EP0859048A2 - Process for making surfactant granules - Google Patents

Abstract

A method for the preparation of wash- and cleaning-active surfactant granules with bulk weights greater than 600 g/l by granulating surfactant formulations, comprises: (1) solutions of (A) alkyl benzene sulphonate (ABS) and/or alkyl polyglycoside (APG) surfactants and (B) carrier materials chosen from polycarboxylates or inorganic salts (preferably amorphous silicates) in a non-surfactant solvent are simultaneously nebulised through the same nozzle ; and (2) the nebulised solutions are dried in standard dryers, preferably in fluidised bed dryers or a ring mixer dryer with a high rpm, during which the two liquids separate to leave the strongly hygroscopic and tacky active substance at least partially surrounded by the non-tacky carrier material. Also claimed are washing or cleaning agents with bulk weights greater than 600 g/l which contain either (i) more than 60 wt.% ABS, (ii) more than 60 (70) wt.% APG or (iii) at least 10 (20) wt.% end product of the above method.

Description

The invention relates to a process for the production of concentrated surfactant granules Active substance content of more than 45 wt .-%, based on the granules, which a low hygroscopicity, a significantly improved silage capacity and an increased Have bulk density.

The economical production of light colored surfactant powders. especially of Anionic surfactants based on fatty alcohol sulfates (FAS) and alkylbenzenesulfonates (ABS), is today a reliable state of technical knowledge. The corresponding surfactant salts are obtained in aqueous preparation forms, with water contents in the range adjustable from about 20 to 80% by weight and in particular from about 35 to 60% by weight are. Products of this type have a paste-like to cutting ability at room temperature Condition, whereby at room temperature the flow and pumpability of such Pastes are restricted or lost in the range of approximately 50% by weight of active substance, so that in the storage and processing of such pastes, in particular when incorporated into mixtures, for example in detergents and cleaning agents, considerable problems arise. Accordingly, there is an old need for detergent surfactants to be made available in a dry, in particular free-flowing form. Indeed it also succeeds in using conventional drying technology, especially in Spray tower to obtain free-flowing surfactant powder, for example free-flowing FAS powder. Here, however, there are serious restrictions, in particular the economy question the industrial use of the powders obtained in this way. Surfactant powders dried over the tower often show very low bulk densities, see above that unprofitable conditions occur in the packaging and distribution of these powders or such powders are compacted into heavier granules by granulation have to. But even in the manufacture of the tower powders, safety-related Consider such a restrictive way of tower drying make practical difficulties arise here. For example, caking in the tower occur that lead to brown discolouration of the powder.

Comparable and / or other difficulties arise when converting aqueous, especially pasty preparation forms of numerous other washing and cleaning active Surfactant compounds to storage-stable solids. For example for the production of light colored wash and cleaning active alkyl glycosides within the scope of Synthesis of a final bleach, for example with aqueous hydrogen peroxide required so that here too today's technology leads to the aqueous paste form. Such aqueous alkyl glycoside pastes (APG pastes) are e.g. by hydrolysis or microbial Contamination is more at risk than corresponding dry products. Also Drying according to previously common technologies presents considerable difficulties here. Finally, the drying of an aqueous paste of the alkali salts can also be carried out detergent soaps and / or ABS pastes have significant problems bring.

Granulation is an alternative to spray drying surfactant pastes describes EP-B-0 603 207 (Henkel) a process for the production of washing and cleaning active Surfactant granules with a bulk density above 500 g / l by simultaneous Granulation and drying in all devices where there is granulation can be carried out with simultaneous drying. Here, a surfactant preparation form, which is a non-surfactant liquid component (usually water) has, if desired granulated with the addition of a solid component and dried at the same time. For the ability to ensilage and the distribution of the active substance in the resulting Grain, especially for extractability of the surfactant from the uncrushed or crushed product with the help of non-aqueous solvents that do not destroy the grain, nothing is carried out in the registration. The simultaneous spraying also provides of active substance and carrier component solution through one and the same nozzle here is a possible but not a mandatory process parameter.

