EP0692022A1

EP0692022A1 - Production of pourable washing agents

Info

Publication number: EP0692022A1
Application number: EP94912525A
Authority: EP
Inventors: Wolfgang Seiter; Adolf Wiche
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1993-04-01
Filing date: 1994-03-23
Publication date: 1996-01-17
Also published as: DE4310672A1; WO1994023013A1

Abstract

In order to improve the solubility of pourable washing agents having an apparent density in a range from 600 to 1000 g/l and produced by granulation then processed, finely powdered alkaline metal soaps with 12 to 18 C atoms in the fatty acid residue are added to the thus obtained products.

Description

"Production of free-flowing detergents"

The present invention relates to a process for the production of free-flowing detergents and to the detergents obtained therewith. In particular, the invention relates to detergents which contain alkali metal soaps.

The use of alkali metal soaps in detergents for cleaning textiles has long been known. In recent times, however, the use of soap has increasingly been replaced by the use of other synthetic anionic surfactants. Commercial detergents today only contain alkali metal soaps in the range from 0.5 to 5% by weight.

According to Ullmann's Encyclopedia of Technical Chemistry, Volume 24, pp. 115 ff, 1983, powdered detergents are produced by granulation essentially in two different ways. Around 80% of all detergents are produced using the spray drying principle. In the case of pressure atomization, the thermally stable, ie. H. prepares a slurry in the tower under the influence of hot air and does not decompose or volatile substances.

The slurry is atomized at pressures up to 100 bar. The dried tower powder emerges from the tower cone at a temperature of around 90 to 100 ° C and is cooled to prevent clumping.

In order to turn the tower powder into a salable detergent, the missing recipe components have to be added. Such components are thermally sensitive substances, such as sodium perborate, bleach activators, enzymes, fragrances, and occasionally also certain surfactants and colored speckles. The preparation can take place immediately after the atomization process. The tower powder is fed into a storage bunker. The tower powder and the remaining components are metered in by means of belt scales with mutual locking and fed via a collecting belt to a mixer which works well but to avoid abrasion. Liquid dosage components can be dosed via volume metering pumps on the way to the mixer or in the mixing unit itself. The finished powder product is sieved and packaged. In addition, crystallization processes for the production of dust-free, granulated products are defined under the generic term “spray mixing process”. In recent times, the extrusion and compacting of detergents has also become increasingly important.

The metered solids and liquids are usually fed to a spray mixing apparatus after partial or complete premixing. Mixing units are suitable for mixing the solids, for spraying on the liquids and for agglomeration to form dust-free products, the mixing action of which is based on the gravity of the powder during rotating movement, on the movement of the powder by means of internals or on the swirling of the powder by air. In downstream stages, thermally sensitive substances such as perborate can be added.

Commercial detergents for use in drum or tub washing machines often have a bulk density of 600 to 1000 g / l. With these detergents, however, difficulties arise when flushing into the washing container. Due to the high density, part of the detergent remains in the induction channel and is entrained in subsequent rinse cycles, since in the case of commercially available washing machines for the household area there is generally only one possibility for water to be inducted. The amount of detergent introduced into the final rinse cycle cannot be fully discharged in the different rinse cycles, so that residues of the detergent remain on the laundry.

From DE-A-19 16 861 a process for the production of detergents and cleaning agents is known, which comprises an active detergent mixture of a nonionic synthetic detergent, an anionic synthetic detergent and an alkali soap, and a skeleton salt mixture of an alkali polyphosphate and a water-soluble alkali salt of the nitrilotries - includes acetic acid. It is proposed that an aqueous slurry containing nitrilotriacetic acid, sodium tripolyphosphate and a nonionic synthetic detergent, an anionic synthetic detergent and less than the total amount of soap required in the end product be heat dried and the remainder of the the amount of soap required in the preparation step for the heat-dried granular washing and cleaning agents can be added in solid, finely divided form. The granular detergent and cleaning agent obtained in this way accordingly has satisfactory free-flowing properties and the hygroscopicity of the product is considerably reduced.

DE-A-25 47 203 discloses similar powdery, nonionic surfactants and soap-containing detergents and cleaning agents, as well as processes for their production.

It is proposed that two powdery constituents of different compositions, namely one containing at least a part of the nonionic surfactant, poor in soap compared to the total composition of the two powdery constituents, obtained by spray drying, from calcium-binding water-insoluble aluminum sodium silicates essentially free powder and a further powder, which is enriched in soap at least in a ratio of 3: 1 compared to the total composition of the two powders.

