Lubricating oil and fuel compositions

Engine friction of internal combustion engines is reduced by adding to the lubricating oil or fuel used in such engine a small friction-reducing amount of an aliphatic hydrocarbylsulfonylalkanol or aliphatic hydrocarbylsulfinylalkanol resulting in improved fuel economy.

BACKGROUND OF THE INVENTION 
In order to conserve energy, automobiles are now being engineered to give 
improved gasoline mileage compared to those in recent years. This effort 
is of great urgency as a result of Federal regulations recently enacted 
which compel auto manufacturers to achieve prescribed gasoline mileage. 
These regulations are to conserve crude oil. In an effort to achieve the 
required mileage, new cars are being down-sized and made much lighter. 
However, there are limits in this approach beyond which the cars will not 
accommodate a typical family. 
Another way to improve fuel mileage is to reduce engine friction. The 
present invention is concerned with this latter approach. 
SUMMARY 
According to the present invention it has been discovered that the 
operating friction of an internal combustion engine can be reduced by 
adding to the lubricating oil or fuel used in such engine a minor amount 
of an aliphatic hydrocarbylsulfonylalkanol or aliphatic 
hydrocarbylsulfinylalkanol. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A preferred embodiment of the invention is a lubricating oil or liquid 
hydrocarbon fuel containing a minor amount sufficient to reduce engine 
friction of an additive selected from the group consisting of oil soluble 
and fuel soluble aliphatic hydrocarbylsulfinylalkanols and aliphatic 
hydrocarbylsulfonylalkanols, said additive having the structure: 
##STR1## 
wherein R.sub.1 is an aliphatic hydrocarbon group containing about 12-36 
carbon atoms, R.sub.2 is a divalent aliphatic hydrocarbon group containing 
1 to about 4 carbon atoms and p is 0 or 1. 
In the above formula R.sub.1 can be straight chain, branched chain, 
primary, secondary, tertiary, saturated, or olefinically unsaturated 
hydrocarbon groups. Examples of suitable groups are n-dodecyl, 
2-ethyldecyl, 1-methylundecyl, 1,1-dimethyldecyl, n-tetradecyl, 
2-butyldecyl, n-hexadecyl, 2-butylhexadecyl, 1-ethyltetradecyl, n-eicosyl, 
1-ethyleicosyl, 1-butyleicosyl, n-docosyl, 1-butyldocosyl, n-triacontyl, 
1-ethyltriacontyl, n-hexatriacontyl, n-dodecenyl, 2-ethyldecenyl, 
1-methylheptadecenyl and the like. Highly preferred groups are hexadecyl 
and octadecyl. 
In one preferred embodiment p is 0, such that the additives are aliphatic 
hydrocarbylsulfinylalkanols. Examples of these additives are: 
2-(dodecylsulfinyl)ethanol 
2-(2-ethyldodecylsulfinyl)ethanol tetradecylsulfinylmethanol 
2-(1-butyldodecylsulfinyl)propanol 
2-(1-ethyloctadecylsulfinyl)butanol 
3-(1-methyldocosylsulfinyl)propanol and the like. 
In this embodiment the more preferred additives are C.sub.16 
hydrocarbylsulfinylalkanols and C.sub.18 hydrocarbylsulfinylalkanols and 
mixtures thereof. Representative examples of these are: 
2-(hexadecylsulfinyl)ethanol 
2-(octadecylsulfinyl)ethanol 
2-(2-ethyltetradecylsulfinyl)propanol 
2-(1-methylheptadecylsulfinyl)ethanol 
2-(1-methylpentadecylsulfinyl)butanol 
and the like. 
In another preferred embodiment p is 1, such that the additives are 
aliphatic hydrocarbylsulfonylalkanols. Representative examples of these 
are: 
2-(dodecylsulfonyl)ethanol 
3-(tetradecylsulfonyl)propanol 
2-(2-ethyldodecylsulfonyl)propanol 
2-(1-methylheptadecylsulfonyl)ethanol 
2-(hexadecenylsulfonyl)propanol 
4-(1-methylheptadecenylsulfonyl)butanol 
2-(eicosylsulfonyl)ethanol 
2-(hexacosylsulfonyl)ethanol 
2-(hexatriacontylsulfonyl)butanol 
and the like. 
