JPH0319257B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an intermediate material for composite materials that provides excellent heat resistance, water resistance and mechanical properties.

[Prior art]

Conventionally, various resin compositions have been used as matrices for composite materials, but especially in the field of thermosetting resins, in addition to the excellent mechanical properties of the resin itself (particularly strength and elongation), Epoxy resins have been widely used because they have good adhesive properties and the strength development of reinforcing materials is superior to other thermosetting resins. In recent years, there has been a strong demand for higher performance of composite materials, especially improvements in heat resistance, water resistance, and impact resistance. These pre-reactants are being considered. As a result, although the rigidity of the resin increased and the heat resistance and water resistance of the composite material improved, there were problems with a decrease in elongation and a decrease in impact resistance.

[Purpose of the invention]

The present inventors have arrived at the present invention as a result of intensive studies aimed at developing an intermediate material for composite materials that has high heat resistance, water resistance, and excellent impact resistance.

[Structure of the invention]

The present invention relates to polyfunctional maleimide () and polyfunctional cyanate ester or oligomer thereof ().
mixture of () or pre-reactant of () and () (A)
100 parts by weight, 5 to 100 parts by weight of epoxy compound (B) and general formula (In the formula, Ar represents a phenylene group, R ₁ represents a divalent aliphatic group, and R ₂ represents a divalent aromatic group or aliphatic group)
This is an intermediate material for a composite material in which a reinforcing material is impregnated with a resin composition consisting of 5 to 50 parts by weight of a polyester compound (C) represented by:

Substituent in polyester compound (C) of formula (1)
The phenylene group for Ar may be any o-phenylene group, m-phenylene group, or p-phenylene group, and the divalent aliphatic group for R ₁ may be a straight C2-C6 aliphatic group. A chain or branched aliphatic group is preferred, and examples include the following groups. Groups -(CH ₂ -) ₂ , -(CH ₂ -) ₃ , -CH ₂ -CH(CH ₃ )
−, CH−C ₂ H ₅ , −(CH ₂ −) ₄ , −CH ₂ −CH
(CH ₃ )−CH ₂ −, —(CH ₂ —) ₅ , —(CH ₂ —) ₃ CH
( _CH3 )−,−( _CH2− )CH( _CH3 ) _−CH2 −,−( _CH2
--) ₂ CH (C ₂ H ₅ ) --, --CH-C (CH ₃ ) ₂ --CH ₂ --, etc.
Examples of the divalent aromatic group for R ₂ include a phenylene group, and examples of the divalent aliphatic group include the same groups as R ₁ .

Polyfunctional maleimide () used in the present invention
is a compound having two or more maleimide groups, and has the general formula In addition to bismaleimide represented by the formula (in which R ₃ represents a divalent aromatic group or aliphatic group), it also includes prepolymers obtained from these bismaleimides and diamines. Bismaleimide of formula (2) can be produced by a known method of preparing bismaleimide acid by reacting maleic anhydride with a diamine, and then cyclodehydrating it. As the diamine, aromatic diamines are preferred from the viewpoint of heat resistance, but aliphatic amines may be used alone or in combination if it is desired to impart functions such as flexibility. Examples of diamines include m-phenylenediamine, p-phenylenediamine 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone,
4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, etc. are used.

The polyfunctional cyanate ester () used in the present invention is an organic compound having two or more cyanate ester groups and an oligomer thereof, and has the general formula R ₄ -(0-C≡N) _o (3) ( In the formula, n is an integer of 2 to 5, and R ₄ represents an aromatic organic residue. Examples of polyfunctional cyanate esters include 1,3- or 1,4-dicyanatobenzene, 4,4-dicyanatobiphenyl, bis(4-cyanatophenyl)methane, and 2,2-bis( 4-cyanatophenyl)ethane, 2,2-bis(4-cyanatophenyl)propane, bis(4-cyanatophenyl)sulfone, etc. are used. The polyfunctional cyanate ester described above can be used in the form of a triazine oligomer obtained by trimerizing cyanate, or in the form of a prepolymer obtained by reaction with an amine. and those used for metamorphosis.

