| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a polydiorganosiloxane containing a little cyclic polydiorganosiloxane of low degree of polymerization. SOLUTION: In this manufacturing method of polydiorganosiloxane gum containing not higher than 1,000 ppm polydiorganosiloxane of low degree or polymerization, a cyclotrisiloxane (A) represented by general formula (1): (R<SP>1</SP>R<SP>2</SP>SiO)<SB>3</SB>(wherein R<SP>1</SP>and R<SP>2</SP>are each a monovalent hydrocarbon group or a monovalent hydrocarbon group substituted with a halogen atom) is polymerized using a peralkylphosphazene base (C) as a catalyst in the presence or in the absence of a compound (B) represented by general formula (2): HO(R<SP>1</SP>R<SP>2</SP>SiO)<SB>m</SB>H [wherein R<SP>1</SP>and R<SP>2</SP>are the same as those of (A) and m is an integer of 0-500] as a molecular weight controller, and after the polymerization, the reaction product is brought into contact with an acidic material (D) to deactivate the polymerization catalyst. COPYRIGHT: (C)2003,JPO
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