JPS62207364A - Curable resin composition - Google Patents

Abstract

PURPOSE:To provide the titled resin compsn. which has excellent workability, gives cured articles having excellent heat resistance, etc., and is suitable for use in the production of laminated sheets, etc., by mixing a thermosetting resin compsn. contg. a polyfunctional cyanic ester with a specified epoxy resin- modified butadiene copolymer. CONSTITUTION:A thermosetting resin compsn. contg. a polyfunctional cyanic ester (prepolymer) having cyanato groups or a prepolymer of a cyanic ester with an amine as essential ingredients is prepd. as a component A. Separately, a butadiene/arom. vinyl compd. copolymer which has carboxyl groups and a m.p. of not lower than 10 deg.C and wherein at least 50% of butadiene units in the polymer chain are composed of 1,2-bonded butadiene units is modified with a polyfunctional epoxy resin to prepare an epoxy resin-modified butadiene copolymer (component B) having a m.p. of not lower than 10 deg.C and an epoxy equivalent of 300-8,000. The component A is mixed with the component B to obtain the titled resin compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel curable resin composition containing a cyanate ester resin composition and a specific epoxy-modified butadiene copolymer as main components. and relates to a novel curable resin composition that provides a cured product with excellent workability and excellent heat resistance, adhesiveness, electrical properties, etc.
In particular, by utilizing its excellent dielectric properties, it is suitably used in the production of laminates for printed wiring boards, various molding materials, paints, etc., which require a low dielectric constant and low dielectric loss tangent.

[Conventional technology]

Applications that require dielectric properties such as low dielectric constant and low dielectric loss tangent,
For example, polytetrafluoroethylene is used for printed wiring boards for high-speed arithmetic circuits and high-frequency circuits, and polyfunctional cyanate ester resin is used for printed wiring laminates that use thermosetting resins. Composition of composition and 1,2-polybutadiene resin (Japanese Patent Application Laid-open No. 1423-1983
No. 00, JP-A-55-98244, JP-A-57-14
3350).

[Problem that the invention seeks to solve]

In a composition of a polyfunctional cyanate ester resin composition and 1,2-polybutadiene, when a liquid 1,2-polybutadiene having a normal molecular weight i of about 000 to 5,000 is used, There was a problem that the compatibility was not sufficient and the composition was sticky, so it could not be used for applications such as prepregs, pellets for molding, and powder coatings that required non-stick properties. To improve this, there is a method of using a substance with a molecular weight of about 100,000, and although this method eliminates the stickiness, it has poor compatibility with cyanate esters and solubility in general-purpose solvents, making it difficult to work. becomes inferior. Furthermore, these methods have a common drawback of poor adhesion.

In addition, in the case of the method of using 1.2=polybutadiene with maleic anhydride added with ene, it shows good physical properties in terms of adhesiveness and heat resistance, but as mentioned above, it has poor adhesive properties. However, it was still insufficient.

An object of the present invention is to provide a curable resin composition that can be used to produce non-tacky prepregs, powders, pellets for molding, etc., which greatly improves the workability of the conventional methods as described above.

[Means for solving problems]

Component A: a polyfunctional cyanate ester containing two or more cyanato groups in the molecule, a prepolymer of the cyanate ester, or a prepolymer of the cyanate ester and an amine (
A thermosetting resin composition containing a) as an essential component and optionally containing other thermosetting resins (BL).

Component B: a butadiene-vinyl aromatic compound copolymer containing a carboxyl group in the molecule, 50% or more of the butadiene units constituting the polymer chain are 1,2-bonds, and the melting point is 10°C or higher ( An epoxy resin-modified butadiene copolymer obtained by modifying c) with a polyfunctional epoxy resin (dl) and having a melting point of 10°C or higher and an epoxy equivalent of 300 to 8,000.

This is a curable resin composition containing the above components A and B.

The configuration of the present invention will be explained below.

The cyanate ester resin composition of component A of the present invention is:
It consists of a polyfunctional cyanate ester having a cyanato group, its prepolymer, etc. as essential components, and is a cyanato resin (Japanese Patent Publication No. 41-1928, No. 45-11712,
44-1222, DE-1, 190, 184, etc.),
Cyanate ester-maleimide resin, cyanate ester-maleimide-epoxy resin (Special Publication No. 54-30440
, 52-31279, tlsP-4, 110, 364
etc.), cyanate ester-epoxy resin (Special Publication No. 46-
41112) and others.

