Process for continuous production of elastic polyesters
CA 2033095 C · Owner: Yamamoto, Yoshiyuki · Inventors: Yamamoto, Shoji; Ishii, Hiromitsu; Yamamoto, Yoshiyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An elastic polyester is continuously prepared by continuously supplying an aromatic polyester and a lactone compound into an extruder which has (A) a cylinder having a shape of 3 L/D 70 (where L represents the length of the cylinder and D represents the inner diameter of the cylinder) and (B) at least one screw and wherein (C) the occupancy ratio of the space in the inner volume of the cylinder in the screw-attached state is not larger than 70%, and reacting the aromatic polyester with the lactone compound while performing melting, delivery and kneading in the extruder according, to this process, the reaction time can be shortened and, an elastic polyester can be easily prepared at a high …
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 May 17, 1990 and granted January 14, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 17, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 17, 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.