US2927892A - Oil dispersions of calcium acetate hydrates - Google Patents

Description

'due to the Water and the danger in any proportions.

United States- Patent 2,927,892 7 on. DISPERSIONS on CALCIUM ACETATE HYDRATES Arnold J. Moi-way, Clark, N.'J., assignor to Esso Research and Engineering Company, a corporation of Delaware N0 Drawing. Application August 6, 1957 Serial No. 676,415

8Claims. (or. 252-391 a lubricating oil compositions, it will not form stable dispersions in lubricating oil without the aid of other. agents such as: emulsifiers (for oil-water dispersions); grease thickeners, e.g. metal salts of C to C fatty acidsor other suspending aids. However, the emulsion type'dis- 'into the monohydrate.

ice

2 as sorbitan monooleate; dyes; viscosity index improvers, detergents and the like.

The calcium acetate hydrates may be preformed and then added directly to the lubricating oil in the desired proportions with stirring. Preferably, because less expensive and easier to suspend, the hydrates are formed in situ in the lubricating oil as follows: A slurry is formed of the oil and a calcium base, such as calcium hydroxide, calcium oxide, calcium carbonate, etc. When the calcium oxide or carbonate is used, a small amount of water may be added in order to furnish the water of hydration. The acetic acid is then added slowly (to prevent overheating) to the slurry while stirring. If the dihydrate is desired, then the temperature of the reaction mixture should not be allowed to exceed about 180,-200 F., as above this temperature the dihydrate tends to lose one mole of the water of hydration and is converted If the monohydrate is desired, then the reaction mixture is heated above about 180 .200 F. to form the monohydrate; This monohydrate in turn is relatively stable up to about 300 F. After I formation of the calcium acetate hydrate, other additives may then be added to the composition, after which it is persions have the disadvantages of increased corrosion ing or freezing. The presence of fatty acid salts, or other grease thickener or suspending aids are at times undesirable for certain applications due to side reactions or the formation of residues. that excellent dry (i.e. no free water) lubricating compositions containing as the sole salt component either calcium acetate monohydrate, i.e. Ca(CH COO) -H O, calcium acetate dihydrate, i.e., Ca(CH COO)-2H O, or mixtures thereof, will form stable dispersions without the aid of other suspending agents. Also, these hydrates have even better anti-wear and load-carrying ability than the anhydrous calcium acetate. Lublicants of this type are suitable for use in internal combustion engines, textile mill lubricants, and because of their acid neutralizing ability are particularly useful; for lubricating the upper cylinders of marine diesel engines operating on acid-forming fuel such as high-sulfur fuel oils, etc.

The compositions of the invention will, therefore, comprise a major proportion of "a lubricating oil and about 2 to 40, e.g., 5 to Weight percent, based on the weight of the'total composition, of eitherthe monoor dihydrate of calcium acetate, or mixtures thereof.

The lubricating oil used in the compositions of the invention may be either mineral lubricating oil or a synthetic lubricating oil. Synthetic lubricating oils which may be used include esters of dibasic acids (e.g., di-2-ethyl hexyl sebacate), esters of glycols (e.g. C Oxo acid diester of tetraethylene glycol), complexesters (e.g. the complex ester formed by reacting one mole of sebacic acid with two moles of'tetraethylene glycol and twomoles of Z-ethyl-hexanoic acid), halocarbon oils, alkyl silicates, sulfite esters, mercaptals, formals, polyglycol type synthetic oils, etc., or mixtures of any of the above Other additives may also be added to the lubricating composition in amounts of about 0.1 to 10.0 "weight ,percent or more, for example: oxidation inhibitors such ag phenyl alpha naphthylamine; corrosion inhibitors, such It has now been foundof the emulsion break- I 1 dispersions are formed cooled. The hydrates may be formed in the lubricating oil in any proportion, however, for ,plant operation, it is more economicalto form a hydrate concentrate, i.e., about 30 to 60 weight percent of the hydrate in the oil, and then to cut the concentrate back by blending with additional lubricating oil to form the final composition. Althoughnot essential, it is also desirable to homogenize either the concentrate or the'final cut back composition or both, by means of a Charlotte mill, a Manton-Gaulin homogenizer, a Morehouse mill, etc. By thus homogenizing a more uniformproduct is obtained with freedom from lumps, undispersed lime, etc.

