Functional fluids for internal combustion engines

1. A functional fluid suitable for use in an internal combustion engine, comprising:

(a) a major amount of a base fluid;

(b) a minor amount of a polysubstituted alkanol amine derivative reaction product produced by a process reacting:

(i) a carboxylate compound of formula I

R 1 COOR 2   (I)

in which:

R 1 is an aliphatic C 1-30 -hydrocarbon radical; and

R 2 is hydrogen or alkyl, mono- or polyhydroxyalkyl, or ammonium; with

(ii) an alkanol amine of the formula II

NHR 3 R 4   (II)

wherein R 3 and R 4 are independently selected from hydrogen atoms and linear or branched-chain hydrocarbon groups, the carbon chain of which is optionally interrupted by one or more —NH— groups and which optionally has at least one hydroxyl group attached to a carbon atom of the hydrocarbon group, with the proviso that R 3 and R 4 are not both hydrogen atoms and that at least one of said residues R 3 and R 4 carries at least one hydroxyl group;

wherein said process comprises a molar ratio of the —COO— groups of the carboxylate compound of formula I to the molar sum of —OH and —NH— groups of the alkanol amine of formula II in a range and under at least one reaction condition effective to form the reaction product comprising polysubstituted alkanol amine derivatives; and

(c) a minor amount of a detergent additive.

2. The functional fluid of claim 1 wherein the reaction product (b) comprises said polysubstituted alkanol amine derivatives in an amount of more than 20 wt. % based on the total weight of reaction product (b).

3. The functional fluid of claim 1 wherein R 3 and R 4 independently of each other represent hydrogen or a residue of the formula III

—[(CH 2 ) x NH] y (CH 2 ) z R 5   (III)

wherein

x and z are independently from each other integers from 1 to 6,

y is 0 or an integer of 1 to 3 and

R 5 is hydroxyl or a residue of the formula IV

—NH(CH 2 ) z OH  (IV)

wherein z is, independently, as defined above,

with the proviso that R 3 and R 4 are not both hydrogen atoms.

4. The functional fluid of claim 1 wherein R 1 of the carboxylate compound of formula I is an aliphatic C 8-30 -hydrocarbon radical.

5. The functional fluid of claim 1 wherein the compound of formula II is selected from polyaminoalkanols, wherein one of the residues R 3 and R 4 is hydrogen and the other is a residue of the formula III, wherein x is 2 or 3, y is 0 or 1, z is 2 or 3 and R 5 is hydroxyl or a residue of the formula IV.

6. The functional fluid of claim 1 wherein the detergent additive (c) contains at least one nitrogen-containing detergent containing a hydrophobic hydrocarbon radical having a number average molecular weight in the range of from 300 to 5000.

7. The functional fluid of claim 6 wherein the nitrogen-containing detergent is selected from a group comprising polyalkene monoamines, polyalkene Mannich amines and polyalkene succinimides.

8. The functional fluid of claim 7 wherein the nitrogen-containing detergent is a polyalkene monoamine.

9. The functional fluid of claim 1 wherein the base fluid is a gasoline.

10. The functional fluid of claim 1 wherein the base fluid is a diesel fuel.

11. The functional fluid of claim 9 wherein the reaction product (b) is present in an amount in the range of from 1 parts per million by weight (ppmw) to 5,000 ppmw.

12. The functional fluid of claim 9 wherein the detergent additive (c) is present in an amount in the range of from 1 parts per million by weight (ppmw) to 5,000 ppmw.

13. The functional fluid of claim 1 wherein the base fluid is a lubricating oil.

14. A process for the preparation of a functional fluid of claim 1 comprising bringing into admixture the base fluid, the reaction product (b) and the detergent additive (c).

15. The functional fluid of claim 2 wherein the reaction product (b) comprises said polysubstituted alkanol amine derivatives in an amount of more than 40 wt. %, based on the total weight of the reaction product (b).

16. The functional fluid of claim 2 wherein the reaction product (b) comprises said polysubstituted alkanol amine derivatives in an amount of more than 60 wt. %, based on the total weight of the reaction product (b).

17. The functional fluid of claim 1 wherein said range of molar ratio of the —COO— groups of the carboxylate compound of formula I to the molar sum of —OH and —NH— groups of the alkanol amine of formula II is equal to or less than 1.

18. The functional fluid of claim 17 , wherein said range of molar ratio of the —COO— groups of the carboxylate compound of formula I to the molar sum of —OH and —NH— groups of the alkanol amine of formula II is about 1.8:3 to 3:3.

19. The functional fluid of claim 18 wherein said range of molar ratio of the —COO— groups of the carboxylate compound of formula I to the molar sum of —OH and —NH— groups of the alkanol amine of formula II is about 1.9:3 to 2.5:3.