RU2179999C2 - Washing condition facilitating liquid and gel-like dishwashing detergent compositions with controlled ph value and required foaming and food soiling- removal characteristics - Google Patents

Abstract

FIELD: detergents. SUBSTANCE: compositions suitable for manual washing of cooking ware 20-40% anionic surfactant such as alkylester-sulfate, 3-10% nonionic surfactant such as fatty C_8-18-polyhydroxyacid amides, 2-6% foam enhancer and stabilizer, 45-75 aqueous liquid carrier, and 0.2-6% pH-control agent. Compositions are characterized by being free of any calcium or magnesium sources. EFFECT: increased heat resistance. 4 cl, 2 ex

Description

 The present invention relates to liquid or gel dishwashing detergent compositions suitable for use in manual dishwashing. Such formulations contain detergent surfactants, foam enhancers, pH control agents, and other auxiliary additives, which in combination serve to impart consumer-preferred characteristics to such dishwashing detergent pricing and cleaning products from food contaminants.

BACKGROUND OF THE INVENTION
Facilitative Drainage (LDL) detergent formulations used for washing dishes by hand are well known in the art. Such products are usually formulated to provide a wide variety of characteristics and aesthetic properties and qualities. First of all, liquid or gel dishwashing products should be composed of types and amounts of surfactants and other cleaning auxiliary additives that will provide acceptable solubility and removal of food contaminants, in particular fatty contaminants from dishes to be cleaned or in aqueous solutions formed from such products .

 Heavily soiled dishes can be particularly difficult during manual dishwasher operations. Items such as plates, dishes, pots, pans and the like can be heavily soiled in the sense that relatively large amounts of food contaminants and residues can still be found on the dishes at a time when such dirty dishes must be washed by hand. Dishes may also be heavily soiled in the sense that food contaminants stick particularly sticky or stick to the surface of the dishes that must be washed. This may be the result of the type of food contamination present or the nature of the included surfaces of the dishes. Remains of sticky food contaminants may also be the result of the type of cooking operations to which contaminated dishes were subjected.

 When heavily soiled dishes must be washed by hand, very concentrated or highly concentrated dishwashing detergent products are often used. Often this will involve the direct application of a liquid or gel product in undiluted or pure form to soiled dishes. During such applications, the pH characteristics of the dishwashing composition can significantly affect the ability of the composition to dissolve and remove foodborne contaminants such as fat contaminants. In addition, the pH of the product can determine the effectiveness of conventional aqueous dishwashing solutions in the removal of grease from dishes. In general, aqueous dishwashing solutions, which are more alkaline in nature, are more effective in removing such contaminants.

 In addition to the fact that they are used for cleaning dishes, LDL or gel formulations will also be desirable to have other characteristics that enhance the aesthetics or consumer perception of the effectiveness of manual dishwashing. Thus, in liquids or gels used for washing dishes by hand, substances that increase the foaming characteristics of washing solutions formed from such products should also be used. The characteristics of foaming entail both the receipt of an initially suitable amount of foam in the wash water, and the formation of foam, which is well preserved during washing.

 Based on the foregoing, there is a constant need for the formulation of liquids or gels for washing dishes by hand, which provide an acceptable and required balance between the aesthetics of the product and the cleaning characteristics both in direct use in concentrated form and in an aqueous washing solution. Thus, it is an object of the present invention to provide a light washing regimen for liquid or gel dishwashing compositions that are particularly effective in removing food contaminants from dirty dishes when such compositions are used in a manual dishwashing situation.

 The next objective of the present invention is the development of such compositions that have the desired pH value for use either in direct application to dishes or in aqueous solutions for washing dishes.

 The next objective of the present invention is the implementation of such compositions that provide suitable and required pricing characteristics.

 It has been found that a certain selected combination of surfactants, foam enhancers, pH controlling agents and other auxiliary substances can be made to provide dishwashing compositions with which the above objectives are achieved. Elements of these selected combinations of ingredients are described below.

Summary of the invention
The present invention relates to aqueous pH-facilitating washing liquid or gel detergent compositions with controlled pH, having especially desirable characteristics for removing contaminants and foaming when such compositions are used to clean heavily soiled dishes. Such formulations contain: A) from about 20 to 40% of a certain type of anionic surfactant component; C) from about 3 to 10% of a particular type of nonionic surfactant component; C) from about 2 to 6% foam enhancer / stabilizer; D) from about 45 to 75% aqueous liquid carrier; E) from about 0.2 to 6% pH of a control agent, such as sodium carbonate, which is effective for adjusting the pH of a 10% aqueous solution of the composition in the range from 9 to 11.

 The anionic surfactant component essentially contains alkyl ether sulfates containing from about 8 to 18 carbon atoms in the alkyl group. Such alkyl ether sulfates also contain from about 1 to 6 moles of ethylene oxide per molecule.

The non-ionic surfactant component essentially includes amides of fatty C _8-18 polyhydroxy acids. In nonionic surfactants, such amides of polyhydroxy fatty acids can also be combined with from about 0.2 to 2% of the composition of a nonionic joint surfactant (co-surfactant). This non-ionic co-surfactant is selected from ethoxylates of C _8-18 alcohols having from about 1 to 15 moles of ethylene oxide, surfactants based on a block copolymer of ethylene oxide propylene oxide, and combinations of these non-ionic co-surfactants.

The foam enhancers / stabilizers used in the compositions of the present invention are selected from betaine surfactants, hydroxide free fatty acid amides, amine oxide semi-polar nonionic surfactants and C _8-22 alkyl polyglycosides. Combinations of such foam enhancers / stabilizers may also be used.

