| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a polyorganosiloxane which is excellent in transparency and light resistance and usable for application where it is required to develop stable and reproducible thermal shock resistance in thermal cycles.SOLUTION: The method for producing a polyorganosiloxane includes hydrolyzing in the presence of water a reactive organosilicon compound having a hydrolyzable group represented by the general formula (1): RXSiOand polycondensing the resulting hydrolysis product, wherein the number of foreign substances having a particle size of 30-100 μm contained in the water used for hydrolysis is 0-100/ml as measured at 25°C. In the formula, Rrepresents a hydrogen atom, a hydroxyl group or a monovalent organic group comprising one or more structures selected from the group of unsubstituted or substituted chain, branched and cyclic structures; X represents a monovalent hydrolyzable group; and m and n are each a number satisfying m≥0, n>0 and m+m=2-4. |
