Adhesive optical member

The present invention relates to an adhesive type optical member in which an antistatic pressure-sensitive adhesive layer is provided on the optical member. The present invention is suitably used for an adhesive optical member using a plastic material that easily generates static electricity. In particular, it is useful as an adhesive optical member used in liquid crystal displays, touch panels, and the like.

In liquid crystal displays and touch panels, various optical films such as polarizing plates and wave plates are laminated via an adhesive layer in order to control and adjust the vibration direction and phase difference of light. These optical films are distributed in the form of a separator for the purpose of protecting the adhesive surface for the purpose of preventing scratches and stains, and a surface protective film for the purpose of preventing scratches and stains that occur during processing and transportation processes. There is.

In the step of laminating the optical films, the separator and the surface protective film used for the purpose of protecting the optical films are unnecessary, so that they are peeled off and removed from the optical films.

Since these optical films, adhesives, separators, and surface protective films are made of plastic materials, they have high electrical insulation and generate static electricity during friction and peeling. Therefore, static electricity is generated when the separator or the surface protective film is peeled off from the optical film. Static electricity is a major problem in the manufacturing process of liquid crystal displays and touch panels. Examples of defects caused by static electricity include dust adhering to the optical member, abnormal display due to disorder of liquid crystal orientation, and electrostatic destruction of peripheral circuit elements. Therefore, in order to prevent such a defect, various antistatic treatments are applied to the optical member.

For example, a method of forming a conductive layer of indium oxide / tin oxide on a polarizing plate by sputtering to perform an antistatic treatment is disclosed (see, for example, Patent Document 1). Further, a method of forming an antistatic layer made of an ultraviolet curable acrylic resin containing metal oxide particles on a polarizing plate is disclosed (see, for example, Patent Document 2).

However, in these methods, a new step for forming the antistatic layer on the optical member is required, and the increase in the number of steps lowers the productivity and raises the cost. Therefore, the polarizing plate provided with the antistatic layer has a problem that the cost is higher than that of the conventional polarizing plate not subjected to the antistatic treatment.

On the other hand, a polarizing member in which a light diffusing layer having an antistatic ability is formed by adding an antistatic agent to the light diffusing layer is also known (see, for example, Patent Document 3), but this light diffusing layer is a backlight. It is used to diffuse the light from the light, and is not universally used for optical members.<patcit num="1"><text>Japanese Patent Application Laid-Open No. 6-51121</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 2001-318230</text></patcit><patcit num="3"><text>Japanese Patent Application Laid-Open No. 2002-22960</text></patcit>

<p> In light of these circumstances, the present invention can easily and inexpensively prevent the optical member generated when the separator or the surface protective film is peeled off by imparting an antistatic ability to the highly versatile adhesive layer. Moreover, it is an object of the present invention to provide an adhesive type optical member capable of sufficiently maintaining the adhesive force of the adhesive layer.</p>

<p> As a result of diligent studies to solve the above problems, the present inventors have found that the above object can be achieved by using the pressure-sensitive adhesive composition shown below, and have completed the present invention.</p><p> That is, the pressure-sensitive adhesive optical member of the present invention is a pressure-sensitive optical member in which a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition is formed on one side or both sides of the optical member. It is characterized by containing a polymer having a glass transition temperature Tg of 0 ° C. or less as a base polymer. Here, the ionic liquid refers to a molten salt (ionic compound) that exhibits a liquid at room temperature (25 ° C).</p><p> According to the adhesive type optical member of the present invention, by imparting an antistatic function to the adhesive layer, it is possible to easily prevent the optical member from being charged without newly providing an antistatic layer, and it is inexpensive without reducing productivity. Can be manufactured. By using an ionic liquid as an antistatic agent, a pressure-sensitive adhesive composition having a high antistatic effect can be obtained without impairing the adhesive properties. The details of the reason why excellent antistatic properties can be obtained by using an ionic liquid are not clear, but since the ionic liquid is a liquid, molecular motion is easy, and molecular rearrangement is likely to occur due to the generation of electric charges. Therefore, even if the ionic liquid is contained in the pressure-sensitive adhesive, the charge neutralization mechanism by molecular rearrangement works, and it is considered that excellent antistatic ability can be obtained. Further, since the ionic liquid is liquid at room temperature, it can be easily added to and dispersed or dissolved in the pressure-sensitive adhesive as compared with a solid salt. Furthermore, since the ionic liquid has no vapor pressure (nonvolatile), it does not disappear over time and has the characteristic that antistatic properties can be continuously obtained.</p><p> In the above, it is preferable that the ionic liquid is at least one of a nitrogen-containing onium salt, a sulfur-containing onium salt, and a phosphorus-containing onium salt. In particular, it is preferable that the ionic liquid contains one or more cations represented by the following general formulas (A) to (D). An ionic liquid having these cations can provide an ionic liquid having further excellent antistatic ability.</p><p><chemistry num="1"><img file="JP5019552B2_D0001.tif" /></chemistry>[Ra in formula (A) represents a hydrocarbon group having 4 to 20 carbon atoms and may contain a heteroatom, and Rb and Rc are the same or different, hydrogen or a hydrocarbon group having 1 to 16 carbon atoms. And may contain a heteroatom. However, if the nitrogen atom contains a double bond, there is no Rc. ] [Rd in formula (B) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a heteroatom, and Re, Rf, and Rg are the same or different and have hydrogen or 1 to 16 carbon atoms. It represents a hydrocarbon group and may contain a heteroatom. ] [Rh in formula (C) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a heteroatom, and Ri, Rj, and Rk are the same or different and have hydrogen or 1 to 16 carbon atoms. It represents a hydrocarbon group and may contain a heteroatom. ] [Z in formula (D) represents a nitrogen, sulfur, or phosphorus atom, and Rl, Rm, Rn, and Ro represent hydrocarbon groups with 1 to 20 carbon atoms, which are the same or different, and are heteroatoms. It may be included. However, if Z is a sulfur atom, there is no Ro. ] Further, it is preferable that the polymer having a glass transition temperature Tg of 0 ° C. or less is an acrylic polymer containing at least one acrylate and / or methacrylate having an alkyl group having 1 to 14 carbon atoms as a main component. With these acrylic polymers, the balance of compatibility with the ionic liquid and the base polymer is improved, and the adhesive properties can be sufficiently maintained.</p><p> The adhesive type optical member of the present invention is particularly effective when the optical member includes a polarizing plate, a retardation plate, a brightness improving plate, or an antiglare sheet.</p>

The adhesive optical member of the present invention contains an ionic liquid and a polymer having a glass transition temperature Tg of 0 ° C. or less as a base polymer. An ionic liquid refers to a molten salt (ionic compound) that exhibits a liquid at room temperature (25 ° C).

As the ionic liquid, a nitrogen-containing onium salt, a sulfur-containing onium salt, or a phosphorus-containing onium salt is preferably used, and is represented by the following general formulas (A) to (D) for the reason that particularly excellent antistatic ability can be obtained. Those composed of an organic cation component and an anion component are preferably used.

<chemistry num="2"><img file="JP5019552B2_D0002.tif" /></chemistry>[Ra in formula (A) represents a hydrocarbon group having 4 to 20 carbon atoms and may contain a heteroatom, and Rb and Rc are the same or different, hydrogen or a hydrocarbon group having 1 to 16 carbon atoms. And may contain a heteroatom. However, if the nitrogen atom contains a double bond, there is no Rc. ] [Rd in formula (B) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a heteroatom, and Re, Rf, and Rg are the same or different and have hydrogen or 1 to 16 carbon atoms. It represents a hydrocarbon group and may contain a heteroatom. ] [Rh in formula (C) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a heteroatom, and Ri, Rj, and Rk are the same or different and have hydrogen or 1 to 16 carbon atoms. It represents a hydrocarbon group and may contain a heteroatom. ] [Z in formula (D) represents a nitrogen, sulfur, or phosphorus atom, and Rl, Rm, Rn, and Ro represent hydrocarbon groups with 1 to 20 carbon atoms, which are the same or different, and are heteroatoms. It may be included. However, if Z is a sulfur atom, there is no Ro. ] Examples of the cation represented by the formula (A) include a pyridinium cation, a piperidinium cation, a pyrrolidinium cation, a cation having a pyrroline skeleton, and a cation having a pyrrole skeleton. Specific examples include 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, 1-hexyl-3. -Methylpyridinium cation, 1-butyl-3,4-dimethylpyridinium cation, 1,1-dimethylpyrrolidinium cation, 1-ethyl-1-methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidinium cation , 2-Methyl-1-pyrrolinic cation, 1-ethyl-2-phenylindole cation, 1,2-dimethylindole cation, 1-ethylcarbazole cation.

Examples of the cation represented by the formula (B) include an imidazolium cation, a tetrahydropyrimidinium cation, and a dihydropyrimidinium cation. Specific examples include 1,3-dimethylimidazolium cation, 1,3-diethyl imidazolium cation, 1-ethyl-3-methyl imidazolium cation, 1-butyl-3-methyl imidazolium cation, 1-hexyl-. 3-Methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methylimidazolium cation, 1-tetradecyl-3-methylimidazolium cation , 1,2-Dimethyl-3-propylimidazolium cation, 1-ethyl-2,3-dimethylimidazolium cation, 1-butyl-2,3-dimethylimidazolium cation, 1-hexyl-2,3-dimethyl Imidazolium cation, 1,3-dimethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3-trimethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2, 3,4-Tetramethyl-1,4,5,6-Tetrahydropyrimidinium cation, 1,2,3,5-Tetramethyl-1,4,5,6-Tetrahydropyrimidinium cation, 1,3- Dimethyl-1,4-dihydropyrimidinium cation, 1,3-dimethyl-1,6-dihydropyrimidinium cation, 1,2,3-trimethyl-1,4-dihydropyrimidinium cation, 1,2, 3-trimethyl-1,6-dihydropyrimidinium cation, 1,2,3,4-tetramethyl-1,4-dihydropyrimidinium cation, 1,2,3,4-tetramethyl-1,6- Examples include dihydropyrimidinium cation.

