JP4562180B2 - 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 shape or a tape shape using the same. The pressure-sensitive adhesive sheets comprising the antistatic pressure-sensitive adhesive composition of the present invention are suitably used for plastic products and the like that are likely to generate static electricity. Especially, 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 pressure-sensitive adhesive tape can be bonded at room temperature by applying a slight pressure for a short time, and is used in various applications for joining various articles. In addition, since the adhesive tape has cohesive force and elasticity, it can be peeled off from a hard, smooth surface while it adheres appropriately, and is also used as a surface protective film. 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 protective film is bonded to an optical member such as a polarizing plate or a wave plate used for a liquid crystal display panel via an adhesive for the purpose of preventing scratches and dirt.

  The surface protective film used for these optical members is generally a separator for the purpose of protecting the adhesive surface. And this separator peels and removes, when bonding a protective film to an optical member. Since the protective film, the pressure-sensitive adhesive, and the separator that constitute the surface protective film are made of a plastic material, they have high electrical insulation and generate static electricity during friction and peeling. Therefore, static electricity is generated when the separator is peeled from the surface protective film. The static electricity causes dust to adhere to the surface protection film, causing a problem of contaminating the optical member. Therefore, various antistatic treatments are applied to the surface protective film in order to prevent such problems.

  For example, a method is disclosed in which a cationic surfactant or the like is added to the pressure-sensitive adhesive, and the surfactant is transferred from the pressure-sensitive adhesive to the adherend to prevent charging (for example, see Patent Document 1). However, this invention is an invention in which a surfactant is bleed on the surface of an adhesive and transferred to an adherend, and when applied to a protective film, contamination of the adherend is inevitable. Therefore, when the adhesive to which a low molecular surfactant is added is applied to the protective film for an optical member, there is a problem of impairing the optical characteristics 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 with this method, bleeding of the antistatic agent is unavoidable, and it has been found that when applied to a surface protective film, contamination of the adherend occurs over time or at high temperatures.
JP-A-9-165460 JP-A-6-128539

  In light of such circumstances, the present invention provides a pressure-sensitive adhesive composition capable of preventing the pressure-sensitive adhesive sheet from being peeled when peeled, and reducing the contamination of the adherend, and an anti-static pressure-sensitive adhesive sheet using the same. It aims at providing a kind and a surface protection film.

  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 is characterized by containing an ionic liquid and a polymer having a glass transition temperature Tg of 0 ° C. or less as a base polymer. Here, the ionic liquid refers to a molten salt (ionic compound) that is liquid at room temperature (25 ° C.).

  According to the present invention, the above ionic liquid acts as an antistatic agent, and by using this ionic liquid, the antistatic agent bleed is suppressed, and the adhesion to the adherend is low even over time and at high temperatures. An agent composition is obtained. Although the details of the reason why bleeding is suppressed by using an ionic liquid are not clear, it is presumed as follows. It is considered that the antistatic effect by the surfactant having a long chain alkyl group or the like is manifested by the surface of the surfactant bleed and the formation of a charge leakage layer with moisture in the air. On the other hand, since the ionic liquid is in a liquid state, the molecular movement is easier than that of the surfactant, and the rearrangement of molecules is likely to occur due to the generation of electric charges. Therefore, in the case of an ionic liquid, since a charge neutralization mechanism by molecular rearrangement works, it is considered that an excellent antistatic effect can be obtained without bleed on the surface as compared with the surfactant. Further, since the ionic liquid is preferably in a liquid state at room temperature, it can be easily added to, dispersed in, or dissolved in the pressure-sensitive adhesive as compared with a solid salt. Further, since the ionic liquid has no vapor pressure (non-volatile), it does not disappear with time and has the characteristics that the antistatic property can be continuously obtained.

  In the above, it is preferable that the ionic liquid is at least one of a nitrogen-containing onium salt, a sulfur-containing onium salt, and a phosphorus-containing onium salt. In particular, the ionic liquid preferably contains one or more cations represented by the following general formulas (A) to (D). An ionic liquid having these cations provides a further excellent antistatic ability.

［式（Ａ）中のＲ₁は、炭素数４から２０の炭化水素基を表し、ヘテロ原子を含んでも良く、Ｒ₂およびＲ₃は、同一又は異なって、水素または炭素数１から１６の炭化水素基を表し、ヘテロ原子を含んでも良い。但し、窒素原子が２重結合を含む場合、Ｒ_３はない。］
［式（Ｂ）中のＲ₄は、炭素数２から２０の炭化水素基を表し、ヘテロ原子を含んでも良く、Ｒ₅、Ｒ₆、およびＲ₇は、同一又は異なって、水素または炭素数１から１６の炭化水素基を表し、ヘテロ原子を含んでも良い。］
［式（Ｃ）中のＲ₈は、炭素数２から２０の炭化水素基を表し、ヘテロ原子を含んでも良く、Ｒ₉、Ｒ₁₀、およびＲ₁₁は、同一又は異なって、水素または炭素数１から１６の炭化水素基を表し、ヘテロ原子を含んでも良い。］
［式（D）中のXは、窒素、硫黄、又はリン原子を表し、Ｒ₁₂、Ｒ₁₃、Ｒ₁₄、およびＲ₁₅は、同一又は異なって、炭素数１から２０の炭化水素基を表し、ヘテロ原子を含んでも良い。但しＸが硫黄原子の場合、Ｒ₁₂はない。］
また、ガラス転移温度Ｔｇが０℃以下のポリマーが、炭素数１〜１４のアルキル基を有すアクリレートおよび／またはメタクリレートの１種以上を主成分とするアクリルポリマーであることが好ましい。これらのアクリルポリマーにより、イオン性液体との相溶性のバランスが良好になり、粘着特性も十分維持することができる。