 The above essential components, as well as a number of additional optional ingredients, can be combined in a convenient way with the formation for easy washing of liquid or gel dishwashing detergent products of the present invention. One type of ingredient that is commonly used in dishwashing detergent products, but which should not be used in the relatively high pH formulations of the present invention, includes any source of calcium or magnesium ions.

DETAILED DESCRIPTION OF THE INVENTION
For a light washing regime, the liquid or gel dishwashing detergent compositions of the present invention contain five essential components. These components are:
(1) a specific type of anionic surfactant;
(2) certain non-ionic surfactants;
(3) specific foam enhancers / stabilizers;
(4) an aqueous liquid carrier; and
(5) pH controlling agent.

 A wide variety of optional ingredients can be added to improve the operational, rheological and / or aesthetic characteristics of the compositions of the present invention.

 The following are described in detail the essential optional components of these facilitating washing regimen liquid or gel dishwashing detergents along with the production and use. When describing the compositions of the present invention, it should be noted that the term "facilitating washing mode dishwashing detergent composition", as used here, refers to those compositions that are used in the manual method of washing dishes (i.e. hands). Such compositions are naturally highly soap or foaming agents. When describing the compositions of the present invention, it should also be noted that all concentrations and ratios are given in a weight ratio, unless otherwise indicated.

Anionic Surfactant Component
The compositions of the present invention essentially contain from about 20 to 40% anionic surfactants. More preferably, the anionic surfactant component comprises from about 25 to 35% of the compositions of the present invention.

The anionic surfactant component essentially includes alkyl ether sulfates. Alkyl ether sulfates are also known as alkyl polyethoxylated sulfates. These ethoxylated alkyl sulfates are those which correspond to the formula
R'-O- (C ₂ H ₄ O) _n SO ₃ M
in which R 'represents an alkyl group C _8-18 , n is from about 1 to 6 and M represents a salt-forming cation. Preferably, R ′ is an alkyl group of C _10-16 , n is from about 1 to 4, and M is sodium, potassium, ammonium, alkylammonium, or alkanolammonium. Most preferably, R ′ is C _12-16 , n is from about 1 to 3, and M is sodium. Alkyl ether sulfates are usually used in the form of mixtures containing variable radical chain lengths R 'and variable degrees of ethoxylation. Often, such mixtures inevitably contain some non-ethoxylated alkyl sulfate substances, i.e. surfactants with the above formula for ethoxylated alkyl sulfates, where n = 0.

Nonionic Surfactants
The compositions of the present invention also essentially contain from about 3 to 10% of a certain type of non-ionic surfactant component. More preferably, the nonionic surfactant component comprises from about 4 to 6% of the compositions of the present invention.

в которой R' представляет собой H, C₁-C₄ углеводородный радикал, 2-гидроксиэтил или их смесь; R² представляет собой C₈-C₁₈ углеводородный радикал; и Z представляет собой полигидроксиуглеводородный радикал, имеющий линейную углеводородную цепь, с, по крайней мере, 3 гидроксилами, непосредственно присоединенными к цепи, или его алкоксилированное производное. Примеры таких поверхностно-активных веществ включают С₁₀-С₁₈ N-метил-, или N-гидроксипропил, глюкамиды. От N-пропил до N-гексил C₁₂-C₁₆ глюкамиды могут быть использованы для более низкой характеристики ценообразования. Амиды жирных полигидроксикислот предпочтительно включают от примерно 3 до 5% составов настоящего изобретения.One significant type of nonionic surfactant that is present in the compositions of the present invention includes fatty amides of C _8-18 polyhydroxy acids. These substances are more fully described in Pan / Gosselink; US patent 5332528, issued July 26, 1994, which are incorporated into this description by reference. These amides of polyhydroxy fatty acids have the general structural formula

in which R 'represents H, C ₁ -C ₄ hydrocarbon radical, 2-hydroxyethyl or a mixture thereof; R ² represents a C ₈ -C ₁₈ hydrocarbon radical; and Z is a polyhydroxy hydrocarbon radical having a linear hydrocarbon chain with at least 3 hydroxyls directly attached to the chain, or an alkoxylated derivative thereof. Examples of such surfactants include C ₁₀ -C ₁₈ N-methyl-, or N-hydroxypropyl, glucamides. N-propyl to N-hexyl C ₁₂ -C ₁₆ glucamides can be used for lower pricing characteristics. Amides of polyhydroxy fatty acids preferably comprise from about 3 to 5% of the compositions of the present invention.

 In the non-ionic surfactant component of the compositions of the present invention, the amides of the polyhydroxy fatty acids described above can be combined with some other types of non-ionic co-surfactants. These other types include ethoxylated alcohols and surfactants based on a block copolymer of ethylene oxide propylene oxide, as well as combinations of these types of nonionic co-surfactants.

Ethoxylated alcohol surfactants used in the nonionic surfactant component of the present invention are those that correspond to the general formula
R ^l -O- (C ₂ H ₄ O) _n SO ₃ M
in which R ¹ represents a C ₈ -C ₁₈ alkyl group, and n varies from about 1 to 15.

 Preferably, R ′ is an alkyl group, which may be primary or secondary, and containing from about 9 to 15 carbon atoms, more preferably from about 10 to 14 carbon atoms. Preferably, ethoxylated fatty alcohols contain from about 2 to 12 ethylene oxide moieties per molecule, more preferably from about 8 to 12 ethylene oxide moieties per molecule. Non-ionic co-surfactants based on ethoxylated fatty alcohol will often have a hydrophilic-lipophilic balance (HLB) ranging from about 6 to 15, most preferably from about 10 to 15.

