EP0187257B1 - Carpet cleaning agent - Google Patents

Abstract

A carpet cleaning preparation in the form of a dry cleaning preparation in powder form which contains surfactants, organic solvents and zeolite and which is characterized in that the zeolite is in the form of a porous granulate which is unaffected by the mechanical stresses normally encountered during dry cleaning. The zeolite is preferably in the form of a porous granulate containing less than 2% by weight of particles 0.05 mm and smaller in size and less than 5% by weight of particles larger than 2 mm in size.

Description

The present invention relates to a powdery zeolite-containing agent intended for dry cleaning textiles, in particular carpets.

To clean carpets and other textile coverings on the spot, in addition to shampoos, powdered cleaning agents have recently been used which have the advantage of not leaving any edges and drying faster. Such cleaning powders contain, as essential components, surfactants and adsorbents as well as larger amounts of water in loosely bound form. The surfactants are believed to work together with the existing water to detach the dirt particles from the fibers and to transport them to the adsorbent, which is then brushed or vacuumed off with the dirt after the water has dried. A wide variety of materials have been proposed as adsorbents, for example synthetic resin foam powder (AT 296 477), fuller's earth, talc, sawdust (DE 15 19 045) and bleached wood flour (CH 461 685).

Despite the significantly smaller amounts of liquid that are applied with these powdery compositions compared to shampoos, drying times of up to several hours must also be observed with these compositions, since otherwise the residues can only be removed very incompletely. This has a disadvantageous effect especially in commercial cleaning.

A sodium aluminum silicate known as zeolite has proven to be a particularly effective adsorbent both in shampoo formulations and in powder detergents. Agents on this basis, as described, for example, in German Offenlegungsschrift 25 44 605, are distinguished by a high cleaning ability. Problems arise with this material, however, from the dust nuisance and an unusually strong adhesion of the fine-particle zeolite powder to the textile fibers, which means that the cleaning agent can only be removed incompletely and the treated textiles, in particular dark-colored carpets, have a gray appearance. The proposal in European patent application EP 62 536 to add zeolite powder to a likewise insoluble carrier material, in particular cellulose powder, has not been able to make any decisive changes to these undesirable side effects. It was therefore still the task to develop dry cleaning agents for textiles with better properties overall.

The present invention offers a solution to this problem in the form of dry cleaning agents in powder form, which contain surfactants, organic solvents and zeolite, and thereby are characterized in that the zeolite is in the form of a porous granulate which is resistant to the mechanical stresses which are usual in dry cleaning.

The agents according to the invention lack the abovementioned disadvantages of the agents of the prior art, that is to say they do not develop any annoying dust when used and can be removed almost completely from the textiles, so that graying does not occur. The re-soiling of the textiles after cleaning is unusually low. The agents are further characterized in that when they are used, normally no drying time is required between the incorporation of the powder into the textile and the removal of the powder. The finding of the solution according to the invention is particularly surprising that, despite the agglomeration of the zeolite powder to form larger, stable particles, the high cleaning performance of the agents working with finely divided zeolite is retained.

The preparation of the compositions comprises two stages, namely the production of the zeolite granules, which in the simplest case consist of zeolite and granulating aids, and the mixing of these granules with the other components of the compositions. However, some or all of these constituents can be wholly or partly incorporated into the granules in the first stage, so that only the constituents remaining, in particular the organic solvents, have to be mixed with the porous granules, the liquid constituents in particular being taken up by them .

The starting material for the production of the granules are the finely divided crystalline zeolites of types A, P, X, Y and hydroxysodalite, which are in dry form or in Form aqueous suspensions, such as those obtained in the manufacture, can be used. Sodium ions are said to be predominantly present as exchangeable cations in the zeolites. Zeolite A is preferably used, which has a particularly high cleaning power and is technically easily accessible. In air-dried commercial form, it has a water content of approximately 15 to 25 percent by weight, which cannot be further reduced without the use of extreme conditions. Unless otherwise stated, data on parts by weight of zeolite therefore include the water content of the zeolites which cannot be removed by air drying.

