US 6,284,829 B1Granted

Silicone elastomer of high thermal conductivity

AssigneeRhodia Chimie

InventorsBernard Dalbe, Yves Giraud

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Abstract

The polyorganosiloxane composition resulting in a silicone elastomer of high thermal conductivity, which can reach and even exceed 1.2 W/m.K, the elastomer retaining an elongation at break of greater than 30%, comprises at least one functional polyorganosiloxane which crosslinks by a polyaddition or polycondensation reaction or by the radical route, optionally a polyorganohydrosiloxane, a catalyst, optionally a reinforcing filler and a filler intended to increase the thermal conductivity which is present in the composition in the proportion of 35 to 70% by volume with respect to the total composition, this filler comprising at least two groups of particles of very different mean diameters, a first group having a mean particle diameter of between 10 and 40 mm, present in a predominant amount in the filler, and a second group having a mean particle diameter of less than 5 mm.

Claims13

Dependent claims

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, Al2O3, 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 μm, 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 μm.

4 more elements

Dependencies are inferred from the claim text.