Photographic products and processes employing triarylmethane compounds
AssigneePolaroid Corporation
InventorJames W. Foley
Life of this patent
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Abstract
The present invention is concerned with photographic products and processes, particularly diffusion transfer products and processes employing certain colored triarylmethane compounds possessing in their triaryl structure a 4'-oxo-1'-naphthylidene (or a 4'-oxo-1'-phenylidene) moiety, a naphthyl (or phenyl moiety) and a phenyl moiety substituted in the ortho-position to the central carbon atom with a non-nucleophilic group that cannot add to the central carbon atom but in alkaline solution undergoes an irreversible cleavage reaction with base that is complete within a predetermined time at a predetermined alkaline pH to provide a nucleophilic moiety that adds to the central carbon atom to form a ring-closed compound which is colorless.
Claims62
A photographic product comprising a plurality of layers including a support and at least one photosensitive silver halide emulsion layer carried on said support, at least one of said layers containing a colored triarylmethane compound possessing in its triarylmethane structure a 4'-oxo-1'-naphthylidene or a 4'-oxo-1'-phenylidene moiety;
- a naphthyl moiety or a phenyl moiety;
- and a phenyl moiety substituted in the ortho-position to the central carbon atom of said triarylmethane compound with a non-nucleophilic group that cannot add to said central carbon atom but in alkaline solution undergoes an irreversible cleavage reaction with base that is complete within a predetermined time at a predetermined alkaline pH to provide a nucleophilic moiety that adds to said central carbon atom to form a ring-closed compound which is colorless.
A photographic product for forming a multicolor diffusion transfer image, said product comprising a first sheet-like element comprising a first support carrying a red-sensitive silver halide emulsion layer, a green-sensitive silver halide emulsion layer, and a blue-sensitive silver halide emulsion layer, said silver halide emulsion layers having associated therewith, respectively, a cyan image dye-providing material, a magenta image dye-providing material and a yellow image dye-providing material;
- a second sheet-like element comprising a second support;
- said first and second sheet-like elements being in superposed relationship, or adapted to be brought into superposed relationship, with said supports being outermost;
- at least one of said supports being transparent to permit photoexposure of said silver halide emulsions therethrough;
- a rupturable container releasably holding an aqueous alkaline processing composition, said rupturable container being so positioned as to be capable of discharging said processing composition between a pair of predetermined layers carried by said supports;
- an image-receiving layer carried by one of said supports;
- and a colored triarylmethane compound being disposed in a processing composition permeable layer carried by one of said supports, said triarylmethane compound possessing in its triarylmethane structure a 4'-oxo-1'-naphthylidene or a 4'-oxo-1'-phenylidene moiety;
- a naphthyl moiety or a phenyl moiety;
- and a phenyl moiety substituted in the ortho-position to the central carbon atom of said triarylmethane compound with a non-nucleophilic group that cannot add to said central carbon atom but in alkaline solution undergoes an irreversible cleavage reaction with base that is complete within a predetermined time at a predetermined alkaline pH to provide a nucleophilic moiety that adds to said central carbon atom to form a ring-closed compound which is colorless.
A photographic process which comprises the steps of exposing a photosensitive film comprising a plurality of layers including at least one photosensitive silver halide emulsion layer carried on a support, at least one of said layers containing a colored triarylmethane compound possessing in its triarylmethane structure a 4'-oxo-1'-naphthylidene or a 4'-oxo-1'-phenylidene moiety;
- a naphthyl moiety or a phenyl moiety;
- and a phenyl moiety substituted in the ortho-position to the central carbon atom of said triarylmethane compound with a non-nucleophilic group that cannot add to said central carbon atom but in alkaline solution undergoes an irreversible cleavage reaction but with base that is complete within a predetermined time at a predetermined alkaline pH to provide a nucleophilic moiety that adds to said central carbon atom to form a ring-closed compound which is colorless and contacting said photosensitive silver halide emulsion layer(s) with an aqueous alkaline processing composition having an alkaline pH to effect development.
