. Among these, dicyclopentenyloxyethyl acrylicate and phenoxyethyl acrylate are preferable because they are excellent in adhesiveness 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-. Hydroxyalkyl (meth) acrylates such as hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate , [4- (Hydroxymethyl) cyclohexyl] methyl acrylate, cyclohexanedimethanol mono (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate and other hydroxyl group-containing (meth) acrylate; glycidyl (meth) acrylate, 4-Hydroxybutyl (meth) acrylate Epoxy group-containing (meth) acrylate such as glycidyl ether; 2,2,2-trifluoroethyl (meth) acrylate, 2,2,2-trifluoroethyl ethyl (meth) acrylate, tetra Halogen-containing (meth) acrylates such as fluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate, and 3-chloro-2-hydroxypropyl (meth) acrylate. ) Acrylate; Alkylaminoalkyl (meth) acrylate such as dimethylaminoethyl (meth) acrylate; 3-oxytenylmethyl (meth) acrylate, 3-methyl-oxetanylmethyl (meth) acrylate, 3-ethyl-oxetanylmethyl (meth) acrylate , 3-butyl-oxetanylmethyl (meth) acrylate, 3-hexyluoxetanylmethyl (meth) acrylate and other oxetane group-containing (meth) acrylate; tetrahydrofurfuryl (meth) acrylate, butyrolactone (meth) acrylate and other heterocycles. (Meta) acrylate having (meth) acrylate, neopentyl glycol (meth) acrylic acid adduct of hydroxypivalate, p-phenylphenol (meth) acrylate and the like can be mentioned. Among these, 2-hydroxy-3-phenoxypropyl acrylate is preferable because it has excellent adhesion to various protective films.

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

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

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 phosphate group-containing (meth) acrylate and the like When the above is contained, 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 with respect to the resin composition. If the content is too high, 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 with respect to the resin composition. If the content is too large, the optical durability of the polarizing film is lowered, which is not preferable. Examples of the phosphoric acid group-containing (meth) acrylate include 2- (meth) acryloyloxyethyl acid phosphate, and the content may be 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 lowered, which is not preferable.

Further, as the monofunctional radically polymerizable compound, a radically polymerizable compound having an active methylene group can be used. A radically polymerizable compound having an active methylene group is a compound having an active double bond group such as a (meth) acrylic group at the terminal or in the molecule and having an active methylene group. Examples of the active methylene group include an acetoacetyl group, an alkoxymalonyl group, a cyanoacetyl group and the like. It is preferable that the active methylene group is an acetoacetyl group. Specific examples of the radically polymerizable compound having an active methylene group include 2-acetoacetoxyethyl (meth) acrylate, 2-acetoacetoxypropyl (meth) acrylate, 2-acetacetoxy-1-methylethyl (meth) acrylate and the like. Acetacetoxyalkyl (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, and N- (2-acetoacetylaminoethyl) acrylamide. The radically polymerizable compound having an active methylene group is preferably acetoacetoxyalkyl (meth) acrylate.

Examples of the bifunctional or higher polyfunctional radical polymerizable compound include N, N'-methylenebis (meth) acrylamide, which is a polyfunctional (meth) acrylamide derivative, tripropylene glycol di (meth) acrylate, and tetraethylene glycol di. (Meta) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol diacrylate, 2-ethyl-2-butylpropanediol di (meth) ) Acrylate, bisphenol A di (meth) acrylate, bisphenol A ethylene oxide adduct di (meth) acrylate, bisphenol A propylene oxide adduct di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neopentyl Glycoldi (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, cyclic trimethylolpropaneformal (meth) acrylate, dioxane glycol di (meth) acrylate, trimethylolpropanetri (meth) acrylate, pentaerythritol tri ( (Meta) acrylic acid and polyhydric alcohols such as meta) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, EO-modified diglycerin tetra (meth) acrylate. , 9,9-Bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene. Specific examples include Aronix M-220 (manufactured by Toagosei), Light Acrylate 1,9ND-A (manufactured by Kyoeisha Chemical Co., Ltd.), Light Acrylate DGE-4A (manufactured by Kyoeisha Chemical Co., Ltd.), Light Acrylate DCP-A (manufactured by Kyoeisha Chemical Co., Ltd.). , SR-531 (manufactured by Sartomer), CD-536 (manufactured by Sartomer) and the like are preferable. Further, if necessary, various epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates, various (meth) acrylate-based monomers and the like can be mentioned. The polyfunctional (meth) acrylamide derivative is preferably contained in the adhesive composition because the polymerization rate is high and the productivity is excellent, and the crosslinkability when the adhesive composition is a cured product is excellent.

