Lubricant additive and lubricant composition comprising same
An additive for lubricating oil may include a phosphite ester compound (A) having a specific structure and a phosphite ester compound (B) having a specific structure, wherein the (A):(B) mass ratio of the phosphite ester compound (A) to the phosphite ester compound (B) is in a range of from 99:1 to 80:20. Such an additive may be provided to a lubricating oil, capable of imparting wear resistance and demulsibility with respect to a base oil for lubricating oil, and to impart durability even in the presence of water.
1. A lubricating oil composition, comprising:
a base oil; and
an additive suitable for a lubricating oil, the additive comprising:
a phosphite ester compound (A) of formula (1)
R 1 and R 2 each independently being a branched saturated hydrocarbon group having 8 to 18 carbon atoms; and
a phosphite ester compound (B) of formula (2)
R 3 being a branched saturated hydrocarbon group having 8 to 18 carbon atoms, and M being an organic ammonium in which a saturated or unsaturated hydrocarbon group having 18 carbon atoms is bonded to a nitrogen atom,
wherein an (A):(B) mass ratio of the phosphite ester compound (A) to the phosphite ester compound (B) is in a range of from 99:1 to 88:12,
wherein the additive is present in a range of from 0.5 to 10% by mass, based on total lubricating oil composition mass, and
wherein the base oil is present in a range of from 90 to 99.5% by mass, based on total lubricating oil composition mass.
2. The lubricating oil composition of claim 1 , wherein, in the phosphite ester compound (B), R 3 is isooctyl, 2-ethylhexyl, isononyl, 3,5,5- trimethylhexyl, isodecyl, isostearyl, 2-octyldecyl, or 2-hexyldecyl.
3. The lubricating oil composition of claim 1 , wherein the (A):(B) mass ratio is in a range of from 98:2 to 88:12.
4. The lubricating oil composition of claim 1 , wherein, in the phosphite ester compound (A), R 1 and R 2 are independently isooctyl, 2-ethylhexyl, isononyl, 3,5,5-trimethylhexyl, isodecyl, isostearyl, 2-octyldecyl, 2-octyldodecyl, 2-hexyldecyl group, palmitoyl, oleyl, or linoleyl, and
wherein, in the phosphite ester compound (B), R 3 is 2-ethylhexyl, isodecyl, or oleyl.
5. The lubricating oil composition of claim 1 , wherein, in the phosphite ester compound (B), M is oleyl ammonium.
6. The lubricating oil composition of claim 1 , wherein the (A):(B) mass ratio is in a range of from 99:1 to 90:10.
7. The lubricating oil composition of claim 1 , further comprising:
a sulfur-based extreme pressure agent.
8. The lubricating oil composition of claim 7 , wherein the sulfur-based extreme pressure agent comprises a sulfurized fat, sulfurized oil, and/or polysulfide.
9. The lubricating oil composition of claim 7 , wherein the sulfur-based extreme pressure agent is present in a range of from 1 to 1,000 parts by mass, with respect to 100 parts by mass of a total mass of the phosphite ester compound A and the phosphite ester compound B.
10. The lubricating oil composition of claim 7 , wherein the sulfur-based extreme pressure agent is present in a range of from 10 to 500 parts by mass, with respect to 100 parts by mass of a total mass of the phosphite ester compound A and the phosphite ester compound B.
11. The lubricating oil composition of claim 1 , consisting of the base oil, the additive, and the sulfur-based extreme pressure agent, and
optionally, at least one selected from the group consisting of a dispersant, a viscosity index improver, a rust inhibitor, a corrosion inhibitor, a pour point depressant, a metal deactivator, and a mixture thereof.
12. The lubricating oil composition of claim 1 , wherein the hydrocarbon groups of R 1, R 2, and R 3 independently have 8 to 10 carbon atoms.
13. The lubricating oil composition of claim 1 , wherein the hydrocarbon groups of R 1, R 2, and R 3 are independently 2-ethylhexyl or isodecyl.