Antistatic agent and adhesive agent composition

Abstract

Provided is an antistatic agent comprising a salt represented by formula (1). Also provided is an antistatic resin or an adhesive agent composition containing said antistatic agent. The antistatic resin or the adhesive agent composition has improved moist heat resistance and excellent antistatic performance as compared with existing halogen-free ionic conductive materials. (In formula (1), Q+ represents a cation not including a halogen atom, and R1s each represent a hydrocarbon group having 1-6 carbon atoms, a hydrogen atom, a nitro group, an amino group, a cyano group, a carbonyl group, a hydroxy group, or an alkoxy group, and may be identical or different from each other. Regarding R1s, adjacent groups thereof may be linked to each other to form an alkylene group having 2-6 carbon atoms.)

Description

Antistatic agent and adhesive composition

[0001] The present invention relates to an antistatic agent using a salt comprising a cation that does not contain halogen atoms and an anion having a specific sulfonylimide skeleton, as well as an adhesive composition and an antistatic resin containing the same.

[0002] One known method for imparting antistatic properties to insulating resins is to coat the surface of the resin substrate with a conductive coating containing an antistatic agent. Examples of such antistatic agents include electronically conductive materials such as carbon black and ITO, but when used in adhesives using resins, 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, ionic conductive materials using onium salts are known.

[0003] Other antistatic agents used in resins include solid conductive materials such as metal salts. (Patent Document 1)

[0004] Onium salts are attracting attention because they possess excellent properties such as non-volatility, flame retardancy, and high ionic conductivity, and their physical properties and functions can be designed in various ways. Due to these properties, onium salts are used as antistatic agents for various resins.

[0005] While onium salts are commonly used to impart antistatic properties to adhesives and other materials, such as bis(trifluoromethanesulfonyl)imide (TFSI) and bis(fluorosulfonyl)imide (FSI), which have a fluorine-containing sulfonyliide skeleton, TFSI is not considered desirable from the perspective of recent PFAS regulations, and there is a demand for antistatic agents that are not included in PFAS regulations. Although FSI is a compound not included in PFAS regulations, halogen compounds containing fluorine have adverse effects on the environment, so attention is being paid to halogen-free antistatic agents that do not contain halogens in their molecular structure. (Patent Documents 2 and 3)

[0006] As halogen-free antistatic agents, for example, there are reports of antistatic agents for adhesives that dodecylbenzenesulfonic acid anion is used, but their antistatic performance is low, limiting their range of applications. (Patent Document 4) In addition, there are reports of antistatic agents for adhesives that use bisoxalate borate anion, which is composed of a boron complex anion, but their susceptibility to hydrolysis and poor heat and humidity resistance limit their range of applications. (Patent Documents 5, 6)

[0007] Furthermore, examples of halogen-free onium salts include salts having an anion with a halogen-free sulfonylimide skeleton. These are described in Patent Documents 7, 8, 9, 10 and Non-Patent Document 1 below.

[0008] Japanese Patent Publication No. 6-128539, Japanese Patent Publication No. 2005-290357, Japanese Patent Publication No. 2013-064146, Japanese Patent Publication No. 2023-034983, Japanese Patent Publication No. 2019-108414, Japanese Patent Publication No. 2020-007471, International Publication No. 2018 / 159640, Japanese Patent Publication No. 2003-300953, Japanese Patent Publication No. 2003-532619, Japanese Patent Publication No. 09-235691

[0009] Jenny Pringle. et al. New J. Chem., 2003 Vol.27, P.1504-1510

[0010] Compounds containing perfluoroalkyl groups have a significant environmental impact, leading to increasing regulations. Furthermore, the increasing sophistication of electronic components demands ionic conductive materials with higher antistatic performance. However, TFSI and FSI anions tend to have poor compatibility with resins and thus poor antistatic performance. Therefore, there is a need for high-performance ionic conductive materials that are halogen-free. Examples of halogen-free anions include dodecylbenzenesulfonate anions (DBS) and bisoxalate borate anions (BOB) composed of boron complex anions. However, the former tends to have poor compatibility with resins and poor antistatic performance, while the latter is susceptible to hydrolysis and has poor moisture and heat resistance. The present invention aims to provide an adhesive composition and an antistatic resin that have improved moisture and heat resistance and excellent antistatic performance compared to existing halogen-free ionic conductive materials.

[0011] As a result of diligent research, the inventors have discovered that by using a salt consisting of an anion having a specific sulfonylimide skeleton and a cation that does not contain halogen atoms as an antistatic agent, an antistatic agent with excellent resin compatibility, antistatic performance, and moisture and heat resistance, as well as an adhesive composition with excellent transparency and low haze, and an antistatic resin can be obtained, thus completing the present invention.

[0012] The present invention is as shown in [1] to [5] below.

[0013] [1] An antistatic agent comprising a salt represented by formula (1). (In formula (1), Q ＋ R is a cation that does not contain a halogen atom, １ R represents one of the following: a hydrocarbon group having 1 to 6 carbon atoms, a hydrogen atom, a nitro group, an amino group, a cyano group, a carbonyl group, a hydroxyl group, or an alkoxy group, and these may be the same or different. １ (The adjacent groups may be linked together to form an alkylene group having 2 to 6 carbon atoms.) [2] The above Q + The antistatic agent described in [1], wherein is one of the cations of formulas (2) to (4). (In formula (2), R ２each represents hydrogen, a linear or branched saturated hydrocarbon group having 1 to 12 carbon atoms, an unsaturated hydrocarbon group, an alkoxy group or a hydroxyl group, which may be the same or different, and adjacent groups may be linked to each other to form an alkylene group having 2 to 6 carbon atoms. In formulas (3) and (4), R ３ , R ４ each represents hydrogen, a linear or branched alkyl group having 1 to 12 carbon atoms, an alkoxy group or a hydroxyl group, which may be the same or different. ) [3] An antistatic resin comprising the antistatic agent according to [1] to [2] and a resin. [4] A pressure-sensitive adhesive composition comprising the antistatic agent according to [1] to [2] and an acrylic pressure-sensitive adhesive. [5] The pressure-sensitive adhesive composition according to [4], which comprises 0.1 to 100 parts by mass of the antistatic agent relative to 100 parts by mass of the resin component of the acrylic pressure-sensitive adhesive.

