US2877186A - Liquid detergent composition - Google Patents

Abstract

A single-phase liquid detergent composition comprises (a) 6-14% by weight of one or more alkali-metal alkyl glyceryl ether sulphonates in which the alkyl radical is at least 50% derived from alcohols of 10-14 carbon atoms, (b) 12% to the solubility limit of potassium pyro- or tripoly-phosphate or both, (c) 3.5-6% of sodium silicate solids with a SiO2:Na2O ratio of 1.6-2.6, (d) 2-6% of ethanol, isopropanol or diethylene glycol monobutyl ether, or mixtures thereof, (e) 3-8% of an anionic solubilizer, and (f) 40-73.5% of water. If desired, (e) may be omitted so that a twophase composition results in which case the amount of water (f) will be 40-76.5%. Component (a) is preferably a sodium or potassium salt in which the alkyl groups are derived from coconut or oxo alcohols; the sulphonate mixture usually includes a proportion of diglyceryl radicals. Component (e), if of straight chain configuration, is a phosphate containing 1-3 straight hydrocarbon chains, each having up to 5 carbon atoms; if of cyclic configuration, (e) is a sulphonate in which the hydrocarbon portion of the molecule contains either a benzene ring or an alkyl-substituted benzene group of up to 8 carbon atoms. Suitable solubilizers are triamyl phosphate and sodium benzene or xylene sulphonates, but sodium toluene sulphonate is preferred. Amorphous silica, bentonite-type clays, tarnish inhibitors, colouring material, perfume, and inorganic salts may also be incorporated. Specification 848,225 and U.S.A. Specification 2,618,607 are referred to.

Description

l Jnited States Patent William C. Krumrei, Procter & Gamble poration of Ohio No Drawing. Application June 29, 1956 Serial No. 594,676

7 Claims. (Cl. 252138) Springdale, Ohio, assignor to The Company, Cincinnati, Ohio, a cor- This invention is directed to the provisionv of liquid heavy duty detergent compositions and particularly compositions which contain large amounts of pyroor tripolyphosphate but which do not tarnish or corrode aluminum to an objectable degree.

The corrosion inhibitor most elfective in inhibiting corrosion of aluminum by alkaline phosphates is silicate of soda. In the compositions of the prior art, the addition of silicate of soda to an aqueous solution of the anionic synthetic detergents and an alkaline phosphate caused a separation, cloudiness or livering. This is described in U. S. Letters Patent 2,618,607, iss ued November 18, 1952, to Herbert L. Sanders.

Most anionic synthetic detergents are not, unassisted, completely soluble in aqueous phosphate solutions of a concentration of 20% or more, even in the absence of silicate. The anionics salt out, forming a gummy layer at the top of the solution. Completesolution of anionic synthetic detergent in such phosphate solutions can be achieved, however, with a solubilizer, usually a sodium salt of the sulfonates of benzene or methyl substituted benzene. If one adds silicate of soda, in amounts adequate to inhibit corrosion of aluminum during the use of the composition in cleansing operations, to those previously known phosphate solutions into which an anionic synthetic detergent has been thus solubilized, the silicate will not dissolve completely, but forms a gelatinous mass.

I have found that a specific anionic synthetic detergent in aqueous liquid heavy duty detergent formulations has the property of solubilizing silicate of soda in amounts adequate to inhibit corrosion by phosphates. The specific anionic synthetic detergent is a water soluble alkali metal salt of alkyl glyceryl ether sulfonate in which the alkyl radical is derived at least 50% from alcohols of to 14 carbon atoms.

These alkyl glyceryl ether sulfonates have an additional advantage, they inhibit the redeposition of soil, thus eliminating the need for sodium carboxymethyl cellulose. The carboxymethyl cellulose does not dissolve completely in aqueous detergent solutions thus imparting a murky look to the solution.

