Olefin polymer films
AssigneeHimont Incorporated
InventorJames Giacobbe
Life of this patent
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Abstract
Disclosed are films or sheets comprising a blend of 1) a heterophasic olefin polymer composition and 2) a copolymer of ethylene with a CH.sub.2 .dbd.CHR alpha-olefin, where R is a C.sub.1-8 straight or branched alkyl. Coextruded films or sheets and laminates wherein at least one layer is a film or sheet as described above, and films or sheets of blends of the olefin polymer composition and another olefin polymer are also disclosed.
Claims9
A film or sheet material comprising a blend of 1) from 95 to 60%, by weight of a heterophasic olefin polymer composition prepared by polymerization in at least two stages which is comprised of
- (a) from about 10 to 50 parts of a propylene homopolymer having an isotactic index greater than 80, or a copolymer selected from the group consisting of (i) propylene and ethylene, (ii) propylene, ethylene and a CH.sub.2 .dbd.CHR alpha-olefin, where R is a C2-8 straight or branched alkyl, and (iii) propylene and an alpha-olefin as defined in (ii), said copolymer containing over 80% propylene and having an isotactic index greater than 80;
- (b) from about 5 to 20 parts of a semi-crystalline, essentially linear copolymer fraction having a crystallinity of about 20 to 60% wherein the copolymer is selected from the group consisting of (i) ethylene and propylene containing over 55% ethylene, (ii) ethylene, propylene, and an alpha-olefin as defined in (a) (ii) containing from 1 to 10% of the alpha-olefin and over 55% of both ethylene and alpha-olefin, and (iii) ethylene and an alpha-olefin as defined in (a) (ii) containing over 55% of said alpha-olefin, which copolymer is insoluble in xylene at room or ambient temperature;
- and
- (c) from about 40 to 80 parts of a copolymer fraction wherein the copolymer is selected from the group consisting of (i) ethylene and propylene containing from 20% to less than 40% ethylene, (ii) ethylene, propylene, and an alpha-olefin as defined in (a) (ii) wherein the alpha-olefin is present in an amount of 1 to 10% and the amount of ethylene and alpha-olefin present is from 20% to less than 40%, and (iii) ethylene and an alpha-olefin as defined in (a) (ii) containing from 20% to less than 40% of said alpha-olefin, and optionally with 0.5 to 10% of a diene, said copolymer fraction being soluble in xylene at ambient temperature, and having an intrinsic viscosity of from 1.5 to 4.0 dl/g;
- with the total of the (b) and (c) fractions, based on the total olefin polymer composition, being from about 50% to 90%, and the weight ratio of (b)/(c) being less than 0.4;
- and
- 2) from 5 to 40%, by weight of a copolymer of ethylene with a CH.sub.2 .dbd.CHR alpha-olefin, where R is a C.sub.1-8 straight or branched alkyl, having a density of from 0.890 to 0.940 g/cm.sup.3.
Dependencies are inferred from the claim text.