Cycloalkyl phenylenediamines as deposit control agents for lubricants

1 . A composition comprising a fluid subject to oxidative degradation and an amount of at least one N-cycloalkyl-substituted phenylenediamine additive sufficient to stabilize said fluid against the formation of deposits, wherein said additive is of the structure:

R 1 is a cycloalkyl ring selected from the group consisting of:

wherein

R 5 , R 6 , R 7 , and R 8 are independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, allyl, methyallyl, isobutenyl, alkenyl, furfuryl, benzyl, alkaryl, and phenyl;

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and wherein Q and m are as defined above;

and

m is an integer of 1 to 8; and

wherein, when X and Y are para to each other, R 2 , R 3 , and R 4 are in an interrelated relationship selected from the group consisting of:

(A) R 2 is a cycloalkyl ring independently selected from the group consisting of:

wherein

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and wherein Q and m are as defined above;

R 3 is an independently selected cycloalkyl ring of the structure:

wherein Q and m are as defined above;

and

R 4 is selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms, aryl, alkaryl, cycloalkyl, and alkenyl of from 3 to about 36 carbon atoms, all optionally containing a nitrogen, oxygen, or sulfur atom, hydrogen, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—;

(B) R 2 is a cycloalkyl ring independently selected from the group consisting of:

wherein

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and

wherein Q and m are as defined above;

and

R 3 and R 4 are independently selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms, aryl, alkaryl, cycloalkyl, and alkenyl of from 3 to about 36 carbon atoms, all optionally containing a nitrogen atom, hydrogen, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that R 3 and R 4 are not 2-hydroxyethyl, that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—, and that R 3 and R 4 are not both hydrogen;

(C) R 3 is a cycloalkyl ring independently selected from the group consisting of:

wherein

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and wherein Q and m are as defined above;

and

R 2 and R 4 are independently selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms, aryl, alkaryl, cycloalkyl, and alkenyl of from 3 to about 36 carbon atoms, all optionally containing a nitrogen atom, hydrogen, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that R 3 and R 4 are not 2-hydroxyethyl, and that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—;

(D) R 2 , R 3 , and R 4 are independently selected from the group consisting of alkyls of from 3 to about 36 carbon atoms, alkenyls of from 3 to about 36 carbon atoms, aryl, alkaryl, and cycloalkyl, all optionally containing a nitrogen atom, hydrogen, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that R 3 and R 4 are not 2-hydroxyethyl, that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—; and,

(1) at least two of R 2 , R 3 , and R 4 are independently selected from the group consisting of alkyls of from 3 to about 36 carbon atoms, alkenyls of from 3 to about 36 carbon atoms, wherein said alkyls or alkenyls are branched on the carbon bonded to the phenylenediamine nitrogen; and that

(2) when R 1 is a 2,2,6,6-tetramethylpiperidinyl, R 3 can be hydrogen; and

wherein, when X and Y are ortho or meta to each other, R 2 , R 3 , and R 4 are in an interrelated relationship selected from the group consisting of:

(E) R 2 is a cycloalkyl ring independently selected from the group consisting of:

wherein

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and wherein Q and m are as defined above;

and

R 3 and R 4 are independently selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms, aryl, alkaryl, and cycloalkyl, all optionally containing a nitrogen, oxygen, or sulfur atom, hydrogen, alkenyl of from 3 to about 36 carbon atoms, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—, and that R 3 and R 4 are not both hydrogen;

(F) R 2 , R 3 , and R 4 are independently selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms and cycloalkyl, all optionally containing a nitrogen, oxygen, or sulfur atom, hydrogen, aryl, alkaryl, alkenyl of from 3 to about 36 carbon atoms, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S;provided that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—; and wherein said phenylenediamine is in the form of a free base, or an oil-soluble salt.

