EP0084657A1 - High foaming granular spray-dried washing agent with enhanced granulate stability and process for its fabrication - Google Patents

Abstract

The spray-dried, high-foaming detergent granules have a bulk density of no more than 450 g / l and are characterized by a high grain content of anionic surfactants due to a grain structure that is resistant to mechanical and weather-related influences. The detergent granules contain a surfactant component made from alkylbenzenesulfonate and fatty alcohol sulfate, a builder component made from sodium tripolyphosphate, finely crystalline sodium aluminum silicate (zeolite NaA) and sodium silicate. For the preparation, an aqueous slurry of the components is atomized in a spray device. The spray product obtained has a porous grain structure with an average grain size of 0.4-0.8 mm; the bulk density is preferably in the range of 250-400 g / l.

Description

The present invention relates to a detergent which has a high content of anionic surfactants and is characterized by a grain structure which is resistant to mechanical or unfavorable weather-related influences and is particularly suitable for washing by hand. Such agents are particularly suitable for use in developing countries, where mostly still under relatively simple conditions, i.e. is washed in the tub and without additional heat.

Means used in such cases must meet a number of special requirements. Since they are often repacked several times on the way from the manufacturer to the consumer and mostly shipped over long, often inadequate transport routes, increased demands must be placed on grain strength. The strength and perfect pourability should be maintained even under unfavorable climatic conditions, especially high air humidity. The detergents should not only be usable as stand-alone detergents, but should also be easily miscible and compatible with additives that are common and easily accessible in the respective consumer country, such as soap powder, bleach and the like led mixing process should be largely preserved and should be coordinated so that there are no segregation phenomena when the products are transported onward. On the other hand, despite its strength, the grain should disintegrate quickly when placed in cold water and dissolve after a short stirring.

An insufficiently informed, possibly literate consumers usually assess the effectiveness of a detergent after the foam has developed and then measure the amount used, which is why strong foaming agents are preferred in order to avoid overdosing and the resulting damage to the environment. Because of their low tendency to foam, nonionic surfactants are therefore less suitable for this purpose, especially since they have the property of degreasing the skin particularly sustainably and leaving an unpleasant feeling on the skin.

Detergents are already known which consist of compact granules and detergent substances incorporated therein, for example DE-OS 25 36 594 or DE-OS 27 42 683 (US Pat. No. 4,269,722). These are so-called carrier grains, which are produced by spray drying or targeted shaping without the addition of detergents and are subsequently subjected to liquid or melted nonionic surfactants. Such a procedure requires several process steps and is comparatively complex. Such a procedure is out of the question for salt-like anionic surfactants. In addition, such powders have a very compact grain structure and a comparatively high bulk density of over 500 g / l, mostly from 600 to 800 g / 1. Such dense, specifically heavy detergent granules dissolve very slowly in cold or moderately heated water. In contrast to loose spray powders, they immediately sink to the bottom in the wash liquor, which means that when used in the wash tub, a sediment is formed which only takes a long time long stirring completely dissolves. In addition, in such cases it is very difficult to assess whether the solution process has ended.

It is known that granular detergents can also be produced by spray drying, but in general, relatively soft, loose powders with a hollow spherical structure are produced when spray-drying conventional detergent compositions. Their bulk density is generally well below 500 g / l and is generally 200 to 350 g / l. Such powders, which are usually produced by spraying a water-containing detergent paste under high pressure by means of fixed nozzles, have an optimal solution behavior, but are relatively sensitive to mechanical stress. Older drying systems equipped with rotating spray elements deliver a firmer, but much finer grain with a high dust content. Such powders are very prone to clumping and have an unfavorable pouring behavior. Another problem is the spray drying of detergents with high, ie. H. more than 40% of the organic matter content at the high drying temperatures usually prevailing in the spray towers due to the risk of dust explosions and autoxidation processes which can lead to browning of the powder.

The present disadvantages are avoided by the present invention and the resulting task is solved.

