JP7013643B2 - Thermosetting resin composition - Google Patents

Description

The present invention relates to a thermosetting resin composition.

Conventionally, as a matrix resin for composite materials, an epoxy resin having high elongation and excellent adhesion to a reinforcing material has been widely used. However, in the advanced technology fields such as aviation, space, and defense industries where the adoption of composite materials is being promoted, it is necessary to mold parts with better mechanical strength, heat resistance, workability, and dimensional accuracy at low cost. Is required, and the use of bismaleimide resin as a matrix resin is being studied.

However, in order to use the bismaleimide resin, it is necessary to treat it at a high temperature of 200 ° C. or higher for a long time as a curing condition, and there is a drawback that productivity and processability are poor. For example, Patent Document 1 proposes a polymer (cured product) of a mixture of a bismaleimide compound and a benzoxazine compound. However, in curing such a polybenzoxazine-modified bismaleimide resin composition, a heating temperature of 200 ° C. or higher is required, which makes it difficult to put into practical use.

On the other hand, the use of peroxide has been proposed for low-temperature curing, but since the peroxide is deactivated by air oxidation, a cured film of stable quality cannot be obtained, or it is cured in a nitrogen atmosphere. Satisfactory results have not yet been obtained, such as the need to make it necessary.

Japanese Unexamined Patent Publication No. 2012-97207

An object of the present invention is to provide a thermosetting resin composition capable of forming a cured product having excellent heat resistance and being able to be cured at a low temperature.

［式（１）中、Ｒ^１及びＱは各々独立に、置換又は非置換の炭素数１～１００の脂肪族基、置換又は非置換の芳香族基、置換又は非置換のヘテロ芳香族基、或いは、置換又は非置換のケイ素数１～１００のシロキサン部位を示し、ｎは１～１００の整数を示す。］

［式（２）中、Ｒ^２は二価の有機基を示す。］

［式（３）中、Ｒ^３～Ｒ^７は各々独立に一価の有機基を示す。］
［２］上記（Ａ）マレイミド化合物が、上記一般式（１）で表されるマレイミド化合物を少なくとも含む、上記［１］に記載の熱硬化性樹脂組成物。
［３］上記（Ｃ）ホスホニウム塩の含有量が、上記（Ａ）マレイミド化合物及び上記（Ｂ）エポキシ基含有化合物の総量１００質量部に対して０．１～５．０質量部である、上記［１］又は［２］に記載の熱硬化性樹脂組成物。
［４］上記（Ｂ）エポキシ基含有化合物のエポキシ当量が１５０～３００である、上記［１］～［３］のいずれかに記載の熱硬化性樹脂組成物。
［５］上記一般式（３）中、上記Ｒ^３～Ｒ^６は各々独立に、置換又は非置換の炭素数１～１０の脂肪族基、置換又は非置換の芳香族基を示す、上記［１］～［４］のいずれかに記載の熱硬化性樹脂組成物。
［６］上記一般式（３）中、上記Ｒ^３～Ｒ^６は各々独立に、フェニル基、メチル基、エチル基、ｎ－プロピル基又はｎ－ブチル基を示す、上記［１］～［５］のいずれかに記載の熱硬化性樹脂組成物。
［７］上記（Ｃ）ホスホニウム塩における上記アニオン種が、フタル酸、１，２－シクロヘキサンジカルボン酸又はラウリン酸である、上記［１］～［６］のいずれかに記載の熱硬化性樹脂組成物。
［８］上記（Ｃ）ホスホニウム塩が、テトラフェニルホスホニウム－フタル酸、テトラブチルホスホニウム－１，２－シクロヘキサンジカルボン酸、及び、テトラブチルホスホニウム－ラウリン酸からなる群より選択される１種以上を含む、上記［１］～［７］のいずれかに記載の熱硬化性樹脂組成物。 As a result of studying to solve the above-mentioned problems, the present inventors have found that the following problems can be solved by the present invention.
That is, the present invention provides the following inventions.
[1] (A) The following general formula (2) other than the maleimide compound having at least two imide bonds represented by the following general formula (1) and the maleimide compound represented by the following general formula (1). One or more maleimide compounds selected from the group consisting of maleimide compounds having at least two maleimide groups represented, (B) an epoxy group-containing compound having at least two epoxy groups in one molecule, and (C). A thermosetting resin composition containing a phosphonium salt having one or more carboxy groups in the anion species represented by the following general formula (3).

[In the formula (1), ^R1 and Q are independently substituted or unsubstituted aliphatic groups having 1 to 100 carbon atoms, substituted or unsubstituted aromatic groups, substituted or unsubstituted heteroaromatic groups, respectively. Alternatively, it indicates a substituted or unsubstituted siloxane moiety having a silicon number of 1 to 100, and n represents an integer of 1 to 100. ]

[In formula (2), R ² represents a divalent organic group. ]

