Effective antioxidant combination for oxidation and deposit control in crankcase lubricants

• US 6,599,865 B1
• Filed: 07/12/2002
• Issued: 07/29/2003
• Est. Priority Date: 07/12/2002
• Status: Expired due to Term

• Current Assignee: Afton Chemical Corporation
• Original Assignee: Ethyl Corporation (Newmarket Corporation)
• Inventors: Lam, William Y., Esche, Carl K. Jr., Gatto, Vincent J.
• Primary Examiner(s): Howard, Jacqueline V.
• Application Number:
  US10/194,517
• Time in Patent Office: 382 Days
• Field of Search: 508/254, 508/322, 508/331
• US Class Current: 508/254
• CPC Class Codes: C10M 141/06 at least one of them being an organic nitrogen-containing compound
• CPC Class Codes: C10M 2203/1025 used as base material
• CPC Class Codes: C10M 2203/1065 used as base material
• CPC Class Codes: C10M 2203/1085 used as base material
• CPC Class Codes: C10M 2209/108 etherified
• CPC Class Codes: C10M 2215/064 Di- and triaryl amines
• CPC Class Codes: C10M 2219/022 of hydrocarbons, e.g. olefines polyolefins C10M2221/041
• CPC Class Codes: C10M 2219/024 of esters, e.g. fats
• CPC Class Codes: C10M 2219/066 Thiocarbamic type compounds
• CPC Class Codes: C10N 2030/04 Detergent property or dispersant property
• CPC Class Codes: C10N 2030/06 Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• CPC Class Codes: C10N 2030/10 Inhibition of oxidation, e.g. anti-oxidants
• CPC Class Codes: C10N 2030/42 Phosphor free or low phosphor content compositions

Abstract

It has unexpectedly been found that the combination of (1) an alkylated diphenylamine, (2) a sulfurized olefin/fatty oil and/or an ashless dialkyldithiocarbamate, and (3) an alkylated phenothiazine, is highly effective at controlling crankcase lubricant oxidation and deposit formation. The present invention includes lubricating compositions, lubricating additives, and methods for improving the antioxidancy and/or deposit formation properties of a lubricating composition.

Claims

1. A lubricating composition comprising a major amount of lubricating oil, and a minor amount of an oil soluble alkylated diarylamine, an oil soluble alkylated phenothiazine, and an oil soluble sulfurized compound, said sulfurized compound selected from the group consisting of sulfurized olefins and sulfurized fatty oils.

2. The lubricating composition according to claim 1 wherein said lubricating oil is selected from the group consisting of paraffinic oils, naphthenic oils, aromatic oils, and synthetic oils and mixtures thereof.

3. The lubricating composition according to claim 1 wherein the alkylated diarylamine has a concentration of about 0.05 to 2.5 wt % in the lubricating composition.

4. The lubricating composition according to claim 1 wherein the alkylated diarylamine is selected from the group consisting of:

alkylated diphenylamine, alkylated 3-hydroxydiphenylamine, N-phenyl-1,2-phenylenediamine, N-phenyl-1,4-phenylenediamine, monobutyldiphenylamine, dibutyldiphenylamine, monooctyldiphenylamine, dioctyldiphenylamine, monononyldiphenylamine, dinonyldiphenylamine, monotetradecyldiphenylamine, ditetradecyldiphenylamine, phenyl-alpha-naphthylamine, monooctyl phenyl-alpha-naphthylamine, phenyl-beta-naphthylamine, monoheptyldiphenylamine, diheptyldiphenylamine, p-oriented styrenated diphenylamine, mixed butyloctyldiphenylamine, and mixed octylstryryldiphenylamine.

5. The lubricating composition according to claim 1 wherein said alkylated phenothiazine has a concentration of about 0.05 to 2.5 wt % in the lubricating composition.

6. The lubricating composition according to claim 1 wherein said alkylated phenothiazine has the chemical formula:

wherein R1 is a linear or branched C4-C24 alkyl, aryl, heteroalkyl or alkylaryl group and R2 is hydrogen or a linear or branched C4-C24 alkyl, aryl, heteroalkyl, or alkylaryl group.

