Thermoplastic PVC molding compositions

摘要

Blends of (a) a vinyl chloride polymer having a relative viscosity as measured at a concentration of 1 gram per 100 grams of cyclohexanone at 25 DEG C. falling within the range of about 1.50 to about 1.85; (b) a copolymer of a vinyl aromatic compound and an alpha , beta -unsaturated cyclic anhydride in which the relative proportions of said compound and said anhydride fall within the range of about 91 to about 70 weight percent of said compound and about 9 to about 30 weight percent of said anhydride; and (c) a tin-containing stabilizer and an impact modifier for vinyl chloride polymers. These blends contain 60 to 40 weight percent of (a) and 40 to 60 weight percent of (b) and have an Izod impact strength (ASTM D 256, Method A) of at least 0.5 foot pound per inch; a heat deflection temperature (ASTM D 648) at 66 psi of at least 75 DEG C.; and a dynamic thermal stability of at least 10 minutes.