EP1824956A1

EP1824956A1 - Method for improving the efficiency of surfactants and emulsifiers by means of additives

Info

Publication number: EP1824956A1
Application number: EP05823407A
Authority: EP
Inventors: Jürgen Allgaier; Henrich Frielinghaus; Christian Frank
Original assignee: Forschungszentrum Juelich GmbH
Current assignee: Forschungszentrum Juelich GmbH
Priority date: 2004-12-08
Filing date: 2005-12-01
Publication date: 2007-08-29
Also published as: WO2006060993A1; DE102004058956A1; US20090099304A1; CN101072860A; JP2008522796A

Abstract

The invention relates to a method for improving the efficiency of surfactants with the simultaneous suppression of lamellar mesophases, in particular in micro-emulsions and emulsions and to surfactants, which are mixed with an additive. According to the invention, to improve the efficiency of the surfactants, a block copolymer of type AB, ABA or BAB is added to latter, said polymer comprising a water-soluble block A and an oil-soluble block B, which is a polyalkylene oxide, whose monomer units contain at least 4 carbon atoms. Said block copolymers also prevent lamellar mesophases, stabilise the temperature of the one-phase ranges for oil, water or surfactant mixtures, enlarge the structural quantity and reduce the interfacial tension of said mixtures.

Description

Process for increasing the efficiency of surfactants and emulsifiers by means of additives

The invention relates to a process for increasing the efficiency of surfactants and emulsifiers by additives, in particular in microemulsions and emulsions.

Emulsions and microemulsions are stabilized according to the prior art by, for example, nonionic, anionic or cationic surfactants or emulsifiers. In the following, the term surfactant is used, of which, however, emulsifiers are expressly included.

Surfactants are able to solubilize water-immiscible liquids (oils) in water or water in oil. The efficiency of the surfactants is expressed in the amount of surfactant needed to solubilize a certain amount of oil in the water or vice versa. In the case of water-oil-surfactant mixtures, a distinction is generally made between emulsions and microemulsions. While microemulsions are thermodynamically stable, emulsions are thermodynamically unstable and disintegrate.

Emulsions and microemulsions find their technical application z. As in cleaners and care products, hair and personal care products, in crop protection for the stabilization of microbicidal agents, in the production of dyeing and coating systems and in the pharmaceutical sector. In the technical formulation of emulsions and microemulsions, however, unwanted lamellar mesophases often occur. Lamellar mesophases lead to optical anisotropy and increased viscosity. These properties are for. As undesirable for detergents, since the lamellar mesophases are not washable. They are also undesirable in formulations for crop protection because they lead to the blockage of the spray nozzles.

A further problem in the technical formulation of emulsions and microemulsions is the temperature behavior. In particular, the addition of an additive generally leads to a shift of the one-phase areas which are important for industrial use into other temperature ranges. The shifts can be in the order of 10 ⁰ C and more. However, this has the consequence that, for example, formulations have to be changed in order to adapt them to the respectively newly occurring temperature behavior of the single-phase region.

In addition, there is a need to obtain at least equally good formulations while avoiding surfactants. In addition to cost reasons, the surfactant savings may also be advantageous for environmental reasons. In addition, surfactants used for product stabilization are often undesirable in the actual application. German Patent Application 198 39 054.8-41 discloses a method for increasing the efficiency of surfactants with simultaneous suppression of lamellar mesophases, a method for stabilizing the Temperaturläge the Einphasengebietes for oil, water, surfactant mixtures, a method for increasing the structure size of emulsified liquid particles in microemulsions and a method for reducing the interfacial tension of oil-water mixtures to which AB block copolymers having a water-soluble block A and a water-insoluble block B are added.

It has been found that, in particular, AB block copolymers which contain a polyalkane as the water-soluble block PEO (polyethylene oxide) and as a water-insoluble block are suitable as additives. However, the preparation is only possible in a multi-step process under different reaction conditions. In the first step, a diene (butadiene or isoprene) is polymerized by means of an organolithium initiator. Subsequently, OH functionalization of the polymer chains with ethylene oxide. Thereafter, the remaining carbon double bonds in the polymer are hydrogenated. The intermediate product obtained is a polyalkane, each polymer chain being functionalized with an alcoholic OH group. In analogy to the ethoxylation of fatty alcohols, ethylene oxide is finally polymerized onto the polyalkane alcohol by first completely or partially converting the polyalkane alcohol into the corresponding sodium or potassium alcoholate. This process requires the use of expensive organolithium compounds, high purity conditions in the anionic diene polymerization and the isolation and purification of the polyalkane alcohol obtained as an intermediate. The production of polyalkane PEO

