US2640812A - Grease - Google Patents

Description

Patented June 2, 1953 Swan-Finch Oil Corporation, New York, NI Y1, a corporation of New York No; Drawing.

Application March 8, 1951,

Serial .No. 214*,651

12 Claims. 1

This invention relates. to. lubricants and more particularly to grease-like lubricants containing modified. montmorillonite and another gelator serving to improvethe results obtained'by the use of montmorillonite alone.

The gelling of the organic fiuids'to form greases by modified montmorillonite, in which the sodium or part of the sodium has been replaced by a long. chain secondary amine group is known. Such greases have been introduced on the market asBentone greases. As stated in The Institute Spokesman, May 1950, the official publication oi the National Lubricating Grease Institute, page 13 Bentones" are the: reactionproducts of bentonite, or more accurately, montmorillonite, and various organic cations; Montmorillonite is ahydrous magnesium aluminum silicate with a: mioaceous structure and an exceptionally small ultimate particle size.

montrnorillonite used, for. the. production. of the Bentones istheWyoming typein whichthecation'.

is predominantly sodium.

To prepare. a Bentone; the montmorillonite. is

hydrated in a. very: dilute. dispersion to separate; the unit particles, and is purified by super-censtrifugation to. achieve complete removal; otnonclay impurities. This step is,resorted toisincemost montmorillonites' in the crude, state ;contain relatively large quantities of quartz-which, ifallowed -to-- remain, would impart an abrasive character The reactive sodium.-

to the resulting product. atoms of theiunit plateszare then. replacedzbywore ganic cations and the. product. washed. filtered, dried, etc.,.to give. the final-Bentone; Aisuitable.

cationis ammonium.

By proper choice of the organic cation the. properties. of the resulting Bentone. can be cone trolled.v Use of ashort. chain alkyl. ammonium pl tely yd op obic. and. organophilic. Bentona.

and. greatly improves the heat stability.

The characteristic of lubricating greasesmade. fromthe modified montmorillonite isthe resistance of such greases to, high temperatures. It is substantially impossibletomelt such greases: In

fact, such greases made from mineral. oil and synthetic oil resist melting when heated-beyond theignition point of such oil: a

Suchigreases are known to cata1yze rusting==0f It occurs customarily as the salt of: the moderately strong acid. The- Increasing the l0" wear of bearings because they are forced to run 2. ferrous metals. As stated .in the above-mentioned article, such Bentone; greases have weak characteristics and one of them is the lack of adequatezrust-preventive properties; another one is-- theilacki of?resistancetooxidation; Another disadvantageous characteristic. is the fact that the:

gel structure of such Bentone grease is so rigid as to preclude the release of oil from the mass regardless of temperature resulting in excessive under starved lubrication conditions;

Theusual rust inhibitorsnowgenerally'recomuse with such: Bentone greases:

reases.

The principal; object 01% thepresent. invention,

accordingly, is. toprovide. an improved Bentone grease and. grease; base inrw'hich at leastsome of.- the: above .-mentionedv difficulties are. overcome.

- Inmycopending-application-Serial No. 176,243,. filed J uly: 2.7,, 1950,. I have. described and claimed.

a lubricating composition. having. in combination as ingredients a. modified. montmorillonite as a first gelator and a second gelator selectedfrom a montmorillonite, and a. long, chain. organic salt.

gelator asmore. particularly described below.

The: invention according-1y comprises .the; novel. products, the. specific. embodiments. of which are described hereinafter by way ofv example and in accordance.v with which Inow prefer to. practice the. invention.

I have found. in. accordance. with my invention thatl may prepare, agrease or. lubricant base. by providmg acomposition containing a substantial. amountv of a, modified montmorill'onite. anda lon chainorganic salt gelator,. dispersed. in av petro,

leum lubricant; Theorganic saltgelator contains. a straight. chain or. at. least 8 carbon atoms. and itssalt-f'orming metal'is lithium,,sodium, calcium,

barium. or strontium; This organic. salt mayv be a. bar1um; strontium sodium; calcium. or lithium.

soap asfound on the market or it may be a sub.- stance having the formula where X is anallr ali' metal; R is selected from= the group consisting of methylene groups having" a carbon chain length of 1 to 8 carbon atoms and the group R1 is an aliphatic radical of a carbon chain length of 4 to 18 carbon atoms, and R2 is selected from the group consisting of hydrogen and an aliphatic radical of a carbon chain length of 4 to 18 carbon atoms; or it may be a substance having the formula o-m where M is an alkaline earth metal; R is selected from the group consisting of methylene groups having a carbon chain of 1 to 8 carbon atoms and the group R2 is an aliphatic radical of a carbon chain length of 4 to 18 carbon atoms, and R3 is selected from the group consisting of hydrogen and an amic acid radical having the formula 0 R, Lat-4H1.

