Antistatic and adhesive compositions having a bisquaternary onium skeleton

Abstract

This invention provides an antistatic agent that complies with PFAS regulations, exhibiting excellent resin compatibility and exhibiting sufficient antistatic performance with only a small amount of additive. [Solution] An antistatic agent comprising one or more onium salts selected from formulas (1) and (2). TIFF2026058576000010.tif23169 TIFF2026058576000011.tif25168 (In the formula, R1 to R4 are alkyl groups that may be the same or different, X represents an alkyl chain or a heteroatom-containing alkyl chain, and Y is a bisfluorosulfonyliimide or bisoxalatoborate anion.)

Description

Technical Field

[0001] The present invention relates to an antistatic agent using an onium salt composed of a cation having a bisquaternary onium skeleton and a bisfluorosulfonylimide or bisoxalatoborate anion, an adhesive composition containing the same, and an antistatic resin.

Background Art

[0002] As a method for imparting antistatic performance to an insulating resin, a method of coating a conductive coating film containing an antistatic agent on the surface of a resin substrate is known. Examples of the antistatic agent include electronic conductive materials such as carbon black and ITO. However, when used in adhesives or the like using resin, there are problems with the hardness and transparency of the adhesive layer. As an antistatic agent that imparts conductivity while maintaining the transparency of the adhesive layer, an ion conductive material using an onium salt is known.

[0003] Ion conductive materials are ionic compounds of anions and cations, and various applied researches have been conducted based on their properties. By devising the type or addition amount of the ion conductive material added to the insulating resin, conductivity can be imparted to the raw resin, and different antistatic properties according to the purpose can be exhibited in the produced resin material.

[0004] In addition, some onium salts have excellent properties such as non-volatility, flame retardancy, and high ion conductivity, and are attracting attention because their physical properties and functions can be designed in various ways. Due to such properties, onium salts are used as antistatic agents for various resins.

[0005] As described in Patent Document 1 below, it is known to use an ionic liquid having an anion such as bistrifluoromethanesulfonylimide or trifluoromethanesulfonate to impart antistatic performance to adhesives and the like using onium salts. However, perfluoroalkyl compounds and polyfluoroalkyl compounds are not very preferable from the viewpoint of recent PFAS regulations, and an antistatic agent not included in PFAS regulations is desired.

[0006] As antistatic agents not included in PFAS regulations, Patent Document 2 reports on bisfluorosulfonylimide, and Patent Documents 3 and 4 report on onium salts with bisoxalate borate as anions. Pyridinium cations, imidazolium cations, ammonium cations, etc., are used as cations, but these antistatic agents have low antistatic ability, and there were problems with surface resistance characteristics when antistatic agents were added to adhesives.

[0007] Although ionic liquids comprising cations having a bisquaternary onium skeleton, such as bispyridinium or bisimidazolium, have been disclosed as described in Patent Documents 5 and 6 below, they have not been used as antistatic agents in adhesive applications. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2005-290357 [Patent Document 2] Japanese Patent Publication No. 2013-064146 [Patent Document 3] Japanese Patent Publication No. 2019-108414 [Patent Document 4] Japanese Patent Publication No. 2020-007471 [Patent Document 5] International Publication No. 2011 / 024988 [Patent Document 6] Chinese Patent Application Publication No. 110734404 Specification [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention aims to provide an antistatic agent that complies with PFAS regulations, exhibiting excellent resin compatibility and sufficient antistatic performance with only a small amount of addition. Furthermore, it aims to provide an adhesive composition using such an antistatic agent as an adhesive, and an antistatic adhesive resin with excellent surface resistance characteristics. [Means for solving the problem]

[0010] As a result of diligent research, the inventors have discovered that by using an onium salt comprising a cation having a bisquaternary onium skeleton and a bisfluorosulfonylimide anion or bisoxalatoborate anion as an antistatic agent, an antistatic agent with excellent antistatic properties, an adhesive composition using such an antistatic agent as an adhesive, and an antistatic adhesive resin with excellent surface resistance characteristics can be obtained, thus completing the present invention.

[0011] The present invention is as follows [1] to [5].

[0012] [1] An antistatic agent comprising one or more onium salts selected from formulas (1) and (2). [ka] [ka] (In the formula, R1 to R4 are alkyl groups that may be the same or different, X represents an alkyl chain or a heteroatom-containing alkyl chain, and Y is a bisfluorosulfonyliimide or bisoxalatoborate anion.) [2] The antistatic agent according to [1], wherein the onium salt represented by the formula (1) or formula (2) is any one selected from the group consisting of 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium) = bisoxalatoborate, 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium) = bisoxalatoborate, 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium) = bisfluorosulfonylimide, and 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium) = bisfluorosulfonylimide. [3] An antistatic resin characterized by containing the antistatic agent according to [1] or [2] and a resin. [4] An adhesive composition characterized by containing the antistatic agent according to [1] or [2] and an acrylic adhesive. [5] The adhesive composition according to [4], characterized by containing 0.1 to 10 parts by mass of the antistatic agent with respect to 100 parts by mass of the resin component of the acrylic adhesive. [Effect of the Invention]

[0013] The antistatic agent of the present invention can exhibit sufficient antistatic ability with a small amount of addition. Therefore, if the antistatic agent of the present invention is used in an adhesive composition, it is possible to form an antistatic adhesive resin excellent in surface resistance value characteristics, and it can be used for a surface protection film that protects the surface of an optical member or an electronic material member. [Embodiments for Carrying Out the Invention]

[0014] The present invention will be described below. Note that the present invention is not limited to the following embodiments.