Block copolymers is therefore costly. In addition, high viscosities occur during the ethoxylation of the polyalkane, especially when no solvents are added. The most pronounced increase in viscosity is to be seen when a state is passed through in the course of the block copolymer formation in which the two polymer blocks are present in approximately equal proportions by volume. The high viscosity is then caused by the fact that the two polymer blocks mikrophasensepa- rage and lamellar superstructures form. The high viscosity of the polymer impedes or prevents stirring in the reactor with negative consequences for the reaction. To lower the viscosity, solvent must be used or the reaction temperature must be greatly increased. Apart from the manufacturing process, high viscosities also hinder the formulation of polyalkane-polyethylene oxide block copolymers in products.

It is therefore the object of the invention to increase the efficiency of surfactants or emulsifiers in emulsions or microemulsions and to reduce the interfacial tension by polymers that are easier to prepare and easier to formulate. Emulsions and microemulsions should be stabilized with less surfactant, ie surfactants should be saved in formulations. Furthermore, the occurrence of lamellar phases in microemulsions tions are suppressed. The temperature behavior of the emulsions and microemulsions should remain unaffected by additives, ie the position of the single-phase region in the phase diagram should not be substantially influenced by the addition of the additive with respect to the temperature. An additive is likewise to be made available which brings about the abovementioned advantages and can be added, for example, to a cleaning agent without the need for a formulation change of the remaining formulation. Furthermore, an additive is to be provided which can be used in cleaners and / or in emulsions and / or microemulsions and effects a reduction in the amount of surfactant required for the activity. These include household cleaners, industrial cleaners, industrial process cleaners, hair and personal care products, food, plant protection products, paints and coatings, pharmaceuticals, home care and household ingredients, industrial and industrial applications. This additive should be particularly easy to prepare and emulsify oils in water or water in oils. This creates a possibility to produce microemulsions whose size of the emulsified liquid particles correspond to those of emulsions.

Surprisingly, starting from the preamble of claim 1, all objects are achieved according to the invention in that a polyalkylene oxide block copolymer having a water-soluble block A and an oil-soluble block B is used as the additive. Block A is preferably not soluble in oil and block B is preferably not soluble in water.

Block A is preferably made of PEO but also copolymers of ethylene oxide with higher alkylene oxides such as propylene oxide and / or butylene oxide are possible, but without block A loses its solubility in water.

Within a block A, the monomer components can occur in any order. Preferably, the individual components are at least partially alternating. In a further preferred embodiment, the monomer units of the block A have a stochastic sequence.

Block A should preferably still not be soluble in oil.

Block B, on the other hand, preferably prefers an oil-soluble polyalkylene oxide having at least 4 carbon atoms in the monomer building block, preferably polybutylene oxide, polypentylene oxide and polyhexylene oxide, but also other polyalkylene oxides having at least four carbon atoms in the monomer building block.

A block B can consist of at least two components from the group of polybutylene oxide, polypentylene oxide and polyhexylene oxide, but also other polyalkylene oxides having at least four carbon atoms in the monomer unit. Block B may also comprise ethylene oxide provided that the oil solubility is present.

Block B should preferably still not be soluble in water.

Furthermore, triblocks of the structure ABA or BAB can be used, and star-shaped polymers of structure (AB) _n or (BA) _n , where n represents the number of arms in the star polymer, wherein the center of the

Star structure by, for example, an n-valent alcohol with n = number of OH groups or an m-valent amine with m = number of amino groups and n = number of nitrogen-bonded H atoms. In the case of (AB) _n the component A is connected to the center of the star and in the case (BA) _n the component B is connected to the center of the star.

The efficiency of the surfactants is expressed in the amount of surfactant needed to solubilize a certain amount of oil in the water or vice versa. The lower the amount of surfactant required for the same effectiveness, the higher the efficiency. An increase in efficiency is also given when an emulsion at the same surfactant concentration with the addition of efficiency-increasing additive is stable for a long time. An increase in efficiency within the meaning of the invention is present if at least one of the two options is fulfilled. Advantageous developments of the invention are specified in the subclaims.

The blocks A and B can assume molecular weights preferably between 1000 g / mol and 50,000 g / mol, and more preferably between 3000 g / mol and 20,000 g / mol.

