Salt compound, a thermal acid generator or cationic polymerization initiator containing the salt compound, a curable composition containing the salt compound, and a cured product thereof.

Abstract

To provide a novel salt compound that can function as a thermal acid generator or a cationic polymerization initiator, a novel thermal acid generator, a novel cationic polymerization initiator, a curable composition containing the salt compound, or a cured product of the curable composition. 【Solution means】The salt of the present invention is a salt represented by the following formula (1). In the following formula (1), EWG represents an electron-withdrawing group, and R 4 , 3 , 4 , 4 , , - and R 2 independently represent an alkyl group, and R 1 and R 2 may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded. R 3 represents an alkyl group, R 4 represents an alkyl group or an alkoxy group, R 3 and R 4 may be bonded to each other to form a ring together with each atom in formula (1) to which they are bonded. In that case, R 4 may be an ether group (-O-), n represents an integer of 0 to 4, and X - represents a non-nucleophilic anion. TIFF2026123104000020.tif38170

Description

[Technical Field]

[0001] The present invention relates to a novel salt compound, a thermal acid generator or cationic polymerization initiator containing the salt compound, a curable composition containing the salt compound, and a cured product thereof. [Background technology]

[0002] A thermal acid generator decomposes upon heating to generate acid, which then initiates cationic polymerization of, for example, cationic polymerizable compounds. Thermal acid generators with such properties are used as materials for optical products, electronic products, and the like. Specifically, thermal acid generators are used as raw materials for anisotropic conductive films; connectors that can join electronic components equipped with fine-pitch electrodes; focusing lenses provided in image sensors of solid-state image sensors used in cameras, video cameras, etc.; adhesive films for circuit connections; encapsulants for image display devices; encapsulants for display elements; curable resin compositions that can be blackened; and adhesive compositions (Patent Documents 1-8).

[0003] Furthermore, the applicant has disclosed an acid generator comprising a salt (1) of a cation represented by the following formula (c-1) and an anion represented by the following formula (a-1) or (a-2) (Patent Document 9). [ka] (In formula (c-1), R 1 , R 2 , R 3 R represents an alkyl group having 1 to 6 carbon atoms, either identical or different. In formula (a-1), R f 11 R represents a fluoroalkyl group, and s represents an integer from 1 to 5. In formula (a-2), R f 12 (where represents a fluoroalkyl group, a fluoroaryl group, or a fluoroalkyl-substituted aryl group, t is an integer from 1 to 4, and u is 0 or 1)

[0004] On the other hand, Patent Document 10 reports a method for producing an onium compound having a specific structure. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2017-152354 [Patent Document 2] Japanese Patent Publication No. 2021-68842 [Patent Document 3] Japanese Patent Publication No. 2022-100724 [Patent Document 4] International Publication No. 2022 / 009846 [Patent Document 5] International Publication No. 2022 / 024616 [Patent Document 6] International Publication No. 2022 / 080372 [Patent Document 7] Japanese Patent Publication No. 2023-175317 [Patent Document 8] Japanese Patent Publication No. 2024-107759 [Patent Document 9] International Publication No. 2024 / 042952 [Patent Document 10] Japanese Patent Publication No. 2017-52759 [Overview of the project] [Problems that the invention aims to solve]

[0006] Here, depending on the type of thermal acid generator used for curing, if polymerization and curing of cationic polymerizable compounds are possible at low temperatures, thermal damage to surrounding materials can be reduced. Furthermore, the energy required for heating during curing is reduced, improving the productivity of cured products. Therefore, thermal acid generators exhibiting low-temperature curing properties are in demand.

[0007] An object of the present invention is to provide a novel salt compound that can function as a thermal acid generator or a cationic polymerization initiator, a novel thermal acid generator, a novel cationic polymerization initiator, a curable composition containing the salt compound, or a cured product of the curable composition. The thermal acid generator and the cationic polymerization initiator preferably exhibit low-temperature curability, and more preferably, in addition to low-temperature curability, they have excellent thermal stability.

Means for Solving the Problems

[0008] As a result of intensive studies to solve the above problems, the present inventors have found that an onium salt compound having a specific structure is useful as a thermal acid generator or a cationic polymerization initiator. The present invention has been completed based on this finding.

[0009] That is, the present invention provides a salt represented by the following formula (1).

Chemical formula

[0010] In the salt, it is preferable that the EWG is a group having a carbonyl group.

[0011] In the salt, it is preferable that the EWG is one or more groups selected from acyl groups, ester groups, and amide groups.

[0012] In the aforementioned salt, R 3 It is preferable that the group is a methyl group.

[0013] In the salt, the EWG is one or more groups selected from an acyl group, a group having an ester group, and a group having an amide group, and the R 3 It is preferable that the group is a methyl group.

[0014] The present invention also provides a thermal acid generator or cationic polymerization initiator containing the salt.

[0015] The present invention also provides a curable composition comprising the salt and a cationic polymerizable compound.

[0016] In the curable composition, the cationic polymerizable compound is preferably a compound having one or more cationic curable groups selected from the group consisting of epoxy groups, oxetanyl groups, and vinyl ether groups.

[0017] The present invention also provides a cured product of the curable composition. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a novel salt compound that can function as a thermal acid generator or a cationic polymerization initiator, a novel thermal acid generator, a novel cationic polymerization initiator, a curable composition containing the salt compound, or a cured product of the curable composition. The thermal acid generator and the cationic polymerization initiator preferably exhibit low-temperature curability, and more preferably, in addition to low-temperature curability, have excellent thermal stability. [Modes for carrying out the invention]

[0019] [salt] The present invention provides a salt represented by the following formula (1). [ka] [In formula (1), EWG indicates an electron-withdrawing group. R 1 and R 2 These are identical or different, indicating an alkyl group. R 1 and R 2 These may be bonded to each other, forming a ring with the nitrogen atom to which they are bonded. R 3 This indicates an alkyl group. R 4 This represents an alkyl group or an alkoxy group. R 3 and R 4 They may be bonded to each other, forming a ring with each atom in formula (1) to which they are bonded, in which case R 4 It may also be an ether group (-O-), n represents an integer from 1 to 4. X - This represents a non-nucleophilic anion.

[0020] In formula (1) above, EWG represents an electron-withdrawing group. An electron-withdrawing group is a substituent that attracts electrons more readily from the bonding atom than a hydrogen atom. The position of EWG may be ortho, meta, or para relative to the carbon atom on the benzene ring bonded to the nitrogen atom.

[0021] Examples of EWGs (electron-withdrawing groups) include (a1) a monovalent group in which the carbon atom of a carbonyl group (-CO-) is bonded to an organic group such as a group selected from group A below (corresponding to "acyl group" in this specification), a monovalent group in which the carbon atom or oxygen atom of an ester group (-COO-) is bonded to an organic group such as a group selected from group B below (corresponding to "group having an ester group" in this specification), and an amide group in which the two bonds of the nitrogen atom are bonded, either identically or differently, to a group selected from group C below (the groups selected from group C below may be bonded to each other to form a ring r together with the nitrogen atom of the amide group). (i) Monovalent groups (corresponding to "groups having an amide group" in this specification), groups having a carbonyl group (-CO-) such as a formyl group and a carboxyl group; (a2) Monovalent groups in which one bond of an ether (-O-) group is bonded to an organic group such as a group selected from group D below; (a3) ​​Monovalent groups in which the sulfur atom of a sulfonyloxy group (-OSO2-) is bonded to an organic group such as a group selected from group E below: (a4) Hydroxyl group (-OH); (a5) Cyano group; (a6) Halogen group; (a7) Halogen-substituted alkyl group; (a8) Nitro group; (a9) Sulfonic acid group (-SO3H); and other monovalent groups.

[0022] (Group A) A group selected from the group consisting of alkyl groups; aryl groups; monovalent heterocyclic groups; aryl groups substituted with alkyl groups, alkoxy groups, monovalent heterocyclic groups, etc.; monovalent heterocyclic groups substituted with alkyl groups, alkoxy groups, aryl groups, etc.; and alkyl groups substituted with alkoxy groups, monovalent heterocyclic groups, aryl groups, hydroxyl groups, etc.

[0023] The group in group A is preferably a group selected from the group consisting of alkyl groups and aryl groups.

[0024] The group in group A is more preferably a group selected from the group consisting of alkyl groups having 1 to 8 carbon atoms and aromatic hydrocarbon groups having 6 to 10 carbon atoms.

[0025] (Group B) A group selected from the group consisting of alkyl groups; alkoxy groups (when bonded to the carbon atom of an ester group); aryl groups; monovalent heterocyclic groups; aryl groups substituted with alkyl groups, alkoxy groups, monovalent heterocyclic groups, etc.; and alkyl groups substituted with alkoxy groups, monovalent heterocyclic groups, aryl groups, hydroxyl groups, etc.