These substances and the processes for making them are described and claimed in the copending application of William C. Bryant (the present applicant) and Anthony Giordano, Serial No. 80,328, filed March 8, 1949 now Patent No. 2,604,449. The substances falling under Formula (A) and Formula (B) above are derivatives of What I call amic acids and are referred to in the appended claims as amates. The soaps referred to above are found on the market and consist of the usual compositions of long chain fatty acids with the alkali and alkaline earth metals mentioned. Thus, the fatty acids with which such metals are combined may be stearic acid, tallow fatty acids, cocoanut fatty acids, cottonseed oil fatty acids and others, or may be the soaps made by combining such metals with the whole fats per se.

The greases made in accordance with my invention may contain only small amounts of the two gelators, but nevertheless the resulting grease-like product shows an improvement over the use of modified montmorillonite grease alone, namely, it has both improved rust inhibiting properties and increased lubricity. Thus, I have employed as little as 0.5% of the combined modified montmorillonite and soap or amate gelator to give a semi-fluid grease which has the properties mentioned. Even smaller amounts of the combined gelator may be employed.

The term lubricity as herein employed is well understood in the art and means the ability of the lubricant to apply a lubricating film between the moving parts. Thus, the Bentone greases lack lubricity because they are unable to give up sufficient oil from the gel structure,

, namely, syneresis does not occur, to provide the necessary lubrication and under continued use, they will tend to channel completely without release of oil.

I have found in accordance with my invention that greases formed with petroleum lubricants as herein described may be used in varying proportions, but if it is desired to maintain the unique non-melting characteristics of the modified montmorillonite grease, it is important that certain proportions of the various soaps and amates be employed with such montmorillonite in order to retain this non-melting characteristic. These proportions are indicated in the examples given below.

The following examples represent embodiments of the invention as I now prefer to practice it. It is to be understood that the examples are illustrative and that the invention is not to be considered as restricted thereto except as indicated in the appended claims.

Example 1.-(Mz':z:tures using barium soap) Percent Total gelator (composed of 81% barium stearate and 19% Bentone 34) 20 300 sec/100 F. S. U. V. (Saybolt Universal viscosity) Pale Oil The grease was made by making up the Bentone 34 grease and the barium stearate grease, followed by simple thorough blending of the greases at room temperature. The Bentone grease was made up by slurrying 20% of Bentone 34 with one half the required oil at room temperature, sheared through a mill set at 0.001 to 0.002 inch clearance. The resultant putty-like mass was cut back with the balance of the mineral oil. The 20% barium stearate grease was made up in the usual manner. These two greases were made up with the same oil, namely, the Pale Oil mentioned above. Since these greases had equivalent amounts of gelator, they were blended 01f in the cold in the following proportions: 81% barium stearate grease and 19% Bentone grease at room temperature. The resultant Bentone-barium soap grease had the following physical properties:

D/P (dropping point) ASTM-D566 (American Society for Testing Materials) F 456 Micro-penetration (Texas Method) at 77 F- 99.5

The Texas Method for determining micropenetration is well known to those skilled in the art.

Bentone 34 as employed in the above example is a modified montmorillonite produced as stated above and having as cations the secondary amine radicals (CIBH37) 2N and (Ciel-1'33) 2N formed by reacting hydrated montmorillonite with technical distearyl amine.

It will be noted that the dropping point is stated to be 456 F. In order to determine the proportions at which no dropping point occurs, tests were made using exactly the same procedure but varying the relative proportions of the barium stearate and Bentone 34 with the following results for such dropping points and also for micro-penetration:

It will be seen from the above tests that somewhere between the ratios of barium stearate to Bentone 34 of 81% to 19% and 73% to 27%, respectively, there occurs a transition point wherein the blended greases change from a grease with melting characteristic to a grease having. the non-melting characteristic.

