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
  • C10M7/00—Solid or semi-solid compositions essentially based on lubricating components other than mineral lubricating oils or fatty oils and their use as lubricants; Use as lubricants of single solid or semi-solid substances
• • 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
  • C10M171/00—Lubricating compositions characterised by purely physical criteria, e.g. containing as base-material, thickener or additive, ingredients which are characterised exclusively by their numerically specified physical properties, i.e. containing ingredients which are physically well-defined but for which the chemical nature is either unspecified or only very vaguely indicated
  • C10M171/002—Traction fluids

Definitions

• This invention relates to functional fluids particularly adapted for use in tractive drives and more specifically to greases having high coefl'lcients of traction and comprising mixtures of tractive fluids and organic or inorganic thickening agents.
• a tractive drive is a device in which torque is transmitted from an input element to an output element through nominal point or line contact typically with a rolling action by virtue of the traction between the contacting elements. While tractive elements are commonly spoken of as being in contact, it is generally accepted that a fluid film is present therebetween. Almost all tractive drives require fluids to remove heat, to prevent wear at the contact surfaces and to lubricate bearings and other moving parts associated with the drive. Thus, instead of metal to metal rolling contact there is a film of fluid introduced into the contact zone and interposed between the metal elements. The nature of this fluid determines to a large extent the limits in performance and the capacity of the drive.
• tractive drives are designed to operate with a tractive fluid which preferably has a coefficient of traction above about 0.06, a viscosity in the range of about 420,000 cs. over a temperature range of 100 F. to 0 F. and good thermal and oxidative stabillty.
• the fluid should also be noncorrosive to common materials of construction and have good load-bearing and low wear-rate properties.
• the novel composit ons of the present invention are prepared by thickening tractive fluids having a coefficient of traction of at least about 0.06 with organic or inorganic thickeners to yield a grease having a coeflicient of traction in excess of 0.10 as measured at 100 F. and 200,000 p.S.i. maximum Hertz stress.
• the tractive fluid is preferably a compound containing from about 12 to carbon atoms, up to 8 of which can be replaced by oxygen, nitrogen, phosphorus, or silicon, and having a structure which includes either a cyclic radical having at least one saturated carbon-containing ring of at least 6 member atoms or an acyclic radical in which there are at least 3 quaternary carbon atoms.
• the thickeners are preferably colloidal silica or polyurea.
• the greases comprise a major amount of a tractive fluid and a minor amount, generally in the range of from about 5 to 25 percent by weight of a thickening agent.
• compositions of the present invention comprise tractive fluids thickened to a grease consistency by the use of organic or inorganic thickeners.
• Typical tractive fluids useful in the present invention include those described at lengths in US. Pat. 3,411,369 and US. Pat. 3,440,894. These fluids are defined in terms of certain structural units or elements present within their molecules which render the fluids particularly suitable for use in tractive devices.
• suitable fluids are those organic compounds (1) having from about 12 to about 70 carbon atoms, up
• Tractants encompassed within the above definition are enumerated in US. Pat. 3,440,894 from column 7 line 26 to column 10 line 57, and this disclosure is specifically incorporated herein by reference.
• tractive fluids encompassed within the above definition are cyclododecane, bicyclohexyl, 1,2-tercyclohexyl, dicyclohexylmethane, 2, 3 dicyclohexyl-Z,S-dimethylbutane, 2,4-dicycloheXyl-2- methyl pentane, and mixtures thereof.
• a nonexclusive list of other suitable tractive compositions includes for example isodecylcyclohexane, isopentadecylcyclohexane, cyclododecane, bicyclohexyl, 4-(1- methylethyl) bicyclohexyl, 4,4-bis( l-methylethyl bicyclohexyl, X-isohexyl 4-isopropylbicyclohexyl, x-cyclopentylbicyclohexyl, dicyclohexylmethane, (x-ethylcyclohexyl) cyclohexylmethane, [x-cyclohexyl( l-methylethyl) ]cyclohexylmethane, bis(2,4,6-trimethylcyclohexyl)methane, 1, 1 dicyclohexylethane, 1,1,3 tricyclohexylpropane, trimethylo
