NO176919B - Method of Dosing Pasta Detergent - Google Patents

Description

The present invention relates to a method for dosing detergents. The method is particularly suitable for implementation in professional laundries and "is based on the new development of a pasty detergent, which is fed into the washing process using a special dosing system adapted to this agent.

Liquid to pasty detergents are known in large numbers. These are generally tailored to the needs of the household, i.e. they must be sufficiently liquid to be poured out and dosed without problems. As they must also be storage-stable within a larger temperature range, the use of organic solvents and/or hydrotropic additives cannot usually be avoided. However, these additives are washing-inactive, relatively cumbersome and require extra packaging volume or transport and storage capacity. In particular, a content of volatile flammable solvents which additionally require safety precautions is disturbing. Detergent concentrates of the aforementioned type are therefore not, or only slightly, suitable for laundries.

Pasty, essentially water-free detergents are also known, e.g. from US 4,115,308 and US 3,850,831. These also usually contain detergent-inactive liquid additives, such as polyglycols or triethanolamine, due to the dispersion of the finely divided building salts and the setting of the viscosity, so that they can be squeezed out of a tube under pressure exerted by hand without any problem. In this form, they are unsuitable for use in washing machines which are equipped with normal flushing chambers. If you dose the paste into these chambers, it will not be dissolved and dispersed by the added water, but instead a surface gel layer is formed around the paste which prevents the further dissolution process. This gel-like paste slides together with the trailing water into the washing drum, where, due to its high specific gravity, it almost completely collects in the area of the outlet nozzle and remains there practically until the end of the washing process in an unchanged state. With the after-rinse water, the agent then essentially reaches the pipe system unused.

A further disadvantage which has so far prevented the use of pasty detergents in professional laundries is packaging and dosing problems. Tubes are unsuitable for this purpose of application, as they are only suitable for limited filling quantities and their handling requires personnel and is time-consuming. For the most part, large amounts of residue remain on the tube walls and in the tube head. Removing tough pastes from ordinary storage containers by means of dosing spoons is also laborious and labor-intensive and also leads to the above-mentioned flushing problems.

Laundry companies therefore mainly use powdered detergents. As the exact dosage of such agents is problematic or personnel-intensive, especially in large companies with a high degree of automation, the agent is mostly stored and dosed in pre-dissolved form as stock washing liquid, i.e. an aqueous concentrate is used, which is then taken to the individual user sites. However, the detergent usually used in laundries contains a relatively high proportion of washing alkalis, which are only limitedly soluble in cold water and also lead to salting-out effects. They cause a phase separation with the result that the organic components, especially the non-ionic surfactants and soaps, separate and foam up. One must therefore work with a relatively strong aqueous dilution and the stock liquids must also be constantly thoroughly mixed and circulated, in order to also prevent separation of the individual components in the supply lines to the points of consumption. Such methods consequently require high investments for voluminous mixing containers and the associated static parts as well as for mixers and transport devices, as well as a constant supply of energy for tempering and re-pumping of the stock liquid.

Consequently, there is a significant need for detergent compositions and matching dosing devices with which the above-mentioned problems can be avoided and which meet the following requirements:

high washing power

that you can dispense with detergent-inactive additives such as

serves for conditioning the detergent

little need for packaging, transport and storage volume problem-free workability even at lower temperatures

respectively of chilled pastas

simple connection of the dosing system while avoiding

residual loss and residues in the packaging

dosing system that can be installed in a simple and space-saving way

suitability of the system for a process-dependent control of

the time of dosing and the amount of dosing

wide variability with regard to the choice of detergent sub-quantity and detergent concentration

safety against disturbances during gelation and deposition i

the washing container

low energy demand.

With the present invention, these problems are solved.

The object of the invention is a method for dosing detergents, characterized by

A) preparation of a pasty, pseudoplastic, phosphate-reduced to phosphate-free detergent, which contains less than 2 wt-# of water, preferably less than 1 wt-%, most preferably less than 0.5 wt-# of water, and does not contain organic solvents and hydrotropic compounds, consisting of a liquid phase and a finely divided solid phase, wherein the liquid phase consists essentially of 15 to 35 weight-#, based on the weight of the composition, of a nonionic surfactant having a melting point below 10°C, where the solid phase consists essentially of washing alkaline compounds and compounds with a sequestering effect which is homogeneous

dispersed in the liquid phase,

B) packaging of the detergent in a pressure-resistant container consisting of a hollow cylinder with an opening at each end, where one of the openings is closed with a plate displaceable in the direction of the cylinder axis inside the container and on the opposite side has an outlet opening equipped with a closure and a releasable connecting element, whereby

the container can be connected to a dosing device (C),

C) dosing the detergent with a dosing unit having an outlet nozzle connected to the outlet opening of the detergent container, said outlet nozzle projecting into the flushing chamber of the washing machine, the dosing unit having a piston designed to act under pressure on the displaceable closing plate of the detergent container to empty the detergent from there directly into the flushing area of the washing machine, whereby the detergent is dispersed and dissolved by the inflowing water to such an extent that the formation of a gel phase is avoided.

