WO2000031221A1 - Defoaming granulates containing fatty acid polyethylene glycol esters - Google Patents

Abstract

The invention relates to defoaming granulates containing fatty acid polyethylene glycol esters as well as to a method for producing such defoaming granulates by simultaneous granulation and drying, notably according to the SKET method, in a thin-film evaporator or by a fluid-bed process. The invention also relates to the use of said defoaming granulates for the production of solid detergents.

Description

 "Defoamer granules with fatty acid polyethylene glycol esters"

The present invention relates to defoamer granules containing

Fatty acid polyethylene glycol ester and process for producing such defoamer granules by means of simultaneous granulation and drying, in particular according to the SKET process. or in a thin-film evaporator or in a fluidized bed process, and the use of defoamer granules for the production of solid detergents.

Household and industrial laundry detergents generally contain organic surfactants, builders and numerous organic and inorganic additives. The surfactants used to clean the laundry usually tend to develop foam during the washing cycle, which has a negative effect on the washing result. There is therefore a practical need to control the foam development during the washing process and in particular to minimize it. For this purpose, defoamers or so-called anti-foaming agents are used, which on the one hand are to reduce the development of foam and on the other hand to reduce foam that has already formed.

Silicones have proven to be particularly suitable defoamers, as a rule applied to carrier materials and optionally coated with other defoaming substances and used in solid detergents.

For example, defoamers containing silicone are known from European patent application EP-AI-0 496 S10, a mixture of silicones and fatty alcohols being used as the carrier material on starch. Fatty acids or glycerol monoesters with special melting points are applied. To produce these defoamer granules, the Silicones and the other organic components are mixed in liquid form with the starch or granulated in a fluidized bed process. Spraying the silicones and the organic materials onto the carrier during the granulation proves problematic according to this method. Because of their viscosity and their sticky, oily consistency, the silicones show problems with pumpability on the one hand, and stringing and sticking in the spray nozzle on the other, which means that the desired, finely divided spraying is hardly possible. Furthermore, the silicones are relatively expensive defoamers, so that there continues to be a need to at least partially replace the silicones with other defoaming substances with a comparable defoaming effect.

It was the object of the present invention. To provide defoamer granules that are free-flowing and do not dust. Furthermore, the defoamer granules should have a good defoaming effect, the silicones being at least partially replaced by other defoaming compounds. Of course, the silicones and the other defoaming compounds had to be compatible with one another and, if possible, have the maximum defoaming effect at different temperatures. Furthermore, a process had to be developed which made it possible to produce defoamer granules with silicones without the disadvantages known from the prior art, such as thread tension and sticking in the spray nozzle, being introduced when the silicones were introduced.

One object of the present invention relates to defoamer granules for solid detergents containing silicones as defoamers and carrier materials, characterized in that they additionally contain fatty acid polyethylene glycol esters of the formula (I),

R ^l COO (CH ₂ CH ₂ O) "H (I)

in the R'CO for a linear or branched, aliphatic. saturated and / or unsaturated acyl radical with 6 to 22 carbon atoms and n stands for numbers from 0.5 to 1.5, as defoamers.

The defoamer granules according to the invention absolutely contain

Fatty acid polyethylene glycol ester of the general formula (I). Such Fatty acid polyethylene glycol esters are preferably obtained by addition of ethylene oxide onto fatty acids based on a homogeneous base, in particular ethylene oxide is added to the fatty acids in the presence of alkanolamines as catalysts. The use of alkanolamines. especially triethanolamine, leads to an extremely selective ethoxylation of the fatty acids, especially when it comes to producing low-ethoxylated compounds.

Fatty acids are to be understood as meaning aliphatic carboxylic acids of the formula (II).

R'COOH (II)

in the R'CO for an aliphatic. linear or branched acyl radical having 6 to 22, preferably 12 to 18 carbon atoms and 0 and / or 1, 2 or 3 double bonds. Typical examples are caproic acid, caprylic acid. 2-ethylhexanoic acid. Capric acid, lauric acid. Isotridecanoic acid, myristic acid, palmitic acid, palmoleic acid. Stearic acid, isostearic acid, oleic acid, elaidic acid, petroselinic acid. Linoleic acid. Linolenic acid. Elaleostearic acid. Arachic acid. Gadoleic acid, behenic acid and erucic acid as well as their technical mixtures, e.g. in the pressure splitting of natural fats and oils, in the reduction of aldehydes from Roelen's oxosynthesis or in the dimerization of unsaturated fatty acids. Technical fatty acids with 12 to 18 carbon atoms, such as coconut, palm, palm kernel or tallow fatty acids, are preferred.

Alkanolamines

Typical examples of alkanolamines. which can be used as basic catalysts are monoethanolamine. Diethanolamine and preferably triethanolamine. The alkanolamines are usually used in amounts of 0.1 to 3. preferably 0.5 to 1.5% by weight, based on the fatty acids.

