BG60918B1 - Active additive for detergents - Google Patents

Abstract

"Builder" agent, for a detergent composition, consisting of an aqueous solution of an alkali metal silicate, in particular of sodium or potassium, with an SiO2/M2O molar ratio of the order of 1.6 to 4, and of an inorganic product, inert with respect to the silicate, the said inorganic product representing from 5 to less than 55 % of the total weight expressed on a dry basis and the remaining water in combination with the silicate/silicate expressed on a dry basis ratio by weight being greater than or equal to 33/100, preferably greater than or equal to 36/100. Use of this builder agent in detergent compositions, more particularly in powder detergent compositions, in particular for washing machines and dishwashers.

Description

TECHNICAL FIELD

The invention relates to an active detergent additive, in particular to powder detergents, and in particular to washing machines and dishwashers.

The invention also relates to a process for preparing granules of hydrated alkali metal silicates and carbonates of carbonates and to the granules themselves.

BACKGROUND OF THE INVENTION

Active detergent additives are known to improve the surfactant properties of detergent compositions.

The active additive needs to have an effect called "softening" of the water used for washing. It is necessary to eliminate calcium and magnesium, which are present in the water in the form of soluble salts, and in impurities in washing machines - in complex forms that are more or less soluble. The removal of calcium and magnesium can be accomplished by complexation in the form of soluble compounds, by ion exchange or by precipitation. When using sedimentation, the process must be controlled to avoid the formation of sludge in the washing machines or parts of the washing machines. This control is achieved with the help of water-soluble polymers having affinity for calcium and magnesium.

It is also necessary for the active additive to have an emulsifying effect of surfactants with respect to oily contaminants, a dispersing effect with respect to pigment contaminants such as metal oxides, clays, silica, dust, humus, limestone, soot. This dispersion effect is usually achieved by the presence of polyanions, which give a high density of negative charges to the interfacial surfaces.

It is also necessary that the active additive has a favorable ionic strength of the surfactant, in particular by increasing the size of the micelles.

It is necessary for the active additive to have OH ions to sap the fat and to increase the negative surface charges on the textile surfaces and on the surfaces of the impurity particles.

Silicates have long been regarded as good additives for washing, but in reality they are used less in phosphate-free formulations intended for washing.

The most commonly used silicates in these cases have a molar ratio of SiO ₂ / Na ₂ 0 ranging from 1.6 to 2.7. They are commercially available in the form of concentrated solutions of 35-45 wt. % dry residue or in the form of finely divided powdered silicate and then pressed.

Commercial concentrated solutions are most commonly obtained from fully amorphous silicate called "glassy" as well as "soluble glass".

These glasses were dissolved in water in a pressure autoclave at 140 ° C. Thus, commercially available solutions having a dry residue of about 45 wt% for silicate with a ratio of 2 and about 35% for silicate with a ratio of 3.5.

The concentrated silica solutions were introduced into an aqueous slurry containing the other ingredients of the detergent. The slurry is then spray dried. The silicate, sprayed and dried with the other ingredients, contains not more than 20% bound water in terms of its dry content.

Commercial powder is obtained by spray drying of concentrated glassy silicate solutions. It is necessary to maintain from 19 to 22% by weight of water in relation to the final product, in order to ensure good solubility of the latter.

It has been found that when it is placed in a solution in the soap baths in the amount of 1-3 g / l, this powdered silicate containing only 19-22% by weight of bound water (relative to the final product) has poor quality properties of the active supplement.

In fact, this dissolved powdered silicate gives many monomeric silicates of formula Si / OX) ₄ , where X is H or Na, which have no active additive effect. These monomer species cannot be re-linked to form polyanions unless the silica concentration is at least 50-500 g / Ι, and the process is slow.

Such concentrations of silica, as well as the slow kinetics of polymerization of the monomer species, are incompatible with the washing conditions and duration of washing.

What is found for powders containing from 20 to 22% chemically bound water (relative to the final product) is true of the compositions containing silicate with 20% bound water (relative to dry silicate) prepared by introducing concentrated silica solution in the slurry followed by drying.

Known granular active detergent additive, which is an alkali metal silicate with a molar ratio of 1.6 / 1 to 5/1, and the bound water is 1725% / 1 /.

The active detergent additive according to (2) is a spray-dried mixture of aqueous sodium silicate and sodium carbonate solution at a temperature of 300 - 450 ° C for 6 - 30 s. The resulting bulk material has a high degree of dehydration.

SUMMARY OF THE INVENTION

It has been found that when alkali metal silicate contains large quantities of silicon atoms in the form of Q ₂ and Q ₃ , the polyanionic species obtained by diluting from 1 to 3 g / Ι in the washing medium have a duration of action sufficient to to be used as an active supplement.

