| 摘要 |
PURPOSE:To obtain the subject composition satisfactory in properties including hygroscopicity, electrical insulation properties, hydrolysis resistance and compatibility with fluorocarbons by mixing a refrigerator oil containing a specified fluorine compound as the base oil with a hydrofluorocarbon. CONSTITUTION:This composition comprises a refrigerator oil having a compound represented by the formula (wherein R<1> and R<4>, which may be the same or different from each other, are each a 1-12C linear or branched alkyl; R<2> and R<3>, which may be the same of different from each other, are each a 2-4C alkylene; and (n) and (m) are each an integer of 0-20) as the base oil and a hydrofluorocarbon. Examples of the hydrofluorocarbons which can be desirably used include especially 1,1,1,2-tetra-fluoroethane and difluoromethane. The compound of the formula may contain a mineral oil or a synthetic oil in an amount within the range not detrimental to its compatibility with the hydrofluorocarbon. The mixing ratio of the compound of the formula or a mixture thereof with additives to the hydrofluorocarbon is desirably 1/2-5/1 (by weight). |
