# US 5,710,965 A · Developer for developing electrostatic images and 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 5,710,965 A - Document ID: US5710965A - Status: Granted - Kind: A - Application number: 08/515,327 - Filed: 1995-08-15 - Granted: 1998-01-20 - Earliest claimed: 1995-08-15 - Assignees: Canon Kabushiki Kaisha - Inventors: Keita Nozawa; Tsutomu Kukimoto; Satoshi Matsunaga; Kazuyoshi Hagiwara - Web page: https://patentgrep.com/patent/US5710965A ## CPC - G03G 15/16: of a toner pattern, e.g. a powder pattern {, e.g. magnetic transfer} - G03G 9/09708: {Inorganic compounds} - G03G 9/09716: {treated with organic compounds} - G03G 13/09: using magnetic brush - G03G 13/16: of a toner pattern, e.g. a powder pattern - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A developer for developing electrostatic images has a toner and an aggregate of fine particles. The aggregate holds a silicone compound selected from the group consisting of a silicone oil and a silicone varnish, in an amount of from 20% by weight to 90% by weight. ## Claims ### Claim 1 An image forming method comprising: electrostatically charging a latent image bearing member; forming an electrostatic image on the latent image bearing member thus charged; developing the electrostatic image by the use of a developer to form a toner image on the latent image bearing member; and transferring the toner image formed on the latent image bearing member, to a transfer medium through a contact transfer means to which a bias voltage is applied; wherein said developer comprises 100 parts by weight of a toner and 0.01 part by weight to 10 parts by weight of an aggregate of fine particles, said aggregate holds a silicone compound selected from the group consisting of a silicone oil and a silicone varnish, in an amount of from 20% by weight to 90% by weight, and has a dissolving matter in a quantity not less than 10% by weight as measured by Soxhlet extraction using chloroform. ### Claim 2 (depends on 1) The method according to claim 1, wherein said contact transfer means has a transfer roller. ### Claim 3 (depends on 2) The method according to claim 2, wherein said transfer roller is brought into pressure contact with the latent image bearing member at a contact pressure of from 1 g/cm to 300 g/cm. ### Claim 4 (depends on 3) The method according to claim 3, wherein said transfer roller is brought into pressure contact with the latent image bearing member at a contact pressure of from 3 g/cm to 100 g/cm. ### Claim 5 (depends on 1) The method according to claim 1, wherein said contact transfer means has a transfer belt. ### Claim 6 (depends on 1) The method according to claim 1, wherein a DC voltage of from +0.2 kV to +10 kV is applied to said contact transfer means. ### Claim 7 (depends on 1) The method according to claim 1, wherein a DC voltage of from -0.2 kV to -10 kV is applied to said contact transfer means. ### Claim 8 (depends on 1) The method according to claim 1, wherein said aggregate has a BET specific surface area of from 0.01 m.sup.2 /g to 50 m.sup.2 /g. ### Claim 9 (depends on 8) The method according to claim 8, wherein said aggregate holds the silicone compound in an amount of from 27% by weight to 85% by weight. ### Claim 10 (depends on 1) The method according to claim 1, wherein said aggregate has a BET specific surface area of from 0.05 m.sup.2 /g to 30 m.sup.2 /g. ### Claim 11 (depends on 1) The method according to claim 1, wherein said aggregate has a BET specific surface area of from 0.05 m.sup.2 /g to 30 m.sup.2 /g and is contained in an amount of from 0.01 part by weight to 10 parts by weight based on 100 parts by weight of the toner, and a fine silica powder having a BET specific surface area of from 50 m.sup.2 /g to 400 m.sup.2 /g is further contained in an amount of from 0.01 part by weight to 8 parts by weight based on 100 parts by weight of the toner. ### Claim 12 (depends on 1) The method according to claim 1, wherein said aggregate has a BET specific surface area of from 0.05 m.sup.2 /g to 30 m.sup.2 /g and is contained in an amount of from 0.01 part by weight to 10 parts by weight based on 100 parts by weight of the toner, and a fine titanium oxide powder is further contained in an amount of from 0.01 part by weight to 8 parts by weight based on 100 parts by weight of the toner. ### Claim 13 (depends on 1) The method according to claim 1, wherein said fine particles are formed of an inorganic compound. ### Claim 14 (depends on 13) The method according to claim 13, wherein said inorganic compound is a metal oxide. ### Claim 15 (depends on 14) The method according to claim 14, wherein said metal