JP5791160B2 - Adhesive optical member - Google Patents

Description

  The present invention relates to an adhesive optical member having an optical member provided with an antistatic adhesive layer. The present invention is suitably used for an adhesive optical member using a plastic material that is likely to generate static electricity. Especially, it is useful as an adhesive optical member used for a liquid crystal display or a touch panel.

  In a liquid crystal display and a touch panel, various optical films such as a polarizing plate and a wave plate are laminated and used via an adhesive layer in order to control and adjust the vibration direction and phase difference of light. These optical films are distributed in a bonded form such as separators for the purpose of protecting the adhesive surface for the purpose of preventing scratches and dirt, and surface protective films for the purpose of preventing scratches and dirt that occur during processing and transporting processes. Yes.

  In the step of bonding the optical film, a separator and a surface protective film that are used for the purpose of protecting these optical films become unnecessary, and thus are peeled off from the optical film.

  Since these optical films, pressure-sensitive adhesives, separators, and surface protective films are made of a plastic material, they have high electrical insulation and generate static electricity during friction and peeling. Therefore, static electricity is generated when the separator and the surface protective film are peeled from the optical film. Static electricity is a big problem in the manufacturing process of liquid crystal displays and touch panels. Problems due to static electricity include dust adhering to the optical member, abnormal display due to disorder of liquid crystal alignment, and electrostatic breakdown of peripheral circuit elements. Therefore, various antistatic treatments are performed on the optical member in order to prevent such problems.

  For example, a method of forming a conductive layer of indium oxide / tin oxide on a polarizing plate by sputtering and performing an antistatic treatment is disclosed (for example, see Patent Document 1). In addition, a method of forming an antistatic layer made of an ultraviolet curable acrylic resin mixed with metal oxide particles on a polarizing plate is disclosed (for example, see Patent Document 2).

  However, these methods require a new process for forming the antistatic layer on the optical member, and the increase in the number of processes reduces productivity and increases cost. Accordingly, the polarizing plate provided with the antistatic layer has a problem that the cost is higher than that of a conventional polarizing plate not subjected to antistatic treatment.

  On the other hand, there is also known a polarizing member in which a light diffusion layer having antistatic ability is formed by adding an antistatic agent to the light diffusion layer (see, for example, Patent Document 3). It is used for diffusing light from the light, and is not widely used for optical members.

JP-A-6-51121 JP 2001-318230 A JP 2002-22960 A

  In light of such circumstances, the present invention provides an antistatic ability to a highly versatile pressure-sensitive adhesive layer, thereby making it possible to easily and inexpensively prevent an optical member from being generated when a separator or a surface protective film is peeled off. And it aims at providing the adhesive optical member which can fully maintain the adhesive force of an adhesive layer.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by using the following pressure-sensitive adhesive composition, and have completed the present invention.

  That is, the pressure-sensitive adhesive optical member of the present invention is a pressure-sensitive adhesive optical member in which a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive composition is formed on one side or both sides of the optical member. And a base polymer containing a polymer having a glass transition temperature Tg of 0 ° C. or lower. Here, the ionic liquid refers to a molten salt (ionic compound) that is liquid at room temperature (25 ° C.).

  According to the pressure-sensitive adhesive optical member of the present invention, by adding an antistatic function to the pressure-sensitive adhesive layer, it is possible to easily prevent the optical member from being charged without newly providing an antistatic layer, and to reduce the productivity without reducing productivity. Can be manufactured. By using the ionic liquid as an antistatic agent, a pressure-sensitive adhesive composition having a high antistatic effect can be obtained without impairing the adhesive properties. Although details of the reason why excellent antistatic properties can be obtained by using ionic liquids are not clear, molecular movement is easy because ionic liquids are liquid, and molecular rearrangement is likely to occur due to the generation of electric charges. Therefore, even if an ionic liquid is contained in the pressure-sensitive adhesive, a charge neutralization mechanism by molecular rearrangement works, so that an excellent antistatic ability can be obtained. In addition, 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. Further, since the ionic liquid has no vapor pressure (non-volatile), it has a characteristic that the antistatic property is continuously obtained without disappearing with time.

  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, the ionic liquid preferably contains one or more cations represented by the following general formulas (A) to (D). An ionic liquid having these cations provides a further excellent antistatic ability.

［式（Ａ）中のＲａは、炭素数４から２０の炭化水素基を表し、ヘテロ原子を含んでも良く、ＲｂおよびＲｃは、同一又は異なって、水素または炭素数１から１６の炭化水素基を表し、ヘテロ原子を含んでも良い。但し、窒素原子が２重結合を含む場合、Ｒｃはない。］
［式（Ｂ）中のＲｄは、炭素数２から２０の炭化水素基を表し、ヘテロ原子を含んでも良く、Ｒｅ、Ｒｆ、およびＲｇは、同一又は異なって、水素または炭素数１から１６の炭化水素基を表し、ヘテロ原子を含んでも良い。］
［式（Ｃ）中のＲｈは、炭素数２から２０の炭化水素基を表し、ヘテロ原子を含んでも良く、Ｒｉ、Ｒｊ、およびＲｋは、同一又は異なって、水素または炭素数１から１６の炭化水素基を表し、ヘテロ原子を含んでも良い。］
［式（Ｄ）中のＺは、窒素、硫黄、又はリン原子を表し、Ｒｌ、Ｒｍ、Ｒｎ、およびＲｏは、同一又は異なって、炭素数１から２０の炭化水素基を表し、ヘテロ原子を含んでも良い。但しＺが硫黄原子の場合、Ｒｏはない。］

[In the formula (A), Ra represents a hydrocarbon group having 4 to 20 carbon atoms and may contain a hetero atom, and Rb and Rc may be the same or different, and may be hydrogen or a hydrocarbon group having 1 to 16 carbon atoms. Represents a hetero atom. However, there is no Rc when the nitrogen atom contains a double bond. ]
[Rd in the formula (B) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a heteroatom, and Re, Rf, and Rg may be the same or different and each may represent hydrogen or 1 to 16 carbon atoms. It represents a hydrocarbon group and may contain a hetero atom. ]
[Rh in the formula (C) represents a hydrocarbon group having 2 to 20 carbon atoms, and may include a hetero atom, and Ri, Rj, and Rk may be the same or different and each may represent hydrogen or 1 to 16 carbon atoms. It represents a hydrocarbon group and may contain a hetero atom. ]
[Z in Formula (D) represents a nitrogen, sulfur, or phosphorus atom; Rl, Rm, Rn, and Ro are the same or different and each represents a hydrocarbon group having 1 to 20 carbon atoms; May be included. However, when Z is a sulfur atom, there is no Ro. ]

  In addition, the polymer having a glass transition temperature Tg of 0 ° C. or lower is preferably an acrylic polymer mainly composed of at least one of acrylate and / or methacrylate having an alkyl group having 1 to 14 carbon atoms. These acrylic polymers provide a good balance of compatibility with the ionic liquid and the base polymer, and can sufficiently maintain the adhesive properties.

  The adhesive optical member of the present invention is particularly effective when the optical member includes a polarizing plate, a retardation plate, a brightness enhancement plate, or an antiglare sheet.

Schematic configuration diagram of potential measurement unit used for measurement of peeling voltage in Examples etc.

  The pressure-sensitive adhesive optical member of the present invention comprises an ionic liquid and a polymer having a glass transition temperature Tg of 0 ° C. or lower as a base polymer. The ionic liquid refers to a molten salt (ionic compound) that is 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 is obtained. What consists of an organic cation component and an anion component is used preferably.

