JPH0892392A - Carbon fiber-reinforced thermosetting resin prepreg - Google Patents

Abstract

PURPOSE: To obtain carbon fiber-reinforced thermosetting resin prepreg in which carbon fibers treated with a specific compound is used as a reinforcing material, a thermosetting resin as a matrix resin and a thermoplastic resin is arranged on the surfaces, thus gives a carbon fiber-reinforced resin composite material of high heat resistance and high toughness. CONSTITUTION: Carbon fibers are soaked in 0.2% aqueous solution of a compound of the formula (m>=1; n 2>=1) which is prepared by reaction of an aliphatic amine of the formula: CH3 (CH2 )1 NH2 (1>=0) with ethylene oxide and passed through, then dried at 130 deg.C with hot air for 2 minutes. The carbon fibers are used as a reinforcing material, a thermosetting resin such as a maleimide resin, as a matrix to effect the formation process, as a fibrous thermoplastic resin such as polyimide resin are placed on the surfaces, to give this carbon fiber- reinforced thermosetting resin prepreg giving carbon fiber-reinforced thermosetting resin composite material of excellent toughness without damage to the heat resistance of the thermosetting resin as a matrix.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon fiber reinforced thermosetting resin prepreg capable of forming a tough carbon fiber reinforced resin composite material having excellent heat resistance.

[0002]

2. Description of the Related Art Carbon fiber reinforced composite materials are widely used for various purposes, mainly in sports equipment, by taking advantage of their characteristics such as excellent specific strength and specific elasticity. At present, epoxy resin is the mainstream as the matrix resin, but epoxy resin does not have sufficient heat resistance, so carbon fiber reinforced epoxy resin composite material is one of the heat-resistant materials that is increasing mainly in aerospace applications. It has become difficult to satisfy the demand sufficiently. As the heat resistant resin, thermosetting polyimide, bismaleimide, bismaleimide-
Triazine, cyanate resin, etc. are well known, but in general, the heat-resistant resin has a very brittle cured product, its composite material has poor toughness and impact resistance, and its use is considerably limited. There is.

In order to remedy this drawback, a method of blending a rubber component or a thermoplastic resin, a method of copolymerizing another monomer component, etc. have been proposed, but the physical properties such as heat resistance are largely deteriorated. There are problems that the toughness is not sufficiently improved, or that even if the fracture toughness of the resin alone is improved, the toughness of the composite material is not sufficiently improved. Further, from the idea of imparting toughness to the composite material as a whole, it is effective to selectively reinforce the layers of the laminate to suppress delamination at the time of impact, and a kind of adhesive layer called interleaf or Although a method of inserting an impact absorbing layer between the layers has been proposed, it has not been used generally because it has drawbacks such as a high content of reinforcing fibers and poor handleability as a prepreg. Further, a method of localizing rubber particles or high toughness thermoplastic resin fine particles on the surface of an epoxy resin prepreg has been proposed, but in some cases, the expected improvement in toughness cannot be obtained. In particular, when this method is applied to a prepreg or a composite material such as a heat-resistant resin system such as a maleimide resin or a polyimide resin, it is the fact that almost the expected sufficient toughness improving effect is not obtained.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a carbon fiber capable of imparting excellent toughness to a carbon fiber reinforced thermosetting resin composite material without impairing the heat resistance of the thermosetting resin as a matrix resin. An object is to provide a reinforced thermosetting resin prepreg.

[0005]

Means for Solving the Problems The present inventors have conducted various studies on carbon fiber reinforced thermosetting resin prepregs having thermoplastic resin moldings on the surface, and as a result, have identified specific compounds as carbon fibers constituting the prepregs. It was found that the toughness of the composite material molded with the prepreg can be remarkably enhanced by using the material treated with the above method, and the present invention was completed.