As block A, a polyethylene oxide block is preferably used. Further, as block A, a copolymer of ethylene oxide and propylene oxide, which is soluble in water, is also used.

Block B according to the invention is a polyalkylene oxide block having at least 4 C atoms in the monomer building block.

The AB block copolymers used according to the invention can preferably be obtained from an alkoxylation by sequential polymerization of the blocks.

Advantageously, block B is soluble in mineral oils or aliphatic hydrocarbons as well as ester oils.

At molecular weights of blocks A and B of the order of 3000-20000 g / mol for blocks A and B, particularly advantageous properties of the AB block copolymers used according to the invention in application products are observed. Thus, the polymers dissolve with these comparatively low molecular weights fast and good, ie the polymers are easily incorporated into surfactant.

In the AB block copolymers used according to the invention, the two blocks A and B should have the greatest possible difference in their polarity. Block A is as polar as possible and block B is preferably nonpolar. This increases the amphiphilic behavior.

Block A is water soluble and Block B is soluble in nonpolar media.

Block B is advantageously soluble in mineral oils, high-boiling esters or aliphatic hydrocarbons or in mineral oils. This preferably also applies at room temperature.

Furthermore, the AB triblock copolymers with the pattern ABA and BAB and star-shaped polymers of this monomer sequence have the same inventive effect and are therefore encompassed by the invention.

Furthermore, star-shaped polymers of the structure (AB) _n or (BA) _n are also encompassed by the invention, where n symbolizes the number of atoms in the star polymer, the center of the star structure being replaced by, for example, an n-valent alcohol with n = number of OH atoms. Groups or an n-valent amine with n = number of amine groups. These star-shaped polymers also have the effect according to the invention. By way of example, but not limitation, the following surfactants / emulsifiers (C) and mixtures thereof with the additives according to the invention can be used: nonionic surfactants of the class alkylpolyglycol ether (CiEj) with i> 8 (C = C atoms in the alkyl chain, E = ethylene oxide unit. ) nonionic surfactants of the class alkyl polyglucosides (APG, "sugar surfactants", CiGj with i> 8) with cosurfactant alcohol (C _x -OH, x> 6) anionic surfactants, eg AOT (sodium bis (2-ethylhexyl) sulfosuccinate), alkyl sulfates, Alkyl sulfonates cationic surfactants

Mixtures of surfactants, in particular nonionic / anionic.

According to the invention, the addition of the polyalkylene oxide block copolymers to the water-oil-surfactant mixture, the position of the single-phase region in the phase diagram in the same temperature range, the efficiency of the surfactant mixture is considerably increased, lamellar mesophases are controlled in microemulsions and the interfacial tension is lowered. In addition, microemulsions retain their characteristic properties while increasing their structure size; Thus, the emulsified structures take on sizes of up to about 2000 angstrδm. The size of the emulsified liquid particles depends on the temperature and the amount of block copolymer added, or thus on the composition of the surfactant mixture. The additives of the invention are for industrial cleaning processes and Emulsifying processes suitable. They emulsify organic, in the emulsion process in liquid form present non-water-soluble substances and vice versa (w / o and o / w) and are particularly easy to produce.

The preparation of polyalkylene oxide block copolymers is much simpler than the preparation of polyalkane-PEO block copolymers. The synthesis can be carried out in a one-pot process using low molecular weight sodium or potassium alcoholates, such as, for example, sodium methoxide, sodium ethanolate, sodium tert-butoxide, potassium methoxide, potassium ethanolate, potassium tert-butoxide.

It is also possible to use alcoholate / alcohol mixtures.

The polymerization is carried out in which the grafted an alkylene oxide (ethylene oxide or optionally the higher alkylene oxide) is polymerized first, and after completion of the polymerization, the other alkylene oxide ^'. The isolation and purification of an intermediate product is eliminated. The production process is particularly simple since the product can be made in a one-pot reaction without intermediate work-up. In addition, significantly lower viscosities occur during the polymerization of the second monomer than with polyalkane-PEO block copolymers. This makes it possible to use less solvent or to dispense with it in the block copolymer preparation or to increase the reaction temperature less than with polyalkane-PEO copolymers.

Due to the lower viscosity, polyalkylene oxide block copolymers are easier to prepare than polyalkane-PEO block copolymers. It is also easier to formulate polyalkylene oxide block copolymers, since solution and mixing processes proceed more rapidly.

