# US 5,347,301 A · Transfer-type electrothermographic recording method and recording medium for use with the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,347,301 A - Document ID: US5347301A - Status: Granted - Kind: A - Application number: 08/020,463 - Filed: 1993-02-22 - Granted: 1994-09-13 - Earliest claimed: 1989-08-23 - Assignees: Ricoh Company, Ltd. - Inventors: Toshiyuki Kawanishi; Kunichika Morohoshi; Masato Igarashi - Web page: https://patentgrep.com/patent/US5347301A ## CPC - G03G 5/028: Layers in which after being exposed to heat patterns electrically conductive patterns are formed in the layers, e.g. for thermoxerography - G03G 5/02: Charge-receiving layers (G03G5/153 takes precedence) - G03G 15/32: in which the charge pattern is formed dotwise, {e.g. by a thermal head}(G03G15/04, G03G15/05, G03G15/34 take precedence) - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A transfer-type electrothermographic recording method comprising the steps of uniformly charging an electrothermographic recording layer which exhibits chargeability A at room temperature and chargeability B above room temperature, where the chargeabilities A and B are in the relationship of A>B.gtoreq.0, forming a latent electrostatic image by applying digital thermal signals which correspond to an original image, developing the latent electrostatic image with a toner of which polarity is the same as or opposite to the polarity of the electric charge of the latent electrostatic image to form a toner image, transferring the toner image to a receiving medium, and fixing the toner image transferred on the receiving medium; and a recording medium for use with the transfer-type electrothermographic recording method, comprising the above electrothermographic recording layer. ## Claims ### Claim 1 A transfer-type electrothermographic recording method comprising the steps of: uniformly charging an electrothermographic recording layer of a recording medium, which exhibits chargeability A at room temperature and chargeability B above room temperature, where the chargeability A and B are in a relationship of A>B.gtoreq.0; forming a latent electrostatic image by applying digital thermal signals which correspond to an original image by a thermal head under an application of a bias voltage; developing said latent electrostatic image with a toner of which polarity is the same as or opposite to the polarity of said latent electrostatic image to form a toner image; transferring said toner image to a receiving medium; and fixing said toner image transferred on said receiving medium. ### Claim 2 (depends on 1) The transfer-type electrothermographic recording method as claimed in claim 1, wherein said electrothermographic recording layer comprises a material selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, cellulose acetate, polyvinyl alcohol, polyacetal, polycarbonate, a vinyl chloride - vinyl acetate copolymer, an ethylene vinyl acetate copolymer, an acrylic polymer, a styrene-based polymer, polyester, polyamide, polyimide, polyethylene, polypropylene, a polypropylene - based polymer, a perfluoroalkyl acrylate, a fluorinated-acryl - acryl copolymer, a silicone resin, a silicone rubber, a silicone wax, a silicone oil, and a styrene - acryl copolymer. ### Claim 3 (depends on 1) The transfer-type electrothermographic recording method as claimed in claim 1, wherein said digital thermal signals are applied by a thermal head which can yield a latent electrostatic image without reducing the electric potential of the background thereof even when brought into contact with the background. ### Claim 4 (depends on 1) The transfer-type electrothermographic recording method as claimed in claim 1, wherein said latent electrostatic image is developed with a toner with the same polarity as that of said latent electrostatic image. ### Claim 5 (depends on 1) The transfer-type electrothermographic recording method as claimed in claim 1, wherein said latent electrostatic image is developed with a toner with the opposite polarity to that of said latent electrostatic image. ### Claim 6 (depends on 1) The transfer-type electrothermographic recording method as claimed in claim 1, wherein said recording medium consists essentially of said electrothermographic recording layer comprising a thermoplastic resin and a lubricant selected from the group consisting of silica, calcium carbonate, graphite, molybdenum disulfide, tungsten disulfide, talc, alumina, kaolin, titanium