DE19702845A1 - Process for the preparation of 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 bulk have weight.

The economical production of light colored surfactant powders. especially of anion surfactants based on fatty alcohol sulfates (FAS) and alkylbenzenesulfonates (ABS) The current state of technical knowledge. The corresponding surfactant salts fall thereby in aqueous preparation forms, with water contents in the range of about 20 up to 80 wt .-% and in particular from about 35 to 60 wt .-% are adjustable. Products of this type have a paste-like to cutting quality at room temperature, at room temperature the flow and pumpability of such pastes is already in the range is restricted or lost by about 50% by weight of active substance, so that the Storage and further processing of such pastes, especially during their incorporation in mixtures, for example in detergents and cleaning agents, considerable problems arise. Accordingly, it is an old need to use detergent surfactants in dry, to provide in particular free-flowing form. In fact, it also works  through the conventional drying technology, especially in the spray tower, free-flowing To obtain surfactant powder, for example free-flowing FAS powder. Here, however, show up serious restrictions, in particular the economics of large-scale Question the use of the powder obtained in this way. Ten dried over the tower Sidpulver often show very low bulk weights, so that the packaging and Distribution of these powders can lead to unprofitable conditions or such powders through Granu must be compacted into heavier granules. But also with the Manufacturing the tower powders can be such a strong safety concern restrictive driving style of tower drying require that here practical Difficulties arise. So z. B. caking occurs in the tower, which brew too lead to discolouration of the powder.

Comparable and / or other difficulties arise when converting watery to special pasty preparation forms for numerous other washing and cleaning products active surfactant compounds to storage-stable solids. For example, for Obtaining light colored wash and cleaning active alkyl glycosides in the context of the syn these a final bleaching, for example with aqueous hydrogen peroxide Necessary, so that today's technology leads to an aqueous paste form. Such aqueous alkyl glycoside pastes (APG pastes) are e.g. B. by hydrolysis or microbial Contamination is more at risk than corresponding dry products. Here too drying using conventional technologies has considerable difficulties. Finally, the drying of an aqueous paste of the alkali salts can also be carried out detergent soaps and / or ABS pastes pose significant problems.

Granulation is an alternative to spray drying surfactant pastes EP-B-0 603 207 (Henkel) describes a process for producing wash and clean gungsactive surfactant granules with a bulk density above 500 g / l by simultaneous ge granulation and drying in all devices in which a granulation under simultaneous drying can take place. Here is a surfactant preparation form, the has a non-surfactant liquid component (usually water) if granulated with the addition of a solid component and dried at the same time.  

The ability to ensilage and the distribution of the active substance in the resulting grain, in particular the extractability of the surfactant from the non-shredded or shredded product with the help of non-aqueous solvents that do not destroy the grain, in the Registration failed. Also represents the simultaneous spraying of active substance and Carrier component solution through one and the same nozzle here a possible, but are not a mandatory process parameter.

The object of the invention was to provide a method for producing heavy, trickle capable, highly concentrated surfactant granules with bulk weights above 600 g / l to deliver, the granules obtained advantages in terms of silage and Show hygroscopicity.

The invention accordingly relates to a process for the preparation of detergent granules having a washing 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 polycarboxylates and inorganic salts, especially amorphous silicates,

atomized in one non-surfactant solvent simultaneously through one and the same nozzle and in conventional dryers, preferably in the fluidized bed or in one Ring mixer dryer with high speeds, dries, during the drying a Separation between the two liquids takes place, so that the highly hygroscopic, sticky active substance at least partially absorbed by the non-sticky carrier substance is closed.

The process according to the invention has the advantage that the resulting grain is conditional by the inclusion of surfactant phases in phases of the carrier material an increased me mechanical stability and 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 even due to their open storage not a slight tendency to absorb water. With separate injection of active substance and The product is a carrier paste in the pelletizing unit even at low surfactant concentrations sticky and cakes on drying, with the products additionally 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. who supplied via separate storage containers and feed lines to the nozzle but also a mixture of both solutions from a single storage container 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 an existing or ganic component of the non-surfactant solvent are preferred monofunctional and / or polyfunctional alcohols, for example methanol, ethanol, propanol, isopro panol, butanol, secondary and tertiary butanol, pentanol, ethylene glycol, 1,2-propanediol, Glycerin or mixtures of these are used. The proportion of the is preferably non-surfactant solvent used mono- and / or polyfunctional alcohols 0.5 to 10% by weight and in particular 45 to 60% by weight, in each case based on the tenside additive 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 Et hanol, 1,2-propanediol or glycerin. The proportion of water preferably 25 to 80 wt .-%, based on the total amount of the non-surfactant Solvent. The solutions of surfactants and carrier materials in non-surfactant Solvents can be used in a wide range of concentrations, whereby single  Lich a suitable viscosity for atomization must be observed. Related to the total solution to be sprayed is the proportion of the non-surfactant solution means 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. Alkylbenzbisulfonates used advantageously 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 alkenyl glycosides (APG) have the general formula RO- (G) _x , in which R denotes a primary, straight-chain or aliphatic radical which is methyl-branched in the 2-position and has 8 to 22, preferably 12 to 18, carbon atoms, G is a symbol which stands for a glucose unit with 5 or 6 carbon atoms, and the degree of oligomerization x is between 1 and 10, preferably between 1 and 2 and in particular is significantly less 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 wt .-% of other surfactants, based on the total ten sid quantity possible without the advantages of the method according to the invention atone.

