THE USE OF ALKOXYLATED ALCOHOLS TO CONTROL FOAMING OF ALKYL POLYGLYCOSIDES IN CLEANING COMPOSITIONS

Abstract: A process for reducing foam in an alkyl polyglycoside-containing cleaning composition by adding a defoaming-effective amount of an alkoxylated alcohol having the general formula (I): R1(EO)x(PO)y-OH, wherein R1 is derived from a linear or branched alkyl chain having from about 8 to about 14 carbon atoms; x is a number having a value of from 1 to about 10; y is a number having a value of from 1 to about 10, to a composition containing an alkyl polyglycoside having the general formula (II): R3O(R4O)b(Z)a, wherein R3 is a monovalent organic radical having from about 6 to about 30 carbon atoms; R4 is divalent alkylene radical having from 2 to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms; b is a number having a value from 0 to about 12; a is a number having a value from 1 to about 6.

Description: TheUseofAlkoxylatedAlcoholsToControl Foaming ofAlkyl Polyglycosides inCleaning Compositions Field of the Invention The invention relates to the use of alkoxylated alcohols to control foaming in alkyl polyglycoside- containing compositions. Background of the Invention It is known that alkyl polyglycosides exhibit significantly higher foaming profiles than other nonionic surfactants, such as alcohol ethoxylates. In fact, it can be said that the foaming tendencies of alkyl polyglycosides more closely resemble those of anionic surfactants, such as alcohol sulfates, than the foaming tendencies of other nonionic surfactants. This higher foaming tendency makes the use of alkyl polyglycosides undesirable for many applications, e.g. cleaning-in-place for food processing plants, high pressure spray cleaning, bottle washing, floor cleaners and automatic dishwashing, wherein high levels of foa interfere with the cleaning and rinsing operation and reduce the efficiency of the operation. Low foam nonionics, such as EO/PO block copolymers, can be used to reduce the foaming properties of alkyl undesirable properties, e.g. low biodegradability, relatively high aquatic toxicity and poor caustic compatibility. Accordingly, there is a need for the development of methods for decreasing the foaming tendency of alkyl polyglycoside containing compositions without simultaneously affecting the beneficial properties of the alkyl polyglycosides, e.g. good cleaning ability, high biodegradability, low aquatic toxicity and good caustic compatibility. Summary of the Invention It has now surprisingly been found that by adding an affective amount of an alkoxylated alcohol corresponding to general formula I: R 1 (EO) x (PO) y -OH I wherein R-- is derived from a linear or branched alkyl chain having from about 8 to about 14 carbon atoms; x is a number having a value of from 1 to about 10; y is a number having a value of from 1 to about 10, to a cleaning composition containing an alkyl polyglycoside having the general formula II: R 3 0(R 4 0) b (Z) a II wherein R 3 is a monovalent organic radical having from about 6 to about 30 carbon atoms; R 4 is divalent alkylene radical having from 2 to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms; b is a number having a value from 0 to about 12; a is a number having a value from 1 to about 6, the amount of foam generated by the composition is significantly reduced. 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 modified in all instances by the term "about" . Alkyl polyglycosides are primarily produced by two methods, i.e., direct synthesis and transacetalization. In the direct synthesis method, glucose is directly reacted with an excess of fatty alcohol in the presence of an acid as catalyst to form the glycoside. In the transacetalization method using a lower alcohol or glycol as solvent and reactant, a lower alkyl glycoside is initially formed and is then reacted with a long carbon- chain fatty alcohol in the following step to form the end product. It is known that alkyl polyglycosides are both readily biodegradable and non-toxic. However, it is also known that alkyl polyglycosides having C 8 -C 16 alkyl chains are foam generators. Thus, while their use in cleaning compositions as nonionic surfactants is desirable for both environmental and detersive reasons, their tendency towards foa production in applications where high foam levels are undesirable, such as in automatic dish washing detergents, floor cleaners, and high pressure spray cleaners, limits their desirability. Accordingly, the present invention relates to adding a defoa ing-effective amount of an alkoxylated alcohol having the general formula I: R 1 (E0) x (P0) y -0H I wherein R 1 is derived from a linear or branched alkyl chain having from about 8 to about 14 carbon atoms; x is a number having a value of from 1 to about 10; y is a number having a value of from 1 to about 10, to a cleaning composition containing an alkyl polyglycoside having the general formula II: R 3 0(R 4 0) b (Z) a II wherein R 3 is a monovalent organic radical having from about 6 to about 30 carbon atoms; R 4 is divalent alkylene