CA1138472A - ANTIOXIDANT FOR POLYESTER FLUIDS .alpha. - METHYL - N PHENYLBENZENEMETHANAMINE - Google Patents

Abstract

ABSTRACT OF DISCLOSURE
An antioxidant for lubricating oils comprising an amine compound selected from substituted benzylamines or a substituted 1-amino-1,2,3,4-tetrahydro-naphthalene. The preferred anti-oxidants are N-( alpha -methyl -p-octylbenzyl) aniline, N-(alpha-methylbenzyl)- p -nonylaniline or 1-( p -dodecylanillno)-1,2,3,4-tetrahydronaphthalene.

Description

3~ 2 ANTIOXIDANT FOR POLYESI'ER FLUIDS - A - METHYL - N
PHENYLBENZENEMETHANAMINE
BACKGROUND OF THE INVENTION
Advanced automotive, aircraft and other industrial equip-5 ment require lubricating oils that are effective at elevated tempera-tures. Polyesters, polyolefins, polyglycols, polyphenyl ethers, phosphates, silicones, etc. have been used as suitable lubricating oils. These lubricating oils undergo oxidative degradation at eleva-ted temperatures. Loss of lubricating properties due to oxidative 10 breakdown of these oils may cause failure of a part, or parts, in contact with the oils. The prior art discloses the stabilization of lubricating oils using various amines including diphenyl- and substi-tuted diphenylamines, p-phenylenediamine and substituted naphthy-lamine. There appears to be no recognition of the use of secondary 15 amines wherein one of the groups attached the amino nitrogen is an aromatic or substituted aromatic ring and the other group is an aliphatic carbon which in turn is attached to an aromatic or substi-tuted aromatic ring.
U.S. Patent 1,469,245 discloses N-( o -Hydroxybenzyl) 20 -N'-phenyl-p-phenylene diamine as an anti-degradant for rubber.
This compound belongs to the class of phenylene diamines which are known antioxidants. Furthermore, its use as a stabili2er for lubri-cating oils is neither disclosed in that patent, nor elsewhere.
U.S. Patent No. 2,108,147 teaches a method for preparing 25 secondary and teritary amines including 1-anilino-1-phenylethane.
Hickenbottom teaches a phenylamine compound designated as alpha-phenylethyl- ~-toluidine; see Journal of the Chemical SocietY
(1934) pages 319-322. Beilstein discloses a phenyl amine compound of the general formula ~3 H - C - NH - R
CH2Br wherein R can be phenyl; see Handbuch Der Organishen Chemie 4th Ed., Vol XII Pat. IV pages 2403-4. None of the aforegoing com-35 pounds are taught to be antioxidants.

~ 3~ 72 SU~UARY OF THE INVENTION
It has surprisingly been found that certain amino com-pounds are effective as antioxidants. These amino compounds have the general formula H
(I) Y 1~
\
Rl wherein Y is:

10 (Il) ~C--; or When Y is the moiety of formula (II), Z is H or C1 to C3 alkyl; and X and R2 are each independently selected from the group consisting of hydrogen, C1-C12 alkyl, C1-C12 alkoxy; C2-C18 carbalkoxy, halogen, or nitro and R1 is hydrogen, C1-C12 alkyl, C1-C12 alk-20 oxy, C2-C18 carbalkoxy, halogen, amino or nitro. When Y is the moiety of formula (III), Rl and R3 are each independently selected from the group of moieties set forth as R1 above and R2 is as ` previously deffned.
; The compounds of this invention are novel compounds `` 25 when X and Z are each independently selected from the group H
and C1-C3 alkyl; and Rl and R2 are as previously defined except that they may not simultaneously be hydrogen when Z is hydrogen.
In its preferred embodiment the antioxidants of this invention are used in conjunction with a metal deactivator and a metal or metal salt. The preferred metal salts are oil soluble organ-ic salts, e.g., metal naphthenates.

~3~t47~
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to a compound for the stabilizing lubricating oils against oxidation and sludge formation. In particular this invention relates to stabilizing such oils utilizing 5 phenylated benzylamines or phenylated tetrahydro naphthylamines, which may be substituted or unsubstituted, either alone or in conjunction with a metal deactivator and a metal compound. This stabilizer system provides a surprisingly high degree of resistance to oxidative breakdown of lubricating oils as well as resulting in 10 dramatic reductions in sludge formation. Certain of the phenylated benzylamines and phenylated tetrahydro naphthylamines used in the practice of this invention are novel compounds.
This invention relates to stabilizing a lubricating oil utilizing as the stabilizer an antioxidant which is an amino compound 15 having the general formula (I) y_N~ ~ R
wherein Y is:

(II) ~C--;or

2 5 R2 When Y is the moiety of formula (II), 2 and X are each indepen-30 dently selected from the group consisting of H or C1 to C3 alkyl;
R2 is selected from the group consisting of hydrogen, C-1 to C12 alkyl, C1-C12 alkoxy; C2-C18 carbalkoxy, halogen, or nitro and R1 ~3~72 y g , C1 C12 alkyl, C1-C12 alkoxy ~ C2-C18 carbalkoXY
halogen, amino or nitro. When Y is the moiety of formula (III), R1 and R3 are each independently selected from the group of moieties set forth as R1 above and R2 is as previously defined.
The compounds of this invention are novel compounds when X and Z are each independently selected from the group consisting of H and C1-C3 alkyl; and R1 and R2 are as previously defined except that they may not be simultaneously hydrogen when Z is hydrogen. In its preferred embodiment Z is H or methyl and X is methyl.
Illustrative non-limiting examples of the novel antioxidants of this invention are N-( alpha-methyl- _-octylbenzyl)aniline;
N-( alpha-methyl-p-nonylbenzyl)aniline;
15 N-( alpha-methyl benzyl)- _ -nonylaniline;
N-( alpha-methyl benzyl)- ~ -dodecylaniline;
N-( _~-methyl benzyl)- ~ -methoxyaniline;
N-( alpha-methyl benzyl)- _ -methoxyaniline;
N-( alpha-methyl benzyl)- o -methoxyaniline;
20 N-( alpha-methyl benzyl)- _ -carbethoxyaniline;
N-( alpha-methyl benzyl)- o -carbethoxyaniline;
N-~ alpha-methyl benzyl)- E~-chloroaniline;
N-( alpha-methyl benzyl)- m -chloroaniline;
N-( alpha-methyl benzyl)- o -chloroaniline;
25 N-(alpha, alpha-dimethylbenzyl)aniline 1- ( _-dodecylanilino)-1, 2, 3, 4-tetrahydronaphthalene;
1-( ~-carbethoxyanilino)-1,2,3,4-tetrahydronaphthalene;
N-( ~-acetyl- alpha -methyl benzyl)aniline; and 1, 4-bis- (1 -anilinoethyl )benzene .
30 The preferred antioxidants of this invention are N-( alpha -methyl- ~ -octylbenzyl)aniline and N-( alpha -methyl benzyl)- p -nonylaniline.
Addition of the amines described above to lubricating oils - imparts an unexpectedly high degree of resistance to oxidative 35 breakdown.
The amines of this invention are useful in stabilizing a wide range of lubricating oils including polyester oils, mineral oils ~L~3~
and synthetic hydrocarbon oils. The stabilizer system of this invention is particularly effective for use in polyolester lubric~ting oils .
The polyolester lubricating oils for which the stabilizer 5 systems of this invention are suitable are synthetic lubricants based upon one or more organic carboxylic acid esters. Illustrative examples of such oils are diesters such as dioctyl sebacate or ' dinonyl adipate prepared by the reaction of a dibasic acid and a monohydric alcohol; triesters such as trimethylolprnpane tripelor-gonate or trimethylolpropane tricaprilate prepared by the reaction of trimethylol propane and a monobasic acid; tetraesters such as pentaerythritol tetracaprilate prepared by the reaction of penta-erythritol and a monobasic acid; esters of trimethylolpropane or pentaerythritol prepared by reaction with mixtures of monobasic acids; or complex esters prepared by reacting mixtures of mono-basic acids, dibasic acids and polyhydric alcohols.
The synthetic hydrocarbon oils to which the stabilizer system of this system of this invention may be added are oligomers of alpha olefins. The preferred alpha olefins are C3 -C14 alpha-olefins. Normally, these hydrocarbon oils have a number average molecular weight of about 280 to about 2,000; preferably about 350 to about 1, 500 . These lubricating oils have low unsaturation preferably having an iodine number of less than 3.
The term "antioxidant" when used in the specification and claims means the substituted phenylated amines and substituted tetrahydronaphthylamines of this invention. The term "stabilizer system" as used in the specification and claims means the aforegoing antioxidants in conjunction with a metal compound and a metal deactivator.
The metal may be present either as the free metal or a salt of a metal. The salt must be soluble in the lubricating oil and is preferably an organometallic salt.
The preferred salts include naphthenates, stearates, acetylacetonates, octoates, decanoates etc.
The metal deactivators useful in the practice of this invention are benzotriazole and benzotriazole derivatives. The benzotriazole derivative can be alkyl substituted or dialkyl amino ~13t~9t7Z

alkyl substituted; preferably dialkyl amino alkyl substituted.
Substitution is on the secondary nitrogen of the triangle. The alkyl group can be a C1 to C20 alkyl and each alkyl may be the same or different than the others. Preferably the alkyl groups are 5 selected to give the benzotriazole derivative sufficient oil solubility to be incorporated into the lubricant in an effective amount e . g .
C6-C12 alkyl. Typical of such compounds is Reomet*38 marketed by Ciba Geigy Co. The term "metal deactivator" as used in the speci-fication and claims means a compound-which when added to a lubri-10 cant will neutralize the catalytic effect of metals e . g, copper inpromoting oxidation.
The various components of the antioxidant system which may be added in any order are used in the following amounts. The antioxidant of this invention is used in amounts varying from about 0.5 to about 5.0 parts by weight per 100 parts of the oil, prefer-ably, about 1. 0 to about 4 . O parts; more preferably 2 . O to 2.5 parts. The metal deactivators can be used in amounts of aoout 0.05 to about 1.0 part by weight per 100 parts of the oil, preferably, 0.1 to 0. 3 part. Metal or metal salts are used in the amounts of about 1 to about 25 parts of metal by weight per million parts of the oil; preferably 2 to 10 parts. The preferred metal is copper.
The criteria used herein to evaluate the effectiveness of an anffoxidant for lubricating oils are:
1) the amount of sludge producéd, 2) the change in initial viscosity,

3) the change in neutralization number; and,

4) the weight change of the test metals.
These criteria are determined after the oil containing the antioxidant system of this invention has been aged for 72 hours at 370F or after the oil containing the antioxidant system has been aged for 48 hours at 425F.
The benefits of the antioxidants and stabilizers of this invention may be more readily appreciated by reference to the following examples. The term "polyolester" as used in the specifi-cation and claims means a polyester prepared from a polyol by reacting the polyol with a stochiometric equivalent of mono basic acids .
* Trade mark This example shows the unexpected ability of the anti-oxidant of the presen t invention to protect polyester based lubri-cating oils against oxidative degradation. The oil used was a commercially available polyolester fluid, Hercolube A (marketed by Hercules Inc.) and believed to be one prepared from pentaerythritol and a mixture of monocarboxylic acids, e . g ., valeric acid and pelargonic acid.
Experiments were carried out in order to evaluate the effectiveness of the antioxidant. The oil sample used in runs B
and C was prepared by adding N-( alPha-methylbenzyl) aniline in the amount set forth in Table I to 100 grams of the polyolester based oil. Sample D was similarly prepared containing phenyl alpha-naphthylamine, a commercially available stabilizer. The amounts used in each case are set forth in Table 1.
Each of the samples was tested according to the following test procedures:
A 100 ml. sample having the compositions set forth in Table I is poured into a pyrex glass test cell and aged by inserting one end of a glass air delivery tube into the test cell while the remaining 25 ml. portions of each original oil sample is set aside and analyzed for neutrali-zation number and Kinematic Viscosity in centistokes at 100F. Around this glass air delivery tube immersed in the oil was placed from zero to four metal washers (Mg, Cu, Ag, and Fe) as identified in Table I. When more than one washer was used, they were separated from each other by glass spacers. These remained in the oil during the aging process and served to indicate the extent of corrosion of the oil oxidative decomposition products on the metal. The test cell was then fitted with a reflux condenser. The assembly was placed in a constant temperature aluminum block. An air hose was then attached to the other end of the air delivery tube and the air flow was adjusted so that five liters of air per hour was bubbled through the oil. This aging test was carried out for 48 hours at 425F. After aging, the * Trade mark '~

oil was fillered hot and tlhe amount of sludge developed was collected and was determined and recorded in milli-grams per 100 ml. of the oil. The filtered oil was then analyzed to determine changes in neutralization number