Here, preferred polyfunctional cyanate esters (component (a)) which are essential components of component A have the general formula <1>:
R(OCN), ・----1------・・-
(1) (m in the formula is an integer of 2 or more and usually 5 or less,
R is an aromatic organic group, and the cyanato group is bonded to the aromatic ring of the organic group. Specific examples include 1.3- or 1,4-dicyanatobenzene, 1.3.5-tricyanatobenzene, 1
．． 3-. 1.4-, L6-. 1.8-. 2.6-or 2
．． 7-dicyanatonaphthalene, 1.3.6-dicyanatonaphthalene, 4.4”-dicyanatobiphenyl, bis(4-cyanatophenyl)methane, 2.2-bis(4-
cyanatophenyl)propane, 2,2-bis(3,5-
dichloro-4-cyanatophenyl)propane, 2,2-
Bis(3,5-dibromo-4-cyanatophenyl)propane, bis(4-cyanatophenyl)ether, bis(
4-cyanatophenyl) thioether, bis(4-cyanatophenyl) sulfone, tris(4-cyanatophenyl) phosphite, tris(4-cyanatophenyl) phosphate, and halogenated polycarbonate oligomers containing terminal -011 groups. Cyanic acid ester obtained by reaction with cyanide (USP-4°026.913)
, cyanic acid esters obtained by the reaction of novolak and cyanogen halide (USP-4,022,755, USP-3,448.079). In addition to these, Tokuko Sho 41-1928, Sho 43-18468, Sho 44-4
791. 45-11712, 46-41112, 47-26853, JP-A-51-63149, tlsP
-3,553,244, 3,755,402, 3,
740.348, 3,595,900, 3,694
．． 410 and 4.116, 946, etc. may also be used.

It can also be obtained by polymerizing the above-mentioned polyfunctional cyanate ester in the presence or absence of a catalyst such as a mineral acid, a Lewis acid, a salt such as sodium carbonate or lithium chloride, or a phosphate ester such as tributylphosphine. It can be used as a prepolymer. These prepolymers are
Generally, the molecule has a sym-triazine ring formed by trimerization of the cyanide group in the cyanate ester.

Furthermore, the polyfunctional cyanate esters described above can also be used in the form of prepolymers with amines. Examples of amines that can be suitably used include meta- or para-phenylenediamine;
meta- or para-xylylene diamine, 1,4- or 1
．． 3-Cyclohexanediamine, hexahydroxylylenediamine, 4,4'-diaminobiphenyl, bis(4
-aminophenyl)methane, bis(4-aminophenyl)ether, bis(4-aminophenyl)sulfone, bis(4-amino-3-methylphenyl)methane, bis(
4-amino-3,5-dimethylphenyl)methane, bis(4-aminophenyl)cyclohexane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-
Amino-3-methylphenyl)propane, 2,2-bis(4-amino-3-chlorophenyl)propane, bis(
4-amino-3-chlorophenyl)methane, 2.2-bis(4-amino-3,5-dibromophenyl)propane, bis(4-aminophenyl)phenylmethane, 3.4
-diaminophenyl-4-aminophenylmethane, 1.
1-bis(4-aminophenyl)-1-phenylethane and the like.

The above-mentioned polyfunctional cyanate esters, prepolymers thereof, and prepolymers with amines can be used in the form of mixtures, and the number average molecular weight of the individual and mixtures is 300 to 6,000.
, preferably 1,500 or less, especially 300 to 1,
A range of 000 is preferred.

Cyanate ester-maleimide resin (Special Publication No. 54-30
440, etc.), cyanate ester-maleimide-epoxy resin (Japanese Patent Publication No. 52-31279, etc.), and cyanate ester-epoxy resin (Japanese Patent Publication No. 46-41112). A suitable maleimide used as component (b)) has the general formula (2): (wherein, R8 is an aromatic or alicyclic organic group having a valence of 2 or more and usually a valence of 5 or less, XI and Xi are hydrogen, It is a halogen or an alkyl group, and n is usually an integer of 2 to 5. Maleimides represented by the above formula are produced by a method known per se, in which maleic anhydride and polyamines containing 2 to 5 amino groups are reacted to prepare maleamic acid, and then maleamic acid is cyclized by dehydration. be able to. The polyamines used are preferably aromatic polyamines in terms of the heat resistance of the final resin, but if flexibility and flexibility of the resin are desired, alicyclic amines may be used alone or in combination. good. Further, it is desirable that the polyamines be primary amines from the viewpoint of reactivity, but secondary amines can also be used.

