Fuji Xerox Co., Ltd.

Kaori Ohishi

Chiaki Suzuki

Satoshi Inoue

Masahiro Takagi

Susumu Yoshino

Sueko Sakai

Yoshifumi Iida

Fusako Kiyono

Noriyuki Mizutani

Atsuhiko Eguchi

Haruhide Ishida

Rieko Kataoka

Tetsuya Taguchi

Hiroshi Nakazawa

Hirokazu Hamano

Sakon Takahashi

Takayoshi Aoki

Toshiyuki Yano

Shinpei Takagi

Yasuhiro Oya

Jun Igarashi

Yuusaku Shibuya

Electrophotographic toner, electrophotographic developer and process for forming image

Electrophotographic developer and process for forming image

The present invention provides toner for an electrostatic latent image developer, said toner being excellent in fluidity, chargeability, developability, transferability, and freedom from fogging on a photoreceptor and contamination of the interior of a developing device. The toner for an electrostatic latent image developer comprises spherical toner particles characterized by a shape index ML.sup.2 /A of less than 125 and has a correlation coefficient between X.sup.2/3 and Y, obtained by linear regression with respect to a straight line which passes through the origin of coordinate axes, of more than 0.6 where X is the light emitting voltage due to the carbon derived from the binder resin of the toner particles and Y is the light emitting voltage due to the element derived from the external additive.

Toner for developer of electrostatic latent image, method for producing

A toner for electrophotography comprising a colorant and a binder resin, wherein the toner further contains an image reinforcing agent, is disclosed. The reinforcing agent is preferably a high melt viscosity resin whose weight average molecular weight is 300 to 3000 and whose melt viscosity .eta. at 140.degree. C. is 10.sup.3 to 10.sup.6 (Pa.multidot.s). A developer for electrophotography containing a carrier and a toner comprising of a colorant and a binder resin, wherein the toner contains an image reinforcing agent, is also disclosed.

Toners for electrophotography, developers for electrophotography and

A toner comprising toner particles comprising a binder resin and a colorant, wherein the toner particles have a number average particle diameter of from 3 to 10 .mu.m and satisfy relationship (1) or (2):

Toner and developer for electrostatic latent image development and image

The present invention provides a carrier for developer of an electrostatic latent image and related technologies. The carrier is excellent in the ability to impart charge suitably and stably to toner and has a structure durable enough to maintain the ability for a long period of time such that the structure can prevent the toner from being adhered onto the carrier surface for a long period of time. The carrier comprises a core covered with a resin coating layer containing resin particles and an electroconductive fine powder in the form of a dispersion in a matrix resin. The carrier can be produced by a method comprising the steps of preparing a coating solution by placing materials in a solvent which can dissolve the matrix resin, but cannot dissolve the resin particles, dispersing the particles of the resin, applying the solution to a core and removing the solvent. A high-quality image can be formed by use of the developer comprising the carrier and the toner.

Carrier for developer of electrostatic latent image, method for making

A carrier for developing an electrostatic latent image comprising a core material coated with a resin layer, wherein the F/N ratio of the surface of the resin layer ranges from 1 to 20. It is desirable that the resin layer include resin particles containing a nitrogen atom, that the average particle diameter of the nitrogen-atom-containing resin be in a range from 0.1 to 2 .mu.m, that the thickness of the resin layer be in a range from 0.1 to 10 .mu.m, that the resin layer include an electroconductive material which is in a condition to be dispersed in the resin layer, that the electroconductive material be made of carbon black, and that the average particle diameter of the carrier for developing an electrostatic latent image be in a range from 30 to 150 .mu.m. The carrier for developing an electrostatic latent image, which is long-lived, provided with a charging capability unchanged over time, and is capable of effectively preventing fogging are provided.

Carrier for developing electrostatic latent image, electrostatic latent

The present invention provides a long-life carrier for developing an electrostatic latent image to be used in such field of applications as electrostatic photography and electrostatic recording, a developer of an electrostatic latent image utilizing said carrier, a method for forming an image and an image forming apparatus by using said developer. By use of the foregoing qualities, a high-quality image can be obtained.

Developer of electrostatic latent image, carrier therefor, method for

A toner for developing an electrostatic latent image, which comprises toner particles and treated titanium oxide fine particles obtained by coating titanium oxide fine particles with 0.1 to 2.0% by weight, in terms of Al.sub.2 O.sub.3, of aluminum or Al.sub.2 O.sub.3 and further subjecting the coated particles to surface treatment with a treating agent.

Toner and developer for developing electrostatic latent image, and image

A image formation process comprising the steps of forming an electrostatic latent image on an electrostatic latent image carrier, developing the electrostatic latent image with a developer to provide a toner image, transferring the toner image to a transfer material, and heat-fixing the toner image on the transfer material, wherein the developer comprises a toner for developing electrostatic latent images comprising a binder, a colorant, and 1 to 30% by weight of a lubricant which comprises a modified polyethylene wax which is obtained by homopolymerizing ethylene or copolymerizing ethylene and an .alpha.-olefin having 3 to 10 carbon atoms in the presence of a metallocene catalyst and modifying the resulting ethylene homo- or copolymer by grafting at least one grafting monomer selected from the group consisting of a styrene monomer and an unsaturated carboxylic acid monomer, and has a hexane extraction of not more than 65% by weight, and wherein the transfer step comprises bringing a bias roll into contact with the back side of a transfer material. The image formation process of the present invention requires less power consumption. The toner for use in the present invention provides a good releasability at low temperatures and shows excellent anti-offset properties and powder fluidity without causing the generation of ozone, image defects and blocking.

Image formation process

Growing community of inventors

Minami-Ashigara, Japan

Kaori Ohishi