Examples of the cation represented by the formula (C) include a pyrazolium cation and a pyrazolinium cation. Specific examples include 1-methylpyrazolium cation, 3-methylpyrazolium cation, 1-ethyl-2-methylpyrazolinium cation and the like.

Examples of the cation represented by the formula (D) include a tetraalkylammonium cation, a trialkylsulfonium cation, a tetraalkylphosphonium cation, and a cation in which a part of the above alkyl group is replaced with an alkenyl group, an alkoxyl group, or an epoxy group. Can be mentioned.

Specific examples include tetramethylammonium cation, tetraethylammonary cation, tetrabutylammonium cation, tetrahexylammonium cation, triethylmethylammonium cation, tributylethylammonary cation, trimethyldecylammonium cation, N, N-diethyl-N-methyl-N. -(2-Methyl) ammonium cation, glycidyltrimethylammonium cation, N, N-dimethyl-N, N-dipropylammonary cation, N, N-dimethyl-N, N-dihexylammonium cation, N, N-dipropyl- N, N-dihexylammonium cation, trimethylsulfonium cation, triethylsulfonium cation, tributylsulfonium cation, trihexylsulfonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, tetramethylphosphonium cation, tetraethylphosphonium cation, tetra Examples thereof include butylphosphonium cation, tetrahexylphosphonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation, trimethyldecylphosphonium cation, diallyldimethylammonium cation and the like.

Among them, triethylmethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyltrimethylammonium cation, N, N-dimethyl-N- Ethyl-N-propylammonium cation, N, N-dimethyl-N-ethyl-N-butylammonium cation, N, N-dimethyl-N-ethyl-N-pentylammonium cation, N, N-dimethyl-N-ethyl- N-hexyl ammonium cation, N, N-dimethyl-N-ethyl-N-heptyl ammonium cation, N, N-dimethyl-N-ethyl-N-nonyl ammonium cation, N, N-dimethyl-N-propyl-N- Butylammonium cation, N, N-dimethyl-N-propyl-N-pentylammonium cation, N, N-dimethyl-N-propyl-N-hexylammonium cation, N, N-dimethyl-N-propyl-N-heptylammonium Cations, N, N-dimethyl-N-butyl-N-hexyl ammonium cations, N, N-dimethyl-N-butyl-N-heptyl ammonium cations, N, N-dimethyl-N-pentyl-N-hexyl ammonium cations, Trimethylheptyl ammonium cation, N, N-diethyl-N-methyl-N-propylammonium cation, N, N-diethyl-N-methyl-N-pentylammonium cation, N, N-diethyl-N-methyl-N-heptyl Ammonium cation, N, N-diethyl-N-propyl-N-pentylammonary cation, triethylmethylammonium cation, triethylpropylammonium cation, triethylpentylammonium cation, triethylheptylammonium cation, N, N-dipropyl-N-methyl-N -Ethylammonium cation, N, N-dipropyl-N-methyl-N-pentylammonium cation, N,N-dipropyl-N-butyl-N-hexylammonary cation, N, N-dibutyl-N-methyl-N-pentylammonium cation, N, N-dibutyl-N-methyl-N-hexylammonary cation, trioctylmethylammonium Asymmetric tetraalkylammonium cations such as cations, N-methyl-N-ethyl-N-propyl-N-pentylammonium cations, trialkylsulfonium cations such as diethylmethylsulfonium cations, dibutylethylsulfonium cations, dimethyldecylsulfonium cations, triethyl Asymmetric tetraalkylphosphonium cations such as methylphosphonium cations, tributylethylphosphonium cations and trimethyldecylphosphonium cations are preferably used.

On the other hand, the anionic component is not particularly limited as long as it satisfies the condition of becoming an ionic liquid, and for example, Cl.^-, Br^-, I^-, AlCl₄^-, Al₂Cl₇^-, BF₄^-, PF₆^-, ClO₄^-, NO₃^-, CH₃COO^-, CF₃COO^-, CH₃SO₃^-, CF₃SO₃^-, (CF₃SO₂)₂N^-, (CF₃SO₂)₃C^-, AsF₆^-, SbF₆^-, NbF₆^-, TaF₆^-, F (HF)_n^-, (CN)₂N^-, C₄F₉SO₃^-, (C₂F₅SO₂)₂N^-, C₃F₇COO^-, (CF₃SO₂) (CF₃CO) N^-Etc. are used. Among them, the anionic component containing a fluorine atom is particularly preferably used because an ionic compound having a low melting point can be obtained.

Specific examples of the ionic liquid used in the present invention include 1-butylpyridinium tetrafluoroborate, 1-butylpyridinium hexafluorophosphate, and 1-butyl-, which are appropriately selected from the combination of the above cationic component and anionic component. 3-Methylpyridinium tetrafluoroborate, 1-butyl-3-methylpyridinium trifluoromethanesulfonate, 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide, 1-butyl-3-methylpyridinium bis (pentafluoroethanesulfonyl) ) Imide, 1-hexylpyridinium tetrafluoroborate, 2-methyl-1-pyrrolinte tetrafluoroborate, 1-ethyl-2-phenylindole tetrafluoroborate, 1,2-Dimethylindole tetrafluoroborate, 1-ethylcarbazole tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium tri Fluoroacetate, 1-ethyl-3-methylimidazolium heptafluorobutyrate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium perfluorobutanesulfonate, 1-ethyl-3-methyl Imidazolium disianamide, 1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-ethyl-3-methylimidazolium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-3-methylimidazolium tris (Trifluoromethanesulfonyl) imide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium trifluoroacetate, 1-butyl- 3-Methylimidazolium heptafluorobutyrate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium perfluorobutane sulfonate, 1-butyl-3-methylimidazolium bis (trifluoromethanesulfonyl) ) Imid, 1-hexyl-3-methylimidazolium bromide, 1-hexyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium tetrafluoroborate, 1-hexyl-3-methylimidazole Rium hexafluorophosphate, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate, 1-octyl-3-methylimidazolium tetrafluoroborate, 1-octyl-3-methylimidazolium hexafluorophosphate, 1-hexyl- 2,3-Dimethylimidazolium tetrafluoroborate, 1,2-Dimethyl-3-propylimidazolium bis (trifluoromethanesulfonyl) imide, 1-methylpyrazolium tetrafluoroborate, 3-methylpyrazolium tetrafluoroborate, tetrahexyl ammonium bis (trifluoromethanesulfonyl) imide, diallyldimethyl Ammonium tetrafluoroborate, diallyldimethylammonium trifluoromethanesulfonate, diallyldimethylammonium bis (trifluoromethanesulfonyl) imide, diallyldimethylammonium bis (pentafluoroethanesulfonyl) imide, N, N-diethyl-N-methyl-N- (2-) Methoxyethyl) ammonium tetrafluoroborate, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium trifluoromethanesulfonate, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium Bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium bis (pentafluoroethanesulfonyl) imide, glycidyltrimethylammonium trifluoromethanesulfonate, glycidyltrimethylammonium bis (trifluoromethane) Sulfonyl) imide, glycidyltrimethylammonium bis (pentafluoroethanesulfonyl) imide, 1-butylpyridinium (trifluoromethanesulfonyl) trifluoroacetamide, 1-butyl-3-methylpyridinium (trifluoromethanesulfonyl) trifluoroacetamide, 1-ethyl- 3-Methyl imidazolium (trifluoromethanesulfonyl) trifluoroacetamide, diallyldimethylammonium (trifluoromethanesulfonyl) trifluoroacetamide, glycidyltrimethylammonium (trifluoromethanesulfonyl) trifluoroacetamide, N, N-dimethyl-N-ethyl-N- Propylammonium bis (trifluoromethanesulfonyl) imide, N,N-dimethyl-N-ethyl-N-butylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N- Ethyl-N-hexyl ammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-heptyl ammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-nonyl Ammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N, N-dipropylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-butylammonium bis (trifluoromethanesulfonyl) Imide, N, N-dimethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-hexyl ammonium bis (trifluoromethanesulfonyl) imide, N, N- Dimethyl-N-propyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-butyl-N-hexyl ammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-butyl- N-Heptyl ammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-pentyl-N-hexyl ammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N, N-dihexyl ammonium bis (trifluoromethane) Sulfonyl) imide, trimethylheptyl ammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-propylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-pentyl Ammonium bis (trifluoromethanesulfonyl) imide, N,N-diethyl-N-methyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, triethylpropylammonium bis (trifluoromethanesulfonyl) imide ) Imide, triethylpentylammonium bis (trifluoromethanesulfonyl) imide, triethylheptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N-methyl-N-ethylammonium bis (trifluoromethanesulfonyl) imide, N, N -Dipropyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N-butyl-N-hexyl ammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N, N-dihexyl ammonium bis (trifluoromethanesulfonyl) imide, N, N-dibutyl-N-methyl-N-pentyl ammonium bis (trifluoromethanesulfonyl) imide, N, N-dibutyl-N-methyl-N-hexyl ammonium bis ( Examples thereof include trifluoromethanesulfonyl) imide, trioctylmethylammonium bis (trifluoromethanesulfonyl) imide, and N-methyl-N-ethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide.N-dipropyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N-butyl-N-hexyl ammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N , N-dihexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dibutyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dibutyl-N-methyl-N-hexylammonium bis Examples thereof include (trifluoromethanesulfonyl) imide, trioctylmethylammonium bis (trifluoromethanesulfonyl) imide, and N-methyl-N-ethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide.N-dipropyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N-butyl-N-hexyl ammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N , N-dihexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dibutyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dibutyl-N-methyl-N-hexylammonium bis Examples thereof include (trifluoromethanesulfonyl) imide, trioctylmethylammonium bis (trifluoromethanesulfonyl) imide, and N-methyl-N-ethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide.

