US3179599A - Detergent composition - Google Patents

Abstract

An aqueous detergent composition comprises, by weight, (a) 18-40% R(OC2H4)xSO4M, wherein x is 0-4; (b) a trialkyl amine oxide, the weight ratio (a); (b) being 1-7: 1; (c) 1.8-10%, but at least 20% by weight of (b), alkyl glyceryl ether sulphonate; and (d) at least 5%, but preferably not more than 40% of methanol, ethanol, n- or iso-propanol, or mixtures thereof. (a), (b) and (c) each contain a C10-14-straight chain alkyl group of which at least 50% contains 12 carbon atoms; (b) contains two alkyl groups which each have 1 or 2 carbon atoms, and the cation in (a) and (c) is mono-, di- or tri-ethanolamine, ammonium, sodium, or potassium. (a) is preferably the ammonium salt of the sulphated condensate of 3 mols. ethylene oxide with 1 mol. middle cut coconut alcohol, and the weight ratio of (b) to (c) is usually at least 1:1. Up to 5% of sodium, potassium or ammonium toluene or xylene sulphonates, or mixtures thereof may be present. Inorganic salts in amounts up to 12%, e.g. sodium nitrate, potassium chloride, or ammonium phosphate, opacifiers such as ethylene glycol distearate or polystyrene in amounts up to 3%, citric acid, perfume, viscosity control agents, colour and perfume may also be incorporated. Specifications 802,325 and 992,754 are referred to.

Description

United States PatentOfiFice l 3,179,599 Patented Apr. 21), 1965 3,179,599 DETERGENT COMPOSETION Stanley Lee Eaton and Edmund Frederick Gebhardt, Cineinnnati, Ohio, assignors to The Procter dz Gamble (Iompany, Qincinnati, Ohio, a corporation of Ohio No Drawing. Filed July 3, 1961, Ser. No. 121,341 3 Claims. (til. 252-153) by the amount of suds present and will very likely be misled if the suds do not persist for a reasonable period of time.

There are many dificulties associated with formulating a high-sudsing, light-duty liquid detergent. An ideal liquid detergent composition is clear and colorless, permitting the formulation of a Wide variety of opaque,

clear, colorless and colored detergents. However, the

most common suds builders are amides, which tend to color the product yellow. An ideal liquid detergent is also one where the major ingredients are highly compatible so that only a minimum amount of solubilizing agent is needed to keep the detergent in a single phase, yet many detergent surface active agents and suds builders are not unlimitedly soluble in water, especially in combination with each other. Furthermore, the ideal liquid detergent would be suitable for use with all kinds of soil and wash water, including acid soil and wash Water.

Accordingly, it is an object of this invention to provide a high-sudsing, light-duty liquid detergent which maintains as much as possible its sudsing performance under acid conditions.

It is a still further object of this invention to provide a highsudsing, light-duty liquid detergent which does not contain an amide type suds builder.

It is another object of this invention to provide a singlephase, high-sudsing, light-duty liquid detergent requiring only a relatively small amount of a solubilizing agent.

The unbuilt, high-sudsing, light-duty liquid detergent compositions of this invention consist essentially of: (1) from about 20% to about 40% by weight of the composition of a sulfate detergent surfactant having the following formula .having 12 carbon atoms and two short chain alkyl groups having from one to about two carbon atoms in an amount such that the weight ratio of sulfate detergent surfactant to amine oxide is from about 1/1 to about 7/1; (3) from about 2% to about 10% by Weight of the composition of an alkyl glyceryl ether sulfonate having a straight chain alkyl group having from about 10 to about 14 carbon atoms with at least 50% of said alkyl groups having 12 carbon atoms, the cation of said sulfonate being selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, ammonium, sodium and potassium cations and mixtures thereof, the amount of said sulfonate being at least 20% of the amount of said amine oxide; (4) at least about 5% by Weight of the composition of a solubilizing agent selected from the group consisting of methyl, ethyl, n-propy1, and isopropyl alcohols; and (5) the balance water. Other minor ingredients including from zero to about 5% by Weight of the composition of a viscosity control agent such as either potassium, sodium, or ammonium toluene sulfonate or potassium, sodium or ammonium xylene sulfonate; perfume; opacifiers; and coloring can be added.

