US2491441A - Water resisting grease - Google Patents

Description

Patented Dec. 13, 1949 I. UNITED STATES PATENT OFFICE WATER RESISTING GREASE.

Richard A. Butoosk and Ernest T. White, Jackson Heights, N. Y assignoristo. SoconY-Vacuum' Oil Company, Incorporated, a corporation of New York Nojnrawingpn enM e 11 11 47, ,seriai No. mates 2 This invention relates ,to the preparation of wa e er s t g :DIQPHfifi 130 th products to a water-resistant lubricating greases. remarkable' dejgree. I

Lubricating greases are, generally speaking, Th m t ia d isnated herein as 1116179111168:

semi-solid solutions or dispersions of soaps of inates arethe salts of divalent metals of oup alkali, alkaline eartncr'neavy m'etalsjin mineral 5, I of he' table and n u lly occurr n oil. A great number of modifying materials are rosin ac e as e, P 9 1 1 being adde'dto, greases to-impar't certaindesired sylvic, and various mixtures thereof, derived service characteristics sucnas preferential wetfrom the various grades of gum rosin or of wood ting, rustproofing, load carrylngability, water rosin. These acids may be used as they occur resistance, high temperature stability, strueture f n r 1ly or may be p y r r hy r stability, etc. At the present instance,-ave are.v Numerous" examples demonstrating the efflchiefly concerned -With--the- .means.of rendering ciency. of resinates as waterproofers are given in greases water resistant. ;The importance of this the following-tables. Asa basis of judgment, we ieature is clear from the.factthatgreaseelubri- .haveuselected. the best. available tests ,for Water cated machine; parts are encountered in port inresista namely t of the ner le n e. stallations,, on ;deck ofnavy and marine vessels, known as the water absorption test, and the in steel rollin'gzmills, inwaterpumpsof all kinds, army-navy water resistancetest,which is corn-'- in mining-machiner-ypin oil-well drilling equipmonlycalled the washtest; ment, all ofwh h depend.;i, nt i oper tiemon" .Thejfo mer has bee de i n -to .determlne h the ability ofthe'grease ch-ar-getoiresist the-action amount of water which can be -worked into a of water, salt orQfresli intheforni of spray or samplejof grease to saturatiqn, and toobserve waves (sea) pressure water stream (steel-rollingthechange inconsistency of the grease caused mills andoilwelludrilling).lllQiStllrQ seepageand by theabsorbed water. Gi eas a s ns n t condensation. (underground) etc. Under the 950- more than 50% Water and'showing an increase tion of water, .a grease containing water soluble oi worked penetration notmore than about 40 soap, may swell and thin: out into a liquid which points have been considered waterproof. In view leaks out from the bearing. Other greases may ofthe very smallamount of sample used in this be lost fromithelubricatedsurfaces-mechanically test (the; original charge is 20 grams) actual debecause chimpactroi; the wateastream andap'oorl -terininations. ofpene'tration cannot be made in cohesion-ofthegg'rease particles... In either; case; accordancewith the A. S. T. M. procedure. lubricant starvation with all its consequences will! While; an arbitrary micro-penetration test could result as only exceptionalv installations. are- .bev developedfor such applications, ithas been equipped with constant-feed central greasing; gicommon 'practiceto go by visual inspection of systems; common prjactice;isi?to-chargetl'ieib'ear5i ,the hydrated. sample rejecting the liquefied and ing with as much grease as it holds and repac1 greatly softened products and. approving those it at rare intervals. swhich have softened only slightly.

