US 12,145,857 B2
Method for producing tungsten hexafluoride
Akiou Kikuchi, Ube (JP); Yuta Takeda, Ube (JP); Masakiyo Nagatomo, Higashiomi (JP); and Akifumi Yao, Ube (JP)
Assigned to CENTRAL GLASS COMPANY, LIMITED, Ube (JP)
Appl. No. 17/268,848
Filed by Central Glass Company, Limited, Ube (JP)
PCT Filed Jul. 12, 2019, PCT No. PCT/JP2019/027628
§ 371(c)(1), (2) Date Feb. 16, 2021,
PCT Pub. No. WO2020/036026, PCT Pub. Date Feb. 20, 2020.
Claims priority of application No. 2018-153509 (JP), filed on Aug. 17, 2018.
Prior Publication US 2021/0253442 A1, Aug. 19, 2021
Int. Cl. C01G 41/04 (2006.01)
CPC C01G 41/04 (2013.01) 20 Claims
OG exemplary drawing
 
1. A production method of tungsten hexafluoride, comprising:
a first step of bringing a first amount of tungsten having an oxide film into contact with a hydrogen fluoride-containing fluorine gas in a reactor, thereby removing the oxide film from the first amount of tungsten and forming a first amount of tungsten hexafluoride and a second amount of tungsten from which the oxide film has been removed, wherein the hydrogen fluoride-containing fluorine gas is a fluorine gas containing from 50 vol ppm to 50 vol % of hydrogen fluoride; and
a second step of bringing the second amount of tungsten from which the oxide film has been removed by the first step into contact with a fluorine-containing gas to form a second amount of tungsten hexafluoride.
 
9. A production method of tungsten hexafluoride, comprising:
a first step of bringing tungsten having an oxide film into contact with a hydrogen fluoride-containing inert gas in a reactor, thereby removing the oxide film from the tungsten, wherein the hydrogen fluoride-containing inert gas is an inert gas containing from 50 vol ppm to 50 vol % of hydrogen fluoride; and
a second step of bringing the tungsten from which the oxide film has been removed by the first step into contact with a fluorine-containing gas to form tungsten hexafluoride.