[In the formula (3), R ³ to R ⁷ each independently represent a monovalent organic group. ]
[2] The thermosetting resin composition according to the above [1], wherein the above (A) maleimide compound contains at least the maleimide compound represented by the above general formula (1).
[3] The content of the (C) phosphonium salt is 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the total amount of the (A) maleimide compound and the (B) epoxy group-containing compound. The thermosetting resin composition according to [1] or [2].
[4] The thermosetting resin composition according to any one of the above [1] to [3], wherein the epoxy equivalent of the (B) epoxy group-containing compound is 150 to 300.
[5] In the above general formula (3), the above R ³ to R ⁶ independently represent a substituted or unsubstituted aliphatic group having 1 to 10 carbon atoms and a substituted or unsubstituted aromatic group, respectively. 1] The thermosetting resin composition according to any one of [4].
[6] In the above general formula (3), the above R ³ to R ⁶ independently represent a phenyl group, a methyl group, an ethyl group, an n-propyl group or an n-butyl group, respectively, and the above [1] to [5]. ] The thermosetting resin composition according to any one of.
[7] The thermosetting resin according to any one of the above [1] to [6], wherein the anion species in the (C) phosphonium salt is phthalic acid, 1,2- cyclohexanedicarboxylic acid or lauric acid. Composition.
[8] The (C) phosphonium salt is one or more selected from the group consisting of tetraphenylphosphonium-phthalic acid, tetrabutylphosphonium-1,2- cyclohexanedicarboxylic acid, and tetrabutylphosphonium-lauric acid. The thermosetting resin composition according to any one of the above [1] to [7], which comprises.

According to the thermosetting resin composition of the present invention, by using the above-mentioned specific (A) maleimide compound, a cured product having excellent heat resistance can be formed, and the above-mentioned specific (B) epoxy group can be formed. By using the contained compound and the specific (C) phosphonium salt in combination with the (A) maleimide compound, excellent low-temperature curability can be obtained while maintaining the above-mentioned effect of improving heat resistance. In particular, by using not only the (C) phosphonium salt but also the (B) epoxy group-containing compound in combination, the low-temperature curability of the thermosetting resin composition can be dramatically improved.

According to the present invention, it is possible to provide a thermosetting resin composition capable of forming a cured product having excellent heat resistance and being able to be cured at a low temperature. Since the thermosetting resin composition of the present invention can form a cured product having excellent heat resistance and can be cured at a low temperature, it is expected to dramatically improve its molding processability.

Hereinafter, the present invention will be described in detail according to the preferred embodiment thereof.

The thermosetting resin composition of the present embodiment contains (A) a maleimide compound having at least two maleimide groups in one molecule as a maleimide component, and (B) an epoxy group having at least two epoxy groups in one molecule. It contains a compound and (C) phosphonium salt as a curing accelerator.

The (A) maleimide compound used in the present embodiment is a maleimide compound having at least two imide bonds in one molecule represented by the following general formula (1) (hereinafter referred to as “(A-1) maleimide compound”). , And a maleimide compound having at least two maleimide groups in one molecule represented by the following general formula (2) other than the maleimide compound represented by the following general formula (1) (hereinafter, “(A-2)). It is one or more maleimide compounds selected from the group consisting of "maleimide compounds").

In the above general formula (1), R ¹ is a substituted or unsubstituted aliphatic group having 1 to 100 carbon atoms, a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, or a substituted or unsubstituted. It shows a siloxane moiety having an unsubstituted silicon number of 1 to 100, but if the molecular chain is too short, the flexibility is poor, and if the molecular chain is too long, the solvent solubility is poor. From the viewpoint of balancing the two, the number of carbon atoms or the number of silicon of R ¹ is preferably 10 to 80, more preferably 20 to 50.

In the above general formula (1), Q is a substituted or unsubstituted aliphatic group having 1 to 100 carbon atoms, a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, or a substituted or unsubstituted. Although the substituted siloxane moiety having a silicon number of 1 to 100 is shown, the carbon number or the silicon number of Q is preferably 1 to 30 from the viewpoint of solvent solubility.

In the above general formula (1), n represents an integer of 1 to 100, but may be an integer of 1 to 10.

In the above general formula (2), R ² represents a divalent organic group, but from the viewpoint of heat resistance of the cured product, it is a divalent organic group having an aromatic group and / or an aliphatic hydrocarbon group. Is preferable.

The maleimide compound (A-1) represented by the general formula (1) is described in Designer Moleculars, Inc. Although commercially available from the company, the acid compound (d) is present in the amine-terminated polyimide obtained by dehydrating and condensing the liquid diamine compound (b) and the acid dianhydride (c) in the low polar solvent (a). Below, maleic anhydride (e) can be synthesized by dehydration condensation.

(A-1) Examples of the low polar solvent (a) used for synthesizing the maleimide compound include aromatic solvents such as toluene, xylene and mesitylen, saturated hydrocarbon solvents such as hexane and cyclohexane, and crude oil distillation. Examples thereof include a obtained petroleum-based solvent, but from the viewpoint of cost and ease of desolubilization, it is preferable to use toluene or xylene.

