Note: Descriptions are shown in the official language in which they were submitted.
i~84~335
BACKGROUND OF THE INVENTION
This invention relates to an improved lubricating
composition, and more particularly, this invention relates to a
lubricating composition containing an additive combination having
improved antioxidation properties.
Hydrocarbon oils are partially oxidized when contacted
with oxygen at elevated temperatures for long periods. The
internal combustion engine is a model oxidator, since it contacts
a hydrocarbon motor oil with air under agitation at high
temperatures. Also, many of the metals (iron, copper, lead,
nickel, etc.) used in the manufacture of the engine and in
contact with both the oil and air, are effective oxidation
catalysts which increase the rate of oxidation. The oxidation in
motor oils is particularly acute in the modern internal
combustion engine which is designed to operate under heavy work
loads and at elevated temperatures.
The oxidation process produces acidic bodies within the
motor oil which are corrosive to typical copper, lead, and
cadmium engine bearings. It has also been discovered that the
oxidation products contribute to piston ring sticking, the
formation of sludges within the motor oil and an overall
breakdown of viscosity characteristics of the lubricant.
Several effective oxidation inhibitors have been
developed and are used in almost all of the conventional motor
oils today. Typical of these inhibitors are the sulfurized oil-
soluble organic compounds, such as wax sulfides and polysulfides,
sulfurized olefins, sulfurized fatty acid esters, and sulfurized
olefin esters, as well as zinc dithiophosphates and the oil-
soluble phenolic and aromatic amine antioxidants. These
inhibitors, while exhibiting good antioxidant properties, are
burdened by economic and oil contamination problems. It is
- 3 - ~ ~L
1~4~35
preferred to maintain the sulfur content of the oil, as low as
possible, while at the same time receiving the benefits of the
antioxidation property. A need, therefore, exists for an
improved antioxidant that is stable at elevated temperatures,
that can be employed in reduced concentrations, and that is
economical and easy to produce.
DESCRIPTION OF THE PRIOR ART
.
United States Patent 2,718,501 discloses a synergistic
mixture of a sulfur-containing compound, such as a wax sulfide or
dioctadecyl disulfide, and an aromatic amine compound having at
least 2 aromatic rings, such as phenyl alpha-naphthyl amine, for
use in preventing oxidation in lubricating oils.
United States Patent 2,729,691 discloses a mixture of
an arylamine antioxidant and a synergistic amount of an
alkylenediamine for protecting organic material from oxidation.
United States Patent 2,958,663 discloses an extreme
pressure lubricant composition containing from 0.01 to 5 percent
each of sulfurized oleic acid, C18-C22 alkenyl succinic acid,
chlorinated paraffin wax containing from 20 to 60 percent chlorine,
diphenylamine and N,N-salicylal-1,2-propylenediamine.
United States Patent 3,345,292 discloses stabilized alkyl
substituted diaryl sulfides for use as functional fluids where
the stabilizer can be diaryl amine or alkylated phenol.
It is an object of this invention to provide additive
compositions for crankcase lubricating oils which impart improved
antioxidant properties. It is a further object of this invention
to provide a synergistic additive composition having antioxidant
properties in crankcase lubricating oil compositions.
SUMMARY OF THE INVENTION
A lubricating oil additive composition which imparts
improved oxidation properties to lubricants comprises an
1~4~35
antioxidant selected from aromatic or alkyl sulfides and poly-
sulfides, sulfurized olefins, sulfurized carboxylic acid esters
and sulfurized ester-olefins, and an amine of the formula
R-NH2' (R )2NH, ~R )3N, R l I (C 2)~ y 2
~R ~N-A ~ ,N~A -OH) , or Het N~R ) ,X
wherein each R is independently alkyl or alkenyl of at least 6
carbon atoms, each Rl is independently an aliphatic hydrocarbon
group, each R2 is independently C3-C10 alkyl, phenyl, or phenyl
substituted by 1 or 2 alkyl groups of 1-12 carbon atoms, R3 is
Cl-C30 alkyl, R4 is alkylene of at least 2 carbon atoms, each A
is independently hydrogen or Cl-C18 alkyl, each Al and A2 is
independently C2-C10 alkylene, X is hydrogen, -OH, or -NA2, Y is
hydrogen, Cl-C6 alkyl, or Al-OH, Het is a carbon chain forming
with the N atom a 5- or 6-membered heterocyclic ring, optionally
containing in place of one carbon atom an additional N or 0
hetero atom, x is an integer from 2 to 4, x' is 1 or 2, y is an
integer from 1 to 4, y' is 0 or 1, and y" is 0, 1 or 2, with the
proviso that when y' is 0, X is hydrogen.
