# US 10,370,507 B2 · Carbon fiber thermoplastic resin prepreg, carbon fiber composite material and producing method

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- Number: US 10,370,507 B2
- Document ID: US10370507B2
- Status: Granted
- Kind: B2
- Application number: 15/499,128
- Filed: 2017-04-27
- Published: 2017-08-10
- Granted: 2019-08-06
- Earliest claimed: 2012-03-29
- Assignees: Mistubishi 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/US10370507B2

## 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 formed by impregnating a carbon fiber bundle formed from plural carbon fibers having an average single fiber fineness of 1.0 dtex to 2.4 dtex, with a thermoplastic resin composition, wherein a weight per area of the carbon fiber thermoplastic resin prepreg is 75 g/m2 or more, and a single fiber of the carbon fiber that constitutes 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 the following Formula (1):
20≤(FM/FS)≤40 (1)
wherein in Formula (1), FM represents the flexural modulus (MPa) of a resin plate formed from this thermoplastic resin composition only; and FS represents the 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 the following Formula (2):
25≤(FM/FS)≤35 (2)
wherein in Formula (2), FM represents the flexural modulus (MPa) of a resin plate formed from this thermoplastic resin composition only; and FS represents the flexural strength (MPa) of the resin plate.

### Claim 4 (depends on 1)

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

### Claim 5 (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 6 (depends on 1)

The carbon fiber thermoplastic resin prepreg according to claim 1, wherein the degree of circularity of a single fiber of the carbon fiber that constitutes the carbon fiber bundle is 0.70 to 0.90,
provided that the degree of circularity is determined by the following Formula (4), wherein S represents the cross-sectional area of the single fiber; and L represents the circumferential length of a cross-section of the single fiber:
Degree of circularity=4πS/L2 (4).

### Claim 7 (depends on 6)

The carbon fiber thermoplastic resin prepreg according to claim 6, satisfying the following Formula (5):
β×(Tc−25)×(100−Vf)>0.5 (5)
wherein β represents the coefficient of linear expansion (1/° C.) of the thermoplastic resin composition; Tc represents the lower limit temperature for molding (° C.) of the thermoplastic resin composition, while regarding the lower limit temperature for molding, in a case in which the thermoplastic resin composition has a melting point, the lower limit temperature for molding represents the melting point of the composition, and in a case in which the thermoplastic resin composition does not have a melting point, the lower limit temperature for molding represents a temperature at which the viscosity of the composition is 1×104 Pa·s; and Vf represents the 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 kind of resin 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 flakes, obtained using the carbon fiber prepreg according to claim 6.

### Claim 10 (depends on 9)

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

### Claim 11 (depends on 6)

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

### Claim 12 (depends on 11)

An automobile part, obtained 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 a step of impregnating a PAN-based carbon fiber bundle having an average single fiber fineness of from 1.0 dtex to 2.4 dtex, with a thermoplastic resin composition, and thereby obtaining a carbon fiber prepreg,
wherein the thermoplastic resin composition is a thermoplastic resin composition that satisfies the following Formula (3):
20≤(FM/FS)≤40 (3)
wherein in Formula (3), FM represents the flexural modulus (MPa) of a resin plate formed from this thermoplastic resin composition only; and FS represents the flexural strength (MPa) of the resin plate, and wherein
a weight per area of the carbon fiber thermoplastic resin prepreg is 75 g/m2 or more, and a single fiber of the carbon fiber that constitutes the PAN-based 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 for producing the carbon fiber thermoplastic resin prepreg according to claim 13, wherein the thermoplastic resin composition is in a film form.