EP0118663B1 - Washing and cleansing agent - Google Patents

Abstract

Powder-form washing and cleaning agents which can be made up into stock liquors containing in addition to synthetic surfactants and ingredients such as alkali carbonates, alkali silicates, alkali sulfates, water-soluble, organic or inorganic complexing agents, (a) from 10 to 40% by weight of finely particulate zeolites of the NaA or NaX type or mixtures thereof and (b) from 0.5 to 2.5% by weight of xanthan gum as dispersant in a ratio by weight of a:b of from 5:1 to 25:1 for the preparation of approximately 10% by weight aqueous stable stock liquor suspensions.

Description

In the commercial and hospital sector, so-called exclusive detergents have a high share of total detergent consumption. Except for bleaching agents, single-use detergents contain all the components necessary for an optimal washing process, namely surfactants, soda, silicates, triphosphates, as well as graying inhibitors, optical brighteners and other things. The bleaching agent missing from this list (perborate or chlorine bleach) is, in practice, fed separately into the washing process if necessary. Depending on the size of the company and the type of washing machine used, detergents alone are either flushed directly into the washing process as a powder via a metering device or are first prepared as so-called stock lyes and then fed to the washing process as a solution. The production of base liquor is common today in such large companies, where washing is carried out in car washes and automatic dosing is practically indispensable. Working with stock liquors considerably rationalizes the washing process, but also requires considerable investments, which not every company can spend due to cost and space reasons.

• 1. In einen 1 m³ Flüssigkeit fassenden Kessel werden etwa 200 Liter enthärtetes Wasser eingeleitet.
• 2. Rührer und Heizung werden eingestellt; der Heizungsthermostat wird auf etwa 40 °C eingestellt.
• 3. Unter weiterem Wasserzulauf und Rühren werden zügig 100 kg Alleinwaschmittel (z. B. 4 Säcke ä 25 kg) in den Kessel geschüttet.
• 4. Der Wasserzulauf wird gestoppt, sobald die 1000 Liter-Markierung erreicht ist.
• 5. Es wird noch etwa 20 Minuten lang gerührt, wobei die Temperatur der Lösung auf bis zu 60 °C gesteigert werden kann. Dann ist die Stammlauge gebrauchsfertig und kann mit Hilfe einer Dosierpumpe in den Waschprozeß eingespeist werden.

Master liquors are understood to mean aqueous solutions of the detergent powder in a concentration of usually 5-15% by weight, usually about 10% by weight. They are made up in stock liquor containers, which are usually dimensioned so that they can hold one or two daily requirements for stock liquor. Capacity of 0.5 - 2 m ^{3 is} usual. An exemplary master liquor system includes a stirrer, indirect heating with steam and a pump that conveys the finished stock liquor to the washing machine. A 10% stock liquor is generally prepared as follows:

• 1. About 200 liters of softened water are introduced into a 1 m ³ liquid tank.
• 2. Stirrer and heating are set; the heating thermostat is set to around 40 ° C.
• 3. 100 kg of single-purpose detergent (eg 4 bags of 25 kg) are quickly poured into the kettle with further water supply and stirring.
• 4. The water supply is stopped as soon as the 1000 liter mark is reached.
• 5. The mixture is stirred for a further 20 minutes, during which the temperature of the solution can be increased up to 60 ° C. The base liquor is then ready for use and can be fed into the washing process with the aid of a metering pump.

The respective demand for the base liquor is carried out via the automatically controlled washing program. The flawless functioning of such a base liquor system may include a. ahead that the detergent ingredients are either completely dissolved in the alkali or at least finely divided in the floating state. Both the stopping and the creaming of water-insoluble constituents pose a danger to the automatic dosing, because a clogging of the line system of the plant caused thereby can cause considerable disturbances in the entire washing process.

In general, detergents that contain small amounts of water-insoluble, very fine-particle magnesium silicate are also designated as base liquors. Obviously, such small quantities do not cause any problems, as there have been exceptions so far and the powder detergents used could be used without any problems.

