Application research and development of gaseous-phase silicon dioxide.

According to the information from Guangzhou GBS Sci-Tech Industrial Co., Ltd., the project of "the preparation and surface modification of nanometer gaseous-phase silicon dioxide and its application in liquid silicone rubber" submitted by the company together with Guangzhou Tianci New Material Sci-Tech Co., Ltd. and Zhongshan University has won the 2004 open tender for major equipment and technology innovation projects in Guangdong.

In the commercial application of gaseous-phase silicon dioxide, the project will mix gaseous-phase silicon dioxide after surface modification with silicone rubber to produce liquid silicone rubber products and form a 2 000 t/a production scale of high-performance nanometer composite materials composed of gaseous-phase silicon dioxide and silicone rubber. The development of organosilicon new chemical materials is R&D focus of the state. There is yet no commercial production of liquid silicone rubber in China and great quantities of the product used in power and IT sectors have to be imported from abroad. The project can provide liquid silicone rubber products such as electronic cladding silicone rubber, flexible mold silicone rubber and liquid injection-molding silicone rubber to the domestic market.

It is reported that in 2002 GBS constructed a 500 t/a nanometer gaseous-phase silicon dioxide unit using byproduct methyl trichlorosilane in the organosilicone monomer production as raw material. The unit passed technical appraisal in 2003 and the company became one of the few enterprises in the world that have mastered the core technology.

The major problem in the application of gaseous-phase silicon dioxide is its dispersion in media. The synthesis of modifiers with good dispersion and the development of new surface modification technologies are keys to the solution.

The tender project will take the existing technology as the basis, develop a continuous surface treatment process and form a production demonstration base with a capacity of 1 000 t/a hydrophilic and 500 t/a hydrophobic gaseous-phase silicon dioxide. The production base can fully use byproducts from the organosilicon monomer plant. Hydrogen chloride generated in the gaseous-phase silicon dioxide production can also be recycled to the organosilicon monomer plant to be used in the synthesis of raw material chloromethane. A benign cycle for the utilization of resources can therefore be formed.