Method for preparing p-isobutylstyrene
CA 2002243 C · Owner: Uchida, Kazumichi · Inventors: Tokumoto, Yuichi; Matsumura, Yasuo; Uchida, Kazumichi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for preparing a high-purity p-isobutylstyrene is here disclosed which comprises the first step of reacting o- and/or m-isobutylethylbenzene, if necessary together, with isobutylbenzene, in the presence of an acid catalyst in a liquid phase at a reaction temperature of -10 to 600°C so that the production of sec-butylethylbenzene in butylethyl-benzene may not exceed 20% by weight, in order to form a mixture of p-isobutylethylbenzene and sec-butylethylbenzene; and the second step of bringing the mixture of p-isobutyl-ethylbenzene and sec-butylethylbenzene recovered from the first step into contact with a dehydrogenation metal catalyst containing at least one metal selected from the …
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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 November 6, 1989 and granted December 30, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 6, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 6, 2011.
- 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.