Patent Application
20070111914
The present invention relates to laundry methods and laundry kits based on laundry detergent compositions comprising alkoxylated carboxylic acid ester surfactants and laundry rinse aid compositions comprising certain hydrolases.
Environmentally friendly cleaning products, including laundry products, are becoming increasingly in demand. Many restrictions on formulations are imposed by environmental laws, by universal need to conserve water, by higher prices for non-renewable chemical sources, and by increasing consumer awareness and preference for environmentally friendly products.
One trend in laundry cleaning is to conserve water usage. In some areas of the world, water supply is so limited that cleaning clothes with minimum rinse water or even without rinsing altogether is highly desirable. Also, front-loading washing machines which have smaller drums and thus use less water than traditional washing machines, are becoming increasingly popular. Unfortunately, while the main wash cycle is accomplished with less water, multiple rinses are generally required to remove surfactants used to clean the laundry in the main wash. Part of the problem is consumer perception: surfactant cleaning action is accompanied by foaming, and consumers attempt to remove the foam by repeated/multiple rinsing. Multiple rinses are also required in hand washing of fabrics due to inefficiency of foam removal by wringing the fabrics.
Another trend is to switch to more environmentally friendly surfactants, such as alkoxylated carboxylic acid ester surfactant, which are biodegradable and are derived from a renewable source—natural oils and fats.
Thus, laundry cleaning which employs an alkoxylated ester surfactant for cleaning and subsequently reduces foaming is highly desirable. That is, an environmentally friendly way of achieving cleaning, yet also removing foaming is needed.
The following art describes compositions, in some instances laundry compositions, that may include various, broadly ranging carboxylic acid esters and/or alkoxylated derivatives thereof: Koester et al. (U.S. Pat. No. 6,384,009), Hees et al. (U.S. Pat. No. 5,753,606), WO 01/10391, WO 96/23049, WO 94/13618, Miyajima et al. (U.S. Pat. No. 6,417,146), JP 9078092, JP 9104895, JP 8157897, JP 8209193 and JP 3410880.
Some uses of enzymes from hydrolase family with esterified compounds have been described by Pel, et al. (WO 97/36000), U.S. Pat. No. 6,605,452, Maeder et al. (US 2003/0027786 A1), WO 96/29389, JP 2958444, EP 0814149, EP 0814152, DE 4433676, JP 07053999, JP 05222396, JP 05202382, JP 0525037, JP 54085176, WO 2004/083420, and EP 1475431.
The present invention includes a method of washing laundry, the method comprising washing laundry in an aqueous medium with two separate compositions:
The invention also includes laundry kits based on the laundry detergent and the rinse aid compositions.
Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word “about.” All amounts are by weight of the detergent or rinse aid composition, unless otherwise specified.
It should be noted that in specifying any range of concentration, any particular upper concentration can be associated with any particular lower concentration.
For the avoidance of doubt the word “comprising” is used herein in its ordinary meaning and is intended to mean “including” but not necessarily “consisting of” or “composed of.” In other words, the listed steps or options need not be exhaustive.
“Liquid” as used herein means that a continuous phase or predominant part of the composition is liquid and that a composition is flowable at 15° C. and above (i.e., suspended solids may be included). Gels are included in the definition of liquid compositions as used herein.
“Wash load” as used herein means the weight of apparel, clothes, towels, garment, and other articles that are washed either in a wash machine or other container.
“Substantial reduction of foaming” as used herein means that the foam height of the wash liquor reduces by at least 50%, preferably by at least 70% and most preferably by more than 90% in comparison to the initial wash condition (no contact between ester surfactant and carboxylic ester hydrolase enzyme), measured by the Ross-Miles Foam method at the 5-minute interval.
The inventive laundry method and laundry kit employ laundry detergent composition comprising an alkoxylated carboxylic acid ester and rinse aid composition comprising a carboxylic ester hydrolase enzyme.
Method of Washing Laundry
According to the inventive method of washing laundry, by virtue of using a laundry detergent composition comprising an alkoxylated ester surfactant, along with or followed by, the use of a rinse aid composition comprising a carboxylate ester hydrolase enzyme, an environmentally friendly cleaning is made possible, since a preferred surfactant is employed, and furthermore foaming can be effectively reduced using the minimum amount of water. The de-foaming of the detergent is achieved by the action of the carboxylate ester hydrolase enzyme on the alkoxylated ester surfactant to decompose the surfactant, which results in the production, inter alia, of a soap/fatty acid which acts as a de-foamer.
The decomposition reaction follows a kinetic route and is dependent on temperature, relative concentrations of the ester surfactant and ester hydrolase enzyme, pH and degree of agitation. Typically, temperature of water is in the range of from 4 to 60° C., preferably 10 to 45° C. and the weight ratio of the hydrolase enzyme to the ester surfactant is in the range of from 0.00001 to 1, preferably from 0.0001 to 0.1. The composition is designed and controlled so that the decomposition is sufficiently delayed to achieve cleaning, as it will only start at about 1 to 25 minute point, allowing the surfactant to work on the stains/soils, yet it will allow for the de-foaming of the surfactant by about 5 to 60 minute point. In the other embodiment, the composition is designed and controlled that the decomposition is started at about 0.01 to 10 minutes point and allow for the de-foaming of the surfactant by 0.05 to 15 minutes for easy rinsing. The rinse aid composition is formulated to fit various wash machines, conditions and habits. In addition, the timing of the addition of rinse aid may also be used as a control of time for efficient wash.
