US3182020A - Stabilized calcium acetate oil dispersions - Google Patents

Description

United States Patent 3,182,020 STABILIZED CALCIUM ACETATE OIL DISPERSHONS Robert H. Davis, Woodbury, NJ., assignor to Socony Mobil Oil Company, Kim, a corporation of New York No Drawing. Filed June 30, 1961, Ser. No. 120,938 5 Claims. (Ci. 25240.7)

The invention relates to lubricating compositions. More particularly it is concerned with the provision of stable dispersions of calcium acetate in lubricating oil, which dispersions are highly advantageous for use as lubricants per .se or as components for lubricant compositions, including fluid lubricating oils and greases.

It is known that calcium acetate when dispersed in a lubricating oil imparts desirable improvements thereto, such as load-carrying ability and anti-wear properties. Also, because of its acid-neutralizing ability calcium acetate is a particularly desirable additive for lubricating oils used in engines operated on high sulfur-content fuels, such as marine diesel engines. Simple dispersions of calcium acetate in lubricating oil, however, are unstable, the calcium acetate separating out during transportation and/ or storage of the oil composition. In order to overcome this problem and obtain insofar as possible the advantages provided by calcium ace tate, particularly in fluid lubricants such as marine diesel oils, it has been the practice to employ emulsion type oils, i.e., those formed by emulsifying a water solution of calcium acetate with lubricating oil. These emulsion oils, however, have not been entirely satisfactory. Thus, due to their water contents, they tend to increase the corrosion problem and they are unstable under the varying conditions encountered in storage and use. For example, the high temperatures encountered during storage in the engine rooms of ships tend to break the emulsion. On the other hand, under the low temperature conditions often encountered in cold climates, the aqueous phase can become frozen so that the emulsion is destroyed.

It will be appreciated that a means for providing a stable dispersion of calcium acetate in lubricating oil would be of considerable value to the art since such a single-phase oil will avoid the afore-rnentioned disadvantages of the emulsion type oil. Furthermore, the single-phase oil will, of course, have a much wider application than emulsion type oils, such as use as a crankcase oil in spark-ignition engines and regular (non-marine) diesel engines. Such a means is provided by the present invention.

It has now been found in accordance with this invention that oil dispersions of calcium acetate, which are not only highly stable but which have a number of other unexpected and outstanding properties as lubricants and lubricant additives, can be prepared by the use therein in conjunction with the calcium acetate of small amounts of certain N-acyl-substituted sarcosine compounds. Thus, it has been found that the N-acyl-substituted sarcosinecalcium acetate dispersions prepared in accordance with this invention are not only highly stable, but are excellent viscosity index improving additives for mineral lubricating oils.

It has also been found in accordance with this invention that the consistency of the dispersions provided herein can be varied according to the end use desired, i.e., they may range from fluid oils to greases, depending upon the proportions of calcium acetate and N-acyl sarcosine utilized in their preparation. Surprisingly, it has been found that the grease dispersions are formed even with small proportions of calcium acetate which, in the absence of the sarcosine compound, will not provide a grease.

assists Patented May 41', 1965 Accordingly, it is an object of this invention to provide novel, stabilized dispersions of calcium acetate in lubricating oil. It is another object to provide lubricant compositions comprising such dispersions, which compositions exhibit unexpected advantageous properties. Other and further objects will be apparent from the following detailed description of the invention.

The N-acyl-substituted sarcosines which are utilized as stabilizers for the calcium acetate oil dispersions in accordance with the invention conform to the formula:

wherein R represents an aliphatic hydrocarbon radical having from about 8 to about 24 carbon atoms and which may be either saturated or unsaturated. Typical examples of these sarcosines are the following:

N-pelargonoyl sarcosine N-undecyloyl sarcosine N-lauroyl sarcosine N-myristoyl sarcosine N-palmitoyl sarcosine N-stearoyl sarcosine N-oleoyl sarcosine N-linoleoyl sarcosine N-arachidoyl sarcosine N-behenoyl sarcosine N-hyenoyl sarcosine A number of the N-acyl-substituted sarcosines are available commercially under the tradename Sarkosyl, for example, Sarkosyl-L (lauroyl sarcosine), Sarkosyl-O (oleoyl sarcosine) and Sarkosyl-S (stearoyl sarcosine).

