US2312725A - Grease and manufacture thereof - Google Patents

Description

45 7/ 7 PEA/7724 TIC/V4 (4 I I March 2, 1943. r A. J. MORWAY ErAL 2,312,725

GREASE AND MANUFACTURE THEREOF n Filed June. 10, 1940 Fiwzrza r/ e N, ar 01543 on ka-Asz 200 I o 760 N0 I20 D;wwa 72;1715211 Patented Mar. 2, 1943 UNITED STATES PATENT emce- GREASE AND MANUFACTURE THEREOF L Arnold J. Moi-way, Clark Township, Union County, and John C. Zimmer, Union, N. J., assignors to Standard Oil Development Company, a corporation of Delaware Application June 10, 1940, Serial No. 339,616

' 14 Claims.

by cooling the mixture to about 210 F. to 225 F., adding 1% to 2% of water to assist in forming the grease structure and then finishing and drawing the product at a temperature between about 200 F. and 180 F. It has also been sug gested to dissolve a fatty acid in part of the :oil, warming the solution to about 120 F. to 150 F., and then adding a suspension of hydrated lime in the remaining oil, but this process has been con-.

fined to greases made of relatively light oils, for instance, having a viscosity of about 40 to seconds Saybolt at 210 F. In the past it has been J thought impossible to prepare calcium grease containing high viscosity oils directly, and-the only I attempt to, use such high viscosity oils involved the preparation of the grease from a low viscosity oil seconds Saybolt viscosity at 210 F.)

and subsequently blending heavy oils into the re- 0 sultant finished grease after hydration. It was also necessary to have black or special grease.

making oils for this type of lubricant and these greases at best were always opaque due to the relatively large amount of water present which was used in preparing the greases and all such greases were buttery in structure, having no tendency to string out. It has been very difficult in the past to make any lime soap grease with a high viscosity oil base stock.

However, the present invention enables the use of high viscosity oils and permits the production of greases of various desired consistencies and at I cooled while stirring to F. whereupon the resultant product will have fairly high .unworked the same time obtains an unexpectedly useful result, namely. that the greases prepared do not soften when worked but in fact usually get harder when worked.

The invention comprises broadly mixing together an oil solution of the fatty acid or mixture of fatty acids and an oil suspension of hydrated lime (which may be stabilized by small amounts of lime or soda soap) at a temperature between about F.'to 200 stirring (if necessary cooling) the mixture and drawing the finished grease at a temperature below about F.,

- trial service.

preferably at a temperature not substantially above 160 F. Incarrying out this process it is,

preferred to use only part of the .oil during the soap formation step and then to add the remaining part of the oil to assist in cooling or quenching the hot grease mixture. It is alsopreferred to work and cool the finished product to even a lower temperature than indicated above because in general the further this cooling is carried the more tendency will the finished product have to harden or increase in consistency when it is subsequently worked; for instance, the grease may be made at a temperature of F. but

penetration of about 380 to 400 (A.;'S. T. M.

method) but upon working the penetration-will be reduced to about 320 or even below 300. These Accordingly, the

greases are also transparent. I v production of lubricating greaseswhich may vary from a semifluid soft grease'or a soft bodied grease which hardens to a solid lubricant on working or dispensing is of special value in automotive chassis lubrication and severe indusinvention to harden on working, suchas by passing through the usual type grease guns, is ,of particular advantage in that some garage and filling station equipment requires a lubricant that must flow under its own weight in order to be easily dispensable, but under most conditions greases of this type will not remain on the lubricated parts without drippage, while ordinary greases which are hard when unworked soften considerably on working such as encountered on passage through grease dispensing equipment. This novel grease, due to its unique features, has

all the advantages withnone of the disadvantages that ordinary greases would have under these conditions.

The oil base stock to be used in this inventio is preferably a mineral oil fraction having a viscosity of about 55-250 or more seconds Saybolt at 2l0-F., and preferably having a viscosity of about '70-'200 seconds at 210 F.- This oil can be either I a single fraction or it can ,be a blend of several different fractions, for instance, a blend ofa heavy cylinder oil, a distillate'orprop'ane deasphaltized residual bright stock having a viscosity of about 200 seconds Saybolt at 210 F. and a minor proportion of,a distillatejhaving a viscosity of about so seconds-Saybolt at 210 F. These oils should preferably be derived "from crudes or nonparaffinic type, for instancgpreferably oils derived from Coastal or Mid-Continent crudes,

