Cable having superior resistance to flame spread and smoke evolution
US5173960A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 6, 1992 |
| Grant date | Dec 22, 1992 |
| Priority date | — |
| Expiry date | Mar 6, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01B7/295
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A communications cable (20) in which plastic material which is disposed about each transmission medium thereof is characterized by a relatively low dielectric constant. The cable exhibits relatively low flame spread and low smoke generation while maintaining circuit integrity through a fire retardant composition which includes a mixture of an organic resin and first and second inorganic oxide constituents. The first inorganic oxide constituent is characterized by a melting point in the range of about 350.degree. C. The second inorganic oxide constituent comprises a higher melting devitrifying frit which begins to crystallize at about 650.degree. C. Advantageously, when the cable is exposed to high temperatures, the mixture of the first and second inorganic oxide constituents melts and forms a crusty layer which is interposed between the covering plastic material and other components of the cable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.