JP2011127130A - Adhesive composition and adhesive sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antistatic adhesive composition excellent in reliable adhesiveness, and adhesive layers and adhesive sheets using the same. <P>SOLUTION: The adhesive composition includes (a) an ionic liquid, (b) a (meth)acrylic polymer the main ingredients of which are one or more (meth)acrylate(s) having a 4C-12C alkyl group, and (c) a compound (compound (c)) having two or more hydroxyl groups in a molecule, wherein the (meth)acrylic polymer has a weight average molecular weight of 300,000-1,300,000. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a pressure-sensitive adhesive composition having antistatic properties and antistatic pressure-sensitive adhesive sheets made into a sheet-like or tape-like form using the same. More specifically, the present invention relates to an antistatic pressure-sensitive adhesive composition and an antistatic pressure-sensitive adhesive sheet that can exhibit good cohesive force and have excellent adhesion reliability.

The pressure-sensitive adhesive sheets made of the pressure-sensitive adhesive composition of the present invention are suitably used for plastic products and the like that easily generate static electricity. Especially, it is useful as an antistatic pressure-sensitive adhesive sheet and pressure-sensitive adhesive tape used in applications that dislike static electricity such as electronic devices.

Double-sided adhesive tapes are used in various industrial fields such as home appliances, automobiles, and office automation equipment as joining means with good workability and high adhesive property reliability. In particular, in recent years, the double-sided adhesive tape is frequently used in the electronic / electric field.

In general, in a double-sided tape, a release sheet (or a separator or the like) is bonded to the surface of the pressure-sensitive adhesive layer for the purpose of protecting the pressure-sensitive adhesive layer. In particular, in electronic applications where cleanliness is required, a plastic film is used as a release sheet.

These plastic materials such as plastic films have high electrical insulation, and generate static electricity during friction and peeling. Therefore, charging occurs when the release sheet is peeled from the adhesive tape, and the adhesive tape is charged. When these charged adhesive tapes are used for fixing electronic components, electrostatic damage of the electronic components occurs. Therefore, it is necessary to prevent static electricity from the adhesive tape, and attempts have been made to impart antistatic properties to the adhesive.

As the above-mentioned attempt, for example, a method of adding one or more surfactants to an adhesive and transferring the surfactant from the adhesive to an adherend to prevent charging is disclosed (for example, Patent Documents). 1). However, in this method, the surfactant is likely to bleed onto the surface of the pressure-sensitive adhesive, and when applied to a pressure-sensitive adhesive tape, there is a concern that the reliability of adhesion to the adherend may be reduced. 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, as an antistatic adhesive sheet, a method of providing an antistatic resin layer in an intermediate layer of an adhesive layer is disclosed (for example, see Patent Document 2). However, in this method, since the pressure-sensitive adhesive sheet has a three-layer structure, there is a concern that the manufacturing process becomes complicated and the productivity is low. Furthermore, it cannot be said that the adhesion between the intermediate layer and the other layers is sufficient, and the adhesion reliability at each interface is still insufficient.

JP-A-9-165460 Japanese Patent Laid-Open No. 10-138409

In light of such circumstances, an object of the present invention is to provide an antistatic pressure-sensitive adhesive composition having excellent adhesion reliability, and a pressure-sensitive adhesive layer and pressure-sensitive adhesive sheets 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) an ionic liquid, (b) a (meth) acrylic polymer whose main component is at least one (meth) acrylate having an alkyl group having 4 to 12 carbon atoms. And (c) a compound containing two or more hydroxyl groups in the molecule (referred to as compound (c)).

According to the pressure-sensitive adhesive composition of the present invention, as shown in the results of the examples, an ionic liquid and a (meth) acryl having, as a main component, one or more kinds of (meth) acrylates having an alkyl group having 4 to 12 carbon atoms. The pressure-sensitive adhesive layer that is crosslinked with the system polymer and the compound (c) containing two or more hydroxyl groups in the molecule has excellent antistatic properties and adhesion reliability when peeled. Become. Although the details of the reason why the crosslinked product of the pressure-sensitive adhesive composition exhibits such characteristics are not clear, the ionic liquid is more compatible with the base polymer than the surfactant, etc. It is presumed that excellent antistatic properties and adhesive reliability stopping properties are realized side by side due to the suppression of adhesion and the improvement of cohesive strength by the compound (c) obtained in a well-balanced manner.

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

The pressure-sensitive adhesive composition of the present invention is characterized by using the above ionic liquid as an antistatic agent. Since the above ionic liquid is liquid 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.

The (meth) acrylic polymer in the present invention refers to an acrylic polymer and / or a methacrylic polymer. The (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 . ]

Moreover, in the adhesive composition of this invention, it is preferable that the isocyanate compound is further contained. By including such an isocyanate compound, the crosslinking reaction is promoted, and a better cohesive force can be obtained.

Furthermore, in this invention, it is preferable that the compound (c) which contains a 2 or more hydroxyl group in the above-mentioned molecule | numerator contains a nitrogen atom in a molecule | numerator. By using such a compound (c), when a crosslinking agent such as an isocyanate compound is used, the crosslinking reaction with the hydroxyl group (hydroxyl group) of the compound (c) is facilitated, and a better cohesive force can be obtained. Can do.

Moreover, in the adhesive composition of this invention, it is preferable that tackifying resin is further contained. By using such a tackifier resin in combination, a pressure-sensitive adhesive composition having more excellent adhesion reliability to the adherend can be obtained.

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

The pressure-sensitive adhesive sheet of the present invention is characterized in that a pressure-sensitive adhesive layer formed 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 it has a pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition having the above-described effects, the anti-static pressure-sensitive adhesive sheet has excellent cohesive force and adhesion reliability. It will be like.

