US2983682A - Lubricating oil thickened to a grease consistency with a mixture of a tetraphenylphthalyl compound and an organophilic siliceous compound - Google Patents

Description

are represented by the formula:

2,983,682 LUBRICATING OIL THICKENED TO A GREASE CONSISTENCY WITH A MIXTURE OF A TETRA- PHENYLPHTHALYL COMPOUND AND AN R- GANOPHILIC SILICEOUS COMPOUND Robert E. Halter, Verona, and Joseph J. McGrath, Monroeville, Pa., assignors to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware k No Drawing. Filed July 10, 1959, Ser. No. 826,143 r 14 Claims. (Cl. 252-495) invention relates to improved lubricating compositions and more particularly to lubricants suitable for high temperature lubrication.

The trend in design of modern aircraft has accentuated the need forgreases which willlubricate anti-friction United States PatcntO ice bearings operating at high rotational speeds and high temperatures. While considerable progress has been made in recent years in producing improved aircraft greases somedifiiculty has been encountered in producing a grease which will efiectively lubricate bearings opcrating-lat high rotational speeds and high temperatures for prolonged periods of time. Conventional aircraft greases currently available have failed to meet the stringent requirements on such a lubricant.

We have discovered that a lubricating composition having improved lubricating characteristics for an extended period of time when used to lubricate bearings operating at anelevated temperature under high rotational speeds can be obtained by incorporating into a lubricating oil in oil thickening proportions a mixture of a tetraphenylphthalyl compound selected from the group consisting of tetraphenylphthalic acid and derivatives thereof selected from the group consisting of the anhydride, monoand di-alkali metal salts, monoand di-amides,

alkali metal salts of mono-amides, monoesters, alkali metal salts of monoesters, and im-ides and a secondary organcphiiic siliceous thickening agent. Thus, the im-,

proved lubricatingcomposition of our invention com- :prises .a dispersion in a lubricating oil of a sufficient amount to thicken the lubricating oil to a grease con- 2,983,682 Patented May 9, 1961 where A is selected from the group consisting of OR, OM and NRRQ'Where M is an alkali metal and R and R are selected from the group consisting of H and aliphatic, alicyclic and aromatic hydrocarbon radicals having from 1 to 22 carbon atoms.

Examples of R and R as aliphatic, alicyclic and arc matic hydrocarbon radicals include methyl, ethyl, propyl, n-butyl, tertiary butyl, pentyl, cyclopentyl, hexy, 2,3-dimethylbutyl, cyclohexyl, heptyl, 2-ethylhexyl, isooctyl, n-octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, phenyl, naphthyl, and the like.

Specific examples of some of the tetraphenylphthalamates are:

N-methyl tetraphenylphthalamate N,N-d-irnethyl tetraphenylphthalamate N-butyl tetraphenylphthalamate N,N-ditertiary-butyl tetraphenylphthalamate N-cyclohexyl tetraphenylphthalamate N,N-dicyclohexyl tetraphenylphthalamate N-isooctyl tetraphenylphthalamate N,N-diisooctyl tetraphenylphthalamate N-octadecyl tetraphenylphthalamate N-eicosyl tetraphenylphthalamate N-docosyl tetraphenylphthalamate N-phenyl tetraphenylphthalamate N,N-diphenyl tetraphenylphthalamate N-naphthyl tetraphenylphthalamate Sodium N-methyl tetraphenylphthalamate Potassium N,N-dimethyl tetraphenylphthalamate Lithium N-butyl tetraphenylphthalamate Sodium N,N-ditertiary-butyl tetraphenylphthalamate Potassium N-cyclohexyl tetraphenylphthalamate I Lithium N,N-dicyclohexyl tetraphenylphthalamate sistency of a mixture of a tetraphenylphthalyl compound of the type designated above and an organophilic siliceous oil thickening agent.

U ,The amount of the combined tetraphenylphthalyl compound and the organophilic siliceous material which we use is an amount sufiicient to thicken the lubricating oil to a grease consistency. In general, this amount comprises about 10 to about 60 percent by Weight of the L total composition. The Weight ratio of the tetraphenylphthal-yl compound to the organophilic siliceous material will vary depending upon the characteristics desired in the ultimate composition. in general, however, the ratio of tetraphenylphthalyl compound to the organophilic siliceous materialis between about 1:1 and about :1.