Suitable amines include amines used in the form of a prepolymer with component A described above, melamines having a sym-triazine ring, and melamines prepared by reacting aniline with formalin and linking benzene rings with methylene bonds. Polyamines, etc.

In addition, the epoxy resin in component (bl) can be any resin used as a laminate, a molding material, a paint, etc. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, etc. Epoxy resin,
Phenol novolac type epoxy resin, Talesol novolac type epoxy resin, halogenated bisphenol A
These include type epoxy resins, halogenated phenol novolac type epoxy resins, polyglycol type epoxy resins, alicyclic epoxy resins, etc., and these can be used alone or as a mixture of two or more types.

The epoxy resin-modified butadiene copolymer of component B of the present invention has a carboxyl group in the molecule, 50% or more of the butadiene units constituting the polymer chain are 1.2 = bonds, and the melting point is 10°C or higher. A butadiene-vinyl aromatic compound copolymer (hereinafter referred to as component (c1)) modified with a polyfunctional epoxy resin (hereinafter referred to as component (dl)) has a melting point of 10°C or higher and an epoxy equivalent of 300 to 8. 0
00, an epoxy resin-modified butadiene copolymer.

Ingredients (c1 is butadiene and a vinyl aromatic compound,
Usually, the weight ratio is 80:20 to 10:90, preferably 70:30 to 20:80, and the 1.2-bonds in the butadiene units constituting the polymer chain are 50% or more, preferably 50% or more. A block or random copolymer having a melting point of 85% or more and having a carboxyl group introduced by treating it with a functional group-introducing reagent and having a melting point of 10°C or more,
Preferably the temperature is 20°C or higher.

Here, as the vinyl aromatic compound, styrene, α-
Methylstyrene, vinyltoluene, chlorostyrene, P
-Ethylstyrene, P-methoxystyrene, divinylbenzene, etc. are exemplified.

The polymerization of component (c1) can be carried out using a known anionic polymerization method or anionic living polymerization method (Japanese Patent Publication No. 17485/1985, USP
3,488,332, etc.), but in the former case, in the presence of a catalyst such as sodium or organic lithium, butadiene and a vinyl aromatic compound are
In the anionic polymerization method in which the reaction is carried out at a temperature of
Since it is difficult to set the above conditions, the latter is preferable.

The reaction between the latter butadiene and a vinyl aromatic compound is
In the anionic living polymerization method carried out at a temperature of 0°C or lower, the amount of 1,2-bonds in the butadiene unit can be easily increased to 80% or more, or 85 to 95% depending on the conditions. Random or block copolymers can be easily obtained by adding the group compounds simultaneously or sequentially, and the molecular weight of the copolymers can be adjusted very easily.

Introduction of a carboxyl group is a method in which the polymerization reaction solution obtained by the method is treated with carbon dioxide, and then treated with water and methanol to introduce a carboxyl group at the end of the polymer chain;
The polymerization reaction solution obtained by this method is treated with ethylene oxide, then treated with water and methanol to introduce hydroxyl groups at the ends of the polymer chains, and then some or all of the hydroxyl groups are replaced with maleic anhydride, phthalic anhydride, A method of half-esterifying using a dibasic acid anhydride such as 4-methylhexahydrophthalic anhydride, dodecylsuccinic anhydride, trimellitic anhydride, etc. Furthermore, the polymerization reaction solution obtained by the above method is immediately mixed with water and methanol. A butadiene-vinyl aromatic compound copolymer having no functional groups can be obtained by treating this with a copolymer of maleic anhydride, methyl A butadiene-vinyl aromatic compound copolymer in which an acid anhydride group was introduced into a part of the polymer chain was obtained by adding ene to an ethylene-α/β-dicarboxy compound such as maleic anhydride. A method may be used in which a part or all of the nucleic acid anhydride group is half-esterified with a hydroxyl group-containing compound such as butyl alcohol, ethyl cellosolve, allyl alcohol, 2-hydroxyethyl methacrylate, ethylene glycol, or phenol to open the ring.

