Non-magnetic yellow toner
AssigneeMinolta Co., Ltd.
InventorsMasahiro Anno, Chikara Tsutsui, Minoru Nakamura, Katsunori Kurose, Hiroyuki Fukuda
Life of this patent
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Abstract
The present invention relates to a non-magnetic yellow toner for use in full-color image forming apparatuses, such as full-color electrostatic copying machines and full-color laser beam printers, comprising: non-magnetic toner particles containing a binder resin having an acid value of 1 to 30 KOHmg/g, and a coloring material composed of a compound classified as C. I. pigment yellow 180; the toner particles having a roundness of 0.94 to 1.0, a standard roundness deviation of not more than 0.045, and a volume mean particle size of 2 to 9 .mu.m.
Claims21
A negatively chargeable non-magnetic yellow toner comprising:
- non-magnetic toner particles containing a binder resin having an acid value of 1 to 30 KOHmg/g, and a coloring material composed of a compound classified as C. I. pigment yellow 180;
- the toner particles having a roundness of 0.94 to 1.0, a standard roundness deviation of not more than 0.045, and a volume mean particle size of 2 to 9 .mu.m.
A negatively chargeable non-magnetic mono-component yellow toner, comprising:
- non-magnetic toner particles containing a binder resin having an acid value of 1 to 30 KOHmg/g, and a coloring material composed of a compound classified as C. I. pigment yellow 180;
- the toner particles having a roundness of 0.94 to 1.0, a standard roundness deviation of not more than 0.045, and a volume mean particle size of 2 to 9 .mu.m.
A method of producing a non-magnetic yellow toner, comprising the steps of:
- preparing a coloring resin solution containing a binder resin, a compound classified as C. I. pigment yellow 180, and a non-aqueous organic solvent;
- emulsifying and dispersing the coloring resin solution in an aqueous medium, thereby to obtain an aqueous dispersion such that coloring resin solution particles are dispersed in an aqueous medium;
- and
- removing non-aqueous organic solvent from the coloring resin solution particles, thereby to obtain toner particles having a roundness of 0.94 to 1.0, a standard roundness deviation of not more than 0.045, and the volume mean particle size of 2 to 9 .mu.m.
A method of producing a non-magnetic yellow toner comprising the steps of:
- mixing a binder resin having an acid value of 1 to 30 KOHmg/g with a compound classified as C. I. pigment yellow 180;
- melting and kneading the resulting mixture;
- pulverizing the kneaded mixture;
- classifying the pulverized particles;
- and
- adjusting roundness of the classified particles, to give toner particles having a roundness of 0.94 to 1.0 and a standard roundness deviation of not more than 0.045.
Dependencies are inferred from the claim text.