Patent ID: 7960319
Filing Date: 2011-06-14
Classification: C10M,C10N

Abstract:
1. A lubricating oil composition comprising the below-described additive components dissolved or dispersed in a base oil; 1) an overbased sulfurized alkylphenol calcium salt having a TBN of 200 to 300 mgKOH/g, in an amount of 0.06 to 0.25 wt. % in terms of a calcium content; (2) an overbased alkylsalicylic acid calcium salt having a base ratio of 1.8 to 2.5 and one hydrocarbyl group of 14 to 18 carbon atoms, the base ratio being expressed in terms of a calcium content in an overbase portion per a calcium content in a soap portion, in an amount, of 0.05 to 0.7 wt. % in terms of a calcium content; (3) an overbased alkylsalicylic acid calcium salt having a base ratio of 4.2 to 5.8 and one hydrocarbyl group of 20 to 28 carbon atoms, the base ratio being expressed in terms of a calcium content in an overbase portion per a calcium content in a soap portion, in an amount of 0.19 to 1.05 wt. % in terms of a calcium content; (4) a borated ashless dispersant in an amount of 0.005 to 0.06 wt. % in terms of a nitrogen content and 0.001 to 0.02 wt. % in terms of a boron content; and (5) a zinc dihydrocarbyldithiophosphate in an amount of 0.01 to 0.1 wt. % in terms of a phosphorus content.