US3003958A

US3003958A - Lubricating oil additives and lubricating oil compositions

Info

Publication number: US3003958A
Application number: US688782A
Authority: US
Inventors: Carleton B Scott; William L Wasley
Original assignee: Union Oil Company of California
Current assignee: Union Oil Company of California
Priority date: 1957-10-07
Filing date: 1957-10-07
Publication date: 1961-10-10
Anticipated expiration: 1978-10-10

Description

United States Patent LUBRICATING OIL ADDITIVES AND LUBRICAT- ING OIL CQMPOSITIONS Carleton B. Scott, Pomona, and William L. Wasley, Santa Ana, Calif., assignors to Union Oil Company of California, Los Angeles, Calif., a corporation of California No Drawing. Filed Oct. 7, 1957, Ser. No. 688,782 17 Claims. (Cl. 25232.7)

This invention relates to lubricating oil additives adapted to being diluted with mineral lubricating oils to produce lubricating oil compositions. It ftu'ther relates to lubricating oils containing such additives. More particularly the invention relates to additive materials suitable .for addition to lubricating oils to produce high viscosity index lubricating oil compositions having good detergency and anticorrosion characteristics. It relates also to lubricating oils containing these additives with or without added anticorrosion, antirust, antioxidation agents, and the like. This is a continuation-in-part of our copending application, Serial No. 602,074, filed August 3, 1956, now US. Patent No. 2,897,228.

Internal combustion engines, both of the spark ignition and compression ignition types, are constantly being improved With respect to increased eliiciency and greater horsepower output, arnong other things. With these changes, improvements in lubricating oils suitable for use in these engines are necessary. Among the requisite characteristics of lubricating oil compositions, suitable for use in the present day engines of the types mentioned, are high viscosity index, detergency and anticorrosion properties. The viscosity index (V.I.) of an oil is a measure of the extent to which the viscosity of the oil varies with temperature, a high V.I. oil being one whose viscosity changes only slightly with change in temperature. The use of various polymeric materials to improve the V.I. of lubricating oils is known.

The property of detergency, which is one of the requisite characteristics of lubricating oil, is one of preventing formation of carbonaceous and/or varnish-like deposits from accumulating on the various internal parts of the engine, e.g. on pistons, cylinder walls, in piston ring grooves, in hydraulic valve litters, and the like. Such deposits are particularly difficult to prevent and require the use of an exceptionally active detergent additive particularly in present day automotive engines where part or most of the driving is so-called stop-and-go driving such as is encountered in city driving.

The property of anticorrosiveness is one of preventing the formation and/or accumulation within the oil of acidic bodies which attack the metal parts of the engine under conditions of use.

Although for many years lubricating oils designed for use in internal combustion engines have contained various additive materials to impart the characteristics referred to above, the extent of protection obtained by such additives leaves something to be desired in the modern, high horsepower output engines, particularly when these engines are operated under stopand-go driving conditions. Many attempts have been made to prepare a single additive material which is capable of imparting-all of the required characteristics to the base oil. However, for the most part, such additives have not proved entirely satisfactory. g

It is an object of this invention to provide a lubricating oil additive capable of imparting high viscosity index and high detergency to a mineral lubricating oil.

Another object of this invention is to provide an additive composition capable of imparting high V.I., high detergency and exceptional anticorrosion characteristics to a mineral lubricating oil.

Another object of this invention is to provide a lubrimetaphosphate.

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2 eating oil containing an additive material capable of imparting the characteristics of high V.I., detergency antico-rrosiveness.

A further object of this invention is to provide a lubrieating oil having all of the characteristics described which consists of a mineral lubricating oil containing a single additive material which is eifective in imparting all of the described characteristics to said oil.

Other and related objects wlll be apparent from the following description of the invention.

The additive material adapted for addition to mineral lubricating oil to impart good detergency is prepared by reacting a monoolefin polymer or a monoolefin-diolefiu copolymer having an average molecular weight of between about 5,000 and about 50,000, preferably between about 10,000 and about 30,000, with an alkyl trithio- The resulting reaction product is then neutralized with a basic compound of an alkali metal or preferably an alkaline earth metal. When anticorrosion characteristics are particularly desired, the product may be super-based as will be described hereinbelow. The additive material described very briefly above may be added to lubricating oil to produce an oil having the characteristics described herein.

Describing our invention more specifically the polymer or copolymer to be used in the preparation of the additive will be a homopolymer of a monoolefin containing 3-6 carbon atoms or a polymer of a mixture ct monoolefins containing from 36 carbon atoms in the molecule, or it may be a copolymer of a monoolefin containing 3-6 carbon atoms with a conjugated diolefin containing from 4-7 carbon atoms in the molecule. The ratio of monoolefin to diolefin to be employed in preparing the copolymer will preferably be between and 99.5 parts of the monoolefin to between 0.5, and 10 parts of the diolefin. Monoolefins which may be used to prepare the polymers and copolymers include propylene, normal butylene, isobutylene, 2methyl-butenel, Z-ethyl-butene l, and similar olefins containing 3-6 carbon atoms. Of these olefins the isoor branched-chain monoolefins are preferred and isobutylene is particularly preferred.

Polyolefins which may be used to copolymerize with the monoolefins include isoprene, butadiene, 2-methyl -butadiene-l,3, 2-3-dirnethyl butadiene-l,3, hexadiene-2,4, cyclo-pentadiene, piperylene and the like having 4-7 car bon atoms. Of the polyolefins, isoprene and butadiene are preferred. Of the various polymeric materials those prepared by copolymerizing isobutylene and isoprene are particularly preferred.

The monoand diolefins may be employed in relatively pure form, in which case they are usually diluted with an inert liquid polymerization medium, or they may be employed in admixture with inert components. For example, in preparing polyisobutylene for use in accordance with the invention, the isobutylene may be provided in relatively pure form or it may be employed in the form of a mixture of isobutylene and butane, such as is produced as a by-product from petroleum refining processes. Similarly in preparing copolymers the diolefin as well as the monoolefin may be employed in admixture with inert constituents.

The polymerization reaction is eifected at low temperatures, e.g., at from about --20 C. to about C., preferably from about 50 C. to about 80 C., under the influence of a Friedel-Crafts type catalyst such as aluminum chloride, aluminum bromide, zinc chloride,

boron trifluoride, titanium tetrachloride, etc., and preferably .in the presence of an inert liquid hydrocarbon or halogenated hydrocarbon reaction medium. In general, conventional techniques such as those described in US. Patent No. 2,356,128 are employed, and the various process variables are controlled in the known manner to produce a polymeric product whose molecular weight is between about 5,000 and about 50,000, preferably be tween about 10,000 and about 30,000. Conveniently, the reaction is carried out continuously in a tubular reactor which may take the form of a copper coil provided with exterior cooling means capable of maintaining the desired low polymerization temperature. The monoolefin, or mixture of monoolefin and diolefin, and the liquid reaction medium, either as separate entities or as a previously-formed mixture, are continuously introduced into the refrigerated coil. At a point within the coil where the olefinic reactant and the reaction medium have been thoroughly mixed and/or cooled, for example, to about 75 C., there is introduced a stream of catalyst, e.g., a mixture of boron trifluoride in methane, ethane, propane, or other inert diluent, containing 5 to 50 parts of diluent per part of boron trifiuoride. The polymerization reaction is exothermic, and the reaction temperature and reaction rate (and hence also the molecular weight of the product) can readily be controlled by suitably varying the rate of catalyst addition and/ or the catalyst concentration. Generally, between about 0.1 and about 3 parts by weight of catalyst are provided per 100 parts by weight of polymerizable olefin. The polymerization may be carried to completion, i.e., to point of maximum molecular weight of the product under the particular conditions employed, or it may be stopped at any desired intermediate point by quenching the reaction by the addition of an alcohol, ether or ketone. As stated, the polymerization reaction should be so controlled, either by suitably selecting the reaction temperature, the amount of inert liquid reaction medium present, the identity, concentration and rate of addition of the catalyst, by use of a quenching agent, or by a combination of these means, to stop the reaction at the desired point so as to obtain a polymeric product having an average molecular weight between about 5,000 and about 50,000. Processwise, there is no distinction between the homopolymers and copolymers, i.e., the same techniques, reaction conditions, catalysts, reaction media, etc. are employed regardless of whether the product being prepared is a homopolymer of a monoolefin or a copolymer thereof with a diolefin. The most desirable copolymers contain from about 0.005 to about 0.1, preferably from about 0.01 to about 0.05, part of the diolefin per part of the monoolefin.

