Process for the preparation of polymetallo(disily)silazane polymers and the polymers therefrom

A process for preparing an R.sub.3 'SiNH-containing metallosilazane polymer, which process consists of contacting and reacting in an inert, essentially anhydrous atmosphere, a chlorine-containing disilane or a mixture of chlorine-containing disilanes of the general formula

• (Cl.sub.a R.sub.b Si).sub.2,
• a disilazane having the general formula
• (R.sub.3 'Si).sub.2 NH,
• and a metal halide at a temperature in the range of 25.degree. C. and the boiling point of said metal halide and thereafter removing byproduced volatile products by distillation at a temperature of less than 300.degree. C., wherein
• R is a vinyl radical, an alkyl radical containing 1-3 carbon atoms, or a phenyl radical;
• R' is a vinyl radical, a hydrogen radical, an alkyl radical containing 1-3 carbon atoms, or a phenyl radical;
• a has a value of 0.5-3;
• b has a value of 0-2.5;
• the sum of (a +b) is equal to three;
• the metal atom of said metal halide is selected from the group consisting of boron, phosphorous, and titanium;
• said metal halide is a liquid at the reaction temperature;
• and
• the boiling point of said metal halide is less than 300.degree. C.

A process for preparing a ceramic material which consists of heating an R.sub.3 'SiNH-containing metallosilazane in an inert atmosphere or in a vacuum to at least a temperature of 750.degree. C. until the R.sub.3 'SiNH-containing metallosilazane polymer is converted to ceramic material, which R.sub.3 'SiNH-containing metallosilazane polymer is obtained by a process which consists of contacting and reacting in an inert, essentially anhydrous atmosphere, a chlorine-containing, disilane or a mixture of chlorine-containing disilanes, wherein the number of diorgano-substituted silicon atoms does not exceed the number of monoorgano-substituted silicon atoms, of said disilanes having the general formula

• (Cl.sub.a R.sub.b Si).sub.2,
• a disilazane having the general formula
• (R.sub.3 'Si).sub.2 NH,
• and a metal halide at a temperature in the range of 25.degree. C. to 300.degree. C. while distilling byproduced volatile products, wherein
• R is a vinyl radical, an alkyl radical containing 1-3 carbon atoms, or a phenyl radical;
• R' is a vinyl radical, a hydrogen radical, an alkyl radical containing 1-3 carbon atoms, or a phenyl radical;
• a has a value of 0.5-3;
• b has a value of 0-2.5;
• the sum of (a+b) is equal to three;
• the metal atom of said metal halide is selected from the group consisting of boron, phosphorous, and titanium;
• said metal halide is a liquid at the reaction temperature;
• and
• the boiling point of said metal halide is less than 300.degree. C.

A process for preparing an R.sub.3 'SiNH-containing metallosilazane polymer, which process consists of contacting and reacting in an inert, essentially anhydrous atmosphere, a disilazane having the general formula

• (R.sub.3 'Si).sub.2 NH,
• and a metal halide with
• (i) a mixture of a chlorine-containing disilane having the general formula
• (Cl.sub.a R.sub.b Si).sub.2
• and a chlorine-containing monosilane having the general formula
• R.sub.n 'SiCl.sub.4-n,
• (ii) a mixture of chlorine-containing disilanes having the general formula
• (Cl.sub.a R.sub.b Si).sub.2
• mixed with a chlorine-containing monosilane having the general formula
• R.sub.n 'SiCl.sub.4-n,
• or (iii) a mixture of chlorine-containing disilanes having the general formula
• (Cl.sub.a R.sub.b Si).sub.2
• mixed with a mixture of chlorine-containing monosilanes having the general formula
• R.sub.n 'SiCl.sub.4-n
• at a temperature in the range of 25.degree. C. to 300.degree. C. while distilling byproduced volatile products, wherein
• R is a vinyl radical, an alkyl radical containing 1-3 carbon atoms, or a phenyl radical;
• R' is a vinyl radical, a hydrogen radical, an alkyl radical containing 1-3 carbon atoms, or a phenyl radical;
• a has a value of 0.5-3;
• b has a value of 0-2.5;
• the sum of (a+b) is equal to three;
• n has a value of 1 or 2;
• the metal atom of said metal halide is selected from the group consisting of boron, phosphorous, and titanium;
• said metal halide is a liquid at the reaction temperature;
• and
• the boiling point of said metal halide is less than 300.degree. C.

A method for preparing a ceramic article which consists of

• (A) forming an article of the desired shape from an R.sub.3 'SiNH-containing metallosilazane polymer;
• (B) heating the article prepared in (A) in an inert atmosphere or in a vacuum to an elevated temperature of at least 750.degree. C. until the metallosilazane polymer is converted to a ceramic, which metallosilazane polymer is obtained by a process which consists of containing and reacting in an inert, essentially anhydrous atmosphere, a chlorine-containing disilane or a mixture of chlorine-containing disilanes, wherein the number of diorgano-substituted silicon atoms does not exceed the number of monoorgano-substituted silicon atoms of the general formula
• (Cl.sub.a R.sub.b Si).sub.2,
• a disilazane having the general formula
• (R.sub.3 'Si).sub.2 NH,
• and a metal halide selected from the group consisting of BBr.sub.3, TiCl.sub.4, and PCl.sub.3 at a temperature in the range of 125.degree. C. to 300.degree. C. while distilling byproduced volatile products, wherein
• R is a vinyl radical, an alkyl radical containing 1-3 carbon atoms, or a phenyl radical;
• R' is a vinyl radical, a hydrogen radical, an alkyl radical containing 1-3 carbon atoms, or a phenyl radical;
• a has a value of 0.5-3;
• b has a value of 0-2.5;
• the sum of (a+b) is equal to three;
• and
• the metal halide is present in such amounts so that the resulting metallosilazane polymer contains 0.05 to 10.0 weight percent of said metal atom.