That is, according to the present invention, a carbon fiber-reinforced thermosetting resin prepreg having a carbon fiber as a reinforcing material, a thermosetting resin as a matrix resin, and a thermoplastic resin molding on the surface thereof is used as the carbon fiber. It is a carbon fiber reinforced thermosetting resin prepreg characterized by using carbon fiber treated with the compound represented by (1). CH ₃ (CH ₂ ) _l N (CH ₂ CH ₂ O) _m H (CH ₂ CH ₂ O) _n H (1) (where l ≧ 0, m ≧ l, n ≧ l)

A feature of the present invention is that when a prepreg is composed of a thermosetting resin composition as a matrix resin, carbon fiber as a reinforcing material, and a thermoplastic resin molding, the carbon fiber is represented by the general formula (1). The point is to use the one treated with the compound represented by. By using the carbon fiber treated with the specific compound as the prepreg raw material in this manner, it is possible to impart significantly improved toughness to the carbon fiber composite material molded from the prepreg without impairing the heat resistance and other properties of the matrix resin. Therefore, if untreated carbon fibers are used, no matter how high the toughness of the resin composition and the thermoplastic resin are combined, the toughness of the composite material cannot be sufficiently exhibited.

The term "carbon fiber" as used in the present invention 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. Above all, the tensile strength is 4500 MPa or more and the elongation is 1. A carbon fiber having a high strength and a high elongation of 7% or more is preferably used. Further, those in which a functional group such as a hydroxyl group or a carboxylic acid group is introduced on the surface of the carbon fiber by electrolytically oxidizing or ozone-oxidizing the surface of the carbon fiber are preferably used.

The compound represented by the general formula (1) used in the present invention is a reaction of an aliphatic amine represented by CH ₃ (CH ₂ ) ₁ NH ₂ (l ≧ 0) with ethylene oxide (in some cases, Reaction of the presence of alkali such as sodium hydroxide)
A compound C obtained by the reaction of laurylamine and ethylene oxide
H ₃ (CH ₂ ) ₁₁ NH (CH ₂ CH ₂ O) ₃ H and / or CH ₃ (CH ₂ ) ₁₁ NCH ₂ CH ₂ OH (CH ₂ CH ₂ O) ₂
H is preferably used. As a method for treating the carbon fiber with the compound represented by the general formula (1), a known method can be used in which the carbon fiber is immersed in a solution of the compound represented by the general formula (1) and then dried and wound. . The adhesion amount can be selected depending on the solution concentration, the dipping speed, etc., but the preferred solution is an aqueous solution, and the concentration thereof is 5% by weight or less, more preferably 1% by weight or less. When the concentration is higher than this, when the carbon fibers after treatment converge and are subsequently integrated with the thermosetting resin, the impregnating property of the resin is deteriorated, which is not preferable.

As the thermosetting resin in the present invention, any resin can be used as long as it is cured by external energy such as heat or light to form a three-dimensional cured product at least partially. Representative examples include epoxy resin, maleimide resin, polyimide resin, phenol resin, vinyl ester resin, unsaturated polyester resin, cyanate ester-terminated resin, allyl-terminated resin, acetylene-terminated resin, and nadic acid. Examples thereof include a resin having a terminal and a resin having a benzocyclobutene at the terminal. As the epoxy resin, an epoxy resin having an amine or a phenol as a precursor is particularly preferable. Specifically, tetraglycidyl diaminodiphenylmethane, triglycidyl-p-aminophenol, triglycidyl-
Examples include m-aminophenol, various isomers of triglycidylaminocresol, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin and the like. Not limited. These epoxy resins can be used alone or as a mixture.

The epoxy resin is usually used in combination with a curing agent, but the curing agent used in the present invention is not particularly limited, and a compound having a functional group capable of reacting with the epoxy resin such as an amino group or an acid anhydride group is used. It can be used as appropriate. Maleimide resins, cyanate ester resins and mixtures thereof are also preferably used as the thermosetting resin in the present invention. The maleimide resin is a resin composition containing a polyfunctional maleimide resin as a main component, and a resin composition containing 30% by weight or more of a compound having two or more maleimide groups in the molecule. A monofunctional maleimide or other copolymerizable reactive compound may be contained within a range that does not deteriorate physical properties such as heat resistance and toughness.

