| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a glass composition containing no lead and no bismuth, having a relatively low heat expansion coefficient and a softening point, and being excellent in chemical resistance. <P>SOLUTION: The lead-free and bismuth-free glass composition satisfies following conditions: (1) the composition contains (a) 0.1-5 wt.% of SiO<SB>2</SB>, (b) 26-60 wt.% of B<SB>2</SB>O<SB>3</SB>, (c) 30-60 wt.% of ZnO, (d) the total of 0.1-5 wt.% of at least one kind selected from Li<SB>2</SB>O, Na<SB>2</SB>O and K<SB>2</SB>O, and (e) 0.1-3 wt.% of Al<SB>2</SB>O<SB>3</SB>; (2) the ratio, ZnO/B<SB>2</SB>O<SB>3</SB>, is 0.5-2; and (3) a heat expansion coefficient at 50-350°C is at most 65×10<SP>-7</SP>/°C. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