[0014] The antistatic agent of the present invention, as a halogen-free ionic conductive material, has high resin compatibility, is stable even in a high humidity and heat environment, and can exhibit sufficient antistatic performance when added in a small amount. When the antistatic agent of the present invention is used in a pressure-sensitive adhesive composition, it becomes possible to form a pressure-sensitive adhesive layer having high humidity and heat resistance, excellent transparency and low haze, and can be used for a surface protection film that protects the surface of optical members and electronic material members.

[0015] The present invention is described below. It should be noted that the present invention is not limited to the following embodiments.

[0016] [Antistatic Agent] The antistatic agent of the present invention consists of a salt represented by formula (1). This salt consists of a halogen atom-free cation and an anion having a sulfonylimide skeleton. In formula (1), R １ each represents any one of a hydrocarbon group having 1 to 6 carbon atoms, a hydrogen atom, a nitro group, an amino group, a cyano group, a carbonyl group, a hydroxy group and an alkoxy group, and may be the same or different from each other. Further, R １ adjacent groups may be linked to each other to form an alkylene group having 2 to 6 carbon atoms. From the perspective of the balance between antistatic performance and resin compatibility, R １The group is preferably a hydrogen atom, a methyl group, a methoxy group, a nitro group, or a cyano group. Specific examples of anions having a sulfonyliide skeleton include anions of dibenzenesulfonimide compounds such as dibenzenesulfonimide, bis(4-methoxyphenylsulfonyl)imide, bis(4-nitrophenylsulfonyl)imide, bis(4-cyanophenylsulfonyl)imide, bis(2-methylphenylsulfonyl)imide, 2-methyl-N-(phenylsulfonyl)benzenesulfonamide, 4-methoxy-N-(phenylsulfonyl)benzenesulfonamide, 4-nitro-N-(phenylsulfonyl)benzenesulfonamide, and 4-cyano-N-(phenylsulfonyl)benzenesulfonamide.

[0017] In formula (1), Q ＋ This is a cation that does not contain halogen atoms. Specifically, examples of cations include metal cations such as lithium, sodium, potassium, rubidium, cesium, calcium, magnesium, strontium, barium, manganese, nickel, iron, copper, silver, gold, and zinc, as well as onium cations such as ammonium cations, phosphonium cations, sulfonium cations, piperidinium cations, pyrrolidinium cations, pyrazolium cations, pyrazolinium cations, morpholinium cations, pyridinium cations, and imidazolium cations. From the viewpoint of antistatic performance and resin compatibility, ammonium cations, pyridinium cations, and imidazolium cations are preferred.

[0018] In formula (1), Q + If Q is one of the following: ammonium cation, pyridinium cation, or imidazolium cation, + This is expressed by equations (2) to (4).

[0019] In formula (2), R ２ Each of these groups may be the same or different hydrogen atom, a linear or branched saturated hydrocarbon group having 1 to 12 carbon atoms, an unsaturated hydrocarbon group, an alkoxy group, or a hydroxyl group, and adjacent groups may be linked to form an alkylene group having 2 to 6 carbon atoms. In formulas (3) and (4), R ３ , R ４each represent hydrogen, a linear or branched alkyl group having 1 to 12 carbon atoms, an alkoxy group or a hydroxyl group, which may be the same or different.

[0020] Among the salts represented by formula (1), the antistatic agent of the present invention is preferably an imidazolium salt, a pyridinium salt or an ammonium salt of formula (5), formula (6) or formula (7).

[0021] In formulas (5) and (6), R ６ , R ７ represents a hydrocarbon group having 1 to 4 carbon atoms, and the hydrocarbon group is either linear or branched. Specifically, methyl group, ethyl group, propyl group, isopropyl group, cyclopropyl group, butyl group, s-butyl group and tert-butyl group are preferred, and methyl group is most preferred from the viewpoints of antistatic performance and resin compatibility.

[0022] R ５ , R ８ represents a hydrocarbon group having 2 to 12 carbon atoms, and the hydrocarbon group is either linear or branched. Specific examples include ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, s-butyl group, tert-butyl group, n-pentyl group, cyclopentyl group, isopentyl group, neopentyl group, tert-pentyl group, n-hexyl group, cyclohexyl group, isohexyl group, n-heptyl group, 2-ethylhexyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, and n-dodecyl group. From the viewpoint of resin compatibility, ethyl group, n-butyl group, s-butyl group, tert-butyl group, n-pentyl group, cyclopentyl group, isopentyl group, neopentyl group, tert-pentyl group, n-hexyl group, isohexyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, n-undecyl group, and n-dodecyl group are preferred. From the balance of antistatic performance and resin compatibility, n-butyl group or n-octyl group is more preferred.

[0023] In formula (7), R ９ to R １２Each of these groups represents either the same or different hydrogen atoms, a linear or branched saturated hydrocarbon group having 1 to 12 carbon atoms, an unsaturated hydrocarbon group, an alkoxy group, or a hydroxyl group, and adjacent groups may be linked to form an alkylene group having 2 to 6 carbon atoms. Specifically, examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, s-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and tridecyl groups, as well as alkyl groups in which part of the alkyl group is substituted with an alkenyl, alkynyl, or alkoxy group.

