US2937991A

US2937991A - Method of dispersing calcium carbonate in a non-volatile carrier

Info

Publication number: US2937991A
Application number: US629229A
Authority: US
Inventors: Robert L Carlyle
Original assignee: Continental Oil Co
Current assignee: ConocoPhillips Co
Priority date: 1956-12-19
Filing date: 1956-12-19
Publication date: 1960-05-24
Anticipated expiration: 1977-05-24

Description

lVIETHOD OF DISPERSING CALCIUM CARBONATE IN A NON-VOLATILE CARRIER Robert L. Carlyle, Lake Jackson, Tex., assignor to Continental Oil Company, Ponca City, Okla, a corporation of Delaware No Drawing; Filed Dec. 19, 1 956, Ser. No. 629,229

22 Claims. (Cl. 252-18) cating oil compositions for use in diesel and like internal combustion engines, at least two requirements must be met by such oils (in addition to lubricity, stability, and the like) if a high degree of engine cleanliness is to be maintained. First, the oil must possess the power to disperse insolubles formed by fuel combustion or oil oxidation, or both; and second, the oil must be capable of neutralizing acidic lacquer precursors formed by either oil oxidation or interaction of the oil with sulfur acids produced from fuel combustion, or both of these conditions.

Many attempts have been made heretofore to produce substances which possess an alkaline reserve whereby the acidic materials formed in lubricating oils during use may be neutralized. One proposed method is that described by Bergstrom in Patents 2,270,577 and 2,279,086 utilizing basic soaps. These basic soaps demonstrated a certam superiority, and further attempts were made to increase the basicity of such soaps. One of the earliest patents referring to these basic soaps or, as they were sometimes called, over-based soaps or metal complexes is McNab, 2,418,894. Other workers in this field include Griesinger et al., 2,402,325. These patentees suggested the use'of a neutralizing agent up to about 220% of the theoretical amount required for the complete neutralization of the acid from which the soap was made. The Work of Griesinger et al. was followed by Campbell and Dellinger as described in their Patent 2,485,861. These particular patentees base their disclosure on the hypothesis that minor amounts of alkaline earth metal hydroxide or carbonate can be peptized by means of an oil mahogany sulfonate. Mertes, 2,501,731, described a process whereby the normal soap is first formed and then anadditional base combined therewith by a more or less simple mixing and heating operation followed by filtration.

2,616,924, disclose a process whereby a much larger amount of metal or base may be combined with the normal soap, thus forming a complex which may be dispersed in a lubricating oil and, because of the excess metal present, possesses an alkaline reserve. Theinvention of Asseff et al. is an improvement over the Mertes disclosure in that Assefi et al. employed a so-called promoter. Generally these promoters are alkylated phenols.

Van Ess et al., 2,585,520, disclose a process for the preparation of a basic salt by first combining in an anhydrous'state the normal salt of the acidic material and an alcoholate of the desired metal. The mass is heattreated for a substantial length of time, filtered, and then Utilizing the basic disclosure of Mertes, Asseif et al.,

2 g. the alcoholate is hydrolyzed to the hydroxide for the purpose of providing a basic product.

Although the products produced by the methods deheating process over a rather extended period of time.- Another disadvantage which is even more objectionable,

from an operating standpoint is that the sizes ofthe individual particles suspended in the oil vary greatly, from extremely small particles to'particles which in many cases exceed ten microns in diameter. The larger size particles are objectionable for two reasons: (1) their presence imparts a haze to the oil, and (2) it is generally conceded that if the particles exceed five microns in diameter, the resulting product will have a certain abrasive action upon the metal bearings. Before use the product must, therefore, be filtered. Obviously, filtration increases the cost of operation, and the larger particles retained on the filter must be discarded.

It is, therefore, a principal object of the present invention to provide a process for preparing a stable dispersion of calcium carbonate in a non-volatile carrier which process obviates the disadvantages of the prior art process. It is another object of my invention to provide a highly useful mineral oil composition utilizing such dispersions. These and other objects and advantages of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, this invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative however of but a few of the various ways in which the principle of the invention may be employed.

