US3341459A - Detergent compositions - Google Patents

Description

United States Patent Office 3,341,459 Patented Sept. 12, 1967 3,341,459 DETERGENT COMPOSITIONS Jerry Edison Davis, Cincinnati, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio N Drawing. Filed May 25, 1964, Ser. No. 370,036 Claims. (Cl. 252--137) This invention relates to detergent compositions especially effective in cool water. The term cool water as used in describing this invention is intended to mean aqueous washing solutions having a temperature within a range of from about 40 F. to about 100 F This temperature characterization more generally is intended to mean temperatures substantially below those which are commonly associated with the usual household parlance of hot water.

Some garments or fabrics cannot be washed in hot water, i.e., say in excess of about 110 F., without running the risk of damaging the material by shrinkage or altering the handle or feel of the fabric. For such laundering situations fabric and material manufacturers recommend the use of cool water. Conventional detergents, however, are known to be less effective as cleaning agents, i.e., removing soil, in cool aqueous solutions. There is no question that the presently available detergent compositions can be used under such circumstances but with varying degrees of successful cleaning results. To compensate for the poorer cleaning performance, consumers are generally inclined to use excessive amounts of the detergent compositions. Such economic waste is unfortunate but has been necessary prior to the present invention due to the lack of detergent compositions which are specially formulated to be effective cleaning agents in cool water.

It is a primary object of this invention to provide a detergent composition which is especially effective in cleaning soiled fabrics in cool aqueous washing solutions. Another object of the present invention is to provide novel built detergent compositions consisting essentially of an alkyl polyethoxy amine oxide detergent compound having the general formula:

. R wherein R is an alkyl radical containing from about to about 18 carbon atoms. R and R are each methyl, ethyl or ethanol, and n averages from 2 to 10; and a builder material selected from the group consisting of water soluble inorganic alkaline builder salts, organic alkaline sequestrant builder salts and mixtures thereof, the ratio of weight of the detergent to the builder in the range of from about 4:1 to 1:20. Other objects will be readily apparent to those skilled in the .art from a review of the following detailed description of the present invention.

It has now been surprisingly discovered that certain alkyl polyethoxy amine oxide compounds having the formula set forth above possess unusually effective cleaning .power in aqueous solutions having the cool temperatures defined above. These unexpected cleaning properties of the compounds of this invention are demonstrated by the experimental data presented below. Of the alkyl polyethoxy amine oxides described herein, best cool water cleaning results are obtained when R is dodecyl or tetradecyl, R and R are each methyl and n averages about 3.

The alkyl polyethoxy amine oxide compounds to which the present invention pertains can be prepared according to any convenient process. The alkyl can be derived from synthetic sources such as synthetic dodecanol or from natural sources such as coconut oil or tal'low from which fatty alcohols are made. Such processes are illustrated hereinafter but other methods can be used.

Alkyl polyethoxy amine oxide compounds can be prepared by oxidizing, with a strong oxidizing agent such as hydrogen peroxide, the corresponding alkyl polyethoxy amine. This .amine in turn can be prepared by reacting a polyethoxylated alcohol or a polyethoxylated alcohol sulfate with an appropriate secondary amine such as dimethylamine, diethylamine, or diethanolamine. Preferably, a neutralized, sulfate polyethoxylated alcohol is used in the reaction with the secondary amine. Polyethoxylated alcohols are known and can be formed either by reacting fatty alcohol with 2 to 10 moles of ethylene oxide or by reacting alkyl bromides with sodium glycolate in excess diethylene glycol or triethylene glycol. The former reaction results not in a uniform product, but a mixture of alcohol ethers containing varying molar amounts of ethylene oxide wherein the average molar amount of ethylene oxide per ether corresponds to the moles of ethylene oxide reacted with the alcohol. In the latter reaction a uniform product does result; for example, if diethylene glycol is used, the reaction product is substantially all diethoxylated alcohol. As used herein, the term alkyl polyethoxy amine oxide includes a single compound containing polyethoxy ether linkages or a mixture of such compounds where the average molar proportion of ethylene oxide is noted.

