United States Patent Of ice CONTROLLED sunsmo HEAVY DUTY LIQUID DETERGENT Vincent Lamberti, Hackensaclr, and Arthur 0. Gray, Jr.,
River Edge, N. J., assignors to Lever Brothers Company, New York, N. Y., a corporation of Maine No Drawing. Application July 25, 1957 Serial No. 674,048
4 Claims. (Cl. 252-137) The present invention relates to detergent compositions, and more particularly to controlled sudsing heavy duty liquid detergent compositions which have phase stability on storage.
Many detergent compositions have heretofore been prepared, but they have primarily been in a powdered form and thereby have many disadvantages enumerated below. Powdered detergent compositions are generally prepared by spray drying or drum drying, which are costly operations. When used in washing, the powdered detergent compositions must be dissolved to form dilute aqueous washing solutions. This step of dissolving or dispersing the powdered detergent compositions in the wash water is time consuming. Frequently, the powdered detergent compositions are difiicultly dispersed, since they may tend to form lumps. Powdered detergent compositions, moreover, tend to vary greatly in density unless particular care is taken in their preparation. Such a variation in density makes it difiicult to determine the exact amount thereof to be employed during washing. In addition, powdered detergent compositions may be difficult to dispense, since they sometimes clog the orifices of a dispenser. Also powdered detergent compositions have a tendency to cake at high humidities upon standing intheir own containers. Moreover, powdered detergent compositions, being normally sold in cardboard containers, are subject to spilling and waste in the event an open container is accidentally knocked over. Furthermore, their dustiness may be bothersome, particularly to persons who suffer from dust allergies.
All of. these disadvantages of powdered detergent compositions can be obviated by employing concentrated liquid detergent compositions. While light duty liquid detergent compositions have been prepared heretofore, they have proved to be suitable only for dishwashing and the cleaning of fine fabrics. Light duty, liquid detergent compositions are unsatisfactory for washing heavily soiled cotton fabrics, since such compositions have inadequate soil removal characteristics. Heavy dutyliquid detergent compositions, on the other hand, have excellent I soil removal characteristics and. are ideally suited for the,washing of heavily soiled cotton fabrics and other fabrics. v
A heavy duty liquid detergent must be homogeneous in composition at the time of addition to the washing machine in order to insure that the washing solution will contain the proper ratio of ingredients. The consumer buys a detergent product after it has been subjected to various temperatures and conditions of storage between the time of production and arrival on the dealers shelves. These various storage conditions have greater adverse eifect on a liquid product containing a delicately balanced active detergent and cellulosic suspension than on a detergent powder.
A heavy duty liquid detergent designed for use in both horizontal (front loading) and upright (top loading) washing machines must have acceptable sudsing and loading horizontal tumbler type automatic washers, these products foam profusely causing the tumbler to fill or overflow with dense suds. These dense suds impede the washing action by interfering with the free fall of clothes in the tumbler and may strain the working parts of the machine to cause slowing or stalling, further impeding washing action, and causing excessive wear of machine parts. When using high sudsers in this type of washer, the housewife is inclined to reduce usage level in order to eliminate this excess sudsing. The amount of product thus used is frequently insufficient to wash elfectively or to provide the desired level of optical brightener.
Profuse sudsing in top loading vertical agitator-type automatic washers does not interfere with washing action, but may tend to cause suds-lock during the extraction cycle. Suds-lock prevents efficient extraction of water from the clothes by slowing or stalling the machine, and also causes excessive wear of'machine parts.
A low-sudsing detergent product will produce no suds coverage when used in an upright washing machine. This lack of suds coverage does not obscure the dirty water from view and leads to the impression that too little product was used. The consumer may add more product in an attempt to obtain suds coverage. Such overuse of the product is uneconomical and may be reflected in failure of the consumer to repurchase.
Accordingly, it is an object of the present invention to provide heavy duty liquid detergent compositions which have controlled suds, i. e., there is neither a high amount nor a low amount of suds, but rather a medium amount of suds. It is a further object of the invention to provide heavy duty liquid detergent compositions in which the amount of suds produced therefrom is stable over a relatively prolonged period, especially in the presence of soil. It is also an object of the invention to provide heavy duty liquid detergent compositions which have phase stability, i. e., there is aminimum of separation of the various components therein upon storage.
The above objects have been accomplished by formulating heavy duty liquid detergent compositions having various critical factors which include the number of the components making up the compositions, the nature of the components present therein, and the amounts of the components utilized therein. The compositions of the invention consist essentially of aqueous suspensions of various components as further identified below.
