Epoxy resin, method for producing epoxy resin, curable resin composition, cured product, fiber reinforced composite material, and molded article

Patent metadata

Field	Value
Publication number	US-10047190-B2
Application number	US-201515508483-A
Country	US
Kind code	B2
Filing date	Aug 27, 2015
Priority date	Sep 3, 2014
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

Provided are a curable resin composition capable of providing excellent heat resistance and toughness for a cured product, in which these physical properties are less deteriorated even in a case of being exposed to humidity and heat conditions, and a cured product, a fiber reinforced composite material, and a molded article thereof. The curable resin composition includes an epoxy resin and a curing agent, in which the epoxy resin is an epoxy resin obtained by the polyglycidyl-etherification of a phenol novolac resin. The phenol novolac resin contains bisphenol F having different binding sites, and in the bisphenol F components, the content of the [o, p′] conjugate is in a range of 30% to 45% relative to the total of the [o, p′] conjugate+the [o, o′] conjugate+the [p, p′] conjugate in terms of the area ratio according to a liquid chromatography measurement.

First claim

The invention claimed is:

1. An epoxy resin produced by the polyglycidyl-etherification of a phenol novolac resin, wherein
the phenol novolac resin contains at least one bisphenol F represented by any one of the following Structural Formulae (1-1) to (1-3) as a bisphenol F component:

with the content of the [o, p′] conjugate (x1) represented by Structural Formula (1-1) in the bisphenol F component being in a range of 30% to 45% relative to the total of the [o, p′] conjugate (x1)+the [o, o′] conjugate (x2)+the [p, p′] conjugate (x3) in terms of the area ratio according to a liquid chromatography measurement, wherein
the content of the bisphenol F component in the phenol novolac resin is from 10% to 60% in terms of the area ratio according to a GPC measurement.

2. The epoxy resin according to claim 1 , wherein the content of the [o, p′] conjugate (x1) represented by Structural Formula (1-1) in the bisphenol F component contained in the phenol novolac resin is from 30% to 45% and the content of the [o, o′] conjugate (x2) represented by Structural Formula (1-2) in the bisphenol F component contained in the phenol novolac resin is from 15% to 50% in terms of the area ratios according to a liquid chromatography measurement.

3. The epoxy resin according to claim 1 , wherein the content of the trinuclear bodies in the phenol novolac resin is from 0% to 10% in terms of the area ratio according to a GPC measurement.

4. The epoxy resin according to claim 1 , which is produced by a method which comprises causing phenols to react with formaldehydes at a ratio of phenols:formaldehydes=35:1 to 25:1 (molar ratio) by an acid catalyst, performing the reaction under a condition for distilling excess phenols to obtain bisphenol F (A), 90% or more of which is a body with n=0, causing the obtained bisphenol F (A) to react with formaldehydes under a condition of bisphenol F (A):formaldehydes=1:0.20 to 1:0.65 (molar ratio) to obtain a phenol novolac resin, and causing the phenol novolac resin to react with epihalohydrin.

5. The epoxy resin according to claim 1 , which is produced by a method which comprises causing phenols to react with formaldehydes at a ratio of phenols:formaldehydes=35:1 to 25:1 (molar ratio) by an acid catalyst, performing the reaction under a condition for distilling excess phenols, further performing distillation by thin-film molecular distillation to obtain bisphenol F (B), to obtain bisphenol F (B), 99% or more of which is a body with n=0, causing the obtained bisphenol F (B) to react with formaldehydes under a condition of bisphenol F (B):formaldehydes=1:0.20 to 1:0.65 (molar ratio) to obtain a phenol novolac resin, and causing the phenol novolac resin to react with epihalohydrin.

6. A method for producing an epoxy resin, comprising:
causing phenols to react with formaldehydes at a ratio of phenols:formaldehydes=35:1 to 25:1 (molar ratio) by an acid catalyst, performing the reaction under a condition for distilling excess phenols to obtain bisphenol F (A), 90% or more of which is a body with n=0, causing the obtained bisphenol F (A) to react with formaldehydes under a condition of bisphenol F (A):formaldehydes=1:0.20 to 1:0.65 (molar ratio) to obtain a phenol novolac resin, and causing the phenol novolac resin to react with epihalohydrin.

7. A method for producing an epoxy resin, comprising:
causing phenols to react with formaldehydes at a ratio of phenols:formaldehydes=35:1 to 25:1 (molar ratio) by an acid catalyst present in a range of 0.1% to 3.0%, performing the reaction under a condition for distilling excess phenols, further performing distillation by thin-film molecular distillation to obtain bisphenol F (B), to obtain bisphenol F (B), 99% or more of which is a body with n=0, causing the obtained bisphenol F (B) to react with formaldehydes under a condition of bisphenol F (B):formaldehydes=1:0.20 to 1:0.65 (molar ratio) to obtain a phenol novolac resin, and causing the phenol novolac resin to react with epihalohydrin.

8. A curable resin composition comprising:
the epoxy resin claim 1 ; and
a curing agent.

9. The curable resin composition according to claim 8 , wherein the curing agent is a dicyandiamide compound.

10. A cured product formed by curing the curable resin composition according to claim 8 .

11. The curable resin composition according to claim 8 , further comprising a reinforcing fiber.

12. A cured product formed by curing the curable resin composition according to claim 11 .

13. The epoxy resin according to claim 1 , wherein the content of the bisphenol F component in the phenol novolac resin is from 10% to less than 50% in terms of the area ratio according to a GPC measurement.

Assignees

• Dainippon Ink & Chemicals

Inventors

• Morinaga Kunihiro
• Kimura Makoto
• Hayashi Koji
• Nakamura Takamitsu

Classifications

• C08G59/58

  with polycarboxylic acids or with anhydrides, halides, or low-molecular-weight esters thereof · CPC title

• C08G59/60 Primary

  with amides · CPC title

• C08J2363/02

  Polyglycidyl ethers of bis-phenols · CPC title

• C08G59/621

  Phenols · CPC title

• C08G59/08

  from phenol-aldehyde condensates · CPC title