US3405065A - Detergent lubricant compositions for closed emission internal combustion engines - Google Patents

Description

United States Patent Office 3,405,065 Patented Oct. 8, 1968 4 Claims. (Cl. 252-515) ABSTRACT OF THE DISCLOSURE Mineral lubricating oil composition contains the combination of nitrogenous ashless detergent and ethylene glycol monoalkyl ether.

This application is a continuation of Ser. No. 580,892, filed Sept. 21, 1966, and now abandoned, and a continuation-in-part of Ser. No. 468,517, filed June 30, 1965, and now abandoned.

This invention relates to novel lubricating oil compositions. More particularly, the invention is concerned with superior new ashless detergent lubricating oil compositions for use in spark ignition, internal combustion engines equipped with valve-controlled positive crankcase ventilation systems.

In recent years spark ignition, internal combusion engines have been equipped with a positive crankcase ventilation (PCV) system to reduce the fumes normally produced by the operation of such engines. This system commonly comprises a tube or other conduit connecting the crankcase to the air-fuel intake system such as the carburetor or intake manifold of the engine. Since the pressure conditions in both the carburetor and the crankcase may vary widely, it is the usual practice to connect the crankcase and intake system through a control valve, orifice or other pressure control means. This control prevents abnormally high vacuums which occur from time to time during normal engine operation from imposing a vacuum on the crankcase which might pull oil along with the fumes from the crankcase.

In the normal operation of PCV systems, particularly those including control valves, the systems become plugged with carbon deposits and sludges due to the condensatiOn of oil vapors and other materials found in crankcase fumes. This plug results in improper carburetor mixtures, causing poor idling and stalling. Also, crankcase ventilation is reduced, leading to increased engine sludge.

In the past, maintenance of PCV systems has required that the motorist either replace the valve periodically or remove it and clean it in a suitable solvent. In practice this was not often done due to the expense and inconvenience usually associated with any sort of engine overhaul, as well as lack of understanding for the need for periodic servicing.

In accordance with the present invention, a superior new ashless detergent lubricating oil composition has been discovered which comprises a major proportion of mineral lubricating oil, a minor proportion suflicient to improve the detergent characteristics thereof of a nitrogenous ashless detergent obtained by the acylation of alkylene polyamines having from 2 to 20 carbon atoms and from 2 to 10 nitrogen atoms with alkenylsuccinic acid or alkenylsuccinic anhydride having from about 30 to about 400 carbon atoms in the alkenyl group and from about 2 to about 10% by weight of ethyleneglycol monoalkyl ether having 1 to 3 ethyleneglycol units and from 1 to 8 carbon atoms in the alkyl group.

The ashless detergent lubricating oil compositions of the present invention derive greatly improved operation of spark ignition, internal combustion engines equipped with valve-controlled positive crankcase ventilation sys tems, particularly those wherein fumes are withdrawn from the crankcase intake system. Proper fuel-air ratios are maintained, thus resulting in easier starting, better warm-up without stalling and improved idling. There is also a remarkable improvement in prevention of carbonaceous or sludge-type deposits on oil screens, piston rings and other engine parts, as well as decreases in ring and cylinder wear.

The nitrogenous ashless detergents are prepared by heating the alkylene polyamine and alkenylsuccinic acid or alkenylsuccinic anhydride with the removal of water. The temperature of the reaction will generally be from about 200 to about 500 F., more particularly from about 225 F. to about 400 F. The mol ratio of the polyamine to the succinic acid or anhydride will generally be in the range of from about 0.5 :1 to about 1.5 :1, more particularly from about 0.821 to about 1.2: 1. The time for the re-. action will generally be from about 10 minutes to about 12 hours or more, usually in the range of about 20 minutes to about 6 hours. If desired, the reactants may be employed with an inert reaction medium, such as a hydrocarbon, for example, mineral lubricating oil. In such case, the concentration of the reactants may range from about 1 to 90% by weight, but will usually be from about 25 to by weight of the total reaction mixture. During the reaction, it may be desirable to remove water formed from the reaction, as for example by distillation. Subatmospheric pressures may be used for this purpose with advantage.

