JP4404370B2 - Adhesive composition, adhesive sheet and surface protective film - Google Patents

Description

  The present invention relates to an antistatic pressure-sensitive adhesive composition, and an antistatic pressure-sensitive adhesive sheet and a surface protective film which are formed into a sheet form or a tape form using the same.

  The pressure-sensitive adhesive sheet made of the antistatic pressure-sensitive adhesive composition of the present invention is suitably used for plastic products and the like that easily generate static electricity. In particular, it is useful as an antistatic pressure-sensitive adhesive sheet and a surface protective film used in applications that dislike static electricity such as electronic devices.

  The surface protective film is generally used for the purpose of sticking to a body to be protected through an adhesive applied to the side of the protective film and preventing scratches and dirt generated during processing and transportation of the body to be protected. For example, a panel of a liquid crystal display is formed by bonding an optical member such as a polarizing plate or a wavelength plate to a liquid crystal cell via an adhesive. In these optical members to be bonded to the liquid crystal cell, a protective film is bonded via an adhesive for the purpose of preventing scratches and dirt.

  Then, the protective film is peeled off and removed at a stage where the protective film is no longer necessary, for example, by bonding the optical member to the liquid crystal cell. In general, since a protective film and an optical member are made of a plastic material, they have high electrical insulation and generate static electricity during friction and peeling. Accordingly, static electricity is generated when the protective film is peeled off from the optical member such as a polarizing plate. When a voltage is applied to the liquid crystal while static electricity remains, the alignment of liquid crystal molecules is lost or the panel is damaged. Therefore, in order to prevent such problems, the surface protective film is subjected to various antistatic treatments.

  For example, a method is disclosed in which one or more surfactants are added to an adhesive and the surfactant is transferred from the adhesive to an adherend to prevent electrification (see, for example, Patent Document 1). However, in the present invention, the surfactant is easily bleed on the pressure-sensitive adhesive surface, and when applied to a protective film, there is a concern about contamination of the adherend. Therefore, when a pressure-sensitive adhesive to which a low molecular surfactant is added is applied to the protective film for an optical member, it is difficult to develop sufficient antistatic properties without impairing the optical properties of the optical member.

  Further, a method is disclosed in which an antistatic agent comprising a polyether polyol and an alkali metal salt is added to an acrylic pressure-sensitive adhesive to suppress bleeding of the antistatic agent on the surface of the pressure-sensitive adhesive (for example, see Patent Document 2). . However, even in this method, bleeding of the antistatic agent is unavoidable, and as a result, when applied to a surface protective film, if the treatment is performed over time or under high temperature, the adherend is contaminated by the bleeding phenomenon. Will occur.

  Furthermore, as a method for improving the above-mentioned contamination, a method for imparting antistatic properties to the base polymer itself of the pressure-sensitive adhesive composition has been disclosed (for example, see Patent Document 3). This disclosure includes a pressure-sensitive adhesive composition comprising a (meth) acrylic polymer containing a reactive surfactant. However, even in this method, there is no significant effect on suppressing the stripping voltage on the adherend side that is not antistatic, and as a result, reducing contamination and suppressing the stripping voltage on the adherend side that is not antistatic. Coexistence with was found to be difficult.

JP-A-9-165460 JP-A-6-128539 JP-A-9-208910

  In light of such circumstances, the present invention is a pressure-sensitive adhesive composition excellent in adhesion reliability, capable of preventing electrification at the time of peeling of an uncharged adherend, reducing contamination on the adherend, and An object is to provide an antistatic pressure-sensitive adhesive sheet and a surface protective film using the same.

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

  That is, the pressure-sensitive adhesive composition of the present invention comprises a (meth) acrylic polymer having 0.01 to 20% by weight of a reactive surfactant as a monomer unit, and an ionic liquid. To do.

  According to the pressure-sensitive adhesive composition of the present invention, as shown in the results of Examples, the base polymer is a (meth) acrylic polymer having 0.01 to 20% by weight of a reactive surfactant as a monomer unit, Since it contains an ionic liquid, the pressure-sensitive adhesive layer cross-linked with this reduces the contamination of the object to be protected, and provides antistatic properties when peeled, especially antistatic properties of non-antistatic adherends. It will be excellent. Although the details of the reason why the cross-linked product of the polymer and the ionic liquid exhibits such characteristics are not clear, the ionic liquid is coordinated with the ester group and / or ether group of the reactive surfactant. Is less likely to bleed, and is presumed to have achieved excellent antistatic properties and low contamination in parallel.

  In addition, the ionic liquid in this invention means the molten salt (ionic compound) which exhibits a liquid state at 25 degreeC.

  Moreover, the reactive surfactant in this invention means what has a reactive unsaturated bond.

  The pressure-sensitive adhesive composition of the present invention uses the above ionic liquid as an antistatic agent, and suppresses bleeding of the antistatic agent, and has excellent adhesion reliability to an adherend even over time or at high temperatures. It becomes. Although the reason why bleeding is suppressed by using an ionic liquid is not clear, it is presumed that the compatibility with the base polymer is higher than that of a surfactant or the like. Further, since the ionic liquid exhibits excellent conductivity by itself, a sufficient antistatic ability can be obtained even if the surface of the adherend is contaminated in a small amount.

  In addition, since the above ionic liquid is preferably in a liquid state at room temperature, it can be easily added and dispersed or dissolved in the pressure-sensitive adhesive as compared with a solid salt. Furthermore, since the ionic liquid has no vapor pressure (non-volatile), it does not disappear over time, and the antistatic property can be continuously obtained.

  In the pressure-sensitive adhesive composition of the present invention, a (meth) acrylic polymer having 0.01 to 20% by weight of a reactive surfactant as a monomer unit is used as a base polymer.

  The (meth) acrylic polymer in the present invention refers to an acrylic polymer and / or a methacrylic polymer. In addition, alkyl (meth) acrylate refers to alkyl acrylate and / or alkyl methacrylate, and (meth) acrylate refers to acrylate and / or methacrylate.

  In the above, the ionic liquid is preferably 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.

[R _a in the formula (A) represents a hydrocarbon group having 4 to 20 carbon atoms and may include a hetero atom, and R _b and R _c may be the same or different, and may be hydrogen or _C 1 to _C 16. Represents a hydrocarbon group and may contain heteroatoms. However, when the nitrogen atom contains a double bond, there is no R _c . ]
[R _d in the formula (B) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a hetero atom, and R _e , R _f , and R _g are the same or different and represent hydrogen or carbon number. Represents 1 to 16 hydrocarbon groups and may contain heteroatoms. ]
[R _h in the formula (C) represents a hydrocarbon group having 2 to 20 carbon atoms, and may contain a hetero atom, and R _i , R _j , and R _k may be the same or different and represent hydrogen or carbon number. Represents 1 to 16 hydrocarbon groups and may contain heteroatoms. ]
[Z in Formula (D) represents a nitrogen, sulfur, or phosphorus atom, and R ₁ , R _m , R _n , and R _o are the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms. And may contain heteroatoms. However, when Z is a sulfur atom, there is no _Ro . ]

  Furthermore, the reactive surfactant preferably contains an ethylene oxide group. By using a reactive surfactant containing an ethylene oxide group, the pressure-sensitive adhesive composition is further excellent in low contamination.

  Although the details of the reason why such a characteristic is exhibited by using the reactive surfactant containing the ethylene oxide group are not clear, the ether group of the reactive surfactant is more strongly distributed in the ionic liquid than the ester group. It is presumed that the bleed of the ionic liquid is suppressed by positioning.

  On the other hand, the pressure-sensitive adhesive layer of the present invention is formed by crosslinking the pressure-sensitive adhesive composition described above. A pressure-sensitive adhesive sheet having more excellent heat resistance and weather resistance can be obtained by appropriately adjusting the structural unit, the structural ratio, the selection and addition ratio of the crosslinking agent, etc. of the (meth) acrylic polymer.

  The pressure-sensitive adhesive sheet of the present invention is characterized in that a pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition described above is formed on a support. According to the pressure-sensitive adhesive sheet of the present invention, since the pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition exhibiting the above-described effects is provided, it is possible to prevent charging to an adherend that is not antistatic when peeled off. Thus, the pressure-sensitive adhesive sheet is excellent in adhesion reliability with reduced contamination to the adherend.

  In addition, the adhesive sheet in this invention includes other forms of sheet forms, such as an adhesive tape and an adhesive film.

  Furthermore, when the pressure-sensitive adhesive composition of the present invention is applied to a surface protective film, the plastic substrate used for the protective film is more preferably subjected to antistatic treatment. By subjecting the plastic substrate to an antistatic treatment, it is possible to more effectively reduce the stripping voltage on the adherend, and further to obtain an excellent antistatic ability.

  The pressure-sensitive adhesive composition of the present invention comprises a (meth) acrylic polymer having 0.01 to 20% by weight of a reactive surfactant as a monomer unit, and an ionic liquid.

  The ionic liquid in the present invention refers to a molten salt (ionic compound) that exhibits a liquid state at 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.

[R _a in the formula (A) represents a hydrocarbon group having 4 to 20 carbon atoms and may include a hetero atom, and R _b and R _c may be the same or different, and may be hydrogen or _C 1 to _C 16. Represents a hydrocarbon group and may contain heteroatoms. However, when the nitrogen atom contains a double bond, there is no R _c . ]
[R _d in the formula (B) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a hetero atom, and R _e , R _f , and R _g are the same or different and represent hydrogen or carbon number. Represents 1 to 16 hydrocarbon groups and may contain heteroatoms. ]
[R _h in the formula (C) represents a hydrocarbon group having 2 to 20 carbon atoms, and may contain a hetero atom, and R _i , R _j , and R _k may be the same or different and represent hydrogen or carbon number. Represents 1 to 16 hydrocarbon groups and may contain heteroatoms. ]
[Z in Formula (D) represents a nitrogen, sulfur, or phosphorus atom, and R ₁ , R _m , R _n , and R _o are the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms. And may contain heteroatoms. 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, for example, 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-propylpyrrolidi Cation, 1-methyl-1-butylpyrrolidinium cation, 1-methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium Cation, 1-ethyl-1-propylpyrrolidini Cation, 1-ethyl-1-butylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation, 1-ethyl-1-hexylpyrrolidinium cation, 1-ethyl-1-heptylpyrrolidinium Cation, 1,1-dipropylpyrrolidinium cation, 1-propyl-1-butylpyrrolidinium cation, 1,1-dibutylpyrrolidinium cation, 1-propylpiperidinium cation, 1-pentylpiperidinium cation 1,1-dimethylpiperidinium cation, 1-methyl-1-ethylpiperidinium cation, 1-methyl-1-propylpiperidinium cation, 1-methyl-1-butylpiperidinium cation, 1-methyl -1-pentylpiperidinium cation, 1-methyl-1-hexylpiperidi Cation, 1-methyl-1-heptylpiperidinium cation, 1-ethyl-1-propylpiperidinium cation, 1-ethyl-1-butylpiperidinium cation, 1-ethyl-1-pentylpiperidinium cation 1-ethyl-1-hexylpiperidinium cation, 1-ethyl-1-heptylpiperidinium cation, 1,1-dipropylpiperidinium cation, 1-propyl-1-butylpiperidinium cation, 1 , 1-dibutylpiperidinium cation, 2-methyl-1-pyrroline cation, 1-ethyl-2-phenylindole cation, 1,2-dimethylindole cation, 1-ethylcarbazole cation.