2 . The composition of claim 1 wherein the N-cycloalkyl substituted phenylenediamine has the structure:

where m is 0, 1, 2, or 3, R 2 , R 3 and R 4 are independently selected from the group consisting of alkyl, branched alkyl, cycloalkyl, alkenyl of 3 to about 36 carbons, alkaryl, and aryl, all optionally containing an N, O, or S atom, and hydrogen; and R 5 , R 6 , R 7 , and R 8 are independently selected from the group consisting of linear or branched alkyl of 1 to about 20 carbons and hydrogen; with the proviso that at least two of R 2 , R 3 , and R 4 are independently alkyls branched on the carbon bonded to the phenylenediamine nitrogen.

3 . The composition of claim 1 wherein the N,N′-dicycloalkyl substituted phenylenediamine has the structure:

where m and n are independently 0, 1, 2, or 3, R 3 and R 4 are independently selected from the group consisting of alkyl, branched alkyl, cycloalkyl, alkenyl of 3 to about 36 carbons, alkaryl, and aryl; optionally containing an N, O, or S atom, and hydrogen; and R 5 , R 6 , R 7 , and R 8 are independently selected from the group consisting of linear or branched alkyls of 1 to about 20 carbons, and hydrogen.

4 . The composition of claim 1 wherein the N-cycloalkyl-substituted phenylenediamine has the structure:

where m, n, and p are independently 0, 1, 2, or 3, and R 4 is selected from the group consisting of linear or branched alkyl, cycloalkyl, allyl, alkenyl, alkaryl, and aryl, all optionally containing a N, O, or S atom; and R 5 , R 6 , R 7 , and R 8 are independently selected from the group consisting of linear or branched alkyl of 1 to about 20 carbons, and hydrogen.

5 . The composition of claim 1 further comprising an organic material subject to oxidative, thermal, or light-induced degradation.

6 . The composition of claim 5 wherein the organic material is selected from the group consisting of natural functional fluids, synthetic functional fluids, and mixtures thereof.

7 . The composition of claim 6 wherein the functional fluid is selected from the group consisting of lubricating oil, grease, fuel, natural oils, and mixtures thereof.

8 . The composition of claim 7 wherein the functional fluid is a lubricating oil selected from the group consisting of engine oils, transmission fluids, hydraulic fluids, gear oils, marine cylinder oils, compressor oils, refrigeration lubricants, and mixtures thereof.

9 . The composition of claim 8 wherein the lubricating oil has a viscosity of about 1.5 to about 2000 centistokes (cSt) at 100° C.

10 . The composition of claim 8 further comprising at least one lubricating oil additive.

11 . The composition of claim 10 wherein the lubricating oil additive is selected from the group consisting of antioxidants, anti-wear agents, detergents, rust inhibitors, dehazing agents, demulsifying agents, metal deactivating agents, friction modifiers, pour point depressants, antifoaming agents, co-solvents, package compatibilizers, corrosion-inhibitors, ashless dispersants, dyes, extreme pressure agents, and mixtures thereof.

12 . The composition of claim 10 wherein the lubricating oil additive is selected from the group consisting of alkylated diphenylamines, alkylated hindered phenolics, alkylated substituted or unsubstituted phenylenediamines, alkylated oil soluble copper compounds, alkylated sulfur-containing compounds known to impart oxidation stability, and mixtures thereof.

13 . The composition of claim 12 wherein the alkylated sulfur-containing compound is selected from the group consisting of a phenothiazine, sulfurized olefin, thiocarbamate, sulfur-bearing hindered phenolic, zinc dialkyldithiophosphate, and mixtures thereof.

14 . The composition of claim 10 wherein the lubricating oil additive is selected from the group consisting of fatty acid esters or amides, organo molybdenum compounds, molybdenum dialkyldithiocarbamates, molybdenum dialkyl dithiophosphates, molybdenum disulfides, tri-molybdenum cluster dialkyldithiocarbamates, non-sulfur molybdenum compounds, and mixtures thereof.

15 . The composition of claim 10 wherein the lubricating oil additive is selected from the group consisting of zinc dialkyldithiophosphates, zinc diaryldithiophosphates, dialkyldithiophosphate esters, diaryl dithiophosphate esters, and mixtures thereof.

16 . The composition of claim 10 wherein the lubricating oil additive has a phosphorus content of less than about 0.08 weight percent.

