EP0356707A1 - Process for dosing pasty detergents - Google Patents

Abstract

PCT No. PCT/EP89/00877 Sec. 371 Date Feb. 1, 1991 Sec. 102(e) Date Feb. 1, 1991 PCT Filed Jul. 25, 1989 PCT Pub. No. WO90/01533 PCT Pub. Date Feb. 22, 1990.A unit consisting of a cartridge provided with a base plate displaceable under pressure is used for the program-controlled dosing of paste-form detergents. The orifice of the cartridge leads into the dispensing compartment of the washing machine, more particularly into the region of a spray jet or into a region of high turbulence of the inflowing water. The detergent paste consists of nonionic surfactants liquid at temperature below 10 DEG C. or mixtures thereof and, suspended therein, builder salts and washing alkalis having a particle size in the range from 5 to 40 mu m.

Description

The present invention relates to a method which is particularly suitable for carrying out in commercial laundries and is based on the new development of a pasty detergent which is fed into the washing process by means of a metering system which has been specifically matched to this agent.

Liquid to pasty detergents are known in large numbers. These are generally tailored to household needs. H. they should be sufficiently liquid and easy to pour and dose. Since they should also be stable in storage within a relatively wide temperature range, the use of organic solvents and / or hydrotropic additives is usually not possible. However, these additives are washing-inactive, comparatively complex and additionally require packaging volume or transport and storage capacity. A content of volatile flammable solvents, which require additional safety precautions, is particularly troublesome. Detergent concentrates of the type mentioned are therefore not or only of limited use for laundries.

Paste-like, essentially water-free detergents are also known, for example from US 4,115,308 and US 3,850,831. They also regularly contain washing-inactive liquid additives, such as polyglycols or triethanolamine, for the purpose of dispersing the finely divided builder salts and adjusting the viscosity, so that they can be easily expressed from a tube by hand pressure to let. In this form, they are unsuitable for use in washing machines that are equipped with conventional detergent dispensers. If the paste is dosed into these chambers, it is not dissolved and dispersed by the water supplied, but a superficial gel layer forms around the paste, which hinders the further dissolving process. The gel-like paste slides together with the flowing water into the lye drum, where due to its high specific weight it collects almost completely in the area of the drain socket and remains there practically until the end of the washing process. With the rinse water, the agent then enters the sewage system essentially unused.

Another disadvantage that has hindered the use of paste-like detergents in commercial laundries so far is packaging and metering problems. Tubes are unsuitable for this type of application because they are only suitable for limited fill quantities and handling them is labor-intensive and time-consuming. In most cases, too large residual amounts remain on the tube wall and in the tube head. The removal of viscous pastes from conventional storage containers by means of dosing spoons is also cumbersome and labor intensive and moreover leads to the flushing problems already described.

Powder detergents are therefore mainly used in laundry companies. Since the exact dosing of such agents is problematic or labor-intensive, especially in large companies with extensive automation, the agents are usually stored and metered in pre-dissolved form as base liquors, i.e. an aqueous concentrate is prepared which is then fed to the individual consumption points. However, the detergents usually used in laundries contain comparatively high proportions of washing alkalis, which are only soluble in cold water to a limited extent and also cause salting-out effects to lead. They cause phase separation, with the result that the organic components, in particular the nonionic surfactants and soaps, separate and cream. It is therefore necessary to work in a relatively strong aqueous dilution and to mix the stock liquors continuously and intensively in order to prevent the separation of individual components in the supply lines to the consumption points. Such processes therefore require high investments for spacious batch containers and the associated statics as well as for mixers and conveyors as well as a constant supply of energy for tempering and pumping around the stock liquors.

There is therefore a considerable need for detergent compositions and coordinated metering devices with which the above problems are avoided and which meet the following requirements:
- high washing power
- No washing-active additives that only serve to condition the detergent
- low need for packaging, transport and storage volume
- Easy processing even at low temperatures or from supercooled pastes
- Easy connection to the dosing system while avoiding bulk loss and residues in the packaging
- Easy and space-saving to install dosing system
- Suitability of the system for process-dependent control of the dosing time and the dosing quantity
- Extensive variability in the choice of the amount of detergent and the concentration of detergent
- Security against malfunctions caused by gel formation and settling in the tub
- low energy consumption.

These problems are solved with the present invention.

• A) eines pastenförmigen, strukturviskosen, phosphatreduzierten bis phosphatfreien Waschmittels, das von Wasser, organischen Lösungsmitteln und hydrotropen Verbindungen im wesentlichen frei ist, bestehend aus einer im Temperaturbereich unterhalb 10 °C flüssigen Phase, die aus nichtionischen Tensiden aus der Klasse der Polyglykoletherverbindung gebildet wird, sowie einer darin dispergierten festen, partikelförmigen Phase, die aus Waschalkalien, sequestrierend wirkenden Verbindungen und sonstigen Waschmittelbestandteilen sowie gegebenenfalls anionischen Tensiden gebildet wird, ferner
• B) eines druckfesten Behälters für das pastenförmige Waschmittel, bestehend aus einem Hohlzylinder, der einseitig mit einer in Richtung der Zylinderachse innerhalb des Behälters verschieb­baren Platte verschlossen ist und an seiner Gegenseite eine Austrittsöffnung und ein lösbares Verbindungselement aufweist, mit dem der Behälter an der Vorrichtung (C) befestigt werden kann,
• C) einer in Abhängigkeit von der eingespeisten Wassermenge oder der Konzentration der Waschlauge gesteuerten Dosiervorrich­tung, bestehend aus einem auf die verschiebbare Verschluß­platte des Behälters einwirkenden Druckstempel und einer mit der Austrittsöffnung des Behälters über das lösbare Verbin­dungselement verbundenen Austrittsdüse für das pastenförmige Mittel, wobei die Austrittsdüse, die mit einer steuerbaren Ab­sperrung versehen sein kann, innerhalb der Einspülkammer der Waschmaschine so angeordnet ist, daß sich ihre Mündung im Bereich des Sprühstrahls bzw. einer erhöhten Turbulenz des eingespeisten Wassers befindet.