  Examples of the cation represented by the formula (B) include an imidazolium cation, a tetrahydropyrimidinium cation, and a dihydropyrimidinium cation.

  Specific examples include, for example, 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, and 1-helium. Xyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methylimidazolium cation, 1-tetradecyl-3-methylimidazole Cation, 1,2-dimethyl-3-propylimidazolium cation, 1-ethyl-2,3-dimethylimidazolium cation, 1-butyl-2,3-dimethylimidazolium cation, 1-hexyl-2,3 -Dimethylimidazolium 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-dihydropyrimidi Cation, 1,3-dimethyl-1,6-dihydropyrimidinium cation, 1,2,3-trimethyl-1,4-dihydropyrimidinium cation, 1,2,3-trimethyl-1,6-dihydro Pyrimidinium cation, 1,2,3,4-tetramethyl-1,4-dihydropyrimidinium cation, 1,2,3,4-tetramethyl-1,6-dihydropyrimidini Such as Mukachion, and the like.

  Examples of the cation represented by the formula (C) include a pyrazolium cation and a pyrazolinium cation.

  Specific examples include, for example, 1-methylpyrazolium cation, 3-methylpyrazolium cation, 1-ethyl-2-methylpyrazolinium cation, 1-ethyl-2,3,5-trimethylpyrazolium cation. 1-propyl-2,3,5-trimethylpyrazolium cation, 1-butyl-2,3,5-trimethylpyrazolium cation, 1-ethyl-2,3,5-trimethylpyrazolinium cation, 1 -Propyl-2,3,5-trimethylpyrazolinium cation, 1-butyl-2,3,5-trimethylpyrazolinium cation and the like.

  As the cation represented by the formula (D), for example, a tetraalkylammonium cation, a trialkylsulfonium cation, a tetraalkylphosphonium cation, or a part of the alkyl group is substituted with an alkenyl group, an alkoxyl group, or an epoxy group. And so on.

  Specific examples include, for example, tetramethylammonium cation, tetraethylammonium cation, tetrabutylammonium cation, tetrapentylammonium cation, tetrahexylammonium cation, tetraheptylammonium cation, triethylmethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyltrimethylammonium cation, trimethylsulfonium cation, triethylsulfonium cation, tributylsulfonium cation, trihexylsulfonium cation, diethylmethylsulfonium cation, dibutyl Ethylsulfonium Kachi , Dimethyldecylsulfonium cation, tetramethylphosphonium cation, tetraethylphosphonium cation, tetrabutylphosphonium cation, tetrahexylphosphonium cation, tetraoctylphosphonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation, trimethyldecylphosphonium cation, diallyldimethylammonium cation Etc. Among them, asymmetric such as triethylmethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation, trimethyldecylphosphonium cation, etc. Tetraalkylammonium cation, trialkylsulfonium cation, tetraalkylphosphonium cation, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyltrimethylammonium cation, diallyldimethylammonium cation, N, N -Dimethyl-N-ethyl-N-propyla Monium 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, N-dipropylammonium cation, N, N-diethyl-N-propyl-N-butylammonium cation, N, N-dimethyl-N-propyl-N-pentylammonium cation, N, N-dimethyl-N-propyl-N-hexylammonium cation, N, N- Dimethyl-N-propyl-N-heptylammonium cation, N, N-di Tyl-N-butyl-N-hexylammonium cation, N, N-diethyl-N-butyl-N-heptylammonium cation, N, N-dimethyl-N-pentyl-N-hexylammonium cation, N, N-dimethyl- N, N-dihexylammonium cation, trimethylheptylammonium 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-N-pentylammonium 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-dipropyl- N, N-dihexylammonium cation, N, N-dibutyl-N-methyl-N-pentylammonium cation, N, N-dibutyl-N-methyl-N-hexylammonium cation, trioctylmethylammonium cation, N-methyl- N-ethyl-N-propyl-N-pentylammonium cation is 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 ⁻ or the like is 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 a combination of the above cation component and anion component. For example, 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 (pentafluoro Ethanesulfonyl) imide, 1-hexylpyridinium tetrafluoroborate, 1,1-dimethylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-ethylpyrrolidinium bis Trifluoromethanesulfonyl) imide, 1-methyl-1-propylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-butylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-pentylpyrrole Dinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-hexylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-heptylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1- Ethyl-1-propylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-butylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-pentylpyrrolidinium bis (trifluoro Tansulfonyl) imide, 1-ethyl-1-hexylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-heptylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1,1-dipropylpyrrole Dinium bis (triple olomethanesulfonyl) imide, 1-propyl-1-butylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1,1-dibutylpyrrolidinium bis (triple methanesulfonyl) imide, 1-propylpi Peridinium bis (trifluoromethanesulfonyl) imide, 1-pentylbiberidinium bis (trifluoromethanesulfonyl) imide, 1,1-dimethylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-ethylpiperidini Umbis (trifluoromethanesulfonyl) imide, 1-methyl-1-propylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-butylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1- Pentylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-hexylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-heptylpiperidinium bis (trifluoromethanesulfonyl) imide, 1 -Ethyl-1-propylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-butylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-pentylpiperidinium bis (tri Fluoromethanesulfonyl) imide, 1-ethyl-1-hexylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-heptylpiperidinium bis (trifluoromethanesulfonyl) imide, 1,1-dipropyl Piperidinium bis (trifluoromethanesulfonyl) imide, 1-propyl-1-butylpiperidiniumpis (trifluoromethanesulfonyl) imide, 1,1-dibutylpiperidinium bis (trifluoromethanesulfonyl) imide, 1,1-dimethyl Pyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-ethylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-propylpyrrolidinium bis (pentafluoroethanesulfonyl) i 1-methyl-1-butylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-pentylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-hexylpyrrolidi Nitrobis (pentafluoroethanesulfonyl) imide, 1-methyl-1-heptylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-propylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1 -Ethyl-1-butylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-pentylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-hexylpyrrolidinium bis ( Pentafluoroethanesulfonyl) 1-ethyl-1-heptylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1,1-dipropylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-propyl-1-butylpyrrolidinium Bis (pentafluoroethanesulfonyl) imide, 1,1-dibutylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-propylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-pentylpiperidinium bis (venta) Fluoroethanesulfonyl) imide, 1,1-dimethylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-ethylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-propylpi Peridiniu Bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-butylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-pentylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl -1-hexylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-heptylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-propylpiperidinium bis (penta Fluoroethanesulfonyl) imide, 1-ethyl-1-butylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-pentylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1- Hexylpiperidini Mubis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-heptylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1,1-dipropylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-propyl -1-butylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1,1-dibutylpiperidinium bis (pentafluoroethanesulfonyl) imide, 2-methyl-1-pyrroline tetrafluoroborate, 1-ethyl-2- Phenylindole tetrafluoroborate, 1,2-dimethylindole tetrafluoroborate, 1-ethylcarbazole tetrafluoroborate, 1-ethyl-2-methylimidazolium tetrafluoroborate, 1-ethyl-2-methylimidazolium Acetate, 1-ethyl-2-methylimidazolium trifluoroacetate, 1-ethyl-2-methylimidazolium heptafluorobutyrate, 1-ethyl-2-methylimidazolium trifluoromethanesulfonate, 1-ethyl-2-methyl Imidazolium perfluorobutanesulfonate, 1-ethyl-2-methylimidazolium dicyanamide, 1-ethyl-2-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-ethyl-2-methylimidazolium bis (pentafluoroethanesulfonyl) ) Imido, 1-ethyl-2-methylimidazolium tris (trifluoromethanesulfonyl) methide, 1-butyl-2-methylimidazolium tetrafluoroborate, 1-butyl-2-methylimidazolium hex Fluorophosphate, 1-butyl-2-methylimidazolium trifluoroacetate, 1-butyl-2-methylimidazolium heptafluorobutyrate, 1-butyl-2-methylimidazolium trifluoromethanesulfonate, 1-butyl-2-methyl Imidazolium perfluorobutanesulfonate, 1-butyl-2-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-hexyl-2-methylimidazolium bromide, 1-hexyl-2-methylimidazolium chloride, 1-hex Xyl-2-methylimidazolium tetrafluoroborate, 1-hexyl-2-methylimidazolium hexafluorophosphate, 1-hexyl-2-methylimidazolium trifluoromethanesulfonate, 1-octyl Ru-2-methylimidazolium tetrafluoroborate, 1-octyl-2-methylimidazolium hexafluorophosphate, 1-hexyl-2,2-dimethylimidazolium tetrafluoroborate, 1,2-dimethyl-2-propylimidazo Bis (trifluoromethanesulfonyl) imide, tetrapentylammonium cation, tetrahexylammonium cation, tetraheptylammonium cation, tetraoctylphosphonium cation, 1-methylpyrazolium tetrafluoroborate, 2-methylpyrazolium tetrafluoroporate, 1 -Ethyl-2,3,5-trimethylpyrazolium bis (trifluoromethanesulfonyl) imide, 1-propyl-2,3,5-trimethylpyrazolium bis (trifluoro Methanesulfonyl) imide, 1-butyl-2,3,5-trimethylpyrazolium bis (trifluoromethanesulfonyl) imide, 1-ethyl-2,3,5-trimethylpyrazolium bis (pentafluoroethanesulfonyl) imide, 1-propyl-2,3,5-trimethylpyrazolium bis (pentafluoroethanesulfonyl) imide, 1-butyl-2,3,5-trimethylpyrazolium bis (pentafluoroethanesulfonyl) imide, 1-ethyl- 2,3,5-trimethylpyrazolium bis (trifluoromethanesulfonyl) trifluoroacetamide, 1-propyl-2,3,5-trimethylpyrazolium bis (trifluoromethanesulfonyl) trifluoroacetamide, 1-butyl-2, 3,5-trimethylpyrazolium bis (to Fluoromethanesulfonyl) trifluoroacetamide, 1-ethyl-2,3,5-trimethylpyrazolinium bis (trifluoromethanesulfonyl) imide, 1-propyl-2,3,5-trimethylpyrazolinium bis (trifluoromethanesulfonyl) Imido, 1-butyl-2,3,5-trimethylpyrazolinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-2,3,5-trimethylpyrazolinium bis (pentafluoroethanesulfonyl) imide, 1-propyl -2,3,5-trimethylpyrazolinium bis (pentafluoroethanesulfonyl) imide, 1-butyl-2,3,5-trimethylpyrazolinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-2,3 , 5-Trimethylpyrazolinium bi (Trifluoromethanesulfonyl) trifluoroacetamide, 1-propyl-2,3,5-trimethylpyrazolinium bis (trifluoromethanesulfonyl) trifluoroacetamide, 1-butyl-2,3,5-trimethylpyrazolinium bis (trifluoro) (Romethanesulfonyl) trifluoroacetamide, tetrapentylammonium trifluoromethanesulfonate, tetrapentylammonium bis (trifluoromethanesulfonyl) imide, tetrahexylammonium trifluoromethanesulfonate, tetrahexylammonium bis (trifluoromethanesulfonyl) imide, tetrahebutylammonium trifluoromethanesulfonate Tetraheptylammonium bis (trifluoromethanesulfonyl) imide, di Allyldimethylammonium tetrafluoroborate,
Diallyldimethylammonium trifluoromethanesulfonate, diallyldimethylammonium bis (trifluoromethanesulfonyl) imide, diallyldimethylammonium bis (pentafluoroethanesulfonyl) imide, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium tetra Fluoroborate, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium trifluoromethanesulfonate, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl) ) Imide, N, N-diethyl-Nmethyl-N- (2-methoxyethyl) ammonium bis (pentafluoroethanesulfonyl) imide, glycidyltrimethylammonium trifluoro Tansulfonate, glycidyltrimethylammonium bis (trifluoromethanesulfonyl) imide, glycidyltrimethylammonium bis (pentafluoroethanesulfonyl) imide, tetraoctylphosphonium trifluoromethanesulfonate, tetraoctylphosphonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl- N-ethyl-N-propylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-butylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N- Pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-hexylammonium bis (trifluorometa Sulfonyl) 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-butylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N- Propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-heptylammonium Screw 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, 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 (trif Olomethanesulfonyl) 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 (trifluoromethanesulfonyl) imide, triethylheptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N-methyl-N-ethylammonium bis (tri Fluoromedansulfonyl) 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 (trifluoromethanesulfonyl) imide, trioctylmethylammonium bis (trifluoromethanesulfonyl) imide, N-methyl-N- Ethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, 1-butylpyridinium (trifluoromethanesulfonyl) trifluoroacetamide, 1-butyl-3-methylpyridinium Trifluoromethanesulfonyl) trifluoroacetamide, 1-ethyl-3-methylimidazolium (trifluoromethanesulfonyl) trifluoroacetamide and the like.