A typical composition embodying the discovery herein described will contain from about 6% to about 14% of alkali metal salts of alkyl glyceryl ether sulfonate, 12% to 27% of potassium pyrophosphate, or potassium tripolyphosphate, 2% to 6% of ethyl or isopropyl alcohol, or diethylene glycol monobutyl ether, 3.5% to' 6% of silicate of soda (solids basis) of SiOzNaO ratio of 1.6:1 to 26:1, 3.0% to 8% of a solubiliz'ing agent, and water'to make 100%. This produces a clear solution at room temperature, and remains clear down to about 50 F. I

The aforesaid salts of the alkyl glyceryl ether sulfonate are made by reacting fatty alcohol mixtures containing at least 50% of alcohols of 10 to 14 carbon atoms with epichlorohydrin and by reacting the'alkyl chloroglyceryl ethers so formed with sodium or potassium sulfites.

The alkyl glyceryl ether sulfonate used in the examples contains about 15% of diglyceryl ether sulfonates. This is only because of the ease of manufacturing this species. The invention may be carried out with alkyl glyceryl ether sulfonates, where the alkyl is at least 50% radicals of alcohols of 10 to 14 carbons, with only monoglyceryl radicals present or with up to about 30% of diglyceryl radicals present. The term alkyl glyceryl ether sulfonate as used herein means any and all of the alkyl glyceryl ether sulfonates from those containing no diglyceryl radicals to those containing up to 30% diglyceryl radicals.

Instead of the fatty alcohols used to prepare the alkyl glyceryl ether sulfonate there may be used the alcohols prepared by the oxo reaction from straight chain olefins. These should meet the same qualifications as to chain length as the fatty alcohols, that is, these should contain at least 50% of alcohols of 10 to 14 carbons.

A number of solubilizing agents are useful in efiecting complete solution of synthetic detergents in relatively concentrated electrolyte systems. Trialkyl phosphates, where the alkyl is of low molecular weight, such as triamyl phosphate, or other trialkyl phosphates where the sum of the carbons in the alkyl groups are not more than 15 are effective. The alkali metal salts of various organic sulfonates have been used for their solubilizing properties. Petroleum sulfonate salts, salts of benzene snlfonate and methyl substituted benzene sulfonate are among the best of these. The manner in which the anionics solubilize is presented in Schwartz and Perry,

"Surface Active Agents, page 307 et seq., Interscience Publishers, New York, 1949.

Generically speaking the solubilizers found useful in the present invention are anionic surface active materials, the molecules of which contain both a hydrophobic hydrocarbon portion and a hydrophilic portion. The hydrophobic hydrocarbon portion of the molecule, if of straight chain configuration, may contain from one to three separate alkyl groups each containing not more than 5 carbon atoms. phobic hydrocarbon portion of the molecule may contain only one alkyl-substituted or unsubstituted cylic group containing a total of not more than 8 carbon atoms. The hydrophilic portion of the molecule may be either the water-soluble salt of a sulfonic acid radical (sulfonate) or a phosphate. It is to be understood that wherever hereinafter and in the claims the term anionic solubilizer appears a material coming Within the scope of the above definition is intended.

The solubilizer I prefer is sodium toluene sulfonate. Sodium benzene sulfonate and sodium xylene sulfonate are also eifective but require slightly larger amounts to eifect blending. Example I and the explanation follow-j ing show the steps needed to completely blend the in gredients into a clear solution.

Example I The anionic used was alkyl glyceryl ether potassium sulfonate in which the alkyl was derived from middle If of cyclic configuration, the hydro 3 cut coconut alcohols containing 66% dodecanol. The epichlorohydrin used in making the chloroether was in the molar ratio of 1.15 to the fatty alcohol. This excess of epichlorohydrin will produce glyceryl chloroethers with about of the glyceryl chloroethers present as diglyceryl dichloroethers. This alkyl ether mixture was reacted with potassium sulfite to produce the alkyl glyceryl ether potassium sulfonate. From this synthetic sulfonate, a detergent composition was prepared as follows, all parts by weight.

\ Parts by wt. Water heated to about 135 F. and this temperature maintained 51 Potassium alkyl glyceryl ether sulfonate dissolved in the water 12 Potassium pyrophosphate is added to the above solution Sodium silicate solution containing 4 parts of silicate solids of SiO /Na O ratio of 2:1 is added 9 On standing, part of the alkyl glyceryl ether sulfonate tends to salt out and forms a viscous top layer and some of the phosphate settles out. After cooling, with adequate agitation, as by shaking a can or bottle containing this detergent, a liquid heavy duty detergent of adequate cleansing power can be achieved. Washing solutions prepared from this detergent do not attack aluminum to an objectionable degree. However, they would not be considered satisfactory detergents in the scope of this invention, because of their tendency to separate, as set forth.

