US3862050A

US3862050A - Sodium alkyl ether sulfate c{hd 12{b -c{hd 14 {b soap blends for optimum sudsing in hard surface cleaners

Info

Publication number: US3862050A
Application number: US158596A
Authority: US
Inventors: Harry J Aubert
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1971-06-30
Filing date: 1971-06-30
Publication date: 1975-01-21
Anticipated expiration: 1992-01-21
Also published as: CA982899A

Abstract

Detergent compositions containing water-soluble alkyl ether sulfate/soap blends which provide optimum sudsing during cleaning operations are disclosed.

Description

Unlted States Patent 11 1 1111 3,862,050 Aubert 1 1 Jan. 21, 1975 [5 1 SODIUM ALKYL ETHER 3,211,661 10/1965 Smith 1. 252/153 SULW?TIEC12- C14 P L DS O 3,281,367 10/1966 Jones et a1 OPTIMUM SUDSING IN HARD SURFACE E233 252/117 CLEANERS [75] Inventor: Harry J. Aubert, Center Twsp., FOREIGN PATENTS OR APPLICATIONS Dearbom County Ind 1,180,114 4 1970 Great Britain 252/321 855,893 12/1960 Great Britain 1 252/551 [73] Assignee: The Procter & Gamble Company, 797,119 6/1958 Great Britain 252/551 OTHER PUBLICATIONS [22] Flled: June 1971 Phosphate Replacements: Problems with the Wash- [21] Appl. No.: 158,596 day Miracle, by Allen L. Hammond, Science, Vol.

172, pages 361-363, Apr. 23, 1971.

[52] US. Cl 252/117, 252/110, 252/121, Primary Examiner Mayer Weinblatt 252/532, 252/551, 252/DIG. 14 A E D 1 L Alb h 51 Int. Cl. Clld 9/12, c1 1d 9/32,C11d 9/46 f zs g s JG Richard [58] Fleld of Search 252/110, 121, 117 0 wine; Julius P. Filcik [56] References Cited UNITED STATES PATENTS 1571 ABSTRACT 2,560,839 7/1951 Ayo et al. 252/109 Detergent Compositions Containing Water-Soluble dlkyl 2,954,347 9/1960 St. John et a1. 252/109 ether sulfate/soap blends which provide optimum 3,052,635 9/1962 Wixon 252/528 sudsing during cleaning operations are disclosed. 3,086,944 4/1963 Wedell 252/321 X 3,179,599 4/1965 Eaton et al. 252/153 7 ClalmS, N0 Drawmgs SODIUM ALKYL HE S LEATE c,,-c SOAP BLENDS FOR OPTIMUM SUDSING IN HARD SURFACE CLEANERS FIELD OF THE INVENTION This invention relates to detergent compositions suitable for hard surface cleaning; more particularly it relates to liquid detergent compositions comprising alkyl ether sulfate and fatty acid soap blends. These alkyl ether sulfate/soap blends are characterized by desirable sudsing profiles, i.e., those which are not too high initially and fairly stable thereafter.

The cleaning power of a liquid detergent is frequently judged by the housewife as directly related to the sudsing profile of the detergent. Consequently, a detergent which does not exhibit desirable sudsing characteristics during the cleaning operation is considered by the housewife, in some cases, to be an inferior cleaning product. Similarly, a composition having excess suds tends to be considered undesirable insofar as rinsing operations, particularly on hard surfaces, are hampered. Ideally, a suitable cleaning composition should initially have a desirable level of sudsing and a fairly constant suds level during cleaning operations so as to connote desirable cleaning effects and should not suds excessively.

A detergent composition suited for hard surface cleaning operations should also be capable of providing cleansing action without harmful effect on the cleansed surfaces or on the skin of the user.

It is therefore an object of this invention to provide detergent compositions having improved sudsing characteristics in hard surface cleaning operations (i.e., not too high initially and fairly stable thereafter).

It is a further object of this invention to provide detergent compositions capable of washing tile floor, appliances, painted walls and the like without damage to the surface.

It is yet another object of this invention to provide a detergent composition which does not adversely effect the hands of the individual during cleaning operations.

SUMMARY OF THE INVENTION These and other objects which will become apparent from the following detailed description'are attained in accordance with the present invention by the provision of liquid hard surface cleaning compositions which comprise: an alkyl ether sulfate (AE S) of the formula wherein R is alkyl of from to 16 carbon atoms, x has an average value of from 1 to 10, especially from 2 to 4 and M is alkali metal, ammonium, or substitutedammonium; an alkali metal fatty acid soap having from 12 to 14 carbon atoms; and the balance water; said alkyl ether sulfate and alkali metal soap being in a weight ratio of from 1:1 to 30:1.