The different viscosity behavior is demonstrated by way of example on two diblock copolymers, each consisting of about 50% by volume of PEO (Table 1). PEB5-PEO5 is a polyalkane -PEO block copolymer and contains, as a hydrophobic block, poly (ethylene-co-butylene) where the ratio of ethylene to 1-butylene monomer units is 2: 1. PBO5-PEO5 is a polyalkylene oxide block copolymer and contains poly (1, 2-butylene oxide) as a hydrophobic block. Table 1 shows the molecular weight characterization of the two diblock copolymers.

The viscosities of the two block copolymers were measured using a Rheometric Science ARES Rheometer at various temperatures. For this purpose, about 0.5 g of block copolymer were processed at 70 ⁰ C to a homogeneous pressure of 25 mm diameter and 1 mm thickness.

In Table 2, for various temperatures, the viscosities for the frequencies ω = l / sec and ω = lθ / sec. listed. The measured viscosity values are high for both block copolymers compared to homopolymeric ren of the same molecular weights, since both blocks are present in approximately equal volumes and thus a lamellar microphase separation occurs. However, the polyalkylene oxide block copolymer has a viscosity lower by about a factor of 3 than the polyalkane-PEO block copolymer, although the former has a molecular weight which is 1.6 times higher.

For miscibility, in addition to the viscosity behavior, the miscibility of the components is of crucial importance. Polyalkane-PEO block copolymers are generally immiscible with surfactants or emulsifiers. This creates stability problems during storage. The mixtures can also become solid, which results in handling difficulties. Alternatively, the components must be dosed separately in applications, heated, or large amounts of water added to mix the polymer and surfactant homogeneously.

In contrast, polyalkylene oxide block copolymers are in the

Usually miscible with surfactants or it suffice small amounts of water to produce homogeneous block copolymer / surfactant mixtures.

For the surfactants and emulsifiers listed in Table 3, mixtures were prepared with the polymers listed in Table 1 to check the miscibility. The two polymers are waxy solids at room temperature, the surfactants and emulsifiers liquid. Table 3 shows surfactants and emulsifiers for mixing experiments with polymers. The trademarks indicated in the examples designate surfactants or emulsifiers which are exemplary for the substance classes given below:

Tergitol ^® 15-S-5:

PEG ether of a mixture of synthetic Cll-15 fatty alcohols with about 5 moles of EO

Tergitol ^® 15-S-12: PEG ether of a mixture of synthetic Cll-15 fatty alcohols having about 12 moles of EO

Tween ^β 80:

Mixture of oleate esters of sorbitol and sorbitol anhydrides with about 20 moles EO Tween ^Φ 81:

Mixture of oleate esters of sorbitol and sorbitol anhydrides with about 5 moles of EO

Span ^S> 20:

Monoesters of lauric acid and hexitol anhydride derivatives of sorbitol.

Mixtures of 90% by weight of surfactant and 10% by weight of polymer were stirred at room temperature for 1.5 hours and at 50 ^° C. for 1.5 hours. At 50 ^° C. thereafter, all the mixtures were clear and liquid. The appearance after cooling to room temperature is summarized in Table 4. Subsequently, the mixtures were mixed with deionized water, so that the water content was 10 wt .-%. It was again stirred at 50 ⁰ C for 1.5 hours. At this temperature all the mixtures were again clear and liquid, only the mixtures of PEB5-PEO5 with Tween® 80, Tween® 81 and Span® 20 showed slight turbidity. The appearance after renewed cooling to room temperature is summarized in Table 4.

Of the surfactant blends with PBO5-PEO5, three are liquid and three are solid, whereas of the surfactant blends with PEB5-PEO5, only one is liquid and 5 solid. After adding 10% of water to the surfactant-polymer mixture, all mixtures containing PBO5-PEO5 are now liquid and homogeneous, whereas in all mixtures with PEB5-PEO5 the polymer has precipitated. Even after five days of storage at room temperature, the appearance of the mixtures did not change.

In the following, the invention will be explained by way of example.

The AB block copolymers of the invention can be prepared as exemplified below.