The content of zeolite in the finished cleaning agents is 40 to 90 percent by weight, preferably 55 to 75 percent by weight.

Zeolite granules are known from the literature in a wide variety of compositions, but are generally not suitable in this form for dry cleaning textiles. So you know from DOS 28 06 799 zeolite granules, which are produced by calcining at temperatures around 800 ° C and used to soften drinking water. Another type of zeolite granules is known for example from DAS 27 14 604, DOS 30 07 320, DOS 30 45 221 and EP-PS 21 267. The granules described there are primarily intended for use in detergents, i.e. their composition has been optimized with a view to rapid disintegration of the granules in the washing water, with the granulation consistently as a build-up granulation, that is to say through agglomeration of the finely divided zeolite with various additives was carried out.

The zeolite granules suitable for the agents according to the invention can also be obtained by built-up granulation, for example by agglomeration of zeolite powder with the aid of water and a granulating aid in a drum or paddle mixer or on a plate granulator. Other components of the cleaning agents, such as surfactants or acids, can be incorporated into the granules. If water is used in the granulation or if moist starting materials are used, the granulation process is followed by a drying step, for which also conventional processes, such as drying in a fluidized bed at temperatures up to about 200 ° C., can be used.

A particularly preferred process for the production of suitable porous zeolite granules is the spray drying process, in which an aqueous slurry of the zeolite, the granulating aid and, if appropriate, further constituents is sprayed into droplets which then dry in an air stream when they fall down. On the one hand, this process enables aqueous starting materials to be processed without problems and, on the other hand, combines the formation of the granulate particles and their drying in one process.

In any case, the purpose of the granulation is that significantly larger particles are built up from the originally very finely divided zeolite, which have such mechanical stability that they withstand the brushing and friction stress associated with the application. Suitable granules have less than 2% by weight of particles with a size of 0.05 mm and below and less than 5% by weight of particles larger than 2 mm (determined by sieve analysis). The best performance properties are shown by granules, the individual parts of which have a diameter of over 0.2 to 1.6 mm, more than 80 percent by weight, preferably over 90 percent by weight. The mechanical stability of the granules can be determined with the aid of a simple test: in a vibrating ball mill made of porcelain, which has a content of 1 liter and is loaded with 5 process balls of 28 mm in diameter, 100 g of the granules are run at 1400 revolutions per minute for 1 minute Treated for a minute, then sieved. In the case of granules suitable according to the invention, the proportion of particles with sizes up to 0.2 mm increases by no more than 15 percent by weight, preferably by no more than 5 percent by weight, in particular by no more than 2 percent by weight, based on the total weight of the granules.

Suitable granulation aids are solid, readily water-soluble organic or inorganic substances which have only a slight tendency to crystallize and are not hygroscopic. Substances which tend to polymerize, such as soluble alkali silicates, or which already have a polymeric structure, such as polymeric carboxylic acids and their salts, and soluble cellulose derivatives are particularly suitable. Water-soluble sodium silicate (water glass) and water- or alkali-soluble homo- and copolymers of acrylic acid or methacrylic acid are preferably used. Soluble sodium silicate in combination with polyacrylic acid or polymethacrylic acid is particularly preferred as the granulation aid. The amount of granulating aid, based on the total cleaning agent, is 1 to 20, preferably 5 to 20 percent by weight. Based on the Content of anhydrous zeolite, the amount of granulation aid is between 3 and 40 percent by weight, preferably between 10 and 30 percent by weight.

Suitable surfactants for the agents according to the invention are primarily nonionic and anionic surfactants. Nonionic surfactants are preferably used.

Suitable anionic surfactants are in particular those of the sulfate and sulfonate type, but other types such as soaps, long-chain N-acyl sarcosinates, salts of fatty acid cyanamides or salts of ether carboxylic acids, as are obtainable from long-chain alkyl or alkylphenyl polyglycol ethers and chloroacetic acid, can also be used . The anionic surfactants are usually used in the form of the sodium salts.

