Organo silyl-silica filled siloxane elastomers and process for producing same

Claim 1

A HEAT CURABLE COMPOSITION OF MATTER COMPOSED OF A BENZENE SOLUBLE ORGANOPOLYSILOXANE HAVING A VISCOSITY OF AT LEAST 10,000 CS. AT 25*C. IN WHICH SILOXANE THE ORGANIC RADICALS ARE SELECTED FROM THE GROUP CONSISTING OF METHYL, ETHYL, PHENYL, TRIFLUOROMETHYLPHENYL AND SILICONEPENTYL RADICALS, AT LEAST 50 PERCENT OF SAID RADICALS BEING ALKYL AND THERE BEING FROM 1.98 TO 2 OF SAID ORGANIC RADICALS PER SILICON ATOM AND FROM 10 TO 100 PARTS BY WEIGHT OF A FILLER BASED UPON 100 PARTS BY WEIGHT SILOXANE, SAID FILLER HAVING A PORE VOLUME OF AT LEAST 3 CCS. PER GRAM AND BEING COMPOSED OF SIO2 AND ORGANOSILYL UNITS SELECTED FROM THE GROUP CONSISTING OF RR''SI= AND R2R''SI WHERE R IS AN ALKYL RADICAL OF LESS THAN 5 CARBON ATOMS AND R4 IS SELECTED FROM THE GROUP CONSISTING OF ALKYL RADICALS OF LESS THAN 5 CARBON ATOMS AND PHENYL RADICALS, IN AMOUNT SUCH THAT THE MOLAR RATIO OF SAID ORGANOSILYL UNITS TO SIO2 IS FROM .06 TO 9, SAID ORGANOSILYL UNITS BEING ATTACHED TO THE SILICON ATOMS OF THE SIO2 THROUGH SIOSI LINKAGES.