Tests showed in each instance that the oil portion of the greases would catch fire before the grease would actually melt.

Example 2.--(Mz'a:.tures using strontium soap) The following greases were made with a total combined gelator of 20% using 80% of 300 see/- 100 F. S. U. V. Pale Oil, with the following results:

Combined Gelator Micro-Pene- D/P, ASTM Test Percent Percent D566 5. 93 at Strontium Bentone Stearate 34 81 19 461 F 63 '73 27 Non-melting" 94 61' 39 do 99 In making up the above greases, the same procedure was employed as in Example v1.

From the above data, it is to be noted that there is .a ratio of strontium stearate to Bentone 34 which will give the transition point from melting to non-melting grease as described in Example 1.

Example 3.-(Mixtures using sodium soap) The following greases were made with a total combined gelator of 20% using 80% of 75 sec./- 210 F. S. U. V. Mid-Continent Bright'stock, with the following results:

Combined .Gelator Micro-Penc- TestNo. Percent Percent b tration at Sodium 77 F.

Tallow BET-30116 Soap 34 75 .25 404 F .92 '67 33 Non-melting; '100 57 43 (lO 102 The following greases were made with the same proportion of gelator but 30% of 100 sec./- 210 F. S. U. V. Mid-Continent Bright Stock, with the following results:

Combined Gelator Micro-Pene- Test-No. Percent 13/? ASTM tration at Sodium Percent. D566 Tallow -2 Soap The following greases were made with a total combined gelator content of employing 9.0% of 100 see/210 F. S. U. V. Mid-Continent Bright Stock, with the following results:

Combined .Gelator' Micro-Pene- Test No. Percent Percent bag tration at Sodium B'entone 77 F.

Tallow Soap 25 371 F 108 67 33 369 F .117 57 43 N on-me1ting .128 46 54 .-.--d0 .120 I The process for making the above greases was the same as employed in Example 1.

From the above data, it is to be noted that there is a ratio of sodium tallow soap to B ntone 34; which will give the transition point from melting to non-melting grease as described Example 1 V I Example 4.-(Mz'a:tures usingcalcium soap) The following greases were made with a total combined gelator of 10% using 90% of 4.000 sea/100 F. S. U. V. Coastal Cylinder Stock, with the following results:

The following greases were made with a .total combined gelator content of 20% using 80% of 100 sec/100 F. S. 'U. V. Pale Oil, With the following results:

Combined Gelator Micro-Pene- .D/.P.AS.'.1.M

Test Percent Percent D566 3%? at Calcium Bentone Stearate 34 75 25 84 .67 33 57 .43 93 46 5.4 89 34 66 96 22 78 N oil-melting 86 In making up the above greases, the same procedure Was employed as in Example 1.

From the above data, it is to be noted that there is a ratio of calcium stearate to Bentone 34 which will give the transition point from melting to non-melting grease :as described in Exam-.

ple 1.

Example 5.-(Mi.ttures using lithium soap) The following greases were made with a total combined gelator content of 10%. using of of 300,sec./100 F. :8. U. 'V..Pa1e Oil, with the follow-in results:

Combined Gelator Micro-Pene- Test .No. Percent tratgon at Bentone. 77

Percent Lithium Stearate D/RASTM f 425 F; Non-melting The processfo-r making the :above greases was the same as employed in Example 1.

From .the above data, it-is to be noted that there is a :ratio of lithium .stearate to jBentone 3:4. 1

which willgive the transition point from melting to non-melting grease as described in Example-1.

7 Example 6.-(Mi.rtues using sodium amateprepared in accordance with Formula A where X is sodium, according to Serial No. 80,328)

The following greases were prepared with a total combined gelator content of 20% using 80% of 300 sec./ 100 F. S. U. V. Pale Oil, with the following results:

In making up the above greases, the same procedure was employed as in Example 1.

From the above data, it is to be noted that there is a ratio of sodium amate to Bentone 34 which will give the transition point from melting to non-melting grease as described in Example 1.