Broadly stated, the present invention comprises a process for preparing a stable dispersion ofcalcium carbonate in non-volatile carrier compositions which comprises:-

A. Admixing under atmospheric conditions of temperature and pressure an oil soluble dispersing agent and volatile solven therefor 2. a non-volatile carrier for the dispersing agent I 3. an aliphatic alcohol solution of an oil insoluble calcium containing base formedby reaction between hydrogen sulfide and a calcium inorganic compound wherein the anion of said calcium in,- organic compound is selected from the group consisting of oxide and hydroxide radicals.

B. Condensing from such mass at atmospheric pressure an oil insoluble calcium carbonate in particles, the diameter of which are less than .25 micron, by passing carbon dioxide through such mass to convert the inorganic gas to carbonate C. Removing the residual solvents and any water present.

Before proceeding with specific examples illustrating my invention, it may be well to indicate in general the nature of the materials required in the process.

DISPERSING AGENTS Patented May 24, i960 fonate. Usually, the use of sulfonic acids is preferred for economic reasons rather than separate manufacture of a sulfonate prior to the dispersion process. By using a preformed sulfonate, it is possible to obtain compositions wherein the cation of the sulfonate dispersant is other than calcium.

Whether sulfonic acids or preformed sulfonates are used, it is desirable to avoid appreciable amounts of sulfuric acid or salts of same in the dispersant. If these contaminants are present, the final products tend to be slightly hazy and require centrifugation or filtration for clarification.

When sulfom'c acids are used, I add from about 1% to 4% times the quantity of the oil-insoluble inorganic compound than will react with the sulfonic acid, thus insuring the presence of an inorganic compound in the product as a dispersant.

In most cases sulfonic acids are purified in the presence of suitable volatile solvents, hence are customarily used in this form in the process of this invention. Solvents are desirable to reduce viscosity during processing. Suitable solvents include low molecular weight alcohols, aromatic hydrocarbons, aliphatic hydrocarbons, and the like. Specific examples include methanol, benzene, hexane, and various petroleum distillates such as naphthas, etc.

Sulfonates which are suitable are oil soluble and include alkyl sulfonates, alkaryl sulfonates, the so-called mahogany or petroleum soaps, and the like. The mahogany soaps include particularly the oil-soluble aromatic sulfonates from petroleum. Many of the aromatic sulfonates have cycloalkyl (i.e., naphthenic) groups in the side chains attached to the benzene ring. The industrial production of oil-soluble mahogany sulfonates from petroleum is well understood in the art and is described in the liaterature. Normally, the alkyl sulfonates require about 24 carbon atoms for oil solubility. The alkary'l sulfonates, however, require an alkyl portion totalling only about 18 carbon atoms. To attain the requisite oil solubility, therefore, requires that the hydrocarbon portion of the sulfonate have a molecular weight between about 350 and 1,000. Preferably, this molecular weight is between 400 and 700. Particularly useful sulfonates include postdodecylbenzene sulfonates, diwaxbenzene sulfonates, diwaxtoluene sulfonates, and poly nonyl naphthalene sulfonates; barium and calcium postdodecylbenzene sulfonates being preferred. A particularly useful sulfonate for use in my invention, because of its availability and commercial importance, is the sulfonate obtained by neutralizing postdodecylbenzene sulfonic acid which in turn is obtained by the sulfonation of postdodecylbenzene. Postdodeeylbenzene consists of monoalkylbenzenes and dialkylbenzenes in'the approximate ratio of 2:3. Its typical properties are as follows:

Specific gravity at 38 0.8649

The wax used in making the wax aromatic sulfonate is obtained from different sources of crude petroleum oil.

Various grades of parafiin wax are made with difierent melting points. The 126-128" F. (52.2-53.3 C.) melting point wax is a mixture of organic compounds with the molecular weight averaging in the range of 330-340. The average carbon content of this mixture of organic compounds will be around 24. As the melting point of the Wax decreases the carbon content of the mixture will,

average as low as 18 or a littlelower.

