Abstract: An image forming apparatus includes a member to be charged for carrying an electrostatic latent image; a contact charging means for contact charging the member to be charged and a developing means for developing the latent image. The developing means includes a developer having a magnetic toner and fine powder treated with a silicone oil or varnish-treating agent, wherein the magnetic toner particles include a binder resin and contain from 10-70 wt. % of magnetic fine powder. An image forming method includes the steps of contact charging, latent image forming and developing with a developer having the binder resin, 10 to 70 wt. % magnetic fine powder and fine powder treated with a silicone oil or varnish-treating agent.

Abstract: An image forming apparatus includes a member to be charged for carrying an electrostatic image, a contact-charging means for charging the member to be charged in contact with the member to be charged, and a developing means for developing the electrostatic image carried on the member to be charged. The developing means includes a developer for developing the electrostatic image comprising a toner and hydrophobic inorganic fine powder. The hydrophobic fine powder has a hydrophobicity of 60% or higher and the toner has a volume average particle size of 4-8 microns. The hydrophobic inorganic fine powder not only improves the fluidity of the developer and adjusts the chargeability of the developer but also prevents difficulties due to interaction between the member to be charged and the contact charging means in the presence of residual developer, such as damages of the member to be charged and toner-sticking onto the member to be charged.

Abstract: An image forming method, including the steps of: developing an electrostatic image formed on an electrostatic image-bearing member with a developer to form thereon thereon a developed image, the developer containing 100 wt. parts of a toner and 0.05 to 3 wt. parts of fine powder treated with a silicone oil or silicone varnish; and transferring the developed image on the electrostatic image-bearing member to a transfer material while causing a transfer device, such as a roller or belt to contact the electrostatic image-bearing member by the medium of the transfer material under a line pressure of 3 g/cm or higher.

Abstract: An image forming apparatus is constituted by an image-bearing member for bearing a latent image, and a developing apparatus for developing the latent image. The developing apparatus is constituted by a developer container for containing a developer, a developer-carrying member for carrying and conveying the developer contained in the developer container to a developing zone opposite the image-bearing member, and an elastic blade for regulating the developer carried and conveyed on the developer-carrying member to a prescribed thickness to form a thin developer layer on the developer-carrying member. A developer suitable for use in the above developing apparatus is given by a toner, which comprises a binder resin composition which contains 10-70 wt. % of a THF (tetrahydrofuran)-insoluble content and the remainder of a THF-soluble content including a component with a molecular weight of 10000 or below on a GPC (gel permeation chromatography) chromatogram of the THF-soluble content constituting 10-50 wt.

Abstract: An image forming method, including the steps of: developing an electrostatic image formed on an electrostatic image-bearing member with a developer to form thereon thereon a developed image, the developer containing 100 wt. parts of a toner and 0.05 to 3 wt. parts of fine powder treated with a silicone oil or silicone varnish; and transferring the developed image on the electrostatic image-bearing member to a transfer material while causing a transfer device, such as a roller or belt to contact the electrostatic image-bearing member by the medium of the transfer material under a line pressure of 3 g/cm or higher.

Abstract: An image forming apparatus includes a member to be charged for carrying an electrostatic image, a contact-charging means for charging the member to be charged in contact with the member to be charged, and a developing means for developing the electrostatic image carried on the member to be charged. The developing means includes a developer for developing the electrostatic image comprising a toner and hydrophobic inorganic fine powder. The hydrophobic inorganic fine powder not only improves the fluidity of the developer and adjusts the chargeability of the developer but also prevents difficulties due to interaction between the member to be charged and the contact charging means in the presence of residual developer, such as damages of the member to be charged and toner-sticking onto the member to be charged.

Abstract: An image forming method, including the steps of: developing an electrostatic image formed on an electrostatic image-bearing member with a developer to form thereon thereon a developed image, the developer containing 100 wt. parts of a toner and 0.05 to 3 wt. parts of fine powder treated with a silicone oil or silicone varnish; and transferring the developed image on the electrostatic image-bearing member to a transfer material while causing a transfer device, such as a roller or belt, to contact the electrostatic image-bearing member by the medium of the transfer material under a line pressure of 3 g/cm or higher.

