CZ9904412A3 - Aqueous environment friendly detergent preparation - Google Patents

Abstract

Gentle means especially suitable for hand dishwashing, which contain a relatively high proportion of anionic surfactants light ethoxylated alkyl ether active ingredients sulfates, nonionic surfactants, substances promoting foam formation, which is preferably an amine oxide, and an aqueous carrier. Their the compositions exhibit the desired combination of high efficiency for fat removal, high foaming and particularly advantageous phase stability at low temperatures. They are also described thickened means.

Description

Aqueous, gentle liquid detergent

Technical field

The present invention relates to liquid dishwashing detergent compositions suitable for hand dishwashing. These compositions contain some detergent surfactants, suds suppressors, and other ingredients which, in combination, serve to achieve the desired low temperature stability as well as the customer's preferred grease removal and foaming properties of such a dishwashing detergent composition.

BACKGROUND OF THE INVENTION

Gentle liquid hand dishwashing detergent compositions are well known to those skilled in the art. These products are usually designed to provide a variety of strongly differentiated working and aesthetic properties. First and foremost, these dishwashing liquid or gel formulations must be prepared from such species and amounts of surfactants and other ingredients to provide acceptable solubility to remove food residues of particularly greasy impurities that are removed from the dishes or washed off their aqueous solutions. of dishes. In addition to being suitable for dishwashing, these gentle liquid detergent compositions also exhibit other properties that enhance the aesthetics or perception of the efficacy of manual dishwashing by the consumer. Thus, these useful liquid dishwashing compositions should also contain substances that promote the foaming properties of dishwashing solutions prepared from such articles. The foaming properties include both initially the easy formation of foam in a suitable amount in the wash water and the formation of foam that lasts for the duration of the dishwashing process.

• · · ·

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Finally, gentle consumer product formulations for dishwashing must have sufficient physical stability to withstand trading conditions, which may include exposure to extreme cold (including freezing temperatures) as well as long transport and storage periods. before such products are used.

It is not necessarily straightforward to determine the composition of the components of the green articles having all the necessary properties or the desired stability. Substances added to such products in order to positively affect a certain property may adversely affect another property of the product. In this situation, it is necessary to determine the composition of the liquid dishwashing composition which exhibits the desired balance between cleaning performance by aesthetic properties, such as foaming, and product stability. Accordingly, it is an object of the present invention to provide compositions of gentle liquid dishwashing compositions which are particularly effective in removing greasy food residues from dirty dishes when such compositions are used for hand dishwashing.

It is a further object of the present invention to provide such compositions which provide suitable and desired foaming properties.

It is a further object of the present invention to provide such compositions which exhibit particularly desirable low temperature stability.

It has been found that certain selected combinations of surfactants, suds enhancers of other ingredients may be formulated to provide compositions with the above-mentioned and desired properties.

• • •

SUMMARY OF THE INVENTION

The present invention relates to particularly stable aqueous gentle detergent compositions having particularly desirable grease removal and foaming efficiencies in the cleaning of soiled dishes. Such compositions comprise A) about 34 to 40% of a specific type of anionic surfactant component; B) about 0.3 to 4.5% of a specific type nonionic surfactant component; C) about 4.5 to 9% of a foam enhancer or foam stabilizer; and D) about 40 to 60% water as a liquid carrier.

The anionic surfactant component consists essentially of a slightly ethoxylated alkyl ether sulfate containing about 8 to 18 carbon atoms in the alkyl group. These slightly ethoxylated alkyl ether sulfates also contain about 0.4 to 1.6 moles of ethylene oxide per molecule.

The nonionic surfactant component may be selected from polyhydroxy fatty acid amides Cs-Cig, _C8 alcohol ethoxylate -cis having about 1 to 15 moles of ethylene oxide, the copolymer surfactant active substances based block co-polymer of ethylene oxide-propylene oxide and combinations nonionic copolymer surfactants. The suds boosters / foam stabilizers used in these compositions are selected with betaine surfactants, hydroxyl-free fatty acid amides, nonionic amine oxide semi-polar surfactants, _C8 -22 alkyl polyglycosides, and combinations thereof with suds boosters or stabilizers foam. In these compositions, the total concentration of component B, a nonionic surfactant, and component C, a suds suppressor or foam stabilizer, must be at least 7%.

Preferred compositions of the invention that exhibit particularly desirable low temperature stability are those which also contain a source (about 0.2 to 2%) of both Mg ⁺⁺ and Ca ⁺⁺ ions and at least 4% of a hydrotropic selected from the group of toluene. Alkali metal and calcium sulfonates. Furthermore, gentle liquid detergent compositions having a particularly desirable low temperature stability exhibit a pH of 7.5 or less at a concentration of 10%. Moreover, in such preferred compositions, if any, the ethoxylated alcohol nonionic surfactant content is not more than about 1%. The above essential ingredients as well as a number of optional additions can be combined by conventional means to form a gentle dishwashing composition according to the present invention.

SUMMARY OF THE INVENTION

The gentle liquid dishwashing detergent compositions of the present invention comprise four essential ingredients. They are:

(1) a certain type of anionic surfactant;

(2) a certain nonionic surfactant;

(3) certain suds boosters / foam stabilizers; and (4) an aqueous liquid carrier.

A wide variety of optional additions can also be used to achieve the desired efficacy, aesthetic effect, and optionally stability of such composition.

