Patent ID: 6528459
Filing Date: 2003-03-04
Classification: C10M,C10N

Abstract:
A lubricant for a slow-speed two-stroke crosshead marine engine, fed with a fuel with a sulphur content of greater than or equal to 1%, comprising: a mixture of distillates used as lubricating bases including x% by weight of succinimide dispersant additive, y% by weight of overbased sulphonate detergent additive and z% by weight of overbased phenate detergent additive, wherein x, y and z are chosen within the ranges 0.5&lE;x&lE;2.5, 3.5&lE;5&lE;10, 11&lE;z&lE;24.5, 15&lE;x+y+z&lE;36 and 1.5&lE;y/x&lE;5, wherein the BN of the lubricant, determined according to ASTM Standard D-2896, is greater than or equal to 70 mg of KOH/g, and wherein the rate of neutralization by the lubricant of sulphuric acid is greater than or equal to 11Ã—102 Pa/s at 100Â° C., the rate of neutralization being defined by the maximum rate of increase in pressure in a closed chamber with walls covered with a film of the said lubricant with a thickness of 80 to 150 &mgr;m, which chamber is maintained at 100Â° C. and in which is vaporized a known amount of sulphuric acid.