Ammeline-melamine-formaldehyde resins (amfr) and method of preparation
CA 2104615 C · Owner: Ji, Shen · Inventors: Crews, George M.; Pittman, Charles U. Jr.; Ji, Shen
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Ammeline-melamine-formaldehyde resins (AMFR) containing from 5-10% ammeline were synthesized by the polymerization of the sodium salt of ammeline, which must be made in advance melamine and formaldehyde in basic medium (pH = 9.2 - 10.0). In this copolymerization, it is possible to make uniform random AMFR resins with any mole ratio of ammeline salt to melamine. Preferably the AMFR resin will contain from 5 - 10% ammeline. As an "ionomer" or a "polyelectrolyte" both the solid and, solution properties of these resins (such as melting temperature, solubility, solution stability etc.) depended, directly on the mole ratio of ammeline to melamine and formaldehyde and/or on the pH value of the …
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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
- Filed August 23, 1993 and granted September 17, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 23, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 23, 2015.
- 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.