Particularly suitable surfactants of the sulfate type are the sulfuric acid monoesters of long-chain primary alcohols of natural and synthetic origin with 10 to 20 carbon atoms, i.e. of fatty alcohols, such as B. coconut fatty alcohols, tallow fatty alcohols, oleyl alcohol, or the C₁₀- C₂₀ - oxo alcohols and those of secondary alcohols of these chain lengths. In addition, the sulfuric acid monoesters of the aliphatic primary alcohols, secondary alcohols or alkylphenols ethoxylated with 1 to 6 mol of ethylene oxide come into consideration. Sulfated fatty acid alkanolamides and sulfated fatty acid monoglycerides are also suitable.

The surfactants of the sulfonate type are primarily the salts of sulfosuccinic acid mono- and diesters with 6 to 22 carbon atoms in the alcohol parts, the alkylbenzenesulfonates with C₉ - C₁₅ alkyl groups and Esters of α-sulfo fatty acids, e.g. B. the α-sulfonated methyl or ethyl esters of hydrogenated coconut, palm kernel or tallow fatty acids. Other useful surfactants of the sulfonate type are the alkanesulfonates which are obtainable from C₁₂-C₁₈ alkanes by sulfochlorination or sulfoxidation and subsequent hydrolysis or neutralization or by bisulfite addition to olefins, and also the olefin sulfonates, which are mixtures of alkene and hydroxyalkanesulfonates and disulfonates, such as they are obtained, for example, from long-chain monoolefins with a terminal or internal double bond by sulfonation with gaseous sulfur trioxide and subsequent alkaline or acidic hydrolysis of the sulfonation products.

Suitable nonionic surfactants for the agents according to the invention are in particular addition products of 1 to 30, preferably 4 to 15 moles of ethylene oxide with 1 mole of a compound having 10 to 20 carbon atoms from the group of alcohols, alkylphenols, carboxylic acids and carboxamides. The addition products of ethylene oxide with long-chain primary or secondary alcohols, such as, for example, fatty alcohols or oxo alcohols, and with mono- or dialkylphenols having 6 to 14 carbon atoms in the alkyl groups are particularly important.

Furthermore, the non-ionic surfactants which can be used are the water-soluble adducts of ethylene oxide with 20 to 250 ethylene glycol ether groups and 10 to 100 propylene glycol ether groups with polypropylene glycol, alkylenediamine-poly-propylene glycol and with alkylpolypropylene glycols having 1 to 10 carbon atoms in the alkyl chain, in which the polypropylene glycol chain acts as a hydrophobic radical . Also nonionic surfactants of the amine oxide, sulfoxide or alkyl glucoside type can be used, for example N-cocoalkyl-N, N-dimethylamine oxide or the condensation products of long-chain alcohols having 10 to 18 carbon atoms and glucose, and also their ethylene oxide adducts.

Particularly preferred nonionic surfactants are the reaction products of 4 to 15 moles of ethylene oxide (EO) and 1 mole of fatty alcohol with 12 to 18 carbon atoms. Typical representatives of these surfactants are tallow fatty alcohol + 5 EO, tallow fatty alcohol + 14 ED, oleyl / cetyl alcohol + 10 EO and coconut fatty alcohol + 4 EO.

The agents according to the invention contain 0.5 to 15 percent by weight, preferably 1 to 5 percent by weight. They are preferably wholly or partly in the first step of the manufacture, i.e. incorporated in the granulation of the zeolite.

The agents of the invention contain organic solvents as a further component. All solvents customary in the field of textile cleaning can be used, but solvents with boiling points above 80 ° C. from the group consisting of gasolines, alcohols, ethers and esters are preferably used. Examples of such solvents are gasoline (boiling range 140 to 200 ° C), isopropanol, isooctanol, triethylene glycol, butyl diglycol and butyl diglycol acetate. Because of their good fat-dissolving power, gasoline, isopropanol, dipropylene glycol momomethyl ether and mixtures thereof are particularly preferred. The proportion of solvent in the cleaning agent is 5 to 30, preferably 8 to 25 percent by weight. Water is contained in the agents only in such an amount as is retained by the zeolites during the production of the granules.

Synthetic zeolites often contain large amounts of free alkalis, which can be recognized by the high pH of an aqueous slurry. Since many textile materials and dyes are sensitive to alkalis, acids can be added to neutralize the alkali in the preparation of the agents in order to avoid damage. Solid water-soluble organic or inorganic acids, for example amidosulfonic acid and oxalic acid, are preferred. Acidic alkali phosphates, tartaric acid, citric acid and ethylenediaminetetraacetic acid are particularly preferred because their salts, which form during the neutralization, support the cleaning action of the agents. The amount of acid is determined by the alkali content of the zeolite and the desired degree of neutralization. In general, no more than 10% by weight of acid, based on the total composition, is used, preferably an amount which causes the zeolite granules to have a pH between 6.5 and 9 (measured on a 1% slurry in water). having.

Polymeric carboxylic acids such as polyacrylic acid and polymethacrylic acid are also suitable for neutralization. If such acids are already used as granulation aids, it is normally not necessary to add further acids.

In addition to the constituents mentioned, the cleaning agents according to the invention can also contain further active substances customary in the cleaning treatment of textiles. Examples of such active ingredients are antistatic components, optical brighteners, substances that reduce re-soiling and perfume. These components together can contain up to 10 percent by weight, preferably make up up to 5% by weight of the cleaning agents. They are preferably added to the zeolite granules with the solvent in the second step of the production process.

The cleaning of the textiles and carpets takes place in such a way that the agents of this invention are applied to the surfaces to be cleaned and then rubbed intensively into the textiles, for example with the aid of a sponge or a brush, the dirt on the textiles being with the Particles of the detergent connects. As a rule, training times of 0.5 to 2.5 minutes, preferably 0.5 to 1.5 minutes per square meter are chosen. The residues are then removed from the textiles together with the dirt mechanically, for example by brushing or vacuuming. For the surface cleaning of textiles, depending on the abundance of the textiles and depending on the degree of soiling, the agents according to the invention use 20 to 200 grams per square meter, but larger quantities can also be applied in places to remove individual stains. For cleaning carpets, application rates of 50 to 150 grams per square meter are common. Although all steps of the method can be carried out manually, the preferred embodiment, in particular for carpets, is to carry out the rubbing in and, if appropriate, further steps with the aid of machines, for example combined spreading and brushing machines. The cleaning process is therefore suitable for both the household sector and for commercial use.