Preparation Process for Polyalkylene Oxide Block Copolymers, Example Poly (1, 2-Butylene Oxide) Polyethylene Oxide Block Copolymer:

Into a 0.5 L steel reactor flooded with argon inert gas, 2.8 mL of a 0.90 molar potassium tert-butoxide solution in THF was added. The solvent was distilled off in vacuo. Subsequently, 0.22 g of tert-butanol and 27.7 g of 1,2-butylene oxide were condensed into the cooled reactor. The mixture was heated with stirring under argon pressure 17 hours at 80 ⁰ C. Thereafter, unpolymerized butylene oxide was distilled off in vacuo (1.3 g) and 29 g of anhydrous toluene condensed in the cooled reactor. 13.5 g of the polymer-toluene mixture was removed from the reactor for separate analysis of the PBO block. Subsequently, 20.8 g of ethylene oxide were condensed into the cooled reactor. The mixture was heated with stirring under argon pressure for 15 hours over 60 ⁰ C. Thereafter, 1 mL of acetic acid was added and the product mixture was drained through a bottom valve. After distilling off the solvent, a waxy mass was obtained, which was dried overnight in vacuo to remove residual solvent and acetic acid residues. 40.6 g of block copolymer was obtained. As an alternative to acetic acid, it is also possible to add an alkylating agent, such as, for example, methyl chloride or ethyl chloride.

The molecular weight of the PBO block was obtained by ¹ H-NMR by comparing the signal intensity of the tert-butly initiator unit with the intensities of the polymer signals. The composition of the polymer and thus the molecular weight of the PEO block was obtained by ¹ H-NMR by intensity comparison of the PBO signals with the PEO signals. Molecular weight distributions were determined by GPC. The values listed in Table 5 were determined. For the examination of the microemulsions and emulsions, the polymers listed in Table 6 were used.

The polymers were characterized in the same way as described in the previous section. Only the PBO molecular weight of PEO2-PBO2-PEO2 was determined by GPC coupled online light scattering detection.

The behavior of the microemulsions according to the invention is shown in FIGS. 1-4:

Some terms are to be defined below: C = Any surfactant or emulsifier, such as anionic, cationic, nonionic or sugar surfactant, and mixtures thereof containing at least two surfactants.

D = additive which is added to the surfactant C according to the invention.

γ = total surfactant concentration (mass fraction) from C and

7 «(C) + TO (D) γ =

D with ^m « ^a

Herein: m = mass in g.

γ = dimensionless mass fraction

= total mass of _water + r + ^ öi + tn (C) + m (D) Υ = total surfactant concentration at the crossing point where the phase diagram meets the single-phase to the three-phase region. This corresponds to the total surfactant concentration required for a complete solubilization of water and oil for a given water / oil ratio.

δ = mass fraction of the additive D in the mixture of surfactant C + _δ _ m (D)

Additive D, corresponds to m (C) + m (D) with m = mass in g and

δ = mass fraction (dimensionless)

Fig.l: Temperature / Tensidkonzentrationsdiagramm for the mixture water - n-decane - Ci ₀ E ₄ -PBO5-PEO5 as a function of the addition of PBO5-PEO5 (δ) at a constant water / oil ratio of φ = 0.5.

Figure 2: Temperature / Tensidkonzentrationsdiagramm the mixture water - n-decane - Ci ₀ E ₄ - amphiphilic polymer for the polymers PEO2-PBO4-PEO2, PBO5-PEO5, PHO10-PEO13 at δ = 0.05 and a constant water / oil ratio of φ = 0.5. For comparison, the upper figure shows the phase diagram of the system without additive (δ = 0).

Figure 3: Temperature / Tensidkonzentrationsdiagramm for the mixture of water / NaCl - n-decane - AOT, exemplified by ionic surfactants, - PHOlO-PEO13 as a function of the addition PHO10-PEO13 (δ) at constant water / oil ratio of φ = 0.5. The salt content in water (ε) is 1%.

Fig. 4: Interfacial tension (σ _a b) between water and oil in a mixture of water - n-decane - C ₈ E ₃ -PBO5-PEO5 as a function of the addition PBO5-PEO5 (δ) at constant temperature T = 22.4 ° C.

The T / γ diagrams shown in FIGS. 1-3 relate to systems with a constant water / oil volume ratio of 1: 1 and will be explained below.

If the temperature T is plotted against the total surfactant concentration γ, a single phase area 1 is found at higher surfactant concentrations. This area is followed by a closed three-phase area in the direction of smaller surfactant concentrations, which is shown in FIGS. 3 has been omitted. Above and below the phase boundaries there are two-phase areas 2.

