Automotive friction reducing composition

A friction reducing additive for addition to the lubricating oil crankcase of an internal combustion engine, such as in an automobile, is provided. The additive comprises (a) a hydrocarbon oil of lubricating viscosity; (b) an extreme pressure antiwear agent comprising: (i) an oil dispersion of solid inorganic film-forming potassium borate, (ii) antimony diaklylphosphorodithioate, and (iii) a liquid chlorinated paraffin; (c) an alkaline material; and (d) a viscosity index improver. The preferred additive composition of the present invention also contains an antioxidant and an antifoaming agent.

TECHNICAL FIELD 
The present invention relates to a novel lubricating composition for use in 
oil lubricated internal combustion engines. More particularly, the present 
invention relates to a friction and wear reducing additive which can be 
added directly to an engine crankcase. 
BACKGROUND OF THE INVENTION 
Lubricating oils for use in internal combustion engines such as those in 
the automobile are normally formulated with various additives to improve 
their properties under engine operating conditions. While commercially 
available motor oils of both petroleum and synthetic origin provide good 
lubrication for the metal parts of an internal combustion engine, it has 
long been recognized that friction and wear properties of these motor oils 
have not been optimized. Accordingly, the art has developed a number of 
products which can be added directly to the oil in the crankcase by the 
ultimate consumer. These crankcase additives are said to reduce friction 
and to provide improved engine wear characteristics to the base motor oil. 
As a practical matter, however, many of the commercially available 
crankcase additives do not significantly improve motor oil performance and 
in some cases may actually reduce the performance characteristics of the 
base motor oil to which they are added. Thus, there is a significant need 
for a friction reducing additive which can be added directly to motor oil 
in the crankcase to improve performance characteristics without 
introducing any of the deleterious effects caused by the prior art 
crankcase additives. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to provide a friction 
reducing crankcase additive imparting improved performance characteristics 
to any base motor oil while not adversely affecting the performance of 
this oil. 
More specifically, it is an object of the present invention to provide an 
automotive friction reducing additive which will reduce wear on primary 
metal-to-metal surfaces and therefore increase engine life. 
It is another object of the present invention to provide an automotive 
friction reducing additive which will significantly increase fuel mileage 
in an automotive engine. 
A further object of the present invention is to provide an automotive 
friction reducing additive which results in reduced engine temperature 
during operation. 
Moreover, it is an object of the present invention to provide an automotive 
friction reducing additive which results in increased engine performance 
and reduced engine noise and roughness. 
It is another object of the present invention to provide an automotive 
friction reducing additive which prevents acid and water corrosion of 
metal surfaces in the automotive engine. 
These and other objects which will be readily apparent to one of ordinary 
skill in the art are achieved by providing a friction reducing additive 
composition which comprises (a) a hydrocarbon oil of lubricating 
viscosity; (b) an extreme pressure antiwear agent comprising a mixture of 
(i) an oil dispersion of solid, film-forming potassium borate, (ii) 
antimony dialkylphosphorodithioate, (iii) liquid chlorinated paraffin; (c) 
an alkaline additive; and (d) a viscosity index improver. The preferred 
additive composition of the present invention also contains an antioxidant 
and an antifoaming agent. The additive composition of the present 
invention is preferably added at a level of about 3 to 12 percent by 
volume to five quarts of engine oil. 
DETAILED DESCRIPTION OF THE INVENTION 
The friction reducing additive composition of the present invention is 
unique in that it is specially formulated to treat the metal surfaces in 
the engine rather than simply the oil itself. Accordingly, the increased 
friction reducing properties of the additive according to the present 
invention remain even after the oil in the crankcase is changed. As 
described in more detail later, the friction reducing additive of the 
present invention significantly enhances the performance characteristics 
of motor oil and surpasses commercially available crankcase additives in a 
significant number of performance categories. The additive of this 
invention can be used in any oil lubricated internal combustion engine 
(e.g., gasoline or diesel), including by way of example only, engines in 
automobiles, trucks, airplanes, boats, motorcycles, lawn mowers, chain 
saws and the like. The preferred utility is for use as a crankcase 
additive for automotive engines. 
