CA2315889A1 - Prevention of deposits - Google Patents

Abstract

The present invention provides a composition that prevents deposits on heating rods during the machine washing of textiles. Said composition comprises in one embodiment a laundry detergent or cleaning product comprising a polycarboxylate having a molecular mass of less than 4000 g/mol as measured by means of GPC
against a polyacrylate standard. In another embodiment it comprises a coarse-particled laundry detergent or cleaning product or compound therefor having an average particle size of between 0.2 and 4.0 mm, which comprises a polymeric polycarboxylate having a molecular mass of less than 1000 g/mol as measured by means of GPC against a polyacrylate standard.

Description

PREVENTION OF DEPOSITS
Field of the Invention The present invention relates to a composition which prevents deposits on heating rods during the machine washing of textiles.
Background of the Invention Deposits on heating rods consist primarily of calcium and magnesium compounds and also, when using certain laundry detergents containing silicate and zeolite, of smaller amounts of silicatic and aluminosilicatic deposits. These deposits come about in particular because of the hardness of the water used.
The major constituents of the hardness in water are salts of calcium and magnesium, especially the chlorides, sulfates and bicarbonates, which are referred to as so-called hardness formers. Since under heat the bicarbonates are converted into carbonates, a fraction of the calcium salts is precipitated as CaC03, whose solubility is low, when washing at elevated temperatures. At high magnesium concentrations, basic magnesium carbonates are also precipitated. If the laundry detergents used themselves comprise carbonate, in the form, for example, of alkali metal carbonates or of precursors which release carbonate during the wash process, such as percarbonates, for example, then this carbonate content further promotes the formation of insoluble calcium and magnesium carbonate residues on the heating rods. Especially in regions of high water hardness, i.e., water hardness of more than 140 mg of calcium oxide per liter (14°d - 14 degrees on the German hardness scale), deposits of this kind on heating rods constitute a great problem.

Complexing agents have been added to laundry detergents and cleaning products in an attempt to prevent the deposition of such compounds.
Although substances such as ethylenediaminetetraacetate (EDTA) and nitrilotriacetate (NTA) are highly suited to this purpose, their high heavy metal binding capacity means that they are undesirable on ecological grounds.
The use in larger amounts of phosphates or phosphonates, such as hydroxyethanediphosphonic acid and its salts, for example, is also ruled out by ecological concerns.
Furthermore, copolymers of acrylic and malefic acid, as well, are used in order to disperse calcium carbonate in the wash liquor. For example, European Patent EP-B-628627 proposes a water softener in tablet form that is intended for use in addition to a laundry detergent or cleaning product. Said water softener consists of from 60 to 98~ by weight of a combination of citrate/citric acid and a water softening polymer, plus polyethylene glycol and other auxiliaries. The polymer is either a peptide-based biodegradable polymer or a malefic acid-acrylic acid copolymer, e.g., Sokalan CP5.
German Laid-Open Specification DE 2240309 describes a composition containing from 5 to 40~ by weight of surfactant, from 30 to 70~ by weight of alkali metal carbonate, from 1 to 30~ by weight of complexing agent, preferably citrate, and from 0.05 to 15~ by weight of an antideposition agent for calcium carbonate. Said antideposition agent is alternatively a phosphate, a phosphonic acid, or a polymeric carboxylate.
European Patent Application EP-A-869169 describes a laundry detergent containing from 5 to 80~ by weight of sodium carbonate, from 5 to 24% by weight of surfactant, and from 0.5 to 25% by weight of a maleate copolymer having a molecular mass of between 500 and 7000 g/mol and consisting to the extent of at least 50%
by weight of maleate units, at least 70 mol% of which are neutralized, and from 10 to 50 mol% of acrylate units, as well as from 1 to 10 mol% of nonionic comonomers. This specific copolymer is used first to improve the wash performance and second to prevent the deposition of hardness formers on the laundry.
References to its effect on heating rod deposits are absent from the document, however.
The patent application WO 93/05133 proposes preventing encrustation by using a composition which contains no polycarboxylates. The formation of calcium carbonate is prevented by delaying the availability of the alkali metal carbonate present in the laundry detergent or cleaning product. This can be done by adding it later or by treating the alkali metal carbonate with, for example, a silicate coating, which reduces the dissolution rate of the alkali metal carbonate.
The laundry detergent compositions of European Patent EP-B-572288 contain from 10 to 30% by weight of alkali metal carbonate, from 2 to 10% by weight of an amorphous aluminosilicate, and from 3 to 15% by weight of a growth inhibitor for calcium carbonate crystals, which may comprise polyaspartic acid, a phosphonic acid, a copolymeric polycarboxylate having a molecular mass of between 50,000 and 70,000 g/mol, or a polyacrylate having a molecular mass of from 2 to 10,000 g/mol, citrate, or other carboxylic acids. Key to the action of this composition is the function of the amorphous aluminosilicate as a host lattice for calcium-containing deposits.