Upon completion of the polymerization reaction, the polymeric product is obtained in the form of a viscous solution of the same in the liquid reaction medium. the polymer is to be stored for any appreciable period of time before being reacted with an alkyl trithiometaphosphate, it is preferably washed several times with water to remove any catalyst and a portion of the solvent is distilled off to strip off traces of water and unpolymerized olefinic material.

The alkyl trithiometaphosphates, which are employed to react with the polymers and copolymers described, are the methyl trithiometaphosphate and ethyl trithiometaphosphate. These compounds are made by reacting phosphorus pentasulfide with methyl or ethyl mercaptan or with trimethyl or triethyl tetrathioorthophosphate. In preparing the compounds with methyl or ethyl mercaptan, a mixture of the phosphorus pentasulfide and at least about 4 molecular equivalents of the desired mercaptan are reacted at temperatures of 90200 C. for 2 to 40 hours under sufiicient pressure to maintain the reactants in the liquid phase. Reaction may be carried out in an inert reaction medium such as benzene, toluene, or the like. In preparing these same compounds by reacting phosphorus pentasulfide with trimethyl or triethyl tetrathioorthophosphate, the reaction is effected at temperatures between about 90 C. and 200 C. for 2 to 20 hours. In this instance also it is preferable to carry out the reaction in the presence of an inert reaction medium such as benzene, toluene or xylene.

In reacting the hydrocarbon polymers and copolymers described hereinabove with methyl or ethyl trithiometaphosphates 1 part of the polymeric material in solution in a diluent, e.g. naphtha, toluene, xylene or the like or preferably a light mineral lubricating oil such as 90 neutral oil (a light neutral lubricating oil having a viscosity of about 38 seconds Saybolt Universal at 210 F. and a viscosity index of about 84) is heated with 0.01 to 0.15 part of methyl or ethyl trithiometaphosphate at temperatures of 20 C. to 190 C. for 2 to 10 hours depending on the reactivity of the polymer or copolymer. The product may be neutralized and/or super based directly or may first be filtered using any well known filter aid such as a clay. In the event one of the hydrocarbon diluents mentioned is used the diluent may be removed by evaporation to obtain the reaction product or 90 neutral oil or like oil may be added prior to evaporation of the diluent.

The acidic reaction product may be reacted with a chemically equivalent amount of alkali metal base or preferably an alkaline earth metal base at elevated temperatures to effect neutralization and the resulting product filtered hot through a filter aid to obtain the additive in the form of oil concentrate. This concentrate will preferably contain 15% to 50% by weight of the neutralized reaction product in light mineral lubricating oil.

Preferably the acidic reaction product either before or after neutralization will be reacted with an amount of base sufiicient to produce a super based material. The amount of excess base will be between 1.1 and 3.5 equivalents per equivalent of acidic reaction product or between 0.1 and 2.5 equivalents per equivalent of neutralized reaction product.

The super basing is eflected in the presence of 0.05 to 0.4 part by weight of an alkyl substituted phenol having between about 4 and 5 and about 12 side-chain carbon atoms. Phenols suitable for this purpose include tertbutylphenol, isobutylcresol, n-octylphenol, mixed nonyl phenols, mixed dodecylphenols, dihexylphenol, etc. The mixture of acidic or neutralized phosphorusand sulfurcontaining reaction product, and phenol is heated to between 100 C. and 180 C. and the metal base is added over a period of 1 to 4 hours. A small amount of water is preferably added along with the base. After reaction is complete the mixture is heated for an additional 1 to 4 hours at about 110 C. to 180 C. to insure completion of the reaction and dehydration of the reaction product. Any basic compound of any of the alkaline earth metals, e.g., the oxides, hydroxides, carbonates, etc., of calcium, barium, or strontium, may be employed, but the oxide and hydroxide of barium are preferred. If desired, a combination of such bases may be employed, e.g., one metal base may be employed to neutralize the acidic 1 reaction product and another metal base may be employed to provide the desired alkaline reserve. Also, if desired, an alkali metal base such as sodium or potassium hydroxide or carbonate may be employed to neutralize the acidic reaction product and an alkaline earth metal base employed to provide the alkaline reserve.

