Composite coatings for groundwall insulation, method of manufacture thereof and articles derived therefrom

An article comprising:

• an electrical component, the electrical component being an electrical conduction winding, stator bar, or a stator piece;
• and
• an electrically insulating layer disposed upon the electrical component, wherein the electrically insulating layer comprises a thermosetting polymer and a nanosized filler having an average largest dimension of less than or equal to about 75 nanometers;
• wherein the thermosetting polymer comprises polyurethanes, silicones, polycarbonates, polystyrenes, polyarylates, polyarylsulfones, polyethersulfones, polyphenylene sulfides, polysulfones, polytetrafluoroethylenes, polyetherketones, polyether etherketones, polyether ketone ketones, polybenzoxazoles, polyoxadiazoles, polybenzothiazinophenothiazines, polybenzothiazoles, polypyrazinoquinoxalines, polyquinoxalines, polybenzimidazoles, polyoxindoles, polyoxoisoindolines, polydioxoisoindolines, polytriazines, polypyridazines, polypiperazines, polypyridines, polypiperidines, polytriazoles, polypyrazoles, polycarboranes, polyoxabicyclononanes, polydibenzofurans, polyphthalides, polyacetals, polyanhydrides, polyvinyl ethers, polyvinyl thioethers, polyvinyl alcohols, polyvinyl ketones, polyvinyl halides, polyvinyl nitriles, polyvinyl esters, polysulfonates, polysulfides, polythioesters, polysulfonamides, polyureas, polyphosphazenes, polysilazanes, or combinations comprising at least one of the foregoing thermosetting polymers;
• wherein the nanosized filler comprises a mineral filler comprising mica, wherein the mica comprises phlogopite (KMg3AlSi3O10(OH)2) or muscovite (K2Al4[Si6Al2O20](OH, F)4);
• wherein the nanosized filler is used in an amount of 0.01 to 30 wt % based on the total weight of the insulating layer;
• and
• wherein the electrically insulating layer has a thickness of about 25 to about 300 micrometers and an electrical breakdown strength of greater than or equal to about 0.75 kilovolt.

An article comprising:

• an electrical component, the electrical component being an electrical conduction winding, stator bar, or a stator piece;
• and
• an electrically insulating layer disposed upon the electrical component, wherein the electrically insulating layer comprises a thermosetting polymer, and a nanosized filler having an average largest dimension of less than or equal to about 75 nanometers;
• wherein the nanosized filler comprises nanosized metal oxide having the formula Ni0.5Zn0.5Fe2O4;
• wherein the thermosetting polymer comprises polyurethanes, silicones, polycarbonates, polystyrenes, polyarylates, polyarylsulfones, polyethersulfones, polyphenylene sulfides, polysulfones, polytetrafluoroethylenes, polyetherketones, polyether etherketones, polyether ketone ketones, polybenzoxazoles, polyoxadiazoles, polybenzothiazinophenothiazines, polybenzothiazoles, polypyrazinoquinoxalines, polyquinoxalines, polybenzimidazoles, polyoxindoles, polyoxoisoindolines, polydioxoisoindolines, polytriazines, polypyridazines, polypiperazines, polypyridines, polypiperidines, polytriazoles, polypyrazoles, polycarboranes, polyoxabicyclononanes, polydibenzofurans, polyphthalides, polyacetals, polyanhydrides, polyvinyl ethers, polyvinyl thioethers, polyvinyl alcohols, polyvinyl ketones, polyvinyl halides, polyvinyl nitriles, polyvinyl esters, polysulfonates, polysulfides, polythioesters, polysulfonamides, polyureas, polyphosphazenes, polysilazanes, or combinations comprising at least one of the foregoing thermosetting polymers;
• wherein the nanosized filler is used in an amount of 0.01 to 30 wt % based on the total weight of the insulating layer, and
• wherein the electrically insulating layer has a thickness of about 25 to about 300 micrometers and an electrical breakdown strength of greater than or equal to about 0.75 kilovolt.

A method of manufacturing an article comprising:

• disposing an electrically insulating layer upon an electrical component, wherein the electrically insulating layer comprises a thermosetting polymer comprising polyurethanes, phenolics, silicones, polycarbonates, polystyrenes, polyesters, polyarylates, polyarylsulfones, polyethersulfones, polyphenylene sulfides, polysulfones, polytetrafluoroethylenes, polyetherketones, polyether etherketones, polyether ketone ketones, polybenzoxazoles, polyoxadiazoles, polybenzothiazinophenothiazines, polybenzothiazoles, polypyrazinoquinoxalines, polyquinoxalines, polybenzimidazoles, polyoxindoles, polyoxoisoindolines, polydioxoisoindolines, polytriazines, polypyridazines, polypiperazines, polypyridines, polypiperidines, polytriazoles, polypyrazoles, polycarboranes, polyoxabicyclononanes, polydibenzofurans, polyphthalides, polyacetals, polyanhydrides, polyvinyl ethers, polyvinyl thioethers, polyvinyl alcohols, polyvinyl ketones, polyvinyl halides, polyvinyl nitriles, polyvinyl esters, polysulfonates, polysulfides, polythioesters, polysulfonamides, polyureas, polyphosphazenes, polysilazanes, or combinations comprising at least one of the foregoing thermosetting polymers, and
• a nanosized filler;
• wherein the nano sized filler consists essentially of particles having the formula (II)
• (MeO)x.(Fe2O3)100-x (II)
• where MeO is any divalent ferrite forming metal oxide or a combination comprising two or more divalent metal oxides, and “x” is less than 50 mole percent, wherein the nanosized filler has an average largest dimension of less than or equal to about 200 nanometers, and wherein the nanosized filler particles are used in an amount of about 2 to about 15 wt % based on the total weight of the insulating layer;
• and
• curing the thermosetting polymer,
• wherein the electrical component is an electrical conduction winding, stator bar, or a stator piece, and
• wherein the electrically insulating layer has a thickness of about 25 to about 300 micrometers and an electrical breakdown strength of greater than or equal to about 0.75 kilovolt.