US4040993A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low dissipation factor electrostatic epoxy wire coating powder
Assignee: Westinghouse Electric Corp
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Filing: 1976-02-25
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Granted: 1977-08-09
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Expires: 1996-02-25
Abstract
Abstract A coating powder is made by hot melt mixing a composition of three diglycidyl ethers of bisphenol A, a pre-prepared epoxy ester, and a curing agent containing trimellitic anhydride. The composition is cooled to form a solid which is ground into a powder. Wire or other articles are coated with the coating powder in an electrostatic fluidized bed or with an electrostatic gun and the powder is cured.
Inventors
- 👤 Irving N. Elbling
- 👤 Howard E. Saunders
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:14
CPC Classifications
C; C09; C09D; C09D163/00; C08; C08G; C08G59/00; C08G59/18; C08G59/20; C08G59/22; C08G59/226; C08G59/40; C08G59/42; C08G59/4207; C08G59/4223; Y; Y10; Y10S; Y10S524/00; Y10S524/904; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/294; Y10T428/31504; Y10T428/31511; Y10T428/31529; Y10T428/31678
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
258 words
A coating powder made by A. preparing by dry mixing a composition which comprises: 1. about 20 to about 80 phr of a first diglycidyl ether of bisphenol A having an E.E.W. of at least 1600 and a Durran's softening point of at least 113° C., 2. about 10 to about 60 phr of a second diglycidyl ether of bisphenol A having an E.E.W. of 700 to 900 and a Durran's softening point of at least 112; and, 3. about 5 to about 50 phr of a third digylycidyl ether of bisphenol A having an E.E.W. of less than 1000 and a Durran's softening point of less than 105° C.; 4. about 10 to about 60 phr of a pre-prepared epoxy ester, the epoxy portion of said ester being derived from a diglycidyl ether of bisphenol A having an E.E.W. of at least about 400 and a Durran's softening point of at least about 70, and the ester portion being derived from a dibasic acid having the formula HOOC--(CH 2 )m-- COOH, where m is about 18 to about 54; and 5. about 5 to about 20 phr of a curing agent for said diglycidyl ethers, at least about 10% by weight of the anhydride equivalent weight of said curing agent being selected from the group consisting of trimellitic anhydride, esterified trimellitic anhydride, and mixtures thereof; B. hot melt mixing said composition; C. cooling said composition to form a solid; D. grinding said composition into a powder having a particle size of about 5 to about 149 microns.
Claim 2
Dependent Claim
258 words
A coating powder made by A. preparing by dry mixing a composition which comprises: 1. about 20 to about 80 phr of a first diglycidyl ether of bisphenol A having an E.E.W. of at least 1600 and a Durran's softening point of at least 113° C., 2. about 10 to about 60 phr of a second diglycidyl ether of bisphenol A having an E.E.W. of 700 to 900 and a Durran's softening point of at least 112; and, 3. about 5 to about 50 phr of a third digylycidyl ether of bisphenol A having an E.E.W. of less than 1000 and a Durran's softening point of less than 105° C.; 4. about 10 to about 60 phr of a pre-prepared epoxy ester, the epoxy portion of said ester being derived from a diglycidyl ether of bisphenol A having an E.E.W. of at least about 400 and a Durran's softening point of at least about 70, and the ester portion being derived from a dibasic acid having the formula HOOC--(CH 2 )m-- COOH, where m is about 18 to about 54; and 5. about 5 to about 20 phr of a curing agent for said diglycidyl ethers, at least about 10% by weight of the anhydride equivalent weight of said curing agent being selected from the group consisting of trimellitic anhydride, esterified trimellitic anhydride, and mixtures thereof; B. hot melt mixing said composition; C. cooling said composition to form a solid; D. grinding said composition into a powder having a particle size of about 5 to about 149 microns.
Claim 3
Dependent Claim
36 words
A coating powder according to claim 1 wherein said second diglycidyl ether of bisphenol A has an E.E.W. of about 780 to about 825 and a Durran's softening point of about 112° to about 120° C.