- 5 and Kinematic Viscosity at 100F.
The neutralization number was determined by the color-indicator titration method according to ASTM Procedure D97~-55T.
The Kinematic Viscosity was determined according to ASTM Procedure D445-53T.
The metal washers, which were weighed initially, were then carefully washed and weighed again to determine the weight change in grams.
The data in Table I dramatically show that when an amine such as N-( ~-methybenzyl) aniline is added to a polyolester based lubricating oil the aged properties of oil Samples B and C are excellent as noted by very little change in the viscosity or neutrali-zation number, very low sludge and essentially no weight change in the metals. The amine antioxidant clearly provides better all around protection than a commercially available stabilizer (Sample D).
It should be noted that Sample C, wherein the test was conducted in the presence of copper, was slightly more deteriorated , than Sample B, where no copper was present.
TABLE I

RUN# OIL SYSTEM STABILIZER % VloO N.N.3 (in mg.) A 100 - --- 94.9 26.2 Undetermined B 100 5 2.013.68 2.7 5.1 C 100 5 2.018.81 2.64 19.7 D 100 6 2.0 31.5 2.2 135.7 TABLE I (con't.) 1 WEIGHT CHANGE (in grams) OF WASHERS
R~N# OIL Mg Fe Cu Ag A 100 -0.1366 -0.0052 -0.0091 -0.0001 B 100 -0.0001 ~0.0003 * -0.0017 C 100 +0.0001 -0.0004 -0.0011 -0.0001 TABLE I (con't.) 1 WEIGHT CHANGE (in grams) OF WASHERS
RUN# OIL Mg Fe Cu Ag D 100 -0.0130 0.0000 -0.0024 -0.0001 * no metal included LEGEND: 1. Oil --- Commercially available, Hercolube A.
2. % / V10O --- Percent change in viscosity at 100F.
3. N.N. ---Neutralization Number of aged oil.
4. Aged oil was so viscous that it could not be com-pletely filtered to determine the amount of sludge formed. Neutralization number and viscosity of the aged oil are actually the properties of a small sample that could be filtered.
5. N-( alpha-methylbenzyl)aniline

6. Phenyl- ~e~ -naphthylamine EXAMPLE II
This example demonstrates the effect of the addition of and changes in the levels of a metal deactivator such as Reomet-38, a benzotriazole derivative marketed by Ciba Geigy Co., on the 20 stabilization of a polyolester based lubricating oil while the level of N- ( _~-methylbenzyl)aniline and copper are maintained constant .
The samples were prepared as in EXAMPLE I.
The data in Table II shows that the addition of Reomet-38 at the levels tested is effective in controlling viscosity change, 25 neutralization number change and sludge formation. The data further demonstrates that the addition of Reomet-38 dramatically controls the weight loss of the copper washer.
The data in Table II also shows that the addition of even low levels of the metal deactivator (samples B and C) provide better 30 protection than when no deactivator is used (sample A).

TA LE II

SAMPLE1 _ (grams) (&rams) _' 100 N.N. (mg) A 2.0 0.00 lB.812.64 19.7 B 2,0 0.07 12.041.65 5.2 C 2.0 0.08 6.99 1.66 6.5 D 2.0 0.3~ 7.61 1.60 6.7 E 2.0 0.50 18.424.20 9.2 TABLE II (Con't.?
1 WEIGHT CHANGE (in grams) OF WASHERS
SAMPLE Mg Fe Cu Ag A +0.0001 +0.0004 -0.0011+0.0001 B +0.0001 0.0000 -0.00040.0000 C 0.0000 0.0000 -0.0003-0.0004 D 0.0000 +0.0003 -0.0001-0.0002 E -0.0001 +0.0002 +0.0003+0.0004 NOTES: 1. 100 ml. of Hercolube A is used.
2. Antioxidant N-( alpha-methylbenzyl)aniline 3. R-38: Reomet-38 is used as metal deactivator (a commercially available material from Ciba-Geigy Chemical Co.) EXAMPLE III
This example dramatically demonstrates that Reomet-38 cannot be included in the stabilizing system without incorp~orating copper either in the form of a soluble salt or in the form of a metal strip, washer, wire, etc. This example further shows how changes in the level of copper while maintaining constant N-( alpha-methyl-benzyl)aniline and Reomet-38 levels effects stabilization. The samples were prepared as in EXAMPLE I.

7~
The data in Table III shows that a stabilizer system containing N-( alpha-methylbenzyl)aniline and Reomet-38 is inef-fective in the absence of copper (Sample A, Table III) in decreas-ing the amounts of sludge, maintaining low viscosity, low neutral-5 ization number, and protecting the metal washers from oxidation.
In the absence of copper, Reomet 38 functions as a pro-degradant.
The data in Table III further shows that increasing amounts of copper above 10 ppm causes the stabilizer system to exhibit a decrease in its efficiency in controlling oxidative breakdown.

TABLE III

ANTIOXIDANT2 R-383 4%~ V SLUDGE
SAMPLEl(grams) (grams) Cu 100 N.N. (mg) A 2.0 0.3 - 32.05 5.6560.7 B 2.0 0.2Washer 15.66 1.585.7 C 2.0 0.2 lppm 12.64 0.5319.3 D 2.0 0.2lOppm 9.14 1.640.9 E 2.0 0.230ppm 23.15 1.798.5 F 2.0 0.3Washer 7.61 1.66.7 G 2.0 0.330ppm 15.33 1.59173.3 H 2.0 0.3200ppm 20.8 7.61582.2 TABLE III (Cont.) 1 WEIGHT CHANGE (in grams) OF WASHERS
SAMPLE Mg Fe Cu Ag A -0.0594 +0.0007 -0.0001 B +0.0001 +0.0001-0.0001 -0.0003 C +0.0003 +0.0001 +0.0001 D +0.0003 +0.0001 -0.0001 E -0.0002 +0.0002 -0.0001 F 0.0000 +0.0003-0.0001 -0.0002 G -0.0116 +0.0001-0.0003 -0.0002 H +0.0373 +0.0001-0.0015 -0.0003 NOTES: 1. 100 m]. of }lercolube A is used.
2. Antioxidant N-( ~ a-methylbenzyl)aniline.
3. R-38: Reomet-38 is used as metal deactivator.
4. Cu: Copper is added as copper naphthenate.
EXAMPI E IV
This example utilizes data presented in Examples 1, II and III to demonstrate the essence of the instant invention. See Table IV .
Clearly Sample II-D illustrates that when the amine, a metal deactivator and copper are present, the greatest protection i5 afforded to the oil. Sample I-B (amine but no copper), Sample I-C
(amine and copper) and most dramatically Sample III-A (amine and metal deactivator but no copper) all show decreased protection when compared with II-D where all three components of the instant inven-tion are present in the system.
- TABLE IV

