Temporary wet strength paper
CA 2250177 A1 · Owner: Smith, David Jay · Inventors: Smith, David Jay; Headlam, Michael Martyn
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to paper products having temporary wet strength. The paper products contain cellulosic fibers that are treated with a polyaldehyde polymer having free aldehyde groups and a water soluble polyhydroxy polymer. The initial wet strength obtained with the combined use of these materials is significantly greater than that obtained by use of either the polyaldehyde or polyhydroxy polymer alone. At the same time the , wet strength decays at a rate that is rapid enough to enable the paper product to be flushed under conditions of normal use. Preferred polyaldehydes include cationic, aldehyde functionalized starches and cationic aldehyde , functionalized …
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 25, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 25, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 25, 2019.
- 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.