Process for reducing the content of boron compounds in halosilane-containing compositions

Patent metadata

Field	Value
Publication number	US-2022017546-A1
Application number	US-201817294455-A
Country	US
Kind code	A1
Filing date	Dec 7, 2018
Priority date	Dec 7, 2018
Publication date	Jan 20, 2022
Grant date	—

Abstract

The content of boron compounds in a composition containing at least one halosilane is reduced by bringing the composition into contact with at least one phenylsilane and removing the at least one halosilane. The invention further relates to the use of phenylsilanes for removing boron compounds from halosilane-containing compositions.

First claim

1 .- 16 . (canceled)

17 . A method for reducing the content of boron compounds in a composition containing at least one halosilane, comprising the steps of
a) bringing the composition into contact with at least one phenylsilane, b) removing the at least one halosilane by means of a thermal separation method, wherein the phenylsilane is selected from the group consisting of the phenylsilanes of formulae A, B, C, and D, and mixtures thereof

wherein R 1 , R 2 , R 3 each individually, are H, alkyl, F, Cl, Br, I, R 5 , or OR 5 , where R 5 each individually is alkyl, aryl, or polyether, and
R 4 each individually is H, alkyl, aryl, F, Cl, Br, or I.

18 . The method of claim 17 , wherein
R 4 ═H and R 1 , R 2 , R 3 each individually are H, Cl, Me, Et, or Ph.

19 . The method of claim 17 , wherein at least one phenylsilane is selected from the group consisting of the phenylsilanes A1, A2, A3, A4, A5 and A6.

20 . The method of claim 17 , wherein the thermal separation method comprises a distillation.

21 . The method of claim 17 , wherein the halosilane removed in step b) has a boron content of less than 1 ppmw.

22 . The method of claim 17 , wherein the halosilane removed in step b) has a boron content of less than 0.1 ppmw.

23 . The method of claim 17 , wherein the halosilane removed in step b) has a boron content of less than 0.01 ppmw.

24 . The method of claim 17 , wherein the boiling point of the phenylsilane is above 145° C.

25 . The method of claim 17 , wherein the boiling point of the phenylsilane is above 145° C. to 250° C.

26 . The method of claim 17 , wherein the boiling point of the phenylsilane is above 150 to 201° C.

27 . The method of claim 17 , wherein the phenylsilane is used in an amount of 1 ppmw to 5% by weight, based on the amount of chlorosilane.

28 . The method of claim 17 , wherein the phenylsilane is used in an amount of 100 ppmw to 3% by weight, based on the amount of chlorosilane.

29 . The method of claim 17 , wherein the phenylsilane is used in an amount of 1 ppmw to 1% by weight, based on the amount of chlorosilane.

30 . The method of claim 17 , wherein step a) is carried out at a temperature of −80 to 600° C.

31 . The method of claim 17 , wherein step a) is carried out at a temperature of −40 to 350° C.

32 . The method of claim 17 , wherein step a) and/or step b) is carried out continuously.

33 . The method of claim 17 , wherein halosilane comprises chlorosilanes of formulae H n SiCl 4-n , H m Cl 6-m Si 2 , (CH 3 ) n SiCl 4-n where n=1-4 and m=0-4, (CH 3 ) n H m SiCl 4-n-m where n=0-4 and m=0, 1, and Me n Si 2 Cl 6-n where n=1-6.

34 . The method of claim 17 , wherein the boron compounds are halogen compounds of boron.

35 . The method of claim 17 , wherein the composition is a product stream from the production of chlorosilane by the process of low-temperature conversion, high-temperature conversion or hydrochlorination, or is a product stream from the production of organochlorosilane by the Müller-Rochow process.

36 . The method of claim 17 , wherein steps a) and b) are incorporated into an integrated system for the production of polycrystalline silicon or into an integrated system for the production of silicones.

37 . A process for removing boron compounds from compositions containing at least one halosilane comprising employing at least one phenylsilanes of formulae A, B, C or D

38 . The process of claim 37 , wherein R 4 each individually is H or R 1 , and R 2 , R 3 each individually are H, Cl, Me, Et, or Ph.

39 . The process of claim 37 , wherein at least one phenylsilane is selected from the group consisting of the phenylsilanes A1, A2, A3, A4, A5 and A6.

Assignees

• Wacker Chemie Ag

Inventors

• Rimboeck Karl-Heinz

Classifications

• C07F7/20 Primary

  Purification, separation · CPC title

• C01B33/10742

  prepared by hydrochlorination of silicon or of a silicon-containing material · CPC title

• C07F5/02

  Boron compounds · CPC title

• C01B33/10778 Primary

  Purification · CPC title