CA2308920A1

CA2308920A1 - Acidic aqueous multiphase cleaner

Info

Publication number: CA2308920A1
Application number: CA 2308920
Authority: CA
Inventors: Georg Meine; Ryszard Katowicz
Original assignee: Henkel AG and Co KGaA
Current assignee: Individual
Priority date: 1999-05-19
Filing date: 2000-05-19
Publication date: 2000-11-19
Also published as: DE19922824A1; CO5211007A1; WO2000071665A1; AR024028A1; AU4756300A

Abstract

An aqueous liquid multiphase surfactant-containing cleaner having at least two continuous phases, which has at least one lower aqueous phase I
and an upper aqueous phase II which is immiscible with the first phase and which can be temporarily converted into an emulsion by shaking, which comprises at least one acid and, in the form of the temporary emulsion, has a pH of less than 7, can be used for the cleaning of hard surfaces and can be prepared by blending directly from its raw materials, subsequently mixing thoroughly and finally allowing the composition to stand for separation of the temporary emulsion.

Description

"Acidic aqueous multiphase cleaner"
Field of the Invention The invention relates to acidic aqueous multiphase liquid surfactant-containing cleaners which can be emulsified temporarily by shaking and can be used for the cleaning of hard surfaces, to a process for their preparation and to the use thereof for the cleaning of hard surfaces.
Background of the Invention Cleaners which can be used universally for all hard, wet or damp wipable surfaces for domestic and commercial use are known as so-called all-purpose cleaners and are largely neutral to slightly alkaline aqueous liquid products which comprise from 1 to 30o by weight of surfactants, from 0 to 5% by weight of builders (e. g. citrates, gluconates, soda, polycarboxylates), from 0 to 10% by weight of hydrotropic agents (e.g. alcohols, urea), from 0 to 10%
by weight of water-soluble solvents (e. g. alcohols, glycol ethers), and, if desired, inter alia skin protectants, dyes and fragrances. For use in the sanitary field as so-called bath cleaners, by contrast, such cleaners are often rendered acidic by the addition of acids in order to be able to better remove lime and water spots. They are mostly used as about to strength solutions in water, but also neat for local stain removal. Ready-to-use all-purpose cleaners are also available commercially as so-called spray cleaners.
Aqueous liquid cleaners of this type are usually in the form of homogeneous stable solutions or dispersions. The use of certain, in particular hydrophobic, components in such cleaners can, however, lead to this homogeneity being lost and inhomogeneous compositions being obtained, the acceptance of which by the consumer is assessed as low. In such cases there is a need for alternative formulation of compositions ' - 2 _ which, despite their inhomogeneity; have a defined external appearance and use form which is acceptable to the consumer.
European Patent Application 116 422 describes a liquid hair or body shampoo having two aqueous phases which can be dispersed temporarily in one another by shaking and where both phases are miscible with water in any ratio. Here, the upper phase comprises from 8 to 25% by weight, based on the overall composition, of at least one surfactant, and the lower phase' at least 6%
by weight, based on the overall composition, of dissolved sodium hexametaphosphate of the formula I, ONa ONa OWa NaQ--I I P-ODia <<) O ~ o cp-Zi in which n is an average value of about 12. Optionally, further builder salts may be present in the lower phase. Surfactants which may be present are anionic, cationic, amphoteric and/or nonionic surfactants, at least one anionic surfactant preferably being present.
German Laid-Open specifications 195 Ol 184, '187 and '188 (Henkel KGaA) disclose hair-treatment compositions in the form of a two-phase system which has one oil phase and one water phase, the oil phase being based on silicone oil or paraffin oil, an3 are temporarily miscible by mechanical action.
The object of the present invention was to provide high-performance and storage-stable compositions for the cleaning of hard surfaces, in particular in the sanitary field, in a defined inhomogeneous form which is easy to handle and acceptable to the consumer.
Description of the Invention The invention provides an aqueous liquid mu~a_.phase surfactant-containing cleaner having at least two continuous phases, which has at least one lower aqueous phase I and an upper aqueous phase II

