# US 5,705,322 A · Method of providing an image using a negative-working infrared photosensitive element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,705,322 A - Document ID: US5705322A - Status: Granted - Kind: A - Application number: 08/723,176 - Filed: 1996-09-30 - Granted: 1998-01-06 - Earliest claimed: 1996-09-30 - Assignees: Eastman Kodak Company - Inventors: Paul Richard West; Eugene Lynn Sheriff; Jeffery Allen Gurney; Ralph Scott Schneebeli; Thomas Robert Jordan; Gary Roger Miller - Web page: https://patentgrep.com/patent/US5705322A ## CPC - B41C 1/1008: {by removal or destruction of lithographic material on the lithographic support, e.g. by laser or spark ablation; by the use of materials rendered soluble or insoluble by heat exposure, e.g. by heat produced from a light to heat transforming system; by on-the-press exposure or on-the-press development, e.g. by the fountain of photolithographic materials} - B41C 2210/04: Negative working, i.e. the non-exposed (non-imaged) areas are removed - B41C 2210/06: Developable by an alkaline solution - B41C 2210/24: characterised by a macromolecular compound or binder obtained by reactions involving carbon-to-carbon unsaturated bonds, e.g. acrylics, vinyl polymers - B41C 2210/262: Phenolic condensation polymers, e.g. novolacs, resols - Y10S 430/145: Infrared - B41C: PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES (photomechanical processes for producing printing surfaces G03F; photoelectrical processes for producing printing surfaces G03G) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract An infrared imaging composition contains two essential components, namely an infrared radiation absorbing compound, and a phenolic resin that is either mixed or reacted with an o-diazonaphthoquinone derivative. These compositions are useful in photosensitive elements such as lithographic printing plates that can be used to provide images using laser imaging, followed by uniform exposure and development. ## Claims ### Claim 1 A method for imaging a photosensitive element comprising the steps of, in order: A) providing a negative-working photosensitive element consisting essentially of a support having thereon a negative-working photosensitive composition consisting essentially of: a) (i) a mixture of a phenolic resin and an o-diazonaphthoquinone derivative, (ii) a reaction product of a phenolic resin and an o-diazonaphthoquinone reactive derivative, or (iii) a mixture of (i) and (ii), and b) a compound that absorbs infrared radiation having a maximum wavelength greater than about 750 nm, B) without prior floodwise exposure to light, imagewise exposing said element with an infrared emitting laser, C) floodwise exposing said element, and D) contacting said element with an aqueous developing solution to remove the non-image areas of said photosensitive layer. ### Claim 2 (depends on 1) The method of claim 1 wherein a) is said reaction product (ii). ### Claim 3 (depends on 1) The method of claim 1 wherein said phenolic resin is a novolac resin. ### Claim 4 (depends on 1) The method of claim 1 wherein said o-diazonaphthoquinone reactive derivative is a sulfonic acid or carboxylic acid ester of o-diazonaphthoquinone. ### Claim 5 (depends on 1) The method of claim 1 wherein said o-diazonaphthoquinone derivative is 2,4-bis(2-diazo-1,2-dihydro-1-oxo-5-naphthalenesulfonyloxy)benzophenone, 2-diazo-1,2-dihydro1-oxo-5-naphthalenesulfonyloxy-2,2-bis(hydroxyphenyl) propane monoester, the hexahydroxybenzophenone hexaester of 2-diazo-1,2-dihydro-1-oxo-5-naphthalenesulfonic acid, 2,2'-bis(2-diazo-1,2-dihydro1-oxo-5-naphthalenesulfonyloxy)biphenyl, 2,2',4,4'-tetrakis(2-diazo-1,2-dihydro1-oxo-5-naphthalenesulfonyloxy)biphe nyl, 2,3,4-tris(2-diazo-1,2-dihydro1-oxo-5-naphthalenesulfonyloxy)benzophenone, 2,4-bis(2-diazo-1,2-dihydro1-oxo-4-naphthalenesulfonyloxy)benzophenone, 2-diazo-1,2-dihydro-1-oxo-4-naphthalenesulfonyloxy-2,2-bis hydroxyphenylpropane monoester, the hexahydroxybenzophenone hexaester of 2-diazo-1,2-dihydro-1-oxo-4-naphthalenesulfonic acid, 2,2'-bis(2-diazo-1,2-dihydro1-oxo-4-naphthalenesulfonyloxy)biphenyl, 2,2',4,4'-tetrakis(2-diazo-1,2-dihydro1-oxo-4-naphthalenesulfonyloxy)biphe nyl or 2,3,4-tris(2-diazo-1,2-dihydro1-oxo-4-naphthalenesulfonyloxy)benzophenone. ### Claim 6 (depends on 1) The method of claim 1 wherein the o-diazonaphthoquinone reactive derivative in said mixture has a non-polymeric ballast group having a molecular weight of at least about 15. ### Claim 7 (depends on 1) The method of claim 1 wherein said infrared radiation absorbing compound is a squarylium, croconate, cyanine, merocyanine, indolizine, pyrylium or metal dithiolene dye or pigment that absorbs infrared radiation at a wavelength of from about 800 to about 1100 nm. ### Claim 8 (depends on 1) The method of claim 1 wherein said infrared radiation absorbing compound is present in an amount sufficient to provide an optical density of at least 0.5. ### Claim 9 (depends on 8) The method of claim 8 wherein said infrared radiation absorbing compound is present in an amount sufficient to provide an optical density of from about 1 to about 3. ### Claim 10 (depends on 1) The method of claim 1 wherein said support is a sheet of grained and anodized aluminum. ### Claim 11 A method for imaging a photosensitive element comprising the steps of, in order: A) providing a negative-working photosensitive element consisting essentially of a grained and anodized aluminum support having thereon, as the outer layer, a single negative-working layer comprising a photosensitive composition consisting essentially of a reaction product of a phenol-formaldehyde novolac resin and 2-diazo-1,2-dihydro1-oxo-4 or 5-naphthalenesulfonyl chloride, and a cyanine dye that absorbs infrared radiation having a wavelength of from about 800 to about 1100 nm, B) without prior floodwise exposure to light, imagewise exposing the element with an infrared emitting laser at an intensity at the photosensitive layer surface of from about 10 to about 1000 milliwatts/mm, C) floodwise exposing said element, and D) contacting said element with an aqueous developing solution to remove the non-image areas of said photosensitive layer. ### Claim 12 (depends on 11) The method of claim 11 wherein said aqueous developing solution is an alkaline solution. ### Claim 13 (depends on 11) The method of claim 11 wherein said o-diazonaphthoquinone reactive derivative is 2-diazo-1,2-dihydro1-oxo-5-naphthalenesulfonyl chloride. ### Claim 14 (depends on 11) The method of claim 11 wherein said infrared radiation absorbing compound is a cyanine dye.