The expression "silicon atoms in the form of Q ₂ and Q ₃ " indicates the degree of bonding of the silicon atoms between them. Q ₂ means that each silicon atom is involved in two -Si-O-Si- bonds, with the other two bonds having an -Si-O-O termination group in which X is an alkali metal or H. Q ₃ means that each a silicon atom participates in three bonds -Si-O-Si-, with the free bond ending at -Si-O-O.

The active detergent additive contains an aqueous solution of an alkali metal silicate and a mineral product inert to silica, wherein, according to the invention, the Si0 ₂ / M ₂ 0 mode ratio, where M is an alkali metal, ranges from 1.6 to 4, and the mineral product is from 5 to 55% of the total weight. The weight ratio of silica bound water to silica, expressed as dry matter, is greater than or equal to 33/100, preferably 36/100.

The alkali metal is sodium or potassium.

By "inert" is meant a chemical inert material.

Mineral products inert to silica and compatible with aqueous silica are preferably water-soluble. These products may be sodium carbonate, sodium sulfate, sodium borate, sodium perborate, metasilicate and also phosphates or phosphonates such as trisodium phosphate, sodium tripolyphosphate, these products being present alone or in a mixture.

The use of products having a detergent activity, in particular sodium carbonate, is preferred.

The mineral product is from 5 to 55%, preferably from 20 to 40% of the total weight of the dry residue, i. of the sum of the weights of the solution, expressed as dry matter, and the mineral product.

The mineral product is introduced directly into an aqueous solution of alkali metal silica or into water and after mixing in an aqueous solution of alkali metal silica.

The active additive according to the invention can be in any structured (powder, granules) or unstructured form.

The silicate may have a molar ratio of Si0 ₂ / M ₂ 0 in the range of 1.6 to 4, preferably 1.8 to 3.5.

In a preferred embodiment, the active additive is a 10-60% solution, preferably 35-50% by weight of an alkali metal silicate, in particular sodium or potassium.

The concentrated solution of alkali metal silicate used as the active additive is obtained by dissolving in water "soluble glasses" in a pressure autoclave at 140 ° C and then possibly diluting it. It can also be prepared by other known methods, for example by direct sand treatment with a concentrated sodium hydroxide solution.

NMR reveals that: a solution with 45% dry glassy silicate content and a SiO ₂ / Na ₂ 0 = 2 molar ratio contains 34% bound silicon atoms of type Q ₃ , 51% - of type Q ₂ , 12% of the type Q ₍ and 3% of the species Q _o .

- a solution with 35% dry residue and a ratio of 3.5 contains 46% of the type Q ₃ , 27% of the type Q ₂ , 16% of the type Q ₄ , 9% of the type Q, and 2% of the type Q _o .

The term "bound" to silica water means that which is in the form of crystalline hydrate.

The weight ratio of water bound in silica / silicate, expressed as dry matter, should be greater than or equal to 33/100, preferably 36/100. This corresponds to the need for the silicates to be in polyanionic forms. It is not difficult for the person skilled in the art to determine the upper limit of this ratio, which corresponds to the limit to which the silicate can be retained in powder form of a flowing fluid, i. be applicable for washing. An exemplary weight ratio of water bound to silica / silicate, expressed as dry matter, should be less than or equal to 120/100.

The increased content of silicate in the products according to the invention makes it possible to achieve completely satisfactory "anti-scale" properties in washing or washing machines.

Where the active additive is in unstructured form, in particular in solution, it may be used by further atomizing the outlet laundry powder in the case of atomisation installations or on a dry mixture so that it is absorbed by the powders. The resulting powder mixture is dried, if necessary, in such a way that the weight ratio of water remaining bound to silica / silicate, expressed as dry matter, remains greater than or equal to 33/100, preferably 36/100.

The dry silicate / washing powder ratio is from 1/100 to 30/100, preferably from 10/100 to 20/100.

When the active additive of the invention is in structured form, it can be prepared by contacting an aqueous solution (A) consisting of a mixture of a concentrated aqueous solution of an alkali metal silicate (1) and a mineral product (2) in dissolved condition with compound (B) with a composition identical to the aqueous solution (A). The contacting is thus carried out in such a way that the weight ratio of silica / silicate bound water, expressed as dry matter, after mixing, is greater than or equal to 33/100, preferably 36/100.

The aqueous alkali metal silicate solution (1) has a SiO ₂ / M ₂ O molar ratio of 1.6 to 4, preferably 1.8 to 3.5. The mineral product is inert with respect to silica, is compatible with the aqueous solution (1) and is 5 to 55% of the total weight of the dry matter.

M is an alkali metal unless otherwise indicated.

The aqueous solution (A) is prepared by any of the known methods. It can be obtained by introducing the mineral product in the form of powder or liquid into the aqueous solution of silica.

"Compound (B) with a composition identical to aqueous solution (A)" means any compound containing an alkali metal silicate and mineral product defined above, with the mineral product representing from 5 to 55% of the total dry weight substance. The compound (B) has a silica-silicate bound water / silicate weight ratio, expressed as a dry matter, greater than or equal to 33/100, preferably 36/100.

The compound (B) can be prepared by any of the known methods. Thus, it can be obtained by evaporation of a solution identical to the aqueous solution (A). It is preferable to control the evaporation in such a way as to preserve the desired amount of silica bound water, i. the weight ratio of silica / silicate bound water expressed as dry matter to be greater than or equal to 33/100, preferably 36/100.

In solution (A), the concentrated aqueous solution of the alkali metal silica has a weight ratio of water bound to the silica / silicate, expressed as a dry matter, greater than or equal to 33/100, preferably 36/100.

The contacting of an aqueous solution (A) with the compound (B) can be accomplished by adding, in particular, by spraying (A) onto (B) in any high-speed mixer of the LODIGE type or granulators / drum type, discs / at a temperature of from 20 to 95 ° C, preferably from 70 to 95 ° C.

The mineral products that can be used are those listed above.

The amount and concentration of the aqueous solution (A) are a function of the absorption and / or adsorption capacity of the mineral products present in the solution (A) and the compound (B), taking into account the potential for the mineral products to form crystallizing hydrates. In addition, the amount of silica-free water can be in the form of a hydrate in the carrier and can be readily determined by some of the known methods, for example by differential chemical analysis or by quantitative X-ray diffraction. The water available in the non-hydrate carrier may be determined by suitable physicochemical methods (thermoporosimetry, thermogravimetry, proton NMR, IR).

The limits of the absorption and adsorption capacity of mineral products can be determined by measuring the shear failure angle as a function of the amount of silica solution added.

If necessary, after contacting (A) and (B), a drying step may be applied under such conditions as to obtain the desired amounts of silica bound water.

Solutions of alkali metal silica under adsorption and / or absorbed form on alkali metal carbonate, which are in the form of co-granulates of hydrated alkali metal silicate and alkali metal carbonate, are an active additive according to the invention of high quality.

These co-granulates of the hydrated alkali metal silicates and of the alkali metal carbonates are characterized in that they can be obtained according to a method comprising the following steps:

a / spraying an aqueous solution composed of a mixture of an aqueous solution of an alkali metal silicate with a molar ratio of SiO ₂ / M ₂ 0 from 1.6 to 4, preferably from 1.8 to 3.5, and an alkali metal carbonate in an amount of from 5 to 55 wt. %, expressed as dry matter, on a layer of passing particles having a composition identical to the spray mixture passing through a rotary granulation device. The rate of passage of the particles, the thickness of the layer and the flow rate of the spray solution are such that each particle becomes a plastic co-granulate, contacting other particles;

b) optionally drying the co-granulates obtained in step (A), applying these steps in such a way that the final weight ratio of water bound to silica / silicate, expressed as dry matter, is greater than or equal to 33 / 100, preferably 36/100.

By "particles of the composition identical to the spray mixture" is meant particles containing an alkali metal silicate and an alkali metal carbonate, representing from 5 to 55% of the total weight, expressed as dry matter. Preferably, these particles have a weight ratio of water bound to silica / silicate, expressed as a dry matter greater than or equal to 33/100, preferably 36/100.

These particles can be obtained by any of the known methods, in particular they can be obtained by drying a solution identical to the aqueous solution composed of silicate and carbonate of the above-mentioned alkali metal. This drying is controlled in such a way as to maintain the desired amount of silica bound water, i. the weight ratio of water remaining bound to the silica / silicate, expressed as a dry matter, greater than or equal to 33/100, preferably 36 / 100. The layer of particles of the composition identical to the spray mixture may also be obtained from a dry mixture of carbonate and silicate in a weight ratio identical to that of the nebulizer solution, to the complete renewal of this layer from the resulting co-granulates (recycling).

In an aqueous solution composed of silicate / carbonate, the concentrated aqueous solution of the alkali metal silica preferably has a weight ratio of water remaining bound to the silica / silicate, expressed as a dry matter greater than or equal to 33 /

100, preferably 36/100.

Preferred alkali metal silicates and carbonates are those of sodium and potassium, and especially of sodium.

Preferably, between the steps A and B, the resulting co-granulates of step A are subjected to compaction.

According to a preferred embodiment of the invention, the silica solution used to produce the co-granulates has a dry silica residue in the range of 10 to 60%, preferably 35 to 50%.

The aqueous solution is sprayed on a silicate / carbonate mixture at a temperature of 20-95 ° C, preferably 70-95 ° C. It can be facilitated by the simultaneous introduction (eg by means of a bifluid nozzle) into pressurized air at a temperature of the same order.

The carbonates used can be of ordinary quality. Carbonates which are readily soluble and have increased adsorption / absorption capacity are preferred.