[0024] In formulas (5) to (7), R １ R represents one of the following: a hydrocarbon group having 1 to 6 carbon atoms, a hydrogen atom, a nitro group, an amino group, a cyano group, a carbonyl group, a hydroxyl group, or an alkoxy group, and these may be the same or different. １ In this case, adjacent groups may be linked together to form an alkylene group having 2 to 6 carbon atoms. １ If is a hydrocarbon group, this hydrocarbon group may be linear or branched, and specific examples include methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, s-butyl group, tert-butyl group, n-pentyl group, cyclopentyl group, isopentyl group, neopentyl group, tert-pentyl group, n-hexyl group, cyclohexyl group, isohexyl group, etc.

[0025] Among the salts represented by formulas (5) to (7), it is preferable to use, for the antistatic agent of the present invention, 1-methyl-3-butylimidazolium dibenzenesulfonimide, 1-methyl-3-octylimidazolium dibenzenesulfonimide, 1-butyl-3-methylpyridinium dibenzenesulfonimide, 1-octyl-3-methylpyridinium dibenzenesulfonimide, 1-methyl-3-octylimidazolium bis(4-methoxyphenylsulfonyl)imide, 1-methyl-3-octylimidazolium bis(4-nitrophenylsulfonyl)imide, 1-methyl-3-octylimidazolium bis(4-cyanophenylsulfonyl)imide, 1-methyl-3-octylimidazolium bis(2-methylphenylsulfonyl)imide, 1-methyl-3-octylimidazolium 2-methyl-N-(phenylsulfonyl)benzenesulfonamide, 1-methyl-3-octylimidazolium 4-methoxy-N-(phenylsulfonyl)benzenesulfonamide, 1-methyl-3-octylimidazolium 4-nitro-N-(phenylsulfonyl)benzenesulfonamide, 1-methyl-3-octylimidazolium 4-cyano-N-(phenylsulfonyl)benzenesulfonamide, tetrabutylammonium dibenzenesulfonimide, methyltrioctylammonium dibenzenesulfonimide, and octyltrimethylammonium dibenzenesulfonimide.

[0026] Q in the above formula (1) + when Q is a metal salt using a metal cation, commercially available products or those synthesized by a known method can be used as the salt. For example, for cations, metal cations may be exchanged by a metathesis reaction.

[0027] Q in the above formula (1) + when Q is an onium salt using an onium cation, the target onium compound can be subjected to a quaternization reaction with an alkyl halide to obtain an onium halide, and then obtained by a metathesis reaction with a metal salt having the skeleton. As the compounds used in this reaction, commercially available products or those synthesized by known methods can be used.

[0028] When the anion having a sulfonylimide skeleton in formula (1) above is an anion of a dibenzenesulfonimide compound, it 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.

[0029] Among the salts represented by formula (1) above, the imidazolium salt, pyridinium salt, and ammonium salt represented by formula (5), formula (6), or formula (7) can be produced using known methods to obtain the above structure. Examples of such methods include the following. The compounds used in this reaction can be commercially available or synthesized by known methods. [Methods for producing imidazolium salt, pyridinium salt, and ammonium salt]

[0030] In the imidazoles of formula (8), R ６ The alkyl group is a C1-C4 alkyl group that may be linear or branched, and examples include 1-methylimidazole, 1-ethylimidazole, 1-propylimidazole, 1-isopropylimidazole, and 1-butylimidazole.

[0031] By quaternizing imidazoles represented by formula (8) with alkyl halides represented by formula (9), onium halides represented by formula (10) are obtained. In formulas (9) to (10), X is a halide. In formula (11), M ＋ represents a metal ion. The double decomposition reaction of formulas (10) and (11) yields the imidazolium salt represented by formula (5).

[0032] In the pyridinium compounds of formula (12), R ７ This is a C1-C4 alkyl group that may be linear or branched, and examples include 3-methylpyridinium, 3-ethylpyridinium, 3-propylpyridinium, 3-isopropylpyridinium, and 3-butylpyridinium.

[0033] By quaternizing pyridinium compounds represented by formula (12) with alkyl halides represented by formula (9), onium halides represented by formula (13) are obtained. In formulas (9) and (13), X is a halide. In formula (11), M ＋ represents a metal ion. The double decomposition reaction of formulas (11) and (13) yields the pyridinium salt represented by formula (6).

[0034] In the ammonium compounds of formula (14), R ９ ~R １２ Each of these groups represents either the same or different hydrogen atoms, a linear or branched saturated hydrocarbon group having 1 to 12 carbon atoms, an unsaturated hydrocarbon group, an alkoxy group, or a hydroxyl group, and adjacent groups may be linked to form an alkylene group having 2 to 6 carbon atoms. Specifically, examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, s-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and tridecyl groups, as well as alkyl groups in which part of the alkyl group is substituted with an alkenyl, alkynyl, or alkoxy group.

[0035] The double decomposition reaction between the ammonium compounds represented by formula (14) and formula (11) yields the ammonium salt represented by formula (7). In formula (14), X is a halide. In formula (11), M ＋ This indicates a metal ion.

[0036] Examples of alkyl halides in formula (9) include ethyl chloride, propyl chloride, butyl chloride, s-butyl chloride, tert-butyl chloride, cyclobutyl chloride, n-pentyl chloride, cyclopentyl chloride, isopentyl chloride, neopentyl chloride, tert-pentyl chloride, n-octyl chloride, isohexyl chloride, 2-ethylhexyl chloride, ethyl bromide, propyl bromide, isopropyl bromide, cyclopropyl bromide, butyl bromide, s-butyl bromide, tert-butyl bromide, cyclobutyl bromide, n-pentyl bromide, cyclopentyl bromide, isopentyl bromide, neopentyl bromide, tert-pentyl bromide, n-octyl bromide, and isohexyl Examples include bromide, 2-ethylhexyl bromide, ethyl iodide, propyl iodide, isopropyl iodide, cyclopropyl iodide, butyl iodide, s-butyl iodide, tert-butyl iodide, cyclobutyl iodide, n-pentyl iodide, cyclopentyl iodide, isopentyl iodide, neopentyl iodide, tert-pentyl iodide, n-octyl iodide, isohexyl iodide, 2-ethylhexyl iodide, n-nonyl chloride, n-nonyl bromide, n-nonyl iodide, n-decyl chloride, n-decyl bromide, n-decyl iodide, n-undecyl chloride, n-undecyl bromide, n-undecyl iodide, n-dodecyl chloride, n-dodecyl bromide, and n-dodecyl iodide.

