| 摘要 |
Novel liquid organopolysiloxane resins of the average composition [R1Si(CH3)2O+E,fra 1/2+EE ]a [(CH3)3SiO+E,fra 1/2+EE ]b [R2O+E,fra 1/2+EE ]c [R1Si(CH3)O]d [(CH3)2SiO]e [SiO2], wherein R1 is a C2-C8-alkenyl group, R2 is an optionally substituted, linear or branched C1-C8-alkyl group or a mixture thereof, a+b+c+d+e is about 1 to 6, d+e is about 0 to 3, the resin has a viscosity of 0.1 to 1000 Pas at 25 DEG C., and the alkenyl or vinyl content of the resin is in the range of 0.4 to 4 mmol/g, and their preparation by reacting at least one of tetraalkoxysilane and its partial hydrolyzate with at least one organosiloxane and a strong acid as catalyst in the presence of water and optionally an organic solvent at a temperature of about >40 DEG C. They are formulated into novel low viscosity polydiorganosiloxane compositions.
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