As the ionic liquid as described above, a commercially available one may be used, but it can also be synthesized as described below. The method for synthesizing an ionic liquid is not particularly limited as long as the desired ionic liquid can be obtained, but in general, the literature "Ionic liquid-the forefront and future of development-" [CMC Publishing Co., Ltd. Issuance], a halide method, a hydroxide method, an acid ester method, a complex formation method, a neutralization method, and the like are used.

The following shows the synthesis method of the halide method, hydroxide method, acid ester method, complex formation method, and neutralization method using a nitrogen-containing onium salt as an example, but other sulfur-containing onium salts, phosphorus-containing onium salts, etc. The ionic liquid of the above can also be obtained by the same method.

The halide method is a method carried out by a reaction as shown in the following formulas (1) to (3). First, a halide is obtained by reacting a tertiary amine with an alkyl halide. (Reaction formula (1), chlorine, bromine, and iodine are used as halogens) Anionic structure of ionic liquid for the purpose of the obtained halide (A)^-) With an acid (HA) or salt (MA, M are ammonium, lithium, sodium, potassium and other cations that form a salt with the target anion) and the target ionic liquid (R)₄NA) is obtained.

<chemistry num="3"><img file="JP5019552B2_D0003.tif" /></chemistry> The hydroxide method is a method performed by the reactions shown in (4) to (8). First, the halide (R)₄NX) ion exchange membrane electrolysis (reaction formula (4)), OH type ion exchange resin method (reaction formula (5)) or silver oxide (Ag)₂Hydroxide (R) in reaction with O) (reaction equation (6))₄NOH) is obtained. (Chlorine, bromine, and iodine are used as halogens.) The obtained hydroxide is used as the target ionic liquid (R) using the reactions of reaction formulas (7) to (8) in the same manner as in the above halogenation method.₄NA) is obtained.

<chemistry num="4"><img file="JP5019552B2_D0004.tif" /></chemistry> The acid ester method is a method carried out by a reaction as shown in (9) to (11). First, tertiary amine (R)₃N) is reacted with an acid ester to obtain an acid ester product. (In the reaction formula (9), as the acid ester, an ester of an inorganic acid such as sulfuric acid, sulfite, phosphoric acid, arphoic acid or carbonic acid, or an ester of an organic acid such as methanesulfonic acid, methylphosphonic acid or formic acid is used). The obtained acid ester is used as the reaction of the reaction formulas (10) to (11) in the same manner as in the above-mentioned halogenation method, and the target ionic liquid (R) is used.₄NA) is obtained. Further, a direct ionic liquid can be obtained by using methyltrifluoromethanesulfonate, methyltrifluoroacetate or the like as the acid ester.

<chemistry num="5"><img file="JP5019552B2_D0005.tif" /></chemistry> The complex formation method is a method performed by the reactions shown in (12) to (15). First, a halide of quaternary ammonium (R)₄NX), quaternary ammonium hydroxide (R)₄NOH), quaternary ammonium carbonate esterified product (R)₄NOCO₂CH₃) Etc. as hydrogen fluoride (HF) or ammonium fluoride (NH)₄React with F) to obtain a quaternary ammonium fluoride salt. (Reaction equations (12) to (14)) The obtained quaternary ammonium fluoride salt is BF.₃, AlF₃, PF₅, ASF₅, SbF₅, NbF₅, TaF₅An ionic liquid can be obtained by a complex formation reaction with a fluoride such as. (Reaction equation (15))

<chemistry num="6"><img file="JP5019552B2_D0006.tif" /></chemistry> The neutralization method is a method performed by a reaction as shown in (16). Tertiary amines and HBF₄, HPF₆, CH₃COOH, CF₃COOH, CF₃SO₃H, (CF₃SO₂)₂NH, (CF₃SO₂)₃CH, (C₂F₅SO₂)₂It can be obtained by reacting with an organic acid such as NH.

<chemistry num="7"><img file="JP5019552B2_D0007.tif" /></chemistry> R represented by the above formulas (1) to (16) represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, and may contain a hetero atom.

The amount of the ionic liquid to be blended cannot be unconditionally defined because it varies depending on the compatibility between the acrylic polymer used and the ionic liquid, but in general, it is 0.01 to 40% by weight with respect to 100 parts by weight of the base polymer. Parts are preferable, 0.03 to 20 parts by weight is more preferable, and 0.05 to 10% by weight is most preferable. If it is less than 0.01 parts by weight, sufficient antistatic characteristics cannot be obtained, and if it exceeds 40 parts by weight, contamination of the adherend tends to increase.

In the present invention, a polymer having a glass transition temperature Tg of 0 ° C. or lower is used as the base polymer, preferably Tg is -100 to -5 ° C, and more preferably Tg is -80 to -10 ° C. is there. If the glass transition temperature Tg exceeds 0 ° C, it becomes difficult to obtain sufficient adhesive strength even when an ionic liquid is contained.

Examples of such polymers include acrylic polymers containing one or more of acrylates and / or methacrylates having an alkyl group having 1 to 14 carbon atoms as main components, natural rubbers, and styrene-isoprene-styrene block copolymers. SIS block copolymer), styrene-butadiene-styrene block copolymer (SBS block copolymer), styrene-ethylene / butylene-styrene block copolymer (SEBS block copolymer), styrene-butadiene rubber, polybutadiene, Examples of polymers that are generally applied as polymers of pressure-sensitive adhesives such as polyisoprene, polyisobutylene, butyl rubber, chloroprene rubber, and silicone rubber can be mentioned.

Among these, one or more of acrylates and / or methacrylates having an alkyl group having 1 to 14 carbon atoms are the main components because the balance of compatibility with ionic liquids and excellent adhesive properties can be obtained. Acrylic polymers are preferably used.

As an acrylic polymer containing one or more of acrylates and / or methacrylates having an alkyl group having 1 to 14 carbon atoms as a main component, acrylates having an alkyl group having 1 to 14 carbon atoms and / or Methacrylate {Hereafter referred to as (meth) acrylate. Acrylic polymer having a weight average molecular weight of 100,000 or more is used, which is mainly composed of a monomer containing 50 to 100% by weight of one or more of the above.

Specific examples of the (meth) acrylate having an alkyl group having 1 to 14 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, and isobutyl. (Meta) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl Examples thereof include (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, and n-tetradecyl (meth) acrylate.

As other components, Tg should be 0 ° C or less (usually -100 ° C or more) for the reason that the adhesive performance can be easily balanced, and sulfonic acid group-containing monomer, phosphoric acid group-containing monomer, and cyano group are appropriately used. Aggregating power / heat resistance improving components such as contained monomers, vinyl esters, aromatic vinyl compounds, carboxyl group-containing monomers, acid anhydride group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, amino group-containing monomers, epoxy It is possible to use a group-containing monomer, N-acryloylmorpholine, vinyl ethers and other components having a functional group that act as a base point for improving adhesive strength and cross-linking. Other ingredients can be used alone or in combination of two or more.

However, when an acrylate and / or methacrylate having an acid functional group such as a carboxyl group, a sulfonic acid group, or a phosphoric acid group is used, it is preferable to adjust the acid value of the acrylic polymer to be 29 or less. When the acid value of the acrylic polymer exceeds 29, the antistatic property tends to deteriorate.

The acid value can be adjusted by the blending amount of acrylate and / or methacrylate having an acid functional group. For example, an acrylic polymer obtained by copolymerizing 2-ethylhexyl acrylate and acrylic acid as an acrylic polymer having a carboxyl group can be mentioned. However, in this case, the above acid value value can be satisfied by adjusting the acrylic acid to 3.7 parts by weight or less with respect to 100 parts by weight of the total amount of 2-ethylhexyl acrylate and acrylic acid.

Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, and (meth) acryloyloxy. Examples include naphthalene sulfonic acid.

Examples of the phosphoric acid group-containing monomer include 2-hydroxyethylacryloyl phosphate. Examples of the cyano group-containing monomer include acrylonitrile. Examples of vinyl esters include vinyl acetate. Examples of the aromatic vinyl compound include styrene.

Examples of the carboxyl group-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid.

Examples of the acid anhydride group-containing monomer include maleic anhydride and itaconic anhydride.

Hydroxyl group-containing monomer as a-2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) Acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl acrylate, N-methylol (meth) acrylamide, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, Examples thereof include 4-hydroxybutyl vinyl ether and diethylene glycol monovinyl ether.

