US3235494A - Two-cycle engine lubricating composition - Google Patents

Description

United States Patent 3,235,494 TWO-CYCLE ENGINE LUBRICATING COMPDSITION Joseph H. Piatt, Oakmont, and Charles E. Trautman,

Cheswick, Pa, assignors to Gulf Research 81 Development Company, Pittsburgh, Pa, a corporation of Delaware No Drawing. Filed Apr. 25, 1963, Ser. No. 275,533

6 Claims. (Cl. 25233) This invention relates to the lubrication of two-cycle engines, and more particularly to lubricating compositions having characteristics which suit them for use in the lubrication of two-cycle gasoline engines.

Two-cycle gasoline engines are becoming increasingly popular, their chief use being to power small electric generators, lawn mowers, cultivators, chain saws, marine outboard motors, and the like. The chief identifying characteristic of a two-cycle gasoline engine is the absence of an independent engine lubricating system. Lubrication of a two-cycle gasoline engine is accomplished by employing an oil-gasoline mixture which functions not only as a lubricant but also as a fuel for the engine.

Inasmuch as the lubricating oil is admixed with the gasoline to form an oil-gasoline mixture for use in a twocycle engine, the lubricating oil must be one which when admixed with the gasoline does not adversely affect the operation of the engine. Thus, for example, the oil-gasoline mixture should give prolonged performance Without giving rise to spark plug fouling, ring sticking, excessive combustion chamber deposits, piston or cylinder wall scufiing, scuffing or spalling of bearings, rusting or corrosion of engine parts, preignition, and the like. While the enumerated undesirable characteristics can result from the gasoline component of the oil-gasoline mixture, they also can result from the lubricating oil component of the mixture. For example, in some instances excessive combustion chamber deposits, spark plug fouling and preignition can be traced to the gasoline, particularly, if the gasoline is leaded. For this reason, some manufacturers of two-cycle engines have recommended the use of unleaded gasoline. In other instances, combustion chamber deposits, spark plug fouling, corrosion, scufling and/or spalling of bearings can be traced to the lubricating oil, particularly if the lubricating oil contains additives. For this reason, some manufacturers of two-cycle engines have recommended the use of straight petroleum oils containing no additives. Uncompounded petroleum oils, however, do not satisfy all the requirements in lubricating twocycle engines.

The present invention provides a lubricating oil composition for use in the lubrication of a two-cycle gasoline engine, said lubricating oil composition, when added either to a leaded or unleaded gasoline, giving increased spark plug life, minimum ring sticking, a cleaner combustion chamber, less scufiing or spalling of bearings and cylinder Walls, less engine corrosion, and freedom from rusting and preignition.

According to the present invention, a lubricating composition for a two-cycle gasoline engine consists essentially of a major amount of a mineral lubricating oil and minor amounts of (1) a highly basic oil-dispersible magnesium complex and (2) an ester having from 12 to 30 carbon atoms in the molecule formed from an aliphatic monohydric alcohol having from 1 to 18 carbon atoms and a fatty acid having from to 24 carbon atoms.

The mineral lubricating oil employed in the composition of the invention is advantageously a highly refined parafiinic oil. By the term highly refined parafiinic oil, we mean a petroleum lubricating oil which has been refined by one of the more drastic refining methods known in the art, for example, by conventional aluminum chloice ride refining or by solvent extraction adapted to remove all or substantially all of the unstable constituents of the oil. An aluminum chloride refined and/ or a solvent extracted parafiinic base oil, such as Pennsylvania oil, provides an excellent base oil for the composition of the invention. However, drastically refined Mid-Continent and Gulf Coastal oils can also be used.

