US3594322A - Liquid detergent - Google Patents

Abstract

STABLE GERMICIDAL COMPOSITIONS CONTAINING, IN DISSOLVED FORM, CERTAIN RELATIVELY INSOLUBLE HALOGENATED ORGANIC GERMICIDES AND METHODS FOR THE PREPARATION OF SUCH COMPOSITIONS ARE DISCLOSED. THE SPECIFIC GERMICIDES ARE POLYBROMOSALICYLANILIDES AND TRICHLOROCARBANILIDE. THESE GERMICIDES ARE PREDISSOLVED IN SPECIFIC ALKALINE SOLVENTS OR SOLVENT SYSTEMS WHICH INCLUDE FATTY ACID ALKANOLAMIDES, ANIONIC SURFACTANT SOLUTIONS, AND NONIONIC SURFACTANT SOLUTIONS.

Description

United" States Patent M 3,594,322 LIQUID DETERGENT James H. Wilson, Demarest, N.J., assignor to Lever Brothers Company, New York, N.Y.

No Drawing. Continuation-impart of abandoned application Ser. No. 449,862, Apr. 21, 1965. This application Nov. 6, 1967, Ser. No. 680,946

Int. Cl. Clld 9/48, 1/18 US. Cl. 252-106 9 Claims ABSTRACT OF THE DISCLOSURE Stable germicidal compositions containing, in dissolved form, certain relatively insoluble halogenated organic germicides and methods for the preparation of such compositions are disclosed. The specific germicides are polybromosalicylanilides and trichlorocarbanilide. These germicides are predissolved in specific alkaline solvents or solvent systems which include fatty acid alkanolamides, anionic surfactant solutions, and nonionic surfactant solutions.

The present invention relates to stable aqueous base germicidal compositions such as liquid detergent compositions having germicidal properties and to a method for their preparation.

This application is a continuation-in-part of my copending application Ser. No. 449,862, filed Apr. 21, 1965, and now abandoned.

Heretofore, many liquid detergent compositions have been proposed for use in the cleaning of household artic les, such as dishes, glasses, fine china, linens and the like. These liquid detergents are quite popular and have been accepted widely because of their convenience and substantial cleansing properties. However, the formulation of liquid detergent compositions presents a number of special problems.

In general, liquid detergent formulations are highly concentrated solutions of one or more detergents and various performance improving adjuvants. It is essential that the formulations be stable over a Wide range of environmental conditions. They should not be subject to deterioration due to precipitation of solid material or separation of liquid phases when exposed to severe storage conditions over a prolonged period of time. In order to provide stable concentrated solutions of several ingredients it is necessary to formulate the liquid detergent compositions within fairly strict specifications. It will be appreciated that any alteration of such rigidly balanced compositions by the admixture of an additional ingredient necessitates a rebalancing of the formulation or the employment of special formulating techniques in order to maintain a degree of stability and performance equivalent to the original formulations.

Synthetic detergents of the type generally employed in liquid detergent formulations are known to possess a certain degree of germicidal character. Unfortunately, however, they are not all equally effective against a wide variety of bacteria. It is therefore desirable to provide liquid detergent compositions which have a uniform degree of germicidal activity against a broad spectrum of bacteria. This can be accomplished through the incorporation in the detergent compositions of a germicidal agent. However, the simple addition of a germicide to a detergent formulation has not proven to be an effective means of providing stable homogeneous products in which the germicide remains dissolved.

It has been found that halogenated organic germicides, such as polybrominated salicylanilides, are not easily dissolved in a liquid detergent composition. Polybro- 3,594,322 Patented July 20, 1971 ice.

minated salicylanilides such as 3,4,S-tribromosalicylani lide, 3,S-dibromosalicylanilide, and -4,5-dibromosalicylanilide have very low solubility in most common solvents, such as water, ethyl alcohol, 'isopropyl alcohol, propylene glycol, glycerine, and the like. Attempts to predissolve the germicide in various components of the composition or in mixtures of components have not been completely successful. For example, 3,4,S-tribromosalicylanilide was found to be insoluble in ammonium xylenesulfonate even at temperatures up to 200 F. This germicide is also insoluble in ethanol at temperatures up to F. Attempts to predissolve the germicide in relatively dilute aqueous solutions of various nonionic detergents were unsuccessful in that While initial solubility was achieved at elevated temperatures the germicide came out of solution when the temperature was lowered to room temperature.