Other sulfonates which may be used in the'process of this invention include, for example, monoand po1y-,

NON-VOLATILE CARRIER Suitable non-volatile carriers include mineral oils, highboiling petroleum hydrocarbons, andvarious synthetic lubricants. Specific examples of suitable synthetics include aliphatic diesters (such as di-Z-ethyl hexyl azelate) silicate esters (such as hexa-Z-ethyl butoxy disiloxane) and poly allrylene glycols or their ether derivatives. In cases where the product of this invention is to be used as an additive to mineral oils, the carrier will usually be a mineral oil such as a solvent refined Mid-Continent lubricating oil of S.S.U. at 100 F. Similarly, if the product is to be used in synthetic oils, the vehicle will usually be a synthetic lubricant.

ALCOHOL SOLUTIONS OF INORGANiC BASE The suitable calcium containing base is restricted to thev reaction product between hydrogen sulfide and calcium hydroxide, its hydrates, and calcium oxide. The exact chemical nature of this reaction product is uncertain owing to side reactions but the principal ingredient is believed to be calcium sulfhydrate.

Only a few aliphatic alcohols are suitable for'use in the process of my invention because of limited solubility for the reaction product between hydrogen sulfide and calcium hydroxide or calcium oxide. These include alcohols of the aliphatic primary series wherein the number of carbon atoms varies from 1 to 6. Of these alcohols, I generally prefer methanol, because itis available at a more economical price than the otheralcohols; and furthermore it may be more easily removed from the final product.

The process may be carried out using anhydrous alcohols and other reactants or in the presence of water. The fact that water can be tolerated is advantageous under certain conditions because many times commercial products cannot be obtained in an anhydrous condition; furthemore, the reaction between hydrogen sulfide and calcium hydroxide or calcium oxide causes a certain amount of water to be formed. In addition, if the surface active agent is added as an acid, a certain amount of water willbe formed by the neutralization reaction.

The aliphatic alcohol and the calcium hydroxide or calcium oxide may be admixed at room temperature, but should be cooled before reacting with hydrogen sulfide. Thispractice is desirable because the reaction .is exothermic and the product is unstable at elevated temperatures. In practice, I pr'e-cool the aliphatic alcohol slurry of calcium hydroxide or calcium oxide to a temperature of 59? F. or below before admitting hydrogen sulfide to the mixture. Cooling is normally continued throughout the reaction and the-hydrogen sulfide addition rate is adjusted so that the'temp'eratu'reof-the reaction mass does not exceed 115 F. As the lime or calcium hydroxide is consumed, the heat of reaction subsides and the reaction mass is cooled to a temperature of 53 F. or below. At this point it is necessary to filter the aliphatic alcohol solution of the calcium inorganic base produced by this reaction in order to remove unreacted solids and/or solid byproducts.

The filtered reaction product is added with agitation to the dispersing agent, solvent, and non-volatile vehicle. The resulting mass is then blown with CO until complete conversion to calcium carbonate is achieved. This is normally indicated by the absence 'of hydrogen sulfide in the efiluent gas stream when tested with moistened lead acetate paper. Following carbonation, the volatile solvents and water are normally removed by evaporation. The evaporation of the solvents may be caused by the application of heat or they may be removed by the application of a vacuum, in which case it is not necessary to heat the mixture above room temperature. After the solvents have been removed, the product is optically bright. Neither centrifuging nor filtering is necessary.

All of the base numbers of the products of this invention were determined by the acetic acid titration method which utilizes glacial acetic acid as the solvent and a solution of perchloric acid in glacial acetic acid as the titrant. The method is especially adapted for determinations of this type, since equilibria are obtained rapidly. The procedures for carrying out acetic acid titrations are generally outlined in Analytical Chemistry, vol. 23, No. 2, February 1951, page 337, and vol. 24, No. 3, March 1952, page 519.

In order to disclose the nature of the present invention still more clearly, the following illustrative examples will be given in which parts used are parts by weight. In the examples the numerical value preceding pale oil designates the S.S.U. value at 100 F.

