US2790767A - Grease compositions containing complex alkaline earth metal salts - Google Patents

Description

Patented Apr. 30, 1957 GREASE COMPOSITIONS CONTAINING COMPLEX ALKALINE EARTH 'METAL .SALTS John J. Giammaria, Woodbury, N. J., assignor to Socony Mobil-Oil Company, Inc., a corporation or New York No Drawing. Application October 30, 1956, Serial No. 619,123

The present invention is concerned with grease compositions. More specifically, the invention is concerned with grease compositions containing novel gelling agents,

namely, complex alkaline earth metal salts of acetic acid and of partial esters of phosphoric acid.

This application is a continuation-in-part of application Serial No. 354,406, filed May 11, 1953, now abandoned.

Recently developed for use as mineral lubricating oil detergents are oil-soluble, complex metal salts of organic acids such as formic, acetic and caproic acids and of partial esters of phosphoric acid. These salts and lubrieating oil compositions containing the same are described by Ferdinand P. Otto in applications Serial Nos. 246,501, filed September 13, 1951 (now abandoned) and 541,849, filed October 22, 1955; and related zinc salts are described by Ferdinand P. Otto and Edmund W. Flynn in applications Serial Nos. 246,502, filed September 13, 1951 (now abandoned), and 541,848, filed October 22, 1955.

I have now found that, while the complex metal salts described in the aforesaid applications are excellent additives for lubricating oils, they are not suitable for use as gelling agents for greases. This is particularly so for greases subjected to high temperatures during use. However, I have now discovered a related class of novel complex metal salts which are gelling agents of excellent character and particularly eifective for high temperature greases. It is with such agents that this invention is concerned.

It is well known that greases lose some .or all of their effectiveness when subjected to high temperature operations. In lubricating machine parts, for example, it is essential that a grease retain its gel structure during use; failure to do so results in high consumption of the grease and frequent servicing. In general, available greases suffer from a marked tendency to change in character when used over a wide range of temperature, particularly at high temperatures of the order of 300-500 F. and higher. Some conventional greases are characterized by excessive softening when exposed to such high temperature operation, thereby extruded too rapidly from the area being lubricated to provide .efiicient lubrication.

It is an object of this invention, therefore, to provide a grease effective .for .high temperature use, such as 200- 500 F. and higher. A further object is .to provide a grease which retains its original character over a wide 'range of operating conditions. Another object is to pro vide a novel group or class of gelling agents. Other objects of the invention will be apparent from the following description.

The gelling agents of this invention can be designated broadly as complex metal salts of partial esters of phosphoric acid and of acetic acid. The nature of these salts is unknown at this time and, therefore, no exact chemical formula can be ascribed to them. They can best be described by the process for producing them.

The complex metal salts are prepared by first preparing a partial ester of phosphoric acid by the reaction of phosphorus pentoxide with an alkyl-substituted hydroxyaromatic compound in which the alkyl portion contains from eight to fourteen carbon atoms, preferably nine to twelve carbon atoms. The ester is then reacted by either of three methods, viz.,

(1) Reacting a mixture of the ester and acetic acid with an alkaline earth metal hydroxide or oxide,

(2) Reacting the ester with a salt of an alkaline earth metal to form the normal metal salt of the partial ester and then further reacting the normal metal salt with an alkaline earth metal acetate, or

(3) Reacting the ester with a sufficient amount of alkaline earth metal acetate to provide the complex salt (i. e., without intermediary formation of the normal salt).

In accordance with method (2), the metal salt reagent used to form the normal salt need not be a carboxylate salt, but can be a hydroxide, carbonate or an alcoholate. However, the metal constituent of both salt reagents, i. e., the one utilized in forming the normal salt and the complex ,salt is preferably the same metal, and the latter salt reagent is preferably an acetate.

In each of the aforesaid methods, (1) through (3), a temperature of at least about 400 F., and preferably 400500 F., is employed. The heating period is generally from about 0.1 to about 2 hours. However, a preferred procedure involves preparation of the desired complex metal salts in .oil. In the preferred procedure, the partial esters and acetic acid are blended with suiticient mineral oil to give 15 to 25 percent of the desired complex .salt in the finished grease. An alkaline earth hydroxide, in .an amount sufficient to at least neutralize all the acids employed, is then added and the resulting mixture is heated to 400-500 F. to form the grease. The grease is cooled statically or with stirring, and is milled to a smooth consistency.

