IP Library Granted Patent US 12,692,354
Granted Patent B2
US 12,692,354 · App. 18/693,333 · Granted Jul 28, 2026

Carbon fiber reinforced composite and production method of carbon fiber reinforced composite

Inventors: Ayako Oota (Shiga, JP); Haruka Yoshida (Shiga, JP)
Assignee: SEKISUI CHEMICAL CO., LTD.
C08J5/243C08L63/00B29C70/42B29K2029/14B29K2063/00B29K2105/0005B29K2105/0094B29K2105/0872B29K2307/04C08J2363/02C08J2429/14
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Quick Facts
Patent No.
US 12,692,354
App. No.
18/693,333
Granted
Jul 28, 2026
Kind
B2
Abstract

The present invention provides a carbon-fiber-reinforced composite that can reduce the curing time and achieve high mechanical strength while reducing resin bleeding, and a method for producing a carbon-fiber-reinforced composite. Provided is a carbon-fiber-reinforced composite containing: carbon fibers, an epoxy resin, a curing agent, and a thermoplastic resin, wherein a mixture of the epoxy resin and the thermoplastic resin has a ratio of viscosity at 30° C. to viscosity at 90° C. (viscosity at 30° C./viscosity at 90° C.) of less than 100.

Claims (24)

1 . A carbon-fiber-reinforced composite comprising:

carbon fibers;

an epoxy resin;

a curing agent; and

a thermoplastic resin,

wherein a mixture of the epoxy resin and the thermoplastic resin has a ratio of viscosity at 30° C. to viscosity at 90° C. (viscosity at 30° C./viscosity at 90° C.) of less than 100,

the thermoplastic resin is a polyvinyl acetal resin, and

the polyvinyl acetal resin has a hydroxy group content of 16.0 mol % or more and 45.0 mol % or less.

2 . The carbon-fiber-reinforced composite according to claim 1 ,

wherein the thermoplastic resin has a glass transition temperature of 60° C. or higher.

3 . The carbon-fiber-reinforced composite according to claim 1 ,

wherein the polyvinyl acetal resin has structural units represented by the following formula (1):

wherein each R 1 represents an alkyl group having a carbon number of 1 or greater, and R 1 s may be the same as or different from each other.

4 . The carbon-fiber-reinforced composite according to claim 1 , which is used as a prepreg.

5 . The carbon-fiber-reinforced composite according to claim 1 ,

wherein the epoxy resin contains a bisphenol A epoxy resin.

6 . The carbon-fiber-reinforced composite according to claim 1 , which contains 0.01 parts by weight or more and 40 parts by weight or less of the thermoplastic resin relative to 100 parts by weight of the epoxy resin.

7 . The carbon-fiber-reinforced composite according to claim 1 , which contains 0.5 parts by weight or more and 300 parts by weight or less of the epoxy resin relative to 100 parts by weight of the carbon fibers.

8 . A method for producing a carbon-fiber-reinforced composite, comprising at least the steps of:

forming a resin composition containing an epoxy resin, a curing agent, and a thermoplastic resin; and

forming a composite of the resin composition with carbon fibers,

wherein a mixture of the epoxy resin and the thermoplastic resin has a ratio of viscosity at 30° C. to viscosity at 90° C. (viscosity at 30° C./viscosity at 90° C.) of less than 100,

the thermoplastic resin is a polyvinyl acetal resin, and

the polyvinyl acetal resin has a hydroxy group content of 16.0 mol % or more and 45.0 mol % or less.