The friction reducing additive of the present invention comprises as its 
essential components a hydrocarbon oil of lubricating viscosity, a 
specific multi-component extreme pressure antiwear additive, an alkaline 
additive, and a viscosity index improver. Also preferably incorporated 
into this additive composition are an antioxidant and an antifoam agent. 
The additive of the present invention is added to the motor oil in an 
amount sufficient to provide the desired friction reducing characteristics 
depending on the nature of the engine, the base motor oil and intended 
operating conditions. In general, the additive can comprise from about 3 
to about 12 percent by volume of the oil/additive mixture, with the 
preferred additive level being from about 5 to 10 percent by volume. Most 
preferred is an additive level of about 7 percent by volume. 
A convenient manner to supply this additive for automotive use is in a 12 
ounce container, which when added to 4 to 5 quarts of engine oil, provides 
the requisite additive amounts. 
The hydrocarbon oil of lubrication viscosity employed as the base for the 
additive of the present invention may be of paraffinic or naphthenic base 
as well as synthetic bases. The preferred oils are solvent neutral oils 
which are commercially available and comprise a premium quality, highly 
refined paraffinic base oil generally having a viscosity level between 62 
and 650 SUS at 100.degree. F. Preferred are solvent neutral oils having a 
viscosity in the range of about 100 to 200 SUS at 100.degree. F. with the 
most preferred being an oil having a viscosity having about 150 SUS at 
100.degree. F. One such oil is available from Sun Petroleum Products 
Company of Tulsa, Okla., under the grade designation SN150. In general, 
the solvent neutral oil component can comprise from about 20 to about 65 
percent by volume of the additive product. Preferred are oil levels of 
from about 30 to about 55 percent by volume, with the most preferred level 
being about 50 percent by volume. When this additive is added to a base 
motor oil the level of solvent neutral oil can range in general from about 
1.4 to about 5.0 percent by volume. The preferred solvent neutral oil 
level in the crankcase product is from about 2.1 to about 4.0 percent by 
volume, with the most preferred level being about 3.5 percent by volume. 
The second major ingredient of the friction reducing additive composition 
of the present invention is an extreme pressure antiwear agent which 
comprises three specific components. Applicant has found that the 
combination of these three components results in a product superior to 
prior art lubricating composition containing one or more of these 
components. 
The first of the extreme pressure antiwear components used according to the 
present invention is a borate additive. This additive is available as a 
borate lubricating oil additive in the form of an oil dispersion of small 
amorphous inorganic borate spheres averaging about 0.1 micrometers in 
diameter. The preferred form of this product is essentially potassium 
borate and is available from Chevron Chemical Company of San Francisco, 
Calif., as OLOA 9750. This additive has both exceptional stability and 
load carrying capacity. The microspheres interact with metal load bearing 
surfaces to form a film of extraordinary resilience under extreme pressure 
conditions. This borate additive has many advantages over traditional 
solid film-forming additives such as graphite and molybdenum disulfide, 
i.e., increased EP protection at lower viscosity, excellent thermal and 
oxidative stability, high temperature non-corrosivity, good elastomer 
compatability, and no sulfur odor. In general, the borate component can 
comprise from about 2 to about 25 percent by volume of the additive 
product. Preferred borate levels are from about 10 to about 15 percent by 
volume, with the most preferred level being about 12.5 percent by volume. 
The additive-containing motor oil according to the present invention can 
comprise from about 0.14 to about 1.8 percent by volume of the borate 
component. The preferred level of borate in the oil is from about 0.7 to 
about 1.1 percent by volume, with the most preferred level being about 0.9 
percent by volume. 
The second extreme pressure antiwear component employed according to the 
present invention is antimony dialkylphosphorodithioate, which has the 
following formula: 
##STR1## 
This material is commercially available from a number of sources including 
the R. T. Vanderbilt Company, Inc., of Norwalk, Conn. as VANLUBE.RTM. 622. 
In general, the antimony dialkylphosphorodithioate component can comprise 
from about 1 to about 20 percent by volume of the additive product. 
Preferred levels of this component are from about 5 to about 10 percent by 
volume, with the most preferred level being about 6.2 percent by volume. 
The additive-containing motor oil according to the present invention can 
comprise from about 0.07 to about 1.4 percent by volume of this component. 
The preferred level in the oil is from about 0.3 to about 0.7 percent by 
volume, with the most preferred level being about 0.4 percent by volume. 
The third extreme pressure antiwear component employed in the composition 
of the present invention is a liquid chlorinated paraffin. Preferred are 
paraffin materials having a chlorine content between about 39 and 70 
percent by weight and a viscosity between 450 and 70,000 SUS at 
100.degree. F. Such a product is available from Diamond Shamrock of 
Cleveland, Ohio as CHLOROWAX.RTM. 42-170. In general, the chlorinated 
paraffin component can comprise from about 2 to about 35 percent by volume 
of the additive product. Preferred paraffin levels are from about 10 to 
about 20 percent by volume, with the most preferred level being about 12.5 
percent by volume. The additive-containing motor oil according to the 
present invention can comprise from about 0.14 to about 2.5 percent by 
volume of the chlorinated paraffin component. The preferred level of this 
component in the oil is from about 0.7 to about 1.4 percent by volume, 
with the most preferred level being about 0.9 percent by volume. 
The next major ingredient of the composition of the present invention is an 
alkaline additive. This alkaline material performs the function of 
neutralizing acidic components generated during engine operation, and is 
especially important due to the acidity created by the liquid chlorinated 
paraffin in the composition of the present invention. Any of the commonly 
employed alkaline oil additives may be employed as this ingredient. 
Examples of such additives include calcium sulfonate, overbased calcium 
sulfonate, barium sulfonate, overbased barium sulfonate, overbased 
magnesium sulfate, barium phosphonate, calcium phenate and the like. In 
general, these alkaline materials can have a total base number (TBN) 
between about 10 and 400 with the preferred materials having a TBN in the 
range of about 200 to 350. The most preferred ingredient is an overbased 
calcium sulfonate having a TBN of about 300 such as the product known as 
LUBRIZOL.RTM. 74 available from Lubrizol Corp., Wickliffe, Ohio. In 
general, the alkaline component can comprise from about 0.4 to about 20 
percent by volume of the additive product. Preferred alkaline levels are 
from about 2 to about 10 percent by volume, with the most preferred level 
being about 4.2 percent by volume. The additive-containing motor oil 
according to the present invention can comprise from about 0.03 to about 
1.4 percent by volume of the alkaline component. The preferred level of 
this component in the oil is from about 0.14 to about 0.7 percent by 
volume, with the most preferred level being about 0.3 percent by volume. 
The fourth major ingredient of the composition of the present invention is 
a viscosity index improver. This material should have a viscosity level 
between about 480 and 1600 cSt at 100.degree. C. and preferably has a 
viscosity in the range of about 1015 and 1250 cSt at 100.degree. C., with 
the most preferred viscosity level being at about 1150 cSt at 100.degree. 
C. Among the viscosity index improvers which can be employed are olefin 
copolymers, polyisobutylene, methacrylic copolymers, polymethacrylate, 
methacrylate terpolymers, and polybutenes. The preferred viscosity index 
improver for use according to the present invention is an olefin copolymer 
such as the one designated TLA-347A available from the Texaco Chemical 
Company, Houston, Tex. In general, the olefin copolymer component can 
comprise from about 4 to about 35 percent by volume of the additive 
product. Preferred olefin copolymer levels are from about 10 to about 25 
percent by volume, with the most preferred level being about 12.5 percent 
by volume. The additive-containing motor oil according to the present 
invention can comprise from about 0.3 to about 2.5 percent by volume of 
the olefin copolymer component. The preferred level of this component in 
the oil is from about 0.7 to about 1.8 percent by volume, with the most 
preferred level being about 0.9 percent by volume. 
A preferred optional ingredient employed according to the composition of 
the present invention is an antioxidant additive. Any of the known classes 
of antioxidant additives may be employed as long as they are otherwise 
compatible with the components in the composition of the present 
invention. Among these antioxidants are various aryl amines such as 
alkylated diphenylamines, including octylated and nonylated diphenylamines 
(e.g., p,p'-dioctyldiphenylamine and dinonyldiphenylamine); 
dithiocarbamate derivatives such as zinc diamyldithiocarbamate and 
4,4'-methylene bis(dibutyldithiocarbamate); blends of substituted 
diphenylamines and zinc dithiocarbamate; 2,6-di-t-butyl-p-cresol; 
polymerized 1,2-dihydro-2,2,4-trimethylquinoline; 4,4'-methylene 
bis(2,6-di-t-butylphenol); sulfur-phosphorus type antioxidants and the 
like. Preferred are amine antioxidants such as aryl amines, alkylated 
diphenylamines, octylated diphenylamines, and monoalkene thiophosphonates. 
The preferred amine antioxidant has a nitrogen content between about 1 to 
about 5 percent by weight and preferably with the range of 2.2 to 4.2 
percent by weight. One preferred antioxidant is an aryl amine such as that 
available from Lubrizol Corporation of Wickliffe, Ohio, as Lubrizol 5150A. 
Another suitable amine antioxidant is sold under the name of VANLUBE.RTM. 
NA by the R. T. Vanderbilt Company of Norwalk, Conn. (an alkylated 
diphenylamine). In general, the antioxidant component can comprise from 
about 0 to about 20 percent by volume of the additive product. Preferred 
antioxidant levels are from about 1 to about 10 percent by volume, with 
the most preferred level being about 2.1 percent by volume. The 
additive-containing motor oil according to the present invention can 
comprise from about 0 to about 1.4 percent by volume of the antioxidant 
component. The preferred level of this component in the oil is from about 
0.07 to about 0.7 percent by volume, with the most preferred level being 
about 0.2 percent by volume. 
The composition of the present invention also preferably contains an 
antifoaming agent. Preferred are silicone based antifoaming materials such 
as Dow Corning.RTM. 200 FLUID available from Dow Corning Corp. of Midland, 
Mich., which is a dimethyl siloxane polymer. These antifoaming agents are 
preferably employed at conventional levels, e.g., about 20 ppm in the 
additive composition of the present invention. 
Another suitable defoamant is sold under the name of Mobilad.RTM. C-402 by 
the Mobil Chemical Company of Edison, N.J., which is a solution of 
polymeric defoamant containing no silicones. The recommended treating 
levels are between 500-1,000 ppm, or 500 ppm of Mobilad.RTM. C-402 mixed 
with a silicone defoamant like Dow Corning.RTM. 200 FLUID at half the 
recommended silicone treat rate. Other antifoaming agents, of course, 
could be employed. 
The automotive friction reducing composition of the present invention is 
prepared by blending the above-described components at an elevated 
temperature. In general, the preferred method of the present invention 
comprises blending the solvent neutral oil, the potassium borate, the 
antimony dialkylphosphorodithioate, the liquid chlorinated paraffin and 
the olefin copolymer at an elevated temperature not exceeding about 
150.degree. F. and preferably not exceeding about 135.degree. to about 
140.degree. F. The mixture is then cooled to a temperature in the range of 
from about 90.degree. to about 100.degree. F. after which the optional 
antioxidant, the alkaline additive and the antifoaming agent are added. In 
the most preferred method, the solvent neutral oil is heated to a 
temperature in the range of about 100.degree. to 110.degree. F. The 
potassium borate is then blended into the heated oil while maintaining the 
temprature at about 105.degree. to 115.degree. F. The mixture is then 
heated to about 110.degree. to 125.degree. F. and the antimony 
dialkylphosphorodithioate is blended into the mixture. After heating to a 
temperature of about 120.degree. to 130.degree. F. the liquid chlorinated 
paraffin is blended into the mixture. The mixture is then heated to a 
temperature in the range of about 130.degree. to 140.degree. F. and the 
olefin copolymer is added. The resulting mixture is then cooled to a 
temperature in the range of from about 90.degree. to about 100.degree. F. 
and the remaining components are blended into the mixture. 
The friction reducing additive composition of the present invention imparts 
significantly improved performance characteristics to automotive engine 
oil. Specifically, the product of the present invention exhibits lower 
carbon residue, good copper corrosion, exceptional extreme pressure wear 
prevention characteristics, and good coefficient of friction properties. 
