Polyester dispersants, synthesis and use thereof

1. An oil soluble polyester composition comprising a reaction product of:

(a) a hydrocarbyl-substituted succinic acylating agent;

(b) a di-hydroxyalkyl-substituted tertiary amine compound selected from a N,N-di-hydroxyalkyl-substituted tertiary monoamine, a N,N′-di-hydroxyalkyl-substituted tertiary diamine, and combinations thereof; and

(c) a poly(oxyalkyene) polyol having from 2 to 15 C 2-4 alkylene oxide units per molecule.

2. The oil soluble polyester composition of claim 1 , wherein the hydrocarbyl-substituted succinic acylating agent comprises a polyisobutenyl succinic anhydride in which the polyisobutenyl group has a number average molecular weight (M n ) of from 500 to 5000.

3. The oil soluble polyester composition of claim 2 , wherein the hydrocarbyl-substituted succinic acylating agent further comprises a C 12-20 hydrocarbyl-substituted succinic acylating agent.

4. The oil soluble polyester composition of claim 1 , wherein the N,N-di-hydroxyalkyl-substituted tertiary monoamine has the following structure:

wherein:

(a) R 1 is selected from C 1-20 alkyl, C 5-20 cycloalkyl, C 6-20 aryl, 5- to 20-membered heteroaryl, and 5- to 20-membered heterocyclyl, and wherein the alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl groups are optionally substituted;

(b) R in each of the x (RO) and the y (RO) groups is independently C 2-4 alkylene; and

(c) x and y are independently an integer of 1 to 5.

5. The composition of claim 1 , wherein the N,N-di-hydroxyalkyl-substituted tertiary monoamine has the following structure:

wherein:

(a) R 2 is hydrogen, C 1-4 alkyl, —NH—(C 6-10 aryl), —NH—(C 7-16 aralkyl), —O—(C 1-4 alkyl), —O—(C 6-10 aryl), or —O—(C 7-16 aralkyl)

(b) R in each of the x (RO) and the y (RO) groups is independently C 2-4 alkylene; and

(c) x and y are independently an integer of 1 to 5.

6. The oil soluble polyester composition of claim 5 , wherein the N,N-di-hydroxyalkyl tertiary monoamine is selected from the group consisting of N,N-bis(2-hydroxyethyl)aniline, N,N-bis(2-hydroxypropyl)aniline, N,N-bis(2-hydroxyethyl)-N′-phenyl-1,4-phenylenediamine, 4-phenoxy-N,N-bis(2-hydroxyethyl)aniline, and 4-benzyloxy-N,N-bis(2-hydroxypropyl)aniline, and combinations thereof.

7. The oil soluble polyester composition of claim 6 , wherein the N,N-di-hydroxyalkyl tertiary monoamine is N,N-bis(2-hydroxyethyl)aniline.

8. The oil soluble polyester composition of claim 1 , wherein the N,N-di-hydroxyalkyl-substituted tertiary monoamine has the following structure:

wherein:

(a) R in each of the x (RO) and the y (RO) groups is independently C 2-4 alkylene;

(b) x and y are independently an integer of 1 to 5;

(c) Z is CH 2 , O, S, N—(C 1-4 alkyl), or N—(C 6-10 aryl);

(d) m is an integer of 1 to 3; and

(e) n is an integer of 1 to 6.

9. The oil soluble polyester composition of claim 8 , wherein the N,N-di-hydroxyalkyl-substituted tertiary monoamine is selected from the group consisting of 2-pyrrolidino-N,N-bis(2-hydroxyethyl)ethylamine, 2-pyrrolidino-N,N-bis(2-hydroxypropyl)ethylamine, 2-piperidino-N,N-bis(2-hydroxyethyl)ethylamine, 2-piperidino-N,N-bis(2-hydroxypropyl)ethylamine 3-piperidino-N,N-bis(2-hydroxyethyl)propylamine, 3-piperidino-N,N-bis(2-hydroxypropyl)propylamine, 2-morpholino-N,N-bis(2-hydroxyethyl)ethylamine, 2-morpholino-N,N-bis(2-hydroxypropyl)ethylamine, 3-morpholino-N,N-bis(2-hydroxyethyl)propylamine, and 3-morpholino-N,N-bis(2-hydroxypropyl)propylamine, and combinations thereof.

10. The oil soluble polyester composition of claim 9 , wherein the N,N-di-hydroxyalkyl-substituted tertiary monoamine is 3-morpholino-N,N-bis(2-hydroxyethyl)propylamine.

11. The oil soluble polyester composition of claim 1 , wherein the N,N-di-hydroxyalkyl-substituted tertiary monoamine has the following structure:

wherein:

(a) R in each of the x (RO), y (RO) and z (RO) groups is independently C 2-4 alkylene;

(b) x, y and z are independently an integer of 1 to 5; and

(c) Ar is optionally substituted C 6-20 aryl.

