Epoxy resin, epoxy resin composition, epoxy resin composition for carbon fiber-reinforced composite material, prepreg, and carbon fiber-reinforced composite material

Patent metadata

Field	Value
Publication number	US-11345777-B2
Application number	US-201917056423-A
Country	US
Kind code	B2
Filing date	Jul 23, 2019
Priority date	Jul 24, 2018
Publication date	May 31, 2022
Grant date	May 31, 2022

Abstract

Provided are an epoxy resin composition, a prepreg, a resin sheet, and a carbon fiber-reinforced composite material, which have high heat resistance, a high elastic modulus, low water absorption, and excellent flame resistance. This epoxy resin is a para-cresol novolac epoxy resin represented by General formula (1), in which a content ratio of components represented by n=1 as measured by gel permeation chromatography is less than 10% by area, and a content ratio of components represented by n=2 as measured by gel permeation chromatography is at least 1% by area and less than 40% by area.

(In the formula, plural R's each independently represent a C1-6 alkyl group, n represents a real number of 1 to 10, and G represents a substituted or unsubstituted glycidyl group.)

First claim

The invention claimed is:

1. An epoxy resin which is a para-cresol novolac epoxy resin represented by General Formula (1),
wherein a content ratio of components represented by n=1 as measured by gel permeation chromatography is at least 2% by area and less than 10% by area, and a content ratio of components represented by n=2 as measured by gel permeation chromatography is at least 10% by area and less than 40% by area,

(in the formula, plural R's each exist independently and represent a C1-6 alkyl group, n represents a real number of 1 to 10, and G represents a substituted or unsubstituted glycidyl group).

2. The epoxy resin according to claim 1 obtained through a reaction between epihalohydrins and para-cresol novolacs represented by General Formula (2),

(in the formula, plural R's each exist independently and represent a C1-6 alkyl group and n represents a real number of 1 to 10, provided that components represented by n=1 and n=2 are present).

3. The epoxy resin according to claim 2 ,
wherein, in the para-cresol novolacs represented by General Formula (2), a content ratio of components represented by n=1 as measured by gel permeation chromatography is at least 2% by area and less than 10% by area, and a content ratio of components represented by n=2 as measured by gel permeation chromatography is at least 10% by area and less than 50% by area.

4. The epoxy resin according to claim 2 ,
wherein, in the para-cresol novolacs represented by General Formula (2), a total content of the components represented by n=1 and 3 as measured by gel permeation chromatography is at least 5% by area and less than 30% by area, and a total content of the components represented by n=2 and 4 as measured by gel permeation chromatography is at least 20% by area and less than 65% by area.

5. An epoxy resin composition comprising: the epoxy resin according to claim 1 ; and a curing agent.

6. The epoxy resin composition according to claim 5 , wherein the curing agent is a phenolic curing agent.

7. The epoxy resin composition according to claim 5 , which is for a carbon fiber-reinforced composite material.

8. A resin sheet obtained by coating a support base with the epoxy resin composition according to claim 5 .

9. A prepreg obtained by impregnating the resin sheet according to claim 8 into carbon fibers.

10. A carbon fiber-reinforced composite material obtained by curing the prepreg according to claim 9 .

11. A prepreg obtained by impregnating the epoxy resin composition according to claim 5 into carbon fibers.

12. A carbon fiber-reinforced composite material obtained by curing the prepreg according to claim 11 .

13. An epoxy resin which is a para-cresol novolac epoxy resin represented by General Formula (1),
wherein a total content of components represented by n=1 and 3 as measured by gel permeation chromatography is at least 5% by area and less than 14% by area, and a total content of components represented by n=2 and 4 as measured by gel permeation chromatography is at least 25% by area and less than 50% by area,

(in the formula, plural R's each exist independently and represent a C1-6 alkyl group, n represents a real number of 1 to 10, and G represents a substituted or unsubstituted glycidyl group).

Assignees

• Nipponkayaku Kk
• Nippon Kayaku Kk

Inventors

• Kawano Yusuke
• Nakanishi Masataka
• Inoue Kazuma

Classifications

• C08J5/249

  characterised by the additives used in the prepolymer mixture · CPC title

• C08J5/243

  using carbon fibres · CPC title

• C08K7/06

  Elements · CPC title

• C08K3/04

  Carbon · CPC title

• C08G59/621 Primary

  Phenols · CPC title