Prepreg, prepreg laminate, and fiber-reinforced composite material

Patent metadata

Field	Value
Publication number	US-11760053-B2
Application number	US-201917267621-A
Country	US
Kind code	B2
Filing date	Sep 11, 2019
Priority date	Sep 18, 2018
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

Abstract

A prepreg which is suitable for producing a fiber-reinforced composite material in a short period of time without using an autoclave, can produce a fiber-reinforced composite material in which the occurrence of voids is suppressed and excellent impact resistance is achieved, and has excellent handling properties; and a fiber-reinforced composite material using the prepreg. This prepreg is a prepreg in which a reinforcing fiber [A] arranged in layers is partially impregnated with an epoxy resin composition containing an epoxy resin [B] and a curing agent [C], wherein the impregnation rate φ is 30-95%, and a thermoplastic resin [D] insoluble in the epoxy resin [B] is unevenly distributed on both surfaces of the prepreg. In addition, in the layers of the reinforcing fiber [A], epoxy resin composition-unimpregnated portions are localized on one surface of the prepreg, and the localization parameter a, which defines the degree of localization, is in the range of 0.10<σ<0.45.

First claim

The invention claimed is:

1. A prepreg comprising:
reinforced fibers [A] arranged in a layer form,
an epoxy resin composition containing an epoxy resin [B] and a hardener [C], the epoxy resin composition being partially impregnated into the reinforced fibers [A], and
a thermoplastic resin [D] that is insoluble in the epoxy resin [B] and is localized at surfaces on both sides of the prepreg,
wherein the prepreg has a degree of impregnation φ with the epoxy resin composition of 30 to 95%,
in a layer of the reinforced fibers [A], a region un-impregnated with the epoxy resin composition shifts to a side of either of the surfaces of the prepreg, and
the prepreg has a shift parameter a that defines a degree of the shift in a range of 0.10<σ<0.45.

2. The prepreg according to claim 1 , having a penetration coefficient K in an in-plane direction of 1.1×(1−φ/100)×10 −13 [m 2 ] or more.

3. The prepreg according to claim 1 , wherein the reinforced fibers [A] are continuous fibers that are arranged unidirectionally.

4. The prepreg according to claim 1 , wherein the reinforced fibers [A] are in a form of a woven fabric.

5. The prepreg according to claim 1 , having a content of the thermoplastic resin [D] that is equal at both the surfaces of the prepreg.

6. A prepreg with a release sheet comprising:
the prepreg according to claim 1 , and
a release sheet attached to at least one of the surfaces of the prepreg.

7. The prepreg with a release sheet according to claim 6 , wherein the release sheet is release paper, and the release paper is attached to a side of the surface of the prepreg to which the region un-impregnated with the epoxy resin composition does not shift.

8. The prepreg with a release sheet according to claim 6 , wherein the release sheet is a plastic film, and the plastic film is attached to a side of the surface of the prepreg to which the region un-impregnated with the epoxy resin composition shifts.

9. A prepreg laminate comprising a laminate of a plurality of the prepregs according to claim 1 , the prepregs being laminated so that the sides to which the region un-impregnated with the epoxy resin composition shifts are all on an upper side or all on a lower side.

10. A fiber-reinforced composite material comprising a cured product of the prepreg laminate according to claim 9 .

11. A fiber-reinforced composite material comprising a cured product of the prepreg according to claim 1 .

Assignees

• Toray Industries

Inventors

• Yamane Takuya
• Sato Narumichi
• Kawamoto Shiori
• Tabayashi Miyuki

Classifications

• C08J5/243 Primary

  using carbon fibres · CPC title

• B32B5/024 Primary

  Woven fabric · CPC title

• C08J5/249

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

• C08J2363/00

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

• C08J2477/00

  Characterised by the use of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Derivatives of such polymers · CPC title