Composition for producing paper and process
CA 2187461 C · Owner: Nuckolls, Hugh E. · Inventors: Nuckolls, Hugh E.; Blackstone, Michael M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A novel composition for use in a process for cooking wood to form pulp and processes for using same are provided. The composition and variations thereof are useful in enhancing the uniformity of wood cooking and reducing the rejects in a pulping process for the production of pulp. The composition comprises esters of block copolymers having the general formula (see fig.I), wherein x, y, and z each have a value of at least one or esters of polyoxyalkene glycols.
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 October 8, 1996 and granted May 27, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 8, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 8, 2018.
- 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.