Carbon fiber bundle for resin reinforcement, and method for manufacturing carbon fiber bundle for resin reinforcement, carbon-fiber-reinforced thermoplastic resin composition, and molded body

1. A carbon-fiber bundle for resin reinforcement, comprising a carbon-fiber bundle, an organic polymer substance (A) and an organic compound (B), wherein:

the carbon-fiber bundle is formed with a plurality of converged filaments;

a mixture, containing the organic polymer substance (A) with a weight-average molecular weight of 10000 or greater and the organic compound (B) with a thermal loss rate of 5 mass % or greater determined under the measurement condition below, is adhered to the carbon-fiber bundle at 0.1-5.0 mass % of the total mass of the carbon-fiber bundle for resin reinforcement; and the adhered amount of the organic polymer substance (A) is 0.1-0.5 mass % or greater of the total mass of the carbon-fiber bundle for resin reinforcement:

<Condition for Measuring Rate of Thermal Loss>

in a cylindrical container, which has a bottom diameter of 50 mm, and a height of 10 mm, W 0 (g) of a test sample is weighed and heated at 200° C. for 10 minutes in an air flow of 50 L, volume at 25° C. under 1 atmospheric pressure, per minute; and after the thermal treatment, the solid content is weighed and set as W 1 (g), and the rate of thermal loss is calculated by the following formula:

(thermal loss rate (mass %))=[( W 0 − W 1 )/ W 0 ]×100.

2. A carbon-fiber bundle for resin reinforcement, comprising a carbon-fiber bundle, an organic polymer substance (A) and an organic compound (B),

wherein:

the carbon-fiber bundle is formed with a plurality of converged filaments;

a mixture, containing the organic polymer substance (A) with a weight-average molecular weight of 10000 or greater and the organic compound (B) with a thermal loss rate of 0.8 mass % or greater when determined under the measurement condition below, is adhered to the carbon-fiber bundle at 0.1-5.0 mass % of the total mass of the carbon-fiber bundle for resin reinforcement; and

the adhered amount of the organic polymer substance (A) is 0.1-0.5 mass % of the total mass of the carbon-fiber bundle for resin reinforcement:

<Condition for Measuring Rate of Thermal Loss>

under air atmosphere, W 0 (g) of a test sample is heated at 20° C./min. and a thermal loss curve is prepared;

then, when the mass measured at 150° C. is set as W 1 (g) and the mass measured at 200° C. is set as W 2 (g), the rate of thermal loss is calculated by the following formula:

(thermal loss rate(mass %))=[( W 0 −W 2 )/ W 0 ]×100−[( W 0 −W 1 )/ W 0 ]×100.

3. The carbon-fiber bundle for resin reinforcement according to claim 1 , wherein the amount of organic compound (B) adhered onto the carbon fiber is 0.2-4.0 mass % of the total mass of the carbon-fiber bundle for resin reinforcement.

4. The carbon-fiber bundle for resin reinforcement according to claim 1 , wherein mass of the organic polymer substance (A): mass of the organic compound (B) in the mixture is set to have a mass ratio of 8.5:1.5-2:8.

5. The carbon-fiber bundle for resin reinforcement according to claim 1 , wherein the main chain of the organic polymer substance (A) is structured with carbon-carbon single bonds.

6. The carbon-fiber bundle for resin reinforcement according to claim 1 , wherein the organic polymer substance (A) is at least one selected from the group consisting of modified polyolefins containing an acid group on its side chain, and (meth)acrylic copolymers.

7. The carbon-fiber bundle for resin reinforcement according to claim 1 , wherein the organic polymer substance (A) is water soluble and/or self emulsifying.

8. The carbon-fiber bundle for resin reinforcement according to claim 1 , wherein the viscosity of the organic compound (B) at 30° C. is set at 2500 Pa·s or lower.

9. The carbon-fiber bundle for resin reinforcement according to claim 1 , wherein the organic compound (B) is a polyether-based surfactant.