These hard surface cleaning compositions are characterized by optimum sudsing profiles for cleaning operations. They provide sufficient sudsing levels as to connote desirable cleaning operations. They are suited to the cleaning of waxed floors and other surfaces without wax-removal thereby leaving a rebuffable surface and are not harsh on the skin.

The detergent compositions of the invention can obtain a water-soluble inorganic or organic alkaline builder salt. Suitable weight ratios of detergent (AE S and soap) to builder are from about 4:1 to 1:20. The preferred ratio of the detergent to builder is 1:1 to about 1:10.

DETAILED DESCRIPTION OF THE INVENTION An essential detergent component of the hard surface cleaning compositions of the invention comprises a sulfated and neutralized ethoxylate detergent. The sulfated and neutralized ethoxylate detergents of the invention are well known. Their preparation and properties are described, for example, in British Pat. No. 791,704 (Mar. 12, 1958); British Pat. No. 797,119 (June 25, 1958); US. Pat. No. 3,179,599 to Eaton et al. (Apr. 20, 1965); The Journal of the American Oil Chemists Society, 36 pp. 24l244 (June 1959); The Journal of the American Oil Chemists Society, 37, pp. 427-430 (September 1960); and The Journal of the American Oil Chemists Society, 45, pp. 738-741 (November 1968).

These detergents are termed hereinafter for convenience as alkyl ether sulfates. The alkyl ether sulfates of the invention correspond to the formula R (OC HQ OSO M hereinbefore described. For purposes of the present invention, the designation of the value of x as an average value of from about 1 to about 10 refers to the number of moles of ethylene oxide reacted per mole of high molecular weight alcohol to form the ethoxylated alcohol product which is subsequently sulfated and neutralized to provide the alkyl ether sulfate component of the invention.

The alkyl ether sulfate component of the invention comprises from 1% to 20% by weight of the liquid detergent composition of the invention. Preferred from the standpoints of desirable sudsing and economic considerations is an amount of from 2% to 18%.

The alkyl ether sulfates of the invention can be prepared by sulfation and neutralization of a condensate prepared by reaction of from 1 to 10 moles of ethylene oxide per mole of a monohydric alcohol having from about 10 to about 16 carbon atoms. Suitable alcohols for preparation of the condensate include those derived from fats and synthetic alcohols. Examples of these alcohols include decyl alcohol, dodecyl alcohol, oxobased tridecyl alcohol, tetradecyl alcohol, hexadecyl alcohol and alcohols derived by reducing fatty oils such as coconut oil, palm oil, kernel oil, babassu oil, coconut fatty acids or their alkyl esters. Chain lengths of less than ten carbon atoms give reduced detergency and sudsing while those greater than 16 tend to reduce the quantity of suds which are produced. Preferred alcohols are the straight-chain alcohols having from 12 to 14 carbon atoms and wherein at least of the alkyl groups contain 12 carbon atoms. Especially preferred herein are the alcohols corresponding in chain lengths to the middle-cut coconut alcohols. The term alkyl is intended to include the olefinic as well as true alkyl groups and includes those derived from fatty origin such as oleyl alcohol and the like.

Sulfation and neutralization of the condensation products of ethylene oxide and higher molecular alcohol, described hereinbefore, can be conducted by known methods. The sulfated product is neutralized by reaction with an alkali metal base, (e.g., sodium hydroxide, potassium hydroxide) ammonium hydroxide or alkylol-substituted ammonias to provide radicals corresponding to M hereinbefore defined. Preferred alkylol-substituted ammonias are mono-, di-, and triethanol amines, mono-, di-, and tri-isopropanol amines and mono-, di-, and triglycerol amines, i.e., those in which the alkylol group has from 2 to 3 carbon atoms. Depending upon the neutralizing agent employed in carrying out neutralization of the sulfated alcohol ethoxylate, M in the hereinbefore described formula will be a water-solubilizing-cation such as sodium, potassium, ammonium, trimethanolamine or the like.