［式（Ａ）中のＲａは、炭素数４から２０の炭化水素基を表し、ヘテロ原子を含んでも良く、ＲｂおよびＲｃは、同一又は異なって、水素または炭素数１から１６の炭化水素基を表し、ヘテロ原子を含んでも良い。但し、窒素原子が２重結合を含む場合、Ｒｃはない。］
［式（Ｂ）中のＲｄは、炭素数２から２０の炭化水素基を表し、ヘテロ原子を含んでも良く、Ｒｅ、Ｒｆ、およびＲｇは、同一又は異なって、水素または炭素数１から１６の炭化水素基を表し、ヘテロ原子を含んでも良い。］
［式（Ｃ）中のＲｈは、炭素数２から２０の炭化水素基を表し、ヘテロ原子を含んでも良く、Ｒｉ、Ｒｊ、およびＲｋは、同一又は異なって、水素または炭素数１から１６の炭化水素基を表し、ヘテロ原子を含んでも良い。］
［式（Ｄ）中のＺは、窒素、硫黄、又はリン原子を表し、Ｒｌ、Ｒｍ、Ｒｎ、およびＲｏは、同一又は異なって、炭素数１から２０の炭化水素基を表し、ヘテロ原子を含んでも良い。但しＺが硫黄原子の場合、Ｒｏはない。］

[In the formula (A), Ra represents a hydrocarbon group having 4 to 20 carbon atoms and may contain a hetero atom, and Rb and Rc may be the same or different, and may be hydrogen or a hydrocarbon group having 1 to 16 carbon atoms. Represents a hetero atom. However, there is no Rc when the nitrogen atom contains a double bond. ]
[Rd in the formula (B) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a heteroatom, and Re, Rf, and Rg may be the same or different and each may represent hydrogen or 1 to 16 carbon atoms. It represents a hydrocarbon group and may contain a hetero atom. ]
[Rh in the formula (C) represents a hydrocarbon group having 2 to 20 carbon atoms, and may include a hetero atom, and Ri, Rj, and Rk may be the same or different and each may represent hydrogen or 1 to 16 carbon atoms. It represents a hydrocarbon group and may contain a hetero atom. ]
[Z in Formula (D) represents a nitrogen, sulfur, or phosphorus atom; Rl, Rm, Rn, and Ro are the same or different and each represents a hydrocarbon group having 1 to 20 carbon atoms; May be included. However, when 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-pyrroline cation, 1-ethyl-2-phenylindole cation, 1,2-dimethylindole cation, and 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-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium 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-dihydropyrimidinium cation And the like.

  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 those in which a part of the alkyl group is substituted with an alkenyl group, an alkoxyl group, or an epoxy group. Is mentioned.

  Specific examples include tetramethylammonium cation, tetraethylammonium cation, tetrabutylammonium cation, tetrahexylammonium cation, triethylmethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation, N, N-diethyl-N-methyl-N -(2-methoxyethyl) ammonium cation, glycidyltrimethylammonium cation, N, N-dimethyl-N, N-dipropylammonium cation, N, N-dimethyl-N, N-dihexylammonium cation, N, N-dipropyl- N, N-dihexylammonium cation, trimethylsulfonium cation, triethylsulfonium cation, tributylsulfonium cation, Silsulfonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, tetramethylphosphonium cation, tetraethylphosphonium cation, tetrabutylphosphonium cation, tetrahexylphosphonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation, trimethyldecyl Examples include phosphonium cations and diallyldimethylammonium cations.

  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-hexylammonium cation, N, N-dimethyl-N-ethyl-N-heptylammonium cation, N, N-dimethyl-N-ethyl-N-nonylammonium cation, N, N-dimethyl-N-propyl-N- Butylan Nium cation, N, N-dimethyl-N-propyl-N-pentylammonium cation, N, N-dimethyl-N-propyl-N-hexylammonium cation, N, N-dimethyl-N-propyl-N-heptylammonium cation N, N-dimethyl-N-butyl-N-hexylammonium cation, N, N-dimethyl-N-butyl-N-heptylammonium cation, N, N-dimethyl-N-pentyl-N-hexylammonium cation, trimethyl Heptylammonium cation, N, N-diethyl-N-methyl-N-propylammonium cation, N, N-diethyl-N-methyl-N-pentylammonium cation, N, N-diethyl-N-methyl-N-heptylammonium Cation, N, N-diethyl-N-propyl Pyr-N-pentylammonium 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-hexylammonium cation, N, N-dibutyl-N-methyl-N-pentylammonium cation, N, N-dibutyl-N- Asymmetric tetraalkylammonium such as methyl-N-hexylammonium cation, trioctylmethylammonium cation, N-methyl-N-ethyl-N-propyl-N-pentylammonium cation Asymmetric tetraalkylphosphonium cations such as trialkylsulfonium cations such as nium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation and dimethyldecylsulfonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation and trimethyldecylphosphonium cation are preferably used. .

On the other hand, the anion component is not particularly limited as long as it satisfies that it becomes an ionic liquid. For example, Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , NO ₃ ⁻ , CH ₃ COO ⁻ , CF ₃ COO ⁻ , CH ₃ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , NbF ₆ ⁻ , TaF ₆ ⁻ , F (HF) _n ⁻ , (CN) ₂ N ⁻ , C ₄ F ₉ SO ₃ ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , C ₃ F ₇ COO ⁻ , (CF ₃ SO ₂ ) (CF ₃ CO) N ^{− and the} like are used. Among these, an anion component containing a fluorine atom is particularly preferably used since an ionic compound having a low melting point can be obtained.

  Specific examples of the ionic liquid used in the present invention are appropriately selected from the combination of the cation component and the anion component, and include 1-butylpyridinium tetrafluoroborate, 1-butylpyridinium hexafluorophosphate, 1-butyl- 3-methylpyridinium tetrafluoroborate, 1-butyl-3-methylpyridinium trifluoromethanesulfonate, 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide, 1-butyl-3-methylpyridinium bis (pentafluoroethanesulfonyl) ) Imido, 1-hexylpyridinium tetrafluoroborate, 2-methyl-1-pyrroline tetrafluoroborate, 1-ethyl-2-phenylindole tetrafluoroborate, 1,2-dimethyli Dole tetrafluoroborate, 1-ethylcarbazole tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium trifluoroacetate, 1-ethyl-3-methylimidazolium heptafluorobutyrate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium perfluorobutanesulfonate, 1-ethyl-3-methylimidazolium di Cyanamide, 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 trifluoro Acetate, 1-butyl-3-methylimidazolium heptafluorobutyrate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium perfluorobutanesulfonate, 1-butyl-3-methylimidazole Bis (trifluoromethanesulfonyl) imide, 1-hexyl-3-methylimidazolium bromide, 1-hexyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium 1-hexyl-3-methylimidazolium 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, tetrahexylammonium bis (trifluoromethanesulfonyl) imide, diallyldimethylammonium tetrafluoroborate, diary Dimethylammonium trifluoromethanesulfonate, diallyldimethylammonium bis (trifluoromethanesulfonyl) imide, diallyldimethylammonium bis (pentafluoroethanesulfonyl) imide, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium tetrafluoro Borate, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium trifluoromethanesulfonate, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl) Imido, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium bis (pentafluoroethanesulfonyl) imide, glycidyltrimethylammonium trifluorometa Sulfonate, glycidyltrimethylammonium bis (trifluoromethanesulfonyl) imide, glycidyltrimethylammonium bis (pentafluoroethanesulfonyl) imide, 1-butylpyridinium (trifluoromethanesulfonyl) trifluoroacetamide, 1-butyl-3-methylpyridinium (trifluoromethanesulfonyl) ) Trifluoroacetamide, 1-ethyl-3-methylimidazolium (trifluoromethanesulfonyl) trifluoroacetamide, diallyldimethylammonium (trifluoromethanesulfonyl) trifluoroacetamide, glycidyltrimethylammonium (trifluoromethanesulfonyl) trifluoroacetamide, N, N -Dimethyl-N-ethyl-N-propylammonium bi (Trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-butylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-pentylammonium bis (trifluoromethanesulfonyl) Imido, N, N-dimethyl-N-ethyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N -Dimethyl-N-ethyl-N-nonylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N, N-dipropylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl- N-Butylone Ni-bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-hexylammonium bis (trifluoromethanesulfonyl) Imido, N, N-dimethyl-N-propyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-butyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N- Dimethyl-N-butyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-pentyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl- , N-dihexylammonium bis (trifluoromethanesulfonyl) imide, trimethylheptylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-propylammonium bis (trifluoromethanesulfonyl) imide, N, N- Diethyl-N-methyl-N-pentylammonium 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, triethylpentylammonium bis (trifluorometa Sulfonyl) 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-hexylammonium 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 (trifluoromethanes) Honiru) imide, trioctyl methyl ammonium bis (trifluoromethanesulfonyl) imide, etc. N- methyl -N- ethyl -N- propyl -N- pentyl ammonium bis (trifluoromethanesulfonyl) imide.

