Dispersants prepared from polyamines and alkaryl carboxylic acids

[57] ABSTRACT

An oil-soluble additive useful for improving the properties of a fuel oil, a lubricating oil, a heating oil, a gasoline or the like is prepared by heating an aliphatic polyamine or amino alcohol with an alkylated aryl carboxylic acid at a temperature that causes the splitting out of water. The carboxylic acid is prepared by thermal diene addition of an alkylated aromatic hydrocarbon such as paraffin-wax-alkylated naphthalene, or of a ring-substituted hydroxy, amino, or vinyl derivative of such hydrocarbon, with an unsaturated monobasic acid, or with an unsaturated polybasic acid or its anhydride, such as maleic acid, maleic anhydride, acrylic acid, methacrylic acid, or the like. The additive can be modified by treatment with phosphorous acid.

Claims, No Drawings

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DISPERSANTS PREPARED FROM POLY AMINES AND ALKARYL CARBOXYLIC ACIDS

This application is a continuation-in-part of Serial No. 706,683, filed Feb. 19, 1968, now U.S. Pat. No. 3,526,661 which in turn is a continuation-in-part of Ser. No. 354,756, filed Mar. 25, 1964, and now abandoned.

DESCRIPTION OF THE INVENTION

This invention concerns an improved oil-soluble nitrogencontaining additive that serves multiple functions in oil compositions of the class of fuel oils, gasolines, heating oils, and lubricating oils. This additive can be characterized as an amide, imide, or ester derivative of an aliphatic polyamine or amino alcohol and an aromatic carboxylic acid wherein the said carboxylic acid is the diene adduct of a short chain unsaturated monocarboxylic acid, polycarboxylic acid, or acid anhydride and a long-chain-alkylated aromatic hydrocarbon or a hydroxy, amino, or vinyl derivative thereof. The invention is also directed to preparation of such additive and to oil compositions containing it.

For satisfactory lubrication of modern high compression piston type internal combustion engines, it is necessary to lubricate those engines with a crankcase oil that will provide a high degree of engine cleanliness and thus promote longer engine life. This requires a heavy duty detergent type of lubricating oil containing additives that will impart good detergency, efficient sludge dispersing action and high oxidation resistance. It is heretofore been the practice to supply detergency and dispersancy to heavy duty internal combustion engine lubricants by the use of metallic compounds such as metal salts or organic sulfonic acids, metal salts of alkylated phenols, metal salts of alkyl phenol thioethers, metal alcoholates, colloidal dispersions of carbonates and the like. Usually alkaline earth metal salts are employed for this purpose. More recently it has been recognized that metal-free additives, or at least additives that are relatively low in metal content, are preferred to the conventional metal-containing additives because the latter materials leave an ash residue which tends to accumulate in the combustion chamber of the engine and there cause pre-ignition, spark plug fouling, valve burning and similar undesirable conditions. For this reason an effective dispersant that is ash-free is preferred rather than an ash-forming detergent additive such as an alkaline earth metal salt of the types mentioned above. Ash-free dispersants are also of advantage in fuel oil compositions and diesel fuels.

In application Ser. No. 706,683, filed Feb. 19, 1968, of which the present application is a continuation-in-part, it is disclosed that an alkylated aromatic hydrocarbon or its monohydroxy derivative can be condensed with a dibasic acid, a dibasic acid anhydride or a dibasic acid halide in the presence of a Friedel-Crafts catalyst to form a keto acid which can then be condensed with a polyalkylene polyamine under conditions forming an amide, the product thereby obtained being mineral-oil-soluble and having dispersancy and detergency properties in liquid hydrocarbon compositions. The finding of the present invention is that an alkylated aromatic hydrocarbon of the type described in the parent application will condense with a short-chain, alpha,beta-unsaturated monobasic acid or with a short-chain unsaturated polybasic acid or its anhydride under thermal conditions in the absence of a Friedel-Crafts catalyst to form an aromatic carboxylic acid or anhydride which can then be reacted with an aliphatic polyamine under conditions causing the splitting out of water whereby an amide, an imide or an amidine is formed between one or more of the amino groups of the poly amine and the carboxyl groups of the aromatic carboxylic acid. The product is mineral-oil-soluble and is an effective dispersant and/or detergent inhibitor.

It is a further finding of the present invention that useful dispersants and/or detergent inhibitors can similarly be prepared by condensing the aromatic carboxylic acids of the type described with aliphatic amino alcohols under conditions causing the splitting out of water whereby there is reaction between the carboxyl groups of the acids and the hydroxyl groups of the amino alcohols to form esters or between the carboxyl groups of the acid and the amino groups of the amino alcohols to form amides or imides. These products can be further modified by reaction with phosphorous acid.

