Polysilane precursors containing olefinic groups for silicon carbide

Claim 2

A thermoplastic organosilicon polymer that is prepared in a medium in which it is soluble which primarily is comprised of units of the formula wherein R is hydrogen or an alkyl, aryl or aralkyl group containing from one to ten carbon atoms,preferably methyl or hydrogen, R' is an alkenyl group containing from two to eight carbon atoms, preferably vinyl, n is zero or an integer, preferably zero, z is at least one, preferably less than or equal to two, x+y+z is equal to four, a is equal to or greater than five, at least 5 %, preferably at least 10 %, of the silicon valences of the total polymer are satisfied by R' groups and wherein R, R', x, y, z and n may vary from unit to unit within the polymer.

Claim 3

The thermoplastic organosilicon polymer of claim 1 which primarily is comprised of units of the formula wherein R is hydrogen or methyl, R' is vinyl, the sum x + y is at least two but no more than three, a is equal to or greater than five and at least 10% of the silicon valences of the total polymer are satisfied by R' groups.

Claim 4

A process for preparing the thermoplastic organosilicon polymer of claim 1 or 2 which comprises reacting at least one olefinic silane monomer of the general formula: wherein R, R', n, z, x+y+z and x + y are defined as above, y is at least one and X is a halogen, preferably chlorine; with or without other silane monomers of the same general formula where y=0, with a sodium metal in the presence of an inert solvent or solvent mixture. wherein such a solvent or solvent mixture has a reflux temperature above the melting point of the sodium metal and such that at least 5%, preferably at least 10 % of the silicon valences of the resulting polymer are satisfied by R' groups.

Claim 5

4 . The process of claim 3 wherein R is methyl, R ' is vinyl, n=o and X is chlorine and z is two.

Claim 6

The process of claim 3 or 4 wherein the solvent is a blend of a non-protic ether and an aromatic or a non-aromatic hydrocarbon respectively.

Claim 7

The process of claim 5 wherein the non-protic ether is selected from the group consisting of tetrahydrofuran, dioxane, monoglyme and diglyme, the aromatic hydrocarbon is toluene or xylene and the non-aromatic hydrocarbon is octane.

Claim 8

The process of claim 5 or 6 wherein the solvent is a blend of tetrahydrofuran and toluene or xylene respectively.

Claim 9

The process of any one of claims 3 to 7 wherein the temperature is between 98°C and 150°C.

Claim 10

The process of anyone of claims 3 to 8 wherein in at least one monomer y = 1 and z = 1.

Claim 11

The process of anyone of claims 3 to 8 and 9 wherein at least one olefinic silane monomer is either CH 2 =CHSi(CH 3 )Cl 2 or CH 2 CHSi(CH 3 ) 2 Cl, and at least one non-olefinic silane monomer is selected from the group consisting of (CH 3 ) 3 SiCl. (CH 3 ) 2 SiCl 2 , (CH 3 ) 2 SiHCl, CH 3 SiHCl 2 . ClCH 2 Si(CH 3 ) 2 Cl, and (CH 3 ) 3 SiCH 2 Cl.

Claim 12

The process of anyone of claims 1 to 10 wherein the monomers reacted are (CH 3 ) 3 SiCl and CH 2 =CHSi(CH 3 )Cl 2 in a 2:1 or 1.5:1 or 1:1 molar ratio respectively.

Claim 13

The process of anyone of claims 3 to 10 wherein the monomers reacted are (CH 3 ) 3 SiCl; CH 3 SiHC1 2 and CH 2 =CHSi(CH 3 )Cl 2 in a 1.0:0.3:1.0 molar ratio respectively.

Claim 14

The process of anyone of claims 3 to 10 wherein the monomers reacted are (CH 3 ) 3 SiCl, (CH 3 ) 2 SiCl 2 and CH 2 =CHSi(CH 3 )Cl 2 in a 0.5:0.5:1.0 or 0.5:1.0:1.0 molar ratio respectively.

Claim 15

The process of anyone of claims 3 to 10 wherein the monomers reacted are (CH 3 ) 2 SiCl 2 and CH 2 =CHSi(CH 3 )Cl 2 in a molar ratio of 1:1.

Claim 16

The process of anyone of claims 1 to 10 wherein the monomers reacted are ClCH 2 Si(CH 3 ) 2 Cl and CH 2 =CHSi(CH 3 )C1 2 in a 1:1 molar ratio.

Claim 17

The process of anyone of claims 1 to 10 wherein the monomers reacted are CH 2 =CHSi(CH 3 ) 2 Cl, (CH 3 ) 2 SiCl 2 and CH 2 =CHSi(CH 3 )Cl 2 in a 1:1:1 molar ratio.

Claim 18

A process for converting the organosilicon polymers of claim 1 to silicon carbide by pyrolysis an inert atmosphere or vacuum.