• tercyclohexyl 1,2-isopropyltercyclohexyl, 1,3-isopropyltercyclohexyl, bis( 1,3 cyclohexyloxy)-cyclohexane, 1,xbis-(methylcyclohexyl)-cyclohexane, dicyclohexyl cyclohexane 1,3-dicarboxylate, x,x'-quatercyclohexyl, 6-ethyl- 2,2,4,4,11,11,13,13 octamethyltetradecane and 2,2,4,4,13, 13,15,15 octamethylhexadecane, tricyclohexylmethane, N-cyclohexylpiperidine, neopentyl glycol dineotridecanoate, bicyclooctyl, bicyclododecyl, cyclohexyl cyclododecane, cycloheptyl
• suitable and useful tractive fluids are those organic compounds defined in U.S. Pat. 3,411,369 which have a coefiicient of traction of at least about 0.06, and which have from 2 to 9 fused, saturated, carboncontaining rings and from about 9 to about 60 carbon atoms, up to 8 of which can be replaced by atoms other than carbon atoms such as oxygen, nitrogen, phosphorus and silicon.
• a comprehensive disclosure of suitable fused ring compounds is given in U.S. Pat. 3,411,369 from column 7 line 4 to column 9 line 18, which disclosure is specifically incorporated herein by reference.
• a nonexclusive list of some particularly preferred compounds encompassed by this reference include for example cis-Decalin, cisand trans-Decalin, 2,3-dimethylDecalin, isopropylDecalin, t-butylDecalin, perhydrofluorene, perhydrophenanthrene, perhydromethylcyclopentadiene (trimer), perhydrofiuoranthene, 1 cyclohexyl-1,3,3-trimethylhydrindane, x-hexylperhydrofiuoranthene, x-cyclohexylperhydrofluoranthene, poly(ethyl 1 methyl)perhydrofluoranthene, x-isopropylperhydrofiuoranthene, perhydrofiuorene x cyclohexyl, perhydrofiuorene-x-isododecyl, 1 cyclohexylDecalin, 2 (cyclohexy
• the useful fused ring compounds can be either substituted or unsubstituted, and the substituents can be alkyl or alicyclic hydrocarbons or heterocyclic carbon-containing ring structures.
• the alkyl substituents can be either straight chain or branched compounds and can contain from 1 to 18 or more carbon atoms.
• the thickening agents can be any of a number of materials commonly used to thicken mineral oils to lubricating viscosity, including both organic and inorganic compositions such as metallic soaps, synthetic polymers, organosiloxanes, clays, bentonite, and colloidal silica.
• the metallic soaps most commonly employed as thickeners for mineral oils are the fatty acid soaps of lithium, sodium, calcium and aluminum, and to a lesser extent of potassium, magnesium, barium, and lead.
• the usual fatty acids used to form such gelling agents are those having from 8 to 32 carbon atoms and may be naphthenic acids, rosin acids, abietic acids, petroleum sulphonic acids or seturated, unsaturated or polar-substituted fatty acids.
• Saturated fatty acids are, for example, capric, lauric, myristic, palmitic and stearic, and the unsaturated fatty acids are, for example, arachidic, behenic, oleic, linoleic, linolenic, cotton seed fatty acids, palm oil fatty acids, soya bean fatty acids, castor oil fatty acids, tallow fatty acids and tall oil fatty acids.
• the unsaturated fatty acids may be partially or completely hydrogenated and/ or hydroxylated and/or epoxidized or otherwise oxidized.
• Other fatty acids include those produced by oxidation of petroleum oils, petroleum waxes and naturally occurring waxes such as montan wax.
• the soaps may be of any of the known types, such as those made from the oxides or hydroxides of one or several metals from Groups I, II, III, IV and VIII of Mendeleelfs periodic table.
• a water-soluble soap such as the sodium, potassium or ammonium soap is usually first prepared and the insoluble metal soap of the organic acid is then precipitated by adding a water-soluble salt of the precipitating metal.
• Sodium, potassium, lithium, calcium, magnesium, barium, strontium, cadmium, zinc, aluminum, lead, cobalt and tin soaps are effectively used to thicken tractive grease compositions of this invention.