dioxide, barium sulfate, zeolite, polystyrene, polymethylmethacrylate, polytetrafluoroethylene, polyvinylidene fluoride, polyacrylonitrile, a benzoguanamine resin, a silicone resin, carboxymethyl cellulose, starch, oleic amide, stearic amide, behenic amide, erucinic amide, elaidic amide, natural waxes, synthetic waxes and phosphoric esters incorporated into said recording layer. ### Claim 7 (depends on 6) The transfer-type electrothermographic recording method as claimed in claim 6, wherein said electrothermographic recording layer has a surface with a critical surface tension (.gamma.c) of 35 dynes/cm or less. ### Claim 8 (depends on 6) The transfer-type electrothermographic recording method as claimed in claim 6, wherein said electrothermographic recording layer comprises a material selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, cellulose acetate, polyvinyl alcohol, polyacetal, polycarbonate, a vinyl chloride - vinyl acetate copolymer, an ethylene - vinyl acetate copolymer, an acrylic polymer, a styrene-based polymer, polyester, polyamide, polyimide, polyethylene, polypropylene, a polypropylene-based polymer, perfluoroalkyl acrylate, a fluorinated-acryl - acryl copolymer, a silicone resin, a silicone rubber, a silicone wax, a silicone oil, and a styrene - acryl copolymer. ### Claim 9 (depends on 6) The transfer-type electrothermographic recording method as claimed in claim 6, wherein said electrothermographic recording layer has a thickness in the range of 5 .mu.m to 100 .mu.m. ### Claim 10 (depends on 6) The transfer-type electrothermographic recording method as claimed in claim 6, wherein said recording medium further consists essentially of at least one of a base layer and an electroconductive layer, on which said electrothermographic recording layer is supported. ### Claim 11 (depends on 1) The transfer-type electrothermographic recording methods claimed in claim 1 wherein said recording medium consists essentially of said electrothermographic recording layer and a lubricating layer which layer comprises a lubricant selected from the group consisting of silica, calcium carbonate, graphite, molybdenum disulfide, tungsten disulfide, talc, alumina, kaolin, titanium dioxide, barium sulfate, zeolite, polystyrene, polymethylmethacrylate, polytetrafluoroethylene, polyvinylidene fluoride, polyacrylonitrile, a benzoguanamine resin, a silicone resin, carbonxymethyl cellulose, starch, oleic amide, stearic amide, behenic amide, erucinic amide, elaidic amide, natural waxes, synthetic waxes, phosphoric esters, fluorinated-acryl - acryl copolymer, perfluoroalkyl acrylate, a silicone polymer and polyethylene on said electrothermographic recording layer. ### Claim 12 (depends on 11) The transfer-type electrothermographic recording method as claimed in claim 11, wherein said lubricating layer comprises a polymer or a material having a critical surface tension (.gamma.c) of 35 dynes/cm or less. ### Claim 13 (depends on 17) The transfer-type electrothermographic recording method as claimed in claim 17, wherein said polymer is selected from the group consisting of a fluorinated-acryl - acryl copolymer, perfluoroalkyl acrylate, a silicone polymer and polyethylene. ### Claim 14 (depends on 12) The transfer-type electrothermographic recording method a claimed in claim 12, wherein said material is selected from the group consisting of stearic amide, behenic amide and a polyethylene wax. ### Claim 15 (depends on 11) The transfer-type electrothermographic recording method as claimed in claim 11, wherein said recording medium further consists essentially of at least one of a base layer and an electroconductive layer, on which said electrothermographic recording layer is supported. ### Claim 16 (depends on 15) The transfer-type electrothermographic recording method as claimed in claim 15, wherein said lubricating layer comprises a polymer cr a material having a critical surface tension (.gamma.c) of 35 dyne/cm or less. ### Claim 17 (depends on 16) The transfer-type electrothermographic recording method as claimed in claim 16, wherein said polymer is selected from the group consisting of a fluorinated-acryl - acryl copolymer, perfluoroalkyl acrylate, a silicone polymer and polyethylene. ### Claim 18 (depends on 16) The transfer-type electrothermographic recording method as claimed in claim 16, wherein said material is selected from the group consisting of stearic amide, behenic amide and a polyethylene wax.