Organic positive temperature coefficient thermistor and making method

• US 6,558,579 B2
• Filed: 04/05/2001
• Issued: 05/06/2003
• Est. Priority Date: 10/01/1999
• Status: Expired due to Fees

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Handa, Tokuhiko, Yoshinari, Yukie
• Primary Examiner(s): Gupta, Yogendra N.
• Assistant Examiner(s): Hamlin, Derrick G.
• Application Number:
  US09/825,828
• Publication Number:
  US 20020145130A1
• Time in Patent Office: 761 Days
• Field of Search: 252/500, 252/510, 252/511, 252/512, 252/513, 252/518.1, 219/541, 219/546, 219/547, 219/553, 264/105, 264/104, 264/234, 264/347
• US Class Current: 252/511
• CPC Class Codes: H01C 17/06586 composed of organic material
• CPC Class Codes: H01C 7/027 consisting of conducting or semi-conducting material dispersed in a non-conductive organic material

Abstract

The invention aims to provide an organic PTC thermistor having a lower operating temperature than prior art organic PTC thermistors and exhibiting improved characteristics. The object is attained by an organic PTC thermistor comprising a polymer synthesized in the presence of a metallocene catalyst and conductive particles having spiky protuberances.

Claims

1. An organic positive temperature coefficient thermistor comprising:

a polymer synthesized in the presence of a metallocene catalyst; and

conductive particles having spiky protuberances.

2. The organic positive temperature coefficient thermistor of claim 1, wherein said polymer synthesized in the presence of a metallocene catalyst is a linear low-density polyethylene.

3. The organic positive temperature coefficient thermistor of claim 1, wherein said conductive particles having spiky protuberances are interconnected in chain-like network.

4. The organic positive temperature coefficient thermistor of claim 1, further comprising a low molecular weight organic compound.

5. A method for preparing an organic positive temperature coefficient thermistor, comprising the steps of

synthesizing a polymer in the presence of a metallocene catalyst,

admixing the polymer with conductive particles having spiky protuberances, and

treating the mixture with a silane coupling agent.