For the radically polymerizable compound, a monofunctional radically polymerizable compound and a polyfunctional radically polymerizable compound should be used in combination from the viewpoint of achieving both adhesiveness to a polarizer and various transparent protective films and optical durability in a harsh environment. Is preferable. Since the monofunctional radical polymerizable compound has a relatively low liquid viscosity, the liquid viscosity of the resin composition can be lowered by containing it in the resin composition. In addition, monofunctional radically polymerizable compounds often have functional groups that express various functions, and by containing them in the resin composition, various functions are exhibited in the resin composition and / or the cured product of the resin composition. Can be made to. The polyfunctional radical 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 parts by weight to 1000 parts by weight with respect to 100 parts by weight of the monofunctional radical-polymerizable compound. Is preferable.

The radically polymerizable adhesive composition does not need to contain a photopolymerization initiator when an electron beam or the like is used for the active energy ray, but is adhered when ultraviolet rays or visible light are used for the active energy ray. The agent composition preferably contains a photopolymerization initiator.

When a radically polymerizable compound is used, the photopolymerization initiator is appropriately selected by the active energy ray. When curing by ultraviolet rays or visible light, a photopolymerization initiator that cleaves ultraviolet rays 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). Aromatic ketone compounds such as -propyl) ketone, α-hydroxy-α, α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, α-hydroxycyclohexylphenylketone; methoxyacetophenone, 2,2-dimethoxy- Acetphenone compounds such as 2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1- [4- (methylthio) -phenyl] -2-morpholinopropane-1; benzophenone methyl ether, Benzophenone-BR> tower G-tel compounds such as benzoine ethyl ether, benzoin isopropyl ether, benzoine butyl ether, and anisoine methyl ether; aromatic ketal compounds such as benzyl dimethyl ketal; 2-naphthalene sulfonyl chloride, etc. Aromatic sulfonyl chloride compounds; photoactive oxime compounds such as 1-phenone-1,1-propanedione-2- (o-ethoxycarbonyl) oxime; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2, Thioxanthone compounds such as 4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone; benzophenone; ketone halide; acylphosphinoxide; acyl Examples include phosphonate.

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

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. Is preferable. A 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。 The photopolymerization initiator is a compound represented by the following general formula (3);

(In the formula, R ⁶ and R ⁷ indicate -H, -CH ₂ CH ₃ , -iPr or Cl, and R ⁶ and R ⁷ may be the same or different), or the general formula (in the formula) may be used alone. It is preferable to use the compound represented by 3) in combination with a photopolymerization initiator having high sensitivity to light of 380 nm or more, which will be described later. When the compound represented by the general formula (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, preferably 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.

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

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

（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 the 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 indicate -H, -CH ₃ , -CH ₂ CH ₃ , -iPr or Cl, and R ⁸ , R ⁹ and R ¹⁰ may be the same or different). It is preferable to use it. As the compound represented by the general formula (4), 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one (trade name: IRGACURE907 manufacturer: BASF), which is also 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.

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

In the present invention, examples of the radical polymerization initiator having a hydrogen abstraction action include a thioxanthone-based radical polymerization initiator and a benzophenone-based radical polymerization initiator. The radical polymerization initiator is preferably a thioxanthone-based radical polymerization initiator. Examples of the thioxanthone-based radical polymerization initiator include compounds represented by the above general formula (3). Specific examples of the compound represented by the general formula (3) include thioxanthone, dimethylthioxanthone, diethylthioxanthone, isopropylthioxanthone, chlorothioxanthone and the like. 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.

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

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

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

In the present invention, the compound described in the general formula (1), preferably the compound described in the general formula (1'), and more preferably the compound described in 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 adhesiveness to the polarizer or the transparent protective film may be improved, which is preferable. In the adhesive composition, from the viewpoint of improving the adhesiveness and water resistance between the polarizer and the cured product layer, particularly the adhesiveness and water resistance when the polarizer and the transparent protective film are adhered via the adhesive layer. The content of the compound according to 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 preferable.

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

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

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

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

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

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

The adhesive composition may contain a photoacid generator. When the adhesive composition contains a photoacid generator, the water resistance and durability of the adhesive layer can be dramatically improved as compared with the case where the photoacid generator is not contained. The photoacid generator can be represented by the following general formula (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 an arbitrary onium cation. X ⁻ is PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , SbCl ₆ ⁻ , BiCl ₅ ⁻ , SnCl ₆ ⁻ , ClO ₄ ⁻ , dithiocarbamate. Represents a counter anion selected from the group consisting of anions and SCN ⁻ ).