  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), and chlorine, bromine, and iodine are used as the halogen).

Acid (HA) or salt having the anionic structure (A ⁻ ) of the ionic liquid intended for the obtained halide (MA and M are cations that form a salt with the intended anion such as ammonium, lithium, sodium, potassium, etc.) ) To obtain the desired ionic liquid (R ₄ NA).

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 a hydroxide (R ₄ NOH) (chlorine, bromine and iodine are used as the halogen).

The target ionic liquid (R ₄ NA) can be obtained from the obtained hydroxide using the reactions of the reaction formulas (7) to (8) in the same manner as the halogenation method.

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, inorganic acids such as sulfuric acid, sulfurous acid, phosphoric acid, phosphorous acid, and carbonic acid are used. And esters of organic acids such as esters, methanesulfonic acid, methylphosphonic acid, formic acid, etc.).

The target ionic liquid (R ₄ NA) is obtained from the obtained acid ester using 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)).

An ionic liquid can be obtained by complexing the obtained quaternary ammonium fluoride with a fluoride such as BF ₃ , AlF ₃ , PF ₅ , ASF ₅ , SbF ₅ , NbF ₅ , TaF ₅ (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 polymer to be used and the ionic liquid, but is generally 0.01 to 40 weights with respect to 100 parts by weight of the base polymer. Parts, preferably 0.01 to 30 parts by weight, more preferably 0.03 to 20 parts by weight, still more preferably 0.03 to 10 parts by weight, particularly preferably 0.03 to 4.9 parts by weight, 0.05-3 parts by weight is most preferred. 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 (meth) acrylic polymer having 0.01 to 20% by weight of a reactive surfactant as a monomer unit is used as a base polymer.

  The (meth) acrylic polymer used in the present invention is not particularly limited as long as it is a (meth) acrylic polymer having adhesive properties corresponding to those described above.

  The reactive surfactant in the present invention means one having a reactive unsaturated bond. Specific examples include an anionic reactive surfactant, a nonionic reactive surfactant, and a cationic reactive surfactant having an acryloyl group, a methacryloyl group, or an allyl group. Of these, an anionic reactive surfactant having a acryloyl group having an ethylene oxide group, a methacryloyl group or an allyl group, a nonionic reactive surfactant, a cationic reactive surfactant and the like are preferably used.

  Examples of the anionic reactive surfactant include those represented by formulas (A1) to (A16).

[R ₁ in Formula (A1) represents hydrogen or a methyl group, R ₂ represents a hydrocarbon group or acyl group having 1 to 30 carbon atoms, M represents an alkali metal, alkaline earth metal, ammonium group, or carbon A hydroxyalkylammonium group having 1 to 4 is represented, R ₃ and R ₄ are the same or different and represent an alkylene group having 1 to 6 carbon atoms, n is 0 to 50, and m is an integer of 0 to 20. ]

[R ₁ in Formula (A2) represents hydrogen or a methyl group, R ₂ represents a hydrocarbon group or an acyl group having 1 to 30 carbon atoms, and R ₃ and R ₄ may be the same or different, and 6 represents an alkylene group, and M ₁ and M ₂ are the same or different and each represents an alkali metal, an alkaline earth metal, an ammonium group, or a hydroxyalkylammonium group having 1 to 4 carbon atoms, and n is 0 to 50, m Represents an integer of 0-20. ]

[R ₁ and R _{2 in} Formula (A3) represent hydrogen or a methyl group, R ₃ represents an alkyl group or an alkenyl group having 1 to 20 carbon atoms, and M represents an alkali metal, alkaline earth metal, or ammonium group. To express. ]

[R ₁ in Formula (A4) represents hydrogen or a methyl group, R ₂ and R ₇ are the same or different, represent an alkylene group having 1 to 6 carbon atoms, and R ₃ and R ₅ are the same or different, Represents hydrogen or an alkyl group, R ₄ and R ₆ are the same or different and represent hydrogen, an alkyl group, a benzyl group or a styrene group, M represents an alkali metal, alkaline earth metal or ammonium group, and n and m represent Represents an integer of 1-50. ]

[R ₁ in Formula (A5) represents hydrogen or a methyl group, R ₂ represents an alkylene group having 1 to 6 carbon atoms, M represents an alkali metal, alkaline earth metal, or ammonium group, and n represents 2 to 2 Represents an integer of 50. "

[R ₁ in Formula (A6) represents hydrogen or a methyl group, R ₂ represents a hydrocarbon group or an acyl group having 1 to 30 carbon atoms, and R ₃ and R ₄ may be the same or different, and 6 represents an alkylene group, M represents an alkali metal, an alkaline earth metal, an ammonium group, or a hydroxyalkylammonium group having 1 to 4 carbon atoms, n represents an integer of 0 to 50, and m represents an integer of 0 to 20. ]

[R ₁ in Formula (A7) represents hydrogen or a methyl group, R ₂ represents a hydrocarbon group or an acyl group having 1 to 30 carbon atoms, and R ₃ and R ₄ may be the same or different, and 6 represents an alkylene group, and M ₁ and M ₂ are the same or different and each represents an alkali metal, an alkaline earth metal, an ammonium group, or a hydroxyalkylammonium group having 1 to 4 carbon atoms, and n is 0 to 50, m Represents a number from 0 to 20. ]

  [R in Formula (A8) represents a hydrocarbon group having 1 to 30 carbon atoms or an oxyalkylene group having 1 to 6 carbon atoms. ]

[R ₁ in Formula (A9) represents a hydrocarbon group, an amino group, or a carboxylic acid residue, R ₂ represents an alkylene group having 1 to 6 carbon atoms, and n represents an integer of 0 to 50. ]

[In Formula (A10), R ₁ represents a hydrocarbon group having 1 to 30 carbon atoms, R ₂ represents hydrogen or a hydrocarbon group having 1 to 30 carbon atoms, R ₃ represents hydrogen or a propenyl group, and R ₄ represents Represents an alkylene group having 1 to 6 carbon atoms, M represents an alkali metal, alkaline earth metal, ammonium group or alkanolamine residue, and n represents an integer of 1 to 50. ]

[R ₁ in Formula (A11) represents hydrogen or a methyl group, R ₂ and R ₄ are the same or different and each represents an alkylene group having 1 to 6 carbon atoms, and R ₃ represents a hydrocarbon having 1 to 30 carbon atoms. Represents a group, M represents hydrogen, an alkali metal, an alkaline earth metal, an ammonium group or an alkanol ammonium group, and n and m represent an integer of 1 to 50. ]

[And _{R 1} and _{R 5} in the formula (A12) the same or different, represent a hydrogen or a methyl group, _{R 2} and _{R 4} are the same or different and each represents an alkylene group having a carbon number of 1 to 6, _{R 3} is A hydrocarbon group having 1 to 30 carbon atoms is represented, M represents hydrogen, an alkali metal, an alkaline earth metal, an ammonium group or an alkanol ammonium group, and n and m represent an integer of 1 to 50. ]

  “R in the formula (A13) represents a hydrocarbon group having 1 to 30 carbon atoms, and M represents an alkali metal, alkaline earth metal, or ammonium group.]

