Abstract: In a hermetic compressor, aggression to an organic material is low by using a refrigeration oil using, as a base oil, an alicyclic multivalent carboxylic acid ester compound and made of an alicyclic multivalent carboxylic acid ester compound having at least two ester groups, the at least two ester groups being bound to carbon atoms adjacent to each other on an alicyclic ring. The ratio of hydrocarbon radicals in which carbon number is 4 or less among hydrocarbon radicals bound to the at least two ester groups is 15% by weight or less.

Abstract: A highly reliable sliding face modification material capable of forming a stable film of molybdenum disulfide on the sliding face of a sliding member, the sliding face modification material having a molybdenum disulfide content of 95 wt % or more and an organic material content of 1500 ppm or less in weight ratio, and the sliding face modification material being projected onto the sliding face to form a coating layer.

Abstract: A refrigerant compressor having a compression element comprising sliding components made of metallic materials, wherein a mixed layer is formed by solid-dissolving molybdenum disulfide in at least one of the sliding faces of the sliding components, and a single molybdenum disulfide layer is further formed on the surface of the mixed layer. With this configuration, initial break-in is done using the single layer, and sliding loss is reduced. Even if the single layer peels off, because the molybdenum disulfide of the mixed layer is cleaved at a low friction coefficient, solid lubrication action is attained, the friction coefficient of the sliding section is lowered, and sliding loss is reduced.