Along with the carbon particles, small amounts / less than 10% by weight of the co-granulates / other particles such as anti-precipitation polymers / carboxymethylcellulose /, enzymes, polyacrylates commonly used in the purification technique and having a diameter and density close to those of the carbonate / silicate particles.

The atomizing granulation device may be any rotary disk rotary device, a dragee receiving device, a rotating drum, a mixer granulator.

One preferred method of producing co-granulates is to use a rotary granulator to allow the particles to pass into a thin layer. Devices for receiving dragees with a pivot axis inclined with respect to the horizontal at an angle greater than 20 °, preferably greater than 40 °, are particularly suitable. Their geometry can be different - truncated cone, flat, stepped and a combination of the three shapes.

Another preferred method of producing co-granulates is to use a rotary drum having an inclination angle of at least 3%, preferably 5%. The carbonate / silicate particles pass at a temperature in the range of 15 to 200 ° C, preferably 15 to 120 ° C and most often 15 to 30 ° C.

The amounts of the solution based on the mixture of silicate / carbonate for atomization and the particles on the basis of the mixture of silicate / carbonate correspond to a ratio of liquid flow rate / particle flow rate / wetting ratio / from 0.05 to 0.8 Ι / kg, for preferably from 0.1 to 0.5 I / kg and most often from 0.15 to 0.3 Ι / kg, these values being expressed with respect to the sodium salts.

The flow rate of the nebulized solution and the rate of passage of the particles, as well as the thickness of the particle layer, are such that each particle absorbs the liquid and agglomerates with the other particles that it comes in contact with to form a plastic granulate rather than a slurry. mass.

The rate of passage of the particles and the thickness of the layer are controlled by the flow rate of introduction of the particles into the granulation device and by the characteristics of the latter.

The residence time of the particles in the disc or drum unit is typically between 15 and 40 minutes.

Depending on the starting materials, the dragee device can be adapted to obtain the desired product, taking into account the geometry / cross-cone, flat, stepped or a combination of the three shapes /, dimensions / height, diameter /, angle of inclination , the rotational speed and relative position of the solid and liquid feeders; For the drum: the geometry / diameter of the cylinder /, the angle of inclination, the speed of rotation, the loading of the cylinder, and the relative position of the solid and liquid feeders.

The compaction operation can be performed at room temperature by passing the obtained granules through a rotary device.

It is preferable to separate this device from that for granulation.

The compaction step can be accomplished by inserting and staying the granules into a rotating drum. The inclination angle of the latter is at least 3%, preferably at least 5%. The size of the drum, its rotational speed and the residence time of the granules depend on the desired density. The residence time is usually from 20 minutes to 3 hours, preferably from 20 to 90 minutes.

Mixer granulators are also suitable for the compaction process.

The granulation and compaction processes may also be carried out in the same device, for example in a stepwise device for receiving dragees. The pellet seal is achieved by passing them through the last steps of the device. In addition, these two operations can be performed in a two-section drum.

The compacted granules thus obtained are dried in some known manner. Particularly suitable is the fluidized bed drying using air and at a temperature of 40 to 90 ° C, preferably 60 to 80 ° C. This process is carried out for a time which is a function of the air temperature, the water content of the granules at the outlet of the granulation device and the desired water content of the dried granules, as well as the conditions of fluidization. These conditions can be adapted by any specialist, depending on the desired product.

The hydranates based on hydrated sodium and sodium carbonate silicates according to the invention obtained according to the method described above are intended for detergent formulations for washing machines and dishwashers and are typically characterized by:

- an alkali metal silicate, in particular sodium or potassium, in a Si0 ₂ / M ₂ 0 molar ratio of 1.6 to 4, adsorbed and / or absorbed on an alkali metal carbonate, this carbonate being from 5 to 55% of the weight of the silica adsorbed and / or absorbed by the carbon, the weight ratio of water remaining bound to the silica / silicate, expressed as dry matter, is greater than or equal to 33/100, preferably 36/100;

- bulk density without compaction of from 0.4 to 1.5 g / cm ³ , preferably from 0.5 to 1.5 g / cm ³ , and most commonly from 0.75 to 1 g / cm ³ ;

- average diameter (in the sense of percentage of passed particles) from 0.4 to 1.8 mm, preferably from 0.5 to 0.8 mm, with a deviation expressed as log ₁₀ , from 0.02 to 0.5, preferably from 0.05 to 0.3.

Preferably, the weight ratio of water remaining bound to silica / silicate, expressed as dry matter, is less than or equal to 120/100.

The method described above, involving granulation, compaction, drying, allows the preparation of granules based on hydrated alkali metal silicates and alkali metal carbonates, which dissolve rapidly in water.

Thus, the dissolution rates of up to 90 and 95% in water of the granules according to the invention are lower than 3 and 5 min respectively.

A dissolution rate in water of up to 90% or 95% means the time required to dissolve 90 or 95% of the product at a concentration of 35 g / Ι in water at a temperature of 20 ° C.

