Preparation And Study Of Sodium-free And Lead-free Lighting Glass

Recently, with the development of economic and progress of science, electric light source has been widely used in architectural lighting, artistic lighting, electronic information industry, automobile, defense, medical health and other fields. Power consumption on illumination in china, which accounts for a considerable proportion of the total power consumption, is increasing year by year. Therefore, to develop high-efficiency, energy saving, environmental and long-life electrical lighting products becomes the main task of domestic illumination industry. As an important raw material for manufacturing electric light source products, glass is closely linked with the efficiency, energy conservation, environmental protection and life of light source. Our country is the largest lighting glass producing center, but not advanced and sophisticated yet. The products of China are far behind that of developed countries in technology and quality. Compositions and producing techniques that can make high-quality glasses conforming to standards Rosh are still controlled by a few foreign giant electric companies. Therefore, it is very important to research and develop products,with independent intellectual property, that meet the European and American standards and requirements in markets.Based on the Glass360of Philips Electronic N.V. CO. and referred to related literatures the chemical compositions of soda-free glass were designed in the present work. Then glasses were made by melt-annealing method. The compositional range of glasses components were as follows(wt%):50～70%SiO2;2～3.4%Al2O3;0～9%B2O3;0～3.2%Li2O;0～9%Na2O;5～14%K2O;1.3～3.3%MgO;1.9～3.9%CaO;4～6%SrO;8.4～10.4%BaO;0～1.5%CeO2;0～1%SnO2;0～1.5%TiO2;0.3%Sb2O3.The Physical and chemical properties such as the thermal performance, softening temperature, electrical properties, chemical stability, infrared transmission, ultraviolet cut-off performance and radiation resistant performance were tested. Effects of the compositions on glass properties were investigated one by one. The results indicated that the "mixed alkali effects" and "negative mixed alkali effects" appear when the three kinds of alkali metal oxides coexist. With the increase of B2O3/SiO2, the softening temperature Td descends obviously, but the thermal expansion coefficient decreases first and then increases when n(B2O3/K2O)≈1. The use of oxidation boron oxide to replace alkali metal oxide can decrease the dielectric loss and release of alkali metal ion. With the same content, CeO2has better ultraviolet ray absorption and visible light transmission than TiO2. In addition, codoping of0.5%CeO2+0.25%SnO2has a good performance on ultraviolet cut-off and resistance to radiation.