US3868329A

US3868329A - Grease composition

Info

Publication number: US3868329A
Application number: US364853A
Authority: US
Inventors: Stuart Houston Brown; Richard E Crocker
Original assignee: Chevron Research and Technology Co
Current assignee: Chevron USA Inc
Priority date: 1973-04-05
Filing date: 1973-05-29
Publication date: 1975-02-25
Anticipated expiration: 1992-02-25

Abstract

A grease composition is disclosed comprising (a) a lubricating oil base, (b) a mono or polyurea thickener, (c) a Mannich Base prepared by reacting formaldehyde, phenol and an amine selected from diethanolamine, N,N-diethanol alkylenediamine, and diethylamine, and (d) an alkaline earth metal aliphatic monocarboxylate having from 1 to 3 carbons.

Description

United States Patent Brown et a1.

[451 Feb. 25, 1975 GREASE COMPOSITION Inventors: Stuart Houston Brown, San Rafael;

Richard E. Crocker, Novato, both of Calif.

Chevron Research Company, San Francisco, Calif.

Filed: May 29, 1973 Appl. No.: 364,853

Related U.S. Application Data Continuation-impart of Ser. No. 348,399, April 5, 1973.

Assignee:

U.S. Cl 252/17, 252/51.5 R, 252/5l.5 A, 252/392 Int. Cl. C10m 5/20, ClOm 7/32, ClOm 7/30 Field of Search 252/5l.5 R, 51.5 A, 392, 252/17 References Cited UNITED STATES PATENTS 12/1943 Fuller 252/5l.5 R

Primary Examiner-Delbert E. Gantz Assistant Examinerl. Vaughn Attorney, Agent, or FirmG. F. Maagdeburger; C. J. Tonkin; M. D. Nelson [57] ABSTRACT A grease composition is disclosed comprising (a) a lubricating oil base, (b) a mono or polyurea thickener, (c) a Mannich Base prepared by reacting formaldehyde, phenol and an amine selected from diethanolamine, N,N-diethanol alkylenediamine, and diethylamine, and (d) an alkaline earth metal aliphatic monocarboxylate having from 1 to 3 carbons.

12 Claims, No Drawings closed GREASE COMPOSITION CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of US. application Ser. No. 348,399 filed Apr. 5, 1973.

BACKGROUND OF THE INVENTION Modern technology is currently supplying the general public and the process industries with machinery capable of operating under severe conditions. Many of these machines require lubricants having properties which are not available with the conventional greases and oils. Thus modernization of the mechanical devices has strained the petroleum industry for the development of a second generation of lubricants capable of satisfying the lubricating requirements of the new machines.

Recently, a new grease composition has been developed containing a novel polyurea thickening agent. This grease has been found to exhibit superior endurance and high temperature lubricating properties. A particularly advantageous property is that of antithixotropy, i.e., the ability to increase in viscosity with increasing shear. The polyurea thickening agent is disin US. Pat. Nos. 3,243,210; 3,243,372; 3,346,971; and 3,401,027.

While this grease solves many of the problems associated with the older lubricants, it is handicapped by a poor rust inhibition. This is a typical problem associated with most multipurpose grease thickeners. Rusting is a major problem in many machines exposed to a corrosive environment. To combat the rust problems, conventional rust inhibitors have been incorporated into the greases. The conventional inhibitors, however, are quite selective for the particular grease involved and often interfer with the essential properties of the grease. For example, some inhibitors may impart satisfactory rust inhibition but only at the expense of adversely softening the grease. Conversely, some inhibitors may be quite compatible with the grease but are relatively ineffective in rust protection.

It is, therefore, an object of this invention to provide an improved grease composition.

It is an additional object to provide a polyurea grease composition containing a compatible rust inhibitor.

It is another object of this invention to provide a polymer grease having improved rust inhibition.

Other objects and their attendant advantages will become apparent from the following description of the invention and appended claims.

SUMMARY OF THE INVENTION The aforementioned objects can be realizied by incorporating into a mono or polyurea containing grease a minor amount of a Mannich Base prepared by reacting phenol with formaldehyde and an amine selected from the class consisting of diethanolamine, N,N- diethanol alkylenediamine, and diethylamine. The molar ratio of formaldehyde to amine to phenol in the Mannich Base product should preferably be between about 0.55:(l.55:l.

