Dispersant viscosity modifiers containing aromatic amines

• US 20060025316A1
• Filed: 07/29/2005
• Published: 02/02/2006
• Est. Priority Date: 07/30/2004
• Status: Active Grant

• Current Assignee: The Lubrizol Corporation (Berkshire Hathaway Incorporated)
• Original Assignee: The Lubrizol Corporation (Berkshire Hathaway Incorporated)
• Inventors: Pudelski, John K., Gieselman, Matt D., Friend, Christopher, Eveland, Renee A., Schober, Barton J., Covitch, Michael J., Raguz, Mary Galic
• Granted Patent: US 7,790,661 B2
• Time in Patent Office: Days
• US Class Current: 508/459
• CPC Class Codes: C10L 1/221 compounds of uncertain formula; reaction products where mixtures of compounds are obtained
• CPC Class Codes: C10L 1/238 obtained otherwise than by reactions involving only carbon-to-carbon unsaturated bonds C10L1/221 takes precedence
• CPC Class Codes: C10M 133/56 Amides; Imides
• CPC Class Codes: C10M 133/58 Heterocyclic compounds
• CPC Class Codes: C10M 149/06 containing monomers having an unsaturated radical bound to an amido or imido group
• CPC Class Codes: C10M 149/10 containing monomers having an unsaturated radical bound to a nitrogen-containing hetero ring
• CPC Class Codes: C10M 151/02 Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
• CPC Class Codes: C10M 2215/28 Amides; Imides
• CPC Class Codes: C10M 2217/024 containing monomers having an unsaturated radical bound to an amido or imido group
• CPC Class Codes: C10M 2217/028 containing monomers having an unsaturated radical bound to a nitrogen-containing hetero ring
• CPC Class Codes: C10M 2221/00 Organic macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
• CPC Class Codes: C10N 2030/041 Soot induced viscosity control
• CPC Class Codes: C10N 2040/25 Internal-combustion engines
• CPC Class Codes: C10N 2040/252 Diesel engines

Abstract

Reaction of a carboxylic acid-containing polymer with certain aromatic amines results in dispersant viscosity modifiers with improved soot handling performance in heavy-duty diesel engines, compared with reaction with non-aromatic amines.

Claims

1. A method for lubricating a diesel engine equipped with exhaust gas recirculation, comprising supplying thereto a composition comprising an oil of lubricating viscosity and the reaction product of:

(a) a polymer comprising carboxylic acid functionality or a reactive equivalent thereof, said polymer having a number average molecular weight of greater than 5,000; and

(b) an amine component comprising at least one aromatic amine containing at least one amino group capable of condensing with said carboxylic acid functionality to provide a pendant group and at least one additional group comprising at least one nitrogen, oxygen, or sulfur atom, wherein said aromatic amine is selected from the group consisting of (i) a nitro-substituted aniline, (ii) amines comprising two aromatic moieties linked by a —

C(O)NR—

group, a —

C(O)O—

group, an —

O—

group, an —

N═

N—

group, or an —

SO₂—

group, where R is hydrogen or hydrocarbyl, one of said aromatic moieties bearing said condensable amino group, (iii) an aminoquinoline, (iv) an aminobenzimidazole, (v) an N,N-dialkylphenylenediamine, and (vi) a ring-substituted benzylamine.

2. The method of claim 1 wherein said polymer comprises an ethylene-alpha olefin copolymer containing grafted carboxylic functionality.

3. The method of claim 2 wherein said polymer comprises an ethylene-propylene copolymer, optionally containing at least one additional monomer derived from a non-conjugated diene.

4. The method of claim 1 wherein said polymer comprises an isobutylene/conjugated diene polymer containing grafted carboxylic functionality or a partially esterified maleic anhydride-styrene copolymer.

5. The method of claim 1 wherein said polymer comprises a substantially hydrogenated copolymer of styrene and a conjugated diene.

6. The method of claim 1 wherein said polymer comprises a polyacrylate or a polymethacrylate.

7. The method of claim 1 wherein the acid functionality or reactive equivalent thereof is provided by grafted maleic anhydride functionality.

8. The method of claim 1 wherein the aromatic amine contains an —

NH₂ group upon an aromatic ring.

9. The method of claim 1 wherein the aromatic amine comprises a nitroaniline.

10. The method of claim 9 wherein the nitroaniline is 3-nitroaniline.

11. The method of claim 1 wherein the aromatic amine comprises two aromatic moieties linked by an —

O—

group, an —

N═

N—

group, a —

C(O)NR—

group, a —

C(O)O—

group, or an —

SO₂—

group where R is hydrogen or hydrocarbyl, one of said aromatic moieties bearing said condensable amino group.

12. The method of claim 11 wherein the aromatic amine comprises 4-(4-nitrophenylazo)aniline.

13. The method of claim 1 wherein the aromatic amine comprises at least one of an aminoquinoline, an aminobenzimidazole, an N,N-dialkylphenylenediamine, or a ring-substituted benzylamine.

14. The method of claim 1 wherein the amine component comprises, in addition to the aromatic amine, an aliphatic amine having up to about 8 carbon atoms.

15. The method of claim 14 wherein the aliphatic amine comprises N,N-dimethylaminopropylamine or aminopropylmorpholine.

16. The method of claim 14 wherein the aromatic amine comprises 3-nitroaniline and the aliphatic amine comprises N,N-dimethylaminopropylamine.

17. The method of claim 14 wherein the aliphatic amine comprises ethylenediamine and is present in an amount of about 1 to about 15 weight percent of the total amine component present.

18. The method of claim 1 wherein the amine component further comprises a minor amount of a branching or crosslinking amine.

19. The method of claim 1 wherein the number average molecular weight of the polymer is about 5,000 to about 150,000.

20. The method of claim 1 wherein the amount of carboxylic monomers on the polymer is about 1 to about 5 weight percent.

21. The method of claim 1 wherein the amount of the reacted aromatic amine is about 2.8 to about 6.6 weight percent of the polymer.

22. The method of claim 1 wherein the composition comprises a mixture of multiple polymeric reaction products differing in amine type or in molecular weight or both.

23. The method of claim 1 wherein the composition further comprises at least one material selected from the group consisting of additional dispersants, detergents, anti-oxidants, pour point depressants, anti-wear agents, and polymeric viscosity modifiers.

24. The method of claim 23 wherein the polymeric viscosity modifier comprises a hydrogenated styrene/conjugated diene viscosity modifier.

25. A lubricant composition comprising an oil of lubricating viscosity having a kinematic viscosity at 100°

C. of at least 3.5 mm²/second and the reaction product of;

(a) a polymer comprising carboxylic acid functionality or a reactive equivalent thereof, said polymer having a number average molecular weight of greater than 5,000; and

(b) an amine component comprising 3-nitroaniline.

26. The lubricant composition of claim 25 further comprising at least one material selected from the group consisting of additional dispersants, detergents, anti-oxidants, pour point depressants, anti-wear agents, and polymeric viscosity modifiers.

27. A method of lubricating an internal combustion engine, comprising supplying thereto the lubricant composition of claim 25.