AMINE OXIDE/AMIDE FOAM STABILIZER SYSTEM

Abstract: A process for stabilizing foam produced by a liquid cleaning composition comprising adding to the liquid cleaning composition from about 1 to about 10 % by weight, based on the weight of the liquid cleaning composition, of a foam stabilizing composition consisting essentially of: (a) an amine oxide having general formula (I), wherein, R<1> is an alkyl or alkenyl radical having from about 7 to about 18 carbon atoms, and R<2> and R<3> are individually alkyl or hydroxyalkyl radicals having from about 1 to about 4 carbon atoms; and (b) an amide having general formula (II), wherein R3 is an alkyl group containing from about 8 to about 18 carbon atoms and each R4 is the same or different and is selected from the group consisting of hydrogen, C1-3 alkyl, C1-3 alkynol, and -(C2H4O-), and mixtures thereof, wherein components (a and b) are combined in an actives ratio of about 1:1.

Description: AMINE OXIDE/AMIDE FOAM STABILIZER SYSTEM Field of the Invention: The present invention generally relates to a novel foam stabilizer composition. More particularly, the present invention relates to the unexpected discovery that by combining an amine oxide with an amide in a 1:1 actives ratio, an effective foam stabilizer is formed which is equally as effective but significantly less expensive than known individual foam stabilizer compounds. Background of the Invention: It is known that various surfactants have been found to be useful in cleaning compositions, such as shower gels, shampoos, and light duty detergents such as dish washing detergents. In these types of compositions, good foamability is a prerequisite. The most widely used surfactants in these types of compositions are anionic surfactants such as alkyl sulfates, alkyl ether sulfates, sulfonates, sulfosuccinates and sarcosinates. Although the use of anionic surfactants in these compositions permits the attainment of desirable properties, including good foamability, the degree of foam stability leaves much to be desired. Foam stability relates to the ability of the foam, once formed, to remain intact for extended periods of time, thus enhancing the cleaning performance of the surfactant compositions. The use of amine oxides, by themselves, as foam stabilizers in cleaning compositions is known in the art. However, because amine oxides are expensive compounds, their use as foam stabilizers results in a measurable increase in the cost of the cleaning composition to consumers. Moreover, while manufacturers have attempted to employ less expensive foam stabilizers in their cleaning compositions for cost-reduction purposes, the less expensive foam stabilizers have proven to be less effective than their amine oxide counterparts. Summary of the Invention: The present invention is directed to a novel foam stabilizing agent consisting essentially of: (a) an amine oxide having general formula I: wherein R 1 is an alkyl or alkenyl radical having from about 7 to about 18 carbon atoms, and R 2 and R 3 are individually alkyl or hydroxyalkyl radicals having from about l to about 4 carbon atoms; and (b) an amide having general formula II: 0 II R 1 -C-N-(R 2 ) 2 (II) wherein R 1 is an alkyl group containing from about 8 to about 18 carbon atoms and each R j is the same or different and is selected from the group consisting of hydrogen, C^_ z alkyl, C._ 3 alkanol, and -(C 2 H 4 0-) , and mixtures thereof, wherein components (a) and (b) are combined in an actives ratio of about 1:1. The present invention is also directed to a cleaning composition containing from about 1 to about 10% by weight, based on the weight of the cleaning composition, of the above-disclosed novel foam stabilizing agent. The present invention is also directed to a process for stabilizing foam produced by a cleaning composition involving adding to the cleaning composition from about 1 to about 10% by weight, based on the weight of the cleaning composition, of the above-disclosed foam stabilizing agent. Description of the Invention: Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions used herein are to be understood as being modified in all instances by the term "about". As was noted above, it was surprisingly found that by combining an amine oxide with an amide in an actives ratio of about 1:1, a foam stabilizing agent is formed which, compared to amine oxides when used alone, is less expensive and equally as effective at stabilizing foam. The amine oxides which may be employed in the present invention are of general formula I: wherein R 1 is an alkyl or alkenyl radical having from about 7 to about 18 carbon atoms, and R 2 and R 3 are individually alkyl or hydroxyalkyl radicals having from about 1 to about 4 carbon atoms. Examples of amine oxides which may be used in the present invention include, but are not limited to lauryl amine oxide, cocamine oxide, cocamidopropyl amine