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:
Jul. 04, 1995
Filed:
Dec. 17, 1993
Yoshiaki Tateno, Shizuoka, JP;
Chihaya Sano, Shizuoka, JP;
Kotone Tanaka, Shizuoka, JP;
Mitsuo Magara, Shizuoka, JP;
Naoki Okamoto, Chiba, JP;
Kazuaki Kato, Saitama, JP;
Towa Chemical Industry Co., Ltd., Tokyo, JP;
Abstract
An economic hydrogenation process is provided which significantly suppresses palladium catalyzer activity loss, for obtaining very high purity 1,4-CHDA through a simple operation. The process includes bringing the solution containing the hydrogenation reaction product of interest into contact with steam. The resultant products may include resins having excellent weather resistance or physical properties or high purity medical drugs. The process for preparing 1,4-cyclohexandicarboxylic acid is characterized by two consecutive steps. The first step includes the hydrogenation of a solution containing terephthalic acid in the presence of a palladium catalyzer in an acid resistant vessel or in a vessel layered with acid resistant material for preparing 1,4-cyclohexandicarboxylic acid. The second step includes contacting the solution containing 1,4-cyclohexandicarboxylic acid obtained in the first step with the steam, and extracting impurities moved to the steam.