PHOSPHORESCENT COMPOSITES TO BE EMPLOYED IN HIGHLY EFFICIENT LIGHTING SOURCES

摘要

The invention relates to a composite material to be employed for obtaining lighting sources and to a process for preparing the same. According to the invention, the composite material consists of a powder of strontium aluminate doped with 1% mol Eu and 2% Dy having dimensions of 5...10 μ m and polyethylene terephthalate, having a core-shell-type structure, at a dimension of composite particles ranging between 10...20 μ m, a clearness value of 70...80%, a melting temperature of 250...260°C. According to the invention, the process consists in dissolving the polyethylene terephthalate as granules or flakes in benzyl alcohol, at a temperature of 205°C, while stirring for 4...6 h, followed by cooling and admixing the strontium aluminate having a density of 3.62...3.64 g/ml, continuing stirring for 10...15 min, the reaction mass being then blast cooled and homogenized by nitrogen barbotage, thereby resulting a phosphorescent composite material having a mass content of strontium aluminate of 30...70%.