It will be appreciated that a major problem in pro viding stable germicidal detergent formulations containing slightly soluble germicides involves the discovery and development of methods for dissolving a germicidally elfective amount of the germicide in the formulations and for preventing the dissolved germicide from settling out or precipitating at later stages in the processing operation or during storage.

It is an object of this invention to provide stable solutions of aqueous base liquid detergent compositions which contain a relatively insoluble halogenated organic germicide.

It is another object of this invention to provide a meth od for providing solutions of a relatively water-insoluble polyhalogenated germicide in an aqueous base composition.

A further object of this invention is to prevent precipitation of initially dissolved organic germicides during subsequent processing and during storage.

It is a still further object to provide aqueous germicidal detergent formulations which are stable over a range of pH, concentration, and temperature at which initial solubility of the germicide could not be achieved.

These and other related objects can be achieved by predissolving the germicide in a selected solvent and then incorporating the resulting solution into the balance of the final formulation.

It has been unexpectedly discovered that certain classes of solvents and preferably particular solvents within the classes are capable of dissolving slightly soluble halogenated germicides and imparting stability to water-containing solutions prepared by adding the initially dissolved germicide to a final formulation such as a Water-containing liquid detergent formulation. These materials are referred to as selected solvents. They have been effective as solubilizing and solution-stabilizing materials for difiicult-to-dissolve germicides as herein described. When a particular solvent system is described as being alkaline, a pH of at least about 7 and preferably at least about 9.5 is intended.

The solvents suitable for the above-mentioned use are:

(1) Alkaline mixtures of Water and alkane diols having from 2 to 6 carbon atoms containing up to about 50 weight percent water. Preferred mixtures are 1:1 mixtures of water and a glycol selected from the group consisting of ethylene glycol, propylene glycol, hexylene glycol, and 1,2- butylene glycol.

(2) Polyethers such as polyethylene glycols. Preferred materials include polyethylene glycols having from 2 to 6 carbon atoms, e.g., diethylene glycol, and the monobutyl ether of diethylene glycol. These materials can be combined with Water to provide a solvent system comprising from about 5 to about 60 Weight percent Water, and the pH can be adjusted with any suitable hydroxide.

(3) Fatty acid alkanolamides having from about 6 to 18 carbon atoms in the fatty acid portion of the molecule. Illustrative materials include lauric monoethanolamide, capric monoethanolamide and the like. Preferred materials are the lauric monoand diethanolamides.

(4) Alkanolamines preferably the mono-, di-, and triethanol amines.

(5) Solutions of nonionic surface active agents containing at least about 25 weight percent of the surface active agent. Preferred nonionics include alkyl phenols condensed with from about 5 to about 9 moles of ethylene oxide, particularly octyl and nonyl phenols. Illustrative examples of available materials are the condensate of about 5 moles of ethylene oxide with octylphenol, the condensate of about 9 moles of ethylene oxide with nonylphenol, and alkyl phenoxy polyoxyethylene ethanol (Igepol CA 720).

(6) Alkaline solutions of anionic surface active agents particularly alkyl benzene sulfonates and sulfated fatty alcohol-ethylene oxide condensates. Suitable materials include the well-known alkyl sulfates, alkyloxysulfonates, alkylisethionates, alpha-sulfo soaps, sulfated rnonoglycerides and the like. Particularly preferred anionics are dodecyl benzene sulfonates and condensates of ethylene xide and fatty alcohol sulfates.