In the embodiment of the invention when the detergent composition and the rinse aid composition are introduced at the start or in the middle of the washing cycle. Preferably, one rinse or no rinsing cycle is needed after the washing cycle.
In another embodiment of the inventive method the rinse aid composition is added after the laundry has been washed with the laundry detergent composition and the wash liquor wrung out, typically during a rinsing step.
In yet another embodiment of the inventive method, washing of the laundry may be conducted without a separate rinsing step, after the introduction of the inventive detergent composition and the rinse aid composition.
Both embodiments of the inventive method may be carried out by hand or using an automatic laundry machine, or a mixed method (e.g. using the machine for washing and wringing out, but rinsing by hand).
When an automatic laundry machine is employed, with a separate rinse cycle, the rinse cycle duration is generally at least 3 and at most 30 minutes. In a preferred method, a single rinse with a reasonably short time in general from 3 to 30 minutes, preferably from 5 to 20 minutes, most preferably from 6 to 15 minutes is employed, with the rinse aid added composition added in the rinse cycle. According to the preferred embodiment the inventive method employs a front loading washing machine. The front loading washing machines employ lower volumes of water than the top loading washing machine. In a preferred embodiment of the inventive method, a single rinse is sufficient. Generally, the volume of the aqueous rinse medium is from 10 to 100 liters preferably. The volume is from 8 to 30 liters for front loading laundry washing machines, preferably from 10 to 25 liters. Generally, wash load to wash/rinse liquor weight ratio is from 0.01 to 1, preferably from 0.05 to 0.8, and most preferably from 0.1 to 0.5. Although there is a broader variation for hand wash, the range for wash load to wash/rinse water ratio is about the same. For the hand wash, it is preferred to add the rinse aid composition at 0 to 5 minutes before the end of hand wash.
ALKOXYLATED CARBOXYLIC ACID ESTERS (also sometimes referred to herein as “alkoxylated esters”) included in the present invention have Formula (I) as follows
The preferred compounds of formula (I) in the inventive compositions are selected from alkoxylated derivatives derived from coconut, palm, palm kernel, palm stearin, tallow, soybean and rapeseed oil due to their availability.
Carboxylic acid esters are available commercially or may be prepared by the trans-esterification of glycerides, preferrably from natural oil or fat, and the esterification of carboxylic acid with alcohol, e.g. methanol or ethanol, to form carboxylic acid ester; the alkoxylated derivatives may be obtained by the alkoxylation of carboxylic acid ester with alkylene oxide with the presence of catalyst. Carboxylic acid esters are also widely available as “bio-diesel”. Twin Rivers Technologies provides various types of carboxylic acid esters. Huntsman provides various alkoxylated carboxylic methyl esters.
The amount of the alkoxylated ester employed in the laundry detergent compositions is in the range of from 1% to 80%, preferably from 2% to 50%, most preferably from 3% to 20%, optimally from 4% to 15%, by weight of the composition.
In general, a detergent composition may contain a non-ester surfactant. The products from the decomposition of ester surfactant, soap/fatty acid, are solubilized by other surfactants, especially non-ester surfactants, and reduce/remove foam as a general defoamer. Thus, preferably, to achieve the efficient and substantial defoaming, the laundry detergent' surfactant is comprised of sufficient amount of the alkoxylated carboxylic acid ester surfactant. In the preferred composition at least 15% of the surfactant present, preferably at least 40% and most preferably at least 55%, is in the form of the alkoxylated carboxylic acid ester surfactant.
The concentration of alkoxylated esters in an aqueous wash liquor preferably in the range of from 1 ppm to 200,000 ppm. Preferably the concentration of the surfactant in a wash liquid is in the range of from 10 ppm to 50,000 ppm, most preferably from 100,000 ppm to 5,000 ppm.
Carboxylic Ester Hydrolases
Suitable enzymes for the invention are selected from hydrolases classified under the Enzyme Classification number E.C. 3.1.1 (Carboxylic Ester Hydrolases) as described by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NCIUBMB). (http://www.chem.qmul.ac.uk/iubmb/). This family of enzymes catalyzes the hydrolysis of carboxylic acid esters with the formation of a carboxylic acid and an alcohol. Within this subclass, the preferred hydrolases are carboxylesterases (EC 3.1.1.1), triacylglycerol lipase (EC 3.1.1.3), lipoprotein lipase (EC 3.1.1.34), and cutinase (EC 3.1.1.74) are included in the rinse aid composition. Most preferably, brand name enzymes Lipolase® (EC 3.1.1.3), Lipex® (EC 3.1.1.3), Cutinase® (3.1.1.74), and Esterase® (EC 3.1.1.1) are employed. The amount of the carboxylic ester hydrolases in the rinse aid composition is in the range of from 0.001% to about 100%, preferably from 0.1% to 50% and most preferably from 1% to 10% to effect the substantial defoaming under the most economically feasible conditions. The amount of the carboxylic ester hydrolases in the aqueous wash (or rinse) liquid is from 0.1 ppm to 500 ppm, preferably from 0.5 ppm to 100 ppm and most preferably from 1 ppm to 25 ppm. As used herein, the amounts of the enzymes are based on the commercially available enzyme preparations: i.e., “100% enzyme” means “100% of the commercial preparation.” Commercial preparations typically contain additional ingredients, such as diluents, stabilizers, and others.
Laundry Kits
The inventive laundry kit employs a detergent composition comprising an alkoxylated ester surfactant in conjunction with the rinse aid composition comprising a carboxylate ester hydrolase enzyme. The detergent composition may be a solid or a liquid. Preferably, the detergent composition is a liquid composition, which is preferred by consumers over powders. Furthermore, the liquid composition is advantageous when the laundry detergent composition and the rinse aid are both introduced at the start of the wash, to accelerate the cleaning action of the surfactant on clothes, to avoid the time span required to solubilise and disperse the surfactant out of solid compositions, since only limited time is available before the start of the decomposition of the surfactant.
The hydrolase-containing rinse aid composition needs to be physically segregated from the detergent composition containing the ester surfactant, to prevent the decomposition of the surfactant on storage. Such decomposition may occur even in a solid composition containing both the alkoxylated surfactant and the hydrolase enzyme—due to humidity, or poor storage conditions. The inventive laundry kit may include a jointly marketed product containing two separate containers. The kit may also include separately marketed laundry detergent composition and rinse aid composition or refills, which both contain instructions for joint use. Another embodiment of the inventive kit is a single package with a dual dispenser. The inventive laundy kit may combine solid detergent with liquid rinse aid, or liquid detergent with solid rinse aid. Of course, solid/solid and liquid/liquid permutations are also included.
The wash and/or rinse water temperature used in the inventive method is typically within the range of from 4 to 60° C., preferably from 10 to 45° C.
Detergent Composition
Laundry detergent compositions included in the present invention may contain the following ingredients, besides an alkoxylated ester surfactant.
Surfactant
The overall amount of surfactant in the inventive compositions is generally in the range of from 5 to 80%, preferably from 10 to 60%, most preferably from 15 to 50%. The alkoxylated ester of the present invention is a nonionic surfactant. Thus, the alkoxylated ester may be the sole surfactant in the composition, or may be co-present with other surfactants. Preferably the alkoxylated ester surfactant is included in the inventive compositions in combination with anionic, cationic and amphoteric surfactant, most preferably anionic surfactant. The preferred ratio of alkoxylated ester surfactant to the sum of other surfactants is between 5:1 to 1:5, and more preferably between 3:1 to 1:3.
Furthermore, it is to be understood that any surfactant described below may be used in combination with any other surfactant or surfactants.
Anionic Surfactant Detergents
Anionic surface active agents which may be used in the present invention are those surface active compounds which contain a long chain hydrocarbon hydrophobic group in their molecular structure and a hydrophilic group, i.e. water soluble group such as carboxylate, sulfonate or sulfate group or their corresponding acid form. The anionic surface active agents include the alkali metal (e.g. sodium and potassium) and nitrogen based bases (e.g. mono-amines and polyamines) salts of water soluble higher alkyl aryl sulfonates, alkyl sulfonates, alkyl sulfates and the alkyl polyether sulfates. They may also include fatty acid or fatty acid soaps. One of the preferred groups of mono-anionic surface active agents are the alkali metal, ammonium or alkanolamine salts of higher alkyl aryl sulfonates and alkali metal, ammonium or alkanolamine salts of higher alkyl sulfates or the mono-anionic polyamine salts. Preferred higher alkyl sulfates are those in which the alkyl groups contain 8 to 26 carbon atoms, preferably 12 to 22 carbon atoms and more preferably 14 to 18 carbon atoms. The alkyl group in the alkyl aryl sulfonate preferably contains 8 to 16 carbon atoms and more preferably 10 to 15 carbon atoms. A particularly preferred alkyl aryl sulfonate is the sodium, potassium or ethanolamine C10 to C16 benzene sulfonate, e.g. sodium linear dodecyl benzene sulfonate. The primary and secondary alkyl sulfates can be made by reacting long chain olefins with sulfites or bisulfites, e.g. sodium bisulfite. The alkyl sulfonates can also be made by reacting long chain normal paraffin hydrocarbons with sulfur dioxide and oxygen as describe in U.S. Pat. Nos. 2,503,280, 2,507,088, 3,372,188 and 3,260,741 to obtain normal or secondary higher alkyl sulfates suitable for use as surfactant detergents.
The alkyl substituent is preferably linear, i.e. normal alkyl, however, branched chain alkyl sulfonates can be employed, although they are not as good with respect to biodegradability. The alkane, i.e. alkyl, substituent may be terminally sulfonated or may be joined, for example, to the 2-carbon atom of the chain, i.e. may be a secondary sulfonate. It is understood in the art that the substituent may be joined to any carbon on the alkyl chain. The higher alkyl sulfonates can be used as the alkali metal salts, such as sodium and potassium. The preferred salts are the sodium salts. The preferred alkyl sulfonates are the C10 to C18 primary normal alkyl sodium and potassium sulfonates, with the C10 to C15 primary normal alkyl sulfonate salt being more preferred.
