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Expired Canadian patentCanada

Process for preparing polyimide and composite material thereof

CA 1316294 C · Owner: Tamai, Shoji · Inventors: Tamai, Shoji; Koba, Tomohito; Ohta, Masahiro

CIPO record

Overview

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Abstract From the Canadian patent

This invention relates to a method for preparing polyimide having good heat-stability and excellent flowability in a molten state. The polymide is prepared by reacting aromatic diamines such as 4,4'-bis(3-aminophenoxy)biphenyl, bis4-(3-aminophenoxy)phenyl ketone and bis 4-(3-aminophenoxy)phenyl sulfone; tetracarboxylic dianhydrides such as pyromellitic dianhydride 3,3',4,4'-benzophenonetetracarboxylic dianhydride and bis(3,4-dicarboxyphenyl) ether dianhydride; and monoamines such as n-hexylamine, cyclohexylamine, aniline 4-aminobenzophenone. The, molar ratio of tetracarboxylic dianhydride : aromatic diamine : monoamine is 1:(0.9 to 1.0):(0.001 to 1.0). Another aspect relates to polyimide …

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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 April 13, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 13, 2010.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledNovember 4, 1988
GrantedApril 13, 1993
Term endedApril 13, 2010
Patent numberCA 1316294 C
Classification (IPC)C08G73/10 +1 more

Timeline

Timeline From CIPO dates

19891992199519982001200420072010Application filedNov 4, 1988Patent grantedApril 13, 1993Term endedApril 13, 2010

Sources & verification

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