Abstract: A dimethylpolysiloxane composition comprising at least two dimethylpolysiloxanes selected from dimethylpolysiloxanes represented by formula (1) or formula (2), wherein m is an integer with 0?m?10 and n is an integer with 3?n?10, one of said at least two dimethylpolysiloxanes is dodecamethylpentasiloxane contained in an amount of 15 to 95 wt % based on a total weight of the composition, and the composition has a moisture content of at most 50 ppm based on the total weight of the composition.

Abstract: A dimethylpolysiloxane composition comprising at least two dimethylpolysiloxanes selected from dimethylpolysiloxanes represented by formula (1) or formula (2), 1

Abstract: A rotational speed variable type refrigerant compressor includes a closed vessel in which a refrigerator oil is received and stored, a rotational speed variable type motor mechanism and a compressing mechanism driven by the motor mechanism to compress a refrigerant. The compressing mechanism includes a slidable part which comprises a first slidable member made of a ferrous material with a nitrided layer composed of an iron nitride as a main component formed on the surface thereof and a second slidable member made of a ferrous material with an iron oxide layer composed of Fe.sub.3 O.sub.4 as a main component formed on the surface thereof along which the first slidable member comes in slidable contact with the second slidable member. For example, a shaft is constituted by the first slidable member. In addition, for example, each of the bearings for rotatably supporting the shaft is consituted by the second slidable member.