Refrigerating machine oil, and composition for refrigerating machine

A method of producing a refrigerator oil, the method comprising blending at least:

• (A) a polyvinyl ether-based compound (A) comprising a structural unit (a1) having a methoxy group in a side chain thereof in an amount of 50 mol % or more on a basis of 100 mol % of a whole amount of structural units excluding a terminal structural unit in a molecular structure thereof;
• and
• (B) a polyvinyl ether-based compound (B) comprising a structural unit (b2) represented by formula (2) in an amount of more than 50 mol % on a basis of 100 mol % of a whole amount of structural units excluding a terminal structural unit in a molecular structure thereof, to obtain a refrigerator oil:
• wherein:
• R5, R6, and R7 each independently represent a hydrogen atom or a hydrocarbon group having 1 or more and 8 or less carbon atoms;
• R8 represents a divalent hydrocarbon group having 2 or more and 10 or less carbon atoms;
• n represents a number of 0 or more and 10 or less;
• and
• R9 represents a hydrocarbon group having 2 or more and 10 or less carbon atoms wherein a content ratio [(A)/(B)] of the polyvinyl ether-based compound (A) and the polyvinyl ether-based compound (B) is 10/90 or more and 90/10 or less in terms of a mass ratio.