US2043922A - Emulsion oil composition - Google Patents

Description

Patented June '9, 1936 EMULSION OIL COMPOSITION Arthur W. 'Burwell, Niagara Falls, N. Y., and Adolf Kempe, Hackensack, N. J., assignors to Alex Corporation, New York, N. Y., a corporation of New York No Drawing. Application May 14, 1931,

Serial No. 537,480

8 Claims.

This invention relates to the preparation of mineral oil compositions which either are emulsions or are readily emulsifiable. More particularly, the invention is concerned with the use of certain acidic oxidation products of mineral hydrocarbons as the emulsifying agents or emulsifiers for mineral oils in the preparation of cutting and/or grinding oil emulsions or solutions.

Heretofore ithas been common practice to use, in the cutting of metals by means of high-speed cutting tools, compositions, denominated cutting oil emulsions or soluble oils, which have contained, besides mineral oil lubricating distillates, material quantities of unsaturated fatty acids such as oleic acid, or unsaturated oils such as lard oil, cottonseed oil, tallow oil, or other oils containing olein or any unsaturated acids either as such or combined either with alkali metals or with glycerin. Investigators also have recommended the use, with mineral lubricating oil, of hydrocarbon sulfonates, lard oil sulfonates, or the corrosive phenols or their sulfonates. While the compositions containing these unsaturated fatty acids usually are readily emulsifiable in water, they usually possess two serious disadvantages,viz., they either actively promote rusting or corrosion of the ferrous metals with which they come into contact or at least do not tend to prevent corrosion of the said metals; and, they either cause or are conducive to the growth of skin eruptions and afiections (such as boils) on the persons of workmen who of necessity frequently come into contact with said compositions.v

An object of the present invention is to provide cutting oil compositions of the so-called soluble oil type' which are adapted actively to. check corrosion of ferrous metals. Another object of invention is the provision of cutting oil compositions which tend to prevent, or at least do not promote, the occurrence of skin eruptions on the persons of workmen coming into contact therewith. Other objects of invention include the provision of such compositions having markedly enhanced creeping qualities. i

It has now been found that the above, and other, objects of invention arewattained by either wholly eliminating or else reducing to a relatively very small amount the content of oleic acid or equivalent unsaturated fatty acid compounds of the aforesaid prior art'compositions, substituting in its stead certain saturated fatty acids-obtained by practicing certain separation and purification procedures upon the reaction mixture obtained by the controlled partial oxidation of mineral oil hydrocarbon mixtures, Y

The starting material upon-'jwhich the process of the present invention is practiced is the reaction mixture obtained by contacting an oxidizing gas such, for instance, as air or oxygen-enriched air, at a temperature above about 100 C. and at a pressure greater than atmospheric pressure but not substantially above about 320 pounds per square inch, generally in the presence of an exciter of oxidation which may be a recognized oxidation catalyst or may be a mixture of non-acidic partial oxidation products from a previous charge, with a petroleum hydrocarbon mixture in liquid phase. The petroleum hydrocarbon mixture thus subjected to oxidation treatment may be any petroleum distillate, including especially the. 36-40 fuel oil distillate, or petrolatum, or any of the normally solid constitu- Sharples wax, and the like. By Sharples wax is meant that semi-solid product, known variously as dark green petrolatum or amorphous wax, which is obtained from crude petroleum oil by diluting the topped crude with a relatively large amount of gasoline, chilling the mixture to say 30 to 40 below zero F., and centrifuging or otherwise separating liquids from the so-chilled mass.

For preparing the crude reaction product used as the starting material of the present invention, oxidation is continued untilthat point is reached at which a test sample loses, upon saponiflcation of the saponifiable constituents, with an appropriate alkali, suitable dilution with water, and separation of the aqueous layer from the nonaqueous layer, about to 45% of itself in the.

incipient formation of hydroxy carboxylic acids which are insoluble in petroleum hydrocarbons may, and for obvious economic reasons should, be avoided.

The first step of the process of the present in vention consists in separating from said reaction mixture those constituents which are most valuable as emulsiflers of mineral oils. In the case of a reaction mixture from paraiiin waxor other crystalline waxes, a fairly satisfactory method (Method I) consists in sweating the normally liquid acidic oxidation products out of the cold reaction mixtin'e, the more'solid residue being returned for further oxidation, or in pressing these liquid products out of the cold mixture, the press cake being returned. The crystalline waxes ents of crude petroleum including paraflin wax, l

from petroleum consists of hydrocarbons of such a nature that they produce petroleum-insoluble acids only with diificulty: therefore, if desired, such waxes may be subjected to a sufiiciently prolonged oxidation to convert almost the whole of the mass to saponifiable oxygencompounds without forming an undue amount of petroleum-insoluble bodies, in which case a separation such as that aforesaid need not necessarily be resorted to.

