JP6397784B2 - Thermosetting resin composition and thermosetting sheet - Google Patents

Description

  The present invention relates to a thermosetting resin composition and a thermosetting sheet.

In recent years, the cost reduction of electronic parts or electronic substrate materials has been remarkable, and member design using inexpensive resin as a material has been promoted. Inevitably, the heat resistance of the member becomes inferior, and the demand for a component bonding agent that cures at a lower temperature is increasing. In addition, there is a strong demand for shortening the process tact time, and there is a demand for curing in a shorter time.
The use of cationic polymerization is widely known as a technique for performing epoxy resin-based thermosetting at low temperatures.

For example, Patent Document 1 discloses that a sulfonium salt using antimony hexafluoride, phosphorus hexafluoride or the like as a counter anion is useful as a cation curing catalyst for an epoxy resin. In particular, sulfonium salts using antimony hexafluoride are commercially available as low-temperature curing catalysts.
Patent Document 2 discloses a cation curing catalyst using a tetrakis (pentafluorophenyl) borate anion having an activity equivalent to that of antimony hexafluoride.
Although these cationic curing catalysts have low-temperature curing activity, there is a problem that the storage stability when blended with an epoxy resin is extremely insufficient as it is.

Usually, onium salt-type thermal cation polymerization catalysts are designed to increase the cation dissociation in order to increase the low-temperature curing activity, but this leads to spontaneous dissociation in the polar field, which is considered to be storage stability. It becomes difficult to achieve both.
In this regard, as a technique for promoting cation dissociation by another method, a technique for generating an acid by a radical is disclosed. For example, Non-Patent Document 1 describes an onium salt dissociation and a polymerization method of cyclohexene oxide (CHO) using a radical having the following structure as a starting species. In such a technique, it seems that the polymerization promoting effect of the oxirane compound can be obtained by using radical species together.
However, such a technique does not have sufficient low-temperature curing activity and has room for improvement.

Patent Documents 3 to 5 disclose that an ammonium salt compound can be contained in the thermosetting resin composition for the purpose of accelerating curing. However, these techniques cannot achieve both low-temperature curability and storage stability.
Therefore, the present condition is that provision of a thermosetting resin composition and a thermosetting sheet that can be cured at a low temperature in a short time and can ensure storage stability before curing is required.

Japanese Patent Laid-Open No. 2-1470 JP 9-176112 A JP 2013-91687 A JP 2011-132416 A JP 2013-185013 A

Aysen Onen and Yusuf Yagci Macromolecules 2001, 34, 7608-7612

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, an object of the present invention is to provide a thermosetting resin composition and a thermosetting sheet that can be cured at a low temperature in a short time and can be effectively cured while ensuring storage stability before curing. .

Means for solving the problems are as follows. That is,
<1> A thermosetting resin composition comprising a cationic curing component, an ammonium salt represented by the following general formula (1), and a radical generator.
However, the general formula (1), ^{R 1} and ^{R 2} each independently represents an alkyl group having 1 to 2 carbon atoms. R ³ represents any one of a hydrogen atom, an alkyl group, an alkoxycarbonyl group, and an aryloxycarbonyl group. Y represents any of an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonylmethyl group, an alkoxycarbonylmethyl group, an arylcarbonyl group, an arylcarbonylmethyl group, an N-alkylcarbamoyl group, and an N-phenylcarbamoyl group. Z ⁻ represents SbF ₆ ⁻ , B (C ₆ F ₅ ) ₄ ⁻ , C (CF ₃ SO ₂ ) ₃ ⁻ , and [P (R ⁸ ) _a (F) _6−a ] ⁻ (wherein R ⁸ Each independently represents an alkyl group in which at least a part of hydrogen atoms may be substituted with fluorine, and a represents an integer of 0 to 5.
<2> the general formula (1) Z ^{- _{is, SbF 6 -, B (C}} 6 F 5) 4 -, and _{C (CF 3 SO 2) 3} - of according to <1> is either It is a thermosetting resin composition.
<3> The thermosetting resin composition according to any one of <1> to <2>, wherein the radical generator is an organic peroxide.
<4> The thermosetting resin composition according to any one of <1> to <3>, further including a phenoxy resin.
<5> A thermosetting sheet comprising the thermosetting resin composition according to any one of <1> to <4>.

  According to the present invention, the conventional problems can be solved, the object can be achieved, the curing can be performed at a low temperature and in a short time, and the curing can be effectively cured while ensuring the storage stability before curing. Resin composition and thermosetting sheet can be provided.

