US 3888776 A
Description (OCR text may contain errors)
United States Patent 11 1 1111 3,888,776 Silverstein June 10, 1975  TWO'CYCLE ENGINE OIL FOREIGN PATENTS OR APPLICATIONS Inventor: Jo p J- Silverslein, Long Island 1,227,726 2/1963 Germany 44/53 C1ty, N.Y. l,075,237 7/1967 United Kingdom 44/58  Assignee: The Ore-Lube Corporation, New OTHER PUBLICATIONS York Kirk-Othemer, Encyclopedia of Chem. Tech.,"  Filed: Feb. 12, 1973 1966, p. 658, Vol. 10, 2nd Edition.  Appl. No: 331,488 Chemical Progress, March 1962, p. 6 Slipping and Sliding,
52 us. c1. 252/25;445512;/;1;/751E Primary Examiner Delbert E Gamz Assistant ExaminerAndrew H. Metz  Int. Cl. C10m 3/02; ClOl l/lO 58 Field Of Search..... 252/25, 32.7 E, 52 R, 52 A; Ammey Agent [ms sears 44/51, 58
 ABSTRACT  References Cited A two-cycle engine oil comprising a polypropylene UNITED STATES PATENTS glycol containing minor controlled amounts of each of 3 281 355 10/1966 Cyphers et al 252/25 x a molybdenum'comaining film-Strength improver and 314001140 9/1968 Rowan et al, 252 32.7 E x a halogenated hydrocarbon detergent-film Strength 3,402,188 9/1968 Wiese 252/32.7 E X mp r- 3,446,735 5/1969 Wiese 252/327 E 10 Cl N D 3,652,411 3/1972 Commichau 252/52 A x 'awmgs TWO-CYCLE ENGINE OIL BACKGROUND The two-cycle engine has never had greater demands put on it, nor has it ever enjoyed more varied uses. The age of leisure time avocations and do-it-yourself pursuits has resulted in the proliferation of enginepowered mini-vehicles, including motorcycles, outboard motorboats, snowmobiles and the like, and what might be termed leisure-time augmenters, such as power mowers, snow blowers, chain saws, and a wide variety of similar tools.
Promotion of these at-times obsolescence-prone and seasonal vehicles, tools and toys is generally fraught with superlatives respecting handling ease, lighter weight, enhanced versatility, etc., which superlatives are ofttimes justified and occasionally braggadocio. There has been a noticeable dearth, however, and with good reason, of substantive promotion language directed to the lubricant and lubricant/fuel mix so essential to the proper functioning, longevity and economy of these pleasure vehicles and worksavers. Of course, the air pollution tenet in the ecologists creed is more frequently than not, and also for good reasons, a no-no in ad copy.
The present invention concerns novel engine oil or lubricant compositions and lubricant/fuel compositions having superior properties. More particularly, the instant discovery is directed not only to significantly improving lubricity but to greater oil and fuel economy, to enhanced power, to increased engine life and smoother running, and to the early demise of pollution anxieties.
Still more specifically, the lubricant composition hereinafter described is unique in that it obviates conventional two-cycle engine lubricant/fuel ratio/of, for example, 50/1, 40/1, 24/1, and permits ratios in the neighborhood of 100/1 with the attendant superior properties and advantages which are above alluded to and which will become more apparent from the further description to follow.
INVENTION According to the present invention a novel two-cycle engine lubricant has been discovered which comprises a major amount of a polypropylene glycol and minor controlled amounts of a molybdenum-containing film strength improver and a halogenated hydrocarbon detergent/film strength improver. Pursuant to a preferred embodiment the composition comprises a major amount of the polypropylene glycol and minor controlled amounts of a sulfurized oxymolybdenum organophosorodithioate, finely divided, colloidal molybdenum disulfide and a halogenated hydrocarbon detergent, such as 1,1,1-trichloroethylene, orthodichlorobenzene, perchlorinated biphenyl, and like detergents which often likewise act as film strength improvers and preferably have solvent and/or diluent properties. More particularly, poly-chlorinated lower alkane or alkene and chlorinated phenyl compounds having the indicated properties are herein contemplated. Preferably, small but effective quantities of a phosphatic improved load carrying (E.P.) additive, such as tricresyl phosphate or a chloro-phosphate, are present in the engine oil composition. v
In addition, and according to a still further preferred embodiment, a small but effective amount of other additives of the more conventional type may be present, including: pour point depressants, such as hydrocarbon wax naphthalene condensates; antioxidants and rust inhibitors, such as p,p'-dioctyldiphenylamine, hindered phenols, salts of diester dithiophosphoric acids (e.g., zinc dialkyl dithiophosphates); other detergents, such as the various basic sulfonates; antifoam agents, such as the liquid silicone polymers, e.g., dimethyl silicone; a glycol ether or like deicer or antifreeze, e.g., butyl Cellosolve; and the like.
