Composition and process and use in reactor scale prevention
CA 1307262 C · Owner: Occidental Chemical Corporation · Inventors: Hong, Paul O.; Dewald, Raymond C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure A composition having the formula, wherein n has an average value of one to about five is disclosed, for use in reducing or eliminating the formation of reactor scale during the polymerization of vinyl chloride and comonomers. The composition is prepared by reacting phenothiazine with formaldehyde in the presence of a liquid diluent that is a solvent for the phenothiazine, but a non-solvent for the dimer of phenothiazine and formaldehyde. The process of the invention is preferably conducted in the presence of a strong acid catalyst. The formaldehyde is preferably added slowly to the reaction mixture over the course of the reaction. The product can be filtered and …
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
- Granted September 8, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 8, 2009.
- 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.