US2708183A - Long-chain urea compounds in detergent compositions - Google Patents

Description

United States Patent LONG-CHAIN UREA COMPOUNDS 1N DETERGENT COMPOSITIONS John Ross, Ramsey, N. J., assignor to Colgate-Palmolive Company, Jersey City, N. J., a corporation of Delaware No Drawing. Application May 2, 1951, Serial No. 224,264

12 Claims. (Cl. 252-137) The present invention relates to new synthetic detergent compositions, and, more particularly to compositions of the type of the anionic sulfated and sulfonated detergents having improved properties.

There has been a considerable amount of research to discover substances or additives which aid the eflicieucy of detergent compositions. The problem is exceedingly complex, however, in view of the various physico-chemical mechanisms or properties and the like involved in the action of a detergent composition including suspension, interfacial tension, micellar structure, dispersion, foam stability, etc. and the general difliculty usually in determining the particular mechanism which is being altered by changes in the formulation of detergent compositions.

During recent years, synthetic detergents of the type of the organic sulfates and sulfonates have been developed which have properties which render them highly advantageous for certain uses. In general, the exploration for suitable additives or builders for synthetic detergent compositions of the type of the anionic sulfates and sulfonates has been directed by the requirements of increased foaming and/or detersive power. While the exact relationship, if any, between foaming and detergency is not known, it is highly desirable that these detergent compositions exhibit excellent foaming properties, in addition to a high level of detersive efficiency, particularly for consumer appeal and certain home and industrial uses. In view of the complex nature of both the foam and detergency phenomena, the character of such non-soap synthetic detergents, and the many other variables in detergent compositions, additives in general exhibit a certain degree of specificity of action.

Urea and certain lower derivatives thereof have been used with certain surface-active agents chiefly in large proportions as cheap and innocuous fillers and as solubilizing agents. Certain other derivatives have been used as intermediates in the manufacture of resins, plastieizers, emulsifying agents, pharmaceuticals, etc.

It has now been discovered that the presence of a substituted urea having a long-chain alkyl radical in detergent compositions consisting essentially of anionic sulphated and sulphonated detergent is effective to achieve a significant enhancement in surface-active properties such as detergency and foaming. More particularly, the improved detergent compositions consist essentially of water-soluble sulphated or sulphonated detersive salts, and as an organic builder 2. minor proportion of a higher alkyl substituted urea effective to enhance the action of the detergent composition in aqueous solution. These improvements are unique since such urea derivatives by themselves have poor foaming and deterging properties, and thus are valueless as cleaning agents per se.

Illustrative of the enhancing additives of the present in vention are the higher alkyl substituted urea compounds characterized by limited water-solubility. These derivatives may be additionally substituted with low-molecular weight aliphatic radicals, such as lower alkyl and alkylol groups. The higher alkyl substituent may be branched 2,708,183 Patented May 10, 1955 or straight-chain in structure; it comprises moreover such groups as octyl, docyl, dodecyl, keryl, pentadecyl, and hexadecyl, mixed long-chain alkyls derived from longchain fatty materials, cracked paraffin wax olefins, polymers of monoolefins, etc. This higher alkyl substituent will generally be from at least about 8, generally up to about 18 carbon atoms, and preferably about 10 to about 14 carbon atoms.

Included within the ambit of the invention is the following preferred class of compounds suitable as additives which may be represented by the structural formula:

wherein R is a long-chain higher alkyl radical. Suitable examples of such compounds are octyl urea, decyl urea, dodecyl urea, cocyl urea wherein the cocyl substituent is a mixture of essentially long-chain alkyls derived from mixed coconut oil fatty acids, dodecyl urea wherein the dodecyl group is derived from a propylene tetramer, teradecyl urea, myristyl urea, pentadecyl urea wherein the pentadecyl group is derived from a propylene pentamer, hexadecyl urea, etc.

