Continuous preparation of copolyamides from caprolactam and salts of diamines and dicarboxylic acids
CA 2013148 C · Owner: Basf Aktiengesellschaft · Inventors: Koch, Eckhard M.; Cordes, Claus; Reimann, Horst
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
13-, Copolyamides are prepared by, a continuous process in which (a) an aqueous solution of salts of equimolar amounts of diamines and dicarboxylic acids is passed under, superatmospheric presure and with simultaneous evaporation of water, through a tubular precondensation zone with formation of a vapor phase and a prepolymer at above the melting point of the prepolymer, (b) the vapor phase is separated from the prepolymer melt, (c) the vapor phase is separated in a column into steam and an aqueous diamine solution, and the aqueous solution containing diamines is recycled to the polymerization, (d) the prepolymer melt is mixed with molten caprolactam at polyamide-forming temperatures, 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
- Filed March 27, 1990 and granted June 6, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 27, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 27, 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.