The essential and optional ingredients of a ready-to-use, gentle liquid or gel-like detergent dishwashing detergent composition are described in detail in the following, together with the preparation of the composition by its use. When describing the composition, it should be understood that the concept of gentle detergent compositions as used herein refers to those compositions which are used for hand washing. Such compositions are generally strongly foaming in nature. When describing the compositions of this invention, it should be understood that, unless otherwise stated, all concentrations and ratios are by weight.

• · · ·

Anionic surfactant component

The compositions described herein essentially comprise relatively large amounts, i.e., about 34 to 40%, of the anionic surfactant component

More preferably, this component represents 35% to 38% of the composition.

The anionic surfactant component is essentially a slightly ethoxylated alkyl ether sulfate. Alkyl ether sulfates are also known as alkyl polyethoxylated sulfates. These slightly ethoxylated alkyl sulfates correspond to the formula:

R '-O- (C ₂ H ₄ O) _n SO ₃ kde, where R' is C ₈ -C ₁₈ alkyl; n is about 0.4 to 1.6, and M is a salt-forming cation. It is preferred that R 'is alkyl Ci _i _{0 6} n is about 0.5 to 1.4, and M is sodium, potassium, ammonium, alkylammonium, or alkanolammonium. Most preferably R 'is C ₁₂ -C ₁₆ , n about 0.6 to 1.1 and M sodium. Alkyl ether sulfates will generally be used as mixtures containing a chain of variable length R 'and varying degrees of ethoxylation. Such mixtures will also necessarily contain some non-ethoxylated alkyl sulfates, i.e. surfactants of the above formula wherein n = 0.

Nonionic surfactants

The compositions herein also contain about 0.3% to 4.5% of a particular type of nonionic surfactant as an essential component. Preferably, the nonionic surfactant component will comprise about 0.4% to 4% of the final composition.

One type of nonionic surfactant that may be present in the nonionic surfactant component.

0 0 0

substance comprises C ₈ _i _8, preferably Cio-ie, polyhydroxy fatty acid amides. These substances are more specifically described in the Pan / Gosselink patent; US Patent 5,332,528; issued June 26, 1994, to which reference is made. These polyhydroxy fatty acid amides have the general structure represented by the formula:

AB ¹ ₂ II I

RCNZ wherein R ¹ is H, C 1 -C 4 hydrocarbyl, 2-hydroxyethyl,

2-hydroxypropyl, or a mixture thereof; R ² is C ₈ -C ₁₈ hydrocarbyl; and Z is a polyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least three 3 hydroxyls directly linked 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 C12-C16 glucamides can be used for lower foam formation. The polyhydroxy fatty acid amides will preferably represent about 1% to 5% of such a composition.

The component - nonionic surfactant - may also include ethoxylated alcohols. Ethoxylated alcohol surfactants useful in non-ionic surfactants are those whose general formula is as follows:

R 1 O- (C ₂ H ₄ O) _n SO ₃ M, wherein R ¹ is an alkyl group C ₈ -C ₁₈ and _n is in the range of about 1 to 15. Preferably R ¹ is a primary or secondary alkyl group containing from 1 to 15 carbon atoms. 11 to 14 carbon atoms, and more preferably 10 to 13 carbon atoms. Preferably, the ethoxylated fatty alcohols will contain from about 2 to 12 ethylene oxide units per molecule, and more preferably about 6 to 12 ethylene oxide units per molecule. Non-ionic co-acting

the ethoxylated fatty alcohol surfactant will have a portion having a hydrophilic-lipophilic balance (HLB) in the range of about 6 to 15, preferably about 10 to 15.

Examples of fatty alcohol ethoxylates useful as the co-acting nonionic surfactant used in the compositions herein are those prepared from alcohols having 12 to 15 carbon atoms and containing 7 moles of ethylene oxide. Such materials are commercially available under the trade names Neodol 25-7 and Neodol 23-6.5 from Shell Chemical Company. Other suitable Neodols include Neodol 1-5, an ethoxylated fatty alcohol having an average of 11 carbon atoms in its alkyl chain with about 5 moles of ethylene oxide; Neodol 23-9, an ethoxylated C12-C13 primary alcohol having about 9 moles of ethylene oxide and Neodol 91-10, an ethoxylated C8-Cn primary alcohol with about 10 moles of ethylene oxide. Alcohol ethoxylates of this type are marketed by Shell Chemical Company under the trade name Dobanol. Dobanol 91-5 is an ethoxylated C9-C11 fatty alcohol with an average of 5 moles of ethylene oxide and Dobanol 25-7 is an ethoxylated C12-C15 fatty alcohol with an average of 7 moles of ethylene oxide per mole of fatty alcohol.

Other examples of suitable ethoxylated alcoholic nonionic surfactants include Tergitol 15-S-7 and Tergitol 15S-9, both being secondary alcohol ethoxylates, which are commercial products of Union Carbide Corporation. The former is a mixed ethoxylated product of a linear secondary alcohol Cn to C15 with 7 moles of ethylene oxide, the latter is similar to the product but with 9 moles of ethylene oxide.

Other types of alcohol nonionic ethoxylates useful in the present compositions are higher molecular weight nonionics such as Neodol 45-11, which are similar ethylene oxide condensation products with higher fatty alcohols, and these higher fatty alcohols have 14-15 carbon atoms and the number of ethylene oxide groups is Such products are also offered by Shell Chemical Company.

Ethoxylated nonionic alcohols can help achieve the desired cleaning properties of the formulations. However, such substances may adversely affect the stability of the product at low temperatures. Thus, when used, the content of ethoxylated nonionic alcohols preferably will not be greater than about 1%, i.e. about 0.5 to 1% by weight of the composition.