oxide is silicon oxide. ### Claim 16 (depends on 14) The method according to claim 14, wherein said metal oxide is aluminum oxide. ### Claim 17 (depends on 14) The method according to claim 14, wherein said metal oxide is titanium oxide. ### Claim 18 (depends on 14) The method according to claim 14, wherein said metal oxide is a double oxide formed of silicon and aluminum. ### Claim 19 (depends on 14) The method according to claim 14, wherein said metal oxide is a double oxide formed of silicon and titanium. ### Claim 20 (depends on 14) The method according to claim 14, wherein said metal oxide is a double oxide formed of aluminum and titanium. ### Claim 21 (depends on 1) The method according to claim 1, wherein said fine particles are formed of a resin. ### Claim 22 (depends on 1) The method according to claim 1, wherein said silicone oil has a viscosity at 25.degree. C. of from 50 centistokes to 200,000 centistokes. ### Claim 23 (depends on 22) The method according to claim 22, wherein said silicone oil has a viscosity at 25.degree. C. of from 500 centistokes to 150,000 centistokes. ### Claim 24 (depends on 23) The method according to claim 23, wherein said silicone oil has a viscosity at 25.degree. C. of from 3,000 centistokes to 80,000 centistokes. ### Claim 25 (depends on 20) The method according to claim 20, wherein said silicone varnish has a viscosity at 25.degree. C. of from 50 centistokes to 200,000 centistokes. ### Claim 26 (depends on 1) The method according to claim 1, wherein said silicone varnish has a viscosity at 25.degree. C. of from 3,000 centistokes to 80,000 centistokes. ### Claim 27 (depends on 1) The method according to claim 1, wherein said toner has a weight average particle diameter of from 3 .mu.m to 15 .mu.m. ### Claim 28 (depends on 27) The method according to claim 27, wherein said toner has a weight average particle diameter of from 4 .mu.m to 9 .mu.m. ### Claim 29 (depends on 1) The method according to claim 1, wherein said aggregate is contained in an amount of from 0.03 part by weight to 5 parts by weight based on 100 parts by weight of the toner. ### Claim 30 (depends on 1) The method according to claim 1, wherein said aggregate is contained in an amount of from 0.05 part by weight to 2 parts by weight based on 100 parts by weight of the toner. ### Claim 31 (depends on 1) The method according to claim 1, wherein said silicone oil has a viscosity at 25.degree. C. of from 3500 to 12000 centistokes. ### Claim 32 (depends on 1) The method according to claim 1, wherein said aggregate has a dissolving matter in a quantity of 27% by weight to 76% by weight as measured by Soxhlet extraction using chloroform. ### Claim 33 (depends on 1) The method according to claim 1, wherein said aggregate holds the silicone oil in an amount of from 30% by weight to 80% by weight. ### Claim 34 (depends on 1) The method according to claim 1, wherein said aggregate is contained in an amount of from 0.05 part by weight to 2 parts by weight based on 100 parts by weight of the toner, holds the silicone oil in an amount of from 30% by weight to 80% by weight, and has a dissolving matter in a quantity of 27% by weight to 76% by weight as measured by Soxhlet extraction using chloroform. ### Claim 35 (depends on 34) The method according to claim 34, wherein said aggregate has a BET specific surface area of from 0.05 m.sup.2 /g to 30 m.sup.2 /g and said silicone oil has a viscosity at 25.degree. C. of from 3000 to 80000 centistokes. ### Claim 36 A developer for developing electrostatic images, comprising 100 parts by weight of a toner and 0.01 part by weight to 10 parts by weight of an aggregate of fine particles, said aggregate holds a silicone compound selected from the group consisting of a silicone oil and a silicone varnish, in an amount of from 20% by weight to 90% by weight, and has a dissolving matter in a quantity not less than 10% by weight as measured by Soxhlet extraction using chloroform. ### Claim 37 (depends on 36) The developer according to claim 36, wherein said aggregate has a BET specific surface area of from 0.01 m.sup.2 /g to 50 m.sup.2 /g. ### Claim 38 (depends on 37) The developer according to claim 37, wherein said aggregate holds the silicone compound in an amount of from 27% by weight to 85% by weight. ### Claim 39 (depends on 36) The developer according to claim 36, wherein said aggregate has a BET specific surface area of from 0.05 m.sup.2 /g to 30 m.sup.2 /g. ### Claim 40 (depends on 36) The developer according to claim 36, wherein said aggregate has a BET specific surface area of from 0.05 m.sup.2 /g to 30 m.sup.2 /g and is contained in an amount of