When structured (powders, granules), the active additive according to the invention is used in detergent compositions for dishwasher detergents in an amount of from 3 to 90% by weight, preferably from 3 to 70% by weight, of the compositions under consideration. The amounts used for formulations intended for washing lines are from 3 to 60% by weight, preferably from 3 to 40% by weight of the compositions in question / these quantities are expressed as weight of dry silicate relative to the weight of the composition /.

In addition to the active additive of the invention, at least one surfactant in an amount of 8 to 20%, preferably 10 to 15% by weight, of the composition in question is present in the laundry composition.

Such surfactants may be:

- anionic surfactants such as alkali metal soaps / alkali salts of fatty acids with C ₈ -C ₂₄ alkaline sulfonates / alkylbenzoleulfonates with C ₈ C ₁₃ , alkyl sulfonates with C _(2- C _[6 , oxyethylated and sulphonylated) ₆ -C ₁₆ , oxyethylated and sulfated alkylphenols with C ₈ C ₃ , alkaline sulfosuccinate (alkylsulfosuccinate with C ₂ -C ₁₆ ).

- non-ionic surfactants of the polyoxyethylated alkylphenols type with C ₆ -C ₁₂ , oxyethylated aliphatic alcohols with C ₈ -C ₂₂ , block copolymers of ethylene oxide with propylene oxide, carboxamides, optionally polyoxyethylated.

- amphoteric surfactants of the alkydimethylbetaine type.

- cationic surfactants such as alkyltrimethylammonium and alkyl dimethylethylammonium chlorides or bromides.

Other ingredients may be present in the laundry composition as active additives of the type:

- phosphates in the amount of 25% of the total weight of the composition,

- zeolites up to about 40% by weight of the total composition,

- sodium carbonate up to about 80% by weight of the total composition;

- nitrilacetic acid up to 10% by weight of the total composition;

- citric acid, tartaric acid up to 20% by weight of the total composition, the total amount of the active additive being from 0.2 to 80%, preferably from 20 to 45% by weight of the total detergent composition;

- bleaching agents such as perborates, percarbonates, chlorisocyanurates, Ν, Ν, Ν ', Ν', - tetraacetylethylenediamine up to about 30% of the total weight of the detergent composition;

- anti-precipitation agents of the type carboxylmethylcellulose, methylcellulose in an amount up to 5% of the total weight of the detergent composition,

- anti-scale agents of the type of copolymers of acrylic acid and maleic anhydride in an amount up to 10% of the total weight of the detergent composition;

- Sodium sulphate fillers for powdered detergents in an amount up to 50% of the total weight of the detergent composition.

The advantages of the active additive according to the invention are expressed in the following. The composition comprises a mineral product providing a softening effect and sodium silicate with a high content of bound water higher than or equal to 33/100, preferably 36/100. This silicate has a large amount of bonds of the silicon atoms of the Q ₂ and Q ₃ species, providing high efficiency of the active additive.

EXAMPLES FOR THE IMPLEMENTATION OF THE INVENTION

The following examples illustrate the invention without limitation.

Example 1. Synthesis of the active additive

Products used in synthesis:

- sodium silicate, solution with a molar ratio of Si0 ₂ / Na ₂ 0 = 2.8, dry residue 45 wt. Distribution of polyanionic species (as a percentage of silicon): Qo = 0.8%, Q, = 6.2%, Q ₂ and Q ₃ = 83%, Q ₄ = 10%.

- Sodium carbonate, anhydrous powder with a bulk density without compaction of 1.1 g / cm ³ , particle size distribution d50 = 0,5 mm

Synthesis. The pre-dissolved sodium carbonate is added with stirring to the sodium carbonate solution heated to 80 ° C. The addition of water to the sodium carbonate in this case makes it possible to work with a mixed solution whose dry residue is identical to the dry residue of the silica stock solution. Mixing is carried out in such a way that sodium carbonate is 30% of the total weight of silica and carbonate, expressed as dry matter.

The combined solution was dried in a thin layer dryer at 20 ° C for 20 h. The resulting solid was then ground into a Forplex mill. The last step consists of drying in a fluid bed at 30-40 ° C to give a solid with a carbonate composition of 30% by weight of the total carbonate and silica, expressed as dryness. The weight ratio of water remaining bound to silica / silicate, expressed as dry matter, is 49.7 / 100.

The product has the following properties. Bulk density without compaction 0.8 g / cm ³ , particle size distribution d50 = 0.5 mm, dlO = 0.1 mm and d90 = 1 mm. The solubility is less than 4 min for the dissolution of 99% of the product (conductometric measurement of the aqueous solution of the product at a concentration of 3 g / Ι at 20 ° C).

The complexing capacity of calcium is 197 mg CaCO ₃ per gram of anhydrous product. This capacity is calculated by measuring the residual calcium concentration over a period of 15 min, introducing the product at present t = 0 into a solution with a known calcium concentration (pH 10 buffer solution).

