Progress in Innocuous Treatment Methods of High-Boiling Residues Formed in the Synthesis of Methylchlorosilanes

In the direct synthesis of methylchlorosilanes, a series of complex by-products are formed, which comprises 7~8 weight percent of high-boiling residues (HBR). The commercial value of HBR is low, consequently large inventories of residues have been built up by the silicone industry. This inventory poses a serious problem for it represents an expensive, relatively useless material. Furthermore continued accumulation of the residue poses a storage problem. Catalytic cleavage, which converts Si-Si bond contained compounds in HBR to methylchlorosilanes, is a promising innocuous treatment technology. However, industrial applications of traditional catalysts such as Lewis acid or organic amine have limitations. Recently, with the development of mesoporous materials, kinds of new catalysts have been applied to increase the conversion rate and the selectivity of dimethyldichlorosilane. Other compounds could not be treated by catalytic cleavage, are converted to variety of organosilicon products by multiple ways. In this paper progress in the innocuous treatment technology of HBR were reviewed. In addition a new method using HBR for plastic filler was introduced.