[R ₁ in Formula (A14) represents an alkylene group having 1 to 6 carbon atoms, R ₂ represents a hydrocarbon group having 1 to 30 carbon atoms, and M represents hydrogen, an alkali metal, an alkaline earth metal, or an ammonium group. Or an amine group is represented, n represents the integer of 1-50. ]

  [R in the formula (A15) represents a hydrocarbon group having 1 to 30 carbon atoms, M represents hydrogen, an alkali metal, an alkaline earth metal, or an ammonium group, n is 1 or 2, and m is 2 to 4. Represents an integer. ]

  [R in Formula (A16) represents a hydrocarbon group having 1 to 30 carbon atoms, and M represents hydrogen, an alkali metal, an alkaline earth metal, or an ammonium group. ]

  Examples of the nonionic reactive surfactant include those represented by the formulas (N1) to (N5).

[R ₁ in Formula (N1) represents hydrogen or a methyl group, R ₂ represents a hydrocarbon group or an acyl group having 1 to 30 carbon atoms, and R ₃ and R ₄ may be the same or different, and 6 represents an alkylene group, and n and m each represents an integer of 0 to 50. ]

[R in Formula (N2) represents hydrogen or a methyl group, R ₂ , R ₃ , and R ₄ are the same or different and each represents an alkylene group having 1 to 6 carbon atoms, and n, m, and l are 0 to 50, where n + m + 1 represents an integer of 1-50. ]

[R ₁ in Formula (N3) represents hydrogen or a methyl group, R ₂ and R ₃ are the same or different and each represents an alkylene group having 1 to 6 carbon atoms, and R ₄ represents a hydrocarbon having 1 to 30 carbon atoms. Represents a group or an acyl group, and n and m represent an integer of 0 to 50. ]

[R ₁ and R _{2 in} formula (N4) are the same or different and each represents a hydrocarbon group having 1 to 30 carbon atoms, R ₃ represents hydrogen or a propenyl group, and R ₄ represents an alkylene having 1 to 6 carbon atoms Represents a group, and n represents an integer of 1 to 50. ]

[In formula (N5), R ₁ and R ₃ are the same or different and each represents an alkylene group having 1 to 6 carbon atoms; R ₂ and R ₄ are the same or different and represent hydrogen, a hydrocarbon group having 1 to 30 carbon atoms or Represents an acyl group, n and m are 0 to 50, and n + m represents an integer of 3 to 50. ]

  Examples of the cationic reactive surfactant include those represented by the formulas (C1) to (C2).

[R ₁ and R _{2 in} Formula (C1) are the same or different and each represents an alkyl group having 1 to 30 carbon atoms, R ₃ represents a hydrocarbon group having 1 to 30 carbon atoms, and X represents chlorine or bromine. . ]

  [R in the formula (C2) represents a hydrocarbon group having 1 to 30 carbon atoms and may contain a hetero atom. ]

  The reactive surfactant may be used alone or in combination of two or more, but is 0.01 to 20% by weight in the monomer component of the (meth) acrylic polymer. It is preferably 0.05 to 10% by weight, more preferably 0.1 to 5% by weight. When the content of the reactive surfactant is less than 0.01% by weight, the effect of suppressing bleeding of the ionic liquid and the effect of reducing contamination of the protected body in the present invention may not be obtained. On the other hand, if it exceeds 20% by weight, there is a risk of contamination of the object to be protected, which is not preferable.

  Further, in the present invention, in addition to the reactive surfactant monomer component described above, a (meth) acrylic monomer component or a (meth) acrylic polymer having an alkyl group having 1 to 14 carbon atoms is used. Other polymerizable monomer components for adjusting the glass transition point and peelability can be used.

  As the (meth) acrylic monomer component having an alkyl group having 1 to 14 carbon atoms, it is particularly preferable to use a (meth) acrylate having an alkyl group having 2 to 13 carbon atoms.

  Specific examples of the (meth) acrylic monomer component having an alkyl group having 1 to 14 carbon atoms include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and s-butyl. (Meth) acrylate, t-butyl (meth) acrylate, 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, etc. can give.

  Among them, n-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (Meth) acrylates such as (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, and isodecyl (meth) acrylate are preferably used.

  The above (meth) acrylic monomer component may be used alone, or two or more kinds may be used in combination, but the total content is determined by the polymerization of the (meth) acrylic polymer. It is preferably 50 to 99.99% by weight in the monomer component, more preferably 60 to 99% by weight, and particularly preferably 70 to 95% by weight. By using the (meth) acrylic monomer component, good interaction with the ionic liquid and good adhesiveness can be appropriately adjusted.

  In addition, as other polymerizable monomer components, a polymerizable monomer for adjusting the glass transition point and peelability of the (meth) acrylic polymer can be used as long as the effects of the present invention are not impaired. .

  Other polymerizable monomer components include, for example, components for improving cohesion and heat resistance such as sulfonic acid group-containing monomers, phosphate group-containing monomers, cyano group-containing monomers, vinyl esters, aromatic vinyl compounds, and carboxyl Adhesion improvement and crosslinking of group-containing monomers, acid anhydride group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, amino group-containing monomers, imide group-containing monomers, epoxy group-containing monomers, N-acryloylmorpholine, vinyl ethers, etc. A component having a functional group serving as a linking base point can be used as appropriate. Other components can be used alone or in combination of two or more.

  However, when using a (meth) acrylate having an acid functional group such as a carboxyl group, a sulfonic acid group, or a phosphoric acid group, it is preferable to adjust the acid value of the (meth) acrylic polymer to be 29 or less. . When the acid value of the (meth) acrylic polymer exceeds 29, the antistatic property tends to deteriorate. Furthermore, when applying to a surface protection film, it is preferable to adjust so that the acid value of a (meth) acrylic-type polymer may become 1 or less. When the acid value of the (meth) acrylic polymer exceeds 1, the adhesive strength with time tends to increase.

  The acid value can be adjusted by adjusting the amount of (meth) acrylate having an acid functional group. For example, 2-ethylhexyl acrylate and acrylic acid are copolymerized as a (meth) acrylic polymer having a carboxyl group (meth) ) Acrylic polymer can be mentioned. In this case, the acid value is adjusted 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. Can be satisfied.

  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). Examples include acryloyloxynaphthalene sulfonic acid and sodium vinyl sulfonate.

  Examples of the phosphate group-containing monomer include 2-hydroxyethyl acryloyl phosphate.

  Examples of the cyano group-containing monomer include acrylonitrile and methacrylonitrile.

  Examples of vinyl esters include vinyl acetate, vinyl propionate, vinyl laurate, and the like.

  Examples of the aromatic vinyl compound include styrene, chlorostyrene, chloromethyl styrene, α-methyl styrene, other substituted styrenes, and the like.

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

  Examples of the acid anhydride group-containing monomer include maleic anhydride, itaconic anhydride, and acid anhydride bodies of the above carboxyl group-containing monomers.

  Examples of the hydroxyl group-containing monomer include 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, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, Examples include diethylene glycol monovinyl ether.

  Examples of amide group-containing monomers include acrylamide, methacrylamide, diethyl acrylamide, N-vinyl pyrrolidone, N, N-dimethyl acrylamide, N, N-dimethyl methacrylamide, N, N-diethyl acrylamide, N, N-diethyl methacryl. Examples thereof include amide, N, N′-methylenebisacrylamide, N, N-dimethylaminopropyl acrylamide, N, N-dimethylaminopropyl methacrylamide and the like.

  Examples of the amino group-containing monomer include aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, (meth) acryloylmorpholine, and the like.

  Examples of the imide group-containing monomer include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide, and itaconimide.

  Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, and allyl glycidyl ether.

  Examples of vinyl ethers include methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, and the like.

  The above-mentioned other polymerizable monomer components may be used alone or in combination of two or more, but the total content is the polymerizable monomer of the (meth) acrylic polymer. It is preferably 0 to 49.99% by weight in the monomer component, more preferably 0.5 to 40% by weight, and particularly preferably 1 to 20% by weight. By using the other polymerizable monomer components described above, good interaction with the ionic liquid and good adhesiveness can be appropriately adjusted.

  The (meth) acrylic polymer used in the present invention has a weight average molecular weight of 100,000 to 5,000,000, preferably 200,000 to 4,000,000, more preferably 300,000 to 3,000,000. When the weight average molecular weight is smaller than 100,000, the adhesive force tends to be generated due to a decrease in the cohesive force of the pressure-sensitive adhesive composition. On the other hand, when the weight average molecular weight exceeds 5,000,000, the fluidity of the polymer is lowered and the wettability to the polarizing plate becomes insufficient, and the swelling generated between the polarizing plate and the pressure-sensitive adhesive composition layer of the surface protective film is reduced. There is a tendency to cause. A weight average molecular weight means what was obtained by measuring by GPC (gel permeation chromatography).

  Moreover, although the glass transition temperature (Tg) of the said (meth) acrylic-type polymer is normally -100 degreeC or more as a base polymer, it is preferable that it is -90 degreeC-0 degreeC, -80 degreeC-- More preferably, it is 10 ° C. When the glass transition temperature is higher than 0 ° C., the polymer is difficult to flow and the wetting to the polarizing plate is insufficient, and the cause of the swelling generated between the polarizing plate and the layer made of the pressure-sensitive adhesive composition of the surface protective film Tend to be. In addition, the glass transition temperature (Tg) of a (meth) acrylic-type polymer can be adjusted in the said range by changing the monomer component and composition ratio to be used suitably.