Mixtures of higher alkyl benzene sulfonates and higher alkyl sulfates can be used as well as mixtures of higher alkyl benzene sulfonates and higher alkyl polyether sulfates.
The higher alkyl polyethoxy sulfates used in accordance with the present invention can be normal or branched chain alkyl and contain lower alkoxy groups which can contain two or three carbon atoms. The normal higher alkyl polyether sulfates are preferred in that they have a higher degree of biodegradability than the branched chain alkyl and the lower poly alkoxy groups are preferably ethoxy groups.
The preferred higher alkyl polyethoxy sulfates used in accordance with the present invention are represented by the formula:
R1—O(CH2CH2O)p—SO3M,
where R1is C8 to C20 alkyl, preferably C10 to C18 and more preferably C12 to C15; p is 1 to 8, preferably 2 to 6, and more preferably 2 to 4; and M is an alkali metal, such as sodium and potassium, an ammonium cation or polyamine. The sodium and potassium salts, and polyaimines are preferred.
A preferred higher alkyl poly ethoxylated sulfate is the sodium salt of a triethoxy C12 to C15 alcohol sulfate having the formula:
C12-15—O—(CH2CH2O)3—SO3Na
Examples of suitable alkyl ethoxy sulfates that can be used in accordance with the present invention are C12-15 normal or primary alkyl triethoxy sulfate, sodium salt; n-decyl diethoxy sulfate, sodium salt; C12 primary alkyl diethoxy sulfate, ammonium salt; C12 primary alkyl triethoxy sulfate, sodium salt; C15 primary alkyl tetraethoxy sulfate, sodium salt; mixed C14-15 normal primary alkyl mixed tri- and tetraethoxy sulfate, sodium salt; stearyl pentaethoxy sulfate, sodium salt; and mixed C10-18 normal primary alkyl triethoxy sulfate, potassium salt.
The normal alkyl ethoxy sulfates are readily biodegradable and are preferred. The alkyl poly-lower alkoxy sulfates can be used in mixtures with each other and/or in mixtures with the above discussed higher alkyl benzene, sulfonates, or alkyl sulfates.
The anionic surfactant is present in an amount of from 0 to 70%, preferably at least 5%, generally from 5 to 50%, more preferably from 5 to 20%.
Additional Nonionic Surfactant
Nonionic surfactants in addition to the alkoxylated ester surfactants may be included. As is well known, the nonionic surfactants are characterized by the presence of a hydrophobic group and an organic hydrophilic group and are typically produced by the condensation of an organic aliphatic or alkyl aromatic hydrophobic compound with ethylene oxide (hydrophilic in nature). Typical suitable nonionic surfactants are those disclosed in U.S. Pat. Nos. 4,316,812 and 3,630,929, incorporated by reference herein.
Usually, the nonionic surfactants are polyalkoxylated lipophiles wherein the desired hydrophile-lipophile balance is obtained from addition of a hydrophilic poly-alkoxy group to a lipophilic moiety. A preferred class of nonionic detergent is the alkoxylated alkanols wherein the alkanol is of 9 to 20 carbon atoms and wherein the number of moles of alkylene oxide (of 2 or 3 carbon atoms) is from 3 to 20. Of such materials it is preferred to employ those wherein the alkanol is a fatty alcohol of 9 to 11 or 12 to 15 carbon atoms and which contain from 5 to 9 or 5 to 12 alkoxy groups per mole. Also preferred is paraffin—based alcohol (e.g. nonionics from Huntsman or Sassol).
Exemplary of such compounds are those wherein the alkanol is of 10 to 15 carbon atoms and which contain about 5 to 12 ethylene oxide groups per mole, e.g. Neodol® 25-9 and Neodol® 23-6.5, which products are made by Shell Chemical Company, Inc. The former is a condensation product of a mixture of higher fatty alcohols averaging about 12 to 15 carbon atoms, with about 9 moles of ethylene oxide and the latter is a corresponding mixture wherein the carbon atoms content of the higher fatty alcohol is 12 to 13 and the number of ethylene oxide groups present averages about 6.5.
Another subclass of alkoxylated surfactants which can be used contain a precise alkyl chain length rather than an alkyl chain distribution of the alkoxylated surfactants described above. Typically, these are referred to as narrow range alkoxylates. Examples of these include the Neodol-1(R) series of surfactants manufactured by Shell Chemical Company.
Other useful nonionics are represented by the commercially well known class of nonionics sold under the trademark Plurafac® by BASF. The Plurafacs® are the reaction products of a higher linear alcohol and a mixture of ethylene and propylene oxides, containing a mixed chain of ethylene oxide and propylene oxide, terminated by a hydroxyl group. Examples include C13-C15 fatty alcohol condensed with 6 moles ethylene oxide and 3 moles propylene oxide, C13-C15 fatty alcohol condensed with 7 moles propylene oxide and 4 moles ethylene oxide, C13-C15 fatty alcohol condensed with 5 moles propylene oxide and 10 moles ethylene oxide or mixtures of any of the above.