• A) 35 bis 50 Gew.-% linearem Natriumalkylbenzolsulfonat mit 10 - 14 C-Atomen in der Alkylkette,
• B) 0 bis 15 Gew.-% Natriumfettalkoholsulfat mit 10 - 20 C-Atomen im Alkyl- bzw. Alkylenrest, wobei die Summe der Komponenten (A) und (B) 35 bis 50 Gew.-% beträgt,
• C) 5 bis 25 Gew.-% Natriumtripolyphosphat,
• D) 5 bis 25 Gew.-% feinkristallinem Natriumaluminiumsilikat der Formel :
  
  das gebundenes Wasser enthält, ein Calciumbindevermögen von wenigstens 100 mg CaO/g Aktivsubstanz (AS) und eine Teilchengröße von weniger als 25 Mikron aufweist, wobei wenigstens 80 Gew.-% der Teilchen eine Größe von weniger als 10 Mikron besitzen,
• E) 5 bis 20 Gew.-% Natriumsilikat der Zusammensetzung Na₂O : SiO₂ = 1 : 1,5 - 1 : 3,6,
• F) 0 bis 10 Gew.-% Natriumsulfat und/oder Natriumcarbonat und
• G) 8 bis 15 Gew.-% Wasser einschließlich des in den Komponenten (C) bis (F) gebundenen Wassers bzw. Kristallwassers,

wobei die Summe der Bestandteile (C) bis (G) 50 bis 65 Gew.-% beträgt.The invention relates to a high-foaming, granular, spray-dried detergent with increased grain stability, containing anionic surfactants, sodium tripolyphosphate, sodium aluminosilicate and sodium silicate by a bulk density of not more than 450 g / l and a content of

• A) 35 to 50% by weight of linear sodium alkylbenzenesulfonate with 10-14 carbon atoms in the alkyl chain,
• B) 0 to 15% by weight sodium fatty alcohol sulfate with 10-20 C atoms in the alkyl or alkylene radical, the sum of components (A) and (B) being 35 to 50% by weight,
• C) 5 to 25% by weight sodium tripolyphosphate,
• D) 5 to 25% by weight of finely crystalline sodium aluminum silicate of the formula:
  
  which contains bound water, has a calcium binding capacity of at least 100 mg CaO / g active substance (AS) and a particle size of less than 25 microns, at least 80% by weight of the particles having a size of less than 10 microns,
• E) 5 to 20% by weight sodium silicate of the composition Na ₂ O: SiO ₂ = 1: 1.5-1: 3.6,
• F) 0 to 10 wt .-% sodium sulfate and / or sodium carbonate and
• G) 8 to 15% by weight of water, including the water or water of crystallization bound in components (C) to (F),

wherein the sum of the components (C) to (G) is 50 to 65 wt .-%.

Preferred agents are those in which the sum of components (A) and (B) is 40 to 48% by weight and the sum of components (C) to (G) is 52 to 60% by weight.

Component (A) consists of linear sodium alkylbenzenesulfonate with 10 to 14 carbon atoms in the alkyl chain. A preferred example of this class of compounds is dodecylbenzenesulfonate.

Component (B) is sodium fatty alcohol sulfates, which are derived from saturated and / or monounsaturated primary fatty alcohols of natural or synthetic origin, and preferably 12 to 18

Have carbon atoms. Examples include coconut or; Tallow fatty alcohols, oleyl alcohol and synthetic alcohols obtainable by ethylene polymerization or oxosynthesis, the latter consisting of mixtures of linear and α-methyl-branched alcohols. Coconut fatty alcohol sulfates and similarly composed mixtures of saturated C ₁₂ -C ₁₈ fatty alcohol sulfates are particularly preferred.

The surfactants contained in the agents can consist exclusively of alkylbenzenesulfonates. However, a surfactant mixture is preferably used in which the amount of the fatty alcohol sulfates (component B) is such that the content of this component (B) in the detergents is up to 15% by weight, in particular 3-10% by weight. In this case, the amount of alkylbenzenesulfonates should be reduced accordingly, so that the total proportion of surfactants does not exceed 50% by weight and the proportion of alkylbenzenesulfonate, in particular 35 to 45% by weight.

