US4379916A
Expired / Lapsed
US
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Method for coprecipitating wire coating enamel composition
Assignee: General Electric Co
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Filing: 1981-06-01
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Granted: 1983-04-12
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Expires: 2001-06-01
Abstract
Abstract Insulating wire coating enamels containing a mixture of polyvinyl acetal, phenolic and epoxy resins are prepared by precipitating the resins from a tetrahydrofuran solution with water. The precipitated resins are dried and electrostatically applied to transformer wire.
Inventors
- 👤 Ralph G. Flowers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:59
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/44; H01B3/446; C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/4009; C08G18/4063; C09; C09D; C09D129/00; C09D129/14; C09D161/00; C09D161/04; C09D161/06; C09D163/00; H01B3/308; H01B3/36; H01B3/40; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/294
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
75 words
Method for preparing a wire coating enamel consisting of a homogeneous mixture of phenolaldehyde, polyvinyl acetal and epoxy resins, said method comprising the steps of: dissolving the resin mixture in a water soluble, organic solvent to form a solution; mixing said solution in a volume of water greater than the volume of the solution to precipitate out said resins as a homogeneous mixture; and separating said precipitated resin mixture from said water and solvent mixture.
Claim 2
Dependent Claim
75 words
Method for preparing a wire coating enamel consisting of a homogeneous mixture of phenolaldehyde, polyvinyl acetal and epoxy resins, said method comprising the steps of: dissolving the resin mixture in a water soluble, organic solvent to form a solution; mixing said solution in a volume of water greater than the volume of the solution to precipitate out said resins as a homogeneous mixture; and separating said precipitated resin mixture from said water and solvent mixture.
Claim 3
Dependent Claim
16 words
The method of claim 1 including the further step of separating said solvent from said water.
Claim 4
Dependent Claim
11 words
The method of claim 2 wherein said separation comprises fractional distillation.
Claim 5
Dependent Claim
21 words
The method of claim 3 wherein said fractional distillation comprises heating said water-solvent mixture to separate said solvent from said mixture.
Claim 6
Dependent Claim
22 words
The method of claim 4 wherein said separated solvent is in the form of an azeotrope containing less than 10 percent water.
Claim 7
Dependent Claim
16 words
The method of claim 1 wherein said organic solvent has a boiling point lower than water.
Claim 8
Independent Claim
98 words
A method for forming wire coating enamel comprising the steps of: (a) dissolving a mixture of phenol aldehyde, polyvinyl acetal and epoxy resins in water soluble, organic solvent to form a solution; (b) mixing about one part of said solution into about 10 parts to about 12 parts of water to precipitate out said resins as a homogeneous mixture; (c) separating said precipitated resin mixture from the water-solvent mixture; and (d) heating said water-solvent mixture to form an azeotrope consisting of said water and said solvent, said azeotrope being reusable in step (a) for dissolving said resin mixture.
Claim 9
Independent Claim
98 words
A method for forming wire coating enamel comprising the steps of: (a) dissolving a mixture of phenol aldehyde, polyvinyl acetal and epoxy resins in water soluble, organic solvent to form a solution; (b) mixing about one part of said solution into about 10 parts to about 12 parts of water to precipitate out said resins as a homogeneous mixture; (c) separating said precipitated resin mixture from the water-solvent mixture; and (d) heating said water-solvent mixture to form an azeotrope consisting of said water and said solvent, said azeotrope being reusable in step (a) for dissolving said resin mixture.
Claim 10
Dependent Claim
16 words
The method of claim 7 wherein said azeotrope comprises less than 10 percent of said water.
Claim 11
Dependent Claim
10 words
The method of claim 7 wherein said solvent comprises tetrahydrofuran.
Claim 12
Dependent Claim
34 words
The method of claim 1 wherein the volume of the solution to the volume of water to precipitate out the resins is about 1 part solution to about 10 to about 12 parts water.
Claim 13
Independent Claim
70 words
A method of forming wire coating enamels comprising the steps of: dissolving a mixture of polyvinyl acetal, phenolic and epoxy resins in an azeotrope solution of tetrahydrofuran and water to form a resin solution; mixing about 1 part of said resin solution into about 10 to about 12 parts of water to precipitate out said resins as a homogeneous mixture; and separating said precipitated resin mixture from said azeotrope-water solution.
Claim 14
Independent Claim
70 words
A method of forming wire coating enamels comprising the steps of: dissolving a mixture of polyvinyl acetal, phenolic and epoxy resins in an azeotrope solution of tetrahydrofuran and water to form a resin solution; mixing about 1 part of said resin solution into about 10 to about 12 parts of water to precipitate out said resins as a homogeneous mixture; and separating said precipitated resin mixture from said azeotrope-water solution.
Claim 15
Dependent Claim
14 words
The method of claim 11 wherein said azeotrope comprises less than 10 percent water.
References Cited (Backward Citations)
US4089843A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-04-11 | 1986-10-11 | 1987-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-11 | 1990-10-11 | 1991-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-11 | 1994-10-11 | 1995-04-12 | $7700.00 | Window Closed / Lapsed |