Polyether substituted mannich bases as fuel and lubricant ashless dispersants

Abstract: Reaction products in which polyethers are grown from substituted phenol-containing Mannich bases have been found to be effective ashless dispersants and detergents for fuels and lubricants. The reaction products of the invention are obtained by (1) reacting phenol or a C₁ to about a C₄₀ alkylphenol with a suitable primary or secondary amine and a C₁ to about a C₃₀ aldehyde, thereafter (2) reacting the resultant intermediate product of (1) with an alkali metal or alkali metal salt thereof, and then (3) reacting the product of (2) with a C₂ to about a C₈ alkylene epoxide or mixtures thereof to produce a polyether-substituted Mannich base.

Description: Background of the Invention This application is directed to products derived from polyether modified phenol-containing Mannich bases which are highly useful as ashless dispersants when small amounts thereof are combined with hydrocarbon fuels, or lubricating oils. The invention accordingly relates to a process according to independent claim 1. The products obtained from that process can be used lubricants or liquid fuels to improve the detergent characteristics thereof and to improve fuel consumption in internal combustion engines. Those skilled in the art know that additives impart special properties to the lubricants and fuels to which they have been added. They may provide new properties or they may enhance properties already present. It is also well known that under the severe driving conditions with respect to the operating temperatures of internal combustion engines and to weather conditions as well, sludge and other deposits form in the crankcase and in the oil passages of gasoline or diesel engines which severely limits the ability of the oil to lubricate the engine. Accordingly, there is a constant search and need for new and improved additives which will not only improve lubricity, but maintain cleanliness and disperse sludge formations. Products containing both polyether and amine fragments are known dispersants as disclosed in U.S. Patents 4,234,321, 4,261,704 and 4,696,755. Unlike the present invention, the '755 patent describes growing polyether groups off saturated aliphatic alcohols and using the products as lubricant oil dispersants; the '704 patent describes the preparation of polyoxyalkylene polyamines by reacting a polyoxyalkylene polyol or glycol with a halogen-containing compound; and the '321 patent describes an additive produced by a hydrocarbylpoly(oxyalkylene) alcohol with phosgene and certain polyamines. It is also well known in the art to employ nitrogen-containing dispersants and/or detergents to overcome or at least alleviate the above mentioned problems. U.S. Patent 4,696,755 is directed to lubricating oils containing an additive useful for its dispersancy and detergency characteristics comprising hydroxy polyether amines. U.S. Patent 4,144,034 discloses the use of a reaction product of a polyether amine and maleic anhydride as a carburetor detergent. U.S. Patent 3,309,182 discloses polyether diamines as sludge inhibitors in petroleum distillate fuels. U.S. Patent 4,717,492 is directed to the reaction products of Mannich bases with amines, thiols or dithiophosphoric acids. It has now been found that polyether groups or polyoxyalkylene groups can be grown off the phenol portion of Mannich bases to provide dispersency characteristics for both lubricant and fuel compositions. According to one aspect of the present invention there is provided a process for making a polyether substituted Mannich base, as defined in claim 1. Further features of the reaction are defined in the dependent claims. According to another aspect of the reaction there is provided a process for preparing a lubricant composition, as defined in claim 12. The amine portion of the molecule may contain any primary or secondary amines and combinations thereof, for example, diethylene triamine, triethylene tetramine, tetraethylene pentamine, and pentaethylene hexamine and the corresponding propylene amines, and mixtures of the above. Useful amines include but are not limited to amines such as N-oleyl diethylenetriamine, N-soya diethylenetriamine, N-coco diethylenetriamine, N-tallow diethylenetriamine, N-tetradecyl diethylenetriamine, N-octadecyl diethylenetriamine, N-eicosyl diethylenetriamine, N-triacontyl diethylenetriamine, N-oleyl dipropylenetriamine, N-soya dipropylenetriamine, N-coco dipropylenetriamine, N-tallow dipropylenetriamine, N-decyl dipropylenetriamine, N-dodecyl dipropylenetriamine, N-tetradecyl dipropylenetriamine, N-octadecyl dipropylenetriamine, N-eicosyl dipropylenetriamine, N-triacontyl dipropylenetriamine, the corresponding N-C₁₀ to C₃₀ hydrocarbyl dibutylenetriamine members as well as the corresponding mixed members such as, for example, the N-C₁₀ to C₃₀ hydrocarbyl ethylenepropylenetriamine, N-C₁₀ to C₃₀ hydrocarbyl ethylenebutylenetriamine and N-C₁₀ to C₃₀ hydrocarbyl propylenebutylenetriamine. Preferred are tetraethylene pentamine, triethylene tetramine and diethylene triamine. Any suitable phenol or C₁ to C₄₀ alkylphenol may be used, for example, nonyl phenol or dodecyl phenol. Alkylphenols having from 1 to 16 carbon atoms are suitably employed. Any suitable C₂ to C₈ alkylene epoxide or mixtures thereof may be used in the process described herein. Preferred are propylene oxide, butylene oxide and mixtures thereof. Any suitable C₁ to C₃₀ aldehyde may be used; preferred are alkyl or aryl aldehydes. The alkali metal salt may be a potassium salt, particularly potassium hydroxide. The alkali metal may be potassium or sodium. The alkali metal salt or alkali metal can be reacted with the Mannich base intermediate product at a temperature and for a time sufficient to form a salt which is then reacted with a suitable epoxide, or mixture of epoxides. The general reaction conditions for making the Mannich base are not critical. Reaction between the phenol, the amine and the aldehyde can take place at temperatures varying from about 65 to about 130°C for up to about 4 to 10 hours, but where required by the specific reactants employed, up to 24 hours may be used for the completion of the reaction. The molar ratio of the alkylphenol to amine to aldehyde may vary widely, preferably from about 1.0:1.0:1.0 to about 3.0:1.0:3.5, and the molar ratio of Mannich base to alkali metal or alkali metal salt is from about 1.0:0.8 to about 1.0:3.5. In the reaction to grow the polyethers off the Mannich base salt, molar ratios may also vary widely, preferably from about 1.0:10.0 to about 1.0:100.0 of Mannich base alkali metal salt to alkylene oxide. Hydrocarbon solvents or other inert solvents may be used if so desired. In general, any hydrocarbon solvent can be used in which the reactants are soluble and which can, if the products are soluble therein, be easily removed. Examples thereof include benzene, toluene and xylenes. An important feature of the invention is the ability of the additives to improve the detergency/dispersancy qualities of oleaginous materials such as lubricating oils, which may be either a mineral oil, a synthetic oil, or mixtures thereof, or a grease in which any of the aforementioned oils are employed as a vehicle. The product of this invention can be added to a lubricant in an amount of about 0.1% to 10% by weight of the total composition. In general, mineral oils, both paraffinic, naphthenic or mixtures thereof, may be employed as a lubricating oil or as the grease vehicle. The mineral oils may be of any suitable lubricating viscosity range, such as for example, from about 45 SSU at 37.8°C. (100°F) to about 6000 SSU at 37.8°C. (100°F), and preferably from about 50 to about 250 SSU at 98.9°C. (210°F). These oils may have viscosity indices ranging up to about 100 or higher. Viscosity indices from about 70 to about 95 are preferred. The average molecular weights of these oils may range from about 250 to about 800. Where the lubricant is to be employed in the form of a grease, the lubricating oil is generally employed in an amount sufficient to balance the total grease composition, after accounting for the desired quantity of the thickening agent and other additive components to be included in the grease formulation. A wide variety of materials may be employed as thickening or gelling agents. These may include any of the conventional metal salts or soaps, which are dispersed in the lubricating vehicle in grease-forming quantities in an amount sufficient to impart the desired consistency to the resulting grease composition. Other thickening agents that may be employed in the grease formulation may comprise the non-soap thickeners, such as surface-modified clays and silicas, aryl ureas, calcium complexes and similar materials. In general, grease thickeners may be employed which do not melt and dissolve when