Patent ID: 7608203

Claim:
A metallic colloidal solution comprising: (a) metallic particles that (a1) are deposited by reducing metallic ions in water, (a2) have a primary-particle diameter of at most 200 nm, and (a3) made of a metal selected from the group consisting of nickel, copper, silver, gold, platinum, palladium, and an alloy of these metals; (b) a dispersant having a molecular weight of 200 to 30,000; and (c) a dispersion medium made of a mixed solvent of water and a water-soluble organic solvent, wherein the water-soluble organic solvent is one of a mixture of glycol ether and alcohol and a mixture of glycol ether and keton, and the ratio of the water-soluble organic solvent to the mixed solvent is at least 70 percent, but less than 100 percent by weight.