US2731422A - Non-soap detergent compositions - Google Patents

Description

United States Patent NON -SOAP DETERGENT COMPOSITIONS John Ross, Ramsey, N. J., assignor to Colgate-Palmolive Company, Jersey City, N. 1., a corporation of Delaware No Drawing. Application October 18, 1949, Serial No. 122,133

2 Claims. (Cl. 252-161) The present invention relates to new synthetic detergent compositions, and more particularly to compositions of the type of sulfated and sulfonated aliphatic acylcontaining detergents wherein the acyl radical has about 8 to 22 carbon atoms, having improved properties, and to a process for preparingthe same.

Various additives have been incorporated in a wide range of concentrations to modify the properties of synthetic detergent compositions in a desired manner. These additives individually may effect one or more of the following properties or mechanisms involved in the action of the detergent composition including foam volume, foam stability, dispersion, interfacial tension, modification of micellar structure,-etc. In view of the varied nature of many synthetic detergents, additives in general exhibit a certain degree of specificity of action.

While the exact relationship, if any, between detergency and foam is not known, it is preferred that the detergent composition should exhibit excellent foaming properties, particularly for consumer appeal and certain home and industrial uses. Accordingly, additives which improve foam and/or detersive efficiency of a detergent composition are highly desirable. In general, most testing conditions to determine the suitability of additives in synthetic detergents have revolved around the use of concentrations of detergent compositions of the order of 0.15, 0.2 and 0.25%.

It has now been discovered that the incorporation of minor amounts of fatty alcohols of about 10 to about 22, and preferably about 12 to about 18 carbon atoms in synthetic water-soluble sulfated and sulfonated aliphatic acyl-containing detergents having an acyl radical of about 8-22 carbon atoms, give improved foam stability and detersive power at certain selected washing concentrations.

The novel compositions of the present invention containing the selected fatty alcohols as additives do not show any significant increase in detergency and may even exhibit decreased detergency when employed in certain concentrations, in comparison to the use of these detergent compositions without the alcohol additives. It has been found, however, that within certain selected washing concentrations a marked and synergistic increase in detergency results from the use of the alcohol additives. It may be noted that the total washing power of any composition is necessarily the result of the amount of soil removal and soil suspension or redeposition. Additives in general may increase both soil removal and redeposition, or may change one such factor. It has been found, however, that the fatty alcohol additives in the compositions referred to herein have the desirable properties of both increasing soil removal and inhibiting soil redeposition, though the improvement in the former factor appears to be more pronounced.

1 With respect to the foamingproperties, it has been determined that the saturated fatty alcohols of about 14 to about 18 carbon atoms exert a highly beneficial and synergistic action on the foam stability of the compositions referred to herein, in comparison to the use of other alcohols as additives. The reason for this specificity of action is not known at this time.

The synthetic detergent compositions comprised by the invention contain as the active ingredient the surface active synthetic sulfated or sulfonated aliphatic acylcontaining compounds wherein the acyl radical has about 8-22 carbon atoms. Within the scope of such definition are the higher fatty acid ethanolamide sulfates; the sulphuric acid esters of polyhydric alcohols incompletely esterified with higher fatty acids, e. g. coconut oil monoglyceride monosulfate, tallow diglyceride monosulfate; the hydroxy sulfonated higher fatty acid esters, e. g. higher fatty acid esters of 2,3 dihydroxy propane sulfonic acid; the higher fatty acid esters of low molecular weight alkylol sulfonic acids, e. g. oleic acid ester of isethionic acid; and the like. More particularly, it is preferred to use the sulfated and sulfonated aliphatic carboxylic esters containing at least about 10 carbon atoms, especially those having about twelve to about twenty-six carbon atoms to the molecule, which may be derived from fatty oils, mono and di-glycerides, partial fatty acid esters and ethers of polyglycols, etc.

These detergents are commonly used in the form of their water soluble salts. Of these, the alkali metal (e. g. sodium, potassium) and ammonium salts are preferred though other salts such as the amine, alkylolamine, alkaline earth metal (e. g. calcium, magnesium) salts may be used if desired. Their concentration in the detergent compositions of the present invention is generally at least about 10, and preferably at least about 20% by weight of total solids. Compositions with very high concentrations of these active ingredients of the order of up to about are prepared for specialized uses generally. With built compositions, however, it is preferred to use an active ingredient content of about 20 to about 50%.

