| 摘要 |
<p>A ceramic material composition comprising from 20 to 50 mass% of a borosilicate glass powder, from 25 to 55 mass% of an alumina filler powder and from 10 to 45 mass% of a filler powder (a high refractive index filler powder) having a refractive index higher than the alumina filler powder, wherein the borosilicate glass powder comprises, as calculated as oxides, from 30 to 70 mass% of SiO<Sub>2</Sub>, from 5 to 28 mass% of B<Sub>2</Sub>O<Sub>3</Sub>, from 5 to 30 mass% of Al<Sub>2</Sub>O<Sub>3</Sub>, from 3 to 35 mass% of CaO, from 0 to 25 mass% of SrO, from 0 to 25 mass% of BaO, from 0 to 10 mass% of Na<Sub>2</Sub>O, from 0 to 10 mass% of K<Sub>2</Sub>O, from 0.5 to 10 mass% of Na<Sub>2</Sub>O+K<Sub>2</Sub>O and from 3 to 40 mass% of CaO+SrO+BaO, and satisfies the following conditions:
in the borosilicate glass powder, as represented by mass%, the value of "three times the B<Sub>2</Sub>O<Sub>3</Sub> content" + "twice (the CaO content+the SrO content+the BaO content)" + "ten times (the Na<Sub>2</Sub>O content+the K<Sub>2</Sub>O content)", is within a range of from 105 to 165.</p> |