(Thermosetting resin composition)
The thermosetting resin composition of the present invention contains at least a cationic curing component, an ammonium salt having a specific structure, and a radical generator, preferably contains a film-forming resin, and further contains other resins as necessary. Contains ingredients.
The thermosetting resin composition of the present invention that satisfies the above requirements is excellent in both low-temperature short-time curability and storage stability.

The inventor made a thermosetting sheet by containing an ammonium salt having the structure described in Non-Patent Document 1, and the ammonium salt described in Non-Patent Document 1 has insufficient low-temperature curing activity. It was found that (see the results of Comparative Example 2 containing Comparative Compound Example 2 (ammonium salt corresponding to the above EADA in Non-Patent Document 1) in Examples described later).
Therefore, the present inventor conducted various experiments, and as a result of repeated research on the components contained in the thermosetting resin composition, the specific ammonium salt and a radical generator that generates radicals by heat are contained in combination. It has been found that by activating a specific ammonium salt as a cationic curing agent, a thermosetting resin composition excellent in low-temperature and short-time curability can be obtained while ensuring storage stability.
The reason why the compound represented by the general formula (1) defined in the present invention is excellent in low-temperature and short-time curability with respect to the compound described in Non-Patent Document 1 is not clear, but the radical generated from the radical generator is The generation rate of the cation radical of the amine generated after addition to the ammonium salt of the invention is higher than that of the structure described in Non-Patent Document 1, and as a result of rapid proton release thereafter, the cation curing can be performed at a lower temperature. I think it will progress.

<Cationic curing component>
The cationic curing component is not particularly limited as long as it is a component that is cured by the action of a specific ammonium salt as a cationic curing agent, and can be appropriately selected according to the purpose. For example, an epoxy compound, a vinyl ether compound , Oxetane compounds, and cyclic ether compounds. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the epoxy compound include bisphenol type epoxy resin, polyglycidyl ether, polyglycidyl ester, aromatic epoxy compound, alicyclic epoxy compound, novolac type epoxy compound, glycidylamine type epoxy compound, glycidyl ester type epoxy compound, biphenyl. Examples thereof include diglycidyl ether, triglycidyl isocyanurate, polyglycidyl methacrylate, and a copolymer of glycidyl methacrylate and a vinyl monomer copolymerizable with the glycidyl methacrylate.

  Examples of the alicyclic epoxy compound include a cyclohexene oxide-containing compound and a cyclopentene oxide-containing compound.

  Examples of the vinyl ether compound include alkyl vinyl ether compounds, alkenyl vinyl ether compounds, alkynyl vinyl ether compounds, and aryl vinyl ether compounds.

  Examples of the oxetane compound include oxetane alcohols, aliphatic oxetane compounds, and aromatic oxetane compounds.

  There is no restriction | limiting in particular as content of the said cationic hardening component in the said thermosetting resin composition, Although it can select suitably according to the objective, It is 10 with respect to the non volatile matter of the said thermosetting resin composition. % By mass to 98% by mass is preferable, and 20% by mass to 90% by mass is more preferable.

<Ammonium salt represented by the general formula (1)>
In this invention, the ammonium salt compound represented by following General formula (1) is contained as a cationic hardening | curing agent.
However, the general formula (1), ^{R 1} and ^{R 2} each independently represents an alkyl group having 1 to 2 carbon atoms. R ³ represents any one of a hydrogen atom, an alkyl group, an alkoxycarbonyl group, and an aryloxycarbonyl group. Y represents any of an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonylmethyl group, an alkoxycarbonylmethyl group, an arylcarbonyl group, an arylcarbonylmethyl group, an N-alkylcarbamoyl group, and an N-phenylcarbamoyl group. Z ⁻ represents SbF ₆ ⁻ , B (C ₆ F ₅ ) ₄ ⁻ , C (CF ₃ SO ₂ ) ₃ ⁻ , and [P (R ⁸ ) _a (F) _6−a ] ⁻ (wherein R ⁸ Each independently represents an alkyl group in which at least a part of hydrogen atoms may be substituted with fluorine, and a represents an integer of 0 to 5.

Examples of the alkyl group having 1 to ² carbon atoms of R ¹ and R ² include a methyl group and an ethyl group.
Examples of the alkyl group for R ³ include an alkyl group having 1 to 4 carbon atoms, and examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and an isobutyl group.
Examples of the alkoxycarbonyl group for R ³ include an alkoxycarbonyl group having 1 to 8 carbon atoms, and specific examples include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, and an n-butoxycarbonyl group. .
Examples of the aryloxycarbonyl group for R ³ include a substituted or unsubstituted phenoxycarbonyl group, a triroxycarbonyl group, a xylyloxycarbonyl group, and a naphthoxycarbonyl group. Examples of the substituent include a hydroxyl group and an alkoxy group. Group, carboxyl group and the like.

