| 摘要 |
1444722 Electrically conductive compositions B J HARRIS 20 Aug 1973 [25 Aug 1972] 39756/72 Heading C3P [Also in Divisions F4 and H5] Electrical resistance heating elements (see Divisions H3-H5) having a positive temperature coefficient of resistance are composed of a synthetic resin and conducting and non-conducting materials. In exemplary compositions, the resin is a polyester, the conducting material is graphite, the non-conducting material is "silica alumina" (SiO 2 54À55%, Al 2 O 3 42À43% with traces of minor constituents), calcium aluminate, silica, or a non-conducting form of aluminium powder. Mentioned but not exemplified are the use of an epoxy as the resin and silicious materials as conductor. |
