US3850822A - Ashless oil additive combination composed of a nitrogen-containing ashless dispersant phosphosulfurized olefin and phosphorothionyl disulfide - Google Patents

Abstract

An additive package particularly useful for use in internal combustion engine lubricating oils comprises from 30 to 80 wt. percent of a nitrogen-containing dispersant made by reaction of an alkylene polyamine with a mono- or dicarboxylic acid or anhydride substituted with a C50-C250 essentially hydrocarbon chain, 3.0 to 30 wt. percent of an antiwear agent prepared by reacting a terpene, petroleum fraction or 500-20,000 molecular weight C2-C6 polymer with a phosphorus sulfide, and 3.0 to 30 wt. percent of a phosphothionyl disulfide of a C1-C18 alkyl phenol as an antioxidant.

Description

United States Patent [191 Steere et a1.

[ ASHLESS OIL ADDITIVE COMBINATION COMPOSED OF A NITROGEN-CONTAINING ASHLESS DISPERSANT PHOSPHOSULFURIZED OLEFIN AND PHOSPHOROTHIONYL DISULFIDE [75] Inventors: David E. Steel-e, Sarnia; Edwin C.

Younghouse, Cranford, Ontario, both of Canada [73] Assignee: Exxon Research and Engineering Company, Linden, NJ.

[22] Filed: July 14, 1972 [21] Appl. No.: 271,718

[52] US. Cl 252/34.7, 252/46.6, 252/46.7 [51] Int. Cl C10n 1/32 [58] Field of Search 252/46.6, 46 F, 34 F [56] References Cited UNITED STATES PATENTS 2,307,183 1/1943 Zimmer et a] 252/46 F 2,343,831 3/1944 Osborne 252/46.6 2,443,264 6/1948 Mikeska 252/46.6 2,591,577 4/1952 McDermott 252/46.6

[451 Nov. 26, 1974 2,607,736 8/1952 Watkins 252/46.6 2,631,132 3/1953 McDermott 252/46.6 2,689,846 9/1954 Beegle 252/46.6 3,219,666 11/1965 Norman et a1 252/51.5 A X 3,687,848 8/1972 Colclough et a1 252/46.6 X

OTHER PUBLICATIONS Smalheer, C. V. and Smith, R. K., Lubricant Additives 1967, page 9.

Primary Examiner-Patrick P. Garvin Assistant ExaminerAndrew H. Metz Attorney, Agent, or Firm-Byron O. Dimmick [5 7] ABSTRACT sulfide, and 3.0 to 30 wt. percent of a phosphothionyl disulfide of a C C alkyl phenol as an antioxidant.

8 Claims, No Drawings ASHLESS OIL ADDITIVE COMBINATION COMPOSED OF A NITROGEN-CONTAINING ASHLESS DISPERSANT PHOSPIIOSULFURIZED OLEFIN AND PHOSPHOROTI-IIONYL DISULFIDE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an additive package particularly suitable for use in lubricating oils comprising an ashless nitrogen-containing dispersant, a phosphosulfurized olefinic hydrocarbon antiwear agent and a phosphorothionyl disulfide antioxidant. This additive package can be used in gasoline, fuel oils, heating oils and lubricating oils. The nitrogen-containing dispersant is the reaction product of a high molecular weight carboxylic acid with an alkylene polyamine while the antiwear agent is the reaction product of a phosphorus sulfide with an olefinic hydrocarbon. The antioxidant phosphorothionyl disulfides are derived from C C alkyl phenols.

2. Description of the Prior Art U.S. Pat. No. 3,394,179 teaches the use of phos phosulfurized hydrocarbons with high molecular weight carboxylic acid-polyamine ashless dispersants as additives for gas engine oils. The present invention is an improvement over that invention.

The use of phosphorothionyl disulfides derived from alkyl phenols as antioxidants in mineral oils is known. See U.S. Pat. No. 2,443,264. Preparation of such materials through the use of sulfoxides as an oxidizing agent is disclosed in U.S. Pat. No. 3,376,313. The use of such phosphorothionyl disulfide with other phosphoruscontaining materials such as ammonium phosphodithioates is also known in the art. See British Patent specifi cation l,27l,955.

SUMMARY OF THE lNV ENTlON lt has now been found that an additive package of su perior antioxidant and wear-preventing capabilities is comprised of the combination of (i) an ashless nitrogen-containing dispersant made by reaction of an alkylene polyamine with a monoor dicarboxylic acid or anhydride substituted with a C VC ,substantially hydrocarbon side chain. (ii) a phosphosulfurized olefin made by reaction of a terpene, petroleum fraction or a 5( )-2(l.()0() molecular weight C -C olefinic polymer with phosphorus sulfide and (iii) a phosphorothionyl disulfide of a C,C,,, alkyl phenol. Preferably. the'se additive packages are used in petroleum mineral oils hav ing viscosity indices between 50 and 110 and which are suitable for use as engine lubricants.