As said alkylcarbonyl group of Y, a C2-C8 alkylcarbonyl group is mentioned, for example.
Examples of the alkoxycarbonyl group for Y include an alkoxycarbonyl group having 2 to 8 carbon atoms.
Examples of the alkylcarbonylmethyl group for Y include an alkylcarbonylmethyl group having 3 to 10 carbon atoms.
Examples of the alkoxycarbonylmethyl group for Y include an alkoxycarbonylmethyl group having 3 to 10 carbon atoms.
Examples of the arylcarbonyl group for Y include substituted and unsubstituted phenylcarbonyl groups and naphthylcarbonyl groups. Examples of the substituent include an alkyl group, an alkoxy group, a hydroxyl group, and a carboxyl group.
Examples of the arylcarbonylmethyl group for Y include a substituted or unsubstituted phenylcarbonylmethyl group and a naphthylcarbonylmethyl group. Examples of the substituent include an alkyl group, an alkoxy group, a hydroxyl group, and a carboxyl group. .
Examples of the N-alkylcarbamoyl group for Y include N-alkylcarbamoyl groups having 2 to 10 carbon atoms.
Examples of the N-phenylcarbamoyl group for Y include an N-phenylcarbamoyl group having 7 to 12 carbon atoms. The phenyl group in the N-phenylcarbamoyl group may have a substituent.

Examples of the specific structure of the cation moiety of the ammonium salt represented by the general formula (1) include the following structures.

X ⁻ in the general formula (1) is an anion, specifically, SbF ₆ ⁻ , B (C ₆ F ₅ ) ₄ ⁻ , C (CF ₃ SO ₂ ) ₃ ⁻ , and [P (R ^8). _{) a (F) 6-a} ] - ( wherein, ^{R 8} are each independently at least a portion of the hydrogen atom is an alkyl group which may be substituted with fluorine, a is an integer of 0 to 5 It is shown.)

Examples of the alkyl group for R ⁸ include an alkyl group having 1 to 10 carbon atoms, and a perfluoroalkyl group having 1 to 4 carbon atoms is particularly preferable. Specific examples include a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and a nonafluorobutyl group.
Among these, SbF ₆ ⁻ , B (C ₆ F ₅ ) ₄ ⁻ , and C (CF ₃ SO ₂ ) ₃ ⁻ are preferable in that lower temperature curability can be obtained.

  There is no restriction | limiting in particular as content of the ammonium salt represented by the said General formula (1) in the said thermosetting resin composition, Although it can select suitably according to the objective, The said thermosetting resin composition The non-volatile content is preferably 0.5% by mass to 20% by mass, and more preferably 2% by mass to 15% by mass.

<Radical generator>
The radical generator is not particularly limited as long as it generates radicals by heat and can be appropriately selected according to the purpose. Examples thereof include azo compounds, organic and inorganic peroxides. . Among these, an organic peroxide is preferable in terms of easy storage stability.
Examples of the organic peroxide include diacyl peroxide, peroxydicarbonate, peroxyester, peroxyketal, dialkyl peroxide, hydroperoxide, and silyl peroxide. Of these, diacyl peroxide, peroxyester, peroxydicarbonate, and peroxyketal are preferable in that low temperature activity is easily obtained.
A plurality of these compounds that generate radicals by heat can be used in combination.

  There is no restriction | limiting in particular as content of the said radical generator in the said thermosetting resin composition, Although it can select suitably according to the objective, It is 0 with respect to the non volatile matter of the said thermosetting resin composition. .3% by mass to 20% by mass is preferable, and 0.5% by mass to 15% by mass is more preferable.

<Film forming resin>
The film-forming resin is not particularly limited and can be appropriately selected depending on the purpose. For example, polyacrylic resin, phenoxy resin, polyester resin, polyurethane resin, polyester urethane resin, polyvinyl butyral resin, polyvinyl formal resin, Examples thereof include polyamide resin and polyimide resin. These may be used individually by 1 type and may use 2 or more types together. Among these, a phenoxy resin is particularly preferable from the viewpoint of film formability and processability.

