US 3812041 A
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3,812,041 NON-GELLING HEAVY DUTY LIQUID LAUNDRY DETERGENT Jack Thomas Inamorato, Westfield, N.J., assignor to Colgate-Palmolive Company, New York, N.Y. No Drawing. Filed June 23, 1972, Ser. No. 265,721 Int. Cl. Clld 1/83 US. Cl. 25289 17 Claims ABSTRACT OF THE DISCLOSURE A clear non-gelling liquid synthetic organic heavy duty laundry detergent composition comprising a nonionic detergent having the molecular configuration of the condensation product of a higher fatty alcohol and ethylene oxide, an anionic detergent higher fatty alkyl polyethenoxy sulfate, a brightening agent, water and a lower monohydric alcohol. Small proportions of sequestering agents and salt-forming bases may also optionally be present in the composition. The detergent composition is a single phase clear stable liquid but may be made opaque, creamy or opalescent if desired. Furthermore, the composition is substantially neutral or only slightly alkaline when measured at a 1% concentration in water and cleans soiled laundry to a degree comparable with that obtained utilizing phosphate built alkaline detergents. In addition, the liquid detergent composition is biodegradable.
This invention relates to a substantially neutral liquid detergent useful for heavy duty laundering of soiled clothing and other cloth or fabric articles. More particularly, this invention relates to a substantially builder-free clear biodegradable liquid detergent composition which functions comparably to conventional phosphate built or nitroliotriacetate built commercial heavy duty laundry detergents.
In recent years there has been a sharply increasing awareness of possible disruptive effects on the ecology attending discharge of various pollutants into ground waters, streams, rivers and lakes. Particularly undesirable is the large ,scale discharge of compounds which persist in the environment and adversely affect the quality of our waters. As a resultof governmental and individual concern, manufactures of detergent compositions are attempting to eliminate non-biodegradable synthetic organic detergent materials, i.e. branchedchain alkyl benzene s'ulfonates, as the organic surface active agents in commercially available'household laundry detergents. Along with such research, there are extensive efforts to replace the'polyphosphate builder constituents in such detergent compositions so that the wash water discharge from household and commercial laundries will not cause possible accumulations of phosphates in rivers and lakes.
-The elimination of these polyphosphates from commercial and household detergents has not been-without its attendant difliculties since these materials have very desirable building, sequestering and soil-suspending activities and the removal of these materials from the detergent compositions results in significant losses in cleaning power. A detergent composition comprising only active synthetic organic detergents does not produce the same cleaning effect as a combination of these detergents and the polyphosphates. At the present time, the only substitute for the polyphosphates which appears to be approximately equal with regard to building and soil-suspending eflects are the nitrilotriacetic acids and acetates often referred to as NTA.
The present liquid'detergents are based on a combination of an ethoxamer sulfate and a nonionic detergent both of which are readily biodegradable. Utilization, however, of non-ionic detergents, although biodegradable, is
United States Patent 3,812,041 Patented May 21, 1974 not without its attendant drawbacks. The use of non-ionic detergents in liquid detergent composition must be balanced against the tendency of these materials to gel upon standing in open contact with the atmosphere. Furthermore, some of these non-ionic detergents subsequent to prolonged contact with the atmosphere are not readily dispersible in water and gel upon contact with the same. In accordance with the composition of the present invention, however, it has been found that by utilizing certain specific non-ionic detergents this gelling phenomenon is reduced or eliminated altogether, thereby permitting nonionic biodegradable detergents having detersive properties similar to prior art alkaline built detergent compositions to be prepared in the-absence of polyphosphates and other inorganic builder salts or alkaline materials. Although the composition of the present invention may include a small amount of NTA, or the like, acting as a metal sequestrant, to prevent discoloration of the products and laundry washed, these small amounts of NTA and the like do not have any building effect on the overall composition.
In the clear liquid products, various constituents aid in solubilizing other components so that the product is clear and concentrated yet readily pourable. Furthermore, repeated test washings indicate that the cleaning power of the biodegradable detergents is approximately equivalent to other commercial built detergent compositions in cleaning action against realistic body soil and actual laundering tests in home laundry washing machines and against mixed loads under various conditions.
It is within the above environment and background that the novel composition of the present invention was developed. Briefly, such composition comprises a non-ionic detergent, at least 50% of the non-ionic detergent comprising a lower molecular weight non-ionic having the formula RO(C H O),,H, wherein R is an alkyl group, preferably a straight chain alkyl group having from 10 to 15 carbon atoms, R generally is in the form of a mixed alkyl and may comprise either one specific chain length or a mixture of up to all six, n is selected from 6 to 11' with the proviso that n' is from about /5 to about 3 of the average number of carbon atoms in R; the remainder vention to provide a non-gelling heavy of the non-ionic detergent comprises a higher molecular weight non-ionic having the formula RO (C H O),,H,' wherein R is an alkyl group preferably a straight chain alkyl group averaging from 14 to 20 carbon atoms and n is a number of from 10 to 14, n being from'about -to 1 times the number of :carbon atoms in R; an anionic ethoxamer sulfate, i.e. polyethenoxy sulfate of the formula RO(C H O),,SO M wherein R is a fatty alkyl of from 10 to 20 carbon atoms, n is from 2 to 6 and preferably from /5 to /3. of the number of carbon atoms in R and M is a salt-forming ion usually selected from alkali metals, ammonium, lower alkylamino or lower alkanolamino; a minor proportion of a fluorescent brightener system that is normally at least partially water-soluble; water; and an alcohol with the proportion of the non-ionic and anionic detergents, fluorescent brightener system, water and alcohol bring such that the insoluble fluorescent brightener is substantially in solubilized form.
It is therefore the primary object of the present induty liquid laundry detergent.
It is a further object of the present invention to provide a biodegradable liquid detergent which is stable on st'and ing when it is exposed to the atmosphere.
It is a still further object of the present invention'to provide a heavy duty liquid detergent containing substantially no builders with a cleaning proformance substantially equal to alkaline phosphate built detergents.
