Method for producing fiber-reinforced composite material

Patent metadata

Field	Value
Publication number	US-2020079917-A1
Application number	US-201816611344-A
Country	US
Kind code	A1
Filing date	Apr 5, 2018
Priority date	May 10, 2017
Publication date	Mar 12, 2020
Grant date	—

Abstract

Provided is a method for producing a fiber-reinforced composite material exhibiting high heat resistance and excellent appearance quality. It is a method for producing a fiber-reinforced composite material, which includes disposing a prepreg containing a reinforced fiber being impregnated with an epoxy resin composition in a mold, pressurizing and heating the prepreg at 0.2 to 2.5 MPa and 130° C. to 200° C. as primary curing, and then further heating the prepreg at 210° C. to 270° C. for 10 minutes or more as secondary curing.

First claim

1 . A method for producing a fiber-reinforced composite material, the method comprising:
disposing a prepreg containing a reinforced fiber being impregnated with an epoxy resin composition in a mold; pressurizing and heating the prepreg at 0.2 to 2.5 MPa and 130° C. to 200° C. as primary curing; and then further heating the prepreg at 210° C. to 270° C. for 10 minutes or more as secondary curing.

2 . The method for producing a fiber-reinforced composite material according to claim 1 , wherein
an internal pressure applying member with a tube or bag-shape is disposed inside the prepreg, and a high pressure gas is introduced into the internal pressure applying member to apply pressure to the prepreg during the primary curing.

3 . The method for producing a fiber-reinforced composite material according to claim 1 or 2 , wherein the epoxy resin composition satisfies condition (1) below:
(1) a glass transition temperature of a cured product obtained by subjecting the epoxy resin composition to curing at 180° C. for 30 minutes and then to curing at 240° C. for 30 minutes is 220° C. or more.

4 . The method for producing a fiber-reinforced composite material according to any one of claims 1 to 3 , wherein the epoxy resin composition satisfies condition (2) below:
(2) a resin viscosity (η40) at 40° C. and a minimum viscosity (ηmin) satisfy a relational expression of:
2.5<Log(η40)−Log(ηmin)≤3.5.

5 . The method for producing a fiber-reinforced composite material according to any one of claims 1 to 4 , wherein the epoxy resin composition satisfies condition (3) below:
(3) a minimum viscosity when a viscosity is measured at a temperature raising rate of 1.5° C./min is in a range of 90° C. to 120° C. and a value of the minimum viscosity is 4.0 Pa·s or less.

6 . The method for producing a fiber-reinforced composite material according to any one of claims 1 to 5 , wherein the epoxy resin composition is an epoxy resin composition containing constituents [A] to [C] below:
[A] a tri- or higher functional epoxy resin having an aromatic ring
[B] an aromatic amine curing agent
[C] a curing accelerator

7 . The method for producing a fiber-reinforced composite material according to claim 6 , wherein the constituent [A] is contained in an amount of 80 parts by mass or more in 100 parts by mass of all epoxy resins in the epoxy resin composition.

8 . The method for producing a fiber-reinforced composite material according to claim 6 or 7 , wherein the constituent [A] includes at least one selected from the group consisting of tetraglycidyldiaminodiphenylmethane, a novolac epoxy resin, and an epoxy resin represented by Formula (i) below:

9 . The method for producing a fiber-reinforced composite material according to any one of claims 6 to 8 , wherein a number of active hydrogen groups in the constituent [B] with respect to a number of epoxy groups in all epoxy resins in the epoxy resin composition is 0.2 to 0.6.

10 . The method for producing a fiber-reinforced composite material according to any one of claims 6 to 9 , wherein the constituent [B] includes at least one selected from the group consisting of 4,4′-diaminodiphenyl sulfone and 3,3′-diaminodiphenyl sulfone.

11 . The method for producing a fiber-reinforced composite material according to any one of claims 1 to 10 , wherein the reinforced fiber is a carbon fiber.

Assignees

• Toray Industries

Inventors

• Sano Kentaro
• Mori Ayumi
• Kuroda Taiki
• Kamae Toshiya

Classifications

• B29C70/44 Primary

  using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding · CPC title

• B29K2105/0881

  unidirectional · CPC title

• B29K2307/04

  Carbon · CPC title

• C08J2363/00

  Characterised by the use of epoxy resins; Derivatives of epoxy resins · CPC title

• C08K7/06

  Elements · CPC title