Examples of the phenoxy resin include those obtained by reacting a bifunctional phenol with epichlorohydrin to increase the molecular weight, or a resin obtained by polyaddition of a bifunctional epoxy resin and a bifunctional phenol.
Examples of the bifunctional epoxy resin used include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol S type epoxy resin, biphenyl diglycidyl ether, and methyl-substituted biphenyl diglycidyl ether. It is done.
Examples of the bifunctional phenols include hydroquinones, bisphenol A, bisphenol F, bisphenol AD, bisphenol S, bisphenol fluorene, methyl-substituted bisphenol fluorene, bisphenols such as dihydroxybiphenyl and methyl-substituted dihydroxybiphenyl.

  There is no restriction | limiting in particular as content of the said film formation resin in the said thermosetting resin composition, Although it can select suitably according to the objective, It is 10 with respect to the non volatile matter of the said thermosetting resin composition. % By mass to 90% by mass is preferable, 20% by mass to 80% by mass is more preferable, and 30% by mass to 60% by mass is particularly preferable.

<Other ingredients>
The other components are not particularly limited and may be appropriately selected depending on the purpose. For example, thixotropic agents, fillers, leveling agents, antioxidants, polymerization inhibitors, light stabilizers, colorants, conductive agents Examples include property imparting agents and adhesion imparting agents.
In particular, it is preferable to contain a polymerization inhibitor or an antioxidant because it functions as a radical trap during storage of the thermosetting resin composition of the present invention and may improve storage stability.

The polymerization inhibitor or the antioxidant is not particularly limited as long as it is a polymerization inhibitor for radical polymerization, and examples thereof include a phenol polymerization inhibitor, an amine polymerization inhibitor, and a spin trap agent.
Examples of the phenol polymerization inhibitor include hydroquinone, 2-t-butylhydroquinone, 2-t-butyl-4-methoxyphenol, 2,3-di-t-butyl-4-methoxyphenol, and p-methoxyphenol. 2,6-di-t-butyl-p-cresol, 4-allyl-2-methoxyphenol, 4-t-butylcatechol, 4,4′thiobis (6-t-butyl-m-cresol), 2, 5-di-t-butylhydroquinone, 2,5-di-t-amylhydroquinone, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- (3,5-di-t-butyl- 4-hydroxyphenyl) propionate, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol) 4,4′-thiobis (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 3,9-bis [1,1- Dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, 1,1 , 3-Tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4- Hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis (4′-hydroxy) -3'-butylphenyl) butyryl Quad] glycol ester, 1,3,5-tris (3 ′, 5′-di-t-butyl-4′-hydroxybenzyl) -2-triazine-2,4,6- (1H, 3H, 5H) trione , Α-tocophenol and the like.

Examples of the amine polymerization inhibitor include 2-phenylindole, N, N′-diphenylethylenediamine, N, N′-disalisilalpropylenediamine, and phenothiazine.
Examples of the spin trapping agent include diphenylpicrylhydrazyl radical, 2,2,6,6-tetramethyl-1-piperidinyloxy radical, 1,1,3,3-tetramethylisoindole-2- An oxy radical etc. are mentioned.

Among these, a phenol polymerization inhibitor is preferable from the viewpoint of functioning in an acidic environment.
The content of the polymerization inhibitor or the antioxidant in the thermosetting resin composition is preferably 0.1 mol% to 3 mol% with respect to the compound of the general formula (1).

(Thermosetting sheet)
The said thermosetting sheet | seat of this invention contains the said thermosetting resin composition of this invention, and also contains another component as needed.

The thermosetting sheet is formed, for example, by forming a thermosetting adhesive layer made of the thermosetting resin composition on a base film (peeling base). Examples of the base film include a polyethylene terephthalate film and a polyimide film.
From the viewpoints of storage properties, handling properties during use, and the like, the thermosetting sheet is obtained by applying the thermosetting resin composition to a base film that is peel-treated with silicone or the like as necessary for a polyethylene terephthalate film, a polyimide film, or the like. It is preferable that the thermosetting adhesive layer made of is formed with an average thickness of 10 μm to 50 μm.

  The thermosetting resin composition and the thermosetting sheet can be preferably applied to the field of electronic components. In particular, the thermosetting sheet adheres and fixes a terminal portion of a flexible printed wiring board and a reinforcing sheet having a thickness of 50 μm to 2 mm such as polyethylene terephthalate, polyimide, glass epoxy, stainless steel, and aluminum for lining the same. Therefore, the terminal portion of the flexible printed wiring board and the reinforcing sheet can be bonded and fixed with the thermosetting material of the thermosetting adhesive layer excluding the base film of the thermosetting sheet of the present invention. Thus, a reinforced flexible printed wiring board is obtained.

