JPH05170953A - Prepreg for carbon fiber-reinforced resin composite material - Google Patents

Abstract

PURPOSE:To provide the subject prepreg using a specific silane coupling agent- treated carbon fibers as reinforcing material, capable of giving highly tough carbon fiber-reinforced resin composite materials with excellent thermal and mechanical properties. CONSTITUTION:The objective prepreg suitable for the structural materials for aircraft, made up of (A) as reinforcing material, carbon fibers treated with a silane coupling agent consisting of an aminosilane, epoxysilane and/or vinylsilane and (B) as matrix resin, a composition composed mainly of (1) a blend of polyfunctional maleimide and polyfunctional cyanic ester or (2) a preliminary reaction product therefrom, with its surface provided with (C) pref. fibrous thermoplastic resin form such as of engineering plastic.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prepreg for a carbon fiber reinforced resin composite material, which is capable of forming a carbon fiber reinforced resin composite material having excellent thermal and mechanical properties and excellent toughness.

[0002]

2. Description of the Related Art Carbon fiber reinforced composite materials have a specific strength
It is widely used for various purposes, centering on sports goods, by taking advantage of its excellent specific elasticity. At present, epoxy resins are the mainstream as the matrix resin, but epoxy resins do not have sufficient heat resistance, so carbon fiber reinforced epoxy resin composite materials are increasing in heat resistance, mainly for applications in aerospace products. Can not be fully satisfied. On the other hand, polyimide, which is known as a heat-resistant resin, has excellent heat resistance, but has a problem in terms of molding processability, so that its practical use as a matrix resin has been delayed.

Under these circumstances, a mixture or pre-reacted product of a polyfunctional maleimide resin and a polyfunctional cyanate ester having an excellent balance between heat resistance and moldability has attracted attention as a matrix resin for carbon fiber composite materials. There is. However, this resin suffers from poor toughness, which limits its application considerably. As a method for improving this drawback, a method of blending a rubber component or a thermoplastic resin, a method of copolymerizing another monomer, etc. have been proposed,
Although the physical properties such as heat resistance are greatly deteriorated, the toughness is not sufficiently improved, and even if the fracture toughness of the resin alone is improved, the toughness of the carbon fiber composite material is not sufficiently improved. It was In addition, a method of inserting a kind of adhesive layer or an impact absorbing layer called an interleaf between the layers has been proposed, but it has drawbacks that the fiber content cannot be increased and the handleability is poor. It has not been done.

Further, for example, in Japanese Unexamined Patent Publication No. 1-110537 and the like, regarding a prepreg for a carbon fiber reinforced resin composite material, spherical fine particles are localized from the surface of the prepreg to a depth within 30% of the thickness of the prepreg. Although it has been proposed to improve the toughness of the composite material, this method has a problem that the toughness of the composite material as a whole is not sufficiently improved even if the amount of fine particles added is increased.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a carbon fiber without impairing the heat resistance which is a characteristic of a mixture of a polyfunctional maleimide used as a matrix resin and a polyfunctional cyanate ester or a preliminary reaction product thereof. An object of the present invention is to provide a prepreg for a carbon fiber reinforced resin composite material, which can impart excellent toughness to the reinforced resin composite material.

[0006]

Means for Solving the Problems The present inventors have made a matrix a composition containing carbon fiber as a reinforcing material and a mixture of a polyfunctional maleimide and a polyfunctional cyanate ester or a pre-reactant thereof as a main component. As a resin, and as a result of various studies on prepregs for carbon fiber reinforced resin composite materials in which a thermoplastic resin molded product is present on the surface, as the carbon fibers constituting this prepreg, use those treated with a specific silane coupling agent. As a result, they have found that the toughness of the composite material molded with the prepreg can be remarkably enhanced, and have completed the present invention.

That is, the present invention uses carbon fiber as a reinforcing material, a composition containing a mixture of a polyfunctional maleimide and a polyfunctional cyanate ester or a pre-react thereof as a main component as a matrix resin, and the surface of the composition. In a prepreg for a carbon fiber reinforced resin composite material in which a thermoplastic resin molded article is present, the carbon fiber in the prepreg is treated with at least one silane coupling agent selected from aminosilane, epoxysilane and vinylsilane. Is a prepreg for a carbon fiber reinforced resin composite material.

