Claims
- 1. A process for producing a toner for electrophotography which comprises polymerizing a polymerizable monomer dispersed by emulsification in the presence of a colorant and/or a magnetic powder to prepare a principal resin component, and then effecting the coagulation of the resulting polymerization liquid by adding a coagulating agent and at a temperature now lower than the glass transition point of the principal resin component so that the particles in the liquid after coagulation have diameters suitable as a toner.
- 2. A process according to claim 1, wherein the coagulation is conducted at a temperature not lower than the glass transition point of the principal resin component and not higher than 150.degree. C.
- 3. A process according to claim 1, wherein the coagulation is conducted at a temperature 25.degree. to 60.degree. C. higher than the glass transition point of the principal resin component.
- 4. A process according to claim 1, wherein the coagulating agent is added in the coagulation in an amount of 0.1 to 5 times the weight of the emulsifier present in the polymerization liquid.
- 5. A process according to claim 4, wherein the addition of the coagulating agent is conducted by the addition of a aqueous solution of the coagulating agent.
- 6. A process according to claim 4, wherein the coagulating agent is at least one compound selected from the group consisting of inorganic acids, organic acids and water soluble metal salts thereof.
- 7. A process according to claim 1, wherein the polymerization initiator used in the polymerization is an oil soluble initiator and/or a water soluble initiator.
- 8. A process according to claim 7, wherein the polymerization initiator is an oil soluble one or a combination of an oil soluble one and a water soluble one which is smaller in amount than the weight of the oil soluble one.
- 9. A process according to claim 1, wherein the dispersion by emulsification is conducted by means of a high-speed shear dispersing machine.
- 10. A process according to claim 1, wherein the polymerizable monomer comprises 40 to 100% by weight of styrene or one or more derivatives thereof.
- 11. A process according to claim 1, wherein a liquid dispersion of an offset prevention agent is added to the polymerization liquid at the time when the conversion is 90% by weight or higher.
- 12. A process according to claim 1, wherein a liquid dispersion of an offset prevention agent is added to and mixed with the polymerization liquid before or after the coagulation.
- 13. A process according to claim 11, wherein the offset prevention agent is a low molecular weight olefin polymer.
- 14. A process according to claim 11, wherein a liquid dispersion of the offset prevention agent is added so as to give a content of the agent in the toner obtained of 0.1 to 30% by weight.
- 15. A process according to claim 1, wherein the particles after the coagulation are washed with warm water.
- 16. A process according to claim 15, wherein the temperature of the warm water is 40.degree. to 100.degree. C.
- 17. A process according to claim 15, wherein the temperature of the warm water is 40.degree. to 60.degree. C.
- 18. A toner for electrophotography produced by the process of claim 1.
- 19. A toner for electrophotography produced by the process of claim 11.
- 20. A process for producing a toner for electrophotography which comprises polymerizing a polymerizable monomer dispersed by emulsification in the presence of a colorant and/or a magnetic powder to prepare a principal resin component, and then effecting the coagulation of the resulting polymerization liquid in such a way that the particles in the liquid after coagulation have diameters suitable as a toner.
- 21. A process according to claim 20, wherein a coagulating agent is added in the coagulation step.
Priority Claims (5)
Number |
Date |
Country |
Kind |
59-77064 |
Apr 1984 |
JPX |
|
59-81483 |
Apr 1984 |
JPX |
|
60-8917 |
Jan 1985 |
JPX |
|
60-8918 |
Jan 1985 |
JPX |
|
60-8919 |
Jan 1985 |
JPX |
|
Parent Case Info
This is a division of application Ser. No. 501,733, U.S. Pat. No. 4,983,488, filed on Mar. 30, 1990, which is a continuation of application Ser. No. 724,202, filed on Apr. 17, 1985 now abandoned.
US Referenced Citations (4)
Foreign Referenced Citations (3)
Number |
Date |
Country |
895943 |
Mar 1972 |
CAX |
1404061 |
Aug 1975 |
GBX |
2070029 |
Sep 1981 |
GBX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
501733 |
Mar 1990 |
|
Continuations (1)
|
Number |
Date |
Country |
Parent |
724202 |
Apr 1985 |
|