CA1050524A

CA1050524A - Grease manufacture

Info

Publication number: CA1050524A
Application number: CA230,533A
Authority: CA
Inventors: Francis S. Sayles
Original assignee: Mobil Oil Corp
Current assignee: ExxonMobil Oil Corp
Priority date: 1974-07-01
Filing date: 1975-06-30
Publication date: 1979-03-13
Also published as: DE2528600A1; JPS6019954B2; FR2277143B1; JPS5925836B2; DE2560382C2; DE2528600C2; US3904534A; FR2277143A1; AU497712B2; JPS5124604A; AU8259475A; ZA754010B; GB1507698A; GB1507697A; JPS56127691A

Abstract

ABSTRACT OF THE DISCLOSURE

Greases containing a calcium or calcium/lead complex thickener, a terpolymer improver and a paraffinic base lubricating vehicle. The greases have a thicker consistency than is normally obtained with paraffinic base stocks. They are produced by introducing the terpolymer to the charge of the lubricating vehicle and thickening agent components prior to saponification.

Description

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B~CKGROUMD OF THE INVENTION
Field of the Invention This invention relates to greases and more particularly, to greases which contain a calcium or calcium~lead complex thickener.

Description of the Prior Art Calcium soaps have been used for a long time as grease thickeners.
For example, J. I. Clower referred to the use of lime base greases in "Lubricants and Lubrication", First Edition, McGraw-Hill, New York 1939, page 68 et ~ The soaps are produced by the saponification of fatty materials (naturally occurring triglyceride esters or the fatty acids derived from the glycerides) with lime, as is conventional in the art.
The use of various complex soap thickeners such as the mixed calcium salts and soaps is also known. For ex~mple,Boner in "Manufacture and Application of Lubricating Greases", ~ieger, 1971 (reprint of 1954 edition), Chapter 16 refers extensively to such complex soap thickeners and Liddy U.S. Patent No. 2,999,065 discloses the use of calcium complex thickeners derived from low, intermediate and high molecular weight acids. Schott U.S. Patent No. 2,898,297 describes a calcium complex thickener which includes calcium soaps derived from nut oil acids.
The lubricating vehicle base stocks which have been used with these thickeners have been naphthenic in nature. That is, the hydrocarbons in the base stock have been predominantly alicyclic rather than straight chain. These base stocks have been preferred because they give a firm-bodied grease whereas paraffinic base stocks yield soft-bodied greases with the same amount of a given soap thickener. Thus, the naphthenic base stocks give a better yield of grease in relation to the amount of thickener. Although it would be possible to use a greater amount of thickener to produce a grease of given consistency ., ~ -2-:

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using a paraffinic base stock, the high cost of soap relative to that of the oil has generally made this uneconomical. In addi-tion the amount of soap necessary to produce a thick bodied base with a paraffinic base, e.g. NLGI Grade 3, can lead to an un-stable grease structure. Such a grease might soften during use (as a result of which it might run out of the bearings in which it was being used) or it might harden in use and block the bearing completely.
U. S. Patent 3,705,853 to Fau et al describes the use of ~ 10 certain ethylene terpolymers as improvers in calcium and ; calcium/lead thickened greases.
SUMMARY OF THE INVENTION
I have now diseovered that firm bodied greases can be made economically from paraffinie base stoeks. The thickeners used in these greases may be ealcium complex or caleium/lead -complex thickeners, although the former are preferred. In addition to the lubricating vehiele base and the eomplex thick-ener the greases contain a terpolymer improver and any other additive desired, e.g. rust inhibitors, extreme-pressure agents and antioxidants.
According ts the present invention I therefore provide a grease composition comprising (i) a pr~dominantly paraffinie lubricating vehiele, (ii) a thickener comprising a ealcium or ealeium/lead complex and (iii~ an organic terpolymer improver.
More particularly, the present invention in one aspect - resides in a lubricating grease eomprising (i) a predominantly paraffinic nineral oil lubrieating vehicle/ (ii~ a thickener cc~prising a ~lcium or calcium/lead ~ plex soap and (iii) from O.Ol to 10 weight percent of an organic te ~ lymer improver having a melt index of from 0.5 to 200 and ~0 (1) at least 65% by weight, of ethylene, (2) at least 5% by weight, of a se ~ d, ethylenically unsaturated monomer which is an ester of the group ~nsisting of: the ~nyl esters of saturated aliphatie earboxy~e aci~