A preferred alkyl polyethoxy amine oxide was prepared as follows: 2.9 pounds of the sodium salt of the sulfated reaction product of coconut fatty alcohols and three moles of ethylene oxide was reacted in 6 pounds of water with dimethylamine, in a molar proportion of dimethylamine to the sulfated reaction product of 10:1, in an autoclave at 350 F. and 425 p.s.i. pressure for two hours. The coconut fatty alcohol comprised about 2% decanol, 66% dodecanol, 23% tetradecanol and 9% hexadecanol. The resulting reaction mixture separated into two phases. The aqueous upper phase contained the alkyl polyethoxy amine in a yield about 96.5% of theoretical; the upper phase was separated and water was removed from it with vacuum. Fifty grams of the resulting dimethyl coconut alkyl polyethoxy amine was oxidized to the amine oxide with 220 grams of 30% aqueous hydrogen peroxide.

While the class of alkyl polyethoxy amine oxide compounds just described can be employed alone as cool water detergent compounds on easily cleanablematerials, more outstanding performances are obtained when they are mixed with other ingredients which enhance or build the cleaning powder of detergent compounds, i.e., socalled builder or booster compounds. Such built or heavyduty detergency is essential with hard-to-clean fabrics such as cotton. According to the present invention, therefore, the alkyl polyethoxy amine oxide detergent compounds are preferably used in conjunction with such other ingredients which substantially improve cleaning power. While the term builder is used herein. in its singular form, the term is intended to cover mixtures of such compounds also. i

The present invention pertains to detergent compositions consisting essentially of a water soluble inorganic alkaline builder salt or a water soluble organic alkaline sequestrant builder salt, or mixtures thereof, and a member of the class of alkyl polyethoxy amine oxide detergent compounds having the general formula described above, which composition consists essentially of the detergent compounds and a builder material in a ratio by weight of detergent to builder of about 4:1 to about 1:20. The preferred ratio of the detergent to builder is 1:1 to about 1:10. The ratios and percentages referred to herein are all by weight unless otherwise noted.

The built detergent compositions of this invention can be prepared as granular, tablet, or liquid compositions and perform effectively. Within the above detergent to builder ratio range, granular and tablet compositions offering outstanding cool water washing performance can contain from 4% to 50% by weight of the alkyl polyethoxy amine oxide detergent compound, the balance comprising essentially a selected builder material or mixtures of builders and any optional ingredients employed. Preferred granular and tablet compositions contain from about 15% to about 35% by weight of the alkyl polyethoxy amine oxide detergent with the balance comprising the essential builder materials and other ingredients. On the other hand, built liquid detergents prepared according to the present invention have a slightly modified composition to compensate for the requirement of a liquid vehicle. Such liquid compositions can contain from about 2% to 25% by weight of the alkyl polyethoxy amine oxide detergent, preferably from about 8% to about 18%, with the remainder comprised essentially of builder ingredients, and, of course, a liquid vehicle as described below. The ratio set forth above between the detergent and builder applies equally to all physical forms of the composition.

Water soluble inorganic alkaline builder salts which can be used in this invention alone or in admixture are alkali metal carbonates, borates, phosphates, polyphosphates, bicarbonates and silicates. Ammonium or substituted ammonium, e.g., triethanol ammonium, salts of these materials can also be used. Specific examples of suitable salts are sodium tripolyphosphate, sodium carbonate, sodium tetraborate, sodium and potassium pyrophosphate, sodium and ammonium bicarbonate, potassium tripolyphosphate, sodium hexametaphosphate, sodium sesquicarbonate, sodium orthophosphate and potassium bicarbonate. The preferred inorganic alkaline builders according to this invention are alkali metal tripolyphosphates for built granular and tablet compositions and alkali metal pyrophosphates for built liquid compositions. Potassium is the preferred alkali metal used in liquid compositions and sodium finds best application for granular or tablet compositions.