The invention relates to a method for dosing detergents, characterized by the use

• A) a pasty, structurally viscous, phosphate-reduced to phosphate-free detergent which is essentially free of water, organic solvents and hydrotropic compounds, consisting of a phase which is liquid in the temperature range below 10 ° C. and which is formed from nonionic surfactants from the class of the polyglycol ether compound, and a solid, particulate phase dispersed therein, which is formed from washing alkalis, sequestering compounds and other detergent constituents and, if appropriate, anionic surfactants
• B) a pressure-resistant container for the pasty detergent, consisting of a hollow cylinder which is closed on one side with a plate which can be displaced in the direction of the cylinder axis within the container and on its opposite side has an outlet opening and a releasable connecting element with which the container can be attached to the device ( C) can be attached
• C) a metering device which is controlled as a function of the amount of water fed in or the concentration of the wash liquor, consisting of a pressure stamp acting on the displaceable closure plate of the container and an outlet nozzle for the paste-like agent connected to the outlet opening of the container via the releasable connecting element, the outlet nozzle, which can be provided with a controllable shut-off, is arranged within the dispenser of the washing machine so that its mouth located in the area of the spray jet or an increased turbulence of the water fed in.

There now follows a description of the individual features of the inventions.

A) Detergent

The detergent consists of a paste that is essentially free of water and organic solvents. “Substantially free of water” is understood to mean a state in which the content of liquid water, ie water not in the form of water of hydration and constitutional water, is below 2% by weight, preferably below 1% by weight and in particular below 0 , 5% by weight. Higher water contents are disadvantageous because they increase the viscosity of the agent disproportionately and reduce the stability. Organic solvents, which include the low molecular weight and low-boiling alcohols and ether alcohols commonly used in liquid concentrates, as well as hydrotropic compounds, are also absent, apart from traces that can be introduced with individual active ingredients.

The detergent consists of a liquid phase and a finely divided phase dispersed therein.

The liquid phase consists essentially of nonionic surfactants or surfactant mixtures melting at temperatures below 10 ° C. It is advisable to use surfactants or their mixtures whose pour point (solidification point) is below 5 ° C, so that solidification of the paste at lower transport and storage temperatures is avoided. Examples of such surfactants are e.g. B. alkoxylated alcohols, which are linear or methyl branched in the 2-position (Oxo can be alcohols), and have 9 to 16 carbon atoms and 2 to 10 ethylene glycol ether groups (EO). Alkoxylates which have both EO groups and propylene glycol ether groups (PO) are also suitable because of their low pour point. Examples of suitable nonionic surfactants are:
C₉₋₁₁ oxo alcohol with 2 to 10 EO, such as C₉₋₁₁ + 3 EO, C₉₋₁₁ + 5 EO, C₉₋₁₁ + 7 EO, C₉₋₁₁ + 9 EO;
C₁₁₋₁₃ oxo alcohol with 2 to 8 EO, such as C₁₁₋₁₃ + 2 EO, C₁₁₋₁₃ + 5 EO, C₁₁₋₁₃ + 6 EO, C₁₁₋₁₃ + 7 EO;
C₁₂₋₁₅ oxo alcohol + 3 - 6 EO, such as C₁₂₋₁₅ + 3 EO, C₁₂₋₁₅ + 5 EO;
Isotridecanol with 3 to 8 EO;
linear fatty alcohols with 10 to 14 carbon atoms and 2.5 to 5 EO;
linear or branched C₉₋₁₄ alcohols with 3 to 8 EO and 1 to 3 PO, such as C₉₋₁₁ oxo alcohol + (EO) ₄ (PO) ₁₋₂ (EO) ₄ or - C₁₁₋₁₃ oxo alcohol + ( EO) ₃₋₁₀ (PO) ₁₋₅ with randomly distributed alkoxyl groups;
linear saturated and unsaturated C₁₂₋₁₈ fatty alcohols or C₉₋₁₅ oxo alcohols with 1 to 3 PO and 4 to 8 EO, such as C₁₂₋₁₈ coconut alcohol + (PO) ₁₋₂ (EO) ₄₋₇, oleyl alcohol or 1 : 1-mixture of cetyl oleyl alcohol + (PO) ₁₋₂ (EO) ₅₋₇, C₁₁₋₁₅-oxo alcohol + (PO) ₁₋₂ (EO) ₄₋₆.