(A-1) Examples of the liquid amine compound (b) used in synthesizing the maleimide compound include 1,10-diaminodecane; 1,12-diaminododecane; dimerdiamine; 1,2-diamino-2-methyl. Propane; 1,2-diaminocyclohexane; 1,2-diaminopropane; 1,3-diaminopropane; 1,4-diaminobutane; 1,5-diaminopentane; 1,7-diaminoheptane; 1,8-diaminomentane 1,8-diaminooctane; 1,9-diaminononane; 3,3'-diamino-N-methyldipropylamine;diaminomaleonitrile;1,3-diaminopentane;9,10-diaminophenanthrene;4,4'-Diaminooctafluorobiphenyl; 3,5-diaminobenzoic acid; 3,7-diamino-2-methoxyfluorene; 4,4'-diaminobenzophenone;3,4-diaminobenzophenone;3,4-diaminotoluene; 2,6 -Diaminoanthraquinone; 2,6-diaminotoluene; 2,3-diaminotoluene; 1,8-diaminonaphthalene; 2,4-diaminotoluene; 2,5-diaminotoluene; 1,4-diaminoanthraquinone; 1,5- Diaminoanthraquinone; 1,5-diaminonaphthalene; 1,2-diaminoanthraquinone; 2,4-kumendiamine; 1,3-bisaminomethylbenzene; 1,3-bisaminomethylcyclohexane; 2-chloro-1,4- Diaminobenzene; 1,4-diamino-2,5-dichlorobenzene; 1,4-diamino-2,5-dimethylbenzene; 4,4'-diamino-2,2'-bistrifluoromethylbiphenyl; bis (amino-) 3-Chloropheni) ethane; bis (4-amino-3,5-dimethylphenyl) methane; bis (4-amino-3,5-diethylphenyl) methane; bis (4-amino-3-ethyldiaminofluorene; diaminobenzo) Acids; 2,3-diaminonaphthalene; 2,3-diaminophenol; -5-methylphenyl) methane; bis (4-amino-3-methylphenyl) methane; bis (4-amino-3-ethylphenyl) methane; 4,4'-Diaminophenyl sulfone; 3,3'-diaminophenyl sulfone; 2,2-bis (4, (4 aminophenoxy) phenyl) sulfone; 2,2-bis (4- (3-aminophenoxy) phenyl) ) Compounds; 4,4'-oxydianiline;4,4'-diaminodiphenylsulfide; 3, 4'-oxydianiline; 2,2-bis (4- (4-aminophenoxy) phenyl) propane; 1,3-bis (4-aminophenoxy) benzene; 4,4'-bis (4-aminophenoxy) Biphenyl; 4,4'-diamino-3,3'-dihydroxybiphenyl;4,4'-diamino-3,3'-dimethylbiphenyl;4,4'-diamino-3,3'-dimethoxybiphenyl; Bisanyline P; 9,9-bis (4-aminophenyl) fluorene; o-tridin sulfone; methylenebis (anthranyl acid); 1,3-bis (4-aminophenoxy) -2,2-dimethylpropane; 1,3- Bis (4-aminophenoxy) propane; 1,4-bis (4-aminophenoxy) butane; 1,5-bis (4-aminophenoxy) butane; 2,3,5,6-tetramethyl-1,4- Phenylene diamine; 3,3', 5,5'-tetramethylbenzidine;4,4'-diaminobenzanilide; 2,2-bis (4-aminophenyl) hexafluoropropane; polyoxyalkylene diamines (eg,) Huntsman's Jeffamine D-230, D400, D-2000 and D-4000); 1,3-cyclohexanebis (methylamine); m-xylylene diamine; p-xylylene diamine; bis (4-amino-3-3). Methylcyclohexyl) methane; 1,2-bis (2-aminoethoxy) ethane; 3 (4), 8 (9) -bis (aminomethyl) tricyclo (5.2.2.102,6) decane; etc. However, a diamine compound composed of dimer acid having 30 to 40 carbon atoms, which is represented by the following general formula (4) or (5), is preferable. The diamine compounds represented by the following general formulas (4) and (5) are excellent in heat resistance and flexibility, and are excellent in low dielectric properties because they do not have a highly polar substituent. The diamine compounds represented by the following general formulas (4) and (5) are commercially available from Croda, Cognis, BASF and the like.

(A-1) As the acid dianhydride (c) used in synthesizing the maleimide compound, for example, pyromeritic anhydride; 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride; 1,4,5 , 8-naphthalenetetracarboxylic acid dianhydride; 3,4,9,10-perylenetetracarboxylic acid dianhydride; Bicyclo (2.2.2) Oct-7-en-2,3,5,6-tetra Carboic acid dianhydride; Diethylenetriaminepentaacetichydride dianhydride; Ethylenediamine tetraacetichydride dianhydride; 3,3', 4,4'-benzophenonetetracarboxylic acid dianhydride; 3,3', 4,4'-biphenyltetra Carboxydic dianhydride; 4,4'-oxydiphthalix anhydride; 3,3', 4,4'-diphenylsulfonetetracarboxylic acid dianhydride; 2,2'-bis (3,4-dicarboxy) Phenyl) Hexafluoropropane dianhydride; 4,4'-bisphenol A diphthalic anhydride; 5- (2,5-dioxytetrahydro) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride; ethylene Glycolbis (trimeritic acid anhydride); hydroquinone diphthalic acid anhydride; allyl nadic anhydride; 2-octen-1-ylsuccinic anhydride; 1,2,3,6-tetrahydrophthal Acid anhydrides; 3,4,5,6-tetrahydrophthalic anhydrides and the like can be mentioned, but from the viewpoint of cost, it is preferable to use pyromeritic anhydride.