The fatty alcohols used as additives in the present invention are those of about 10 to 22, and preferably of about 12 to 18 carbon atoms. These essentially aliphatic alcohols may be primary or secondary; and saturated or unsaturated in character. It is preferred. however to use the saturated straight-chain primary alcohols of about 14 to about 18 carbon atoms. Examples of suitable alcohols falling within the broad classification are lauryl, myristyl, cetyl, stearyl, oleyl, palmityl, etc. It is not necessary to use the pure substances themselves as the commercial mixtures of these substances are also operable and may be preferred from the viewpoint of economy. Thus, commercial mixtures of fatty alcohols containing predominantly the desired fatty alcohols are included within the scope of this invention, even though such mixtures may contain minor amounts of fatty alcohols of different chain length.

The fatty alcohols may be derived either from natural or synthetic sources. Many naturally occurring wax esters are an important source of higher aliphatic alco hols. Certain animal oils, chiefly those of marine origin such as sperm oil, also contain a high proportion of re coverable alcohols occurring as esters. The most plentiful and economic sources for their production, however, are their preparation from fatty acids or aldehydes by reduction, or their recovery from oxidized petroleum stocks, etc., by processes known in the art.

These additives may be incorporated with the active ingredient at any point during the manufacturing process at which subsequent operations will not adversely modify effect on its foaming and detergency properties.

the properties 'of the detergent composition. In general, this addition may be accomplished by adding the alcohols to the active ingredient either in liquid form, or by mixing those materials which are solid under normal conditions in comminuted form. The best results are not achieved by mechanically intermixing the comminuted solid components. Avariety of procedures, which have proved to be convenient, economical, and productive of the best results arei 1. The addition of the fatty alcohols in 'a molten state to a hot aqueous slurry of the active ingredient of about 40 to 50% concentration with vigorous stirring to form a smooth, uniform and homogeneous paste.

2. The fatty alcohols may be dissolved in a suitable solvent, e. g. ethanol, and added to a slurry of the active ingredient.

3. A cream emulsion of the fatty alcohols in water with a minor proportion of the active ingredient may be prepared and incorporated into the slurry of active ingredient in the manner set forth above.

Thereafter, these compositions may be made up in the form of solutions, pastes, or as dry or partially hydrated solid products, preferably in a finely divided condition.

The amount of these added long chain alcohols is generally minor in proportion to the weight of the total detergent composition and sufficient to produce a marked Generally, the amount of each additive varies within rather definite proportions of the order of about i to about by weight since is has beenldeterrnined that within these somewhat critical limits the desirable effects appear to be attained to a maximum degree. With built compositions, it is preferred to useabouta 1 to about 5% concentration of alcohols.

With respect to detergency, it has been found that the fatty alcohol additives perform the dual function of increasing the soil removal power and of inhibiting the soil redeposition factor of the detergent compositions referred to herein. The unitary effect on detergency resulting from a concurrent activationof one factor and repression of another is of a synergistic character, since the fatty alcohols per se haveno deterging power. One of the most significant aspects of this improvement however is the fact that it may be noted only when used in a particular manner. The compositions of the present invention containing the free alcohols in general do not show any significant increase in detergency and even may exhibit decreased detergency when employed in washing concentrations of the order of 0.150.25%. It has been 'found, however, that under washing concentrations such as 0.40.75% a marked increase in detergency results from the use of these alcohols as additives.

These various results are evident from a consideration of the following data and examples described hereinafter which are merely illustrative of the present invention and it will be understood that the invention is not limited thereto.

Tables I and 11 indicate the changes in washing power at various bath concentrations in soft and hard water of a detergent composition containing 23% sodium salt of coconut oil monoglyceride sulfate as the active ingredient, 2% of a 90:10 mixture of cetyl and stearyl alcohol, 50% tetras'odiu'mpyrophosphate, 3% sodium silicate and 22% sodium sulfate.

The washing procedureinvolves the uniform soiling, washing at 110 RiZ" F. and drying of a large number of cotton swatches. The whiteness of the various test swatches are measuredby a Hunter reflectometer. The units of soil removed may be calculated by subtracting the average reflectivity of the unwashed control samples from the washed swatches. The effect on redeposi tion of soil in the fabric is determined by placing unsoiled samples in the detergent bath together with the soiled samples and measuring the brightness after washing. The numbers in the tables represent the change in units of soil removed and redeposited with the use of the above detergent composition with and without the fatty alcohol additives. A value indicates an increase in soil removal and redeposition; a value indicates a decrease in soil removal and lesser redeposition of soil.