As is well known, the phosphate content of detergents is generally made increasingly responsible for water reutrophication by experts and the public and is therefore regarded as a disadvantage. A number of substances have therefore been proposed as a replacement for the detergent phosphates which have been customary to date. Sodium aluminum silicates in the form of the synthetically produced zeolites of the NaA and NaX type, as described, for example, in US Pat. Nos. 2,882,243 and 2,882,244, have apparently proven to be the best and have become established.

• 1. Ständiges Rühren der Stammlauge,
• 2 spezielle Pumpen (z. B. Hubkolbpumpen) zur Förderung der Stammlauge,
• 3. spezielle Konstruktion des Leitungssystems zwischen Stammlaugenbehälter und Waschmaschine, so daß ein Absetzen der unlöslichen Gerüstsubstanzpartikeln verhindert wird.

Powder detergents with such phosphate substitutes were first known in 1974 and described in German Offenlegungsschrift 24 12 837. Because of the increasing importance of zeolites, the task arose of introducing them into detergents with a base solution. However, due to their tendency to sedimentation, their use in stand-alone detergents only seems possible according to the current state of the art if the following conditions are met:

• 1. Constant stirring of the stock liquor,
• 2 special pumps (e.g. reciprocating pumps) to convey the base liquor,
• 3. special construction of the line system between the base liquor container and the washing machine, so that the insoluble scaffold particles are prevented from settling.

These prerequisites are, however, only available in very few companies, so that the development of a single detergent containing more sodium aluminum silicate for use in parent liquors has not yet been tackled.

DE-OS 30 06 333 detergent slurries are known, which can also contain up to 30 wt .-% sodium aluminum silicate. As a thickener, these stabilized suspensions contain a combination of a water-dispersible, crosslinked copolymer made from an acrylic acid and a polyester of a polyol on the one hand and sodium polyacrylate on the other. These detergent slurries are obtained by carefully stirring the individual components into the water provided in a specific order. These products are relatively low-water, viscous suspensions; However, their complicated manufacture makes them uninteresting for use in large laundries because the specialist is used to making the master liquor from one Make powder detergent by stirring in water and not by diluting a suspension.

Storage-stable and pumpable aqueous suspensions of sodium aluminum silicates, which are stabilized by the addition of a dispersant, are described in numerous publications, for example in German Offenlegungsschrift 25 27 388. These stable suspensions are as highly concentrated as possible in sodium aluminum silicate; They are used for the industrial production of detergent powders containing sodium aluminum silicate and are preferred to the dried sodium aluminum silicate powder.

The person skilled in the art could not derive any useful suggestions for solving the problem specified here from this prior art: a base liquor is the dilute aqueous solution or suspension of a detergent, so that the known teachings on the preparation of concentrated suspensions do not readily apply the preparation of dilute suspensions are applicable. In fact, none of the stabilizers described for concentrated sodium aluminum silicate suspensions has been suitable for the stabilization of a stock solution containing sodium aluminum silicate.

It was therefore completely surprising that xanthan gum proved to be a dispersing agent which was added as an additive in quantities of 0.5 to 2.5% by weight to powdered heavy-duty detergents containing 10 to 40% by weight of water-insoluble alkali aluminum silicate Exclusive detergents, which can be traded and sold as such and which, like the previously known tripolyphosphate-based agents, can be used without problems in master liquor systems and can be converted to about 10% alkalis.

The present invention therefore relates to pulverulent, base-leachable, alkaline-reacting detergents and cleaners containing synthetic surfactants, alkali aluminum silicates and preferably further constituents from the group of alkali carbonates, alkali silicates, alkali sulfates, water-soluble organic or inorganic complexing agents, optical brighteners and smaller amounts of other customary ones Additives which are characterized in that they contain a) 10 to 40, preferably 15 to 25% by weight finely divided zeolites of the NaA or NaX type or mixtures thereof, and b) 0.5 to 2.5, preferably 1.0 to Contain 2.0% by weight of xanthan gum, the weight ratio of a: b being 5: 1 to 25: 1, preferably 10: 1 to 20: 1, and which can be obtained by mixing with water to about 10% by weight. - Have% stable suspensions converted.

