Filler-containing silicone compositions

Abstract

The invention describes novel addition-crosslinking silicone compositions containing: (1) organosilicon compounds having radicals with aliphatic carbon-carbon multiple bonds; (2) organosilicon compounds with Si-bound hydrogen atoms; (3) the accumulation of Si-bound hydrogen at catalysts promoting aliphatic multiple bonding; and (4) as filler, silicate hollow glass micro-balls with a silver coating, wherein more than 95 wt% of the silver applied to the hollow glass micro-balls is present as metallic silver.

Description

technical field [0001] The present invention relates to filled addition-crosslinking silicone compositions which allow, inter alia, the protective encapsulation of electrical and electronic components exposed to highly corrosive environments. Background technique [0002] Silicone casting compositions are widely used to protect electronic circuits from corrosion. Today, electronic components are also increasingly exposed to particularly aggressive and harmful sulfur-containing gases. Silicone casting compositions available to date have high permeability to sulfur, hydrogen sulfide, sulfur dioxide, carbon disulfide, and other organosulfur compounds, and the resulting corrosion of metal conductor tracks leads to failure and shortened life of these components. [0003] EP 1 295 905 A1 describes silicone encapsulating compositions which contain metal powders as fillers, for example powders consisting of silver, copper, iron, nickel, aluminium, tin, and zinc, copper powder being...

AI Technical Summary

Problems solved by technology

However, the solutions presented in the above-mentioned documents, where pure metal surfaces are used, are still not sufficiently effective because only the relatively small effective surface area of ​​the metal is available for the reaction to intercept sulfur-containing gases

There are also many other disadvantages associated with this solution, such as high price, high density, and unfavorable damping characteristics

A particularly disadvantageous factor is the sedimentation of metal-containing fillers in silicone compositions, which leads to inhomogeneous filler distribution

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