used at the required temperature within a particular environment; however, in all other respects, any material which is normally employed for thickening or gelling hydrocarbon fluids for forming grease can be used in preparing the aforementioned improved grease in accordance with the present invention. In instances where synthetic oils are desired, various classes of oils may be successfully utilized. Typical synthetic vehicles include polyisobutylenes, polybutenes, hydrogenated polydecenes, polypropylene glycol, polyethylene glycol, trimethylol propane esters, neopentyl and pentaerythritol esters, di(2-ethylhexyl) sebacate, di(2-ethylhexyl) adipate, dibutyl phthalate, fluorocarbons, silicate esters, silanes, esters of phosphorus-containing acids, liquid ureas, ferrocene derivatives, hydrogenated synthetic oils, chain-type polyphenyls, siloxanes (polysiloxanes) and silicones, alkyl-substituted diphenyl ethers exemplified by a butyl-substituted bis(p-phenoxy phenyl)ether and phenoxy phenylethers. In preparing greases using synthetic oils, any thickeners known to the art (including some of those mentioned hereinabove) can be used. It is to be understood that the lubricant compositions contemplated herein can also contain other materials. For example, corrosion inhibitors, extreme pressure agents, viscosity index improvers, coantioxidants, antiwear agents and the like can be used. These include, but are not limited to, phenates, sulfonates, succinimides, zinc dialkyl dithiophosphates, and the like. These materials do not detract from the value of the compositions prepared by the process of this invention; rather such materials serve to impart their customary properties to the particular compositions in which they are incorporated. The products prepared by the process of this invention can also be employed in liquid fuels such as hydrocarbon fuels, alcohol fuels or mixtures thereof, including mixtures of hydrocarbons, mixtures of alcohols and mixtures of hydrocarbon and alcohol fuels to reduce friction and improve fuel economy. About 11.3 kg (25 pounds) to about 226.8 kg (500 pounds), or preferably about 22.7 to 90.7 kg (about 50 to 200 pounds), of additive per thousand barrels (158,980 liters) of fuels for internal combustion engines may be used. Liquid hydrocarbon fuels include gasoline, fuel oils, diesel oils and oxygenated fuels such as gasohol, alcohols and ethers are examples of alcohol fuels. The additives in accordance herewith are particularly useful in unleaded fuels. Other additives such as octane boosters, friction modifiers, stabilizers, antirust agents, demulsifiers, metal deactivators, dyes and the like can be used with the detergent/dispersant additive of the invention in the fuel compositions. In general, the reaction products prepared by the process of the present invention may be used in any amount which is effective for imparting the desired degree of detergency/dispersancy characteristics and resulting fuel economy improvements. The following examples represent illustrations of the invention. They are illustrative only and are not meant to limit the invention. EXAMPLE 1 Nonylphenol, 440.8 grams (2.0 mol.), and 103.2 grams (1.0 mol.) of diethylene triamine were charged to a 1 liter reactor equipped with a N₂ inlet, mechanical stirrer, thermometer, and Dean Stark trap. The mixture was heated to 70°C under a blanket of N₂. A total of 63.0 grams (2.1 mol.) of paraformaldehyde was added in four equal portions over 90 minutes. The mixture was heated to 110°C for two hours. About 24 milliliters of water were collected in the Dean Stark trap. A further 12 milliliters of water were collected upon stripping the mixture under house vacuum (250-300 mm Hg) at 110°C for two hours. The resulting viscous material was purified by hot filtration through celite. Nitrogen analysis: 6.8% EXAMPLE 2 The procedure of Example 1 is followed to prepare the Mannich base with the following exception: 189 grams (1.0 mol.) of tetraethylene pentamine is substituted for diethylene triamine. Nitrogen analysis: 7.9% EXAMPLE 3 The procedure of Example 1 is followed to prepare the Mannich base with the following exception: 524 grams (2.0 mol.) of dodecyl phenol is substituted for nonylphenol. Nitrogen analysis: 5.6% EXAMPLE 4 56.8 grams (0.1 mol.) of the product from Example 1 and 200 milliliters of toluene were charged to a one liter reactor equipped with a N₂ inlet, mechanical stirrer, thermometer, and