As indicated above, in View of the complex nature of the reactions involved in the formation of the complex metal salts, theirexact structure is not yet known. The complexity .of these salts is indicated by the complexity of the esters from which they are prepared.

When an alkylated hydroxyaromatic compound, such as an alkyl phenol is reacted with phosphorous pentoxide in a 3:1 mol ratio, indications are that the product consists essentially of a mixture of:

p 1) Mono-alkaryl phosphoric acids (2) Di-alkaryl phosphoric acid and (3) pyrophosphoric acids such as di-alkaryl pryo phoric acid (EH OH R--.01|TO1TOR in the mixture is increased.

Alkyl hydroxyaromatic compounds suitable for preparing the partial esters contemplated herein can be represented by the general formula:

wherein A is an aromatic nucleus or group such as phenyl. naphthyl, etc.; R is an alkyl. group containing from eight to fourteen carbon atoms, and is preferably i of branched-chain configuration; and n is a small whole number from one to two, preferably one. Preferred of such compounds are alkyl phenols having from nine to twelve carbon atoms in the alkyl group. Nonylphenol is especially preferred.

As is well known in the art, such alkylhydroxyaromatic compounds can be prepared by alkylation of a hydroxyaromatic compound, such as phenol. Alkylation of the aryl hydroxide can be accomplished by methods such as a Friedel-Crafts synthesis using a halogenated compound. Alkylation can also be effected by reaction of the aryl hydroxide with unsaturated hydrocarbons, or alcohols, in the presence of a suitable catalyst, such as H2504, ZnClz, BFs, HF, etc.

Typical aryl hydroxides or phenols which may be used as the starting material for the alkylation reaction are: phenol, resorcinol, hydroquinone, catechol, crcsol, xylenol, hydroxydiphenol, benzylphenol, phenyl-ethyl-phe nol, phenol resins, methyl-hydroxydiphenyl, guaiacol, alpha and beta naphthol. alpha and beta methyl naphthol, tolyl naphthol, xylyl naphthol, benzyl naphthol, anthranol, phenyl methyl naphthol, phenanthrol, chlorphenol and the like. Preference is given to phenol.

In preparing the alkaryl phosphoric acid ester, the alkyl hydroxyaromatic compound and P205 are heated together at a temperature of from about 50 C. (122 F.) to about 150 C. (302 F.) for a period of time to insure substantially complete reaction, usually from about five to fifteen hours. An inert solvent, such as toluene, xylene or the like, can be used to facilitate the reaction. A mineral oil can also be used as the solvent, in which case the product is an oil concentrate which can be used directly in the preparation of the complex metal salt and ultimately in the preparation of the desired gelling agent. In this way the ultimate gelling agent is obtained in the form of an oil concentrate and can be conveniently utilized as such for preparation of greases. When a solvent other than mineral oil is used, the P205 reaction mixture is filtered and topped at elevated temperature and reduced pressure to remove the solvent.

The proportions of alkyl hydroxyaromatic compound and P205 used in the reaction can be varied between from about one to about three mols of the alkyl hydroxyaromatic compound to one mol of P205. In general, the use of a 2:1 ratio yields a complex salt with acetic acid which has greater gelling power.

As indicated previously, in preparing the complex metal salt of the phosphoric acid ester, the normal salt can be prepared first by reaction of the ester with a suitable metal salt, such as a hydroxide, carbonate, alcoholate, etc. The complex salt can then be formed by further reaction of the normal salt with an alkaline earth metal acetate, preferably of the same metal constituent as the metal salt reagent used in the formation of the normal ester salt. Also, the complex salt can be prepared directly by reacting the ester with a sufficient amount of an alkaline earth metal acetate salt to provide twice the amount of metal which would be equivalent to the acid-hydrogen content of the phosphoric acid partial ester. However, the most advantageous method involves reacting a mixture of acetic acid and partial ester product with an alkaline earth metal hydroxide, wherein the hydroxide is used in an amount at least suflicient to neutralize the acetic acid and partial ester product.

4 The proportions of esterand acetic acid to be used in preparing the gelling agents can be varied over a fairly wide range. In general, it is preferred to use an amount '4 of acetic acid equivalent to the ester on the basis of neutralization number. The amount of acetic acid can be reduced to about fifty percent of this amount, but increasing it much above the equivalent amount results in the formation of greases which are excessively fluid and which are unsatisfactory for high temperature use.