As the polyfunctional maleimide, the following compounds may be mentioned. 1,2-bismaleimidoethane, 1,
6-bismaleimide hexane, 1,12-bismaleimide dodecane, 1,6-bismaleimide- (2,2,4-
Trimethyl) hexane, 1,6-bismaleimide-
(2,4,4-trimethyl) hexane, 1,3-bismaleimidobenzene, 1,4-bismaleimidobenzene,
3,3'- or 4,4'-bismaleimide diphenylmethane, 3,3'- or 4,4'-bismaleimide diphenyl sulfone, 3,3'- or 4,4'-bismaleimide diphenyl ether, 2,4- , 2,6- or 3,4-bismaleimide toluene, 4,4'-bismaleimide diphenyl sulfide, 4,4'-bismaleimide dicyclohexylmethane, 4,4'-bismaleimide dicyclohexylhexene, N, N'-m -Or-
p-xylylene bismaleimide, N, N'-m-phenylene bis-citracone imide, 2,2'-bis [4-
(4-maleimidophenoxy) phenyl] propane, bis [4- (4-maleimidophenoxy) phenyl] sulfone, bis [4- (3-maleimidophenoxy) phenyl] sulfone, 1,3′-bis (4-maleimidophenoxy) Benzene, 1,3'-bis (3-maleimidophenoxy) benzene, N, N '-[1,3-phenylene-
Di- (2,2-propylidene) -di-p-phenylene]
Includes bismaleimides and the like and mixtures thereof and prepolymers of maleimide and diamine. The diamine used for the prepolymer is preferably an aromatic diamine such as diaminodiphenylmethane.

4,4'-Bismaleimidediphenylmethane and this compound and 1,6-bismaleimide- (2,4)
A eutectic mixture of 2,4-trimethyl) hexane and / or bismaleimidotoluene is particularly preferred. Examples of the reactive compound copolymerizable with the polyfunctional maleimide include alkenylphenols such as o, o'-diallylbisphenol A and diallylbisphenol F, triallyl isocyanurate, divinylbenzene, N-vinylpyrrolidone and ethylene glycol diethylene. Methacrylate etc. are mentioned.

These copolymerizable reactive compounds are used alone or in a mixture in an amount of 70% by weight or less, preferably 50% by weight or less in a resin composition containing a polyfunctional maleimide as a main component. Of these copolymerizable reactive compounds, alkenylphenols are also effective in improving the toughness and processability of a resin composition containing a polyfunctional maleimide as a main component, and are contained in the thermosetting resin in an amount of 10 to 50% by weight. It is preferable to use in the range of. The resin composition containing polyfunctional maleimide as a main component can be easily cured by heat, but a catalyst may be added for the purpose of imparting desired properties to the cured product or adjusting the curing properties. .

As the catalyst, organophosphines, organophosphonium salts, or their complexes, imidazoles, tertiary amines, quaternary ammonium salts, boron trifluoride amine complexes and organic peroxides, azobisisobutyrate. A radical polymerization catalyst such as ronitrile can be used. The amount of catalyst added may be determined according to the purpose,
From the viewpoint of stability, 0.01 to 5% by weight is preferable with respect to the total amount of the resin component.

The cyanate ester resin is a polyfunctional compound represented by the general formula Y (-O-CN) _n (wherein n is an integer of 2 to 5 and Y is an aromatic organic residue). A resin composition containing 50% by weight or more of a cyanate ester and its oligomer.
Examples of the polyfunctional cyanate ester include 1,3- or 1,4-dicyanate benzene, 4,4′-dicyanate biphenyl, 2,2′-bis (4-cyanatephenyl) propane, 2, 2'-bis (4-cyanatophenyl) ethane, bis (4-cyanatophenyl) methane,
Bis (4-cyanatophenyl) sulfone, bis (4-
Cyanatophenyl) sulfide, bis (3,4-methyl-4-cyanatophenyl) methane and the following structural formula

[0017]

[Chemical 1]

The compounds represented by or a mixture thereof are used. Further, these polyfunctional cyanates can also be used in the form of a prepolymer prepared by a reaction with a triazine oligomer by trimerization of cyanate or an amine. As the amine used for producing the prepolymer, an aromatic or aliphatic diamine is preferable. It is possible to add phenols or catalysts for the purpose of imparting desired characteristics or adjusting the curing characteristics to the thermosetting resin containing a polyfunctional cyanate ester as the main component. Usual alkylphenols can be used as the phenols, and as the catalyst, there are latent curing catalysts such as boron trifluoride amine complex, as well as tertiary amines, organic peroxides, zinc octylate, and octylate. Organic acid metal salts such as tin, copper naphthenate, zinc naphthenate and cobalt naphthenate are preferably used. The amount of catalyst added is
Although it may be determined according to the purpose, 0.05 to 3% by weight is preferable in terms of stability with respect to the total amount of the resin component.

