Cement composition
CA 2117585 C · Owner: Kesling, Haven S. Jr. · Inventors: Shawl, Edward T.; Kesling, Haven S. Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a cement composition containing a shrinkage reducing amount of a synergistic additive combination of a component having the formula:, R1O(AO)nH wherein A is a C2-C4 alkylene group or a combination of C2-C4 alkylene groups, n is 1-10, and R1 is a C1-C10 alkyl or cycloalkyl group with an alcohol having the formula ROH where R is a C4-C10 alkyl or cycloalkyl group and/or a dihydroxy compound having the formula HO(AO)nH where A is as above and n is 1-8.
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 August 29, 1994 and granted June 5, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 29, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 29, 2016.
- 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.