Another group of liquid nonionics are commercially available from Shell Chemical Company, Inc. under the Dobanol® or Neodol® trademark: Dobanol® 91-5 is an ethoxylated C9-C11 fatty alcohol with an average of 5 moles ethylene oxide and Dobanol® 25-7 is an ethoxylated C12-C15 fatty alcohol with an average of 7 moles ethylene oxide per mole of fatty alcohol.
In the compositions of this invention, preferred nonionic surfactants include the C12-C15 primary fatty alcohols with relatively narrow contents of ethylene oxide in the range of from about 5 to 9 moles, and the C9 to C11 fatty alcohols ethoxylated with about 5-6 moles ethylene oxide.
Another class of nonionic surfactants which can be used in accordance with this invention are glycoside surfactants. Glycoside surfactants suitable for use in accordance with the present invention include those of the formula:
RO—(R2O)y-(Z)x
wherein R is a monovalent organic radical containing from about 6 to about 30 (preferably from about 8 to about 18) carbon atoms; R2 is a divalent hydrocarbon radical containing from about 2 to 4 carbons atoms; O is an oxygen atom; y is a number which can have an average value of from 0 to about 12 but which is most preferably zero; Z is a moiety derived from a reducing saccharide containing 5 or 6 carbon atoms; and x is a number having an average value of from 1 to about 10 (preferably from about 1½ to about 10).
A particularly preferred group of glycoside surfactants for use in the practice of this invention includes those of the formula above in which R is a monovalent organic radical (linear or branched) containing from about 6 to about 18 (especially from about 8 to about 18) carbon atoms; y is zero; z is glucose or a moiety derived therefrom; x is a number having an average value of from 1 to about 4 (preferably from about 1½ to 4). Nonionic surfactants which may be used include polyhydroxy amides as discussed in U.S. Pat. No. 5,312,954 to Letton et al. and aldobionamides such as disclosed in U.S. Pat. No. 5,389,279 to Au et al., both of which are hereby incorporated by reference into the subject application.
Mixtures of two or more of the nonionic surfactants can be used.
Generally, nonionics (other than alkoxylated esters required by the present invention) would comprise 0-75%, preferably 2 to 50%, more preferably 0 to 15%, most preferably 0 to 10%. The level of nonionic surfactant may be lowered compared to the typical compositions, due to the unexpected advantage of the alkoxylated ester surfactants contribution to the oily soil removal.
Preferred inventive compositions comprise both anionic and nonionic surfactants, typically in a weight ratio of from 1:4 to 4:1.
Cationic Surfactants
Many cationic surfactants are known in the art, and almost any cationic surfactant having at least one long chain alkyl group of about 10 to 24 carbon atoms is suitable in the present invention. Such compounds are described in “Cationic Surfactants”, Jungermann, 1970, incorporated by reference.
Specific cationic surfactants which can be used as surfactants in the subject invention are described in detail in U.S. Pat. No. 4,497,718, hereby incorporated by reference.
As with the nonionic and anionic surfactants, the compositions of the invention may use cationic surfactants alone or in combination with any of the other surfactants known in the art. Of course, the compositions may contain no cationic surfactants at all.
Amphoteric Surfactants
Ampholytic synthetic surfactants can be broadly described as derivatives of aliphatic or aliphatic derivatives of heterocyclic secondary and tertiary amines in which the aliphatic radical may be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and at least one contains an anionic water-soluble group, e.g. carboxylate, sulfonate, sulfate. Examples of compounds falling within this definition are sodium 3-(dodecylamino)propionate, sodium 3-(dodecylamino) propane-1-sulfonate, sodium 2-(dodecylamino)ethyl sulfate, sodium 2-(dimethylamino) octadecanoate, disodium 3-(N-carboxymethyldodecylamino)propane 1-sulfonate, disodium octadecyl-imminodiacetate, sodium 1-carboxymethyl-2-undecylimidazole, and sodium N,N-bis (2-hydroxyethyl)2-sulfato-3-dodecoxypropylamine. Sodium 3-(dodecylamino) propane-1-sulfonate is preferred.
Zwitterionic surfactants can be broadly described as derivatives of secondary and tertiary amines, derivatives of heterocyclic secondary and tertiary amines, or derivatives of quaternary ammonium, quaternary phosphonium or tertiary sulfonium compounds. The cationic atom in the quaternary compound can be part of a heterocyclic ring. In all of these compounds there is at least one aliphatic group, straight chain or branched, containing from about 3 to 18 carbon atoms and at least one aliphatic substituent containing an anionic water-soluble group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate.
Specific examples of zwitterionic surfactants which may be used are set forth in U.S. Pat. No. 4,062,647, hereby incorporated by reference.
Water
When the laundry detergent compositions included in the present invention are liquid, then they contain water as major solvent. The inventive compositions comprise generally from 15% to 90%, preferably from 30% to 80%, most preferably, to achieve optimum cost and ease of manufacturing, from 40% to 70% of water. Other liquid components, such as solvents, surfactants, liquid organic matters including organic bases, and their mixtures can be co-present.
Solvents that may be present include but are not limited to alcohols, surfactant, fatty alcohol ethoxylated sulfate or surfactant mixtures, alkanol amine, polyamine, other polar or non-polar solvents, and mixtures thereof.
