High starch light weight gypsum wallboard
CA 2816891 C · Owner: United States Gypsum Company · Inventors: Song, Weixin D.; Lynn, Michael R.; Yu, Qiang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention generally provides gypsum-containing slurries including stucco naphthalenesulfonate dispersant, and pregelatinized starch. The naphthalenesulfonate dispersant is present in an amount of about 0.1% - 3.0% by weight based on the weight of dry stucco. The pregelatinized starch is present in an amount of at least about 0.5% by weight up to about 10% by weight of pregelatinized starch by weight based on the weight of dry stucco in the formulation. Other slurry additives can include trimetaphosphate salts accelerators, binders, paper fiber, glass fiber and other known ingredients. The invention also comprises the gypsum-containing products made with such slurries for example, gypsum …
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 8, 2006 and granted January 17, 2017. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 8, 2026.
- Certificates of supplementary protection extend only drug patents, and it isn't classified as one.
- 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.