| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat insulating material that suppresses an increase in thermal conductivity to maintain excellent thermal insulation properties even at a high temperature of 1,500°C or more, and is excellent in heat-resisting properties at 1,700°C or more.SOLUTION: In a heat insulating material made of a porous sintered body comprising MgAlOand having a porosity of not less than 60% and less than 73%, pores having a pore size of not less than 0.8 μm and less than 10 μm occupy not less than 70 vol% and less than 90 vol% of the total pore volume and pores having a pore size of not less than 0.01 μm and less than 0.8 μm occupy not less than 10 vol% and less than 20 vol% of the total pore volume, and the thermal conductivity at 1,000°C or more and 1500°C or less is made not to exceed 1.5 times the thermal conductivity at not less than 20°C and less than 1,000°C.SELECTED DRAWING: None |
