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US 5,840,389 AGranted
Transparent impact-resistant molded articles
AssigneeMitsui Chemicals, Inc.
InventorsTadashi Asanuma, Tateyo Sasaki, Shosuke Nakanishi
Life of this patent
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Abstract
A molded article obtained by blow molding a propylene having a substantially syndiotactic structure or a resin composition comprising a polypropylene having a substantially syndiotactic structure and a copolymer of ethylene and propylene, and a multi-layer molded article obtained from this resin composition in which at least one surface of the molded article is a polypropylene layer having the substantially syndiotactic structure.
Claims11
A transparent and impact-resistant multi-layer blow-molded article which comprises:
- (i) at least one layer comprising a syndiotactic propylene homopolymer which has a syndiotactic pentad fraction of 0.7 or more and an intrinsic viscosity of from 0.5 to 10 measured in a tetrahydronapthalene solution at 135.degree. C. or a syndiotactic propylene copolymer which contains 10% by weight or less of ethylene or .alpha.-olefin units having 4 to 20 carbon atoms, and wherein a peak intensity observed at about 20.2 ppm in the absorption spectrum of .sup.13 C-NMR measured in a 1,2,4-trichlorobenzene solution of the polypropylene is 0.5 or more of a peak intensity attributed to all the methyl groups of the propylene unit and a copolymer of ethylene and propylene;
- and
- (ii) at least one surface layer comprising a syndiotactic propylene homopolymer which has a syndiotactic pentad fraction of 0.7 or more and an intrinsic viscosity of from 0.5 to 10 measured in a tetrahydronaphthalene solution at 135.degree. C.
Dependencies are inferred from the claim text.