US3544466A - Two-cycle lubricating oil compositions - Google Patents

Description

United States Patent 3,544,466 TWO-CYCLE LUBRICATING OIL COMPOSITIONS Donald E. McDowell, Jackson, Jack Ryer, East Brunswick, and Harold E. Deen, Cranford, N.J., assignors to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Filed May 16, 1968, Ser. No. 729,543 Int. Cl. Cm 1/48 U.S. Cl. 252-46.7 19 Claims ABSTRACT OF THE DISCLOSURE Two-cycle mineral lubricating oils having a viscosity of from about 58 to about 85 SUS at 210 F. contain a small but elfective amount of the amide condensation product of an alkenyl substituted alpha-beta unsaturated monocarboxylic acid of between about 800 and about 3500 molecular weight and an alkylene polyamine together with a small but effective amount of an antioxidant which is the sulfide of phosphorus reaction product of an oil-soluble compound selected from the group consisting of alpha monoolefin polymers and copolymers, terpenes, and saturated and unsaturated primary and secondary C12-C20 alcohols, or the oils contain the sulfide of phosphorus reaction product of the aforementioned amide condensation product. Optionally, a lower viscosity base oil may have added thereto a sufficient amount of a viscosity index improving oil-soluble organic compound to achieve the above-defined viscosity of the oil composition. The oil compositions are used in admixture with gasolines, in a volume ratio of oil to gasoline of l to at least 20, preferably 1 to at least 50.

The present invention concerns the manufacture of mineral lubricating oil compositions which are primarily for use in two-cycle engines. More particularly, the invention is concerned with mineral lubricating oils containing an ashless detergent type of material and also containing an antioxidant or the ashless detergent type material may be employed alone if it has been so treated chemically as to give it also antioxidant properties.

In recent times, the two-cycle, or what is sometimes called the two-stroke, engine has become extremely widely used for the powering of chain saws, lawn mowers, small automobiles and has been used in outboard motors for powering various types of boats. Because of the twocycle feature of the engines, they do not have any provision for a crackcase nor for a pumped or forced oil flow circulating system, and so they must depend, for their lubrication, upon the presence of small amounts of lubricant admixed with the gasolines which fuels such engines. A large percentage of the actual lubricant which enters the combustion chamber in the two-cycle engines by way of gasoline being fed into the combustion chamber or chambers actually is burned along with the fuel before the oil has a chance to actually contact the piston rings or piston walls. Also, one of the outstanding problems involved in the use of such oils in conjunction with such gasoline involves the frequent and profound fouling of spark plugs, the clogging of exhaust ports, the deposition of excess quantities of carbon in the combustion chamber, the tendency to preignition of the fuel and the like. Another disadvantage of this method of lubricating in this type of engine is that considerable smoke and stench are created by reason of the exhaust gases being emitted during the operation of the engine. If a sufficiently high concentration of oil is placed in the gasoline to provide adequate lubrication, then the aforementioned disadvantages become more pronounced. If a lesser amount of oil is placed in the gasoline, there is always danger of insufficient and defective lubrication of the engine with the resultant danger to cylinder walls,

Patented Dec. 1, 1970 "ice piston rings, piston bearings and so forth. Furthermore, modern technology by the two-cycle engine manufacturers has resulted in the production of high output, increased horsepower engines running up to as high as and horsepower with the result that even critical demands are placed upon the use of lubricants which will stand up under the more rigorous conditions and more demanding performance of such high power output engines. Also, the revolutions per minute of such outboard motors have been increased which means that in more cases the need for improved lubrication of cooling and sliding surfaces to reduce friction between such moving surfaces is increased. Additionally, most gasolines Widely sold commercially contain lead alkyl compounds as antiknock agents. The presence of lead in the gasoline in many instances adversely affects the lubricating effectiveness of the two-cycle lubricating oils which have heretofore been employed. High temperatures resulting from preignition and other causes such as improper cooling can also lead to insufficient lubrication which, in turn, leads to excessive wear, high scufiing and scoring and even piston seizure.

There has been an increased need for a lubricating oil composition that will be more suitable than conventional motor oils for two-cycle engines, particularly for outboard motor service. Certain makes of engines are more critical than others. 'In general, modern high horsepower (i.e. above 18 horsepower, and particularly above 25 horsepower) outboard motors produce more plug fouling problems than do lower horsepower models. Severe plug fouling conditions are presented by full throttle operation with highly-leaded fuel (2 to 3 ml. per gallon).