(A-1) Examples of the acid compound (d) used when synthesizing a maleimide compound include sulfonic acids such as methanesulfonic acid, benzenesulfonic acid and p-toluenesulfonic acid, and organics such as formic acid, acetic acid and maleic acid. Acids and the like can be mentioned, but it is preferable to use methanesulfonic acid from the viewpoint of cost and reduction of side reactions.

In the present embodiment, the (A-1) maleimide compound is a compound represented by the following general formulas (1-1) to (1-3) from the viewpoint of further improving the low temperature curability and the heat resistance of the cured product. There may be. R1 and n in the general formulas (1-1) to (1-3) are synonymous with ^R1 and n in the general formula ( ¹ ).

More specifically, the compounds represented by the general formulas (1-1) to (1-3) include compounds represented by the following formulas (1-4) to (1-6). In equations (1-4) to (1-6), n represents an integer of 1 to 100.

(A-1) The molecular weight of the maleimide compound is not particularly limited. (A-1) The lower limit of the weight average molecular weight (Mw) of the maleimide compound may be 1000, 2000, 3000 or 5000. Further, the upper limit of Mw of the (A-1) maleimide compound may be 30,000, 20,000, 12,000 or 7,000. (A-1) The Mw of the maleimide compound may be 1000 to 30,000, 1500 to 20000, 1500 to 20000, 2000 to 12000, 2500 to 7000. May be.

(A-1) The Mw of the maleimide compound can be measured by a gel permeation chromatography (GPC) method.

The measurement conditions of GPC are as follows.
Pump: L-6200 type [manufactured by Hitachi High-Technologies Corporation]
Detector: L-3300 type RI [manufactured by Hitachi High-Technologies Corporation]
Column oven: L-655A-52 [manufactured by Hitachi High-Technologies Corporation]
Guard column and column: TSK Guardcolum HHR-L + TSKge
l G4000HHR + TSKgel G2000HHR [All manufactured by Tosoh Corporation, product name]
Column size: 6.0 x 40 mm (guard column), 7.8 x 300 mm (column)
Eluent: Tetrahydrofuran Sample concentration: 30 mg / 5 mL
Injection volume: 20 μL
Flow rate: 1.00 mL / min Measurement temperature: 30 ° C

The maleimide compound (A-2) represented by the general formula (2) is an amine compound (f) according to a known method (see, for example, Japanese Patent Publication No. 51-6153, US Pat. No. 3,018,290). Is synthesized by reacting maleic anhydride (e) with maleic anhydride (e) (maleimidization).

(A-2) Examples of the amine compound (f) used in synthesizing the maleimide compound include ethylenediamine; hexamethylenediamine; 2,2,4-trimethylhexamethylenediamine; phenylenediamines; tolylenediamines; 4 , 4'-diaminodiphenylmethane; 4,4'-diaminodiphenyl ether; 4,4'-diaminodiphenyl sulfone; 1,4-bis (4-aminophenoxy) benzene; 1,4-bis (4-aminobenzyl) benzene; 1,4-bis [1- (4-aminophenyl) -1-methylethyl] benzene; 9,9-bis [4- (4-aminophenoxy) phenyl] fluorene; bis [4- (4-aminophenoxy) Phenyl] sulfone; 1,4-bis {1- [4- (4-aminophenoxy) phenyl] -1-methylethyl} benzene; represented by the above general formula (4) or (5), having 30 to 30 carbon atoms. Examples thereof include a diamine compound composed of 40 dimer acids.

Examples of the maleimide compound using such an amine compound (f) include N, N'-(2,2,4-trimethylhexamethylene) bismaleimide; N, N'-decamethylene bismaleimide; N, N'. -Octamethylene bismaleimide; N, N'-heptamethylene bismaleimide; N, N'-hexamethylene bismaleimide; N, N'-pentamethylene bismaleimide; N, N'-tetramethylene bismaleimide; N, N' -Trimethylene bismaleimide; N, N'-ethylene bismaleimide; N, N'-(oxydimethylene) bismaleimide; 1,13-bismaleimide-4,7,10-trioxatridecane; 1,11- N, N'-(4-methyl-1,3-phenylene) bismaleimide; N, N'-(1), including aliphatic bismaleimide compounds such as bismaleimide-3,6,9-trioxaundecane , 3-Phenylene) bismaleimide; N, N'-(1,4-phenylene) bismaleimide; N, N'-(1,2-phenylene) bismaleimide; N, N'-(1,5-naphthylene) Bismaleimide; N, N'-(4-chloro-1,3-phenylene) Bismaleimide; N, N'-(methylenedi-p-phenylene) Bismaleimide; N, N'-(4,4'-biphenylene) Bismaleimide; N, N'-(sulfonyldi-p-phenylene) Bismaleimide; N, N'-(oxydi-p-phenylene) Bismaleimide; N, N'-(3,3'-dimethyl-4,4 '-Biphenylene) bismaleimide; N, N'-(benzylene di-p-phenylene) bismaleimide; N, N'-[methylenebis (3-chloro-4-phenylene)] bismaleimide; N, N'-[methylenebis (3-Methyl-4-phenylene)] bismaleimide; N, N'-[methylenebis (3-methoxy-4-phenylene)] bismaleimide; N, N'-(thiodi-p-phenylene) bismaleimide; N, N'-3,3'-benzophenone bismaleimide; N, N'-[methylenebis (3-methyl-5-ethyl-4-phenylene)] bismaleimide; N, N'-[tetramethylenebis (oxy-p-) Phenylene)] bismaleimide; 2,2-bis [4- (4-maleimide phenoxy) phenyl] propane; bis [4- (4-maleimide phenoxy) phenyl)] sulfone; 1,4-phenylene bis (4-maleimide phenoxy) ); Bis [3- (4-male Imidophenoxy) phenyl] sulfone; bis [4- (3-maleimide phenylthio) phenyl] ketone; 1,3-phenylene bis (4-maleimide phenoxy); bis [4- (4-maleimide phenylthio) phenyl] ether, etc. Examples include aromatic maleimide compounds. In this embodiment, one kind of maleimide compound may be used alone, or different kinds of maleimide compounds may be used in combination. The (A-2) maleimide compound represented by the general formula (2) is selected from a maleimide compound that does not correspond to the (A-1) maleimide compound represented by the general formula (1).