A second method of separation, of general application, is that suggested in the test above noted; i. e., saponification ofthe saponifiable constituents of the reaction mixture by means of alkali or an alkaline earth metal compound. According thereto, the starting material is treated with an appropriate amount of an alkaline-acting saponifying agent, such as caustic soda or soda ash or lime, in association with some water whereby to form soaps of the saponifiable constituents. The saponified constituents of the resulting mixture may be removed therefrom in one of two ways: according to one method (Method II), the mixture is diluted with a considerable quantity of water, with agitation, and is then settled, whereupon it separates into a supernatant oily or non-aqueous layer and a subnatant aqueous layer containing the soaps. This subnatant layer is withdrawn and is treated with a suitable amount of an acid such as a mineral acid, e. g., sulfuric acid, whereupon there precipitate out the bodies extracted from the starting material.

According to the alternative method (Method III) the resulting mixture is directly agitated with an appropriate amount of alcohol (either ordinary 95% alcohol or even an alcohol-water solution containing 80% alcohol), whereby to extract from the aqueous layer its content of acidic compounds. In this-latter procedure the alcoholic solvent thereafter is separated from the extracted material by an ordinary distillation procedure;

Still another method of separation consists in thoroughly agitating the starting material (1. e., the oxidation reaction mixture described herein before) with a suitable amount of alcohol (e. g., ordinary 95% alcohol), whereby to dissolve in the alcohol its content of acidic compounds, drawing off the alcoholic solution, and separating the alcohol from the extracted material by an ordinary distillation procedure (Method IV). By this method there are extracted the acids content of the starting material without extraction of an undue amount of the non-acidic oxidation products.

Of these alternative separation methods we find that the most complete separation of the acids content of the starting material from certain nonacidic oxidation products which tend to persist in association with those acids is effected by Method III above, since thereby it is possible to free the saponified acids from substantially all of the unsaponifiable but emulsifiable bodies which so tenaciously associate themselves with the acids both in the free and in the combined forms. This is particularly true with respect to clean separations of acidic compounds from petrolatum or the so-called Sharples wax. In operating under this method, other solvents than alcohol maybe used e. g., a ketone such as acetone. In'somecasesit has been found desirable to chill the"mixture' containing the solvent (e. g., alcohol) before separation of .the extract, whereby ,tofdrop out of the 'extract bodies other than acidic/compounds, which non-acidic bodies have been found to be of inferior value or no value in emulsifying lubricating oil.

The foregoing separation procedures not only serve to yield a final product having a reduced content of unsaponifiable constituents (i. e., oxidized compounds having other than an acidic constitution) but also to efiect a partial removal from the final product of the small content of malodorous by-products encountered in the crude oxidation mass. Where it is desired to reduce still further the content of malodorous icy-products from a product obtained from petroleum wax it may be desirable to subject the product to.-.a distillation treatment. This distillation may or may not be carried out under conditions of reduced pressure (i. e., vacuum distillation) and/or in the presence or absence of direct steam. By such treatment the malodorous by-products mainly are collected in the distillate. Malodorous by-products occurring in the acidic product from oxidized petroleum distillates may largely be removed by washing the products one or more times with small amounts of 95% alcohol.

The compounding of the above-described emulsifying mixtures with mineral oils, lubricating oils, and similar oils, consists in dissolving the emulsifier, in the il,'preferably at about 60-80 C., separating (if necessary) any oil-insoluble sediment, and (in case the'emulsifier is not already neutralized with alkali) neutralizing with concentrated alkali or with triethanolamine or similar acting bodies or mixtures thereof. As the emulsifier there may be used the separated acids from a starting material produced from a petroleum wax, or those produced from a normally liquid petroleum distillate. Since their properties, including relative fluidity, etc., difier somewhat, it sometimes is advantageous to'use as the emulsifier a mixture of acids derived from both waxes and distillates. To obtain a clear emulsion oil which is fluid and will not separate on long standing'in the cold, it requently is necessary to add to the above composition a relatively small amount of water, usually not over 0.5% by weight. But the amount of water so added is to be carefully standardized according to the concentration and type of alkali used in neutralization.