ANTIOXIDANT2 R-383 %~ V SL~DGE
SAMPLEl (grams) (grams) 100 N.N. (mg) A (Table I) --- - 94.9~* 26.2 *
B (Table I)2.0 - 13.68 2.7 5.1 C (Table I)2.0 _ 18.81 2.64 19.7 D (Table II) 2.0 0.3 7.61 1.6 6.7 A (Table III) 2.0 0.3 32.05 5.6 560.7 WEIGHT CHANGE (in grams) OF WASHERS
25 SAMILEl Mg Fe Cu Ag A (Table I) -0.1366 -0.0052 -0.0091 -O.OOO1 B (Table I) -0.0001 +0.0003 * -0.0017 C (Table I) +0.0001 +0.0004 -0.0011 +0.0001 D (Table II) O.0000 +0.0003 -0.0001 -0.0002 A (Table III) -0.0594 +0.0007 ~ -0.0001 NOTES: 1. 100 ml of }lercolube A is used.
2. Antioxidant N~ ha-methylbenzyl)aniline.
3. R-38: Reomet-38 is used as metal deactivator. (a commerically available material from Ciba-Geigy Chemical Co.) '~ No metal included *~~ Aged oil was so viscous that it could not be com-pletely filtered to determine the amount of sludge formed. Neutralization number and viscosity of the aged oil is actually the properties of a small sample that could be filtered.
EXAMPLE V
This example demonstrates how the stabilization of a polyolester based lubricating oil is affected by changes in the level of N-( ~-methylbenzyl)aniline while maintaining constant Reomet-38 level in the presence of a constant amount of copper metal. The samples were prepared as in EXAMPLE I, using the amounts of ingredients as shown in Table V.
The data in Table V show that when a level of about 2.0 to 3.0 parts of N-( ~-methylbenzyl)aniline was used together with 0 . 2 part of Reomet-38, a polyolester based lubricating oil is effectively stabilized. The preferred level of N-( alpha-methylben-zyl)aniline is shown to be from 2.0 to 2.5 parts.
It can be seen from the results of Table V that the level of the N-( alpha-methylbenzyl)aniline is critical in producing poly-olester based lubricating oils having outstanding aged physical properties while maintaining Reomet-38 at a constant level.
TABLE V

30 SAMPLE OILl (grams)(grams) %~VloO N.N.(mg) A 100 1.5 0.2 23.91 5.4 694.8 B 100 2.0 0.2 17.13 1.4 10.9 C 100 2.2 0.2 14.03 1.1 9.5 ~ABLE V~Con't.) AN~'IOXIDANT2 R-3~3 0 SLUDGE
SAMPLE OILl (gram~) (grams) ~V100 N.N. (mg) D lOO 2.5 0.2 18.62 l.llO.O
5E l00 3.0 0.2 9.64 1.130.9 TABLE V (Cont.) WEIGH~ CHANGE (in grams) OF WASHERS
SAMPLE OIL _ ~___ Fe Cu Ag A l00 -0,0521 +0.0002+0.0~02 +0.0001 lO B lOO 0.0000 0.0000+O.OOOl -0.0001 C 100 -0.000l 0.0000+0.0002 +0.000l D 100 +0.000l +0.0002+0.0002 0.0000 E 100 -0.0026 +0.0002+0.0001 +0.0002 NOTES: l. Oil - Commerically available, p~lyolester based lubricating oil, Hercolube A.
2. N-( alpha-methylbenzyl)aniline.
EXAMPLE VI
This example demonstrates how various substituted N-benzylanilines effect the stabilization of a polyolester based oil while 20 maintaining a constant Reomet-38 level in the presence of a constant amount of copper metal.
Substituted N-benzylanilines were prepared by catalytic hydrogenation of the corresponding Schiff's bases. Five percent Pd/c was used as the catalyst and ethanol was used as the solvent 25 for hydrogenating the Schiff's bases. Schiff's bases, in turn, were prepared by the reaction of the appropriate ketones and anilines in the presence of molecular seives. About 40 grams of molecular sieves (Linde 5A) were added to 1.0 mole of ketone and 1.0 to 1.2 moles of aromatic amine in 200 ml. of benzene; see Kazuo Taguchi 30 and F. H. Westheimer, J. ORG. CHEM. 36, 1570 (1971). The reaction mixture was refluxed with continuous removal of water until almost no free ketone could be detected in the reaction mixture by I. R. spectroscopy. The mixture was then filtered and the molecu-lar seives washed with benzene. The filtrate and washings were combined and evaporated to dryness under reduced pressure. The crude product was purified by either crystallization or by vacuum distillation .
The samples were prepared and tested as in EXAMPLE I
using the amounts of ingredients as shown in Table VI.
The data in Table Vl clearly show that substituted benzylanilines of this invention stabilize polyolester based lubricat-ing oils with respect to oxidative breakdown.
Substitution on the aromatic ring of the benzyl group seems to have little adverse effect.