As a second embodiment, there is provided a lubricating
oil composition comprising an oil or lubricating viscosity and an
antioxidant amount of the composition described above.
It has been found that the defined antioxidants in
combination with the defined amines complement each other in a
synergistic manner, resulting in a combination having antioxidant
properties superior to either additive alone. The amine
component alone has virtually no antioxidant effect. However,
when the defined combination of amine and antioxidant is added to
a lubricating oil, less of the antioxidant is needed to obtain
oxidation control than when the amine is not present.
-- 5 --
4~35
Preferably, from 2 to 40 millimols of an oil-soluble
zinc salt is present per kilogram of the lubricating oil
composition. While this zinc salt is not required to achieve the
synergistic effect from the combination of the antioxidant and
the amine, an improved lubricating oil composition results from
the use of all three additive components.
DETAILED DESCRIPTION OF THE INVENTION
. _ _ _ _
The compositions of this invention are highly stable
additives for crankcase lubricating oils and impart excellent
antioxidant properties to these oils.
In a preferred embodiment of the lubricating oil
composition, 0.25 to 10 weight percent of the antioxidant is
present and 0.001 to 5 weight percent of the amil~e is present.
The weight ratio of the antioxidant to amine is ordinarily in
the range of 1 to 0.001-21.
More preferably, 0.25 to about 2 weight percent of the
antioxidant is present in the lubricating oil. More preferably,
the amine is present in the amount of 0.01 to 0.3, preferably
0.05 to 0.3 weight percent.
In a further preferred embodiment, from 9 to 30 mmols
per kilogram of the oil-soluble zinc salt is present.
ANTIOXIDANT COMPONENT
The class of antioxidants which may be used are
conventional sulfur-containing antioxidants such as wax sulfides
and polysulfides, sulfurized olefins, sulfurized carboxylic acid
esters and sulfurized ester-olefins.
The sulfi~rized fatty acid esters are prepared by
reacting sulfur, sulfur monochloride, and/or sulfur dichloride
with an unsaturated fatty ester under elevated temperatures.
Typical esters include Cl-C20 alkyl esters of C8-C24 unsaturated
fatty acids, such as palmitoleic, oleic, ricinoleic,
-- 6 --
-- 1~84~35
petroselinic, vaccenic, linoleic, linolenic, oleostearic,
licanic, paranaric, tariric, gadoleic, arachidonic, cetoleic,
etc. Particularly good results have been obtained with mixed
unsaturated fatty acid esters, such as are obtained from animal
fats and vegetable oils, such as tall oil, linseed oil, olive
oil, castor oil, peanut oil, rape oil, fish oil, sperm oil, and
so forth.
Exemplary fatty esters include lauryl tallate, methyl
oleate, ethyl oleate, lauryl oleate, cetyl oleate, cetyl
linoleate, lauryl ricinoleate, oleyl linoleate, oleyl stearate,
and alkyl glycerides.
Cross-sulfurized ester olefins, such as a sulfurized
mixture of C10-C25 olefins with fatty acid esters of C10-C25
fatty acids and Cl-C25 alkyl or alkenyl alcohols, wherein the
fatty acid and/or the alcohol is unsaturated may also be used.
Sulfurized olefins which may be used as an antioxidant
in the practice of this invention are prepared by the reaction of
the C3-C6 olefin or a low-molecular-weight polyolefin derived
therefrom with a sulfur-containing compound such as sulfur, sul-
fur monochloride, and/or sulfur dichloride.
Another class of organic sulfur-containing compounds
which may be used is sulfurized aliphatic esters of an olefinic
mono- or dicarboxylic acid, for example aliphatic alcohols of 1-
30 carbon atoms, used to esterify monocarboxylic acids such as
acrylic acid, methacrylic acid, 2,4-pentadienoic acid and the
like, or fumaric acid, maleic acid, muconic acid, and the like.