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having 1-6 carbons; the alkyl acrylates, the alkyl methacrylates, the dialkyl maleates and the dialkyl fumarates of aliphatic alcohols having 1-6 carbons; and (3) 0.01 to 3% by weight, of a third ethylenically unsaturated monomer of the group consisting of: acrylic, methacrylic, itaconic, maleic, and fumaric acids;
:` the anhydrides of itaconic, maleic and fumaric acids; the alkyl hydrogen maleates and the alkyl hydrogen fumarates; the mono-acrylates and monomethacrylates of glycols; 2-hydroxy-3-amino-propyl allyl ether, allyl glycerol ether, divinyl glycol, 2-dimethylaminomethyl acrylate, 2-dimethylaminoethyl methacrylate and N-vinyl pyrrolidone.
In another aspect the present invention resides in a method for improving grease formation, in a process for manu-facturing a calcium complex grease in which there is incorporated : ~ -an ethylene-vinyl ester-organic acid terpolymer as an improving agent, which method comprises introducing said terpolymer to the . ~
charge of lubricating vehicle and thickening agent components ~.
prior to saponification.
DESCRIPTION OF SPECIFIC EMBODIMENTS
As stated above, the grease has three essential compo-nents, namely, the paraffinic lubricating vehicle, the thickener and the terpolymer. These will be discussed ~eparately below.

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i -3a ''' ' ' ~ ' '''' . ., ~L~5~5~4 Lubricating Vehicle This is predominantly a paraffinic lubricating stock At least 30%, generally at least 50% and preferably at least 80% by weight is a paraffinic lubricating oil. The balance of the lubricating vehicle may be a naphthenic lubrlcant but since these stocks are more expensive than paraffinic stocks, their use is economically un-favorable particularly since the present invention enables the greases to be produced wholly fron the paraffinic stocks, i.e. the lubricant vehicle is entirely a paraffinic stock. If their use is desired fQr any particular purposes, asphaltic stocks may be used in combination with the paraffinic. As will be explained below, however, it is desirable to use the paraffinic stock during the saponifications and to add the other stocks later.
If desired, non mineral oil lubricating vehicles may be blended ` with the paraffinic oil. This may be desirable if particular properties are desired in the final grease. Suitable synthetic lubricating vehicles which may be included are, for example, synthetic ester lubricants, e.g. the dibasic acid esters such as di-ethylhexyl azelate or sebacate, the hlndered polyol esters such as the neopentyl glycol esters, e.g. the ' 20 trimethylol propane and pentaerythritol esters of C6 to C10 monocarboxylic acids; synthetic hydrocarbons such as the hydrogenated olefin polymers desoribed in U.S. Patent NoO 3,149,178 to Lyle A. Hamilton et al. Mixtures of three or more lubricating vehicles may also be used, although the paraffinic mineral;oil should normally comprise at least 50% by weight of t~e lubricating vehicle in the grease.
me paraffinic stocks used in the greases will generally have a `-viscosity of from 40 to 10,000 SUS at 100F., preferably 60 to 6000 SUS
at 100F. t4 to 2000 cS at 38C, preferably 10 to 1200 cS at 38C). If a .