When using a thermosetting sheet as an adhesive sheet, it is preferable that a thermoplastic resin is contained in the composition. As the thermoplastic resin used, the polyacryl resin, phenoxy resin, polyester resin, polyurethane resin, polyester urethane resin, polyvinyl butyral resin, polyvinyl formal resin, polyamide resin, polyimide resin described in the section of <Film-forming resin> And epoxy resin. Among these, as described above, the phenoxy resin is preferably contained from the viewpoints of film formability, compatibility, and heat resistance.
When used as an adhesive sheet for bonding metals, it is preferable that a silane coupling agent is contained in the composition. There is no restriction | limiting in particular as a kind of silane coupling agent, According to the objective, it can select suitably, For example, an epoxy-type silane coupling agent, an acrylic-type silane coupling agent, a thiol-type silane coupling agent, an amine-type silane A coupling agent etc. are mentioned.
When used as an adhesive sheet that imparts conductivity, it is preferable to contain conductive particles in the composition. The type of the conductive particles is not particularly limited and can be appropriately selected according to the purpose. For example, metal particles such as gold, silver, copper, tin, and nickel, metal particles, or inorganic particles such as silica are subjected to metal plating or Examples thereof include particles coated with metal by vapor deposition and the like, and particles coated with metal by metal plating or vapor deposition on resin particles. The shape of the particle is not particularly limited, and examples thereof include a spherical shape, a needle shape, an irregular shape, and a shape having fine protrusions.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Synthesis Example p-1)
<Synthesis of Compound p-1>
A 200 mL three-necked flask equipped with a stirrer, a condenser tube, and a nitrogen inlet tube was charged with 5.00 g (0.0364 mol) of 3- (dimethylamino) phenol, 50 mL of dehydrated acetonitrile and 4.42 g (0.0437 mol) of triethylamine every minute. While introducing 100 mL of nitrogen gas, 3.14 g (0.0400 mol) of acetyl chloride was added dropwise thereto over 20 minutes, followed by further stirring for 2 hours. After completion of the stirring, filtration was performed to remove the precipitated hydrochloride of triethylamine, the filtrate was concentrated under reduced pressure, then separated with ethyl acetate and pure water, and the ethyl acetate phase was washed with water three times. Thereafter, the ethyl acetate phase was concentrated under reduced pressure, and further dried under reduced pressure for 24 hours to obtain 5.64 g (yield: 86.4%) of a liquid compound p-1 represented by the following structural formula (p-1). Obtained.

(Synthesis Example p-2)
<Synthesis of Compound p-2>
A 200 mL three-necked flask equipped with a stirrer, a condenser tube, and a nitrogen inlet tube was charged with 5.00 g (0.0364 mol) of 3- (dimethylamino) phenol, 50 mL of dehydrated acetonitrile, and 4.42 g (0.0437 mol) of triethylamine. After cooling to 100 mL of nitrogen gas per minute, 3.78 g (0.0400 mol) of methyl chloroformate was added dropwise over 20 minutes, followed by further stirring for 4 hours. After completion of the stirring, filtration was performed to remove the precipitated hydrochloride of triethylamine, the filtrate was concentrated under reduced pressure, then separated with ethyl acetate and pure water, and the ethyl acetate phase was washed with water three times. Thereafter, the ethyl acetate phase was concentrated under reduced pressure, and further dried under reduced pressure for 24 hours to obtain 6.37 g (yield: 89.7%) of a liquid compound p-2 represented by the following structural formula (p-2). Obtained.

(Synthesis Example p-3)
<Synthesis of Compound p-3>
In a 200 mL three-necked flask equipped with a stirrer, a condenser tube, and a nitrogen inlet tube, 5.00 g (0.0364 mol) of 3- (dimethylamino) phenol, 30 mL of dehydrated acetonitrile and 6.03 g (0.0437 mol) of potassium carbonate were placed. The temperature was raised to ° C. and stirred for 30 minutes. While introducing 100 mL of nitrogen gas per minute, 4.34 g (0.0400 mol) of methyl chloroacetate was added dropwise over 10 minutes, and the mixture was further stirred for 4 hours. After completion of the stirring, the mixture was filtered, and the filtrate was concentrated under reduced pressure, then separated with ethyl acetate and pure water, and the ethyl acetate phase was washed with water three times. Thereafter, the ethyl acetate phase was concentrated under reduced pressure, and further dried under reduced pressure for 24 hours to obtain 6.66 g (yield 87.5%) of a liquid product of compound p-3 represented by the following structural formula (p-3). Obtained.

