High surface gloss, co-extruded sheets from propylene polymer materials

摘要

A co-extruded sheet made from olefin polymer materials includes (1) at least one outer layer of (a) a propylene polymer having a melt flow rate of 0.5-15 dg/min, or a graft copolymer comprising a backbone of a propylene polymer material to which is graft polymerized a vinyl monomer, and (b) a nucleating agent having a melting point greater than 265° C. and (2) another layer made from (a) about 5% to about 50% of a high melt strength propylene homopolymer or copolymer, (b) optionally about 5% to about 40% of an inorganic filler, (c) about 2% to about 50% of an olefin polymer composition, and (d) optionally about 5% to about 70% of one or more other olefin polymer materials. The sheet has high surface gloss and good chemical resistance, and can be thermoformed using a melt phase thermoforming process wherein the surface temperature of the nucleated propylene polymer layer is from at least 310° F.