The reactions required to produce the complex salts by any one of the methods recited above, are within the skill of those familiar with the art. The reactions are accomplished at temperatures of from about 400 F. to about 500 F., in a relatively short time, generally from about 0.1 hour to 2 hours. A suitable solvent medium, such as benzene, toluene, xylene and the like, or a min eral oil can be used as the solvent. In the latter case, an oil concentrate of the complex salt is obtained.

The preferred method, however, involves preparation of the desired complex metal salts in oil. The partial esters and acetic acid are blended with sufficient mineral oil to give 15 to 25 percent of the desired complex salt in the finished grease. An alkaline earth metal salt reagent in an amount sufficient to at least neutralize all the acids employed, is then added and the resulting mixture is heated to 400-500 F. to form the grease. The grease is cooled statically or with stirring, and is milled to a smooth consistency.

Alkaline earth metals are employed in forming the gelling agents of this invention, particularly calcium and barium. Calcium is preferred in view of its lower cost. The hydroxides are preferred for neutralizing the mixture of alkaryl phosphoric and acetic acids to form the gelling agents.

Several illustrative but non-limiting examples of some specific gelling agents and greases containing the same are set forth below. In the examples, all parts are by weight unless otherwise described.

EXAMPLE I Calcium grease 0f nonylphclzol-PzOs product (3 :1 ratio) and acetic acid A nonylphenol-PzOs product was prepared by adding 0.33 molar proportion of P205 in small portions to 1.0 molar proportion of nonylphenol at 200 F., while mechanically stirring the mixture which formed. After the addition of P205 was completed, the temperature was raised to 300 F. and was so maintained for about three hours. The viscous product was then filtered through a thin layer of filtering clay (Hy-flo clay) on a heated Buchner funnel. The product-the filtratehad a neutralization number of 195, and contained 7.6 percent of phosphorus.

Five parts of this product, one part of glacial acetic acid, 1.4 parts of Ca(OH)2 and 20 parts of a solvent refined naphthenic oil having a viscosity of 513.5 SUS (Say' bolt Universal seconds) at F., were mixed and were heated with constant stirring. The resultant mixture began to thicken at 410 F. and formed a heavy gel at 420 F. The mass was stirred while it was cooled to room temperature, after which the heavy grainy gel which resulted was milled to a smooth consistency.

EXAMPLE lI Calcium grease of nonylphenol-PzOs product (3:1 ratio) and acetic acid This grease was prepared by the procedure described in Example 1 above, except that the proportions of reactants were increased twenty-fold. The heavy grease so obtained was blended with additional mineral oil parts) to reduce the soap content to twenty percent (weight). This blend was put through a colloid mill. The final grease had a buttery consistency.

EXAMPLE III Calcium grease of nonylphenol-PzOs product (3:1 ratio) and acetic acid One hundred parts of a nonylphenol-PzOs product similar to that which is described in Example I, above, ten parts of glacial acetic acid (fifty percent of the amount used in Examples I and II), twenty-two parts of Ca(OH)2 and four hundred parts of a solvent refined naphthenic oil having a viscosity of 513.5 SUS at 100 F., were mixed in a grease kettle and heated. A temperature of about 500 F. was required to form a gel. Heating was continued for about five minutes after the gel had formed. The product was then cooled to room temperature (about 75 F.) while it was stirred. The resulting grease was quite heavy in consistency and dark in color.

EXAMPLE IV Calcium grease of nonylphenol-PzOs product (3:1 ratio) and acetic acid This grease was prepared in the same manner as the grease of Example III, except that twenty-five parts of glacial acetic acid and thirty-one parts of Ca(OI-I)z were used. In this case, gelation occurred at about 415 F.

EXAMPLE V Calcium grease of nortylphenol-PzOs product (2:1 ratio) and acetic acid A nonylphenol-PzOs product was prepared in the same manner as the corresponding product described. above in Example I; however, here, 0.5 molar proportion of P205 was used per molar proportion of nonylphenol. The product so obtained had a neutralization number of 207 and was considerably more viscous than the product pre pared with a 3:1 ratio.

One hundred parts of the 2:1 product, 22.2 parts of glacial acetic acid, 30.0 parts of Ca(OH) 2, and 400.0 parts of a solvent refined naphthenic oil having a viscosity of 513.5 SUS at 100 F., were charged to a grease kettle and were heated. Gelation occurred at about 425 F.

EXAMPLE VI Barium grease of nonylphenol-PzOs product (3:1 ratio) and acetic acid cooled to about 75 F. and was put through a. colloid mill.

