Curing of polysulphides
CA 2024015 A1 · Owner: Lowe, George B. · Inventors: Lowe, George B.; Lee, Timothy C. P.; Robinson, Raymond
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of manufacturing a polysulphide polymer in particular, for use as a sealant in the construction industry and the like. A liquid polysulphide prepolymer is partially cured with an oxidizing curing agent such as calcium peroxide by adding a controlled , amount of water. As the cure reaches the end of its induction stage, before the viscosity rises substantially the reaction is, stopped by dehydrating with a desiccant. This gives a stable liquid prepolymer which can later be cured without an induction period by exposure to moisture and optionally a further curative.
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 January 2, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 2, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 2, 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.