| abstract |
There is disclosed a lubricating oil composition for cellulose base wet friction material which comprises a base oil blended with (A) a boron-containing imide base dispersant (e.g. boron treated polyalkenyl succinimide) having a weight-average molecular weight in the range of 500 to 3000 and having a ratio by weight of boron to nitrogen (B/N) in the range of 0.1 to 1.5 in such a blending amount that the boron content and the nitrogen content each derived from the component (A) are made to be at least 60 ppm by weight and at least 100 ppm by weight, respectively based on the base oil. The above lubricating oil composition enhances peeling resistant durability for a friction material, especially a cellulose base friction material without impairing the wear resistance or scoring resistance of a steel material element, and is well suited for use in a cellulose base friction material for a starting and running device and a transmission clutch that are used in an automatic transmission of an automobile. |