Additional Laundry Ingredients
The inventive compositions may include an additional laundry ingredient selected from the group consisting of enzyme, fluorescent agent, soil release polymer, anti-redeposition polymer, anti- dye transfer agents and mixtures thereof. These are described in greater detail below.
Builders/Electrolytes
Builders which can be used according to this invention include conventional alkaline detergency builders, inorganic or organic, which should be used at levels from about 0.1% to about 20.0% by weight of the composition, preferably from 1.0% to about 10.0% by weight, more preferably 2% to 5% by weight.
Any water-soluble salt may be used as electrolyte. Electrolyte may also be a detergency builder, such as the inorganic builder sodium tripolyphosphate, or it may be a non-functional electrolyte such as sodium sulphate or chloride. Preferably the inorganic builder comprises all or part of the electrolyte. That is the term electrolyte encompasses both builders and salts.
Examples of suitable inorganic alkaline detergency builders which may be used are water-soluble alkali metal phosphates, polyphosphates, borates, silicates and also carbonates. Specific examples of such salts are sodium and potassium triphosphates, pyrophosphates, orthophosphates, hexametaphosphates, tetraborates, silicates and carbonates.
Examples of suitable organic alkaline detergency builder salts are: (1) water-soluble amino polycarboxylates, e.g., sodium and potassium ethylenediaminetetraacetates, nitrilotriacetates and N-(2hydroxyethyl)-nitrilodiacetates; (2) water-soluble salts of phytic acid, e.g., sodium and potassium phytates (see U.S. Pat. No. 2,379,942); (3) water-soluble polyphosphonates, including specifically, sodium, potassium and lithium salts of ethane-1-hydroxy-1,1-diphosphonic acid; sodium, potassium and lithium salts of methylene diphosphonic acid; sodium, potassium and lithium salts of ethylene diphosphonic acid; and sodium, potassium and lithium salts of ethane-1,1,2-triphosphonic acid. Other examples include the alkali metal salts of ethane-2-carboxy-1,1-diphosphonic acid hydroxymethanediphosphonic acid, carboxyl diphosphonic acid, ethane-1-hydroxy-1,1,2-triphosphonic acid, ethane-2-hydroxy-1,1,2-triphosphonic acid, propane-1,1,3,3-tetraphosphonic acid, propane-1,1,2,3-tetraphosphonic acid, and propane-1,2,2,3-tetraphosphonic acid; (4) water-soluble salts of polycarboxylate polymers and copolymers as described in U.S. Pat. No 3,308,067.
In addition, polycarboxylate builders can be used satisfactorily, including water-soluble salts of mellitic acid, citric acid, and carboxymethyloxysuccinic acid, imino disuccinate, salts of polymers of itaconic acid and maleic acid, tartrate monosuccinate, tartrate disuccinate and mixtures thereof.
Sodium citrate is particularly preferred, to optimize the function vs. cost, in an amount of from 0 to 15%, preferably from 1 to 10%.
Certain zeolites or aluminosilicates can be used. One such aluminosilicate which is useful in the compositions of the invention is an amorphous water-insoluble hydrated compound of the formula (NaAlO2)x.(SiO2)y, wherein x is a number from 1.0 to 1.2 and y is 1, said amorphous material being further characterized by a Mg++ exchange capacity of from about 50 mg eq. CaCO3/g. and a particle diameter of from about 0.01 micron to about 5 microns. This ion exchange builder is more fully described in British Pat. No. 1,470,250.
A second water-insoluble synthetic aluminosilicate ion exchange material useful herein is crystalline in nature and has the formula Naz[(AlO2)y.(SiO2)]xH2O, wherein z and y are integers of at least 6; the molar ratio of z to y is in the range from 1.0 to about 0.5, and x is an integer from about 15 to about 264; said alumino silicate ion exchange material having a particle size diameter from about 0.1 micron to about 100 microns; a calcium ion exchange capacity on an anhydrous basis of at least about 200 milligrams equivalent of CaCO3 hardness per gram; and a calcium exchange rate on an anhydrous basis of at least about 2 grains/gallon/minute/gram. These synthetic aluminosilicates are more fully described in British Patent No. 1,429,143.
Enzymes
One or more enzymes, in addition to the hydrolases as described in detail below, may be used in the compositions of the invention.
If a lipase is used, it has to be isolated from the alkoxylated ester surfactant in the inventive compositions, either by encapsulation or in separate compartments due to the ability of lipase to decompose esters. The lipolytic enzyme may be either a fungal lipase producible by Humicola lanuginosa and Thermomyces lanuginosa, or a bacterial lipase which shows a positive immunological cross-reaction with the antibody of the lipase produced by the microorganism Chromobacter viscosum var. lipolyticum NRRL B-3673.
An example of a fungal lipase as defined above is the lipase ex Humicola lanuginosa, available from Amano under the tradename Amano CE; the lipase ex Humicola lanuginosa as described in the aforesaid European Patent Application 0,258,068 (NOVO), as well as the lipase obtained by cloning the gene from Humicola lanuginosa and expressing this gene in Aspergillus oryzae, commercially available from Novozymes under the tradename “Lipolase®”. This Lipolase® is a preferred lipase for use in the present invention.
