# US 10,501,605 B2 · Carbon fiber-reinforced resin composition, method for manufacturing carbon fiber-reinforced resin composition, molding material, method for manufacturing molding material, and carbon fiber-reinforced resin molded article

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- Number: US 10,501,605 B2
- Document ID: US10501605B2
- Status: Granted
- Kind: B2
- Application number: 14/435,793
- Filed: 2013-08-06
- Published: 2015-09-03
- Granted: 2019-12-10
- Earliest claimed: 2012-10-18
- Assignees: Toray Industries, Inc.
- Applicants: Toray Industries, Inc.
- Inventors: Tomoko Ichikawa; Atsuki Tsuchiya; Makoto Endo
- Web page: https://patentgrep.com/patent/US10501605B2

## CPC

- B29B 7/90: Fillers or reinforcements {, e.g. fibres}
- C08K 9/04: Ingredients treated with organic substances {(treated with macromolecular compounds C08K9/08)}
- B29B 7/002: {Methods (chemical aspects C08J3/00)}
- B29B 7/88: Adding charges {, i.e. additives}
- B29B 9/12: characterised by structure or composition
- B29B 9/14: fibre-reinforced
- B29B 11/16: comprising fillers or reinforcement {(non-woven fabrics per se D04H1/00, D04H3/00)}
- B29B 15/105: {of reinforcement of definite length with a matrix in solid form, e.g. powder, fibre or sheet form (calendering B29C70/506)}
- C08J 5/042: {with carbon fibres}
- C08J 5/06: using pretreated fibrous materials
- C08J 5/248: {using pre-treated fibres}
- C09C 3/08: Treatment with low-molecular-weight {non-polymer} organic compounds {(C09C3/006, C09C3/048 take precedence)}
- D06M 13/11: Compounds containing epoxy groups or precursors thereof
- D06M 15/55: Epoxy resins
- B29B 7/48: with intermeshing devices, e.g. screws
- B29B 9/06: in the form of filamentary material, e.g. combined with extrusion
- B29C 70/06: Fibrous reinforcements only
- B29K 2063/00: Use of {EP, i.e.} epoxy resins {or derivatives thereof}, as moulding material
- B29K 2307/04: Carbon
- D06M 2101/40: Fibres of carbon
- Y10T 428/2918: including free carbon or carbide or therewith [not as steel]
- 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
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- 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)
- C09C: TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES (treatment of materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone C04B14/00, C04B18/00, C04B20/00); PREPARATION OF CARBON BLACK {; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS}
- D06M: TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- 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
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A carbon fiber-reinforced resin composition of the present invention includes: sizing agent-coated carbon fibers in which carbon fibers are coated with a sizing agent; and a matrix resin. The sizing agent includes at least an aliphatic epoxy compound (A) and an aromatic epoxy compound (B1) as an aromatic compound (B). The sizing agent-coated carbon fibers have a ratio (a)/(b) of 0.50 to 0.90 where (a) is the height (cps) of a component having a binding energy (284.6 eV) attributed to CHx, C—C, and C═C and (b) is the height (cps) of a component having binding energy (286.1 eV) attributed to C—O in a C1s core spectrum of the surface of the sizing agent measured by X-ray photoelectron spectroscopy at a photoelectron takeoff angle of 15°.

## Claims

### Claim 1

A carbon fiber-reinforced resin composition comprising:
(i) sizing agent-coated carbon fibers in which carbon fibers are coated with a sizing agent; and
(ii) a matrix resin comprising a thermoplastic resin or a radical polymerizable resin; wherein
the sizing agent comprises at least:
an aliphatic epoxy compound (A), wherein the aliphatic epoxy compound (A) is a polyether polyepoxy compound having two or more epoxy groups in a molecule and/or a polyol polyepoxy compound having two or more epoxy groups in a molecule;
an aromatic epoxy compound (B1) as an aromatic compound (B), wherein the aromatic epoxy compound (B1) is a bisphenol A epoxy compound or a bisphenol F epoxy compound;
a mass ratio of the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) in the sizing agent is 60/40 to 80/20;
each of the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) has a surface tension of 37 mJ/m2 to 45 mJ/m2 at 125° C.;
the difference in the surface tensions between the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) is 3 mJ/m2 or less at 125° C.;
and
the sizing agent-coated carbon fibers have a ratio (a)/(b) of 0.50 to 0.90 where (a) is a height (cps) of a component having a binding energy (284.6 eV) attributed to CHx, C—C, and C═C and (b) is a height (cps) of a component having binding energy (286.1 eV) attributed to C—O in a C1s core spectrum of a surface of the sizing agent of the sizing agent-coated carbon fibers measured by X-ray photoelectron spectroscopy using AlKα1,2 as an X-ray source at a photoelectron takeoff angle of 15°.