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, the nucleophilic reaction does not easily occur in the cation coexisting in the molecule or various materials used in combination. As a result, the photoacid generator itself represented by the general formula (5) itself. And it is possible to improve the stability of the composition using it over time. The non-nucleophilic anion referred to here refers to an anion having a low ability to cause a nucleophilic reaction. Examples of such anions include PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , SbCl ₆ ⁻ , BiCl _5- ⁻ , SnCl ₆ ⁻ , ClO ₄ ⁻ , dithiocarbamate anion, SCN ^{− and the} like.

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

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

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

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

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

Examples of the compound having a nitrobenzyl carbamate group and an alcoholoxybenzyl carbamate group include bis {{(2-nitrobenzyl) oxy} carbonyl} diaminodiphenylmethane, 2,4-di {(2-nitrobenzyl) oxy} toluylene, and the like. 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.

Other photobase generators include WPBG-018 (trade name: 9-anthrylmethyl N, N'-diethylcarbamate) and WPBG-027 (trade name: (E) -1- [3- (2-hydroxyphenyl) -2-). Propenoyl] piperidine), WPBG-082 (trade name: guanidinium2- (3-benzoylphenyl) proposal), WPBG-140 (trade name: 1- (anthraquinone-2-yl) ethyyl base, etc.) You can also do it.

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

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

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

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

The blending amount of the compound containing either the alkoxy group or the epoxy group is usually 30% by weight or less with respect to the total amount of the adhesive composition, and if the content of the compound in the composition is too large, the adhesiveness becomes poor. It may decrease 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 of the compound, and more preferably 5% by weight or more.

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

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

Preferred are 3-methacryloxypropyltrimethoxysilane and 3-acryloxypropyltrimethoxysilane.

As a specific example of a silane coupling agent having no active energy ray curability, 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 of ketimine-type silanes such as 1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propaneamine can be mentioned.

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

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

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

When the adhesive composition used in the present invention contains a compound having a vinyl ether group, it is preferable because the adhesive water resistance between the 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. To. In order to further enhance the adhesive water resistance between the polarizer and the adhesive layer, the compound is preferably a radically polymerizable compound having a vinyl ether group. The content of the compound is preferably 0.1 to 19% by weight based on the total amount of the adhesive composition.

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

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, 2,6-dimethylheptane-. Β-Diketones such as 3,5-dione; acetoacetate esters such as methyl acetoacetate, ethyl acetoacetate, isopropyl acetoacetate, tert-butyl acetate; ethyl propionyl acetate, ethyl propionyl acetate, isopropyl propionyl acetate, propionyl acetate Propionyl acetates such as tert-butyl; isobutyryl acetates such as ethyl isobutyryl acetate, ethyl isobutyryl acetate, isopropyl isobutyryl acetate, tert-butyl isobutyryl acetate; malonic acid esters such as methyl malate and ethyl malonate; etc. Can be mentioned. Among them, suitable compounds include acetylacetone and acetoacetic ester. The compounds that cause such keto-enol tautomerism may be used alone or in combination of two or more.

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

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

The cyclic molecule is not particularly limited as long as it is a molecule in which a linear molecule is 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 this specification, "cyclic" of "cyclic molecule" means substantially "cyclic". That is, the cyclic molecule does not have to be completely ring-closed as long as it 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. Be done. Among them, 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 polyrotaxane or in an adhesive.

