Overvoltage protection materials and process for preparing same

Abstract

The invention provides a process for preparing an overvoltage protection material comprising: (i) preparing a mixture comprising a polymer binder precursor and a conductive material; and (ii) heating the mixture to cause reaction of the polymer binder precursor and generate a polymer matrix having conductive material dispersed therein, wherein the polymer binder precursor is chosen such that substantially no solvent is generated during the reaction.

1 - 27 . (canceled)  
   
   
       28 . A process for preparing an overvoltage protection device comprising: 
 (i) depositing a metallic layer on a substrate, and etching the metallic layer in order to provide metallic electrodes separated by gaps;    (ii) preparing a mixture comprising at least one polymer binder precursor and a conductive material, and applying this mixture between and in contact with adjacent electrodes; and    (iii) heating the device to cause reaction of the polymer binder precursor and generate an overvoltage protection material comprising a polymer binder having conductive material dispersed therein;    wherein the polymer binder precursor is chosen such that substantially no solvent is generated during the reaction.    
   
   
       29 . A process according to  claim 28  wherein the mixture comprising a polymer binder precursor and a conductive material is substantially solvent free.  
   
   
       30 . A process according to  claim 28  wherein the polymer binder precursor reacts via an addition polymerisation process.  
   
   
       31 . A process according to  claim 30  wherein the polymer binder formed by the addition polymerisation process is substantially free of voids.  
   
   
       32 . A process according to  claim 28  wherein the overvoltage protection device has a trigger voltage of less than 300V.  
   
   
       33 - 54 . (canceled)