An alkylated aromatic hydrocarbon for use in this invention can be prepared by starting with an aromatic hydrocarbon having from six to 16 carbon atoms, such as benzene, toluene, xylene, or other C, to C_e alkyl benzene, or naphthalene, anthracene, phenanthrene, etc., and alkylating that aromatic hydrocarbon, or mixture of such hydrocarbons, with an olefin of from eight to 32 carbon atoms or with a C₈ to C₃₂halogenated paraffin hydrocarbon or mixture of halogenated hydrocarbons, such as chlorinated octane, chlorinated dodecane, brominated cetane, chlorinated kerosene, brominated gas oil, monobromo cetane, 1,2-dichlorodecane, etc. Chlorinated paraffin wax is particularly useful as an alkylating agent. Paraffin wax is a petroleum product that is a mixture of aliphatic hydrocarbons mostly in the C_I8 to C₃₂range. The hydrocarbon distribution will depend on the particular melting point grade of wax used. Thus a 125°-12 7° F. melting point wax will predominate in about C₂₃ to C₂₈aliphatic hydrocarbons.

Alkylation of the C_e to C₁₆ aromatic hydrocarbon can be effected not only by condensation with a halogenated aliphatic hydrocarbon as stated above, but also by Friedel-Crafts condensation with an olefin, such as diisobutylene, tetraisobutylene, or other isobutylene polymer, a propylene polymer such as tetrapropylene, a mixture of long chain olefins obtained by cracking a paraffin wax fraction, an alpha olefin obtained by ethylene polymerization, etc.

The alkylation with a halogenated aliphatic hydrocarbon or with an olefin can be conducted by any means known to the art, and usually is aided with a Friedel-Crafts catalyst, normally either A1C1₃ or BF₃. Other such catalysts include HF, polyphosphoric acid, etc. In most cases the alkylation product will be a mixture of hydrocarbons.

Another useful source of alkylated aromatic hydrocarbons which can be employed in preparing aromatic carboxylic acids for the present invention are the asphalt extracts known as petrolenes, which are obtained by removing the asphaltenes from a petroleum asphalt or crude oil residuum. See for example, U.S. Pat. Nos. 3,087,887 and 3,453,226. Petrolenes contain a high proportion of alkylated polycyclic aromatic hydrocarbons.

In addition to alkylated aromatic hydrocarbons of the types described above, it is also within the purview of the present invention to employ the ring-substituted hydroxy, amino and vinyl derivatives of such hydrocarbons, e.g., dodecyl phenol, paraffin-wax-alkylated tertiary butyl phenol, cetylated beta naphthol, styrene alkylated with chlorinated kerosene, paraffin-wax-alkylated aniline, beta-naphthylamine alkylated with tetraisobutylene, and paraffin-wax-alkylated vinyl naphthalene. The alkylated aromatic compounds entering into the diene condensation will have average molecular weights within the general range of about 500 to 4,000, or more usually from about 600 to 3,500.

The preparation of an alkylated naphthalene by the FriedelCrafts condensation of a halogenated aliphatic hydrocarbon with naphthalene is well known and is disclosed, for example, in U. S. Pats. Nos. 1,815,022 and 2,015,748. Briefly, the reaction involves the halogenation, (preferably chlorination) of an aliphatic hydrocarbon of from about 12 to about 32 carbon atoms until the product contains about 10 to 15 wt. percent of chlorine. The halogenated material is then condensed with naphthalene in the presence of aluminum chloride or similar Friedel-Crafts catalyst. For example, paraffin wax or petrolatum can be chlorinated at a temperature in the range of 140° to 300° F. until it contains 10 to 14 percent chlorine and it can then be condensed with naphthalene at 140° to 160° F. with the aid of a Friedel-Crafts catalyst.

A specific description of the alkylation of naphthalene with paraffin wax is as follows:

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A solution is prepared by adding bold 29.6 grams of naphthalene to 100 milliliters of orthodichlorobenzene at 65° F. To this is added 6 grams of aluminum chloride. Then, over a period of one hour, while the temperature is gradually raised to 140° F., 200 grams of chlorinated paraffix wax is added. The chlorinated wax is obtained by chlorinating crude paraffin scale wax of 125°-127°F. melting point to a content of 14.5 wt. percent chlorine. Following the addition of all of the chlorinated wax, the mixture is heated for 3 hours at 140° F. Thereafter, the mixture is diluted with 200 grams of mineral lubricating oil having a viscosity of 150 SUS at 100° F., thus furnishing a 50 wt. percent concentrate of the wax-alkylated naphthalene in oil.