Either anhydrous or hydrated calcium acetate may be used in forming the dispersions of the invention. The calcium acetate may either be preformed or it may be formed in situ. When using preformed calcium acetate, the dispersion is prepared by forming a mixture of the acetate, the N-acyl-sarcosine and the base oil and stirring the mixture for a short period, say, from a few seconds up to about 30 minutes at a temperature of from about 25 C. to about 200 C. and preferably from about 50 C. to about 150 C. Although, as brought out hereinafter, stable dispersions can be formed at room temperature with only a brief initial mixing of the calcium acetate, the sarcosine compound and the oil and allowing the mixture to stand for several hours, its formation is considerably hastened by heating and stirring the mixture. Also, if desired, the mixture may be subjected to a mechanical homogenization treatment although this step is not essential.

The calcium acetate may be prepared in situ by neutralizing calcium oxide or calcium hydroxide with either acetic anhydride or acetic acid in the presence of the oil and then heating the mixture to a temperature sufiicient to remove any free water therefrom, i.e., above C. The N-acyl-sarcosine is then added and the dispersion formed as in the case of the preformed calcium acetate.

A full understanding of the invention will be had from the following examples and tests illustrating the principles and advantages thereof.

The base oils used in the examples were as follows:

Base Oil No. 1-An oil typical of those used in the formulation of gear oils composed of 82%, by weight, of SUS at 210 F. solvent-refined bright stock and 18%, by weight, of 200 SUS at 100 F. solvent-refined neutral oil.

Base Oil No. 2-An oil typical of those used in the formulation of marine diesel cylinder oils, i.e., a 60 SUS at 210 F. solvent-refined coastal stock.

Base Oil No. 3Aii oil typical of those used in compounding cross-graded motor oil, i.e., a 130 SUS at 100 F. solvent-refined parafiin oil.

Base Oil No. 4An oil typical of stocks used in metal processing oils, i.e., a 100 SUS at 100 F. solvent-refined paraifin oil.

EXAMPLE 1 Amount (parts Materials used: by weight) Calcium acetate (ctg. 6% water, i.e., approx.

/3 mol water of hydration) 10 Oleoyl sarcosine 0.5 Base Oil No. 1 89.5

Prcedure.To a slurry of the calcium acetate in ap- It will be seen that the dispersions of the examples varied in consistency from fluids to greases. Also, it is seen that Example 1, which was fluid, and Example 4, which was a grease, contained the same concentration (10%) of calcium acetate but different amounts of oleoyl sarcosine, Example 1 containing only 0.5% and Example 4 containing 2.5%. Accordingly, it is seen that varying the amounts of either the calcium acetate or the stabilizer or both, the consistency of the product dispersion can be controlled according to the end use desired.

The dispersions of all of the foregoing examples were stored at room temperature for a period of 3 months.