(Synthesis Example p-4)
<Synthesis of Compound p-4>
In a 200 mL three-necked flask equipped with a stirrer, a condenser tube, and a nitrogen inlet tube, 5.00 g (0.0364 mol) of 3- (dimethylamino) phenol, 30 mL of dehydrated acetonitrile and 6.03 g (0.0437 mol) of potassium carbonate were placed. The temperature was raised to ° C. and stirred for 30 minutes. While introducing 100 mL of nitrogen gas per minute, 5.42 g (0.0400 mol) of 1-chloropinacholine was added dropwise over 10 minutes, and then the mixture was further stirred for 4 hours. After the stirring, filtration was performed, and the residue was washed with acetonitrile. The filtrate was concentrated under reduced pressure, then separated with ethyl acetate and pure water, and the ethyl acetate phase was further washed with water three times. Thereafter, the ethyl acetate phase was concentrated under reduced pressure, and further dried under reduced pressure for 24 hours, whereby 7.16 g (yield: 83.2%) of a red crystal of compound p-4 represented by the following structural formula (p-4) Got.

(Synthesis Example p-5)
<Synthesis of Compound p-5>
In a 200 mL three-necked flask equipped with a stirrer, a condenser tube, and a nitrogen inlet tube, 5.00 g (0.0364 mol) of 3- (dimethylamino) phenol, 40 mL of methyl ethyl ketone, and 0.05 g of triethylamine were added and heated to 60 ° C. While introducing 100 mL of nitrogen gas per minute, 3.78 g (0.0437 mol) of phenyl isocyanate was added dropwise over 30 minutes, followed by further stirring for 2 hours.
After cooling, the mixture was cooled, concentrated under reduced pressure, washed with toluene, and dried under reduced pressure for 24 hours. Thus, 7.30 g (yield) of the compound p-5 represented by the following structural formula (p-5) 78.2%).

(Synthesis Example 1-A)
<Synthesis of ammonium salt 1-A>
In a 100 mL three-necked flask equipped with a stirrer, 3.000 g (0.0167 mol) of compound p-1 synthesized in Synthesis Example p-1 and 10 g of acetonitrile were added and stirred at room temperature to obtain a uniform solution. Thereto, 3.87 g (0.0200 mol) of ethyl 2- (bromomethyl) acrylate was added dropwise over 10 minutes, and the mixture was further stirred for 24 hours. After stirring, concentration under reduced pressure was performed, followed by liquid separation with 50 g of ethyl acetate / 100 g of distilled water, and the aqueous phase was taken out.
Thereafter, the aqueous phase was transferred to a 1 L flask, and 351.7 g (0.0167 mol) of a 3% by mass aqueous solution of sodium salt of tetrakis (pentafluorophenyl) borate was slowly added over 10 minutes while stirring at room temperature. . Red crystals precipitated immediately after the addition.
After the addition, the mixture was further stirred for 1 hour, and then filtered, washed with water, and dried under reduced pressure. 6.86 g of a red crystal of compound 1-A of the ammonium salt represented by the structural formula (1-A) (yield 42.3) %).

(Synthesis Example 2-A)
<Synthesis of Ammonium Salt 2-A>
A compound represented by the structural formula (2-A) in the same manner as in Synthesis Example 1-A, except that Compound p-1 in Synthesis Example 1-A was replaced by 3.26 g (0.0167 mol) of Compound p-2. This gave 6.44 g (yield 39.1%) of red crystals of the ammonium salt compound 2-A.

(Synthesis Example 3-A)
<Synthesis of ammonium salt 3-A>
A compound represented by the structural formula (3-A) in the same manner as in Synthesis Example 1-A, except that Compound p-1 in Synthesis Example 1-A was replaced by 3.49 g (0.0167 mol) of Compound p-3. As a result, 8.61 g (yield 51.5%) of red crystals of the ammonium salt compound 3-A was obtained.

(Synthesis Example 4-A)
<Synthesis of Ammonium Salt 4-A>
A compound represented by the structural formula (4-A) in the same manner as in Synthesis Example 1-A, except that Compound p-1 in Synthesis Example 1-A was replaced with 3.95 g (0.0167 mol) of Compound p-4. As a result, 10.5 g (yield 61.2%) of red crystals of the ammonium salt compound 4-A was obtained.

(Synthesis Example 5-A)
<Synthesis of Ammonium Salt 5-A>
The compound p-1 in synthesis example 1-A was replaced with 4.28 g (0.0167 mol) of compound p-5, and acetonitrile was further replaced with a mixed solvent of 10 g of acetonitrile and 10 g of acetone. In the same manner as A, 5.18 g (yield 29.3%) of reddish brown crystals of the compound 5-A of the ammonium salt represented by the structural formula (5-A) were obtained.