Examples of suitable organic alkaline sequestrant builder salts used in this invention alone or in admixture are alkali metal, ammonium or substituted ammonium, aminocarboxylates, e.g., sodium and potassium ethylenediaminetetraacetate, sodium and potassium N-(2-hydroxyethyl)-ethylenediaminetriacetates, sodium and potassium nitrilotriacetates and sodium, potassium and triethanolammonium N (2 -hydroxyethyl)-nitrilodiacetates. Mixed salts of these polycarboxylates are also suitable. The alkali metal salts of phytic acid, e.g., sodium phytate are also suitable as organic alkaline sequestrant builder salts (see US. Patent 2,739,942). Ethane-l-hydroxy, l-diphosphonate as described in copending patent application Ser. No. 187,327, filed Apr. 15, 1962, can also be used as a builder, either alone or in mixtures with other builder compounds. Other suitable builders include methylene and ethylene diphosphonates and their derivatives.

Besides the builders being used in the form of mixtures it is also possible according to the present invention to use the alkyl polyethoxy amine oxide compounds of this invention in combination with other cleaning agents such as anionic, nonionic and zwitterionic organic detergent surfactant compounds. When it is desired to use the alkyl polyethoxy amine oxide compounds in combination with other detergent compounds, the ratio of the amine oxide to such other detergent compound is about 10:1 to 1:5. If for any reason, it is desired to use an alkyl polyethoxy amine oxide in admixture with another detergent compound as the active portion of a cleaning composition, the ratio of such a mixture to the builder salt should be within the previously prescribed range of 4:1 to 1:20. A composition prepared along these lines can contain from 4% to 50% of such a mixture and 5% to 85% of a builder salt selected from water soluble inorganic alkaline builder salts, water soluble organic sequestrant builder salts, and mixtures thereof, and observing this ratio range.

Examples of anionic soap detergents which can be used in admixture with the alkyl polyethoxy amine oxide, if desired, are the sodium, potassium, ammonium and alkylolammonium salts of higher detergent range fatty acids (C -C Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium or potassium tallow and coconut soap. Examples of suitable anionic organic nonsoap detergents are: alkylglycerylethersulfonates; alkyl sulfates; alkyl monoglyceride sulfates or sulfonates; alkylpolyethenoxy ether sulfates; acylsarcosinates; acyl esters of isethionates; N-acyl-N-methyl taurides, alkylbenzenesulfonates wherein the alkyl substituent is straight chain or branched chain; sulfonated a olefins alkylphenol polyethenoxy sulfonates. In these compounds the alkyl and acyl groups, respectively, contain 10 to 20 carbon atoms. They are used in the form of water soluble salts, the sodium, potassium, ammonium, and alkylolammonium salts, for example. Specific example are: sodium lauryl sulfate, potassium N-methyl-N-lauroyl tauride; triethanolammonium dodecylbenzene sulfonate.

Examples of nonionic organic detergents which can be used in the compositions of this invention, if desired, are: polyethylene oxide condensates of alkylphenols wherein the alkyl group contains from 8 to 15 carbon atoms (e.g., t-octylphenol) and the ethylene oxide is present in a molar ratio of ethylene oxide to alkylphenol in the range of 8:1 to 20:1; condensation products of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine wherein the molecular weight of the condensation products ranges from 5000 to 11,000; the condensation products of from about 5 to 30 moles of ethylene oxide with one mole of a straight or branched chain aliphatic alcohol containing from 8 to 18 carbon atoms, e.g., lauryl alcohol; higher alkyl dilower alkyl amine or phosphine oxides, e.g., dodecyldimethylamine oxide or dodecyldimethyl phosphine oxide; alkyl methyl sulfoxides such as dodecyl methyl sulfoxide.

