US3723501A - Lubricant containing an alkali metal ketone salt and acrylonitrile - Google Patents

Abstract

Dialkyl ketones having a relatively long oil soluble alkyl group are condensed as their anions with an acrylonitrile under mild conditions to provide lubricating oil detergent additives and emulsifiers.

Description

United States Patent [191 DeVries Mar. 27, 1973 [54] LUBRICANT CONTAINING AN ALKALI [561' 7 References Cited figgfifi UNITED STATES PATENTS 3,267,111 8/1966 Vill ..260/465.9 [75] Invent Lou's Devms Rlchmond 3,471,547 10/1969 Evans et a1. .....26o 465.3 x [73] Assignee; Chevron Rmrch Company S 3,449,400 6/1969 Evans et al. ..260/465.9

Francisco, Calif. Pnmary Examiner-Joseph P. Brust Flled! J 1970 Att0meyJ. A, Buchanan, Jr., G. F. Magdeberger, C. [21] AppL No; 54,077 J. Tonkm and B. G. Fehrmger Related US. Application Data ABSTRACT [62] Division of Sen No'.749314 Aug 1, 1968' Dialkyl ketones having a relatively long oil soluble alkyl group are condensed as their anions with an acrylonitrile under mild conditions to provide lubricat- [52] 333351 53331? ing oil detergent additives and emulsifiers. [51] Int. Cl .......C07c 121/00 7 Claims, No Drawings [58] Field of Search ..260/465.9, 465.8

LUBRICANT CONTAINING AN ALKALI METAL KETONE SALT AND ACRYLONITRILE CROSS-REFERENCE TO RELATED APPLICATIONS This application is a divisional of application Serial No. 749,314, filed August 1, 1968.

BACKGROUND OF THE INVENTION tion of deposits.

Moreover, because of usual marketing practices, the additives should be effective over a broad range of conditions: the additives should be stable under the hot conditions of the diesel engine, as well as provide detergency and dispersancy over the more variable temperature conditions in the automobile engine.

The detergent must not have deleterious eflects, such as corrosion, oxidation initiation, etc., which cannot be easily and economically inhibited. Also, any additive which is used in lubricating oils, which are frequently heavily compounded, must be compatible with the other additives included in the oils. These additives are oxidation inhibitors, viscosity index improvers, corrosion inhibitors,-extreme pressure additives, etc. v

2. Description of the Prior Art Numerous patents have issued on .ashless detergents having nitrogen as the polar portion of the molecule. These patents include U. S. Pat. No. 3,219,666, which is concerned with carboxamides of polyamines; U. S. Pat. No. 3,275,554, which is concerned with hydrocarbon substituted alkylene polyamines; and U. S. Pat. No. 3,328,297, which is concerned with aliphatic sulfarnides of polyalkylene polyamines. I 7

These ashless detergents show excellent detersive capability while avoiding the presence of metals which tend to result in metal deposits.

SUMMARY OF THE INVENTION Pursuant to this invention, lubricating oil detergents and emulsifiers are prepared by combining the anion of a di-alkyl ketone, having a relatively'long chain alkyl group with an acrylonitrile under mild conditions, wherein at least 1 acrylonitrile molecule is condensed onto the dialkyl ketone.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 2 (Kiow 5 wherein M is an alkali metal of atomic number in the v (waatml wherein M, R and R are as defined previously and is equivalent to R. Alternatively the alkali metal salt may be a mixture of the two possible alkali metal salts. Depending on the rate at which the two alkali metal salts .react with acrylonitrile, one or two products may result. When R is disubstituted alpha to the carbonyl or highly hindered at the alpha position, only one alkali metal salt will result. I v

In referring to acrylonitrile, it is intended to include a-alkyl substituted acrylonitriles where the alkyl group is of from one to two carbon atoms, i.e., methyl or ethyl. These acrylonitriles have the formula wherein Y is hydrogen or alkyl of from one to carbon atoms, preferably hydrogen.

The acrylonitrile will be used in an amount of at least 1 mole of acrylonitrile per mole of alkali metal-salt and usually not exceeding 10 moles, more usually in the range of l to 6 moles, and, preferably, in the range of 2 to 5 moles.

The acrylonitrile may be added batchwise or incrementally to the alkali metal salt. Preferably, the acrylonitrile is added incrementally with vigorous stirring so as to obtain relatively homogeneous diffusion of the acrylonitrile into the reaction mixture. Usually, the reaction is carried out in an inert solvent. These solvents may be polar or nonpolar (hydrocarbon).

Illustrative hydrocarbon solvents include benzene,

toluene, cumene, tert.-butyl benzene, preferably, aromatic hydrocarbons of from six to 10 carbon atoms. Other solvents include ethers, both aliphatic and aromatic, etc. Individual solvents or mixed solvents may be used.

The concentration of the alkali metal salt in the solvent may vary from 1 weight percent to 80 weight percent, more usually of from about 10 to weight percent.

The temperature for the condensation of the acrylonitrile with the alkali metal salt will generally be at least lC. and usually of from about 0 to 6020C, preferably from about 10 to 45C. Elevated temperatures are not desirable in that they may lead to undesirable poly-condensation products.

The time for the addition of the acrylonitrile to the alkali metal salt will vary widely, depending on the method of addition, the amounts employed and the equipment available. Times may vary from 5 minutes to 24 hours, more usually being fromabout 30 minutes to 6 hours.

The final product will generally have at least about 0.5 weight percent nitrogen and more usually in the range of about 1 to 5 weight percent nitrogen.

The condensation of alkali metal salts of Ketones and acrylonitrile is described in an article by Adams & Hauser, J. Am. Chem. Soc. 66 1220 (1944).

The ketone alkali metal salt can be prepared by the reaction of any convenient alkali metal base with a dialkyl ketone having at least 1 a-hydrogen. Conveniently, the ketone can be reacted with an alkali metal amide or alkali metal hydride with escape of ammonia or hydrogen, respectively. Or, the ketone may be reacted with a metal complex, such as metal-aromatic hydrocarbon complexes, e.g., sodium naphthalene, sodium biphenyl, etc. Usually, from about 0.9 to 1.5 equivalents of the base will be added per mole of ketone.

Conveniently, the reaction is carried out in an inert solvent, usually an aromatic hydrocarbon solvent. The solvents have been described previously for use in the condensation of acrylonitrile and the anion. The temperature for the reaction will generally be in the range of about 0 to 50C. The concentration of the ketone in the solvent will generally be of from about 10 to 70 weight percent.

The reaction is easily followed by the evolution of gas. When no further gas is evolved, acrylonitrile, heat or in solution, may then be added to the alkali metal salt. Isolation of the alkali metal salt is not required.

The ketone used to form the alkali metal salt is readily prepared by the ozonization of asymmetrical secondary olefins. By asymmetrical secondary olefins is intended an olefin being disubstituted on one of the ethylene carbon atoms. Of course, the olefin may be tertiary or quatemary, which inherently includes the secondary olefin.

The ketones which find use will, for the most part, have the following formula:

wherein R is an alkyl group of at least 25 carbon atoms, usually from about 45 carbon atoms to 200 carbon atoms. R is an oil solubilizing group, generally having at least 1 branch per four carbon atoms along the chain and more usually at least 1 branch per two carbon atoms along the chain. Particularly preferred groups are polypropenyl and polyisobutenyl obtained from polypropenyl and polyisobutenyl polymers. Other R groups may include ethylene/propylene copolymers, ethyleneisobutylene co-polymers, l-butene polymers, etc. Their branches will generally be of from one to two carbon atoms, more usually one carbon atom, i.e., methyl.

When ozonization is used as the method of preparation of the ketone, the ketone will generally be free of other sites of olefinic unsaturation. However, one or more sites of olefinic unsaturation may be present, when the other olefinic site is more highly hindered than the olefin, which it is desired to cleave.

Usually, no more than one site of unsaturation will be present, and more usually, the alkyl groups will be saturated.

R and R are hydrogen or lower alkyl of from one to three carbon atoms, usually of only one carbon atom and, preferably, hydrogen.

The method of ozonization is described in an article by J. J. Pappas, Tetrahedron Letters 36 4273 (1966). By this method, the olefin is dissolved in an inert solvent containing a hydroxylic solvent, such as methanol and ozone passed through the solution at temperatures below 0C. When the equivalent amount of ozone has been introduced into the solution, the addition of ozone is stopped, and the solution sparged with nitrogen. Then 1 equivalent of methyl sulfide per equivalent of olefin is added and the volatile materials stripped.

EXAMPLES The following examples are offered by way of illustration and not by way of limitation:

EXAMPLE A Into a 1-liter flask with fritted glass inlet was charged 120 g. of polyisobutylene (approximately 1,000 av. mol. wt.) in 400 ml. of dichloromethane containing 2 equivalent weights (based on polyisobutylene) of methanol. The solution was cooled to 20C. and 1 equivalent weight of ozone sparged through the solution over a period of about 8 hours. At the end of this time, the ozone addition was stopped, and the solution sparged with nitrogen for 1 hour. To the solution was then added, in small excess over stoichiometric, 1 equivalent weight of dimethyl sulfide and the solution allowed to warm to room temperature. When sufficient time had passed, the solvent was stripped under reduced pressure (2 mm. Hg), and the residue purified by twice reprecipitating in acetone from pentane.

The product was analyzedby an infrared spectrum which showed the characteristic carbonyl peak.

' EXAMPLE 1 Into a reaction vessel was charged 1.4 g. of sodium amide in 50 ml. of benzene. To the mixture was added dropwise at room temperature 12 g. of a product prepared as described in Example A (ketone derived from polyisobutylene of approximately 1,000 average molecular weight) in 50 ml. of benzene; the mixture was stirred at room temperature for 20 hours. A slow evolution of gas occurred. At the end of this time, 1.91 g. of acrylonitrile in ml. of ether was added, using ra'pid stirring and a dropping funnel with a capillary inlet extending under the surface of the liquid in order to obtain very slow and continuous addition. The product was then precipitated 3 times in methanol from a pentane solution.

An aliquot of the product was chromatographed on a small alumina column. The material which was eluted with pentane weighed 4.2 g. (40.5 weight percent). The material eluted with 25 percent ether/75 percent pentane was 3.65 g. (35.2 weight percent). Finally, the product eluted with 5 percent methanol/95 percent pentane was 2.5 g. (24.3 weight percent).

The analysis of the original product (unchromatographed) is as follows: C, 81.2; H, 13.03; M, 3.24.

EXAMPLE II Into a reaction vessel was introduced 500 g. of ketone derived from polyisobutylene of approximately 1,000 average molecular weight (prepared as described in Example A) in toluene. The toluene was azeotroped to remove any water. Nitrogen gas was introduced to provide a nitrogen atmosphere and 63.0 g. of sodium amide added, and the reaction mixture allowed to stir for 64 hours. The product was then filtered under nitrogen into a receiver and diluted to a total volume of 2.5 liters with toluene.

To the toluene solution was then added 79.5 g. of acrylonitrile in 1,500 ml. of toluene. The addition was carried out dropwise through a capillary with rapid stirring to provide a maximum dispersion of the acrylonitrile in the toluene solution. The reaction mixture remained clear throughout the addition. When the addition was complete, the solvent was stripped along with unreacted acrylonitrile, the pressure being reduced to 2 mm. Hg. The residue was then dissolved in pentane, the product reprecipitated with methanol, and the solid redissolved in pentane. The product was then isolated and analyzed: C, 80.6; H, 12.61; N, 3.82; O, 3.6.

EXAMPLE III Into a reaction vessel was introduced 410 g. of a ketone derived from polyisobutylene of approximately 1,000 average molecular weight (prepared as described in Example A) in 1,000 m1. of benzene. To the solution under nitrogen was added 48 g. of sodium amide and the mixture allowed to stir for 24 hours, at which time the evolution of gas had'ceased. The mixture was then filtered into a receive under nitrogen and to the filtrate added dropwise 65.2 g. of acrylonitrile in 500 ml. of benzene. Some heat of reaction was noticed, the temperature rising to a maximum of 35C. At the end of the addition, the mixture was allowed to settle, filtered, the filtrate diluted with 4 volumes of pentane, then chilled to 0C. and filtered. The volatiles were removed by reducing the pressure to 2 mm. Hg. The residue was analyzed: C, 81.33; H, 12.33; N, 2.96; O, 2.17.

EXAMPLE IV Into a reaction vessel was introduced 25 ml. of dry tetrahydrofuran, 2.36 g. (1 equivalent weight) naphthalene and 0.425 g. 1 equivalent weight) sodium and the mixture stirred at room temperature for about one hour, when all of the sodium had dissolved. To the solution was then added 50 g. (1 equivalent weight) of a ketone derived from polyisobutylene of approximately 2,700 average molecular weight (prepared as described in Example A). When the color of the solution was discharged, 250 ml. of dry toluene was added.

While rapidly stirring the solution, 5.9 g. (6.0 equivalent weight) of acrylonitrile was added slowly. At the end of the addition, the mixture was stirred for an additional hour and then methanol added. The product was purified by repeated dissolving of the product in pentane and precipitation with methanol.

The product was then isolated and freed of volatile materials.

Use of the Compositions in Lubricating Oils As already indicated, the compositions of this invention find use as detergents and dispersants in lubricating oil and are found to be effective under a wide variety of conditions; not only under the hot conditions of the diesel engine, but the much more variable temperature conditions of the automobile engine.

The compositions of this invention may be formulated with various lubricating fluids (hereinafter referred to as oils) which are either derived from natural or synthetic sources. Oils generally have viscosities of from about 35 to 50,000 Saybolt Universal Seconds (SUS) at 100F.

Among natural hydrocarbonaceous oils are paraffin base, naphthenic base, asphaltic base and mixed base oils. Illustrative of synthetic oils are: hydrocarbon oils such as polymers of various olefins, generally of from two to eight carbon atoms, and alkylated aromatic hydrocarbons; and non-hydrocarbon oils, such as polyalkylene oxides, aromatic ethers, carboxylate esters, phosphate esters, and silicon esters. The preferred media are the hydrocarbonaceous media, both natural and synthetic.

The above oils may be used individually or together whenever miscible or made so by the use of mutual solvents.

When the detergents of this invention are compounded with lubricating oils for use in an engine, the detergents will be present in at least about 0.1 weight percent and usually not more than 20 weight percent, more usually in the range of about 1 to 10 weight percent. The compounds can be prepared as concentrates due to their excellent compatibility with oils. As concentrates, the compounds of this invention will generally range from about 10 to weight percent, more usually from about 20 to 50 weight percent of the total composition. 1

A preferred aspect in using the compounds of this invention in lubricating oils is to include in the oil from about 1 to 50 mM./kg. of a dihydrocarbyl phosphorodithioate, wherein the hydrocarbyl groups are from about four to 36 carbon atoms. Usually, the hydrocarbyl groups will be alkyl or alkaryl groups. The remaining valence of the phosphorodithioate will usually be satisfied by zinc, but polyalkyleneoxy or a third hydrocarbyl group may also be used. (Hydrocarbyl is an organic radical composed solely of carbon and hydrogen which may be aliphatic, alicyclic, aromatic or a combination thereof.)

Other additives may also be included in the oil such as pour point depressants, oiliness agents, antioxidants, rust inhibitors, etc. Usually, the total amount of these additives will range from about 0.1 to 10 weight percent, more usually from about 0.5 to 5 weight percent.

The individual additives may vary from about 0.01 to 5 weight percent of the composition.

In order to demonstrate the effectiveness of the compositions of this invention under extremely severe engine conditions, the composition of Example ll was compounded at 4 weight per cent in a Mid-Continent SAE 30 neutral oil. Also included were 12 mM./kg. of a common oxidation inhibitor, zinc 0,0dialkylphenyl phosphorodithioate (the alkyl groups are of from 12 to 15 carbon atoms).

The test used is a particularly severe test which is referred to as the 240-BMEP (Brake Mean Effective Pressure) Caterpillar Test. The conditions are for a supercharged Caterpillar Test, wherein the pressure of the supercharged air is 76.5 in. Hg abs., the water temperature of the cooling jacket is 200F., the air temperature is 100F., the oil temperature of the bearing is 190F., the sulfur content of the fuel is 0.4 weight percent, the speed of the engine is 1,000 r.p.m., and the rate of fuel input is at a rate which provides 6,900 B.T.U.s per minute. The test was carried out for 120 hours, the engine being rated at both 60 and 120 hours. The results are reported as follows:

TABLE I Hours Groove Deposits Land Deposits 60 47-4-O.5-0.3 190-30-10 120 83-l3-0.8-0.2 465-75-15 Rated 0400, 100 being completely clean, being completely filled. Rated 0-800, 800 being completely black.

The exemplary composition was also tested for its effect on piston varnish in what is referred to as a Ford varnish engine test. A highly compounded oil was used, having the following formulation: 1.47 weight per cent of Example II; 50 mM./kg. calcium as a calcium carbonate overbased calcium mahogany sulfonate; l5 mM./kg. of zinc, 0,0-dialkyl phosphorodithioate (alkyl of from four to six carbon atoms). The oil used was a mixture of Sunray DX 250 neutral oil and Sunray DX 150 bright stock in a 6.16/1 weight ratio.

