Method for manufacturing methyl fluoride

Patent metadata

Field	Value
Publication number	US-2016168060-A1
Application number	US-201414909156-A
Country	US
Kind code	A1
Filing date	Aug 7, 2014
Priority date	Aug 9, 2013
Publication date	Jun 16, 2016
Grant date	—

Abstract

An object of the present invention is to provide a method for producing methane fluoride that is useful, for example, as a dry etching gas, the method being more suitable for industrial production. To achieve this object, the present invention provides a method including reacting (A) dimethyl sulfate and (B) at least one fluorocompound in a liquid phase, the fluorocompound (B) being at least one compound selected from the group consisting of hydrogen fluoride and hydrofluoric acid salts, or a metal fluoride, wherein when the fluoride compound (B) includes hydrogen fluoride or a hydrofluoric acid salt, the reaction is carried out without a solvent or using a polar solvent as a solvent, and when the fluoride compound (B) is a metal fluoride, the reaction is carried out using water as a solvent.

First claim

1 . A method for producing methane fluoride (CH 3 F) comprising reacting
(A) dimethyl sulfate and (B) at least one fluorocompound in a liquid phase, the fluorocompound being at least one member selected from the group consisting of hydrogen fluoride and hydrofluoric acid salts, or a metal fluoride, wherein when the fluorocompound (B) includes hydrogen fluoride or a hydrofluoric acid salt, the reaction is carried out without a solvent or using a polar solvent as a solvent, and when the fluorocompound (B) is a metal fluoride, the reaction is carried out using water as a solvent.

2 . The method according to claim 1 , wherein the metal fluoride is at least one metal fluoride represented by formula (1):
MF  (1)
wherein M represents an alkali metal or an alkaline earth metal.

3 . The method according to claim 1 , wherein the hydrofluoric acid salt is at least one hydrofluoric acid salt represented by formula (2) or (3):

wherein R 2 , R 3 , and R 4 are the same or different and each represents hydrogen or an alkyl or cycloalkyl group that may be substituted with at least one halogen atom, and n is an integer of 1 to 5, or

wherein R 5 , R 6 , and R 7 may be the same or different, and each represents hydrogen or an alkyl or cycloalkyl group that may be substituted with at least one halogen atom, and n is an integer of 1 to 5.

4 . The method according to claim 3 , wherein the hydrofluoric acid salt represented by formula (2) is ammonium fluoride (NH 4 F), ammonium hydrogen difluoride (NH 4 FHF), methylamine fluoride (CH 3 NH 3 F), ethylamine fluoride (C 2 H 5 NH 3 F), butylamine fluoride (C 4 H 9 NH 3 F), dimethylamine fluoride ((CH 3 ) 2 NH 2 F), diethylamine fluoride ((C 2 H 5 ) 2 NH 2 F), triethylamine fluoride ((C 2 H 5 ) 3 NHF), or triethylamine trihydrofluoride ((C 2 H 5 ) 3 N.3HF), and/or the hydrofluoric acid salt represented by formula (3) is a pyridine hydrofluoric acid salt.

5 . The method according to claim 1 , wherein the reaction is carried out without a solvent using hydrogen fluoride as the fluorocompound (B).

6 . The method according to claim 5 , wherein the reaction is carried out using hydrogen fluoride in a state liquefied by pressure.

7 . The method according to claim 1 , wherein the reaction is carried out using a metal fluoride and/or a hydrofluoric acid salt as the fluorocompound (B) and using water as a solvent.

8 . The method according to claim 7 , wherein the reaction is carried out by adding dimethyl sulfate (A) dropwise to an aqueous solution of the fluorocompound (B) in water.

Assignees

• Daikin Ind Ltd

Inventors

• Nakamura Shingo
• Fukumoto Kanako
• Etou Yuusuke
• Ohtsuka Tatsuya
• Higashi Masahiro

Classifications

• C07C17/093

  by replacement by halogens · CPC title

• C07C17/07

  by addition of hydrogen halides · CPC title

• C07C17/361 Primary

  by reactions involving a decrease in the number of carbon atoms · CPC title