WO1997013831A1

WO1997013831A1 - Washing-agent additive

Info

Publication number: WO1997013831A1
Application number: PCT/EP1996/004337
Authority: WO
Inventors: Norbert Schall; Wolfgang Heininger; Rüdiger Hirsch
Original assignee: Süd-Chemie AG; Dalli-Werke Wäsche- und Körperpflege GmbH & Co. KG
Priority date: 1995-10-12
Filing date: 1996-10-05
Publication date: 1997-04-17
Also published as: DE59610244D1; ATE234912T1; EP0856046B1; DE19538028A1; EP0856046A1; ES2193265T3

Abstract

Described is a washing-agent additive in agglomerate form, the additive being characterized in that it contains at least one swellable layered silicate, an optical brightener and a surfa ctant.

Description

Patent application

Detergent additive

description

The invention relates to a detergent additive which contains at least one swellable layered silicate and further additive components.

DE-A-34 34 854 describes a process for producing a granular, free-flowing detergent component which contains inorganic carrier substances (in particular sodium aluminosilicates of the zeolite A type), surfactants and optical brighteners. Zeolites are not swellable layer silicates.

WO 94/05 761 describes a process for producing a detergent with a high bulk density and good solubility, using non-swellable silicates (eg zeolites), surfactants and optical brighteners. WO 89/08 695 describes a stabilized particulate composition for use in detergents which contains optical brighteners or enzymes. The particles are protected by a bentonite coating. Separated particles contain bleach, surfactants or builders.

DE-A-35 26 405 describes layered silicates with limited swelling capacity, and their use in detergents and cleaners, which also contain surfactants and optical brighteners. The layered silicates are synthetic aluminosilicates.

Detergents which contain sodium aluminosilicates, such as zeolites, that is to say non-swellable silicates, and optical brighteners and surfactants are also known from other references.

There has been a trend towards higher bulk densities in the development of detergents since the mid-1980s. The motive for this is the possibility of saving superfluous volume-increasing fillers and saving packaging material. Another advantage can be seen in the fact that a smaller volume is required for transport and trading. The consumer has the advantage that detergent packs take up less space in the shopping basket.

An essential step in the development of highly concentrated detergents with a high bulk density is the omission of fillers or so-called adjusting agents, such as sodium sulfate.

DE-C-3 424 987 describes the production of detergent concentrates with high bulk density, which do not contain sodium sulfate as a setting agent. Here, a basic powder is produced by spray drying, which contains the usual detergent ingredients, such as surfactants, carboxymethyl cellulose (CMC), sodium polyphosphate, zeolite A, water glass, optical brighteners includes. The base powder obtained, which has a low bulk density and is free of sodium sulfate, is sprayed with other nonionic surfactant to increase the bulk density and dry-mixed with a separately produced granulate with a high bulk density. In this product, the optical brightener is exposed to contact, especially oxidation, by other detergent components.

Another major disadvantage of highly concentrated detergents with a high bulk density is that the detergent constituents can come into contact with one another in high individual concentrations without dilution with an adjusting agent. This was not the case with detergents with a low bulk density, which contained up to 25% sodium sulfate. In detergent concentrates, the active constituents of the detergent are packed side by side in high concentration. In the worst case, the detergent components can react with one another with hydrolysis or oxidation, which can impair the function of the ingredients and the detergent.

A problem is the incorporation of optical brighteners in detergent concentrates with a high bulk density. In the production of detergents with a low bulk density, the optical brightener was either processed in the spray product or it was subsequently mixed as a powder in the tower product (spray product). If the optical brightener is not separated from the bleaching agents also contained in the detergent, such as sodium perborate, but especially sodium percarbonate, by a coating (coating) produced in the production or by the presence of diluting, spatially separating and water-absorbing adjusting agents, op ¬ table brighteners are oxidized. The bleaching potential consumed in this way is therefore no longer available for the subsequent bleaching action in the wash liquor. Above all, however, the oxidation product of the optical brightener can be colored yellow be, whereby the detergent shows a yellow tint on the one hand, and on the other hand draws the yellow oxidation product of the brightener noun onto the washing textiles, which leads to an impairment of the aesthetic aspect, especially in the case of white laundry.

