Melamine formaldehyde microencapsulation in aqueous solutions containing high concentrations of organic solvent
CA 2050544 C · Owner: Standard Register Company (The) · Inventors: Seitz, Michael E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for making melamine-formaldehyde microcapsules in an aqueous solution containing a high concentration of a water miscible or water soluble organic solvent is provided. The aqueous solution is prepared and a water insoluble melamine-formaldehyde pre-condensate is dissolved therein by adjusting the temperature and organic solvent concentration of the aqueous solution such that the melamine-formaldehyde pre-condensate is barely soluble therein. A substance to be encapsulated preferably an, oily solution containing a dyestuff precursor is, dispersed into the aqueous solution to form an emulsion the melamine-formaldehyde pre-condensate being insoluble in the substance to be …
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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 September 3, 1991 and granted February 15, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 3, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 3, 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
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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.