# US 8,771,915 B2 · Image forming method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,915 B2 - Document ID: US8771915B2 - Status: Granted - Kind: B2 - Application number: 13/082,044 - Filed: 2011-04-07 - Published: 2011-10-20 - Granted: 2014-07-08 - Earliest claimed: 2010-04-16 - Assignees: Konica Minolta Business Technologies, Inc. - Applicants: Noboru Ueda; Hiroshi Nagasawa; Anju Hori - Inventors: Noboru Ueda; Hiroshi Nagasawa; Anju Hori - Web page: https://patentgrep.com/patent/US8771915B2 ## CPC - G03G 15/2064: {combined with pressure} - G03G 9/0819: {characterised by the dimensions of the particles} - G03G 9/08795: {characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants} - G03G 9/08797: {characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature} - G03G 2215/2009: Pressure belt - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An image forming method is disclosed, comprising transferring and fixing steps, wherein fixing is performed by a fixing device in which at least one of a heating member and a pressing member comprises an endless belt entrained about plural rollers, and the heating member and the pressing member are pressed against each other to form a fixing nip, and wherein toner particles contains a binder resin which has a domain/matrix structure constituted of a high-elastic resin forming a domain and a low-elastic resin forming a matrix in an elastic image obtained when observing the toner particles by an atomic force microscope with respect to a section of the individual toner particles, in which an arithmetic average value of a ratio (L/W) of a major axis (L) to a minor axis (W) of individual domains is 1.5 to 5.0, and domains having the major axis (L) of 60 to 500 nm account for not less than 80% by number of total domains and domains having the minor axis (W) of 45 to 100 nm account for not less than 80% by number of total domains. ## Claims ### Claim 1 An image forming method comprising the steps of: (a) transferring a toner image formed on an image support onto a transfer material, and (b) fixing the toner image transferred onto the transfer material, wherein in step (b), fixing is performed by a fixing device in which at least one of a heating member and a pressing member comprises an endless belt entrained about plural rollers, and the heating member and the pressing member are pressed against each other to form a fixing nip, and wherein a toner forming the toner image comprises toner particles containing a binder resin and the binder resin has a domain/matrix structure constituted of a high-elastic resin forming a domain and a low-elastic resin forming a matrix in an elastic image obtained when observing the toner particles by an atomic force microscope with respect to a section of the individual toner particles, in which an arithmetic average value of a ratio (L/W) of a major axis (L) to minor axis (W) of individual domains is in a range of 1.5 to 5.0, and domains having the major axis (L) falling within a range of from 60 to 500 nm account for not less than 80% by number of total domains and domains having the minor axis (W) falling within a range of from 45 to 100 nm account for not less than 80% by number of total domains, and wherein the high-elastic resin forming a domain exhibits a storage modulus of 4.0×105 to 1.0×108 dyn/cm2 at 100° C. and the low-elastic resin forming a matrix exhibits a storage modulus of 1.0×102 to 1.0×108 dyn/cm2 at 100° C. ### Claim 2 (depends on 1) The method of claim 1, wherein the heating member comprises a rotary roller and the pressing member comprises an endless belt entrained about plural rollers, and a pressure-applying member which presses against the heating member through the endless belt is provided on an inner circumference surface of the endless belt. ### Claim 3 (depends on 1) The method of claim 1, wherein a nip length of the fixing nip is 20 to 50 mm, a surface temperature of the heating member is from 150 to 170° C., a surface temperature of the pressing member is from 90 to 110° C., and a difference between the surface temperature of the heating member and the surface temperature of the pressing member being from 40 to 70° C. ### Claim 4 (depends on 1) The method of claim 1, wherein the endless belt is constituted of a substrate formed of a heat-resistant resin, an elastic layer covering the surface of the substrate and formed of an elastic resin, and a releasing layer covering the elastic layer and formed of a fluororesin. ### Claim 5 (depends on 1) The method of claim 1, wherein the fixing device is provided with a fan and a cooler constituted of a fan and a duct for introducing air supplied by the fan in the prescribed direction. ### Claim 6 (depends on 1) The method of claim 1, wherein the toner exhibits a softening point of 90 to 110° C. ### Claim 7 (depends on 1) The method of claim 1, wherein the toner exhibits a softening point of 95 to 105° C. ### Claim 8 (depends on 1) The method of claim 1, wherein, in an elastic image obtained when observing the toner particles by an atomic force microscope with respect to a section of the individual toner particles, an arithmetic average value of areas of individual domains is in a range of 0.01 to 0.05 μm2.