An additional suitable class is the polyalkyl substituted ureas having one alkyl group long-chain in structure as indicated, and at least one lower alkyl group. The lower alkyl groups should have a total generally of not in excess of about six carbon'atoms. It is preferred that each lower alkyl group be not in excess of about three carbon atoms each. These polyalkyl derivatives may be symmetrical or unsymmetrical. Specific examples Within this class are N dodecyl, N methyl urea; N dodecyl N methyl urea; N dodecyl, NN' dimethyl urea; N tetradecyl N ethyl urea; etc.

A further class is the higher alkyl substituted ureas having at least one lower alkylol group, the carbon atom range being the same as with the lower alkyl groups. The alkylol group may be monoor polyhydroxy in structure. Suitable examples are N dodecyl N methylol urea; N dodecyl N ethanol urea; N dodecyl NN diethanol urea; N dodecyl N butanol urea; N tetradeeyl N 2, 3 dihydroxy propyl urea; etc.

These various urea derivatives may be prepared in any suitable manner and numerous processes for the production of alkyl ureas, mixed polyalkyl and alkyl-alkylol ureas, etc., and their analogues are Well known in the art.

The novel compositions of the present invention contain as the active ingredient the anionic sulphated and sulphonated detergents, including suitable mixtures thereof. Included therein are the aliphatic sulphated or sulphonated agents, such as the aliphatic acyl-containing compounds wherein the acyl radical has about 8 to about 22 carbon atoms, and, more particularly, the aliphatic carboxylic ester type, containing at least about 10 and preferably about 12 to about 26 carbon atoms to the molecule. Among the aliphatic detersive compounds, it is preferred to use the sulphated aliphatic compounds having about 12 to about 22 carbon atoms. As suitable examples of aliphatic detergents may be found the sulphuric acid esters of polyhydric alcohols incompletely esterified with higher fatty acids, e. g. coconut oil monoglyceride monosulphate, tallow di-glyceride monosulphate; the long chain pure or mixed higher alkylsulphates, e. g. lauryl sulphate, cetyl sulphate, higher fatty alcohol sulphates derived from coconut oil; the hydroxy sulphonated higher fatty acid esters, e. g. higher fatty acid esters of 2,3 di-hydroxy propane sulphonic acid; the higher fatty acid esters of low molecular weight alkylol sulphonic: acids, e. g. oleic ester of isethionic acid; the higher fatty acid ethanolamide sulphates; the higher fatty acid amides of amino alkyl sulphonic acids, e. g. lauric amide of taurine, and the like.

It is a feature of this invention that the effects are particularly enhanced with the alkyl aryl sulphonate detergents. These aromatic sulphonate detergents are also known in the art. They may be mononuclear or polynuclear in structure. More particularly, the aromatic nucicus may be from benzene, toluene, xylene, phenol, cresols, naphthalene, etc. The alkyl substituent on the aromatic nucleus may vary Widely, as long as the desired detergent power of the active ingredient is preserved.

More specific examples of suitable alkyl aromatic sulphonate detergents are the higher alkyl aromatic sulphonates. The higher alkyl substituent may vary in the. manner described for such groups in the higher alkyl urea additives. Thus, it may be branched or straightchain in structure, and comprise decyl, dodecyl, keryl, mixed long-chain alkyls from polymeric lower monoolefins, etc. Preferred examples of this class are the higher alkyl mononuclear aryl sulphonates wherein the alkyl group has about 8 to about 22, and preferably about 12 to about 18 carbon atoms. More particularly, it is preferred to use the higher alkyl benzene sulphonates wherein the higher alltyl group averages about 12 to about 16 carbon atoms. For example, propylene may be poly.- merized to the tetramer and condensed with benzene in the presence of a Friedel-Crafts catalyst to yield essentially the dodecyl benzene derivative which is suitable for sulphonation to the desired sulphonate compounds.

These various anionic detergents are generally used in the form of their water-soluble salts, such as the alkali metal, alkaline earth metal, ammonium, amine, and

- alkylolamine salts. While the sodium, potassium, am-

monium and alkylolamine (e. g. mono-, di-,' and triethanolamine) salts are preferred ordinarily, other salts such as the lithium, calcium, and magnesium salts may be used if desired. For general use, it is ordinarily preferred to use the sodium and potassium salts. For certain specialized uses, it may be preferred to select the ammonium and alkylolamine salts in view of their generaliy greater solubility in aqueous solution. The concentration of these water-soluble salts (including suitable mixtures thereof) in the detergent compositions of the present invention is generally at least about 10% by 1 weight of total solids, and preferably from about l50%.