The resulting grease was smooth and: of heavy consistency.

EXAMPLE Vll Calcium grease of dodecylphenoi-Pzos product (3:1 ratio) and ace-tic acid A dodecylphenol-PzOs product was prepared in the manner described in Example I, above. The neutralization number of the product so obtained was 170'.

One hundred parts. of. this dodecylpheno -P2Q5 product,

1717 parts of glacial acetic acid, 25.0 parts of a(OH )z"- and 400.0 parts of solvent refined naphthenic. oil having a viscosity of 5,1 3.5 SUS atv 100 F, were charged to a grease kettle and were heated to. 445 F. during a period of 1-2 hours, whereupon gelation occurred. After heating the mixture for about ten minutes at 445 F., the resulting heavy grease was cooled toroom temperature (about 75 F.) while it was stirred. The grease was, blended with 100 parts. of the. oil described above. and a.

rather soft,v adhesive grease was formed- EXAMPLE VIII Calcium grease of tetradecylphenol-PzOs product (3:1 ratio) and acetic acid A tetradecylphenol-PzOs product was prepared by the procedure described in Example I, above. The product so prepared had a neutralization number of 150.

One hundred parts of this tetradecylphenol-PzO product, 16.1 parts of glacial acetic acid, 22.0 parts of Ca(OH)z and 375.0 parts of solvent refined naphthenic oil having a viscosity of 513.5 SUS at 100 F. were charged to a grease kettle and were heated to about 470 F. during a period of 1-2 hours, whereupon gelation occurred. The mixttu'e was heated at about 470 F. for about five minutes, then the grease was cooled to room temperature (about F.) while it was stirred.

EXAMPLE IX Calcium grease from n uylphenol-P2O5 product (2:1 ratio) and excess calciun'z acetate A mixture of parts of nonylphenol-PzOs product (described in. Example V), 6.5 parts of calcium acetate and 40.0 parts of a solvent refined naphthenic oil having a viscosity of 5l3.5- SUS at 100 F, was heated with stirring. Foaming occurred between 200 and 400 F. Foamsubsided at 400 F. and the mixture was very fluid. It became more viscous at MO-450 F. and set to a coarse, grainy gel. It was cooled to room temperature and milled to a fairly smooth grease.

EXAMPLE X Calcium grease from the calct'zmt salt 0 nonylphenol- P205 product (2:1 ratio) and calcium acetate A mixture of 10.0 parts of nonylphenol-PzOs product (described in Example V), 1.37 parts of Ca(OH.)z and 40.0 parts of oil (as in Example 1.), was heated with stirring to 350 F. to form the calcium salt of the partial ester of phosphoric acid. This was cooled to F. and 325 parts of calcium acetate were added. The mixture was reheated with stirring. It remained fluid up to 450 F. It began to thicken at this point and form a soft, grainy gel at 450-460 P. On cooling to room temperature, it was milled to a fairly smooth, somewhat softer greasethan Example IX.

In general, the. greases of this invention are characterized by high dropping points, which fact indicates their use for high temperature applications. The dropping points and penetration values, of the greases described above are listed in Table I below.

TABLE I A. S. '1. MA A. S. l.. M?

Grease Penetration, Dropping IIlIIL/lO Point, F.

Example I 450 Example II. 290 440 Example III. 285 460 Example IV. 320 410 Example. V. 460 Example VI 225 340 Example VII 1 345 485 Example VIII '360 135 1 A. S. '1. M. Designation 1) 217-48. 'A. S. T. M. Designation D 560-42.

The data presented in Table I reveals that the greases illustrative of the invention are suitable for high temperature applications. In contrast, the grease of Example VII-I, derived from tetradecylphenol, has an unsatisfactory dropping point value, as low as 135 F, and has a rather high penetration value (360). These unsatisfactory characteristics are ascribed, in part at least, to the excessive length of the alkyl chain, tetrad'ecyl of the alkylphenol. As indicated above, the maximum number of carbon atoms in said alkyl chain is preferably about twelve.

illustrative Examples I through VIII are presented'in TABLE II paratus employed is described in the Institute Spokesman, 6, No. 12, page 4, March 1943. The procedure followed in this test is given below:

1. Work 99 grams of grease and 1 cc. of distilled water Greases of alkaline earth metal c mplexes of alkylphenol- P205 products and acetic acid I Reactants (Parts by Wt.) Properties of Grease Example No. Gelation Alkylphenol-P O Acetic Metal Temp, F. A. S. T. M. A. S. T. M.