To remove aluminum chloride from the product, 400 grams of the concentrate can be mixed with 100 grams of normal hexane and then the diluted mixture can be subjected to three or more successive washes using 200 milliliters of 2.5 normal HCI in each wash followed by three or more successive washes with hot water to remove residual acid. The orthodichlorobenzene can be removed from the product by heating it to 400° F. under reduced pressure (25 inches of mercury).

A wax-alkylated phenol can be prepared in the following manner: 80 grams of the same chlorinated paraffin wax, mentioned above, is mixed with 20.8 grams of phenol and 8 grams of aluminum chloride. The mixture is heated to about 120° F. for 1 hour after which the temperature is increased to 155° F. Then an additional 227 grams of the same chlorinated paraffin wax is added over a period of 30 minutes. Following this, the temperature is increased to about 285°-290° F. and held there for about 7 hours. Then the aluminum chloride is removed from the mixture with hydrochloric acid and water washing in the same manner as described above.

The alkylated aromatic hydrocarbon or its ring-substituted derivative is, in accordance with the present invention, subjected to diene condensation with an unsaturated aliphatic or aryl aliphatic monocarboxylic or polycarboxylic acid or acid anhydride having a total of from three to 10 carbon atoms and characterized by having the group:

—C=C—C=O

Such acids include acrylic, methacrylic, crotonic, isocrotonic, tiglic, angelic, sorbic, cinnamic, maleic, fumaric, itaconic, citraconic, teraconic, aconitic, allylmalonic, etc., and anhydrides of such acids.

Diene condensation between a diene compound, in this case the aromatic compound, and a dienophile, in this case the unsaturated carboxylic acid or its lower alcohol ester, has been investigated at great length by many workers, and numerous reports of the types of adducts that can be prepared by such condensation reaction appear throughout the chemical literature. See for example, the work of Bachman et al, J. Am. Chem. Soc., Vol 60, (1938) page 481 et seq., and of Andrews et al, J. Am. Chem. Soc., Vol. 75, (1953) page 3,776 et seq. The addition compounds that are formed by thermal diene condensation differ chemically from the keto acids that are formed when a dibasic acid or its anhydride is reacted with an alkylated aromatic compound in the presence of a FriedelCrafts catalyst, as disclosed in application Ser. No. 706,683.

To bring about the desired diene condensation the acid or anhydride and the alkylated aromatic compound are heated together at from about 200° to about 500° F., or more usually at from about 250° to 450° F. The reaction time is usually from about 5 to 15 hours, and will vary somewhat with the temperature and with the particular reactants. The progress of the reaction, and therefore its completion, can be determined by taking a periodic sample of the reaction mixture, separating unreacted acid from the sample and then subjecting the sample to infra-red analysis and noting when a peak in the carbonyl content occurs. In the case of maleic anhydride, which is a solid at room temperature and is insoluble in the usual solvents that may have been used, separation from the sample is relatively easy. If the acid is a low molecular weight liquid it may be stripped from the sample before testing.

At least one mole of acid or anhydride should be used per mole of alkylated aromatic material (hydrocarbon or ring-substituted derivative as described). An excess of acid or anhydride, up to about 2 moles per mole of aromatic reactant, is ordinarily desirable to favor the reaction. While even greater proportions will often favor the reaction even more, the obtaining of greater yields must be weighed against the increased expense of handling greater quantities of reactants.

Although a solvent is not necessary, ease of handling is sometimes facilitated by using a solvent such as cyclohexane, normal heptane, ortho dichlorobenzene, or a middle distillate fuel oil, residual fuel oil, or a mineral lubricating oil. If the solvent is low boiling, loss can be prevented by use of pressure. With higher boiling solvents, reflux can be used. If fuel oil or lubricating oil is used, the product can be obtained as a concentrate in the oil. Upon completion of the reaction, excess acid can be removed by blowing an inert gas such as nitrogen through the product.

In place of the acid or anhydride a C₂ to C₃ aliphatic alcohol ester can be used, e.g., diethyl maleate or ethyl acrylate; in which case the corresponding aromatic acid ester will be obtained, which can then react with the amino alcohol or alkylene polyamine, splitting out C, to C₃ alcohol instead of water.

The aliphatic polyamine that is employed in preparing the reaction products of the present invention can be an alkylene polyamine fitting the following general formula:

NH₂(CH₂)„- ^NH(CH₂)„J — nh₂ wherein n is 2 to 3 and m is a number from 0 to 10. Specific compounds coming within the formula include diethylene triamine, tetraethylene pentamine, dipropylene triamine, octaethylene nonamine, and tetrapropylene pentamine. N,N-di(2-aminoethyl)ethylene diamine can also be used. Other aliphatic polyamine compounds that can be used are the Naminoalkyl piperazines of the formula:

CHj- CH₂\r- R

CHs—CHs wherein n is a number 1 to 3, and R is hydrogen or an aminoalkyl radical containing one to three carbon atoms. Specific examples include N-(2-aminoethyl) piperazine, N-(2aminoisopropyl) piperazine, and N,N'-di-(2-aminoethyl) piperazine

The use of mixture of alkylene polyamines, mixtures of Naminoalkyl piperazines, and mixtures of the alkylene polyamines with the N-aminoalkyl piperazines is also contemplated.

