EP2828370B1 - Microemulsion-based cleaning agent - Google Patents

Description

The invention relates to aqueous microemulsions, their use as cleaning agents, in particular for the removal of polymer-like soils, such as, for example, paint residues, as well as a method for cleaning using the aqueous microemulsion.

Detergents usually get their effectiveness in that they are specially designed for the soiling to be cleaned. A cleaner for water-soluble contaminants is typically water-based, whereas a cleaner for oily soils is typically oil-based. A cleaner that works against both types of soiling consists of water, an oil and at least one surfactant, so that emulsions can form.

Surfactants are washing-active substances (detergents) which are contained in detergents, dishwashing detergents and shampoos. They have a characteristic structure and have at least one hydrophilic and one hydrophobic structural unit. They have an amphiphilic character. If the stabilizing character of water-in-oil mixtures is in the foreground, these amphiphilic substances are used as emulsifiers.

Surfactants lower the interfacial tension between immiscible phases, a hydrophilic (water-soluble, lipophobic), mostly aqueous phase, and a hydrophobic (oil-soluble, lipophilic) phase.

Such aqueous two-phase mixtures are referred to as emulsions.

Conventional emulsions may contain hydrophilic and hydrophobic phases in different volumes. They have a continuous and a disperse phase, which is a very small droplet stabilized by surfactant occupancy, in the continuous phase. Depending on the nature of the continuous phase, it is referred to as oil-in-water or water-in-oil emulsions.

Basically, a distinction is made between emulsions and microemulsions. While microemulsions are thermodynamically stable, emulsions separate into two phases due to their instability. At the microscopic level, this difference is reflected in the fact that the emulsified liquids in microemulsions generally have smaller structure sizes than in emulsions, such as in DE 10 2005 049 765 A1 described. Thermodynamically unstable emulsions thus have larger structures.

In microemulsions lamellar mesophases can occur. Lamellar mesophases lead to optical anisotropy and possibly increased viscosity. These properties are e.g. undesirable for cleaners. In addition, phase separation occurs when lamellar phases coexist with microemulsions.

Microemulsions consist of at least three components, namely oil, water and a surfactant. The surfactant mediates between these two components and allows a macroscopic-homogeneous mixture. On a microscopic scale, the surfactant forms a film between the oil and water domains. Oil and water are immiscible and therefore form domains on the nanoscale. Microemulsions are macroscopically homogeneous, behave optically isotropically and are thermodynamically stable in contrast to emulsions. There are W / O and O / W droplet microemulsions where water droplets from the oil or oil droplets are enclosed by the water. Approximately equal proportions of oil to water promote the formation of a bicontinuous microemulsion. Characteristic of the efficiency of a surfactant is the minimum amount of surfactant required to obtain a microemulsion.

Microemulsions are intensively studied in the field of basic science. The knowledge gained is largely based on the use of pure, defined components: deionized water, chemically pure oils and pure surfactants. In technical microemulsions, the components usually consist of mixtures. As a result, the phase ratio changes considerably and the findings from basic research gained in simplified models can not be readily obtained technical applications are transmitted. Another difficulty lies in the low temperature stability of microemulsions, since in practical formulations the stability must be present over a wide temperature range in order to ensure safe storage, transport and application. Especially systems based on the frequently used fatty alcohol ethoxylates are only stable in a very narrow temperature window of a few degrees Celsius or must have extremely high surfactant concentrations in order to be stable over larger temperature ranges. On the other hand, microemulsions prepared with the aid of sugar surfactants can be stable over larger temperature ranges ( WO 2008/132202 A1 ). Similarly, mixtures of nonionic and ionic surfactants can be used. Here, one makes use of the complementary temperature behavior of the nonionic and ionic surfactants. However, the development of microemulsions, which are sensitive to the setting of their parameters, and at the same time stable as well as a high cleaning performance, especially with regard to water-insoluble or only very sparingly soluble substances, is a particular challenge.

At the same time, environmental aspects and health aspects play an increasingly important role, so that it is important to use surfactants that contain a low potential for hazardous substances. For technical applications, this can be of great importance, since in conventional microemulsions surfactant contents of 20 to 30% are the rule in order to achieve a sufficiently extended temperature stability. In such concentrations surfactants have a non-negligible hazard potential.

Conventional cleaners which are used in the commercial and private sector, for example as brush cleaners or adhesive removers, consist essentially of low-boiling mixtures of aliphatic and aromatic hydrocarbons or other organic solvents to which surfactants are often added. These cleaners are highly harmful to health and harmful to the environment. In addition, conventional cleaners are often highly alkaline, which can attack the substrates to be cleaned.

In addition, conventional cleaners have a strong degreasing effect on contact with the skin and also have a strong odor.

Technically usable microemulsions are already known in the prior art. So describes DE 10 2005 049 765 in general a process for cleaning with microemulsions by means of hydrophilic polymeric additives.

US 6,165,962 describes microemulsions containing sodium salts of sulfosuccinic acid esters, C ₂ -C ₁₀ diols and oil. The oil component may be an ester. The microemulsions can contain other solvents and are suitable as a cleaner for degreasing or paint stripping.

US 2009/0093390 . US 7,018,969 . US 2005/0130869 and WO 2006/004721 describe microemulsion formulations for cleaning hard surfaces which, in addition to ester oils, also contain polar solvents as well as surfactants and cosurfactants.

US 2004/0038847 and WO 00/52128 describe microemulsions for cleaning hard surfaces, which in addition to ester oils contain polar solvents and as surface-active component anionic surfactants.

EP 1 780 259 describes microemulsions for cleaning hard surfaces, which in addition to dibasic esters contain polar solvents as well as anionic surfactants.

The microemulsions based on ester oils described in the prior art require further solvents for stabilizing the microemulsion or for achieving the cleaning performance and are thus generally not free from labeling according to current German legislation.

The object of the present invention was to provide environmentally friendly microemulsions which are stable over a wide temperature range, have a low amount of surfactant and, moreover, have an outstanding cleaning performance, in particular with regard to Farbanschmutzungen, oily and greasy soiling and soiling, the organic components are polymer-based and are particularly preferred no labeling according to current German legislation.

The object of the present invention was therefore to remedy the problems identified in the prior art.

It has surprisingly been found that the problem can be solved by a special microemulsion.

1. a) einen oder mehrere flüssige Carbonsäureester zur Ausbildung einer Ölkomponente,
2. b) ein oder mehrere wasserlösliche(s) Salz(e) mit einem oder mehreren Kationen, vorzugsweise ausgewählt aus der Gruppe bestehend aus Natrium, Kalium, Calcium, Magnesium und Ammonium,
3. c) ein oder mehrere Salz(e) von Sulfobernsteinsäureester,
4. d) ein oder mehrere nichtionische(s) Tensid(e) ausgewählt aus alkoxyliertem Sorbitanester und alkoxyliertem Pflanzenöl, und
5. e) einem oder mehreren Booster(n) in Form eines hydrophilen polymeren Additivs, bestehend aus einer wasserlöslichen Einheit, die an mindestens einem Kettenende eine hydrophobe, wasserunlösliche Gruppe mit einem Molekulargewicht von 80 bis 500 g/ mol aufweist und das Molmassenverhältnis der wasserlöslichen Einheit zur hydrophoben, wasserunlöslichen Gruppen 7 bis 200 beträgt; oder der Booster ein Alkoholethoxylat aus einem C₈-C₂₀ Alkohol mit 25 bis 200 Ethoxy-Gruppen ist.

The present invention is an aqueous microemulsion comprising

1. a) one or more liquid carboxylic acid esters for the formation of an oil component,
2. b) one or more water-soluble salt (s) having one or more cations, preferably selected from the group consisting of sodium, potassium, calcium, magnesium and ammonium,
3. c) one or more salts of sulfosuccinic acid ester,
4. d) one or more nonionic surfactant (s) selected from alkoxylated sorbitan ester and alkoxylated vegetable oil, and
5. e) one or more booster (s) in the form of a hydrophilic polymeric additive consisting of a water-soluble unit having at least one chain end a hydrophobic, water-insoluble group having a molecular weight of 80 to 500 g / mol and the molecular weight ratio of the water-soluble unit to hydrophobic, water-insoluble groups is 7 to 200; or the booster is an alcohol ethoxylate of a C ₈ -C ₂₀ alcohol having from 25 to 200 ethoxy groups.