In this embodiment the more preferred compounds are C.sub.16 and C.sub.18 
aliphatic hydrocarbylsulfonylalkanols. Representative examples of these 
are: 
2-(hexadecylsulfonyl)ethanol 
2-(1-methylpentadecylsulfonyl)ethanol 
2-(1-methylheptadecylsulfonyl)propanol 
2-(1-hexyldodecylsulfonyl)ethanol 
2-(octadecylsulfonyl)ethanol 
and the like. 
In a highly preferred embodiment R.sub.2 is the group --CH.sub.2 --CH.sub.2 
-- such that the additives are ethanol derivatives. Representative 
examples of these are: 
2-(hexadecylsulfonyl)ethanol 
2-(hexadecenylsulfonyl)ethanol 
2-(1-butyldodecylsulfinyl)ethanol 
2-(1-ethyltetradecylsulfinyl)ethanol 
2-(1-methylheptadecylsulfinyl)ethanol 
2-(1-methylheptadecenylsulfinyl)ethanol 
2-(2-ethylhexadecylsulfonyl)ethanol 
2-(octadecylsulfinyl)ethanol 
The most preferred additives are: 
2-(hexadecylsulfinyl)ethanol 
2-(octadecylsulfinyl)ethanol 
2-(hexadecylsulfonyl)ethanol 
2-(octadecylsulfonyl)ethanol 
The additives are readily made by conventional methods by first making an 
aliphatic hydrocarbylthioalkanol. These can be made by reaction of an 
olefinically unsaturated hydrocarbon with a mercaptoalkanol under uv 
radiation. This is then oxidized with hydrogen peroxide to form the 
sulfinyl or sulfonyl derivative depending upon the degree of oxidation. 
Generally, an equal mole amount of hydrogen peroxide will form the 
sulfinyl derivative and two moles of hydrogen peroxide per mole of 
hydrocarbylthioalkanol will form the sulfonyl derivative. Intermediate 
amounts will form mixtures which are also useful.

The following example illustrates the preparation of representative 
compounds. 
EXAMPLE 1 
Preparation of Hydrocarbylsulfinylalkanols 
In a uv cell was placed 30 grams of a mixture of 50 weight percent 
.alpha.-hexadecene and 50 weight percent .alpha.-octadecene and 10 grams 
of mercaptoethanol. The mixture was stirred 30 minutes under uv radiation 
leaving 40 grams of a mixture of 2-(octadecylthio)ethanol and 
2-(hexadecylthio)ethanol. 
In a second reaction vessel was placed 75 grams of the above mixture, 100 
ml methanol, 3 grams sodium bromide and 5 ml acetic acid. Then 32 grams of 
30% hydrogen peroxide was added dropwise at 45.degree.-50.degree. C. over 
a 30-minute period. The methanol was then distilled off and about 200 ml 
of heptane was added. The heptane was distilled off to remove water. The 
sodium bromide precipitate was then filtered at about 75.degree. C. The 
filtrate was cooled forming a precipitate. This was filtered off to yield 
45 grams of 2-(C.sub.16-18 alkylsulfinyl) ethanol. 
Other similar sulfinyl derivatives can be made following the above general 
procedure by using different aliphatic hydrocarbylthioalkanols. 
EXAMPLE 2 
Preparation of Hydrocarbylsulfonylalkanols 
To a uv cell was added 429 grams of 1-octadecene and 135 grams of 
mercaptoethanol. This mixture was stirred 60 minutes under uv radiation. 
Following this, the unreacted mercaptoethanol was distilled out leaving 
535 grams of 1-octadecylthioethanol. 
In a reaction vessel was placced 450 grams of 1-octadecylthioethanol and 
500 ml methanol. While stirring 309 grams of 30% hydrogen peroxide was 
added dropwise over a 45-minute period at 45.degree.-50.degree. C. The 
mixture was then heated to 70.degree. C. and stirred for one hour. It was 
then vacuum distilled to 100.degree. C. at 30 mm Hg abs to remove methanol 
and water yielding 478 grams of 2-(octadecylsulfonyl)ethanol. 
Other similar sulfonyl derivatives can be made following the above general 
procedure using other aliphatic hydrocarbylthioalkanols. 