European Patent Application EP-A-130640 describes a laundry detergent composition comprising besides surfactants and phosphate-free builder substances from 0.3 to 5% by weight of a polyacrylate polymer of this kind having a molecular mass of between 2000 and 10,000 g/mol. This composition possesses particular advantages in the removal of clay soiling from the laundry. The compositions contain from 5 to 80% by weight of builder substances, which may be selected from a broad spectrum of organic and inorganic compounds. In particular, zeolites, carboxylates, carbonates, and alkali metal silicates are mentioned here. There are no references in the document to the effect that the polymers prevent the formation of deposits on heating rods.
A laundry detergent builder whose advantages include inhibiting deposits on heating rods is described in DE 3715051. It comprises a silicate, which binds calcium ions, and also a mixture of two different acrylic acid polymers having different viscosity numbers. Said mixture may comprise two homopolymers, one homopolymer and one copolymer of acrylic acid (at least 50 mol%) with monomers of other ethylenically unsaturated dicarboxylic acids (C3_g), for example, methacrylic acid, itaconic acid or malefic acid, or else two copolymers. In a proportion of up to 20 mol% the copolymers may include carboxyl-free ethylenically unsaturated monomers.
The earlier German Patent Application DE 19858888.7 describes a process for preventing deposits on heating rods during the machine washing of textiles, said process taking place using water of any desired hardness and a water softener whose principal inorganic constituents comprise crystalline aluminosilicate and alkali metal carbonate. A polymeric polycarboxylate having a molecular mass of less than 10,000 g/mol is used as encrustation inhibitor.
Su~nary of the Invention It has now been found that certain polymeric polycarboxylates are especially suitable for reducing the formation of residues on heating rods.
This invention firstly provides, accordingly, a laundry detergent or cleaning product apt to prevent deposits on heating rods, comprising a polycarboxylate having a molecular mass of less than 4000 g/mol as measured by means of GPC against a polyacrylate standard.
The present invention secondly provides a coarse-particled laundry detergent or cleaning product or compound therefor having an average particle size of between 0.2 and 4.0 mm, apt to prevent deposits on heating rods, which comprises a polymeric polycarboxylate having a molecular mass of less than 10,000 g/mol as measured by means of GPC against a polyacrylate standard.
The present invention further provides a process for preventing deposits on heating rods during the machine washing of textiles, using water of any desired hardness and a water softener whose principal inorganic constituents comprise crystalline aluminosilicate and alkali metal carbonate, wherein a polymeric polycarboxylate having a molecular mass of less than 4000 g/mol as measured by means of GPC against a polyacrylate standard is used as encrustation inhibitor.
Accordingly, the present invention additionally provides for the use of polymeric polycarboxylates having a molecular mass of less than 4000 g/mol as measured by means of GPC against a polyacrylate standard for preventing deposits on heating rods during the machine washing of textiles.
The molecular masses reported in this document for polymeric polycarboxylates are weight-average molecular masses Mw, determined basically by means of gel permeation chromatography (GPC) using a W detector.
The measurement was made against an external polyacrylate standard, which owing to its structural similarity to the polymers under investigation provides realistic molecular weight values. These figures differ markedly from the molecular weight values obtained using polystyrenesulfonic acids as the standard. The molecular masses measured against polystyrenesulfonic acids are generally higher than the molecular masses reported in this document.
Detailed Description of the Invention In accordance with the invention, the polymeric polycarboxylate is preferably a polyacrylate, in particular a homopolymeric polyacrylate. Particularly preferred polycarboxylates have a molecular mass of less than 3500 g/mol, preferably between 3500 and 1500 g/mol, and with particular preference between 3000 and 2000 g/mol as measured by means of GPC against a polyacrylate standard. These polymeric polycarboxylates of the invention are frequently referred to below simply as the polycarboxylates. That designation in the text below means, specifically, the polymers of the invention.
In accordance with the invention, said polycarboxylate may also comprise copolymeric polycarboxylates, especially those of acrylic acid with methacrylic acid and of acrylic acid or methacrylic acid with malefic acid. Copolymers which have been found particularly suitable are those of acrylic acid with malefic acid, containing from 50 to 90% by weight of acrylic acid and from 50 to 10% by weight of malefic acid. To improve the solubility in water, the polymers may also include allylsulfonic acids as monomers, such as allyloxy-benzenesulfonic acid and methallylsulfonic acid, for example. Particular preference is also given to biodegradable polymers of more than two different monomer units, for example, those whose monomers comprise salts of acrylic acid and of malefic acid and also vinyl alcohol and/or vinyl alcohol derivatives, or salts of acrylic acid and of 2-alkylallylsulfonic acid, and also sugar derivatives. Further preferred copolymers are those comprising as monomers preferably acrolein and acrylic acid/acrylic acid salts or acrolein and vinyl acetate.
The polycarboxylates of the invention are preferably in neutralized form; that is, they have been neutralized to the extent of, preferably, at least 70 mol%. The carboxylates are preferably in the form of their alkali metal salts, in particular in the form of the sodium salts. In specific embodiments, however, it may also be preferable for the polymers to be in their acid form, i.e., with a degree of neutralization of less than 50 mol%, preferably less than 30 mol%.
It is additionally preferred if these polycarboxylates have a narrow molecular mass distribution. A narrow molecular mass distribution in this respect means that there are markedly preferred chain lengths and that the distribution curve falls off sharply either side of this maximum. Particularly narrow molecular mass distributions show a steep drop in this respect. The molecular mass distribution may be measured as the ratio formed from the weight-average molecular mass MW
and the number-average molecular mass Mn of the polymers. This ratio constitutes a measure of the uniformity or polydispersity, and is larger the wider the molecular mass distribution. Defined molecular compounds possess a ratio MW/Mn = 1. Polymers, in contrast, normally have ratios MW/Mn of considerably greater than 1, it being entirely possible for industrial polymers to have values of considerably greater than 10. The polymers of the invention, however, preferably possess a ratio Mw/Mn of less than 10, usually markedly less than 10. Polymers preferred in accordance with the invention even have a ratio MW/Mn of less than 8, in particular even less than 5. In a likewise preferred embodiment, the polymers have a ratio of less than 2, and, especially if the polymers have been prepared by means of a living addition polymerization, they may also have a ratio of less than 1.5. In another preferred embodiment, the polymers have a ratio MW/Mn from the range from 2 to 7. In accordance with the invention, all molecular mass distributions for which the ratio MW/Mn < 10 are labeled narrow.
The compositions of the invention comprising such polycarboxylates show significantly lower deposits on heating rods than comparable compositions comprising other polymeric builders, especially those comprising as sole polymeric polycarboxylate a copolymer of acrylic acid with malefic acid having a molecular mass of more than 20,000 g/mol. The wash properties of laundry detergents comprising the polymers of the invention are entirely comparable with the properties of laundry detergents comprising said copolymer; in the case of specific types of soiling, the compositions of the invention in fact give better results.
The compositions of the invention may be in solid or liquid form, although it is preferred if the compositions are in solid form. The solid compositions may take on any desired form. This may embrace compositions in powder or granule form as well as tablets. The tablets may have virtually any desired three-dimensional shape and size. Suitable three-dimensional shapes include virtually any practicable designs - i.e., for example, bar, rod or ingot forms, cubes, blocks and corresponding three-dimensional elements having planar side faces, and, in particular, cylindrical designs with a circular or oval cross section. This latter design covers forms ranging from tablets through to compact cylinders having a height-to-diameter ratio of greater than 1.
The solid compositions of the invention may have any desired bulk densities. The pallet of possible bulk densities ranges from low bulk densities below 600 g/1, for example, 300 g/1, via the range of medium bulk densities from 600 to 750 g/l, through to the high bulk density range of at least 750 g/1. In one preferred variant of the compositions of the invention with high bulk densities, however, the bulk density is even above 800 g/1, with bulk densities of more than 850 g/1 possibly being particularly advantageous.
In one preferred embodiment, the compositions of the invention comprise coarse-particle laundry detergents or cleaning products or compounds therefor, having an average particle size of between 0.2 and 4.0 mm and comprising a polymeric polycarboxylate having a molecular mass of less than 10,000 g/mol as measured by means of GPC against a polyacrylate standard.
Especially when this coarse-particle laundry detergent or cleaning product or compound therefor has been prepared from a premix that already includes the polymeric polycarboxylate having a molecular mass of less than 10,000 g/mol, the effect according to the invention is found even with polymeric polycarboxylates having molecular masses of less than 10,000 g/mol. In one preferred embodiment, this coarse-particle laundry detergent or cleaning product or compound therefor comprises a polymeric polycarboxylate having a molecular mass of less than 8000 g/mol, in particular a molecular mass from the range from 3000 to 8000 and, with particular preference, from the range from 4000 to 5000 g/mol as measured by means of GPC against a polyacrylate standard. In another, particularly preferred embodiment, however, the compositions comprise specifically the polycarboxylates with molecular masses of less than 4000 g/mol that were described earlier on above. In that case the effect according to the invention is particularly strongly pronounced.
The coarse-particled compositions have preferred bulk densities of more than 600 g/1, in particular more than 700 g/1. In one particularly preferred embodiment, the bulk densities are between 750 and 1000 g/1. The average particle sizes of these coarse-particled compositions are in the range from 0.2 to 4.0 mm, the average particle sizes in preferred embodiments being between 0.8 and 3.0 mm, in particular between 1.0 and 2.0 mm. In one preferred embodiment, these compositions comprise compositions prepared from a solid premix which comprises individual raw materials and/or compounded components which are present as solids at room temperature under a pressure of 1 bar and have a melting point or softening point of not below 45°C, and further comprises, if desired, up to 10~ by weight of nonionic surfactants which are liquid at temperatures below 45°C under a pressure of 1 bar, said premix being essentially free from water and comprising at least one raw material or compounded component which is in solid form under a pressure of 1 bar and at temperatures below 45°C but under the premix processing conditions is in the form of a melt that acts as a polyfunctional, water-soluble binder that during the preparation of the compositions performs the function both of a lubricant and of an adhesive for the solid laundry detergents or cleaning products but has a disintegrating action when the composition is redissolved in an aqueous liquor. In one preferred embodiment, these coarse-particled compositions of the invention comprise compacted forms, especially extrudates.
In one preferred embodiment of the invention, the coarse-particled compositions are prepared by extrusion, as described, for example, in European Patent EP-B-486592 or in International Patent Applications WO 93/02176 and WO 94/09111 or WO 98/12299. Here, a solid premix is extruded under pressure in the form of a strand and the strand, following its emergence from the die plate, is cut to the predeterminable granule dimensions by means of a pelletizer. The homogeneous and solid premix comprises a plasticizer and/or lubricant, the effect of which is that the premix, under the pressure or under the application of specific energy, softens plastically and becomes extrudable. Preferred plasticizers and/or lubricants are surfactants and/or polymers.
As regards explaining the actual extrusion process, reference is hereby made specifically to the abovementioned patents and patent applications. In one preferred embodiment of the invention, the premix is preferably supplied continuously to a planetary roll extruder or a twin-screw extruder with co- or counter-rotating screws, whose barrel and whose extruder-pelletizing die may be heated to the predetermined extrusion temperature. Under the shear effect of the extruder screws, the premix - under pressure, preferably at least 25 bar but possibly below this level at extremely high throughputs, depending on the apparatus used - is compacted, plasticated, extruded in the form of fine strands through the perforated die plate in the extruder head, and finally comminuted by means of a rotary chopping knife, to give, preferably, approximately spherical to cylindrical granules. The perforation diameter of the perforated die plate and the strand cutting length are tailored to the chosen granule dimensions. In this embodiment, it is possible to prepare granules of an essentially uniformly predeterminable particle size, it being possible specifically to adapt the absolute particle sizes to the intended application. In general, particle diameters of up to a maximum of 0.8 cm are preferred.
Important embodiments provide here for the preparation of uniform granules in the millimeter range, for example, in the range from 0.5 to 5 mm, and in particular in the range from about 0.8 to 3 mm. The length/diameter ratio of the chopped primary granules in one important embodiment is in the range from approximately 1:1 to approximately 3:1. It is further preferred to transfer the still plastic primary granules to a further shaping step; here, edges on the raw extrudate are rounded off, thus making it possible to obtain, ultimately, extrudate granules which are spherical to approximately spherical in shape. If desired, small amounts of dry powder, for example, zeolite powders such as zeolite NaA powder, may also be used at this stage. This shaping operation may be carried out in commercial rounding devices. It is important to ensure that only small amounts of fine particle fraction are formed in this stage. Subsequent drying, which is described as a preferred embodiment in the abovementioned prior art documents, is possible but not mandatory in accordance with the invention. It may be specifically preferred to carry out no drying following the compacting step.
Alternatively, extrusion/compression operations may be conducted in low-pressure extruders, in the Kahl press (from Amandus Kahl) or in the Bextruder from Bepex.
In one particularly preferred embodiment, the invention envisages the temperature regime in the transition zone of the screw, the manifold and the die plate being such that the melting point of the binder, or the upper limit of the melting range of the binder, is at least reached and, preferably, is exceeded. The duration of the temperature exposure in the compression zone of the extrusion is preferably less than 2 minutes and in particular in a range between 30 seconds and 1 minute.
The actual compaction process takes place preferably at temperatures which at least in the compaction step correspond at least to the temperature of the softening point, if not indeed to the temperature of the melting point, of the binder. In one preferred embodiment of the invention, the process temperature is significantly above the melting point, or above the temperature at which the binder is in melt form. In particular, however, it is preferred for the process temperature in the compaction step to be not more than 20°C above the melting point, or the upper limit of the melting range, of the binder. Although in technical terms it is entirely possible to set even higher temperatures, it has been found that a temperature difference from the melting point or softening temperature of the binder of 20°C is generally entirely adequate and that higher temperatures bring about no additional advantages.
Consequently, not least for reasons of energy, it is particularly preferred to operate certainly above but at least as close as possible to the melting point or to the upper temperature limit of the melting range of the binder. A temperature regime of this kind possesses the further advantage that it allows heat-sensitive raw materials, for example, peroxy bleaches such as perborate and/or percarbonate, and also enzymes, to be processed increasingly without serious losses of active substance. The possibility of precise temperature control of the binder, especially in the decisive step of compaction, i.e., between the mixing/homogenizing of the premix and the shaping operation, permits a process regime which is very favorable from an energy standpoint and also extremely gentle for the heat-sensitive constituents of the premix, since the premix is exposed to the higher temperatures only for a short time. In preferred press agglomeration processes, the working tools of the press agglomerator (the screws) of the extruder, the rolls) of the roll compactor, and the rolls) of the pellet press) have a temperature of not more than 150°C, preferably not more than 100°C, and in particular not more than 75°C, and the process temperature is not more than 30°C, and in particular not more than 20°C, above the melting temperature or the upper temperature limit of the melting range of the binder. Preferably, the duration of temperature exposure in the compression zone of the press agglomerators is not more than 2 minutes and is in particular in a range between 30 seconds and 1 minute.
Preferred binders, which may be used alone or in a mixture with other binders, are polyethylene glycols, 1,2-polypropylene glycols, and modified polyethylene glycols and polypropylene glycols. Modified polyalkylene glycols include in particular the sulfates and/or the disul.fates of polyethylene glycols or polypropylene glycols having a relative molecular mass of between 600 and 12,000 and in particular between 1000 and 4000. A further group consists of mono- and/or disuccinates of the polyalkylene glycols, which in turn have relative molecular masses of between 600 and 6000, preferably between 1000 and 4000. For a more precise description of the modified polyalkylene glycol ethers, reference is made to the disclosure content of International Patent Application WO-A-93/02176. In the context of this invention, polyethylene glycols include those polymers prepared using not only ethylene glycol but also C3-CS glycols and also glycerol and mixtures of these as starting molecules. Also embraced are ethoxylated derivatives such as trimethylolpropane containing from 5 to 30 EO. The polyethylene glycols used with preference may have a linear or branched structure, particular preference being given to linear polyethylene glycols. The particularly preferred polyethylene glycols include those having relative molecular masses of between 2000 and 12,000, advantageously around 4000, it being possible to use polyethylene glycols having relative molecular masses of less than 3500 and above 5000 in particular in combination with polyethylene glycols having a relative molecular mass of around 4000, and such combinations advantageously comprising more than 50~ by weight, based on the overall amount of the polyethylene glycols, of polyethylene glycols having a relative molecular mass of between 3500 and 5000. The binders used may also, however, include polyethylene glycols which per se are in the liquid state at room temperature under a pressure of 1 bar; this is a reference in particular to polyethylene glycol having a relative molecular mass of 200, 400, and 600. However, these inherently liquid polyethylene glycols should be used only in a mixture with at least one further binder, which mixture must in turn satisfy the requirements of the invention - that is, it must have a melting point or softening point of at least above 45°C.

Further suitable binders include low molecular mass polyvinylpyrrolidones and derivatives thereof having relative molecular masses of up to a maximum of 30,000.
Preference is given here to relative molecular mass ranges between 3000 and 30,000, for example, around 10,000. Polyvinylpyrrolidones are preferably used not as sole binders but instead in combination with others, especially in combination with polyethylene glycols.
Further binders which have been found suitable are raw materials having detersive properties, i.e., for example, nonionic surfactants having melting points of at least 45°C or mixtures of nonionic surfactants and other binders. Preferred nonionic surfactants include alkoxylated fatty alcohols or oxo alcohols, especially C12-C1$ alcohols. In this context, degrees of alkoxylation, especially degrees of ethoxylation, of on average from 18 to 80 AO, in particular EO, per mole of alcohol and mixtures thereof have proven particularly advantageous. In particular, fatty alcohols containing on average from 18 to 35 EO, especially those containing on average from 20 to 25 EO, exhibit advantageous binder properties in the sense of the present invention. If desired, binder mixtures may also include ethoxylated alcohols containing on average fewer EO units per mole of alcohol, for example, tallow fatty alcohol containing 14 EO. However, it is preferred to use these alcohols having relatively low degrees of ethoxylation only in the form of a mixture with alcohols having higher degrees of ethoxylation.
Advantageously, the amount of these alcohols having relatively low degrees of ethoxylation in the binders is less than 50~ by weight, in particular less than 40°s by weight, based on the overall amount of binder employed. In particular, nonionic surfactants commonly used in laundry detergents or cleaning products, such as C12-C1a alcohols having on average from 3 to 7 EO, which are inherently liquid at room temperature, are preferably present in the binder mixtures only in amounts so as to provide less than 2~ by weight of these nonionic surfactants, based on the process end product. As already described above, however, it is less preferred to use nonionic surfactants which are liquid at room temperature in the binder mixtures. In one particularly advantageous embodiment, however, such nonionic surfactants are not included in the binder mixture, since they not only reduce the softening point of the mixture but may also contribute to tackiness in the end product and, furthermore, fail to satisfactorily meet the requirement of rapid dissolution of the binder/partition wall in the end product, owing to their tendency to cause gelling on contact with water. Similarly, it is not preferred for anionic surfactants or their precursors, the anionic surfactant acids, commonly used in laundry detergent or cleaning products to be present in the binder mixture .
Other nonionic surfactants suitable as binders are the fatty acid methyl ester ethoxylates, which have no gelling tendency, especially those containing on average from 10 to 25 EO (for a more detailed description of this group of substances, see below).
Particularly preferred representatives of this group of substances are methyl esters based predominantly on Cls-C1$ fatty acids, for example, hydrogenated beef tallow methyl ester containing on average 12 EO or containing on average 20 EO. In one preferred embodiment of the invention, the binder used is a mixture comprising Clz-Cl8 fatty alcohol based on coconut or tallow containing on average 20 EO and polyethylene glycol having a relative molecular mass of from 400 to 4000. In another preferred embodiment of the invention, the binder used is a mixture which comprises methyl esters based predominantly on C16-C1$ fatty acids and containing on average from 10 to 25 EO, especially hydrogenated beef tallow methyl ester containing on average 12 EO or on average 20 EO, and a C12-C18 fatty alcohol based on coconut or tallow containing on average 20 EO and/or polyethylene glycol having a relative molecular mass of from 400 to 4000.
Embodiments of the invention that have proven particularly advantageous are binders based, alternatively, solely on polyethylene glycols having a relative molecular mass of around 4000, or on a mixture of C12-C1$ fatty alcohol based on coconut or tallow and containing on average 20 EO, and one of the above-described fatty acid methyl ester ethoxylates, or on a mixture of C12-C18 fatty alcohol based on coconut or tallow and containing on average ~20 EO, one of the above-described fatty acid methyl ester ethoxylates, and a polyethylene glycol, especially one having a relative molecular mass of around 4000.
In small amounts, further suitable substances in addition to those mentioned above may also be present in the binder.
The composition or process of the invention may be used with water of any desired hardness. The major constituents of water hardness are salts of calcium and magnesium, especially chlorides, sulfates, and bicarbonates. Since under heat the bicarbonates are converted into carbonates, when the water is heated some of the calcium salts are precipitated in the form of CaC03, whose solubility is poor. At very high magnesium concentrations, basic magnesium carbonates may also be precipitated. The hardness or total hardness of the water is understood as referring to the alkaline earth metal ion content. To characterize a water, and its hardness, the concept of degree of hardness was introduced (°d, formerly °dH [German hardness]): 1°d corresponds (per liter) to 10.00 mg of Ca0 or 7.19 mg of MgO. It is also customary to state the number of millimoles per liter (mmol/1). In this case, the following ranges of hardness are distinguished:
1 soft < 7°d < 1.3 mmol/1 2 moderately hard 7-14°d 1.3-2.5 mmol/1 3 hard 14-21°d 2.5-3.8 mmol/1 4 very hard > 21°d > 3.8 mmol/1 The harder the water used, the greater, generally, the tendency to form deposits on heating rods. Accordingly, the composition or process of the invention is used preferably with hard or very hard water, i.e., water having a hardness of at least 14°d; however, the advantages of the composition or process are also evident even with soft and moderately hard water.
In the process which comprises the washing of textiles, the use of a laundry detergent as well is preferred. It may be preferable for the polymeric polycarboxylate and the water softener to be present in the laundry detergent, the polymer being used preferably in amounts of from 0.1 to 15% by weight, in particular from 0.5 to 10, and with particular preference from 2 to 5% by weight, and no other, separate water-softening agent being used.
In an alternative process, which is likewise in accordance with the invention, the polymeric poly-carboxylate is present in a separately added water softener, which preferably also comprises the inorganic softener constituents used in the process, and is preferably dosed such that, based on the additionally used laundry detergent, the polycarboxylate is used in amounts of from 0.1 to 15% by weight, in particular from 0.5 to 10, and with particular preference from 2 to 5% by weight. The polymer may be added at the same time as the laundry detergent. Alternatively, the polymer may be added prior to the addition of the laundry detergent, such that the laundry detergent is added subsequently to water pretreated with the polymer. It is also conceivable for the polymers to be added to the wash liquor after the laundry detergent has been added, but with this subsequent dosing taking place before the wash liquor is heated.
In accordance with the invention, in the process, inorganic constituents are used for water softening.
These constituents comprise, in particular, crystalline aluminosilicates and alkali metal carbonates. The invention, accordingly, further provides a water softener comprising a) from 0.1 to 30% by weight of polymeric polycarboxylate having a molecular mass of less than 4000 g/mol as measured by means of GPC
against polyacrylate standard, b) from 1 to 60% by weight of zeolite, and c) from 1 to 60% by weight of alkali metal carbonate, the sum of the constituents a), b) and c) making up at least 90% by weight of the overall water softener.
In a preferred composition, the water softener comprises component a) in amounts of from 0.5 to 15% by weight, in particular from 2 to 10% by weight, and component b) in amounts of from 10 to 50% by weight, in particular from 15 to 45% by weight, and component c) in amounts of from 10 to 50% by weight, in particular from 15 to 45% by weight, based in each case on the overall water softener.
Preferred crystalline aluminosilicates are the zeolites A, P, X and Y. Also suitable, however, are mixtures of A, X, Y and/or P. As zeolite P, particular preference is given, for example, to zeolite MAP (for example, Doucil A24~; commercial product from Crosfield). Also of particular interest is a cocrystallized sodium/potassium aluminum silicate comprising zeolite A
and zeolite X, which is available commercially as VEGOBOND AX~ (commercial product from Condea Augusta S.p.A.). The zeolite may be used as a spray-dried powder or else as an undried, stabilized suspension still wet from its preparation. Where the zeolite is used as a suspension, the suspension may include small additions of nonionic surfactants as stabilizers, for example, from 1 to 3% by weight, based on zeolite, of ethoxylated C12-Cla fatty alcohols having 2 to 5 ethylene oxide groups, C1z-C14 fatty alcohols having 4 to 5 ethylene oxide groups, or ethoxylated isotridecanols. Appropriate zeolites have an average particle size of less than 10 ~m (volume distribution;
measurement method: Coulter counter) and contain preferably from 10 to 22% by weight, in particular from 15 to 22% by weight, of bound water. In one preferred embodiment of the process, laundry detergents are used which comprise at least part of the crystalline aluminosilicate in the form of zeolite A. In another advantageous embodiment, at least part of the zeolite used, preferably at least 20% by weight, comprises faujasite-type zeolite. In the context of the present invention, the term "faujasite-type zeolite"
characterizes all three zeolites which form the faujasite subgroup of zeolite structural group 4. As well as zeolite X, therefore, it is possible in accordance with the invention to use zeolite Y and faujasite and also mixtures of these compounds, preference being given to straight zeolite X.
The alkali metal carbonates comprise preferably sodium and/or potassium carbonate, the use of sodium carbonate being preferred in particular. Alkali metal carbonate need not necessarily be used directly but may also be provided by precursors which do not form alkali metal carbonate until during the process. In this respect mention may be made, in particular, of alkali metal percarbonate, which releases alkali metal carbonate under the influence of moisture. Preferred in accordance with the invention is the conjoint use of zeolite and sodium carbonate, the weight ratio in which the crystalline aluminosilicate and the alkali metal carbonate are used being in the range from 1:5 to 5:1, with particular preference in the range from 1:2 to 2:1. It may be preferable for the compositions to comprise alkali metal carbonate in at least the same amount as crystalline aluminosilicates, since compositions of this kind possess advantages in their graying inhibitor activity, have been found from experience to have a higher bulk density, and in addition exhibit a greater alkali reserve.
Furthermore, the compositions of the invention and, respectively, the laundry detergents or water softeners used in the process may comprise further builder substances.
In particular, in addition to the polycarboxylate, they may also comprise the copolymeric polycarboxylates that are commonly employed as cobuilders, especially those of acrylic acid with methacrylic acid and of acrylic acid or methacrylic acid with malefic acid. Copolymers which have been found particularly suitable are those of acrylic acid with malefic acid, containing from 50 to 90% by weight of acrylic acid and from 50 to 10% by weight of malefic acid. Their relative molecular mass is generally from 2000 to 70,000 g/mol, preferably from 20,000 to 50,000 g/mol, and in particular from 30,000 to 40,000 g/mol. To improve the solubility in water, the polymers may also comprise allylsulfonic acids as monomers, such as, for example, in EP-B-727448, allyloxybenzenesulfonic acid and methallylsulfonic acid. Particular preference is also given to biodegradable polymers comprising more than two different monomer units, for example, those which in accordance with DE-A-43 00 772 comprise as monomers salts of acrylic acid and of malefic acid and also vinyl alcohol and/or vinyl alcohol derivatives or those which, in accordance with DE-C-42 21 381, comprise as monomers salts of acrylic acid and of 2-alkylallyl-sulfonic acid, and also sugar derivatives. Further preferred copolymers are those described in German Patent Applications DE-A-43 03 320 and DE-A-44 17 734 and comprising as monomers preferably acrolein and acrylic acid/acrylic acid salts or acrolein and vinyl acetate. In one preferred variant, both these copolymers and the polycarboxylates that are essential to the invention are present, the ratio of the polycarboxylate to the acrylic acid/maleic acid copolymer being in the range from 2:1 to 1:20, preferably from 1:1 to 1:15. The polymer content in the compositions overall is preferably from 0.5 to 20% by weight, in particular from 2 to 10% by weight. In another, likewise preferred embodiment of the invention, the process uses no polymer of acrylic acid other than the polycarboxylate of the invention, and in particular uses no copolymer of acrylic acid with malefic acid either.
In addition to the substances already mentioned, the compositions used in the process of the invention, especially the laundry detergent, may comprise further ingredients. Mention may be made here, for example, of further builder substances, which are preferably present, however, only in smaller amounts than the abovementioned inorganic builders - zeolites and alkali metal carbonates.
Mention may be made here of crystalline, layer-form sodium silicates of the general formula NaMSiX02X+l~YHa~, where M is sodium or hydrogen, x is a number from 1.9 to 4, y is a number from 0 to 20, and preferred values for x are 2, 3 or 4. Crystalline phyllosilicates of this kind are described, for example, in European Patent Application EP-A-0 164 514. Preferred crystalline phyllosilicates of the stated formula are those where M is sodium and x adopts the value 2 or 3.
In particular, both (3- and 8-sodium disilicates Na2Si205~yHz0 are preferred.
Furthermore, it is also possible to use amorphous sodium silicates having an Na20:Si02 modulus of from 1:2 to 1:3.3, preferably from 1:2 to 1:2.8, and in particular from 1:2 to 1:2.6, which are dissolution-retarded and have secondary detergency properties, as builders. The retarded dissolution relative to conventional amorphous sodium silicates may have been brought about in a variety of ways - for example, by surface treatment, compounding, compacting, or overdrying. In the context of this invention, the term "amorphous" also embraces "X-ray-amorphous". This means that in X-ray diffraction experiments the silicates do not yield the sharp X-ray reflections typical of crystalline substances but instead yield at best one or more maxima of the scattered X-radiation, having a width of several degree units of the diffraction angle.
However, good builder properties, even particularly good builder properties, may well result if the silicate particles in electron diffraction experiments yield vague or even sharp diffraction maxima. The interpretation of this is that the products have microcrystalline regions with a size of from 10 to several hundred nm, values up to max. 50 nm and in particular up to max. 20 nm being preferred. So-called X-ray-amorphous silicates of this kind, which likewise possess retarded dissolution relative to the conventional waterglasses, are described, for example, in German Patent Application DE-A-44 00 024. Particular preference is given to compacted amorphous silicates, compounded amorphous silicates, and overdried X-ray-amorphous silicates.
Of course, the widely known phosphates may also be used as builder substances, provided such a use is not to be avoided on ecological grounds. Particularly suitable are the sodium salts of the orthophosphates, of the pyrophosphates and, in particular, of the tripolyphosphates.
In other, likewise preferred embodiments of the invention, the compositions may comprise builder systems which are substantially free from crystalline aluminosilicates. These may, preferably, be builder systems whose principal inorganic constituents comprise sodium carbonate and alkali metal silicates.
Organic builder substances which may be used are, for example, the polycarboxylic acids, usable in the form of their sodium salts, the term polycarboxylic acids meaning those carboxylic acids which carry more than one acid function. Examples of these are citric acid, adipic acid, succinic acid, glutaric acid, malic acid, tartaric acid, malefic acid, fumaric acid, sugar acids, amino carboxylic acids, nitrilotriacetic acid (NTA), provided such use is not objectionable on ecological grounds, and also mixtures of these. Preferred salts are the salts of the polycarboxylic acids such as citric acid, adipic acid, succinic acid, glutaric acid, tartaric acid, sugar acids, and mixtures thereof.