The tetraphenylphthalyl compounds which We can employ include tetraphenylphthalic. acid, tetraphenylphthalic anhydr ied, monoand di-sodium tetraphenylphthalates,

mono and iii-potassium tetraphenylphthalates, monoand di-lithium tetraphenylphthalates, monoand di-tetraphenylphthalamates, alkali metal salts of mono-tetraphenylphthalamates, monoesters of tetraphenylphthalic acid, alkali metal salts of monoesters of tetraphenylphthalic acid and ,tetraphenylphthalimides. l

l The -monoand di-tetraphenylphthalamates and the alkali metal salts of the mono-tetraphenylphthalamates Octadecyl N-butyl tetraphenylphthalamate Eicosyl N-butyl tetraphenylphthalamate The monoesters of tetraphenylphthalic acid and the alkali metal salts of the monoesters of tetraphenylphthalic acid are represented by the formula:

. 1 3 lected from the group consisting of aliphatic, alicyclic and aromatic hydrocarbon radicals having from 1 to 22 carbon atoms. Specific examples of some of the monoesters of tetraphenylphthalic acid and the alkali metal salts of the monoesters of tetraphenylphthalic acid are:

Mono-methyl tetraphenylphthalate Mono-n-butyl tetraphenylphthalate Mono-tertiary-butyl tetraphenylphthalate The imides of tetraphenylphthalic acid are represented by the formula:

where R is selected from the group consisting of hydrogen and aliphatic, alicyclic and aromatic radicals having from 1 to 22' carbon atoms.

Specific examples of some of the imides of tetraphenylphthalic acid are: i

N-methyl tetraphenylphthalimide N-ethyl tetraphenylphthalimide N-propyl tetraphenylphthalimide N-butyl tetraphenylphthalimide N-cyclohexyl tetraphenylphthalimide N-octyl tetraphenylphthalimide N-decyl tetraphenylphthalimide N-dodecyl tetraphenylphthalirnide N-tetradecyl tetraphenylphthalimide N-hexadecyl tetraphenylphthalimide N-octadecyl tetraphenylphthalimide N-eicosyl tetraphenylphthalimide N-docosyl tetraphenylphthalimide N-phenyl tetraphenylphthalimide ,N naphthyl tetraphenylphthalimide 57? The amount of the tetraphenylphthalyl'compiund used may vary over wide limits depending upon the particular oil with which the tetraphenylphthalyl compound is to be blended and upon the proper-ties desired in the final lubricating composition. While as much as 50 percent by weight of the total composition may comprise .the

tetraphenylphthal-yl compound, weprefer to use smaller removed by distillation at 92-94? 0/20 mm. The re'sidue after two recrystallizations from carbon tetrachloride,

amounts, that is, in the order of about 10 to 40 percent 6 "-5 should be understood, however, that, depending upon the consistency of .the composition desired and upon the organophilic siliceous material used in combination therewith, less than 10 percent or more than 50 percent of the tetraphenylphthalyl compound may be employed.

' The tetraphenylphthalyl compounds "can 'be prepared according to known chemical procedures. Neither the compounds per se nor their preparation constitutes any portion of the invention. The preparation of tetraphenylphthalic anhydride, for example, can be prepared according to a procedure described in the Journal of the American Chemical Society, volume 67, page 1229, (1945). The alkali metal salts, the amides, the esters and the imides can be prepared according to known salt-forming, amidation, esterification and imidation procedures, respectively. The following illustrative examples will serveto demonstrate the preparation of some of the specific tetraphenylphthalyl compounds. The utility of these tetraphenylphthalyl compounds informing lubricating compositions of the invention is illustrated by the data presented in Table I.

EXAMPLE 1 (Tetraphenylphthalic anhydride) i A mixture of 384 gm. (1 mole) of tetraphenylcyclopentadienone and 146 gm. (1.1 mole) chloromaleic an hydride was refluxed for 4 hours. The mixture was cooled to 0 C. and filtered. The crystals of tetra- :phenylphthalic anhydride Were first washed with asmall amount of cold bromobenzene and finally with petroleum ether (B.P. 60-70 C.). The melting point of the tetraphenylphthalic anhydn'de crystals was 294296 C.

