Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M1/00—Liquid compositions essentially based on mineral lubricating oils or fatty oils; Their use as lubricants
  • C10M1/08—Liquid compositions essentially based on mineral lubricating oils or fatty oils; Their use as lubricants with additives
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
  • C10M2201/06—Metal compounds
  • C10M2201/065—Sulfides; Selenides; Tellurides
  • C10M2201/066—Molybdenum sulfide
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2217/00—Organic macromolecular compounds containing nitrogen as ingredients in lubricant compositions
  • C10M2217/02—Macromolecular compounds obtained from nitrogen containing monomers by reactions only involving carbon-to-carbon unsaturated bonds
  • C10M2217/028—Macromolecular compounds obtained from nitrogen containing monomers by reactions only involving carbon-to-carbon unsaturated bonds containing monomers having an unsaturated radical bound to a nitrogen-containing hetero ring
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2217/00—Organic macromolecular compounds containing nitrogen as ingredients in lubricant compositions
  • C10M2217/06—Macromolecular compounds obtained by functionalisation op polymers with a nitrogen containing compound
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2070/00—Specific manufacturing methods for lubricant compositions
  • C10N2070/02—Concentrating of additives

Definitions

• a liquid lubricant composition comprising a homogeneous stable suspension of finely-particulated molybdenum disulfide in a base oil incorporating a dispersant comprising a specific copolymer of a methacrylate ester and N-vinyl pyrrolidone which is present in controlled proportions relative to the quantity of molybdenum disulfide present.
• the invention also encompasses the process of forming such homogeneous stable suspensions, as well as concentrates thereof.
• the plate-like laminar form of particles of various metal sulfides renders such compounds useful as lubricants and agents for enhancing the lubrication characteristics of other base lubricants.
• molybdenum disulfide or molybdenite is best known and most extensively used for this purpose. Particularly successful results have been obtained by employing finely-divided molybdenum disulfide particles in various grease and base oil compositions so as to effect an enhancement in the lubricating properties thereof.
• a continuing problem associated with such liquid lubricant compositions has been the tendency of the suspended molybdenum disulfide particles to settle out during quiescent storage over relatively short time periods. Attempts to increase the homogeneity and longevity of such suspensions have not met with significant success and, accordingly, the lack of stability of such liquid lubricant compositions and/or the high cost of their preparation, has detracted from a more widespread commercial use thereof.
• the benefits of the present invention are based on the discovery that by employing a specific dispersant of a controlled chemical composition in controlled proportions relative to the quantity of molybdenum disulfide present, and by employing the molybdenum disulfide in a controlled particle size, stable suspensions of such molybdenum disulfide particles can be readily and economically attained, enabling its adaptation for compounding conventional motor oils to achieve improved engine performance, particularly under heavy-duty operations.
• the present invention in its composition aspects, is based on the discovery that by employing a dispersant composed of a copolymer of a methacrylate ester and N-vinyl pyrrolidone of an average molecular weight ranging from about 350,000 to about 600,000 in an amount of about 0.2 up to about 0.8 part per weight for each part by weight of molybdenum disulfide particles present, a substantially homogeneous and stable suspension is provided having a longevity of upwards of six months even during quiescent storage.
• the lubricant suspension can be prepared in the form of a concentrate containing from about 5% up to about 30% by weight of molybdenum disulfide particles which can thereafter be conveniently added and/or blended with a neat motor oil so as to provide a final operating concentration usually ranging from about up to about 5% by Weight molybdenum disulfide.
• the molybdenum disulfide particles are reduced to an appropriate particle size or less than about 3 microns employing a fluid energy reduction mill, whereafter the particles are dispersed in a suitable base oil employing a Cowles-type mixer in the presence of the dispersing agent, forming a homogeneous suspension of the particles in the base oil.
• the improved stability of the liquid lubricants incorporating molybdenum disulfide particles in accordance with the present invention is based on the use of a controlled amount of a particlular methacrylate ester/N-vinyl pyrrolidone copolymer in relation to the amount of molybdenum disulfide particles present.
• the copolymer can be represented by the following structural formula:
• the R constituent of the methacrylate ester is selected so as to average at least about C to provide optimum dispersibility of the molybdenum disulfide particles and solubility of the dispersant in most organic lubricating compositions.
• dispersant is selected so as to have an average molecular weight ranging from about 350,000 up to about 600,000 and preferably about 500,000.
• the ratio of mm may range from about 1:5 to about 1:15 and is preferably controlled at about 1:12.
