Copolymerized anthraquinone-polyester color concentrates
CA 2064802 C · Owner: Parham, William Whitfield · Inventors: Oldfield, Terry Ann; Parham, William Whitfield; Weaver, Max Allen
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed are color concentrate compositions which comprise a polyester having copolymerized therein at least 0.5 weight percent of an anthraquinone colorant compound having formula (I) wherein AQ is a 1,5- or 1,8-anthraquinonylene radical; R1 and R2 are the same or different and are unsubstituted or substituted alkyl cycloalkyl or aryl; and X is a group reactive with at least one of the functional groups of the monomers from which the polyester is prepared. Amorphous polyesters and partially-crystalline polyesters are preferred embodiments of the color concentrates. Also disclosed are colored semicrystalline powders which may be obtained from the amorphous and partially-crystalline color …
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 August 29, 1990 and granted January 28, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 29, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 29, 2012.
- 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.