The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 28, 2006
Filed:
Apr. 23, 2002
Makoto Komatsu, Ibaraki, JP;
Masato Inari, Okayama, JP;
Makoto Komatsu, Ibaraki, JP;
Masato Inari, Okayama, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
Crude polycarboxylic acid is slurried in an aqueous medium and the slurry is brought into contact with a metal catalyst while preventing catalyst components thereof from contaminating crystals. Since hydrogenation or decarbonylation of a polymerization inhibitory substance or a substance causing coloration can efficiently proceed at a low temperature while suppressing side reactions, a product having such a quality as to permit direct use thereof as such for polymerization can be obtained with good productivity. Also, since the contact temperature can be lowered, simplification of apparatus and energy saving may be attained.