7. The lubricating composition according to claim 1 wherein said alkylated phenothiazine is selected from the group consisting of monotetradecylphenothiazine, ditetradecylphenothiazine, monodecylphenothiazine, didecylphenothiazine, monononylphenothiazine, dinonylphenothiazine, monoctylphenothiazine dioctylphenothiazine, monobutylphenothiazine, dibutylphenothiazine, monostyrylphenothiazine, distyrylphenothiazine, butyloctylphenothiazine, and styryloctylphenothiazine.

8. The lubricating composition according to claim 1 wherein said sulfurized compound has a concentration sufficient to provide from about 150 to 2500 ppm of sulfur in the lubricating composition.

9. The lubricating composition according to claim 1 wherein said sulfurized olefin is selected from the group consisting of sulfurized alpha-olefins, sulfurized isomerized alpha-olefins, sulfurized branched olefins, sulfurized cyclic olefins, and combinations thereof.

10. The lubricating composition according to claim 1 wherein said sulfurized fatty oil is selected from the group consisting of sulfurized corn oil, sulfurized canola oil, sulfurized cottonseed oil, sulfurized grapeseed oil, sulfurized olive oil, sulfurized palm oil, sulfurized peanut oil, sulfurized coconut oil, sulfurized rapeseed oil, sulfurized sesame seed oil, sulfurized soybean oil, sulfurized sunflower seed oil, sulfurized tallow, sulfurized fish oil and combinations thereof.

11. The lubricating composition according to claim 1 additionally comprising an ashless dialkyldithiocarbamate.

12. The lubricating composition according to claim 11 wherein said ashless dialkyldithiocarbamate has a concentration sufficient to provide from about 150 to 2500 ppm of sulfur in the lubricating composition.

13. The lubricating composition according to claim 11 wherein said ashless dialkyldithiocarbanate is selected from the group consisting of:

methylenebis(dialkyldithiocarbamate), ethylenebis(dialkyldithiocarbamate), isobutyl disulfide-2,2′

-bis(dialkyldithiocarbamate), dibutyl-N,N-dibutyl-(dith iocarbamyl)succinate, 2-hydroxypropyl dibutyldithiocarbamate, butyl(dibutyldithiocarbamyl)acetate, S-carbomethoxy-ethyl-N,N-dibutyl dithiocarbamate, hydroxyalkyl substituted dialkyldithiocarbamates, dithiocarbamates prepared from unsaturated compounds, dithiocarbamates prepared from norbornylene, and dithocarbamates prepared from epoxides.

14. The lubricating composition according to claim 1 additionally comprising at least one additional component selected from the group consisting of:

dispersants, detergents, anti-wear additives, antioxidants, friction modifiers, anti-foaming additives, pour point depressants, and viscosity index improvers.

15. The lubricating composition according to claim 1, wherein the lubricating composition contains 250 to 900 ppm phosphorus.

16. The lubricating composition according to claim 1, wherein the lubricating composition contains zero to 250 ppm phosphorus.

80. A method for lubricating an engine comprising lubricating said engine with the lubricating composition of claim 1.

17. A lubricating composition comprising a major amount of lubricating oil, and a minor amount of an oil soluble alkylated diarylamine, an oil soluble alkylated phenothiazine, and an oil soluble ashless dialkyldithiocarbamate.

18. The lubricating composition according to claim 17 wherein said lubricating oil is selected from the group consisting of paraffinic oils, naphthenic oils, aromatic oils, and synthetic oils and mixtures thereof.

19. The lubricating composition according to claim 17 wherein the alkylated diarylamine has a concentration of about 0.05 to 2.5 wt % in the lubricating composition.