EXAMPLE 2 (Disoa'ium tetraphenylphthalate) e To 124 g. of tetraphenylphthalic anhydride in suflicient 95% ethanol to give a slurry was added 3140 ml. of 0.35 N alcoholic sodium hydroxide. This mixture was heated at reflux temperature for sixteen hours, cooled and filtered. The filtrate was heated to boiling and diluted with hot water until crystallization occurred,

cooled to 0 C. and filtered. The product, disodium tetraphenylphthalate, after drying at C. melted above 400 C. (752 F.).

EXAMPLE 3 (Methyl N-n-octadecylletrapherzylphthalamate) Phosphorus trichloride (10.4 gm., 0.076 mole) was added dropwise to a stirred suspension of 79.3 gm. (0.152

'mole) of potassium methyl tetraphenylphthalate and 819 gm. (0.304 mole) of moctadecylamine in ml.

of toluene in a Morton flask. During the addition the "temperature rose from 24 C. to 55 C. An additional 100 ml. of toluene was added to counteract solidification.

The mixture was heated at reflux for thirty hours after decyltetraphenylphthalamate, a solid, melting at SS-{85 (Mono-isooctyl ietraphenylphthallate) Ten grams (0.021 mole) of tetraphenylphthalic anhydride and 46 gm. (0.2 mole) isooctyl alcohol'wererefluxed for 2 hours. The unreacted isooctyl alcohol was comprising mono-isooctyl tetraphenylphthalate had a melting point of 294;295 C. i

phthalic anhydride and 20.4 gm. (0.2 mole) of n-hexanol was refluxed for 1.5 hours. The excess alcohol was removed by distillation at 100 C./25 mm. The residue after two. crystallizations from carbon tetrachloride gave a product, mono-n-hexyl tetraphenylphthalate, melting at 295-296 C.

The organophilic siliceous materials which we employ in the lubricating composition of this invention are exemplified by bentonite organic base compounds known commercially as Bentones and finely divided organosiliceous solids such as the esterified siliceous solids known commercially as Estersils. The amount of the organophilic siliceous material employed may vary over .wide limits depending upon the particular compound employed, the particular oil with which the siliceous compound is blended and the properties desired in the ultimate composition. While the organophilic siliceous material may comprise as much as 20 percent by weight of the total composition, we prefer to use smaller amounts, that is, in the order of about 1 to about percent by weight. It should be understood, however, that depending upon the consistency of the composition desired and upon the tetraphenylphthalyl compound content of the composition less than 1 percent or morethan 10 percent of the organophilic siliceous material can be employed.

fTypical bentonite-organic base compounds employed in accordance withthe invention are compounds composed of a montmorillonite mineral in which at least a part of the cation content of the mineral has been replaced by an organic base.

Clays that swell at least to some extent on being contacted with water and contain as a primary constituent a mineral of the group known (The bentonite-organic base compounds are. preferably prepared as described in US. Patent No. 2,033,856, is-

sued March 10, 1936 by bringing together the bentonite and the organic base in the presence of aqueous mineral acid to effect base exchange. The organic bases should preferably be titratable with mineral acids. Among these .reactive bases are many alkaloids, and cyclic, aliphatic, and heterocyclic amines. The bentonite-organic base compounds used in preparing the lubricating compositions of this invention are preferably these. prepared by bringing together a bentonite clay and such organic bases "asaIiphatic amines, their salts, and quaternary ammoriium salts. Examples of such amines and salts are:

jdecylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, hexadecyl ammonium acetate,

octadecyl ammonium acetate, .dirnethyldioctyl ammonium acetate,,dimethyldidodecyl ammonium acetate, di-