[0026] The group in group B is preferably a group selected from the group consisting of alkyl groups and aryl groups.

[0027] The group in group B is more preferably a group selected from the group consisting of alkyl groups having 1 to 8 carbon atoms and aromatic hydrocarbon groups having 6 to 10 carbon atoms.

[0028] (Group C) A group selected from the group consisting of alkyl groups; aryl groups; monovalent heterocyclic groups; aryl groups substituted with alkyl groups, alkoxy groups, monovalent heterocyclic groups, etc.; monovalent heterocyclic groups substituted with alkyl groups, alkoxy groups, aryl groups, etc.; alkyl groups substituted with alkoxy groups, monovalent heterocyclic groups, aryl groups, hydroxyl groups, etc.; and hydrogen atoms.

[0029] The group C is preferably a group selected from the group consisting of alkyl groups; aryl groups; alkyl groups substituted with hydroxyl groups, etc.; and hydrogen atoms.

[0030] The group C is more preferably a group selected from the group consisting of C1-C8 alkyl groups; C6-C10 aromatic hydrocarbon groups; C1-C8 alkyl groups substituted with hydroxyl groups, etc.; and hydrogen atoms.

[0031] (Group D) A group selected from the group consisting of alkyl groups; aryl groups; monovalent heterocyclic groups; alkyl groups substituted with alkoxy groups, monovalent heterocyclic groups, aryl groups, hydroxyl groups, etc.; aryl groups substituted with alkyl groups, alkoxy groups, monovalent heterocyclic groups, etc.; and monovalent heterocyclic groups substituted with alkyl groups, alkoxy groups, aryl groups, etc.

[0032] The group D is preferably a group selected from the group consisting of alkyl groups; monovalent heterocyclic groups; and alkyl groups substituted with alkoxy groups, etc.

[0033] The group D is more preferably a group selected from the group consisting of: alkyl groups having 1 to 8 carbon atoms; a group obtained by removing one hydrogen atom from the structural formula of a 3 to 10-membered aromatic heterocycle or non-aromatic heterocycle having a carbon atom and at least one heteroatom (e.g., oxygen, sulfur, nitrogen, phosphorus, etc.) as atoms constituting the ring; and alkyl groups having 1 to 8 carbon atoms substituted with an alkoxy group of 1 to 8 carbon atoms, etc.

[0034] (Group E) A group selected from the group consisting of alkyl groups; aryl groups; monovalent heterocyclic groups; alkyl groups substituted with alkoxy groups, monovalent heterocyclic groups, aryl groups, hydroxyl groups, etc.; aryl groups substituted with alkyl groups, alkoxy groups, monovalent heterocyclic groups, etc.; and monovalent heterocyclic groups substituted with alkyl groups, alkoxy groups, aryl groups, etc.

[0035] The group in group E is preferably a group selected from the group consisting of alkyl groups; aryl groups; and aryl groups substituted with alkyl groups, etc.

[0036] The group E is more preferably a group selected from the group consisting of C1-C8 alkyl groups; C6-C10 aromatic hydrocarbon groups; and C6-C10 aromatic hydrocarbon groups substituted with C1-C8 alkyl groups, etc.

[0037] Ring r is preferably a three-membered ring such as an aziridine ring; a four-membered ring such as an azetidine ring; a five-membered ring such as a pyrrole ring, pyrrolidine ring, pyrazole ring, imidazole ring, or triazole ring; a six-membered ring such as an isocyanuric ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperidine ring, morpholine ring, or piperazine ring; or a condensed ring such as an indole ring, indoline ring, quinoline ring, acridine ring, naphthyridine ring, quinazoline ring, or purine ring, more preferably a six-membered ring, and even more preferably a piperidine ring or piperazine ring.

[0038] The alkyl groups in groups A to E are preferably linear alkyl groups having 1 to 30 carbon atoms, or cyclic alkyl groups having 3 to 30 carbon atoms. Examples of linear alkyl groups having 1 to 30 carbon atoms include linear alkyl groups such as methyl, ethyl, propyl, butyl, hexadecyl, and ocdadecyl groups, and branched alkyl groups such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, and isohexyl groups. Examples of cyclic alkyl groups having 3 to 30 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. The number of carbon atoms in the linear alkyl group is preferably 1 to 12, more preferably 1 to 8, even more preferably 1 to 6, particularly preferably 1 or 2, and most preferably 1. The number of carbon atoms in the cyclic alkyl group is preferably 3 to 12, and more preferably 3 to 6.

[0039] The alkoxy groups in groups A to E are preferably alkoxy groups having 1 to 30 carbon atoms. Examples of alkoxy groups having 1 to 30 carbon atoms include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, octyloxy, and dodecyloxy groups. The number of carbon atoms in the alkoxy group is preferably 1 to 18, more preferably 1 to 8, even more preferably 1 to 6, and particularly preferably 1 to 4.

[0040] The aryl groups in groups A to E are, for example, aromatic hydrocarbon groups having 6 to 10 carbon atoms, such as phenyl groups, 1-naphthyl groups, and 2-naphthyl groups.

[0041] The monovalent heterocyclic groups in groups A to E are groups obtained by removing one hydrogen atom from the structural formula of a heterocycle. The heterocycles include aromatic heterocycles and non-aromatic heterocycles. Examples of such heterocycles include monocyclic aromatic heterocycles and non-aromatic heterocycles (preferably 3 to 20-membered rings, more preferably 3 to 10-membered rings, and even more preferably 4 to 6-membered rings) having carbon atoms and at least one heteroatom (e.g., oxygen, sulfur, nitrogen, phosphorus, etc.) as atoms constituting the ring, and fused rings in which one or more aromatic hydrocarbon rings are fused to the monocyclic aromatic heterocycle. Aromatic heterocycles specifically include heterocycles containing an oxygen atom as a heteroatom (for example, three-membered rings such as oxirane rings; four-membered rings such as oxetane rings; five-membered rings such as furan rings, tetrahydrofuran rings, oxazole rings, isoxazole rings, and γ-butyrolactone rings; six-membered rings such as 4-oxo-4H-pyran rings, tetrahydropyran rings, and morpholine rings; condensed rings such as benzofuran rings, isobenzofuran rings, 4-oxo-4H-chromene rings, chroman rings, and isochroman rings; and 3-oxatricyclo[4.3.1.1 4,8 ]Undecane-2-one ring, 3-oxatricyclo[4.2.1.0 4,8Examples include bridged rings such as nonane-2-one rings, heterocycles containing a sulfur atom as a heteroatom (e.g., five-membered rings such as thiophene rings, thiazole rings, isothiazole rings, and thiadiazole rings; six-membered rings such as 4-oxo-4H-thiopyran rings; condensed rings such as benzothiophene rings, etc.), and heterocycles containing a nitrogen atom as a heteroatom (e.g., three-membered rings such as aziridine rings; four-membered rings such as azetidine rings; five-membered rings such as pyrrole rings, pyrrolidine rings, pyrazole rings, imidazole rings, and triazole rings; six-membered rings such as isocyanuric rings, pyridine rings, pyridazine rings, pyrimidine rings, pyrazine rings, piperidine rings, morpholine rings, and piperazine rings; condensed rings such as indole rings, indoline rings, quinoline rings, acridine rings, naphthyridine rings, quinazoline rings, and purine rings, etc.).

[0042] The number of carbon atoms in the groups (a1) to (a3) ​​is preferably 1 to 10, and more preferably 1 to 9.

[0043] Examples of halogen groups in the aforementioned EWG include fluoro groups, chloro groups, bromo groups, and iodine groups.

[0044] The electron-withdrawing group (EWG) is preferably a carbonyl group (-CO-) such as an acyl group, an ester group, or an amide group, or a cyano group.

[0045] R in equation (1) above 1 ~R 4 For details of the alkyl group in formula (1), refer to the explanation of the alkyl group in groups A, B, and C. In particular, R in formula (1) 1 and R 2 Preferably, these are the same or different alkyl groups having 1 to 4 carbon atoms.

[0046] The aforementioned R 1 and R 2These atoms may or may not be bonded to each other, forming a ring with the nitrogen atom to which they are bonded. Examples of such rings include 3-6 membered aliphatic heterocycles containing at least one nitrogen atom, such as aziridine rings, azetidine rings, pyrrolidine rings, piperidine rings, morpholine rings, and piperazine rings.

[0047] R in equation (1) above 4 For information on the alkoxy groups in groups A to E, please refer to the descriptions of the alkoxy groups in groups A to E.

[0048] In formula (1), n ​​may be an integer between 0 and 4, and is preferably an integer between 0, 1, or 2. 4 The position of the carbon atom bonded to the methylene group in formula (1) may be the same as or different from the ortho position or the meta position.