[R ₁ in the formula (A) represents a hydrocarbon group having 4 to 20 carbon atoms and may contain a hetero atom, and R ₂ and R ₃ may be the same or different and each may be hydrogen or 1 to 16 carbon atoms. It represents a hydrocarbon group and may contain a hetero atom. However, when the nitrogen atom contains a double bond, there is no R ₃ . ]
[R ₄ in the formula (B) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a hetero atom, and R ₅ , R ₆ , and R ₇ 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 ₈ in Formula (C) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a hetero atom, and R ₉ , R ₁₀ , and R ₁₁ may be the same or different and each may represent hydrogen or carbon number. Represents 1 to 16 hydrocarbon groups and may contain heteroatoms. ]
[X in the formula (D) represents a nitrogen, sulfur, or phosphorus atom, and R ₁₂ , R ₁₃ , R ₁₄ , and R ₁₅ are the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms. , And may contain a heteroatom. However, when X is a sulfur atom, there is no R ₁₂ . ]
In addition, the polymer having a glass transition temperature Tg of 0 ° C. or lower is preferably an acrylic polymer mainly composed of one or more of acrylates and / or methacrylates having an alkyl group having 1 to 14 carbon atoms. These acrylic polymers provide a good balance of compatibility with the ionic liquid and can sufficiently maintain the adhesive properties.

  On the other hand, the pressure-sensitive adhesive sheets of the present invention have a pressure-sensitive adhesive layer containing any one of the pressure-sensitive adhesive compositions described above on one side or both sides of a support. According to the pressure-sensitive adhesive sheets of the present invention, since the pressure-sensitive adhesive composition of the present invention having the above-described effects is used, the pressure-sensitive adhesive sheet can be prevented from being charged when peeled, and the contamination to the adherend can be reduced. Adhesive sheets.

  On the other hand, the surface protective film of the present invention is characterized by having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition as described above on one side or both sides of a support. According to the surface protective film of the present invention, since the pressure-sensitive adhesive composition of the present invention having the above-described effects is used, the surface protective film can be prevented from being charged when peeled, and the contamination to the adherend is reduced. A possible surface protection film can be obtained.

  The pressure-sensitive adhesive composition of the present invention comprises an ionic liquid and a polymer having a glass transition temperature Tg of 0 ° C. or lower as a base polymer. The ionic liquid refers to a molten salt (ionic compound) that is liquid at room temperature (25 ° C.).

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

［式（Ａ）中のＲ₁は、炭素数４から２０の炭化水素基を表し、ヘテロ原子を含んでも良く、Ｒ₂およびＲ₃は、同一又は異なって、水素または炭素数１から１６の炭化水素基を表し、ヘテロ原子を含んでも良い。但し、窒素原子が２重結合を含む場合、Ｒ_３はない。］
［式（Ｂ）中のＲ₄は、炭素数２から２０の炭化水素基を表し、ヘテロ原子を含んでも良く、Ｒ₅、Ｒ₆、およびＲ₇は、同一又は異なって、水素または炭素数１から１６の炭化水素基を表し、ヘテロ原子を含んでも良い。］
［式（Ｃ）中のＲ₈は、炭素数２から２０の炭化水素基を表し、ヘテロ原子を含んでも良く、Ｒ₉、Ｒ₁₀、およびＲ₁₁は、同一又は異なって、水素または炭素数１から１６の炭化水素基を表し、ヘテロ原子を含んでも良い。］
［式（D）中のXは、窒素、硫黄、又はリン原子を表し、Ｒ₁₂、Ｒ₁₃、Ｒ₁₄、およびＲ₁₅は、同一又は異なって、炭素数１から２０の炭化水素基を表し、ヘテロ原子を含んでも良い。但しＸが硫黄原子の場合、Ｒ₁₂はない。］
式（Ａ）で表されるカチオンとしてはピリジニウムカチオン、ピペリジニウムカチオン、ピロリジニウムカチオン、ピロリン骨格を有すカチオン、ピロール骨格を有すカチオンなどが挙げられる。具体例としては、１−エチルピリジニウムカチオン、１−ブチルピリジニウムカチオン、１−へキシルピリジニウムカチオン、１−ブチル−３−メチルピリジニウムカチオン、１−ブチル−４−メチルピリジニウムカチオン、１−へキシル−３−メチルピリジニウムカチオン、１−ブチル−３，４−ジメチルピリジニウムカチオン、１，１−ジメチルピロリジニウムカチオン、１−エチル−１−メチルピロリジニウムカチオン、１−メチル−１−プロピルピロリジニウムカチオン、２−メチル−１−ピロリンカチオン、１−エチル−２−フェニルインドールカチオン、１，２−ジメチルインドールカチオン、１−エチルカルバゾールカチオンが挙げられる。

