阅读说明：本技术 热固性树脂组合物 (Thermosetting resin composition ) 是由 庄司信一郎 山本智义 于 2018-12-21 设计创作，主要内容包括：本发明的目的在于,提供具有快速的固化速度、极高的耐热性和极高的长期耐热性的氰酸酯系固化性树脂组合物以及使用该组合物的成型品和预浸料。本发明涉及热固性树脂组合物,其含有(A)氰酸酯化合物和/或(B)不饱和酰亚胺化合物,和(C)环状碳化二亚胺化合物。另外,本发明涉及含有如上所述的热固性树脂组合物的固化物的成型品,和在增强纤维基材中浸渗有如上所述的热固性树脂组合物的预浸料。(The purpose of the present invention is to provide a cyanate ester-based curable resin composition having a rapid curing rate, extremely high heat resistance, and extremely high long-term heat resistance, and a molded article and a prepreg using the same. The present invention relates to a thermosetting resin composition containing (A) a cyanate ester compound and/or (B) an unsaturated imide compound, and (C) a cyclic carbodiimide compound. The present invention also relates to a molded article containing a cured product of the thermosetting resin composition described above, and a prepreg obtained by impregnating a reinforcing fiber base material with the thermosetting resin composition described above.)

1. A thermosetting resin composition comprising:

(A) a cyanate ester compound and/or (B) an unsaturated imide compound, and

(C) a cyclic carbodiimide compound.

2. The thermosetting resin composition according to claim 1, which contains the (a) cyanate ester compound.

3. The thermosetting resin composition according to claim 2, wherein the (a) cyanate ester compound has at least 2 cyanate groups in 1 molecule.

4. The thermosetting resin composition according to claim 2 or 3, wherein the (A) cyanate ester compound is a compound represented by the following formula (1):

[ chemical formula 1]

In the formula, R¹And R²The same or different, represent a hydrogen atom, an alkyl group or a haloalkyl group having 1 to 20 carbon atoms, or a halogen group;

R³the same or different, represent an organic group represented by the following chemical formula:

[ chemical formula 2]

R³：、、、、、、Or；

R⁴The same or different, represent an organic group represented by the following chemical formula:

[ chemical formula 3]

；

k is 0 or 1; and l represents an integer of 0 to 10.

5. The thermosetting resin composition according to claim 1, which contains the (B) unsaturated imide compound.

6. The thermosetting resin composition according to claim 5, wherein the unsaturated imide compound (B) is a bismaleimide compound.

7. The thermosetting resin composition according to any one of claims 1 to 6, wherein the cyclic carbodiimide compound (C) is a compound containing at least 1 cyclic structure represented by the following general formula (2):

[ chemical formula 4]

In the formula, Q is a 2-4 valent bonding group which may contain a hetero atom and/or a substituent as an aliphatic group, an alicyclic group, an aromatic group or a combination thereof.

8. The thermosetting resin composition according to any one of claims 1 to 7, wherein the (C) cyclic carbodiimide compound is a compound represented by the following formula (2-1):

[ chemical formula 5]

In the formula, X is a 4-valent group represented by the following formula (i):

[ chemical formula 6]

；

Ar¹~Ar⁴Independently represents a 2-valent monocyclic or condensed polycyclic alicyclic group, aromatic group or heterocyclic group which may have a substituent selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group and an aldehyde group, wherein Ar is a substituent¹~Ar⁴In the case of a heterocyclic group, the heterocyclic group contains a heteroatom selected from O, N, S and P.

9. The thermosetting resin composition according to any one of claims 1 to 8, which contains:

the (A) cyanate ester compound is a compound having a structure,

the (B) unsaturated imide compound, and

the cyclic carbodiimide compound (C).

10. The thermosetting resin composition according to claim 9, wherein the cyclic carbodiimide compound (C) is contained in an amount of 1 to 30 parts by mass based on 100 parts by mass of the sum of the cyanate ester compound (A) and the unsaturated imide compound (B).