The component obtained by the above method (butadiene component in c1 is 80%
If it exceeds 10% by weight, the compatibility between component B and component A obtained by modification with component (d) will deteriorate, and if it is less than 10% by weight, the heat resistance of the cured product will deteriorate, which is not preferable. or,
If the content of 1,2-bond units in the butadiene units is less than 50%, the heat resistance of the cured product deteriorates, which is not preferable. Furthermore, the number average molecular weight of component (c) is 500 to 20,000.
In particular, 1,000 to 5,000 is preferable, and the melting point is 10℃
As mentioned above, the melting point is preferably 20°C or higher, and if the melting point is lower than 10°C, the composition becomes sticky and workability deteriorates.

The polyfunctional epoxy resin of component (d) used in the preparation of component B is not particularly limited as long as it has a trifunctional or more functional epoxy group in the molecule. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, phenol novolac type epoxy resin, Talesol novolac type epoxy resin, urethane modified epoxy resin, glycidyl ester type epoxy resin, polyglyco - type epoxy resins, alicyclic epoxy resins, glycidylamine type epoxy resins, isocyanuric acid type epoxy resins, halogenated bisphenol A type epoxy resins, halogenated phenol novolac type epoxy resins, etc., which may be used alone or in combination. Used as a mixture of the above. In order to obtain component B, which can easily produce non-tacky prepregs, powders, pellets for molding, etc., in the epoxy resin,
Particularly preferred are those having a melting point of 10°C or higher.

Component B is produced by reacting the above-described component (c) and component (dl) by a known method (see JP-A-57-5717, etc.).

The reaction ratio of component (d) to component (c) is
), the epoxy equivalent of component B obtained is 300 to 8,000, preferably 500 to 4, assuming 1.8 to 20 equivalents of epoxy groups in component (dl)
,000. If the epoxy equivalent is less than 300, the electrical properties will deteriorate;
If it exceeds 0, adhesiveness will be insufficient, which is not preferable.

Further, the melting point of component B is 10°C or higher, preferably 20°C or higher; a melting point of lower than 10°C is not preferable because the resulting composition becomes sticky.

The above cyanate ester resin composition of component A and component B
The curable resin composition of the present invention is prepared by mixing or preliminarily reacting with an epoxy-modified butadiene copolymer.

Preparation methods include mixing under heating without a solvent; heating preliminary reaction without a solvent; mixing as a solution of a solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, etc.; Either a method of pre-reacting by mixing as a solution of the solvent or a method of mixing a pre-reacted solution of the solvent is possible.

The composition ratio of component A and component B is not particularly limited, but the weight ratio is usually 9515 to 30/70, preferably 90/10.
~40/60, especially in the range of 80/20 to 50150.

The curable resin composition of the present invention is cured as it is, but in order to accelerate the curing reaction such as the crosslinking reaction between component A and component B, a known compound that is a curing catalyst for component A is used.

Examples of these include amines, imidazoles, organic metal salts, inorganic metal salts, and organic peroxides.

Among these catalysts, organic metal salts alone and combination systems of organic metal salts and organic peroxides are suitable. Examples of organic metal salts include zinc naphthenate, lead stearate, lead naphthenate, zinc octylate, and oleic acid. These include tin acid, tin octylate, dibutyltin malate, manganese naphthenate, cobalt naphthenate, iron acetylacetone, manganese acetylacetone, etc., and organic peroxides include benzoyl peroxide, 2
．． Diacyl peroxides such as 4-dichlorobenzoyl peroxide, octanoyl peroxide, and lauroyl peroxide; di-t-butyl peroxide; 2.
Dialkyl peroxides such as 5-dimethyl-2,5-di(1-butylperoxy)hexyne-3 and dicumyl peroxide; t-butyl perbenzoate, t-
Peroxy esters such as butyl peracetate, di-t-butyl perphthalate, and 2,5-dimethyl-2,5-di(benzoylperoxy)hexane; Ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; Di-L-butyl hydroperoxide, cumene hydroperoxide,
Hydroperoxides such as α-phenylethyl hydroperoxide and cyclohexenyl hydroperoxide i 1,1-bis(t-butylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-
Examples include peroxyketals such as 3,3,5-trimethylcyclohexane, and the amount of these curing catalysts used is sufficient within the range of catalyst amounts in a general sense, for example, based on the total resin composition. 10% by weight or less, especially 51i
Used in amounts below %.

The novel curable resin composition of the present invention has the above two components as essential components, and also contains natural or synthetic resins for modifying component A, a fibrous reinforcing material, a filler,
Known substances such as dyes, pigments, thickeners, lubricants, coupling agents, and flame retardants can be added.