A thermosetting resin containing a mixture of a polyfunctional maleimide (I) and a polyfunctional cyanate ester or its oligomer (II) or a pre-reacted product of (I) and (II) as a main component is also included in the present invention. It is preferably used as a thermosetting resin in. The ratio of (I) and (II) may be appropriately set according to the purpose, but the weight ratio is (I) / (II) = 5 / 95-
15/85 is particularly preferred. There is no problem in adding an epoxy resin or a polyester resin to a thermosetting resin containing a mixture of (I) and (II) or a pre-reactant as a main component, and rather preferable results can be obtained. As the epoxy resin, the publicly known ones exemplified above are used, and as the polyester resin, a compound represented by the following general formula (A) or (B) is preferable, and particularly the acid component is mainly terephthalic acid and the glycol component is Compounds which are predominantly neopentyl glycol or ethylene glycol are preferred.

[0020]

[Chemical 2]

Or

[0022]

[Chemical 3]

(In the formula, Ar represents a phenylene group, R ₁ represents a divalent aliphatic group, and R ₂ represents a divalent aromatic group or an aliphatic group.) These polyester compounds have a number average molecular weight of 500.
-10000, especially 500-3000 and a softening point of 10
Most preferable results are obtained at 0 ° C or lower, preferably 70 ° C.

The amount of the epoxy resin and polyester resin added to the thermosetting resin containing the mixture of (I) and (II) or the preliminary reaction product as the main component is 100% by weight of the mixture of the (I) and (II) or the preliminary reaction product. The amount is 5 to 100 parts by weight of the epoxy resin and 5 to 50 parts by weight of the polyester compound, but the addition amount of 30 parts by weight or less is often sufficient. In the case of a thermosetting resin containing a mixture of (I) and (II) or a preliminary reaction product as a main component, a catalyst may be added depending on the purpose. The catalyst may be appropriately selected according to the purpose from those exemplified above for the thermosetting resin containing a polyfunctional maleimide or a polyfunctional cyanate ester as a main component. The amount of the catalyst added may be determined according to the purpose, but is 0.2 to the total amount of the resin components.
3% by weight is preferable from the viewpoint of stability. Furthermore, a nadic acid-terminated or acetylene-terminated polyimide resin is also preferably used as the thermosetting resin. As a nadic acid-terminated polyimide resin, aromatic diamine as a raw material monomer such as PMR-15

[0025]

[Chemical 4]

Diester of aromatic tetracarboxylic acid

[0027]

[Chemical 5]

Monoester of nadic acid

[0029]

[Chemical 6]

A partial condensate or B-staged resin obtained from or a nadic acid-terminated polyimide oligomer after complete condensation imidization, for example,

[0031]

[Chemical 7]

A thermosetting resin containing as a main component can be mentioned. Further, Thermid 6 which is known as a trademark of THERMID as an acetylene-terminated polyimide resin is used.
00, Thermid IP-600, etc. are suitable.
Examples of the resin having a benzocyclobutene terminal include methanone and 1,3-phenylenebis- [bicyclo (4,2,2
0) octa-1,3,5-trien-3-yl-] and the like, and a mixture of a resin having a benzocyclobutene terminal and a polyfunctional maleimide, and the like.

As the thermosetting resin in the present invention, it is also possible to use the above thermosetting resin to which a thermoplastic resin or an oligomer thereof is added. Particularly, so-called engineering plastics such as polyimide, polyetherimide, polysulfone, polyethersulfone, and polyetheretherketone are preferable from the viewpoint of heat resistance, and those having a functional group capable of reacting with a thermosetting resin at the molecular end or in the molecular chain are preferable. More preferable. These thermoplastics are
It may be dissolved in a thermosetting resin or may be mixed as a fine powder.

The amount of the thermoplastic resin component added to the thermosetting resin component is preferably 30% by weight or less, more preferably 15% by weight or less. If the amount of the thermoplastic resin component added exceeds 30% by weight, the viscosity of the system becomes too high, which not only causes impregnation failure during prepreg formation, but also causes the prepreg tack property and drape property to significantly decrease. Become. It is also possible to add a small amount of inorganic fine particles such as finely powdered silica or an elastomer component such as butadiene / acrylonitrile copolymer to the thermosetting resin within a range that does not sacrifice prepreg characteristics, processing characteristics, mechanical characteristics, thermal characteristics, etc. It is possible.