which is immiscible with the first phase and which can be temporarily converted into an emulsion by shaking, and which comprises at least one acid and, in the form of the temporary emulsion, has a pH of less than 7.
The invention likewise provides for the use of a composition according to the invention for the cleaning of hard surfaces.
For the purposes of the present invention, temporary means that 90% of the cracking of the emulsion formed by shaking into the separate phases at temperatures of from about 20°C to about 40°C takes place over the course of 2 minutes to 10 hours, and the last 2% of the cracking into the phase state prior to shaking takes place over the course of a further 15 minutes to 50 hours.
Furthermore, for the purposes of the present invention - unless expressly stated otherwise, the use of a salt is just as possible as the use of the corresponding acid/base pair of the salt which produces the salt or its solution only in situ with neutralization, even if the respective alternative is not always explicitly formulated in the present teaching. In this respect, potassium citrate and the combination of citric acid/potassium hydroxide or potassium alkylbenzenesulfonate and the combination alkylbenzenesulfonic acid/potassium hydroxide are equal alternatives.
Finally, for the purposes of the present invention, if it is possible for a particular component to be used for different purposes, then its use may be described more than once below, knowingly or unknowingly. This is true, for example, for citric acid, which is used both as an acid to adjust the pH
and as a phase-separation auxiliary and builder, and also for anion-active sulfonic acids, which act both as acids and as anionic surfactants.
The compositions according to the invention are notable for high cleaning performance when applied neat or in dilute form - both in the bathroom and the kitchen. Moreover the compositions exhibit a favorable residue behavior. The individual phases in the composition are stable over a long period without, for example, the formation of deposits, and conversion to a temporary emulsion remains reversible even after frequent shaking. Furthermore, the compositions permit the stable incorporation of components which can be stably incorporated into single-phase aqueous solutions or stable emulsions or microemulsions only through the use of solvents, solubilizers and emulsifiers. In addition, separation of ingredients into separate phases can promote the chemical stability of the composition.
The pH of the compositions according to the invention is usually 1 to 6.5, preferably 2 to 6, in particular 2.5 to 5.5, particularly preferably 3 to 5, most preferably 3.5 to 4.5.
To set the pH according to the invention, the compositions comprise at least one acid. Suitable acids are inorganic acids, for example the mineral acids, e.g. hydrochloric acid, and organic acids, for example saturated or unsaturated C1_6-mono-, -di- and -tricarboxylic acids and -hydroxycarboxylic acids having one or more hydroxyl groups, e.g. citric acid, malefic acid, formic acid and acetic acid, amidosulfuric acid, C6_22-fatty acids and anion-active sulfonic acids, and mixtures thereof, e.g. the succinic acid/glutaric acid/adipic acid mixture obtainable under the tradename Sokalan~ DCS from BASF.
If necessary, it is additionally possible to use one or more alkalis, for example the alkali metal, alkaline earth metal and ammonium hydroxides and carbonates, and ammonia, preferably sodium and potassium hydroxide, particular preference being given to potassium hydroxide.
Anion-active sulfonic acids for the purposes of the teaching according to the invention are sulfonic acids of the formula R-S03H which carry a partially or completely straight-chain and/or branched and/or cyclic, and partially or completely saturated and/or unsaturated and/or aromatic C6_32-hYdrocarbon radical R, for example C6_22-alkanesulfonic acids, C6_22-a-olefinsulfonic acids and Cl_22-alkyl-C6_lo-arenesulfonic acids, such as Cl_22-alkylbenzenesulfonic acids or Cl_22-alkylnaphthalenesulfonic acids, preferably linear Ca_ls-alkylbenzenesulfonic acids, in particular linear Clo_14-alkyl-, Clo-13-alkyl- and C12-alkylbenzenesulfonic acids .
Particularly preferred acids are citric acid, preferably used in the form of its monohydrate citric acid 1H20, and the anion-active sulfonic acids, and combinations of citric acid with one or more anion-active sulfonic acids, in particular with alkylarene-sulfonic acids. The citric acid combines in an advantageous manner acid, builder and phase-separation auxiliary properties, while the anion-active sulfonic acids act as an acid and anionic surfactant at the same time.
The composition according to the invention comprises one or more acids in an amount by weight which suffices for setting the desired acidic pH and which can be chosen according to the strength and molar mass of the respective acids, and which is usually between 0.1 and 30% by weight, in particular between 1 and 20o by weight. In some instances it may be advantageous, particularly when the acid, as described above and also below, also satisfies other functions at the same time, to use more acid than is required to set the pH. In this case, compositions according to the invention additionally comprise one or more alkalis.
Phases In the simplest case, a composition according to the invention consists of a lower continuous phase, which consists of the whole of phase I, and of an upper continuous phase, which consists of the whole of phase II. One or more continuous phases of a composition according to the invention can, however, also comprise parts of another phase in emulsified form, meaning that in such a composition, for example, some of phase I is in the form of continuous phase I, which is the lower continuous phase of the composition, and some is emulsified as discontinuous phase I in the upper continuous phase II. The same applies for phase II and other continuous phases.
In a preferred embodiment of the invention, the continuous phases I and II are delimited from one another by a sharp interface.
In a further preferred embodiment of the invention, one or both of the continuous phases I and II comprise parts, preferably from 0.1 to 25% by volume, in particular from 0.2 to 15o by volume, based on the volume of the respective continuous phase, of the other phase in each case as dispersant. Here, the continuous phase I or II is then reduced by the volume part, which is distributed as dispersant in the other phase in each case. Particular preference is given in this connection to compositions in which phase I is emulsified in phase II in amounts of from 0.1 to 25o by volume, preferably from 0.2 to 15o by volume, based on the volume of phase II.