Sulfurization is carried out by combining these esters with
elemental sulfur, sulfur monochloride and/or sulfur dichloride.
The preferred antioxidants are the aromatic and alkyl
sulfides, such as dibenzylsulfide, dixylyl sulfide, dicetyl
sulfide, diparaffin wax sulfide and polysulfide, cracked wax-
1~4~S
olefin sulfides and so forth. They can be prepared by treating
the starting materiall e.g., olefinically unsaturated compounds,
with sulfur, sulfur monochloride, and sulfur dichloride.
Particularly preferred are the paraffin wax thiomers described
in United States Patent 2,346,156.
All of the sulfides and polysulfides included within
the scope of this invention are sulfurized sulfides and poly-
sulfides. That is, the sulfide or polysulfide has been reacted
with additional sulfur, sulfur monochloride or sulfur dichloride
after the initial formation of the sulfide. Residual chlorine
that may be present in the antioxidant after sulfurization is
not detrimental and may be beneficial.
THE AMINE COMPOUNDS
The second component of the additive composition for
use in lubricating oils may be a primary, secondary or tertiary
amine or a hydroxy amine.
The Primary Amines
The primary amines are mainly those compounds defined
by the following formulas:
R-NH2 or R ~ N-(CH2) ¦ yNH2 or Het N~R4 ~ X
wherein each A is independently hdyrogen or Cl-C18 alkyl, R is
alkyl or alkenyl of at least 6 carbon atoms, R4 is an alkylene of
at least 2 carbon atoms, x is an integer from 2 to 4, y is an
integer from 1 to 4, and Het is a carbon chain forming with the N
atom a 5- or 6-membered heterocyclic ring optionally containing
in place of one carbon atom an additional N or 0 hetero atom, X
is hydrogen or, when y' is 1, NH2, and y' is 0 or 1.
Preferably A is hydrogen, x is 2, R contains at least
12 carbon atoms and R3 is alkyl of 2 to 12, more preferably 2 to
-
1~84~35
6, carbon atoms. Also, in the polyamine compounds, it is
preferred that the R group have from about 30 to about 250,
preferably 30 to 120, carbon atoms. R as polyisobutylene is
particularly preferred for the polyamine compounds.
When R is alkenyl, the alkenyl portion preferably has
1 to 2 olefinically unsaturated linkages per molecule. If a
totally saturated group, is desired, the compound containing,
e.g. a polyisobutylene group, can be hydrogenated with hydrogen
over a noble metal catalyst, such as platinum, using conventional
hydrogenation techniques.
The R group may be either branched or unbranched
hydrocarbon. In the monoamine compounds, R is preferably alkyl
of 12 to 22 carbon atoms, and more preferably is octadecyl.
The heterocylic primary amines included within the
invention have 5- or 6-membered heterocyclic rings containing at
least one nitrogen atom and optionally an additional nitrogen or
oxygen hetero atom. The heterocyclic ring designated He~__JN- can
be saturated or unsaturated and is preferably piperazinyl,
piperidinyl, imidazolyl, morpholinyl, pyrazolyl or pyridyl. The
heterocyclic ring may be substituted by one or more alkyl groups
which do not affect the synergistic activity of the amine.
The compounds included within the scope of the above
formula are compounds whose methods of preparation are well
known.
The Secondary Amines
The secondary amines are primarily those of the formula
(R1)2NH or He N-(R4) ,X
In the aliphatic amines each R is independently an aliphatic
hydrocarbon group. The total number of carbon atoms in the
groups must be sufficient to render the compound oil soluble.
1~84~5
Preferably each R contains from 6 to 30 carbon atoms, and more
preferably from 6 to 18 carbon atoms. In preferred compounds, R
and Rl are saturated, straight-chain alkyl radicals.
For the heterocyclic compounds, Het is a carbon chain
forming with the N atom a 5- or 6-membered heterocyclic ring
optionally containing in place of one carbon atom an additional N
or O hetero atom, and y' is O or 1. When y' is 0, X is hydrogen.