  A commercially available ionic liquid as described above may be used, but it can also be synthesized as follows. The method for synthesizing the ionic liquid is not particularly limited as long as the target ionic liquid is obtained. In general, the document “ionic liquids—the forefront and future of development” [CMC Publishing Co., Ltd.] A halide method, a hydroxide method, an acid ester method, a complex formation method, a neutralization method and the like as described in “Issuance” are used.

  The synthesis method of the halide method, hydroxide method, acid ester method, complex formation method, and neutralization method will be described below using a nitrogen-containing onium salt as an example. Other sulfur-containing onium salts, phosphorus-containing onium salts, etc. This ionic liquid can also be obtained by the same method.

The halide method is a method carried out by reactions as shown in the following formulas (1) to (3). First, a tertiary amine and an alkyl halide are reacted to obtain a halide. (Reaction Formula (1), chlorine, bromine and iodine are used as the halogen) Acid (HA) or salt (MA, M) having an anion structure (A ⁻ ) of the ionic liquid intended for the obtained halide Is reacted with a target anion such as ammonium, lithium, sodium, potassium, etc. to form a salt, and the target ionic liquid (R ₄ NA) is obtained.

The hydroxide method is a method performed by reactions as shown in (4) to (8). First, halide (R ₄ NX) is subjected to ion exchange membrane electrolysis (reaction formula (4)), OH type ion exchange resin method (reaction formula (5)) or reaction with silver oxide (Ag ₂ O) (reaction formula ( 6)) to obtain the hydroxide (R ₄ NOH). (Chlorine, bromine and iodine are used as the halogen) The obtained hydroxide is subjected to the reaction of the reaction formulas (7) to (8) in the same manner as in the halogenation method described above, and the desired ionic liquid (R ₄ NA) is obtained.

The acid ester method is a method performed by reactions as shown in (9) to (11). First, a tertiary amine (R ₃ N) is reacted with an acid ester to obtain an acid ester product. (Reaction formula (9), as the acid ester, an ester of an inorganic acid such as sulfuric acid, sulfurous acid, phosphoric acid, phosphorous acid or carbonic acid, or an organic acid such as methanesulfonic acid, methylphosphonic acid or formic acid) The target ionic liquid (R ₄ NA) is obtained by using the obtained acid ester product in the reactions of the reaction formulas (10) to (11) in the same manner as the halogenation method. Further, by using methyl trifluoromethanesulfonate, methyl trifluoroacetate or the like as the acid ester, an ionic liquid can be directly obtained.

The complex formation method is a method performed by reactions as shown in (12) to (15). First, a quaternary ammonium halide (R ₄ NX), a quaternary ammonium hydroxide (R ₄ NOH), a quaternary ammonium carbonate ester (R ₄ NOCO ₂ CH ₃ ) or the like is added to hydrogen fluoride (HF) or Reaction with ammonium fluoride (NH ₄ F) gives a quaternary ammonium fluoride salt. (Reaction formulas (12) to (14)) The obtained quaternary ammonium fluoride salt is subjected to a complex formation reaction with fluorides such as BF ₃ , AlF ₃ , PF ₅ , ASF ₅ , SbF ₅ , NbF ₅ , and TaF _5. An ionic liquid can be obtained. (Reaction Formula (15))

The neutralization method is a method performed by a reaction as shown in (16). Tertiary amine and HBF ₄ , HPF ₆ , CH ₃ COOH, CF ₃ COOH, CF ₃ SO ₃ H, (CF ₃ SO ₂ ) ₂ NH, (CF ₃ SO ₂ ) ₃ CH, (C ₂ F ₅ SO ₂ ) ₂ It can be obtained by reacting with an organic acid such as NH.

  R in 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 blending amount of the ionic liquid cannot be defined unconditionally because it varies depending on the compatibility of the acrylic polymer to be used and the ionic liquid, but is generally 0.01 to 100 parts by weight of the base polymer. 40 parts by weight is preferable, 0.03 to 20 parts by weight is more preferable, and 0.05 to 10 parts by weight is most preferable. If it is less than 0.01 part by weight, sufficient antistatic properties cannot be obtained, and if it exceeds 40 parts by weight, the 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., more preferably Tg is −80 to −10 ° C. When the glass transition temperature Tg exceeds 0 ° C., it is difficult to obtain a sufficient adhesive force even when an ionic liquid is contained.

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

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

  As an acrylic polymer mainly composed of one or more of acrylates and / or methacrylates having an alkyl group having 1 to 14 carbon atoms, acrylates having an alkyl group having 1 to 14 carbon atoms and / or Methacrylate {hereinafter referred to as (meth) acrylate. } An acrylic polymer having a weight average molecular weight of 100,000 or more, the main component of which is 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. (Meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (Meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate, and the like.

  As other components, the Tg is 0 ° C. or lower (usually −100 ° C. or higher) for the reason that it is easy to balance the adhesive performance, and the sulfonic acid group-containing monomer, phosphoric acid group-containing monomer, and cyano group-containing monomer are appropriately used. , Vinyl ester, aromatic vinyl compound and other cohesive strength / heat resistance improving components, carboxyl group-containing monomer, acid anhydride group-containing monomer, hydroxyl group-containing monomer, amide group-containing monomer, amino group-containing monomer, epoxy group-containing A component having a functional group that functions as an adhesive strength improvement or crosslinking base point, such as a monomer, N-acryloylmorpholine, and vinyl ethers, can be used. Other components 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 acrylic polymer so that the acid value is 29 or less. When the acid value of the acrylic polymer exceeds 29, the antistatic property tends to deteriorate.

  The adjustment of the acid value can be adjusted by the blending amount of the 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. However, in this case, the acid 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. And naphthalenesulfonic acid.

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

  As hydroxyl group-containing monomers, 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, 4 -Hydroxybutyl vinyl ether, diethylene glycol monovinyl ether and the like.

  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 can be obtained by a polymerization method generally used as a synthesis method of 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 crosslinking a base polymer, particularly an acrylic polymer. Specific means of the crosslinking method include compounds having a group capable of reacting with a carboxyl group, a hydroxyl group, an amino group, an amide group, etc., which are appropriately included in an acrylic polymer such as an isocyanate compound, an epoxy compound, or an aziridine compound as a crosslinking base point. There is a method of using a so-called cross-linking agent to add and react.

  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 mainly 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, and 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 amount Adduct (trade name Coronate HL), isocyanurate of hexamethylene diisocyanate (trade name Coronate HX) [any Such as Nippon Polyurethane Industry Co., Ltd.] isocyanate adducts and the like.

  Examples of the epoxy compound include N, N, N ′, N′-tetraglycidyl-m-xylenediamine (trade name: TETRAD-X) and 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane (trade name: TETRAD- C) [all manufactured by Mitsubishi Gas Chemical Co., Ltd.].

  These crosslinking agents are used alone or in a mixture of two or more. The amount of the crosslinking agent to be 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 optical member. In general, in order to obtain sufficient heat resistance by the cohesive strength of the acrylic pressure-sensitive adhesive, it is preferable to blend 0.01 parts by weight or more with respect to 100 parts by weight of the acrylic polymer. Moreover, it is preferable to mix | blend at 15 weight part or less with respect to 100 weight part of said acrylic polymers from the point of a softness | flexibility and adhesiveness.

  Moreover, it can also add as a polyfunctional monomer which has 2 or more of radiation reactive unsaturated bonds as a substantial crosslinking agent, and can also be bridge | crosslinked by radiation. The polyfunctional monomer having two or more radiation-reactive unsaturated bonds is one or more radiation reactions that can be crosslinked (cured) by irradiation with radiation such as vinyl, acryloyl, methacryloyl, and vinylbenzyl groups. A polyfunctional monomer component having two or more properties is used. In general, those having 10 or less radiation-reactive unsaturated bonds are preferably used. Two or more polyfunctional monomers can be used 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, 1,6 hexanediol di ( And (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, divinylbenzene, N, N′-methylenebisacrylamide and the like.

  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 general, in order to obtain sufficient heat resistance by the cohesive force of the acrylic pressure-sensitive adhesive, it is preferably blended at 0.1 to 30 parts by weight with respect to 100 parts by weight of the acrylic polymer. Moreover, it is more preferable to mix | blend at 10 weight part or less with respect to 100 weight part of acrylic polymers from the point of a softness | flexibility and adhesiveness.

  Examples of the radiation include ultraviolet rays, laser rays, α rays, β rays, γ rays, x rays, electron rays, and the like, and ultraviolet rays are preferably used from the viewpoints of controllability, good handleability, 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 lamp, or a chemical lamp. In addition, when using an ultraviolet-ray as a radiation, a photoinitiator is added to an acrylic adhesive.

  The photopolymerization initiator may be any substance that generates radicals or cations by irradiating ultraviolet rays having an appropriate wavelength that can trigger the polymerization reaction according to the type of the radiation-reactive component.

  Examples of radical photopolymerization initiators include benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether, o-benzoylbenzoic acid methyl-p-benzoin ethyl ether, benzoin isopropyl ether, α-methylbenzoin, 2,2-diethoxyacetophenone, acetophenones such as 1-hydroxycyclohexyl phenyl ketone, propio such as 2-hydroxy-2-methylpropiophenone, 2-hydroxy-4′-isopropyl-2-methylpropiophenone Benzophenones such as phenones, benzophenone, methylbenzophenone, p-chlorobenzophenone, p-dimethylaminobenzofuninone, 2-chlorothioxanthone, 2-ethylthio Thioxanthones such as sandone, 2-isopropylthioxanthone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)- Examples include acylphosphine oxides such as (ethoxy) -phenylphosphine oxide, benzyl, dibenzosuberone, and α-acyloxime ester.

  Examples of the cationic photopolymerization initiator include onium salts such as aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts, organometallic complexes such as iron-allene complexes, titanocene complexes, and arylsilanol-aluminum complexes, nitrobenzyl Examples thereof include esters, sulfonic acid derivatives, phosphoric acid esters, sulfonic acid derivatives, phosphoric acid esters, phenol sulfonic acid esters, diazonaphthoquinone, and N-hydroxyimide sulfonate. About the said photoinitiator, it is also possible to use 2 or more types together.

  The photopolymerization initiator is preferably blended in an amount of usually 0.1 to 10 parts by weight, preferably 0.2 to 7 parts by weight with respect to 100 parts by weight of the acrylic polymer.

  It is also possible to use a photoinitiated polymerization aid such as amines in combination. Examples of the photoinitiator include 2-dimethylaminoethyl benzoate, dimethylaminoacetophenone, p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamyl ester, and the like. Two or more photopolymerization initiation assistants can be used in combination. The polymerization initiation assistant is preferably blended in an amount of 0.05 to 10 parts by weight, more preferably 0.1 to 7 parts by weight, with respect to 100 parts by weight of the acrylic polymer.

  The pressure-sensitive adhesive composition of the present invention can 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 polyoxyethylene alkylamine, polyoxyethylene diamine, ethylene glycol group-containing acrylic polymer, ethylene oxide group-containing polyether polymer, ethylene oxide group-containing polymer. Examples include ether ester amides, ethylene oxide group-containing polyether amide imides, polyoxyethylene glycol fatty acid esters, polyoxysorbitan acid fatty acid esters, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl ethers, and the like.

  As a compounding quantity of an ethylene oxide group containing compound, it is 0.01-40 weight part with respect to 100 weight part of base polymers, Preferably it is 0.1 weight part-20 weight part. If the amount 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 adhesive optical member of the present invention includes various conventionally known tackifiers, surface lubricants, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, ultraviolet absorbers, and polymerization prohibitions. Additives according to the use of various conventionally known additives such as additives, silane coupling agents, inorganic or organic fillers, powders such as metal powders and pigments, particles, and foils. I can do it.

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

  As the method for forming and applying the pressure-sensitive adhesive layer, known methods used for the production of pressure-sensitive adhesive tapes are used. Specific examples include roll coating, gravure coating, reverse coating, roll brushing, spray coating, and air knife coating. .

  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 enhancement plate, or an antiglare sheet. The optical member is a laminate of two or more optical materials such as a laminate of a polarizing plate and a retardation plate, a laminate of retardation plates, a laminate of a polarizing plate and a brightness enhancement 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 polarizer is generally used.

  The polarizer is not particularly limited, and various types can be used. Examples of the polarizer include hydrophilic polymer films such as polyvinyl alcohol film, partially formalized polyvinyl alcohol film, and ethylene / vinyl acetate copolymer partially saponified film, and two colors such as iodine and dichroic dye. Examples thereof include polyene-based oriented films such as those obtained by adsorbing volatile substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic material such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is preferably 1 μm to 1 mm, more preferably 20 μm to 200 μm, taking into consideration the strength as a film and the uniformity during stretching.

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

  As a material for forming the transparent protective film provided on one side or both sides of the polarizer, a material excellent in transparency, mechanical strength, thermal stability, moisture shielding property, isotropy and the like is preferable. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene such as polystyrene and acrylonitrile / styrene copolymer (AS resin) -Based polymer, polycarbonate-based polymer and the like. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or the above 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 thermosetting or ultraviolet curable resin such as acrylic, urethane, acrylurethane, epoxy, and silicone.

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

  Although the thickness of a protective film can be determined suitably, generally it is about 1-500 micrometers from points, such as workability | operativity, such as intensity | strength and handleability, and thin layer property. 1-300 micrometers is especially preferable, and 5-200 micrometers is more preferable.

