| 摘要 |
PROBLEM TO BE SOLVED: To provide a PTC resistor for a current limiting element the operation of which can be stabilized, its characteristic changes such as oxidation deterioration can be prevented, and the long-term reliability can be made satisfactory, and a method for manufacturing this. SOLUTION: Lanthanum oxide(La2 O3 ), strontium carbonate(SrCO3 ), and manganese oxide(MnO) is scaled, and slurry mixed and crushed by a wet ball mill is temporarily burnt in air for several hours at a temperature of 1,000 deg.C, and mixed and crushed by the wet ball mill again, and the dried. Afterwards, this is die-molded, and burnt in an oxygen air flow for 10-20 hours at a temperature of 1,200 deg.C, and a pervoskite type Mn system oxide La1-x Srx MnO3 the Sr composition (x) of which ranges from 0.3 to 0.5. |
