REFRIGERATOR OIL COMPOSITION AND COMPRESSOR

摘要

PURPOSE: To obtain the subject composition, capable of maintaining characteristics of a base oil and suppressing the production of sludges, improved in friction preventing properties and useful for compressors using hydrofluorocarbon refrigerants by blending the polyol ester base oil with a phosphoric ester and a specific hydrolytic stability improver. CONSTITUTION: This composition is obtained by blending (A) a polyol ester as a base oil (e.g. the one having 5-150mm<2> /sec viscosity at 40 deg.C <=1mg KOH/g acid value and <=500ppm moisture content) with (B) 7.0-15.0 mass% phosphoric ester as an extreme pressure additive and a friction preventing agent [e.g. tricresyl phosphate, (di)phenyl isopropylphenyl phosphate or tris(isopropylphenyl) phosphate] and (C) 0.2-3.0mass% 1,2-epoxyalkane (e.g. 1,2-epoxytetradecane) and/or vinylcyclohexene dioxide as a hydrolytic stability improver.