When y' is 1, R4 is alkylene of at least 2 carbon atoms and X is
hydrogen or HNA wherein A is Cl-C18 alkyl. When X is hydrogen,
the ring Het N- contains an addition nitrogen atom bonded to one
hydrogen atom. An example of this type of compound is an alkyl
piperazine of the formula
~
HN 1-18 Y
The ring may be substituted by one or two alkyl groups that do
not affect the synergistic activity of the amine.
The preparation of these compounds is well known in the
art. Typical compounds are di-n-decylamine, di-n-hexadecylamine,
di-n-octadecylamine, and the like. Other typical compounds are
those where the hydrocarbon portion of the compound is derived
from mixtures of fatty acids. Preferred are those mixtures
derived from coconut oil or soya bean oil. The amine derived
from coconut oil (designated "dicocoamine") is particularly
preferred. The coconut oil is hydrolyzed to yield an amine
wherein each R group contains from 6 to 18 carbon atoms and the
majority of the R groups contains 10, 12 or 14 carbon atoms.
The Tertiary Amines
The oil-soluble tertiary amines are primarily those of
the formula (R2)3N or He N-(R4) ,-X. In the non-heterocyclic
compounds, each R2 is independently C3-C10 alkyl, phenyl, or
- 10 -
1~84Q~5
phenyl substituted by 1 or 2 alkyl groups of up to 12 carbon atoms.
Preferably each R is the same and is selected from C3-C6 alkyl or
phenyl.
Typical alkyl-substituted phenyl groups include tolyl,
xylyl, tetrapropenylphenyl, octylphenyl, and the like.
For the heterocyclic compounds, Het is a carbon chain
forming with the N atom a 5- or 6-membered heterocyclic ring
optionally containing in place of one carbon atom an additional N
or 0 hetero atom, R4 is alkylene of at least 2 carbon atoms, y'
is 1, and X is hydrogen or -NA2 where each A is independently Cl-
C18 alkyl. Each N atom has no bonds directly to a hydrogen atom.
The ring may be substituted by one or two alkyl groups that do
not affect the synergistic activity of the amine.
The compounds are conventional compounds that can be
prepared by well-known methods.
The Hydroxy Amines
The oil-soluble hydroxy amines are primarily those of
the formula
y 3 X-,N~A2-OH)x, or Het N~R4~ ,X
wherein each A and A is independently C2-C10 alkylene, R is
Cl-C30 alkyl, Y is H, Cl-C6 alkyl or -Al-OH, y" is 0, 1 or 2, and
x' is 1 or 2, Het is a carbon chain forming with the N atom a 5-
or 6-membered heterocyclic ring, optionally containing in place
of one carbon atom an additional N or 0 hetero atom, R4 is alkyl
of at least 2 carbon atoms, y' is 1, and X is OH.
Particularly preferred heterocyclic compounds are those
of the formula
- 11 -
1~84~}5
R3
N ~ N-(R4) ,OH
In a preferred non-heterocyclic embodiment, A is
ethylene and A is trimethylene, Y is H or -A2-OH, R3 is Cl-C20
alkyl, and most preferably C16-C18 alkyl, x' is 2 and y" is 1.
The preparation of the imidazoline compounds is
disclosed in United States Patents 2,974,022, 2,839,371,
2,839,372 and 2,839,373.
The compounds included within the scope of the above
formula are compounds whose methods of preparation are well
known.
THE OIL-SOLUBLE ZINC SALT
The zinc salts which may be used in this invention are
oil-soluble zinc salts. They are used in the lubricating oil to
supply from 9 to 40 mmols of zinc per kilogram of oil.
The zinc salt is preferably a zinc dihydrocarbyldithio-
phosphate having from 4 to 20 carbon atoms in each hydrocarbyl
group. The zinc dihydrocarbyldithiophosphate is formed by reacting
the corresponding dihydrocarbyldithiophosphoric acid with a zinc
base, such as zinc oxide, zinc hydroxide and zinc carbonate. The
hydrocarbyl portions may be all aromatic, all aliphatic, or mix-
tures thereof.