It has been discovered that the amine oxides of this invention build (enhance) the sudsing ability of the sulfates of this invention to a high degree, but do not build the sudsing ability of the sulfonates, or sulfate surfactants containing aromatic configurations to the extent desired in light duty detergents having a pH in the range of 6.5 to 9.0. As used herein, sudsing ability refers to both the initial quantity of suds and the persistence of the suds throughout the Washing operation. The persistence (stability) of the suds of the composition of this invention is extremely good under alkaline, neutral, and acidic conditions. It has also been discovered (as set forth in the copending application of Norman R.

Smith, Serial No. 121,340, filed concurrently herewith) that unless the weight ratio of sulfate surfactant to amine oxide is at least 3/ 1, the sudsing ability of the composition is practically eliminated under acid conditions such as might exist where the pH of the wash Water Was less than about 6.5. This may occur Where the Water itself is acid or where the. soil on the objects to be washed isacid. On the other hand, compositions with Weight ratios of sulfate surfactant to amine oxide greater than 7/1 lose sudsing ability both in acid and neutral wash Water.

This sudsing sensitivity of combinations of sulfate surfactant and amine oxide to acid conditions can be controlled very satisfactorily by the inclusion in the composition of from about 2% to about 10% by weight of the composition of a monoethanolamine, diethanolarnine, triethanolamine, sodium, potassium, or ammonium alkyl glyceryl ether sulfonate as hereinbefore described. The addition of this sulfonate permits the usage of sulfate surfactant to amine oxide ratios of from about 1/1 about 7/ 1. The sulfonate not only permits the use of sulfate surfactant to amine oxide ratios of less than 3/1 under acid conditions, it also increases sudsing performance for almost all ratios of sulfate surfactant to amine oxide within the broad range hereinbefore mentioned. This is a very surprising result since a composition containing only the alkyl glyceryl ether sulfonate and amine oxide in an unbuilt product, does not perform as satisfactorily as the sulfate alone as far as sudsing ability is concerned under either acidic or neutral conditions. Only in ternary mixtures as hereinbefore described, do the alkyl glyceryl ether sulfonates of this invention have a synergistic effect upon sudsing ability.

As a general rule, weight ratios of sulfate surfactant to amine oxide of less than l/l are preferably not used from the standpoint of mildness, and there is a loss in sudsing performance with ratios above 7/1, even with the inclusion of the sulfonates of this invention.

The loss of sudsing ability under acid conditions is ordinarilymanifested only in unbuilt detergents. Whereas the pH of a liquid detergent built with substantial quantities of ordinary phosphate builders and/ or silicate salts and/ or other alkaline builders is around 10 or above, the pH of the unbuilt liquid detergents of this invention and of unbuilt liquid detergents in general is about 6.5 to 9.0 In addition to this initial alkalinity in built liquids, the builder provides a reservoir of alkalinity so that there taining these groups.

must be a considerable amount of acidic material present in the wash water before the pH will be lowered to a 'level Where substantial loss of sudsing ability is encountered with detergent sulfate to amine oxide weight ratios outside the scope of this invention. However, when only a relatively small amount of acidic material is present in the wash water and/ or soil, the addition of unbuilt liquid detergents to the Wash water will, in general, leave the wash water with an acid pH.

As hereinbefore mentioned, the sulfonate should be present in an amount equal to at least about by Weight of the amount of amine oxide present. This amount is required to give satisfactory sudsing performance under acid conditions. From an economic standpoint, the ratio of amine oxide to alkyl glyceryl ether sulfonate should not be less than about 1/1 since an increase in the amount of sulfonate above the amount represented by this ratio does not give appreciably better performance.

The concentration range of sulfate detergent surfactant is set at the lower limit of 20% by sudsing considerations and at the upper limit of by viscosity considerations.

At lower levels the quantity of suds is drastically reduced and at hi her levels the product is no longer pourable.