During this time none of them exhibited any change in clarity, consistency or homogeneity thereby manifesting their excellent stability. prolxirtrliately A of thedbasei ol il thel sarcosine we; It will be seen that in the previous examples, the ratio an t mlxture 5mm an eate Over Pan) of 2 of calcium acetate to oleoyl sarcosine varied from :1 f d f t gl g i a fh gii i t (Examplel) down to 4:1 (Example 4). In Examples 7 mam er 0 e was en a e an e mlX me to 10 which follow, the proportion of calcium acetate 6 is about 3 p t ggog g i %h 20 was further decreased providing ratios of calcium acetate f 01110861112? opera 8 T Su to oleoyl sarcosine of from 1:1 to 1:8. In these examples mg dispersion had excellent fluidity and exhibited only anhydrous Calcium acetate was used The dispgrsions & Shght haw were prepared by mixing the calcium acetate, the sarco- EXAMPLE 2 sine compound and the oil and heating the mixture with stirring to 150 C. in the course of 20 to minutes at A second dlsperslon w Wepared after the fashlor} of which point the heating was stopped and the mixture l /i excerpt l 1n i 20 33 8? 5 allowed to cool with stirring to about 90 C. The stirring acetatey 2 P 5 0 O coy Sarcosme an P 5 0 was then stopped and the material allowed to reach room Basie 011 2 homosenllatwil was temperature. The data with respect to these dispersions omitted. The resulting dispersion was a viscous fluid and 30 is Summarized in Table had y a y sllght haZe- It will be noted from Table I that here again, as with EXAMPLE 3 Examples 1 to 6, the consistency of the several disper- A dispersion was p p after the fashion of Exam sions varied with the ratio of calcium acetate to oleoyl sarcosine used. Pi ,1 but dP r t f g s??? 2 of 35 To demonstrate the effectiveness of the dispersions of 0 3 sarcQsme an 1?? u 0 Tg 1 the invention in improving the viscosity index of lubricatall of the oil was used initia y. e resu ting dispersion mg oil, the dispersions of Examplcs 7 to 10 were cut was 3 51110031 llght colored grea5eback with additional amounts of the same mineral oil EXAMPLE 4 40 (Base Oil No. 3). In general, 2%, by weight, of the p respective concentrates were diluted with 98%, by Another d1sper.SlOn.was prepared after the fashlon of Weight, of the oil. The amounts of total additive in the Example 1, but in this case along with the 10 parts of finished blends (Exam 1 11 t 15) h T M calcium acetate, 2.5 parts of oleoyl sarcosine and 87.5 H t a th th p i are g m 1 e parts of Base Oil No. 2 were used. Also, homogeniza- 5 er W1 e S6051 y m Ices o t e fims ed tion was omitted. In this case the resulting dispersion en was a smooth, light-colored grease. AS be seien from TIb1e U f disperslims of the invention are highly efiective viscosity index improvers, EXAMPLE 5 provided a proper acetatezsarcosine ratio is selected. For A dispersion was prepared after the fashion of Exam- Install? f uslflg 1:1 mm) of aceiate to ple 1, utilizing the 10 parts of calcium acetate, but in sarcosme ralses i vlscoslty Index of h base f this case 1 part of stearoyl sai'eosine and 89 parts of Base to an lmpfoveqlent of 38 points- A $lm11a1 Oil No. 4 were used and the homogenization step omitted. Improvement P 1S afforded y a 114 atlo The dispersion obtained was a thixotropic fluid and had ample Example 12 represents the Optimum inasa moderate haze. much as it provides an improvement in viscosity index of 47 points over the base oil. On the other hand, an ace- EXAMPLE 6 tatezsarcosine ratio of 1:8 (Example 14) fails to improve A preparation was carried out after the fashion of Exthe vislfosity indX WheI1 using an eflllivalefit acetate ample 5 except that here the stabilizer used was lauroyl Centfatlofl and this lack of eflectlvenfiss 15 not greatly sarcosine. The dispersion again was a thixotropic fluid altered when the concentration is increased five-fold (Exwith a moderate haze. 6O ample 15).

Table I Calcium Oleoyl Base Oil Stability, Ex. No. acetate sarcosliic No. 3 Consistency Clarity 3 months (weight (weight (weight at rm. percent) percent) percent) temp.

7 2.5 2.5 95.0 Viscous scmi- Slight haze" Stable.

solid. 8 2.5 5.0 Do. 0 2.5 10 D0. 10 2.5 20 Do.

Table 11 Cone. of Example Acetate: active Viscosity Number Composition of blend (weight percent) sarcosine materials index ratio (weight percent) 100% mineral oil 0 105 2% example 7, 98% mineral oil 1:1 0.1 143 2% example 8, 98% mineral 0 1:2 0. 152 2% example 9, 98% mineral oil. 1:4 0.25 142 2% example 10, 98% mineral oil... 1:8 0. 45 105 10% example 10, 90% mineral oil 1:8 2. 110

It is seen that the rather marked improvements in viscosity index are brought about by rather low concentrations of the active ingredients, i.e., only 0.05% of the acetate and sarcosine compound, respectively (Example 11). On this basis, significant improvements would be expected at concentrations as low as 0.01% of each material. On the other hand, concentrations above 0.05% of calcium acetate should not adversely affect the viscosity index improvement obtained, provided the proper ratio of acetate to sarcosine (1 part acetate to from 1 up to about 4 parts of sarcosine) is used.

A further unexpected advantage of the present invention is the substantial simplification of the process for preparing calcium acetate dispersions permitted by the use of the N-acyl-substituted sarcosine stabilizer. Thus, it has been found that stable dispersions of the calcium acetate can be formed with only the briefest mixing of the acetate, the oil and the stabilizer at room temperature. Thus, by simply bringing these materials together and stirring for not more than a few seconds, say, from 5 to seconds, and then allowing the mixture to stand, a homogeneous dispersion forms in a short time, i.e., from about 1 to about 2 hours. This is illustrated by the following example.

EXAMPLE 16 Ten parts, by weight, of calcium acetate containing approximately /3 mol of water of hydration, 2.5 parts of oleoyl sarcosine and parts of Base Oil No. 3 were stirred together at room temperature for 15 seconds. The mixture was then allowed to stand at room temperature and was examined periodically with the following results.

