COMPOSITION FOR REFRIGERATOR WORKING FLUID

摘要

PURPOSE:To obtain the working fluid composition having an excellent compatibility with hydrofluorocarbon and a high resistance to acid value increase caused by hydrolysis by mixing a refrigerator oil containing a specified compound as a base oil with a hydrofluorocarbon. CONSTITUTION:The working fluid composition comprises a refrigerator oil containing a compound containing at least one acetal group and a residue of a tri- to octa-hydric alcohol in the molecule as a base oil and a hydrofluorocarbon. Examples of the compound as the base oil include ones containing alcohol residues such as residues derived by acetalizing two hydroxyl groups of glycerol with a ketone such as acetone to form a cyclic acetal, and desirable compounds are ones of formulas I and/or II (wherein X is a residue of a polyol such as glycerol, Y is a residue of a polyol such as pentaerythritol; R<1> is a monovalent group selected from the group consisting of groups of formula III (wherein R<5> is a 20C or lower alkyl or the like) or the like; R<2> and R<3> are each a 20C or lower alkyl or the like; and R<4> is hydrogen or a monovalent group of formula III.