Ricoh Company, Ltd.

Yoichiro Watanabe

Mitsuo Aoki

Tetsuo Isoda

Nobuhiro Nakayama

Akihiro Kotsugai

Hiromitsu Kawase

Hiroshi Yamashita

Fumihiro Sasaki

Kimitoshi Yamaguchi

Shinichi Kuramoto

Hiroyuki Fushimi

Takamichi Enomoto

Koichi Katoh

Masanaga Imamura

Kenkichi Muto

Ian Harpur

Kouchi Ohshima

Junji Toda

Katsumi Kuboshima

Karumi Kakigawa

A method of forming a colored image on a heat resistant solid surface by use of a toner-image-layer-bearing image formation medium; a method of forming the toner-image-layer bearing image formation medium; inorganic toners for the formation of inorganic toner image for proposed.

Method of forming colored image by use of inorganic toner, inorganic

A toner prepared by allowing finely-divided particles of a vinyl resin having an alkali-reactive group to react with a fluorine-containing quaternary ammonium salt to obtain surface-modified finely-divided particles; mixing the surface-modified finely-divided particles and core particles composed of a resin and a coloring agent; and filming the above core particles with the finely-divided particles of the surface-modified vinyl resin with application of mechanical energy thereto.

Toner for developing latent electrostatic images

A method of preparing composite particles is disclosed, which comprises the steps of dispersing matrix organic resin particles having a polar group on a surface thereof in a hydrophilic organic liquid, water or mixture thereof to prepare a dispersion of the matrix organic resin particles; dispersing a wax in a hydrophilic organic liquid, water or mixture thereof by use of a nonionic surface active agent to prepare an emulsion of the wax; mixing the dispersion of the matrix organic resin particles and the emulsion of the wax in the presence of a surface active agent with a polarity opposite to that of the polar group on the matrix organic resin particles to obtain a dispersion in which finely-divided particles of the wax are caused to adhere to the surface of the matrix particles; and heating the dispersion to fix the finely-divided particles of the wax on the surface of the matrix organic resin particles.

Method of preparing composite particles comprising adhering wax

A dry type developer is composed of substantially spherical, electrically insulating toner particles which are free from electroconductive particles, and carrier particles, each carrier particle including a core particle and a resin layer coated on the surface of the core particle, with a resistivity in the range of 10.sup.8 to 10.sup.14 .OMEGA.cm under application of a DC voltage of 1000 volts.

Dry-type developer

A toner for developing latent electrostatic images is disclosed, which comprises a binder resin comprising a component selected from the group consisting of: (1) a mixture of the ternary copolymers of styrene, methyl acrylate, and ethyl acrylate, (2) a mixture of the binary copolymers of two monomers from among the monomers of styrene, methyl acrylate, and ethyl acrylate and homopolymers containing the remaining monomer or the copolymers of that monomer and the other monomers, and (3) a mixture of the respective homopolymers.

Dry toner for developing latent electrostatic images with improved

The disclosure describes carrier particles for use in a two-component dry-type developer, consisting of core particles which are coated with a silicone resin hardened by an organic tin catalyst.

Carrier particles for use in a two-component dry-type developer

A toner for developing latent electrostatic images is disclosed, which comprises a colorant, and a binder agent comprising (i) polyester resin or epoxy resin, and (ii) styrene - methyl acrylate copolymer.

Carrier particles for use in a two-component dry-type developer for developing latent electrostatic images are disclosed, which core particle comprises a core particle and a silicone resin layer coated on the core particles, and the silicone resin layer contains an organic tin compound, which serves as a catalyst for hardening the silicone resin layer in the course of the formation of the silicone resin layer on the core particle under application of heat thereto, with a concentration gradient in the direction of the thickness of the silicone resin layer towards the outer surface of the carrier particles.

Growing community of inventors

Fuji, Japan

Yoichiro Watanabe