The problem of rendering greasesjwaterproof;- 'Ifhe wash testfhas been developed to deteris a moregeneralone thanit may seem. at first. ,mine th percent loss or grease from a ball bearthought. It is true that some. greases,,e. g., lime ing rotated at 60Qv R. P. M. and subjected to, the .base. .and..lithium.basegareinherentlymaterre: o-washing action, of, astrearn of water. A loss of sistant; so, it may appearthat they do not need grease not more than by weight. has been any improvement in this respect. Unfortunately, considered satisfactory. the commonly used rustproofing' additives'for 1: More detailed descriptionsoi these testsfolgreases, such as mineral oil sulfonates, ruin the low. water-resisting characteristics and degrade the 45, Waterabsorption test (from Specification O S- formerly satisfactory product to a grease which 1350-C dated June 22, 1945, and covering Grease absorbs ,water; hence, ,waterproofingis neededl' ,l,especially' d v ped for low temperature and not only for soda-base and similar-greases-which--- ;an-tirust properties, to be used in lubrication of .are'emulsifi'able in waterbyvirtueof their majorT" ,or'dnance equipment): components, but also for originally Water-re BO- This test is made in the navy water absorpsistant greases the waterproofness of which; has tion apparatus which consistsof a cup 2% dia. x been afiected by modifying materials, e. g., rustv .l high and a dia. upright electric stirrer proofers and P. additives. ;.actuated by;a 1200. R. P. M. motor. A 20 gram Among the prior. art waterproofingagents; sample of grease is'placed' in the cup and one known to the inventors, the major are calcium i653 milliliter (51%) additions of water are worked stearate, zinc hydroxystearate, and zinc naphinto the grease for 2minutes. If there is no theriate, evidence of rr'eewate'r at the expiration of the 2 It has been discovered that reslnates of zinc, min t peri an ddi ional One mlof Water cadmium, magnesium an'd -calcium; addedflto a is added and the] grease is. againv worked for. 2 grease; amounts'from 0.5% to 3.0% impart '-.minutes. This operation is repeated until free 2,491,441 4 water is evident. The final reading is made TABLE I when the water cannot be worked in the grease o areas after a total of 5 minutes. Watermo fing of sod base g es Water resistance test (from Specification AN- Ewmfle 1 2 3 4 5 G-5a dated Oct. 4, 1944, and covering Grease, 5 1 high temperature, lubricating): Composition A No. 204 ballbearing shall be packed with 4 12-h drox stearic acid grants of gt'ease and clamped m tight fittmg y y per eerie. 12.60 12.00 12. 7.00 12.00 housing which allows the inner race to turn free- Steam Midnn 30" 40 2.4g 40 7. 11 01 n odium hydroxi e o. .20 2.2 .20 2.

ly, mounted on a horizontal shaft, and rotated 1. 3 on 1000 R at 600 R. P. M. A fine stream Of distilled Water, SUV 1 per cent 31,30 1.05 31,88 32.00 85.70

Oxidation Inhi itor do. 1.00 1.00 1. none none circulating at the rateof mllllllters per second, Zincresimte none M5 none 200 M0 shall be directed against the end plate Of the Cadmium resinate .do none none 0.25 none none housing from a one mm. capillary connected to 2. Properties of Grease pump taxing suction from the reservo1r of water 2 under the bearing so that it impinges on the end 280 285 40 plate one-quarter of an inch above the outer openper cenL. s0 so 25 ing of the bearing housing. Operation shall be continued for one hour when the hearing shall be A comparison of Examples 2, 4 and 5 With removed, dried at 82 C. and reweighed to deter- 20 Example 1 shows the efficiency of the Zinc mine the grease loss. This grease loss divided by resinate, While the comparison of Example 3 with the weight of the grease used in packing the bear- Example 1 demonstrates the efliciency of the ing shall .be reported as the percent grease loss. cadmium resinate.

TABLE II Waterproofing of lithium-base greases Example 6 7 s 9 10 11 12 13 14 15 Composition Lithium Stearate .per cent Mineral Oil Suh'onate do 1 Oxidation Inhibitor do Zinc Resinate d0 Zinc l2-Hydroxystearate. do Zinc Naphthenate do- Cadmium Resinate do Magnesium Resmate do.

Mineral Oil, 105 SUV 100 F. per cent Mineral Oil, 280" SUV 100 F.

per cent- Mineral Oil, 150" SUV 100 F.

- per cent" Properties of Grease Worked Penetration 250--.. 245 245 260 240 283 200 280 Water Absorption per cent 100+.. 25 25 25 100+ 40 ConsistencyoiHydrated Grease. very slightly alittle somewhat slightly fluid. softened softenedbut fluid. softer softer softer softer only retained than than than than slightly. grease original. original. original. original. structure.

1 Commercial product containing 35% H20, 40% oil and 55% sodium sulfonates.

The eiiiciency of zinc resinate is shown by Examples 10 and 12 in comparison with Examples 6 and 11, respectively. The improvement in Example 13 over Example 11 15 due to the cadmium resinate, while Example 15 illustrates the waterproofing efiect of magnesium resinate. Examples 7, 8 and 9 refer to waterproofing additives of prior art.

TABLE III Waterproofing of mixed Na-Li base greases Example 16 17 18 19 20 21 22 23 Composition Li Stearate.. Na Stearate Hydrogenated fish o Oxidation Inhibitor 1 do MFineral Oil 150" SUV A1 Stearat Properties of Grease Worked Penetration 220 267 260 280 255 270. Water Absorption ce 30 50 100+ 25 80.... 90. Consistency of Hydr d grease very fluid-.. s l i g h t l y alittle softer very fluid-- fluid only slight very soft 11 e ar 1 y s o f t e r than origsoftening. fluid.

than original. inal.