17 . The composition of claim 10 further comprising at least one diaromatic amine compound in an amount of about 0.1 to about 10 weight %, based on the total weight of the composition.

18 . The composition of claim 5 comprising a mixture of at least two N-cycloalkyl substituted phenylenediamine compounds.

19 . The composition of claim 6 further comprising an additive package comprising about 1 to about 75 weight% of said N-cycloalkyl substituted phenylenediamine compound.

20 . A method for stabilizing an organic material subject to oxidative, thermal, or light-induced degradation comprising adding to the organic material a stabilizing amount of at least one N-cycloalkyl-substituted phenylenediamine additive of the structure:

wherein

X is

Y is

R 1 is a cycloalkyl ring selected from the group consisting of:

wherein

R 5 , R 6 , R 7 , and R 8 are independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, allyl, methyallyl, isobutenyl, alkenyl, furfuryl, benzyl, alkaryl, and phenyl;

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and wherein Q and m are as defined above;

and

m is an integer of 1 to 8; and

wherein, when X and Y are para to each other, R 2 , R 3 , and R 4 are in an interrelated relationship selected from the group consisting of:

(A) R 2 is a cycloalkyl ring independently selected from the group consisting of:

wherein

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and wherein Q and m are as defined above;

R 3 is an independently selected cycloalkyl ring of the structure:

wherein Q and m are as defined above;

and

R 4 is selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms, aryl, alkaryl, cycloalkyl, and alkenyl of from 3 to about 36 carbon aims, all optionally containing a nitrogen, oxygen, or sulfur atom, hydrogen, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that Z is not—CH 2 CH 2 — or —CH 2 CH(CH 3 )—;

(B) R 2 is a cycloalkyl ring independently selected from the group consisting of:

wherein

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and

wherein Q and m are as defined above;

and

R 3 and R 4 are independently selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms, aryl, alkaryl, cycloalkyl and alkenyl of from 3 to about 36 carbon atoms, all optionally containing a nitrogen atom, hydrogen, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that R 3 and R 4 are not 2-hydroxyethyl, that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—, and that R 3 and R 4 are not both hydrogen;

(C) R 3 is a cycloalkyl ring independently selected from the group consisting of:

wherein

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and wherein Q and m are as defined above;

and

R 2 and R 4 are independently selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms, aryl, alkaryl, cycloalkyl, and alkenyl of from 3 to about 36 carbon atoms, all optionally containing a nitrogen atom, hydrogen, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that R 3 and R 4 are not 2-hydroxyethyl, and that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—;

(D) R 2 , R 3 , and R 4 are independently selected from the group consisting of alkyls of from 3 to about 36 carbon atoms, alkenyls of from 3 to about 36 carbon atoms, aryl, alkaryl, and cycloalkyl, all optionally containing a nitrogen atom, hydrogen, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that R 3 and R 4 are not 2-hydroxyethyl, that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—; and

(1) at least two of R 2 , R 3 , and R 4 are independently selected from the group consisting of alkyls of from 3 to about 36 carbon atoms, alkenyls of from 3 to about 36 carbon atoms, wherein said alkyls or alkenyls are branched on the carbon bonded to the phenylenediamine nitrogen; and that

(2) when R 1 is a 2,2,6,6-tetramethylpiperidinyl, R 3 can be hydrogen; and

wherein, when X and Y are ortho or meta to each other, R 2 , R 3 , and R 4 are in an interrelated relationship selected from the group consisting of:

(E) R 2 is a cycloalkyl ring independently selected from the group consisting of:

wherein

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and wherein Q and m are as defined above;

and

R 3 and R 4 are independently selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms, aryl, alkaryl, and cycloalkyl, all optionally containing a nitrogen, oxygen, or sulfur atom, hydrogen, alkenyl of from 3 to about 36 carbon atoms, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that Z is not—CH 2 CH 2 — or —CH 2 CH(CH 3 )—, and that R 3 and R 4 are not both hydrogen;

(F) R 2 , R 3 , and R 4 are independently selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms and cycloalkyl, all optionally containing a nitrogen, oxygen, or sulfur atom, hydrogen, aryl, alkaryl, alkenyl of from 3 to about 36 carbon atoms, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S;provided that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—;

and wherein said phenylenediamine is in the form of a free base, or an oil-soluble salt.