In the thermosetting resin composition of the present embodiment, as the (A) maleimide compound, only the (A-1) maleimide compound represented by the above general formula (1) may be used, and the above general formula (2) may be used. ) May be used alone, or both the (A-1) maleimide compound and the (A-2) maleimide compound may be used in combination, but the thermosetting resin composition may be used. Since the low-temperature curability of the product and the heat resistance of the obtained cured product can be compatible at a higher level, only the (A-1) maleimide compound is used, or the (A-1) maleimide compound and the (A-2) maleimide compound are used. It is preferable to use both compounds in combination. In either case, the (A-1) maleimide compound may be used alone or in combination of two or more, and the (A-2) maleimide compound may be used alone or in combination of two or more. May be used.

In the thermosetting resin composition of the present embodiment, the ratio of the (A-1) maleimide compound to the (A) maleimide compound determines the low temperature curability of the thermosetting resin composition and the heat resistance of the obtained cured product. It is preferably 30 to 100% by mass, more preferably 60 to 100% by mass, based on the total amount of the (A) maleimide compound, because it can be compatible at a higher level.

In the thermosetting resin composition of the present embodiment, the content of the (A) maleimide compound is 20 based on the total solid content of the composition excluding (C) the phosphonium salt from the entire thermosetting resin composition. It is preferably ~ 98% by mass, more preferably 50 to 95% by mass, and even more preferably 70 to 90% by mass. (A) When the content of the maleimide compound is 20% by mass or more, there is a tendency that a cured product having better heat resistance can be formed. (A) When the content of the maleimide compound is 98% by mass or less, the low temperature curability tends to be further improved.

In the present specification, the solid content means a non-volatile component under normal temperature and pressure conditions, and includes liquid, starch syrup-like and wax-like substances under normal temperature and pressure conditions. Therefore, the total amount of solid content of the thermosetting resin composition means the amount obtained by subtracting the amount of the volatile component (solvent or the like) from the total amount of the thermosetting resin composition.

The (B) epoxy group-containing compound used in the present embodiment can be used without particular limitation as long as it is a compound having at least two epoxy groups in one molecule. For example, bisphenol A type and bisphenol F type can be used. , Biphenyl type, novolak type, polyfunctional phenol type, naphthalene type, alicyclic type, alcohol type and other glycidyl ethers, glycidylamine type, glycidyl ester type and the like, and they may be used alone or they may be used alone. Two or more of these may be used in combination. Specifically, from the viewpoint of dielectric properties, heat resistance, moisture resistance and copper foil adhesiveness, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene ring-containing epoxy resin, anthracene type epoxy resin, biphenyl type epoxy resin, Phenolic aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, phenol novolac type epoxy resin, and cresol novolac type epoxy resin are preferable, and naphthalene ring-containing epoxy resin and anthracene type are excellent because they have good low thermal expansion and high glass transition temperature. More preferably, an epoxy resin, a biphenyl type epoxy resin, a phenol aralkyl type epoxy resin, a biphenyl aralkyl type epoxy resin, and a phenol novolac type epoxy resin.

The epoxy group-containing compound (B) contained in the thermosetting resin composition of the present embodiment preferably contains a compound represented by the following general formula (6) or (7).

In the general formula (6), R ⁸ independently represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 4 carbon atoms, R ⁹ independently represents a divalent organic group, and m is 1. Indicates an integer of ~ 10. Here, R ⁹ is preferably an aliphatic group having 1 to 10 carbon atoms, an ether group, or a group represented by the following general formula (6-1). R ^{8 in the general formula (6-1) is synonymous with R 8 in} the general formula (6).

In the general formula (7), R ⁸ independently represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 4 carbon atoms.

The epoxy equivalent of the (B) epoxy group-containing compound contained in the thermosetting resin composition of the present embodiment is preferably 150 to 300, preferably 160 to 280, from the viewpoint of further improving the low temperature curability. Is more preferable.

As the (B) epoxy group-containing compound contained in the thermosetting resin composition of the present embodiment, one type may be used alone, or two or more types may be used in combination.

The content of the (B) epoxy group-containing compound in the thermosetting resin composition of the present embodiment is based on the total solid content of the composition excluding (C) the phosphonium salt from the entire thermosetting resin composition. It is preferably 2 to 80% by mass, more preferably 15 to 70% by mass, and even more preferably 25 to 60% by mass.