The additives are added to lubricating oil in an amount which reduces the 
friction of an engine operating with the oil in the crankcase. A useful 
concentration is about 0.05-3 weight percent. A more preferred range is 
about 0.1-1.5 weight percent. 
From the above it can be seen that the present invention provides an 
improved crankcase lubricating oil. Accordingly, an embodiment of the 
invention is an improved motor oil composition formulated for use as a 
crankcase lubricant in an internal combustion engine wherein the 
improvement comprises including in the crankcase oil an amount sufficient 
to reduce fuel consumption of the engine of an aliphatic 
hydrocarbylsulfinyl or sulfonyl alkanol. 
In a highly preferred embodiment such improved motor oil also contains an 
ashless dispersant, a zinc dialkyldithiophosphonate and an alkaline earth 
metal salt of a petroleum sulfonic acid or an alkaryl sulfonic acid (e.g. 
alkylbenzene sulfonic acid). 
The additives can be used in mineral oil or in synthetic oils of viscosity 
suitable for use in the crankcase of an internal combustion engine. 
Crankcase lubricating oils have a viscosity up to about 80 SUS at 
210.degree. F. According to the present invention the additives function 
to increase fuel economy when added to lubricating oil compositions 
formulated for use in the crankcase of internal combustion engines. 
Similar mileage benefits could be obtained in both spark ignited and 
diesel engines. 
Crankcase lubricating oils of the present invention have a viscosity up to 
about SAE 40. Sometimes such motor oils are given a classification of both 
0.degree. and 210.degree. F., such as SAE 1OW 40 or SAE 5W 30. 
Crankcase lubricants of the present invention can be further identified 
since they usually contain a zinc dihydrocarbyldithiophosphate in addition 
to the present additive. Likewise, these crankcase lubricants contain an 
alkaline earth metal sulfonate such as calcium petroleum sulfonate, 
calcium alkaryl sulfonate, magnesium petroleum sulfonate, magnesium 
alkaryl sulfonate, barium petroleum sulfonate, barium alkaryl sulfonate 
and the like. 
Mineral oils include those of suitable viscosity refined from crude oil 
from all sources including Gulfcoast, midcontinent, Pennsylvania, 
California, Alaska and the like. Various standard refinery operations can 
be used in processing the mineral oil. 
Synthetic oil includes both hydrocarbon synthetic oil and synthetic esters. 
Useful synthetic hydrocarbon oils include liquid polymers of 
.alpha.-olefins having the proper viscosity. Especially useful are the 
hydrogenated liquid oligomers of C.sub.6-12 .alpha.-olefins such as 
.alpha.-decene trimer. Likewise, alkylbenzenes of proper viscosity can be 
used, such as didodecylbenzene. 
Useful synthetic esters include the esters of both monocarboxylic acid and 
polycarboxylic acid as well as monohydroxy alkanols and polyols. Typical 
examples are didodecyl adipate, trimethylol propane tripelargonate, 
pentaerythritol tetracaproate, di-(2-ethylhexyl)adipate, dilauryl sebacate 
and the like. Complex esters prepared from mixtures of mono- and 
dicarboxylic acid and mono- and polyhydroxyl alkanols can also be used. 
Blends of mineral oil with synthetic oil are particularly useful. For 
example, blends of 10-25 weight percent hydrogenated .alpha.-decene trimer 
with 75-90 weight percent 150 SUS (100.degree. F.) mineral oil results in 
an excellent lubricant. Likewise, blends of about 10-25 weight percent 
di-(2-ethylhexyl)adipate with mineral oil of proper viscosity results in a 
superior lubricating oil. Also blends of synthetic hydrocarbon oil with 
synthetic esters can be used. Blends of mineral oil with synthetic oil are 
especially useful when preparing low viscosity oil (e.g. SAE 5W 20) since 
they permit these low viscosities without contributing excessive 
volatility. 
The more preferred lubricating oil composition includes zinc 
dihydrocarbyldithiophosphate (ZDDP) in combination with the present 
additives. Both zinc dialkyldithiophosphates and zinc 
dialkaryldithiophosphates as well as mixed alkyl-aryl ZDDP are useful. A 
typical alkyl-type ZDDP contains a mixture of isobutyl and isoamyl groups. 
