Process for preparing methylolhydantoins
CA 2096675 C · Owner: Lonza Inc. · Inventors: Burg, Douglas A.; Farina, Thomas E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There are provided methods for producing solid anhydrous methylolhydantoins. Initially, an aqueous stirrable medium is dehydrated and heated to yield a substantially anhydrous stirrable melt. The aqueous stirrable medium includes (A) a solute selected from the group consisting of (i) a dimethyloldimethylhydantoin, (ii) a hydantoin reactant (iii) a, formaldehyde source reactant, or (iv) a combination of any of the foregoing; and (B) optionally a catalyst. A molten system is then provided by adding, to the stirrable melt a reactant, mixture which includes (A)(i) the same or a different hydantoin reactant, (ii) a substantially anhydrous formaldehyde source reactant which may be the same as or …
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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 May 20, 1993 and granted February 18, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 20, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 20, 2015.
- 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.