• Examples of preferred soaps for use either alone or in admixture are: sodium stearate, sodium hydroxystearate, sodium oleate, potassium stearate, potassium rosinate, potassium oleate, lithium stearate, lithium hydroxystearate, lithium rincinoleate, calcium stearate, calcium hydroxystearate, barium stearate, barium hydroxystearate, strontium stearate, cadmium oleate, cadmium stearate, cadmium rosinate, zinc steal-ate, aluminum naphthenates, aluminum stearate, aluminum hydrostearate, lead naphthenates, lead stearate, lead hydroxystearate, magnesium stearate, magnesium oleate, magnesium rosinate, magnesium naphthenate, magnesium hydroxystearate, tin stearates, and tin naphthenates. Soaps of amines such as stearyl amine or triethanolamine may also be used
• Organic thickeners useful in preparing the tractive greases of this invention include, for example, p-polyphenyl, biphenylene diisocy-anates, monophenylenediisocyanates, arylureas, polyarylureas, 1,3,5-triazene compounds including diamino-alkyl-triazene and diaminoaryl triazene, bis(triphenylsilyl) perfluorodicarboxylic acid esters, alkyl silox-anes, and aryl si'loxanes such as phenylsiloxane.
• Inorganic thickeners include materials such as clay, colloidal silica, silica aeroge'l, alumina, graphite, mica, talc and diatomaceous earth.
• a Widfi latitude in thickener composition is permitted since the selection of thickeners is not critical to the present invention provided the thickener has no adverse effect upon the tractive coefficient.
• Particularly preferred organic thickeners which give excellent results to the tractive base stock fluids are the polyureas, and a particularly preferred inorganic thickener is finely divided amorphous silica. Each of these agents provides a grease having excellent physical properties and performance characteristics.
• Amorphous silica is conventionally prepared by the high temperature vapor phase hydrolysis of silicon tetrachloride. It may also be prepared by the high temperature vapor phase thermal decomposition of silicon compounds such as silicon esters, or by the high temperature vapor phase hydrolysis of silicon compounds such as silicon esters or silanes with super heated steam. Amorphous silica prepared according to any of these methods is extremely fine with particles ranging in size from 0.015 to 0.020 microns, and is a preferred thickener for tractive grease formulations.
• arylurea and polyarylurea thickeners are readily prepared by reacting arylisocyanates and aryl amines according to conventional procedures.
• suitable aryl isocyanates which can be used in the preparation of these thickeners include the following:
• the tractive grease compositions of this invention are prepared by dispersing a selected thickener in a tractive fluid by suitable mechanical means such as rapid stirring or milling.
• the tractive fluid generally comprises a major proportion, i.e'. in excess of about 50% by weight, of the grease composition, while the thickener preferably comprises from about 5% to 25% by weight of the grease, although greater amounts of thickener up to about 50% by weight may be used to advantage in some formulations.
• the coeflicient of traction of the finished grease is determined on a rolling disc test machine which comprises two hardened steel rollers which may be loaded difference in velocities of the two roller surfaces, and is essentially independent of load and the mean velocity of the roller surfaces.
• the rates of sliding that are of significance in the transmission of power usually range from approximately 1 in./sec. up to in./sec.
• the best criterion of the tractive capacity of a grease is the value of the coeflicient of traction over this range of sliding.
• the tractive coefiicients reported herein were obtained at an operating temperature of 100 F. and a Hertz stress of 200,000 p.s.i.
• the coeflicients of traction reported are the average coefiicients over a range of from 1 to 8 percent slip at sliding speeds of from 1 in./sec. to 50 in./sec. and a mean surface velocity of from 330 ft./min. to 4,640 ft./min.
• Grease AA tractive fluid comprising a base stock of 2,4-dicyclohexyl-Z-methyl pentane (hereinafter designated as TF-l) thickened with 16 percent by weight polyurea.
• Grease BTF1 thickened with 9 percent by weight of amorphous silica.
• Grease C--A tractive fluid comprising a base stock of equal parts' 2,4-dicyclohexyl-Z-methyl pentane and dicylohexyl-1,2-cyclohexane dicarboxylate (hereinafter designated as TF-2) thickened with 17 percent by weight of polyurea.
• Grease DTF2 thickened with 9 percent by weight amorphous silica.