  The (meth) acrylic polymer of the present invention 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. Moreover, the polymer obtained may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

  The pressure-sensitive adhesive of the present invention can provide a pressure-sensitive adhesive sheet with further excellent heat resistance by appropriately crosslinking a base polymer, particularly an acrylic polymer. As specific means of the crosslinking method, it can react with a carboxyl group, a hydroxyl group, an amino group, an amide group, or the like appropriately included as a crosslinking base in an acrylic polymer such as an isocyanate compound, an epoxy compound, a melamine resin, or an aziridine compound. There is a method using a so-called crosslinking agent in which a compound having a group is added and reacted. Among these, an isocyanate compound and an epoxy compound 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.

  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.

  More specifically, as the isocyanate compound, for example, lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate, 2, 4 -Aromatic diisocyanates such as tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, trimethylolpropane / tolylene diisocyanate trimer adduct (trade name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.), tri Methylolpropane / hexamethylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate HL), hexamethylene diisocyanate Over the door of the isocyanurate body (Nippon Polyurethane Industry Co., Ltd., trade name: Coronate HX) isocyanate adducts such as, and the like. These isocyanate compounds may be used alone or in combination of two or more.

  Examples of the epoxy compound include N, N, N ′, N′-tetraglycidyl-m-xylenediamine (manufactured by Mitsubishi Gas Chemical Company, trade name: TETRAD-X), and 1,3-bis (N, N-dioxy). Glycidylaminomethyl) cyclohexane (manufactured by Mitsubishi Gas Chemical Company, trade name: TETRAD-C). These compounds may be used alone or in combination of two or more.

  Examples of the melamine-based resin include hexamethylol melamine.

  Examples of the aziridine derivative include a commercial product name HDU, a product name TAZM, a product name TAZO (manufactured by Mutual Pharmaceutical Co., Ltd.), and the like. These compounds may be used alone or in combination of two or more.

  The amount of these crosslinking agents to be used is appropriately selected depending on the balance with the (meth) acrylic polymer to be crosslinked, and further depending on the intended use as the pressure-sensitive adhesive sheet. In general, in order to obtain sufficient heat resistance due to the cohesive force of the acrylic pressure-sensitive adhesive, it is preferably contained in an amount of 0.01 to 15 parts by weight with respect to 100 parts by weight of the acrylic polymer. More preferably, 10 parts by weight is contained. When the content is less than 0.01 part by weight, the crosslinking formation by the crosslinking agent is insufficient, the cohesive force of the pressure-sensitive adhesive composition is reduced, and sufficient heat resistance may not be obtained. There is a tendency to cause the rest. On the other hand, when the content exceeds 15 parts by weight, the cohesive force of the polymer is large, the fluidity is lowered, the wettability to the adherend is insufficient, and it tends to cause peeling.

  Further, it can be added as a polyfunctional monomer having two or more radiation-reactive unsaturated bonds as a substantial cross-linking agent, and cross-linked by radiation or the like. Polyfunctional monomers having two or more radiation-reactive unsaturated bonds include one or more types of radiation 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 reactive unsaturated bonds 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, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and 1,6 hexanediol. Examples include di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, divinylbenzene, and N, N′-methylenebisacrylamide.

  The amount of the polyfunctional monomer used is appropriately selected depending on the balance with the (meth) acrylic polymer to be crosslinked, and further depending on the intended use as the pressure-sensitive 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 in an amount of 0.1 to 30 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer. Moreover, it is more preferable to mix | blend at 10 weight part or less with respect to 100 weight part of (meth) acrylic-type polymers from the point of a softness | flexibility and adhesiveness.

  Examples of radiation include ultraviolet rays, laser rays, α rays, β rays, γ rays, X rays, electron rays, etc., but ultraviolet rays are preferably used from the viewpoints of good controllability and handleability and cost. It is done. 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 benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, o-benzoylbenzoic acid methyl-p-benzoin ethyl ether, benzoin isopropyl ether, α-methylbenzoin, benzyldimethyl ketal, trichloro Acetophenones such as acetophenone, 2,2-diethoxyacetophenone and 1-hydroxycyclohexyl phenyl ketone, pros such as 2-hydroxy-2-methylpropiophenone and 2-hydroxy-4′-isopropyl-2-methylpropiophenone Benzophenones such as piophenones, benzophenone, methylbenzophenone, p-chlorobenzophenone, p-dimethylaminobenzofuninone, 2-chlorothioxanthone, 2- Thioxanthones such as thiolthioxanthone and 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, and organometallic complexes such as iron-allene complexes, titanocene complexes, and arylsilanol-aluminum complexes, Examples thereof include nitrobenzyl ester, sulfonic acid derivative, phosphoric acid ester, phenol sulfonic acid ester, 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 (meth) 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 (meth) acrylic polymer.

  Furthermore, the pressure-sensitive adhesive used in the pressure-sensitive adhesive sheet of the present invention includes various conventionally known tackifiers and surface lubricants, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, ultraviolet absorbers, polymerization inhibitors, A silane coupling agent, an inorganic or organic filler, a powder such as a metal powder or a pigment, a particle, a foil, and the like may be added as appropriate according to the use for which various conventionally known additives are used. it can.

  On the other hand, the pressure-sensitive adhesive layer of the present invention is obtained by crosslinking the pressure-sensitive adhesive composition as described above. The pressure-sensitive adhesive sheet of the present invention is formed by forming such a pressure-sensitive adhesive layer on a support film. At that time, the pressure-sensitive adhesive composition is generally crosslinked after application of the pressure-sensitive adhesive composition, but the pressure-sensitive adhesive layer comprising the crosslinked pressure-sensitive adhesive composition can be transferred to a support film or the like. is there.

In the case where a photopolymerization initiator as an optional component is added as described above, the pressure-sensitive adhesive composition is applied directly on the object to be protected, or after being applied to one or both sides of the support substrate, An adhesive layer can be obtained by light irradiation. Usually, the pressure-sensitive adhesive layer is obtained by irradiating ultraviolet rays having an illuminance of 1 to 200 mW / cm ² at a wavelength of 300 to 400 nm and photopolymerizing them with a light amount of about 200 to 4000 mJ / cm ² .

  The method of forming the pressure-sensitive adhesive layer on the film is not particularly limited. For example, the pressure-sensitive adhesive composition is applied to the support film, and the polymerization solvent is dried and formed to form the pressure-sensitive adhesive layer on the support film. Produced. Thereafter, curing may be performed for the purpose of adjusting the component transfer of the pressure-sensitive adhesive layer or adjusting the crosslinking reaction. In addition, when a pressure-sensitive adhesive composition is applied on a support film to produce a pressure-sensitive adhesive sheet, one or more solvents other than the polymerization solvent are newly added to the composition so that the pressure-sensitive adhesive composition can be uniformly applied onto the support film. May be added.

  Moreover, as a formation method of the adhesive layer of this invention, the well-known method used for manufacture of an adhesive sheet is used. Specific examples include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, extrusion coating using a die coater, and the like.

  The pressure-sensitive adhesive sheet of the present invention comprises various supports made of a plastic film such as a polyester film or a porous material such as paper or nonwoven fabric so that the pressure-sensitive adhesive has a thickness of usually 3 to 100 μm, preferably about 5 to 50 μm. These are coated and formed on one or both sides of the sheet to form a sheet or tape. Particularly in the case of a surface protective film, it is preferable to use a plastic substrate as a support.

  The plastic substrate is not particularly limited as long as it can be formed into a sheet shape or a film shape. For example, polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene Polyolefin films such as propylene copolymer, ethylene / 1-butene copolymer, ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyl alcohol copolymer, polyethylene terephthalate, polyethylene naphthalate, poly Polyester film such as butylene terephthalate, polyacrylate film, polystyrene film, nylon 6, nylon 6,6, polyamide film such as partially aromatic polyamide, polyvinyl chloride film, polyvinylidene chloride film, polycarbonate Such as ball titanate film, and the like.

  The thickness of the film is usually about 5 to 200 μm, preferably about 10 to 100 μm.

  For plastic substrates, silicone, fluorine, long chain alkyl or fatty acid amide release agents, mold release with silica powder, antifouling treatment, acid treatment, alkali treatment, primer treatment, Anti-adhesive treatment such as corona treatment, plasma treatment and ultraviolet treatment, coating type, kneading type, vapor deposition type and the like can also be carried out.

  The plastic substrate used for the surface protective film of the present invention is more preferably subjected to antistatic treatment.

  The antistatic treatment applied to the plastic substrate is not particularly limited. For example, a method of providing an antistatic layer on at least one side of a generally used film or a method of kneading a kneading type antistatic agent into a plastic film. Used.

  Examples of a method of providing an antistatic layer on at least one surface of the film include, for example, a method of applying an antistatic resin composed of an antistatic agent and a resin component, a conductive polymer, or a conductive resin containing a conductive substance, or a conductive substance. The method of vapor-depositing or plating is mentioned.

  Examples of the antistatic agent contained in the antistatic resin include cationic antistatic agents having cationic functional groups such as quaternary ammonium salts, pyridinium salts, primary, secondary and tertiary amino groups, and sulfones. Anionic antistatic agents with anionic functional groups such as acid salts, sulfate esters, phosphonates, phosphate esters, alkylbetaines and derivatives thereof, imidazolines and derivatives thereof, and amphoteric antistatic agents such as alanine and derivatives thereof Nonionic antistatic agents such as agents, amino alcohols and derivatives thereof, glycerin and derivatives thereof, polyethylene glycol and derivatives thereof, and monomers having ion conductive groups of the above cation type, anion type and zwitterionic type Examples thereof include ionic conductive polymers obtained by polymerization or copolymerization. These compounds may be used alone or in combination of two or more.

  Specifically, as a cationic antistatic agent, for example, a quaternary ammonium group such as alkyltrimethylammonium salt, acyloylamidopropyltrimethylammonium methosulfate, alkylbenzylmethylammonium salt, acylcholine chloride, polydimethylaminoethyl methacrylate, etc. (Meth) acrylate copolymers having quaternary, styrene copolymers having quaternary ammonium groups such as polyvinylbenzyltrimethylammonium chloride, diallylamine copolymers having quaternary ammonium groups such as polydiallyldimethylammonium chloride, and the like. These compounds may be used alone or in combination of two or more.