As a result of these characteristics, use of the composition of the 
present invention as an additive to an automotive engine crankcase results 
in increased gas mileage, reduced engine operating temperatures, reduced 
wear on the primary metal-to-metal surfaces and increased engine life. 
The following examples are intended to illustrate more fully the nature of 
the present invention without acting as a limitation on its scope.

EXAMPLE 1 
This example demonstrates the preparation of a 12 ounce additive 
composition according to the present invention. The following ingredients 
in the amounts shown were combined with stirring in the order listed at 
the elevated temperatures shown: 
______________________________________ 
Ingredient Amount Temperature 
______________________________________ 
Solvent neutral oil 6 ozs. 100-110.degree. F. 
Potassium Borate (EP Additive) 
1.5 ozs. 105-115.degree. F. 
Antimony Dialkylphosphorodithioate 
0.75 ozs. 
110-125.degree. F. 
(EP Additive) 
Liquid Chlorinated Paraffin 
1.5 ozs. 120-130.degree. F. 
(EP Additive) 
Olefin Copolymer (VI Improver) 
1.5 ozs. 130-140.degree. F. 
Aryl Amine (Antioxidant) 
.25 ozs. 90-100.degree. F. 
Overbased Calcium Sulfonate 
0.5 ozs. 90-100.degree. F. 
Silicone Antifoamant 
20 ppm 90-100.degree. F. 
______________________________________ 
The resulting product is stable for long periods of time. 
EXAMPLE 2 
This example demonstrates the preparation and the use of oil lubricating 
composition of the present invention. Twelve ounces of the composition of 
Example 1 was added to a standard motor oil (Quaker State) to give a 
composition of 5 quarts (160 oz.). This composition was subjected to the 
following standard performance tests: 
Carbon Residue (Ramsbottom) ASTM D-524 
Copper Corrosion ASTM D-130 
Extreme Pressure Properties of Lubricating Fluids (Four-Ball Method) ASTM 
D-2783 (Weld and Load Wear Index) 
Wear Preventive Characteristics of Lubricants ASTM D-2266 (Scar Diameter). 
The additive-containing composition of the present invention was tested 
against a number of commercially available friction reducing additives and 
unmodified motor oils. The results of these tests are set out in Table 1. 
It can be seen that the product according to the present invention 
possesses superior overall performance characteristics. 
While certain specific embodiments of the invention have been described 
with particularity herein, it will be recognized that various 
modifications thereof will occur to those skilled in the art. Therefore, 
the scope of the invention is to be limited solely by the scope of the 
appended claims. 
TABLE 1 
______________________________________ 
EP 
Properties 
Carbon (Four Ball 
Coefficient 
Residue Weld & of Friction 
(Rams- Copper Load (Four Ball 
Product bottom) Corr. Index) Scar. Dia.) 
______________________________________ 
*Present Invention 
1.19% 1A 315 0.39 mm 
63.46 
**WYNNS Friction 
1.28% 1A 200 0.50 mm 
proofing 44.10 
**BARDAHL Oil 
1.29% 1A 200 0.47 mm 
Treatment 2 35.05 
**STP Oil 1.22% 1A 200 0.45 mm 
Treatment 44.45 
***SLICK 50 2.14% 1A 200 0.45 mm 
TFE Resin 39.55 
Engine Coating 
****TMT 1.35% 1A 200 0.46 mm 
Fluorocarbon 34.82 
Resin 
****FR III 1.30% 1A 200 0.44 mm 
Friction Reducer 42.26 
**MPG PLUS 2.02% 1A 200 0.55 mm 
41.26 
**CD-2 1.20% 1A 200 0.46 mm 
Oil Treatment 41.73 
**CASITE 1.18% 1A 200 0.43 mm 
Motor Honey 42.21 
Oil Treatment 
*****PENNZOIL 
1.50% 1A 200 0.53 mm 
45.20 
*****QUAKER 1.42% 3A 200 0.44 mm 
STATE 34.85 
______________________________________ 
*7.5% Product in Quaker State Motor Oil 
**10% Product in Pennzoil 
***20% Product in Pennzoil 
****5% Product in Pennzoil 
*****100% Oil