JPH0319256B2 - - 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 having high heat resistance, water resistance, and excellent impact resistance.

[Structure of the invention]

The present invention provides 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 is a phenylene group and R ₁ is a divalent aliphatic group.) Polyester compound (C)5
This is an intermediate material for composite materials in which a reinforcing material is impregnated with ~50 parts by weight of a resin composition.

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. Group ( _-CH2 ) _-2 , ( _-CH2 ) _-3 , _-CH2 -CH( _CH3 )
−, CH−C ₂ H ₅ , (−CH ₂ )− ₄ , −CH ₂ −CH
( _CH3 ) _−CH2− , ( _−CH2 ) ₋₅ , ( _−CH2 ) ₋₃ CH
(CH ₃ )−, (−CH ₂ )− ₂ CH(CH ₃ )−CH ₂ −, (−CH ₂
) _-2CH ( _C2H5 )-, _-CH2 - _C ( _CH3 ) ₂ - _CH2- , etc.

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 ₂ represents a divalent aromatic group or aliphatic group), it also includes prepolymers obtained from these bismaleimides and diamines. The bismaleimide of formula (2) can be produced by a known method of preparing bismaleamic 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 ₃ (-0-C≡N) _o (3) ( In the formula, n is an integer of 2 to 5, and R ₃ 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) is preferably a compound whose acid component is mainly terephthalic acid and whose glycol component is mainly neopentyl glycol or ethylene glycol. The polyester compound used in the present invention must have a softening point of 100°C or lower, preferably 70°C or lower. If the softening point exceeds 100°C, the compatibility with polyfunctional maleimide, polyfunctional cyanate ester, and epoxy compound deteriorates, making it difficult to obtain a uniform composition. This polyester compound has a number average molecular weight of 500~
10,000, particularly preferably 500 to 3,000.
If it 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 other linear polyesters.

The resin composition used in the present invention has an A component of 100%
5 to 100 parts by weight of component B, 5 to 100 parts by weight of component C
It is necessary to set the composition ratio to 50 parts by weight. If the amount of the epoxy compound used as component B 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. Also C
If the amount of the component polyester compound used is less than 5 parts by weight, sufficient impact resistance will not be exhibited.
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, heat resistance will improve, but a high curing temperature will be required, and impact resistance will decrease, and if it is less than 5, impact resistance will improve, but
This is not preferred because hot water resistance decreases.

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 catalysts include latent curing catalysts such as boron trifluoride amine complexes, triethylenediamine, 1,8-diazabicyclo(5,4,0)undecene, N,N-dimethylbenzylamine, N-
Tertiary amines such as methylmorpholine and tri-n-butylamine, organic peroxides such as dicumyl peroxide, benzoyl peroxide, and t-butyl hydroperoxide, zinc octylate, tin octylate,
Examples include organic acid metal salts such as zinc naphthenate and cobalt naphthenate. 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, as well as mixtures of two or more thereof, are used.

Depending on the purpose, flow control agents such as fine silicon oxide powder, pigments, dyes, stabilizers, plasticizers, lubricants, tar, asphalt, etc. may also be used alone or in combination with other reinforcing materials.

When impregnating a reinforcing material 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 methylene ethyl ketone and impregnated into the reinforcing material. It is preferable to let 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,
Epikote 807 (manufactured by Schiel Kagaku Co., Ltd.) having an epoxy equivalent of 172 and polyester (a) with a softening point of 25°C consisting of terephthalic acid as an acid component and neopentyl glycol as a glycol component are mixed in the proportions shown in the table below, and a fine amount of silicon oxide is added. 1.25 parts of 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 is sandwiched between glass plates to a predetermined thickness.
A resin plate was obtained by curing at 180°C for 2 hours. In addition, this prepolymer is 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 density).
145 g/m ² , resin content 33% by weight). This prepreg was laminated to [0°] ₁₆ , and also [+45°/
0゜/-45゜/+90゜) _4S pseudo-isotropically stacked and heated at 180℃
The mixture was cured 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 the tan δ MAX temperature measured with a Dynamik mechanical spectrometer manufactured by Rheometrics. 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 calculated based on a fiber content of 60%.

Example 2 Polyester (b) with a softening point of 20°C consisting of terephthalic acid as the acid component and a 1:1 (by weight) mixture of ethylene glycol and neopentyl glycol as the glycol component was used instead of polyester (a), and the other conditions were as follows. A resin plate and a composite material were obtained in the same manner as in Example 1. 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 composite materials were prepared 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. Obtained. The test results are shown in the table below.

Claims (1)

[Scope of Claims] 1. 100 parts by weight of a mixture of polyfunctional maleimide () and polyfunctional cyanate ester or its oligomer () or a preliminary reaction product (A) of () and (), epoxy compound (B) 5-100 parts by weight and general formula (In the formula, Ar is a phenylene group and R ₁ is a divalent aliphatic group) Polyester compound (C)5
An intermediate material for composite materials in which a reinforcing material is impregnated with ~50 parts by weight of a resin composition. 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 from terephthalic acid and neopentyl glycol, has a softening temperature of 100°C or less, and has an average molecular weight of 500~
10,000, the intermediate material for composite material according to claim 1. 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. .