The acids per se may also be used. In addition to their builder effect, the acids typically also possess the property of an acidifying component and thus also serve to establish a lower and milder pH of laundry detergents or cleaning products. In this context, mention may be made in particular of citric acid, succinic acid, glutaric acid, adipic acid, gluconic acid, and any desired mixtures thereof.
Similarly, further preferred builder substances that may be mentioned include polymeric amino dicarboxylic acids, their salts or their precursor substances.
Particular preference is given to polyaspartic acids and their salts and derivatives, which are disclosed in German Patent Application DE-A-195 40 086 to have not only cobuilder properties but also a bleach-stabilizing action.
Further suitable builder substances are polyacetals, which may be obtained by reacting dialdehydes with polyol carboxylic acids having 5 to 7 carbon atoms and at least 3 hydroxyl groups, as described, for example, in European Patent Application EP-A-0 280 223.
Preferred polyacetals are obtained from dialdehydes such as glyoxal, glutaraldehyde, terephthalaldehyde and mixtures thereof and from polyol carboxylic acids such as gluconic acid and/or glucoheptonic acid.
Further suitable organic builder substances are dextrins, examples being oligomers and polymers of carbohydrates, which may be obtained by partial hydrolysis of starches. The hydrolysis may be conducted by customary processes, for example, acid-catalyzed or enzyme-catalyzed processes. The hydrolysis products preferably have average molecular masses in the range from 400 to 500, 000 g/mol . Preference is given here to a polysaccharide having a dextrose equivalent (DE) in the range from 0.5 to 40, in particular from 2 to 30, DE being a common measure of the reducing effect of a polysaccharide in comparison to dextrose, which possesses a DE of 100. It is possible to use both maltodextrins having a DE of between 3 and 20 and dry glucose syrups having a DE of between 20 and 37, and also so-called yellow dextrins and white dextrins having higher molecular masses, in the range from 2000 to 30,000 g/mol. One preferred dextrin is described in British Patent Application 94 19 091.
The oxidized derivatives of such dextrins comprise their products of reaction with oxidizing agents which are able to oxidize at least one alcohol function of the saccharide ring to the carboxylic acid function.
Oxidized dextrins of this kind, and processes for preparing them, are known, for example, from European Patent Applications EP-A-0 232 202, EP-A-0 427 349, EP-A-0 472 042, and EP-A-0 542 496, and from International Patent Applications WO 92/18542, WO 93/08251, WO 93/16110, WO 94/28030, WO 95/07303, WO 95/12619, and WO 95/20608. Likewise suitable is an oxidized oligosaccharide in accordance with German Patent Application DE-A-196 00 018. A product oxidized at C6 of the saccharide ring may be particularly advantageous.
Oxydisuccinates and other derivatives of disuccinates, preferably ethylenediamine disuccinate, are further suitable cobuilders. Ethylenediamine N,N'-disuccinate (EDDS), whose synthesis is described, for example, in US 3,158,615, is used preferably in the form of its sodium or magnesium salts. Further preference in this context is given to glycerol disuccinates and glycerol trisuccinates as well, as described, for example, in U.S. Patents US 4,524,009 and US 4,639,325, in European Patent Application EP-A-0 150 930, and in Japanese Patent Application JP 93/339896. Suitable use amounts in formulations containing zeolite and/or silicate are from 3 to 15% by weight.
Examples of further useful organic cobuilders are acetylated hydroxy carboxylic acids and their salts, which may also be present in lactone form and which contain at least 4 carbon atoms, at least one hydroxyl group, and not more than two acid groups. Such cobuilders are described, for example, in International Patent Application WO 95/20029.
A further class of substance having cobuilder properties is represented by the phosphonates. The phosphonates in question are, in particular, hydroxyalkane- and aminoalkanephosphonates. Among the hydroxyalkanephosphonates, 1-hydroxyethane-1,1-diphos-phonate (HEDP) is of particular importance as a cobuilder. It is used preferably as the sodium salt, the disodium salt reacting neutrally and the tetrasodium salt giving an alkaline (pH 9) reaction.
Suitable aminoalkanephosphonates are preferably ethylenediaminetetramethylenephosphonate (EDTMP), diethylenetriaminepentamethylenephosphonate (DTPMP), and their higher homologs . They are used preferably in the form of neutrally reacting sodium salts, e.g., as the hexasodium salt of EDTMP or as the hepta- and octasodium salt of DTPMP. As a builder in this case, preference is given to using HEDP from the class of the phosphonates. Furthermore, the aminoalkanephosphonates possess a pronounced heavy metal binding capacity.
Accordingly, and especially if the compositions also contain bleach, it may be preferred to use aminoalkanephosphonates, especially DTPMP, or to use mixtures of said phosphonates.