[R ₁ in the formula (A) represents a hydrocarbon group having 4 to 20 carbon atoms and may contain a hetero atom, and R ₂ and R ₃ may be the same or different and each may be hydrogen or 1 to 16 carbon atoms. It represents a hydrocarbon group and may contain a hetero atom. However, when the nitrogen atom contains a double bond, there is no R ₃ . ]
[R ₄ in the formula (B) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a hetero atom, and R ₅ , R ₆ , and R ₇ 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 ₈ in Formula (C) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a hetero atom, and R ₉ , R ₁₀ , and R ₁₁ may be the same or different and each may represent hydrogen or carbon number. Represents 1 to 16 hydrocarbon groups and may contain heteroatoms. ]
[X in the formula (D) represents a nitrogen, sulfur, or phosphorus atom, and R ₁₂ , R ₁₃ , R ₁₄ , and R ₁₅ are the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms. , And may contain a heteroatom. However, when X is a sulfur atom, there is no R ₁₂ . ]
Examples of the cation represented by the formula (A) include a pyridinium cation, a piperidinium cation, a pyrrolidinium cation, a cation having a pyrroline skeleton, and a cation having a pyrrole skeleton. Specific examples include 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, 1-hexyl-3. -Methylpyridinium cation, 1-butyl-3,4-dimethylpyridinium cation, 1,1-dimethylpyrrolidinium cation, 1-ethyl-1-methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidinium cation 2-methyl-1-pyrroline cation, 1-ethyl-2-phenylindole cation, 1,2-dimethylindole cation, and 1-ethylcarbazole cation.

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

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

  Examples of the cation represented by the formula (D) include a tetraalkylammonium cation, a trialkylsulfonium cation, a tetraalkylphosphonium cation, and those in which a part of the alkyl group is substituted with an alkenyl group.

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

  Among them, triethylmethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyltrimethylammonium cation, N, N-dimethyl-N- Ethyl-N-propylammonium cation, N, N-dimethyl-N-ethyl-N-butylammonium cation, N, N-dimethyl-N-ethyl-N-pentylammonium cation, N, N-dimethyl-N-ethyl- N-hexylammonium cation, N, N-dimethyl-N-ethyl-N-heptylammonium cation, N, N-dimethyl-N-ethyl-N-nonylammonium cation, N, N-dimethyl-N-propyl-N- Butylan Nium cation, N, N-dimethyl-N-propyl-N-pentylammonium cation, N, N-dimethyl-N-propyl-N-hexylammonium cation, N, N-dimethyl-N-propyl-N-heptylammonium cation N, N-dimethyl-N-butyl-N-hexylammonium cation, N, N-dimethyl-N-butyl-N-heptylammonium cation, N, N-dimethyl-N-pentyl-N-hexylammonium cation, trimethyl Heptylammonium cation, N, N-diethyl-N-methyl-N-propylammonium cation, N, N-diethyl-N-methyl-N-pentylammonium cation, N, N-diethyl-N-methyl-N-heptylammonium Cation, N, N-diethyl-N-propyl Pyr-N-pentylammonium cation, triethylmethylammonium cation, triethylpropylammonium cation, triethylpentylammonium cation, triethylheptylammonium cation, N, N-dipropyl-N-methyl-N-ethylammonium cation, N, N-dipropyl- N-methyl-N-pentylammonium cation, N, N-dipropyl-N-butyl-N-hexylammonium cation, N, N-dibutyl-N-methyl-N-pentylammonium cation, N, N-dibutyl-N- Asymmetric tetraalkylammonium such as methyl-N-hexylammonium cation, trioctylmethylammonium cation, N-methyl-N-ethyl-N-propyl-N-pentylammonium cation Asymmetric tetraalkylphosphonium cations such as trialkylsulfonium cations such as nium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation and dimethyldecylsulfonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation and trimethyldecylphosphonium cation are preferably used. .

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

  Specific examples of the ionic liquid used in the present invention are appropriately selected from the combination of the cation component and the anion component, and include 1-butylpyridinium tetrafluoroborate, 1-butylpyridinium hexafluorophosphate, 1-butyl- 3-methylpyridinium tetrafluoroborate, 1-butyl-3-methylpyridinium trifluoromethanesulfonate, 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide, 1-butyl-3-methylpyridinium bis (pentafluoroethanesulfonyl) ) Imido, 1-hexylpyridinium tetrafluoroborate, 2-methyl-1-pyrroline tetrafluoroborate, 1-ethyl-2-phenylindole tetrafluoroborate, 1,2-dimethyli Dole tetrafluoroborate, 1-ethylcarbazole tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium trifluoroacetate, 1-ethyl-3-methylimidazolium heptafluorobutyrate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium perfluorobutanesulfonate, 1-ethyl-3-methylimidazolium di Cyanamide, 1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-ethyl-3-methylimidazolium bis (pentafluoroethanesulfonyl) imide, 1-ethyl 3-methylimidazolium tris (trifluoromethanesulfonyl) imide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium trifluoro Acetate, 1-butyl-3-methylimidazolium heptafluorobutyrate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium perfluorobutanesulfonate, 1-butyl-3-methylimidazole Bis (trifluoromethanesulfonyl) imide, 1-hexyl-3-methylimidazolium bromide, 1-hexyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate, 1-octyl-3-methylimidazolium tetrafluoroborate, 1-octyl- 3-methylimidazolium hexafluorophosphate, 1-hexyl-2,3-dimethylimidazolium tetrafluoroborate, 1,2-dimethyl-3-propylimidazolium bis (trifluoromethanesulfonyl) imide, 1-methylpyrazolium Tetrafluoroborate, 3-methylpyrazolium tetrafluoroborate, tetrahexylammonium bis (trifluoromethanesulfonyl) imide, diallyldimethylammonium tetrafluoroborate, diary Dimethylammonium trifluoromethanesulfonate, diallyldimethylammonium bis (trifluoromethanesulfonyl) imide, diallyldimethylammonium bis (pentafluoroethanesulfonyl) imide, 1-butylpyridinium (trifluoromethanesulfonyl) trifluoroacetamide, 1-butyl-3-methylpyridinium (Trifluoromethanesulfonyl) trifluoroacetamide, 1-ethyl-3-methylimidazolium (trifluoromethanesulfonyl) trifluoroacetamide, diallyldimethylammonium (trifluoromethanesulfonyl) trifluoroacetamide, N, N-dimethyl-N-ethyl-N -Propylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl- -Ethyl-N-butylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N- Xylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-nonylammonium bis (trifluoromethane) Sulfonyl) imide, N, N-dimethyl-N, N-dipropylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-butylammonium bis (trifluoromethanesulfonyl) imide, N, N - Tyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl- N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-butyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-butyl-N-heptylammonium bis ( Trifluoromethanesulfonyl) imide, N, N-dimethyl-N-pentyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N, N-dihexylammonium bis (trifluoromethanesulfonate) ) Imide, trimethylheptylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-propylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-pentylammonium Bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) Imide, triethylpropylammonium bis (trifluoromethanesulfonyl) imide, triethylpentylammonium bis (trifluoromethanesulfonyl) imide, triethylheptylammonium bis (tri Fluoromethanesulfonyl) imide, N, N-dipropyl-N-methyl-N-ethylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N-butyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N, N-dihexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dibutyl-N -Methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dibutyl-N-methyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, trioctylmethylammonium bis (trifluoro) B) imide, etc. N- methyl -N- ethyl -N- propyl -N- pentyl ammonium bis (trifluoromethanesulfonyl) imide.

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

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

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

水酸化物法は、（４）〜（８）に示すような反応によって行われる方法である。まずハロゲン化物（Ｒ_４ＮＸ）をイオン交換膜法電解（反応式（４））、ＯＨ型イオン交換樹脂法（反応式（５））または酸化銀（Ａｇ_２Ｏ）との反応（反応式（６））で水酸化物（Ｒ_４ＮＯＨ）を得る。（ハロゲンとしては塩素、臭素、ヨウ素が用いられる）得られた水酸化物を上記ハロゲン化法と同様に反応式（７）〜（８）の反応を用いて目的とするイオン性液体（Ｒ_４ＮＡ）が得られる。

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

酸エステル法は、（９）〜（１１）に示すような反応によって行われる方法である。まず３級アミン（Ｒ_３Ｎ）を酸エステルと反応させて酸エステル物を得る。（反応式（９）、酸エステルとしては、硫酸、亜硫酸、りん酸、亜りん酸、炭酸などの無機酸のエステルやメタンスルホン酸、メチルホスホン酸、蟻酸などの有機酸のエステルなどが用いられる）得られた酸エステル物を上記ハロゲン化法と同様に反応式（１０）〜（１１）の反応の用いて目的とするイオン性液体（Ｒ_４ＮＡ）が得られる。また、酸エステルとしてメチルトリフルオロメタンスルホネート、メチルトリフルオロアセテートなどを用いることにより、直接イオン性液体を得ることもできる。

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

錯形成法は、（１２）〜（１５）に示すような反応によって行われる方法である。まず４級アンモニウムのハロゲン化物（Ｒ_４ＮＸ）、４級アンモニウムの水酸化物（Ｒ_４ＮＯＨ）、４級アンモニウムの炭酸エステル化物（Ｒ_４ＮＯＣＯ_２ＣＨ_３）などをフッ化水素（ＨＦ）やフッ化アンモニウム（ＮＨ_４Ｆ）と反応させてフッ化４級アンモニウム塩を得る。（反応式（１２）〜（１４））得られたフッ化４級アンモニウム塩をＢＦ_３，ＡｌＦ_３，ＰＦ_５，ＡＳＦ_５，ＳｂＦ_５，ＮｂＦ_５，ＴａＦ_５などのフッ化物と錯形成反応により、イオン性液体を得ることができる。（反応式（１５））

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

中和法は、（１６）に示すような反応によって行われる方法である。３級アミンとＨＢＦ_４，ＨＰＦ_６，ＣＨ_３ＣＯＯＨ，ＣＦ_３ＣＯＯＨ，ＣＦ_３ＳＯ_３Ｈ，（ＣＦ_３ＳＯ_２）_２ＮＨ，（ＣＦ_３ＳＯ_２）_３ＣＨ，（Ｃ_２Ｆ_５ＳＯ_２）_２ＮＨなどの有機酸とを反応させることにより得ることができる。

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.