11. The thermosetting resin composition according to claim 9 or 10, wherein the (a) cyanate ester compound and the (B) unsaturated imide compound are contained at a mass ratio of 90:10 to 50: 50.

12. A molded article comprising a cured product of the thermosetting resin composition according to any one of claims 1 to 11.

13. A prepreg impregnated with the thermosetting resin composition according to any one of claims 1 to 11 in a reinforcing fiber base material.

14. A fiber-reinforced composite material obtained by curing the prepreg according to claim 13.

Technical Field

The present invention relates to a thermosetting resin composition.

Background

The cyanate ester compound is a compound having a cyanate group (-OCN). It is known that the compound is polymerized while cyclizing and trimerizing to form a triazine ring structure, and the cured resin has very high heat resistance derived from the triazine ring structure. Therefore, the cured resin of the cyanate ester compound is used in electronic material applications such as materials for printed wiring boards, and in fields requiring high functionality such as aerospace applications.

Patent documents 1 and 2 disclose such cyanate ester-based compositions.

Further, unsaturated imide compounds are also known as the same cured resin. A typical unsaturated imide compound is a bismaleimide compound, and it is known that an unsaturated bond of a maleimide group is polymerized to obtain a cured resin having very high heat resistance. The unsaturated imide compound may also be used as a co-curing reactive compound to co-cure with the cyanate ester compound.

Patent document 3 discloses that, in order to suppress hydrolysis of a polyester, a carboxyl group at the end of the polyester is blocked with a cyclic carbodiimide compound. Further, patent document 4 discloses an epoxy resin composition containing a cyclic carbodiimide compound as a curing agent, and discloses that such an epoxy resin composition has high heat resistance.

Disclosure of Invention

Problems to be solved by the invention

The purpose of the present invention is to provide a cyanate ester-based curable resin composition having a rapid curing rate, extremely high heat resistance, and extremely high long-term heat resistance, and a prepreg using the same.

Means for solving the problems

The present inventors have found that the above problems can be solved by the present invention having the following configurations.

Scheme 1

A thermosetting resin composition comprising:

(A) a cyanate ester compound and/or (B) an unsaturated imide compound, and

(C) a cyclic carbodiimide compound.

Scheme 2

The thermosetting resin composition according to scheme 1, which contains the (a) cyanate ester compound.

Scheme 3

The thermosetting resin composition according to scheme 2, wherein the (a) cyanate ester compound has at least 2 cyanate groups in 1 molecule.

Scheme 4

The thermosetting resin composition according to scheme 2 or 3, wherein the (a) cyanate ester compound is a compound represented by the following formula (1):

[ chemical formula 1]

In the formula, R¹And R²The same or different, represent a hydrogen atom, an alkyl group or a haloalkyl group having 1 to 20 carbon atoms, or a halogen group;

R³the same or different, represent an organic group represented by the following chemical formula:

[ chemical formula 2]

R³：、、、、、、Or；

R⁴The same or different, represent an organic group represented by the following chemical formula:

[ chemical formula 3]

；

k is 0 or 1; and l represents an integer of 0 to 10.

Scheme 5

The thermosetting resin composition according to scheme 1, which contains the (B) unsaturated imide compound.

Scheme 6

The thermosetting resin composition according to scheme 5, wherein the unsaturated imide compound (B) is a bismaleimide compound.

Scheme 7

The thermosetting resin composition according to any one of aspects 1 to 6, wherein the cyclic carbodiimide compound (C) is a compound containing at least 1 cyclic structure represented by the following general formula (2):

[ chemical formula 4]

In the formula, Q is a 2-4 valent bonding group which may contain a hetero atom and/or a substituent as an aliphatic group, an alicyclic group, an aromatic group or a combination thereof.

Scheme 8

The thermosetting resin composition according to any one of aspects 1 to 7, wherein the (C) cyclic carbodiimide compound is a compound represented by the following formula (2-1):

[ chemical formula 5]

In the formula, X is a 4-valent group represented by the following formula (i):

[ chemical formula 6]

；

Ar¹~Ar⁴Independently represents a 2-valent monocyclic or condensed polycyclic alicyclic group, aromatic group or heterocyclic group which may have a substituent selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group and an aldehyde group, wherein Ar is a substituent¹~Ar⁴In the case of a heterocyclic group, the heterocyclic group contains a heteroatom selected from O, N, S and P.