By incorporating this particular Mannich Base into the mono or polyurea grease, the rust inhibition of the grease is significantly increased. Concomitantly, the other physical properties ofthe novel grease are not seriously affected.

DETAILED DESCRIPTION OF THE INVENTION The improved grease composition of the instant in vention can be realized by admixing in a major portion of a lubricating oil, from 0.5 to 20 weight percent of a mono or polyurea thickener and from 0.] to It) weight percent ofa Mannich Base. The Mannich Base is a mixture of compounds prepared by reacting phenol. formaldehyde and an amine. It is believed that a major portion of the compounds have the following generalized structure:

(CHIY):

wherein:

x is an integer from 1 to 4 and preferaby from 1 to Y is a univalent amino radical selected from the group consisting of n is an integer from 1 to 4 and preferably from 2 to The above structural formula represents a broad and simplified version of the Mannich Base useful in the practice of this invention. The product is a mixture of compounds wherein x varies from I to 4. In addition. compounds not described by the above formula may be present, e.g., compounds wherein the hydroxyl unit on the phenolic group enters into a reaction with the formaldehyde or amino co-reactant, etc. Other reactions between the three reactants or any two of them may also take place and the reaction products present in the mixture. Thus, it is apparent that while the above chemical formula is descriptive of the majority of the compounds within the mixture, it should not be interpreted as limiting the invention to the compounds having exact structure as shown. The preferred Mannich Base is prepared by reacting phenol, formaldehyde and diethanol amine.

The compounds are prepard by contacting phenol, formaldehyde and amine in a suitable reactor at a temperature of to 400F and preferably from 200 to 300F under sufficient pressure to maintain the three reactants in liquid phase, generally from 0 to to 150 psig. The contacting is conducted for a period of 0.5 to 25 hours and preferably from 3 to 20 hours. An inert reaction solvent may be employed or the reaction can be conducted with an excess of one or more of the reactants. The solvents, if employed, should preferably be a mutual solvent or posses good solvency for the reactants. Exemplary reaction solvents include aliphatic alcohols having from I to 8 carbons such as isobutyl alcohol, pentanol, isopropyl alcohol, etc.

The amount of reactants charged to the reaction vessel usually varies from 0.5 to molar parts of formaldehyde and from 0.5 to 5 molar parts of amine for each molar part of phenol. The preferred molar ratio varies from 2 to 4.4 parts of formaldehyde and from 2 to 4 parts of amine per part of phenol. Mono or Polyurea Thickening Agent The mono or polyurea thickening agent as employed in this invention is a water and oil-insoluble organic compound having a molecular weight between about 350 and 2,500 AMUs and having at least one ureido group and preferably between about 2 and 6 ureido groups. A ureido group as referred to herein defined as The mono or polyurea compound should preferably have as few terminal primary amine groups, i.e., a compound having a terminal (NH group, as possible and should preferably not have any free carboxylic acid groups. A particularly preferred polyurea compound has an average between 3 and 4 ureido groups and has a molecular weight between about 600 and 1200 AMUs.

The mono or polyurea compounds are prepared by reacting the following components:

I A diisocyanate having the formula: OCN-R-NCO wherein R is a hydrocarbylene having from 2 to 30 carbons and preferably an arylene having from 6 to carbons and more preferably an arylene having 7 carbons;

[I A polyamine having a total of 2 to 40 carbons and having the formula:

R0 R0 R0 H R2 /y H wherein R, and R are the same or different type of hydrocarbylenes having from I to carbons and preferably from 2 to l0 carbons and more preferably from 2 to 4 carbons; R,, is selected from hydrogen or a C,C alkyl and preferably hydrogen; x is an integer from 0 to 2; z is an integer from O to l; and y is an integer equal to 1 when 2 is 0 and 0 when 2 is I.

III A monofunctional compound selected from the group consisting of monoisocyanate having from 1 to carbons, preferably from 10 to 24 carbons, a monoamine having from I to 30 carbons preferably from 10 to 24 carbons, or mixtures thereof.