Another type of nonionic surfactant suitable for use in these compositions as a nonionic surfactant component is a block of copolymers of ethylene oxide and propylene oxide, which act as polymeric surfactants. Such block copolymers contain one or more groups which are hydrophobic and are composed mostly of ethylene oxide moieties and one or more hydrophobic groups which are mainly composed of propylene oxide moieties in the molecule. Such groups are attached to the remainder of the compound containing one or more hydroxyl or amine groups. These polymeric surfactants have a molecular weight of 400 to 60,000.

Preferred ethylene oxide-propylene oxide polymeric surfactants are those in which the surface propylene oxide is condensed with an amine, especially a diamine, to form a base, which is then condensed with ethylene oxide. Substances of this type are sold under the trade name Tetronic®. Similar structures in which ethylenediamine is replaced by a polyol such as propylene glycol are sold under the trade name Pluronic®. Preferred ethylene oxide-propylene oxide (EO-PO) polymeric surfactants have an HLB (hydrophilic-lipophilic balance) which normally reaches about 4 to 30, preferably about 10 to 20.

The ethylene oxide-propylene oxide block copolymers used herein are described in detail in Pancheri / Mao; U.S. Pat. U.S. Patent 5,167,872;

This patent is incorporated herein by reference.

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The ethylene oxide-propylene oxide block copolymers will often be present in the compositions in an amount of 0.1% to 1%. Said compositions will contain 0.2% to 0.8%. of these polymeric surfactants.

Foam Promoters / Foam Stabilizers

Said compositions further comprise about 4.5% to 9%, preferably about 5% to 8%, of suds enhancers or foam stabilizers such as betaine-based surfactants, hydroxyl-free fatty acid amides, amine nonionic semipolar surfactants, and C ₈ _ ₂₂ alkyl polyglycosides. A combination of these suds boosters or foam stabilizers may also be used.

Betaine surfactants suitable as suds enhancers in the described applications generally have the following formula:

(-) (-)

R - N (R ^X ) ₂ - R ² COO wherein R is a hydrophobic group selected from alkyl groups containing 10 to 22 carbon atoms, preferably 12 to 18 carbon atoms, alkylaryl and arylalkyl groups similar to the number of carbon atoms with a benzene ring considered equivalent to about two carbon atoms and similar structures interrupted by amido and other bonds; each R ¹ is an alkyl group of one to three carbon atoms and R ² is an alkylene group of one to six carbon atoms.

Examples of preferred betaines are dodecyl dimethyl betaine, cetyl dimethyl betaine, dodecyl amidopropyldimethyl betaine, tetradecyldimethyl betaine, tetradecyl amidopropyl dimethyl betaine, and dodecyldimethylammonium hexanoate. Other suitable amidoalkylbetaines are disclosed in U.S. Pat. U.S. Patent No. 3,950,417; 4,137,191; and 4,375,421; and British Patent No. 2,103,236, all of which are incorporated by reference.

· <····

Amide hydroxyl-free surfactants useful as suds boosters in these applications are amides of ammonium, monoethanol, and diethanol fatty acids having an acyl moiety containing from about 8 to about 18 carbon atoms. Such materials are referred to herein as hydroxyl-free to distinguish them from polyhydroxy fatty acid amides principally used in the nonionic surfactant component as previously described herein. Accordingly, the hydroxyl-free amides for the purpose of this invention are those in which the acyl moiety does not contain hydroxyl substituents. These materials are represented by the formula:

R 1 - CO - N (H) _{m -} (R ₂ OH) ₃ - _m wherein R 1 is a saturated or unsaturated, hydroxy-free aliphatic hydrocarbon group of about 7 to 21, preferably about 11 to 17 carbon atoms; R ₂ represents a methylene or ethylene group; and m is 1, 2, or 3, preferably 1. Special examples of such amides are monoethanolamine amide and coconut fatty acid amide and diethanolamine amide and dodecylic acid amide amide. These acyl moieties can be prepared from natural glycerides, i.e., coconut oil, palm oil, soybean oil and tallow, but can also be prepared synthetically, e.g., by oxidation of petroleum intermediates or hydrogenation of carbon monoxide by Fischer-Tropsch synthesis. Preferably, C12-14 fatty acid monoethanolamides and diethanolamides are used.

Semi-polar nonionic surfactant amine oxides are useful as foam enhancers or as foam stabilizers, and these include compounds and mixtures of the following formulas:

r ₂

R _{1 -} (C ₂ H ₄₀ ) _n -N ------- O

R a wherein R 1 is alkyl, 2-hydroxyalkyl, 3-hydroxyalkyl, or

A 3-alkoxy-2-hydroxypropyl radical in which the alkyl or alkoxy group contains about 8 to about 18 carbon atoms, R ₂ and R ₂ are either methyl, ethyl, propyl, isopropyl, 2-hydroxypropyl, 2-hydroxypropyl, or 3-hydroxypropyl and n is 0 to about 10. Particularly preferred are amine oxides of the formula:

r ₂

AND

Ri — N ------ O,

R a wherein R 1 is C 12-16 alkyl and R ₂ and R ₃ are methyl or ethyl. The above hydroxy-free amides and amine oxides are more fully described in U.S. Patent 4,316,824, incorporated herein by reference.