Upon admixture of 4 parts of ethyl alcohol, as an assistant solubilizer, with the above composition at a moderately warm temperature, say 90 F., the alkyl glyceryl ether sulfonate is upon standing at room temperature tends to resolve itself into two clear layers. With adequate agitation, as by shaking the can or bottle, this two phase mixture can be used as a heavy duty detergent, the silicate in the composition being sufficient to inhibit corrosion of aluminum by washing solutions prepared from the detergent. This two phase composition is a heavy duty liquid detergent base of great utility in that it can be converted into a marketable detergent by one of several methods. Our preferred method is to add a solubilizer, converting the mixture to a single phase liquid. The two phase base can be converted to a reasonably permanent emulsion by the addition of emulsifying agents or by the addition of finely divided solids such as amorphous silica or clay of the bentonite type. Considered as a detergent base, this two phase liquid detergent is within the scope of the present invention.

The assistant solubilizer is normally added to the mixture right after the alkyl glyceryl sulfonate, to reduce viscosity for mixing purposes. It may be added at any time before the solubilizer is added and be effective as a solubilizing assistant. It appears that the addition of alcohol or other assistant solubilizer causes a resolution of the composition into two clear phases, the top layer containing most of the anionic synthetic detergent in solution. The removal of this detergent from the water in the lower layer enables this layer to completely dissolve the phosphate.

The addition of the solubilizer, in this example, 4 parts of sodium toluene sulfonate, caused the layers to dissolve in one another and become a single phase. This phenomenon takes place only when the anionic comprises a minimum of at least 6% of alkyl glyceryl ether sulfonate. It is in this fashion that the alkyl glyceryl ether sulfonate makes possible the preparation of a single phase heavy duty liquid detergent containing an effective amount of silicate.

Example 11 These materials were of the same character as-used in Examplel.

dissolved. This preparation Parts by Wt. Potassium alkyl glyceryl ether sulfonatewas dissolved in 12 Water at F., this temperature was maintained 51 Potassium pyrophosphate was added to the above solution 20= Ethyl alcohol was used to control viscosity and facilitate blending 4 Sodium silicate solution containing 4 parts of silicate solids of SiO /Na O ratio of 2.0:1 was added 9 Sodium toluene sulfonate was added and the mixture stirred well 4 This composition contained the following-all parts by weight.

Parts by Wt. Potassium alkylglyceryl ether'sulfonate 10 Potassium pyrophosphate 30 Sodium silicate solids 4 Sodium toluene sulfonate 4 Ethyl alcohol 4 Water 44 Inorganic salts from sulfonation, tarnish inhibitors, coloring material, perfume These materials, except for the tarnish inhibitors, coloring material, and perfume, were thesameas. shown in Example I, and were made intoa clear solution in the same manner. Thepyroph'osphatein this example 1s about the upper limit of solubility at room temperature in this preparation, which shows how a proper choice of materials enables a concentrated detergent to be prepared. This preparation did not corrode aluminum significantly. The ethyl alcohol maybe replacedby isopropanol in this example with substantially equal results.

Example I V salts 10 Potassium pyrophosphate 30 Ethyl alcohol 4 Sodium toluene sulfonate 4 Sodium silicate solids, SiO /Na O ratio of 2.0 1 1 4 Water 44 Inorganic salts from sulfonation, tarnish inhibitors, coloring matter and perfume This was blended together: as shown in Example ll. When added to waterin detergent concentrations it had good heavy duty detergent-properties anddid not corrode aluminum. significantly. The ethylalcohol in this formula may be replacedby diethylene glycol monobutyl ether with substantially equal results.v

The aboveexamples showwthat, alkyl glyceryl ether sulfonate will solubilize silicate inflphosphate solutions and-may be: used': to prepare effective-liquid heavy duty synthetic detergentsr If anionic synthetic detergents*otherrthan allcyl glyceryl: are used as the sole anionic in the fop;

ether sulfonate mulations of the above examples, a clear single phase solution is not attained. If, for instance, alkyl benzene sulfonate, where the alkyl is polypropylene averaging about 12 carbons, is used, the addition of alcohol causes two clear layers to form, but they will not blend into a single phase solution upon the addition of a solubilizer and stirring. If an alkyl sulfate, where the alkyl contains at least 50% of radicals from alcohols of to 14 carbon atoms is used, the anionic will not stay in solution but salts out due to insolubility of the potassium alkyl sulfate which can be formed by reaction with the potassium phosphate.

A convenient test for clarity may be made by placing the preparation in a test tube 20 mm. diameter and 150 mm. long and holding for five days at some selected temperature below room temperature, 60" F., 50 F., and 40 F., are commonly used.

In this test highly satisfactory compositions will not cause the alkyl glyceryl ether sulfonate to salt in a viscous or jell-like layer at the top, nor separate a precipitate of phosphate or silicate at the bottom of the tube.

Ordinary visual observation in good light, as looking toward a window, is used to determine the state of the preparation. Compositions not highly satisfactory by very low temperature test can be used as detergents at room temperature-say 70 F.if they become clear and free from separated material at this temperature.

The silicate and the alkali toluene sulfonate preferably are added as the sodium salts. The presence of at least as much sodium ions as are added with these compounds is desirable for improved solubility.

It will be understood that the coloring matter and added at any convenient point in the mixing of the composition, and that perfume may be added after the composition has been prepared and cooled.

The formulas may be varied somewhat from those given in the examples. All of the examples show the use of fatty alcohol containing at least 50% of dodecyl alcohol as the alkyl in the alkyl glyceryl ether sulfonate. For good sudsing properties the use of this alkyl glyceryl ether sulfonate is essential. At the maximum concentrations in solution, the sum of the alkyl glyceryl ether sulfonate and the phosphate will be approximately constant. Each of these components seems to use up about the same amount of solubilizing power. Hence, if the percent of phosphate is raised, the alkyl glyceryl ether sulfonate will have to be lowered by about the same amount, this, of course, being in solutions of maximum concentration at room temperatures. The sum of these two ingredients will be in the range of not over about 40% in concentrated solutions. Totaling up the other ingredients, it will be evident that not less than about 40 parts of water will be required to make the total parts equal 100. Considering the more dilute compositions, it will be seen that 75 parts of water is the maximum that will be required to total 100 parts.

The blending agent or solubilizer should be from about 3.0% to about 8%, less than 3% being ineflfective and more than 8% adding nothing to the performance.

Either potassium tripolyphosphate or potassium pyrophosphate, or mixtures of the two may be used up to the limit of solubility at room temperatures in these compositions.

Our preferred composition contains about 20% pyrophosphate because of the greater solubility and stability of this phosphate.

The alcohols, ethanol or isopropanol used to solubilize the anionic synthetic detergent may be used from about 2% to about 6%. Diethylene glycol monobutyl ether can be substituted for the alcohol as an assistant solu- .sodium silicate solids having a SiO /Na O bilizer. Less than 2% alcohol is undesirable from the point of viscosity and freeze recovery, and more than 6% causes a tendency to separation into two phases.

In the compositions containing about 20 parts of potassium pyrophosphate in about 50 parts of water, the amount of alkyl glyceryl sulfonate must be at least 6% to solubilize the silicate in effective amounts. The amount of alkyl glyceryl ether sulfonate may go as high as 14%, but at the expense of clarity at low temperatures.

