US 2143066 A
Description (OCR text may contain errors)
Patented Jan. 10, 1939 I UNITED STATES PATENT OFFICE DETERGENT COLIPOSITION No Drawing. Application January 24-, 1936,
Serial No. 60,701
This invention relates to a new and useful soap composition. It particularly involves the use of a specific type of mineral oil in soap compositions to obtain unexpected and highly desirable im- 5 provements.
It has long been known to add various mineral oils to soaps for various purposes. A mineral oil fraction corresponding to petroleum jelly and known in the soap trade as petroleum soap stock has been used as a soap filler. Its greatest utility is to reduce the cost of the soap, although in the opinion of some it improves the feel or consistency of the product. Addition of light mineral oil fractions, such as naphtha, in order to improve the detergent action of soap is also well known. Although the capacity of such soap todissolve oils and greasesmay be increased by reason of the solvent action of the naphtha, the latheringor emulsifying properties of such a soap are materially decreased. Since the ability of soap to emulsify and thus mechanically remove a new soap composition containing a mineral oilhaving a greater solvent capacity and a stronger disinfecting power than corresponding mineral oils previously used.
A still further object of my invention is to provide a soap composition containing mineral oil and having greater emulsifying power than 40 known soaps containing equal quantities of'mineral oils. "1
An additional object of my invention is to provide an oil' for soap detergents which decreases the lathering or. emulsifying power of soaps to a a5 lesser extent than oils hitherto used as an ingredient in water soluble soap compositions.
' I have discovered that a particular type of mineral oil, known in the oil industry as a selective solvent extract, has unusual advantages as 50 an ingredient in soap detergents. In order to better understand the nature of this oil, the method of production will be briefly reviewed.
Petroleum hydrocarbons as found in ordinary distillates, are of many different types. It is known that petroleum distillates. such as lubricating oils, may be separated into two different fractions by extraction with a selective solvent such as liquid sulfur dioxide. The so-called ex-' tract fraction is dissolved by the selective solvent and thereby separated from the remainder of the 5 oil. The remaining fraction of an extracted oil is commonly designated a raffinate. Although similar in external appearance, these two fractions have distinctly different chemical and physical propertiesl 10 Knowledge of the actual chemical constitution of the so-called extract fractions is meagre. They undoubtedly contain a heterogeneous mixture of unsaturated and aromatic compounds of a complex nature. Probably there is also present, saturated non-benzenoid ring compounds having unsaturated side chains as well as such ring compounds (commonly called naphthenes) with no side chains or with only short saturated side chains. Saturated non-benzenoid ring compounds with only very long saturated side chains undoubtedly tend to remain in the rafiinate fraction. This theory as to the chemical constituents of a selective solvent extract is given purely for purposes of explanation andin an attempt to define the extract in terms of what is now known concerning it. However, such theoretical explanations are not to be regarded as an essential feature of my discovery in the sense that my invention would be defeated or avoided if subsequently it is developed that one or more of the constituents have been erroneously represented.
An accurate chemical analysis of a selective solvent extract is not feasible and the petroleum art has developed a test known as the aniline point, to indicate the relative proportions of hydrocarbons present in an oil, which are soluble in selective solvents. Without attempting to describe this well known test, it is pointed out that g the lower the aniline point the greater the pro- 49 portion of such hydrocarbons and the higher the aniline point the smaller the proportion of oils soluble in selective solvents of the liquid sulfur dioxide type. Oils containing small amounts of unsaturated and aromatic constituents, such as Pennsylvania lubricating oils, are generally characterized by an aniline point of from 200 to 260. Oils which contain large proportions of unsat-' urated and aromatic compounds, such as Californiacrude oil distillates which have not been treated with selective solvents, have an. aniline point usually in the range of 150 to 180. 'Selective solvent extract fractions such as contemplated by my invention, have an aniline point in general below 70.
Methods of preparing selective solvent extracts are well known in the petroleum art and are described in many patents and other published literature. These methods comprise in general, agitation of a petroleum distillate with a selective solvent, and separation of the mixture into two phases, an oil phase and a solvent phase. The oil phase, known as a rafflnate is treated to remove any solvent present. The selective solvent phase is treated to recover the oil extracted from the petroleum distillate. It is this extracted oil which I use in soap compositions and which I term selective solvent extract or selective solvent extract fraction.