Due to the compatibility of the initial germicide solution with the final formulation, certain selected solvents characterized by a solubilizing and solution stabilizing effect are preferred. These preferred solvents are: (I) lauric diethanolamide, (2) lauric monoethanolamide, (3) diethylene glycol, (4) diethylene glycol monobutylether, (5) alkaline mixtures of water and hexylene glycol containing up to about 50% water, (6) alkaline solutions of anionic detergents containing at least about 25 of the detergent, (7) aqueous solutions of nonylphenol condensed with from about 5 to about 9 moles of ethylene oxide, containing at least about 25% of the condensate, and (8) aqueous solutions of octyl phenol condensed with about 5 moles of ethylene oxide containing at least about 25 of the condensate.

The slightly soluble halogenated organic germicides which are contemplated are well-known materials. Illustrative examples of such germicides are the normal and alkali metal (e.g., sodium and potassium) salt forms of 4' monobromosalicylanilide, 5-monobromosalicylanilide, 4',5 dibromosalicylanilide, 3,5 dibrornosalicylanilide, 3,4,5-tribromosalicylanilide, 3,3',4',5-tetrabromosalicylanilide, and trichlorocarbanilide. The preferred halogenated organic germicides are 3,4,S-tribromosalicylanilide, 4',5- dibromosalicylanilide, the alkali metal salts of these materials, and mixtures thereof containing at least about 50 percent by weight of 3,4,S-tribromosalicylanilide or an alkali metal salt thereof.

These halogenated organic germicides are employed in germicidally effective amounts, that is, in amounts which are sufficient to provide the desired degree of germicidal character in the final product. Thus, generally from about 2 to about parts by weight of the initial germicide solution, i.e., in the selected solvent, are blended with from about 98 to about 85 parts by weight of an aqueous formulation containing detergent components in order to provide a final formulation containing from about 0.05 to about 3 Weight percent and preferably from about 0.3 to about 1 weight percent of the germicide.

The solvent is present in suflicient quantity to completely dissolve all of the germicide employed. It will be appreciated that the amount of the solvent must be within the limits allowed by the final formulation. In general, the germicide can be dissolved in about several times its own weight of the solvent, and it is preferred to use from about a 5 to about 30 fold amount of the solvent, based on the amount of the germicide. If the resulting solution is found too viscous for easy handling, it can be thinned with some compatible co-solvent, such as a short chain alkanol, or a short chain alkylaryl sulfonate, such as ammonium xylene sulfonate.

The amount of the solubilizing and solution-stabilizing adjuvant can be conveniently referred to as a solubilizing amount and this term is intended to refer to an amount which is capable of providing initial solubility and continued solubility in the final formulation.

It has been found that when a polyhalogenated germicide has been initially dissolved in the selected solvent, the resulting solution can be added to and admixed with a wide variety of aqueous base compositions which may be detergents, soaps, disinfectants, sanitizers, and the like. Moreover, the pH of the final composition can be adjusted to meet the use requirements to a level at which germicide could not have been initially dissolved. In this manner, stable germicidal compositions having a pH from about 6 to about 8 and preferably from about 6 to 7 can be provided.

In preparing the stable germicidal compositions of this invention the germicide is added to and dissolved in the selected solvent. If the solvent itself does not have a high enough pH, suitable hydroxides, such as ammonium hydroxide, an alkali metal hydroxide, e.g., sodium hydroxide, potassium hydroxide, and the like, can be used to raise the pH. Agitation or elevated temperatures can be employed to facilitate solution. When the resulting solution is clear, the pH of the solution may be reduced or the solution may be admixed with other components of the final formulation before the pH of the resulting final formulation is adjusted. The pH can safely be adjusted to levels which are as low as about 6.0 without danger of loss of the germicide by the formation of insoluble precipitates. The pH can be conveniently reduced by means of dilute sulfuric acid, dilute sulfonic acid, glacial acetic acid, and the like. It is to be understood that the pH need not be adjusted but may be left at relatively high levels as, for example, in heavy duty detergent formulations.