Examples of fatty alcohol ethoxylates used as nonionic co-surfactant compositions of the present invention include those derived from alcohols with 12-15 carbon atoms and which contain about 7 moles of ethylene oxide. Such substances are commercially available from Shell Chemical Company under the trademarks Neodol 25-7 and Neodol 25-6.5. Other used Neodola include Neodol 1-5, an ethoxylated fatty alcohol with an average of 11 carbon atoms in its alkyl chain with about 5 moles of ethylene oxide; Neodol 23-9, an ethoxylated C ₁₂ -C ₁₃ primary alcohol having about 9 moles of ethylene oxide, and Neodol 91-10, an ethoxylated C ₉ -C ₁₃ primary alcohol having about 10 moles of ethylene oxide. Alcohol ethoxylates of this type are also sold by Shell Chemical Company under the brand name Dobanol. Dobanol 91-5 is an ethoxylated C ₉ -C ₁₁ fatty alcohol with an average of 5 moles of ethylene oxide, Dobanol 25-7 is an ethoxylated C ₁₂ -C ₁₅ fatty alcohol with an average of 7 moles of ethylene oxide per mole of fatty alcohol.

Other examples of suitable non-ionic ethoxylated alcohol surfactants include Tergitol 15-S-7 and Tergitol 15-S-9, both of which are secondary alcohol ethoxylates and are commercially available from Union Carbide Corporation. The first is a mixed ethoxylation product of a C ₁₁ -C ₁₅ linear secondary alkanol with 7 moles of ethylene oxide, and the second is a similar substance, but with 9 moles of reacted ethylene oxide.

 Other types of non-ionic surfactants based on alcohol ethoxylates used in the present compositions are non-ionic surfactants with a higher molecular weight, such as Neodol 45-11, which are similar to the condensation products of ethylene oxide with more fatty alcohols, and the more fatty alcohol has 14-15 carbon atoms and the number of ethylene oxide groups per mole is about 11. Such materials are also commercially available from Shell Chemical Company.

 Non-ionic co-surfactants based on ethoxylated alcohol often comprise from about 0.2 to 2% of the compositions of the present invention. More preferably, such ethoxylated alcohols comprise from about 0.5 to 1.5% of the compositions.

 Another type of nonionic co-surfactant suitable for use in combination with fatty polyhydroxy acid amides in the nonionic surfactant component of the present invention includes ethylene oxide propylene oxide block copolymers that function as polymeric surfactants. Such block copolymers include one or more hydrophobic groups. Containing mainly ethylene oxide fragments, and one or more hydrophobic groups containing mainly propylene oxide fragments. Such groups are attached to the residue of a compound that contains one or more hydroxy groups or amino groups. Such polymeric surfactants have a molecular weight ranging from about 400 to 60,000, more preferably from 4,000 to 6,000.

Preferred ethylene oxide propylene polymer surfactants are those in which the propylene oxide is condensed with an amine, especially a diamine, to give a base, which is then condensed with ethylene oxide. Substances of this type are sold under the trade name Tetronic ^® . Similar structures wherein the ethylene diamine is replaced with a polyol such as propylene glycol, sold under the tradename Pluronic ^®. Preferred ethylene oxide propylene oxide (EO-PO) polymeric surfactants have an HLB that ranges from about 4 to 30, more preferably from about 10 to 20.

 The ethylene oxide propylene oxide block copolymers used in the present invention are described similarly in Pancheri / Mao; US patent 5167872, issued December 2, 1992. This patent is incorporated into the description by reference.

 Ethylene oxide propylene oxide block copolymers are often present in the range of about 0.15 to 2% of the compositions of the present invention. More preferably, these polymeric surfactants comprise from about 0.2 to 0.8% of the compositions of the present invention.

Foam Enhancers / Stabilizers
The compositions of the present invention further comprise from about 2 to 6%, preferably from about 3 to 6%, a foam enhancer or stabilizing agent such as betaine surfactants, hydroxy-free fatty acid amides, amine oxide semi-polar nonionic surfactants and C _8-22 alkyl polyglycosides. Combinations of such foam enhancers / stabilizers may also be used.

в которой R представляет собой гидрофобную группу, выбранную из алкильных групп, содержащих от примерно 10 до примерно 22 атомов углерода, предпочтительно от примерно 12 до 18 атомов углерода, алкиларильные и арилалкильные группы, содержащие аналогичное число атомов углерода, с бензольным кольцом, рассматриваемым как эквивалент примерно 2 атомам углерода, и с аналогичными структурами, разрываемыми амидо- или простыми эфирными связями; каждый R¹ представляет собой алкильную группу, содержащую от 1 до примерно 3 атомов углерода; и R² представляет собой алкиленовую группу, содержащую от 1 до примерно 6 атомов углерода.Betaine surfactants used as foam enhancers in the present invention have the general formula

in which R represents a hydrophobic group selected from alkyl groups containing from about 10 to about 22 carbon atoms, preferably from about 12 to 18 carbon atoms, alkylaryl and arylalkyl groups containing the same number of carbon atoms, with a benzene ring considered as equivalent about 2 carbon atoms, and with similar structures cleaved by amido or ether bonds; each R ¹ represents an alkyl group containing from 1 to about 3 carbon atoms; and R ² represents an alkylene group containing from 1 to about 6 carbon atoms.

 Examples of preferred betaines are dodecyldimethyl betaine, cetyldimethyl betaine, dodecylamidopropyl dimethyl betaine, tetradecyldimethyl betaine, tetradecylamidopropyl dimethyl betaine and dodecyldimethylammonium hexanoate. Other suitable amidoalkyl betaines are described in US Pat. Nos. 3,950,417; 4,137,191 and 4,375,421 and in British Patent 2103236, all of which are incorporated herein by reference.