Such other resins for modification include curable resins such as polyester resins, phenolic resins, acrylic resins, urethane resins, silicone resins, and alkyd resins; polybutadiene, butadiene-acrylonitrile copolymers, polychloroprene, and butadiene. - Non-crosslinked (unvulcanized) rubbers such as styrene copolymers, polyisoprene, butyl rubber, natural rubber, and their low molecular weight liquid rubbers; thermoplastic polyurethane resins, polyvinyl acecool resins,
Vinyl acetate resin and other thermoplastic resins with reactive groups and their low molecular weight products with a molecular weight of several thousand or less; engineering plastics such as polycarbonate, thermoplastic polyester, polyester carbonate, polyphenylene ether, polysulfone, polyether sulfone, polyarylate, etc. Low molecular weight oligomers with a molecular weight of several thousand or less; polyethylene, polypropylene, polybutene,
Low molecular weight oligomers of polyolefins such as poly-4-methylpentene-1 with molecular weights of several thousand or less; polytetrafluoroethylene, tetrafluoroethylene-propylene copolymers, perfluoroethylene-propylene copolymers, vinylidene fluoride, etc. Examples include low molecular weight oligomer resins having a molecular weight of several thousand or less of the fluororesin.

Fillers include, for example, silica powder such as fused silica and crystalline silica, boron nitride powder, and boron silicate powder for applications with low dielectric constant and low dielectric loss tangent, and for applications with high thermal conductivity such as boron nitride powder and boron silicate powder. In addition to the above-mentioned fillers, examples include alumina, magnesium oxide (magnesia), and other suitable fillers include wollastonite, mica, calcium carbonate, talc, and other inorganic fillers. These inorganic fillers may be used as they are or may be surface-treated with a silane coupling agent, a titanate coupling agent, etc., and are used as particles or fibrous fillers. In addition, as reinforcing base materials, cloth-like reinforcing base materials made of various weaves such as roving, chopped strand mat, continuous mat, cloth, roving cloth, and surfacing mat are particularly suitable for use in laminated products. Examples include woven fabrics, mixed fiber fabrics, nonwoven fabrics made of fibers such as quartz, glass, carbon, wholly aromatic polyamide, and fluororesin, as well as paper and porous fabrics. Furthermore, it is a preferable embodiment to improve the processability, flexibility, etc. of the molded article by replacing a part of the above-mentioned inorganic fillers with organic fillers. Examples include powders of engineering plastics such as polycarbonate, thermoplastic polyester, polyester carbonate, polyarylate, and polyphenylene ether; powders of polyolefins such as polyethylene, polypropylene, and poly-4-methyl-1-pentene; and polytetrafluoroethylene. Examples include powders of fluororesins such as polytetrafluoroethylene-propylene copolymer, half-00 ethylene-propylene copolymer, and the like.

The curing conditions for the curable resin composition of the present invention by the above method are usually a temperature of 100 to 300°C, preferably 160 to 300°C.
At 240℃, under no pressure for paint, 0.1~ for molding.
1000 kg/d, preferably 3-500 kg
Pressurize with /-. Here, the molding time is selected in the range of 30 seconds to 30 hours, and in the case of a relatively short time of 30 seconds to 100 minutes or when a low temperature is used, the molding time is selected in the range of 30 seconds to 30 hours. It is preferable that the molded article be sufficiently hardened by curing.

〔Example〕

Examples of the present invention will be described below. In addition, the amounts added in the examples are heavy unless otherwise specified! ! It is a standard.

2.2-His(4-cyanatophenyl)propane (hereinafter referred to as rBPA-CNJ) alone and BPA-CN and bis(4-maleimidophenyl)methane (hereinafter referred to as rBMIJ)
Preliminary reaction products (Here 1 to 85) were prepared. Table A shows the reaction conditions and number average molecular weight (hereinafter referred to as "stone").

Table A: Butadiene-vinyl aromatic compound copolymer (=CP-BS), which is made by copolymerizing butadiene (・Bu) and styrene (・St) or α-methylstyrene (・αSt) by anionic living polymerization method, is used as a raw material. Carboxyl group-containing butadiene copolymers (c1 to C7) were prepared using the following methods.

01-C3 reacts CP-BS with carbon dioxide (
Those having a carboxyl group at the end obtained by post-treatment method (■), 04 to C6, are reacted with CP-BS and ethylene oxide to introduce a hydroxyl group at the end, and then treated with 4-methylhexahydrophthalic anhydride or anhydride. (c)-7 has a terminal carboxyl group that has been halfesterized using maleic acid (post-treatment method ①). It has a carboxyl group in the molecule which has been halfesterized and ring-opened using methacrylate (post-treatment method ①).

