Structures for controlled chemical release
CA 1280073 C · Owner: Qinetiq Limited · Inventors: Benjamin, John David; Mears, Adrian Leonard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of fabricating a structure for the controlled release of a substance located in the structure between two relatively insoluble layers in which a first relatively insoluble layer (9) a, soluble layer containing the substance to be released (12a,b) and a second relatively insoluble layer (15) are deposited sequentially on a substrate (8), followed by the removal of the substrate the shapes, of the layers being such that the soluble layer is entirely surrounded by the relatively insoluble layers except for one or more release orifices. The shape of the soluble layer may be designed to provide a pulsed release of the substance or may comprise a plurality of different substances to be …
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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
- Granted February 12, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 12, 2008.
- 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.