  Examples of the anionic antistatic agent include alkyl sulfonate, alkyl benzene sulfonate, alkyl sulfate ester salt, alkyl ethoxy sulfate ester salt, alkyl phosphate ester salt, and sulfonic acid group-containing styrene copolymer. These compounds may be used alone or in combination of two or more.

  Examples of zwitterionic antistatic agents include alkylbetaines, alkylimidazolium betaines, and carbobetaine graft copolymers. These compounds may be used alone or in combination of two or more.

  Nonionic antistatic agents include, for example, fatty acid alkylolamide, di (2-hydroxyethyl) alkylamine, polyoxyethylene alkylamine, fatty acid glycerin ester, polyoxyethylene glycol fatty acid ester, sorbitan fatty acid ester, polyoxysorbitan fatty acid Examples thereof include esters, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl ethers, polyethylene glycols, polyoxyethylene diamines, copolymers composed of polyethers, polyesters and polyamides, and methoxypolyethylene glycol (meth) acrylates. These compounds may be used alone or in combination of two or more.

  Examples of the conductive polymer include polyaniline, polypyrrole, polythiophene and the like. These conductive polymers may be used alone or in combination of two or more.

  Examples of the conductive material include tin oxide, antimony oxide, indium oxide, cadmium oxide, titanium oxide, zinc oxide, indium, tin, antimony, gold, silver, copper, aluminum, nickel, chromium, titanium, iron, cobalt, Examples include copper iodide, and alloys or mixtures thereof. These conductive materials may be used alone or in combination of two or more.

  As the resin component used for the antistatic resin and the conductive resin, for example, general-purpose resins such as polyester, acrylic, polyvinyl, urethane, melamine, and epoxy are used. In the case of a polymer type antistatic agent, it is not necessary to contain a resin component. In addition, the antistatic resin component may contain a methylolated or alkylolized melamine-based, urea-based, glyoxal-based, acrylamide-based compound, an epoxy compound, or an isocyanate compound as a crosslinking agent.

  The antistatic layer can be formed by, for example, diluting the antistatic resin, conductive polymer, or conductive resin with a solvent such as an organic solvent or water, and applying and drying the coating liquid on a plastic film. Is done.

  Examples of the organic solvent used for forming the antistatic layer include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexanone, n-hexane, toluene, xylene, methanol, ethanol, n-propanol, and isopropanol. can give. These solvents may be used alone or in combination of two or more.

  As a coating method in forming the antistatic layer, a known coating method is appropriately used. Specifically, for example, roll coating, gravure coating, reverse coating, roll brush, spray coating, air knife coating, impregnation and curtain coating are used. The law is raised.

  The thickness of the antistatic resin layer, the conductive polymer, and the conductive resin is usually about 0.01 to 5 μm, preferably about 0.03 to 1 μm.

  Examples of the method for depositing or plating the conductive material include vacuum deposition, sputtering, ion plating, chemical vapor deposition, spray pyrolysis, chemical plating, and electroplating.

  The thickness of the conductive material layer is usually 20 to 10,000 mm, preferably 50 to 5000 mm.

  Further, as the kneading type antistatic agent, the above antistatic agent is appropriately used.

  The amount of the kneading type antistatic agent is 20% by weight or less, preferably 0.05 to 10% by weight, based on the total weight of the plastic film. The kneading method is not particularly limited as long as the antistatic agent can be uniformly mixed with the resin used for the plastic film. For example, a heating roll, a Banbury mixer, a pressure kneader, a biaxial kneader or the like is used. It is done.

  For plastic films, silicone-based, fluorine-based, long-chain alkyl or fatty acid amide-based release agents, mold release with silica powder, and antifouling treatment, acid treatment, alkali treatment, primer treatment, corona Easy adhesion treatment such as treatment, plasma treatment, and ultraviolet treatment can also be performed.

  In the pressure-sensitive adhesive sheet 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, polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene / propylene copolymer Polyolefin films such as ethylene / 1-butene copolymer, ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyl alcohol copolymer, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, etc. Polyester film, polyacrylate film, polystyrene film, nylon 6, nylon 6,6, polyamide film such as partially aromatic polyamide, polyvinyl chloride film, polyvinylidene chloride film, polycarbonate film Etc., and the like.

  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 composition and the pressure-sensitive adhesive sheet according to the present invention are used for plastic products that are particularly prone to generate static electricity, and in particular, polarizing plates, wave plates, optical compensation films, light diffusion films used for liquid crystal displays and the like. It can be used as a surface protective film used for the purpose of protecting the surface of an optical member such as a sheet or a reflective sheet.

  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.

<Measurement of acid value>
The acid value was measured using an automatic titration apparatus (Hiranuma Sangyo Co., Ltd., COM-550), and was determined from the following formula.
A = {(Y−X) × f × 5.611} / M
・ A: Acid value ・ Y: Titration volume of sample solution (ml)
X: Titration volume of a solution containing only 50 g of mixed solvent (ml)
F: Factor of titration solution M: Weight of polymer sample (g)

The measurement conditions are as follows.
Sample solution: About 0.5 g of a polymer sample was dissolved in 50 g of a mixed solvent (toluene / 2-propanol / distilled water = 50 / 49.5 / 0.5, weight ratio) to obtain a sample solution.
-Titration solution: 0.1N, 2-propanol potassium hydroxide solution (manufactured by Wako Pure Chemical Industries, Ltd., for petroleum product neutralization value test)
-Electrode: Glass electrode; GE-101, Comparative electrode; RE-201
Measurement mode: Petroleum product neutralization value test 1

<Measurement of molecular weight>
The molecular weight was measured using a GPC device (manufactured by Tosoh Corporation, HLC-8220GPC). The measurement conditions are as follows.
Sample concentration: 0.2 wt% (THF solution)
Sample injection volume: 10 μl
・ Eluent: THF
・ Flow rate: 0.6ml / min
・ Measurement temperature: 40 ℃
·column:
Sample column; TSKguardcolumn SuperHZ-H (1) + TSKgel SuperHZM-H (2)
Reference column; TSKgel SuperH-RC (1)
・ Detector: Differential refractometer (RI)
The molecular weight was determined in terms of polystyrene.

<Measurement of glass transition temperature>
The glass transition temperature (Tg) (° C.) of the obtained (meth) acrylic polymer was determined by dynamic viscoelasticity measurement according to the following procedure.

  A sheet of acrylic polymer having a thickness of 20 μm was laminated to a thickness of about 2 mm, and this was punched to φ7.9 mm to produce a cylindrical pellet, which was used as a glass transition temperature (Tg) measurement sample.

Using the above measurement sample, the measurement sample is fixed to a jig having a φ7.9 mm parallel plate, and the temperature dependence of the loss elastic modulus G ″ is measured by a dynamic viscoelasticity measuring device (ARES, manufactured by Rheometrics). The temperature at which the obtained G ″ curve was maximized was measured as the glass transition temperature (Tg) (° C.). The measurement conditions are as follows.
・ Measurement: Shear mode ・ Temperature range: −70 ° C. to 150 ° C.
・ Raising rate: 5 ° C / min
・ Frequency: 1 Hz

<Ionic liquid structure analysis>
The structural analysis of the ionic liquid was performed by NMR measurement, XRF measurement, and FT-IR measurement.

[NMR measurement]
The NMR measurement was performed under the following measurement conditions using a nuclear magnetic resonance apparatus (EX-400, manufactured by JEOL Ltd.).
・ Observation frequency: 400 MHz ( ¹ H), 100 MHz ( ¹³ C)
・ Measurement solvent: acetone-d ₆
・ Measurement temperature: 23 ℃

[XRF measurement]
XRF measurement was performed under the following measurement conditions using a scanning fluorescent X-ray analyzer (manufactured by Rigaku Corporation, ZSX-100e).
・ Measurement method: filter paper method ・ X-ray source: Rh

[FT-IR measurement]
The FT-IR measurement was performed using an infrared spectrophotometer (manufactured by Nicolet, Magna-560) under the following measurement conditions.
・ Measuring method: ATR method ・ Detector: DTGS
・ Resolution: 4.0cm ^-1
・ Total number of times: 64

<Preparation of base polymer>
(Acrylic polymer (A))
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, a cooler, and a dropping funnel, 195 parts by weight of 2-ethylhexyl acrylate, a nonionic reactive surfactant (Adekaria soap, manufactured by Asahi Denka Kogyo Co., Ltd.) ER-10) 5 parts by weight, 8 parts by weight of 2-hydroxyethyl acrylate, 0.4 part by weight of 2,2′-azobisisobutyronitrile and 312 parts by weight of ethyl acetate as a polymerization initiator were added and stirred gently. While introducing nitrogen gas, the temperature of the liquid in the flask was kept at around 65 ° C., and a polymerization reaction was carried out for 6 hours to prepare a solution (40% by weight) of an acrylic polymer (A). This acrylic polymer (A) had Tg = −10 ° C. or less, a weight average molecular weight of 680,000, and an acid value of 0.0.

(Acrylic polymer (B))
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, a condenser, and a dropping funnel, 200 parts by weight of 2-ethylhexyl acrylate, 8 parts by weight of 2-hydroxyethyl acrylate, 2,2 ′ as a polymerization initiator -Charge 0.4 parts by weight of azobisisobutyronitrile and 312 parts by weight of ethyl acetate, introduce nitrogen gas while gently stirring, and perform a polymerization reaction for 6 hours while maintaining the liquid temperature in the flask at around 65 ° C. A solution (40% by weight) of an acrylic polymer (B) was prepared. This acrylic polymer (B) had Tg = −10 ° C. or less, a weight average molecular weight of 550,000, and an acid value of 0.0.

(Acrylic polymer (C))
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, a cooler, and a dropping funnel, 198 parts by weight of 2-ethylhexyl acrylate, nonionic reactive surfactant (Adeka soap, manufactured by Asahi Denka Kogyo Co., Ltd.) ER-10) 2 parts by weight, 8 parts by weight of 2-hydroxyethyl acrylate, 0.4 part by weight of 2,2′-azobisisobutyronitrile and 386 parts by weight of ethyl acetate as a polymerization initiator were added and gently stirred. While introducing nitrogen gas, the temperature of the liquid in the flask was kept at around 60 ° C., and a polymerization reaction was carried out for 5 hours to prepare an acrylic polymer (C) solution (35% by weight). This acrylic polymer (C) had Tg = −10 ° C. or less, a weight average molecular weight of 440,000, and an acid value of 0.0.