[0037] The quaternization reaction of formula (8) or formula (12) by formula (9) may or may not be carried out with or without 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 being preferred.

[0038] The amount of formula (9) used should be 0.7 moles or more per mole of formula (8) or formula (12), preferably 0.9 to 1.5 moles.

[0039] The reaction temperature in the quaternization reaction is usually 25°C or higher, preferably 30 to 150°C, and particularly preferably 60 to 120°C.

[0040] Examples of metal salts in formula (11) include lithium dibenzenesulfonimide, sodium dibenzenesulfonimide, potassium dibenzenesulfonimide, silver dibenzenesulfonimide, lithium bis(4-methoxyphenylsulfonyl)imide, sodium bis(4-methoxyphenylsulfonyl)imide, potassium bis(4-methoxyphenylsulfonyl)imide, silver bis(4-methoxyphenylsulfonyl)imide, lithium bis(4-nitrophenylsulfonyl)imide, sodium bis(4-nitrophenylsulfonyl)imide, potassium bis(4-nitrophenylsulfonyl)imide, silver bis(4-nitrophenylsulfonyl)imide, lithium bis(4-cyanophenylsulfonyl)imide, sodium bis(4-cyanophenylsulfonyl)imide, potassium bis(4-cyanophenylsulfonyl)imide, silver bis(4-cyanophenylsulfonyl)imide, lithium bis(2-methylphenylsulfonyl)imide, sodium bis(2-methylphenylsulfonyl)imide, potassium bis(2-methylphenylsulfonyl)imide, silver bis(2-methylphenylsulfonyl)imide Lithium 2-methyl-N-(phenylsulfonyl)benzenesulfonamide, sodium 2-methyl-N-(phenylsulfonyl)benzenesulfonamide, potassium 2-methyl-N-(phenylsulfonyl)benzenesulfonamide, silver 2-methyl-N-(phenylsulfonyl)benzenesulfonamide, lithium 4-methoxy-N-(phenylsulfonyl)benzenesulfonamide, sodium 4-methoxy-N-(phenylsulfonyl)benzenesulfonamide, potassium 4-methoxy-N-(phenylsulfonyl)benzenesulfonamide, silver 4-methoxy-N-(phenylsulfonyl)benzenesulfonamide, lithium 4-nitro-N-(phenylsulfonyl)benzenesulfonamide, sodium 4-nitro-N-(phenylsulfonyl)benzenesulfonamide, potassium 4-nitro-N-(phenylsulfonyl)benzenesulfonamide, silver 4-nitro-N-(phenylsulfonyl)benzenesulfonamide, lithium 4-cyano-N-(phenylsulfonyl)benzenesulfonamide, sodium 4-cyano-N-(phenylsulfonyl)benzenesulfonamide,Examples of metal salts include potassium 4-cyano-N-(phenylsulfonyl)benzenesulfonamide and silver 4-cyano-N-(phenylsulfonyl)benzenesulfonamide.

[0041] The amount of formula (11) used in the double decomposition reaction is usually 0.8 moles or more, preferably 0.9 to 1.8 moles, and more preferably 1.0 to 1.2 moles, per mole of formula (10), formula (13), or formula (14).

[0042] 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.

[0043] The mixing order of formula (10), formula (11) and solvent, or formula (13), formula (11) and solvent, or formula (14), formula (11) and solvent is not particularly limited. Formula (11) may be added after mixing formula (10), formula (13), or formula (14) with the solvent, or formula (10), formula (13), or formula (14) may be added after mixing formula (11) with the solvent.

[0044] 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.

[0045] To isolate formula (5), formula (6), or formula (7) 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 reaction solution is filtered to remove the precipitated inorganic salts, and then formula (5), formula (6), or formula (7) is isolated by combining appropriate unit operations such as concentration, filtration, and extraction. Formula (5), formula (6), or formula (7) obtained by isolation can be used as an antistatic agent.

[0046] The antistatic agent obtained in this manner is halogen-free. Furthermore, the antistatic agent of the present invention, which is a combination of an imidazolium, pyridinium, or ammonium cation and an anion of a dibenzenesulfonimide compound, has higher ionic conductivity and superior compatibility with resins and hydrophobicity compared to when other salts are selected. Therefore, it is particularly excellent in conductivity, high humidity resistance and heat properties, and good antistatic performance can be obtained.

[0047] [Adhesive Composition] By combining the antistatic agent of the present invention with an acrylic adhesive, an adhesive composition with antistatic properties can be obtained. This adhesive composition with antistatic properties can be incorporated into a resin to form an antistatic adhesive resin. This antistatic adhesive resin has excellent antistatic properties, excellent transparency, and low haze. Furthermore, this antistatic adhesive resin also has improved heat and humidity resistance. For example, when an imidazolium salt is used as the antistatic agent, the surface resistance of the antistatic adhesive resin formed from the adhesive composition is 1.0 × 10⁻⁶. 10 Ω or less, more preferably 5.0 × 10 9 The material must be less than or equal to Ω, have a transmittance of 90% or more, preferably 92% or more, and a haze value of 2.0% or less, preferably 1.5% or less. Furthermore, when a moisture and heat resistance test is performed on the antistatic adhesive resin, the surface resistance value after the test should be 1.0 × 10⁻⁶. 10 Ω or less, more preferably 5.0 × 10 9The resistance is less than or equal to Ω, the transparency is such that the transmittance is 90% or more, preferably 92% or more, and the haze value is 2.0% or less, preferably 1.5% or less. Surface resistance is measured with a resistometer, and transmittance and haze value are measured with a haze meter. In the humidity and heat resistance test, after being placed under constant temperature and humidity conditions, surface resistance can be measured with a resistometer, and transmittance and haze value can be measured with a haze meter. Therefore, the adhesive composition of the present invention contains at least the above salt and an acrylic adhesive. Adhesive inks prepared by dissolving the above adhesive composition in a soluble organic solvent are 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 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.

