摘要 |
The present invention provides a high refractive index, high dispersion optical glass for precision molding, being free from harmful materials causing environmental problems, such as lead oxide, etc., and having a low yield temperature (At), i.e. at most 580° C., a refractive index (nd) of at least 1.89 and an Abbe number (nud) of at most 23.0 and further providing a low softening property as well as an improved mass production property with less coloration, which is represented in terms of for making up the glass, by the following chemical composition (wt %): <tables id="TABLE-US-00001" num="1"> <table frame="none" colsep="0" rowsep="0"> <tgroup align="left" colsep="0" rowsep="0" cols="4"> <colspec colname="OFFSET" colwidth="21PT" align="left"/> <colspec colname="1" colwidth="105PT" align="left"/> <colspec colname="2" colwidth="70PT" align="right"/> <colspec colname="3" colwidth="21PT" align="left"/> <THEAD> <ROW> <ENTRY/> <ENTRY/> </ROW> <ROW> <ENTRY/> <entry namest="OFFSET" nameend="3" align="center" rowsep="1"/> </ROW> </THEAD> <TBODY VALIGN="TOP"> <ROW> <ENTRY/> <ENTRY>P<SUB>2</SUB>O<SUB>5</SUB></ENTRY> <ENTRY>3 to 20%</ENTRY> <ENTRY/> </ROW> <ROW> <ENTRY/> <ENTRY>B<SUB>2</SUB>O<SUB>3</SUB></ENTRY> <ENTRY>0 to 5%</ENTRY> </ROW> <ROW> <ENTRY/> <ENTRY>GeO<SUB>2</SUB></ENTRY> <ENTRY>more than 14 to 37%</ENTRY> </ROW> <ROW> <ENTRY/> <ENTRY>Sum of P<SUB>2</SUB>O<SUB>5 </SUB>+ B<SUB>2</SUB>O<SUB>3 </SUB>+ GeO<SUB>2</SUB></ENTRY> <ENTRY>24 to 43%</ENTRY> </ROW> <ROW> <ENTRY/> <ENTRY>Li<SUB>2</SUB>O</ENTRY> <ENTRY>0 to 5%</ENTRY> </ROW> <ROW> <ENTRY/> <ENTRY>Na<SUB>2</SUB>O</ENTRY> <ENTRY>0 to 8%</ENTRY> </ROW> <ROW> <ENTRY/> <ENTRY>K<SUB>2</SUB>O</ENTRY> <ENTRY>0 to 10%</ENTRY> </ROW> <ROW> <ENTRY/> <ENTRY>Sum of Li<SUB>2</SUB>O + Na<SUB>2</SUB>O + K<SUB>2</SUB>O</ENTRY> <ENTRY>1 to 10%</ENTRY> </ROW> <ROW> <ENTRY/> <ENTRY>Nb<SUB>2</SUB>O<SUB>5</SUB></ENTRY> <ENTRY>0 to 50%</ENTRY> </ROW> <ROW> <ENTRY/> <ENTRY>Bi<SUB>2</SUB>O<SUB>3</SUB></ENTRY> <ENTRY>12 to 67%</ENTRY> </ROW> <ROW> <ENTRY/> <ENTRY>BaO</ENTRY> <ENTRY>0 to 5%</ENTRY> </ROW> <ROW> <ENTRY/> <ENTRY>WO<SUB>3</SUB></ENTRY> <ENTRY>0 to 12%</ENTRY> </ROW> <ROW> <ENTRY/> <entry namest="OFFSET" nameend="3" align="center" rowsep="1"/> </ROW> </TBODY> </TGROUP> </TABLE> </TABLES>
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