Example 1 One hundred and six parts of calcium hydroxide was added to six hundred parts of methanol and the resulting slurry cooled to 59 F. This slurry was blown exhaustively with hydrogen sulfide during which time the temperature was not allowed to rise above 115 F. When the temperature of the reaction mass was reduced to 43 F. by external cooling, the intermediate product was filtered to remove unreacted solids. The product from this reaction was a clear dark green solution having a base number of 192 and an analysis of 6.8 percent calcium and 13.2 percent sulfur. This intermediate was essentially stable when stored for 8 hours in a closed container at room temperature, and for more than 30 days when stored in a closed container at 34 F. Three hundred parts of this product was admixed at room temperature with a solution consisting of 400 parts of a postdodecylbenzene sulfonic acid solution in naphtha (sulfonic acidity=0.510 milli-equivalent per gram, naphtha content 68 weight percent), 312 parts of 170 pale oil, and 600 parts of benzene. Carbon dioxide was passed at room temperature through the resultant mixture until no hydrogen sulfide was detectable in the elfiuent gas stream. The mass was then agitated while the temperature was gradually raised to 302 F. to remove the volatile solvents and water. The resulting product was a bright liquid, had a base number of 105, and analyzed 4.11 percent calcium and 1.69 percent sulfur.

Example 2 Forty-eight parts of calcium oxide was added to 600 parts of ethanol and the resulting slurry cooled to 50 F. This slurry was blown with hydrogen sulfide during which time the temperature was not allowed to rise above 109 F. When the temperature of the reaction mass was reduced to 53 F. by external cooling, the intermediate was filtered. The product from this reaction had a base number of 107 and analyzed 3.8 percent calcium and 7.3

Example 3 The procedure of Example 2 was followed with the exception that the aliphatic alcohol used was n-butanol. The base number of the intermediate product was 43. Three hundred forty parts of the intermediate product was admixed with one hundred parts postdodecylbenzene sulfonic acid solution (sulfonic acidity=0.51 milli-equivalent per gram, naphtha content 68 weight percent), 60 parts of 170 pale oil, and 175 parts of benzene. This mixture was treated as illustrated in the procedure of Example 2. The final product was a bright fluid with a base number of 64.

Example 4,

The procedure of Example 3 was followed with the exception that the aliphatic alcohol used was isobutanol. The base number of the intermediate product was 40. The final product from the intermediate was a bright fluid and had a base number of 61.

Example 5 The procedure of Example 3 was followed with the exception that the aliphatic alcohol used was n-hexanol. The base number of the intermediate product was 37. The final product from this intermediate was a bright fluid and had a base number of 59.

Example 6 Que hundred ninety-two parts of calcium oxide was added to 3,000 parts of methanol and the resulting slurry cooled to 55 F. This slurry was blown exhaustively with hydrogen sulfide during which time the temperature was not allowed to rise above F. When the temperature of the reaction mass was reduced to 43 F. by external cooling, the intermediate product was filtered. The product from this reaction was a clear dark green liquid that had a base number of 105 and analyzed 3.75 percent calcium and 7.21 percent sulfur. Twenty-six hundred parts of this product was admixed with 1345 parts of a postdodecylbenzene sulfonic acid solution (sulfonic acidity=0.61 milli-equivalent per gram, naphtha content 68 weight percent), 1540 parts of pale oil, and 2600 parts of benzene. Carbon dioxide was passed through the mixture until no hydrogen sulfide was detectable in the effluent gas stream. The mass was then agitated and the temperature gradually increased to 302 F. to remove the volatile solvents and water. The reaction mass was blown with carbon dioxide for 15 minutes at this temperature to facilitate residual solvent removal. The resulting product was a bright fluid having a base number of 98, and analyzed 4.06 percent calcium and 1.65 percent sulfur.

Example 7 The procedure of Example 6 was followed with the exception that after removal of the solvents the mix-.

Example 9 The procedure of Example 6 was followed up to and including the intermediate preparation, however, one change was made in the material charge used to prepare the final product. This change consisted of using 3514 parts of n-pentane as the volatile solvent. Following removalfo hydrogen sulfide by blowing the reaction mass with carbon dioxide, the solvents were removed from the'mixture by the application of a high vacuum. The maximum temperature attained during the removal of solvents was 109 F. and the minimum pressure was .15 mm.-of mercury. The resulting product was abright fluid, had a base number of 98', and analyzed 4.06 per cent calcium and 1.66 percent sulfur.