Table l.--Soft water solutions Soil Re- S011 Redep- Percent Concentration moval 051mm Table II.--Hard water (300) p. p. m.) solutions It may be noted from the above data that no significant improvement in total washing power is attained either in hard or soft water using concentrations of 0.15 and 0.25%. .In fact, at low concentrations in hard water decreased detergency may result from the use of the alcohol additives. At higher concentrations however, a marked and synergistic increase in detergency results from the use of the fatty alcohol additives, particularly due to improved soil removal power. It is not completely understood why these additives in the relationship set forth should exhibit this unique specificity of action.

Though the sulfonated and sulfated detergent compositions referred to herein containing the alcohol additives may be used as a relatively pure mixture of these components, it is common however to employ various adjuvant materials in synthetic detergent compositions. These builders or additives may be inorganic or organic in structure, and may be admixed with the active ingredient in any suitable manner. Such adjuvant materials may include any of the substances employed by neutralize or remove the effectiveness of the fatty alcohols. It has been found that these added materials may vary greatly both in structure and in concentration without impairing the improved results of the compositions referred to herein.

Thus, such convenient inorganic builders or additives as the silicates, various alkali metal phosphates (e. g. hexametaphosphate, tetrapyrophosphate), the alkali metal sulfates, carbonates, etc., may be employed in these compositions. Organic materials such as carboxymethyh cellulose, esters (e. g. ethylene glycol monostearate, methyl palmitate), and the like may also be used under suitable conditions. 7 Y

Of the indicated vast variety of known builders and additives which may be employed in detergent 'cornp'ositions, it has been found that the water soluble polyphosphates in conjunction with the mixed organic additives have remarkable effects on the sulphonated and sulphated acy'l-containing detergent compositions. 'Thepolyphos phates are preferably the water soluble inorganic tri-polyphosphates of the formula:

M representing an alkali metal or ammonium group. vThe actions of the tri-polyphosphate and the fatty 5. alcohol additives in these detergent compositions are not only not antagonistic, but mutually contribute to a balanced detergency system such that a unitary result of vastly improved detergency is achieved thereby.

As previously indicated, the effect of the alcohol is primarily one of activation of the soil removal power of the detergent compositions referred to herein with a more moderate inhibition of the amount of soilredeposition. It has been determined however, that the tri-polyphosphates appear to exert beneficial results in an opposite direction in these detergency systems. The tri-polyphosphates exhibit their greatest effect on soil suspension or prevention of soil redeposition, and only to a minor extent on the soil removal factor. Since the total washing efficiency is due to a combination of both soil removal and soil suspension, it is apparent that the mixed additives of the organic fatty alcohols and the inorganic water soluble tri-polyphosphates mutually contribute to produce a somewhat balanced elfect since both the two factors of improved soil removal and lessened soil redeposition are activated concurrently to a significant degree.

These unexpected results are not achieved to the same degree when other phosphate compounds, such as tetrasodiumpyrophosphate (Na4P2O7) or tri-sodiumphosphate (NasPOr) are substituted for the tri-polyphosphates. It is not known at this time why the indicated washing mixtures with the tripolyphosphate should yield a markedly superior cleaning performance compared to mixtures with other phosphates in the detergent systems referred to herein.

These tri-polyphosphates may be used in any desired proportion. To some extent the degree of improvement appears to be proportional to its content in the composition. In general, the greater the percentage of tri-polyphosphate, the better the result where the active ingredient has been maintained constant. It has been found that best results are attainable when the ratio of tri-polyphosphate to the active ingredient is at least about 1:1. For maximum efliciency of these compositions, the active ingredient should be present in an amount at least about by weight of the total composition. A proportion of active ingredient from about 20% to up to about 50% with a similar proportion of the tri-polyphosphates and a minor amount of the higher fatty alcohols produces sufficient deterging properties for even heavily-soiled laundry; and such compositions are economical to prepare and convenient for use in the home or commercially.

The tri-polyphosphates may be incorporated with the active ingredient in any suitable manner. It is possible to mechanically intermix these constituents in the form of small solid particles. It is preferred, however, to apply the techniques set forth above for the introduction of the higher alcohols. Thus the tri-polyphosphates may be added to a slurry of the active ingredients before, during or after incorporation of the alcohols. The resulting mixtures may be dried in any convenient manner e. g. roll or spray dried. Excessively high temperatures during drying should be avoided however to prevent substantial decomposition of the polyphqsphates.

It is a significant feature of this invention that the long chain saturated primary alcohols of at least about 14 carbon atoms exert a beneficial effect on the foaming properties of the synthetic non-soap aliphatic acyl-containing sulfated and sulfonated detergents wherein the acyl group has 8 to 22 carbon atoms. The desirable effect of these fatty alcohols on the foam of such detergents as the fatty acid monoglyceride sulfates, fatty acid ethanolamide sulfates, etc., is unique and in marked contrast to the general adverse effect on foam produced by these alcohols on other sulfonated and sulfated detergents.

