US4325744A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and composition for cleaning metal surfaces with a film-forming composition
Assignee: United States Department of the Navy
•
Filing: 1980-07-25
•
Granted: 1982-04-20
•
Expires: 2000-07-25
Abstract
Abstract A method of cleaning metal surfaces, particularly irregularly shaped metal surfaces such as exist on a ship, wherein a thick aqueous solution of a water soluble polymer, preferably polyvinylpyrrolidone (PVP), and a chelating agent, is applied to a rusty metal surface as a thick paste, which gradually hardens into an encapsulating film during cleaning. After cleaning is complete, the film and the corrosion products are easily peeled from the clean surface and can be disposed of as solid waste.
Inventors
- 👤 Ramanathan Panayappan
- 👤 David L. Venezky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:55
CPC Classifications
B; B63; B63B; B63B59/00; B63B59/06; C; C11; C11D; C11D3/00; C11D3/16; C11D3/37; C11D3/3746; C11D3/3769; C11D3/3776; C23; C23G; C23G1/00; C23G1/02; C23G1/025
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
119 words
A method of cleaning a metal surface of deposit containing a metal oxide comprising: forming an aqueous solution of a polyvinylpyrrolidone with an average molecular weight from about 10,000 to about 500,000, said solution having a polymer concentration at least sufficient to form a polymeric layer capable of removing said deposit and a chelating agent in an amount from about 1 to about 10 weight percent of said solution; applying said solution onto said metal surface to be cleaned, whereby said solution forms a thick film layer which encapsulates said deposit on the metal surface; allowing said layer to harden while cleaning occurs; and removing the said layer along with corrosion products said deposit from the said metal surface.
Claim 2
Independent Claim
119 words
A method of cleaning a metal surface of deposit containing a metal oxide comprising: forming an aqueous solution of a polyvinylpyrrolidone with an average molecular weight from about 10,000 to about 500,000, said solution having a polymer concentration at least sufficient to form a polymeric layer capable of removing said deposit and a chelating agent in an amount from about 1 to about 10 weight percent of said solution; applying said solution onto said metal surface to be cleaned, whereby said solution forms a thick film layer which encapsulates said deposit on the metal surface; allowing said layer to harden while cleaning occurs; and removing the said layer along with corrosion products said deposit from the said metal surface.
Claim 3
Dependent Claim
15 words
A method as claimed in claim 1 where said metal surface is a ferrous material.
Claim 4
Dependent Claim
30 words
The method of claim 1 wherein said aqueous solution comprises from about 5 to about 30 weight percent polyvinylpyrrolidone and from 1 to 3 weight percent of a chelating agent.
Claim 5
Dependent Claim
26 words
A method as claimed in claim 3 wherein said film is removed from the cleaned metal surface by peeling and subsequently disposed of as solid waste.
Claim 6
Dependent Claim
50 words
The method of claim 3 wherein said chelating agent is selected from the class consisting of ethylenediaminetetraacetic acid (EDTA), its tetrasodium salt, N, N, N', N'-tetrakis (2-hydroxypropyl) -ethylenediamine, triethanolamine, trimethylenediaminetetracetic acid, nitrilobispropionic acid, ethyleneglycol-bis(beta-aminoethyl ether)-N, N-tetracetic acid, pentasodium salt of diethylenetriaminepentaacetate, trisodium salt of N-hydroxyethylethylenediaminetriacetate, iminodiacetic acid, and hydroxyethyl-iminodiacetic acid.
Claim 7
Dependent Claim
12 words
The method of claim 5 wherein said chelating agent is ethylenediaminetetraacetic acid.
Claim 8
Dependent Claim
13 words
The method of claim 5 wherein said metal surface is a ferrous metal.
References Cited (Backward Citations)
US2817606A
Cited
US3079284A
Cited
US3549538A
Cited
US3627686A
Cited
US3708436A
Cited
US3729423A
Cited
US3970594A
Cited
US4085060A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-04-19 | 1985-10-19 | 1986-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-19 | 1989-10-19 | 1990-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-19 | 1993-10-19 | 1994-04-20 | $7700.00 | Window Closed / Lapsed |