| 摘要 |
PROBLEM TO BE SOLVED: To provide a ceramic roll for corona discharge treatment in which the cracking and peeling of an insulating layer are hard to occur in roll production or a use excellent in insulating properties and having durability. SOLUTION: The surface of a roll made of a metal is subjected to blasting and is thereafter thermal-sprayed with a metal to form a substrate 2, the surface of the substrate 2 is thermal-sprayed with metallic oxide to form a porous layer 3 in such a manner that at least the lower porous layer at least bonded to the substrate has 3 to 6% porosity and 0.2 to 1.0 mm thickness, the upperporous layer has 5 to 12% porosity and 0.3 to 2.5 mm thickness, and the porosity of the upper porous layer is higher than that of the lower porous layer, next, the pores in the porous layer are filled with a sealing treating agent, and the sealing treating agent is subjected to hardening treatment to form a sealing material 4 of metallic oxide having electric insulating properties. |
