Polymer-containing mixture

摘要

A polymer-containing mixture contains polyborosiloxane having a molecular weight of 2000-5000, which contains the structural units <IMAGE> in a B/Si molar ratio of from 1:4 to 5, siloxane rubber, organic polymer, polyorganosiloxane, silicon dioxide and oxides of metals of varying valency from the group consisting of chromium, iron and titanium. The mixture contains, as organic polymer, polyolefins, copolymers of olefins with dienes, halogenated polyolefins, halogenated copolymers of olefins with dienes, alone or in combination with one another. As polyorganosiloxane, it contains branched polyorganosiloxane having a molecular weight of from 2000 to 2500, containing structural units of the formula <IMAGE> in which R is methyl or phenyl, a is from 43 to 50 mol %, b is from 0 to 2 mol %, c is from 50 to 55 mol %, with the following ratio of the components: from 8 to 20 parts by weight of polyborosiloxane, from 40 to 90 parts by weight of siloxane rubber, from 5 to 60 parts by weight of organic polymer, from 2 to 10 parts by weight of polyorganosiloxane, from 10 to 25 parts by weight of silicon dioxide and from 5 to 10 parts by weight of oxides of said metals. The mixture can be used to produce thermally stable insulating materials.