Exemplary zinc dihydrocarbyldithiophosphates include:
zinc di~n-octyl~dithiophosphate,
zinc butyl isooctyl dithiophosphate,
zinc di(4-methyl-2-pentyl)dithiophosphate,
zinc di(tetrapropenylphenyl)dithiophosphate,
zinc di(2-ethyl-1-hexyl)dithiophosphate,
zinc di(isooctyl)dithiophosphate,
zinc di(hexyl)dithiophosphate,
zinc di(ethylphenyl)dithiophosphate,
- 12 -
i~84~35
zinc di(amyl)dithiophosphate,
zinc di(alkylphenyl)dithiophosphate,
zinc butylphenyldithiophosphate, and
zinc di(octadecyl)dithiophosphate.
Preferred compounds are those zinc dihydrocarbyl- -
dithiophosphates having from 4 to 18 carbon atoms in each
hydrocarbon group. Especially preferred are the zinc
dialkyldithiophosphates wherein each alkyl group typically
contains from 4 to 8 carbon atoms and the zinc di(alkylaryl)-
dithiophosphates wherein each alkylaryl group contains from
15 to 21 carbon atoms.
The lubricating oil composition is prepared by
admixing, by conventional mixing techniques, the desired amount
of antioxidant and amine in a suitable lubricating oil. The
selection of the particular base oil and amine, as well as the
amounts and ratios of each, depends upon the contemplated
application of the lubricant and the presence of other additives.
Generally, however, the amount of oil-soluble antioxidant
employed in the lubricating oil will vary from 0.25 to 10, and
usually from 0.25 to 2, weight percent. The primary amine will
range from 0.01 to 2, and usually from 0.01 to 0.3, preferably
from 0.05 to 0.3, weight percent based on the weight of the final
composition. The weight ratio of oragnic oil-soluble antioxidant
to amine will generally vary from 5-20 to 1, and usually from 10-
20 to 1.
Concentrates of the new additive composition of this
invention can be prepared for easier handling and storage of the
additive. Usually the concentrate will be 10 to 90% by weight
additive composition and from 10 to 90% by weight lubricating oil
diluent. Preferably the additive composition comprises 20 to 80%
by weight of the lubricating oil additive concentrate. This
concentrate is diluted with additional oil before use.
- 13 -
1~4~35
The lubricating oil which may be used includes a wide
variety of hydrocarbon oils such as naphthenic base, paraffin
base, and mixed base oils. Other oils include lubricating oils
derived from coal products and synthetic oils, e.g., alkylene
polymers (such as propylene, butylene, and so forth, and mix-
tures thereof), alkylene oxide-type polymers (e.g~ alkylene oxide
polymers prepared by polymerizing alkylene oxides, such as ethy-
lene oxide, propylene oxide, etc. in the presence of water or
alcohol, e.g. ethyl alcohol~, carboxylic acid esters ~e.g. those
which are prepared by esterifying carboxylic acids, such as
adipic acid, azelaic acid, suberic acid, sebacic acid, alkenyl-
succinic acid, fumaric acid, maleic acid and so forth, with an
alcohol such as butyl alcohol, hexyl alcohol, 2-ethylhexyl
alcohol, pentaerythritol and so forth, liquid esters of phos-
phorus-containing acids such as trialkyl phosphate, tricresyl
phosphate, etc., alkylbenzenes, polyphenyls (e.g., biphenyls and
terphenyls), alkylbiphenyl ethers, esters and polymers of
silicon, e.g., tetraethylsilicate, tetraisopropylsilicate,
hexyl(4-methyl-2-pentoxy)disilicate, poly(methyl)siloxane, and
poly(methylphenylsiloxane) and so forth. The lubricating oils
may be used individually or in combinations whenever miscible,
or whenever made so by use of mutual solvents. The lubricating
oils generally have a viscosity which ranges from 50 to 5000 SUS
(Saybolt Universal Seconds), and usually from 100 to 1500 SUS at
100F.
In addition to the antioxidant, the amine compound and
the oil-soluble zinc salt, other additives may be used in the
lubricating composition without affecting its high stability and
performance over a wide temperature scale. One type of additive
which may be used is a rust inhibitor. The rust inhibitor is
used in many types of lubricants to suppress the formation of
- 1~84035
rust on the surface of metallic parts. Typical rust inhibitors
include sodium nitrite, alkenylsuccinic acid and derivatives
thereof, alkylthioacetic acid and derivatives thereof, poly-
glycols and derivatives thereof, and alkoxylated amines and
derivatives thereof. Other types of lubricating additives which
may be used are metallic or ashless dispersants and detergents.