The present invention will be described in detail. A feature of the present invention is that a composition containing a mixture of a polyfunctional maleimide and a polyfunctional cyanate ester as a matrix resin or a pre-reactant thereof as a main component, carbon fiber as a reinforcing material, and a thermoplastic resin molded product. When configuring a prepreg with
As the carbon fiber, the carbon fiber treated with at least one silane coupling agent selected from aminosilane, epoxysilane and vinylsilane is used. By using the carbon fiber treated with the specific silane coupling agent as the prepreg raw material in this manner, the carbon fiber composite material molded from the prepreg is significantly improved in toughness without impairing the heat resistance and other characteristics of the matrix resin. Since the untreated carbon fiber is used as it is, no matter how high the toughness of the resin composition and the thermoplastic resin are combined, the toughness of the composite material can be sufficiently exhibited. I can't.

In the present invention, the term "carbon fiber" means both carbon fiber and graphite fiber. This carbon fiber is obtained by carbonizing a fibrous material such as polyacrylonitrile or pitch, which is usually referred to as "precursor", or by heating it to a graphite temperature. A carbon fiber having a high strength and a high elongation of 1.7% or more is preferably used. Further, it is suitable to introduce functional groups such as hydroxyl groups and carboxylic acid groups on the surface by electrolytically oxidizing or ozone oxidizing the surface of the carbon fiber.

The silane coupling agent used in the present invention is as follows. Aminosilane is γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyl-methyl-diethoxysilane,
γ-ureidopropyltriethoxysilane, γ- (2-
Aminoethyl) aminopropyltrimethoxysilane and the like, and the epoxysilane is γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane and the like, and the vinylsilane includes vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, vinyltriacetoxysilane and the like.
A compound in which the functional group is an amino group is particularly preferable. A partial condensate of these silane coupling agents can also be used.

As the method for treating the carbon fiber with the silane coupling agent, any treatment method which is usually used may be used, but a method of treating the carbon fiber by passing it through a low concentration solution of the silane coupling agent is particularly preferable. In this case, when the concentration of the silane coupling agent in the solution is high, the focusing of the carbon fibers becomes too strong, and it becomes difficult to obtain a uniform composite material,
It is important to use a low-concentration solution because the toughness of the composite material will decrease. The solution concentration is preferably 2.0% by weight or less, particularly preferably 0.001 to 2.0% by weight. As the solvent when preparing the low-concentration solution of the silane coupling agent, any solvent may be used as long as it dissolves the silane coupling agent and is substantially inert to the silane coupling agent. Considering the drying process after treatment,
High boiling organic solvents are not preferred. As a solvent when using an aminosilane coupling agent as a silane coupling agent, a lower alcohol such as ethyl alcohol,
A mixed solvent of lower alcohol and water, a water / alcohol mixed solvent containing an acid component such as acetic acid, and the like are particularly preferable. The carbon fibers treated with these silane coupling agent solutions are used after removing volatile components such as solvents by air drying and / or heat treatment.

The matrix resin used in the present invention is mainly composed of a mixture of a polyfunctional maleimide and a polyfunctional cyanate ester or a pre-reaction product thereof. The polyfunctional cyanate ester as used herein also includes its oligomer. This matrix resin is a resin composition containing a mixture of a polyfunctional maleimide and a polyfunctional cyanate ester or a pre-reacted product thereof in an amount of 30% by weight, preferably 40% by weight or more.

The polyfunctional maleimide is a compound having two or more maleimide groups and has the general formula

[0014]

[Chemical 1]

In addition to the bismaleimide represented by the formula (wherein X represents a divalent aromatic or aliphatic group), a prepolymer obtained from these bismaleimide and diamine is included. The bismaleimide of the chemical formula 1 can be produced by a known method of reacting maleic anhydride with a diamine to prepare a bismaleamic acid, and then subjecting it to a dehydration cyclization.

Aromatic diamines are preferable as the diamines from the viewpoint of heat resistance, but aliphatic amines may be used alone or in combination when it is desired to impart functions such as flexibility. Examples of the diamine include m-phenylenediamine, p-phenylenediamine, 4,4′-diaminodiphenylsulfone, 3,3′diaminodiphenylsulfone, 4,4′-diaminodiphenylmethane, 4,
4'-diaminodiphenyl ether or the like is used.

