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US 4,374,921 AGranted
Image enhancement of photothermographic elements
AssigneeMinnesota Mining and Manufacturing Company
InventorRobert A. Frenchik
Life of this patent
Estimating the term…
Abstract
A photothermographic emulsion can be provided with enhanced image density by using an indoaniline leuco dye, aromatic carboxylic acid, and p-alkylphenyl sulfonic acid in reactive association with the emulsion.
Claims9
A photothermographic layer comprising a binder, a silver source material, photographic silver halide in catalytic proximity to said silver source material, and a reducing agent for silver ion, characterized by the fact that the reducing agent comprises at least one indoaniline leuco dye having the formula:
- ##STR11## wherein R.sup.1 =H, alkyl, alkoxy
- R.sup.2 =H, Cl
- R.sup.3 =H, Cl
- R.sup.4 =H, alkyl, alkoxy
- R.sup.5 =H, alkyl, alkoxy
- R.sup.6 =H, alkyl, alkoxy
- Q=dialkylamine, acetamide, and
- wherein at least two of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 must be H;
- which dye is in the presence of at least one aromatic carboxylic acid and at least one p-alkylphenyl sulfonic acid in reactive associate with said layer.
6 more elements
Dependencies are inferred from the claim text.