Example 10 A mixture consisting of 1611 parts of postdodecylbenzene sulfonic acid solution (sulfonic acidity 0.75 milli-equivalent per gram, 66 weight'perccnt naphtha), 3000 parts benzene, and 3000 parts of a methanolic solution of the reaction product between calcium oxide and hydrogen sulfide having a base number of 109 was blown with carbon dioxide until hydrogen sulfide evolution was complete. After carbonation 1737 parts of hexa (2-cthyl butoxy) disiloxane was added to the reaction mass. The procedure of Example 6 was followed in removing the volatile solvents. The resulting product was a bright fluid, had a base number of 102, and analyzed 4.37 percent calcium and 1.48 percent sulfur.

Example 11 A mixture consisting of 1345 parts of postdodecylbenzene sulfonic acidsolution (sulfonic acidity 0.61 milli equivalent per gram, 68 weight percent naphtha), 2600 parts of benzene, and 2600 parts of a methanolic solution of the reaction product between calcium oxide and hydrogen sulfide having a base number of 100 was blown with carbon dioxide until hydrogen sulfide evolution was complete. After carbonation 1543 parts of di-Z-ethyl hexyl azelate was added to the reaction mass. The procedure of Example 6 was followed in removing the volatile solvents. The resulting product was a bright liquid, had a base number of 98, and analyzed 4.06 percent calcium and 1.65 percent sulfur.

Example 12 A mixture consisting of 200 parts of ethylene diamine dinonyl naphthalene sulfonate (50 percent active in mineral oil) available under the trade name of Na Sul EDS, 250 parts of benzene, 100 parts of 170 pale oil,

and 230 prats of a methanolic solution of the reaction product between calcium oxide and hydrogen sulfide haveasiest ing a base number of 11'8'was blow with'carbon'dioxid until hydrogen sulfide evolution was complete. The can bonatcd product was then treated as in Example 6. The final product was a bright fluid, and had a. base numbe of 78. v

Example 14 I The procedure of Example 13 was repeated with the exception that 200 parts of neutral barium dinonyl naphthalene sulfonate (50 percent active in mineral oil) available under the trade name of Na Sul BSN was employed instead of Na Sul EDS." The final product was a bright fluid and had a base number of 81.

Although the finished product comprising the oil,the surface active agent, and the inorganic compound appears to the naked eye to be a true solution, a careful examination shows that the inorganic compound exists as a dispersoid in the other components. For example, election micrographs indicate that the average diameter of the dispersed particles range from about 0.007 to less than 1 micron with the greater portion of the particles less than 0.03 micron in diameter. The products of Examples 6 to 9, inclusive, were subjected to infrared examination. This examination showed the presence of an alkaline earth metal sulfonate and an alkaline earth. metal carbonate. Obviously, since the only alkaline earth metal employed in the preparation of these products was calcium, the presence to calcium carbonate as a dispersoid in the composition is indicated.

Lubricating compositions were prepared utilizing the product prepared in accordance with the various examples listed herein. Since the results using the various compounds are very similar, a lubricating oil composition using the product of Example 6 will be given for illustrative purposes. In preparing the compounding lubricating oil, suitable and preferred ranges of the different components vary as follows: the product of Example 6, l to 20 percent, 2 to 6 percent; the calcium-barium phenolate sulfide, 0.25 to 3 percent, 0.75 to 2 percent; metal dithiophosphate, 0.3 to 3 percent, 0.75 to 2 percent; methyldichlorostearate, 0.1 to 1 percent, 0.25 to 0.75 percenL respectively; and sufiicient lubricating oil make percent. The calcium-barium phenolate sulfide, the metal dithiophosphate, and the methyl dichlorostearate are well-known commercially available materials which have been found to be compatible with my calcium carbonate dispersion. The calcium-barium phenolate sulfide serves as an oxygen inhibitor, the metal dithiophosphate serves as a metal deactivator to reduce corrosion and to minimize metal-catalyzed oxidation of the lubricating composition. The methyl dichlorostearate enhances the oiliness and film strength of the lubricant.

The oil base with which the foregoing additivesare blended is preferably of a high viscosity index and highly refined mineral lubricating oils blended to the various SAE viscosity number requirements. For example, the oil blends which have been used in producing the im proved lubricating compositions of this invention may be prepared from Mid-Continent solvent refined and distillation oil fractions to provide a viscosity index of about 98 and a sulfur content not exceeding about 0.1 percent.