The oxidation of the optical brightener preceding Ent stehung of active oxygen in the detergent powder is a Reak¬ tion ren zurückzufüh¬ of ^'washing powder contained bleaches, especially when percarbonate is contained as a bleaching agent. In the presence of tetraacetylethylenediamine (TAED), peracetic acid is formed, from which active oxygen is released. This problem is discussed in M. Husslein et al. , 36th International Conference 1994, WFK - Research Institute for Cleaning Technology eV, pages 82-85.

In the case of detergents with a low bulk density which contained sodium sulfate, the problem was not serious because the water which triggered the reaction could be bound to the sodium sulfate by the formation of crystal water. The problem, however, is very clear in the case of detergents with a high bulk density. There was therefore a need to protect optical brighteners, in particular of the stilbene type, from the reaction with the active oxygen formed in the laundry powder.

Another problem associated with the formulation of detergent concentrates is that the agglomerates with a high bulk density do not dissolve quickly enough in the wash liquor and are found in the "wash liquor sump". Since the agglomerates are not subjected to sufficient mechanical stress there, they dissolve only partially, as a result of which the active components are partially removed from the washing action.

The detergent agglomerates of high bulk density generally have poor dispersibility; this can be improved by adding dispersants and disintegrants, which swell in contact with water and blow up or loosen the agglomerates, which leads to improved solubility and availability of the active components. In the article by H. Führer, Seifen-Öle-Fette-Wachsen, 18. (1963), pp. 561-562, it is described that natural, water-swelling smectites can be used as disintegrants in compacted detergent tablets .

The presence of a disintegrant disintegrating the detergent agglomerates is also necessary in order to avoid the so-called "brightener spotting". Brightener spotting is the result of prolonged contact of undissolved, brightener-containing agglomerate with the laundry. Through the direct. Contact of locally over-concentrated optical brightener is transferred to the tissue at the contact point in undesirable, high concentrations, locally limited. This is particularly visible in the presence of UV light in the form of slight stains and represents an impairment of the aesthetic aspect. The detergent agglomerates should therefore contain disintegrants so that they are blasted in contact with the wash liquor, as a result of which the optical brightener is homogeneous dissolved in the wash liquor and direct contact of the detergent agglomerates with the laundry is avoided.

If several detergents of different recipes are produced in a production plant for detergents, problems arise if detergents containing brighteners and which do not contain brighteners are produced in the same plant. Detergents formulated without brighteners are contaminated with residues of the optical brightener in systems in which detergents containing brighteners were previously produced. Even if the system is thoroughly cleaned beforehand, contamination cannot be completely ruled out.

There is therefore a need for a detergent additive in which the brightener component can be mixed into the detergent in a suitable manner while avoiding contact with the essential parts of a production system for detergents, without the function of the optical brightener being impaired.

The object of the invention was to provide a detergent additive in agglomerate form (granulate form) which contains at least one swellable layered silicate and an optical brightener which, with good mechanical stability, disintegrates well in water and in which the optical brightener is present in a homogeneous distribution and against Oxidation is protected by the oxidizing agent contained in the detergent.

The invention relates to a detergent additive in agglomerate form, which is characterized in that it contains at least one swellable layered silicate, an optical brightener and a surfactant.

It is believed that the surfactant helps to at least partially distribute the optical brightener homogeneously between the layers of the layered silicate, since the layer expansion in the X-ray diffraction diagram of the dried product is from about 1.05 to 1.30 nm to about 1.35 up to 1.85 nm is observed.

Due to the suspected incorporation of the optical brightener between the layers of the layered silicate, it is reliably removed from the oxidation processes during the storage of the detergent, and "brightener spotting" on the laundry is avoided when the detergent is used.

In addition to the swellable layered silicate, the optical brightener and the surfactant, the detergent additive preferably contains an alkali carbonate. The detergent additive according to the invention preferably contains

a) about 5 to 60 wt. % swellable layered silicate (s), * b) about 5 to 35% by weight. -% surfactant (s); c) about 5 to 60 wt .-% alkali carbonate (s), * d) about 1 to 20 wt .-% optical brightener (s).

The swellable layered silicate is preferably a natural or synthetic clay mineral. The swellable clay mineral is preferably montmorillonite, beidellite, saponite or hectorite.

