Flaky β-silicon carbide and ceramics having laminar structure produced therefrom

Claim 2

Flaky β-SiC having a flaky shape with a thickness of 10 to 100μ and a width and length of 100μ to 10 mm., said flaky β-SiC being obtained from an organic silicon polymer or a mixture of organic silicon polymers containing the carbon and silicon atoms as the major skeletal components, each of said polymers including at least one of the following unit structures (I)-(IV): ##STR2## wherein R 1 is --CH 3 , and R 2 , R 3 and R 4 are one or more members selected from the group consisting of hydrogen, alkyl, aryl, (CH 3 ) 2 CH--, (C 6 H 5 ) 2 SiH--and (CH 3 ) 3 Si--; k, l, m and n are the respective numbers of repetition of the unit structures defined by the immediately preceding parentheses or brackets and k=1-80, l=15-350, m=1-80, and n=15-350, the average molecular weight of the polymer being in the range of 800-20000; M is a metallic or nonmetallic element comprising Si, B, Ti, Fe, Al, Zr or Cr; and R 5 , R 6 , R 7 and R 8 are one or more members selected from the group consisting of hydrogen, alkyl, aryl, (CH 3 ) 2 CH--, (C 6 H 5 ) 2 SiH-- and (CH 3 ) 3 Si--, and any one or more of R 5 , R 6 , R 7 and R 8 may be absent depending on the valence of M and the unit structure.

Claim 3

Ceramics of non-oxide system having a laminar structure and being provided from flaky β-SiC as the starting material, said flaky β-SiC having a flaky shape with a thickness of 10 to 100μ and a width and length of 100μ to 10 mm and being obtained from an organic silicon polymer or a mixture of organic silicon polymers containing the carbon and silicon atoms as the major skeletal components, each of said polymers including at least one of the following unit structures (I)-(IV): ##STR3## wherein R 1 is --CH 3 , and R 2 , R 3 and R 4 are one or more members selected from the group consisting of hydrogen, alkyl, aryl, (CH 3 ) 2 CH--, (C 6 H 5 ) 2 SiH-- and (CH 3 ) 3 Si--; k, l, m and n are the respective numbers of repetition of the unit structures defined by the immediately preceding parentheses or brackets and k=1-80, l=15-350, m=1-80, and n=15-350, the average molecular weight of the polymer being in the range of 800-20000; M is a metallic or nonmetallic element comprising Si, B, Ti, Fe, Al, Zr or Cr; and R 5 , R 6 , R 7 and R 8 are one or more members selected from the group consisting of hydrogen, alkyl, aryl, (CH 3 ) 2 CH--, (C 6 H 5 ) 2 SiH-- and (CH 3 ) 3 Si--, and any one or more of R 5 , R 6 , R 7 and R 8 may be absent depending on the valence of M and the unit structure.

Claim 4

Ceramics of non-oxide system having a laminar structure and being provided from flaky β-SiC as the starting material, said flaky β-SiC having a flaky shape with a thickness of 10 to 100μ and a width and length of 100μ to 10 mm and being obtained from an organic silicon polymer or a mixture of organic silicon polymers containing the carbon and silicon atoms as the major skeletal components, each of said polymers including at least one of the following unit structures (I)-(IV): ##STR3## wherein R 1 is --CH 3 , and R 2 , R 3 and R 4 are one or more members selected from the group consisting of hydrogen, alkyl, aryl, (CH 3 ) 2 CH--, (C 6 H 5 ) 2 SiH-- and (CH 3 ) 3 Si--; k, l, m and n are the respective numbers of repetition of the unit structures defined by the immediately preceding parentheses or brackets and k=1-80, l=15-350, m=1-80, and n=15-350, the average molecular weight of the polymer being in the range of 800-20000; M is a metallic or nonmetallic element comprising Si, B, Ti, Fe, Al, Zr or Cr; and R 5 , R 6 , R 7 and R 8 are one or more members selected from the group consisting of hydrogen, alkyl, aryl, (CH 3 ) 2 CH--, (C 6 H 5 ) 2 SiH-- and (CH 3 ) 3 Si--, and any one or more of R 5 , R 6 , R 7 and R 8 may be absent depending on the valence of M and the unit structure.