Patent US2443470A successfully refreshed from Google Patents.
Patent US4831977A successfully refreshed from Google Patents.
US4831977A
Expired / Lapsed
US
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Pistons with wear resistant solid film lubricant coatings
Assignee: Ethyl Corp
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Filing: 1987-07-17
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Granted: 1989-05-23
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Expires: 2007-07-17
Abstract
Abstract Surfaces which have substantially continuous frictional contact, eg. reciprocating engine parts, are coated with a solid film lubricant having excellent wear characteristics and adhesion. The parts in question may be pistons, and the area to which the wear resistant solid lubricant film is bonded is the piston skirt -- i.e., all or a portion of the area below the piston rings. The lubricant is composed of a polyimide derived from 2,2-bis[4-(4-amino- phenoxy)phenyl]hexafluoropropane ("4-BDAF") and an aromatic tetracarboxylic acid (or dianhydride or ester thereof) containing fluorinated carbon.
Inventors
- 👤 J. Kenneth Presswood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:23
CPC Classifications
F; F16; F16J; F16J1/00; F16J1/02; C; C10; C10M; C10M103/00; C10M103/02; C10M107/00; C10M107/40; C10M107/44; C10M111/00; C10M111/04; F16N; F16N15/00; B; B29; B29K; B29K2105/00; B29K2105/25; B29K2105/253; B29K2995/00; B29K2995/0037; B29K2995/0072; B29K2995/0073; C10M2201/00; C10M2201/04; C10M2201/041; C10M2201/0413; C10M2201/042; C10M2201/0423; C10M2201/06; C10M2201/061; C10M2201/16; C10M2201/18; C10M2217/00; C10M2217/04; C10M2217/0403; C10M2217/041; C10M2217/0415; C10M2217/042; C10M2217/0425; C10M2217/043; C10M2217/0435; C10M2217/044; C10M2217/0443; C10M2217/045; C10M2217/0453; C10M2217/046; C10M2217/0465; C10N; C10N2040/00; C10N2040/02; C10N2050/00; C10N2050/015; C10N2050/02; F05; F05C; F05C2203/00; F05C2203/08; F05C2203/0865; F05C2203/0882
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
55 words
A piston having bonded to its skirt portion a wear resistant solid film lubricant consisting essentially of (a) fluorinated carbon in a matrix of (b) a polyimide derived from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and at least one of the following aromatic tetracarboxylic acids or a dianhydride or ester thereof: pyromellitic acid benzophenonetetracarboxylic acid 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane oxydiphthalic acid biphenyltetracarboxylic acid.
Claim 2
Dependent Claim
55 words
A piston having bonded to its skirt portion a wear resistant solid film lubricant consisting essentially of (a) fluorinated carbon in a matrix of (b) a polyimide derived from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and at least one of the following aromatic tetracarboxylic acids or a dianhydride or ester thereof: pyromellitic acid benzophenonetetracarboxylic acid 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane oxydiphthalic acid biphenyltetracarboxylic acid.
Claim 3
Dependent Claim
26 words
The article of claim 1 wherein the aromatic tetracarboxylic acid component of the polyimide is based on pyromellitic acid or its dianhydride or an ester thereof.
Claim 4
Dependent Claim
26 words
The article of claim 1 wherein the aromatic tetracarboxylic acid component of the polyimide is based on benzophenonetetracarboxylic acid or its dianhydride or an ester thereof.
Claim 5
Dependent Claim
24 words
The article of claim 1 wherein the aromatic tetracarboxylic acid component of the polyimide is based on the dianhydride of the aromatic tetracarboxylic acid.
Claim 6
Dependent Claim
12 words
The article of claim 1 wherein the piston is an aluminum piston.