The aliphatic amino alcohols that are employed in this invention have from two to 24 carbon atoms and can contain one or more primary, secondary, or tertiary amino groups. Particularly useful are the hydroxy alkyl alkylene diamines obtained by reaction of ethylene oxide, propylene oxide or butylene oxide, or mixtures thereof with ethylene diamine, propylene diamine, or butylene diamine. These reaction products can be characterized as Ν,Ν,Ν’Ν'-tetrakis (2hydroxyalkyl) alkylene diamine. Representative amino alcohols include: monoethanolamine, diethanolamine, triethanolamine, 2-methylaminoethanol, 2-diisopropyl amino ethanol, l-amino-2-propanol, triisopropanolamine, N-(2hydroxypropyl) ethylene diamine, di-(aminoethyl) diethylol methane, 3-aminoethyl-1 -pentanol, dibutyl isopropanol amine, Ν,Ν,Ν',Ν'-tetra-hydroxy trimethylene diamine, 2amino trimethylene glycol, 3-amino propylene glycol-1,2; 45588

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The reaction conditions employed in the step of condensing the aromatic carboxylic acid derivative with the polyalkylene polyamine or with the amino alcohol are such as to cause the splitting out of water through the formation of ester, amide, imide or amidine linkages. One or more of the amino groups of the polyamine or amino alcohol can enter into the amide, amidine, or imide-forming reaction while the OH groups will enter into an ester-forming reaction. Generally, the mole ratio of amino alcohol or polyamine to acid will range from about 1:5 to about 3:1, although it is preferred that this ratio be in the range of about one-half mole of polyamine or amino alcohol per carboxylic acid group up to about 2 moles of polyamine per carboxylic acid group. The reaction temperatures will generally be in the range of about 200° to about 400° F. In most cases, however, a narrower range of from about 250° to about 350° F. will be used. The reaction time will depend to some extend upon the reaction temperature. The composition of the reaction can be determined by measuring the amount of water that is split off during the reaction. Desirably, a water entraining solvent such as heptane or toluene is employed to assist in removing the water as an azeotrope.

Phosphite derivatives of the amide, imide, amidine, or ester products of this invention can also be prepared so as to impart wear reducing and oxidation inhibiting properties to those products. This reaction is generally carried out at a temperature between about 60° F. and about 250° F., preferably between about 120° F. and about 220° F. The reaction time varies, depending upon the reaction temperature employed, but generally is between about 1 hour and about 20 hours; most usually between about 3 hours and about 10 hours. The reaction mixture is then allowed to cool to ambient temperature and if a solvent has been used and it is desired to remove it, it is distilled off under atmospheric pressure or vacuum, as desired. This step would be unnecessary if a fuel oil or lubricating oil has been employed as the solvent to form a concentrate.

The ratios of phosphorous acid and the product of reaction of aromatic carboxylic acid and polyamine or amino alcohol can vary considerably but, in general, between about 0.1 and about 1.5 moles, preferably between about 0.5 and about 1 mole, of phosphorous acid per amino nitrogen present will be used.

The phosphite derivative can be prepared by either or two methods. In one case the condensation product of the aromatic carboxylic acid and the polyamine or amino alcohol is reacted with H₃PO₃ as outlined above. In the other, the alkylene polyamine or amino alcohol is first reacted with H₃PO₃and the resulting product is then reacted with the aromatic carboxylic acid. Reaction conditions in the second method are about the same as those in the first method. Reaction of H₃PO₃with the polyamine, amino alcohol, or ester or amide products is conducted in the liquid phase in the presence or absence of inert solvents.

For use as lubricating oil additives the reaction products of this invention will be incorporated in lubricating oil compositions in concentrations within the range of from about 0.1 to about 10 wt. percent and will ordinarily be used in concentrations of from about 0.1 to about 5 wt. percent. The lubricating oils to which the additives of the invention can be added include not only mineral lubricating oils, but synthetic oils also. The mineral lubricating oils may be of any preferred types, including those derived from the ordinary paraffinic, naphthenic, asphaltic, or mixed base mineral crude oils by suitable refining methods. Synthetic hydrocarbon lubricating oils may also be employed. Other synthetic oils include dibasic acid esters such as di-2-ethyl hexyl sebacate, carbonate esters, phosphate esters, halogenated hydrocarbons, polysilicones, polyglycols, glycol esters such as C₁₃ oxo acid diesters or tetraethylene glycol, and complex esters as for example the complex ester formed by the reaction of 1 mole of sebacic acid with 2 moles of tetraethylene glycol and 2 moles of 2ethyl hexanoic acid.