Hydroxy-free amide-based surfactants used as foam enhancers in the present invention include ammonia, monoethanol and diethanolamides of fatty acids having an acyl group that contains from about 3 to about 18 carbon atoms. Such substances are characterized as “hydroxy-free” in order to distinguish them from fatty polyhydroxy acid amides essentially used in the nonionic surfactant component described above. Thus, "hydroxy-free" amides for the purposes of the present invention are those in which the acyl group does not contain hydroxyl substituents. Such substances are represented by the formula
R ₁ -CO-N (H) _m-1 (R ₂ OH) _3-m
in which R ₁ represents a saturated or unsaturated, hydroxy-free aliphatic carbon group having from about 7 to 21, preferably from about 11 to 17 carbon atoms; R ₂ represents a methylene or ethylene group; and m is 1, 2 or 3, preferably 1. Specific examples of such amides are coconut fatty acid monoethanolamine and fatty acid diethanolamine indodecylamide. These acyl groups can be obtained from naturally occurring glycerides, for example, from coconut oil, palm oil, soybean oil and hard fat, but can be synthetically obtained, for example, by oxidation of oil or by hydrogenation of carbon monoxide by the Fischer-Tropsch method. Monoethanolamides and C _12-14 fatty acid diethanolamides are preferred.

в которой R₁ представляет собой алкил, 2-гидроксиалкил, 3-гидроксиалкил или 3-алкокси-2-гидроксипропил, в котором алкил и алкокси, соответственно, содержат от примерно 8 до примерно 18 атомов углерода, R₂ и R₃ каждый представляет собой метил, этил, пропил, изопропил, 2-гидроксиэтил или 3-гидроксипропил, и n равно от 0 до примерно 10. Особенно предпочтительными являются оксиды аминов с формулой

в которой R₁ представляет собой C_12-16 алкил, и R₂ и R₃ представляют собой метил или этил. Вышеупомянутые гидрокси-свободные амиды и оксиды аминов более полно описываются в патенте США 4316824, включенном в описание в виде ссылки.The amine oxide semi-polar non-ionic surfactants used as foam enhancers include compounds or mixtures of compounds having the formula

in which R ₁ represents alkyl, 2-hydroxyalkyl, 3-hydroxyalkyl or 3-alkoxy-2-hydroxypropyl, in which alkyl and alkoxy, respectively, contain from about 8 to about 18 carbon atoms, R ₂ and R ₃ each represents methyl, ethyl, propyl, isopropyl, 2-hydroxyethyl or 3-hydroxypropyl, and n is from 0 to about 10. Particularly preferred are amine oxides of the formula

in which R ₁ represents C _12-16 alkyl, and R ₂ and R ₃ represent methyl or ethyl. The aforementioned hydroxy-free amides and amine oxides are more fully described in US Pat. No. 4,316,824, incorporated herein by reference.

Other surfactants suitable for use as foam enhancers / stabilizers in the compositions of the present invention are nonionic fatty alkyl polyglycosides. Such substances have the formula
R ₂ O (C _n H _2n O) _y (Z) _x
in which Z is derived from glucose, R ² represents a hydrophobic group selected from alkyl, alkylphenyl, hydroxyalkylphenyl and mixtures thereof, wherein said alkyl groups contain from 8 to 22, preferably from 12 to 14 carbon atoms; n is 2 or 3, preferably 2; y is from 0 to 10, preferably 0; and x is from 1.5 to 8, preferably from 1.5 to 4, most preferably from 1.6 to 2.7. US patents 4,393,203 and 4,732,704, incorporated by reference, describe these alkyl polyglycoside surfactants.

Aqueous liquid carrier
Facilitating the washing regime, the dishwashing detergent compositions of the present invention further comprise from about 45 to 75% aqueous liquid carrier, in which other essential and optional components of the compositions are dissolved, dispersed or suspended. More preferably, the aqueous liquid carrier comprises from about 50 to 65% of the compositions of the present invention.

 One essential component of an aqueous liquid carrier is, of course, water. However, the aqueous liquid carrier may contain other substances which are liquid or which dissolve in the liquid carrier at room temperature and which may also serve as some other function besides the function of a simple filler. Such substances may include, for example, hydrotropic substances, solvents and electrolytes to stabilize the phase.

a) Hydrotropic substances
An aqueous liquid carrier may contain one or more substances that are hydrotropic substances. Hydrotropic substances suitable for use in the compositions of the present invention include C ₁ -C ₃ alkylaryl sulfonates, C ₆ -C ₁₂ alkanols, C ₁ -C ₈ sulfates and carboxylic acid sulfonates, urea, C ₁ -C ₆ hydrocarboxylates, C ₁ -C ₄ carboxylates, C ₂ -C ₄ organic dibasic acids and mixtures of these hydrotropic substances.

Suitable C ₁ -C ₃ alkylaryl sulfonates include sodium, potassium and ammonium xylene sulfonates; sodium, potassium and ammonium toluenesulfonates; sodium, potassium and ammonium cumene sulfonates and substituted and unsubstituted sodium, potassium and ammonium naphthalenesulfonates and mixtures thereof.

Suitable C ₁ -C ₈ sulfate or sulfonate salts of carboxylic acids are any water-soluble salts of organic compounds containing 1-8 carbon atoms (not counting substituent groups) that are substituted with sulfate or sulfonate and have at least one carboxyl group. The substituted organic compound may be cyclic, acyclic or aromatic, i.e. benzene derivatives. Preferred alkyl compounds have from 1 to 4 carbon atoms substituted with sulfate or sulfonate, and from 1 to 2 carboxyl groups. Examples of hydrotropic substances of this type include salts of sulfosuccinic, sulfophthalic, sulfoacetic and m-sulfobenzoic acids and diester sulfosuccinates, preferably sodium or potassium salts, as described in US Pat. No. 3,915,903.