The character of the base oil is such that with the added components above described, the finished composition should have a base numberof at least about 2.0 and preferably not less than about 3.0, thus providing an engine lubricant with an actively available alkaline reserve for neutralizing service-developed corrosively acidic oxidation products.

These lubricating compositions may also have added thereto, as is commonly done, an antifoaming agent, a pour point depressant, a viscosity index improver, all of which have been found generally compatible in the foregoing described lubricating compositions.

' An oil composition of SAE 10-W viscosity prepared in. accordance with this invention contained the following:

Additives:

4.0 parts of the dipersed-CaCO; sulfonate detergent of Example 6 1.0 part of Ca-Ba phenolate sulfide 1.25 parts of' Zndi (alkyl phenyl) dithiophosphate 0.40 part methyl dichlorostearate Mineral oil base:

8.16 parts neutral 100 pale oil 91.84 parts neutral 170 pale oil The foregoing lubricating composition and the base oil blend without additives were run in a Chevrolet L-4 test under the following engine conditions:

Sp r.p.m 3150 Lo H P 30 Oil sump temperature F-.. 280 Water jacket temperature F 200 Additives:

500. weight percent of the disposed CaCO sulfonate detergent of Example 6 1.25 weight percent zinc di (alkyl phenyl) dithiophosphate .001 weight percent di methyl poly siloxane Mineral oil base:

8.16 weight percent neutral 100 pale oil 91.84 weight percent neutral 170 pale oil The foregoing lubricating composition and the base oil blend were run in a four-cylinder Cub engine (Internationals light tractor engine adapted to a test stand) under the following test conditions:

Speed r.p.m.... 2500 T nad H P 6,5 Oil sump temperature F 280 Water jacket temperature F 200 Running tim urs 36 After completion of the test the engines were disassembled and the parts inspected and assigned demerit ratings on their condition. The lower the total demerit ratings, the better is the general engine condition and the oil performance. A rating below 10 is considered to be excellent and a rating between 10 and is good. Corrosion is also measured by weighing the bearing shells before and after the runs. A loss due to corrosion of less than 0.05 gram is considered satisfactory. The results of this engine test utilizing my new additive showed a total demerit rating of 8.5 divided as follows: piston skirts 1.0, varnish 4.5, sludge 1.5, and carbon 1.5. The average one half bearing weight loss was 0.0065. gram. The base oil blend used in the foregoing lubricating composition had a total demerit rating of 18.0 divided as follows: piston skirts 2.0, varnish 10.5, sludge 2.5, and carbon 3.0. The average one half bearing weight loss was 0.1891 gram.

The foregoing lubricating composition was also tested in diesel engines using fuel containing 1 percent sulfur. The use of high sulfur fuels greatly accelerates the formation of piston ring and skirt deposits, hence shortening the running time required for detergent evaluation.

The engine used for this evaluation .wasa ;Witte diesel run under the following operating conditions:

' The condition of the piston is examined upon completion of the run, and assigned a demerit rating. A Witte piston rating below 8 is considered to be excellent. Those between 8 and 15 are considered to be good to fair, and indicate satisfactory performance. A rating above 20 indicates unsatisfactory performance. In this test the engine utilizing my new additive in the previously described lubricating oil composition showed a demerit rating of 3.0 (varnish 2.5, carbon 0.5).. The nearest competitive oil had a demerit rating of 9.0 (varnish 5.0, carbon 4.0).

As pointed out above, neither is involved heat treatment nor filtration of the final product necessary in the preparation of the product of my invention as contrasted to the process of the prior art. These facts are brought out by Examples 6 through 9, inclusive As for example, Example 7 is a duplicate of Example 6 with the exception that the product of Example. 7 was filtered. The final products obtained ineach example were very similar, and photographs of the products taken at a magnification of 21,000 diameters showed them to be practically identical. Example 8 was also a duplicate of Example 6 with the exception that one percent water was added to the composition prior to carbonation. Again the final products were practically identical and photographs taken at a magnification of 21,000 diameters showed them to be identical. The procedure used in Example 9 was the same as that employed in Example 6 except that the solvents were removed under vacuum which made it possible to carry out the entire procedure at a maximum temperature of 109 F. I Again the product obtained was similar to the product obtained in Example 6. These examples show three things: (1) filtraber and-the amount of calcium present in excess over that present in the oil soluble dispersing agent alone. Tabulated below are data showing this relationship in dispersions of calcium carbonate in a non-volatile carrier wherein the base number varies from 30 to 125. In all cases the ratio of neutral calcium postdodecylbenzene sulfonate to non-volatile carrier was maintained equivalent to that of a, base number product.

