| 摘要 |
<p>A copolymeric siloxane having a degree of substitution of from 1.9 to 2.5 inclusive organic radicals per silicon atom, and contains halogenated aryl radicals of general formula Xa C6H5-a or XbC12H9-b wherein each X is a chlorine or bromine atom, a has a value of from 1 to 5 inclusive, and b has a value of from 1 to 7 inclusive. the remaining organic radicals being monovalent hydrocarbon radicals or Cn F2n- 1 CH2CH2- radicals, wherein n has a value of from 1 to 8 inclusive, the halogenated aryl radical being present such that there are at least 0.05 x atoms per silicon atom, can be made in known manner by hydrolysing the corresponding silanes or by halogenating the corresponding phenyl or xenyl-siloxane. The halogenated aryl radicals may be of the general formula Cla C6H5-a and the remaining organic radicals are monovalent saturated or unsaturated hydrocarbon radicals. The Cla C6H5-a radicals may be present such that there are from 0.05 to 4 inclusive chlorine atoms per silicon atom, at least 30% of the organic radicals being methyl radicals and at least some of the remaining organic radicals being phenyl radicals. Specific examples are given. Uses: in solvent solution or aqueous emulsion for coating glass cloth. Specification 688,166 is referred to.ALSO:A woven glass cloth is coated with from 0,1-10% by weight calculated on the weight of the cloth of a copolymeric siloxane having a degree of substitution of from 1,9-2,5 inclusive organic radicals per silicon atom, said siloxane containing halogenated aryl radicals which are of the general formula XaC6H5-a or of the general formula XbC12H9-b, wherein each X is a chlorine or bromine atom, a has a value of from 1 to 5 inclusive and b has a value of from 1 to 7 inclusive, the remaining organic radicals in said siloxane being monovalent hydrocarbon radicals or CnF2n+1 CH2CH2- radicals, wherein n has a value of from 1 to 8 inclusive, the halogenated aryl radical being present in the siloxane in such an amount that there are at least 0,05 X atoms per silicon atom. The halogenated aryl radicals may be of the general formula ClaC6H5-a and the remaining organic radicals are monovalent hydrocarbon radicals. The ClaC6H5-a radicals may be present in the siloxane such that there are from 0,5 to 4 inclusive chlorine atoms per silicon atom, at least 30% of the organic radicals being methyl radicals and at least some of the remaining organic radicals being phenyl radicals. The woven glass cloth may take the form of a filter bag the fibres of which are coated with from 0,5-5% by weight of the glass cloth of a copolymeric siloxane having a degree of substitution of from 1,98-2,2 inclusive organic radicals per silicon atom, said siloxane containing ClaC6H-5a radicals, where a has a value of from 1 to 5 inclusive, the remaining organic radicals in said siloxane being monovalent hydrocarbon radicals, the ClaC6H5-a radicals being present in said siloxane such that there are from 0,05-0,5 inclusive chlorine atoms per silicon atom, at least 80% of the total organic radicals being methyl radicals and at least some of any remaining organic radicals being phenyl radicals. The copolymer may be applied as an emulsion or solution by spraying, dipping, brushing or flooding. Examples of copolymeric siloxanes are given. Specification 688,166 is referred to.</p> |
