EP0753568A2 - Granular builder for detergent compositions - Google Patents

Abstract

Granular washing agent builder (I) in the form of a cogranulate comprising a mixt. of NaHCO3 and crystalline sheet silicates of formula NaMSixO2x+1*yH2O, where M = Na or H, x = 1.9-4 and y = 0-20. The novelty is that (I) a) contains 5-50 wt.% crystalline sheet silicate and 50-95 wt.% NaHCO3; b) has a pH ≤ 10 in 1% soln. in distilled. water; c) has a Ca binding power ≥ 150 mg Ca/g (30 degrees dH) and a Mg binding power ≥ 4 mg Mg/g (3 degrees dH) and d) a bulk density ≥ 850 g/l. Also claimed is the prepn. of (I) by mixing together NaHCO3 and sodium silicate in powder form and feeding the mixt. into a zone where it is compacted under pressure between two rollers rotating in opposite directions to give a solid body (cuttle-bones) and reducing the solid body and then separating the desired grain sizes from the over- and undersized material. Also claimed are the washing and cleaning agents containing (I).

Description

The present invention relates to a granular detergent builder in the form of a cogranulate from a mixture of sodium hydrogen carbonate and crystalline phyllosilicates of the general formula NaMSi _x O _{2x + 1} * yH ₂ O, where M means sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20, a process for its preparation and its use.

For ecological reasons, builders based on phosphates, in particular alkali metal tripolyphosphates such as sodium tripolyphosphate, are being replaced in washing and cleaning agents by new builder systems, which generally consist of a synthetic, crystalline aluminosilicate (for example zeolite A), an alkali source (for example soda) and at least one Cobuilder exist. Nitrilotriacetic acid or its salts, phosphonates and also polycarboxylates, in particular those based on acrylic and / or maleic acid, are usually used as cobuilders individually or in combination with one another or in combination with other substances.

A disadvantage of the cobuilders mentioned is their negative ecological assessment. The polycarboxylates that are widely used today are not biodegradable.

For this reason, several attempts have been made in the prior art to achieve a predominantly inorganic builder system.

EP-0 425 428 B1 discloses a process for the production of crystalline sodium silicates with a layered structure, in which amorphous sodium silicate with a water content of 15 to 23% by weight in a rotary kiln at temperatures of 500 to 850 ° C. calcined, the calcine after crushing and grinding is fed to a roller compactor and then the school pen obtained after pre-crushing and sieving are processed into granules with a bulk density of 700 to 1000 g / l.

DE-A-43 30 868 describes a process for the production of compacted, granular sodium silicates, in which the sodium silicate with an average grain diameter of <500 μm is first mixed with a material which increases its hardness before it is compacted, crushed and sieved transferred to a press granulate with grain sizes of 0.1 to 5 mm.

EP-A-0 164 514 describes the use of crystalline sodium silicates for the softening of water which contains calcium and / or magnesium ions.

EP-A-0 563 631 discloses water-disintegrating cogranulates with a high bulk density made of aluminosilicates and crystalline sodium silicates with a layer structure, a process for their preparation and their use.

A disadvantage of all detergent formulations containing aluminosilicate is the water-insolubility of the aluminosilicates, which among other things causes an increased sewage sludge load. It is also disadvantageous that larger agglomerates can form during the processing of aluminosilicates or in the course of their use, so that the use of cobuilders is necessary in order to break up the aluminosilicates into a suspension of fine primary particles, since agglomerates of aluminosilicates - especially zeolite A - have no tendency to disintegrate into the primary particles.

The granules described in the abovementioned prior art have, in principle, a satisfactory softening of water, it being advantageous to be able to achieve a further increased water-softening effect so that anionic surfactants can develop their effectiveness more effectively.

Detergent formulations, such as those described in PCT / WO 92/18594, have a pH value of 10 to 11 in 1% strength solution in distilled water at 20 ° C. Detergent builder formulations, which include sodium carbonate (soda) as an alkali source contain, inherently have a pH of> 10. Alkali-reduced detergents, on the other hand, require other builders or builder combinations in which it would be desirable for the builder formulations to have an intrinsic pH in the range of ≦ 10. A low pH value contributes significantly to protecting delicate fabrics during the washing process.

