Lubricating oil composition for refrigerating machine, working fluid, and refrigerating machine

Abstract

The present invention relates to a refrigeration oil for a refrigerating machine using Flon as a refrigerant. In particular, the present invention relates to a lubricating oil composition for a refrigerating machine using hydrofluorocarbon (HFC) containing no chlorine as a refrigerant, also relates to a working fluid and a refrigerating machine.

1 . A lubricating oil composition for a refrigerating machine using a hydrofluorocarbon refrigerant, characterized by comprising as a main component a composition composed of a mixture of the following 1) an ester compound and 2) a mineral oil component, wherein the weight ratio of the mineral oil component/ester compound is 9/1 to 2/8, 
 1) a polyol ester or a complex ester compound comprising a neopentylpolyol, and a monocarboxylic acid and/or a dicarboxylic acid,    2) a mineral oil component having a % Cp of 70% or less as measured by the n-d-M ring analysis, temperature corresponding to 50% distillation of 400° C. or lower as measured by the test method for boiling range distribution of petroleum fractions by gas chromatography and a pour point of −30° C. or lower.    
     
     
         2 . A lubricating oil composition for a refrigerating machine according to  claim 1 , wherein the pour point of the mixture of the ester compound and the mineral oil component is −35° C. or lower.  
     
     
         3 . A lubricating oil composition for a refrigerating machine according to  claim 1  or  2 , wherein the normal paraffin content of the mineral oil component is 2% or less.  
     
     
         4 . A working fluid for a refrigerating machine comprising the lubricating oil composition for a refrigerating machine defined in any one of  claims 1  to  3 , and a hydrofluorocarbon refrigerant consisting of carbon, hydrogen, and fluorine.  
     
     
         5 . A refrigerant compression type refrigerating machine comprising at least a compressor, a condenser, an expanding mechanism, and an evaporator, and using the working fluid for a refrigerating machine defined in claim  4 .