Polymer compositions for electrical use
AssigneeRaychem Corporation
InventorsRichard J. Penneck, Paul Taylor
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Abstract
Novel polymeric compositions having non-linear resistance characteristics, together with electrical equipment comprising such compositions. Any polymer may be used; the polymer contains substantial proportions of certain particulate fillers of a given structure, for example the perovskite and spinel structures.
Claims31
In a high voltage electrical apparatus subject to electrical stress, the improvement comprising providing relief against said stress by a composition exhibiting a nonlinear electrical resistance with variation in voltage, said composition comprising a thermoplastic or elastomeric polymer having dispersed therein at least one particulate filler compound selected from the group consisting of:
- (a) compounds having a perovskite type crystal structure;
- (b) metal oxides and mixed metal oxides having an inverse spinel-type crystal structure;
- and
- (c) metal oxides and mixed metal oxides having a mixed spinel-type crystal structure, the total weight of said particulate compound or compounds being at least 10% based on the weight of the polymer and such as to give the composition a gamma value of at least 1.5 at some direct current stress between 0.01 and 10 kV/mm.
Dependencies are inferred from the claim text.