SIZING AGENT FOR REINFORCEMENT FIBERS, SYNTHETIC FIBER STRANDS AND FIBER-REINFORCED COMPOSITE MATERIAL

摘要

Disclosed is a sizing agent for reinforcement fibers capable of giving superior adhesion to reinforcement fibers used for strengthening a thermoplastic matrix resin; also disclosed are synthetic fiber strands using said sizing agent, and a fiber-reinforced composite material. The disclosed sizing agent for reinforcement fibers is used for strengthening a thermoplastic matrix resin which necessarily contains a neutralized product of a modified polypropylene resin and an amine compound having two or more hydroxyl groups in the molecular structure or two or more amino groups in the molecular structure. Also, the amount of heat absorbed upon melting is 50J/g or less when the nonvolatile portion of the sizing agent is measured with a differential scanning calorimeter (DSC).