| 摘要 |
PRODUCTION OF POLYDIORGANOSILOXANE FLUIDS WITH LOW SILANOL CONTENT A continuous process for producing a triorganosilyl end-blocked polydiorganosiloxane fluid with reduced silanol content and reduced branching content is described. The process comprises (a) feeding to a series of two columns packed with an acid-treated clay a liquid siloxane feed mixture, containing as a major portion a polydiorganosiloxane monomer and as a minor portion a triorganosilyl end-blocking material; (b) contacting the liquid siloxane feed mixture with the acid-treated clay in the first and second packed columns, respectively, at a temperature in a range from about 100.degree. to 150.degree.C. at a pressure in a range from about 5 to 1520 mm Hg at a contact time of less than about 15 minutes; (c) separating water vapor from an intermediate mixture between the first and second packed columns; and (d) collecting a product mixture which contains a triorganosilyl end-blocked polydiorganosiloxane fluid with silanol content substantially reduced from the equilibrium mixture. |
