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US4650837A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for converting Si-H containing polycarbosilanes to new and useful preceramic polymers and ceramic materials

Assignee: Massachusetts Institute of Technology
•
Filing: 1985-09-30
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Granted: 1987-03-17
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Expires: 2005-09-30
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Abstract

Abstract A method of forming preceramic polymers using a polycarbosilane having repeat units of the formula [RSi(H)--(CH 2 ) q ] (where R is H, a lower alkyl group having from 1 to about 6 carbon atoms, a cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbons atoms, q is an integer 1 or greater), by reacting it with alkali metal silylamides in a weight ratio of polycarbosilane:silylamide of 10:1 or less is disclosed. Preferably, the alkali metal silylamide is a polymeric alkali metal silylamide of the formula [(R 1 SiHNH) a (R 1 SiN) b (R 1 SiHNM) c ] m where a+b+c=1; R 1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted alkenyl group having from 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group; M is an alkali metal or one-half equivalent of an alkaline earth metal; and n and m are integers greater than 1. Novel preceramic polymers formed by this method are also disclosed.

Inventors

  • 👤 Dietmar Seyferth
  • 👤 Yuan-Fu Yu

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 17:23
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/60; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/571; C04B35/622; C04B35/62227; C04B35/62272; C04B35/62277; C04B35/62281; C08L; C08L83/00; C08L83/16; C04B2235/00; C04B2235/65; C04B2235/656; C04B2235/6562; C04B2235/658; C04B2235/6586