In these diagrams, the curves are plotted in each case at a δ value which characterizes the limitation of the respective single-phase region belonging to a δ value. The apex of the respective curve is the point at which different polyphase regions meet. The further the peak of a curve is located at lower surfactant concentrations, ie γ values, the greater the efficiency of the surfactant C due to the addition of the block copolymer D. FIG. 1 shows how the efficiency of the total surfactant increases with the addition of the block copolymer. Formulated to a microemulsion of equal parts of water and Dean and C ₁₀ E ₄ so be at a surfactant concentration of 12% (Y ^{= υ> 12)} between 0 ⁰ C and 100 ° C only two and three phase regions before. Replaced in the same mixture 10% of the surfactant C ₁₀ E ₄ by the

Block copolymer PBO5-PEO5 (δ = 0.10) _{/ so} you get between 30 ° C and 32 ° C a single-phase range. In addition, only a very small shift of the phase boundaries on the temperature axis is recorded. This is equivalent to the fact that the block copolymer D leaves the position of the effectiveness of the surfactant C with respect to its application temperature substantially invariant. In addition, no mesophases occur in the investigated measurements, whereas in the system without additive a higher efficiency is equivalent to the occurrence of especially lamellar mesophases.

Figure 2 shows an overview of the efficiency and temperature of various water - n-decane - C ₁₀ E ₄ - amphiphilic polymer systems, where the polymers PEO2-PBO4-PEO2, PBO5-PEO5, PHO10-PEO13 at δ = 0.05 and a constant water / oil ratio of Φ = 0.5 were used. In all the polymers used, an increase in the efficiency and a virtually unchanged temperature range are observed in comparison to the starting system with δ = 0. The increase in efficiency increases with increasing molecular weight of the triblock copolymer PEO2-PBO4-PEO2 to the block copolymer PHOlO-PEO13. In FIG. 3, the same characteristics occur with respect to the temperature behavior. However, the increase in efficiency is more pronounced due to the larger polymer PHOlO-PEO13.

The values of the water / oil interface minimum voltage in Table 7 and Figure 4 decrease markedly in the system with block copolymer with increasing polymer content (δ). This property is crucial for many washing and cleaning processes.

Example of increasing the efficiency of emulsions: Emulsions were prepared from water, decane and AOT as emulsifier. The water contained 0.30 wt% NaCl. AOT was dissolved in the aqueous phase. Emulsions were prepared using an Ultra-Turrax® T 25 basic (IKA works) at a stirring speed of 16,000 min. ^{For 1} part of the emulsions, the nonionic surfactant Tergitol® 15-S-12 or the diblock copolymer PBO5-PEO5 was used in addition to AOT. Table 8 shows the compositions of the emulsions.

After emulsification, the emulsions were filled in airtight test tubes and stored at room temperature. Over the period of 120 days, the stability of the emulsions was examined. As a measure of the stability was the amount of separated oil used.

Table 9 shows the volumes of excreted oil, based on the total volume of the emulsions, after different storage times. While Emulsion A only stabilized with AOT is quite unstable, Emulsions 2 and 3, which additionally contain Tergitol® 15-S-12, exhibit significantly better stability, even though they contain less total surfactant. However, these are also largely decayed after 120 days. The stability of emulsions 4 and 5 with PBO5-PE05 is highest, although even here larger amounts of AOT were replaced by small amounts of polymer. The polymer-stabilized emulsions are still stable even after 120 days. In other words, the polymer significantly improves the efficiency of the emulsifier AOT. The small amounts of oil separation in the emulsions 2, 3 and 5 at the beginning of the storage experiments based on incomplete emulsification of the oil.

The AB or ABA and BAB block copolymers according to the invention can be prepared particularly easily in a one-pot reaction. With the AB block copolymers used according to the invention, the interfacial tension of surfactants, such as, for example, anionic, cationic and nonionic surfactants, sugar surfactants, in particular technical surfactant mixtures, is lowered. The occurrence of lamellar mesophases is suppressed. The temperature behavior of the emulsions and microemulsions remains unchanged. dert, that is, the position of the single-phase region with respect to the temperature in the phase diagram is not affected by the addition of the additives used in the invention. Therefore, the recipe of a cleaning agent does not have to be changed in order to bring about a constant position of the single-phase area with respect to the temperature in the single-phase diagram.

The AB block copolymers of the invention and ABA and BAB tricoblock polymers can preferably be used in industrial cleaners and for stabilizing emulsions and microemulsions, for example as additives in foods and cosmetics. Furthermore, they can be used as lubricants preferably in the metal and textile sector or in paints and varnishes.

The microemulsions produced by means of the addition of the AB block copolymers according to the invention have emulsified liquid volumes which correspond to those of emulsions. The block copolymers of the invention are particularly well suited for industrial cleaning processes.