The ability of the greases'of this e. g. of napht'nenic, asphaltic, aromatic or mixed paraiiinic .type, although Pennsylvania bright stock or cylinder oils are also suitable for the preparation of these greases. The fatty acid to be used may be either a single fairly pure fatty acid such as oleic acid,

st-earic, or palmitic acid, or mixture of the stock; modifying agents, such as glycerine, glycols, polyglycols, esters, etc., may also be included. I

The invention will be better understood from a considera on of the following examples which are given for llustration only and without intent various fatty acids, preferably having morethan carbon atoms, such as, for instance, a mixture of fatty acids obtained by the oxidation of parafiin waxes; also fatty acids obtained from aniof hydrated lime and itshou d be substantially freefrom any water not chemically combined as Ca(OH) 2. Also, it should be substantially free from-any particles of unslaked burned lime or carbonated lime. Although .it is preferred to use a hydrated lime which is relatively pure calcium hydroxide, a very'small amount of magnesium- The amount of lime to be used can becalculated.

from the saponification number of the fatty acids. Generally, with this procedure the finished product should contain less than about 0.75% of free acid.

of limiting the invention to the particular materials and proportions used. 7

A series of greases was prepared in which slightly difierent conditions of heating and order of mixing were used, and in which the products were drawn oil at different temperatures but the proportions used were all the same.

Per cent by weight Oleic acid 8.00 Hydrated lime 1.04

Coastal distillate (1130 vis. at 100 F.) 18.20

Coastal bright stock (200 secs. vis. at 210 A blend of the Coastal distillate and the Coastal Other known addition agents may be added to the'greases if-desired, such as, for instance, soda, potassium, barium, aluminum, lead, zinc or other grease-making soaps; polybutenes, acryloid derivatives, or other string-imparting linear hydrocarbon, or ester polymers, dyes-and oxidation inhibitors, e. g. alpha-naphthyl amine, phenol alpha-naphthyl phenol, guaiacol, or other amines =or phenols or phenolic ethers. These oxidation inhibitors may be used in concentration of about .05% to 3.0% and assist in preventing rancidity' and serve as stabilizers. I

Other addition agents may include aliphatic amines, or alkylol amines, lead soap, halogenated materials, graphite, phosphoric acid esters, sulfur or sulfur chlorine extreme pressure lubricant bases or sulfur combined into the mineral oil base bright stock in the proportions given above, has a viscosity of about 150-160 seconds Saybolt at 210 F. Thisgrease has a free acidity of 0.66%.

Aswill appear from the table herebelow, in each case the oleic acid was dissolved in some of the oil and the hydrated lime was suspended in some of the oil and then the resulting solution and suspension were mixed together to efiect the saponification reaction, in some cases the acid solution being put into the kettle first and consequently heated first before heating the lime suspension, and in other cases the reverse procedure being used, namely, heating the lime suspension first and then adding the acid solution 7 to it. This latter order of mixing is preferred as it prevents objectionable settling of the lime suspension, since the agitator in the mixing kettle can be kept stirring during the entire procedure.- It will also be noted that in some tests part of the oil was reserved for quenching the reaction mixture, i. e., for cooling the mixture from the reaction temperature down to a temperature sub stantially below that. In all cases where the temperature of drawing was below the temperature of working, the grease mixture was stirred during the cooling, but after the grease was drawn into cans or other suitable containers for storage or shipment, it was not subjected to any further mechanical working until it was. cooled down to the room temperature and also ready to be subjected to the penetration tests (made according to the regular A. S. T. M. method).

Test No.

Amt. of oil with oleic acid lst 1st 2d 2d DistilhtA 00 Bright stock 00 7 Amtbcftol :vith hyd. lime 2d 1st 1 5 a .A Bligh MM? V 22' Same as #2 67 Same as #4 100 Oil for quenching:

Distilla 0 Bri at stock 1 33 Temp, max.) of mixing (F.) 180 180 175 Tem drawing 0 0 160 130 190 Pene mtiou unwoi'ked- 390 328 380 322 7 380-400 Penetration worked 294 296 295 283 320 265 Penetration difierence 3 85 -30 -70 (aver.) 100,

1 Minus sign means decrease in penetration.

Test No. 6 represents the type of penetration characteristics obtained in prior art products where usually the penetration of the greases in creased with working at ioom temperature. In all'the other tests, i.e., Nos. 1 to 5, where the product had been cooled down from the reaction temperature substantially, before drawing, the

resulting greases decreased in penetration upon working, this decrease ranging in extent from about 20-95 units. 7