oxide, lauryl amido propyl amine oxide. A particularly preferred amine oxide is lauryl amine oxide, commercially available from The Mclntyre Group Ltd. under the tradename MACKAMINE® LO. It should also be noted that tertiary amine oxides, wherein the radical RCO represents a coconut acid or lauric acid radical, may also be used. The amides which may be employed in the present invention have the general formula II: O R 1 -C-N-(R 2 ) 2 (II) wherein R 1 is an alkyl group containing from about 8 to about 18 carbon atoms and each R j is the same or different and is selected from the group consisting of hydrogen, C^_ z alkyl, C^-. alkanol, and -(C 2 H A 0-), and mixtures thereof. Examples of amides suitable for use in the present invention include, but are not limited to, monoethanolamides , diethanolamides, and 2:1 kritchevsky amides. A particularly preferred amide for use in the present invention is cocadiethanolamide, commercially available from Henkel Corporation, Ambler, PA, under the tradename STANDAMID® SD. The preferred amides employed in the present invention are characterized by being a mixture of ethanolamides of lauric, myristic and/or coconut acid radicals. The most effective are those having long-chain, sparingly soluble, polar compounds with straight-chain hydrocarbon groups of approximately equal length to the hydrophobic groups of the surfactant. As was noted previously, amine oxides are known foam stabilizers which, while effective, are costly to use. However, the cost of using them can be significantly reduced and their foam stability effectiveness retained by combining them with an amide in an actives ratio of about 1:1. Thus, according to one aspect of the present invention, there is provided a foam stabilizing composition consisting essentially of a combination of an amine oxide, and preferably a cocadimethyl amine oxide and an amide, preferably a cocadiethanolamide, wherein the amine oxide and amide are combined in an actives ratio of about 1:1. According to another aspect of the invention, there is also provided a process for stabilizing foam produced by a liquid cleaning composition involving adding to the liquid cleaning composition from about 1 to about 10% by weight, based on the weight of the liquid cleaning composition, of the above-disclosed foam stabilizing composition. In a particularly preferred embodiment, from about 2 to about 5% by weight of the foam stabilizing composition is added to the liquid cleaning composition. In yet another embodiment of the present invention, there is also provided a liquid cleaning composition having improved foam stabilizing properties. Liquid cleaning compositions such as shower gels, shampoos, and light duty detergents such as dish washing detergents, contain ingredients such as, for example, surfactants, whether anionic, nonionic or both, thickeners, pH regulators, colorants, pearlizing agents, clarifying agents, fragrances, preservatives, antioxidants, chelating agents, skin and hair conditioners, botanical extracts, and antibacterial agents. It has been surprisingly found, however, that the foam generated by these types of liquid cleaning compositions can be effectively stabilized by incorporating, into the liquid cleaning composition, the above-disclosed foam stabilizing composition, which is less expensive to use than known foam stabilizing agents such as amine oxides used by themselves. According to this aspect of the invention, the liquid cleaning composition contains from about 1 to about 10% by weight, and preferably from about 2 to about 5% by weight, based on the weight of the liquid cleaning composition, of the above-disclosed foam stabilizing composition. The present invention will be better understood from the examples which follow, all of which are intended to be illustrative only and not meant to unduly limit the scope of the invention. Unless otherwise indicated, percentages are on a 100% actives basis. EXAMPLES A number of foam stabilizer systems were formulated, in accordance with the present invention, and tested for foam stability. Foam stability performance was evaluated using the Modified Shell Terg-o-tometer test which involved adding 0.5 gram pellets of a soil consisting of Crisco, potato, milk and olive oil, every 30 seconds, to 400 ml of each test solution in diluted form, in a tergotometer. Foam was generated by agitation of each solution for two minutes at 125 rpm. The speed was then reduced to 50 rpm for the duration of the test, which ended at the point when there was no more foam. The results thereof, found in Table I, represent the number of 0.5 gram pellets of soil required to achieve a no foam endpoint. The more 0.5 gram pellets required, the better the foam stability of the test solution. The formulations and results thereof are found in Table 1 below. Table 1 As can be seen from the results above, by combining an amide with an amine oxide, in a 1:1 actives ratio, enhanced foam stability results are realized, as compared to known individual foam stabilizers. Additional test solutions were also prepared and tested, their formulations and test results thereof being found in Table 2, below. Table 2