Claims Analysis

Total Claims: 68
Claim 1
Independent Claim 136 words
A method for preparing novel preceramic organosilicon polymers, wherein the method comprises: (a) admixing with a silylamide in an organic solvent a polycarbosilane having at least 25 mole % of repeat units of the formula RSi(H)-(CH 2 ) q ]where R is H, a lower alkyl group having from 1 to about 6 carbon atoms, a cycloalkyl group having 3 to about 6 carbon atoms, or a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, and q is an integer 1 or greater, wherein the weight ratio of polycarbosilane: silylamide is about 10:1 or less; (b) allowing the admixture of step (a) to react at room temperature or above; and (c) quenching the reaction mixture with a reactive electrophile, when a metal silylamide is used, thereby forming said organosilicon polymer.
Claim 2
Independent Claim 136 words
A method for preparing novel preceramic organosilicon polymers, wherein the method comprises: (a) admixing with a silylamide in an organic solvent a polycarbosilane having at least 25 mole % of repeat units of the formula RSi(H)-(CH 2 ) q ]where R is H, a lower alkyl group having from 1 to about 6 carbon atoms, a cycloalkyl group having 3 to about 6 carbon atoms, or a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, and q is an integer 1 or greater, wherein the weight ratio of polycarbosilane: silylamide is about 10:1 or less; (b) allowing the admixture of step (a) to react at room temperature or above; and (c) quenching the reaction mixture with a reactive electrophile, when a metal silylamide is used, thereby forming said organosilicon polymer.
Claim 3
Dependent Claim 103 words
The method of claim 1, wherein the metal silylamide has the formula [(R 1 SiHNH) a (R 1 SiN) b (R 1 SiHNM) c ] m , where a+b+C=1, R 1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted alkenyl group having from 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group; M is an alkali metal or one-half equivalent of an alkaline earth metal; and m is an integer greater than 1.
Claim 4
Dependent Claim 12 words
The method of claim 1, wherein R is a lower alkyl group.
Claim 5
Dependent Claim 11 words
The method of claim 3, wherein R is CH 3 .
Claim 6
Dependent Claim 11 words
The method of claim 1, wherein q is 3 or less.
Claim 7
Dependent Claim 9 words
The method of claim 1, where q is one.
Claim 8
Dependent Claim 13 words
The method of claim 2, wherein R 1 is a lower alkyl group.
Claim 9
Dependent Claim 12 words
The method of claim 7, wherein R is a lower alkyl group.
Claim 10
Dependent Claim 12 words
The method of claim 2, wherein R 1 is CH 3 .
Claim 11
Dependent Claim 11 words
The method of claim 9, wherein R is CH 3 .
Claim 12
Dependent Claim 19 words
The method of claim 1 wherein the ratio of polycarbosilane to alkali metal silylamide is about 5:1 or less.
Claim 13
Dependent Claim 13 words
The method of claim 11 wherein the ratio is about 3:1 or less.
Claim 14
Dependent Claim 11 words
The method of claim 11 wherein the ratio is about 1:1.
Claim 15
Dependent Claim 14 words
The method of claim 1, wherein the reaction mixture is quenched with an electrophile.
Claim 16
Dependent Claim 37 words
The method of claim 14, wherein the electrophile is E-X, where E is selected from the group consisting of organic groups and silyl groups and X is selected from the group consisting of halogen, sulfate and sulfonate.
Claim 17
Dependent Claim 17 words
The method of claim 15 wherein the mixture is allowed to react by stirring at room temperature.
Claim 18
Dependent Claim 13 words
The method of claim 15 wherein the mixture is heated above room temperature.
Claim 19
Dependent Claim 18 words
The method of claim 16 wherein the electrophile quenching the reaction is an organic halide or a halosilane.
Claim 20
Dependent Claim 14 words
The method of claim 18 wherein the organic halide is a lower alkyl halide.
Claim 21
Dependent Claim 14 words
The method of claim 19 wherein the lower alkyl halide is CH 3 I.
Claim 22
Dependent Claim 11 words
The method of claim 18 wherein the halosilane is a chlorosilane.
Claim 23
Dependent Claim 15 words
A preceramic polymer containing Si, C and N formed by the method of claim 1.
Claim 24
Dependent Claim 15 words
A preceramic polymer containing Si, C and N formed by the method of claim 2.
Claim 25
Dependent Claim 15 words
A preceramic polymer containing Si, C and N formed by the method of claim 4.
Claim 26
Dependent Claim 111 words
The method of claim 1 wherein the silylamide is [R 2 R 3 R 4 Si] 2 NM wherein R 2 , R 3 and R 4 are each a lower alkyl group having from 1 to about 6 carbon atoms, a lower alkoxy group having from 1 to about 6 carbon atoms, a substituted or unsubstituted vinyl group, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group, R 2 , R 3 and R 4 may be the same or different; and M is an alkali metal or one-half equivalent of an alkaline earth metal.
Claim 27
Dependent Claim 34 words
The method of claim 25 wherein [R 2 R 3 R 4 Si] 2 NM is selected from[(CH 3 ) 2 (CH 2 =CH)Si] 2 NM and [(CH 3 ) 3 Si] 2 NM.
Claim 28
Dependent Claim 118 words
The method of claim 1 wherein the silylamide is partially deprotonated cyclo-[R 5 R 6 SiNH] m containing [R 5 R 6 SiNM] units wherein R 5 and R 6 are each a lower alkyl group having from 1 to about 6 carbon atoms, a lower alkoxy group having from 1 to about 6 carbon atoms, a substituted or unsubstituted vinyl group, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group, R 5 and R 6 may be the same or different; M is an alkali metal or one-half equivalent of an alkaline earth metal and m is an integer greater than 1.
Claim 29
Dependent Claim 29 words
The method of claim 27 wherein cyclo-[R 5 R 6 SiNH] m is selected form [(CH 3 ) 2 SiNH] m and [(CH 3 )(CH 2 =CH)SiN] m .
Claim 30
Dependent Claim 12 words
The method of claim 1 wherein R is a lower aryl group.
Claim 31
Dependent Claim 20 words
The method of claim 1 wherein the silylamide is derived from a diorganocyclopolysilazane that is either partially or completely ring-opened.
Claim 32
Dependent Claim 102 words
The method of claim 30 where the diorganocyclopolysilazane comprises units having the formula R 1 R 11 SiNH] m where R 1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted alkenyl group having from 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri (lower)alkyl or di(lower)alkylsilyl group or a di(lower) alkylsilyl group or a di(lower)alkylamino group; R 11 is defined as is R 1 and may be the same or different, and m is an integer greater than 1.
Claim 35
Dependent Claim 53 words
The method of claim 31 wherein the diorganocyclopolysilazane is reacted with a few mole percent based on available NH groups of a base produce a polymeric silyalamide containing a few mole percent of [R 1 R 11 SiNM] units where M is an alkali metal or one-half equivalent of an alkaline earth metal.
Claim 36
Dependent Claim 15 words
The method of claim 31 wherein R 11 is the same as R 1 .
Claim 37
Dependent Claim 15 words
The method of claim 33 wherein R 11 and R 1 are CH 3 .l
