US3985583A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming an insulating coating on an oriented silicon steel sheet
Assignee: JFE Steel Corp
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Filing: 1974-09-19
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Granted: 1976-10-12
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Expires: 1994-09-19
Abstract
Abstract An insulating coating having a high adhesion on an oriented silicon steel sheet, which applies a tension on the surface of the steel sheet and restrains magnetostriction increased when compressive stress is subjected to said oriented silicon steel sheet, is formed by applying a coating aqueous dispersion of 7 - 24% by weight of colloidal silica and 5 - 30% by weight of magnesium phosphate in monobasic magnesium phosphate on the oriented silicon steel sheet and baking the thus treated steel sheet at a temperature of 350° - 900°C. Said coating is more improved by adding 0.01 - 5% by weight of at least one of chromic anhydride, chromates and bichromates to said coating aqueous dispersion.
Inventors
- 👤 Hiroshi Shimanaka
- 👤 Toshio Ichida
- 👤 Shigeru Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:08
CPC Classifications
C; C09; C09D; C09D1/00; C21; C21D; C21D1/00; C21D1/68; C21D1/70; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/24; C23C22/33; C23C22/73; C23C22/74; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/147; H01F1/14766; H01F1/14775; H01F1/14783
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
77 words
A method for forming an insulating coating on an oriented steel sheet having a forsterite coating on its surface, said method comprising; applying a coating of an aqueous dispersion of 7-24% by weight of colloidal silica, 5-30% by weight of magnesium phosphate as monobasic magnesium phosphate, and 0.01-5% by weight of at least one member of the group consisting of chromic anhydride, chromate and bichromate, wherein the compounding ratio of magnesium phosphate to colloidal silica is 20/80-30/70%.
Claim 2
Independent Claim
77 words
A method for forming an insulating coating on an oriented steel sheet having a forsterite coating on its surface, said method comprising; applying a coating of an aqueous dispersion of 7-24% by weight of colloidal silica, 5-30% by weight of magnesium phosphate as monobasic magnesium phosphate, and 0.01-5% by weight of at least one member of the group consisting of chromic anhydride, chromate and bichromate, wherein the compounding ratio of magnesium phosphate to colloidal silica is 20/80-30/70%.
Claim 3
Dependent Claim
19 words
A method as claimed in claim 1, wherein said baking is effected under a neutral or weak oxidizing atmosphere.
Claim 4
Dependent Claim
36 words
A method as claimed in claim 1, wherein said baking is effected in two stages, the first stage being at a temperature of 350°-600° C and the second stage being at a temperature of 800°-900° C.
Claim 5
Dependent Claim
43 words
A coating aqueous dispersion for improving the compression stress property of the magnetostriction of an oriented silicon steel sheet consisting essentially of 7-24% by weight of colloidal silica and 5-30% by weight of magnesium phosphate as magnesium primary phosphate, the remainder being water.
Claim 6
Dependent Claim
43 words
A coating aqueous dispersion for improving the compression stress property of the magnetostriction of an oriented silicon steel sheet consisting essentially of 7-24% by weight of colloidal silica and 5-30% by weight of magnesium phosphate as magnesium primary phosphate, the remainder being water.
References Cited (Backward Citations)
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US3248249A
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US3562011A
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US3615918A
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US3856568A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-10-12 | 1980-04-12 | 1980-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-12 | 1984-04-12 | 1984-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-12 | 1988-04-12 | 1988-10-12 | $7700.00 | Window Closed / Lapsed |