From DE-C-25 45 190 powder detergents and cleaning agents containing water-insoluble silicates and methods for their production are known. These are produced analogously to DE-A-25 47 203. EP-A-0432449 discloses the use of soap in detergents in the range from 0.5 to 8%. The soap is gradually added to the base powder obtained by spray drying. The soap is preferably used in narrow particle size distributions. This is intended to avoid negative effects on the non-ionic surfactants contained in the detergents. Scale-like soaps are preferably used, and in particular the flowability of a powder obtained is assessed. EP-A-0 265 258 discloses the use of needle-shaped soap powder.

None of the above-mentioned documents deals with the washing-in behavior of, in particular, highly compressed detergents with high bulk density in commercially available washing machines. Accordingly, the object of the present invention is that

To improve the washing-in behavior of high-density detergents, so that no

Residue remains in the induction channel, which is added to the wash liquor during rinses following the washing process and remains as a residue on the laundry.

Accordingly, in a first embodiment, the invention consists in providing a process for the production of free-flowing detergents with a bulk density in the range from 600 to 1000 g / l, which have an alkali metal soap content in the range from 0.2 to 5% by weight. -%, based on the detergent, which is produced by known granulation processes, for example by atomizing pressure nozzles or spray mixing, and subsequent processing to give the finished product, finely divided alkali metal soap having 12 to 18 carbon atoms in the fatty acid residue being added during the processing.

By "granulation" of this invention the term free-flowing detergent according to the present invention are in the context thus refers to all known methods by means of which granules erha ^"th. Includes the possibility extruded detergent prepared according to sici known extrusion process. A Ausführuπgsform The invention provides that granules produced by pressure atomization or the spray mixing process are subsequently extruded, the alkali metal soaps optionally being added here before the extrusion, but it is also possible to retrofit the extruded detergents with alkali metal soaps to act upon.

Soaps, in particular alkali metal soaps, are known to be used in commercial detergents, inter alia as foam inhibitors. Usually these soaps are of natural or synthetic origin with a high proportion of Cιg_24 fatty acids. Other suitable foam inhibitors are, for example, organopolysiloxanes and their mixtures with microfine, optionally silanized silica, and paraffins, waxes, microcrystalline waxes and their mixtures with silanized silica or bistearylethylenediamide. Mixtures of different foam inhibitors used, for example those made of silicone, paraffins or waxes.

Surprisingly, it was found that adding the soap powder in the preparation step led to improved washability of the washing powder. When using conventional alkali metal soaps, which have a wider chain distribution, no improvement in the washing-in behavior could be found, despite the likewise reduced hygroscopicity of the detergent; rather, residues of the detergent remained on the laundry even after washing, including rinsing.

If, according to the invention, there is talk of finely divided alkali metal soaps, in contrast to the usual ones, then alkali metal soaps with a grain size of not more than 1.6 m, in particular not more than 1.2 mm, are preferably defined. Since, as is known, the surface approximately represents a function of the grain size, it is particularly preferred to make the grain size of the alkali metal soaps as small as possible in order to achieve a maximum improvement in the washing-in behavior through a high degree of surface coverage, with the least possible change in the bulk density of the detergent to reach.

In the event that the finely divided alkali metal soaps are used in the detergents without further foam inhibitors, it is preferred to use the amount of finely divided alkali metal soap at the upper limit of the range from 0.2 to 5% by weight. Thus, in the absence of further foam inhibitors, a content of finely divided alkali metal soap in the range from 2 to 5% by weight, in particular 3 to 5% by weight, is particularly preferred.

In the same way it makes sense to use the amount of finely divided alkali metal soap at the lower limit of the range of 0.2 to 5% by weight in the presence of further foam inhibitors in the detergents. The detergents thus produced according to the invention preferably contain finely divided alkali metal soap in the range from 0.2 to 1.5, in particular 0.2 to 1,% by weight. Although one embodiment of the present invention consists in adding the entire amount of finely divided alkali metal soap to the detergents during the preparation step, it is likewise possible to add a certain proportion of soap to the detergent preparation form, for example the detergent slurry.

However, in order that the detergent behavior of the detergents is improved in an optimal manner, it is preferred to add at least 50% by weight of the alkali metal soaps in finely divided form only during the preparation. In this case, the remaining amount of soaps can already be added during the granulation process, for example during spray drying. Conventional soaps with a broad chain distribution as defined above can then also be used here in this process stage.

Soaps in the case that various soaps with, for example, various carbon chain regions or CI2 i8-F ^e t ^tsäure which are once coarse and finely divided once, optionally in various Verfahrens¬ used steps, a further preferred Ausführungs¬ of the present Invention in that in the process according to the invention at least 70% by weight of the finely divided alkali metal soap has a grain size of not more than 1.0 mm and in particular at least 50% by weight of not more than 0.7 mm. This alkali metal soap is then added in the preparation step.