TABLE VI
EFFECT OF SUBSTITUENTS IN N-BENZYLANILINES

~ CH - NH ~

Run R-38 AGED 0~SLUD OE
No- R2 _ Rl X (grams) N.N. ~ Vlo0 mg/lOOml 1 H ~-C00C2H5 CH30.21.6 37.96 1,096.4 2 H m-COOC2H5 CH30.26.03 40.17 1,625.0 3 H ~-OCH3 CH3 0.25.432.221,294.1 4 H m-OCH3 CH3 0.22.241.84 25.2 5 H o-OCH3 CH3 0.27.539.09 146.2 H ~ C12H25 CH30.210.0 370.61 32.0 7 H ~-Cl CH30.24.3 33.49 33.1

8 H _-Cl CH30.27.7 25.81 568.3

9 H o-Cl CH3 0.29.829.30 606.9 ~-CH H CH30.2 1.1 11.24 6.6 ~CH H CH3 0.23.729.50 13.9 12 H H CH30.2 1.0 17.13 6.9 L~7~2 Run R-38 AGED SLUDGE
- No. R RX (~rams) N.N. %~Vlo0 mg/lOOml 13 H HCH2CH2CH3 0.2 7.3 25.31 606.0 14 26.2 94.97 COULD NOT
BE FILTERED
H ~ CC12H25 CH3 0.2 2.7 36.11 2.8 TABLE VI (Cont.) RunWEIGHT CHANGE (in grams) OF WASHERS
No. M~ Fe Cu Ag Remarks 1 -0.0634 -0.0002 -0.0018 0.0000 B
2 -0.0683 -0.0002 -0.0014 -0.0003 B
3 -0.0523 0.0000 -0.0001 0.0000 B
4 -0.0455 0.0000 -0.0036 -0.0002 B
5 -0.0500 +0.0010 -0.0036 -0.0002 B
6 -0.0877 +0.0001 -0.0002 0.0000 C
7 -0.0419 +0.0001 -0.0048 -0.0051 B
8 -0.0203 0.0000 -0.0040 -0.0008 B
9 -0.0163 -0.0012 -0.0077 -0.0017 B

- 10 -0.0001 -0.0030 -0.0002 -0.0001 B

11 -0.0001 -0.0004 -0.0002 -0.0004 B

12 -0.0001 -0.0002 -0.0001 -0.0001 B

13 -0.0620 -0.0002 -0.0002 -0.0001 B

14 -0.1366 -0.0052 -0.0091 -0.0001 A

15 0.0000 -0.0001 -0.0007 -0.0002 D
NOTES: A. No antioxidant is used. In other experiments, with the exception of Run 14, 2.0 g of substituted N-ben-zylaniline is used.

B. Hercolube A (100 ml) is used for each test.
C. Herc~lube A (50 ml) is used for this test.
D. 3.5 g of the antioxidant is used.
EXAMPLE VII

A preferred embodiment of this invention involves alkyla-tion in the benzyl ring and/or the aniline ring of the parent ~-methyl benzyl aniline. This is beneficial in that it results in de-creased volatility of the parent compound. Thus, such compounds as ~ CH--NH~3 ~/ \~
R2/ CH3 \ R1 where R2 can be H, or a C1 to C12 alkyl group and Rl can be H
15 or a C4 to C12 alkyl group; provided that R1 and R2 are not simultaneously both hydrogen. R2 can be a Cl to C12 alkyl group which may or may not be branched. Rl can be an alkyl group, preferably in the E~-position or a tertiary alkyl group such as those derived from isobutylene, isobutylene dimer, isobutylene 20 trimer, propylene trimer, alpha-methyl styrene and the like.

TABLE VII

SAMPLEl(grams) (grams) L~ V100 N N. (mg) A 2.5 0.2 20.8 3.5 16.7 B 3.0 0.2 25.2 2.6 13.9 C 3.5 0.2 16.4 1.5 5.7 TABLE VII (Con't.) WEIGHT CHANGE (in grams) OF WASHERS
SAMPLElMg Fe Cu Ag A +0.0001+0.0002 -0.0006 0.0000 B +0.0001~0.0002 -0.0004 -0.0001 C 0.0000 +0.0002 0.00000.0000 NOTES: 1. 100 ml. of Hercolube A is used.
2. Antioxidant N-( ~ha-methyl- ~-octyl) benzylaniline.
3. R-38: Reomet-38 is used as metal deactivator.
EXAMPLE VIII
This example shows how phenylated- alpha-tetralylamine affects the stabilization of a polyolester based lubricating oil.
The phenylated- alpha-tetralylamines were prepared according to the procedure described in EXAMPLE VI.
The samples were prepared as in Example I using the 10 amounts of ingredients as shown in Table VIII.
The data in Table VIII shows that the addition of phenyl-ated- ~-tetralylamine, a metal deactivator and copper or a copper salt to a polyolester lubricating oil such as Hercolube A
stabilizes the said oil against oxidative breakdown.

TABLE VIII

HN

CHANGE
Run R-38 A.O. in VS~UDGE
20 No. R (grams) (grams) OIL N.N. % ~ 100 (in mg) 1 H 0.2 2.5 100 5.3 24.5134.3 2 H 0.5 2.0 100 3.7 32.3149.7 3 H 0.2 2.0 100 3.7 27.7029.6 4 H 0.5 1.5 100 12.1 40.3836.6 H 0.5 1.0 100 10.4 39.5738.9 6 H 0.5 3.0 100 3.2 33.23275.9 7 p C12H25 0.5 1.0 100 6.265.50 1,964.2 CHANGE
Run R-38 A.O. in SLUDGE
No. R ~ ms) (grams) OIL_ N.N. % Q 100 (in mg) 8 P-Cl2H25 0.5 2.0 100 8.4 44.8821.9 P 12 25 0 5 3.5 100 5.4 30.0614.9 p-OC}l3 0.5 0.9 10013.0 29.755,504.2 11 p-COOC2H5 0.5 2.0 100 4.4 28.42 7.0 12 - O 3 10016.7 39.57 ~

TABLE VIII (Cont.) 10 Run WEIGHT CHANGE (in grams) OF WASHERS
No. Mg Fe Cu Ag 1 0.0000 +0.0001 +0.0002 +0.0001 2 +0.0003 +0.0004 +0.0003 +0.0001 3 +0 00~3 +0 0004 +0 0004 +0.0002 4 +0.0002 +0.0006 +0.0001 +0.0002 +0.0002 +0.0005 0.0000 +0.0002 6 +0.0008 +0.0012 +0.0030 +0.0005 7 -~.9870 +0.0002 +0.0001 +0.0002 8 +0.0002 +0.0002 +0.0002 -0.0003 9 +0.0003 +0.0003 +0.0006 +0.0004 -0.0017 -0.0017 -0.0002 +0.0004 11 +0.0001 +0.0001 +0.0001 +0.0001 12 -0.1000 -0.0020 -0.0495 -0.0001 NOTE: ~ Too viscous to filter. N.N. and viscosity were taken on a few milliliters.