The polyfunctional cyanate ester or oligomer thereof 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:

[0018]

[Chemical 2]

(Wherein n represents an integer of 2 to 5 and Y represents an aromatic organic residue). As the polyfunctional cyanate ester, 1,3- or 1,4-dicyanatobenzene, 4,4-dicyanatobiphenyl, bis (4-cyanatophenyl) methane, 2,2-bis (4-cyanate) Tophenyl) ethane, 2,2-bis (4
-Cyanatophenyl) propane, bis (4-cyanate)
Tophenyl) sulfone or the like is used. This polyfunctional cyanate ester can be used not only in the form of a triazine oligomer obtained by trimerization of cyanate, but also in the form of a prepolymer formed by reaction with an amine. As the amine used for that purpose, the above-mentioned polyfunctional maleimides can be used. Those used for the synthesis and modification of

Preliminary reaction products obtained by preliminarily reacting the above-mentioned polyfunctional maleimide and polyfunctional cyanate ester or its oligomer alone or in the absence of a catalyst or under a catalyst are appropriately selected and used according to the intended use. The weight ratio of the polyfunctional maleimide to the polyfunctional cyanate ester or its oligomer is preferably 5 to 15:95 to 85. If the proportion of the polyfunctional maleimide is more than 15, the hot water resistance is improved but a high curing temperature is required, and the impact resistance tends to decrease. If it is less than 5, the impact resistance is improved but the hot water resistance is It is not preferable because it tends to decrease.

It is preferable to mix an epoxy compound in order to improve the adhesion of the reinforcing material to the carbon fiber or to add a polyester compound for the purpose of improving the toughness.

The epoxy compound may be a known epoxy compound, and examples thereof include the following compounds.
Polyphenylidyl diphenyl ethers such as diphenyl propane, diphenyl ethane and diphenyl methane; polyglycidyl ethers of polyvalent phenols such as novolac, cresol and resole; cyclohexane and cyclopenta Epoxy compounds produced by epoxidation of alicyclic compounds such as diene and dicyclopentadiene, for example, (3,4-epoxy-6-methyl-cyclohexane) of 3,4-epoxy-6-methyl-cyclohexane-carboxylic acid. ) -Methyl ester and the like; poly (epoxyalkyl) ether of aliphatic polyoxy compound such as ethylene glycol and glycerin; epoxyalkyl ester of carboxylic acid such as glycidyl ester of aromatic or aliphatic carboxylic acid. Further, it may be a pre-reactant of an epoxy compound and a curing agent as described in, for example, U.S. Pat. Nos. 3,339,0037, 2,970,983 and 3,067,170, and is a simple mixture. Good.

These epoxy compounds 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 a pre-reaction product of those epoxy compounds with diaminodiphenyl sulfone at an epoxy group / NH group ratio of 4/1. Is mentioned.

The polyester compound has a general formula

[0025]

[Chemical 3]

Or

[0027]

[Chemical 4]

A compound represented by the formula (wherein Ar represents a phenylene group, R ₁ represents a divalent aliphatic group, and R ₂ represents a divalent aromatic group or an aliphatic group) is preferable, and an acid component is particularly preferable. A compound in which terephthalic acid is mainly used and a glycol component is mainly neopentyl glycol or ethylene glycol is preferable. Furthermore, the softening point of the polyester compound is 1
It is important that the temperature is 00 ° C. or lower, and 70 ° C. or lower is preferable.

When the softening point is higher than 100 ° C., the compatibility with the polyfunctional maleimides, the polyfunctional cyanates and the epoxy compound becomes poor, and it becomes difficult to obtain a uniform composition. The polyester compound preferably has a number average molecular weight of 500 to 10,000, particularly 500 to 3,000. If it is less than 500, the viscosity is lowered, 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 mixing ratio of the epoxy compound and the polyester compound is 5 to 100 parts by weight of the epoxy compound and 100 parts by weight of the mixture of the polyfunctional bismaleimide and the polyfunctional cyanate ester or the oligomer thereof or the pre-reactant thereof. The amount of the compound is preferably 5 to 50 parts by weight. When the amount of the epoxy compound used is less than 5 parts by weight, the adhesion to the reinforcing material is poor, and when it exceeds 100 parts by weight, satisfactory heat resistance cannot be obtained. Further, when the amount of the polyester compound used is less than 5 parts by weight, sufficient impact resistance is not exhibited, and when it exceeds 50 parts by weight, heat resistance and solvent resistance are remarkably lowered.