Many selective solvents are known and are suitable for extracting a petroleum oil fraction which is particularly suitable for addition to soap detergents. The following are a few of the satisfactory solvents: liquid sulfur dioxide, liquid sulfur dioxide with benzol, phenol, phenol diluted with water, Chlorex (a trade name denoting dichloroethyl ether), and nitrobenzene. Unsaturated aromatic petroleum oil fractions corresponding to the above but which resuit from treatment of petroleum distillates with a different type of selective solvent, such as liquid propane, are also contemplated as within the obvious intent of the term selective solvent extract fraction. These fractions are not removed in the dissolved phase by this particular type of solvent. Liquid propane and similar selective solvents, effect a separation of such corresponding oil fractions by precipitating them out of the distillate. The remaining portion of the oil, corresponding tothe raflinate" in the previously described treatments is dissolved with the liquid propane.
Since methods of extraction with selective solvents of the type above listed are well known, it is believed unnecessary to describe in further detail the procedures involved in producing my oil. A competent oil refiner, given the specifications for the oil, such as aniline point, etc., could supply it and would consider the method of production as within the obvious skill of the petroleum art.
An oil which has been found to be particularly suitable for my purposes, is a liquid sulfur dioxide extract obtained from a California mineraloil fraction previously manufactured for insecticidal sprays. The extract from this distillate had the following characteristics (the various oils described will be numbered for convenient reference):
Petrolemn Extract #1 Initial boiling point F 540 (A.'s..'r. M.-D-158).
I have also found lighter fractions such as characterized below operative for my purposes:
Petroleum Petroleum extract No. extract N o. 2 3
Gravity A. P. I 30.8 34.2 Flash (leveland), F 140 130 Viscosity at 100 F. (S. U.)- 29 30 Color (A. S. T. M 2 Lighter than 1 Aniline point 40. 4 36. 2 Initial boiling Igoint. F-- 343 317 (A. 8. T. M.- 158).
v or sweat out of the soap during storage.
The optimum boiling range for extract soap oil stocks is believed to be from about 480' F. to approximately 570 F., although I am not precluded from using heavier or lighter stocks depending upon the particular use for which the soap may be intended. As a specific example of a soap made according to my invention the following proportions of ingredients in a cold made soap are given:
Per cent by weight Tallow 31. 6 Cocoanut oil 31.6 Lump caustic soda 9. 5 Water 22.3 Petroleum extract #1 5.0
The petroleum extract was added to the tallow or cocoanut oil soap stock. Saponification was carried out in the usual manner for cold made soaps. Although I prefer to add the petroleum extract to the tallow or cocoanut oil soap stock, because there is less difliculty in obtaining uniform distribution of the oil through the soap, I am not precluded from adding the extract to the soap during saponification or even to the completely saponified soap by mixing in a crutcher prior to framing.
I have also found the use of my oil to be advantageous in boiled and grained soaps. Here too, I prefer to add the oil to the saponifiable oil stocks but I regard addition at later stages of the process, as for instance during crutching, as within the scope of my invention.
In order to clearly show that my oils have material and unpredictable advantages over ordinary mineral oils previously used by the prior art, the following data are included.
I have compared the lathering or emulsifying power of a soap containing my oil with that of a soap containing a corresponding untreated mineral oil distillate. (By untreated I mean one which has not been extracted with a selective As a lathering test, a .04% calcium chloride solution was added to a soap solution which had been worked into a lather, until the foam broke. The amount of calcium chloride required to break the foam on the different soaps, all other conditions such as concentration of soap, temperature and amount of foam being constant, was taken to be a measure of the lathering or emulsifying power of the soap. The results of such a test are tabulated below:
Lathering test Atmilmnt oiil (cc. of perpe ro cum 0 cent ca cium Petmlwm added (percent chloride soluoi soap) tion to break foam) Percent No 1 extract 5 8. No. l extract l0 7. No. 1 untreated oil (oil from which No. l extract was obtained) 5 7. 5
The above table shows that twice the amount of my oil 10%) may be added without decreasing the lathering or emulsifying power of the soap any more than 5%,,of an exactly corresponding untreated normal mineral oil.
