Tomoegawa Paper Co., Inc.

Tomoegawa Co., Ltd.

Kazuyoshi Hattori

Tohru Moriya

Yoshihito Suwa

Hitoshi Onoda

A toner for electrophotography includes toner particles containing at least a binder resin and a colorant, to which strontium titanate and hydrophobic silica as external additives are admixed, wherein the strontium titanate has a BET specific surface area of 20-50 m/g and contains particles in a rectangular parallelepiped shape and wherein the hydrophobic silica contains hydrophobic silica A that has at least a BET specific surface area of 150-300 m/g and the surface of which has been treated with an aminosilane and hexamethyldisilazane and hydrophobic silica B that has at least a BET specific surface area of 90-150 m/g and the surface of which has been treated with hexamethyldisilazane.

Toner for electrophotography and process for producing the same

The present invention relates to a toner and a two-component developer which can produce high quality images with decreasing the dependence on environment and the back ground during continuous printing of a large number of sheets. The toner includes toner particles including a binder resin as a main component thereof and having particle surfaces deposited with titanium oxide particles, the surfaces of which are treated with at least isobutyl trimethoxy silane and trimethyl siloxysilicate. The two-component developer includes the toner and a carrier including core particles, the surfaces of which are coated with a resin coating agent including 5 to 20 percent by weight of carbon black, relative to the total weight of the resin coating agent.

Toner and two-component developer for electrostatic image development

A toner for electrophotography, which contains a binder resin having a low softening point so that the toner can be fixed at a low temperature, and which is free from blocking, the toner comprising

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Shizuoka, Japan

Kazuyoshi Hattori