The montmorillonite can be used in the sodium or calcium form or in the form of a calcium montmorillonite ion-exchanged with soda. Synthetically produced clay minerals from the group mentioned above can also be used. The layered silicate is preferably used in an amount of 10 to 50% by weight, in particular 30 to 50% by weight.

The swellable layered silicates have the property of intercalating polar agents between the silicate lamellae under internal crystalline swelling, which is noticeable at higher concentrations in an increase in the layer spacing.

The surfactant is preferably selected from the group of anionic and nonionic surfactants, the nonionic surfactant preferably being a mixture of fatty alcohol ethoxylates of various degrees of ethoxylation.

The fatty alcohol ethoxylates have the formula:

RO- (E0) _y -H,

where R is a hydrocarbon radical with 10 to 18, in particular their 12 to 18 carbon atoms, EO an ethylene oxide group and y a number from 2 to 20, in particular from 3 to 10. Significantly prepared mixtures of fatty alcohol ethoxylates of different degrees of ethoxylation can also be used.

These fatty alcohol ethoxylates are eagerly stored between the layer lamellae. The nonionic surfactants, in which the optical brighteners, in particular of the stilbene type, are soluble, promote their transport between the lamellae of the swellable layered silicate. The optical brighteners are intercalated between the lamellae of the layered silicate and thus protected from the reaction with other detergent components.

The layered silicates in granular form intercalated with surfactants and optical brighteners swell in water and release the surfactants and optical brighteners of the solution in water. The optical brighteners and the surfactants are therefore fully available in the washing process. Due to the swelling effect of the layered silicate agglomerate in water, the agglomerates are blown up and distributed in the water, as a result of which "brightener spotting" is avoided.

The alkali carbonate, which is used in particular in the form of sodium carbonate, fulfills several functions:

If the layered silicate is agglomerated with the surfactant, a soft agglomerate is obtained which becomes sticky with increasing surfactant content and which is not free-flowing and not capable of ensiling. The presence of the sodium carbonate improves the mechanical stability of the agglomerate and reduces its stickiness. In addition, the sodium carbonate in the detergent is desirable for adjusting the alkalinity and as a builder component. The alkali carbonate is preferably used in amounts of approximately 10 to 40% by weight, in particular approximately 12 to 30% by weight. If the layered silicate is agglomerated with the surfactant, a soft agglomerate is obtained which becomes sticky with increasing surfactant content and which is not free-flowing and not capable of ensiling. The presence of the sodium carbonate improves the mechanical stability of the agglomerate and reduces its stickiness. In addition, the sodium carbonate in the detergent is desirable for adjusting the alkalinity and as a builder component. The alkali carbonate is preferably used in amounts of approximately 10 to 40% by weight, in particular approximately 12 to 30% by weight.

The optical brightener is preferably a stilbene derivative. However, benzoxazole, coumarin and pyrazoline derivatives can also be used. These products generally have an anionic dye residue, which is why it was surprising that they are embedded between the negatively charged layers of the swellable layered silicate.

Suitable optical brighteners are, for example

(a) Cyanuric acid chloride diaminostilbene (CCDAS), in which R can have the following meanings:

Type: tetraaniline

(Trade name Tinopal ^® TAS-X from Ciba-Geigy)

CH ₂ -CH ² R = -N 0

CH ₂ -CH $

Type: dimorpholine

(Trade name Tinopal ^® DMS-X HC)

CH ₃

/

R = -N

CH ₂ -CH ₂ -OH

Type: amino style

(Trade name Tinopal ^® 5 BMS-X)

Trade name: Tinopal ^® CBS-X

Trade name Tinopal ^® BLS-X

Since the surfactant is hygroscopic, the agglomerate particles of the detergent additive are preferably coated with synthetic zeolite, which improves the flowability of the agglomerate particles. The coating with zeolite further improves the whiteness of the agglomerate. The agglomerate preferably has a bulk density of more than about 700 g / liter and, owing to this high bulk density, is compatible with highly concentrated detergents at high density.