Product Acid Hydroxide Oil Penetration, Dropping mun/l0 Point, F.

23 30 (Ga)... 400 22 (Ca)... 400 I5 26 (Ga)... 5

20 28 (Ga)... 500 22.2 30 (0a).... 400 31 (0a).... 400 100 (C (Ca)... 400 100 (Cu n. 40 (C11)... 400 100 (Cu) 20 110 833).. 400 100 (C -Diumyl)... 17. 7 25 a). 400 100 (Cu) 17.7 25 (Ga)..- 500 16.1 22 (0a)--.- 875 ll. 0 15 (Ca). 400 13.3 20 (0a).. 400

1 Ratio of Alkylphenol to P O; ls (3:1) in all cases except No. V which is (2:1). Alkyi group in Alkylphenol ts branched in all cases except N o. XIV

A number of observations can be made from the data I set forth in Table II. Examples I-V and XVII involve a nonylphenol-PzOs product, and all greases derived therefrom are of excellent character. Thus, a nonyl alkyl group and the nonylphenol-PzOs product are preferred. In contrast, the octylphenol-PzOa product (Example XVI) failed to form a grease. Diamyl phenol (Example XIII), tetradecylphenol (Example VIII), pentadecyl phenol (Example XIV), and wax phenol (Example XV), either failed to yield a grease or the grease was unsatisfactory in that it was too soft in consistency.

Examples I-V and XI, XII and XVII illustrate the effect of varying the amount of acetic acid on the calcium base grease. The use of 15 to 25 parts of acetic acid to 100 parts of the nonylphenol-Pzos product, is preferred since greases of good consistency and high dropping points are formed at the lower temperatures, 415- 435 F. When the amount of acetic acid was reduced to 10 parts (Example III), a temperature of 500 F. was required to form the grease, while 30 to 40 parts of acetic acid (Examples XI and XII) failed to yield a grease.

A comparison of Example V with Example IV, indi- -on a glass plate with a spatula until the droplets of water disappear into grease.

2. Transfer the wet grease to a 3 ounce asphalt tin and cool the sample to 77 F.

3. Scrape off the excess grease from the top of the tin with the blade of the spatula and determine the penetration of the grease, using the micropenetration cone and shaft assembly (weight 58.3 grams).

4. Charge the rolling stability test cylinder with grams of the wet grease and distribute the grease uniformly on the inside walls of the cylinder. Place the Weighted roll in the cylinder and screw the cylinder cap on tightly.

5. The grease is worked in the cylinder at room temperature for a period of 2 hours.

6. At the end of the rolling time period, disassemble the apparatus. Remove the rolled grease from the cylinder and roller with a spatula and transfer the grease to a 3 ounce tin for penetration measurement. Cool therol-led grease to 77 F. within 15 minutes and determine the micropenetration.

The .description of the equipment used in determining oil separation, subsequent to the rolling stability test, is describedin the Institute Spokesman, volume XI, No. 7, pages 4-5, October 1947, r

. Results of this severe test are shown in Table III below:

cates that the use of a 2:1 ratio (Example V) of alkylphenol to P205 instead of a 3:1 ratio, is responsible for a grease of heavier consistency.

Calcium is the preferred metal, since barium (Example VI) lields a grease of much lower dropping point, although still in the range suitable for a high temperature grease.

To further illustrate the excellent character of the instant gelling agents and greases containing the same, grease II shown above in Table II was subjected to a severe test. The grease was evaluated for shear stability in the presence of water The rolling stabilitytest ap- Grease II, therefore, was satisfactory in all respects in this test.

In summary, it can be stated that the preferred gelling agent of this invention is the complex calcium salt of a mixture of nonylphenolP2O5 acid product (2:1 ra-: tio or 3:1 ratio) and acetic'acid in which approximately equivalent amounts of the two acids are used based on neutralization number, and in which the acids are reacted with calcium hydroxide in an amount at least sulficient to neutralize the acids, said gelling agent being formed at a temperature of 400-450 F. in the presence of mineral oil. The amountof gelling agent. to be used informing a grease can vary from about ten percent to about fifty percent. In general, fifteen to twenty-five percent is a suitable concentration.