Elapsed time: Observations on mixture Initial Turbid containing particles of crystalline material. 2 hours Homogeneous, faintly t u r b id,

semi-fluid dispersion. 2 weeks No change.

It is seen from the foregoing that a stabilized homogeneous dispersion can be prepared without significant agitation, without application of heat and without mechanical homogenization, thus providing a distinct economic advantage in the preparation of calcium acetate dispersions.

It will be appreciated that the dispersions of the invention may be used per se as lubricants, or they may be blended with base oils to provide enhanced properties therein, such as load-carrying ability, anti-wear prop erties, enhanced viscosity index characteristics, etc. In general, therefore, the dispersions may contain from about 0.01% to about of calcium acetate and from about 0.01% to about 20% of the sarcosine compound, the amounts and the proportion of calcium acetate and sarcosine utilized in any one instance depending upon the end use for which the particular dispersion is intended. Also, the dispersions may be utilized in lubricant compositions containing other additives designed to provide various improving effects therein, such as detergents, antioxidants, pour point depressants, defoamants, etc.

Although the present invention has been described herein in terms of specific embodiments and examples thereof, it is not intended that the scope thereof be limited in any way thereby, but only as indicated in the following claims.

What is claimed is:

1. A lubricating composition comprising a base lubricant selected from the group consisting of lubricating oils and greases having dispersed therein up to about 50%, based on the weight of the total composition, of calcium acetate and an amount sufiicient to maintain said calcium acetate in a dispersed state of an N-acyl-substituted sarcosine compound of the formula 0 R-Ji-N-CHzC 0 OH Where R represents an aliphatic hydrocarbon radical of from about 8 to about 24 carbon atoms.

2. A lubricating composition comprising a lubricating oil having dispersed therein from about 0.01% to about 50%, based on the weight of the total composition, of calcium acetate and as a dispersion stabilizer from about 0.01% to about 20%, based on the weight of the total composition, of an N-acyl-substituted sarcosine compound of the formula where R represents an aliphatic hydrocarbon radical of from about 8 to about 24 carbon atoms.

3. A lubricating composition comprising a lubricating oil having dispersed therein from about 0.01% to about 50%, based on the weight of the total composition, of calcium acetate and as a dispersion stabilizer from about 0.01% to about 20%, based on the weight of the total composition, of oleoyl sarcosine.

4. A lubricating composition comprising a lubricating oil having dispersed therein from about 0.01% to about 50%, based on the weight of the total composition, of calcium acetate and as a dispersion stabilizer from about 0.01% to about 20%, based on the weight of the total composition, of stearoyl sarcosine.

5. A lubricating composition comprising a lubricating oil having dispersed therein from about 0.01% to about 50%, based on the weight of the total composition, of calcium acetate and as a dispersion stabilizer from about 0.01% to about 20%, based on the weight of the total composition, of lauroyl sarcosine.

References Cited by the Examiner UNlTED STATES PATENTS 2,790,779 4/57 Spivack et a1 252-515 2,841,555 1/58 Lyons et al. 252-335 2,940,932 6/60 Morway 252-405 2,927,892 3/60 Morway 252-39 2,929,783 3/60 Morway 252-405 (Other references on following page) 3 OTHER REFERENCES Geigy Surfactants, Geigy Chemical Corporation, Schwartz et a1.: Surface Active Agents, Interscience New York: P 1 and 2 felled (CQPYnght 1959-) Publishers, Inc., New York 1949, pp. 34-55 relied on. DANIEL B WYMAN, Primary Emmi-"en J. Soc. Cosm. Chem, vol. 6, No. 5, December 1955, pages 407-415, Sussman et 211., Acylated Amino Acids 5 JOSEPH LIBERMAN, ALPHONSO SULLIVAN,

in Shampoos. Exammers.

Claims (1)

1. A LUBRICATING COMPOSITION COMPRISING A BASE LUBRICANT SELECTED FROM THE GROUP CONSISTING OF LUBRICATING OILS AND GREASES HAVING DISPERSED THEREIN UP TO ABOUT 50%, BASED ON THE WEIGHT OF THE TOTAL COMPOSITION, OF CALCIUM ACETATE AND AN AMOUNT SUFFICIENT TO MAINTAIN SAID CALCIUM ACETATE IN A DISPERSED STATE OF AN N-ACYL-SUBSTITUTED SARCOSINE COMPOUND OF THE FORMULA