The reaction can be conducted by contacting the three reactants in a suitable reaction vessel at a temperature between about 60 to 320F, preferably from 100 to 300F, for a period from 0.5 to 5 hours and wherein:

n is an integer from 0 to 3;

R is the same or different hydrocarbyl having from I to 30 carbon atoms, preferably from l0 to 24 carbons;

R is the same or different hydrocarbylene having from 2 to 30 carbon atoms, preferably from 6 to l5 carbons; and

R is the same or different hydrocarbylene having from I to 30 carbon atoms, preferably from 2 to 10 carbons.

As referred to herein, hydrocarbyl is a monovalent organic radical composed of hydrogen and carbon and may be aliphatic, aromatic or alicyclic or combinations thereof, e.g., aralkyl, alkyl, aryl, cycloalkyl, alkylcycloalkyl, etc., and may be saturated or olefinically unsaturated (one or more double bonded carbons, conjugated or nonconjugated). The hydrocarbylene, as defined in R and R above, is a divalent hydrocarbon radical which may be aliphatic, alicyclic, aromatic or combinations thereof, e.g., alkylaryl. a-ralkyl, alkylcycloalkyl, cycloalkylaryl, etc., having its two free valences on different carbon atoms.

The mono or polyureas having the structure presented in Formula I above are prepared by reacting (n+1) mols of diisocyanate with two mols of a monoamine and (n) mols of a diamine. (When n equals zero in the above Formula 1, the diamine is deleted.) Mono or polyureas having the structure presented in Formula 2 above are prepared by reacting (n) mols of a diisocyanate with (n+1) mols of a diamine and two mols of a monoisocyanate. (When n equals zero in the above Formula 2, the diisocyanate is deleted.) Mono or polyureas having the structure presented in Formula 3 above are prepared by reacting (n) mols of a diisocyanate with (n) mols ofa diamine and one mol ofa monoisocyanate and one mol of a monoamine. (When n equals zero in Formula 3, both the diisocyanate and diamine are deleted.)

In preparing the above mono or polyureas, the desired reactants (diisocyanate, monoisocyanate, diamine and monoamine) are admixed within a suitable reaction vessel in the proper proportions. The reaction may proceed without the presence of a catalyst and is initiated by merely contacting the component reactants under conditions conducive for the reaction. Typical reaction temperatures range from 20C to 100C under atmospheric pressure. The reaction itself is exothermic and, accordingly, by initiating the reaction at room temperature, elevated temperatures are obtained. However, external heating or cooling may be desirable.

The mono or polyurea thickener will usually be present in the grease composition at a concentration of0.5 to 20 weight percent and preferably from 3 to weight percent and sufficient to thicken the final composition to the consistency of grease.

Mono or Polyurea Reactants The monoamine or monoisocyanate used in the for mulation of the mono or polyurea will form the terminala end groups. These terminal end groups will have from 1 to 30 carbon atoms, but are preferably from 5 to 28 carbon, and more desirably from 6 to 25 carbon atoms.

Illustrative of various monoamines are pentylamine, hexylamine, heptylamine, octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, eicosylamine, dodecenylamine, hexadecenylamine, octadecenylamine, octadecadienylamine, abietylamine, aniline, toluidine, naphthylamine, cumylamine, bornylamine, fenchylamine, tertiary butyl aniline, hcnzylamine, beta-phenethylamine, etc. Particularly preferred amines are prepared from natural oils or fats or from straight chain acids derived therefrom. These starting materials may be converted to amides by reactions with ammonia and the amides dehydrated to give nitriles. The nitriles are then reduced to give the desired amines. Exemplary amines prepared by the method include stearylamine, laurylamine, palmitylamine, oleylamine, petroselinylamine, linoleylamine, linolenylamine, eleostearylamine, etc. The unsaturated amines are particularly preferred.

Illustrative of monoisocyanates are hexylisocyanates, decylisoeyanate, dodecylisocyanate, tetradecylisocyanate, hexadecylisocyanate, phenylisocyanate, cyclohexylisocyanate, xyleneisocyanate, cumeneisocyanate, abietylisocyanate, cyclooctylisocyanate, etc.

