To obtain inorg. fibers for reinforcement having superior oxidation resistance by forming C/B/Si inorg. coatings consisting of C, B and Si in a specified atomic ratio on the surfaces of inorg. fibers.
Polysilazane having repeating units represented by the formula (where each of R1-R3 is H, N, C, Si or hydrocarbon) and a number average mol.wt. of about 100-500,000 is spun and fired to produce inorg. fibers such as Si3N4 fibers. These fibers are fed into a chemical vapor deposition device after a deposit is removed by firing in inert gas. Gaseous starting materials such as methane, BCl3 and SiCl4 are fed at a prescribed rate each into the device under heating at about 1,000-1,400°C, carrier gas such as H2+N2 is allowed to flow and the inorg. fibers are passed through the device in about 1hr. During the passing, chemical vapor deposition is carried out to obtain the objective inorg. fibers for reinforcement with C/B/Si coatings formed on the surfaces in about 1nm to 1μm thickness. In the compsn. of the coatings, the atomic ratio of C:B:Si is (0.1-0.99):(0.01-0.8):(0.001-0.5).
SATO KIYOSHI
TEZUKA ATSUSHI
FUNAYAMA TORU
KAWAMURA NORIAKI
TONEN CORP
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