[0048] The acrylic adhesive in the present invention preferably contains an acrylic polymer mainly composed of an acrylate or methacrylate having an alkyl group having 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.

[0049] 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).

[0050] 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.

[0051] 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.

[0052] 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; isocyanate adducts such as trimethylolpropane / tolylene diisocyanate trimer adducts, trimethylolpropane / hexamethylene diisocyanate trimer adducts, and isocyanurates of hexamethylene diisocyanate.

[0053] Epoxy compounds are compounds having at least two epoxy groups in their molecule. Specifically, examples include bisphenol A type epoxy resins, ethylene glycol diglycidyl ethers, glycerin diglycidyl ethers, 1,6-hexanediol diglycidyl ethers, and N,N-diglycidylaniline.

[0054] 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.

[0055] 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.

[0056] 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 cohesive force of the polymer will be strong, reducing fluidity and resulting in insufficient wettability to the adherend, which can cause peeling.

[0057] 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 preferred because they have good compatibility with acrylic polymers.

[0058] Examples of surfactants containing alkylene oxide groups 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] The amount of the salt represented by formula (1) in the adhesive composition of the present invention is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5.0 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 (halogen-free).

[0063] 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.

[0064] 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. After applying these adhesive compositions or adhesive inks to substrates such as resin films or glass, and 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.

[0065] [Adhesive Ink] Examples of 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.

[0066] [Base material] Examples of base materials include polyethylene terephthalate (PET) film, polycarbonate film, polystyrene film, acrylic film, cellulose triacetate film, polyethylene film, and polypropylene film.

[0067] [Method for producing 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, the temperature is preferably 50°C to 150°C from the viewpoint of promoting the hardening of the liquid film.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] [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. Resins that can contain the antistatic agent of the present invention include, for example, 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, 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.

[0072] 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, 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, and irradiating the resin coated with this solution with ultraviolet light.

[0073] 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.

[0074] (Example 1) [Production of antistatic agent] 1-methyl-3-butylimidazolium=dibenzenesulfonimide was produced as follows.

[0075] 8.2 g of 1-methylimidazole was mixed with 14.4 g of butyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°C for 5 hours. After removing the solvent by concentration, pure water and hexane were added and liquid-liquid was carried out to remove unreacted butyl bromide, and then the mixture was concentrated to obtain 20.4 g of 1-methyl-3-butylimidazolium bromide (93% yield). 100 g of acetonitrile was added to the 20.4 g of synthesized 1-methyl-3-butylimidazolium bromide and dissolved, then 31.2 g of sodium dibenzenesulfonimide 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 40.4 g of the imidazolium salt, 1-methyl-3-butylimidazolium dibenzenesulfonimide (95% yield). This was used directly as an antistatic agent.

[0076] [Preparation of adhesive ink] - Acrylic adhesive (manufactured by Soken Chemical Co., Ltd., 2030U, non-volatile content 15%): 40g - Curing agent (isocyanate compound, manufactured by Soken Chemical Co., Ltd., Y-45, non-volatile content 75%): 0.32g - Antistatic agent (1-methyl-3-butylimidazolium=dibenzenesulfonimide): 0.12g The above composition was diluted with MEK to a non-volatile content concentration of 15 parts by mass to prepare the adhesive ink.

[0077] (Example 2) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=dibenzenesulfonimide was used instead of the imidazolium salt in Example 1.

[0078] [Manufacturing of antistatic agent] 1-methyl-3-octylimidazolium-dibenzenesulfonimide was manufactured as follows.

[0079] 8.2 g of 1-methylimidazole was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 26.1 g of 1-methyl-3-octylimidazolium bromide (95% yield). 100 g of acetonitrile was added to the 26.1 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 31.8 g of sodium dibenzenesulfonimide 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 46.84 g of the imidazolium salt, 1-methyl-3-octylimidazolium dibenzenesulfonimide (96% yield). This was used directly as an antistatic agent.

[0080] (Example 3) An adhesive ink was prepared without any changes except that 1-butyl-3-methylpyridinium-dibenzenesulfonimide was used instead of the imidazolium salt in Example 1.

[0081] [Manufacturing of antistatic agent] 1-butyl-3-methylpyridinium-dibenzenesulfonimide was manufactured as follows.

[0082] 9.3 g of 3-methylpyridine was mixed with 14.4 g of butyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 butyl bromide, and then the mixture was concentrated to obtain 21.2 g of 1-butyl-3-methylpyridinium bromide (92% yield). 100 g of acetonitrile was added to the 21.2 g of synthesized 1-butyl-3-methylpyridinium bromide and dissolved, then 30.8 g of sodium dibenzenesulfonimide 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 39.6 g of the pyridinium salt, 1-butyl-3-methylpyridinium dibenzenesulfonimide (92% yield). This was used directly as an antistatic agent.

[0083] (Example 4) An adhesive ink was prepared without any changes except that 1-octyl-3-methylpyridinium-dibenzenesulfonimide was used instead of the imidazolium salt in Example 1.

[0084] [Manufacturing of antistatic agent] 1-Octyl-3-methylpyridinium-dibenzenesulfonimide was manufactured as follows.

[0085] 9.3 g of 3-methylpyridine was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 26.9 g of 1-octyl-3-methylpyridinium bromide (yield 94%). 100 g of acetonitrile was added to the 26.9 g of synthesized 1-octyl-3-methylpyridinium bromide and dissolved, then 31.5 g of sodium dibenzenesulfonimide 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 44.9 g of the pyridinium salt, 1-octyl-3-methylpyridinium dibenzenesulfonimide (yield 91%). This was used directly as an antistatic agent.

