US3973998A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rinsing solutions for acid cleaned iron and steel surfaces
Assignee: Celanese Coatings & Specialties Co
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Filing: 1975-05-05
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Granted: 1976-08-10
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Expires: 1995-05-05
Abstract
Abstract Metal surfaces, after being cleaned of rust with an aqueous acid solution, are rinsed with an aqueous solution of a chelating agent and an ammonium or alkali metal silicate. Such rinsed surfaces remain rust free for extended periods of time. When coated with primer and top-coat paints, excellent durability and corrosion resistance are obtained.
Inventors
- 👤 Vijay Jang Datta
- 👤 John David White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:11
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23G; C23G1/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
91 words
The process of acid cleaning of rusty iron and steel, the imrovement which comprises rinsing the acid cleaned steel with an aqueous solution consisting essentially of a chelating agent capable of forming a complex with iron atoms and an ammonium or alkali metal silicate wherein the chelating agent is present in the amount of about 0.25 to about 3 percent by weight and the silicate is present in the amount of about 5 to about 15 percent by weight, said precents being based on the total weight of the aqueous solution.
Claim 2
Dependent Claim
91 words
The process of acid cleaning of rusty iron and steel, the imrovement which comprises rinsing the acid cleaned steel with an aqueous solution consisting essentially of a chelating agent capable of forming a complex with iron atoms and an ammonium or alkali metal silicate wherein the chelating agent is present in the amount of about 0.25 to about 3 percent by weight and the silicate is present in the amount of about 5 to about 15 percent by weight, said precents being based on the total weight of the aqueous solution.
Claim 3
Dependent Claim
32 words
The process of claim 1 wherein the chelating agent is present in the amount of about 1 to about 2 percent by weight based on the total weight of the aqueous solution.
Claim 4
Dependent Claim
31 words
The process of claim 1 wherein the silicate is present in the amount of about 6 to about 9 percent by weight based on the total weight of the aqueous solution.
Claim 5
Dependent Claim
18 words
The process of claim 1 wherein the chelating agent is the tetrasodium salt of ethylene diamine tetraacetic acid.
Claim 6
Dependent Claim
12 words
The process of claim 1 wherein the chelating agent is triethanol amine.
Claim 7
Dependent Claim
13 words
The process of claim 1 wherein the chelating agent is N,N,N',N'-tetrakis (2-hydroxypropyl)ethylene diamine.
Claim 8
Dependent Claim
12 words
The process of claim 1 wherein the silicate is a sodium silicate.
Claim 9
Dependent Claim
12 words
The process of claim 1 wherein the silicate is a lithium silicate.
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) | 1979-08-10 | 1980-02-09 | 1980-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-10 | 1984-02-09 | 1984-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-10 | 1988-02-09 | 1988-08-10 | $7700.00 | Window Closed / Lapsed |