radical having from 2 to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms; b is a number having a value from 0 to about 12; a is a number having a value from 1 to about 6. The ratio of alkoxylated alcohol of formula I to alkyl polyglycoside of formula II is typically in the range of from 1:10 to 10:1. Cleaning compositions typically contain various surfactants such as nonionic, anionic and amphoteric surfactants, as well as mixtures thereof. Additional components may include builders such as silicates, phosphates, tetrasodium EDTA, and NTA. Buffer components may also be employed in order to regulate the pH of the cleaning composition. Examples of suitable buffer components include sodium carbonate, triethanolamine, NaOH, and KOH. Other components typically found in cleaning compositions include corrosion inhibitors, dyes, fragrances, preservatives, and solvents . The surfactant employed in the cleaning composition of the present process is an alkyl polyglycoside having the general formula II: R 3 0(R 4 0) b (Z) a II wherein R 3 is a monovalent organic radical having from about 6 to about 30 carbon atoms; R 4 is divalent alkylene radical having from 2 to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms; b is a number having a value from 0 to about 12; a is a number having a value from 1 to about 6. Such alkyl polyglycosides are commercially available, for example, as APG®, GLUCOPON®, or PLANTAREN® surfactants from Henkel Corporation, Ambler, PA., 19002. Examples of such surfactants include but are not limited to: 1. APG® 225 Surfactant - an alkyl polyglycoside in which the alkyl group contains 8 to 10 carbon atoms and having an average degree of polymerization of 1.7. 2. APG® 425 Surfactant - an alkyl polyglycoside in which the alkyl group contains 8 to 16 carbon atoms and having an average degree of polymerization of 1.6. 3. APG® 625 Surfactant - an alkyl polyglycoside in which the alkyl groups contains 12 to 16 carbon atoms and having an average degree of polymerization of 1.6. 4. APG® 325 Surfactant - an alkyl polyglycoside in which the alkyl groups contains 9 to 11 carbon atoms and having an average degree of polymerization of 1.5. 5. GLUCOPON® 600 Surfactant - an alkyl polyglycoside in which the alkyl groups con.tains 12 to 16 carbon atoms and having an average degree of polymerization of 1.4. 6. PLANTAREN® 2000 Surfactant - a C 8 . 16 alkyl polyglycoside in which the alkyl group contains 8 to 16 carbon atoms and having an average degree of polymerization of 1.4. 7. PLANTAREN® 1300 Surfactant - a C 12 . 16 alkyl polyglycoside in which the alkyl groups contains 12 to 16 carbon atoms and having an average degree of polymerization of 1.6. Other examples include alkyl polyglycoside surfactant compositions which are comprised of mixtures of compounds of formula I wherein Z represents a moiety derived from a reducing saccharide containing 5 or 6 carbon atoms; a is a number having a value from 1 to about 6; b is zero; and R-. is an alkyl radical having from 8 to 20 carbon atoms. The compositions are characterized in that they have increased surfactant properties and an HLB in the range of about 10 to about 16 and a non-Flory distribution of glycosides, which is comprised of a mixture of an alkyl monoglycoside and a mixture of alkyl polyglycosides having varying degrees of polymerization of 2 and higher in progressively decreasing amounts, in which the amount by weight of polyglycoside having a degree of polymerization of 2, or mixtures thereof with the polyglycoside having a degree of polymerization of 3 , predominate in relation to the amount of monoglycoside, said composition having an average degree of polymerization of about 1.8 to about 3. Such compositions, also known as peaked alkyl polyglycosides, can be prepared by separation of the monoglycoside from the original reaction mixture of alkyl monoglycoside and alkyl polyglycosides after removal of the alcohol. This separation may be carried out by molecular distillation and normally results in the removal of about 70-95% by weight of the alkyl monoglycosides . After removal of the alkyl monoglycosides, the relative distribution of the various components, mono- and poly-glycosides, in the resulting product changes and the concentration in the product of the polyglycosides relative to the monoglycoside increases as well as the concentration of individual polyglycosides to the total, i.e. DP2 and DP3 fractions in relation to the sum of all DP fractions. Such compositions are disclosed in U.S. patent 5,266,690, the entire contents of which are incorporated herein by reference. Other alkyl polyglycosides which can be used in the compositions according to the invention are those in which the alkyl moiety contains from 6 co 18 carbon atoms in which and the average carbon chain length of the composition is from about 9 to about 14 comprising a mixture of two or more of at least binary components of alkylpolyglycosides, wherein each binary component is present in the mixture in relation to its average carbon chain length in an amount