The invention further relates to a process for the production of the detergent additive described above in agglomerate form, which is characterized in that (a) the optical brightener (s) is added as an aqueous slurry simultaneously with the surfactant (s) gives the layered silicate (s) or (b) dissolves at least part of the optical brightener (s) in the surfactant (s) beforehand and adds the solution to the layered silicate (s).

The swellable layered silicate is preferably mixed with the alkali metal carbonate before the addition of the optical brightener / surfactant.

The powder components can, for example, in an intensive mixer, e.g. are mixed together in an Eirich mixer. The optical brightener (preferably as an aqueous dispersion) and the surfactant are then sprayed simultaneously or in succession to the powder component while swirling. This forms an agglomerate which is powdered with the zeolite at a low mixing speed. The resulting agglomerate is sieved and surface-coated by adding further zeolite (in particular zeolite P) in powder form to reduce the stickiness and to improve the whiteness.

The agglomerate obtained is readily dispersible in water. The optical brightener is protected against oxidation and is fully available after the agglomerate has dissolved in the wash liquor. Due to the presence of the layer silicate swellable in water, no "brightener spotting" occurs. The agglomerate can be subsequently added to the detergents produced in brightener-free production plants, so that the additives were not contaminated with brighteners.

The invention further relates to a detergent containing the detergent additive described above in addition to conventional detergent components such as anionic and nonionic surfactants, builders (builders), polymers (co-builders), graying inhibitors, bleaching agents and bleach activators , Enzymes, foam inhibitors, fragrances and / or dyes.

The preferred production process is explained below.

The powdered layered silicate and the powdered sodium carbonate are premixed intensively. With intensive swirling of the powder mixture, the surfactant or a solution of the surfactant is added. At the same time, the optical brightener or a mixture of different optical brighteners is added as an aqueous dispersion (slurry). Alternatively, a solution of the optical brightener in a surfactant solution can be added to the powder mixture.

If the optical brightener is added as an aqueous dispersion, the mixture agglomerates at a water content of about 20 to 30% by weight, based on the total mixture. After a mixing time of about 2 to 5 minutes, an agglomerate is obtained which is dried in a suitable dryer, preferably in a fluidized bed dryer, to a residual water content of about 2 to 15% by weight, preferably of about 5 to 10% by weight becomes. The agglomerate obtained is sieved using a sieving machine to a particle size of approximately 0.2 to 2.5 mm, preferably 0.5 to 1.7 mm. The fraction <0.2 mm is returned to the agglomeration. The resulting coarse grain is crushed with a roller crusher and placed on the screening plant again. If part of the optical brightener is added to the powder mixture together with the surfactant, the optical brightener in powder form is first dissolved in the surfactant. The weight ratio between surfactant and optical brightener can be 15: 2 to 4:10, preferably 10: 3 to 10: 8. The solution or dispersion of the optical brightener in the surfactant is added to the powder with intensive stirring, at the same time further portions of the optical brightener are added in an aqueous dispersion.

After a mixing time of about 2 to 5 minutes, an agglomerate forms, which is somewhat sticky due to the presence of the surfactant and therefore tends to stick. By adding about 0.5 to 5% by weight of a synthetic zeolite during the last 30 seconds of the agglomeration process, the tackiness of the agglomerate is reduced to such an extent that the agglomerate can be dried in a fluidized bed and sieved off as described.

The sieved agglomerate is placed in a drum mixer (for example in a drum mixer from Telschig) or in a granulating plate. Then about 3 to 15% by weight, preferably about 5 to 10% by weight, of synthetic zeolite in fine-grained form are added. The average particle size of this powder should preferably be <20 μm, in particular approximately 3 to 10 μm. When the agglomerate is mixed with the powder, the powder accumulates on the outer surface of the agglomerate. Since the powders used have a whiteness of> 90% (R 456, Elrepho), a white coating is formed around the agglomerate surface colored yellow by the brightener, so that the agglomerate obtained is white and indistinguishable from the color of the detergent is.

The detergent additive produced according to the described method has the following additional advantages: The bulk density is greater than 700 g / liter, so that it is compatible with detergents with a high bulk density. Due to the swelling effect of the layer silicate contained in the detergent additive, the agglomerates rapidly disintegrate in water. No brightener spotting is observed on the laundry. The active components surfactant and optical brightener are fully available in the detergent. The presence of layered silicate and alkali carbonate makes the agglomerate mechanically stable. The agglomerate can be subsequently added to the detergent, so that essential parts of the detergent production system are not contaminated with optical brighteners.

