| 摘要 |
PROBLEM TO BE SOLVED: To obtain a foamable vinyl chloride resin compsn. for injection molding which can give a foam expanded twice or higher even with an ordinary injection molding machine by compounding a vinyl chloride resin with a specific polymethyl methacrylate resin and a thermally decomposable blowing agent. SOLUTION: This compsn. is prepd. by compounding 100 pts.wt. vinyl chloride resin having an average degree of polymn. of 400-1,000 with 2-30 pts.wt. polymethyl methacrylate resin having a wt. average mol.wt. of 4,500,000-7,000,000 and 0.5-10 pts.wt. thermally decomposable blowing agent. Since the latter resin disperses homogeneously in the former, the melt viscosity of the compsn. is maintained properly without causing excessive heat build-up, enabling a foam with uniform cells to be obtd. |