• the quantity of the dispersant employed is dictated by the quantity of molybdenum disulfide particles present.
• the dispersant is used in an amount of about 0.2 to about 0.8 parts per part molybdenum disulfide present and preferably from about 0.35 to about 0.45 parts dispersant per part molybdenum disulfide.
• the concentration of the molybdenum disulfide particles generally can range from about 0.25% up to about 30% based on the total weight of the liquid lubricating composition.
• concentrates of molybdenum disulfide suspensions in a base oil incorporating the dispersant are formed so as to contain from about 5% to about 30%, and preferably from about to about 20%, molybdenum disulfide.
• Such concentrates can conveniently be added to the motor oil present in a crankcase so as to provide an actual operating range of about 0.25% to about 5% and preferably a diluted concentration of about 0.5% to about 3% molybdenum disulfide.
• molybdenum disulfide particles present in the motor oil in an internal combustion engine crankcase can be varied within the aforementioned ranges depending uponthe specific conditions under which the engine is operated, as well as specific engine design characteristics as they relate to frictional loading imposed upon engine components. In most instances, molybdenum disulfide concentrations of about 0.5 to about 3% have been found to provide satisfactory performance and to provide significant improvements under high speed and/ or heavyduty operating conditions when incorporated in conventional motor oils used in present-day internal combustion engines.
• the molybdenum disulfide particles suspended in the base oil are controlled so as to be of a particle size less than about 3 microns and preferably of an average particle size less than about one micron.
• it is perhaps more accurate to express particle size from the standpoint of total surface area of the powder which, for the purposes of the present invention, is at least about 10 square meters per gram and preferably from about square meters up to about square meters per gram.
• the base oil to which the molybdenum disulfide particles and dispersant are added for forming either a concentrate or the final diluted motor oil may comprise any known synthetic or mineral base oil suitable for use as a motor oil in internal combustion engines. Generally, such base oils preferably have a viscosity ranging from an SAE 5W up to about 50. Such base oils may additionally contain other well known lubricant additives which are compatible with the dispersant and molybdenum disulfide particles present and which do not otherwise adversely affect the stability of the molybdenum disulfide suspension.
• the present invention encompasses the comminution of the molybdenum disulfide to a particle size within the aforementioned range employing an air micronizer in accordance with the technique as described in U.S. Pat. No. 3,082,065, granted Mar. 19, 1963, which is assigned to the same assignee as the present invention.
• a powdered mass of molybdenite concentrate usually derived from the flotation extraction operation of molybdenite ore, which contains from about 0.25% to 8% of the flotation oils, is charged directly into a fluid energy reduction mill wherein the particles become entrained in a high velocity gas, such as air.
• a high velocity gas such as air.
• the turbulence present in the cyclonic fiow of gas causes mutual impact to occur between the entrained particles, effecting a pulverization thereof to a reduced particle size.
• the centrifugal action present in the mill By virtue of the centrifugal action present in the mill, the heavier or larger particles are retained within the mill for further reduction, while the finer particles are entrained in the exhaust gas and are extracted from the mill.
• a controlled extraction and corresponding reduction in the oil and moisture content of the comminuted molybdenite can be effected simultaneously with the pulverization of the molybdenite to a desired particle size.
• the resultant molybdenum disulfide powder derived from the fluid energy reduction mill, or as many otherwise be provided, is admixed with a suitable base oil in the desired concentration range and is suspended by subjecting the mixture to high shear agitation, such as encountered in a Cowles-type mixer.
• the base oil incorporating usually from about 5% up to about 30% molybdenum disulfide particles is subjected to a high shear agitation by means of a relatively flat disk supported on and rotated at high speed by means of a shaft so as to effect a separation of agglomerates of the individual molybdenum disulfide particles into single particles and a substantially uniform distribution thereof throughout the base oil.
• the resultant blend or slurry is thereafter subjected to a particle size separation, which preferably is performed in a disk-type centrifuge such as Sharples centrifuge, to effect the removal of any extraneous large-size molybdenum disulfide particles or agglomerates present.
• a particle size separation which preferably is performed in a disk-type centrifuge such as Sharples centrifuge, to effect the removal of any extraneous large-size molybdenum disulfide particles or agglomerates present.
• a disk-type centrifuge such as Sharples centrifuge
• an appropriate amount of dispersant is added to the centrifuged blend, which is again subjected to a high shear mixing in a Cowles-type mixer.