The amine with which the alkenylsuccinic acid or alkenylsuccinic anhydride reacted preferably has at least one primary amino group. The nitrogen atoms are joined by alkylene groups of from 2 to 6 carbon atoms, preferably of from 2 to 3 carbon atoms, except the primary amino groups will be substituted with hydrogen or lower alkyl groups of from 1 to 6 carbon atoms, more usually from 1 to 3 carbon atoms. Nitrogen atoms may be present as a heterocyclic ring.

The polyalkyl polyamine reactant is illustrated by the following general formula:

wherein A is an alkylene radical containing from about 2 to 6 carbon atoms, R is a member of the group consisting of hydrogen and alkyl radicals containing from about 1 to 6 carbon atoms, x is a number from 0 to 10, y is a number from 0 to 2, and z is a number from 0 to 1, the total of x+y+z being a number from 1 to 10.

Illustrative alkylene polyamines of the foregoing types are ethylenediamine, diethylenetriamine, triethylenetetramine, dipropylenetriamine, dimethylaminopropylamine, tetraethylenepentamine, N-aminoethyl piperazine, pentaethylenehexamine, nonaethylenedecamine, etc.

The alkenylsuccinic acid or alkenylsuccinic anhydride reactant is illustrated by the following structural formula for the anhydride:

0 RCH o CHPfi wherein R is a hydrocarbon radical having from 30 to 400 carbon atoms, preferably from about 50 to about 200 carbon atoms.

The R'radical of tli'ej'above formula, that is, the alkenyl radical, is readily obtained by polymerizing olefins of from 2 to 5 carbon atomsfsuch as propylene, ethylene, isobutylene, pentene, etc., and mixtures thereof. Methods of polymerization are well known in the art, e.g., US. Patents Nos. 3,024,237, 3,024,195 and 3,018,291.

The preferred acylated alkylene polyamines are the monoalkenyl succinimides of tetraethylenepentamine of the formula:

wherein R is a polyolefin radical of from 30 to 200 carbon atoms and is derived from an olefin of 2 to 5 carbon atoms.

The nitrogenous ashless detergents of the lubricating oil compositions of the invention are employed in amounts sufficient to improve the detergent characteristics. Ordinarily, amounts of from about 0.1 to about by weight are satisfactory for this purpose.

The ethyleneglycol monoalkyl ether is preferably the diethylene monobutyl ether. However, other glycol ethers or mixtures thereof within the aforementioned general class may be employed. Such glycol ethers include diethyleneglycol monoethyl ether (Carbitol), diethyleneglycol monomethyl ether (Methyl Carbitol), diethyleneglycol monobutyl ether (Butyl Carbitol), ethyleneglycol monoethyl ether (Cellosove), ethyleneglycol monomethyl ether (Methyl Cellosolve), and ethyleneglycol monobutyl ether (Butyl Cellosolve).

The .base oil in the lubricant composition of the invention is any oil of lubricating viscosity. Thus, the base oil can be a refined paraffin-type base oil, a refined naphthenic-type base oil, or a synthetic hydrocarbon or synthetic nonhydrocarbon oil of lubricating viscosity. As synthetic oils, suitable examples include oils obtained by polymerization of lower molecular weight alkylene oxides, such as propylene oxide and/or ethylene oxide employing alcohol or acid initiators, such as lauryl alcohol or acetic acid. Still other synthetic oils include esters, e.g., di-(2- ethylhexyD-sebacate, tricresylphosphate and silicate esters, such as tetra-(Z-ethylhexyl)-orthosilicate and hexa-(2- ethylbutoxy)-disi loxane. For present purposes the mineral lubricating oils are preferred, since they show the greatest improvement.

' Lubricant compositions within the scope of the present invention may also contain still other additives of conventional types, such as pour point depressants, oiliness and 4 extreme pressure agents, antioxidants, dyes, blooming agents and the like.

Illustrative lubricant compositions of the aforementioned types may include,, f or example, from about 0.1 to about 10% by weight of alkalineearth'metal, higher alkylphenatedetergent andwear reducing agents. such as the calcium alkylphenate having mixed alkyl groups of 12 to 15 carbon atoms. They may also-include from about 0.1 to 10% by weight of organic thiophosphate corrosion and high temperature oxidation inhibitors, such as'the reaction product of pinene andP s the reaction product of polybutene and P 55, andfthe bivalentmetal dihydrocarbon dithiophosphates, zinc butyl hexyl dithiophosphate and zinc di-(tetradecylphenyl) dithiophosphate. Metal salt detergents in amounts from about 0.1 to 10% which may also be used are the calcium petroleum sulfonates of the oil-soluble mahogany type and the calcium naphthenates.