A high-performance, two-cycle engine lubricant should be readily miscible with gasolines and should (1) provide good lubrication (low friction, lower wear, and no deformation, scufiing, scoring or seizing) of the rubbing parts such as anti-friction bearings, rings, pistons and cylinders; (2) maintain a clean combustion chamber with attendant long spark plug life and freedom from preignition; and (3) minimize power-robbing piston and port deposits. Also such a lubricant should protect against rusting.

The novel two-cycle lubricating oil compositions hereinafter described also possess the virtue of being usable in higher gasoline to oil dilutions than has heretofore been thought to be attainable. This is particularly advantageous when used in conjunction with the higher horsepower two-cycle engines because it has been discovered that there is greater cleanliness, less chance of plug fouling and less smoky exhaust when using such higher dilution of gasoline to lubricating oil. Heretofore, higher concentrations of additives at a 50 to 1 volume ratio of gasoline to oil resulted in serious operating problems such as preignition, exhaust port deposits and spark plug fouling. The ashless two-cycle engine lubricating oils at this dilution more than adequately control the problems of preignition, spark plug fouling, exhaust port deposits, smoky exhaust gases and the like. In fact, it is possible in the lower horsepower two-cycle engines to employ gasoline to oil dilution ratios of as much as 100 to 1 volume ratio with entirely satisfactory lubrication being effected under such conditions.

The novel two-cycle mineral lubricating oil composition contains a major amount of a base mineral oil which may be of any type, i.e. naphthenic, aromatic, paratfinic, or mixed, preferably paraflinic, having a viscosity at 210 F. of between about 58 and 85 SUS. Either the oil itself as blended may possess this viscosity or a solvent extracted neutral oil of a lower viscosity may be employed as a higher viscosity lubricating oil fraction is added thereto to raise the viscosity of the resultant blend or a small amount, up to as high as 7.5 wt. percent of a con ventional V.I. improver may be added to accomplish the same purpose. Incorporated in this base stock or one adjusted to the indicated viscosities is an amide which is the condensation product of a long chain alkenyl substituted alpha-beta unsaturated monocarboxylic acid having a number average molecular weight between 800 and about 3500 with an alkylene polyamine. These materials are old in the art having been employed as detergent and dispersant compositions in mineral lubricating oils employed in lubricating engines opearting on the Otto cycle and where in a pumped circulating oil system including a filter is customarily employed. 'In addition to the amide condensation product, there is also added a small amount, up to about 7.5 wt. percent of a sulfide of phosphorus reaction product of a compound selected from the group consisting of alpha monolefinic polymers and copolymers, terpenes, saturated and unsaturated primary and secondary C -C alcohols. This material serves as an antioxidant and while these materials have also been employed in conventional mineral lubricating oils for Otto cycle engines as well, many other types of oil-soluble antioxidants do not perform a satisfactory function in two-cycle engine lubricating oils. It is also possible to omit the use of this sulfide of phosphorus product as an antioxidant if the aforementioned amide before use is treated with a sulfide of phosphorus in which case the single compound then serves the dual function of being a satisfactory dispersant and a satisfactory antioxidant.

U.S. Patents 3,296,133; 3,290,130; and 3,310,492 all deal with the problem of improving the lubrication of two-cycle engines while at the same time seeking to avoid one or more of the aforementioned difliculties in operating two-cycle engines where the lubricant is supplied to the engine by way of the gasoline fueling the engine. Individually, phosphosulfurized terpenes and phosphosulfun'zed polyolefins such as polyisobutylene have been employed in two-cycle engine lubricants in conjunction with the alkaline earth metal organic sulfonates. Additionally, the polyisobutenyl succinic anhydride amide condensation product with an alkylene polyamine has also been employed as an additive in two-cycle lubricating oil compositions but as the more detailed description hereinafter shows the results have not been nearly so advantageous in terms of eliminating the aforementioned problems as have been achieved by the unique combination of additives in the hereindisclosed two-cycle engine lubricating oil compositions.

The base stock for two-cycle lubricating oil compositions should be clean burning and they should be of the aforementioned viscosities at 210 F. Solvent refined neutral lube oil fraction distillates roughly corresponding to SAE 30 and SAE 40 lubricating oils and preferably of parafiinic nature constitute for the most part the desirable base stocks into which one or more of the additives specified are incorporated. The base stock should have a viscosity index of from about 90 to about 100 but higher viscosity index oils, up to 110 may also be used. The oil base stocks should have particular low Conradson group residues, i.e. of less than 0.1 wt. percent. Highly refined residual stocks such as bright stock burn less completely than the highly refined all distillate stocks but these refined residual stocks are useful in limited amounts, i.e. to the extent of from to volume percent of the total base stock for two-cycle engine applications.