10. The carbon-fiber bundle for resin reinforcement according to claim 1 , wherein the organic compound (B) is a lower alcohol ester of lower fatty acid.

11. The carbon-fiber bundle for resin reinforcement according to claim 1 , wherein the organic compound (B) is a urethane resin.

12. A method for manufacturing the carbon-fiber bundle for resin reinforcement according to claim 1 , comprising:

a step for bringing the carbon-fiber bundle into contact with an aqueous dispersion or solution containing the organic polymer substance (A), the organic compound (B) and a solvent; and

a step for removing the solvent by applying heat in a range of 110° C.-180° C.

13. A method for manufacturing a carbon-fiber-reinforced thermoplastic resin composition, comprising:

a step for opening a carbon-fiber bundle for resin reinforcement;

and a step for impregnating the carbon-fiber bundle by bringing it into contact with a thermoplastic resin (C) heated at 180° C. or higher, wherein:

the carbon-fiber bundle for resin reinforcement comprises a carbon-fiber bundle, an organic polymer substance (A) and an organic compound (B);

the carbon-fiber bundle is formed with a plurality of converged filaments;

a mixture, containing the organic polymer substance (A) with a weight-average molecular weight of 10000 or greater and the organic compound (B) with a thermal loss rate of 5 mass % or greater determined under the measurement condition below, is adhered to the carbon-fiber bundle at 0.1-5.0 mass % of the total mass of the carbon-fiber bundle for resin reinforcement; and the adhered amount of the organic polymer substance (A) is 0.1-0.5 mass % of the total mass of the carbon-fiber bundle for resin reinforcement:

<Condition for Measuring Rate of Thermal Loss>

in a cylindrical container, which has a bottom diameter of 50 mm, and a height of 10 mm, W 0 (g) of a test sample is weighed and heated at 200° C. for 10 minutes in an air flow of 50 L, volume at 25° C. under 1 atmospheric pressure, per minute; and after the thermal treatment, the solid content is weighed and set as W 1 (g), and the rate of thermal loss is calculated by the following formula:

(thermal loss rate (mass %))=[( W 0 −W 1 )/ W 0 ]×100.

14. The method for manufacturing a carbon-fiber-reinforced thermoplastic resin composition according to claim 13 , wherein the thermoplastic resin (C) is at least one resin selected from the group consisting of polyolefins and polyamides.

15. A method for manufacturing a carbon-fiber-reinforced thermoplastic resin molded body, comprising:

a step for heating at 200° C. or higher the a carbon-fiber-reinforced thermoplastic resin composition obtained by a manufacturing method, wherein:

the manufacturing method comprises:

a step for opening a carbon-fiber bundle for resin reinforcement; and

a step for impregnating the carbon-fiber bundle by bringing it into contact with a thermoplastic resin (C) heated at 180° C. or higher, the carbon-fiber bundle for resin reinforcement comprises a carbon-fiber bundle, an organic polymer substance (A), and an organic compound (B), the carbon-fiber bundle is formed with a plurality of converged filaments;

a mixture, containing the organic polymer substance (A) with a weight-average molecular weight of 10000 or greater and the organic compound (B) with a thermal loss rate of 5 mass % or greater determined under the measurement condition below, is adhered to the carbon-fiber bundle at 0.1-5.0 mass % of the total mass of the carbon-fiber bundle for resin reinforcement; and the adhered amount of the organic polymer substance (A) is 0.1-0.5 mass % of the total mass of the carbon-fiber bundle for resin reinforcement:

<Condition for Measuring Rate of Thermal Loss>

in a cylindrical container, which has a bottom diameter of 50 mm, and a height of 10 mm, W 0 (g) of a test sample is weighed and heated at 200° C. for 10 minutes in an air flow of 50 L, volume at 25° C. under 1 atmospheric pressure, per minute; and after the thermal treatment, the solid content is weighed and set as W 1 (g), and the rate of thermal loss is calculated by the following formula:

(thermal loss rate (mass %))=[( W 0 −W 1 )/ W 0 ]×100.