20. The lubricating composition according to claim 17 wherein the alkylated diarylamine is selected from the group consisting of:

alkylated diphenylamine, alkylated 3-hydroxydiphenylamine, N-phenyl-1,2-phenylenediamine, N-phenyl-1,4-phenylenediamine, monobutyldiphenyl amine, dibutyldiphenylamine, monooctyldiphenylamine, dioctyldiphenylamine, monononyldiphenylamine, dinonyldiphenylamine, monotetradecyldiphenylamine, ditetradecyldiphenylamine, phenyl-alpha-naphthylamine, monooctyl phenyl-alpha-naphthylamine, phenyl-beta-naphthylamine, monoheptyldiphenylamine, diheptyldiphenylamine, p-oriented styrenated diphenylamine, mixed butyloctyldiphenylamine, and mixed octylstryryldiphenylamine.

21. The lubricating composition according to claim 17 wherein said alkylated phenothiazine has a concentration of about 0.05 to 2.5 wt % in the lubricating composition.

22. The lubricating composition according to claim 17 wherein said alkylated phenothiazine has the chemical formula:

wherein R1 is a linear or branched C4-C24 alkyl, aryl, heteroalkyl or alkylaryl group and R2 is hydrogen or a linear or branched C4-C24 alkyl, aryl, heteroalkyl, or alkylaryl group.

23. The lubricating composition according to claim 17 wherein said alkylated phenothiazine is selected from the group consisting of monotetradecylphenothiazine, ditetradecylphenothiazine, monodecylphenothiazine, didecylphenothiazine, monononylphenothiazine, dinonylphenothiazine, monooctylphenothiazine, dioctylphenothiazine monobutylphenothiazine, dibutylphenothiazine, monostyrylphenothiazine, distyrylphenothiazine, butyloctylphenothiazine, and styryloctylphenothiazine.

24. The lubricating composition according to claim 17 wherein said ashless dialkyldithiocarbamate has a concentration sufficient to provide from about 150 to 2500 ppm of sulfur in the lubricating composition.

25. The lubricating composition according to claim 17 wherein said ashless dialkyldithiocarbamate is selected from the group consisting of:

methylenebis(dialkyldithiocarbamate), ethylenebis(dialkyldithiocarbamate), isobutyl disulfide-2,2′

-bis(dialkyldithiocarbamate), dibutyl-N,N-dibutyl-(dithiocarbamyl)succinate, 2-hydroxypropyl dibutyldithiocarbamate, butyl(dibutyldithiocarbamyl)acetate, S-carbomethoxy-ethyl-N,N-dibutyl dithiocarbamate, hydroxyalkyl substituted dialkyldithiocarbamates, dithiocarbamates prepared from unsaturated compounds, dithiocarbamates prepared from norbornylene, and dithiocarbamates prepared from epoxides.

26. The lubricating composition according to claim 17 additionally comprising at least one sulfurized compound, said sulfurized compound selected from the group consisting of sulfurized olefins and sulfurized fatty oils.

27. The lubricating composition according to claim 17 additionally comprising at least one additional component selected from the group consisting of:

dispersants, detergents, anti-wear additives, antioxidants, friction modifiers, anti-foaming additives, pour point depressants, and viscosity index improvers.

28. The lubricating composition according to claim 17, wherein the lubricating composition contains 250 to 900 ppm phosphorus.

29. The lubricating composition according to claim 17, wherein the lubricating composition contains zero to 250 ppm phosphorus.

30. A lubricating additive comprising an oil soluble alkylated diarylamine, an oil soluble alkylated phenothiazine, and an oil soluble sulfurized compound, said sulfurized compound selected from the group consisting of sulfurized olefins and sulfurized fatty oils, wherein said lubricating additive forms a lubricating composition when added to a lubricating oil.

31. The lubricating additive according to claim 30 wherein the alkylated diarylamine has a concentration sufficient to constitute about 0.05 to 2.5 wt % in the lubricating composition.

