Paper-like butene-1 polymer compositions

Abstract

A paper like butene-1 polymer sheet material is made by extruding a composition comprising (a) about 20 to 97% by weight of a butene-1 polymer having a molecular weight in excess of about 20,000, an isotacticity of at least about 25% and a butene-1 content of at least about 50% by weight, and (b) about 3 to 80% by weight of at least one normally solid filler insoluble in said polymer, to form a sheet, and stretching said sheet at least about 5% beyond its yield strain. The filler may be organic or inorganic and the sheet is preferably stretched at least about 20% beyond its yield point. The sheet is characterized by a novel surface appearance when scanned in an electron microscope, by dimensional stability and by approximately equal strengths in all directions as evidenced by a maximum tensile strength ratio of about 13:1 in mutually perpendicular directions.

Dependencies are inferred from the claim text.