Nippon Steel Chemical & Material Co., Ltd.

Mazda Motor Corporation

Nippon Graphite Fiber Corporation

Koichi Hattori

Kenji Nishida

Tetsuya Sugiyama

Yutaka Arai

Masanori Honda

Chikara Kawamura

Naoki Yokoyama

Masaki Shimada

Katsuya Himuro

Yuki Kodama

Hironobu Takahama

Provided is a frame which is made of a fiber reinforced composite and where a bending strength and a vibration damping capability are compatible. The frame which is made of a fiber reinforced composite includes: a compressive wall part where a compressive stress occurs in a longitudinal direction of the frame when the frame receives a bending load in a normal direction perpendicularly intersecting the longitudinal direction; a side wall part extending in the normal direction and defining one of the corners with the compressive wall part; and a tension wall part which is away from the compressive wall part and extends in the longitudinal direction, and where a tensile stress occurs in the longitudinal direction when the frame receives the bending load. The tension wall part has a loss coefficient which is larger than a loss coefficient of the compressive wall part by 0.005 or more.

Frame which is made of fiber reinforced composite

Disclosed is a polyurethane-modified epoxy resin composition capable of satisfying both high toughness and high elasticity. This epoxy resin composition is an epoxy resin composition, in which (A) a polyurethane-modified epoxy resin having a polycarbonate structure in the molecule and having a urethane modification rate of 20 to 60% by weight, (B) a non-polyurethane-modified epoxy resin that is liquid at 30&#xb0; C., (C) a solid epoxy resin having a glass transition temperature or melting point of 50&#xb0; C. or higher and (D) an amine-based curing agent that is dicyandiamide or a derivative thereof are as essential components, and 20.0 to 50.0% by weight of (A), 0.1 to 50.0% by weight of (B) and 0.1 to 50.0% by weight of (C) are contained relative to the total of (A) to (D).

Epoxy resin composition and cured product

Provided are an epoxy resin composition and a film or a molding material. The epoxy resin composition is an epoxy resin composition including the following components A to D: component A: an epoxy resin having an oxazolidone ring structure in a molecule thereof; component B: an epoxy resin that is liquid at 30&#xb0; C.; component C: a diblock copolymer having a B-M structure (where M represents a block formed of a homopolymer of methyl methacrylate or a copolymer containing at least 50 wt % of methyl methacrylate, B represents a block that is incompatible with the epoxy resins and the block M, and that has a glass transition temperature Tg of 20&#xb0; C. or less, and respective blocks represented by B and M are directly bonded to each other or are linked to each other through a linking group); and component D: an amine-based curing agent that is dicyandiamide or a derivative thereof.

Epoxy resin composition and cured object obtained therefrom

Provided is a polyurethane-modified epoxy resin composition having satisfactory operability of processing, such as casting or impregnation, in a composition state. The epoxy resin composition includes, as essential components, the following components (A) to (D): (A) a low-concentration polyurethane-modified epoxy resin containing a polyurethane having an epoxy resin added to each of both terminals thereof and/or one terminal thereof; (B) a polyurethane-unmodified epoxy resin that is liquid at 30&#xb0; C.; (C) a solid epoxy resin having a bisphenol structure, the resin having a glass transition temperature or a melting point of 50&#xb0; C. or more; and (D) an amine-based curing agent that is dicyandiamide or a derivative thereof, wherein the epoxy resin composition includes the component (A) at from 3.0 wt % to 30.0 wt %, and the component (C) at from 0.1 wt % to 40.0 wt % with respect to the total of the components (A) to (D).

To provide prepreg having high thermostability and a molded body (fiber reinforced composite) obtained from the prepreg, the prepreg is formed by impregnating a reinforced fiber having an elastic modulus of 100 to 900 GPa with an epoxy resin composition including the following Components A to D so as to have a resin content within a range of 25 to 50 mass %: Component A: an epoxy resin having an oxazolidone ring structure in a molecule thereof; Component B: an epoxy resin that is liquid at 30&#xb0; C.; Component C: a diblock copolymer having a B-M structure, wherein M is a block including at least 50 mass % of methyl methacrylate, B is a block immiscible with the epoxy resins and the block M, a glass transition temperature of the block B being 20&#xb0; C. or lower; and Component D: dicyandiamide, or an amine curing agent that is a derivative of dicyandiamide.

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Tokyo, Japan

Koichi Hattori