Following the above treatment sufficient light mineral lubricating oil is added to give an additive concentrate containing 15% to 50% by weight of additive in oil.

In preparing the finished mineral lubricating oil of this invention the additive concentrate or additive in any form, such as pure additive product, is dissolved in or mixed with mineral lubricating oil to give an oil containing from about 1 to about 10% by weight of additive. Since the additive is oil-soluble it is merely necessary to add the additive or additive concentrate to the oil with mixing to obtain the finished lubricating oil. This may be accomplished at ordinary or elevated temperatures. The lubricating oil is preferably a solvent treated and dewaxed mineral lubricating oil fraction. By solvent treated is meant extracted with a selective solvent which selectively dissolves and removes the more aromatic portion of the petroleum fraction. Solvents and methods of solvent treating are well known in the art and need not be further described. Oils having viscosity indexes above about 80 are preferred but not essential since the additives described herein will impart improved V.I., detergency and anticorrosion characteristics to substantially any mineral lubricating oil.

Lubricating oils of this invention have been tested in a standard 1954 Chevrolet Power-Glide engine. In this test the engine is run for a total of 54 hours under varying conditions of load and temperature. The engine is operated for 2 hours under the conditions set forth in column A, below, then for 2 hours under the conditions set forth in column B, and finally for 2 hours under the conditions set forth in column C. This cycle is repeated 16 times, and the engine is disassembled and inspected for general condition and cleanliness.

TEST CONDITIONS Speed, rpm... Load, lbs Brake H. P Water Temp;

F. in.

F. out Oil Temp, F

The apparatus consists of 18 'feet of 0.25-inch copper tubing in the form of a coil mounted in a Dry Ice and acetone bath. The inlet end of the coil is equipped with two fittings through which monomeric olefin and solvent can be introduced into the coil. A second'fitting for the introduction of catalyst is positioned about 14 feet from the inlet end of the coil, and the outlet end of the coil feeds into a receiver. Suitable throttling valves, flow meters and associated equipment are provided for controlling the rate at which the olefin, solvent and catalyst are introduced into the coil, and thermocouples are provided for determining the temperature of the reaction mixture within the coil.

In a typical polymer preparation, isobutylene and pentane are introduced into the coil at rates of about 400 parts and about 1300 parts per hour, respectively. The catalyst, consisting of a mixture of 1 part of boron trifiuoride and 20 parts of propane, is introduced at a rate of about 1.5 parts per hour. At these flow rates, the temperature of the reaction mixture is about -65 C. to 75 C., and the reaction time is about 1.5 minutes. The product collected in the receiver is a pentane solution (of about 23% concentration) of an isobutylene polymer having an average molecular weight of about 25,000. This solution is concentrated'to about 35% by distilling off the required amount of'solvent.

Approximately 4,000 parts of the 35 polyisobutylene solution is then diluted with 1400 parts of 90 neutral oil, and is heated to about 150 C. and blown with nitrogen to remove the pentane solvent. To this solution of polymer is slowly added 140 par-ts of methyl trithiometaphosphate while heating the mixture at 150 C. for about 2 hours. Following the addition of metaphosphate the mixture is heated for an additional 4 hours at about the same temperature and then filtered hot.

One hundred parts of the product so obtained is mixed with 10 parts of n-hexylphenol and heated with stirring to 135 C., after which there is added 17.5 parts of barium hydroxide pentahydrate over a period of 1 hour. Heating is continued for about 4 hours, during which about 13 parts of water are added. The product is dehydrated by heating to 165 C. after which it is diluted with about 100 parts of neutral oil and filtered through diatornaceous earth to obtain a finished additive concentrate.

A lubricating oil is prepared by dissolving 10 parts of the additive concentrate in parts of a mineral oil consisting of equal parts of 90 neutral oil and 300 neutral Oil. The 300 neutral oil is an oil similar to 90 neutral oil described hereinabove except that it has a Saybolt Universal Viscosity at 100 F. of about 326 seconds and at 210 F. of about 52.5 seconds and a VI. of 86. The above oil, having a VI. of about 135, in the Chevrolet engine test shows a detergency rating of 90. The base oil, i.e. the mixture of 90 neutral and 300 neutral oil has a detergency rating of 60.

Example 11 Example I is repeated using ethyl trithiometaphosphate in place of methyl trithiornetaphosphate. The results are substantially identical to those of Example I.

