US 2901433 A
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Aug. 25, 1959 5. SPRING CLEANING COMPOSITION Filed July 17, 1953 O 0 O o 6 IOO United States Patent CLEANING COMPOSITION Samuel Spring, Philadelphia, Pa., assignor to Pennsalt Chemicals Corporation, a corporation of Pennsylvania Application July 17, 1953, Serial No. 368,771
12 Claims. (Cl. 252-118) This invention pertains to a cleaning composition of matter and particularly to a composition of matter for removing greasy soils and soils having mixed oily and inert particulate or fibrous ingredients.
In many industries, it is necessary to clean surfaces of accumulated soil which is partly grease, and partly dry dirt. One example is the railroad industry where locomotives and cars must be cleaned of a soil including fuel and lubricating oils, coal dust, and ordinary dirt.
Other common soils especially resistant to many conventional cleaners, are buffing compounds and heattreating oils which have been partially carbonized.
In various industries, workers hands are often soiled by mixtures of grease and inorganic dirt which cannot be removed with conventional soaps and hand cleaners. Obviously, in such cases, the type of cleaner which can be employed is limited by the sensitivity of the human skin to strong reagents.
Neither organic solvents alone, nor conventional soaps or alkaline washes alone have proved suitable for such cleaning, and many proposals have been made for cleaning solutions which would combine the characteristics of organic solvents and conventional soaps.
In any cleaner of the type adapted to remove grease and oil, together with other soils, an important aspect of the cleaner is the amount of grease or oil that it can solubilize, i.e. hold in the body of the cleaner in a homogeneous form. It is characteristic of the cleaners herein described that after solubilization, soil and cleaner are readily removed by a water rinse.
It is an object of the present invention to provide a cleaning composition compounded of materials moderate in cost, which will readily remove greasy soils and soils containing both grease and inert particulate matter.
It is also an object of the present invention to provide a cleaning composition capable of solubilizing large quantities of oil and grease.
Another object of the present invention is to provide a cleaning composition which can be used on the human skin without undue irritation.
According to the invention, the above and other objects are obtained by formulations which basically comprise a soap, water, a weak organic acid, and a neutral salt. If it is desired that the composition be clear an alcohol is also added, and the prepared compositions, according to the present invention, contain an alcohol.
An outstanding feature of my invention is the discovery that in such systems, a synergistic relationship exists between the organic acid and the neutral salt, which makes it possible for formulations according to the invention to dissolve large quantities of oil or grease. By means of this relationship, relatively small quantities of the novel formulations may be applied to soiled surfaces, where they function to dissolve grease or oil, permitting the latter, together with particulate dirt, to be rinsed off with a water spray or stream.
The soap is present in a proportion between about 1% use compositions are within the scope of the present,
of the composition and may be present in an amount up' to and including the saturation point of the composition for the salt. salt required to reach saturation will depend on the particular salt employed and the other components of the composition. Preferably the salt comprises between about 0.1% and about 1.0% inclusive of the weight of the composition.
The composition includes from about 5% to about water, and preferably from about 10% to about 60% water.
It is also desirable, although not essential to the invention, in its broadest aspect, that the weight ratio, weak organic acid to soap, be between about 0.3 and about 2, inclusive, and preferably between about 0.5 and about 1.2, inclusive.
As previously stated it is generally desirable to also include an alcohol in the composition. When present, the alcohol will comprise between about 0.5% and about 20%, inclusive, of the weight of the composition, preferably between about 2% and about 15% inclusive.
As pointed out above, the outstanding feature of the present invention is the discovery that a synergistic relationship exists between the fatty acid and the neutral salt, in a system comprising these substances together with soap and water. This synergism permits the compositions of the present invention to solubilize substantially larger quantities of grease or oil than could be solubilized by a system wherein either the fatty acid or neutral salt is present without the other. The invention in its broadest aspect, therefore, includes a composition having the above mentioned ingredients. It has been found, however, that for many applications it is desirable to include in the formulation quantities of an organic solvent.
The invention, therefore, further includes compositions comprising a soap, a weak organic acid, a neutral salt, water and an organic solvent with or without an alcohol. In general, where the solvent is included it comprises from about 6% to about inclusive, of the composition, and preferably from about 10% to about 80%, inclusive.