Although the above-noted 179 patent disclosed the use of an ashless additive for use in engine lubricating oils, the use of ash-containing lubricating oil additives has continued because it has been generally found that prior art ashless oils have been deficient in their ability to protect lubricated metal parts, particularly rings and cylinder liners, against excessive wear and scuffing. The additive packages of this invention are particularly useful in this regard. Furthermore, the components of the present package do not need to be intentionally prereacted as do those of the 179 patent.

lt has now been found that the ashless materials of the 179 patent can be further improved by combining them with a phosphorothionyl disulfide so as to make a package superior to the known ash-forming packages with respect to deposit formation and antiwear activity.

The desirability of using ashless additives is well known to the art in that, upon combustion, they prevent excessive engine deposits composed of ash-forming metal salts and burdening of the environment with unnecessary pollutants.

The additive packages of this invention are particularly useful in oils used to lubricate gas engines. Gas engine oils are subjectedto an environment particularly prone to cause oxidative degradation because the gas engines generally produce relatively high amounts of nitrogen oxide in the exhaust stream. Such exhaust streams are often passed through the oil sump and as is well known, nitrogen oxide can induce and/or catalyze oxidative deterioration of hydrocarbons. Therefore, it is particularly desirable that a gas engine oil be resistant to oxidative deterioration. Such oxidative deterioration of an oil shows up primarily as an increase in the viscosity of the 'oil. Under extreme conditions, the viscosity increases to a point where the oil can no longer satisfactorily lubricate the engine, It is believed that gas engines produce high nitrogen-oxide eshaust because for reasons of fuel efficiency, they are often operated at lean air/fuel ratios and conditions of spark advance which induced high combustion temperatures which tend to convert atmospheric nitrogen into corrosive nitrogen oxides.

ASHLESS, NITROGEN-CONTAINING DISPERSANTS The nitrogen-containing dispersant additives used in the present invention are generally those known in the art as sludge dispersants for crankcase motor oils. These dispersants include mineral oil-soluble salts, amides, imides and esters made from high molecular weight monoand dicarboxylic acids (and where they exist the corresponding acid anhydrides) and various amines or nitrogen-containing materials having amino nitrogen or heterocyclic nitrogen and at least one amido or hydroxy group capable of salt, amide, imide or ester formation.

These dispersants generally contain a long chain bydrocarbon group or groups attached to the acid, so the acid has a total of about 50 to 25f) carbon atoms, said acid being attached to the amine either through salt, imide, amide or ester groups. Usually, these dispersants are made by condensing a monocarboxylic acid or a dicarboxylic acid of anhydride, preferably a succinic acid producing material such as alkenyl succinic anhydride, with an amine or polyamine. Usually, the molar ratio of acid or anhydride to amine is between 1:1 to 5:1.

Monocarboxylic acid dispersants have been described in British Patent specification 983,040. Here, the high molecular weight monocarboxylic acid can be derived from a polyolefin, such as polyisobutylene, by oxidation with nitric acid or oxygen; or by the addition of halogen to the polyolefin followed by hydrolyzing and oxidation. The monocarboxylic acid may also be obtained by oxidizing a monohydric alcohol with potassium permanganate, or by reacting a halogenated polyolefin with a ketone.

Another method is taught in Belgian Patent 658,236 where a polyolefin, such as polymers of C to C monoolefin, e.g. polypropylene or polyisobutylene, is halogenated, e.g. chlorinated, and then condensed with an alpha, beta-unsaturated, monocarboxylic acid of from 3 to 8, preferably 3 to 4, carbon atoms, e.g. acrylic acid, alpha-methyl-acrylie acid (i.e., Z-methyl propenoic acid), crotonic, or isocrotonic acid, tiglic acid (alphamethyl crotonic acid), angelic acid, (alphamethylisocrotonic acid), sorbic acid, cinnamic acid, etc. Esters of such acids, e.g. ethyl methacrylate, may be employed if desired in place of the free acid.

Primarily because of its ready availability and low cost, the hydrocarbon portion of the mono-, or dicarboxylic acid or anhydride is preferably derived from a polymer of a C to C monoolefin, said polymer generally having between 50 and 250 carbon atoms. A particularly preferred polymer is polyisobutylene.

Polyalkyleneamines are usually used to make the dispersant. These polyalkyleneamines include those represented by the general formula:

wherein n is 2 to 3 and m is a number from 0 to 10.Specific compounds coming within the formula include diethylenetriamine, tetraethylenepentamine. dipropylenetriamine, octaethylenenonamine, and tetrapropylenepentamine', N,Ndi'(2-aminoethyl) ethylenediamine may also be used. Other aliphatic polyamino compounds that may be used are the N-aminoalkylpiperazines of the formula:

wherein n is a number from 2 to 3, and R is hydrogen or an aminoalkyl radical containing 2 to 3 carbon atoms. Specific examples include N-(2-aminoethyl) piperazine, N-(2-aminoisopropyl) piperazinc, and N,N-di-(2-aminoethyl) piperazine.