The invention is illustrated by the examples below.

example 1

A detergent additive was produced according to the following recipe:

A: Bentonite (Laundrosil ^® DGA, Süd-Chemie AG) 40% by weight

B: sodium carbonate 15.52% by weight

C: nonionic surfactant 10.00% by weight

R- (0-CH ₂ -CH ₂ ) ₄ -OH (R = C ₁₄ / C ₁₅ )

D: Optical brightener A 18.6% by weight

(Tinopal ^® DMS, slurry in water with 36% active ingredient)

E: optical brightener B 5.88% by weight

(Tinopal ^® CBS, slurry in water with 30% solids content)

F: Zeolite P 10% by weight 800 g of component A and 310.4 g of component B were placed in an Eirich intensive mixer type R02 (filling 3-5 liters, power 2.7 kW) and mixed for 1 minute. Then component C was added during mixing, followed by addition of components D and E. A yellow tinted agglomerate having a water content of 18% by weight was obtained. This agglomerate was dried in a drying cabinet to a residual moisture of 6% by weight of water. Then the grain fraction was sieved 0.2 to 1.7 mm.

The sieved agglomerate was then mixed with 10% by weight of Zeolith P and mixed in a granulating plate. The surface of the agglomerate was coated with zeolite powder, whereby a white agglomerate was obtained.

2% by weight of the detergent additive was mixed into a new generation compact detergent produced by spray agglomeration with a bulk density of 850 g / liter. This detergent contained:

20% by weight Na percarbonate

5 wt% TAED

6% by weight nonionic surfactant (component C) 12% by weight fatty alcohol sulfate (R0S0 ₃ Na _; R = C16 / C18)

As a comparison, an equivalent amount of brightener A and brightener B was introduced into an identical detergent during the production of the spray agglomerate. Both detergent formulations were stored in a closed refill bag at 40 ° C. for 4 weeks. The breakdown was calculated from the brightener content determined before and after the storage test by means of HPLC analysis. The optical aspect of the detergent was also assessed visually. The results are shown in Table I. Table e I

Degradation after brightener use 4 weeks / 40 ° C optical aspect

Brightener A Brightener B Output 4 weeks / 40 ° C

add detergent after 20% 40% white white

example 1

over spray 40% 50% white yellow agglomerate

When using the detergent additive, the breakdown of brighteners A and B is significantly less, and there is no annoying yellow tint of the detergent due to oxidation products.

Example 2

As an alternative to Example 1, components A and B were mixed in an Eirich mixer. A solution of 134 g Tinopal ^® DMS-X hc (powder form) in 438 g of component C (surfactant) was prepared, which during the mixing process to Mi¬ εchung of component A and B is added. Component E was then added as a slurry. A yellow-tinted agglomerate was also obtained, which was further processed as in Example 1.

2% by weight of the detergent additive according to this example again mixed into the detergent described in Example 1 and tested accordingly. The results are given in Tabel 'le II.

Table? II

Degradation after

Brightener use 4 weeks / 40 ° C optical aspect

Brightener A Brightener B Output 4 weeks / 40 ° C

about detergent additive after 20% 40% white white Example 2

The stabilization of brightener A occurs regardless of whether it has been incorporated into the detergent additive as a slurry in water (Example 1) or in nonionic surfactant (Example 2).

Example 3

A detergent additive was produced according to the following recipe:

A: Bentonite (Laundrosil ^® DGA, Süd-Chemie AG) 42 wt.

B: sodium carbonate 21.2% by weight

C: Nonionic surfactant 9.0% by weight R- (0-CH ₂ -CH ₂ ) ₄ -OH (R = C ₁₄ / C ₁₅ )

D: Nonionic surfactant 9.0% by weight

R- (0-CH ₂ -CH ₂ ) ₈ -OH (R = C ₁₄ / C ₁₅ )

E: Optical brightener A 7.0 wt. - '

(Tinopal ^® DMS, slurry in water with 36% active ingredient)

F: Optical brightener B 1.8% by weight!

