Toner formulation for controlling mass flow
View Patent ↗The present invention relates to controlling the mass flow of toner in an image forming device or a toner cartridge. The toner composition includes extra particulate additives including a conductive additive. The extra particulate additives may also include relatively small silica particles or relatively large silica.
1. A toner composition comprising:
toner particles having a size of about 1-25 μm;
silica particles having an average diameter D 1 and an average diameter D 2 wherein D 1 <D 2 ;
alumina coated titania particles having a particle diameter of 0.1 μm to 1 μm; and
conductive additive having a volume resistivity in the range of about E −6 to E 6 ohm-cm wherein said conductive additive is present at a concentration to provide a mass flow of about 0.2 to 1.5 mg/cm 2 .
2. The conductive additive of claim 1 at a concentration of about 0.01 to 5.0% by weight of the toner.
3. The toner composition of claim 1 wherein said silica particles having a diameter of D 1 are present at a concentration that is less than the concentration of said silica particles having a diameter of D 2 .
4. The toner composition of claim 1 wherein said silica particles having a diameter D 1 are present at a concentration of about 0.1-0.5% by weight of toner.
5. The toner composition of claim 1 wherein said silica particles having a diameter D 2 are present at a concentration of about 0.1-1.5% by weight of toner.
6. The toner composition of claim 1 wherein said alumina coated titania particles are present in the range of about 0.1 to 0.5% by weight of the toner.
7. The toner composition of claim 1 wherein said alumina coated titania particles are present in the range of about 0.1 to about 0.5% by weight of the toner, said silica particles having a diameter D 1 are present in the range of about 0.1 to 0.5% by weight of the toner, said silica particles having a diameter D 2 are present in the range of about 0.1 to 1.5% by weight of the toner, and said conductive additives are present in the range of about 0.1 to 0.8% by weight of the toner.
8. The toner composition of claim 1 wherein conductive additive comprises antimony oxide doped tin oxide coated titania or antimony oxide/tin oxide coated silica.
9. The toner composition of claim 1 wherein said conductive additives is an acicular antimony oxide doped tin oxide coated titania.
10. The toner composition of claim 1 wherein said conductive additive is a substantially spherical antimony oxide doped tin oxide particle.
11. The toner composition of claim 1 wherein said conductive additive has a particle size of about 5 nm-2000 nm.
12. The toner composition of claim 1 wherein said toner exhibits a mass flow of about 0.4 to 0.8 mg/cm 2 .
13. A method for controlling the mass flow of toner having particle size of about 1-25 μm comprising:
mixing said toner with silica particles having a diameter D 1 , silica particles having a diameter D 2 , alumina coated titania particles having a particle diameter of 0.1 μm to 1 μm, and a conductive additive, wherein said conductive additive has a volume resistivity in the range of about E −6 to E 6 ohm-cm and wherein said conductive additive is combined with said toner at a concentration to provide a mass flow of about 0.2 to 1.5 mg/cm 2 .
14. The method of claim 13 wherein said conductive additive is in the range of about 0.01 to 5.0% by weight of the toner.
15. The method of claim 13 further comprising mixing said toner with silica particles having an average diameter D 1 and an average diameter D 2 wherein D 1 <D 2 .
16. The method of claim 15 wherein said silica particles having a diameter of D 1 are present at a concentration that is less than the concentration of said silica particles having a diameter of D 2 .
17. The method of claim 13 wherein said silica particles having a diameter D 1 are present at a concentration of about 0.1-0.5% by weight of toner.
18. The method of claim 13 wherein said silica particles having a diameter D 2 are present at a concentration of about 0.1-1.5% by weight of toner.
19. The method of claim 13 wherein said alumina coated titania particles are present in the range of about 0.1 to 0.5% by weight of the toner.
20. The method of claim 13 wherein said silica particles having a diameter D 1 are present in the range of about 0.1 to 0.5% by weight of the toner, said silica particles having a diameter D 2 are present in the range of about 0.1 to 1.5% by weight of the toner, said alumina coated titania particles are present in the range of about 0.1 to about 0.5% by weight of the toner and said conductive additives are present in the range of about 0.1 to 0.8% by weight of the toner.
21. The method of claim 13 wherein conductive additive comprises antimony oxide doped tin oxide coated titania or antimony oxide/tin oxide coated silica.
22. The method of claim 13 wherein said conductive additives is an acicular antimony oxide doped tin oxide coated titania.
23. The method of claim 13 wherein said conductive additive is a substantially spherical antimony oxide doped tin oxide particle.
24. The method of claim 13 wherein said mass flow is about 0.2 to 1.5 mg/cm 2 .