US 3821302 A
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United States Patent Hu 0 l 1 OLEFINIC KETONE [MINES AND OIL COMPOSITIONS CONTAINING THEM  Inventor: Shih-En Hu, Westfield, NJ.
 Assignee: Esso Research and Engineering Company, Linden, NJ.
22 Filed: Aug. 1, 1969 211 Appl. No.: 846,980
Related U.S. Application Data  Continuation-impart of Ser. No. 502,438, Oct. 22,
 U.S. Cl. 260/566 R, 260/268 R, 260/934,
OTHER PUBLICATIONS House, Modern Synthetic Reactions, pp. 94-95(l965).
[111 3,821,302 June 28, 1974 Primary Examiner-Bernard Helfin Assistant Examiner-Gerald A. Schwartz Att0rney,-Agent, 0r Firm-Byron O. Dimmick  ABSTRACT A multifunctional additive for an oil from the class consisting of gasoline, middle distillate petroleum fuels, mineral lubricating oils, and synthetic lubricating oils is prepared by reacting an aliphatic polyamine such as diethylene triamine, tetraethylene pentamine, and the like with an unsaturated] ketone that has been prepared by the mild Oxidation of a terminal olefin having from 12 to 250 carbon atoms. The reaction involves the formation of a Schiff base from the carbonyl group of the ketone and an amino group of the aliphatic polyamine. Modified products can be prepared by treating the unsaturated ketone with a sulfide of phosphorus, e.g., P 8 or with a dihydrocarbyl dithiophosphoric acid prior to the step of reacting the ketone with the aliphatic polyamine.
6 Claims, N0 Drawings ()LEFINIC KETONE [MINES ANT) 01L COMPOSITIONS (IONTAINING THEM This application is a continuation-in-pait of Ser. No. 502,438, filed Oct. 22, 1965 now abandoned.
FIELD OF THE INVENTION The present invention concerns multifunctional additives for oil compositions including gasolines, fuel oils, heating oils, and lubricating oils. The invention is also directed to the preparation of these additives and to oil compositions containing them. The additives can be characterized as oil-soluble imine or Schiff base derivatives of high molecular weight unsaturated ketones.
Numerous addition agents are known in the prior art for improving the desirable properties of fuels and lubricants, including high oxidation resistance, freedom from the formation of insoluble material, protection from rust and corrosion, and the like. For heavy duty service in high compression internal combustion engines, it is required that the lubricants contain additives that will impart good dispersancy and detergency as well as good oxidation stability. By dispersancy is meant the prevention of the deposition of insoluble material and by detergency is meant the quality of removing deposits where they have been formed. Recent emphasis in this field of additives has been placed on development of metal-free additives that will not form an ash. The conventional metal-containing additives have the disadvantage of leaving an ash residue which tends to accumulate in the combustion chamber of the engine and cause spark plug fouling, valve burning, preignition, and similar undesirable conditions. Ash-free dispersants are also of advantage in diesel fuels, fuel oil compositions, and gasolines as well. Additives that will function not only as good dispersants and detergents but that will additionally furnish protection from wear and from rust and corrosion are of particular value.
DESCRIPTION OF THE INVENTION In the above formula, R represents the remainder of the starting olefin. When this vinyl alkyl ketone is con densed with an aliphatic polyamine, an imine is formed which may be represented by the following formula:
In the above formula, R has the same meaning as in the previous formula, R is selected from the group consisting of hydrogen and C to C alkyl groups, and x is a number from I to 10.
The starting materials for the preparation of the unsaturated ketones are aliphatic terminal olefins having from about 12 to about 250 carbon atoms, and preferably from about 16 to about 180 carbon atoms. Such olefins can be obtained from a number of sources, most commonly by the cracking of paraffin wax or by the polymerization or copolymerization of C to C monoolefins, e.g., ethylene, propylene, butylene, isobutylene, or pentene. These long chain olefins can be straight chain or branched chain, but they must be terminal olefins, i.e., those containing 21%11 group. Representative olefin polymersthat can be oxidized include a propylene polymer averaging about 36 carbon atoms per molecule, an ethylene polymer of about 2,000 molecular weight, a copolymer of about weight percent ethylene and about 30 weight percent propylene of about 3,000 number average molecular weight, and a polyisobutylene of about 1,800 molecular weight. Ethylene-propylene copolymers of molecular weights within the range used in this invention are described in British Pat. No. 993,744. Low molecular weight polymers of aliphatic alpha olefins of 10 to 28 carbon atoms can also be oxidized for use in this invention. See U.S. Pat. No. 3,252,771. Polymers of C to C mono-olefins, and especially of is-obutylene, of average molecular weights within the range of about 400 and 2,500 are particularly useful.
It is evident that in most instances the ketones will be mixtures of ketones of a range of molecular weights.
The oxidation of the olefin to form a vinyl alkyl ketone is most conveniently effected by the use of air or other oxygen-containing gas mixtures in the presence of a suitable catalyst. The latter include oxides of manganese, selenium, and chromium as well as C, to C,-, aliphatic acid salts of such metals, such as manganese acetate. Oxidation by air blowing can be conducted at temperatures ranging from about F. to about 480F. for from about 2 to 48 hours in the presence of from about 0.2 to about 10 wt. percent of catalyst; preferably at 250F. to about 350F. for from abrut 6 to 24 hours in the presence of from about 0.5 to 5 wt. percent of catalyst. Catalyst may be removed from the product very readily by filtration.
The ketone obtained by the oxidation of the olefin is converted to a Schiff base derivative by reacting the ketone with an alkylene polyamine. Generally, the mole ratio of polyamine to ketone will range from about 0.2 to l to about 1.5 to 1, although it is preferred that this ratio be in the range from about 0.5 mole of polyamine per ketone up to about 1.0 mole of polyamine per ke tone. The reaction temperature will generally be in the range from about 140F. to about 350F. In most cases, however, a narrower range of from about 180F. to about 250F. will be used. The reaction time will depend to some extent on the reaction temperature. The composition of the reaction mixture can be determined by measuring the amount of water that is split off during the reaction. it is usually advantageous to employ a water-entraining solvent such as iheptane, benzene, or toluene to remove the water as an azeotrope. Reaction will require from i to 48 hours, but will usually be complete in from about 2 to 12 hours.
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:
NHxcHa, NmcHan... HZ
wherein n is 2 to 4 and m is a number from to 10. Specific compounds coming within the formula include diethylene triamine, triethylene tetramine, tetraethylene pentamine, dibutylene triamine, dipropylene triamine, octaethylene nonamine, and tetrapropylene pentamine. N,l\l-di-(2-aminoethyl) ethylene diamine can also be used. Other aliphatic polyamine compounds that can be used include the N-aminoalky'l piperazines of the formula:
wherein n is a number 1 to 3, and R is hydrogen or an aminoalkyl radical containing 1 to 3 carbon atoms. Specific examples include N-(2-aminoethyl) piperazine, N-(2-aminoisopropyl) piperazine, and N,N'-di- (2-aminoethyl)piperazine. I
Still other alkylene amino compounds that can be used include dialkylamino alkyl amines such as dimethylamino methyl amine, dimethylamino propyl amine, methylpropylamino amyl amine, etc. These may be characterized by the formula:
wherein R is an alkylene radical, e.g., an ethylene, propylene, or butylene radical, and R and R are C to C alkyl radicals.
Thus, the alkylene polyamine or aliphatic polyamine compounds used in this invention can be broadly characterized as alkylene amino compounds containing two to 12 nitrogen atoms wherein pairs of nitrogen atoms are joined by alkylene groups of from two to four carbon atoms.
The use of mixtures of alkylene polyamines, dialkylamino alkyl amines, mixtures of N-aminoalkyl piperazines, and mixtures of the alkylene polyamines with the N-aminoalkyl piperazines is also contemplated.
The Schiff base derivatives of the present invention may be modified to impart antiwear and antirust properties by incorporating therein phosphorus thioacid groups. One method of accomplishing this is to form an addition compound between the unsaturated ketone and a dihydrocarbyl dithiophosphoric acid. Preferably, the ketone is reacted with the dithiophosphoric acid prior to the step of forming the imine. More or less equal molar proportions of the two reactants are reacted at a temperature in the range of from about 60F. to about 300F. or more particularly from about 100F. to about 200F. The reaction time may take from 4 to '30 hours, depending somewhat on the reaction temperature and it may be promoted with a catalyst such as tert. butyl perbenzoate. It is believed that the adduct that is formed results from attachment of the acidic sulfur atom of thedithi ophosphoric acid to the double bond of the unsaturated ketone, giving a compound of the following formula:
In the above formula R has the same meaning as in the previous formulas and R" is the hydrocarbon group of the dihydrocarbon dithiophosphoric acid that is used in preparing the adduct. R" may be the same or different hydrocarbon radicals including aryl, alkyl, aralkyl, and cycloalkyl radicals. These radicals may have from one to 20 carbon atoms, and preferably have from one to 12 carbon atoms each. Examples of suitable dihydrocarbyl dithiophosphoric acids include diisobutyl dithiophosphoric acid, lauryl phcnol dithiophosphoric acid. mixcd ethyl isopropyl dithiophosphoric acid. ditcrtinry octyl dithiophosphoric acid. mixed isopropyl mm dithiophosphoric acid, dilauryl dithiophosphoric acid, mixed isobutyl primary amyl dithiophosphoric acid, diphenyl dithiophosphoric acid, mixed dithiophosphoric acids derived from mixed alcohols from paraffin wax oxidation, mixed hexyl stearyl dithiophosphate, mixed isopropyl C oxo dithiophosphoric acid and mixed dithiophosphates derived from mixed C to C alcohols known as Lorol" alcohols and so forth.
The phosphorus thioacid function can also be introduced into the ketone by treatment of the unsaturated ketone with a sulfide of phosphorus, preferably with P 5 The ketone may be reacted with from about 5 to about 40 wt. percent of the phosphorus sulfide and is preferably treated with from, about 10 to 30 wt. percent of the sulfide of'phosphorus. Reaction temperatures 'will be in the range of from about 100F. to about 260F. or more preferably from about 160F. to about 230F. with reaction times of from 0.5 to 10 hours or more usually of from about 1 to 6 hours.
The nature of this invention will be further understood when reference is made to the following examples, which include preferred embodiments.
EXAMPLE 1 The starting material for this preparation was a cut of higher olefins containing from 20 to 28 carbon atoms. The cut contained wt. percent alpha-olefins, 6 percent of other olefins, and 4 percent of saturated hydrocarbons, and predominated in C hydrocarbons (93%).' It had a specific gravity of 0.798 at 68F. A suspension of 10 grams of manganese dioxide in 500 grams of the olefins was prepared and was subjected to constant agitation. Air was passed through the agitated suspension for 24 hours at 330F. At the end of this time the mixture was filtered to remove the maganese dioxide. The yield of product was 450 grams. Strong carbonyl bands at 5.85 millimicrons were found upon infrared analysis, indicating that ketones had been formed.
The product of oxidation was converted to an imine by mixing 90 grams of the above ketone product with 10 grams of tetraethylene pentamine and grams of heptane and heating the resulting mixture under reflux for 6 hours, during which time 1 gram of water was collected in the reflux trap. The reaction product was filtered and then stripped of heptane. A dark brown viscous product was obtained in a yield of 85 grams.
EXAMPLE 2 A mixture was prepared consisting of 10 grams of manganese dioxide and 400 grams of polyisobutylene The product of oxidation was converted to an imine by mixing 25 grams of the oxidized material with 25 grams of a solvent neutral lubricating oil of 150 SUS tained in a yield of 350 grams and was found on analysis to have a nitrogen content of 2.62 wt.
To one portion of a lubricating oil base stock of SAE.
30 viscosity rating there was added by simple mixing 1 wt. percent of the product of Example 5. To another viscosity at 100F. and 1.25 grams of tetraethylene pentamine and heating the mixture at 250F. (120C.) for 8 hours. The reaction product had a nitrogen content of 0.88 wt. percent.
r The oxidation step of Example 2 was repeated, again using 400 grams of 960 mol. wt. polyisobutylene and grams of manganese dioxide. The reaction time was 24 hours and the reaction temperature was about 390 395F. (200C) In the same manner as in Example 2, the product of oxidation was converted to an imine or Schiff base, but
. in this case using different proportions of the ketone EXAMPLE 4 A cut of C olefins obtained by the cracking of paraffin wax was air oxidized in the manner described in Example l. The olefin'cut contained 80 wt. alphaolefins and Ste 6 wt. percent of aromatic hydrocarbons. Branched chain aliphatic hydrocarbons were present in the equivalent-of 1.3 methyl groups per molecule. A 100-gram portion of the air-oxidized product was reacted with 24 grams of P 8 at 212F. The P 8 was added gradually over a period of 3 hours. The P 8 treated product was mixed with 100 grams of heptane and with grams of tetraethylene pentamine. The mixture was heated under reflux for 12 hours, after which time the reaction product was filtered and then stripped of heptane. The yield of product was 120 grams.
EXAMPLE 5 For this-preparation mixed dialkyl dithiophosphoric acids were employed which were obtained by treating a mixture of isobutanol and mixed amyl alcohols with P 8 A mixture wasprepared consisting of 43 grams of the mixed dialkyl dithiophosphoric acids, 300 grams of the unsaturated ketone product from C to C olefin oxidation used in Example 1, 200 grams of heptane and 4 grams of tertiary butyl perbenzoate. This mixture was heated at 185F. for 20 hours under an atmosphere of nitrogen. Then 30 grams of tetraethylene pentamine were added and the mixture was heated under reflux at 230F. Four milliliters of water were collected at the end of the reaction. The heptane was then stripped from the product. The solvent-free material was obportion of the same base oil there was added 1 wt. per cent of a zinc dialkyl dithiophosphatc concentrate, which was an oil solution consisting of about 25 wt. percent mineral lubricating oil and about 75 wt. percent of zinc dialkyl dithiophosphates. prepared by zinc oxide neutralization of the mixed dialkyl dithiophosphoric acids employed in Example 5.
These two compositions were subjected to the Falex wear test, which involves running the test compositions in a Falex wear testing machine for 30 minutes at 500 pounds direct gauge reading. The results obtained are given in the following Table I.
It will be seen from Table I that the additive of Example 5 was superior to a conventional zinc dialkyl dithiophosphate with respect to wear reduction.
EXAMPLE '7 The additive concentrates obtained as described in Example 2 and 3 were mixed with separate portions of a used lubricating oil (described below) in 0.5 wt. percent concentration, thus effecting the incorporation of about 0.25 wt. percent of actual additive. Another blend was prepared by adding to another portion of the same oil about 0.5 wt. percent of a commercial dispersant concentrate, the dispersant being the imide ob tained by condensing 2.8 moles of polyisobutenyl succinic anhydride with one mole of tetraethylene pent amine. The polyisobutenyl succinic anhydride was derived from about 1,000 average molecular weight polyisobutylene. The commercial additive concentrate contained about wt. percent active ingredient, thus the used oil blend contained 0.25 wt. percent of actual dispersant additive. a
All of the used oil blends thus prepared were sub- 50 jected to a sludge dispersancy bench test which had been found, after a large number of evaluations, to be an excellent screening test for lubricating oil dispersant additives.
The sludge dispersancy bench test was conducted in the following manner. The medium chosen for the sludge test was a used oil (original viscosity about 325 SUS at F.) that had been run in a fleet of taxicabs in New York City. This used oil contained a fine dispersion of actual engine sludge. About 10 ml. of each of the blends described above, i.e., blends of the test additives in the used oil described, was placed in a centrifuge tube and then centrifuged in a conventional centrifuge for one hour at 3,600 rpm. It was observed that after this period of time a sludge-free region with a closely defined boundary formed at the top of the centrifuge tube. The relative length of this sludge-free region with respect to the total length of the sample in the centrifuge tube was determined. The lower the percentage of oil separation, the better the additive is as a dispersant. The used oil alone gave greater than 90 percent separation into a clear oil layer. The various blends of used oil and additive gave the results shown It is seen from the data that the products were at least equally as effective as the imide dispersant of the prior art as dispersing agents for sludge in a crankcase lubricant.
EXAMPLE 8 Using as the base oil a mineral lubricating oil having a viscosity of 325 SUS at 100F. and a viscosity index of about 100, a reference blend was prepared by simple mixing of 3.5 wt. percent ofa commercial detergent inhibitor, 0.9 wt. percent of a zinc dialkyl dithiophosphate antiwear additive and 95.6 wt. percent of the base oil.
Test compositions were prepared by simple mixing of 3.5 wt. percent of the same detergent inhibitor, 0.9 wt. percent of the same antiwear additive and 93.6 wt. percent of the same base oil as in the-reference blend along with 1 wt. percent of the product of Example 1.
The commercial detergent inhibitor mentioned above was a mineral oil solution containing an additive prepared by reacting a mixture of a phosphosulfurized polyisobutylene and nonyl phenol with barium hydroxide pentahydrate and blowing the reaction mixture with carbon dioxide. The approximate analysis of the concentrate was 27 wt. percent of phosphosulfurized polyisobutylene, 11.7 wt. percent nonyl phenol, 10.6 wt. percent barium oxide, 2.5 wt. percent carbon dioxide, and 48.2 wt. percent of mineral oil.
The zinc dialkyl dithiophosphate antiwear additive was an oil solution consisting of about 25 wt. percent of mineral lubricating oil and about 75 wt. percent of zinc dialkyl dithiophosphate prepared by treating a mixture of isobutanol and mixed amyl alcohols with P 5 followed by neutralizing with zinc oxide.
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 3 k and 4 quarts. At the end of selected periods of test time, the engine is inspected by disassembling it sufiiciently 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 Ill. lt will be seen from these results that the additive product of Example I greatly increased the ability of the oil composition to disperse sludge.
TABLE III Sludge Merit Ratings Cyclic Temperature Test Reference Blend Plus Test Hours Reference Blend Additive of Example 1 The additives of this invention may be employed in concentrations ranging from'about 0.002 to about 10 wt. percent in oil compositions ranging from gasoline fractions through middle distillate fuels and lubricating oils.
For use as lubricating oil additives the reaction prodnets of this invention may be incorporated in lubricating oil compositions in concentration ranges of from about 0.] to about 10 wt. percent on an actual ingredient basis, 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 may 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, naphthe nic, 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 C oxo acid diesters of tetraethylene glycol, and complex esters as for example the complex ester formed by the reaction of 1 mole of sebac ic acid with 2 moles of tetraethylene glycol and 2 moles of 2-ethyl hexanoic acid.
The additives of this invention may 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 0.002 to about 2 wt. percent, or more generally, from about 0.005 to about 0.2 wt. are employed. Petroleum distillate fuels boiling in the range of from about 300F. to about 900F. are contemplated. Typical of such fuels are No. l and No. 2 fuel oils that meet ASTM Specification D-396- 48T, diesel fuels qualifying as Grades lD, 2D and 4D of ASTM Specification D-975-51T, 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. Thus, for instance, about 0.04 wt. percent of the product of Example 1 can be added to a heating oil comprising a mixture of cracked and straight run distillates having a boiling range of about 350 to 680F. These additives may 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 may also be employed either alone or in combination with other hydrocarbonsoluble 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. Thus, about 0.007 wt. percent of the concentrate of Example 2 can be added to a leaded gasoline to impart carburetor detergency' action thereto. The gasoline contains 3 cc. of lead tetraethyl per gallon and has an initial boiling point of 85F, a 50 percent point of 205F. and a final boiling point of 380F.
In either the fuel or. lubricant compositions, other conventional additives may also be present, including dyes, pour-point depressants, antiwear agents, e.g., tricresyl phosphate, zinc dialkyl dithiophosphates of three to eight carbon atoms, antioxidants such as phenylalpha-naphthylamine, tert. octylphenol sulfide, bisphenols 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. Thus, a compounded lubricant suitable for use as a crankcase oil can be prepared by blending intoa light mineral lubricating oil base stock sufficient viscosity index improver (e.g., 15,000 molecular weight polyisobutylene) to place it in the SAE l0W-30 viscosity class along with 0.8 wt. percent of a high alkalinity calcium synthetic alkyl aromatic sulfonate of 11.4 wt. percent calcium content and 300 total base number, 0.5 wt. percent of a pour point depressant (wax-alkylated naphthalene) and 1.8 wt. percent of the product of Example l.
The dispersant additives of the invention may be employed 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 ispossible, 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 metalcontaining detergents or combination detergent inhibitors include the alkaline earth metal salts of alkylated phenols or of alkylated phenol sulfides, as for example barium-calcium nonyl phenol sulfide, the so-called basic alkaline earth metal sulfonates, and dispersions of barium carbonate or calcium carbonate in mineral oils containing various surfactants such as phosphosulfurized polyolefins, for example. Specific examples of suitable sulfonates include calcium petroleum sulfonate, barium petroleum sulfonate, calcium di-C alkyl benzene sulfonate (C 'group from tripropylene) and barium C 16 alkyl benzene sulfonate (C group from tetraisobutylene). The sulfonates may be of either the neutral type or of the over-based" or high alkalinity type. Metal salts of alkyl phenols and of the corresponding alkyl phenol sulfides that are ordinarily employed as detergents are those derived from phenols having alkyl groups of from five to 20 carbon atoms. Specific examples are barium tert. octyl phenol sulfide,
1 l0 and the barium salt of the alkylation product of phenol with tripropylene.
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.
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 dispersants have molecular weights in the range of about 500 to 50,000. One example is a copolymer of 65 to wt. percent of mixed C to C fumarates, 10 to 20 wt. percent of vinyl acetate, and 5 to 15 wt. percent of N-vinyl pyrrolidone.
It is within the contemplation of this invention to prepare additive concentrates in which the concentration of additive is greater than would normally beemployed in a finished lubricant. These concentrates may contain inthe range of from 10 to 80 percent of additive on an active ingredient basis, the balance being a hydrocarbon oil, usually a mineral oil. S uch concentrates are convenient for handling the additive in the ultimate blending operation into a finished lubricating oil composition. The additive concentrates may be made up simply of an additive of the present invention in a suitable mineral oil medium or they may include other additives that are intended for use along with the additives of the invention in a finished lubricant.
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, in-
cluding turbine oils, various industrial oils, gear oils, hydraulic fluids, transmission fluids and the like.
It is to be noted that in the present invention the existence of the double bond in the vinyl alkyl ketone provides an additional site for reaction with amino groups as compared with a saturatedketone, thus incorporating additional amino groups into the additive and thereby imparting greater dispersancy. Furthermore, in this Michaels addition type of reaction at the double bond, both primary and secondary amino groups can be reacted, whereas only primary amino groups. can react with the keto groups. Thus, with a vinyl alkyl ketone there is much more opportunity for reaction with aliphatic polyamines then when using saturated ketones.
What is claimed is:
l. A Schiff base soluble in an oil selected from the class consisting of gasoline, middle distillate petroleum fuels and lubricating oils, and imparting dispersant properties to said oil which comprises the product obtained by reacting, at a temperature of from about F. to about 350F., and for a time sufficient to split out water and effect the necessary reaction, from 0.2 to 1.5 moles of an aliphatic polyamine withone mole of an alkyl vinyl ketone having from 16 to about 180 carbon atoms that has been obtained by the mild oxida tion of a terminal olefin of the same number of carbon atoms, said aliphatic polyamine being selected from the ll 1 class consisting of N,N-di-(2-aminoethyl) ethylene diamine, alkylene polyamines having the formula:
wherein n is 2 to 3 and m is a number from to 10, and N-aminoalkyl piperazines of the formula:
wherein said ketone is a mixture of ketones derived from a polymer of a C to C monoolefin.
3. An oil-soluble Schiff base as defined by claim l wherein said ketone is a mixture of ketones derived by the oxidation of polyisobutylene of average molecular weight within the range of about 400 to 2,500.
4. An oil-soluble Schiff base as defined by claim 1 wherein said ketone is a mixture of ketones derived from the olefins of cracked paraffin wax.
5. An oil-soluble Schiff base as defined by claim 1 wherein said ketone is a mixture of ketones of from 20 to 28 carbon atoms.
6. An oil-soluble Schiff base as defined by claim 1 wherein said aliphatic polyamine is tetraethylene pentamine.