| 摘要 |
In a spark plug insulator for use in an internal combustion engine, a sintered body has boron nitride and a metal oxide, the boron nitride of the sintered body being 80 % or exceeding 80 % by weight, and the sintered body having a thermal expansion coefficient of less than 5.0 x 10-<6>/ DEG C. The metal oxide is selected alone or combination from the group consisting of magnesium oxide, calcium oxide, silicon oxide, boron oxide, yttrium oxide and aluminum oxide. <IMAGE> |