The use of mixtures of alkylene polyamines, mixtures of N-aminoalkyl piper-azines, and mixtures of the alkylene polyamines with the N-aminoalkyl piperazines is also contemplated, and the term aliphatic polyamine is intended to embrace all of these materials.

The reaction temperatures for amide formation will generally be in the range of from about 200 to 400F. In most cases, a narrower range of from about 250 to about 350F will be used. The reaction time will depend to some extent upon the reaction temperature. The composition of the reaction can be determined by measuring the amount of water or alcohol that is split off during the reaction. If desired, a water-entraining solvent, such as toluene, can be employed to remove the water as an azeotrope.

Representative dispersants, formed by reacting about equal molar amounts of polyisobutenyl succinic anhydride and a tetraethylenepentamine. are described in U.S. Pat. No. 3,202,678. Similar dispersants, but made by reacting a molar amount of alkenyl succinic anhydride with about two molar amounts of polyalkyleneamines, are described in U.S. Pat. No. 3,154,560. Other dispersants, using other molar ratios of alkenyl succinic anhydride and polyalkyleneamines, are described in U.S. Pat. No. 3,172,892. Still other dispersants of alkenyl succinic anhydride with other amines are described in U.S. Pat. Nos. 3,024,195, 3,024,237 (piperazine amines) and 3,219,666. An ester derivative is taught in Belgian Patent 662,875 where N-alkyl morpholinone esters, e.g. N-(Z-hydroxyethyl)-2-morpholinone, are formed by reaction with polyisobutylene succinic anhydride. The prior art also teaches that the alkenyl succinic polyamine type dispersants can be further modified by reacting a fatty acid, having from 1 to 22 carbon atoms, e.g. acetic acid, with the reaction product of the alkenyl succinic anhydride and polyamine (see U.S. Pat. No. 3,216,936).

Any of the nitrogen-containing dispersants described in any of the aforementioned patents can be used in the present invention.

THE PHOSPHOSULFURIZED OLEFINIC HYDROCARBON The preparation of phosphosulfurized hydrocarbons useful as antiwear agents is well known in the art and involves reacting a sulfide of phosphorus such as P 5 P 5 P 8 and the like, preferably P S with a hydrocarbon material such as a terpene, heavy petroleum fraction or polyolefin. A terpene is an unsaturated hydrocarbon having an empirical formula C l-l which is usually isolated from plant sources. The preparation of phosphosulfurized hydrocarbons is more fully described in U.S. Pat. Nos. 2,875,188 and 2,316,078.

Among the preferred hydrocarbon materials for treatment with phosphorus sulfides are olefin polymers having Staudinger molecular weights in the range of about 500 to about 20,000 and containing from 2 to 6 carbon atoms per olefin monomer. Polymers of ethylene, propylene, butylene, isobutylene or isoamylene may be employed. Particularly preferred are the polymers of butylene or isobutylene having Staudinger molecular weights in the range offrom about 600 to about 10,000 and still more particularly phosphosulfurized polybutene of about 800 to 1900 molecular weight. The term polybutene" is intended to embrace polymers of both butylene and isobutylene.

Phosphosulfurized hydrocarbons can be prepared by reacting a hydrocarbon base stock with from about 5 to 40 wt. percent of a sulfide of phosphorus, preferably with from about 10 to 20 wt. percent of phosphorus pentasulfide. The reaction is conducted under anhydrous conditions at temperatures from about to about 600F for from about /2 to about 15 hours. Similarly, low molecular weightolefins can be reacted with the above-described phosphorus sulfides. Such olefins include isobutylene, decene, dodecene, cetene, octadecene, cerotene and terpenes such as dipentene, terpolene and pinenes such as alpha pinenes. A particularly preferred phosphosulfurized olefin for use in this invention is that formed by the reaction of P 5 with alpha pinene.

THE PHOSPHOROTHIONYL DlSULFlDE The phosphorothionyl disulfides of this invention are derived from acids of the general formula in which R and R are each phenyl or C to C alkyl phenol groups, X, X and X are oxygen or sulfur, sulfur being preferred for X and oxygen being preferred for X and X The groups R and R are usually, but need not necessarily be, the same. Suitable specific R and R phenyl groups are tolyl, xylyl, nonyl phenyl, dodecyl phenyl, octadecyl'phenyl, dibutyl phenyl, butyl pentyl phenyl, dinonyl phenyl, etc.