The object of the invention was to provide a method for producing heavy, free-flowing, to provide highly concentrated surfactant granules with bulk densities above 600 g / l, the granules obtained have advantages in terms of ensiling ability and Show hygroscopicity.

a) Alkylbenzolsulfonat- und/oder Alkylpolyglycosid-Tensiden und

b) Trägermaterialien, ausgewählt aus der Gruppe der Polycarboxylate und der anorganischen Salze, insbesondere der amorphen Silikate,

in einem nicht-tensidischen Lösungsmittel gleichzeitig durch ein- und dieselbe Düse verdüst und in herkömmlichen Trocknern, vorzugsweise in der Wirbelschicht oder einem Ringmischtrockner mit hohen Drehzahlen, trocknet, wobei während der Trocknung eine Trennung zwischen den beiden Flüssigkeiten stattfindet, so daß die stark hygroskopische, klebrige Aktivsubstanz von der nicht klebrigen Trägersubstanz mindestens teilweise eingeschlossen wird.The invention accordingly relates to a process for the production of detergent granules with active detergent and cleaning activity with bulk densities above 600 g / l by granulating a surfactant preparation form, characterized in that solutions of

a) Alkylbenzenesulfonate and / or alkylpolyglycoside surfactants and

b) carrier materials selected from the group of the polycarboxylates and the inorganic salts, in particular the amorphous silicates,

atomized in a non-surfactant solvent simultaneously through one and the same nozzle and dried in conventional dryers, preferably in the fluidized bed or in a ring mixer dryer at high speeds, with a separation between the two liquids taking place during the drying process, so that the highly hygroscopic, sticky active substance is at least partially enclosed by the non-sticky carrier substance.

The process according to the invention has the advantage that the resulting grain is conditional due to the inclusion of surfactant phases in phases of the carrier material, an increased mechanical Stability and an extremely reduced water absorption during storage. The granules obtained by the process according to the invention are accordingly very easy to pour and ensilage and stick together due to their low tendency to absorb water. With separate injection of active substance and The product is a carrier paste in the granulating unit even at low surfactant concentrations sticky and cakes on drying, adding the products are hygroscopic and stick in the course of heavy water absorption.

The solutions of the active substance and the carrier substance are carried out according to the invention one and the same nozzle atomized. Here, the solutions can only be in the nozzle with each other mixed, i.e. supplied to the nozzle via separate storage containers and feed lines but also a mixture of both solutions from a single storage container can be injected through a nozzle.

The non-surfactant solvent, which may contain one or more components, has a boiling point or boiling range preferably below normal pressure 250 ° C and especially below 200 ° C. With particular advantage, it contains components which boil between 60 and 180 ° C at normal pressure. As if present Organic constituents of the non-surfactant solvent are preferably mono- and / or polyfunctional alcohols, for example methanol, ethanol, propanol, Isopropanol, butanol, secondary and tertiary butanol, pentanol, ethylene glycol, 1,2-propanediol, Glycerin or mixtures of these are used. The is preferably Proportion of monofunctional and / or polyfunctional solvents used as non-surfactant solvents Alcohols 0.5 to 10 wt .-% and in particular 45 to 60 wt .-%, each based on the surfactant preparation form.

In particular, however, it is preferred as an inorganic component of the non-surfactant Solvent water, optionally together with organic components such as ethanol, 1,2-propanediol or glycerin. The share is of the water preferably 25 to 80 wt .-%, based on the total amount of non-surfactant solvent. The solutions of surfactants and carrier materials in Non-surfactant solvents can be used in a wide range of concentrations are taken into account, with only a viscosity that is still suitable for atomization got to. Based on the total solution to be sprayed, the proportion of the non-surfactant is Solvent 30 to 70 wt .-% and in particular 45 to 60 wt .-%.

Either alkylbenzenesulfonates (ABS) or alkylpolyglycosides (APG) or mixtures of these are used as surfactants. Advantageously used alkylbenzenesulfonates have a chain length of 9 to 13 carbon atoms, but almost pure C ₁₂ -alkylbenzenesulfonate can also be used with preference. The alkyl or alkenylglycosides (APG) have the general formula RO- (G) _x , in which R is one primary, straight-chain or in the 2-position methyl branched aliphatic radical having 8 to 22, preferably 12 to 18 carbon atoms, G is a symbol which represents a glucose unit having 5 or 6 carbon atoms, and the degree of oligomerization x between 1 and 10, preferably between 1 and 2 and in particular is significantly smaller than 1.4.