In order to emphasize more clearly the surprising results of the present invention, the penetration figures of tests 4, 5, and 6 are set forth graphically in the accompanying drawing in which the A. S. T. M. penetration (on the vertical axis is plotted against drawing temperature on the horizontal axis). This drawing shows clearly that when the grease is drawn at 190 F. the unworked penetration is substantially lower than the worked penetration, but that when. the same type of grease is cooled down to 160 F. or further on down to 130 F. (with stirring) before drawing, the resultant product when cooled down, to room temperature has an unworked penetration which is substantially higher than the worked penetration. The chart also shows that the graphs for the worked and unworked penetrations cross each other at a temperature of about 173 F. or 174 F. When this type of grease, i. e. made at 175 F. or higher, is stirred and cooled down to about 174 F. and drawn at this temperature the resulting grease will have substantially the same unworked and worked penetrations, and when cooled further before drawing the unworked penetration becomes increasingly higher and the diiference between unworked and worked penetrations becomes increasin ly reater.

As discussed previously, the greases of this in-' vention are particularly suitable for cam and automobile shackle lubrication and many other purposes where it is desired that the grease should not become thinner during working and especially where it is desired that the grease should even become harder upon working.

It is not intended that this invention be limited to any theory as to the mechanism of the operation of the present invention nor to the materials and purposes which have been given merely as illustrative, but only by the appended claims by which it is intended to claim all novelty inherent in the invention as broadly as the prior art permits.

We claim:

l. A lime soap grease comprising a major proportion of mineral oil base stock and a minor pro portion of lime soap made from proportions of a fatty acid having more than 10 carbon atoms and lime corresponding approximately to 8.00% of oleic acid and 1.04% of hydrated lime, and made at a saponification temperature of 150 to 200 F. and drawn at a temperature below 175 F., at least F. below the saponiflcation temperature, said grease having an A. S. T. M. worked penetration of at least 30 units lower than unworked.

essentially mixed base hydrocarbon-oil base stock.

havinga viscosity of about -200 seconds Say; bolt at 210 F., and comprising about 2% to 25% of a lime fatty acid soap. I

Grease according to claim 1 made from av non'paramm" the nge of bri htstock and cylinder oil.

8. A grease according to claim 1 made at a I:

temperature at below 210 F. and, after-stirring and cooling, finished and drawn at a temperature between about 160 F. to F.

9. A lime soap grease made from approximately the following proportions of materials! 1 Percent Oleic acid 8 Hydrated lim 1.04

Coastal oil distillate of about 1130 vis. at

Bright stock of about 200 secs. vis.- at

the said grease having been manufactured at a temperature of about 175 F. to 190 F., and, after stirring and cooling, drawn at a temperature besaid grease being made at a saponiflaction temperature of about 175 to about 210 F. and drawn at a temperature at least as low as F.

11. The process of making a lime soap grease with an oil 'base stock having a viscosity greater 7 than about 55 seconds Saybolt at 210 R, which comprises making a lime soap in the presence of at least part of the oil using proportions of acid and lime corresponding. substantially to 8.00% oleic acid and 1.04% hydrated lime, at a temperature of about -200 F., and drawing ,the.

grease at a temperature below about 175;F., whereby a grease is obtained having an A. S. T. M. worked penetration of at least 30 units lower than unworked.

12. The process of making a lime soap grease which comprises mixing a fatty acid with part of the oil to be used, mixing hydrated lime with f another part of the oil, using proportions 01' acid and lime corresponding substantially to 8.00% oleic acid and 1.04% hydrated lime, and reacting the two resultant mixtures at a temperature at least as high as 150 F. but not above 210 F., stirring or pumping the. grease-making ingredients and cooling to and drawing at a temperature below 175 F. at, least 15 F. below the saponfication temperature used.

13. Process according to claim 12 in which a part of the oil is used to quench the grease from the reaction temperature down to the drawing temperature.

14. The process of making a lime soap lubri- V cating grease which comprises making a suspension of hydrated lime in 9. Coastal oil distillate, stirring and heating this suspension to a temperature of about 175 F. to 200 F., adding thereto a solution of oleic acid in a Coastal oil distillate, using proportions of acid and lime corre sponding substantially to 8.00% oleic" acid and' 1.04% hydrated lime, maintaining the tempera- 6. A grease according to claim 1 made from an ture of the mixture at a. temperature between 150 F. to 200 F. until the saponification reaction is complete, adding additional Coastal oil, with stirring, to coolrithe mixture, and drawing the rej sulting grease at a. temperature between about 160 F. to 120 F., the different fractions of .oil

used having such consistencies that a blend of;

all of the oil would have a. viscosity of about 100 to 20Q.seconds Saybolt at 210 F., and said. grease having an A. S. T. M. worked penetration of at least 30 units lower than unworked.

ARNOLD J. MORWAY.

JOHN C. ZIIWMER.

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