In a further preferred embodiment of the invention, in addition to the continuous phases I and II, part of the two phases is in the form of an emulsion of one of the two phases in the other phase, this emulsion being delimited by two sharp interfaces, one upper and one lower, from the parts of phases I and II not involved in the emulsion.
The compositions according to the invention comprise phase I and phase II in a volume ratio of from 90:10 to 10:90, preferably from 75:25 to 25:75, in particular from 65:35 to 35:65.
Hydrophobic components In a particularly advantageous embodiment of the invention, the compositions comprise one or more hydrophobic components. The hydrophobic components improve not only the cleaning action on hydrophobic contaminants such as grease soiling, but additionally _ 7 _ have a positive action on the phase separation and the reversibility thereof. Suitable hydrophobic components are, for example, dialkyl ethers having identical or different C4- to C14-alkyl radicals, in particular linear dioctyl ether; hydrocarbons having a boiling range from 100 to 300°C, in particular from 140 to 280°C, e.g. aliphatic hydrocarbons having a boiling range from 145 to 200°C, isoparaffins having a boiling range from 200 to 260°C; essential oils, in particular limonene and the pine oil extracted from pine roots and stumps; and also mixtures of these hydrophobic components, in particular mixtures of two or three of said hydrophobic components. Preferred mixtures of hydrophobic components are mixtures of different dialkyl ethers, of dialkyl ethers and hydrocarbons, of dialkyl ethers and essential oils, of hydrocarbons and essential oils, of dialkyl ethers and hydrocarbons and essential oils and of these mixtures. The compositions comprise hydrophobic components in amounts, based on the composition, of from 0 to 20o by weight, preferably from 0.1 to 14o by weight, in particular from 0.5 to 10% by weight, most preferably from 0.8 to 7% by weight.
Phase-separation auxiliaries The compositions according to the invention can comprise phase-separation auxiliaries. Suitable phase-separation auxiliaries are, in addition to citric acid and citrates, for example the alkali metal and alkaline earth metal halides, in particular chlorides, and sulfates and nitrates, in particular sodium and potassium chloride and sulfate, and ammonium chloride and sulfate, and mixtures thereof. Being strong electrolytes, and increasing the ionic strength, said salts aid phase separation as a result of the salt effect. In this connection, sodium chloride has proven particularly effective, while sodium sulfate and in particular magnesium sulfate have a lower phase separation action. The compositions comprise phase-separation auxiliaries in amounts, based on the - _ 8 -composition, of from 0 to 30% by weight, preferably 1 to 20o by weight, in particular 3 to 15o by weight, most preferably from 5 to 12% by weight.
Surfactants The compositions according to the invention can comprise, as surfactant component, anionic, nonionic, amphoteric or cationic surfactants or surfactant mixtures of one, more than one or all of these classes of surfactant . The compositions comprise surfactants in amounts, based on the composition, of from 0.01 to 30%
by weight, preferably from 0.1 to 20o by weight, in particular from 1 to 14% by weight, most preferably from 3 to 10% by weight.
Anionic surfactants Suitable anionic surfactants are the preferred C6_22-alkyl sulfates, C6-C22-alkyl ether sulfates, i . a .
the sulfation products of the alcohol ethers of the formula II, and/or C6-C22-alkylbenzenesulfonates, in particular dodecylbenzenesulfonate, but also C6-C22-alkanesulfonates, C6-Cz2-a-olefinsulfonates, sulfonated C6-C22-fatty acids, C6-C22-carboxamide ether sulfates, mono-C1-C12-alkyl sulfosuccinate, C6-C22-alkylpolyglycol ether carboxylate, C6-C22-N-aryl taurides, C6-C22-N-sarcosinates and C6-C2z-alkyl isethionates and mixtures thereof. They are used in the form of their alkali metal and alkaline earth metal salts, in particular sodium, potassium and magnesium salts, and also ammonium and mono-, di-, tri- and tetraalkylammonium salts, and in the case of the sulfonates, also in the form of their corresponding acid, e.g.
dodecylbenzenesulfonic acid. If sulfonic acid is used, this is usually neutralized in situ with one or more corresponding bases, e.g. alkali metal and alkaline earth metal hydroxides, in particular sodium, potassium and magnesium hydroxide, and ammonia or mono-, di-, tri- or tetraalkylamine, to give the abovementioned salts. The compositions comprise anionic surfactants in amounts, based on the composition, of from 0 to 30o by _ g -weight, preferably 0.1 to 20o by weight, in particular 1 to 14% by weight, most preferably 2 to 10% by weight.
The use of the particularly preferred alkylbenzenesulfonic acids may, particularly if the content of sodium chloride is high and/or sodium hydroxide is used to adjust the pH, lead to clouding in the region of the boundary layer between phases I and II. Citric acid or citrate already counteracts this problem according to the invention. A further improvement occurs, however, during neutralization of the alkylbenzenesulfonic acid with potassium hydroxide which, in this regard, has a particularly positive effect on the phase separation, the clarity of the phases and the sharpness, and also lack of or freedom from clouding of the phase boundary layer.
Because of their foam-suppressing and thickening properties, the compositions according to the invention can also comprise soaps, i.e. alkali metal or ammonium salts of saturated or unsaturated C6-C2z-fatty acids. The soaps can be used in an amount of up to 5o by weight, preferably from 0.1 to 2o by weight.
Nonionic surfactants Suitable nonionic surfactants are, for example, C6-C22-alkyl alcohol polyglycol ethers, alkyl polyglycosides, and nitrogen-containing surfactants or else di-C1-C12-alkyl sulfosuccinates or mixtures thereof, in particular of the first two. The compositions comprise nonionic surfactants in amounts, based on the composition, of from 0 to 30o by weight, preferably 0.1 to 20% by weight, in particular 0.5 to 14o by weight, most preferably 1 to 10% by weight.
C6-C22-alkyl alcohol polypropylene glycol/polyethylene glycol ethers are preferred known nonionic surfactants. They can be described by the formula II, R10-(CH2CH(CH3)O)p(CH2CH20)e-H, in which R1 is a linear or branched, aliphatic alkyl and/or alkenyl radical having 8 to 22 carbon atoms, p is 0 or a number from 1 to 3, and a is a number from 1 to 20.