The alkali metals of the finely divided alkali metal soaps are preferably selected from sodium and / or potassium salts.

In a further embodiment of the present invention, the process is characterized in that the finely divided alkali metal soaps are selected from salts of the fatty acids: lauric acid, myristic acid, palmitic acid, stearic acid or salts of natural fatty acid mixtures of coconut acid, palm kernel acid or tallow fatty acid.

In the context of the present invention, it has been found that the chain length of the fatty acid residues of the alkali metal soaps is of some importance for improving the washing-in behavior. When using short chain It was found that finely divided alkali metal soaps are particularly well suited to fulfilling the objects on which the invention is based, since in addition to improving the washing-in behavior, no detergent residues remain on the laundry. Accordingly, a further embodiment of the present invention consists in the use of finely divided alkali metal soaps with a chain length in the fatty acid residue of in particular 12 to 16 carbon atoms.

By coating the detergent powders or extrudates with the relatively hydrophobic, finely divided alkali metal soaps, an apparently relatively poorly water-soluble layer initially appears on their surface. When water, especially cold tap water, is flushed in, this surface appears to be partially dissolved and gelled. However, the geometric shape of the powder particle or extrudate practically does not change. Rather, the individual parts stick together, so they are obviously entrained with the water that is flushed in and do not stick in the flushing channel. However, the solution behavior of the detergents in the wash liquor is not adversely affected.

With the aid of the method according to the invention, detergents can be produced which, of course, in addition to soap can also contain other constituents known from the field of detergent technology. These are known to the person skilled in the art from a wealth of primary and secondary literature. Anionic surfactants, nonionic surfactants, builder substances and cobuilder substances should be mentioned in particular. Among the anionic surfactants, Cg-Ci3-alkylbenzenesulfonates and / or Cg-Cis-alkylsulfates are particularly preferred. Zeolite, crystalline layered silicates, in particular disilicates, and cobuilders are preferably used as builder substances, and polycarboxylates, polymeric polycarboxylates and / or fat-dissolving or fat-repelling polymers are used as cobuilders.

In addition, it is known to the person skilled in the art in the present field that detergents may contain further ingredients selected from bleaching agents, bleach activators, optical brighteners, enzymes, enzyme stabilizers, salts of citric acid, salts of Polyphosphonic acid, neutral filling salts, dyes, fragrances, opacifiers and pearlescent agents, graying inhibitors, fabric softening substances, and water-soluble salts such as bicarbonates, carbonates, silicates or mixtures of these salts.

For the purposes of the present invention, all of the aforementioned constituents and ingredients can also be used in the context of the present invention in customary concentrations.

In a further embodiment of the present invention, this relates to detergents which can be obtained by the process defined above.

The following examples and comparative examples serve to explain the invention.

B e i s p i e l e

example 1

For granules obtained by spray drying, each based on the made-up detergent,

8% by weight Na-Ci2-alkylbenzenesulfonate,

4% by weight Ci2-Ci4 fatty alcohol with 3 E0, 2% by weight taig fatty alcohol with 5 E0, 0.2% by weight fluorescent brightener,

15% by weight sodium carbonate,

25% by weight of zeolite 4A (calculated as anhydrous active substance),

5 wt% cobuilder

were in the processing step

2% by weight of coconut fatty acid soap (sodium salt) with a carbon chain length of essentially 12 to 16 carbon atoms and a grain spectrum (indication by weight) of

> 1.6 mm, 0.8 mm, 0.4 mm, 0.2 mm, 0.1 mm <0.1 mm 0 25 33 25 16 1%

16% by weight sodium perborate monohydrate,

6 wt .-% tetraacetylethylenediamine and 2 wt .-% enzyme and

0.3% by weight of perfume oil added.

The rest ad 100 wt .-% consisted of water and salts; the bulk density was 625 g / l. Comparative Example 1

Analogously to Example 1, the same amount of the soap mentioned was added to the slurry for spray drying. The bulk density was 630 g / l.

Example 2

Analogously to Example 1, 5% by weight of the soap defined in Example 1, based on the made-up detergent, were admixed in the preparation step. A bulk density of 605 g / 1 was obtained.

rating

The detergents were checked for washability in a commercially available washing machine dispenser (Zanussi 285). This washing device applies among other things. with regard to the flushability as particularly critical.

The induction devices were clamped in a holder, which consisted of a metal frame with laterally adjustable support rails. After connection to the water network, a fixed water flow rate per time was set for the induction channel. The amount of water was regulated by a pressure reducing valve, which was connected between the water connection point and the induction device. Electrically controlled solenoid valves prevented the water from flowing in unevenly.