fm ethyldodecylhexadecyl ammonium acetate, dimethyldicetyl ammonium acetate, dimethylhexadecylocta'decyl ammonium acetate, dimethyldioctadecyl ammonium ace tate, and the corresponding chlorides and quaternary ammonium chlorides. fThe organic bases employed should be such as to impart substantial organophilic The preferred ammonium compounds in which the N-substituents are aliphatic groups jcontaining"at least one alkylj group "witha total of at least 10 to 12 carbon atoms. When aliphatic amines are used they preferably'contaiii. at least bentonite compounds, in the oil, particularly mineral oils and synthetic oils other than ester lubricants, can be facilitated by the use of one or more solvating agents. Suitable solvating agents are polar organic compounds such as organic acids, esters, alcohols, ethers, ketones, and aldehydes, especially low molecular weightcompounds of these classes. Examples of suitable solvating agents are: ethyl acetate, acetic acid, acetone, methyl alcohol, ethyl alcohol, benzoylchloride, butyl stearate, cocoanut oil, cyclohexanonejethylene dichloride, ethyl ether, furfural, isoamyl acetate, methyl ethyl ketone, and nitrobenzene. In cases where the use of'a solvating agent is desirable for efiecting more rapid and more complete dispersion of the organic bentonite compound in the oil, ordinarily only a relatively small amount of such agent may be necessary. However, as much as about 50 percent by weight based on the amount of the bentonite compound can be used.

' Typical estersils employed in accordance with the invention are described in US. Patent No. 2,657,149, issued October 27, 1953 to R. K. Iler. The estersils are organophilic solids made by chemically reacting primary or secondary alcohols with certain siliceous solids. In brief, the estersils are prowders or pulverulent materialsthe internal structure or substrate of which have a bound organic groups prior to esterification. Thesubstrates are in a supercolloidal state of subdivision, indicating that whatever discrete particles are present are larger than colloidal size. In general, the supercolloidal substrates have at least one dimension of at least 150 millimicrons. The supercolloidal particles may be aggregates of ultimate units which are colloidal in size.

The estersils which we employ are advantageously those in which the ultimate units have an average diameter of 8 to 10 millimicrons. The substrates advantageously have specific surface areas of at least 25 square meters per gram and preferably at least 200 square meters per gram.

The estersils made from most alcohols become organophilic when they contain more than about 80.ester groups per 100 square millimicrons of surface of internal structure." They become more organophilic as the ester groups increase. Thus, the products which contain 100 ester groups per '100 square millirnicrons of substrate surface are more organophilic than those that contain only ester groups. When the estersils contain at least 200 ester groups per square r nillimicrons of substrate surface, the estersils not only are organophilic but also are hydro phobic. Thus, the more highly esterified products are particularly desirable where the lubricant made therefrom comesin contact-With water. When C to C alcohols are used in preparing the estersils, the estersils may contain froin 300 to 400 ester groups per 100 square milliriiicronsof substrate surface. Thus, a preferred group of estersils are those prepared-from the C to C alcohols. The'estersils, asnotedabove, are powders or pulverulent, materials. ,lThe, estersil. powders are exceedingly fine,

light and The bulk densityb'f preferred estersils .isin the'order of to 0.20 gram percufbic. centimeter a't 3 pounds per square inch and in the order of about .the estersils per se and their ;we r'nean an oil of non-mineral origin. .oil can be an organic ester which has a majority of the 0.30 gram per cubic centimeter at 78 pounds per square rated is preferably a lubricant of the type best suited for the particular use for which the ultimatecomposition is the lubricating oil are imparted to the ultimate lubricating composition, we'advantageously employ an oil which is .thermally stable at the contemplatedlubricating temperature. Some mineral oils, especially hydrotreated mineral oils, are sufliciently stable to provide a lubricating base for preparing lubricants to be used under moderately elevated temperatures. Where temperatures in the order ,of. 400 Rand above are to be encountered, synthetic oils form a preferred class of lubricating bases because of their high .thermal stability. By the term synthetic oil The synthetic properties of a hydrocarbon oil of lubricating grade such asdi-Z-ethylhexyl sebacate, dioctyl phthalate and dioctyl azelate. In stead of an organic ester, we can use polymerized olefins, copolymers of alkylene glycols and alkylene oxides, polyorgano siloxanes and the like.