1st to 4th cleaning agents

• 1. In a drum mixer designed for laboratory use, 1.12 kg of zeolite A (sodium form, water content 18.2%, determined by drying at 800 ° C.) in powder form (particle size below 40 μm) and 124 g of powdery polymethacrylic acid (Rohagit S der Company Röhm) submitted and sprayed with constant circulation with a solution of 38 g water glass (25% in H₂O, SiO₂: Na₂O = 4: 1) and 14 g of a nonionic surfactant made from tallow alcohol and 14 mol EO in 700 ml tap water. After the addition had ended, the mixture was mixed for a further 10 minutes, and the free-flowing granules formed were then discharged. In order to drive off excess adhering water, the granules were dried on a tray in a drying cabinet at 80 ° C. to constant weight. A one percent slurry of this granulate in water had a pH of 8.5. The sieve analysis of the granules showed that 95% of them were in the range between 0.3 and 1.2 mm. In the stability test, the fine fraction (up to 0.2 mm) rose from 1.2% to 4.1%.
  To produce the finished cleaning agent, 750 g of the dried granules were soaked with stirring with a solution of 20 g of a nonionic surfactant composed of tallow alcohol and 14 mol EO in 100 g isopropanol and 130 g butyl diglycol. The resulting detergent powder was easy to pour and free of dust.
• 2. In a Lödige mixer, 8.6 kg of zeolite A and 1 kg of powdered polymethacrylic acid of the same qualities as in Example 1, and 0.4 kg of polyvinylpyrrolidone (Kollidon Cl from BASF), which served as a cleaning enhancer, were introduced and kept under constant Circulation with a solution of 0.3 kg of water glass (25% in H₂O, SiO₂: Na₂O = 4: 1) and 0.15 kg of a nonionic surfactant from tallow alcohol and 14 moles of ethylene oxide sprayed in 5.7 kg of water. At the end of the addition, there was a water-containing granulate which was dried within 5 minutes by heating the mixer to 110 ° C. and further stirring. It showed 91% particle sizes between 0.5 and 1.5 mm in the sieve analysis. The proportion below 0.2 mm was 0.6% and rose to 3.8% in the stability test. In water the granules showed a pH of 8.9 (1%).
  The granules were further processed in an open mixing container in which they were converted into the end product by adding 25 percent by weight of isopropanol (based on the finished mixture) with slow stirring.
• 3. A mixture of 270 kg of a 45% aqueous suspension of zeolite Na-A (content based on anhydrous zeolite), 46 kg of water glass (37/40 Be, 34.5% aqueous solution), 18.8 kg of polymethacrylic acid, 4.0 kg of tallow alcohol with 5 moles of EO and 3.5 kg of tallow alcohol with 14 moles of EO were homogenized, heated to 65 ° C. and injected into the upper end of a spray tower. The drying was carried out in countercurrent with air at an inlet temperature between 150 ° C and 180 ° C. In this way, a granulate was obtained, which after sieve analysis 98.2% consisted of particles with sizes between 0.2 and 1.6 mm, 0.2% fine parts under 0.05 mm and 0.5% parts over 2 mm in diameter. In the stability test, the proportion of particles with sizes up to 0.2 mm rose from 9.6% to 10.8%.
  To produce the finished cleaning agent, 170 kg of the dry granules were mixed in a mixing container with 30 kg of gasoline (Isopar G). A white, dry-feeling, free-flowing product formed.
• 4. This cleaning agent was produced from the same zeolite granulate as the agent from Example 3. However, 20 kg of a mixture of 50 percent by weight of gasoline (Isopar G, boiling point 165 ° C.) and 50 percent by weight of n-propanol were added to each 80 kg of the granules.

5. to 6. cleaning agents according to the prior art

• 5. According to DOS 25 44 605, Example 21, a powdered carpet cleaner from zeolite powder, which was loaded with coconut fatty acid diethanolamide, was prepared by mixing with coconut alcohol sulfate and isopropanol. The product mainly consisted of very fine powder fractions less than 0.05 mm in diameter; in addition, loose agglomerates up to 5 mm in size were still present after stirring. In the stability test, the product disintegrated completely into particles less than 0.2 mm in diameter.
• 6. According to EP-OS 62 536, Example 1, a powdered carpet cleaning agent was made from cellulose fiber, zeolite powder, calcium carbonate, propylene glycol methyl ether and water. It was a flaky, slightly sticky product with no hard granules.
• 7. Cleaning effect, dust pollution and re-soiling
  The usage properties of the cleaning agents were examined on naturally soiled beige colored polyamide velor carpets. For this purpose, a long runner was divided into several segments, each of which was sprinkled evenly with one of the cleaning agents 1 to 6 in amounts of 70 g per square meter. Immediately after the detergents had been dispensed, they were worked into the carpet using a 40 kg single-pane cleaning machine with a rotating brush, which is customary in the commercial sector, for about 45 seconds per square meter. Only with the agent according to EP 62 536, as stated there, was an experiment carried out without brushing in. After the sufficient time for drying, the carpet segments were cleaned with detergents and adhering dirt for about 1 minute per square meter as far as possible. After the cleaning result had been assessed, the runner was released for use again and the re-soiling was assessed after 3 weeks.
  The evaluation of the performance properties was carried out by 5 examiners who had to give grades between 1 (excellent) and 6 (very poor). The mean values from the individual grades are summarized in Table 1.
• 8. Graying
  To determine this property, dark red polyamide velor carpets that were not soiled were treated with the cleaning agents as in Example 7. The graying was then determined visually by comparison with untreated pieces of carpet and evaluated using a point scale (1 = no graying, 5 = very strong graying). The results are shown in the last column of Table 1.