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minor amount of a naphthenic mineral oil is blended with the paraffinic, it too will generally have a viscosity in this range. In both cases, viscosity indexes from 30 to 100 are preferred.
The paraffinlc base stocks will normally be acid-treated, solvent-refined or hydrofinished paraffinlc oils. The various treatments to which the oils may be subjected are intended to remove the less paraffinic constikuents and~ by so doing, to raise the viscosity index. For example, solvent-refining removes the less paraffinic constituents and hydrofinishing converts the non-paraffinics to paraffinics, acid reacts with the non-paraffinics and enables them to be removed.
Thickening Agent Both calcium complex and calcium~lead complex thickeners may be used, although the former are preferred. Both types of thickener are derived from a mixture of acids and the thickeners are conveniently characterized by a description of the acids used to form the salt/soap mixtures. Since these complex thickeners invarlably contain acetate salts~
they are o~ten referred to as calcium and calcium~lead acetate complex thickeners.
.:
he acids preferably comprise a complex mixture of low, inter-~ 20 mediate and hi~h molecular weight carboxylic aclds. The molecular weights i (carbon atom content) of the acids and the proportions in which they are i .
used are as follows:
No. of Wt. Percent of total acids Acid aton~s Broad _ Preferred Low Mol. Wt. 1-6 10-60 20-45 Inter. Mol. Wt. 7-12 10-80 25-50 High Mol. Wt. 13 or more 2-75 15-50 Acetic acid is the preferred low molecular weight carboxylic acid and :
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~5~524 caprylic is a preferred intermediate wei~ht carboxylic acid. As it has an even number of carbon atoms it is conveniently available from natural sources. Naturally occurring oils are convenient sources for the high molecular weight carboxylic acids (normally C13-C36 although hi~her molecular wei~ht materials may be present). Coconut oil is a convenient source of C12-C15 acids and tallow a convenient source of Clg acids. Hydrogenated tallow (C18) acids are preferred. Candelilla wax is a source of higher (C20+) acids.
Preferred complex acid mixtures of this type are as follows (weight ~10 percent of total acids):
BroadPre~erred Acetic Acid 20-30~4~ 25 ~ Caprylic Acid 15-20~u~ 17 `' Coconut oll aclds 40-45~ ~ 43 Tallow acids 10-20 ~ 15 me tallcw acids are preferably hydrogenated to reduce resldual unsaturation.
Another preferred type of calcium or calcium/lead complex salt/soap mixture ls that which is derived ~rcm a number of high molecular weight carboxylic acids and also has a low molecular weight carboxylic acid.
Preferably a saturated and an unsaturated acid are present ln order to obtain ' satisfactory consistency in the grease. Such mixtures are made up as follows ;~ (wei~ht percent):
Broad Preferred Hi~h molecular wt. acids (Cl ~) 7~-90 80-90 ~25 Low molecular wt. aclds (C i ~) 10-30 10-20 m e high molecular weight acids are preferably a blend o~ C18 unsaturated carboxylic aclds7 e.g. oleic acid, C18 saturated carboxylic acids~ e.g.
hydrogenated tallow acids and higher (C20t) carboxylic acids. Ihe pre~erred ~ low n~lecular weight acid is acetic acid. m e prererred ranges ~or the high ,30 molecular welght aclds are as follows (weight percent o~ t~tal aclds):
~road Preferred Unsaturated C18 aclds 3~-40 30~40 Satur~at~d Clg aclds 30-90 30-50 Acids 10-30 10-20 ~s~
Another type of co~plex thickener is that biased on a mixture of low and intermediate molecular weight acids, for example, a mixture of acetic acid with capric or caprylic acid. In these complexes, the ratio of low molecular weight acid to intermediate molecular weight acid is preferably from 0.25:1 to 10:1.
me acids are converted to their respective salts and soaps by reaction with lime (in the case Or calcium thickened greases) or lime/lith3rge (PbO) (in the case Or calc~um/lead thickened greases).
; The ratio of line to litharge for the mixed base greases is preferably at least 5:1 (CaO:PbO) more preferably at least 10:1.
O Calcium complex and calcium/lead complex thickeners Or these types are described in U.S. Patent Nos. 3,170,878, 2,999,065, 2,197,263,

2,898,297 and 2,878,187, i Terpolymer ~.5 The terpolymers used in the present greases are those described .:, in U. S~ Patent No. 3,705,853 to Fau et al.

. That is, the terpolymers have a melt index of 0.5 to 200 and contain:
(1) at least 65%, by weight, of ethylene, (2) at least 5%, by ~0 weight, o~ a second ethylenically unsaturated monomer which is an ester of the group consisting of the vinyl esters o~ the lower (1-6 carbon) saturated al1phatl~- carboxylic acids, the alkyl acrylates, the aIkyl methacrylates, the dialkyl naleates and the dialkyl ~umarates of the ;~ lower (1-6 carbon) aliphatic alcohols; and ~3) 0.01 to 3Z, by weight, of .;: :
~5 a third ethylenically unsaturated monomer Or the group conslsting of acrylic, methacrylic, itaconlc, maleic and fumarlc acids; the anhydrldes ;~
Or ltaconi~, maleic and rumaric aclds; the alkyl hydrogen maleates and the alkyl hydrogen ~umarates; the m~noacrylates and monomethacrylates -.

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of glycols, 2-hydro~y-3-amino-propyl allyl ether, allyl glycerol ether, divinyl glycol, 2-dimethylaminoethyl acrylate, 2-dimethylaminoethyl methacrylate and N-vinyl pyrrolidone The preparation of these terpolymer improving agents is described in U.S. Patent 3,215,657, issued November 2, 1965.
e preferred terpolymers contain from about 20 to about 30%, by weight, of the group (2) component, i.e. the second ethylenically un-saturated monomer component, and from about 0.1 to about 1%, by weight, of the group (3) component, i.e. the third çthylenically unsaturated monomer com~onent. Representative preferred terpolymers comprise, in addition to ethylene, from about 20 to about 30%, by weight, vinyl acetate and from ` about 0.1 to about 1%, by weight, acrylic acid; from about 20 to about 30%, - by weight, vinyl acetate and from about 0.1 to about 1%, by weight, meth-; crylic acid; from about 20 to about 30~, by weight, ethyl acrylate and l 15 from about 0.1 to about 1%, by weight, acrylic acid; from about 20 to J about 30%, by weight, ethyl acryla~e and from about 0.1 to about 1~, by weight methacrylic acid; from about 20 to about 30%, by weight, methyl methacrylate, and from about 0.1 to about 1%, by weight, acrylic acid;
and from about 20 to about 30%, by weight, methyl methacrylate and from about 0.1 to about 1%, by weight, methacrylic acid.
e most preferred terpolymers comprise (i) at least 65 wt.
~- percent of ethylene, (ii) 20-30 wt. percent of vinyl acetate and ~iii) - 0.01 to 3 wt. percent of an unsaturated acid or anhydride, preferably methacrylic acid. A particularly preferred terpo~ner comprises 71.8 wt.
percent ethylene, 25 wt. percent vinyl acetate and about 0.71 wt. percent methacrylic acid.
~; The terpolymer is essential to produce the desired consistency and stability in the finished grease. In addition, it also improves ;~ the water wash-out resistance and the resistance to softening at high - .
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temperatures. The greases of the present invention are therefore characterized by hav~ng a heavier consistency than they would have in the absence of the terpolymer (if the grease is otherwise identical).
Proportions The proportion of thickener relative to the oil depends, of course, on the consistency required in the finished grease. Although experience in the past indicated that predominantly paraffin base stocks produced greases w~ich were not as firm as those produced from naphthenic base stocks (Boner, op cit pp. 384,~511), I have found that paraffinic stocks produce a grease which is ~ust as firm as that produced from naphthenic stocks with the same amount Or a given thickener. mus, the greases are characterized by a content of predominantly paraffinic lubricating oil which is not substanti.ally less than that of a naphthenic base oil required in a grease of substantially the same consistency.
, 15 The amount of thickener will, as stated above, be determined by the grade (firmness) of the grease. Consistency is normally measured . ` .
by the ASTM D 217-68 Test (Cone Penetration of Lubricating Grease) in the case of firm~bodied greases and by the Brookf~eld viscosity for semi-fluid greases.
The National Lubricating Grease Instikute has classified greases according to their consistency as measured by the worked penetration.
Penetration values for the NLGI grades are as follows:
, ~ NI~7I Grade ASTM D 217-68 (worked9 60 strokes) `~ 25 2 265-295 - o 355-385 :~ 00 . 400-430 : 000 445-475 :
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The amount of thickener needed in a grease may be calculated by reference to the amount of saponifiable fatty material. m is is used as the basis for all such calculations in this specification.
The approximate amounts of thickener used for greases of various consistencies are shown in Table 1 below.
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The figures given in Table 1 above are for a hom!ogenized grease with a calcium complex thickener derived fram a mixture Or low, inter-mediate and high molecular weight fatty acids (approx~mately 25% acetic acid3 18% cap~ylic acid, 14g high molecular weight acids, 42% coconut oil acids).
If the grease is not homogenized (as in the case with ropey-textured greases~ greater contents of thickener may be desired. For example, an NLGI Grade 0 grease of this type would contain approx~mately 7 to 15% thickener and a No. 1 Gl~de approximately 10 to 20%. The ~) figures given above are with reference to the NLGI grades. As previously mentioned, it is possible, of course, to produce greases of any desired ~ :
cons~stency by varying the amount of thickener in the approprlate 1 manner. For example a grease of the type referred to in Table 1 could have a penetration ~lgure of 240-270 at a n~xninal thickener content o~
11% o The consistency wlll also vary with the exact type of complex ~ thickener used since each di~erent complex thickener system w~ll vary i ~n lts thickening power.
- qhe amount of the terpolymer is fron 0.01 to 10 wt. percent, ~) - usually 0.1 to 5%. T!he additives will be present in their normal 2mounts.
Preparation_ The greases are prepared by the method described in my U. S. Patent . . .
;~ No. 3,904,534, issued September 9, 1975. That is, the terpolymer is ` introduced into the charge of lubricating vehicle and thicke ~ agent i; component~ prior to saponi~ication. In a typical procedure, the fatty ~j materials whlch are to form the thickener are charged to a contactor together with the terpolymer, llme (or lime and litharge~, water and oil.
Ihe charge in the cGntactor is then heated to saponify the fatty ma~erial ,, '.. `,'. ' , . .