In order to provide a two-cycle engine lubricating composition having maximum lubricating characteristics, we preferably employ a blend of oils as the lubricating oil base. A particularly effective lubricating oil base for use in the composition of the invention is a blend of oils consisting essentially of a major proportion of a parafiinic mineral oil distillate having a viscosity of about 400 to about 500 SUS at 100 F. and a minor proportion of a bright stock having a viscosity of about 2500 to about 4500 SUS at 100 F. The amounts of the paraflinic mineral oil distillate and the bright stock are adjusted so that the viscosity of the lubricating oil blend is about 600 to about 800 SUS at 100 F. In general, the blend comprises about 65 to about percent by weight of the less viscous mineral oil distillate and about 15 to about 35 percent by weight of the more viscous bright stock. Bright stock is obtained by dewaxing and clay treating the residue remaining after vacuum distilling a mineral oil. The lubricating oil base comprises about 92 to about 99 percent by weight of the lubricating composition of the invention.

The highly basic oil-dispersible magnesium complex which is employed in the composition of the invention is characterized in that it is highly basic and possesses a total base number of about 100 to about 400. Highly basic complexes having a total base number of about 250 to about 350 are preferred. The total base number (TBN) is determined by standard potentiometric methods in accordance with ASTM test method D664. Moreover, the magnesium content of the additive is significantly greater than that produced by the presence of magnesium chemically combined as magnesium sulfonate. Generally, the additives contain an amount of magnesium which is from about 5 to 20 times greater than that produced by the presence of magnesium chemically combined as neutral magnesium sulfonate. The magnesium additive is usually prepared in the form of a concentrate in a mineral oil. A typical inspection of such a concentrate suitable for use in the invention is as follows:

Magnesium sulfonate percent 30.6 Magesium do 7.53 Carbon dioxide do 10.20 Specific gravity 1.10 Pour point, F. +10 Base number ASTM D664 301 Sulfated ash ASTM D8l0 38.1

*Equivalent to 10.8 times the amount of magnesium chemically combined as neutral magnesium sulfonate based on sulfonic acid present.

Inasmuch as highly basic magnesium complexes are available commcrcially, the complexes, per se, do not constitute a portion of the invention.

The highly basic magnesium complexes can be prepared according to any of the methods known in the art. These complexes, for example, can be prepared by treating a conventional magnesium sulfion-ate with magnesia and carbon dioxide. According to one method which is described in U.S. Patent No. 2,895,913 which issued on July 21, 1959, to R. L. Carlyle and E. F. Morris, a basic magnesium complex is prepared by (a) reacting magnesinm with an excess of an alkanol containing less than six carbon atoms to form an alkanol insoluble magnesium alkoxide; (b) forming an alkanol soluble magnesium alkoxide-carbon dioxide complex by passing carbon dioxide through the magnesium alkoxide-alk-anol mixture until the same is acid to alpha-naphthol benzein indicator; reacting an excess of the alkanol soluble magnesium alkoxide-carbon dioxide complex with an oil-soluble organic sulfonate in a hydrocarbon oil reaction medium and in the presence of sufficient water to form a homogeneous system. Alternately, the corresponding sulfonic acids can be employed in place of the oil-soluble sulfonate for reaction with the magnesium alkoxide-carbon dioxide complex; (d) condensing from said homogeneous system an oil insoluble magnesium compound in particles the diameter of which are less than 0.25 micron by heating said system whereby said alkanol is removed and said complex is decomposed.

The above steps (b) and (c) may be interchanged if desired, in which case the reaction mixture of magnesium and alkanol may be reacted with the oil-soluble sulfonate and the reaction mixture treated with carbon dioxide.

The oil-soluble sulfonates (or the corresponding sulfonic acids) which are reacted with the magnesium alkoxide-carbon dioxide complex include the salts of the wellknown petroleum mahogany SllllfOI'llC acids which are usually produced by the sulfonation of petroleum lubricating oil distillates with concentrated to fuming sulfuric acid, and which mahogany acids remain in the oil after settling out the acid sludge. These sulfonic acids may be represented by the formula: RSO H, wherein R is usually a naphthenyl, alkylnaphthenyl, alkaryl or naphthenylaryl radical of a weight such that RSO H generally has a molecular weight of from about 350 to 1000. Instead of the petroleum mahogany acids, synthetic oil-soluble alkyl or alkaryl sulfonates can be employed. The alkyl sulfonates require about 24 carbon atoms for oil-solubility, whereas, the alkaryl sulfonates require an alkyl portion containing only about 18 carbon atoms. Suitable oil-soluble synthetic sulfonates include: monoalkyl benzene, and dialkyl benzene sulfonates such as dodecylbenzene sul-fonate, polydodecylbenzene sulfonates, diwax benzene sulfonates, diwaxtoluene sulfonates, monoand poly-substituted wax naphthalene sulfonates, monoand poly-wax substituted cyclo-hexyl sulfonates and the like.