Scheme 9

The thermosetting resin composition according to any one of aspects 1 to 8, which contains:

the (A) cyanate ester compound is a compound having a structure,

the (B) unsaturated imide compound, and

the cyclic carbodiimide compound (C).

Scheme 10

The thermosetting resin composition according to claim 9, wherein the cyclic carbodiimide compound (C) is contained in an amount of 1 to 30 parts by mass based on 100 parts by mass of the sum of the cyanate ester compound (a) and the unsaturated imide compound (B).

Scheme 11

The thermosetting resin composition according to claim 9 or 10, wherein the (a) cyanate ester compound and the (B) unsaturated imide compound are contained at a mass ratio of 90:10 to 50: 50.

Scheme 12

A molded article comprising a cured product of the thermosetting resin composition according to any one of claims 1 to 11.

Scheme 13

A prepreg obtained by impregnating a reinforcing fiber base material with the thermosetting resin composition according to any one of claims 1 to 11.

Scheme 14

A fiber-reinforced composite material obtained by curing the prepreg according to claim 13.

Detailed Description

Thermosetting resin composition

The thermosetting resin composition of the present invention contains (A) a cyanate ester compound and/or (B) an unsaturated imide compound, and (C) a cyclic carbodiimide compound.

As described above, it is considered that (a) the cyanate ester compound generates a triazine ring structure by cyclizing trimerization of the cyanate group (-OCN), and thus the cyanate ester resin exhibits very high heat resistance. In addition, it is also known that (B) unsaturated imide compounds, maleimide unsaturated bond polymerization, thereby having very high heat resistance of the cured resin.

The present inventors have found that the cyanate ester-based resin having such very high heat resistance and/or the unsaturated imide compound (B) can be a polymer having a higher glass transition temperature only by containing a small amount of a cyclic carbodiimide compound in the monomer thereof. In addition, the heat resistance of the conventional resin is deteriorated when the resin is treated at a high temperature for a long time, whereas the heat resistance of the cured resin obtained from the resin composition of the present invention is not substantially deteriorated even when the resin is treated at a high temperature for a long time. It is very difficult to obtain a cyanate-based cured resin or an imide-based cured resin having such extremely high heat resistance and extremely high long-term heat resistance by the conventional technique, and it is expected to further expand the application range of the resin in fields requiring high functionality such as electronic material applications and aerospace applications.

Further, it is found that the thermosetting resin composition of the present invention has a higher curing rate than a composition containing no cyclic carbodiimide compound. It is unexpected that the cured product of the composition of the present invention has extremely high heat resistance and extremely high long-term heat resistance, although the curing reaction of the composition starts early as compared with a composition containing no cyclic carbodiimide compound.

Without being bound by theory, it is believed that the thermosetting resin composition of the present invention, by containing the cyclic carbodiimide compound, a reaction between the cyanate group and/or the unsaturated imide group and the carbodiimide group occurs in addition to the polymerization reaction of the cyanate ester compound and/or the polymerization reaction of the unsaturated imide compound. It is considered that a heterocyclic ring having a high nitrogen content is formed by a reaction between these functional groups and a carbodiimide group, and thus extremely high heat resistance is exhibited. Even if thermal decomposition of the cyanate ester compound and/or the unsaturated imide compound occurs, the carbodiimide group reacts so as to be repaired at the end cleaved by the thermal decomposition, and the isocyanate group generated thereby further becomes a curing component, whereby long-term heat resistance can be exhibited.