The proportion of sodium tripolyphosphate (component C), based on anhydrous salt, is 5 to 25% by weight, preferably 8 to 20% by weight and in particular 10 to 17% by weight. The tripolyphosphate is usually present as hexahydrate, wherein the attributable water content of the component ^(G) is alculated ^train. Usually that is Tripolyphosphate in a mixture with small amounts of its hydrolysis products, ie diphosphate and orthophosphate, formed in the aqueous batch or in the course of spray drying, but their proportion is less than 20% by weight, preferably less than 15%, of the tripolyphosphate used for spray drying.

eingesetzt. Das in den Alumosilikaten gebundene Wasser wird ebenfalls dem Wasseranteil der Komponente (G) zugerechnet. Die Alumosilikate weisen eine Teilchengröße von weniger als 25 Mikron auf, wobei wenigstens 80 Gew.-% der Teilchen eine Größe von weniger als 10 Mikron besitzen. Sie weisen ein Calciumbindevermögen von wenigstens 100 mg CaO/g AS, vorzugsweise von 120 - 200 mg CaO/g AS auf, wobei das Calciumbindevermögen wie folgt bestimmt wird: 1 1 einer wäßrigen, 0,594 g CaC1₂ (= 300 mg CaO/1 = 30° dH) enthaltenden und mit verdünnter NaOH auf einen pH-Wert von 10 eingestellten Lösung wird mit 1 g Alumosilikat versetzt (auf AS bezogen). Dann wird die Suspension 15 min lang bei einer Temperatur von 22 °C (± 2 °C) kräftig gerührt. Nach Abfiltrieren des Alumosilikates bestimmt man die Resthärte x des Filtrates. Daraus errechnet sich das Calciumbindevermögen in mg CaO/g AS nach der Formel: (30 - x) . 10.Component (D) consists of fine-crystalline sodium aluminum silicates of the formula (I) given above which are capable of cation exchange. Preferably aluminosilicates of the formula

used. The water bound in the aluminosilicates is also included in the water content of component (G). The aluminosilicates have a particle size of less than 25 microns, with at least 80% by weight of the particles having a size of less than 10 microns. They have a calcium binding capacity of at least 100 mg CaO / g AS, preferably 120-200 mg CaO / g AS, the calcium binding capacity being determined as follows: 1 1 of an aqueous, 0.594 g CaC1 ₂ (= 300 mg CaO / 1 = 1 g of aluminosilicate (based on AS) is added to the solution containing 30 ° dH) and adjusted to pH 10 with dilute NaOH. Then the suspension is stirred vigorously for 15 minutes at a temperature of 22 ° C (± 2 ° C). After filtering off the aluminosilicate, the residual hardness x of the filtrate is determined. The calcium binding capacity in mg CaO / g AS is calculated from the formula: (30 - x). 10th

The proportion of aluminosilicates is 5 to 25% by weight, preferably 8 to 18% by weight, based on the anhydrous active substance. Particularly suitable aluminosilicates are synthetic, finely divided zeolites of the NaA type and NaX type and their mixtures.

^{Compounds of} the composition Na ₂ O: SiO ₂ = 1: 1.5 to 1: 3.6 are suitable as sodium silicates (component E), it also being possible to use mixtures of silicates of different compositions. The ratio is preferably 1: 2 to 1: 3.5. The sodium silicate content of the agents is 5 to 20% by weight, preferably 8 to 18% by weight and in particular 12 to 16% by weight. This information relates to anhydrous silicate.

As an optional component (F), the agents can contain sodium sulfate and / or sodium carbonate in amounts of up to 15% by weight, preferably not more than 10%. If component (F) consists of sodium sulfate, its proportion is generally 0.2 to 5% by weight. While components (C) to (E) are integrating components, which are important for both the grain properties and the cleaning effect, component (F) is ancillary and filler that does not significantly improve the product.