OIL VEHICLES The oil vehicles or oleaginous vehicles of the greases of this invention can vary considerably in character. In general, mineral oils used are those characterized by a viscosity (S. U. S.) of greater than about 40 seconds at 100 5., preferably from about 60 to about 6000 seconds at 100 F. In place of all or part of the mineral oil component, other oils of lubricating viscosity can also be used. Such oils include synthetic vehicles compris ing polymerized olefins, esters of aliphatic dibasic acids, esters of polyalcohols and monocarboxylic acids, silicones, silicate esters, esters of phosphorus-containing acids, fluorocarbons, etc. Typical of such synthetic oils are: polypropylene, polypropylene glycol, di(-2-ethyl hexyl) sebacate, phthalate, polyethylene glycol di(-2-ethy-1 hexoate), polymethylsiloxane. The synthetic vehicles are most: suitable for providing greases for use in aircraft, since many of such greases require lubricating value over a temperature range, from about -l F. to about 500 F.

MODIFYING AGENTS it is to be understood that the greases of this invention can also contain other characterizing materials and fillers. For example, the greases can contain anti-oxidants such as amines (e. g, phenyl alpha-naphthylamine), phenols (e. -g., 2-6-di-tertiary butyl-4-methyl phenol), and the like; lubricity improving agents such as firee fiat, free fatty acids, esters of alkyl and/0r aryl acids, sulfurized iats, lead soaps, etc. Typical fillers include carbon black, silica flour and colloidal clay. Other additives which can be. present are: extreme pressure agents, such as a chloro naphtha xanthate; and tackiness agents such as poly-isobutylenes.

UTILITY The greases of this invention are suitable for a wide range of industrial applications. Some, for example, are suitable for use as multipurpose automotive greases, serving as chassis, wheel-bearing, water-pump grease lubricants. Others are multi-purpose industrial greases serving as plain-bearing land anti-friction greases for normally loaded and heavily loaded equipment. In general, then, greases contemplated herein range from semi-fluid types suitable as textile machinery lubricants, to solid block type greases used in lubrication of machinery in steel mills, paper mills, cement mills, etc.

I claim:

1. A grease comprising an oleaginous lubricant and a gelling agent in an amount suflicient to thicken said vehicle to form a grease, said gelling agent being prepared by the steps of: (1) reacting one molar proportion of phosphorus pentoxi'de with from about one to about three molar proportions of an alkyl hydroxyarom-atic compound of the general formula RA(OH)n wherein R is an alkyl group containing from eight to fourteen carbon atoms, 11 is a small Whole number from one to two, and A is an aromatic nucleus, to form an acidic, partial ester of phosphoric acid, and (2) forming a mixture of the acidic, partial ester obtained by step (1) and a quantity of acetic acid from about fifty percent to about one hundred percent equivalent to said lacidic, partial ester on the basis of neutralization number, and (3) reacting the mixture formed in step (2) with an alkaline earth metal compound selected from the group consisting of an oxide and a hydroxide, at a temperature between about 400 F. and about 500 F., the amount of said metal compound being at least sufiicient to neutralize the acetic acid and the acidic, partial ester.

2. A grease comprising an oleaginous lubricant and a di,(-2v-ethyl hexyl). adipate, dibutyl gelling agent, in an amount suflicient to thicken said vehicle to form a grease, said gelling agent being prepared by the steps of: (1) reacting one molar proportion of phosphorus pentoxide with inom about one to about three molar proportions of an alkyl hydroxyarcmatic compound of the general formula R-A(OH )n wherein R is an alkyl group containing from eight to fourteen carbon atoms, n is a small whole number from one to two, and A is an aromatic nucleus, to form an acidic, partial ester of phosphoric acid, and (2) reacting the acidic, partial ester of step (1) with a quantity of an alkaline earth metal salt to form the corresponding normal metal salt of said acidic, partial ester, and (3) reacting the said normal metal salt with an alkaline earth metal acetate at a tempenature between about 400 F. and about 500 F.

' A is an aromatic nucleus, to form an acidic, partial ester of phosphoric acid, and (2) reacting the acidic, partial ester of step (1) with an alkaline earth metal acetate at a temperature between about 400 F. and about 500 F., the amount of said acetate being sufficient to provide twice the amount of alkaline earth metal equivalent to the acidhydrogen content of said acidic, partial ester.

4. A grease as defined by claim 1 wherein the all-:yl hydroxya-romatic compound is nonylphenol.

5. A grease as defined by claim 1 wherein the alkaline earth, metal is calcium.

6. A grease as defined by claim 1 wherein the gelling agent comprises from about ten percent by weight to about fifty percent by weight of said grease.

