摘要 |
PURPOSE:To obtain an unsaturated polyester resin composition having small shrinkage during curing and excellent tinting, dimensional stability and surface characteristics, by blending an unsaturated polyester with polystyrene and styrene-diene block copolymer (hydrogenated substance or modified substance) in a specific ratio. CONSTITUTION:(A) 100 pts.wt. of an unsaturated polyester and a crosslinking agent (25-70 pts.wt. crosslinking agent) are blended with (B) polystyrene and (C) a styrene-diene block copolymer, an SBS-based or SIS-based thermoplastic elastomer using polystyrene as a hard segment and polybutadiene or polyisoprene as a soft segment, a hydrogenated substance or a modified substance thereof in an amount to give 15-50 pts.wt. components B+C and the weight ratio of the component B/C of (20/80)-(80/20) and mixed with a curing agent, a filler, a mold-release compound, a thickening agent, a fiber reinforcing material, pigment, etc., to give an unsaturated polyester resin composition. |