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US 4,379,916 AGranted
Method for coprecipitating wire coating enamel composition
AssigneeGeneral Electric Company
InventorRalph G. Flowers
Life of this patent
Estimating the term…
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.
Claims12
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.
1 more element
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.
2 more elements
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.
1 more element
Dependencies are inferred from the claim text.