The invention besides including compositions that contain no organic solvent and are used as such, also includes concentrates containing some organic solvent designed for dilution prior to use. Thus in many instances, it is desirable to make up a concentrate having a relatively small quantity of solvent which may be diluted to use concentrations in the field. Such concentrates generally comprise between about 6% and about 50% solvent, in-
clusive, the compositions preferably containing betweenabout 8% and about 30%, inclusive. These percentages are based on the weight of the composition. When the concentrates are diluted in the field, the resulting compositions generally contain by Weight from about 40% to about 90% solvent, inclusive, and preferably from about 60% to about 80%, inclusive, Both concentrates and invention.
The drawing shows the eifect of the inorganic salt in a composition according to the invention. This is hereinafter more fully discussed.
A further discussion of the several ingredients follows:
It will be understood that the amount of THE SOAP The term soap as used inthe present invention includes both conventional soaps and the anionic detergents.
The function of soap in the present compositions is to exerta detergent action on the soil to be attacked, to aid in dissolving the organic solvent in the water of the composition, and to serve-as the base for solubilization of oilsand greases.
The soap employed in the present compositions may be a conventional soap, that is, an alkali metal, ammonium, amine or alkanol amine salt of a fatty or rosin acid, such, for example, as the alkali metal, ammonium, morpholine, isopropylamine, or ethanol amine salts of caproic, lauric, palmitic, stearic, oleic, linoleic,.ricinoleic, or'abietic acid.
If the soap is the salt of a' fatty acid, the acid should preferably have more than 5 and less than 26 carbon atoms in the molecule.
Among the "conventional soaps, the soaps of oleic acid are generally preferred, such as potassium and sdium'oleate. However, these compounds are relatively expensive, and use may be had of more economical soaps such as those made from tall oil.
' Tall oil is a by-product of the paper industry, and contains principally rosin acids, oleic acid, and linoleic acid. It is readily saponified with caustic to give what will be referred to as tall oil soap. One suitable tall oil soap contains:
The conventional soap may be added as such, or theacid may be added to the other ingredients and then neutralized in situ with the desired base.
The invention also uses synthetics of the anionic type generally referred to as anionic detergents. Examples of these are the sulfates and sulfonates derived from long chain alcohols such as sodium octyl sulfate, sodium decyl sulfate and sodium dodecyl sulfonate and alkyl aryl sulfonates having the general formula R -AF- SOgM where M is alkali metal or ammonium, Ar is plienyl or naphthyl and R is an alkyl group, such for example, as sodium dodecyl benzene sulfonate.
Combinations of different soaps may often be employed advantageously. Thus, mixtures of conventional soaps and anionics may be used.
Though nonionic detergents are not included among the soaps found suitable for the compositions of the present invention, inclusion of these together with the soap used has been found to give excellent results. This is particularly true where the cleaning composition is to be used for application to a badly soiled area in small quantities followed by flushing with water, since the non-ionic promotes the rapid emulsification of the soilladen cleaner. When a non-ionic detergent is used it is generally included inthe cleaning composition in amounts of about 0.5% to by weight inclusive.
THE WEAK ORGANIC ACID The weak organic acid employed should have an ionization constant not greater than that of benzoic acid (6.3 l0- The acid may be a fatty acid, either saturated or unsaturated; an aliphatic acid other than a fatty acid, as for example, the acids derived from the oxidation of petroleum; an aromatic acid, as for example, benzoic acid or cinnamic acid; a cyclic acid, such as abietic acid; or a heterocyclic acid, such as picolinic acid.
Rosin acids such as abietic acid and fatty acids having from 6 to 26 carbon atoms such as caproic, lauric, palmitic, stearic, oleic, linoleic, and ricinoleic, are generally preferred. Of this group, oleic acid and tall oil, a mixture of rosin and fatty acids, are the acids of choice, the latter particularly because of its low cost. Crude or refined "tall oil maybe used.
One function of the fatty acid is to promote the bilizing power of the soap.
More important, however, the fatty acid cooperates with the inorganic salt, vastly to increase the solubilizing power of the composition, as will be brought out more fully below.