Soaps suitable for use in the present invention are the soaps of fatty acids containing from 12 to 14 carbon atoms. It has been found that sodium soaps of fatty acids having longer chain lengths, e.g., sodium C /C soaps suppress suds formation to an undesirable extent. The fatty acid soaps of the invention can be synthetically prepared by neutralization of fatty acids prepared by known methods (e.g., by the oxidation of petroleum, or by hydrogenation of carbon monoxide by the Fischer-Tropsch process). Alternatively they can be separated, as by fractionation, from mixtures of soaps obtained from fatty acids derived from natural sources such as, for instance, from plant or animal esters (e.g., palm oil, coconut oil, babassu oil, soybean oil, castor oil, tallow, whale and fish oils, grease, lard, and mixtures thereof).

Mixtures of soap compounds suitable herein include those having a predominating amount, i.e., at least about 80%, of soap compounds in the C to C range. A preferred mixture of soaps is that derived by fractionation of middle-cut coconut alcohol having the following approximate chain length distribution: 3% C 2% C 66% C 20% C and 9% C to substantially remove soaps outside the C range. The specificity of the fatty acid soap is very important to suds height stability. Unfractionated coconut fatty acid soap mixtures, for example, are unsatisfactory from the standpoint of suds stability.

The alkyl ether sulfate and soap components together comprise from 3% to 20% of the compositions of the invention. The weight ratio of alkyl ether sulfate to fatty acid soap is about 1:1 to 20:1; the preferred ratio is from about 2/1 to 10/ 1. Normally, the total soap content of the composition is from about 0.5% to 5.0% by weight, especially from 1.0% to 2.0% by weight of the total composition. Normally, the total amount of water is at least about 60% to 80% by weight of the composition. The amount of water and other components will be proportioned to provide solubilizing effects so as to form a homogeneous liquid.

The present invention enables the provision of heavy duty liquid detergent compositions having excellent sudsing profiles and mildness properties. A preferred composition of the invention consists essentially of: (a) about 2% to 18% by weight of a sodium alkyl ether sulfate containing an average of 3 ethylene oxide groups and wherein the alkyl contains from about 10 to 16 carbon atoms; (b) about 1.0% to 2.0% by weight of an alkali metal soap having from 12 to 14 carbon atoms; (c) from about 5% to 20% of a water-soluble builder salt; and (d) from 60% to 80% water.

Sequestering or buffering builders can be employed in the compositions of the invention. Suitable builders include the water-soluble organic and inorganic builders.

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 hexaphosphate, sodium sesquicarbonate, sodium orthophosphate, potassium bicarbonate, and the sodium salts of nitrilotriacetic acid. The preferred inorganic alkaline builders according to this invention are the alkali metal pyrophosphates. Potassium is the preferred alkali metal used in liquid compositions.

Examples of suitable organic alkaline 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 citric acid can be suitable employed. The alkali metal salts of phytic acid, e.g., sodium phytate are also suitable as organic alkaline sequestrant builder salts (see US. Pat. No. 2,739,942).

Polyphosphonates are also valuable builders in terms of the present invention including specifically sodium and potassium salts of ethane-l-hydroxy-l,1- diphosphonic acid, sodium and potassium salts of methylene diphosphonic acid sodium and potassium salts of ethylene diphosphonic acid, and sodium and potassium salts of ethane-1,1,Z-triphosphonic acid. Other examples include the alkali metal salts of ethane- 2-carboxy-1,l-diphosphonic acid, hydroxymethanediphosphonic acid, carbonyldiphosphonic acid, ethane- 1-hydroxy-1,l,2-triphosphonic acid, ethane-Z-hydroxy- 1,1,2-triphosphonic acid, propane-1,1,3,3-tetraphosphonic acid, propane-l,l,2,3-tetraphosphonic acid, and propane-1,2,2,3-tetraphosphonic acid.

The compositions of the invention provide a pH in washing solutions in the range of from 7 to l l. The pH will vary depending upon the presence or absence of builder salts, the amount of such salts employed and the like. Built formulations will normally have a pH in the range of from 10 to l 1 and provide excellent cleaning results for hard surfaces which have high fat, greasy type soils. Unbuilt compositions will provide a pH in solution in the range of 7 to 11.

Minor ingredients can be included in the formulations to give the invention certain desirable characteristics. For example, preservatives (such as formaldehyde), perfumes, dyes and solubilizing agents can be added without affecting the desirable properties of the invention. Suitable optional surfactants for use herein include linear alkyl sulfates, nonionics, zwitterionics and amides.