(Synthesis Example 1-B)
<Synthesis of ammonium salt 1-B>
The structural formula is the same as in Synthesis Example 1-A, except that tetrakis (pentafluorophenyl) borate in Synthesis Example 1-A is replaced with 144.1 g (0.0167 mol) of a 3% by weight aqueous solution of sodium hexafluoroantimonate. 3.31 g (yield 37.5%) of red crystals of the compound 1-B of the ammonium salt represented by (1-B) was obtained.

(Synthesis Example 6-A)
<Synthesis of ammonium salt 6-A>
The same procedure as in Synthesis Example 1-A was conducted, except that ethyl 2- (bromomethyl) acrylate in Synthesis Example 1-A was replaced with 2.7 g (0.0200 mol) of 3-bromo-2-methyl-1-propene. Then, 9.52 g (yield 62.4%) of red crystals of the ammonium salt compound 6-A represented by the structural formula (6-A) was obtained.

(Synthesis Example 7-A)
<Synthesis of ammonium salt 7-A>
In the same manner as in Synthesis Example 1-A, except that ethyl 2- (bromomethyl) acrylate in Synthesis Example 1-A was replaced with 2.42 g (0.0200 mol) of allyl bromide, Structural Formula (7-A) 9.93 g (yield 66.1%) of red crystals of the represented ammonium salt compound 7-A were obtained.

(Comparative Compound Example 1 (Synthesis Example 8-A))
<Synthesis of Ammonium Salt 8-A>
In the synthesis example 1-A, the structural formula (8-A) was obtained in the same manner as in the synthesis example 1-A, except that the compound p-1 was replaced with 2.02 g (0.0167 mol) of N, N-dimethylaniline. As a result, 10.39 g (yield: 68.1%) of white crystals of ammonium salt 8-A represented by

(Comparative Compound Example 2 (Synthesis Example 8-B))
<Synthesis of ammonium salt 8-B>
Synthesis Example 8-A, except that in Synthesis Example 8-A, the sodium salt 3 mass% aqueous solution of tetrakis (pentafluorophenyl) borate was replaced with 144.1 g (0.0167 mol) of a 3 mass% sodium hexafluoroantimonate aqueous solution. In the same manner, 4.80 g (yield 61.1%) of white crystals of ammonium salt 8-B represented by the structural formula (8-B) were obtained.

(Comparative Compound Example 3 (Synthesis Example 9-A))
<Synthesis of Ammonium Salt 9-A>
In Synthesis Example 8-A, the procedure was the same as that of Synthesis Example 8-A, except that 2- (bromomethyl) ethyl acrylate was replaced with 2.7 g (0.0200 mol) of 3-bromo-2-methyl-1-propene. As a result, 9.73 g (yield 68.1%) of white crystals of ammonium salt 9-A was obtained.

(Comparative Compound Example 4 (Synthesis Example 10-A))
<Synthesis of ammonium salt 10-A>
In Synthesis Example 8-A, white of ammonium salt 10-A was obtained in the same manner as in Synthesis Example 8-A, except that ethyl 2- (bromomethyl) acrylate was replaced with 2.42 g (0.0200 mol) of allyl bromide. 10.0 g (yield 71.5%) of crystals were obtained.

(Examples 1-10 and Comparative Examples 1-17)
Thermosetting resin compositions were prepared according to the formulations shown in Table 1-1 to Table 1-5.
The prepared thermosetting resin composition is coated on release PET (polyethylene terephthalate) that has been subjected to silicone-based mold release treatment, and is dried in a hot-air circulating oven set at 60 ° C. for 5 minutes, thereby thermosetting with an average thickness of 15 μm. Sheet was prepared.

The numerical value in Table 1-1 to Table 1-5 is the compounding quantity except a solvent part, and a unit is a mass part.
In addition, each material in Table 1-1 to Table 1-5 is as follows.
YP-70: manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., bisphenol A / bisphenol F copolymerized phenoxy resin FX-316: manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. A type epoxy resin YL983U: Mitsubishi Chemical Corporation, bisphenol F type epoxy resin Parroyl L: NOF Corporation, dilauroyl peroxide

  When blended, YP-70 and FX-316 used a 45 mass% solid content solution of methyl ethyl ketone, and YL980 and YL983U used a stock solution. Parroyl L was a 30% solids solution of toluene. As each ammonium salt, a 30% by mass solid content solution of methyl ethyl ketone was used.

