MXPA96005490A - Lubricated grease - Google Patents

Abstract

A lubricating grease having superior penetration, drip point and cut stability properties, comprising a base oil, an additive package, a thickener containing urea and a soap thickener is provided.

Description

LUBRICANT GREASE FIELD OF THE INVENTION This invention relates to lubricants and fats possessing superior penetration, drip point and shear stability properties. More particularly, this invention relates to a lubricating grease comprising thickeners containing urea and lithium soap.

BACKGROUND OF THE INVENTION Previously, lubricating greases were thickened by salts of metal soaps of fatty acids of which the most commonly used metals were sodium, calcium, aluminum and lithium. Fatty acids included several vegetable and animal fatty acids as well as - '"" "" those derived from oil sources. More recently, the preferred fatty acids have been hydroxylated stearic acids and, more preferably, 12-hydroxystearic acid. Salts of metal soaps of fatty acids for lubricating greases were generally supplied by reacting the hydroxide, the oxide and the metal carbonate or other basic metal compound with fatty acid to form the corresponding fatty acid soap.

P1361-9thMX, 5s to thickener formation reaction normally occurred directly in the base oil, which was to be thickened. Depending on the thickener to be formed, water was often used as a solvent or reaction stabilizer. If a fatty acid derivative such as an ester was used as the source of fatty acid, the water was added to hydrolyze the derivative and to release the fatty acid which could then react with the reagent. basic to form the fatty acid soap. If water was not required in the final product to stabilize the thickener system, the water was generally removed by heating the grease above 212 ° F (100 ° C). Fatty acid thickeners such as those described above are generally referred to as simple soap thickeners. Depending on the base - The metal used, the fats thickened by these simple soaps have drip points (ASTM D-2265) of about 200 ° F (93.33 ° C) to about 380 ° F (193.33 ° C). The drip rate of these thickened products with simple soap defines their highest operating temperature by the following qualitative ratio: the highest temperature of satisfactory performance is 100 ° F (37.78 ° C) lower than the drip point. a fat thickened with soap P1361-96MX "^ lithium having a drip point close to 400 ° F (204.44 ° C), the maximum operating temperature of that grease was only about 300 ° F (148.89 ° C). severity of lubricating grease applications, the need for thickening systems that have higher drip points became evident, this need resulted in the development of complex soap thickeners.The most commonly used complex soap thickeners are complex of calcium, lithium complex and aluminum complex Lithium complex and aluminum complex fats generally have poor thermal stability or oxidation at sustained elevated temperatures such as 350 ° F (176.67 ° C) and above. temperatures, the fat quickly degrades to a hard lacquer material that is devoid of lubricating properties. - • * "" hard lacquer deposit is generally considered to be the result of the catastrophic oxidation of grease and is generally believed to be promoted by lithium and aluminum complex thickeners. The use of antioxidant additives can slow the oxidation of fat but can not avoid it. As such, sustained elevated temperatures adversely affect the performance of lithium complex and aluminum complex greases despite their generally drip point properties.

P1361-96MX Superior. Thickened fats with calcium complex can also harden severely at sustained high temperatures, although, usually not until the hard lacquer condition exhibited by the lithium and aluminum complex greases. However, calcium complex fats are vulnerable in other areas. For example, at temperatures as low as 75 ° F (23.89 ° C) and in the presence of air, calcium complex fats generally begin to harden. Hardening begins at the grease / air interface and slowly expands with time into the fat mass.

This phenomenon is well known in the art and is commonly referred to as surface / aging hardening. This hardening feature of the • '* "" fats thickened with complex soap presents numerous problems for many commercial applications. For example, in bearing applications, where the bearing is only moving part of the time but experiences high temperatures during these times, the effects of hardening will generally reduce the life of the bearing. In applications where friction or oscillatory movements are experienced, the long-term hardening of the grease can cause P1361-96MX "a catastrophic failure due to lack of lubrication of functional lubricant Another problem commonly experienced by complex lithium and calcium fats is that of reduced thickening power.Simple lithium soap fats with a degree of NLGI consistency No.2 can normally have a lithium soap content of 6 percent to - percent based on the weight of the grease, however, - "for thickened fats with lithium complex of equivalent consistency, almost double the amount of thickeners, from 12 percent to 14 percent, based on the weight of the fat. Thickened fats with calcium complex show similar behavior. For example, a calcium complex fat with NLGI No. 2 grade, can usually require soap levels of 16 percent to 18 percent, based on the weight of the fat, in '"*" "comparison with approximately 8 percent for the fats thickened with simple calcium soap of equal consistency In addition to the higher cost associated with the thickener component compared to the base oil of the fat, the higher levels of thickener can affect adversely the pumpability characteristics of the fat Another thickener system that has been used with significant success and as an alternative to the previous ones P1361-96MX f thickeners soap complex is polyurea. The polyurea thickener has numerous qualities of excellence that make it a superior thickener for fats for some applications compared to complex thickeners of lithium, calcium and aluminum. The polyurea exhibits no lacquer deposition at elevated temperature and generally has acceptable pumpability characteristics. The drip point of the polyurea is about -50 ° F (232.22 ° C) and often above 500 ° F (260 ° C). When the fats thickened with polyurea show their dropping point, it is usually due to the inability of the thickener to retain the oil and not due to the fusion of the polyurea. This is in contrast to most complex soap thickeners that usually melt at their drip points. Despite the many advantages of thickeners * Polyurea thickeners have various attributes that limit their usefulness as a thickener for lubricating grease Polyurea thickened fats retain their original consistency quite well when subjected to high cutting forces, but can often soften Significant when subjected to lower shear forces For example, in ASTM D-1403 penetration tests at 100,000 strokes, polyurea greases usually soften from 60 to 100 points or more.

P1361-96MX "The imilar softening effects can occur when polyurea fats are subjected to the tests of Stability to Bearing ASTM D-1831. Polyurea thickened fats can also have oil separation characteristics that increase significantly and undesirably as the temperature of the application increases. This is a characteristic also exhibited by many fats thickened with soap J 'complex. Moreover, polyurea thickeners are generally more expensive than complex soap thickeners, which provides great incentives to reduce or eliminate the use of polyurea in lubricating greases. Several patents of the United States of America present fat compositions containing thickeners containing lithium. For example, US Pat. No. 2,997,956 to Fraser, discloses a fat composition comprising a grease-forming lubricant base and a lithium soap of 12-hydroxystearic acid.12-Hydroxystearic acid is supplied in an amount that increases the ability of the grease to maintain its consistency when mechanically working The United States Patent No. 4,897,210 from Newsoroff, presents a thickener for complex lithium fat comprising a lithium salt of acid P1361-96MX, 2-hydroxy stearic or alkyl esters thereof in combination with a dilithium salt derived from dialkyl esters of terephthalic acid in a molar ratio of about 0.5 to 15: 1. The grease has lubricating activity, stability to the cut, resistance to the water and high point of dripping. The Patent of the United States of America No.

No. 5,242,610 to Doner et al., Discloses a fat composition comprising an alkaline or alkaline earth metal or amine derivative of a hydroxy-containing or polyhydroxy-containing soap thickener, such as 12-hydroxystearic acid and a borated derivative of an organic compound. . The fat has important characteristics of drip point. Many other United States Patent of America present fat compositions containing urea-containing components. For example, U.S. Patent No. 5,145,591 to Kinoshita et al., Discloses a diurea-containing fat composition. Diurea fat maintains its consistency at elevated temperatures. U.S. Patent No. 5,059,336 to Naka et al., Discloses a fat composition comprising a synthetic lubricating base oil, a thickening agent consisting of a urea compound, P1361-96MX Sorbitan dinoleate, barium sulfonate and barium lanolate. The grease has properties that prevent oxidation and is particularly effective for use with high speed roller bearings. The Patent of the United States of America No.