Typical of these are the conventional succinimides, succinates,
hydrocarbylalkylene polyamines, alkaline earth metal salts of
alkylaryl sulfonates, phenates and the like.
Other types of lubricating oil additives which may be
used include antifoam agents (e.g., silicones, organic copolymers),
stabilizers and antistain agents, tackiness agents, antichatter
agents, dropping point improvers and antisquawk agents, lubricant
color correctors, extreme-pressure agents, odor control agents,
detergents, antiwear agents, thickeners, and so forth.
LUBRICANT PERFORMANCE
The presence of the amine in the lubricant composition
increases the antioxidation properties of the oil-soluble, sulfur-
containing antioxidant. With this combination, less of the anti-
oxidant is necessary in the lubricant to achieve the desired
antioxidation properties. If the antioxidant is used at conven-
tional levels, increased oxidation protection is obtained.
The following examples are presented to illustrate the
practice of specific embodiments of this invention and should not
be interpreted as limitations on the scope of this invention.
EXAMPLE 1
The combination of the amines with this antioxidant in
improving the antioxidation properties of a lubricating oil over
the use of either of the components individually is illustrated
by the following test. The oxidation test uses the resistance of
1~841D35
the test sample to oxidation using pure oxygen with a Dornte-type oxygen
absorption apparatus (R.W. Dornte, "Oxidation of White Oils", Industrial
and Engineering Chemistry, Vol. 28, page 26, 1936). The conditions are an
atmosphere of pure oxygen exposed to the test oil maintained at a temperature
of 340F. The time required for 100 g of test sample to adsorb 1000 ml of
oxygen is observed and reported in the following Table I. The test oil in
sections A, E, F and G is Midcontinent neutral oil containing 6% of a
conventional succinimide dispersant, 0.05% terephthalic acid, 0.4% of a
conventional rust inhibitor, and 9 m mols/kg of a zinc dithiophosphate.
The test oil in sections B, C and D is a refined mineral oil.
TABLE I
Oxidation
Antioxidant 0.1% Primary Amine Life/Hrs.
_~_________________ __________________________________ _ ______________
__ __ 5.2
A) 1% diparaffin - 6.4
polysulfide
0.5
1% diparaffin dodecylamine 8.6
polysulfide
" 2-ethylhexylamine 8.0
" Primene JMT * 7.1
" Duomeen T * 7.5
" oleyl-NH(cH2)3NH2 6.6
" PB12EDA 6.9
24EDA o . 66
1% diparaffin 24 9.8
polysulfide
32EDA5 8.0
- N-(2-aminoethyl)piperazine 5.2
1% diparaffin " 10.1
polysulfide
*Trade mark
- 16 -
C~.
-
1084035
1 - bis(aminopro~yl~ethylene di~mine 4.8
2 lh diparaffin ll 10.4
3 polysulfide
4 B)50 mmols/kg diparaf- - 3.18 fin polysulfide
6 (18.0~ S)
7 " 10 ~mols/kg octadecylamine 15.75
8 ~' (l5.9~ S) - 4.80
9 " " 10 mmolsfkg octadecylamine 17.77
50 mmols/kg sulfur- - 2.33
11 ized ester (9.88~ S)
12 " 10 mmols/kg o~tadecylamine 5.17
13 " (14.5~ S) - 1.03
14 " " 10 mmols/kg octadecylamine 4.80
C)50 mmols/kg diparaf- - 5
16 fin polysulfide
17 " 2.5 mmols~kg octaae_ylamine 11
18 " 10 " " 18
19 " 20 " ~' . 18
" 50 " " 21
21 D)32.5 mmols/kg diparaf- - 0.9
22 fin polysulfide
23 " 2.5 mmols/kg octadecylamine 1.3
24 " 10 " " 9.5
" 20 " " 3.0
26 ~ 50 - " 9 5
27 25 " - 0
28 " 2.5 mmols~kg octade_yla~ine 0
29 ~ 10 ~ 0.8
" 50 " " 1.3
31 ~C~3
32 ~R-~ NH2 where the R group has approximately
33 ~ 18 carbon atoms
34 ~H3
- 17 -
1~84~35
C 1 8H37NH (CH2) 3NH2
Reaction product of ethylene diamine (EDA) and polyisobutenyl chloride having
a number average molecular weight of 530.
