JPH01156367A - Resin composition for composite material - Google Patents

Abstract

PURPOSE:To obtain a resin compsn. for composite materials which has an excellent processability and can impart excellent heat resistance, water resistance and mechanical properties to the composite materials, by blending a mixture of three specific bismaleimides with an alkenylphenol (ether). CONSTITUTION:A mixture of three bismaleimides, i.e., N,N'-diphenyl methanebismaleimide, N,N'-tolylenebismaleimide and N,N'-trimethylhexamethyl ene-bismaleimide, is blended with an alkenylphenol and/or its ether to prepare a resin compsn. The mixing ratio of the three bismaleimides is determined in such a way as to provide a mixture having an m.p. of 70-120 deg.C. This is determined as desired in the range of the amt. of N,N'-tolylenebismaleimide of 10-45wt.% and in the range of the amt. of N,N'- trimethylhexamethylenbismaleimide of 5-35wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel resin composition for composite materials which has excellent processability and provides excellent heat resistance, water resistance and mechanical properties.

[Prior art and problems to be solved by the invention] Conventionally, various resin compositions have been used as matrix resins for composite materials. In the field of thermosetting resins,
In addition to the excellent mechanical properties of the resin itself, especially its strength and elongation,
Epoxy resins have been widely used because they have good adhesion to reinforcing materials and are excellent in developing strength of reinforcing materials.

In recent years, there has been a strong demand for higher performance of composite materials, particularly improvements in heat resistance, water resistance, and impact resistance. In order to meet this demand, thermosetting resin compositions containing, for example, polyimide and γμ phenol A/and/or γμ phenol ether y are being considered as matrix resins (Japanese Patent Publication No. 55 -69242).

In particular, from the viewpoint of heat resistance of composite materials, aromatic bismaleimides (for example, N, N'-diphenylmethane bismaleimide), alkenesium phenol! Resin compositions consisting of and/or alkenylphenol ethers are attracting attention. This cured resin has excellent heat resistance and mechanical properties (strength, elongation). However, aromatic bismaleimide has a high melting point and requires a long time to mix at high temperatures (140 to 160°C), and in order to improve heat resistance, the bismaleimide component
A~K2μphenol and/or C,Aμ per 1 equivalent
When mixed with kenylphenol ether μm equivalent or less,
In particular, when used in composite materials where the mixture has a high viscosity or softening point, there are problems in processability, such as difficulty in normal solvent-free impregnation.

The present inventors have arrived at the present invention as a result of intensive studies to develop a resin composition for composite materials that has excellent processability and has high heat resistance, water resistance, mechanical properties, and impact resistance. .

[Means for solving problems]

That is, the gist of the present invention is to provide a mixture of six types of bismaleimides: N,N'-diphenylmetal)-bismaleimide, N,N'-tolylene bismaleimide, and N,N'-)listylhexamethylene bismaleimide; A resin composition for composite materials containing alkenylphenol and/or alkenylphenol ether.

N, N'-diphenylmethane bismaleimide, N, N'-tolylene bismaleimide, N used in the present invention
, N'-) listylhexamethylene bismaleimide is the corresponding diamino compound, namely 4°4'- or 46'-diaminodiphenylmethane and a mixture of two isomers, 2.4-11.2.6- Alternatively, either he-4-diaminotoluene or a mixture of two or more isomers, and either 2.2°4- or 2,4.4-) listyl hexamethylene diamine or two isomers. It can be produced by a known method of reacting a mixture of and maleic anhydride, followed by dehydration and cyclization. The operation of mixing the three types of bismaleimides may be carried out during the bismaleimide production process, after each bismaleimide production, or when mixing with alkenylphenol and/or alkenylphenol. The mixing ratio of each bismaleimide is
The melting temperature of the mixture is determined to be 70-120°C. That is, 40-80% by weight of N,N'-diphenylmethane bismaleimide, 10-45% by weight of N,N'-tolylene bismaleimide, and 5-35% by weight of N,N'-trimethylhexamethylene bismaleimide. ′
It can be determined as desired. Even if the mixing ratio of each component exceeds or is less than a specific ratio, the melting temperature exceeds 120° C., which is unfavorable for handling.

In the present invention, alkenylphenol-μ usually has an isomer of alkenylphenol ether of 180 to 2
It is obtained by heat treatment at a high temperature of 50° C. to cause Claisen transition.

