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US 6,274,852 B1Granted
Conductive polymer compositions containing N-N-M-phenylenedimaleimide and devices
AssigneeTherm-O-Disc, Incorporated
InventorsEdward J. Blok, Prasad Khadkikar
Life of this patent
Estimating the term…
Abstract
The invention provides polymeric PTC compositions and electrical PTC devices with a high voltage capability and improved electrical stability. The polymeric PTC compositions are readily blended and generally do not require cross-linking, particularly radiation induced cross-linking in order to manufacture useful products.
Claims29
A polymeric PTC composition comprising an organic polymer, a particulate conductive filler;
- an organic stabilizer including N-N-m phenylenedimaleimide and, optionally, one or more additives selected from the group consisting of inert fillers, flame retardants, stabilizers, antioxidants, antiozonants, accelerators, pigments, foaming agents, crosslinking agents, coupling agents, co-agents and dispersing agents.
An electrical device which exhibits PTC behavior, comprising:
- (a) a conductive polymeric composition that comprises an organic polymer component including perhydrotriphenylene, a particulate conductive filler, and, optionally, one or more additives selected from the group consisting of inert fillers, flame retardants, stabilizers, antioxidants, antiozonants, accelerators, pigments, foaming agents, crosslinking agents and dispersing agents, the composition having a resistivity at 25° C. of 100 Ωcm or less, the composition having a resistivity at 25° C. of 100 Ωcm or less and a resistivity at its switching temperature that is at least 103 times the resistivity at 25° C.;
- and
- (b) at least two electrodes which are in electrical contact with the conductive polymeric composition to allow a DC or an AC current to pass through the composition under an applied voltage, wherein the device has a resistance at 25° C. of 500 mΩ or less with a desirable design geometry.
Dependencies are inferred from the claim text.