Also ethoxylated alcohols, the terminal hydroxyl groups of which are alkylated by lower alkyl groups, are suitable due to their low pour point within the scope of the invention, for example a C₁₀₋₁₄ alcohol having 3 to 10 EO groups and a terminal methoxyl group. Other suitable nonionic surfactants are EO-PO-EO block polymers with a correspondingly low pour point and ethoxylated alkylphenols, such as nonylphenol with 7 to 10 EO. However, the latter surfactants can be excluded from use in individual areas because of their reduced biodegradability. They are therefore less preferred.

The content of the nonionic surfactants mentioned in the pastes should be such that, on the one hand, they are still sufficiently flowable and pumpable under the influence of shear forces, and on the other hand are so stiff or viscous at rest that no separation occurs even during long standing times. Pastes with a content of 15 to 35% by weight, preferably 18 to 30% by weight and in particular 20 to 25% by weight, of liquid nonionic surfactants with a low pour point (below 5 ° C.) are suitable. If surfactants with a higher pour point, for example that of 5 to 20 ° C., are used in a mixture with particularly low-melting surfactants, the minimum content is somewhat higher, for example in the range from 18% by weight, preferably from 22 to 24% by weight. , the maximum content being 35% by weight, preferably 30% by weight.

In individual cases, a single nonionic surfactant can already have the desired requirements with regard to low pour point, favorable flow behavior, high detergency and low foaming. An example of this are oleyl alcohol or mixtures rich in oleyl alcohol, which was first reacted with 1 to 2 PO and then with 5 to 7 EO. However, particularly favorable properties are often achieved with mixtures of nonionic surfactants with different degrees of ethoxylation and possibly different C chain lengths. Mixtures of nonionic surfactants with a low degree of ethoxylation and a low pour point, for example C₉₋₁₅ alcohols with 2 to 5 EO, and those with a higher degree of ethoxylation and a higher pour point, for example C₁₁₋₁₅ alcohols with 5 to 7 EO, are therefore particularly preferred. The mixing ratio between the two alcohol ethoxylates is based both on the washing requirements and the flow behavior of the washing paste and is generally between 15: 1 to 1: 3, preferably 8: 1 to 1: 1. Examples of this are a mixture of 2 parts by weight of C₉₋₁₁-oxo alcohol + 2.5 EO and 1 part by weight of C₁₁₋₁₃-oxo alcohol + 7 EO or a mixture of 3 parts by weight of a C₁₁₋₁₄ oxo alcohol + 3 EO and 2 parts by weight of a C₉₋₁₃ oxo alcohol + 8 EO and a mixture of 7 parts by weight of C₁₃ oxo alcohol + 3 EO and 1 part by weight of the same alcohol + 6 EO.

Finally, the flow properties of the pastes can be modified by adding low molecular weight polyethylene glycols (e.g. 200 to 800). The addition can be up to 15% by weight, for example. However, the contribution of these additives, which are often also included in the nonionic surfactants, to the detergency is comparatively low. However, they can have a foam-suppressing effect and are therefore desirable. Their proportion is preferably up to 10% by weight, in particular 0.5 to 8% by weight.

The polyglycols can also be replaced in whole or in part by paraffin oils or liquid paraffin mixtures, which do not contribute to the washing power, but make the paste easier to process, especially during the grinding of the ingredients, and bring about a considerable reduction in foam, which is particularly noticeable in the rinse cycle makes. The proportion of such paraffin oils or paraffin oil mixtures is expediently not more than 8% by weight, preferably not more than 6% by weight. Liquid long-chain ethers can also be used in the same amount for the same purpose. Examples include the C₈₋₁₆ alkyl ethers of dicyclopentenol.

The detergent contains a solid phase that is homogeneously dispersed in the liquid phase and the rest of it is cleaning kenden detergent ingredients and optionally auxiliaries. These other detergent components which have a cleaning action primarily include washing alkalis and sequestering compounds. Anionic surfactants, in particular those from the class of the sulfonate surfactants and the soaps, can also be present.

The preferred washing alkali is sodium metasilicate of the composition Na₂O: SiO₂ = 1: 0.8-1: 1.3, preferably 1: 1, which is used in anhydrous form. In addition to the metasilicate, anhydrous soda is also suitable, but due to absorption processes it requires larger proportions of the liquid phase and is therefore less preferred. The proportion of the agents in metasilicate can be 35 to 70% by weight, preferably 40 to 65% by weight and in particular 45 to 55% by weight, and in soda 0 to 20% by weight, preferably 0 to 10% by weight. -%.

Suitable sequestrants are those from the class of aminopolycarboxylic acids and polyphosphonic acids. The aminopolycarboxylic acids include nitrilotriacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid and their higher homologues. Suitable polyphosphonic acids are 1-hydroxyethane-1,1-diphosphonic acid, aminotri- (methylenephosphonic acid), ethylenediaminetetra- (methylenephosphonic acid) and their higher homologs, such as. B. Diethylenetraminetetra (methylenephosphonic acid). The aforementioned polycarboxylic acids or polyphosphonic acids are usually used in the form of the sodium or potassium salts. Sodium nitrilotriacetate is preferably used in proportions of up to 10% by weight, preferably 2 to 6% by weight.

Suitable sequestering agents are also polycarboxylic acids or hydroxypolycarboxylic acids in the form of the alkali metal salts, for example sodium citrate and sodium gluconate.