Claims: What is claimed is: 1. A process for stabilizing foam produced by a liquid cleaning composition comprising adding to the liquid cleaning composition from about 1 to about 10% by weight, based on the weight of the liquid cleaning composition, of a foam stabilizing composition consisting essentially of: (a) an amine oxide having general formula I: R 2 I . R'-N-→O (I) A. wherein R 1 is an alkyl or alkenyl radical having from about 7 to about 18 carbon atoms, and R 2 and R 3 are individually alkyl or hydroxyalkyl radicals having from about 1 to about 4 carbon atoms; and (b) an amide having general formula II: wherein R j is an alkyl group containing from about 8 to about 18 carbon atoms and each R 4 is the same or different and is selected from the group consisting of hydrogen, C,^ alkyl, C^ alkanol, and -(C 2 H 4 0-) , and mixtures thereof, wherein components (a) and (b) are combined in an actives ratio of about 1:1. 2. The process of claim 1 wherein the amine oxide is lauryl dimethyl amine oxide. 3. The process of claim 1 wherein the amide is cocadiethanolamide. 4. The process of claim 1 wherein from about 2 to about 5% by weight, based on the weight of the liquid cleaning composition, of the foam stabilizing composition is added to the liquid cleaning composition. 5. The process of claim 1 wherein the liquid cleaning composition further contains an ingredient selected from the group consisting of a surfactant, a thickener, a pH regulator, a colorant, a pearlizing agent, a clarifying agent, a fragrance, a preservative, an antioxidant, a chelating agent, a skin conditioner, a hair conditioner, a botanical extract, an antibacterial agent, and mixtures thereof . 6. The process of claim 1 wherein the liquid cleaning composition is selected from the group consisting of a shower gel, a shampoo, and a dish washing detergent. 7. A foam stabilizing composition consisting essentially of: (a) an amine oxide having general formula I: wherein R 1 is an alkyl or alkenyl radical having from about 7 to about 18 carbon atoms, and R 2 and R 3 are individually alkyl or hydroxyalkyl radicals having from about l to about 4 carbon atoms; and (b) an amide having general formula II: wherein R 3 is an alkyl group containing from about 8 to about 18 carbon atoms and each R 4 is the same or different and is selected from the group consisting of hydrogen, C^. z alkyl, C^ alkanol, and -(C 2 H 4 0-), and mixtures thereof, wherein components (a) and (b) are combined in an actives ratio of about 1:1. 8. The composition of claim 7 wherein the amine oxide is lauryl dimethyl amine oxide. 9. The composition of claim 7 wherein the amide is cocadiethanolamide. 10. A liquid cleaning composition having enhanced foam stability comprising from about 1 to about 10% by weight, based on the weight of the liquid cleaning composition, of a foam stabilizing composition consisting essentially of: (a) an amine oxide having general formula I: wherein R 1 is an alkyl or alkenyl radical having from about 7 to about 18 carbon atoms, and R 2 and R 3 are individually alkyl or hydroxyalkyl radicals having from about 1 to about 4 carbon atoms; and (b) an amide having general formula II: wherein R j is an alkyl group containing from about 8 to about 18 carbon atoms and each R 4 is the same or different and is selected from the group consisting of hydrogen, C^_ z alkyl, C^ j alkanol, and -(C 2 H 4 0-) , and mixtures thereof, wherein components (a) and (b) are combined in an actives ratio of about 1:1. 11. The composition of claim 10 wherein the amine oxide is lauryl dimethyl amine oxide. 12. The composition of claim 10 wherein the amide is cocadiethanolamide. 13. The composition of claim 10 wherein from about 2 to about 5% by weight, based on the weight of the liquid cleaning composition, of the foam stabilizing composition is added to the liquid cleaning composition. 14. The composition of claim 10 wherein the liquid cleaning composition further contains an ingredient selected from the group consisting of a surfactant, a thickener, a pH regulator, a colorant, a pearlizing agent, a clarifying agent, a fragrance, a preservative, an antioxidant, a chelating agent, a skin conditioner, a hair conditioner, a botanical extract, an antibacterial agent, and mixtures thereof. 15. The composition of claim 10 wherein the liquid cleaning composition is selected from the group consisting of a shower gel, a shampoo, and a dish washing detergent.

Inventors: LAZAROWITZ VIRGINIA L, LAZAROWITZ, VIRGINIA, L.
Applicants: HENKEL CORP, HENKEL CORPORATION
Application year: 1998
Main classification: C11D1
IPC codes: C11D1, C11D3