While various specific lipase enzymes have been described above, it is to be understood that any lipase which can confer the desired lipolytic activity to the composition may be used and the invention is not intended to be limited in any way by specific choice of lipase enzyme.
The lipases of this embodiment of the invention are included in the detergent composition in such an amount that the final composition has a lipolytic enzyme activity of from 100 to 0.005 LU/ml in the wash cycle, preferably 25 to 0.05 LU/ml when the formulation is dosed at a level of about 0.1-10, more preferably 0.5-7, most preferably 1-2 g/liter.
Naturally, mixtures of the above lipases can be used. The lipases can be used in their non-purified form or in a purified form, e.g. purified with the aid of well-known absorption methods, such as phenyl sepharose absorption techniques.
If a protease is used, the proteolytic enzyme can be of vegetable, animal or microorganism origin. Preferably, it is of the latter origin, which includes yeasts, fungi, molds and bacteria. Particularly preferred are bacterial subtilisin type proteases, obtained from e.g. particular strains of Bacillus subtilis and Bacillus licheniformis. Examples of suitable commercially available proteases are Alcalase®, Savinase®, Esperase®, all of Novozymes; Properase®, Purafect® and Purafect Prime®, all of Genencor. The amount of proteolytic enzyme, included in the composition, ranges from 0.05-50,000 GU/mg. preferably 0.1 to 50 GU/mg, based on the final composition. Naturally, mixtures of different proteolytic enzymes may be used.
While various specific enzymes have been described above, it is to be understood that any protease which can confer the desired proteolytic activity to the composition may be used and this embodiment of the invention is not limited in any way to a specific choice of proteolytic enzyme.
In addition to lipases or proteases, it is to be understood that other enzymes such as cellulases, oxidases, amylases, peroxidases, esterases and the like which are well known in the art may also be used with the composition of the invention. The enzymes may be used together with co-factors required to promote enzyme activity, i.e., they may be used in enzyme systems, if required. It should also be understood that enzymes having mutations at various positions (e.g., enzymes engineered for performance and/or stability enhancement) are also contemplated by the invention.
The enzyme stabilization system may comprise calcium ion; boric acid, propylene glycol and/or short chain carboxylic acids. The composition preferably contains from about 0.01 to about 50, preferably from about 0.1 to about 30, more preferably from about 1 to about 20 millimoles of calcium ion per liter.
When calcium ion is used, the level of calcium ion should be selected so that there is always some minimum level available for the enzyme after allowing for complexation with builders, etc., in the composition. Any water-soluble calcium salt can be used as the source of calcium ion, including calcium chloride, calcium formate, calcium acetate and calcium propionate. A small amount of calcium ion, generally from about 0.05 to about 2.5 millimoles per liter, is often also present in the composition due to calcium in the enzyme slurry and formula water.
Another enzyme stabilizer which may be used is alkyl carboxylic acid, such as formic acid, propionic acid or its salt. When used, this stabilizer may be used in an amount from about 0.1% to about 15% by weight of the composition.
Another preferred enzyme stabilizer is polyols containing carbon, hydrogen and oxygen atoms. They preferably contain from 2 to 6 carbon atoms and from 2 to 6 hydroxy groups. Examples include cis-diols, propylene glycol (especially 1,2 propane diol which is preferred), ethylene glycol, glycerol, sorbitol, mannitol and glucose. The polyol generally represents from about 0.1 to 25% by weight, preferably about 1.0% to about 15%, more preferably from about 2% to about 8% by weight of the composition.
The composition herein may also optionally contain from about 0.25% to about 5%, most preferably from about 0.5% to about 3% by weight of boric acid. The boric acid may be, but is preferably not, formed by a compound capable of forming boric acid in the composition. Boric acid is preferred, although other compounds such as boric oxide, borax and other alkali metal borates (e.g., sodium ortho-, meta- and pyroborate and sodium pentaborate) are suitable. Substituted boric acids (e.g., phenylboronic acid, butane boronic acid and a p-bromo phenylboronic acid, and 4-formyl phenyl boronic acid) can also be used in place of boric acid.
One preferred stabilization system is a polyol in combination with boric acid. Preferably, the weight ratio of polyol to boric acid added is at least 1, more preferably at least about 1.3.
The inventive compositions preferably include from 0.01% to 2.0%, more preferably from 0.05% to 1.0%, most preferably from 0.05% to 0.5% of a fluorescer. Examples of suitable fluorescers include but are not limited to derivative of stilbene, pyrazoline, coumarin, carboxylic acid, methinecyamines, dibenzothiophene-5,5-dioxide azoles, 5-, and 6-membered-ring heterocycles, triazole and benzidine sulfone compositions, especially sulfonated substituted triazinyl stilbene, sulfonated naphthotriazole stilbene, benzidene sulfone, etc. Most preferred are UV/stable brighteners (for compositions visible in transparent containers), such as distyrylbiphenyl derivatives (Tinopal® CBS-X).
In addition, various other detergent additives or adjuvants may be present in the detergent product to give it additional desired properties, either of functional or aesthetic nature.