The cleaning performances of the microemulsions according to the invention are essentially the same as those of the solvent-based cleaners. However, the microemulsions according to the invention also have a wider range of applications. They are useful, for example, for removing fresh or dried water-based inks. Such colors are usually removed with water, but this can lead to resin residues or residues of dried-on paint. Resin residues can stick eg brush hairs. The microemulsions according to the invention are also suitable for removing water-soluble inks without leaving residual resin. Dried paint is removed, which is not possible with water. Conventional brush cleaners are only suitable for cleaning solvent based paints, they are not suitable for water based paints. The Microemulsions according to the invention are furthermore advantageous if long exposure times are necessary, for example in order to remove dried soiling. Conventional cleaners are not suitable here because the organic solvents evaporate quickly.

In addition, it has been found that the microemulsions according to the invention are readily dilutable with water while retaining their microemulsion property. This allows you to be used with more easily removable dirt, diluted with water. In addition, detergent residues can be easily removed with water.

In addition, it has surprisingly been found that the microemulsions according to the invention, in contrast to conventional cleaners after contact with skin and after washing, leave a pleasant feeling on the skin. In addition, the microemulsions according to the invention are essentially odorless.

The microemulsions according to the invention are also distinguished by the fact that they require only a small amount of surfactant and are stable over a relatively wide temperature range. In a preferred embodiment, the microemulsion according to the invention is substantially free of volatile organic compounds (VOCs). According to the 31st Ordinance on the Implementation of the Federal Emission Protection Law (31st BimschV, § 2, no. 11), the VOC is a volatile organic compound which has a vapor pressure of 0.01 kPa or more at 293.15 K. VOCs include e.g. Compounds of the substance groups alkanes / alkenes, aromatics, terpenes, halogenated hydrocarbons, ethers, esters, aldehydes and ketones.

Preferably, the microemulsion of the present invention is substantially free of organic solvents, especially VOCs. Substantially free in the context of the present invention means that the microemulsion is less than 10% by weight, preferably less than 5% by weight, more preferably less than 2% by weight, more preferably less than 1% by weight, in particular less than 0.5% by weight, and in particular completely free.

The aqueous microemulsion according to the invention comprises as essential components the components a) to e).

Component a)

The aqueous microemulsion according to the invention comprises as component a) one or more liquid carboxylic acid esters, which are also referred to below as "ester oils". The ester oil forms the oil component in the microemulsion. Ester oils have the advantage that they are non-polar and have a lipophilic character, which makes them particularly suitable for oily soiling and, in particular, for soiling whose organic constituents are polymer-based. In addition, they have a high boiling point and are therefore volatile. Suitable liquid carboxylic esters have a melting point which is below 20 ° C, i. the liquid carboxylic esters are liquid at 20 ° C.

Suitable carboxylic acid esters have 6 to 40 carbon atoms, preferably 6 to 22 and especially 10 to 22 carbon atoms.

The ester oil may contain saturated, unsaturated or aromatic radicals.

Particularly preferred are liquid carboxylic acid esters selected from the group consisting of esters of monohydric alcohol and mono- or dicarboxylic acid and esters of dihydric alcohol and monocarboxylic acid.

Particularly preferred are the esters of monohydric alcohols with monocarboxylic acids.

Good results have been achieved with liquid carboxylic acid esters, wherein the ester is a C ₁₀ -C ₂₂ monocarboxylic acid and methanol, preferably methyl dodecanoate or rapeseed oil methyl ester.

Further preferred are liquid carboxylic acid esters which have a mixture of monocarboxylic acids having 10 to 22 carbon atoms and dicarboxylic acid methyl ester having 6 to 10 carbon atoms.

In a particularly preferred embodiment, the ester oil comprises one or more components selected from the group consisting of rapeseed oil methyl ester, octyloctanoate, oleic acid ethyl ester, methyl laurate, dimethyl succinate, dimethyl adipate, dimethyl glutarate and isopropyl myristate.

In a preferred embodiment, the aqueous microemulsions of the present invention comprise the liquid carboxylic acid ester in an amount of 10 to 40% by weight, preferably 20 to 35% by weight, based in each case on the total weight of the microemulsion.

In order to obtain a balanced microemulsion adjusted to the other components and having a high performance, it has proved to be advantageous, the weight ratio of the liquid carboxylic ester (component a)) to the sum of components c), d) and e) to 1.5 to 10 , preferably 2.5 to 8, in particular 3 to 8 or 4 to 8 set.

Component b)

The aqueous microemulsions according to the invention have as component b) one or more water-soluble salt (s) with one or more cations, preferably selected from the group consisting of sodium, potassium, calcium, magnesium and ammonium.

In the context of the present invention salts are water-soluble, if at least 1 g of salt per liter of water at 20 ° C can be completely dissolved. Preference is given to the alkali metal or alkaline earth metal or ammonium salts.

It has been found that by suitable choice of salts, the formation of the microemulsion and its temperature stability window can be controlled. Without the presence of salt, either a very large proportion of surfactant in the Emulsion necessary or the microemulsion is stable in a temperature range irrelevant for the application. By using the salt can therefore be advantageous to reduce the amount of surfactant, which in addition to the environmental benefits also brings cost advantages. The amount of surfactant is in turn a balancing act, because with a larger amount of surfactant and the temperature range in which the microemulsion is stable, broader.

As counterions, both inorganic and organic anions are suitable. Preferred inorganic anions are selected from the group consisting of sulfate, chloride, hydrogen sulfate, phosphate and hydrogen sulfate.

Preferred organic anions are selected from the group consisting of acetate, gluconate, citrate and tartrate.

In a particularly preferred embodiment of the present invention, component b) is a water-soluble salt selected from the group consisting of sodium sulfate, sodium chloride, sodium gluconate, sodium citrate, trisodium phosphate, disodium hydrogen phosphate, potassium sulfate, potassium chloride, ammonium sulfate, ammonium chloride, magnesium sulfate, magnesium chloride, calcium chloride, calcium acetate , Magnesium acetate and potassium sodium tartrate.

Surprisingly good results could be achieved with acetate salts. In a particularly preferred embodiment, the microemulsions according to the invention comprise calcium acetate and / or magnesium acetate.

To adjust the temperature window and to optimize the cleaning performance of the microemulsion according to the invention, the salt is typically present in an amount of from 0.1 to 4% by weight, preferably from 0.25 to 3% by weight, based in each case on the total weight of the microemulsion ,

Component c)

The aqueous microemulsion according to the invention additionally contains component c), which is one or more salts of sulfosuccinic acid ester.

In a preferred embodiment, the salt of the sulfosuccinic acid esters is an alkali metal salt, especially a sodium salt. The salt of sulfosuccinic acid esters acts as an anionic surfactant. In particular, sulfosuccinic acid ester salts having C ₆ -C ₁₂ -alcohol radicals have been found to be present in the microemulsions according to the invention. The sulfosuccinic ester salt used contributes significantly to the stability of the microemulsion according to the invention. Particular preference is given to the salts of the sulfosuccinic esters selected from the group consisting of diesters of sulfosuccinic acid alkali salt with C ₆ -C ₁₀ -alcohols, monoesters of sulfosuccinic acid dialkali salt with C ₈ -C ₁₂ -alcohols and monoesters of sulfosuccinic acid dialkali salt with ethoxylated C ₁₀ -C ₁₄ -alcohols.

In one embodiment, the diester of the sulfosuccinic acid alkali salt is present as a diester having at least one, preferably two, ethoxylated C ₁₀ -C ₁₄ alcohol radicals.

The alcohol residues can be linear or branched. In a particularly preferred embodiment, the salt of the sulfosuccinic acid esters is the sodium salt of sulfosuccinic acid bis-2-ethylhexyl ester.

For setting an optimum aqueous microemulsion according to the invention, the salts of the sulfosuccinic acid esters are typically present in an amount of from 1 to 10% by weight, preferably in an amount of from 1.5 to 5% by weight or from 2.0 to 5.0% by weight. %, in each case based on the total weight of the microemulsion.

Based on the total weight of components c), d) and e), the salt of the sulfosuccinic acid esters is typically present in an amount of from 30 to 75% by weight, preferably in an amount of from 40 to 70% by weight.

Component d)

As a further essential component, the microemulsions according to the invention have the component d), which is one or more nonionic surfactant (s) selected from alkoxylated sorbitan ester and alkoxylated vegetable oil.