(Tinopal ^® CBS, slurry in water with 30% solids content)

G: Zeolite P 10 wt. _S-

As in Example 1, 840 g of component A and 424 g of component B were premixed in an Eirich intensive mixer for about one minute. A mixture of components E (140 g) and F (36 g) was then added. Then 180 g of component C and 180 g of component D (premixed) were added.

A slightly yellowish, somewhat sticky agglomerate was obtained. Have been used to reduce stickiness 5% zeolite P added and approx. 20 see. mixed.

The agglomerate obtained was sieved to a grain size of 0.2 mm to 2.0 mm.

The sieved agglomerate was then mixed again with 5% by weight of zeolite P and mixed in a granulating plate, the surface of the agglomerate being coated with zeolite powder, as a result of which a white agglomerate was obtained.

5% by weight of the detergent additive according to this example was mixed into a compact detergent produced by spray drying with a bulk density of 700 g / liter. Among other things, this detergent contains:

14% Na perborate monohydrate

5% TAED

6% non-ionic surfactant C + D = ι _: ι

12% fatty alcohol sulfates (RO-S0 ₃ Na _; R = C ₁₆ / C _l8 )

As a comparison, an equivalent amount of brightener A and brightener B was introduced into an identical detergent during the manufacture of the spray product.

A position stability test was then carried out, as described in Example 1. The results are shown in Table III. Table e III

Degradation after

Healer use 4 weeks / 40 ° C optical aspect

Brightener A Brightener B Output 4 weeks / 40 ° C

Adding detergent after 7% 0% white white Example 1

over spray- 24% 0% white yellow product

Brightener A breaks down much more slowly when using the detergent additive than when used in the spray product. The detergent remains white.

Claims

claims

1. Detergent additive in agglomerate form, characterized in that it contains at least one swellable layer silicate, an optical brightener and a surfactant.

2. Detergent additive according to claim 1, characterized in that it contains an alkali carbonate in addition to the swellable layered silicate, the optical brightener and the surfactant.

3. Detergent additive according to claim 1, characterized in that it contains: a) about 5 to 60 wt .-% swellable layered silicate (s) b) about 5 to 35 wt .-% surfactant (s), c) about 5 to 60% by weight of alkali carbonate (s), d) about 1 to 20% by weight of optical brightener.

4. Detergent additive according to one of claims 1 to 3, characterized in that the swellable layered silicate is a natural or synthetic clay mineral.

5. Detergent additive according to claim 4, characterized in that the swellable clay mineral is montmorillonite, beidellite, saponite or hectorite.

6. detergent additive according to any one of claims 1 to 5, da¬ characterized in that the surfactant is selected from the groups of anionic and non-ionic surfactants.

7. detergent additive according to claim 6, characterized in that the non-ionic surfactant is a mixture of fatty alcohol ethoxylates of different degrees of ethoxylation.

8. detergent additive according to one of claims 1 to 7, characterized in that the optical brightener is a stilbene derivative.

9. Detergent additive according to one of claims 1 to 7, characterized in that the agglomerate particles are coated with synthetic zeolite, preferably zeolite P.

10. Detergent additive according to one of claims 1 to 9, characterized in that the agglomerate has a bulk density of more than 700 g / liter.

11. A process for the preparation of a detergent additive in the form of an agglomerate according to any one of claims 1 to 10, characterized in that (a) the optical brightener (s) as an aqueous slurry simultaneously with the surfactant (s) to the (the) Layered silicate (s) are or (b) at least part of the optical brightener (ε) is previously dissolved in the surfactant (s) and the solution is added to the layered silicate (s).

12. The method according to claim 11, characterized in that the swellable layered silicate is mixed with the alkali carbonate before the addition of the optical brightener / surfactant.

13. The method according to any one of claims 11 or 12, characterized in that an agglomerate with a particle size of about 0.2 to 2.5 mm and a residual water content of 2 to 15 wt .-% is formed.

14. The method according to any one of claims 11 to 13, characterized ge that the agglomerate obtained is coated with 3 to 15 wt .-% of a synthetic zeolite, preferably of zeolite P.

15. Detergent containing a detergent additive after one of claims 1 to 10 or produced according to one of claims 11 to 14, in addition to conventional detergent components.