Still further objects and advantages of the composition of the present invention will become more apparent from the following more detailed description thereof.
The novel liquid non-gelling detergent which is devoid of phosphate and nitrogenous builders of the present invention comprises from 25% to 75% weight percent of a non-ionic detergent, this non-ionic detergent comprising from 100% to 50% by weight of the non-ionic of a low molecular weight non-ionic of the formula RO(C H O),,H wherein R is an alkyl group preferably having a straight chain from 10 to 15 carbon atoms and n is a number from 6 to 11 with the proviso that n is from /5 to of the average number of carbon atoms in R, and from to 50% by weight of the non-ionic of a high molecular weight non-ionic of the formula RO(C H O),,H wherein R is an alkyl group preferably having a straight chain of from 14 to 20 carbon atoms and n is a number of from 10 to 14, n generally comprising 4 to 1 times the number of carbon atoms in R; from to 25 by weight of an ethoxamer sulfate of the formula wherein R is a fatty alkyl of from to 20 carbon atoms, n is from 2 to 6 and preferably from /s to /3 of the number of carbon atoms in R and M is a salt-forming ion generally selected from alkali metals, ammonium, lower alkylamino or lower alkanolamino, the total non-ionic and anionic in weight ratio of from :1 to 1:1 0.5 to 5% by weight of a fluorescent brightener system which is generally at least partially water-soluble, 5 to 35% by weight of water and 5 to 35% by weight of a lower alkanol.
The synthetic organic detergents utilized in the present invention which provide the concentrated clear liquid detergent composition with its non-gelling characteristics comprise the lower molecular weight non-ionic condensation products of a fatty alcohol with ethylene oxide or ethylene glycol optionally containing a small proportion of propylene glycol. Normally, this condensation will be with ethylene oxide which is cheaper and does not require the removal of by-product water. Methods for the manufacture of such compounds are well known and these materials have been previously employed in detergent compositions, although generally their use has been limited to being part of the entire active organic detergent portion of light duty liquid detergents. The low molecular weight non-ionics which provide the composition of the present invention with the non-gelling characteristics are of the formula RO(C H O),,H wherein R is an alkyl group preferably having a straight chain of from 10 to 15 carbon atoms and n is from 6 to 11 with the proviso that n is from Vs to V of the average number of carbon atoms in R. Generally, due to the methods of manufacture, mixed alkyls are employed and for the composition of the present invention to have the desired non-gelling characteristics it is preferred to utilize mixed alkyl chains wherein the chain length averages approximately 12. Furthermore, the ethylene oxide which reacts with these mixed alkyls 'will also vary somewhat Within the abovenoted range of from 6 to 11. The ethylene oxide content can vary within this range as long as the amount of ethylene oxide in the final product is within the parameter of from /s to of the average number of carbon atoms in the alkyl group. Since it is critical to maintain the proper balance of fatty alkyl chain length and ethylene oxide chain length within the above-noted ranges in order to obtain good detersive properties together with the nongelling property and compatibility with other materials, it has been found and is a preferred embodiment of the present invention to utilize a non-ionic detergent of the above formula wherein R is a mixed straight chain alkyl having from 10 to 15 carbon atoms, the average number of carbon atoms averaging approximately 12, and n is from 6 to 9 with the proviso that n is from V5 to V5 of the average number of carbon atoms in R. Preferred nonionics which have a minimum of gel characteristics include Neodol 25-7 (R equals mixed 12-15 carbon atom alkyl, n equals 11 average value) made by Shell Chemical Company and Pluorofac B-26, the reaction product of a linear alcohol with a mixture of ethylene and propylene oxides, made by Wyandotte Chemical Company.
The non-ionic detergent portion of the heavy duty liquid detergent of the present invention may also contain up to 50% of a high molecular weight non-ionic detergent of the formula RO(C H O) H wherein R is a straight chain alkyl of from 14 to 20 carbon atoms and n is from 10 to 14 with the proviso that n is from tol times the average number of carbon atoms in R. As with the lower molecular weight non-ionics which impart the non-gelling characteristics to the composition of the present invention, these higher molecular weight non-ionics are also produced by reacting mixed alkyls with ethylene oxide chains which include different chain lengths within the 10 to 14 ethylene oxide radical range. Within this range, as noted above, there is a desirable hydrophilic-lipophilic balance which is necessary in order to obtain good detersive properties together with other desirable properties and compatibility with other detergent composition ingredients. Generally, the alkyl group will be from 14 to 16 carbon atoms and usually the average carbon content of preferred compounds are from 14 to 15 and in the most preferred higher molecular weight non-ionic detergent compositions for use with the lower molecular weight nonionies, the alkyl groups will be over 14 to 15 carbon atom chain lengths. Similarly, it is preferable to have from 10 to 12 ethylene oxide radicals per chain and in a most preferred embodiment these will average about, and very preferably be equal to about 11 ethylene oxide units-per chain. A preferred higher molecular weight non-ionic to be utilized in the composition of the present invention is Neodol 45-11 (R equals mixed 14 to 15 carbon atom alkyls, n equals 11 average value) made by Shell Chemical Company. The desired hydrophilic-lipophilic balance is maintained by keeping n equal to about to 1 times R.
In addition to the chain lengths of the hydrophilic-lipophilic portions of the high molecular weight and low molecular non-ionic detergents described above for best detergency and biodegradability it is important that such portions be of certain configurations. Of necessity, the ethylene oxide chain will be linear and terminated by a free hydroxyl. Also, as in the case of Pluorofac B-26, some mixed chains of ethylene oxide and propylene oxide may be utilized although pure ethylene oxide chains are generally preferred. The alkyl groups also most preferably will be linear although a minor degree of slight branching such as at a carbon next to or two carbons removed from the terminal carbon of a straight chain and away from the ethoxy chain, may be tolerated provided that such branched alkyl portion is of no more than 3 carbon atoms in length. Usually, the portion of carbon atoms in such branched configuration will be quite minor, rarely being more than 20 or 10% of the entire alkyl content of carbon atoms. Also, although linear alkyls which are terminally joined to the ethylene oxide chains are highly preferred and result in best detergency, biodegradability and other important properties including non-gelling characteristics, medial or secondary joinder to the ethylene oxide in the chain may occur in a minor proportion of such alkyls and generally such proportion will be less than 20% and preferably less than 10% thereof. With regard to the inclusion ofminor quantities of propylene oxide in the ethylene oxide chain, it is preferred that the ethylene oxide chain consists essentially of ethylene oxide, generally over 80% and preferably over thereof.
