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AssigneeCanon Kabushiki Kaisha
InventorsTakashige Kasuya, Osamu Tamura, Hiroshi Yusa, Takakuni Kobori, Masaichiro Katada
Estimating the term…
A developer for developing an electrostatic image has a toner which contains a particulate toner, a particulate silica A and a particulate silica B. The toner has a weight-average particle size of not larger than 12.0 .mu.m and a particle-number distribution showing not more than 50% of toner particles not larger than 4.0 .mu.m in particle size and not more than 10% of toner particles not smaller than 10.08 .mu.m in particle size, each of the toner particles having a toner composition containing at least a polymer component and a charge controlling agent. The particulate silica A is composed of silicone oil-treated silica particles and has an average particle size of not larger than 0.1 .mu.m, while the particulate silica B is composed of silicone oil-treated silica particles and has an average particle size of 0.5 to 50 .mu.m. The particulate silica B also has a particle-number distribution showing not more than 50% of silica particles not larger than 1.0 .mu.m in particle size and not more than 10% of silica particles not smaller than 100 .mu.m in particle size. Also disclosed is an image forming method which uses this developer.
A developer for developing an electrostatic image which comprises a toner comprising a particulate toner, a particulate silica A and a particulate silica B, the toner having a weight-average particle size of not larger than 12.0 .mu.m and a particle-number distribution showing not more than 50% of toner particles not larger than 4.0 .mu.m in particle size and not more than 10% of toner particles not smaller than 10.08 .mu.m in particle size, each of the toner particles being formed of a toner composition comprising at least a polymer component and a charge controlling agent, the particulate silica A being composed of silicone oil-treated silica particles and having an average particle size of not larger than 0.1 .mu.m, the particulate silica B being composed of silicone oil-treated silica particles and having an average particle size of 0.5 to 50 .mu.m and a particle-number distribution showing not more than 50% of silica particles not larger than 1.0 .mu.m in particle size and not more than 10% of silica particles not smaller than 100 .mu.m in particle size, the particulate silica A and particulate silica B meeting the following requirements,
An image forming method comprising electrifying an electrostatic image carrying member, exposing the electrified carrying member to light so as to form an elecrostatic image thereon, developing the resulting image with use of a developer so as to form a toner image, transferring the toner image to a transfer material optionally through an intermediate transfer material, and subsequently fixing the image on the transfer material by application of heat and pressure, wherein the developer comprises a toner comprising a particulate toner, a particulate silica A and a particulate silica B, the toner having a weight-average particle size of not larger than 12.0 .mu.m and a particle-number distribution showing not more than 50% of toner particles not larger than 4.0 .mu.m in particle size and not more than 10% of toner particles not smaller than 10.08 .mu.m in particle size, each of the toner particles being formed of a toner composition comprising at least a polymer component and a charge controlling agent, the particulate silica A being composed of silicone oil-treated silica particles and having an average particle size of smaller not larger 0.1 .mu.m, the particulate silica B being composed of silicone oil-treated silica particles and having an average particle size of 0.5 to 50 .mu.m and a particle-number distribution showing not more than 50% of silica particles not larger than 1.0 .mu.m in particle size and not more than 10% of silica particles not smaller than 100 .mu.m in particle size, the particulate silica A and particulate silica B meeting the following requirements,
Dependencies are inferred from the claim text.