Ethoxylation

The ethoxylation can be carried out in a manner known per se. The fatty acid and the catalyst are usually placed in a stirred autoclave. which is freed of traces of water by alternate evacuation and nitrogen purging before the reaction. The fatty acid is then reacted with the ethylene oxide in a molar ratio of 1: 0.5 to 1: 1.5 with ethylene oxide, which, after heating, is added in portions over a The lifter can be dosed into the pressure vessel. The fatty acids are preferably reacted with one mole of ethylene oxide. The ethoxylation can be carried out at temperatures in the range from 80 to 180, preferably 100 to 120, and autogenous pressures in the range from 1 to 5, preferably 2 to 3, bar. After the end of the reaction, it is advisable to stir at the reaction temperature for a certain time to complete the conversion (15-90min). The autoclave is then cooled, decompressed and, if desired, acids such as lactic acid or phosphoric acid are added to the product in order to neutralize the basic catalyst.

For the purposes of the present invention, preference is given to fatty acid polyethylene glycol esters of the formula (I) in which R ^{1 is} a linear alkylene radical having 12 to 18 carbon atoms and n is the number 1. Lauric acid ethoxylated with 1 mol of ethylene oxide is particularly suitable. Within the group of fatty acid polyethylene glycol esters, preference is given to those which have a melting point above 25 ° C., in particular above 40 ° C.

The fatty acid polyethylene glycol esters in the defoamer granules according to the invention are preferably in amounts of 3 to 30% by weight. in particular from 5 to 20% by weight, based on defoamer granules.

The defoamer granules according to the invention further contain silicones. For the purposes of the present invention, suitable silicones are conventional organopolysiloxanes. which can have a content of finely divided silica, which in turn can also be silanized. Such organopolysiloxanes are described, for example, in European patent application EP-Al-0 496 510. Polydiorganosiloxanes are particularly preferred. which are known from the prior art. Suitable polydiorganosiloxanes can have an almost linear chain and are characterized according to the following formula (III).

m wobei R unabhängig voneinander für einen Alkyl- oder einen Arylrest und m für Zahlen im Bereich von 40 bis 1500 stehen kann. Beispiele für geeignete Substituenten R sind Methyl, Ethyl. Propyl. Isobutyl. tert. Butyl und Phenyl.

m where R can independently represent an alkyl or an aryl radical and m can stand for numbers in the range from 40 to 1500. Examples of suitable substituents R are methyl, ethyl. Propyl. Isobutyl. tert. Butyl and phenyl.

However, compounds crosslinked via siloxane can also be used, as are known to the person skilled in the art under the name silicone resins.

As a rule, the polydiorganosiloxanes contain finely divided silica, which can also be silanized. Silicic acid-containing dimethylpolysiloxanes are particularly suitable for the purposes of the present invention.

The polydiorganosiloxanes advantageously have a Brookfield viscosity at 25 ° C. in the range from 5000 mPas to 30,000 mPas, in particular from 15,000 to 25,000 mPas.

The silicones are preferably used in the form of their aqueous emulsions for producing the defoamer granules according to the invention. As a rule, the aqueous emulsions are produced by stirring the silicones into the water provided. If desired, so-called thickeners can be used to increase the viscosity of the aqueous silicone emulsions. as they are known from the prior art. The thickeners can be inorganic and / or organic in nature. Nonionic cellulose ethers such as methyl cellulose are particularly preferred as thickeners. Ethyl cellulose and mixed ethers such as methyl hydroxyethyl cellulose.

Methyl hydroxypropyl cellulose. Methylhydroxybutyl cellulose and anionic carboxy cellulose types such as the carboxymethyl cellulose sodium salt (abbreviation CMC). Particularly suitable thickeners are mixtures of CMC to nonionic cellulose ethers in a weight ratio of 80:20 to 40:60. In particular 75:25 to 60:40.

In general, and especially when adding the thickener mixtures described, use concentrations of approximately 0.5 to 10, in particular from 2.0 to 6% by weight, are recommended - calculated as a thickener mixture and based on aqueous silicone emulsion. The content of silicones of the type described in the aqueous emulsions is advantageously in the range from 5 to 50% by weight. in particular from 15 to 35 wt .-% - calculated as silicones and based on aqueous silicone emulsion.

According to a further advantageous embodiment, the aqueous silicone solutions contain starch as a thickener, which is accessible from natural sources. for example from rice, potatoes. Corn and wheat. The starch is advantageously present in amounts of 0.1 to 50% by weight, based on the silicone emulsion, and in particular in a mixture with the already described thickener mixtures of sodium carboxymethyl cellulose and a nonionic cellulose ether in the amounts already mentioned.

To prepare the aqueous silicone emulsions, the procedure is expediently such that the thickeners which may be present are allowed to swell in water before the silicones are added. The silicones are expediently incorporated using effective stirring and mixing devices.

The defoamer granules according to the invention generally contain 0.5 to 30% by weight, preferably 5 to 20% by weight, of silicones of the type already described.