[0049] R 3 and R 4 These atoms may or may not be bonded to each other, forming a ring with each atom in formula (1) to which they are bonded. 3 and R 4 If they bond to each other and form a ring with each atom in formula (1) to which they bond, then R 4 R may be an ether group (-O-), and also R 3 and R 4 The number of carbon atoms is preferably 1 to 8, -R 3 -R 4 Specifically, -CH2O-, -CH2CH2O-, -CH2CH2-, -CH2CH2CH2-, etc.

[0050] The aforementioned EWG, R 1 , and R 2 Specific preferred combinations are shown in Tables 1-3 below. In the tables below, Me represents a methyl group, Et represents an ethyl group, n-Pr represents a n-propyl group, n-Bu represents a n-butyl group, and Ph represents a phenyl group.

[0051] [Table 1]

[0052] [Table 2]

[0053] [Table 3]

[0054] The aforementioned R 3 , and R 4 Specific preferred combinations are shown in Table 4 below. In the table below, Me represents a methyl group, Et represents an ethyl group, and Bu represents a n-butyl group.

[0055] [Table 4]

[0056] The non-nucleophilic anion (X) in equation (1) above - Examples of these include halogen oxoate anions, boron anions, phosphate anions, sulfonate anions, sulfonylimide anions, carboxylate anions, gallate anions, methide anions, antimony anions, OH - SCN - NO2 - NO3 - These are some examples.

[0057] Examples of the halogen oxo acid anion include ClO4. - IO3 - , BrO3 - These are some examples.

[0058] Examples of the boron anion include BF4. - Inorganic boron anions such as (C6F5)4B - ,((CF3)2C6H3)4B -Examples of organoboron anions include tetraphenylborate, tetrakis(monofluorophenyl)borate, tetrakis(difluorophenyl)borate, and tetrakis(trifluorophenyl)borate.

[0059] Examples of the phosphate anion include PF6 - , PO4 3- Inorganic phosphate anions such as (CF3CF2)5PF - , (CF3CF2)4PF2 - (CF3CF2)3PF3 - (CF3CF2)2PF4 - , (CF3CF2)PF5 - Examples of organic phosphate anions include the following.

[0060] The aforementioned sulfonate anion can be represented, for example, by the following formula (s1). R s1 -SO3 - (s1) (In the formula, R s1 (This indicates an organic group.)

[0061] R s1 Examples of organic groups in this include hydrocarbon groups having 1 to 30 carbon atoms, which may have substituents, heterocyclic groups, and two or more of the above groups connected by a single bond, or by -O-, -CO2-, -S-, -SO3-, and -SO2N(R s2 Examples include groups linked by a linking group selected from ). Examples of substituents include halogen atoms such as fluorine atoms.

[0062] The aforementioned R s2 is a hydrogen atom or an alkyl group (for example, C 1-30 (Indicates an alkyl group.)

[0063] Examples of the substituents include halogen atoms such as fluorine atoms.

[0064] The aforementioned hydrocarbon groups having 1 to 30 carbon atoms include aliphatic hydrocarbon groups having 1 to 30 carbon atoms, alicyclic hydrocarbon groups having 3 to 30 carbon atoms, aromatic hydrocarbon groups having 6 to 30 carbon atoms, and groups formed by the bonding of two of these groups.

[0065] Preferred C1-C30 hydrocarbon groups include C1-C30 alkyl groups, C2-C30 alkenyl groups, C6-C15 aryl groups, C6-C15 cycloalkylene groups, C6-C15 bridged cyclic hydrocarbon groups, and groups formed by bonding two of these groups.

[0066] The aforementioned heterocyclic group is a group obtained by removing one hydrogen atom from the structural formula of a heterocycle. The aforementioned heterocycles include aromatic heterocycles and non-aromatic heterocycles. Examples of such heterocycles include 3- to 10-membered rings (preferably 4- to 6-membered rings) having carbon atoms and at least one heteroatom (e.g., oxygen atom, sulfur atom, nitrogen atom, etc.) as atoms constituting the ring, and fused rings thereof.

[0067] A specific example of the sulfonic acid anion is CH3SO3 - , C4H9SO3 - CF3SO3 - (TfO - ), C2F5C4H4SO3 - , C4F9SO3 - Examples include benzenesulfonate anions, p-toluenesulfonate anions, and camphorsulfonate anions.

[0068] Examples of the aforementioned sulfonylimide anion include the sulfonylimide anion represented by the following formula (n1). (R n1 SO2)2N - (n1) (In the formula, two R n1 (These are the same or different, and represent organic groups.)

[0069] R n1 As for organic groups in this context, R s1 Similar examples can be given to organic groups in the context of [the subject].

[0070] Specific examples of the sulfonylimide anion include (FSO2)2N - , (CF3SO2)2N - , (C4F9SO2)2N - , (C2F5SO2)2N - and the like.

[0071] The carboxylic acid anion is represented by, for example, the following formula (c1). R c1 -COO - (c1) (In the formula, R c1 represents an organic group)

[0072] R c1 Examples of the organic group in s1 are the same as those of the organic group in

[0073] Specific examples of the carboxylic acid anion include, for example, CF3CO2 - , CH3CO2 - , C2H5CO2 - , PhCO2 - and the like.

[0074] The gallate anion is represented by, for example, the following formula (g1). (R g1 ) t (F) 4-t Ga (g1) (In the formula, R g1 represents a fluoroalkyl group, a fluoroaryl group, or a fluoroalkyl-substituted aryl group, and t represents an integer of 1 to 4)

[0075] R g1 The fluoroalkyl group in 1-5 is a group in which at least one hydrogen atom bonded to the alkyl group is substituted with a fluorine atom, and among them, a perfluoroalkyl group is preferable, a perfluoroC 1-3 alkyl group is particularly preferable, and a perfluoroC

[0076] R g1 In this context, the fluoroaryl group is a group in which at least one of the hydrogen atoms bonded to the aryl group is replaced by a fluorine atom. The aryl group is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group or a naphthyl group, with the phenyl group being particularly preferred.

[0077] R g1 Among the fluoroaryl groups in this, perfluoroaryl groups are preferred, and perfluoroC 6-14 Aryl groups are particularly preferred, and perfluorophenyl groups are most preferred.

[0078] R g1 In this context, a fluoroalkyl-substituted aryl group is an aryl group having a substituent in which at least one hydrogen atom bonded to an alkyl group is substituted with a fluorine atom.

[0079] R g1 Among the fluoroalkyl-substituted aryl groups in this context, perfluoroalkyl-substituted aryl groups are preferred, and perfluoroC 1-5 Alkyl-substituted aryl groups are more preferred, and perfluoroC 1-3 Alkyl-substituted C 6-14 Phenyl groups are particularly preferred.

[0080] Furthermore, the number of fluoroalkyl groups in the fluoroalkyl-substituted aryl group in Rg1 is, for example, 1 to 5, preferably 1 to 3, and particularly preferably 1 or 2.

[0081] In formula (g1), t represents an integer from 1 to 4, preferably an integer from 2 to 4, particularly preferably 3 or 4, and most preferably 4.

[0082] Examples of the gallium anion include tetrafluorogallium anion and tetrakis(pentafluorophenyl)gallium anion ((C6F5)4Ga -); Tetrakis[fluorophenyl]gallium anions such as tetrakis(4-fluorophenyl)gallium anion; Tetrakis[difluorophenyl]gallium anions such as tetrakis(3,5-difluorophenyl)gallium anion; Tris(pentafluorophenyl)fluorogallium anion, bis(pentafluorophenyl)difluorogallium anion, (pentafluorophenyl)trifluorogallium anion; Tetrakis[(C)[4-(trifluoromethyl)phenyl]gallium anion 1-5 Haloalkyl)phenyl]gallium anion; tetrakis[3,5-bis(trifluoromethyl)phenyl]gallium anion, etc. 1-5 Tris[(C)(4-(trifluoromethyl)phenyl]gallium anion; Tris[(C)(4-(trifluoromethyl)phenyl]fluorogallium anion, etc. 1-5 Haloalkyl)phenyl]fluorogallium anion, etc.; Tris[3,5-bis(trifluoromethyl)phenyl]fluorogallium anion, etc. 1-5 Haloalkyl)phenyl]fluorogallium anion, etc.; bis[(C)[(4-(trifluoromethyl)phenyl]difluorogallium anion, etc. 1-5 Haloalkyl)phenyl]difluorogallium anion; bis[3,5-bis(trifluoromethyl)phenyl]difluorogallium anion, etc. 1-5 [(C)(alkyl)phenyl]difluorodifluorogallium anion; [4-(trifluoromethyl)phenyl]trifluorogallium anion, etc. 1-5 [Haloalkyl)phenyl]trifluorogallium anion; [3,5-bis(trifluoromethyl)phenyl]trifluorogallium anion, etc. [bis(C 1-5 Examples include haloalkyl)phenyl]trifluorogallium acid anions.