[ cyanate ester Compound (A) ]

The thermosetting resin composition of the present invention may contain (a) a cyanate ester compound. (A) The cyanate ester compound is not particularly limited as long as it has a cyanate group (-OCN), and is preferably a compound having at least 2 cyanate groups in 1 molecule, and more preferably a compound having at least 2 cyanate groups and at least 1 aromatic ring or fused aromatic ring in 1 molecule. For example, the cyanate ester compound (A) may be a compound containing 2 to 4 or 2 to 3 cyanate groups and 1 to 3 or about 2 aromatic rings or condensed rings which may have a substituent. In the present specification, (a) the cyanate ester compound includes a cyanate ester compound and a prepolymer thereof.

Specific examples of the (a) cyanate ester compound include: 1, 3-or 1, 4-dicyanobenzene, 1,3, 5-tricarbonylbenzene, 1,3-, 1,4-, 1,6-, 1,8-, 2, 6-or 2, 7-dicyanobenzene, 1,3, 6-tricarbonylnaphthalene, 4, 4-dicyanobenzene, bis (4-cyanatophenyl) methane, bis (3, 5-dimethyl-4-cyanatophenyl) methane, 2, 2-bis (4-cyanatophenyl) propane, 2, 2-bis (3, 5-dibromo-4-cyanatophenyl) propane, 2, 2-bis (3, 5-dimethyl-4-cyanatophenyl) propane, bis (4-cyanatophenyl) ether, bis (4-cyanate ylphenyl) sulfide, bis (4-cyanate ylphenyl) sulfone, tris (4-cyanate ylphenyl) phosphite, tris (4-cyanate ylphenyl) phosphate, cyanate ester compounds obtained by reacting a nitrile halide with a cyanate ester such as novolak or an oligomer of a hydroxyl group-containing thermoplastic resin (e.g., a hydroxy polyphenylene ether, a hydroxy polystyrene, a hydroxy polycarbonate) or the like, cyanate ester compounds obtained by reacting a nitrile halide with a polyfunctional phenol in which phenol is bonded with dicyclopentadiene, or the like; also, 1 or more than 2 kinds may be suitably mixed and used.

Preferred cyanate ester compounds (a) include 1, 3-or 1, 4-dicyanobenzene, 1,3, 5-tricarbonylbenzene, bis (3, 5-dimethyl-4-cyanatophenyl) methane, bis (4-cyanatophenyl) methane, 2-bis (4-cyanatophenyl) propane and phenol novolac cyanate ester, and particularly preferred is 2, 2-bis (4-cyanatophenyl) propane, and a prepolymer having a molecular weight of 400 to 6,000 and having a triazine ring formed by trimerization of cyanate ester groups of the cyanate ester compounds is preferably used.

For example, the cyanate ester compound (a) may be a compound represented by the following formula (1).

[ chemical formula 7]

In the formula, R¹And R²The same or different, represent a hydrogen atom, an alkyl group or a haloalkyl group having 1 to 20 carbon atoms, or a halogen group；

R³The same or different, represent an organic group represented by the following chemical formula:

[ chemical formula 8]

R³：、、、、、、Or；

R⁴The same or different, represent an organic group represented by the following chemical formula:

[ chemical formula 9]

；

k is 0 or 1; and l represents an integer of 0 to 10.

The compound represented by the formula (1) is repeated with specific examples of the cyanate ester compound, and examples thereof include divalent cyanate ester type novolak varnish such as bis (4-cyanate ester phenyl) methane, bis (3, 5-dimethyl-4-cyanate ester phenyl) methane, bis (3-methyl-4-cyanate ester phenyl) methane, bis (4-cyanate ester phenyl) -1, 1-ethane, bis (4-cyanate ester phenyl) -2, 2-ethane, 2-bis (4-cyanate ester phenyl) propane, 2-bis (3, 5-dimethyl-4-cyanate ester phenyl) methane, bis (4-cyanate ester phenyl) ether, bis (4-cyanate ester phenyl) sulfide, 4- {1, 3-phenylenebis (1-methylethylidene) } bisphenylcyanate ester, 4-dicyanate phenyl, 2-bis (4-cyanate ester phenyl) -1,1, 3,3, 3-hexafluoropropane, 1,1' -bis- (p-phenyl) -ethane, 2' -bis (p-cyanate ester phenyl) propane, 2-bis (4-cyanate ester phenyl) -1,1,1,3,3, 3-hexafluoropropane, 1,1, 1' -bis- (p-cyanate ester phenyl) -ethane, 2' -bis (p-cyanate ester phenyl) propane, 2, 4-cyanate ester, 2, 4-bis (4-cyanate ester phenyl) propane, 2-bis (4-cyanate ester phenyl) cyanate ester, 2, 4-cyanate ester, 2-cyanate ester, 4-bis (4-cyanate ester phenyl) cyanate ester type novolak ester type varnish, 2' -bisphenol type novolak type.

