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:
Dec. 09, 1997
Filed:
Jan. 05, 1996
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
In a process for the preparation of aliphatic .alpha.,.omega.-diols of 4 to 12 carbon atoms from aliphatic .alpha.,.omega.-dicarboxylic acids of 4 to 12 carbon atoms, an oligo ester is first of all formed from diol and dicarboxylic acid and is subsequently subjected to catalytic hydrogenation in the liquid phase. The hydrogenation is carried out continuously at from 180.degree. to 250.degree. C. and at an H.sub.2 pressure of from 100 to 400 bar over a catalyst in piece form comprising compressed powders of Cu, Zn and Al oxides which do or do not contain at least one oxide of metals of the iron group of the Periodic Table of the Elements (Mendeleev) or of manganese. The quantity of H.sub.2 is from 20 to 100 times the stoichiometrically required quantity.