Zwitterionic synthetic detergent surfactant compounds which can be used are broadly described as derivatives of aliphatic quaternary ammonium compounds, in which the aliphatic radical can be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one contains an anionic water solubilization group, e.g., carboxy, sulfo, or sulfato. Examples of compounds falling within this definition are: 3 (N,N-dimethyl-N-hexadecylammonia)- 2-hydroxypropane-l-sulfonate and the corresponding dodecyl and tetradecyl homologs and 3-(N,N-dimethyl-N- dodecylammonio) propane l-sulfonate and the corresponding hexadecyl and tetradecyl homologs.

The discovery that the compositions containing members of the class of compounds described in this invention show exceptional cool water detergency was unpredictable in view of the fact that there is, as yet, virtually no generally accepted theory or background information on the mechanics of cool water detergency. Moreover, cleaning agents such as sodium tallow alcohol sulfate or sodium dodecylbenzenesulfonate, for example, which are good hot water (-140 F.) detergent compounds exhibit a minimum of cleaning activity in cool water. One would be led to assume that the alkyl polyethoxy amine oxide compounds of the present invention should be, comparatively speaking, as poor as any other conventional detergent compounds when used in cool water; certainly there is no reason to expect that they would behave otherwise. As has been discovered, however, the compositions containing the alkyl polyethoxy amine oxide compounds of this invention are substantially more effective in cool water than some of the commonly used commercially available detergent compositions are in hot water. It can, therefore, be seen that the structure of a given detergent compound which is effective in hot water has little or no discernible relation to the effectiveness of such compounds in cool water.

It has also been found that maximum cleaning occurs with the compositions of this invention when the pH of the washing solution, at cool water temperatures as herein defined is within the range of from about 8 to about 12 with the preferred pH range being 9.5 to 11.5. Using normal amounts of water for washing, the desired pH of the solution can be obtained by incorporating into the compositions of this invention a normal amount of a strongly alkaline material such as sodium silicate, i.e., up to about 10% by weight. The silicate acts as a buifer and also as a corrosion inhibitor.

A laundering method incorporating the discovery of the present invention can be practiced in a number of different ways. Preferably the washing step is followed by rinsing and drying the fabrics. The washing solution can be prepared by adding the granular, tablet or liquid detergent composition prepared according to this invention to any container which contains cool water at a temperature ranging from about 40 F. to about 100 F., usually about 80 F. The detergent composition concentration in solution can range from about to .50% by total weight, and should be added in sufficient amount to provide a concentration of at least 0.005% of the alkyl polyethoxy amine oxide detergent compound. The fabrics can be added to the container or washer before or after the washing solution is added. As is usual in a washing step, the fabrics are then agitated in the detergent solution. While the period of time may vary, an automatic agitator type washer, generally employs a washing cycle which ranges from 8 to 15 minutes.

After the washing step, the washing liquor is drained off or the fabrics are separated from the liquor and thereafter the fabrics are rinsed in clean water. The fabrics can be rinsed as many times as desired in order to insure that washing liquor is removed. Using an automatic washer, it has been found that about four spray rinses and one deep rinse are usually sufficient for this purpose. Between and after rinsing steps, the bulk of the rinse water .is usually drawn from, or spun out of the fabrics. After rinsing, the fabrics are dried. Although rinsing and drying are usual and desirable steps, the important advantage of the invention is achieved in the washing step.

The surprisingly efiective cool water performance characteristics of the alkyl polyethoxy amine oxide compounds described herein are demonstrated by conducting the following tests.

Naturally soiled fabric swatches (desized cotton print cloth) were washed for ten minutes in an aqueous solution of a detergent composition having a pH of and containing 7 grains equivalent CaCO per gallon hardness. Detergent compositions were prepared containing only basic essentials, i.e., a detergent compound and a builder compound. The detergent compounds were respectively (1) a representative alkylpolyethoxy amine oxide, i.e., the coconut alkyl dimethyl polyethoxy amine oxide containing an average of 3 moles of ethylene oxide described above; and (2) sodium tetrapropylenebenzene sulfonate (ABS); the builder compound in each composition was sodium tripolyphosphate. By using the same builder compound in each composition, any variations in cleaning performance could be directly attributed to the specific detergent being evaluated. The concentration by weight in the washing solution of the detergent compound was 03%; the concentration of the builder was .06%.