Other surfactants suitable for use as suds enhancers / suds stabilizers in the compositions herein are nonionic fatty alkyl polyglycosides. Such substances have the following formula:

R ₂ O (C _n H 2 _n O) _y (Z) _x wherein Z is prepared from glucose, R is a hydrophobic substituent group selected from the group of substituents comprising: alkyl, alkylphenyl, hydroxyalkylphenyl, and mixtures thereof, wherein said alkyl group comprises 8 up to 22, preferably 12 to 14, carbon atoms;

• 9 n is 2 or 3, preferably 2, y is 0 to 10, preferably 0; and x is

1.5 to 8, preferably 1.5 to 4, most preferably 1.6 to 2.7. U.S. Patents 4,393,203 and 4,732,704, incorporated herein by reference, describe these alkyl polyglycoside surfactants.

The foam enhancing or stabilizing component described above must be present in the compositions herein in a certain relative amount to the nonionic surfactant component also described above. Thus, the total concentration of the nonionic surfactant component added to the foam enhancing or stabilizing component should be at least 7%, preferably at least 7% of the composition.

Aqueous liquid carrier

The gentle cleansing detergent compositions of the present invention further comprise about 40 to 60% of an aqueous liquid carrier in which the other essential and optional ingredients of the composition are dissolved, dispersed, or suspended. The compositions of the present invention preferably contain about 45-55% of an aqueous liquid carrier.

However, one essential component of the aqueous liquid carrier is water. However, the aqueous liquid carrier may contain other substances which are liquid or which dissolve in the aqueous liquid carrier at room temperature and which may serve purposes other than being a simple filler. Such materials may include, for example, hydrotropes and solvents.

(a) Hydrotropes

The aqueous liquid carrier may and preferably will contain one or more materials that are hydrotropic. Hydrotropes suitable for use in the compositions of this invention include C1-C3 alkyl aryl sulfonates, C ₆ -C ₂ alkanols, C! -C ₆ carboxylic sulfates and sulfonates, urea, _Ci-C6 hydrocarboxylates, • · · · · • * · Λ Λ Λ

C1 -C4 carboxylates, _{C2 -C4} organic diacids and mixtures of these hydrotrope materials.

Suitable C1-C3 alkylaryl sulfonates include xylene sulfonates; sodium toluene sulfonates and cumene sulfonates; substituted and unsubstituted sodium, potassium, calcium and ammonium sulfonates and mixtures thereof.

Suitable salts of C 1 -C ₈ carboxylic sulfates or sulfonates are all water-soluble salts or organic substances having 1 to 8 carbon atoms (excluding substituted groups), substituted with sulfate or sulfonate, and having at least one carboxyl group. The substituted organic substances may be cyclic, acyclic or aromatic, i.e. benzene derivatives. Preferred alkylated compounds have 1 to 4 carbon atoms substituted with sulfate or sulfonate and have 1 to 2 carboxyl groups. Examples of such hydrotropes include sulfosuccinate salts, sulfophthalic, sulfoacetic acid salts, m-sulfobenzoic acid salts, and sulfosuccinate diesters, preferably sodium and potassium salts, as shown in the US patent

3,915,903.

Suitable C1-C4 hydrocarbonates and carboxylates for use herein include acetates, propionates and citrates. Suitable _C2-C4 diacids for use herein are also within the group of succinic, glutaric and adipic acids.

Other substances which exhibit a hydrotropic effect and are suitable for use as hydrotropes are in the C ₆ -C ₁₂ alkanol and urea group.

Preferred hydrotropes for use herein are the sodium, potassium, calcium and ammonium sulfonates of xylene or toluene, and mixtures thereof. Most preferred are cumene sodium sulfonates, xylene calcium sulfonates and mixtures thereof. In the compositions, these preferred hydrotropes may comprise from about 3 to about 8 wt. %. In the compositions of the present invention, a concentration of 4 to 5% hydrotropes is particularly suitable to achieve the required low temperature stability.

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99

9 9 9 9

9

9

b) Solvents

A variety of water-miscible liquids such as lower alcohols, diols and other polyols, ethers, amines, and the like can be used as part of the aqueous liquid carrier. C 1-4 alkanols are particularly preferred. According to the invention, such solvents may be present in the compositions in concentrations of 3 to 8%.

Optional additives

Preferred optional ingredients of the compositions of the present invention include calcium and / or magnesium ion co-surfactants, enzymes such as protease, and enzyme stabilizing systems. These and other optional ingredients are described in the following:

(a) Auxiliary surfactants

The compositions of the present invention may contain a wide variety of surfactant adjuvants in addition to the essential surfactants described above. Such auxiliary surfactants, e.g. Cg- ₂ may include two alkyl sulfates; C9-15 alkylbenzene sulfonates; ₈ _ C ₂₂ olefin sulphonate · ty; C _8-2 2 alkyl sulfonates; C _8-22 alkyl glyceryl ether sulfonates; fatty acid ester sulfonates; secondary alcohol sulphates; C12-16 alkyl ethoxy carboxylates; Cn- ₁₆ secondary soaps; ampholytic detergent surfactants; and zwitterionic detergent surfactants.

(b) Calcium and magnesium ions

The presence of both calcium and magnesium ions can improve the cleaning performance of the fatty impurities of the various compositions of this invention, i.e. compositions containing alkyl ethoxy sulfates and / or polyhydroxy fatty acid amides. This is particularly true when the compositions are used in softened water that contains few divalent cations. It is known that you * »·» · »

0 »00 * 0 0 0

0 0 0

0 0 0 0 0 0 0 0

Penetrating and / or magnesium ions increase the coating of surfactant molecules on the oil / water interface, thereby reducing the interfacial tension and improving grease cleaning.