The additives are polyalkylene oxide block copolymers which can be prepared in a simple manner. With the increase in efficiency is also associated with an expansion of the temperature interval, within which the microemulsion is thermodynamically stable. This is particularly advantageous for technical applications where stability over large temperature ranges must be ensured. Table 1: Characterization of the polymers

Table 2: Polymer viscosities

Table 3

Surfactant / Emulsifier Appearance (Room Temperature)

Tetraoxyethylene decyl ether (tech. Liquid niche

Mixture with medium degree of ethoxylation 4)

Tergitol® 15-S-5 clear liquid

(Sigma)

Tergitol® 15-S-12 cloudy liquid

(Sigma)

Tween® 80 clear liquid

(Sigma)

Tween® 81 clear liquid

(Sigma)

Span® 20 clear liquid, high viscose

(Fluka)

Table 4:

The mixtures are cloudy, but even after 5 days storage at room temperature homogeneous. Table 5:

M _n M _w / M _n

PBO block 4,870 1,10

PBO-PEO 10.200 1.06

Table 6:

PBO PBO-PEO

Mn Mw / Mn wt% PEO Mw / Mn

PBO5-PEO5 6,000 1,11 54 1,07

PEO2-PBO4-PEO2 4,700 ¹ 1,03 51 1,04

PHO PHO-PEO

PHOOL-PEO13 8,500 1,08 59 1,10

Table 7: Determined interfacial tension σ between water and oil in the system H ₂ O - n-decane - C ₈ E ₃ - PBO5- PEO5.

δ σ / mNm ^"'1 * 10 ^{" 2} T / o _C

0 .000 5. 93 22 .4

0 .050 2. 71 22 .4

0 .100 1. 55 22 .4 Table 8:

Aqueous Tergi

NaCl Dean AOT tol® PBO5-PEO5

0.30% 15-S-12

Emulsion 20.0 g 14.6 g 0.72 g 1

Emulsion 20.0 g 14.6 g 0.36 g 0.070 g 2

Emulsion 20.0 g 14.6 g 0.18 g 0.040 g 3

Emulsion 20.0 g 14.6 g 0.36 g 0.071 g 4

Emulsion 20, 0 g 14.6 g 0.18 g 0.041 g 5

Table 9

Volume fraction of separated oil

1 day 7 days 30 days 120 days

Emulsion no oil 4% 45% 46% 1

Emulsion 1% 1% 1% 44% 2

Emulsion 2% 2% 2% 28% 3

Emulsion no oil no oil no oil no oil 4

Emulsion 2% 2% Δ Ό 1% 5

Claims

Patent claims

1. A process for increasing the efficiency of surfactants and emulsifiers in emulsions and microemulsions by the addition of additives, characterized in that the surfactant or the emulsifier is added as an additive, a polyalkylene oxide block copolymer having a water-soluble block A and an oil-soluble block B.

2. A process for the prevention of lamellar phases in water, oil, surfactant mixtures, characterized in that the surfactant or the emulsifier is added as additive a polyalkylene oxide block copolymer having a water-soluble block A and an oil-soluble block B.

3. A method for stabilizing the temperature position of the single-phase area for oil, water Tensidmischun- conditions, characterized in that the oil, water surfactant mixture is added as an additive, a polyalkylene oxide block copolymer having a water-soluble block A and an oil-soluble block B.

4. Process for reducing the interfacial tension of oil, water mixtures containing surfactants and / or emulsifiers, characterized in that a polyalkylene oxide block copolymer having a water-soluble block A and an oil-soluble block B is added as an additive.

5. The method according to any one of claims 1 to 4, characterized in that block A is not soluble in oil.

6. The method according to any one of claims 1 to 5, characterized in that block A consists of at least one component from the group consisting of the monomers ethylene oxide, propylene oxide, butylene oxide and higher Alkynenoxiden.

7. The method according to any one of claims 1 to 6, characterized in that as block A, a polyethylene oxide (PEO) is used.

8. The method according to claim 7, characterized in that a block A is used, in which the monomer units occur in any order.

9. Method according to one of claims 7 to 8, characterized in that blocks A are used in which the monomer units have a stochastic sequence.

10. The method according to any one of claims 1 to 9, characterized Block B is not soluble in water.

11. The method according to any one of claims 1 to 10, characterized in that the monomer units of the block B comprise at least four carbon atoms.

