US4424079A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rust removal process
Assignee: ISP Investments LLC
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Filing: 1982-03-31
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Granted: 1984-01-03
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Expires: 2002-03-31
Abstract
Abstract Rust is removed from metal surfaces by applying a coating of an aqueous solution of vinylpyrrolidone/maleic acid copolymer. The rust becomes incorporated into the coating during drying and the coating detaches itself from the metal surface for easy removal.
Inventors
- 👤 Eugene S. Barabas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:02
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/02; C23G1/025
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
66 words
Process for removing rust from a rusty metal surface which comprises: (a) applying to said rusty surface a layer of rust removal coating composition consisting essentially of an aqueous solution of a copolymer of N-vinyl-2-pyrrolidone and maleic acid; and (b) allowing said layer of coating composition to dry whereby rust becomes incorporated into said layer and the layer containing the rust detaches itself from the surface.
Claim 2
Dependent Claim
66 words
Process for removing rust from a rusty metal surface which comprises: (a) applying to said rusty surface a layer of rust removal coating composition consisting essentially of an aqueous solution of a copolymer of N-vinyl-2-pyrrolidone and maleic acid; and (b) allowing said layer of coating composition to dry whereby rust becomes incorporated into said layer and the layer containing the rust detaches itself from the surface.
Claim 3
Dependent Claim
29 words
Process according to claim 1 wherein the coating composition contains between about 5 and about 60 wt % copolymer and between about 40 and about 95 wt % water.
Claim 4
Dependent Claim
19 words
Process according to claim 1 wherein the coating composition has a viscosity between about 50 and about 250,000 cps.
Claim 5
Dependent Claim
26 words
Process according to claim 2 wherein the coating composition is applied to the rusty surface in a layer between about 0.01 and about 20 mm thick.
Claim 6
Dependent Claim
24 words
Process according to claim 4 wherein the layer of applied coating composition is allowed to dry for between about 0.5 and about 8 hours.
Claim 7
Dependent Claim
107 words
Process according to claim 1 wherein: (a) the coating composition consists essentially of between about 5 and about 60 wt % of said copolymer and between about 40 and about 95 wt % water; (b) the coating composition is applied to the rusty surface to form a layer between about 0.01 and about 20 mm thick; (c) The coating composition has a viscosity between about 50 and about 250,000 cps; (d) the applied coating composition is allowed to dry for between about 0.5 and about 8 hours whereby the rust becomes incorporated into the layer of coating composition and the layer becomes detached from the metal surface.
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) | 1987-01-02 | 1987-07-04 | 1988-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-02 | 1991-07-04 | 1992-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-02 | 1995-07-04 | 1996-01-03 | $7700.00 | Window Closed / Lapsed |