[0015] [Onium Salt] The antistatic agent of the present invention consists of one or more onium salts selected from the formula (1) and the formula (2). This onium salt consists of a bisimidazolium-based or bispyridinium-based cation and a bisfluorosulfonylimide or bisoxalatoborate anion.

[0016] [Chemistry] [Chemistry]

[0017] In formula (1) or formula (2), R1 to R4 may be the same or different and are alkyl groups having 1 to 16 carbon atoms. When R1 to R4 are alkyl groups, they may be either straight-chain or branched-chain. Specific alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, cyclopropyl group, butyl group, s-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group.

[0018] X is an alkyl chain or an alkyl chain containing heteroatoms. The alkyl chain represented by X may be either straight-chain or branched-chain and includes alkyl groups having 1 to 20 carbon atoms. Specific alkyl chains include methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, heptadecamethylene group, octadecamethylene group, nonadecamethylene group, icosamethylene group, etc. [[ID=,18]]

[0019] In addition, the alkyl chain containing heteroatoms represented by X includes those usually containing 1 to 5 heteroatoms in the alkylene chain. Specifically, for example, the group represented by formula (3) TIFF2026058576000005.tif21169(In the formula, X2 and X3 each independently represent an alkyl chain having 1 to 10 carbon atoms, T represents an oxygen atom or a sulfur atom, and n represents an integer of 1 to 5.) In formula (3), the alkyl chains having 1 to 10 carbon atoms represented by X2 and X3 specifically include methylene groups, ethylene groups, trimethylene groups, tetramethylene groups, pentamethylene groups, hexamethylene groups, heptamethylene groups, octamethylene groups, nonamethylene groups, decamethylene groups, and the like.

[0020] Y is a bisfluorosulfonylimide or a bisoxalatoborate anion. The combination of R1-R4 and X(X2, X3, T, n) is preferably such that R1-R4 are methyl groups, X2 and X3 are linear groups with 2 carbon atoms, and T is an oxygen atom with n=1. Y may be either a bisfluorosulfonylimide or a bisoxalatoborate anion.

[0021] Specific examples of the bisimidazolium-based cations represented by formula (1) include: 3,3'-(1,3'-propanediyl)bis(1-methylimidazolium) cation, 3,3'-(1,4'-butanediyl)bis(1-methylimidazolium) cation, 3,3'-(1,5'-pentanediyl)bis(1-methylimidazolium) cation, 3,3'-(1,6'-hexanediyl)bis(1-methylimidazolium) cation, and 3,3'-(1,7'-heptanediyl)bis(1-methylimidazolium) Examples include midazolium) cation, 3,3'-(1,8'-octanediyl)bis(1-methylimidazolium) cation, 3,3'-(thiodi-2,1-ethanediyl)bis(1-methylimidazolium) cation, and 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium) cation. Among these bisimidazolium-based cations, 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium) cation is preferred, with 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium) cation being more preferred.

[0022] Specific examples of bispyridinium-based cations represented by formula (2) include: 1,1'-(1,3'-propanediyl)bis(3-methylpyridinium) cation, 1,1'-(1,4'-butanediyl)bis(3-methylpyridinium) cation, 1,1'-(1,5'-pentanediyl)bis(3-methylpyridinium) cation, 1,1'-(1,6'-hexanediyl)bis(3-methylpyridinium) cation, and 1,1'-(1,7'-heptanediyl)bis(3-methyl Examples include pyridinium cations, 1,1'-(1,8'-octanediyl)bis(3-methylpyridinium) cations, 1,1'-(thiodi-2,1-ethanediyl)bis(3-methylpyridinium) cations, and 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium) cations. Among these bispyridinium-based cations, 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium) cations are preferred, and more preferably, 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium) cations.

[0023] In formula (1) or (2), the anion represents bisfluorosulfonylimide or bisoxalatoborate.

[0024] The antistatic agent of the present invention preferably uses one selected from the group consisting of 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium)=bisoxalatoborate, 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium)=bisoxalatoborate, 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium)=bisfluorosulfonylimide, and 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium)=bisfluorosulfonylimide, among the onium salts represented by formula (1) or (2).

[0025] The onium salt represented by formula (1) or formula (2) above can be produced using known methods to obtain the above structure. Examples of such methods include the following. The compound used in this reaction can be a commercially available product or one synthesized by known methods. [Method for producing onium salt] TIFF2026058576000006.tif88169

[0026] In the glycols represented by formula (4) above, X can be selected from the group consisting of alkyl chains or heteroatom-containing alkyl chains. The alkyl chain represented by X may be linear or branched, and examples include alkyl groups having 1 to 20 carbon atoms. The heteroatom-containing alkyl chain represented by X is the same as in formula (3) above. Specific examples include 2,2'-oxydiethanol (diethylene glycol).

[0027] By subjecting glycols represented by formula (4) to an intramolecular nucleophilic substitution reaction with thionyl chloride represented by formula (5), chlorides represented by formula (6) are obtained.

[0028] The solvent for the intramolecular nucleophilic reaction of formula (4) by formula (5) is not particularly limited as long as it does not affect the reaction. Specifically, examples include water, dichloromethane, tetrahydrofuran, methanol, ethanol, dimethylformamide, toluene, acetonitrile, etc., with methanol and acetonitrile being preferred.

[0029] The amount of formula (5) used should be 0.9 moles or more per mole of formula (4), preferably 1.1 to 1.6 moles.

[0030] The reaction temperature in intramolecular nucleophilic reactions is usually 20°C or higher, preferably 25-60°C, and particularly preferably 25-50°C.

[0031] In the imidazoles of formula (7), R is an alkyl group having 1 to 16 carbon atoms, which may be linear or branched, and examples include 1-methylimidazole.

[0032] By quaternizing the imidazoles represented by formula (7) with thionyl chloride represented by formula (6), bisimidazolium chloride represented by formula (8) is obtained. Subsequently, a double decomposition reaction of the lithium salts of formula (8) and formula (9) yields the bisimidazolium salt represented by formula (1).

[0033] In the pyridinium compounds of formula (10), R is an alkyl group having 1 to 16 carbon atoms, which may be either linear or branched, and examples include 3-methylpyridinium.

[0034] By quaternizing the pyridinium compounds represented by formula (10) with thionyl chloride represented by formula (6), bispyridinium chloride represented by formula (11) is obtained. Subsequently, a double decomposition reaction of the lithium salts of formula (11) and formula (9) yields the bispyridinium salt represented by formula (2).

[0035] The quaternization reaction of formula (7) or formula (10) using formula (6) may or may not be carried out with a solvent. The solvent is not particularly limited as long as it does not affect the reaction. Specifically, examples include acetonitrile, methanol, ethyl acetate, benzene, toluene, xylene, diethyl ether, tetrahydrofuran, 1,4-dioxane, etc., with acetonitrile and toluene being preferred.

[0036] The amount of formula (6) used should be 0.3 moles or more per mole of formula (7) or formula (10), preferably 0.3 to 0.6 moles.

[0037] The reaction temperature in the quaternization reaction is usually 25°C or higher, preferably 30-150°C, and particularly preferably 60-120°C.

[0038] Examples of lithium salts in formula (9) include lithium bisoxalatoborate and lithium bisfluorosulfonylimide metal salts. In other words, Y is either bisfluorosulfonylimide or bisoxalatoborate.

[0039] The amount of formula (9) used in the double decomposition reaction is usually 1.8 moles or more, preferably 1.9 to 2.8 moles, and more preferably 2.0 to 2.2 moles, per mole of formula (8) or formula (11).

[0040] The double decomposition reaction is usually carried out in a solvent. The solvent is not particularly limited as long as it does not affect the reaction. Specifically, examples include pure water, acetonitrile, ethyl acetate, benzene, toluene, xylene, diethyl ether, tetrahydrofuran, 1,4-dioxane, etc., with pure water and acetonitrile being preferred.

[0041] The mixing order of formula (8) or formula (11), formula (9), and the solvent is not particularly limited. Formula (9) may be added after mixing formula (8) or formula (11) with the solvent, or formula (8) or formula (11) may be added after mixing formula (9) with the solvent.

[0042] The reaction temperature in the double decomposition reaction is usually 10°C or higher, preferably 10 to 60°C, and particularly preferably 15 to 50°C.

[0043] To isolate formula (1) or formula (2) from the reaction solution after the reaction is complete, the solvent and the resulting inorganic salt are removed from the reaction solution. If inorganic salts precipitate in the resulting reaction solution, the solution is filtered to remove the precipitated inorganic salts, and then formula (1) or formula (2) is isolated by combining appropriate unit operations such as concentration, filtration, and extraction. Formulas (1) and (2) obtained by isolation can be used as antistatic agents.

[0044] The antistatic agent obtained in this way does not contain compounds included in PFAS regulations, such as perfluoroalkyl compounds and polyfluoroalkyl compounds, and is therefore an antistatic agent that does not fall under PFAS regulations. Furthermore, the antistatic agent of the present invention, which is obtained by combining a bisimidazolium-based or bispyridinium-based cation with a bisfluorosulfonylimide or bisoxalatoborate anion, exhibits particularly excellent conductivity and good antistatic performance compared to when other onium salts are selected.

[0045] Furthermore, compared to dimer cations, trimer cations and polymer cations are difficult to apply as antistatic agents to adhesives. Trimer cations are difficult to synthesize due to high steric hindrance, and their trication derivatives have poor stability. Polymer cations do not exhibit cationic conductivity, so achieving sufficient antistatic properties is limited to those containing halogens in the anion, thus limiting their applications.

[0046] [Adhesive composition and antistatic adhesive resin] By combining the antistatic agent of the present invention with an acrylic adhesive, an adhesive composition with antistatic properties can be obtained. This antistatic adhesive composition, when incorporated into a resin, becomes an antistatic adhesive resin. This antistatic adhesive resin exhibits excellent antistatic properties. Specifically, the surface resistance of the antistatic adhesive resin formed from the adhesive composition is 1.0 × 10⁻⁶. 9 The surface resistance value is less than Ω. The surface resistance value is measured using a resistivity meter. Therefore, the adhesive composition of the present invention contains at least the above-mentioned bisimidazolium salt or bispyridinium salt and an acrylic adhesive. The adhesive ink prepared by dissolving the above-mentioned adhesive composition in a soluble organic solvent is included in the adhesive composition of the present invention. Furthermore, the antistatic adhesive resin of the present invention also includes adhesive sheets, adhesive films formed by coating the above-mentioned adhesive ink onto a substrate, and those peeled off from the substrate. Furthermore, the antistatic adhesive resin of the present invention is usually used as what is called an adhesive layer.

[0047] The acrylic adhesive in the present invention preferably contains an acrylic polymer mainly composed of an acrylate or methacrylate having an alkyl group with 1 to 14 carbon atoms. Specifically, examples include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl acrylate, and the like.

[0048] The mass-average molecular weight of the acrylic polymer is 100,000 to 5,000,000, preferably 200,000 to 4,000,000, and more preferably 300,000 to 3,000,000. If the mass-average molecular weight is less than 100,000, there is a problem that the cohesive force of the adhesive composition will be weak, and when an adhesive sheet is made by forming an adhesive layer on a substrate as an antistatic adhesive resin, there is a risk that the adhesive will peel off from the substrate when peeling the adhesive layer from the adherend. On the other hand, if it exceeds 5,000,000, the fluidity of the polymer may decrease, which may reduce the adhesive force to the adherend. The mass-average molecular weight can be measured by gel permeation chromatography (GPC).

[0049] Acrylic polymers can be obtained by common polymerization methods for acrylic polymers, such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization, and may be random copolymers, block copolymers, graft copolymers, etc.

[0050] Furthermore, by appropriately crosslinking the acrylic polymer, an adhesive composition with a heat-resistant adhesive layer can be obtained. One method of crosslinking is to add a crosslinking agent to the acrylic adhesive. Examples of crosslinking agents include isocyanate compounds, epoxy compounds, aziridine compounds, and metal chelate compounds.

[0051] Isocyanate compounds are compounds having at least two isocyanate groups (-NCO) in their molecule. Specifically, examples include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate; aromatic diisocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate; and isocyanate adducts such as trimethylolpropane / tolylene diisocyanate trimer adducts, trimethylolpropane / hexamethylene diisocyanate trimer adducts, and isocyanurates of hexamethylene diisocyanate.

[0052] Epoxy compounds are compounds that have at least two epoxy groups in their molecule. Specifically, examples include bisphenol A type epoxy resins, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, 1,6-hexanediol diglycidyl ether, and N,N-diglycidylaniline.

[0053] Aziridine compounds are compounds that have at least two three-membered ring skeletons, also known as ethyleneimines, consisting of one nitrogen atom and two carbon atoms, within their molecule. Specifically, examples include diphenylmethane-4,4'-bis(1-aziridinecarboxamide), toluene-2,4-bis(1-aziridinecarboxamide), triethylenemelamine, isophthaloylbis-1-(2-methylaziridine), tris-1-aziridinylphosphine oxide, hexamethylene-1,6-bis(1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, and tetramethylolmethane-tri-β-aziridinylpropionate.

[0054] Examples of metal chelate compounds include compounds in which acetylacetone or ethyl acetoethyl is coordinated to polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium.

[0055] The crosslinking agent content is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5.0 parts by mass, per 100 parts by mass of the acrylic adhesive. If the content is less than 0.01 parts by mass, the crosslinking will be insufficient, resulting in a weak cohesive force of the adhesive composition and insufficient heat resistance. On the other hand, if the content exceeds 10 parts by mass, the polymer cohesive force will be too strong, reducing fluidity and resulting in insufficient wettability to the adherend, which can cause peeling.

[0056] The adhesive composition of the present invention may contain a surfactant comprising an alkylene oxide group-containing compound. An alkylene oxide group-containing compound is a compound having an alkylene oxide group, and specifically includes alkylene oxide group-containing surfactants, alkylene oxide group-containing polyether polymers, and alkylene glycol group-containing (meth)acrylic polymers. Among these, alkylene oxide group-containing surfactants are preferably used because they have good compatibility with acrylic polymers.