The sulfate detergent surfactant itself has certain requirements as to the length of the alkyl chain. Chain lengths of less than ten carbon atoms give reduced detergency and sudsing and chain lengths greater than 14 reduce the quantity of suds which are produced. Somewhat the same considerations apply also to the chain length of the long alkyl group in the amine oxide surfactant.

Shorter chain lengths lead to decreased detergency, sudsing, and suds building as do longer chain lengths. The

the amine oxide for the same reasons of sudsing and detergency mentioned above since this is the optimum chain length.

' The length of the short alkyl groups in the amine oxide is set by considerations of solubility. Groups which are longer than about two carbon atoms inhibit the solubility of the amine oxide in the water.

A sulfate detergent surfactant containing no ethylene oxide groups is an effective detergent and sudser, but is not quite as mild as a sulfate detergent surfactant con- However, more than about four ethylene oxide groups in the molecule will substantially reduce sudsing capacity. The preferred sulfate detergent surfactant contains an average of three ethylene oxide groups per molecule. In general, all of the compositions of this invention are mild when applied to human skin.

Preferred alkyl glyceryl ether sulfonates are described in Canadian Patent 582,404.

The finished composition requires'the addition of a solubilizing agent to prevent phase separation. Although much less solubilizer is needed when an amide is not present, still at least about 5% of the solubilizing agent is necessary. Too much solubilizing agent would be too costly and tends to adversely affect viscosity, so that only enough solubilizing'agent should be included in the composition to keep the composition in a pourable single phase under conditions of use, but not more than about 40% by weight of the composition.

As hereinbefore mentioned, various minor ingredients including perfume, viscosity control agents, opacifiers, and

The toluene sulfonates and xylene suhonates hereinbefore described are desirable minor additives in amounts up to 5%. They increase the viscosity of the compositions. Other desirable additives include opacifiers such as ethylene glycol distearate or polystyrene in amounts up to about 3% by weight of the compositions.

The compositions of this invention do not contain conventional suds builders such as amides. The superior sudsing ability of these compositions makes it unnecessary to have such suds builders present, which results in cost advantages and simplified formulation. Also, since the most common suds builders are amides, which have odors and which color the product, the compositions of this invention have better odor and better color than many prior high sudsing compositions. Amides also tend to cause phase instability which can only be'corrected by adding much more solubilizing agent than is ordinarily required in compositions of this invention.

The following examples will demonstrate the unique advantages of the compositions of this invention as op tion.

Example I The following compositions contained varying amounts of the ammonium salt of the sulfated condensation product of one mole of middle-cut coconut alcohol containmg 1t 12, 14; and 9%C16 alkyl groups with three moles of ethylene oxide (A), a tertiary amine oxide having a long alkyl chain derived from the same middle-out coconut alcohol and two methyl groups (B), and sodium alkyl glyceryl ether sulfonate wherein the alkyl group is derived from the same middle-cut coconut alcohol (C). The compositions also contained 10% ethyl alcohol and the balance water. All percentages contained herein are by weight of the composition.

In order to evaluate the sudsing ability of these compositions, 7.25 cc. of each of the compositions was added to a dishpan containing one gallon of water with a hardness of 7 grains, a temperature of F., and pHs of 7 and 5 for two separate trials. Suds were generated by mechanical agitation (small propeller) and the suds level measured. A fixed quantity (about 5 grams) of standardized fatty soil (2. triglyceride shortening) was placed on a dinner plate which was then washed in the test solution. The plate was re-soiled and washed, repeating this procedure a total of five times. Five additional sets of five soiled plates were washed in the solution in like manner, measuring the foam height after each set. The foam height after washing each set was expressed in terms -of percent of original suds height and an average of the Composition 1 2 3 4 5 6 7 8 9 10 Percent A 25 25 25 25 25 20 20 20 20 20 Percent B 5 5 5 5 5 5 5 5 5 5 Percent C 0 1 2 3 4 0 1 2 3 4 Percent Ethyl alcohoL 10 10 10 10 10 10 1O 10 10 10 Percent Water bal. bal. bal. bal. bal. bal. bal. bal. bal. bal. Ratio A/B 5 5 5 5 5 4 4 4 4 4 Performance at pH 7 49 5O 53 53 54 44 44 44 45 48 Performance at pH 5..." 35 43 5O 50 51 29 31 36 38 36 Composition 11 12 13 14 15 16 17 18 19 20 PercentA 15 15 15 15 15 20 20 20 25 25 Percent B- 15 15 15 15 15 1O 10 10 10 10 Percent O 0 4 6 8 10 0 4 5 O 2 Percent Ethyl alcohol 10 10 10 10 10 10 10 10 10 10 Percent Water bal. bal. bal. bal. bal. bal. bal. bal. bal. bal. Performance at pH 47 45 38 4O 45 39 41 43 48 48 Performance at pH 5 35 38 41 43 37 32 32 1 Sudsing was too low to measure by this test method.

