Sealing compositions for electric cables

Claim 1

A sealing composition for electric wires comprising: a binder component; and an inorganic, water-insoluble, powdered filler material; wherein: a. the binder component is a combination of two binders--binder I (in an amount of 70-97 wt. %), and binder II (in an amount of 3-30 wt. %); a.1 binder I is a homopolymer of 1,3-butadiene or a copolymer based on 1,3-butadiene (in an amount of ≧80 wt. %) and at least one other copolymerizable 1,3-diene or 1,3-cyclodiene or at least one other copolymerizable alpha-olefin (in an amount of ≦20 wt. %) (with the indicated composition of the said copolymer determined by IR analysis); the average relative molecular weight (referred to hydrogen), Mn, of the homopolymer or copolymer is 500 to 5,000, and its viscosity (at 20° C. according to DIN 53 015) is 2-80 dPa-sec; a.2 binder II is a polymer based on 1,3-butadiene with laterally extending succinic anhydride groups (i.e., a maleinized polymer based on 1,3-butadiene) with an acid number of 15 to 150 (mg KOH/g); this polymer being prepared by adding maleic anhydride to a polymer of the type of binder I (feature a.1); and b. the filler material is comprised of at least 80 wt. % of an alkaline earth carbonate which has not been provided with a hydrophobic coating and which is capable of reacting with the anhydride groups of binder II; said filler being present in an amount of 65-80 wt. % of the total sealing composition.