Example 7.-(Mza:tures using strontium amateprepared in accordance with Formula B above where M is strontium, according to Serial No. 80,328)

The following greases were prepared with a total combined gelator content of 20% using 80% of 150 sea/210 F. Smackover Black Oil, with the following results:

The process for making the above greases was the same as employed in Example 1.

From the above data, it is to be noted that there is a ratio of strontium amate to Bentone 34 which will give the transition point from melting to non-metling grease as described in Example 1.

Example 8.--(Miwtures using barium amateprepared in accordance with Formula B above where M is barium, according to Serial No. 80,328)

The following greases were prepared with a total combined gelator content of 20% using 80% of 300 sea/100 F. SJU. V. Mid-Continent Neutral Oil, with the following results:

Combined Gelator Micro- D/P, ASTM Test Percent Percent D566 g gg s l Barium Bentone Amate 34 60 40 392 F 110 50 50 395 F 124 40 6O Non-melting" 149 The process for making the above greases was the same as employed in Example 1.

From the above data, it is to be noted that there is a ratio of barium amate to Bentone 34 which will give the transition oint from melting to non-melting grease as described in Example 1. e

Example 9.-(Mixtures using lithium amateprepared in accordance with Formula A above where X is lithium, according to Serial No. 80,328)

The following greases were prepared with a total combined gelator of 15% using 85% of 150 sea/210 F. S. U. V. Solvent Extracted Bright Stock, with the following results:

Combined Gelator DIP, ASTM Test Percent Percent D566 gggtrir Lithium Be tone Amate 34 10a 67 10s 57 122 Yes 125 33 12s is 106 The process for making the above greases was the same as employed in Example 1.

From the above data, it is to be noted that there is a ratio of lithium amate to Bentone 34 which will give the transition point from melting to non-melting grease as described in Example 1.

It will be seen from the micro-penetration tests of the above examples that there are limitations on the ratio of soap or amate and Bentone which will give a minimum of weakening of Bentone gel structure. It is also evident that in some cases the effect is caused by the action of soap or amate on the Bentone. In the other cases, the Bentone affects the soap or amate gel structure. Also from the above data it can be seen that the amates affect the consistency and change to a greater extent than do the soaps. The effect, however, on the consistency and gel structure of Bentone by amates is more than offset by the improvement in lubricity of the.

Bentone greases. This is described below under lubricity. It is evident that the Bentone gel structure is loosened to permit more syneresis when the amates are used than when the soaps are used.

In ordinary practice, the gelator content of- FLUID-Turn GREASE (Low TOTAL Gammon CONTENT) Example 10.--(Mi:ctures using sodium soap) The following greases were prepared with a total combined gelator content of 1% using 99% of 150 sec/210 F. S. U. V. regular Solvent Extracted Bright Stock, with the following results:

Combined Gelator Consistency cl e? 's ar Her 2 Test No. Percent P m Disc-No Sodium gfgg .Added Tallow 34 Weight), Soap Secs.

9 The following greases were made up using the same ingredients as above, but with a total combined gelator content of 0.5% and 99.5% of 150 sec./216 F. S. U. V. regular Solvent Extracted Bright Stock, with the following results:

Combined Gelator Consistency at 77 F. T P (gardngrIfl v est No. ercent isc- Sodium 525%? Added Tallow 34 Weight), Soap Secs.

There is no weakening of the gel strength in this case of either gelator when mixed in any concentration in low total gelator content flu d sodium soap greases at room temperature.

The process for making the above greases wasv the same as employed in Example 1.

Example 11.-(Mi:rtures using lithium amate Prepared in accordance with Formula A above, where X is lithium according to Ser. N 0. 80,328)

The following greases were prepared with a total combined gelator content of 0.5% using 99.5% of 150 sec/210 F. regular Solvent Extracted Bright Stock, with the following results:

Combined Gelator Consistency at 77 F. (Gardner #2 DiseNo Added Weight), secs.

Test No. Percent Lithium Amate Percent B entone The following greases were made up using the same ingredients as above, but with a total combined gelator content of 1% and 99% of 150 sec./ 210 F. Solvent Extracted Bright Stock, with the following results:

It can be seen that at 77 F. for the 0.5% gelator concentration there is no diminution of gel strength, the same being true for the 1% concentration.