Furthermore, all compounds capable of forming complexes with alkaline earth metal ions may be used as cobuilders.
Important further ingredients of the laundry detergents used in the process of the invention are surfactants, especially anionic surfactants. These include, in particular, sulfonates and sulfates, but also soaps.
Preferred surfactants of the sulfonate type are C9-13 alkylbenzenesulfonates, olefinsulfonates, i.e., mixtures of alkenesulfonates and hydroxyalkane-sulfonates, and also disulfonates, as are obtained, for example, from Clz-is monoolefins having a terminal or internal double bond by sulfonating with gaseous sulfur trioxide followed by alkaline or acidic hydrolysis of the sulfonation products.
Also suitable are alkanesulfonates, which are obtained from Clz-is alkanes, for example, by sulfochlorination or sulfoxidation with subsequent hydrolysis or neutralization, respectively.
Likewise suitable, in addition, are the esters of a-sulfo fatty acids (ester sulfonates), e.g., the a-sulfonated methyl esters of hydrogenated coconut, palm kernel or tallow fatty acids, which are prepared by a-sulfonation of the methyl esters of fatty acids of plant and/or animal origin having 8 to 20 carbon atoms in the fatty acid molecule, followed by neutralization to give water-soluble mono-salts. Preferably, these comprise the a-sulfonated esters of hydrogenated coconut, palm, palm kernel or tallow fatty acids, it being possible as well for sulfonation products of unsaturated fatty acids, e.g. oleic acid, to be present in small amounts, preferably in amounts of not more than about 2 to 3°s by weight. Particular preference is . CA 02315889 2000-08-14 given to a-sulfo fatty acid alkyl esters having an alkyl chain of not more than 4 carbon atoms in the ester group, examples being methyl esters, ethyl esters, propyl esters, and butyl esters. With particular advantage, the methyl esters of the a-sulfo fatty acids (MES) are used, and also their saponified di-salts.
Further suitable anionic surfactants are sulfated fatty acid glycerol esters which are the monoesters, diesters and triesters, and mixtures thereof, as obtained in the preparation by esterification of a monoglycerol with from 1 to 3 mol of fatty acid or in the transesterification of triglycerides with from 0.3 to 2 mol of glycerol.
Preferred alk(en)yl sulfates are the alkali metal salts, and especially the sodium salts, of the sulfuric monoesters of Clz-C1$ fatty alcohols, examples being those of coconut fatty alcohol, tallow fatty alcohol, lauryl, myristyl, cetyl or stearyl alcohol, or of Clo-Czo oxo alcohols, and those monoesters of secondary alcohols of these chain lengths. Preference is also given to alk(en)yl sulfates of said chain length which contain a synthetic straight-chain alkyl radical prepared on a petrochemical basis, these sulfates possessing degradation properties similar to those of the corresponding compounds based on fatty-chemical raw materials. From a detergents standpoint, Clz-Cis alkyl sulfates and Clz-Cis alkyl sulfates, and also C14-Cis alkyl sulfates, are particularly preferred. In addition, 2,3-alkyl sulfates, which may for example be prepared in accordance with US Patents 3,234,258 or 5,075,041 and obtained as commercial products from Shell Oil Company under the name DAN~, are suitable anionic surfactants.

