Halogenated copolycarbonates having improved end group selectivity and resistance to degradation
CA 2035958 A1 · Owner: Marks, Maurice J. · Inventors: Marks, Maurice J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A halogenated copolycarbonate which contains, reduced levels of Phenolic (-OH) End Groups and end groups which result from side reactions of process chemicals with the copolycarbonate chain (Process Chemical End Groups), has improved resistance to the degradation-inducing effects of such end groups and has improved washability. Such a halogenated copolycarbonate is characterized in that it (a) has a Phenolic End Group content of less than 275 ppm (b) has, a content of less than 90 ppm of the element of Process Chemical End Groups which is bonded to a copolycarbonate chain end, and (c) produces less than 0.5 absorbance units, per mole fraction of halogenated diphenol in the copolycarbonate, …
Read the whole patent
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
- Filed February 7, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 7, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 7, 2013.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.