摘要:
A description if given of novel siloxane copolymers producible by (a) reacting in a first step organopolysiloxanes (1) which comprise per molecule at least one Si-bound hydrogen atom with substantially linear oligomeric or polymeric compounds (2) of the general formula R1-(A-CnH2n)m-A1-H (I), wherein R1 is a monovalent substituted or unsubstituted hydrocarbon moiety to which Si—H groups can be added in a hydrosilylation reaction, A is a divalent, polar organic moiety selected from the group —O—, —C(O)—O—, —O—C(O)—, —O—C(O)—O—, —C(O)—NH—, —NH—C(O)—, urethane moiety and urea moiety, A1 is a divalent, polar organic moiety selected from the group —O—, —NH— and —NR′— (wherein R′ is a monovalent hydrocarbon moiety having 1 to 18 carbon atoms), n is an integer from 1 to 20 and m is O or a positive integer, (b) reacting in a second step the resultant H-A1 group-bearing intermediates (4) with organic compounds (5) which comprise per molecule at least two isocyanate groups, wherein the reaction takes place in the presence of further organic compounds (6) and (7) which are reactive toward isocyanate groups, with the proviso that the compounds (6) contain at least one tertiary amine group and that the compounds (7) are those which can be eliminated again from the siloxane copolymer in a temperature range from 50° C. to 250° C., wherein free isocyanate groups are again formed in the siloxane copolymer, and (c) partially or completely quaternizing in a third step the amine-containing intermediates (8) from step (b) with an alkylating agent (9).
摘要:
The present invention relates to a method for preparing a polyorganosiloxane, that contains mono- and tetrafunctional units, by hydrolysis and condensation of mixtures of alkyl silicates and alkylsilanes and/or their hydrolyzates and compounds containing SiCl groups.
摘要:
A continuous method for producing polyorganosiloxanes by multiple-step hydrolysis and condensation of alkoxysilanes in the presence of hydrogen chloride and/or of a compound that has at least one SiCl group, and an organic solvent immiscible with water.
摘要:
Siloxane copolymers producible by (a) reacting organopolysiloxanes (1) having a Si-bound hydrogen atom with linear oligomeric or polymeric compounds (2) of the general formula R1-(A-CnH2n)m-A1-H (I), (b) reacting the resultant H-A1 group-bearing intermediates (4) with organic compounds (5) having at least two isocyanate groups in the presence of further organic compounds (6) and (7) which are reactive toward isocyanate groups, wherein the compounds (6) contain at least one tertiary amine group and the compounds (7) can be eliminated from the siloxane copolymer in a temperature range from 50° C. to 250° C., wherein free isocyanate groups are formed in the siloxane copolymer, and (c) partially or completely quaternizing the amine-containing intermediates (8) from step (b) with an alkylating agent (9).
摘要:
Silicone resin emulsions especially suitable for hydrophobing gypsum compositions together with H-siloxanes are prepared by hydrolysis and subsequent distillation to an alcohol content of less than 0.1 weight percent. Use of the emulsion with H-siloxanes provides plaster products such as plasterboard of increased hydrophobicity.