Dean Stark trap. The solution was refluxed for 16 hours. It was then cooled to room temperature and 7.4 grams (0.19 mol.) of potassium metal were added, causing the evolution of H₂. The reaction was heated to 50°C for 24 hours under a N₂ purge, at which time no potassium was evident. The toluene was distilled off through the Dean Stark trap until a pot temperature of 150°C was reached. The reaction was cooled to about 90°C, and the Dean Stark trap was replaced with a condenser and an addition funnel charged with 288.4 grams (4.0 mol.) of butylene oxide which was added over three hours, keeping the reaction temperature above 85°C. When the refluxing ceased, the reaction was transferred to a separatory funnel with 150 milliliters of n -butanol and was washed with 3x100 milliliter portions of water. The butanol was removed via rotary evaporation and the resulting product was filtered through celite. The product was analyzed by IR and NMR (¹H and ¹³C). The spectra were consistent with the proposed product composition. Nitrogen analysis: 1.1% EXAMPLE 5 The procedure of Example 4 is followed to prepare the polyether substituted Mannich base with the following exception: one half the amount of butylene oxide is used. Nitrogen analysis: 1.9% EXAMPLE 6 56.8 grams (0.1 mol.) of the product from Example 1 and 200 milliliters of toluene were charged to a one liter reactor equipped with N₂ inlet, mechanical stirrer, thermometer, and Dean Stark trap. The solution was refluxed for 16 hours and cooled to room temperature. 21.3 grams (0.19 mol.) of potassium t-butoxide was added and the mixture was heated at 75°C for two hours. The Dean Stark trap was replaced with a distillation head and the toluene and t-butyl alcohol were stripped under house vacuum (250-300 mm Hg) at a temperature of up to about 100°C. The distillation head was replaced with a condenser, and an addition funnel charged with 288.4 grams (4.0 mol.) of butylene oxide was attached to the reactor. The butylene oxide addition and workup were as described in Example 4. Nitrogen analysis: 1.1% EXAMPLE 7 23.0 grams of (0.04 mol.) of the product from Example 1, 4.8 grams of 88% KOH (0.075 mol.), and 125 milliliters of toluene were charged to a 500 milliliter reactor equipped with a N₂ inlet, mechanical stirrer, thermometer, and Dean Stark trap. The solution was refluxed for four hours, during which time about 1.6 milliliters of water were collected. The toluene was then distilled off through the Dean Stark trap up to 110°C. The Dean Stark trap was replaced with a distillation head and the remaining toluene and water were stripped under house vacuum (250-300 mm Hg) up to a temperature of 100°C. The distillation head was replaced with a condenser and an addition funnel charged with 115.4 grams (1.6 mol.) of butylene oxide was attached to the reactor. The butylene oxide addition and workup were done as described in Example 4. Nitrogen Analysis: 1.1% EXAMPLE 8 The procedure of Example 7 is followed to prepare the polyether-substituted Mannich base with the following exception: the Mannich base from Example 2 is substituted for the Mannich base from Example 1. Nitrogen Analysis: 2.0% EXAMPLE 9 The procedure of Example 7 is followed to prepare the polyether-substituted Mannich base with the following exception: the Mannich base from Example 3 is substituted for the Mannich base from Example 1. Nitrogen Analysis: 1.1% EXAMPLE 10 The procedure of Example 7 is followed to prepare the polyether-substituted Mannich base with the following exception: 0.92 mol. propylene oxide is substituted for the 1.6 mol. butylene oxide. Nitrogen Analysis: 1.7% EXAMPLE 11 The procedure of Example 7 is followed to prepare the polyether-substituted Mannich base with the following exception: 3.0 mol. propylene oxide is substituted for the 1.6 mol. butylene oxide. Nitrogen Analysis: 0.8% EVALUATION OF THE COMPOUNDS Selected products of the reaction in accordance with the invention were evaluated by the CRC Carburetor Cleanliness Test in Philips J Unleaded Fuel, using the procedure outlined in CRC (Coordinating Research Council) Report No. 529. The results of the tests can be found in the following Table which shows the percent of clean-up accomplished by the selected examples. The above results clearly demonstrate that additive compounds in accordance with the present invention provide excellent detergent/dispersancy characteristics to fuel compositions.