The composition of the present invention also includes an anionic detergent. Such anionic detergent is a sulfated ethoxylated higher fatty alcohol of the formula RO(C H O),,SO M
wherein R is at fatty alkyl of from to 20 carbon atoms, n is from 2 to 6, being from A to /3 of the number of carbon atoms in R and M is a solubilizing salt-forming cation such as an alkali metal, ammonium, lower alkylamino or lower alkanolamino. As with the non-ionic detergents, this anionic detergent is most readily biodegradable and of better detergency when the fatty alkyl is terminally joined to the polyoxyethylene chain, which, of course, is terminally joined to the sulfur-forming sulfate group. Again, although slight branching of the alkyl chain may be tolerated to the extent of not more than 10% of the carbon atom content as noted above with regard to the non-ionic detergents, this minor deviation from the linear structure is to be especially avoided in the anionic detergents. Furthermore, medial joinder of the alkyl group to the polyoxyethylene chain should be minimal, less than 10%, and even such joinder then should be preferably concentrated near the end of the alkyl chain. Within the 10 to 20 carbon atom alkyl groups, the preferred alkyls are of 12 to carbon atoms and those which are most preferred are mixed alkyls containing 12, 13, 14 and 15 carbon atom chains. The mixture is preferably one containing at least 10% of each chain length and no more than 50% of any one chain length.
The ethylene oxide content of the anionic detergent is such that n is from 2 to 6 and is preferably from 2 to 4, generally averaging about 3, especially when R is a mixed 12 to 15 carbon atom alkyl. To maintain a desired hydrophilic-lipophilic balance, when the carbon content of the alkyl chain is in the lower portion of the 10 to range, the ethylene oxide content might be reduced so that n is about 2, whereas when R is of 16 to 18 carbon atoms, n may be from 4 to 6. The salt-forming cation may be any suitable solubilizing metal or radical but will most frequently be alkali metal or ammonium. If alkyl-amine or lower alkanolamine groups are present, alkyls and alkanols thereof will usually contain one to four carbon atoms and the amines and alkanolamines may be mono-, dior tri-substituted, e.g. monoethanolamine, diisopropanolamine, trimethylamine.
The importance of using the correct anionic detergent in the present compositions is shown by the failure of corresponding alcohol sulfates in similar liquid detergent compositions to wash as well as the present compositions containing the described higher alcohol-ethylene oxide sulfates. For example, a higher alcohol sulfate in which the alcohol is mixed 12 to 15 carbon atom alcohol, exhibits a significantly poorer detergency in liquid compositions like those of the present invention, compared to the corresponding ethoxylated sulfate in the same composition. Even within the preferred range of alcoholethylene oxide sulfates, an improvement in detergency is noted for the compositions which include a mixed 12 to 15 carbon atom alcohol-ethylene oxide sulfate, when compared to other higher alcohol-ethylene oxide sulfates, such as a mixed 14 to 15 carbon atom alcohol-ethylene oxide sulfate of the same ethylene chain length. The preferred detergent is available from Shell Chemical Company and is'identified by them as Neodol 3S, the sodium salt, normally sold as a 60% active material, including about 40% of aqueous solvent medium, of which a minor proportion is ethanol. Although Neodol 25-38 is the sodium salt, the potassium salt and other suitable soluble salts may also be used either in partial or complete substitution for that of sodium.
Examples of the higher alcohol polyethenoxy sulfates which may be used as the anionic detergent constituent of the present liquid composition or as partial substitutes for this include: mixed C normal primary alkyl triethenoxy sulfate, sodium salt; myristyl triethenoxy sulfate, potassium salt; n-decyl diethenoxy sulfate, diethanolamine salt; lauryl diethenoxy sulfate, ammonium salt; palmityl tetraethenoxy sulfate, sodium salt; mixed C1445 normal primary alkyl mixed triand tetraethenoxy sulfate, sodium salt; stearyl pentaethenoxy sulfate, trimethylamine salt and mixed C1048 normal primary alkyl triethenoxy sulfate, potassium salt. Minor proportions of the corresponding branched chain and medially alkoxylated detergents, such as those described above but modified to have ethoxylation at a medial carbon atom, e.g. one located four carbons from the end of the chain, may be employed but the carbon atom content of the higher alkyl will be the same. Similarly, the joinder of a normal alkyl may be at a secondary carbon one or two carbon atoms removed from the end of the chain. In either case, only the minor proportions previously mentioned will be present.
For most of the heavy duty liquid detergents it will be unnecessary and undesirable to utilize active detergent ingredients other than the high and low molecular weight non-ionics and anionic combination described above. Yet, for some applications minor proportions of supplementary detergents may be used. These will generally be of the nonionic type although in some formulations other anionic, cationic, amphoteric or ampholytic detergents or surface active agents of known types may be employed. For example, there may be used higher fatty acid esters of polyethylene glycols, block copolymers of ethylene oxide and propylene oxide, higher alkyl-di-lower alkyl amine oxides, the sodium salts of the sulfuric acid derivatives of higher fatty alcohol condensation products with ethylene oxide, triethanolamine lauryl sulfate, straight chain alkyl sulfonates, sodium lauroyl sarcoside, cetyl trimethylammonium bromide, benzethonium chloride, dimethyl dibenzyl ammonium chloride, N-higher alkyl N,N- di-lower alkyl aminopropane sulfonates, amidosulfobetaines, betaines and amidobetaines. Descriptions of such additional detergents may be found in the text, Synthetic Detergents, by Schwartz, Perry and Berch, published in 1958 by Interscience Publishers, New York, see pp. 25- 143. It will be kept in mind that such materials will be employed only for specific purposes and in small proportions, compared to the detergent combination of the low and high molecular weight higher fatty alcohol-ethylene oxide non-ionics and the alkyl-ethylene oxide sulfate anionic and will usually be used when a specific cleaning property thereof is desirable for a particular application.