Also suitable are the sulfuric monoesters of the straight-chain or branched C~_zl alcohols ethoxylated with from 1 to 6 mol of ethylene oxide, such as 2-methyl-branched C9_11 alcohols containing on average 3.5 mol of ethylene oxide (EO) or Clz-is fatty alcohols containing from 1 to 4 EO. Because of their high foaming they are used in laundry detergents only in relatively small amounts, for example, in amounts of from 1 to 5~S by weight .
Further preferred anionic surfactants include the salts of alkylsulfosuccinic acid, which are also referred to as sulfosuccinates or as sulfosuccinic esters and which constitute the monoesters and/or diesters of sulfosuccinic acid with alcohols, preferably fatty alcohols and especially ethoxylated fatty alcohols.
Preferred sulfosuccinates comprise Ca_1s fatty alcohol radicals or mixtures thereof. Especially preferred sulfosuccinates contain a fatty alcohol radical derived from ethoxylated fatty alcohols which themselves represent nonionic surfactants (for description, see below). Particular preference is given in turn to sulfosuccinates whose fatty alcohol radicals are derived from ethoxylated fatty alcohols having a narrowed homolog distribution. Similarly, it is also possible to use alk(en)ylsuccinic acid containing preferably 8 to 18 carbon atoms in the alk(en)yl chain, or salts thereof.
Further suitable anionic surfactants include fatty acid derivatives of amino acids, for example, of N-methyl-taurine (taurides) and/or of N-methylglycine (sarcosides). Particular preference is given here to sarcosides and to the sarcosinates and, of these, especially the sarcosinates of higher fatty acids, which may be mono- or polyunsaturated, such as oleyl sarcosinate.

Further suitable anionic surfactants are, in particular, soaps, preferably in amounts of from 0.2 to 5% by weight. Suitable soaps include in particular saturated fatty acid soaps, such as the salts of lauric acid, myristic acid, palmitic acid, stearic acid, hydrogenated erucic acid and behenic acid, and, in particular, mixtures of soaps derived from natural fatty acids, e.g., coconut, palm kernel, or tallow fatty acids. Together with these soaps, or as substitutes for soaps, it is also possible to use the known alkenylsuccinic salts.
The anionic surfactants, including the soaps, may be present in the form of their sodium, potassium or ammonium salts and also as soluble salts of organic bases, such as mono-, di- or triethanolamine.
Preferably, the anionic surfactants are in the form of their sodium or potassium salts, in particular in the form of the sodium salts.
The anionic surfactants are present in the compositions of the invention, and are used in the process of the invention, in amounts of preferably from 1 to 30% by weight, in particular in amounts from 5 to 25% by weight.
In addition to the anionic surfactants and the cationic, zwitterionic and amphoteric surfactants, particular preference is given to nonionic surfactants.
Nonionic surfactants used are preferably alkoxylated, advantageously ethoxylated, especially primary, alcohols having preferably 8 to 18 carbon atoms and on average from 1 to 12 mol of ethylene oxide (EO) per mole of alcohol, in which the alcohol radical may be linear or, preferably, methyl-branched in position 2 and/or may comprise linear and methyl-branched radicals in a mixture, as are commonly present in oxo alcohol radicals. In particular, however, preference is given to alcohol ethoxylates containing linear radicals from alcohols of natural origin having 12 to 18 carbon atoms, e.g., from coconut, palm, tallow fatty or oleyl alcohol and on average from 2 to 8 EO per mole of alcohol. Preferred ethoxylated alcohols include, for example, C12-14 alcohols containing 3 EO or 4 EO, C9_11 alcohols containing 7 EO, C13-is alcohols containing 3 EO, 5 EO, 7 EO or 8 EO, C12_la alcohols containing 3 EO, 5 EO or 7 EO, and mixtures thereof, such as mixtures of C12-14 alcohol containing 3 EO and Cla-18 alcohol containing 7 EO. The stated degrees of ethoxylation represent statistical mean values, which for a specific product may be an integer or a fraction. Preferred alcohol ethoxylates have a narrowed homolog distribution (narrow range ethoxylates, NREs). In addition to these nonionic surfactants it is also possible, as described above, to use fatty alcohols containing more than 12 EO. Examples thereof are (tallow) fatty alcohols containing 14 EO, 16 EO, 20 EO, 25 EO, 30 EO or 40 EO.
The nonionic surfactants also include alkyl glycosides of the general formula RO(G)X, where R is a primary straight-chain or methyl-branched aliphatic radical, especially an aliphatic radical methyl-branched in position 2, containing 8 to 22, preferably 12 to 18, carbon atoms, and G is the symbol representing a glycose unit having 5 or 6 carbon atoms, preferably glucose. The degree of oligomerization, x, which indicates the distribution of monoglycosides and oligoglycosides, is any desired number - which, as a variable to be determined analytically, may also be a fraction - between 1 and 10; preferably, x is from 1.2 to 1.4.

Further suitable surfactants are polyhydroxy fatty acid amides of the formula (I) Rz R1-CO-N- [Z] ( I ) , where R1C0 is an aliphatic aryl radical having 6 to 22 carbon atoms, R2 is hydrogen or an alkyl or hydroxyalkyl radical having 1 to 4 carbon atoms, and [Z] is a linear or branched polyhydroxyalkyl radical having 3 to 10 carbon atoms and from 3 to 10 hydroxyl groups. The polyhydroxy fatty acid amides are derived preferably from reducing sugars having 5 or 6 carbon atoms, especially glucose. The group of the polyhydroxy fatty acid amides also includes compounds of the formula (II) Ra-O-Rs R3-CO-N- [Z] (II) , where R3 is a linear or branched alkyl or alkenyl radical having 7 to 12 carbon atoms, R4 is a linear, branched or cyclic alkylene radical or an arylene radical having 2 to 8 carbon atoms and RS is a linear, branched or cyclic alkyl radical or an aryl radical or an oxyalkyl radical having 1 to 8 carbon atoms, preference being given to C1-C4 alkyl radicals or phenyl radicals, and [Z] is a linear polyhydroxyalkyl radical whose alkyl chain is substituted by at least two hydroxyl groups, or alkoxylated, preferably ethoxylated or propoxylated, derivatives of said radical. Here too, [Z] is preferably obtained by reductive amination of a sugar, e.g., glucose, fructose, maltose, lactose, galactose, mannose, or xylose. The N-alkoxy or N-aryloxy-substituted compounds may then be converted to the desired polyhydroxy fatty acid amides, for example, in accordance with the teaching of International Patent Application WO 95/07331 by reaction with fatty acid methyl esters in the presence of an alkoxide as catalyst.
A further class of nonionic surfactants used with preference, which are used either as sole nonionic surfactant or in combination with other nonionic surfactants, in particular together with alkoxylated fatty alcohols and/or alkyl glycosides, are alkoxylated, preferably ethoxylated, or ethoxylated and propoxylated, fatty acid alkyl esters, preferably having 1 to 4 carbon atoms in the alkyl chain, especially fatty acid methyl esters, as are described, for example, in Japanese Patent Application JP 58/217598, or those prepared preferably by the process described in International Patent Application WO-A-90/13533. Preferred nonionic surfactants are C12-Cla fatty acid methyl esters containing on average from 3 to 15 EO, in particular containing on average from 5 to 12 EO, whereas fatty acid methyl esters with higher degrees of ethoxylation are particularly advantageous - as described above - as binders.
Especially C12-C1$ fatty acid methyl esters containing from 10 to 12 EO may be used both as surfactants and as binders.
Nonionic surfactants of the amine oxide type, examples being N-cocoalkyl-N,N-dimethylamine oxide and N-tallow-alkyl-N,N-dihydroxyethylamine oxide, and of the fatty acid alkanolamide type, may 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 thereof.

Further suitable surfactants include those known as Gemini surfactants. This term is used generally to refer to those compounds which possess two hydrophilic groups and two hydrophobic groups per molecule. These groups are generally separate from one another as a result of what is known as a spacer. This spacer is generally a carbon chain, which should be long enough to give the hydrophilic groups a sufficient spacing to allow them to act independently of one another.
Surfactants of this kind are generally notable for an unusually low critical micelle concentration and the ability to reduce greatly the surface tension of water.
In exceptional cases, however, the expression Gemini surfactants is used to embrace not only dimeric but also trimeric surfactants.
Examples of suitable Gemini surfactants are sulfated hydroxy mixed ethers in accordance with German Patent Application DE-A-43 21 022 or dimer alcohol bis- and trimer alcohol tris-sulfates and ether sulfates in accordance with German Patent Application DE-A-195 03 061. Endgroup-capped dimeric and trimeric mixed ethers in accordance with German Patent Application DE-A-195 13 391 are notable in particular for their bi- and multifunctionality. Thus said endgroup-capped surfactants possess good wetting properties and are low in foam, so making them particularly suitable for use in machine washing or cleaning processes.
However, it is also possible to use gemini-polyhydroxy fatty acid amides or poly-polyhydroxy fatty acid amides, as described in International Patent Applications WO-A-95/19953, WO-A-95/19954, and WO-A-95/19955.
In addition to the surfactants, the compositions may also include components which promote the removal of oils and fats from textiles by washing. This effect is particularly marked if a textile which has already been washed a number of times before with a laundry detergent of the invention comprising said oil- and fat-dissolving component becomes soiled. Examples of preferred oil- and fat-dissolving components include nonionic cellulose ethers such as methylcellulose and methylhydroxypropylcellulose containing from 15 to 30~
by weight methoxy groups and from 1 to 15~ by weight hydroxypropoxy groups, based in each case on the nonionic cellulose ether, and also the prior art polymers of phthalic acid and/or terephthalic acid and/or derivatives thereof, especially polymers of ethylene terephthalates and/or polyethylene glycol terephthalates, or their anionically and/or non-ionically modified derivatives. Among these, particular preference is given to the sulfonated derivatives of phthalic acid polymers and of terephthalic acid polymers.
The other constituents of laundry detergents include graying inhibitors (antiredeposition agents), foam inhibitors, bleaches, bleach activators, optical brighteners, enzymes, fabric softeners, dyes, fragrances, and also neutral salts such as sulfates and chlorides in the form of their sodium salts or potassium salts.
To lower the pH of laundry detergents or cleaning products it is also possible to use acidic salts or slightly alkaline salts. As acidifying component, preference is given in this context to bisulfates and/or bicarbonates or to the abovementioned organic polycarboxylic acids which may also be used as builder substances at the same time. Particular preference is given to the use of citric acid.