A catalyst may be added for the purpose of imparting desired properties to the matrix resin cured product or controlling the thermosetting property of the resin. Examples of the catalyst include a staying curing catalyst such as a boron trifluoride amine complex compound, triethylenediamine, and 1,8-diazabicyclo (5.4.0).
Tertiary amines such as undecene, N, N-dimethylbenzylamine, N-methylmorpholine, tri-n-butylamine; dicumylperoxide, benzoyl peroxide, t
-Butylhydroperoxide and other organic peroxides; and organic acid metal salts such as zinc octylate, tin octylate, zinc naphthenate and cobalt naphthenate. The amount of the catalyst used may be determined according to the purpose, but from the viewpoint of the stability of the resin composition, it is preferably 0.2 to 3% by weight based on the total solid components of the resin.

Further, reactive elastomer such as carboxyl group terminated butadiene / acrylonitrile copolymer, carboxyl group terminated polybutadiene, acryloyloxy group terminated butadiene / acrylonitrile copolymer, epoxy resin, unsaturated polyester resin, phenol resin, silicone Thermosetting resin such as resin, polyethylene sulfone,
You may add thermoplastic resins, such as a polyether imide, a polyether ether ketone, a thermoplastic polyimide, polyester, polyamide, and a polyamide imide. The addition amount of the thermoplastic resin is preferably 30% by weight or less.
When it is used in an amount of more than 30% by weight, the viscosity of the system becomes too high, which not only causes impregnation failure at the time of making a prepreg but also causes deterioration of tack characteristics and drape characteristics of the prepreg.

It is also possible to mix a small amount of inorganic fine particles such as fine powder silica. The ratio between the silane-coupling-treated carbon fiber and the matrix resin can be appropriately set according to the purpose, but a weight ratio of carbon fiber / matrix resin = 60/40 to 75/25 is particularly preferable.

In the present invention, on the surface of the prepreg,
A thermoplastic resin molding is present. This thermoplastic resin may be applied to one side or both sides of the prepreg. As the thermoplastic resin of the thermoplastic resin molded product, polyamide, polyester, polyimide, polyetherimide,
Examples include so-called engineering plastics such as polyamide-imide, polybenzimidazole, polyaryl sulfone, and polyether ether ketone, super engineering plastics, or polymer alloys. Those having a functional group capable of reacting with the matrix resin such as an amino group, a phenolic hydroxyl group, an amide group, an allyl group, and a vinyl group in the molecular chain are preferable. Are engineering plastics, super engineering plastics or polymer alloys introduced into the molecular chain. Further, in particular, polyimide and polyethylene imide which are soluble in the polyfunctional maleimide resin in the course of curing and heating are preferable.

The form of the thermoplastic resin molding is as follows:
A fibrous form, a particulate form, a film form and the like can be mentioned. As the particulate thermoplastic resin molded product, those commercially available as the above-mentioned engineering plastics and fine particles of super-engineering plastics can be used, and those not commercially available as the fine particles can be prepared by a known method such as grinding. It is made into fine particles before use. Particle size is 1
00 μm or less is preferable, and more preferably 2 μm to 60
μm.

The fibrous thermoplastic resin molded article can be obtained by a known method such as melt spinning or solution spinning of the above engineering plastic or super engineering plastic. As the form of fiber,
There is no particular limitation, such as a long fiber monofilament, a bundle thereof, or a short fiber. The diameter of the fiber is preferably 100 μm or less, and 50 μm
Is particularly preferable. Further, the structure of the woven fabric made of the fibrous thermoplastic resin is not particularly limited, such as plain weave, satin weave, and woven weave. Nonwoven fabrics can also be used. Woven fabric has a fiber weight per unit area (weight per unit area) of 1 to 2
It is preferably 5 g / m ² .

Among these thermoplastic resins, the use of the fibrous thermoplastic resin has the following advantages: (1) A small amount of the thermoplastic resin can be arranged on the prepreg surface. (2) It is easy to control the tack level of the prepreg. (3) It is not necessary to handle high-viscosity substances, and the conventional prepreg manufacturing process can be used as it is. (4) Quality control is easy. And the like, and is particularly preferable. Further, the thermoplastic resin molded products in these forms may be used in combination, for example, by arranging fibrous and particulate ones on the surface of the prepreg.

The thermoplastic resin molded product is preferably used in a ratio of 0.5 to 40 parts by weight with respect to 100 parts by weight of the matrix resin. If it is less than 0.5 parts by weight, a sufficient toughness improving effect is not obtained, and if it exceeds 40 parts by weight, the toughness improving effect not only reaches a ceiling but also the surface tack is reduced, or depending on the type of resin used, Heat resistance and solvent resistance may be significantly reduced, which is not preferable.

