US4831977A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pistons with wear resistant solid film lubricant coatings
Assignee: Ethyl Corp
•
Filing: 1987-07-17
•
Granted: 1989-05-23
•
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 14:10
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.
References Cited (Backward Citations)
US3252905A
Cited
US3380843A
Cited
US3356648A
Cited
US3542735A
Cited
US3671486A
Cited
US3652409A
Cited
US3781205A
Cited
US4012478A
Cited
US3959350A
Cited
US3761453A
Cited
US3792022A
Cited
US3908038A
Cited
US3926913A
Cited
US3951902A
Cited
US4100138A
Cited
US4111906A
Cited
US4196277A
Cited
US4203922A
Cited
US4173700A
Cited
US4283521A
Cited
US4543295A
Cited
US4376710A
Cited
US4528004A
Cited
JPS5891430A
Cited
US4454310A
Cited
JPS58180531A
Cited
JPS58180530A
Cited
US4435839A
Cited
US4532054A
Cited
US4522880A
Cited
US4528216A
Cited
US4477648A
Cited
US4521623A
Cited
US4690999A
Cited
EP0142149A2
Cited
US4535101A
Cited
US4595548A
Cited
US4603061A
Cited
US4533574A
Cited
US4562100A
Cited
US4759958A
Cited
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 |