  Moreover, it is preferable that a protective film has as little color as possible. Therefore, Rth = [(nx + ny) / 2−nz] · d (where nx and ny are the main refractive index in the plane of the film, 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 film having a thickness direction retardation value (Rth) of −90 nm to +75 nm, the coloring (optical coloring) of the polarizing plate caused by 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 cellulose polymer such as triacetyl cellulose is preferable from the viewpoints of polarization characteristics and durability. A triacetyl cellulose film is particularly preferable. In addition, when providing a protective film in the both sides of a polarizer, the protective film which consists of the same polymer material may be used by the front and back, and the protective film which consists of a different polymer material etc. may be used. The polarizer and the protective film are usually in close contact with each other through an aqueous adhesive or the like. Examples of the water-based adhesive include an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex, a water-based polyurethane, and a water-based polyester.

  The surface of the transparent protective film to which the polarizer is not adhered may be subjected to a hard coat layer, an antireflection treatment, an antisticking treatment, or a treatment for diffusion or antiglare.

  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 with a cured film excellent in hardness, sliding properties, etc. by an appropriate ultraviolet curable resin such as acrylic or silicone is used. It can be formed by a method of adding to the surface of the film. The antireflection treatment is performed for the purpose of preventing 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 art. Further, the anti-sticking treatment is performed for the purpose of preventing adhesion with an adjacent layer.

  The anti-glare treatment is applied for the purpose of preventing the outside light from being reflected on the surface of the polarizing plate and obstructing the visibility of the light transmitted through the polarizing plate. For example, the surface is roughened by a sandblasting method or an embossing method. 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 blending method of transparent fine particles. The fine particles to be included in the formation of the surface fine concavo-convex structure are, for example, conductive materials made of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide or the like having an average particle diameter of 0.5 to 50 μm. In some cases, transparent fine particles such as inorganic fine particles, organic fine particles composed of a crosslinked or uncrosslinked polymer, and the like are used. When forming a surface fine uneven 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 uneven structure. The antiglare layer may also serve as a diffusion layer (viewing angle expanding function or the like) for diffusing the light transmitted through the polarizing plate to expand the viewing angle.

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

  For example, an antiglare layer is formed in a sheet shape or formed on a transparent substrate to form 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 as a sheet.

  Examples of the optical member of the present invention include a liquid crystal display device such as a reflection plate, a semi-transmission plate, a phase difference plate (including wavelength plates such as 1/2 and 1/4), a viewing angle compensation film, and a brightness enhancement film. What becomes an optical layer which may be used for formation is mention | raise | lifted. These can be used alone as the optical member of the present invention, and can be laminated on the polarizing plate for practical use and used in one or more layers.

  In particular, a reflective polarizing plate or a semi-transmissive polarizing plate in which a polarizing plate is further laminated with a reflecting plate or a semi-transmissive reflecting plate, an elliptical polarizing plate or a circular polarizing plate in which a retardation plate is further laminated on a polarizing plate, a polarizing plate A wide viewing angle polarizing plate in which a viewing angle compensation film is further laminated on a plate, or a polarizing plate in which a brightness enhancement film is further laminated on a polarizing plate is preferable.

  A reflective polarizing plate is a polarizing plate provided with a reflective layer, and is used to form a liquid crystal display device or the like that reflects incident light from the viewing side (display side). Such a light source can be omitted, and the liquid crystal display device can be easily thinned. 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 surface of the polarizing plate via a transparent protective layer or the like as necessary.

  Specific examples of the reflective polarizing plate include those in which a reflective layer is formed by attaching a foil or a vapor deposition film made of a reflective metal such as aluminum on one side of a transparent protective film matted as necessary. Moreover, the transparent protective film contains fine particles so as to have a surface fine concavo-convex structure and a reflective layer having a fine concavo-convex structure thereon. The reflective layer having the fine concavo-convex structure has an advantage that incident light is diffused by irregular reflection to prevent directivity and glaring appearance and to suppress unevenness in brightness and darkness. The transparent protective film containing fine particles also has an advantage that incident light and its reflected light are diffused when passing through it, and light and dark unevenness can be further suppressed. The reflective layer of the fine concavo-convex structure reflecting the surface fine concavo-convex structure of the transparent protective film is formed by transparent the metal by an appropriate method such as a vapor deposition method such as a vacuum vapor deposition method, an ion plating method, a sputtering method, or a plating method. It can be performed by a method of directly attaching to the surface of the protective layer.

  Instead of the method of directly applying the reflecting plate to the transparent protective film of the polarizing plate, the reflecting plate can be used as a reflecting sheet provided with a reflecting layer on an appropriate film according to the transparent film. Since the reflective layer is usually made of metal, the usage form in which the reflective surface is covered with a transparent protective film, a polarizing plate or the like is used to prevent the reflectance from being lowered due to oxidation, and thus to maintain the initial reflectance for a long time. In addition, it is more preferable to avoid a separate attachment of the protective layer.

  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 with the reflective layer. A transflective polarizing plate is usually provided on the back side of a liquid crystal cell, and displays an image by reflecting incident light from the viewing side (display side) when a liquid crystal display device is used in a relatively bright atmosphere. In a relatively dark atmosphere, a liquid crystal display device or the like that displays an image using a built-in light source such as a backlight built in the back side of the transflective polarizing plate can be formed. In other words, the transflective polarizing plate is useful for forming a liquid crystal display device of a type that can save energy of using a light source such as a backlight in a bright atmosphere and can be used with a built-in light source even in a relatively dark atmosphere. It is.

  An elliptically polarizing plate or a circularly polarizing plate in which a retardation plate is further laminated on a polarizing plate will be described. A phase difference 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 quarter-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 half-wave plate (also referred to as a λ / 2 plate) is usually used when changing the polarization direction of linearly polarized light.

  The elliptically polarizing plate is effectively used for black and white display without the above color by compensating (preventing) the coloration (blue or yellow) generated by the birefringence of the liquid crystal layer of the super twist nematic (STN) type liquid crystal display device. It is done. Further, the one in which the three-dimensional refractive index is controlled is preferable because it can compensate (prevent) coloring that occurs when the screen of the liquid crystal display device is viewed from an oblique direction. The circularly polarizing plate is effectively used, for example, when adjusting the color tone of an image of a reflective liquid crystal display device in which an image is displayed 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, a liquid crystal polymer alignment film, and a liquid crystal polymer alignment layer supported by a film. The thickness of the retardation plate is not particularly limited, but is generally about 20 to 150 μm.

  Examples of the polymer material include polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, polysulfone, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, Polyphenylene sulfide, polyphenylene oxide, polyallylsulfone, polyvinyl alcohol, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose polymer, norbornene resin, or binary, ternary various copolymers, graft copolymers Examples thereof include polymers and blends. These polymer materials become oriented products (stretched films) by stretching or the like.

  Examples of the liquid crystalline polymer include various main chain types and side chain types in which a conjugated linear atomic group (mesogen) imparting liquid crystal alignment is introduced into the main chain or side chain of the polymer. It is done. Specific examples of the main chain type liquid crystalline polymer include, for example, a nematic alignment polyester liquid crystalline polymer, a discotic polymer, and a cholesteric polymer having a structure in which a mesogen group is bonded to a spacer portion that imparts flexibility. . Specific examples of the side chain type liquid crystalline polymer include polysiloxane, polyacrylate, polymethacrylate, or polymalonate as a main chain skeleton, and a nematic alignment imparting paraffin through a spacer portion composed of a conjugated atomic group as a side chain. Examples thereof include those having a mesogen moiety composed of a substituted cyclic compound unit. These liquid crystalline polymers are prepared by, for example, applying a solution of a liquid crystalline polymer on an alignment surface such as those obtained by rubbing the surface of a thin film such as polyimide or polyvinyl alcohol formed on a glass plate, or by obliquely depositing silicon oxide. This is done by developing and heat treatment.

