Maleic anhydride graft copolymers having low yellowness index and films containing the same
CA 1339160 C · Owner: Lancaster, Gerald M. · Inventors: Lancaster, Gerald M.; Tabor, Ricky L.; Strait, Chad A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Maleic anhydride can be satisfactorily grafted to polymers at low pressures by feeding the polymer through a multiple screw extruder and injecting the maleic anhydride and a free radical initiator into a polymer filled, pressurized section of the extruder. The maleic anhydride and initiator can be pre-mixed in a solvent solution. The solvent and unreacted maleic anhydride can be removed by low pressure devolatilization. The graft copolymer has a yellowness index as measured by ASTM D-1925-70 less than about 10.0 and as measured by ASTM E-313-73 less than about 11Ø Further, between 0.75 and 2.0 weight percent of the graft copolymer comprises maleic anhydride. The graft copolymer can further …
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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 29, 1997. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 29, 2014.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.