Article made of propylene-ethylene copolymer
AssigneeMitsui Toatsu Chemicals, Inc.
InventorsYasunori Sugita, Yasuhiko Itagaki
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Abstract
Articles such as containers made of a highly crystalline olefin polymer having improved transparency and impact strength are obtained by biaxially extending an extruded tubular body of said polymer at an orientation temperature below the melting point thereof to attain an extension magnification ratio of at least 1.5 for each of the longitudinal and lateral directions. The polymer is a statistical random copolymer of propylene and from 1.5% to 5.0%, and preferably from 3.0% to 5.0%, by weight ethylene having a melt index of 0.6 - 3.0 g/10 min. Optionally, from 0.03 to 0.20 part by weight of p-tert. butyl benzoic acid, benzoic acid or sodium benzoate are added to 100 parts by weight of said copolymer.
Claims6
An article having improved transparency, impact strength and moldability which is obtained by cooling and solidifying an extruded tubular body of a highly crystalline olefin polymer and thereafter extending it biaxially by orientation blow molding at an orientation temperature below the melting point to attain an extension magnification ratio of at least 1.5 for each of longitudinal and lateral directions, wherein said polymer is a statistical random copolymer of propylene with ethylene which has a melt index of from 0.6 to 3.0 g/10 min. and an ethylene content of from 1.5% to 5.0% by weight.
Dependencies are inferred from the claim text.