上記記載のＲは、水素または炭素数１から２０の炭化水素基を表し、ヘテロ原子を含んでも良い。

R described above 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. Part is preferable, 0.03 to 20 parts by weight is more preferable, and 0.05 to 10% by weight is most preferable. If it is less than 0.01 part by weight, sufficient antistatic properties cannot be obtained, and if it exceeds 40 parts by weight, the contamination of the adherend tends to increase.

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

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

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

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

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

  As other components, the Tg is 0 ° C. or lower (usually −100 ° C. or higher) for the reason that it is easy to balance the adhesive performance, and the sulfonic acid group-containing monomer, phosphoric acid group-containing monomer, and cyano group-containing monomer , Vinyl ester, aromatic vinyl compound and other cohesive strength / heat resistance improving components, carboxyl group-containing monomer, acid anhydride group-containing monomer, hydroxyl group-containing monomer, amide group-containing monomer, amino group-containing monomer, epoxy group-containing A component having a functional group that functions as an adhesive strength improvement or crosslinking base point, such as a monomer, N-acryloylmorpholine, and vinyl ethers, can be used. Other components can be used alone or in combination of two or more.

  However, when an acrylate and / or methacrylate having an acid functional group such as a carboxyl group, a sulfonic acid group, or a phosphoric acid group is used, it is preferable to adjust the acid value of the acrylic polymer to be 29 or less. When the acid value of the acrylic polymer exceeds 29, the antistatic property tends to deteriorate. The adjustment of the acid value can be adjusted by the blending amount of the acrylate and / or methacrylate having an acid functional group. For example, an acrylic polymer obtained by copolymerizing 2-ethylhexyl acrylate and acrylic acid can be used as the acrylic polymer having a carboxyl group. In this case, the acid value can be satisfied by adjusting acrylic acid to 3.7 parts by weight or less with respect to 100 parts by weight of the total amount of 2-ethylhexyl acrylate and acrylic acid.

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

  An example of the cyano group-containing monomer is acrylonitrile. Examples of vinyl esters include vinyl acetate.

  An example of the aromatic vinyl compound is styrene. Examples of the carboxyl group-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of the acid anhydride group-containing monomer include maleic anhydride and itaconic anhydride.

  As hydroxyl group-containing monomers, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl acrylate, N-methylol (meth) acrylamide, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4 -Hydroxybutyl vinyl ether, diethylene glycol monovinyl ether and the like.

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

  Examples of vinyl ethers include vinyl ethyl ether. The acrylic polymer can be obtained by a polymerization method generally used as a synthesis method of an acrylic polymer such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization.

  The pressure-sensitive adhesive of the present invention can obtain pressure-sensitive adhesive sheets having further excellent heat resistance by appropriately crosslinking a base polymer, particularly an acrylic polymer. As specific means of the crosslinking method, a compound having a group capable of reacting with a carboxyl group, a hydroxyl group, an amino group, an amide group, or the like appropriately included in an acrylic polymer such as a polyisocyanate compound, an epoxy compound, or an aziridine compound as a crosslinking base point There is a method of using a so-called cross-linking agent to add and react. Of these, polyisocyanate compounds and epoxy compounds are particularly preferably used.

  Examples of the polyisocyanate compound include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate, 2,4-tolylene diisocyanate, Aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate and xylylene diisocyanate, trimethylolpropane / tolylene diisocyanate trimer adduct (trade name Coronate L), trimethylolpropane / hexamethylene diisocyanate trimer adduct ( Product name Coronate HL), isocyanurate of hexamethylene diisocyanate (Product name Coronate HX) Urethane Industry Co., Ltd.] and the like isocyanate adducts such as. Examples of the epoxy compound include N, N, N ′, N′-tetraglycidyl-m-xylenediamine (trade name: TETRAD-X) and 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane (trade name: TETRAD- C) [all manufactured by Mitsubishi Gas Chemical Co., Ltd.]. These crosslinking agents are used alone or in a mixture of two or more. The amount of the crosslinking agent to be used is appropriately selected depending on the balance with the acrylic polymer to be crosslinked and, further, depending on the intended use as the pressure-sensitive adhesive sheet.

  In order to obtain sufficient heat resistance by the cohesive strength of the acrylic pressure-sensitive adhesive, it is generally preferable to add 0.5 parts by weight or more with respect to 100 parts by weight of the acrylic polymer. Moreover, it is preferable to mix | blend at 10 weight part or less with respect to 100 weight part of said acrylic polymers from the point of a softness | flexibility and adhesiveness.

  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 reactivity is used. In general, those having 10 or less radiation-reactive unsaturated bonds are preferably used. Two or more polyfunctional monomers can be used in combination.

  Specific examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6 hexanediol di ( And (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, divinylbenzene, N, N′-methylenebisacrylamide and the like.

  The amount of the polyfunctional monomer used is appropriately selected depending on the balance with the acrylic polymer to be crosslinked, and further depending on the intended use as an adhesive sheet. In general, in order to obtain sufficient heat resistance by the cohesive strength of the acrylic pressure-sensitive adhesive, it is preferably blended at 0.1 to 30 parts by weight with respect to 100 parts by weight of the acrylic polymer. Moreover, it is more preferable to mix | blend at 10 weight part or less with respect to 100 weight part of acrylic polymers from the point of a softness | flexibility and adhesiveness.

