| 摘要 |
PROBLEM TO BE SOLVED: To obtain an adiabatic electrical insulating body having an adequate strength and a shape in a state held in a container, and having excellent volume resistivity and voltage endurance characteristics. SOLUTION: Sandy material composition is obtained by compounding 100 pts.wt. of an insulating sand with an inorganic bonding agent prepared by mixing boric acid, a metal oxide and boron oxide at a weight ratios in the range of (16-75):(16-60):(0-67) in such an amount that the boric acid becomes 1.0-30 pts.wt. The resulatant composition is heated at 140-500 deg.C to obtain a hardened adiabatic electrical insulating composition. Alternatively, the inorganic bonding agent is further compounded with 0.05-0.8 pt.wt. of a silicone resin to obtain a sandy material composition, and the resultant composition is heated at 140-500 deg.C to obtain a hardened adiabatic electrical insulating composition. |