The defoamer granules according to the invention contain carrier materials for the silicones as a further constituent. According to the invention, all known inorganic and / or organic carrier materials can be used as carrier materials. Examples of typical inorganic carrier materials are alkali carbonates, aluminosilicates. water-soluble layered silicates, alkali silicates. Alkali sulfates, for example sodium sulfate and alkali phosphates. The alkali silicates are preferably a compound with a molar ratio of alkali oxide to SiO 2 of 1: 1.5 to 1: 3.5. The use of such silicates results in particularly good grain properties, in particular high abrasion stability and nevertheless high dissolution rate in water. The aluminosilicates referred to as carrier material include, in particular, the zeolites, for example zeolite NaA and NaX. The compounds referred to as water-soluble layered silicates include, for example, amorphous or crystalline water glass. Examples of organic carrier materials are film-forming polymers, for example polyvinyl alcohols. Polyvinyl pyrrolidones. Poly (meth) acrylates. Polycarboxylates. Cellulose derivatives and starch in question. Usable cellulose ethers are, in particular, alkali carboxymethyl cellulose. Methyl cellulose. Ethyl cellulose. Hydroxyethyl cellulose and so-called mixed cellulose ethers. such as methyl hydroxyethyl cellulose and methyl hydroxypropyl cellulose. as well as their mixtures. Particularly suitable mixtures are composed of sodium carboxymethyl cellulose and methyl cellulose, the carboxymethyl cellulose usually having a degree of substitution of 0.5 to 0.8 carboxymethyl groups per anhydroglucose unit and the methyl cellulose having a degree of substitution of 1.2 to 2 methyl groups per anhydroglucose unit. The mixtures preferably contain alkali carboxymethyl cellulose and nonionic cellulose ethers in weight ratios of from 80:20 to 40:60, in particular from 75:25 to 50:50. Such cellulose ether mixtures can be used in solid form or as aqueous solutions which are pre-swollen in the customary manner can. For the purposes of the invention, the native starch which is composed of amylose and amylopectin is particularly preferred as the carrier. Starch is referred to as native starch as it is available as an extract from natural sources, for example from rice, potatoes, corn and wheat. Native starch is a commercially available product and is therefore easily accessible.

Single or more of the above-mentioned compounds can be used as carrier materials, in particular selected from the group of alkali metal carbonates. Alkali sulfates. Alkali phosphates. Zeolites, water-soluble layered silicates, alkali silicates, polycarboxylates. Cellulose ether. Polyacrylate / polymethacrylate and starch. Mixtures of alkali carbonates, in particular sodium carbonate, are particularly suitable. Alkali silicates, especially sodium silicate. Alkali sulfates, especially sodium sulfate, zeolites, polycarboxylates, especially poly (meth) acrylate. and cellulose ether and native starch. The carrier materials can be composed as follows:

0 to 5% by weight cellulose ether 0 to 75% by weight native starch 0 to 30% by weight alkali silicate 0 to 75% by weight alkali sulfate 0 to 95% by weight alkali carbonate 0 to 95% by weight zeolites

0 to 5 wt .-% polycarboxylates. the sum must add up to 100% by weight.

The carrier materials are generally in amounts of 40 to 90% by weight. preferably in amounts of 45 to 75% by weight, based on defoamer granules.

If desired, the defoamer granules according to the invention can contain further water-insoluble wax-like defoamer substances. Compounds which have a melting point at atmospheric pressure above 25 ° C. (room temperature), preferably above 50 ° C. and in particular above 70 ° C. are understood as “wax-like”. The wax-like defoamer substances which may be present according to the invention are practically insoluble in water, ie at 20 ° C they have a solubility of less than 0.1% by weight in 100 g of water.

In principle, all wax-like defoamer substances known from the prior art can additionally be contained. Suitable waxy compounds are, for example, bisamides, fatty alcohols. Fatty acids, carboxylic acid esters of mono- and polyhydric alcohols as well as paraffin waxes or mixtures thereof.

Bisamides are suitable which are derived from saturated fatty acids with 12 to 22, preferably 14 to 18, carbon atoms and from alkylenediamines with 2 to 7 carbon atoms. Suitable fatty acids are lauric and myristic. Stearic, arachic and behenic acid and mixtures thereof, as are available from natural fats or hydrogenated oils, such as tallow or hydrogenated palm oil. Suitable diamines are, for example, ethylenediamine. 1,3-propylenediamine. Tetramethylene diamine, pentamethylene diamine. Hexamethylenediamine. p-phenylenediamine and toluenediamine. Preferred diamines are ethylenediamine and hexamethylenediamine. Bis-myristoyl-ethylenediamine are particularly preferred bisamides. Bis-palmitoyl-ethylenediamine. Bis-stcaroylethylenediamine and their mixtures and the corresponding derivatives of hexamethylenediamine.