Broadly, stable formulations as herein disclosed comprise from about 1 to about 20 weight percent and preferably about 2 to about 6 weight percent of the selected solvent or a mixture of selected solvents, from about 0.1 to about 3 weight percent and preferably from about 0.3 to about 1 weight percent of the germicide, from about 3 to about 35 weight percent and preferably 0 about 5 to about 15 weight percent of an organic detergent. The formulation can also contain various perfumes, dyes, fillers, emollients, and other well-known additives and adjuvants, commonly employed in such formulations.

Sutiable liquid detergent formulations containing conventional organic detergent components with which the dissolved helogenated organic germicides can be blended are, for example, those comprising aqueous solutions of long chain alkylaryl sulfonates, short chain alkylaryl sulfonates, alkali metal phosphates, fatty alcohols, sulfated alcohol-ethylene oxide condensates, alkalies, dyes, brighteners, perfumes, and other compatible adjuvants.

Formulations in which the halogenated organic germicides are present in an amount of from 0.1 percent to 1 percent can be provided through the practice of this invention. Such formulations may contain from about 5 to about 30 percent of a long chain alkylbenzene sulfonate preferably having from about 10 to 18, preferably about 12, carbons in the alkyl chain, about 3 to about 15 percent of a sulfated dodecylphenol condensed with ethylene oxide in a 1:6 mole ratio, about 3 to about 15 percent of a sulfated fatty alcohol condensed with ethylene oxide in a 1:35 mole ratio, up to about 11% of a fatty (C to C alcohol, about 2 to about 15 percent of lauric diethanolamide, about 8 to about 15 percent of a short chain alcohol such as ethanol, up to about 5 percent of @nylphenol condensed with ethylene oxide in a mole ratio of about 1:9, about 5 to about 15 percent of a polyphosphate, various perfumes, colorants, and opacifiers, as needed, and water to make The above ingredients are all given in terms of Weight percent.

Specific illustrative formulations of suitable liquid detergents containing 3,4,S-tribromosalicylanilide are set forth in Table I below.

TABLE I Percent by weight Components 1 2 3 4 5 6 Polystyrene latex opaeifier 0.8 O 8 6 1.2

Water and inert impurities" The above six formulations can be prepared by dissolving the 3,4,S-tribromosalicylanilide in the lauric diethanolamide at a temperature of about 80 C. The resulting solution can be cooled and then blended with the remaining components of the final formulation.

The following examples 'will further illustrate the practice of the invention.

EXAMPLE 1 Four grams of a halogenated organic ger-micide containing about 98 weight percent 3,4',5-tribromosalicylanilide were added to 20 grams of lauric diethanolamide (pH of about 12.8) at a temperature of about 80 F., and the mixture stirred for about minutes. The resulting solution was then allowed to stand overnight at room temperature to allow entrapped air to escape. A clear, stable, and homogeneous solution was obtained.

EXAMPLE 2 Four grams of the halogenated organic germicide described in Example 1 were mixed with and dissolved in a mixture (pH about 12.8) of 20 grams of lauric diethanolamide and 10 grams of ethyl alcohol denatured with about 1 percent by volume of diethylphthalate at a temperature of 80 F. A clear, stable solution was obtained upon cooling.

EXAMPLE 3 Four grams of the halogenated organic germicide described in Example 1 were mixed with and dissolved in a blend (pH about 12.8) of 20 grams of lauric diethanolamide and 10 grams of 40% ammonium xylenesulfonate at a temperature of 80 F. Upon cooling, a clear, stable solution was obtained.

EXAMPLE 4 Twenty grams of a halogenated organic germicide containing about 98 weight percent 3,4',5 tribromosalicylanilide were added to 100 grams of lauric diethanolamide (pH about 12.8) and mixed for one hour at about 80 F. The germicide dissolved rapidly to provide a clear solution. The pH of the solution was then reduced to about 6.4 by the addition of grams of glacial acetic acid. After standing overnight, the solution was still clear and no evidence of precipitation was apparent.

