Method of producing homogeneous ZnO non-linear powder compositions
US4297250A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 1980 |
| Grant date | Oct 27, 1981 |
| Priority date | — |
| Expiry date | Jan 7, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01C7/112
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of making a ZnO powder composition, which can exhibit non-linear V-I characteristics, comprises the steps of: (1) mixing about 75 mole % to about 98 mole % of small, finely divided, solid ZnO and about 2 mole % to about 25 mole % of at least one small, finely divided, solid additive oxide effective to produce nonlinear characteristics, with an aqueous binder solution comprising an organic, water soluble fugitive binder, to provide a slurry; (2) simultaneously drying, mixing and agglomerating the slurried solids into a mass of larger substantially spherical particles containing the finely divided solids and binder; (3) pressing a mass of the agglomerated particles, to provide a cohesive pressed green body; and then (4) heating the pressed body, first at a temperature rate increase effective to slowly decompose and remove the fugitive binder from the body and then heating at a temperature of between 1,050.degree. C. to about 1,400.degree. C. for a time effective to sinter together the particles of the body, forming ZnO grains; (5) crushing the sintered body to provide finely divided powder particle fragments; (6) passing the particle fragments through a means to measure part…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.