The oil-dispersible magnesium complex disclosed herein is employed in an amount sufficient to confer improved engine cleanliness properties to the resulting composition. Thus, the specific amount of the magnesium complex to be employed may vary with the severity of the lubricating services required. For example, when lubricating twocycle engines operating on fuels containing tetraethyl lead or similar octane-improving agent, the amount of magnesium complex may be more than that required when the fuel is unleaded. In general, however, the magnesium complex is employed in amounts of about 0.5 to about 3 percent by weight based on the weight of the lubricating composition.

The esters employed in the composition of the invention are preferably those formed from fatty acids having from about to about 24 carbon atoms and aliphatic monohydric alcohols having from 1 to 18 carbon atoms or more. The alcohols and acids are selected to produce esters having from 12 to 30 carbon atoms in the molecule. Fatty acids having from about 10 to 24 carbon atoms are prevalent, chiefly in the form of glyceryl esters, in animal and vagetable fats and oils such as lard, lard oil, tallow, palm oil, coconut oil, cottonseed oil, etc. The principal acids of such fats and oils are palmitic, stearic and oleic but also included are acids such as lauric, myristic, arachidic, palmitoleic, linoleic, linolenic, and the like. The compositions of the invention can contain an ester of any of such acids or any mixture of esters of such acids. Preferably, mixtures of the esters of the acids obtainable from natural fats or oils are employed. A commercial mixture of esters of this type which can be used in compositions of the invention is known as methyl lardate.

This mixture comprises the methyl esters of the fatty acids derivable from lard and lard oil.

In addition to the above esters, we can employ sperm oil or esters of sperm oil. Sperm oil is composed principally of fatty acid esters of monohydric alcohols of relatively high molecular Weight, i.e., tetradecanol, hexadecanol and octadecanol, and, being a mono-ester, sperm oil is a liquid wax of the ester type. Being an ester, it is also different from the parafiin hydrocarbons commercially known as waxes. Sperm oil is obtained from the head cavities and blubber of the cachelot or sperm whale (Physeter macrocephalus). Commercial sperm oils are obtained upon removing solid components from the crude sperm oil by refrigeration and pressing. A commercial mixture of esters of sperm oil which can be used in the lubricating composition of the invention is known as Methyl Sperm 40. Other commercially available mixtures of esters of sperm oil which can be used as Sperm Methyl Esters, Methyl Sperm Ester and Mayco Methyl Ester 8-8.

Esters other than the methyl esters of the described acids can be employed in the compositions of the invention. Although for convenience, the esters of the compositions of the invention are referred to as esters of the indicated alcohols and acids, as is customary in the art, it is not meant to imply that such esters are necessarily obtained directly from the particular alcohol or acid.

Also for convenience, the conventional practice of referring to fatty acids as the acids of certain fats or oils, e.g., the lard or lard oil acids, is followed in the specification. It is recognized, however, that strictly speaking the natural fats and oils have little if any, content of free acids but are composed principally of triglycerides of fatty acids. From such triglycerides the esters used in the composition of the present invention can be prepared by such procedures as hydrolysis followed by esterification of the resulting free acids, or more simply by alcoholysis or ester-ester interchange with the triglycerides.

The esters disclosed herein are employed in an amount sufficient to improve still further the lubricating characteristics. The exact amount of ester employed may vary with the severity of the lubricating services as well as with the particular ester and particular magnesium complex employed. In general, however, the ester comprises about 0.5 to about 5 percent by weight of the lubricating composition.

