Phosphate glass, fluorophosphate glass, preform for precision press-molding, optical element and process for the production of thereof
AssigneeHoya Corporation
InventorMikio Ikenishi
Life of this patent
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Abstract
A fluorophosphate glass having a fluorine content of 25% or more by anionic %, which is produced from a glass raw material containing 0.1 to 0.5%, by anionic %, of a halide containing a halogen element selected from chlorine, bromine or iodine, and a phosphate glass having a fluorine content of less than 25% by anionic %, which is produced from a glass raw material containing 0.1 to 5%, by anionic %, of a halide containing a halogen element selected from chlorine, bromine or iodine.
Claims4
A phosphate glass comprising, by cationic %, 15 to 40% of PO2.5, 3 to 30% of NbO2.5, 0 to 15% of TiO2, 0 to 30% of WO3, 0 to 15% of BiO1.5, 0 to 25% of BO1.5, 0 to 20% of BaO, 0 to 10% of ZnO, 0 to 10% of MgO, 0 to 10% of CaO, 0 to 10% of SrO, 5 to 30% of LiO0.5, 0 to 30% of NaO0.5, 0 to 15% of KO0.5, 0 to 10% of AlO1.5, 0 to 10% of SiO2, 0 to 10% of LaO1.5, 0 to 10% of GdO1.5, 0 to 10% of YbO1.5, 0 to 10% of ZrO2 and 0 to 10% of TaO2.5 and a fluorine is present in an amount of less than 25% by anionic %, which is produced from a glass raw material containing 0.1 to 5%, by anionic %, of a halide containing a halogen element selected from chlorine, bromine or iodine.
Dependencies are inferred from the claim text.