Basic Calcium B.N. Percent Basic Percent Neu- (Percent of Calcium tral Calcium Neutral Calcium) This application is a continuation-in-part of my copending application, Serial No. 362,970,. filed June 19, 1953, now abandoned.

While particular embodiments of the invention have been described, it will be understood, of course, that the invention is not limited thereto since many modifications may be made, and it is, therefore, contemplated to cover by the appended claims any such modifications as fall within the true spirit and scope of the invention.

spam-9i "The invention having thus been described, what is claimed and desired to be secured by Letters Patent is:

1. The process of forming a stable dispersion of calcium carbonate in a non-volatile carrier which comprises:

A. Admixing under atmospheric conditions of temperature and pressure (1) an oil soluble dispersing agent selected from the class consisting of sulfonic acids, metal sulfonates, ammonium sulfonates, and amine sul- -fonates wherein the molecular weight of the hydrocarbon portion of said dispersing agent varies from 350 to 1000 a volatile hydrocarbon solvent for said oil soluble dispersing agent a non-volatile carrier selected from the class consisting of mineral lubricating oils and synthetic lubricants for said oil soluble dispersing agent an aliphatic alcohol solution wherein the alcohol contains from 1 to 6 carbon atoms, of an oil insoluble calcium inorganic base consisting of the reaction product between hydrogen sulfide and a calcium inorganic compound wherein the anion of said compound is selected from the group consisting of oxide and hydroxide radicals and characterized further in that the amount of said inorganic base varies from about 1% to 4% times that required to reactwith the sulfonic acid where this material is' used as dispersing agent and V2 to 3% times the number of chemical equivalents of the dispersing agent where said dispersing agent is a salt of a sulfonic acid Condensing from the resulting mixture at atmospheric pressure an oil-insoluble calcium carbonate in particles, the diameters of which are less than 0.25 micron, by passing carbon dioxide through said mix- .ture to convert the excess calcium inorganic base to carbonate, and then C. Removing the residual solvents by evaporation.

2. The process of claim 1 wherein the oil soluble dis persing agent is a sulfonic acid wherein the hydrocarbon portion of said sulfonic acid has a molecular weight between 400 and 700.

3. The process of claim 1 wherein the oil soluble dispersing agent. is postdodecylbenzene sulfonic acid.

4. The. process of. claim 1 wherein the oil soluble dispersing agent is: an alkaline: earth metal postdodecyl benzene sulfonate.

5. The process of claim 1 wherein the oil solubledispersing, agent is barium postdodecylbenzene sulfonate.

. 6. The process of claim 1 wherein the oil soluble dispersing agent is calcium postdodecylbenzenesulfonate.

7. The process of claim 1 whereinthe non-volatilecarrier is a mineral lubricating oil.

8. The process of claim 1 wherein the non-volatile carrier is a synthetic lubricating oil.

9. The process of claim 1 wherein the non-volatile carrier is di-iso-octyl azelate.

10. The process of claim 1 wherein the non-volatile carrier is hexa(2-ethylbutoxy)disiloxane.

11. The process of claim 1 wherein the aliphatic alcoholic solution is a methanolic solution.

12. The process of claim 1 wherein the aliphatic alcoholic solution is an ethanolic solution.

13. The process of claim 1 wherein the aliphatic alcoholic solution is a n-butanolic solution.

14. The process of claim 1 wherein the alcoholic solution is an isobutanolic solution.

15. The process of claim 1 wherein the alcoholic solution is a n-hexanolic solution.

16. The process of claim 1 wherein the calcium inorganic compound is calcium oxide.

17. The process of claim 1 wherein the calcium inorganic compound is calcium hydroxide.

18. The process of claim 1 wherein the oil-soluble dispersing agent is a metal sulfonate and the hydrocarbon portion of said sulfonate has a molecular weight between 400 and 700.