In the present invention, as component A, a mixture of the polyfunctional maleimide () and a polyfunctional cyanate ester or its oligomer (), or a mixture obtained by pre-reacting () with () in the absence or presence of a catalyst, is used. Preliminary reactants are appropriately selected and used depending on the purpose.

The epoxy compound (B) used in the present invention may be any known epoxy resin, such as the following compounds. Polyglycidyl ethers of diphenylolalkanes such as diphenylopropane, diphenyloethane, and diphenylomethane; polyglycidyl ethers of polyhydric phenols such as novolac, cresol, and resol; cyclohexane, cyclopentadiene, dicyclopentadiene, etc. Epoxy resins produced by epoxidation of alicyclic compounds, such as (3,4-epoxy-6-methyl-cyclohexane)-methyl ester of 3,4-epoxy-6-methyl-cyclohexane-carboxylic acid, ethylene glycol, glycerin poly(epoxyalkyl)ethers of aliphatic polyoxy compounds such as, epoxyalkyl esters of carboxylic acids such as glycidyl esters of aromatic or aliphatic carboxylic acids, etc. Also, for example, U.S. Patent Nos. 3390037, 2970983, and
It may be a preliminary reaction product of an epoxy resin and a curing agent as described in each specification of No. 3067170,
It may also be a simple mixture. These may be used alone or in combination of two or more. Suitable epoxy compounds include, for example, diglycidyl ether of bisphenol A or diglycidyl ether of bisphenol F, or pre-reacted products of these epoxy compounds and diaminodiphenylsulfone at an epoxy group/NH group ratio of 4/1. Can be mentioned.

Polyester compound of formula (1) used in the present invention
(C) needs to have a softening point of 100°C or lower, preferably 70°C or lower. If the softening point exceeds 100℃, polyfunctional maleimide,
The compatibility with the polyfunctional cyanate ester and the epoxy compound deteriorates, making it difficult to obtain a uniform composition. This polyester compound has a number average molecular weight of 500 to 10,000, preferably 500 to 3,000, and an acid value of 20 to 3,000.
150, preferably 40 to 100. If the number average molecular weight is less than 500, the viscosity decreases, and if it exceeds 10,000, it is not suitable because it lacks workability in mixing with other components. The polyester compound used in the present invention can be produced by a general method used in the production of polyesters with other terminal carboxylic acids. After reacting with excess alcohol until the acid value becomes 20 or less,
A method in which a polyhydric carboxylic acid for end-capping, such as trimellitic anhydride, is reacted is preferred because a high acid value type polyester resin can be easily synthesized.

The polyhydric carboxylic acids and polyhydric alcohols used in the production of the polyester resin are those used in the production of conventional polyester resins, and examples of the polyhydric carboxylic acids include phthalic anhydride, isophthalic acid, and terephthalic acid. or lower alkyl esters thereof, aromatic polyhydric carboxylic acids such as tetrachlorophthalic anhydride, tetrabromophthalic anhydride, trimellitic acid, trimellitic anhydride, and pyromellitic anhydride, with terephthalic acid being preferred.

In addition to the above-mentioned aromatic polycarboxylic acids, the polycarboxylic acids for end-capping include, for example, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, hexic anhydride, 3,6-endomethylene-Δ ⁴ -anhydride Phthalic acid, maleic anhydride, tetrahydromaleic anhydride, fumaric acid, itaconic acid, succinic acid,
Aliphatic polycarboxylic acids such as succinic anhydride, adipic acid, azelaic acid, sebacic acid, and methylcyclohexcentric carboxylic acid are used. Trimellitic acid and trimellitic anhydride are preferred.

Examples of polyhydric alcohols include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol,
Neopentyl glycol, triethylene glycol, glycerin, trimethylolethane, trimethylolpropane, trishydroxymethylaminomethane, pentaerythritol, dipentaerythritol, etc. are used. Ethylene glycol and neopentyl glycol are preferred.