No. 5,043,085 to Kinoshita et al., Discloses a fat composition comprising a base oil, a thickener selected from the group consisting of urea compounds, J "urethane compounds and mixtures thereof and a selected ingredient of the group consisting of oxidized paraffins, diphenyl hydrogen phosphite, hexamethyl phosphate triamide and mixtures thereof Fat provides improved properties to prevent rubbing when applied to sliding or part-joining portions to restrict relative movements or to support movements Fine reciprocals US Pat. No. 5,011,617 to Fagan presents a thickened polyurea complexed fat composition containing less than 7 parts per million of 2,4-diaminotoluene and a process for making this fat. process comprises reacting an isocyanate, a polyamine and a monoamine, with a main portion of a lubricating oil after of which, an alkaline earth metal oxide or hydroxide and a carboxylic acid anhydride are added to the mixture.

P1361-96MX tle contains from 2 to 20 carbon atoms, after which it is ground to the fat consistency. The fat is prepared in such a way that it does not contain detectable 2,4-diaminotoluene that Fagan claims causes cancer in laboratory animals. The Patent of the United States of America No.

No. 4,692,255 to Matzat et al., Discloses a fat composition comprising a polyurea thickener and a method for preparing the polyurea thickener. The thickener is the isocyanate reaction product and at least three isocyanate groups in the molecule with a long chain, short chain or branched aliphatic monoamine. The thickened fat results in an increase in temperature and wear properties. The Patent of the United States of America No. 3,846,314 to Dreher et al., Discloses a fat composition comprising a mono or polyurea compound having from 1 to 8 ureido groups and having a molecular weight of between about 375 and 2500 and an aliphatic carboxylate of alkaline earth metal having from 1 to 3 carbon atoms. The weight ratio of the alkaline metal carboxylate to the mono and polyurea compounds is from 1 to 15. The composition of the grease is particularly useful at high temperatures. The Patent of the United States of America No.

P1361-96MX 3,243,372 by Dreher et al., Presents a fat composition which. it comprises polyurea of at least 4 urea groups having terminal hydrocarbon end members. The composition of the grease is particularly effective at elevated temperatures. Fats and thickener systems of the ~ "Prior art identified above, have achieved variable degrees of success and have been subjected primarily to the various limitations and application restrictions previously described. The combination of a mixed thickener package consisting of polyurea and calcium soap has also been taught in the art. U.S. Patent No. 5,084,193 to Waynick, discloses a fat composition having a mixed thickener package consisting of polyurea and calcium soap. The polyurea and calcium soap thickener package reduces lacquer deposit, hardening at high temperature, surface / aging hardening and has superior oil separation properties. It has now been found that a lubricating grease comprising a thickener package comprising a lithium soap thickener and a thickener containing urea, provides a synergistically superior performance to Pliei-lb X.as fats that either comprise thickener individually or to the expected results of a mathematical mixture of thickener systems. It has also been found that a grease comprising a thickener package comprising a lithium soap thickener and a thickener containing urea provides a synergistically superior performance over a wider range and with a better cost-benefit ratio of soap thickener proportions. containing urea compared to identical fats where calcium soap thickener was used instead of a lithium soap thickener. It has also been found that the addition of a critically focused amount of boric acid to a fat comprising a thickener pack comprising a lithium soap thickener and a thickener containing urea, gives results superior to those achieved without the addition of boric acid. . It has also been found that the fat preparation steps comprise the heating of the fat comprising a thickener package comprising a lithium soap thickener, a thickener containing urea and a critically focused amount of boric acid at temperatures in excess of 200 ° F (93.33 ° C), provides superior results to fats prepared from P1361-96MX. Processing steps maintained at temperatures below 200 ° F (93.33 ° C). Therefore, it is an object of the present invention to provide a lubricating gauze having superior characteristics of oxidation, hardening and drip point stability to lubricating greases containing complex or simple metallic soap salts of fatty acid thickeners alone. . "- Another object of the present invention is to provide a lubricating grease having improved cut stability and oil separation properties and cost advantages compared to fats containing only thickeners containing urea. present invention is to provide a lubricating grease which exhibits remarkable drip point characteristics at sustained high levels of operating temperature while maintaining excellent penetration properties.Other objects will appear herein.

SUMMARY OF THE INVENTION The above objects can be achieved by providing a lubricating grease comprising a bae oil, an additive package, a thickener containing urea and a lithium soap thickener.

P1361-96MX In another embodiment, the foregoing objectives can be achieved by providing a lubricating grease comprising a base oil, an additive package and a mixed thickener system comprising a thickener containing urea and a lithium soap thickener, wherein the lithium soap thickener comprises from about 30 percent to about 95 percent of the mixed thickener system, calculated by weight. In another embodiment, the above objectives can be achieved by providing a lubricating grease comprising a base oil, an additive package, a mixed thickener system comprising a thickener containing urea and a lithium soap thickener wherein the lithium soap thickener comprises from about 30 percent to about 95 percent of the mixed thickener system, calculated by weight and boric acid in an amount ranging from about 0.1 weight percent to about 2.0 weight percent calculated as a percentage of the lubricating fat. The lubricating grease according to the present invention achieves numerous performance benefits not achieved by the lubricating greases of the prior art. The lubricating grease provides a stability to the cut, a drip point, a separation of oil in a P1361-96MX implio range of temperatures, resistance to wear by rubbing and improved thermal stability and oxidation. The lubricating grease according to the present invention maintains its thickening power and its pumpability characteristics in contrast to the complex thickeners of the prior art composed entirely of metallic soap salts of fatty acids. The lubricating grease according to the present invention generally shows no problems of deposition of lacquer which are common with fats exclusively containing thickeners of lithium soap or aluminum soap. In addition, the thickened fats with the thickener system of the present invention show a substantially less severe hardening at elevated temperature, a characteristic often associated with fats thickened with calcium complex. Similarly, surface / aging hardening is also reduced. The lubricating grease according to the present invention can be used as lubricating grease for a wide range of applications including but not limited to extreme pressure and anti-wear conditions. The additives commonly used in thickened, soap-free and thickened with soap, can also be used in thickened fats with the system P1361-96MX "^" improved thickener of the present invention, thus providing the grease manufacturer with a high degree of flexibility by means of which improved products can be developed.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a graph of the drip point in ° F (ASTM D-2265) Worked at 10,000 Blows in comparison - '"' - with the percentage of fat 1 (lithium soap thickener) expressed as a percentage of total fat 1 and 2 (thickeners of lithium soap and containing urea). Figure 2 is a graph of the Drip Point in ° F (ASTM D-2265) worked at 10,000 strokes compared to the percentage of fat 4 (calcium soap thickener) expressed as a percentage of total fat 4 and 5 (thickeners of calcium soap and containing urea). ~: 'Figure 3 is a graph of the Drip Point in ° F (ASTM D-2265) Worked at 10,000 strokes compared to the weight percent of boric acid in the grease for fats 16 to 20. Figure 4 is a plot of the Drip Point in ° F (ASTM D- 2265) Worked at 10,000 strokes compared to the oven temperature in ° F of the grease for fats 21 to 16.

