US4052232A
Expired / Lapsed
US
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Phosphating process
Assignee: Imperial Chemical Industries Ltd
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Filing: 1976-06-18
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Granted: 1977-10-04
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Expires: 1996-06-18
Abstract
Abstract Low molecular weight water soluble polymers (molecular weight less than 5 × 10 5 ) which comprise monomer moieties selected from acrylic acid, methacrylic acid, acrylamide and methacrylamide, when present in acid metal phosphating solutions modify the physical form of sludge produced. Process efficiency is improved.
Inventors
- 👤 Michael Brock
- 👤 Brian Alfred Cooke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:29
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/07; C23C22/08
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
65 words
A process of applying a phosphate coating to a ferrous metal substrate by treating the substrate with an acidic zinc phosphate solution and a depolarizing oxidant in the presence of 1 - 100 parts of a water soluble polymer per million parts of the phosphate solution, wherein the polymer is a polyacrylic acid or a polyacrylamide of molecular weight between 150 and 5×10 5 .
Claim 2
Dependent Claim
65 words
A process of applying a phosphate coating to a ferrous metal substrate by treating the substrate with an acidic zinc phosphate solution and a depolarizing oxidant in the presence of 1 - 100 parts of a water soluble polymer per million parts of the phosphate solution, wherein the polymer is a polyacrylic acid or a polyacrylamide of molecular weight between 150 and 5×10 5 .
Claim 3
Dependent Claim
25 words
A process according to claim 1 wherein there is present 5 to 50 parts of water soluble polymer per million parts of the phosphate solution.
Claim 4
Dependent Claim
20 words
A process according to claim 1 wherein the molecular weight of the polymer is in the range 1,000 to 50,000.
Claim 5
Dependent Claim
22 words
A process according to claim 1 wherein the substrate is treated by spraying with or by immersion in the acid phosphate solution.
Claim 6
Dependent Claim
40 words
An acidic zinc phosphate solution containing a depolarizing oxidant and 1-100 parts of water soluble polymer, per million parts of phosphate solution, said polymer being a polyacrylic acid or a polyacrylamide of molecular weight between 150 and 5×10 5 .
Claim 7
Dependent Claim
40 words
An acidic zinc phosphate solution containing a depolarizing oxidant and 1-100 parts of water soluble polymer, per million parts of phosphate solution, said polymer being a polyacrylic acid or a polyacrylamide of molecular weight between 150 and 5×10 5 .
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) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |