| 摘要 |
PURPOSE:To provide a silicone fluid composed of a specific diorganopolysiloxane and having excellent low-temperature fluidity. CONSTITUTION:The objective silicone fluid of formula I [R<1> is 1-8C alkyl, etc.; R<2> is group of formula II (Q is hydrocarbon group; l is 3-6); n<=50] can be produced by (1) polymerizing divinyl tetramethyl disiloxane and octamethyl cyclotetrasiloxane in the presence of a catalyst (e.g. potassium hydroxide) to obtain alpha,omega-vinyldimethyl polysiloxane (component A), (2) separately mixing e.g. hexamethyl cyclotrisiloxane with dichlorodimethyl silane, reacting the compounds with each other in the presence of a catalyst (e.g. hexamethyl phosphamide), and hydrolyzing and neutralizing the reaction product to obtain a cyclic diorganopolysiloxane (component B), (3) adding the component B dropwise to the component A at room temperature in the presence of platinum catalyst, (4) reacting preferably at 110 deg.C under agitation, and (5) removing the low-volatile component. |