Pursuant to the present invention, the polypropylene glycol-based lubricant has a polypropylene glycol concentration in the range of about to about 97.5 percent, by volume, preferably from about 87 to about 96 percent; the film strength improver, e.g., a sulfurized oxymolybdenum organophosphorodithioate, in the concentration of about 0.85 to about 7.0 percent, by volume, preferably from about 1.3 to about 5.3 percent; the finely divided molybdenum disulfide in the concentration range of about 0.15 to about 0.63 percent, by volume, preferably from about 0.2 to about 0.55 percent, the M08 being introduced into the composition as a colloid (MoS /carrier); and the halogenated hydrocarbon detergent/film strength improver, such as perchlorinated biphenyl (PCB) in the concentration of about 1.0 to about 6.6 percent, by volume, preferably from about 1.8 to about 5.6 percent; all of the percentages being based upon the total volume of the polypropylene glycol-based lubricant composition.
The polypropylene glycol contemplated herein preferably has a molecular weight in the range of about 1400 to about 1600, more preferably about 1500 MW, and a Saybolt Universal Viscosity (SUS) at 100F. of about 650 seconds, broadly between about 600 and about 700 seconds. A particularly desirable linear polypropylene glycol is end-capped at one end with a butyl moiety forming a butyl ether (O-C I-I terminal group and the glycol hydroxyl moiety at the other end, the linear polymer itself containing minor yet effective additives for oxidation stability and anti-wear performance. Typical of these is LB650XY40, a so-called UCON Fluid sold by Union Carbide Corporation of New York, New York.
The finely-divided collodial molybdenum disulfide contemplated herein has solids (M08 therein generally less than about one micron in average size, preferably about 0.33 micron, thecarrier being, preferably, the polypropylene glycol hereinabove described and containing, by weight, between about 5 and 15 percent MoS solids, preferably about 10. Generally, from about 3 to about 10 percent, by weight, of a finely divided silica gel, such as CaboSil 85, is used for homogenization, preferably, from about 5 to about 8 percent. In addition to significantly enhancing the engine oil of the present invention in the manner suggested hereinbefore, the colloidal molybdenum disulfide protects against corrosion and wear.
The sulfurized oxymolybdenum organophosphorodithioate compounds contemplated herein, more fully described in US. Pat. Nos. 3,400,140 and 3,495,866, are represented by the formula:
wherein R is an alkyl, cycloalkyl, aryl or alkaryl group having 1 to 30 carbon atoms. If R is an alkyl group, the preferred number of carbon atoms is l to 20 and the especially preferred number of carbon atoms is 3 to 8.
If R is an aryl group, the preferred number of carbon atoms is 6 to 26, i.e., phenyl and alkyl-substituted phenyl groups wherein the alkyl substituent contains 1 to 20 carbon atoms, such as 4 to 9 carbon atoms. The compounds, however, have only one phosphorodithioate radial per molybdenum atom.
Thecompounds may be prepared by dissolving molybdic oxide in a solution of alkali metal hydroxide, magnesium hydroxide, beryllium hydroxide or ammonium hydroxide and by incorporating, subsequently, an approximately equivalent amount, based on hydroxide, of a strong mineral acid, such as sulfuric acid. An organophosphorodithioic acid reactant may be separately prepared by treating a monohydric alcohol or.
phenol with phosphorus pentasulfide in the mole ratio of 4:1. The phosphorodithioic acid reactant is then added to the aforementioned molybdate solution with subsequent finishing operations to form a sulfurized ox ymolybdenum organophosphorodithioate.
It is important herein to heat the mixture of phos phorodithioic acid and molybdate solution at the reflux temperature, e.g., from about 85 to 100C. The reaction time is generally 1 to 5 hours.
It is also important to use 2 mols of phosphorodithioic acid reactant for each mol of molybdate reactant to obtain a maximum yield of the product of this invention having one phosphorodithioate radical per molybdenum atom. No catalyst is required for the reaction. Water is a suitable solvent but other inert solvents may be present, such as a low viscosity aromatic base oil.