' The liquid polyorgano siloxanes because of their exceedingly high thermal stability form a preferred group of synthetic oils to which the tetraphenylphthalyl compound and organophilic siliceous materials are added. These llpolyorg ano siloxanes are known commercially as silicones and are made up of silicon and oxygen atoms wherein the silicon atoms may be substituted with alkyl, aryl,

alkaryl, aralkyl and cycloalkyl radicals. Exemplary of such compounds are the dimethyl silicone polymers, di-

ethyl silicone polymers, ethyl-phenyl silicone polymers and methyl-phenyl silicone polymers.

Ifdesired, a blend of oils of suitable viscosity may be employed as the lubricating oil base instead of a single oil by means of which any desired viscosity may be secured. Therefore, depending upon the particular use for which the ultimate composition is designed, the lubricating oil base may be a mineral oil, a synthetic oil, or a mixture of mineral and/or synthetic oils. The lubricating oil content of the compositions preparedaccording to this invention comprises about 40 to about 90 percent by'weight of the total composition.

-In compounding the compositions of the present invention, various mixing and blending procedures may be used. In a preferred embodiment of the invention, the lubricating oil, the tetraphenylphthalyl compound and the secondary thickener together with a solvating agent and conventional lubricant additives, if desired, are mixed together at room temperature .for a period of to 30 "minutes to form a'slurry. During this initial mixing 'period some thickening is evidenced. Some lumps may be formed. The slurry thus formed is then subjected to a conventional millingoperation in a ball mill, a colloid mill, homogenizer or similar device used in compounding greases to give the desired degree of dispersion. In the illustrative compositions of this invention, the slurry was passed twice, by means of a pump, through a PremierfColloid Mill set at a stator-rotor clearance of 0.002 inch. Maximu'm thickening occurred on the second pass through themill.

The lubricating composition of this invention can contain conventional lubricant additives, iffdesired, wiml'prove other specific properties of the lubricant without departing from the scope of the invention. Thus, the ',l'ub'r'i'cating composition, cancontain "a filler, a corrosion ,rusflinhibitor,,an extreme pressure; agent, an antiioxida n t', .a metal deactivator, a? dye, and the "like. Whether er-ne such'jiaidditives arT'ernployed'. and the amounts n'theseverity of 'ndlto a, large extent the tetraphenylphthalyl 7 designed. Since many of the properties possessed by '10 sired elevated temperature which in the tests reported 8 the conditions to which the composition is subjected and upon thestability of the lubricating oil base in the first instance. 'Since thepolyorgano siloxanes, for example,

i are in general more stable than mineral oils, theyrequire theaddition of very little, if any, oxidation inhibitor.

When such'conventional additives are used theyv are generally added in amounts between about 0:01 and 5 percent by weight'based on the weight of the total composition. y M -In order to illustrate the lubricating characteristics at an elevated temperature andhigh rotational speeds, grease compositions of the invention were subjectedto the test procedure outlined by the Coordinating Research Council Tentative Draft (July, 1954), Research Techniquefor the. Determination of Performance Characteristics of Lubricating Grease in Antifriction Bearings atElevated Temperatures, CRC Designation L-35. According. to

this procedure, 3 grams of the grease. to be tested are "placed'in. a bearing assembly containing an eight-ball which the test bearing assemblyis located is encased in a thermostatically controlled oven; By this means the temperature of the bearing can be maintained at a defhereinafter was 400? F. The spindle is driven by a constant belt-tension motor drive assemb y, capableof giving spindle speeds up to 10,000 revolutions per minute. The spindle-is operated on a cycling schedule consisting of 1a"series of. periods, each period consisting of 20 'hours running time and 4 hours shutdown time. The

test continues until the lubricant fails. The-lubricant is considered to have failed when any one of the followingconditions occurs, (1) spindle input power increases to a value approximately 300 percent above the steady .state condition atfthe test temperature; (2) an increase in' temperature at the test bearing of 20 F. over the test temperature during any portion of a cycle; or (3) the test bearing locksor the drive belt slips at the starter during the test cycle.

summarized in Table I were synthetic oils known commerically as GE Silicon 81717 and DC 550 Fluid. GE

