EP0088866B1 - Aqueous stable suspensions of water-insoluble silicates capable of binding calciumions, and their use in the production of washing and cleaning agents - Google Patents

Abstract

There are provided aqueous pumpable stable suspensions of a water insoluble silicate capable of binding calcium ions which contain based on the total weight of the aqueous suspension (A) as the silicate capable of binding calcium 0.5 to 80 weight percent of a finely divided, bound water containing, synthetically produced, water insoluble compound of the general formula (Cat2/nO)x.Me2O3.(SiO2)y (I), in which Cat is a cation exchangeable with calcium and which has the valence n, x is a number from 0.7 to 1.5, Me is boron or aluminum and y is a number between 0.8 and 6 and (B) as a dispersingly active component 0.5 to 6 weight percent of a mixture of at least two different alkylphenolethoxylates of the formula <IMAGE> (II) where R is an alkyl group of 1 to 15 carbon atoms. The component A especially can be a zeolite A while component B can consist of two alkylphenolethoxylates of formula (II) in which m is 2 to 7 and m is 8 to 15. The suspension can be employed for the production of powdery washing agents and detergents.

Description

Processes for washing and cleaning solid materials, in particular textiles, and detergents and cleaning agents suitable for carrying out the processes have already been proposed, in which the role of the calcium complex-binding phosphates wholly or partly of finely divided, capable of binding calcium, water-insoluble aluminum silicates containing generally bound water is taken over (cf. DE-A 2412837).

in der Kat ein mit Calcium austauschbares Kation der Wertigkeit n, x eine Zahl von 0,7 bis 1,5, Me Aluminium und y eine Zahl von 0,8 bis 6, vorzugsweise von 1,3 bis 4, bedeuten.These are compounds of the general formula

in the cat, a cation exchangeable with calcium of the valence n, x is a number from 0.7 to 1.5, Me aluminum and y is a number from 0.8 to 6, preferably from 1.3 to 4.

Sodium is preferred as the cation, but it can also be replaced by lithium, potassium, ammonium or magnesium.

For the sake of simplicity, the compounds defined above which are capable of binding calcium are referred to below as “aluminum silicates”. This applies in particular to the sodium aluminum silicates to be used with preference; all statements made for their use according to the invention and all statements regarding their production and properties apply accordingly to the entirety of all the compounds defined above.

The aluminum silicates which are particularly suitable for use in detergents and cleaning agents have a calcium binding capacity of preferably 50 to 200 mg CaO / g of the anhydrous aluminum silicate. If reference is made to anhydrous aluminum silicate in the following, it means the state of the aluminum silicate which is reached after drying for one hour at 800 ° C. During this drying, the adhering and bound water is practically completely removed.

In the production of detergents or cleaning agents, in which the aluminum silicates defined above are present in addition to the usual constituents of such agents, aluminum silicates which are moist, for example still from their production, are advantageously used. The moist compounds are mixed with at least some of the remaining constituents of the agent to be produced and the mixture is transferred by known measures, such as spray drying, into the finished washing or cleaning agent as the end product, for example into a pourable product.

As part of the manufacturing process for detergents or cleaning agents outlined above, the aluminum silicates are supplied or used, for example, as an aqueous suspension. This would involve certain improvements in the suspension properties - e.g. the suspension stability and the pumpability of the aluminum silicates dispersed in the aqueous phase are still desirable.

It is known to use alkylphenol ethoxylates to form aluminum silicate suspensions. Adducts with 6 to 7 moles of ethylene oxide are preferably used (DE-A 2615698). It is disadvantageous to add a stabilizing agent to this suspension.

It has now been found that certain mixtures of alkylphenol ethoxylates have a very particular ability to stabilize suspensions of the above calcium-binding aluminum silicates in such a way that they are stable for a long time even at a high solids content and can still be pumped perfectly even after standing for a long time. Surprisingly, it has been shown that these certain mixtures are capable of keeping even moist aluminum silicates, which have a water content of 70% and less, sedimentation-stable over a long period of time without stirring.