[0083] Examples of the methide anion include the sulfonylmethide anion represented by the following formula (m1). (R m1SO2)3C - (m1) (In the formula, three R m1 (These are the same or different, and represent organic groups.)

[0084] R m1 As for organic groups in this context, R s1 Similar examples can be given to organic groups in the context of [the subject].

[0085] A specific example of the aforementioned methido anion is (CF3SO2)3C - These are some examples.

[0086] Examples of the antimony anion include SbF6. - These are some examples.

[0087] In addition to those mentioned above, the non-nucleophilic anions also include, for example, the anions described in Japanese Patent Publication Nos. 2013-47211, 2021-81708, 2013-80245, 2013-80240, and 2013-33161.

[0088] From the viewpoint of low nucleophilicity and high acid strength, the non-nucleophilic anion is preferably a boron anion, a phosphate anion, a sulfonylimid anion, a gallium anion, or an antimony anion, more preferably a boron anion, a sulfonylimid anion, a gallium anion, or an antimony anion, and even more preferably a boron anion or a gallium anion. Specifically, the non-nucleophilic anion is (C6F5)4B - PF6 - (CF3CF2)3PF3 - , (FSO2)2N - , (C6F5)4Ga - Or SbF6 - (C6F5)4B is preferred. - (CF3CF2)3PF3 - , (FSO2)2N - , (C6F5)4Ga - Or SbF6 - (C6F5)4B is more preferable. -(CF3CF2)3PF3 - , or (C6F5)4Ga - That is even more preferable.

[0089] The non-nucleophilic anion mentioned above does not have to be a sulfonate anion.

[0090] The chemical structure of the salt represented by formula (1) above is, for example, 1 H-, 11 B-, 13 C-, 19 F-, or 31 It can be identified by P-nuclear magnetic resonance spectroscopy, infrared absorption spectroscopy, or elemental analysis.

[0091] Preferably, the EWG is (a1) a group having a carbonyl group (-CO-) or (a5) a cyano group, and the non-nucleophilic anion is a boron anion, a phosphate anion, a sulfonylimide anion, a gallium acid anion, or an antimony anion.

[0092] The EWG is a group having a carbonyl group (-CO-) with 1 to 10 carbon atoms, and the R 1 ~R 3 However, it is more preferable that the non-nucleophilic anion is a boron anion, a sulfonylimid anion, a gallium anion, or an antimony anion, and is identical or different to an alkyl group having 1 to 30 carbon atoms.

[0093] The EWG is a group having a carbonyl group (-CO-) with 1 to 10 carbon atoms, and the R 1 ~R 3 However, the same or different alkyl groups having 1 to 4 carbon atoms, and the non-nucleophilic anion is (C6F5)4B - PF6 - (CF3CF2)3PF3 - , (FSO2)2N - , (C6F5)4Ga - Or SbF6 - It is even more preferable that this be the case.

[0094] The EWG is one or more groups selected from groups having an acyl group, an ester group, and an amide group, and the R 3 It is particularly preferable that the group is a methyl group.

[0095] The EWG is one or more groups selected from groups having an acyl group, an ester group, and an amide group, and the R 1 , R 2 , and R 3 It is most preferable that the group is a methyl group and that n is 0.

[0096] [Salt production method] An example of a method for producing the salt represented by formula (1) is shown below.

[0097] The salt represented by formula (1) above can be produced, for example, by the following steps I and II. In the following formula, X' ― M represents a halogen ion or sulfonate anion. 1 This indicates alkali metals (lithium, sodium, potassium, etc.). EWG, R 1 , R 2 , R 3 , R 4 , X ― , n is the same as above. X' ― Examples of halogen ions in this context include Cl - , Br - , I - Examples include X'. ― A specific example of a sulfonate anion in this context is CH3SO3 - , C4H9SO3 - CF3SO3 - (TfO - ), C2F5C4H4SO3 - , C4F9SO3 - Examples include benzenesulfonate anion, p-toluenesulfonate anion, and camphorsulfonate anion, among which CF3SO3 - (TfO - ) is preferable. [ka]

[0098] (Process I) Step I is a step in which a compound represented by formula (11) (=compound (11)) and a compound represented by formula (12) (=compound (12)) are reacted to obtain a compound represented by formula (13) (=compound (13)).

[0099] Specific examples of compound (11) include 2-EWG-dialkylaniline derivatives such as compounds (C-1A) to (C-7A) listed below. [ka]

[0100] Specific examples of compound (11) include 3-EWG-dialkylaniline derivatives such as compounds (C-1B) to (C-24B) listed below. [ka]

[0101] Specific examples of compound (11) include 4-EWG-dialkylaniline derivatives such as compounds (C-1C) to (C-18C), as shown below. [ka]

[0102] Specific examples of compound (12) include p-alkoxybenzyl chloride derivatives such as compounds (D-1) to (D-9) listed below. [ka]

[0103] The molar ratio of compound (11) to compound (12) subjected to the above reaction (compound (11) / compound (12)) is, for example, 1 / 3 to 3 / 1, preferably 1 / 2 to 2 / 1.

[0104] The above reaction can be carried out in the presence of a solvent. Examples of the solvent include tetrahydrofuran, acetone, methyl ethyl ketone, acetonitrile, dimethylformamide, dimethylacetamide, and dimethyl sulfoxide. These can be used individually or in combination of two or more.

[0105] The reaction temperature is, for example, 0 to 25°C, preferably 0 to 10°C. The reaction time is, for example, 0.1 to 24 hours, preferably 0.5 to 12 hours, and more preferably 1.0 to 6 hours.

[0106] (Process II) Step II involves adding M to the compound (13) obtained through Step I. 1 This is a step in which X is reacted and salt exchange is performed to obtain the compound represented by formula (1).

[0107] Compound (13) and M to be subjected to the above reaction 1 Molar ratio of X (compound (13) / M) 1 X) is, for example, 1 / 3 to 3 / 1, preferably 1 / 2 to 2 / 1.

[0108] The above reaction can be carried out in the presence of a solvent. Examples of the solvent include tetrahydrofuran, water, ethyl acetate, dichloromethane, chloroform, methyl ethyl ketone, toluene, xylene, cyclohexane, hexane, and heptane. These can be used individually or in combination of two or more.

[0109] The reaction temperature is, for example, 0 to 25°C, preferably 0 to 10°C. The reaction time is, for example, 0.1 to 24 hours, preferably 0.1 to 12 hours, more preferably 0.1 to 8 hours.

[0110] The atmosphere for the reaction is not particularly limited as long as it does not inhibit the reaction, and may be any of the following: an air atmosphere, a nitrogen atmosphere, an argon atmosphere, etc. Furthermore, the reaction can be carried out by any method, such as a batch, semi-batch, or continuous process.

[0111] After the reaction in each step is complete, the resulting reaction product may be subjected to general separation and purification processes (e.g., precipitation, washing, filtration, etc.).

[0112] [Thermal acid generator] The present invention provides a thermal acid generator containing a salt represented by formula (1). The thermal acid generator may also contain other salts (other salts being compounds that generate acid by thermal decomposition) in addition to the salt represented by formula (1). The thermal acid generator can be manufactured by mixing the salt represented by formula (1) and, optionally, other salts.

[0113] The content of the salt represented by formula (1) in the thermal acid generator (or the proportion of the salt represented by formula (1) in 100% by weight of the total thermal acid generator) may be 50% by weight or more and less than 100% by weight, 90% by weight or more and 99.999% by weight or less, etc. The content of the salt represented by formula (1) in the thermal acid generator can be calculated, for example, from the peak area obtained using HPLC.

[0114] The thermal acid generator may contain other salts in addition to the salt represented by formula (1), but the proportion of the total salt content represented by formula (1) in the total amount of salt that generates acid by thermal decomposition contained in the thermal acid generator is, for example, 80% by weight or more, preferably 90% by weight or more, particularly preferably 95% by weight or more, most preferably 99% by weight or more, and especially preferably 99.9% by weight or more. The upper limit of the total content is 100% by weight.

[0115] The aforementioned thermal acid generator exhibits excellent heat sensitivity, and when subjected to heat treatment (for example, heating at a temperature of 50 to 180°C for 30 to 120 minutes), it rapidly decomposes and generates acid. Therefore, the thermal acid generator can be suitably used as a heat-sensitive acid generator.

[0116] [Cationic polymerization initiator] As described above, the thermal acid generator rapidly decomposes and generates acid when subjected to heat treatment (for example, heating at a temperature of 50 to 180°C for 30 to 120 minutes). When a composition containing the thermal acid generator and a cationic polymerizable compound is subjected to heat treatment, the acid generated by the heat treatment initiates cationic polymerization of the cationic polymerizable compound. Therefore, the thermal acid generator is also useful as a cationic polymerization initiator. In other words, the present invention provides a cationic polymerization initiator containing the salt represented by formula (1). For a method of producing the cationic polymerization initiator of the present invention, refer to the description of the method of producing the thermal acid generator of the present invention.

[0117] The cationic polymerization initiator may also contain other salts (compounds that generate acid upon thermal decomposition) in addition to the salt represented by formula (1).

[0118] The content of the salt represented by formula (1) in the cationic polymerization initiator (or the proportion of the salt represented by formula (1) in 100% by weight of the total thermal acid generator) may be 50% by weight or more and less than 100% by weight, 90% by weight or more and 99.999% by weight or less, etc. The content of the salt represented by formula (1) in the thermal acid generator or cationic polymerization initiator can be calculated, for example, from the peak area obtained using HPLC.

[0119] The cationic polymerization initiator may contain other salts in addition to the salt represented by formula (1), but the proportion of the total content of the salt represented by formula (1) in the total amount of salts that generate acid by thermal decomposition contained in the thermal acid generator or cationic polymerization initiator is, for example, 80% by weight or more, preferably 90% by weight or more, particularly preferably 95% by weight or more, most preferably 99% by weight or more, and especially preferably 99.9% by weight or more. The upper limit of the total content is 100% by weight.

[0120] [Curable composition] The present invention provides a curable composition comprising the salt and a cationic polymerizable compound. The salt and the cationic polymerizable compound may each be contained individually or in combination of two or more. Furthermore, the curable composition may or may not contain components other than the salt and the cationic polymerizable compound.

[0121] The salt content is, for example, 0.05 to 20 parts by weight, preferably 0.1 to 10 parts by weight, per 100 parts by weight of the cationic polymerizable compound.

[0122] The cationic polymerizable compound is a compound having one or more cationic curable groups selected from epoxy groups, oxetanyl groups, vinyl ether groups, etc. The epoxy group is a group containing a three-membered cyclic ether skeleton, and the oxetanyl group is a group containing a four-membered cyclic ether skeleton.

[0123] The number of cationic curable groups in one molecule of the cationic polymerizable compound is one or more, and is preferably 1 to 4, more preferably 2 to 4, and particularly preferably 2 to 3, in terms of excellent solubility of the thermal acid generator or the cationic polymerization initiator.

[0124] The molecular weight per cationic curable group of the aforementioned cationic polymerizable compound (for example, the equivalent amount of a cationic curable group such as epoxy equivalent or oxetane equivalent) is, for example, 50 to 500 g / eq, preferably 100 to 400 g / eq, and more preferably 100 to 300 g / eq.

[0125] Examples of the cationic polymerizable compounds include compounds having an epoxy group as a cationic curable group (= epoxy compounds), compounds having an oxetanyl group as a cationic curable group (= oxetane compounds), compounds having a vinyl ether group as a cationic curable group (= vinyl ether compounds), compounds having both an epoxy group and an oxetanyl group as cationic curable groups, compounds having both an epoxy group and a vinyl ether group as cationic curable groups, and compounds having both an oxetanyl group and a vinyl ether group as cationic curable groups.

[0126] Epoxy compounds include, for example, epoxy-modified siloxane compounds, alicyclic epoxy compounds (alicyclic epoxy resins), aromatic epoxy compounds (aromatic epoxy resins), and aliphatic epoxy compounds (aliphatic epoxy resins).

[0127] Examples of the epoxy-modified siloxane compound include epoxy-modified silicones and epoxy-modified polyorganosylsesquioxanes.

[0128] Examples of the alicyclic epoxy compound include, but are not particularly limited to, known or conventional compounds having one or more alicyclic rings and one or more epoxy groups in the molecule, such as the following compounds. (1) Compounds having an alicyclic epoxy group (= an epoxy group composed of two adjacent carbon atoms and an oxygen atom that constitute an alicyclic ring within the molecule) (2) Compounds having an alicyclic ring and a glycidyl ether group

[0129] Examples of compounds having the alicyclic epoxy group include 3',4'-epoxycyclohexylmethyl(3,4-epoxy)cyclohexanecarboxylate, 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1-methylhexanecarboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-3-methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexanecarboxylate, and 3,4-epoxy Examples include C-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexanecarboxylate, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexanemethioxane, bis(3,4-epoxycyclohexylmethyl)adipate, 3,4-epoxy-6-methylcyclohexylcarboxylate, methylenebis(3,4-epoxycyclohexane), dicyclopentadiene diepoxide, and ethylenebis(3,4-epoxycyclohexanecarboxylate).

[0130] Examples of compounds having an alicyclic ring and a glycidyl ether group include glycidyl ethers of alicyclic alcohols (especially alicyclic polyhydric alcohols). More specifically, examples include hydrogenated compounds of bisphenol A type epoxy compounds such as 2,2-bis[4-(2,3-epoxypropoxy)cyclohexyl]propane and 2,2-bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl]propane (hydrogenated bisphenol A type epoxy compounds); bis[o,o-(2,3-epoxypropoxy)cyclohexyl]methane, bis[o,p-(2,3-epoxypropoxy)cyclohexyl]methane, bis[p,p-(2,3-epoxypropoxy)cyclohexyl] Examples include hydrogenated compounds of bisphenol F type epoxy compounds such as sil]methane and bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl]methane (hydrogenated bisphenol F type epoxy compounds); hydrogenated biphenol type epoxy compounds; hydrogenated phenol novolac type epoxy compounds; hydrogenated cresol novolac type epoxy compounds; hydrogenated cresol novolac type epoxy compounds of bisphenol A; hydrogenated naphthalene type epoxy compounds; and hydrogenated trisphenolmethane type epoxy compounds.

[0131] Examples of the aromatic epoxy compounds include epibis-type glycidyl ether epoxy resins obtained by the condensation reaction of bisphenols [e.g., bisphenol A, bisphenol F, bisphenol S, fluorenebisphenol, etc.] with epihalohydrins; high molecular weight epibis-type glycidyl ether epoxy resins obtained by further addition reactions of these epibis-type glycidyl ether epoxy resins with the bisphenols; and phenols [e.g., phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol]. Examples include novolac alkyl-type glycidyl ether epoxy resins obtained by condensing polyhydric alcohols obtained by condensing polyhydric alcohols [e.g., formaldehyde, acetaldehyde, benzaldehyde, hydroxybenzaldehyde, salicylaldehyde, etc.] with epihalohydrins, and epoxy resins in which two phenol skeletons are bonded to the 9th position of a fluorene ring, and glycidyl groups are bonded directly or via alkylene oxy groups to the oxygen atoms obtained by removing hydrogen atoms from the hydroxyl groups of these phenol skeletons.

[0132] Examples of the aliphatic epoxy compounds include glycidyl ethers of alcohols (where q is a natural number) that do not have a q-valent cyclic structure; glycidyl esters of monovalent or polyvalent carboxylic acids [e.g., acetic acid, propionic acid, butyric acid, stearic acid, adipic acid, sebacic acid, maleic acid, itaconic acid, etc.]; epoxides of oils and fats having double bonds, such as epoxides of linseed oil, epoxides of soybean oil, and epoxides of castor oil; and epoxides of polyolefins (including polyalkadienes), such as epoxides of polybutadiene. Examples of alcohols that do not have a cyclic structure with a q-valent value include monohydric alcohols such as methanol, ethanol, 1-propyl alcohol, isopropyl alcohol, and 1-butanol; dihydric alcohols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol; and polyhydric alcohols with a trivalent or higher value such as glycerin, diglycerin, erythritol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, and sorbitol. Furthermore, the alcohol with a q-valent value may be polyether polyol, polyester polyol, polycarbonate polyol, polyolefin polyol, etc.

[0133] Other examples of the aforementioned epoxy compounds include bisphenolalkyl-substituted cyclohexane skeleton-containing epoxy resins (including, for example, those disclosed in International Publication No. 2021 / 024616); epoxidized polybutadiene resins (including, for example, those disclosed in International Publication No. 2022 / 080372); biphenyl skeleton-containing epoxy resins (including, for example, those disclosed in International Publication No. 2022 / 080372); resins having at least one of a structural unit having a chemical structure in which a phenolic hydroxyl group is protected by an acid-dissociable group and a structural unit having a chemical structure in which a carboxyl group is protected by an acid-dissociable group, and a structural unit having an epoxy group (including, for example, those disclosed in Japanese Patent Application Publication No. 2022-100724); and epoxy compounds disclosed in International Publication No. 2022 / 080372, International Publication No. 2022 / 009846, and Japanese Patent Application Publication No. 2023-175317.

