Patent US4131711A successfully refreshed from Google Patents.
US4131711A
Expired / Lapsed
US
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Coating process using dispersions of tetrafluoroethylene polymers and polyethersulphones and article
Assignee: Imperial Chemical Industries Ltd
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Filing: 1978-05-08
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Granted: 1978-12-26
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Expires: 1998-05-08
Abstract
Abstract Substrates are coated with a composition comprising a low molecular weight polyethersulphone containing hydroxyl and groups and having a reduced viscosity of less than 0.25 (as measured at 25 DEG C on a solution of the polymer in dimethyl formamide containing 1 g of polymer in 100 cm3 of solution) and a fluorocarbon polymer dispersed in an aqueous medium, drying the coating and thereafter baking it in air at 420 to 450 DEG C.
Inventors
- 👤 Terence E. Attwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:22
CPC Classifications
C; C09; C09D; C09D181/00; C09D181/06; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/31504; Y10T428/31533; Y10T428/3154; Y10T428/31544
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
115 words
A process for the production of a coated article comprising applying to the article in a single coating step an aqueous dispersion of a tetrafluoroethylene polymer and a thermoplastic aromatic polyethersulphone in which at least 20% of the end groups of the polymer chain are aromatically bound hydroxyl groups and said polyethersulphone having a reduced viscosity below 0.25, as measured at 25° C. on a solution in dimethyl formamide containing 1 g of polymer in 100 cm 3 of solution, drying the coating, and thereafter baking the coated article in the presence of oxygen at a temperature in the range 420 to 450° C. to achieve a single coating of thickness at least 15 μm.
Claim 2
Dependent Claim
115 words
A process for the production of a coated article comprising applying to the article in a single coating step an aqueous dispersion of a tetrafluoroethylene polymer and a thermoplastic aromatic polyethersulphone in which at least 20% of the end groups of the polymer chain are aromatically bound hydroxyl groups and said polyethersulphone having a reduced viscosity below 0.25, as measured at 25° C. on a solution in dimethyl formamide containing 1 g of polymer in 100 cm 3 of solution, drying the coating, and thereafter baking the coated article in the presence of oxygen at a temperature in the range 420 to 450° C. to achieve a single coating of thickness at least 15 μm.
Claim 3
Dependent Claim
22 words
A process according to claim 1 wherein the coated article is baked at a temperature in the range 420 to 440° C.
Claim 4
Dependent Claim
19 words
A process according to claim 1 in which the aromatic polyethersulphone has a reduced viscosity between 0.03 and 0.2.
Claim 5
Dependent Claim
19 words
A process according to claim 3 wherein the aromatic polyethersulphone has a reduced viscosity of between 0.08 and 0.18.
Claim 6
Dependent Claim
15 words
A process according to claim 1 wherein the tetrafluoroethylene polymer is a lubricant grade polytetrafluoroethylene.
Claim 7
Dependent Claim
17 words
A process according to claim 1 wherein the aromatic polyethersulphone has repeat units of the formula ##STR12##
Claim 8
Dependent Claim
17 words
A process according to claim 1 wherein the tetrafluoroethylene polymer/polyethersulphone weight ratio is between 0.75:1 and 2:1.
Claim 9
Dependent Claim
17 words
A process according to claim 7 wherein the tetrafluoroethylene polymer/polyethersulphone weight ratio is between 0.9:1 and 1.4:1.
Claim 10
Dependent Claim
23 words
A process according to claim 1 wherein at least 40% of the end groups of the polymer chain are aromatically bound hydroxyl groups.
Claim 11
Dependent Claim
10 words
A coated article made by the method of claim 1.
References Cited (Backward Citations)
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US3984604A
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US3993843A
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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) | 1981-12-25 | 1982-06-26 | 1982-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-25 | 1986-06-26 | 1986-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-25 | 1990-06-26 | 1990-12-26 | $7700.00 | Window Closed / Lapsed |