# US 2012/0237253 A1 · Electrostatic image developing toner, toner container and process cartridge > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2012/0237253 A1 - Document ID: US20120237253A1 - Status: Published application - Kind: A1 - Application number: 13/417,741 - Filed: 2012-03-12 - Published: 2012-09-20 - Earliest claimed: 2011-03-17 - Assignees: Ricoh Company, Ltd. - Inventors: Tomohiro FUKAO; Takuya Kadota; Yoshihiro Mikuriya; Tsuyoshi Nozaki; Yoshimichi Ishikawa; Kazuoki Fuwa; Tomoharu Miki - Web page: https://patentgrep.com/patent/US20120237253A1 ## CPC - G03G 21/18: using a processing cartridge {, whereby the process cartridge comprises at least two image processing means in a single unit} - G03G 9/0935: {specified by the core material} - G03G 9/09371: {obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds} - G03G 9/09392: {Preparation thereof} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An electrostatic image developing toner including: toner particles; wherein the toner particles each contain: a core particle including a first resin and a colorant; and fine resin particles each formed of a second resin and existing in a surface of the core particle, wherein part of each fine resin particle is embedded in the core particle to form an embedded region, and the remaining part of the fine resin particle is exposed on the surface of the core particle to form an exposed region, and wherein each toner particle satisfies an expression of R1>R1′ where, in a cross-section of the toner particle, R1′ denotes an average diameter of openings of the first resin in which the second resin is embedded and R1 denotes an average diameter of the exposed regions. ## Claims ### Claim 1 An electrostatic image developing toner comprising: toner particles; wherein the toner particles each contain: a core particle comprising a first resin and a colorant; and fine resin particles each formed of a second resin and existing in a surface of the core particle, wherein part of each fine resin particle is embedded in the core particle to form an embedded region, and the remaining part of the fine resin particle is exposed on the surface of the core particle to form an exposed region, and wherein each toner particle satisfies an expression of R1>R1′ where, in a cross-section of the toner particle, R1′ denotes an average diameter of openings of the first resin in which the second resin is embedded and R1 denotes an average diameter of the exposed regions. ### Claim 2 (depends on 1) The electrostatic image developing toner according to claim 1, wherein each toner particle satisfies an expression of D2/D1≧1 where, in the cross-section of the toner particle, D1 denotes an average height of the exposed regions of the second resin and D2 denotes an average depth of the embedded regions of the second resin. ### Claim 3 (depends on 1) The electrostatic image developing toner according to claim 1, wherein each toner particle satisfies an expression of 3≦R1/D1 where D1 denotes an average height of the exposed regions of the second resin in the cross-section of the toner particle. ### Claim 4 (depends on 1) The electrostatic image developing toner according to claim 1, wherein a coverage rate of the exposed regions on the surface of the core particle is 30% to 100%. ### Claim 5 (depends on 1) The electrostatic image developing toner according to claim 1, wherein a standard deviation of coverage rates of the exposed regions on the surface of the core particle is 10 or less. ### Claim 6 (depends on 1) The electrostatic image developing toner according to claim 1, wherein a rate of a mass of the fine resin particles relative to a total mass of the core particle and the fine resin particles is 1% to 20%. ### Claim 7 (depends on 1) The electrostatic image developing toner according to claim 1, wherein the electrostatic image developing toner is obtained through a process including producing the core particles, and attaching and fusing the fine resin particles on the surfaces of the core particles. ### Claim 8 (depends on 1) The electrostatic image developing toner according to claim 1, wherein the first resin is a polyester resin. ### Claim 9 (depends on 1) The electrostatic image developing toner according to claim 1, wherein the second resin is a vinyl resin. ### Claim 10 (depends on 1) The electrostatic image developing toner according to claim 1, wherein an amount of a styrene monomer among monomers forming the second resin is 80% by mass to 100% by mass. ### Claim 11 (depends on 1) The electrostatic image developing toner according to claim 1, wherein an amount of an acid monomer-derived site among monomer-derived sites forming the second resin is 0% by mass. ### Claim 12 (depends on 1) The electrostatic image developing toner according to claim 1, wherein the core particles each further contain a modified polyester resin containing at least one of a urethane group and a urea group. ### Claim 13 (depends on 1) The electrostatic image developing toner according to claim 1, wherein the core particles each further contain a releasing agent. ### Claim 14 (depends on 1) The electrostatic image developing toner according to claim 1, wherein the electrostatic image developing toner further contains as an additive fine silica particles whose surfaces have been hydrophobized. ### Claim 15 (depends on 1) A toner container comprising: the electrostatic image developing toner according to claim 1, and a container, which houses the electrostatic image developing toner. ### Claim 16 A process cartridge comprising: a latent image bearing member, a developing device configured to develop, with a developer, a latent image on the latent image bearing member, the latent image bearing member and the developing unit being integrally supported in the process cartridge which is mounted detachably to an image forming apparatus, wherein the developer contains an electrostatic image developing toner comprising: toner particles; wherein the toner particles each contain: a core particle comprising a first resin and a colorant; and fine resin particles each formed of a second resin and existing in a surface of the core particle, wherein part of each fine resin particle is embedded in the core particle to form an embedded region, and the remaining part of the fine resin particle is exposed on the surface of the core particle to form an exposed region, and wherein each toner particle satisfies an expression of R1>R1′ where, in a cross-section of the toner particle, R1′ denotes an average diameter of openings of the first resin in which the second resin is embedded and R1 denotes an average diameter of the exposed regions.