[0134] Examples of the oxetane compounds include 3,3-bis(vinyloxymethyl)oxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, 3-ethyl-3-(hydroxymethyl)oxetane, 3-ethyl-3-[(phenoxy)methyl]oxetane, 3-ethyl-3-(hexyloxymethyl)oxetane, 3-ethyl-3-(chloromethyl)oxetane, 3,3-bis(chloromethyl)oxetane, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, and bi Examples include s([1-ethyl(3-oxetanyl)]methyl) ether, 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]bicyclohexyl, 4,4'-bis[3-ethyl-(3-oxetanyl)methoxymethyl]biphenyl, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]cyclohexane, 1,4-bis([(3-ethyl-3-oxetanyl)methoxy]methyl)benzene, 3-ethyl-3([(3-ethyloxetan-3-yl)methoxy]methyl)oxetane, xylylenebisoxetane, etc.

[0135] Examples of the vinyl ether compounds include aryl vinyl ethers such as phenyl vinyl ether; alkyl vinyl ethers such as n-butyl vinyl ether and n-octyl vinyl ether; cycloalkyl vinyl ethers such as cyclohexyl vinyl ether; vinyl ethers having a hydroxyl group such as 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, and 2-hydroxybutyl vinyl ether; and polyfunctional vinyl ethers such as hydroquinone divinyl ether, 1,4-butanediol divinyl ether, cyclohexane divinyl ether, cyclohexane dimethanol divinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, and triethylene glycol divinyl ether.

[0136] The cationic polymerizable compound preferably contains at least one alicyclic epoxy compound having one or more (preferably 1 to 4) alicyclic epoxy groups (particularly a polyfunctional alicyclic epoxy compound having two or more (preferably 2 to 4) alicyclic epoxy groups).

[0137] The cationic polymerizable compound may be a combination of the alicyclic epoxy compound and a glycidyl ether type epoxy compound having one or more (preferably 1 to 4) glycidyl ether groups and / or an oxetane compound having one or more (preferably 1 to 4) oxetanyl groups. When used in combination, the blending ratio [alicyclic epoxy compound / (glycidyl ether type epoxy compound and oxetane compound); weight ratio] is, for example, 95 / 5 to 5 / 95, preferably 95 / 5 to 30 / 70, more preferably 95 / 5 to 40 / 60, even more preferably 95 / 5 to 60 / 40, particularly preferably 90 / 10 to 65 / 35, and most preferably 85 / 15 to 65 / 35.

[0138] The curable composition may contain one or more other components as needed, in addition to the components mentioned above. Examples of other components include sensitizers, sensitizing aids, antioxidants, stabilizers, surfactants, solvents, rheology control agents, leveling agents, silane coupling agents, fillers, conductive particles, polymerization inhibitors, light stabilizers, plasticizers, defoamers, foaming agents, UV absorbers, tackifiers, curing retarders, ion adsorbents, pigments, dyes, phosphors, mold release agents, antistatic agents, flame retardants, radical curable compounds, polyimide resins, polyamide resins, phenoxy resins, poly(meth)acrylate resins, polyurethane resins, polyurea resins, polyester resins, polyvinyl butyral resins, SBS, SEBS, etc. The content of these components (total amount if two or more are included) is, for example, 50% by weight or less, preferably 10% by weight or less, and particularly preferably 5% by weight or less, of the total amount of the curable composition (100% by weight). The content of these components is, for example, 0.05% by weight or more, preferably 0.1% by weight or more, of the total amount (100% by weight) of the curable composition.

[0139] The curable composition can be produced by uniformly mixing the thermal acid generator or the cationic polymerization initiator, the cationic polymerizable compound, and other components added as needed, using commonly known mixing equipment such as a self-rotating stirring and defoaming apparatus, a homogenizer, a planetary mixer, a three-roll mill, or a bead mill. The components may be mixed simultaneously or sequentially.

[0140] The thermoacid generator or cationic polymerization initiator contained in the curable composition preferably exhibits curability at low temperatures, such as 70°C or lower (preferably 50-70°C).

[0141] The curable composition can preferably be cured at a low temperature, such as 70°C or lower (preferably 50-70°C).

[0142] The uses of the curable composition are not particularly limited, and examples include paints, coatings, inks, positive resists, negative resists, resist films, liquid resists, photosensitive materials, adhesives, molding materials, casting materials, putties, glass fiber impregnating agents, sealing materials, encapsulants, materials for stereolithography, optical materials, and raw materials for electronic materials. The optical or electronic materials include lenses such as eyeglass lenses, imaging lenses for (digital) cameras, light beam focusing lenses, light diffusion lenses, and microlenses; encapsulants for LEDs; optical adhesives and bonding materials for optical transmission; prisms; filters; diffraction gratings; cover glass for various display devices such as liquid crystal displays and organic EL displays; encapsulants for various display devices (display elements) such as liquid crystal displays and organic EL displays; anisotropic conductive films; connectors capable of joining electronic components equipped with fine-pitch electrodes; adhesive films for circuit connections; curable resin compositions that can be blackened; and adhesive compositions.

[0143] The following are specific examples of combinations of the composition of the curable composition and preferred applications.

[0144] (Curable composition suitable for anisotropic conductive connecting materials) The curable composition may contain a thermal acid generator containing the thermal acid generator or a cationic polymerization initiator containing the cationic polymerization initiator, a binder composition containing the cationic polymerizable compound and a film-forming component, and conductive particles. Such a composition is useful, for example, as an anisotropic conductive connecting material such as an anisotropic conductive film.

[0145] The cationic polymerizable compound preferably contains an alicyclic epoxy compound and an oxetane compound. The mixing ratio of the alicyclic epoxy compound and the oxetane compound is preferably 25:75 to 60:40 by mass, more preferably 45:55 to 60:40, and particularly preferably 50:50 to 55:45. The amount of the cationic polymerizable compound in the binder composition is preferably 10 to 80% by weight, more preferably 20 to 60% by weight. Within this range, a binder composition with a higher curing rate can be obtained.

[0146] The aforementioned film-forming component is a component used to form a film from the composition and is a component that has film-forming ability. Examples of such film-forming components include phenoxy resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, urethane resin, butadiene resin, polyimide resin, polyamide resin, and polyolefin resin.

[0147] The conductive particles can be appropriately selected from those used in known or conventional anisotropic conductive materials. Examples include metal particles such as nickel, cobalt, silver, copper, gold, and palladium, alloy particles such as solder, and metal-coated resin particles. Two or more of these may be used in combination.

[0148] The anisotropic conductive film can be manufactured by dissolving conductive particles and a thermal acid generator containing the thermal acid generator or a cationic polymerization initiator containing the cationic polymerization initiator in the binder composition in an organic solvent such as toluene to form a paint, and then forming the paint into a film using a known film-forming method.

[0149] For further details on each of the above terms (cationic polymerizable compound, film-forming component, binder composition, conductive particles, anisotropic conductive film, anisotropic conductive connecting material, etc.), the blending ratio of each component in the composition, the method of manufacturing the composition, etc., please refer to the descriptions in Japanese Patent Publication No. 2017-152354, Japanese Patent Publication No. 2021-68842, etc.

[0150] (A curable composition suitable for adhesive films used in circuit connections) The curable composition comprises a first adhesive layer containing conductive particles, a cured product of a photocurable resin component, and a first thermosetting resin component, and a second adhesive layer provided on the first adhesive layer and containing a second thermosetting resin component, wherein the first thermosetting resin component and the second thermosetting resin component contain a cationic polymerizable compound and a thermoacid generator containing the thermoacid generator or a cationic polymerization initiator containing the cationic polymerization initiator, and the photocurable resin component may contain a radical polymerizable compound. Such a composition is useful, for example, as an adhesive film for circuit connections.

[0151] The conductive particles may be metal particles, conductive carbon particles, or coated conductive particles, and insulating coated conductive particles comprising an insulating layer that covers the surface of the particles and contains an insulating material such as resin.

[0152] Examples of the photocurable resin component include compounds that have radical polymerizable groups that react with radicals such as (meth)acryloyl groups, vinyl groups, allyl groups, styryl groups, alkenyl groups, alkenylene groups, and maleimide groups, and that undergo radical polymerization upon irradiation with light (e.g., ultraviolet light).

[0153] The cationic polymerizable compound may be at least one selected from the group consisting of oxetane compounds and alicyclic epoxy compounds.

[0154] For further details on each of the aforementioned terms (conductive particles, photocurable resin component, first thermosetting resin component, first adhesive layer, second thermosetting resin component, second adhesive layer, cationic polymerizable compound, etc.), the proportions of each component in the composition, the method of manufacturing the composition, etc., please also refer to the description in International Publication No. 2022 / 009846.