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and so form the complex thickener. The grease is then partly dehydrated.
After saponification has proceeded to the desired extent, the partly dehydrated charge is transferred to the finishing kettle where the dehydration is completed. Cooling, addition of various additives, homogenization and final additions of lubrieating vehicle eomplete the procedure.
If a second type of lubricating vehicle is used (in addition to the paraffinie mineral oil stoek), it is added to the grease after dehydration. The paraffinie stoek is always present in the eharge to the eontaetor beeause the effeet of the terpolymer on the grease is mueh more marked when the paraffinie stock is added at this stage. Thus, if a mixed paraffinic/asphaltie grease is to be prepared, the saponifieation will be earried out with the paraffinic base stoek and the asphaltie lubrieating stoek will be added after dehydration, when the grease is brought to its final desired consistency. The viscosity of the paraffinic base stock which is in the charge to the contactor will be in the range of 40 to 2000 SUS at 100F, generally in the range of 60 to 1,000 SUS
at 100F (4 to 420 cS at 38C, generally 10 to 220 cS at 38C).
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The greases produced in this way are thicker in consistency than the greases produced by adding the terpolymer to the finishing -~
-~ kettle with an otherwise identical grease.
The additives which may be present in the greases may be added at any convenient stage. Suitable additives include rust inhibitors such as sodium nitrite, antioxidants sueh as alkylated phenolies, aromatie amines such as p~p'-dioctyl-diphenylamine and extreme pressure agents such as ehlorinated hydroearbons. Coloring materials may also be used, if desired.

