Polyfunctional alkoxy endblocked polysiloxanes and their cured compositions

Abstract

.Iadd.A siloxane of the formula .Iadd. ##STR1##.Iaddend. WHICH CAN BE CURED BY MIXING WITH A CATALYST AND USED AS A SILOXANE RUBBER FOR A COATING, A SEALANT OR CAULK.

That which is claimed is: 
     
       1. A composition of matter consisting essentially of a siloxane of the formula ##STR42## in which R is selected from the group consisting of monovalent haloaliphatic hydrocarbon radicals having no halogen on the carbon alpha to the oxygen and monovalent aliphatic hydrocarbon radicals both of said radicals having from 1 to 8 inclusive carbon atoms, both R' and R" are each selected from the group consisting of monovalent hydrocarbon radicals, monovalent halohydrocarbon radicals and monovalent cyanoalkyl radicals all of from 1 to 18 carbon atoms, n has an average value from 2 to 3 inclusive, y has an average value from 1.99 to 2 inclusive, z has an average value from 1 to 1.01 inclusive and the sum of y+z is 3 and x has a value of at least 7. 
     
     
       2. A composition in accordance with claim 1 where R, R' and R" are all methyl radicals. .[.3. A curable composition of matter which is stable in the absence of moisture but which will cure upon exposure to atmospheric moisture consisting essentially of (1) a siloxane in which the molecules are essentially of the formula ##STR43## in which R is selected from the group consisting of monovalent haloaliphatic hydrocarbon radicals having no halogen on the carbon alpha to the oxygen and monovalent aliphatic hydrocarbon radicals both of said radicals having from 1 to 8 inclusive carbon atoms, R' and R" each are selected from the group consisting of monovalent hydrocarbon radicals, monovalent halohydrocarbon radicals and monovalent cyanoalkyl radicals, all of from 1 to 18 inclusive carbon atoms, n has an average value from 2 to 3 inclusive, y has an average value from 1.99 to 2 inclusive, z has an average value from 1 to 1.01 inclusive and the sum of y+z is 3 and x has a 
     
     
        value of at least 7 and (2) a curing catalyst for the siloxane..]. .[.4. A composition in accordance with claim 3 which also includes a filler..]. .[.5. A composition in accordance with claim 3 in which R, R' and R" are all methyl radicals..]. .[.6. The method of forming a cured material which comprises exposing the composition of claim 3 to moisture..].