EP0090291A2 - Two-step process for the washing and post treatment of textiles - Google Patents

Abstract

In the first step, the textiles are washed in a liquor which contains not more than 0.3 g of phosphorus per litre as phosphate. The washing liquor is obtained by dissolving a low-phosphate or phosphate- free detergent in water. In the second step, the textiles are treated with an acid-formulated liquid agent. This dissolves any incrustations formed in the first step and applies a softening finish to the textiles.

Description

The invention relates to a two-stage process for washing and post-treatment of textiles, in which textiles are freed from dirt in a first stage and in a second stage from incrustations and softened by textile softeners.

Highly effective heavy-duty detergents contain so-called builder substances, which, among other things, ensure that calcium and magnesium ions present in the wash water, which tend to form insoluble insoluble water, do not deposit on washing machine components and textiles. For use in detergents, sodium tripolyphosphate and certain sodium aluminosilicate, which are used to a considerable extent, have proven particularly useful as builders.

If detergents contain too little builder substances, the calcium and magnesium ions in the form of insoluble compounds can deposit on textiles and in the washing machine and collect there. On the one hand, these deposits can lead to faults in the washing process, for example to poor heat transfer as a result of deposits on the heating elements. On the other hand, the insoluble calcium and magnesium compounds can also deposit on the tissues and form so-called incrustations, which noticeably worsens the utility value of the textiles. Because of the well-known contribution of detergent phosphates for the eutrophication of waters, however, it is increasingly necessary to limit the use of detergent phosphates, which can effectively prevent deposits, which increases the risk of tissue incrustation if instead of the effective detergent phosphates, insufficient or unsuitable phosphate substitutes are used starts.

A number of measures have already become known for eliminating these disadvantages. DE-AS 24 37 173 describes a two-stage washing process which dissolves the acid-soluble incrustations which result from the main wash cycle of the previous wash in an acidic pre-wash liquor. This method has the disadvantage that incrustations that arise during subsequent washing can deposit on the textiles and are no longer removed before they are worn. So incrustations are consciously accepted, so that incrusted textiles have to be worn, because these incrustations are only removed during the subsequent washing.

DE-OS 28 27 571 describes a detergent in which there is an acidic component which is readily soluble at low wash liquor temperatures and, separately therefrom, an alkaline component which is soluble only at higher temperatures. The delayed resolution is e.g. B. achieved in that the alkaline component is encased by a only soluble in warm water or opening bag. This will cause the incrustations are dissolved in the initially acidic wash liquor and only with the gradual dissolution of the wash alkalis does the higher pH value of the wash liquor become necessary for an optimal washing effect.

The subject of DE-OS 29 16 416 is a detergent, wherein the alkaline detergent component having a water-soluble film of a nonionic surfactant Plated _- is gen and thereby the pH of the wash liquor only gradually increases in proportion as the alkaline components of the detergent dissolve.

A disadvantage of the two last-mentioned procedures, in addition to the time-consuming production of suitable agents, is that the incrustations dissolved during the acidic phase of the washing process remain in the washing liquor and — if the pH value rises, can be partially or even completely deposited again on the textiles.

After washing, textiles are often subjected to a post-treatment treatment with fabric softening agents and antistatic agents. This requires another step.

It is therefore an object of the present invention to provide a method which is suitable for washing and excrusting textiles and which comprises a process step which cleans the textiles and a process which dissolves incrustations includes driving stage, which avoids the disadvantages of the methods of the prior art.

This object is achieved according to the invention by a process which is characterized in that in a first process step the textiles are dispensed in one liter. washing liquor containing at most as much phosphate as 0.3 g, in particular 0.1 g phosphorus, formed from a low-phosphate or phosphate-free detergent dissolved in water, which allows incrustations to form, and washes the laundry in a second process step using an acidic, Post-treated incrustation-dissolving liquid agents containing textile softening agents.

