Continuous manufacturing process for organoalkoxysiloxanes

US6767982B2 · kind B2 · utility

Assignee

• Degussa AG · DE

Inventors

• Burkhard Standke · Soest, DE
• Michael Horn · Rheinfelden (Baden), DE

Key dates

• Filing date: Nov 14, 2001
• Grant date: Jul 27, 2004
• Expiry date: Dec 14, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09D183/04
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A mixture of organoalkoxysiloxanes of formula I: wherein R and R″ are identical or different and are methyl, ethyl, vinyl, n-propyl, i-propyl, &ggr;-chloropropyl, n-butyl, i-butyl, n-pentyl, i-pentyl, n-hexyl, i-hexyl, n-heptyl, i-heptyl, n-octyl, i-octyl, hexadecyl, octadecyl or alkoxy, R′ represents methyl or ethyl, n and m are identical or different and each is 0 or an integer ranging from 1 to 20, on the condition that (n+m)≧2, is prepared by:reacting in a first stage the constituents of (i) an organotrichlorosilane or a mixture of organotrichlorosilanes or a mixture of at least one organotrichlorosilane and tetrachlorosilane, (ii) water and (iii) alcohol, combined in a molar ratio (i):(ii):(iii) of 1:(0.59 to 0.95):(0.5 to 100), at a temperature of 0 to 150° C., which produces hydrogen chloride as a product which is removed from the system and the crude organoalkoxysiloxane product is transferred proportionately to the reaction distillation column of a subsequent second stage after an average dwell time of 0.5 to 180 minutes; andconducting reaction and distillation in the reaction distillation column in a second stage in which volatile constituents are withd…