In a preferred embodiment, the nonionic surfactant is selected from ethoxylated sorbitan ester and / or ethoxylated vegetable oil.

Preferred sorbitan esters are the sorbitan monoesters, in particular those sorbitan monoesters which have a saturated or unsaturated, linear or branched fatty acid radical.

In principle, it is possible to use alkoxylated sorbitan esters which may be, for example, propoxylated and / or ethoxylated. However, ethoxylated sorbitan esters are particularly preferred, in particular those sorbitan esters which are provided on average with 3 to 30, preferably 4 to 20, ethoxylate groups.

In a preferred embodiment, the nonionic surfactant is an ethoxylated sorbitan monoester having a saturated or unsaturated C ₁₂ -C ₁₈ fatty acid residue.

In a further embodiment, the nonionic surfactant is an alkoxylated, in particular ethoxylated castor oil.

In a preferred embodiment of the present invention, the degree of ethoxylation of the ethoxylated sorbitan ester and / or the ethoxylated vegetable oil is adjusted so that the HLB value is from 11 to 17, more preferably 12 to 16 or 13 to 16.

wobei

• M_h = Molmasse des hydrophilen Anteils eines Moleküls und
• M = Molmasse des gesamten Moleküls ist.

The HLB value is calculated according to Griffin as follows: $$\mathrm{HLB}=\mathrm{20}*{\mathrm{M}}_{\mathrm{H}}/\mathrm{M}.$$

in which

• M _h = molecular weight of the hydrophilic portion of a molecule and
• M = molecular weight of the entire molecule.

( Griffin, WC Classification of Surface Active Agents by HLB, J. Soc. Cosmet. CHEM. 1, 1949 ).

In a specific embodiment, the nonionic surfactant is selected from the group consisting of polyoxyethylene (4) sorbitan monolaurate, polyoxyethylene (20) sorbitan monopalmitate and polyoxymethylene (20) sorbitan monooleate.

The nonionic surfactant is preferably in an amount of 1.0 to 7.0% by weight, more preferably 1.5 to 5.0% by weight or 1.0 to 5.0% by weight, based on the Total weight of the microemulsion before.

In a particularly preferred embodiment, the nonionic surfactant is present in an amount of from 10 to 70% by weight or from 20 to 60% by weight, preferably in an amount of from 15 to 60% by weight or from 23 to 55% by weight. %, in each case based on the total weight of components c), d) and e).

Component e)

As a further component e), the aqueous microemulsions according to the invention contain one or more boosters.

The boosters used serve to increase the surfactant efficiency in the microemulsions according to the invention. In addition, the boosters help to increase the temperature range in which the microemulsions are stable. The boosters of the present invention are routinely designed to increase the stability of the microemulsions by stiffening the interface.

According to the invention, boosters are used which consist of at least one water-soluble unit which has at least one hydrophobic unit at least at one chain end and / or has a hydrophobic unit as non-terminal substituent.

The booster is in the form of a polymer. Throughout the polymer booster the hydrophilic character predominates. Due to the hydrophobic moiety or moieties, the polymers in water preferentially form micelles. Suitable boosters are for example in the DE 198 39 054 and DE 10 2005 049 765 described.

The water-soluble unit of the booster is not limited in its design to certain types of structures, but it is according to the invention on the combination of the larger water-soluble unit with the hydrophobic units or on.

The water-soluble unit of the polymer is preferably linear, but star-shaped, branched or other types of structures are also possible. Linear means in polymers that the atoms forming the backbone of the chain are a linear unit.

The water-soluble unit may be nonionic or ionic, that is, a polyelectrolyte. The electrical charges may be on any part of the water-soluble component of the polymer. Structures are also conceivable which are composed of at least one ionic and one nonionic fraction.

By way of example, but not limitation, the water-soluble units can consist of the following monomers or mixtures thereof of at least two components: ethylene oxide, vinylpyrrolidine, acrylic acid, methacrylic acid and maleic anhydride.

The water-soluble portion of the polymeric additive is preferably a polyethylene oxide or polyethylene glycol. Further examples are copolymers of ethylene oxide and propylene oxide, polyvinyl alcohol and its water-soluble derivatives. Also suitable are polyvinylpyrrolidone, polyvinylpyridine, polymaleic anhydride, polymaleic acid, polyacrylic acid, polymethacrylic acid, polystyrenesulfonic acid and their water-soluble salts.

The water-soluble units are preferably linear.

The molecular weight distribution of the water-soluble unit defined by the ratio of the weight-average molecular weight and the number-average molecular weight is preferably ≦ 1.2.

The number-average molecular weight of the water-soluble unit of the polymeric additive is preferably between 500 and 20,000 g / mol, more preferably 1,000 to 7,000 g / mol, or between 1300 and 5000 g / mol.

Preference is given to a linear, water-soluble polymer which carries a hydrophobic group at one end of the chain.

In a manner similar to the water-soluble portion of the polymeric additive, the hydrophobic unit design is not limited to selected types of structures. Rather, here too, only the hydrophobic or water-insoluble properties of this unit are important.

Preferred molecular sizes for the hydrophobic moiety are 110-500 g / mol, more preferably 110 to 280 g / mol.

The hydrophobic units consist of non-water-soluble residues. These are preferably alkyl radicals which preferably contain between 6 and 50 carbon atoms, more preferably between 8 and 20 carbon atoms. The radicals can also contain aromatic groups or carbon double or triple bonds, they can be linear or branched be. In addition to hydrocarbon radicals, any other hydrophobic organic radicals which contain, for example, oxygen, nitrogen, fluorine or silicon atoms can also be used. The hydrophobic moiety may also be a polymer.

The hydrophobic moiety may be a residue of defined structure and molecular weight, such as alkyl groups. Also mixtures of substances, such as occur in technical products, are possible. However, it can also be a polymeric radical, such as polybutylene oxide.
The water-soluble moiety of the polymer carries a hydrophobic moiety on at least one chain end.

At each chain end more than one hydrophobic unit is possible.
The water-soluble moiety of the polymer may carry a hydrophobic moiety in a non-chain end position.

Furthermore, hydrophobic moieties of the polymeric booster may be incorporated at least at one location between the water-soluble moieties such that the water-soluble moieties of the polymer are interrupted by hydrophobic moieties.

All combinations of the listed structural types are possible.

The ratio of the molecular weights of water-soluble part to hydrophobic part is 7-200, preferably 7-50.

In the preferred form, the water-soluble unit of the booster is a linear polymer and carries a hydrophobic moiety at one chain end.

• durch Ethoxylierung von C₈-C₂₀ - Alkoholen erhaltene Alkylethoxylate,
• an beiden Kettenenden hydrophob modifiziertes Polyethylenglokol, das z.B. durch Umsetzung von Polyethylenglykol mit C₈-C₂₀ Isocyanaten oder C₈-C₂₀-Säurechloriden erhalten werden kann,
• AB Diblockcopolymere, ABA oder BAB Triblockcopolymere aus 1,2 Butylenoxid und Ethylenoxid.

By way of example, the following polymeric boosters can be listed:

• alkyl ethoxylates obtained by ethoxylation of C ₈ -C ₂₀ alcohols,
• hydrophobically modified polyethylene glycol, which can be obtained, for example, by reaction of polyethylene glycol with C ₈ -C ₂₀ isocyanates or C ₈ -C ₂₀ -acid chlorides, at both chain ends,
• AB diblock copolymers, ABA or BAB triblock copolymers of 1,2 butylene oxide and ethylene oxide.

Particularly effective and at the same time biodegradable are the alkyl ethoxylates obtained by ethoxylation of C ₈ -C ₂₀ -alcohols.

Due to the hydrophobic units, the booster in water prefers to form micelles.

In one embodiment, a hydrophobic moiety is located at either end of the water soluble moiety.

As boosters according to the invention, preference is given to linear water-soluble polymers which have a hydrophobic unit only at one chain end. Within this type of structure, preference is given to alcohol ethoxylates which have a high degree of ethoxylation. These substances can be considered as polyethylene oxide with a hydrophobic alkyl radical or be regarded as long-chain or hydrophilic emulsifiers. As hydrophobic components, for example, aliphatic alcohols or alkylphenols can be used, which preferably have 8-20 carbon atoms. The alcohol ethoxylates contain from 25 to 500 moles per mole of alcohol, more preferably from 50 to 200 moles of ethylene oxide. An example is the commercially available compound Brij S 100-PA (SG) from Croda.

