Lubricant oil composition comprising a fluorine-containing aromatic compound and an alkyl- or alkyl derivative-substituted aromatic compound, and a refrigerant composition containing the same

A lubricant oil composition comprising:

• (A) a fluorine-containing aromatic compound, and
• (B) an alkyl- or alkyl derivative-substituted aromatic compound,
• wherein said fluorine-containing aromatic compound (A) is present in an amount of from 0.1 to 99.9% by weight, based on the total weight of said fluorine-containing aromatic compound (A) and said alkyl- or alkyl derivative-substituted aromatic compound (B),
• said fluorine-containing aromatic compound being represented by the formula:
• R(XR.sub.f).sub.n (A)
• wherein:
• X represents an oxygen or a sulfur atom;
• n is an integer of from 1 to 4;
• R represents an n-valent aromatic group, having from 6 to 60 carbon atoms, wherein n is as defined above, comprising at least one unsubstituted or substituted aromatic nucleus selected from the group consisting of an unsubstituted or substituted benzene nucleus and an unsubstituted or substituted naphthalene nucleus, wherein the ratio of carbon atoms in the aromatic nucleus of said R to carbon atoms in said R is from 0.10 to 1.0, with the proviso that when said n-valent aromatic group comprises at least two unsubstituted or substituted aromatic nuclei, said at least two aromatic nuclei are linked through a single bond or a linkage group containing no aromatic nuclei and having from 0 to 50 carbon atoms and a valence of from 2 to 6 to form a multinuclear structure;
• and
• R.sub.f represents an unsubstituted or partially substituted fluorocarbon group having from 1 to 25 carbon atoms in which the ratio of fluorine atom or atoms to carbon atom or atoms is from 0.6 to 3, wherein said unsubstituted fluorocarbon group is selected from the group consisting of a fluoroalkyl group, a fluoroalkenyl group, a fluoroalkyl group, a fluoroalkylaryl and a fluoroaralkyl group, in which each of the alkyl, alkenyl, aryl, alkylaryl and aralkyl groups is partially or entirely substituted with at least one fluorine atom, and said partially substituted fluorocarbon group has at least one substituent other than fluorine and hydrogen atoms in an amount such that the ratio of said at least one substituent to the total number of fluorine and hydrogen atoms of said partially substituted fluorocarbon group is not greater than 1.5, and wherein a main chain of said unsubstituted or partially substituted fluorocarbon group optionally has from 1 to 7 ether linkages;
• wherein when n is an integer of from 2 to 4, the XR.sub.f groups are the same or different;
• and
• said alkyl- or alkyl derivative-substituted aromatic compound (B) comprising at least one substituted aromatic nucleus selected from the group consisting of a substituted benzene nucleus and a substituted naphthalene nucleus, wherein a substituent of said at least one substituted aromatic nucleus is an unsubstituted or substituted alkyl group having from 1 to 30 carbon atoms, or a derivative thereof, said alkyl- or alkyl derivative-substituted aromatic compound (B) having a kinetic viscosity of from 0.1 to 500 cSt as measured at 40.degree. C.,
• said lubricant oil composition having a kinetic viscosity of from 2 to 500 cSt as measured at 40.degree. C.