Calcium may be a good thing, according to Lubrizol's patent.
https://patents.google.com/patent/EP2625254A1/en
TITLE: Lubricating Oil Composition with Anti-Mist Additive
FIELD OF INVENTION
[0001] The present invention relates to a lubricating composition containing an oil of lubricating viscosity, a high molecular weight polyolefin that is at least substantially free of ethylene- derived blocks, and an overbased metal containing detergent capable of reducing intake valve deposits in a direct injection engine.
Case No. 3852-01 Claims:
1. A lubricant composition comprising
(a) an oil of lubricating viscosity,
(b) a polyolefin of number average molecular weight at least about 20,000, wherein the polymer comprises 0 to about 20 percent by weight of ethylene-derived monomer units, said polyolefin being present in an amount of about 0.001% to about 1.0% by weight of the composition, and
(c) an overbased metal containing detergent.
2. The composition of claim 1 where the polyolefin comprises about 50 to 100% by weight of units derived from at least one olefin monomer having four or more carbon atoms.
3. The composition of claim 1 or claim 2 where the polyolefin has a number average molecular weight of at least about 50,000 and comprises isobutylene-derived units.
4. The composition of any one of claims 1 through 3 where the number average molecular weight of the polymer is about 200,000 to about 10,000,000.
5. The composition of any of claims 1 through 4 where the overbased detergent comprises a
calcium sulfonate with a metal ratio of at least about 3.5.
6. The composition of any of claims 1 through 5 wherein the overbased detergent comprises a phenol-based detergent.
7. The composition of any of claims 1 through 6 wherein the overbased detergent contributes about 90 percent to about 100 percent of the TBN to the composition.
8. The composition of any of claims 1 through 6 wherein the overbased detergent contributes about 40 percent to about 90 percent of the TBN to the composition.
9. The composition of any of claims 1 through 8 where the composition has a sulfated ash content of about 0.3% to about 10% by weight.
10. The composition of any of claims 1 through 8 wherein the composition has a sulfated ash content of about 0.3% to about 1.0% by weight.
1 1. The composition of any of claims 1 through 10 further comprising an ashless dispersant, an antiwear agent, an ashless antioxidant, a friction modifier, a viscosity index improver, or a combination thereof.
12. The composition of any of claims 1 through 1 1 wherein the oil of lubricating viscosity comprises an API Group III or Group IV oil or mixtures thereof.
13. A method of lubricating an internal combustion engine, comprising supplying thereto the lubricant composition of any of claims 1 through 12.
14. The method of claim 13 wherein the internal combustion engine is a direct injection gasoline engine.
15. The method of claim 13 wherein the internal combustion engine is a compression-ignition engine.
16. The method of claim 13 wherein the internal combustion engine is a marine diesel engine comprising a cylinder which is lubricated with said lubricant.
17. A method of reducing inlet valve deposits in a direct injection gasoline engine comprising supplying to the engine the lubricant composition of any of claims 1 through 12.
18. A method of reducing oil misting in a direct injection gasoline engine comprising supplying to the engine the lubricant composition of any of claims 1 through 12.
19. A method of reducing oil misting in a compression-ignition engine comprising supplying to the engine the lubricant of any of claims 1 through 12.
20. A method of reducing oil misting in a marine diesel cylinder comprising supplying to the cylinder the lubricant composition of any of claims 1 through 12.
21. The method of claim 20 wherein the marine diesel cylinder is within a 2- stroke marine diesel engine.