A hydrotrope agent can be employed in the compositions of this invention; suitable hydrotropes herein are the watersoluble alkali metal salts of toluene sulfonate, cumene sulfonate, benzene sulfonate, xylene sulfonate and the like. The preferred hydrotropes are the potassium or sodium toluene sulfonates and cumene sulfonates. The hydrotrope salt can be added, when desired, at levels of 1% to about 12% by weight of the composition, preferably from 8% to Normally, a hydrotrope is added to aid in rendering the product homogeneous.

The compositions of this invention are prepared by conventional methods; for example, the constituents of the compositions can be mixed together in the presence of, e.g., about 70% water, with agitation or stirring to provide a substantially homogeneous solution.

Foaming characteristics of hard surface cleaning formulations are important from the standpoint of the average housewife. Product cleaning power is usually associated with the suds height or stability of these compositions. The compositions of the present invention exhibit desirable foaming and cleaning characteristics tervals the mop was pulled out of the solution and squeezed. The process was continued for a total of 60 seconds and another suds reading was taken (suds reading time, 2). The sequence was continued for each additional suds height reading. A total of 60 seconds was consumed for every suds height reading. City tap water containing from 7 to 10 grains/gallon of hardness was employed.

An optimum suds level of alkyl ether sulfate/soap blends is from 2 to 5.5 inches; values below 1 inch or above 6 inches are considered undesirable.

The following Examples illustrate preferred embodiments utilizing C or C fatty acid soaps in combination with an alkali metal alkyl ether sulfate.

Ingredients Example I Example ll Example 111 Example lV Control R--O-(CH CH O) SO M 17.5% 2% 17.5% 2% Na C soap (92% C 5% C 3% C 1.75% 1% Na C soap (93% C 1.75% 1% 3% 10; 3% C14) Sodium tripolyphosphate 10% 10% Sodium carbonate 4.0% 4.0% Sodium toluenesulfonate 8.0% 8.0% 8.0% 8.0% 8.0% Minor ingredients (i.e., dyes,

perfumes, etc.) 0.5% 0.5% 0.5% 0.5 0.5% Water 71.25% 74.50% 71.25% 74.5% 69.50% pH 7.8 10.5 7.8 10.5 7.8 Unfractional middle-cut coconut sodium soap 2% R Middle cut coconut (3% C 2% C 66% C11; 20% C 9% C x 3 (average value) M Sodium at use concentration and at the same time are mild to the skin.

The compositions of the invention can be used for either commercial or household hard surface cleaning operations with only minimal wax removal, thereby leaving a rebuffable surface after washing. These compositions can be used to clean a wide variety of surfaces without fear of damage to the surface. The unbuilt formulas (e.g., neutral compositions) are especially suited to use in hard surface cleaning operations with minimized detergent or alkali burn or irritation to the user. No rinsing is required after washing and streaking is minimized because of the low residual suds. The suds height and concentration are stable enough to promote excellent cleaning of the surface being cleaned.

The following compositions, in which the percentages are by weight, will serve to illustrate but not limit this invention. Each of the compositions in the Examples gives in solution a pH within the desired range of from about 7.5 to about 10.5.

EXAMPLES I IV The household usage suds test (HUST), which was used to evaluate compositions of the invention, was conducted by allowing 1 gallon of water (at specified hardness and temperature) to run from the faucet into a bucket containing one-fourth cup of the cleaning solution. The cleaning solution was located in the bottom of a two-gallon pail. The suds height (in inches) was read immediately. The initial suds reading corresponds to suds reading time zero. One minute later, the suds height was again read (suds reading time, 1). A sponge mop was dipped into the solution and at 10-second in- The compositions of Examples 1 to [V are illustrative of built and unbuilt formulations of the present invention.

The compositions of Examples 1 to IV were evaluated using the method set forth in the household usage suds test. The compositions had a water hardness of 7 grains/gallon and a temperature of 1 15F. For comparison purposes, the control sample described hereinbefore was evaluated for sudsing profiles. The unfractionated control sample was derived from the middle cut of coconut alcohol having the following chain length distribution: 3% C 2% C 66% C 20% C and 9% C Compositions l to 1V in Table I correspond to the respective examples described hereinbefore. The results were as follows:

TABLE I Suds Reading Height (inches) at Stated Time Intervals The built and unbuilt compositions of the invention provide suds heights within the desired sudsing height ranges. The unfractionated coconut soap gave unfavorable sudsing profiles in combination with an alkyl ether sulfate of the invention. The suds height was low initially and during the course of the evaluation.

The following Examples are illustrative of the present invention, but it will be understood that the invention is not in any way limited thereto.