[0155] (Curable composition suitable for encapsulating image display devices) The curable composition may contain a thermoacid generator containing the thermoacid generator or a cationic polymerization initiator containing the cationic polymerization initiator, a cationic polymerizable compound containing a bisphenol alkyl-substituted cyclohexane skeleton-containing epoxy resin, and optionally a silane coupling agent. Such a composition is useful, for example, as a encapsulant for an image display device.

[0156] The bisphenolalkyl-substituted cyclohexane skeleton-containing epoxy resin, for example, has multiple bisphenolalkyl-substituted cyclohexane skeletons and multiple epoxy groups (polyfunctional (including difunctional) epoxy resin). Preferably, the bisphenolalkyl-substituted cyclohexane skeleton-containing epoxy resin has a molecular chain containing multiple bisphenolalkyl-substituted cyclohexane skeletons and epoxy groups bonded to both ends of the molecular chain (difunctional epoxy resin).

[0157] Furthermore, the curable composition may also contain a thermoacid generator containing the thermoacid generator or a cationic polymerization initiator containing the cationic polymerization initiator, an oxetane compound, an epoxidized polybutadiene resin, a biphenyl skeleton-containing epoxy resin, and a tackifying resin. Such a composition is also useful, for example, as a encapsulant for an image display device.

[0158] The oxetane compound has an oxetanyl group as a cationic polymerizable group.

[0159] The epoxidized polybutadiene resin is a polyfunctional epoxy resin having a polybutadiene skeleton and a plurality of epoxy groups. Note that polyfunctional epoxy resins include bifunctional epoxy resins (the same applies hereinafter). The polybutadiene skeleton is a molecular chain (main chain) composed of polymers of 1,3-butadiene. The polybutadiene skeleton contains the molecular structure of 1,2-polybutadiene and has side chains branching from the molecular chain. The epoxy groups are located on the side chains of the polybutadiene skeleton. The epoxy groups are introduced by oxidizing the vinyl groups of 1,2-polybutadiene contained in the polybutadiene skeleton.

[0160] The biphenyl skeleton-containing epoxy resin is, for example, a polyfunctional epoxy resin having multiple biphenyl skeletons and multiple epoxy groups. Preferably, the biphenyl skeleton-containing epoxy resin is a bifunctional epoxy resin having molecular chains containing multiple biphenyl skeletons and epoxy groups bonded to both ends of the molecular chains.

[0161] The tackifying resin can impart tackiness to the encapsulant while maintaining the dielectric constant of the curable composition. The tackifying resin preferably contains a ring skeleton (aliphatic ring and / or aromatic ring) and does not contain epoxy groups. Examples of the tackifying resin include petroleum resins, terpene resins, phenolic resins, and rosin resins, with petroleum resins, terpene resins, etc., being preferred.

[0162] For further details on each of the above terms (cationic polymerizable compounds, silane coupling agents, oxetane compounds, epoxidized polybutadiene resins, biphenyl skeleton-containing epoxy resins, tackifying resins, image display device encapsulants, etc.), the proportions of each component in the composition, and the method of manufacturing the composition, please also refer to International Publication No. 2021 / 024616 and International Publication No. 2022 / 080372.

[0163] (Curable composition suitable for adhesives) The curable composition may contain a thermal acid generator containing the thermal acid generator or a cationic polymerization initiator containing the cationic polymerization initiator, a (meth)acrylate compound, an organic peroxide, an epoxy compound, and optionally a coupling agent, an antioxidant, an inorganic filler, etc. Such a composition is useful, for example, as an adhesive.

[0164] The (meth)acrylate compound is a compound having one or more (meth)acryloyl groups. Examples of the (meth)acrylate compound include monofunctional (meth)acrylates having one (meth)acryloyl group, and polyfunctional (meth)acrylates having two or more (meth)acryloyl groups.

[0165] The aforementioned organic peroxide is a compound that generates radicals upon heating and is primarily a compound that promotes the high molecular weight of the (meth)acrylate compound. Examples of the aforementioned organic peroxide include those having an -OO- bond, such as peroxyketals, hydroperoxides, dialkylperoxides, diacylperoxides, peroxydicarbonates, and peroxyesters.

[0166] Examples of the epoxy compounds include alicyclic epoxy compounds, epoxy compounds having aliphatic groups, and epoxy compounds having aromatic rings.

[0167] For further details on each of the above terms ((meth)acrylate compounds, organic peroxides, epoxy compounds, coupling agents, antioxidants, inorganic fillers, adhesives, etc.), the proportions of each component in the composition, and the method for manufacturing the composition, please refer to the description in Japanese Patent Application Publication No. 2024-107759.

[0168] (A curing composition suitable for black adhesives) The curable composition may contain a thermoacid generator containing the thermoacid generator or a cationic polymerization initiator containing the cationic polymerization initiator, a curable resin containing a radical polymerizable compound, a photoradical polymerization initiator, a leuco dye, a cationic polymerizable compound (e.g., an epoxy compound), and optionally a chain transfer agent, a leveling agent, etc. Such a composition is useful, for example, as a black adhesive.

[0169] The radical polymerizable compound is not particularly limited as long as it is a compound having a radical polymerizable group in its molecule, but compounds having an ethylenically unsaturated double bond as the radical polymerizable group are preferred, and (meth)acrylic compounds are more preferred.

[0170] Examples of the aforementioned photoradical polymerization initiators include benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, and thioxanthone compounds.

[0171] Examples of the leuco dyes mentioned above include 2'-anilino-6'-(N-ethyl-N-isopentylamino)-3'-methylspiro[phthalide-3,9'-xanthene], 2'-anilino-6'-(N,N-dipentan-1-ylamino)-3'-methyl-3H-spiro[isobenzofuran-1,9'-xanthene]-3-one, 2'-anilino-6'-(dibutylamino)-3'-methylspiro[phthalide-3,9'-xanthene], and 2'-anilino-6'-[N-ethyl-N-(4-tolyl)amino]-3'-methyl-3H-spiro[isobenzofuran-1,9'-xanthene]-3-one.

[0172] For further details on each of the above terms (curable resin containing radical polymerizable compounds, photoradical polymerization initiator, leuco dye, epoxy compound, chain transfer agent, leveling agent, etc.), the blending ratio of each component in the composition, the method of producing the composition, etc., please also refer to the description in Japanese Patent Application Publication No. 2023-175317.

[0173] (A curable composition suitable for microlens formation) The curable composition may contain a resin having at least one of a structural unit having a chemical structure in which a phenolic hydroxyl group is protected by an acid-dissociable group and a structural unit having a chemical structure in which a carboxyl group is protected by an acid-dissociable group, and a structural unit having an epoxy group; a thermal acid generator containing the thermal acid generator or a cationic polymerization initiator containing the cationic polymerization initiator; and a solvent. Such a composition is preferably used to form microlenses.

[0174] The resin preferably comprises a copolymer of at least one of a structural unit having a chemical structure in which a phenolic hydroxyl group is protected by an acid-dissociable group and a structural unit having a chemical structure in which a carboxyl group is protected by an acid-dissociable group, and a structural unit having an epoxy group.

[0175] For further details on each of the above terms (resins, solvents, microlenses, etc., having at least one of a constituent unit having a chemical structure in which a phenolic hydroxyl group is protected by an acid-dissociable group and a constituent unit having a chemical structure in which a carboxyl group is protected by an acid-dissociable group, and a constituent unit having an epoxy group), the blending ratio of each component in the composition, the method for producing the composition, etc., please also refer to the description in Japanese Patent Application Publication No. 2022-100724.

[0176] [Cured product] The present invention provides a cured product of the curable composition.

[0177] The cured product is obtained by curing the curable composition.

[0178] The curable composition can be cured by heat treatment. The heating temperature is, for example, 50 to 180°C, and it is possible to cure it even at low temperatures such as 50 to 70°C. The heating time is, for example, 0.5 to 2 hours.

[0179] The configurations and combinations thereof described above are merely examples, and additions, omissions, substitutions, and modifications to the configurations are permitted as appropriate, without departing from the spirit of the present invention. [Examples]

[0180] The present invention will be described more specifically below with reference to examples, but the present invention is not limited to these examples.

[0181] [Preparation of the salt represented by formula (1) above] Synthesis Example 1-1 (Process I) 2.87 g of sodium iodide was dissolved in 20.7 mL of methyl ethyl ketone, and 3.00 g of 4-methoxybenzyl chloride was added dropwise thereto, followed by stirring for 3 hours at room temperature. Next, 3.70 g of ethyl 4-(dimethylamino)benzoate was added and stirred for 30 minutes. Thereafter, 4.23 g of potassium hexafluorophosphate and 20.0 mL of water were added and stirred for 3 hours to complete the reaction. After removing the aqueous layer, 10.0 mL of ethyl acetate was added, and the organic layer was washed once with 20.0 mL of ion-exchanged water. Thereafter, the organic layer was desolvated to obtain 5.06 g of a salt (1-1) of a cation represented by the following formula X-1-1 and a hexafluorophosphate anion (PF6 - ).