The ratio of the carbon fiber treated with the compound (1) to the thermosetting resin in the carbon fiber reinforced thermosetting resin prepreg of the present invention can be appropriately set according to the purpose, but the weight ratio. The range of 60/40 to 75/25 is particularly preferable. Further, in the present invention, a thermoplastic resin molded product is present on the surface of the prepreg. This thermoplastic resin molded product may be applied to one side or both sides of the prepreg. As the thermoplastic resin of this thermoplastic resin molded product, polyamide, polyester, polyimide,
Examples include so-called engineering plastics such as polyether imide, polyamide imide, polybenzimidazole, polyaryl sulfone, and polyether ether ketone, super engineering plastics, and polymer alloys. Those having a functional group capable of reacting with a thermosetting 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, and these have a functional group at a terminal or a molecule by a means such as copolymerization. The engineering plastic introduced in the chain, the super engineering plastic, the polymer alloy, or the like.

Further, in particular, it dissolves in a thermosetting resin in the course of molding and curing and undergoes phase separation. Among them, especially after curing, the thermoplastic resin exhibits a sea-island structure of islands, and the thermosetting resin exhibits an island-island structure. Polyetherimide is preferably used. Examples of the form of the thermoplastic resin molded product include fibrous form, particulate form, and film form. As the particulate thermoplastic resin molded product, those commercially available as fine particles of the above-mentioned engineering plastics and super engineering plastics can be used, and those not commercially available as fine particles can be made into fine particles by a known method such as pulverization. use. Particle size is 10
It is preferably 0 μm or less, more preferably 2 to 60 μm.
Is.

The fibrous thermoplastic resin molding can be obtained by a known method such as melt spinning or solution spinning of the engineering plastic or super engineering plastic. The form of the fiber is not particularly limited, such as a long fiber monofilament, a bundle thereof, or a short fiber form. The diameter of the fiber is preferably 100 μm or less, 50 μm
m or less is particularly preferable. Further, the woven fabric made of the fibrous thermoplastic resin, and the structure thereof is not particularly limited, such as plain weave, satin weave, and woven weave. Nonwoven fabrics can also be used. The woven fabric preferably has a woven fabric weight (weight per unit area) of 1 to 25 g / m ² .

Among these thermoplastic resin moldings,
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 possible to control the tack level of the prepreg. (3) It is not necessary to handle a high-viscosity material, 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 of these forms may be used in combination, for example, by arranging a fibrous product and a particulate product on the surface of the prepreg.

The thermoplastic resin molding is a thermosetting resin 10.
It is used in a ratio of 0.5 to 50 parts by weight with respect to 0 parts by weight.
If it is less than 0.5 parts by weight, sufficient toughness improving effect is not obtained, and if it exceeds 50 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 It is not preferable because the solvent property may be lowered.

Next, a carbon fiber reinforced thermosetting resin in which a thermoplastic resin molded product is present on one surface or both surfaces of the carbon fiber treated with the compound (1), the thermosetting resin and the thermoplastic resin molded product. A method for manufacturing a prepreg is shown. This method is, for example, (1) forming a resin film with a thermoplastic resin in the form of particles dispersed in a thermosetting resin, and aligning carbon fibers treated with the aligned compound (1) with the resin film. A method of impregnating with scissors, and in the impregnation process, the particulate thermoplastic resin is filtered by the carbon fibers so that it is substantially present on the surface of the prepreg. (2) A prepreg is prepared from a carbon fiber treated with the compound (1) and a thermosetting resin by a usual method, and its surface is
A method in which a particulate thermoplastic resin or a fibrous (short fiber) thermoplastic resin is sprinkled and integrated, or a method in which fibrous (long fiber) thermoplastic resins are gathered and integrated. (3) A resin film in which the aligned fibrous thermoplastic resin is impregnated with a thermosetting resin, and the compound (1)
Although it is a method of manufacturing from carbon fiber treated with
There is no particular limitation.