21 . A compound comprising the structure:

R 1 is a cycloalkyl ring selected from the group consisting of:

wherein

R 5 , R 6 , R 7 , and R 8 are independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, allyl, methyallyl, isobutenyl, alkenyl, furfuryl, benzyl, alkaryl, and phenyl;

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and wherein Q and m are as defined above;

and

m is an integer of 1 to 8; and

wherein, when X and Y are para to each other, R 2 , R 3 , and R 4 are in an interrelated relationship selected from the group consisting of:

(A) R 2 is a cycloalkyl ring independently selected from the group consisting of:

wherein

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and wherein Q and m are as defined above;

R 3 is an independently selected cycloalkyl ring of the structure:

wherein Q and m are as defined above;

and

R 4 is selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms, aryl, alkaryl, cycloalkyl, and alkenyl of from 3 to about 36 carbon atoms, all optionally containing a nitrogen, oxygen, or sulfur atom, hydrogen, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—;

(B) R 2 is a cycloalkyl ring independently selected from the group consisting of:

wherein

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and

wherein Q and m are as defined above;

and

R 3 and R 4 are independently selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms, aryl, alkaryl, cycloalkyl, and alkenyl of from 3 to about 36 carbon atoms, all optionally containing a nitrogen atom, hydrogen, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that R 3 and R 4 are not 2-hydroxyethyl, that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—, and that R 3 and R 4 are not both hydrogen;

(C) R 3 is a cycloalkyl ring independently selected from the group consisting of:

wherein

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and wherein Q and m are as defined above;

and

R 2 and R 4 are independently selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms, aryl, alkaryl, cycloalkyl, and alkenyl of from 3 to about 36 carbon atoms, all optionally containing a nitrogen atom, hydrogen, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that R 3 and R 4 are not 2-hydroxyethyl, and that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—;

(D) R 2 , R 3 , and R 4 are independently selected from the group consisting of alkyls of from 3 to about 36 carbon atoms, alkenyls of from 3 to about 36 carbon atoms, aryl, alkaryl, and cycloalkyl, all optionally containing a nitrogen atom, hydrogen, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that R 3 and R 4 are not 2-hydroxyethyl, that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—; and

(1) at least two of R 2 , R 3 , and R 4 are independently selected from the group consisting of alkyls of from 3 to about 36 carbon atoms, alkenyls of from 3 to about 36 carbon atoms, wherein said alkyls or alkenyls are branched on the carbon bonded to the phenylenediamine nitrogen; and that

(2) when R 1 is a 2,2,6,6-tetramethylpiperidinyl, R 3 can be hydrogen; and

wherein, when X and Y are ortho or meta to each other, R 2 , R 3 , and R 4 are in an interrelated relationship selected from the group consisting of:

(E) R 2 is a cycloalkyl ring independently selected from the group consisting of:

wherein

each Q is C(R 9 )(R 10 ), wherein each R 9 and R 10 is independently selected from the group consisting of hydrogen, linear and branched alkyl groups of from 1 to 20 carbon atoms, and cycloalkyl;

wherein R 11 is H, linear and branched alkyl groups of from 1 to 20 carbon atoms, cycloalkyl, aryl, alkaryl, and O; and wherein Q and m are as defined above;

and

R 3 and R 4 are independently selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms, aryl, alkaryl, and cycloalkyl, all optionally containing a nitrogen, oxygen, or sulfur atom, hydrogen, alkenyl of from 3 to about 36 carbon atoms, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S; provided that Z is not—CH 2 CH 2 — or —CH 2 CH(CH 3 )—, and that R 3 and R 4 are not both hydrogen;

(F) R 2 , R 3 , and R 4 are independently selected from the group consisting of linear or branched alkyl of from 1 to about 36 carbon atoms and cycloalkyl, all optionally containing a nitrogen, oxygen, or sulfur atom, hydrogen, aryl, alkaryl, alkenyl of from 3 to about 36 carbon atoms, and ZCO 2 R 11 , wherein Z is an alkylene or alkenyl group of from 1 to about 36 carbons, and R 11 is selected from the group consisting of linear or branched alkyl, cycloalkyl, aryl, and alkaryl, all optionally containing O, N, or S;provided that Z is not —CH 2 CH 2 — or —CH 2 CH(CH 3 )—;

and wherein said phenylenediamine is in the form of a free base, or an oil-soluble salt.