Schematic configuration diagram of potential measurement unit used for measurement of peeling voltage in Example

The pressure-sensitive adhesive composition of the present invention comprises (a) an ionic liquid, (b) a (meth) acrylic polymer mainly comprising at least one (meth) acrylate having an alkyl group having 4 to 12 carbon atoms, and (C) a compound containing two or more hydroxyl groups in the molecule.

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

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-methyl-1-ethylpyrrolidinium 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-propyl -1-pentylpiperidinium cation, 1-propyl-1-hexylpiperidinium cation, 1-propyl-1-heptylpiperidinium cation, 1,1-dibutylpiperidinium cation, 1-butyl-1-pentyl Piperidinium cation, 1-butyl-1-hexylpiperidinium Cations, 1-butyl-1-heptylpiperidinium cation, 2-methyl-1-pyrroline cation, 1-ethyl-2-phenylindole cation, 1,2-dimethylindole cation, 1-ethylcarbazole cation and the like. .

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 1-hexadecyl-3-methylimidazolium cation, 1-octadecyl-3-methylimidazolium cation, 1,2-dimethyl-3-propylimidazolium cation, 1-ethyl-2,3-dimethylimidazolium cation 1-butyl-2, -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-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-tetra Chill-1,4-dihydropyrimidinium cation, such as 1,2,3,4-tetramethyl-1,6-dihydropyrimidinium cation.

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

Specific examples include 1-methylpyrazolium cation, 3-methylpyrazolium cation, 1-ethyl-2-methylpyrazolinium cation and the like.

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, tetrapropylammonium cation, tetrabutylammonium cation, tetrapentylammonium cation, tetrahexylammonium cation, tetraheptylammonium cation, triethylmethylammonium cation, tributylethylammonium Cation, trimethyldecyl ammonium cation, trioctyl methyl ammonium cation, tripentyl butyl ammonium cation, trihexyl methyl ammonium cation, trihexyl pentyl ammonium cation, triheptyl methyl ammonium cation, tripentyl butyl ammonium cation, triheptyl hexyl ammonium cation Dimethyldihexylammonium cation, dipropyldihexylammonium cation, heptyldimethylhexylammonium cation, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyltrimethylammonium cation, diallyldimethylammonium cation, N , N-dimethyl-N, N-dipropylammonium 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-dimethyl-N-ethyl-N-nonylammonium cation, N, N-dimethyl-N-propyl-N-butylammonium cation, N, N-dimethyl-N-propyl-N-pentylammonium cation, N, N -Dimethyl-N-propyl-N-hexylammonium cation, N, N-dimethyl-N-propyl-N-heptylammonium 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, trimethylheptylammonium cation, N, N-diethyl-N-methyl-N-propylammonium cation, N, N-diethyl-N-methyl-N-pentylan Monium cation, N, N-diethyl-N-methyl-N-heptylammonium cation, N, N-diethyl-N-propyl-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-hexyl Ammonium cation, N, N-dipropyl-N, N-dihexylammonium cation, N, N-dibutyl-N-methyl-N-pentylammonium cation, N, N-dibutyl-N-methyl-N-hexy Ammonium cation, N, N-dimethyl-N, N-dihexylammonium cation, trioctylmethylammonium cation, N-methyl-N-ethyl-N-propyl-N-pentylammonium cation, trimethylsulfonium cation, triethylsulfonium cation, tributyl Sulfonium cation, trihexylsulfonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, tetramethylphosphonium cation, tetraethylphosphonium cation, tetrabutylphosphonium cation, tetrapentylphosphonium cation, tetrahexylphosphonium cation, phosphonium cation, Tetraheptylphosphonium cation, te La octyl phosphonium cation, triethyl methyl phosphonium cation, tributyl ethyl phosphonium cation, and a trimethyl decyl phosphonium cation.

