Charge Director for Liquid Toner

Abstract

A charge director material for charging a liquid toner, the charge director material comprising (a) nanoparticles of a simple salt and (b) a sulfosuccinate salt of the general formula MA_n, wherein M is a metal, n is the valence of M, and A is an ion of the general formula (I)

[R₁—O—C(O)CH₂CH(SO₃⁻)C(O)—O—R₂],  (I)

• • wherein each of R₁ and R₂ is an alkyl group;
  • said charge director material being substantially free of acids of the general formula (I),
  • wherein one or both of R1 and R2 is hydrogen, and if only one of them is hydrogen, the other is an alkyl group,

Description

RELATED APPLICATIONS[0001]This application claims priority to, and is a US National Phase of, International Patent Application No. PCT / US2006 / 018297, having title “CHARGE DIRECTOR FOR LIQUID TONER”, having been filed on 10 May 2006 and having PCT Publication No. WO2007 / 130069, commonly assigned herewith, and hereby incorporated by reference.FIELD OF THE INVENTION[0002]The present application discloses charge directors in liquid electrography, some chemical materials useful as such charge directors, and methods for obtaining and using said materials.BACKGROUND OF THE INVENTION[0003]In many printing systems, it is common practice to develop a hardcopy of an image by using a photoconductive surface. The photoconductive surface is selectively charged with a latent electrostatic image having image and background areas. A liquid developer comprising charged toner particles in a carrier liquid is brought into contact with the selectively charged photoconductive surface. The charged toner p...

AI Technical Summary

Benefits of technology

[0026]Another aspect of some embodiments of the present invention is a liquid developer comprising charge director material in accordance with the present invention. In exemplary embodiments, the liquid developer may be of the kind disclosed in U.S. Pat. No. 5,346,796, the disclosure of which is incorporated herein by reference, with a charge director of the present invention replacing the charge director mentioned in the reference. The developer with

Problems solved by technology

A possible disadvantage of using a mixture of materials as charge director is the possibility of selective adsorption of certain charge director components onto the surface of the ink particles.

This may lead to differential depletion of the components responsive to their affinity to the ink particles.

Therefore, a non-controllable change in the charge director composition may be expected during continuous printing process.

This may adversely affect the long term characteristics

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