32. The lubricating additive according to claim 30 wherein the alkylated diarylamine is selected from the group consisting of:

alkylated diphenylamine, alkylated 3-hydroxydiphenylamine, N-phenyl-1,2-phenylenediamine, N-phenyl-1,4-phenylenediamine, monobutyldiphenylamine, dibutyldiphenylamine, monooctyldiphenylamine, dioctyldiphenylamine, monononyldiphenylamine, dinonyldiphenylamine, monotetradecyldiphenylamine, ditetradecyldiphenylamine, phenyl-alpha-naphthylamine, monooctyl phenyl-alpha-naphthylamine, phenyl-beta-naphthylamine, monoheptyldiphenylamine, diheptyldiphenylamine, p-oriented styrenated diphenylamine, mixed butyloctyldiphenylamine, and mixed octylstryryldiphenylamine.

33. The lubricating additive according to claim 30 wherein said alkylated phenothiazine has a concentration sufficient to constitute about 0.05 to 2.5 wt % in the lubricating composition.

34. The lubricating additive according to claim 30 wherein said alkylated phenothiazine has the chemical formula:

wherein R1 is a linear or branched C4-C24 alkyl, aryl, heteroalkyl or alkylaryl group and R2 is hydrogen or a linear or branched C4-C24 alkyl, aryl, heteroalkyl, or alkylaryl group.

35. The lubricating additive according to claim 30 wherein said alkylated phenothiazine is selected from the group consisting of monotetradecylphenothiazine, ditetradecylphenothiazine, monodecylphenothiazine, didecylphenothiazine, monononylphenothiazine, dinonylphenothiazine, monoctylphenothiazine and dioctylphenothiazine, monobutylphenothiazine, dibutylphenothiazine, monostyrylphenothiazine, distyrylphenothiazine, butyloctylphenothiazine, and styryloctylphenothiazine.

36. The lubricating additive according to claim 30 wherein said sulfurized compound has a concentration sufficient to provide from about 150 to 2500 ppm of sulfur in the lubricating composition.

37. The lubricating additive according to claim 30 wherein said sulfurized olefin is selected from the group consisting of sulfurized alpha-olefins, sulfurized isomerized alpha-olefins, sulfurized branched olefins, sulfurized cyclic olefins, and combinations thereof.

38. The lubricating additive according to claim 30 wherein said sulfurized fatty oil is selected from the group consisting of sulfurized corn oil, sulfurized canola oil, sulfurized cottonseed oil, sulfurized grapeseed oil, sulfurized olive oil, sulfurized palm oil, sulfurized peanut oil, sulfurized coconut oil, sulfurized rapeseed oil, sulfurized sesame seed oil, sulfurized soybean oil, sulfurized sunflower seed oil, sulfurized tallow, sunfurized fish oil, and combinations thereof.

39. The lubricating additive according to claim 30 additionally comprising an ashless dialkyldithiocarbamate.

40. The lubricating additive according to claim 39 wherein said ashless dialkyldithiocarbamate has a concentration sufficient to provide from about 150 to 2500 ppm of sulfur in the lubricating composition.

41. The lubricating additive according to claim 39 wherein said ashless dialkyldithiocarbamate is selected from the group consisting of:

methylenebis(dialkyldithiocarbamate), ethylenebis(dialkyldithiocarbamate), isobutyl disulfide-2,2′

-bis(dialkyldithiocarbamate), dibutyl-N,N-dibutyl-(dithiocarbamyl)succinate, 2-hydroxypropyl dibutyldithiocarbamate, butyl(dibutyldithiocarbamyl)acetate, S-carbomethoxy-ethyl-N,N-dibutyl dithiocarbamate, hydroxyalkyl substituted dialkyldithiocarbamates, dithiocarbamates prepared from unsaturated compounds, dithiocarbamates prepared from norbornylene, and dithiocarbamates prepared from epoxides.

42. The lubricating additive according to claim 30 additionally comprising at least one additional component selected from the group consisting of:

dispersants, detergents, anti-wear additives, antioxidants, friction modifiers, anti-foaming additives, pour point depressants, and viscosity index improvers.

43. The lubricating additive according to claim 30, wherein the lubricating composition contains 250 to 900 ppm phosphorus.

44. The lubricating composition according to claim 30, wherein the lubricating composition contains zero to 250 ppm phosphorus.

