Patent ID: 9175138
Filing Date: 2015-11-03
Classification: C08G

Abstract:
1. A method for producing organopolysiloxanes comprising per molecule at least one structural unit of formulae comprising: (a) in a first step, contacting a mixture of compounds of formulae and siloxanes which comprise per molecule at least one structural unit of the formulae and mixtures thereof and which have a molar mass (M w weight-average) of from 100 to 950 g/mol with a catalyst, wherein the catalyst is an activated carbon, and (b) in a second step the mixture obtained therefrom is reacted with water or an aqueous acid, to obtain organopolysiloxanes which comprise per molecule at least one structural unit of formulae (I) and (II), and having a molar mass (M where R are identical or different and represent a monovalent SiC-bonded organic radical which comprises from 1 to 30 carbon atoms and optionally contains one or more nitrogen and/or oxygen atoms, R Y are divalent to dodecavalent organic radicals which comprise from 1 to 30 carbon atoms and which optionally contain one or more oxygen atoms, X is a hydrolyzable group, a is 0 or 1, b is an integer of from 1 to 11 and c is 0, 1, 2 or 3, with the proviso that the siloxanes employed which comprise per molecule at least one structural unit of formulae (V) and (VI) and mixtures thereof are by-products which are formed in addition to the organopolysiloxanes comprising the structural units (I) and (II), have been removed from the organopolysiloxanes comprising the structural units (I) and (II), and recycled into the method.