Verfahren zur Herstellung eines organisch-modifizierten, hitzehärtbaren Siloxanharzes und dieses so hergestellte Harz

摘要

The prepn. of an organically-modified, heat-curable silicone resin comprises (a) reacting a trialkoxysilane of the formula (I), a difunctional diorganosilicone cpd., and at leat one polyol in the presence of a catalytic amt. of an acidic cationic siloxane polymerisation. catalyst to form an alkoxy-functional prod.; (b) hydrolysing all the hydrolysable alkoxy gps. by adding a predetermined amt. of water; (c) inactivating the acidic cationic siloxane polymerisation. catalyst in the hydrolysed prod.; and (d) stripping water and alcohol from the prod.. R2(OR1)3Si (I) OR1 = 1-4C alkoxy; and R2 = aryl and alkyl. Also claimed are (i) a heat-curable, organically-modified silicone resin prepd. by the above process; (ii) the prepn. of a cured organically-modified silicone resin comprising curing the hydrolysed prod. from above after the stripping step; (iii) an article of mfr. comprising the above cured organically-modified silicone resin on a substrate; and (iv) a paint formulation comprising the above organically-modified, heat-curable silicone resin in combination with a pigment.