Antifoam additives for use in low viscosity applications
A lubricant composition comprising a major amount of a base oil having a kinematic viscosity between 2 and 8 cSt at 100° C. and a minor amount of an additive composition represented by formula IV: wherein x and y can be the same or different and (x+y) equals between 50 and 1,500 and m and n can be the same or different and Q is hydrogen or a monovalent organic group selected from the group consisting of C1-C8 alkyl, acetyl and isocyanato group of the formula —NCO.
1. A lubricant composition comprising:
a) a major amount of a base oil having a kinematic viscosity between 2 and 8 cSt at 100° C.; and
b) a minor amount of an additive composition represented by formula I:
wherein x and y can be the same or different and (x+y) equals between 50 and 1,500 and R is a polyoxyalkylene group having a molecular weight of 500-5000 g/mol and is represented by the following formula:
—(CH 2 ) a —O—(C 2 H 4 O) m (C 3 H 6 O) n -Q
Q is hydrogen or a monovalent organic group selected from the group consisting of C1-C8 alkyl, acetyl and isocyanato group of the formula —NCO, subscript a is a positive integer of 2-6, m is a positive integer of 3-6 and n is a positive integer of 20-40.
2. The lubricant composition of claim 1 wherein x is between 100 and 300 and y is between 10 and 20.
3. The lubricant composition of claim 1 wherein subscript a is a positive integer of 2-3.
4. The lubricant composition of claim 1 wherein the —(C 2 H 4 O) m (C 3 H 6 O) n — group forms a random copolymer or a block copolymer.
5. A lubricant composition comprising:
a) a major amount of a base oil having a kinematic viscosity between 2 and 8 cSt at 100° C.; and
b) a minor amount of an additive composition represented by formula IV:
wherein x and y can be the same or different and (x+y) equals between 50 and 1,500 and m and n can be the same or different and m is a positive integer of 3-6 and n is a positive integer of 20-40 and Q is hydrogen or a monovalent organic group selected from the group consisting of C1-C8 alkyl, acetyl and isocyanato group of the formula —NCO.
6. The lubricant composition of claim 5 wherein x is between 160 and 190 and y is between 14 and 18, and Q is hydrogen or methyl.
7. The lubricant composition of claim 1 , wherein said minor amount of an additive composition delivers between 2 and 50 ppm of silicon to the lubricant composition.
8. The lubricant composition of claim 5 , wherein said minor amount of an additive composition delivers between 2 and 25 ppm of silicon to the lubricant composition.
9. The lubricant composition of claim 1 wherein the base oil has a kinematic viscosity between 2 and 6 cSt at 100° C.
10. The lubricant composition of claim 1 , further comprising an oil-soluble ashless dispersant selected from the group consisting of: a succinimide dispersant, a succinic ester dispersant, a succininic ester-amide dispersant, a Mannich base dispersant, phosphorylated, boronated or phosphorylated and boronated forms thereof.
11. The lubricant composition of claim 1 , further comprising one or more of the following: an air expulsion additive, an antioxidant, a corrosion inhibitor, a foam inhibitor, a metallic detergent, an organic phosphorus compound, a seal-swell agent, a viscosity index improver, and an extreme pressure additive.
12. A method of lubricating a machine part comprising lubricating said machine part with the lubricant composition of claim 1 .
13. The method of claim 12 , wherein said machine part comprises a gear, an axle, a differential, an engine, a crankshaft, a transmission, or a clutch.
14. The method of claim 13 , wherein said transmission is selected from the group consisting of an automatic transmission, a manual transmission, an automated manual transmission, a semi-automatic transmission, a dual clutch transmission, a continuously variable transmission, and a toroidal transmission.
15. The method of claim 13 , wherein said clutch comprises a continuously slipping torque converter clutch, a slipping torque converter clutch, a lock-up torque converter clutch, a starting clutch, one or more shifting clutches, or an electronically controlled converter clutch.
16. The method of claim 13 , wherein said machine part is selected from the group consisting of an automotive gear, a stationary gearbox, and an axle.
17. The method of claim 13 , wherein said gear is selected from the group consisting of a hypoid gear, a spur gear, a helical gear, a bevel gear, a worm gear, a rack and pinion gear, a planetary gear set, and an involute gear.
18. The method of claim 13 , wherein said differential is selected from the group consisting of a straight differential, a turning differential, a limited slip differential, a clutch-type limited slip differential, and a locking differential.
19. The method of claim 13 , wherein said engine is selected from the group consisting of an internal combustion engine, a rotary engine, a gas turbine engine, a four-stroke engine, and a two-stroke engine.
20. The method of claim 13 , wherein said engine comprises a piston, a bearing, a crankshaft, and/or a camshaft.
21. A method for improving the antifoam properties of a lubricating fluid having a kinematic viscosity of between 2-8 cSt at 100° C., comprising including in a lubricating fluid an effective amount of one or more compounds of formula I
wherein x and y can be the same or different and (x+y) equals between 50 and 1,500 and R is a polyoxyalkylene group having a molecular weight of 500-5000 g/mol and is represented by the following formula:
—(CH 2 ) a —O—(C 2 H 4 O) m (C 3 H 6 O) n -Q
Q is hydrogen or a monovalent organic group selected from the group consisting of C1-C8 alkyl, acetyl and isocyanato group of the formula —NCO, subscript a is a positive integer of 2-6, m is a positive integer of 3-6 and n is a positive integer of 20-40.
22. The method of claim 21 wherein the one or more compounds of formula I comprises one or more compounds of formula IV
wherein x and y can be the same or different and (x+y) equals between 50 and 1,500 and m and n can be the same or different and m is a positive integer of 3-6 and n is a positive integer of 20-40 and Q is hydrogen or a monovalent organic group selected from the group consisting of C1-C8 alkyl, acetyl and isocyanato group of the formula —NCO.
23. The method of claim 21 wherein x is between 160 and 190 and y is between 14 and 18, and Q is hydrogen or methyl.
24. A method for improving the antifoam properties of a lubricating fluid while lubricating an automotive component requiring lubrication, comprising:
1) adding a lubricating fluid to an automotive component requiring lubrication, said fluid comprising (a) a base oil having a kinematic viscosity at between 2 and 5 cSt at 100° C., and (b) one or more compounds of formula IV
wherein x and y can be the same or different and (x+y) equals between 50 and 1,500 and m and n can be the same or different and m is a positive integer of 3-6 and n is a positive integer of 20-40 and Q is hydrogen or a monovalent organic group selected from the group consisting of C1-C8 alkyl, acetyl and isocyanato group of the formula —NCO; and
2) operating the automotive component that contains the fluid,
wherein the antifoam performance of the fluid is improved relative to the performance of a lubricating fluid free of the compound of 1) (b).
25. The method of claim 24 wherein x is between 160 and 190 and y is between 14 and 18, and Q is hydrogen or methyl.
26. The method of claim 25 , wherein said one or more compounds of claim 1 (b), is present in an amount capable of delivering between 2 and 50 ppm of silicon to the lubricating fluid.