Patent ID: 8916060

Claim:
A lubricating oil, comprising: 70% by mass or more of a polyvinyl ether-based compound containing an alkylene glycol or polyoxyalkylene glycol unit and a vinyl ether unit in a molecule, having a molecular weight in a range of 300 to 3,000 and a carbon/oxygen molar ratio of 4.0 or less, wherein the polyvinyl ether-based compound has a structure of formula (I): wherein R 1 , R 2 , and R 3 each represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, which may be identical to or different from one another; R b represents a divalent hydrocarbon group having 2 to 4 carbon atoms; R a represents a hydrogen atom, an aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, an aromatic group which has 1 to 20 carbon atoms and may have a substituent, an acyl group having 2 to 20 carbon atoms, or an oxygen-containing hydrocarbon group having 2 to 50 carbon atoms; R 4 represents a hydrocarbon group having 1 to 10 carbon atoms; when plural R a s, R b s, and R 4 s are present, they may be identical to or different from one another; m represents an average value of 15 to 21; k represents a number of 1 to 50; p represents a number of 2 to 50; and when plural ks and ps are present, units may be in block or in random; and when plural R b Os are present, they may be identical to or different from one another; and 0.5 to 5% by mass of a dehydrating agent, wherein said dehydrating agent is at least one selected from the group consisting of N,N′-dimethylcarbodiimide, N,N′-diisopropylcarbodiimide, N,N′-diisobutylcarbodiiimide, N,N′-dihexylcarbodilmide, N,N-dioctylcarbodiimide, N,N′-dioctadecylcarbodiimide, N,N′-dicyclohexylcarbodiimide, N,N′-diphenylcarobodiimide, N,N′-naphthylcarbodlimide, and N,N′-isopropylphenylcarbodiimide.