Suitable carboxylic acid esters are derived from carboxylic acids with 12 to 28 carbon atoms. In particular, they are esters of behenic acid. Stearic acid. Oleic acid. Palmitic acid. Mvristic acid and / or lauric acid. The alcohol part of the carboxylic acid ester contains a mono- or polyhydric alcohol with 1 to 28 carbon atoms in the hydrocarbon chain. Examples of suitable alcohols are behenyl alcohol. Arachidyl alcohol. Coconut alcohol. 12-hydroxystearyl alcohol, oleyl alcohol and lauryl alcohol and ethylene glycol. Glycerin .. polyvinyl alcohol, sucrose. Erythritol. Pentaerythritol. Sorbitan and / or sorbitol. Preferred esters are those of ethylene glycol. Glycerin and sorbitan. wherein the acid part of the ester in particular from behenic acid, stearic acid. Oleic acid. Palmitic acid or myristic acid is selected.

Possible esters of polyhydric alcohols are, for example, xylitol monopalmitate, pentarythritol monostearate. Glycerol monostearate. Ethylene glycol monostearate and sorbitan monostearate. Sorbitan palmitate. Sorbitan monolaurate, sorbitan dilaurate, sorbitan distearate, sorbitan dibehenate. Sorbitan dioleate and mixed tallow alkyl sorbitan mono- and diesters. Glycerol esters which can be used are the mono-, di- or triesters of glycerol and the carboxylic acids mentioned, the mono- or diesters being preferred. Glycerol monostearate, glycerol monooleate, glycerol monopalmitate, glycerol monobehenate and glycerol distearate are examples of this.

Examples of suitable natural esters are beeswax, which mainly consists of the esters CH3 (CH ₂ ) 24COO (CH ₂ ) 27CH3 and CH ₃ (CH ₂ ) 26 ^{C00 C} 2) 25 ^CH 3, and carnauba wax. which is a mixture of carnauba acid alkyl esters. often in combination with small amounts of free carnauba acid. other long-chain acids, high molecular weight alcohols and hydrocarbons.

Suitable carboxylic acids as a further defoamer compound are, in particular, behenic acid. Stearic acid, oleic acid. Palmitic acid. Myristic acid and lauric acid and mixtures thereof, such as those obtainable from natural fats or optionally hardened oils, such as tallow or hydrogenated palm oil. Saturated fatty acids with 12 to 22, in particular 18 to 22, carbon atoms are preferred.

Suitable fatty alcohols as a further defoamer compound are the hydrogenated products of the fatty acids described. Suitable paraffin waxes as a further defoamer compound generally represent a complex mixture of substances without a sharp melting point. For characterization, its melting range is usually determined by differential thermal analysis (DTA), as described in "The Analyst" 87 (1962), 420, and / or its freezing point. This is the temperature at which the paraffin changes from the liquid to the solid state by slow cooling. Paraffins are completely liquid at room temperature, i.e. those with a solidification point below 25 ° C. not usable according to the invention. For example, the paraffin wax mixtures known from EP 309 931 of, for example, 26% by weight to 49% by weight of microcrystalline paraffin wax with a solidification point of 62 ° C. to 90 ° C., 20% by weight to 49% by weight hard paraffin can be used with a solidification point of 42 ° C to 56 ° C and 2 wt .-% to 25 wt .-% soft paraffin with a solidification point of 35 ° C to 40 ° C. Paraffins or paraffin mixtures which solidify in the range from 30 ° C. to 90 ° C. are preferably used. It should be noted that even paraffin wax mixtures that appear solid at room temperature can contain different proportions of liquid paraffin. In the paraffin waxes which can be used according to the invention, this liquid fraction is as low as possible and is preferably absent entirely. Particularly preferred paraffin wax mixtures at 30 ° C have a liquid fraction of less than 10% by weight, in particular from 2% by weight to 5% by weight, at 40 ° C a liquid fraction of less than 30% by weight, preferably of 5 % By weight to 25% by weight and in particular from 5% by weight to 15% by weight, at 60 ° C. a liquid fraction of 30% by weight to 60% by weight. in particular from 40% by weight to 55% by weight, at 80 ° C. a liquid fraction from 80% by weight to 100% by weight. and a liquid content of 100% by weight at 90 ° C. The temperature at which a liquid content of 100% by weight of the paraffin wax is reached is still below 85 ° C. in particularly preferred paraffin wax mixtures. especially at 75 ^C to 82 ° C.

As a rule, the further additional water-insoluble wax-like defoamers of the type described are in amounts of 0 to 30% by weight. preferably 5 to 25% by weight, based on defoamer granules.

Another object of the present invention relates to a process for the production of defoamer granules according to claim 1, characterized in that the silicones are sprayed in the form of aqueous emulsions onto a precursor made of carrier materials and fatty acid polyethylene glycol esters of the formula (I) with simultaneous drying and granulation.

The process according to the invention is based on spraying the silicones in the form of aqueous emulsions onto an admixed intermediate product from carrier materials and fatty acid polyethylene glycol esters and, if appropriate, further wax-like defoamer substances which are insoluble in water, and a defoamer granulate is obtained with simultaneous drying and granulation.

The way of preparing the aqueous emulsions of the silicones has already been described. The Voφrodukte can be produced in various ways, depending on whether the Voφrodukte be used as a solid or as an aqueous solution or aqueous slurry.