As can be seen from the preceding data, compositions with weight ratios of sulfate detergent surfactant to amine oxide of more than 3/1 (Compositions 1-10) all have acceptable sudsing performance. However, compositions without sodium alkyl glyceryl ether sulfonate (Compositions 1 and 6) did not perform as well relative to sudsing as those compositions containing sulfonate (Compositions 2-5 and 7-10).

As can also be seen from the preceding data, compositions with a weight ratio of sulfate detergent surfactant to amine oxide of less than 3/1 (Compositions 11-20) did not perform well at all under acid conditions when there was no sulfonate present (Compositions 11, 16 and 19), but performed exceptionally when there was even a small amount of sulfonate present (Compositions 12- 14, 17, 18, and 20).

Therefore, it is readily apparent that the addition of an alkyl glyceryl ether sufonate of this invention to a combination of the sulfates and amine oxides of this invention gives exceptionally good results.

Example ll A detergent composition was prepared containing 25% by weight of the composition of the sulfate detergent surfactant of Example I, 5% by weight of the composition of the amine oxide of Example I, 2% by weight of the composition of the alkyl glyceryl ether sulfonated of Example I, 1% by weight of the composition of ammcnium phosphate, 12% by weight of the composition of ethyl alcohol, 0.3% by weight of the composition of perfume, 0.2% by weight of the composition of a 1% by weight color solution, 0.1% by weight of the composition of citric acid, and the balance water. This composition was tested under typical home use conditions and found to be a very satisfactory high-sudsing, light-duty liquid detergent under alkaline, neutral, and acidic conditions. The ammonium phosphate present in this and subsequent examples is present only in small amounts for the purpose of adjusting the pH of the product and is not present. as a builder.

When the sulfate and sulfonate detergent surfactants in the preceding example are the monoethanolamine, diethanolamine, triethanolamine, or potassium salts, substantially equivalent results are achieved.

Similarly, when the ethyl alcohol solubilizing agent is replaced by methyl, isopropyl, or normal propyl alcohols, substantially equivalent results are achieved.

Also when ammonium and sodium exylene sulfonates and sodium and ammonium toluene sulfonates are added to the composition of the above example of the composition, substantially equivalent results are achieved.

Example 111 A detergent composition was prepared containing 25% of the sulface detergent surfactant of Example I, 5% of the amine oxide of Example I, 4% sodium alkyl glyceryl ether sulfonate wherein the alkyl group is derived from the same middle-cut coconut alcohol as the sulfate, 2% potassium toluene sulfonate 6% ethyl alcohol, 2% potassium chloride, 1% ethylene glycol distearate, 0.1% critic acid, 0.15% perfume, 0.09% brightener, and the balance water. All percentages herein are by weight of the composition. The composition was tested under home use conditions and found to be an effective highsudsing, light-duty liquid detergent under alkaline, neutral and acidic conditions.

