Radiation imagery chemistry: process – composition – or product th – Electric or magnetic imagery – e.g. – xerography,... – Post imaging process – finishing – or perfecting composition...
Reexamination Certificate
2000-06-26
2001-03-20
Martin, Roland (Department: 1753)
Radiation imagery chemistry: process, composition, or product th
Electric or magnetic imagery, e.g., xerography,...
Post imaging process, finishing, or perfecting composition...
Reexamination Certificate
active
06203961
ABSTRACT:
Illustrated U.S. Pat. No. 5,627,002, the disclosure of which is totally incorporated herein by reference, is a positively charged liquid developer comprised of a nonpolar liquid, thermoplastic resin particles, pigment, a charge director, and a charge control agent comprised of a cyclodextrin or a cyclodextrin derivative containing one or more organic basic amino groups.
Disclosed in U.S. Pat. No. 5,826,147, the disclosure of which is totally incorporated herein by reference, is an electrostatic latent image development process wherein there is selected an imaging member with an imaging surface containing a layer of marking material and wherein image-wise charging can be accomplished with a wide beam ion source such that free mobile ions are introduced in the vicinity of an electrostatic image associated with the imaging member.
The disclosures of each of the following patents are totally incorporated herein by reference.
U.S. Pat. No. 5,840,462 discloses a toner process wherein a colorant is flushed into a sulfonated polyester, followed by the addition of an organic soluble dye and an alkali halide solution.
U.S. Pat. No. 5,853,944 discloses a toner process with a first aggregation of sulfonated polyester, and thereafter, a second aggregation with a colorant dispersion and an alkali halide.
U.S. Pat. No. 5,945,245 discloses a toner process wherein a latex emulsion and a colorant dispersion are mixed in the presence of an organic complexing agent or compound, and wherein the latex can contain a sodio sulfonated polyester resin.
U.S. Pat. No. 5,910,387 discloses an emulsion/aggregation/fusing process for the preparation of a toner containing a resin derived from the polymerization of styrene butadiene, acrylonitrile, and acrylic acid.
U.S. Pat. No. 5,919,595 discloses a toner process wherein there is mixed an emulsion latex, and which latex may contain a sulfonated polyester, a colorant dispersion, and a monocationic salt, and wherein the resulting mixture possesses an ionic strength of about 0.001 molar to about 5 molar.
U.S. Pat. No. 5,869,215 discloses a toner process by blending an aqueous colorant dispersion with a latex blend containing a linear polymer and soft crosslinked polymer particles.
U.S. Pat. No. 5,869,216 discloses a toner process wherein there is mixed an aqueous colorant dispersion and an emulsion latex, and which latex may contain a sulfonated polyester, followed by filtering, and redispersing the toner formed in water at a pH of above about 7 and contacting the resulting mixture with a metal halide or salt and then with a mixture of an alkaline base and a salicylic acid, a catechol, or mixtures thereof.
Illustrated in U.S. Pat. No. 5,593,807, the disclosure of which is totally incorporated herein by reference, is a process for the preparation of toner compositions comprising, for example, preparing an emulsion latex comprised of sodio sulfonated polyester resin particles of about 5 to about 500 nanometers in size diameter by heating the resin in water at a temperature of, for example, from about 65° C. to about 90° C.; preparing a colorant dispersion by dispersing in water from about 10 to about 25 weight percent of a sodio sulfonated polyester and from about 1 to about 5 weight percent of colorant; adding with shearing the colorant dispersion to the latex mixture, followed by the addition of an alkali metal halide, such as calcium chloride until aggregation results as indicated, for example, by an increase in the latex viscosity of from about 2 centipoise to about 100 centipoise; heating the resulting mixture at a temperature of from about 45° C. to about 80° C. thereby causing further aggregation and enabling coalescence, resulting in toner particles of from about 4 to about 9 microns in volume average diameter and with a geometric distribution of less than about 1.3; and optionally cooling the product mixture to about 25° C., followed by washing and drying.
Also of possible interest is U.S. Pat. No. 5,660,965, the disclosures of which is totally incorporated herein by reference.
The appropriate components and processes of the above copending applications, such as the sulfonated polyesters, may be selected for the invention of the present application in embodiments thereof.
BACKGROUND OF THE INVENTION
This invention is generally directed to liquid developer compositions and processes thereof, and wherein there can be generated improved developed images thereof in bipolar ion charging processes, and reverse charge imaging and printing development (RCP) processes, reference U.S. Pat. No. 5,826,147, the disclosure of which is totally incorporated herein by reference, and wherein the developer contains no charge director, or wherein the developer contains substantially no charge director. The liquid developer of the present invention may be clear in color and is comprised of a sulfonated polyester toner dispersed in a nonpolar solvent and wherein the polyester can be prepared by emulsion/aggregation processes as illustrated herein, and more specifically, as illustrated in the appropriate patents and patent applications recited herein and wherein the developer captures both positive and negative charges.
The present invention is also specifically directed to a electrostatographic imaging process, such as RCP processes, wherein an electrostatic latent image bearing member containing a layer of marking material, toner particles, or liquid developer as illustrated herein and containing a toner comprised of a polyester resin, colorant, and optional additives dispersed in a nonpolar liquid, such as a hydrocarbon fluid, is selectively charged in an imagewise manner to create a secondary latent image corresponding to the electrostatic latent image on the imaging member. Imagewise charging can be accomplished by a wide beam charge source for introducing free mobile charges or ions in the vicinity of the electrostatic latent image coated with the layer of marking material or toner particles. The latent image causes the free mobile charges or ions to flow in an imagewise ion stream corresponding to the latent image. These charges or ions, in turn, are accepted by the marking material or toner particles, leading to imagewise charging of the marking material or toner particles with the layer of marking material or toner particles itself becoming the latent image carrier. The latent image carrying toner layer is subsequently developed by selectively separating and transferring image areas of the toner layer to a copy substrate for producing an output document.
Moreover, the present invention relates to an imaging apparatus, wherein an electrostatic latent image including image and non-image areas is formed in a layer of marking material, and further wherein the latent image can be developed by selectively separating portions of the latent image bearing layer of the marking material such that the image areas reside on a first surface and the non-image areas reside on a second surface. In a simple embodiment, the invention relates to an image development apparatus, comprising a system for generating a first electrostatic latent image on an imaging member, wherein the electrostatic latent image includes image and non-image areas having distinguishable charge potentials, and a system for generating a second electrostatic latent image on a layer of marking materials situated adjacent the first electrostatic latent image on the imaging member, wherein the second electrostatic latent image includes image and non-image areas having distinguishable charge potentials of a polarity opposite to the charge potentials of the charged image and non-image areas in the first electrostatic latent image.
The liquid developers and processes of the present invention possess a number of advantages in embodiments including the development and generation of images with improved image quality, the avoidance of a charge director, the enablement of the developers in a reverse charging development process, excellent image transfer, and the avoidance of complex chemical charging of the developer. Poor
Pan David H.
Sacripante Guerino G.
Martin Roland
Palazzo E. O.
Xerox Corporation
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