Color copying and sheet material therefor

Claim 2

A pack of sheet material useful in making full-color prints and comprised of three sheets of photosensitive sheet material each comprising a transparent thin carrier having over one surface a heat-stabilized photosensitive heat developable dry silver layer comprising (a) photosensitive silver halide catalyst-forming means and (b) heat-sensitive reactant image-forming means including an organic silver salt oxidizing agent and a reducing agent for silver ion, the oxidation-reduction reaction of which to produce a visible change is accelerated by said catalyst, and (c) a spectral sensitizer for sensitizing said sheet to a primary color, and said carrier having over the other surface a layer comprising, in a polymeric binder, a dye which is volatilizable therefrom at temperatures obtainable under thermographic copying conditions, and wherein the first of said three sheets carries a cyan dye and is sensitized to red, the second carries a magenta dye and is sensitized to green, and the third carries a yellow dye and is sensitized to blue.

Claim 3

A pack of sheets according to claim 3 wherein the dry silver layers each contain N,N''-dichloro-1,2-ethylene-bisbenzamide or N-bromosuccinimide.

Claim 4

Method of making a multicolor print comprising: (1) exposing to a light-image a pack of three sheets of photosensitive sheet material each comprising a transparent thin carrier having over one surface a heat-stabilized photosensitive heat developable dry silver layer comprising (a) photosensitive silver halide catalyst-forming means and (b) heat-sensitive reactant image-forming means including an organic silver salt oxidizing agent and a reducing agent for silver ion, the oxidation-reduction reaction of which to produce a visible change is accelerated by said catalyst, and (c) a spectral sensitizer for sensitizing said sheet to a primary color, and said carrier having over the other surface a layer comprising, in a polymeric binder, a dye which is volatilizable therefrom at temperatures obtainable under thermographic copying conditions, and wherein the first of said three sheets carries a cyan dye and is sensitized to red, the second carries a magenta dye and is sensitized to green, and the third carries a yellow dye and is sensitized to blue, with said light-image being incident on said third sheet; (2) separating the three sheets and heating each one independently to develop a visible image; and (3) separately briefly exposing each sheet to intense infra-red radiation while maintaining the dye layer against a common receptor sheet and with each sheet in registry with the position of the preceding sheet or sheets.

Claim 5

Method of claim 5 wherein the receptor sheet includes a surface coating comprising a nickel salt of an organic acid in a water-soluble binder.

Claim 6

Method of making a color print comprising: exposing to a light-image a photosensitive sheet material comprising a transparent thin carrier having over one surface a photosensitive heat developable dRy silver layer comprising (a) photosensitive silver halide catalyst-forming means, (b) heat-sensitive reactant image-forming means including an organic silver salt oxidizing agent and a reducing agent for silver ion, the oxidation-reduction reaction of which to produce a visible change is accelerated by said catalyst, and (c) N,N''-dichloro-1,2-ethylenebisbenzamide or N-bromosuccinimide, and said carrier having over the other surface a layer comprising, in a polymeric binder, a dye which is volatilizable therefrom at temperatures obtained under thermographic copying conditions; heating the exposed sheet to develop a visible image; and briefly exposing the imaged surface to intense infrared radiation while maintaining the dye-carrying surface against a receptor sheet.