JPH06298908A - Resin composition for prepreg, prepreg and composite material - Google Patents

Abstract

(57) [Summary] [Purpose] Providing excellent heat resistance, toughness and mechanical strength
Resin composition for prepreg that can be used, prepreg and the same
A composite material using the same is provided. [Constitution] (A) Epoxy resin (B) The following general formula [Chemical 1] (In the formula, R¹ , R² , R³ And R^Four Each has 1 to 4 carbon atoms
An aromatic amine, which represents an alkyl group), and (C) A thermoplastic resin is contained as an essential component.
A characteristic prepreg resin composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for prepreg excellent in heat resistance and toughness, a prepreg composed of the composition and a reinforcing fiber, and a composite material obtained by curing the prepreg. It is optimal for aircraft primary structural materials that require toughness.

[0002]

2. Description of the Related Art Composite materials containing carbon fiber as a reinforcing material have come to be used for sports / leisure products such as golf shafts, fishing rods, and tennis rackets, aircraft, space satellites and their parts, and general industrial materials.

Epoxy resins are generally used as matrix resins such as carbon fibers used for these purposes. However, epoxy resin cured products generally have poor toughness and are brittle. Therefore, the composite material using this epoxy resin as a matrix is inferior in impact resistance.

In order to solve this problem, a method of adding a rubber to the matrix resin has been proposed. However, although the impact resistance is slightly improved, the heat resistance and mechanical strength are lowered, so that the compounding amount thereof is limited. Has been done and was inadequate.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves these problems of the prior art and can provide excellent heat resistance, toughness and mechanical strength, a prepreg resin composition, a prepreg and a composite using the same. The purpose is to provide wood.

[0006]

The inventor of the present invention has completed the present invention as a result of an examination for solving the above-mentioned problems.

That is, the present invention relates to (A) epoxy resin,
(B) The following general formula (1)

[0008]

[Chemical 2]

An aromatic amine represented by the formula (wherein R ¹ , R ² , R ³ and R ⁴ each represent an alkyl group having a prime number of 1 to 4) and (C) a thermoplastic resin are essential components. And a resin composition for a prepreg. The present invention also relates to a prepreg comprising the prepreg resin composition and reinforcing fibers, and the present invention relates to a composite material obtained by curing the prepreg.

The epoxy resin (A) used in the present invention includes bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, glycidyl amine type epoxy resin, alicyclic epoxy resin. Various epoxy resins such as resin, glycidyl ester type epoxy resin and tris (glycidyl ether phenyl) methane can be used, and a mixture of two or more of these epoxy resins can also be used. The aromatic amine which is the component (B) of the present invention is represented by the following general formula (1).

[0011]

[Chemical 3]

In the formula, R ¹ , R ² , R ³ and R ⁴ each represent an alkyl group having 1 to 4 carbon atoms, preferably an ethyl group or an isopropyl group, and the above R ¹ , R ² , R ³ R ⁴ and R ⁴ may be the same or different groups, but are preferably the same. At this time, R ¹ , R ² , R
^When the carbon number of ³ and R ⁴ is 5 or more, the melting point becomes high and mixing becomes difficult, so that it cannot be used. Examples of the aromatic amine represented by the general formula (I) include 3,
Preferable examples include 3 ', 5,5'-tetraethyl-4,4'-diaminodiphenylmethane and 3,3', 5,5'-tetraisopropyl-4,4'-diaminodiphenylmethane. This is a liquid at room temperature,
Since a large amount of the thermoplastic resin as the component (C) can be mixed, it has a great effect on improving the impact resistance of the composite material.

The ratio of the epoxy resin (A) to the component (B) is such that the active hydrogen of the component (B) is 0.5 to 1.5 mol per mol of the epoxy group.

Further, a curing accelerator can be added if necessary. Benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) as a curing accelerator
Tertiary amines such as phenol, imidazoles such as 2-ethyl-4-methylimidazole, boron trifluoride amine complex and the like can be used. The mixing ratio can be appropriately determined.

Examples of the thermoplastic resin as the component (C) of the present invention include polycarbonate, polysulfone, polyether sulfone, polyetherimide, aromatic polyester, polyamide and the like, but in view of heat resistance. Polysulfone, polyether sulfone and polyether imide are preferred. The amount used is 10 to 100 parts by weight with respect to 100 parts by weight of the epoxy resin as the component (A). 1
If it is less than 0 part by weight, the impact resistance of the composite material becomes insufficient. On the other hand, if it is more than 100 parts by weight, the viscosity of the resin composition for prepreg is excessively increased and it becomes difficult to impregnate the reinforcing fiber.

The method of blending the resin composition in the present invention is not particularly limited, but it is preferable to heat and mix the components (A) and (C), cool the mixture, and then add the component (B).

The present invention is within the scope of not impairing its purpose.
It is also possible to add fine particles of a thermoplastic resin. Examples of the fine particles of this thermoplastic resin are polyacrylate, polyvinyl acetate, polystyrene, polyamide, polyaramid, polyester, polyacetal, polycarbonate, polyphenylene oxide, polyphenylene sulfide, polyarylate, polybenzimidazole, polyimide, polyamideimide, polyether. Examples thereof include imide, polysulfone, polyether sulfone, polyether ether ketone, polyethylene, polypropylene, polyacetal and polyester.

