| abstract |
(57) [Problem] To provide a carbon fiber chopped strand which is excellent in sizing property, and is sizing with a sizing agent in which a matrix resin is hardly thermally deteriorated during molding, and a resin composition using the same. . The sizing agent has an adhesion amount of 1 to 7% by weight, and the weight loss rate Y (%) when heated from 25 ° C. to T ° C. in air (heating rate 50 ° C./min) is as follows. A carbon fiber chopped strand characterized by being in the range shown by the formula, and having an equilibrium moisture content of 0.05 to 0.3% when left in an atmosphere at a temperature of 25 ° C. and a relative humidity of 65%. Y <0.00251 T 2 −1.1326T + 133.143 (1) Here, Y (%) = 100 × (weight loss rate of chopped strand / adhesion rate of sizing agent), T is 250 ° C. or more 3 Represents temperatures below 50 ° C. |