The ashless detergent, i.e. the amide condensation product, is present in an amount ranging between about 0.2 and about volume percent of the total lubricating oil compounded composition, preferably between about 3 and about 15 volume percent. The amide material is conventional for the sake of completeness, however, it may be stated that it involves the condensation of an alkylene polyamine with an alkenyl substituted alpha-beta olefinically unsaturated monocarboxylic acid. This material will have a number average moleculer weight of between about 800 and about 3500. and may be produced in a number of ways, for example, such acids can be prepared by oxidizing high molecular weight olefins, i.e. polyisobutylene, of the required molecular weight with an oxidizing agent such as nitric acid or oxygen followed by the addition of an aldehyde to the polymer. This addition product is then, in turn, oxidized or a halogen can be added such as chlorine or bromine to the high molecular weight polyolefin to form a dihalo compound which then is treated by hydrolyzing oxidation. These procedures are shown in British Patent No. 983,040. The same materials can be produced by oxidizing a monohydric alcohol with potassium permanganate or by reacting a halogenated high molecular weight olefin polymer with a ketene. The same monocarboxylic acids can also be prepared from olefin polymers such as a polymer, or copolymer of a C -C monoolefin, isolating from the product the polymer of the desired molecular weight, halogenating the same and then condensing it with an alpha-beta unsaturated moncarboxylic acid. In other words, by intimately contacting chlorine or bromine with polyisobutylene, polypropylene or ethylene/propylene copolymer, a halo polymer is formed. This is usually carried out in a suitable solvent such as carbon tetrachloride at a temperature of 50- 300 F. and in about 2 to 5 hours. The halogenated polymer is then condensed with the monocarboxylic acid which is usually from 3-8 carbon atoms, preferably 34 carbon atoms. Because of commercially availability, acrylic acid and alpha methacrylic acid are the preferred acids although crotonic, isocrotonic, tiglic, angelic, sorbic, and cinnamic acids may be used as well. Normally, one mole of acid is empolyed per mole of halogenated polyolefin, however, the acid is sometimes employed in molar excess to the amount of halogenated polyolefin and may amount to as much as 1.5 to about 2 moles per mole of halogenated polyolefin. The condensation temperature ranges from between 300 and 500 F. and the time of reaction is from 3-24 hours, most preferably 6-18 hours. Any excess acid may be removed from the reacted mixture by blowing with, nitrogen gas at 400500 F.

The alkylene polyamine employed as one reaction in the amide condensation reaction can be any of these which have been customarily employed in such reactions. They conform to the general formula:

wherein n is 2 to 4 and m is an integer from 0 to 10. Specific compounds coming within the formula include diethylene triamine, triethylene tetramine, tetraethylene pentamine, dibutylene triamine, dipropylene triamine, hexaethylene heptamine, octaethylene nonamine, and tetrapropylene pentamine. Other amines can also be used such as N (2 aminoisopropyl)piperazine, N,N'di(2 aminoethyl) piperazine.

The proportion of the long chain alkenyl monocarboxylie acid, for example, polyisobutenyl propionic acid to alkylene polyamine, for example, tetraethylenepentamine, may range between about 1 to 5 moles of acid per mole of polyamine, preferably between about 1 to 1 and about 3 to 1. The reactions are carried out at a temperature of about 200-400 F. under conditions such as to drive off the water of condensation which is removed by blowing with an inert gas such as nitrogen. Generally, the temperatures are between about 250 and 350 F. and the time of reaction is between about 6 and about 20 hours. This amide material may be used as such in conjunction with the hereinafter described antioxidants. It may also, however, be further treated with a sulfide of phosphorus such as phosphorus pentasulfide, phosphorus sesquisulfide, phosphorus heptasulfide, and the like.