Among the compounds which act as bleaches and which in water produce HZO2, particular importance is possessed by sodium perborate tetrahydrate, sodium perborate monohydrate, and sodium percarbonate. Further bleaches that may be used are, for example, peroxy pyro-phosphates, citrate perhydrates, and H20z-donating peracidic salts or peracids, such as perbenzoates, peroxophthalates, diperazelaic acids, phthaloiminoper-acid, or diperdodecanedioic acid.
Bleach activators which may be used are compounds which under perhydrolysis conditions give rise to aliphatic peroxo carboxylic acids having preferably 1 to 10 carbon atoms, in particular 2 to 4 carbon atoms, and/or substituted or unsubstituted perbenzoic acid. Suitable substances are those which carry O-acyl and/or N-acyl groups of the stated number of carbon atoms, and/or substituted or unsubstituted benzoyl groups. Preference is given to polyacylated alkylenediamines, especially tetraacetylethylenediamine (TAED), acylated triazine derivatives, especially 1,5-diacetyl-2,4-dioxohexa-hydro-1,3,5-triazine (DADHT), acylated glycolurils, especially tetraacetylglycoluril (TAGU), N-acyl imides, especially N-nonanoylsuccinimide (NOSI), acylated phenolsulfonates, especially n-nonanoyl- or isononanoyloxybenzenesulfonate (n- or iso-NOBS), carboxylic anhydrides, especially phthalic anhydride, acylated polyhydric alcohols, especially triacetin, ethylene glycol diacetate, 2,5-diacetoxy-2,5-dihydro-furan, and the enol esters known from German Patent Applications DE-A-196 16 693 and DE-A-196 16 767, and also acetylated sorbitol and mannitol and/or the mixtures thereof described in European Patent Application EP-A-0 525 239 (SORMAN), acylated sugar derivatives, especially pentaacetylglucose (PAG), pentaacetylfructose, tetraacetylxylose and octaacetyl-lactose, and acetylated, optionally N-alkylated glucamine and gluconolactone, and/or N-acylated lactams, for example, N-benzoylcaprolactam. Hydro-philically substituted acylacetals known from German Patent Application DE-A-196 16 769 and acyllactams described in German Patent Application DE-A-196 16 770 and in International Patent Application WO-A-95/14075 are likewise used with preference. Combinations of conventional bleach activators, known from German Patent Application DE-A-44 43 177, may also be used.
These bleach activators are in customary quantities, preferably in amounts of from 1 to 10~s by weight, and in particular from 2 to 8~ by weight, based on the overall composition.
In addition to the conventional bleach activators, or instead of them, it is also possible to incorporate what are known as bleaching catalysts into the tablets.
These substances are bleach-boosting transition metal salts or transition metal complexes such as, for example, Mn-, Fe-, Co-, Ru- or Mo-salen complexes or -carbonyl complexes. Other bleaching catalysts which can be used include Mn, Fe, Co, Ru, Mo, Ti, V and Cu complexes with N-containing tripod ligands, and also Co-, Fe-, Cu- and Ru-amine complexes.
For use in machine washing processes, it may be of advantage to add customary foam inhibitors to the compositions. Examples of suitable foam inhibitors are soaps of natural or synthetic origin having a high Cie-C24 fatty acid fraction. Examples of suitable nonsurfactant-type foam inhibitors are organo-polysiloxanes and their mixtures with microfine, optionally silanized silica and also paraffins, waxes, microcrystalline waxes, and mixtures thereof with silanized silica or bistearylethylenediamide. With advantages, use is also made of mixtures of different foam inhibitors, for example, mixtures comprising silicones, paraffins, or waxes. The foam inhibitors, especially those containing silicone and/or paraffin, are preferably bound on a granular, water-soluble or water-dispersible support substance. Particular preference is given in this context to mixtures of paraffins and bistearylethylenediamides.
Suitable enzymes include in particular those from the class of the hydrolases, such as the proteases, lipases or lipolytic enzymes, amylases, cellulases, and mixtures thereof. Oxireductases are also suitable.
Especially suitable enzymatic active substances are those obtained from bacterial strains or fungi, such as Bacillus subtilis, Bacillus licheniformis, Streptomyces griseus and Humicola insolens. Preference is given to the use of proteases of the subtilisin type, and especially to proteases obtained from Bacillus lentus.
Of particular interest in this context are enzyme mixtures, examples being those of protease and amylase or protease and lipase or lipolytic enzymes, or protease and cellulase, or of cellulase and lipase or lipolytic enzymes, or of protease, amylase and lipase or lipolytic enzymes, or protease, lipase or lipolytic enzymes and cellulase, but especially protease- and/or lipase-containing mixtures or mixtures with lipolytic enzymes. Examples of such lipolytic enzymes are the known cutinases. Peroxidases or oxidases have also proven suitable in certain cases. The suitable amylases include, in particular, a-amylases, iso-amylases, pullulanases, and pectinases. Cellulases used are preferably cellobiohydrolases, endoglucanases and ~-glucosidases, which are also called cellobiases, and mixtures of these. Since the various types of cellulase differ in their CMCase and Avicelase activities, the desired activities may be established by means of specific mixtures of the cellulases.

The enzymes may be adsorbed on carrier substances and/or embedded in coating substances in order to protect them against premature decomposition. The proportion of the enzymes, enzyme mixtures or enzyme granules may be, for example, from about 0.1 to 5% by weight, preferably from 0.1 to about 2% by weight.
In addition to phosphonates, the compositions may include further enzyme stabilizers. For example, from 0.5 to 1% by weight of sodium formate may be used. Also possible is the use of proteases, which are stabilized with soluble calcium salts and with a calcium content of preferably about 1.2% by weight, based on the enzyme. As well as calcium salts, magnesium salts also serve as stabilizers. Particularly advantageous, however, is the use of boron compounds, for example, of boric acid, boron oxide, borax and other alkali metal borates such as the salts of orthoboric acid (H3B03), of metaboric acid (HB02), and of pyroboric acid (tetraboric acid H2B40~) .
Graying inhibitors have the function of keeping the dirt detached from the fiber in suspension in the liquor and so preventing the redeposition of the dirt.
Suitable for this purpose are water-soluble colloids, usually organic in nature, examples being the water-soluble salts of polymeric carboxylic acids, glue, gelatin, salts of ethercarboxylic acids or ether-sulfonic acids of starch or of cellulose or salts of acidic sulfuric esters of cellulose or of starch.
Water-soluble polyamides containing acidic groups are also suitable for this purpose. Furthermore, soluble starch preparations, and starch products other than those mentioned above, may be used, examples being degraded starch, aldehyde starches, etc. Polyvinyl-pyrrolidone may also be used. Preference, however, is given to the use of cellulose ethers, such as carboxy-methylcellulose (Na salt), methylcellulose, hydroxy-alkylcellulose and mixed ethers, such as methylhydroxy-ethylcellulose, methylhydroxypropylcellulose, methyl-carboxymethylcellulose and mixtures thereof, and also polyvinylpyrrolidone, for example, in amounts of from 0.1 to 5°s by weight, based on the compositions.
As optical brighteners, the compositions may include derivatives of diaminostilbenedisulfonic acid and/or its alkali metal salts. Suitable, for example, are salts of 4,4'-bis(2-anilino-4-morpholino-1,3,5-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. It is also possible for brighteners of the substituted diphenylstyryl type to be present, for example, the alkali metal salts of 4,4'-bis(2-sulfostyryl)biphenyl, 4,4'-bis(4-chloro-3-sulfostyryl)biphenyl, or 4-(4-chlorostyryl)-4'-(2-sulfostyryl)biphenyl. Mixtures of the aforementioned brighteners may also be used.

Exams es Laundry detergents of the invention were prepared by first preparing a base laundry detergent in an extrusion process and then admixing the bleach granules and also enzyme granules and TAED granules to said base detergent.
The resultant detergents contained 16% by weight of a 3:1 mixture of sodium alkylbenzenesulfonate and fatty alcohol sulfate, 5% by weight of fatty alcohol ethoxylate, 0.7% by weight of soap, 25% by weight of zeolite NaA, 0.3% by weight of phosphonate, 3% by weight of citrate, 4% by weight of polymeric polycarboxylate, 3% by weight of sodium carbonate, 17%
by weight of sodium percarbonate, 7% by weight of TAED
and other auxiliaries. The detergents contained polymeric polycarboxylates in accordance with Table 1 and, to make them up to 100% by weight, water, salts and other laundry detergent ingredients (for example, defoamers, dyes, enzymes) used in small amounts.
The included Sokalan CP5 was incorporated basically by way of the premix. While the short-chain polyacrylate in E1 was admixed to the extruded base detergent after extrusion, the short-chain polyacrylate in E2 was likewise added to the premix prior to extrusion. The resultant coarse-particled detergents have average particle sizes of the order of 1.4 mm and bulk densities of between 750 and 800 g/1.