Among them, tetramethylammonium cation, tetraethylammonium cation, tetrapropylammonium cation, tetrabutylammonium cation, tetrapentylammonium cation, tetrahexylammonium cation, tetraheptylammonium cation, triethylmethylammonium cation, tributylethylammonium cation, trimethyldecyl Ammonium cation, trioctylmethylammonium cation, tripentylbutylammonium cation, trihexylmethylammonium cation, trihexylpentylammonium cation, triheptylmethylammonium cation, tripentylbutylammonium cation, triheptylhexylammonium cation, dimethyldihexan Silammonium cation, dipropyldihexylammonium cation, heptyldimethylhexylammonium cation, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyltrimethylammonium cation, diallyldimethylammonium 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 Ru-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-dimethyl-N-butyl-N-hexylammonium cation, N, N-dimethyl-N-butyl-N-heptylammonium cation, N, N-dimethyl-N- Pentyl-N-hexylammonium 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 carbonate Thion, N, N-diethyl-N-propyl-N-pentylammonium cation, N, N-dimethyl-N, N-dihexylammonium 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-dipropyl-N, N-dihexylammonium cation, N, N-dibutyl-N-methyl-N-pentylammonium cation, N, N-dibutyl-N-methyl-N-hexylammonium cation ON, trioctylmethylammonium cation, N-methyl-N-ethyl-N-propyl-N-pentylammonium cation, etc. tetraalkylammonium cation, trimethylsulfonium cation, triethylsulfonium cation, tributylsulfonium cation, trihexylsulfonium cation, diethyl Trialkylsulfonium cations such as methylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, tetramethylphosphonium cation, tetraethylphosphonium cation, tetrabutylphosphonium cation, tetrapentylphosphonium cation, tetrahexylphosphonium cation, tetraheptylphosphonium cation, tetra Octylphospho Umukachion, triethyl methyl phosphonium cation, tributyl ethyl phosphonium cation, tributyl ethyl phosphonium cation, such as tetraalkylphosphonium cations such as trimethyl decyl phosphonium 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. Specifically, 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 ^- it 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 (pentafluoroethanesulfonyl) imide, 1-hexylpyridinium tetrafluoroborate, 1,1-dimethylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-ethylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-propylpyrrolidinium bis (trifluoromethanesulfonyl) i 1-methyl-1-butylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-pentylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-hexylpyrrolidinium bis ( Trifluoromethanesulfonyl) imide, 1-methyl-1-heptylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1,1-diethylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-propylpyrrolidinium Bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-butylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-pentylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1- Xylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-heptylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1,1-dipropylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-propyl -1-butylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-propyl-1-pentylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-propyl-1-hexylpyrrolidinium bis (trifluoromethanesulfonyl) imide 1-propyl-1-heptylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1,1-dibutylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-propylpiperidinium bis (tri Fluoromethanesulfonyl) imide, 1-pentylpiperidinium bis (trifluoromethanesulfonyl) imide, 1,1-dibutylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-ethylpiperidinium bis (trifluoromethane) Sulfonyl) 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-diethylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-propylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-butylpiperidinium bis (trifluoromethanesulfonyl) imide 1-ethyl-1-pentylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-hexylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-heptylpiperidinium bis (trifluoro) Lomethanesulfonyl) imide, 1,1-dipropylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-propyl-1-butylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-propyl-1-pentyl Peridinium bis (trifluoromethanesulfonyl) imide, 1-propyl-1-hexylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-propyl-1-heptylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-propylpi Peridinium bis (trifluoromethanesulfonyl) imide, 1-pentylpiperidinium bis (trifluoromethanesulfonyl) imide, 1,1-dibutylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-propylpyrrolidinium bis (pentafluoro Methanesulfonyl) imide, 1-pentylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1,1-dimethylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1-methyl Ru-1-ethylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1-methyl-1-propylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1-methyl-1-butylpyrrolidinium bis (pentafluoro Methanesulfonyl) imide, 1-methyl-1-pentylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1-methyl-1-hexylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1-methyl-1-heptyl Pyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1,1-diethylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1-ethyl-1-propylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1- Ethyl-1 Butylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1-ethyl-1-pentylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1-ethyl-1-hexylpyrrolidinium bis (pentafluoromethanesulfonyl) imide 1-ethyl-1-heptylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1,1-dipropylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1-propyl-1-butylpyrrolidinium bis ( Pentafluoromethanesulfonyl) imide, 1-propyl-1-pentylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1-propyl-1-hexylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1-propyl 1-heptylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1,1-dibutylpyrrolidinium bis (pentafluoromethanesulfonyl) imide, 1-propylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1-pentyl Piperidinium bis (pentafluoromethanesulfonyl) imide, 1,1-dimethylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1-methyl-1-ethylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1- Methyl-1-propylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1-methyl-1-butylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1-methyl-1-pentylpiperidinium bis (penta Fluoromethanesulfonyl) imide, 1-methyl-1-hexylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1-methyl-1-heptylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1,1-diethylpi Peridinium bis (pentafluoromethanesulfonyl) imide, 1-ethyl-1-propylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1-ethyl-1-butylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1 -Ethyl-1-pentylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1-ethyl-1-hexylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1-ethyl-1-heptylpiperidinium bis (pentaful) Romethanesulfonyl) imide, 1,1-dipropylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1-propyl-1-butylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1-propyl-1-pentylpi Peridinium bis (pentafluoromethanesulfonyl) imide, 1-propyl-1-hexylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1-propyl-1-heptylpiperidinium bis (pentafluoromethanesulfonyl) imide, 1 , 1-dibutylpiperidinium bis (pentafluoromethanesulfonyl) imide, 2-methyl-1-pyrroline tetrafluoroborate, 1-ethyl-2-phenylindole tetrafluoroborate, 1,2-dimethylindoletetraf Oroborate, 1-ethylcarbazole tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 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 dicyanamide, 1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-ethyl-3-methylimidazolium bis (pen Tafluoroethanesulfonyl) imide, 1-ethyl-3-methylimidazolium tris (trifluoromethanesulfonyl) methide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium trifluoroacetate, 1-butyl-3-methylimidazolium heptafluorobutyrate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium perfluoro Butanesulfonate, 1-butyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-hexyl-3-methylimidazolium bromide, 1-hexyl-3-methylimidazolium Rholide, 1-hexyl-3-methylimidazolium tetrafluoroborate, 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 (trifluoro (Romethanesulfonyl) imide, 1-methylpyrazolium tetrafluoroborate, 3-methylpyrazolium tetrafluoroborate, N, N-dimethyl-N-ethyl-N-propylammonium bis (trifluoromethanes Phonyl) 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 (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N -Ethyl-N-nonylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N, N-dipropylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-butylammonium Bis (trifluoro Methanesulfonyl) 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 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 (trifluoromethanesulfonyl) imide, trimethylheptylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-propylammonium bis (trifluoromethanesulfonyl) imide, N, N Diethyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-propyl- N-pentylammonium bis (trifluoromethanesulfonyl) imide, triethylpropylammonium bis (trifluoromethanesulfonyl) imide, triethylpentylammonium bis (trifluoromethanesulfonyl) imide, triethylheptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl -N-methyl-N-ethylammonium bis (trifluoromedansulfonyl) imide, N, N-dipropyl-N-methyl-N-pentylammonium (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, tetrahexylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium tetrafluoroborate, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl) imide, Diallyldimethylammonium tetrafluoroborate, diallyldimethylammonium trifluoromethanesulfonate, diallyldimethylammonium bis (trifluoromethanesulfonyl) imi , Diallyldimethylammonium bis (pentafluoroethanesulfonyl) imide, glycidyltrimethylammonium trifluoromethanesulfonate, glycidyltrimethylammonium bis (trifluoromethanesulfonyl) imide, glycidyltrimethylammonium bis (pentafluoroethanesulfonyl) imide, diallyldimethylammonium (trifluoromethanesulfonyl) ) Trifluoroacetamide, glycidyltrimethylammonium (trifluoromethanesulfonyl) trifluoroacetamide, diallyldimethylammonium bis (pentafluoroethanesulfonyl) imide, diallyldimethylbis (pentafluoroethanesulfonyl) imide, 1-octyl-3-methylimidazolium chloride 1-deci -3-methylimidazolium chloride, 1-dodecyl-3-methylimidazolium chloride, 1-tetradodecyl-3-methylimidazolium chloride, 1-hexadodecyl-3-methylimidazolium chloride, 1-hexyl-2,3 -Dimethylimidazolium bromide, 1-hexyl-2,3-dimethylimidazolium chloride, 1-butylpyridinium trifluoromethanesulfonate, 1-hexylpyridinium bromide, 1-hexylpyridinium chloride and the like.