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

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

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

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

In the present invention, a cationically polymerizable adhesive composition may be used for forming the adhesive layer. The cationically polymerizable compound used in the cationically polymerizable adhesive composition includes a monofunctional cationically polymerizable compound having one cationically polymerizable functional group in the molecule and two or more cationically polymerizable functional groups in the molecule. It is classified as a polyfunctional cationically polymerizable compound having. Since the monofunctional cationically polymerizable compound has a relatively low liquid viscosity, the liquid viscosity of the resin composition can be lowered by including it in the resin composition. In addition, monofunctional cationically polymerizable compounds often have functional groups that express various functions, and by containing them in the resin composition, various functions are exhibited in the resin composition and / or the cured product of the resin composition. Can be made to. The polyfunctional cationically polymerizable compound is preferably contained in the resin composition because the cured product of the resin composition can be three-dimensionally crosslinked. The ratio of the monofunctional cationically polymerizable compound to the polyfunctional cationically polymerizable compound is such that the polyfunctional cationically polymerizable compound is mixed in the range of 10 parts by weight to 1000 parts by weight with respect to 100 parts by weight of the monofunctional cationically polymerizable compound. Is preferable. Examples of the cationically polymerizable functional group include an epoxy group, an oxetanyl group, and a vinyl ether group. Examples of the compound having an epoxy group include an aliphatic epoxy compound, an alicyclic epoxy compound, and an aromatic epoxy compound. The cationically polymerizable adhesive composition of the present invention is excellent in curability and adhesiveness. It is particularly preferable to contain an alicyclic epoxy compound. Examples of the alicyclic epoxy compound include caprolactone-modified products and trimethylcaprolactone-modified products of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate. , Valerolactone modified products, and the like, specifically, seroxide 2021, seroxide 2021A, seroxide 2021P, seroxide 2081, seroxide 2083, seroxide 2085 (all manufactured by Daicel Chemical Industries, Ltd.), silacure UVR-6105, silacure UVR- 6107, Cyracure 30, R-6110 (all manufactured by Dow Chemical Japan Co., Ltd.) and the like can be mentioned. A compound having an oxetanyl group is preferably contained because it has the effect of improving the curability of the cationically polymerizable adhesive composition of the present invention and lowering the liquid viscosity of the composition. Compounds having an oxetane group include 3-ethyl-3-hydroxymethyloxetane, 1,4-bis [(3-ethyl-3-oxetanyl) methoxymethyl] benzene, 3-ethyl-3- (phenoxymethyl) oxetane, and the like. Di [(3-ethyl-3-oxetanyl) methyl] ether, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, phenol novolac oxetane, etc. are mentioned, and Aron oxetane OXT-101 and Aron oxetane OXT-121 , Aron Oxetane OXT-221, Aron Oxetane OXT-221, Aron Oxetane OXT-212 (all manufactured by Toa Synthetic Co., Ltd.) and the like are commercially available. A compound having a vinyl ether group is preferably contained because it has the effect of improving the curability of the cationically polymerizable adhesive composition of the present invention and lowering the liquid viscosity of the composition. Examples of compounds having a vinyl ether group include 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol vinyl ether, triethylene glycol divinyl ether, cyclohexanedimethanol divinyl ether, cyclohexanedimethanol monovinyl ether, and 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 at least one compound selected from the above-described curable component having an epoxy group, a compound having an oxetanyl group, and a compound having a vinyl ether group, all of which are cationically polymerized. Since it is cured by, a photocationic polymerization initiator is blended. This photocationic polymerization initiator generates a cationic species or Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, and initiates a polymerization reaction of an epoxy group or an oxetanyl group. As the photocationic polymerization initiator, a photoacid generator and a photobase generator can be used, and the photoacid generator described later is preferably used. When the adhesive composition used in the present invention is used with visible light curability, it is particularly preferable to use a photocationic polymerization initiator having high sensitivity to light of 380 nm or more, but the photocationic polymerization initiator is In general, since it is a compound that exhibits maximum absorption in a wavelength region near 300 nm or shorter, it is possible to add a light sensitizer that exhibits maximum absorption in light in a longer wavelength region, specifically, a wavelength longer than 380 nm. , Sensitive to light of wavelengths in the vicinity of this, can promote the generation of cation species or acids from the photocationic polymerization initiator. Examples of the photosensitizer include anthracene compounds, pyrene compounds, carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, photoreducing dyes and the like. Two or more types may be mixed and used. In particular, the anthracene compound is preferable because it has an excellent photosensitizing effect, and specific examples thereof include anthracene UVS-1331 and anthracene UVS-1221 (manufactured by Kawasaki Kasei Chemicals, Inc.). The content of the photosensitizer is preferably 0.1% by weight to 5% by weight, more preferably 0.5% by weight to 3% by weight.

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

The thin polarizing element generally has a low water content, and specifically, the water content is often 15% by weight or less. While such a thin polarizing element having a low water content has the above-mentioned effect, it has low reactivity with the boron-containing compound contained in the easy-adhesion composition used in the present invention, and the polarizer and the adhesive layer are bonded to each other. The effect of improving adhesiveness may not be sufficient. Therefore, in the method for producing a polarizing film according to the present invention, when a polarizing element having a water content of 15% by weight or less is used, the easy-adhesion 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.

As the polarizer, one using a polyvinyl alcohol-based resin is used. As the polarizer, for example, a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, an ethylene / vinyl acetate copolymer system partially saponified film, and a bicolor property of iodine or a bicolor dye are used. Examples thereof include a uniaxially stretched film by adsorbing a substance, a polyene-based oriented film such as a dehydrated product of polyvinyl alcohol and a dehydrogenated product of polyvinyl chloride. Among these, a polarizer made of a polyvinyl alcohol-based film and a dichroic substance such as iodine is preferable.