in der Kat ein mit Calcium austauschbares Kation der Wertigkeit n, x eine Zahl von 0,7 bis 1,5, Me Bor oder Aluminium und y eine Zahl von 0,8 bis 6 bedeuten, die als dispergierend wirkenden Bestandteil (B) Nonylphenol-Ethylenoxidaddukte enthalten, und die dadurch gekennzeichnet sind, dass sie das wasserunlösliche, zum Binden von Calciumionen befähigte Silikat in Mengen von 0,5 bis 80 Gew.-% und als dispergierend wirkenden Bestandteil 0,5 bis 6 Gew.-% einer Mischung von mindestens zwei verschiedenen Alkylphenoläthoxylaten der Formel

enthalten, wobei n bei dem einen in der Mischung verwendeten Alkylphenoläthoxylat 2 bis 7 und bei dem anderen Alkylphenoläthoxylat 8 bis 15 bedeutet, R eine Alkylgruppe mit 1 bis 15 C-Atomen und a gleich 1, 2 oder 3 ist.The invention relates to aqueous, pumpable, stable suspensions of a water-insoluble silicate capable of binding calcium ions in the form of a finely divided, bound water-containing, synthetically produced, water-insoluble compound (A) of the general formula

in the cat a cation exchangeable with calcium of the valence n, x is a number from 0.7 to 1.5, Me boron or aluminum and y is a number from 0.8 to 6, which as the dispersing component (B) nonylphenol Contain ethylene adducts, and which are characterized in that they contain the water-insoluble silicate capable of binding calcium ions in amounts of 0.5 to 80% by weight and as a dispersing component 0.5 to 6% by weight of a mixture of at least two different alkylphenol ethoxylates of the formula

contain, where n is 2 to 7 in the alkylphenol ethoxylate used in the mixture and 8 to 15 in the other alkylphenol ethoxylate, R is an alkyl group with 1 to 15 C atoms and a is 1, 2 or 3.

In formula II, R is, for example, -CH ₃ , -C ₂ H ₅ , propyl, butyl, pentyl, hexyl, heptyl or octyl or preferably an alkyl group with 9 carbon atoms such as nonyl. The phenyl ring can be substituted with the radical R in the ortho, meta and / or para position. Mixtures of compounds of the formula 11 can also be used which, in addition to compounds with p-substituted phenyl ring, also compounds with o-substi contained phenyl ring. Mixtures are preferably used in which 90% of the compounds of the formula II have a p-substitution and 10% have an ortho-substitution.

n is preferably 4 to 6, in particular 5, for the alkylphenol ethoxylate used in the mixture and preferably 8 to 12, in particular 9 or 10, for the other alkylphenol ethoxylate.

In the suspension according to the invention, component A is preferably crystalline.

In the formula of component A, y is preferably a number from 1.3 to 4.

In a preferred embodiment, crystalline component A is a type A zeolite.

The above-mentioned compounds are the essential components of the suspension according to the invention. However, other ingredients may also be included, e.g. foam-suppressing additives or so-called solubilizers, i.e. Compounds that improve the solubility of the added dispersants in the aqueous phase. The usual foam-suppressing substances, for example foam-suppressing soap, silicone defoamers, foam-suppressing triazine derivatives, all of which are known and familiar to the person skilled in the art, can be used as foam suppressors. Such an addition is generally not necessary; in the case of foaming dispersants, however, it may be desirable, especially when using higher amounts of alkylbenzenesulfonic acid.

The addition of solubilizing substances is also generally not necessary, but may be appropriate if the suspension according to the invention contains a hydrophilic, but sparingly water-soluble colloid, such as polyvinyl alcohol, as a stabilizing agent. It is advantageous e.g. a solubilizer - dimethyl sulfoxide is very suitable - if the concentration of a stabilizing agent of group 1, which is only slightly soluble in water, is higher than 1%. The proportion of the solubilizer in the total suspension can, for example, be of the same order of magnitude as the proportion of the stabilizing agent. Other compounds suitable as solubilizers are generally known to the expert; Hydrotrophic agents such as, for example, benzenesulfonic acid, toluenesulfonic acid, xylenesulfonic acid or their water-soluble salts or also octyl sulfate are suitable.

For all information on the “concentration of aluminum silicates”, the “solids content” or the content of “active substance” (= AS), reference is made to the condition of the aluminum silicates, which is reached after drying at 800 ° C for one hour. During this drying, the adhering and bound water is practically completely removed.

The aluminum silicates of component A to be used can be amorphous or crystalline products, it also being possible, of course, to use mixtures of amorphous and crystalline products and also partially crystalline products. The aluminum silicates can be naturally occurring or else synthetically produced products, the synthetically produced products being preferred. They can be prepared, for example, by reacting water-soluble silicates with water-soluble aluminates in the presence of water. For this purpose, aqueous solutions of the starting materials can be mixed with one another or a component present in the solid state can be reacted with the other component present as an aqueous solution. The desired aluminum silicates are also obtained by mixing the two components present in the solid state in the presence of water. Aluminum silicates can also be produced from Al (OH) ₂ , A1 ₂ 0 ₃ or SiO _z by reaction with alkali silicate or aluminate solutions. The production can also be carried out by other known processes. In particular, the invention relates to aluminum silicates which have a three-dimensional space lattice structure.

The preferred calcium binding capacity, which is approximately in the range from 100 to 200 mg CaO / g AS, usually around 100 to 180 mg CaO / g AS, is found above all in compounds of the composition:

This molecular formula comprises two types of different crystal structures (or their non-crystalline precursors), which also differ in their molecular formulas. They are:

The different crystal structures are shown in the X-ray diffraction diagram.

The amorphous or crystalline aluminum silicate present in aqueous suspension can be separated from the remaining aqueous solution by filtration and at temperatures of e.g. Dry 50 to 400 ° C. Depending on the drying conditions, the product contains more or less bound water.

Such high drying temperatures are generally not recommended; Expediently, the temperature does not exceed 200 ° C. if the aluminum silicate is intended for use in detergents and cleaning agents. However, the aluminum silicates do not need to be dried at all after their preparation in order to prepare a suspension according to the invention; rather - and this is particularly advantageous - an aluminum silicate that is still moist from manufacture can be used. However, dried aluminum silicates can also be used to prepare suspensions according to the invention at medium temperatures, for example from 80 to 200 ° C., until the adhering liquid water has been removed.

The particle size of the individual aluminum silicate particles can be different and e.g. are in the range between 0.1 µm and 0.1 mm. This refers to the primary particle size, i.e. the size of the particles obtained during the precipitation and, if appropriate, the subsequent crystallization. It is particularly advantageous to use aluminum silicates which consist of at least 80% by weight of particles with a size of 10 to 0.01 µm, in particular 8 to 0.1 µm.

These aluminum silicates preferably no longer contain primary or secondary particles with diameters above 45 μm. Secondary particles are particles that are formed by agglomeration of the primary particles into larger structures.

With regard to the agglomeration of the primary particles into larger structures, the use of the aluminum silicates which are still moist from their production for the production of the suspensions according to the invention has proven particularly useful since it has been found that the formation of secondary particles is practically completely prevented when these still moist products are used.

In a particularly preferred embodiment of the invention, powdered zeolite of type A with a particularly defined particle spectrum is used as component A.

Such zeolite powder can according to DE-B 24 47 021, DE-B 2517218, DE-A 2652419, DE-A 26 51 420, DE-A 26 51 436, DE-A 26 51 437, D EA 26 51 445, D EA 26 51 485 can be produced. They then have the particle distribution curves given there.

In a particularly preferred embodiment, a powdery zeolite of type A can be used, which has the particle size distribution described in DE-A 26 51 485.

The concentration of component A can preferably be 44 to 55% by weight, in particular 46 to 52% by weight and more.

The alkylphenol ethoxylates (component B) can be used in any mixture, preferably in a ratio of 1: 9 to 9: 1, preferably 2: 3 to 3: 2, in particular 0.9: 1.1 to 1.1: 0.9 will.

The concentration of this mixture in the aqueous suspension is 1 to 2% by weight, in particular 1.4 to 1.6% by weight. This concentration is sufficient to stabilize a suspension with a solids content of 50% by weight or more.

The suspension according to the invention has the advantage that it is sedimentation-stable in the temperature range from 10 to 50 ° C. and has a pumpable consistency.

A further advantage is that the alkylphenol ethoxylate is liquid at room temperature and therefore does not need to be heated.

It is particularly advantageous that significantly higher solids contents of 50% by weight and more can be achieved in the suspension according to the invention.

The known suspension has a lower sedimentation stability and, with the same type of incorporation, is not homogeneous at room temperature and is therefore more difficult to process.