The preferred thiophosphoric acids are the dithiophosphoric acids, i.e., ones where X and X are oxygen and X is sulfur. A particularly preferred dithiophosphoric acid is that in which R and R are nonyl phenyl groups.

The above'described thiophosphoric acids are easily converted into the disulfides used in this invention by oxidation. Air, oxygen, peroxides or sulfoxides, for example, can be used as the oxidant. Further details are contained in the above-noted British specification 1,271,955.

THE OILS OF THE PRESENT INVENTION The lubricating oils to which the additive package of the invention can be added include not only mineral lubricating oils, but synthetic oils also. The mineral lubricating oils may be of any type, including those derived from the ordinary paraffinic, naphthenic, asphaltic or mixed base mineral crude oils by suitable refining methods. Synthetic hydrocarbon lubricating oils can also be employed. Other useful synthetic oils include dibasic acid esters such as diZ-ethyl hexyl sebacate, carbonate esters, phosphate esters, halogenated hydrocarbons. polysilicones, polyglycols, glycol esters such as C oxo acid diesters of tetraethylene glycol and complex esters as for example the complex ester formed by the reaction of mole of sebacic acid with 2 moles of tetraethylene glycol and 2 moles of Z-ethyl hexanoic acid. Polyol esters, such as those made by the reaction of polyols (e.g., pentaerythritollhaving 3 to 6 hydroxyl groups with C, to C fatty acids can also be used.

In a preferred embodiment, the additive packages of this invention are used in a petroleum mineral oil having a viscosity index between about 50 and 110 and suitable for use in lubricating gas engines.

The additive package of this invention comprises 30 to 80, preferably 50 to -75 wt. percent of the abovedescribed ashless nitrogen-containing dispersant, 3.0 to 30, preferably 5 to 25 wt. percent of the abovedescribed phosphosulfurized olefinic hydrocarbon, and 3.0 to 30, preferably 5 to 25 wt. percent of the abovedescribed phosphorothionyl disulfides, all weight percents being based on the total weight of the package.

The additive packages of this invention are used in the above-described lubricating oils in the amounts of 1.0 to 15, preferably 2.5 to 7.5 wt. percent, based on the total weight of the oil formulation.

The additive packages of this invention. when combined with the aforesaid petroleum base oils, provide a lubricating oil particularly suited for use in gas engines. Such engines are internal combustion engines which utilize gaseous fuels such as methane, natural gas. town gas, synthesis gas, liquefied petroleum gas, etc. They are also very useful in the lubrication of diesel, gasoline, rotary and turbine engines.

The additive packages of this invention may also be employed in middle distillate fuels. Concentration ranges of from about 0.002 to about 2 wt. percent or more, generally from about 0.005 to about 0.2 wt. percent are employed. These petroleum distillate fuels generally boil in the range of fromabout 300 to about 900F. Typical of such fuels are No. l and No. 2 fuel oils that meet ASTM Specification D-396-48T, diesel fuels qualifying as Grades 1D. 2D and 4D of ASTM Specification D-975-5lT and various jet engine fuels.

Because they are ashless, these additives are particularly desirable for such fuels in that they do not give rise to glowing ashes nor deter from the burning qualities of the distillates. These additives may also be used in con- 5 junction with other prior art ashless additives for fuels, I such as polymers of acrylic or methacrylic acid esters,

high molecular weight aliphatic amines, etc.

The additive packages of this invention can also be employed, either along or in combination with other hydrocarbon-soluble additives, in jet fuels and gasolines in concentrations ranging from 0.00l to 1.0 wt. percent as detergent and/or rust preventive additives.

In any of the above-described fuel or lubricant compositions, other conventional additives may also be present, including dyes, pour point depressants, antiwear agents, e.g., tricresyl phosphate, zinc dialkyl dithiophosphates of 3 to 8 carbon atoms, antioxidants such as phenylalphamaphthylamine, tert. oetylphenol sulfide, bis-phenols such as 4,4-rnethylene bis (2,6-ditert. butylphenol), viscosity index improvers such as polymethacrylates, polyisobutylene, alkyl fumaratevinyl acetate copolymers, and the like, as well as other dispersants.

THE ASHLESS DlSPERSA NTS THE PHOSPHOSULFURIZED OLEFlN The phosphosulfurized olefin was prepared by reacting alpha pinene with phosphorus pentasulfide for several hours at a temperature ofabout l to 250C, the mixture being stirred and blown with nitrogen during the reaction to eliminate the hydrogen sulfide evolved.

To make the finished additive composition, the above-described P 8 treated alpha pinene was blended with a light mineral oil. The final formulation contained 60 to 65 wt. percent of phosphosulfurized alpha pinene with 40 to 35 wt. percent mineral oil. This formulation has a final phosphorus content of 4.96 wt. percent and a sulfur content of l3.l5 wt. percent.