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

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

As a thin polarizer, typically
Japanese Patent No. 4751486,
Japanese Patent No. 4751481
Patent No. 4815544,
Japanese Patent No. 5048120,
International Publication No. 2014/07759 Pamphlet,
International Publication No. 2014/077636 Pamphlet,
And the like, or the thin polarizing element obtained from the manufacturing method described in these.

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

<Transparent protective film>
The transparent protective film preferably has excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropic property, and the like. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, and styrene such as polystyrene and acrylonitrile-styrene copolymer (AS resin). Examples include based polymers and polycarbonate polymers. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamides, imide polymers, and sulfone polymers. , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, allylate polymer, polyoxymethylene polymer, epoxy polymer, or the above. Polymer blends and the like are also examples of polymers that form the transparent protective film. The transparent protective film may contain one or more of any suitable additives. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, an antioxidant, a flame retardant, a nucleating agent, an antistatic agent, a pigment, a coloring agent and the like. The content of the thermoplastic resin in the transparent protective film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, still more preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. .. When the content of the thermoplastic resin in the transparent protective film is 50% by weight or less, the high transparency inherent in the thermoplastic resin may not be sufficiently exhibited.

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

Further, in the present invention, the moisture permeability of the transparent protective film used is preferably 150 g / m ² / 24h or less. According to such a configuration, 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, it is possible to suppress curl and dimensional change of the polarizing film caused by the storage environment.

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

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

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

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

On the other hand, as the transparent protective film, a retardation plate having a front retardation of 40 nm or more and / or a thickness direction retardation of 80 nm or more can be used. The front phase difference is usually controlled in the range of 40 to 200 nm, and the thickness direction phase difference is usually controlled in the range of 80 to 300 nm. 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 formed by uniaxially or biaxially stretching a polymer material, an alignment film of a liquid crystal polymer, and a film supporting an alignment layer of a liquid crystal polymer. The thickness of the retardation plate is not particularly limited, but is generally about 20 to 150 μm. Examples of the polymer material include polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, polysulfone, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, and the like. Polyphenylene sulphide, polyphenylene oxide, polyallyl sulfone, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose resin, cyclic polyolefin resin (norbornene resin), or these binary and ternary various copolymers and grafts Examples include polymers and blends. These polymer materials become oriented substances (stretched films) by stretching or the like.

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

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

The retardation plate has the relationship of nx = ny> nz, nx> ny> nz, nx> ny = nz, nz> nz> ny, nz = nz> ny, nz> nz> ny, nz> nz = ny. Those that are satisfied are selected and used according to various uses. 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, as a retardation plate satisfying nx> ny> nz, a retardation plate satisfying 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 is used. Is preferable. For example, in a retardation plate (positive A plate) satisfying nx> ny = nz, it is preferable to use a retardation plate satisfying a front retardation of 100 to 200 nm. For example, in a retardation plate (negative A plate) satisfying nz = nx> ny, it is preferable to use a retardation plate satisfying a front retardation of 100 to 200 nm. For example, in 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 and satisfying ~ 0.7. Further, as described above, for example, those satisfying nx = ny> nz, nz> nx> ny, or nz> nx = ny can be used.

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

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

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

Hereinafter, each step in the method for producing a polarizing film according to the present invention will be described.

The method for producing a polarizing film according to 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 polarizing element via an adhesive layer, and the adhesive layer is formed on the polarizing element. It has a coating step of coating the easy-adhesive composition on the surface side.

The polarizer and the transparent protective film may be surface-modified before the coating process. In particular, it is preferable to perform a surface modification treatment on the surface of the polarizer. Examples of the surface modification treatment include corona treatment, plasma treatment, excimer treatment, frame treatment, and the like, 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 substances on the surface and reduces the unevenness of the surface, so that a polarizing film having excellent appearance characteristics can be produced.

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

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 the occurrence of appearance defects of the finally obtained polarizing film, it is preferable that the pattern formed on the surface of the gravure roll is a honeycomb mesh pattern. If the honeycomb mesh pattern, it in order to enhance the surface accuracy of the coated surface after the easy-adhesion composition coated, cell volume is preferably from 1 to 5 cm ³ / ^{m 2,} a 2-3 cm ³ / ^{m 2} Is preferable. Similarly, in order to improve the surface accuracy of the coated surface after coating the easy-adhesive composition, the number of cell lines per 1 inch of 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 easy-adhesion composition>
In the method for producing a polarizing film according to the present invention, a polarizing element with an easy-adhesive layer may be formed by applying an easy-adhesive composition to the adhesive layer-forming surface side of the polarizing element. After the coating step, a polarizing step with an easy-adhesive layer may be formed by providing a drying step if necessary. As the drying step, steps known to those skilled in the art, for example, an air-drying step, a heating step, and a hot-air air-drying step can be used.

