摘要 |
Preparation of a halogenoalkyldialkylchlorosilane by a hydrosilylation reaction followed by recovery of the platinum-based catalyst for re-use by contact with a solid adsorbent. The halogenoalkyldialkylchlorosilane of formula (I) :- Hal-(R2R3)Si-(CH2)s-Hal ; is prepared by a hydrosilylation reaction comprising a silane (II) : Hal-(R2R3)Si-H and an alkene halide (III) ; CH=CH-(CH2)S-2Hal ; in the presence of a catalytically effective amount of a Pt-based catalyst ; in which Hal = halogen(Cl, Br or I); R1, R2 = 1 - 6C hydrocarbyl or phenyl; s = 2 - 10. When the process is completed, the product (I) and the catalyst metal are recovered , the metal being in the original state or transformed of the metal is carried out by the stages :- a) Recovery directly on the reaction medium after completion of reaction or on the residue of distillation which comprises the by-products and the Pt-based metal or derivative ; b) Recovery of the metal by contact of the reaction medium or residue with a quantity of a solid adsorbent of the metal ; and c) Separation of the adsorbent from the metal for recovery of the metal.
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