Abstract: An image forming apparatus is constituted by an image-bearing member for bearing a latent image, and a developing apparatus for developing the latent image. The developing apparatus is constituted by a developer container for containing a toner, and a developer-carrying member for carrying and conveying the toner contained in the developer container to a developing zone opposite the image-bearing member. The developer-carrying member is provided with a coating layer containing electroconductive fine particles. A developer suitable for use in the above developing apparatus is given by a toner, which comprises a binder resin composition which contains 10-70 wt. % of a THF (tetrahydrofuran)-insoluble content and the remainder of a THF-soluble content including a component with a molecular weight of 10000 or below on a GPC (gel permeation chromatography) chromatogram of the THF-soluble content constituting 10-50 wt. % of the binder resin.

Abstract: A developer for developing electrostatic images, comprising: at least, 100 wt. parts of a negatively chargeable magnetic toner having a volume-average particle size of 5 to 30 microns; 0.1 to 3 wt. parts of positively chargeable resin particles having an average particle size of 0.1 to 1.0 micron; and 0.05 to 3 wt. parts of hydrophobic silica fine powder having a triboelectric chargeability of -100 to -300 .mu.c/g.

Abstract: A developer for developing electrostatic images, comprising: at least, 100 wt. parts of a negatively chargeable magnetic toner having a volume-average particle size of 5 to 30 microns; 0.1 to 3 wt. parts of potitively chargeable resin particles having an average particle size of 0.1 to 1.0 micron; and 0.05 to 3 wt. parts of hydrophobic silica fine powder having a triboelectric chargeability of -100 to -300 .mu.c/g.

Abstract: A positively chargeable, one component type magnetic developer, comprises:100 parts by weight of a positively chargeable magnetic toner having triboelectric charges of +9 .mu.c/g to +20 .mu.c/g and a volume average particle size of 5 to 30 .mu.m,0.01 to 5 parts by weight of negatively chargeable resin fine particles having triboelectric charges of -10 .mu.c/g to -40 .mu.c/g and a primary average particle size of 0.01 to 4 .mu.m, and0.05 to 10 parts by weight of positively chargeable silica fine particles having triboelectric charges of +100 to +300 .mu.c/g and a primary average particle size of 5 m.mu. to 30 m.mu..

Abstract: An encapsulated toner is provided by coating core particles with an outer shell. The outer shell comprises, as predominant components thereof, vinyl polymers A and B of different molecular weights. More specifically, the ratio of the number-average molecular weight of the vinyl polymer A (Mn.sub.A) to that of the vinyl polymer B (Mn.sub.B) is in the range of 2 to 15. The vinyl polymers A and B respectively have a ratio of weight-average molecular weight to number-average molecular weight of 5 or less. Because of these specific molecular weight characteristics of the shell-constituting polymers, the durability and triboelectric charging characteristics of the encapsulated toner are improved. These effects are enhanced particularly when inorganic fine particles are attached to embedded in the surface or surface layer of the core particles.

Abstract: An encapsulated toner for development of electrical latent images comprises a core particle containing a colorant and a soft solid material, inorganic fine particles attached to the vicinity of the surface of the core particle, and a shell coating the core particle and the inorganic fine particles. The inorganic fine particles function to, e.g., reinforce the encapsulated toner with a thin shell and may be attached to the core particles through dry-mixing. The core particles with the attached inorganic particles may be coated with a shell resin through phase separation.

Abstract: A magnetic toner comprises magnetic powders having a particle distribution that the particle size of 50% accumulated volume, the particle size of 25% accumulated volume and the particle size of 75% accumulated volume of the magnetic powders are 1.5-4.5.mu., 1.0-4.0.mu. and 2.5-6.0.mu., respectively. This magnetic toner can produce high density and clear images and further, can produce colorful images.

Abstract: An electrophotographic developer comprises magnetic particles coated with a low surface energy resin, toner particles and electroconductive fine powders. This developer can develop solid areas uniformly and does not form fog.

Abstract: Red to sepia magnetic toners stable to heat and light which do not fade or discolor for a long period of time are prepared by incorporating a partially .alpha.-transformed .gamma.-Fe.sub.2 O.sub.3 as a component in a toner.