The method for producing a polarizing film according to the present invention is to form a polarizer with an easy-adhesive layer via a coating step of the easy-adhesive composition and, if necessary, a drying step of the easy-adhesive composition, and then attach the easy-adhesive layer. An adhesive composition coating step of applying an adhesive composition to at least one surface of an easily adhesive layer forming surface of a polarizer and a transparent protective film, and a bonding step of adhering the polarizer and the transparent protective film. And, the polarizer and the transparent protective film are adhered to each other through an adhesive layer obtained by irradiating an active energy ray from the side of the polarizer or the surface of the transparent protective film to cure the adhesive composition. Includes steps.

<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. For example, a reverse coater, a gravure coater (direct, reverse or offset), a bar reverse coater, a roll coater, or a die coater. , Bar coater, rod coater, etc.

<Lasting process>
The polarizer and the transparent protective film are bonded to each other via the adhesive composition coated as described above. The polarizer and the transparent protective film can be bonded by a roll laminator or the like.

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

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

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

In the method for producing a polarizing film according to the present invention, as the active energy ray, one containing visible light having a wavelength range of 380 nm to 450 nm, particularly an active energy ray having the largest irradiation amount of visible light having a wavelength range of 380 nm to 450 nm is used. Is preferable. When using ultraviolet rays and visible light, and when using a transparent protective film with ultraviolet absorbing ability (ultraviolet opaque transparent protective film), it is shorter than 380 nm because it absorbs light with a wavelength shorter than about 380 nm. Light of wavelength does not reach the adhesive composition and does not contribute to its polymerization reaction. Further, the light having a wavelength shorter than 380 nm absorbed by the transparent protective film is converted into heat, and the transparent protective film itself generates heat, which causes defects such as curl and wrinkles of the polarizing film. Therefore, when ultraviolet rays and visible rays are adopted in the present invention, it is preferable to use a device that does not emit light having a wavelength shorter than 380 nm as an active energy ray generator, and more specifically, integration in a wavelength range of 380 to 440 nm. The ratio of the illuminance to the integrated illuminance in the wavelength range of 250 to 370 nm is preferably 100: 0 to 100: 50, and more preferably 100: 0 to 100:40. In the method for producing a polarizing film according to the present invention, gallium-filled metal halide lamps and LED light sources that emit light in a wavelength range of 380 to 440 nm are preferable as active energy rays. Alternatively, with ultraviolet rays such as low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultra-high pressure mercury lamp, incandescent lamp, xenon lamp, halogen lamp, carbon arc lamp, metal halide lamp, fluorescent lamp, tungsten lamp, gallium lamp, excima laser or sunlight. A light source containing visible light can be used, and a bandpass filter can be used to block ultraviolet rays having a wavelength shorter than 380 nm. In order to prevent curling of the polarizing film while improving the adhesive performance of the adhesive layer between the polarizer and the transparent protective film, a gallium-filled metal halide lamp can be used and light having a wavelength shorter than 380 nm can be blocked. It is preferable to use an active energy ray obtained through a bandpass filter or an active energy ray having a wavelength of 405 nm obtained by using an LED light source.

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

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 of less than 5% at a wavelength of 365 nm. Here, the adhesive composition used in the present invention contains the above-mentioned photopolymerization initiator of the general formula (3), thereby irradiating ultraviolet rays through a transparent protective film having UV absorbing 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 a transparent protective film having a UV absorbing ability is laminated on both sides of the polarizing element. However, as a matter of course, the adhesive layer can be cured even in a polarizing film in which a transparent protective film having no UV absorbing ability is laminated. The transparent protective film having a UV absorbing ability means a transparent protective film having a transmittance of less than 10% for light at 380 nm.