The fluorescent or optical brighteners or whiteners employed are important constituents of modern detergents which give washed laundry and materials a bright appearance so that the laundry is not only clean but also looks clean. Due to the variety of synthetic fibers incorporated in the textiles which are made into clothing and other items of laundry and the importance of substantivity of the brightener compound to the fibers, many different fluorescent brightening compounds have been made, which may be incorporated in the present detergent compositions, often in mixtures. Of course, brighteners, suitable for use on cotton, and brighteners which are stable in the presence of oxidizing bleaches are also of importance. Therefore, although it is possible to utilize only a single brightener for a specific intended purpose, in the compositions of the present invention it is generally important to utilize a mixture of brighteners which will have good brightening effects on cotton, nylons, polyesters, and blends of such materials and which, additionally, are bleach stable. A good description of such types of optical brighteners is given in the articles, Optical Brighteners and Their Evaluation, by Per S. Stensby, a reprint of articles published in Soap and Chemical Specialties in April, May, July, August and September 1967, especially at pp. 3-5 thereof.
The cotton brighteners, frequently referred to as CC/ DAS brighteners because of their derivation from the reaction product of cyanuric chloride and the disodium salt of diamino-stilbene disulfonic acid in molar proportion of 1:2 are bistriazinyl derivatives of 4,4'-diaminostilbene-2,2'-disulfonic acid. In most cases, the CC/DAS 7 is reacted with two moles of aniline or sulfanilic or metanilic acid and the product is additionally substituted on the 'triazine rings. Such compounds are of the general formula: I
wherein X may be either hydrogen or SO Na and the Rs may be those derived from aniline, morpholine, N-methylethanol amine or diethanolamine. Because some heavy duty laundry detergents will be employed in conjunction with bleach, a bleach stable brightener, usually a benzidine sulfone disulfonic acid, a naphthatriazolylstilbene sulfonic acid or a benzimidazolyl derivative will be used. These compounds are of the formulas:
SIO Na SOaNa wherein R may be hydrogen, lower alkyl, lower alkanol, lower aminoalkanol, anilino, morpholino, etc. The polyamide brighteners, especially good for nylons, are usually either aminocoumarin or diphenyl pyrazoline derivatives. Unfortunately, neither of these is especially stable in the presence of chlorine bleaches. The compounds are of the formulas given below and the R and the R groups thereof may be previously listed as substituents on the optical brighteners discussed earlier, while X and Y may include such substituents as halogens and lower alkyls.
The polyester brighteners, which are becoming of more importance as polyesters are being used to a greater extent in an increasing proportion of textiles are usually of one of the following formulas, wherein R, X andY have the meaning previously given and Z may be selected from the group of X and Y substituents. These brighteners also usually serve to 'whiten polyamides.
The brighteners are used in their acid forms or as salts. They may be employed as solids or in solutions and may be cut with a carrier powder. Although the chemical and physical forms can affect brightening actions, if the compounds are used in soluble forms brightening activities for the same compounds on an active ingredient basis will be equivalent. In the present compositions and in the wash waters resulting, the brighteners are maintained sufiiciently soluble so as to be effective and uniformly substantive to the materials of hte laundry being washed.
Among the brighteners that are used in the present systems are: Calcofiuor White ALF (American Cyanamid); ALF-N (American Cyanamid); SOF A-200l (CIBA); CDW (Hilton-Davis); Phorwite RKH (Verona); CSL, powder, acid (American Cyanamid); PE 766 (Verona); Blancophor PD (GAF) UNPA (Geigy) Tinopal RBS (Geigy); and RES 200 (Geigy). The acid or nonionic forms of the brighteners tend to be solubilized by alcohols of the present formulas, while the salts tend to be water soluble. *lhus, a combination of such solvents and the detergent combination serve to keep the fluorescent brighteners dissolved.
The lower alkanol employed is preferably either ethanol of isopropanol but can be any lower monohydric alcohol. Of the two preferred alcohols ethanol is most preferred because of a slightly greater solubilizing power and more pleasant odor. If ethanol is used, it will normally be denatured and of the denatured alcohols those identified as SD40 or 3A are preferred. However, other denatured alcohols may also be used. The alcohols need not be anhydrous and the small proportions of water normally present with them are considered to be part of the water components of the liquid detergents. Some or all of the alcohol may be replaced with dihydric or trihydric lower alcohols which, in addition to having solubilizing powers and reducing the flash point of the product, also can act as anti-freezing constituents and may improve compatibilities of the solvent system with particular product components. Among these compounds, the most preferred group includes the lower polyols of 2 to 3 carbon atoms, e.g. ethylene glycol, propylene glycol and glycerol, but the lower alkyl (C -C etheric derivatives of such compounds known as Cellosolves, may also be employed, generally to only a minor extent.
The water used is preferably deionized so that it will be low in content of ions which can form insoluble compounds. However, ordinary tap water can be used providing that the hardness thereof is sufiiciently low so that in the formula employed there is no detrimental precipitation out of salts on standing. When sequestrants are present, hardness will be less important and in such cases even waters with hardnesses over 300 parts per million equivalent calcium carbonate can be acceptable. Generally, however, the water hardness should be less than p.p.m. and most preferably, less than 50 p.p.m.
The sequestering agent, when used, may be any suitable compound, including the aminopolycarboxylic acids and hydroxycarboxylic acids. Thus, ethylene diamine tetraacetic acid, nitrilotriacetic acid, hydroxyalkyl derivatives thereof in which the hydroxyalkyl group replaces one or more acetic acid groups, gluconic acid, ascorbic acid, glucono-delta-lactone (which is converted to gluconic acid), citric acid, lactic acid and salts thereof, especially those of the water soluble alkali metals, e.g. sodium, potassium, etc, ammonium, alkanolamines and amines, may be used. Other sequestering or water-softening agents of the inorganic type such as certain phosphates may be used in very small amounts if desired but are not present in amounts suflicient to have a builder function.
