Process for the preparation of an organopolysiloxane resin

摘要

Production of organopolysiloxane resin, comprises the reaction of silanes with water in the presence of acid, at least partially distillation of alcohol, addition of base as well as water-insoluble organic solvent to form a homogeneous reaction mixture with removal of water, alcohol and optionally a portion of the water-insoluble solvent by distillation, addition of organopolysiloxanes, neutralization and removal of the water-insoluble organic solvent. A process for the production of organopolysiloxane resin (I), comprises in a first step reaction of a silane of formula (1) and/or its hydrolysate of formula (2), a silane of formula (3) and/or its partial hydrolysate as well as optionally an organosilicon compound of formula (4) and/or its partial hydrolysate and/or organopolysiloxanes of formula (5) with water in the presence of acid whereby the resulting alcohol is at least partially distilled off, reaction in a second step using the resulting homogeneous reaction mixture from the first step in the presence of a base as well as a sufficient amount of water-insoluble organic solvent to yield a homogeneous reaction mixture with removal of water, alcohol and optionally a portion of the water-insoluble solvent by distillation, neutralization of the resulting reaction mixture in a third step, optional removed of remaining water, alcohol and a portion of the water-insoluble organic solvent by distillation, addition, in a fourth step, of organopolysiloxanes and optionally further components, removal of the salt precipitated by neutralization and, in a fifth step removal of the water-insoluble organic solvent from the resulting homogeneous reaction mixture. R3SiOR1 (1) R3SiOSiR3 (2) Si(OR2)4 (3) R3aSi(OR4)4-a (4) (R52SiO)b (5) R, R3,R5 = monovalent organic group; R1, R2,R4 = alkyl; a = 1 or 2; b = 3-8 (4 or 5).