Without impairing the process advantages according to the invention, in addition to the ABS and / or APG surfactants also other anionic, nonionic, cationic or amphoteric surfactants can be used in combination with the former. While the process is mainly used to manufacture ABS and / or APG compounds suitable are additions of up to 20% by weight of other surfactants, based on the total amount of surfactant, possible without losing the advantages of the method according to the invention.

The carrier materials used in the process according to the invention can be inorganic and / or organic in nature. In a preferred embodiment, they consist of amorphous alkali silicates of the formula (SiO ₂ ) _m (M ₂ O) _n1 (so-called water glasses) and / or crystalline layered silicates of the formula (SiO ₂ ) _m ((M ₂ O) _n2 (H ₂ O ) _x , where M is lithium, sodium or potassium, m and n1 are integers or fractional numbers greater than 0, n2 is 1 and x is 0 or integers from 1 to 20. As a carrier solution for the granulation according to the process of the invention Solutions of water glasses in which M stands for sodium and x for 0 and whose modulus, ie whose m: n ratio is 1.9 to 4, preferably 1.9 to 2.5, have proven particularly useful Solids contents of 1 to 80% by weight, preferably 30 to 60% by weight.

As further carrier materials, alone or in combination with the silicates in the form solutions, inorganic salts or organic polycarboxylates are used into consideration. In particular, sodium carbonate is among the inorganic salts preferred, while as polycarboxylates preferably citric acid / citrates and / or Acrylic acid / maleic acid copolymers are used.

The detergent granules, which are active in washing and cleaning, have, based on the finished granulate, Carrier material contents of 10 to 50 wt .-%. Because highly concentrated surfactant granules Preferred for economic reasons are carrier material contents from below 40, in particular below 30% by weight, is preferred. In addition to the so-called over-dried Water glasses can also be found in preferred embodiments of the invention Sodium carbonate, acrylic acid / maleic acid copolymers and trisodium citrate as carrier materials Use. Mixtures of the carrier substances are also preferred, in particular Carbonate / silicate mixtures as well as citrate / silicate mixtures.

The surfactant preparation form is granulated and dried, according to the invention Process granulate particles are obtained in which the active substance is partially enclosed by the carrier. Under drying, this becomes partially or completely remove the non-surfactant solvent. The non-surfactant solvent is preferably removed almost completely.

The preparation of the surfactant granules can be done in all devices take place in which a granulation under drying conditions can be carried out. Examples include heated mixers and granulators, especially high-speed ring mix dryers such as Turbo dryer® granulators (Device from Vomm, Italy). In a preferred embodiment, the Invention, however, that the combination of the two process steps in a batch or continuously running fluidized bed is carried out. It is special preferred to carry out the process continuously in the fluidized bed. Here the surfactant preparation form is introduced into the fluidized bed from a common nozzle. The mixture of the two liquid to pasty components of the surfactant preparation form can be done beforehand or only in the nozzle. Prefers Fluid bed apparatuses used have base plates with dimensions of at least 0.4 m. In particular, fluidized bed apparatuses which have a base plate are preferred have a diameter between 0.4 and 5 m, for example 1.2 m or 2.5 m. However, fluidized bed apparatuses are also suitable which have a base plate with a have a diameter greater than 5 m. A perforated base plate is preferably used as the base plate or a Conidur plate (commercial product from Hein & Lehmann, Federal Republic Germany). The method according to the invention is preferred at vortex air speeds between 1 and 8 m / s and in particular between 1.5 and 5.5 m / s performed. The granules are discharged from the fluidized bed advantageously via a size classification of the granules. This classification can for example with a screening device or through an opposed air flow (Classifier air), which is regulated so that only particles above a certain particle size removed from the fluidized bed and smaller particles retained in the fluidized bed will. In a preferred embodiment, the inflowing settles Air from the heated or unheated classifier air and the heated soil air together. The soil air temperature is preferably between 80 and 400 ° C, in particular between 90 and 350 ° C. The vortex air cools down due to heat loss and by the heat of vaporization of the components of the non-surfactant solvent from. In a particularly preferred embodiment, the temperature of the fluidizing air is about 5 cm above the base plate 60 to 120 ° C, preferably 65 to 90 ° C and especially 70 to 85 ° C. The air outlet temperature is preferably between 60 and 120 ° C, especially below 100 ° C and with particular advantage between 70 and 85 ° C. In the method carried out according to the invention, the mixture of the two Solutions that together form the surfactant preparation form through a nozzle into the Fluidized bed blown in, in which there are no additional solids as starting mass. The dried surfactant preparation form acts in the continuously working fluidized bed as carrier or seed material. Here the evaporate Parts or all of the non-surfactant solvent, the dried-on to dry germs with additional amounts of surfactant preparation are encased in such a way that the carrier substance is the active substance envelops. This special structure of the granulate, which can only be achieved by simultaneous injection Obtain active substance and carrier material solution through one and the same nozzle is the result of the evaporating non-surfactant solvent in the evaporation process Backing material from the freshly condensed layer on the grain contributes and deposits on the surface of the grain upon evaporation.