100.00 g of washing powder were added to the induction device. This was the clear wash chamber. The washing powder was always added uniformly by means of a funnel with a sealing cap fixed above the middle of the chamber. The drop height of the powder to be tested was measured from the top edge of each induction chamber and was 10 cm from the bottom edge of the hopper with the flap open. The dispenser was dried before each addition. The flushing process was started 60 seconds after opening the funnel closure. After opening the water inlet, a maximum of 10 1 water was allowed to run in. After this amount of water, the inflow was stopped and the remaining amount of detergent was determined, which was deducted 30% of the weight (empirically determined value) for water taken up. The mean is formed from five individual determinations.

The mean values obtained are assessed according to the following scheme:

No residue in the induction channel:

Grade A: 0 to 10 1 water inlet = easy to flush

Residue in the induction channel:

Grade B: up to 10 g residue = satisfactory wash-in

Note C: over 10 g residue = difficult to wash in

Table 1 below shows the data thus obtained.

Table 1

Example of winding behavior Zanussi channel

1 B 10 See C 17 2 B 4

It can be seen from this table that, with the aid of the method according to the invention, the washing-in behavior of the detergents in the Zanussi channel can be washed in poorly (comparative example 1, 17 g of residue) to satisfactory washable (example 1, 10 g residue) could be improved without changing the recipe. If the amount of finely divided alkali metal soap is further increased (example 2, 4 g of residue), the washing-in behavior is improved and the amount of residue in the washing-in channel is thus reduced. By washing in clear water through the same washing-in channel, according to the invention, no detergent residues remain on the laundry in Examples 1 and 2.

Claims

Patent claims

1. Process for the production of free-flowing detergents with a bulk density in the range from 600 to 1000 g / l and a content of alkali metal soap in the range from 0.2 to 5% by weight, based on the detergent, by known pelletizing processes and subsequent preparation to the finished product, finely divided alkali metal soap having 12 to 18 carbon atoms in the fatty acid residue being added during the preparation.

2. The method according to claim 1, characterized in that the Rieselfähi gene detergents in addition to alkali metal soaps contain further foam inhibitors, in particular organopolysiloxanes, paraffin, waxes, microcrystalline waxes and mixtures thereof with silanated silica or bistearyl-ethylenediamide.

3. The method according to claim 1 or 2, characterized in that the detergents in the presence of further foam inhibitors a content of finely divided alkali metal soap in the range of 0.2 to 1.5 wt .-%, in particular 0.2 to 1 wt .-% % exhibit.

4. The method according to claim 1, characterized in that the detergents in the absence of further foam inhibitors have a content of feinteili¬ ger alkali metal soap in the range of 2 to 5 wt .-%, in particular 3 to 5 wt .-%.

5. The method according to one or more of claims 1 to 4, characterized ge indicates that the finely divided alkali metal soap has a grain size of not more than 1.6 mm, in particular not more than 1.2 m.

6. The method according to one or more of claims 1 to 4, characterized ge indicates that at least 70 wt .-% of the finely divided alkali metal soap has a grain size of not more than 1.0 mm and in particular at least 50 wt .-% of not more than 0.7 mm.

7. The method according to one or more of claims 1 to 6, characterized ge indicates that the alkali metals of the alkali metal soaps are selected from sodium and / or potassium.

8. The method according to one or more of claims 1 to 7, characterized ge indicates that the alkali metal soaps are selected from salts of the fatty acids: lauric acid, myristic acid, palmitic acid and stearic acid or salts of natural fatty acid mixtures of coconut acid, palm nucleic acid or tallow fatty acid.

9. The method according to one or more of claims 1 to 8, characterized ge indicates that at least 50 wt .-% of the total alkali metal soap content in the form of the finely divided alkali metal soap is added in the preparation step.

10. The method according to one or more of claims 1 to 9, characterized ge indicates that the detergent further contains anionic surfactants, non-ionic surfactants, builder substances and optionally cobuilder substances.

11. The method according to claim 8, characterized in that the detergent further contains ingredients which are selected from bleaching agents, bleach activators, optical brighteners, enzymes, Enzymstabili¬ catalysts, salts of citric acid, salts of polyphosphonic acid, neutral filling salts, dyes, fragrances , Opacifiers and pearlescent agents, graying inhibitors, fabric softening substances and water-soluble salts such as bicarbonates, carbonates, silicates or mixtures of these salts.

12. The method according to one or more of claims 1 to 11, characterized in that free-flowing detergents by means of Druckdüsenzer¬ sputtering or spray mixing process are optionally prepared with subsequent compacting or by extrusion.