effective to provide the surfactant composition with the average carbon chain length of about 9 to about 14 and wherein at least one, or both binary components, comprise a Flory distribution of polyglycosides derived from an acid-catalyzed reaction of an alcohol containing 6-20 carbon atoms and a suitable saccharide from which excess alcohol has been separated. As was noted previously, the use of alkyl polyglycoside surfactants of formula II as the nonionic surfactant in cleaning compositions, and particularly those alkyl polyglycosides of formula II wherein R 3 is a monovalent organic radical having from 8 to 10 carbon atoms, b is zero and a is a number having a value of 1.52, is attended by unwanted high levels of foaming. In order to reduce the level of foam generated by the alkyl polyglycosides of formula II present in cleaning compositions, it has been found that by adding an effective amount of an alkoxylated alcohol having the general formula I: R 1 (EO) x (PO) y -OH I wherein R λ is derived from a linear or branched alkyl chain having from about 8 to about 14 carbon atoms; x is a number having a value of from 1 to about 10; y is a number having a value of from 1 to about 10, the amount of foam generated by the alkyl polyglycoside-containing cleaning composition can be significantly reduced. A preferred alkoxylated alcohol of formula I is one wherein the number y is greater than x, i.e., there are more propylene oxides than ethylene oxide and a particularly preferred alkoxylated alcohol is one having a molar ratio of ethylene oxide to propylene oxide of about 1:2, respectively. In one embodiment of the present invention, the cleaning composition employed in the present process contains: up to 97.9% by weight of a builder component; from about 1 to about 10% by weight of a buffer component; from about 0.1 to about 50% by weight of an alkyl polyglycoside of formula II; and from about 1 to about 2% by weight of an alkoxylated alcohol of formula I, all weights being based on the weight of the cleaning composition. The ratio by weight of alkyl polyglycoside of formula II to alkoxylated alcohol of formula I is preferably in the range of from 4:1 to 1:1. Preferably, from about 0.1 to about 5%, and particularly from about 1 to about 3% by weight, based on the weight of the cleaning composition, of the alkoxylated alcohol of formula I is added to the cleaning composition. In a particularly preferred embodiment of the present invention, the cleaning composition contains the alkyl polyglycoside of formula II wherein R 3 is an alkyl radical having from 8 to 10 carbon atoms, b is zero, and a is a number having a value of 1.52. This alkyl polyglycoside is preferably present in the cleaning composition in an amount of from about 3 to 4% by weight, based on the weight of the composition. To this composition there is added an effective amount of alkoxylated alcohol of formula I such that the ratio by weight of alkyl polyglycoside of formula II wherein R 3 is a C 8 -C 10 alkyl radical to alkoxylated alcohol of formula I is from 1:10 to 10:1, and most preferably 1:1, respectively. 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. Various blends of alkoxylated alcohols of formula I and alkyl polyglycosides of formula II were prepared and tested using the Ross Miles Foam Test (ASTM D1173-53) to determine their defoaming capabilities. The blend compositions and results obtained therefrom are listed in Table I below. Unless otherwise indicated, percentages are on a wt% actives basis . Table I Example wt% wt% BL- wt% LS- wt% APG® Foam Height SX-602 214 36 220 UP 1 min 5 min (mm) (mm) 1 0.1 145 145 2 0.05 0.05 5 5 3 0.05 0.05 70 15 4 0.05 0.05 15 5 (a) SX-602 = SANDOXYLATE® SX-602, an alkoxylated alcohol commercially available from Sandoz, Corp. (b) BL-214 = ANTAROX® BL-214, an alkoxylated alcohol commercially available from Rhone-Poulenc. (c) LS-36 = DEHYPON® LS-36, an alkoxylated alcohol commercially available from Henkel KGaA, Dusseldorf, Germany. (d) APG® 220 UP is an alkyl polyglycoside in which the alkyl group contains 8 to 10 carbon atoms and having an average degree of polymerization of 1.52, sold by Henkel Corporation, Ambler, PA. Various formulations were also tested using the Waring Blender test method for determining their defoaming effectiveness. The blend compositions and results obtained using this test method are listed in Table II below. In Examples 5-8 below, 0.5% active solutions were prepared at 25°C, using 150 ppm hard water. The Waring Blender was run at constant high speed for approximately 3.5 minutes, after which the foam height was measured. Table II Example wt% wt% BL- wt% LS- wt% APG® Foam Height SX-602 214 36 220 UP Volume (ml) 5 0.50 800 6 0.25 0.25 168 7 0.25 0.25 183 8 0.25 0.25 178 As can be seen from the results obtained in Tables I and II, the foa produced after blending an alkoxylated alcohol of formula I with an alkyl polyglycoside of formula II is significantly decreased, as compared to the amount of foam produced by an alkyl polyglycoside of formula II by itself.