These properties are shown in Table B''.

Table B'' 01 to C7 prepared above were reacted with an epoxy resin to prepare an epoxy resin-modified butadiene copolymer (Bl to B?) as component B.

Table B2 also shows a commercially available carboxyl group-containing butadiene homopolymer (NISSO-PBC-1) in place of C1.
,000, viscosity 75 Boise/45℃, 1,2-bond in butadiene unit 90.5%, Mn 1310, acid value 64.2, manufactured by Nippon Soda, hereinafter referred to as rcE4J). A comparative sample obtained in the same manner as the preparation was
Indicated as I.

These reaction conditions and properties are shown in Table B.

Table B □ Examples 1 to 9 and Comparative Examples 1 to 9 Component A produced in Reference Example A above, Component B produced in Reference Example B, and comparative sample CBI, or other components were mixed,
A pre-reaction was carried out as appropriate, diluted with a solvent to obtain a solution with a concentration of 50%, and a catalyst was added to the solution to form a varnish.

The composition ratio, mixing conditions, etc. are shown in Table 1.

The descriptions in the columns of other additive components, notes (cars), and catalyst in Table 1 are as follows.

[Other additive ingredients column]

[Remarks column] [Catalyst column] Table 1 These varnishes were impregnated into a 0.2 m thick plain weave E glass woven fabric and heated and dried to prepare B-stage prepregs. Electrolytic copper foil with a thickness of 35 P was stacked on both sides of the stacked sheets, and lamination molding was performed at a temperature of 180°C and a pressure of 50 kg/cd for 120 minutes.
Post-curing was performed at 00° C. for 24 hours to obtain a copper-clad laminate. In addition, Example 7 has a structure in which 6 sheets of prepreg obtained in the same manner using a glass non-woven fabric with a thickness of 0.2 mm are layered with 1 sheet of the glass woven fabric prepreg prepared above on both sides, and the above-mentioned copper foil is further layered on both sides. As described above, lamination molding and post-curing were carried out.

Lamination molding conditions and properties of the obtained copper-clad laminates are shown in Table 2.

Table 2 Example 10 5100 parts of A and B7 were preheated and MIB was added under reduced pressure.
After mixing 50 parts of the epoxy resin-modified butadiene copolymer obtained by distilling off K, 0.1 part of iron acetylacetone and 2 parts of di-t-butyl peroxide as a catalyst, 150 parts of wollastonite was added. , 100
The pellets were kneaded using an extrusion kneader at ~110°C. This pellet had good blocking resistance. This pellet was heated at a temperature of 170℃ and a pressure of 300kg/c.
d for 3 minutes, and the molded product was further post-cured in an oven at 200° C. for 30 minutes to obtain a good molded product.

This molded product has a glass transition temperature of 200°C and a bending strength of 8.
4 kg/wJ (20℃), 4.2 kg/J
(170°C), and the heating loss was 0.8% (220°C, after 100 hours).

[Operation and effects of the invention]

As is clear from the detailed description of the invention, reference examples, working examples, comparative examples, etc., the curable resin composition of the present invention has good solubility in general-purpose low-boiling point solvents, and can be used as a solution or as a solution. The working environment, drying and other workability will be extremely good. In addition, when used for laminated boards etc., B-sta
A prepreg that is easy to convert into GE and has virtually no stickiness is obtained, and has excellent handling and workability, and the resulting cured product has excellent electrical properties (especially low dielectric constant and low dielectric loss tangent), adhesiveness, and heat resistance. It is understood that the composition has extremely good properties such as properties and is suitable for practical use in such applications.

Claims (1)

[Claims] Component A: a polyfunctional cyanate ester containing two or more cyanato groups in the molecule, a prepolymer of the cyanate ester, or a prepolymer of the cyanate ester and an amine (
A thermosetting resin composition comprising a) as an essential component and, if necessary, another thermosetting resin (b). Component B: a butadiene-vinyl aromatic compound copolymer containing a carboxyl group in the molecule, 50% or more of the butadiene units constituting the polymer chain are 1,2-bonds, and the melting point is 10°C or higher ( An epoxy resin-modified butadiene copolymer obtained by modifying c) with a polyfunctional epoxy resin (d) and having a melting point of 10°C or higher and an epoxy equivalent of 300 to 8,000. A curable resin composition containing the above components A and B.