Patent ID: 6296999
Filing Date: 2001-10-02
Classification: G03C

Abstract:
A substantially light-insensitive black and white thermographic material comprising(a) a polymeric or polymer-coated support;(b) a subbing layer on said support,(i) wherein said subbing layer includes a subbing layer binder selected from the group consisting of polymer latex, polysilicic acid, melamine-formaldehyde resin, hydrolyzed polyalkoxysilanes and any mixture thereof, and when said binder contains covalently bonded acid groups said acid groups are substantially present as free acids or substantially present as acid salts,(ii) wherein said subbing layer has a leachable non-fluoro-halide ion content into water at room temperature over a period of 120 minutes of less than 0.6 mg/m.sup.2, and(iii) wherein said subbing layer contains silica and less than 20% by weight of said subbing layer is silica,(c) a thermosensitive element on the same side of said support as said subbing layer, said thermosensitive element containing(i) a substantially light-insensitive organic silver salt,(ii) a reducing agent for the reduction of the substantially light-insensitive organic silver salt, and(iii) a thermosensitive element binder.