| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide low expansion optical glass for mold press molding which does not use lead oxide (PbO) or arsenic oxide (As<SB>2</SB>O<SB>3</SB>) having large environmental load, is easily treated in a step from glass melting to mold press molding to improve the productivity, and has excellent weather resistance. <P>SOLUTION: The optical glass is substantially made from a composition comprising 3.0-18.0 mass% SiO<SB>2</SB>, 20.0-38.0 mass% B<SB>2</SB>O<SB>3</SB>, 48.0-65.0 mass% ZnO and 0.1-9.0 mass% one kind or total of two or more kinds selected from Li<SB>2</SB>O, Na<SB>2</SB>O and K<SB>2</SB>O (where, Li<SB>2</SB>O is 0-3.0 mass%, Na<SB>2</SB>O is 0-8.0 mass% and K<SB>2</SB>O is 0-3.0 mass%) and the average linear expansion coefficientα<SB>(30-300)</SB>is 40.0×10<SP>-7</SP>-65.0×10<SP>-7</SP>/°C. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