P1361-96MX BRIEF DESCRIPTION OF THE INVENTION A lubricating grease having cutting stability, dripping point, oil separation over a wide range of temperatures, resistance to rubbing wear and superior thermal and oxidation stability is provided which is particularly useful for lubricate wheel bearings, steel mill bearings, CV joints such as those found in automotive - front-wheel drive, fifth-axis wheels in semitrailers, high-speed flexible couplings, universal joints and other devices that require the application of a superior performance grease. The lubricating grease comprises an oil base, an additive package, a thickener containing urea and a lithium soap thickener. The thickener component containing urea suitable for use with the present invention may be a thickener component of monourea, diurea, triurea or polyurea. The preferred thickener containing urea is polyurea. ~~~~ The mono- and polyurea compounds suitable for use with the present invention generally have structures defined by the following formulas: P1361-96MX O R -NH C -NH-R -NH-C -NH -R -NH C -NH - R. (3) 1 2 3 (where n is an integer from 0 to 3, Rx is the same hydrocarbyl or a different hydrocarbyl having from 30 carbon atoms and preferably from 10 to 24 carbon atoms, R 2 is the same hydrocarbylene or a hydrocarbylene different having from 2 to 30 carbon atoms and preferably from 6 to 15 carbon atoms; and R3 is the same hydrocarbylene or a different hydrocarbylene having from 1 to 30 carbon atoms and preferably from 2 to 10 carbon atoms. As referred to herein, the hydrocarbyl group is a monovalent organic radical consisting essentially of hydrogen and carbon and which may be aliphatic, aromatic, alicyclic or combinations thereof. The hydrocarbyl group can include, but is not limited to, aralkyl, aryl, cycloalkyl and It can be saturated or olefinically unsaturated (one or more conjugated or unconjugated carbon double bonds). The hydrocarbylene, as defined in R2 and R3 above, is a divalent hydrocarbon radical which may be aliphatic, alicyclic, aromatic or combinations thereof, such as alkylaryl, aralkyl, alkylcycloalkyl and cycloalkylaryl and which have their two free valences in different atoms of carbon. The mono- or polyureas having the structure presented in Formula (1) above, are prepared by reacting n + l moles of diisocyanate with 2 moles of a monoamine and n moles of a diamine. When n equals 0 in the above Formula (1), the diamine is removed. The mono- or polyureas having the structure presented in the above Formula (2), are prepared by reacting n moles of a diisocyanate with n + 1 moles of a diamine and 2 moles of a monoisocyanate. When n equals 0 in the above Formula (2), the diisocyanate is removed. The mono- or polyureas having the structure presented in the above Formula (3), are prepared by reacting n moles of a diisocyanate with n moles of one diamine and 1 mole of a monoamine. When n is equal to 0 in the above Formula (3), both the diisocyanate and the diamine are removed. P1361-96MX In the preparation of the above mono- or polyureas, the reactants (diisocyanate, monoisocyanate, diamine and monoamine) are generally mixed in a vessel as appropriate. The composition can be prepared with or without a catalyst and is generally initiated by contacting the reactants at the conductive processing conditions of the reaction. Typical reaction conditions generally include a reaction temperature ranging from about 70 ° F (21.11 ° C) to about 210 ° F (98.89 ° C) at atmospheric pressure. The reaction is generally exothermic and by initiating the reaction at room temperature high temperatures are obtained. Heating or external cooling can also be used to facilitate the reaction. The reaction can also be carried out in the presence of a solvent. Generally, a portion of the base oil that will be used in grease formation is used or functions as a solvent. In this way, the polyurea thickener is generated within the oil base and a fatty structure is obtained as the reaction proceeds. The monoamine or monoisocyanate used in the mono- or polyurea formulation can form end groups. terminals. These terminal end groups can have from 1 to 30 carbon atoms, but P1361-96MX preferably have from 5 to 28 carbon atoms and, more preferably, from 10 to 24 carbon atoms for the best results. Illustrative of various monoamines include, but are not limited to: pentylamine, hexylamine, heptylamine, octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, eicosylamine, dodecenylamine, hexadecenylamine, octadecenylamine, octadecadienylamine, abiethylamine, aniline, toluidine, naphthylamine, cumylamine, bornylamine, pyrilamine, tertiary butyl aniline, benzylamine and beta-phenethylamine. Preferred amines are prepared from natural fats and oils or from the fatty acids obtained therefrom. These starting materials can be reacted with ammonia to provide amines and then nitriles. The nitriles are reduced to amines by catalytic hydrogenation. Exemplary amines prepared by the method include, but are not limited to: stearylamine, laurylamine, palmitylamine, oleylamine, petroselinylamine, linolethylamine, linolenylamine and eleostearylamine. Unsaturated amines are particularly useful for preparing the thickener containing urea. Illustrative examples of monoisocyanates are: hexyl isocyanate, decyl isocyanate, dodecylisocyanate, tetradecylisocyanate, hexadecylisocyanate, phenylisocyanate, cyclohexyl isocyanate, xyloisocyanate, cumenoisocyanate, P1361-9bMX abiethylisocyanate and cyclooctylisocyanate. The polyamines that form the internal hydrocarbon bridges gelly contain from 2 to 40 carbon atoms, preferably from 2 to 30 carbon atoms and, more preferably for best results, from 2 to 20 carbon atoms. The polyamine gelly has from 2 to 6 amine nitrogens, more preferably from 2 to 4 amine nitrogens and, more preferably, 2 amine nitrogens. These polyamines may include, but are not limited to: diamines such as ethylenediamine, propanediamine, butanediamine, hexanediamine, dodecanediamine, octanediamine, hexadecanediamine, cyclohexanediamine, cyclooctanediamine, phenylenediamine, tolylenediamine, xylenediamine, dianiline methane, ditoluidinomethane, bis (aniline), bis ( toluidine), and piperazine; triamines such as aminoethylpiperazine, diethylenetriamine, dipropylenetriamine and N-ethyldiethylenetriamine; and polyamines such as triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine. Representative examples of diisocyanate include: hexanediisocyanate, decannediisocyanate, octadecanodiisocyanate, phenylene diisocyanate, tolylene diisocyanate, bis (diphenylene diisocyanate) and methylenebis (phenylisocyanate). P1361-9bMX Other mono- or polyurea compounds that can be used accord with the formula: where n is an integer from 1 to 3, R2 is defined above, and X and Y are monovalent radicals selected from the following: where R ^. is defined supra, R3 is defined above, R4 is selected from the groups consisting of arylene radicals having from 6 to 16 carbon atoms and from alkylene groups having from 2 to 30 carbon atoms and, R5 is selected from the group consists of alkyl radicals having 10 to 30 carbon atoms and aryl radicals P1361-96MX which have 6 to 16 carbon atoms. The mono- or polyurea compounds described by the above Formula (4) can be characterized as amides and imides of mono-, di- and triureas. These materials are gelly formed by reacting suitable internal carboxylic acids or carboxylic anhydrides with a diisocyanate and a polyamine with or without a monoamine or monoisocyanate. The mono- or polyurea compounds are prepared by mixing the reagents in a contaiand heating the contaito a temperature ranging from about 70 ° F (98.89 ° C) to about 400 ° F (204.44 ° C) for a sufficient period to cause the formation of the compound. The time gelly required for the reaction can vary from 5 minutes to 1 hour and, the reactants can be added all at once or sequentially. The above mono- or polyureas can be mixtures of compounds having structures where n or nx vary from 0 to 8, n or n! they vary from 1 to 8, existing at the same time within the fat composition. For example, when a monoamine, a diisocyanate and a diamine are all present within a reaction zone, as in the preparation of ureas having the structure shown in the above Formula (2), some of the monoamine may react with both sides of diisocyanate P1361-96MX to form diurea (biurea). In addition to the diurea formulation, simultaneous reactions may occur to form tri-, tetra-, penta-, hexa-, octa-, and higher polyureas. Biurea (diurea) can also be used as a thicke but it is not as stable as polyurea and when pumped it can split and lose consistency. Triurea can also be used with or in place of the mono-, di- and potyureas presented herein. The urea-containing thickecan also be prepared by removing the diamine or polyamine components described above and reacting the two remaining components in the presence of water. The water reacts with the diisocyanate and getes an in-situ diamine component. This method to formulate the urea-containing thickeis preferred because when it is properly implemented, the method results in a one-step excess removal of the unreacted isocyanate portions of the final fat. When water is used as a reactant, the reaction conditions are similar to those discussed above. The reaction is preferably carried out in at least a portion of the base oil used to formulate the fat. An example of the urea-containing thickener suitable for use with the present invention and the method of preparation is given below. The P1361-96MX reactants to form the urea-containing thickener include the following: 1. A diisocyanate or a mixture of a dissociant having the formula OCN-R6-NCO, wherein R6 is a hydrocarbylene having from 2 to 30 carbon atoms, preferably from 6 to 15 carbon atoms and, more preferably, 7 carbon atoms. 2. A polyamine or a mixture of polyamines having a total of 2 to 40 carbon atoms and having the formula: wherein R7 and RT are the same hydrocarbyls or different types of hydrocarbyles having from 1 to 30 carbon atoms, preferably from 2 to 10 carbon atoms and, more preferably, from 2 to 4 carbon atoms; Rg is selected from hydrogen or an alkyl of c? a c4 and i preferably hydrogen; x is an integer from 0 to 4; and is 0 or 1; and z is an integer equal to 0 when y is 1 and equal to 1 when y is 0. 3. A monofunctional component selected from the group consisting of monoisocyanate or a mixture of monoisocyanate having from 1 to 30 carbon atoms, P1361-96MX preferably from 10 to 24 carbon atoms and mixtures thereof. The reaction may be carried out by contacting the three reactants in a suitable reaction vessel at a temperature ranging from 60 ° F (15.56 ° C) to 320 ° F. (160 ° C) and, preferably between 100 ° F (37.78 ° C) and 300 ° F (148.89 ° C), for a period of 0.5 hours to 5 hours and, preferably, for a period of 1 to 3 hours. The * ~ molar ratio of the reactants present may vary from 0.1 to 2.0 moles of monoamine or monoisocyanate and 0.0-2.0 moles of polyamine per mole of diisocyanate.

