# US 5,352,561 A · Thermal solvents for heat image separation processes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,352,561 A - Document ID: US5352561A - Status: Granted - Kind: A - Application number: 08/049,048 - Filed: 1993-04-16 - Granted: 1994-10-04 - Earliest claimed: 1991-12-06 - Assignees: Eastman Kodak Company - Inventors: David S. Bailey; Ronald H. White; John Texter - Web page: https://patentgrep.com/patent/US5352561A ## CPC - G03C 8/402: {Transfer solvents therefor} - Y10S 430/156: Precursor compound - G03C: PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES (for photomechanical purposes G03F); PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY (photographic processes characterised by the use or manipulation of apparatus classifiable per se in subclass G03B, see G03B; photomechanical production of textured or patterned surfaces G03F; electrophotography, magnetography G03G) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A process is disclosed for forming an improved dye image in an aqueous-developable photographic dry dye-diffusion transfer element comprising the steps of: providing an aqueous-developable chromogenie photographic dry dye-diffusion transfer element comprising radiation sensitive silver halide, an aqueous-developable material containing color coupler wherein said coupler forms or releases a heat-transferable dye upon reaction of said coupler with the oxidation product of a primary amine developing agent, a hydrophilic binder, and a thermal solvent wherein said thermal solvent has the structure I ##STR1## wherein (a) Z.sub.1, Z.sub.2, Z.sub.3, Z.sub.4, and Z.sub.5 are substituents, the Hammer sigma parameters of Z.sub.2, Z.sub.3, and Z.sub.4 sum to give a total, .SIGMA., of at least -0.28 and less than 1.53; (b) the calculated IogP for I is greater than 3 and less than 10; exposing said dye-diffusion transfer element to actinic radiation; contacting said dye-diffusion transfer element with an aqueous-developing solution, wherein said aqueous-developing solution comprises a primary amine developing agent; contacting said dye-diffusion transfer element with an aqueous stop bath; drying said dye-diffusion transfer element; providing a dye-receiving layer and contiguous support, where said dye-receiving layer is in physical contact with said dye-diffusion transfer element; heating said dye-diffusion transfer element and dye-receiving layer to effect dye-diffusion transfer; and separating said dye-receiving layer and contiguous support from said dye-diffusion transfer element. ## Claims ### Claim 1 A process for forming an improved dye image in an aqueous-developable photographic dry dye-diffusion transfer element comprising the steps of: providing an aqueous-developable chromogenic photographic dry dye-diffusion transfer element comprising radiation sensitive silver halide, an aqueous-developable material containing color coupler wherein said coupler forms or releases a heat-transferable dye upon reaction of said coupler with the oxidation product of a primary amine developing agent, a hydrophilic binder, and a thermal solvent wherein said thermal solvent has the structure I ##STR10## wherein (a) Z.sub.1, Z.sub.2, Z.sub.3, Z.sub.4, and Z.sub.5 are substituents, the Hammet sigma parameters of Z.sub.2, Z.sub.3, and Z.sub.4 sum to give a total, .SIGMA., of at least -0.28 and less than 1.53; (b) the calculated logP for I is greater than 3 and less than 10; exposing said dye-diffusion transfer element to actinic radiation; contacting said dye-diffusion transfer element with an aqueous-developing solution, wherein said aqueous-developing solution comprises a primary amine developing agent; contacting said dye-diffusion transfer element with an aqueous stop bath; drying said dye-diffusion transfer element; providing a dye-receiving layer and contiguous support, where said dye-receiving layer is in physical contact with said dye-diffusion transfer element; heating said dye-diffusion transfer element and dye-receiving layer to effect dye-diffusion transfer; and separating said dye-receiving layer and contiguous support from said dye-diffusion transfer element. ### Claim 2 (depends on 1) The process of claim 1, wherein the total of said hydrophilic binder amounts to from 3 to 20 g/m.sup.2 of said dye-diffusion transfer element. ### Claim 3 (depends on 1) The process of claim 1, wherein said hydrophilic binder is gelatin. ### Claim 4 (depends on 1) The process of claim 1, wherein the amount of said thermal solvent incorporated in a given layer is 1 to 300% by weight of the total amount of hydrophilic binder present in said layer. ### Claim 5 (depends on 1) The process of claim 1, wherein the amount of said thermal solvent incorporated in a given layer is 50 to 120% by weight of the total amount of hydrophilic binder present in said layer. ### Claim 6 (depends on 1) The process of claim 1, wherein said thermal solvent comprises 3-hydroxy benzoic acid esters. ### Claim 7 (depends on 1) The process of claim 1, wherein said thermal solvent comprises 4-hydroxy benzoic acid esters. ### Claim 8 (depends on 1) The process of claim 1, wherein said thermal solvent comprises 3-hydroxy benzamides or 4-hydroxy benzamides. ### Claim 9 (depends on 1) The process of claim 1, wherein the sum of the Hammer sigma parameters Z.sub.2, Z.sub.3, and Z.sub.4, .SIGMA., is in the range 0.35 to 0.90. ### Claim 10 (depends on 1) The process of claim 1, wherein the calculated logP for I is greater than 4.5 and less than 8. ### Claim 11 A process for forming an improved dye image in an aqueous-developable photographic dry dye-diffusion transfer element comprising the steps of: providing an aqueous-developable chromogenie photographic dry dye-diffusion transfer element comprising radiation sensitive silver halide, an aqueous-developable material containing color coupler wherein said coupler forms or releases a heat-transferable dye upon reaction of said coupler with the oxidation product of a primary amine developing agent, a hydrophilic binder, and a thermal solvent wherein said thermal solvent has the structure I ##STR11## wherein (a) Z.sub.1, Z.sub.2, Z.sub.3, Z.sub.4, and Z.sub.5 are substituents, the Hammet sigma parameters of Z.sub.2, Z.sub.3, and Z.sub.4 sum to give a total, .SIGMA., of at least -0.28 and less than 1.53; (b) the calculated logP for I is greater than 3 and less than 10; (c) said thermal solvent is selected from the group consisting of 3-hydroxy benzoic acid esters and 4-hydroxybenzoic acid esters; exposing said dye-diffusion transfer element to actinic radiation; contacting said dye-diffusion transfer element with an aqueous-developing solution, wherein said aqueous-developing solution comprises a primary amine developing agent; contacting said dye-diffusion transfer element with an aqueous stop bath; drying said dye-diffusion transfer element; providing a dye-receiving layer and contiguous support, where said dye-receiving layer is in physical contact with said dye-diffusion transfer element; heating said dye-diffusion transfer element and dye-receiving layer to effect dye-diffusion transfer; and separating said dye-receiving layer and contiguous support from said dye-diffusion transfer element.