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:
Mar. 14, 2000
Filed:
Dec. 03, 1998
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
In a process for producing aliphatic .alpha.,.omega.-diols comprising 4 to 12 C atoms from aliphatic .alpha.,.omega.-dicarboxylic acids comprising 4 to 12 C atoms, an oligoester of average chain length n=3 to n=4.5 and with an acid number of 40 to 60 mg KOH/g reaction mixture is first formed from a diol and a dicarboxylic acid, which oligoester is thereafter catalytically hydrogenated in the liquid phase. Hydrogenation is carried out continuously at 180 to 250.degree. C. and at an H.sub.2 pressure of 100 to 400 bar, over a pelletised catalyst which is free from Zn oxide and which comprises pressed powders of Cu, Mn and Al oxides with a content of at least one oxide of metals of subgroup VI of the periodic table of the elements (Mendeleev). The amount of H.sub.2 is 20 to 100 times the amount required stoichiometrically.