Claims
- 1. An electrostatic imaging process comprising the steps of:
- forming a latent electrostatic image on a surface;
- applying to said surface electrically charged toner particles from a liquid developer system comprising:
- an insulating non-polar carrier liquid;
- toner particles dispersed in said carrier liquid; and
- at least one charge director compound being partly soluble in said carrier liquid and dissolved therein at its saturation concentration; thereby to form a toner image on said surface; and
- supplying an excess of said charge director compound above such saturation concentration comprised in a solid phase, said solid being in equilibrium contact with said carrier liquid for maintaining a predetermined concentration of dissolved charge director in said liquid developer system; and
- transferring the resulting toner image to a substrate.
- 2. A liquid developer system according to claim 1 wherein said solid includes particles.
- 3. A process according to claim 1 wherein said excess of charge director compound is in a finely dispersed solid form external to said toner particles and in contact with said carrier liquid.
- 4. A process according to claim 1, wherein said carrier liquid is a branched chain aliphatic hydrocarbon or a mixture of such hydrocarbons.
- 5. A process according to claim 1 wherein said carrier liquid is an isoparaffinic hydrocarbon fraction having a boiling range above 155.degree. C.
- 6. A process according to claim 1, wherein said charge director compound is ionic or zwitterionic.
- 7. A process according to claim 6, wherein said charge director compound is a metal soap.
- 8. A process according to claim 1, wherein said charge director compound is capable of imparting a negative charge to the toner particles suspended in the carrier liquid.
- 9. A process according to claim 7, wherein said charge director compound is calcium laurylbenzenesulfonate.
- 10. A process according to claim 7, wherein said charge director compound is sodium laurylbenzenesulfonate.
- 11. A process according to claim 7, wherein said charge director compound is sodium diamyl sulfosuccinate.
- 12. An electrostatic imaging process according to claim 1 wherein said step of forming comprises the steps of:
- electrostatically charging a photoconductive surface;
- exposing said photoconductive surface to an optical image thereby forming a latent electro static image on said photoconductive surface.
- 13. An imaging method including the steps of:
- developing a latent electrostatic image utilizing a liquid developer system comprising:
- an insulating non-polar carrier liquid;
- toner particles dispersed in said carrier liquid; and
- at least one charge director compound being partly soluble in said carrier liquid and dissolved therein at its saturation concentration; and
- supplying an excess of said charge director compound above such saturation concentration comprised in a solid phase, said solid being in equilibrium contact with said carrier liquid for maintaining a predetermined concentration of dissolved charge director in said liquid developer system.
- 14. An electrostatic imaging process according to claim 1 wherein said excess of charge director compound is comprised in said toner particles.
- 15. An electrostatic imaging process according to claim 12 wherein said excess of charge director compound is comprised in said toner particles.
- 16. A method for developing a latent electrostatic image in a liquid-developed electrostatic imaging process according to claim 13 wherein said excess of charge director compound is comprised in said toner particles.
- 17. An electrostatic imaging process according to claim 12 wherein said excess of charge director compound is in a finely dispersed solid form external to said toner particles and in contact with said carrier liquid.
- 18. A method for developing a latent electrostatic image in a liquid-developed electrostatic imaging process according to claim 13 wherein said excess of charge director compound is in a finely dispersed solid form external to said toner particles and in contact with said carrier liquid.
Parent Case Info
This application is a continuation of application Ser. No. 07/319,126, filed Mar. 6, 1989, now abandoned.
US Referenced Citations (14)
Continuations (1)
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Number |
Date |
Country |
Parent |
319126 |
Mar 1989 |
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