In a similar experiment, the pH of 100 grams of lauric diethanolamide (pH about 12.8) was reduced to about 6.4 by the addition of 15 grams of glacial acetic acid, then grams of the 3,4',5-tribromosalicylanilide (98%) were iii 6 added to and mixed with the solvent at F. The resulting solution was opaque, indicating insolubility of the germicide in the solvent.

EXAMPLE 5 Twelve grams of a halogenated organic germicide containing about 98 weight percent 3,4,5 tribromosalicylanilide were dissolved in 60 grams of triethanolamine at a temperature of about 80 F, and a pH of about 9.5. The resulting clear solution was diluted with 20 grams of water to provide a clear solution having a pH of about EXAMPLE 6 The undiluted solution of 3,4,5-tribromosalicylanilide described in Example 5 was incorporated into a liquid detergent composition comprising ammonium dodecylbenzene sulfonate, ammonium salt of a sulfated fatty alcohol condensed with ethylene oxide, lauric diethanolamide, ainmonium xylene sulfonate, perfume and water. The pH of the final composition was then adjusted to about 6.2. The resulting solution was clear. In these experiments, a clear solution was obtained whether the germicide was added to the detergent components prior to or after the addition of the lauric diethanolamide component of the liquid detergent.

Similar experiments in which a solution of the germicide in monoethanolamine was added to a formulation of detergent components and then the pH reduced to about 6.2 also provided clear solutions.

EXAMPLE 7 A liquid detergent formulation comprising:

Grams Water 225 Ammonium xylenesulfonate (40%) 222 Ammonium hydroxide (28% NH 43 Dodecylbenzenesulfonic acid (88.5%) 182 Lauric diethanolamide 60 Ammonium salt of sulfated condensate of dodecylphenol and 6 moles E0. (50 active) 211 Perfume 1.5 Ammonium hydroxide to pH 6.2 and water to a total of 1,000 grains.

was prepared and the pH thereof adjusted to about 10.2 with ammonium hydroxide. About four grams of 3,4',5- tribromosalicylanilide were dissolved in this detergent composition to provide a solution which remained clear overnight. When the pH of the resulting solution was reduced to about 6.2 with dilute sulfuric acid, the product remained clear and no precipitation was apparent.

EXAMPLE 8 The solubility of 3,4,5-tribromosalicylanilide in alkaline anionic surfactant solutions of relatively high con centration is shown in the following series of formulations.

Percent by weight Appearance after 3 days 1 From Ucane 12.

2 Contains approximately 13-14% ethyl alcohol.

3 Heavy white ppt.

4 Clear homogeneous liquid.

5 Suspended particles.

As those skilled in the art will readily perceive, numerous advantages are to be gained through the practice of this invention. By dissolving the germicide by means of a selected solvent, a uniform distribution throughout the liquid product is achieved. If the germicide is not dissolved, it would remain as discrete particles which would settle to the bottom of the mixing tank or other container. Moreover, improved uniform germicidal activity is provided, since there are no local concentrations of poorly dispersed germicide. It has been further observed that more uniform and brighter color is provided in the finished product by minimizing the color of the germicide through its solubilization. Improved operation of equipment is achieved, since there are no particles or agglomerates of germicide to clog strainers or adhere to the sides of mixing and storage tanks. Constant agitation of the finished liquid detergent is unnecessary. Such agitation would be necessary if the germicide were present as suspended particles. Moreover, the use of a premixed solution of germicide in a selected solvent provides for the preparation of master-mixes which improves uniformity, reduces the effect of small weighing errors, and eliminates the necessity of multiple weighings of dry material.

It will be understood by those skilled in the art that the embodiments herein described are merely exemplary of the selected solvents and method for dissolving the disclosed halogenated germicides in such solvents and that many modifications and variations are possible without departing from the spirit of the invention. Accordingly, all such modifications and variations are deemed included within the scope of the appended claims.