The additives of this invention can also be employed in middle distillate fuels for inhibiting corrosion and the formation of sludge and sediment in such fuels. Concentration ranges of from about 0.001 to about 2 wt. percent, or more generally from about 0.005 to about 0.2 wt. percent, are employed. Petroleum distillate fuels boiling in the range of from about 300° to about 900° F. are included. Typical of such fuels are No. 1 and No. 2 fuel oils that meet ASTM Specification D— 398—48T, diesel fuels qualifying as Grades ID, 2D and 4D of ASTM Specification D—975—5 IT, 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 can also be used in conjunction with other prior art ashless additives for fuels, such as polymers of acrylic or methacrylic acid esters, high molecular weight aliphatic amines, etc.

The additives of this invention can also be employed either alone or in combination with other hydrocarbon-soluble additives, in jet fuels and gasolines in concentrations ranging from about 0.001 to 1.0 wt. percent as detergent and/or rust preventive additives.

In either the fuel or lubricant compositions, other conventional additives may also be present, including dyes, pourpoint depressants, antiwear agents, e.g., tricresyl phosphate, or zinc dialkyl dithiophosphates of three to eight carbon atoms, antioxidants such as phenyl-alpha-naphthylamine, tert, octylphenol sulfide, or bis-phenols such as 4,4'-methylene bis (2,6-di tert, butylphenol), viscosity index improvers such as polymethacrylates, polyisobutylene, alkyl fumarate-vinyl acetate copolymers, and the like, as well as other dispersants.

The dispersant additives of the invention can be used to enhance the dispersancy-detergency of lubricants containing conventional detergents wherein the latter are used in concentrations in the range of about 0.5 to 5 wt. percent. When the conventional detergents or dispersants are metal-containing materials it is possible, by utilizing the additives of the present invention in combination therewith, to obtain added dispersancy or detergency without materially increasing the total ash-forming properties of the composition. Such metal-containing detergents or combination detergent-inhibitors include the alkaline earth metal salts as well as the aluminum, cobalt, lead, or tin salts of alkylated phenols or of alkylated phenol sulfides, wherein the alkyl groups have from five to 20 carbon atoms, e.g., the barium salt of phenol alkylated with tripropylene or the mixed barium-calcium salt of nonyl phenol sulfide. Other metal-containing detergents include oil-soluble alkaline earth metal salts of high molecular weight sulfonic acids obtained by sulfonating either natural or synthetic hydrocarbons. Specific examples of suitable sulfonates include calcium petroleum sulfonate, barium petroleum sulfonate, calcium di-C₉ alkyl benzene sulfonate (C₉ group from tripropylene), and barium C_le alkyl benzene sulfonate (C_l9group from tetraisobutylene). The sulfonates may be of either the neutral type or of the “over-based” or “high alkalinity” type, containing metal base in excess of that required for simple neutralization, wherein the excess metal base has been neutralized with carbon dioxide.

Other detergent additives include the reaction products of phosphosulfurized hydrocarbons with alkaline earth metal oxides or hydroxides, which can be prepared by first treating a hydrocarbon with a phosphorus sulfide and then reacting the product with an alkaline earth metal hydroxide or oxide, for example barium hydroxide, preferably in the presence of an alkyl phenol or an alkyl phenol sulfide and also preferably in the presence of carbon dioxide.

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The dispersants of this invention may also be used in conjunction with other ashless detergents or dispersants such as high molecular weight polymeric dispersants made with one or more polar monomers, such as vinyl acetate, vinyl pyrrolidone, methacrylates, fumarates and maleates. These 5 dispersants have molecular weights in the range of about 500 to 50,000. One example is a copolymer of 65 to 85 wt. percent of mixed C₉ to C₁₂ fumarates, 10 to 20 wt. percent of vinyl acetate, and 5 to 15 wt. percent of N-vinyl pyrrolidone. Another example is the copolymer derived by reaction of mixed tallow alcohol fumarates and C₈ oxo alcohol fumarates, averaging about 420 molecular weight, with vinyl acetate in a 3 to 1 acetate-fumarate ratio, and 3 wt. percent of maleic anhydride, followed by subsequent removal of excess vinyl acetate. By tallow alcohol fumarates is meant the esters of fumaric acid and the alcohols derived by hydrogenation of tallow. The latter are principally C_je and C₁₈ aliphatic alcohols with minor amounts of C₁₂, C₁₄ and C₂₀ alcohols. C₈ oxo alcohols are prepared by reaction of carbon monoxide and 20 hydrogen on mixed C₃ and C₄ olefins, followed by hydrogenation of the resulting aldehydes.