In producing a lubricant-gasoline mixture for a twocycle gasoline engine, the gasoline can be either a straightrun gasoline or a gasoline obtained from a conventional cracking process, or mixtures thereof. The gasoline to which the lubricating composition is added, in accordance with the invention, can also contain components obtained from processes other than cracking such as alkylation, isomerization, hydrogenation, Platforming, or combinations of two or more such processes, as well as synthetic gasoline obtained from the Fischer-Tropsch and related processes. The gasoline is preferably unleaded gasoline consisting predominantly of saturated components. However, the lubricating composition of the invention can also be utilized in a fuel for a two-cycle engine wherein the gasoline contains an anti-knock agent, such as tetraethyl lead, in amounts up to about 3 cc. or more per gallon of gasoline. A gasoline which consists of at least about percent by volume of saturated components and a total of not more than about 5 percent by volume of aromatics and olefins is especially preferred. The ratio of gasoline to oil varies according to the recommendations of engine manufacturers. In general, however, the gasoline to oil volume ratio is between about 16:1 and about 40:1. It will be understood, of course, that amounts outside these ranges can also be employed.

In order to illustrate the improved results obtained with lubricating compositions of the invention, a number of comparative lubricating oil blends were prepared and tested by an approved test procedure employing a 50- 5 horsepower, 4-cylinder, outboard engine. According to this test procedure, the engines are operated for an actual running time of 100 hours unless mechanical failure is encountered. The engines are operated for four hours at wide open throttle followed by a shutdown for one hour.

The methyl sperm oil used in the lubricating compositions reported hereinafter was Methyl Sperm Oil 40. The methyl oleate used was Methyl Oleate G. The magnesium complex used was Hybase M300. Typical properties of the magnesium complex and methyl sperm oil are as follows:

Properties Methyl Magnesium Sperm Oil Complex Gravity, AII 31. 3 Specific Gravity, 60l60 F 0. 809 1. 070 Viscosity, SUS:

51. 4 At 210 F 34. 2 922 Flash Point, 00, F. 350 365 Fire Point, 00, F-.- 380 385 Pour Point, F +55 +35 Color, ASTM D 1500.. 1. 5 6. 5 Sulfur, Perccnt 0.1 2.20 CtlOi1l1I1. 0.16 Magnesium. 7. 26 Total Base No., ASTM D-66 310 Suliated Ash, ASTM D810--.-- 37. 9

The fuel employed in the tests reported hereinafter in Table I was an unleaded Marine White gasoline containing the lubricating oil composition in a gasoline to oil volume ratio of 20 to 1. Typical properties of the unleaded gasoline are as follows:

Gravity: API 70.3 Sulfur, L; percent 0.02 Chemical evaluation, percent:

Olefins 0.9 Aromatics 2.8 Saturates 96.3 Knock rating Motor method 80.6 Research method 81.3 Distillation, F.:

Over point 120 End point 320 At 10 160 At 50% 222 At 90% 248 The make-up of the comparative lubricating oil compositions and the results obtained in the above-described approved test procedure are set forth in Table I.

TABLE I Composition, Percent By Volume A B C D E Paraffinic Oil (450 sUs at 100 F.) 75. 0 73. 0 74. 0 72. 0 72. 0 Bright Stock (2,572 80s at 100 F.)

(155 SUS at 210 F.) 25. 0 25. 0 25. 0 25. 0 25. 0 Magnesium Complex. 1.0 1.0 1.0 Methyl Sperm 011.- 2. 0 2. 0 Methyl Olcate 2.0 Gasoline, Oil Ratio. :1 20:1 20:1 20:1 2011 Test Duration, I-Iours 100 100 1 60 100 100 Test Results:

Average Piston Skirt Deposit Rating (10 Perfect) 3. 3 2.0 7.3 7.2 Average Piston Ring Sticking Rating (10 Perfect):

Top Ring 6.0 6.0 10 9.0 Other Rings 7. 0 6. 0 10 10 1 Test terminated because of failure of crankpin needle bearing.