The reaction product, i.e., sulfurized oxymolybdenum organophosphorodithioate, may be solid or liquid depending on the organic radical in the phosphorodithioic acid reactant. 1f the molybdenum containing product is a solid, it is recovered by filtration. 1f the molybdenum-containing product is a liquid, it is recovered by filtering out any solid by-products and by distilling to remove the solvent.
A particularly desirable oxidation and corrosion inhibitor, pursuant to the present invention, is purified p,p'-dioctyldiphenylamine. Also contemplated herein, as suggested hereinbefore, are the hindered phenol oxidation and rust inhibitors. These are compounds having one or more phenolic rings with at least one tertiary alkyl (lower) group, usually tertiary butyl, per ring located ortho to a phenolic hydroxyl moiety to sterically hinder its reactivity. Hindered phenols as a class are well known. Illustrative examples thereof include 4,4-thio-bis(6-tertiary butyl-m-cresol); 4,4'-thio-bis (6 tertiary butyl-o-cresol); 2,6 di(tertiary butyl)-p-cresol; 4,4-methy1ene bis(2,6 di-tertiary butyl-phenol); 4,4 bis (2,6-di-tertiary butyl phenol); 2,6 di-tertiary butylalphadimethylamino-p-cresol; 2,6 di-tertiary butyla1pha-methoxyp-cresol; 2,6 -di-tertiary butyl phenol; and mixed tertiary butyl-phenols such as those containing at least 75 percent of 2,6-di-tertiary butyl phenol; 4,4-methylene bis(6 tertiary butyl-o-cresol) 2,2- methylene bis (4-methyl -6-tertiary butyl-phenol); and 2,2-methylene bis(4-methyl-6-tertiary butyl phenol); and 2,2-methylene bis(4-ethyl-6 tertiary butylphenol); and the like.
Other contemplated oxidation and rust inhibitors are the oil-soluble polyvalent metal salts derived from a wide variety of diester dithiophosphoric acids conventionally prepared by reacting a sulfide of phosphorus, such as phosphorous pentasulfide, with an alcohol, phenol or mercaptan. These salts have the structure wherein R to R in the acid esters each represents substituted or unsubstituted aryl (e.g. phenyl), alkyl, aralkyl, cycloalkyl or other monovalent hydrocarbon moieties which contain from about 3 to 20 carbon atoms, preferably, about 3 to 12 carbon atoms, R through R being the same or different. Of the polyvalent metals designated M in the above structure,'zinc is preferred but other metals of 28 to 30 atomic number, such as nickel or copper, are suitable. Alcohols which may be employed in preparing the acid esters include primary and secondary alcohols, such as 4 methylpentanol-2, 2-methylpentanol-1, 2-ethylhexanol, di-isopropyl carbinol, cyclohexanol, butanol-l, isopropanol and octadecanol-l, or mixtures of high and low molecular weight alcohols. The preferred compounds are the zinc dialkyl dithiophosphates wherein the alkyl group contains about 3 to 12 carbon atoms, preferably about 3 to 8 carbon atoms. More specifically, the preferred compounds of this group include, for instance, dihexyl dithiophosphate, diheptyl dithiophosphate, di-Z-methylamyl dithiophosphate, di-2-ethylhexyl dithiophosphate, and the like.
Still other anti-oxidants and anti-corrosion additives suitable for use herein are the oil-soluble alkaline earth metal thiophenates having the structural formula;
5 M s R E ;-R6 (n) wherein M is an alkaline earth metal, R and R each represent a monovalent hydrocarbon moiety containing from about 3 to 20, preferably about 3 to 12 carbon atoms, and n is an integer ofO to 3, R and R being the same or different. Of the alkaline earth metals, calcium is preferred, but other divalent metals belonging to Group II of the Periodic Table, such as beryllium, barium, strontium and magnesium may be used. As in the case of the metal dialkyl dithiophosphates discussed above, the monovalent hydrocabon moieties R and R may be aryl (e.g., phenyl), alkyl, aralkyl, cycloalkyl, and the like, and may be further substituted in the or ganic portion. Preferably, R and R each represent an alkyl group of 3 to 12 carbon atoms, such as n-propyl, isopropyl, butyl, amyl, hexyl, cyclohexyl, octyl, nonyl, decyl, undecyl, dodecyl, and the like. Some examples of the preferred alkaline earth metal thiophenates use ful as antioxidants in the compositions of the present invention are the calcium salts of amyl thiophenate, cyclohexyl thiophenate, 2,4-dioctyl thiophenate, and the like.