Example 2. Preparation of co-granulates.

The following products are used, sodium silicate, a solution with a molar ratio of SiO ₂ / Na ₂ O = 2.0, a dry residue of 45.5 wt.% And a density of 1.540 g / cm ³ ;

Powdered silicate, molar ratio Si0 ₂ / Na ₂ 0 = 2.05, dry residue 20% by weight, density 0.55 g / cm ³ , particle size distribution d50 = 0.12 mm. Sodium carbonate: light solution, bulk density 0.6 g / cm ³ , particle size distribution d50 = 0.12 mm. A 38% solution of carbonate at 80 ° C was prepared by mixing a solution of carbonate in a solution of silicate with a ratio of 2. The dry residue of the resulting mixed solution was 37.7%.

The granulation of this solution is carried out in a drum of length 1300 mm and diameter 500 mm, which rotates at 20 rpm. Granulation is initiated by starting from a starting layer composed of a crushed mixture of light carbonate and powdered silicate in a ratio of 2. The carbonate / silicate composition of this mixture is the same as the mixed solution. Granulation takes place in the first portion of the drum, where the solution is sprayed through an irrigator onto the powder layer. The drying is carried out in the second part of the drum, equipped with lifts and openings for blowing hot air in countercurrent.

Granulation, compaction and drying are carried out in the same apparatus. The product exiting the drum is partially recycled into the head of the drum after grinding and sieving a fraction of 0.2-1.25 mm. when the base of the source layer is completely updated with the newly obtained products, the granulation parameters are as follows:

- supply with mixed solution 6 to 8 l / h;

- Dust supply (recycling) 50 kg / h;

- wetting level 0.12 to 0.16 l / kg;

- air flow rate for drying 110 to 120 t ³ / h;

- drying air temperature 105110 ° C;

- average residence time in the drum 3040 min.

In this way co-granules with the following characteristics are obtained:

- ratio expressed as dry matter, carbonate / silicate 38/62; silica / silicate bound water content, expressed as solids 51 / 100-

- bulk density without compaction 0,89 g / cm ³ ;

Particle size distribution d50 = 0.45 mm, d95 = 0.8 mm with deviation from log ₁₀ - 0.37.

The granules obtained have a rate of dissolution:

- 90% by weight dissolved in 50 s (aqueous solution 35 g / Ι at 20 ° C).

- 95% by weight dissolved in 67 s (aqueous solution 35 g / Ι at 20 ° C).

- 99% by weight the product was dissolved for 154 s (aqueous solution 35 g / Ι at 20 ° C).

For comparison, a simple dry mixture of carbonate and powdered silicate used at the beginning of the process which is not the subject of the invention shows the following dissolution rate:

- 90% by weight dissolved in 55 s (aqueous solution 35 g / Ι at 20 ° C)

- 95% by weight dissolved in 108 s (aqueous solution 35 g / Ι at 20 ° C)

- 99% by weight of the product were dissolved for 266 s (aqueous solution 35 g / Ι at 20 ° C).

The complexing capacity of calcium is 243-249 mg CaCO ₃ per gram of anhydrous product. This capacity was calculated as in Example 1.

Example 3. Preparation of co-granulates.

The granulation method is the same as in Example 2, but the granulator operates in an open loop, i.e. it is charged with a dry powdered carbonate / silicate mixture and a mixed solution, but without recycling the product obtained. There is also simultaneous drying.

The granulation parameters are as follows:

- supply with mixed solution 6 to 8 l / h;

- Dust supply (recycling) 30 kg / h;

- wetting level 0.2 to 0.27 l / kg;

- air flow rate for drying 110 to 120 m ³ / h;

- drying air temperature 105110 ° C;

- average residence time in the drum 3040 min.

In this way co-granules with the following characteristics are obtained:

- ratio expressed as dry matter, carbonate / silicate 37/63;

- silica / silicate bound water content, expressed as dry matter 42/100;

- bulk density without compaction 0.54 g / cm ³

Granulometric composition: d50 = 0.57 mm, d95 = 0.78 mm with deviation from log ₁₀ - 0.12.

The granules obtained have the following dissolution rates:

- 90% by weight dissolved in 55 s (aqueous 35 g / l at 20 ° C);

- 95% by weight dissolved in 122 s (aqueous 35 g / l at 20 ° C)

- 99% by weight dissolved in 300 s (aqueous solution 35 g / l at 20 ° C).

These co-granulates are blended dry with the following additives to obtain the following composition for washing machines:

Laundry powder composition parts by weight The granulate was obtained 40 Sokalan CP5 4,8 (BASF copolymer) Tixolex 25 5 (amorphous silicone aluminate by Rhone-Poulenc) Sodium sulfate 7 TAED 5 LAB (80%) 6 Synperonic AZ 3 Synperonic A9 9 Esperase 0.3 (enzyme production of NEW) Tinopal DMSX 0.2 Tinopal SOP 0.2 (Ciba-Geigi bleach) Antifoam 2.5 Carboxymethylcellulose 2

Pollution testing is carried out in the FOM 71 washing machine manufactured by WASCATOR.