The addition of both calcium and magnesium ions may also improve the low temperature stability of the compositions of the present invention. Thus, this ion combination will preferably be present in the compositions of the invention at an active level of 0.2 to 2%, and more preferably 0.3 to 1.5 wt. %.

Magnesium ions such as hydroxide or chloride, sulfate, acetate, formate, oxide, or nitrate are preferably added to the compositions of the present invention. Inorganic salts such as chlorides and sulfates are preferred and can provide stability at particularly low temperatures. Such magnesium salts may be present in the compositions of the present invention at concentrations of 2 to 6%. Magnesium ions may also be added as a cation to the anionic surfactant used. It is preferred to add calcium ions to the compositions of the present invention as salts of the hydrotrope.

The amount of calcium or magnesium ions present in the compositions of the present invention will depend on the total amount of surfactant in the composition. When calcium and magnesium ions are present in the compositions of the invention, the molar ratio of calcium and magnesium ions to the total amount of anionic surfactants should be about 0.25: 1 to 2: 1.

There are difficulties in finding a formulation for those compositions containing divalent ions in alkaline pH matrices due to the incompatibility of divalent ions, especially magnesium ions with hydroxyl ions. When both divalent ions and alkaline media are used in combination with the surfactant mixture of the present invention, better grease cleaning performance is achieved than would be in the alkaline region or using one of the divalent ions separately. However, the formation of hydroxide precipitates upon storage points to a lack of storage. The brave stability of the composition of the present invention. Therefore, the use of complexing agents may be unavoidable in the discussion discussed below.

c) Protease and / or other enzymes

The compositions of the invention may also optionally contain 0.001 to 5, preferably about 0.003 to about 4, and most preferably 0.005 to 3 wt. % active protease, i.e. proteolytic enzyme. Protease activity can be expressed in units according to Anson (AU) per kg of detergent composition. Values of 0.01 to 150, preferably 0.05 to 80 and most preferably 0.1 to 40 AU per kg are acceptable for the compositions of the invention.

Suitable proteolytic enzymes may be of animal, plant or microbial origin (preferably). A serine proteolytic enzyme of bacterial origin is preferred. Both purified and non-purified forms of this enzyme can be used. Proteolytic enzymes produced by chemically or genetically modified mutants are by definition included because they are close structural variants. Particularly preferred are bacterial serine proteolytic enzymes obtained from Bacillus subtilis and / or Bacillus licheniformis.

Suitable proteolytic enzymes include Novo Industri A / S Alcalase® (preferably), Esperase®, Savinase® (Copenhagen, Denmark), Gist-brocades' Maxatase®, Maxacal® and Maxap 15® (protein engineered Maxacal®) (Delfty, Netherlands), and subtilisin BPN and BPN '(preferably), which can be ordered. Preferred proteolytic enzymes are also modified serine proteases produced by Genencor International, Inc. (San Francisco, California, USA), which are described in European Patent EP-B251,446, issued Dec. 28, 1994 and published Jan. 7, 1988 (especially pages 17, 24, and 98), and referred to herein as Protease. BUS No. 5,030,378, Venegas, issued July 9, 1991, referring to a modified bacterial serine proteolytic enzyme (Genencor International)

Which is called Protease A in this description (the same as BPN '). Particular attention should be paid to U.S. Pat. No. 5,030,378 for a complete description including the amino acid sequence of Protease A and variants thereof. Preferred proteolytic enzymes are then selected from the group consisting of Alcalase ® (Novo Industri A / S), BPN ', Protease A and Protease B (Genencor), and mixtures thereof. Most preferred is Protease B.

Another preferred protease, referred to herein as Protease D, is a variant of a carbonyl hydrolase having an amino acid sequence not found in nature, which is derived from a carbonyl hydrolase precursor by substituting another amino acid for a number of amino acid residues at the carbonyl hydrolase site equivalent to +76 , preferably also in combination with one or more amino acid residues at sites equivalent to those selected from the groups 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 according to the numbering of Bacillus amyloliquefaciens subtilisin as described in WO 95/10615 published April 20, 1995 by Genencor International.

Suitable proteases are also described in PCT publications: WO 95/30010 of November 9, 1995 by The Procter & Gamble Company; WO 95/30011 of November 9, 1995 to The Procter & Gamble Company; WO 95/29979 of November 9, 1995 to The Procter & Gamble Company.

Other optional enzymes such as lipase / or amylase may also be added to the composition of the invention to further improve the cleaning properties.

(d) Enzyme stabilization system

The compositions of the invention may preferably contain about 0.001 to about 10%, more preferably 0.005 to about 8%, most preferably about 0.01 to about 6% by weight. % of the enzyme stabilization system. The enzyme stabilization system may be any stabilization system that is compatible with protease or other enzymes φ ·

used in the compositions of the present invention. Such stabilization systems may include calcium ions, boric acid, propylene glycol, short carboxylic acids, polyhydroxyl compounds, and mixtures thereof, as described in U.S. Pat. No. 4,261,868, Mountain and Others, issued Apr. 14, 1981; No. 4,404,115, Tai, Sep. 13, 1983; 4,318,818, Letton and others; No. 4,243,543, Guildert et al., Issued Jan. 6, 1981; 4,462,922, Boskamp, Jul. 31, 1984; 4,532,064, Boskamp, issued July 30, 1988; and 4,537,707, Severson Jr., issued Aug. 27, 1985, all of which are incorporated herein by reference.

