Toner for developing electrostatic charge image
View Patent ↗To provide a toner for developing an electrostatic charge image, which is free from fogging even by means of a high speed and long operating life machine and which brings about no OPC filming or soiling of components. A toner for developing an electrostatic charge image, which contains at least a binder resin and a colorant, wherein the toner has silica particles satisfying at least the following (1) to (3) and particles having an electrostatic property antipolar to the silica particles: (1) the average primary particle diameter is at least 60 nm and at most 300 nm, (2) the moisture content is at most 1.0 mass %, and (3) the absolute specific gravity is at least 2.0 and at most 2.4.
1. A toner for developing an electrostatic charge image, comprising:
a binder resin;
a colorant;
silica particles satisfying:
(1) an average primary particle diameter of from 60 nm to 300 nm,
(2) a moisture content of less than 0.5 mass %, and
(3) an absolute specific gravity of from 2.0 to 2.4; and
particles having an electrostatic property antipolar to the silica particles.
2. The toner for developing an electrostatic charge image according to claim 1 , wherein the silica particles are prepared by a dry method.
3. The toner for developing an electrostatic charge image according to claim 1 , wherein the particles having an electrostatic property antipolar to the silica particles are melamine resin particles, acrylic resin particles or silica particles.
4. The toner for developing an electrostatic charge image according to claim 1 , wherein the silica particles have their surface subjected to hydrophobic treatment.
5. The toner for developing an electrostatic charge image according to claim 1 , wherein the particles having an electrostatic property antipolar to the silica particles have an average primary particle diameter of at least 80 nm and at most 300 nm.
6. The toner for developing an electrostatic charge image according to claim 1 , wherein the silica particles and the particles having an electrostatic property antipolar to the silica particles, are attached or fixed to the surface of toner matrix particles.
7. The toner for developing an electrostatic charge image according to claim 1 , wherein the toner further contains wax.
8. The toner for developing an electrostatic charge image according to claim 1 , wherein the toner is produced by a pulverization method or a wet method.
9. The toner for developing an electrostatic charge image according to claim 1 , wherein the toner has a volume median diameter of from 4 to 8 μm and an average circularity of from 0.955 to 0.985.
10. An image-forming method by means of an electrophotographic method provided at least with a photoreceptor, a toner, an electrification device and a transfer device, characterized in that the toner for developing an electrostatic charge image as defined in claim 1 is used for a non-magnetic one-component development method.
11. The image-forming method according to claim 10 , wherein the development rate is at least 100 mm/sec.
12. The toner for developing an electrostatic charge image according to claim 1 , wherein the moisture content of the silica particles is 0.12 mass % or less.