Among the anti-wear agents contemplated herein are: zinc diorgano dithiophosphates, including the zinc dialkyl dithiophosphates, which double as antioxidants, the alkyl moiety having two to 12 carbon atoms, such as zinc diheptyl dithiophosphate, antimony dialkyl dithiocarbamates wherein the alkyl moiety has from two (2) to fourteen (14) carbons, e.g., ethyl, butyl, hexyl, octyl, dodecyl, and the like. Generally, for better results, from about 1.10 to about 3.0 percent by volume,
based upon the total volume of the lubricant composition, is therein contemplated.
If desired, as suggested hereinbefore, conventional antifoam agents, E.P. agents, pour point depressants,
and dispersants may be incorporated herein in convenof the engine oil composition. The barium and calcium components are generally introduced as their sulfonates or phenates and they are effective, among other things, in neutralizing sulfur and nitrogen compounds present during combustion.
The basic sulfonates can be prepared by neutralizing aromatic sulfonic acids with a theoretical excess of the hydroxides, chlorides, oxides or other inorganic compounds of the alkaline earth metals so as to obtain a product which contains an amount of alkaline earth metal in excess of that theoretically required to replace he acidic hydrogens of the sulfonic acids. The preferred alkaline earth metal is barium. Generally preferred aromatic sulfonic acids are the oil-soluble mahogany sulfonie acids which can be derived from the treatment of a suitable petroleum oil, such as a liquid petroleum distillate boiling in the range of about 600 to 1000 5, with fuming sulfuric acid or sulfur trioxide,
separating the resulting acid sludge from the acid treated oil and recovering the mahogany acids contained in the acid treated oil. The useful mahogany acids generally have a molecular weight of from about 300 to 500 or more, and although their exact chemical structures may vary, it appears that such acids are composed to a large extent of sulfonated aromatic hydrocarbons, having either one or two aromatic rings per molecule, possibly with one or more long chain alkyl groups containing from about 8 to 30 carbons atoms attached to the ring nuclei.
Likewise, conventional quantities of various pour point depressants may be added to enhance the engine oils of the present invention. These materials are in general prepared by chlorinating paraffin wax and condensing the chlorowax with naphthalene. A preferred product is that prepared by the process described in US. Pat. Nos. 1,963,917 and 1,963,918. Wax alkylated naphthalene products are marketed under trade names, such as Pourex and Paraflow. Other pour point depressors, such as those marketed under the trade name Santapour, can also be used.
The following examples are meant to be illustrative only and not unduly limitative of the invention:
EXAMPLE I The following components are blended as hereinbelow taught:
Components l: by volume Polypropylene glycol LB650XY40 has 8884 1500 MW. 650 SUS at 100F., and includes 2% phenyl-u-naphthylamine and 2% butyl Cellosolve (C.,H,,OC H OH) sulfurized oxymolybdenum di (ptcrtiary- 3.6 butylphenyl) phosphorodithioate solution".
Specific gravity at 25/25C. 1.08
Molybdenum as M00 l0.6%
Viscosity SUS at 100F. 350
Flash Point (COC) F. 360 M05; solids 0.36 PCB (perchlorinated biphenyl) 3.6 [Trade name: Aliclor 1221] 2,6 Di(tertiary hutyU-p-cresol liquid 3.6
Viscosity at 100F., SSU 59 Flash point, F. 285
Four point, F. ---30 Specific gravity, fill/60F. 0.876
Density, lb./gal. at 60F. 7.3
Zinc. wt. percent 0.22
Ash, wt. percent 0.30
Conradson carbon, wt. percent 0.40
[MolyVan L solution sold by R. 'l. Vanderbilt Company. lnc.. New York, N.Y.i Mos solids (0.33 micron average size) introduced into composition as a homogenized (hi shear) blend by weight of the following:
MOS solids Fumed silica (CaboSil 7% LB650XY40 83% 'Parabar 447 oxidation and rust inhibitor sold by Enjay Chemical Company, a Division of Humble Oil & Refining Co.
Procedure: All components but the homogenized blend containing M08 solids are thoroughly mixed together and then the homogenized blend is introduced and admixed under high shearing until the resultant composition is homogenized and has a uniform appearance.
EXAMPLE II The composition of Example I with the exception that, based upon the total volume of the composition, 0.01 percent dimethyl silicone fluid (polymer antifoam agent) is present, the polypropylene glycol concentration being thus reduced proportionately.
EXAMPLE III The composition of Example Il wherein 0.4 percent, by volume, butyl Cellosolve is present as well, likewise proportionately reducing the total concentration of the polypropylene glycol.
