Composition including fluoromethane and method for producing same

Abstract

An object of the present invention is to provide a composition containing fluoromethane having high purity. A method for producing fluoromethane, comprising: pyrolyzing in a gas phase a fluorine-containing methyl ether represented by Formula (1): wherein R 1 and R 2 are the same or different, and each represents an optionally substituted linear or branched monovalent aliphatic hydrocarbon group, an optionally substituted monovalent aromatic hydrocarbon group, an optionally substituted monovalent cyclic aliphatic hydrocarbon group, hydrogen, or halogen, in the presence of an alumina catalyst to thereby obtain a mixed gas containing fluoromethane and acid fluoride, wherein: the alumina catalyst contains chlorine in an amount of 1.0 wt % or less.

1 - 2 . (canceled) 
     
     
         3 . A composition comprising fluoromethane obtainable by a method comprising:
 pyrolyzing in a gas phase a fluorine-containing methyl ether represented by Formula (1):   
       
         
           
           
               
               
           
         
       
       wherein R 1  and R 2  are the same or different, and each represents an optionally substituted linear or branched monovalent aliphatic hydrocarbon group, an optionally substituted monovalent aromatic hydrocarbon group, an optionally substituted monovalent cyclic aliphatic hydrocarbon group, hydrogen, or halogen,
 in the presence of an alumina catalyst to thereby obtain a mixed gas containing fluoromethane and acid fluoride, 
 wherein: 
 the alumina catalyst contains chlorine in an amount of 1.0 wt % or less. 
 
     
     
         4 . A composition comprising fluoromethane in an amount of 99.999 mol % or more based on the total weight of the composition. 
     
     
         5 . The composition according to  claim 3 , wherein the composition is used as a dry etching gas. 
     
     
         6 - 7 . (canceled) 
     
     
         8 . A composition comprising fluoromethane obtainable by a method comprising:
 pyrolyzing in a gas phase a fluorine-containing methyl ether represented by Formula (1):   
       
         
           
           
               
               
           
         
       
       wherein R 1  and R 2  are the same or different, and each represents an optionally substituted linear or branched monovalent aliphatic hydrocarbon group, an optionally substituted monovalent aromatic hydrocarbon group, an optionally substituted monovalent cyclic aliphatic hydrocarbon group, hydrogen, or halogen,
 in the presence of a γ-alumina catalyst to thereby obtain a mixed gas containing fluoromethane and acid fluoride,
 wherein: 
 
 the γ-alumina catalyst contains chlorine in an amount of 1.0 wt % or less. 
 
     
     
         9 . The composition according to  claim 8 , wherein the composition is used as a dry etching gas. 
     
     
         10 . The composition according to  claim 4 , wherein the composition is used as a dry etching gas.