The test was carried out with a 6-cylinder Ford having a 240 cubic inch displacement. The engine conditions are the same as the cyclic conditions of the ASTM sequence 5 B test. The engine conditions are stressed by using a dirty fuel which is comprised of 30 volume percent of a FCC heavy cut having a boiling range of from 25 3 to 424F. with 70 volume percent of a commercial regular grade gasoline. The fuel has 2 ml. per gallon of lead and approximately 0.1 weight per cent sulfur. The crankcase depression is maintained at one inch water. The engine run is carried out for 60 hours.

The piston varnish rating was 6.3 on the basis of 0 to l0, 10 being clean. This compared favorably to commercially available ashless detergents in being a comparable varnish rating.

It is evident from the above results that the compositions of this invention are effective lubricating oil detergents under extremely severe temperature and oxidative conditions. Furthermore, they are compatible with other common additives included in lubricating oil. The compositions are also emulsifiers and may be used to prepare water-in-oil emulsions.

I claim:

1. Compositions containing from 0.5 to 5 weight percent nitrogen prepared by combining an alkali metal salt of a ketone of the formula a. wherein said alkali metal is of atomic number 3 to b. R represents an alkyl having from 25 to 200 carbon atoms; and

c. R and R each represent hydrogen or lower alkyl of from one to three carbon atoms, with from 1 to 10 moles of an acrylonitrile per mole of said salt, at a temperature in the range of from -10C. to 60C. for from 5 minutes to 24 hours.

2. A composition according to claim 1, wherein said combining is carried out in the presence of an inert solvent.

3. A composition according to claim 1, wherein R is of from 45 to 200 carbon atoms, R and R are hydrogen, and said alkali metal is sodium.

4. A composition according to claim 3, wherein said acrylonitrile is present in from 2 to 5 moles per mole of anion.

5. A composition according to claim 1, wherein said acrylonitrile is present in from 2 to 5 moles and the weight percent nitrogen of the final product is in the range of 1 to 5.

6. A composition according to claim 5, wherein R and R are hydrogen, the said combining is carried out in the presence of an inert hydrocarbon solvent and the concentration of the salt is in the range of 10 to weight percent.

7. A composition according to claim 1, wherein R is polyisobutenyl.

zg gg UNITED STATES PATENT OFFICE CERTIFICATE OF RRECTION Patent'No. 2.72%J501 Dated March 27, 197% Inventor(s) LOUIS- DEVRIES It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

, 9 t d u 6 G01. 2, line 1, (RccR R should read -(RCCR R DP.

. I I R1 o Col. 2, line 17, R'C-C-CH-R2) should read Y {Y I /Y Col. 2, line Mo, "GHQ-C should read --CH2==C cN \CN Col. 2, line Mk, w "from 1 to carbon, should read ---from 1 to 2 carbon.

Col. 3, line 3, from about 0 to 6020 0., should read ,--'-from about 0 to 60C.'--.

Col 5, line /7, "into a receive", should read -j--into a receiver-.

Q01. 7, line 19, .speed of the engine is 1,000", should read --speed of the engine is 1,200--.

L Signed and sealed this 31st day of July 1973 (SEAL) Attest:

EDWARD M.PLETCHER,JR. RENE-D... 'TEGTMEYER Attestijng Officer 7 Acting Commissionef of Patents

Claims (6)

1. 2. A composition according to claim 1, wherein said combining is carried out in the presence of an inert solvent.
2. 3. A composition according to claim 1, wherein R3 is of from 45 to 200 carbon atoms, R4 and R5 are hydrogen, and said alkali metal is sodium.
3. 4. A composition according to claim 3, wherein said acrylonitrile is present in from 2 to 5 moles per mole of anion.
4. 5. A composition according to claim 1, wherein said acrylonitrile is present in from 2 to 5 moles and the weight percent nItrogen of the final product is in the range of 1 to 5.
5. 6. A composition according to claim 5, wherein R4 and R5 are hydrogen, the said combining is carried out in the presence of an inert hydrocarbon solvent and the concentration of the salt is in the range of 10 to 70 weight percent.
6. 7. A composition according to claim 1, wherein R3 is polyisobutenyl.