The procedure for the preparation of the product as an aqueous solution or as an aqueous slurry is generally as follows. that the carrier material is dissolved or slurried in water and the fatty acid polyethylene glycol esters and any wax-like defoamer substances present are dispersed therein. A water-soluble, non-surfactant dispersion stabilizer in the form of a water-swellable polymer can be added to the dispersion. Examples of these are the cellulose ethers mentioned. Homopolymers and copolymers of unsaturated carboxylic acids, such as acrylic acid. Maleic acid and copolymerizable vinyl compounds, such as vinyl ether. Acrylamide and ethylene. The addition of such compounds which act as dispersion stabilizers in the aqueous slurry is preferably not more than 5% by weight, in particular 1% by weight to 3% by weight, based on the resulting product. Depending on the type or solubility of the carrier materials, the water content of the slurry can be 30% by weight to 60% by weight.

Such aqueous solutions or slurries of the products are injected via nozzles for the production of the defoamer granules.

According to the present invention, however, it is preferred to use the products as a solid. Such solid products can be produced by various processes. According to a first procedure, the trasper material is placed in the Recel usually by spray drying an aqueous slurry of the carrier materials. The liquid or melted fatty acid polyethylene glycol esters and any additional melt-like further wax-like defoamer substances that may be present are applied to the spray-dried, granular carrier materials, for example by successive admixing, in particular in the form of a spray. The carrier material is preferably kept in motion by mixing elements or by fluidization in order to ensure a uniform loading of the carrier material. The spray mixers used for this can be operated continuously or discontinuously.

According to a second embodiment, the solid product is produced by spray drying an aqueous solution or slurry of carrier materials, fatty acid polyethylene glycol esters and any other wax-like defoamer substances that may be present. The starting point is aqueous solutions or slurries, which have already been described above in connection with the liquid products. Spray drying of the same can be carried out in a known manner in systems provided for this purpose, so-called spray towers, using hot drying gases conducted in cocurrent or countercurrent. Drying by drying gases carried in cocurrent with the spray material is preferred, since in particular in the case of paraffin-containing products, the loss of activity due to the potential hot air volatility of some constituents of the paraffin can be reduced to a minimum.

According to a third embodiment, solid products can be produced by simultaneous granulation and drying of an aqueous solution or slurry of carrier materials, fatty acid polyethylene glycol esters and any other wax-like defoamer substances which have already been described in connection with the liquid products. The simultaneous drying and granulation is preferably carried out in the fluidized bed by the SKET process, for example in accordance with European Patent EP-B-603 207 or by the fluidized bed process, which will be explained in more detail below.

According to the method according to the invention, the defoamer granules are produced by granulation and simultaneous drying. According to one method, the aqueous silicone emulsions are sprayed onto the admixed solid product. After a second Method, the aqueous silicone emulsions and the aqueous solutions or slurries of the products can be injected independently of one another.

The defoamer granules are preferably produced by spraying the silicone emulsion onto the solid product with simultaneous drying and granulation in a fluidized bed. According to one embodiment of this fluidized bed process, the granulation and simultaneous drying take place in a fluidized bed above a circular inflow floor provided with passage openings for the drying air, preferably according to the so-called SKET process. The aqueous silicone emulsions are introduced into the fluidized bed via one or more nozzles. Preferably, at the same time as the aqueous silicone emulsions, but separately from them, the solid product of carrier material fatty acid polyethylene glycol ester and possibly other wax-like defoamer substances are mixed in, preferably via an automatically controlled solids metering. The product streams of aqueous silicone emulsions and admixed Voφrodukt are controlled so that defoamer granules of the weight compositions already given result. In the fluidized bed, the aqueous silicone emulsion meets the admixed Voφrodukte with simultaneous evaporation of the water, resulting in dried to dried germs, which are coated with other introduced aqueous silicone emulsions or with the admixed Voφrodukte, granulated and again dried at the same time. The simultaneous drying and granulation takes place in the fluidized bed above a circular inflow floor provided with through-openings for the drying air, the product to be dried remaining stationary above the inflow floor during this drying phase, so that a build-up granulation takes place. Further details of the so-called SKET process can be found in the as yet unpublished German patent applications DE-P-197 50 424.8 and DE-P-197 56 681.2 and in European patent EP-B-0 603 207. A particular advantage of the process is. that the resulting defoamer granules are sighted or classified in terms of their grain size and thus also in terms of their weight from the incoming drying air, so that those granules which have reached the desired grain size or weight fall out of the fluidized bed onto the fluidized bed bottom in a discharge lock. Fluidized bed apparatuses which are preferably used have circular base plates (inflow base) with a diameter between 0.4 and 5 m. for example 1.2 m or 2.5 m. Perforated base plates, a Contiduφlatte (commercial product from Hein & Lehmann, Federal Republic of Germany) or perforated base plates can be used as the base plate, the holes (through openings) of which are covered by a grid with mesh sizes of less than 600 μm. The grid can be arranged inside or above the passage openings. However, the grid preferably lies directly below the passage openings of the inflow floor. This is advantageously realized in such a way that a metal gauze with the appropriate mesh size is sintered on. The metal gauze preferably consists of the same material as the inflow floor, in particular of stainless steel. The mesh size of said grid is preferably between 200 and 400 μm.

