# US 10,370,506 B2 · Carbon fiber thermoplastic resin prepreg, carbon fiber composite material and producing method

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- Number: US 10,370,506 B2
- Document ID: US10370506B2
- Status: Granted
- Kind: B2
- Application number: 14/387,008
- Filed: 2013-03-29
- Published: 2015-02-12
- Granted: 2019-08-06
- Earliest claimed: 2012-03-29
- Assignees: Mitsubishi Chemical Corporation
- Applicants: Mitsubishi Chemical Corporation
- Inventors: Masao Tomioka; Takahiro Hayashi; Saki Fujita; Takeshi Ishikawa; Keigo Yoshida; Takuya Teranishi; Atsushi Takahashi; Kenichi Watanabe; Morio Katagiri; Akinobu Sasaki; Masahiro Oosuka; Hiroshi Tategaki; Takayuki Kobayashi
- Web page: https://patentgrep.com/patent/US10370506B2

## CPC

- C08J 5/042: {with carbon fibres}
- B29B 11/16: comprising fillers or reinforcement {(non-woven fabrics per se D04H1/00, D04H3/00)}
- B29C 70/504: {using rollers or pressure bands (for corrugating B29C53/22)}
- B29C 70/506: {and impregnating by melting a solid material, e.g. sheet, powder, fibres (B29C70/508 takes precedence)}
- C08J 5/243: {using carbon fibres}
- B29C 70/50: for producing articles of indefinite length, e.g. prepregs, sheet moulding compounds [SMC] or cross moulding compounds [XMC]
- B29K 2023/12: {PP, i.e. polypropylene}
- B29K 2033/20: PAN, i.e. polyacrylonitrile
- B29K 2077/00: Use of {PA, i.e.} polyamides, e.g. polyesteramides {or derivatives thereof}, as moulding material
- B29K 2105/0872: {Prepregs}
- B29K 2233/20: PAN, i.e. polyacrylonitrile
- B29K 2307/04: Carbon
- B29L 2031/30: Vehicles, e.g. ships or aircraft, or body parts thereof {(vanes or blades B29L2031/08, air bags B29L2022/027)}
- C08J 2325/12: with unsaturated nitriles
- C08J 2333/10: Homopolymers or copolymers of methacrylic acid esters
- C08J 2333/12: Homopolymers or copolymers of methyl methacrylate
- C08J 2333/20: Homopolymers or copolymers of acrylonitrile (C08J2355/02 takes precedence)
- C08J 2369/00: Characterised by the use of polycarbonates; Derivatives of polycarbonates
- C08J 2377/02: Polyamides derived from omega-amino carboxylic acids or from lactams thereof (C08J2377/10 takes precedence)
- C08J 2377/06: Polyamides derived from polyamines and polycarboxylic acids (C08J2377/10 takes precedence)
- Y10T 428/2982: Particulate matter [e.g., sphere, flake, etc.]
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- B29B: PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## 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.

## Claims

### Claim 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.

### Claim 2 (depends on 1)

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.

### Claim 3 (depends on 1)

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.

### Claim 4 (depends on 1)

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

### Claim 5 (depends on 1)

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

### Claim 6 (depends on 1)

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=4πS/L2 (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.

### Claim 7 (depends on 6)

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 1×104 Pa·s; and
Vf represents a fiber volume percentage content (% by volume) of the carbon fiber thermoplastic resin prepreg.

### Claim 8 (depends on 6)

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.

### Claim 9 (depends on 6)

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

### Claim 10 (depends on 9)

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

### Claim 11 (depends on 6)

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

### Claim 12 (depends on 11)

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

### Claim 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.

### Claim 14 (depends on 13)

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