• 2 bis 40, insbesondere 5 - 15 Gew.-% einer Tensidkomponente aus anionischen und/oder nichtionischen Tensiden,
• 10 - 40, insbesondere 15 - 25 Gew.-% Zeolithe vom Typ NaA oder NaX bzw. deren Gemische,
• 0,5 - 2,5, insbesondere 0,5 - 2,0 Gew.-% Xanthangummi, wobei das Gew.-Verhältnis von Aluminiumsilikat zu Xanthangummi 5: bis 25: 1, vorzugsweise 10:1 bis 20:1 beträgt,
• 0 - 60, insbesondere 0,5 - 50 Gew.-% wasserlösliche organische oder anorganische Komplexierungsmittel, Alkalicarbonate, Alkalisilikate, Alkalisulfate sowie sonstige übliche Bestandteile pulverförmiger Wasch- und Reinigungsmittel, Rest bis 100 Gew.-%, höchstens jedoch 20 Gew.-%, freies Wasser.

The composition of the powdered preparations according to the invention is preferably in the range of the following recipe:

• 2 to 40, in particular 5-15% by weight of a surfactant component composed of anionic and / or nonionic surfactants,
• 10 to 40, in particular 15 to 25% by weight of zeolites of the NaA or NaX type or mixtures thereof,
• 0.5-2.5, in particular 0.5-2.0% by weight of xanthan gum, the weight ratio of aluminum silicate to xanthan gum being 5: to 25: 1, preferably 10: 1 to 20: 1,
• 0 - 60, in particular 0.5 - 50% by weight water-soluble organic or inorganic complexing agents, alkali carbonates, alkali silicates, alkali sulfates and other common constituents of powdered detergents and cleaning agents, the rest up to 100% by weight, but at most 20% by weight , free water.

The invention further relates to the use of b) 0.5 to 2.5% by weight of xanthan gum, based on the total weight of the dry washing and cleaning powder containing a) 10 to 40% by weight of NaA or zeolites NaX or mixtures thereof, also based on the dry powder, as a dispersant additive for the preparation of 10% by weight aqueous stable stock liquor suspensions, the ratio of a: b being 5: 1 to 25: 1.

"Xanthan gum" here is based on Römpps Chemie-Lexikon, 7th edition (1973), pages 1355 and 1356, a product that is known under the Anglo-Saxon name "Xanthan gum". Xanthan gum is a high molecular weight polysaccharide, i.e. H. an exocellular heteropolysaccharide derived from various types of Xanthomonas, e.g. B. Xanthomonas campestris is produced. They are hydrophilic colloids. Numerous publications deal with their production by aerobic propagation and cultivation of bacteria of the genus Xanthomonas in aqueous nutrient media. The basic work is described in US Pat. No. 3,000,790. Modifications of the fermentation process are described, for example, in US-PSS 3,020,206, 3,391,060, 3,427,226, 3,433,708, 3,271,267, 3,251,749, 3,281,329, 3,455,786, 3,565,763, 3,594,280, 3,391,061 and 4,119,546 and in DE-OSS 29 47 740 and 31 05 556.

The hydrophilic colloids produced by Xanthomonas campestris are polysaccharides that contain mannose, glucose, glucuronic acid, 0-acetyl residues and acetyl-linked pyruvic acid. They arise as an exocellular reaction product of the bacteria types mentioned when they are aerobically grown in aqueous nutrient solutions which, in addition to the usual growth-promoting components, in particular contain water-soluble carbohydrate compounds as a carbon source. In practice, glucose in particular is used as the source of assimilable carbon.

Such products are commercially available and are for example from Kelco Comp. Oklahoma / USA sold under the name KELZAN ^* . The following formula is given for this:

Examples of synthetic surfactants are anionic surfactants of the sulfonate type, such as alkylbenzenesulfonates (C _8-15 -alkyl), olefin sulfonates, ie mixtures of alkene and hydroxyalkanesulfonates and disulfonates, such as those obtained from C ₁₂ -C ₁₈ monoolefins with a terminal or internal double bond obtained by sulfonation with gaseous sulfur trioxide and subsequent alkaline or acidic hydrolysis of the sulfonation products. Also suitable are the alkanesulfonates which are obtainable from C ₁₂ -C ₁₈ -alkanes by sulfochlorination or sulfoxidation and subsequent hydrolysis or neutralization or by bisulfite addition to olefins, and the esters of α-sulfofatty acids, e.g. B. the a-sulfonic acids from methyl or ethyl esters of hydrogenated coconut, palm kernel or tallow fatty acids.