When monoamine is used, the molar amounts may be m + 1 mols of diisocyanate, m mols of polyamines and 2 mols of monoamine. When monoisocyanate is used, the molar amounts may be moles of diisocyanate, m + 1 moles of polyamine, and 2 moles of monoisocyanate where m is a number from 0.1 to 10, preferably from 0.2 to 3, and more preferably 1. The thickener of lithium soap of the present invention can also be prepared in various forms. To manufacture a lithium soap thickener, a base containing lithium and a fatty monocarboxylic acid, ester, amide, anhydride or other fatty monocarboxylic acid derivative is generally required. When the two materials react with each other, usually while they are P1361-96MX in the form of pulp, dispersed or suspended in some other way in the base oil that will be used in the fat, in the base oil a lithium carboxylate salt or a mixture of salts is formed. The salt or lithium salts formed, thicken to the oil thus facilitating a fat-like texture. During the reaction, the water may or may not be present to assist in the formation of the thickener. Simple lithium soap thickeners generally comprise "" "at least a minor portion of monocarboxylic acids or fatty acid derivatives with, preferably, a hydroxyl group on one or more of the carbon atoms of the fatty chain for better stability of the grease structure The lithium base material used in the thickener can be lithium oxide, lithium carbonate, lithium bicarbonate, lithium hydroxide, or any other A substance containing lithium, which, when reacted with a monocarboxylic acid or a monocarboxylic acid derivative, provides a lithium carboxylate thickener. Lithium hydroxide monohydrate is the preferred substance containing lithium. Desirably, the monocarboxylic fatty acids or their derivatives used in simple lithium soap thickeners have a moderately high molecular weight of from 7 to 30 carbon atoms.

P1361-96MX carbon, preferably, 12 to 30 atoms and even more preferably, 18 to 22 carbon atoms. Suitable monocarboxylic acids or derivatives thereof may include lauric, myristic, palmitic, stearic, behenic, myristoleic, palitoleic, oleic and linoleic acids. Also vegetable or plant oils such as rape seed oils, sunflower, safflower, cottonseed, palm, castor and corn, and animal oils such as fish oil, hydrogenated fish oil, lard oil and beef oil can be used as a source of moncarboxylic acids in simple lithium soap thickeners. Various nut oils or the fatty acids derived therefrom can also be used in simple lithium soap thickeners. These oils generally comprise triaciclglycerides. The tricyclicglycerides can be reacted directly with the lithium-containing base or the fatty acids can be split from the triglyceride backbone, separated and reacted with the lithium-containing base as free acids. Hydroxy monocarboxylic acids are preferred in simple anhydrous lithium soap thickeners and may include any counterpart of the preceding acids. The most widely used hydroxy-monocarboxylic acids are 12-hydroxystearic acid, P1361-96MX 14-hydroxystearic acid, 16-hydroxystearic acid, 6-hydroxystearic acid and 9,10-dihydroxystearic acid. Likewise, any fatty acid derivatives containing any of the hydroxy carboxylic acids can be used. In general, monocarboxylic acids and hydrocarboxylic acids can be saturated or unsaturated, straight or branched chain. To form simple lithium soap thickeners, esters, amides, anhydrides or any other derivative of these monocarboxylic acids can be used instead of the free acids. For best results, the preferred derivative of the monocarboxylic and hydroxy monocarboxylic acids is the free carboxylic acid. When preparing simple lithium soap thickeners by reacting the lithium base and the monocarboxylic acid or a mixture of monocarboxylic acids or derivatives thereof, it is preferred that the lithium base be added in an amount sufficient to react with all the acids and / or with all the acid derivatives. It is also generally advantageous to add an excess of the lithium base to more comfortably facilitate the complete reaction. The amount of excess lithium base depends on the processing severity that the base fat will experience. The more time P1361-96MX heat the base grease and the higher the maximum heat treatment temperature, the lower the lithium base excess will be required. During the formation of the simple anhydrous lithium soap thickener, the thickener formation reaction is usually carried out at elevated temperatures ranging from about 150 ° F (65.56 ° C) to about 320 ° F (160 ° C). Water may or may not be added to facilitate a better reaction or a more complete reaction. Preferably, the water added at the beginning of the processing as well as the water formed from the thickener reaction is evaporated by heat, vacuum or both. The reaction of the thickener is generally effected after the addition of a portion of the base oil as previously described. After the thickener has formed and any water has been removed, the resulting lithium soap thickener can optionally be heated to about 400 ° F (204.44 ° C), until the lithium soap melts. This will ensure the complete reaction of the base containing lithium and the fatty acid. The melted fat is then cooled to reform the base grease. The mixed thickener system comprising the thickener containing urea and the lithium soap thickener can be produced by various methods. One of P1361-9bMX these methods for the preparation of the mixed thickener system is to form each thickener component separately in separate containers and after which, mix the resulting fats. The individual fats thickened with polyurea or with lithium soap may include sufficient base oil for the final fat product or, more base oil may be added during or after the two thickener components were mixed. However, generally thickened fats containing urea and lithium soap are manufactured so that the resulting fat containing the mixed thickener has a harder consistency than that required by the final grease. Then, additional additives and base oil can be added to soften the fat to its desired consistency. Another process for manufacturing the mixed thickener system comprising thickeners, the one containing urea and * "The lithium soap, is to sequentially form each thickener system in the same container." When this method is used, the first thickener component is formed and a base fat thickened by this component is produced. second thickener component by reacting the appropriate components within the base fat thickened by the first thickener component Sufficient oil base is added either exactly at the beginning of the process P1361-96MX manufactures or after the formation of the first thickener component, so that the formation of the second thickener component does not produce a thickened fat containing urea and lithium soap which is very hard to stir in the reaction vessel. When the thickeners, the one containing urea and the one containing lithium soap react sequentially in the same reaction vessel, each thickener "" "" / form by the same procedures that were used when they were formed in separate containers. The order in which the thickeners are formed, the one that contains urea and the one of lithium soap, is not critical and both orders can produce favorable results. However, for best results, it is preferable that the urea-containing thickener be formed first. If the lithium soap thickener is first formed and any unreacted free acids remain, these can interfere with the formation of the urea-containing thickener. Polyurea has also been found to act as an excellent promoter in the reaction of carboxylic acids with lithium-containing bases The presence of the urea-containing components mitigates the need for the addition of water to react the lithium-containing base with the carboxylic acid.