  The retardation plate may have an appropriate retardation according to the purpose of use, such as those for the purpose of compensating for various wavelength plates or birefringence of the liquid crystal layer, viewing angle, and the like. What laminated | stacked the phase difference plate and controlled optical characteristics, such as phase difference, etc. may be used.

  The elliptical polarizing plate and the 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 elliptically polarizing plate or the like can also be formed by sequentially laminating them sequentially in the manufacturing process of the liquid crystal display device so as to be a combination of a (reflective) polarizing plate and a retardation plate. An optical member such as a polarizing plate has an advantage that it can improve the production efficiency of a liquid crystal display device and the like because of excellent quality stability and lamination workability.

  The viewing angle compensation film is a film for widening the viewing angle so that an image can be seen relatively clearly even when the screen of the liquid crystal display device is viewed from a slightly oblique direction rather than perpendicular to the screen. As such a viewing angle compensation phase difference plate, for example, a phase difference plate, an alignment film such as a liquid crystal polymer, or an alignment layer such as a liquid crystal polymer supported on a transparent substrate is used. A normal retardation plate uses a birefringent polymer film uniaxially stretched in the plane direction, whereas a retardation plate used as a viewing angle compensation film stretches biaxially in the plane direction. Birefringent polymer film, biaxially stretched film such as polymer with birefringence with a controlled refractive index in the thickness direction that is uniaxially stretched in the plane direction and stretched in the thickness direction, etc. Used. Examples of the inclined alignment film include a film obtained by bonding a heat shrink film to a polymer film and stretching or / and shrinking the polymer film under the action of the contraction force by heating, and a film obtained by obliquely aligning a liquid crystal polymer. Can be mentioned. The raw material polymer for the phase difference plate is the same as the polymer described in the previous phase difference plate, preventing coloration due to a change in the viewing angle based on the phase difference by the liquid crystal cell and expanding the viewing angle for good visual recognition. An appropriate one for the purpose can be used.

  Also, from the viewpoint of achieving a wide viewing angle with good visibility, an optically compensated phase difference in which a liquid crystal polymer alignment layer, in particular an optically anisotropic layer composed of a discotic liquid crystal polymer gradient alignment layer, is supported by a triacetylcellulose film. A plate can be preferably used.

  A polarizing plate obtained by bonding a polarizing plate and a brightness enhancement film is usually provided on the back side of a liquid crystal cell. The brightness enhancement film reflects a linearly polarized light with a predetermined polarization axis or a circularly polarized light in a predetermined direction when natural light is incident due to a backlight such as a liquid crystal display device or reflection from the back side, and transmits other light. In addition, a polarizing plate in which a brightness enhancement film is laminated with a polarizing plate allows light from a light source such as a backlight to enter to obtain transmitted light in a predetermined polarization state, and reflects light without transmitting the light other than the predetermined polarization state. The The light reflected on the surface of the brightness enhancement film is further inverted through a reflective layer or the like provided behind the brightness enhancement film and re-incident on the brightness enhancement film, and part or all of the light is transmitted as light having a predetermined polarization state. Luminance can be improved by increasing the amount of light transmitted through the enhancement film and increasing the amount of light that can be used for liquid crystal display image display or the like by supplying polarized light that is difficult to be absorbed by the polarizer. That is, when light is incident through the polarizer from the back side of the liquid crystal cell without using a brightness enhancement film, light having a polarization direction that does not coincide with the polarization axis of the polarizer is almost polarized. It is absorbed by the polarizer and does not pass through the polarizer. That is, although depending on the characteristics of the polarizer used, approximately 50% of the light is absorbed by the polarizer, and the amount of light that can be used for liquid crystal image display or the like is reduced accordingly, resulting in a dark image. The brightness enhancement film allows light having a polarization direction that is absorbed by the polarizer to be reflected once by the brightness enhancement film without being incident on the polarizer, and further inverted through a reflective layer provided on the rear side thereof. Repeatedly re-enter the brightness enhancement film, and the brightness enhancement film transmits only polarized light whose polarization direction is such that the polarization direction of light reflected and inverted between the two can pass through the polarizer. Therefore, light such as a backlight can be efficiently used for displaying an image on the liquid crystal display device, and the screen can be brightened.

  A diffusion plate may be provided between the brightness enhancement film and the reflective layer. The polarized light reflected by the brightness enhancement film is directed to the reflective layer or the like, but the installed diffuser plate uniformly diffuses the light passing therethrough and simultaneously cancels the polarized state and becomes a non-polarized state. That is, the diffuser plate returns the polarized light to the original natural light state. The light in the non-polarized state, that is, the natural light state is directed toward the reflection layer and the like, reflected through the reflection layer and the like, and again passes through the diffusion plate and reenters the brightness enhancement film. Thus, while maintaining the brightness of the display screen by providing a diffuser plate that returns polarized light to the original natural light state between the brightness enhancement film and the reflective layer, etc., the brightness unevenness of the display screen is reduced at the same time, A uniform and bright screen can be provided. By providing such a diffuser plate, it is considered that the first incident light has a moderate increase in the number of repetitions of reflection, and in combination with the diffusion function of the diffuser plate, a uniform bright display screen can be provided.

  The brightness enhancement film has a characteristic of transmitting linearly polarized light having a predetermined polarization axis and reflecting other light, such as a multilayer thin film of dielectric material or a multilayer laminate of thin film films having different refractive index anisotropies. Such as an alignment film of a cholesteric liquid crystal polymer or an alignment liquid crystal layer supported on a film substrate, which reflects either left-handed or right-handed circularly polarized light and transmits other light. Appropriate things such as a thing can be used.

  Therefore, in the brightness enhancement film of the type that transmits linearly polarized light having the predetermined polarization axis as described above, the transmitted light is incident on the polarizing plate with the polarization axis aligned as it is, thereby efficiently transmitting while suppressing absorption loss due to the polarizing plate. Can be made. On the other hand, in a brightness enhancement film of a type that emits circularly polarized light such as a cholesteric liquid crystal layer, it can be incident on a polarizer as it is, but from the viewpoint of suppressing absorption loss, the circularly polarized light is linearly polarized through a retardation plate. It is preferable to make it enter into a polarizing plate. Note that circularly polarized light can be converted to linearly polarized light by using a quarter wave plate as the retardation plate.

  A retardation plate that functions as a quarter-wave plate in a wide wavelength range such as a visible light region exhibits, for example, a retardation layer that functions as a quarter-wave plate for light-color light having a wavelength of 550 nm and other retardation characteristics. It can be obtained by a method of superposing a retardation layer, for example, a retardation layer functioning as a half-wave plate. Therefore, the retardation plate disposed between the polarizing plate and the brightness enhancement film may be composed of one or more retardation layers.

  In addition, the cholesteric liquid crystal layer can also be obtained by reflecting circularly polarized light in a wide wavelength range such as a visible light region by combining two or more layers having different reflection wavelengths and having an overlapping structure. Based on this, transmitted circularly polarized light 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-described polarization separation type polarizing plate. Therefore, a reflective elliptical polarizing plate or a semi-transmissive elliptical polarizing plate in which the above-mentioned reflective polarizing plate or transflective polarizing plate and a retardation plate are combined may be used.

  The optical member in which the optical layer is laminated on the polarizing plate can be formed by a method of sequentially laminating separately in the manufacturing process of a liquid crystal display device or the like. There is an advantage that the manufacturing process of the liquid crystal display device and the like can be improved. For the lamination, an appropriate adhesive means such as an adhesive layer can be used. When adhering the polarizing plate and the other optical layer, their optical axes can be set at an appropriate arrangement angle in accordance with the target phase difference characteristic.