As the cyanate ester compound (a), a prepolymer (for example, trimer or pentamer) having a triazine ring structure cyclized by a cyanate group contained in the compound represented by the formula (1) can be used. Among them, the trimer is preferable from the viewpoint of handling properties and solubility in other curable resins.

The prepolymer can be obtained by polymerizing the monomer of the cyanate ester compound with, for example, an acid such as an inorganic acid or a lewis acid, a base such as sodium alkoxide or the like, a tertiary amine or the like, a salt such as sodium carbonate or the like as a catalyst.

(B) unsaturated imide Compound

The thermosetting resin composition of the present invention may contain (B) an unsaturated imide compound. (B) The unsaturated imide compound is a compound having an unsaturated imide group which can be independently subjected to a curing reaction and can be reacted with a cyanate ester compound to cure the composition. In the present specification, the unsaturated imide compound (B) includes unsaturated imide compounds and prepolymers thereof. Here, the unsaturated imide group means an imide group having a polymerizable unsaturated bond.

The compound having an unsaturated imide group is not particularly limited, and a compound having a maleimide group or a nadimide group (nadimide) is preferable.

The compound having a maleimide group is not particularly limited, and a bismaleimide compound (bismaleimide resin) can be mentioned. The bismaleimide compound is not particularly limited as long as it has 2 or more maleimide groups in the molecule, and examples thereof include a cocondensate of bismaleimide and an aldehyde compound, and 1 or 2 or more of them can be used. Examples of the compound having a maleimide group include an aromatic maleimide having a maleimide group bonded to an aromatic ring, and particularly include an aromatic bismaleimide having a maleimide group bonded to each of 2 aromatic rings.

Examples of the bismaleimide compound include 4,4 '-diphenylmethane bismaleimide, N' -ethylenebismaleimide, N '-hexamethylenebismaleimide, N' -m-phenylenebbismaleimide, N '-p-phenylenebbismaleimide, 2-bis [4- (4-maleimidophenoxy) phenyl ] propane, bis [4- (4-maleimidophenoxy) phenyl ] methane, 1,1,1,3,3, 3-hexafluoro-2, 2-bis [4- (4-maleimidophenoxy) phenyl ] propane, N' -p, p '-diphenyldimethylsilylbismaleimide, N' -4,4 '-diphenyl ether bismaleimide, N' -methylenebis (3-chloro-p-phenylene) bismaleimide, N '-4,4' -diphenylsulfone bismaleimide, N '-4,4' -dicyclohexylmethane bismaleimide, N '-dimethylenecyclohexane bismaleimide, N' -m-xylene bismaleimide, N '-4,4' -diphenylcyclohexane bismaleimide, N-phenylmaleimide, polyphenylmethanemaleimide, and the like. Among these, examples of the aldehyde compound include formaldehyde, acetaldehyde, benzaldehyde, and hydroxybenzaldehyde.

The above-mentioned compound having a nadimide group is not particularly limited, but is preferably a product obtained by imidization reaction of an aromatic amine compound and norbornene dicarboxylic anhydride, and the nadimide compound is not particularly limited as long as it has 2 or more nadimide groups in the molecule, and 1 or 2 or more of them can be used.