In the polymeric booster, the proportion of water-soluble units which are not linked to hydrophobic units should be as low as possible, that is to say, for example, ≦ 20% by weight.

In a preferred embodiment, the booster is in the form of a hydrophilic polymeric additive consisting of a water-soluble unit having at one end of a chain a hydrophobic, water-insoluble group with a Molecular weight of 80 to 500 g / mol and wherein preferably the mass ratio of the water-soluble unit to the hydrophobic, water-insoluble groups is 5 to 200. In one embodiment, the booster consists of a linear, water-soluble polymer which carries a hydrophobic, water-insoluble group at one end of the chain. The hydrophobic, water-insoluble group preferably has a molecular weight of 110 to 500 g / mol and particularly preferably a molecular weight of 110 to 280 g / mol. The molecular weight ratio of the water-soluble unit to the hydrophobic water-insoluble groups is preferably 7 to 50.

In a particularly preferred embodiment, the booster consists of an alcohol ethoxylate of a C ₈ -C ₂₀ -alcohol having 25 to 500 ethoxy groups, preferably 50 to 200 ethoxy groups.

In a further preferred embodiment, the booster is present in an amount of 3 to 20% by weight, preferably 5 to 15% by weight, in particular 7 to 15% by weight, in each case based on the total weight of components c), d) and e), before.

In a preferred embodiment, the aqueous microemulsions according to the invention have the components c) + d) + e) in an amount of 2 to 20% by weight, preferably 3 to 15% by weight, more preferably 3 to 10% by weight and in particular 3 to 8 wt .-% or 4 to 8 wt .-%, each based on the total weight of the microemulsion on.

The microemulsions according to the invention can be used as cleaning agents in the private as well as in the commercial sector. It is particularly advantageous that the aqueous microemulsions can be used as neutral cleaners and thus replace the known in the prior art aggressive alkaline cleaner for the removal of oily soils, such as paint residues. In one embodiment, the microemulsions according to the invention have a pH of from 4 to 11, preferably from 5 to 9.

The microemulsions according to the invention may additionally have further additives. Suitable additives are, for example, mono-, di- or triethylene glycol monoalkyl ethers or aryl ethers, such as ethylene glycol propyl ether, ethylene glycol butyl ether (butyl glycol), ethylene glycol hexyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether (butyl diglycol), diethylene glycol hexyl ether, triethylene glycol methyl ether, Triethylene glycol ethyl ether, triethylene glycol butyl ether, ethylene glycol phenyl ether;

Mono-di- or tripropylene glycol monoalkyl ethers or aryl ethers such as propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol n-propyl ether, propylene glycol butyl ether, dipropylene glycol methyl ether, dipropylene glycol n-propyl ether, dipropylene glycol butyl ether, tripropylene glycol methyl ether, tripropylene glycol butyl ether, propylene glycol phenyl ether.

Mono-di- or triethylene glycol dialkyl ethers, mono- di- or tripropylene glycol dialkyl ethers such as dipropylene glycol dimethyl ether

N-alkylpyrrolidones having a C ₁ -C ₁₂ -alkyl radical, for example N-ethylpyrrolidone, N-octylpyrrolidone, N-dodecylpyrrolidone.

In addition, biocides and / or dyes as well as antirust and Antioxdanzmittel can be added.

The additives may be present in amounts of 0.01 to 3, preferably 0.1 to 1 wt .-%, based on the total weight of the microemulsion.

The microemulsions of the invention may be in the form of oil-in-water or water-in-oil microemulsions. Preferably, they are present as a bicontinuous microemulsion. Bicontinuous microemulsions comprise two domains, a hydrophobic and a hydrophilic domain in the form of extended juxtaposed and intertwined domains, at the interface of which stabilizing surface active surfactants are enriched in a monomolecular layer. Microemulsions form very easily because of the very low interfacial tension spontaneously when the individual components water, oil and a suitable surfactant system are mixed. Since the domains in at least one dimension only very small extent on the order of nanometers, microemulsions often appear visually transparent and are thermodynamic, ie unlimited in time, stable depending on the surfactant system used in a certain temperature range. If microemulsions have low surfactant contents, they may also be cloudy and yet thermodynamically stable.

The microemulsion is particularly stable in the temperature range of 10 to 40 ° C, in particular 5 to 60 ° C.

In a further embodiment, the microemulsions according to the invention are stable in a temperature range <5 ° C to> 60 ° C.

In one embodiment, the microemulsion of the present invention may be a water-in-oil or oil-in-water droplet microemulsion wherein water droplets from the oil or oil droplets are enclosed by the water.

Particularly preferred are bicontinuous microemulsions.

Typically, the weight fraction of ester oil (component a)) in the ester oil-water mixture is from 12 to 45% by weight, preferably from 23 to 38% by weight, based on the total weight of ester oil and water in the microemulsion.

Another object of the present invention is a cleaner, consisting or comprising the microemulsion according to the invention.

Another object of the present invention is the use of the microemulsion according to the invention as a cleaning agent, in particular for removing oily soiling or resins and polymer-like soils.

In one embodiment of the cleaner according to the invention, the proportion of components c) and d) is less than 15 wt .-%, in particular less than 12 wt .-% or less than 9 wt .-% or less than 7 wt .-%, for example 2.5 to 7 wt .-%, each based on the total weight of the cleaning agent. Depending on the field of application, this very low surfactant content makes it possible to produce products which are not subject to any labeling requirement with respect to their surfactant content.

The cleaner according to the invention is particularly suitable as a replacement of organic solvents. This results in a reduction of the amount of organic solvent used up to the abandonment of aromatic solvents result, which is advantageous in terms of occupational safety and environmental protection. In addition, both cleaners according to the invention have the microemulsions according to the invention therein increased flash points compared to the organic phases contained therein.

Furthermore, the use of the cleaner according to the invention for cleaning colors, especially dried or dry paints, varnishes and tarry compounds and adhesives, as a general purpose cleaner and neutral detergent in the household, in the industry and the commercial sector is possible.

A use of the cleaner according to the invention is also recommended when cleaning paints and varnishes on an aqueous and organic basis, in particular for cleaning brushes.

The cleaner according to the invention can also be used for cleaning paints, varnishes, oil and / or salt-like residues of metal and / or plastic surfaces.

A use is recommended for sensitive surfaces, especially those that are attacked by organic solvents or acidic or alkaline cleaners, such as aluminum surfaces. The cleaner according to the invention could thus replace, for example, organic cleaning agents in many areas of application.

In addition, the microemulsions according to the invention can also be used for cleaning in the printing industry, in particular for removing printing inks and paper dust build-up of printing presses and printing plates. It is suitable, for example, for removing water-based or oil-based printing inks and radiation-curing printing ink. Furthermore, the cleaner finds application in the cleaning of printing cylinders, pressure rollers and surfaces of printing machines, preferably for cleaning printing machines for conventional printing and printing forms, for example, when interrupting the printing process or non-impact printing process. Conventional printing processes in which the cleaner can be used include planographic printing, gravure printing, high-pressure printing, flexographic printing and screen printing, in particular offset and waterless offset printing. The non-impact printing methods without printing form include electrophotography, ionography, magnetography, inkjet and thermography.

In a further embodiment of the present invention, the microemulsion according to the invention is used for cleaning and / or removing compounds selected from the group consisting of paints, lacquers, greases, oils, resins, bitumen, tar, adhesive residues, sealants, rubber abrasion, cosmetic and make-up remnants and pyrolysis products of organic compounds, in particular for the purification and / or removal of contaminants whose organic constituents are polymer-based, for example, paints, adhesives, sealants, polymer foams, such as polyurethane foams.

The microemulsion according to the invention is particularly suitable for the cleaning and / or removal of dried inks and adhesives.

In a particularly preferred embodiment, the microemulsions according to the invention are used for the purification of dye residue contaminated tools, in particular tools for applying paints, such as brushes, paint rollers or paint sprayers.

It has been found that the microemulsions according to the invention show excellent cleaning performance, in particular in the case of polymer-based soiling.

Surprisingly, it has also been found that the microemulsions according to the invention are suitable for removing organic pyrolysis products. In a particularly preferred embodiment, the microemulsions according to the invention are used for cleaning ovens, chimney panes or a grill.

1. a) Applizieren einer erfindungsgemäßen Mikroemulsion auf eine verunreinigte Oberfläche,
2. b) gegebenenfalls Einwirkenlassen der Mikroemulsion, und
3. c) Entfernen der Verunreinigung.

