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

Patent metadata

Field	Value
Publication number	US-10577455-B2
Application number	US-201816034124-A
Country	US
Kind code	B2
Filing date	Jul 12, 2018
Priority date	Jan 19, 2016
Publication date	Mar 3, 2020
Grant date	Mar 3, 2020

Abstract

This epoxy resin composition contains an epoxy resin (A) having at least three glycidyl groups in the molecule, an epoxy resin (B) having at least one sulfur atom in the molecule, and an imidazole compound (C) containing at least one of 2-phenyl-4,5-dihydroxymethyl imidazole and 2-phenyl-4-methyl-5-hydroxymethyl imidazole.

First claim

The invention claimed is:

1. An epoxy resin composition, comprising:
(A) at least one epoxy resin having at least three glycidyl groups;
(B) at least one epoxy resin having at least one sulfur atom;
(C) at least one of 2-phenyl-4,5-dihydroxymethylimidazole represented by the following Formula (1) and 2-phenyl-4-methyl-5-hydroxymethylimidazole represented by the following Formula (2);
(D) at least one selected from the group consisting of a bisphenol A diglycidyl ether, a bisphenol F diglycidyl ether and a monofunctional epoxy resin, in a positive amount of up to 15% by mass with respect to a total mass of all epoxy resins included in the epoxy resin composition; and
(E) dicyandiamide:

wherein (A) does not include an epoxy resin having at least one sulfur atom.

2. The epoxy resin composition according to claim 1 , wherein (B) comprises a reaction product between an epoxy resin and an amine compound having at least one sulfur atom.

3. The epoxy resin composition according to claim 1 , wherein the content of (A) is 25% to 85% by mass, and the content of (B) is 10% to 70% by mass, with respect to the total mass of all the epoxy resins included in the epoxy resin composition.

4. The epoxy resin composition according to claim 1 , comprising 2-phenyl-4,5-dihydroxymethylimidazole as (C).

5. The epoxy resin composition according to claim 1 , wherein the epoxy resin composition has a pot life upon storage at 21° C. of four weeks or longer.

6. The epoxy resin composition according to claim 1 , wherein a half-value width of a reaction exotherm based on differential scanning calorimetric measurement of the epoxy resin composition is 18° C. or less.

7. The epoxy resin composition according to claim 1 , wherein a cure degree based on differential scanning calorimetric measurement of a cured product obtainable by heating the epoxy resin composition for 30 minutes at 150° C. is 94% or higher.

8. The epoxy resin composition according to claim 1 , wherein (A) includes at least one selected from the group consisting of a tetraglycidylamine epoxy resin, a triglycidylaminophenol epoxy resin, a triglycidyl ether epoxy resin, a phenol novolac epoxy resin, a cresol-novolac epoxy resin, and a polyfunctional novolac epoxy resin.

9. The epoxy resin composition according to claim 1 , wherein (A) includes tris(hydroxyphenyl)methane triglycidyl ether.

10. The epoxy resin composition according to claim 1 , wherein (A) includes at least one selected from the group consisting of tris(hydroxyphenyl)methane triglycidyl ether, tetraglycidyl diaminodiphenyl methane, and triglycidyl p-aminophenol.

11. The epoxy resin composition according to claim 1 , wherein (A) includes at least one selected from the group consisting of tris(hydroxyphenyl)methane triglycidyl ether and tetraglycidyl diaminodiphenyl methane.

12. The epoxy resin composition according to claim 1 , wherein (A) includes at least one selected from the group consisting of tetraglycidyl diaminodiphenyl methane and triglycidyl p-aminophenol.

13. The epoxy resin composition according to claim 1 , further comprising carbon black.

14. The epoxy resin composition according to claim 1 , wherein a glass transition point of a cured product obtained by heating the epoxy resin composition for 30 minutes at 150° C. is 180° C. or higher, where the glass transition point is determined by a dynamic viscoelasticity measurement.

15. The epoxy resin composition according to claim 14 , wherein the glass transition point is 185° C. or higher.

16. The epoxy resin composition according to claim 14 , wherein the glass transition point is 190° C. or higher.

17. A cured product obtained by heating the epoxy resin composition of claim 1 for 30 min at 150° C. and having a glass transition point of 180° C. or higher, wherein the glass transition point is determined by a dynamic viscoelasticity measurement.

18. A prepreg for a fiber-reinforced composite material, comprising the epoxy resin composition according to claim 1 and reinforcing fibers.

19. A fiber-reinforced composite material, obtained by curing the prepreg for a fiber-reinforced composite material according to claim 18 .

Assignees

• Mitsubishi Chem Corp

Inventors

• Nohara Atsushi
• Suzumura Yasushi

Classifications

• C08G59/3227

  Compounds containing acyclic nitrogen atoms · CPC title

• C08G59/302

  containing sulfur · CPC title

• C08G59/38

  together with di-epoxy compounds · CPC title

• C08G59/60

  with amides · CPC title

• C08G59/5073

  having two nitrogen atoms in the ring · CPC title