Process for producing aliphatic diols

US6037504A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Gerhard Darsow · Krefeld, DE
• Wolfgang Dummer · Krefeld, DE
• Wilfried Niemeier · Krefeld, DE

Key dates

• Filing date: Dec 3, 1998
• Grant date: Mar 14, 2000
• Expiry date: Dec 3, 2018

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/52
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

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.