P1361-96MX formed sequentially in the same kettle, the resulting thickened base fat containing urea and lithium soap is dried by heat, vacuum or both, followed by a heat treatment. The maximum heat treatment temperatures of thickened fat containing urea and lithium soap, when manufactured by sequentially forming the thickeners in the same container, should generally not exceed 400 ° F "" * "'(204.44 °) C), preferably not exceeding 350 ° F (176.67 ° C) 0 and, more preferably, for best results not exceeding 325 ° F (162.78 ° C) .The thickener system containing urea and lithium soap may comprise any proportion of the two thickener components, assuming that the component in minor amount comprises at least 1% by weight of the total thickener _ in the final grease.

• Thickened by the thickening system containing urea and lithium soap, it should have a total thickener level of between about 6% to about 20% and more preferably from about 10% to about 16% by weight of the fat lubricant for best results The preferred composition of the thickener system, as a percentage calculated by weight, is one in which the lithium soap thickener comprises from about 30% to about 95% of the total P1361-96MX thickener and, more preferably, for best results from about 60% to about 90% of the total thickener. For the purposes of developing, measuring and identifying fats in accordance with the ranges set forth above, the thickeners containing urea and lithium soap are each prepared to substantially similar levels of penetration as determined according to the ASTM-D test procedure. -1403 While the range of composition set forth above is directed to thickener components containing urea and lithium soap having similar penetration levels, to reflect equivalent ranges for thickeners containing urea and lithium soap having unequal penetrations, equivalent ranges can be determined. Of composition. While the above thickener composition is preferred for best results, if desired, other amounts of thickeners containing urea and lithium soap may be used depending on the intended application and the desired properties of the fat. The qualities of the thickener system of the lubricating grease according to the present invention can be further improved with the addition of a particularly focused amount of boric acid. The preferred amount of boric acid, calculated as a percentage of Pl.ol-? .MX the lubricating grease, varies from about 0.1 wt% to about 2.0 wt% and, more preferably, for better results from about 0.2 wt% to about 1.2 wt%. Boric acid can be added to lubricating grease in the form of boron oxide, which reacts with water to form boric acid. If desired, other boron-containing materials, such as borate, metaborate or pyroborate salts such as metaborate (-3303 (011) 3) can be used instead of boric acid. Preferred metals for use with any of the borate, metaborate or pyroborate salts are sodium and potassium. The performance of the lubricating greases prepared in accordance with the present invention and which further comprise the addition of boric acid, can be further improved, by the steps of formulating the particular fat. It has been found that when boric acid is added to the lubricating fat formulation, the temperature at which the heat treatment step is conducted in the subsequent addition of boric acid can substantially affect the characteristics of the drip point ASTM D-2265 of the grease. The rate of increase in the dropping point with the heat treatment temperature is accelerated to temperatures in excess of 200 ° F (93.33 ° C) and, preferably in excess of 250 ° F (121.11 ° C).

P1361-96MX Therefore, a further increase in the drip point of the lubricating grease can be obtained through the addition of a critically focused amount of boric acid. The base oils used with the thickener system of the present invention may be any of the many known base oils that are commonly reported and used in prior art lubricating greases. The base oil may comprise naphthenic, paraffinic or aromatic hydrocarbon or may be a synthetic oil such as a polyalphaolefin, polyester, polyester ester, diester, polyalkyl ethers, polyarylethers, silicone polymer fluids or combinations thereof. The viscosity of the base oil can vary from about 50 to about 10,000 SUS at 100 ° F (37.78 ° C). Suitable base oils may also include: (a) oil derived from carbon products, (b) alkylene polymers, such as polymers of propylene, butylene, etc., (c) polymers of the alkylene oxide type, such as Alkylene oxide polymers prepared by the polymerization of alkylene oxide (for example, polymers of propylene oxide in the presence of water or alcohols such as ethyl alcohol), (d) carboxylic acid esters, such as those which are P1361-96MX prepare by the esterification of carboxylic acids such as adipic acid, azelaic acid, suberic acid, alkenyl succinic acid, fumaric acid, maleic acid with alcohols such as butyl alcohol, hexyl alcohol and 2-ethylhexyl alcohol, (e) liquid esters of phosphorus acid, (f) alkyl benzenes, (g) polyphenols such as biphenols and terphenols, (h) alkyl biphenol ethers and (i) silicon polymers such as tetraisopropyl silicate, tetra (4-methyl-2-tetraethyl) silicate ), Hexyl disilicone (4-methoxy-2-pentoxy), poly (methyl) siloxane, and poly (methyl) phenylsiloxane. Most of the additives used in the lubricating greases of the prior art can be used successfully in thickened greases by the thickener system containing urea and lithium soap of the present invention. The various types of additives available and their functions are generally well known to those skilled in the art. The lubricating grease according to the present invention has improved performance properties compared to the known grease generally of the prior art. Among the improved properties are those of shear stability, drip point, oil separation over a wide range of temperatures, wear resistance by rubbing and P1361-96MX thermal stability and oxidation. Unlike the metallic soap salt of the aforementioned fatty acid thickeners, the improved thickener system of the present invention resists the loss of thickening characteristics while maintaining its pumpability properties. The thickened fats with the thickener system of the present invention do not show the lacquer deposit characteristics that are common when using exclusively lithium soap thickeners and aluminum thickeners. Also, the high temperature cure associated with the thickened fats with calcium complex, is shown to a much lesser degree, if at all, when using the improved thickener system of the present invention. Advantageously, the surface / aging hardening is also substantially reduced. The improved properties of the thickener system containing urea and lithium soap of the present invention are particularly surprising and unexpected, since they significantly exceed the mathematically expected levels of the individual properties, qualities and characteristics of the individual components containing urea and soap. lithium. It has been found that thickeners containing urea and lithium soap do not function as a mixture of thickeners containing urea and lithium soap but that P1361-96MX interact favorably and in a way that was not anticipated by the linear combination of the components. The improved thickener system of the present invention can be used in lubricating greases for a wide range of applications, but which is not limited to extreme pressure and antiwear conditions.

The additives commonly used in soap-and-soap-free thickened fats can also be used in thickened fats with the improved thickener system of the present invention, thus providing the fat manufacturer with a high degree of flexibility by which products can be developed. improved. The lubricating grease of the present invention is described in further detail in connection with the following examples, it being understood that they are for purposes of illustration only and not of limitation.

EXAMPLE 1 A lithium soap thickener composition comprising lithium soap and mineral oil weighing 40 was prepared and formulated to satisfy a penetration ASTM D-1403 of between 265 and 275 worked at 60 strokes for use in the preparation of grease compositions in accordance with the present invention. Approximately 6,810 grams of a paraffinic mineral oil, hydrotreated, P1361-9TMX xtrayed by solvents weighing 40 and having a viscosity of about 850 SUS at 100 ° C, was added to a lab kettle for fat. The oil was heated and stirred until the temperature reached 170 ° F (76.67 ° C). The oil heated. it was combined with 2340.2 grams of methyl 12-hydroxystearate and the mixture was stirred until the methyl 12-hydroxystearate was melted. Approximately 318.4 grams of lithium hydroxide monohydrate and 50 grams of water were added to the mixture and the fat kettle was sealed and kept without adding heat for a period of 30 minutes. The mixture was then heated to 300 ° F (76.67 ° C) and maintained at that temperature for a period of 35 minutes. The kettle was subsequently ventilated and opened. The batch was then heated to 400 ° F (204.44 ° C) under a nitrogen cloud and maintained at 400 ° F (204.44 ° C) for 15 minutes. The addition of heat to the mixture was reduced in such a way that the temperature of the mixture dropped to 250 ° F (121.11 ° C). Once the mixture reached 250 ° F (121.11 ° C), an additional 2.270 grams of mineral oil weighing 40 was added and the mixture was cooled to 150 ° F (65.56 ° C). A 10-pound portion of the mixture was blended with 2.8 pounds of mineral oil weighing 40, stirred and heated to 200 ° F (93.33 ° C). Approximately 7.2 pounds of paraffinic mineral oil, hydrotreated, extracted with P1361-96MX solvents, weighing 10 and having a viscosity of approximately 160 SUS at 100 ° C were uniform in the mixture for a period of 30 minutes and the mixture was cooled to a temperature of approximately 150 ° F (65.56 ° C) ). The mixture was ground in an Eppenbach mill and the fat product was identified as Fat 1. The penetration (ASTM D-1403) of Fat 1 worked and not worked at 60, 10,000 and 100,000 strokes and the drip point (ASTM D-2265) worked at 10,000 and 100,000 strokes are shown in Table 1. The drip point worked at 10,000 strokes is plotted on the Figure 1.