Examples of the amide group-containing monomer include acrylamide and diethyl acrylamide. Examples of the amino group-containing monomer include N, N-dimethylaminoethyl (meth) acrylate and N, N-dimethylaminopropyl (meth) acrylate. Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate and allyl glycidyl ether. Examples of vinyl ethers include vinyl ethyl ether.

The acrylic polymer is obtained by a polymerization method generally used as a method for synthesizing an acrylic polymer, such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization.

In the pressure-sensitive adhesive composition of the present invention, a pressure-sensitive adhesive layer having further excellent heat resistance can be obtained by appropriately cross-linking a base polymer, particularly an acrylic polymer. As a specific means of the cross-linking method, a compound having a group capable of reacting with a carboxyl group, a hydroxyl group, an amino group, an amide group, etc., which is appropriately included as a cross-linking base point in an acrylic polymer such as an isocyanate compound, an epoxy compound, and an aziridine compound. There is a method using a so-called cross-linking agent which is added and reacted.

Among these, examples of the isocyanate compound include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, and aliphatic isocyanates such as hexamethylene diisocyanate. Of these, isocyanate compounds and epoxy compounds are particularly preferably used from the viewpoint of obtaining an appropriate cohesive force. These compounds may be used alone or in combination of two or more.

More specifically, examples of the isocyanate compound include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate, 2,4-. Aromatic diisocyanates such as tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, trimethylolpropane / tolylene diisocyanate trimer adduct (trade name: Coronate L), trimethylolpropane / hexamethylene diisocyanate 3 amounts Examples thereof include body additives (trade name: Coronate HL) and isocyanate additives such as hexamethylene diisocyanate isocyanurate (trade name: Coronate HX) [both manufactured by Nippon Polyurethane Industry Co., Ltd.].

Epoxy compounds include N, N, N', N'-tetraglycidyl-m-xylene diamine (trade name TETRAD-X) and 1,3-bis (N, N-diglycidyl aminomethyl) cyclohexane (trade name TETRAD-). C) [All manufactured by Mitsubishi Gas Chemical Company, Inc.] and the like.

These cross-linking agents are used alone or in a mixture of two or more. The amount of the cross-linking agent used is appropriately selected depending on the balance with the acrylic polymer to be cross-linked and further depending on the intended use as an adhesive optical member. In order to obtain sufficient heat resistance due to the cohesive force of the acrylic pressure-sensitive adhesive, it is generally preferable to add 0.01 part by weight or more with respect to 100 parts by weight of the acrylic polymer. Further, from the viewpoint of flexibility and adhesiveness, it is preferable to add 15 parts by weight or less with respect to 100 parts by weight of the acrylic polymer.

Further, it can be added as a polyfunctional monomer having two or more radiation-reactive unsaturated bonds as a substantial cross-linking agent, and cross-linked by radiation or the like. One or more types of polyfunctional monomers having two or more radioreactive unsaturated bonds, such as vinyl group, acryloyl group, methacryloyl group, and vinylbenzyl group, which can be crosslinked (cured) by irradiation with radiation. A polyfunctional monomer component having two or more properties is used. Generally, those having 10 or less radiation-reactive unsaturated bonds are preferably used. It is also possible to use two or more kinds of polyfunctional monomers in combination.

Specific examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and 1,6 hexanediol di ( Examples thereof include meta) acrylate, trimethylrol propantri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, divinylbenzene, and N, N'-methylenebisacrylamide.

The amount of the polyfunctional monomer used is appropriately selected depending on the balance with the acrylic polymer to be crosslinked and further depending on the intended use as an adhesive sheet. In order to obtain sufficient heat resistance due to the cohesive force of the acrylic pressure-sensitive adhesive, it is generally preferable to blend 0.1 to 30 parts by weight with respect to 100 parts by weight of the acrylic polymer. Further, from the viewpoint of flexibility and adhesiveness, it is more preferable to blend 10 parts by weight or less with respect to 100 parts by weight of the acrylic polymer.

Examples of radiation include ultraviolet rays, laser rays, α-rays, β-rays, γ-rays, x-rays, electron beams, etc., and ultraviolet rays are preferably used from the viewpoint of controllability, ease of handling, and cost. More preferably, ultraviolet rays having a wavelength of 200 to 400 nm are used. Ultraviolet rays can be irradiated using an appropriate light source such as a high-pressure mercury lamp, a microwave excitation type lamp, or a chemical lamp. When ultraviolet rays are used as radiation, a photopolymerization initiator is added to the acrylic pressure-sensitive adhesive.

The photopolymerization initiator may be a substance that generates radicals or cations by irradiating with ultraviolet rays having an appropriate wavelength that can trigger the polymerization reaction, depending on the type of the radiation-reactive component.

Examples of photoradical polymerization initiators include benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, methyl o-benzoyl benzoate, benzoin isopropyl ether, α-methyl benzoin, benzyl dimethyl ketal, and trichloroacetophenone. , 2,2-Diethoxyacetophenone, acetophenones such as 1-hydroxycyclohexylphenylketone, propio such as 2-hydroxy-2-methylpropiophenone, 2-hydroxy-4'-isopropyl-2-methylpropiophenone Phenones, benzophenones, methylbenzophenones, p-chlorobenzophenones, benzophenones such as p-dimethylaminobenzofuninone, thioxanthones such as 2-chlorothioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)-(ethoxy) -phenylphosphine oxide and other acylphosphine oxides, benzyl, Examples thereof include dibenzosverone and α-acyloxym ester.

Examples of the photocationic polymerization initiator include onium salts such as aromatic diazonium salt, aromatic iodonium salt and aromatic sulfonium salt, organic metal complexes such as iron-allene complex, titanosen complex and arylsilanol-aluminum complex, and nitrobenzyl. Examples thereof include esters, sulfonic acid derivatives, phosphoric acid esters, sulfonic acid derivatives, phosphoric acid esters, phenol sulfonic acid esters, diazonaphthoquinones, and N-hydroxyimide sulfonates. It is also possible to use two or more of the above photopolymerization initiators in combination.

The photopolymerization initiator is preferably blended in the range of usually 0.1 to 10 parts by weight, preferably 0.2 to 7 parts by weight, based on 100 parts by weight of the acrylic polymer.

Further, it is also possible to use a photo-initiated polymerization aid such as amines in combination. Examples of the photoinitiator aid include 2-dimethylaminoethylbenzoate, dimethylaminoacetophenone, p-dimethylaminobenzoic acid ethyl ester, and p-dimethylaminobenzoic acid isoamyl ester. It is also possible to use two or more of the above photopolymerization initiation aids in combination. The polymerization initiator is preferably blended in the range of 0.05 to 10 parts by weight, more preferably 0.1 to 7 parts by weight, based on 100 parts by weight of the acrylic polymer.

The pressure-sensitive adhesive composition in the present invention may further contain an ethylene oxide group-containing compound. The ethylene oxide group-containing compound is not particularly limited as long as it is a compound having an ethylene oxide group, but is polyoxyethylene alkylamine, polyoxyethylenediamine, ethylene glycol group-containing acrylic polymer, ethylene oxide group-containing polyether polymer, and ethylene oxide group-containing poly. Examples thereof include ether ester amide, ethylene oxide group-containing polyether amide imide, polyoxyethylene glycol fatty acid ester, polyoxysorbitanoic acid fatty acid ester, polyoxyethylene alkylphenyl ether, and polyoxyethylene alkyl ether.

The blending amount of the ethylene oxide group-containing compound is 0.01 to 40 parts by weight, preferably 0.1 parts by weight to 20 parts by weight, based on 100 parts by weight of the base polymer. If it is less than 0.01 parts by weight, sufficient charging characteristics cannot be obtained, and if it exceeds 40 parts by weight, bleeding to the adherend tends to increase and the adhesive strength tends to decrease.

Further, the pressure-sensitive adhesive used in the pressure-sensitive optical member of the present invention includes various conventionally known pressure-sensitive adhesives, surface lubricants, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, ultraviolet absorbers, and polymerization inhibitors. Various conventionally known additives such as agents, silane coupling agents, inorganic or organic fillers, metal powders, powders such as pigments, particles, foils, etc. are appropriately added depending on the intended use. Can be done.

In the pressure-sensitive optical member of the present invention, the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition as described above is formed on one side or both sides of the optical member so that the thickness is usually about 3 to 200 μm, preferably about 10 to 100 μm. It is a thing. The pressure-sensitive adhesive layer can be formed by a method of directly applying the pressure-sensitive adhesive layer to an optical member, a method of transferring the pressure-sensitive adhesive layer once coated on another base material (for example, a release liner or the like), or the like.

As a method for forming the coating of the adhesive layer, a known method used for producing an adhesive tape is used, and specific examples thereof include a roll coating, a gravure coating, a reverse coating, a roll brush, a spray coating, and an air knife coating method. ..

As the optical member, those used for manufacturing various display devices and the like are used, and the type thereof is not particularly limited, but includes, for example, a polarizing plate, a retardation plate, a brightness improving plate, an antiglare sheet and the like. The optical member is a laminate of two or more layers of optical material, such as a laminate of a polarizing plate and a retardation plate, a laminate of a retardation plate, and a laminate of a polarizing plate and a brightness improving plate or an antiglare sheet. There may be.

