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Expired Canadian patentCanada

Foam structure of coalesced foam strands or profiles

CA 1304899 C · Owner: The Dow Chemical Company · Inventors: Russell, Robert J.; Malone, Bruce A.; Yao, Peter C.

CIPO record

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Improved closed cell foams, particularly suitable for use in packaging applications, comprise a plurality of coalesced parallel strands or profiles of thermoplastic resin. When the resin is a non-aromatic olefin, the heat seal strength of a film thereof is at least 30 Newtons/inch (2.5 cm) width. Preferably the, resin is a mixture of an olefin polymer resin and a copolymer of ethylene with one or more copolymerizable comonomers having a lower melting point than the olefin polymer resin. The cross-section of the strands or profiles and/or their spacial arrangement advantageously are such that they are joined at their extremities to form a network defining voids. The resin may contain up to …

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Granted July 14, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 14, 2009.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledFebruary 19, 1988
GrantedJuly 14, 1992
Term endedJuly 14, 2009
Patent numberCA 1304899 C
Classification (IPC)B29C44/18 +2 more

Timeline

Timeline From CIPO dates

1989199219951998200120042007Application filedFeb 19, 1988Patent grantedJuly 14, 1992Term endedJuly 14, 2009

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.