Adjuvants may be present in the liquid detergent to give it additional properties, either functional or aesthetic. Thus soil suspending or anti-redeposition agents, may be used such as, polyvinyl alcohol, sodium carboxymethyl cellulose, hydroxypropylmethyl cellulose; enzymes, e.g. protease amylases; thickeners, e.g., gums, alginates, agar agar; hydrotropes, e.g. sodium xylene snlfonate, ammonium benzene sulfonate; foam improvers, lauric myristic diethanolamide; foam destroyers, e.g. silicones, bactericides, e.g. tribromosalicylanilide, hexachlorophene; fungicides; dyes; pigments (water dispersible); preservatives; ultraviolet absorbers; fabric softeners; pearlescing agents; opacifying agent, e.g. behenic acid; polystyrene suspensions, and perfumes. Of course, such materials will be selected for the properties desired in the finished product and to be compatible with the other constituents thereof.
The pH of the heavy duty liquid detergent composition will normally be substantially neutral or only slightly alkaine. The composition of the present invention contains a minimum of akaline material per se, since the particulate soil removal of the particular non-ionic and anionic detergents utilized is enhanced in approximately neutral solutions. However for various reasons, such as solubilizing and neutralizing various brighteners used, a small amount of an alkaline material may be included. Suitable alkaline materials include mono-, diand trialkanolamines, alkylamines, ammonium and alkali hydroxides. The preferred alkali materials are the alkanolamines, especially the trialkanolamines and most especially triethanolamine. A pH reading of the liquid detergent using a glass electrode and a reference calomel electrode, indicates a maximum pH of about 8. However, because the detergent system is essentially non-aqueous despite the presence of a minor proportion of water, the pH reading obtained may be false. A better indication is obtained by measuring the pH of a 25 solution in water. This should usually be in the range of about 6.8 to 8.8. In water containing items to be laundered the pH will normally be within the same range.
The proportion of the various components of the present heavy duty liquid detergents are important to the obtainment of a uniform product and acceptable heavy duty laundering action. In the absence of a significant builder content, it is very important that the product contain a significant proportion of detergents. So as to promote solubility of the fluorescent brighteners and other constituents and make a clear, homogeneous and readily pourable liquid product, from 25 to 75% of the total liquid detergent concentrate should be non-ionic fatty alcohol-ethylene oxide condensation products in a mixture of from 100% to 50% by weight of non-ionic of low molecular weight non-ionic and from to 50% by weight of high molecular weight non-ionic as described above. The preferred range is from 30 to 60% of total nonionics and in the most preferred embodiment of the invention about 40% is employed. It is preferred that the non-ionic mixture comprise a significant portion of low molecular weight non-ionic since the non-gelling properties of this material are more effective at higher concentrations. According, it is preferred to utilize a non-ionic mixture of from 100% to 75% by weight of the non-ionic of low molecular weight non-ionic and from 0 to 25% by weight of the non-ionic of high molecular weight nonionic, and it is most preferred to use all low molecular weight non-ionic. For the greatest effectiveness, the quantity of the anionic ethoxamer sulfate detergent should be within the range of about 5 to 20% and preferably about A of the total non-ionic content, i.e. preferably 10%. Suitable weight ratios of total non-ionic to anionic ranges from about 15:1 to 1:1 with 8:1 to 2:1 preferred and 5 :1 to 3 :1 most preferred.
The concentration of fluorescent or optical brightener or whitening agent in the product will be from about 0.5 to 5% on an active ingredient basis, preferably about 1 to 3% and most preferably about 2%. Such quantities are readily solubilized in the clear liquid product and contribute substantially to brightening of fabrics in the laundry. Generally, 25% and preferably at least 50% of the optical brightener content will be a brightener for cotton. It is preferred to use about 51 to 90% of a cotton brightener, with the balance being one or more of polyamide brighteners, polyester brighteners, and chlorinestable brighteners.
The lower alcohol will generally be present in a sufficient proportion to aid in stabilizing or dissolving various constituents of the product such as the brighteners. The proportion employed will generally be from 5 to 35%, preferably from 5 to 25 When used without supplementing diol or triol, the quantity of alcohol present normally is from 5 to 20% but when the supplementing polyol is used the content of alcohol may be reduced to from 5 to 15%, preferably about 5 to 10%. In such circumstances, the proportion of polyol will generally be from 5 to 15 most preferably 10%. The percentage of water utilized will also generally be from 5 to 35% and a preferred range is from 5 to 25 with a most preferred range being from 15 to 20%. Similar considerations prevail in determining the proportion of water to be employed as do in the case of the alcohols.
The non-building proportion of sequestrant, when used, may range from 0.2 to 3,%, preferably from 0.5 to 1.5%, and most preferably 0.8%.
Considering the wide range of adjuvants which may be utilized, for widely different purposes, the quantities or proportions thereof employed will vary. Generally, however, it may be said that the total thereof should not exceed 10% and will preferably be maintained less than 5% and more preferably less than about 3%. Individual components should usually not exceed 5% preferably 3% and more preferably 1% of the product. The use of more of such compounds will often significantly change the properties of the liquid detergent and, therefore, is to be avoided.
The heavy duty liquid detergents of the present invention can be made by simple manufacturing techniques which do not require any complicated equipment or expensive operations. In a typical manufacturing method, the optical brighteners may be slurried in the monohydric alcohol or mixture of monohydric and polyhydric alcohol. If initially slurried in the monohydric alcohol, subsesequently the polyhydric alcohol, if used, may be added to this. Then water and, if necessary, a small amount of base such as triethanolamine is added, which helps to partially dissolve the previously suspended material but not yield a clear solution. Addition of the detergent combination causes the remainder of the brightener to dissolve to make a clear solution. Then the sequestrant, if used, may be added as the acid or salt (preferably the sodium, potassium or amine salt) and agitation is continued until the solution becomes clarified, which will normally take about 5 to 10 minutes. At this point perfume and dye may be added to give the product its final desired appearance and odor. All of the operations may 'be effected at room temperature, although suitable temperatures within the range of 10 to C. may be employed, as desired. Additions of adjuvants may be efiected at suitable points in the process but for the most part these will be added to the final product. The product obtained will usually have a pH within the range of from 6.5 to 8, e.g. 7.0 and a density within the range of from 0.9 to 1.1, preferably from 0.95 to 1.05 and most preferably from 0.98 to 1.02. The viscosity of the product at 25 C., will usually be from 20 to 200 centipoises, preferably from 50 to 150 cps., and will be in the higher part of this range if a polyhydric alcohol is used in replacement of some lower monohydric alcohol.