The C6-C2z-alkyl alcohol polyglycol ethers of the formula II can be obtained by addition of propylene oxide and/or ethylene oxide to alkyl alcohols, preferably to fatty alcohols. Typical examples are polyglycol ethers of the formula II in which R1 is an alkyl radical having 8 to 22 carbon atoms, p is 0 to 2, and a is a number from 2 to 7. Preferred representatives of, for example, Clo-C14-fatty alcohol+1P0+6E0 ethers (p - 1, a - 6) and ClZ-C18-fatty alcohol+7E0 ethers (p - 0, a - 7), and mixtures thereof .
It is also possible to use terminally capped C6-Cz2-alkyl alcohol polyglycol ethers, i.e. compounds in which the free OH group in the formula II is etherified. The terminally capped C6-C22-alkyl alcohol polyglycol ethers can be obtained by appropriate methods of preparative organic chemistry. Preference is given to reacting C6-C22-alkyl alcohol polyglycol ethers in the presence of bases with alkyl halides, in particular butyl or benzyl chloride. Typical examples are mixed ethers of the formula II in which R1 is a technical-grade fatty alcohol radical, preferably C1zi14-cocoalkyl radical, p is 0, and a is from 5 to 10, which have been capped with a butyl group.
Preferred nonionic surfactants are also alkyl polyglycosides (APG) of the formula III, R20 [G] X, in which RZ is a linear or branched, saturated or unsaturated alkyl radical having 8 to 22 carbon atoms, [G] is a glycosidally linked sugar radical, and x is a number from 1 to 10. APGs are nonionic surfactants and are known substances which can be obtained by the relevant methods of preparative organic chemistry. The index number x in the general formula III gives the degree of oligomerization (degree of DP), i.e. the distribution of mono- and oligoglycosides, and is a number between 1 and 10. While x in a given compound must always be an integer and here can assume in particular the values x = 1 to 6, the value x for a certain alkyl glycoside is an analytically determined arithmetical parameter, which in most cases is a fraction. Preference is given to using alkyl glycosides having an average degree of oligomerization x from 1.1 to 3Ø From a technical viewpoint, preference is given to those alkyl glycosides whose degree of oligomer-ization is less than 1.7 and is in particular between 1.2 and 1.6. The glycosidic sugar used is preferably xylose, but in particular glucose.
The alkyl or alkenyl radical R2 (formula III) can be derived from primary alcohols having 8 to 22, preferably 8 to 14 carbon atoms. Typical examples are caproic alcohol, caprylic alcohol, capric alcohol and undecyl alcohol, and technical-grade mixtures thereof, as are produced, for example, in the course of the hydrogenation of technical-grade fatty acid methyl esters or in the course of the hydrogenation of aldehydes from the ROELEN oxo synthesis.
However, the alkyl or alkenyl radical Rz is preferably derived from lauryl alcohol, myristyl alcohol, cetyl alcohol, palmoleyl alcohol, stearyl alcohol, isostearyl alcohol or oleyl alcohol. Further examples are elaidyl alcohol, petroselinyl alcohol, arachidyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol, and technical-grade mixtures thereof.
Other nonionic surfactants which may be present are nitrogen-containing surfactants, e.g. fatty acid polyhydroxyamide, for example glucamides, and ethoxylates of alkylamines, vicinal diols and/or carboxamides which have alkyl groups containing 10 to 22 carbon atoms, preferably 12 to 18 carbon atoms. The degree of ethoxylation of these compounds is generally between 1 and 20, preferably between 3 and 10.
Preference is given to ethanolamide derivatives of alkanoic acids having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms. Particularly suitable compounds include lauric acid monoethanolamide, myristic acid monoethanolamide and palmitic acid monoethanolamide.