[0057] Examples of alkylene oxide group-containing surfactants include nonionic surfactants such as polyoxyalkylene fatty acid esters, polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene sorbitol fatty acid esters, polyoxyalkylene alkyl ethers, polyoxyalkylene alkylallyl ethers, polyoxyalkylene alkylphenyl ethers, polyoxyalkylene derivatives, polyoxyalkylene alkylamines, and polyoxyalkylene alkylamine fatty acid esters; anionic surfactants such as polyoxyalkylene alkyl ether sulfates, polyoxyalkylene alkyl ether phosphates, polyoxyalkylene alkylphenyl ether sulfates, and polyoxyalkylene alkylphenyl ether phosphates; cationic surfactants and zwionic surfactants having alkylene oxide groups. Furthermore, the molecule may contain reactive substituents such as (meth)acryloyl groups and allyl groups.

[0058] The alkylene oxide group-containing compound may be used alone or as a mixture of two or more types. The amount added is preferably 0.01 to 10 parts by mass, and more preferably 0.05 to 5 parts by mass, per 100 parts by mass of the acrylic polymer. If the amount is less than 0.01 parts by mass, bleeding may occur.

[0059] Furthermore, the adhesive composition of the present invention may contain a silane compound. By including a silane compound, adhesion to substrates such as films and glass can be improved.

[0060] Examples of silane compounds include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, and 3-glycidoxypropylethoxydimethylsilane. Two or more of these may be used in combination.

[0061] The amount of bisimidazolium salt or bispyridinium salt represented by formula (1) or formula (2) in the adhesive composition of the present invention is preferably 0.01 to 20 parts by mass, and more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the acrylic adhesive. By adjusting the amount within this range, an adhesive composition with even better electrical properties can be obtained. Furthermore, the adhesive composition of the present invention is not subject to PFAS regulations.

[0062] The adhesive composition of the present invention may be used in combination with other binder resins, antioxidants, ultraviolet absorbers, lubricants, etc., as long as the effects of the present invention are not impaired.

[0063] When producing an adhesive sheet with an adhesive layer formed on a substrate using an antistatic adhesive resin, the adhesive composition of the present invention may be applied directly to the substrate, or an adhesive ink prepared by dissolving the adhesive composition in a soluble organic solvent may be applied to the substrate. By applying these adhesive compositions or adhesive inks to substrates such as resin films and glass, and then drying them as necessary, an adhesive sheet with an adhesive layer formed on the surface of these substrates can be produced. The thickness of the adhesive layer is preferably 3 to 100 μm, and more preferably 5 to 50 μm.

[0064] [Adhesive ink] Organic solvents used in adhesive inks as adhesive compositions include alcohol-based solvents such as methanol, ethanol, propanol, isopropanol (IPA), and butanol; glycol-based solvents such as ethylene glycol, propylene glycol, butylene glycol, polyethylene glycol, polypropylene glycol, and polyoxyethylene polyoxypropylene copolymer; ether alcohol-based solvents such as monomethyl ether, monoethyl ether, monopropyl ether, monoisopropyl ether, and monobutyl ether of the glycol-based solvents; polyether-based solvents such as dimethyl ether, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, methyl ethyl ether, methyl propyl ether, methyl isopropyl ether, methyl butyl ether, ethyl propyl ether, ethyl isopropyl ether, and ethyl butyl ether of the glycol-based solvents; ketone-based solvents such as methyl ethyl ketone (MEK), methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as methyl acetate, ethyl acetate, and butyl acetate; and hydrocarbon-based solvents such as hexane, heptane, octane, cyclopentane, cyclohexane, toluene, and xylene. Among these, toluene, MEK, ethyl acetate, butyl acetate, and IPA are particularly preferred.

[0065] [Base material] Examples of substrates include polyethylene terephthalate (PET) film, polycarbonate film, polystyrene film, acrylic film, cellulose triacetate film, polyethylene film, and polypropylene film.

[0066] [Method for making adhesive sheets] Methods for applying adhesive compositions to substrates include roll coating, gravure coating, reverse coating, die coating, and comma coating. When drying to remove the solvent from the liquid film applied to the substrate, it is preferable that the drying temperature be between 50°C and 150°C from the viewpoint of promoting the hardening of the liquid film.

[0067] To protect the adhesive surface, a separator can be attached to the surface of the adhesive layer as needed. Paper or plastic film can be used as the separator, and plastic film is preferred due to its excellent surface smoothness.

[0068] Examples of plastic films include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, polyethylene terephthalate film, polybutylene terephthalate film, and polyurethane film.

[0069] The adhesive composition of the present invention and the adhesive sheets (antistatic adhesive resin) produced using it can be used in plastic products and the like. In particular, they can be used as surface protection films to protect the surfaces of optical components such as polarizing plates, wave plates, optical compensation films, light diffusion sheets, and reflective sheets used in liquid crystal displays, as well as protective films for electronic materials and semiconductor components.

[0070] [Antistatic resin] As described above, the antistatic agent of the present invention, when combined with an acrylic adhesive, can yield an adhesive composition with antistatic properties. Naturally, by simply incorporating it into various resins, the resin can be made conductive and thus an antistatic resin. Examples of resins that can contain the antistatic agent of the present invention include, in addition to acrylic adhesives, synthetic resins such as polyethylene terephthalate, polypropylene, and polycarbonate, as well as various adhesives or release agents (silicone adhesives, urethane adhesives, rubber adhesives, silicone release agents, fluorine release agents, acrylic release agents, etc.). The performance of the antistatic resin of the present invention is the same as that of the adhesive layer (antistatic adhesive resin) described above. Furthermore, it is preferable that the resin does not fall under PFAS regulations and does not contain halogens.

