Patent US4808281A successfully refreshed from Google Patents.
US4808281A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phosphate coating complex metal surfaces
Assignee: Motors Liquidation Co
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Filing: 1988-06-27
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Granted: 1989-02-28
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Expires: 2008-06-27
Abstract
Abstract Anodic formation of amorphous iron phosphate films in a dialkyl hydrogen phosphate electrolytic medium containing hydrogen-rich cation exchange resin particles having a free moisture content between about 9% and about 33% by weight.
Inventors
- 👤 Richard P. Tison
- 👤 Su-Chee S. Wang
- 👤 Dexter D. Snyder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:43
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/36
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
71 words
In the method of forming a substantially amorphous, low friction, wear resistant iron phosphate coating on the surface of an iron-based substrate including the principle step of anodizing said surface in a liquid medium comprising dialkyl hydrogen phosphate, the improvement comprising enhancing the throwing power of said medium by substantially pervading said medium with hydrogen-rich cation exchange resin particles having a free moisture content between about 9% and 33% by weight.
Claim 2
Dependent Claim
71 words
In the method of forming a substantially amorphous, low friction, wear resistant iron phosphate coating on the surface of an iron-based substrate including the principle step of anodizing said surface in a liquid medium comprising dialkyl hydrogen phosphate, the improvement comprising enhancing the throwing power of said medium by substantially pervading said medium with hydrogen-rich cation exchange resin particles having a free moisture content between about 9% and 33% by weight.
Claim 3
Dependent Claim
99 words
In the method of forming a substantially amorphous, low friction, wear resistant iron phosphate coating on the surface of an iron-based substrate including the principle step of anodizing said surface opposite a cathode in a liquid medium comprising dialkyl hydrogen phosphate, the improvement comprising enhancing the throwing power of said medium sufficient to form said coating over a complex said surface having at least one portion proximate said cathode and another portion remote from said cathode by substantially pervading said medium with hydrogen-rich cation exchange resin particles having a free moisture content between about 9% and 33% by weight.
Claim 4
Dependent Claim
99 words
In the method of forming a substantially amorphous, low friction, wear resistant iron phosphate coating on the surface of an iron-based substrate including the principle step of anodizing said surface opposite a cathode in a liquid medium comprising dialkyl hydrogen phosphate, the improvement comprising enhancing the throwing power of said medium sufficient to form said coating over a complex said surface having at least one portion proximate said cathode and another portion remote from said cathode by substantially pervading said medium with hydrogen-rich cation exchange resin particles having a free moisture content between about 9% and 33% by weight.
Claim 5
Dependent Claim
17 words
The method according to claim 2 wherein said dialkyl hydrogen phosphate is mixed with an oil-based lubricant.
Claim 6
Dependent Claim
26 words
The method according to claim 2 wherein the concentration of said dialkyl hydrogen phosphate in said lubricant is between about 50% and about 85% by weight.
Claim 7
Dependent Claim
18 words
The method of claim 4 wherein said dialkyl hydrogen phosphate is between about 65% and 75% by weight.
Claim 8
Dependent Claim
26 words
The method according to claim 3 wherein said dialkyl hydrogen phosphate is selected from the group consisting of dilauryl hydrogen phosphate and mixed dialkyl acid orthophosphate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-28 | 1992-08-29 | 1993-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-28 | 1996-08-29 | 1997-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-28 | 2000-08-29 | 2001-02-28 | $7700.00 | Window Closed / Lapsed |