Patent ID: 7381353

Claim:
A black conductive composition comprising, based on the total composition weight percent: 40-70 weight percent of conductive metal particles selected from the group consisting of gold, silver, platinum, palladium, copper and mixtures thereof; 0.5 to less than 3 weight percent of conductive metal oxide particles selected from the group consisting of RuO 2 , ruthenium polyoxide, and mixtures thereof; 25-59 weight percent organic matter comprising organic polymer binder and organic solvent; and 0.5-20 weight percent of one or more lead-free bismuth glass binders wherein said glass binder comprises, based on weight percent total glass binder composition: 55-85% Bi 2 O 3 , 0-20% SiO 2 , 0-5% Al 2 O 3 , 2-20% B 2 O 3 , 0-20% ZnO, 0-15% of one or more of oxides selected from BaO, CaO, and SrO; and 0-3% of one or more of oxides selected from Na 2 O, K 2 O, Cs 2 O, Li 2 O and mixtures thereof; and wherein the surface area to weight ratio of the conductive metal oxide is in the range of 5 to 15 m 2 /g; and wherein the softening point of said glass binder is in the range 400-600° C.; and wherein said composition is characterized by being lead-free.