Mitsubishi Rayon Company, Limited

Tadayoshi Saito

Naoki Sugiura

Masato Taguchi

Yasuo Takagi

Takashi Kaneko

Kazutami Mitani

Kazuya Goto

Shigetsugu Hayashi

Koki Wakabayashi

Tomonori Okuda

A sizing agent for carbon fiber comprising either a component (A) and a component (B), or alternatively, a component (A'), a component (B&#x2032;) and a component (D), each of which is described below. Component (A): an epoxy compound with at least 1 epoxy group within each molecule, and with a surface energy of 17 to 34 mJ/m; component (B): an epoxy compound with at least 1 epoxy group within each molecule, and with a surface energy of at least 35 mJ/m; component (A&#x2032;): an epoxy compound with at least 2 epoxy groups within each molecule, and with a surface energy of 17 to 34 mJ/m; component (B&#x2032;): an epoxy compound with at least 2 epoxy groups within each molecule, and with a surface energy of at least 35 mJ/m; and component (D): an anionic surfactant with an aryloxy group as a hydrophobic group, with an ammonium ion as a counter ion, and with an alkylene oxide addition quantity of no more than 10 moles.

Sizing agent for carbon fiber, aqueous dispersion of the same, carbon fiber treated by sizing, sheet comprising the carbon fiber, and carbon fiber-reinforced composite material

The present invention provides a sizing agent capable of imparting superior resin impregnation and adhesion with resin, and more particularly, a carbon fiber sizing agent that have satisfactory emulsification stability having stable process throughput and minimizes the changes over time in the sized carbon fibers. The carbon fiber sizing agent contains (A) a compound having at least one epoxy group per molecule, (B) an anionic surfactant having an ammonium ion as the counter ion, and (C) a nonionic surfactant wherein, the nonionic surfactant (C) is contained at 1/50 to &#xbd; (weight ratio) relative to the anionic surfactant (B).

Sizing agent for carbon fiber, aqueous dispersion thereof, carbon fiber treated by sizing sheet-form object comprising the carbon fiber, and carbon fiber-reinforced coposite material

Epoxy resin compositions comprising (a) an epoxy resin, (b) a latent curing agent with curing power at 100&#xb0; C. or below and (c) an aromatic amine-based curing agent and/or an alicyclic amine-based curing agent, which are curable in two stages, or epoxy resin compositions further comprising (d) a curing accelerator, as well as a prepregs comprising reinforcing fiber materials impregnated with the epoxy resin compositions. The compositions give die-releasable cured products by primary curing at low temperature, give highly heat-resistant cured products by secondary curing, and exhibit satisfactory stability at room temperature.

Epoxy resin composition and prepreg made with the epoxy resin composition

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Nagoya, Japan

Tadayoshi Saito