The sequestering agents preferably used include homopolymeric and / or copolymeric carboxylic acids or their sodium or potassium salts, with the sodium salts being preferred. Suitable homopolymers are polyacrylic acid, polymethacrylic acid and polymaleic acid. Suitable copolymers are those of acrylic acid with methacrylic acid or copolymers of acrylic acid, methacrylic acid or maleic acid with vinyl ethers, such as vinyl methyl ether or vinyl ethyl ether, furthermore with vinyl esters, such as vinyl acetate or vinyl propionate, acrylamide, methacrylamide and with ethylene, propylene or styrene. In those copolymeric acids in which one of the components has no acid function, the proportion thereof in the interest of sufficient water solubility is not more than 70 mole percent, preferably less than 60 mole percent. Copolymers of acrylic acid or methacrylic acid with maleic acid, such as are characterized, for example, in EP 25 551-B1 have proven to be particularly suitable. These are copolymers which contain 50 to 90% by weight of acrylic acid or methacrylic acid and 50 to 10% by weight of maleic acid. Copolymers in which 60 to 85% by weight of acrylic acid and 40 to 15% by weight of maleic acid are present are particularly preferred.

Also useful are polyacetal carboxylic acids, such as those described in U.S. Patents 4,144,226 and 4,146,495, which are obtained by polymerizing esters of glycolic acid, introducing stable terminal end groups, and saponifying to the sodium or potassium salts. Also suitable are polymeric acids which are obtained by polymerizing acrolein and disproportionating the polymer according to Canizzaro using strong alkalis. They are essentially made up of acrylic acid units and vinyl alcohol units or acrolein units.

The molecular weight of the homo- or copolymers is generally 500 to 120,000, preferably 1,500 to 100,000.

The proportion of the agents in polyacids or polymer acids containing carboxyl groups is 0 to 10% by weight, preferably 1 to 7.5% by weight and in particular 2 to 5% by weight, and that of polyphosphonic acids 0 to 3% by weight. , preferably 0.05 to 1.5% by weight and in particular 0.1 to 1% by weight. They are used in an anhydrous form.

The washing pastes are preferably phosphate-free. If a phosphate content is ecologically harmless (for example in the case of wastewater treatment that eliminates phosphates), polymeric phosphates, such as sodium tripolyphosphate (STP), can also be present. Their proportion can be up to 20% by weight, based on the agent, the proportion of the other solids, e.g. B. the sodium silicate, is reduced accordingly. The proportion of the STP is preferably at most 15% by weight and in particular at most 10% by weight.

Fine-particle zeolites of the NaA type which have a calcium binding capacity in the range from 100 to 200 mg CaO / g (according to the information in DE 24 12 837) are also to be regarded as sequestering agents in the sense of the present invention. Their particle size is usually in the range of 1-10 µm. They are used in dry form. The water contained in bound form in the zeolites does not interfere in the present case. The zeolite content is 0 to 20% by weight, preferably 0 to 10% by weight.

Anionic surfactants come in as further cleaning additives which can be incorporated into the detergent in solid, fine-particle, largely anhydrous form Question. Sulfonates and fatty acid soaps, which are preferably present as sodium salts, have proven to be particularly suitable. Suitable are alkylbenzenesulfonates with linear C₉₋₁₃ alkyl chains, especially dodecylbenzenesulfonate, linear alkanesulfonates with 11 to 15 carbon atoms, as can be obtained by sulfochlorination or sulfoxidation of alkanes and subsequent saponification or neutralization, alphasulfofatty acid salts and their esters, which are derived from saturated C₁₂₋₁₈ fatty acids and lower alcohols such as methanol, ethanol and propanol, and olefin sulfonates such as those used for. B. by SO₃-sulfonation final C₁₂₋₁₈ olefins and subsequent Akalic hydrolysis. Preferred surfactants are alkylbenzenesulfonates. Suitable soaps are those of saturated and / or unsaturated C₁₂₋₁₈ fatty acids, for example soaps obtained from coconut, palm kernel or tallow fatty acids. In the interest of a low foaming rate when using the compositions, the proportion of the sulfonate surfactants should not exceed 4% by weight, based on the composition. It is preferably 0.5 to 2.5% by weight of sodium dodecylbenzenesulfonate. An addition of sulfonate surfactant not only increases the washing power, but also improves the stability of the pastes against signs of sedimentation and facilitates the dispersion of the paste in the water. Surprisingly, it has also been found that the sulfonate surfactant essentially distributes itself in the liquid phase and improves the solid / liquid balance in favor of the liquid phase. Pastes containing sulfonate surfactants can therefore absorb larger amounts of solids, or the proportion of nonionic surfactant can be reduced accordingly without any appreciable increase in viscosity.

An addition of soap, which can be up to 1% by weight, preferably up to 0.5% by weight and in particular 0.1 to 0.3% by weight, based on the composition, likewise increases the suspension stability of the paste. Such an addition also reduces the tendency to foam and improves the washing power of the compositions. Larger proportions than 1 to 2% by weight can solidify the paste and should therefore be avoided.

Washing aids can be considered as further constituents, which are also predominantly assigned to the solid phase. These include graying inhibitors, optical brighteners, foam inhibitors, bleaches and dyes. Insofar as fragrances are used which are generally liquid, these pass into the liquid phase. Because of their small amount, however, they have no appreciable influence on the flow behavior of the pastes.