With'built compositions, particularly in particulate form, an active ingredient content of 10-50%, and preferably about l40% yields highly satisfactory results. Compositions With very high concentrations of these active ingredients are prepared for specialized uses generally. Thus in liquid detergent compositions, any suitable concentrations may be employed, e. g. 90% of total solids or about 20 to about 60% of theweight of the total'liquid detergent composition.

The amount of the substituted urea additives in the detergent composition is generally minor in proportion to the weight of die active ingredient and effective in producing the desired improvements in detersive capacity and/or foaming power.

to about 2:1. It is preferred that the additive be from about 5 to about of the active ingredient. In particulate detergent compositions the additive will usually be from about /2 to about 15% by weight of the detergent composition. Particularly effective results have been achieved wherein the additiyes are present in amounts of the order of about 1 to 10% of the total detergent composition. It is preferred usually to use about 1-5% additive however. The optimum amount of additive and its ratio to the active ingredients will vary according to the specific materials, the contemplated field of application and manner of use.

The additives may be incorporated with the active ingredient at any point during the manufacturing process 7 Generally, the proportion of active ingredient to additive should be from about:l

at which subsequent operations will not adversely modify the properties of the detergent compositions. A variety of procedures which have proved to be convenient, economical, and productive of best results are: the additives may be added to a hot aqueous slurry of about 40 to 50% solids concentration comprising the active ingredient with vigorous stirring to form a smooth, uniform and homogeneous paste, the additives may be dissolved in a suitable solvent and added to the slurry of the active ingredient, a mixture or emulsion of the additives in Water with a minor proportion of the active ingredient may be incorporated into the slurry, or the additive may be incorporated in the detergent composition by a post treatment to spray-dried detergent particles, etc.

Thereafter, these compositions may be prepared in the form of solutions, pastes or as dry or partially hydrated solid products, preferably in a finely divided condition. It is preferred to prepare the products in particulate form. Accordingly, the slurry of the detergent composition may be subjected to any suitable drying operations and converted to particle form. The mixture may thus be subjected to conventional spray-drying, roll-drying or drumdrying operations utilizing temperatures above, about 212 F. to obtain homogeneous detersive particles.

The additives, exert their primary detersive effects on an activation of the soil removal power. Such results may be illustrated by the application of soil removal tests, using a testing procedure which involves the uniform soiling, washing with particular detergent compositions at F. :2 F., and drying of a large number of cotton swatches. The whiteness of the various test swatches is measured by a Hunter reflectometer. The units of soil removed may be calculated by subtracting the average reflectivity of unwashed control samples from the washed swatches. The results'on soiled wool swatches may be determined using substantially the same testing procedure.

Table I indicates thepercent increased reflectance as a measure of improved soil removal, on cotton and wool swatches using a standard detergent composition consisting essentially of 20% sodium salts of dodecyl benzene sulfonate (the dodeeyl group being derived from a propylene tetramer), 40% sodium tripolyphosphate, 3% sodium carbonate and 37% sodium sulfate at 0.4% concentration in soft tap water, with and without added cocyl urea additive. The percentages listed in'the table for each concentration of additive represent the percent change in whiteness reflectance using an standard the above detergent composition without organic additive. A value indicates the approximate improved whiteness reflectance as a measure of improved soil removal and a value represents decreased soil removal in comparison to the standard.

The marked improvement in soil removal due to the presence of the substituted urea additives is evident from the data. It is apparent that on cotton soil, optimum'results are achieved using about 2-5% of the additive with this particular detergent composition. On wool soil, the

effects are much more marked, with synergistic improvement effected at all concentrations and optimum results at 3-10% additive. The significance of the presence of these additives is even more striking since the above compositions containing the additive and about 20% detergent is much more effective generally in soil removal than compositions containing for example 35% detergent without the additive.

