Preparation method of methyl tin mercaptide

Abstract

The invention belongs to the technical field of preparation of methyl tin mercaptide, and particularly relates to a preparation method of methyl tin mercaptide, which comprises the following steps: S1, planing tin bricks with better quality into tin sheets, and putting the tin sheets into a reactor; s2, metal tin and a first catalyst are put into a reaction kettle, then chloromethane is introduced for halogenation, then a redistribution agent is added for a tinning reaction, distillation is performed, fractions with the gas temperature ranging from 150 DEG C to 230 DEG C are received, and then pure water is used for absorption to obtain a methyl tin chloride aqueous solution; the methyl vinyl chloride comprises dimethyl tin dichloride and methyl tin trichloride; and S3, adding the obtained methyl tin chloride aqueous solution into isooctyl thioglycolate, adding a second catalyst, carrying out a stirring reaction at a temperature of 5-15 DEG C for 0.2-0.4 h, adding an alkali liquor, carrying out a continuous stirring reaction until the pH value of the reaction system reaches 7-9, heating to 60-70 DEG C, carrying out a reaction for 1-1.5 h, standing, cooling, and layering.

Description

technical field [0001] The invention belongs to the technical field of tin methyl mercaptide preparation, and in particular relates to a preparation method of tin methyl mercaptide. Background technique [0002] Methyl tin mercaptide is one of the three major organotin varieties. It is a transparent, clear and viscous liquid with good compatibility with PVC. Compatible with polar oils, non-flammable, low freezing point, viscous liquid even at -20°C; [0003] The industrial product is mainly a mixture of dimethyl tin mercaptide and monomethyl tin mercaptide, the general product is the weight ratio of monomethyl tin mercaptide to dimethyl tin mercaptide is 20:80, and monomethyl tin mercaptide is Tin has excellent stability in the early stage, and dimethyl tin mercaptide shows better stability in the later stage. Methyltin mercaptide has been approved by the US FDA (21 CFR 178.2010) and certified by the German BGA (ⅡA, 4C). It can be used in food packaging materials and water...

AI Technical Summary

Problems solved by technology

The compatibility between methyl tin and PVC is better than that of butyl tin and octyl tin; better fluidity: methyl tin mercaptide can improve the melting effect of PVC, so that PVC has good fluidity during processing, and its plasticizing effect on resin Compared with mixed metal or lead salt stabilizers, it produces lower melt viscosity, so methyl tin is the best heat stabilizer for hard PVC mixtures; strong scaling resistance: using methyl tin mercaptide does not Scaling will occur, which can reduce the number of equipment cleanings, improve production efficiency, reduce production costs, and expand profits, but the existing tin methyl mercaptide preparation is inconvenient