Example III The polymerization procedure of Example I is followed except that suificient isoprene is dissolved in the pentane solvent so that the polymeric product obtained is a 35 pentane solution of a 97-to-3 copolymer of isobutylene and isoprene. Approximately 4,000 parts of this copolymer solution are admixed with 1400 parts of 90 neutral oil, and the resulting mixture is heated at about C. while blowing with nitrogen to remove the pentane sol vent. The resulting product is then admixed with 140 parts of methyl trithiometaphosphate and the temperature is increased to about C. and held there for about 6 hours. The acidic product is then filtered and cooled.

A 100-part portion of the product so obtained is mixed with 4 parts of octylphenol and heated to 130 C. while 17.5 parts of barium hydroxide pentahydrate are added over a period of 1 hour. Heating is continued for about 4.5 hours during which. time 12.5 parts of water are added to replace that lost by evaporation. The product is diluted with 100 parts of 90 neutral oil and filtered to obtain an additive concentrate. A lubricating oil is prepared by dissolving 10 parts of the additive concentrate in 100 parts of a mixture of equal parts of 90 neutral and 300 neutral oil. This lubricating oil has a V.'I. of 138 and a detergency rating of 91 in the Chevrolet engine test.

Example IV Example III is repeated using calcium hydroxide in place of barium hydroxide to neutralize and super base the acid reaction product of copolymer and methyl trithiometaphosphate. I

A lubricating oil prepared in the manner described in Example 111 has a detergency rating of 90.

Example V Example VI Example III is repeated except that the acidic product I is simply neutralized with barium hydroxide pentahydrate in the absence of alkyl phenol. The additive concentra-te is used to prepare alu-bricating oil using an SAE.

10 solvent-treated and dewaxed Western parafiinic min- 7 eral lubricating oil and sufiicient of the concentrate to impart an additive concentration of 3% by weight. This lubricating oil has a detergency rating of 87.

Other modes of applying the principle of our invention may be employed instead of those explained, change being made as regards the methods or materials em ployed, provided the compositions stated by any of the following claims, or the equivalent of such stated compositions, be obtained.

We claim:

1. A lubricating oil additive composition adapted for addition to mineral lubricating oil to produce a lubricating oil composition having high viscosity index, detergent and anticorrosion characteristics, said additive composition consisting essentially of a mineral lubricating oil containing between about 15% and about 50% by weight of a product obtained by reacting 1.0 part of a hydrocarbon polymer selected from the class consisting of the homopolymers of monoolefins containing from 3 to 6 carbon atoms, and copolymers of said monoolefins with between about 0.005 and about 0.1 part by weight of a conjugated diolefin containing from 4 to 7 carbon atoms, said polymer having an average molecular weight between 5,000 and 50,000, said hydrocarbon polymer being prepared at a temperature between 20 C. and -100 C. using a Friedel-Crafts catalyst, with between about 0.01 and about 0.15 part of a compound selected from the class consisting of methyl trithiometaphosphate and ethyl trithiometaphosphate, at a temperature between about 20 C. and about 190 C. for between about 2 and about hours to produce an acidic phosphorus and sulfur-containing reaction product and neutralizing the last named reaction product with a metal base of the class consisting of the alkali and alkaline earth metal bases.

2. A lubricating oil composition consisting essentially of a mineral lubricating oil having dissolved therein sufiicient of the additive composition defined by claim 1 to impart to said lubricating oil between about 1% and about 10% of additive by weight, said amount being sufiicient to enhance substantially the viscosity index, detergent and anticorrosion characteristics of said oil.

3. A lubricating oil additive composition adapted for addition to mineral lubricating oil to produce a lubricating oil composition having high viscosity index, detergent and anticorrosion characteristics, said additive composition consisting essentially of a mineral lubricating oil containing between about and about 50% by weight of a product obtained by reacting 1.0 part of a hydrocarbon polymer selected from the class consisting of the homopolymers of monoolefins containing from 3 to 6carbon atoms, and copolymers of said monoolefins with between about 0.005 and about 0.1 part by weight of a conjugated diolefin containing from 4 to 7 carbon atoms, said polymer having an average molecular weight between 5,000 and 50,000, said hydrocarbon polymer being prepared at a temperature between C. and -100 C. using a Friedel-Crafts catalyst, with between about 0.01 and about 0.15 part of a compound selected fromthe class consisting of methyl trithiometraphosphate and ethyl trithiometaphosphate, at a temperature between about 20 C. and about 190 C. for between about 2 and about 10 hours to produce an acidic phosphorus and sulfur-containing reaction product, and reacting the product so obtained with between about 1.1 and about 3.5 equivalents of an alkaline earth metal base per equivalent of said acid reaction product, together with between about 0.05 to about 0.4 part by weight per part by weight of acidic reaction product of an alkyl substituted phenol having from 4 to 12 side chain carbon atoms. V