In describingbelow some of the characteristic emulsion oil compositions falling within the scope of the present invention the nature of the mineral acids emulsifier will be indicated by reference to the original source of the said acids: thus, by "wax acid is meant the mixture of acids separated out of a reaction mixture produced by the controlled partial oxidation of a petroleum wax by practicing one or the other of the abovedescribed separation procedures, and by 36-4(l acid is meant the mixture of acids similarly derived from a 36-40" Baum fuel oil distillate.

upon being mixed with waterit almost instantly yields a stable white emulsion which shows no separation of oils after standing for many weeks and remains in the liquid or sol state. For preparing aso-called cutting oil emulsion from the water, the resulting stable emulsion is an ex-- the so-called straight cutting oils.

above composition 1 gallon of the'composition is thoroughly admixed with 20 gallons of water. When the composition is diluted 1 to 50 with cellent grinding oil. The emulsions prepared from this composition have been found to make for cooler and better cutting, to show a strong tendency to prevent rusting of ferrous articles on which it stands, and to not cause boils or other skin affections on the hands and arms of the workmen using the emulsions.

Example I! Grams Wax acid'. 10 28 parafline nil Example III Grams 36-40 acid 4 30 pa'rafflne oil 96 The solution resulting from the thorough admixture of the above ingredients is representative of The addition of the 36-40 acid to the parafilne oil has been found to enhance the creeping quality of the oil to such an extent that the point of a threadcutting tool is kept cool and no welding occurs, so that the tool remains sharp, better cutting is accomplished, less tearing of the threads results, and less changing of tools is made necessary than in the case of using parafline oil alone. Illustrating the improvement worked by the use of the 36-40 acid with the oil, it may be noted that as high as 36,000 bolts have been cut with a single set of chasers cooled with this composition, whereas the highest record of that shop theretofore had been from 6,000 to 7,000 bolts on the same machine.

We have found that for the 36-40 acid mentioned in the above example there may be substituted a like quantity of wax acid or a mixture of the acids derived from a petroleum wax and from a petroleum distillate: also, that the amount of acid (either wax acid or 36-40 acid or mixture of the two) may be varied, e. g., to constitute from 2% to 10% of the solution. Furthermore we have found that the oil" ingredient may be any fairly fluid lubricating oil, such as 28, or

25 parafline oil.

By distilled paramne acids herein referred to is meant a mixture of acids obtained by subjecting a product consistingmainly, of paraffin acids and produced by the separation methods set out treatment being the final product. The distilled paraffine acids product thus obtained contains practically no (say, not more than 5 or 6% and usually less) unsaponifiable material, has a very low iodine number, and is much more nearly colorless than the nondistilled product.

According to this example, the acids are dissolved in the oil with agitation, whereupon the concentrated aqueous solution of alkali (e. g.,

caustic soda) is added with stirring. The resulting composition readily emulsifies in water to produce a cutting oil emulsion having desirable properties.

The above described illustrative composition formulae do not involve the use of oieic acid or of any other unsaturated fatty acid or derivative thereof or of any other emulsifier, of any nature whatsoever, in addition to the aforesaid petroleum acids. In use, they do not corrode the metals into contact with which they come, but rather positively protect the metals against corrosion. Also, they have been found, upon extensive trial, not to promote or cause skin eruptions. In some cases it may be desirable to use in the composition some oieic acid or its equivalent. We have found that the characteristics of our separated petroleum acids are such that there is required, for any specific effect, a less amount of oleic acid addition than is required in the known soluble oil compositions.

This composition, which emulsifies practically instantaneously in water to form a stable emulsion, may contain the wax acid in proportion ranging between 6% and 12% of the total composition, and the oleic acid content may be replaced in part or in toto by a corresponding increase in content of wax acid.

By the expression "an exciter of oxidation as used hereinbefore and in the appended claims we mean to include either a recognized oxidation catalyst or a mixture of non-acidic partial oxidation products from a. previous charge. In either event the same effect is had, viz: that the inception of active oxidation is accelerated.

We claim:

1. Process which comprises treating with an aqueous solution of a. caustic alkali a crude reaction mixture of saponifiable and unsaponifiable aliphatic compounds produced by controlled partial oxidation .of a mixture of petroleum hydrocarbonsin liquid phase and in the presence of an exciter of oxidation at elevated temperature and'pressure, said reaction mixture comprising unoxidized hydrocarbons, unsaponiflable oxygen compounds of hydrocarbons, malodorous byproducts and saturated aliphatic carboxylic acids,

separating the resulting aqueous soap solution from unsaponified material, treating the separated soap solution with alcohol, separating the resulting alcoholic solution from material in-;

soluble therein, and removing alcohol from the product so separated. I

2. Process which comprises treating with an aqueous solution of a caustic alkali a crudereaction mixture ofsaponifiable and unsaponifiable I aliphatic compounds produced bycontrolled .par-

tial oxidation of a mixture of petroleum hydrocarbons ,in liquid phase and in the presence of an exciter of oxidation at elevated temperature.