THE NEUTRAL SALT The neutral salt in the present formulations functions in cooperation with the weak organic acid greatly to increase the solubilizingpower of the formulation. Where the composition includes an organic solvent, the salt also acts with the fatty acid to increase the capacity of the aqueous base system of the present invention for the solvent.
Any neutral salt may be employed, providing that it is sufficiently soluble in the composition to reach the minimum prescribed salt content of 0.05% by weight. A few examples of such neutral salts are sodium sulfate, potassium sulfate, sodium chloride, potassium chloride, and sodium chromate. Ferric chloride and ferrous sulfate were found satisfactory after their solutions were neutralized.
The effect of increasing the salt content on the mineral oil solubility of a formulation prepared according to the invention, is shown by the following experiment, in which sodium sulfate was used as the neutral salt.
A number of portions of a basic mixture were prepared, each portion consisting of:
solu- To each of several samples of the basic mixture were added different quantities of sodium sulfate. Kerosene was then added to each sample in the amount required to clear the solution and this amount recorded. The curve of the drawing designated Kerosene to Clear shows the relationship between the amount of kerosene added and the grams sodium sulfate present in each sample of the basic mixture.
Mineral oil (SAE 30) was then added carefully, with stirring, to cc. samples of each of the mixtures containing the basic mixture, sodium sulfate and kerosene and a record made of the maximum amount of oil that each sample would dissolve. The curve in the drawing, Mineral Oil Solubilized shows the relationship between the amount of SAE 30 mineral oil solubilized and the sodium sulfate and kerosene content of the system. It
will be noted from this graph that the solubilizing power by adding the salt, compared to the formulation with no' salt.
Thus, with no salt added, 12 cc. of medium viscosity mineral oil were solubilized per 100 cc. of cleaner. With the addition of only 0.4 gram of salt the amount of mineral oil solubilized increased to approximately 40 cc. This is a surprising increase of over 300%.
It is quite surprising and entirely unexpected that the solvency of a predominantly organic liquid, quantitatively speaking, containing only about 12% water, for other organic substances should be so tremendously improved by a small amount of an inorganic salt.
Moreover, as noted above, the salt and the free fatty acid present in the novel formulations, have a synergistic action. This is illustrated in Table I (below).
Column A of Table I shows a formulation containing a neutral inorganic salt (1 gram Na SO and substantially no free organic acid, since all the tall oil has been neutralized by the NaOH. With this formulation a homogeneous system could not be obtained with the addition of solvent, and only 2.5 cc. of mineral oil were solubilized per 100 cc. of composition.
Column B shows a composition including an excess of organic acid, but no salt. With this formulation a stable solution was obtained with 230 grams of solvent, but again only a very small amount (3.0 cc.) of mineral oil was solubilized.
In column C, a composition is shown containing both free organic acid and neutral salt according to the invention. This composition solubilized 23 cc. of mineral oil. It is thus clear that only when both weak organic acid and neutral salt are present, are the benefits of the It is believed that the alcohol in the present composition generally acts to improve the solubilizing power of the soap.
The alcohols employed in the present formulations should be liquid at normal temperatures and soluble in the system. Alcohols at least sparingly soluble in water are preferred, and alcohols of between about 3 and about carbon atoms are considered satisfactory. Some examples of suitable alcohols are isopropanol, butanol, pentanol, cyclohexanol, the monoethyl and monobutyl ethers of ethylene glycol, methyl pentane diol, and alpha terpineol. Combinations of alcohols may be used advantageously, as for example, a combination of cyclohexanol and butanol, or of alpha terpineol and isopropanol.
THE ORGANIC SOLVENT The organic solvent used may be any organic liquid which will dissolve the grease which it is desired to attack. Usually, the organic solvent will be a hydrocarbon derived from petroleum or from coal tar. It may have either an aliphatic or an aromatic base, and usually has a boiling-point range between about 75 C. and about 400 C., preferably between about 110 C. and about 330 C.
Some examples of suitable hydrocarbon solvents are kerosene, gasoline, benzine, benzene, toluene, xylenes, and Stoddard solvent. For purposes of safety, it is desired in some applications, to use solvents having a high flash point, i.e., having a flash point over 100 R, such as Stoddard solvent.