Use of the present compositions is marvelously simple and eificient. Compared to present heavy duty laundry detergent powders, much smaller volumes of the present liquids may be employed to obtain cleaning of soiled laundry. For example, in a typical and preferred formulation of this invention, containing about 40% of the fatty alcohol-ethylene oxide condensate and ethoxamer sulfate, only about 2 ounces or A cup of liquid need to be used for a full top-loading automatic machine tube of d wash, in which the water volume might be from 15 to 18 gallons. Thus, the concentration of liquid detergent in the wash water is on the order of 0.1%, 1 gram per liter or 1,000 parts per million. Generally, the proportion employed will be from 0.7 to 1.5 grams per liter, which may correspond to 0.3 to 0.6 g./l. of the mixture of fatty alcohol-ethylene oxide condensation products, from 0.075 to 0.15 g./l. of ethoxamer sulfate, from 0.01 to 0.05 -g./l. of the fluorescent or optical brightener, from 0.05 to 0.4 g./l. of lower monohydric alcohol and from 0.005 to 0.03 g./l. of organic sequestrant. The proportions of other constituents of the liquid compositions may vary accordingly. Of course, equivalent results can be obtained by using larger proportions of a more dilute liquid deter-gent but the greater quantity needed will require additional packaging and shipping space and will be less convenient for the consumer to use. However, it is considered that the use of such more dilute products is within the present invention if the relative proportions of components is maintained. In other words, the present invention is not avoided by merely preliminarily diluting the liquid detergent with wash water also serves to dilute the detergent down to a water since the same end result is obtained because the use concentration.
Although it is preferred to employ wash water of reasonable hardness and at an elevated temperature, the present invention is also useful in laundering clothes and other items in hard waters and in extremely soft waters, as well as in waters at room temperature or below. Thus, water hardnesses may range from 0 to over 300 parts per million as calcium carbonate and washing temperatures may be from 10 C. to 80 C. Preferably, the temperatures will be from room temperature, 20 to C., to 70 C. Also, although washing will ordinarily be effected in an automatic washing machine, with the washing followed by rinse and spin or draining or wringing operations, it is contemplated that the detergent may also be used for hand washing of laundry. In such cases, the concentration in water of the liquid detergent will often be increased and sometimes it may be full strength to assist in washing out otherwise difficult to remove soils or stains. After completion of the washing and spinning operations, it will be general practice to dry the laundry in an automatic dryer soon thereafter but such particular drying operation is not necessary.
When the liquid detergent is added to water, whether that water is hot or cold, the detergent immediately dissolves uniformly throughout the wash water, even in the absence of significant agitation. Washing and brightening agents are carried into contact with all the laundry and there are no localized over-concentrations of either of these materials. The clothing washed, following normal methods, is exceptionally clean and in compartive tests the product has been rated as good as some of the best commercial heavy duty detergents on the market. Al-
though it is a lowand non-foaming detergent composition and thus very suitable for side-loading washing machines, excellent washing is also obtained in top-loading machines in which foaming detergents are normally employed. Repeated testing of soiled and re-soiled laundry items, using the present compositions and larger quantities of commercial heavy duty detergents built with phosphate or NTA, show that the soilings are repeatedly removed and no objectionable build-up thereof occurs. For the most part, users do not note any really significant differences between the washing properties of the present composition and commercial compositions tested. In fact, there has been a significant preference for the present product.
If the low molecular weight non-ionic detergents are omitted from the composition and replaced with higher molecular weight non-ionic detergents having a similar hydrophilic-lipophilic balance, the liquid composition gels within a short period of time when exposed to the atmosphere. Furthermore, the liquid detergents without sufficient low molecular weight non-ionic, i.e. at least 50% of the non-ionic detergents, to retard or eliminate this gelling do not disperse properly in water after exposure to the atmosphere. If the liquid detergent gels and does not disperse properly in water, this causes the brighteners to be concentrated in small areas causing uneven and splotchy brightening.
The discovery of the present compositions and their exceptionally good properties was unexpected because those skilled in the art have not expected to be able to make an unbuilt heavy duty laundry detergent composition without the use of inorganic builder salts or EDTA or NTA substitutes for such builders. This was especially surprising in view of the previous use of the present organic detergents only as light duty cleaning agents, since their ability to remove soil from laundry in heavy duty applications was unappreciated. Also, it was a conclusion contrary to that formerly reached by many other research workers in the field of detergency. The use of the compositions of the present invention without NTA has no adverse effect on the substantivity of the optical brighteners whereas sequestrants of the NTA or polyphosphate types can interfere with the even deposition of brighteners on laundry. As a matter of fact, surprisingly, outstanding whiteness values are obtained by the unique combination of the instant non-ionics and anionics. The detergent does not react with hypochlorite bleaches whereas NTA can undergo such reactions. Finally, the various constituents of the detergents, as was previously mentioned, help to mutually solubilize one another and form a flowable clear liquid, The alcohols and water solubilize the brightener system and the detergent condensate aids in producing best solubility and a clear product. The low molecular weight non-ionic prevents the liquid detergent from gelling. Gel prevention means stain prevention, because otherwise staining of the wash could occur due to deposits of gel holding the brightcner to only some parts of the laundry. This detergent liquid is easily biodegradable and does not add quantities of phosphate or substitute NTA builder to the wash water.