45. A lubricating additive comprising an oil soluble alkylated diarylamine, an oil soluble alkylated phenothiazine, and an oil soluble ashless dialkyldithiocarbamate, wherein said lubricating additive forms a lubricating composition when added to a lubricating oil.

46. The lubricating additive according to claim 45 wherein the alkylated diarylamine has a concentration sufficient to constitute about 0.05 to 2.5 wt % in the lubricating composition.

47. The lubricating additive according to claim 45 wherein the alkylated diarylamine is selected from the group consisting of:

alkylated diphenylamine, alkylated 3-hydroxydiphenylamine, N-phenyl-1,2-phenylenediamine, N-phenyl-1,4-phenylenediamine, monobutyldiphenylamine, dibutyldiphenylamine, monooctyldiphenylamine, dioctyldiphenylamine, monononyldiphenylamine, dinonyldiphenylamine, monotetradecyldiphenylamine, ditetradecyldiphenylamine, phenyl-alpha-naphthylamine, monooctyl phenyl-alpha-naphthylamine, phenyl-beta-naphthylamine, monoheptyldiphenylamine, diheptyldiphenylamine, p-oriented styrenated diphenylamine, mixed butyloctyldiphenylamine, and mixed octylstryryldiphenylamine.

48. The lubricating additive according to claim 45 wherein said alkylated phenothiazine has a concentration sufficient to constitute about 0.05 to 2.5 wt % in the lubricating composition.

49. The lubricating additive according to claim 45 wherein said alkylated phenothiazine has the chemical formula:

wherein R1 is a linear or branched C4-C24 alkyl, aryl, heteroalkyl or alkylaryl group and R2 is hydrogen or a linear or branched C4-C24 alkyl, aryl, heteroalkyl, or alkylaryl group.

50. The lubricating additive according to claim 45 wherein said alkylated phenothiazine is selected from the group consisting of monotetradecylphenothiazine, ditetradecylphenothiazine, monodecylphenothiazine, didecylphenothiazine, monononylphenothiazine, dinonylphenothiazine, monooctylphenothiazine, dioctylphenothiazine, monobutylphenothiazine, dibutylphenothiazine, monostyrylphenothiazine, distyrylphenothiazine, butyloctylphenothiazine, and styryloctylphenothiazine.

51. The lubricating additive according to claim 45 wherein said ashless dialkyldithiocarbamate has a concentration sufficient to provide from about 150 to 2500 ppm of sulfur in the lubricating composition.

52. The lubricating additive according to claim 45 wherein said ashless dialkyldithiocarbamate is selected from the group consisting of:

methylenebis(dialkyldithiocarbamate), ethylenebis(dialkyldithiocarbamate), isobutyl disulfide-2,2′

-bis(dialkyldithiocarbamate), dibutyl-N,N-dibutyl-(dithiocarbamyl)succinate, 2-hydroxypropyl dibutyldithiocarbamate, butyl(dibutyldithiocarbamyl)acetate, S-carbomethoxy-ethyl-N,N-dibutyl dithiocarbamate, hydroxyalkyl substituted dialkyldithiocarbamates, dithiocarbamates prepared from unsaturated compounds, dithiocarbamates prepared from norbornylene, and dithiocarbamates prepared from epoxides.

53. The lubricating additive according to claim 45 additionally comprising at least one sulfurized compound, said sulfurized compound selected from the group consisting of sulfurized olefins and sulfurized fatty oils.

54. The lubricating additive according to claim 45 additionally comprising at least one additional component selected from the group consisting of:

dispersants, detergents, anti-wear additives, antioxidants, friction modifiers, anti-foaming additives, pour point depressants, and viscosity index improvers.

55. The lubricating additive according to claim 45, wherein the lubricating composition contains 250 to 900 ppm phosphorus.

56. The lubricating additive according to claim 45, wherein the lubricating composition contains zero to 250 ppm phosphorus.

