Film coated amalgam

The utility model discloses a film coated amalgam which belongs to the technical field of the amalgam. The utility model comprises a spherical amalgam main body, and the surface of the amalgam main body is coated with a layer of protective film. The optimum thickness of the surface protective film of the amalgam is between 50 nm and 100 nm, the phenomena of mercury separation and the conglutination do not occur on the surface of the utility model even if the mercury content reaches 40% and 50%, and simultaneously a good low-temperature characteristic which is approximate to the pure mercury is obtained. The protective film is made of one kind or many kinds of Al< 2 >, O< 3 >, TiO< 2 >, ZrO< 2 >, SrCO< 3 >, ZnCO< 3 > and fluorescent powder, the performance of the protective film is stable and no decomposition or deterioration occurs during the light tube manufacture process and the use process of the light tube. Under the premise that the temperature characteristics curve of the amalgam is not influenced, the mercury separation or the conglutination of the amalgam, the mercury content of which is larger than 35%, are avoided, the utility model is convenient for the manufacture, the transportation and the protection and the utility model is favorable to the environmental protection and the use of a round exhaust machine.