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Publication numberUST955009 I4
Publication typeGrant
Application numberUS 05/689,545
Publication dateFeb 1, 1977
Filing dateMay 24, 1976
Priority dateJun 11, 1975
Also published asCA1086887A, CA1086887A1, DE2626278A1
Publication number05689545, 689545, US T955009 I4, US T955009I4, US-I4-T955009, UST955009 I4, UST955009I4
InventorsRobert Clive Lansbury, Thomas Geoffrey Heggs
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Film-forming composition
US T955009 I4
There is disclosed a thermoplastic, film-forming composition comprising a blend of
A. a propylene-ethylene copolymer, the propylene content of the copolymer being from 95 to 99.75% by weight of the copolymer, and
B. a polymer of an alpha-olefin of 4 to 10 carbon atoms copolymerized with from 0 to 10% by weight of the copolymer of an alpha-olefin of 2 to 10 carbon atoms,
The alpha-olefin polymer constituting from 41 to 90% by weight of the composition.
The propylene-ethylene copolymer preferably contains from 2 to 4% by weight of ethylene, and preferably, in granular form, exhibits a Melt Flow Index of from 10 to 200 g/10 minutes, measured according to ASTM/D1238-65T (Condition N).
The alpha-olefin component of the blend is suitably a polymer, preferably a homo-polymer, of butene-1, and suitably has a Melt Flow Index, by the aforementioned test, of less than 50 g/10 minutes, preferably between 5 and 40 g/10 minutes.
To ensure the production of films having acceptable optical characteristics, the alpha-olefin component preferably comprises from 45 to 65% by weight of the composition. Additives, such as pigments, anti-static agents, and the like, conventionally employed in film production, may be included in the composition, if desired.
The composition is suitably employed for the production of self-supporting films, and is particularly useful as a heat-sealable surface layer of a coextruded, biaxially oriented, multiple-layer film having a substrate layer of a propylene homo- or co-polymer. Such films are heat-sealable at comparatively low temperatures to provide strong heat seals, and are particularly suitable for the packaging of foodstuffs, and the like.
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5073458 *May 31, 1990Dec 17, 1991Shell Oil CompanyPolypropylene-polybutylene laminated packaging film with improved tear strength
US5075157 *May 31, 1990Dec 24, 1991Shell Oil CompanyPolypropylene-polybutylene laminated packaging film with improved tear strength
U.S. Classification428/515, 264/211.12, 426/127, 428/520, 525/240, 264/DIG.570, 428/910
International ClassificationC08L23/18, C08L7/00, C08L101/00, B32B27/32, C08L23/16, B29C55/00, C08L23/14, B29C55/02, B29C49/00, C08L21/00, C08L23/00, C08L23/20
Cooperative ClassificationB32B27/32, C08L23/142, Y10T428/31928, C08L23/20, Y10T428/31909, C08L23/18, Y10S264/57, Y10S428/91
European ClassificationC08L23/14A, B32B27/32