The process for making the above greases was the same as employed in Example 1.

of the Bentones at elevated temperatures were determined by checking Gardner Mobilometer consistencies at temperatures above 77 F., with the following results:

1% GELATOR Consistency (Gardner #2 Disc-No Added Weight) Grease at F. at F, at F.

Example 10-Test No. l 72 63V 47V Example l0=-Test No. 68 58 2 43%: Example l0-Test No. 64 55 41% Example 10Tes t No. 60% 51 37% Example 10Test No. 56% 47% i 35 0.5% GELATOR Example l0'l'.est No. 57% 49 33 Example 10-Test No. 55% 48 31 Example l0Test No, 54 45 32 Example Ill-Test No. 52 42% 31% Example l0-Test N0. 51% 42% 30 Example llTest N0. 49 33 Example llTest No. 46 32% Example llTest No. 45% 31% Example llTest No. 45% 32 Example llTest No. 45 32 Example llTest No. 42 30 Example llTest N0. 39 I 26% Example llTest N0. 39 26 Example llTest No. 38% 25% Example llTest N .0. 38 25 Example llTest N0. 38% 26% Example llTest No. 37% 25 When the above data are graphed using rectangular coordinates, it can be seen that the values fall Within the limits required for linearity. Therefore the gel strength is unimpaired at elevated temperatures as well as at room temperature.

HIGH GELATOR CONTENT GREASE Example 12.(Mia:tures using sodium amate- Prepared as in Example 6) The following greases were prepared with a total oombinedgelator content of 35% using 65% of 300 sec/100 F. S. U. V. Pale Oil, with the following results:

Combined Gelator Micro- DIP, ASTM Test lerce t Per e t D566 ig??? Sodium Bentone Amate 34 70 30 Non-melting.. 36

The process for making the above greases was the same as employed in Example 1.

Emample 13.- (Mi$tures using lithium amate- Prepared'as in Example 9) The following greases were prepared with a total combined gelator content of 35% using 65% '11 of 150 sec/210 F. S. U- V. Solvent Extracted Bright Stock, with the following results:

Examination of the data reported for Examples 12 and 13 indicates that high total gelator content greases are even more stable than greases made with lower total gelator content.

It has been found in accordance with the tests given below that the mixtures of soaps or amates with Bentone 34 improved the inhibition to rusting, as well as the lubricity as compared with the ordinary Bentone greases. The following rusting tests using the Army-Navy Grease Specification No. 25A described Humidity Cabinet, run at 100 F.i2 F. at 100 relative humidity, using the lowest concentration of soap or amate reported in the above examples, were made:

Grease Hours to Failure Blank (bare metal untreated) 4 Example 2Test No. 3 312 Example 3Test N0. 3 (20% total combined gelator with 75 sec/210 F. S. U. V. Mid-Continent Bright Stock) 401 Example 3-Test No. 4 (20% total combined gelator with 100 sec./2l0 F. S. U. V. Mid-Continent Bright Stock) 297 Example 3Test N0. 4 (10% combined total gelator with 90% of 100 sea/210 F. S. U. V. Mid-Continent Bright Stock 305 Example 4-Test No. 6 (10% combined total gelator with g;%k,000 sea/100 F. S. U. V. Coastal Cylinder 79 Example 4-Test No. 6 (20% combinedtotal gelator with 80% 100 sec/100 F. S. U. V. Pale Oil) Example 5Test No. 590 Example 6Test N0. 615 Example 7-Test N0. 410 Example 8-Test N0. 465 Example 9Test No. 521 Example l0-Test 21 2 Controls for Example 10 10% of Bentone grease with 300 sec./l00 F. S. U. V. Pale Oil 2 Example llTest 8 2 Co t-01s for Exa ple ll 10% of Bentone grease with 300 sec/100 F. S. U. V. Pale Oil 2 Example 12Test 2 over 7 Example iii-Test 2 over 700- 1 Control for Examples 12 and 13 10% of Bentone grease with 300 see/100 F. S. U. V. Pale Oil 4 Examples 10 and 11 show marked improvement in rust resistance as compared with Bentone alone even though these examples have a very low content of gelator, The increase in total gelator to 35% shown in tests of Examples 12 and 13 produces a great increase in rust inhibition.