EXAMPLE V Sodium salt of coconut alkyl ether sulfate (obtained from the condensate of 2 moles ethylene oxide per mole of alcohol) 20.0% Sodium tetradecanoate 2.0 Sodium cumene sulfonate 8.0 Water 70.0

This composition is a sudsing liquid cleaner which provides excellent performance results on hard surfaces such as walls, floors, ceilings and the like.

EXAMPLE VI Sodium salt of coconut alkyl ether sulfate (obtained from the condensate of 3 moles ethylene oxide per mole of alcohol) Sodium tetradecanoate Tetra-potassium pyrophosphate Sodium carbonate/sodium bicarbonate Sodium cumene sulfonate Water 7 This composition is an economical liquid cleaner offering excellent performance when used at a recommended usage level of one-fourth cup per gallon of water. In such a washing solution the composition has a pH in the range of about 10 to 11.

EXAMPLE VII Sodium salt of tallow alkyl ether sulfate (obtained from the condensate of 4 moles ethylene oxide per mole of alcohol) 2.0% Sodium tetradecanoate 1.0 Tri-sodium salt of nitriloacetic acid 12.0 Sodium carbonate/sodium bicarbonate 2.5 Sodium cumene sulfonate 8.0 Water 74.5

This is a sudsing liquid cleaner composition with superior performance properties when used at a recommended usage of one-fourth cup per gallon in an aqueous solution having a pH in the range of 10 to 1!.

EXAMPLE VIII Sodium salt of coconut alkyl ether sulfate (obtained from the condensate of 3 moles ethylene oxide per mole of alcohol) 14.0% Sodium dodecanoate 1.5 Potassium toluene sulfonate 6.0 Water 78.5

This composition is a controlled sudsing liquid cleaner which provides superior cleaning performance at recommended usage levels in the range of one-eighth cup per gallon to about three-eighths cup per gallon of LII water. The washing solution has a pH in the to 11.

range of 7 EXAMPLE IX Sodium salt of tallow alkyl ether sulfate (obtained from the condensate of 4 moles ethylene oxide per mole of alcohol Sodium dodecanoate Pentasodium tripolyphosphate Sodium carbonate/sodium bicarbonate Potassium toluene sulfonate Water This composition is a medium sudsing liquid cleaner having a pH of about 10 and which gives superior performance characteristics when used according to rec-' wherein R is alkyl of from 10 to 16 carbons, x has an average value of .from 2 to 4 and M is a watersolubilizing cation selected from the group consisting of alkali metal, ammonium, and substituted ammonium; and from 0.5% to 5% of an alkali metal soap selected from the group consisting of alkali metal soaps containing 12 carbon atoms, alkali metal soaps containing 14 carbon atoms, mixtures of alkali metal soaps, said mixtures containing at least 92% of a soap containing 14 carbon atoms, and mixtures of alkali metal soaps, said mixtures containing at least 93% of a soap containing 12 carbon atoms; and the balance water; said alkyl ether sulfate and alkali metal soap being in the ratio of from 1:1 to 30:1.

2. The composition of claim 1 wherein the alkyl ether sulfate and alkali metal soap comprise from 3% to 20% of the composition.

3. The composition of claim 2 wherein the alkali metal is sodium.

4. The composition of claim 3 wherein x has an average value of 3.

5. The composition of claim 4 having a water-soluble builder salt the ratio of alkyl ethersulfate and soap to builder being from 1:1 to about 1:10.

6. The composition of claim 5 containing additionally from 1% to 12% by weight of the composition of a hydrotrope, said hydrotrope being selected from the group consisting of sodium toluene sulfonate, sodium cumene sulfonate or sodium xylene sulfonate.

7. The composition of claim 6 wherein the water is 60% to by weight of the composition.

Claims

2. The composition of claim 1 wherein the alkyl ether sulfate and alkali metal soap comprise from 3% to 20% of the composition.
3. The composition of claim 2 wherein the alkali metal is sodium.
4. The composition of claim 3 wherein x has an average value of 3.
5. The composition of claim 4 having a water-soluble builder salt the ratio of alkyl ethersulfate and soap to builder being from 1:1 to about 1:10.
6. The composition of claim 5 containing additionally from 1% to 12% by weight of the composition of a hydrotrope, said hydrotrope being selected from the group consisting of sodium toluene sulfonate, sodium cumene sulfonate or sodium xylene sulfonate.
7. The composition of claim 6 wherein the water is 60% to 80% by weight of the composition.