[0071] The antistatic resin of the present invention can be manufactured in the same manner as conventional antistatic resins using known antistatic agents. If the resin is, for example, an acrylic adhesive, a synthetic resin such as polyethylene terephthalate, polypropylene, or polycarbonate, or various adhesives or release agents (silicone adhesives, urethane adhesives, rubber adhesives, silicone release agents, fluorine release agents, acrylic release agents, etc.), an antistatic resin can be obtained by mixing them. Furthermore, if an acrylic resin monomer is used as the raw material for the resin, the antistatic resin of the present invention can be obtained by preparing a solution containing the acrylic resin monomer and the antistatic agent of the present invention, adding a photopolymerization initiator to the solution, and irradiating the resin coated with this solution with ultraviolet light. [Examples]

[0072] The present invention will be described in detail below with reference to examples of the present invention, but the present invention is not limited in any way to these examples.

[0073] (Example 1) [Preparation of adhesive ink] • Acrylic adhesive (manufactured by Soken Chemical Co., Ltd., 2030U, non-volatile content 15%): 40g • Hardening agent (isocyanate compound, manufactured by Soken Chemical Co., Ltd., Y-75, non-volatile content 75%): 0.32g • Antistatic agent (3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium)=bisfluorosulfonylimide): 0.12g The above composition was diluted with MEK to a non-volatile content concentration of 15 parts by mass to prepare an adhesive ink.

[0074] [Manufacturing of antistatic agents] 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium)=bisfluorosulfonylimide was prepared as follows.

[0075] 29.6 g of 1-methylimidazole was mixed with 25.7 g of bis(2-chloroethyl) ether (manufactured by Tokyo Chemical Industry Co., Ltd.) and 10 g of toluene. The mixture was heated and stirred at 120°C for 10 hours. The solvent was removed by concentration to obtain 56.7 g of 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium) chloride. 80 g of pure water was added to the 56.7 g of synthesized 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium) chloride to dissolve it, and then 69.5 g of lithium bisfluorosulfonylimide was added and stirred for 5 hours. The solvent was removed by concentration, and after liquid-liquid washing with dichloromethane and pure water, the mixture was concentrated again to obtain 94.0 g of 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium)bisfluorosulfonylimide (yield 85%). This was used as an antistatic agent.

[0076] (Example 2) An adhesive ink was prepared without any changes except that 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium)=bisoxalatoborate was used instead of the antistatic agent in Example 1.

[0077] [Manufacturing of antistatic agents] 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium)=bisoxalatoborate was prepared as follows.

[0078] 29.6 g of 1-methylimidazole was mixed with 25.7 g of bis(2-chloroethyl) ether (manufactured by Tokyo Chemical Industry Co., Ltd.) and 10 g of toluene. The mixture was heated and stirred at 120°C for 10 hours. The solvent was removed by concentration to obtain 56.7 g of 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium) chloride. 80 g of pure water was added to the 56.7 g of synthesized 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium) chloride and dissolved. Then, 71.7 g of lithium bisoxalatoborate was added and the mixture was stirred for 5 hours. The solvent was removed by concentration, and after liquid-liquid washing with dichloromethane and pure water, the mixture was concentrated again to obtain 87.8 g of 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium)bisoxalatoborate (yield 80%). This was used as an antistatic agent.

[0079] (Example 3) An adhesive ink was prepared without any changes except that 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium)=bisfluorosulfonylimide was used instead of the antistatic agent in Example 1.

[0080] [Manufacturing of antistatic agents] 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium)=bisfluorosulfonylimide was prepared as follows.

[0081] 24.9 g of 3-methylpyridine was mixed with 17.4 g of bis(2-chloroethyl) ether (manufactured by Tokyo Chemical Industry Co., Ltd.) and 5 g of acetonitrile. The mixture was heated and stirred at 85°C for 11 hours. The solvent was removed by concentration to obtain 20.3 g of 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium) chloride. 100 g of pure water was added to the 20.3 g of synthesized 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium) chloride and dissolved. Then, 22.7 g of lithium bisfluorosulfonylimide was added and the mixture was stirred for 5 hours. The solvent was removed by concentration, and after liquid-liquid washing with dichloromethane and pure water, the mixture was concentrated again to obtain 25.1 g of 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium)bisfluorosulfonylimide (yield 68%). This was used directly as an antistatic agent.

[0082] (Example 4) An adhesive ink was prepared without any changes except that 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium)=bisoxalatoborate was used instead of the antistatic agent in Example 1.

[0083] [Manufacturing of antistatic agents] 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium)=bisoxalatoborate was prepared as follows.