### Claim 2 (depends on 1)

The carbon fiber-reinforced resin composition according to claim 1, wherein a water content of the sizing agent-coated carbon fibers is 0.010% by mass to 0.030% by mass.

### Claim 3 (depends on 1)

The carbon fiber-reinforced resin composition according to claim 1, wherein the aliphatic epoxy compound (A) is a glycidyl ether epoxy compound obtained by causing epichlorohydrin to react with a compound selected from ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polypropylene glycol, trimethylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, polybutylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, glycerol, diglycerol, polyglycerol, trimethyloipropane, pentaerythritol, sorbitol, and arabitol.

### Claim 4 (depends on 1)

The carbon fiber-reinforced resin composition according to claim 1, wherein
in the sizing agent-coated carbon fibers, values (I) and (II) determined by a ratio (a)/(b) where
(a) is the height (cps) of a component having a binding energy (284.6 eV) attributed to CHx, C—C, and C═C, and
(b) is the height (cps) of a component having binding energy (286.1 eV) attributed to C—O in a C1s core spectrum of the sizing agent-coated carbon fibers measured by X-ray photoelectron spectroscopy using an X-ray of 400 eV at a photoelectron takeoff angle of 55° satisfy a relation (III):
0.50≤(I)≤0.90 and 0.60<(II)/(I)<1.0 (III)
where
(I) is a value of (a)/(b) of the surface of the sizing agent-coated carbon fibers before ultrasonic treatment, and
(II) is a value of (a)/(b) of the surface of the sizing agent-coated carbon fibers after washing to reduce an attached amount of the sizing agent to 0.09% by mass to 0.20% by mass by the ultrasonic treatment of the sizing agent-coated carbon fibers in an acetone solvent.

### Claim 5 (depends on 1)

The carbon fiber-reinforced resin composition according to claim 1, wherein the surface of the sizing agent-coated carbon fibers after washing to reduce the attached amount of the sizing agent on the surface of the sizing agent-coated carbon fibers to 0.09% by mass to 0.20% by mass by the ultrasonic treatment in a solvent that dissolves the matrix resin constituting the carbon fiber-reinforced resin composition has a ratio of (a)/(b) of 0.30 to 0.70 where (a) is the height (cps) of a component having a binding energy (284.6 eV) attributed to CHx, C—C, and C═C and (b) is the height (cps) of a component having binding energy (286.1 eV) attributed to C—O in a C1s core spectrum of the surface of the sizing agent-coated carbon fibers measured by X-ray photoelectron spectroscopy using an X ray of 400 eV at a photoelectron takeoff angle of 55°.

### Claim 6 (depends on 1)

The carbon fiber-reinforced resin composition according to claim 1, wherein a surface carboxy group concentration (COOH/C) is 0.003 to 0.015 and a surface hydroxy group concentration (COH/C) is 0.001 to 0.050 where the surface carboxy group concentration and the surface hydroxy group concentration are determined by chemical modification X-ray photoelectron spectroscopy of the carbon fibers.

### Claim 7 (depends on 1)

The carbon fiber-reinforced resin composition according to claim 1, wherein the matrix resin is one or more resins selected from a polyarylene sulfide resin, a polyether ether ketone resin, a polyphenylene ether resin, a polyoxymethylene resin, a polyester resin, a polycarbonate resin, a polystyrene resin, a polyolefin resin, and a polyamide.

### Claim 8 (depends on 1)

The carbon fiber-reinforced resin composition according to claim 1, wherein
the sizing agent-coated carbon fibers are formed by attaching the sizing agent in an amount of 0.1 parts by mass to 10.0 parts by mass relative to 100 parts by mass of the carbon fibers, and
the carbon fiber-reinforced resin composition comprises the sizing agent-coated carbon fibers in an amount of 1% by mass to 80% by mass and the matrix resin in an amount of 20% by mass to 99% by mass.

### Claim 9 (depends on 1)

A method for manufacturing the carbon fiber-reinforced resin composition according to claim 1, the method comprising:
coating carbon fibers with a sizing agent comprising at least the aliphatic epoxy compound (A) in an amount of 35% by mass to 65% by mass and an aromatic compound (B) in an amount of 35% by mass to 60% by mass relative to a total amount of the sizing agent except a solvent to produce sizing agent-coated carbon fibers; and
adding the sizing agent-coated carbon fibers to a matrix resin.