Claims: A process for making a polyphenol substituted Mannich base comprising (1) reacting a phenol or a C₁ to C₄₀ alkylphenol with a primary or secondary polyamine and a C₁ to C₃₀ aldehyde, thereafter (2) reacting the resultant Mannich base intermediate product of (1) with an alkali metal or alkali metal salt, and then (3) reacting the product of (2) with a C₂ to C₈ alkylene epoxide or mixtures thereof to produce a product having at least one or more of the structures described below: where x is 1 to 6; y and z are 0 to 50 and y + z equals 10 to 100; R¹ is hydrogen or C₁ to C₄₀ hydrocarbyl or aryl group; R² and R³ are independently hydrogen or C₁ to C₆ hydrocarbyl; and R⁴ is a nitrogen-containing hydrocarbyl group; and R⁵ and R⁶ are independently hydrogen, C₁ to C₃₀ hydrocarbyl or aryl or a nitrogen-containing hydrocarbyl group. A process according to any preceding claim wherein the molar ratio of the alkylphenol to polyamine to aldehyde is from 1.0:1.0:1.0 to 3.0:1.0:3.5. A process according to any preceding claim wherein the molar ratio of the Mannich base to the alkali metal or alkali metal salt is from 1.0:0.8 to 1.0:3.5. A process according to any preceding claim wherein the molar ratio of the Mannich base alkali metal salt to the alkylene epoxide or mixture of alkylene epoxides is from 1:10 to 1:100. A process according to any preceding claim wherein the alkyl phenol comprises nonyl phenol or dodecyl phenol. A process according to any preceding claim wherein the aldehyde comprises formaldehyde or paraformaldehyde. A process according to any preceding claim wherein the epoxide comprises butylene oxide, propylene oxide, or a mixture of propylene oxide and butylene oxide. A process according to any preceding claim wherein the alkali metal is sodium or potassium. A process according to claim 8 wherein the alkali metal salt comprises potassium hydroxide. A process according to any preceding claim wherein the polyamine comprises diethylene triamine, triethylene tetramine, tetraethylene pentamine, and pentaethylene hexamine and the corresponding propylene polyamines. A process for preparing a lubricant composition comprising preparing a polyether substituted Mannich base by a process according to any preceding claim and blending a major proportion of a liquid fuel or an oil of lubricating viscosity or grease or other solid lubricant prepared therefore with a minor detergent/dispersant amount of said polyether substituted Mannich base. A process according to claim 11 wherein the major proportion of the composition is an oil of lubricating viscosity or grease prepared therefrom. A process according to a claim 11 or 12 wherein the oil comprises a mineral oil, synthetic oil or a mixture of fraction thereof. A process according to any of claims 11 to 13 containing from 0.1% to 10% by weight of the reaction product. A process according to claim 11 wherein the major proportion of the composition is a liquid hydrocarbon fuel. A process according to claim 15 wherein the fuel is a gasoline or an oxygenated fuel. A process according to claim 16 wherein the oxygenated fuel comprises gasohol, alcohols, ethers or a mixture thereof. A process according to claim 16 wherein the gasoline is an unleaded gasoline. A process according to any of claims 15 to 18 having from 11.3 to 226.8 kg of reaction product per 1000 barrels (158,980 liters) of fuel.

Inventors: BLAIN DAVID ALAN, CARDIS ANGELINE BAIRD, BLAIN, DAVID ALAN, CARDIS, ANGELINE BAIRD
Applicants: MOBIL OIL CORP, MOBIL OIL CORPORATION
Application year: 1990
Main classification: C10M159
IPC codes: C10L1, C10M159, C10L10, C10N10, C10M149, C07C213, C10N30, C07C217, C10N50, C10N40