Claim 4
Dependent Claim
17 words
A coating powder according to claim 1 wherein said hot melt mixing is performed in an extruder.
Claim 5
Dependent Claim
20 words
A coating powder according to claim 3 wherein said hot melt mixing is performed in a kneader or twin-screw extruder.
Claim 6
Dependent Claim
23 words
A coating powder according to claim 1 wherein said hot melt mixing is performed near but above the melting point of said composition.
Claim 7
Dependent Claim
26 words
A coating powder according to claim 1 wherein said composition is ground to a powder having a particle size of about 200 to about 400 mesh.
Claim 8
Dependent Claim
21 words
A coating powder according to claim 1 wherein said composition includes about 0.05 to about 3% of a flow control agent.
Claim 9
Dependent Claim
12 words
A coating powder according to claim 1 wherein m is about 36.
Claim 10
Dependent Claim
21 words
A coating powder according to claim 1 wherein the amount of said epoxy ester is about 40 to about 60 phr.
Claim 11
Dependent Claim
16 words
A coating powder according to claim 1 wherein said curing agent is at least 10% TMA.
Claim 12
Dependent Claim
22 words
A coating powder according to claim 1 wherein said esterified TMA is a di or tri TMA ester of a polyhyric alcohol.
Claim 13
Independent Claim
72 words
A method of making a coating powder comprising: A. preparing by dry mixing a composition which comprises: 1. a first diglycidyl ether of bisphenol A having an E.E.W. of at least 1600 and a Durran's softening point of at least 113° C.; 2. about 10 to about 60 phr of a second diglycidyl ether of bisphenol A having an E.E.W. of 700 to 900 and a melting point of at least 112°;
Claim 14
Independent Claim
72 words
A method of making a coating powder comprising: A. preparing by dry mixing a composition which comprises: 1. a first diglycidyl ether of bisphenol A having an E.E.W. of at least 1600 and a Durran's softening point of at least 113° C.; 2. about 10 to about 60 phr of a second diglycidyl ether of bisphenol A having an E.E.W. of 700 to 900 and a melting point of at least 112°;
Claim 15
Dependent Claim
156 words
about 5 to about 50 phr of a third diglycidyl ether of bisphenol A having an E.E.W. of less than 1000 and a Durran's softening point of less than 105° C.; 4. about 10 to about 60 phr of a pre-prepared epoxy ester, the epoxy portion of said ester being derived from a diglycidyl ether of bisphenol A having an E.E.W. of at least about 400 and a Durran's softening point of at least about 70, and the ester portion being derived from a dibasic acid having the formula HOOC--(CH 2 )m--COOH, where m is about 18 to about 54; and 5. about 5 to about 20 phr of a curing agent for said diglycidyl ethers at least about 10% by weight of the anhydride equivalent weight of said curing agent being trimellitic anhydride; B. hot melt mixing said composition; C. cooling said composition to form a solid; and D. grinding said composition into a powder.
Claim 16
Dependent Claim
156 words
about 5 to about 50 phr of a third diglycidyl ether of bisphenol A having an E.E.W. of less than 1000 and a Durran's softening point of less than 105° C.; 4. about 10 to about 60 phr of a pre-prepared epoxy ester, the epoxy portion of said ester being derived from a diglycidyl ether of bisphenol A having an E.E.W. of at least about 400 and a Durran's softening point of at least about 70, and the ester portion being derived from a dibasic acid having the formula HOOC--(CH 2 )m--COOH, where m is about 18 to about 54; and 5. about 5 to about 20 phr of a curing agent for said diglycidyl ethers at least about 10% by weight of the anhydride equivalent weight of said curing agent being trimellitic anhydride; B. hot melt mixing said composition; C. cooling said composition to form a solid; and D. grinding said composition into a powder.
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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) | 1980-08-08 | 1981-02-07 | 1981-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-08 | 1985-02-07 | 1985-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-08 | 1989-02-07 | 1989-08-09 | $7700.00 | Window Closed / Lapsed |