7. A gelling agent prepared by the steps of: (1) reacting one molar proportion of phosphorus pentoxide with from about one to about three molar proportions of an alkyl hydroxyaromatic compound of the general formula R-A-(Ol-l)n wherein R is an alkyl group containing from eight to fourteen carbon atoms, 71 is a small whole number from one to two, and A is an aromatic nucleus, to form an acidic partial ester of phosphoric acid, and (2) forming a mixture of the acidic, partial ester obtained by step (1) and. a quantity of acetic acid from about fifty percent to about one hundred percent equivalent to said acidic, partial ester on the basis of neutralization number, and (3) reacting the mixture formed in step (2) with an alkaline earth metal compound selected from the group consisting of an oxide and "a hydroxide, at a temperature between about 400 F. and about 500 F, the amount of said metal compound being at least sufficient to neutralize the acetic acid and the acidic, partial ester.

8'. A gelling agent prepared by the steps of: (1) reacting one molar proportion of phosphorus pentoxide with from about one to about three molar proportions of an alkyl hydroxyaromatic compound of the general formula R-A-(Ol-l)n wherein R is an alkyl group containing from eight to fourteen carbon atoms, n is a small whole number from one to two, and A is an aromatic nucleus, to form an acidic, partial ester of phosphoric acid, and (2) reacting the acidic, partial ester of step (1) with a quantity of an alkaline earth metal salt to form the corresponding normal metal salt of said acidic, partial ester, and (3) reacting the said normal metal salt with an alkaline earth metal acetate at a temperature between about 400 F. and about 500 F.

9. A gelling agent prepared by the steps of: (l) reacting one molar proportion of phosphorus pentoxide with from about one to about three molar proportions of an alkyl hydroxyaromatic compound of the general formula RA--(OH)n wherein R is an alkyl group containing to form an acidic, partial ester of phosphoric acid, and (2) reacting the acidic, partial ester of step (1) with an "alkaline earth metal acetate at a temperature between about 400 F. and about 500 F., the amount of said acetate being suflicient to provide twice the amount of alkaline earth metal equivalent to the acid-hydrogen content of said acidic, partial ester.

10. A gelling agent as defined by claim 7 wherein the alkyl hydroxyaromatic compound is nonylphenol.

11. A gelling agent as defined by claim 7 wherein the alkaline earth metal is calcium.

12. A grease comprising a mineral oil having a viscosity from about 100 to about 1000 S. U. S. at 100 F. and a gelling agent in an amount of about fifteen to about twenty-five percent by weight of said grease, said grease being prepared by the steps of (1) reacting P205 with an alkyl phenol wherein R is an alkyl group containing from nine to twelve carbon atoms, to form an acidic, partial ester of phosphoric acid, and (2) adding to the partial ester obtained by step (1) a quantity of acetic acid from about fifty percent to about one hundred percent equivalent to said acidic, partial ester on the basis of neutralization number, and a quantity of said mineral oil such that the finished grease contains from about fifteen to about twenty-five percent by weight of said gelling agent, and (3) reacting the mixture formed in step (2) with an alkaline earth metal hydroxide, in an amount sufiicient to at least neutralize all of the acids of the mixture formed in step (2), and (4) heating the resulting mixture of step (3) to a temperature from about 400 F. to about 500 F., to form said grease, and (5) cooling said grease and milling said grease to a smooth consistency.

13. A grease comprising a mineral lubricating oil and a gelling agent in an amount sutficient to thicken said oil to form a grease, said gelling agent being prepared by the steps of (l) reacting phosphorus pentoxide with nonylphenol, the molar ratio of said phenol to said pentoxide being about. 3: 1, to form an acidic, partial ester of phosphoric acid, and (2) forming a mixture of the acidic, partial ester obtained by step (1) and a quantity of acetic acid about fiflty percent equivalent to said acidic, partial ester on the basis of neutralization number and a minera1 lubricating oil, and (3) reacting the mixture formed in step (2) with calcium hydroxide at a temperature of about 500 F., the amount of said calcium hydroxide being about equivalent to neutralize the acetic acid and the acid, partial ester.