Amphoteric surfactants Suitable amphoteric surfactants are, for example, betaines of the formula (R3) (R4) (RS) N'CH2C00-, in which R3 is an alkyl radical, optionally interrupted by heteroatoms or groups of heteroatoms, having from 8 to 25, preferably from 10 to 21, carbon atoms, and R4 and RS are identical or different alkyl radicals having from 1 to 3 carbon atoms, in particular Clo-C22-alkyl-dimethylcarboxymethylbetaine and Cll-C1.,-alkylamido-propyldimethylcarboxymethylbetaine. The compositions comprise amphoteric surfactants in amounts, based on the composition, of from 0 to 15% by weight, preferably from 0.01 to 10% by weight, in particular from 0.1 to 5o by weight.
Cationic surfactants Suitable cationic surfactants are inter alia the quaternary ammonium compounds of the formula (R6) (R') (R8) (R9) N+X-, in which R6 to R9 are four identical or different, in particular two long-chain and two short-chain, alkyl radicals, and X- is an anion, in particular a halide ion, for example didecyl-dimethylammonium chloride, alkylbenzyldidecylammonium chloride, and mixtures thereof. The compositions comprise cationic surfactants in amounts, based on the composition, of from 0 to loo by weight, preferably from 0.01 to 5o by weight, in particular from 0.1 to 3%
by weight.
In a preferred embodiment, the compositions according to the invention comprise anionic and nonionic surfactants alongside one another, preferably C6-C22-alkylbenzenesulfonates, C6-C22-alkyl sulfates and/or C6-Cz2-alkyl ether sulfates in addition to C6-C2z-alkyl alcohol polyglycol ethers and/or alkyl polyglycosides, in particular C6-C2Z-alkylbenzenesulfonates in addition to C6-C2z-alkyl alcohol polyglycol ethers.
Builders The compositions according to the invention can further comprise one or more builders. Suitable ' - 13 -builders are, for example, alkali metal citrates, gluconates, nitrilotriacetates, carbonates and bicarbonates, in particular sodium citrate, gluconate and nitrilotriacetate, and sodium and potassium carbonate and bicarbonate, and alkali metal and alkaline earth metal hydroxides, in particular sodium and potassium hydroxide, ammonia and amines, in particular mono- and triethanolamine, or mixtures thereof. These also include the salts of glutaric acid, succinic acid, adipic acid, tartaric acid and benzenehexacarboxylic acid, and phosphonates and phosphates, for example sodium hexametaphosphate, such as, for example, a mixture of condensed orthophosphates of the formula I in which n is an average value of about 12. The compositions comprise builders in amounts, based on the composition, of from 0 to 30o by weight, preferably 0.1 to 20% by weight, in particular 1 to 15% by weight, most preferably 2 to loo by weight.
The builder salts additionally act here as phase separation auxiliaries.
A preferred builder is citrate from the group of alkali metal, alkaline earth metal, ammonium and mono-, di- or trialkanolammonium citrates, preferably mono-, di- or triethanolammonium citrates, or mixtures thereof, in particular sodium citrate, most preferably potassium citrate.
A particularly preferred alkaline builder is potassium hydroxide since it has a particularly positive effect on the phase separation, the clarity and color brilliance of the phases, and the sharpness and lack of or freedom from clouding of the phase boundary layer.
If the builder should additionally act as pH
stabilizing buffer, then alkali metal and alkaline earth metal carbonates and bicarbonates, e.g. soda, are preferred.
yiscositv The viscosity of the composition according to the invention is preferably 5 to 1000 mPa~s, in particular 10 to 500 mPa~s, particularly preferably 10 to 200 mPa~s, at 20°C, measured using a rotational viscometer from Brookfield of the LVT type or LVDV-II+
with a small sample adapter at a rate of rotation of 30 min-1, where the spindle used as measurement member is, according to Brookfield, to be chosen such that the moment of rotation is in a favorable range and the measurement range is not exceeded. In this context, spindle 31 is preferred and, if necessary in cases where the viscosities are above about 240 mPa~s, recourse is preferably made to spindle 25.
Thickeners To adjust the viscosity, the composition according to the invention can comprise one or more thickeners, preferably in an amount of from 0 . O1 to 5 0 by weight, in particular 0.05 to 2.5% by weight, particularly preferably 0.1 to to by weight.
Suitable thickeners are organic natural thickeners (agar-agar, carrageen, tragacanth, gum arabic, alginates, pectins, polyoses, guar flour, carob seed grain, starch, dextrins, gelatin, casein), organic modified natural substances (carboxymethylcellulose and other cellulose ethers, hydroxyethylcellulose and hydroxypropylcellulose and the like, bean flour ether), organic completely synthetic thickeners ~(polyacrylic and polymethacrylic compounds, vinyl polymers, polycarboxylic acids, polyethers, polyimines, polyamides) and inorganic thickeners (polysilicic acids, clay minerals, such as montmorillonites, zeolites, silicas).
The polyacrylic and polymethacrylic compounds include, for example, the high molecular weight homopolymers of acrylic acid crosslinked with a polyalkenyl polyether, in particular an allyl ether of sucrose, pentaerythritol or propylene (INCI name according to International Dictionary of Cosmetic Ingredients of The Cosmetic, Toiletry and Fragrance Association (CTFA): Carbomer), which are also referred to as carboxyvinyl polymers. Such polyacrylic acids are ' - 15 -available inter alia from BF Goodrich under the tradename Carbopol~, e.g. Carbopol~ 940 (molecular weight about 4,000,000), Carbopol~ 941 (molecular weight about 1,250,000) or Carbopol~ 934 (molecular weight about 3,000,000). They also include the following acrylic acid copolymers: (i) copolymers of two or more monomers from the group of acrylic acid, methacrylic acid and its monoesters preferably formed with C1_4-alkanols (INCI Acrylates Copolymer), to which, for example, the copolymers of methacrylic acid, butyl acrylate and methyl methacrylate (CAS name according to Chemical Abstracts Service: 25035-69-2) or of butyl acrylate and methyl methacrylate (CAS 25852-37-3) belong, and which are available, for example, from Rohm & Haas under the tradenames Aculyn~ and Acusol~, e.g.