The nature of this invention will be further understood when reference is made to the following examples, which include a preferred embodiment. 25

EXAMPLE 1

The starting material for this preparation was a 50 wt. percent concentrate of a wax-alkylated naphthalene in a solvent neutral mineral lubricating oil that had a viscosity of 150 SUS ³⁰at 100° F. The wax-alkylated naphthalene had been obtained by chlorinating a crude paraffin scale wax of 125° to 127°F. melting point to a chlorine content of 14.5 wt. percent and thereafter condensing 200 grams of the chlorinated wax with 25.6 grams of naphthalene with the aid of aluminum chloride ³⁵catalyst.

A 100 gram portion of the wax-alkylated naphthalene concentrate was mixed with 8 grams of maleic anhydride and the mixture was heated under reflux at about 285° F. (140° C.) for ₄₀10 hours. The mole ratio of acid to aromatic hydrocarbon was about 1.6 to 1. Unreacted maleic anhydride was then removed from the mixture by blowing a stream of nitrogen through the mixture at 285° F. (140° C.) for 2 hours. A 100 gram portion of the reaction product was then reacted with 3 grams of 45 tetraethylenepentamine in the presence of 100 ml of heptane under reflux at a temperature of about 220° F. (105° C.) for 6 hours. The product was then filtered with the aid of diatomaceous earth. The final product concentrate contained about 50 wt. percent of actual additive. Analysis indicated 50 that the concentrate contained about 0.9 percent nitrogen by weight.

EXAMPLE 2

A mixture was prepared consisting of 100 grams of nonvolatile petrolenes, 100 grams of a solvent neutral mineral lubricating oil of 150 SUS viscosity at 100° F. and 15 grams of maleic anhydride. This mixture was heated for 10 hours at 480° F. (250° C.) after which excess maleic anhydride was gg stripped from the product by conducting through it a stream of nitrogen at 300° F. (150° C.) for 2 hours. A 150 gram portion of the reaction product was then treated with 4.5 grams of tetraethylene pentamine at a temperature of 250° F. (120° C.) for 6 hours. The final product concentrate, which contained ¢5 about 50 wt. percent of actual additive, had a nitrogen content of 0.94 percent by weight.

The non-volatile petrolenes used in the above preparation had an ASTM penetration at 77° F. of 88, a ring-and-ball softening point of 11° F., a Furol viscosity of 214 at 275° F., and 70 an average molecular weight of about 1217 as determined by vapor phase osmometry. The petrolenes were obtained by reducing a 16° API gravity Lagunillas crude oil under vacuum to a cut point of about 1,150° F. (atmospheric equivalent). The straight run residue thereby obtained had an ASTM 75 penetration of 5. This residue was deasphaltened by treatment with normal heptane, leaving the petrolenes as the unprecipitated asphaltene-free fraction. These petrolenes are designated as non-volatile because they are not volatile by distillation standards; in other words they are obtained from an asphalt residue that has been taken to the ultimate point by vacuum distillation.

EXAMPLE 3

For this preparation 800 grams of a 50 weight per cent concentrate of a condensation product of wax-alkylated naphthalene and maleic anhydride, prepared as in Example 1, was refluxed with 30 grams of ethylene dinitrilo tetraethanol [N,N,N',N'-tetrakis(2-hydroxyethyl) ethylene diamine] and 600 grams of heptane. After the mixture was heated under reflux for 5 hours, the solvent heptane was stripped from the product by heating the product on a steam bath and passing a stream of nitrogen through it. The final product concentrate had a nitrogen content of 0.24 percent by weight.

EXAMPLE 4

A mixture was prepared consisting of 41 grams of phosphorous acid, 354 grams of N,N,N',N'-tetrakis(2-hydroxyethyl) ethylenediamine, and 300 milliliters of heptane. This mixture was heated under reflux at 220° F. (105° C.) during which time 3 milliliters of water was collected in the reflux trap. The heptane was then stripped from the product by passing a stream of nitrogen through the product while it was heated on a steam bath. The product obtained had a nitrogen content of 10.44 wt. percent and a phosphorus content of 3.83 wt. percent. Using the procedure of Example 3, 800 grams of the condensation product of wax-alkylated naphthalene and maleic anhydride therein described was refluxed with 30 grams of the phosphite product just described, and 600 grams of heptane. After the mixture was heated under reflux for 5 hours, the solvent heptane was stripped from the product as in Example 3. The final product concentrate had a nitrogen content of 0.24 wt. percent.

