Sinloihi Company Limited

Konishiroku Photo Industry Co., Ltd.

Sadayasu Miyahara

Yoshihiko Hyosu

Saburo Wakimoto

Makoto Tomono

Hiroyuki Takagiwa

Tsuneo Wada

Goichi Yamakawa

Tetsumasa Ishida

Eiiti Miyashita

Kenzi Thuzita

Noboru Kuzuba

Ryoshiro Takano

Toner for developing electrostatically charged images comprising nuclear particles formed by polymerization, hydrophobic silica, and a resin, wherein said resin is coated on said nuclear particles and said silica is dispersed in said resin. A method for producing said toner is also disclosed, said method comprising polymerizing nuclear particles, dissolving a resin in a solvent, which asserts a lesser solvating action against said nuclear particles than against said resin, to form a solution, dispersing said hydrophobic silica in said solution, mixing said nuclear particles with said dispersion, and drying said mixture.

Triboelectric stabilized toner for developing electrically charged

A suspension polymerization of polymerizable monomers containing a prepolymer is conducted in a system containing an inorganic dispersion stabilizer and occasionally, an inorganic pigment and/or black coloring agent, in which the polymerizable monomers have an opposite charge in water to the inorganic dispersion stabilizer whereby the former is ionically bound with the latter. The suspension polymerization during the middle stage in which polymer particles are apt to stick together is stabilized and the polymer particles are prevented from coalescing so that fine spherical polymer particles are obtained with a uniform particle size distribution. Also, the suspension polymerization is conducted having liquid resins involved in polymerizable monomers thereby to obtain non-sticky, free flowing particles. These particles adhere to paper sheets by mechanically smashing.

Fine spherical polymer particles and process for the preparation thereof

A suspension polymerization of polymerizable monomers is conducted in a system containing an inorganic dispersion stabilizer and an inorganic pigment and/or black coloring agent, in which the polymerizable monomers have an opposite charge in water to the inorganic dispersion stabilizer whereby the former is ionically bound with the latter. The suspension polymerization during the middle stage in which polymer particles are apt to stick together is stabilized and the polymer particles are prevented from coalescing so that fine spherical polymer particles are obtained with a uniform particle size distribution. Also, the suspension polymerization is conducted having liquid resins involved in polymerizable monomers thereby to obtain non-sticky, free flowing particles. These particles adhere to paper sheets by mechnically smashing.

Fine spherical polymer particles containing inorganic pigment and/or

A suspension polymerization of polymerizable monomers is conducted in a system containing an inorganic dispersion stabilizer and an inorganic pigment and/or black coloring agent, in which the polymerizable monomers have an opposite charge in water to the inorganic dispersion stabilizer whereby the former is ionically bound with the latter. The suspension polymerization during the middle stage in which polymer particles are apt to stick together is stabilized and the polymer particles are prevented from coalescing so that fine spherical polymer particles are obtained with a uniform particle size distribution. Also, the suspension polymerization is conducted having liquid resins involved in polymerizable monomers thereby to obtain non-sticky, free flowing particles. These particles adhere to paper sheets by mechanically smashing.

Colored resin particles which are colored uniformly and densely and are excellent in fluorescence, light fastness and washing resistance are prepared by copolymerizing in an aqueous medium in the presence of a water-soluble fluorescent dye (1) a polymerizable unsaturated monomer A having a low affinity for the fluorescent dye, (2) a polymerizable unsaturated monomer B having at least one cyano group and (3) a polymerizable unsaturated monomer C having a high affinity for the fluorescent dye and being insoluble or barely soluble in water, which is represented by the following general formula ##STR1## wherein X is a hydrogen atom or a methyl group.

Growing community of inventors

Fujisawa, Japan

Sadayasu Miyahara