As can be seen from the data in Table I, compositions of the invention, i.e., Compositions D and E, are surprisingly superior to the base oil alone and to the base oil con taining only one of the additives. It will be noted, for example, that while Composition A which contained neither the magnesium complex nor the ester gave a test duration of 100 hours, the engine was dirty as evidenced by average piston skirt rating of 3.3 and the top ring sticking rating of 6.0. When two percent of methyl sperm oil was added to the base oil, as in Composition B, the base oil was not improved, the test results showing a decrease in engine cleanliness over the base oil alone.

When one percent of the magnesium complex was added to the base oil, as in Composition C, the test had to be discontinued after only 60 hours because of a crankpin needle bearing failure. Because of the bearing failure when using Composition C, no comparable cleanliness data was obtained. When the base oil contained both the magnesium complex and the methyl ester, as in Compositions D and E, the test duration was hours, and the piston skirts and piston rings were surprisingly clean, the piston rings having an almost perfect rating.

Typical properties of Compositions A, B, C, D and E used in the tests described hereinabove are shown in Table 11.

TABLE II Composition A B C D E Gravity, API 28.6 28.4 28 1 27.9 27.8 Viscosity, SUS:

At 100 F 090 641 7 654 622 At 210F-. 74.0 72.4 74.8 72.9 71.6 Viscosity Index. 98 101 98 101 102 Flash Point, OC,F 520 490 500 480 Fire Point, OC,F-- 570 545 555 Neutralization Value, AS

Total Acid No 0.1 0.1 0.7 1.1 0.7

Total Base No 0.1 0.1 3.8 3.8 2.5 Sulfated Residue, percent. 0.1 0.1 0.46 0.41 0.41 Magnesium, percent 0.08 0 08 0.08

In order to illustrate still further the utility of a lubricating composition of the invention (Composition D reported above), one volume of the composition was added to twenty volumes of a gasoline containing 2.7 ml. of tetraethyl lead per gallon of gasoline. The fuel thus obtained was employed in a lo-horsepower, 2-cylinder, outboard engine. The test procedure employed was the Outboard Boating Club (0.13.0) Outboard Test Procedure. According to the 0.3.0. procedure, the engine is opearted for 100 hours of cyclic operation each cycle consisting of 55 minutes at full throttle (4500 rpm.) and 5 minutes at an idling speed (600-850 r.p.m.). Durin the 5 minutes idle, there are 5 rapid accelerations to As can be seen from the above data, the lubrication composition of the invention gives excellent engine cleanliness and freedom from severe preignition with a minimum of spark plug failure and only one instance of mild preignition even when using a leaded gasoline.

The lubricating composition of this invention can contain conventional lubricant additives, if desired, to improve other specific properties of the lubricant without departing from the scope of the invention. Thus, the lubrieating composition can contain a corrosion and rust inhibbitor, an extremen pressure agent, an antioxidant, an antifoamant, a metal deactivator, a viscosity index improver, a dye, and the like. Whether or not such additives are employed and the amounts thereof depend to a large extent upon the severity of the conditions to which the composition is subjected and upon the stability of the lubricating oil base in the first instance. When such conventional additives are used they are generally added in amounts between about 0.01 and 5 percent by weight based on the weight of the total composition.

While our invention has been described with reference to various specific examples and embodiments, it will be understood that the invention is not limited to such examples and embodiments and may be variously practiced within the scope of the claims hereinafter made.

We claim:

1. A lubricating composition consisting essentially of a major amount of a mineral lubricating oil having a viscosity of about 600 to about 800 SUS at 100 F.; about 0.5 to about 3 percent by weight of an oil-dispersible magnesium complex prepared by (a) reacting magnesium with an excess of an alkanol containing less than six carbon atoms to form an alkanol insoluble magnesium alkoxide, (b) forming an alkanol soluble magnesium alkoxide-carbon dioxide complex by passing carbon dioxide through the magnesium alkoxide-alkanol mixture until the same is acid to alpha-naphthol benzein indicator, reacting an excess of the alkanol soluble magnesium alkoxide-carbon dioxide complex with an oil-soluble organic sulfonate selected from the group consisting of alkyl, alkaryl, naphthenyl, alkylnaphthenyl and napthenylaryl sulfonates in a hydrocarbon oil reaction medium and in the presence of sufiicient water to form a homogeneous system, and (d) condensing from said homogeneous system an oil insoluble magnesium compound in particles the diameter of which are less than 0.25 micron by heating said system whereby said alkanol is removed and said magnesium alkoxide-carbon dioxide complex is decomposed to produce said oil-dispersible magnesium complex having a total base number of about 100 to about 400; and about 0.5 to about 5 percent by weight of an ester having from 12 to 30 carbon atoms in the molecule formed from an aliphatic monohydric alcohol having from 1 to 18 carbon atoms and a fatty acid having from to 24 carbon atoms.

2. A lubricating composition consisting essentially of a major amount of a mineral lubricating oil base comprising about 65 to about 85 percent by weight of a parafiinic mineral oil distillate having a viscosity of about 400 to about 500 SUS at 100 F. and about to about 35 percent weight of a bright stock having a viscosity of about 2500 to about 4500 SUS at 100 F.; about 0.5 to about 3 percent by weight of an oil-dispersible magnesium complex prepared by (a) reacting magnesium with an excess of an alkanol containing less than six carbon atoms to form an alkanol isoluble magnesium alkoxide, (b) forming an alkanol soluble magnesium alkoxide-carbon dioxide complex by passing carbon dioxide through the magnesium alkoxide-alkanol mixture until the same is acid to alpha-naphthol benzein indicator, (c) reacting an excess of the alkanol soluble magnesium alkoxide-carbon dioxide complex with an oil-soluble organic sulfonate selected from the group consisting of alkyl, alkaryl, naphthenyl, alkylnaphthenyl and naphthenyl sulfonates in a hydrocarbon oil reaction medium and in the presence of sufiicient water to form a homogeneous system, and (d) condensing from said homogeneous system an oil insoluble magnesium compound in particles the diameter of which are less than 0.25 micron by heating said system whereby said alkanol is removed and said magnesium alkoxide-carbon dioxide complex is decomposed to produce said oil-dispersible magnesium complex having a total base number of about 250 to about 350; and about 0.5 to about 5 percent by weight of methyl oleate.

3. A lubricating composition consisting essentially of a major amount of a mineral lubricating oil base comprising aobut 65 to about 85 percent by weight of a paraflinic mineral oil distillate having a viscosity of about 400 to about 500 SUS at 100 F. and about 15 to about 35 percent by weight of a bright stock having a viscosity of about 2500 to about 4500 SUS at 100 F.; about 0.5 to about 3 percent by weight of an oil-dispersible magnesium complex prepared by (a) reacting magnesium with an excess of an alkanol containing less than six carbon atoms to form an alkanol insoluble magnesium alkoxide, (b) forming an alkanol soluble magnesium alkoxide-carbon dioxide complex by passing carbon dioxide through the magnesium alkoxide-alkanol mixture until the same is acid to alpha-naphthol benzein indicator, (c) reacting an excess of the alkanol soluble magnesium alkoxide-carbon dioxide complex with an oil-soluble organic sulfonate selected from the group consisting of alkyl, alkaryl, naphthenyl, alkylnaphthenyl and naphthenylaryl sulfonates in a hydrocarbon oil reaction medium and in the presence of sutficient water to form a homogeneous system, and (d) condensing from said homogeneous system an oil insoluble magnesium compound in particles the diameter of which are less than 0.25 micron by heating said system whereby said alkanol is removed and said magnesium alkoxide-carbon dioxide complex is decomposed to produce said oil-dispersible magnesium complex having a total base number of about 250 to about 350; and about 0.5 to about 5 percent by weight of methyl sperm oil.