Claim 38
Dependent Claim 10 words
A preceramic polymer formed by the method of claim 10.
Claim 39
Dependent Claim 10 words
A preceramic polymer formed by the method of claim 30.
Claim 40
Dependent Claim 10 words
A preceramic polymer formed by the method of claim 31.
Claim 41
Independent Claim 230 words
A method for preparing an organosilicox preceramic polymer, wherein the method comprises: (a) generating a polysilylamide in the presence of a polycarbosilane of the formula: -[RSi(H)-(CH 2 ) 9 ] n -, where q is an integer 1 or greater; R is H, a lower alkyl group having from 1 to about 6 carbon atoms, a lower cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, and n is an integer greater than 1; wherein the polysilylamide is generated by reacting the ammonolysis product of an R 1 SiHX 2 , where R 1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted alkenyl group having from 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group and X is a halogen, in the presence of a basic catalyst capable of deprotonating the hydrogen from a nitrogen atom adjacent to a silicon atom to generate the polysilylamide in situ; (b) allowing the in situ generated polysilylamide and the polycarbosilane sufficient time to react with each other at room temperature; and (c) quenching the mixture with an organic halide or halosilane to produce the organosilicon preceramic polymer.
Claim 42
Independent Claim 230 words
A method for preparing an organosilicox preceramic polymer, wherein the method comprises: (a) generating a polysilylamide in the presence of a polycarbosilane of the formula: -[RSi(H)-(CH 2 ) 9 ] n -, where q is an integer 1 or greater; R is H, a lower alkyl group having from 1 to about 6 carbon atoms, a lower cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, and n is an integer greater than 1; wherein the polysilylamide is generated by reacting the ammonolysis product of an R 1 SiHX 2 , where R 1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted alkenyl group having from 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group and X is a halogen, in the presence of a basic catalyst capable of deprotonating the hydrogen from a nitrogen atom adjacent to a silicon atom to generate the polysilylamide in situ; (b) allowing the in situ generated polysilylamide and the polycarbosilane sufficient time to react with each other at room temperature; and (c) quenching the mixture with an organic halide or halosilane to produce the organosilicon preceramic polymer.
Claim 43
Dependent Claim 34 words
The method of claim 38 wherein the mixture of in situ generated polysilylamide and polycarbosilane reaction mixture is heated in solution above room temperature for a sufficient time to cause a reaction to occur.
Claim 44
Dependent Claim 11 words
The method of claim 38 wherein R is a lower alkyl.
Claim 45
Dependent Claim 11 words
The method of claim 40, wherein R is CH 3 .
Claim 46
Dependent Claim 16 words
The method of claim 41 wherein R 1 SiHX 2 is CH 3 SiHCl 2 .
Claim 47
Dependent Claim 13 words
The method of claim 38 wherein the organic halide is lower alkyl halides.
Claim 48
Dependent Claim 14 words
The method of claim 43 wherein the lower alkyl halide is CH 3 I.
Claim 49
Dependent Claim 10 words
A preceramic polymer formed by the method of claim 38.
Claim 50
Dependent Claim 10 words
A preceramic polymer formed by the method of claim 43.
Claim 51
Dependent Claim 10 words
A preceramic polymer formed by the method of claim 44.
Claim 52
Dependent Claim 88 words
The method of claim 1 wherein an organopolysilane of the formula (R a SiH) x (R a Si) y ] n , where x+y=1, n is an integer greater than 1 , R a is a lower alkyl group having from about 1 to about 6 carbon atoms, a cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms or a tri(loewr)alkyl- or di(lower)alkylsilyl group is added to create a ternary preceramic polymer.
Claim 53
Dependent Claim 45 words
The method of claim 48 wherein the organopolysilane is added in sufficient quantity so that the excess silicon obtained on pyrolysis of the organopolysilane can react with excess carbon from the pyrolysis of the polycarbosilane and the silylamide, thereby reducing the amount of free carbon.
Claim 54
Dependent Claim 13 words
The method of claim 49 wherein R a is a lower alkyl group.
Claim 55
Dependent Claim 12 words
The method of claim 50 wherein R a is CH 3 .
Claim 56
Dependent Claim 87 words
The method of claim 2 wherein an organopolysilane of the formula [(R a SiH) x (R a Si) y ] n , where x+y=1, n is an integer greater than 1, R a is a lower alkyl group having from about 1 to about 6 carbon atoms, a cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms or a tri(lower)alkyl- or di(lower)alkylsily group is added to create a ternary preceramic polymer.
Claim 57
Dependent Claim 44 words
The method of claim 52 the organopolysilane is added in sufficient quantity so that the excess silicon obtained on pyrolysis of the organopolysilane can react with excess carbon from the pyroysis of the polycarbosilane and the silylamide, thereby reducing the amount of free carbon.
Claim 58
Dependent Claim 13 words
The method of claim 53 wherein R a is a lower alkyl group.
Claim 59
Dependent Claim 12 words
The method of claim 54 wherein R a is CH 3 .
Claim 60
Dependent Claim 87 words
The method of claim 38 wherein an organopolysilane of the formula (R a SiH) x (R a Si) y ] n , where x+y=1, n is an integer greater than 1, R a is a lower alkyl group having from about 1 to about 6 carbon atoms, a cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms or a tri(lower)alkyl- or di(lower)alkylsilyl group is added to create a ternary preceramic polymer.
Claim 61
Dependent Claim 45 words
The method of claim 56 wherein the organopolysilane is added in sufficient quantity so that the excess silicon obtained on pyrolysis of the organopolysilane can react with excess carbon from the pyroysis of the polycarbosilane and the silylamide, thereby reducing the amount of free carbon.
Claim 62
Dependent Claim 13 words
The method of claim 57 wherein R a is a lower alkyl group.
Claim 63
Dependent Claim 12 words
The method of claim 58 wherein R a is CH 3 .
Claim 64
Dependent Claim 10 words
A preceramic polymer formed by the method of claim 48.
Claim 65
Dependent Claim 10 words
A preceramic polymer formed by the method of claim 53.
Claim 66
Dependent Claim 10 words
A preceramic polymer formed by the method of claim 55.
Claim 67
Dependent Claim 10 words
A preceramic polymer formed by the method of claim 57.
Claim 68
Dependent Claim 10 words
A preceramic polymer formed by the method of claim 59.
Claim 69
Dependent Claim 17 words
The method of claim 25, wherein the substituted vinyl group is a substituted or unsubstituted allyl group.
Claim 70
Dependent Claim 17 words
The method of claim 27, wherein the substituted vinyl group is a substituted or unsubstituted allyl group.

References Cited (Backward Citations)

US4404153A Cited
US4395460A Cited

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