System lubricating oil composition for crosshead diesel engine
The disclosure provides (i) a lubricating oil composition including a base oil (A) with a kinematic viscosity at 100° C. of 8.2-12.6 mm 2 /s and a saturated hydrocarbon content of 90% by mass or more, a metallic detergent (B) and a zinc dithiophosphate (C), wherein a content of the metallic detergent (B) is 2.5 mmol or more as a soap content concentration per 100 g of the composition, a phosphorous content is 200-1000 mass ppm, and a base number is 7.5 mg KOH/g or more, and (ii) a lubricating oil composition including the base oil (A), the metallic detergent (B), the zinc dithiophosphate (C) and an amine-based antioxidant (E), wherein a content of the amine-based antioxidant (E) is 0.3% by mass or more in terms of total content of the composition, a base number is 6.5 mg KOH/g or more, and a phosphorous content is 200-1000 mass ppm.
1. A system lubricating oil composition for a crosshead diesel engine, comprising:
a base oil (A) with a kinematic viscosity at 100° C. of 8.2 mm 2 /s to 12.6 mm 2 /s and a saturated hydrocarbon content of 90% by mass or more;
a metallic detergent (B), wherein the metal is Ca; and
a zinc dialkyldithiophosphate (C),
wherein the base oil (A) includes a group II base oil and/or a group III base oil,
the metallic detergent (B) comprises Ca salicylate,
a content of the metallic detergent (B) is 2.5 mmol or more as a soap content concentration per 100 g of the composition,
a content by percentage of the metallic detergent (B) is, in terms of total content of the composition, 8.0% by mass or less,
a phosphorous content is 350 mass ppm to 1000 mass ppm, and
a base number is 7.5 mg KOH/g or more and 15 mg KOH/g or less.
2. The system lubricating oil composition for a crosshead diesel engine according to claim 1 , wherein the base number is 8.0 mg KOH/g or more and 15 mg KOH/g or less.
3. The system lubricating oil composition for a crosshead diesel engine according to claim 1 , further comprising
an ashless dispersant (D) of 0.04% to 0.2% by mass as a nitrogen content in terms of total content of the composition.
4. A system lubricating oil composition for a crosshead diesel engine, comprising:
a base oil (A) with a kinematic viscosity at 100° C. of 8.2 mm 2 /s to 12.6 mm 2 /s and a saturated hydrocarbon content of 90% by mass or more;
a metallic detergent (B), wherein the metal is Ca;
a zinc dialkyldithiophosphate (C); and
an amine-based antioxidant (E),
wherein the base oil (A) includes a group II base oil and/or a group III base oil,
the metallic detergent (B) comprises Ca salicylate,
a content by percentage of the metallic detergent (B) is, in terms of total content of the composition, 8.0% by mass or less,
a content of the amine-based antioxidant (E) is 0.3% by mass or more in terms of total content of the composition,
a base number is 6.5 mg KOH/g or more and 15 mg KOH/g or less, and
a phosphorous content is 350 mass ppm to 1000 mass ppm.
5. The system lubricating oil composition for a crosshead diesel engine according to claim 4 , further comprising an oil-soluble molybdenum compound (F) of 0.005% to 0.06% by mass as a molybdenum content in terms of total content of the composition.
6. The system lubricating oil composition for a crosshead diesel engine according to claim 2 , further comprising
an ashless dispersant (D) of 0.04% to 0.2% by mass as a nitrogen content in terms of total content of the composition.
7. The system lubricating oil composition for a crosshead diesel engine according to claim 4 , wherein the base number is 7.0 mg KOH/g or more and 15 mg KOH/g or less.