4. A lubricating oil additive composition according to claim 3 in which said compound is methyl trithiometaphosphate.

5. A lubricating oil additive composition according to 8 claim 3 in which said compound is ethyl trithiometaphosphate.

6. A lubricating oil additive composition according to claim 3 in which said alkaline earth metal base is barium hydroxide.

7. A lubricating oil additive composition according to claim 3 in which said polymer is a polyisobutylene having an average molecular weight between about 10,000 and about 30,000.

8. A lubricating oil additive composition according to claim 3 in which said polymer is a copolymer of isobutylene and isoprene having an average molecular weight between about 10,000 and about 30,000.

9. A lubricating oil composition consisting essentially of a mineral lubricating oil having dissolved therein sufiicient of the additive composition defined by claim 3 to impart to said lubricating oil between about 1% and about 10% of additive by weight, said amount being sufficient to enhance substantially the viscosity index, detergent and anticorrosion characteristics of said oil.

10. A lubricating oil composition consisting essentially of a mineral lubricating oil having dissolved therein sufiicient of the additive composition defined by claim 4 to impart to said lubricating oil between about 1% and about 10% of additive by weight, said amount being sufficient to enhance substantially the viscosity index, detergent and anticorrosion characteristics of said oil.

11. A lubricating oil composition consisting essentially of a mineral lubricating oil having dissolved therein sufficient of the additive composition defined by claim 5 to impart to said lubricating oil between about 1% and about 10% of additive by weight, said amount being suflicient to enhance substantially the viscosity index, detergent and anticorrosion characteristics of said oil.

12. A lubricating oil composition consisting essentially of a mineral lubricating oil having dissolved therein sufiicient of the additive composition defined by claim 6 to impart to said lubricating oil between about 1% and about 10% of additive by weight, said amount being suflicient to enhance substantially the viscosity index, detergent and anticorrosion characteristics of said oil.

13. A lubricating oil composition consisting essentially of a mineral lubricating oil having dissolved therein sutlicient of the additive composition defined by claim 7 to impart to said lubricating oil between about 1% and about 10% of additive by weight, said amount being sutficient to enhance substantially the viscosity index, detergent and anticorrosion characteristics of said oil.

14. A lubricating oil composition consisting essentially of a mineral lubricating oil having dissolved therein suificient of the additive composition defined by claim 8 to impart to said lubricating oil between about 1% and about 10% of additive by Weight, said amount being sufficient to enhance substantially the viscosity index, de terent and anticorrosion characteristics of said oil.

15. A lubricating oil additive composition adapted for addition to mineral lubricating oil to produce a lubricating oil composition having high viscosity index, detergent and anticorrosion characteristics, said additive composition consisting essentially of a mineral lubricating oil containing between about 15% and about 50% by weight of a product obtained by reacting 1.0 part of a hydrocarbon polymer selected from the class consisting of the homopolymers of monoolefins containing from 3 to 6 carbon atoms, and copolymers of said monoolefins with between about 0.005 and about 0.1 part by weight of a conjugated diolefin containing from 4 to 7 carbon atoms, said polymer having an average molecular weight between 5,000 and 50,000, said hydrocarbon polymer being prepared at a temperature between 20 C. and C. using a Friedel-Crafts catalyst, with between about 0.01 and about 0.15. part of a compound selected from the class consisting of methyl trithiometaphosphate and ethyl trithiometaphosphate, at a temperature between about 20". C. and about C. for between about 2 and 9 about 10 hours to produce an acidic phosphorus and sulfur-containing reaction product, neutralizing the last named reaction product with a metal base of the class consisting of the alkali and alkaline earth metal bases and heating the neutralized product with 0.05 to 0.4 part of an alkyl substituted phenol containing 4 to 12 side chain carbon atoms to a temperature of 100 C. to 180 C., and adding thereto 0.1 to 2.5 equivalents of an alkaline earth metal base per equivalent of neutralized product.

