Front face erasable microcapsule magnetophoretic writing magnet

Abstract

Disclosed herein is a front face erasable microcapsule magnetophoretic display sheet having a support and a solid dispersion layer provided on one surface of the support and composed of microcapsules having an average particle diameter of 50 to 650 μm, in which a liquid dispersion, a white pigment, additives and magnetic particles are encapsulated, and a binder. The magnetic particles include at least two kinds of magnetic particles different in particle diameter from each other. An erasing magnet for front face erasing and a writing magnet for front face erasable microcapsule magnetophoretic display sheet are also disclosed.

1 - 6 . (canceled)  
   
   
       7 . A writing magnet for front face erasable microcapsule magnetophoretic display sheets, wherein the magnet is covered with a metal to control a magnetic field, the magnet comprising: 
 a tip;    a rear end;    a coating around the tip;    a coating around the base, wherein the tip is exposed, and the tip extends above the coating around the tip by between 0 and 1.0 mm.    
   
   
       8 - 36 . (canceled)  
   
   
       37 . The writing magnet of  claim 7 , wherein the tip has a diameter of between 0.2 mm and 2.0 mm, and the coating around the tip plus the tip has a diameter of between 0.2 mm and 8.0 mm.  
   
   
       38 . The writing magnet of  claim 37 , wherein the tip has a diameter between 0.8 mm and 1.2 mm.  
   
   
       39 . The writing magnet of  claim 7 , wherein the tip extends above the coating around the tip by between 0 mm and 0.5 mm.  
   
   
       40 . The writing magnet of  claim 7 , wherein the tip is selected from ferrite, rare earth metal, or Alnico alloy.  
   
   
       41 . The writing magnet of  claim 40 , wherein the coating is selected from brass or iron.  
   
   
       42 . The writing magnet of  claim 41 , wherein the tip has a surface magnetic flux density of at least 750 G.