US3448047A - Lube oil dispersants - Google Patents

Description

United States Patent U.S. Cl. 252-515 8 Claims ABSTRACT OF THE DISCLOSURE Modified Mannich type condensation products from a polymer substituted phenol, an alkylene polyamine and formaldehyde wherein a portion of the alkylene polyamine is replaced with an alkyl-substituted pyridine. These products are useful as lubricating oil dispersants.

Background of the invention This invention relates to modified Mannich condensation products as novel compounds and more particularly relates to novel condensation products C and higher alkyl-substituted phenols, formaldehyde, alkylene polyamine, and an alkyl-substituted pyridine; their preparation and their use as detergent-dispersant addition agents for lubricant oil formulations.

The prior art portrays a need for improved engine lubricating oil additives which function as dispersants to retain in suspension insoluble particles such as the prodducts of fuel combustion, those of incipient oxidation, and those of lubricant deterioration. The control of the deterioration of lubricating oils has long been a problem, particularly in the formulation of the compositions of lubricating oil additives.

It has been known for many years that deterioration of hydrocarbon lubricating oils causes the formation of substances which deleteriously affect the surfaces which the lubricants are developed to protect through the maintenance of reduced frictional forces between said surfaces. Lubricating oil deterioration not only causes the formation of surface-deleterious substances, but it also results in the agglomeration of sludge-like materials in the lubricants and the deposition of varnish on the surfaces.

For many years it has been a practice to include as additives in lubricating oils, chemical compositions which tend to reduce oil deterioration and the consequent formation of the sludgeand varnish-like material. Broadly included in the classification of additives are corrosion and oxidation inhibitors, and dispersing agents. These additives generally function to reduce the corrosion of the surfaces to be protected, to stabilize the lubricating oil, to inhibit deterioration by oxidation, and to function as dispersants which tend to prevent the agglomeration of sludge and the deposition of varnish and sludge caused by the formation of the products of deterioration.

Frequently, the inclusion into lubricating oils of corrosion, oxidation, and dispersant agents is highly desirable; however, the problems of compatibility of these three or more functional agents creates serious difficulties in the formulation of useful additive-containing lubricating oils. Much research and development effort has been expended in the search for improved lubricating oil additives which function in the above-enumerated manner. The research efforts have been directed toward the development of three or more separate agents, as well as a single agent, or a plurality of compatible agents that will perform all of the desired functions when incorporated into hydrocarbon lubricating oils.

Various Mannich condensation products are known in the prior art as lubricating oil additives; however, the

teachings of the disclosures indicate that these Mannich products have previously been considered for use as oxidation inhibitors and as anti-wear additives. The former tend to reduce the rate of formation of oxidation products and the latter tend to coat surfaces with films and reduce friction resulting in less wear; consequently, there is some reduction of particulate and product contamination of the lubricating oil medium. It is also well-known that various Mannich products produced for use as oxidation inhibitors and anti-wear additives demonstrate limited solubility in lubricating oil, which factor is also an undesirable characteristic of an additive. In view of the above, it has long been attempted to develop Mannich products and derivatives thereof which have novel functional properties as well as improved solubility in lubricating oils when incorporated therein.

Accordingly, it is an object of this invention to provide new compositions of matter.

It is an additional object of this invention to provide new compositions of matter which are useful as dispersants in lubricating oil compositions.

Another object of this invention is to provide lubricating oil dispersants which have improved solubility in said oil and which exhibit superior compatibility with other oil including additives.

An additional object of this invention is to provide a novel process for the preparation of compositions useful as dispersants.

Another object of this invention is to provide improved lubricating compositions.

Other objects and advantages of the invention disclosed and claimed herein will become apparent from the specification, including various embodiments, examples, and the claims.

Summary of the invention It has been discovered that improved dispersant-detergent compositions for lubrication oils can be made by condensing a phenol substituted with a high molecular weight hydrocarbon with an aldehyde, an alkylene polyamine, and an alkyl-substituted pyridine. Suitably, in carrying out the condensation, the reactants are used in the following ratios: 1 mole of high molecular weight substituted phenol, 1.53.0 moles of aldehyde, 0.5-1.5 moles of alkylene polyamine, and 0.5-1.5 moles of alkyl-substituted pyridine.