EXAMPLE 2 For use in the preparation of fat compositions according to the present invention, a thickener composition containing urea and comprising polyurea and a mixture of mineral oils weighing 10 and weighing 40 was prepared.

Approximately 14.94 pounds of a mineral oil weighing 40 was added to a laboratory flask for fat, shaken and heated to a temperature of 175 ° F. (79.44 ° C). Once the mineral oil with a weight of 40 reached 175 ° F (79.44 ° C), the kettle was added 2. 95 pounds of fatty amine, sold under the brand name of Armeen T by Akzo Chemicals, Inc., where it was melted and mixed P1361-96MX well with mineral oil weighing 40. After mixing, approximately 3.3 pounds of water were added and the mixture was mixed for a period of about 5 minutes. The mixture was allowed to cool to a temperature of 130 ° F (54.44 ° C). To the mixture was added a 3.35 pound load of Mondur M, 4, 4 '-diphenylmethane diisocyanate, sold by Mobay Chemical Corporation in 3 equal portions and to the mixture was added 2.07 pounds of additional mineral oil weighing 40. The kettle was closed and the mixture was mixed without heating for a period of about 30 minutes. The mixture was heated to a temperature of about 310 ° F (154.44 ° C), the kettle was vented and opened and the mixture was reheated to a temperature of about 310 ° F (154.44 ° C). Approximately 10.08 pounds of mineral oil weighing 10 was added to the mixture and the mixture was heated to 400 ° F (204.44 ° C), while the kettle remained open and covered with nitrogen. Once the mixture reached 400 ° F (204.44 ° C), the mixture was maintained at a temperature between 390 ° F (198.89 ° C) -400 ° F (204.44 ° C), for a period of 15 minutes. The mixture was cooled to 350 ° F (176.67 ° C) after which 3.17 pounds of mineral oil weighing 40 and 5.44 pounds of mineral oil weighing 10 was standardized and the mixture was cooled to 175 ° F (79.44 °). C). The fat mixture was milled in a mill P1361-96MX Gaulin at 8,000 psi and the fat product was identified as Fat 2. The penetration (ASTM D-1403) of Fat 2 not worked and worked at 60, 10,000, and 100,000 strokes and the drip point (ASTM D -2265) worked to 10,000, and 100,000 strokes are shown in Table l. The drip point worked at 10,000 strokes is shown in Figure 1. The drip point worked at 10,000 strokes was re-tested * "*" during the comparison tests of a calcium soap grease and these results are shown in Table 2 and are shown in Figure 2.

EXAMPLE 3 Greases 1 and 2 were mixed in various proportions to demonstrate the synergistic benefits of combining the lithium soap thickeners and urea-containing thickeners formulated in accordance with the present invention. Greases 1 and 2 were mixed in mixtures of 1200 grams passed per roller mill in composition ratios of 20, 40, 50, 60, and 80 percent of Fat 1 (lithium soap thickener) calculated as a percentage of the weight total of Fat 1 and Fat 2 (thickener containing urea). These fats were identified as Fats 3, 4, 5, 6 and 7, respectively. The penetration (ASTM D-1403) of Greases 3-7 not worked and worked at 60, P1361-96MX 10,000 and 100,000 strokes and the drip point (ASTM D-2265) worked at 10,000 and 100,000 strokes are all shown in Table 1. Drip points worked at 10,000 strokes are also plotted in Figure 1. Figure 1 includes all drip points ASTM D-2265 at 10,000 strokes for Greases 1 through 7. Figure 1 also includes the linear regression of the drip points of Fats 1 through 7 as a function of the percentage of Fat 1 compared to the total of the Combined Fats 1 and 2. Examples 1-3 and Figure 1 clearly illustrate that combining lithium soap thickeners and thu contain urea and in accordance with the present invention, provides synergistic, surprising and unexpected advantages at the drip point compared to the expected drip point of a linear combination of thickeners. This drip point synergy is particularly predominant in the range of percentage of lithium soap thickener to total lithium soap thickener plus urea-containing thickener of from about 30 percent to about 95 percent, and is especially prevalent to a percentage of lithium soap thickener to the total lithium soap thickener plus the urea-containing thickener of approximately 80 percent.

P1361 -96MX TABLE 1 GREASE 1 2 3 4 5 6 7 COMPOSITION OF% FAT IN WEIGHT Grease 1 (Lithium soap) 100 0 20 40 50 60 80 Fat 2 (Containing urea) 0 100 80 60 50 40 20 TESTS Penetration, complete (ASTM D-1403) Not worked 261 207 258 257 263 268 270 Worked-60,000 blocks 257 267 263 270 271 277 275 Worked-10, 000 blocks 262 341 327 309 309 303 291 Worked-100,000 blocks 295 351 241 327 321 319 309 Drip point, ° F (° C) (ASTM D-2265) (Block 550 ° F (287.78 ° C)) Worked - 10,000 blocks 377 531 521 511 511 483 495 Worked-100, 000 blocks 429 512 509 512 515 512 488 EXAMPLE 4 To be used in the preparation of fat compositions for comparison with fat compositions according to the present invention, a calcium soap thickener composition comprising calcium soap and mineral oil with a weight of 10 and with a weight of 40 and was formulated to meet an ASTM D-1403 penetration of between 265 and 275 worked at P1361-96MX 60 strokes. Both the lithium soap thickener composition of Example 1 and the calcium soap thickener composition of this Example 4 were normalized to the same ASTM D-1403 penetration worked at 60 strokes to provide an appropriate basis for comparison. To the laboratory pot for fat was added approximately 150 gallons of mineral oil with a weight of 40 followed by 320 pounds of hydrated lime and the oil and hydrated lime were agitated until uniform. Once the sample reached a uniform consistency, 870 gallons of mineral oil weighing 40, 300 gallons of mineral oil weighing 10, 2,600 pounds of animal fatty acid, 44 pounds of hydroxide were added to the grease pot. 50 percent sodium in water and 60 pounds of water. The kettle was hermetically sealed under pressure, heated to 270 ° F (132.22 ° C) and maintained at 270 ° F (132.22 ° C) for a period of 1 hour. The mixture was then cooled to 200 ° F (93.33 ° C). Once the kettle temperature reached 200 ° F (93.33 ° C) and the pressure in the kettle reached 0 psig, a sample was removed and acidity or alkalinity was measured in milliequivalents (meq) of calcium hydroxide . Hydrated lime was added to maintain the acidity / alkalinity within a range of between about 0.3 acid and 0.3 alkaline and the reheat and cool sequence was repeated. After P1361-96MX When the appropriate acidity and alkalinity was reached, 30 pounds of water were added to the mixture and the temperature of the mixture was allowed to drop to 180 ° F (82.22 ° C) -185 ° F (85 ° C). C) inside the sealed pot. The kettle was opened and 900 gallons of mineral oil weighing 10 was added and the batch allowed to cool to 140 ° F (60 ° C) -150 ° F (65.56 ° C). The mixture is sampled for water content, acidity / alkalinity and penetration. The mixture had an ASTM D-1403 penetration worked at 60 strokes between 265 and 275, an alkalinity of between 0.1% to 0.28% acid and a water content of approximately 1% by weight. The vacuum was generated in the kettle while it was maintained at a temperature that varied from 140 ° F (60 ° C) -150 ° F (65.56 ° C) for a period of 1 hour. The fat was immediately removed from the kettle. The composition was identified as Fat 8. The drip point worked (ASTM D-2265) at 10,000 strokes of Fat 8 is shown in Table 2 and is plotted in Figure 2.