  Examples of the radiation include ultraviolet rays, laser rays, α rays, β rays, γ rays, x rays, electron rays, and the like, and ultraviolet rays are preferably used from the viewpoints of controllability, good handleability, and cost. More preferably, ultraviolet rays having a wavelength of 200 to 400 nm are used. Ultraviolet rays can be irradiated using an appropriate light source such as a high-pressure mercury lamp, a microwave excitation lamp, or a chemical lamp. In addition, when using an ultraviolet-ray as a radiation, a photoinitiator is added to an acrylic adhesive.

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

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

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

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

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

  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. I can do it.

  The pressure-sensitive adhesive sheets of the present invention are various supports comprising a plastic film such as a polyester film and a porous material such as paper and nonwoven fabric so that the pressure-sensitive adhesive has a thickness of usually 3 to 100 μm, preferably about 5 to 50 μm. It is applied and formed on one or both sides of the body 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. Polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene / propylene Polymer, ethylene 1-butene copolymer, ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyl alcohol copolymer and other polyolefin films, polyethylene terephthalate, polyethylene naphthalate, polybutylene Polyester film such as terephthalate, polyacrylate film, polystyrene film, nylon 6, nylon 6,6, polyamide film such as partially aromatic polyamide, polyvinyl chloride film, polyvinylidene chloride film, polycarbonate Irumu 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, 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. As a method for forming and applying the pressure-sensitive adhesive, known methods used for the production of pressure-sensitive adhesive tapes are used. Specific examples include roll coating, gravure coating, reverse coating, roll brushing, spray coating, and air knife coating.

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

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

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

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

[Acid value]
The acid value was measured using an automatic titrator COM-550 manufactured by Hiranuma Sangyo Co., Ltd., and obtained from the following formula. A = {(Y−X) × f × 5.611} / M
A: Acid value, Y: Titration volume of sample solution (ml), X: Titration volume of 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-propanolic potassium hydroxide solution (manufactured by Wako Pure Chemical Industries, Ltd., for petroleum product neutralization value test), electrode: glass electrode; GE-101, comparative electrode; RE-201 Measurement mode: Petroleum product neutralization number test 1.

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

[Glass-transition temperature]
The glass transition temperature Tg (° C.) was determined by the following formula using the following literature values as the glass transition temperature Tgn (° C.) of the homopolymer of each monomer.
Formula: 1 / Tg = Σ (Wn / Tgn)
[Wherein Tg (K) is the glass transition temperature of the copolymer, Wn (−) is the weight fraction of each monomer, Tgn (K) is the glass transition temperature of the homopolymer of each monomer, and n is the type of each monomer. Represents. ]
2-ethylhexyl acrylate: -70 ° C
2-hydroxyethyl acrylate: -15 ° C
Butyl acrylate: -55 ° C
Acrylic acid: 106 ° C
Production Example 1 (acrylic polymer A)
200 g of 2-ethylhexyl acrylate, 8 g of 2-hydroxyethyl acrylate,
A mixture of 0.4 g of 2,2′-azobisisobutyronitrile and 312 g of ethyl acetate was reacted in a nitrogen stream at 65 ° C. for 6 hours to obtain a Tg = −68 ° C., a weight average molecular weight of 500,000 and an acid value of 0. An acrylic polymer solution (40% by weight) was obtained.

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

Production Example 3 (Allyl Polymer C)
A mixture of 200 g of 2-ethylhexyl acrylate, 8 g of acrylic acid, 0.4 g of 2,2′-azobisisobutyronitrile and 312 g of ethyl acetate was reacted in a nitrogen stream at 65 ° C. for 6 hours to obtain Tg = −66 ° C. An acrylic polymer solution (40% by weight) having a weight average molecular weight of 540,000 and an acid value of 30 was obtained.

Production Example 4 (acrylic polymer D)
A mixture of 200 g of 2-ethylhexyl acrylate, 0.1 g of 1-hydroxycyclohexyl phenyl ketone [Irgacure 184 manufactured by Ciba Specialty Chemicals Co., Ltd.] and 0.1 g of benzyldimethyl ketal [Irgacure 651 manufactured by Ciba Specialty Chemicals Co., Ltd.] in a nitrogen stream Then, UV irradiation was performed with a high-pressure mercury lamp to obtain a partial polymer having a polymerization rate of 10% (weight average molecular weight 2.2 million, acid value 0).

Production Example 5 (Antistatic Agent A)
A mixture of 0.2 g of lithium perchlorate (melting point 236 ° C.) and 9.8 g of polypropylene glycol (diol type, number average molecular weight 2,000) was diluted with 10 g of ethyl acetate to prepare an antistatic agent solution (50% by weight). did.

Production Example 6 (Antistatic Agent B)
10 parts by weight of cationic surfactant lauryltrimethylammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd., solid at 25 ° C.) is diluted with 20 parts by weight of ethyl acetate and 20 parts by weight of isopropyl alcohol to obtain an antistatic agent solution (20% by weight). ) Was produced.