12. The oil soluble polyester composition of claim 11 , wherein the N,N-di-hydroxyalkyl-substituted tertiary monoamine has the following structure:

13. The oil soluble polyester composition of claim 1 , wherein the N,N′-di-hydroxyalkyl-substituted tertiary diamine has the following structure:

wherein:

(a) R in each of the x (RO) and the y (RO) groups is independently C 2-4 alkylene; and

(b) q is an integer of 1, 2, or 3.

14. The oil soluble polyester composition of claim 13 , wherein the N,N′-di-hydroxyalkyl-substituted tertiary diamine is selected from the group consisting of N,N′-bis(2-hydroxyethyl)piperazine, N,N′-bis(2-hydroxypropyl)piperazine, N-(2-hydroxyethyl)-N′-(2-hydroxypropyl)piperazine, N-(2-hydroxyethyl)-N′-(2-hydroxybutyl)piperazine, N,N′-bis(2-hydroxyethyl)homopiperazine, N,N′-bis(2-hydroxypropyl)homopiperazine, and combinations thereof.

15. The oil soluble polyester composition of claim 14 , wherein the N,N′-di-hydroxyalkyl-substituted tertiary diamine is N,N′-bis(2-hydroxyethyl)piperazine.

16. An oil soluble polyester composition as in any one of claims 4 , 5 , 8 11 , and 13 , in which R in each of the x (RO) and the y (RO) groups is independently selected from ethylene and propylene.

17. An oil soluble polyester composition as in any one of claims 4 , 5 , 8 11 , and 13 , in which x is an integer of 1 and y is an integer of 1.

18. The oil soluble polyester composition of claim 1 , wherein the poly(oxyalkylene) polyol has from 5 to 15 C 2-4 alkylene oxide units per molecule.

19. The oil soluble polyester composition of claim 1 , wherein the reaction product further comprises an aliphatic dicarboxylic acid having 6 to 20 carbon atoms, an aromatic dicarboxylic acid having 8 to 20 carbon atoms, or a combination thereof.

20. A lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity and (b) from 0.05 to 15 wt. %, based on the total weight of the lubricating oil composition, of the oil soluble polyester composition of claim 1 .

21. The lubricating oil composition of claim 20 , further comprising at least one additive selected from the group consisting of demulsifiers, detergents, dispersants, extreme pressure agents, foam inhibitors, friction modifiers, multifunctional additives, oxidation inhibitors, pour point depressants, rust inhibitors, and wear inhibitors.

22. A lubricating oil additive concentrate comprising from 80 to 20 wt. % of an organic liquid diluent and from 20 to 80 wt. % of the oil soluble polyester composition of claim 1 .

23. A method for controlling soot-induced viscosity increase experienced in diesel engine lubricating oils during use in diesel engines, the method comprising employing as the diesel engine lubricating oil the lubricating oil composition of claim 20 .

24. A method of improving soot dispersancy in an internal combustion engine which comprises operating the engine with a lubricating oil composition comprising a major amount of oil of lubricating viscosity and an effective amount of the oil soluble polyester composition of claim 1 .

25. A process for preparing an oil soluble polyester composition which comprises reacting a mixture comprising:

(i) a hydrocarbyl-substituted succinic acylating agent;

(ii) a di-hydroxyalkyl-substituted tertiary amine compound selected from a N,N-di-hydroxyalkyl-substituted tertiary monoamine, a N,N′-di-hydroxyalkyl-substituted tertiary diamine, and combinations thereof; and (c) a poly(oxyalkyene) polyol having from 2 to 15 C 2-4 alkylene oxide units per molecule;

wherein a charge mole ratio of the di-hydroxalkyl-substituted tertiary amine compound and poly(oxyalkylene) polyol to the hydrocarbyl succinic acylating agent in the mixture is maintained at 0.67 to 1.5:1.

26. The process of claim 25 , wherein the mixture is maintained at a temperature of 150° C. to 260° C.

27. The process of claim 25 , wherein the hydrocarbyl-substituted succinic acylating agent comprises a polyisobutenyl succinic anhydride in which the polyisobutenyl group has a number average molecular weight (M n ) of from 500 to 5000.

28. The process of claim 25 , wherein the poly(oxyalkylene)polyol is selected from one or more of polyethylene glycol 200, polyethylene glycol 300, polyethylene glycol 400, polyethylene glycol 600, polypropylene glycol 400, and polypropylene glycol 725.

29. The oil soluble polyester composition of claim 1 , wherein the poly(oxyalkylene) polyol is selected from one or more of polyethylene glycol 200, polyethylene glycol 300, polyethylene glycol 400, polyethylene glycol 600, polypropylene glycol 400, and polypropylene glycol 725.

30. The process of claim 25 , wherein the poly(oxyalkylene) polyol has from 5 to 15 C 2-4 alkylene oxide units per molecule.