An essential component of the agent is the water content, which is a total of 5 to 12% by weight. Part of the water is comparatively firmly bound, for example as a component of the sodium aluminosilicate. The proportion of water which can be removed at a drying temperature of 140 ° C. is preferably 4 to 8% by weight. This proportion is such that, on the one hand, there are no oxidative changes and browning, in particular no dust explosions, during spray drying, but on the other hand the desired grain properties, such as high strength, good flowability and low tendency to form lumps even under unfavorable conditions and a sufficiently high dissolution rate result. If these limits are clearly undershot, the oxidative changes increase; if they are significantly exceeded, the grain properties deteriorate in the sense of reduced strength and free-flowing properties.

Other optional components that are present in small quantities, i.e. in individual cases up to about 2 wt .-% may be present, are organic chelating agents such as alkali metal salts of Aminoalkanpolyphosphonsäuren or hydroxyalkane phosphonic acids, such as aminotrimethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid and 1-hydroxyethane-1,1-diphosphonic acids of aminopolycarboxylic acids such as nitrilotriacetic acid or ethylenediaminetetraacetic acid as well as the higher homologues of the polyacids mentioned. Polymeric carboxylic acids, which may optionally contain hydroxy ether and / or carbonyl groups, can also be used as complexing agents. Other optional components are optical brighteners and anti-graying components, which include, in particular, cellulose ethers, such as carboxyl methyl or methyl cellulose. The sum of all organic constituents including constituents (A) and (B) must be such that their proportion does not substantially exceed 50% by weight.

Another object of the invention is a process for the preparation of the compositions, characterized in that the aqueous containing 30 to 45 wt .-% Auf Slurry of components (A) to (F) atomized in a spray device, the drying gases carried in cocurrent or countercurrent having an inlet temperature of 150 ° to 350 ° C and an outlet temperature of 65 ° to 95 ° C. The optional ingredients are also incorporated into the aqueous slurry and atomized. When preparing the aqueous slurry, it is advantageous to start from a stabilized suspension of sodium aluminosilicate, as can be obtained, for example, by the processes according to DE-OS 25 27 388, DE-OS 26 15 698 and DE-OS 27 04 310. In order to reduce the water content of the aqueous batch in the interest of lower energy consumption, dry or low-water aluminosilicates can also be added during further processing. Stabilized aluminosilicate suspensions of this type generally contain small amounts of stabilizing agents, for example nonionic surfactants or water-soluble polymers, which are incorporated into the end product in this way. The content of such suspension stabilizers in the agents according to the invention is, however, in view of the small amounts used in the suspensions, generally well below 1% by weight, usually below 0.5% by weight.

The remaining components of the composition can be distributed without problems in the aqueous slurry, and they can also be used as a dry substance or - if the total water balance allows this - also as an aqueous paste. The latter applies in many cases to the surfactants, in particular to the alkylbenzenesulfonate, which, for example can be incorporated into the aqueous batch as a sodium salt solution or as a free acid with the addition of the appropriate amount of sodium hydroxide.

Spraying is usually carried out under high pressure using nozzles. Air and combustion gases, which can be introduced directly into the tower, are the primary drying gases. The drying gas can be conducted in cocurrent or countercurrent to the spray product; preferably one uses the countercurrent principle and introduces the drying gas tangentially into the drying tower, so that a cyclone-like flow arises.

The spray product obtained has an average particle size of 0.4 to 0.8 mm, the proportion of particles with a particle size of less than 0.1 mm being less than 10% by weight, in particular less than 5% by weight and a grain size over 1.2 mm is less than 5% by weight, in particular not more than 2% by weight. Portions deviating from this grain spectrum are expediently sieved out and can be returned to the aqueous batch. The bulk density is in the range from 250 to 450 g / l, preferably from 300 to 400 g / l.