EXAMPLE 5

A fully formulated, high detergency lubricating oil of SAE 10W-30 viscosity grade was prepared by blending 76 vol. percent of a solvent neutral lubricating oil of about 100 SSU viscosity at 100° F., 8 percent of a refined mineral lubricating oil of about 450 viscosity SSU at 100°F., 10 vol. percent of a 20 vol. percent concentrate of 15,000 molecular weight polyisobutylene V.I. improver, 1 vol. percent of an anti-wear additive concentrate, 0.5 vol. percent of a pour point depressant, 0.7 vol. percent of a high alkalinity calcium sulfonate concentrate to serve as an anti-rust agent, and 3.5 vol. percent of a commercial detergent inhibitor.

The anti-wear additive was an oil solution consisting of about 25 wt. percent of a mineral lubricating oil and about 75 wt. percent of mixed zinc dialkyl dithiophosphates prepared by treating a mixture of isobutanol and mixed amyl alcohols with P₂S₅ followed by neutralizing with zinc oxide. The overbased calcium sulfonate concentrate was derived from synthetic alkyl aromatic hydrocarbons of about 420 molecular weight. It had a total base number of about 300 and contained about 11.4 wt. percent calcium. The commercial detergent-inhibitor was a 70 wt. percent concentrate of a product obtained from 2 moles of polyisobutenyl succinic anhydride, 1 mole of tetraethylenepentamine, and 1 mole of acetic acid by heating them together at 300° F. for about 10 hours until no more water was evolved. The reaction product concentrate contained 2.2 wt. percent of nitrogen. The polyisobutenyl succinic anhydride had been derived from polyisobutylene of about 800 mol. wt. reacted with maleic anhydride.

A second fully formulated lubricating oil was prepared as above-described with the exception that in place of the 3.5 vol. percent of the commercial detergent, 3.5 vol. percent of the product concentrate of Example 1 was used.

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Each of the compositions was tested for sludge dispersing ability in a Cyclic Temperature Sludge Test which, from prior experience, has been shown to give sludge deposits similar to those obtained in stop-and-go driving such as would be experienced in taxicab operation. Briefly described, in this test a Ford 6-cylinder engine is run on a dynamometer stand through alternate cycles, the first cycle lasting 5 hours, at 1,500 rpm, and the second cycle lasting 2 hours, at the same operating speed, with the oil sump and water jacket temperatures being slightly higher in the second cycle than in the first. The two cycles are alternated in sequence until the desired total test time has elapsed. Make-up oil is added as required so as to maintain the oil level in the crankcase at all times between about 3½ and 4 quarts. At the end of selected periods of test time, the engine is inspected by disassembling it sufficiently to permit visual examination of several of the parts, including the rocker arm assembly, the rocker arm cover, the cylinder head, the push rod chamber and its cover, the crankshaft and the oil pan. These parts are visually and quantitatively rated for sludge deposits, using a CRC Sludge Merit rating system in which a numerical rating of 10 represents a perfectly clean part, and the numerical scale decreases to a minimum value representing a part covered with the maximum amount of sludge possible. The several merit ratings are averaged to give an overall engine merit rating.

The results of the cyclic temperature sludge test are summarized in Table I. It will be seen from these results that the additive product of the present invention was superior to the prior art material in its ability to disperse sludge.

TABLEI

105 Hr. Sludge Merit Rating

Prior Art Material 5.8

Dispersant of Example 1 8.8

EXAMPLE 6

A fully formulated lubricating oil composition was prepared similar to that in Example 5 with the exception that 75 volume percent of the solvent neutral oil of 100 SSU viscosity was used, the amount of the V.I. improver concentrate was 10.6 volume percent, the amount of calcium sulfonate concentrate was 0.9 volume percent and the amount of commercial detergent inhibitor was 3.8 volume percent. This composition was compared in the cyclic temperature sludge test with a composition in which 3.8 volume percent of the concentrate of Example 2 was substituted for the 3.8 volume percent of commercial detergent inhibitor. The results of the cyclic temperature sludge test after 63 hours and after 84 hours are given in Table II which follows. These results show that the additive product of Example 2 was equally as effective as the commercial detergent inhibitor.