It is therefore an object of the present invention to provide substances on an inorganic basis which, with a high bulk density in water, easily disintegrate into the primary particles, whose intrinsic pH is in the range ≦ 10, which have an increased water-softening effect and which are soluble in water reduce sewage sludge pollution.

• a) der granulare Waschmittelbuilder 5 bis 50 Gew.% kristallines Schichtsilikat und 50 bis 95 Gew.-% Natriumhydrogencarbonat enthält;
• b) einen pH-Wert von ≦ 10 in 1%-iger Lösung in destilliertem Wasser aufweist;
• c) ein Calciumbindevermögen von ≧ 150 mg Ca/g (30° dH) und ein Magnesiumbindevermögen von ≧ 4 mg Mg/g (3° dH) aufweist und
• d) ein Schüttgewicht von ≧ 850 g/l aufweist.

The invention therefore relates to a granular detergent builder in the form of a cogranulate from a mixture of sodium bicarbonate and crystalline phyllosilicates of the general formula NaMSi _x O _{2x + 1} * yH ₂ O, where M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20, characterized in that

• a) the granular detergent builder contains 5 to 50% by weight of crystalline layered silicate and 50 to 95% by weight of sodium hydrogen carbonate;
• b) has a pH of ≦ 10 in 1% solution in distilled water;
• c) has a calcium binding capacity of ≧ 150 mg Ca / g (30 ° dH) and a magnesium binding capacity of ≧ 4 mg Mg / g (3 ° dH) and
• d) has a bulk density of ≧ 850 g / l.

x =

Ca oder Mg

w =

Massenanteil im Cogranulat

Surprisingly, it was found that the cogranulates according to the invention have a greatly increased calcium and magnesium binding capacity in the form of a synergism (Figs. 1 and 2). The synergism is shown in the fact that the values found for the calcium and magnesium binding capacity differ from the calculated calcium and magnesium binding values of the mixing line. Theoretically, it had to be expected that the calcium and magnesium binding values of the cogranulates would ideally obey the following calculation formula (calculation of the mixing line) (SKS-6 stands for layered silicate): $${\text{x BV = x BV (SKS-6® granules 100\%) * w (SKS-6®) + x BV (NaHCO}}_{\text{3rd}}{\text{Granules 100\%) * w (NaHCO}}_{\text{3rd}}\text{)}$$

x =

Ca or Mg

w =

Mass fraction in the cogranulate

The granular detergent builder preferably has a bulk density of ≧ 900 g / l.

The degree of reaction between crystalline layered silicate and sodium hydrogen carbonate is preferably between 5 and 60%.

The sodium silicates in the granular detergent builder according to the invention preferably have an SiO ₂ / Na ₂ O ratio of (1.9 to 2.1): 1.

The present object is also achieved by a process for producing a granular detergent builder in the form of a cogranulate from a mixture of sodium hydrogen carbonate and crystalline phyllosilicates of the general formula NaMSi _x O _{2x + 1} * yH ₂ O, where M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20, which is characterized in that sodium hydrogen carbonate and sodium silicate are mixed together in powder form; that the mixture is fed to a zone in which it is compacted under pressure between two rollers rotating in opposite directions to form a solid (Schulpen); that you crush the solid; and that the desired grain sizes are finally separated from the oversize and undersize.

In the above-mentioned method, the pressure of the rolls preferably corresponds to a line pressure Kratt> 20 kN / cm at 200 mm roll diameter.

The Schulpen preferably have a temperature of ≦ 70 ° C.

The crystalline sodium disilicate with a layer structure contained in the cogranulates according to the invention (δ-sodium disilicate is commercially available from Hoechst AG, Federal Republic of Germany, under the name SKS-6®) is slowly water-soluble, as a result of which sludge relief in the sewage treatment plants is achieved.

