ASHLESS LUBRICANT COMPOSITION
A lubricant composition with improved antioxidant capability is provided by way of an additive composition containing a metal free sulfur-containing compound, an aromatic amine, and a hindered amine. Particularly effective metal-free sulfur-containing compounds include ashless dithiocarbamates, such as methylenebis(dibutyldithiocarbamate), and sulfurized fatty acids.
1 - 16 . (canceled)
17 . A lubricating composition comprising at least 90% by weight of a lubricant basestock, and about 0.5-5% by weight of an antioxidant additive composition comprising:
(a) an ashless dithiocarbamate;
(b) a hindered amine being one or more chosen from the group consisting of:
(1) a compound of the formula
where R 26 is H, O or a hydrocarbon from 1 to 25 carbon atoms, an alkoxy radical with the oxygen bound to the nitrogen with the alkyl portion containing 1 to 25 carbon atoms, or a COR group, the R being a hydrocarbon containing from 1 to 25 carbon atoms; R 27 , R 28 , R 32 , R 33 are hydrocarbons with 1 to 25 carbon atoms; R 29 , R 31 are H or hydrocarbons with 1 to 25 carbon atoms; when n=1, R 30 is OH, H, O, NH 2 , NR 2 where R is a hydrocarbon with 1 to 25 carbon atoms, an ester group O 2 CR where R is a hydrocarbon with 1 to 25 carbon atoms, or a succinimide group; when n=2, R 30 is the diacyl radical of an aliphatic dicarboxylic acid having 4 to 12 carbon atoms;
(2) 4-stearoyloxy-2,2,6,6-tetramethylpiperidine,
(3) di(2,2,6,6-tetramethylpiperidin-4-yl) sebacate,
(4) di(1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate,
(5) bis (1-octyloxy-2,2,6, -tetramethyl-4-piperidyl) sebacate
(6) polymer-bound piperidine compound,
(7) a compound of the group consisting of 2,2,6,6-tetramethylpiperidines, 1,2,2,6,6-pentamethylpiperidines, 1-oxo-2,2,6,6-tetramethylpiperidines, and 1-alkoxy-2,2,6,6-tetramethylpiperidines, and
(8) a compound of the group consisting of di(1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, di(,2,2,6,6-tetramethylpiperidin-4-y1) sebacate and bis (1-octyloxy-2,2,6,-tetramethyl-4-piperidyl) sebacate; and
(c) a diaryl amine,
wherein the weight ratio of (a):(b):(c) is about 5:1:4.
18 . The lubricating composition according to claim 1 , wherein the additive composition comprises by weight % of the lubricating composition:
(a) the metal-free sulfur-containing compound at about 0.5%,
(b) the hindered amine at about 0.1%, and
(c) the diaryl amine at about 0.4%.
19 . The lubricating composition according to claim 1 , wherein the ashless dithiocarbamate is methlyenebis(dibutyldithiocarbamate).
20 . The lubricating composition according to claim 1 , wherein the hindered amine is chosen from the group consisting of 4-stearoyloxy-2,2,6,6-tetramethylpiperidine; di(2,2,6,6-tetramethylpiperidin-4-yl) sebacate; di(1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate; and 2,2,6,6-tetramethylpiperidinyl-4-dodecanate
21 . A lubricating composition comprising at least 90% by weight of a lubricant basestock, and about 0.5-5% by weight of an antioxidant additive composition comprising:
(a) a sulfurized fatty acid,
(b) a hindered amine being one or more chosen from the group consisting of:
(1) a compound of the formula
where R 26 is H, O or a hydrocarbon from 1 to 25 carbon atoms, an alkoxy radical with the oxygen bound to the nitrogen with the alkyl portion containing 1 to 25 carbon atoms, or a COR group, the R being a hydrocarbon containing from 1 to 25 carbon atoms; R 27 , R 28 , R 32 , R 33 are hydrocarbons with 1 to 25 carbon atoms; R 29 , R 31 are H or hydrocarbons with 1 to 25 carbon atoms; when n=1, R 30 is OH, H, O, NH 2 , NR 2 where R is a hydrocarbon with 1 to 25 carbon atoms, an ester group O 2 CR where R is a hydrocarbon with 1 to 25 carbon atoms, or a succinimide group; when n=2, R 30 is the diacyl radical of an aliphatic dicarboxylic acid having 4 to 12 carbon atoms;
(2) 4-stearoyloxy-2,2,6,6-tetramethylpiperidine,
(3) di(2,2,6,6-tetramethylpiperidin-4-yl) sebacate,
(4) di(1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate,
(5) bis (1-octyloxy-2,2,6,-tetramethyl-4-piperidyl) sebacate
(6) polymer-bound piperidine compound,
(7) a compound of the group consisting of 2,2,6,6-tetramethylpiperidines, 1,2,2,6,6-pentamethylpiperidines, 1-oxo-2,2,6,6-tetramethylpiperidines, and 1-alkoxy-2,2,6,6-tetramethylpiperidines, and
(8) a compound of the group consisting of di(1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, di(,2,2,6,6-tetramethylpiperidin-4-yl) sebacate and bis (1-octyloxy-2,2,6,-tetramethyl-4-piperidyl) sebacate, and
(c) a diaryl amine