Patent ID: 7976736

Claim:
A process for preparing a silver-containing, disperse, water-containing formulation containing at least a) 0.5 to 30 parts by wt. of silver metal particles with an effective diameter of at most 150 nm with a bimodal size distribution of the silver metal particles, determined using laser correlation spectroscopy, b) 50 to 99.5 parts by wt. of water and optionally up to 30 parts by wt. of solvent, c) 0.01 to 10 parts by wt. of at least one polymeric, dispersant, d) 0 to 5 parts by wt. of film-producer, e) 0 to 5 parts by wt. of additives, f) 0 to 5 parts by wt. of conductive polymers, said formulation having a viscosity of at most 150 mPa·s, comprising the steps of i) reacting a silver salt solution with a solution containing hydroxide ions, wherein at least one of said solutions comprises a polymeric dispersant, to produce an Ag 2 O sol, ii) reacting the Ag 2 O sol obtained from step i) with a reduction agent, iii) purifying the solution obtained from step ii) by centrifugation or membrane filtration.