Polyamines, which form internal hydrocarbon bridges between the ureido groups usually contain from 2 to 40 carbon atoms, preferably from 2 to 30 carbon atoms, and more desirably from 2 to 20 carbon atoms. Exemplary polyamines include diamines such as ethylenediamine, propylenediamine, butylenediamine, hexylenediamine, dodecylenediamine, octylenediamine, hcxadecylcnediamine, cyclohexylenediamine, cyclooctylencdiamine, phenylenediamine, tolylenediamine, xylencdiaminc, dianiline methane, ditoluidinemethane, bis(aniline), bis(toluidine), piperazine, etc.

Triamines such as Namino-ethyl piperazine, diethylenetriamine, dipropylene triamine, tert-N-methyldiethylene triamine, etc., and higher polyamines such as triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine, etc.

Representative examples of diisocyanates include hexylenediisocyante, decylenediisocyanate, octadecylenediisocyanate, phenylenediisocyanate, tolylenediisocyanate, bis-(diphenylisocyanate), methylene bis(phenylisocyanate), etc.

Another class of mono or polyurea compounds which may be successfully employed in the practice of this invention include the following:

5 wherein: n is an integer of 1 to 3, R is defined supra;

X and Y are monovalent radicals selected from Table I below.

In the Table, R is defined supra, R is the same as R and defined supra, R is selected from the group consisting of arylene radicals of 6 to 16 carbon atoms and alkenyl groups of 2 to 30 carbon atoms, and R is selected from the grup consisting of .alkyl radicals having from 10 to 30 carbon atoms and aryl radicals having from 6 to 16 carbon atoms.

Mono or polyurea compounds described by the above formula (4) can be described as amides and imides of mono, di, and tri ureas. These materials are formed by reacting in the selected proportions suitable carboxylic acids or internal carboxylic anhydrides, with a diisocyanate and an amine or diamine. The mono or polyurea compounds are prepared by blending the several reactants together in a suitable reaction vessel and heating them to a temperature ranging from F. to 400F. for a period sufficient to cause formation of the compound, generally from 5 minutes to 1 hour.

Suitable carboxylic acids include aliphatic carboxylic acids of about 1 l to 31 carbon atoms and aromatic carboxylic acid of 7 to 17 carbon atoms. Examples of suitable acids include aliphatic acids such as lauric, myristic, palmitic, margaric, stearic, arachidic, behenic, lignoceric acid, etc.; and aromatic acid such as benzoic acid, l-naphthoic acid, Z-naphthoic acid, phenylacetic acid, hydrocinnamic acid, cinnamic acid, mandelic acid, etc. Suitable anhydrides which may be employed are those derived from dibasic acid which form a cyclic anhydride structure, for example, succinic anhydride, maleic anhydride, phthalic anhydride, etc. Substituted anhydrides, such as alkenyl suecinic anhydride of up to 30 carbon atoms are further examples of suitable materials.

Examples of suitable diisocyanates, monoisocyanates, monoamines and diamines are described supra.

The mono or polyurea compounds are generally mixtures of compounds having structures wherein n varies from 0 to 4, or n varies from 1 to 3A, existent within the grease composition at the same time. For example, when a monoamine, a diisocyanate and a diamine are concurrently present within the reaction zone, as in the preparation of ureas having the structure shown in Formula 2, some of the monoamine may react with both sides of the diisocyanate to form a diurea. In addition to the formulation of diurea. simultaneous reactions can be occurring to form the tri, tetra, penta, hexa, octa, etc., ureas. Particularly good results have been realized when the polyurea compound has an average of four ureido groups.

The lubricating oil generally has a viscosity of 35 to 55,000 SUS at 100F and preferably from 20 to 500 SUS at a temperature of 210F.

In a particularly preferred embodiment, an alkaline earth metal aliphatic monocarboxylate is also included within the formulation. By incorporating the metal carboxylate into the grease composition, the total amount of mono or polyurea required to thicken the grease to thedesired consistency can be substantially reduced. 7

Moreover, the presence of the metal carboxylate imparts good extreme pressure properties to the grease.