Since the explosive effect of the crystalline sodium disilicate contained in the cogranules according to the invention is considerable, small amounts of SKS-6® are sufficient in the cogranulate, so that the cogranulates in water easily disintegrate into the primary particles and agglomerates or compactates are suspended.

Due to the water solubility of the crystalline sodium silicates contained in the cogranulates according to the invention, the component soda can optionally be completely omitted in the detergent or cleaning agent formulation, since the crystalline sodium disilicate is a source of alkali.

With the compacting it is observed that there is a temperature difference between the temperature of the starting powder mixture and the school pent temperature of at least 25 ° C. This increase in temperature can be explained by the fact that heat is released by a partial reaction between the granulating components. By determining the degree of conservation described further below, it can be concluded that this degree of reaction when using SKS-6 and sodium bicarbonate is between 5 and 60%.

The invention also relates to the use of the granular detergent builder according to the invention in detergents and cleaning agents.

The above-mentioned detergents and cleaning agents preferably contain 3 to 60% by weight of the granular detergent builder.

The detergents and cleaning agents can additionally contain other detergent builders and other detergent auxiliaries.

The other detergent builders are preferably sodium tripolyphosphate, zeolite A, zeolite P, amorphous silicates, water glass and / or alkali metal carbonates.

The other detergent ingredients are preferably surfactants, bleaches, bleach activators, bleach stabilizers, enzymes, polycarboxylates and / or carboxyl-containing cobuilders.

The analysis data of the cogranulates according to the invention were determined using the following test methods.

Average particle diameter (d ₅₀ )

The particle size distribution is determined on the basis of a 50 gram sample by sieve analysis (apparatus used: RETSCH VIBRATONIC) and the mean particle diameter is determined from this by means of a graphic evaluation.

Decay kinetics

The granules to be examined are sieved in the sample preparation via a sieve (710 µm). The undersize is used to determine the kinetics of decay in water (18 ° dH) with a MICROTRAC Series 9200 (Leeds & Nothrup GmbH).

Bulk density

wobei folgende Abkürzungen gelten:

m₀ =

Masse des leeren Meßbechers in Gramm

m_P =

Masse des mit Produkt gefüllten Meßbechers in Gramm

V =

Volumen des Meßbechers in Milliliter

A device that meets the requirements of DIN 53466 is used to determine the bulk density. The mass in grams is determined, which takes up the volume of one milliliter under specified conditions. The process is applicable to free flowing powders as well as substances that are in granular form. The bulk density is then calculated using the following formula: $${\text{Bulk density = (m}}_{\text{P}}{\text{- m}}_{\text{0}}\text{) / V}$$

the following abbreviations apply:

m ₀ =

Mass of the empty measuring cup in grams

m _P =

Mass of the measuring cup filled with product in grams

V =

Volume of the measuring cup in milliliters

PH value

The pH value is measured in a 1% solution in distilled water at 20 ° C with a digital pH meter CG 840 from SCHOTT.

Degree of conservation

In the course of the compacting, a more or less pronounced chemical reaction can occur between the granulating components. The degree of preservation provides information about what percentage of the starting components are present side by side in an unreacted form. The temperature increase is determined which is achieved by the amount of heat released and the corresponding heat of solution when 25 grams of the cogranulate sample to be measured are added to 100 grams of distilled water. The degree of maintenance is related to the temperature increase of the zero value, which is achieved if instead of the cogranulate, only a corresponding physical mixture of the starting components is used in the determination. The degree of conservation is calculated as follows: $$\text{Degree of conservation [\%] =}\frac{\text{Temperature difference of the cogranulate * 100\%}\hfill }{\text{Temperature difference of the zero value}\hfill }$$

Calcium binding capacity

15 grams or 30 grams of a calcium solution (131.17 g CaCl ₂ * 2H ₂ O are dissolved in distilled water and made up to 5000 ml) are made up to 999 grams with distilled water. The result is a solution with 15 ° or 30 ° dH. The solution is kept in a water bath thermostat (ERWEKA) with stirring at 20 ° C. and 1 gram of the cogranulate sample to be measured is added. With an automatic titrator (from SCHOTT), the solution is kept constant at pH = 10 for 10 minutes at 20 ° C. with intensive stirring. The sample is then filtered through a folded filter (Ederol 12). If the sample to be examined contains carbonate, the filtrate must be made strongly acidic (pH <2.5) due to possible reprecipitation with HCl, so that the excess carbonate in the form of CO ₂ can be removed from the filtrate by stirring. The calcium remaining in the filtrate is then determined complexometrically. The calcium binding capacity, generally referred to as the KBV value, was calculated by forming the difference with the original calcium content.

