System and Method for Transfixing an Aqueous Ink in an Image Transfer System

Abstract

An image transfer medium for transferring an ink image onto a substrate is provided on its surface with a layer of particles that include an aggregation treatment agent capable of crashing out colorants, latex and/or resin in the liquid ink. The particles can include a surfactant or separate particles consisting essentially of a surfactant can be mixed with particles consisting essentially of the aggregation treatment agent.

What is claimed is: 
     
         1 . An image transfer medium for transferring an ink image onto a substrate, comprising:
 a surface adapted to receive liquid ink and to engage the substrate to transfer an ink image thereto; and   a layer of particles affixed on said surface to receive the liquid ink, each of said particles including a surfactant and an aggregation treatment agent capable of crashing out colorants, latex and/or resin in the liquid ink.   
     
     
         2 . The image transfer medium of  claim 1 , wherein the aggregation treatment agent includes a metal salt. 
     
     
         3 . The image transfer medium of  claim 2 , wherein the metal salt includes metal ions selected from the group Ca, Cu, Ni, Mg, Zn, Fe and Al. 
     
     
         4 . The method for transferring an ink image of  claim 3 , wherein the particles include one or more of copper sulfate and iron sulfate. 
     
     
         5 . The image transfer medium of  claim 1 , wherein the aggregation treatment agent includes an anion capable of crashing the colorant, latex and/or resin. 
     
     
         6 . The image transfer medium of  claim 5 , wherein the aggregation treatment agent includes anions containing one or more of NO 3 , SO 4 , I, Br, ClO 3  and RCOO—, where R is an alkyl group. 
     
     
         7 . The image transfer medium of  claim 1 , wherein the particles are distributed substantially uniformly with a density in the range of 5%-40% on the surface. 
     
     
         8 . The image transfer medium of  claim 1 , wherein each of the particles has a diameter of 1.0-10.0 μm. 
     
     
         9 . The image transfer medium of  claim 1 , wherein the particles are affixed on the surface by one or more of the techniques including triboelectric or ion charging, electrostatic precipitation and adhesion dusting. 
     
     
         10 . The image transfer medium of  claim 1 , wherein the surface is roughened with the layer of particles disposed on the roughened surface. 
     
     
         11 . An image transfer medium for transferring an ink image onto a substrate, comprising:
 a surface adapted to receive liquid ink and to engage the substrate to transfer an ink image thereto; and   a layer of particles affixed on said surface to receive the liquid ink, the layer of particles including particles consisting essentially of a surfactant mixed with particles consisting essentially of an aggregation treatment agent capable of crashing out colorants, latex and/or resin in the liquid ink.   
     
     
         12 . The image transfer medium of  claim 11 , wherein the aggregation treatment agent includes a metal salt having metal ions selected from the group Ca, Cu, Ni, Mg, Zn, Fe and Al. 
     
     
         13 . The image transfer medium of  claim 11 , wherein the aggregation treatment agent includes anions containing one or more of NO 3 , SO 4 , I, Br, ClO 3  and RCOO—, where R is an alkyl group. 
     
     
         14 . The image transfer medium of  claim 11 , wherein the particles including the aggregation treatment agent are distributed substantially uniformly with a density in the range of 5%-40% on the surface. 
     
     
         15 . The image transfer medium of  claim 11 , wherein the particles including the aggregation treatment agent have a diameter of 1.0-10.0 μm. 
     
     
         16 . The image transfer medium of  claim 11 , wherein the surface is roughened with the layer of particles disposed on the roughened surface. 
     
     
         17 . A composition to be affixed on the surface of an image transfer medium for transferring an ink image onto a substrate, the surface adapted to receive liquid ink and to engage the substrate to transfer an ink image thereto, the composition comprising:
 a plurality of particles adapted to be affixed on said surface by one of triboelectric or ion charging, electrostatic precipitation and adhesion dusting,   wherein either (a) each of said plurality of particles includes a surfactant and an aggregation treatment agent capable of crashing out colorants, latex and/or resin in the liquid ink, or (b) said plurality of particles includes particles consisting essentially of a surfactant mixed with particles consisting essentially of an aggregation treatment agent capable of crashing out colorants, latex and/or resin in the liquid ink.   
     
     
         18 . The image transfer medium of  claim 17 , wherein the aggregation treatment agent includes a metal salt having metal ions selected from the group Ca, Cu, Ni, Mg, Zn, Fe and Al. 
     
     
         19 . The image transfer medium of  claim 17 , wherein the aggregation treatment agent includes anions containing one or more of NO 3 , SO 4 , I, Br, ClO 3  and RCOO—, where R is an alkyl group. 
     
     
         20 . The image transfer medium of  claim 11 , wherein each of the plurality of particles has a diameter of 1.0-10.0 μm.