[0086] (Example 5) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=bis(4-methoxyphenylsulfonyl)imide was used instead of the imidazolium salt of Example 1.

[0087] [Manufacturing of antistatic agent] 1-methyl-3-octylimidazolium=bis(4-methoxyphenylsulfonyl)imide was manufactured as follows.

[0088] 8.2 g of 1-methylimidazole was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 26.1 g of 1-methyl-3-octylimidazolium bromide (95% yield). 100 g of acetonitrile was added to the 26.1 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 37.8 g of sodium bis(4-methoxyphenylsulfonyl)imide 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 51.8 g of the imidazolium salt, 1-methyl-3-octylimidazolium-bis(4-methoxyphenylsulfonyl)imide (95% yield). This was used as an antistatic agent.

[0089] (Example 6) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=bis(4-nitrophenylsulfonyl)imide was used instead of the imidazolium salt of Example 1.

[0090] [Manufacturing of antistatic agent] 1-methyl-3-octylimidazolium=bis(4-nitrophenylsulfonyl)imide was manufactured as follows.

[0091] 8.2 g of 1-methylimidazole was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 26.1 g of 1-methyl-3-octylimidazolium bromide (95% yield). 100 g of acetonitrile was added to the 26.1 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 40.8 g of sodium bis(4-nitrophenylsulfonyl)imide 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 52.8 g of the imidazolium salt, 1-methyl-3-octylimidazolium=bis(4-nitrophenylsulfonyl)imide (92% yield). This was used directly as an antistatic agent.

[0092] (Example 7) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=bis(4-cyanophenylsulfonyl)imide was used instead of the imidazolium salt of Example 1.

[0093] [Manufacturing of antistatic agent] 1-methyl-3-octylimidazolium=bis(4-cyanophenylsulfonyl)imide was manufactured as follows.

[0094] 8.2 g of 1-methylimidazole was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 26.1 g of 1-methyl-3-octylimidazolium bromide (95% yield). 100 g of acetonitrile was added to the 26.1 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 36.8 g of sodium bis(4-cyanophenylsulfonyl)imide 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 48.7 g of the imidazolium salt, 1-methyl-3-octylimidazolium=bis(4-cyanophenylsulfonyl)imide (91% yield). This was used as an antistatic agent.

[0095] (Example 8) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=bis(2-methylphenylsulfonyl)imide was used instead of the imidazolium salt of Example 1.

[0096] [Manufacturing of antistatic agent] 1-methyl-3-octylimidazolium=bis(2-methylphenylsulfonyl)imide was manufactured as follows.

[0097] 8.2 g of 1-methylimidazole was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 26.1 g of 1-methyl-3-octylimidazolium bromide (95% yield). 100 g of acetonitrile was added to the 26.1 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 34.6 g of sodium bis(2-methylphenylsulfonyl)imide 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 44.2 g of the imidazolium salt, 1-methyl-3-octylimidazolium=bis(2-methylphenylsulfonyl)imide (86% yield). This was used as an antistatic agent.

[0098] (Example 9) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=2-methyl-N-(phenylsulfonyl)benzenesulfonamide was used instead of the imidazolium salt of Example 1.

[0099] [Manufacturing of antistatic agent] 1-methyl-3-octylimidazolium=2-methyl-N-(phenylsulfonyl)benzenesulfonamide was manufactured as follows.

[0100] 8.2 g of 1-methylimidazole was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°C for 5 hours. After removing the solvent by concentration, pure water and hexane were added and liquid-liquid extraction was carried out to remove unreacted octyl bromide, and then the mixture was concentrated to obtain 26.1 g of 1-methyl-3-octylimidazolium bromide (yield 95%). 100 g of acetonitrile was added to the 26.1 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 33.2 g of sodium-2-methyl-N-(phenylsulfonyl)benzenesulfonamide was added and the mixture was stirred for 2 hours. The solvent was removed by concentration, followed by liquid-liquid washing with dichloromethane and pure water. The mixture was then concentrated again to obtain 45.1 g (90% yield) of the imidazolium salt, 1-methyl-3-octylimidazolium=2-methyl-N-(phenylsulfonyl)benzenesulfonamide. This was used directly as an antistatic agent.

[0101] (Example 10) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=4-methoxy-N-(phenylsulfonyl)benzenesulfonamide was used instead of the imidazolium salt of Example 1.

[0102] [Manufacturing of antistatic agent] 1-methyl-3-octylimidazolium=4-methoxy-N-(phenylsulfonyl)benzenesulfonamide was manufactured as follows.

[0103] 8.2 g of 1-methylimidazole was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 26.1 g of 1-methyl-3-octylimidazolium bromide (yield 95%). 100 g of acetonitrile was added to the 26.1 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 34.8 g of sodium-4-methoxy-N-(phenylsulfonyl)benzenesulfonamide was added and the mixture was stirred for 2 hours. The solvent was removed by concentration, followed by liquid-liquid washing with dichloromethane and pure water. The mixture was then concentrated again to obtain 47.5 g (92% yield) of the imidazolium salt, 1-methyl-3-octylimidazolium=2-methyl-N-(phenylsulfonyl)benzenesulfonamide. This was used directly as an antistatic agent.

[0104] (Example 11) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=4-nitro-N-(phenylsulfonyl)benzenesulfonamide was used instead of the imidazolium salt of Example 1.

[0105] [Manufacturing of antistatic agent] 1-methyl-3-octylimidazolium=4-nitro-N-(phenylsulfonyl)benzenesulfonamide was manufactured as follows.