The same sulfides of phosphorus may also be used but preferably phosphorus pentasulfide is employed for the treatment of terpenes such as alpha pinene, for the treatment of alpha olefin polymers such as polyisobutylene, or for the treatment of saturated or unsaturated primary or secondary alcohols whose alkyl or alkenyl radicals contain from 12 to 20 carbon atoms. Unexpectedly, these materials serve as satisfactory antioxidants when used in conjunction with the aforementioned amide condensation product. Surprisingly, the amide condensation product directly treated with phosphorus pentasulfide serves the dual function of an ashless dispersant and an antioxidant, however, it is within the scope of the present invention to employ not only the amide condensation product in conjunction with one or more of the phosphosulfurized terpenes, polymeric olefins, or alcohols specified but one may also employ both the amide condensation product and the phosphosulfurized amide condensation product. Further, one may employ a mixture of amides employing different alkenyl carboxylic acids and a different alkylene polyamine or the same reactants but wherein the mole ratio of the polyisobutenyl propionic acid, for example, tetraethylenepentamine, would be 1.8 to 1 instead of the preferred 2.8 to 1. The amount of phosphosulfurized antioxidant employed will range between about 0.5 and about 7.5 volume percent when it is employed. This is on the basis of a 50% concentration of active ingredient in a light mineral oil. The amount of the amide condensation product employed, whether in phosphosulfurized form or not, will range between about 0.2 and about 20 volume percent, preferably between about 3 and about volume percent, again based upon a concentrate, having between about 65 and about 75% active ingredient, with a light mineral base oil which is a solvent neutral paralfinic frac tion of about 150 SUS at 100 F.

Various types of viscosity index (V.I.) improvers which are conventional in nature may also be incorporated into the two-cycle engine lubricating oil compositions. These also serve in many instances as thickeners. They are chiefly used in those cases where the base oil has a viscosity below 58 SUS at 210 F. for the purpose of adjusting the viscosity so that it falls between 58 and 85 SUS at 210 F. These materials are well known and includes the use of polyisobutylene, of a number average molecular weight ranging between about 100,000 and about 150,000, the use of ethylene/propylene, polyethylene, polypropylene, polymethylrnethacrylate esters, vinyl acetate, lauryl fumarate copolymers and various other types of polymeric materials which are equally well known in the art as additives for lubricating oil compositions either for the purpose of thickening oils or for improving their viscosity index, or for both purposes. Generally, these materials are, for convenience, handled as oil concentrates. In the following examples, the polyisobutylene employed has a number average molecular weight of about 100,000 and is generally marketed as a concentration in solvent neutral paraflinic oil having a viscosity of about 150 at 100 F. The amount of V1. improver or thickening agent will vary, depending upon the base oil used and in many instances where a blend of parafiinic lubricating oil is employed the final viscosity of between about 58 and 85 SUS at 210 F. will be achieved without the necessity for adding any thickening or V.I. improving agent. On the other hand, where lower viscosity base stocks or blends of base stocks are employed, a sufiicient amount of the thickening agent will be added so that the base oil will conform to the abovementioned viscosity specification since it has previously been determined that two-cycle engine oil lubrication compositions should have the aforementioned viscosity specification.

Many of the commercially available gasolines which are customarily employed in operating internal combustion engines are suitable for use in admixture with the two-cycle lubricating oil compositions herein described. These gasolines for the most part commonly contain between about 0.5 and about 7.0 cc. per gallon, preferably 2.0 to 3.0 cc. per gallon, of alkyl lead anti-knock agents such as tetraethyl lead, tetrarnethyl lead, dimethyl diethyl lead or similar alkyl lead anti-knock agents. Other organo metallic additives can be employed containing lead, iron, nickel, lithium, manganese and the like. Other additives sometimes are employed such as antioxidants, corrosion inhibitors, anti-static agents, dyes, anti-icing agents, such as isopropanol, hexylene, glycol and the like, but these are conventional and the successful use of the novel twocycle lubricating oil is not dependent upon the use of such conventional additives in gasoline. It is generally advantageous, however, to incorporate into the gasoline concentrations of arylene or alkylene, bromides or chlorides in concentrations of from 0.5 to 3.0 theories. For example, 0.8 to 1.5 theories of ethylene dichloride, or 0.3 to 0.8 theories of ethylene dibromide are used as scavenger agents where the gasoline contains the organo lead anti-knock agents. These are conventional practices and are not particularly correlated with the novel combination of additives employed in the two-cycle lubricating oil compositions.