The spray-dried agents have a porous grain structure, which differs from conventional spray-dried heavy-duty or mild detergents by an increased grain strength, without the solution properties being impaired thereby. Despite high levels of organic matter, explosive or combustible dusts do not form during normal processing. They are easy to pour and do not tend to form lumps.

The agents can be used as detergents without further additives. But it can also be done retrospectively, i.e. to the finished product, in addition to other common detergent ingredients such as anionic and / or nonionic synthetic surfactants, soap, skeletal salts, e.g. Phosphates, washing alkalis, e.g. Soda, as well as bleach ,. such as per-compound or active chlorine carrier in granular or powdery form, or in another form directly before or during the application.

example 1

• ¹⁾ Die Mengenangabe bezieht sich auf Eingabemenge; der Erhaltungsgrad des Tripolyphosphats betrug 85 %.
• ²) Das Natriumalumosilikat vom NaA-Typ wies eine Korngröße von 0,1 bis 6 Mikron und ein Ca-Bindevermögen von 170 mg CaO/g AS auf.

A 50% by weight sodium alumosilicate suspension stabilized by means of ethoxylated tallow alcohol (5 EO groups) was admixed with the components listed below, the dodecylbenzenesulfonate being used as a 55% strength aqueous solution. The aqueous slurry containing 56.3% by weight of solids was heated to 75 ° C. and sprayed under a pressure of 20 bar through nozzles in a drying tower. The counter-current drying gas, consisting of air and combustion gases, had an inlet temperature of 180 ° C and an outlet temperature of 87 ° C. The spray product was composed as follows (% by weight):

• ¹⁾ The quantity specified relates to the input quantity; the degree of conservation of the tripolyphosphate was 85%.
• ² ) The NaA-type sodium aluminosilicate had a grain size of 0.1 to 6 microns and a Ca binding capacity of 170 mg CaO / g AS.

The grain size distribution determined by sieve analysis gave the following values (in% by weight):

The bulk weight was 320 g / l.

The determination carried out according to the GEIGY dust test resulted in an evaluation number for the flammability of BZ = 2 and a dust explosion ability (ignition with a filament at a concentration of 30 to 500 g / m) of St = 0, based on the following evaluation numbers:

The bulk behavior was checked with the so-called "package test". For this purpose, packages made of cardboard are evenly filled with the product up to the standard filling level, closed with a lid that can be attached and in a machine-driven vibrating machine under defined Conditions compressed by directional impacts, which results in a reproducible compression of the content. The package is opened and fastened in a device that allows it to be poured out at defined tilting angles. In addition, the packages can be shaken by means of a motorized impact device. The amount of powder flowing out is collected in a measuring cylinder. The following ratings are given, with the given degrees indicating the position of the package:

The consumer registers grades 1 to 3 as very good to good, grade 4 as satisfactory and grades 5 and 6 as poor or unsatisfactory. The determination of the powder gave the grade 4 immediately after the spray drying and the grade 3 after storage for 3 days.

In the clump test, which was also carried out, 15 ml of the powder were transferred into a hollow cylinder with an inner diameter of 25 mm and pressed for 30 minutes by means of a stamp which was additionally loaded with 500 g. The cylindrical compact pushed out under appropriate precautionary measures is then loaded in a vertical position under defined conditions until it breaks. The applied load (in grams) is a measure of the tendency to clump.

In the present case, the test value was 30 g with freshly sprayed powder and 0 g after storage for 3 days. In the case of commercial detergents, the last value is generally 10 to 60 g.

The determination of the dissolution behavior was carried out as follows.

In a beaker (volume 500 cm), 200 ml of tap water (15 ° dH) tempered to 30 ° C are pumped with the help of a motorized stirrer, which is equipped with 4 agitator blades bent downwards at an angle of 30 °, with a constant number of revolutions of 700 RPM stirred. The distance between the agitator blades and the bottom of the vessel is 2.5 cm. 1 g of the sample is carefully poured into the stirring cone7, avoiding lumps. After 90 seconds, the solution is poured through a tared sieve with a mesh size of 0.1 mm and a diameter of 7 cm and sucked off using a suction bottle. Remnants of substance remaining in the beaker are transferred onto the sieve using as little water as possible. The sieve is weighed back in air after a drying time of 24 hours.