Claim 7
Dependent Claim
89 words
In an engine comprising at least one cylinder having a piston reciprocatably disposed therein and means for applying liquid lubricating oil to surfaces of each such cylinder and piston, the improvement in which each such piston has bonded to its skirt portion a wear resistant solid film lubricant consisting essentially of (a) fluorinated carbon in a matrix of (b) a polyimide derived from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and at least one of the following aromatic tetracarboxylic acids or a dianhydride or ester thereof: pyromellitic acid benzophenonetetracarboxylic acid 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane oxydiphthalic acid biphenyltetracarboxylic acid.
Claim 8
Dependent Claim
89 words
In an engine comprising at least one cylinder having a piston reciprocatably disposed therein and means for applying liquid lubricating oil to surfaces of each such cylinder and piston, the improvement in which each such piston has bonded to its skirt portion a wear resistant solid film lubricant consisting essentially of (a) fluorinated carbon in a matrix of (b) a polyimide derived from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and at least one of the following aromatic tetracarboxylic acids or a dianhydride or ester thereof: pyromellitic acid benzophenonetetracarboxylic acid 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane oxydiphthalic acid biphenyltetracarboxylic acid.
Claim 9
Dependent Claim
26 words
The improvement of claim 6 wherein the aromatic tetracarboxylic acid component of the polyimide is based on pyromellitic acid or its dianhydride or an ester thereof.
Claim 10
Dependent Claim
26 words
The improvement of claim 6 wherein the aromatic tetracarboxylic acid component of the polyimide is based on benzophenonetetracarboxylic acid or its dianhydride or an ester thereof.
Claim 11
Dependent Claim
24 words
The improvement of claim 6 wherein the aromatic tetracarboxylic acid component of the polyimide is based on the dianhydride of the aromatic tetracarboxylic acid.
Claim 12
Dependent Claim
13 words
The improvement of claim 6 wherein each such piston is an aluminum piston.
Claim 13
Dependent Claim
81 words
In producing a coated piston, the improvement which comprises applying to the skirt portion thereof a coating consisting essentially of a dispersion of (a) fluorinated carbon in a solution of (b) a polyamic acid derived from 2,2-bis[4-(4-aminophenoxy)-phenyl]hexafluoropropane and at least one of the following aromatic tetracarboxylic acids or a dianhydride or ester thereof: pyromellitic acid benzophenonetetracarboxylic acid 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane oxydiphthalic acid biphenyltetracarboxylic acid; and applying sufficient heat to cure the coating such that the polyamic acid polymer is converted into polyimide polymer.
Claim 14
Dependent Claim
81 words
In producing a coated piston, the improvement which comprises applying to the skirt portion thereof a coating consisting essentially of a dispersion of (a) fluorinated carbon in a solution of (b) a polyamic acid derived from 2,2-bis[4-(4-aminophenoxy)-phenyl]hexafluoropropane and at least one of the following aromatic tetracarboxylic acids or a dianhydride or ester thereof: pyromellitic acid benzophenonetetracarboxylic acid 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane oxydiphthalic acid biphenyltetracarboxylic acid; and applying sufficient heat to cure the coating such that the polyamic acid polymer is converted into polyimide polymer.
Claim 15
Dependent Claim
27 words
The improvement of claim 11 wherein the aromatic tetracarboxylic acid component of the polyamic acid is based on pyromellitic acid or its dianhydride or an ester thereof.
Claim 16
Dependent Claim
27 words
The improvement of claim 11 wherein the aromatic tetracarboxylic acid component of the polyamic acid is based on benzophenonetetracarboxylic acid or its dianhydride or an ester thereof.
Claim 17
Dependent Claim
25 words
The improvement of claim 11 wherein the aromatic tetracarboxylic acid component of the polyamic acid is based on the dianhydride of the aromatic tetracarboxylic acid.
Claim 18
Dependent Claim
12 words
The improvement of claim 11 wherein the piston is an aluminum piston.
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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) | 1992-05-22 | 1992-11-21 | 1993-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-22 | 1996-11-21 | 1997-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-22 | 2000-11-21 | 2001-05-23 | $7700.00 | Window Closed / Lapsed |