These fatty acyl-containing detergent compositions containing the fatty alcohol additives are characterized by increased stability of the foam produced in washing operations in comparison to the foam effects produced by 6 these compositions without the fatty alcohol additives. The fact that these alcohol adducts in the particular relationship set forth produce foams and suds which are more stable, do not readily break down by evaporation, have in general longer drainage time and contain more liquid, are significant and desirable properties for a detergent composition.

Moreover, it has been found that in general, the alcohol adducts in these compositions tend to increase the tolerance of these detergent compositions in the assimilation or holding in suspension of a maximum amount of dirt, grease, etc., with less foam loss than is found without the use of these additives.

The effects on the foaming characteristics can be studied quantitatively for a given composition by means of a foam consistency test. Briefly, this test consists of the formation of a foam by standardized agitation of 500 cc. of a detergent at F. in a two quart unsilvered Dewar flask. The foam formed after a 10 minute agitation period is then measured with a consistometer after standing for 5, 10 and 15 minutes. The readings are an indication of the foam consistency or bodying effect. It has been arbitrarily determined using a standard consistometer that a value below about 275 units represents relatively low viscosity, a value of 275-350 units intermediate consistency, and above 350 units is high consistency.

This consistometer is a means for measuring the mini mum torque necessary for rotation of a paddle of any standard size through a foam. This device applies the torque by means of a coil spring which has its inner end attached to a paddle shaft and the outer end attached to a circular plate which can be rotated. The degrees through which the spring may be twisted before the paddle starts to move in the foam may be readily determined. An indicator needle is attached to the top of the paddle shaft and a circular scale divided into 360 is set on the plate which holds the outer end of the spring. The paddle shaft is held in place by a pair of ball bearing races in such a way that it can turn freely.

A foam consistency test is conducted in distilled and in hard water using a detergent composition comprising essentially 30.9% coconut oil monoglyceride sulfate salts, 7.5% sodium phosphates, and the remainder sodium sulfate with and without alcohol additives. The results using 0.25% concentration of the detergent composition are set forth in the tables below. The values given therein represent the averages of the three readings at 5, 10 and 15 minute intervals.

The data in the table above indicate the remarkable effectiveness of the saturated straight-chain primary alcohols of 14 to 18 carbon atoms as foam stabilizers on such detergent compositions. It may be noted thatdodecanol containing 12 carbon atoms is ineffective to increase the foam consistency. Tetradecanol and octadecanol give intermediate to high foam consistency. The hexadecanol appears to represent an optimum in regard to chain length. It is also evident moreover, that combinations of fatty alcohols consisting essentially of C14 to C13 are effective in improving the foam stability of the detergent composition.

57 The. improved. results are also observable 1 in .hard water as-disfclosedf'in'TableIIbelow:

ksynthetic'mixtures ;of fatty,alcohols corresponding to fatty acid competitions or the indicated fats and oils.

.It iseVident-that the:fatty ,alcohols containingessentially CIA-.Cl-B alcohols-are highly effective to improve :the .foam .consistency in .hard water. .It vmay .be noted that synthetic mixtures of these :alcohols corresponding to ..the.fatty acid scompositionof various fats :an'd oils which predominate .in fatty acids of :14 to 18 carbon atoms arealso highly effective in the relationship set forth. lnnumber 7 of .Table -II, -a 2:1 mix of hydrogenated tallow and coconut .oilalcoholsis used to determineif thepresence .ofzminor amountsof coconut oil alcohols predominating ,inxcl2 :alcohols would neutralize the effectiveness .ofthehigher homologues. ltmay be noted that snchajmixture maintains relativelyhigh consistency inhard water,.thereby indicating that minor'but significant .amounts.of alcohols of less-than 14 carbon atoms-may baa-incorporated in the fatty alcohol mixtures used to .give improved. results.

The beneficial results derived .using the-organic aciditives referred to herein are: exhibited with varying concentrations -of active ingredients as set forth in Table III.

TABLEIII Composition Fqam Consistency ALL, 4Cetyl alcohol, SG'NaiSOr 380 A; I., 4 Cetylalcohol; 8I-Na' SO4 440 A. L, 4. Cetyl alcohol, 76 NazSOi. 420 40 A 1., 4 Cetyl alcohol, 56 NfiZSO-l 4 10 60 A L, 4 Cctyl alcohol, 36 NaQSO. 430 80 A. 1., 4 Cetyl alcohol, 16 NazSOe 430 TABLE IV Consistency .Additive Percent in Distilled Water lfiflNone 220 :2. Lorol 1 '5 .225 3. Tetradecanol 2 130 "4. HexadecanoL. 2 410 :5. 'OctadeeanoL. 2 370 6. Oleylalcohbl. 5 220 L 1 Fatty'alcohol'mixturdderivedfrom coconut' oil.