Low-phosphate or phosphate-free detergents, which allow the formation of incrustations on the washed laundry, are to be understood within the scope of this disclosure as those which are used to prevent incrustations, i. H. do not contain sufficient amount of builder substances to remove the hardening agents from the wash liquor. Low-phosphate detergents contain, for example, less than about 30% by weight, in particular less than about 20% by weight, sodium tripolyphosphate and no or too little or insufficiently effective phosphate-free builder substances. Such detergents therefore form incrustations from the calcium and magnesium ions present in the wash water and carried into the wash liquor with the soiled textiles. In the second process step of the process according to the invention, these are dissolved in the treatment liquor by the specific acidic constituents of the aftertreatment agent. The aftertreatment liquor also softens the textiles by transferring the fabric softener from the aftertreatment liquor to the textiles.

The procedure according to the invention has the advantage that incrustations formed on the textiles by washing with low-phosphate or phosphate-free detergents are dissolved in the acidic aftertreatment liquor and are removed therefrom from the washed textiles. The process according to the invention has the further advantage that the textiles are both freed from incrustations and softened in one process step; during the excrusting aftertreatment, the fabric softening agents absorb the washed textiles and give them a pleasant full and soft feel. Since the known textile softeners are often good textile antistatic agents at the same time, the textiles are also given an antistatic treatment by the aftertreatment. If the acidic aftertreatment agents to be used according to the invention contain fragrances, this fragrance is transferred to the laundry items during the aftertreatment.

Detergents suitable for carrying out the process according to the invention are known mixtures of, for example, anionic, nonionic, amphoteric or zwitterionic surfactants, builders, dirt carriers, foam regulators, bleaching agents, enzymes, optical brighteners and fragrances. The textiles in these compositions are preferably washed at temperatures of 40-100 ° C., in particular at 60-95 ° C. The washing liquor in which the textiles are washed contains about 5 to 50 g of detergent per liter, the concentration being chosen so that the washing liquor per liter contains at most 0.3, in particular at most 0.1 g, phosphorus as phosphate.

The anionic surfactants include, in particular, alkali metal salts of synthetic organic sulfates or sulfonates with at least one hydrophobic organic radical. The detergents can also contain soaps made from natural or synthetically produced fatty acids. Of the nonionic surfactants, the ethoxylation products of fatty or oxo alcohols and alkylphenols are particularly important compounds. The amphoteric or zwitterioni-. see surfactants in the molecule contain both acidic groups such. B. the carboxyl, sulfo, sulfuric acid half-ester, phosphono or phosphonic acid partial ester groups, as well as basic groups, such as. B. amino, imino or ammonium groupings. Zwitterionic compounds with a tetrasubstituted, i.e. H. Quaternary ammonium groups are called betaines if they also have a covalently bound acid group in the molecule and the positive and negative charge is balanced intramolecularly.

In addition to sodium tripolyphosphate, which is contained in the detergent in amounts of preferably less than 30% by weight, in particular at most 20% by weight, the builder substances or builders are, above all, the water-soluble salts of complex-forming aminopolycarboxylic acids, phosphonic acid derivatives, polymeric carboxylic acids, polycarboxylic acids and copolymers of maleic anhydride with ethylene, propylene, vinyl methyl ether and so on. The fine-particle water-insoluble aluminosilicates of the zeolite A and zeolite X types are also suitable builders.

Water-soluble colloids of mostly organic nature are suitable as dirt carriers, 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. Polyvinyl pyrrolidone is also useful.

The foaming power can be regulated by combining suitable types of surfactants, for example by anionic, nonionic surfactants or soaps or by adding non-surfactant-like inhibitors. Non-surfactant foam inhibitors are e.g. B. aminotriazine derivatives, paraffins or silicones.

Among the compounds which serve as bleaching agents and which supply h ₂ O ₂ in water, the mono- and tetrahydrate of sodium perborate are of particular importance, bleaching components containing activator preferably being used for washing at temperatures in the range from 40 ° to 60 ° C. Organic or inorganic active chlorine compounds are also suitable bleaching agents; the latter include alkali hypochlorites in particular.

The enzymes to be used are, in particular, relatively resistant to alkalis, per-compounds and anionic surfactants and proteases, amylases or lipases which are still effective at washing temperatures.

Derivatives of diaminostilbenedisulfonic acid, in particular, can be used as optical brighteners for cotton; those of the 1,3-diaryl-2-pyrazolines and substituted aminocoumarins are suitable for polyamide fibers.