In principle, the aqueous suspensions can contain, in addition to the constituents A and B mentioned and, in addition to any starting materials for the production of these constituents, any remaining constituents, also further constituents in comparatively small amounts. If the suspension is to be further processed into detergents and cleaning agents, the additional substances present are of course expediently substances which are suitable as constituents of detergents and cleaning agents.

An indication of the stability of the suspensions is provided by a simple test in which an aluminum silicate suspension of the desired concentration, e.g. 31% - is produced, which contains a dispersant according to the invention and optionally further substances, for example detergent components such as pentasodium triphosphate, in different amounts. The influence of the added substance can then be visually observed in the settling behavior of the suspension. After standing for 24 hours, a preferred suspension should generally be at most so far removed that the protruding clear or silicate particle-free solution does not make up more than 20%, preferably not more than 10%, in particular not more than 6% of the total height. In general, the amount of additives should be kept in such a way that the suspension can still be pumped perfectly again after 12 hours, preferably after 24 hours and in particular also after 48 hours in the storage container and pipe or hose lines. The settling behavior of the suspension, which may also contain other constituents, is checked at room temperature - with a total height of the suspension of 10 cm. They are perfectly pumpable even after 4 or 8 days. This information on the stability of the suspension also only gives indications; It depends on the individual case which suspension stability is to be set. If the suspension according to the invention is used as a stock suspension for prolonged storage in a reservoir from which it can be drawn off by pumping as required, it may be expedient to keep the proportion of other constituents, for example of detergents and cleaning agents, low or to dispense with them entirely.

The suspensions can be prepared by simply mixing their constituents, the aluminum silicates, for example as such or, if appropriate, from their preparation, can be used already in a moist state or in an aqueous suspension. It is particularly advantageous if they are still moist from their manufacture Stir aluminum silicates into component B, for example as a filter cake.

However, it is of course also possible to use dried, i.e. Aluminum silicates freed from adhering water and possibly still containing water can be used.

The suspensions according to the invention are distinguished by high stability and by further advantages. Their stabilizing effect is particularly valuable in the case of aluminum silicates with particle sizes from 5 to 30 pm. They are pumpable so that they allow easy handling of moist aluminum silicates. The suspensions can be pumped around perfectly even after long interruptions in the pumping process. Due to their high stability, the suspensions can also be transported in conventional tank and tank wagons without fear of the formation of unusable or disruptive residues. This makes the suspensions ideal as a form of delivery of aluminum silicates for delivery to detergent manufacturers, for example.

The suspensions can be stored at room temperature or at higher temperatures, pumped through pipes or transported in some other way. The suspensions are usually handled at temperatures between room temperature - usually preferred - and around 60 ° C.

The suspensions according to the invention are particularly suitable for further processing to appear dry, pourable or free-flowing products, for example for the production of powdered water softening agents, for. B. on the way of spray drying, suitable. The suspensions are therefore of considerable importance in the production of powdered aluminum silicates. There are no annoying residues when feeding the aqueous suspensions to the drying apparatus. It has also been shown that the suspensions of the invention enable processing to extremely dust-free products.

Due to their particular stability, the suspensions according to the invention are already as such, i.e. usable without further processing, with or without further washing, bleaching and / or cleaning additives, for example as water softening agents, washing or cleaning agents and in particular as liquid abrasives with increased suspension stability.

A particularly important use of the suspension is the further processing to give dry-appearing, free-flowing or free-flowing detergents and cleaning agents which contain further compounds in addition to the suspension components.

The suspensions according to the invention are particularly suitable for the production of powder detergents.

To prepare these agents, an aqueous, flowable premix of the individual constituents of the agents is used and converted into a pourable product in the usual way. The aluminum silicates defined above are used in the form of the suspension according to the invention. The suspensions according to the invention can be processed into solid, pourable washing and cleaning agents by any known method.

In particular, in the production of powdery, free-flowing detergents and cleaning agents, a suspension according to the invention - for example from a storage container - is mixed with at least one washing, bleaching or cleaning component of the agent to be prepared and the mixture is then processed by any process converted into the powdered product. A complexing agent is advantageously added, i.e. a compound that is able to complexly bind the alkaline earth metal ions responsible for water hardness, especially magnesium and calcium ions.

