LUBRICATING OIL FOR REFRIGERATION MACHINE

摘要

PURPOSE:To obtain a lubricating oil suitable for refrigeration machines using a hydrogen-containing halogenated hydrocarbon-based substitute fluorocarbon refrigerant, especially a non-chlorine-based halogenated hydrocarbon refrigerant. CONSTITUTION:This lubricating oil for refrigeration machine contains a fumaric acid alkyl ester polymer or copolymer obtained by polymerizing a straight-chain lower alkyl diester of fumaric acid or maleic acid in the presence of a polymerization initiator in a tetrahydrofuran solvent. This lubricating oil has wide temperature range compatible with a substitute fluorocarbon refrigerant R134a and high index of viscosity.