The test conditions are as follows. 60 ° C cycle used, total cycle time 70 min, no prewash, number of cycles - 3 per wash, water hardness, 32 French hydrotimetric degrees - wash quantity - 3,5 kg white cotton towels.

Test fabrics. Two sets of the following fabrics shall be affixed to each laundry, affixed with pins to the towels:

Gray cotton Test-Fabric

Krefeld 10C

IEC 106

EMPA 101

Gray Polyester / Cotton Test-Fabric Krefeld 20C EMPA 104 Protein Stains Blood (EMPA 111) Cocoa (EMPA 112) Mixture (EMPA 116) Oxidizing Stains: Tea (Krefeld 10 G) Cotton Ecru (EMPA 222) Wine (EMPA 114)

Detergent dosage:

1st batch: 5 g / l or 5 x 20 = 100 g per wash

2nd batch: 8 g / l or 8 x 20 = 100 g per wash

Method for determining the removal of dirt and stains

Photometric measurements (measurement of the amount of light reflected from a tissue) allow to calculate the percentage of pollution removal. ELREPHO 2000, manufactured by DATACALOR, is used.

Pollution removal is expressed by the following formula:

C-B percentage removal = - - - x 100 in which A represents the reflection of a white witness sample, B the reflection of a contaminated witness sample, C the reflection of a contaminated sample after washing. Reflections are determined using trichromatic blue without optical whitening effect. Number of sample measurements 4. Number of wash samples 2. Number of wash 3 - or 4 x 2 x 3 = 24 measurements of contamination, product and concentration tested.

Anti-boiling tests are performed on a SCHULTESS SUPER 6 DE LUXE drum machine. The test conditions are as follows. 60 ° C cycle used, total cycle time 65 min, no prewash, number of cycles 25 washes, water hardness: 21.2 French hydrotimetric degrees.

The fabrics used are a witness band that meets the specifications of the NET 73,600 standard, the amount of laundry is 3 kg of wiped 100% cotton, the amount of detergent is 1 5 g / l. The samples that have undergone 25 laundry are dried, weighed and calcined to 90 ° C. Determine the% by weight of the ash relative to the weight of the initial samples.

The individual test results are presented in Table 1.

Comparative Example 4. Preparation of co-granulates.

The granulation system is a drum rotating at 40 rpm, identical to that described in Example 2. The outlet diaphragm is adjusted in such a way that the residence time of the individual particle is between 15 and 20 min.

The drum was fed continuously at a flow rate of 37 kg / h of powdered carbonate having the same characteristics as that of Example 2.

Powder carbonate, rotating in the drum, was sprayed with a silicate solution identical to that of Example 2 at 80 ° C using an air temperature of 80 ° C through a flat head bifluid nozzle located in the first third of the drum. flow rate 18 1 / h.

The co-granulate at the exit of the drum is at room temperature and has a density of 0.68 g / cm ³ .

The co-granulate is continuously compacted for 1 hour in a smooth-walled rotating drum with a diameter of 500 mm, length

1300 mm and angled at 5%.

The drum speed is 20 rpm.

The granulate thus obtained is dried in a pseudo-5 boiling layer at a temperature in the order of 65 ° C (fluidization air temperature is 70 ° C) for 15 min.

The dry product has the following characteristics:

ratio expressed as dry matter carbonate / silicate, 66/34;

- silica / silicate bound water content, expressed as dry matter, 61/100.

Calcium complexing capacity of 285 mg CaCO ₃ per gram of anhydrous product. This capacity was calculated as in Example 1. The granulate has excellent storage behavior.

To these co-granulates, additives are added to the dry mix to produce a washing machine composition identical to that described in Example 4 (except the co-granule).

Pollution and scale removal tests have also been carried out with this detergent composition.

The results are presented in Table 1.

Table 1

Scale 5 g / l Comparative Example 4 3.72 Example 3 2.88 Washing results Gray cotton 5 g / Ι 40 ° C 32,2 32.9 Gray cotton 8 g / Ι 40 ° C 47 41,9 Gray cotton 5 g / Ι 60 ° C 51,4 49 Gray cotton 8 g / l 60 ° C 56,3 54,8 46.73 44.65 Polyester / gray cotton 5 g / l 40 ° C 39,2 35,3 Polyester / gray cotton 8 g / l 40 ° C 56.1 50,1 Polyester / gray cotton 5 g / l 60 ° C 56,8 55,7 Polyester / gray cotton 8 g / l 60 ° C 65,4 62,3 54.38 50.85 Protein spots 5 g / l 40 ° C 38,8 34.8 Protein spots 8 g / l 40 ° C 46,3 40,2 Protein spots 5 g / l 60 ° C 50.6 56,4 Protein spots 8 g / l 60 ° C 58.6 56,4 48.58 45.60 Oxidizing spots 5 g / l 40 ° C 42.1 42.1 Oxidizing spots 6 g / 1 40 ° C 59.5 55