By appropriately containing (B) the epoxy group-containing compound as described above, the thermosetting resin composition of the present embodiment can effectively exhibit low temperature curability and heat resistance of the cured product. .. (B) When the content of the epoxy group-containing compound is at least the above lower limit value (2% by mass), the curing temperature tends to be lower. On the other hand, when the content of (B) the epoxy group-containing compound is not more than the above upper limit value (80% by mass), the heat resistance of the cured product tends to be further improved.

The (C) phosphonium salt used in the present embodiment is a phosphonium salt having one or more carboxy groups in the anion species represented by the following general formula (3).

In the general formula (3), R ³ to R ⁷ each independently represent a monovalent organic group. The group bonded to the phosphorus atom of R ³ to R ⁶ in the general formula (3) is preferably a monovalent organic group or a monovalent aliphatic group having an aromatic ring or a heterocycle, and each of the phosphorus atom and each. The groups form a PC bond and they may be the same or different from each other. Since the low-temperature curability can be further improved, it is preferable that R ³ to R ⁶ are independently substituted or unsubstituted aliphatic groups having 1 to 10 carbon atoms, substituted or unsubstituted aromatic groups, and phenyl groups. , Methyl group, ethyl group, n-propyl group or n-butyl group is more preferable. Examples of such a phosphonium group include a tetraphenylphosphonium group, a tetratolylphosphonium group, a tetraethylphenylphosphonium group, a tetramethoxyphenylphosphonium group, a tetranaphthylphosphonium group, a tetrabenzylphosphonium group, an ethyltriphenylphosphonium group and an n-butyltriphenyl group. Examples thereof include a phosphonium group, a 2-hydroxyethyltriphenylphosphonium group, a trimethylphenylphosphonium group, a methyldiethylphenylphosphonium group, a methyldiallylphenylphosphonium group, a tetra-n-propylphosphonium group, a tetra-n-butylphosphonium group, and the like. It is not limited to these.

Examples of the anion species having one or more carboxy groups in the general formula (3) include acetic acid; propionic acid; butyric acid; caproic acid; enanthic acid; lauric acid; myristic acid; palmitic acid; stearic acid; phthalic acid; isophthalic acid. Telephthalic acid; hydroxyisophthalic acid; malonic acid; succinic acid; glutaric acid; adipic acid; 1,3-adamantandicarboxylic acid; azobenzene-4,4'-dicarboxylic acid; 1,3,5-benzenetricarboxylic acid; 1, 10-bis (4-carboxyphenoxy) decane; 2,2-bis (4-carboxyphenyl) hexafluoropropane; cis-4-cyclohexene-1,2-dicarboxylic acid; 1,4-cyclohexanedicarboxylic acid; 1,3 -Cyclohexanedicarboxylic acid; decahydro-1,4-naphthalenedicarboxylic acid; 2,3-pyrazindicarboxylic acid and the like, but are not limited thereto. R ⁷ in the general formula (3) can be an organic group corresponding to these anion species (that is, a residue obtained by removing the carboxy group from these anion species).

Examples of the phosphonium salt composed of such a cation species (phosphonium group) and an anion species include tetraphenylphosphonium-phthalic acid (cationic species: anion species = 1: 1, trade name "TPP-phthalic acid", Hokuko Chemical Industry Co., Ltd. (Manufactured by the company), Tetrabutylphosphonium-1,2- cyclohexanedicarboxylic acid (cationic species: anionic species = 1: 1.5, trade name "TBP-3", manufactured by Hokuko Kagaku Kogyo Co., Ltd.), tetrabutylphosphonium-1 , 2- Cyclohexanedicarboxylic acid (cationic species: anionic species = 1: 1, trade name "TBP-3S", manufactured by Hokuko Kagaku Kogyo Co., Ltd.), tetrabutylphosphonium-lauric acid (cationic species: anionic species = 1: 1) , Product name "TBPLA", manufactured by Hokuko Kagaku Kogyo Co., Ltd.) and the like. In this embodiment, one kind of phosphonium salt may be used alone, or different kinds of phosphonium salts may be used in combination.

In the thermosetting resin composition of the present embodiment, the content of the (C) phosphonium salt is 0.1 to 5. It is preferably 0 parts by mass, more preferably 1.0 to 4.0 parts by mass, and even more preferably 1.5 to 3.0 parts by mass. When the content of the (C) phosphonium salt is 5.0 parts by mass or less, the decomposition of the (C) phosphonium salt can be suppressed at a high temperature, and there is a tendency that a cured product having better heat resistance can be formed. (C) When the content of the phosphonium salt is 1.0 part by mass or more, the low temperature curability tends to be further improved.

The thermosetting resin composition of the present embodiment is prepared according to a generally adopted method. Examples of the preparation method include methods such as melt mixing, powder mixing, and solution mixing. In this case, as components other than the essential components of the present embodiment, for example, coloring pigments, plasticizers, solvents, leveling agents, organic fillers, inorganic fillers, molecular weight adjusting agents and the like are used without impairing the effects of the present invention. It may be blended in the range.