57. A method for improving the antioxidancy and/or deposit formation properties of a lubricating composition comprising the step of including in the lubricating composition an oil soluble alkylated diarylamine, an oil soluble alkylated phenothiazine, and an oil soluble sulfurized compound, said sulfurized compound selected from the group consisting of sulfurized olefins and sulfurized fatty oils.

58. The method according to claim 57 wherein the alkylated diarylamine has a concentration of about 0.05 to 2.5 wt % in the lubricating composition.

59. The method according to claim 57 wherein the alkylated diarylamine is selected from the group consisting of:

alkylated diphenylamine, alkylated 3-hydroxydiphenylamine, N-phenyl-1,2-phenylenediamine, N-phenyl-1,4-phenylenediamine, monobutyldiphenylamine, dibutyldiphenylamine, monooctyldiphenylamine, dioctyldiphenylamine, monononyldiphenylamine, dinonyldiphenylamine, monotetradecyldiphenylamine, ditetradecyldiphenylamine, phenyl-alpha-naphthylamine, monooctyl phenyl-alpha-naphthylamine, phenyl-beta-naphthylamine, monoheptyldiphenylamine, diheptyldiphenylamine, p-oriented styrenated diphenylamine, mixed butyloctydiphenylamine, and mixed octylstryryldiphenylamine.

60. The method according to claim 57 wherein said alkylated phenothiazine has a concentration of about 0.05 to 2.5 wt % in the lubricating composition.

61. The method according to claim 57 wherein said alkylated phenothiazine has the chemical formula:

wherein R1 is a linear or branched C4-C24 alkyl, aryl, heteroalkyl or alkylaryl group and R2 is hydrogen or a linear or branched C4-C24 alkyl, aryl, heteroalkyl, or alkylaryl group.

62. The method according to claim 57 wherein said alkylated phenothiazine is selected from the group consisting of monotetradecylphenothiazine, ditetradecylphenothiazine, monodecylphenothiazine, didecylphenothiazine, monononylphenothiazine, dinonylphenothiazine, monoctylphenothiazine, dioctylphenothiazine, monobutylphenothiazine, dibutylphenothiazine, monostyrylphenothiazine, distyrylphenothiazine, butyloctylphenothiazine, and styryloctylphenothiazine.

63. The method according to claim 57 wherein said sulfurized compound has a concentration sufficient to provide from about 150 to 2500 ppm of sulfur in the lubricating composition.

64. The method according to claim 57 wherein said sulfurized olefin is selected from the group consisting of sulfurized alpha-olefins, sulfurized isomerized alpha-olefins, sulfurized branched olefins, sulfurized cyclic olefins, and combinations thereof.

65. The method according to claim 57 wherein said sulfurized fatty oil is selected from the group consisting of sulfurized corn oil, sulfurized canola oil, sulfurized cottonseed oil, sulfurized grapeseed oil, sulfurized olive oil, sulfurized palm oil, sulfurized peanut oil, sulfurized coconut oil, sulfurized rapeseed oil, sulfurized sesame seed oil, sulfurized soybean oil, sulfurized sunflower seed oil, sulfurized tallow, sulfurized fish oil, and combinations thereof.

66. The method according to claim 57 additionally comprising the step of including an ashless dialkyldithiocarbamate in the lubricating composition.

67. The method according to claim 66 wherein said ashless dialkyldithiocarbamate has a concentration sufficient to provide from about 150 to 2500 ppm of sulfur in the lubricating composition.

68. The method according to claim 66 wherein said ashless dialkyidithiocarbamate is selected from the group consisting of:

methylenebis(dialkyldithiocarbamate), ethylenebis(dialkyldithiocarbamate), isobutyl disulfide-2,2′

-bis(dialkyldithiocarbamate), dibutyl-N,N-dibutyl-(dithiocarbamyl)succinate, 2-hydroxypropyl dibutyldithiocarbamate, butyl(dibutyldithiocarbamyl)acetate, S-carbomethoxy-ethyl-N,N-dibutyl dithiocarbamate, hydroxyalkyl substituted dialkyldithiocarbamates, dithiocarbamates prepared from unsaturated compounds, dithiocarbamates prepared from norbornylene, and dithiocarbamates prepared from epoxides.

