Abstract:
Curable compositions containing a reaction product of at least one bisphenol polyglycidyl ether, at least one epoxidized novolak and at least one brominated bisphenol, in combination with a polyphenylene ether and further components including specific catalysts and hardeners, may be used in the preparation of laminates useful as printed circuit boards and having excellent physical and electrical properties.
Abstract:
A method for making a dynamoelectric machine conductor bar, compromises providing a plurality of bundled together spiraling strand conductors having surrounding insulation to define a substantially rectangular shape with the strand conductors and strand insulation defining an opposing conductor bar end portion having an electrically insulated gap between the strand insulation adjacent the bar end portion; and applying a filler material to fill the gap to electrically shield the conductor bar end portion and to a greater than 0.080 to about 1.5 inch continuous outer radius surface end portion. A dynamoelectric machine conductor bar comprises a plurality of bundled together spiraling strand conductors having surrounding insulation to define a substantially rectangular shape, with the strand conductors and strand insulation defining an opposing conductor bar end portion; an electrically non-insulated gap between the strand insulation adjacent the conductors at the bar end portion, and an applied filler material filling the gap to electrically shield the conductor bar end portion an applied filler material filling the gap to electrically shield the conductor bar end portion, wherein the filler material defines a greater than 0.080 to about 1.5 inch continuous outer radius surface end portion.
Abstract:
A bare copper conductor is provided with a tenaciously adhering epoxy resin by heating and curing in situ on the conductor a coating of a solution of cycloaliphatic epoxy resin, a hardener, stannous octoate as a catalyst, and a phenolic accelerator.
Abstract:
Resinous compositions used as electric insulation have unique corona-resistance increased from 10- to 100-fold or more by the addition of organoaluminate, organosilicate or fine alumina or silica of critical particle size, and dynamoelectric machines and transformers incorporating coils made of wire strands coated with these novel compositions consequently have substantially increased service lives.
Abstract:
Resin-impregnated sheet materials, such as fabrics, films, paper and tapes, for forming electrical insulation that exhibits significantly improved voltage endurance performance. The present invention finds particular use as groundwall insulation for high voltage generator stator bars, in which the groundwall insulation is formed by mica tape filled with submicron particles of silicon dioxide, aluminum oxide, titanium dioxide and/or zirconium dioxide, in combination with an unfilled mica tape impregnated with the same or compatible resin binder. The filled tape is preferably in the form of a mica paper having at least one woven fabric on at least one of its surfaces, a resin binder permeating the mica paper and woven fabric so as to bond the woven fabric to the mica paper, and oxide particles dispersed in the woven fabric.
Abstract:
An end winding (10) of a high voltage air-cooled ac generator or motor is made more resistant to surface deterioration by corona activity by using a paint whose binder contains at least 20% by weight silicone. An end winding, including its insulated conductors and separator and support structures, are coated with the paint whose composition includes a solvent or thinner, optional pigments, and the binder containing at least 20% by weight silicone. The balance (if any) of the binder can be, for example, an alkyd, acrylic, phenolic or epoxy resin.
Abstract:
A high voltage generator armature bar (10) that exhibits improved performance by forming one or more of its conductive components from a conductive material that uses a tin oxide-based composition as a conductive filler. The armature bar (10) is of the type having one or more tiers of conductor strands (12), strand insulation (14), conductive internal grading (20), groundwall insulation (22), conductive slot armoring (24), and preferably a transposition filler (18). The conductive internal grading (20), the conductive slot armoring (24) and/or the transposition filler (18) contain a conductive filler of antimony-doped tin oxide that may constitute the entire conductive filler, or can be present as a shell on the filler particles.
Abstract:
Low viscosity, solventless, thermosetting resin compositions of bismaleimide resin composition and epoxy resins have unique heat stability and special utility as insulation for electric conductors to be used in the 200.degree.-250.degree. C. temperature range.
Abstract:
A thermosetting resin composition of an epoxy resin mixture of 1,2 epoxy resin having at least two epoxide groups per molecule and a polyglycol diepoxide having viscosity of 2,000-5,000 centipoises at 25.degree. C. and in addition small but effective amounts of both a catalytic hardener and an accelerator has special utility in the production of composite molded bodies of electrical insulation having thermoplastic shells because of its unique combination of properties including thermal stability, thermal-cycling crack resistance, high impact strength, toughness, room-temperature curability and bondability to both thermoplastic and metallic surfaces, and because it does not stress crack thermoplastic shells to which it is bonded in curing.
Abstract:
A thermosetting resin composition of an epoxy resin mixture of 1,2 epoxy resin having at least two epoxide groups per molecule and a polyglycol diepoxide having viscosity of 2,000-5,000 centipoises at 25.degree. C. and in addition small but effective amounts of both a catalytic hardener and an accelerator has special utility in the production of composite molded bodies of electrical insulation having thermoplastic shells because of its unique combination of properties including thermal stability, thermal-cycling crack resistance, high impact strength, toughness, room-temperature curability and bondability to both thermoplastic and metallic surfaces, and because it does not stress crack thermoplastic shells to which it is bonded in curing.