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 can be obtained. In general, however, it is described in the document “Ionic liquids: the forefront and future of development” (issued by CMC Publishing). As described, a halide method, a hydroxide method, an acid ester method, a complex formation method, a neutralization method, and the like 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).

The obtained halide is an acid (HA) or salt having the anion structure (A ⁻ ) of the target ionic liquid (MA and M form a salt with the target anion such as ammonium, lithium, sodium, potassium, etc.) The target ionic liquid (R ₄ NA) is obtained by reacting with a cation).

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. Esters and esters of organic acids such as methanesulfonic acid, methylphosphonic acid and formic acid are used).

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 a complex formation reaction of the obtained quaternary ammonium fluoride salt 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 described in the above (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 generally 0.01 to 40 weights with respect to 100 weight parts of the base polymer. Part is preferable, 0.03 to 30 parts by weight is more preferable, and 0.05 to 20 parts by weight is most preferable. If the amount is less than 0.01 parts by weight, sufficient antistatic properties cannot be obtained, and if it exceeds 40 parts by weight, the adhesive force to the adherend tends to decrease.

As the (meth) acrylic polymer used in the present invention, a (meth) acrylic polymer having at least one (meth) acrylate having a C 4-12 alkyl group as a main component is used.

Specific examples of the (meth) acrylate having an alkyl group having 4 to 12 carbon atoms include, for example, n-butyl (meth) acrylate, s-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) Examples include acrylate, isodecyl (meth) acrylate, n-undecyl (meth) acrylate, and n-dodecyl (meth) acrylate.

The (meth) acrylate having an alkyl group having 4 to 12 carbon atoms described above may be used alone or in combination of two or more, but the total content is (meth) acrylic. The content is preferably 50 to 98% by weight, more preferably 70 to 97.5% by weight, and particularly preferably 85 to 97% by weight, based on all monomer components of the system polymer. If the (meth) acrylate is less than 50% by weight, good adhesive force and holding force required as pressure-sensitive adhesive sheets may not be obtained.

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 cross-linking 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, isocyanate group-containing monomers, vinyl ethers, etc. A component having a functional group that serves as a cyclization base, an olefin, a polyfunctional monomer, and a (meth) acrylate having a C 1-3 alkyl group, a (meth) acrylate having a C 13-18 alkyl group, And (meth) acrylate having an alicyclic alkyl group as appropriate It is possible to have. Other components can be used alone or in combination of two or more.

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, isocrotonic acid, and glycidyl (meth) acrylic acid. And methyl glycidyl (meth) acrylic 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, N-methylol (meth) acrylamide, vinyl alcohol, allyl alcohol, 2-hydroxyethyl Examples thereof include vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether and the like.

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 include amide, N, N′-methylenebisacrylamide, N, N-dimethylaminopropyl acrylamide, N, N-dimethylaminopropyl methacrylamide, and diacetone acrylamide.

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 the isocyanate group-containing monomer include 2-methacryloyloxyethyl isocyanate.

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

Examples of olefins include ethylene, butadiene, vinyl chloride and the like.

Examples of the polyfunctional monomer include triethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Examples include 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, and divinylbenzene.

Examples of the (meth) acrylate having an alkyl group having 1 to 3 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and the like.

Examples of the (meth) acrylate having an alkyl group having 13 to 18 carbon atoms include tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, and the like.

Examples of the (meth) acrylate having an alicyclic alkyl group include cyclohexyl (meth) acrylate, bornyl (meth) acrylate, and isobornyl (meth) acrylate.

The other polymerizable monomer components described above may be used alone or in combination of two or more, but the total content is the total amount of the (meth) acrylic polymer. It is preferable that it is 0.5-49.9 weight% in a body component, 1-49 weight% is more preferable, 2-48 weight% is especially preferable. 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 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, suspension polymerization, and UV polymerization. Among these, the solution polymerization method is preferable from the viewpoint of the balance of adhesive properties such as adhesive strength and holding power and cost. Moreover, the polymer obtained may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

As a polymerization initiator used at the time of solution polymerization, for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′- Azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2, 4,4-trimethylpentane), dimethyl-2,2′-azobis (2-methylpropionate), 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [2- ( 5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis ( , N′-dimethyleneisobutylamidine), 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (Wako Pure Chemical Industries, Ltd., VA-057). Agent, persulfate such as potassium persulfate, ammonium persulfate, di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butylperoxydicarbonate, t -Butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutyl Peroxy-2-ethylhexanoate, di (4-methylbenzoyl) peroxide, diben Yl peroxide, t-butyl peroxyisobutyrate, 1,1-di (t-hexylperoxy) cyclohexane, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxide benzoate Peroxide-based initiation such as milperoxide, 1,1-bis (t-hexylperoxy) -3,3,5-cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, hydrogen peroxide Agents, combinations of persulfates and sodium bisulfite, redox initiators combining peroxides and reducing agents, such as combinations of peroxides and sodium ascorbate, etc., but are not limited to these. It is not a thing. Of these, oil-soluble initiators such as azo initiators and peroxide initiators are preferable.