The composition of the present invention will now be more fully illustrated by the following specific examples which are illustrative and in no way limitative of the present composition wherein all parts and percentages are by weight and temperatures in degrees Fahrenheit unless otherwise noted.
EXAMPLE 1 A clear, liquid detergent having the following formula is prepared by slurrying the mixture of optical brighteners in SD-40 alcohol followed by the addition of water and triet hanolamine with stirring. Subsequently, the Neodol 25-7 and the Neodol 25-3S is added and after a few minutes of agitation at moderate speed the solution becomes clear.
13 RO(C H O)-;H (Neodol 25-7, R=mixed 12, 13, 14 and 15 carbon atoms primary alkyl) RO(C I-I O) SO Na (Neodol 25-3S, R=mixed 12, 13, 14 and 15 carbon atoms primary al- 1 A: 4,4 bis[(4-anilino 6 methylamino-Striazine-2-yl) amino]2,2-stllbenedisulfonic acid; dlsodium salt.
3:4,4. bis[(4-anllino-6-[bis(2-hydroxy-ethyl)arnlnol-S- triazine-2-yl)amino]-2,2'-stilbenedisulfonic acid, disodium salt. C=4-naphthotrlazolyl-2-stilbenesulfonic acid, sodium salt.
4 D:2- (1,3dsoindazo1e) -2- (naphth [1,2d] oxazole) stilbene.
The pH of a 25% solution of the above formulation in water is about 7.0. This liquid detergent which is a sparkling, clear, free-flowing liquid is then packed in polyethylene plastic bottles of substantially cubic shape and of one quart capacity and is ready for use. Storage tests indicate that this product Will be stable for several years without precipitation of insoluble salts, settling into a plurality of phases, clouding or other disadvantageous effects on appearance or function.
Furthermore, if the above formulation is allowed to sit in contact with the atmosphere, the same will not gel even after 18 hours exposure to the air and further after exposure to the air, when poured into hot or cold Water, is readily dispersed therein.
Detergency and brightening power of the liquid detergent composition is evaluated in control tests wherein the experimental formula is compared with various commercial heavy duty ecology type laundry detergents. In these tests, cloths are intentionally soiled with a mud soil and washed in identical washing machines (Terg-o-tometer)"using the same Water and recommended amounts of the experimental and various controlled detergents. The soiled cloths are collected and divided so that'the experimental and controlled formulas are used to Wash similarly soiled loads of laundry. Such testing is repeated and the whiteness of the various washed cloths are compared each time by Reflectometer. Results of these tests in both hot and cold washing water conditions are listed in Table 1.
TABLE 1 120 F. conditions Rd. values Product Cone. 1st wash 2d wash Example 1 0. 09 82.5 83. 7 0. 30 67.5 67.8 0.30 63.1 60. 5 0.175 70.0 V 66. 5 0.26 52. 3 56. 7 0. 15 74. 9 78. 2
70 F. conditions Example 1 0. 09 80 4 78. 4
' Exam 1e: conlpanson p 0. 175 72. 2 70. 0 0.30 73. 7 74. 9 0. 26 59. 2 64. 1
In the above-noted table, the higher Rd. or Refiectometer values indicate a whiter wash. From the abovenoted table it is clear that the product of Example 1 cleans better at a lower concentration than other commercially available ecology type, i.e. biodegradable and non-phosphate containing, detergent compositions. Furthermore, the formulation of Example 1 cleans better at a lower wash water concentration as exhibited in Table 1 14 which shows that a concentration of only 0.09 is necessary as opposed to up to 0.3 for some other ecology type detergents.
From the above it is apparent that the present formulation can be utilized in a concentration which corresponds to approximately cup per 16-gallon automatic washing machine tube and that at such concentration the liquid detergent favorably compares with other washing products wherein concentrations corresponding to 1% cups of spray-dried heavy duty laundry detergents must be used. Furthermore, Reflectometer readings of Whiteness when the formulation of Example 1 is compared against various laundry detergents built with polyphosphates show no significant difference between the detergents. Furthermore, subjective evaluations of the product in consumer tests using a panel of housewives result in a significant preference for the liquid detergent.
Since no builder is utilized, it has been theorized that particulate soil could accumulate on washed items, however, subsequent to repeated washings shows that the laundry detergent of Example 1 compares quite favorably with the phosphate detergents with regard to particulate soil removal.
EXAMPLE 2 A series of liquid detergent compositions are produced utilizing the basic formula of Example 1 where in the Neodol 25-7 is replaced with the following non-ionic detergents:
(A) C1243 alcohol-+6.5 moles of ethylene oxide (B) C1245 alcohol-F9 moles of ethylene oxide ((3) C alcoh0l+6 moles of ethylene oxide (D) C alcohol-l-S moles of ethylene oxide (E) Wyandotte Plurofac B-26 1 (F) Jefferson Chemical Co. Surfonic L4 1 (G) C1445 alcohol-H1 moles of ethylene oxide (H) C1448 alcohol+11 moles of ethylene oxide (I) C1645 alcohol+ 11 moles of ethylene oxide (J) C alcohol-H2 moles of ethylene (K) 1:1 mixture of C +11 EO and Pluorofac B-26 mixture Of C16 18+11 and C12 13-6.5
1 Linear alcohol+a mixture of ethylene and propylene oxide.
. When each of the above-noted detergent formulations are tested in accordance with the open-beaker gel test, i.e. the liquid detergent formulation is left in an uncovered beaker and is observed for gel formulation, detergents and do not gel after exposure to the atmosphere for 18 hours and are readily dispersible in water. However,- formulations (G), (H), (I) and (J) all containing higher molecular non-ionic detergents gel within 5- minutes subsequent to exposure to the atmosphere and as gelled are not easily dispersed in water. As ungelled detergents, however, all of the above formulations possess adequate cleaning and detersive characteristics when compared both to phosphate built detergents and ecology type commercial detergents.