22 . A compound selected from the group consisting of:

N-(1-methyldecyl)-N′-(2,2,6,6-tetramethyl-4-piperdinyl)-p-phenylenediamine;

N-cyclohexyl-N-phenyl-o-phenylenediamine;

N,N′-dicyclohexyl-m-phenylenediamine;

N,N′-dicyclohexyl-m-toluenediamine;

N,N′-dicyclohexyl-3,5-diethyl-2,4-toluenediamine;

N,N′-dicyclohexyl-3,5-diethyl-2,6-toluenediamine;

N-cyclohexyl-N-(2-ethylhexyl)N′-phenyl-p-phenylenediamine;

N-cyclohexyl-N,N′-di(sec-butyl)-p-phenylenediamine;

N,N′-dicyclooctyl-N-ethyl-p-phenylenediamine;

N,N′-dicyclohexyl-N-isopropyl-p-phenylenediamine;

N,N′-dicyclohexyl-N-isobutyl-p-phenylenediamine;

N,N′-dicyclohexyl-N-butyl-m-phenylenediamine;

N,N′-dicyclohexyl-N-butyl-p-phenylenediamine;

N,N′-dicyclohexyl-N-isobutyl-m-phenylenediamine;

N,N′-dicyclohexyl-N-isobutyl-m-phenylenediamine;

N,N′-dicyclohexyl-N-heptyl-m-phenylenediamine;

N,N′-dicyclohexyl-N-heptyl-p-phenylenediamine;

N,N′-dicyclohexyl-N-phenyl-p-phenylenediamine;

N,N-dicyclohexyl-N′-phenyl-p-phenylenediamine;

N,N′-dicyclohexyl-N,N′-difurfuryl-p-phenylenediamine;

N,N′-dicyclohexyl-N,N′-dibenzyl-p-phenylenediamine;

N,N′-dicyclohexyl-N′-phenyl-N-heptyl-p-phenylenediamine;

N,N′-dicyclohexyl-N,N′-diethyl-p-phenylenediamine;

N,N′-dicyclohexyl-N,N′-dibutyl-m-phenylenediamine;

N,N′-dicyclohexyl-N,N′-dibutyl-p-phenylenediamine;

N,N′-dicyclohexyl-N,N′-diisobutyl-m-phenylenediamine;

N,N′-dicyclohexyl-N,N′-diisobutyl-p-phenylenediamine;

N,N′-dicyclohexyl-N,N′-diheptyl-m-phenylenediamine;

N,N′-dicyclohexyl-N,N′-diheptyl-p-phenylenediamine;

N,N′-dicyclooctyl-N,N′-diethyl-p-phenylenediamine;

N,N,N′-tricyclopentyl-p-phenylenediamine;

N,N,N′-tricyclohexyl-p-phenylenediamine;

N,N,N′-tricyclohexyl-N′-heptyl-p-phenylenediamine;

N,N,N′-tricyclohexyl-N′-propyl-p-phenylenediamine;

N,N,N′-tricyclohexyl-N′-butyl-p-phenylenediamine;

N-(2-ethylhexyl)-N,N′,N′-tricyclohexyl-p-phenylenediamine;

N,N,N′-tricyclohexyl-N′-phenyl-p-phenylenediamine;

N,N,N′,N′-tetracyclohexyl-p-phenylenediamine;

N,N′-bis(2-decalinyl)-p-phenylenediamine;

N,N′-dicyclohexyl-4,6-diisobutyl-1,3-phenylenediamine; and

N,N′-dicyclohexyl-4-isobutenyl-6-isobutyl-1,3-phenylenediamine.