• the two test rollers are 1% chromium ball bearings steel hardened to -62 to 65 Rockwell C. They have a diameter of 6 inches and are crowned to a radius of 3 inches to give a spherical contact zone, and are carried at the ends of shafts running in heavy duty ball and roller bearings. Roller surface temperature is indicated by thermocouple which bears lightly against the rim of the lower roller.
• the coefficient of traction is a function of the sliding velocity, e.g., the
• the tractive greases have an average coefficient of traction of greater than about 0.10 as determined at a sliding velocity of 10 in./ sec. under the conditions of the test described above.
• the tractive greases of this invention add a new dimension to tractive compositions and provide means for obtaining exceptionally high performance from tractive drives where power transmission is dependent upon the coeflicient of traction of the tractive fluid.
• the exceptionally high coefficients of traction provided by these greases have not heretofore been known, and are not now available from any other source.
• the discovery that such high coefficients of traction could be provided by the compositions of the instant invention represents a significant advance in the state of the art relating to power transmission, and allows greater power to be derived from smaller units than was heretofore possible.
• the use of tractive grease eliminates the need for fluid seals thereby simplifying design of the tractive units and reducing construction and maintenance costs.
• the grease compositions of the instant invention can contain any of a variety of additives useful in compounding greases such as for example, antioxidants, corrosion inhibitors, V.I. improvers or other viscosity control agents, EP lubricating agents, and the like. Compositions including such additives are accordingly included within the scope of the present invention as defined in the claims attached hereto.
• a grease composition comprising (A) a grease thickening amount of a thickener, and
• a tractive fluid consisting essentially of a compound containing from about 12 to 70 carbon atoms, said compound having in its structure a radical selected from the group consisting of cyclic radicals having at least one saturated carbon-containing ring of at least 6 atoms and acyclic radicals of at least 3 quaternary carbon atoms, and said tractive fluid having a coeflicient of traction of at least about 0.06.
• a grease composition comprising (A) a greasethickening amount of a thickener, and
• (B) a major amount of a tractive fluid consisting esing of clay, silica, alumina, graphite, mica, talc, and diatomaceous earth.
• composition of Claim 3 wherein the thickener is an organic material selected from the group consisting of metallic soaps, synthetic polyureas, and organosiloxanes.
• a composition of Claim 1 wherein the tractive fluid is selected from the group consisting of dicyclohexyl, alkyldicyclohexyl, tercyclohexyl, alkyltercyclohexyl, quartercyclohexyl, quinquicyclohexyl, 2,3 dicyclohexyh 2,3-dimei-hylbutane, 2,4-dicyclohexyl-2-methyl pentane, and mixtures thereof.
• composition of Claim-2 wherein the tractive fluid is selected from the group consisting of Decalin, alkyl- Decalin, cyclohexylDecalin, alkylcyclohexyDecalin, 1- cyclohexyl1,3,3,-trimethylhydrindane, and mixtures thereof.
• a composition of Claim 1 wherein the tractive fluid is 2,4-dicyclohexyl-Z-methyl pentane and the thickener is polyurea.
• a composition of Claim 1 wherein the tractive fluid is 2,4-dicyclohexyl-2-methyl pentane and the thickener is silica.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Lubricants (AREA)

Priority Applications (10)

Applications Claiming Priority (1)

Publications (1)

Family

ID=22503191

Family Applications (1)

Country Status (8)

Cited By (10)

Family Cites Families (2)

• 1971
  • 1971-05-13 US US00143237A patent/US3835050A/en not_active Expired - Lifetime
• 1972
  • 1972-05-10 FR FR7216776A patent/FR2137753B1/fr not_active Expired
  • 1972-05-12 JP JP47047147A patent/JPS5812319B1/ja active Granted
  • 1972-05-12 DE DE19722223307 patent/DE2223307A1/de active Pending
  • 1972-05-12 SE SE7206302A patent/SE382822B/xx unknown
  • 1972-05-12 GB GB2235772A patent/GB1394441A/en not_active Expired
  • 1972-05-12 GB GB4065774A patent/GB1394443A/en not_active Expired
  • 1972-05-12 GB GB4065674A patent/GB1394442A/en not_active Expired
  • 1972-05-12 CA CA142,206A patent/CA1000259A/en not_active Expired
  • 1972-05-12 IT IT24258/72A patent/IT955450B/it active

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