The polymerization initiator may be used alone or in combination of two or more, but the total content is 0.01 to 1 part by weight with respect to 100 parts by weight of the monomer. Is preferably about 0.03 to 0.8 parts by weight.

In the present invention, a chain transfer agent may be used in the polymerization. By using a chain transfer agent, the molecular weight of the (meth) acrylic polymer can be appropriately adjusted.

Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, 2,3-dimercapto-1-propanol, and α-methylstyrene dimer. It is done.

These chain transfer agents may be used alone or as a mixture of two or more, but the total content is 0.01 to 15 parts by weight with respect to 100 parts by weight of the monomer. About a part.

As a solvent (solvent) used at the time of superposition | polymerization, a general solvent can be used suitably. For example, ethyl acetate, toluene, n-butyl acetate, n-hexane, cyclohexane, methyl ethyl ketone, methyl isobutyl ketone and the like can be mentioned. These solvents may be used alone or in combination of two or more.

The (meth) acrylic polymer used in the present invention has a weight average molecular weight of 300,000 to 1.3 million, preferably 350,000 to 850,000, and more preferably 400,000 to 800,000. When the weight average molecular weight is less than 300,000, the adhesive force required as an adhesive may not be sufficiently obtained. On the other hand, when the weight average molecular weight exceeds 1.3 million, problems such as poor coating due to an increase in the viscosity of the pressure-sensitive adhesive may occur. 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 -20 degrees C or less is used as a base polymer, it is preferable that it is -80 degreeC--25 degreeC, -70 degreeC- More preferably, it is -35 degreeC. When the glass transition temperature is higher than −20 ° C., the polymer is difficult to flow and the wetting to the polarizing plate becomes insufficient, and good pressure-sensitive adhesiveness may not be obtained. 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. In addition, the glass transition temperature (Tg) of a (meth) acrylic-type polymer can be adjusted in the said range by changing suitably the monomer component to be used and those composition ratios.

Moreover, in the adhesive composition of this invention, the compound (c) which contains a 2 or more hydroxyl group in a molecule | numerator is contained.

Here, examples of the compound (c) include aliphatic polyols, alicyclic polyols, aromatic polyols, polyether polyols, polyester polyols, acrylic polyols, polyurethane polyols, polycaprolactone polyols, and polycarbonate polyols. it can.

More specifically, for example, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,3-propanediol, 1,6-hexanediol 1,2-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol 2,2-dimethyl-1,3-propanediol, 2,2′-bis (4-hydroxycyclohexyl) propane, polycaprolactone diol, polycarbonate diol, 1,2,3-propanetriol, 1,2, 6-hexanetriol, 1,2,3-benzenetriol, 1,2,4-benzenetriol, estriol, polycaprolac Ntriol, N, N, N, N-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N, N-tetrakis (2-hydroxypropyl) ethylenediamine PO (polypropylene oxide) adduct, 1,1,2, 2-tetrakis (4-hydroxyphenyl) ethane, 1,1,2,2-tetrakis (4-hydroxy-3-methylphenyl) ethane, 1,1,2,2-tetrakis (4-hydroxy-2,5- Dimethylphenyl) ethane, 1,1,2,2-tetrakis (4-hydroxy-3,5-dimethylphenyl) ethane, 1,1,2,2-tetrakis (5-t-butyl-4-hydroxy-2-) Methylphenyl) ethane, 1,1,5,5-tetrakis (4-hydroxyphenyl) pentane, α, α, α ′, α′-tetrakis (4-H Droxyphenyl) -p-xylene, α, α, α ′, α′-tetrakis (4-hydroxy-3-methylphenyl) -p-xylene, α, α, α ′, α′-tetrakis (2-hydroxy) -5-methylphenyl) -p-xylene, α, α, α ', α'-tetrakis (4-hydroxy-2,5-dimethylphenyl) -p-xylene, α, α, α', α'-tetrakis (4-Hydroxy-3,5-dimethylphenyl) -p-xylene, α, α, α ′, α′-tetrakis (4,5-dihydroxy-2-dimethylphenyl) -p-xylene, α, α, α Examples include ', α-tetrakis (4-hydroxyphenyl) -α, α'-dimethyl-p-xylene.

The compound (c) is preferably used in an amount of 0.01 to 10 parts by weight, more preferably 0.015 to 9 parts by weight, with respect to 100 parts by weight of the (meth) acrylic polymer as the base polymer. More preferably, it is 0.02 to 8 parts by weight. When the amount is less than 0.01 part by weight, the required crosslinking effect cannot be obtained, and the cohesive force is insufficient. When the amount is more than 10 parts by weight, the cohesive force is excessive, and the adhesive force is reduced. These compounds may be used alone or in combination of two or more.

In addition, as said compound (c), it is still more preferable to use the compound which contains a nitrogen atom in a molecule | numerator from the point which can further raise a crosslinking promotion effect.

Examples of the compound (c) containing a nitrogen atom in the molecule include a polyhydroxyalkylamine compound, a polyoxyethylene condensate of ethylenediamine, a polyoxypropylene condensate of ethylenediamine, and a polyoxyethylene-polyoxypropylene condensate of ethylenediamine. Examples thereof include polyoxyalkylene condensates of alkylene diamines, dialcohol amines, trialcohol amines, and the like.

Examples of the polyoxyalkylene condensate include N, N, N ′, N′-tetrakis (2-hydroxyethyl) ethylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N ′, N′-tetrakis (2-hydroxyethyl) trimethylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) trimethylenediamine and the like can be mentioned, among these Can be preferably used.

