Claims
- 1. A method of making a variable voltage protection material comprising conductive particles, insulating particles and a polymeric binder comprising the steps of:
- forming a mixture comprising conductive particles and insulating particles in a light organic solvent;
- mixing said mixture in the absence of the polymeric binder to disperse the insulating particles in the conductive particles;
- evaporating substantially all of the solvent to form a cake of the conductive particles and insulating particles;
- grinding the cake to produce a prepared mixture of conductive particles and insulating particles in the absence of the polymeric binder; and
- mixing the resultant prepared mixture of conductive particles and insulating particles with a polymeric binder to form a variable voltage protection material.
- 2. A method according to claim 1 comprising:
- sieving the mixture of particles and solvent before evaporating the solvent.
- 3. A method according to claim 1 wherein said mixture further comprises semiconductor conductive particles.
- 4. A method according to claim 1 comprising:
- forming a separate mixture comprising aluminum oxide particles and insulative particles in a light organic solvent;
- mixing said mixture to disperse the insulating particles in the aluminum oxide particles;
- evaporating substantially all of the solvent to form a cake of the aluminum oxide particles and insulating particles;
- grinding the cake; and
- mixing the resultant mixture of conductive particles and insulating particles and the resultant mixture of aluminum oxide particles and insulating particles with a polymeric binder to form a variable voltage protection material.
- 5. A method according to claim 1 comprising:
- dispersing the conductive particles in a light organic solvent;
- sieving the dispersed conductive particles and solvent; and
- adding insulating particles to the resulting mixture of conductive particles and solvent.
- 6. A method according to claim 4 comprising:
- dispersing the aluminum oxide particles in a light organic solvent;
- sieving the dispersed aluminum oxide particles and solvent; and
- adding insulating particles to the resulting mixture of aluminum oxide particles and solvent.
Parent Case Info
This application is a continuation of application Ser. No. 08/275,154, filed Jul. 14 1994 now abandoned.
US Referenced Citations (24)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0 220 003 |
Apr 1987 |
EPX |
0 487 920 |
Mar 1992 |
EPX |
57-063365 |
Apr 1982 |
JPX |
63-137972 |
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JPX |
Non-Patent Literature Citations (1)
Entry |
Materials Technology; "Technological Advances"; vol. 9, No. 3/4; Feb./Mar. 1994. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
275154 |
Jul 1994 |
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