A photographic process which comprises, in combination, the steps of:
- (a) exposing a photosensitive film unit comprising a plurality of layers including a support carrying at least one photosensitive silver halide emulsion layer having associated therewith an image-providing material, an image-receiving layer adapted to receive a solubilized image-providing material diffusing thereto, at least one of said layers on the same side of said support as said silver halide layer(s) containing a colored triarylmethane compound possessing in its triarylmethane structure a 4'-oxo-1'-naphthylidene or a 4'-1'-phenylidene moiety;
- a naphthyl moiety or a phenyl moiety;
- and a phenyl moiety substituted in the ortho-position to the central carbon atom of said triarylmethane compound with a non-nucleophilic group that cannot add to said central carbon atom but in alkaline solution undergoes an irreversible cleavage reaction with base that is complete within a predetermined time at a predetermined alkaline pH to provide a nucleophilic moiety that adds to said central carbon atom to form a ring-closed compound which is colorless;
- (b) contacting said silver halide layer(s) and said colored compound with a processing composition having an alkaline pH at least as high as said predetermined pH;
- (c) effecting thereby development of said silver halide layer(s);
- (d) maintaining the pH of said processing composition in contact with said colored compound at least as high as said predetermined alkaline pH for a time sufficient to effect irreversible cleavage of said non-nucleophilic group whereby said colored compound is converted to said colorless ring-closed compound;
- (e) forming as a result of said development, an imagewise distribution of diffusible image-providing material;
- and
- (f) transferring, by diffusion, at least a portion of said imagewise distribution of diffusible image-providing material to said layer adapted to receive said material to provide a transfer image thereto.
A photographic process for forming a multicolor diffusion transfer image which comprises the steps of:
- (a) exposing a photosensitive film unit which includes, in combination, a first sheet-like element comprising a first support carrying a red-sensitive silver halide emulsion layer, a green-sensitive silver halide emulsion layer, and a blue-sensitive silver halide emulsion layer, said silver halide emulsion layers having associated therewith, respectively, a cyan image dye-providing material, a magenta image dye-providing material and a yellow image dye-providing material;
- a second sheet-like element comprising a second support;
- said first and second sheet-like elements being in superposed relationship, or adapted to be brought into superposed relationship, with said supports being outermost;
- at least one of said supports being transparent to permit photoexposure of said silver halide emulsions therethrough;
- a rupturable container releasably holding an aqueous alkaline processing composition, said rupturable container being so positioned as to be capable of discharging said processing composition between a pair of predetermined layers carried by said supports;
- an image-receiving layer carried by one of said supports;
- and a colored compound disposed in a processing composition permeable layer carried by one of said supports, said colored compound being a triarylmethane compound possessing in its triarylmethane structure a 4'-oxo-1'-naphthylidene or a 4'-oxo-1'-phenylidene moiety;
- a naphthyl moiety or a phenyl moiety;
- and a phenyl moiety substituted in the ortho-position to the central carbon atom of said triarylmethane compound with a non-nucleophilic group that cannot add to said central carbon atom but in alkaline solution undergoes an irreversible cleavage reaction with base that is complete within a predetermined time at a predetermined alkaline pH to provide a nucleophilic moiety that adds to said central carbon atom to form a ring-closed compound which is colorless;
- (b) contacting said silver halide layer(s) and said colored compound with a processing composition having an alkaline pH at least as high as said predetermined pH;
- (c) effecting thereby development of said silver halide layer(s);
- (d) maintaining the pH of said processing composition in contact with said colored compound at least as high as said predetermined alkaline pH for a time sufficient to effect irreversible cleavage of said non-nucleophilic group whereby said colored compound is converted to said colorless ring-closed compound;
- (e) forming as a result of said development, an imagewise distribution of diffusible image dye-providing material;
- and
- (f) transferring, by diffusion, at least a portion of said imagewise distribution of diffusible image dye-providing material to said image-receiving layer to provide a transfer image thereto.
Dependencies are inferred from the claim text.