69. The method according to claim 57 additionally comprising the step of including at least one additional component in the lubricating composition, said at least one additional component selected from the group consisting of:

dispersants, detergents, anti-wear additives, antioxidants, friction modifiers, anti-foaming additives, pour point depressants, and viscosity index improvers.

70. A method for improving the antioxidancy and/or deposit formation properties of a lubricating composition comprising the step of including in the lubricating composition an oil soluble alkylated diarylamine, an oil soluble alkylated phenothiazine, and an oil soluble ashless dialkyldithiocarbamate.

71. The method according to claim 70 wherein the alkylated diarylamine has a concentration of about 0.05 to 2.5 wt % in the lubricating composition.

72. The method according to claim 70 wherein the alkylated diarylamine is selected from the group consisting of:

alkylated diphenylamine, alkylated 3-hydroxydiphenylamine, N-phenyl-1,2-phenylenediamine, N-phenyl-1,4-phenylenediamine, monobutyldiphenylamine, dibutyldiphenylamine, monooctyldiphenylamine, dioctyldiphenylamine, monononyldiphenylamine, dinonyldiphenylamine, monotetradecyldiphenylamine, ditetradecyldiphenylamine, phenyl-alpha-naphthylamine, monooctyl phenyl-alpha-naphthylamine, phenyl-beta-naphthylamine, monoheptyldiphenylamine, diheptyldiphenylamine, p-oriented styrenated diphenylamine, mixed butyloctyldiphenylamine, and mixed octylstryryldiphenylamine.

73. The method according to claim 70 wherein said alkylated phenothiazine has a concentration of about 0.05 to 2.5 wt % in the lubricating composition.

74. The method according to claim 70 wherein said alkylated phenothiazine has the chemical formula:

wherein R1 is a linear or branched C4-C24 alkyl, heteroalkyl or alkylaryl group and R2 is hydrogen or a linear or branched alkyl, heteroalkyl, or alkylaryl group.

75. The method according to claim 70 wherein said alkylated phenothiazine is selected from the group consisting of monotetradecylphenothiazine, ditetradecylphenothiazine, monodecylphenothiazine, didecylphenothiazine, monononylphenothiazine, dinonylphenothiazine, monoctylphenothiazine, dioctylphenothiazine, monobutylphenothiazine, dibutylphenothiazine, monostyrylphenothiazine, distyrylphenothiazine, butyloctylphenothiazine, and styryloctylphenothiazine.

76. The method according to claim 70 wherein said ashless dialkyldithiocarbamate has a concentration sufficient to provide from about 150 to 2500 ppm of sulfur in the lubricating composition.

77. The method according to claim 70 wherein said ashless dialkyldithiocarbamate is selected from the group consisting of:

methylenebis(dialkyldithiocarbamate), ethylenebis(dialkyldithiocarbamate), isobutyl disulfide-2,2′

-bis(dialkyldithiocarbamate), dibutyl-N,N-dibutyl-(dithiocarbamyl)succinate, 2-hydroxypropyl dibutyldithiocarbamate, butyl(dibutyidithiocarbamyl)acetate, S-carbomethoxy-ethyl-N,N-dibutyl dithiocarbamate, hydroxyalkyl substituted dialkyldithiocarbamates, dithiocarbamates prepared from unsaturated compounds, dithiocarbamates prepared from norbornylene, and dithiocarbamates prepared from epoxides.

78. The method according to claim 70 additionally comprising the step of including at least one sulfurized compound in said lubricating composition, said sulfurized compound selected from the group consisting of sulfurized olefins and sulfurized fatty oils.

79. The method according to claim 70 additionally comprising the step of including at least one additional component in said lubricating composition, said at least one additional component selected from the group consisting of:

dispersants, detergents, anti-wear additives, antioxidants, friction modifiers, anti-foaming additives, pour point depressants, and viscosity index improvers.