Carbon fiber thermoplastic resin prepreg, carbon fiber composite material and producing method

Patent metadata

Field	Value
Publication number	US-10370506-B2
Application number	US-201314387008-A
Country	US
Kind code	B2
Filing date	Mar 29, 2013
Priority date	Mar 29, 2012
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

Provided are a carbon fiber thermoplastic resin prepreg which is a carbon fiber prepreg obtained by impregnating a PAN-based carbon fiber in which the average fiber fineness of a single fiber is 1.0 dtex to 2.4 dtex with a thermoplastic resin, wherein the thermoplastic resin satisfies 20≤(FM/FS)≤40 (where FM: flexural modulus (MPa) of a resin sheet comprising only the thermoplastic resin, and FS: flexural strength (MPa) of the resin sheet), a method for manufacturing the same, and a carbon fiber composite material employing the carbon fiber prepreg.

First claim

The invention claimed is:

1. A carbon fiber thermoplastic resin prepreg obtained by a process comprising: impregnating a carbon fiber bundle of plural carbon fibers having an average single fiber fineness of from 1.1 dtex to 2.4 dtex with a thermoplastic resin composition, wherein a single fiber of the carbon fiber in the carbon fiber bundle has plural surface asperity structures extending over 2 μm or more in the fiber longitudinal direction, and the difference of elevation between the peak and the bottom (Rp−v) in a region having a circumferential length of the single fiber of 2000 nm×a length in the fiber axial direction of 2000 nm is in the range of 60 nm to 200 nm.

2. The carbon fiber thermoplastic resin prepreg according to claim 1 , wherein the thermoplastic resin composition is a thermoplastic resin that satisfies Formula (1):
20≤(FM/FS)≤40  (1)

where,
FM represents a flexural modulus (MPa) of a resin plate formed from the thermoplastic resin composition only; and
FS represents a flexural strength (MPa) of the resin plate.

3. The carbon fiber thermoplastic resin prepreg according to claim 1 , wherein the thermoplastic resin composition is a thermoplastic resin composition that satisfies Formula (2):
25≤(FM/FS)≤35  (2)

where,
FM represents a flexural modulus (MPa) of a resin plate formed from the thermoplastic resin composition only; and
FS represents a flexural strength (MPa) of the resin plate.

4. The carbon fiber thermoplastic resin prepreg according to claim 1 , wherein the carbon fiber bundle is a PAN-based carbon fiber bundle.

5. A carbon fiber composite material formed from the carbon fiber thermoplastic resin prepreg according to claim 1 .

6. The carbon fiber thermoplastic resin prepreg according to claim 1 , wherein a degree of circularity of a single fiber of the carbon fibers in the carbon fiber bundle is from 0.70 to 0.90,
provided that the degree of circularity is determined by Formula (4):
Degree of circularity=4 πS/L 2   (4)

where
S represents an area of a cross-section of the single fiber; and
L represents a circumferential length of the cross-section of the single fiber.

7. The carbon fiber thermoplastic resin prepreg according to claim 6 , satisfying Formula (5):
β×( Tc− 25)×(100 −Vf )>0.5  (5)

where
β represents a coefficient of linear expansion (1/° C.) of the thermoplastic resin composition;
Tc represents a lower limit temperature for molding (° C.) of the thermoplastic resin composition, when the thermoplastic resin composition has a melting point, the lower limit temperature for molding is the melting point of the composition, and when the thermoplastic resin composition does not have a melting point, the lower limit temperature for molding is a temperature at which the composition has a viscosity of 1×10 4 Pa·s; and
Vf represents a fiber volume percentage content (% by volume) of the carbon fiber thermoplastic resin prepreg.

8. The carbon fiber thermoplastic resin prepreg according to claim 6 , wherein the thermoplastic resin composition is at least one selected from the group consisting of a polypropylene resin, a polyamide resin, a modified resin of a polypropylene resin, and a modified resin of a polyamide resin.

9. A carbon fiber thermoplastic resin prepreg flake, obtained by using the carbon fiber thermoplastic resin prepreg according to claim 6 .

10. A carbon fiber-reinforced composite material, obtained by using the carbon fiber thermoplastic resin prepreg flake according to claim 9 .

11. A carbon fiber-reinforced composite material, obtained by using the carbon fiber thermoplastic resin prepreg according to claim 6 .

12. An automobile part, obtained by using the carbon fiber-reinforced composite material according to claim 11 .

13. A method for producing a carbon fiber thermoplastic resin prepreg, the method comprising: impregnating a PAN-based carbon fiber bundle having an average single fiber fineness of from 1.1 dtex to 2.4 dtex with a thermoplastic resin composition, thereby obtaining the carbon fiber thermoplastic resin prepreg,
wherein the thermoplastic resin composition is a thermoplastic resin composition that satisfies Formula (3):
20≤(FM/FS)≤40  (3)

where, FM represents a flexural modulus (MPa) of a resin plate formed from the thermoplastic resin composition only; and FS represents a flexural strength (MPa) of the resin plate, and
a single fiber of the carbon fiber in the carbon fiber bundle has plural surface asperity structures extending over 2 μm or more in the fiber longitudinal direction, and the difference of elevation between the peak and the bottom (Rp−v) in a region having a circumferential length of the single fiber of 2000 nm×a length in the fiber axial direction of 2000 nm is in the range of 60 nm to 200 nm.

14. The method according to claim 13 , wherein the thermoplastic resin composition is a film.

Assignees

• Mitsubishi Chem Corp

Inventors

• Tomioka Masao
• Hayashi Takahiro
• Fujita Saki
• Ishikawa Takeshi
• Yoshida Keigo
• Teranishi Takuya
• Takahashi Atsushi
• Watanabe Kenichi
• KATAGIRI Morio
• Sasaki Akinobu
• Oosuka Masahiro
• TATEGAKI Hiroshi
• Kobayashi Takayuki

Classifications

• C08J5/042 Primary

  with carbon fibres · CPC title

• B29K2023/12

  PP, i.e. polypropylene · CPC title

• C08J2377/06

  Polyamides derived from polyamines and polycarboxylic acids (C08J2377/10 takes precedence) · CPC title

• C08J5/24

  Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs · CPC title

• B29K2307/04

  Carbon · CPC title