Temperature sensitive circuit breaking element
AssigneeMinnesota Mining and Manufacturing Company
InventorsRobin E. Wright, William V. Balsimo
Life of this patent
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Abstract
A composite article comprising a fibrillated polytetrafluoroethylene (PTFE) matrix, electrically conductive particles, and energy expandable, electrically nonconductive hollow polymeric particles, which composite is conductive and allows for the flow of electricity and which, upon attaining a temperature which causes expansion of the expandable polymeric particles, becomes insulating and causes the flow of electricity to cease. The articles are thin and can be used as electrical circuit breaking elements.
Claims17
An electrically conductive composite article comprising a polytetrafluoroethylene fibril matrix having enmeshed therein
- (a) electrically conductive metal-containing particles, and
- (b) electrically nonconductive, energy expandable hollow polymeric particles, said composite article having a resistivity of less than about 1000 .OMEGA..cm prior to expansion of said energy expandable particles and greater than about 10.sup.5 .OMEGA.. cm after expansion of said energy expandable particles.
An electrically conductive composite article comprising a polytetrafluoroethylene fibril matrix having enmeshed therein
- (a) electrically conductive metal-containing particles, and
- (b) electrically nonconductive, energy expandable hollow polymeric particles having a polymeric shell and a liquid or gaseous core said composite article having a resistivity of less than about 1000 .OMEGA..cm prior to expansion of said energy expandable particles and greater than about 10.sup.5 .OMEGA..cm after expansion of said energy expandable particles.
An irreversible fuse element comprising a polytetrafluoroethylene fibril matrix, having enmeshed therein
- a) electrically conductive particles, and
- b) electrically nonconductive, energy expandable hollow polymeric particles said composite article having a resistivity of less than about 1000 .OMEGA..cm prior to expansion of said energy expandable particles and greater than about 10.sup.5 .OMEGA..cm after expansion of said energy expandable particles.
Dependencies are inferred from the claim text.