Claims
- 1. A method of manufacturing a zinc oxide varistor comprising the steps of:applying an additive including an aqueous binder solution and a metal oxide on an outer surface of a molded material containing a zinc oxide as a principal ingredient; sintering the molded material to obtain a sintered body; and heating the sintered body in a temperature range of not less than 500° C. and not more than 600° C., wherein the aqueous binder solution contains one selected from the group consisting of polyvinyl alcohol, methyl cellulose, hydroxypropyl cellulose, and water-soluble acryl by 2.5 to 15% by weight, and the metal oxide is added in the aqueous binder solution so that a solid matter ratio is 15 to 60% by weight.
- 2. A method of manufacturing a zinc oxide varistor comprising the steps of:applying an additive including an aqueous binder solution and a metal oxide on an outer surface of a molded material containing a zinc oxide as a principal ingredient; sintering the molded material to obtain a sintered body; and heating the sintered body in a temperature range of not less than 500° C. and not more than 600° ° C., wherein the metal oxide comprises iron of 1 to 40 molar % in terms of Fe2O3, bismuth of 20 molar % or less in terms of Bi2O3, and the balance of SiO2.
- 3. The method of manufacturing a zinc oxide varistor of claim 2,wherein the step of sintering the molded material includes sintering the molded material in a temperature range of 950 to 1300° C.
- 4. The method of manufacturing a zinc oxide varistor of claim 2,wherein the density of the molded material is in a range of 3.15 to 3.40 g/cm3.
- 5. The method of manufacturing a zinc oxide varistor of claim 2,wherein the additive is applied in any one of a dip coating method, a spray coating method, a transfer coating method, and a screen printing method.
- 6. The method of manufacturing a zinc oxide varistor of claim 2,wherein the additive further includes at least one of a manganese oxide, an aluminum oxide and a boron oxide.
- 7. A method of manufacturing a zinc oxide varistor comprising the steps of:applying an additive including an aqueous binder solution and a metal oxide on an outer surface of a molded material containing a zinc oxide as a principal ingredient; sintering the molded material to obtain a sintered body; and heating the sintered body in a temperature range of not less than 500° C. and not more than 600° C., said method further comprising the step of calcining the molded material until its shrinkage rate is 10% or less, before applying the additive, wherein the aqueous binder solution contains one selected from the group consisting of polyvinyl alcohol, methyl cellulose, hydroxypropyl cellulose, and water-soluble acryl by 2.5 to 15% by weight, and the metal oxide is added in the aqueous binder solution so that a solid matter ratio is 15 to 60% by weight.
- 8. A method of manufacturing a zinc oxide varistor comprising the steps of:applying an additive including an aqueous binder solution and a metal oxide on an outer surface of a molded material containing a zinc oxide as a principal ingredient; sintering the molded material to obtain a sintered body; and heating the sintered body in a temperature range of not less than 500° C. and not more than 600° ° C., said method further comprising the step of calcining the molded material until its shrinkage rate is 10% or less, before applying the additive, wherein the metal oxide comprises iron of 1 to 40 molar % in terms of Fe2O3, bismuth of 20 molar % or less in terms of Bi2O3, and the balance of SiO2.
- 9. The method of manufacturing a zinc oxide varistor of claim 8,wherein the step of sintering the molded material includes sintering the molded material in a temperature range of 950 to 1300° C.
- 10. The method of manufacturing a zinc oxide varistor of claim 8,wherein the density of the molded material is in a range of 3.15 to 3.40 g/cm3.
- 11. The method of manufacturing a zinc oxide varistor of claim 8,wherein the additive is applied in any one of a dip coating method, a spray coating method, a transfer coating method, and a screen printing method.
- 12. The method of manufacturing a zinc oxide varistor of claim 8,wherein the additive further includes at least one of a manganese oxide, an aluminum oxide and a boron oxide.
Priority Claims (1)
Number |
Date |
Country |
Kind |
7-109256 |
May 1995 |
JP |
|
Parent Case Info
This is a divisional application of Ser. No. 08/945,753, filed Feb. 20, 1998, now U.S. Pat. No. 5,980,788.
US Referenced Citations (8)
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