Nippon Carbide Kogyo Kabushiki Kaisha

Hiroyoshi Shimomura

Yukinobu Hasegawa

Masatoshi Maruyama

Hiroshi Serizawa

Hitoshi Masuda

Hiroshi Kamada

Kensuke Okuda

Toyokichi Tange

Koichi Murai

A colored toner for developing electrostatic images which has a degree of gelation of 2.0% or less and comprises an association of secondary particles containing polymer particles having acidic polar groups or basic polar groups and an organic pigment and/or an organic dye treated with a treatment agent containing a surface treatment agent which has the same ionic character as the polymer particles so that the absolute value of .zeta.-potential becomes 10 to 100 mV at pH 5, and a developer for electrostatic images which comprises this colored toner and a carrier.

Colored toner for developing electrostatic images

A toner for developing an electrostatic image comprises primary colored resin particles having a mean particle size of 0.6 to 10 microns which have been agglomerated to form secondary particles having a particle size of 1.2 to 20 microns. The primary colored resin particles are formed from fine elementary particles comprised of one or more polymers and a colorant. Thus, the toner can be economically prepared, is excellent in resolution, does not cause much fogging or scattering, and is excellent in fixability and image density.

Toners for developing electrostatic image

Toner for developing an electrostatically charged image

Growing community of inventors

Hiratsuka, Japan

Hiroyoshi Shimomura