7~
EXAMPI.E IX
To 100 parts of polydecene synthetic hydrocarbon oil is added2.0 parts of 1-(p-dodecylanilino)-1,2,3,4-tetrahydro-naphthalene and 0.5 par-t ~eomet 3a. Oxidative testing of the oil as described in Example II-E show that the above combination effectively protects syn-thetic hydrocarbon oils against oxidative breakdown .
EXAMPLE X
To 100 parts of mineral oil is added 2 . 0 parts of N - ~
alpha-methylbenzyl)-aniline and 0 . 5 parts Reome-t 38 as in Examplè
II.E. The resulting blend is found also to exhibit excellent antiox-idant properties when an aging test is performed at elevated temperatures .
EXAMPLE XI
To 100 parts of polyoctene synthetic hydrocarbon oil is added 2.0 parts of N-( alpha-methylbenzyl)aniline and 0.5 parts Reomet 38 as in Example II . E . The resulting blend is found to exhibit excellent antioxidant properties when an aging test is per-formed at elevated temperatures.
EXAMPLE XII
To 100 parts of polydecene synthetic hydrocarbon oil is added 2.0 parts of N-( alpha-methylbenzyl)aniline and 0.5 parts Reomet 38 as in Example II.E. The resulting blend exhibits excel-lent antioxidant properties when aging is performed at elevated temperatures.
EXAMPLE XIII
To 100 parts of a blend of 25 parts polyoctene and 75 parts trimethylol propane triheptanoate synthetic ester fluid is added 2.0 parts of N-( alpha-methylbenzyl) aniline and 0.5 parts Reomet 38 as in Example II . E . The resulting blend possesses excellent antioxidant properties when aging is performed at elevated temperatures .
EXAMPLE XIV
To 100 parts of a blend of 50 parts of polyoctene and trimethylol propane triheptanoate synthetic ester fluid is added 2.0 parts of N-( alpha-methylbenzyl)aniline and 0.5 parts Reomet 38 as in Example II.E. The resulting blend is found to exhibit excellent antioxidant properties when aging is performed at elevated tempera-tures .
EXAMPLE XV
A. A solution of p-nonyl acetophenone (9Og), aniline (75g), Toluene (125ml) and pyridine (20ml) was refluxed with continuous removal of water. N-~-methyl-p-nonyl benzylidene) aniline (XXX) was obtained by fractional distillation. XXX had a boiling point of 200-208" at 0.075 millimeter.
Analysis calculated for C23H31N: C, 85.92; H, 9-72; N, 4.36. Found: C, 87.12; H, 10.07; N, 3.91.
B. N-alpha-methyl-p-nonyl benzylidene) aniline (XXX) (40g) prepared by the procedure described in Example XVI A was hydrogenated using 5% Pd/C as the catalyst and 95% ethanol as the solvent. N-(alpha-methyl-p-nonyl benzyl) aniline (XXXI) was obtained by fractional distillation. XXXI had a boiling point of 183C at 0.15 millimeter.
EXAMPLE XVI
A solution of alpha, alpha-dimethyl benzyl alcohol (73g), aniline (lSOg), toluene (150ml) and p-toluene sulfonic acid (2.0g) was refluxed with continuous removal of water . N - (alpha, alpha, dimethyl benzyl) aniline (XXXII) was obtained by fractional distillation. XXXII had a boiling point of 121C at 0.07 millimeter.
Analysis calculated for C15H17N: C, 85.26; H, 8.11; N, 6.63. Found: C, 85.08; H, 7.97; N, 7.03.
EXAMPLE XVII
A. A solution of p-octylacetophenone (lOOg), aniline (85ml), pyridine (20ml) and toluene (200ml) was refluxed with the continuous removal of water. The product was a mixture of unreacted p-octyl acetophenone, aniline, pyridine and the Schiff's base. The desired N-(o~-methyl-p-octyl-benzylidene) aniline (I) (65g) was separated from other components of the reaction mixture by fractional distillation . The desired product (I ) had a boiling point of 192C at 0.1 millimeter.
B. N-(-methyl-p-octyl benzylidene) aniline (49g), prepared by the procedure described in Example IA was hydrogen-ated using 5% Pd/C as the catalyst and 95% ethanol as the solvent.
N-(o~methyl-p-octyl-benzyl)aniline (II) (40.5g) was obtained by fractional distillation. The desirecl product II had a boiling point of 173 to 178C at 0.025 mlllimeter.
Analysis calculated for C22H31N: C, 85.43; H, 10.03; N, 4.53. Found: C, 86.46; H, 10.58; N, 4.54.
EXAMPLE XVIII
A. Nonyl benzene was prepared by alkylating benzene with mixed propylene trimer using Friedel Crafts reaction. Nonyl benzene was nitra-ted and reduced to give p-nonyl aniline. A
solution of p-nonyl aniline (30g), acetophenone (60g), toluene (200ml) and pyridine (20ml) was refluxed with continuous removal pf water. N~ -methyl benzylidene)-p-nonyl aniline (III) was obtained by fractional distillation. III had a boiling point of 194C
at 0.05 millimeter.
B. N-(o~-methyl benzylidene)-p-nonyl aniline (III) (16.5g) prepared by the procedure described in Example IIA was hydrogenated suing 5% Pd/C as the catalyst and 95% ethanol as the solvent. N-(o~-methyl benzyl)-p-nonyl aniline (IV) was obtained by fractional distillation. IV had a boiling point of 180-184C at 0.025 millimeter .
EXAMPLE XIX
A . solution of acetophenone (33.5g), p-dodecyl aniline (73g), benzene (50ml) was refluxed in the presence of molecular sieve (lOOg) with continuous removal of water. The crude product was purified by crystallizing it from ethanol to give N- (-methyl benzylidene)-p-dodecyl aniline (V) (95g). V had a melting point of 47C .
Analysis calculated for C26H37N: C, 85.89; H, 10.26; N, 3.85. Found: C, 85.96; H, 10.55; N, 4.13.
B. N-(o~-methyl benzylidene)-p-dodecyl aniline (80g) prepared by the procedure described in Example IIIA was hydro-genated using 5% Pd/C as the catalyst and 95% ethanol as the solvent to give N-(oc-methyl benzyl)-p-dodecyl aniline (VI). VI had a boiling point of 188C at 0.03 millimeter.
Analysis calculated for C26H39N: C, 85.42; H, 10.75; N, 3.83. Found: C, 85.49; H, 10.54; N, 4.01.