Tt'is evidenfifrom'the datain'the table ,iaoove fthatithe saturated -fattyalcohols. of .14 .to 18-. carbon atoms aresuperior'foam stabilizing agents.

EXAMPLE .I

The .foam :consistency test is repeated on a detergent composition comprising 40% of the condensateofcoconut-oil fatty acids withisethionic acid as .the active ingredient-and 2% lauryl alcoholas-t'ne .organicadditive. .This detergent composition exhibits a foamconsistency 05230. -With the;substitution.of..2%cetyl alcohol as the organic-additive, however, thereis obtained a foam consistency valueof 360.

"EXAMPLE '11 Using .a'0.25% .concentration in distilled water of a detergent-composition comprising 40% of the condensate dfcoconut oil fatty acids with methyl taurine .and "60% sodium sulfate, there is obtained a foam consistency value of .220. "With .the addition of 5% 'lauryl alcohol a consistency value o'f2'20is.also obtained. Using\2.%.

cetyl alcohol as .the organic additive, improved foam stability ,is obtainedsince the detergent composition. has a consistency value .o'f1390.

EXAMPLE I II Usingan 0.25% concentration in distilled water of a detergent composition comprising 30% magnesium coconutoil monoglyceride .monosuifate as the active ingredient, there'is obtained a foam consistency value of .230. With the addition of 2% 'cetyl alcohol, a'foam consistency valueof 410 is obtained thereby indicating improved ioamstabilityidueto.thepresence of the alcohol additive.

.Certain, general conclusions. are. apparent. from. the. many tests which'have been conducted to determine the effectivenessof the long chain fatty alcohols inthe relationship set forth. The mostappropriate fattyalcohol and its .mostefiective concentrationfor each particular sulphonate d or sulphated carbonyl-containing detergent composition may. suitablybedetermined by routine controls. lneachcase the intended use (e. g. hard or soft water, hair shampoos-or machine Washing compositions, etc.) and the proper washing conditions should be taken into consideration in order to derive the maximum-beneiicial effects.

Theterm consisting essentially of as used in the definition of the ingredientspresent in'the composition claiinedis intended to. excludethe presence of. significant amounts ofother syntheticdetergents and OfOthBIimaterialsin such amounts asto interfere substantially with the properties and characteristics possessed. by the composition set forthzbut to permit the .;presence of other materials inssuch amounts as not. substantially to affect said properties and characteristics adversely.

Although the present invention has been described with reference to particular embodiments'andtexamples,

it willbeapparent to those skilled inthe art that variations and modifications of this invention can be made and that equivalents can'be substituted therefor Without departing from the principlesand true spirit-of the invention.

Having described theinvention, what is desired to be secured by Letters Patentis:

1. A detergent composition consisting essentially of a water-soluble higher fatty acid monoglyceride monosulfate detergent having about"8-22 carbons in the fatty acyl group, and'in minorproportion thereto and from about lto-a'bout 10% by-weight of a primary'saturated monoh-ydric'fatty alcohol of about 14 to 18 carbon atoms.

2. A detergent composition consisting "essentially 0f a :water-soluble higher fatty acid monoglycer-ide monosulfateidetergent having aboutB-ZZ carbons in the fatty :aryl .group, .and :in :.minor zpro'portion' thereto and from about Tl rtoieabout :by weight:ofcetylraicohol.

7 (References on. following .page) References Cited in the file of this patent UNITED STATES PATENTS 2,166,314 Martin July 18, 1939 2,366,027 Henke Dec. 26, 1944 5 2,396,278 Lind Mar. 12, 1946 10 Strain Nov. 1, 1949 Miskel Aug. 15, 1950 Preston Oct. 24, 1950 FOREIGN PATENTS Great Britain Apr. 19, 1937

Claims (1)

1. A DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF A WATER-SOLUBLE HIGHER FATTY ACID MONOGLYCERIDE MONOSULFATE DETERGENT HAVING ABOUT 8-22 CARBONS IN THE FATTY ACYL GROUP, AND IN MINOR PROPORTION THERETO AND FROM ABOUT 1 TO ABOUT 10% BY WEIGHT OF A PRIMARY SATURATED MONOHYDRIC FATTY ALCOHOL OF ABOUT 14 TO 18 CARBON ATOMS.