Examples of the nadimide compound include 4,4' -diphenylmethane-bis-nadimide, N ' -ethylenebis-nadimide, N ' -hexamethylenebis-nadimide, N ' -m-phenylenebis-nadimide, N ' -p-phenylenebis-nadimide, 2-bis [4- (4-nadimidophenoxy) phenyl ] propane, bis [4- (4-nadimidophenoxy) phenyl ] methane, 1,1,1,3, 3-hexafluoro-2, 2-bis [4- (4-nadimidophenoxy) phenyl ] propane, N ' -p, p ' -diphenyldimethylsilylbis-nadimide, N ' -p, p ' -diphenyldimethylsilylbis-nadimide, N, N ' -4,4' -diphenyl ether bisamideimide, N ' -methylenebis (3-chloro-p-phenylene) bisamideimide, N ' -4,4' -diphenylsulfone bisnadimide, N ' -4,4' -dicyclohexylmethane bisnadimide, N ' -dimethylenecyclohexane bisnadimide, N ' -m-xylene bisnadimide, N ' -4,4' -diphenylcyclohexane bisnadimide, N-phenylnadimide, and the like. Among these, examples of the aldehyde compound include formaldehyde, acetaldehyde, benzaldehyde, and hydroxybenzaldehyde.

The unsaturated imide compound (B) may be contained in the thermosetting resin composition in a mass part of 10 parts by mass or more, 20 parts by mass or more, 50 parts by mass or more, 100 parts by mass or more, 150 parts by mass or more, or 20 parts by mass or more with respect to 100 parts by mass of the cyanate ester compound (a), and may be contained in the thermosetting resin composition in a mass part of 500 parts by mass or less, 400 parts by mass or less, 300 parts by mass or less, 200 parts by mass or less, 150 parts by mass or less, 100 parts by mass or less, 50 parts by mass or less, or 30 parts by mass or less. For example, the thermosetting resin composition may contain (A) a cyanate ester compound and (B) an unsaturated imide compound in a mass ratio of 90:10 to 50:50 or 80:20 to 60: 40.

(C) Cyclic carbodiimide Compound

As the cyclic carbodiimide compound (C), the cyclic carbodiimide compounds described in patent documents 3 and 4 can be used.

For example, the (C) cyclic carbodiimide compound may be a compound containing at least 1 cyclic structure composed of 8 or more, or 10 or more, and 50 or less, 30 or less, 20 or less, or 15 or less atoms, and containing a 2-valent carbodiimide group (-N = C = N-) in a part of the cyclic structure. In this case, the number of the cyclic structure may be 2 or more, or may be a spiro structure. The carbodiimide group may be contained in each of these cyclic structures, or may contain only 1 in 1 cyclic portion. (C) The cyclic carbodiimide compound preferably has only 1 carbodiimide group in 1 cyclic structure.

The number of atoms in the cyclic structure means the number of atoms directly constituting the cyclic structure, and for example, 8 is the case of an 8-membered ring, and 50 is the case of a 50-membered ring. When the number of atoms in the cyclic structure is in the range of 8 to 50, the stability of the cyclic carbodiimide compound can be maintained to a certain extent, and therefore storage and use are easy. From the viewpoint of reactivity, the upper limit of the number of ring members is not particularly limited, and the cyclic carbodiimide compound (C) having an atomic number of 50 or less is easily synthesized. From such a viewpoint, the number of atoms in the cyclic structure is preferably 10 to 30, more preferably 10 to 20, and particularly preferably 10 to 15.

From the viewpoint of improving the heat resistance of the cured resin, the cyclic carbodiimide compound (C) is preferably a polyvalent cyclic carbodiimide compound containing 2 or more carbodiimide groups in 1 molecule. Particularly when used as a curing agent for thermosetting resin compositions, it is preferable that 1 molecule contains 2 or 3 carbodiimide groups from the viewpoint of curability. These cyclic carbodiimide compounds can be used in combination of 2 or more.

(C) The molecular weight of the cyclic carbodiimide compound is preferably 100 to 1,000. When the amount is within the above range, the cyclic carbodiimide compound (C) is less likely to cause problems in structural stability, volatility, and the like, and the yield in synthesizing the cyclic carbodiimide compound (C) is high. From such a viewpoint, the content is more preferably 100 to 750, and still more preferably 250 to 750.