[0182]

Chemical formula

[0183] Synthesis Example 1-2[[ID=!15]] A salt (1-2) of 4.70 g of a cation represented by the following formula X-1-2 and a hexafluorophosphate anion (PF6 - ) was obtained in the same manner as in Synthesis Example 1-1, except that ethyl 4-(dimethylamino)benzoate was changed to 4'-dimethylaminoacetophenone.

[0184] [[ID=!21]] [[ID=!22]]

Chemical formula

[0185] Synthesis Example 1-3 [[ID=!32]](Step I) 4.79 g of sodium iodide was dissolved in 29.9 mL of methyl ethyl ketone, and 5.00 g of 4-methoxybenzyl chloride was added dropwise thereto, followed by stirring for 3 hours at room temperature. The filtrate obtained by subjecting the reaction solution to filtration was added dropwise with 5.72 g of methyl 3-(dimethylamino)benzoate and stirred for 3 hours. The solid obtained by subjecting the reaction solution to filtration was washed 5 times with 5.0 mL of methyl ethyl ketone to obtain 10.2 g of a salt of a cation represented by the following formula X-1-3 and an iodide anion (I - ).

[0186] Note: Some of the chemical formula tags ( - ) are likely to be actual chemical structure diagrams or specific chemical formula notations in a non-standard text format. Since they don't have a direct equivalent in text-only English translation, they are left as they are. Also, the "

化

Chemical formula

[0187] Synthesis Example 1-4 Except for changing sodium tetrakis(pentafluorophenyl)borate to sodium tetrakis(pentafluorophenyl)gallate, the same procedure as in Synthesis Example 1-3 was used to obtain the cation represented by formula X-1-3 and the tetrakis(pentafluorophenyl)gallate anion (Ga(C6F5)4 - 2.14g of salt (1-4) was obtained from the mixture.

[0188] Synthesis Example 2-1 (Process I) 50.0 g of N,N-dimethylaniline, 64.6 g of 4-methoxybenzyl chloride, and 16.9 g of acetonitrile were mixed and heated to 50°C. The temperature of this reaction solution (50°C) was maintained for 5 hours to complete the reaction.

[0189] 250 g of acetone was added to the reaction solution, and the temperature was lowered to below 10°C and stirred for 1 hour. The reaction solution was then filtered, and the resulting solid was separated to obtain 81.3 g of N-(4-methoxybenzyl)-N,N-dimethylanilinium chloride.

[0190] (Process II) 50.0 g of N-(4-methoxybenzyl)-N,N-dimethylanilinium chloride obtained in Project I was dissolved in 200 g of ion-exchanged water, and 250 g of dichloromethane and 71.3 g of sodium tetrakis(pentafluorophenyl)borate were sequentially added.

[0191] After the addition was complete, the mixture was stirred at room temperature for 1 hour to complete the reaction. Then, the aqueous layer was removed, and the organic layer was washed three times with 300 g of ion-exchanged water. Thereafter, the organic layer was desolvated to obtain 84.2 g of a salt (2-1) of a cation represented by the following formula X-2-1 and a tetrakis(pentafluorophenyl)borate anion (B(C6F5)4 - ).

[0192] [Chemical formula]

[0193] The salts obtained in the above synthesis examples are summarized in Table 5 below.

[0194] [ [Table 5]

[0195] [Preparation of curable composition] Into a beaker, each component was charged according to the formulation shown in Table 6 below (unit: part by weight), a stirrer was added, and a dissolution treatment was carried out by stirring at 20 °C and 100 rpm to obtain a curable composition. As the cationic curable compound, 3’,4’-epoxycyclohexylmethyl (3,4-epoxy)cyclohexanecarboxylate (trade name “Celloxide 2021P”, manufactured by Daicel Corporation) was used.

[0196] [Curability evaluation] For the prepared curable composition, differential thermal analysis (reaction start temperature, exothermic peak temperature) was carried out using a thermal analyzer (DSC5100, manufactured by Seiko Instruments Inc.), and the curability was evaluated according to the following criteria. [Evaluation criteria] ○ (Good): Reaction start temperature is 70 °C or lower △ (Acceptable): Reaction start temperature exceeds 70°C

[0197] The reaction initiation temperature is the temperature at which acid is generated from the thermal acid generator and cationic polymerization begins. The lower the reaction initiation temperature, the higher the low-temperature curing ability.

[0198] (Thermal stability evaluation) The prepared curable composition was placed in a 30 mL screw-cap tube and left to stand in a 25°C constant temperature bath. The viscosity of the sample at 25°C was measured at regular intervals. A Toki Sangyo Co., Ltd. E-type viscometer "TV-100EH" was used for viscosity measurement. The time elapsed when the viscosity doubled compared to before storage was defined as the pot life. Thermal stability was evaluated according to the following criteria. <Evaluation Criteria> ○ (Good): Pot life is 6 hours or longer △(Acceptable): Pot life is less than 6 hours

[0199] The results obtained are shown in Table 6.

[0200] [Table 6]

[0201] As shown in Table 6, the curable compositions in Examples 1 to 3 exhibited improved low-temperature curability, with a lower reaction initiation temperature in DSC measurements compared to that of the curable composition in Comparative Example 1. Furthermore, the curable compositions in Examples 1 to 3 also demonstrated good thermal stability.

[0202] The present invention includes the following variations. [Note 1] The salt represented by formula (1) above. [In formula (1), EWG indicates an electron-withdrawing group. R 1 and R 2 These are identical or different, indicating an alkyl group. R 1 and R 2 These may be bonded to each other, forming a ring with the nitrogen atom to which they are bonded. R 3 This indicates an alkyl group. R 4 This represents an alkyl group or an alkoxy group. R 3 and R 4 They may be bonded to each other, forming a ring with each atom in formula (1) to which they are bonded, in which case R 4 It may also be an ether group (-O-), n represents an integer from 0 to 4. X - This represents a non-nucleophilic anion. [Note 2] The salt described in Note 1, wherein EWG is a group having a carbonyl group. [Note 3] The salt according to Note 1 or 2, wherein the EWG is one or more groups selected from groups having an acyl group, an ester group, and an amide group. [Note 4] The above R 3 A salt described in any one of the appendices 1 to 3, wherein the group is a methyl group. [Note 5] The EWG is one or more groups selected from groups having an acyl group, an ester group, and an amide group, and the R 3 A salt described in any one of the appendices 1 to 4, wherein the group is a methyl group. [Note 6] A thermal acid generator or cationic polymerization initiator containing a salt described in any one of Notes 1 to 5. [Note 7] A curable composition comprising a salt described in any one of Notes 1 to 5 and a cationic polymerizable compound. [Note 8] The curable composition according to Note 7, wherein the cationic polymerizable compound is a compound having one or more cationic curable groups selected from the group consisting of epoxy groups, oxetanyl groups, and vinyl ether groups. [Note 9] A cured product of the curable composition described in Note 7 or 8.

Claims

1. The salt represented by the following formula (1). 【Chemistry 1】 [In formula (1), EWG indicates an electron-withdrawing group. R １ and R ２ These are identical or different, indicating an alkyl group. R １ and R ２ These may be bonded to each other, forming a ring with the nitrogen atom to which they are bonded. R ３ This indicates an alkyl group. R ４ This represents an alkyl group or an alkoxy group. R ３ and R ４ may be joined to each other to form a ring together with each atom in formula (1) to which they are attached, in which case R ４ may be an ether group (—O—), n represents an integer from 0 to 4. X - This represents a non-nucleophilic anion.

2. The salt according to claim 1, wherein the EWG is a group having a carbonyl group.

3. The salt according to claim 1, wherein the EWG is one or more groups selected from an acyl group, a group having an ester group, and a group having an amide group.

4. The aforementioned R ３ The salt according to claim 1, wherein is a methyl group.

5. The EWG is one or more groups selected from groups having an acyl group, an ester group, and an amide group, and the R ３ The salt according to claim 1, wherein is a methyl group.

6. A thermal acid generator or cationic polymerization initiator comprising the salt described in any one of claims 1 to 5.

7. A curable composition comprising the salt described in any one of claims 1 to 5 and a cationic polymerizable compound.

8. The curable composition according to claim 7, wherein the cationic polymerizable compound is a compound having one or more cationic curable groups selected from the group consisting of epoxy groups, oxetanyl groups, and vinyl ether groups.

9. A cured product of the curable composition according to claim 7.

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