Method for producing ceramic products

摘要

PCT No. PCT/JP93/01730 Sec. 371 Date Jul. 25, 1994 Sec. 102(e) Date Jul. 25, 1994 PCT Filed Nov. 26, 1993 PCT Pub. No. WO94/12448 PCT Pub. Date Jun. 9, 1994.Repetition of a process of impregnating a metal fiber or ceramic fiber preform or porous ceramic with (3) a mixture of polysilazane-type polymers with a number average molecular weight of 200-3000 and a viscosity adjusted to 100 Pa.s or lower at the impregnation temperature, prepared by mixing (1) one or more types of polysilazane-type polymers with a number average molecular weight of 200-3000 and a viscosity of less than 1 Pa.s at the impregnation temperature with (2) one or more types of polysilazane-type polymers with a number average molecular weight of 200-100,000 and having a viscosity of 1 Pa.s or higher or solid at the impregnation temperature, which are selected from polysilazanes whose main repeating unit is -[(SiH2)n(NH)r]- (where n and r are 1, 2 or 3), and copolymers, modified polymers and crosslinked polymers based thereon, and performing crosslinking curing and then firing, is performed for its conversion into a ceramic. The above polysilazane may be, for example, an inorganic polysilazane, an inorganic polysiloxazane, a polyorgano(hydro)silazane, a modified polysilazane or a polymetallosilazane. By performing the CVD coating before or after said process of impregnation, curing and firing, delamination of the fibers may be minimized.