Zinc dinonylphenyldithiophosphate is a typical aryl-type ZDDP. Good 
results are achieved using sufficient ZDDP to provide about 0.01-0.5 
weight percent zinc. A preferred concentration supplies about 0.05-0.3 
weight percent zinc. 
Another additive used in the oil compositions are the alkaline earth metal 
petroleum sulfonates or alkaline earth metal alkaryl sulfonates. Examples 
of these are calcium petroleum sulfonates, magnesium petroleum sulfonates, 
barium alkaryl sulfonates, calcium alkaryl sulfonates or magnesium alkaryl 
sulfonates. Both the neutral and the overbased sulfonates having base 
numbers up to about 400 can be beneficially used. These are used in an 
amount to provide about 0.05-1.5 weight percent alkaline earth metal and 
more preferably about 0.1-1.0 weight percent. In a most preferred 
embodiment the lubricating oil composition contains a calcium petroleum 
sulfonate or alkaryl (e.g. alkylbenzene) sulfonate. 
Viscosity index improvers can be included such as the polyalkylmethacrylate 
type or the ethylene-propylene copolymer type. Likewise, styrene-diene VI 
improvers or styrene-acrylate copolymers can be used. Alkaline earth metal 
salts of phosphosulfurized polyisobutylene are useful. 
Most preferred crankcase oils also contain an ashless dispersant such as 
the polyolefin-substituted succinamides and succinimides of polyethylene 
polyamines such as tetraethylenepentamine. The polyolefin succinic 
substituent is preferably a polyisobutene group having a molecular weight 
of from about 800 to 5,000. Such ashless dispersants are more fully 
described in U.S. Pat. Nos. 3,172,892 and 3,219,666 incorporated herein by 
reference. 
Another useful class of ashless dispersants are the polyolefin succinic 
esters of mono- and polyhydroxy alcohols containing 1 to about 40 carbon 
atoms. Such dispersants are described in U.S. Pat. Nos. 3,381,022 and 
3,522,179. 
Likewise, mixed ester/amides of polyolefin substituted succinic acid made 
using alkanols, amines and/or aminoalkanols represent a useful class of 
ashless dispersants. 
The succinic amide, imide and/or ester type ashless dispersants may be 
boronated by reaction with a boron compound such as boric acid. Likewise 
the succinic amide, imide, and/or ester may be oxyalkylated by reaction 
with an alkylene oxide such as ethylene oxide or propylene oxide. 
Other useful ashless dispersants include the Mannich condensation products 
of polyolefin-substituted phenols, formaldehyde and polyethylene 
polyamine. Preferably, the polyolefin phenol is a 
polyisobutylene-substituted phenol in which the polyisobutylene group has 
a molecular weight of from about 800 to 5,000. The preferred polyethylene 
polyamine is tetraethylene pentamine. Such Mannich ashless dispersants are 
more fully described in U.S. Pat. Nos. 3,368,972; 3,413,347; 3,442,808; 
3,448,047; 3,539,633; 3,591,598; 3,600,372; 3,634,515; 3,697,574; 
3,703,536; 3,704,308; 3,725,480; 3,726,882; 3,736,357; 3,751,365; 
3,756,953; 3,793,202; 3,798,165; 3,798,247 and 3,803,039. 
The above Mannich dispersants can be reacted with boric acid to form 
boronated dispersants having improved corrosion properties. 
Superior results are obtained by using the aliphatic 
hydrocarbylsulfinylalkanols and aliphatic hydrocarbylsulfonylalkanols in 
lubricating oil in combination with a phosphonate additive. Preferred 
phosphonates are the di-C.sub.1-4 alkyl C.sub.12-36 alkyl or alkenyl 
phosphonates. These compounds have the structure: 
##STR2## 
wherein R.sub.3 is an aliphatic hydrocarbon group containing about 12-36 
carbon atoms and R.sub.4 and R.sub.5 are independently selected from lower 
alkyl groups containing about 1-4 carbon atoms. Representative examples of 
these synergistic coadditives are: 
dimethyl octadecylphosphonate 
dimethyl octadecenylphosphonate 
diethyl 2-ethyldecylphosphonate 
ethyl propyl 1-butylhexadecylphosphonate 
methyl ethyl octadecylphosphonate 
methyl butyl eicosylphosphonate 
dimethyl hexatriacontylphosphonate 
When using the phosphonate coadditive only a small synergistic amount is 
required. A useful range is about 0.005-0.75 weight percent based on the 
formulated oil. A more preferred amount is about 0.05-0.5 weight percent. 
