Thermally entglasbares lead borosilicate glass with a relatively low lead content with a warmth expansion according to the devitrification of - 5 to + 30 x 10 high - 7 / °C. (in the case of 38 to 288°C.) and a process for the devitrification

摘要

Laminate comprising a ceramic layer, a PTFE coating and a bonding layer of a solder glass. Solder glass consists of 13-23 wt.% PbO, 4-11% B2O3, 4-6% LiO2, 14-19% Al2O3 and 39-50% SiO2. A nucleating agent may also be included. When crystallised the compositions have coefficients of thermal expansion in the range of about -5 to + 30x10-7/degrees C and contain lithia-alumina-silicate crystals (beta spodumene or beta-eucryptite) as the primary type, with no lead silicate or zinc silicate crystals present.