Canon Kabushiki Kaisha

Masashi Kiuchi

Yasuo Mitsuhashi

Yoshio Takasu

Masaki Uchiyama

Hiroshi Fukumoto

Takashi Hino

Isamu Maki

Yasuyuki Tamura

Toshiyuki Komatsu

Tohru Takahashi

Toshiaki Nakahara

Yasuhide Goseki

Masuo Yamazaki

Hisayuki Ochi

Ichiro Ohsaki

Hisayuki Ushiyama

Seiji Tomari

Toshio Watanabe

Mitsuo Sato

Saburo Shoji

Tatsuyoshi Kanai

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.

Encapsulated toner having shell with first vinyl polymer with Mn of

A developing device in which a one-component magnetic developer is brought into contact with an electrostatic image carrier in a developing station while it is conveyed in a predetermined direction, to thereby develop a desired electrostatic image is provided with developer carrier means carrying the one-component magnetic developer on the peripheral surface thereof and bringing the developer into contact with the electrostatic image carrier, means for moving a magnetic field along the peripheral surface of the developer carrier means to thereby move the one-component magnetic developer in the direction opposite to the direction of movement of the magnetic field, and means for moving the developer carrier means in the direction of movement of the magnetic field.

Developing method for electrostatic image

An electrophotographic process comprises the steps of:

Electrophotographic process

A toner for development comprises a crosslinked vinyl polymer having a gel content of 50-99% and a crosslinked vinyl polymer having a gel content of 10-0%.

Toner for development having crosslinked polymers

A process for development comprises arranging an electrostatic image bearing member having electrostatic images on the surface and a developer carrying member at a predetermined space, an insulating magnetic developer containing 10-50% by weight of magnetic toner particles 20-35 microns in size being carried on the developer carrying member in a thickness thinner than the predetermined space, and transferring the insulating magnetic developer to the electrostatic image bearing member in the presence of a magnetic field. According to this process for development, there can be produced developed images of high fidelity, high density and high resolution and free from fog.

Electrostatic image magnetic developing process

An electrophotographic process comprises the steps of: developing an electric latent image with toner particle, the toner particle comprising 20-70 parts by weight of at least one resin selected from resins of Group A and 80-30 parts by weight of at least resin selected from resins of Group B, transferring the developed toner image to a paper having a smoothness of 5-130 seconds (measured by Bekk method), applying pressure to the transferred toner image to fix the toner image on said paper, and repeating at least said steps, in which said resins of Group A includes a low molecular weight polyethylene, a low molecular weight polypropylene, ethylene-ethyl acrylate copolymer, ionomer resin and ethylenevinyl acetate copolymer, and said resins of Group B includes natural resin modified maleic acid resin, natural resin modified pentaerythritol resin and natural resin modified glycerine resin.

A toner for developing electrostatic images comprises a metal complex of salicylic acid or a metal complex of an alkyl salicylic acid as a charge controlling agent.

Negatively charged toner for developing electrostatic images containing

Liquid developers for use in developing electrostatic latent image which contain at least one member selected from the following Group A and at least one member selected from the following Group B.

Growing community of inventors

Toride, Japan

Masashi Kiuchi