The friction reducing additives of this invention are also useful in fuel 
compositions. Fuel injected or inducted into a combustion chamber wets the 
walls of the cylinder. Fuels containing a small amount of the present 
additive reduce the friction due to the piston rings sliding against the 
cylinder wall. 
The additives can be used in both diesel fuel and gasoline used to operate 
internal combustion engines. Fuels containing about 0.001-0.25 weight 
percent of the sulfonyl or sulfinyl derivatives can be used. 
Fuels used with the invention can contain any of the additives 
conventionally added to such fuels. In the case of gasoline it can include 
dyes, antioxidants, detergents, antiknocks (e.g. tetraethyllead, 
methylcyclopentadienylmanganese tricarbonyl, rare earth metal chelates, 
methyl tert-butylether and the like). In the case of diesel fuels the 
compositions can include pour point depressants, detergents, ignition 
improvers (e.g. hexylnitrate) and the like. 
Tests were conducted which demonstrated the friction reducing properties of 
the present invention. 
LFW-1 Test 
In this test a metal cylinder is rotated around its axis 45.degree. in one 
direction and then 45.degree. in the opposite direction at a rate of 120 
cycles per minute. A metal block curved to conform to the circular contour 
of the cylinder presses at a fixed load against the periphery of the 
cylinder. Test lubricant is applied to the rubbing surface between the 
cylinder and the block. Torque transmitted to the block from the 
oscillating cylinder is measured. The greater the torque the greater the 
friction. Results are given in terms of "percent improvement" which is the 
percent reduction in torque compared to that obtained with the test oil 
without the test additive. 
SAE-2 Fly Wheel Test 
In this test a heavy fly wheel is rotated at 1440 rpm. A series of 9 clutch 
plates are then brought to bear axially at a defined load against the fly 
wheel. The fly wheel is connected to the rotating plate. The static plates 
are connected to a device which measures rotational torque. The time from 
initially applying pressure through the clutch plate until the rotating 
plates stop rotating is measured. Also, the rotational torque measured at 
the static plates is plotted against time. Torque rises to a value 
preferred to as "dynamic torque" and then rises to a maximum called 
"static torque" as the plates stop rotation. The clutch plates are 
immersed in test lubricant. A reduction in friction is indicated by (1) an 
increase in time required to stop the rotation of the moving plates and 
(2) a decrease in dynamic and static torque. Results are reported in 
percent time increase (percent improvement) and percent reduction in 
torque compared to that obtained using the same oil without the test 
additive. 
The test oil is a fully formulated oil of SAE SE quality. Test results are 
given in the following table: 
______________________________________ 
SAE No. 2 
LFW-1 % Improvement 
% Improve- Time 
Additive ment Increase Dyn. Static 
______________________________________ 
C.sub.16-18 alkyl- 
sulfinyl- 
ethanol 
(0.15%) 14 9 14 39 
C.sub.16-18 alkyl- 
sulfinyl- 
ethanol 
(0.15%) plus 
dimethyl octa- 
decyl- 
phosphonate 
(0.2%) 20 -- -- -- 
C.sub.16-18 alkyl- 
sulfonyl- 
ethanol 
(0.3%) 11 10 13 38 
C.sub.16-18 alkyl- 
sulfonyl- 
ethanol 
(0.3%) plus 
dimethyl octa- 
decyl- 
phosphonate 
(0.2%) 14 14 17 35 
Dimethyl octa- 
decyl- 
phosphonate 
(0.3%) 11 8.8 13.7 30.3 
Dimethyl octa- 
decyl- 
phosphonate 
(0.5%) 11.5 9.9 16.1 40.9 
______________________________________ 
The above results show that both the sulfinyl and sulfonyl additives are 
very effective in reducing friction and that their effectiveness is 
improved by use in combination with a phosphonate.