In the granulation according to the invention, especially when alkylbenzenesulfonates used as surfactants to maintain the vortex granulation process continuously add a powdering agent, preferably zeolite or sodium carbonate, into the Fluidized bed are introduced. These powdering agents reduce the amount of granulation the stickiness of the moist granules and thus promote turbulence and drying to the desired product. For the production of granules According to the method according to the invention, this variant can be advantageous is, however, not absolutely necessary to carry out the invention.

In this way, the process according to the invention results in surfactant granules which dissolve easily in cold water without being hygroscopic. The granules have high mechanical stability and thus excellent flow and silage properties. Leave with organic solvents that do not destroy the grain structure only small amounts of active substance dissolve from the uncrushed granules, while most of the active substance can be extracted from the ground granules is.

The washing and cleaning active produced by the inventive method Surfactant granules have bulk densities above 600 g / l. They are ideal as components suitable for the production of detergents and cleaning agents, preferred Detergents and cleaning agents which are produced by the process according to the invention detergent granules active in washing and cleaning in amounts of more than 10% by weight, in particular in amounts above 20 wt .-%, based on the total washing and Detergent included. For processing in detergents with a high bulk density or for other special applications is a bulk density according to the invention Process produced washing and cleaning active surfactant granules above of 700 g / l, in particular above 800 g / l, is preferred.

The process according to the invention can advantageously be active in washing and cleaning Surfactant granules are produced, the total surfactant content, based on the total granulate is more than 40% by weight. Surfactant contents above 50% by weight and in particular above 60% by weight are preferred. In the preparation of of alkylbenzenesulfonate (ABS) and alkylpolyglycoside (APG) granules are ABS contents above 40% by weight, preferably above 50% by weight and in particular above 60 wt .-%, based on the granules, preferred, while APG contents preferably above 50% by weight, preferably above 60% by weight and in particular above 70% by weight, based on the granules.

The process is suitable for the production of highly concentrated surfactant granules and has particular advantages if the surfactants to be processed are sticky per se Are natural, as is the case with alkylbenzenesulfonates and alkylpolyglycosides. Of course, other surfactants that have no adhesive properties can also be used or glue much less, can also be used. However, it is preferred that the proportion of other surfactants is 20% by weight, based on the total surfactant content, does not exceed in the granules according to the invention.

Examples

Compounds of the following composition were obtained by simultaneous spraying of aqueous surfactant and carrier material solutions through a multi-channel nozzle into a fluidized bed dryer: Composition [% by weight]: E1 E2 E3 E4 E5 E6 E7 E8 SECTION 45 - - - 60 50 - 61 APG - 67 80 50 - - 62 - silicate 21 22 17.5 10th 13 15 - - Sokalan CP5® - - - - - - 33 - Sodium citrate - - - - - - - 14 sodium 28 - - 35 - - - - Zeolite - - - - 22 30th - 20th water 6 11 2.5 5 5 5 5 5 Bulk density [g / l] 632 641 612 651 702 734 611 633 Sokalan CP5 ® is an acrylic acid-maleic acid copolymer from BASF

To prove that large parts of the surfactant are enclosed by the carrier material, a sample of E2 was examined by liquid chromatography. Straight from production extracted E2 had an active substance content of 23 when extracted with methanol % By weight, while a sample of the same batch after mortars with otherwise the same The procedure gave an active substance content of 65% by weight.

