Magnetic toner compositions
AssigneeXerox Corporation
InventorsKe Zhou, Suxia Yang, Cuong Vong, Paul J. Gerroir, Karen Ann Moffat, Gabriel Iftime
Life of this patent
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Abstract
The present disclosure relates to a process for preparing a polyester-based magnetic toner composition. The toner composition includes one or more polyester amorphous binder resins, optionally a crystalline polyester resin, and spherical barium iron oxide particles. In embodiments, the toner is prepared from barium iron oxide particles that are in a dispersion including water and a dispersant. In yet other embodiments, the process may be conducted under an inert gas such as argon to avoid oxidation of the ferromagnetic particles during toner preparation.
Claims20
An emulsion aggregation toner comprising:
- at least one resin in combination with one or more optional ingredients selected from the group consisting of colorants, waxes, and combinations thereof;
- and
- a plurality of magnetic metal oxide nanoparticles,
- wherein the magnetic metal oxide is of the formula MxNyOz, wherein M is selected from the group consisting of Mn, Co, Ni, Mg, Cu, Zn, Ba, Sr, and combinations thereof, N is selected from the group consisting of Fe, Co, Ni, and combinations thereof, x is from 0.1 to 20, y is from 1 to 20, and z is from 1 to 40.
A process comprising:
- contacting at least one resin emulsion and a plurality of magnetic metal oxide nanoparticles in a mixture;
- aggregating the mixture at a pH from about 1 to about 6 to form particles;
- adjusting the pH of the mixture to from about 6 to about 14 to stop growth of the particles;
- coalescing the particles at a pH from about 3 to about 9 to form toner particles;
- and
- recovering the toner particles,
- wherein the magnetic metal oxide is of the formula MxNyOz, wherein M is selected from the group consisting of Mn, Co, Ni, Mg, Cu, Zn, Ba, Sr, and combinations thereof, N is selected from the group consisting of Fe, Co, Ni, and combinations thereof, x is from 0.1 to 20, y is from 1 to 20, and z is from 1 to 40.
A process comprising:
- contacting at least one resin emulsion and a plurality of magnetic metal oxide nanoparticles in a mixture;
- aggregating the mixture at a pH from about 1 to about 6 to form particles;
- adjusting the pH of the mixture to from about 6 to about 14 to stop growth of the particles;
- coalescing the particles at a pH from about 3 to about 9 to form toner particles;
- and
- recovering the toner particles,
- wherein the magnetic metal oxide is of the formula MxNyOz, wherein M is selected from the group consisting of Mn Co, Ni, Mg Cu, Zn, Ba, Sr, and combinations thereof, N is selected from the group consisting of Fe, Co, Ni, and combinations thereof, x is from 0.1 to 20, y is from 1 to 20, and z is from 1 to 40, and wherein the plurality of magnetic metal oxide nanoparticles possess a circularity of from about 0.65 to about 1.
Dependencies are inferred from the claim text.