THE PHOSPHOROTHIONYL DlSUl sFlDE The phosphorothionyl disulfide used in the evaluations described below was a derivative of nonyl phenol. A typical laboratory preparation of this disulfide is as follows:

a. Preparation of the Dithiophosphoric Acid A total of 968 g of nonyl phenol was heated with 222 g of phosphorus pentasulfide at l35-l45C for 30 to 60 minutes until all the phosphorus pentasulfide had dissolved. The product was dinonyl phenyl dithiophosphoric acid.

b. Preparation of Di-nonyl Phenyl Phosphorothionyl Disulfide The acid produced in (a) above was cooled to 30C and 300 ml of a paraffinic hydrocarbon solvent (b.p. 7090C) was added.

A total of 86 g of dimethyl sulfoxide was added with stirring and the temperature rose to about 55C. A Dean-Stark trap was fitted to the reaction vessel and ml water 90 percent theoretical amount) was collected on refluxing. The solvent and remaining byproducts were then removed by straight distillation at 50C with the pressure initially atmospheric and finally under reduced pressure at 15 mm Hg. leaving 1,280 g of product.

The disulfide obtained by this method had a TAN of 2 and an ASTM D-l30 copper corrosion (1% in mineral oil) of J2.

DESCRIPTION OF COMPARATIVE ADDITIVE COMPONENTS NOT OF THIS INVENTION To demonstrate the superior properties of the additives of the present invention in the below-described evaluation tests, certain comparative tests were carried out with known commercial additives. These additives are briefly described as follows:

Additive A-l was 4,4methylene bis(2,6-ditertiary butyl phenol) which is a commercial antioxidant.

Additive A-2 was very similar to Additive A-l except it contained polyas well as bis-di-tertiary butyl phenol.

Additive A-3 was the ammonium salt of dinonyl naphthalene sulfonic acid. It is known as a commercially available antioxidant.

Additive A-4 was a combination of 33.3 volume percent of a first oil concentrate containing an alkaline earth alkyl phenol sulfide and a second oil concentrate containing 40 volume percent of an alkaline earth organic sulfonate.

LUBRICANT STABILITY TEST (LST) PANEL COKER TEST This test is a modification ofthe standard panel coker test using a model C standard coker obtained from the Roxanna Machine Works of St. Louis, Missouri. The modifications are summarized as follows:

Table I Item Modified Standard Model C Oil Sump Temp.. F. 400 Not Controlled Sump Air 'Iempq F. 400 Not Controlled Sump Air Flow. ecJmin. 300 None Supplied Testing Range. F. sou-moo (100-700 Test Panel Material 32l s.s. Aluminum Venting of Sump. Special L'nrestrieted \'ent Baffle Test Period 8 Hours 8 Hours ENGINE TESTS L-l ENGINE TEST This test engine and the method used with it are described in US. Federal Test Method No. 791, Method No. 332 and also in the Institute of Petroleum (Great Britain) Standard for test petroleum and its products, IP 124/64. The L-l test is run on a single cylinder 4- cycle diesel engine normally asperated. Fuel of a sulfur content of 0.4 wt. percent is used and the test is run for 480 hours. Evaluations are in the range of wear. ring sticking and deposit.

L-38 ENGINE TEST The L-38 Engine Test is also known as CLR L-38 Engine Test and is designed to evaluate high temperature oxidation stability of the formulated lubricant oil. Such evaluations are based on piston varnish deposit and copperlead bearing corrosion observed during the test. In this test a single cylinder water cooled Labeco oil test engine is operated at 3,150 rpm. for 40 hours with the test oil formulation. The oil is maintained at 300F and cooling water is maintained at F. Cop per-lead connecting rod bearings are weighed before and after the test. Bearing weight loss (BWL) of 50 milligrams or less is desired. After the test, the piston is visually evaluated and a varnish value is assigned by comparison to varnish deposit pictorial standards having assigned values of l to 10 for the color and extent of varnish deposit. In this varnish value scale of l to 10, the value 10 represents a clean and varnish-free piston and the value 1 represents a substantially complete dark varnish coated piston.

HOMELITE ENGINE EXHAUST PORT PLUGGING TEST The Homelite Engine Export Port Plugging Test uses a Model 250 engine supplied by the Homelite Company of Port Chester, New York. This engine is the driving component of a two-cycle gasoline engineelectric generator unit capable of delivering approximately 1,800 watts. The engine is lubricated by a fueloil vapor which reaches all of the critical rubbing metal surfaces in the engine. The fuel and oil are charged directly to the gasoline tank in proportions of pint of oil per gallon of fuel. Fuel and oil are fed to the carburetor, vaporized and then drawn into the engine crankcase on the upward stroke of the piston. On the piston downward stroke, the fuel-oil-air mixture is forced past the piston underside through intake ports in the cylinder wall into the combustion chamber. Compression and ignition occur during the following piston upward stroke. The engine is operated at 3600:25 r.p.m. so as to deliver ll5i3V and 15.7:1 amperes. The exhaust ports are inspected after 50 hours of operation.