### Claim 10 (depends on 1)

The carbon fiber-reinforced resin composition according to claim 1, wherein
the carbon fiber-reinforced resin composition is any one of the following forms of molding materials (H), (J1), (J2), and (K):
the molding material (H): a molding material that has a cylindrical shape and in which the carbon fibers are almost parallelly arranged in an axis center direction and a length of the carbon fibers has substantially the same length as a length of the molding material,
the molding material (J1): a molding material in which the carbon fibers are in a form of single fiber and that is substantially oriented in two dimensions,
the molding material (J2): a molding material in which the carbon fibers are in a bundle-like form and that is substantially oriented in two dimensions, and
the molding material (K): a prepreg.

### Claim 11 (depends on 10)

A molding material that is the molding material (H) according to claim 10, comprising:
any one of the following structures (L), (M), and (N):
(L): a core-sheath structure formed by covering a circumference of a structure Y with a structure X where the structure Y comprising the carbon fibers as a main component is a core structure and the structure X comprising the matrix resin as a main component is a sheath structure,
(M): a structure having a length of 1 mm to 50 mm, and
(N): a structure having a form of a long fiber pellet, wherein
the molding material (H) comprises an impregnation promoter (D) in an amount of 0.1 parts by mass to 100 parts by mass relative to 100 parts by mass of the carbon fibers and is made by impregnating a part of or whole of the impregnation promoter (D) into the carbon fibers.

### Claim 12 (depends on 10)

A method for manufacturing the molding material (H) according to claim 10, the method comprising:
at least:
coating continuous carbon fibers with a sizing agent comprising at least an aliphatic epoxy compound (A) in an amount of 35% by mass to 65% by mass and an aromatic compound (B) in an amount of 35% by mass to 60% by mass relative to a total amount of the sizing agent except a solvent;
obtaining continuous strands by impregnating a melted matrix resin into the continuous sizing agent-coated carbon fibers obtained in said coating; and
cooling the strands obtained in said obtaining continuous strands and then cutting the cooled strands to obtain the cylindrical molding material (H).

### Claim 13 (depends on 12)

The method for manufacturing the molding material according to claim 12, further comprising:
impregnating a melted impregnation promoter (D) into the continuous sizing agent-coated carbon fibers before said obtaining continuous strands.

### Claim 14 (depends on 10)

A method for manufacturing the molding material (J1) according to claim 10, comprising
at least:
processing carbon fibers to a web-like cloth, a nonwoven cloth-like cloth, a felt-like cloth, or a mat-like cloth;
applying a sizing agent comprising at least an aliphatic epoxy compound (A) in an amount of 35% by mass to 65% by mass and an aromatic compound (B) in an amount of 35% by mass to 60% by mass relative to a total amount of the sizing agent except a solvent to the cloth obtained in the processing in an amount of 0.1 parts by mass to 10 parts by mass relative to 100 parts by mass of the cloth obtained in the processing; and
applying a matrix resin in an amount of 20% by mass to 99% by mass to 1% by mass to 80% by mass of the cloth to which the sizing agent is applied in the applying to form a composite product.

### Claim 15 (depends on 10)

A method for manufacturing the molding material (J2) according to claim 10, comprising:
at least:
coating carbon fibers with a sizing agent comprising at least an aliphatic epoxy compound (A) in an amount of 35% by mass to 65% by mass and an aromatic compound (B) in an amount of 35% by mass to 60% by mass relative to a total amount of the sizing agent except a solvent in an amount of 0.1 parts by mass to 10 parts by mass relative to 100 parts by mass of the carbon fibers;
cutting the sizing agent-coated carbon fibers obtained in said coating in a length of 1 mm to 50 mm; and mixing the sizing agent-coated carbon fibers cut in said cutting in an amount of 1% by mass to 80% by mass and the matrix resin in an amount of 20% by mass to 99% by mass to form a composite product.

### Claim 16 (depends on 10)

A method for manufacturing the molding material (K) according to claim 10, comprising:
at least:
firstly coating continuous carbon fibers with a sizing agent comprising at least an aliphatic epoxy compound (A) in an amount of 35% by mass to 65% by mass and an aromatic compound (B) in an amount of 35% by mass to 60% by mass relative to a total amount of the sizing agent except a solvent; and
secondly passing continuous sizing agent-coated carbon fibers obtained in the firstly coating through a melted matrix resin to further increase the width of the sizing agent-coated carbon fibers to obtain a prepreg having a width of 1 mm to 50 mm.

### Claim 17 (depends on 1)

A carbon fiber-reinforced resin molded article formed by molding the carbon fiber-reinforced resin composition according to claim 1.

### Claim 18 (depends on 1)

The carbon fiber-reinforced resin composition according to claim 1, wherein the sizing agent contains an ester compound (C) having no epoxy group in a molecule in an amount of 2% by mass to 35% by mass relative to a total amount of the sizing agent except a solvent.