the anionic nonassociative polymers Aculyn~ 33 (crosslinked), Acusol~ 810 and Acusol~ 830 (CAS 25852-37-3); (ii) crosslinked high molecular weight acrylic acid copolymers, to which, for example, the copolymers of Clo_3o-alkyl acrylates, crosslinked with an allyl ether of sucrose or of pentaerythritol, with one or more monomers from the group of acrylic acid, methacrylic acid or its monoesters preferably formed with C1_4-alkanols (INCI Acrylates/C10-30 Alkyl Acrylate Crosspolymer) belong and which are available, for example, from BF Goodrich under the tradename Carbopol~, e.g. the hydrophobicized Carbopol~ ETD 2623 and Carbopol~ 1382 (INCI Acrylates/C10-30 Alkyl Acrylate Crosspolymer), and Carbopol~ AQUA 30 (previously Carbopol~ EX 473).
Preferred thickeners are the polysaccharides and heteropolysaccharides, in particular the polysaccharide gums, for example gum arabic, agar, alginates, carrageens and their salts, guar, guaran, tragacanth, gellan, ramsan, dextran or xanthan, and their derivatives, e.g. propoxylated guar, and their mixtures. Other polysaccharide thickeners, such as starches or cellulose derivatives, can be used as alternatives, although it is preferable to use them in addition to a polysaccharide gum, for example starches from a wide variety of origins and starch derivatives, e.g. hydroxyethylstarch, starch phosphate esters or starch acetates, or carboxymethylcellulose or its sodium salt, methyl-, ethyl-, hydroxyethyl-, hydroxypropyl-, hydroxypropyl-methyl- or hydroxyethyl-methyl-cellulose or cellulose acetate.
A particularly preferred polymer is the microbial anionic heteropolysaccharide xanthan gum, which is produced by Xanthomonas campestris and a few other species under aerobic conditions and has a molecular weight of from 2 to 15 x 106, and is available, for example, from Kelco under the tradename Keltrol~, e.g. as a cream-colored powder Keltro3~ T
(Transparent) or as white granules Keltrol~ RD (Readily Dispersable).
Auxiliaries and additives In addition to said components, the compositions according to the invention can comprise further auxiliaries and additives, as are customary in compositions of this type. These include, for example, perfume and fragrances, polymers, soil-release active ingredients, solvents (e. g. ethanol, isopropanol, glycol ether), solubilizers, hydrotropic agents (e. g.
cumenesulfonate, octyl sulfate, butyl glucoside, butyl glycol), cleaning promoters, disinfectants, antistats, preservatives, bleaching systems, enzymes and dyes, and opacifiers and also skin protectants, as are described in EP-A-522 556. The amount of such additives in the cleaner is usually no more than 12o by weight. The lower use limit depends on the type of additive and can, for example in the case of dyes, be up to O.OOlo by weight and below. The amount of auxiliaries is preferably between 0.01 and 7% by weight, in particular 0.1 and 4o by weight.
Preferred auxiliaries and additives are perfume and fragrances, and dyes, since the perfume and the fragrances, as well as the scent effect, usually also aid phase separation, while by adding dyes the phases can be colored differently, which makes it easier to see the separate phases and also to monitor emulsion formation and separation, thus making the composition even easier to handle.
The compositions according to the invention can be prepared by blending directly from their raw materials, subsequently mixing thoroughly and finally allowing the composition to stand for separation of the temporary emulsion.
The reversible phase separation is brought about, and its characteristics are determined, by the complex interplay of a number of components. The surfactant present can, together with the acid, on its own lead to the phase separation according to the invention. In some cases, only the additional use of hydrophobic component, builder and/or perfume effects phase separation. In other cases, the use of phase-separation auxiliaries is required.
Embodiments of the invention are described by reference to the following specific Examples which are not to be construed as limiting.
Examples The composition E1 according to the invention was prepared as described above. Table 1 gives its composition in % by weight, its pH and also the quantified volume ratio of the lower phase I to the upper phase II.
Table 1 Composition [~ by wt.] El Clo-13-alkylbenzenesulfonic acid 4 Cl2-22-fatty alcohol+7E0 ether 2 Citric acid~1H20 12.7 Potassium hydroxide 6.6 Dioctyl ether 5 Xanthan, transparent (Keltrol~ T) 0.3 Perfume 0 . 7 Water ad 100 pH 4 Phase I: phase II volume ratio 60:40 The composition thus exhibited two continuous phases which temporarily formed a creamy-looking emulsion upon shaking. Even after repeated shaking, separate phases formed again upon standing.
The storage stability was tested by assessing the composition after storage for four weeks at room temperature of 20°C, at elevated temperature of 40°C
and in the cold at a temperature of 5°C. Irrespective of the storage temperature, there was no visible change in the composition and, in particular, as before, it was possible to reversibly convert the composition into the temporary emulsion by shaking.
The composition was judged by test subjects to be visually pleasing and easy to handle and achieved good cleaning results both in the bathroom and in the kitchen - in neat and in dilute form - in particular in the removal of lime and water spots, and grease-containing soilings in the form of the rings of dirt which are left in the bathtub following a bath after the bathing water has drained away, and the soiling which arises in the kitchen as a result of the preparation of fat- or oil-containing foods.

