PURPOSE: To obtain a synthetic lubricant which is composed of an ester derived from a specific monohydric alcohol, monocarboxylic acid, hydroxycarboxylic acid and polybasic carboxylic acid and is compatible with a chlorine-free fluorocarbon refrigerant over a wide range of temperature and shows excellent insulation properties.
CONSTITUTION: This composition comprises the ester derived from (A) a monohydric alcohol of 4-18 carbon atoms in which branched alcohols amount to 50 mole % and more or a neopentyl polyol of 30 or less carbon atoms, (B) a hydroxycarboxylic acid of formula I or II (R1 and R2 are each H, OH, -CH2OH, an alkyl; R3 and R4 are each H, OH, an alkyl) or its condensate, (C) a monocarboxylic acid of 4-18 carbon atoms in which branched carboxylic acids amount to 50% or more, (D) a polycarboxylic acid of 4-10 carbon atom. It is preferred that the working fluid composition for refrigerators is produced from this synthetic lubricant and a chlorine-free fluorocarbon such as HFC-134 at a weight ratio of 1/99-99/1.
NISHIMURA SACHIKO
MEMITA MICHIMASA
SEI NOBUHIKO