• the dispersant can conveniently be introduced in the form of a concentrate in a neutral oil, which may conveniently range from about 30% up to a 50% concentration in a light oil having a viscosity of about SAE 5.
• the composite blend containing the base oil, the molybdenum disulfide particles and the dispersant, along with other compatible additives, is mixed for an additional period, usually of about one hour. While mixing times in excess of about one hour can be satisfactorily employed, it has been found that no appreciable improvement in the stability of the resultant motor oil suspension is achieved and, therefore, such longer mixing periods constitute an uneconomical usage of equipment.
• the resultant blend which is in the form of a concentrate, is removed from the mixing apparatus and can thereafter be placed in suitable containers until eventual use, at which time it is added to the crankcase of an engine.
• Concentrates prepared in accordance with the aforementioned process containing between about 10% to about 20% molybdenum disulfide particles have been observed to be of excellent stability when placed in quiescent storage for periods of time ranging from about 6 to about 12 months.
• Example I One hundred pounds of a technical grade molybdenum disulfide powder having an average particle size of about 3 to about 5 microns was placed in a fluid energy reduction mill in accordance with the technique as previously described with reference to U.S. Pat. No. 3,082,065. Prior to the addition of the molybdenite powder to the mill, 0.25% of a neutral mineral oil was admixed with the powder to minimize surface oxidation thereof during the milling operation. The milling was performed in a two-stage operation resulting in the recovery of substantially all of the molybdenite powder which was of an average particle size of less than about 0.5 microns and surface area greater than about 15 square meters per gram.
• the resultant molybdenum disulfide powder was admixed with 300 pounds of a typical SAE-20W motor oil in a Cowles-type mixer forming a slurry containing a nominal 25% molybdenum disulfide. After blending for a period of about one hour, the resultant slurry was pumped through a disk-type Sharples centrifuge whereby substantially all of the particles above about 2 microns were extracted in the form of a sludge containing 50 pounds oil and 20 pounds molybdenite and. the resultant filtered slurry was again returned to the Cowles mixer.
• the resultant concentrate was tested for stability by placing a portion thereof in quiescent storage. After a period of two months, the concentrate was found to contain in excess of about 96% of the original molybdenum disulfide particles still in suspension. Another portion of the concentrate was added to a Havoline 20-20W motor oil to provide an operating concentration of about 3% molybdenum disulfide. A second portion was similarly diluted with the same motor oil to provide a 1% molybdenum disulfide operating concentration.
• the resulting motor oil was tested under engine dynamometer conditions to measure variations in brake horsepower and brake specific fuel consumption in an Oldsmobile engine over an r.p.m. range of 2100 to 4800 under wide-open throttle conditions.
• the motor oil containing 1% molybdenum disulfide evidenced a 3.6% increase in horsepower over the entire engine speed range with an average increase of about 3.4% over the r.p.m. range of 3300 to 4800.
• a 5.6% decrease in fuel consumption was noted over the entire speed range, while a 5.5% average decrease in fuel consumption was obtained over the 3300 to 4800 r.p.m. range.
• Example II The concentrate prepared in accordance with Example I was admixed with a Super Shell 10W-30 motor oil to similarly provide concentrations of the molybdenum disulfide constituent at levels of 1% and 3%, respectively. Dynamometer tests simulating actual road conditions confirmed the same results obtained in the tests conducted in accordance with Example I.
• a lubricant composition consisting essentially of a base oil containingfrom about 0.25% to about 30% molybdenum disulfide particles less than about 3 microns in size suspended therein and a dispersant present in an amount of from about 0.2 to about 0.8 parts dispersant per part molybdenum disulfide present, said dispersant consisting of a copolymer of a methacrylate ester and N-vinyl pyrrolidone of an average molecular weight of about 350,000 to about 600,000 corresponding to the formula:
• Ratio of m:n 1:5 to 1:15.
• the lubricant composition as defined in claim 1, comprising a crankcase motor oil in which said molybdenum disulfide particles are present in an amount of about 0.5% to about 3%.

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Lubricants (AREA)
• Compositions Of Macromolecular Compounds (AREA)

Priority Applications (7)

Applications Claiming Priority (1)

Publications (1)

Family

ID=22169463

Family Applications (1)

Country Status (7)

Cited By (10)

Families Citing this family (1)

• 1970
  • 1970-10-19 US US00082166A patent/US3842009A/en not_active Expired - Lifetime
• 1971
  • 1971-07-29 CA CA119,423A patent/CA962659A/en not_active Expired
  • 1971-09-13 DE DE19712145640 patent/DE2145640B2/de active Pending
  • 1971-09-20 GB GB4378071A patent/GB1317675A/en not_active Expired
  • 1971-09-23 FR FR7134270A patent/FR2112315B1/fr not_active Expired
  • 1971-10-05 NL NL717113660A patent/NL145892B/xx unknown
  • 1971-10-11 JP JP46079542A patent/JPS5035082B1/ja active Pending

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