Claims

1. An aqueous liquid multiphase surfactant-containing cleaner having at least two continuous phases, which has at least one lower aqueous phase I
and an upper aqueous phase II immiscible with the first phase and which can be temporarily converted into an emulsion by shaking, which comprises at least one acid and, in the form of the temporary emulsion, has a pH of less than 7.

2. The composition as claimed in claim 1, which comprises at least one inorganic acid or organic acid.

3. A composition as claimed in claim 2, wherein said inorganic acid is a mineral acid.

4. A composition as claimed in claim 2, wherein said organic acid is selected from saturated or unsaturated C1-6-mono-, -di- and -tricarboxylic acid or -hydroxycarboxylic acid having one or more hydroxyl groups, amidosulfuric acid, C6-22-fatty acid or anion-active sulfonic acid, or one of their mixtures.

5. The composition as claimed in any one of claims 2 to 4, which comprises citric acid and/or one or more anion-active sulfonic acids.

6. A composition as claimed in claim 5, wherein the anion-active sulfonic acids are alkylarenesulfonic acids.

7. The composition as claimed in any one of claims 5 or 6, which comprises, as anion-active sulfonic acids, C1-22-alkyl-C6-10-arenesulfonic acids.

8. A composition as claimed in claim 7, wherein said sulfonic acids are selected from C1-22-alkyl-benzenesulfonic acids or C1-22-alkylnaphthalenesulfonic acids.

9. A composition as claimed in claim 7, wherein said sulfonic acid is selected from linear C8-16-alkylbenzenesulfonic acids.

10. A composition as claimed in claim 7, wherein said sulfonic acids are selected from linear C10-14-alkyl-C10-13-alkyl- or C12-alkylbenzenesulfonic acids.

11. The composition as claimed in any one of claims 1 to 10, which additionally comprises one or more alkalis.

12. The composition as claimed in claim 11, wherein said alkali is potassium hydroxide.

13. The composition as claimed in any of claims 1 to 12, wherein the continuous phases I and II are delimited from one another by a sharp interface.

14. The composition as claimed in any one of claims 1 to 13, wherein one or both of the continuous phases I
and II comprise 0.1 to 25% by volume, based on the volume of the respective continuous phase, of the other phase in each case as dispersant.