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

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

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

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

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

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

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

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

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

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

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

An appropriate liquid crystal display device such as a liquid crystal display device in which a polarizing film or an optical film is arranged on one side or both sides of the liquid crystal cell, or a lighting system using a backlight or a reflector can be formed. In that case, the polarizing film or optical film according to the present invention can be arranged on one side or both sides of the liquid crystal cell. When polarizing films or optical films are provided on both sides, they may be the same or different. Further, when forming the liquid crystal display device, for example, an appropriate component such as a diffuser plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffuser plate, and a backlight is placed in an appropriate position in one 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 stretched laminate was formed by aerial auxiliary stretching at a stretching temperature of 130 ° C. on a laminate in which a 9 μm-thick PVA layer was formed on an amorphous PET substrate, and then the stretched laminate was dyed to form a colored laminate. The colored laminate is further stretched in boric acid at a stretching temperature of 65 ° C. to include a 5 μm-thick PVA layer integrally stretched with an amorphous PET substrate so that the total stretching ratio is 5.94 times. An optical film laminate was produced. The PVA molecules in the PVA layer formed on the amorphous PET substrate by such two-step stretching are highly oriented, and the iodine adsorbed by dyeing is highly oriented in one direction as a polyiodine ion complex. An optical film laminate containing a PVA layer having a thickness of 5 μm, which constitutes a thin polarizing element, was obtained. The moisture content of the thin polarizer (PVA layer) was 10% by weight.

<Transparent protective film A>
A twin-screw kneader containing 100 parts by weight of the imidized MS resin and 0.62 parts by weight of a triazine-based ultraviolet absorber (trade name: T-712) described in Production Example 1 of JP-A-2010-284840. The mixture was mixed at 220 ° C. to prepare resin pellets. The obtained resin pellets were dried at 100.5 kPa at 100 ° C. for 12 hours and extruded from a T-die at a die temperature of 270 ° C. using a single-screw extruder to form a film (thickness 160 μm). Further, the film is stretched in an atmosphere of 150 ° C. in the transport direction (thickness 80 μm), then coated with an easy-adhesive containing an aqueous urethane resin, and then stretched in an atmosphere of 150 ° C. in a direction orthogonal to the film transport direction. Then, 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 (manufactured by Fuji Film Co., Ltd .: Fujitac TG60UL) was used.

<Active energy ray>
Visible light (gallium-filled metal halide lamp) as active energy rays Irradiator: Fusion UV Systems, Inc. Light HAMMER10 valve: V valve Peak illuminance: 1600 mW / cm ² , integrated irradiation amount 1000 / mJ / cm2 (wavelength 380 to 440 nm )It was used. The illuminance of visible light was measured using a Solar-Check system manufactured by Solarll.

(Adjustment of easy-adhesion composition)
The easy-adhesion 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-acrylamide phenylboronic acid; manufactured by Genuine Chemical Co., Ltd. (2) Leveling agent, trade name "Orfin EXP.4200", manufactured by Nissin Chemical Industry Co., Ltd. (3) Boiling point of 85 ° C or higher, polymerizable Monomer having a group Acryloylmorpholin (boiling point 158 ° C.); trade name "ACMO", Kojinsha ethylene glycol diacrylate (n number of ethylene glycol moiety ≈ 9) (boiling point 197.3 ° C.); trade name "light" Acrylate 9EG-A ”, hydroxyethyl acrylamide manufactured by Kyoeisha Chemical Co., Ltd. (boiling point 124 ° C); trade name“ HEAA ”, manufactured by Kojin Co., Ltd. (4) Organic solvent diacetone alcohol (boiling point 166 ° C) having a boiling point of 85 ° C or higher.
Ethylene glycol (boiling point 197.3 ° C)
(5) Diluent water (boiling point 100 ° C)
Isopropyl alcohol (boiling point 82.4 ° C)

(Coating process of easy-adhesive composition)
Using a 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 containing the PVA layer having a thickness of 5 μm of the polarizer, and 25 A polarizer with an easy-adhesion layer was prepared by air-drying at ° C. for 1 minute. Table 1 shows the thickness before drying (Wet thickness) and the thickness after drying (Dry thickness) at the time of coating the easy-adhesive composition in the coating steps of each Example and Comparative Example.

(Evaluation of coatability)
In the coating process of each Example and Comparative Example, the case where the horizontal dan did not occur at the time of coating was evaluated as ◯, and the case where it occurred was evaluated as ×. In addition, the case where the gravure roll and the polarizer did not stick was evaluated as 〇, and the case where the gravure roll and the polarizer did stick was evaluated as ×. The results are shown in Table 1.

(Adhesive composition adjustment)
When the total amount of the composition is 100% by weight, 43.0% by weight of acrylic morpholine, 43.0% by weight of 1,9-nonandiol diacrylate (trade name "Light Acrylate 1.9ND-A", manufactured by Kyoeisha Chemical Co., Ltd.) %, Acrylic oligomer obtained by polymerizing (meth) acrylic monomer (trade name "ARUFON UG4010", manufactured by Toa Synthetic Co., Ltd.) 9.7% by weight, diethylthioxanthone as a photoinitiator (general formula (3). Compound, trade name "KAYACURE DETX-S", manufactured by Nippon Kayakusha) 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 (compound according to general formula (4), trade name "IRGACURE907", manufactured by BASF) and stirring at 50 ° C. for 1 hour. The agent composition was adjusted.