What is claimed is:

1. A process for preparing stable aqueous liquid organic detergent solution compositions consisting essentially of a halogenated organic germicide selected from the group consisting of mono-, di-, triand tetrabrominated salicyl anilides and trichlorocarbanilide; said process comprising the .steps of (1) predissolving the germicide in a solubilizing amount of an alkaline solvent selected from the group consisting of:

(1) fatty acid alkanol amides having from about 6 to about 18 carbon atoms in the fatty acid portion of the molecule;

(2) alkaline aqueous solutions of nonionic alkyl phenol-ethylene oxide condensate surface active agents selected from the group consisting of octyl and nonyl phenols condensed with from 5 to 9 moles of ethylene oxide containing at least about weight percent of the surface active agent; and

(3) alkaline aqueous solutions of anionic sulfonated or sulfated surface active agents selected from the group consisting of alkyl benzene sulfonates, sulfated fatty alcohol-ethylene oxide condensates and sulfated dodecyl phenol-ethylene oxide condensates containing at least about 25 weight percent of the surface active agent; and

(2) blending from about 2 to about 15 parts by weight of the resulting solution with from about 98 to about parts by weight of an aqueous liquid nonionic or anionic organic synthetic detergent formulation.

2. The process as defined by claim 1 wherein the germicide is 3,4,5-tribromosalicylanilide.

3. The process as defined by claim 1 wherein the alkaline solvent is lauric diethanolamide.

4. The process as defined by claim 1 wherein the solubilizing amount of the alkaline solvent is from about 5 to about 30 fold the amount of the germicide.

5. The process as defined by claim 1 wherein the final formulation is neutralized to a pH of from about 6 to about 8.

6. A stable aqueous liquid organic detergent solution composition consisting essentially of a blend of (A) from about 2 to about 15 parts by weight of a solution of a halogenated organic germicide selected from the group consisting of mono-, di-, triand tetrabrominated salicylanilides and trichlorocarbanilide dissolved in a solubilizing amount of an alkaline solvent selected from the group consisting of (1) fatty acid alkanol amides having from about 6 to about 18 carbon atoms in the fatty acid portion of the molecule;

(2) alkaline aqueous solutions of nonionic alkyl phenol-ethylene oxide. condensate surface active agents selected from the group consisting of octyl and nonyl phenols condensed with from 5 to 9 moles of ethylene oxide containing at least about 25 weight percent of the surface active agent; and

(3) alkaline aqueous solutions of anionic sul-fonated or sulfated surface active agents selected from the group consisting of dodecyl benzene sulfonates, sulfated fatty alcohol-ethylene oxide condensates and sulfated alkyl phenol-ethylene oxide condensates containing at least about 25 weight percent of the surface active agent; and

(B) from about 98 to about 85 parts by weight of an aqueous liquid nonionic or anionic organic synthetic detergent formulation.

7. The composition as defined by claim 6 wherein the germicide is 3,4,5-tribromosalicylanilide.

8. The composition as defined by claim 6 wherein the alkaline solvent is lauric diethanolamide.

9. The composition as defined by claim 6 wherein the solubilizing amount of the solvent is from about 5 to about 30 fold the amount of the germicide.

LEON D. ROSDOL, Primary Examiner P. E. WILLIS, Assistant Examiner US. Cl. X.R.

"O-IOSU (5,) UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Plan: No. SJ 59 3 mu July 20, 1971 lnvlntorfl) ,Zgmgg [1. E1 [59;

It in certified and that said Letter! that nrror appurl tn the ed u shown below:

j Column '6 lino 51 "hclogunatod" should be halogenated Column 8, lino 32 "dodecyl" should be --allqyl--; line 34, "alkyl" should be --dodecyl-- Signed and lanlnd thin 11th day of January 1972.

(sum ALLoIt! :-L-AHD HEM-INNER JR. ROBERT OOTTSOHALK Attnntlng, Ofl'toor Ac ting Commluionor of Patents