and pressure, said reaction mixture comprising ,unoxidized hydrocarbons, unsaponifiable oxygen compounds of hydrocarbons, -malodorous by.- products and saturated aliphatic carboxylic acids,

. separating the resulting aqueous soap solution from unsaponified mater-iai,1treating the separatedsoapsolution with alcohol, separating the resulting alcoholic solution from material insoluble therein, removing alcohol fromthe product so separated and subjecting the resulting product to vacuum distillation treatment at an elevated,

temperature below: the-boiling points of, said acids. I I I I 3. Process which comprises treating with an and pressure, said reaction mixture comprising unoxidized hydrocarbons, unsaponifiableoxygen compounds of hydrocarbons, malodorous byproducts and saturated aliphatic carboxylic I acids, separating the resulting aqueous soap solu-- tion from unsaponified material, treating the separated soap solution with an, amount of an acid suflicientto decompose the soap, separating the resulting water-insolublematerial from the aqueous solution, treating. the separated waterinsoluble material with alcohol, separating the resulting alcoholic solution from material insoluble therein, and removing alcohol from the product so separated.

4. Process which comprises treating with an aqueous solution of a caustic alkali a crude reaction mixture of saponifiable and unsaponifiable aliphatic compounds produced by controlled partial oxidation of a mixture of petroleum hydrocarbons in liquid phase and in the presence of an exciter of oxidation at elevated temperature and pressure, said reaction mixture comprislng unoxidized hydrocarbons, unsaponifiable oxygen compounds of hydrocarbons, malodorous by-products and saturated aliphatic carboxylic acids, separating the resulting aqueous soap solution from unsaponified material, treating the separated soap solution with an amount 01' an acid sufl'icient to decompose the soap, separating the resulting water-insoluble material from the aqueous solution, treating the separated waterinsoluble material with alcohol, separating the resulting alcoholic solution from material insoluble therein, removing alcohol fromthe product so separated, and subjecting the resulting product to vacuum distillation treatment at an elevated temperature below the boiling points of said acids.

5. An acidic mixture consisting essentially of water-insoluble but petroleum-soluble saturated aliphatic carboxylic acid compounds of petroleum origin, said mixturebeingsubstantially free of ketones, other unsaponiflable bodies and malodorous constituents, and substantially identical with the product produced by treating with an aqueous solution of a caustic alkali a crude reaction mixture of saponifiable and unsaponifiable aliphatic compounds produced by controlled partial oxidation of a mixture of petroleum hydrocarbons in liquid phase and in the presence of an exciter of oxidation at-elevated temperature and pressure,'said reaction mixture comprising 'un-- oxidized hydrocarbons, unsaponiflable oxygen' compounds of hydrocarbons, malodorous byproducts and saturated aliphatic carboxylic acids,

separating the resulting aqueous 'soapsolution' from unsaponifled 'materi'aL-treating the separated soap solution with alcohol, separating the resulting alcoholic solution from material in product so separated.

6. An acidic mixture consisting essentially of watenin'soluble but petroleum-soluble saturated aliphatic carboxylic acid compounds of petroleum I odorous constituents, and substantially identical with the product produced by'treating with an aqueous solution ofa caustic alkali a crude reaction mixture of saponifiable andunsaponifiable aliphatic compounds p'roduccdby controlled partial oxidation of a mixture of petroleum hydrocarbons in liquid phase and in the presence of an exclter of oxidation at elevated'temperature and pressure, said reaction mixture comprising unoxidized hydrocarbons, unsaponlfiable oxygen compounds of hydrocarbons, malodorous byproducts and saturated aliphatic carboxylic acids,

separating the resulting aqueoussoap solution from unsaponified material, treating the separated soap solution with alcohol, separatlng the resulting alcoholic solution from material insoluble therein, removing alcohol 'from the product so separated and subjecting the resulting product to vacuum distillation treatment at an elevated temperature below the boiling points of said acids.

'7. Product defined in claim 5, characterized in that it contains also normally liquid petroleum distillate.

8. Product defined in claim 5, characterized in that it contains also normally liquid petroleum distillate in an amount between 65 and 2400 parts by weight of distillate for each 100 parts by weight of the acidic compounds.

ARTHUR W. BURWELL. ADOLF KEMPE.

solubletherein, and removing alcohol from the f