Some other conventional solvents that may be used are carbon tetrachloride, perchloroethylene, trichloroethylene.
Where an alcohol is included, solutions made according to the invention are clear and bright. So far as physical appearance and stability are concerned, they have all the characteristics of true solutions.
In those formulations which include fatty acid salts as the soaps, the preferred method of manufacture is to start with a liquid composed of water, alcohol, and excess organic acid. An appropriate caustic e.g., NaOH, is then added slowly.
The dispersion will first become a cloudy viscous liquid, then a clear gel, and finally a clear fluid liquid which foams slightly. l p
In all formulation, the addition of solvent is preferably handled in the same manner and similar changes are noted. That is to say, the solvent, e.g., kerosene is added gradually to a mixture of soap, water, alcohol, and
6. acid. As the kerosene is added, a cloudy dispersion, then a cleargel, then a somewhat viscous clear liquid, then a cloudy dispersion, and finally a fluid clear liquid may be observed. For some uses it is sometimes preferred to discontinue addition of the kerosene or other solvent prior to obtaining the first fluid clear liquid.
The followingexamples are given to illustrate the invention. It will be understood, however, that these examples are merely illustrative and are not to be taken in any way as limiting the invention as defined in the appended claims.
Example] Percent by weight Refined tall oil 54.3 Hexylene glycol 11.8 Sodium hydroxide 2.7 Sodium sulfate 0.9 Water 30.3
Example II Percent by weight Sodium oleate 5.1 Oleic acid 3.0 Butanol 3.0 Cyclohexanol 5.4 Kerosene 44.1 Sodium tripolyphosphate 0.6 Water 38.8
Example III Percent by weight Soap of tall oil (sodium tallate) 14.0 Tall oil 14.2 Cyclohexanol 10.8 Kerosene 33.8 Sodium sulfate 0.1 Water 27.2
Example IV Percent by weight Tall oil soap (prepared by reacting 650 parts by weight crude tall oil, 79 parts NaOH, and 1280 parts H O) 18.0 Cyclohexanol 2.5 Kerosene 72.6 Tall oil (refined) 5.4 Na SO (added as 80 cc. of a solution containing 2 grams per cc.) 1.5
Example V Percent by weight Cyclohexanol 3.2 Water 19.9 Kerosene 44.8 NaOH 0.5 An alkyl aryl sulfonate (containing about 8% water) 20.8 Na2SO4 1.2 Tall oil (crude) 9.6
Example V1 Percent by weight Refined tall oil 19.9 Hexylene glycol 17.7 NaOH 2.7 Benzoic acid 17.7 Na SO 0.9 Hifiash petroleum hydrocarbon solvent (boiling range 520-625 F.) 11.0 Water 30.1
Example V11 Percent by weight Hifiash petroleum hydrocarbon solvent (boiling 7 Example VIII Percent by weight Kerosene.
B-rij; 30' (a.- nonionic emulsifier consisting essentially of the polyoxyethylene ether of lauryl alcohol) 2.3
Example IX Percent by weight Kerosene 70.67 Water 10.19. Tall oil (refined) 13.67 Hexylene glycol 3.22 N'aOH '(97'percent) 0.64 Na- SO; 0.24 Pine oil 1.37
Example X v Percent by weight. Refinedtall Oil .L 43.4 Hexylene glycol A 14.7 N'aOH' 2.1 Na SO .8 N'onic' 218 (tertiary dod'ecyl 'mercapto polyethylene glycol) 7.1 Water 22.0 Petroleum solvent 9.9
(This may be used as such but is designed primarily as a. concentrate. It is preferably diluted prior to use with.
3. volumes of a petroleum solvent or /5 volume of water and 3 volumes of a petroleum solvent.)
Compositions according to the invention will readily remove mineral and cottonseed oils from metal panels. They have also removed a particularly tenacious cup grease and have been found to be substantially superior to present commercially available cleaners for removing buffing' compounds from zinc base die castings. In another application, one of these cleaners removed partially carbonized heat-treating oils much more efliectively than available commercial materials.