Suitable anionic surfactants of the sulfate type are the sulfuric acid monoesters of primary aliphatic C ₁₀ -C ₂₀ -alcohols (e.g. from coconut fatty alcohols, tallow fatty alcohols or oleyl alcohol) and those of secondary aliphatic C ₁₀ -C ₂₀ alcohols. Also suitable are sulfated fatty acid alkanolamides, fatty acid monoglycerides with C ₁₀ C2o fatty acids and the sulfates of the primary or secondary aliphatic C ₁₀ -C ₂₀ alcohols reacted with 1-6 mol ethylene oxide.

These surfactants with anionic groups can be in the form of their sodium, potassium and ammonium salt and as soluble salts of organic bases, such as mono-, di- or triethanolamine.

Suitable surfactants are also nonionic surfactants, primarily the adducts of 7-20 moles of ethylene oxide which are practically water-soluble at room temperature, with 1 mole of an aliphatic C ₁₀ -C ₂₀ alcohol, or an alkylphenol, fatty amine or a fatty acid. The ethoxylation products of the aliphatic alcohols, in particular the coconut or tallow fatty alcohols, the oleyl alcohol, the C ₁₀ -C ₂₀ oxo alcohols and the secondary aliphatic alcohols with essentially 12-18 C atoms are particularly important. In addition to these water-soluble nonionic surfactants, the corresponding not or not completely water-soluble ethoxylation products with 2-6 ethylene glycol ether residues in the molecule are also of interest when they are used together with the water-soluble ethoxylation products. Suitable nonionic surfactants are also the fatty acid alkanolamides, such as. B. the compounds coconut or tallow fatty acid ethanolamide and diethanolamide, oleic acid diethanolamide etc.

The useful nonionic surfactants also include the surface-active amine oxides, which are usually derived from tertiary amines with a hydrophobic C ₁₀ -C ₂₀ alkyl group and two shorter alkyl and / or alkylol groups each containing up to 4 C atoms. Typical representatives are, for example, the compounds N-dodecyl-N, N-dimethylamine oxide, N-tetradecyl-N, N-dihydroxyethylamine oxide or N-hexadecyl-N, N-bis (2,3-dihydroxypropyl) amine oxide.

The water-soluble organic or inorganic complexing agents for calcium can be found at the polycarboxylic acids, hydroxycarboxylic acids, aminocarboxylic acids, carhoxyalkyl ethers, polyanionic polymeric carboxylic acids, phosphonic acids and the polyphosphoric acids, these compounds mostly being used in the form of their water-soluble salts. Specific examples are citric acid, carboxymethyltartronic acid, mellitic acid, polyacrylic acid, poly-a-hydroxyacrylic acid, carboxymethyl malic acid, nitrilotriacetic acid, 1-hydroxy-ethane-1,1-di-phosphonic acid and the alkali metal pyrophoaphates, tripolyphosphates as well as the alkali metal salts and higher polyphosphorus phosphorus.

In addition to complexing agents, other common constituents of such agents are primarily alkalis such as alkali metal silicates, in particular alkali metal silicates and inorganic fillers such as sodium carbonate or sodium sulfate; small amounts may also be present, for example, of dirt carriers which suspend the dirt detached from the fibers in the liquor and so on prevent graying. For this purpose, water-soluble colloids of mostly organic nature are suitable, such as, 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 such as carboxymethyl cellulose or methyl cellulose, in particular their mixtures or salts of acidic sulfuric acid esters of cellulose or starch. Also wass _b rlösliche, polyamides containing acid groups are suitable for this purpose. Soluble starch preparations and starch products other than those mentioned above can also be used, e.g. B. degraded starch, aldehyde starches, etc. Polyvinylpyrrolidone is also useful.

Corrosion inhibitors, foam regulators, fragrances and dyes also belong to the other usual constituents of the agents according to the invention.

The following examples explain the subject matter of the invention without restricting it.