4. A lubricant-gasoline mixture for a two-cycle gasoline engine consisting essentially of a major proportion of a gasoline motor fuel and a minor proportion of a lubricant consisting essentially of a major amount of a mineral lubricating oil having a viscosity of about 600 to about 800 SUS at 100 F.; about 0.5 to about 3 percent by weight of an oil-dispersible magnesium complex prepared by (a) reacting magnesium with an excess of an alkanol containing less than six carbon atoms to form an alkanol insoluble magnesium alkoxide, (b) forming an alkanol soluble magnesium alkoxide-carbon dioxide complex by passing carbon dioxide through the magnesium alkoxide-alkanol mixture until the same is acid to alpha-naphthanol benzein indicator, (c) reacting an excess of the alkanol soluble magnesium alkoxide-carbon dioxide complex with an oil-soluble organic sulfonate selected from the group consisting of alkyl, alkaryl, naphthenyl, alkylnaphthenyl and naphthenylaryl sulfonates in a hydrocarbon oil reaction medium and in the presence of sufiicient water to form a homogeneous system, and (d) condensing from said homogeneous system an oil insoluble magnesium compound in particles the diameter of which are less than 0.25 micron by heating said system whereby said alkanol is removed and said magnesium alkoxide-carbon dioxide complex is decomposed to produce said oil-dispersible magnesium complex having a total base number of about 100 to about 400; and about 0.5 to about 5 percent by weight of an ester having from 12 to 30 carbon atoms in the molecule formed from an aliphatic monohydric alcohol having from 1 to 18 carbon atoms and a fatty acid having from 10 to 24 carbon atoms, wherein the gasoline to oil volume ratio is between about 16:1 and about 40:1.

5. A lubricant-gasoline mixture for a two-cycle gasoline engine consisting essentially of a major proportion of a gasoline motor fuel and a minor proportion of a lubricant consisting essentially of a major amount of a mineral lubricating oil base comprising about 65 to about percent by weight of a parafiinic mineral oil distillate having a viscosity of about 400 to about 500 SUS at F. and about 15 to about 35 percent by weight of a bright stock having a viscosity of about 2500 to about 4500 SUS at 100 F.; about 0.5 to about 3 percent by weight of an oil-dispersible magnesium complex prepared by (a) reacting magnesium with an excess of an alkanol containing less than six carbon atoms to form an alkanol insoluble magnesium alkoxide, (b) forming an alkanol soluble magnesium alkoxide-carbon dioxide complex by passing carbon dioxide through the magnesium alkoxidealkanol mixture until the same'is acid to alpha-naphthol benzein indicator, '(c) reacting an excess of the alkanol soluble magnesium alkoxide-carbon dioxide complex with an oil-soluble organic sulfonate selected from the group consisting of alkyl, alkaryl, naphthenyl, alkylnaphthenyl and naphthenylaryl sulfonates in a hydrocarbon oil reaction medium and in the presence of sufficient water to form an homogeneous system, and (d) condensing from said homogeneous system an oil insoluble magnesium compound in particles the diameter of which are less than 0.25 micron by heating said system whereby said alkanol is removed and said magnesium alkoxide-carbon dioxide complex is decomposed to produce said oil-dispersible magnesium complex having a total base number of about 250 to about 350; and about 0.5 to about percent by weight of methyl oleate, wherein the gasoline to oil volume ratio is between about 16:1 and about 40:1.

6. A lubricant-gasoline mixture for a two-cycle gasoline engine consisting essentially of a major proportion of a gasoline motor fuel and a minor proportion of a lubricant consisting essentially of a major amount of a mineral lubricating oil base comprising about 65 to about 85 percent by weight of a paraflinic mineral oil distillate having a viscosity of about 400 to about 500 SUS at 100 F. and about to about 35 percent by weight of a bright stock having a viscosity of about 2500 to about 4500 SUS at 100 F.; about 0.5 to about 3 percent by weight of an oil-dispersible magnesium complex prepared by (a) reacting magnesium with an excess of an alkan'ol con taining less than six carbon atoms to form an alkanol insoluble magnesium alkoxide, (b) forming an alkanol soluble magnesium alkoxide-carbon dioxide complex by passing carbon dioxide through the magnesium alkoxide- -alkanol mixture until the same is acid to alpha-naphthol benzein indicator, (-0) reacting an excess of the alkanol soluble magnesium alkoxide-carbon dioxide complex with an oil-soluble organic sulfonate selected from the group consisting of alkyl, alkaryl, naphthenyl, alkylnaphthenyl and naphthenylaryl sulfonates in a hydrocarbon oil reaction medium and in the presence of sufiicient water to form a homogeneous system, and (c) condensing from said homogeneous system an oil insoluble magnesium compound in particles the diameter of which are less than 0.25 micron by heating said system whereby said alkanol is removed and said magnesium alkoxide-carbon dioxide complex is decomposed to produce said oil-dispersible magnesium complex having a total base number of about 250 to about 350; and about 0.5 to about 5 percent by weight of methyl sperm oil, wherein the gasoline to oil Volume ratio is between about 16:1 and about 40:1.