However, for each specific type additive, as for each detergent composition, there is an optimum proportion or concentration which may be determined by routine tests. A few representative additives in the identical detergent composition referred to above yield the following results by the same procedure:

Table II 0.25% concentration at 115 F. with the number of greased plates washed by the formula A without additive being taken as a standard of 100%. The result with gfi'iggfiii Formula B is tabulated in terms of percent of thestand Additive Percent Cotton Wool Table IV Foam 2 +15 +30 Endurance 1. Dodecyl urea 3 +34 +50 Composition in Dish- 4 +29 +56 washing, 2. Decyl urea 2 +10 +38 percent 2 ii iii Octyl urea 7 $15 +42 A 1oo 10 +74 B Another feature is that the improved results may be 30 The unusual effect obtained by Composition- B conexhibited both in hard and in soft water, and over a wide range of washing concentrations. While additives in general exert widely variable effects in hard and soft water, the novel compositions of the present invention are effective in both types, thereby enlarging their field of application to a great degree. The wide range of suitable washing conditions under which the improved results are obtained is significant also since it permits economy of use and allows a wide latitude to the consumer and the like as to suitable quantities to be employed.

Table IH illustrates the percent improvement in soil removal at 0.25%, 0.4%, and 0.75% concentrations of the self same detergent composition in hard water of 300 p. p. m. hardness using only 1.5% of dodecyl urea additive on cotton swatches.

Table III Percent Concentration of Detergent Composition gig? Removal 0.25 percent..... +10 0.40 percent +6 0.76 percent +9 The results are even more marked using other selected percentages of additives and wool swatches.

From the viewpoint of foaming generally, the novel compositions of the present invention are characterized by increased stability of the foam produced in washing operations in comparison to the foaming effects produced by compositions without the additive. The foam of the present compositions has good creaminess and consistency, does not readily break down by evaporation, has in general a longer drainage time, and contains an increased amount of liquid.

It has also been found that the present combinations tend to increase the tolerance of the detergent composition for 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 the desired additives.

In practical dishpan tests wherein greased dishes are washed by hand in a dishpan of water containing a small amount of the detergent composition, the compositions is considerably slower on solutions of the present com-..

positions than with corresponding solutions of the detergent compositions without the desired additives.

Table IV discloses comparatively the average results.

in foam endurance or duration obtained in thedishwashing of various greased plates with two compositions. Formula A contains 25% sodium salts of coconut monoglyceride monosulfate detergent as the active ingredient, 10% diacid disodium pyrophosphate and 65% sodium sulfate. A second formula (B) has 3% dodecyl ureaadded thereto. The tests are conducted in hard water at cedure comprises conducting the pour foam test in the presence of a small amount of soil. The pour foam test is designed for comparative study of the relative foam stability of liquids and is set forth in U. S. Patent No. 2,315,983 to Ross and Miles. The foam height in millimeters of solutions tested in accordance with the Ross et al. patent at various time intervals is an indication of the foam stability in the presence of soil.

The above test is conducted at 0.25% concentration of detergent composition in distilled water, using separately three compositions. Composition I is the detergent formula set forth in Table I containing 20% sodium dodecyl benzene sulfonate, Composition II contains 1.5% dodecyl urea added to I, and Composition III has an active ingredient content of 35% and a corresponding reduction in the amount of sodium sulfate is made accordingly. The following results are achieved:

Thus it may be noted that Composition II containing the urea type additive exhibits a high level of foam stability for the full time interval, whereas the foam generated by Formula I with no additive collapsed completely within 5-10 minutes. The synergistic effect of the additive herein is all the more striking in relation to the effects achieved with Formula III containing a vastly increased active ingredient content.