~6~5~f~ifff~f4 Examples The following Examples are given by way of lllustration only.
The grease-maklng technique employed in the Examples below involves charging a contactor with appropriate amounts of fatty saponifiable materlal, lime~ litharge, water and base oil. After saponification, the soap base is discharged to a finishing kettle. In some Examples the terpolymer was added at this point whereas in other Examples it constituted a part of the original charge to the contactor. In the former cases dehydration of the soap base is concurrent with dlspersion of the terpolymer.
Cooling, addition of various additives, homogeni~ation and final addition of oil, campflete the manufacture.
e terpolymer employed in the Examples had a melt index of about 6 and contained about 71.8%, by weif~ht, ethylene, about 25%, by ` weiff~ht, vinyl acetate and about 0.71%, by weight, methacrylic acid. The amount of terpolymer was approximately 0.5 wt.% of the total grease.
The base oils employed in Examples 1 to 6 were either a 500 SUS
(100 cS) solvent-refined parafflnic neutral oil, with a V.I. of 60 or 300 SUS (70 cS~) solvent-refined paraffinic neutral oil havin~ a V.I. o~
90. The base oils employed in Examples 7-12 were either a 900 SUS (200 cS) solvenjt-refined naphtnenic neutral oil having a V.I. of 65 or a 300 SUS
(70 c~) solvent paraf~inic neutral oil having a V.I. of 90.
The thickener was either a calcium or calcium/lead acetate , :
ca~olex derived from a mixture of low, intermediate and high molecular wel~ht fatty acids of the type referred to in Table 1 above. The amount of thickener used is shown with reference to the amount of saponifiable ` fatty material.
The results are shown in Tables 2 f~nd 3 below.
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As will be apparent from Tables 2 and 3, higher amounts of fatty material or softer consistency results are encountered in the finished grease ~Ihere the terpolymer is either absent, or introduced into the finished grease contrasted with the presence of smaller amounts of i fatty material or firmer consistency results when the terpolymer is introduced in the charge to the contactor.
The effect of the terpolymer improver was investigated further by preparing two greases of similar consistencies, one with terpolymer and the other without. A solvent-refined paraffinic base stock of 300 ) SUS at 100F (70 cS at 38C) ~iscosity and 90 V.I. was used. The finished grease was tested in the extended working test (ASTM D 217-68,/Q000 strokes) and the High Temperature Churn Test both with and without water. m e High Temperature Churn Test is a modified RIV Test, a simulated rotatin~ ball bearing test. m e RIV Test is described in NLGI Spokesman, April 1955, pp. 38-43. This te~t is modifled by operation at a higher tem~erature, 93C, at 300 rpm. The test apparatus is modified by the use of a l~eavier he~d to retain the ~.~ter ~hich is mixed ~rith the grease in the boql during the part of the test in which ~ater is added.
The results are shown in Table 4 below.

Table 4 Ex~mple No. 13 14 Poly~.er amount, ~.% 0.5 ~one Fatty ~aterial, wt.% 14.0 15.7 Penetration, worked 60X 204 212 j Penetration change i a~er lO,OOOX, % 60 78 Penetr~tion chan~e after Churn Te6t at 9~C, % 10 ` 112 Penetr~t,ion ch~nge after

3 ~u m Test ~ith water at 93ac, % 114 132 .
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These results show that the yield is better and that the ~ grease has better work stability, as shown by the Extended Working Test ; and the High Temperature Churn Test, and that it also has better stability in the presence of wAter at higher temperatures.
The invention has been described with re~erence ko specific working embqdiments. It is not limited to those embodiments.
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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A lubricating grease comprising (i) a predominantly paraffinic mineral oil lubricating vehicle, (ii) a thickener comprising a calcium or calcium/lead complex soap and (iii) from 0.01 to 10 weight percent of an organic terpolymer improver having a melt index of from 0.5 to 200 and (1) at least 65%, by weight, of ethylene, (2) at least 5%, by weight, of a second ethylenically unsaturated monomer which is an ester of the group consisting of:
the vinyl esters of saturated aliphatic carboxylic acids having 1-6 carbons; the alkyl acrylates, the alkyl methacrylates, the dialky maleates and the dialkyl fumarates of aliphatic alcohols having 1-6 carbons; and (3) 0.01 to 3% by weight of a third ethylenically unsaturated monomer of the group consisting of:
acrylic, methacrylic, itaconic, maleic, and fumaric acids; the anhydrides of itaconic, maleic and fumaric acids; the alkyl hydrogens maleates and the alkyl hydrogen fumarates; the mono-acrylates and monomethacrylates of glycols 2-hydroxy-3-amino-propyl allyl ether, allyl glycerol ether, divinyl glycol, 2-dimethylaminomethyl acrylate, 2-dimethylaminoethyl methacrylate and N-vinyl pyrrolidone.

