Electrical circuit protection devices comprising PTC conductive liquid crystal polymer compositions
US5691689A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 11, 1995 |
| Grant date | Nov 25, 1997 |
| Priority date | — |
| Expiry date | Aug 11, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01G4/1227
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Electrical circuit protection devices containing PTC elements comprised of conductive polymers which exhibit PTC behavior and are used to protect a load in an electrical circuit, in which the PTC conductive polymers are based on highly crystalline and highly ordered liquid crystal polymers and particulate conductive fillers dispersed therein, which are cross-linked by radiation. These circuit protection devices operate as automatically resettable current limiters and are particularly useful for protecting motors, solenoids, telephone lines and batteries, and for enhancing circuit interruption capability when used in conjunction with breakers and contactors. The liquid crystal polymers include aromatic polyesters, e.g., poly(p-phenylene terephthalate) and poly(p-hydroxybenzoate); aromatic copolyesters, e.g., poly(p-hydroxybenzoate-co-2,6-hydroxynaphthoate), poly(deca-methyleneterephthaloyl di-p-hydroxybenzoate, and poly(ethylene terephthalate-co-oxybenzoate); aromatic copolyester amides, e.g., poly(2,6-hydroxy-naphoate-phenoxyaminoterephthoate); aromatic polyamides, e.g., poly(p-phenylene terephthalamide), Kevlar, poly(p-benzamide), poly(2-chloro-1,4-phenylene terephthalamide), poly…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.