Examples of dialcohol amines include diethanolamine, dipropanolamine, diisopropanolamine, N-methyldiethanolamine, N-methyldiisopropanolamine, N-ethyldiethanolamine, N-ethyldiisopropanolamine, N-butyldiethanolamine, N- Examples thereof include butyl diisopropanolamine.

Examples of the trialcoholamines include triethanolamine, tripropanolamine, and triisopropanolamine.

Furthermore, in the pressure-sensitive adhesive composition of the present invention, a tackifying resin can be added. By using the tackifier resin, a pressure-sensitive adhesive composition having further excellent adhesion reliability to the adherend is obtained.

As the tackifier resin, a known tackifier resin that can be added to the pressure-sensitive adhesive composition is appropriately used. Examples of the tackifying resin include a terpene tackifying resin, a phenol tackifying resin, and a rosin tackifying resin.

Examples of terpene-based tackifier trees include terpene resins such as α-pinene polymers, β-pinene polymers, and dipentene polymers, and modified terpene resins (phenol modified, aromatic modified, hydrogenated modified). From among terpene tackifying resins such as modified terpene resins (for example, terpene phenol resins, styrene modified terpene resins, aromatic modified terpene resins, hydrogenated terpene resins, etc.) Those having at least one polar group in the molecule can be used.

Examples of phenolic tackifier resins include condensates of various phenols (eg, phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcin, etc.) and formaldehyde (eg, alkylphenolic resins, xyleneformaldehyde). Rosin (unmodified rosin, modified resin), resole obtained by addition reaction of the phenols and formaldehyde with an alkali catalyst, novolak obtained by condensation reaction of the phenols and formaldehyde with an acid catalyst, and the like. Among phenolic tackifying resins such as rosin-modified phenolic resin obtained by adding phenol to rosin and various rosin derivatives with an acid catalyst and thermal polymerization, those having at least one polar group in the molecule Can be used Kill.

Examples of rosin-based tackifying resins include unmodified rosins such as gum rosin, wood rosin, tall oil rosin (raw rosin), and modified rosins modified by hydrogenation, disproportionation, polymerization, etc. of these unmodified rosins ( In addition to hydrogenated rosin, disproportionated rosin, polymerized rosin and other chemically modified rosins), at least one rosin-based tackifying resin such as various rosin derivatives in the molecule. Those having a polar group can be used.

Examples of the rosin derivative include rosin ester compounds obtained by esterifying unmodified rosin with alcohols, and modified rosins obtained by esterifying modified rosins such as hydrogenated rosin, disproportionated rosin and polymerized rosin with alcohols. Ester compounds and other rosin esters; powdered rosins and modified rosins (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.) modified with unsaturated fatty acids; unsaturated rosin-modified rosins; Unmodified rosin, modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.), unsaturated fatty acid modified rosins and unsaturated fatty acid modified rosin esters Reduced rosin alcohols; unmodified rosin, modified rosin and various rosin derivatives Rosins such body (in particular, rosin esters) such as metal salts of thereof.

Among the above-mentioned tackifying resins used in the present invention, those containing a polar group can be suitably used. The polar group in the above is a hydroxyl group, a carboxyl group, an amino group, a mercapto group, an epoxy group, a carbodiimide group, an isocyanate group, a urethane bond or a urea bond, preferably a hydroxyl group or a carboxyl group, and more preferably a hydroxyl group. Examples of polar group-containing tackifying resins include rosin-based and phenol-based resins. Among them, terpene phenol-based, phenol-based, alkylphenol-based, rosin-modified phenol-based, xylene-based and the like can be used as those containing hydroxyl groups. .

The compounding amount of the tackifying resin is usually preferably 1 to 100 parts by weight, more preferably 3 to 80 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer as the base polymer. More preferably, it is 5 to 60 parts by weight. These tackifier resins may be used alone or in combination of two or more.

In the pressure-sensitive adhesive composition of the present invention, pressure-sensitive adhesive sheets having further excellent heat resistance can be obtained by appropriately crosslinking a (meth) acrylic polymer. Specific means of the crosslinking method include carboxyl group, hydroxyl group, amino group, amide group and the like appropriately included in (meth) acrylic polymer such as isocyanate compound, epoxy compound, melamine resin, aziridine compound as crosslinking point There is a method using a so-called crosslinking agent in which a compound having a reactive 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.), trimethylol Propane / hexamethylene diisocyanate trimer adduct (trade name Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), hexamethylene diisocyanate Isocyanurate of (Nippon Polyurethane Industry Co., Ltd., trade name: Coronate HX), and the like, such as isocyanate adducts such as. 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-diglycidyl). Aminomethyl) cyclohexane (trade name: TETRAD-C, manufactured by Mitsubishi Gas Chemical Company, Inc.). 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 by the cohesive strength 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 (meth) acrylic polymer. More preferably, the content is 0.02 to 10 parts by weight. 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 groups 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 the 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 viewpoint 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 layer.

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, and trichlor 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 ethylthioxanthone 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.

Further, the pressure-sensitive adhesive composition used in the pressure-sensitive adhesive sheet of the present invention includes other tackifiers, surface lubricants, leveling agents, release modifiers, plasticizers, softeners, antioxidants, corrosion inhibitors, and anti-aging agents. , Light stabilizers, ultraviolet absorbers, polymerization inhibitors, silane coupling agents, inorganic or organic fillers, powders such as metal powders, dyes, pigments, particles, foils, and the like. These additives can be added as appropriate according to the application for which they are used. In addition, all of these addition amounts may be normal amounts applied to the (meth) acrylic pressure-sensitive adhesive (pressure-sensitive adhesive). These compounds may be used alone or in combination of two or more.

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 sheets of the present invention are 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 for 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 removed 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 the pressure-sensitive adhesive composition is coated on a support film to produce pressure-sensitive adhesive sheets, 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 coated on the support film. You may add to.