12. The method according to claim 11, characterized in that the monomer units of the block B at least one component from the group consisting of Buty- lenoxid, pentylene oxide and hexylene oxide and other higher alkylene oxides.

13. The method according to any one of claims 10 to 12, characterized in that a block B is used which contains ethylene oxide as the monomer unit, wherein the oil solubility must continue to exist.

14. The method according to any one of claims 1 to 13, characterized in that as a block copolymer at least one component from the group of a compounds having the structure according to the pattern AB, ABA, BAB, (AB) _n star, or (BA ) _n- star, is added.

15. The method according to any one of claims 1 to 14, characterized in that a soluble in aliphatic hydrocarbons and / or in ester oils block B is used.

16. The method according to any one of claims 1 to 15, characterized in that block A has a molecular weight between 1000 g / mol and 50,000 g / mol.

17. The method according to any one of claims 1 to 16, characterized in that block B has a molecular weight between 1000 g / mol and 50,000 g / mol.

18. oil-water mixture comprising at least one surfactant and / or at least one emulsifier and an additive consisting of a polyalkylene oxide block copolymer with a block A and a block B, characterized in that block A is water-soluble and block B is oil-soluble.

19. Mixture according to claim 18, characterized in that as additive at least one component from the group of the AB block copolymers having the structure according to the pattern AB, ABA or BAB (AB) _n star or (BA) _n - star is included.

20. Mixture according to claim 18 or 19, characterized in that block A has a molecular weight between 1000 g / mol and 50,000 g / mol.

21. Mixture according to one of claims 18 to 20, characterized in that block B has a molecular weight between 1000 g / mol and 50,000 g / mol.

22. Mixture according to one of claims 18 to 21, characterized in that block A is a polyethylene oxide.

23. Mixture according to claim 22, characterized in that a block A is used, in which the monomer units occur in any order.

24. Mixture according to one of claims 18 to 23, characterized in that block B is not soluble in water.

25. Mixture according to one of claims 18 to 24, characterized in that the monomers of the block block B comprise at least four carbon atoms.

26. Mixture according to one of claims 18 to 25, characterized in that the monomer units of the block B from at least one component from the group consisting of butylene oxide, pentylene oxide, hexylene oxide, further higher units.

27. Mixture according to one of claims 18 to 26, characterized in that a block B contains as monomer unit ethylene oxide, wherein the oil solubility continues to exist have to be .

28. A surfactant or emulsifier or mixture of surfactant and emulsifier containing as an additive an AB polyalkylene oxide block copolymer, characterized in that the AB polyalkylene oxide block copolymer has a water-soluble block A and an oil-soluble block B having at least five carbon atoms per monomer unit.

29. A surfactant or emulsifier or mixture of surfactant and emulsifier, containing as an additive an AB block copolymer according to claim 28, characterized in that as additive at least one component from the group of the AB block copolymers having the structure according to the pattern AB, ABA or BAB, (AB) _n star or (BA) _n star is included.

30. A surfactant or emulsifier or mixture of surfactant and emulsifier, containing as an additive an AB block copolymer according to claim 28 or 29, characterized in that block A has a molecular weight between 1000 g / mol and 50,000 g / mol.

31. A surfactant or emulsifier or mixture of surfactant and emulsifier containing as an additive an AB block copolymer according to any one of claims 28 to 30, characterized in that block B has a molecular weight between 1000 g / mol and 50,000 g / mol.

32. A surfactant or emulsifier or mixture of surfactant and emulsifier containing as an additive an AB block copolymer according to any one of claims 28 to 31, characterized in that block A is a polyethylene oxide.

33. A surfactant or emulsifier or mixture of surfactant and emulsifier, containing as an additive an AB block copolymer according to any one of claims 28 to 32, characterized in that a block A is used, in which the monomer units occur in any order.

34. A surfactant or emulsifier or mixture of surfactant and emulsifier, containing as an additive an AB block copolymer according to any one of claims 28 to 33, characterized in that block B is not soluble in water

35. A surfactant or emulsifier or mixture of surfactant and emulsifier, containing as an additive an AB block copolymer according to any one of claims 28 to 34, characterized in that the monomer units of the block B from at least one component selected from the group consisting of butylene oxide, pentylene oxide, Hexylene oxide, other higher units.

36. A surfactant or emulsifier or mixture of surfactant and emulsifier containing as an additive an AB block copolymer lymer according to any one of claims 28 to 35, characterized in that a block B contains ethylene oxide as a monomer unit, wherein the oil solubility must continue to exist.