Magnesium binding capacity

50 grams of a magnesium solution (10.88 g MgCl ₂ * 6H ₂ O are dissolved in distilled water and made up to 5000 ml) are made up to 999 grams with distilled water.

The result is a solution with 3 ° dH. The solution is kept in a water bath thermostat (ERWEKA) with stirring at 20 ° C. and 1 gram of the cogranulate sample to be measured is added. With an automatic titrator (from SCHOTT), the solution is kept constant at pH = 10 for 10 minutes at 20 ° C. with intensive stirring. The sample is then filtered through a folded filter (Ederol 12). If the sample to be examined contains carbonate, the filtrate must be made strongly acidic (pH <2.5) due to possible precipitation with HCl, so that the excess carbonate in the form of CO ₂ can be removed from the filtrate by stirring. The magnesium remaining in the filtrate is then determined complexometrically. The magnesium binding capacity was calculated by forming the difference with the original magnesium content.

Example 1 (comparative example)

90 kg of sodium bicarbonate were pressed on a compactor (Bepex GmbH) with a roller diameter of 200 mm at a line pressure of 20 to 30 kN / cm and then ground to a granulate with d ₅₀ = 775 μm.
The granules were examined for the grain distribution, the decay kinetics, the bulk density, the pH value as well as for the calcium and magnesium binding capacity.
The compacting data are shown in Table 1, the determined test results in Table 2.

Example 2 (comparative example)

90 kg of sodium disilicate (= SKS-6®) consisting predominantly of δ-Na ₂ Si ₂ O _{5 was} pressed in the same way as in Example 1 and ground into granules with d ₅₀ = 782 μm. The granules were examined as indicated in Example 1.
The compacting data are shown in Table 1, the determined test results in Table 2.

Example 3 (according to the invention)

45 kg of sodium hydrogen carbonate and 45 kg of SKS-6® were premixed in an EIRICH mixer. The premix was pressed in the same way as in Example 1 and ground into granules with d ₅₀ = 783 μm. The granules were examined as indicated in Example 1. The degree of conservation was also determined.
The compacting data are shown in Table 1, the determined test results in Table 2.

Example 4 (according to the invention)

63 kg sodium hydrogen carbonate and 27 kg SKS-6® were premixed in an EIRICH mixer. The premix was pressed analogously to Example 1 and ground to a granulate with d ₅₀ = 703 μm. The granules were examined as indicated in Example 3.
The compacting data are shown in Table 1, the determined test results in Table 2.

Example 5 (according to the invention)

