Photographic emulsions and elements capable of forming direct-positive images
AssigneeEastman Kodak Company
InventorsRoger M. Baralle, Marcel A. Compere, Maurice E. Pfaff, Frederic X. Jordi, Claude G. Goumont
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Abstract
Silver halide emulsions are disclosed containing silver halide grains capable of forming an internal latent image. Incorporated in the emulsions as a nucleating agent is a heterocyclic compound having an arylaminovinylene or aryloxyvinylene substituent, thereby permitting a direct-positive image to be formed on imagewise exposure and photographic processing.
Claims21
A silver halide emulsion comprised of silver halide grains capable of forming an internal latent image and, adsorbed to the surface of said silver halide grains, a nucleating amount of a compound of the formula ##STR16## wherein Z.sup.1 represents the atoms completing an aromatic carbocyclic nucleus of from 6 to 10 carbon atoms;
- Y.sup.1 amd Y.sup.2 are independently selected from among a divalent oxygen atom, a divalent sulfur atom, and ##STR17## Z.sup.2 represents the atoms completing a heterocylclic nucleus of the type found in cyanine dyes;
- A is an adsorption promoting moiety;
- m and n are 1 or 2;
- and
- R.sup.1, R.sup.2, and R.sup.3 are independently chosen from the group consisting of hydrogen, alkyl, aryl, alkaryl, and aralkyl and R.sup.1 and R.sup.3 are additionally independently chosen from the group consisting of acyl, alkenyl, and alkynyl, the aliphatic moieties containing up to 5 carbon atoms and the aromatic moieties containing 6 to 10 carbon atoms.
In a photographic element capable of forming direct-reversal photographic images comprised of a support, a red responsive cyan dye image-forming layer unit, a green responsive magenta dye image-forming layer unit, and a blue responsive magenta dye image-forming layer, each of said layer units containing silver halide grains capable of forming an internal latent image and, adsorbed to the surface of the silver halide grains, a nucleating agent,
- the improvement comprising said nucleating agent being of the formula ##STR23## wherein Z.sup.1 represents the atoms completing an aromatic carbocyclic nucleus of from 6 to 10 carbon atoms;
- Y.sup.1 and Y.sup.2 are independently selected from among a divalent oxygen atom, a divalent sulfur atom, and ##STR24## Z.sup.2 represents the atoms completing a heterocyclic nucleus of the type found in cyanine dyes;
- A is an adsorption promoting moiety;
- m and n are 1 or 2;
- and
- R.sup.1, R.sup.2, and R.sup.3 are independently chosen from the group consisting of hydrogen, alkyl, aryl, alkaryl, and aralkyl and R.sup.1 and R.sup.3 are additionally independently chosen from the group consisting of acyl, alkenyl, and alkynyl, the aliphatic moieties containing up to 5 carbon atoms and the aromatic moieties containing 6 to 10 carbon atoms.
Dependencies are inferred from the claim text.