# US 2018/0322980 A1 · Surface Treating Magnet Wire Enamel Layers To Promote Layer Adhesion > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0322980 A1 - Document ID: US20180322980A1 - Status: Published application - Kind: A1 - Application number: 15/966,736 - Filed: 2018-04-30 - Published: 2018-11-08 - Earliest claimed: 2017-05-05 - Assignees: Essex Group, Inc. - Applicants: Essex Group, Inc. - Inventors: Matthew Leach; Allan R. Knerr - Web page: https://patentgrep.com/patent/US20180322980A1 ## CPC - H01B 3/30: plastics; resins; waxes - H01B 3/081: {Wires with vitreous enamels} - H01B 7/292: {using material resistant to heat} - H01B 7/0225: {Three or more layers} - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) ## Abstract A method for forming an insulated winding wire with enhanced adhesion between enamel layers is described. A conductor may be provided, and a first enamel layer may be formed around the conductor. The first enamel layer may include a first thermoset polymeric material. An outer surface of the first enamel layer maybe modified, for example, by a plasma, corona, ultraviolet, or flame treatment. The surface modification may alter a surface energy of the first enamel layer. A second enamel layer may be formed on the first enamel layer, and the second enamel layer may include a second thermoset polymeric material. ## Claims ### Claim 1 A method for forming an insulated winding wire, the method comprising: providing a conductor: forming a first enamel layer around the conductor, the first enamel layer comprising a first thermoset polymeric material; modifying an outer surface of the first enamel layer via at least one of a plasma, corona, ultraviolet, or flame treatment; and forming a second enamel layer on the first enamel layer, the second enamel layer comprising a second, thermoset polymeric material. ### Claim 2 (depends on 1) The method of claim 1, wherein modifying an outer surface of the first enamel layer promotes adhesion between the first enamel layer and the second enamel layer. ### Claim 3 (depends on 1) The method of claim 1, wherein modifying an outer surface of the first enamel layer comprises increasing a surface energy of the first enamel layer by approximately 20 to approximately 75 mN/m. ### Claim 4 (depends on 1) The method of claim 1, wherein modifying the outer surface of the first enamel layer comprises forming one or more functional groups on the outer surface. ### Claim 5 (depends on 1) The method of claim 1, wherein forming a first enamel layer comprises applying a first varnish, comprising the first thermoset polymeric material and curing the first varnish, and wherein forming a second enamel layer comprises applying a second varnish comprising the second thermoset polymeric material and curing the second varnish. ### Claim 6 (depends on 1) The method of claim 1, wherein, at least one of forming a first enamel layer comprising a first thermoset polymeric material or forming a second enamel layer comprising a second thermoset polymeric material comprises forming a layer comprising polyimide. ### Claim 7 (depends on 1) The method of claim 1, wherein, at least one of forming a first enamel layer comprising a first thermoset polymeric material or forming a second enamel layer comprising a second thermoset polymeric material comprises forming a layer comprising one of polyimide, polyamideimide, amideimide, polyester, polyesterimide, polysulfone, polyphenylenesulfone, polysulfide, polyphenylenesulfide, polyetherimide, or polyamide. ### Claim 8 (depends on 1) The method of claim 1, further comprising: modifying an outer surface of the conductor via a plasma, corona, or flame treatment prior to forming the first enamel layer. ### Claim 9 (depends on 1) The method of claim 1, further comprising: modifying an outer surface of the second enamel layer via at least one of a plasma, corona, ultraviolet, or flame treatment; and forming a third enamel layer on the second enamel layer, the third enamel layer comprising a third thermoset polymeric material. ### Claim 10 (depends on 1) The method of claim 1, further comprising forming an extruded thermoplastic layer around the second enamel layer. ### Claim 11 A method for forming an insulated winding wire, the method comprising: providing a conductor; forming a first enamel, layer around the conductor, the first enamel layer comprising a first thermoset polymeric material; treating an outer surface of the first enamel layer in order to increase a surface energy of the first enamel layer by approximately 20 to approximately 75 mN/m; and forming a second enamel layer on the first enamel layer, the second enamel layer comprising a second thermoset polymeric material. ### Claim 12 (depends on 11) The method of claim 11, wherein treating an outer surface of the first enamel layer comprises treating an outer surface of the first enamel layer via at least one of a plasma, corona, ultraviolet, or flame treatment. ### Claim 13 (depends on 11) The method of claim 11, wherein, treating an outer surface of the first enamel layer further promotes adhesion between the first enamel layer and the second enamel layer. ### Claim 14 (depends on 11) The method of claim 11, wherein at least one of forming a first enamel layer comprising a first thermoset polymeric material or forming a second enamel layer comprising a second thermoset polymeric material comprises forming a layer comprising polyimide. ### Claim 15 (depends on 11) The method of claim 11, wherein at least one of forming a first enamel layer comprising a first thermoset polymeric material or forming a second enamel layer comprising a second thermoset polymeric material comprises forming a layer comprising one of polyimide, polyamideimide, amideimide, polyester, polyesterimide, polysulfone, polyphenylenesulfone, polysulfide, polyphenylenesulfide, polyetherimide, or polyamide. ### Claim 16 A method tor forming an insulated winding wire, the method comprising: providing a conductor; forming a plurality of successive layers of enamel around the conductor, each of the plurality of layers of enamel comprising at least one thermoset material; and modifying an outer surface of at least one of the plurality of layers of enamel prior to the formation of a next of the plurality of layers of enamel on the modified outer surface. ### Claim 17 (depends on 16) The method of claim 16, wherein modifying an outer surface of at least one of the plurality of layers of enamel comprises modifying an outer surface via at least one of a plasma, corona, ultraviolet, or flame treatment. ### Claim 18 (depends on 16) The method of claim 16, wherein modifying an outer surface of at least one of the plurality of layers of enamel comprises increasing a surface energy of the at least one of the plurality of layers of enamel by approximately 20 to approximately 75 mN/m. ### Claim 19 (depends on 16) The method of claim 16, wherein forming a plurality of successive layers of enamel comprises forming a plurality of successive layers of enamel that each comprise polyimide. ### Claim 20 (depends on 16) The method of claim 16 wherein funning a plurality of successive layers of enamel comprises forming a plurality of successive layers of enamel that each comprise one of polyimide, polyamideimide, amideimide, polyester, polyesterimide, polysulfone, polyphenylenesulfone, polysulfide, polyphenylenesulfide polyethenmide, or polyamide.