Fluid dynamic pressure bearing oil, spindle motor, and disk drive device

Abstract

Object To provide a fluid dynamic pressure bearing oil and a fluid dynamic pressure bearing filled with the fluid dynamic pressure bearing oil, and to provide a spindle motor and a disk drive device including the spindle motor in which the fluid dynamic pressure bearing oil and the bearing are used, thereby suppressing adhesion of a volatile component to a magnetic disk or the like even when the fluid dynamic pressure bearing oil is volatilized, so that occurrence of HDD read/write errors can be suppressed. Solution A fluid dynamic pressure bearing oil contains at least one compound selected from the group consisting of a monoester compound represented by the following Formula (1) and a diester compound represented by the following Formula (2): R1—C(═O)O—R2 (1) (where R1 is an alkyl group having 10 or more carbon atoms in total, R2 is an alkyl group having 9 or more carbon atoms in total, and R3-E1-R4-E2-R5 (2) (where R3 and R5 are each independently an alkyl group having 8 or more carbon atoms in total, R4 is an alkylene group having 4 or more carbon atoms in total, and E1 and E2 are each independently —C(═O)O— or —OC(═O)—.

Dependencies are inferred from the claim text.