The operation of. a spark ignition, internal combustion engine with positive crankcase ventilation (PCV) employing a crankcase lubricating oil containing glycol ether is illustrated in a series of tests. In the tests,"a 1964 Ford car with a 6-cylinder engine was employed. A variety of lubricating oil compositions were evaluated, including two used oils. The fuel was a conventionalpremium-grade leaded gasoline.

In the tests the crankcase ventilation system included a typical spring-loaded ball control valve known as the General Motors AC system. Oil A was a multigrade SAE 10W-30 lubricating oil consisting of a solvent-refined 130 neutral mineral lubricating oil base .along with about 8% by weight of dodecylmethacrylate vinyl pyrrolidone copolymer ashless detergent, 1% zinc butyl hexyldithiophosphate, and about 0.5% tetrapropenylsuccinic acid rust inhibitor. Oil B was a solvent-refined SAE 30 mineral lubricating oil containing copolymer of dodecylmethacrylate, polyethyleneglycol (1800 molecular weight) methacrylate and N-aminoethyl piperazine-glycidylmethacrylate copolymer as ashless detergent in combination with zinc butyl hexyl dithiophosphate oxidation-corrosion inhibitor. Oil C was a typical MIL-L-2104B SAE 30 lubricating oil containing polyisobutenyl succinimide of tetraethylenepentamine ashless detergent, calcium petroleum sulfonate, calcium tetradecylphenate, zinc di-(tetradecylphenyl) dithiophosphate and zinc butyl hexyl dithiophosphate. Oil D was similar to Oil A except that it contained in addition about 3% of the polyisobutenyl succinimide of tetraethylenepentamine, having about 65 carbon atoms inthe polyisobutenyl group. Oil E was a solvent-refined mineral lubricating oil base containing calcium petroleumsulfonate, calcium tetradecylphenate and zinc butyl hexyl dithiophosphate as detergent and oxidation-corrosion inhibitor. Oils F and G were used, conventional spark ignition, internal combustion engine lubricating oils of undetermined constitution.

TABLE I Flow rate at 14 in. Hg 011 Net Type service Ap, c.t.m. 1

miles Initial Final AMultigrade SAE 10W-30 10 1. 80 2. 63 10 1. 2. 60 B-Single Grade SAE 30 10 1.60 2. 60 10 0. 2. C-MIL-L-2104B SAE 30 10 1.70 2. 10 1.00 2. 60 DMS Quality SAE 10W-30 10 1. 2. 60 10 1. 20 2. 65 E-ML Single Grade SAE 30 10 1. 82 2. 65 l0 1. 55 2. 62

E-MS Single Grade SAE 30 10. 0.30 2. 50 D-MS Multlgrade SAE 10W-30 10 0.30 2. 60 F-Used Test Oil N0. 1 from Lab En 10 1. 72 e 2. 60 G-Uscd Test Oil No. 2 from Lab Eng 10 '.do... 1. 40 2. 60 A-Multigrade SAE 10W-30 7 Aunt Minnie (short ps 0t 1. 55 2. 60

0.5 to 2.0 mi. in-length). A-Hultlgradt) SAE 10W-30 7. 6 Chassis Dyna. at; 40 F. 1.80 60 after 12-hr. soak at 40 F. 0 1 hr. of idling"; 25 2. 30

Clean Flow Rate at 14 In. Hg Ap=2.60 c.f.n1.

The tests were carried out in general on the basis of miles city-type service. In addition, a test was made with the car operating on so-called Aunt Minnie service with short trips of /2 to 2 miles with intermittent cold soaking, during which the engine was allowed to cool to ambient temperatures. In still another test the performance was evaluated on a chassis dynamometer where the car had been cold soaked at 40 F. for 12 hours prior to adding the glycol ether. Also, the clean-up effect of one hour of idling of the engine was determined. In each case the glycol ether was diethyleneglycol monobutyl ether, and was employed in an amount of about 3% by weight based on the total crankcase lubricating oil composition.

Briefly summarized, the essential procedure of the tests involved measuring the initial flow rate of the PCV control valve and the final flow rate, each in cubic feet per minute at 14 inches of mercury differential pressure, the latter being approximately the pressure differential (vacuum) obtained in normal engine operation with the valve closed. The test results are shown in the preceding Table I.