The compositions contain as an active detergent component potassium dodecylbenzene sulfonate in an amount from about 2% to about 3%. The potassium dodecylbenzene sulfonate supplies a portion of the foaming and ponent which is used in an amount from about 22.5% to about 25% supplies the heavy duty detergent feature of the liquid and imparts good soil removal properties thereto.
The compositions also contain from about 2% to about 3% of an alkali metal xylene sulfonate, such as sodium xylene sulfonate or potassium xylene sulfonate.
Patented Nov. 11, 1958' Thexylene sulfonate acts as a hydrotrope in solubilizing the. active detergent components of thecompositions in the presence of a considerable amount of the polyphosphate and any other inorganic materials.
There is also present in the compostions about. 1%
of coconut oil fatty acids, i. e., the naturally occurring mixtureof. fatty acidspresent incoconut oil, as well as about 1% of the-condensation product of one moleof lauric monoethanolamide with one mole of'ethylene oxide, and about 1% of triethanolamine. These componentstogether aid in impartingphase stability and suds stability to the heavy duty liquid detergentcompositions.
The-compositions ofthe invention also contain a'pair of cellulosic'soil suspending agents which form a uniform, stable suspension therein even under adversev storage conditions Thispair ofcellulosic soil suspending agents consists of. about 0.3% 'offsodium carboxymethylceliulose and about 0.7% of Methocel. The sodium carboxymethylcellulose contains. 0.7 mole of carbox-ymethyl groups. peranhydroglucose unit. Methocel. is a trade namefor methylcel'lulose of. 25 centipoise viscosity in a acids, the condensation product of one mole of lauric monoethanolamide with one mole of ethylene oxide the triethanolamine, and any optical brighteners, and tetrapotassium pyrophosphate. The compositions are completed by the adjustment with alkali to a pH of about 12 followed by the addition of the alkali metal silicates.
The controlled sudsing heavy duty liquid detergent compositions of the invention having, phase stability on storage and suds stability on usagewill be further illustrated by the following examples.
The compositions of the invention were prepared'as were other compositions in which various components-of the compositions of the invention were omitted in order to demonstrate forcefully the criticality of the presence of the various components in thecompositions. These compositions are set forth below in Table I wherein Compositions X, X, and X" are the compositions of the invention containing various optional components, namely sodium silicate, potassium hydroxide; andi fluorescent dye, while Compositions A through F arezcomparative: compositions wherein various components ofthecompmsitions of the invention were omitted.
TABLE I Components Compositions (Percent by Weight) Fluorescent Dye (Uvitex SI) Fluorescent Dye (1:1 mixture of U Oaleofiuor White MR) i. Water, Miscellaneous Salts, and Potass m droxide to pH 11.8
2% aqueous dispersion having 27.5-32% methoxyl groups per cellulose molecule.
The remaining essential component of the heavy duty liquid detergent compositions is water which-servesas a solvent for the soluble components thereof.
If desired, .theheavy duty liquid detergent compositions may contain minorportions of an alkali, such as potassium hydroxide, to neutralize any excess acid impurities present in V the components of the compositions. -In addition, minor portionsof' compatible perfumes, fluorescent dyes, optical brighteners,.alkali metal silicates, and other desirable adjuvants may be added to the compositions. When a water-soluble alkali metal silicate is added to the compositions, the pH thereof must be adjusted to about 12. by the addition of free alkali, such as potassium hydroxide, to keepthe silicate in solution. TypicaLalkali metal. silicates include the-sodium or potassium silicates having the. following alkali to silica ratios: 1:3.92, 1:3.44, 1:3.25, 1:2.5, 1:2.4, 1:2.0, 1:1.8, and 1:1. Generally, about 3% of the alkali metal silicate is employed. The amount of perfumes, fluorescent dyes, and optical brighteners, is'quitesmall and generally is about 0.1% or less.
