GLASS FOR SOLAR-HEAT-COLLECTING TUBE, GLASS TUBE FOR SOLAR-HEAT-COLLECTING TUBE, AND SOLAR-HEAT-COLLECTING TUBE

摘要

Provided is a glass for a solar-heat-collecting tube, the glass capable of being formed into a tube by applying the high-productivity Danner method, and the glass being provided with various characteristics such as optical transparency, weatherability, and sealability (ability to bond with metal); a glass tube for a solar-heat-collecting tube using glass of such description, and a solar-heat-collecting tube. The glass for the solar-heat-collecting tube contains 65-80% of SiO₂, 3-10% of Al₂O₃, 12-18% of B₂O₃, 0-3% of Li₂O, 1-8% of Na₂O, 1-8% of K₂O, 0-3% of CaO, 0-3% of MgO, 0-3% of BaO, 0-3% of SrO, 0-3% of ZnO, 0-3% of ZrO₂, 0-1% of SnO₂, 0-3% of Sb₂O₃, and 0-0.06% of Fe₂O₃, the amounts being expressed in terms of weight percentage on an oxide basis. The total Li₂O, Na₂O, and K₂O content is 5-10%. The glass contains 0-2 wt% of F. The glass tube for the solar-heat-collecting tube comprises the glass for the solar-heat-collecting tube, and the solar-heat-collecting tube is provided with a glass tube of such description for the solar-heat-collecting tube.