2. A grease according to claim 1 in which the grease is prepared by adding the terpolymer to the contractor charge prior to saponification.

3. A grease according to claim 1 in which the terpolymer comprises (i) at least 65 wt. percent of ethylene (ii) 20-30 wt. percent of vinyl acetate and (iii) 0.01 to 3 weight percent of an unsaturated acid or anhydride.

4. A grease according to claim 3 in which the unsatu-rated acid comprises methacrylic acid.

5. A grease according to claim 4 in which the terpolymer comprises about 71.8 wt. percent ethylene, about 25 wt. percent vinyl acetate and about 0.71 wt. percent methacrylic acid.

6. A grease according to claim 1 in which the thickener comprises a complex soap derived from a mixture of low, inter-mediate and high molecular weight carboxylic acids as follows:

Acid Wt. Percent Low molecular wt. (C1-C6) 10-60 Intermediate molecular wt. (C7-C12) 10-80 High molecular wt. (C13 or more) 2-75

7. A grease according to claim 6 in which the thickener is derived from a mixture of carboxylic acids as follows:

Acid Wt. Percent Low molecular wt. (C1-C6) 20-45 Intermediate molecular wt. (C7-C12) 25-50 High molecular wt. (C13 or more) 15-50

8. A grease according to claim 6 in which the thickener is derived from a mixture of acetic acid, caprylic acid, coconut oil acids and tallow acids, as follows:

Acid Wt Percent Acetic acid 20-30 Caprylic acid 15-20 Coconut oil acids 40-50 Tallow acids 10-20

9. A grease according to claim 1 in which the thickener comprises soap derived from a mixture of 70 to 90 wt. percent high molecular weight (C13+) carboxylic acids and 10 to 30 wt.
percent low molecular weight (C1-C6) carboxylic acids, the high molecular weight carboxylic acids comprising a mixture of satu-rated C18 carboxylic acid, unsaturated C18 carboxylic acid and higher molecular weight carboxylic acids.

10. A grease according to claim 1 in which the thickener comprises a calcium complex soap thickener.

11. A grease according to claim 1 in which the thickener comprises a calcium/lead complex soap thickener in which the ratio of calcium to lead is at least 5:1.

12. A grease according to claim 1 which has a worked penetration of from 220 to 250 by ASTM Test D 217-68 and has a thickener content of 10 to 15% based on the weight of saponifiable fatty material.

13. A grease according to claim 12 in which the thickener content is 11 to 14% based on the weight of saponifiable fatty material.

14. A grease according to claim 13 in which the thickener content is 12 to 13% based on the weight of saponifiable fatty material.

15. A grease according to claim 1 which has a worked penetration of from 265 to 295 by ASTM Test D 217-68 and has a thickener content of 8 to 13%, based on the weight of saponifiable fatty material.

16. A grease according to claim 15 in which the thickener content is 9 to 12% based on the weight of saponifiable fatty material.

17. A grease according to claim 16 in which the thickener content is 10 to 11% based on the weight of the saponifiable fatty material.

18. A grease according to claim 1 which has a worked penetration of from 310 to 340 by ASTM Test D 217-68 and has a thickener content of 4 to 9% based on the weight of saponifiable fatty material.

19. A grease according to claim 18 in which the thickener content is 5 to 8% based on the weight of saponifiable fatty material.

20. A grease according to claim 19 in which the thickener content is 6 to 7% based on the weight of saponifiable fatty material.

21. A grease according to claim 1 which has a worked penetration of from 355 to 385 by ASTM Test D 217-68 and has a thickener content of 3 to 8% based on the weight of saponifiable fatty material.

22. A grease according to claim 21 in which the thickener content is 4 to 7% based on the weight of saponifiable fatty material.

23. A grease according to claim 22 in which the thickener content is 5 to 6% based on the weight of saponifiable fatty material.

24. A grease according to claim 1 which has a worked penetration of 400 to 420 by ASTM Test D 217-68 and has a thickener content of 3 to 6% based on the weight of saponifiable fatty material.