Alkenylphenol ethers are synthesized according to a known method in which a pheno-μ compound and an alkenyl halide are reacted in the presence of an alkali metal hydroxide and a catalyst. Examples of phenolic compounds used in the synthesis of the above alkenylphenol or alkenylphenol ether include monohydric phenols such as phenol, cresol, xylenol, p-tert-butylphenol, and 4,4'-dihydroxydiphenylpropane. (Bisphenol A), 4.4'-dihydroxydipheniμmethane (Bispheno-A/F), 4.
4'-dihydroquine diphenyl sulfone (bispheno-
/l/S), 46'-dihydroxydiphenylpropane, 4.4'-dihyde 10xydiphenylene A/, 4
．． 4'-dihydroxy-2,2'-! , 'methyl diphenyl ether, 4.4'-dihydroxydiphenyl sulfite, 4.4'-dihydroxydiphenyl ketone, 1
Examples include polyhydric phenols such as hydroquinone, resorcinol, catechol, phenolic resin, and cresol resin.

Another method for producing alkenylphenol is to react 0-allylphenol with aldehydes or ketones.

Furthermore, natural products such as eugenol, isoeugenol μ, eugenol methyl ether, or derivatives thereof can also be used.

These alkenylphenols and alkenylphenol ethers can be used alone or in a mixture of two or more.

In the composition of the present invention, a mixture of three types of bismaleimides, N,N'-diphenyμmethane bismaleimide, N,N'-tolylene bismaleimide, N,N'-)listi p-hexamethylene bismaleimide, and an alkenylphenol. The composition ratio with alkenylphenol ether and/or alkenylphenol ether is 1 equivalent of the bismaleimide mixture.
Phenol yv and/or Aμ phenol
can be selected in the range of [105 to 10 equivalents, preferably α1 to 1 equivalent.

If the amount of the latter is small, the cured product will be brittle and the viscosity of the resin composition will be high, which is unfavorable for processing. On the other hand, if the latter compounding ratio is more than 1 equivalent, unreacted allyl groups remain in the cured product, which tends to reduce heat resistance. Here, the bismaleimide mixture may be reacted with alkenylphenol and/or alkenylpheno-μ ether in advance to an extent that gelation does not occur.

Although the resin composition of the present invention can be easily cured by heat, a catalyst may be added for the purpose of imparting desired properties to the cured product or adjusting the thermosetting properties of the resin.

As a polymerization catalyst, imidazoles, tertiary amine M,
Examples include ionic catalysts such as quaternary ammonium salts and boron trifluoride amine salts, and radical polymerization initiators such as known organic peroxides, hydroperoxides, and azoisopetite (IJA). The amount of catalyst added may be determined depending on the purpose, but from the viewpoint of stability of the resin composition, it is preferably 0.2 to 3% by weight based on the total resin solid components.

If desired, other known thermosetting resins, such as epoxy resins, unsaturated polyester resins, phenolic resins, silicone resins, triazine resins, other allyl resins, etc., and thermoplastic resins, such as polyethersulfone, polyester, polyester, etc. Etheretherketone, polyetherimide, etc. may be added.

The resin composition for composite materials of the present invention can be mixed with various fillers and reinforcing agents at a relatively low temperature using a mixer, kneader, roll, etc., and can be easily prepared into a casting or molding material.

When impregnating a reinforcing material with the resin composition of the present invention, the composition is pre-reacted at a temperature of 50 to 150°C to produce a prepolymer. Can be impregnated in molten state. Of course, it may be dissolved and impregnated in a solvent such as dimethyl ethyl ketone, methylene chloride, chloroform, or tetrahydrofuran, if desired.

As reinforcing agents, glass fiber, returned fiber, boron fiber,
Chopped fibers made of inorganic fibers such as silicon carbide fibers, organic fibers such as holy p-phenylene terephthalimide, poly-p-benzamide, and polyamide hydrazide;
Yarns, tapes, sheets, knitted fabrics, mats, compositions, asbestos, mica, talc, etc., and mixtures of two or more of these may be used. Further, depending on the purpose, flow control agents such as fine silicon oxide powder, pigments, dyes, stabilizers, plasticizers, lubricants, tar, asphalt, etc. can be used alone or in combination with other reinforcing materials. The content of the reinforcing material is preferably 5 to 80 volumes.