The thermosetting resin composition of the present embodiment can be molded according to a generally adopted method. For example, examples of the solvent-free system include a melt casting method, a melt impregnation method, a powder method, an RTM method, and examples of the solvent system include a resin solution impregnation method and a solvent coating method. be able to.

Heat curing is performed during this molding, and heating of 200 ° C. or higher is required in the prior art. However, by applying the thermosetting resin composition of the present embodiment, the curing temperature can be lowered. .. This is expected to simplify (rationalize) the molding process.

The thermosetting resin composition of the present embodiment has reduced cracks in GFRP, CFRP, etc. without impairing solvent-free impregnation, prepreg tackiness, drapeability, and storage stability, and is exposed to high temperatures for a long period of time. It is expected as a matrix resin having less weight loss, that is, having further improved heat resistance.

Further, the thermosetting resin composition of the present embodiment has copper foil adhesiveness, low thermal expansion property, high glass transition temperature, and excellent heat resistance, low dielectric resistance, solder heat resistance, flame retardancy, and drill workability. It is suitable for prepregs made of curable resin or laminated board applications.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

［式中、ｎは１～１０の整数を示す。］ [Example 1]
98 parts by mass of a bismaleimide compound having at least two imide bonds in one molecule represented by the following general formula (8), and a trade name "EPPN-501H" manufactured by Nippon Kayaku Co., Ltd. as an epoxy resin (hereinafter referred to as "EPPN-501H"). 2 parts by mass of EPPN-501H, tetrabutylphosphonium-1,2- cyclohexanedicarboxylic acid (cationic species: anionic species = 1: 1, trade name "TBP-3S" (hereinafter referred to as TBP-3S), Hokuko (Manufactured by Chemical Industry Co., Ltd.) 1.5 parts by mass was uniformly mixed to prepare a thermosetting resin composition.

[In the formula, n represents an integer from 1 to 10. ]

[Example 2]
82 parts by mass of the bismaleimide compound represented by the general formula (8), 18 parts by mass of EPPN-501H, and 1.5 parts by mass of TBP-3S are uniformly mixed to prepare a thermosetting resin composition. Prepared.

[Example 3]
50 parts by mass of the bismaleimide compound represented by the general formula (8), 50 parts by mass of EPPN-501H, and 1.5 parts by mass of TBP-3S are uniformly mixed to prepare a thermosetting resin composition. Prepared.

[Example 4]
98 parts by mass of the maleimide compound represented by the above general formula (8), 2 parts by mass of the trade name "YX4000" manufactured by Mitsubishi Chemical Corporation as an epoxy resin, and 1.5 parts by mass of TBP-3S uniformly. The mixture was mixed to prepare a thermosetting resin composition.

[Example 5]
91 parts by mass of the maleimide compound represented by the above general formula (8), 9 parts by mass of the trade name "YX4000" manufactured by Mitsubishi Chemical Corporation as an epoxy resin, and 1.5 parts by mass of TBP-3S uniformly. The mixture was mixed to prepare a thermosetting resin composition.

[Example 6]
A thermosetting resin composition was prepared in the same manner as in Example 1 except that the blending amount of TBP-3S was changed to 3.0 parts by mass.

[Example 7]
Same as Example 1 except that tetrabutylphosphonium-lauric acid (cation species: anion species = 1: 1, trade name "TBPLA", manufactured by Hokuko Kagaku Kogyo Co., Ltd.) was used as the curing accelerator instead of TBP-3S. To prepare a thermosetting resin composition.

[Example 8]
As a maleimide compound, 82 parts by mass of m-phenylene bismaleimide (trade name "BMI-3000" (hereinafter referred to as BMI-3000), manufactured by Daiwa Kasei Co., Ltd.), 18 parts by mass of EPPN-501H, and 1 part of TBP-3S. A thermosetting resin composition was prepared by uniformly mixing with 5 parts by mass.

[Comparative Example 1]
A thermosetting resin composition was prepared by uniformly mixing 100 parts by mass of the bismaleimide compound represented by the general formula (8) and 1.5 parts by mass of TBP-3S.

[Comparative Example 2]
A thermosetting resin composition was prepared in the same manner as in Example 1 except that tetrabutylphosphonium bromide (trade name “TBP-BB”, manufactured by Hokuko Chemical Industry Co., Ltd.) was used instead of TBP-3S as a curing accelerator. Prepared.

[Comparative Example 3]
A thermosetting resin composition was prepared in the same manner as in Example 1 except that the curing accelerator TBP-3S was not used.

[Comparative Example 4]
A thermosetting resin composition was prepared in the same manner as in Example 4 except that the curing accelerator TBP-3S was not used.

[Comparative Example 5]
As a maleimide compound, 100 parts by mass of BMI-3000 and 1.5 parts by mass of TBP-3S were uniformly mixed to prepare a thermosetting resin composition.

<Measurement of curing temperature>
The curing temperature of the thermosetting resin composition obtained in each Example and Comparative Example was measured by a differential scanning calorimeter (DSC) under the following conditions. That is, the thermosetting resin composition was weighed in an aluminum liquid pan (manufactured by Rigaku Co., Ltd.) in an amount of 4.5 to 5.5 mg, and was onset under the conditions of a nitrogen flow rate of 30 mL / min and a temperature rise rate of 10 ° C./min. The temperature and peak top temperature were measured. As a measuring device, "Thermo plus DSC8230" manufactured by Rigaku Co., Ltd. was used. The lower the onset temperature, which is the temperature at which the exothermic reaction begins, and the peak top temperature, which is the temperature at which the amount of heat is maximized, the better the low-temperature curability. The results are shown in Table 1.