Due in part to the large quantities of lubricating oil vapor throughout the engine, engine deposits build up rapidly during operation. The deposits formed by several lubricants in the cylinder exhaust ports have been found to correlate on a demerit basis with similar deposits formed by the same oils in field operations.

CHEVROLET o-CYLlNDER GAS ENGINE TEST This engine test was carried out substantially as described by T. Lonstrup and J. W. Wilson in SAE Transactions 76 3267, 1967. Briefly. a 6-cylinder Chevrolet engine having a displacement of 250 cubic centimeters is operated at an engine speed of approximately 1,500 rpm. for a period of 250 hours using a natural gas carburetor and methane as fuel. At the end of the test, the engine is dismantled and various" parts are rated using a demerit system in which zero represents a perfectly clean part and 10 represents a maximum of deposits.

GE. SCUFF TEST The GE. Scuff Test uses a mechanical device wherein a segment of a piston ring is mounted so as to be in contact with a segement segment a cylinder wall liner. Pressure is applied to the rubbing ring against the cylinder liner by means of hydraulic cylinders. The ring is oscillated through a three inch stroke at 640 rpm. Pressure against the ring is applied in 6 preset increments to a maximum ring interface pressure of 4,160 psi. Lubrication to the ring cylinder liner innerface is supplied by 2 electrically driven positive displacement type pumps. Oil flow is increased with each increase in pressure. At least two minutes of oil flow is allowed before beginning the oscillation at each pressure increment. The test is carried out for 270 minutes. Then the cylinder liner segment is also determined by subtracting the final ring weight from that of the initial ring weight.

RESULTS OF LABORATORY EVALUATlONS The formulations shown in Table 2 are evaluated in a series of the above-described laboratory tests. The base oil used was a severely hydrofined, phenolextracted SAE grade 30 oil having a viscosity at 2l0F of 59.2 SUS. a viscosity at lF of 5.28 SUS and a viscosity index of 66.5.

Table 2 which is representative of the present invention. Sim i larly, the ashforming composition of Control l produced excessive deposits in the panel coker test and showed further viscosity increases in the nitrogen oxidation test.

The oil formulation of Control 2, which was made from the above-described dinonyll naphthalene sulfo nate ammonium salt (Additive A-3) produced a viscosity increase twice that of Example 1 in the LST and a viscosity increase of more than 6 times that of Example 1 in the nitro-oxidation test. This is despite the fact that the composition of Control 2 contains 2 out ofthe 3 additives used in the formulation of Example 1. Thus, by merely replacing one of the components of the present invention with the material not within the scope of the present invention, a composition of significantly lesser effectiveness is produced.

Controls 3 and 4, which each contain one of the above-described bisphenol commercial antioxidants that the compositions ofthis invention are significantly,

better in their ability to protect the oil against oxidation than our compositions made of various prior art materials in combination with some but not all of the components of the present invention.

Laboratory Bench Test Data produced a viscosity increase in the LST which was some times that of the composition of Example 1 Ex. Control Control Control Control Control Control Material in base oil 1 l 2 3 4 6 Additive A-4, wt. 71 3.6 Dispersant D-2, wt. "/1 2.5 3.0 3.0 7..5 Dispersant D-l, wt. It 3.0 3.0 Phosphorothionyl disulfide, wt. '70 0.5 0.5 l 0 Phosphosulfurized olefin, wt. 7a 0.5 l.0 Additive A-3, wt. ,4 0.5 Additive A-l, wt. "/1 0.5 Additive A-Z, wt. 7: 0.5 LST (340, 23 hr) Vise inc 7: 5 74 l0 I2] 364 23 l3 Panel Coker Test (3 hr) Wt deposits (600F) mg ll l9 3 110 68 ll 12 Wt deposits (650"F) mg 69 98 84 Nitro-oxidation Test (340F, 7 hr) Visc inc "/4 3 43 29 18 IR abs/cm 5.3 (oxid) 24 5] l6 31 37 6.l (nitr) l7 23' 5 l5 29 From an examination of the data in Table 2, it can be ENOlNE TESTS seen that ontrol I, an ash-lot mtng lubricant composition formulated from the above-described additive A-4, Th formulations of Example 1 and Controls 1 a d 2 were tested in a series of the above-described engine tests. Results are shown in Table 3.

Table 3 Preliminary Engine Test Data (l) at 240 hrs. (2) at 60 hrs.