'Silicone, 81717 is marketed by General Electric Company and is a water-white the general formula I 3 2 3 K 3 2 3 )2 l x It has'a viscosity at "-65 FQof 3487 centistokes, at 0 F. of 390 centistokes, at F. of 71.3 centistokes, at 210? F. of 22 centistokes and at 700 F. of 1.9 centistokes. DC 550 Fluid is marketed by Dow-Corning corporationandis" a methylphenyl-siloxane polymer having as typical characteristics a viscosity at 100 F. of 300 to :400 SUS, .a viscosity-temperature coefiicientof 0.75, a freezing point of --54 F., a flash point of 600 and a specific gravity 25 C./25 C. of 1.08. y The Ester'sil GT employed is marketed by E.I. du Pont de;Nemours and Company and consists of an amorphous silica coated with approximately 340 butoxy groups per 100 square millimicrons' of surface. The productzis a .White granular solidjcompris ing. 88 to 89 percent SiQ having an ultimate particle sizeof 8 to 10 millimicrons.

The surface ;area :comp'rises about 285- to 335 ;square imet'ers per gram. The product has a pH in a]505 0 methanol-water mixture of 8.0 to 9.0 and a bulk density fIr'i preparing the lubricating compositions, the

hthalyl compound and the di' th'y'ldicetylentonite or estersil were n'tixe atiqr'n' cmto amber liquid polymer of 9 peratu're for a periodof'lll to 30 minutes. The slurry thus formed was passed twice through a Premier Colloid Mill set at a stator-rotor clearance of 0.002 inch. The thickened lubricating compositions thus prepared had the following approximate make-up".

TABLE 1 10 where Af-is selected from the group consisting of OR, OM and NRR Where M is an alkali metal and R and R are selected from the groupconsisting of hydrogen and aliphatic, alicyclic and aromatic hydrocarbon radicals having from 1 to 22 carbon atoms; inonoesters of tetraphenyl- Composition, Percent By Weight A Lubricating on:

on Silicone 81717 DC 550 Fluid Tetraphenylphthalyl Compound:

'letraphenylphthalie ,anhydride.

Disodium tetraphenylphth'tlam Meth f N-n-octadecyltetraphenylphthalmun P Mono lsoo cytyl 'tetraphenyiphthalate.

Mono-u-hexyl tetranhenvlnhthalmn Secondary Thickener:

Dimethyldicetylammonium bentonite Estersil GT. i j Ratio of tetraphenylphthalyl compound to secondary thickener Inspection: U i H PeErformance Lite,lHrs -10,000 r.p.m.;at 400 i The long performance life of the compositions of the invention at a high rotational speed and a high tempera-" ture is self evident from the above data. Other lubricating compositionsyvithinthe scope of the invention are illustrated in Table II. t

phthalic acid and alkali metal salts of monoesters of tetraphenylphthalic acid having the formula TABLE 2' Composition, :Percent-By Weight Di-2-ethylhexy1 sebar-m Tetraphenylphthalyl Compound;

N,N-dimethy1 tetraphenylphthalamate;; t

' Sodium N-octadecyltetraphenylphthalama 7 Sodium mono-dodccyl tetraphenylphthalate Mono-cyclohexyi tetraphenylphthalate Secondary Thickener: L

Dimethyldicetylammonium tientnntt I "Dimethyldidodecylammbniumbntonite Dimethyldioctylammon urn bentonite Dimethyldidctadecylam'rfnoiiium bentonlte EstersilGT 1 Ratio of tetraphenylphthalyl compound to secondary thickener 8:1 4:1 4:1

While our invention has been described with reference to various specific examples and embodiments, it will be understood that the invention is not limited to such examples and embodiments and may be variously practiced within the scope of the claims hereinafter made.