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 by the process according to the invention Solutions of water glasses have proven particularly useful, 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 Glass glass solutions have 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 are used, inorganic salts or organic polycar boxylate 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, show, based on the finished granule lat, carrier material contents of 10 to 50 wt .-%. Because highly concentrated surfactant granules latex are 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 overdry Water glasses also find sodium in preferred embodiments of the invention carbonate, acrylic acid / maleic acid copolymers and trisodium citrate as carrier materials en use. Mixtures of the carrier substances, in particular car, are also preferred bonat / silicate mixtures and citrate / silicate mixtures.

The surfactant preparation form is granulated and dried, after the invention according to the method, granulate particles are obtained in which the active substance is part is wisely 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 carried out in all of the processes according to the invention Devices are made 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, proposed that the combination of the two process steps in one intermittently or continuously running fluidized bed is carried out. It is in particular  re preferred to carry out the process continuously in the fluidized bed. Doing so the surfactant preparation form into the fluidized bed from a common nozzle brings. The mixture of the two liquid to pasty constituents of the Tensid-Zu Form of preparation can take place beforehand or only in the nozzle. Prefers The fluidized bed apparatus used has base plates with dimensions of at least at least 0.4 m. In particular, fluidized bed apparatuses are preferred, the bottom plate 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 large size have a diameter greater than 5 m. A perforated board is preferably used as the base plate denplatte or a Conidurplatte (commercial product from Hein & Lehmann, Federal republic of Germany). The method according to the invention is preferably used for Vortex air velocities between 1 and 8 m / s and in particular between 1.5 and 5.5 carried out m / s. The granules are discharged from the fluidized bed more advantageously about a size classification of the granules. This classification can, for example with a screening device or through an opposed air flow (classifier air) follow, which is regulated so that only particles from a certain particle size out of the Fluidized bed removed and smaller particles retained in the fluidized bed. In a preferred embodiment, the inflowing air settles out of the heated one or unheated classifier air and the heated bottom air together. The soil air temperature temperature is preferably between 80 and 400 ° C, in particular between 90 and 350 ° C. The vortex air cools due to heat loss and the heat of vaporization the components of the non-surfactant solvent. In a particularly preferred Embodiment, the temperature of the vortex air is about 5 cm above the floor plate 60 to 120 ° C, preferably 65 to 90 ° C and in particular 70 to 85 ° C. The air Entry temperature is preferably between 60 and 120 ° C, especially below 100 ° C and with particular advantage between 70 and 85 ° C. In the invention The procedure performed is the mixture of the two solutions that together make up the Form surfactant preparation, blown through a nozzle into the fluidized bed, in the there are no additional solids as starting mass. In the continuously working The dried surfactant preparation form acts as a carrier or fluidized bed wise germ material. The components of the non-surfactant solvent evaporate  partially or completely, the dried to dry germs with additional quantities of introduced surfactant preparation form are encased in such a way that the carrier substance envelops the active substance. This special structure of the granulate, the only through the simultaneous injection of active substance and carrier material solution is obtained by one and the same nozzle results from the fact that the evaporating is not surfactant solvent in the evaporation process from the fresh material to the Grain condenses on the layer and evaporates from the grain on the surface deposits.

In the granulation according to the invention - especially when alkylbenzenesulfonates as Surfactants are used - to maintain the vortex granulation process a powdering agent, preferably zeolite or sodium carbonate, into the we can be 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 after This variant can be advantageous to the method according to the invention, it is to be executed tion of the invention, however, is not absolutely necessary.

In this way, the process according to the invention results in surfactant granules which dissolve easily in cold water without being hygroscopic. The granules ha have a high mechanical stability and therefore excellent trickle and silage properties create. With organic solvents that do not destroy the grain structure Only remove small amounts of active substance from the uncrushed granules Most of the active substance can be extracted from the ground granules.

