Preparation of polysilazane polymers and the polymers therefrom

Claim 2

A process of preparing a polysilazane polymer, said process chracterized in that it consists of contacting and reacting in an inert, essentially anhydrous, atmosphere, at a temperature in the range of 25°C to 370°C (A) ammonia and (B) chlorine-containing disilanes selected from the group consisting of (i) a chlorine-containing disilane having the general formula [Cl a R b Si l 2 and (ii) a mixture of chlorine-containing disilanes having the general formula [Cl c R d Si] 2 wherein a has a value of 1.5-2.0; b has a value of 1.0-1.5; the ratio of c to d is in the range of 1:1 to 2:1, the sum of a + b is equal to three; the sum of c + d is equal to three; and R in each case is selected from the group consisting of the vinyl group, alkyl radicals of 1-3 carbon atoms and the phenyl group.

Claim 3

The polysilazane polymer produced by the process of claim 1.

Claim 4

A method of preparing a silicon carbide ceramic material which consists of heating a polysilazane polymer prepared according to the process of claim 1, in an inert atmosphere or in a vacuum to at least a temperature of 750°C until the polysilazane polymer is.converted to silicon carbide ceramic material.

Claim 5

A method of preparing a silicon carbide containing ceramic article which consists of (A) forming an article of the desired shape from a polysilazane polymer prepared according to the process of claim 1; (B) heating the article formed in (A) in an inert atmosphere or in a vacuum to an elevated temperature of at least 750°C until the polysilazane polymer is converted to silicon carbide containing ceramic.

Claim 6

A process for preparing a polysilazane polymer, said process characterized in that it consists of contacting and reacting in an inert, essentially anhydrous atmosphere at a temperature in the range of 25°C to 370°C, (A) ammonia and (B) a mixture of chlorine-containing disilanes and monosilanes selected from the group consisting essentially of (i) a mixture of a chlorine-containing disilane and a monosilane, (ii) a mixture of a chlorine-containing disilane and a mixture of monosilanes and (iii) a mixture of chlorine-containing disilanes mixed with a mixture of monosilanes, wherein the chlorine-containing disilanes have the general formula (ClaRbSi)2 and wherein the monosilanes in each case have the general formula R' n SiCl 4-n , wherein R is a vinyl group, an alkyl radical of 1-3 carbon atoms or the phenyl group; R' is vinyl, hydrogen, an alkyl group of 1-3 carbon atoms or the phenyl group; a has a value of 1.5-2.0; b has a value of 1.0-1.5; the sum of a + b is equal to three and n has a value of 0, 1, or 3.

Claim 7

A process for preparing a polysilazane polymer, said process characterized in that it consists of contacting and reacting in an inert, essentially anhydrous atmosphere at a temperature in the range of 25°C to 370°C, (A) ammonia and (B) a mixture of chlorine-containing disilanes and monosilanes selected from the group consisting essentially of (i) a mixture of a chlorine-containing disilane and a monosilane, (ii) a mixture of a chlorine-containing disilane and a mixture of monosilanes and (iii) a mixture of chlorine-containing disilanes mixed with a mixture of monosilanes, wherein the chlorine-containing disilanes have the general formula (ClaRbSi)2 and wherein the monosilanes in each case have the general formula R' n SiCl 4-n , wherein R is a vinyl group, an alkyl radical of 1-3 carbon atoms or the phenyl group; R' is vinyl, hydrogen, an alkyl group of 1-3 carbon atoms or the phenyl group; a has a value of 1.5-2.0; b has a value of 1.0-1.5; the sum of a + b is equal to three and n has a value of 0, 1, or 3.