Both'the monoand dihydrate are useful in the lubricating oil compositions. However, while excellent stable from the dihydrate, such dispersions tend to be more viscous than dispersions formed with either the monohydrate or anhydrous calcium acetate per se, and when used in relatively large concentrations, -e.g., 20 to 40 weight percent, it tends to form solid However, this is an advantage when non-fiowable lubricants are desired. The monohydrate, on the other hand, formsexcellent stable dispersions which show little tendency to solidify upon increasing temperatures, and are particularly desirable for use in equipment normally handling fluid lubricants at elevated temperatures. The anhydrous form of the calcium acetate, while readily dispersed in the'lubricating oil, during storage tends to separate fromthe lubricant and for this reason Will not form satisfactory lubricants, particularly when used in low viscosity oils.

The invention will be further understood by the following examples. r

EXAMPLE IA A base material was prepared as follows: 58.0 weight percent of a'min'eral lubricating oil SUS at 100 F.) which was a Mid-Continent phenol-extracted type mineral oil distillate and 17.0 weight percent- 0f hydrated lime were added to a kettle and mixed to form a smooth intimate slurry. Then, without external heating, 25.0 weight percent of glacial acetic acid was gradually added taking care not to allow .the temperature to rise" above 200' F. After all the acetic acid was added, the mixture 4 was allowed to cool to 150 P. where it was stirred for 4 Table l one-half hour while maintaining this temperature by Compositions ofoalcim Acetate external heating in order to ensure completion of the isp o s (Weight e cen reaction. At the end of this time the heat was turned 5 off and the reaction mixture was homogenized by passing IA 113 HA 1113 IIIA IIIB IV it through a Gaulin homogenizer operating at 6,000 p.s.i. shear ficegictargdljglacial) 25.0 25.0 5.0 4. 50 w y ra e une .0 7.0 1".0 3.4 3.06 EXAMPLE 1B Mineral oil (100 SUS at 58 8 1 10 .0 91.0 5.0 0 58.0 9.0 25 weight percent of the product of Example IA was 10 Mineral 11 so s s at dlluted with 80 weight percent of additional mineral oil Mzhllerarofi-(gfi-g 51-81 (same oil as used in IA) by simple mixing Without heat- 210 F.) 40. 63 ing. This new blend was twice passed through a Gaulin fi i l manufac 200 200 300 300 350 350 300 homogenizer operating at 6,000 p.s.i. shear. Formbfcalciuniacetate E PLE HA 15 -r t A base material was prepared using the same formula- Dihydrate- 2 Monohydrate. tion and method of preparation of Example IA except a Anhydrous Table II Properties of Calcium Acetate Dispersions IA IB IIA IIB IIIA IIIB IV 1 Appearance. Excellent Excellent Excellent Excellent Similar to Excellent Excellent smooth smooth smooth smooth Example smooth smooth grease. fluid. slemfluid. 11A. fluid. fluid. 111 Viscosity, SUS:

100 F 180.7 150.9 210 Gels 64.4 Stability:

10 days at 80 F Excellent... Excellent. days at 80 F Excellent. Centrifuge test: minutes, 1,500 r.p.m., precipitation, 0.5 1.0 5.0

weight percent. 4-ball gear spot testz' (1,800 r.p.m.10 kg.-1 hour-75 O.) 0.39 0.52 0.22-

mm. 18.5031". Almen test weight carried 14 1; 14.

