Polymer compositions exhibiting a PTC property and methods of fabrication
US7309849B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 2004 |
| Grant date | Dec 18, 2007 |
| Priority date | — |
| Expiry date | Mar 29, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B2203/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Various embodiments of the invention provide polymeric compositions including PTC composites that exhibit highly non-linear PTC effects together with extremely rapid, repeatable switching within a predetermined temperature range. In one embodiment, the polymer composite includes a polymer base material with dispersed conductive particles that have very low densities and very low thermal conductivity properties. The conductive particle component can comprise hollow glass microspheres to provide low mass and low thermal conductivity properties together with a nanoscale conductive cladding of silver or gold. The conductively clad microspheres have a core portion with a bulk density of less than about 2.0 g/cm3 and a mean thermal conductivity of less than about 5.0 W/m-° K.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.