# US 7,608,376 B2 · Method of manufacturing liquid developer, liquid developer, and image forming apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,376 B2 - Document ID: US7608376B2 - Status: Granted - Kind: B2 - Application number: 11/677,964 - Filed: 2007-02-22 - Published: 2007-08-30 - Granted: 2009-10-27 - Earliest claimed: 2006-02-24 - Assignees: Seiko Epson Corporation - Inventors: Satoru Miura; Hiroshi Kaiho; Takashi Teshima; Koji Akioka; Ken Ikuma - Web page: https://patentgrep.com/patent/US7608376B2 ## CPC - G03G 9/125: characterised by the liquid - G03G 9/12: in liquid developer mixtures - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A method of manufacturing a liquid developer includes associating fine particles mainly containing a resin material so as to obtain associated particles, and disintegrating the associated particles in an insulation liquid so as to obtain toner particles. ## Claims ### Claim 1 A method of manufacturing a liquid developer, the method comprising: forming a water-based emulsion by dispersing a dispersoid mainly containing a resin material in a water-based liquid; forming associated particles having an average particle size of 1˜10 μm by adding an electrolyte to the water-based emulsion and associating the dispersoid having an average particle size of 0.01˜3 μm in the water-based emulsion; obtaining the associated particles by drying the dispersoid; mixing the associated particles with a first insulation liquid; disintegrating the associated particles in the first insulation liquid so as to obtain toner particles having an average particle size of 1˜5 μm; and adding a second insulation liquid that is different from the first insulation liquid. ### Claim 2 (depends on 1) The method according to claim 1, wherein, when electrical resistance of the liquid developer is A [Ωcm] and electrical resistance of the insulation liquid is B [Ωcm], the relationship 0.04≦A/B≦0.3 is satisfied. ### Claim 3 (depends on 2) The method according to claim 2, wherein, the content of the dispersant in the liquid developer is 0.10 to 3.0 wt %. ### Claim 4 (depends on 3) The method according to claim 3, wherein the dispersant is a polymer dispersant. ### Claim 5 (depends on 3) The method according to claim 3, wherein, when the content of the dispersant in the liquid developer is C [wt %] and the content of toner particles is D [wt %], the relationship 0.006≦C/D≦0.12 is satisfied. ### Claim 6 (depends on 1) The method according to claim 1, wherein the first insulation liquid used for disintegration contains fatty acid monoester. ### Claim 7 (depends on 1) The method according to claim 1, wherein the first insulation liquid used for disintegration contains fatty acid ester, wherein said fatty acid ester has 8 to 10 carbon atoms. ### Claim 8 (depends on 7) The method according to claim 7, wherein the first insulation liquid is ester of medium-chain fatty acid and glycerine. ### Claim 9 (depends on 1) The method according to claim 1, wherein the insulation liquid used for disintegration contains paraffin oil, wherein said paraffin oil has a viscosity of 10.0 mPa·s or less. ### Claim 10 (depends on 1) The method according to claim 1, wherein viscosity of the insulation liquid used for disintegration is 1000 mPa s or less. ### Claim 11 (depends on 1) The method according to claim 1, wherein interfacial tension of the insulation liquid used for disintegration with respect to the resin material is 35 mN/m or less. ### Claim 12 (depends on 1) The method according to claim 1, wherein the resin material is polyester resin. ### Claim 13 A liquid developer that is manufactured by a manufacturing method including: forming a water-based emulsion by dispersing a dispersoid mainly containing a resin material in a water-based liquid; forming associated particles having an average particle size of 1˜10 μm by adding an electrolyte to the water-based emulsion and associating the dispersoid having an average particle size of 0.01˜3 μm in the water-based emulsion; obtaining the associated particles by drying the dispersoid; mixing the associated particles with a first insulation liquid; disintegrating the associated particles in the first insulation liquid so as to obtain toner particles having an average particle size of 1˜10 μm; and adding a second insulation liquid that is different from the first insulation liquid. ### Claim 14 An image forming apparatus comprising: a liquid developer storage unit that stores a liquid developer; a developing unit that develops using the liquid developer supplied from the liquid developer storage unit; a transfer unit that transfers an image formed on the developing unit to a recording medium so as to form a transfer image on the recording medium; and a fixing unit that fixes the transfer image formed on the recording medium onto the recording medium, wherein the liquid developer is manufactured by a manufacturing method that includes: forming a water-based emulsion by dispersing a dispersoid mainly containing a resin material in a water-based liquid; forming associated particles having an average particle size of 1˜10 μm by adding an electrolyte to the water-based emulsion and associating the dispersoid having an average particle size of 0.01˜3 μm in the water-based emulsion; obtaining the associated particles by drying the dispersoid; mixing the associated particles with a first insulation liquid; disintegrating the associated particles in the first insulation liquid so as to obtain toner particles having an average particle size of 1˜10 μmμm; and adding a second insulation liquid that is different from the first insulation liquid.