For example, a polarizing plate having a transparent protective film on one side or both sides of a polarizing element is generally used.

The polarizer is not particularly limited, and various polarizers can be 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 copolymerization system partially saponified film, and two colors such as iodine and a bicolor dye are used. Examples thereof include a uniaxially stretched film by adsorbing a sex 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. The thickness of these polarizers is not particularly limited, but is preferably 1 μm to 1 mm, more preferably 20 μm to 200 μm in consideration of the strength as a film and the homogeneity during stretching.

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, it can be immersed in an aqueous solution of potassium iodide or the like, which may contain boric acid, zinc sulfate, zinc chloride or the like. 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 in an aqueous solution such as boric acid or potassium iodide or in a water bath.

As the material for forming the transparent protective film provided on one side or both sides of the polarizer, those having excellent transparency, mechanical strength, thermal stability, moisture shielding property, isotropic property and the like are preferable. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, and styrene such as polystyrene and acrylonitrile-styrene copolymer (AS resin). Examples include based polymers and polystyrene polymers. In addition, polyethylene, polypropylene, polyolefins having a cyclo- or norbornene structure, polyolefin-based polymers such as ethylene / propylene copolymers, vinyl chloride-based polymers, amide-based polymers such as nylon and aromatic polyamide, imide-based polymers, and sulfone-based 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 can also be formed as a cured layer of a thermosetting type or ultraviolet curable type resin such as acrylic type, urethane type, acrylic urethane type, epoxy type and silicone type.

Further, a polymer film described in JP-A-2001-343529 (WO01 / 37007), for example, a thermoplastic resin having a substituted and / or unsubstituted imide group in the (A) side chain and a (B) side chain. And / resin compositions containing a thermoplastic resin having an unsubstituted phenyl and a nitrile group can be mentioned. Specific examples include a film of a resin composition containing an alternating copolymer composed of isobutylene and N-methylmaleimide and an acrylonitrile / styrene copolymer. As the film, a film made of a mixed extruded product of a resin composition or the like can be used.

The thickness of the protective film can be appropriately determined, but is generally about 1 to 500 μm in terms of workability such as strength and handleability, and thin layer property. In particular, 1 to 300 μm is preferable, and 5 to 200 μm is more preferable.

Further, it is preferable that the protective film is not colored as much as possible. Therefore, it is expressed as Rth = [(nx + ny) / 2-nz] · d (where nx and ny are the main refractive index in the film plane, nz is the refractive index in the film thickness direction, and d is the film thickness). A protective film having a retardation value in the film thickness direction of -90 nm to + 75 nm is preferably used. By using a polarizing plate having a retardation value (Rth) of 90 nm to + 75 nm in the thickness direction, the coloring (optical coloring) of the polarizing plate due to the protective film can be almost eliminated. The thickness direction retardation value (Rth) is more preferably -80 nm to + 60 nm, and particularly preferably 70 nm to + 45 nm.

As the protective film, a cellulosic polymer such as triacetyl cellulose is preferable from the viewpoint of polarization characteristics and durability. A triacetyl cellulose film is particularly suitable. When protective films are provided on both sides of the polarizer, protective films made of the same polymer material may be used on the front and back sides thereof, or protective films made of different polymer materials may be used. The polarizer and the protective film are usually in close contact with each other via an aqueous adhesive or the like. Examples of the water-based adhesive include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex-based adhesives, water-based polyurethanes, and water-based polyesters.

The surface of the transparent protective film to which the polarizer is not adhered may be subjected to a hard coat layer, antireflection treatment, anti-sticking treatment, or treatment for the purpose of diffusion or anti-glare.

The hard coat treatment is applied for the purpose of preventing scratches on the surface of the polarizing plate. For example, a transparent protective film is made of a cured film having excellent hardness and slipperiness by an appropriate ultraviolet curable resin such as acrylic or silicone. It can be formed by a method of adding to the surface of. The antireflection treatment is applied for the purpose of preventing the reflection of external light on the surface of the polarizing plate, and can be achieved by forming an antireflection film or the like according to the conventional method. Further, the anti-sticking treatment is applied for the purpose of preventing adhesion to the adjacent layer.

Further, the anti-glare treatment is applied for the purpose of preventing external light from being reflected on the surface of the polarizing plate and obstructing the visibility of the transmitted light of the polarizing plate. It can be formed by imparting a fine concavo-convex structure to the surface of the transparent protective film by an appropriate method such as a method of blending transparent fine particles. Examples of the fine particles contained in the formation of the surface fine uneven structure include conductivity made of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide, etc. having an average particle diameter of 0.5 to 50 μm. Transparent fine particles such as organic fine particles made of certain inorganic fine particles, crosslinked or uncrosslinked polymers, etc. are used. When forming the surface fine concavo-convex structure, the amount of fine particles used is generally about 2 to 50 parts by weight, preferably 5 to 25 parts by weight, based on 100 parts by weight of the transparent resin forming the surface fine concavo-convex structure. The anti-glare layer may also serve as a diffusion layer (such as a viewing angle enlargement function) for diffusing the light transmitted through the polarizing plate to expand the viewing angle and the like.

The antireflection layer, the sticking prevention layer, the diffusion layer, the antiglare layer and the like can be provided on the transparent protective film itself, or can be separately provided as an optical layer separately from the transparent protective film.

For example, an antiglare layer formed in the form of a sheet or formed on a transparent base material is an antiglare sheet. The thickness of the antiglare sheet is not particularly limited, but 1 μm to 1 mm is preferably used in consideration of the strength of the sheet.

The optical member of the present invention includes, for example, a reflecting plate, a transflective plate, a retardation plate (including a wave plate such as 1/2 or 1/4), a viewing angle compensation film, a liquid crystal display device such as a brightness improving film, or the like. An example is an optical layer that may be used for formation. These can be used alone as the optical member of the present invention, or can be laminated on the polarizing plate in practical use to use one layer or two or more layers.

In particular, a reflective polarizing plate or a semi-transmissive polarizing plate in which a reflecting plate or a semi-transmissive polarizing plate is further laminated on a polarizing plate, an elliptical polarizing plate or a circular polarizing plate in which a retardation plate is further laminated on a polarizing plate, and polarized light. A wide viewing angle polarizing plate in which a viewing angle compensating film is further laminated on the plate, or a polarizing plate in which a brightness improving film is further laminated on the polarizing plate is preferable.

The reflective polarizing plate is a polarizing plate provided with a reflective layer, and is used to form a liquid crystal display device of a type that reflects and displays incident light from the viewing side (display side), and is a backlight. It has the advantage that the built-in light source such as the above can be omitted and the liquid crystal display device can be easily made thinner. The reflective polarizing plate can be formed by an appropriate method such as a method in which a reflective layer made of metal or the like is attached to one side of the polarizing plate via a transparent protective layer or the like, if necessary.

Specific examples of the reflective polarizing plate include those in which a foil made of a reflective metal such as aluminum or a vapor-deposited film is attached to one side of a transparent protective film that has been matted, if necessary, to form a reflective layer. Further, the transparent protective film may contain fine particles to form a surface fine concavo-convex structure, and a reflective layer having a fine concavo-convex structure may be provided on the surface. The reflection layer having the fine concavo-convex structure described above has an advantage that the incident light is diffused by diffuse reflection to prevent directivity and glaring appearance, and unevenness of light and darkness can be suppressed. Further, the transparent protective film containing fine particles has an advantage that the incident light and the reflected light thereof are diffused when transmitted through the transparent protective film and can further suppress the unevenness of light and darkness. To form a reflective layer with a fine uneven structure that reflects the fine uneven structure on the surface of the transparent protective film, the metal is transparent by, for example, a vapor deposition method such as a vacuum vapor deposition method, an ion plating method, or a sputtering method, or an appropriate method such as a plating method. This can be done by a method of directly attaching to the surface of the protective layer.

The reflector can be used as a reflective sheet or the like in which a reflective layer is provided on an appropriate film according to the transparent film, instead of the method of directly applying the reflective plate to the transparent protective film of the polarizing plate. Since the reflective layer is usually made of metal, the usage pattern in which the reflective surface is covered with a transparent protective film, a polarizing plate, or the like prevents a decrease in reflectance due to oxidation, and eventually the initial reflectance is maintained for a long period of time. It is more preferable in terms of avoiding the attachment of a protective layer separately.

The semi-transmissive polarizing plate can be obtained by using a semi-transmissive reflective layer such as a half mirror that reflects and transmits light in the reflective layer. The transflective polarizing plate is usually provided on the back side of the liquid crystal cell, and when the liquid crystal display device or the like is used in a relatively bright atmosphere, the incident light from the visual recognition side (display side) is reflected to display the image. In a relatively dark atmosphere, a liquid crystal display device of a type that displays an image can be formed by using a built-in light source such as a backlight built in the back side of the transflective polarizing plate. That is, the transflective polarizing plate can save energy for using a light source such as a backlight in a bright atmosphere, and is useful for forming a type of liquid crystal display device or the like that can be used using a built-in light source even in a relatively dark atmosphere. Is.

An elliptical polarizing plate or a circular polarizing plate in which a retardation plate is further laminated on the polarizing plate will be described. A retardation plate or the like is used when changing linearly polarized light to elliptically polarized light or circularly polarized light, changing elliptically polarized light or circularly polarized light to linearly polarized light, or changing the polarization direction of linearly polarized light. In particular, a so-called 1/4 wave plate (also referred to as a λ / 4 plate) is used as a retardation plate that changes linearly polarized light into circularly polarized light or changes circularly polarized light into linearly polarized light. A 1/2 wave plate (also called a λ / 2 plate) is usually used to change the polarization direction of linearly polarized light.