Next, carbon fiber reinforced in which a thermoplastic resin molded product is present on one or both surfaces of the silane coupling agent-treated carbon fiber, the polyfunctional maleimide resin, and the thermoplastic resin molded product. A method for producing a prepreg for a resin composite material will be described. In this method, for example, (1) a resin film is formed by dispersing a particulate thermoplastic resin in a polyfunctional maleimide-based resin, and the aligned silane coupling agent-treated carbon fibers are formed using this resin film. A method in which an impregnation treatment is carried out by sandwiching from above and below so that the particulate thermoplastic resin is filtered by the carbon fibers so as to be substantially present on the surface of the prepreg in the impregnation process. A method in which a prepreg is prepared from a functional maleimide resin by an ordinary method, and a particulate thermoplastic resin or a fibrous (short fibrous) thermoplastic resin is sprinkled on the surface to integrate the prepreg, or a fibrous (long (A fibrous) thermoplastic resin is aligned and integrated, or a woven thermoplastic resin is placed on the surface and integrated.
(3) A method of producing a resin film by impregnating aligned fibrous thermoplastic resins with a polyfunctional maleimide resin and a silane coupling-treated carbon fiber, but is not particularly limited.

A preferred embodiment of the present invention is as follows. 1. The matrix resin is a mixture of a polyfunctional maleimide and a polyfunctional cyanate ester or a pre-reactant thereof,
The prepreg for a carbon fiber reinforced resin composite material according to claim 1, which is a mixture of an epoxy compound and / or a polyester compound. 2. The prepreg for a carbon fiber reinforced resin composite material according to claim 1, wherein the carbon fiber is treated with an aminosilane coupling agent solution having a concentration of 0.001 to 2.0% by weight.

[0041]

The present invention will be described in more detail with reference to the following examples. Examples 1 to 3 gamma-aminopropyltriethoxysilane in water / ethano-
Solution (water / ethanol = 1/9 weight ratio) mixed solvent to prepare a 0.05% by weight solution. A high-strength medium-elastic carbon fiber (MR-50K manufactured by Mitsubishi Rayon Co., tensile strength 5600 MPa, elastic modulus 300 GPa) was dipped in this solution,
Let it pass. After air-drying, it was dried with hot air at 130 ° C. for 2 minutes and wound up. Further, it was dried at 80 ° C. for 12 hours under a reduced pressure of 15 mmHg. The treated carbon fiber showed the same appearance as the untreated one.

Bis (4-maleimidophenyl) methane,
Softening point consisting of 2,2-bis (4-cyanatophenyl) propane, Epicor 807 (produced by Yuka Shell Co., Ltd.) having an epoxy equivalent of 172, terephthalic acid as an acid component, and neopentyl glycol as a glycol component. 25 ° C. polyester was mixed in the ratio shown in Table 1, and further silicon oxide fine powder Aerosil 380 (manufactured by Nippon Aerosil Co., Ltd.) 1.25.
Parts and 0.2 parts of dicumylperoxide as a curing catalyst, and mixed at 70 ° C. for 30 minutes to prepare a resin composition. A unidirectional prepreg was produced from this resin composition and the carbon fiber subjected to the above treatment by a hot melt method.
The carbon fiber areal weight of the prepreg was 145 g / m ² , and the resin content was 31% by weight. On the other hand, Matrimid 5
Polyimide powder of 218 (manufactured by Ciba-Geigy) was used in methylene chloride / methanol (methylene chloride / methanol =).
A solution dissolved in 90/10 weight ratio) and adjusted to a predetermined viscosity (1000 poise) was extruded into a fibrous form and dried to obtain a 200-denier / 52-filament fibrous thermoplastic resin.

On both sides of the prepreg, the fibrous Mat
rimid 5218, fiber weight per side 11g
/ M ² , with a winding interval of 2 mm, winded in the same direction as the carbon fiber, and then a fibrous Matrimid 521
Most of No. 8 was lightly embedded in the prepreg to produce the prepreg of the present invention. From this prepreg, cut a small piece of a predetermined size, and set the direction of the carbon fiber to + 45 °, 0 °,
4 layers x 4 times at -45 ° and 90 °, then 90
After laminating 4 layers x 4 times at °, -45 °, 0 ° + 45 °,
Autoclave molding (Curing conditions: 180 ° C, 2 hours, 5
Then, a test piece for measuring the compressive strength after impact was prepared. Using this test piece, SACMA (Suppliers of A
dvanced Composites Materials Association) Recommend
1500 in-1 according to ed Method SRM2-88
The compressive strength after b / in impact was measured. The results are shown in Table 1.
Shown in.