[0106] 8.2 g of 1-methylimidazole was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 26.1 g of 1-methyl-3-octylimidazolium bromide (yield 95%). 100 g of acetonitrile was added to the 26.1 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 36.3 g of sodium-4-nitro-N-(phenylsulfonyl)benzenesulfonamide was added and the mixture was stirred for 2 hours. The solvent was removed by concentration, followed by liquid-liquid washing with dichloromethane and pure water. The mixture was then concentrated again to obtain 49.4 g (93% yield) of the imidazolium salt, 1-methyl-3-octylimidazolium=4-nitro-N-(phenylsulfonyl)benzenesulfonamide. This was used directly as an antistatic agent.

[0107] (Example 12) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=4-cyano-N-(phenylsulfonyl)benzenesulfonamide was used instead of the imidazolium salt of Example 1.

[0108] [Manufacturing of antistatic agent] 1-methyl-3-octylimidazolium=4-cyano-N-(phenylsulfonyl)benzenesulfonamide was manufactured as follows.

[0109] 8.2 g of 1-methylimidazole was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 26.1 g of 1-methyl-3-octylimidazolium bromide (yield 95%). 100 g of acetonitrile was added to the 26.1 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 34.3 g of sodium-4-cyano-N-(phenylsulfonyl)benzenesulfonamide was added and the mixture was stirred for 2 hours. The solvent was removed by concentration, followed by liquid-liquid washing with dichloromethane and pure water. The mixture was then concentrated again to obtain 48.6 g (95% yield) of the imidazolium salt, 1-methyl-3-octylimidazolium=4-cyano-N-(phenylsulfonyl)benzenesulfonamide. This was used directly as an antistatic agent.

[0110] (Example 13) An adhesive ink was prepared without any changes except that tetrabutylammonium dibenzenesulfonimide was used instead of the imidazolium salt in Example 1.

[0111] [Manufacturing of antistatic agent] Tetrabutylammonium dibenzenesulfonimide was manufactured as follows:

[0112] 20.0 g of tetrabutylammonium bromide was dissolved in 100 g of acetonitrile, then 20.8 g of sodium dibenzenesulfonimide 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 31.8 g of tetrabutylammonium dibenzenesulfonimide (95% yield), which is the ammonium salt. This was used directly as an antistatic agent.

[0113] (Example 14) An adhesive ink was prepared without any changes except that methyltrioctylammonium dibenzenesulfonimide was used instead of the imidazolium salt in Example 1.

[0114] [Manufacturing of antistatic agent] Methyltrioctylammonium dibenzenesulfonimide was manufactured as follows:

[0115] 20.0 g of methyltrioctylammonium bromide was dissolved in 100 g of acetonitrile, then 14.9 g of sodium dibenzenesulfonimide 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 27.6 g of methyltrioctylammonium dibenzenesulfonimide (93% yield), which is the ammonium salt. This was used directly as an antistatic agent.

[0116] (Example 15) An adhesive ink was prepared without any changes except that octyltrimethylammonium dibenzenesulfonimide was used instead of the imidazolium salt in Example 1.

[0117] [Manufacturing of antistatic agent] Octyltrimethylammonium dibenzenesulfonimide was manufactured as follows.

[0118] 20.0 g of octyltrimethylammonium bromide was dissolved in 100 g of acetonitrile, then 26.6 g of sodium dibenzenesulfonimide 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 31.5 g of methyltrioctylammonium dibenzenesulfonimide (81% yield), which is the ammonium salt. This was used directly as an antistatic agent.

[0119] (Comparative Example 1) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=p-toluenesulfonic acid was used instead of the imidazolium salt of Example 1. [Preparation of Antistatic Agent] 1-methyl-3-octylimidazolium=p-toluenesulfonic acid was prepared as follows.

[0120] 8.2 g of 1-methylimidazole was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 octyl bromide, and then the mixture was concentrated to obtain 26.1 g of 1-methyl-3-octylimidazolium bromide (95% yield). 100 g of acetonitrile was added to the 26.1 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 19.4 g of sodium p-toluenesulfonate 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 29.2 g of 1-methyl-3-octylimidazolium-p-toluenesulfonic acid (84% yield). This was used directly as an antistatic agent.

[0121] (Comparative Example 2) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=dodecylbenzenesulfonic acid was used instead of the imidazolium salt of Example 1.

[0122] [Manufacturing of antistatic agent] 1-methyl-3-octylimidazolium-dodecylbenzenesulfonic acid was manufactured as follows.

[0123] 8.2 g of 1-methylimidazole was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 26.1 g of 1-methyl-3-octylimidazolium bromide (95% yield). 100 g of acetonitrile was added to the 26.1 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 34.8 g of sodium dodecylbenzenesulfonate 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 41.2 g of 1-methyl-3-octylimidazolium-dodecylbenzenesulfonic acid (80% yield). This was used directly as an antistatic agent.

[0124] (Comparative Example 3) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=methanesulfonylimide was used instead of the imidazolium salt of Example 1.

[0125] [Manufacturing of antistatic agent] 1-methyl-3-octylimidazolium=methanesulfonylimide was manufactured as follows.

[0126] 8.2 g of 1-methylimidazole was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 octyl bromide, and then the mixture was concentrated to obtain 26.1 g of 1-methyl-3-octylimidazolium bromide (95% yield). 100 g of acetonitrile was added to the 26.1 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 17.3 g of sodium methanesulfonylimide 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 30.0 g of 1-methyl-3-octylimidazolium methanesulfonylimide (86% yield). This was used as an antistatic agent.

[0127] (Comparative Example 4) An adhesive ink was prepared without any changes except that 1-methyl-3-octylimidazolium=bisoxalatoborate was used instead of the imidazolium salt of Example 1.

[0128] [Manufacturing of antistatic agent] 1-methyl-3-octylimidazolium=bisoxalatoborate was manufactured as follows.