(Preparation of polarizing film)
Adhesion of the transparent protective film A to the bonding surface side using an MCD coater (manufactured by Fuji Kikai Co., Ltd.) (cell shape: honeycomb, number of gravure rolls: 1000 lines / inch, rotation speed 140% / line speed). The agent composition was applied to a thickness of 0.7 μm to form an uncured adhesive layer. Next, using a roll machine, the polarizing element with an easily adhesive layer was bonded to the transparent protective film from the surface side of the easily adhesive layer. Then, the visible light is irradiated from the bonded transparent protective film side with an active energy ray irradiator to adhere the polarizing element and the transparent protective film, and then hot air dried at 70 ° C. for 3 minutes to obtain the polarizing element. By peeling off the amorphous PET base material laminated on the other side, a polarizing film having a transparent protective film on one side of the polarizer was obtained. The bonding line speed was 25 m / min. A transparent protective film B was used for evaluation of water resistance and adhesiveness, and a polarizing film was produced by the same method as described above.

(Water resistance evaluation (initial adhesive strength))
The obtained polarizing film was cut into a size of 200 mm in parallel with 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 in the 90-degree direction at a peeling speed of 300 mm / min with Tensilon to increase the peeling strength (N / 15 mm). It was measured. Further, the infrared absorption spectrum of the peeled surface after peeling was measured by the ATR method, and the peeling form was evaluated based on the following criteria. The results are shown in Table 1.
〇: When the transparent protective film breaks the material or when the polarizer breaks the material ×: When the transparent protective film and the adhesive interlayer peel off from each other, or when the polarizer and the adhesive interlayer peel off from each other.

(Evaluation of water resistance (cold water immersion peeling 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 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, and 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-degree direction with Tensilon, and the peeling strength was measured. The above evaluation was performed within 1 minute after removing the polarizing film from pure water. The results are shown in Table 1.

(Evaluation of water resistance (severe cold water immersion peeling 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 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, and 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-degree direction with Tensilon, and the peeling strength was measured. The above evaluation was performed within 1 minute after removing the polarizing film from pure water. The results are shown in Table 1.

Claims (13)

A method for manufacturing a polarizing film in which a transparent protective film is provided on at least one surface of a polarizing element via an adhesive layer.
It has a coating step of applying an easy-adhesion composition to the adhesive layer forming surface side of the polarizer.
The easy-adhesion composition has the following general formula (1):

Compound represented by (where X is a functional group containing a reactive group, and R ¹ and R ² may independently have a hydrogen atom and a substituent, an aliphatic hydrocarbon group and an aryl group, respectively. , Or a heterocyclic group) and 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 method for manufacturing a polarizing film. The compound represented by the general formula (1) is the following general formula (1').

The method for producing a polarizing film according to claim 1, wherein Y is an organic group, and X, R ¹ and R ² are the same as described above. The reactive groups of the compound represented by the general formula (1) are (meth) acrylamide group, α, β-unsaturated carbonyl group, vinyl group, vinyl ether group, epoxy group, oxetane group, amino group and aldehyde group. The method for producing a polarizing film according to claim 1 or 2, which 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 polarizing element is 15% by weight or less. The method for producing a polarizing film according to any one of claims 1 to 4, wherein the easy-adhesion 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 easy-adhesion composition using a post-metric 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 easy-adhesion layer in which an easy-adhesion layer is formed on at least one surface of the polarizer.
The easy-adhesion layer has the following general formula (1):

Compound represented by (where X is a functional group containing a reactive group, and R ¹ and R ² may independently have a hydrogen atom and a substituent, an aliphatic hydrocarbon group and an aryl group, respectively. , Or a heterocyclic group) and 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. Hydrocarbon with easy adhesive layer. The compound represented by the general formula (1) is the following general formula (1').

The polarizer with an easy-adhesion layer according to claim 8, wherein Y is an organic group, and X, R ¹ and R ² are the same as described above. The reactive groups of the compound represented by the general formula (1) are (meth) acrylamide group, α, β-unsaturated carbonyl group, vinyl group, vinyl ether group, epoxy group, oxetane group, amino group and aldehyde group. The polarizer with an easily adhesive layer according to claim 8 or 9, 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 via an adhesive layer on the easily adhesive layer forming surface of the polarizing element with an easy adhesive layer according to any one of claims 8 to 10. An optical film characterized in that at least one polarizing film according to claim 11 is laminated. An image display device according to claim 11, wherein the polarizing film according to claim 11 and / or the optical film according to claim 12 is used.