| 摘要 |
#CMT# #/CMT# Electroconductive paste comprises 50-70 wt.% of a liquid glass, 2-30 wt.% of a natural graphite, 10-40 wt.% of a cryptocrystalline graphite and 0-10 wt.% of a filler. #CMT# : #/CMT# Independent claims are included for: (1) a heating element comprises a metallic, ceramic or glass made carrier material, a resistive layer to generate heat by electric current on the carrier material, an insulation layer with defined dielectric strength arranged between the resistive layer and the carrier material, and a protective layer, where the resistive layer consists of the electrically conductive paste; and (2) manufacturing the heating element comprising providing the metallic, ceramic or glass made substrate, applying the insulation layer, applying the electroconductive paste by a lithographic process, curing the electroconductive paste and applying the protective layer. #CMT#USE : #/CMT# The electroconductive paste is useful for the production of heating elements with a specific resistivity of 0.3-3.5x 10 -> 3>omega m (claimed). #CMT#ADVANTAGE : #/CMT# The electroconductive paste provides heating elements with increased reliability, high efficiency and stability for 12 hours, without consuming large amount power, hence economical. #CMT#INORGANIC CHEMISTRY : #/CMT# Preferred Method: The curing of the paste takes place at 30-50[deg] C. Preferred Components: The natural graphite has a carbon content of at least 88% and an ash content of maximum 12%, where at least 60% the natural graphite has a particle size of less than 149 mu m. The crypto-crystalline graphite has a carbon content of at least 83% and an ash content of maximum 17%, where up to 99% and up to 90% of the crypto-crystalline graphite has a particle size of less than 210 mu m and less than 149 mu m, respectively. The total carbon content in the electroconductive paste is 45-55 wt.%. The filler comprises at least 90, preferably 99.9 wt.% of silica. The working temperature of the heating element is up to 650[deg] C. In the liquid glass, the molar ratio of silica to sodium oxide is 2.6:3. The liquid glass comprises 29-36 wt.% of silica, 10-14 wt.% of sodium oxide, maximum 0.25 wt.% of iron oxide, maximum 0.2 wt.% of calcium oxide and maximum 0.15 wt.% sulfur oxide. #CMT#EXAMPLE : #/CMT# None given. |
