GB548912A - Improvements relating to the production of aroxy silicones - Google Patents

Abstract

548,912. Resinous organo-silicon compounds. BRITISH THOMSON-HOUSTON CO., Ltd. April 24, 1941, No. 5295. Convention date, April 27, 1940. [Class 2 (iii)] Resinous aroxy silicones are obtained by hydrolysing an aroxy silicon dihalide of the formula (A-O-A<SP>1</SP>) 2 Si 2 , where A is a non- halogenated aryl radical, A<SP>1</SP> is an alkyl or non- halogenated aryl radical and X is a halogen atom, and dehydrating the hydrolysed product. Silicones containing less than two aroxy radicals per silicon atom may be similarly obtained from a mixture of different aroxy silican halides which may be separately hydrolysed before dehydration. Initial products are viscous liquids, soluble in organic solvents, which are further dehydrated by heating to form solid resinous masses. These products may be applied as coating compositions or compounded with other materials, as described in Specification 544,143. Solid products having less than two aroxy radicals for silicon atom may also be obtained by admixing and grinding individual silicones. In an example a mixture of di- and mono-phenoxyphenyl silicon chlorides, obtained by reacting phenoxyphenyl magnesium bromide with silicon tetrachloride, in ether solution, was hydrolysed by pouring the cold solution on to cracked ice and, after washing with water, the product was partly condensed by distilling off ether and heating to 110‹C. for 4 hours to yield the viscous liquid product; by further heating to 150-225‹C. for 1 hour, this was converted to a brown, hard resin.