US3907610A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of forming colorless chromate film on Al, Al-alloy or Al-coated steel
Assignee: JFE Engineering Corp
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Filing: 1974-04-12
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Granted: 1975-09-23
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Expires: 1994-04-12
Abstract
Abstract Colorless chromate film having good corrosion resistance and adhesive property on Aluminium, Aluminium alloy or Aluminiumcoated steel when these materials are subjected to a pretreatment stage wherein the material is rinsed with hot water after de-oiling and dried while the water film still lying on the surface is wiped by drawing rolls, a treatment stage wherein the material is processed with an aqueous solution of about 2 to 10g/l of CrO3, 0.05 to 1g/l Cr 3, 0.2 to 5g/l F , 0.01 to 5g/l of Ferricyanide and/or Ferrocyanide, 0.01 to 1g/l Al 3 and a post treatment stage wherein the material is processed with an aqueous solution containing water soluble copolymer of itaconic acid and acrylonitrile.
Inventors
- 👤 Hidehisa Yamagishi
- 👤 Hirokuni Mizuno
- 👤 Yoshitaka Kashiyama
- 👤 Yasuhiro Toyoda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:51
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/34; C23C22/37
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
105 words
IN THE CHEMICAL PROCESS FOR TREATING A WORKPIECE OF ALUMINUM, ALUMINUM ALLOY OR ALUMINUM COATED STEEL TO FORM A COLORLESS CHROMATE FILM THEREON, THE IMPROVEMENT THEREIN WHEREIN THE WORKPIECE IS SUBJECTED TO A PRE-TREATMENT COMPRISING DEOLING, RINSING WITH HOT WATER, DRYING WITH HOT AIR AND, THEN WIPING THE WATER FILM STILL LYING ON THE SURFACE USING DRAWING ROLLS AND DRYING TO OBTAIN A UNIFROM WATER THICKNESS ON THE WORKPIECE, THE TREATING SOLUTION CONSISTING OF THE FOLLOWING COMPOSITION: CRO3 2 TO 10G/L TRIVALENT CHROMIUM: 0.05 TO 1.00G/L FLUORINE ION : 0.2 TO 5G/L ALUMINUM ION : 0.01 TO 1.00G/L FERRICYANIDE AND/OR FERROCYANIDE : 0.01 TO 5.00G/L.
Claim 2
Dependent Claim
105 words
IN THE CHEMICAL PROCESS FOR TREATING A WORKPIECE OF ALUMINUM, ALUMINUM ALLOY OR ALUMINUM COATED STEEL TO FORM A COLORLESS CHROMATE FILM THEREON, THE IMPROVEMENT THEREIN WHEREIN THE WORKPIECE IS SUBJECTED TO A PRE-TREATMENT COMPRISING DEOLING, RINSING WITH HOT WATER, DRYING WITH HOT AIR AND, THEN WIPING THE WATER FILM STILL LYING ON THE SURFACE USING DRAWING ROLLS AND DRYING TO OBTAIN A UNIFROM WATER THICKNESS ON THE WORKPIECE, THE TREATING SOLUTION CONSISTING OF THE FOLLOWING COMPOSITION: CRO3 2 TO 10G/L TRIVALENT CHROMIUM: 0.05 TO 1.00G/L FLUORINE ION : 0.2 TO 5G/L ALUMINUM ION : 0.01 TO 1.00G/L FERRICYANIDE AND/OR FERROCYANIDE : 0.01 TO 5.00G/L.
Claim 3
Dependent Claim
34 words
A process according to claim 1 wherein a post treating following the chemical treating is performed using an aqueous solution of water soluble copolymer of 10 to 50 g/l containing itaconic acid and acrylonitrile.
Claim 4
Dependent Claim
38 words
A process according to claim 1 wherein the concentration of fluorine ion is selected within the range of 0.2 to 2.4 g/l, when the concentration of ferrocyanide and/or ferricyanide is within the range of 0.5 to 5.0 g/l.
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) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |