US3890164A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface treatment of tinplate for improving sulfur resistance
Assignee: JFE Steel Corp
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Filing: 1973-07-09
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Granted: 1975-06-17
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Expires: 1993-07-09
Abstract
Abstract Surface treatment of tin-plated steel for food can and the like for improving sulfur resistance, by applying chromate treatment on the plated tin, immediately after electroplating thereof, in an aqueous solution containing 6-valent chromium ions, and then heating at a temperature above 100*C.
Inventors
- 👤 Shunichi Harada
- 👤 Takahisa Yoshihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 01:02
CPC Classifications
C; C25; C25D; C25D5/00; C25D5/48; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/24
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
74 words
Surface treatment of tin-plated steel for a food can and the like for improving sulfur resistance and producing a bright finish, comprising plating tin on the surface of steel, applying cathodic electrolytic chromate treatment to the tin thus plated by using an aqueous acid solution containing 6-valent chromium ions and whose pH value is 3 to 6 prior to reflowing and treating the chromate treated tin-plated steel at a temperature from 280* to 350*C.
Claim 2
Dependent Claim
74 words
Surface treatment of tin-plated steel for a food can and the like for improving sulfur resistance and producing a bright finish, comprising plating tin on the surface of steel, applying cathodic electrolytic chromate treatment to the tin thus plated by using an aqueous acid solution containing 6-valent chromium ions and whose pH value is 3 to 6 prior to reflowing and treating the chromate treated tin-plated steel at a temperature from 280* to 350*C.
Claim 3
Dependent Claim
59 words
Surface treatment for tin-plated steel for a food can and the like for improving sulfur resistance and producing a bright finish, comprising plating tin on the surface of steel, sujecting the thus plated tin to a dip chromate treatment with chromic acid prior to reflowing and heating the chromate treated tin-plated steel at a temperature from 280* to 350*C.
Claim 4
Dependent Claim
59 words
Surface treatment for tin-plated steel for a food can and the like for improving sulfur resistance and producing a bright finish, comprising plating tin on the surface of steel, sujecting the thus plated tin to a dip chromate treatment with chromic acid prior to reflowing and heating the chromate treated tin-plated steel at a temperature from 280* to 350*C.
Claim 5
Dependent Claim
30 words
Surface treatment of tin-plated steel according to claim 1, wherein said heating of the chromate treated tin-plated steel is effected at temperatures from the melting point of tin to 350*C.
Claim 6
Dependent Claim
24 words
SURFACE TREATMENT OF TIN-PLATED STEEL ACCORDING TO CLAIM 1 FURTHER COMPRISING APPLYING AN AQUEOUS ACID SOLUTION CONTAINING 6-VALENT CHRONIUM IONS AFTER THE HEATING STEP.
Claim 7
Dependent Claim
27 words
Surface treatment of tin-plated steel according to claim 2 further comprising applying an aqueous acid solution containing 6-valent chromium ions to the tin after the heating step.
References Cited (Backward Citations)
US2503217A
Cited
US2820747A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |