EP0758372A1 - Process for producing silicate-like builder granulates of high bulk density - Google Patents

Abstract

PCT No. PCT/EP95/01543 Sec. 371 Date Nov. 1, 1996 Sec. 102(e) Date Nov. 1, 1996 PCT Filed Apr. 24, 1995 PCT Pub. No. WO95/29978 PCT Pub. Date Nov. 9, 1995A process for producing silicate or silicate-containing builder granules having an apparent density of at least 600 g/l by compacting silicate materials having an apparent density of less than 500 g/l, a molar ratio of SiO2 to Na2O of 1.3 to 4, and a water content of up to 15% by weight, wherein the silicate materials are X-ray amorphous and are present in the form of a fine particle solid having a flake structure.

Description

 "Process for the production of silicate builder granules with increased

Bulk density "

The invention relates to a method for producing silicate or silicate-containing builder granules with bulk densities of at least 600 g / l, which have improved application properties, and detergents or cleaning agents which contain such granules.

More recently, purely silicate systems, such as the crystalline layered disilicates - or combinations of such components with other ingredients of detergents or cleaning agents for use as builders or co-builders, have been described. Reference should also be made to combinations of sodium carbonates and sodium lates as disclosed in European patent applications EP-A-0488868 and EP-A-0561 656.

From US Pat. Nos. 3,912,649, 3,956,467, 3,838,193 and 3,879,527, amorphous sodium silicate compounds are known as builder substances, which are obtained by spray drying aqueous water glass solutions, whereby light silicates are obtained, followed by grinding and subsequent compacting and rounding with additional removal of water from the ground material ¬ be made, cf. see, for example, FIG. 3 of US 3,912,649. The water content of the products used is approx. 18 to 20% by weight with bulk densities well above 500 g / 1.

From the European patent application EP-A-0444415 amorphous low-sodium disilate with a water content of 0.3 to 6 wt .-% are known. The amorphous sodium disilicate should preferably contain 0.5 to 2% by weight of water. These highly dewatered amorphous disilicates are produced in a multi-stage process, which initially involves the production of a powder

REPLACEMENT BLAπ (RULE 26) Amorphous sodium silicate with a water content of 15 to 23% by weight. This material is treated in a rotary tube furnace with flue gas at temperatures of 250 to 500 ° C in countercurrent. The amorphous sodium silicate emerging from the rotary kiln is comminuted to grain sizes of 0.1 to 12 mm with the aid of a mechanical crusher and then ground to a grain size of 2 to 400 μm with a mill.

European patent EP-B-0374017 describes customary water-containing silicates in granular form with high density, which contain 1 to 10% by weight of cellulose derivatives, which improves the dissolution rate of the compressed granules. No statements are made in this document about the secondary washing ability and in particular about the incrustation inhibition.

According to the teaching of European patent application EP-A-0 542 131, a sodium silicate containing water of crystallization can be prepared by treating a 40 to 60% strength by weight aqueous solution of the sodium silicate with hot air in a turbo dryer equipped with percussion tools. The drying product passes through a pseudoplastic state with a free water content of 5 to 12% by weight, based on the mass, which is used to form a product in granular form. The drying of these granules is carried out under working conditions which preclude embrittlement of the granule outer shell and the associated breakage of the granule structure. In this way it is possible - while avoiding the so-called "popcorn effect" - to produce water-soluble sodium silicates with specific weights in the range between 0.5 and 1.2, which are characterized by complete solubility in water at ambient temperature.

The older German patent application P 4400024.3 describes sodium silicates in the module range (molar ratio SiO 2 / Na 2 O) from 1.3 to 4 in the form of a finely divided solid in a cullet structure, these silicates being X-ray amorphous and having an absolute water content of at most 15% by weight (over-dried Silicates) and bulk densities below 500 g / 1. Draw in the process these X-ray amorphous silicates are characterized in particular by the presence of microcrystalline solid regions which can be determined by means of electron diffraction, but not by means of X-ray diffraction. Due to their body structure, these silicates have a very high specific BET surface area. The particle sizes are preferably in a range from 10 to 200 μm. From an application point of view, those silicates which have a bulk density below 400 g / 1 and in particular in the range from 100 to 350 g / 1 are particularly advantageous.

Roll compacting of detergents or cleaning agents or individual components of detergents or cleaning agents is a state of the art. It is already known from European patent application EP-A-0253323 that builders such as zeolite and / or phosphate can be converted into granules with high bulk density and very good application properties by roller compaction. The conditions under which roller compaction is usually carried out are described in detail in this prior art document. It is stated that the pressing pressure in the nip and the duration of the material in the area of the pressing pressure are to be set in such a way that a well-formed band of high density is produced. The high degree of compaction is desirable not only with regard to modern washing or cleaning agents with a high bulk density, but also with regard to an increased abrasion resistance of the granules. However, it must be taken into account that excessive pressures impair the process reliability, since when they are used the material is plasticized on the rollers and can lead to sticking. This undesirable effect occurs when an increase in the pressing pressure no longer causes further compression of the material and the additional force that is now added predominantly causes the heating and plasticization of the material - for example, due to partial melting of water-containing components. This is also the reason why roller compacting is usually carried out at temperatures which are not additionally increased externally, but at ambient temperature. The task was to produce silicate or silicate-containing builders for use in modern washing or cleaning agents which, despite their compression, still have very good secondary washing performance, particularly in the area of incrustation inhibition.

Accordingly, the invention relates in a first embodiment to a process for the preparation of silicate-containing or silicate-containing builder granules by compacting light silicates with bulk densities of less than 500 g / l, sodium silicates in the module range (molar ratio SiO 2 / Na 2 O) from 1.3 to 4 are used, which are in the form of a finely divided solid in a cullet structure, are X-ray amorphous and have an absolute water content of at most 15% by weight, and are adjusted to densities of at least 600 g / l by the compression.

The granules according to the invention result from compacting, all known methods for compacting being available. However, the roller compaction of silicates with preferably modules between 1.5 and 3.3, in particular between 1.7 and 3.0, for example around 2.0, is particularly preferred according to the older German patent application P 44 00 024.3. It is possible that the compaction is carried out partially or entirely by roller compaction. In a preferred embodiment of the invention, the light starting silicates are produced in a turbo dryer / granulator. Silicates which have been dried to a water content of from 0 to a maximum of 15% by weight, preferably from 3 to 15 and in particular from 6 to 13% by weight, and in particular Schütt¬, are particularly preferred in this case by means of a single or multiple, repeated drying step have weights below 400 g / 1. Depending on the setting of the blade position and the air throughput through the turbo dryer, bulk densities between 40 g / 1 and approximately 400 g / 1 can be obtained, ie, especially with high liter weights, the turbo dryer works not only as a dryer but also as a mill. In order to keep the compression ratio low, higher liter weights of the starting material to be compacted are preferred. An increase in the liter weights of very light products can be in the Turbo dryers, for example, also take place in a downstream mill or other intermediate compacting stages.

It is thus possible and entirely preferred to comminute light silicates with bulk densities of 40 to 150 g / 1 in a mill to a bulk density of 350 to 400 g / 1 and to pre-compact them at the same time. Both crushed and non-crushed over-dried silicates can be used for compacting, whereby crushed silicates have advantages in processing to the compact due to the low compression ratio.

The bulk density of the granules compacted according to the invention is then preferably even 700 g / 1 to 1100 g / 1 and in particular even 800 to 1000 g / 1. In a preferred embodiment of the invention, a bulk density of the compacted silicates is set which is preferably at least twice and in particular at least three times the bulk density of the light starting silicates. The water content of the compacted silicates is 0 to a maximum of 15% by weight. However, as with the light starting silicates, preferred water contents are 3 to 15% by weight and in particular 6 to 13% by weight.

Surprisingly, these compacted silicates show not only an equally good, but even an improved ability to inhibit incrustation than the relatively light starting silicates, although the surface of the compacted granules is less than that of the starting silicates, which were in the form of broken glass. The "information" of the incrustation inhibition, which was inherent in the light and fine-particle silicates in the broken glass structure, is not only not destroyed by the compacting, but is transmitted and preferably even amplified.

The builder granules produced according to the invention can consist entirely of the optionally water-containing compacted silicates, but they can also contain further components, in particular those which are known as customary ingredients of detergents or cleaning agents. A preferred embodiment of the invention provides that silicate-containing or silicate-containing builder granules are prepared, water-containing silicates being used in an amount of from 10 to 100% by weight, preferably from 30 to 100% by weight and in particular at least 45% by weight. It is irrelevant whether the silicate starting materials, which are produced according to the older German patent application P 4400024.3 and then co-compacted, already contain these additional components or whether mixtures of the individual components and the relatively light starting silicates are first produced and compacted. In a preferred embodiment, mixtures of silicates and carbonates in a weight ratio of 9: 1 to 1: 9 are used.

Other common ingredients of detergents or cleaning agents include, in particular, anionic and nonionic surfactants, but also other inorganic and organic builder substances, as well as bleaching agents and bleach activators, inorganic salts, enzymes and enzyme stabilizers and foam inhibitors, graying inhibitors and color transfer inhibitors dress.

Preferred surfactants of the sulfonate type are the known C9-C13-alkylbenzenesulfonates, α-olefin sulfonates and alkanesulfonates. Also suitable are esters of α-sulfo fatty acids or the disalts of α-sulfo fatty acids. Other suitable anionic surfactants are sulfonated fatty acid glycerol esters, which are mono-, di- and triesters and their mixtures, such as those produced by esterification by a monoglycerol with 1 to 3 mol of fatty acid or in the transesterification of triglycerides with 0.3 to 2 Moles of glycerol can be obtained.

Particularly suitable alkyl sulfates are the sulfuric acid monoesters of the Ci2-Ci8 fatty alcohols, such as lauryl, myristyl, cetyl or stearyl alcohol, and the fatty alcohol mixtures obtained from coconut oil, palm and palm kernel oil, which additionally contain fractions of unsaturated alcohols, e.g. of oleyl alcohol.

SPARE BLADE (RULE 26) In addition to the anionic surfactants, soaps are particularly suitable. Saturated fatty acid soaps are suitable, such as the salts of lauric acid, myristic acid, palmitic acid, stearic acid, hydrogenated erucic acid and behenic acid, and in particular soap mixtures derived from natural fatty acids, for example coconut, palm kernel or tallow fatty acids.

The anionic surfactants can be present in the form of their sodium, potassium or ammonium salts and as soluble salts of organic bases, such as mono-, di- or triethanola in. The anionic surfactants are preferably in the form of their sodium or potassium salts, in particular in the form of the sodium salts.

The nonionic surfactants used are preferably alkoxylated, advantageously ethoxylated, in particular primary, alcohols, preferably having 8 to 18 carbon atoms and an average of 1 to 12 moles of ethylene oxide (EO) per mole of alcohol, in which the alcohol radical is linear or preferably in the 2-position May be methyl-branched or may contain linear and methyl-branched radicals in the mixture, as are usually present in oxo alcohol radicals. However, alcohol ethoxylates with linear residues of alcohols of native origin with 12 to 18 carbon atoms, for example from coconut, palm, tallow fat or oleyl alcohol, and an average of 2 to 8 EO per mole of alcohol are preferred. The preferred ethoxylated alcohols include, for example, Ci2-Ci4 alcohols with 3 EO or 4 EO, Cg-Cn alcohol with 7 EO, Ci3-Cχ5 alcohols with 3 EO, 5 EO, 7 EO or 8 EO, Ci2- Ci8 alcohols with 3 EO, 5 EO or 7 EO and mixtures thereof, such as mixtures of Ci2-Ci4 alcohol with 3 EO and Ci2-Ci8 alcohol with 5 EO. The degrees of ethoxylation given represent statistical averages, which can be an integer or a fraction for a specific product. Preferred alcohol ethoxylates have a narrow homolog distribution (narrow range ethoxylates, NRE). In addition to these nonionic surfactants, fatty alcohols with more than 12 EO can also be used. Examples of this are tallow fatty alcohol with 14 EO, 25 EO, 30 EO or 40 EO. In addition, alkyl glycosides of the general formula R0 (G) _x , in which R is a primary straight-chain or methyl-branched, in particular methyl-branched aliphatic radical having 8 to 22, preferably 12 to 18, C., can also be used as further nonionic surfactants -Atoms means and G is the symbol which stands for a glycose unit with 5 or 6 carbon atoms, preferably for glucose. The degree of oligomerization x, which indicates the distribution of monoglycosides and oligoglycosides, is any number between 1 and 10; x is preferably 1.2 to 1.4.

Another class of preferably used nonionic surfactants, which are used either as the sole nonionic surfactant or in combination with other nonionic surfactants, in particular together with alkoxylated fatty alcohols, are alkoxylated, preferably ethoxylated or ethoxylated and propoxylated, fatty acid alkyl esters, preferably with 1 to 4 Carbon atoms in the alkyl chain, in particular fatty acid methyl esters, as described, for example, in Japanese patent application JP 58/217598 or which are preferably prepared by the process described in international patent application WO-A-90/13533.

Nonionic surfactants of the amine oxide type, for example N-coconut alkyl, N, N-dimethylamine oxide and N-tallow alkyl-N, N-dihydroxyethylamine oxide, and the fatty acid alkanolamides can also be suitable. The amount of these nonionic surfactants is preferably not more than that of the ethoxylated fatty alcohols, in particular not more than half of them.

Other suitable surfactants are polyhydroxy fatty acid amides of the formula (I),

R3

I.

R2-C0-N- [Z] (I)

in R2C0 for an aliphatic acyl radical with 6 to 22 carbon atoms, R ³ for hydrogen, an alkyl or hydroxyalkyl radical with 1 to 4 carbon atoms and [Z] for a linear or branched polyhydroxyalkyl radical

REPLACEMENT SHEET (REG & 26) with 3 to 10 carbon atoms and 3 to 10 hydroxyl groups. The polyhydroxy fatty acid amides are known substances which can usually be obtained by reductive amination of a reducing sugar with ammonia, an alkylamine or an alkanolamine and subsequent acylation with a fatty acid, a fatty acid alkyl ester or a fatty acid chloride.

For example, finely crystalline, synthetic and bound water-containing zeolite can be used as additional builder substances. Suitable is primarily zeolite NaA, but also zeolite P and mixtures of A, X and / or P. Suitable substitutes or partial substitutes for zeolites are crystalline, layered sodium silicates of the general formula Na Si _x θ2 + yH2θ, where M Sodium or hydrogen means x is a number from 1.9 to 4 and y is a number from 0 to 20 and preferred values for x are 2, 3 or 4. Such crystalline layered silicates are described, for example, in European patent application EP-A-0 164 514. Preferred crystalline layered silicates are those in which M represents sodium and x assumes the values 2 or 3. In particular, both β- and fr-sodium disilicate Na2Si2θ5 * yH2θ are preferred, wherein β-sodium disilicate can be obtained, for example, by the method described in international patent application WO-A-91/08171.

In a preferred embodiment of the invention, however, the granules produced according to the invention contain a maximum of 50% by weight, based on the total of zeolite, X-ray amorphous and crystalline layered silicates, of zeolite and crystalline layered silicates.

Usable organic builders are, for example, the polycarboxylic acids preferably used in the form of their sodium salts, such as citric acid, adipic acid, succinic acid, glutaric acid, tartaric acid, sugar acids, amino carboxylic acids, nitrilotriacetic acid (NTA), provided that such use is not objectionable for ecological reasons, and mixtures from these. Preferred salts are the salts of polycarboxylic acids such as citric acid, Adipic acid, succinic acid, glutaric acid, tartaric acid, sugar acids and mixtures thereof.

Suitable polymeric polycarboxylates are, for example, the sodium salts of polyacrylic acid or polymethacrylic acid, for example those with a relative molecular weight of 800 to 150,000 (based on acid). Suitable copolymeric polycarboxylates are, in particular, those of acrylic acid with methacrylic acid and of acrylic acid or methacrylic acid with maleic acid. Copolymers of acrylic acid with maleic acid which contain 50 to 90% by weight of acrylic acid and 50 to 10% by weight of maleic acid have proven to be particularly suitable. Their relative molecular weight, based on free acids, is generally 5,000 to 200,000, preferably 10,000 to 120,000 and in particular 50,000 to 100,000. Terpolymers are also particularly preferred, for example those which, as monomeric salts of acrylic acid and maleic acid, are also preferred Contain vinyl alcohol or vinyl alcohol derivatives (DE 4300772) or the monomers as salts of acrylic acid and 2-alkylallylsulfonic acid and sugar derivatives (DE 4221 381).

Other suitable builder systems are oxidation products of carboxyl group-containing polyglucosans and / or their water-soluble salts, as described, for example, in international patent application W0-A-93/08251 or their production, for example, in international patent application W0-A- 93/16110 or the older German patent application P 4330393.0 is described.

In addition, components can be used in the process that have a positive influence on the oil and fat washability from textiles. This effect is particularly evident when a textile is soiled that has already been washed several times beforehand with a detergent according to the invention which contains this oil and fat-dissolving component. The preferred oil- and fat-dissolving components include, for example, nonionic cellulose ethers such as methyl cellulose and in particular methyl hydroxypropyl cellulose with a proportion of methoxyl groups of 15 to 30% by weight and of hydroxypropoxyl groups of 1 to 15% by weight in each case Based on the nonionic cellulose ethers, and the polymers of phthalic acid and / or terephthalic acid or their derivatives known from the prior art, in particular polymers of ethylene terephthalates and / or polyethylene glycol terephthalates or anionically and / or nonionically modified derivatives thereof.

In addition, constituents can be used in the process which further improve the solubility of the compacted and easily soluble granules. Such constituents are described, for example, in the international patent application WO-A-93/02176 and the German patent application DE 4203031. The preferred ingredients include, in particular, fatty alcohols with 10 to 80 moles of ethylene oxide per mole of fatty alcohol, for example tallow fatty alcohol with 30 E0 and tallow alcohol with 40 E0, and polyethylene glycols with a relative molecular weight between 200 and 2000.

Further suitable ingredients of the granules produced according to the invention are water-soluble inorganic salts such as bicarbonates, carbonates, customary amorphous silicates or mixtures of these. According to the teaching of the older German patent application P 43 19578.4, alkali metal carbonates can also be replaced by sulfur-free, 2 to 11 carbon atoms and, if appropriate, a further carboxyl and / or amino group having amino acids and / or their salts. In the context of this invention, it is preferred that the alkali metal carbonates are partially or completely replaced by glycine or glycinate.

Among the compounds which provide H2O2 in water and which serve as bleaching agents, sodium perborate tetrahydrate and sodium perborate monohydrate are of particular importance. Further usable bleaching agents are, for example, sodium percarbonate, peroxypyrophosphates, citrate perhydrates and H2O2-delivering peracidic salts or peracids, such as perbenzoates, peroxophthalates, diperazelaic acid or diperdodecanedioic acid.

SPARE BLADE (RULE 26) In order to achieve an improved bleaching effect when washing at temperatures of 60 ° C. and below, bleach activators can, if desired, also be incorporated into the granules. Examples of this are N-acyl or O-acyl compounds which form organic peracids with H2O2, preferably N.N'-tetraacylated diamines, p- (alkanoyloxy) benzenesulfonate, also carboxylic acid anhydrides and esters of polyols such as glucose pentaacetate. Further known bleach activators are acetylated mixtures of sorbitol and mannitol, as described, for example, in European patent application EP-A-0 525 239. Particularly preferred bleach activators are N, N, N '.N'-tetraacetylethylenediamine (TAED), 1,5-diacetyl-2,4-dioxo-hexa- hydro-1,3,5-triazine (DADHT) and acetylated sorbitol mannitol Mixes (SORMAN).

When used in machine washing processes, it can be advantageous to add conventional foam inhibitors to the granules. Suitable foam inhibitors are, for example, soaps of natural or synthetic origin, which have a high proportion of Ci8-C24 fatty acids. Suitable non-surfactant-like foam inhibitors are, for example, organopolysiloxanes and their mixtures with microfine, optionally silanized silica, and paraffins, waxes, microcrystalline waxes and their mixtures with silanized silica or bistearylethylenediamine. Mixtures of different foam inhibitors are also used with advantages, e.g. those made of silicones, paraffins or waxes. The foam inhibitors, in particular silicone or paraffin-containing foam inhibitors, are preferably bound to a granular, water-soluble or dispersible carrier substance. Mixtures of paraffins and bistearylethylenediaids are particularly preferred. In a preferred embodiment, however, silicate-containing granules not produced according to the invention do not contain these foam inhibitors, but if appropriate they are already contained in the detergents or cleaners in which the granules according to the invention are preferably used.

Suitable enzymes are those from the class of proteases, lipases, amylases, cellulases or mixtures thereof. Are particularly well suited Strains of bacteria or fungi, such as Bacillus subtilis, Bacillus licheniformis and Streptomyces griseus, are enzymatic active ingredients obtained. Proteases of the subtilisin type and in particular proteases which are obtained from Bacillus lentus are preferably used. Enzyme mixtures, for example of protease and amylase or protease and lipase or protease and cellulase or of cellulase and lipase or of protease, amylase and lipase or protease, lipase and cellulase, but in particular mixtures containing cellulase, are of particular interest. Peroxidases or oxidases have also proven to be suitable in some cases. The enzymes can be adsorbed on carriers and / or embedded in Hü11 substances to protect them against premature decomposition. The proportion of the enzymes, enzyme mixtures or enzyme granules can be, for example, about 0.1 to 5% by weight, preferably 0.1 to about 2% by weight.

The salts of polyphosphonic acids, in particular 1-hydroxyethane-l. L-diphosphonic acid (HEDP), diethylenetriaminepentamethylenephosphonic acid (DETPMP) or ethylenediaminetetramethylenephosphonic acid are suitable as stabilizers, in particular for per compounds and enzymes.

Graying inhibitors have the task of keeping the dirt detached from the fiber suspended in the liquor and thus preventing graying. Water-soluble colloids of mostly organic nature are suitable for this, for example the water-soluble salts of polymeric carboxylic acids, glue, gelatin, salts of ether carboxylic acids or ether sulfonic acids of starch or cellulose or salts of acidic sulfuric acid esters of cellulose or starch. Water-soluble polyamides containing acidic groups are also suitable for this purpose. Soluble starch preparations and starch products other than those mentioned above can also be used, for example degraded starch, aldehyde starches, etc. Polyvinylpyrrolidone can also be used. However, cellulose ethers such as carboxymethyl cellulose (sodium salt), methyl cellulose, hydroxyalkyl cellulose and mixed ethers such as methyl hydroxyethyl cellulose, methyl hydroxypropyl cellulose, methyl carboxymethyl cellulose and mixtures thereof, and also polyvinylpyrrolidone, for example in amounts of 0.1 to 5% by weight, are preferred on the means. The granules produced according to the invention can contain derivatives of diaminostilbenedisulfonic acid or their alkali metal salts as optical brighteners. Suitable are, for example, salts of 4,4'-bis (2-anilino-4-morpholino-l, 3,5-triazinyl-6-amino) stilbene-2,2'-disulfonic acid or compounds of similar structure which instead of the morpholino- Group carry a diethanolamino group, a methylamino group, an anilino group or a 2-methoxyethylamino group. Brighteners of the substituted diphenylstyryl type may also be present, for example the alkali metal salts of 4,4'-bis (2-sulfostyryl) diphenyl, 4,4'-bis (4-chloro-3-sulfostyryl) diphenyl , or 4- (4-chlorostyryl) -4 '- (2-sulfostyryl) diphenyl. Mixtures of the aforementioned brighteners can also be used.

In a particularly advantageous embodiment of the invention, however, heavy silicate or silicate-containing builder granules are produced which have a bulk density of at least 850 g / l. In particular, these are builder granules which consist of 100% by weight, where appropriate, water-containing silicates with a modulus of 1.7 to 3.0, water contents of 3 to 15% by weight and in particular of 6 to 13% by weight. % are preferred.

The bulk densities can be set by one or more compression steps, and - as stated above - a first compression step can also be carried out by comminution. In particular, it is preferred that bulk densities of 800 g / l and above, based on silicates in a cullet structure with bulk weights below 200 g / l, are set by 2 or 3 compression steps.

In a preferred embodiment of the invention, the relatively light starting silicates are fed directly to a roller pressing without prior precompaction. The pair of rollers can be arranged in any spatial direction, in particular thus vertically or horizontally to one another. The mixture to be compacted or the only relatively light silicate starting material is then either filled by gravity or by means of a suitable device, for example one Darning screw, fed to the nip. The material to be compacted is then guided under pressing force through the gap of a pair of two rollers running in opposite directions at approximately the same rotational speed and compacted to form a plate-like or band-shaped material to be pressed, which is also referred to as a sling band. The pressing force is generally between 7 and 30 kN / cm roll length and in particular between 10 and 25 kN / cm roll length. The silicate starting materials used according to the invention or the silicate-containing starting materials or mixtures, in particular when the silicates have a water content of at least 6% by weight, based on the silicates, can be roller-compacted in dry form. Only in the case of silicates free of water of hydration can a small amount of water be added, depending on the nature of the further raw materials. However, it is preferred to carry out the roller compaction without adding water.

It has been found that the roller compaction carried out according to the invention can be carried out not only without problems at higher temperatures, but also that this elevated temperature improves the dissolving behavior of the roller-compacted builder granules in particular if, in addition to amorphous or X-ray amorphous silicates, they also contain crystalline layered silicates contain. Roll temperatures of 35 to 120 ° C. are possible, with temperatures of 40 and 100 ° C. and in particular between 45 to 90 ° C. being particularly preferred.

The shoulder strap is then subjected to a comminution process. This comminution or grinding can take place, for example, in a mill. This creates so-called chip granules, which can also be ground more finely. The comminuted material is then expediently fed to a screening process, in which coarse material is separated off and returned to the comminution device, while material which is too fine is again fed to the compacting in the nip with further starting materials. The sliver belt is preferably made by conventional grinding into granules with a particle size range from 0.05 mm to about 2 mm, preferably with a particle size range that is at least 70% by weight

ERSATZBLATJ (REGEL26) Granules with a particle diameter between 0.1 and 1.6 mm exist, adjusted, while fine-grain fractions with grain diameters below 0.05 mm are returned to the compacting and coarse fractions with granule diameters above 2 are returned to the grinding. If desired or necessary, the roller-compacted granules can also be fed to a total of one or more further compression steps, which do not have to consist solely in roller compacting again, but can also be carried out by other known compacting measures. However, it is preferred that further compacting steps are carried out by means of a roller.

The silicate-containing builder granules produced according to the invention, which preferably have up to 90% by weight of further customary ingredients of detergents or cleaning agents, can already be used as detergents or cleaning agents. However, the silicate-containing or silicate-containing builder granules produced according to the invention can also serve as an admixture component with all modern washing or cleaning agents. These means are also the subject of this application. Granular detergents or cleaning agents which have bulk densities of at least 600 g / 1, preferably at least 700 g / 1 and in particular at least 750 g / 1 are particularly preferred. The agents preferably contain biodegradable surfactants, for example fatty alkyl sulfates and / or ethoxylated fatty alcohols and / or soaps and / or alkyl polyglycosides, and optionally as cobuilders, biodegradable polymers. These agents can be made by any of the known manufacturing processes including extrusion, granulation and mixing technology.

example

A 50 wt .-% aqueous sodium silicate solution with a weight ratio Na2θ: Siθ2 of 1: 2.0 was dried in a turbo dryer / granulator from Vomm, Italy, at a wall temperature of 170 ° C with hot air of 220 ° C in two stages . The silicate product of the first drying stage had a residual water content of 17% by weight and a bulk density of 850 g / 1, after passing through the second drying stage a residual water content of 9% by weight was achieved with a bulk weight of 130 g / 1. The silicate was in X-ray amorphous form and had the typical body structure described in the older German patent application P 4400024.3. The silicate was compacted in three stages at a pressing force of 17 kN / cm. The resulting slugs were each crushed through a 2 mm sieve. The bulk weight of the silicate was 900 g / 1.

The application technology ^• Investigation for incrustation inhibition of the light starting silicate (130 g / 1) and the silicate according to the invention (900 g / 1) was carried out in a test apparatus which consisted of a stainless steel container with a capacity of 10 1, which was equipped with a heating element rod, as used in drum washing machines, was heated. In each cycle, 10 l of silicate solution, which contained 16.7 g of the respective silicate, were circulated in this container using a propeller stirrer and heated to 90 ° C. within half an hour and kept at 90 ° C. for a further half hour ( The time-temperature curve thus corresponded to a normal cook wash program). The hot silicate solution was then drained off and the container was briefly rinsed with 5 l of cold water before the next cycle was started. After the 5th cycle, the heating element was removed from the container and first heated to 80 ° C. in aqueous citric acid to remove the precipitates. The detachment of the precipitates was then completed within 30 minutes after alkalizing the solution with sodium hydroxide and adding nitrilotriacetic acid sodium salt. The CaO content in the solution was determined directly by means of optical emission spectrometry (ICP-0C). The liquid sample was evaporated and excited in a gas ionized by high frequency. to Tap water was used to prepare the silicate solution and to rinse the container, which had been adjusted to a content of 30 ° d with a calcium: magnesium ratio of 5: 1 by adding calcium and magnesium chloride.

The calcium deposits on the heating element were 322 mg CaO for the light starting silicate and 56 mg CaO for the silicate according to the invention.

For comparison:

Portil (R) A (spray-dried sodium water glass of module 2 and glow loss (800 ° C) approx. 18%; commercial product of the applicant, Germany) showed calcium deposits on the heating rod of 280 mg CaO in this test. SKS-6 ( ^R ) (crystalline layered sodium disilicate; commercial product of Hoechst AG, Germany) obtained 92 mg CaO under these conditions.

Claims

Claims

1. Process for the production of heavy silicate or silicate-containing builder granules by compacting light silicates with bulk densities of less than 500 g / 1, sodium silicates in the module range (molar ratio SiO 2 / Na 2 O) of 1.3 to 4 being used in the form of a finely divided solid in a cullet structure are present, are X-ray amorphous and have an absolute water content of at most 15% by weight, and bulk densities of at least 600 g / l are set by compression.

2. The method according to claim 1, characterized in that bulk weights are set with values around 700 to 1100 g / 1, preferably around 800 to 1000 g / 1.

3. The method according to claim 1 or 2, characterized in that the compression is carried out partially or entirely by roller compaction.

4. The method according to any one of claims 1 to 3, characterized in that first a crushing and simultaneous pre-compression takes place before a roller compaction is carried out.

5. The method according to any one of claims 1 to 4, characterized in that finely divided solids in cullet structure with bulk densities below 400 g / 1 are used as the starting silicates, the water content of both the starting silicates and the compacted silicates being 3 to 15% by weight. %, preferably 6 to 13 wt .-%.

6. The method according to any one of claims 1 to 5, characterized in that optionally water-containing silicates at 10 to 100 wt .-%, preferably 30 to 100 wt .-% and in particular at least 45 wt .-%, each based be used on the co-compacted granules, the usual components of detergents or cleaning agents being considered as further components.

7. The method according to any one of claims 1 to 6, characterized in that a bulk density of the compacted granules is set that is at least twice, preferably at least three times as high as the bulk density of the starting silicates.

8. The method according to any one of claims 1 to 5 or 7, characterized gekennzeich¬ net that heavy silicate builder granules are produced which have a bulk density of at least 850 g / 1 and from 100 wt .-% optionally water-containing silicates with a module of 1 , 7 to 3.0 exist.

9. The method according to any one of claims 1 to 8, characterized in that bulk densities of 800 g / 1 and above, based on silicates in cullet structure with bulk weights below 200 g / 1, are adjusted by 2 or 3 compression steps.

10. The method according to any one of claims 1 to 9, characterized in that the roller compacting takes place at elevated temperatures of 35 to 120 ° C, preferably from 40 to 100 ° C and in particular between 45 and 90 ° C.

11. The method according to any one of claims 1 to 10, characterized in that the roller compacting is carried out without the addition of water.

12. The method according to any one of claims 1 to 11, characterized in that the Schülpenband obtained by roller compacting a Zer¬ reduction process, preferably a mill, is fed.

13. washing or cleaning agent containing silicate or silicate-containing builder granules according to one of claims 1 to 12.