A further subject of the present invention comprises a method for purification, comprising the following steps:

1. a) applying a microemulsion according to the invention to a contaminated surface,
2. b) optionally exposing the microemulsion, and
3. c) removing the contaminant.

It has been found that, in particular when removing polymer-based impurities, an exposure time of preferably 1 minute to 2 days, more preferably 5 minutes to 1 hour, for example 10 to 30 minutes, greatly facilitates the detachment of the polymer-based impurity.

Long exposure times are easily possible with the microemulsions according to the invention, since the vapor pressure is low in relation to conventional solvent-based cleaners.

Examples Used components:

The drinking water used has the following characteristics: pH = 8.0, sodium 14 mg / l potassium 2.7 mg / l, calcium 60 mg / l, magnesium 14 mg / l, nitrate 34.9 mg / l, chloride 46.1 mg / l.

Rape methyl ester (RME) is an ester oil from Overlack.

Octyloctanoate (octanoic acid octyl ester) is an ester oil from Sigma Aldrich.

Oleic acid ethyl ester from Sigma Aldrich.

Methyl laurate from Sigma Aldrich.

Di Basic Ester: Mixture of dimethyl succinate (33% by weight), dimethyl adipate (33% by weight), dimethyl glutarate (33% by weight) and methanol (0.2% by weight) from Caldic.

Isopropyl myristate from Sigma Aldrich.

Triumphnetzer ZSG (AOT, sulfosuccinic acid 1,4-bis (2-ethylhexyl) ester, sodium salt is an anionic surfactant from Zschimmer and Schwarz, active ingredient content 69%).

Tween 21 is a polyoxyethylene (4) sorbitan monolaurate from Sigma Aldrich, drug content 100%.

Tween 40 is a polyoxyethylene (20) sorbitan monopalmitate from Sigma Aldrich, drug content 100%.

Tween 80 is a polyoxyethylene (20) sorbitan monooleate from Sigma Aldrich, drug content 100%.

Emulan EL is an ethoxylated castor oil from BASF, active ingredient content 100%; HLB: 14.

Brij S100-PA- (SG) is a PEG-100 stearyl ether from Croda, drug content 100%.

Novel TDA-40 is a PEG-40 isotridecyl ether from Sasol, drug content 100%.

Novel 2426-100 is a PEG C _20-28 alkyl ether from Sasol with about 100 EO units, active ingredient content 100%; HLB: 18.3.

Emuldac AS-80 is a PEG 80 C _16-18 alkyl ether from Sasol, active ingredient content 100%.

Potassium sodium tartrate 4 hydrate, trisodium citrate 2 hydrate, disodium hydrogen phosphate 2 hydrate, sodium gluconate (free of water of crystallization), calcium chloride (free of water of crystallization), sodium chloride (free of water of crystallization).

Akachemie Solupast D Löser (0203) from PUFAS Werk KG: Mixture of N-butyl acetate (50-100%), heavy petroleum distillates, treated with hydrogen (10-25%) and ethoxylated C ₁₃ -oxoalcohol (≤ 2.5%) ,

Brush cleaner from PUFAS Werk KG: mixture of white spirit (50-100%), ethoxylated C ₁₃ -oxoalcohol (2.5-10%), solvent naphtha light (2.5-10%), 1,2,4-trimethylbenzene (2.5-10%) and dipropylene glycol monomethyl ether (2.5-10%).

Praktiker Buntlack red based on alkyd resin from the company Faust.

Praktiker 2 in 1 varnish red acrylic on the basis of the company Faust.

Acrylic sealant from the company Faust.

Construction silicone of the company Faust.

Pattex gel from Henkel.

Brush of the company Wistoba No. 1000 02, light bristles, width 14 mm, length 33 mm.

Stainless steel plates (material number 1.4571).

The temperature stability of the microemulsions was determined in a thermostated vessel by visual inspection. The temperature phase boundaries of the single-phase microemulsion region were recognized due to the drastically increasing turbidity when the stability window was exceeded or not reached. Lamellar phases were determined by crossed polarizers. In the ranges of stability given for the examples, microemulsions can coexist with lamellar phases.

The total surfactant contents relate to the active substance proportions of the surfactant components and of the booster. All percentages are based on the weight of the ingredients.

example 1

• Triumphnetzer: 10.72%
• Tween 21: 4.21%
• Octyloctanoate: 21.52%
• Water: 61.53%
• Potassium sodium tartrate 4 hydrate: 0.73%
• Brij S100-PA (SG): 1.29%
• Stability range of the microemulsion is between 5C ° and 34 ° C, total surfactant content 12.9%.

Example 2

• Triumphnetzer: 7.24%
• Tween 21: 6.45%
• Octyloctanoate: 21.24%
• Water: 62.00%
• Potassium sodium tartrate 4 hydrate: 1.77%
• Brij S100-PA (SG): 1.30%
• Stability range of the microemulsion is between <0 ° C and 45 ° C, total surfactant content 12.7%.

Example 3

• Triumphnetzer: 8,22%
• Tween 21: 5.99%
• Octyloctanoate: 21.22%
• Water: 61.87%
• Disodium hydrogen phosphate 2 hydrate: 1.40%
• Brij S100-PA (SG): 1.30%
• Stability range of the microemulsion is between <0 ° C and 44 ° C, total surfactant content 13.0%.

Example 4

• Triumphnetzer: 10.70%
• Tween 21: 4.05%
• Octyloctanoate: 21.38%
• Water: 61.18%
• Sodium gluconate: 1.41%
• Brij S100-PA (SG): 1.28%
• Stability range of the microemulsion is between 5 ° C and 38 ° C, total surfactant content 12.7%.

Example 5

• Triumphnetzer: 6,91%
• Tween 40: 5.89%
• Oleic acid ethyl ester: 26.14%
• Water: 58.93%
• CaCl ₂ : 0.94%
• Brij S100-PA (SG): 1.19%
• Stability range of the microemulsion is between <0 ° C and 48 ° C, total surfactant content 11.9%.

Example 6

• Triumphnetzer: 12.52%
• Tween 21: 4.73%
• Octyloctanoate: 24.99%
• Water: 55.58%
• Trisodium citrate 2 hydrate: 0.71%
• Brij S100-PA (SG): 1.47%
• Stability range of the microemulsion is between <0 ° C and 45 ° C, total surfactant content 14.8%.

Example 7

• Triumphnetzer: 8,96%
• Tween 21: 5.29%
• Octyloctanoate: 33.95%
• Water: 49.33%
• Trisodium citrate 2 hydrate: 1.17%
• Brij S100-PA (SG): 1.30%
• Stability range of the microemulsion is between <0 ° C and 43 ° C, total surfactant content 12.8%.

Example 8

• Triumphnetzer: 7,38%
• Tween 21: 2.21%
• Octyloctanoate: 22.24%
• Water: 65.33%
• Trisodium citrate 2 hydrate: 1.50%
• Novel 24 / 26-100: 1.34%
• Stability range of the microemulsion is between 5C ° and 30 ° C, total surfactant content 8.7%.

Example 9

• Triumphnetzer: 10.66%
• Tween 21: 3.44%
• Octyloctanoate: 21.19%
• Water: 61.34%
• Trisodium citrate 2 hydrate: 1.44%
• Emuldac AS-80: 1.93%
• Stability range of the microemulsion is between 5C ° and 35 ° C, total surfactant content 12.7%.

Example 10

• Triumphnetzer: 8,52%
• Tween 21: 6.27%
• Octyloctanoate: 21.14%
• Water: 61.99%
• Trisodium citrate 2 hydrate: 1.44%
• Novel TDA-40: 0.64%
• Stability range of the microemulsion is between <0 ° C and 45 ° C, total surfactant content 12.8%.

Example 11 Triumphnetzer: 11.56%

• Tween 40: 3.47%
• Oleic acid ethyl ester: 21.29%
• Water: 61.07%
• Trisodium citrate 2 hydrate: 1.32%
• Brij S100-PA (SG): 1.29%
• Stability range of the microemulsion is between 6C ° and 47 ° C, total surfactant content 12.7%.

Example 12

• Triumphnetzer: 8.35%
• Tween 40: 3.11%
• Methyl laurate: 26.41%
• Water: 60.26%
• Trisodium citrate 2 hydrate: 0.88%
• Brij S100-PA (SG): 0.99%
• Stability range of the microemulsion is between <0 ° C and 53 ° C, total surfactant content 9.9%.

