LUBRICATING OIL COMPOSITION

摘要

Disclosed are a lubricating oil base oil with excellent endurance and low torque properties, and also a lubricating oil composition suitable for fluid dynamic bearings, porous oil-retaining bearings and dynamic porous oil-retaining bearings used in information apparatus-related miniature spindle motor bearings. The main component of the lubricating oil base oil and lubricating oil composition using the lubricating base oil is a diester as shown in Figure 1. In the formula, R1 and R2 represent an independent 1-ethyl pentyl group, n-heptyl group or n-hexyl group, and; where (A) R1 and R2 are both an n-heptyl group or an n-hexyl group; (B) either R1 or R2 are a 1-ethyl pentyl group; (C) both R1 and R2 are a 1-ethyl pentyl group; the molar ratio thereof is within the range A:B:C 25-65:30-50:3-25.