  In addition, each layer such as an optical member or an adhesive layer of the pressure-sensitive adhesive optical member of the present invention includes, for example, ultraviolet rays such as a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, a cyanoacrylate compound, and a nickel complex compound. What gave the ultraviolet absorptivity by systems, such as a system processed with an absorber, may be used.

  The pressure-sensitive 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 according to the conventional method. That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell, an adhesive optical member, and an illumination system as necessary, and incorporating a drive circuit. There is no particular limitation except that an optical member is used. As the liquid crystal cell, any type such as a TN type, an STN type, or a π type can be used.

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

  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 sequentially laminated on a transparent substrate to form a light emitter (organic electroluminescent light emitter). 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 and the like and a light emitting layer made of a fluorescent organic solid such as anthracene, Alternatively, a structure having various combinations such as a laminate of such a light emitting layer and an electron injection layer composed of a perylene derivative or the like, or a laminate of these hole injection layer, light emitting layer, and electron injection layer is known. It has been.

  In organic EL display devices, 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 recombination of these holes and electrons excites the phosphor material. Then, light is emitted on the principle that the excited fluorescent material emits light when returning to the ground state. The mechanism of recombination in the middle is the same as that of a general diode, and as can be predicted from this, the current and the emission intensity show strong nonlinearity with rectification with respect to the applied voltage.

  In an organic EL display device, in order to extract light emitted from the organic light emitting layer, at least one of the electrodes must be transparent, 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 material having a small work function for the cathode, and usually metal electrodes such as Mg—Ag and Al—Li are used.

  In the organic EL display device having such a configuration, the organic light emitting layer is formed of a very thin film having a thickness of about 10 nm. For this reason, the organic light emitting layer transmits light almost completely like the transparent electrode. As a result, light that is incident from the surface of the transparent substrate at the time of non-light emission, passes through the transparent electrode and the organic light emitting layer, and is reflected by the metal electrode is again emitted to the surface side of the transparent substrate. The display surface of the organic EL display device looks like a mirror surface.

  In an organic EL display device comprising an organic electroluminescent light emitting device comprising a transparent electrode on the surface side of an organic light emitting layer that emits light upon application of a voltage and a metal electrode on the back side of the organic light emitting layer, the surface of the transparent electrode While providing a polarizing plate on the side, a retardation plate can be provided between the transparent electrode and the polarizing plate.

  Since the retardation plate and the polarizing plate have a function of polarizing 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 visually recognized by the polarization action. In particular, the mirror surface of the metal electrode can be completely shielded by configuring the retardation plate with a quarter-wave plate and adjusting the angle formed by the polarization direction of the polarizing plate and the retardation plate to π / 4. .

  That is, only the linearly polarized light component of the external light incident on the organic EL display device is transmitted by the polarizing plate. This linearly polarized light becomes generally elliptically polarized light by the phase difference plate, but becomes circularly polarized light particularly when the phase difference plate is a quarter wavelength plate and the angle formed by the polarization direction of the polarizing plate and the phase difference plate is π / 4. .

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

  In the pressure-sensitive adhesive optical member of the present invention, a separator can be bonded to the pressure-sensitive adhesive surface for the purpose of protecting the pressure-sensitive adhesive surface as necessary. As a base material constituting the separator, there are paper and plastic film, but a plastic film is preferably used from the viewpoint of excellent surface smoothness.

  The film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer. For example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, 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 adhesive layer bonding surface of the film is appropriately treated with a release agent such as a silicone, fluorine, long chain alkyl or fatty acid amide release agent, silica powder or the like.

  The pressure-sensitive adhesive optical member of the present invention is preferably used for manufacturing various display devices such as liquid crystal display devices and touch panels. Note that an optical material such as a polarizing plate, a retardation plate, a brightness enhancement plate, and an antiglare sheet forming the optical member can be provided with an ultraviolet absorbing ability by using an ultraviolet absorber or the like. Examples of the ultraviolet absorber include salicylic acid ester compounds, benzophenone compounds, benzotriazole compounds, cyanoacrylate compounds, nickel complex compounds, and the like.

  Examples and the like specifically showing the configuration and effects of the present invention will be described below. In addition, the evaluation item in an Example etc. measured as follows.

[Acid value]
The acid value was measured using an automatic titrator COM-550 manufactured by Hiranuma Sangyo Co., Ltd., and obtained from the following formula.
A = {(Y−X) × f × 5.611} / MA; acid value,
Y; titration volume of sample solution (ml),
X: titration amount (ml) of a solution containing only 50 g of a mixed solvent,
f; factor of the 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 obtain a sample solution.
Titration solution: 0.1N, 2-propanolic 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 number test 1.

[Molecular weight]
The molecular weight was measured by using a GPC device manufactured by Tosoh Corporation, HLC-8220 GPC, and obtained as a converted value of polystyrene. The measurement conditions are as follows.
Sample concentration: 0.2 wt% (THF solution)
Sample injection volume: 10 μl,
Eluent: THF,
Flow rate: 0.6 ml / min,
Measurement temperature: 40 ° C.
Column: sample column; TSKguardcolumn SuperHZ-H1 + TSKgel SuperHZM-H2; reference column; TSKgel SuperH-RC1
Detector: differential refractometer.

[Glass-transition temperature]
The glass transition temperature Tg (° C.) was determined by the following formula using the following literature values as the glass transition temperature Tgn (° C.) of the homopolymer of each monomer.
Formula: 1 / (Tg + 273) = Σ [Wn / (Tgn + 273)]
[Wherein, 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 of each monomer, and n is the type of each monomer Represents. ]
2-ethylhexyl acrylate: -70 ° C
2-hydroxyethyl acrylate: -15 ° C
Butyl acrylate: -55 ° C
Acrylic acid: 106 ° C
Diethylacrylamide: 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 obtain Tg = An acrylic polymer solution (40% by weight) 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 allowed to react at 65 ° C. for 6 hours in a nitrogen stream. = -54 ° C., a weight-average molecular weight of 540,000, and an acrylic polymer solution having an acid value of 0 (25% by weight) was obtained.

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 in a nitrogen stream at 65 ° C. for 6 hours to produce Tg. = -49 ° C, an acrylic polymer solution (40% by weight) having a weight average molecular weight of 560,000 and an acid value of 15 was obtained.

Production Example 4
(Polarizer)
A polyvinyl alcohol film having a polymerization degree of 1700 and a thickness of 80 μm was swollen in a warm water bath at 30 ° C. for 1 minute, and then an iodine concentration 0.3 wt% aqueous solution (30% of iodine and potassium iodide (weight ratio = 1: 10)) (30 The film was stretched about 3 times in a 4% by weight boric acid aqueous solution at 50 ° C. so that the total stretch 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 surfaces of this polarizer using an adhesive composed of a 7% by weight aqueous polyvinyl alcohol solution. The saponification treatment was performed by immersing in a 60 ° C. aqueous sodium hydroxide solution (10 wt%) for 1 minute.

Example 1
(Preparation of adhesive composition)
1. A solution (40% by weight) of the acrylic polymer A obtained in Production Example 1 was diluted to 20% by weight with ethyl acetate, and glycidyltrimethylammonium trifluoromethanesulfonate (liquid at 25 ° C.) as an ionic liquid was added to 100 g of this solution. 0 g of trimethylolpropane / tolylene diisocyanate trimer adduct (trade name Coronate L) (0.13 g) was added to prepare an acrylic pressure-sensitive adhesive solution.