Further, in the present invention, a filler may be used in the resin composition as long as the purpose is not impaired.
Examples thereof are asbestos, alumina, attapulgite, kaolin clay, carbon black, graphite, finely divided silicic acid, calcium silicate, diatomaceous earth, magnesium oxide, titanium oxide, iron oxide, magnesium hydroxide, aluminum hydroxide. , Slate powder, sericite,
Examples thereof include quartz powder (flint), calcium carbonate, magnesium carbonate, talc, feldspar powder, molybdenum disulfide, perlite, vermiculite, whiting, mica, wax stone clay, gypsum (anhydrous) and the like.

The resin composition for prepreg of the present invention is used by impregnating reinforcing fibers (materials). Examples of the fiber used as the reinforcing fiber include carbon fiber, graphite fiber, glass fiber, silicon carbide fiber, silica alumina fiber, alumina fiber, titania fiber, aromatic polyamide fiber, aromatic polyester fiber, polybenzimidazole fiber and the like. To be

The resin content of the above-mentioned fiber impregnated with the resin composition for prepreg of the present invention is generally 20 to 90 vol.
%, Preferably 25 to 70 vol%.

[0021]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

(Measurement Method) The measurement method in the following Examples and Comparative Examples is as follows. (1) The Tg of the resin cured product was measured by DSC. (2) The strain energy release rate was based on ASTM E-399. (3) Damaged area of the fiber composite material is 150 g / mm ² prepregs having a basis weight of 24 plies are pseudo isotropically laminated, press-molded under predetermined curing conditions, cut into 80 mm squares, and fixed at 10 mm on each side, 60 mm A falling weight impact of 350 kg · cm / cm was applied to the center of the square with corners, and quantification was performed by ultrasonic C-Scan.

Example 1 As an epoxy resin, 80 parts by weight of polyetherimide (product name Ultem, manufactured by GE Plastics Co., Ltd.) was added to 100 parts by weight of product name ELM100 (produced by Sumitomo Chemical Co., Ltd.) and dissolved. , 3,3 ′, 5,5′-Tetraisopropyl-4,4′-diaminodiphenylmethane was added in an amount of 100 parts by weight to obtain a resin composition for prepreg.

When this resin composition was cured at 180 ° C. for 3 hours, Tg was 260 ° C. The strain energy release rate was 1.0 KJ / mm ² .

Further, the resin composition was impregnated into carbon fiber (trade name: T800H, manufactured by Toray Industries, Inc.), and the damaged area was measured by the above-mentioned method. The result was 6.0 cm ² .

Comparative Example 1 A resin composition for prepreg was prepared by removing the polyetherimide from Example 1.

When cured in the same manner as in Example 1, the Tg was 260 ° C., but the strain energy release rate was 0.16K.
It was J / mm ² .

Further, the damaged area of the prepreg was measured in accordance with Example 1, and it was 27 cm ² .

Example 2 YH434 (trade name of Tohto Kasei Co., Ltd.) as an epoxy resin
60 parts by weight of GAN (manufactured by Nippon Kayaku Co., Ltd.) and 40 parts by weight of GAN (manufactured by Nippon Kayaku Co., Ltd.)
00P, manufactured by Imperial Chemical Industry Co., Ltd.) 40 parts by weight were added and dissolved, and then 3, 3 ′, 5,
A resin composition for prepreg was obtained by adding 50 parts by weight of 5'-tetraethyl-4,4-diaminodiphenylmethane.

When this resin composition was cured at 180 ° C. for 2 hours and 200 ° C. for 2 hours, Tg was 220 ° C. The strain release energy was 0.91 KJ / mm ² .

The damaged area of the prepreg was measured in accordance with Example 1 and found to be 5.8 cm ² .

Comparative Example 2 A resin composition for prepreg was prepared by removing polyether sulfone from Example 2.

When this resin composition was cured in the same manner as in Example 2, the Tg was 220 ° C., but the strain energy release rate was 0.11 KJ / mm ² .

The damaged area of the prepreg was measured in accordance with Example 1 and found to be 28.5 cm ² .

[0035]

The resin composition for prepreg of the present invention is excellent in heat resistance and toughness. Further, a composite material obtained by impregnating this resin composition into reinforcing fibers to form a prepreg and curing the prepreg is excellent not only in heat resistance and toughness but also in mechanical strength.

Claims (3)

[Claims] 1. (A) Epoxy resin (B) The following general formula:(In the formula, R¹ , R² , R³ And R^Four Each has 1 to 4 carbon atoms
Aromatic amine represented by (indicating an alkyl group) and (C) a thermoplastic resin are contained as essential components.
A characteristic prepreg resin composition. 2. A prepreg comprising the prepreg resin composition according to claim 1 and reinforcing fibers. 3. A composite material obtained by curing the prepreg according to claim 2.