Example 1 (Preparation of pressure-sensitive adhesive composition)
The acrylic polymer A solution (40 wt%) obtained in Production Example 1 was diluted to 20 wt% with ethyl acetate, and 100 g of this solution was diluted with 1-butyl-3-methylpyridinium trifluoromethanesulfonate (25 ° C.) as an ionic liquid. 0.1 g of hexamethylene diisocyanate (coronate HX manufactured by Nippon Polyurethane Industry Co., Ltd.) and 0.4 g of dibutyltin dilaurate (1% by weight ethyl acetate solution) were added as a crosslinking catalyst. An acrylic pressure-sensitive adhesive solution was prepared.

(Preparation of adhesive sheet)
The acrylic pressure-sensitive adhesive solution was applied to one side of a polyethylene terephthalate film and heated at 110 ° C. for 3 minutes to form a pressure-sensitive adhesive layer having a thickness of 20 μm. Next, a silicone-treated surface of a 25 μm-thick polyethylene terephthalate film with one surface subjected to silicone treatment was bonded to the surface of the pressure-sensitive adhesive layer to prepare a pressure-sensitive adhesive sheet.

Example 2 (Preparation of pressure-sensitive adhesive composition)
An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 1 except that 2.0 g of diallyldimethylammonium bis (trifluoromethanesulfonyl) imide (liquid at 25 ° C.) was used as the ionic liquid.

(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 prepared above was used as the acrylic pressure-sensitive adhesive solution.

Example 3 (Preparation of pressure-sensitive adhesive composition)
The acrylic polymer B solution (25 wt%) obtained in Production Example 2 was diluted to 20 wt% with ethyl acetate, and 100 g of this solution was diluted with 1-butyl-3-methylpyridinium trifluoromethanesulfonate (25 ° C.) as an ionic liquid. 0.1 g of trimethylolpropane / tolylene diisocyanate trimer adduct (Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd.), dibutyltin dilaurate (1 wt% ethyl acetate solution) as a crosslinking catalyst .6 g was added to prepare an acrylic adhesive solution.

(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 prepared above was used as the acrylic pressure-sensitive adhesive solution.

Example 4 (Preparation of pressure-sensitive adhesive composition)
The acrylic polymer C solution (40% by weight) obtained in Production Example 3 was diluted to 20% by weight with ethyl acetate, and diallyldimethylammonium bis (trifluoromethanesulfonyl) imide (at 25 ° C.) was added to 100 g of this solution as an ionic liquid. 2.0 g of liquid, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane (TETRAD-C manufactured by Mitsubishi Gas Chemical Co., Ltd.) 0.7 g, trimethylolpropane / tolylene diisocyanate trimer added The product (Japan Polyurethane Industry Co., Ltd. Coronate L) 0.3g was added, and the acrylic adhesive solution 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 prepared above was used as the acrylic pressure-sensitive adhesive solution.

Example 5 (Preparation of pressure-sensitive adhesive composition)
To 100 g of the partial polymer obtained in Production Example 4, 0.2 g of 1-butyl-3-methylpyridinium trifluoromethanesulfonate (liquid at 25 ° C.), 1.5 g of trimethylolpropane triacrylate, benzyldimethyl ketal [Ciba -Specialty Chemicals Irgacure 651] 0.1g was added and the acrylic adhesive solution was prepared.

(Preparation of adhesive sheet)
The acrylic pressure-sensitive adhesive solution was applied to one side of a polyethylene terephthalate film so as to have a thickness of 20 μm, and a 25 μm-thick silicone-treated polyethylene terephthalate film was further covered thereon. This sheet was irradiated with ultraviolet rays so as to obtain an illuminance of 37 mW / cm ² and a light amount of 660 mJ / cm ² with a high-pressure mercury lamp, to prepare an adhesive sheet.

Example 6 (Preparation of pressure-sensitive adhesive composition)
An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 1 except that 0.1 g of 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide (liquid at 25 ° C.) was used as the ionic liquid.

(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 prepared above was used as the acrylic pressure-sensitive adhesive solution.

Comparative Example 1
An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 1 except that no ionic liquid was added. A surface protective film having a thickness of 20 μm was prepared in the same manner as in Example 1 except that this acrylic adhesive solution was used as the acrylic adhesive solution.

Comparative Example 2
An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 3 except that no ionic liquid was added. A surface protective film having a thickness of 20 μm was prepared in the same manner as in Example 1 except that this acrylic adhesive solution was used as the acrylic adhesive solution.

Comparative Example 3
An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 4 except that no ionic liquid was added. A surface protective film having a thickness of 20 μm was prepared in the same manner as in Example 1 except that this acrylic adhesive solution was used as the acrylic adhesive solution.

Comparative Example 4
An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 5 except that no ionic liquid was added. A surface protective film having a thickness of 20 μm was prepared in the same manner as in Example 1 except that this acrylic adhesive solution was used as the acrylic adhesive solution.

Comparative Example 5
An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 1 except that 4.0 g of the antistatic agent A solution (50% by weight) of Production Example 5 was used instead of the ionic liquid. A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that this acrylic pressure-sensitive adhesive solution was used as the acrylic pressure-sensitive adhesive solution.

Comparative Example 6
In Example 1, an acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 1 except that 10 g of the antistatic agent B solution (20% by weight) of Production Example 6 was used instead of the ionic liquid. A pressure-sensitive adhesive sheet having a thickness of 20 μm was prepared in the same manner as in Example 1 except that this acrylic pressure-sensitive adhesive solution was used as the acrylic pressure-sensitive adhesive solution.