~, 3~

_XAMPLE XXI
A. A solution of acetophenone (64ml), p-anisidine (65mg), }~enzene (lOOml) was refluxed in the presence of molecular sieve (lOOg) with continuous removal of water. The crude product 5 was purified by crystallizing it from ethanol to give N- (acmethyl-benzylidene)-p-anisidine (VII) (50g). VII had a melting point of 81-82~C .
Analysis calculated for C15H15NO: C, 79-97; H, 6-71; N, 6.22. Found: C, 80.10; H, 6.78; N, 6.24.
B. N-(Q(-methyl benzylidene)-p-anisidine (VII) prepared by the procedure described in example IVA was hydrogenated using 5% Pd/C as the catalyst and 95% ethanol as the solvent to give N-(o~-methyl benzyl)-p-anisidine (VIII). VIII had a melting point of 64C ~
Analysis calculated for C15H17NO: C, 79.26; H, 7.54; N, 6.16. Found: C, 79.98; H, 7.65; N, 6.22.
EXAMPLE XXII
A solution of acetophenone (120ml), o-anisidine (123ml), benzene (lOOml) was refluxed with continuous removal of water.
The crude product was purified by crystallizing it from ethanol to give N-(amethyl benzylidene)-o-anisidine (IX) (9OC). It was then hydrogenated using 5% Pd/C as the catalyst and 95% ethanol as the solvent to give N~ -methyl benzyl)-o-anisidine (X). X had a boiling point of 117C at 0.3 millimeter.
Analysis calculated for C15H17NO: C, 79.26; H, 7.54; N, 6.16. Found: C, 79.42; H, 7.72; N, 6.32.
EXAMPLE _XIII
A. A solution of acetophenone (44ml), ethyl-p-amino-benzoate (60g), benzene (lOOml) was refluxed in the presence of molecular sieve (lOOg) with continuous removal of water. The crude product was purified by crystallizing it from ethanol to give N-(-methyl benzylidene)-p-carbethoxy aniline (XI). XI had a m.p. of 87C.
Analysis calculated for C17H17N02: C, 76.38; H, 6.41; N, 5.24. Found: C, 76.59; H, 6.37; N, 5.33.
B. N-(o~-methyl benzylidene)-p-carbethoxyaniline (XI) prepared by the procedure described in example XXIIA was hydrogenated using 5% Pd/C as the catalyst and 95% e-thanol as the solvent t(> give N-(o~-methyl benzyl)-p-carbethoxy aniline (XII).
XII had a m.p. of 88C.
Analysis calculated for (_17H1gN02: C, 76.38; H, 6.41; N, S .24. Found: C, 76.58; H, 6.37; N, 5.33.
EXAMPLE XXIV
- A. A solution of acetophenone (95ml), m-carbethoxy aniline (75ml), benzene (150ml) was refluxed in the presence of molecular sieve (50g) with continuous removal of water. The crude product was distilled under reduced pressure to give N- (a-methyl benzylidene)-m-carbethoxyaniline (XIII). XIII had a boiling point of 205C at 0.1 millimeter.
Analysis calculated for C17H17N02: C, 76.38; H, 6 41; N, ; 5.24. Found: C, 75.96; H, 6.34; N, 5.32.
B. N-(o~-methyl benzylidene)m-carbethoxyaniline (27g) prepared by the procedure described in example VIIA was hydro-genated using 5% Pd/C as the catalyst and 95% ethanol as the solvent. N-(~-methyl benzyl m-carbethoxy aniline (XIV) was obtained by fractional distillation. XIV had a boiling point of 156C
at 0.1 millimeter.
Analysis calculated for C17H1gN02: C, 76.38; H, 6.41; N, 5.24. Found: C, 75.60; H, 6.96; N, 5.36.
~ EXAMPLE XXV
j - A. A solution of acetophenone (lOOml), o-carbethoxy-aniline (9Oml), benzene (lOOml) was refluxed in the presence of molecular sieve (40g) with continuous removal of water. N-(o~-methyl benzylidene)-o-carbethoxyaniline (XV) was obtained by fractional distillation . XV had a boiling point of 123 at 0.1 millimeter.
Analysis calculated for C17H17N02: C, 76.38; H, 6.41; N, 5.24.
B. N-(~-methyl benzylidene)-o-carbethoxyaniline (13g) prepared by the procedure described in example XXVA was hydrogenated using 5% Pd/C as the catalyst and 95% ethanol as the solvent. N-(-methyl benzyl)-o-carbethoxyaniline (XVI) (12g) was obtained by fractional distillation. XVI had a boiling point of 168C
at 1.4 millimeter.

Analysis calculated for C17H1gNO2: C, 76.38; H, 6.41; N, 5.24. ~ound: C, 76.50; H, 7.04; ~il, 5.28.
EXAMPLE XXVI
A solution of acetophenone (132ml), p-chloroaniline (128g) benzene (150ml) was refluxed in the presence of molecular sieve (40g) with continuous removal of water. The crude product was crysta~lized from ethanol to give p-chloro-N-(a-methyl benzylidene) aniline (XVII ) . It was then hyclrogenated using 5% Pd/C as the catalyst and 95% ethanol as the solvent. The crude product was crystallized from ethanol and pet. ether to give p-chloro-N-~X-methyl benzyl) aniline (XVIII). XVIII had a melting point of 62C.
Analysis calculated for C14H14CIN: C, 72.56; H, 6.08; N, 6.04. Found: C, 72.80; H, 6.19; N, 6.15.
EXAMPLE XXVII
A. A solution of acetophenone (130ml), m-chloroaniline (130ml) and benzene (200ml) was refluxed in the presence of molecular sieve (50g) with continuous removal of water. m-Chloro-N-(o~-methyl benzylidene) aniline (XIX) was obtained by fractional distillation. XIX had a boiling point of 110C at 0.025 millimeter.
Analysis calculated for C14H12ClN: C, 73.20; H, 5.26; N, 6.09. Found: C, 73.60; H, 5.19; N, 6.23.
B . m-Chloro-N- (cx-methyl benzylidene) aniline (XIX) (24g) prepared by the procedure described in example XXVIIA was hydrogenated using 5% Pd/C as the catalyst and 95% ethanol as the solvent. m-Chloro-N-(a~-methyl benzyl) aniline (XX) was obtained by fractional distillation. XX had a boiling point of 133C at 0.15 millimeter.
Analysis caiculated for C14H14ClN: C, 72.56; H, 6.08; N, 6.04. Found: C, 72.63; H, 6.16; N, 6.26.
EXAMPLE XXVIII
A. A solution of acetophenone (130ml), 2-chloroaniline (130ml) and benzene (200ml) was refluxed in the presence of molecular sieve with continuous removal of water. o-Chloro-N-(o~-methyl benzylidene) aniline (XXI) was obtained by fractional distillation. XXI had a boiling point of 111C at 0.1 millimeter.
Analysis calculated for C14H12ClN: C, 73.20; H, 5.26; N, 6.09. Found: C, 73.38; H, 5.20; N, 6.25.