Suitable graying inhibitors are cellulose ethers, such as carboxymethyl cellulose, methyl cellulose, hydroxyalkyl celluloses and mixed ethers, such as methyl hydroxyethyl cellulose, methyl hydroxypropyl cellulose and methyl carboxymethyl cellulose. Na carboxymethyl cellulose and mixtures thereof with methyl cellulose are preferably used. The proportion of graying inhibitors is generally 0.2 to 2% by weight, preferably 0.5 to 1.5% by weight.

In particular, derivatives of diaminostilbenedisulfonic acid or its alkali metal salts are included as optical brighteners for textiles made from cellulose fibers (cotton). Are suitable for. B. salts of 4,4'-bis (2-anilino-4-morpholino-1,3,5-triazin-6-yl-amino) -stilbene-2,2'-disulfonic acid or compounds of the same structure, which instead of Morpholino group carry a diethanolamino group, a methylamino group or a 2-methoxyethylamino group. Brighteners of the substituted 4,4'-distyryl-diphenyl type may also be present; e.g. B. the compound 4,4-bis (4-chloro-3-sulfostyryl) diphenyl. Mixtures of brighteners can also be used. For polyamide Fibers are brighteners of the 1,3-diaryl-2-pyrazoline type, for example the compound 1- (p-sulfamoylphenyl) -3- (p-chlorophenyl) -2-pyrazoline, and compounds of the same structure. The content of optical brighteners or brightener mixtures in the composition is generally 0.01 to 1% by weight, preferably 0.05 to 0.5% by weight.

Known polysiloxane-silica mixtures are suitable as foam inhibitors, the fine-particle silica contained therein preferably being silanated. The polysiloxanes can consist both of linear compounds and of crosslinked polysiloxane resins and of their mixtures. Other suitable defoamers are paraffin hydrocarbons, including the paraffin oils already mentioned, but also microparaffins and paraffin waxes, the melting point of which is above 40 ° C. Usable defoamers are also saturated fatty acids or soaps with 18 to 24, preferably 20 to 22 carbon atoms, for. B. sodium behenate. The proportion of additional, i.e. H. Foam inhibitors beyond the paraffin oil can be up to 2% by weight, preferably up to 1% by weight, correspondingly less in the case of soaps. In many cases, however, a suitable selection of the nonionic surfactants can reduce the tendency to foam, so that the use of defoamers can be dispensed with.

Bleaching agents can also be present as a further component of the solid phase. Per compounds such as sodium perborate monohydrate, caroates (KHSO₅) and organic peracids such as perbenzoates or peroxyphthalates can be used. These per-compounds are stable in storage in the claimed compositions because of the substantial absence of water. If appropriate, known bleach activators can also be present, which, when water is added, form with the per-compounds to form Hydrolyze peracids, for example tetraacetylethylenediamine or phthalic anhydride. Since in commercial laundries the bleaching component is often added separately to the wash liquor and is generally only used when there is a particular need, bleaching agents in the paste can also be dispensed with in such cases.

The components contained in the solid phase should be finely divided. A particulate phase has proven to be particularly advantageous, the components of which have an average grain size of 5 to 40 μm, with at most 10% of the particles having a grain size of more than 80 μm. The average grain size is preferably 10 to 30 μm and in particular 10 to 20 μm, the maximum grain size being below 100 μm, in particular below 80 μm. The average particle size relates to the volume distribution, which is determined by known methods (e.g. Coulter Counter).

The viscosity of the pastes is in the range from 20 Pa.s to 1,000 Pa.s (Pascal. Sec), measured at 20 ° C according to Brookfield 6/10 (spindle no. 6 at 10 revolutions per minute). The preferred viscosity range is 30 to 300 Pa.s, in particular 50 to 150 Pa.s. The pastes are thixotropic. At room temperature their viscosity is so high without the use of shear forces that under the exclusive influence of gravity they do not flow out of the storage container, or not in the time or quantity required for the intended application. In this respect, they differ fundamentally from known water-free, pourable liquid concentrates, for example those according to EP 30 096, US 3,850,831 and US 4,115,308, in which the proportion of liquid nonionic surfactants or organic solvents is significantly higher, and consequently also the viscosity or kinematic toughness is much lower.

For the production of the pasty detergents, the liquid constituents, which are expediently heated to temperatures of 40 ° C. to 60 ° C., are premixed with the solids already in powder form. The premix is then ground in a grinding device, for example a colloid mill, to the particle size specified for the solid phase and homogenized, excessive heating of the product being avoided by suitable cooling of the device. If necessary, the homogenized paste is degassed under vacuum in a ventilation system. Thereafter, thermally sensitive recipe components such as fragrances, dyes, organic per-compounds, layered silicates and soaps can be added to serve as the final viscosity adjustment. The finished paste can be filled directly into the packaging container.

B) Detergent dispenser

The detergent container is cylindrical and has an opening on both sides. One of the two openings is closed with a plate which is arranged inside the container and can be displaced in the direction of the axis of the container. The displaceable plate should largely seal the container wall in such a way that the paste is prevented from escaping in this area, ie the plate is advantageously displaced with slight friction on the container wall. The plate can be flat or slightly curved inwards. In order to avoid tilting or tilting of the movable plate, its edge is expediently bent outward in the form of a collar, ie the plate is designed as a flat piston. Such a design that fits as closely as possible simultaneously improves the seal. In this version, the slidable plate can be used as one-sided Serve container closure during shipping and storage of the container filled with the paste. It can additionally be secured with a film which can be removed or which yields under increased pressure or a predetermined breaking point.

