Process for preparing terephthalic acid
CA 1134856 A · Owner: Mitsubishi Chemical Industries Limited · Inventors: Harada, Sigeki; Hashizume, Hiroshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
TITLE OF THE INVENTION:, PROCESS FOR PREPARING TEREPHTHALIC ACID ABSTRACT OF DISCLOSURE, Preparation of terephthalic acid by oxidizing p-xylene with molecular oxygen in an acetic acid solvent in the presence of a catalyst containing at least one heavy metal and bromine. Preparation of terephthalic acid of high purity accompanied by low level of combustion of the acetic acid solvent can be achieved by, (i) introducing p-xylene and molecular oxygen into a first reaction zone kept at a temperature of 180 - 230°C to oxidize at least 95% by weight of the p-xylene into terephthalic acid;, (ii) introducing the reaction mixture obtained from the first reaction zone into a second reaction zone kept …
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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 November 2, 1982. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 2, 1999.
- 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
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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.