For example, (C) the cyclic carbodiimide compound may be a compound having a cyclic structure represented by the following general formula (2):

[ chemical formula 10]

In the formula, Q is a 2-4 valent bonding group which may contain a hetero atom and/or a substituent as an aliphatic group, an alicyclic group, an aromatic group or a combination thereof.

In the formula, Q is preferably represented by-Ar^a-O-X-O-Ar^b-a group represented by (a). Ar (Ar)^aAnd Ar^bEach independently may be a monocyclic or fused polycyclic alicyclic group, aromatic group or heterocyclic group which may have a substituent, preferably a phenylene group or naphthalenediyl group which may have a substituent. In this case, the substituent includes an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, an aldehyde group, etc., and is preferably an alkyl group having 1 to 6 carbon atoms or a phenyl group. X is preferably an alkanediyl group when it has 2 cyclic structures. In the case of 4 cyclic structures, an alkanetetrayl group is preferred.

Examples of the cyclic carbodiimide compound (C) include compounds represented by the formula (2-1).

[ chemical formula 11]

Wherein X is a 4-valent group represented by the following formula (i). In the formula Ar¹~Ar⁴Each independently is a 2-valent monocyclic or fused polycyclic alicyclic group, aromatic group or heterocyclic group which may have a substituent, preferably an o-phenylene group or a 1, 2-naphthalenediyl group which may have a substituent. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group. In addition, in Ar¹~Ar⁴In the case of a heterocyclic group, the heterocyclic group containsA heteroatom selected from O, N, S and P.

[ chemical formula 12]

Examples of the (C) cyclic carbodiimide compound which can be preferably used include compounds represented by the following formula (2-2) or (2-3).

[ chemical formula 13]

[ chemical formula 14]

The cyclic carbodiimide compound (C) may be contained in the thermosetting resin composition in a mass part of 1 part by mass or more, 3 parts by mass or more, 5 parts by mass or more, 10 parts by mass or more, 12 parts by mass or more, or 15 parts by mass or more with respect to 100 parts by mass of the cyanate ester compound (a) and/or the unsaturated imide compound (B), and may be contained in the thermosetting resin composition in a mass part of 30 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, or 10 parts by mass or less.

< others >

The thermosetting resin composition of the present invention can be used in combination with other thermosetting resins or thermoplastic resins such as epoxy resin and phenol resin depending on the application. As such a resin, a resin disclosed as a resin that can be used in combination with the resin described in patent document 2 can be mentioned. On the other hand, in the present invention, in order to obtain extremely high heat resistance, a composition containing no such other resin is also preferable. For example, in the thermosetting resin composition of the present invention, the total of (a) the cyanate ester compound, (B) the unsaturated imide compound and (C) the cyclic carbodiimide compound is 100 parts by mass, the content of the other resin components may be 50 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, 10 parts by mass or less, 5 parts by mass or less, 3 parts by mass or less, 1 part by mass or less or 0.1 part by mass or less.

The thermosetting resin composition of the present invention is cured by heating, and a known curing catalyst or curing accelerator may be further added to further accelerate the curing.

In the thermosetting resin composition of the present invention, various additives may be added in a range not impairing the inherent properties of the composition depending on the purpose of the end use. These additives include natural or synthetic resins, inorganic or organic fibrous reinforcing agents or fillers, and may be used in combination as needed. Further, various additives such as dyes, pigments, thickeners, lubricants, antifoaming agents, dispersing agents, leveling agents, photosensitizers, flame retardants, gloss agents, polymerization inhibitors, thixotropic agents, and the like may be used in combination as needed.

Method for curing thermosetting resin

The curing conditions of the thermosetting resin composition vary depending on the composition ratio of the resin composition, the presence or absence of an additional curing catalyst or curing accelerator, etc., and are usually appropriately selected within the range of 100 to 300 ℃. The pressure at this time is not particularly limited, but pressurization is generally preferred, and may be appropriately selected from the range of usually 0.01 to 50MPa, preferably 0.5 to 15 MPa.