The container opening located opposite the displaceable plate can comprise the entire cross section of the container or can be narrowed relative to this cross section. In the first case, the opening is designed like that of an open cartridge, in the second case, for example, like that of a tube head. The container opening carries, preferably on its outside, a releasable connecting element with which it can be attached or coupled to the metering device. This connecting element can consist, for example, of a screw thread (external thread), a bayonet lock, a groove or a circumferential ring. During shipping and storage of the filled container, the outlet opening is provided with a closure which expediently engages in the connecting element and can consist, for example, of a screw cap or a closure cap with a bayonet ring. An elastic, removable cap or a tearable film can also be used for this purpose.

If the closure is designed like a tube head, ie with a narrowed outlet opening, its inner surface, which points in the direction of the displaceable plate, should be designed in such a way that in the emptied state, no or only minimal amounts of paste remain. Depending on the shape of the slidable plate, the inside of the tube head can therefore be flat or curved. In addition, the displaceable plate can carry a cylindrical or conical extension on the inside, which in the most advanced position projects into the outlet nozzle of the tube head and also the ejects paste residues contained therein. This approach can be made hollow on the outside. The resulting recess can simultaneously serve to fix the ram during the dosing process.

The container is made of a corrosion-resistant, i.e. H. made of a washing paste or an aqueous detergent solution that cannot be attacked, such as plastic, metal or glass. With the applied pressures, which are in the range of 1 to 10 kg / cm², mostly 1 to 5 kg / cm², they should remain largely dimensionally stable in the interest of a sufficient fit. The size of the containers is not critical per se, but the contents should expediently be sufficient for several operating hours in order to minimize the packaging and operating effort. The capacity should therefore be at least 0.2 liters and not more than 20 liters, preferably 0.5 to 10 liters. Larger containers are comparatively bulky and complex to manufacture.

C) dosing device

The dosing device essentially consists of the following elements:
a detachable connecting element for the detergent container, with which it can be coupled to the metering device,
an outlet nozzle which leads into the washing-in chamber of the washing machine and whose mouth is in the area of the spray jet or an increased turbulence of the water fed in,
a press ram, which acts on the displaceable plate of the detergent container,
optionally a shut-off device for the washing paste arranged in the area of the outlet nozzle,
- A control device that controls the advance of the ram or the opening time of the shut-off device in the area of the outlet nozzle depending on the water supply or the detergent concentration in the wash liquor.

The connecting element is designed in such a way that it enables a firm connection with the coupled paste container that is sufficiently sealed against paste leakage. Screw connections and bayonet locks have proven themselves well here. If there is sufficient fit, additional sealing elements or sealing rings may not be necessary. Squeeze rings or ring-shaped coupling elements which engage a correspondingly designed groove or a circumferential ring or a crank at the outlet nozzle of the paste container and are automatically actuated, for example pneumatically or hydraulically, can advantageously be used.

The metering device has a pressure stamp which acts on the displaceable plate of the paste container and drives it forward when the paste is removed. The propulsion can be carried out pneumatically, hydraulically or mechanically, for example by means of a toothed rack, threaded spindle or by means of eccentrics. If no additional shut-off device is provided in the outlet nozzle, the advance is controlled in order to ensure an exact dosage of the paste. However, an arrangement is preferably selected in which the press ram constantly exerts a certain pressure on the displaceable plate and the paste is removed and metered by a process-controlled shut-off device which is arranged in the region between the connecting element and the outlet nozzle. The ram is actuated hydraulically in the simplest case by the pressure of the water pipe. Such an arrangement is at the same time particularly unaffected by interference fluctuating or absent water pressure, since a change in the water pressure and thus the amount to be flushed in is immediately compensated for by a corresponding change in the paste pressure and the corresponding amount of paste dispensed.

The outlet nozzle is intended to guide the paste within the induction chamber into an area in which the water exerts the highest possible shear forces on the paste. This ensures that the paste is broken down into small, rapidly distributing and dissolving particles. This effectively prevents the formation of a critical gel state.

Such an undesirable gel state regularly develops when water acts on a paste of the specified composition without increased shear force. The non-ionic surfactants then swell to form a viscous, gel-like mass which prevents further water from entering. The resulting slime does not dissolve in the flowing water at a sufficient speed and, due to its comparatively high specific weight, glides very quickly into the lowest area of the suds container or the drain socket of the washing machine, where it remains until the washing liquor is pumped out and is therefore lost to the washing process .

These disadvantages are completely avoided by the described arrangement of the outlet nozzle and the specified work cycle. Conductivity measurements show that the distribution and dissolution process takes only seconds. This is a prerequisite for the dosing process to also be controlled via the conductivity of the wash liquor. This is particularly advantageous if the water pressure is subject to strong fluctuations or if the wash liquor concentration is to be individually and automatically adjusted to the degree of soiling of the laundry and thus also the pollution of the liquor. A control depending on the degree of soiling of the laundry enables a particularly efficient utilization of the detergent and requires less waste water.

At its mouth, the outlet nozzle is expediently narrowed and has an inside diameter of 0.5 to 10 mm, preferably 1 to 6 mm.