The washing and cleaning active produced by the inventive method Surfactant granules have bulk densities above 600 g / l. They are ideal as a comm 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 and cleaning active granules in amounts of more than 10 wt .-%, esp  especially in amounts above 20 wt .-%, based on the total washing and cleaning agent. For processing in detergents with a high bulk density or for other special applications a bulk density is that according to the invention Process produced detergent and cleaning active granules above 700 g / l, in particular above 800 g / l, is preferred.

Advantageously, can be washed and cleaned by the method according to the invention gungactive surfactant granules are produced, their total surfactant content, based on the total granulate is more than 40% by weight. Surfactant levels above 50% by weight % and in particular above 60% by weight are preferred. In the preparation of of alkyl benzene sulfonate (ABS) and alkyl polyglycoside (APG) granules are ABS Contents above 40% by weight, preferably above 50% by weight and in particular more than 60% by weight, based on the granulate, is 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 glue or much less, can also be used. But it is before adds that the proportion of other surfactants 20 wt .-%, based on the total surfactant content, in does not exceed the granules according to the invention.

Examples

By simultaneous spraying of aqueous surfactant and carrier material solutions A multi-channel nozzle in a fluidized bed dryer were compounds of the following types get composition:

Composition [% by weight]

Composition [% by weight]

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 of the agent to a 1- 1-vessel were given, in which there was 500 ml of demineralized water, the  was stirred by a propeller stirrer at a speed of 900 rpm. The guide Ability was detected via a conductivity measuring cell and fixed on a recorder hold. The measurement was carried out until no increase was ascertainable. The time to reach The constant conductivity of the agent was set at 100%, the corresponding values whose dissolution times are calculated.

Solubility test

Solubility test

All of the compounds E1 to E8 produced according to the invention can be found in air store without sticking or losing their free-flowing properties. A comparison ver search between E5 and a commercially available comparable ABS compound with a Bulk weight of 400 g / l and an active substance content of 85% by weight gave 8 Hours of storage (55% relative humidity) the following values:

Hygroscopicity (8-hour storage trial)

Hygroscopicity (8-hour storage trial)

The ABS / APG compounds produced according to the invention are ideal additives Detergents suitable because they give the agents an 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 a high bulk density. Rather, such mixtures already stuck in Mixers to viscous to pasty masses that could not be dried further.

Claims (12)

1. Process for the production of detergent granules with active detergent and bulk weights 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, so that the highly hygroscopic , sticky active substance is at least partially enclosed by the non-sticky carrier substance. 2. The method according to claim 1, characterized in that as a non-surfactant Lö mono- and / or polyfunctional alcohols, preferably in amounts of 0.5 to 10 wt .-%, based on the total solution to be sprayed, who used the. 3. The method according to any one of claims 1 or 2, characterized in that as not surfactant solvent water, preferably in amounts of 25 to 80% by weight, based on the total amount of the non-surfactant solvent. 4. The method according to any one of claims 1 to 3, characterized in that on maintenance of the vortex granulation process continuously a powdering agent, preferably zeolite or sodium carbonate, is introduced into the fluidized bed.   5. The method according to any one of claims 1 to 4, characterized in that as Trä a silicate / citrate mixture is used. 6. The method according to any one of claims 1 to 5, characterized in that the alkyl benzenesulfonate (ABS) content of the washing and cleaning active surfactant granules upper half of 40% by weight, preferably above 50% by weight and in particular above half of 60 wt .-%, based on the granules. 7. The method according to any one of claims 1 to 6, characterized in that the alkyl polyglycoside (APG) content of the detergent granules active in washing and cleaning above of 50% by weight, preferably above 60% by weight and in particular above of 70 wt .-%, based on the granules. 8. The method according to any one of claims 1 to 7, characterized in that the Ge total surfactant content of the detergent granules active in washing and cleaning above 40 % By weight, preferably above 50% by weight and in particular above 60 % By weight, based on the granules. 9. The method according to any 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 on the ABS and APG amount included. 10. Washable and cleaning-active surfactant granules with a bulk density above 600 g / l, containing more than 60 wt .-% alkylbenzenesulfonate. 11. Washing and cleaning-active surfactant granules with a bulk density above 600 g / l, containing more than 60 wt .-%, preferably more than 70 wt .-% alkylpo lyglycoside. 12. Washing and cleaning agents containing at least 10% by weight, preferably min at least 20% by weight of a process end product according to claims 1 to 9.