The elliptical polarizing plate is effectively used for black-and-white display without the coloring by compensating (preventing) the coloring (blue or yellow) caused by the birefringence of the liquid crystal layer of the super twisted nematic (STN) type liquid crystal display device. Be done. Further, the one in which the three-dimensional refractive index is controlled is preferable because it can compensate (prevent) the coloring that occurs when the screen of the liquid crystal display device is viewed from an oblique direction. The circular polarizing plate is effectively used, for example, when adjusting the color tone of an image of a reflective liquid crystal display device that displays an image in color, and also has an antireflection function.

Examples of the retardation plate 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 plate is not particularly limited, but is generally about 20 to 150 μm.

Examples of the polymer material include polyvinyl alcohol, polyvinyl butyral, polymethylvinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, polysulfone, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, and the like. Polyphenylene sulphide, polyphenylene oxide, polyallylsulfone, polyvinyl alcohol, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose-based polymer, norbornene-based 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. Be done. Specific examples of the main chain type liquid crystal polymer include a nematically oriented polyester liquid crystal polymer, a discotic polymer, a cholesteric polymer, and the like having a structure in which a mesogen group is bonded at a spacer portion that imparts flexibility. .. As a specific example of the side chain type liquid crystal polymer, polysiloxane, polyacrylate, polymethacrylate or polymalonate is used as a main chain skeleton, and a paranematic orientation-imparting para is provided via a spacer portion composed of a conjugated atomic group as a side chain. Examples thereof include those having a mesogen moiety composed of a substituted 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, for example, 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.

Further, the above-mentioned elliptical polarizing plate and reflective elliptical polarizing plate are obtained by laminating a polarizing plate or a reflective polarizing plate and a retardation plate in an appropriate combination. Such an elliptical polarizing plate or the like can also be formed by sequentially and separately laminating them in the manufacturing process of the liquid crystal display device so as to form a combination of the (reflective) polarizing plate and the retardation plate, but as described above, the elliptical polarizing plate and the like are formed in advance. An optical member such as a polarizing plate has an advantage that it is excellent in quality stability and laminating workability and can improve the manufacturing efficiency of a liquid crystal display device or the like.

The viewing angle compensation film is a film for widening the viewing angle so that the image can be seen relatively clearly even when the screen of the liquid crystal display device is viewed from a direction slightly oblique rather than perpendicular to the screen. Such a viewing angle compensation retardation plate includes, for example, a retardation plate, an alignment film such as a liquid crystal polymer, or a transparent base material on which an alignment layer such as a liquid crystal polymer is supported. A normal retardation plate uses a polymer film having birefringence stretched uniaxially in the plane direction, whereas a retardation plate used as a viewing angle compensation film is stretched biaxially in the plane direction. Polymer films with birefringence, polymers with birefringence that are uniaxially stretched in the plane direction and stretched in the thickness direction with controlled refractive index in the thickness direction, bidirectional stretched films such as tilt-aligned films, etc. Used. Examples of the tilt-aligned film include a film in which a heat-shrinkable film is adhered to a polymer film and the polymer film is stretched or / or shrunk under the action of the shrinkage force due to heating, or a liquid crystal polymer is obliquely oriented. Can be mentioned. As the raw material polymer of the retardation plate, the same polymer as that described in the above retardation plate is used to prevent coloring due to a change in the viewing angle based on the phase difference due to the liquid crystal cell and to expand the viewing angle for good visibility. An appropriate one for the purpose of the above can be used.

In addition, from the viewpoint of achieving a wide viewing angle with good visibility, an optically compensated phase difference in which an optically anisotropic layer composed of an oriented layer of a liquid crystal polymer, particularly a tilted oriented layer of a discotic liquid crystal polymer, is supported by a triacetyl cellulose film. A plate can be preferably used.

A polarizing plate in which a polarizing plate and a brightness improving film are bonded is usually provided on the back side of a liquid crystal cell and used. The brightness-enhancing film reflects the linearly polarized light of the predetermined polarizing axis or the circularly polarized light in the predetermined direction when natural light is incident due to the backlight of a liquid crystal display device or the reflection from the back side, and exhibits the property of transmitting other light. In the polarizing plate in which the brightness improving film is laminated with the polarizing plate, light from a light source such as a backlight is incident to obtain transmitted light in a predetermined polarized state, and light other than the predetermined polarized state is reflected without being transmitted. To. The light reflected on the surface of the luminance improving film is further inverted via a reflective layer or the like provided behind the surface of the luminance improving film to be re-incidented on the luminance improving film, and a part or all of the light is transmitted as light in a predetermined polarized state to provide brightness. The brightness can be improved by increasing the amount of light transmitted through the improving film and increasing the amount of light that can be used for displaying images on a liquid crystal display by supplying polarized light that is difficult to be absorbed by the polarizer. That is, when light is incident through a polarizing element from the back side of a liquid crystal cell with a backlight or the like without using a brightness improving film, the light having a polarization direction that does not match the polarization axis of the polarizer is almost polarized. It is absorbed by the child and does not pass through the polarizer. That is, although it depends on the characteristics of the polarizer used, about 50% of the light is absorbed by the polarizer, and the amount of light that can be used for displaying a liquid crystal image or the like is reduced by that amount, and the image becomes dark. In the brightness improving film, light having a polarization direction that is absorbed by the polarizer is temporarily reflected by the brightness improving film without being incident on the polarizer, and is further inverted via a reflection layer or the like provided behind the polarizing element. The brightness-improving film transmits only the polarized light whose polarization direction is such that the polarization direction of the light reflected and inverted between the two can pass through the polarizer. Since it is supplied to the polarizing element, light such as a backlight can be efficiently used for displaying an image on a liquid crystal display device, and the screen can be brightened.

A diffuser plate may be provided between the brightness improving film and the reflective layer or the like. The light in the polarized state reflected by the brightness improving film goes toward the reflection layer and the like, but the installed diffuser plate uniformly diffuses the passing light and at the same time eliminates the polarized state and becomes a non-polarized state. That is, the diffuser returns the polarized light to the original natural light state. The light in the non-polarized state, that is, the natural light state, goes toward the reflective layer or the like, is reflected through the reflective layer or the like, passes through the diffuser plate again, and is re-entered on the luminance improving film. By providing a diffusing plate that restores polarized light to the original natural light state between the brightness improving film and the reflective layer, the brightness of the display screen is maintained, and at the same time, the unevenness of the brightness of the display screen is reduced. A uniform and bright screen can be provided. It is considered that by providing such a diffusing plate, the number of times of reflection of the first incident light is moderately increased, and a uniform and bright display screen can be provided in combination with the diffusing function of the diffusing plate.

The brightness improving film has a characteristic of transmitting linearly polarized light of a predetermined polarization axis and reflecting other light, such as a multilayer thin film of a dielectric or a multilayer laminate of thin film films having different refractive index anisotropies. It shows the property of reflecting either left-handed or right-handed circularly polarized light and transmitting other light, such as an oriented film of cholesteric liquid crystal polymer or one in which the oriented liquid crystal layer is supported on a film substrate. Appropriate ones such as those can be used.

Therefore, in the above-mentioned type of brightness improving film that transmits linearly polarized light of a predetermined polarization axis, the transmitted light is efficiently transmitted while suppressing absorption loss by the polarizing plate by directly incident the transmitted light on the polarizing plate with the polarization axes aligned. Can be made to. On the other hand, in a brightness-improving film of the type that drops circularly polarized light, such as a cholesteric liquid crystal layer, it is possible to directly incident on the polarizer, but the circularly polarized light is linearly polarized via a retardation plate from the viewpoint of suppressing absorption loss. It is preferable to make it incident on the polarizing plate. By using a 1/4 wave plate as the retardation plate, circularly polarized light can be converted into linearly polarized light.

A retardation plate that functions as a 1/4 wave plate in a wide wavelength range such as the visible light region exhibits a retardation layer that functions as a 1/4 wave plate and other retardation characteristics for light-colored light having a wavelength of 550 nm, for example. It can be obtained by a method of superimposing a retardation layer, for example, a retardation layer functioning as a 1/2 wavelength plate. Therefore, the retardation plate arranged between the polarizing plate and the luminance improving film may be composed of one layer or two or more retardation layers.

It should be noted that the cholesteric liquid crystal layer also has a structure in which two or three or more layers are superimposed by combining those having different reflection wavelengths to obtain a layer that reflects circular polarization in a wide wavelength range such as a visible light region. Based on this, transmitted circular polarization in a wide wavelength range can be obtained.

Further, the polarizing plate may be formed by laminating a polarizing plate and two or three or more optical layers like the above-mentioned polarization separation type polarizing plate. Therefore, the above-mentioned reflective polarizing plate or semi-transmissive polarizing plate and a retardation plate may be combined to be a reflective elliptical polarizing plate or a semi-transmissive elliptical polarizing plate.

The optical member in which the optical layer is laminated on the polarizing plate can also be formed by a method in which the optical members are sequentially and separately laminated in the manufacturing process of a liquid crystal display device or the like. It is excellent in stability and assembly work, and has an advantage that it can improve the manufacturing process of a liquid crystal display device or the like. An appropriate adhesive means such as an adhesive layer can be used for laminating. When adhering the polarizing plate to another optical layer, the optical axes of the polarizing plate can be set to an appropriate arrangement angle according to a target phase difference characteristic or the like.