The high molecular weight hydrocarbon-substituted phenols suitable for use in this invention are those that have a number average molecular weight in the range from 800 to 2,500. The high molecular weight alkyl-substituted phenols are obtained by the alkylation in the presence of B1 or aluminum chloride or generally in the presence of a Friedel-Crafts type catalyst of phenol with C and higher carbon content polypropylenes or polybutenes. Copolymers of polypropylene with monomers copolymerizable therewith may be employed wherein the copolymer molecule contains at least polypropylene units. C0- polymers of butenes (butene 1, butene 2 and isobutylene) with monomers copolymerizable therewith may also be employed wherein the copolymer molecule contains at least 90% butene units.

More specifically, suitable high molecular weight alkylphenols are described in a copending application, S.N. 484,758, filed Sept. 2, 1965.

The aldehyde suitable for use in this invention is formaldehyde. Formaldehyde per se need not be used as a reactant in the process of this invention. Suitable formaldehyde yielding sources may be used such as, aqueous and alcohol solutions of formaldehyde, paraformaldehyde, and trioxymethylene. These, as Well as formaldehyde itself, may be used to provide the quantities of formaldehyde required for the purposes of this invention.

Suitable alkylene polyamine reactants include ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine, hexaethylene heptamine, heptaethylene octamine, octaethylene nonamine, nonaethylene decamine and decaethylene undecamine and mixtures of such amines having nitrogen contents corresponding to the alkylene polyamines according to the formula,

where A is divalent ethylene and n is 1-10. Corresponding propylenepolyamines such as propylene diamine and di-, tritetra-, penta-propylene, tri-, tetraand penta-amines are also suitable reactants. The alkylene polyamines are usually obtained by the reaction of ammonia and dihalo alkanes, such as dichloro alkanes.

The alkyl-substituted pyridines suitable for use in this invention are pyridines wherein the alkyl group ranges in size from C to about C The preferred substituted pyridines are the methylpyridines and more specifically, alphamethylpyridine or alpha-picoline.

PREPARATION The following procedure was used in preparing the novel additive described and claimed herein.

One mole (850 grams) of a C alkylated phenol obtained in a BF catalyzed alkylation of phenol with a C polypropylene, 1 mole (93 grams) of picoline, and 1 mole (189 grams) of a tetraethylene pentamine were combined in atlask. This mixture was heated to about 35-40 C. to reduce the viscosity and to allow the components to be stirred. Two moles (162 grams) of a 37% formaldehyde solution was added slowly over a period of one hour. After stirring under a nitrogen blanket for about one additional hour the reaction products were heated. The exothermic heat generated raised the temperature to about 60 C. during the addition of the formaldehyde; however, at the end of the stirring the temperature had been reduced to about 47 C. The temperature was raised slowly over a period of about five hours to about 100 C. and the mixture was allowed to stand under a nitrogen blanket for about 12 hours. Subsequently, water was stripped from the system by heating to about 150 C. during a period of about six hours, and after nitrogen blowing at about 150 C. for about one additional hour the reaction product was cooled and removed from the flask. The product yield was about 90%.

The reaction product of the above described preparation was found to have a pH of about 10, a total base number of about 149 milligrams KOH per gram of product, a nitrogen content of about 5.84%, and an average molecular weight of about 1371. The material was dissolved in lubricating oil at concentrations shown and was then used in the following tests.

LABORATORY OXIDATION TEST A 300 gram sample of lubricating oil containing the additives of this invention was heated to about 166 C. with stirring. A glass rod was inserted in the oil to measure the varnish formed thereon. A copper ribbon having an area of about five square inches and a ribbon of iron having an area of about ten square inches were immersed in the lubricant oil additives containing sample to function as catalysts. Intermediate inspections were made and at the end of 72 hours varnish formation on the glass rod was estimated visually and reported on a scale of 1-10, where was perfectly clean. The acidity developed in the oil, the pentane insolubles, and the viscosity increase of the oil were also determined. Table I shows the results of the testing of the novel additives of this invention in accordance with the foregoing.