Post-treatment agents suitable for carrying out the process according to the invention contain customary textile softening agents, furthermore specific acidic compounds, if appropriate solubilizers, solvents and / or dispersants, preservatives, viscosity regulators, furthermore opacifiers, dyes and fragrances.

Commercially available compounds such as, for example, B. dimethyldistearylammonium chloride ("Präpagen-WK" Hoechst), further similar compounds with ether and hydroxyl groups in the long residues ("Fintex" Berol-Chemie), 1-ethylene bis (2-tallow-l-methylimidazolinium methyl sulfate) ("Varisoft 6112", Sherex company) into question. Likewise preferred are textile-softening amine salts with at least two C _n2 -C ₂₀ alkyl, hydroxyalkyl or alkenyl radicals. These salts can also be alkoxylated and, for example, in particular reaction products of 2 mol of 1,2-epoxytetradecane with 1 mol of dipropylenetriamine, to which 3 mol of ethylene oxide have been added and which have subsequently been converted into a salt with formic acid; the last-mentioned and similarly constructed compounds are known as textile plasticizers from German patent application P 30 23 947.5.

Suitable acidic additives are, for example, inorganic mineral acids and non-surface-active organic acids having 1 to 8 carbon atoms, such as, for example, amidosulfonic acid, boric acid, oxalic acid, lactic acid, glycolic acid, diglycolic acid, carboxymethylsuccinic acid, citric acid, tartaric acid, benzoic acid, phthalic acid, gluconic acid, acetic acid and formic acid

Propionic acid and benzene, toluene or xylene sulfonic acid, sulfoacetic acid or sulfobenzoic acids or acid alkali salts of these acids. A mixture of adipic acid, glutaric acid and succinic acid can also be used. Formic acid, glycolic acid and citric acid are preferred acids. Water is the primary solvent, possibly mixed with lower alcohols or glycol ethers.

If appropriate, dispersants to be added are in particular nonionic surfactants which owe their hydrophilic properties to the presence of polyether chains or, quite generally, to an accumulation of hydroxyl groups in the molecule. The products obtainable by adding ethylene oxide and / or propylene oxide to fatty alcohols, alkylphenols, fatty amines, fatty acid or sulfonic acid amides are of particular practical interest. The addition of emulsifiers such as. B. of Nonylphenol., To the 6.5. or 10 moles of ethylene oxide are attached, or C ₁₂ -C ₁₈ fatty alcohols, to which 2 to 5 moles of ethylene oxide and 4 or 5 moles of propylene oxide have been attached, are sometimes useful. It is often also appropriate to use silicone preparations, for example, for foam regulation.

• 1 - 15 Gew.-% Anionisches Tensid
• 1 - 15 Gew._-% Nichtionisches Tensid
• 0 - 50 Gew.-% Natriumalumosilikat
• 0 - 30 Gew.-% Natriumtripolyphosphat
• 0 - 3 Gew.-% Magnesiumsilikat
• 0,5 - 10 Gew.-% Wasserglas
• 0 - 40 Gew.-% Natriumperborat
• Rest Wasser sowie gegebenenfalls Natriumsulfat und geringe Mengen üblicher organische Komplexbildner, Schmutzträger, Schaumregulatoren, Enzyme, Duftstoffe, Farbstoffe, optischer Aufheller, Wasser

wobei der Gehalt an Natriumtripolyphosphat insbesondere nicht mehr als 20 Gew.-% beträgt und wobei vorzugsweise die Summe von Natriumtripolyphosphat und Natriumalumosilikat insgesamt nicht mehr als 40 Gew.-%, insbesondere nicht mehr als 30 Gew.-% ausmacht. Die Dosierung des Waschmittels in der Waschflotte wählt man dabei so, daß die Waschflotte pro Liter höchstens 0,3, insbesondere höchstens 0,1 g Phosphor als Phosphat enthält. Zweckmäßigerweise spült man die gewaschenen Textilien vor der Nachbehandlung einmal oder mehrmals mit Wasser.Low-phosphate or phosphate-free detergents which are particularly suitable for carrying out the process according to the invention have the following composition:

• 1 - 15% by weight of anionic surfactant
• 1 - 15 wt _-.% Nonionic surfactant
• 0 - 50% by weight sodium aluminosilicate
• 0-30% by weight sodium tripolyphosphate
• 0 - 3% by weight magnesium silicate
• 0.5-10% by weight water glass
• 0 - 40% by weight sodium perborate
• Remainder water and optionally sodium sulfate and small amounts of conventional organic complexing agents, dirt carriers, foam regulators, enzymes, fragrances, dyes, optical brighteners, water

wherein the content of sodium tripolyphosphate is in particular not more than 20% by weight and preferably the sum of sodium tripolyphosphate and sodium aluminosilicate is not more than 40% by weight, in particular not more than 30% by weight. The dosage of the detergent in the wash liquor is chosen so that the wash liquor contains at most 0.3, in particular at most 0.1 g, phosphorus per liter as phosphate. The washed textiles are expediently rinsed once or several times with water before the aftertreatment.

• 3 - 50 Gew.-% Textilweichmachende Wirkstoffe
• 1 - 20 Gew.-% Saure exkrustierende Verbindungen
• 0 - 20 Gew.-% Lösungsvermittler, Emulgatoren
• 0 - 10 Viskositätsstellmittel
• 0 - 3 Gew.-% Konservierungsstoffe
• Rest Wasser sowie gegebenenfalls in geringen Mengen Farbstoff, Duftstoff, optische Aufheller, Schaumregulatoren, Wasser

wobei das Nachbehandlungsmittel einen zur Auflösung von Inkrustationen erforderlichen aziden pH-Wert aufweist. Dabei werden in der Nachbehandlungsflotte pH-Werte von höchstens 4 eingestellt, um eine ausreichend rasche Exkrustierung zu gewährleisten; zweckmäßigerweise arbeitet man mit Flotten im pH-Wert-Bereich 2 bis 4.Suitable acidic aftertreatment agents have, for example, the following composition:

• 3 - 50 wt .-% textile softening agents
• 1 - 20 wt .-% acid excrusting compounds
• 0 - 20 wt .-% solubilizers, emulsifiers
• 0 - 10 viscosity adjusting agents
• 0 - 3% by weight of preservatives
• Rest of water and, if necessary, small amounts of dye, fragrance, optical brighteners, foam regulators, water

wherein the aftertreatment agent has an acidic pH value required to dissolve incrustations. PH values of a maximum of 4 are set in the aftertreatment liquor in order to ensure sufficient excrustation; it is expedient to work with liquors in the pH range 2 to 4.

The acidic additive used is preferably a mixture of several organic acids, in particular a mixture of citric acid, diglycolic acid, formic acid or glycolic acid consisting of 2 or 3 acids, with a weight ratio of 1 part citric acid, 4 parts formic acid and 6 parts glycolic acid being particularly preferred good excrusting effect.

The aftertreatment according to the invention with acidic agents can also be carried out by using more concentrated agents. These contain the active substances and additives in a correspondingly higher concentration, for example up to 50% by weight of textile-softening active substances, if appropriate with adaptation of the solvents and solubilizers. Such agents are either added to the aftertreatment bath in a smaller amount or are only diluted to the desired application concentration shortly before use.

The aftertreatment is preferably carried out using an aftertreatment liquor which contains 0.5 to 20 g per liter of an aftertreatment agent, the aftertreatment preferably being carried out at temperatures of 10 to 30 ° C. A treatment time of about 1 to 10 minutes is generally sufficient ....

Example: 1 e

In the following washing and post-treatment tests, the primary washing behavior was determined by specifying the whiteness of various white test textiles (cotton terry toweling (BW), polyester / cotton 65/35 (PES / BW) and polyacrylonitrile (PAN), table 1) and the secondary washing behavior the amount of incrustation on PES / BW Tab. 2 determined. Whiteness and incrustations were determined as follows:

Whiteness

With a spectrophotometer from Zeiss, type Elrepho, filter R 460, the reflectance of the test textiles was determined before the first wash (AW) and after 25 washing and post-treatment cycles and stated in%.

Incrustation

Tissue pieces of the test textiles with a known area made of polyester / cotton 65/35 were 30 min. treated with a 2N aqueous HCl solution at the boil. The sample neutralized against methyl red with 30% NaOH was titrated with n / 28 EDTA solution after dilution with water and addition of triethanolamine, buffer solution and an indicator buffer tablet. 1 ml of this solution corresponds to 1 mg CaO. The value converted to 10 cm ² tissue area represents the incrustation in mg Ca0 / 10 cm ² .

The test textiles were washed in an automatic household washing machine, type Miele W 433, using the one-lye process at 60 ° C. The machine was loaded with 2.8 kg of textiles, which were washed with 280 g of a detergent with a reduced amount of builders.

The aftertreatment was carried out in a treatment liquor which contained 3 g of aftertreatment agent per liter.

The detergent had the following composition:

The aftertreatment agent had the following composition:

The fabric softening agent was the formic acid salt of a reaction product of 2 moles of 1,2-epoxytetradecane with 1 mole of dipropylenetriamine, to which 3 moles of ethylene oxide were added. (Compare DE-OS 30 23 947). The agent (pH 2.1) had a pH of 3.6 after dilution to 3 g per liter.

The degree of whiteness and the incrustation were measured after 25 washing and post-treatment cycles. The corresponding initial values (AW) were used for comparison. A comparison was also made with the effect of a commercially available non-encrusting aftertreatment agent; with this agent, aftertreatment was carried out after each wash with the detergent forming incrustations with a reduced amount of builders. As a comparison, the whiteness and incrustation of the test textiles were also determined, which were washed 25 times with the above-mentioned detergent, and with a high-performance commercially available detergent that complies with the maximum level of phosphate in Level II, but has not been post-treated.

Der Tabelle 1 ist zu entnehmen, daß der Weißgrad der behandelten Prüftextilien tendenziell höher ist als der Ausgangswert (AW) der nichtgewaschenen und nichtnachbehandelten Textilien. Das erfindungsgemäße Verfahren liefert also ein Primärwaschergebnis, das zumindest auf üblichem Niveau liegt und etwa mit dem Ergebnis des leistungsfähigen handelsüblichen Waschmittels übereinstimmt.The following results were obtained:

It can be seen from Table 1 that the whiteness of the treated test textiles tends to be higher than the initial value (AW) of the unwashed and untreated textiles. The method according to the invention thus delivers a primary washing result which is at least at the usual level and roughly corresponds to the result of the high-performance commercially available detergent.

The characteristic differences between the method according to the invention and the method according to the prior art, in which a commercially available agent for aftertreatment is used, are shown in Table 2, in which the incrustation results after 25 washes and aftertreatments are listed. For comparison, the result after 25 washes without aftertreatment is again shown here.

It can be seen from this that the incrustation of tissue washed and aftertreated according to the invention is significantly less than that of the washed in the same way and aftertreated with a commercially available, non-encrusting aftertreatment agent or untreated test textile. The incrustation of the fabric aftertreated according to the invention is 0.11 mg CaO / 10 cm ² in the same order of magnitude as the incrustation values obtained using a high-performance commercial detergent with a very effective builder system.

The tissue not post-treated according to the invention shows markedly increased incrustation, which is no longer tolerable. The washing and aftertreatment according to the invention did not damage the test fabric, as the measurement of the tear strength after 25 washing and aftertreatment cycles showed.

Similar results were obtained when the same amount of commercially available dimethylditalgalkylammonium chloride was used as the textile-softening active ingredient instead of the acid salt in the aftertreatment agent mentioned above.