The controlled sudsing heavy duty liquid detergent compositions of. the invention may be prepared bymixing the components thereof together in the aqueous medium. Heat. maybe-conveniently utilized during the mixing of the components toincrease the rate of dissolution thereof. A preferred methodfor the preparation of the compositions isthe addition of the pair of cellulosic soil suspending agents to hot water followed by cooling to form an aqueous suspension thereof and the addition to the cellulosic suspension of an aqueous solution of the potassium-dodecylbenzene sulfonate, the alkali metal xylene sulfonate, the sodium tallow methyl taurate, the coconut oil fatty Compositions X, X, and X" of the invention asgwelL as various comparative compositions were testedfor phase stability under various conditions of storage. Alb
of the formulations were stored for seven days :atvarious.
storagetemperatures, namely 14 F., 35 F., roon1 tem-. In addition, samples;-
perature (70 F.), and F. of the formulations were subjected from 14 to five daily cyclings F. to room temperature and from 35 F. to:
room temperature. After undergoing storage the samples were either unaffected, showed a rise or drop of cellulosics, or an uneven cellulosic distribution, or. exhibited organic. phase separation. In order to facilitate comparison of various formulations the following numerical rating system was used:
Condition of sample after storage: 1 Numerical rates In the above numerical rating system rise or drop refersto the rise or drop of the cellulosic soil suspending agents. In any combination of conditions, the numerical rating. numbers are additive, i. e., very slight. drop plus uneven cellulosics equals 0.1plus 0.5, or a total rating of 0.6. However, the maximum numerical rating in any one condition will be 6.0. The numerical rating for each of the tests conducted Were added to give a total rating. Of
stability. Moreover, the presence of tetrapotassium pyrophosphate is quite critical, since the substitution of pentapotassium tripolyphosphate therefor produces compositions in which the cellulosic soilsuspending agents course, the lower the total rating, the better is the phase 5 are unstable and may cause the precipitation of silica stability of the composition. t from the compositions due to hydrolysis of this poly- Data on this phase stability test wherein Compositions phosphate. X, X, and X of the invention were compared with Com- The suds stabllity of the controlled sudsmg heavy duty positions A through F as typical comparative composiliquid detergent composit ons of the invention was also tions are set forth below in Table II. 10 tested and compared with other formulations WhlCh TABLE II Phase stabi ity test conditions and ratings Cycled Room Total Compositions 14 F 35 F. Temper- 125 F. 35 F. to 14 F. to Rating ature Room Room Temper- Temperature ature .0 0.2 2 0 1.5 3.7 0.2 0.1 0.2 1.0 0 0.1 1.6 0.1 0.1 0.1 0.2 0.1 0.1 0.7 1 a. 6 0 6 0. a 36.0 4 4 5 0.2 5 5 23.2 3 0.5 0 0.1 0.2 1 4.3 I 3 0 1.5 2 1 a 10.5 5 0.5 1.5 0 1.5 5 13.5 1.5 0 0 0.5 0 0.2 2.2
From the data set forth above in Table II it will be omitted various components of the compositions to show noted that Compositions X, X, and X of the invention 30 the criticality of the components in the compositions of had lower total ratings, and hence better phase stability, the invention. In the suds stability tests, 0.25 gram of than did any of the comparative compositions with the the detergent compositions were each added separately exception of Composition X versus Composition F. to l00 ml. of Water 1n 500 m1 glass stopped graduated Composition F, however, does not have the requisite cylinders. Each cyhnder was lnvertedt wenty nrnes suds stability in water containing soil as shown below 35 cycles from upright to uprlght) Initial suds volume in Table III and hence it does not have the balanced and suds volume at minute intervals for 45 minutes properties ofboth phase stabilityand suds stability that were recorded. Tests were run in distilled water at 120" are possessed by Compositions X, X, and X" f th F. Since the compositions of vtheinvention would norinvention, mally be used in automatic washers in which the water When various other components of the compositions 40 would Contall} Soil, one p 0f oil was fiof the invention were omitted therefrom, unstable com- The f01'mll1at10nS tested Composltlon X of the positions were also obtained. The phase stability test V li a W as COmP IH HS A through F Set forth was also run for compositions containing both less and above 111 Table data 011 11115 Suds stablllty test more of the tetrapotassium pyrophosphates, i. e., are Set forth below 111 Table 1 and thereof, and more and less of the detergent TABLEIH actives, i. e., potassium dodecylbenzene sulfonate and sodium tallow methyl taurate. These phase stability tests Suds Volume of Compositions (milliliters) showed that such heavy duty llquid detergent composi- Time Interval tions were unstable and accordingly demonstrate the (minutes) X A B C D E F criticality as to the amount of these components which must be employed therem' 250 220 200 210 160 125 210 Not only are the total number of components present 240 180 180 190 110 115 180 in the compositions critical as well as the amounts theregig g2 g3 28 of, but also the nature of the components is quite critical.