EXAMPLE 5 Greases 8 and 2 were mixed in the same proportions as Greases 1-7 in order to directly compare the combinations of calcium soap thickeners and thickeners containing urea with the combinations of lithium soap thickeners and thickeners P1361-96MX containing urea according to the present invention Greases 8 and 2 were mixed in mixtures of 1200 passes per roller mill in proportions of 20, 40, 50, 60, and 80 weight of Fat 8 (calcium soap thickener) as a percentage of the total weight of both Greases 8 and 2 (thickener containing urea). These greases were identified respectively as Greases 9, 10, 11, 12 and 13. The drip points (ASTM D-2265) worked at 10,000 strokes of the Greases 9 - 13 are all exposed in Table 2 and are plotted in the Figure 2. Figure 2 includes all drip points ASTM D-2265 at 10,000 strokes for Greases 2 and 8 to 13. Figure 2 also includes the linear regression of the dropping points for Greases 2 and 8 to 13 as a percentage function of Fat 8 compared to the total of Greases 8 and 2 combined. Examples 2, 4 and 5 and Figure 2 clearly illustrate that combining lithium soap thickeners and thickeners containing urea according to the present invention provide surprising and unexpected synergistic advantages at the drip point compared to the point of drip expected from a linear combination of thickeners. Figures 1 and 2 also illustrate that combining thickeners of lithium soap and thickeners containing urea provide a P1361-96MX superior performance and a good cost-benefit ratio compared to fat containing calcium soap thickeners and thickeners containing urea. The beneficial performance range of the calcium / urea-containing soap grease combination of Figure 2 extends from a percentage range of a calcium soap grease to the total of calcium soap plus the one containing urea, about 15 percent to about 55 percent, while the beneficial performance interval of the lithium soap / urea-containing grease combination of Figure 1 extends from about 30 percent to about 95 percent.

TABLE 2 GREASE 8 2 9 10 11 12 13 COMPOSITION OF% FAT IN WEIGHT Fat 8 (Calcium soap) 100 0 20 40 50 60 80 Fat 2 (Containing urea) 0 100 80 60 50 40 20 TESTS Drip point, ° F (° C) (ASTM D-2265) (Block 550 ° F (287.78 ° C)) Worked -10,000 blocks 266 520 516 490 472 300 293 P1361-96MX EXAMPLE 6 For use in the preparation of fat compositions according to the present invention and to identify the effects of adding boric acid to a fat composition according to the present invention, a lithium soap thickener composition was prepared comprising lithium soap and HVl Bright Stock mineral oil. The portion of lithium soap thickener was prepared by adding 6810 grams of HVl Bright Stock mineral oil having a viscosity of 2500 SUS at 37 ° F (37.78 ° C) (Stauffer Chemical Company) in a grease pan and the oil was heated Bright Stock mineral at 170 ° F (76.67 ° C) the hot Brigth Stock mineral oil was combined with 2340.2 grams of methyl 12-hydroxystearate and the mixture was stirred until the methyl 12-hydroxystearate was melted. Approximately 318.4 grams of lithium hydroxide monohydrate and 50 grams of water were added to the mixture and the grease pot was sealed and kept without adding heat for a period of 30 minutes. The mixture was heated to 300 ° F (148.89 ° C) and maintained at a temperature of 300 ° F (148.89 ° C) for a period of 35 minutes. Subsequently, the kettle was ventilated and opened. The batch was then heated to 400 ° F (204.44 ° C) while it was covered with a nitrogen cloud and kept at 400 ° F (204.44 ° C) for 15 minutes. The heat P1361-96MX added to the mixture was reduced in such a way that the temperature of the mixture dropped to 250 ° F (121.11 ° C). Once the mixture reached 250 ° F (121.11 ° C), 2270 grams of additional Bright Stock Oil was added and the mixture was cooled to 150 ° F (65.56 ° C). The composition of lithium soap grease was identified as Fat 14.

EXAMPLE 7 To be used also in the preparation of the fat compositions according to the present invention and to identify the effects of adding boric acid to a fat composition according to the present invention, a thickener base fat composition was prepared. containing urea comprising polyurea and HVl Bright Stock mineral oil. The urea-containing thickener composition was prepared by adding 4086 grams of Bright Stock ore to a grease pot and heating the Bright Stock mineral oil to 175 ° F (79.44 ° C). Once the Bright Stock mineral oil reached 175 ° F (79.44 ° C), 639 grams of Armeen T fatty amine was added to the kettle where it melted and mixed well with the Bright Stock mineral oil. After mixing, approximately 950 grams of water were added and the mixture was mixed for a period of about 5 minutes. The mixture was allowed to cool to a P1361-96MX temperature of 130 ° F (54.44 ° C). Three equal portions of 723 grams of Mondur M, 4,4'-diphenylmethane diisocyanate loading were added to the mixture, the kettle was closed, and the mixture was mixed without heating for a period of about 30 minutes. The mixture was heated to a temperature of about 300 ° F (148.89 ° C), the kettle was vented and opened and the mixture was reheated to a temperature of about 310 ° F (154.44 ° C). Approximately 3064 grams of Bright Stock mineral oil was added to the mixture and the mixture was heated to 400 ° F (204.44 ° C) while the kettle remained open and covered with a cloud of nitrogen. Once the mixture reached 400 ° F (204.44 ° C), the mixture was maintained at a temperature between about 390 ° F (198.89 ° C) -400 ° F (204.44 ° C) for a period of about 15 minutes . The mixture was cooled to 350 ° F (176.67 ° C), after which, 2838 grams of Bright Stock mineral oil were standardized and the mixture was cooled to 175 ° F (79.44 ° C). The fat mixture was milled in a Gaulin mill at 8000 psi. The composition containing urea was identified as Fat 15.

EXAMPLE 8 In order to identify the effects of boric acid in a fat composition in accordance with P1361-96MX present invention, lithium soap thickener and urea-containing thickener compositions further comprising HVl Bright Stock mineral oil and various amounts of boric acid were prepared. The first fat composition was prepared by mixing with a spatula 60.0 grams of Fat 15 (containing urea), 84.0 grams of Fat 14 (lithium soap), 55.8 grams of Bright Stock mineral oil and 0.2 grams of 100 percent boric acid solid. The mixture was passed through the roller mill four times and placed in an oven at 250 ° F (121.11 ° C) for 5 hours. The fat comprised 0.1 weight percent boric acid and was identified as Fat 16. The penetration (ASTM D-1403) of Fat 16 undisturbed, not worked and worked at 60 strokes and the drip point (ASTM D-2265 ) worked at 10,000 strokes are shown in Table 3. The drip point worked at 10,000 strokes is plotted in Figure 3. Fats 17, 18, 19 and 20 were prepared in a similar manner to that described above except that the rate of addition of boric acid was increased to provide fats comprising 0.2, 0.5, 1.0 and 2.0 weight percent boric acid, respectively. The penetration (ASTM D-1403) of Greases 17 to 20, not altered, not worked and worked at 60 strokes and the drip point (ASTM D-2265) worked at 10,000 strokes are exposed in the P1361-96MX Table 3. The drip point worked at 10,000 strokes is shown in Figure 3. Table 3 and Figure 3 clearly illustrate that the lithium soap base / urea-containing grease according to the present invention and containing a critically focused amount of boric acid provides surprising and unexpected advantages in drip point property compared to fats in accordance with the present invention that does not have boric acid in the amounts illustrated. The identified critical range of boric acid is between about 0.1 and 2.0 weight percent, and preferably about 0.2 and 1.2 weight percent for best results.