The resin composition used in the present invention has an A component of 100%
5 to 100 parts by weight of component B and 5 parts by weight of component C
It is necessary to set the composition ratio to 50 parts by weight. B
If the amount of the epoxy compound used is less than 5 parts by weight, the adhesion to the substrate will be poor, and if it exceeds 100 parts by weight, satisfactory heat resistance will not be obtained. Furthermore, if the amount of the polyester compound used as component C is less than 5 parts by weight, sufficient impact resistance will not be exhibited, and if it exceeds 50 parts by weight, heat resistance and solvent resistance will be significantly reduced. The ratio of ()/() in component A is preferably 5-15/95-85. If the amount of polyfunctional maleimide () is more than 15, hot water resistance will improve, but a high curing temperature will be required and impact resistance will decrease. On the other hand, if it is lower than 5, although the impact resistance improves, the hot water resistance decreases, which is not preferable.

A catalyst may be added to the resin composition used in the present invention for the purpose of imparting desired properties to the cured resin product or adjusting the thermosetting properties of the resin.
Examples of the catalyst include, in addition to latent curing catalysts such as boron trifluoride amine complex compounds, triethylenediamine, 1,8-diazabicyclo(5.4.0)undecene)N,N-dimethylbenzylamine, N-methylmorpholine, Tertiary amines such as tri-n-butylamine, organic peroxides such as dicumyl peroxide, benzoyl peroxide, t-butyl hydroperoxide, zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, etc. Examples include organic acid metal salts. The amount of catalyst to be used 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.

As the reinforcing material for the intermediate material for composite materials of the present invention,
In addition to inorganic fibers such as glass fiber, carbon fiber, boron fiber, and silicon carbide fiber, chop-shaped, yarn-shaped, and tape-shaped products are made of organic fibers such as poly-p-phenylene terephthalamide, poly-p-benzamide, and polyamide hydrazide. , sheet, knitted, pine, paper, asbestos, mica,
Talc and the like and mixtures of two or more thereof are used. Depending on the application, flow control agents such as silicon oxide fine powder, pigments, dyes, stabilizers, plasticizers, lubricants, etc.
Tar, asphalt, and the like can also be used alone or in combination with other reinforcing agents.

When impregnating a reinforcing agent with a resin composition, the resin composition is pre-reacted at a temperature of 50 to 120°C to produce a prepolymer, and this prepolymer is dissolved in a solvent such as methyl ethyl ketone and impregnated into the reinforcing material. is preferred. The content of the reinforcing material in the intermediate material for composite material is preferably 0.5 to 80% by volume. Further, thermosetting resins and thermoplastic resins other than epoxy resins can be used in combination.

Example 1 Bis(4-maleimidophenyl)methane, 2,
2-bis(4-cyanatophenyl)propane,
The following table shows Epikote 807 (manufactured by Schiel Kagaku Co., Ltd.) with an epoxy equivalent weight of 172, a polyester (a) with a softening point of 30°C, consisting of terephthalic acid as the acid component, neopentyl glycol as the glycol component, and terminal-capped with trimellitic anhydride. The mixture was mixed in the proportions shown, and 1.25 parts of silicon oxide fine powder, AEROSIL 380 (manufactured by Nippon Aerosil Co., Ltd.) and 0.2 parts of dicumyl peroxide as a curing catalyst were added, and a preliminary reaction was carried out at 70° C. for 30 minutes to obtain a prepolymer. This prepolymer was sandwiched between glass plates to a predetermined thickness and heated to 180°C.
After curing for 2 hours, a resin plate was obtained. In addition, this prepolymer was dissolved in methyl ethyl ketone, impregnated with carbon fiber (Pyrofil T-3 manufactured by Mitsubishi Rayon Co., Ltd.), wound around a drum, dried, and then cut open to create a unidirectional prepreg (thread size 145
g/m ² , resin content 33% by weight). This prepreg was laminated to [0°] ₁₆ , and also [+45°/0°/-
45°/+90°) _4S was laminated in a pseudo-isotropic manner and cured at 180°C for 2 hours to obtain a composite material. Various tests were then conducted on resins and composite materials. The results are shown in the table below. The glass transition point (Tg) in the table is
This is the tan δ MAX temperature measured by a Dynamik mechanical spectrometer manufactured by Rheometrics Inc. The hot water resistance of the composite material was determined after a 16-layer laminate composite was left in water at 71°C for 14 days.
Judgment was made by performing a compression test in the 0° direction at 121°C in accordance with ASTM D695. In addition, the impact resistance
In accordance with NASA RP1092, a board with dimensions of 4 x 6 x 0.25 inches was fixed on a table with a 3 x 5 inch hole, and a 1/2 inch radius nose was attached in the center.
Dropping a kg weight, 1500lbin per inch of plate thickness
It was determined by applying an impact to the plate and then performing a compression test. All composite data are based on 60% fiber content.