From an examination of the data contained in Table 3. it can be seen that the ash-forming composition of the prior art (Control 1 produces copper-lead-bearing losses times that produced by the formulation of Example l and viscosity increases some lOO times that of the formulation of Example I when evaluated in the L-38 test.

Similarly. from an examination ofthe performance of the formulations of Example 1 and of Control 2 in the Homelite Engine Test, it can be seen that Example 1 gives a good piston rating while the control formulation gives a dirty piston rating. These results again demonstrate that compositions formulated in accordance with the present invention are more effective in maintaining engine cleanliness and reducing wear losses than those of prior art ash-forming materials or those formulated from some but not all of the ashless components of the invention.

The formulations of Example 1 and Controls l and 2 were also evaluated in a gas engine test. The results are shown in Table 4.

As can be seen from the data in Table 4, the ashforming package of the prior art (Control 1) gave almost 50 times the amount of con-rod bearing weight loss and ring weight loss as did that of Example 1. The superior wear protection provided by the package of this invention is evident from a comparison of the various top ring weight losses obtained with the various package. That obtained with Example l is one'sixth that obtained with the next best package (Control 2). Similarly, the viscosity increase ofthe Control 1 oil was more than 8 times that of the increase observed with the oil of Example 1 demonstrating that the formulation of Example 1 satisfactorily controls the oxidation of the oil. Similarly, the viscosity increase of Control 2 is three times that of Example 1 further demonstrating the effectiveness of Example 1 in protecting an oil against oxidative deterioration and corresponding viscosity increases.

Control 2 performs similarly in this test to Example 1 except that with it engine cleanliness is somewhat less.

In the abovedescribed G.E. Scuff Test, formulations prepared in accordance with this invention were compared with formulations containing some. but not all,

of the components of the additive packages of this invention.

Table 4 250 Hour (ias Engine Test Results Engine Ex Control Control Base 4() Cleanliness (merits) l l 1 Oil Overall average 9.5 9.0 9.2 (1.7 Ring Zone 9.1 8.4 8.4 (v.4 Piston \"arnish l(l.(l 9.4 9.4 4.8 Exhaust Valve Stems 7.9 7.8 7.8 5.8 Comp. ring grooves 8.5 8.0 8.0 5.4 Oil res. sludge 9.5 8.5 9.8 7.0

Wear. mg No.3 con-rod (Cu/Pb] I26 5636 8K) 3] l" 'lotal top ring wt loss 10 47a 62 2| Top ring inc. (in. l()l (i "9 6 I4 Used Oil 7! visc. inc. 4 39 I2 I08 "71 Pl. 0.8 1.4 0.5 2.3 Oxid. abs/cm l7 86 15 I Nitration. abs/cm ll 26 l7 38 Final pH 3.8 4.2 2.] 2.9 gs TAN 1.9 3.3 1.5 7.8 Fe. ppm 26 39 22 Table 5 G.E. Scuff Test Data Example Control Control Control Base Material 1 7 8 9 Oil Dispersant D-l. wt. 3.0 3.0 3.0 5.0 Phosphosulfurized Olefin Wt. 7a 0.5 0.5 Phosphorothionyl disulfide Wt. 7! 0.5 0.5 Scuff Rating Demerits (l0=max.) 3 5 6 8 5 Average Ring Wt. Loss. mgs 2.3 3.2 2.6 4.2 5.1

As can be seen from the data in Table 5, the formulation of Example 1 containing the additive package of this invention, gave significantly lower scuff demerit ratings and ring weight losses than did formulations containing only two of the components of the present invention. It can also be seen that while the base oil gave only a moderately severe scuffing rating, the addition of dispersant 1 to it increased it (Controls 8 and 9). The addition of one of the two other components to a dispersant-containing formulation only brings the scuff-rating back to the base level. Surprisingly, however, the addition of both other components to the dispersantcontaining formulation (Example 1) pro-- vides a total formulation of substantially improved scuff rating. It is also observed that this formulation provides the best wear protection as measured by ring weight loss. This conforms the findings discussed above in relation to Table 4. These data again illustrate that the packages of this invention provide greater wear protection than do similar compositions not within the scope of the invention.

What is claimed is:

1. An additive package for use in lubricating oil for an internal combustion engine which comprises in combination 30 to 80 wt. percent of a nitrogencontaining ashless dispersant, 3.0 to 30 wt. percent of a phosphosulfurized olefinic hydrocarbon and 3.0 to 30 wt. percent of a phosphorothionyl disulfide of phenol or of a C C alkyl phenol, said nitrogen-containing ashless dispersant being selected from the class consisting of salts, amides, and imides derived by condensation of an aliphatic hydrocarbyl polyamine with a hydrocarbyl monocarboxylic acid, hydrocarbyl dicarboxylic acid, or hydrocarbyl acid anhydride, said acid or acid anhydride having a total of from about 50 to 250 carbon atoms.