Claims: What is claimed is: I. A process for reducing foam in an alkyl polyglycoside- containing cleaning composition by adding a defoaming- effective amount of an alkoxylated alcohol having the general formula I: R 1 (EO) x (PO) y -OH I wherein R is derived from a linear or branched alkyl chain having from about 8 to about 14 carbon atoms; x is a number having a value of from 1 to about 10; y is a number having a value of from 1 to about 10, to a composition containing an alkyl polyglycoside having the general formula II: R 3 0(R 4 0) b (Z) a II wherein R 3 is a monovalent organic radical having from about 6 to about 30 carbon atoms; R 4 is divalent alkylene radical having from 2 to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms; b is a number having a value from 0 to about 12; a is a number having a value from 1 to about 6. 2. The process of claim 1 wherein in formula II R 3 is a monovalent organic radical having from 8 to 10 carbon atoms, b is zero and a is a number having a value of 1.52. 3. The process of claim 1 wherein from about 0.1 to about 5% by weight of said alkoxylated alcohol of formula I is added to said composition containing from about 0.1 to about 50% by weight of said alkyl polyglycoside of formula II, all weights based on the weight of said cleaning composition. 4. The process of claim 1 wherein said alkoxylated alcohol and said alkyl polyglycoside are present in said cleaner composition in a ratio by weight of from 1:10 to 10:1, respectively. 5. The process of claim 1 wherein said alkoxylated alcohol of formula I and said alkyl polyglycoside of formula II are present in said cleaner composition in a ratio by weight of 1:1, respectively. 6. The process of claim 2 wherein said alkoxylated alcohol of formula I and said alkyl polyglycoside of formula II are present in said cleaning composition in a ratio by weight of 1:1, respectively. 7. The process of claim 2 wherein from about 1 to about 3% by weight of said alkoxylated alcohol of formula I is added to said composition containing from about 3 to about 4% by weight of said alkyl polyglycoside of formula II, all weights based on the weight of said cleaning composition. 8. The process of claim 1 wherein said cleaner composition contains an additive selected from the group consisting of a builder, a buffer, a corrosion inhibitor, a preservative, a dye, a fragrance, a solvent, and mixtures thereof. 9. The process of claim 8 wherein said additive is a builder present in an amount of up to 97.9% by weight, based on the weight of said composition. 10. The process of claim 8 wherein said additive is a buffer present in an amount of from about 1 to about 10% by weight, based on the weight of said composition. 11. The process of claim 1 wherein in formula I y is greater than x. 12. The process of claim 1 wherein in formula I the ratio of x to y is 1:2, respectively. 13. The product of the process of claim 1. 14. The product of the process of claim 2. 15. The product of the process of claim 3. 16. The product of the process of claim 4. 17. The product of the process of claim 5. 18. The product of the process of claim 6. 19. The product of the process of claim 7. 20. The product of the process of claim 8. 21. The product of the process of claim 9. 22. The product of the process of claim 10. 23. The product of the process of claim 11. 24. The product of the process of claim 12.

Inventors: GROSS STEPHEN F, GROSS, STEPHEN, F.
Applicants: HENKEL CORP, HENKEL CORPORATION
Application year: 1996
Main classification: C11D1
IPC codes: C11D1