<Measurement of thermogravimetric reduction rate>
The thermosetting resin compositions obtained in each Example and Comparative Example were formed into a sheet and heated at 180 ° C. for 1 hour to obtain a cured film having a thickness of 30 μm. Approximately 10 mg of a test piece was cut out from the obtained cured film, placed in an Al pan, and thermogravimetric reduction from 40 ° C to 500 ° C with a nitrogen flow rate of 300 mL / min was performed by a TG / DTA measuring device (manufactured by Hitachi High-Tech Science Corporation). , Trade name "TG / GTA7200"), and the thermogravimetric reduction rate at 300 ° C. was determined. The results are shown in Table 1. The smaller the thermogravimetric reduction rate, the better the heat resistance.

As is clear from Table 1, a thermosetting resin composition (Example) containing a specific maleimide compound, a specific epoxy resin, and a specific phosphonium salt having one or more carboxy groups in the anion species is available. It was confirmed that the DSC onset temperature and the DSC peak top temperature were shifted to the lower temperature side as compared with the thermosetting resin composition (comparative example) containing no epoxy resin, and the low temperature curability was excellent. Further, it was confirmed that the cured product of the thermosetting resin composition of the example had excellent heat resistance.

According to the thermosetting resin composition of the present invention, the bismaleimide resin has excellent heat resistance (low thermal weight reduction rate, thermal oxidation stability, high temperature wettability), dimensional stability, processability and flame retardancy, and Since it can be cured at low temperature while maintaining the features of being a relatively inexpensive material, it can be used for advanced composite materials in advanced technology fields such as aviation, space, and defense industries, and composites in the electronic equipment industry, automobile industry, and other general industrial fields. It has great potential as a raw material for materials.

Claims (7)

(A) It has at least two maleimide groups represented by the following general formula (2) other than the maleimide compound represented by the following general formula (1) and the maleimide compound represented by the following general formula (1). One or more maleimide compounds selected from the group consisting of maleimide compounds, and
(B) as an epoxy resin, an epoxy group-containing compound having at least two epoxy groups in one molecule, and an epoxy group-containing compound.
(C) A phosphonium salt having one or more carboxy groups in the anion species represented by the following general formula (3),
Thermosetting resin composition containing.

[In the formula (1), ^R1 and Q are independently substituted or unsubstituted aliphatic groups having 1 to 100 carbon atoms, substituted or unsubstituted aromatic groups, substituted or unsubstituted heteroaromatic groups, respectively. Alternatively, it indicates a substituted or unsubstituted siloxane moiety having a silicon number of 2 to 100, and n represents an integer of 1 to 100. ]

[In formula (2), R ² represents a divalent group having an aromatic group and / or an aliphatic hydrocarbon group. ]

[In the formula (3), R ³ to R ⁶ each independently represent a substituted or unsubstituted monovalent aliphatic group having 1 to 10 carbon atoms or a substituted or unsubstituted monovalent aromatic group. , R ⁷ is acetic acid, propionic acid, butyric acid, caproic acid, enanthic acid, lauric acid, myristic acid, palmitic acid, stearic acid, phthalic acid, isophthalic acid, terephthalic acid, hydroxyisophthalic acid, malonic acid, succinic acid, glutaru Acid, adipic acid, 1,3-adamantandicarboxylic acid, azobenzene-4,4'-dicarboxylic acid, 1,3,5-benzenetricarboxylic acid, 1,10-bis (4-carboxyphenoxy) decane, 2,2- Bis (4-carboxyphenyl) hexafluoropropane, cis-4-cyclohexene-1,2-dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, decahydro- The residue obtained by removing one carboxy group from 1,4-naphthalenedicarboxylic acid or 2,3-pyrazindicarboxylic acid is shown. ] The thermosetting resin composition according to claim 1, wherein the maleimide compound (A) contains at least the maleimide compound represented by the general formula (1). Claim 1 or claim 1, wherein the content of the (C) phosphonium salt is 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the total amount of the (A) maleimide compound and the (B) epoxy group-containing compound. 2. The thermosetting resin composition according to 2. The thermosetting resin composition according to any one of claims 1 to 3, wherein the epoxy equivalent of the (B) epoxy group-containing compound is 150 to 300. In the general formula (3), any one of claims 1 to 4, wherein each of R ³ to R ⁶ independently represents a phenyl group, a methyl group, an ethyl group, an n-propyl group or an n-butyl group. The thermosetting resin composition according to. The thermosetting resin composition according to any one of claims 1 to 5, wherein the anion species in the (C) phosphonium salt is phthalic acid, 1,2-cyclohexanedicarboxylic acid or lauric acid. The claim comprises the phosphonium salt (C) comprising at least one selected from the group consisting of tetraphenylphosphonium-phthalic acid, tetrabutylphosphonium-1,2-cyclohexanedicarboxylic acid, and tetrabutylphosphonium-lauric acid. The thermosetting resin composition according to any one of 1 to 6.