It is common to employ various adjuvant materials in synthetic detergent compositions. The detergent compositions of the present invention may include any' of these substances employed bythe art in admixture 7 13* be a minimum of at least about with such detergent compositions generally, provided the use of any such materials, does not completely neutralize or remove the effect of the substituted urea type additives in the relationship set forth. These adjuvant builders or additives may be inorganic or organic in structure and may be mixed with the active ingredient ispreferred that the detersive compositions in particu late, form contain major amounts of alkaline builders, particularly the inorganic water soluble phosphates. The total amount of phosphate compounds should usualand preferably from about 10 to about 80% by the weight of the detergent composition for optimum results. A detergent composition containing anamount of active ingred'ient of about 15 to 50% with the requisite minor proportion of substituted urea. additives and about to about 60% total phosphate compounds, particularly wherein sodium tripolyphosphfite is present in, substan: tial quantities exhibits highly desirable properties In liquid detergents, the active ingredient should preferably be in the form of a highly water soluble salt, e. g. ammonium, mono-, diand triethanol amine salts. The liquid detergent composition may be prepared in dilute or concentrated aqueous solution with or without the presenceof a lower molecular weight aliphaticalcohol such as ethyl alcohol, propylene glycol, etc.

The following examples are additionally illustrative of the nature of the present invention and it will be understood that the invention is not limited thereto:

Example I A detergent composition is prepared by forming about a 6.0% solids slurry containing on a solids basis about 35% sodium propylene tetramer benzene sulfonate salt, 40% sodium tripolyphosphate, 15% sodium sulfate, 3% dodecyl urea, and the remainder minor amounts of sodiumchloride, sodium hydroxide, sodium carboxy-methylcellulosc, etc. This slurry-is agitated at about 140 F. in a conventional soap crutcher to form a homogeneous mixture. The slurry is submitted to spray-drying- With heated air at a temperature of about 350 F. with a resultant moisture loss of about 40%. The resulting composition is recovered in the formof beads, and possesses a high degree of detersive and foamingproperties in both hard and soft Water.

Example 11 Example III Usingthe procedure of Example I an improved detergent composition is prepared from the following components: 20% sodium lauryl sulfate, 40% sodium ably determined by routine controls.

8 Example V Per cent Sodium coconut alcohol sulfates 16 Sodium chloride 1 Sodium tripolyphosphate 38 Tetrasodiumpyrophosphate 15 Sodium sulfate 2.! N dodecyl N hydroxyethyl urea 3 Example VI Per cent Sodium dodecylbenzene sulfonate 9 Sodium lauryl sulfate 1 0 N dodecyl N methyl urea 3* Sodium carboxymethylcellulose 0.5 Sodium carbonate 1.5 Sodium sulfate 20 Sodium tripolyphosphate 44 Tetrasodium pyrophosphate 12 Example VII Per cent Higher fatty acid amides of taurine derived from.

coconut oil 25 Sodium sulfate" 30 Sodium tripolyphosphate 42 Dodecyl urea 3 Certain general conclusions are apparent from the many tests which have been conducted to determine the. effectiveness of the substituted urea additives in the relationship set forth. The most appropriate additive and its most effective concentration. a for each particular sul'-' phonated, or sulphated detergent composition may be suit.- In, each case the intendeduse (e. g. hard or soft water, rug shampoos or machine washing compositions, etc.) and the proper washing, conditions should be taken into. consideration in.

order to derive the maximum beneficial effects.

The term consisting essentially of as used in the.

definition of the ingredients present in the composition claimed is intended to exclude the presence .of other materials in such amounts as to interfere substantially with the properties and characteristics possessed by the composition set forthbut to permit the presence of other materials in such amounts as not substantially to effect said properties and characteristics adversely.

Although the present invention has'been described with reference to particular embodiments and examples, it will be apparent to those skilled in the art that variations and modifications of this invention can be made and that equivalents can be substituted therefor Without depart ing from the principles and true spirit of the invention.

Having described the invention what is desired, to be secured by Letters Patent is: r

1. An improved synthetic detergent composition-consisting essentially of a detergent selected from the group consisting of the, water-soluble anionic organiosulphate and sulphonate detergents and a minor proportionof a. urea derivative represented by the formula:

wherein R is a higher alkyl radical of about 10 to about:

. 14 carbons, said minor proportion. being sufiicient to-irntripolyphosphate, 38% sodium sulfate, and 2% dodecyl urea.