[0129] 8.2 g of 1-methylimidazole was mixed with 20.3 g of octyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 26.1 g of 1-methyl-3-octylimidazolium bromide (95% yield). 100 g of acetonitrile was added to the 26.1 g of synthesized 1-methyl-3-octylimidazolium bromide and dissolved, then 19.3 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 33.0 g of 1-methyl-3-octylimidazolium bisoxalatoborate (91% yield). This was used directly as an antistatic agent.

[0130] (Comparative Example 5) An adhesive ink was prepared without any changes except that 1-butyl-3-methylpyridinium=p-toluenesulfonic acid was used instead of the imidazolium salt of Example 1.

[0131] [Manufacturing of antistatic agent] 1-butyl-3-methylpyridinium=p-toluenesulfonic acid was manufactured as follows.

[0132] 9.3 g of 3-methylpyridine was mixed with 14.4 g of butyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 butyl bromide, and then the mixture was concentrated to obtain 21.2 g of 1-butyl-3-methylpyridinium bromide (92% yield). 100 g of acetonitrile was added to the 21.2 g of synthesized 1-butyl-3-methylpyridinium bromide and dissolved, then 18.8 g of sodium p-toluenesulfonate 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 23.7 g of 1-butyl-3-methylpyridinium-p-toluenesulfonic acid (80% yield). This was used directly as an antistatic agent.

[0133] (Comparative Example 6) An adhesive ink was prepared without any changes except that 1-butyl-3-methylpyridinium=bisoxalatoborate was used instead of the imidazolium salt of Example 1.

[0134] [Manufacturing of antistatic agent] 1-butyl-3-methylpyridinium=bisoxalatoborate was manufactured as follows.

[0135] 9.3 g of 3-methylpyridine was mixed with 14.4 g of butyl bromide and 20 g of acetonitrile, and the mixture was heated and stirred at 80°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 butyl bromide, and then the mixture was concentrated to obtain 21.2 g of 1-butyl-3-methylpyridinium bromide (92% yield). 100 g of acetonitrile was added to the 21.2 g of synthesized 1-butyl-3-methylpyridinium bromide and dissolved, then 18.7 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 28.5 g of 1-butyl-3-methylpyridinium bisoxalatoborate (92% yield). This was used directly as an antistatic agent.

[0136] [Coating Conditions] The adhesive ink was coated onto a 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 a test specimen (adhesive film).

[0137] [Surface Resistance Measurement] Using the Hi-Lester UP (manufactured by Mitsubishi Chemical Analytech Co., Ltd., product name "MCP-HT450"), the probe was pressed against the coated surface of the test piece at a temperature of 23±2°C, humidity of 50±5%RH, and applied voltage of 100V, and the stable surface resistance value was measured after 30 seconds.

[0138] [Measurement of Transmittance and Haze Value] The total light transmittance and haze on the adhesive layer side of the adhesive film after the separator was removed were measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "NDH5000").

[0139] [Humidity and Heat Resistance Test] The prepared test specimens were placed in a constant temperature chamber at 60°C and 85% humidity for 500 hours, and the surface resistance, total light transmittance, and haze value were compared before and after the test.

[0140] Table 1 shows the results before the humidity and heat resistance test for Examples 1 to 15 and Comparative Examples 1 to 6, and Table 2 shows the results after the humidity and heat resistance test.

[0141]

[0142]

[0143] As described above, the adhesive compositions of Examples 1 to 15 of the present invention maintain a sufficient surface resistance value (1 × 10⁻¹⁰) even after the humid heat resistance test, making them suitable as antistatic adhesive films (antistatic adhesive resins). 10 It had a surface resistance of less than Ω and also met the criteria for resin compatibility, which are a haze value of 2.0% or less and a transmittance of 90% or more. On the other hand, Comparative Examples 1, 2, 3, and 5 all failed to meet the criteria for surface resistance, haze value, and transmittance, and Comparative Examples 4 and 6 significantly exceeded the criteria for surface resistance, haze value, and transmittance after the humid heat resistance test, indicating a lack of the performance required for an antistatic adhesive resin.

[0144] In Comparative Examples 1 and 2, which are halogen-free sulfonic acid anions, poor compatibility with adhesives prevents them from achieving sufficient antistatic performance. Furthermore, comparing Example 2 and Comparative Example 3, the onium salt in Comparative Example 3, despite having the same sulfonylimide skeleton, exhibits poor compatibility with adhesives and a structure susceptible to hydrolysis, which is likely the reason for the performance degradation in the heat and humidity resistance test. In Comparative Examples 4 and 6, while good compatibility with adhesives and sufficient antistatic performance were observed before the heat and humidity resistance test, the performance degradation after the test is thought to be due to hydrolysis of the boron complex anion. Therefore, it is believed that a specific onium salt, including those in the embodiments of the present invention, satisfies both surface resistance and resin compatibility requirements and is effective.

[0145] 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 a salt represented by formula (1). (In formula (1), Q ＋ R is a cation that does not contain a halogen atom, １ R represents one of the following: a hydrocarbon group having 1 to 6 carbon atoms, a hydrogen atom, a nitro group, an amino group, a cyano group, a carbonyl group, a hydroxyl group, or an alkoxy group, and these may be the same or different. １ (The adjacent groups may be linked together to form an alkylene group having 2 to 6 carbon atoms.) 2. The above Q + The antistatic agent according to claim 1, wherein is one of the cations of formulas (2) to (4). (In formula (2), R ２ Each of these groups may be the same or different hydrogen atom, a linear or branched saturated hydrocarbon group having 1 to 12 carbon atoms, an unsaturated hydrocarbon group, an alkoxy group, or a hydroxyl group, and adjacent groups may be linked to form an alkylene group having 2 to 6 carbon atoms. In formulas (3) and (4), R ３ , R ４ (Each of these represents either a hydrogen atom (which may be the same or different), a linear or branched alkyl group having 1 to 12 carbon atoms, an alkoxy group, or a hydroxyl group.) 3. An antistatic resin characterized by containing the antistatic agent and resin described in claims 1 to 2.

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

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

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