Polaroid Corporation

Alan L Borror

Ernest W Ellis

James W Foley

Stanley M Bloom

Louis Cincotta

Richard B Greenwald

John W Lee, Jr

Donald A McGowan

Marcis M Kampe

David P Waller

Patrick R Conlon

Roger A Boggs

Richard L Cournoyer

Michael H Feingold

Ruth Linda Hill

Edmond M Mahoney

Charles E Hammond

Efthimios Chinoporos

Hugh R MacKenzie

Cheryl P Petersen

Paulina P Garcia

Paul S Huyffer

Bernard Zuckerman

Faramarz Faramarzpour

Colorless precursors of preformed image dyes are provided which are useful as the color image-forming materials in thermal imaging systems. These colorless precursors possess at least one thermal protecting group that undergoes fragmentation upon heating and at least one leaving group that undergoes irreversible elimination upon heating, said protecting and leaving groups maintaining the precursor in its colorless form until heat is applied to effect removal of these groups whereby the precursor is converted to an image dye.

Thermal imaging dye precursors

A thermal imaging method for forming color images is provided which employs as the color image-forming material, a colorless precursor of a preformed image dye possessing at least one thermal protecting group that undergoes fragmentation upon heating and at least one leaving group that undergoes irreversible elimination upon heating, said protecting and leaving groups maintaining the precursor in its colorless form until heat is applied to effect removal of these groups whereby the precursor is converted to an image dye.

Thermal imaging method

A thermal imaging method is provided which comprises heating imagewise a di- or triarylmethane compound possessing within its di- or triarylmethane structure an aryl group substituted in the ortho position to the meso carbon atom with a moiety ring-closed on the meso carbon atom directly through a nitrogen atom, which nitrogen atom is also bound to a group with a masked acyl substituent that undergoes fragmentation upon heating to liberate the acyl group for effecting intramolecular acylation of said nitrogen atom to form a new group in the ortho position whereby the di- or triarylmethane compound is rendered colored in an imagewise pattern corresponding to said imagewise heating.

This invention relates to a color-shifted dye compounds containing at least one thermally unstable carbamate moiety which are useful in thermal imaging. These compounds may be represented by the formula [M--(X).sub.q ].sub.p D wherein M is a carbamate moiety; X is --N.dbd., --SO.sub.2 -- or --CH.sub.2 --; D taken with X and M represents the radical of a color-shifted organic dye, said carbamate moiety M comprising a tert-alkoxycarbonyl group, ##STR1## wherein R' is halomethyl or alkyl.

Color-shifted dyes with thermally unstable carbamate moiety comprising

A thermal imaging method is provided which employs as color-forming co-reactants, (a) a substantially colorless di- or triarylmethane compound possessing on the meso carbon atom within its triarylmethane structure an aryl group substituted in the ortho position with a nucleophilic moiety which is ring-closed on the meso carbon atom and (b) an electrophilic reagent which upon heating and contacting said di- or triarylmethane compound undergoes a bimolecular nucleophilic substitution reaction with the nucleophilic moiety to form a colored, ring-opened di- or triarylmethane compound.

An identification card comprises a single media having a plurality of different heat sensitive image forming dye compounds on which are encoded a colored pictorial image of the card holder, colored text, and machine readable digital data. A laser printing method is also provided for activating the heat sensitive image forming dyes to provide the colored pictorial image of the card holder, the colored text and the machine readable digital code.

Optical storage identification card and read/write system

In one embodiment, the present invention is concerned with novel xanthene compounds of the formula ##STR1## wherein each R.sup.1 is the same and is selected from ##STR2## R.sup.2 is alkyl, R.sup.3 is an electron-withdrawing group positioned ortho, meta or para to said N atom, R.sup.4 is hydrogen, alkyl or an electron-withdrawing group positioned ortho, meta or para to said N atom; R.sup.5 is alkyl; X is hydrogen, an electron-withdrawing group or an electron-donating group; and A is an anion. In another embodiment, the present invention is concerned with photographic products and processes employing these xanthene compounds, e.g., as photographic light-screening dyes.

Novel xanthene compounds and their photographic use

This invention relates to diffusion transfer photographic processes adapted to be performed in the presence of ambient light and to diffusion transfer products useful in such processes wherein enhanced opacification particularly, in the green region of the visible spectrum is achieved by employing a 7-sulfonamido/5- or 6-sulfamoyl indole phthalein as the light-absorbing, pH-sensitive optical filter agent for the shorter wavelength region of the visible spectrum.

Color transfer photographic processes and products with indole phthalein

A thermal imaging method for forming color images is provided which relies upon the irreversible unimolecular fragmentation of one or more thermally unstable carbamate moieties of an organic compound to effect a visually discernible color shift from colorless to colored, from colored to colorless or from one color to another.

This invention relates to photographic products and processes employing silver halide solvent precursors of the formula ##STR1## wherein R.sup.1 is a monovalent organic radical; R.sup.2 is hydrogen or a monovalent organic radical; Z is a moiety that undergoes .beta.-elimination in aqueous alkaline solution and preferably is a moiety that undergoes .beta.-elimination in aqueous alkaline solution to release a photographically useful reagent; and n is an integer 3, 4 or 5.

Photographic products

Photographic products and processes with silver halide solvent precursors

This invention relates to photographic products and processes employing silver halide solvent precursors of the formulae ##STR1## wherein R.sup.1 and R.sup.2, the same or different, each are hydrogen, alkyl, phenalkyl, phenyl or phenyl substituted with an electron-donating or electron-withdrawing group; R.sup.3 is alkyl, phenalkyl, phenyl or substituted phenyl; Z is --CN or --SO.sub.2 R.sup.4 wherein R.sup.4 is branched-chain alkyl, phenalkyl, phenyl or substituted phenyl; and n is an integer 3, 4 or 5.

Novel photographic products and processes

In one aspect, this invention relates to a method of synthesizing certain 3-(4'-OH-carbocyclic aryl)-3-(carbocyclic aryl)-2,3-dihydrobenz[d]isothiazole-1,1-dioxides (and -2,3-dihydronaphtho[1,8-de]-1,2-thiazine-1,1-dioxides) by reacting a 3-(4'-OP-carbocyclic aryl)-3-(carbocyclic aryl)-2,3-dihydrobenz[d]isothiazole-1,1-dioxide (or a 3-(4'-OP-carbocyclic aryl)-3-(carbocyclic aryl)-2,3-dihydronaphtho[1,8-de]-1,2-thiazine-1,1-dioxide) wherein P is a protecting group with a carboxylic acid halide in pyridine to yield the corresponding 2-carbonyl derivative followed by removing the protecting group with weak acid to give the product. Optionally, the acylation step may be carried out by sequentially reacting the starting compound with an alkali metal hydride to give the corresponding 2-alkali metal salt and then reacting with the carboxylic acid halide in a suitable inert organic solvent. The products produced comprise phenol and 1-naphthol sulfam(na)phthaleins useful, for example, as photographic optical filter agents and filter agent precursors. In another aspect, the present invention relates to the carbonyl-substituted and alkali metal-substituted 2,3-dihydrobenz[d]isothiazole-1,1-dioxides and 2,3-dihydronaphtho[1,8-de]-1,2-thiazine-1,1-dioxides produced as intermediates in the above synthesis.

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Lexington, MA, United States of America

Alan L Borror