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US 5,212,218 AGranted
Hydrophobic, erodiable synthetic resin composition for electrical insulators
AssigneeA. B. Chance Company
InventorWilliam M. Rinehart
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AssigneeA. B. Chance Company
InventorWilliam M. Rinehart
Estimating the term…
Improved synthetic resin insulators having enhanced arc track resistance and reduced UV light degradation characteristics are provided which include a continuous resin phase and a discrete, discontinuous hydrophobic phase in the form of discrete, suspended droplets within the resin. The preferred insulators are formed of a continuous epoxy matrix having suspended droplets of petrolatum dispersed therein. The resin phase comprises from about 15 to 50% by weight of the composition, whereas the hydrophobe is present at a level from about 2 to 10% by weight. UV light resistance is improved by predissolving or predispersing a quantity of UV light absorber in the hydrophobe before the latter is mixed with the resin phase. Use of a hydrophobe which is solid at normal temperatures but which melts above about 80.degree. F. (such as petrolatum) results in lower dust attraction during ordinary conditions and the ability to melt and effectively encapsulate surface dust during periods of increased arcing activity.
An insulative body having at least the outer portion thereof formed of a dielectric composition, said composition comprising a continuous phase, a discrete, discontinuous, hydrophobic phase, a minor amount of a dispersant, and a UV light absorber, said continuous phase being selected from the group consisting of the epoxy, urethane and silicone rubber resins and mixtures thereof, said hydrophobic phase being present in said continuous phase as discrete, suspended droplets, said droplets being formed of hydrophobic material which is substantially solid at room temperature but which melts at a temperature above about 80.degree. F., said dielectric composition being formed by separately preparing an additive comprising a quantity of said hydrophobic material with said UV light absorber dissolved or dispersed therein, and thereafter incorporating said additive with the remaining ingredients of the dielectric composition.
An additive for addition to a continuous resin phase in order to form a two-phase insulative composition, said additive consisting essentially of a quantity of hydrophobic material which is essentially solid at room temperature but which melts at a temperature above about 80.degree. F., said hydrophobic material having an ultraviolet light absorber dissolved or dispersed therein, said additive being essentially free of said resin prior to said addition thereof to the resin.
Dependencies are inferred from the claim text.