The preferred embodiment of the present invention is as follows. That is, in the carbon fiber reinforced thermosetting resin prepreg of the present invention, As the thermosetting resin, a maleimide resin containing polyfunctional maleimide and alkenylphenol as main components is used. 2. As the thermosetting resin, a mixture of a polyfunctional maleimide and a polyfunctional cyanate ester or a pre-reacted product thereof with an epoxy compound and / or a polyester compound is used. 3. As a thermosetting resin, known as PMR-15 and the like, a B-stage resin obtained from aromatic diamine as a raw material monomer, diester of aromatic tetracarboxylic acid and monoester of nadic acid, or nadic after complete imidization A thermosetting polyimide resin whose main component is an acid-terminated polyimide oligomer is used. 4. As the carbon fibers, fibers treated with an aqueous solution of a compound represented by the general formula (1) in an amount of 1% by weight or less are used.

[0042]

The present invention will be described in more detail with reference to the following examples. Reference Example 1 g of sodium hydroxide as a catalyst was added to 1 mol of laurylamine, heated to 150 to 180 ° C., and ethylene oxide was blown into a 4 mol liquid while stirring for reaction. After completion of the reaction, hydrochloric acid was added to neutralize and CH ₃ (C
H ₂ ) ₁₁ NH (CH ₂ CH ₂ O) ₃ H and CH ₃ (CH ₂ ) ₁₁ N
A mixture of CH ₂ CH ₂ OH (CH ₂ CH ₂ O) ₂ H was obtained.

(Examples 1 to 3) A 0.2% aqueous solution of the compound synthesized in Reference Example was prepared. A high-strength medium-elastic carbon fiber (MR-50K, manufactured by Mitsubishi Rayon Co., tensile strength 5600 MPa, elastic modulus 300 GPa: surface is oxidized and surface sizing agent is not attached) was dipped and passed through this aqueous solution. . Then, it was dried with hot air at 130 ° C. for 2 minutes and wound up. Furthermore, at 80 ° C for 12 hours 15 mmH
It was sufficiently dried under reduced pressure of g or less. The treated carbon fiber showed the same appearance as the untreated one. Next, a unidirectional prepreg was manufactured by the hot melt method from the resin composition shown in Table 1 and the carbon fiber treated as described above. The prepreg areal weight was 145 g / m ² and the resin content was 30% by weight. On the other hand, a polyimide of Matrimide 5218 (manufactured by Ciba Geigy) was dissolved in a methylene chloride / methanol mixed solvent (methylene chloride / methanol = 90/10 weight ratio) and adjusted to a predetermined viscosity (about 1200 poise), and extruded into a fibrous shape. Then, it was dried and wound up to prepare a fibrous thermoplastic resin having 200 denier / 52 filaments.

The above-mentioned fibrous thermoplastic resin was placed on both surfaces of the above prepreg and in the same direction as the carbon fibers so as to have a fibrous thermoplastic resin areal weight of 11 g / m ² per side at 2 mm intervals and lightly. Impregnated. Thus, the carbon fiber reinforced thermosetting resin prepreg of the present invention was obtained. This prepreg was cut into a predetermined size and number of sheets, four layers were laminated in the directions of carbon fibers of + 45 °, 0 °, −45 °, 90 °, four times, and then 90 °, −45 °, 0 °, After laminating 4 layers at + 45 ° and 4 times, it was cured in an autoclave under curing conditions of 180 ° C. for 6 hours and further cured at 232 ° C. for 6 hours to prepare a test piece for measuring post-impact compression strength. SAC using this test piece
MA (Supplier of Advanced C)
objectives Materials Asoci
ation) Recommended Method
The compressive strength after impact of 1500 in-lb / in was measured according to SRM2-88. The results are shown in Table 1.

(Comparative Examples 1 to 3) Test pieces were prepared and evaluated in the same manner as in Examples 1, 2 and 3 except that the carbon fiber which was not treated with the aqueous solution of the compound synthesized in Reference Example was used. The results are shown in Table 1.

(Examples 4 to 6) Polyetherimide (Ultem 1000 manufactured by General Electric Co.) was used in place of the matrimide 5218, and was shaped into a fiber in the same manner.
Fibers of 00 denier / 52 filaments were obtained. Using this fiber, test pieces were prepared and evaluated in the same manner as in Examples 1, 2, and 3. Table 2 shows the results.

