Title:
METHOD FOR PRODUCING PURIFIED TRICHLOROSILANE
Document Type and Number:
WIPO Patent Application WO/2023/243466
Kind Code:
A1
Abstract:
[Problem] To greatly reduce, in trichlorosilane that serves as a raw material for the production of polycrystalline silicon or the like, the concentration of dimethyldichlorosilane and isopentane, which are impurities having similar boiling points to said trichlorosilane.
[Solution] Provided is a method for producing purified trichlorosilane, the method being characterized by, at least: supplying crude trichlorosilane containing isopentane and methyldichlorosilane to a first distillation column; carrying out distillation purification in a manner so as to discharge a low boiling point range fraction in which the concentration of isopentane is at least 150 times higher than the concentration of isopentane in the crude trichlorosilane; removing trichlorosilane having a lowered isopentane concentration from the bottom of the column, then supplying the obtained trichlorosilane having a lowered isopentane concentration to a second distillation column; carrying out distillation purification in a manner so as to discharge a high boiling point range fraction in which the concentration of methyldichlorosilane is at least 1.5 times higher than the concentration of methyldichlorosilane in the crude trichlorosilane; and distilling off purified trichlorosilane having a lowered methyldichlorosilane concentration from the top of the column.
Inventors:
SAKAI JUNYA (JP)
IIYAMA SHOJI (JP)
IIYAMA SHOJI (JP)
Application Number:
PCT/JP2023/020839
Publication Date:
December 21, 2023
Filing Date:
June 05, 2023
Export Citation:
Assignee:
TOKUYAMA CORP (JP)
International Classes:
C01B33/107
Domestic Patent References:
| WO2020137853A1 | 2020-07-02 |
Foreign References:
| JP2009062212A | 2009-03-26 | |||
| JPH06211882A | 1994-08-02 | |||
| JP2004149351A | 2004-05-27 |
Attorney, Agent or Firm:
MAEDA & SUZUKI (JP)
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