These two compositions were compared for their soil removal properties, the alkyl polyethoxy amine oxide in a washing solution at 80 F. and the ABS in a washing solution at 140 F. Soil removal, expressed as a percentage of the soil originally present on the soiled swatches, was 70% for the alkyl polyethoxy amine oxide and 64% for the ABS. The amounts of soil present (a) on the cloth swatches after washing and drying and (b) on similar unwashed swatches were determined by solvent extraction.

The alkyl polyethoxy amine oxide detergent compound gave results in water at F. which were superior to the results obtained with a formula wherein sodium tetrapropylenebenzenesulfonate (ABS) was used as a cleaning agent in a washing solution having a temperature of 140 F. Sodium tetrapropylenebenzenesulfonate is widely regarded as a standard for comparison. Compositions which perform better than ABS at 140 F. generally can find application and commercial acceptance as detergent formulations. In situations such as the present invention where superior cleaning is obtained with different compounds at low temperatures, i.e., 80 F.. the results are even more remarkable.

The same superiority of the alkyl polyethoxy amine oxide compound at 80 F. over ABS at 140 F. was demonstrated in a similar washing test employing soiled mens white dress shirts where the collars and cuffs were used as the basis for comparing cleaning ability of compositions employing these two detergent compounds. The superior cleaning ability of the alkyl polyethoxy amine oxide was particularly manifested in the whiteness of the collars and cuffs.

Substantially the same performance advantages are observed by the housewife when doing the home laundry in water ranging from 40 to 100 F. Woolens and syn thetic fibers washed in the same manner are cleaned as eificiently when washed according to the process of this invention and using the compositions of this invention as they would be if they were washed in conventional detergent compositions at hot water temperatures, yet a minimum of shrinkage and wrinkling takes place and the feel of the wool is preserved to a greater extent.

While the compositions of this invention are outstandingly eifective in water at a temperature ranging from 40 F. to 100 F. the preferred temperature range is about 60 F. to F. Below about 60 F. it has been found that the granular detergent compositions of this invention are somewhat slower to dissolve, consequently it is preferred to use liquid compositions at such lower temperatures.

The following composition-s further illustrate the manner in which the invention can be practiced; they provide improved cool Water detergency characteristics similar to that demonstrated in the soil removal comparison set forth above. The pHs of the compositions in aqueous solutions ranged from 9.5 to 11.5 at concentrations of about 0.25%. Included are both liquid and granular formulations. The examples are not to be construed as limiting the scope of the invention claimed hereinafter. These compositions are useful in automatic washers and conventional type washers employing cool water, 40 F. to F., as well as hand washing operations.

EXAMPLE I Solidgranules Percent Dimethyl dodecyl polyethoxy amine oxide containing an average of three moles of ethylene oxide 17.5

Sodium tripolyphosphate 50.0

Sodium silicate (Na O:SiO =1:2.5) 10.0

Sodium sulfate 17.5

Moisture 5.0 EXAMPLE II Compressed granules-tablet Diethyl tetradecyl polyethoxy a-mine oxide containing an average of five moles of ethylene oxide 31 Sodium tripolyphosphate 52 Trisodium phosphate 10 Moisture 7 7 EXAMPLE 1v Solid-granul s oxide 25 Sodium tripolyphosphate 35 Sodium carbonate 10 Sodium silicate (Na O:SiO =1:2.5) 5 Moisture 5 EXAMPLE V Salim-granules Dimethyl decyl polyethoxy amine oxide containing an average of two moles of ethylene oxide Diethanol tetradecyl polyethoxy amine oxide containing an average of four moles of ethylene oxide 10 Sodium tallow alcohol sulfate 10 Ethane-l-hydroxy-l,l-diphosphonate 20 Sodium tripolyphosphate 10 Sodium nitrilotriacetate 10 Sodium sulfate 8 Sodium silicate (Na O:SiO =1:2.5) 11 Moisture 11 EXAMPLE VI Liquid 3-(N,N dimethyl-N-dodecyl ammonio)-2-hydroxy propanel-sulfona-te Dimethyl dodecyl polyethoxy amine oxide containing three moles of ethylene oxide 10.0 Tetrapotassium pyrophosphate 19.0 Sodium silicate (Na O:SiO =1:1.6) 3.8 Potassium toluene sulfonate 8.5 Carboxymethyl hydroxyethyl cellulose .3 Water Balance EXAMPLE VII Liquid Dimethyl dodecyl polyethoxy amine oxide containtainin-g two moles of ethylene oxide 6.0 Sodium dodecyl benzene sulfonate 6.0