Claims (14)

1. A powder-form dry cleaning preparation for textiles, containing surfactants, organic solvents and zeolite, characterized in that the zeolite is present together with granulating aid in the form of porous granules which withstands the mechanical stressing normally encountered in dry cleaning.
2. A dry cleaning preparation as claimed in claim 1, characterized in that a zeolite of type A containing sodium ions as exchangeable cations is used.
3. A dry cleaning preparation as claimed in claim 1 or 2, characterized in that the zeolite granules are produced by spray-drying of an aqueous mixture of zeolite powder, granulating aid and, optionally, other constituents of the cleaning preparation.
4. A dry cleaning preparation as claimed in any of claims 1 to 3, characterized in that more than 80% by weight of the granules consist of particles larger than 0.2 to 1.6 mm in diameter.
5. A dry cleaning preparation as claimed in any of claims 1 to 4, characterized in that, before or during production of the granules, the zeolite is adjusted with an acid to a pH value of from 6.5 to 9 (as measured on a 1% suspension of the granules in water).
6. A dry cleaning preparation as claimed in any of claims 1 to 5, characterized in that it consists of
   40 to 90 % by weight zeolite,
   0.5 to 15 % by weight surfactant,
   5 to 30 % by weight organic solvent,
   1 to 20 % by weight granulating aid,
   0 to 10 % by weight solid, water-soluble acid and
   0 to 10 % by weight other usual constituents.
7. A dry cleaning preparation as claimed in any of claims 1 to 6, characterized in that the surfactant present is selected from the group of adducts of from 1 to 30 mol of ethylene oxide with long-chain primary or secondary alcohols containing from 10 to 20 carbon atoms or with alkylphenols containing from 6 to 14 carbon atoms in the alkyl groups and mixtures thereof.
8. A dry cleaning preparation as claimed in any of claims 1 to 7, characterized in that the organic solvent has a boiling point above 80°C and is selected from the group comprising gasolines, alcohols, ethers, esters and mixtures thereof.
9. A dry cleaning preparation as claimed in any of claims 1 to 8, characterized in that the granulating aid is selected from the group comprising water-soluble alkali silicates, water-soluble polymeric carboxylic acids and salts thereof, water-soluble cellulose derivatives and mixtures thereof.
10. A dry cleaning preparation as claimed in any of claims 1 to 9, characterized in that it is produced from zeolite granules by mixing with a solution of surfactant and, optionally, other constituents in an organic solvent and consists of

    55 to 75 % by weight   zeolite Na-A,

    1 to 5 % by weight   adduct of from 4 to 15 mol of EO with C₁₂₋₁₈ fatty alcohols,

    8 to 25 % by weight   organic solvent from the group comprising dipropylene glycol monomethyl ether, gasoline, isopropanol and mixtures thereof,

    5 to 20 % by weight   granulating aid in the form of a combination of water-soluble sodium silicate and polyacrylic acid or polymethacrylic acid and

    0 to 5 % by weight   other usual constituents.
11. A process for producing a powder-form dry cleaning preparation for textiles in which zeolite powder is converted by means of a granulating aid into porous granules which withstands the methanical stressing normally encountered in dry cleaning and the granules thus obtained are charged with organic solvent and, optionally, other constituents.
12. A process as claimed in claim 11, characterized in that the zeolite granules are produced by spray drying of an aqueous mixture of zeolite powder, granulating aid and, optionally, other constituents of the cleaning preparation.
13. A process for cleaning textiles, more especially carpets, in which a dry cleaning preparation of the type claimed in any of claims 1 to 10 is applied to the textile in quantities of from 20 to 200 grams per square metre and is intensively rubbed into the textile for 0.5 to 2.5 minutes per square metre, the soil and cleaning preparation combining with one another, after which the residues are mechanically removed from the textile.
14. A process for cleaning carpets as claimed in claim 13, characterized in that the rubbing-in of the cleaning preparation and, optionally, other steps of the process are carried out by means of appliances or machines, 50 to 150 grams per square metre of cleaning preparation are used and the rubbing-in time is 0.5 to 1.5 minutes per square metre.