from 0.01 part by weight to 10 parts by weight based on 100 parts by weight of the toner, and a fine silica powder having a BET specific surface area of from 50 m.sup.2 /g to 400 m.sup.2 /g is further contained in an amount of from 0.01 part by weight to 8 parts by weight based on 100 parts by weight of the toner. ### Claim 41 (depends on 36) The developer according to claim 36, wherein said aggregate has a BET specific surface area of from 0.05 m.sup.2 /g to 30 m.sup.2 /g and is contained in an amount of from 0.01 part by weight to 10 parts by weight based on 100 parts by weight of the toner, and a fine titanium oxide powder is further contained in an amount of from 0.01 part by weight to 8 parts by weight based on 100 parts by weight of the toner. ### Claim 42 (depends on 36) The developer according to claim 36, wherein said fine particles are formed of an inorganic compound. ### Claim 43 (depends on 42) The developer according to claim 42, wherein said inorganic compound is a metal oxide. ### Claim 44 (depends on 43) The developer according to claim 43, wherein said metal oxide is silicon oxide. ### Claim 45 (depends on 43) The developer according to claim 43, wherein said metal oxide is aluminum oxide. ### Claim 46 (depends on 43) The developer according to claim 43, wherein said metal oxide is titanium oxide. ### Claim 47 (depends on 43) The developer according to claim 43, wherein said metal oxide is a composite oxide formed of silicon and aluminum. ### Claim 48 (depends on 43) The developer according to claim 43, wherein said metal oxide is a double oxide formed of silicon and titanium. ### Claim 49 (depends on 43) The developer according to claim 43, wherein said metal oxide is a double oxide formed of aluminum and titanium. ### Claim 50 (depends on 36) The developer according to claim 36, wherein said fine particles are formed of a resin. ### Claim 51 (depends on 36) The developer according to claim 36, wherein said silicone oil has a viscosity at 25.degree. C. of from 50 centistokes to 200,000 centistokes. ### Claim 52 (depends on 51) The developer according to claim 51, wherein said silicone oil has a viscosity at 25.degree. C. of from 500 centistokes to 150,000 centistokes. ### Claim 53 (depends on 52) The developer according to claim 52, wherein said silicone oil has a viscosity at 25.degree. C. of from 3,000 centistokes to 80,000 centistokes. ### Claim 54 (depends on 36) The developer according to claim 36, wherein said silicone varnish has a viscosity at 25.degree. C. of from 50 centistokes to 200,000 centistokes. ### Claim 55 (depends on 36) The developer according to claim 36, wherein said silicone varnish has a viscosity at 25.degree. C. of from 3,000 centistokes to 80,000 centistokes. ### Claim 56 (depends on 36) The developer according to claim 36, wherein said toner has a weight average particle diameter of from 3 .mu.m to 15 .mu.m. ### Claim 57 (depends on 56) The developer according to claim 56, wherein said toner has a weight average particle diameter of from 4 .mu.m to 9 .mu.m. ### Claim 58 (depends on 36) The developer according to claim 36, wherein said aggregate is contained in an amount of from 0.03 part by weight to 5 parts by weight based on 100 parts by weight of the toner. ### Claim 59 (depends on 36) The developer according to claim 36, wherein said aggregate is contained in an amount of from 0.05 part by weight to 2 parts by weight based on 100 parts by weight of the toner. ### Claim 60 (depends on 36) The developer according to claim 36, wherein said silicone oil has a viscosity at 25.degree. C. of from 3500 to 12000 centistokes. ### Claim 61 (depends on 36) The developer according to claim 36, wherein said aggregate has a dissolving matter in a quantity of 27% by weight to 76% by weight as measured by Soxhlet extraction using chloroform. ### Claim 62 (depends on 36) The developer according to claim 36, wherein said aggregate holds the silicone oil in an amount of from 30% by weight to 80% by weight. ### Claim 63 (depends on 36) The developer according to claim 36, wherein said aggregate is contained in an amount of from 0.05 part by weight to 2 parts by weight based on 100 parts by weight of the toner, holds the silicone oil in an amount of from 30% by weight to 80% by weight, and has a dissolving matter in a quantity of 27% by weight to 76% by weight as measured by Soxhlet extraction using chloroform. ### Claim 64 (depends on 63) The developer according to claim 63, wherein said aggregate has a BET specific surface area of from 0.05 m.sup.2 /g to 30 m.sup.2 /g and said silicone oil has a viscosity at 25.degree. C. of from 3000 to 80000 centistokes.