Two corn. SiO(2) adsorbents (surface areas 90 and 380 m(2)/g, particle sizes 20 and 7 nm, resp.) were modified with cis-benzothiazine indigo by a non-solvent method with following heating at 180 degrees C. The modification resulted in a limitation of the agglomeration of SiO(2) particles. The modified SiO(2)/benzothiazine indigo composite pigments were used as fillers of ethylene-propylene copolymer crosslinked with (PhCO)(2)O(2) at 120 degrees C or with (PhCMe(2))(2)O(2) at 160 degrees C. Use of the composite filler resulted in an improvement of the mech. properties (tearing strength) of the vulcanizates.