Comparative Example 1 A test piece was prepared and evaluated in the same manner as in Example 1 except that high-strength medium-elastic carbon fiber not treated with γ-aminopropyltriethoxysilane was used. The results are shown in Table 1.

[0045]

[Table 1]

Examples 4-6 Polyester instead of fibrous Matrimid 5218
Terimide fiber (100 denier / 32 filament)
A test piece was prepared and evaluated in the same manner as in Example 1 except that the weight per unit surface was 11 g / m ² at a 1 mm interval. The results are shown in Table 2. Example 7 A prepreg of the present invention was obtained by placing a plain weave fabric having a fiber basis weight of 20 g / m ² made of fibrous Matrimid 5218 in place of the fibrous Matrimid 5218 of Example 1 on one side of a prepreg and pressing it lightly. A test piece was prepared and evaluated in the same manner as in Example 1 except for the above. The results are shown in Table 2.

Example 8 Aminosilane-treated carbon fiber was obtained in the same manner as in Example 1, while fine particles of Matrimid 5218 (particle size: 80 μm or less) were added to the resin composition prepared in Example 22.
% By weight, and mixed with a mixer at 80 ° C. to uniformly disperse the powder in the resin. Put this on release paper with a resin weight of 35
A g / m ² film was prepared, and the aminosilane-treated carbon fibers aligned with each other were sandwiched from above and below to prepare a prepreg by a hot melt method. The fine particles of Matrimid 5218 dispersed in the resin were filtered by carbon fibers so that they were substantially present on the surface of the prepreg, and the prepreg of the present invention was obtained. Using this prepreg, a test piece was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 2. Comparative Example 2 A test piece was prepared and evaluated in the same manner as in Example 8 except that carbon fiber not treated with aminosilane was used. The results are shown in Table 2.

[0048]

[Table 2]

Example 9 A test piece was prepared and evaluated in the same manner as in Example 1 except that γ-ureidopropyltriethoxysilane was used. The results are shown in Table 3. Example 10 3-glycidoxypropyl-methoxysilane was mixed with a solvent obtained by adding a small amount of acetic acid to water-ethanol (1/9 weight ratio) to prepare a 1.0% by weight solution. Test pieces were prepared and evaluated in the same manner as in Example 1 except that carbon fibers were treated with this solution. The results are shown in Table 3. Example 11 Vinyltriethoxysilane was added to acetone / water (50/1
(Weight ratio) was mixed with a solvent containing a small amount of acetic acid to prepare a 0.2 wt% solution. Test pieces were prepared and evaluated in the same manner as in Example 1 except that carbon fibers were treated with this solution. The results are shown in Table 3.

[0050]

[Table 3]

[0051]

The molded article obtained from the prepreg for carbon fiber reinforced resin composite material of the present invention, that is, the carbon fiber reinforced resin composite material, has excellent thermal properties of the matrix resin,
It has excellent toughness without impairing the mechanical properties. . Therefore, the prepreg for a carbon fiber reinforced resin composite material of the present invention is extremely useful as a prepreg capable of molding a composite material that can be suitably used as a structural material for aircraft.

Continuation of the front page (72) Inventor Takashi Tada 4-60, Sunadabashi, Higashi-ku, Nagoya City Mitsubishi Rayon Co., Ltd. Product Development Laboratory

Claims (2)

[Claims] 1. A matrix resin comprising carbon fiber as a reinforcing material and a composition containing a mixture of a polyfunctional maleimide and a polyfunctional cyanate ester or a pre-reactant thereof as a main component, as a matrix resin.
And in a prepreg for a carbon fiber reinforced resin composite material having a thermoplastic resin molded product on the surface, the carbon fiber is treated with at least one silane coupling agent selected from aminosilane, epoxysilane and vinylsilane. Prepreg for carbon fiber reinforced resin composite material characterized by: 2. The prepreg for a carbon fiber reinforced resin composite material according to claim 1, wherein the thermoplastic resin molding is fibrous.