TABLE 3 GREASE 16 17 18 19 20 COMPOSITION OF% FAT IN WEIGHT Grease 14 (Lithium soap) 84.0 84.0 252.0 84.0 84.0 Fat 15 (Containing urea) 60.0 60.0 180.0 60.0 60.0 Mineral Oil Bright Stock 55.8 55.6 165.0 54.0 52.0 Boric acid 0.2 0.4 3.0 2.0 4.0 THICKNESS COMPOSITION, IN% WEIGHT Polyurea 3.6 3.6 3.6 3.6 3.6 Lithium soap 8.4 8.4 8.4 8.4 8.4 P1361-96MX Boric Acid 0.1 0.2 0.5 1.0 2.0 TOTAL 12.1 12.2 12.5 13.0 15.0 TESTS Penetration, 1/2 scale Not altered 187 201 214 245 295 Not worked 236 242 271 305 359 Worked-60 blocks 265 275 297 343 385 Drip point, ° F (° C) (ASTM D-2265) (Block 550 ° F (287.78 ° C)) Worked-10, 000 blocks 446 461 476 465 442 EXAMPLE 9 A lithium soap-based grease composition containing urea according to the present invention and containing boric acid similar to that described for Fat 18 was prepared using the preparation method set forth in Example 8. Fat 18 it was selected as the base fat to identify the effects of the oven temperature on the mixed fats according to the present invention and which further comprise boric acid. The temperatures of the stove for heating the grease composition were 70 ° F (21.11 ° C), 130 ° F (54.44 ° C), 210 ° F (98.89 ° C), 250 ° F (121.11 ° C), 300 ° F (148.89 ° C) and 350 ° F (176.67 ° C) and fats produced in this way were identified as P1361-96MX Greases 21, 22, 23, 24, 25 and 26, respectively. The penetration (ASTM D-1403) of Greases 21 to 26 not altered, not worked and worked at 60 strokes and the drip point (ASTM D-2265) worked at 10,000 strokes are shown in Table 4. The drip point worked at 10,000 strokes is depicted in Figure 4. Table 4 and Figure 4 clearly illustrate that lithium soap fats containing urea comprising boric acid experience a substantial increase in the rate of drip point improvement at temperatures of the stove in excess of 200 ° F (93.33 ° C) and preferably at stove temperatures in excess of 250 ° F (121.11 ° C) for best results.

TABLE 4 GREASE 21 22 23 24 25 26 THICKNESS COMPOSITION, IN% WEIGHT Pqliurea 3.6 3.6 3.6 3.6 3.6 3.6 Lithium soap 8.4 8.4 8.4 8.4 8.4 8.4 Boric acid 0.5 0.5 0.5 0.5 0.5 0.5 TOTAL 12.5 12.2 12.5 12.5 12.5 12.5 COMPOSITION OF GREASE IN% WEIGHT TESTS Penetration, 1/2 scale P1361-96MX Not altered 283 218 192 197 199 199 Not worked 253 250 237 266 288 289 Worked-60 strokes 258 266 265 292 315 325 Drip point, ° F (° C) (ASTM D-2265) (Block 550 ° F (287.78 ° C)) Worked-10,000 hits 453 460 464 479 488 503 EXAMPLE 10 A product of base fat and lithium and polyurea soap comprising boric acid according to the present invention was prepared. The composition of fat and its various properties are shown in Table 5.

TABLE 5 Percent Weight composition components of weight 12-Methyl Hydroxystearate 7.22 Lithium Hydroxide Monohydrate 1.07 Hooks of Mondur M. 1.60 Armeen TM98 1.40 Corrosion Inhibiting Sulfonate 1.00 Antioxidant of Diphenyl Amine Alkylated 0.75 Anti-wear additive of Triaril Phosphate of 0.90 Alkylated Ester Inhibitor of Corrosion of Amine Borated 2.50 Anti-wear Agent of Alkyl Dithiophosphate 3.00 Zinc Anti-wear agent of Hydrocarbon Sulfide 0.75 Boric acid 0.50 Blue Ink 0.02 Mineral Oil with Weight of 40 64.38 P1361-96MX Mineral Oil with Weight of 10 16.10 Laboratory Analysis ASTM, Units Results Timken, D-2509, pounds 50/60 Penetration, D-217 (Worked at 60 / 100,000) 278/311 Automotive Grease Specification, D-4950-89 GC-LB (pass) (pass / fail) Work Penetration, D217 mm / 10 278 Drip Point, D-2265 ° C, (° F) 258/497 Drip Point, D-566 ° C, (° F) 260+ (500+) Perf. of Low Temperature, D-4693, -40 ° C Nm 7.3 Water Resistance, D-1264, 80 ° C, Percent 7 Oil Separation, D-1742, Percent in 2.4 Mass Classification of Oxidation Protection, pass D-1743 (pass / fail) Diameter of Scar for Wear Protection, 0.44 D-2266mm Life at High Temperature, D-3527 140 Compatibility of Elastomer , D-4289 Change of Volume, in percent 5 Change in Hardness, Durometer A Points -2 Trends to the Fugue, D-4290, gm 7.8 Performance EP 4-Ball, D-2596 Index of Attrition to Load, kgf 51 Welding point, kgf 250 Protection against rubbing, D-4170, loss in mg 4.3 P1361-96MX

Claims (10)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property; 1. A lubricating grease, characterized in that it comprises: a base oil; an additive package, - and a mixed thickener system comprising a thickener containing urea and a lithium soap thickener wherein the lithium soap thickener comprises from about 30% to about 95% of the mixed thickener system, calculated by weight.
2. 2. Lubricating grease according to the claim 1, characterized in that the urea-containing thickener comprises at least one member selected from the group consisting of monourea, diurea and polyurea.
3. The lubricating grease according to claim 1, characterized in that the lithium soap thickener comprises a reaction product of a lithium base material and a monocarboxylic acid and the lithium base material comprises at least one member selected from the group consisting of lithium oxide, lithium carbonate, lithium bicarbonate and lithium hydroxide. P1361-96MX
4. 4. The lubricating grease according to claim 3, characterized in that the monocarboxylic acid comprises at least one member selected from the group consisting of 12-hydroxystearic acid, 14-hydroxystearic acid, 16-hydroxystearic acid, 6-hydroxystearic acid, and 9, 10- dihydroxystearic The lubricating grease according to claim 1, characterized in that the lithium soap thickener comprises lithium 12-hydroxystearate and the urea-containing thickener comprises polyurea. 6. A lubricating grease, characterized in that it comprises: a base oil; an additive package; a mixed thickener system comprising a thickener containing urea and a lithium soap thickener wherein the lithium soap thickener comprises from about 60% to about 90% of the mixed thickener system, calculated by weight; and boric acid in an amount ranging from about 0.1% by weight to about 2.0% by weight calculated as a percentage of the lubricating fat. The lubricating grease according to claim 6, characterized in that the lithium soap thickener comprises a reaction product of a base material of P1361-96MX lithium and a monocarboxylic acid and the lithium base material comprises at least one member selected from the group consisting of lithium oxide, lithium carbonate, lithium bicarbonate and lithium hydroxide and the monocarboxylic acid comprises at least one selected member of the group consisting of 12-hydroxystearic acid, 14-hydroxystearic acid, 16-hydroxystearic acid, 6-hydroxystearic acid, and 9,10-dihydroxystearic acid. - -8 The lubricating grease according to claim 6, characterized in that the lithium soap thickener comprises lithium 12-hydroxystearate and the urea-containing thickener comprises polyurea. 9. Lubricating grease according to the claim 8, characterized in that the boric acid comprises from about 0.2% by weight to about 1.2% by weight of the lubricating grease. 10. Lubricating grease according to the claim 9, characterized in that the lubricating grease is heated up to temperatures in excess of 200 ° F during the preparation of the grease. P1361-96MX