Suitable C ₁ -C ₆ hydrocarboxylates and C ₁ -C ₄ carboxylates for use in the present invention include acetates, propionates and citrates. Suitable C ₂ -C ₄ diacids for use include succinic, glutaric and adipic acids. Other compounds that produce hydrotropic effects suitable for use in the present invention as hydrotropic substances include C ₆ -C ₁₂ alkanols and urea.

 Preferred hydrotropic substances for use in the present invention are sodium, potassium and ammonium cumene sulfonate; sodium, potassium and ammonium xylene sulfonate; sodium, potassium and ammonium toluenesulfonate and mixtures thereof. Most preferred are sodium cumene sulfonate and sodium xylene sulfonate, and mixtures thereof. These preferred hydrotropic substances may be present in the composition in the range of from about 3 to 8% by weight.

b) Solvents
A number of water miscible liquids, such as lower alkanols, diols, other polyols, ethers, amines and the like, can be used as part of an aqueous liquid carrier. Particularly preferred are C _1-4 alkanols. Such solvents may be present in the compositions from about 3 to 8%.

c) Electrolytes
A number of water-soluble salts can be used as an electrolyte in a component of an aqueous liquid carrier of the compositions of the present invention. These include salts such as sodium chloride, potassium chloride, sodium citrate, sodium acetate, sodium sulfate, potassium sulfate and the like. Most preferably, the electrolyte is sodium or potassium chloride.

 If used, electrolytes can comprise from about 2.5 to 8% of the composition. More preferably, the electrolyte is used in the compositions of the present invention in an amount of from about 1.5 to 4.5%.

PH Control Agents
Alkaline pH products and alkaline aqueous dishwashing solutions formed from them, which contain a particular combination of surfactants of the compositions of the present invention, are particularly effective in removing grease from dishes, especially from heavily soiled dishes. Thus, the compositions of the present invention essentially contain a pH controlling agent that is sufficient to maintain the pH of a 10% aqueous solution of the composition in the range of 9 to 11. More preferably, the compositions of the present invention are more alkaline in nature with a pH of 10% solution of 10 , 0 to 10.5.

 It is particularly preferred that the pH control agent is capable of maintaining the pH of dilute solutions containing the aqueous dishwashing solutions of the present invention. Preferably, the pH control agent is effective in maintaining the pH of a 3% aqueous solution of the composition in the range of from about 9.5 to about 10.8, preferably from about 9.8 to about 10.5. Even more preferably, the pH controlling agent is effective to maintain the pH of a 0.3% aqueous solution of the composition in the range of from about 9.8 to about 11.0, preferably from about 10.0 to about 11.0.

 The pH controlling agent used to provide the required pH characteristics for the dishwashing detergents of the present invention can be any low molecular weight organic or any organic substance that provides alkalinity. Useful inorganic salts include water-soluble carbonates, bicarbonates, borates, phosphates, chlorides or silicates. Useful organic substances with additional alkalinity include alkanolamines. Highly preferred pH controlling agents include alkali metal carbonates, in particular sodium or potassium carbonate.

 The pH controlling agent is usually present in the compositions of the present invention at a level of from about 0.2 to 6%, preferably from about 2 to 5%, by weight of the composition.

Avoidance of divalent metal ions
The alkaline nature of the liquid dishwashing detergent compositions of the present invention creates the need to avoid introducing ions of any divalent metals that can form hydroxide precipitates under pH conditions specified for the liquid detergent products of the present invention. Thus, the compositions of the present invention are usually essentially free of any source of calcium and / or magnesium ions. This is true even if sources of calcium and / or magnesium ions are usually included in lower pH liquid dishwashing formulations.

Improved temperature stability
The liquid dishwashing detergent compositions of the present invention having a particularly desirable stability at high and / or low temperature can be obtained by selecting certain types and amounts of components from the above. By using potassium salts from the electrolyte and / or the pH of the control agent, product stability at room and high temperatures can be improved since such potassium salts have a reduced tendency to form visible precipitates at higher temperatures. When using relatively lower concentrations of anionic surfactants, that is, concentrations of about 31% or lower, the tendency of the surfactant system to form visible precipitates at lower temperatures is reduced.

Optional ingredients
Preferred optional ingredients in the dishwashing compositions of the present invention include auxiliary surfactants, enzymes such as a protease, an enzyme stabilizing system, and thickeners. These and other optional ingredients are described below.

a) Auxiliary surfactants
The compositions of the present invention may contain a wide variety of auxiliary surfactants in addition to the substantially used surfactants described above. Such auxiliary surfactants, for example, may include C _8-22 alkyl sulfates; C _9-15 alkylbenzenesulfonates; C _8-22 olefinsulfonates; C _8-22 paraffinsulfonates; C _8-22 alkyl glyceryl ether sulfonates; fatty acid ester sulfonates; sulfates of secondary alcohols; C _12-16 alkylethoxycarboxylates; C _11-16 secondary soaps; ampholytic detergent surfactants; and zwitterionic detergent surfactants.

b) Protease and / or other enzymes
The compositions of this invention may also optionally contain from about 0.001 to about 5%, more preferably from about 0.003 to about 4%, most preferably from about 0.005 to about 3%, by weight of the active protease, i.e., the proteolytic enzyme. Protease activity may decrease expressed by Anson (AU) per kilogram of detergent composition. It has been found that levels from 0.01 to about 150, preferably from about 0.05 to about 80, most preferably from about 0.1 to about 40 AU per kilogram, are acceptable in the compositions of the present invention.

 Useful proteolytic enzymes may be of animal, plant origin, or from microorganisms (preferred). Bacterial serine proteolytic enzyme is more preferred. Purified or untreated forms of this enzyme may be used. Proteolytic enzymes obtained by chemically or genetically modified mutants are included by definition, since they are close structural variations of the enzyme. Particularly preferred is a bacterial serine proteolytic enzyme derived from Bacillus subtilis and / or Bacillus licheniformis.