1 Oxidation inhibitor, an amine.

2 Commercial product, same as in Table 11.

Examples 17 and 18 show the waterproofing action of Cd and Mg resinates on a grease (Example 16) possessing some water resistance. Example 20 shows that Grease of Example 19 is not improved by the addition of A1 stearate, but the same grease is improved by further addi tfiiion oi 1Zn1 gesinate (Example 21). Small additions of Cd and Mg resinates (Examples 22 and 23) also show improvement over the blank,

xamp e Example.- 3 241-;- 25 26" Composition per cent- 86.0. Mg resinate do 1.0.

Properties of Greases Worked Penetration 250 253 245. Water Absorption per cent. 45 100+" 40. Consistency of hydrated grease. slightly fluid slightly softened. softened.

1 Commercial product, same as in Table II.

eresistivity comprising-g as. A mi er l.. Hhri at IiePiaisQ.

30 of metalsoaps of fatty impart the desired grease body; and in addition thereto aismalhanimmt:fromgaliout 0.2% to mineral lubricating oil, from about 10% to about 30% of metal soaps of fatty acids, sufficient to impart the desired grease body, and in addition thereto a small amount from about 0.5% to about 3.0% by weight of a resinate of a divalent metal, selected from the group consisting of zinc, cadmium, calcium and magnesium.

3. A grease composition of increased water resistivity comprising a major proportion of a mineral lubricating oil, from about 10% to about 30% of metal soaps of fatty acids, sufficient to impart the desired grease body, and in addition thereto a small amount, from about 0.2% to resinate. about 6.0% by weight of zinc resinate.

TABLE V Waterproofing of lime-base greases Example. 27 28 29 30 Composition Ga-tallow soap percent 15.0 15.0 15.0. Water -d0 2.0 2.0 2.0. Mineral Oil, 105 SUV 100 F --do 83.0 82.0 81.0. Mineral oil sulfonate 1 -do... 1.0 1.0. Zn resinate... do Ca resinate. (10-.-. 1.0.

Properties of Grease Worked Penetration 250 255 257 252. Water Absorption .-percent 10 100+ 90 55. Consistency of hydrated grease nearly same very fluid. softenedbut somewhat as original. re t aine d softened.

grease structure.

1 Commercial product, same as in Table II.

The above series of experimental greases an 4. A grease composition of increased water demonstrates the adverse effect of mineral oil sulfonates on the water resistance of a lime base grease (Example 28 vs. Example 27) and the partial restoration of the water resistance by the addition of Zn and Ca resinates (Examples 29 and 30).

In general, these improvements may be gotten by using the resinates of divalent metals of the second group of the periodic table in amounts comprising from about 0.2% to about 6.0% by weight of the finished grease. Preference is had for the resinates of zinc, cadmium, calcium and magnesium in amounts rangingfrom about 0.5% to about 3.0% by weight of the finished grease. As to the resinates themselves, the metal content thereof should not deviate more than about above or below the stoichiometric ratio.

The incorporation of the metal resinates gives rise to no problem, since they may be added either to the oil component of the grease prior to the cooking stage, or they may be added at any intermediate stage of manufacture or to the finished grease.

We claim:

1. A grease composition of increased water resistivity comprising a major proportion of a mineral lubricating oil, from about 10% to about 30% of metal soaps of fatty acids, suflicient to impart the desired grease body, and in addition thereto a small amount, from about 0.5% to about 3.0% by weight of zinc resinate.

5. A grease composition of increased water resistivity comprising a major proportion of a mineral lubricating oil, from about 10% to about 30% of metal soaps of fatty acids, sufiicient to impart the desired grease body, and in addition thereto a small amount, from about 0.5% to about 3.0% by weight of cadmium resinate.

6. A grease composition of increased water resistivity comprising a major proportion of a mineral lubricating oil, from about 10% to about 30% of metal soaps of fatty acids, suflicient to impart the desired grease body, and in addition thereto a small amount, from about 0.5% to about 3.0% by weight af magnesium resinate.

RICHARD A. BUTCOSK. ERNEST T. WHITE.

(References on following page) REFERENCES CITED UNITED STATES PATENTS Number Name Date Schmidt Nov. 4, 1930 Zimmer et a1 Mar. 22, 1938 Liehe Feb. 12, 1946 Number Number Name Date Brunstrum et al. Apr. 9, 1946 Schantz Apr. 23, 1946 Meyer Oct. 22, 1946 Morway et a1. Mar. 11, 1947 FOREIGN PATENTS Country I Date Great Britain 1892