Paper sizing composition
CA 2488926 A1 · Owner: Roberts, John · Inventors: Zetter, Claes; Peng, Guomei; Sundberg, Kenneth
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to the sizing of paper and board using alkenyl succinic anhydride (ASA). The invention provides a sizing composition which comprises an aqueous emulsion of an ASA wherein the ASA incorporates a maximum of 1% by weight (preferably a maximum of 0.5 % by weight) of polymeric residues.The composition may incorporate less than 0.5 % by weight of olefins. Paper sizing compositions in accordance with the invention provide enhanced resistance to penetration of the edges of paper and board by agents such as hot hydrogen peroxide and lactic acid.
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 June 12, 2003. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 12, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 12, 2025.
- 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.