TABLE I.LABORATORY OXIDATION TEST RESULTS Acidity mg. Pentane insolnbles Additive Varnish KOH per g. (percent) concentration,

percent 48 72 24 48 72 24 48 72 A used oil analysis was conducted to develop comparative data for various concentrations of the novel additives of this invention and the results are portrayed below in Table II.

TABLE II.USED OIL ANALYSIS Used Additive Conc. New, 2% 2% 5% Vrs. 05 336. 9 343 401. 3 V18. 100 SSU 1516.9 1587 1860.8 Vis. 210 SSU 101. 7 101. 5 110. 2

It is apparent from the above data that the lubricant containing the novel additive of this invention has excellent stability and provides a high degree of cleanhness.

LINCOLN ENGINE TESTS Phase 1 Phase 2 Phase 3 Duration (min.) 45 1 2 75 Speed, r.p.m 500 2500 2500 Lead, brake horsepower No load 105 Temperature, F.:

Water jacket -120 130 -175 Oil sum 120-125 -180 205-210 Air/fuel ratio 9. 5:|=0. 5 15. 5i0. 5 15. 5:0. 5

1 Hour.

The 4-hour cycle is repeated a total of 48 times (192 hours running time). After each 16 hours of operation the engine is shut down for eight hours. The oil level is adjusted with fresh oil to a level of five quarts. At the termination of the test, the hot oil is drained. The engine is then disassembled and examined for deposits of varnish and sludge among other observable results.

In the Lincoln M.S. Test Sequence V, after the formulated lubricant oil has been tested and the engine disassembled for inspection of the parts thereof for sludge and varnish deposits among other inspections, the total varnish and sludge ratings are made from the individual ratings of the following engine parts.

Varnish: Sludge:

Piston Push Rod Chamber Rocker Arm Cover Rocker Arm Assembly Push Rod Cover Cylinder Walls Oil Pan Rocker Arm Cover Oil Screen Oil Pan Push Rod Cover Timing Gear Cover Valve Deck Lincoln Engine Tests No. 1, No. 2, and No. 3

A triple Lincoln engine test was run on a lubricating oil containing 2.4% by weight of the novel additive of this invention along with 3% by weight of a high temperature detergent, 3% by weight of a high base sulfonate, and 1% by weight of a. zinc dialkyl dithiophosphate oxidation inhibitor. All of the ingredients except the additive of this invention are readily available in the commercial marketplace. The results of the tests are shown below in Table IH.

TABLE IH.-LINCOLN ENGINE TEST RESULTS 8 p uggmg 1 con- Test N o. Sludge rating rating (percent) sumption 46 46 Low. 40 40 0 0. 43 39 Average.

Lincoln Engine Test No. 4

TABLE IV .-Lincoln engine test results Test No. 4 Sludge rating 43 Average rating 39 Oil ring plugging (percent) 0 Oil screen plugging 5 FORD 289 ENGINE TESTS Two tests designated Test No. 5 and Test No. 6 were conducted on lubricating oils of different formulations in the Ford 289 cubic inch displacement engine in a manner similar to the above described Lincoln tests, each of these tests are well-known to those of ordinary skill in the art. I

289 Engine Test No. 5

This test was conducted on a lubricating oil formulation containing 3% by weight of a high-temperature detergent, 3% by weight of a sulfonate anti-rust agent, 1% of a zinc dialkyl dithiophosphate oxidation inhibitor, and 0.25 of an anti-wear agent, all readily available commercially. This formulation also contained 2.4 of the novel additive of this invention. The results obtained in this test are as follows in Table V:

TABLE V.--Ford 289 engine test results Test No. 5 Sludge rating 47 Average rating 45 Oil ring plugging, percent 0 Oil screen plugging 0 289 Engine Test No. 6

This lubricating oil formulation contained about 9.22% by weight of a polymethacrylate viscosity index improver, about 3.37% by weight of a high-temperature detergent,

about 3.66% by weight of a sulfonate anti-rust agent,

about 1.27% by weight of a zinc dialkyl dithiophosphate oxidation inhibitor, and about 0.315% by weight of an anti-wear agent, all readily available commercially. The formulation also included about 2.4% by weight of the novel additive of this invention. The results of the test were as follows in Table VI:

TABLE VI.Ford 289 engine test results Test No. 6

The dispersants prepared as disclosed herein can be used as addition agents in lubricating oils and especially in .lu-bn'cating oils for use in internal combustion engines. The addition agents impart excellent low-temperature dispersancy characteristics to the lubricating oil. Although amounts of the dispersancy addition agent may be varied as desired, it is believed advantageous to use at least about 1 weight percent and up to 10 weight percent of the addition agent of this invention and preferably 2-5 weight percent in a suitable lubricating oil.