The alkaline earth metal aliphatic monocarboxylate has from 1 to 3 carbons. Any of the alkaline earth metals can be employed herein, e.g., magnesium, calcium, strontium, barium, etc. However, calcium is the most preferred. The carboxylate group preferably has from 1 to 2 carbon atoms and more preferably 2 carbon atoms. Exemplary compounds which may be successfully employed herein include calcium formate, barium formate, magnesium formate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, calcium proprionate, barium propionate, magnesium propionate, etc.

The amount of alkaline earth metal aliphatic monocarboxylate present within the grease composition may vary depending upon the lubricating property desired, the particular mono or polyurea constituent selected, the type of alkaline earth metal aliphatic monocarboxylate selected, etc. However, generally the metal carboxylate will range from 3 to 30 weight percent of the final grease composition and preferably between about 4 and weight percent. The ratio of alkaline earth metal aliphatic monocarboxylate to the mono or polyurca constituent will also vary depending upon the afore mentioned conditions, but will generally range on a weight basis from 1 to 15 parts of metal carboxylate per part of mono or polyurea and preferably from 3 to 7 parts per part of mono or polyurea.

Preparation of Grease Composition The greases exhibiting superior properties of this invention are preferably prepared by the in situ production of the mono or polyurea within the lubricating oil. In instances where an alkaline earth metal carboxylate is also employed, it may also be prepared in situ. In this embodiment, the lubricating oil is charged to the grease kettle along with the mono or polyurea precursors, i.e.,

the reactants which combine to form the mono or polyurea.

After the formation of the mono or polyurea compounds, the grease kettle is charged with an alkaline earth metal hydroxide or oxide and a carboxylic acid. The ratio of alkaline earth metal hydroxide to carboxylic acid on an equivalent basis can vary from 1 to 4:1 and is preferably between 1 and 2:1. The kettle is maintained at a temperature between 70F and 150F during the process to effect the neutralization reaction of the alkaline earth metal hydroxide or oxide and the carboxylic acid. During the reaction, water is released and is preferably removed from the system by applying a slight vacuum on the kettle of to 29 inches of mercury and heating to about 212F and higher.

The Mannich Base made can then be added to the grease composition to the proper concentration. Generally, from 0.1 to 10 weight percent of-the Mannie Base will be present in the grease composition for best results and more preferably from 0.5 to 2 weight percent.

The grease composition can be further processed by subjecting it to shear hardening. Shear hardening is performed by milling the grease in an extrusion type mill under elevated pressures. This milling improves the dispersion of the mono or polyurea and metal carboxylate throughout the base oil resulting in a grease of greatly improved consistency. US. application Ser. No. 1 11,517 foled Feb. 1, 1971, now abandoned discloses a a preferred method of'shear hardening a grease which can be successfully employed for the composition of this invention. Other Additives In addition to the thickening agents, alkaline earth metal carboxylate and Mannich Base rust inhibitor, other additives may be successfully employed within the grease composition of this invention without affecting its high stability ad performance over a wide temperature scale. One type of additive is an antioxidant or oxidation inhibitor. This type of additive is employed to prevent varnish and sludge formation on metal parts and to inhibit corrosion of alloyed formation on metal parts and to inhibit corrosion of alloyed bearings. Particularly useful grease antioxidants include phenylalpha-naphthyl amine, bis-(alkylphenyl)amine, N,N- diphenyl-p-phenylenediamine, 2,2,4-trimethyldihydroquinoline oligomer, bis(4- isopropylaminophenyl)ether, N-acyl-p-aminophenol, N-acylphenothiazines, N-hydrocarbylamides of ethylenediamine tetraacetic acid, alkylphenolformaldehyde-amine poly condensates, etc.

Another additive which may be incorporated into the grease composition of this invention is an anticorrodant. The anticorrodant is employed to inhibit oxidation so that the formation of acidic bodies is suppressed and to form films over the metal surfaces which decrease the effect of corrosive materials on exposed metallic parts. A particularly effective corrosion inhibitor is sodium nitrite.

Another type of additive which may be employed herein is a metal deactivator. This type of additive is employed to prevent or counteract catalytic effects of metal on oxidation generally by forming catalytically inactive complexes with soluble or insoluble metal ions. Typical metal deactivators include complex organic nitrogen and sulfur-containing compounds such as certain complex amines and sulfides. An exemplary metal deactivator is mercaptobenzothiazole.