As before stated, the particular lubricating oil compositions herein disclosed do, however, have a distinct advantage when admixed with the conventional gasolines used in operating two-cycle engines because of the fact that the gasoline to oil volume or weight ratios are considerably increased with entirely satisfactory results through the use of these novel lubricating oil compositions. Whereas, in prior practice, a 20 to l, 30 to l or even as high as a 40 to 1, gasoline to oil ratio was considered necessary in order to impart satisfactory lubrication in a two-cycle engine. The novel lubricating oil composition herein described will achieve the same or even better lubricating results in a two-cycle engine where the gasoline to oil ratio is of the order of 50 to 1, up to as high as to 1. In fact, this is one of the outstanding advantages involved in the use of the herein described novel lubricating oil compositions. As before stated, the lower the concentration of lubricating oil in the gasoline fueling a two-cycle engine, the less the tendency for spark plug fouling, exhaust port clogging, or deposition and carbon and varnish formation on the cylinder walls and pistons. All of these advantages even including the tendency toward preignition are achieved without sacrificing the required minimum lubrication values for the operation of the two-cycle engine.

In the following examples, a series of comparative runs were undertaken, identified as Panel Coker Tests. These are primarily laboratory scale or bench tests designed to give a fairly good indication of what can be expected in ultimate two-cycle engine tests. In this test, the particular formulated two-cycle oil is splashed on the hot steel plate, maintained at a temperature of 550 F., and is then allowed to drain. The cycle of operation consists of 15 seconds in which the oil formulation is splashed on the hot steel plate followed by a period of 45 seconds for allowing the oil to drain from the plate. Thirty of these cycles in sequence are preferred. In other words, the test in each case lasts for 30 minutes total time. At the end of the test, the steel panel is weighed in order to determine the amount of deposition left on the steel panel. This deposition is measured in milligrams. Additionally, the degree of coke and varnish deposits left on the steel panel are visually rated with the scale being 0 where no deposits are found and the numeral 10 being used where the entire surface is covered 100% with black deposits. This test in a preliminary manner determines the amount and extent of deposition formation and directionally indicates the deposit forming tendency of the oil in two-cycle engine applications where the temperatures in the piston ring zone often approach 550 F.

The following examples are given as illustrative of the character of the invention but there is no intention that the invention be limited thereto.

EXAMPLES In the following Table I the results are given for a number of comparative runs in Panel Coker Tests which are indicative of the predicted performance of the various formulations when admixed with gasoline in at least a 50 to 1 volume ratio of gasoline to oil. Table I shows comparative results using an ashless dispersant with or without an antioxidant some of which are conventional antioxidants.

TABLE I.-PANEL COKER TESTS NOTE.-polyisbutylene=20% concentrate of polyisobutylene (100,000 molecular weight) in solvent neutral base oil of 150 SUS at 100 F.; Additive A=65 70% concentrate of 2.8 mols 0t polyisobutenyl propionic acid reacted w th 1 mol of tetraethylenepentamine (molecular weight about 900-1,000) 1n solvent neutral base oil of 150 SUS at 100 F.; Additive B= Commercially available oil antioxidant-a mixture of 4,4 methylene bis (2,6 di-tert. butylphenol) and oil-soluble phenols; Additive C=Commerv It is readily apparent that the phosphosulfurized antioxidants when used in conjunction with an ashless dispersant give unexpectedly excellent results in so far as the amount of deposits are concerned and the extent of the deposits are concerned. In particular, Examples 5, 6 and 7 and in particular Example 14 show outstanding results in this regard. It should also be noted that conventional antioxidants, i.e. those commercially available and which have been universally accepted as outstanding antioxidants for lubricating oils as shown in Examples 8 through 13, employed conventional oil antioxidants which were inadequate when employed in conjunction with an ashless dispersant in so far as their use is applied to twocycle engine oils. It is also apparent from Example 14 that no separate antioxidant is necessary if one uses a phosphosulfurized ashless dispersant as the additive to a two cycle engine lubricating oil.