' EXAMPLE 3 (A) 0.1:1 (D 0.75:1 (B) 0.251 (E) 1.25:1 c 0.511 (F) 1.5;1
When each of the above-noted samples is subjected to the open-beaker gel test, Samples (A) through (D) do not gel within 18 hours and are dispersed readily upon pouring into both hot and'cold water. Samples 3(E) and 15 (F), however, became gelled within minutes exposure to the atmosphere and are not readily dispersible in hot or cold water.
EXAMPLE 4 Examples 2(A) through (F) and (K) and (L) are repeated varying the total amount of non-ionic detergent from 40% to the following with a concomitant increase or decrease in total amount of water and alcohol:
(A) 20% (D) 45% (B) 25% (E) 50% (C) 30% (F) 60% Each of the above-noted detergent compositions cleaned quite well and possessed good detersive properties although those with a lower percentage of non-ionic detergents and those with lower and upper percentages did not clean quite as well as those wherein the amount of non-ionic materials was approximately 40%.
EXAMPLE 5 Examples 2(A) through (F), (K) and (L) are re peated except that the following anionic detergent materials are substituted for Neodol 25-3S:
(A) C ether sulfate containing 2 moles of condensed ethylene oxide (B) C ether sulfate containing 2 moles of condensed ethylene oxide (C) C ether sulfate containing 5 moles of condensed ethylene oxide (D) C ether sulfate containing 3 moles of condensed ethylene oxide (E) C ether sulfate containing 6 moles of condensed ethylene oxide.
Each of the above-noted detergent concentrations also possessed excellent detersive properties and was non-gelling upon standing when tested by the open-beaker gel test.
While the composition of the present invention has been illustrated by way of the foregoing specific examples, the composition of the present invention is to be in no way limited thereto but to be construed as broadly as any and all equivalents and as properly defined in the following appended claims.
What is claimed is:
1. A clear, non-gelling, heavy duty liquid detergent composition devoid of phosphate and nitrogenous builders and which consists essentially of:
(a) from 25 to 75% of a detergent mixture of at least one non-ionic detergent and an anionic detergent in a weight ratio ranging from :1 to 1:1, said nonionic detergent comprising from 100 to 50% by weight based on the weight of the non-ionic detergent of a (3 43 fatty alcohol ethoxylate containing from 6 to 11 moles of condensed ethylene oxide, with the proviso that the number of moles of condensed ethylene oxide is from to an of the average number of carbon atoms in the fatty alcohol and from 0 to 50% by weight of a C -C fatty alcohol ethoxylate containing from 10 to 14 moles of condensed ethylene oxide the number of moles of ethylene oxide being M to 1 times the number of carbon atoms in the fatty alcohol, said anionic detergent comprising a sulfated ethoxylated C -C fatty alcohol containing about 2 to 6 moles of condensed ethylene oxide;
(b) sufficient lower alkanol to solubilize the detergent mixture; and
(c) from 5 to 35% of water, said liquid detergent being substantially neutral in water.
2. The detergent composition of claim 1 wherein the ratio of total non-ionic to anionic is from 8:1 to 2:1.
3. The detergent composition of claim 1 wherein the amount of anionic is about A of the total amount of non-ionic.
4. The detergent composition of claim 1 wherein the fatty moiety of said sulfated alcohol contains from 12 to 15 carbon atoms.
5. The detergent composition of claim 4 wherein said fatty moiety comprises mixed alkyl containing from 12 to 15 carbon atoms and wherein at least 10% and not more than 50% of each member of said mixed alkyl is present.
6. The composition of claim 1 wherein the total nonionic detergent comprises 40% by weight of the composition and said anionic detergent comprises 10% by weight of the composition.
7. The composition of claim 1 wherein the non-ionic detergent comprises a mixed C1z-C15 fatty alcohol ethoxylate containing about 7 moles of condensed ethylene oxide.
8. The detergent composition of claim 1 wherein said lower alkanol comprises a C -C monohydric or polyhydric alcohol or mixtures thereof.
9. The detergent composition of claim 8 wherein said alkanol is a mixture based on total composition of 5 to 15 of polyhydric alcohol with the remainder being monohydric alcohol.
10. The detergent composition of claim 1 which further includes from about 0.5 to 5% of a bleach stable, at least partially water soluble fiourescent or optical brightener.
11. The detergent composition of claim 10 wherein said brightener comprises cotton, polyamide and/or polyester brightener.
12. The detergent composition of claim 10 wherein said brightener comprises a mixture of A=4,4-bis[(4-anilino 6 methylamino S triazine- 2-yl)amino]-2,2'-stilbenedisulfonic acid, disodium salt,
B=4,4' bis[(4 anilino 6 [bis(2 hydroxy-ethyl) amino] S triazine 2 yl)amino] 2,2 stilbenedisulfonic acid, disodium salt.
C=4-naphthotriazolyl-Z-stilbenesulfonic acid, sodium salt, and
D=2-(1,3-isoindazole) 2 (naphth[l,2-d]oxazole) stilbene.
13. The detergent composition of claim 11 wherein from 51 to 90% of said brightener is cotton brightener.
14. The detergent composition of claim 1 including from about 0.2 to 3% of aminopolycarboxylic acid or hydroxy carboxylic acid sequestering agent.
15. The detergent composition of claim 1 containing an alkaline material selected from the group consisting of mono-, diand trialkanolamines, alkylamines, ammonium and alkali hydroxides.
16. The detergent composition of claim 15 wherein said alkaline material comprises triethanolamine.
17. A process of laundering which comprises contacting cloth or fabric with aqueous media containing from 0.7 to 1.5 g./l. of the composition of claim 1, said containing being carried out at a temperature of from about 10 to C.
References Cited UNITED STATES PATENTS 2,920,045 1/ 1960 Hearn et al. 252Dig. 14 2,943,058 6/ 1960 Cook 252Dig. 14 3,179,599 4/ 1965 Eaton et al 252Dig. 14- 3,231,504 1/ 1966 Marion et al 252551 3,562,170 2/1971 Zorayan et a1 252551 FOREIGN PATENTS 836,774 6/ 1960 Great Britain 252Dig. 14
WILLIAM E. SCHULZ, Primary Examiner US. Cl. X.R. 252551, Dig. 1