The above test results show that the PCV systems of spark ignition, internal combustion engines are markedly improved 'by the operation of the engine with crankcase lubricating oil compositions containing diethyleneglycol monobutyl ether. A satisfactory clean-up which returns the PCV system to practically new performance is obtained within 10 miles of operation under normal types of service. Thus, it was not necessary for the system to be removed for cleaning or replacement.

In addition to the foregoing tests, the effect of ethyleneglycol monoalkyl ether in combination with nitrogenous ashless detergent as the sole detergent in lubricating oil compositions was determined. The lubricating oil composition is mixed with pyruvic acid at a concentration of 100 grams of acid per kilogram of oil. The mixture is heated at 284 F. for /2 hour. After standing about hours, the weight of sedimented insoluble resin formed is measured. Low values indicate good detergency, and the procedure is found to correlate with actual spark ignition internal combustion engine operation.

Using the aforementioned procedure, the addition of a typical nitrogenous ashless detergent additive package to a solvent-refined SAE 30 mineral base oil was found to give 13.4 grams per kilogram of insoluble resin, whereas the addition of nitrogenous ashless detergent in combination with ethyleneglycol monoalkyl ether actually lowered the insoluble resin formation to 8.8 grams per kilogram. This is surprising, since the presence of polyglycol ethers usually detracts from the effectiveness of detergents in lubricating oil compositions. The polyglycol ether in similarly compounded mineral oil omitting the detergent gave 67.7 grams per kilogram resin.

The nitrogenous ashless detergent additive mentioned above was polyisobutenyl succinimide of tetraethylenepentamine having about 65 carbon atoms in the polyisobutenyl group. The compound lubricating oil composition contained 1.2% by weight alkenyl succinimide, 6 mm./ kg. zinc butyl hexyl dithiophosphate oxidation-corrosion inhibitor and 1 mm./kg. zinc di-(tetradecylphenyl) dithiophosphate oxidation-corrosion inhibitor. The similarly compounded mineral oil omitting detergent was solvent refined mineral base oil containing 12 mm./ kg. zinc butyl hexyl dithiophosphate. The ethyleneglycol monoalkyl ether was the diethylene monobutyl ether and was used in an amount to provide a concentration of 3.2% by weight in the lubricating oil composition.

As illustrated above, another embodiment of the present invention lies in the combination of nitrogenous ashless detergent and ethyleneglycol monoalkyl ether as a new additive combination for lubricating oil compositions for spark ignition, internal combustion engines. In this new combination the weight ratio of nitrogenous ashless detergent to ethyleneglycolmonoalkyl ether is generally from about 0.01:1 up to about 15:1 and preferably from about 0.3:1 up to about 5:1 for most effective engine cleanliness and PCV system operation.

While the character of this invention has been described in detail with numerous examples, this has been done by way of illustration only and without limitation of the invention. It will be apparent to those skilled in the art that numerous modifications and variations of the illustrative examples may be made in the practice of the invention within the scope of the following claims.

I claim:

1. Lubricating oil composition which comprises a major proportion of mineral lubricating oil, a minor proportion sufficient to improve the detergent characteristics thereof of a nitrogenous ashless detergent obtained by the acylation of alkylene polyamines having from 2 to 20 carbon atoms and from 2 to 10 nitrogen atoms with alkenylsuccinic acid or al kenylsuccinic anhydride having from about 30 to about 400 carbon atoms in the alkenyl group and from about 2 to about 10% by weight of ethyleneglycol monoalkyl ether having 1 to 3 ethyleneglycol units and from 1 to 8 carbon atoms in the alkyl group.

2. A lubricating oil composition in accordance with claim 1 in which the ethyleneglycol monoalkyl ether is diethyleneglycol monobutyl ether.

3. A- lubricating oil composition in accordance with claim 1 wherein the nitrogenous ashless detergent is the monoalkenyl succinimide of tetraethylenepentamine of the formula:

wherein R is a polyolefin radical of from 30 to 200 carbon atoms and is derived from an olefin of 2 to 5 carbon atoms.

4. A lubricating oil composition in accordance with claim 3 wherein the ethyleneglycol monoalkyl ether is diethyleneglycol monobutyl ether.

No references cited.

PATRICK P. GARVIN, Primary Examiner.