Cyclolinear polyorganosiloxanes and method for preparing same

Abstract

Cyclolinear polyorganosiloxanes are proposed having the formula [XC.sub.6 H.sub.4 SiO.sub.1.5 ].sub.n Where X is F, Cl or Br and n is from 2 .times. 10 to 2 .times. 10.sup.4 and the method for preparing them, that consists in hydrolytic polycondensation of the starting phenyltrichlorosilane halide in an organic solvent immiscible with water at temperatures from 5.degree. to 40.degree.C; water is then separated and the solution of the reaction products in the organic solvent is washed with water to neutral reaction and polymerized in the presence of a nucleophilic catalyst utilized in an amount of from 0.002 to 0.25 per cent by weight, at temperatures from 80.degree. to 250.degree.C, with subsequent isolation of the end product. X may be in ortho, metal or para position, or mixed isomers may be used.

Dependencies are inferred from the claim text.