Claims
- 1. A liquid toner for electrostatic imaging which comprises:
an insulating non-polar carrier liquid; at least one charge director; and toner particles dispersed in the carrier liquid, the particles comprising:
a core material comprising a pigmented polymer which is unchargeable or weakly chargeable by the at least one charge director, but which in otherwise suitable for use as a toner material; and a coating of at least one ionomer component in an amount effective to impart enhanced chargeability to the ordinarily unchargeable or weakly chargeable particles.
- 2. A liquid toner for electrostatic imaging which comprises:
an insulating non-polar carrier liquid; at least one charge director; and toner particles dispersed in the carrier liquid, the toner particles comprising:
a core material which is chargeable to a first polarity by the at least one charge director; and a coating of at least one ionomer component in an amount effective, together the at least one charge director, to impart a charge having a polarity different from the first polarity to the coated particles.
- 3. Liquid toner according to claim 1 or claim 2, wherein the particles are synthetic rein particles.
- 4. Liquid toner according to any of the preceding claims wherein the ionomers are carboxylic acid based and neutralized with metal salts forming ionic clusters.
- 5. Liquid toner according to any of claims 1-3 wherein the ionomers are metacrylic acid based and neutralized with metal salts forming ionic clusters.
- 6. Liquid toner according to any of claims 1-3 wherein the ionomers are sulfonic acid based and neutralized with metal salts forming ionic clusters.
- 7. Liquid toner according to any of claims 1-3 wherein the ionomers are phosphoric acid based and neutralized with metal salts forming ionic clusters.
- 8. Liquid toner according to any of claims 1-3 wherein the ionomers are ethylene based and neutralized with metal salts forming ionic clusters.
- 9. A method for producing liquid toners for electrostatic imaging, which method comprises dispersing pigmented polymer particles in insulating non-polar carrier liquid, and mixing at least one ionomer which is not soluble at room temperature with the dispersion.
- 10. A method according to claim 9 wherein the ionomer in first heated to a temperature at which the ionomer dissolves in the carrier liquid and then cooled to a temperature whereat the ionomer is not soluble in the carrier liquid, thereby coating the particles with ionomer material.
- 11. A method according to claim 10 wherein the mixture is agitated at least during the step of cooling.
- 12. A method according to any of claims 9-11 and comprising the step of adding at least one charge director to the mixture.
- 13. A method according to claim 10 or claim 11 and comprising the step of adding at least one charge director to the mixture after the step of cooling.
- 14. A method according to claim 12 or claim 13 wherein the particles are formed of a material which in presence of charge director alone are ordinarily unchargeable or weekly chargeable, but are otherwise suitable for use as toner particles, and the at least one ionomer component is used in an amount effective to impart enhanced chargeability to the toner particles.
- 15. A method according to claim 12 or claim 13, wherein the at least one ionomer component is used in an amount effective to reverse the polarity conventionally imparted to the material of the particles by the at least one charge director.
- 16. A method according to any of claims 9-15, wherein the particles are comprised of a synthetic resin.
- 17. A method according to any of claims 9-15 wherein the ionomers are carboxylic acid based and neutralized with metal salts forming ionic clusters.
- 18. A method according to any of claims 9-15 wherein the ionomers are metacrylic acid based and neutralized with metal salts forming ionic clusters.
- 19. A method according to any of claims 9-15 wherein the ionomers are sulfonic acid based and neutralized with metal salts forming ionic clusters.
- 20. A method according to any of claims 9-15 wherein the ionomers are phosphoric acid based and neutralized with metal salts forming ionic clusters.
- 21. A method according to any of claims 9-15 wherein the ionomers are ethylene based and neutralized with metal salts forming ionic clusters.
- 22. Liquid toner according to any of claims 1-8 wherein the coating comprises less than 20 percent of the weight of the particles.
- 23. Liquid toner according to any of claims 1-8 wherein the coating comprises less than 10 percent of the weight of the particles.
- 24. Liquid toner according to any of claims 1-8 wherein the coating comprises less than 5 percent of the weight of the particles.
- 25. Liquid toner according to any of claims 1-8 or 22-24 wherein the coating comprises a thickness effective in improving the chargeability of the toner particles.
- 26. Liquid toner according to any of claims 1-8 or 22-25 wherein the coating comprises a thickness greater than or equal to a monolayer of the ionomer.
- 27. Liquid toner according to claim 26 wherein the coating comprises a thickness of greater than 0.02 micrometers.
- 28. An electrostatic imaging process which comprises the steps of:
forming a charged latent electrostatic image on a photoconductive surface; applying to the surface toner particles from a liquid toner according to any of claims 1-8 or 22-27; and transferring the resulting toner image to a substrate.
- 29. An electrostatic imaging process which comprises the steps of:
forming a charged latent electrostatic image on a photoconductive surface; applying to the surface charged colorant particles from a liquid toner prepared according to the method of any one of claims 9-21; and transferring the resulting toner image to a substrate.
Priority Claims (1)
Number |
Date |
Country |
Kind |
106571 |
Aug 1993 |
IL |
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 08/583,009, filed Sep. 6, 1993, which is the U.S. National Stage of International Application No. PCT/NL93/00181, filed Sep. 6, 1993. The entire disclosure of application Ser. No. 08/583,009 is considered as being part of the disclosure of this application, and the entire disclosure of application Ser. No. 08/583,009 is expressly incorporated by reference herein in its entirety.
Continuations (2)
|
Number |
Date |
Country |
Parent |
08987591 |
Dec 1997 |
US |
Child |
10039481 |
Jan 2002 |
US |
Parent |
08583009 |
Jan 1996 |
US |
Child |
08987591 |
Dec 1997 |
US |