EXAMPLE lV Same as Example lll with the exception that the organic moiety of the sulfurized oxymolybdenum compound is di-isopropylphosphorodithioate; also, the sulfurized solution components concentration is 1.8, thus increasing the total concentration of LB650XY40 proportionately.
EXAMPLE V EXAMPLE V1 Same as Example 111 with the exception that the or ganic moiety of the sulfurized oxymolybdenum compound is di(nonylphenyl)phosphorodithioate; also, the
fin ely divided MoS solids concentration is increased to .60, thus reducing the total LB650XY40 proportionately.
EXAMPLE VII concentration of Same as Example III with the exception thatthe organic moiety of the sulfurized oxymolybdenum compound is di(n-propyl)phosphorodithioate; also, the finely divided MoS solids concentration is decreased to 0.23, thus increasing the total concentration of LB650XY4O proportionately.
EXAMPLE VIII EXAMPLE IX Same as Example III with the exception that the organic moiety of the sulfurized oxymolybdenum compound is di(n-amyl)phosphorodithioate; also, the hin- LB65OXY40, and the hindered phenol is substituted with zinc diheptyl dithiophosphate having the following properties:
viscosity SSU at 210F. 6
specific gravity, 60/60F. density, lb./gal. at 60F. zinc, weight percent phosphorus, weight percent sulfur, weight 5. 29 V cente- EXAMPLE XI The product of Example I is blended with conventional outboard motor fuel (gasoline) in theratio of:
Parts Component 1 Product of Example 1 I00 Gasoline EXAMPLE XII The composition of Example I wherein the PCB is substituted with the same concentration of 1, l, ltrichlorothylene.
EXAMPLE XIII The composition of'Example I wherein the: is substituted with another detergent, viz., orthodichlo robenzene, in the concentration of 4.7 percent, by volume, the LBOXY4O concentration being changed proportionately.
EXAMPLE XIV Same as Example I, with the exception that a pour point depressant (Paraflow 149 sold by Enjay Chemical Company, a Division of Humble Oil & Refining Co.) is also present in the, concentration of 0.05%, by volume, and the LB650XY40 is reduced proportionately. *Hydrocarbon wax-naphthalene condensate of the Friedel- Crafts type.
Viscosity at 210F., SSU 308 Flash point, F. 450 Pour point, F. +55 Conradson carbon, wt. percent 1.9 Density, lb./gal. at 60F.
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of this invention as described hereinabove and as defined in the appended claims.
What is claimed is:
I. A two-cycle engine lubricant composition which consists essentially of a polypropylene glycol concentration in the range of about to about 97.5%, by volume, a sulfurized oxymolybdenum hydrocarbylphosphorodithioate in the concentration of about 0.85 to about 7.0 percent, by volume, a finely-divided molybdenum disulfide in the concentration of about 0.15 to about 0.63 percent, by volume, and a halogenated hydrocarbon detergent film strength improver in the con-. centration of about 1.0 to about 6.6 percent, by volume, all of the percentages being based upon the total volume of the polypropylene glycol-based lubricant composition.
2. The composition of claim 1 wherein the polypropylene glycol concentration is in the range of about 87 to about 96 percent,by volume, the sulfurized oxymolybdenum hydrocarbylphosphorodithioate in the concentration of about 1.3 to about 5.3 percent, by volume, the finely-divided molybdenum disulfide in the concentration range of about 0.2 to about 0.55 percent, by volume, and the halogenated hydrocarbon detergent film strength improver in the concentration of about 1.8 to about 5.6 percent, by volume.
3. The composition of claim 2 wherein the polypropylene glycol has a molecular weight in the range of about 1400 to about 1600 and a Saybolt Universal Viscosity (SUS) at 100F of between about 600 seconds and about 700 seconds.
4. The composition of claim 3 wherein the polypropylene glycol is linear and end-capped at one end with a butyl moiety forming a butyl ether (O-C H terminal group, the other end having a glycol hydroxyl moiety.
5. The composition of claim 4- wherein the molybdenum disulfide is present as finely-divided colloidal molybdenum disulfide having MoS generally less than about 1 micron in average size.
6. The composition of claim 5 wherein the colloidal molybdenum disulfide contains the finely-divided M08 solids in the concentration of between about 5 and 8. The composition of claim 7 wherein the hindered phenol is 2,6-di(tertiary butyl)-p-cresol.
9. A two-cycle engine gasoline fuel containing a minor amount of the lubricant composition of claim 1.
10. The two-cycle engine fuel composition of claim 9 wherein the gasoline to lubricant composition is to l, volume/volume.