Reaction product of EDA and polyisobutenyl chloride having a number average
molecular weight of 950.
5Reaction product of EDA and polyisobutenyl chloride having a number average
molecular weight of 1400.
6Base oil contains no zinc dithiophosphate.
Oxidation
E) Antioxidant Secondary Amine Life/Hrs.
- 0.1% dicocoamine 0.48
1% diparaffin - 6.1
polysulfide
" 0.1% dicocoamine 8.9
" 0.2% di-n-hexylamine 13.8
" 0.1% disoyamine 7.4
" 0.1% dioctylamine 8.6
" 0.1% di(2-ethylhexyl)amine8.6
Base oil without zinc dithiophosphate
Average of 3 tests
Oxidation
F) Antioxidant Tertiary Amine Life/Hrs.
1% diparaffin - 6.4
polysulfide
" 0.1% tributylamine 7.5
- 18 -
1~84~35
Oxidation
G2 Antioxidant Hydroxy Amine Life/Hrs
_ 5.1
_ 0.1% A4 4.6
1% diparaffin - 6.4
polysulfide
,. 0.1% A4 8.6
" 0.1% Ethomeen 18-121* 8.5
" 0.1% Ethoduomeen T-122*9.4
" 0.1% Ethoduomeen T-133*7.2
Cl8H37N~cH2cH2oH)2
2C18H37-~-CH2CH2CH2-N~CH2CH2 )2
H
18H37 7-CH2cH2cH2-N~cH2cH2oH)2
CH2CH20H
R
4A is N / \ N-CH2CH20H where R is C12 C17 y
EXAMPLE 2
The resistance to increase in viscosity of lubricating oils
containing an antioxidant composition of this invention as compared to
antioxidant alone is illustrated by the following engine test. In this
test, an Oldsmobile* engine is charged with 10.65 pounds of the oil to be
tested. The engine is then started and run for 2 minutes at 850 rpm with no
load. The rpm's are then increased to 1500 with a 50-pound load and 450 psi
oil pressure, and the engine is run for 8 minutes. The engine is shut
down with the oil circulating for 10 minutes. The oil pump is then shut down
and the oil sampled after 5 minutes. This procedure is repeated until the
viscosity of the oil increases 500%. The number of hours elapsed during the
test is recorded.
* Trade mark
' I - 19 -
i~841~5
The base oil used in this test is a Midcontinent neutral oil
having a viscosity of 350 SUS at 100F, 6% wt of a conventional succinimide
dispersant, 0.05% wt of terephthalic acid, and 0.4~ wt of a conventional rust
inhibitor. The results of this test are reported in Table II.
TABLE II
Hours to reach
Antioxidant Secondary Amine 500% Visc. 100F
28
2% diparaffin
polysulfide - 52
1% diparaffin 232% vis. incre~se
polysulfide 0.1% dicocoamine after 142 hours
lEngine test was terminated because of electronic problems.
AntioxidantHydroxy Amine Hours
500% Visc. 100F
- 28
2% diparaffin polysulfide - 52
2% diparaffin polysulfide 0.2% Al 93
A is as defined at page 19, line 21.
The test procedure of Example 2 was repeated in a formulation
containing 6% of a conventional succinimide dispersant, 40 mmols per kg of a
calcium phenate and 18 mmols per kg of a zinc dithiophosphate. The results
are shown in Table III.
TABLE III
Hours to 500%
AntioxidantSecondary Amine Yisc. Incre~se
_ _ 44,56
2% diparaffin polysulfide - 92
2% diparaffin polysulfide 0.2% dicocoamine 123
2% sulfurized cracked wax
olefin (13% S) 0.2% dicocoamine 72
2% sulfurized cracked wax
olefin ~24% S) 0.2% dicocoamine ~166
The symbol > means "greater than".
- 20 -
~,v