1 The product of Example 1V had a V.I. of 94, a sulfated ash content of 5.57 wt. percent, and in a 120 hour Caterpillar engine test showed excellent wear reductionof the rings and good cleanliness.

2 Oil separated from the lubricant.

that the dispersion of the hydrated calcium acetate formed in situ was heated to 300F. for one-half hour. It was then passed twice through a Morehouse mill set at 0.003 clearance.

EXAMPLE IIB 20 weight percent of the product of Example LEA was added to 80 weight percent of mineral oil (same as in IA). This diluted product was passed twice through a Gaulin homogenizer operating at 6,000 p.s.i.

EXAMPLE IIIA EXAMPLE IIIB The base product formed in Example IIIA was diluted in the same manner as Example 1B.

EXAMPLE IV A base grease containing the monohydrate was formed according to the manner of Example H Aexcept that a heavier. mineral lubricating oil having a viscosity of 80 SUS at 210 F. was used. 18.00 weight percent of this base material was then diluted with 40.63 Weight percent of mineral lubricating oil having a viscosity of 55 SUS at 210 F. and 41.37 Weight percent of a mineral lubricating oil havinga viscosity of 80 SUS at 210 F. The blend was then passed through a Gaulin homogenizer operating at 6,000 p.s.i. 1

The compositions and physical properties of the above lubricants are listed in the following tables.

40 and dihydrates were superior to, the anhydrous calcium acetate in regard to wear and load-carrying ability. Furthermore, these hydrates formed very stable dispersions and gave a much smaller degree of precipitation during the centrifuge test as compared to the anhydrous form. By use of the dihydrate in relativelylargc proportions, greases may be formed, While the larger proportions of the monohydrate permit the formation of semi-fluid materials. Smaller proportions of either hydrate result in the formation of lubricating fluids. Thus, fluids, semi-fluids and greases may be produced by the method of the invention.

What is claimed is:

1. A dry lubricating composition comprising a major proportion of lubricating oil and as a sole salt component about 2 to 40 wt. calcium acetate hydrate selected from the group consisting of calcium acetate monohydrate, calcium acetate dihydrate and mixtures thereof.

2. A composition according to claim .1, containing 5 to 40 weight percent of said hydrate.

3. Acomposition according to claim 1, wherein said hydrate is calcium acetatemonohydrate.

4. A'composition according to claim 1, wherein said hydrate is calcium acetate dihydrate.

-5. A composition according to claim 1, wherein said hydrate is formed in situ by the neutralization of acetic acid with a calcium base.

6. A process forvpreparing a lubricating oil dispersion containing as the sole salt component a calcium acetate dihydratewhich comprises neutralizing acetic acid with a calcium base in the presence of water and oil while maintaining the temperature of the reaction below about 200 F.

7. A process for preparing a lubricating oil dispersion containingas the sole salt component a calciumclum mm. dihydrate according to 1115mm! of claim 2,384,551

' References Cited the file of this 15mm UNITED STATES PATENTS 2,019,051 Sullivan May 4,1937

'8 Ielmle Septll, 194$ Sproule Aug. 19, 1952 Vinograd Mar. 9, 19 54 Stillebroer et a1; May 8, 1956 Morway Dec. 9, 1958 OTHER REFERENCES KolloidQZ, Article by P.C.L. Thorn et 211., vol. 48, 113- 10 125 (1929), Trans. Faraday Soc., vol. 29, pp. 1101- Earle Mar. 3, 1942 1107 (1939), Research (London), vol. 2, p. 243 (1949).

Claims (1)

1. A DRY LUBRICATING COMPOSITION COMPRISING A MAJOR PRPPORTION OF LUBRICATING OIL AND AS A SOLE SALT COMPONENT ABOUT 2 TO 40 WT. % CALCIUM ACETATE HYDRATE SELECTED FROM THE GROUP CONSISTING OF CALCIUM ACETATE MONOHYDRATE, CALCIUM ACETATE DIHYDRATE AND MIXTURES THEREOF.