Latex-based overcoat for ink-jet printing applications

Abstract

Compositions, systems, and methods for protecting an ink-jet produced image printed on a substrate are provided. The composition can comprise a liquid vehicle and latex particulates dispersed in the liquid vehicle, wherein the latex particulates have a surface dielectric constant from 2.0 to 3.0 at room temperature, and a bulk density from 0.90 g/cm 3 to 1.10 g/cm 3 . An alternative composition can comprise a liquid vehicle and latex particulates dispersed in the liquid vehicle, wherein the latex particulates have a reactive surfactant covalently attached thereto.

1 . An overcoating composition for protecting a printed image on a substrate, said composition comprising: 
 (a) a liquid vehicle void of colorant; and    (b) latex particulates dispersed in the liquid vehicle, said latex particulates having a surface dielectric constant from 2.0 to 3.0 at room temperature, and a bulk density 0.1 g/cm 3  less to 0.1 g/cm 3  greater than the vehicle density,    wherein the latex particulates are core-shell or inverse core-shell and have a glass transition temperature from 0° C. to 50° C.    
   
   
       2 . A composition as in  claim 1 , wherein the latex particulates are present in the liquid vehicle at from 0.1 wt % to 20 wt % solids.  
   
   
       3 . A composition as in  claim 1 , wherein the latex particulates have a bulk density of from 0.90 g/cm 3  to 1.10 g/cm 3  in liquid vehicle that is predominantly water.  
   
   
       4 . A composition as in  claim 1 , wherein the surface dielectric constant is from 2.3 to 2.8.  
   
   
       5 - 9 . (canceled)  
   
   
       10 . A composition as in  claim 1 , said composition being colorless.  
   
   
       11 . A composition as in  claim 1;  wherein the liquid vehicle includes a predominant amount of water, from 0 wt % to 45 wt % cosolvent, and from 0 wt % to 5 wt % vehicle surfactant.  
   
   
       12 . A composition as in  claim 1 , further comprising an ultraviolet absorber.  
   
   
       13 . (canceled)  
   
   
       14 . A composition as in  claim 1 , said composition being jettable from an ink-jet pen.  
   
   
       15 - 26 . (canceled)  
   
   
       27 . A system for producing waterfast and humidfast images, comprising: 
 (a) a media substrate;    (b) an ink-jet ink including a colorant, said ink-jet ink configured for being printed on the media substrate; and    (c) a coating composition including latex particulates dispersed in a liquid vehicle, said coating composition configured for overcoating the ink-jet ink on the media substrate, said latex particulates having surfactant associated with a surface of the latex particulates.    
   
   
       28 . A system as in  claim 27 , wherein the surfactant is a reactive surfactant covalently attached to the surface of the latex particulates.  
   
   
       29 . A system as in  claim 27 , wherein the latex particulates have a surface dielectric constant from 2.0 to 3.0 at room temperature, and a bulk density from 0.1 g/cm 3  less to 0.1 g/cm 3  greater than the vehicle density.  
   
   
       30 . A system as in  claim 29 , wherein the surfactant is a non-reactive surfactant adsorbed on the surface of the latex particulates.  
   
   
       31 . A system as in  claim 27 , wherein the latex particulates are present in the liquid vehicle at from 0.1 wt % to 20 wt % solids.  
   
   
       32 . A system as in  claim 27 , wherein the colorant is a dye.  
   
   
       33 . A system as in  claim 27 , wherein the colorant is a pigment.  
   
   
       34 . A system as in  claim 29 , wherein the surface dielectric constant is from 2.3 to 2.8.  
   
   
       35 . A system as in  claim 27 , wherein a crosslinking agent is polymerized in the latex particulates at from 0.1 wt % to 5 wt %.  
   
   
       36 . A system as in  claim 27 , wherein the latex particulates have a glass transition temperature from 0° C. to 50° C.  
   
   
       37 . A system as in  claim 27 , wherein the latex particulates include at least one ring-containing monomer.  
   
   
       38 . A system as in  claim 27 , said coating composition being substantially colorless.  
   
   
       39 . A system as in  claim 27 , wherein the liquid vehicle includes a predominant amount of water, from 0 wt % to 45 wt % cosolvent, and from 0 wt % to 5 wt % vehicle surfactant.  
   
   
       40 . A system as in  claim 27 , wherein the media substrate is a porous media substrate.  
   
   
       41 . A system as in  claim 27 , wherein the coating composition is configured to be printed at a greater drop weight that the ink-jet ink.  
   
   
       42 . A method for producing waterfast and humidfast images, comprising: 
 (a) jetting an ink-jet ink including a colorant onto a media substrate; and    (b) jetting a coating composition including latex particulates dispersed in a liquid vehicle over the ink-jet ink previously jetted on the substrate, said latex particulates having surfactant associated with a surface of the latex particulates.    
   
   
       43 . A method as in  claim 42 , wherein the surfactant is a reactive surfactant covalently attached to the surface of the latex particulates.  
   
   
       44 . A method as in  claim 42 , wherein the latex particulates have a surface dielectric constant from 2.0 to 3.0 at room temperature, and a bulk density from 0.1 g/cm 3  less to 0.1 g/cm 3  greater than the vehicle density.  
   
   
       45 . A method as in  claim 44 , wherein the surfactant is a non-reactive surfactant adsorbed on the surface of the latex particulates.  
   
   
       46 . A method as in  claim 42 , wherein the latex particulates are present in the liquid vehicle at from 0.1 wt % to 20 wt % solids.  
   
   
       47 . A method as in  claim 42 , wherein a crosslinking agent is polymerized in the latex particulates at from 0.1 wt % to 5 wt %, and wherein the latex particulates have a glass transition temperature from 0° C. to 50° C.  
   
   
       48 . A method as in  claim 42 , said coating composition being substantially colorless.  
   
   
       49 . A method as in  claim 42 , wherein the media substrate is a porous media substrate.