15. The composition as claimed in any one of claims 1 to 14, wherein one or both of the continuous phases I
and II comprise 0.2 to 15% by volume, based on the volume of the respective continuous phase, of the other phase in each case as dispersant.

16. The composition as claimed in any one of claims 1 to 15, wherein phase I is emulsified in phase II in amounts of from 0.1 to 25% by volume, based on the volume of phase II.

17. The composition as claimed in claim 16, wherein phase I is emulsified in phase II in amounts of from 0.2 to 15% by volume, based on the volume of phase II.

18. The composition as claimed in any one of claims 1 to 17, wherein, in addition to the continuous phases I and II, part of the two phases is in the form of an emulsion of one of the two phases in the other phase, this emulsion being delimited by two sharp interfaces, one upper and one lower, from the parts of phases I and II not involved in the emulsion.

19. The composition as claimed in any one of claims 1 to 18, which comprises phase I and phase II in a volume ratio of from 90:10 to 10:90.

20. The composition as claimed in claim 19, which comprises phase I and phase II in a volume ratio of from 75:25 to 25:75.

21. The composition as claimed in claim 20, which comprises phase I and phase II in a volume ratio of from 65:35 to 35:65.

22. The composition as claimed in any one of claims 1 to 21, which additionally comprises hydrophobic components from the group of dialkyl ethers having identical or different C4- to C14-alkyl radicals, hydrocarbons having a boiling range from 100 to 300°C, essential oils, and mixtures thereof.

23. The composition as claimed in claim 22, wherein said dialkyl ether is dioctyl ether.

24. The composition as claimed in claim 22, wherein said hydrocarbons have a boiling range from 140 to 280°C.

25. The composition as claimed in claim 22, wherein said essential oil is selected from limonene and pine oil.

26. The composition as claimed in claim 22, wherein said mixtures comprise mixtures of two or three of said hydrophobic components.

27. The composition as claimed in any one of claims 1 to 26, which additionally comprises phase-separation auxiliaries.

28. The composition as claimed in claim 27, wherein said phase-separation auxiliaries are selected from the group of alkali metal and alkaline earth metal chlorides and sulfates.

29. The composition as claimed in claim 28, wherein said phase-separation auxiliaries are selected from the group of sodium and potassium chloride and sulfate, and ammonium chloride and sulfate, and mixtures thereof.

30. The composition as claimed in any one of claims 1 to 29, which comprises anionic surfactant.

31. The composition as claimed in claim 30, wherein said anionic surfactant is selected from the group of C6-C22-alkyl sulfates, C6-C22-alkyl ether sulfates and C6-C22-alkylbenzenesulfonates, and mixtures thereof.

32. The composition as claimed in claim 30 or 31, which comprises at least one anionic surfactant in the form of its potassium salt.

33. The composition as claimed in any one of claims 1 to 32, which comprises nonionic surfactant.

34. The composition as claimed in claim 33, wherein said nonionic surfactant is selected from the group of the C6-C22-alkyl alcohol polyglycol ethers, the alkyl polyglycosides and mixtures thereof.

35. The composition as claimed in any one of claims 1 to 34, which comprises anionic and nonionic surfactant.

36. The composition as claimed in claim 35, comprising C6-C22-alkylbenzenesulfonates, C6-C22-alkyl sulfates and/or C6-C22-alkyl ether sulfates in addition to C6-C22-alkyl alcohol polyglycol ethers and/or alkyl polyglycosides.

37. The composition as claimed in claim 36, comprising C6-C22-alkylbenzenesulfonates in addition to C6-C22-alkyl alcohol polyglycol ethers.

38. The composition as claimed in any one of claims 1 to 37, which comprises one or more cationic surfactants.

39. The composition as claimed in any one of claims 1 to 38, which additionally comprises builders.

40. The composition as claimed in claim 39, wherein said builders are selected from the group of alkali metal citrates, gluconates, nitrilotriacetates, carbonates and bicarbonates, and alkali metal and alkaline earth metal hydroxides, ammonia and amines and mixtures thereof.

41. The composition as claimed in claim 39 or 40, which comprises citrate from the group of alkali metal, alkaline earth metal, ammonium and mono-, di- or trialkanolammonium citrates, or mixtures thereof.

42. The composition as claimed in claim 41, comprising mono-, di- and triethanolammonium citrates.

43. The composition as claimed in claim 41, comprising sodium citrate.

44. The composition as claimed in claim 41, comprising potassium citrate.

45. The composition as claimed in claims 39 to 44, which comprises potassium hydroxide as an additional builder.

46. A process for the preparation of a composition as claimed in any one of claims 1 to 45 by blending directly from its raw materials, subsequently mixing thoroughly and finally allowing the composition to stand for separation of the temporary emulsion.

47. The use of a composition as claimed in any one of claims 1 to 45 for the cleaning of hard surfaces.