A series of outboard engine tests were carried out, in

Weight of Ex. deposits, No. Base Oil Dispersant Antioxidant mgs. Rating 1 76.3 vol ercent solvent neutral paratfinic of 18.7 vol. percent Additive A- None 12. 9 7

200 S S at 100 F. plus vol. percent polyisobutylene. 2 dn dn 0.5 vol percent phosphosuliurized alpha 0 8 3 piglenfi as 50% concentration in light miner 0 3 vol. percent Bright Stock 150 SUS at 210 15.0 vol percent Additive A" None.. 12. 3 5

F., 75 vol. percent parafinic neutral of 600 SUS at 100 F. 4 do do 0.1 vol percent of Example 2- 11. 0 4 a do do 0.5 vol. percent of Example 2 6. 9 3 s rln rln 0.7 vol percent of Example 2 3. 8 2 7 do do 91.0 vol. percent of Example 2. 5 2 R dn do 0.2 wt. percent phenothiazine--- 7. 6 6 0 do do 0.5 wt. percent; N- benylalphanaphthalenm- 9. 3 8 10 do dn 0.5 wt. percent A ditive B 11. 8 7 11 do dn 0 5 wt percent Additive 0-- 15. 7 9 12 do do 0 5 wt percent Additwe D 15. 4 9 13 -do do 0.5 wt. percent Additive E 1 4 ..do 5 vol. percent Additive F- Trace 0 cially available oil antioxidant-4,4 bis (2,6 di-tert. butylphenol);Addil tive D=Commercially available oil antioxidant-4,4 thio bis (6 tert. butyl orthocresol) Additive E Commercially available oil antioxidantcondensation roduct of 2 mols of formaldehyde, 2 mols of nonylphenol and 1 mol of ethylene triamine; Additive F=Additive A reacted with 10 wt. percent of P 8 general, in accordance with the brochure entitled Tentative Test Procedures for Evaluating Outboard Motor Oils (two-cycle), Recommended Practices, published by the Boating Industry Association of Chicago, Ill. (1966).

Minor deviations from these procedures were made if through the use of polyisobutylene as described in connection with the oils used in the Panel Coker Tests (Table I). In all of the test runs, Examples 15-19, 15 volume percent of the amide ashless detergent concentrate and 1 volume percent of the phosphosulfurized pinene concentrate used in the Panel Coker Tests, were used, except that Run 16 used only one-half of these amounts. All test runs passed the test limit specifications set by the Boating Industry Association.

TABLE IL-TWO-CYCLE OUTBOARD ENGINE TESTS [Fuel/Lube Oil Ratio: to 1-Time: 981:0 100 hours] Example Number J ohnson-SO hp. J ohnson-33 hp. Johnson-100 hp. Mercury-50 hp. McCulloch (3- 4 9.5 (2-cycle)( 40.5 (89.5 total (4-cycle) cycle) hp. (63 Engine total CID) total CID) CID) total CID) total CID) Average engine test results:

Piston skirt, varnish (CRO) 8. 0 8. 6 6. 6 8. 5 7. 5 Top ring stickinii;l 7. 1 7. 5 6. 1 9. 5 6. 7 Bottom ring stic g 1 10. 0 10. 0 10. 0 10. 0 10. 0 Spark plug fouling, total No 2 2 1 5 7 None Exhaust passage blocking, pereent-- 0 5 2 2 2 Exhaust port blocking, percent. 4 1. 5 4. 5 0 0 Preignition None None None None None Sending/scoring None None N one None None Total engine deposits, gms 54. 29. 8 34.

1 Ring sticking rating: 10 is completely free; 0 is fully stuck.

9 Surface gap plugs.

NOTES:

Examples 15, 16 and 19 employed premium grade gasoline. Examples 17 and 18 used. regular grade gasoline. All gasolines contained from 2.6 to 2.9 cc. per gallon of tetraethyl lead. Examples 15 and 16 only contained 0.25 Theories of phosphorus added as cresyl diphenyl phosphate in the gasoline. Other examples used gasoline containing no phosphorus.

Examples 15, 17, 18 and 19 employed a base 0 cent of solvent neutral oil of 450 SUS at F ilblend of 10 volume percent of Bright Stock of Example 3 and 74 volume per Example 16 employed the base oil blend of Example 3.

All examples employed 16 volume percent of phosphosulfurized antioxidant, the same as t used in Example 16 Total CID refers to cubic inches, displacement for the total of all cylinders In another engine test carried out substantially the same as in Example 15, but containing no P 8 treated alpha pinene, 8 total plugs failed and scufiing in No. 2 and No. 4 cylinders was apparent. This test failed to meet specifications.

Another test carried out as in Example 17, but the oil employed being without P 8 treated alpha pinene, also failed by reason of a total of 12 spark plugs fouled. There was scufiing of No. 3 piston skirt as well.

Still another comparative run was carried out after the manner of Example 18 except no antioxidant was present in the oil. This showed a total of 12 spark plugs fouled with heavy scufling and scoring of cylinder walls and piston skirts.