Example 2 Instead of polyester (a), terephthalic acid was used as the acid component, and ethylene glycol and neopentyl glycol were used in a ratio of 1:1 (by weight) as the glycol component.
A resin plate and a composite material were obtained in the same manner as in Example 1 except that polyester (b) consisting of a mixture and having a softening point of 25° C. whose ends were sealed with trimellitic anhydride was used. The results of various tests are shown in the table below.

Example 3 A resin plate and a composite material were obtained in the same manner as in Example 1 except that Epikote 828 (manufactured by Ciel Chemical Co., Ltd.) having an epoxy equivalent of 184 to 194 was used as the epoxy resin.
The test results are shown in the table below.

Example 4, Comparative Examples 1 and 2 A resin plate and a composite material were obtained in the same manner as in Example 1 except that the amount of polyester (a) used was changed. The test results are shown in the table below.

Example 5, Comparative Examples 3 and 4 A resin plate and a composite material were obtained in the same manner as in Example 1 except that the amount of Epicote 807 used was changed. The test results are shown in the table below.

Examples 6 and 7 Resin plates and composites were produced in the same manner as in Example 1 except that the amounts of bis(4-maleimidophenyl)methane and 2,2-bis(4-cyanatophenyl)propane were changed. I got the material. The test results are shown in the table below.

Claims (1)

[Claims] 1. 100 parts by weight of a mixture of polyfunctional maleimide () and polyfunctional cyanate ester or its oligomer () or a preliminary reaction product of () and () (A), 5 parts by weight of an epoxy compound (B) ~100 parts by weight and general formula (In the formula, Ar represents a phenylene group, R ₁ represents a divalent aliphatic group, and R ₂ represents a divalent aromatic group or aliphatic group)
An intermediate material for a composite material in which a reinforcing material is impregnated with a resin composition consisting of 5 to 50 parts by weight of a polyester compound (C) represented by: 2. The intermediate material for a composite material according to claim 1, wherein the polyfunctional maleimide () is bismaleimide of diaminodiphenylmethane. 3. The intermediate material for a composite material according to claim 1, wherein the polyfunctional cyanate ester () is dicyanate of bisphenol A. 4. The epoxy compound (B) is diglycidyl ether of bisphenol A or diglycidyl ether of bisphenol F, or a preliminary reaction product of these epoxy compounds and diaminodiphenylsulfone at an epoxy group/NH group ratio of 4/1. An intermediate material for a composite material according to claim 1, characterized in that: 5 The polyester compound (C) is a reaction product of terephthalic acid and neopentyl glycol whose ends are sealed with trimellitic anhydride, and the softening temperature is
The intermediate material for a composite material according to claim 1, characterized in that the intermediate material is 100°C or less and has an average molecular weight of 500 to 10,000. 6. The intermediate material for a composite material according to claim 1, which contains 0.2 to 3% by weight of silicon oxide fine powder. 7 The weight ratio of ()/() in component A is 5 to
15/95-85, the intermediate material for composite material according to claim 1. 8. The intermediate material for a composite material according to claim 1, which contains 0.2 to 3% by weight of boron trifluoride monoethylamine complex, dicumyl peroxide and/or zinc octylate as a catalyst. .