Table 1: Polymeric polycarboxylates in the laundry detergents prepared (type and ~ by weight based on the overall composition) Sokalan CP5 4.0 3.7 3.7 Sokalan PA30 - 0.3 -PA 2500 - - 0.3 Sokalan CP5~. Acrylic acid-malefic acid copolymer;
M = 70,000 g/mol; commercial product f rom BASF
Sokalan PA30~. Polyacrylic acid, sodium salt;
M = 4500 g/mol; commercial product from BASF
PA 2500: Polyacrylic acid, Na salt, M = 2500 g/m01; MW/Mn = 7 To investigate the heating rod deposits, a 10 1 stainless steel vessel with a heating rod suspended in it was used. The initial charge in each case comprised 1 of mains water of hardness 30°d (Ca:Mg=5:1).
Following the addition of 40 g of the respective formulation, the temperature was raised from room temperature to 90°C over the course of 60 minutes, in a time/temperature program, and this temperature was held for 30 minutes. Subsequently, the liquor was drained off and loose adhering deposits were rinsed off with mains water. After 10 such cycles, the deposits present on the heating rods were removed completely with citric acid solution and/or alkaline EDTA solution and were analyzed for CaO, MgO, Si02, and A1203 components by means of ICP (JY70 Plus; Instruments S.A.).

_ CA 02315889 2000-08-14 Table 2: Heating rod deposits [mg]
Test Ca0 [mg] Mg0 [mg] SiOz A1z03 Total [mg] [mg] [mg]

El 190 84 120 100 494 It was found that by using polymeric polycarboxylates having molecular masses below 10,000 g/mol in particulate extruded laundry detergents it was possible to achieve an overall reduction in the amount of deposit. In the case of E1, the amount of overall deposition was already markedly reduced in comparison to V1. The effect becomes extremely marked in the case of E2, where a polymeric polycarboxylate having a molecular mass of less than 4000 g/mol was used in the premix. In this case, the amount of deposition underwent overall reduction by a factor of more than 10.

Claims (35)

1. A laundry detergent or cleaning composition which substantially prevents deposits on heating rods, comprising a polycarboxylate having a molecular mass of less than 4000 g/mol as measured by means of GPC against a polyacrylate standard.

2. A coarse-particled laundry detergent or cleaning composition having an average particle size of between 0.2 and 4.0 mm, which substantially prevents deposits on heating rods, which comprises a polymeric polycarboxylate having a molecular mass of less than 10,000 g/mol as measured by means of GPC against a polyacrylate standard.

3. The composition as claimed in claim 2, comprising premix in which said polymeric polycarboxylate having a molecular mass of less than 10,000 g/mol is already present.

4. The composition as claimed in either of claims 2 and 3, wherein said polymeric polycarboxylate has a molecular mass of less than 8000 g/mol, as measured by means of GPC against a polyacrylate standard.

5. The composition as claimed in claim 4, wherein the molecular mass is in the range of from 3000 to 8000 g/mol.

6. The composition as claimed in claim 4, wherein the molecular mass is in the range of from 4000 to 5000 g/mol.

7. The composition as claimed in any of claims 1 to 6, wherein said polycarboxylate comprises a polyacrylate.

8. The composition as claimed in claim 7, wherein the polycarboxylate comprises a homopolymeric polyacrylate.

9. The composition as claimed in any of claims 1 to 3 and 7 and 8, wherein said polycarboxylate has a molecular mass of less than 3500 g/mol, as measured by means of GPC against a polyacrylate standard.

10. The composition as claimed in claim 9, wherein the molecular mass is in the range of between 3500 and 1500 g/mol.

11. The composition as claimed in claim 9, wherein the molecular mass is in the range of between 3000 and 2000 g/mol.

12. The composition as claimed in any of claims 1 to 11, wherein said polycarboxylate has a narrow molecular mass distribution.

13. The composition as claimed in any of claims 3 to 12, which comprises a composition having bulk densities of more than 600 g/l, and wherein said premix comprises a solid premix which comprises individual raw materials and/or compounded components which are present as solids at room temperature under a pressure of 1 bar and have a melting point or softening point of not below 45°C, and further comprises, if desired, up to 10%
by weight of nonionic surfactants which are liquid at temperatures below 45°C under a pressure of 1 bar, said premix being essentially free from water and comprising at least one raw material or compounded component which is in solid form under a pressure of 1 bar and at temperatures below 45°C
but under the premix processing conditions is in the form of a melt that acts as a polyfunctional, water-soluble binder that during the preparation of the compositions performs the function both of a lubricant and of an adhesive for the solid laundry detergents or cleaning products but has a disintegrating action when the composition is redissolved in an aqueous liquor.

14. The composition as claimed in claim 13, wherein the bulk densities are more than 700 g/l.

15. The composition as claimed in any of claims 2 to 14, which is a compacted form.

16. The composition as claimed in claim 15, which is an extrudate.

17. The composition as claimed in any of claims 1 to 16, comprising not only the polymeric poly-carboxylate having a molecular mass of less than 4000 g/mol as measured by means of GPC against a polyacrylate standard but also a further polymeric polycarboxylate, said further polymeric polycarboxylate comprising a copolymeric polycarboxylate and has a molecular mass, as measured by means of GPC against a polyacrylate standard, from the range from 20,000 to 70,000 g/mol, and the ratio of the polymeric polycarboxylate having a molecular mass of less than 4000 g/mol to the copolymeric polycarboxylate is in the range from 2:1 to 1:20.

18. The composition as claimed in claim 17, wherein the copolymeric polycarboxylate is a copolymer of (meth)acrylic acid with maleic acid.

19. The composition as claimed in claim 17 or 18, wherein the ratio is in the range from 1:1 to 1:15.

20. The composition as claimed in any of claims 1 to 16, wherein the composition contains no polymeric polycarboxylate other than the polymeric polycarboxylate having a molecular mass of less than 4000 g/mol as measured by means of GPC
against a polyacrylate standard.

21. A process for preventing deposits on heating rods during the machine washing of textiles, using water of any desired hardness and a water softener whose principal inorganic constituents comprise crystalline aluminosilicate and alkali metal carbonate, which comprises using as encrustation inhibitor a polymeric polycarboxylate having a molecular mass of less than 4000 g/mol as measured by means of GPC against a polyacrylate standard.

22. The process as claimed in claim 21, wherein a homopolymeric polycarboxylate is used, preferably having a molecular mass as measured by means of GPC against a polyacrylate standard, of below 3500 g/mol.

23. The process as claimed in claim 22, wherein the molecular mass is between 3500 and 1500 g/mol.

24. The process as claimed in claim 22, wherein the molecular mass is between 3000 and 200 g/mol.

25. The process as claimed in any of claims 21 to 24, wherein the polymeric polycarboxylate and the water softener are present in a laundry detergent, the polymer being used in amounts of from 0.1 to 15% by weight, and no other, separate water-softening agent being used.

26. The process as claimed in claim 25, wherein the amounts are from 0.5 to 10.

27. The process as claimed in claim 25, wherein the amounts are from 2 to 5% by weight.

28. The process as claimed in any of claims 21 to 24, wherein the polymeric polycarboxylate is present in a separately added water softener, which also comprises the inorganic softener constituents used in the process, and is dosed such that, based on the additionally used laundry detergent, the polycarboxylate is used in amounts of from 0.1 to 15% by weight.

29. The process as claimed in claim 28, wherein the amounts are from 0.5 to 10.

30. The process as claimed in claim 28, wherein the amounts are from 2 to 5% by weight

31. The process as claimed in any of claims 21 to 30, wherein water having a hardness of at least 14°d [German hardness] is used.

32. The use of homopolymeric polycarboxylates having a molecular mass of less than 4000 g/mol as measured by means of GPC against a polyacrylate standard for preventing deposits on heating rods during the machine washing of textiles.

33. A water softener composition comprising a) from 0.1 to 30% by weight of polymeric polycarboxylate having a molecular mass of less than 4000 g/mol as measured by means of GPC
against a polyacrylate standard, b) from 1 to 60% by weight of zeolite, and c) from 1 to 60% by weight of alkali metal carbonate, the sum of the constituents a), b) and c) making up at least 90% by weight of the overall softener.

34. The water softener composition as claimed in claim 33, wherein component a) is present in amounts of from 0.5 to 15% by weight, and component b) in amounts of from 10 to 50% by weight, and component c) in amounts of from 10 to 50% by weight, based in each case on the overall softener.

35. The water softener composition as claimed in claim 33, wherein component a) is present in amounts of from 2 to 10% by weight, and component b) in amounts from 15 to 45% by weight, and component c) in amounts from 15 to 45% by weight, based in each case on the overall softener.