(Low-temperature short-time curability and storage stability evaluation of the thermosetting sheets of Examples 1 to 10 and Comparative Examples 1 to 17)
The differential scanning calorimeter DSC6200 manufactured by SII Nanotechnology Co., Ltd. was used to determine the low-temperature short-time curability and storage stability of the produced thermosetting sheets of Examples 1 to 10 and Comparative Examples 1 to 17 (average thickness 15 μm). Was used to evaluate.

<Evaluation of low-temperature short-time curability>
Each thermosetting sheet (1.5 mg) was put in an aluminum container having a diameter of 5 mm for DSC6200, covered with a clamp, and an evaluation sample was produced. After each sample was pressed against the heater plate for 5 seconds, differential scanning calorimetry was performed, and the reaction rate was calculated from the heat value and the heat value before pressing. The temperature of the heater plate was 120 ° C and 130 ° C.
It is well known in the art that the exothermic behavior by differential scanning calorimetry reflects the curing reaction behavior of the epoxy resin. Therefore, it can be said that the ratio of the calorific value before and after heating by the heater plate reflects the reaction rate of the epoxy resin in the thermosetting sheet.
From a practical viewpoint, the low-temperature short-time curability is approximately 65% at 130 ° C.
The results are shown in Tables 2-1 to 2-5.
-Measurement conditions-
Temperature increase rate 10 ° C / min (25 ° C to 300 ° C)
N ₂ gas 100mL / min
Sample weight about 1.5mg

<Evaluation of storage stability>
Storage stability was evaluated by calculating the rate of decrease from the calorific value change in differential scanning calorimetry before and after standing for 2 weeks in a dark environment at 25 ° C./65% RH. As described above, since the exothermic behavior by differential scanning calorimetry reflects the curing reaction behavior of the epoxy resin, the amount of change in the exothermic amount before and after leaving reflects the amount of progress of the epoxy reaction during leaving. It can be said that the smaller the change in calorific value before and after being left, the higher the storage stability. From a practical viewpoint, specifically, the function as a thermosetting sheet can be maintained by suppressing the decrease to 10% or less. The evaluation results of storage stability are shown in Tables 2-1 to 2-5.
-Measurement conditions-
Temperature increase rate 10 ° C / min (25 ° C to 300 ° C)
N ₂ gas 100mL / min
Sample weight about 5mg

From the results of Tables 2-1 to 2-5, the ammonium salt compound having a specific structure represented by the general formula (1) of the present invention has a remarkable low-temperature short-time curability by containing a radical generator. It can be expressed (from Examples 1 to 8 and Comparative Examples 5 to 12).
On the other hand, ammonium salt compounds other than the general formula (1), although containing a radical generator, had good storage stability but did not show significant low-temperature curability (Comparative Examples 1 to 4 and Comparative Example) 13 to 16).
Therefore, in order to achieve both low-temperature curability and storage stability, it is effective to contain an ammonium salt compound having a specific structure represented by the general formula (1) of the present invention and a radical generator. I understood.

  Since the thermosetting resin composition of the present invention can be cured at a low temperature in a short time and can ensure storage stability before curing, it can be suitably used as an adhesive for joining electronic components.

Claims (5)

A thermosetting resin composition comprising a cationic curing component, an ammonium salt represented by the following general formula (1), and a radical generator.
However, the general formula (1), ^{R 1} and ^{R 2} each independently represents an alkyl group having 1 to 2 carbon atoms. R ³ represents any one of a hydrogen atom, an alkyl group, an alkoxycarbonyl group, and an aryloxycarbonyl group. Y represents any of an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonylmethyl group, an alkoxycarbonylmethyl group, an arylcarbonyl group, an arylcarbonylmethyl group, an N-alkylcarbamoyl group, and an N-phenylcarbamoyl group. Z ⁻ represents SbF ₆ ⁻ , B (C ₆ F ₅ ) ₄ ⁻ , C (CF ₃ SO ₂ ) ₃ ⁻ , and [P (R ⁸ ) _a (F) _6−a ] ⁻ (wherein R ⁸ Each independently represents an alkyl group in which at least a part of hydrogen atoms may be substituted with fluorine, and a represents an integer of 0 to 5. _{2. The} thermosetting resin according to claim 1, wherein Z ^{− in the} general formula (1) is any one of SbF ₆ ⁻ , B (C ₆ F ₅ ) ₄ ⁻ , and C (CF ₃ SO ₂ ) ₃ ^—. Composition.   The thermosetting resin composition according to claim 1, wherein the radical generator is an organic peroxide.   Furthermore, the thermosetting resin composition in any one of Claim 1 to 3 containing a phenoxy resin. A thermosetting sheet comprising the thermosetting resin composition according to claim 1.