25. A grease according to claim 1 which has a worked penetration of 445 to 475 by ASTM Test D 217-68 and has a thickener content of 2 to 5.5% based on the weight of saponi-fiable fatty material.

26. A grease according to claim 1 which has a consis-tency greater than that of an identical grease without the terpolymer improver.

27. In a process for manufacturing a calcium complex grease in which there is incorporated an ethylene-vinyl ester-organic acid terpolymer as an improving agent, the method for improving grease formation which comprises introducing said terpolymer to the charge of lubricating vehicle and thickening agent components prior to saponification.

28. A process, as defined in claim 27 wherein the vehicle of said grease comprises a paraffinic mineral lubricating oil.

29. A process as defined in claim 27 wherein the vehicle of said grease comprises a synthetic lubricating oil.

30. A process as defined in claim 27, wherein said terpolymer is present in said grease in an amount of at least 0.01% by weight.

31. A process as defined in claim 27 wherein said terpolymer is present in said grease in an amount from about 0.1 to about 5 percent by weight.

32. A process as defined in claim 27 wherein said grease composition comprises a lubricating vehicle, a grease-forming quantity of a thickening agent and a minor effective amount of an improving agent comprising a terpolymer having a melt index of 0.5 to 200 and containing (1) at least 65 percent, by weight, of ethylene, (2) at least 5 percent, by weight, of second ethylenically unsaturated monomer which is an ester of the group consisting of: the vinyl esters of saturated aliphatic carboxylic acids having 1-6 carbons; the alkyl acrylates, the alkyl methacrylates, the dialkyl maleates and the dialkyl fumarates of aliphatic alcohols having 1-6 carbons; and (3) 0.01 to 3 percent, by weight of a third ethylenically unsatura-ted monomer of the group consisting of: acrylic, methacrylic, itaconic, maleic and fumaric acids: the anhydrides of itaconic, maleic and fumaric acids; the alkyl hydrogen maleates and the alkyl hydrogen fumarates; the monoacrylates and monomethacrylates of glycols; 2-hydroxy-3-aminopropyl allyl ether, allyl glycerol ether, divinyl glycol, 2-dimethylaminomethyl acrylate, 2-di-methylaminoethyl methacrylate and N-vinyl pyrrolidone.

33. A process, as defined in claim 32, wherein said terpolymer contains from about 20 to about 30 percent; by weight of the group (2) monomer component.

34. A process as defined in claim 32, wherein the terpolymer contains from about 20 to about 30 percent by weight, of the group (2) component and from about 0.1 to about 1 percent, by weight, of the group (3) monomer component.

35. A process, as defined in claim 32, wherein the terpolymer contains from about 20 to about 30 percent, by weight, of vinyl acetate and from 0.1 to about 1 percent, by weight, acrylic acid.

36. A process as defined in claim 32, wherein the terpolymer contains from about 20 to about 30 percent, by weight, vinyl acetate and from about 0.1 to about 1 percent, by weight, methacrylic acid.

37. A process as defined in claim 32, wherein the terpolymer contains from about 20 to about 30 percent, by weight, ethylacrylate and from about 0.1 to about 1 percent, by weight, acrylic acid.

38. A process, as defined in claim 32 wherein the terpolymer contains from about 20 to about 30 percent, by weight, ethylacrylate and from about 0.1 to about 1 percent, by weight, methacrylic acid.

39. A process as defined in claim 32, wherein the terpolymer contains from about 20 to about 30 percent, by weight, methylmethacrylate and from about 0.1 to about 1 percent, by weight, acrylic acid.

40. A process as defined in claim 32 wherein the terpolymer contains from about 20 to about 30 percent, by weight, methylmethacrylate and from about 0.1 to about 1 percent, by weight, methacrylic acid.

41. A process as defined in claim 32, wherein the terpolymer has a melt index of about 6 and contains about 71.8 percent, by weight, ethylene, about 25.0 percent, by weight, vinyl acetate, and about 0.7 percent, by weight, methacrylic acid.