Having thus described my invention, I claim:
l. A cleaning composition comprising by weight, from about 1% toabout 50% of asoap selected from the group consisting of the alkali metal, ammonium, amine and alkanol amine salts of the fatty and rosin acids, from about 5% to about 80% water; from about 1% to about 50% of an organic acid selected from the group consistingof rosin acids, and fatty acids having from about 6 to about 26 carbon atoms; from about 6% to about 90% of an organic solvent. selected from the group consisting of hydrocarbon solvents having a boiling point range between about 75 C. and about 400 C., carbon tetrachloride, perchloroethylene and trichloroethylene; and at least about 0.05% of a neutral alkali metal salt of a mineral acid selected from the group consisting of sulphuric acid, hydrochloric acid and chromic acid.
2. The composition of claim 1, wherein the soap is tall oil-soap.
3. The composition of claim 1-, wherein theorganic acid is tall oil. 1
4. The composition of claim 1, in which the organic solvent is a high flash point hydrocarbon.
5-. The composition of claim 1, in which the organic solvent is kerosene.
6. The composition of claim 1, wherein the weight ratio.
8. A cleaning composition comprising by weight, from about 1% to about 50% of a soap selected from the group consisting of the alkali metal, ammonium, amine, and alkanol amine salts of fatty androsin acids, from about. 5% to about 80% water; from about 0.5% to about 20%of' an alcohol having between about 3 and about 10' carbon atoms in the molecule; from about 1% to about 50% of an organic acid selected from the group: consisting of rosin acids, and fatty acids having from about 6fto about 26 carbon atoms; from about 6% to about 90% of an organic solvent selected from a group consisting of hydrocarbon solvents having. a boiling point range between about. C. and about 400 C., carbon tetrachloride, perchloroethylene and trichloroethylene; and at least 0.05% and not substantially more than thequantityrequired to saturate said composition of a neutral alkali metal salt of a mineral acid selected from the group consisting of the alkali metal salts of hydrochloric, sulphuric and chromic acids.
9. The composition of claim 8, in which the alcohol is cyclohexanol. I
10. Thecomposition of claim 8,. in which the alcohol is methyl pentane diol.
11. A cleaning composition comprising from about 7.6 to about 10.2% water, from about 3.2- to about 4.6% hexylene glycol, from about 68 to about 75% kerosene, from about 0.21 to about 0.25% sodium sulfate, and the reaction. products 0t fromabout 12.5 to about 13.6% tall oil, and. from about 0.64 toabout 0.73% sodium hydroxide, said percentages being taken on the Weight of the composition.
12. A cleaning composition comprisingby weight, from about 3% to. about 25% of a soap selected from. the; group consisting of the alkali, metal, ammonium, amine, and alkanol amine salts of fatty and rosin acids, from about 2% to about 15% of an alcohol having from about 3- to about 10 carbon atoms in the molecule, from about 10% to about 65% water, from about 10% to, about of an organic solvent selected from the group consisting of hydrocarbon solvents having a boiling point range between about 75 C. and about 400 C., carbon tetrachloride, perchloroethylene and trichloroethylene, from about 2% to about 25% of an organic acid selected from the group consisting of rosin acids and fatty acids having between about 6 and about 26 carbon atoms and from about 0.1% to about 1% of a neutral alkali metal salt of a mineral. acid selected from the group consisting of hydrochloric, sulphuric and chromic acids.
References Cited in the file of this patent UNITED STATES PATENTS 1,377,843 Liddle May 10, 1921 1,429,978 Smyth Sept. 26, 1922' 2,091,121 Lenher Aug. 24, 1937 2,107,287 Curran Feb. 8, 1938 2,403,619 Skinner July 9, 1946 2,674,580 Henkin Apr. 6, 1954 2,700,654 Holman Jan. 25, 1955 2,740,760 Pilch Apr. 3, 1956 2,787,596 Stewart Apr. 2, 1957 FOREIGN PATENTS 363,794 Great Britain Dec. 31, 1931 OTHER REFERENCES Chemical Formulary, Bennett, volume VIII, pp. 345- 347, 351, Chemical Pub. Co., Inc., Brooklyn, N.Y. (1948).
Surface Active Agents, Schwartz et al., pp. 463, 464, Interscience Pub. Corp., N.Y. (1949).
Hexylene Glycol, Pub. of Shell Chem. Corp., N.Y. (1950), pp. 8 and 15.