[0084] 24.9 g of 3-methylpyridine was mixed with 17.4 g of bis(2-chloroethyl) ether (manufactured by Tokyo Chemical Industry Co., Ltd.) and 5 g of acetonitrile. The mixture was heated and stirred at 85°C for 11 hours. The solvent was removed by concentration to obtain 20.3 g of 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium) chloride. 100 g of pure water was added to the 20.3 g of synthesized 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium) chloride and dissolved. Then, 24.4 g of lithium bisoxalatoborate was added and the mixture was stirred for 5 hours. The solvent was removed by concentration, and after liquid-liquid washing with dichloromethane and pure water, the mixture was concentrated again to obtain 26.5 g of 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium)bisoxalatoborate (yield 70%). This was used directly as an antistatic agent.

[0085] (Comparative Example 1) An adhesive ink was prepared without any changes except that 1-ethyl-3-methylimidazolium=bisfluorosulfonylimide (manufactured by Kishida Chemical Co., Ltd.) was used instead of the antistatic agent in Example 1.

[0086] (Comparative Example 2) An adhesive ink was prepared without any changes except that 1-butyl-3-methylpyridinium-bisfluorosulfonylimide was used instead of the antistatic agent in Example 1. [Manufacturing of antistatic agents] 1-Butyl-3-methylpyridinium-bisfluorosulfonylimide was prepared as follows.

[0087] 105.6 g of 1-butyl-3-methylpyridinium bromide was dissolved in 100 g of pure water, then 101.6 g of potassium bisfluorosulfonylimide was added and the mixture was stirred for 2 hours. The solvent was removed by concentration, and after liquid-liquid washing with dichloromethane and pure water, the mixture was concentrated again to obtain 141.6 g of 1-butyl-3-methylpyridinium bisfluorosulfonylimide (yield 94%). This was used directly as an antistatic agent.

[0088] (Comparative Example 3) An adhesive ink was prepared without any changes except that 1-methyl-3-hexylimidazolium=bisoxalatoborate was used instead of the antistatic agent in Example 1.

[0089] [Manufacturing of antistatic agents] 1-Methyl-3-hexylimidazolium=bisoxalatoborate was prepared as follows:

[0090] 8.21 g of 1-methylimidazole was mixed with 17.33 g of hexyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 85°C for 5 hours. After removing the solvent by concentration, liquid-liquid separation was carried out by adding pure water and hexane to remove unreacted hexyl bromide, and then the mixture was concentrated to obtain 24.47 g of 1-methyl-3-hexylimidazolium bromide (99% yield). 100 g of acetonitrile was added to the 24.47 g of synthesized 1-methyl-3-hexylimidazolium bromide and dissolved, then 21.10 g of lithium bisoxalatoborate was added and the mixture was stirred for 2 hours. After removing the solvent by concentration and washing with dichloromethane and pure water, the mixture was concentrated again to obtain 28.05 g of 1-methyl-3-hexylimidazolium bisoxalatoborate (80% yield). This was used directly as an antistatic agent.

[0091] (Comparative Example 4) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=bisoxalatoborate was used instead of the antistatic agent in Example 1.

[0092] [Manufacturing of antistatic agents] 1-Methyl-3-octylimidazolium=bisoxalatoborate was prepared as follows:

[0093] 8.21 g of 1-methylimidazole was mixed with 20.28 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 85°C for 5 hours. After removing the solvent by concentration, liquid-liquid extraction was carried out by adding pure water and hexane to remove unreacted octyl bromide, and then the mixture was concentrated to obtain 27.25 g of 1-methyl-3-octylimidazolium bromide (99% yield). 100 g of acetonitrile was added to the 27.25 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 21.10 g of lithium bisoxalatoborate was added and the mixture was stirred for 2 hours. After removing the solvent by concentration and washing with dichloromethane and pure water, the mixture was concentrated again to obtain 32.17 g of 1-methyl-3-octylimidazolium bisoxalatoborate (85% yield). This was used directly as an antistatic agent.

[0094] (Comparative Example 5) An adhesive ink was prepared without any changes except that 1-butyl-3-methylpyridinium=bisoxalatoborate was used instead of the antistatic agent in Example 1.

[0095] [Manufacturing of antistatic agents] 1-Butyl-3-methylpyridinium-bisfluorosulfonylimide was prepared as follows.

[0096] 11.5 g of 1-butyl-3-methylpyridinium bromide was dissolved in 15 g of acetonitrile, then 10.2 g of lithium bisoxalatoborate was added and the mixture was stirred for 2 hours. The solvent was removed by concentration, and after liquid-liquid washing with dichloromethane and pure water, the mixture was concentrated again to obtain 14.6 g of 1-butyl-3-methylpyridinium bisoxalatoborate (yield 87%). This was used directly as an antistatic agent.

[0097] (Comparative Example 6) An adhesive ink was prepared without any changes except that N,N'-(oxydi-2,1-ethanediyl)bis(tributylammonium)=bisfluorosulfonylimide was used instead of the antistatic agent in Example 1.

[0098] [Manufacturing of antistatic agents] N,N'-(oxydi-2,1-ethanediyl)bis(tributylammonium)=bisfluorosulfonylimide was prepared as follows.