In the present case, the residue formation was 1.6%.

• a) 5 g/l des Mittels
• b) 5 g/l des Mittels zuzüglich 1 g/l Natriumperborat
• c) 5 g/l zuzüglich 10 ml 10%ige Chlorbleichlauge durchgeführt wurden, ergaben ein einwandfreies, mit konventionellen Hochleistungswaschmitteln vergleichbares Waschergebnis.

The values given for the bulk behavior, the clump test and the solution behavior are mean values from 10 parallel tests. The results show that the agents according to the invention have favorable grain properties. Wash trials at 30 and 50 ° C in the tub on cotton and synthetic fabrics using

• a) 5 g / l of the agent
• b) 5 g / l of the agent plus 1 g / l sodium perborate
• c) 5 g / l plus 10 ml 10% chlorine bleach were carried out, gave a perfect washing result comparable to conventional high-performance detergents.

Examples 2 to 5

As described above, compositions of the following composition were produced (in the form of the Na salts):

The process parameters and product properties are summarized in Table 2.

Claims (11)

1. Highly foaming, granular, spray-dried detergent with increased grain stability, containing anionic surfactants, sodium tripolyphosphate, sodium aluminosilicate and sodium silicate, characterized by a bulk density of not more than 450 g / l and a content of A) 35 to 50% by weight of linear sodium alkylbenzenesulfonate with 10-14 carbon atoms in the alkyl chain, B) 0 to 15% by weight sodium fatty alcohol sulfate with 10-20 C atoms in the alkyl or alkenyl radical, the sum of components (A) and (B) being 35 to 50% by weight, C) 5 to 25% by weight sodium tripolyphosphate, D) 5 to 25% by weight of finely crystalline sodium aluminum silicate of the formula

which contains bound water, has a calcium binding capacity of at least 100 mg CaO / g active substance (AS) and a particle size of less than 25 microns, at least 80% by weight of the particles having a size of less than 10 microns, E) 5 to 20% by weight sodium silicate of the composition Na ₂ O: SiO ₂ = 1: 1.5-1: 3.6, F) 0 to 10 wt .-% sodium sulfate and / or sodium carbonate and G) 8 to 15% by weight of water, including the water of crystallization bound in components (C) to (F), the sum of components (C) to (G) being 50 to 65% by weight. 2. Composition according to claim 1, wherein the sum of components (A) and (B) is 40 to 48 wt .-% and the sum of components (C) to (G) is 52 to 60 wt .-%. 3. Composition according to claim 1 and 2, wherein the proportion of component (A) 35 to 45 wt .-% and the proportion of component (B) is 3 to 10 wt .-%. 4. Composition according to claim 1 to 3, wherein the proportion of component (C) is 8 to 20 wt .-%. 5. Composition according to claim 1 to 4, wherein the proportion of component (D) is 8 to 18 wt .-%. 6. Composition according to claim 1 to 5, wherein the proportion of component (E) is 8 to 18 wt .-%. 7. Composition according to claim 6, wherein the component (E) has the composition Na ₂ 0: SiO ₂ = 1: 2 to 1: 3.5. 8. Composition according to claim 1 to 7, wherein component (F) consists of sodium sulfate, the proportion of which is 0.2 to 5% by weight. 9. Composition according to claim 1 to 8, wherein the removable portion of the water at a drying temperature of 140 ° C is 4 to 8 wt .-%. 10. Composition according to claim 1-9, characterized by a bulk density of 300 to 400 g / l. 11. A process for the preparation of the agent according to claim 1 to 10, characterized in that a mixture of components (A) to (F) containing 30 to 45% by weight of water is atomized in a spray device, the flow being in cocurrent or countercurrent led drying gases have an inlet temperature of 150 ° to 350 ° C and an outlet temperature of 65 ° to 95 ° C.