Mitsubishi Chemical Corporation

Mitsubishi Rayon Company, Limited

Yasuhiro Fukuhara

Manabu Kaneko

Hisaya Ushiyama

Kenichi Watanabe

Tomoko Ishimoto

Sanae Kita

Yasuo Takagi

Akihiro Ito

Kazutami Mitani

Kiharu Numata

Kazuki Koga

Junichi Muramatsu

Tadayoshi Saitou

Tomoo Sano

Ietsugu Santo

Mina Oobayashi

The present invention pertains to a prepreg containing reinforcing fibers and an epoxy resin composition. Said prepreg is sandwiched between dies preheated to 140.degree.C. and pressurized to MPa and held for five minutes at this temperature to obtain a cured article having a G'Tg of at least 150.degree.C. The present invention also pertains to a fiber-reinforced composite material and a method for producing same. According to this invention, it is possible to provide a prepreg which is well suited to press-molding, particularly to high-cycle press-molding. It is also possible to provide a fiber-reinforced composite material which can be heat-cured at a lower temperature and over a shorter time than conventional methods, with which it is possible to minimize excessive flow of resin in hot-press curing, and which is resistant to performance defects such as fiber meandering and defects in surface appearance. A method for producing the same can also be provided.

Prepreg, fiber-reinforced composite material, method for producing same, and epoxy resin composition

The present invention is an epoxy resin composition characterized by containing component A (epoxy resin containing sulfur atoms in the molecule thereof); and component B (an epoxy resin composition containing an imidazole compound represented by formula (1), and at least one of the following components: component C (an imidazole compound represented by formula (2) below) or component D (an epoxy resin composition having at least one sulfur atom in the molecule. According to the present invention, it is possible to provide an epoxy resin composition which has outstanding stability when stored at room temperature, and which can be heat-cured at a relatively low temperature and over a short time, to give a resin with a high heat resistance when cured. (In formula (1), Rrepresents a straight-chain or branched-chain alkyl group having 1 to 5 carbon atoms, or a hydroxymethyl group, Rrepresents a straight-chain or branched-chain alkyl group having 1 to 5 carbon atoms, or a hydrogen atom.) (In formula (2), Rrepresents an organic group having 1 or more carbon atoms, and Rto Rrepresent hydrogen atoms, methyl groups or ethyl groups.) 

Epoxy resin composition, prepreg, fiber-reinforced composite material, and method for producing same

An epoxy-resin composition of the components (A), (B), (D) and (E), where component (A) is an epoxy resin having an oxazolidone-ring structure, (B) is a bisphenol bifunctional epoxy resin with a number-average molecular weight of at least 600 but no more than 1300, which does not have an oxazolidone-ring structure, (D) is a triblock copolymer, and (E) is a curing agent. A film made of the epoxy-resin composition, a prepreg and a fiber-reinforced plastic is also disclosed. The epoxy resin composition is capable of achieving both a processability of a prepreg at room temperature and a suppression of voids in the molded product. A fiber-reinforced plastic having excellent mechanical properties, especially excellent fracture toughness and heat tolerance, is also obtained by using the epoxy-resin composition.

Epoxy-resin composition and film, prepreg, and fiber-reinforced plastic using same

The present invention relates to an epoxy-resin composition comprising the following components (A), (B), (C) and (D), a film made of the epoxy resin composition, a prepreg and a fiber-reinforced plastic. The present invention can provide an epoxy-resin composition that cures at a low temperature in a short period of time. Also, the present invention can provide a fiber-reinforced plastic having excellent mechanical characteristics, especially excellent fracture toughness and heat tolerance, is made from the epoxy-resin composition. 

Epoxy-resin composition, and film, prepreg and fiber-reinforced plastic using the same

Provided is a method for producing a good epoxy resin composition for obtaining fiber-reinforced plastics. A production method for obtaining a fiber-reinforced composite material by impregnating a fiber assembly with an epoxy resin composition and then curing the epoxy resin composition, wherein the epoxy resin composition contains a component [A], a component [B] and a component [C] respectively satisfying the conditions described below. When the blending amount of the component [B] is set to b parts by mass and the blending amount of the component [C] is set to c parts by mass relative to 100 parts by mass of the component [A] contained in the epoxy resin composition, formula (2) is satisfied within the range of formula (1), formula (4) is satisfied within the range of formula (3), and formula (6) is satisfied within the range of formula (5).

Production method for obtaining fiber-reinforced composite material, and epoxy resin composition used therein

A prepreg is provided capable of being a composite material having suitable high heat resistance, impact resistance, and mechanical properties under high temperature and high humidity conditions. As the matrix resin, a composition including a specific epoxy resin component (A), a specific bifunctional epoxy resin (B), a specific tetrafunctional epoxy resin (C), and a specific aromatic amine compound (D) at specific proportions are used. Particularly, as the epoxy resin component (A), one obtained by mixing and heating a bifunctional epoxy resin (a1), a trifunctional epoxy resin (a2), a phenol compound (a3), and a specific polyamide resin (a4) is used so as to be able to solve the above-described problems.

Prepreg

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Toyohashi, Japan

Yasuhiro Fukuhara