Mitsubishi Chemical Corporation

Kenji Kaneta

Takaaki Suzuki

Atsushi Nakajima

Kouki Wakabayashi

Akihiro Ito

Naoki Sugiura

Katsuhiko Ikeda

Norifumi Hirota

Hiroyuki Nakao

Kenji Hirano

Akito Hatayama

Naomasa Matsuyama

Tsuyoshi Takada

Akihiro Itou

Yuutarou Nakamura

Hiroko Matsumura

Tadashi Ootani

A sizing agent is provided, the sizing agent includes a component (A) and a component (B), wherein a mass ratio A/B of the component (A) to the component (B) is 0.5 to 20, and a proportion of a total mass of the component (A) and the component (B) with respect to a total mass of the sizing agent is 80% by mass or more, wherein the component (A) is an epoxy resin having a viscosity of 1 to 180,000 Pa·s at 30° C., and the component (B) is an aliphatic ester compound having a freezing point of 50° C. or lower.

Sizing agent, reinforcement fiber tow, fiber-reinforced resin-molding material, and fiber-reinforced composite material

A first aspect of the present invention is carbon fiber wherein the surface of a monofilament has a center line average roughness Ra of 6.0 nm or more and 13 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. A second aspect of the present invention is carbon fiber precursor acrylic fiber wherein the surface of a monofilament has a center line average roughness Ra of 18 nm or more and 27 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. The carbon fiber according to the first aspect is obtained by stabilizing and carbonizing under specific conditions the carbon fiber precursor acrylic fiber according to the second aspect.

Carbon fiber precursor acrylic fiber, carbon fiber, and method for producing same

A sizing agent for carbon fiber includes component (A), component (B), and component (C), in which the component (A) is at least one selected from the group consisting of component (A-1), component (A-2), and component (A-3); the component (A-1) is a urethane compound having a structure of Formula (1-1) in the molecule, the component (A-2) is an ester compound having a structure represented by Formula (1-2) in the molecule, the component (A-3) is an amide compound having a structure of Formula (1-3) in the molecule; the component (B) is an epoxy compound selected from the group consisting of an epoxy compound represented by Formula (2), an epoxy compound represented by Formula (3), and an epoxy compound represented by Formula (4); and the component (C) is a bisphenol type epoxy compound.

Sizing agent for carbon fibers, aqueous dispersion of sizing agent for carbon fibers, and sizing agent-adhered carbon fiber bundle

Growing community of inventors

Tokyo, Japan

Kenji Kaneta