In addition, in each layer such as the optical member and the pressure-sensitive adhesive layer of the adhesive type optical member of the present invention, for example, ultraviolet rays such as salicylate ester compound, benzophenol compound, benzotriazole compound, cyanoacrylate compound, nickel complex salt compound and the like are applied to each layer. It may be one having an ultraviolet absorbing ability by a method such as a method of treating with an absorbent.

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

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

Next, an organic electroluminescence device (organic EL display device) will be described. Generally, in an organic EL display device, a transparent electrode, an organic light emitting layer, and a metal electrode are laminated in this order on a transparent substrate to form a light emitting body (organic electroluminescence light emitting body). Here, the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative or the like and a light emitting layer made of a fluorescent organic solid such as anthracene, or Alternatively, a configuration having various combinations such as a laminate of an electron injection layer composed of such a light emitting layer and a perylene derivative, or a laminate of these hole injection layers, a light emitting layer, and an electron injection layer is known. Has been done.

In the organic EL display device, holes and electrons are injected into the organic light emitting layer by applying a voltage to the transparent electrode and the metal electrode, and the energy generated by the recombination of these holes and electrons excite the fluorescent material. Then, it emits light on the principle that the excited fluorescent substance emits light when it returns to the ground state. The mechanism of recombination in the middle is the same as that of a general diode, and as can be expected from this, the current and the emission intensity show strong non-linearity with rectification with respect to the applied voltage.

In an organic EL display device, at least one electrode must be transparent in order to extract light emitted from the organic light emitting layer, and a transparent electrode usually formed of a transparent conductor such as indium tin oxide (ITO) is used as an anode. It is used as. On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a substance with a small work function for the cathode, and metal electrodes such as Mg-Ag and Al-Li are usually used.

In the organic EL display device having such a configuration, the organic light emitting layer is formed of an extremely thin film having a thickness of about 10 nm. Therefore, the organic light emitting layer, like the transparent electrode, transmits light almost completely. As a result, the light that is incident from the surface of the transparent substrate when it is not emitting light, passes through the transparent electrode and the organic light emitting layer, and is reflected by the metal electrode is emitted to the surface side of the transparent substrate again. The display surface of the organic EL display device looks like a mirror surface.

In an organic EL display device including an organic electroluminescent illuminant having a transparent electrode on the front surface side of an organic light emitting layer that emits light by applying a voltage and a metal electrode on the back surface side of the organic light emitting layer, the surface of the transparent electrode. A polarizing plate may be provided on the side, and a retardation plate may be provided between these transparent electrodes and the polarizing plate.

Since the retardation plate and the polarizing plate have an action of polarizing the light incident from the outside and reflected by the metal electrode, there is an effect that the mirror surface of the metal electrode is not made visible from the outside by the polarization action. In particular, if the retardation plate is composed of a 1/4 wave plate and the angle formed by the polarizing plate and the retardation plate in the polarization direction is adjusted to π / 4, the mirror surface of the metal electrode can be completely shielded. ..

That is, only the linearly polarized light component is transmitted by the polarizing plate to the external light incident on the organic EL display device. This linearly polarized light is generally elliptically polarized by the retardation plate, but it becomes circularly polarized light especially when the retardation plate is a 1/4 wave plate and the angle between the polarizing plate and the retardation plate is π / 4. ..

This circularly polarized light passes through the transparent substrate, the transparent electrode, and the organic thin film, is reflected by the metal electrode, passes through the organic thin film, the transparent electrode, and the transparent substrate again, and becomes linearly polarized light again on the retardation plate. Since this linearly polarized light is orthogonal to the polarization direction of the polarizing plate, it cannot pass through the polarizing plate. As a result, the mirror surface of the metal electrode can be completely shielded.

In the adhesive optical member of the present invention, a separator can be attached to the surface of the adhesive for the purpose of protecting the adhesive surface, if necessary. Paper and a plastic film are examples of the base material constituting the separator, and the plastic film is preferably used because of its excellent surface smoothness.

The film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer, and is, for example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, or a vinyl chloride copolymer. Examples thereof include a film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film.

The thickness of the film is usually about 5 to 200 μm, preferably about 10 to 100 μm. The pressure-sensitive adhesive layer-bonded surface of the film is appropriately treated with a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based mold release agent, silica powder, or the like.

The adhesive optical member of the present invention is preferably used in the manufacture of various display devices such as liquid crystal display devices and touch panels. It is also possible to use an ultraviolet absorber or the like to impart an ultraviolet absorbing ability to an optical material such as a polarizing plate, a retardation plate, a brightness improving plate, or an antiglare sheet forming an optical member. Examples of the ultraviolet absorber include salicylic acid ester compounds, benzophenone compounds, benzotriazole compounds, cyanoacrylate compounds, nickel complex salt compounds and the like.

Hereinafter, examples and the like that specifically show the configuration and effects of the present invention will be described. The evaluation items in the examples and the like were measured as follows.

[Acid value] The acid value was measured using an automatic titrator COM-550 manufactured by Hiranuma Sangyo Co., Ltd., and was calculated from the following formula. A = {(YX) × f × 5.611} / M A; Acid value, Y; Titration of sample solution (ml), X; Titration of solution of mixed solvent only 50g (ml), f; Factor of titration solution, M; Weight of polymer sample (g) The measurement conditions are as follows. Sample solution: About 0.5 g of a polymer sample was dissolved in 50 g of a mixed solvent (toluene / 2-propanol / distilled water = 50 / 49.5 / 0.5, weight ratio) to prepare a sample solution. Titration solution: 0.1N, 2-propanol potassium hydroxide solution (manufactured by Wako Pure Chemical Industries, Ltd., for petroleum product neutralization value test), electrode: glass electrode; GE-101, comparative electrode; RE-201, Measurement mode: Petroleum product neutralization value test 1.

[Molecular weight] The molecular weight was measured using a GPC device manufactured by Tosoh Corporation, HLC-8220GPC, and was determined by a polystyrene conversion value. The measurement conditions are as follows. Sample concentration: 0.2wt% (THF solution), sample injection volume: 10 μl, eluent: THF, flow velocity: 0.6 ml / min, measurement temperature: 40 ° C, column: sample column; TSKguardcolumn SuperHZ-H 1 bottle + TSKgelSuperHZM-H2 Book, reference column; 1 TSKgel SuperH-RC, detector: differential refractometer.

[Glass-transition temperature] The glass transition temperature Tg (° C) was calculated by the following formula using the following literature values as the glass transition temperature Tgn (° C) of the homopolymer by each monomer. Equation: 1 / (Tg + 273) = Σ [Wn / (Tgn + 273)] [In the formula, Tg (° C) is the glass transition temperature of the copolymer, Wn (-) is the weight fraction of each monomer, Tgn (° C) is the glass transition temperature of the homopolymer by each monomer, and n is each monomer. Represents the type of. ] 2-Ethylhexyl acrylate: -70 ° C 2-Hydroxyethyl acrylate: -15 ° C Butyl acrylate: -55 ° C Acrylic acid: 106 ° C Diethyl acrylamide: 81 ° C.

Production Example 1 (Acrylic Polymer A) A mixture of 200 g of 2-ethylhexyl acrylate, 8 g of 2-hydroxyethyl acrylate, 0.4 g of 2,2'-azobisisobutyronitrile, and 312 g of ethyl acetate was reacted at 65 ° C for 6 hours in a nitrogen stream to Tg = A solution (40% by weight) of an acrylic polymer having a weight average molecular weight of 500,000 and an acid value of 0 was obtained at -68 ° C.

Production Example 2 (Acrylic Polymer B) A mixture of 200 g of n-butyl acrylate, 8 g of 2-hydroxyethyl acrylate, 0.4 g of 2,2'-azobisisobutyronitrile, and 625 g of ethyl acetate was reacted at 65 ° C for 6 hours in a nitrogen stream to Tg. A solution (25% by weight) of an acrylic polymer having a weight average molecular weight of 540,000 and an acid value of 0 was obtained at -54 ° C.

Production Example 3 (Acrylic Polymer C) A mixture of 156 g of 2-ethylhexyl acrylate, 40 g of diethyl acrylamide, 4 g of acrylic acid, 0.4 g of 2,2'-azobisisobutyronitrile, and 300 g of ethyl acetate was reacted at 65 ° C for 6 hours in a nitrogen stream to Tg. A solution (40% by weight) of an acrylic polymer having a weight average molecular weight of 560,000 and an acid value of 15 was obtained at 49 ° C.

Production Example 4 (polarizing plate) After swelling a polyvinyl alcohol film with a degree of polymerization of 1700 and a thickness of 80 μm in a warm water bath at 30 ° C for 1 minute, an aqueous solution of 0.3 wt% iodine (30 °) consisting of iodine and potassium iodide (weight ratio = 1:10) It was stretched about 3 times in C), and then stretched in a 4 wt% boric acid aqueous solution at 50 ° C. so that the total stretching ratio was 6 times. Subsequently, it was immersed in a 4 wt% potassium iodide aqueous solution at 30 ° C. for 5 seconds and then dried at 40 ° C. for 5 minutes to obtain a polarizer. A polarizing plate was prepared by laminating a saponified triacetyl cellulose film having a thickness of 80 μm on both sides of the polarizer using an adhesive composed of a 7 wt% polyvinyl alcohol aqueous solution. The saponification treatment was carried out by immersing in a 60 ° C aqueous sodium hydroxide solution (10% by weight) for 1 minute.