(Examples 7 to 9) Carbon fibers treated in the same manner as in Example 1 were obtained. On the other hand, 15 wt% of matrimide 5218 powder (particle size: 80 μm or less) was added to each of the resin compositions of Examples 1, 2 and 3, and the mixture was mixed by a mixer at 70 ° C. and uniformly dispersed in the resin. Each of these was spread on a release paper to form a resin film having a resin areal weight of 40 g / m ² . With each resin film, the treated carbon fibers aligned in one direction were sandwiched from above and below to prepare a prepreg by a hot melt method. The basis weight of carbon fiber is 145 g / m ²
Met. The matrimide 5218 powder dispersed in the resin was substantially collected on the surface of the prepreg during the process of impregnating the carbon fiber with the carbon fiber to obtain the prepreg of the present invention. Using these prepregs, Example 1,
Test pieces were prepared and evaluated in the same manner as 2 and 3. Table 2 shows the results. (Example 10)

As the thermosetting resin, a so-called PMR composed of methylene dianiline, benzophenone tetracarboxylic acid dimethyl ester and nadic acid monomethyl ester.
The treated carbon fiber or the like of Example 1 was passed through an alcohol solution of -15 resin, which was further wound around a drum at regular intervals and the solvent was air-dried. Example 1 on the obtained base prepreg
The matrimide 5218 fiber obtained in 1. was wrapped around both surfaces of the prepreg at 2 mm intervals, lightly impregnated, and cut open to give a carbon fiber basis weight of 190 g / m ² , resin (matrimide 521
A prepreg of the present invention having a content of 35% by weight (including 8 fibers) and a volatile content of 6% by weight was obtained. A predetermined number of prepregs were cut into a predetermined size, and the remaining solvent was removed and B stage (imidation reaction) was performed in a hot air dryer at 200 ° C. for 1 hour. Further (+ 45 ° / 0 ° / −45 ° /
90 °) Laminated on _3S , set in mold and press molded (31
A molded panel was obtained at 5 ° C. and 1000 psi for 4 hours, and evaluated in the same manner as in Example 1. The compressive strength after impact damage was 208 MPa.

Comparative Example 4 A test piece was obtained in the same manner as in Example 10 except that untreated carbon fiber was used. The compressive strength after impact damage was 165 MPa.

[0050]

[Table 1]

[0051]

[Table 2]

In Tables 1 and 2, each abbreviation means the following. MDABMI: 4,4'-bismaleimide diphenylmethane (manufactured by Mitsui Toatsu) Compimide 353: eutectic mixture of bismaleimide (manufactured by Shell) Matrimid 5292B: diallyl bisphenol A (manufactured by Ciba Geigy) BCN: 2,2-bis ( 4-Cyanatophenyl) propane (manufactured by Ciba Geigy) Tactics 742: triglycidyl type epoxy resin (manufactured by Dow) Epicoat 807: bisphenol F type epoxy resin (manufactured by Yuka Shell Co.)

[0053]

The carbon fiber reinforced resin composite material obtained from the carbon fiber reinforced thermosetting resin prepreg of the present invention has excellent toughness without impairing the heat resistance of the matrix resin. Therefore, it is extremely useful as a prepreg capable of molding a composite material that can be suitably used as a structural material for aerospace and the like.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hidehiko Ohashi 20-1 Miyuki-cho, Otake-shi, Hiroshima Mitsubishi Rayon Co., Ltd. Central Research Laboratory

Claims (2)

[Claims] 1. A carbon fiber-reinforced thermosetting resin prepreg in which a carbon fiber is used as a reinforcing material, a thermosetting resin is used as a matrix resin, and a thermoplastic resin molding is present on the surface, and the carbon fiber is represented by the general formula (1). A carbon fiber reinforced thermosetting resin prepreg, which comprises using a carbon fiber treated with a compound represented by: CH ₃ (CH ₂ ) _l N (CH ₂ CH ₂ O) _m H (CH ₂ CH ₂ O) _n H (1) (where l ≧ 0, m ≧ l, n ≧ l) 2. The carbon fiber reinforced thermosetting resin prepreg according to claim 1, wherein the thermoplastic resin molding is fibrous.