For the purposes of the invention, the process is preferably carried out at swirl air speeds between 1 and 8 m / s and in particular between 1.5 and 5.5 m / s. The granules are advantageously discharged via a size classification of the granules. This classification is preferably carried out by means of an opposite flow of drying air (classifier air) which is regulated in such a way that only particles of a certain particle size are removed from the fluidized bed and smaller particles are retained in the fluidized bed. In a preferred embodiment, the inflowing air is composed of the heated or unheated classifier air and the heated soil air. The soil air temperature is preferably between 80 and 400 ° C. The vortex air cools down through heat losses and through the heat of vaporization and is preferably about 5 cm above the base plate 60 to 120 ° C. preferably 65 to 90 and in particular 70 to 85 ° C. The air outlet temperature is preferably between 60 and 120 ° C, in particular below 80 ° C.

The residence time for the product to be dried, which remains stationary above the inflow floor, is preferably in the range from 5 to 60 minutes.

In the process preferably carried out in the SKET fluidized bed, it is necessary for a starting mass to be present at the start of the process. which serves as the initial carrier for the sprayed-in aqueous silicone emulsion. The admixed Voφrodukte or in particular the defoamer granules themselves, which are already at a previous procedure was obtained. In particular, defoamer granules which have been ground over a roller mill, preferably with a grain size in the range above 0.01 and below 0.2 mm, are used as starting mass and are fed in via a solids metering.

The defoamer granules obtained from the SKET fluidized bed are then preferably cooled in a separate fluidized bed and classified by means of a sieve into granules with particle sizes between 0.9 and 5 mm as good grain fraction, in granules over 5 mm as oversize fraction and in granules below 0.9 mm as undersize fraction. The granules of the undersize fraction are returned to the fluidized bed. The oversize grain fraction is ground, preferably in grain sizes above 0.01 and below 0.02 mm, and also returned to the fluidized bed.

According to a further embodiment of the process according to the invention, the defoamer granules can be produced by the so-called fluid bed process. Here, the aqueous silicone emulsion is sprayed onto the preferably solid product while simultaneously drying and granulating in a fluidized bed above a rectangular inflow surface provided with through-openings for the drying air, the product to be dried preferably being conveyed pneumatically continuously during the drying phase. Suitable apparatus for the fluidized bed process are, for example, on the market from Sulzer. Heinen, Gea or Babcock offered. The dimensions of the inflow floor are not critical. Preferred inflow floors are approximately 1 m wide and 3 m long. The inflowing air temperature is preferably between 80 ° C and 400 ° C. The inflowing amount of air is preferably in the range from 10,000 to 100,000 m ³ / h, in particular about 15,000 to 50,000 m ³ / h.

The residence time for the product to be dried, which is continuously conveyed, is preferably in the range from 1 to 30 minutes, in particular in the range from 1 to 15 minutes.

After the fluidized bed process, the aqueous silicone emulsions and the preferably solid product are introduced analogously to the SKET process already described, ie the silicone emulsions are passed through one or more nozzles and into the fluidized bed introduced and the solid Voφrodukt preferably via an automatically controlled solids metering. The product flows of aqueous silicone emulsions and admixed products are controlled analogously to the SKET fluidized bed. In the fluidized bed, the aqueous silicone emulsion meets the admixed Voφrodukte with simultaneous evaporation of the water, resulting in dried to dried germs, which are coated with other introduced aqueous silicone emulsions or with the admixed Voφrodukte, granulated and again dried at the same time.

According to a further embodiment of the process according to the invention for producing the defoamer granules, the simultaneous drying and granulation is carried out in a preferably horizontally arranged thin-film evaporator with rotating internals, such as that sold by the VRV company under the name "Flashdryer" , around a pipe which can be heated to different temperatures across several zones The product is metered in via one or more shafts which are provided with blades or shares of flies as rotating internals and sprayed with the aqueous silicone emulsion sprayed in via one or more nozzles and hurled against the heated wall, on which drying takes place in a thin layer, typically 1 to 10 mm thick. If the products are used as a slurry, metering is carried out by means of a pump. In the sense of the invention, it has proven to be advantageous Apply a temperature gradient from 170 ° C (product inlet) to 20 ° C (product discharge) at the thin film evaporator. For this purpose, for example, the first two zones of the evaporator can be heated to 160 ° C and the last can be cooled to 20 ° C. The thin film evaporator is operated at atmospheric pressure and gassed in countercurrent with air (throughput 50 to 150 m / h). The gas inlet temperature is usually 20 to 30 ° C, the outlet temperature 90 to 1 10 ° C. The throughput is of course dependent on the size of the dryer, but is typically 5 to 15 kg / h. It is advisable to heat the aqueous slurry of the product (slurry) to 40 to 60 ° C. during feeding. Furthermore, it is particularly advantageous to temper the aqueous silicone emulsions to 45 to 65 ° C. The product streams of aqueous silicone emulsions and metered Voφrodukt are controlled so that defoamer granules with the proportions already given result. After drying, it has also proven to be very advantageous to place the granules, which are still around 50 to 70 ° C., on a conveyor belt, preferably an oscillating shaft, and there quickly, ie within a dwell time of 20 to 60 s, with ambient air at temperatures of cool about 30 to 40 ° C. To further improve the resistance to unwanted water absorption, the granules can also be powdered by adding 0.5 to 2% by weight of silica.