2. A lubricating oil for an internal combustion engine comprising a major proportion of oil and l.() to weight percent based on the total oil formulation ofthe additive package of claim 1.

3. A lubricating oil as claimed in claim 2 wherein the oil has a viscosity index between 50 and l 10.

4. The additive package of claim 1 wherein the phosphosulfurized olefinic hydrocarbon is prepared by the reaction of a phosphorus sulfide with a terpene.

5. The additive package of claim 1 wherein the nitrogen-containing dispersant is formed by the reaction of an alkenyl succinic anhydride with an alkylene polyamine selected from the group consisting of compounds of the general formula wherein n is 2 or 3 and m is a number from 0 to 10; and

CHr-CHi wherein n is as defined above and R is a hydrogen atom or an amino alkyl radical of 2 to .3 carbon atoms.

6. An additive package as claimed in claim 5 wherein said dispersant is made by reacting said anhydride with said polyamine in a molar ratio between 1:1 to 5:1 anhydride to polyamine.

7. An additive package as claimed in claim 5 wherein said anhydride contains a polyisobutenyl group of50 to 250 carbon atoms.

8. An additive package for use :in an oil formulation which comprises 50 to wt. percent of an ashless dispersant made by the reaction of a polyisobutenyl succinic anhydride with a tetraethylene pentaamine, 5 to 25 wt. percent of an antioxidant made from the reaction of P 5 with alpha pinene and 5 to 25 wt. percent of a phosphorothionyl disulfide of a nonyl phenol.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3,850,822 Dated November 26, 1974 Patent No.

inventofls) David E. Steere and Edwin C. Younghouse It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

0n the front page, first column, under data element identifier [75] the text should read as follows:

Signed and sealed this 4th day of a February. 1975.

(SEAL) Attest:

McCOY M. GIBSON JR. Arresting Officer Y C. MARSHALL DANN Commissioner of Patents F ORM PO-105O (10-69) USCIOMM-DC 60376-P69 uvs. GOVERNMENT PRINTING orrlcl: Ian o-au-su,

Claims (8)

1. AN ADDITIVE PACKAGE FOR USE IN LUBRICATING OIL FOR AN INTERNAL COMBUSTION ENGINE WHICH COMPRISES IN COMBINATION 30 TO 80 WT. PERCENT OF A NITROGEN-CONTAINING ASHLESS DISPERSANT, 3.0 TO 30 WT. PERCENT OF A PHOSPHOSULFURIZED OLEFINIC HYDROCARBON AND 3.0 TO 30 WT. PERCENT OF A PHOSPHOROTHIONYL DISULFIDE OF PHENOL OR OF A C1-C18 ALKYL PHENOL, SAID NITROGENCONTAINING ASHLESS DISPERSANT BEING SELECTED FROM THE CLASS CONSISTING OF SALTS, AMIDES, AND IMIDES DERIVED BY CONDENSATION OF AN ALIPHATIC HYDROCARBYL POLYAMIDE WITH A HYDROCARBYL MONOCARBOXYLIC ACID, HYDROCARBYL DICARBOXYLIC ACID, OR HYDROCARBYL ACID ANHYDRIDE, SAID ACID OR ACID ANHYDRIDE HAVING A TOTAL OF FROM ABOUT 50 TO 250 CARBON ATOMS.

2. A lubricating oil for an internal combustion engine comprising a major proportion of oil and 1.0 to 15 weight percent based on the total oil formulation of the additive package of claim 1.

3. A lubricating oil as claimed in claim 2 wherein the oil has a viscosity index between 50 and 110.

4. The additive package of claim 1 wherein the phosphosulfurized olefinic hydrocarbon is prepared by the reaction of a phosphorus sulfide with a terpene.

5. The additive package of claim 1 wherein the nitrogen-containing dispersant is formed by the reaction of an alkenyl succinic anhydride with an alkylene polyamine selected from the group consisting of compounds of the general formula NH2(CH2)n(NH(CH2)n)mNH2 wherein n is 2 or 3 and m is a number from 0 to 10; and

6. An additive package as claimed in claim 5 wherein said dispersant is made by reacting said anhydride with said polyamine in a molar ratio between 1:1 to 5:1 anhydride to polyamine.

7. An additive package as claimed in claim 5 wherein said anhydride contains a polyisobutenyl group of 50 to 250 carbon atoms.

8. An additive package for use in an oil formulation which comprises 50 to 75 wt. percent of an ashless dispersant made by the reaction of a polyisobutenyl succinic anhydride with a tetraethylene pentaamine, 5 to 25 wt. percent of an antioxidant made from the reaction of P2S5 with alpha pinene and 5 to 25 wt. percent of a phosphorothionyl disulfide of a nonyl phenol.