Inorganic/organic insulating coating for nonoriented electrical steel
US5955201A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1997 |
| Grant date | Sep 21, 1999 |
| Priority date | — |
| Expiry date | Dec 19, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31833
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention relates to a nonoriented electrical steel sheet coated on both surfaces with a cured insulative coating for providing a high level of surface resistivity to minimize interlaminar power losses. The cured insulative coating on the steel sheet includes, based upon 100 parts by dry weight, 20-60 parts of aluminum phosphate, 20-70 parts of at least one inorganic particulate silicate and 10-25 parts of an acrylic resin. The cured coating is formed from an acid aqueous suspension that may include up to 1 part by weight of a water-soluble organic solvent per each part of the resin. The aqueous suspension has a pH of about 2-2.5, a silicate particle size of 0.3-60 .mu.m, a resin particle size of less than 1 .mu.m, less than about 0.5 wt. % unreacted phosphoric acid and a specific gravity of about 1.0-1.3. The silicate may be one or more from the group consisting of aluminum silicate, aluminum potassium silicate and magnesium silicate. After curing, the coating has a thickness on each sheet surface of 0.5-8 .mu.m. The insulative coated nonoriented electrical steels may be used to minimize power losses in laminated magnetic cores of motors, generators, transformers, and …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.