(Acrylic polymer (D))
In a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, cooler, and dropping funnel, 193 parts by weight of 2-ethylhexyl acrylate, 6 parts by weight of diacetone acrylamide, nonionic reactive surfactant (Asahi Denka) Manufactured by Kogyo Co., Ltd., 1 part by weight of ADEKA rear soap ER-10), 8 parts by weight of 2-hydroxyethyl acrylate, 0.4 part by weight of 2,2′-azobisisobutyronitrile as a polymerization initiator, 312 parts by weight of ethyl acetate And nitrogen gas was introduced while gently stirring, and the polymerization temperature was maintained at around 60 ° C. for 5 hours to prepare a solution (40% by weight) of an acrylic polymer (D). This acrylic polymer (D) had Tg = −10 ° C. or less, a weight average molecular weight of 650,000, and an acid value of 0.0.

(Acrylic polymer (E))
In a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, cooler, and dropping funnel, 193 parts by weight of 2-ethylhexyl acrylate, 6 parts by weight of acryloylmorpholine, nonionic reactive surfactant (Asahi Denka Kogyo Co., Ltd.) Adecalia Soap ER-10) 1 part by weight, 2-hydroxyethyl acrylate 8 parts by weight, 2,2′-azobisisobutyronitrile 0.4 part by weight, ethyl acetate 312 parts by weight as a polymerization initiator Nitrogen gas was introduced while stirring and gently stirring, and the polymerization temperature was kept at around 60 ° C. for 5 hours to prepare a solution (40% by weight) of an acrylic polymer (E). This acrylic polymer (E) had Tg = −10 ° C. or less, a weight average molecular weight of 600,000, and an acid value of 0.0.

(Acrylic polymer (F))
In a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, condenser, and dropping funnel, 193 parts by weight of 2-ethylhexyl acrylate, 6 parts by weight of N, N-diethylacrylamide, nonionic reactive surfactant (Asahi Denka Kogyo Co., Ltd., Adekaria Soap ER-10) 1 part by weight, 2-hydroxyethyl acrylate 8 parts by weight, 2,2′-azobisisobutyronitrile 0.4 parts by weight as a polymerization initiator, ethyl acetate 312 parts by weight were charged, nitrogen gas was introduced while gently stirring, and the polymerization temperature was kept at around 60 ° C. for 5 hours to carry out a polymerization reaction, and an acrylic polymer (F) solution (40% by weight) was obtained. Prepared. This acrylic polymer (F) had Tg = −10 ° C. or less, a weight average molecular weight of 620,000, and an acid value of 0.0.

(Acrylic polymer (G))
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, a cooler, and a dropping funnel, 199.4 parts by weight of 2-ethylhexyl acrylate, a nonionic reactive surfactant (Nippon Yushi Co., Ltd., Bremer PP) -800) 0.6 parts by weight, 2-hydroxyethyl acrylate 8 parts by weight, 2,2′-azobisisobutyronitrile 0.4 part by weight, ethyl acetate 326 parts by weight as a polymerization initiator, and gently stirred While introducing nitrogen gas, the temperature of the liquid in the flask was kept at around 60 ° C. to conduct a polymerization reaction for 5 hours to prepare an acrylic polymer (G) solution (39% by weight). This acrylic polymer (G) had Tg = −10 ° C. or less, a weight average molecular weight of 800,000, and an acid value of 0.0.

<Preparation of ionic liquid (1)>
[Ionic liquid (1)]
A solution obtained by diluting 10 parts by weight of 1-butyl-3-methylpyridinium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) to 20% by weight with distilled water is added to a four-necked flask equipped with a stirring blade, a thermometer, and a condenser. Then, a solution obtained by diluting 19 parts by weight of lithium bis (trifluoromethanesulfone) imide (manufactured by Kishida Chemical Co., Ltd.) to 20% by weight with distilled water was gradually added while rotating the stirring blade. After the addition, stirring was continued at 25 ° C. for 2 hours, and then allowed to stand for 12 hours, and the supernatant was removed to obtain a liquid product.

The obtained liquid product was washed three times with 200 parts by weight of distilled water and dried under an environment of 110 ° C. for 2 hours to obtain 20 parts by weight of an ionic liquid (1) that was liquid at 25 ° C. It was. The obtained ionic liquid (1) is subjected to NMR ( ¹ H, ¹³ C) measurement, FT-IR measurement, and XRF measurement, and identified as 1-butyl-3-methylpyridinium bis (trifluoromethanesulfone) imide. ·confirmed.

<Preparation of antistatic agent>
[Antistatic agent solution (a)]
By diluting 10 parts by weight of cationic surfactant lauryltrimethylammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd., solid at 25 ° C.) with a mixed solvent consisting of 20 parts by weight of ethyl acetate and 20 parts by weight of isopropyl alcohol, An antistatic agent solution (a) (20% by weight) was prepared.

[Antistatic agent solution (b)]
In a four-necked flask equipped with a stirring blade, a thermometer, and a condenser, 0.2 parts by weight of lithium perchlorate, 9.8 parts by weight of polypropylene glycol (diol type, number average molecular weight 2000), and 10 parts by weight of ethyl acetate were added. The mixture was stirred and mixed and stirred for about 2 hours while maintaining the liquid temperature in the flask at around 80 ° C. to prepare an antistatic agent solution (b) (50% by weight).

<Preparation of antistatic treatment film>
Antistatic by diluting 10 parts by weight of an antistatic agent (manufactured by Solvex, Microsolver RMd-142, mainly composed of tin oxide and polyester resin) with a mixed solvent consisting of 30 parts by weight of water and 70 parts by weight of methanol An agent solution was prepared.

  The obtained antistatic agent solution was applied onto a polyethylene terephthalate (PET) film (thickness 38 μm) using a Meyer bar and dried at 130 ° C. for 1 minute to remove the solvent and remove the antistatic layer (thickness). 0.2 μm) to form an antistatic film.

[Example 1]
(Preparation of adhesive composition)
A solution (40% by weight) of the acrylic polymer (A) is diluted to 20% by weight with ethyl acetate, 0.2 parts by weight of the ionic liquid (1) is added to 100 parts by weight of this solution, and hexamethylene diisocyanate as a crosslinking agent. 0.4 part by weight of isocyanurate (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate HX) and 0.4 part by weight of dibutyltin dilaurate (1% by weight ethyl acetate solution) as a crosslinking catalyst were added at about 25 ° C. for about 1 minute. Mixing and stirring were performed to prepare an acrylic pressure-sensitive adhesive solution (1).

(Preparation of adhesive sheet)
The said acrylic adhesive solution (1) was apply | coated to the surface opposite to the antistatic process surface of said antistatic process film, and it heated at 110 degreeC for 3 minute (s), and formed the 20-micrometer-thick adhesive layer. Next, a silicone-treated surface of a polyethylene terephthalate film having a thickness of 25 μm having one surface subjected to silicone treatment was bonded to the surface of the pressure-sensitive adhesive layer to produce a pressure-sensitive adhesive sheet.

[Example 2]
(Preparation of adhesive composition)
The acrylic polymer (C) solution (35% by weight) was diluted with ethyl acetate to 20% by weight, and 100 parts by weight of this solution was added to an aliphatic amine-based ionic liquid (Guangei Chemical Industries, IL-A5, 25). 0.12 parts by weight in liquid form at 0 ° C., 0.4 part by weight of isocyanurate of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate HX) as a crosslinking agent, dibutyltin dilaurate (1% by weight ethyl acetate solution) as a crosslinking catalyst ) 0.4 part by weight was added and mixed and stirred at 25 ° C. for about 1 minute to prepare an acrylic pressure-sensitive adhesive solution (2).

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (2) was used instead of the acrylic pressure-sensitive adhesive solution (1).

Example 3
(Preparation of adhesive composition)
A solution (40% by weight) of the acrylic polymer (D) is diluted to 20% by weight with ethyl acetate, 0.14 parts by weight of the ionic liquid (1) is added to 100 parts by weight of this solution, and hexamethylene diisocyanate as a crosslinking agent. 0.6 part by weight of isocyanurate (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate HX) and 0.4 part by weight of dibutyltin dilaurate (1% by weight ethyl acetate solution) as a crosslinking catalyst were added at about 25 ° C. for about 1 minute. Mixing and stirring were performed to prepare an acrylic pressure-sensitive adhesive solution (3).

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (3) was used instead of the acrylic pressure-sensitive adhesive solution (1).

Example 4
(Preparation of adhesive composition)
An acrylic pressure-sensitive adhesive solution was obtained in the same manner as in Example 3, except that the acrylic polymer (E) solution (40 wt%) was used instead of the acrylic polymer (D) solution (40 wt%). (4) was prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (4) was used instead of the acrylic pressure-sensitive adhesive solution (1).

Example 5
(Preparation of adhesive composition)
A solution (40% by weight) of the acrylic polymer (F) is diluted to 20% by weight with ethyl acetate, 0.2 parts by weight of the ionic liquid (1) is added to 100 parts by weight of this solution, and hexamethylene diisocyanate as a crosslinking agent. 0.6 part by weight of isocyanurate (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate HX) and 0.4 part by weight of dibutyltin dilaurate (1% by weight ethyl acetate solution) as a crosslinking catalyst were added at about 25 ° C. for about 1 minute. Mixing and stirring were performed to prepare an acrylic pressure-sensitive adhesive solution (5).

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (5) was used instead of the acrylic pressure-sensitive adhesive solution (1).

[Comparative Example 1]
(Preparation of adhesive composition)
A solution (40% by weight) of the acrylic polymer (B) is diluted to 20% by weight with ethyl acetate, 0.2 parts by weight of the ionic liquid (1) is added to 100 parts by weight of this solution, and hexamethylene diisocyanate as a crosslinking agent. 0.4 part by weight of isocyanurate (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate HX) and 0.4 part by weight of dibutyltin dilaurate (1% by weight ethyl acetate solution) as a crosslinking catalyst were added at about 25 ° C. for about 1 minute. Mixing and stirring were performed to prepare an acrylic pressure-sensitive adhesive solution (6).

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (6) was used instead of the acrylic pressure-sensitive adhesive solution (1).