The lubricity improvement was demonstrated by using the Falex machine made by Faville- Levalley Corporation of Chicago, Illinois. The straight Bentone grease would only carry 200 lbs. gauge, whereas the soap diluted greases carried 350 lbs., and the amates 450 lbs. gauge, in all cases.

From the above data as given in the examples and tests, it will be noted that the objectionable properties of the Bentone greases, namely, their tendency to rust, may be overcome by combining these greases with one or more of the following: barium, strontium, sodium, calcium and lithium soap greases and barium, strontium, sodium and lithium amates. I have found that these tures while preserving all of the beneficial characteristics such as high dropping point of the Bentone grease, also add the beneficial characteristics of high resistance to rusting and greatly improved lubricity.

What I claim is:

1. A lubricating composition of a petroleum lubricant, a montmorillonite modified by an organic cation, and a long-chain organic salt gelator which contains a straight chain of at least 8 carbon atoms and whose salt-forming metal is selected from the group consisting of lithium, sodium, calcium, barium, and strontium, said organic salt having the characteristic of improving the lubricity and inhibiting the rust-producing properties of the modified montmorillonite, the

- proportions of modified montmorillonite to said organic salt gelator ranging from 19-78% of said modified montmorillonite to 81-22% of said organic salt gelator.

2. A composition in accordance with claim 1 in which the combined modified montmorillonite and organic salt gelator are present in the proportion of at least 0.5%.

3. A grease compound of a petroleum lubricant and a gelator comprising not more than about 81% to 73% barium soap and not less than about 19% to 27% modified montmorillonite.

4. A grease compound of a petroleum lubricant and a gelator comprising not more than about 75% to 57% sodium soap and not less than about 25% to 43% modified montmorillonite. 5. A grease compound of a petroleum lubricant and a gelator comprising not more than about 60% to 40 lithium soap and not less than about 40% to 60% modified montmorillonite.

6. A grease compound of a petroleum lubricant and a gelator com-prising not over about 60% to 40% sodium amate and not less than about 40% to 60% modified montmorillonite.

7. A grease compound of a petroleum lubricant and a gelator comprising not over about 75% to 46% lithium amate and not less than about 25% to 54% modified montmorillonite.

8. A grease compound of a petroleum lubricant and a gelator comprising not more than about 81% to 73% barium stearate and not less than about 19% to 27% modified montmorillonite.

9. A grease compound of a petroleum lubricant and a. gelator comprising not more than about 75% to 57% neutral sodium tallow soap and not less than about 25% to 43% modified montmorillonite.

10. A grease compound of a petroleum lubricant and a, gelator comprising not more than about 60% to 40% lithium stearate and not less than about 40% to 6 0% modified montmorillonite.

11. A grease compound of a petroleum lubricant and a gelator comprising not over about 60% to 40% sodium N-lauryl sebacamate andnot less than about 40% to 60% modified montmoril- WILLIAM C. BRYANT.

References Cited in the file of this patent UNITED STATES PATENTS Name Date Jordan Nov. 28, 1950 Number

Claims (1)

1. A LUBRICATING COMPOSITION OF A PETROLEUM LUBRICANT, A MONTMORILLONITE MODIFIED BY AN ORGANIC CATION, AND A LONG-CHAIN ORGANIC SALT GELATOR WHICH CONTAINS A STRAIGHT CHAIN OF AT LEAST 8 CARBON ATOMS AND WHOSE SALT-FORMING METAL IS SELECTED FROM THE GROUP CONSISTING OF LITHIUM, SODIUM, CALCIUM, BARIUM, AND STRONTIUM, SAID ORGANIC SALT HAVING THE CHARACTERISTIC OF IMPROVING THE LUBRICITY AND INHIBITING THE RUST-PRODUCING PROPERTIES OF THE MODIFIED MONTMORILLONITE, THE PROPORTIONS OF MODIFIED MONTMORILLONITE TO SAID ORGANIC SALT GELATOR RANGING FROM 19-78% OF SAID MODIFIED MONTMORILLONITE TO 81-22% OF SAID ORGANIC SALT GELATOR.