Although the preferred lubricating oils are the mineral lubricating oils, the use of the additive compositions is not restricted thereto. Other lubricating oil bases can be used, such as hydrocarbon oils, both natural and synthetic, for example, those obtained 'by the polymerization of olefins, as well as synthetic lubricating oils of the alkylene oxide type and the monoand polycarboxylic acid ester type, such as the esters of adipic acid, sebacic acid, azelaic acid; it is also contemplated that various other well-known additives, such as anti-oxidants, antifoam agents, pour point depressors, extreme pressure agents, corrosion inhibitors, anti-wear agents, etc., may be incorporated in lubricating oils containing the additives of our invention.

Concentrates of a suitable oil base containing more than 10 percent, for example, up to 75 percent or more, of the additive of this invention alone or in combination with other additives may be prepared and can be used for blending with hydrocarbon oils or other oils in the proportions desired for the particular conditions of use to give a finished lubricating product containing the additives of this invention. In order to exemplify the use of the reaction products prepared in accordance herewith as low dispersancy lubricating oil addition agents, examples of formulated lubricating oils containing such reaction products were prepared.

While in the foregoing specification this invention had been described in relation to preferred embodiments thereof, and many details have been set forth for the purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to other embodiments and that many of the details set forth herein can be varied considerably without departing from the basic principles of the invention.

Having described the invention, what is claimed is:

1. The condensation product of (a) formaldehyde, (b) an alkyl substituted phenol wherein the alkyl substituent contains at least 50 carbon atoms, (c) an alkyl sub stituted pyridine wherein the alkyl substituent contains from 1 to 8 carbon atoms, and (d) an alkylene polyamine having the formula:

wherein A is a divalent ethylene or propylene group and n is 1-10, said reactants being used in the ratios of 1.5-3.0 moles of formaldehyde, 1 mole of alkyl substituted phenol, 0.5-1.5 moles of alkyl substituted pyridine, and 0.5-1.5 moles of alkylene polyamine.

2. The product defined in claim 1 wherein the alkyl substituted phenol has a number average molecular weight of from 800 to 2,500.

3. The product defined in claim 2 wherein the alkyl substituent for the phenol is derived from either polypropylene or polybutene.

4. The product defined in claim 3 wherein the alkyl substituted pyridine is either alpha picoline or alpha methyl pyridine.

5. A composition com rising a major portion of a lubricating oil and from about 1-10 weight percent of the condensation product of (a) formaldehyde, (b) an alkyl substituted phenol wherein the alkyl substituentcontains at least 50 carbon atoms, (c) an alkyl substituted pyridine wherein the alkyl substituent contains from 1 to 8 carbon atoms, and (d) an alkylene polyamine having the formula:

HN(ANH),,H

wherein A is a divalent ethylene or propylene group and n is l-10, said reactants being used in the ratios of 1.5-3.0 moles of formaldehyde, 1 mole of alkyl substituted phenol, 0.5-1.5 moles of alkyl substtiuted pyridine, and 0.5-1.5 moles of alkylene polyamine.

6. The composition defined in claim 5 wherein the alkyl substituted phenol has a number average molecular weight of from 800 to 2,500.

7. The composition defined in claim 6 wherein the alkyl substituent for the phenol is derived from either polypropylene or polybutene.

8. The composition defined in claim 7 wherein the alkyl substituted pyridine is either alpha picoline or alpha methyl pyridine.

References Cited UNITED STATES PATENTS 3,340,192 9/1967 Henley 252--5l.5 3,360,464 12/1967 Otto 252'51.5

US. Cl. X.R. 260-4045