A shut-off device, for example a shut-off valve or a valve, can be installed at a suitable point in the area between the connecting element and the mouth of the outlet nozzle. The shut-off device can be opened and closed pneumatically, hydraulically or by means of a servomotor. Such a shut-off device is mandatory if the pressure stamp, as described above, is under constant pressure and is not moved in a controlled manner. In this preferred arrangement, the opening and closing of the shut-off device is process-controlled, specifically as a function of the amount of water fed in or, particularly preferably, as a function of the conductivity of the wash liquor. The last-mentioned procedure enables a particularly exact adaptation to the pollution of the alkali and, if necessary, a dosing of washing paste.

Controlling the dosing process requires comparatively little effort. In the simplest case, this can be done using the automatic induction system that is already installed in the washing machine. It has proven to be expedient to control the water supply and the addition of the paste in such a way that initially a small part of the total amount of water supplied is initially introduced, then the paste in the indicated amount Is fed in and then rinsed for a while. In the case of a metering based on conductivity, it is advisable to end the addition of the paste at an earlier point in time because of the slightly delayed dissolution process. The final alkali concentration and the corresponding conductivity of the alkali then set a few seconds, a maximum of 30 seconds later. But a simple timer can also be used to achieve good results that are adapted to the respective requirements.

The emptied containers can be repeatedly refilled and reused or, if the material required is low, can also be discarded as disposable packaging.

The concentration of the wash liquor is in the range from 0.5 to 10 g / l. It is based on the degree of soiling of the laundry, ie in the case of less soiled laundry the application concentration is generally 0.5 to 5 g / l, in the case of heavily soiled laundry 5 to 10 g / l. In special cases, e.g. B. in heavily soiled work clothes, the concentration can be even higher and be, for example, 12 g / l. In general, it is 2 to 8 g / l. The liquor ratio (kg of textile to liter of wash liquor) is generally 1: 2 to 1:10, preferably 1: 4 to 1: 6. Usually, softened (permuted) water is used, and also for rinsing, at least for the first rinse cycle , usually softened water is used. Basically, the washing process in the machine does not differ significantly from the conventional working methods, with the exception that (as explained above) the detergent can be automatically replenished if there is an increased demand as a result of heavy soiling.

Examples

1. The detergent batch (200 kg) contained the following anhydrous components (in% by weight):
24.0% nonionic surfactant
2.0% Na dodecylbenzenesulfonate
8.5% Na nitrilotriacetate
55.0% Na metasilicate (1: 1)
8.5% pentasodium triphosphate
1.5% cellulose ether
0.5% optical brightener

A mixture of saturated C₁₂ ein₁₄ fatty alcohol + 3 EO and C₁₂₋₁₄ fatty alcohol + 5 EO in a weight ratio of 1: 1 with a freezing point (pour point) of 5 ^° C. was used as the nonionic surfactant.

The mixture was milled in a milling device (colloid mill type SZEGO-1) for 30 minutes. The ground product (outlet temperature 45 ^o C) had a mean particle size of 18.6 .mu.m and a viscosity of 50 Pa.s (Brookfield 6/10 at 20 ^o C). 0.1% of a dye was mixed in a cooled paste mixing kettle with a wall scraper. The end product was a storage-stable, pumpable paste with a specific weight of 1.7 g / ml. A wash liquor produced with this was slightly foaming and had a high washing power.

The paste was in cylindrical plastic cartridges (wall thickness 2 mm) with an outer diameter of 10 cm, a total length of 32 cm and a capacity of 2.2 liters bottled. The sliding, flat base plate had a circumferential, collar-shaped edge of 12 mm in height (measured from the flat surface). On the open opposite side of the cartridge, bayonet-like connecting elements were attached to the outer edge of the cartridge, with which the cartridge could be attached with the opening facing downwards to the connecting piece of the metering device. The seal between the nozzle and the cartridge was made using an elastic sealing ring. The connection piece ended in a connecting pipe in which a shut-off valve was rotatably attached. The further continuation of the connecting pipe ended in a nozzle with an inner diameter of 2 mm. The mouth of this nozzle was directed directly onto the upper edge of the sprayed-in water jet, so that the emerging paste was carried along by it and dispersed. The shut-off valve was connected to an electrically operated servomotor, the function of which was regulated by an automatic control device via a conductivity sensor arranged in the washing drum. The regulation was carried out in such a way that initially about 10% of the total water required was fed in without paste addition. At the same time, this water was used to remove small incrustations, which sometimes formed after a long period of standing under the influence of moisture at the nozzle mouth. The paste was then added until the pre-programmed conductivity value was reached, followed by a further addition of water until the required liquid level was reached.

The necessary pressing pressure on the movable base plate was carried out by means of a hydraulically operated pressure stamp. The pressure corresponded to the line pressure of the feed water and was 1.5 kg / cm². It was only switched off during long idle times in the car wash.

2. Example 1 was repeated using 57 wt .-% metasilicate and 22 wt .-% of a nonionic surfactant mixture of 2 parts by weight of C₉₋₁₁-oxo alcohol with 5 EO and 1 part by weight of C₁₂₋₁₃-oxo alcohol with 6 EO. The average grain size of the millbase was 16.5 µm, the viscosity 54 Pa.s (Brookfield 16/20 at 20 ^o C). This mixture was also stable in storage, pumpable and meterable and, when diluted with water, gave low-foaming solutions with comparable properties.

3. Example 1 was repeated, replacing 0.2% by weight of the nonionic surfactant with the same amount of sodium tallow soap. The viscosity of the paste increased to 68 Pa.s. The aqueous bases had a particularly low tendency to foam.