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

The pressure-sensitive adhesive sheets of the present invention have various pressure-sensitive adhesive layers such as a plastic film such as a polyester film and a porous material such as paper and nonwoven fabric so that the thickness of the pressure-sensitive adhesive layer is usually about 5 to 1000 μm, preferably about 10 to 200 μm. It is applied and formed on one side or both sides of the support 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 or film. For example, polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, polybutadiene film , Polyolefin films such as polymethylpentene film, ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyl alcohol copolymer, Polyester film such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyacrylate film, polyurethane film, polystyrene film, nylon 6, nylon 6,6, poly, such as partially aromatic polyamide Bromide films, polyvinyl chloride film, a vinyl chloride copolymer film, a polyvinylidene chloride film, polycarbonate film, polyurethane film.

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

For plastic substrates, silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based 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.

In the pressure-sensitive adhesive sheets of the present invention, a separator (or a release liner, a release sheet, etc.) 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 Such as a polyurethane film, 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-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based 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.

<Measurement of molecular weight>
The molecular weight was measured using a GPC apparatus (HLC-8220 GPC, manufactured by Tosoh Corporation). The measurement conditions are as follows.

Sample concentration: 0.2 wt% (THF solution)
Sample injection volume: 10 μl
Eluent: THF
Flow rate: 0.6 ml / min
Measurement temperature: 40 ° C
column:
Sample column;
TSKguardcolumn SuperHZ-H (1) + TSKgel SuperHZM-H (2)
Reference column;
TSKgel SuperH-RC (1 pc.)
Detector: Differential refractometer (RI)
The molecular weight was determined in terms of polystyrene.

<Preparation of (meth) acrylic polymer>
(Acrylic polymer (A))
A four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser is charged with 95 parts by weight of n-butyl acrylate, 5 parts by weight of acrylic acid, and 150 parts by weight of toluene, and purged with nitrogen at room temperature for 1 hour. Did. Thereafter, the liquid temperature in the flask was raised to 60 ° C., 0.2 part by weight of 2,2′-azobisisobutyronitrile as a polymerization initiator was added, and the liquid temperature in the flask was kept at 63 ° C. Polymerization was performed for 7 hours to prepare an acrylic polymer (A) solution (33% by weight). The acrylic polymer (A) had a weight average molecular weight of 500,000.

(Acrylic polymer (B))
A four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with 95 parts by weight of n-butyl acrylate, 3 parts by weight of acrylic acid, 3 parts by weight of vinyl acetate, and 150 parts by weight of toluene, Nitrogen substitution was performed at room temperature for 1 hour. Thereafter, the liquid temperature in the flask is raised to 60 ° C., 0.2 part by weight of 2,2′-azobisisobutyronitrile as a polymerization initiator is added, and the liquid temperature in the flask is kept at 60 ° C. Polymerization was performed for 6 hours to prepare an acrylic polymer (B) solution (35% by weight). This acrylic polymer (B) had a weight average molecular weight of 500,000.

<Preparation of surfactant solution>
(Surfactant solution (a))
10 parts by weight of n-dodecyltrimethylammonium surfactant (manufactured by Tokyo Chemical Industry Co., Ltd., solid content: 100% by weight, solid at 25 ° C.) is diluted with 90 parts by weight of methyl ethyl ketone and 10 parts by weight of isopropyl alcohol to obtain surface activity. An agent solution (a) (9.1% by weight) was prepared.

<Preparation of tackifying resin solution>
(Tackifying resin solution (a))
60 parts by weight of a rosin-based phenolic resin (Sumitomo Bakelite, melting point: 135 ° C., acid value: 65 mgKOH / g), which is a tackifying resin, is diluted with 40 parts by weight of toluene to give a tackifying resin solution (a) (60 % By weight) was prepared.

[Example 1]
(Preparation of adhesive composition)
The acrylic polymer (A) solution (33% by weight) was diluted to 25% by weight with toluene, and glycidyltrimethylammonium bis (trifluoromethanesulfonyl) imide (manufactured by Nippon Carlit Co., Ltd.) was added as an ionic liquid to 100 parts by weight of this solution. 10 parts by weight of GTA-IL (liquid at 25 ° C.), 0.05 parts by weight of polyhydroxylalkylamine compound (EDP-300 manufactured by Asahi Denka Co., Ltd.) as compound (c), trimethylolpropane / tolylene diisocyanate trimer 5.5 parts by weight of an adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L) was added and mixed and stirred at 25 ° C. for about 1 minute to prepare an acrylic pressure-sensitive adhesive solution (1).

(Preparation of adhesive sheet)
The acrylic pressure-sensitive adhesive solution (1) was applied on a polyethylene terephthalate film (thickness: 50 μm) with a silicone treatment on one side and a polyethylene terephthalate film (thickness: 38 μm) with a silicone treatment on one side, Heating was performed at 110 ° C. for 3 minutes to form two adhesive layers each having a thickness of 40 μm. Next, a polyethylene terephthalate film (thickness: 38 μm) was bonded to the surface of one of the pressure-sensitive adhesive layers, and the surface of the remaining one pressure-sensitive adhesive layer was bonded to the surface to prepare a pressure-sensitive adhesive sheet. After preparing the pressure-sensitive adhesive sheet, a sample left for 7 days in an environment at 23 ° C. was used as an evaluation sample.

[Example 2]
(Preparation of adhesive composition)
An acrylic pressure-sensitive adhesive solution (2) was obtained in the same manner as in Example 1 except that the acrylic polymer (B) solution (35% by weight) was used instead of the acrylic polymer (A) solution (33% by weight). ) 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 (2) was used instead of the acrylic pressure-sensitive adhesive solution (1).

Example 3
(Preparation of adhesive composition)
Further, an acrylic pressure-sensitive adhesive solution (3) was prepared in the same manner as in Example 2 except that 20 parts by weight of the tackifying resin solution (a) was added.

(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).

