US3966570A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrolytic post-treating method of electrolytically chromate treated or metallic chromium plated steel sheet
Assignee: JFE Engineering Corp
•
Filing: 1974-06-18
•
Granted: 1976-06-29
•
Expires: 1994-06-18
Abstract
Abstract Method of electrolytically post-treating an electrolytically chromate treated or metallic chromium plated steel sheet comprises anodically treating the said electrolytically chromate threated or metallic chromium plated steel sheet in an electrolyte other than an aqueous solution easily dissolving metallic chromium. The anodically treated steel sheet can be treated cathodically in an electrolyte with the said anodically treated steel sheet being employed as the cathode.
Inventors
- 👤 Hidehisa Yamagishi
- 👤 Hiroshi Takano
- 👤 Yoshitaka Kashiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:50
CPC Classifications
C; C25; C25D; C25D5/00; C25D5/48; C25D11/00; C25D11/38; Y; Y10; Y10S; Y10S205/00; Y10S205/916
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
120 words
A method for electrolytically post-treating the surface of an electrolytically chromate treated or metallic chromium plated steel sheet, which comprises anodically treating said sheet, said sheet being employed as an anode, with a quantity of electricity of from at least about 0.2 Coulomb/dm 2 to a quantity insufficient to completely dissolve the metallic chromium layer, and in an electrolyte comprising an aqueous solution containing (a) and (b), below: a. from about 3 to about 40 grams per liter of hexavalent chromium, expressed as chromic acid, and b. from about 5 to about 50 grams per liter of at least one compound selected from the group consisting of an aliphatic and aromatic monobasic, dibasic and polybasic acid and a salt thereof.
Claim 2
Independent Claim
120 words
A method for electrolytically post-treating the surface of an electrolytically chromate treated or metallic chromium plated steel sheet, which comprises anodically treating said sheet, said sheet being employed as an anode, with a quantity of electricity of from at least about 0.2 Coulomb/dm 2 to a quantity insufficient to completely dissolve the metallic chromium layer, and in an electrolyte comprising an aqueous solution containing (a) and (b), below: a. from about 3 to about 40 grams per liter of hexavalent chromium, expressed as chromic acid, and b. from about 5 to about 50 grams per liter of at least one compound selected from the group consisting of an aliphatic and aromatic monobasic, dibasic and polybasic acid and a salt thereof.
Claim 3
Dependent Claim
73 words
The method of claim 1, wherein said anodically treated steel sheet is subsequently treated cathodically, said anodically treated steel sheet being employed as a cathode, with a current density of from about 5 to about 30 A/dm 2 , at an electrolyte temperature of from about 20°C. to about 60°C., for an electrolysis time of from about 1 to about 10 seconds, and in the same electrolyte as that for said anodic treatment.
Claim 4
Dependent Claim
15 words
The method of claim 1, wherein the steel sheet is an electrolytically chromate treated sheet.
Claim 5
Dependent Claim
15 words
The method of claim 1, wherein the steel sheet is a metallic chromium plated sheet.
Claim 6
Dependent Claim
15 words
The method of claim 2, wherein the steel sheet is an electrolytically chromate treated sheet.
Claim 7
Dependent Claim
15 words
The method of claim 2, wherein the steel sheet is a metallic chromium plated sheet.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-29 | 1979-12-29 | 1980-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-29 | 1983-12-29 | 1984-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-29 | 1987-12-29 | 1988-06-29 | $7700.00 | Window Closed / Lapsed |