In addition to the above, several other grease additives may be employed in the practice of this invention and include stabilizers, tackiness agents, dropping point improvers, lubricating agents, color correctors, odor control agents, etc.

The following examples are presented to illustrate the practice of specific embodiments of this invention and should not be interpreted as imitations upon the scope of the invention.

EXAMPLE 1 This example is presented to illustrate the preparation of a preferred polyurea/alkaline earth metal carboxylate grease. A 48-liter stainless steel reaction vessel equipped with a stirrer is charged with 7,500 grams of a blend of a paraffinic and naphthenic oil having a are stirred for minutes at 130F and thereafter admixed with 6,000 grams ofo base oil and 548 grams of tolylene diisocyanate. The vessel is agitated and held at a temperature of 150 for a 30-minute period.

The vessel contents are thereafter milled in an extrusion type mill at a pressure of 7,500 psi and then heated to 200F. A small sample of the grease is analyzed and trace amounts of diisocyanate are detected. An additional 40 grams of ethylene diamine are charged to the vessel and mixed with the milled grease for a period of 10 minutes at a temperature of 210F. At the end of the 10-minute period, the vessel is cooled to 150F. At the end of the 10-minute period, the vessel is cooled to 150F and 5,000 grams of additional base oil with 2,480 grams of hydrated lime (Ca(OH) are charged to the vessel. The lime and base oil are admixed with the previously milled grease for 5 minutes at which time an additional 5,460 grams of base oil and 2,800 grams of acetic acid are slowly charged to the vessel over a -minute period. The admixture is agitated for minutes at 150F to assure that the neutralization reaction between the calcium hydroxide and acetic acid is complete. Thereafter, an aqueous solution of 320 grams ofa commercial sodium nitrite rust inhibitor is charged to the vessel and the contents milled at 7,500 psi. The grease is heated to 250F to remove water and then cooled to 160F. The grease is then admixed with 8,920 grams of base oil and recycled through a mill at a pressure of 7,500 psi. The product grease has an undisturbed penetration (P of 232 and after 60 strokes a worked penetration (P of 286 (ASTM 217). The ASTM dropping point is about 460F (ASTM-D 2265).

A sample of the grease is calculated to have the following:

wherein T0 is a tall oil radical.

EXAMPLE 2 10 EXAMPLE 3 A 2-liter flask is chargd with 23.5 grams of phenol, 33 grams of formaldehyde. 162 grams of aminopropyl diethanol amine and ml of isobutyl alcohol. The contents are heated to reflux under atmospheric pressure and maintained at those conditions for 20 hours. The solvent is then stripped from the product. The product is analyzed and found to contain 13.9 weight percent nitrogen.

EXAMPLE 4 A 2-liter flask is charged with 23.5 grams of phenol, 33 grams of formaldehyde, 73.1 grams of diethylamine and 125 ml ofisobutyl alcohol. The contents are heated to reflux under atmospheric pressure and maintained at these conditions for 20 hours. The solvent is then stripped from the product. The product had an alkalinity value of 454 mgKOI-l/gram.

EXAMPLE 5 This example is presented to illustrate the effectiveness of the Mannich Bases of this invention as compared to other comparable Mannich Bases. The preparation of the instant Mannich Base is substantially the same as described in Example 2, the reactant having been present in a ratio of 4.4. mols of formaldehyde and 4 mols of diethanol amine for each mol of phenol employed. The Mannich Base is referred to as C H OH/CH O/NH(C H OH) The comparison Mannich Base is prepared substantially as above except that tetrapropenyl phenol is substituted for the phenol above. It was made by reacting 4.4 mols of formaldehyde and 4 mols of diethanol amine for each mol of tetrapropenyl phenol. This base is referred to as Alk- C H OH/CH O/NH(C H OH).