[0099] 66.7 g of tributylamine was mixed with 25.7 g of bis(2-chloroethyl) ether (manufactured by Tokyo Chemical Industry Co., Ltd.) and 10 g of toluene. The mixture was heated and stirred at 120°C for 10 hours. The solvent was removed by concentration to obtain 53.2 g of N,N'-(oxydi-2,1-ethanediyl)bis(tributylammonium) chloride. 80 g of pure water was added to the 53.2 g of synthesized N,N'-(oxydi-2,1-ethanediyl)bis(tributylammonium) chloride and dissolved. Then, 70.7 g of lithium bisfluorosulfonylimide was added and the mixture was stirred for 5 hours. The solvent was removed by concentration, and after liquid-liquid washing with dichloromethane and pure water, the mixture was concentrated again to obtain 94.5 g of N,N'-(oxydi-2,1-ethanediyl)bis(tributylammonium)bisfluorosulfonylimide (yield 85%). This was used directly as an antistatic agent.

[0100] (Comparative Example 7) An adhesive ink was prepared without any changes except that N,N'-(oxydi-2,1-ethanediyl)bis(tributylammonium)=bisoxalatoborate was used instead of the antistatic agent in Example 1.

[0101] [Manufacturing of antistatic agents] N,N'-(oxydi-2,1-ethanediyl)bis(tributylammonium)=bisoxalatoborate was prepared as follows.

[0102] 66.7 g of tributylamine was mixed with 25.7 g of bis(2-chloroethyl) ether (manufactured by Tokyo Chemical Industry Co., Ltd.) and 10 g of toluene. The mixture was heated and stirred at 120°C for 10 hours. The solvent was removed by concentration to obtain 53.2 g of N,N'-(oxydi-2,1-ethanediyl)bis(tributylammonium) chloride. 80 g of pure water was added to the 53.2 g of synthesized N,N'-(oxydi-2,1-ethanediyl)bis(tributylammonium) chloride and dissolved. Then, 73.3 g of lithium bisoxalatoborate was added and the mixture was stirred for 5 hours. The solvent was removed by concentration, and after liquid-liquid washing with dichloromethane and pure water, the mixture was concentrated again to obtain 92.0 g of N,N'-(oxydi-2,1-ethanediyl)bis(tributylammonium)bisoxalatoborate (yield 81%). This was used directly as an antistatic agent.

[0103] (Test Example 1) [Coating conditions] The adhesive inks produced in Examples 1-4 and Comparative Examples 1-7 were coated onto PET film using a bar coater to a thickness of approximately 25 μm after drying, and then dried in a hot air dryer at 120°C for 3 minutes to prepare test pieces (adhesive films).

[0104] [Surface resistance measurement] Using the HighLester UP (manufactured by Mitsubishi Chemical Analytech Co., Ltd., product name "MCP-HT450"), the probe was pressed against the coated surface of the test specimen at a temperature of 23±2℃, humidity of 50±5%RH, and applied voltage of 100V, and the stable surface resistance value was measured after 30 seconds.

[0105] The results for Examples 1-4 and Comparative Examples 1-7 are shown in Table 1.

[0106] [Table 1]

[0107] As described above, the adhesive inks (adhesive compositions) of Examples 1 to 4 exhibit excellent surface resistance values ​​(1.0 × 10) as antistatic adhesive films (antistatic adhesive resins) even when added in small amounts of 2% or less relative to the resin solid content. 9 It had a resistance of less than Ω. On the other hand, the surface resistance values ​​of Comparative Examples 1-7 were half an order of magnitude to one order of magnitude higher than those of Examples 1-4, despite having similar anionic structures. Furthermore, the adhesive inks of Examples 1-4 are not included in the PFAS regulations. [Industrial applicability]

[0108] This invention can be used in surface protection films and the like to protect the surface of optical components.

Claims

1. An antistatic agent comprising one or more onium salts selected from formulas (1) and (2). 【Chemistry 1】 【Chemistry 2】 (In the formula, R １ ~R ４ (wherein X is an alkyl group that may be the same or different, and X represents an alkyl chain or a heteroatom-containing alkyl chain; Y is a bisfluorosulfonyliimide or bisoxalatoborate anion.)

2. The antistatic agent according to claim 1, wherein the onium salt represented by formula (1) or formula (2) is one selected from the group consisting of 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium)=bisoxalatoborate, 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium)=bisoxalatoborate, 1,1'-(oxydi-2,1-ethanediyl)bis(3-methylpyridinium)=bisfluorosulfonyliimide, and 3,3'-(oxydi-2,1-ethanediyl)bis(1-methylimidazolium)=bisfluorosulfonyliimide.

3. An antistatic resin characterized by containing the antistatic agent and resin described in claim 1 or 2.

4. An adhesive composition characterized by containing the antistatic agent and acrylic adhesive described in claim 1 or 2.

5. The adhesive composition according to claim 4, characterized in that it contains 0.1 to 10 parts by mass of an antistatic agent per 100 parts by mass of the resin component of the acrylic adhesive.

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