〔Example〕

Hereinafter, the invention will be explained in more detail using examples.

The "viscosity" of the uncured resin was measured at 50°C using a Dynamic Mechanical Spectrum meter manufactured by Rheomerics.

The "glass transition point (Tf)" of the cured product was measured by the TMA method using a TMS-2 model attached to a PerkinElmer D80-2.The "hot water resistance" of the composite material was 0°. After standing in water for 14 days at 177°C according to ASTM D-2344.
The determination was made by measuring the interlaminar shear strength (LSa) at 232°C.

“Impact resistance” is defined as 3
A 4.9 kg weight with a 1/2 inch radius nose attached to the center of the table is fixed on a table with an inch hole, and a weight of 4.9 kg is dropped.
After applying an impact of 1500 t'bin per inch of plate thickness, the strength was determined by subjecting the plate to a compression test.

All composite data are based on a fiber content of 60% by volume.

Examples 1 to 3 0,0'-diallylbispheno-μA (abbreviated as ABPA) and N,N'-diphenylmethane bismaleimide (49,jJt) synthesized by the method described in Japanese Patent Publication No. 55-39242. Using a mixture of N,N'-tolylene bismaleimide (354% by weight) and N,N'-trimethylhexamethylene bismaleimide (112% by weight), the equivalent ratio of ABPA and bismaleimide mixture was determined. The mixtures were mixed and stirred at 110° C. for 10 minutes in the proportions shown in Table 1, and pre-reacted to obtain a prepolymer. This prepolymer was sandwiched between glass plates to a predetermined thickness, cured at 182°C for 6 hours, and then post-cured at 243°C for 6 hours to obtain a cured resin plate.

Further, this prepolymer was stretched into a thin film on release paper at a VC of 80° C., and carbon fibers (Byrofy/L/T-3 manufactured by Mitsubishi Rayon Co., Ltd.) were wound around a drum to impregnate the prepolymer. Next, by cutting open the unidirectional blipreg (thread size 145
97 m", resin content 65% by weight). This prepreg was laminated at "0°, 116, and still [+45°70°
/-45°790°] 4s pseudo-isotropically stacked at 182°C
The composite material was cured for 6 hours at 243° C. and then post-cured for 6 hours at 243°C. Various tests were conducted on uncured resins, cured resins, and composite materials, and the results are shown in Table 1.

Comparative Examples 1-2 A resin plate was obtained in the same manner as in Example 1 except that only N,N'-diphenylmethane bismaleimide was used as the bismaleimide, and the mixing temperature was 150°C. Since the composite material could not be melted and impregnated under the same conditions as in Example 1, it was obtained by dissolving it in tetofhydrofuran to make a 50% solution and impregnating it. The various test results are shown in Table 1.

Examples 4-5 The mixing proportions of bismaleimide were N, N'-s) phenylmethane bismaleimide (ss weight t%), N, N'-tolylene bismaleimide (213ii%), N.

N'-trimethylhexamethylene bismaleimide (15
% by weight), and a resin plate and a composite material were obtained in the same manner as in Example 1 except for the following. Various test results are shown in Table IK.

From the above results, it can be seen that the resin composition for composite materials of the present invention has a low viscosity and is excellent in handleability and processability, and the cured composite material has excellent heat resistance and mechanical properties such as puffiness.

〔effect〕

The resin composition of the present invention has excellent processability, and the cured resin products and composite materials have excellent heat resistance, impact resistance, and mechanical properties, and are particularly suitable for casting, impregnating, and laminating molding materials. Useful as a heat-resistant material for aerospace applications.

Claims (1)

[Claims] 1, N,N'-diphenylmethane bismaleimide, N,
A resin composition for a composite material, comprising a mixture of three types of bismaleimides, N'-tolylene bismaleimide and N,N'-trimethylhexamethylene bismaleimide, and alkenylphenol and/or alkenylphenol ether. 2. The mixture of bismaleimides is 40-80% by weight of N,N'-diphenylmethane bismaleimide, 10-45% by weight of N,N'-tolylene bismaleimide, and 5-35% by weight of N,N'-trimethylhexamethylene bismaleimide. % of the composition according to claim 1. 3. 0 alkenylphenol and/or alkenylphenol ether per equivalent of bismaleimide mixture
．． The composition according to claim 1, characterized in that the composition contains 0.05 to 10 equivalents.