16. A lubricating oil composition consisting essentially of a mineral lubricating oil having dissolved therein sufficient of the additive composition defined by claim 15 to impart to said lubricating oil between about 1% and about 10% of additive by weight, said amount being suflicient to enhance substantially the viscosity index, detergent and 'anticorrosion characteristics of said oil.

17. A lubricating oil additive composition adapted for addition to mineral lubricating oil to produce a lubricating oil composition having high viscosity index and detergent characteristics, said additive composition consisting essentially of a mineral lubricating oil containing between about 15% and about 50% by weight of a product prepared by reacting a metal base of the class consisting of the alkali and alkaline earth metal bases with an acidic phosphorusand sulfur-containing reaction product of 10 between about 0.01 and about 0.15 part of a compound selected from the class consisting of methyl trithi0metaphosphate and ethyl trithiometaphosphate and 1.0 part of a hydrocarbon polymer selected from the class consisting of the homopolymers of monooleiins containing from 3 to 6 carbon atoms and copolymers of said monoolefins and between about 0.005 and about 0.1 part by weight of a conjugated diolefin containing from 4 to 7 carbon atoms, said polymer having an average molecular weight, between about 5,000 and about 50,000, said hydrocarbon polymer being prepared at a temperature between '20 C. and C. using a Friedel-Crafts catalyst, the amount of said metal base being that amount necessary to neutralize said acidic reaction product.

References Cited in the file of this patent UNITED STATES PATENTS 2,316,080 Loane et al. Apr. 6, 1943 2,316,082 Loane et al. Apr. 6, 1943 2,561,773 Augustine July 24, 1951 2,767,164 Asseif et al. Oct. 16, 1956 2,768,954 Fields Oct. 30, 1956 2,768,999 Hill Oct. 30, 1956 2,838,484 Karll et al. June 10, 1958

Claims

1. A LUBRICATING OIL ADDITIVE COMPOSITION ADAPTED FOR ADDITION TO MINERAL LUBRICATING OIL TO PRODUCE A LUBRICATING OIL COMPOSITION HAVING HIGH VISCOSITY INDEX, DETERGENT AND ANTICORROSION CHARACTERISTICS, AND ADDITIVE COMPOSITION CONSISTING ESSENTIALLY OF A MINERAL LUBRICATING OIL CONTAINING BETWEEN ABOUT 15% AND ABOUT 50% BY WEIGHT OF A PRODUCT OBTAINED BY REACTING 1.0 PART OF A HYDROCARBON POLYMER SELECTED FROM THE CLASS CONSISTING OF THE HOMOPOLYMERS OF MONOOLEFINS CONTAINING FROM 3 TO 6 CARBON ATOMS, AND COPOLYMERS OF SAID MONOOLEFINS WITH BETWEEN ABOUT 0.005 AND ABOUT 0.1 PART BY WEIGHT OF A CONJUGATED DIOLEFIN CONTAINING FROM 4 TO 7 CARBON ATOMS, SAID POLYMER HAVING AN AVERAGE MOLECULAR WEIGHT BETWEEN 5,000 AND 50,000 SAID HYDROCARBON POLYMER BEING PREPARED AT A TEMPERATURE BETWEEN -20*C. AND -100* C. USING A FRIEDEL-CRAFTS CATALYST, WITH BETWEEN ABOUT 0.0U AND ABOUT 0.15 PART OF A COMPOUND SELECTED FROM THE CLASS CONSISTING OF METHYL TRITHIOMETAPHOSPHATE AND ETHYL TRITHIOMETAPHOSPHATE, AT A TEMPERATURE BETWEEN ABOUT 20*C. AND ABOUT 190*C. FOR BETWEEN ABOUT 2 AND ABOUT 10 HOURS TO PRODUCE AN ACID PHOSPHORUS AND SULFUR-CONTAINING REACTION PRODUCT AND NEUTRALIZING THE LAST NAME REACTION PRODUCT WITH A METAL BASE OF THE CLASS CONSISTING OF THE ALKALI AND ALKALINE EARTH METAL BASES.