What is claimed is:

1. A single phase liquid heavy duty detergent composition consisting essentially of, in parts by weight, from 6 to 14 parts of salts of alkyl glyceryl ether sulfonate of which the cation is an alkali metal, at least 50% of the alkyl groups of the said alkyl glyceryl ether sulfonate being derived from alcohols having from 10 to 14 carbon atoms, from a minimum of 12 parts to a maximum of the limit of solubility at room temperature of a phosphate selected from the group consisting of potassium pyrophosphate, potassium tripolyphosphate and mixtures thereof, 3.5 to 6 parts of sodium silicate solids having a SiO /Na 0 ratio of 1.6:1 to 2.621, 3 to 8 parts of an anionic solubilizer selected from the group consisting of trialkyl phosphates, wherein each of the alkyl groups contains not more than 5 carbon atoms, the alkali metal salts of benzene sulfonate, the alkali metal salts of toluene sulfonate and the alkali metal salts of xylene sulfonate, 2 to 6 parts of an assistant solubilizer selected from the group consisting of ethyl alcohol, isopropyl alcohol and diethylene glycol monobutyl ether, and not less than 40 parts and not more than parts of water.

2. The detergent composition of claim 1 wherein the phosphate is potassium pyrophosphate.

3. The detergent composition of claim 1 wherein the assistant solubilizer is ethyl alcohol.

4. Detergent composition of claim 1 wherein the assistant solubilizer is isopropyl alcohol.

5. A single phase liquid heavy-duty detergent composition consisting essentially of, in parts by weight, 6 to 14 parts of salts of alkyl glyceryl ether sulfonate of which the cation is an alkali metal, at least 50% of the alkyl groups of the said alkyl glyceryl ether sulfonate being derived from alcohols having from 10 to 14 carbon atoms, 12 to 27 parts of a phosphate selected from the group consisting of potassium pyrophosphate, potassium tripolyphosphate and mixtures thereof, 3.5 to 6 parts of ratio of 1.621 to 26:1, 3 to 8 parts of an anionic solubilizer selected from the group consisting of trialkyl phosphates wherein each of the alkyl groups contain not more than 5 carbon atoms, the alkali metal salts of benzene sulfonate, the alkali metal salts of toluene sulfonate and the alkali metal salts of xylene sulfonate, 2 to 6 parts of an assistant solubilizer selected from the group consisting of ethyl alcohol, isopropyl alcohol and diethylene glycol monobutyl ether, suflicient water being present in the composition to bring the total of all components to parts.

6. The detergent composition of claim 5 wherein the phosphate is potassium pyrophosphate.

7. The detergent composition of claim 6 wherein the phosphate is present in the composition in an amount about 20 parts by weight.

References Cited in the file of this patent

Claims (1)

1. A SINGLE PHASE LIQUID HEAVY DUTY DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF, IN PARTS BY WEIGHT, FROMK 6 TO 14 PARTS OF SALT OF ALKYL GLYCERYL ETHER SULFONATE OF WHICH THE CATION IS AN ALKYL METAL, AT LEAST 50% OF THE ALKYL GROUPS OF THE SAID ALKYL GLYCERYL ETHER SULFONATE BEING DERIVED FROM ALCOHOLS HAVING FROM 10 TO 14 CARBON ATOMS, FROM A MINIMUM OF 12 PARTS TO A MAXIMUM OF THE LIMIT OF SOLUBILITY AT ROOM TEMPERATURE OF A PHOSPHATE SELECTED FROM THE GROUP CONSISTING OF POTASSIUM PYROPHOSPHATE, POTASSIUM TRIPOLYPHOSPHATE AND MIXTURES THEREOF, 3.5 TO 6 PARTS OF SODIUM SILICATE HAVING A SIO2/NA2O RATIO OF 1.6:1 TO 2.6:1, 3 TO 8 PARTS OF AN ANIONIC SOLUBILIZER SELECTED FROM THE GROUP CONSISTING OF TRIALKYL PHOSPHATES, WHEREIN EACH OF THE ALKYL GROUPS CONTAINS NOT MORE THAN 5 CARBON ATOMS; THE ALKALI METAL SALTS OF BENZENE SULFONATE, THE ALKALI METAL SALTS OF TOLUENE SULFONATE AND THE ALKALI METAL SALTS OF XYLENE SULFONATE, 2 TO 6 PARTS OF AN ASSISTANT SOLUBILIZER SELECTED FROM THE GROUP CONSISTING OF EHTYL ALCOHOL, ISOPROPYL ALCOHOL AND DIETHYLENE GLYCOL MONOBUTYL ETHER, AND NOT LESS THAN 40 PARTS AND NOT MORE THAN 75 PARTS OF WATER.