For the purposes of the present invention, the defoamer granules are regarded as dried if the free water content is below 10% by weight, preferably from 0.1 to 2% by weight, based in each case on the finished granules.

The defoamer granules produced by the processes according to the invention are easy-flowing products which do not dust. They show a good defoaming effect and can be used in spray-dried, in granulated as well as in lumpy detergents, i.e. also in detergent tablets.

Another object of the present invention relates to the use of the defoamer granules according to the invention for the production of solid detergents.

The defoamer granules can be used in amounts of 0.2 to 7.0% by weight. preferably in amounts of 0.5 to 4.0% by weight, based on the detergent. Furthermore, the detergents can contain customary anionic, nonionic or cationic surfactants, as well as other customary constituents in customary amounts. Detergents such as tripolyphosphate or zeolite can be used as usual components. and optionally contain bleaches such as perborate or percarbonate in conventional amounts. The defoamer granules can easily be mixed in. Examples

Provision of a fatty acid polyglycol ester

200 g (1 mol) of technical lauric acid were placed in a 1 l stirred autoclave and 2 g of triethanolamine (corresponding to 1% by weight, based on lauric acid) were added. The autoclave was alternately evacuated and pressurized with nitrogen three times to remove traces of water that could lead to the formation of polyethylene glycol. After the reaction mixture had been charged with nitrogen for the last time, the autoclave was closed and heated to 100 ° C. and 44 g (1 mol) of ethylene oxide were added in portions at a maximum pressure of 5 bar. After completion of the reaction, recognizable by the fact that the pressure dropped again to a value of 1.2 bar and then remained constant, stirring was continued for 30 minutes and the reaction mixture was then cooled and let down. The basic catalyst was neutralized by adding an appropriate amount of lactic acid. The characteristics can be found in the following table, with higher homologues being added to 100% by weight.

I. Preparation of a Voφrodukt containing fatty acid polyethylene glycol ester

example 1

10,000 kg of an aqueous slurry consisting of 0.5% by weight cellulose ether, 5.0% by weight sodium silicate. 20.7% by weight sodium sulfate. 15.8% by weight sodium carbonate. 2.0% po lyacryl / methacrylate. 50% by weight of water and 6% by weight of lauric acid + 1 EO and 2% by weight of bisstearylethylenediamide were atomized with constant homogenization under a pressure of 40 bar in a spray tower and by means of hot, countercurrent combustion gases (temperature in the ring channel 250 ° C. , dried in the tower outlet 98 ° C).

Example 2

10,000 kg of an aqueous slurry consisting of 0.5% by weight of cellulose ether, 2.0% by weight of sodium silicate, 13% by weight of sodium sulfate, 23.5% by weight of zeolite. 2.0% by weight of polyacrylate / methacrylate, 50% by weight of water, 7% by weight of lauric acid + 1EO and 2% by weight of bisstearylethylenediamide were atomized with constant homogenization under a pressure of 40 bar in a spray tower and by means of hot, in Combustion gases of countercurrent flow (temperature in the ring duct 250 ° C. In the tower outlet 98 ° C) dried.

II. Preparation of the aqueous silicone emulsion

Example 3

2000 kg of an aqueous solution containing 3.7% by weight of a thickener mixture of sodium carboxymethyl cellulose and methyl cellulose in a weight ratio of 70:30) were left to swell at 25 ° C. for 4 hours. 30% by weight of> corn starch and 20% by weight of a polysiloxane defoamer (polydimethylsiloxane with microfine silanized silica) were added to this solution. A stable aqueous emulsion was obtained.

Example 4

2000 kg of an aqueous solution containing 3.7% by weight of a thickener mixture of sodium carboxymethyl cellulose and methyl cellulose in a weight ratio of 70:30) were allowed to swell at 25 ° C. for 4 hours. 20% by weight of a polysiloxane defoamer (polydimethylsiloxane with microfine silanized silica) were added to this solution. A stable aqueous emulsion was obtained. III. Granules in the fluidized bed

Example 5

In a fluidized bed apparatus (SKET system) with a circular fluidized bed, through which drying air flowed with approx. 20,000 m ³ air / h at a temperature of 100 ° C, 650 kg of the powdery product produced according to Example 2 were continuously passed over an hour Solid dosage metered and continuously sprayed onto this powdery Voφrodukt 350 kg per hour of the aqueous silicone emulsion prepared according to Example 3. The temperature in the fluidized bed above the fluidized bed was 65 ° C, the exhaust air 60 ° C. Granules with the following composition were obtained: 7% by weight of silicone. 2.1% by weight of cellulose ether, 10.3% by weight of corn starch, 3.2% by weight of sodium silicate. 21.2% by weight sodium sulfate. 38.1% by weight of zeolite, 3.3% by weight of polyacrylic / methacrylate and 11.5% by weight of lauric acid + 1 EO and 3.3% by weight of bis-stearylethylene diamide with a bulk density of 780 g / 1 and a grain size distribution of 0.2 to 1.2 mm. The product showed very good flow properties and had no dust content.