[Comparative Example 1]
(Preparation of adhesive composition)
An acrylic pressure-sensitive adhesive solution (4) was prepared in the same manner as in Example 1 except that the ionic liquid 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 (4) was used instead of the acrylic pressure-sensitive adhesive solution (1).

[Comparative Example 2]
(Preparation of adhesive composition)
An acrylic pressure-sensitive adhesive solution (5) was prepared in the same manner as in Example 2 except that the ionic liquid was not used.

(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 3]
(Preparation of adhesive composition)
An acrylic pressure-sensitive adhesive solution (6) was prepared in the same manner as in Example 3 except that the ionic liquid 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 (6) was used instead of the acrylic pressure-sensitive adhesive solution (1).

[Comparative Example 4]
(Preparation of adhesive composition)
An acrylic pressure-sensitive adhesive solution (7) was prepared in the same manner as in Example 2 except that 10 parts by weight of the surfactant solution (a) was used instead of 10 parts by weight of 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 (7) was used instead of the acrylic pressure-sensitive adhesive solution (1).

About the adhesive sheet obtained by said Example and comparative example, the peeling band voltage, the retention strength, and adhesive force were evaluated in the following way.

<Measurement of peeling voltage>
The pressure-sensitive adhesive sheet was cut to a size of 70 mm in width and 100 mm in length, and the polyethylene terephthalate (thickness: 38 μm) subjected to silicone treatment was peeled off, and then an acrylic plate (Mitsubishi Rayon Co., Ltd., acrylate, (Thickness: 1 mm, width: 70 mm, length: 100 mm) The surface was pressure-bonded using a hand roller.

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. The end portion of polyethylene terephthalate (thickness: 50 μm) subjected to silicone treatment was fixed to an automatic winder and peeled so that the peeling angle was 150 ° and the peeling speed was 10 m / min. The potential of the acrylic pressure-sensitive adhesive layer 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 to obtain a value of the stripping voltage. The measurement was performed in an environment of 20 ° C. × 25% RH.

The absolute value of the peeling voltage in the antistatic pressure-sensitive adhesive sheet is preferably +0.2 kV or less.

<Measurement of holding power>
Polyethylene terephthalate (thickness: 25 μm) was bonded to one side of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet using a hand roller and cut into a size of 10 mm width × 100 mm. Next, this cut adhesive sheet is pressure-bonded to a bake plate adherend as an adherend (a method in which a 2 kg roller is reciprocated once with a 10 mm width × 20 mm adhesion area) and left at 40 ° C. for 1 hour, A load of 500 g was applied to the end portion, and the size (distance) of the deviation after 1 hour at 40 ° C. was measured according to JIS Z0237 method to determine the holding force.

In addition, the value of the holding force in the antistatic pressure-sensitive adhesive sheets is preferably about 0.1 mm / hr or less, and those that fall in a short time (less than 1 hour) are not preferable.

<Measurement of adhesive strength>
Polyethylene terephthalate (thickness: 25 μm) was bonded to one side of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet using a hand roller, and cut into a size of 20 mm width × 100 mm. Next, this cut adhesive sheet is pressure-bonded to an acrylic plate (Acrylite manufactured by Mitsubishi Rayon Co., Ltd.) as an adherend (a method in which a 2 kg roller is reciprocated once with a 20 mm width × 100 mm adhesive area) at 23 ° C. After leaving for 20 minutes, in accordance with JIS Z0237 method, it was peeled using a tensile tester so that the tensile speed was 300 mm / min and the peeling angle was 180 °, and the adhesive strength was measured. The measurement was performed in an environment of 23 ° C. × 50% RH.

In addition, it is preferable that the value of the adhesive force in an antistatic adhesive sheet is 8 N / 20mm or more.

The results are shown in Table 1.

According to the results of Table 1 above, when the pressure-sensitive adhesive composition prepared according to the present invention was used (Examples 1 to 3), the peeling voltage of the pressure-sensitive adhesive layer was suppressed in all the examples, and excellent retention was achieved. It became clear that force and adhesive strength could be combined.

On the other hand, in the case where no ionic liquid was included (Comparative Examples 1 to 3), in all cases, the stripping voltage was higher than the results of the Examples. Further, when a surfactant was used instead of the ionic liquid (Comparative Example 4), although the peeling band voltage was suppressed, the holding power was poor and the adhesive strength was poor. Accordingly, in all of the comparative examples, it was impossible to suppress the peeling band voltage of the pressure-sensitive adhesive layer and to make the cohesive force (holding force) and the adhesive force juxtaposed at a high level. It became clear that it was not suitable for an agent composition.

Claims (8)

(A) an ionic liquid, (b) a (meth) acrylic polymer containing as a main component at least one (meth) acrylate having an alkyl group having 4 to 12 carbon atoms, and (c) two or more in the molecule A compound containing a hydroxyl group of (referred to as compound (c)),
The compound (c) is an aliphatic polyol, alicyclic polyol, aromatic polyol, polyether polyol, polyester polyol, acrylic polyol, polyurethane polyol, polycaprolactone polyol, polycarbonate polyol, polyhydroxyalkylamine compound, or polyalkylenediamine. Oxyalkylene condensates, dialcohol amines, trialcohol amines,
The pressure-sensitive adhesive composition, wherein the (meth) acrylic polymer has a weight average molecular weight of 300,000 to 1,300,000.   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 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 adhesive composition in any one of Claims 1-3 containing an isocyanate compound. The pressure-sensitive adhesive composition according to any one of claims 1 to 4, wherein the compound (c) is a compound containing a nitrogen atom in the molecule. Furthermore, the adhesive composition in any one of Claims 1-5 containing tackifying resin. The adhesive layer formed by bridge | crosslinking the adhesive composition in any one of Claims 1-6. A pressure-sensitive adhesive sheet obtained by forming a pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition according to claim 1 on one or both sides of a support.

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