Claim 19

A process for preparing a thermoplastic organosilicon polymer in a medium in which it is soluble which primarily is comprised of units of the formula wherein R is hydrogen or an alkyl, aryl or aralkyl group containing from one to ten carbon atoms, preferably methyl or hydrogen, R' is an alkenyl group containing from two to eight carbon atoms, preferably vinyl, n is zero or an integer, preferably zero, z is zero or at least one and preferably less than or equal to two,x+y+z is equal to four, a is equal to or greater than five, at least 5 % and preferably at least 10 % of the silicon valences of the total polymer are satisfied by R' groups and wherein R, R', x, y, z and n may vary from unit to unit within the polymer, which comprises reacting at least one olefinic silane monomer of the general formula: wherein R, R', n, z and x+y+z are defined as above, x is a halogen, preferably chlorine and y is at least one, with or without other silane monomers of the same general formula where y= O , with a sodium metal in the presence of an inert solvent or solvent mixture, wherein such a solvent or solvent mixture has a reflux temperature above the melting point of the sodium metal and such that at least 5%, preferably at least 10 % of the silicon valences of the resulting polymer are satisfied by R' groups.

Claim 20

A process for preparing a thermoplastic organosilicon polymer in a medium in which it is soluble which primarily is comprised of units of the formula wherein R is hydrogen or an alkyl, aryl or aralkyl group containing from one to ten carbon atoms, preferably methyl or hydrogen, R' is an alkenyl group containing from two to eight carbon atoms, preferably vinyl, n is zero or an integer, preferably zero, z is zero or at least one and preferably less than or equal to two,x+y+z is equal to four, a is equal to or greater than five, at least 5 % and preferably at least 10 % of the silicon valences of the total polymer are satisfied by R' groups and wherein R, R', x, y, z and n may vary from unit to unit within the polymer, which comprises reacting at least one olefinic silane monomer of the general formula: wherein R, R', n, z and x+y+z are defined as above, x is a halogen, preferably chlorine and y is at least one, with or without other silane monomers of the same general formula where y= O , with a sodium metal in the presence of an inert solvent or solvent mixture, wherein such a solvent or solvent mixture has a reflux temperature above the melting point of the sodium metal and such that at least 5%, preferably at least 10 % of the silicon valences of the resulting polymer are satisfied by R' groups.

Claim 21

The process of claim 1 wherein the thermoplastic organosilicon polymer primarily is comprised of units of the formula wherein R is hydrogen or methyl, R' is vinyl, the sum x + y is at least two but no more than three, a is equal to or greater than five and at least 10% of the silicon valences of the total polymer are satisfied by R' groups.

Claim 22

The process of claim 1 or 2 wherein R is methyl, R' is vinyl, n=0 and X is chlorine and z is two.

Claim 23

The process of anyone of claims 1 to 3 wherein the solvent is a blend of nonprotic ether and an aromatic or an nonaromatic hydrocarbon respectively.

Claim 24

The process of claim 4 wherein the non-protic ether is selected from the group consisting of tetrahydrofuran, dioxane, monoglyme and diglyme, the aromatic hydrocarbon is toluene or xylene and the non-aromatic hydrocarbon is octane.

Claim 25

The process of claim 4 or 5 wherein the solvent is a blend of tetrahydrofuran and toluene or xylene respectively.

Claim 26

The process of anyone of claims 1 to 6 wherein the temperature is between 98°C and 150°C.

Claim 27

The process of anyone of claims 1 to 7 wherein in at least one monomer y = 1 and z = 1.

Claim 28

The process of anyone of claims 1 to 7 and 8 wherein at least one olefinic silane monomer is either CH 2 =CHSi(CH 3 )Cl 2 or CH 2 CHSi(CH 3 ) 2 Cl, and at least one non-olefinic silane monomer is selected from the group consisting of (CH 3 ) 3 SiCl, (CH 3 ) 2 SiCl 2 , (CH 3 ) 2 SiHCl, CH 3 SiHCl 2 , ClCH 2 Si(CH 3 ) 2 Cl, and (CH 3 ) 3 SiCH 2 Cl.

Claim 29

The process of anyone of claims 1 to 9 wherein the monomer reacted are (CH 3 ) 3 SiCl and CH 2 =CHSi(CH 3 )Cl 2 in 2:1 or 1.5:1 or 1:1 molar ratio respectively.

Claim 30

The process of anyone of claims 1 to 9 wherein the monomers reacted are (CH 3 ) 3 SiCl; CH 3 SiHCl 2 and CH 2 =CHSi(CH 3 )Cl 2 in a 1.0:0.3:1.0 molar ratio respectively.

Claim 31

The process of anyone of claims 1 to 9 wherein the monomers reacted are (CH 3 ) 3 SiCl, ( CH 3 ) 2 SiC1 2 and CH 2 =HSi(CH 3 )Cl 2 in a 0.5:0.5:1.0 or 0.5:1.0:1.0 molar ratio respectively.

Claim 32

The process of anyone of claims 1 to 9 wherein the monomers reacted are (CH 3 ) 2 SiCl 2 and CH 2 =CHSi(CH 3 )Cl 2 is a molar ratio of 1:1.

Claim 33

The process of anyone of claims 1 to 9 wherein the monomers reacted are ClCH 2 Si(CH 3 ) 2 Cl and CH 2 =CHSi(CH 3 )Cl 2 in a 1:1 molar ratio.

Claim 34

The process of anyone of claims 1 to 9 wherein the monomers reacted are CH 2 =CHSi(CH 3 ) 2 C l, (CH 3 ) 2 SiCl 2 and CH 2 =CHSi(CH 3 )Cl 2 in a 1:1:1 molar ratio.

Claim 35

A process for converting the organosilicon polymers, prepared as claimed in anyone of claims 1 to 15 to silicon carbide by pyrolysis in an inert atmosphere or vacuum.