A commercially available ashless dispersant additive for two-cycle outboard engines was used in a test run as shown in Example except that the additive was in the amount of 5.7 volume percent in place of both the 15.0 volume percent of the amide condensation product and the 1.0 volume percent of the antioxidant used in Example 15. This test run failed to meet specifications. It showed a total number of spark plugs fouling of 14 and some scuffing in No. 2 cylinder.

Having now thus fully described and illustrated the invention, what is desired to be secured by Letters Patent 1. A two-cycle mineral lubricating oil composition comprising a major amount of a base mineral oil of lubricating viscosity between about 58 and about 85 SUS at 210 F. containing between about 0.2 and about 15.0 volume percent of an amide of the group consisting of the condensation product of an alkenyl substituted alpha, beta unsaturated monocarboxylic acid of between about 800 and about 3500 number average molecular weight and an alkylene polyamine and the sulfide of phosphorus reaction product thereof, as an antioxidant, between about 0.0 and about 7.5 volume percent of sulfide of phosphorus reaction product of a compound selected from the group consisting of alpha monoolefin polymers and copolymers, terpenes, and saturated and unsaturated primary and secondary C -C alcohols, and from about 0.0 to about 7.5 volume percent of a viscosity index improver, the composition containing at least one sulfide of phosphorus treated above-stated organic compounds.

2. An oil composition as in claim 1 wherein the sulfide of phosphorus is phosphorus pentasulfide.

3. An oil composition as in claim 1 wherein the amide is the condensation product of an alkenyl monocarboxylic acid of between about 800 and about 3500 number average molecular weight and an alkylene polyamine and wherein the composition contains a sulfide of phosphorus reaction product of a terpene and a poly alpha monoolefin as a viscosity index improver.

4. An oil composition as in claim 3 wherein the sulfide of phosphorus is phosphorus pentasulfide.

5. An oil composition as in claim 3 wherein the composition contains sufiicient oil-soluble viscosity index improver to achieve an oil composition viscosity of between about 58 and about 85 SUS at 210 F., the base mineral oil being parafffinic and below the specified viscosity in unadulterated conditions.

6. An oil composition as in claim 3 wherein the amide is the condensation product of polyisobutenyl propionic acid and tetraethylenepentamine and the antioxidant is phosphorus pentasulfide treated alpha pinene.

7. An oil composition as in claim 6 wherein the composition also contains polyisobutylene of between about 100,000 and about 150,000 number average molecular weight.

8. An oil composition as in claim 1 wherein the amide is the condensation product of an alkenyl monocarboxylic acid of between about 800 and about 3500 number average molecular weight and an alkylene polyamine which is thereafter reacted with a sulfide of phosphorus.

9. An oil composition as in claim 8 wherein the sulfide of phosphorus is phosphorus pentasulfide.

10. A combined lubricant and fuel composition for the fueling and lubrication of two-cycle internal combustion engines comprising a gasoline containing the oil composition of claim 1 in the amount of one volume of oil to at least 20 volumes of gasoline.

11. A composition as in claim 10 wherein the oil composition also contains an alkyl lead anti-knock agent and a. halide scavenger therefor.

12. A composition as in claim 10 wherein the oil composition is that of claim 2.

13. A composition as in claim 10 wherein the oil composition is that of claim 3.

14. A composition as in claim 10 wherein the oil composition is that of claim 4.

'15. A composition as in claim 10 wherein the oil composition is that of claim 5.

16. A composition as in claim 10 wherein the oil composition is that of claim 6.

17. A composition as in claim 10 wherein the oil composition is that of claim 7.

18. A composition as in claim 10 wherein the oil composition is that of claim 8.

19. A composition as in claim 10 wherein the oil composition is that of claim 9.

References Cited UNITED STATES PATENTS 3,184,411 5/ 1965 Lowe 25246.7 2,721,862 10/ 1955 Brennan 25246.7 X 3,216,936 11/1965 Le Suer 4458 X 3,310,492 3/1967 Benoit 4458 X 3,449,249 6/ 1969 Anderson 25259 FOREIGN PATENTS 983,040 2/1965 Great Britian. 1,417,499 10/1965 France.

OTHER REFERENCES Towle Lubrication Problems in Two-stroke Petrol Engines Scientific Lubrication, March 1959, pages 12-14 and 16-20.

DANIEL E. WYMAN, Primary Examiner W. H. CANNON, Assistant Examiner US. Cl. X.R. 44-5 8