Claims (13)

1. Two-stage process for washing and post-treatment of textiles, comprising a textile cleaning process stage and an incrustation-dissolving process stage, characterized in that in a first process stage, the textiles in a maximum of as much phosphate per liter as 0.3 g of Phos. correspond to washing liquid containing phosphorus, formed from a phosphate-free or phosphate-free detergent dissolved in water, which allows the formation of incrustations and washes in a second step. afterwards treated with an acidic liquid agent containing incrustation-dissolving textile-softening active ingredients. 2. The method according to claim 1, characterized in that the textiles are cleaned in a washing liquor which contains at most 0.1 g phosphorus as phosphate and no or only so much phosphate-free builder substances that incrustations can occur on the textiles and that the textiles are then subsequently aftertreated. 3. The method according to claim 1 and 2, characterized in that the textiles in a washing liquor, which by dissolving a detergent of the following composition: 1 - 15% by weight of anionic surfactant 1-15% by weight of nonionic surfactant 0 - 50% by weight sodium aluminosilicate 0-30% by weight sodium tripolyphosphate 0 - 3% by weight magnesium silicate 0.5-10% by weight water glass 0 - 40% by weight sodium perborate Remainder water and optionally sodium sulfate and small amounts of conventional organic complexing agents, dirt carriers, foam regulators, enzymes, optical brighteners, dyes, fragrances, receives, with the proviso that the content of sodium tripolyphosphate is preferably not more than 20 wt .-% and that the sum of sodium tripolyphosphate and sodium aluminosilicate together is not more than 40 wt .-%, in particular not more than 30 wt .-% and then aftertreating the textiles in a second process step with an agent contained in a washing liquor. 4. Process according to claims 1 to 3, characterized in that the textiles are cleaned in the first process stage at a wash liquor temperature of 40 to 100 ° C, in particular from 60 to 95 ° C and then post-treated. 5. The method according to claims 1 to 4, characterized in that the textiles in a wash liquor containing 5 to 50 g of detergent according to claim 3 per liter, with the proviso that the wash liquor at most 0.3 g, in particular at most 0 , 1 g of phosphorus as phosphate, cleans and then treated. 6. Process according to claims 1 to 5, characterized in that the encrusted textiles are rinsed with water once or several times after the first cleaning step. 7. The method according to claims 1 to 6, characterized in that the cleaned incrusted textiles after the cleaning first process step according to claims 1 to 6 of an aftertreatment with an aftertreatment liquor which is an aftertreatment agent of the following composition 3 - 50 wt .-% textile softening agents 1 - 20 wt .-% acid excrusting compounds 0 - 20 wt .-% solubilizer 0 - 10% by weight viscosity control agent 0 - 3% by weight of preservatives Rest of water, as well as possibly in small amounts of foam regulators, optical brighteners, fragrances and dyes contains, aftertreated, the composition of the aftertreatment agent being chosen so that the treatment liquor has sufficient acidity to dissolve the incrustations. 8. The method according to claims 1 to 7, characterized in that the aftertreatment of the cleaned according to claims 1 to 6 textiles with a treatment liquor, the textile softening active compounds from the group of quaternary ammonium salts with at least two optionally substituted C ₁₂ -C ₂₀ Alkyl or alkenyl radicals, and amine salts containing at least two C ₁₂ -C ₂₀ alkyl, hydroxyalkyl or alkenyl radicals, which are optionally alkoxylated. 9. The method according to claims 1 to 7, characterized in that one carries out the aftertreatment of the textiles cleaned according to claims 1 to 6 in a treatment liquor which contains one or more organic acids as acidic compounds. L0. Process according to Claims 1 to 9, characterized in that the aftertreatment of the textiles cleaned according to Claims 1 to 6 is carried out in a treatment liquor which, as acidic compounds, contains citric acid, formic acid, diglycolic acid or glycolic acid individually or as a mixture of two or three acids, makes. L1. Process according to Claims 1 to 10, characterized in that the aftertreatment of the textiles cleaned according to Claims 1 to 6 is carried out in a treatment liquor which, as acidic compounds, contains a mixture of 1 part of citric acid, 4 parts of formic acid and 6 parts of glycolic acid. 12. The method according to claims 1 to 11, characterized in that one carries out the aftertreatment of the textiles cleaned according to claims 1 to 6 in a treatment liquor containing 0.5 to 20 g per liter of an aftertreatment agent according to claim 5. 13. The method according to claims 1 to 12, characterized in that one carries out the post-treatment of the cleaned according to claims 1 to 6 textiles in a treatment liquor at a temperature of about 10 to 3 0 ° C.