19. The process of claim 1 wherein (1) the dispersing agent is postdodecylbenzene sulfonic acid, (2) the nonvolatile carrier is a mineral lubricating oil, and (3) the alcoholic solution of an oil-insoluble calcium inorganic base is a methanolic solution.

20. The process of claim 1 wherein (1) the dispersing agent is an alkaline earth metal postdodecylbenzene sulfonate, (2) the non-volatile carrier is a mineral lubricating oil, and (3) the alcoholic solution of an oil-insoluble calcium inorganic base is a methanolic solution.

21. The process of claim 1 wherein 1) the dispersing aliphatic aliphatic agent is postdodecylbenzene sulfonic acid, (2) the mm volatile carrier is a synthetic lubricant, and (3) the alcoholic solution of an oil-insoluble calcium inorganic base is a methanolic solution.

22. The process of claim 1 wherein (1) the dispersing agent is an alkaline earth metal postdodecylbenzene sulfonate, (2) the non-volatile carrier is a synthetic lubricant, and (3) the alcoholic solution of an oil-insoluble calcium inorganic base is a methanolic solution.

References Cited in the file of this patent UNITED STATES PATENTS 2,079,051 Sullivan et al'. May 4, 1937 2,413,311 Cohen Dec. 31, 1946 2,417,428 McLennan Mar. 18, 1947 2,501,732 Mertes Mar. 28, 1950 2,585,520 Van Ess Feb. 12, 1952 2,676,925 Lindstrom Apr. 27, 1954

Claims

1. THE PROCESS OF FORMING A STABLE DISPERSION OF CALCIUM CARBONATE IN A NON-VOLATILE CARRIER WHICH COMPRISES: A. ADMIXING UNDER ATMOSPHERIC CONDITIONS OF TEMPERATURE AND PRESSURE (1) AN OIL SOLUBLE DISPERSING AGENT SELECTED FROM THE CLASS CONSISTING OF SULFONIC ACIDS, METAL SULFONATES, AMMONIUM SULFONATES, AND AMINE SULFONATES WHEREIN THE MOLECULAR WEIGHT OF THE HYDROCARBON PORTION OF SAID DISPERSING AGENT VARIES FROM 350 TO 1000 (2) A VOLATILE HYDROCARBON SOLVENT FOR SAID OIL SOLUBLE DISPERSING AGENT (3) A NON-VOLATILE CARRIER SELECTED FROM THE CLASS CONSISTING OF MINERAL LUBRICATING OILS AND SYNTHETIC LUBRICANTS FOR SAID OIL SOLUBLE DISPERSING AGENT (4) AN ALIPHATIC ALCOHOL SOLUTION WHEREIN THE ALCOHOL CONTAINS FROM 1 TO 6 CARBON ATOMS, OF AN OIL INSOLUBLE CALCIUM INORGANIC BASE CONSISTING OF THE REACTION PRODUCT BETWEEN HYDROGEN SULFIDE AND A CALCIUM INORGANIC COMPOUND WHEREIN THE ANION OF SAID COMPOUND IS SELECTED FROM THE GROUP CONSISTING OF OXIDE AND HYDROXIDE RADICALS AND CHARACTERIZED FURTHER IN THAT THE AMOUNT OF SAID INORGANIC BASE VARIES FROM ABOUT 1 1/2 TO 4 1/2 TIMES THAT REQUIRED TO REACT WITH THE SULFONIC ACID WHERE THIS MATERIAL IS USED AS DISPERSING AGENT AND 1/2 TO 31/2 TIMES THE NUMBERE OF CHEMICAL EQUIVALENTS OF THE DISPERSING AGENT WHERE SAID DISPERSING AGENT IS A SALT OF A SULFONIC ACID B. CONDENSING FROM THE RESULTING MIXTURE AT ATMOSPHERIC PRESSURE AN OIL-INSOLUBLE CALCIUM CARBONATE IN PARTICLES, THE DIAMETERS OF WHICH ARE LESS THAN 0.25 MICRON, BY PASSING CARBON DIOXIDE THROUGH SAID MIXTURE TO CONVERT THE EXCESS CALCIUM INORGANIC BASE TO CARBONATE, AND THEN C. REMOVING THE RESIDUAL SOLVENTS BY EVAPORATION.