Example 1 (Preparation of Adhesive Composition) The solution of acrylic polymer A (40% by weight) obtained in Production Example 1 was diluted to 20% by weight with ethyl acetate, and glycidyltrimethylammonium trifluoromethanesulfonate (liquid at 25 ° C) 2.0 as an ionic liquid in 100 g of this solution. An acrylic pressure-sensitive adhesive solution was prepared by adding 0.13 g of trimethylolpropane / tolylene diisocyanate trimer adduct (trade name: Coronate L).

(Manufacturing of adhesive optical member) The acrylic pressure-sensitive adhesive solution was applied to the silicone-treated surface of a polyethylene terephthalate film having a thickness of 38 μm and heated at 110 ° C. for 3 minutes to form a pressure-sensitive adhesive layer having a thickness of 25 μm. Next, the polarizing plate produced in Production Example 4 was bonded to the pressure-sensitive adhesive layer surface to prepare an adhesive optical member.

Example 2 (Preparation of Adhesive Composition) The solution of acrylic polymer B (25% by weight) obtained in Production Example 2 was diluted to 20% by weight with ethyl acetate, and 1-butyl-3-methylpyridinium trifluoromethanesulfonate (25 ° C) was added to 100 g of this solution as an ionic liquid. An acrylic pressure-sensitive adhesive solution was prepared by adding 0.2 g of (liquid in C) and 0.13 g of trimethylolpropane / tolylene diisocyanate trimer adduct (trade name: Coronate L).

(Manufacturing of adhesive optical member) An adhesive optical member was produced in the same manner as in Example 1 except that the acrylic adhesive solution prepared above was used as the acrylic adhesive solution.

Example 3 (Preparation of Adhesive Composition) The acrylic polymer solution (40% by weight) obtained in Production Example 3 was diluted to 20% by weight with ethyl acetate, and diallyldimethylammonium trifluoromethanesulfonate (liquid at 25 ° C) 2.0 g as an ionic liquid in 100 g of this solution. , Trimethylol propane / tolylene diisocyanate trimer adduct (trade name: Goronate L) 0.13 g was added to prepare an acrylic pressure-sensitive adhesive solution.

(Manufacturing of adhesive optical member) An optical member was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution prepared above was used as the acrylic pressure-sensitive adhesive solution.

Example 4 (Preparation of Adhesive Composition) The solution of acrylic polymer A (40% by weight) obtained in Production Example 1 was diluted to 20% by weight with ethyl acetate, and glycidyltrimethylammonium bis (trifluoromethanesulfonyl) imide (25 ° C) was added to 100 g of this solution as an ionic liquid. To prepare an acrylic pressure-sensitive adhesive solution, 2.0 g of (liquid) and 0.13 g of trimethylolpropane / tolylene diisocyanate trimer adduct (trade name: Coronate L) were added.

(Manufacturing of adhesive optical member) The acrylic pressure-sensitive adhesive solution was applied to the silicone-treated surface of a polyethylene terephthalate film having a thickness of 38 μm and heated at 110 ° C. for 3 minutes to form a pressure-sensitive adhesive layer having a thickness of 25 μm. Next, the polarizing plate produced in Production Example 4 was bonded to the pressure-sensitive adhesive layer surface to prepare an adhesive optical member.

Example 5 (Preparation of Adhesive Composition) The solution of acrylic polymer B (25% by weight) obtained in Production Example 2 was diluted to 20% by weight with ethyl acetate, and 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) was added to 100 g of this solution as an ionic liquid. An acrylic pressure-sensitive adhesive solution was prepared by adding 0.2 g of imide (liquid at 25 ° C) and 0.13 g of trimethylolpropane / tolylene diisocyanate trimer adduct (trade name: Coronate L).

(Manufacturing of adhesive optical member) An adhesive optical member was produced in the same manner as in Example 1 except that the acrylic adhesive solution prepared above was used as the acrylic adhesive solution.

Example 6 (Preparation of Adhesive Composition) The acrylic polymer solution (40% by weight) obtained in Production Example 3 was diluted to 20% by weight with ethyl acetate, and diallyldimethylammonium bis (trifluoromethanesulfonyl) imide (at 25 ° C) was added to 100 g of this solution as an ionic liquid. An acrylic pressure-sensitive adhesive solution was prepared by adding 2.0 g of liquid) and 0.13 g of trimethylolpropane / tolylene diisocyanate trimer adduct (trade name: Goronate L).

(Manufacturing of adhesive optical member) An optical member was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution prepared above was used as the acrylic pressure-sensitive adhesive solution.

Comparative example 1 An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 1 except that an ionic liquid was not used. A pressure-sensitive optical member was produced in the same manner as in Example 1 except that this acrylic pressure-sensitive adhesive solution was used as the acrylic pressure-sensitive adhesive solution.

Comparative example 2 An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 2 except that an ionic liquid was not used. An adhesive optical member was produced in the same manner as in Example 1 except that this acrylic adhesive solution was used as the acrylic adhesive solution.

Comparative example 3 An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 3 except that an ionic liquid was not used. An optical member was produced in the same manner as in Example 1 except that this acrylic pressure-sensitive adhesive solution was used as the acrylic pressure-sensitive adhesive solution.

With respect to the optical members obtained in Examples 1 to 6 and Comparative Examples 1 to 3 above, the peeling band voltage and the adhesive strength were confirmed in the following manner.

Production Example 5 (Preparation of antistatic polyethylene terephthalate film) Antistatic agent composed of tin oxide and polyester resin [Microsolver RMd-142 manufactured by Solvex Co., Ltd.] diluted with a mixed solvent consisting of 30 g of water and 70 g of methanol, and a Meyer bar was used for a 38 μm-thick polyethylene terephthalate film. And heated at 130 ° C. for 1 minute to form an antistatic layer with a thickness of 0.2 μm to prepare an antistatic treated polyethylene terephthalate film.

Production Example 6 (Preparation of Adhesive Composition) The solution of acrylic polymer A (40% by weight) obtained in Production Example 1 was diluted to 20% by weight with ethyl acetate, and 100 g of this solution was added to an isocyanurate form of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd.). An acrylic pressure-sensitive adhesive solution was prepared by adding 0.8 g of coronate HX) and 0.4 g of dibutyltin dilaurate (1 wt% ethyl acetate solution) as a cross-linking catalyst.

Production Example 7 (Preparation of protective film) The acrylic pressure-sensitive adhesive solution is applied to the surface of the antistatic-treated polyethylene terephthalate film obtained in Production Example 5 opposite to the antistatic-treated surface, and heated at 110 ° C. for 3 minutes to obtain a pressure-sensitive adhesive having a thickness of 20 μm. A layer was formed. Next, a protective film was prepared by laminating a silicone-treated surface of a 25 μm-thick polyethylene terephthalate film having one surface treated with silicone on the surface of the pressure-sensitive adhesive layer.

[Peeling band voltage] After peeling off the separator of the adhesive optical member cut to a size of 70 mm in width and 100 mm in length, it is attached to an acrylic plate with a thickness of 1 mm, width of 70 mm and length of 100 mm that has been statically removed in advance with a hand roller. The body was made. The protective film obtained in Production Example 7 is cut into a size of 70 mm in width and 130 mm in length, the separator is peeled off, and then one end of the protective film protrudes 30 mm from the surface of the polarizing plate of the adherend which has been statically eliminated in advance. Crimping with a hand roller. After leaving it in an environment of 23 ° C x 50% RH for a day, set the sample in place as shown below. Fix one end that protrudes 30 mm to the automatic winder, and peel it so that the peeling angle is 150 ° and the peeling speed is 10 m / min. The potential on the surface of the polarizing plate generated at this time was measured with a potential measuring machine [KSD-0103, manufactured by Kasuga Electric Co., Ltd.] fixed at a predetermined position. The measurement was performed in an environment of 23 ° C × 50% RH.

[Adhesive strength measurement] After peeling off the separator of the adhesive optical member cut to a width of 25 mm and a length of 100 mm, a pressure of 0.25 MPa is applied to a slide glass (manufactured by Matsunami Glass Industry Co., Ltd., water edge polishing) with a thickness of 1.3 mm, a width of 65 mm and a length of 165 mm. To prepare an evaluation sample by laminating with. After being left for 30 minutes after laminating, the adhesive strength when peeled at a peeling speed of 300 mm / min and a peeling angle of 90 ° was measured with a universal tensile tester. The measurement was performed in an environment of 23 ° C × 50% RH.

The above results are shown in Table 1.

<tables num="1"><img file="JP5019552B2_D0008.tif" /></tables> As is clear from the results in Table 1 above, in all of the adhesive optical members of Examples 1 to 6 of the present invention, the peeling band voltage is suppressed as compared with Comparative Examples 1 to 3. In addition, the adhesive optical members of Examples 1 to 6 of the present invention all show the same adhesive strength as Comparative Examples 1 to 3. Therefore, it can be seen that the adhesive optical members of Examples 1 to 6 are adhesive optical members having excellent antistatic properties and adhesive properties.

<figref num="1">Schematic configuration diagram of the potential measuring unit used for measuring the peeling band voltage in the examples and the like.</figref>