Improvements in the physical stability and anti-settling properties of the composition may be achieved by the addition of a small effective amount of an aluminum salt of a higher fatty acid, e.g., aluminum stearate, to the composition. The aluminum stearate stabilizing agent can be added in an amount of 0 to 3%, preferably 0.1 to 2.0% and more preferably 0.5 to 1.5%.
There also may be included in the formulation, minor amounts of soil suspending or anti-redeposition agents, e.g. polyvinyl alcohol, fatty amides, sodium carboxymethyl cellulose, hydroxy-propyl methyl cellulose.
Additional anti-foam agents, e.g. silicon compounds, such as Silicane® L 7604, can also be added.
Bactericides, e.g. tetrachlorosalicylanilide and hexachlorophene, fungicides, dyes, pigments (water dispersible), preservatives, e.g. formalin, ultraviolet absorbers, anti-yellowing agents, such as sodium carboxymethyl cellulose, pH modifiers and pH buffers, color safe bleaches, perfume and dyes and bluing agents such as Iragon Blue L2D, Detergent Blue 472/572 and ultramarine blue can be used.
Preferably, the detergent composition is a colored composition packaged in the transparent/translucent (“see-through”) container.
Process of Making
The inventive compositions may be prepared by any method known to one of ordinary skill in the art. Surfactants, including the alkoxylated ester surfactant are pre-mixed. The rest of the ingredients, if any, such as, whitening agent, functional polymers, perfume, enzyme, colorant, preservatives are then mixed to obtain a stable liquid. In general, the alkoxylated ester surfactant is preferably not contacted with a strong base, e.g. NaOH, to prevent the pre-mature degradation of the surfactant. If the contact between the alkoxylated ester surfactant and a strong base is necessary, then the contact time should be kept as short as possible.
In the case of powder detergents, spray-drying or non-tower routes of manufacturing are employed.
Rinse Aid Composition
Rinse aid compositions included in the invention may be solid or liquid. The main ingredient is the ester hydrolase enzyme.
The composition of liquid rinse aid comprises from 0.1% to 100% of commercially available liquid ester hydrolase. Liquid rinse aid may preferably also contain water, enzyme stabilizing system, colorant, preservative, buffer, perfume, electrolytes, functional polymer and surfactants. The surfactant level is less than 20%, preferably less than 10%, most preferably less than 5%.
In addition, solid rinse aid may also contain colorant, solid carrier, polymer, surfactant, and dissolution aid.
Liquid rinse aid is preferred over the powder rinse aid, due to its ease and safety of use. Powder may generate enzyme particulate dust and take longer time of dissolve. The rinse aid composition included in the present invention may also be dispensed in the form of unit dose.
The following specific examples further illustrate the invention, but the invention is not limited thereto.
The following abbreviations and/or tradenames were used in the Examples:
The alkoxylated ester surfactants decompose to fatty acid and/or soap depending on the pH. Both fatty acid and soap foam less that the alkoxylated ester surfactant—thus, leading to the de-foaming of the wash/rinse liquor
The procedure of Ross-Miles Foam Test method is listed below:
These Examples investigated the effect on the wash liquor containing an alkoxylated ester surfactant of rinse aid without carboxylate ester hydrolase in Comparative Example A (outside the scope of this invention) and rinse aid containing carboxylate ester hydrolase in Example 1 (within the scope of this invention). The same detergent composition was used for Comparative Example A and Example 1. The detergent was prepared by first adding water to a mix tank, followed by the addition of 50% NaOH solution and triethanolamine. Subsequently, citric acid 50% solution and LAS acid were added to the tank. After the neutralization, MEE was then added to the tank, mixed until the whole composition became isotropic. The rinse composition in Example 1 is prepared by diluting lipase with water to form 5% concentration lipase solution.
The wash liquor was prepared by diluting 2 g of detergent composition in 1 liter of water. After the full dissolution of the detergent composition, 1 mg of rinse aid was added to the wash liquor. Various contacting time, 30, 60 and 90 minutes was used, before the Ross-Miles foam measurement. The foam height was measured at the initial time, 1, 2, 3, 4, and 5 minutes.
As can be seen from Table 2, significant foam height reduction was observed for all the contacting times and through-out the whole Ross-Miles foam measurement for composition 1, but not for composition A.
These Examples investigated the effect on the wash liquor containing an alkoxylated ester surfactant of rinse aid without an enzyme (Comparative Example B) and rinse aid with enzyme other than carboxylate ester hydrolase (Comparative Examples C) and rinse aid containing carboxylate ester hydrolase in Examples 2 to 5 (within the scope of this invention). The same detergent composition was used for all examples. The detergent composition was prepared following the same procedure described for Example 1. The rinse aid for these examples were 100% “as is” concentration enzymes thus no preparation was needed.
The wash liquor was prepared by diluting 2 g of detergent composition in 1 liter of water. After the fully dissolution of the detergent composition, various amounts of rinse aid were added to the wash liquor. Various contacting time were used, before the Ross-Miles foam measurement. The foam height was measured at the initial time, 1, 3, and 5 minutes.
As can be seen from the results in Table 3, Comparative Examples B and C did not effect foam reduction, despite high Savinase® concentration in Comparative Example C. On the other hand Examples 2 to 5 all showed drastic reduction in foam height.