(Preparation of adhesive optical member)
The acrylic pressure-sensitive adhesive solution was applied to a silicone-treated surface of a 38 μm-thick polyethylene terephthalate film subjected to silicone treatment, 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 produce a pressure-sensitive adhesive optical member.

Example 2
(Preparation of adhesive composition)
The acrylic polymer B solution (25 wt%) obtained in Production Example 2 was diluted to 20 wt% with ethyl acetate, and 100 g of this solution was diluted with 1-butyl-3-methylpyridinium trifluoromethanesulfonate (25 ° C.) as an ionic liquid. And 0.23 g of trimethylolpropane / tolylene diisocyanate trimer adduct (trade name Coronate L) was added to prepare an acrylic pressure-sensitive adhesive solution.

(Preparation of adhesive optical member)
A pressure-sensitive adhesive 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 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 2.0 g of diallyldimethylammonium trifluoromethanesulfonate (liquid at 25 ° C.) was added to 100 g of this solution as an ionic liquid. Then, 0.13 g of trimethylolpropane / tolylene diisocyanate trimer adduct (trade name Golonate L) was added to prepare an acrylic pressure-sensitive adhesive solution.

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

(Preparation of adhesive optical member)
The acrylic pressure-sensitive adhesive solution was applied to a silicone-treated surface of a 38 μm-thick polyethylene terephthalate film subjected to silicone treatment, 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 produce a pressure-sensitive adhesive optical member.

Example 5
(Preparation of adhesive composition)
The acrylic polymer B solution (25% by weight) obtained in Production Example 2 was diluted to 20% by weight with ethyl acetate, and 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) as an ionic liquid was added to 100 g of this solution. 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).

(Preparation of adhesive optical member)
A pressure-sensitive adhesive 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 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 (liquid at 25 ° C.) was added to 100 g of this solution as an ionic liquid. ) 2.0 g, 0.13 g of trimethylolpropane / tolylene diisocyanate trimer adduct (trade name Golonate L) was added to prepare an acrylic pressure-sensitive adhesive solution.

(Preparation of adhesive optical member)
An 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.

Comparative Example 1
An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 1 except that no ionic liquid was 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 2
An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 2 except that no ionic liquid was 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 no ionic liquid was used. An 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.

  About the optical member obtained in said Examples 1-6 and Comparative Examples 1-3, the peeling band voltage and the adhesive force were confirmed in the following ways.

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

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

Production Example 7
(Preparation of protective film)
The acrylic pressure-sensitive adhesive solution was applied to the surface opposite to the antistatic surface of the antistatically treated polyethylene terephthalate film obtained in Production Example 5, heated at 110 ° C. for 3 minutes, and a pressure-sensitive adhesive layer having a thickness of 20 μm. Formed. Next, a silicone-treated surface of a polyethylene terephthalate film having a thickness of 25 μm, which was subjected to silicone treatment on one surface, was bonded to the surface of the pressure-sensitive adhesive layer to prepare a protective film.

[Peeling voltage]
After peeling the adhesive optical member separator cut to a size of 70 mm in width and 100 mm in length, it was attached to an acrylic plate with a thickness of 1 mm, a width of 70 mm, and a length of 100 mm that had been previously neutralized with a hand roller. The body was made. The protective film obtained in Production Example 7 was cut to a size of 70 mm in width and 130 mm in length, the separator was peeled off, and then one end protruded 30 mm from the polarizing plate surface of the adherend previously discharged. Crimp with a hand roller. After being left for one day in an environment of 23 ° C. × 50% RH, a sample is set at a predetermined position as shown below. One end that protrudes 30 mm is fixed to an automatic winder, and is peeled off at a peeling angle of 150 ° and a peeling speed of 10 m / min. The potential of the polarizing plate surface generated at this time was measured with a potential measuring device [KSD-0103, manufactured by Kasuga Denki Co., Ltd.] fixed at a predetermined position. The measurement was performed in an environment of 23 ° C. × 50% RH.

[Adhesion measurement]
After peeling the separator of the adhesive optical member cut to a width of 25 mm and a length of 100 mm, 0.25 MPa is applied to a slide glass (Matsunami Glass Industrial Co., Ltd., water edge polish) having a thickness of 1.3 mm, a width of 65 mm, and a length of 165 mm. An evaluation sample was prepared by laminating at the pressure of After leaving the laminate for 30 minutes, 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 results are shown in Table 1.

  As is clear from the results in Table 1 above, the adhesive band members of Examples 1 to 6 of the present invention have suppressed stripping voltage compared to Comparative Examples 1 to 3. Moreover, as for the adhesive optical member of Examples 1-6 of this invention, all have shown the adhesive force equivalent to Comparative Examples 1-3. Therefore, it turns out that the adhesive optical member of Examples 1-6 is an adhesive optical member excellent in antistatic property and an adhesive characteristic.

Claims (5)

In the pressure-sensitive adhesive optical member for image display device in which the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition is formed on one side or both sides of the optical member for image display device,
The pressure-sensitive adhesive composition, ionic liquids, ethylene oxide group-containing compound, and Ri Na glass transition temperature Tg contain 0 ℃ following polymers as a base polymer,
The ionic liquid is a molten salt that exhibits a liquid state at room temperature (25 ° C.),
The ethylene oxide group-containing compound is polyoxyethylene alkylamine, polyoxyethylene diamine, ethylene glycol group-containing acrylic polymer, ethylene oxide group-containing polyether polymer, ethylene oxide group-containing polyether ester amide, ethylene oxide group-containing polyether amide imide, polyoxyethylene glycol fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl phenyl ethers, and, for an image display device and at least Tanedea wherein Rukoto selected from the group consisting of polyoxyethylene alkyl ether pressure-sensitive Mold optical member.   The pressure-sensitive adhesive optical member for an image display device according to claim 1, wherein the ionic liquid is at least one of a nitrogen-containing onium salt, a sulfur-containing onium salt, and a phosphorus-containing onium salt. The pressure-sensitive adhesive optical member for an image display device according to claim 1, wherein the ionic liquid contains one or more cations represented by the following general formulas (A) to (D).

[In the formula (A), Ra represents a hydrocarbon group having 4 to 20 carbon atoms and may contain a hetero atom, and Rb and Rc may be the same or different, and may be hydrogen or a hydrocarbon group having 1 to 16 carbon atoms. Represents a hetero atom. However, there is no Rc when the nitrogen atom contains a double bond. ]
[Rd in the formula (B) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a heteroatom, and Re, Rf, and Rg may be the same or different and each may represent hydrogen or 1 to 16 carbon atoms. It represents a hydrocarbon group and may contain a hetero atom. ]
[Rh in the formula (C) represents a hydrocarbon group having 2 to 20 carbon atoms, and may include a hetero atom, and Ri, Rj, and Rk may be the same or different and each may represent hydrogen or 1 to 16 carbon atoms. It represents a hydrocarbon group and may contain a hetero atom. ]
[Z in Formula (D) represents a nitrogen, sulfur, or phosphorus atom; Rl, Rm, Rn, and Ro are the same or different and each represents a hydrocarbon group having 1 to 20 carbon atoms; May be included. However, when Z is a sulfur atom, there is no Ro. ]   The polymer having a glass transition temperature Tg of 0 ° C or lower is an acrylic polymer mainly comprising at least one of acrylate and / or methacrylate having an alkyl group having 1 to 14 carbon atoms. 2. An adhesive optical member for an image display device according to 1.   The image display device according to claim 1, wherein the optical member for an image display device is a laminate of at least one optical film of a polarizing plate, a retardation plate, a brightness enhancement plate, or an antiglare sheet. Adhesive optical member.

Images