Thus, various anionic and nonionic synthetic organic non-soap detergents were substituted for an equal amount of the sodium tallow methyl taurate component of the compositions and phase stability tests run thereon. When each of the following exemplary synthetic detergents was so substituted, the resulting formulations were unstable as determined by the above phase stability test: potassium pentadecylbenzene sulfonate, Santomerse E (a mixture of potassium pentylbenzene sulfonate and potassium hexylbenzene sulfonate), sodium lauryl sulfate, sodium N-ethyl-N-palmitoyl taurate, sodium N-isopropyl-N-hexadecanoyl taurate, sodium N-methyl-N-oleyl taurate, the condensate of dodecyl phenol with 13 moles of ethylene oxide, the condensate of propylene oxide with ethylene oxide, sodium isopropyl naphthalene sulfonate, disodiurn N-octadecyl sulfosuccinate, potassium a-sulfopalmitate.
The presence of sodium Xylene sulfonate in the controlled sudsing heavy duty liquid detergent compositions of the invention is quite critical, since the substitution therefor of sodium toluene sulfonate or sodium benzene sulfonate' produced formulations having poor phase The data set forth in Table III above clearly show that representative Composition X of the invention had far greater suds stability than did Compositions A through F in view of the small comparative decrease in sudsvolume over a 45 minute interval. It will be appreciated that the compositions of the invention are concerned with a system of suds which are controlled to a lower level than is desired for non-automatic washers, so that the importance of the data set forth above in Table III lies not in a comparison of the total suds volume, but rather in a comparison of the suds stability or change in suds volume over a period of time.
The controlled nature of the suds produced by the compositions of the invention is evident from the following data in Table IV below wherein 2.6 ounces of Compositions X, X, and X were separately added to 8 gallons of water containing soil and the height of suds on the port of a horizontal or front loading Bendix Washer observed at 3, 6, 9 and 12 minutes during the washing cycle. In this table the fractions refer to the portion of the port coveredby the suds.
7 TABLE Iv Suds Volume Compositions a a as 1A Vi it a as 1 When highsudsing' detergents were Similarly tested, they produced a profuse amount of suds at the end of only three minutes which completely covered the port of the washer.
In view of the above data it will be apparent that the heavy duty liquid detergent compositions which have phase stability on storage and suds stability in usage and thereby make them products ideally suited for use in automatic clothes washers. sudsing products do not produce excess suds when used in horizontal washing machines, but they do give a;showing of suds on the water surface when used in vertical type machines.
It will be appreciated that various modifications andv changes may be made in the compositions of the invention without departing from the spirit thereof and accordingly the invention is to be limited only within the scope ofthe appended: claims.
We claim:
- 1. A controlled. sudsingyheavy duty liquid detergent composition which has phase stability. on storage and suds stability-in usage consisting essentially of. an aqueous suspension of: from' about2% to about 3% ofpotassium dodecylbenz'ene sulfonate, abo.uti5% of sodium-tallow methyl taurate, from about 2%" to about 3% offanjalkali metal. xylene sulfonate,
about 1% of ,coconutoil' fatty acids, about 1% of the Moreover, the controlled from about 3.5% to 35 l compositions of the mvention provide for the first t1me m0 6 of ethylene Oxide about 1% condensation product of one mole of lauric monoethanolamide with one mole of ethylene oxide, about 1% of triethanolamine, about 0.3% of sodium carboxymethylcellulose, about 0.7% ofmethylcellulose, and from about 22.5% to. about'25% of tetrapotassium pyrophosphate.
2. A controlled sudsing heavy duty liquid detergent composition which has phase stability on storage and suds stability in usage consisting essentially of an aqueous suspension of about 2% of potassium dodecylbenzene sulfonate, about 3.5% of sodium tallow methyl taurate, about 2% of sodiumxylene'sulfonate, about 1% of coco nutnoilfatty. acids, about. 1% of the condensation prodnot of one mole of lauric monoethanolamide with one of triethanolamine, about 0.3% of sodium carboxymethylcellulose having 0.7 mole of carboxymethyl groups per anhydroglucose unit, about 0.7% of methylcellulose of 25 centipoise I viscosityin a 2% aqueous dispersion having 27.5-32% methoxyl groups'per cellulose molecule, and about 25% of tetrapotassium pyrophosphate.
3. A composition as set forth in claim 2 containing about 3% of an alkali metal silicate and having a pH of about 12.
4. A composition as set forth in claim 2 having a pH of about 12.
References Cited in the file of this patent UNITED STATES PATENTS Re. 23,840 Vitale June 15, 1954 2,002,613 Orthner May 28, 1935 2,581,677 Machlis Jan. 8, 1952 2,618,607 Sanders Nov. 18, 1952 FOREIGN PATENTS 678,445 Great Britain -n Sept. 3, 1952