[Comparative Example 2]
(Preparation of adhesive composition)
An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 2 except that the acrylic polymer (B) solution (40% by weight) was used instead of the acrylic polymer (C) solution (35% by weight). (7) was prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (7) was used instead of the acrylic pressure-sensitive adhesive solution (1).

[Comparative Example 3]
(Preparation of adhesive composition)
An acrylic pressure-sensitive adhesive solution (8) was prepared in the same manner as in Example 1 except that the ionic liquid (1) was not used.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (8) was used instead of the acrylic pressure-sensitive adhesive solution (1).

[Comparative Example 4]
(Preparation of adhesive composition)
An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Comparative Example 1 except that 1 part by weight of the antistatic agent solution (a) (20% by weight) was used instead of 0.2 part by weight of the ionic liquid (1). (9) was prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (9) was used instead of the acrylic pressure-sensitive adhesive solution (1).

[Comparative Example 5]
(Preparation of adhesive composition)
A solution (40% by weight) of the acrylic polymer (B) is diluted to 20% by weight with ethyl acetate, and 4 parts by weight of the antistatic agent solution (b) (50% by weight) is added to 100 parts by weight of this solution. As a cross-linking catalyst, 0.5 part by weight of trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L) and 0.4 part by weight of dibutyltin dilaurate (1% by weight ethyl acetate solution) were added. Then, an acrylic pressure-sensitive adhesive solution (10) was prepared by mixing and stirring at 25 ° C. for about 1 minute.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (10) was used instead of the acrylic pressure-sensitive adhesive solution (1).

Example 6
(Preparation of adhesive composition)
A solution (39% by weight) of the acrylic polymer (G) is diluted to 20% by weight with ethyl acetate, 0.11 part by weight of the ionic liquid (1) is added to 100 parts by weight of this solution, and hexamethylene diisocyanate as a crosslinking agent. 0.48 parts by weight of an isocyanurate (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate HX) and 0.4 parts by weight of dibutyltin dilaurate (1% by weight ethyl acetate solution) as a crosslinking catalyst were added at 25 ° C. for about 1 minute. Mixing and stirring were performed to prepare an acrylic pressure-sensitive adhesive solution (11).

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (11) was used instead of the acrylic pressure-sensitive adhesive solution (1).

[Comparative Example 6]
(Preparation of adhesive composition)
An acrylic pressure-sensitive adhesive solution (12) was prepared in the same manner as in Example 6 except that the ionic liquid (1) was not used.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (12) was used instead of the acrylic pressure-sensitive adhesive solution (1).

Example 7
(Preparation of adhesive composition)
An acrylic adhesive solution (13) was prepared in the same manner as in Example 1 except that 0.4 parts by weight of the ionic liquid (1) was used instead of 0.2 parts by weight of the ionic liquid (1). Prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (13) was used instead of the acrylic pressure-sensitive adhesive solution (1).

Example 8
(Preparation of adhesive composition)
Instead of 0.2 parts by weight of the ionic liquid (1), 1-ethyl-2,3,5-trimethylpyrazolium bis (trifluoromethanesulfonyl) imide (manufactured by Nippon Carlit Co., Ltd., ILC-402-2, 25 An acrylic pressure-sensitive adhesive solution (14) was prepared in the same manner as in Example 1 except that 0.2 parts by weight of the liquid was used.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (14) was used instead of the acrylic pressure-sensitive adhesive solution (1).

Example 9
(Preparation of adhesive composition)
Instead of 0.2 parts by weight of the ionic liquid (1), 1-propyl-2,3,5-trimethylpyrazolium bis (trifluoromethanesulfonyl) imide (manufactured by Nippon Carlit Co., Ltd., ILC-403-2, 25 An acrylic pressure-sensitive adhesive solution (15) was prepared in the same manner as in Example 1 except that 0.2 parts by weight of the liquid was used.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (15) was used instead of the acrylic pressure-sensitive adhesive solution (1).

Example 10
(Preparation of adhesive composition)
Instead of 0.2 parts by weight of the ionic liquid (1), 1-butyl-2,3,5-trimethylpyrazolium bis (trifluoromethanesulfonyl) imide (manufactured by Nippon Carlit Co., Ltd., ILC-404-2, 25 An acrylic pressure-sensitive adhesive solution (16) was prepared in the same manner as in Example 1 except that 0.2 parts by weight of the liquid was used.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (16) was used instead of the acrylic pressure-sensitive adhesive solution (1).

[Comparative Example 7]
(Preparation of adhesive composition)
An acrylic pressure-sensitive adhesive solution was used in the same manner as in Example 1 except that 1 part by weight of the antistatic agent solution (a) (20% by weight) was used instead of 0.2 part by weight of the ionic liquid (1). (17) was prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the acrylic pressure-sensitive adhesive solution (17) was used instead of the acrylic pressure-sensitive adhesive solution (1).

  About the adhesive sheet obtained by said Example and comparative example, peeling voltage, contamination | pollution property, and adhesive force were evaluated in the following way.

<Measurement of peeling voltage>
The pressure-sensitive adhesive sheet is cut into a size of 70 mm in width and 130 mm in length, the separator is peeled off, and then bonded to an acrylic plate (thickness: 1 mm, width: 70 mm, length: 100 mm) that has been previously neutralized. Nitto Denko Corporation SEG1425EWVAGS2B, width: 70 mm, length: 100 mm) The surface was crimped by a hand roller so that one end protruded 30 mm.

  After leaving for one day in an environment of 23 ° C. × 50% RH, a sample is set at a predetermined position as shown in FIG. 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.

<Evaluation of contamination>
After the pressure-sensitive adhesive sheet is cut into a size of 30 mm in width and 80 mm in length and the separator is peeled off, it is pressure-bonded to a polarizing plate (manufactured by Nitto Denko Corporation, SEG1425DU, width: 70 mm, length: 100 mm) with a hand roller, and an evaluation sample Was made.

The evaluation sample was allowed to stand in an environment of 25 ° C. × 50% RH for 1 month, and then the pressure-sensitive adhesive sheet was peeled from the adherend by hand, and the contamination state of the adherend surface at that time was visually observed. The evaluation criteria are as follows.
・ If no contamination was found: ○
・ If contamination is found: ×

<Adhesion measurement>
A triacetyl cellulose film (Fuji Photo Film Co., Ltd., Fujitack, thickness: 90 μm) was cut into a size of 70 mm in width and 100 mm in length, immersed in an aqueous solution of sodium hydroxide (10% by weight) at 60 ° C. for 1 minute, and then distilled. The adherend was prepared by washing with water.

  The adherend was allowed to stand in an environment of 23 ° C. × 50% RH for 24 hours, and then an adhesive sheet cut to a size of 25 mm in width and 100 mm in length was laminated on the adherend at a pressure of 0.25 MPa, and evaluation was performed. A sample was made.

  After lamination, the laminate was allowed to stand for 30 minutes in an environment of 23 ° C. × 50% RH, and then the adhesive strength when peeled at a peeling speed of 10 m / min and a peeling angle of 180 ° 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.

  According to the results in Table 1 above, when the pressure-sensitive adhesive composition prepared according to the present invention was used (Examples 1 to 10), the stripping voltage to the polarizing plate was suppressed in all the examples, and the polarizing plate was obtained. It became clear that there was no pollution.

  On the other hand, in the case of using a pressure-sensitive adhesive composition that does not contain a reactive surfactant as a monomer unit of the base polymer (Comparative Examples 1 and 2), the stripping voltage is suppressed in any case. However, the occurrence of contamination was observed. Further, in the case of using the pressure-sensitive adhesive composition containing no ionic liquid (Comparative Examples 3 and 6), although no occurrence of contamination is observed, the stripping voltage to the polarizing plate as the adherend is high. It became the result. Further, when a cationic surfactant is used as an antistatic agent (Comparative Examples 4 and 7) and when an alkali metal salt and a polyether polyol are used (Comparative Example 5), the stripping voltage is suppressed. However, contamination was observed. Therefore, in all of the comparative examples, it is impossible to achieve both suppression of the peeling voltage on the polarizing plate as the adherend and suppression of the occurrence of contamination, and the pressure-sensitive adhesive composition for the antistatic pressure-sensitive adhesive sheet is obtained. Became unsuitable.

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

Claims (6)

Ri Na contained with 0.01 to 20% by weight of reactive surfactant as a monomer unit (meth) acrylic polymer, and an ionic liquid,
The reactive surfactant, the adhesive composition, characterized in reactive surfactant der Rukoto containing ethylene oxide groups.   The pressure-sensitive adhesive composition according to claim 1, wherein the ionic liquid is one or more of a nitrogen-containing onium salt, a sulfur-containing onium salt, and a phosphorus-containing onium salt. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the ionic liquid contains one or more cations represented by the following general formulas (A) to (D).
[R _a in the formula (A) represents a hydrocarbon group having 4 to 20 carbon atoms and may include a hetero atom, and R _b and R _c may be the same or different, and may be hydrogen or _C 1 to _C 16. Represents a hydrocarbon group and may contain heteroatoms. However, when the nitrogen atom contains a double bond, there is no R _c . ]
[R _d in the formula (B) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a hetero atom, and R _e , R _f , and R _g may be the same or different and each may represent hydrogen or carbon number. Represents 1 to 16 hydrocarbon groups and may contain heteroatoms. ]
[R _h in the formula (C) represents a hydrocarbon group having 2 to 20 carbon atoms, and may contain a hetero atom, and R _i , R _j , and R _k may be the same or different and represent hydrogen or carbon number. Represents 1 to 16 hydrocarbon groups and may contain heteroatoms. ]
[Z in Formula (D) represents a nitrogen, sulfur, or phosphorus atom, and R ₁ , R _m , R _n , and R _o are the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms. And may contain heteroatoms. However, when Z is a sulfur atom, there is no _Ro . ] The adhesive layer formed by bridge | crosslinking the adhesive composition in any one of Claims 1-3 . Pressure-sensitive adhesive sheet, wherein a pressure-sensitive adhesive layer obtained by crosslinking a pressure-sensitive adhesive composition according to any one of claims 1 to 3, formed on one side or both sides of the support. A pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition according to any one of claims 1 to 3 is formed on one side or both sides on a support made of a plastic substrate subjected to antistatic treatment. Characteristic surface protective film.