Reference example 1
An acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 1 except that 8.0 g of 1-butyl-3-methylpyridinium trifluoromethanesulfonate (liquid at 25 ° C.) was added as the ionic liquid. A surface protective film having a thickness of 20 μm was prepared in the same manner as in Example 1 except that this acrylic adhesive solution was used as the acrylic adhesive solution.

  About the adhesive sheet obtained in said Examples 1-5, Comparative Examples 1-6, and Reference Example 1, the stripping voltage, the contamination | pollution property, and adhesive force were evaluated in the following ways.

[Peeling voltage]
The pressure-sensitive adhesive sheet is cut into a size having a width of 70 mm and a length of 100 mm, and placed on a sample fixing base as shown in FIG. One end of the separator is fixed to an automatic winder and peeled so that a peeling angle is 150 ° and a peeling speed is 10 m / min. The potential of the pressure-sensitive adhesive surface 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.

[Contamination]
A 80 μm thick triacetyl cellulose film (Fuji Photo Film Co., Ltd., Fujitac) was cut to a width of 70 mm and a length of 100 mm, immersed in an aqueous solution of sodium hydroxide (10% by weight) at 60 ° C. for 1 minute, and then distilled water. To prepare an adherend. After the above adherend is left in an environment of 23 ° C. × 50% RH for one day, an adhesive sheet cut to a size of 70 mm in width and 100 mm in length is attached by hand so that air bubbles are mixed between the adherend and the adherend. Together, an evaluation sample was prepared. After being left in a 50 ° C. environment for one day, left in a 23 ° C. × 50% RH environment for 2 hours, and then the adhesive sheet is peeled off from the adherend by hand to visually check the state of contamination on the adherend surface. And observed. The evaluation criteria were ○ when no contamination was observed and × when contamination was observed.

[Adhesion measurement]
A 80 μm thick triacetyl cellulose film (Fuji Photo Film Co., Ltd., Fujitac) was cut to a width of 70 mm and a length of 100 mm, immersed in an aqueous solution of sodium hydroxide (10% by weight) at 60 ° C. for 1 minute, and then distilled water. To prepare an adherend. The above adherend was allowed to stand for 1 day in an environment of 23 ° C. × 50% RH, and then used as an adherend for adhesive force evaluation. The pressure-sensitive adhesive sheet cut to a size of 25 mm in width and 80 mm in length was laminated on the adherend for evaluation with a pressure of 0.25 MPa to prepare an evaluation sample. After leaving the laminate for 30 minutes, the adhesive strength when peeled at a peeling speed of 30 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.

上記表１の結果から明らかなように、本発明の実施例１〜６の粘着シートは、いずれも比較例１〜４のイオン性液体を含まない粘着シートと比べ、粘着力をほとんど維持しながら、剥離帯電圧が抑制されている。また、本発明の実施例１〜６の粘着シートは、いずれも比較例５〜６と比べ汚染性が認められない。したがって、実施例１〜６の粘着剤組成物は、帯電防止性と低汚染性に優れる粘着剤組成物であることが分かる。

As is clear from the results of Table 1 above, the pressure-sensitive adhesive sheets of Examples 1 to 6 of the present invention all maintain the adhesive force as compared with the pressure-sensitive adhesive sheets that do not contain the ionic liquid of Comparative Examples 1 to 4. The stripping voltage is suppressed. Moreover, as for the adhesive sheet of Examples 1-6 of this invention, all are not contaminated compared with Comparative Examples 5-6. Therefore, it turns out that the adhesive composition of Examples 1-6 is an adhesive composition excellent in antistatic property and low pollution property.

  In particular, in Comparative Example 6, since a surfactant having a long chain alkyl group is used, bleeding occurs and the adhesive strength is reduced. Also in Comparative Example 5, the effect of preventing bleeding by complexing an alkali metal salt is It was not enough.

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

Claims (5)

An ionic liquid and a base polymer containing a polymer having a glass transition temperature Tg of 0 ° C. or lower,
The base polymer is an acrylic polymer;
The acid value of the acrylic polymer state, and are 29 or less,
The ionic liquid is selected from the group consisting of 1-butyl-3-methylpyridinium trifluoromethanesulfonate, diallyldimethylammonium bis (trifluoromethanesulfonyl) imide, and 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide. At least Tanedea Rukoto surface protective film pressure-sensitive adhesive composition characterized chosen. The surface protective film according to claim 1, wherein the polymer having a glass transition temperature Tg of 0 ° C. or less is an acrylic polymer mainly composed of at least one of acrylate and / or methacrylate having an alkyl group having 1 to 14 carbon atoms. Pressure-sensitive adhesive composition. Furthermore, it contains a crosslinking agent,
The pressure-sensitive adhesive composition for a surface protective film according to claim 1 or 2 , wherein the crosslinking agent is at least one selected from the group consisting of a polyisocyanate compound, an epoxy compound, and an aziridine compound. A pressure-sensitive adhesive sheet for a surface protective film, comprising a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition for a surface protective film according to claim 1 or 3 on one side or both sides of a support. A surface protective film comprising a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition for a surface protective film according to claim 1 or 3 on one side or both sides of a support.

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