The Mannich Base prepared by Example 3 is referred to as C H OH/CH O/NH-C H N(C H OH) The Mannich Base prepared by Example 4 is referred to as C H OH/CH O/NH(C H Thereafter, varying amounts of the Mannich Bases are incorporated into a grease prepared substantially by the method of Example 1 except containing 3.9 wt percent of the polyurea thickener, 12.9 wt percent of the calcium acetate, about 2 wt percent NaNO and a blend of paraffmic base oils having a viscosity of 55 SSU at 210F.

The following Table 1 illustrates the effect of the Mannich Bases on the hardness of the grease as measured by ASTM D217 (worked penetration). On those greases which were not substantially affected, a modified AASTM D-l743 rust test is performed with 3 percent synthetic sea water (ASTM 665) and 97 percent distilled water. The rust test rating; is 0 no rust and 5 very rusty with intermediate values between 0 and 5 representing increasing degrees of rust. This rating system is more fully described in IR 220 (British Institute of Petroleum) and is sometimes called the Emcor rating system. Ratings are determined after the bearing is stored for 1 day at 77F.

TABLE 1 Properties of Mono or Polyurea Grease TABLE l-Continued Properties of Mono or Polyurea Grease Worked ASTM Content Pen. Rust Ex. Type of Additive (wt /r) (P Rating 3 same 2.5 313 4 AIk-C H OHICH OINH- (C H,OH) S 439 5. same 25 439 6 C H OH/CH O/NH C;,H,;N-

C,H,0H) 294 0 7 C H OH/CH O/NH(C H l 290 0 8 C.,H OH/CH O/NH,C H OH* l 296 3 *Prepared by the steps recited in Ex. 2 except substituting ethanol amine for the diethanol amine.

The above table clearly illustrates the superiority of the Mannich Base of the present invention over the comparable Mannich Bases. As shown, in Experiments 2 and 3 (employing a Mannich Base of the instant invention), the additive slightly hardened the grease from 319 to 311 or 313 whereas in Experiments 4 and 5, the

additive significantly defeated the thickening action of the polyurea by softening the grease to a penetration of 439.

The above table also illustrates the excellent rust inhibition from using the claimed Mannich Bases over a close homolog (comparison of Experiments 2, 3, 6 and 7 with Experiment 8).

EXAMPLE 6 This example is presented to illustrate the breadth of the instant Mannich Bases and the effectiveness of these various bases in reducing rust while not substantially interfering with the physical properties of the grease. The Mannich Bases are prepared in substantially the same manner as described in Example 2. The molar ratio of the various reactants are varied.

The Mannich Bases are incorporated into a polyurea grease prepared by the method of Example 1 except containing 3.9 wt percent of the polyurea thickener and 13.9 wt percent of the calcium acetate and a blend of paraffinic base oils having a viscosity of 55 SSU at 210F.

The ASTM worked penetration and the ASTM rust rating of the greases are measured and reported in the following Table II.

TABLE II Effect of Mannich Base on Mono or Polyurea Grease Mannich Base Additive Molar ratio of phenol to formaldehyde to diethanol amine in reaction product.

We claim: 1. A grease composition comprising a major portion of an oil of lubricating viscosity, (1) from 0.5 to 20 weight percent of a water and oil-insoluble mono or polyurea thickening agent having at least one ureido group and having a molecular weight between about 350 and 2,500, (2) from 3 to 30 weight percent of an alkaline earth metal aliphatic monocarboxylate having from 1 to 3 carbons, and (3) from 0.1 to 10 weight percent of a Mannich Base prepared by reacting phenol with formaldehyde and an amine selected from the class consisting of diethanolamine, N,N-diethanol alkylenediamine and diethylamine, the molar ratio of formaldehyde to amine to phenol being between about 0.5 and 5:0.5 and 5:1.

2. The grease composition defined in claim 1 wherein i ..NlNrd anal. l m n a t sfatmti wherein n is an integer from 1 to 4.

3. The grease composition defined in claim 1 wherein said Mannich Base is prepared by reacting between 2 and 4.4 molar parts of formaldehyde with between 2 and 4 molar parts of said amine for each part of said phenol.