Molded article

The molded article of the present invention can be obtained by curing the thermosetting resin composition, and can have various forms such as a plate form, a sheet form, a three-dimensional form, and the like. When a molded article is obtained, a known molding method such as transfer molding, sheet molding, compression molding, or press molding can be used. The thermosetting resin composition in a liquid form may be applied to a sheet base material by a bar coater, die coater, doctor blade, baker applicator (baker applicator) or the like and cured to form a laminate with the sheet base material, or may be peeled from the sheet base material to form a sheet.

The use of the molded article includes a prepreg, a metal foil-clad laminate, a resin sheet, an insulating layer of a printed wiring board, a semiconductor sealing material, and the like.

Prepreg

The prepreg of the present invention is a prepreg obtained by impregnating a reinforcing fiber base material with the thermosetting resin composition. The prepreg of the present invention has extremely high heat resistance and extremely high long-term heat resistance, and therefore is very useful in fields requiring high functionality, such as electronic material applications and aerospace applications. The prepreg of the present invention can have the same configuration and production method as those of conventional prepregs formed from a thermosetting resin composition using a cyanate ester compound or the like.

Examples of the reinforcing fiber constituting the reinforcing fiber base material include carbon fiber, glass fiber, aramid fiber, silicon carbide fiber, polyester fiber, ceramic fiber, alumina fiber, boron fiber, metal fiber, mineral fiber, rock fiber, and slag fiber. Among these reinforcing fibers, carbon fibers, glass fibers and aramid fibers are preferable, carbon fibers that can provide a fiber-reinforced composite material having good specific strength and specific modulus, and being lightweight and high in strength are more preferable, and among the carbon fibers, Polyacrylonitrile (PAN) based carbon fibers having excellent tensile strength are particularly preferable.

The shape of the reinforcing fiber base material is not limited, and is preferably a sheet-like material from the viewpoint of processability. Examples of the reinforcing fiber sheet include a sheet obtained by doubling a plurality of reinforcing fibers in one direction, a two-way woven fabric such as a plain woven fabric or a twill woven fabric, a multiaxial woven fabric, a nonwoven fabric, a mat, a knitted fabric, a woven rope, and paper obtained by papermaking of reinforcing fibers. The thickness of the reinforcing fiber sheet is preferably 0.01 to 3mm, more preferably 0.1 to 1.5 mm. The weight per unit area of the reinforcing fiber sheet is preferably 70 to 400g/m²More preferably 100 to 300g/m²。

The content of the thermosetting resin composition in the prepreg is preferably 20 to 60 parts by mass, and more preferably 30 to 50 parts by mass, based on the total mass of the reinforcing fiber base material and the thermosetting resin composition. When the amount is within the above range, voids and the like are less likely to be generated in the fiber-reinforced composite material, and the reinforcing fiber content is sufficient, so that the strength of the prepreg to be obtained can be improved.

The prepreg can be prepared by impregnating the reinforcing fiber base material with the thermosetting resin composition described above. As a method for impregnating the reinforcing fiber base material with the thermosetting resin composition, a known wet method or dry method can be used. Among them, the hot melt method is preferred as the dry method.

In the hot melt method, the thermosetting resin composition and the stacked reinforcing fiber base material are heated under pressure to reduce the viscosity of the thermosetting resin composition and impregnate the reinforcing fiber base material. In the case where the reinforcing fiber base material is a sheet-like material, the resin composition molded into a film-like shape is preferably stacked on the reinforcing fiber base material.

Fiber-reinforced composite Material

Examples of methods for producing a fiber-reinforced composite material using the prepreg include conventionally known methods, such as methods using hand lay-up, automatic tape lay-up (AT L), automatic fiber placement, vacuum bag molding (vacuum bagging), autoclave curing, curing outside of autoclave, fluid-assisted processing, pressure-assisted processing, matched mold processing (match mold process), simple press curing, press close (プレスクレーブ) curing, or continuous belt press.

The fiber-reinforced composite material described above may be a copper-clad laminate obtained by laminating a copper foil on a prepreg and curing the laminate, or may be a printed wiring board produced from the copper-clad laminate.

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto.