Synthesis method of hydroxyl silicone oil

Abstract

The invention provides a synthesis method of hydroxyl silicone oil. The method comprises the following steps: step one, adding hexamethylcyclotrisiloxane, an end-capping reagent, a solvent and a catalyst into a reaction kettle, performing heating until the solvent is boiled, and making a reaction for 1-5 hours at the boiling point of the solvent until the reaction is complete; step two, adding a neutralizer to neutralize until the pH value is 6-8, pumping out the solvent, the end-capping reagent and unreacted hexamethylcyclotrisiloxane under vacuum to obtain a crude product, and filtering outsalt in the crude product to obtain a hydroxyl silicone oil finished product; and step three, analyzing the proportion of each component of the solvent, the end-capping reagent and the unreacted hexamethylcyclotrisiloxane extracted in the step two by using a gas chromatograph, and adding the components into the next batch of reaction production for recycling. The synthesis method has the advantages of no use of controlled chemical raw materials, simple process, completion in one reaction kettle, no generation of waste water and waste gas in the process, generation of less than 10KG per ton ofsalt, cyclic use of the solvent in the reaction, very low process cost, environmental protection, simple process and easy control.

Description

technical field [0001] The invention belongs to the technical field of hydroxy silicone oil synthesis, and in particular relates to a synthesis method of hydroxy silicone oil. Background technique [0002] Low-viscosity hydroxyl-terminated silicone oil (viscosity 10-100cps) is widely used as a structure control agent for silicone rubber compounds and a hydrophobic treatment agent for inorganic materials. At present, there are two main methods for the synthesis of low-viscosity hydroxyl silicone oil: [0003] The first method: direct hydrolysis of dimethyldichlorosilane. The HCl released during hydrolysis of dimethyldichlorosilane monomer is neutralized with excess ammonia to form NH 3 -NH 4 Cl buffer solution. Dimethyldichlorosilane was added dropwise to ammonia water (containing NH 4 OH24% or so) to control the reaction temperature below 30°C, stir rapidly to allow the monomer and its dispersed phase to enter the reaction system, and the oil phase generated by the reac...

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Problems solved by technology

Therefore, this process is not environmentally friendly, th