Tetrapotassium pyrophosphate 20.0

Sodium silicate (Na O:SiO =1:1.6 3.8 Potassium toluene sulfonate 8.5 Carboxymethyl hydroxymethyl cellulose .3 Water Balance EXAMPLE VIII Solid-granules Dimethyl tetradecyl polyethoxy amine oxide containthree moles of ethylene oxide 15 Condensation production of 10 moles of ethylene oxide and one mole of tallow fatty alcohol 5 Dodecyl methyl sulfoxide 5 Percent Coconut oil soap 5 Sodium tripolyphosphate 50 Sodium ethylene diamine tetraacetate 20 It will be appreciated that the alkyl polyethoxy amine oxide compounds used in the present invention can be incorporated into many other liquid or granular detergent compositions with suitable adjustments being made in the other components.

Materials which are considered normal and desirable additives in liquid or granule detergent compositions can be added to the compositions of this invention without adversely affecting or modifying basic cleaning characteristics. For example, a tarnish inhibitor such as benzotriazole or ethylene thiourea may be added in amounts up to about 1%. Fluorescers, perfume, bleaching agents, color, antiredeposition agents, antibacterial agents, thickening agents, opacifiers, and blending or viscosity control agents, while not essential in the compositions of this invention, may also be added.

While the present invention finds exceptional application in cool water washing situations, the compositions described herein can also be used in conjunction with warm and hot water.

What is claimed herein is:

1. A detergent composition consisting essentially of an amine oxide in the following general formula wherein R is an alkyl radical containing from 12 to 14 carbon atoms, R and R are each methyl, and n averages 3, and sodium tripolyphosphate, the ratio by weight of said amine oxide to said tripolyphosphate being in the range of about 4:1 to about 1:20.

2. The detergent composition of claim 1 wherein the ratio of said detergent compound to said builder is from 1:1 to about 1:10, by weight.

3. The detergent composition of claim 1 in which the aqueous solution has a pH of from about 8,to about 12.

4. The detergent composition of claim 3 wherein the preferred pH range is between 9.5 and 11.5.

5. A laundering process comprising the steps of immersing soiled fabrics and garments into an aqueous solution having a temperature within the range of from F. to F., and a pH of from about 8 to about 12, said aqueous solution containing from about 05% to 50% by total weight of the detergent composition of claim 1.

References Cited UNITED STATES PATENTS 3,202,714 8/1965 Zimmerer et al. 252137 X 3,206,512 9/1965 Koebner et al 252-152 X 3,235,506 2/1966 Diehl et al. 252-152 X LEON D. ROSDOL, Primary Examiner.

S. E. DARDEN, Assistant Examiner,

Claims (2)

1. A DETERGENT COMPOSITION ESSENTIALLY OF AN AMINE OXIDE IN THE FOLLOWING GENERAL FORMULA

5. A LAUNDERING PROCESS COMPRISING THE STEPS OF IMMERSING SOILED FABRICS AND GARMENTS INTO AN AQUEOUS SOLUTION HAVING A TEMPERATURE WITHIN THE RANGE OF FROM 60* F. TO 90*F., AND A PH OF FROM ABOUT 8 TO ABOUT 12, SAID AQUEOUS SOLUTION CONTAINING FROM ABOUT .05% TO .50% BY TOTAL WEIGHT OF THE DETERGENT COMPOSITION OF CLAIM 1.