Suitable proteolytic enzymes include Novo Industry A / S Alcalase ^{® (preferred), Esperase ®, Savinase ® (} Copenhagen, Denmark), Gist-brocades Maxatase ®, Maxacal ®, and Maxapem 15® (protein engineered method Maxacal ^® (Delft, Netherlands ) and subtilisin BPN (preferably), which are commercially available. Preferred proteolytic enzymes are also modified bacterial sarin proteases, such as those obtained by Genencor International, Inc. (San-Francisco, California), which are described in European patent EP-B-251446, Issued December 28, 1994 and published January 7, 1998 (Os (pages 17, 24, and 98), which are also referred to (here) as “protease B.” US Patent 5,030,378, Ventgas, issued July 9, 1991, refers to a modified genencor International bacterial serine proteolytic enzyme called “protease A” in the present specification (same as BPN.) In particular, see columns 2 and 3 of US Pat. No. 5,030,378 for a full description including the amino sequence of protease A and its variations. Preferred proteolytic enzymes are selected from then group consisting of ^{Alcalase ® (Novo Industri A / S} ) BPN, Protease A and Protease B, and mixtures thereof. Protease B is most preferred.

 Another preferred protease, called “protease D”, is a variant of a carbonyl hydrolase that has an amino acid sequence not found in nature and which is obtained from a carbonyl hydrolase precursor by substituting another amino acid for a plurality of amino acid residues at a position at said carbonyl hydrolase of the equivalent position +76, preferably also in combination with one or more positions of the amino acid residue equivalent to positions selected from the group consisting of +99, +101, +103, +104, +107, +123, +27, +105, +109, + 126, +128, +135, +156, +166, +195, +197, +204, +206, +210, +216, +217, +218, +222, +260, +265 and / or + 274, in accordance with the numbering of subtilisin of Bacillus amiloliquefaciens, as described in WO 9510615, published April 20, 1995 by Genencor International.

 Useful proteases are also described in PCT Publications: WO 95/30010 published November 9, 1995 by the Procter and Gamble Company.

 Other optional enzymes, such as lipase and / or amylase, may also be added to the compositions of the present invention for further purification.

c) Enzyme stabilization system
Preferred compositions of the present invention may further include an enzyme stabilization system from about 0.001 to about 10%, preferably from about 0.005 to about 8%, most preferably from about 0.01 to about 6% by weight. The enzyme stabilization system may be any stabilizing system that is compatible with the protease or other enzymes used in the compositions of the present invention. Such stabilizing systems may include boric acid, propylene glycol, short chain carboxylic acid, boronic acid, polyhydroxy compounds and mixtures thereof such as those described in US Pat. Nos. 4,261,868 to Nora et al, issued April 14, 1981; 4,404,115, Tai, issued September 13, 1983; 4,318,818, Letton et al; 4,243,543, Guildert et al, issued January 6, 1981; 4462922, Boskamp, issued July 31, 1984; 4532064, Boskamp, issued July 30, 1985; 4537707, Severson Jr., issued August 27, 1985, all of which are incorporated herein by reference.

 In addition, chlorine and oxygen bleach scavengers from 0 to about 10%, preferably from about 0.01 to about 6% by weight, can be added to the compositions of the present invention to prevent degradation and inactivation of enzymes by compounds present in many water sources, especially in alkaline conditions. Although the chlorine levels in the water may be small, typically in the range of from about 0.5% ppm to about 1.75% ppm, the available chlorine in the total amount of water in contact with the enzyme when washing dishes is usually big; accordingly, the stability of the enzyme in use can be problematic.

 Suitable chlorine-absorbing anions are salts containing ammonium cations. They can be selected from the group consisting of reducing substances like sulfite, bisulfite, thiosulfite, thiosulfate, iodide and so on, antioxidants like carbonate, ascorbate and so on, organic amines such as ethylenediaminetetraacetic acid (EDTA) or its alkali metal salts and monoethanolamine (MEA) and mixtures thereof.

d) Thickener
Dishwashing detergent compositions of the present invention may also contain a thickening agent. Many suitable thickening agents are known in the art. A preferred thickener for use in the compositions of the present invention is hydroxypropyl methylcellulose.

The hydroxypropyl methylcellulose-based polymer has an average molecular weight of from about 50,000 to 125,000 and a viscosity of 2 wt.% Aqueous solution at 25 ^{° C.} (ADTMD2363) of from about 50,000 to about 100,000 cps. An especially preferred hydroxypropyl cellulose-based polymer is Methocel ^® J75MS-N, 2 wt.% Aqueous solution of which at 25 ^o C has a viscosity of about 75,000 cps. Particularly preferred hydroxypropyl cellulose polymers have a surface treated so that the hydroxypropyl cellulose polymer is readily dispersible at 25 ^{° C.} in an aqueous solution having a pH of at least about 8.5.

When a thickener, such as a hydroxypropylmethyl cellulose polymer, is incorporated into the dishwashing detergent compositions of the present invention, it gives the detergent composition a Brookfield viscosity of from about 500 to 3500 cps at 25 ^° C. More preferably, a hydroxypropyl methyl cellulose material is used to give a viscosity of about 1000 up to 3000 centipoise at 25 ^o C. For the purposes of the present invention, the viscosity was measured with a Brookfield LVTDV-11 viscometer using an RV # 2 spindle at 12 rpm.