We claim:

1. A lubricating -corn'r' aosition comprising a dispersion:

in a lubricating oil era suflicie'nt amount to thicken the lubricating oil to. a gfa'se' cdnsistency of a mixture of a tetraphenylphthaly m'poundisel ected from the group consisting of "tetraph 'ylphthalic acidfand derivatives thereofsle'cted fro amates and alkali metal salts of mono tetraphenylphthalamates having the formulai a iooNan p the group consisting of tetraphenylphthalic anhydr id'eymono and di-alkali metal salts of "tetraphenylphthalic acid;"m'onoand 'di-tetraphenylphthalwhere .X iss'lected from the group consisting of hydrogen and an alkali metal and R", isfselected from the group consisting of aliphatic, alicyc'lic and aromatic hydrocanbon radicals having from 1 to 22 carbon atoms; and imides of tetraphenylphthalic acid having the formula where R is selected from the group consisting of hydrogen and aliphatic, alicyclic and aromatic hydrocarbon radicals having from 1 to 22 carbon atoms; and an organophilic siliceous oil uthickening iagent, the weight ratio of the ,tetraphenylphthalyl COIIIPOIlIldxtO the organophilic siliceous material in said mixture being about 1:71 to labout 50:11.

75 2. ';I?he :lubricating composition of claim 1 wherein the 5. The lubricating composition of claim 1 wherein the organophilic siliceous oil thickening agent is an organophilic esters'il comprising a supercolloidal substrate coated with --OR' groups, the substrate having a surface of silica 6. A lubricating composition comprising a dispersion in lubricating oil. to a grease consistency of a mixture of a tetraphenylphthalamate, having the formula:

GOA

and having a specific surface area of from 1 to 900'sqi1areI are Selected from group conslstmg of hydrogen and meters per gram, the coating of -'OR' groupsbeing chemaliphatic, alicyclic and aromatic hydrocarbon radicals having from late 22 carbonatoms and an organophilic siliceous oil thickening agent, the weight ratio of the tetraphenylphthalamateito the organophilic siliceous material in ,said mixture being about 1:1 to about50:l.'

a liquid polyorgano silox-ane of a sufficient. amount to thicken the polyorgano siloxane to a greaseconsistency of a mixture of a tetraphenylphthalyl compound selected from the group consisting of tetraphenylphthalic acid and derivatives thereof selected from the group consisting of tetraphenylphthalic anhydride; monoand di-alk-ali metal;

8. The lubricating composition of claim 7 wherein the tetraphenylphthalamate' is methyl N-n-octadecyltetra-' phenylphthalamate. t a

9. A lubricating composition comprising a dispersion in a lubricating oil of a sufficient amount to thicken the lubricating where A is selected from the group consisting of OR, 0M1; and NRR' where M is an alkali metal and R and R,

are selected from the group consisting of hydrogen and aliphatic, alicyclic and aromatic hydrocarbon radicals having from 1 to 22 carbon atoms; monoesters of tetraphenylphthalic acid and alkali metal salts of monoester of tetraphenylphthalic acid having the formula a coox oil to a grease consistency of a mixture of a tetraphenylphthalate having theformula:

COOK "whr'exis selected fromlthe'group consisting of hydroradicals having from 1 to 22 carbon atoms and an organophilic siliceous oil thickening agent, the weight ratio of the tetraphenylphthalate: to the organophilic siliceous 11. The lubricating composition of claim9 wherein the tetraphenylphthalate is mono-n-hexyl tetraphenylj phthalate.

12, A lubricating composition comprising a dispersion f in a lubricating oil ofa sufiicient amount to thicken the lubricating oil to a grease consistency of a mixture of a t E t t 7 5 where X is selected from the groupconsisting of hydroand. a iphatic, alicyclic and; aI-Q fl hydrogiarbon radicals h vin rom '1 tozz carbo tatougs a a .v o p i 1 s; oil thicke ngiagcnmth we ratio of h tetraphenylphthalimide:ito theorganophilic siliceous mawhere R is selected from the group consisting of hydrogen 7 and aliphatic,.alicyclic and aromatic hydrocarbon radicals havingfrom 1;;to,22 carbon atoms; and an organophilic tbentonite-organic, base compound; the. weight ratio OfIhCg' al'lubr'icating' oil of a sufficient amount to thickfiitl the tetraphenylphthalimide having the formula:

where Ris selected from-thegroup consisting of hydrogen 'terial -in said-mixture b,eing-,abouti'1:1 to about 50: 1 q 13. Aglubricatingcomposition comprising a, dispersion in' a liguid polyo'rgano siloxanejof ;a sufiicient amount to thicken the polyorgari'o; siloxanewto= a grease consistency of a mixture of a tetraphenylphthalylcompound selected from the group consisting of tetraphenylphthalic acid and derivatives thereof selected from the group consisting of the anhydride, mono 'an'ddialkali metal salts, monoand di-amides, alkali metal salts of mbnoamides, monoesters, alkali metal salts of monoesters and imides and an organophilic estersil, the weight ratio of the tetraphenylphthalyl compound to the organophilic estersil in said mixture being about 1:1 to about 50:1, said organophilic estersil compn'sing a supercolloidal substrate coated with -OR' groups, the substrate having a surface of silica and having a specific surface area of from 25 to 900 square meters per gram, the coating of OR groups being chemically bound to said silica and R being a hydrocarbon radical of from 3 to 6 carbon atoms, wherein the carbon atom attached to oxygen is also attached to hydrogen.

14. The lubricating composition of claim 13 wherein the tetraphenylphthalyl compound is methyl N-n-octadecyltetraphenylphthalamate and the organophilic estersil is an amorphous silica coated with about 340 butoxy groups per 100 square millimicrons of surface.

References Cited in the file of this patent UNITED STATES PATENTS 2,578,851 Smith et a1. Dec. 18, 1951 2,710,839 Swakon et al June 14, 1955 2,756,213 Dixon July 24, 1956 2,766,209 Marshall et a1. Oct. 9, 1956 2,806,877 Koenecke et al Sept. 17, 1957 2,820,012 Hotten Jan. 14, 1958 UNITED STATES PATENT OFFICE Certificate of Correction P t I ene. 2,983,682 May 9,1961

Robert E. Halter et a1.

It ;is hereby certified that error appears in the above numbered patent requiring correction and that the sald Letters Patent should read as corrected below.

Column 1, line 57, for anhydried read anl1ydride compiund read compound; column 6, line 30, for prowc dp6wdens column 9, Table 1, first column thereof, eighth item, for Mono-isoocytyl read -Mono is00ctyl; same table and same column, third line from the bottom, for (ASTM 135566-42) read (ASTM D566- 12); column 12, line '72, beginning with the anhydride, monoand strike out all to and including imides in line 74, same column, and insert instead the following: -tetraphenylphthalic anhydride; monoand di-alkali metal salts of tetraphenylphthalic acid; monoand di-tetraphenylphthalamates and alkali metal salts of mono-tetraphenylohthalamates having the formula where A is selected from the group consisting of OR, OM and NRR where M is an alkali metal and R and R are selected from the group consisting of hydrogen and aliphatic, alicyclic and aromatic hydrocarbon radicals having from 1 to 22 carbon atoms; monoesters of tetraphenylphthalic acid and alkali metal salts of monoesters of tetraphenylphthalic acid having the formula COOX COOR where X is selected from the group consisting of hydrogen and an alkali metal and R" is selected from the group consisting of aliphatic, alicyclic and aromatic hydrocarbon radicals having from 1 to 22 carbon atoms; and imides of tetraphenylphthalic acid having the formula where R is selected from the group consisting of hydrogen and aliphatic, alicyclic and aromatic hydrocarbon radicals having from 1 to 22 carbon atoms Signed and sealed this 10th day of October 1961.

Attest: ERNEST W. SWIDER, Attest'i'ng Ofiicer.

DAVID L. LADD, Gammz'ssionw of Patents.

Claims (1)

1. A LUBRICATING COMPOSITION COMPRISING A DISPERSION IN A LUBRICATING OIL OF A SUFFICIENT AMOUNT TO THICKEN THE LUBRICATING OIL TO A GREASE CONSISTENCY OF A MIXTURE OF A TETRAPHENYLPHTHALYL COMPOUND SELECTED FROM THE GROUP CONSISTING OF TETRAPHENYLPHTHALIC ACID AND DERIVATIVES THEREOF SELECTED FROM THE GROUP CONSISTING OF TETRAPHENYLPHTHALIC ANHYDRIDE, MONO- AND DI-TETRAPHENYLPHTHALTETRAPHENYLPHTHALIC ACID, MONO- AND DI-TETRAPHENYLPHTHALAMATES AND ALKALI METAL SALTS OF MONO-TETRAPHENYLPHTHALAMATES HAVING THE FORMULA