In addition, 0 to 10, preferably 0.01 to about 6 wt. % scavanger reducing agents for deactivating the chlorine or oxygen bleach to prevent, in particular in an alkaline environment, the chlorine present in a number of drinking water sources from attacking and deactivating the enzymes. Although typical concentrations of chlorine in water may be very low from 0.5 to about 1.75 ppm, the amount of available chlorine in the entire volume of water that comes into contact with enzymes when washing dishes is usually large and accordingly the stability of the enzymes when applied may be a problem.

Suitable anionic inactivating agents for active chlorine are salts containing ammonium cations. These can be selected from the group consisting of reducing agents such as sulfites, bisulfites, thiosulfites, thiosulfates, iodides and the like. Antioxidants such as carbonates, ascorbates, and the like. organic amines such as ethylenediaminetetraacetic acid (EDTA) or its alkali metal salt and monoethanolamine (MEA), and mixtures thereof. Other conventional anions and anion mixtures having inactivating activity for active chlorine may also be used, such as sulfates, bisulfates, carbonates, bicarbonates, percarbonates, nitrates, chlorides, borates, sodium perborate tetrahydrate, sodium perborate monohydrate, percarbonates, polyphosphate phosphates, acetates, benzoates, citrates, formates, salts of lactic, maleic, tartaric, salicylic, etc.

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4 4 4 · · · · · · · ·

e) Various optional ingredients

Other conventional optional ingredients that are commonly used as additives with less than 5% include opacifiers, antioxidants, bactericides, dyes, thickeners (e.g.

, hydroxypropyl methylcellulose), perfumes, and the like. In addition, detergent builders may also be present in the compositions of the present invention at concentrations of 0 to 50%, preferably 2 to 30%, most preferably 5 to 15%. The gentle compositions of hand dishwashing compositions are typically free of detergent builders. However, some formulations containing calcium or magnesium ions may need the additional presence of low concentrations of preferably 0 to about 10, preferably about 0.5 to about 3%, complexing agents selected preferably from the group consisting of bicine / bis (2-ethanol) blycine), citrate N - (2-hydroxylethyl) iminodiacetic acid (HIDA), N- (2,3-dihydroxypropyl) diethanolamine, 1,2-diamino-2-propanol N, N'-tetramethyl-1,3-diamino-2-propanol, Ν , Ν-bis (2-hydroxyethyl) glycine (aka bicine), and Ntris (hydroxymethyl) methyl glycine (aka tricine). All mixtures thereof are also acceptable.

Concentrated products

The liquid dishwashing detergent compositions of the present invention, which are relatively dense in the sense of having a high viscosity, can be prepared without the use of polymeric thickeners by selecting the specific type and amount of ingredients described above. In this case, relatively dense products may be prepared such that:

1) the nonionic surfactant-containing component is substantially free, i.e., contains no more than 1 wt. % of polyhydroxy fatty acid amines; 2) the calcium ion concentration in the composition is 0.35% or less. * * * * * * * *

3) the concentration of magnesium ions in the composition is 0.75% or less;

4) the concentration of C _1-4 alkanols in the aqueous liquid carrier is not more than 3%; and

5) about 4 to 8% of hydrotropes selected from xylene and toluene sulfonates are used.

The liquid detergent compositions of the present invention that are thickened will have a Brookfield viscosity of 0.5 to 2.5

3.5 Pa.s at 25 ° C. It is preferred that such thickened products have a viscosity of 0.8 to 2.0 Pa.s at 25 ° C. For the purposes of the present invention, the viscosity is measured on a Brookfield LVTDV-11 viscometer with an RV # 2 rotor at 1.0 rpm.

pH of the composition

The dishwashing detergent composition of the present invention generally has a pH of 6-8 for its 10% aqueous solutions. It is preferable that it has a natural alkaline reaction of about pH 7 to 7.8 for 10% aqueous solutions. The composition having the desired low temperature stability is formulated such that the pH of its 10% aqueous solution is less than 7.5.

Dishwashing compositions will be exposed to the acidic stress created by food debris when used, i.e., diluted and used to remove dirt from the dishes. If a composition with a pH greater than 7 is more effective, it should contain a buffering agent capable of maintaining a higher pH in dilute solutions, i.e. about 0.1 to 0.4% aqueous solution of the composition. The pK of such a buffer should be about 0.5 to 1.0 pH units below the desired pH of the composition (determined as described above)

The preferred pH of the buffer should be about 7 to 9.5. Under such conditions, the buffer most effectively attenuates the pH and thus can be used in a minimal amount.

The buffering agent may be an active detergent per se, or it may be a low molecular weight organic or inorganic detergent.

4 4 4 4 4

I 4,444 4,444 «44 4

W 44 · · 44 4 4 44 · • 4 4 4 4 4 · 4 44 44 substance that is used only to maintain pH in the alkaline range. Nitrogen-containing buffering agents are preferably used for the compositions of the present invention. Some examples are amino acids, lower alkolamines such as mono-, di-, and triethanolamine. Useful inorganic buffers / sources of basicity include alkali metal carbonates such as sodium carbonate.

The buffering agent, when present in the compositions of the present invention, is present in concentrations of about 0.1 to 15, preferably about 1 to 10, most preferably about 2 to 8% of the composition.