Claims (19)

Claims An active detergent additive comprising an aqueous solution of an alkali metal silicate and a mineral product chemically inert to silica, characterized in that the molar ratio of Si0 ₂ / M ₂ 0, where M is an alkali metal, is in the range from 1.6 to 4, and the mineral product is from 5 to 55% of the total weight, with a weight ratio of silica-related water to silica, expressed as dry matter, greater than or equal to 2θ 33/100, preferably 36/100. An active additive according to claim 1, characterized in that the mineral product is sodium carbonate, sodium sulfate, sodium borate, sodium perborate, sodium methasilicate, phosphates or polyphosphates such as trisodium phosphate, sodium tripolyphosphate, such products can used alone or in a mixture. An active additive according to claims 1 and 2, characterized in that the mineral product is from 20 to 40% of the total weight, expressed as dry matter. An active additive according to claim 1, characterized in that the aqueous solution of the alkali metal silica has a dry residue of from 10 to 60%, preferably from 35 to 50%. An active additive according to claim 1, characterized in that the weight ratio of water remaining bound to the silica / silicate. expressed as dry matter is less than or equal to 120/100. An active additive according to claim 1, characterized in that the molar ratio of SiO ₂ / M ₂ O is from 1.8 to 3.5, where M is an alkali metal. 7. A method for producing granules of hydrated alkali metal silicates and alkali metal carbonates, comprising the first step of spraying an aqueous solution consisting of a mixture of an aqueous solution of an alkali metal silicate with a molar SiO ₂ / M ₂ 0 ratio of 1.6 to 4, preferably 1.8 to 3.5, and alkali metal carbonate in an amount of 5 to 55% of the total weight, expressed as dry matter, on a moving bed particles having a composition identical to the spray mixture passing through a rotary granulation device no, wherein the rate of passage of the particles, the thickness of the moving layer, and the flow rate of the nebulized solution are such that each particle is converted into a plastic co-granulate, contacting other particles, followed by a second step involving the eventual drying of the obtained co-granules to obtain a silica / silicate bound water weight ratio, expressed as dry matter, greater than or equal to 33/100, preferably 36/100, with M being an alkali metal. A method according to claim 7, characterized in that the alkali metal silicate and the alkali metal carbonate are those of sodium or potassium, preferably sodium. A method according to claims 7 and 8, characterized in that the co-granulates obtained in the first step are subjected to compaction. 10. A process according to claims 7 and 8, characterized in that the silica solution has a dry residue of from 10 to 60%, preferably from 35 to 50%. A method according to claim 7, characterized in that the first step is carried out at a temperature of from 20 to 95 ° C. A method according to claim 7, characterized in that the particles of the composition identical to the atomized mixture are obtained by drying a solution identical to said aqueous solution composed of silicate and alkali metal carbonate. A method according to claim 7, characterized in that the granulation is carried out on a rotary granulator, ensuring the passage of the particles into a thin layer. A method according to claim 13, characterized in that the rotary granulator is a device for producing dragees. A method according to claim 7, characterized in that the pelletizing device is of a drum type. 16. A method according to claim 7, wherein the particles of the sun composition, identical to the spray mixture, pass at a temperature of from 15 to 200 ° C. A method according to claim 7, characterized in that the amounts of the solution based on the silicate / carbonate mixture correspond to a liquid / particle flow rate ratio of 0.05 to 0.8 Ι / kg, preferably 0, 1 to 0.5 l / kg, these values being expressed as sodium salts. 18. A method according to claims 7 to 17, characterized in that the compaction is carried out at room temperature by rotating in rotary arrangement the co-granulates obtained in the first step. 19. Spherical co-granulates based on hydrated alkali metal silicates and alkali metal carbonates, characterized in that they are a silicate of alkali metal, in particular sodium or potassium, with a molar ratio of Si0 ₂ / M ₂ 0 of 1 , 6 to 4, adsorbed and / or absorbed on alkali metal carbonate, in an amount of 5-55% by weight of silica, adsorbed and / or absorbed by the carbonate, and the weight ratio of silica / silicate bound, expressed as dry matter , is greater than or equal to 33/100, preferably 36/100, with bulk th density without compacting is 0,4-1,5 g / cm ^3, preferably 0,5-1,5 g / cm ^3, and most preferably 0,75-1 g / cm ³ and the average diameter is from 0.4 to 1.8 mm, preferably 0.5 to 0.8 mm with a deviation expressed as log ₁₀ - 0.20.5, preferably 0.05-0.3.