Patent ID: 6284829
Filing Date: 2001-09-04
Classification: C08K

Abstract:
A polyorganosiloxane composition crosslinking into a silicone elastomer of high thermal conductivity and an elongation at break of greater than 30%, consisting essentially of:(1) one or more functional polyorganosiloxanes which is capable of crosslinking by a polyaddition reaction, a polycondensation reaction, or a radical reaction;(II) optionally, a polyorganohydrosiloxane;(III) a catalyst for the polyaddition reaction, a catalyst for the polycondensation reaction, or a catalyst for the radical reaction;(IV) one or more pulverulent fillers selected from the group consisting of ground quartz, Al.sub.2 O.sub.3, MgO, ZnO and their mixtures; and(V) optionally, a reinforcing filler;wherein the amount of fillers (IV) is 35 to 70% by volume of the total composition and comprises at least two groups of particles of different mean diameters, a first group having a mean particle diameter of between 10 and 40 .mu.m, present in a predominant amount in the fillers (IV), and a second group having a mean particle diameter of less than or equal to 5 .mu.m.