In general, in the production of washing and cleaning agents, the suspension according to the invention is preferably combined with at least one water-soluble surfactant which does not belong to the possible components of component B.

There are different variants in the manufacture of detergents and cleaning agents.

For example, the suspensions according to the invention can be combined with substances capable of binding water of crystallization, expediently by spraying the suspension onto the compounds which are capable of binding water of crystallization and which have been introduced into a mixer, so that an ultimately solid, dry-appearing product is obtained with constant mixing. However, the suspensions according to the invention, when mixed as a “slurry”, are preferably subjected to the atomization drying with at least one further washing, bleaching or cleaning compound. This shows further surprising advantages of the claimed aluminum silicate suspension. It has been shown that very low-dust products can be obtained when using suspensions according to the invention in the spray drying. The products obtained by spray drying have a high calcium binding capacity and are easily wettable.

Detergents which have been produced using the suspension described above can be composed in various ways. In general, they contain at least one water-soluble surfactant which does not belong to the dispersants used according to the invention and which are present in the claimed aluminum silicate suspensions. In general, they contain, in addition to at least one further compound which has a washing, bleaching or cleaning action and is inorganic or organic, a calcium-binding compound such as Aluminum silicate defined above. In addition, other customary auxiliaries and additives, which are usually present in smaller amounts, can be present in such agents.

Examples

A zeolite A filter cake is stirred with water and stabilizer.

Beurteilung von Homogenität und Fliessverhalten erfolgt nach Schulnotensystem (Die beste Leistung wird mit 1 und die schlechteste Leistung mit 6 bezeichnet) nach der Lagerzeit. Die Viskosität wird frisch gemessen, ändert sich jedoch bei homogenen Proben während der Lagerzeit nicht.

Compounds corresponding to formula 11, where n = 5.9 and 10 and R = nonyl, are used as stabilizers. The degree of ethoxylation EO is given. The zeolite A filter cake used is produced according to DE-A 26 51 485 and has the particle spectrum specified there.

Assessment of homogeneity and flow behavior is based on the school grade system (the best performance is 1 and the worst performance 6) after the storage period. The viscosity is measured fresh, but does not change with homogeneous samples during the storage period.

In the following Examples 26 to 37, compounds of the formula II, where n = 5, 9, 7 and 12 and R = nonyl and octyl, can be used. The zeolite A used is identical to that of Examples 1 to 25 above.

Homogeneity and flow behavior are assessed according to the school grading system after the storage period. The viscosity is measured fresh, but does not change with homogeneous samples during the storage period.

Claims (7)

1. Aqueous, pumpable, stable suspensions of water-insoluble silicates capable of binding calcium ions, in the form of a finely-divided, synthetically produced, water-insoluble compound (A) of the general formula

which contains bound water and wherein Kat represents a cation of the value n which can be exchanged by clacium, x represents a number of from 0.7 to 1.5, Me represents boron or aluminium and y represents a number of from 0.8 to 6, which suspensions contain nonylphenol-ethylene oxide adducts as dispersing agent (B), characterised in that they contain the water-insoluble silicate capable of binding calcium ions in quantities of from 0,5 to 80% by weight and from 0.5 to 6% by weight of a mixture of at least two different alkylphenolethoxylates of the formula

as dispersing agent, wherein n in one of the alkylphenolethoxylates used in the mixture represents from 2 to 7 and in the other alkylphenolethoxylate represents from 8 to 15, R represents an alkyl group having from 1 to 15 carbon atoms and a is 1,2or3.

2. Suspensions according to claim 1, characterised in that the component A is crystalline.

3. Suspensions according to claims 1 or 2, characterised in that, in formula I of component A, y represents a number of from 1.3 to 4.

4. Suspensions according to claims 1 to 3, characterised in that component A is a zeolite A.

5. Suspensions according to claims 1 to 4, characterised in that the component B consists of a mixture of two alkylphenolethoxylates of formula II, in which in one of the alkylphenolethoxylates n equals from 4 to 6 and in the other alkylphenolethoxylate n equals from 8 to 12.

6. Suspensions according to claim 5, characterised in that the mixing ratio of the two alkylphenolethoxylates is from 1:9 to 9:1.

7. The use of the aqueous suspensions according to claims 1 to 6 for the production of powder form washing and cleaning agents.