Example 13

• Triumphnetzer: 6,56%
• Emulan EL: 1.61%
• RME: 27.76%
• Water: 62.87%
• NaCl: 0.47%
• Brij S100-PA (SG): 0.73%
• Stability range of the microemulsion is below 10 and 30 ° C, total surfactant content 6.9%.

Example 14

• Triumphnetzer: 7.44%
• Tween 21: 5,50%
• Octyloctanoate: 12.88%
• Di Basic Ester: 8.74%
• Water: 62.81%
• Trisodium citrate 2 hydrate: 1.46%
• Brij S100-PA (SG): 1.17%
• Stability range of the microemulsion is between <0 ° C and> 60 ° C, total surfactant content 11.8%.

Example 15

• Triumphnetzer: 8.35%
• Tween 21: 5.79%
• Octyloctanoate: 21.20%
• Water: 61.94%
• Trisodium citrate 2 hydrate: 1.43%
• Brij S100-PA (SG): 1.29%
• Stability range of the microemulsion is between <0 ° C and 44 ° C, total surfactant content 12.8%.

Example 16

• Triumphnetzer: 8.39%
• Tween 40: 6.04%
• Methyl laurate: 29.83%
• Water: 53.32%
• Trisodium citrate 2 hydrate: 1.15%
• Brij S100-PA (SG): 1.27%
• Stability range of the microemulsion is between <0 ° C and above 60 ° C, total surfactant content 13.1%.

Example 17

• Triumphnetzer: 6,94%
• Tween 80: 6.00%
• Oleic acid ethyl ester: 26.07%
• Water: 58.87%
• CaCl ₂ : 0.95%
• Brij S100-PA (SG): 1.17%
• Stability range of the microemulsion is between <0 ° C and 48 ° C, total surfactant content 12.0%.

Example 18

• Triumphnetzer: 5.24%
• Tween 21: 4.74%
• Octyloctanoate: 26.70%
• Water: 61.41%
• Trisodium citrate 2 hydrate: 1.29%
• Brij S100-PA (SG): 0.62%
• Stability range of the microemulsion is between <0 ° C and 33 ° C, total surfactant content 9.0%.

Example 19

• Triumphnetzer: 11.51%
• Tween 21: 3.61%
• Octyloctanoate: 21.35%
• Water: 61.17%
• Potassium sodium tartrate 4 hydrate: 1.05%
• Brij S100-PA (SG): 1.31%
• Stability range of the microemulsion is between 12C ° and 50 ° C, total surfactant content 12.9%.

Example 20

• Triumphnetzer: 8,92%
• Tween 21: 4,40%
• Isopropyl myristate: 25.78%
• Water: 58.35%
• Trisodium citrate 2 hydrate: 1.37%
• Brij S100-PA (SG): 1.18%
• Stability range of the microemulsion is between 16.5 ° C and 50 ° C, total surfactant content 11.7%.

Cleaning examples:

Cleaning tests were carried out with oil-soluble paint (Praktiker alkyd resin-based paint) and water-soluble paint (Praktiker 2 in 1 acrylic-based paint), with both fresh and dried paint tests.

Cleaning fresh oil-soluble paint from brushes

On the brush to be cleaned was applied 1.2g Praktiker Buntlack alkyd resin-based and then in each 100ml cleaner several times on the beaker bottom and rinsed under running water. The cleaners used were the microemulsion mixtures 1, 12, 14 and, as a comparative example, the brush cleaners from Pufas. In all cases, the paint was essentially removed from the brush.

Cleaning of dried oil-soluble paint from paintbrushes

On the brush to be cleaned was applied 1.2g Praktiker Buntlack based on alkyd resin and dried for 24 hours. Then the brushes were soaked in 100 ml of detergent in a beaker for 48 hours. Thereafter, the brushes were pressed several times on the beaker bottom and rinsed under running water. The cleaners were the microemulsion mixtures 12 and 14 used. After expressing and washing with water, in all cases the dried paint was substantially removed.

Cleaning of dried water-soluble paint from brushes

1.5 g of Praktiker 2 in 1 acrylic-based varnish was applied to the brush to be cleaned and dried for 24 hours. Then the brushes were soaked in 100 ml of detergent in a beaker for 48 hours. Thereafter, the brushes were pressed several times on the beaker bottom and rinsed under running water. Was used as a cleaner, the microemulsion mixtures 1, 12 and 14, the paint residues dissolved as solid particles from the brush hairs and could be removed by rubbing and rinsing with water substantially from the brushes. The brush cleaner from Pufas could not remove the dried-on paint.

In addition, the cleaners were tested for the ability to clean other materials. These tests were performed with acrylic sealant, building silicone and adhesive on stainless steel plates.

Cleaning of solid acrylic sealant

0.25 g of the acrylic sealant were applied to the area of approximately 40 × 40 mm of the acrylic plates cleaned with acetone (material number 1.4571) and dried in the air for 24 hours. Then 0.5 g each of the microemulsion mixtures 1, 12 and 14, as well as the solubilizer Solupast from Pufas was applied to the sealant. After two hours of exposure time, the sealant could in all cases be scraped off with the help of a spatula with slight mechanical force. After 24 hours of exposure time, the state when using the microemulsion mixtures was unchanged, in the case of the solubilizer Solupast the sealant stuck firmly on the steel surface.

Cleaning solid silicone sealant

Each 0.40 g of silicone sealant was applied to the acetone-cleaned stainless steel plates in an area of about 40 × 40 mm and air-dried for 24 hours. Thereafter, in each case 0.5 g of the microemulsion mixtures 1, 12 and 14, and the solver Solupast the company Pufas applied to the silicone. After two hours exposure, in all cases, the sealant with a slight mechanical force could be lifted with the help of a spatula. After 24 hours of exposure time, the state was unchanged when using the microemulsion mixtures, in the case of the solubilizer Solupast the silicone compound again stuck firmly on the steel surface.

Cleaning of dried glue

0.55 g of the Pattex gel was applied to the acetone-cleaned stainless steel plates over an area of about 40 × 40 mm and dried in air for 24 hours. Thereafter, 0.5 g each of the microemulsion mixtures 1, 12 and 14, and the solubilizer Solupast from Pufas were applied to the adhesive. After two hours exposure, the adhesive could be scraped off with light mechanical force with the help of a spatula. After 24 hours of exposure time, the state was unchanged when using the microemulsion mixtures, in the case of the solubilizer Solupast the adhesive again stuck firmly on the steel surface.

Comparative Examples Comparative Experiments: Substitution of Hydrocarbon Oils by Ester Oils in Examples from WO 2008/132202

Examples 2 and 5 in WO 2008/132202 (P 24, 25) were used for comparative experiments. In both cases, the oil component (Hydroseal G232H in Example 2 and Ketrul D85 in Ex. 5) was replaced by the carboxylic acid ester rapeseed methyl ester (RME). In addition, the mass ratio of the two surfactant components (Span 20 and AG 6210 in Example 2 and Imwitor 928 and AG 6210 in Example 5) was varied around the values given in the examples. This was intended to capture the optimum temperature stability range for the microemulsions.

Comparative Examples to Example 2 of WO 2008/132202

Example 2 from WO 2008/132202 has the following composition (all figures in% by weight): water 46.45 Hydroseal G 232 H 42.38 AG 6210 5.39 Span 20 4.88 Brij 700 0.90

The mixture can be characterized from the surfactant side as follows.

The surfactant components are AG 6210 (active content 60% by weight, the remainder is water), Span 20 (active content 100% by weight) and Brij 700 (active content 100% by weight). All other details relate to the active contents of the surfactants. The total surfactant content in the above example is 9.0%.
The mass fraction AG 6210 in a mixture with Span 20 (delta) is 39.9%. $$\mathrm{delta}=\frac{\mathrm{m}\left(\mathrm{Active\; salary\; AG}\mathrm{6210}\right)}{\mathrm{m}\left(\mathrm{Active\; salary\; AG}\mathrm{6210}\right)+\mathrm{m}\left(\mathrm{chip}20\right)}$$

The mass fraction of polymeric booster (Brij 700) in the total surfactant mixture is 10.0%. $$\mathrm{Mass\; fraction\; booster}=\frac{\mathrm{m}\left(\mathrm{Brij}\mathrm{700}\right)}{\mathrm{m}\left(\mathrm{Active\; salary\; AG}\mathrm{6210}\right)+\mathrm{m}\left(\mathrm{chip}\mathrm{20}\right)+\mathrm{m}\left(\mathrm{Brij}700\right)}$$

The stability range of the microemulsion phase is 0 to 52 ° C.

