The present invention is generally directed to toner processes, and more specifically, to aggregation and coalescence or fusion of latex, colorant, like pigment, dye, or mixtures thereof, and optional additive particles, and wherein after the toner is generated there is added thereto a monomer with a surfactant, especially a cleavable surfactant as illustrated in U.S. Pat. No. 5,766,818, subsequently allowing the monomer to absorb on the toner and accomplishing polymerization by heating. In embodiments, the present invention is directed to toner processes which provide toner compositions with, for example, a volume average diameter of from about 1 micron to about 25 microns, and preferably from about 2 microns to about 12 microns, and a narrow particle size distribution of, for example, from about 1.10 to about 1.35, the size and distribution each being measured by the Coulter Counter method without the need to resort to conventional pulverization and classification methods, and wherein a monomer, which is stabilized using a hydrolyzable or cleavable surfactant is selected, and which surfactant hydrolyzes under basic conditions, and wherein more specifically, the surfactant is modified or hydrolyzed into a hydrophobic alkylphenol and a hydrophilic polyethylene glycol under basic conditions wherein the pH is, for example, preferably in the range of from about 7 to about 13 and more preferably in the range of from about 8.5 to about 12, followed by the releasing of the monomer, such as a fluoromonomer, into a slurry of toner particles in water, and which fluoromonomer is present in the water in the amount range of, for example, from about 1 to about 30 percent by weight, and wherein the monomer subsequently adsorbs over a time period in the range of, for example, about 2 to about 180 minutes, and preferably from about 30 to about 125 minutes onto the toner surface, which monomer is then polymerized by, for example, heating the toner slurry containing initiator, toner and fluorinated monomer in the amount of, for example, about 15.degree. C. to 100.degree. C. (Centigrade) and preferably between 20.degree. C. to 80.degree. C. to provide a suitable toner triboelectrical charge and acceptable charge distributions primarily because of the monomer adsorption. There is thus permitted monomer on the toner surface prior to polymerization thereby enabling a substantially even coating of polymer on each toner particle. In important embodiments, the present invention relates to the use of cleavable nonionic surfactants, and which surfactants can be readily hydrolyzed by, for example, the addition of base to the surfactant in the pH range of from about 8 to about 13. In embodiments, the present invention relates to the selection of cleavable surfactants of the formulas illustrated, or mixtures thereof, in emulsion/aggregation/coalescence processes, and wherein in embodiments, such surfactants, contain a phosphate ester linkage in the main chain. The resulting toners can be selected for known electrophotographic imaging and printing processes, including digital color processes.
The toners generated with the processes of the present invention are especially useful for imaging processes, especially xerographic processes, which usually require high, for example about 90 to about 98 percent, toner transfer efficiency, such as those with a compact machine design without a cleaner or those that are designed to provide high quality colored images with excellent image resolution, acceptable signal-to-noise ratio, and image uniformity.
USPTO Backgrounds
USPTO Backgrounds