 The dishwashing detergent compositions of the present invention may contain from about 0.2 to 2% of a thickener, in particular a hydroxypropyl methylcellulose thickener.

e) Various optional ingredients
Other traditional optional ingredients that are typically used at additional levels below about 5% include opacifiers, antioxidants, bactericides, colorants, flavors, and the like. In addition, detergent modifying additives may also be present in the compositions of the present invention in amounts of from 0 to about 50%, preferably from about 2 to about 30%, most preferably from about 5 to about 15%. Typically, a detergent modifier is not present in facilitating a washing regimen of liquid or gel dishwashing detergent compositions. However, even if sources of calcium and magnesium ions are excluded from the compositions of the present invention, some compositions may contain trace amounts of magnesium or calcium ions in the form of impurities. Such formulations may require the additional presence of low levels, preferably from 0 to about 10%, more preferably from about 0.5 to about 3%, of chelating agents selected from the group consisting of bicin / bis (2-ethanol) blitsin, citrate N - (2-hydroxyethyl) iminodiacetic acid (HIDA) N- (2,3-dihydroxy-propyl) -diethanolamine, 1,2-diamino-2-propanol-N, N-tetramethyl-1,3-diamino-2-propanol , N, N-bis (2-hydroxyethyl) glycine (also called bicin) and N-tris- (hydroxymethyl) methylglycine (and also called tricin). Mixtures of any of the above are also acceptable.

Getting composition
The liquid or gel dishwashing detergent compositions of the present invention can be prepared by combining the essential and optional ingredients together in any convenient manner using suitable mixing to form a homogeneous product. Preferred methods for preparing the disclosed type of detergent compositions and for preparing various components of such compositions are described in detail in Ofosu-Asante: US 5474710, issued December 12, 1995, incorporated herein by reference.

The way to wash dishes
Dirty dishes may come into contact with an effective amount of the detergent composition of the present invention, typically from about 0.5 to about 20 ml (per 25 items of processed dishes), preferably from about 3 to about 10 ml. The actual amount of liquid detergent composition used is based on the user's judgment and typically depends on factors such as the particular formulation composition, including the concentration of the active ingredients of the composition, the amount of dirty dishes to be cleaned, the degree of contamination of the dishes, and the like. The specific recipe, in turn, depends on a number of factors, such as the market for the composition (for example, USA, Europe, Japan, and so on). The following are examples of typical methods in which the detergent compositions of the present invention can be used to clean dishes. These examples are for illustrative purposes, but are not intended to limit the scope of the invention.

 In a typical US application, about 3 to about 15 ml, preferably about 5 to about 10 ml of a liquid detergent composition with about 1000 to about 10,000 ml, more typically about 3,000 to about 5,000 ml of water in a sink having a volumetric capacity, are combined. in the range of from about 5,000 to about 20,000 ml, more typically from about 10,000 to about 15,000 ml. The detergent composition has a surfactant mixture concentration of from about 21 to about 44% by weight, preferably from about 25 to about 40% by weight. Dirty dishes are immersed in a sink containing a detergent composition and water, in which they are cleaned by contacting the dirty surface of the dishes with a cloth, sponge, or similar item. A cloth, sponge, or the like can be immersed in the detergent composition and the aqueous mixture until it comes into contact with the surface of the dishes, and is usually contacted with the surface of the dishes for about 1 to about 10 seconds, although the actual time varies with each application and user. The contact of a fabric, sponge or similar object with the surface of the dishes is preferably accompanied by parallel friction of the surface of the dishes.

In a typical European market application, from about 3 to about 15 ml, preferably from
about 3 to about 10 ml of a liquid detergent composition with from about 1000 to about 10,000 ml, more typically from about 3,000 to about 5,000 ml of water in a sink having a volumetric capacity in the range of from about 5,000 to about 20,000 ml, more typically from about 10,000 to approximately 15,000 ml. The detergent composition has a surfactant mixture concentration of from about 20 to about 50% by weight, preferably from about 30 to about 40% by weight. Dirty dishes are immersed in a sink containing a detergent composition and water, in which they are cleaned by contacting the dirty surface of the dishes with a cloth, sponge, or similar item. A cloth, sponge, or the like can be immersed in the detergent composition and the aqueous mixture until it comes into contact with the surface of the dish and is usually contacted with the surface of the dish for about 1 to 10 seconds, although the actual time varies with each use and by the user. The contact of a fabric, sponge or similar object with the surface of the dishes is preferably accompanied by parallel friction of the surface of the dishes.

 In a typical Latin American market application, from about 1 to about 50 ml, preferably from about 2 to about 10 ml of detergent composition are combined with from about 50 to about 2000 ml, more typically from about 100 to about 1000 ml of water in a bowl having a volumetric capacity from about 500 to about 5000 ml, more typically from about 500 to about 2000 ml. The detergent composition has a surfactant mixture concentration of from about 5 to about 40% by weight, preferably from about 10 to about 30% by weight. Dirty dishes are cleaned by contacting the dirty surface of the dishes with a cloth, sponge, or similar item. A cloth, sponge or similar object can be immersed in a detergent composition and water mixture until it comes into contact with the surface of the dishes and is usually contacted for a period of about 1 to 10 seconds, although the actual time varies with each application and user. The contact of a fabric, sponge or similar object with the surface of the dishes is preferably accompanied by parallel friction of the surface of the dishes.

 Another method for washing dishes used in the world involves the direct application of the detergent compositions of the present invention, either undiluted or diluted in a dispensing bottle, onto contaminated dishes that must be cleaned. This can be accomplished by using a device for absorbing a liquid dishwashing detergent such as a sponge or rag, which is placed directly in a separate amount of undiluted or partially diluted liquid dishwashing composition for a period of time typically from about 1 to about 5 seconds. The absorption device and, therefore, undiluted or partially diluted liquid dishwashing composition can then be contacted separately with the surface of each item of contaminated dishes to remove food contaminants. The absorption device typically contacts the surface of each dish for about 1 to about 10 seconds, although the actual time of use depends on factors such as the degree of contamination of the dish. The contact of the absorption device with the surface of the dishes is preferably accompanied by parallel friction. This method may include immersing contaminated dishes in a bath of water without any liquid dishwashing detergent until contact and friction. After friction, dishes can be washed under running water.