Will turn off in Example 2 WO 2008/132202 Replacing the Hydroseal G 232 H oil component with RME does not produce a microemulsion phase. The surfactant mixture is not efficient enough to emulsify all water and oil as a microemulsion.

Therefore, the total surfactant content in Comparative Examples was increased to about 30%. Delta was off by the value in Example 2 WO 2008/132202 varies around; the mass fraction of boosters and the mass ratio of water to oil were kept constant on the values of Example 2 WO 2008/132202 ,

Table 1 below shows the stability ranges of the microemulsions as a function of the total surfactant content and of delta. The compositions of the individual mixtures (Comparative Examples 1 to 15) are listed in Table 3.

The temperature behavior of the mixtures was measured up to 75 ° C. Higher temperatures are not relevant for most applications. Table 1: Delta in% 24.9 29.6 35.1 39.2 45.3 50.1 Total surfactant% 30.1 29.9 29.9 29.5 29.4 Microemulsion stability range ≥63 ° C ≥59 ° C ≥52 ° C (Comp. Ex. 1) (Comp. Ex. 2) (Comp. Ex. 3) (Comp. Ex. 4) (Comp. Ex. 5) Total surfactant% 25.3 25.2 25.1 25.0 25.0 Microemulsion stability range ≥64 ° C ≥57 ° C (Comp. Ex. 6) (Comp. Ex. 7) (Comp. Ex. 8) (Comp. Ex. 9) (Comp. Ex. 10) Total surfactant% 20.0 20.1 Microemulsion stability range ≥63 ° C (Comp. Ex. 11) (Comp. Ex. 12) Total surfactant% 16.6 16.0 Microemulsion stability range ≥69 ° C - (Cf. Ex. 13) (Comp. Ex. 14) Total surfactant% 15.0 Microemulsion stability range - (See - Ex. 15)

Comparative Examples 1 to 15 show that when the hydrocarbon oil is replaced by ester oil, microemulsion phases develop only at total surfactant concentrations above 16%. Apart from the fairly high temperatures at which the microemulsion phases occur, the temperature windows are also quite narrow.

Comparative Examples to Example 5 of WO 2008/132202

Example 5 from WO 2008/132202 has the following composition (all figures in% by weight): water 43.84 Ketrul D85 48.41 AG 6210 3.94 Imwitor 928 3.22 C12E190 0.59

The mixture can be characterized from the surfactant side as follows.

The surfactant components are AG 6210 (active content 60% by weight, the remainder is water), Imwitor 928 (active content 100% by weight) and C12E190 (active content 100% by weight). All other details relate to the active contents of the surfactants.

The total surfactant content in the above example is 6.2%.

The mass fraction AG 6210 in a mixture with Imwitor 928 (delta) is 42.3%. $$\mathrm{delta}=\frac{\mathrm{m}\left(\mathrm{Active\; salary\; AG}\mathrm{6210}\right)}{\mathrm{m}\left(\mathrm{Active\; salary\; AG}\mathrm{6210}\right)+\mathrm{m}\left(\mathrm{Imwitor}928\right)}$$

The mass fraction of polymeric boosters (C12E190) in the total surfactant mixture is 9.6%. $$\mathrm{Mass\; fraction\; booster}=\frac{\mathrm{m}\left(\mathrm{C}\mathrm{12}\mathrm{e}\mathrm{190}\right)}{\mathrm{m}\left(\mathrm{Active\; salary\; AG}\mathrm{6210}\right)+\mathrm{m}\left(\mathrm{Imwitor}\mathrm{928}\right)+\mathrm{m}\left(\mathrm{C}\mathrm{12}\mathrm{e}\mathrm{190}\right)}$$

The stability range of the microemulsion phase is 15 to 75 ° C.

Turns off in Example 5 WO 2008/132202 The oil component Ketrul D85 replaced by RME, can not produce a microemulsion phase. The surfactant mixture is not efficient enough to emulsify all water and oil as a microemulsion. Therefore, the total surfactant content in Comparative Examples was increased to about 28%. Delta was off by the value in Example 5 WO 2008/132202 varies around; the mass fraction of boosters and the mass ratio of water to oil were kept constant on the values of Example 5 WO 2008/132202 , As booster was used in Comparative Examples 16 to 38 Brij 700, which behaves surfactant same as C12E190.

Table 2 below shows the stability ranges of the microemulsions as a function of the total surfactant content and of delta. The compositions of the individual mixtures (Comparative Examples 16 to 38) are listed in Tables 4a-e.

The temperature behavior of the mixtures was measured up to 75 ° C. Higher temperatures are not relevant for most applications. Table 2: Delta in% 23.0 27.8 32.1 36.9 39.6 41.9 46.0 Total surfactant% 28.5 28.5 28.6 28.4 28.4 Microemulsion stability range 72-74 ° C ≥66 ° C ≥62 ° C ≥59 ° C 56-74 ° C - (Comp. Ex. 16) (Cf. Ex. 17) (Comp. Ex. 18) (Comp. Ex. 19) (Comp. Ex. 20) (Comp. Ex. 21) Total surfactant% 22.7 22.4 22.6 22.5 22.6 Microemulsion stability range 67-72 ° C ≥67 ° C ≥63 ° C - - (Comp. Ex. 22) (Cf. Ex. 23) (Comp. Ex. 24) (Comp. Ex. 25) (Comp. Ex. 26) Total surfactant% 20.0 20.0 20.0 20.0 20.0 Microemulsion stability range 69-74 ° C ≥66 ° C - - - (Comp. Ex. 27) (Comp. Ex. 28) (Comp. Ex. 29) (Comp Bsp.30) (Comp. Ex. 31) Total surfactant% 18.1 18.0 Microemulsion stability range ≥69 ° C 66-74 ° C (Comp. Ex. 32) (Comp. Ex. 33) Total surfactant% 14.9 15.0 15.0 Microemulsion stability range ≥74 ° C ≥69 ° C - (Comp. Ex. 34) (Comp. Ex. 35) (Comp. Ex. 36) Total surfactant% 13.0 13.1 Microemulsion stability range - - (Comp. Ex. 37) (Comp. Ex. 38)

Comparative Examples 16 to 38 show that when the hydrocarbon oil is replaced by ester oil, microemulsion phases only form at total surfactant concentrations of about 15%. Apart from the fairly high temperatures at which the microemulsion phases occur, the temperature windows are also quite narrow.

Conclusion

The replacement of the hydrocarbon oil by ester oil in Examples 2 and 5 of WO 2008/132202 leads to microemulsion systems with quite narrow temperature stability windows. In addition, relatively high total surfactant concentrations are needed. In contrast, the surfactant mixtures according to the invention for ester oils allow significantly lower total surfactant concentrations and also other temperature windows, which are also in a better temperature range for cleaning applications (see Examples 1-20).

Composition of microemulsion mixtures in% by mass

For AG 6210, the information refers to the 60% aqueous solution. For all other substances, the active content is 100%.

The mass ratio of water to RME was kept constant for reasons of systematics for the comparative examples 1 to 15 (Tables 3a-c) and 16 to 38 (Tables 4a-e). The water content is composed of the water specified in the tables and the water content of AG 6210. Smaller deviations between the examples are of negligible importance for the phase behavior of the mixtures.