References Cited by the Examiner UNITED STATES PATENTS 2,236,590 4/1941 Backoff et a1. 4458 2,672,450 3/1954 Pearsall 4458 2,789,891 4/1957 Brandes et al. 4458 2,895,913 7/1959 Carlyle et al. 25233 FOREIGN PATENTS 843,169 8/ 1960 Great Britain.

DANIEL E. WYMAN, Primary Examiner.

Claims (1)

1. A LUBRICATING COMPOSITION CONSISTING ESSENTIALLY OF A MAJOR AMOUNT OF A MINERAL LUBRICATING OIL HAVING A VISCOSITY OF ABOUT 600 TO ABOUT 800 SUS AT 100*F.; ABOUT 0.5 TO ABOUT 3 PERCENT BY WEIGHT OF AN OIL-DISPERSIBLE MAGNESIUM COMPLEX PREPARED BY (A) REACTING MAGNESIUM WITH AN EXCESS OF AN ALKANOL CONTAINING LESS THAN SIX CARBON ATOMS TO FORM AN ALKANOL INSOLUBLE MANGESIUM ALKOXYIDE, (B) FORMING AN ALKANOL SOLUBLE MAGNESIUM ALKOXIDE-CARBON DIOXIDE COMPLEX BY PASSING CARBON DIOXIDE THROUGH THE MAGNESIUMALKOXIDE-ALKANOL MIXTURE UNTIL THE SAME IS ACID TO ALPHA-NAPHTHOL BENZEIN INDICATOR, (C) REACTING AN EXCESS OF THE ALKANOL SOLUBLE MAGNESIUM ALKOXIDE-CARBON DIOXIDE COMPLEX WITH AN OIL-SOLUBLE ORGANIC SULFONATE SELECTED FROM THE GROUP CONSISTING OF ALKYL, ALKARYL, NAPHTHENYL, ALKYLNAPHTHENYL AND NAPTHENYLARYL SULFONATES IN A HYDROCARBON OIL REACTON MEDIUM AND IN THE PRESENCE OF SUFFICIENT WATER TO FORM A HOMOGENEOUS SYSTEM, AND (D) CONDENSING FROM SAID HOMOGENEOUS SYSTEM AN OIL INSOLUBLE MAGNESIUM COMPOUND IN PARTICLES THE DIAMETER OF WHICH ARE LESS THAN 0.25 MICRON BY HEATING SAID SYSTEM WHEREBY SAID ALKANOL RE REMOVED AND SID MAGNESIUM ALKOXIDE-CARBON DIOXIDE COMPLEX IS DECOMPOSED TO PRODUCE SAID OIL-DISPERSIBLE MAGNESIUM COMPLEX HAVING A TOTAL BASE NUMBER OF ABOUT 100 TOABOUT 400; AND ABOUT 0.5 TO ABOUT 5 PERCENT BY WEIGHT OF AN ESTER HAVING FROM 12 TO 30 CARBON ATOMS IN THE MOLECULE FORMED FROM AN ALIPHATIC MONOHYDRIC ALCOHOL HAVING FROM 1 TO 18 CARBON ATOMS AND A FATTY ACID HAVING FROM 10 TO 24 CARBON ATOMS.