Example 6

According to Example 5, 650 kg per hour of the powdery product produced according to Example 1 were continuously fed into the fluidized bed apparatus (SKET system) at a drying air flow rate of approx. 20,000 πr air / h at a temperature of 100 ° C. by means of a solid dosage 350 kg per hour of the aqueous silicone emulsion prepared according to Example 4 were continuously sprayed onto this powdery product. The temperature in the fluidized bed above the fluidized bed was 65 ° C. the exhaust air is 60 ° C. Granules having the following composition were obtained: 7% by weight of silicone, 2.2% by weight of cellulose ether, 9.2% by weight of sodium silicate, 38.0% by weight of sodium sulfate, 29.1% by weight of sodium carbonate. 3.7% by weight polyacrylic / methacrylate, 1 1.0% by weight lauric acid + 1EO with a bulk density of 780 g / 1 and a particle size distribution of 0.2 to 1.2 mm. The product showed very good flow properties and had no dust content. IV. Application tests

The defoamer granules produced were mixed in an amount of 1.5% by weight by simply mixing them into a powdered universal detergent formulation with 8% by weight sodium alkylbenzenesulfonate, 10% by weight alkyl ethoxylate, 1.5% by weight soap, 10% by weight sodium carbonate, 20% by weight zeolite, 3% by weight sodium silicate, 20% by weight sodium perborate, 2% by weight tetraacetylethylenediamine (TAED), 0.5% by weight protease, balance incorporated on 100 wt .-% sodium sulfate and water. The detergents obtained had perfect foaming behavior both at 30 ° C. and at 40 ° C., 60 ° C. and 95 ° C.

Claims

Patent claims 1. defoamer granules for solid detergents containing silicones as defoamers and carrier materials, characterized in that they additionally contain fatty acid polyglycol esters of the formula (I), R ¹ COO (CH ₂ CH ₂ O) "H (I) in the R'CO for a linear or branched, aliphatic. saturated and / or unsaturated acyl radical having 6 to 22 carbon atoms and n represents numbers from 0.5 to 1.5, as defoamers. 2. Defoamer according to claim 1, characterized in that they contain fatty acid polyglycol esters of the formula (I) which have been prepared by ethoxylating fatty acids in the presence of alkanolamines. 3. defoamer granules according to claim 1 or 2, characterized in that they contain the fatty acid polyglycol esters in amounts of 3 to 30% by weight. preferably from 5 to 20% by weight. 4. defoamer granules according to claim 1 to 3, characterized in that they contain silicones of the formula (III),

m where R can independently represent an alkyl or an aryl radical and m can stand for numbers in the range from 40 to 1500. 5. defoamer granules according to one of claims 1 to 4, characterized in that they contain the silicones in amounts of 0.5 to 30 wt.%. preferably from 5 to 20% by weight. 6. defoamer granules according to one of claims 1 to 5, characterized in that they are alkali carbonates as carrier materials. Contain alkali sulfates, alkali phosphates, zeolites, alkali silicates, cellulose ethers, polycarboxylates and / or starch. 7. defoamer granules according to any one of claims 1 to 6, characterized in that they contain the carrier materials in amounts of 40 to 90 wt.%>, Preferably from 45 to 75 8. defoamer granules according to one of claims 1 to 7, characterized in that they additionally contain one or more water-insoluble wax-like defoamer substances selected from the group bisamides, fatty alcohols, fatty acids, carboxylic acid esters of mono- and polyhydric alcohols and paraffin waxes. 9. A process for the preparation of defoamer granules according to claim 1, characterized in that the silicones are sprayed in the form of aqueous emulsions onto a product of carrier materials and fatty acid polyglycol esters of the formula (I) with simultaneous drying and granulation. 10. The method according to claim 9, characterized in that silicones in the form of aqueous emulsions are continuously sprayed onto an admixed product of carrier materials and fatty acid polyglycol esters with simultaneous drying and granulation in a fluidized bed above a circular inflow floor provided with through-openings for the drying air. 11. The method according to claim 9, characterized in that silicones in the form of aqueous emulsions are sprayed onto an admixed product of carrier materials and fatty acid polyglycol esters with simultaneous drying and granulation in a fluidized bed above a rectangular inflow surface provided with through-openings for the drying air. 12. The method according to claim 9, characterized in that silicones in the form of aqueous emulsions are continuously sprayed onto an admixed product of carrier materials and fatty acid polyglycol esters with simultaneous drying and granulation in a thin-film evaporator with rotating internals. 13. Use of the defoamer granules according to claim 1 for the production of solid detergents.