Preparation of the composition

The liquid or gelled detergent composition of the invention may be formulated by combining essential and optional ingredients in any suitable manner using appropriate mixing to produce a homogeneous product. For the preparation of the detergent compositions of the present invention and for the preparation of the various components of such compositions, the methods described in detail in Ofos Asante patent; U.S. Pat. 5,474,710; of 12 December 1995, which is incorporated herein by reference.

Stability of the composition

The liquid dishwashing detergent compositions of the present invention exhibit the desired phase stability even when subjected to prolonged low temperature and solidification / melting phase transition testing. For example, when the products are exposed to a temperature of 4.4 ° C and examined for phase instability such as haze, the compositions of the invention are generally stable for no less than 4 days. If such products are subjected to freezing conditions of -18 ° C for 16 hours and then heated; the temperature at which the solidification phase instability should disappear should be 16 ° C or less.

- 22 ··· · · I I * * e e e e e e e

Method of washing dishes

Dirty dishes should be contacted with a sufficient amount of usually about 0.5 to 20 ml (per 25 dishwashed), preferably about 3 to about 10 ml of the detergent composition of the invention. The actual amount of liquid detergent composition will depend on the judgment of the user and will generally depend on such factors as the specific determination of the composition of the individual components of the composition, including the concentration of active ingredients in the composition, the amount of dirty dishes being washed, the degree of soiling. The formulation for a particular device will in turn depend on a number of factors, such as the intended market (ie, the US, Europe, Japan, etc.) for that particular device.

The following are examples of typical methods in which the detergent compositions of the present invention can be used for dishwashing. These examples are illustrative and are not intended to limit the disclosure in any way.

In a typical use for the US about 3 to about 15, preferably about up to about 10 ml. The liquid detergent composition is mixed with about 1,000 to about 10,000, typically about 3,000 to 5,000 ml of water in a nozzle having a capacity of about 5,000 to 20,000. Typical is about 10,000 to 15,000 ml. The surfactant in the detergent composition has a concentration of about 21 to about 44, preferably about 25 to 40%. Dirty dishes are immersed in a sink containing detergent and water, where they are washed by contacting the soiled surface of the dishes with a cloth, sponge or the like. This cloth sponge or the like can be soaked in the detergent / water mixture before they come into contact with the cookware surface for a typical period of from 1 to 10 seconds, although the actual contact time will vary for each use and user. The contact of the cloth with a sponge or similar object is accompanied by the simultaneous scrubbing of the surface of the dishes.

In a typical application for the European market, about 3 to about 15, preferably about 3 to about 10 ml of a liquid detergent composition is dissolved in about 1,000 to about 10,000, typically about 3,000 to about 10,000. ♦ ·

In a nozzle having a volume capacity of about 5,000 to about 20,000 ml, a typical capacity is about 10,000 to about 15,000 ml. The surfactant in the detergent composition has a concentration of about 20 to about 50%, preferably about 30 to 40%. Dirty dishes are immersed in a sink containing detergent and water, where they are washed by contacting the soiled surface of the dishes with a cloth, sponge or the like. This cloth sponge or the like can be soaked in a detergent / water mixture before they come into contact with the cookware surface and are typically in contact with the dishes for 1 to 10 seconds, although the actual contact time will vary for individual uses and users. The contact of the cloth with a sponge or similar object is accompanied by the simultaneous scrubbing of the surface of the dishes.

In a typical Latin American market, about 1 to 50, preferably about 2 to about 10 ml of a liquid detergent composition is dissolved in about 50 to about 2,000, typically about 100 to 1,000 ml of water in a bowl having a volume capacity of about 500 to about 5,000, typically about 500 to about 2000 ml capacity. The surfactant in the detergent composition has a concentration of about 5 to about 40, preferably about 10 to 30%. Dirty dishes are immersed in a sink containing detergent and water where they are washed by contacting the soiled surface of the dishes with a cloth, sponge or the like. This cloth sponge or the like can be soaked in a detergent / water mixture before they come into contact with the cookware surface and are typically in contact with the dishes for 1 to 10 seconds, although the actual contact time will vary for individual uses and users. The contact of the cloth with a sponge or similar object is accompanied by the simultaneous scrubbing of the surface of the dishes.

Another method of dishwashing used worldwide, i.e., the direct application of the detergent composition of the invention to washed soiled dishes, either as it is or diluted in a dispenser vial. This can be achieved by using a device for absorbing a liquid dishwashing liquid such as a sponge or a snake. 9 9 9 1 V · ft Rinse dishes which are placed for a period of about 1 to 5 seconds directly in a separate amount of undiluted or slightly diluted. The absorbent utensil and the subsequently undiluted or somewhat dilute liquid dishwashing composition may then individually come into contact with the surface of each individual piece of soiled dishware to remove food contaminants. The absorbing device is in contact with each surface of the dishes for about 1 to 10 seconds, although the actual time will depend on such factors as the degree of soiling of the dishes. It is preferred that the contact of the absorbing device with the surface of the dishes is accompanied by simultaneous scrubbing. Prior to contact and scrubbing, the method may include immersing dirty dishes in a water bath without any liquid dishwashing detergents. After scrubbing, the dishes can be rinsed under running water.

The following examples illustrate the invention and facilitate understanding.

φ φ · · · · · · φ φ φ φ φ φ φ φ φ φ φ φ φ φ φ φ

DETAILED DESCRIPTION OF THE INVENTION

Examples I-IV

Gentle liquid dishwashing detergent compositions having the following compositions have been prepared.

