Method for preparing aromatic carboxylic acids
Patent 5292934 Issued on March 8, 1994. Estimated Expiration Date: 
June 18, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
June 18, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3171856 3644507 3717674 3862218 Crystallization of water-insoluble dicarboxylic acid Patent #: 5149867 InventorsAssigneeApplicationNo. 900593 filed on 06/18/1992US Classes:562/413, Multistage562/421, Air, oxygen, or ozone oxidant562/487By reaction of undesired componentExaminersPrimary: Dees, Jose G.Assistant: Clarke, Vera C. Attorney, Agent or FirmForeign Patent References
International ClassesC07C 051/23C07C 051/265 C07C 051/487 AbstractDisclosed is a method for preparing an aromatic carboxylic acid comprising oxidizing in the liquid phase an aromatic feed compound containing at least one alkyl or acyl group with a molecular oxygen-containing gas, in a solvent comprising a low molecular weight aliphatic carboxylic acid, and in the presence of a heavy metal oxidation catalyst, thereby forming an oxidation reaction product mixture comprising an aromatic carboxylic acid; subsequently heating the oxidation reaction product mixture at a temperature of at least about 500° F. to form a second product mixture; and recovering from the second product mixture the aromatic carboxylic acid. The method of this invention provides for purer, larger particle size aromatic carboxylic acid product. |
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