Example IV A detergent composition was prepared containing 25 of the sodium salt of the sulfated condensation product of one mole of middle-cut coconut alcohol, as hereinbefore described, and three moles of ethylene oxide; 6% lauryl dimethyl amine oxide; 4% sodium alkyl glyceryl ether sulfonate wherein the alkyl group is derived from middle-cut coconut alcohol as hereinbefore described; 3% sodium alkyl glyceryl ether sulfonate wherein the alkyl group was derived from tallow; 12% sodium nitrate; 8% ethyl alcohol; 2% sodium toluenesulfonate; 0.15% perfume; and the balance water and miscellaneous inert in- Example V A detergent composition was prepared containing 21% of the sulfate detergent surfactant of Example I, 4% of the amine oxide of Example I, 2% of the alkyl glyceryl ether sulfonate of Example I, 1% ammonium phosphate, 0.1% citric acid; 0.3% perfume, 12% ethyl alcohol, 0.2% of a 1% by weight color solution, and the balance water and miscellaneous inert ingredients. All percentages herein are by weight of the composition. This composition was tested by the test of Example I and found to have a performance at pH 7 of 44 and a performance at pH 5 of 35. This was an exceptionally good sudsing lightduty liquid detergent.

What is claimed is:

1. An unbuilt, high-sudsing, light-duty liquid detergent composition having a pH of from about 6.5 to 9.0 and having special utility under acid conditions such as might exist where the pH of the wash water is less than about 6.5 and consisting essentially of (1) from about 20% to about 40% by weight of the composition of a sulfate detergent having the following formula wherein R is a straight chain alkyl group having from about 10 to about 14 carbon atoms with at least 50% of said alkyl groups having 12 carbon atoms, x is a number from zero to about four, and Me is selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, ammonium, sodium, and potassium cations; (2) a trialkyl amine oxide having one straight chain alkyl group having from about 10' to about 14 carbon atoms, with at least 50% of said alkyl groups having 12 carbon atoms, and two short chain alkyl groups having from one to about two carbon atoms, in an amount suflicient to give a ratio of sulfate detergent to amine oxide of from about 1/1 to about 7/1; (3) from about 2% to about 10% by weight of the composition of an alkyl glyceryl ether sulfonate having a straight chain alkyl group having from about 10 to about 14 carbon atoms with at least 50% of the said alkyl groups having 12. carbon atoms, the cation of said sulfonate being selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, ammonium, sodium, and potassium cations and mixtures thereof, the amount of said sulfonate being at least 20% of the amount of said amine oxide; (4) at least about 5% but not more than about 40% by weight of the composition of a solubilizing agent selected from the group consisting of methyl, ethyl, n-propyl, and isopropyl alcohols, and mixtures thereof; and (5) the balance water.

2. The composition of claim 1 containing from zero to about five percent of material selected from the group consisting of sodium, potassium, and ammonium toluene sulfonates; sodium, potassium, and ammonium xylene sulfonates; and mixtures thereof.

3. The composition of claim 1 wherein the sulfate detergent is the ammonium salt of the sulfate of the condensation product of one mole of middle-cut coconut alcohol and an average of three moles of ethylene oxide.

(References on following page) Cited by 1111: Examiner 2,877,185 3/59 Krumrei et a1 252-137 2,999,068 9/61 Pilcher et a1 252-152 XR UNITED STATES PATENTS 2,060,568 11/36 Graenacher et a1. 2s2 -152 XR 3001945 9/61 Drew et 252 152 2,169,976 8/39 Guenther et a] 252-152 XR 5 FOREIGN PATENTS 2,310,074 2/43 Gotte 854 206,622 3/57 Australia.

2,607,740 8/52 Vitale et a1 252153 2,861,956 11/58 Fernandez 252-153 JULIUS GREENWALD, Primary Examiner.

Claims (1)

1. AN UNBUILT, HIGH-SUDSIN, LIGHT-DUTY LIQUID DETERGENT COMPOSTION HAVING A PH OF FROM ABOUT 6.5 TO 9.0 AND HAVING SPECIAL UTILITY UNDER ACID CONDITIONS SUCH AS MIGHT EXIST WHERE THE PH OF THE WASH WATER IS LESS THAN ABOUT 6.5 AND CONSISTING ESSENTIALLY OF (1) FROM ABOUT 20% TO ABOUT 40% BY WEIGHT OF THE COMPOSITION OF A SULFATE DETERGENT HAVING THE FOLLOWING FORMULA