GB860522A - Improvements in or relating to silicone compositions - Google Patents

Abstract

Waterproofing compositions consist essentially of (1) from 65 to 85% (by weight) of a methylsiloxane composed of 65 to 80 mol. per cent of CH3.SiO 3/2 , 15 to 30 mol. per cent of (CH3)2SiO and 0 to 5 mol. per cent of (CH3)3 SiO 1/2 , and containing from 1 to 12% of Sibonded -OCH3 groups, and (2) from 15 to 35% of monopropylsiloxane containing from 5 to 60% of Si-bonded -OC2H5 groups. In a modification siloxane (1) may be wholly or partly replaced by a corresponding ethylsiloxane containing Si-bonded -OC2H5 groups, and in a further modification the -OC2H5 groups in siloxane (2) may be wholly or partly replaced by -OCH3 groups. Preferably, the compositions are diluted to a concentration of 2 to 5% with toluene, xylene, mineral spirits or chlorinated hydrocarbons. Examples are given. Uses.-For waterproofing masonry and fabrics and in making waterproofing compositions.ALSO:Masonry (i.e. brick, concrete, cinder block, mortar, tile, stone, stucco and equivalent materials) is rendered water-repellent by applying thereto an organic solvent (e.g. toluene, xylene, mineral spirits or chlorinated hydrocarbon) solution of a composition consisting essentially of (1) from 65 to 85% (by weight) of a methylsiloxane composed of 65 to 80 mol. per cent of CH3SiO 3/2 , 15 to 30 mol. per cent of (CH3)2SiO and 0 to 5 mol. per cent of (CH3)3SiO 1/2 , and containing from 1 to 12% of Si-bonded -OCH3 groups, and (2) from 15 to 35% of monopropylsiloxane containing from 5 to 60% of Si-bonded -OC2H5 groups (see Group IV (a)). In a modification siloxane (1) may be wholly or partly replaced by a corresponding ethylsiloxane containing Si-bonded -OC2H5 groups, and in a further modification the -OC2H5 groups in siloxane (2) may be wholly or partly replaced by -OCH3 groups. Examples are given.