Examples

The constituents of the powder detergents were mixed in a Lödige mixer. Xanthan gum and fragrances were mixed in recently. However, the water- and temperature-stable components can also be processed into a so-called slurry and sprayed as a mixture. The powder obtained is then also mixed with xanthan gum and fragrances. In addition to the xanthan gum-free starting formulation, the following tables show 15 examples of detergents according to the present invention, which led to powder detergents which can be used as base lye.

For the experiments, in practice relevant 50 g of these detergents were stirred into 500 ml of softened water and first heated to 40 ° C, then to 60 ° C, although stepwise heating is not necessary for these experimental approaches. The stirring was continued at 60 ° C. for 30 minutes, the stirrer speed being 500 revolutions per minute. After 1 hour, during which cooling also took place, the stock liquor was subjectively assessed optically in terms of creaming and sediment. A second assessment was made in the same way after 24 hours.

In the tables, "EO" means ethylene oxide and e.g. B. "8 EO" the adduct of 8 moles of ethylene oxide to the immediately preceding compound. The product Kelzan ^® from Kelco Comp. used.

• Zusammensetzung; 1,04 Na2C- 1 A1₂C₃ - 2,05 Si0₂, Wassergehalt 21,2 %,
• Struktur: NaA, hochkristallin, kubisch mit abgerundeten Ecken und Kanten;
• Teilchengröße (Coulter Counter, Volumenverteilung); mittlerer Teilchengröße 4,8 µm; 100 % der Teilchen kleiner als 15 um;
• Calciumbindevermögen bei 22°C: 170 mg CaO/g.

The product SASIL ⁰ from Henkel KGaA, ie a NaA type zeolite, with the following characteristics was used as sodium aluminum silicate:

• Composition; 1.04 Na2C- 1 A1 ₂ C ₃ - 2.05 Si0 ₂ , water content 21.2%,
• Structure: NaA, highly crystalline, cubic with rounded corners and edges;
• Particle size (Coulter Counter, volume distribution); average particle size 4.8 µm; 100% of the particles smaller than 15 µm;
• Calcium binding capacity at 22 ° C: 170 mg CaO / g.

A finely divided zeolite NaA produced by industrial processes can contain minor amounts of zeolite NaX or zeolite HS which do not impair the builder properties. Such zeolite mixtures can be used according to the invention with the same success. Zeolite NaX instead of NaA is also suitable. Due to the manufacturing process, the crystalline zeolites can also contain the X-ray amorphous preforms of similar composition in insignificant amounts.

Comparative examples to Example 5 with (a) sodium polyacrylate (pigment distributor N from BASF) and (b) purified sodium carboxymethyl cellulose (Relatin 7000 P from Henkel KGaA):

Claims (5)

1. Powder-form, alkaline-reacting detergents and cleaning preparations capable of being made into stock liquors, containing synthetic surfactants, alkali aluminium silicates and, preferably, other constituents from the group comprising alkali carbonates, alkali silicates, alkali sulfates, water-soluble, organic or inorganic complexing agents, optical brighteners and relatively small quantities of other standard additives, characterized in that they contain a) from 10 to 40% by weight finely divided zeolites of the NaA or NaX type or mixtures thereof and b) from 0.5 to 2.5% by weight xanthan gum, the ratio by weight of a) to b) being from 5:1 to 25:1, and may be converted by mixing with water into approximately 10% by weight stable suspensions.

2. Detergents and cleaning preparations as claimed in Claim 1, characterized in that they contain a) from 15 to 25% by weight zeolites.

3. Detergents and cleaning preparations as claimed in Claim 1, characterized in that they contain b) from 1.0 to 2.0% by weight xanthan gum.

4. Detergents and cleaning preparations as claimed in Claims 1 and 2, characterized in that the ratio by weight of a) to b) is from 10:1 to 20:1.

5. The use of b) from 0.5 to 2.5% by weight xanthan gum, based on the total weight of the dry powder-form detergent and cleaning preparation containing a) from 10 to 40% by weight zeolites of the NaA or NaX type or mixtures thereof, again based on the dry powder, as a dispersion additive for the preparation of 10% by weight aqueous, stable stock liquor suspensions, the ratio of a) to b) being from 5:1 to 25:1.