Concentration (% by weight)

Ingredient AND II III IV C12-13 alkyl ethoxy (1,4) sodium sulfate 36 C12-13 alkyl ethoxy (1,0) sodium sulfate 36 34.4 C12-13 alkyl ethoxy (0,6) sodium sulfate 34 C12-14 glucose amide 1.5 1.5 1.5 coconut oil amide oxide 5.2 5.2 4.9 8.0 EO / PO block copolymer - Tetronic® 704 0.4 0.4 0.4 0.4 Neodol® C11E9 alcohol ethoxylate 1.0 1.0 1.0 Ethanol 5.3 5.3 5.6 6.5 Calcium xylene sulfonate 3.0 3.2 3.6 sodium xylene sulfonate 1,2 1,2 1.4 5.4 magnesium chloride 2.8 2.8 2.8 2.4 Water and small things --- Addition to 100% - - pH (10% solution) 7.4 7.4 7.4 7.7

All of these liquid dishwashing detergent compositions excellently remove greasy dirt from the dishes and have excellent foaming properties when used in aqueous dishwashing solutions for dishwashing. These products also have a particularly desirable low temperature stability as evidenced, for example, by their behavior at a constant temperature of 4.4 ° C and the restoration of the original properties ie removal of turbidity during solidification and melting testing at -18 ° C.

Example V

A thickened, gentle liquid dishwashing detergent composition having a relatively high viscosity was prepared according to the following recipe. It is a product free of polyhydroxy fatty acid amides and polymeric thickeners.

Ingredient • ΦΦ φφφ φφφφ • a · · · and φ ·· · · ·

Concentration (% by weight)

C12-13 alkyl ethoxy (1.0) sodium sulphate amide coconut oil oxide

EO / PO block copolymer - Tetronic® 704

Neodol® C11E9 alcohol ethoxylate

Ethyl xylene calcium sulphonate sodium xylene sulphonate magnesium chloride

Water and small products ---- pH (10% solution)

0.4

1.0

1.5

1.6 4.1 0.3

100% - 7.5

Viscosity (Pa.s)

1,020

Claims (6)

PATENT CLAIMS An aqueous, gentle liquid detergent composition having a particularly desirable low temperature stability and also having a particularly desirable ability to remove greasy impurities, and having foaming properties for use in a dishwashing composition comprising: A) 34 to 40 wt. % of an anionic surfactant component which is characterized by a slightly ethoxylated alkyl ether sulfate containing about 8 to 18 carbon atoms in the alkyl group and 0.4 to 1.6 moles of ethylene oxide per mole of the substance; B) 0.3 to 4.5 wt. % Of the component comprising a nonionic surfactant, which is characterized in that the surfactant is selected from the group consisting of amides of C ₈ -i8 polyhydroxy fatty acid ethoxylates, C ₈ -i8 alcohols having from 1 to 15 moles of ethylene oxide per surfactant ethylene oxide-propylene oxide block copolymer bases and combinations of said nonionic surfactants C) 4.5 to 9 wt. % Suds boosters / foam stabilizer selected from the group consisting of betaine surfactants, amide, hydroxyl-free fatty acids, amine oxide semipolar nonionic surfactants, _C8 _22 alkylpolyglycosides and combinations of said suds boosters / stabilizers; provided that in said composition the total concentration of such suds / stabilizers component C and said surfactant component B is at least 7 wt. %. and D) 40 to 60 wt. % of an aqueous liquid carrier. • · • * . 9 4 4 9 4 9 4 4 4 4 4 9 4 Β Β · · 2. An aqueous, gentle liquid detergent composition having a particularly desirable low temperature stability, and also having a particularly desirable ability to remove greasy soils, also has foaming properties when used in a dishwashing composition, comprising: A) 35 to 38 wt. % of an anionic surfactant component characterized by a slightly ethoxylated alkyl ether sulfate having from 11 to 14 carbon atoms in the alkyl group of 0.5 to 1.4 moles of ethylene oxide per mole of the substance B) from 0.4% to 4.0 wt.% Of component a nonionic surfactant characterized in that the surfactant is selected from the group consisting of amides Cn_i ₄ hydroxy fatty acids, and _4-Cn alcohol ethoxylates with 6-12 moles of ethylene oxide , ethylene oxide-propylene oxide based surfactants block copolymers and combinations of said nonionic surfactants; C) 5.0 to 9 wt. % foam builders / foam stabilizers selected from the group consisting of betaine surfactant, hydroxy-free fatty acid amide, semipolar nonionic surfactant amine oxide, C 8-22 alkylpolyglycosides, and combinations of said foam builders / stabilizers; provided that, in said composition, the total concentration of such suds / stabilizers component C and the above surfactant component B is at least 9 wt. % D) 0.2 to 2 wt. % combination of both Mg ⁺⁺ and Ca ⁺⁺ ions and E) 40 to 60 wt. % of an aqueous liquid carrier. Composition according to claims 1 to 6, characterized in that it has a pH of 10% aqueous solution of 7.5 or less. 9 · - 29 / rw 'flfl flfl flflfl flflflfl flflfl fl flflfl flfl flfl fl flfl fl Composition according to claims 1 to 7, characterized in that it comprises at least 5% of a hydrotrope selected from alkali metal salts of calcium sulfonates of xylene and toluene. Composition according to claims 1 to 8, characterized in that it contains up to 1 wt. % nonionic surfactant based on ethoxylated alcohol. 6. A composition according to claims 1-9 ¹ wherein said magnesium source is magnesium chloride or magnesium sulfate.