4. A paste of the following composition was produced (in% by weight):
17.5% C₁₃ oxo alcohol + 3 EO
2.5% C₁₃ oxo alcohol + 6 EO
2.0% Na dodecylbenzenesulfonate
8.0% polyethylene glycol (MG 400)
7.5% 3: 1 acrylic acid-maleic acid copolymer (MW 70,000), present as sodium salt
2.5% ethylenediaminetetra (methylenephosphonate), Na₆ salt
5.0% Na nitrilotriacetate
52.5% Na metasilicate
2.0% cellulose ether
0.3% optical brightener
0.2% Na tallow soap

The abbreviation MG means molecular weight. The processing of the components into a homogeneous, stable paste was carried out analogously to the manner given in Example 1. The average grain size was 17.0 µm, with no fractions with one grain size over 40 µm. The viscosity was 76 Pa.s (according to Brookfield 6/10) at 20 ° C. With regard to its usage properties, the paste corresponded to the agent according to Example 1 with an even lower tendency to foam, especially during the rinsing phase.

5. Compared to Example 4, the polyethylene glycol ether was replaced by a 1: 1 mixture of paraffin oil and a lauryl ether of dicyclopentenol. The energy required to grind the paste was about 20% less than in Example 4. The viscosity was 74 Pa.s. Furthermore, the tendency to foam of the paste diluted to the application concentration was further reduced compared to Example 4.

6. The batch contained the following liquid constituents (in% by weight):
22% oleyl alcohol-cetyl alcohol (1: 1) + 1.5 PO + 6 EO
6% polyethylene glycol 400

The composition of the solids, including Na-dodecylbenzenesulfonate, corresponded to the information in Example 4. The paste, ground to an average grain size of 18.2 μm and having a viscosity of 82 Pa.s, was stable on storage and easy to convey. Their tendency to foam at application concentration was minimal. In addition, the detergent was characterized by improved rinsability in the rinse phase.

Claims (10)

1. Method for dosing detergents, characterized by the use A) a pasty, structurally viscous, phosphate-reduced to phosphate-free detergent which is essentially free of water, organic solvents and hydrotropic compounds, consisting of a phase which is liquid in the temperature range below 10 ° C. and which is formed from nonionic surfactants from the class of the polyglycol ether compound, and a solid, particulate phase dispersed therein, which is formed from washing alkalis, sequestering compounds and other detergent constituents and, if appropriate, anionic surfactants B) a pressure-resistant container for the paste-like detergent, consisting of a hollow cylinder which is closed on one side with a plate which can be displaced in the direction of the cylinder axis within the container and on its opposite side has an outlet opening and a releasable connecting element with which the container connects to the device ( C) can be connected C) a metering device controlled as a function of the amount of water fed in or the concentration of the wash liquor, consisting of a pressure stamp acting on the displaceable closure plate of the container and an outlet nozzle for the paste-like agent connected to the outlet opening of the container via the releasable connecting element, the outlet nozzle, which can be provided with a controllable shut-off, is arranged within the dispenser of the washing machine so that its mouth in the area of the spray jet or an increased turbulence of the water fed in. 2. The method according to claim 1, characterized in that the pasty detergent (A) contains 15 to 36, preferably 18 to 30 and in particular 20 to 25 wt .-% of low-melting mixtures of nonionic surfactants. 3. Process according to claims 1 and 2, characterized in that the paste-like agent up to 4 wt .-%, preferably 0.5 to 2.5 wt .-% of a sulfonate surfactant from the class of C₁₀₋₁₃ alkylbenzenesulfonates , C₁₁₋₁₅ alkane sulfonates, C₁₂₋₁₈ alpha olefin sulfonates, alpha sulfo fatty acids and their esters and up to 1% by weight, preferably up to 0.5% by weight of a C₁₂₋₁₈ soap. 4. The method according to one or more of claims 1 to 3, characterized in that the agent contains sodium metasilicate in proportions of 35 to 70 wt .-%, preferably from 40 to 65 wt .-%. 5. The method according to one or more of claims 1 to 4, characterized in that the average grain size of the dispersed particulate phase is between 5 and 40 microns, with at most 10% of the particles having a grain size of more than 80 microns. 6. The method according to claims 1 to 5, characterized in that the Brookfield (6/10 at 20 ° C) measured viscosity of the paste-like agent is 20 to 1000 Pa.s, preferably from 30 to 300 Pa.s. 7. The method according to one or more of claims 1 to 6, characterized in that within the container (B) Slidable plate is designed as a flat piston and that the connecting element attached in the region of the outlet opening of the container consists of a screw thread or a bayonet catch or a groove or a circumferential ring. 8. The method according to claim 7, characterized in that the outlet opening is designed like a tube head and the displaceable plate is provided on the inside with a cylindrical or conical projection which protrudes into the outlet port of the tube opening in the most advanced position of the plate. 9. The method according to any one of claims 1 to 8, characterized in that the pressure stamp of the metering device (C) exerts constant pressure on the movable plate of the container (B) and the dosage of the paste in the induction bowl of the washing machine by means of an adjustable Shutting-off device takes place, which is arranged between the connecting element and the outlet nozzle of the metering device. 10. The method according to claim 9, characterized in that the control of the shut-off device takes place as a function of the electrical conductivity of the wash liquor.