The solubilities of E1 and E2 were determined by adding 5 g each of the agent to a 1 liter vessel containing 500 ml of demineralized water which was stirred by a propeller stirrer at 900 rpm. The conductivity was detected via a conductivity measuring cell and recorded on a recorder. The measurement was carried out until no increase was ascertainable. The time to reach the conductivity of the agent was set to 100%, the corresponding other dissolving times were calculated. Solubility test E1 E2 95% solved [min] 2.59 2.57 90% solved [min] 2.27 2.25 80% solved [min] 1.45 1.48 Residue after 1.5 min [% by weight] 2nd 5 Residue after 5 min [% by weight] 0 0

All compounds E1 to E8 produced according to the invention can be stored in the air without sticking or losing their free-flowing properties. A comparison test between E5 and a commercially available comparable ABS compound with a bulk density of 400 g / l and an active substance content of 85% by weight gave the following values after 8 hours of storage (55% relative luminous humidity): Hygroscopicity (8-hour storage trial) E5 comparison Water absorption [% by weight] 5 20th Remarks free-flowing Bonding

The ABS / APG compounds produced according to the invention are ideal additives suitable for detergents because they give the detergents improved solubility.

The solutions of the active substance and the carrier were not the same Nozzle, but sprayed through two separate nozzles, so no free-flowing granules obtained with high bulk density. Rather, such mixtures have already stuck together in the mixer to viscous to pasty masses that could not be dried further.

Claims (12)

Process for the production of detergent-active granules with a bulk density above 600 g / l by granulation of a surfactant preparation form, characterized in that solutions of a) Alkylbenzenesulfonate and / or alkylpolyglycoside surfactants and b) carrier materials selected from the group of the polycarboxylates and the inorganic salts, in particular the amorphous silicates, atomized in a non-surfactant solvent simultaneously through one and the same nozzle and dried in conventional dryers, preferably in the fluidized bed or in a ring mixer dryer at high speeds, with a separation between the two liquids taking place during the drying process, so that the highly hygroscopic, sticky active substance is at least partially enclosed by the non-sticky carrier substance. A method according to claim 1, characterized in that as a non-surfactant solvent mono and / or polyfunctional alcohols, preferably in amounts of 0.5 to 10 wt .-%, based on the total solution to be atomized, are used. Method according to one of claims 1 or 2, characterized in that as non-surfactant solvent water, preferably in amounts of 25 to 80 % By weight, based on the total amount of the non-surfactant solvent becomes. Method according to one of claims 1 to 3, characterized in that for maintenance the powder granulation process continuously a powdering agent, preferably zeolite or sodium carbonate, introduced into the fluidized bed becomes. Method according to one of claims 1 to 4, characterized in that as the carrier material a silicate / citrate mixture is used. Method according to one of claims 1 to 5, characterized in that the alkylbenzenesulfonate (ABS) content above the washing and cleaning active surfactant granules of 40% by weight, preferably above 50% by weight and in particular is above 60% by weight, based on the granules. Method according to one of claims 1 to 6, characterized in that the alkyl polyglycoside (APG) content above the washing and cleaning active surfactant granules of 50% by weight, preferably above 60% by weight and in particular is above 70% by weight, based on the granules. Method according to one of claims 1 to 7, characterized in that the total surfactant content the detergent and cleaning active granules above 40 % By weight, preferably above 50% by weight and in particular above 60 % By weight, based on the granules. Method according to one of claims 1 to 8, characterized in that the detergent granules active in washing and cleaning up to 20% by weight of other surfactants, based on the amount of ABS and APG included. Detergent and cleaning active granules with a bulk density above 600 g / l, containing more than 60 wt .-% alkylbenzenesulfonate. Detergent and cleaning active granules with a bulk density above 600 g / l, containing more than 60% by weight, preferably more than 70% by weight, of alkyl polyglycoside. Washing and cleaning agents containing at least 10% by weight, preferably at least 20% by weight of a process end product according to claims 1 to 9.