 The following examples illustrate the invention and facilitate its understanding.

Example 1
An easy washing regimen is obtained for a liquid dishwashing detergent having the following composition:
Ingredient - Concentration, wt.%
C _12-13 alkylethoxy (1-3) sodium sulfate - 34
C _12-14 glucose amide - 4
Coconut Amino Oxide - 5
EO / PO block copolymer -Tetronic ^® 704 - 0.3
Ethanol - 7
Sodium xylene sulfonate - 5
Neodol ^® C ₁₁ E ₉ alcohol ethoxylate - 1
Flavoring agent - 0.2
Sodium Chloride - 4.0
Sodium Carbonate - 3.0
Water and minor impurities - Balance up to 100%
PH @ 10% (as done) - 10.1
Example 2
An easy washing regimen is obtained for a liquid dishwashing detergent composition with a particularly desirable stability at high and / or low temperature, having the following formulation:
Ingredient - Concentration, wt.%
C _12-13 alkylethoxy (1-3) sodium sulfate - 31
C _12-14 glucose amide - 4
Coconut Amino Oxide - 4
EO / PO block copolymer -Tetronic ^® 704 - 0.4
Ethanol - 5
Sodium xylene sulfonate - 5
Neodol ^® C ₁₁ E ₉ alcohol ethoxylate - 1
Flavoring agent - 0.2
Potassium chloride - 2.5
Potassium carbonate - 2.5
Water and minor impurities - Balance up to 100%
PH @ 10% (as done) - 10.5

Claims (4)

1. An aqueous pH-controlled, easy washing regimen liquid detergent composition having the necessary characteristics of foaming and removal of contaminants, containing, when used for cleaning heavily soiled dishes, an anionic surface-active component, a non-ionic surface-active component, a foam enhancer / stabilizer, aqueous liquid carrier and pH control agent, characterized in that it contains the following components, weight. %:
A) from 20 to 40% of the anionic surfactant component, which is characterized by alkyl ether sulfates containing from 8 to 18 carbon atoms in the alkyl group and from 1 to 6 moles of ethylene oxide per molecule;
B) from 3 to 10% of a nonionic surfactant component, which is characterized by surfactants selected from the group consisting of fatty amides of C _8-18 polyhydroxy acids and combinations of these amides of fatty polyhydroxy acids with from 0.2 to 2% of nonionic co a surfactant selected from the group consisting of ethoxylates of C _8-18 alcohols having from 1 to 15 moles of ethylene oxide, surfactants based on a block copolymer of ethylene oxide propylene oxide, and combinations of these nonionic co-surfactants;
C) from 2 to 6% of a foam enhancer / stabilizer selected from the group consisting of betaine surfactants, hydroxide free fatty acid amides, amine oxide semi-polar nonionic surfactants, C _8-22 alkyl polyglycosides and combinations of these foam enhancers / stabilizers;
D) from 45 to 75% of an aqueous liquid carrier;
E) from 0.2 to 6% pH of a control agent effective to maintain the pH of a 10% aqueous solution of the composition in the range from 9 to 11;
wherein said composition is substantially free of any source of magnesium or calcium ions. 2. The composition according to p. 1, which has the necessary stability at high and low temperatures, in which:
A) said anionic surfactant component is present in an amount of 31% or less by weight of the composition;
B) said aqueous liquid carrier comprises electrolytes in the form of a potassium salt; and
C) the specified pH control agent is potassium carbonate. 3. A pH-controlled aqueous, facilitating washing regimen liquid detergent composition having the necessary characteristics of foaming and removal of contaminants, containing, if heavily soiled dishes are used, alkyl ether sulfate containing from 10 to 16 carbon atoms in the alkyl group and from 1 to 3 moles of oxide ethylene per molecule, fatty amides -poligidroksikislot C _10-16, C _10-14 alcohol ethoxylate having from 8 to 12 moles of ethylene oxide, a polymeric surfactant characterized by ethylene oxide and etc. Pilėnai, condensed with ethylene diamine to form a block copolymer, an amine oxide nonionic surfactant, an aqueous carrier liquid and a pH controlling agent, characterized in that it comprises the following components, wt. %:
A) 25 to 35% of said alkyl ether sulfate;
B) from 3 to 5% of the indicated amides of polyhydroxy fatty acids;
C) from 0.5 to 1.5% of the indicated alcohol ethoxylates;
D) from 0.2 to 0.8% of the specified polymer surfactant having a molecular weight of from 4000 to 6000 and a hydrophilic-lipophilic balance of from 10 to 20;
E) from 3 to 6% coconut alkyldimethylamine oxide;
F) from 2 to 5% pH of a controlling agent of sodium carbonate or potassium carbonate, effective to maintain the pH of a 10% aqueous solution of the composition in the range from 10 to 11; and
G) from 50 to 65% aqueous liquid carrier containing hydrotropic substances selected from xylene and toluenesulfonates of alkali metals, and from 3 to 8% by weight of a solvent selected from C _1-4 alkanols;
wherein said composition is substantially free of any source of magnesium or calcium ions. 4. The composition according to p. 3, which has the necessary stability at high and low temperatures, in which:
A) said anionic surfactant component is present in an amount of 31% or less by weight of the composition;
B) said aqueous liquid carrier comprises electrolytes in the form of a potassium salt; and
C) the specified pH control agent is potassium carbonate. Priority on points:
05/16/1997 - on PP. 1 and 3;
06/30/1997 - on PP. 2 and 4.