4. The grease composition defined in claim 3 wherein said amine is diethanolamine.

5. A grease composition comprising l a major portion of an oil of lubricating viscosity, (2) from 3 to 30 weight percent of an alkaline earth metal aliphatic monocarboxylate having from 1 to 3 carbons, (3) from 0.5 to 20 weight percent of a mono or polyurea thickener prepared by reacting a. a diisocyanate having the formula OCN-R-NCO R0 R0 Elias teat at wherein R, is selected from the group consisting of hydrogen, a C -C alkyl or mixtures thereof;

R and R are the same or different type of hydrocarbylene having from 1 to 20 carbons; x is an integer from 0 to 2; z is an integer from 0 to l; and y is an integer equal to 1 when 2 is 0 and 0 when 2 is c. a monofunctional compound selected from the group consisting of C -C monoisocyanate, C -C monoamines or mixtures thereof; and (4) from 0.1 to 10 weight percent of a Mannich Base prepared by reacting phenol with formaldehyde and an amine selected from the class consisting of diethanolamine, N,N-diethanol alkylenediamine and diethylamine, the molar ratio of formaldehyde to amine to phenol being between about 0.5 and 520.5 and 5:1. 6. The grease composition defined in claim 5 wherein said diisocyanate is tolylene diisocyanate, said polydiethanol amine with each molar part of said phenol.

10. The grease composition defined in claim 5 wherein said alkaline earth metal aliphatic monocarboxylate is calcium or barium acetate.

11., The grease composition defined in claim 1 wherein said alkaline earth metal aliphatic monocarboxylate is calcium acetate.

12. The grease composition defined in claim 10 wherein said alkaline earth metal aliphatic monocarboxylate is calcium acetate.

Claims

1. A GREASE COMPOSITION COMPRISING A MAJOR PORTION OF AN OIL OF LUBRICATING VISCOSITY, (1) FROM 0.5 TO 20 WEIGHT PERCENT OF A WATER AND OIL-INSOLUBLE MONO OR POLYUREA THICKENING AGENT HAVING AT LEAST ONE UREIDO GROUP AND HAVING A MOLECULAR WEIGHT BETWEEN ABOUT 350 AND 2,500, (2) FROM 3 TO 30 WEIGHT PERCENT OF AN ALKALINE EARTH METAL ALIPHATIC MONOCARBOXYLATE HAVING FROM 1 TO 3 CARBONS, AND (3) FROM 0.1 TO 10 WEIGHT PERCENT OF A MANNICH BASE PREPARED BY REACTING PHENOL WITH FORMALDEHYYDE AND AN AMINE SELECTED FROM THE CLASS CONSISTING OF DIETHANOLAMINE, N,N-DIETHANOL ALKYLENEDIAMINE AND DIETHYYLAMINE, THE MOLAR RATIO FO FORMALDIAMINE AND DIETHYBEING BETWEEN ABOUT 0.5 AND 5:0.5 AND 5*1.

2. The grease composition defined in claim 1 wherein said N,N-diethanol alkylenediamine has the formula:

5. A grease composition comprising (1) a major portion of an oil of lubricating viscosity, (2) from 3 to 30 weight percent of an alkaline earth metal aliphatic monocarboxylate having from 1 to 3 carbons, (3) from 0.5 to 20 weight percent of a mono or polyurea thickener prepared by reacting a. a diisocyanate having the formula OCN-R-NCO wherein R is a hydrocarbylene having from 2 to 30 carbons; b. a polyamine having the formula

6. The grease composition defined in claim 5 wherein said diisocyanate is tolylene diisocyanate, said polyamine is ethylene diamine and said monofunctional compound is a C10 to C24 monoamine.

7. The grease composition defined in claim 6 wherein 2 molar parts of said diisocyanate are reacted with 1 molar part of said polyamine and 2 molar parts of said monoamine.

8. The grease composition defined in claim 7 wherein said amine is diethanolamine.

9. The grease composition defined in claim 7 wherein the Mannich Base is prepared by reacting 2 to 4.4 molar parts of formaldehyde and 2 to 4 molar parts of diethanol amine with each molar part of said phenol.

10. The grease composition defined in claim 5 wherein said alkaline earth metal aliphatic monocarboxylate is calcium or barium acetate. 11., The grease composition defined in claim 1 wherein said alkaline earth metal aliphatic monocarboxylate is calcium acetate.