81 kg of sodium hydrogen carbonate and 9 kg of SKS-6® were premixed in an EIRICH mixer. The premix was pressed in the same way as in Example 1 and ground into granules with d ₅₀ = 739 μm. The granules were examined as indicated in Example 3.
The compacting data are shown in Table 1, the determined test results in Table 2. Table 1 Compacting data SKS-6® / NaHCO ₃ - cogranulates example Compactor pressure [kN / cm] Speed hammer mill [rpm] Initial temperature [° C] School pent temperature [° C] 1 25th 700 22 39 2nd 30th 700 22 45 3rd 24th 700 22 52 4th 24th 700 22 50 5 24th 700 22 49 Analysis data SKS-6® / NaHCO ₃ - cogranulates example 1 2nd 3rd 4th 5 Degree of conservation [%] ------ ------ 90.4 69 50.6 CaBV (1g / l) 30 ° dH 204.2 80.2 190.4 204 204.1 CaBV (1g / l) 15 ° dH 98.7 64.6 92.9 97.4 98.4 MgBV (1g / l) 3 ° dH 0 11.6 10.9 8.7 6.5 PH value 8.2 12.5 9.9 9.5 8.5 Grain spectrum [%]> 1180 µm 3.4 5.5 2.9 2.2 2.4 [%]> 710 µm 54.1 52.6 55.8 47 49.8 [%]> 425 µm 28.5 24.8 27.4 30.7 29.9 [%]> 212 µm 11.4 11.4 10.4 15 14.3 [%]> 150 µm 0.5 0.3 0.5 0.9 0.9 [%]> 53 µm 1.6 1.7 1.8 3.2 2.4 [%] <53 µm 0.5 3.7 1.2 1 0.3 Bulk density [g / l] 1010 845 910 940 983 Decay kinetics d ₅₀ [µm] after 1 min 0 10.5 10.2 11.3 11 d ₅₀ [µm] after 2 min 0 9.6 9.5 10.2 10th d ₅₀ [µm] after 4 min 0 9.2 8.7 9.1 8.8 d ₅₀ [µm] after 6 min 0 8.9 8.2 8.4 8.1 d ₅₀ [µm] after 8 min 0 8.7 7.9 8th 7.7 d ₅₀ [µm] after 10 min 0 8.6 7.7 7.6 7.3

Claims (12)

Granular detergent builder in the form of a cogranulate from a mixture of sodium hydrogen carbonate and crystalline phyllosilicates of the general formula NaMSi _x O _{2x + 1} * yH ₂ O, where M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20, characterized in that a) the granular detergent builder contains 5 to 50% by weight of crystalline layered silicate and 50 to 95% by weight of sodium hydrogen carbonate; b) has a pH of ≦ 10 in 1% solution in distilled water; c) has a calcium binding capacity of ≧ 150 mg Ca / g (30 ° dH) and a magnesium binding capacity of ≧ 4 mg Mg / g (3 ° dH) and d) has a bulk density of ≧ 850 g / l. Granular detergent builder according to claim 1, characterized in that it has a bulk density of ≧ 900 g / l. Granular detergent builder according to claim 1 or 2, characterized in that the reaction between crystalline layered silicate and sodium hydrogen carbonate is between 5 and 60%. Granular detergent builder according to at least one of Claims 1 to 3, characterized in that the crystalline sodium silicate has an SiO ₂ / Na ₂ O ratio of (1.9 to 2.1): 1. Process for producing a granular detergent builder in the form of a cogranulate from a mixture of sodium hydrogen carbonate and crystalline phyllosilicates of the general formula NaMSi _x O _{2x + 1} * yH ₂ O, where M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20, which is characterized in that sodium bicarbonate and sodium silicate are mixed together in powder form; that the mixture is fed to a zone in which it is compacted under pressure between two rollers rotating in opposite directions to form a solid (Schulpen); that the solid is crushed and that one finally separates the desired grain sizes from oversize and undersize. A method according to claim 5, characterized in that the pressure of the rolls corresponds to a line pressing force> 20 kN / cm at 200 mm roll diameter. A method according to claim 5 or 6, characterized in that the school pen has a temperature of ≦ 70 ° C. Use of the granular detergent builder according to one of claims 1 to 4 or produced according to one of claims 5 to 7 in detergents and cleaning agents. Detergent and cleaning agent containing 3 to 60% by weight of the granular detergent builder of claims 1 to 4 or produced according to one of claims 5 to 7. Detergent and cleaning agent according to claim 9, characterized in that it additionally contains other detergent builders and other detergent adjuvants. Detergent and cleaning agent according to claim 10, characterized in that the other detergent builders are sodium tripolyphosphate, zeolite A, zeolite P, amorphous silicates, water glass and / or alkali metal carbonates. Detergent and cleaning agent according to claim 10 or 11, characterized in that the other detergent ingredients are surfactants, bleaching agents, bleach activators, bleach stabilizers, enzymes, polycarboxylates and / or carboxyl-containing cobuilders.