' r B. o-Chloro-N-(oc-methyl benzylidene) aniline (XXI) (15g) prepared hy the procedure (lescribed in example XXVIIIA was hydrogenated using 5% Pd/C as the catalyst and 95% ethanol as the solvent. o-Chloro-N-~x-methyl benzyl) aniline (XXII) was obtained 5 by fractional distillation. XXII had a boiling point of 134~C at 1.2 millimeter .
Analysis calculated for C14H14ClN: C, 72.56; H, 6.08; N, 6.04. Found: C, 73.38; H, 6.05; N, 6.23.
EXAMPLE XXIX
A. A solution of p-diacetylbenzene (50g), aniline (80g) and benzene (120ml) was refluxed in the presence of molecular sieve (lOg) with continuous removal of water. The crude product was crystallized from ethanol to give p-acetyl-N-(~-methyl benzylidene) aniline (XXIII). XXIII had a melting point of 205C.
B. p-Acetyl-N-(o~-methylbenzylidene) aniline (XXIII) (30g) prepared by the procedure described in Example XXIXA was hydrogenated using 5% Pd/C as the catalyst and 95% ethanol as the solvent. p-Acetyl-N-(~c-methyl benzyl) aniline (XXIV) was obtained by fractional distillation. XXIV had a boiling point of 165C at 0.1 millimeter.
Analysis calculated for C16H17NO: C, 80.30; H, 7.16; N, 5.85. Found: C, 80.00; H, 7.46; N, 5.50.
EXAMPLE XXX
A mixture of p-acetyl-N- (ot-methyl benzylidene) aniline (XXIII) (40g) prepared by the procedure described in example XXIXA and aniline (20ml) was hydrogenated using 5% Pd/C as the catalyst and 95% ethanol as the solvent. The crude product was crystallized from ethanol to give 1,4-Bis-(1-anilinoethyl) benzene (XXV). XXV had a melting point of 169-170C.
EXAMPLE XXXI
A. A solution of o~-tetralone (50ml), dodecyl aniline (80g~ and benzene (150ml) was refluxed in the presence of molecular sieve (lOOg) with continuous removal of water. The crude product was crystallized from ethanol to give N-(1,2,3,4-tetrahydronaphthylidene) aniline (XXVI). XXVI had a melting point of 53C.

Analysis calculated for (,28H39N: C, 86.31; H, 10.09; N, 3.59. Found: C, 87.91; H, 10.05; ~, 3.76.
B. N-(1,2,3,4-tetrahydronaphthylidene) aniline (XXVI) (38g) prepared as described in example XXXIA was hydrogenated 5 using 5% Pd/C as the catalyst and 95% ethanol as the solvent. The crude product was crystallized from ethanol to give 1- (p-dodecyl-anilino)-1,2,3,4-tetrahydronaphthalene (XXVII). XXVII had a melting point of 34C.
AnalysiS calculated for C28H41N C, 85.87; H, 10 55; N, 3.57. Found: C, 86.40; H, 10.69; N, 3.78.
EXAMPLE XXXII
A. A solution of ~x-tetralone (40ml), ethyl-p-amino-benzoate (42g) and benzene (lOOml) was refluxed in the presence of molecular sieve (lOOg) with the continuous removal of water. The 15 crude product was crystallized from ethanol to give N-(1,2,3,4-tetrahydonaphthylidene)-p-carbethoxyaniline (XXVIII). XXVIII had a m . p . of 108.5C .
Analysis calculated for C1gH1gN02: C, 77.78; H, 6.58; N, 4.77. Found: C, 77.95; H, 6.42; N, 4.85.
B . N- (1,2,3,4-Tetrahydronaphthylidene)-p-carbethoxy-aniline (XXVIII) (30g) prepared by the procedure described in example XXXIIA was hydrogenated using 5% Pd/C as the catalyst and 95% ethanol to give 1-(p-carbethoxy-anilino)-1,2,3,4-tetrahydronaphthalene (XXIX). XXIX had a melting point of 34C.
Analysis calculated for C1gH21N02: C, 77.26; H, 7.17; N, 4.74. Found: C, 77.84; H, 7.27; N, 4.92.

Claims (2)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An antioxidant chosen from the group consisting of N-(alpha-methyl-p-octylbenzyl)aniline; N-(alpha-methyl-p-non-ylbenzyl)aniline; N-(alpha-methyl benzyl)-p-nonylaniline; N-(alpha-methyl benzyl)-m-dodecylaniline; N-(alpha-methyl benzyl)-o-methoxyaniline; N-(alpha-methyl benzyl)-o-methoxyaniline; N-(alpha-methyl benzyl-m-carbethoxyaniline; N-(alpha-methyl benzyl) -o-carbethoxyaniline; N-(alpha-methyl benzyl)-p-chloroaniline; N-(alpha-methyl benzyl)-m-chloroaniline; N-(alpha, methyl benzyl)-o -chloroaniline; l-(p-dodecylanilino)-1,2,3,4-tetrahydronaphthalene;
l-(p-carbethoxyanilino)-1,2,3,4,-tetrahydronaphthalene; N-(p-ace-tyl-alpha-methyl benzyl)aniline; and 1,4-bis-(1-anilinoethyl) benzene.

2. The antioxidant according to claim 1 wherein the antioxi-dant is N-(alpha-methyl-p-octylbenzyl)aniline or N-(alpha-methyl benzyl)-p-nonylaniline.