14. A grease comprising a mineral lubricating oil and a gelling agent in an amount sufficient to thicken said oil to form a grease, said gelling agent being prepared by the steps of (1) reacting phosphorus pentoxide with nonylphenol, the molar ratio of said phenol to said pentoxide being about 2: 1, to form an acidic, partial ester of phosphoric acid, and (2) forming a mixture of the acidic, partial ester obtained by step (1) and a quantity of acetic acid about equivalent to said acidic, partial ester on the basis of neutralization number, and a mineral lubricating oil, and (3) reacting the mixture formed in step (2) with calcium hydroxide at a temperature of about 500 R, the amount of said calcium hydroxide being about equivalent to neutralize the acetic acid and the acid, partial ester.

15. A grease comprising a mineral lubricating oil and a gelling agent in an amount sufiicient to thicken said oil to form a grease, said gelling agent being prepared 'by the steps of (1) reacting phosphorus pentoxide with I'bricating oil, and (3) reacting the mixture formed in step (2) with barium hydroxide at a temperature of about 500 F., the amount of said barium hydroxide being about equivalent to neutralize the acetic acid and the acid, partial ester.

16. A gelling agent prepared by the steps of 1) reacting phosphorus pentoxide with nonylphenol, the molar ratio of said phenol to said pentoxide being about 3:1,

to form an acidic, partial ester of phosphoric acid, and

(2) forming a mixture of the acidic, partial ester obtained by step 1) and a quantity of acetic acid about fifty percent equivalent to said acidic, partial ester on the basis of neutralization number, and a mineral lubricating oil, and (3) reacting the mixture formed in step (2) with calcium hydroxide at a temperature of about 500 F., the amount of said calcium hydroxide being about equivalent to neutralize the acetic acid and the acid, partial ester.

17. A gelling agent prepared by the steps of (1) reacting phosphorus pentoxide with nonylphenol, the molar ratio of said phenol to said pentoxide being about 2:1, to form an acidic, partial ester of phosphoric acid, and (2) forming a mixture of the acidic, partial ester ob- .tained by step (1) and a quantity of acetic acid about equivalent to said acidic, partial ester on the basis of neutralization number, and (3) reacting the mixture .formed in step (2) with calcium hydroxide at a temperature of about 500 F., the amount of said calcium hydroxide being about equivalent to neutralize the acetic acid and the acid, partial ester,

References Cited in the file of this patent UNITED STATES PATENTS 2,200,299 Robinson May 14, 1940 M 2,228,659 Farrington et a1. Jan. 14, 1941 2,322,307 Neely et al -1 June 22, 1943 1 2,329,707 Earring-ton et al Sept. 21, 1943 2,409,774 Mack et a1. Oct. 22, 1946

Claims (1)

1. A GREASE COMPRISING AN OLEGINOUS LUBRICANT AND A GELLING AGENT IN AN AMOUNT SUFFICIENT TO THICKEN SAID VEHICLE TO FORM A GREASE, SAID GELLING AGENT BEING PREPARED BY THE STEPS OF: (1) REACTING ONE MOLAR PROPORTION OF PHOSPHORUS PENTOXIDE WITH FROM ABOUT ONE TO ABOUT THREE MOLAR PROPORTIONS OF AN ALKYL HYDROXYAROMATIC COMPOUND OF THE GENERAL FORMULA R-A-(OH)N WHEREIN R IS AN ALKYL GROUP CONTAINING FROM EIGHT TO FOURTEEN CARBON ATOMS, N IS A SMALL WHOLE NUMBER FROM ONE TO TWO, AND A IS AN AROMATIC NUCLEUS, TO FORM AN ACIDIC, PARTIAL ESTER OF PHOSPHORIC ACID, AND (2) FORMING A MIXTURE OF THE ADIDIC, PARTIAL ESTER OBTAINED BY STEP (1) AND A QUANTITY OF ACETIC ACID FROM ABOUT FIFTY PERCENT TO ABOUT ONE HUMDRED PERCENT EQUIVALENT TO SAID ACIDIC, PARTIAL ESTER ON THE BASIS OF NEUTRALIZING NUMBER, AD (3) REACTING THE MIXTURE FORMED IN STEP (2) WITH AN ALKALINE EARTH METAL COMPOUND SELECTED FROM THE GROUP CONSISTING OF AN OXIDE AND A HYDROXIDE, AT A TEMPERATURE BETWEEN ABOUT 400*F. AND ABOUT 500*F., THE AMOUNT OF SAID METAL COMPOUND BEING AT LEAST SUFFICIENT TO NEUTRALIZE THE ACETIC ACID AND THE ACIDIC, PARTIAL ESTER.