Comparative Examples to Example 2 of WO 2008/132202

Table 3a: Comp. 1 Comp. 2 Comp. 3 Comp. 4 Comp. 5 water 31.94 31.54 30.41 30.12 29,69 RME 32.61 32.64 32,70 32.35 32.12 AG 6210 13.39 15.58 17.58 20,06 22.09 Span 20 19.10 17.29 16.36 14.55 13,20 Brij 700 2.96 2.95 2.95 2.92 2.90 Table 3b: Comp. 6 Comp. 7 Comp. 8th Comp. 9 Comp. 10 water 35,11 34.77 33,60 32,95 32.19 RME 35.13 35.07 35.36 35.25 35.26 AG 6210 11.24 13.12 14.79 17.00 18.83 Span 20 16.04 14.56 13.77 12.33 11.25 Brij 700 2.48 2.48 2.48 2.47 2.47 Table 3c: Comp. 11 Comp. 12 Comp. 13 Comp. 14 Comp. 15 water 38.72 38.45 43,40 41.17 44.34 RME 37.64 37.48 37.52 39.97 38.44 AG 6210 8.93 10.47 6.15 7.12 5.55 Span 20 12.74 11.62 11.13 10.17 10.05 Brij 700 1.97 1.98 1.80 1.57 1.62

Comparative Examples to Example 5 of WO 2008/132202

Table 4a: Comp. 16 Comp. 17 Comp. 18 Comp. 19 Comp. 20 water 29.94 29.08 28:19 28.06 27.63 RME 36.75 36.84 36.85 36.74 36.77 AG 6210 11,95 13.88 15.96 16.96 17,98 Imwitor 928 18.63 17.49 16.28 15.51 14,92 Brij 700 2.73 2.71 2.74 2.73 2.70 Table 4b: Comp. 21 Comp. 22 Comp. 23 Comp. 24 Comp. 25 water 27.29 34.03 33.37 32.69 32.75 RME 36.47 39.49 39.91 39.64 39.36 AG 6210 19.72 9.50 10.82 12.60 13.42 Imwitor 928 13.87 14.81 13.72 12.92 12.26 Brij 700 2.65 2.17 2.18 2.15 2.21 Table 4c: Comp. 26 Comp. 27 Comp. 28 Comp. 29 Comp. 30 water 31.66 35.67 34.91 34.48 34.32 RME 39.94 40,95 41.28 41,05 40.91 AG 6210 14.33 8.39 9.64 11.14 11.92 Imwitor 928 11.91 13.08 12.23 11.43 10.89 Brij 700 2.16 1.91 1.94 1.90 1.96 Table 4d: Comp. 31 Comp. 32 Comp. 33 Comp. 34 Comp. 35 water 33.67 36.91 36.29 39.62 38.89 RME 41.27 41.98 42.22 43.43 43.61 AG 6210 12.64 7.57 8.70 5.17 6.28 Imwitor 928 10.51 11.81 11.04 10.36 9.79 Brij 700 1.91 1.73 1.75 1.42 1.43 Table 4e: Comp. 36 Comp. 37 Comp . Ex . 38 water 38,30 40.78 40.13 RME 43,80 44.42 44,60 AG 6210 7.25 4.51 5.48 Imwitor 928 9.19 9.05 8.54 Brij 700 1.46 1.24 1.25

Claims (16)

1. An aqueous microemulsion, comprising:

   a) one or more liquid carboxylic acid ester(s) to form an oil component;

   b) one or more water-soluble salt(s) with one or more cation(s), preferably selected from the group consisting of sodium, potassium, calcium, magnesium and ammonium;

   c) one or more salt(s) of sulfosuccinate esters;

   d) one or more non-ionic surfactant(s) selected from alkoxylated sorbitan ester and alkoxylated vegetable oil; and

   e) one or more booster(s) in the form of a hydrophilic polymeric additive consisting of a water-soluble moiety having a hydrophobic, water-insoluble group with a molecular weight of from 80 to 500 g/mol on at least one chain terminal, and the molar mass ratio of the water-soluble moiety to the hydrophobic, water-insoluble groups is from 7 to 200; or
   said booster is an alcohol ethoxylate of a C₈-C₂₀ alcohol with from 25 to 500 ethoxy groups.
2. The aqueous microemulsion according to claim 1, characterized in that said liquid carboxylic acid ester has from 6 to 22, preferably from 10 to 22, carbon atoms.
3. The aqueous microemulsion according to claim 1 or 2, characterized in that said liquid carboxylic acid ester is selected from the group consisting of esters of a monohydric alcohol and a mono- or dicarboxylic acid, and esters of a dihydric alcohol and a monocarboxylic acid, more preferably esters of monohydric alcohols with monocarboxylic acids, in particular, said liquid carboxylic acid ester is an ester derived from a C₁₀-C₂₂ monocarboxylic acid and methanol, preferably dodecanoic acid methyl ester or rapeseed oil methyl ester.
4. The aqueous microemulsion according to one or more of the preceding claims, characterized in that said liquid carboxylic acid ester is contained in an amount of from 10 to 40% by weight, preferably from 20 to 35% by weight, respectively based on the total weight of the microemulsion.
5. The aqueous microemulsion according to one or more of the preceding claims, characterized in that the weight ratio of the liquid carboxylic acid ester (component a)) to the sum of components c), d) and e) is from 1.5 to 10, preferably from 2.5 to 8, especially from 3 to 8, or from 4 to 8.
6. The aqueous microemulsion according to one or more of the preceding claims, characterized in that said salt of sulfosuccinate esters is selected from the group consisting of diesters of sulfosuccinic acid alkali salt with C₆-C₁₀ alcohols, monoesters of sulfosuccinic acid dialkali salt with C₈-C₁₂ alcohols, and monoesters of sulfosuccinic acid dialkali salt with ethoxylated C₁₀-C₁₄ alcohols, in particular, said salt of sulfosuccinate esters is the sodium salt of bis(2-ethylhexyl) sulfosuccinate.
7. The aqueous microemulsion according to one or more of the preceding claims, characterized in that said salt of sulfosuccinate esters is contained in an amount of from 1 to 10% by weight, preferably in an amount of from 2 to 5% by weight, respectively based on the total weight of the microemulsion.
8. The aqueous microemulsion according to one or more of the preceding claims, characterized in that said salt of sulfosuccinate esters is contained in an amount of from 30 to 75% by weight, preferably in an amount of from 40 to 70% by weight, respectively based on the total weight of components c), d) and e).
9. The aqueous microemulsion according to one or more of the preceding claims, characterized in that said non-ionic surfactant is selected from ethoxylated sorbitan ester and/or ethoxylated vegetable oil, preferably said non-ionic surfactant is an ethoxylated sorbitan monoester with a saturated or unsaturated C₁₂-C₁₈ fatty acid radical, or ethoxylated castor oil; in particular, said non-ionic surfactant is an ethoxylated sorbitan ester and/or ethoxylated vegetable oil having an HLB value of from 11 to 17, preferably from 12 to 16, or from 13 to 16.
10. The aqueous microemulsion according to one or more of the preceding claims, characterized in that said booster is an alcohol ethoxylate of a C₈-C₂₀ alcohol with from 50 to 200 ethoxy groups.
11. The aqueous microemulsion according to one or more of the preceding claims, characterized in that said booster is contained in an amount of from 3 to 20% by weight, preferably from 5 to 15% by weight, especially from 7 to 15% by weight, respectively based on the total weight of components c), d) and e).
12. The aqueous microemulsion according to one or more of the preceding claims, characterized in that said salt is selected from the group consisting of sodium sulfate, sodium chloride, sodium gluconate, sodium citrate, trisodium phosphate, disodium hydrogenphosphate, potassium sulfate, potassium chloride, ammonium sulfate, ammonium chloride, magnesium sulfate, magnesium chloride, calcium chloride, calcium acetate, and magnesium acetate, preferably said salt is an acetate, especially calcium acetate and/or magnesium acetate.
13. The aqueous microemulsion according to one or more of the preceding claims, characterized in that the sum of components c), d) and e) is contained in an amount of from 2 to 20% by weight, preferably from 3 to 15% by weight, more preferably from 3 to 10% by weight, especially from 3 to 8% by weight, or from 4 to 8% by weight, respectively based on the total weight of the microemulsion.
14. The aqueous microemulsion according to one or more of the preceding claims, characterized in that said microemulsion is in the form of a bicontinuous microemulsion.
15. Use of the microemulsion according to one or more of the preceding claims
    as a cleaning agent, especially for removing oily soils; or
    for cleaning and/or removing compounds selected from the group consisting of inks, paints, grease, oils, resins, bitumen, tar, adhesive residues, sealing compositions, abraded rubber, cosmetics and makeup residues, as well as pyrolysis products of organic compounds, especially for cleaning and/or removing soils whose organic components are polymer-based, for example, paints, adhesives, sealing compositions, polymer foams; or
    for cleaning tools contaminated with paint residues, especially tools for applying paints, for example, paintbrushes, paint rollers or paint-spraying devices; or
    for cleaning baking ovens, fireplace glass panels or a grill.
16. A process for cleaning, comprising the following steps:

    a) applying a microemulsion according to one or more of the preceding claims to a contaminated surface;

    b) optionally allowing the microemulsion to act for some time; and

    c) removing the contaminant.