Patent ID: 6300052
Filing Date: 2001-10-09
Classification: G03C

Abstract:
A process for producing a substantially light-insensitive black and white thermographic material, comprising a support and a thermosensitive element which comprises a substantially light-insensitive organic silver salt, a reducing agent therefor in substantial working relationship therewith and a binder, wherein said binder is a water-dispersible film-forming polymer having monomer units comprising covalently bonded ionic groups selected from the group consisting of sulfonate, sulfinate, carboxylate, phosphate, quaternary ammonium, tertiary sulfonium, and quaternary phosphonium groups, said process comprising:(i) producing an aqueous dispersion of particles of the substantially light-insensitive silver salt;(ii) modifying said dispersion of the silver salt into another aqueous dispersion comprising the silver salt, the reducing agent, and the binder; and(iii) coating the aqueous dispersion recited in step (ii) onto the support.