Example IV Another suitable detergent composition is prepared by compounding 25% sodium coconut monoglyceride sulfate, 10% diacid, disodium pyrophosphate, 62% sodium sulfate and 3% N decyl N hydroxyethyl urea.

Other formulations productive of desired results are:

prove the soil removal power thereof.

wherein R is a higher alkyl radical, the amountof said urea compound being sufiicient to enhance the effect of.

:said detergent composition in solution.

3. An improved synthetic detergent composition in particulate form consisting essentially of a water-soluble higher alkyl aryl sulphonate detergent salt and a urea compound represented by the formula:

wherein R is a higher alkyl radical, the proportion of said sulphonate salts to urea compound being from about 50:1 to about 2:1 and sufiicient to enhance the effect of said detergent composition in solution.

4. An improved heat-dried synthetic detergent composition consisting essentially of about 10 to about 50% water-soluble alkyl aryl sulphonate detersive salts, about 10 to about 80% Water-soluble alkali metal phosphates, and a substituted urea compound represented by the formula:

wherein R is a higher alkyl radical, the amount of said urea compound being from about /2 to about 15% and L suflicient to enhance the effect of said detergent composition in solution.

5. An improved synthetic detergent composition consisting essentially of a water-soluble aliphatic sulphated detergent, and a urea compound represented by the formula:

wherein R is a higher alkyl radical, the proportion of said detergent to urea compound being from about 50:1

to about 2:1 and suflicient to enhance the eifect of said detergent composition in solution.

6. A detergent composition consisting essentially of a water-soluble detergent selected from the group consisting of the anionic organic sulphate and sulphonate detergents, and a minor proportion of a compound selected from the group consisting of higher alkyl ureas having the formula:

RNHCONH2 wherein R is a higher alkyl radical, and their nitrogensubstituted lower alkyl and lower alkylol derivatives sufficient to improve the soil removal power thereof.

7. A detergent composition consisting essentially of a water-soluble detergent selected from the group consisting of the anionic organic sulphate and sulphonate detergents, and about A to about 15% by weight of a compound selected from the group consisting of higher alkyl ureas having the formula:

wherein R is a higher alkyl radical, and their nitrogensubstituted lower alkyl and lower alkylol derivatives.

8. A detergent composition consisting essentially of a water-soluble detergent selected from the group consisting of the anionic organic sulphate and sulphonate detergents, and a minor proportion of a substituted urea derivative represented by the formula:

wherein R is an alkyl group of 10 to 14 carbon atoms. 11. A detergent composition consisting essentially of a water-soluble higher alkyl sulfate detergent, and about /2 to about 15% by weight of a compound represented by the formula:

RNHCONH2 wherein R is an alkyl group of 10 to 14 carbon atoms.

12. A detergent composition consisting essentially of a water-soluble higher fatty acid monoglyceride sulfate detergent, and about /2 to about 15% by weight of a compound represented by the formula:

wherein R is an alkyl group of 10 to 14 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTS Jacobson Aug. 17, 1937 Swain Aug. 5, 1941 Flett Apr. 24, 1945 FOREIGN PATENTS France Jan. 11, 1936

Claims (2)

1. 4. AN IMPROVED HEAT-DRIED SYNTHETIC DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF ABOUT 10 TO ABOUT 50% WATER-SOLUBLE ALKYL ARYL SULPHONATE DETERSIVE SALTS, ABOUT 10 TO ABOUT 80% WATER-SOLUBLE ALKALI METAL PHOSPHATES, AND A SUBSTITUTED UREA COMPOUND REPRESENTED BY THE FORMULA
2. 6. A DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF A WATER-SOLUBLE DETERGENT SELECTED FROM THE GROUP CONSISTING OF THE ANIONIC ORGANIC SULPHATE AND SULPHONATE DETERGENTS, AND A MINOR PROPORTION OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF HIGHER ALKYL UREAS HAVING THE FORMULA