Another distinct advantage for my oil, for which no quantitative tests have been developed, is that the oil is more firmly combined with the soap and consequently has less tendency to bleed Pre- expedients for obtaining aieaoec Selective solvent extracts have greater solvent power for fats, oils and greases and are more toxic to bacteria and the like than ordinary mineral oils. These properties are of value in combination with s'oaps in that the increased solvent power represents an increase in detergent power over that previously obtained with corresponding amounts of mineral oils. Note also, that there has been no corresponding decrease-in emulsifying power of the soap for equal amounts of oils, and that twice as much oil with more than twice the solvent power may be incorporated while retaining the same emulsifying power obtained with previously used mineral oils. The increased toxicityis of value in the disinfecting and insecticide action of the soap. No appreciable increase in irritation to the skin of human beings is noticeable. Direct neutralization of fatty acids with alkali, double decomposition of water insoluble soaps with alkali, as well as the more comrnon methods of making settled down soaps, half-boiled soaps and cold made soaps such as described in the book by Gathmann-American Soaps (published 1899), represent examples of known soaps and methods for making contemplated within the scope of my invention. However, I find my oil to be particularly advantageous when added to grained soaps, as previously herein described.
I am not precluded from adopting the usual blending or mixing of the oil with the soap. For
agents and may be added instance, oil soluble naphthenic soaps, such as sodium naphthenate, are suitable as blending as soaps or formed in situ by addition of free naphthenic acids. Mutual solvents, such as methyl alcohol or protective colloids such as gum arable may'also be utilized,
for stabilizing the dispersions of the oil in soap.
My soap is of utility when combined with rosin soaps and other such well known auxiliary emulsifying agents. My oil may also be incorporated in soaps containing inorganic fillers and other usual compounding ingredients.
Although in my specific examples I have disclosed addition of 5 and 10% Y that I'may vary the proportionsdepending upon the use intended for the soaps. If, for instance, a dry cleaning soap is desired a much larger proportion of oil is suitable. When larger proportions of oil are used the blending agents such as above describedare of particular utility.
In the appended claims the term petroleum fraction soluble in liquid sulfur dioxide" is intended to define petroleum hydrocarbons having by use of sulfur dioxide since extracts with phenol and other selective solvents are soluble in liquid sulfur dioxide. So far as known by me, low aniline point and solubility in liquid sulfur dioxide soaps, boiledpetroleum refining art.
The term soap is intended to include well a more satisfactory.
oil, it is understood prised largely of are two essential characteristics of the extracts which I utilize, whether the extract is obtained by the use of a selective solvent of the type of phenol, liquid sulfur dioxide, etc. or of the propane type. Another property generally characteristic of such oil extracts, is a decidedly greater change in viscosity with change in' temperature than results with either ordinary or selective solvent refined mineral oils.
Although hydrocarbonswith the characteristics above noted are now obtained by selective solvent refining processes, it is conceivable that a mineral oil having characteristics substantially identical with these extracts might be found. Such a similar hydrocarbon oil, though not technically an extractis within the scope of the term petroleum fraction soluble in liquid sulfur dioxide and within the scope or" my invention in its broad aspect.
The term selective solvent extract indicates those unsaturated, aromatic mineral oil fractions obtained by treatment of petroleum dlstillates with selective solvents such as liquid sulfur dioxide, liquid propane and others well known in the known water soluble soaps such as the sodium and potassium salts of common fatty and vegetable oil acids, either alone or in admixture with the usual compounding ingredients.
l. A detergent composition comprising watersoluble soap having dispersed therein a petroleum extract having an aniline point below 70 F. and comprised largely of unsaturated, cyclic nonbenzenoid, and aromatic hydrocarbons, said petroleum extract being characterized in that it is soluble in liquid sulfur dioxide and obtainable by selective solvent emraction of natural petroleums and their distillates.
2. A detergent composition comprising a water soluble soap having dispersed therein a petroleum extract having an aniline point of approximately 3. A detergent composition comprising a watersoluble soap having dispersed therein a petroleum extract having" a boiling point in. the range of from approximately 480 F. to approximately 570 F., and an aniline point below approximately 70 F., said petroleum extract being comunsaturated, cyclic non-benzenoid, and aromatic hydrocarbons, and being characterized in that it is soluble in liquid sulfur dioxide and obtainable by selective solvent extraction of natural petroleums andtheir distillates. n. HAMPTON.