Thermosensitive recording material

Abstract

A thermosensitive recording material comprising a support; an insulating layer that includes a porous polymeric pigment; and an image-forming layer.

What is claimed is: 
     
         1 . A thermosensitive recording material comprising:
 (i) a first layer, where said first layer is adapted to provide imaging when exposed to heat; and   (ii) a second layer including porous hollow particles and a binder, where the porous hollow particles have a void volume fraction of at least 40%.   
     
     
         2 . The thermosensitive recording material of  claim 1 , where the porous hollow particles have a void volume fraction of from about 45% to about 83%. 
     
     
         3 . The thermosensitive recording material of  claim 2 , where the porous hollow particles have a void volume fraction of from about 55% to about 77% 
     
     
         4 . The thermosensitive recording material of  claim 2 , where the porous hollow particles have a pore surface area of at least 1%. 
     
     
         5 . The thermosensitive recording material of  claim 4 , where the porous hollow particles have a pore surface area of at least 3%. 
     
     
         6 . The thermosensitive recording material of  claim 5 , where porous hollow particles have a pore surface area of at least 5%. 
     
     
         7 . The thermosensitive recording material of  claim 4 , where the porous hollow particles have a pore surface area of from about 3% to about 45%. 
     
     
         8 . The thermosensitive recording material of  claim 1 , where the second layer includes from about 20 to about 90 percent by weight porous hollow particles, on a dry weight basis, relative to the weight of the layer. 
     
     
         9 . The thermosensitive recording material of  claim 8 , where the second layer includes from about 5 to about 50 percent by weight binder, on a dry weight basis, relative to the weight of the layer. 
     
     
         10 . The thermosensitive recording material of  claim 1 , where the binder is selected from the group consisting of synthetic latexes, starch, soy, casein, albumin, polyvinyl alcohol, carboxymethyl cellulose, hydroxymethyl cellulose, polyacrylate salt, and mixtures thereof. 
     
     
         11 . The thermosensitive recording material of  claim 1 , where the second layer further includes a pigment selected from the group consisting of kaolin, talc, calcined clay, structured clay, ground calcium carbonate, precipitated calcium carbonate, titanium dioxide, aluminum trihydrate, satin white, silica, zinc oxide, barium sulfate, and mixtures thereof. 
     
     
         12 . The thermosensitive recording material of  claim 1 , where the porous hollow particles are prepared by treating a core-shell polymeric particle under conditions sufficient to form the porous hollow particles, where the core-shell polymeric particles have acrylate units in the shell and acrylate units in the core. 
     
     
         13 . The thermosensitive recording material of  claim 12 , where the core includes at least 10 wt % acrylate units. 
     
     
         14 . The thermosensitive recording material of  claim 12 , where the shell includes at least 5 wt % acrylate units. 
     
     
         15 . The thermosensitive recording material of  claim 12 , where the acrylate units derive from monomer selected from the group consisting of methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, 2-ethyl hexyl acrylate, octyl acrylate, iso-octyl acrylate, n-decyl acrylate, iso-decyl acrylate, tertbutyl acrylate, and 2-hydroxyethyl acrylate. 
     
     
         16 . The thermosensitive recording material of  claim 15 , where the acrylate units derive from monomer selected from the group consisting of ethyl acrylate, butyl acrylate, and hexa acrylate.