TABLE II Sludge Merit Ratings

Hours 84 Hours

Commercial Detergent Inhibitor 9.26 6.8

Dispersant of Example 2 9.25 6.6

EXAMPLE 7

Fully formulated high detergency lubricating oil blends of a nature similar to those in Example. 5 were prepared by blending 74.2 wt. percent of solvent neutral lubricating oil of about 100 SSU viscosity at 100° F., 7.7 wt. percent of refined mineral lubricating oil of about 450 SSU viscosity at 100° F., 10.1 wt. percent of the V.I. improver described in Example 5, 0.5 wt. percent of a pour point depressant, 1.45 wt. percent of the high alkalinity calcium sulfonate concentrate described in Example 5, 1.3 wt. percent of the anti-wear additive described in Example 5, and 4.74 wt. percent of the detergent-dispersant

1® additive to be tested. In one case the blend contained the commercial detergent inhibitor described in Example 5 and, in the other three cases, the blends contained respectively the concentrates whose preparation is described in Examples 1,3 and 4.

Each of the blends prepared as described was subjected to an MS Sequence VB Engine Test. This test was run in a Lincoln engine and the procedure used is well known in the automotive industry. It is described in the publication entitled “Engine Test Sequence For Evaluating Automotive Lubricants For API Service MS” which is ASTM Special Technical Publication 315—D. At the end of each test, various parts of the engine are rated on a merit basis wherein 10 represents a perfectly clean part, and lesser numbers represent increasing degrees of deposit formation. The various ratings are then totaled and averaged on a basis of 50 as a perfect rating. For example, seven separate engine parts are each rated individually on a basis of 10 for each perfectly clean part, the seven ratings are added and the overall sludge rating is fivesevenths of the total. The results obtained with the blends described above are given in the following Table III.

TABLE III

MS Sequence VB Test Results

<td> Additive in Blend</td><td> Merit Ratings (Basic 50) Sludge Merit</td><td> Total Varnish Merit</td>

<td> Commercial Additive</td><td> 40.6</td><td> 36.9</td>

<td> Product of Example 1</td><td> 42.8</td><td> 39.3</td>

<td> Product of Example 3</td><td> 40.4</td><td> 41.0</td>

<td> Product of Example 4</td><td> 39.6</td><td> 40.1</td>

It will be noted that each of the products of the present invention that were tested was better with respect to varnish formation than was the commercial detergent inhibitor. With respect to sludge formation, the product of Example .1 was slightly better than the commercial product and the product of Example 3 was about equal in its performance to the commercial material in this respect. The product of Example 4, i.e., the phosphite derivative, was only slightly inferior to the commercial material, indicating that the imparting of anti-wear and antioxidant properties to the sludge dispersant entails little or no loss in sludge dispersing ability.

As stated earlier, the products of this invention can be used in fuels as well as in lubricants. For example, about 0.01 wt. percent of the product concentrate of Example 4 can be added by simple mixing to a leaded gasoline for the purpose of imparting rust preventive properties and carburetor detergency action thereto: The gasoline has an initial boiling point of 90? F., a 50 percent point of 208° F., and a final boiling point of 378° F. (ASTM D—86), and contains 17 vol. percent aromatics, 13 vol. percent olefins, and 70 vol. percent saturated hydrocarbons. As a further example, about 0.02 wt. percent of the product concentrate of Example 1 can be added to a heating oil comprising a middle distillate petroleum fuel having a boiling range of about 360° to 680° F., to serve as a dispersant.

It is within the scope of this invention to prepare additive concentrates in which the concentration of additive is greater than would normally be employed in a finished lubricant or fuel. These concentrates may contain in the range of from 10 to 80 percent of additive on an active ingredient basis, the balance being oil or fuel. Such concentrates are convenient for handling the additive in the ultimate blending operation into a finished lubricating oil or fuel composition. The additive concentrates can be made up simply of an additive of the present invention in a suitable mineral oil medium or they can include other additives that are intended for use along with the additives of the invention in a finished composition. Thus, if the additives are to be used in conjunction with conventional detergents, an additive concentrate can be prepared containing say 30 to 60 wt. percent of an additive of the invention and

101044

0110

3,676,483 to 20 wt. percent of a metal sulfonate, e.g., calcium petroleum sulfonate from sulfonic acids of about 450 molecular weight, or a metal alkylphenol sulfide, e.g., calcium nonylphenol sulfide, with the balance being a mineral lubricating oil. Additionally, 5 to 15 wt. percent of an antiwear agent such as a zinc dialkyldithiophosphate, e.g., mixed zinc butyl and amyl dithiophosphates may also be present in the additive concentrate package.

While the lubricant compositions herein described are primarily designed as internal combustion engine crankcase lubricants, the additives of the invention may also be employed in other oil compositions, including turbine oils, various industrial oils, gear oils, hydraulic fluids, transmission fluids and the like.

It is to be understood that the examples presented herein are intended to be merely illustrative of the invention and not as limiting it in any manner; nor is the invention to be limited by any theory regarding its operability. The scope of the invention is to be determined by the appended claims.