Below follows the description of the individual features of the invention.

A) Detergent

The detergent consists of a paste that is essentially free of water and organic solvents. Under "essentially free of water" is understood a condition whereby the content of liquid, i.e. water not present in the form of hydrate water and constitutional water, is below 2 wt-#, preferably below 1 wt-# and especially below 0.5 wt-# . Higher water content is unfortunate, as this increases the viscosity of the agent more than proportionally and reduces stability. Organic solvents, to which the low-molecular and lower-boiling alcohols and ether alcohols usually used in liquid concentrates belong, as well as hydrotropic compounds, are also absent, apart from traces that may be introduced with the individual active ingredients.

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

The liquid phase essentially consists of non-ionic surfactants or surfactant mixtures that melt at temperatures below 10°C. Appropriately, surfactants are used respectively their mixtures, whose "sticking point" (solidification point) is below 5°C, in order to avoid consolidation of the paste at low transport and storage temperatures. Examples of such surfactants are e.g. alkoxylated alcohols, which can be linear or methyl-branched in the 2-position (oxo alcohols), and which have 9 to 16 carbon atoms and 2 to 10 ethylene glycol ether groups (EO). Alkoxylates, which exhibit both EO groups and also polyglycol ether groups (PO), are also suitable because of their low solidification point. Examples of suitable nonionic surfactants are: Cg.n-oxoalcohol with 2 to 10 EO, such as Cg_n + 3 EO, Cg_n + 5 EO, Ct)- ii + 7 EO, Cg_1;t + 9E0;

Cn.i^-oxoalcohol with 2 to 8 EO, as <C>11_13 + 2 EO, Cn_i3 + 5 EO, C11_13 + 6 EO, C11_13 + 7 EO;

c12-15"°^soa-lkoho1 +3-6 EO, as 0^2-15 + 3 EO, C^-lS <+><5>

EO;

isotridecanol with 3 to 8 EO;

linear fatty alcohols with 10 to 14 C atoms and 2.5 to 5 EO; linear or branched Cg_14 alcohols with 3 to 8 EO and 1 to 3 PO, such as Cg.-Q-oxoalcohol + (E0)4 (P0)1_2 (E0)4 or-C11_13-oxoalcohol + (E0)3_10 (PO^.s with randomly distributed alkyl groups;

linear saturated and unsaturated C-j^^g-fatty alcohols or C9-15_ oxoalcohols with 1 to 3 PO and 4 to 8 EO, such as C^2-18" coconut alcohol + (PO)^_2(E0)4_7, oleyl alcohol respectively l: l-mixture cetyl-oleyl alcohol + (PO )1_2(E0 )5_7, C^.-j^-oxoalcohol +

(P0)1_2(E0)4_6.

Also ethoxylated alcohols whose terminal hydroxyl groups are alkylated with lower alkyl groups are suitable due to their low solidification point within the scope of the invention, for example a C^Q_^4 alcohol with 3 to 10 EO groups and a terminal methoxyl group. Further suitable nonionic surfactants are E0-P0-E0 block polymers with a correspondingly low pour point and ethoxylated alkylphenols, such as nonylphenol with 7 to 10 EO. The latter surfactants may, however, be excluded from use in certain areas due to their reduced biological degradability. They are therefore less preferred.

The content of the pastes of the aforementioned non-ionic surfactants must be so measured that on the one hand under the influence of shear forces they are still sufficiently flowable and pumpable, on the other hand in a state of rest they are so rigid or viscous so that no separation occurs during longer standing times either. Pastes with a content of 15 to 35 weight-*, preferably 18 to 30 weight-*, and especially 20 to 25 weight-* of liquid non-ionic surfactants with a low solidification point (below 5°C) are suitable. If surfactants with a higher solidification point are used, for example such at 5 to 20°C in a mixture with particularly low-melting surfactants, the content is somewhat higher, for example in the range of 18 weight-*, preferably 22 to 24 weight-*, whereby the highest content can be at 35 wt-*, preferably at 30 wt-*.

In some cases, a single non-ionic surfactant can already meet the desired requirements with regard to low solidification point, favorable flow behavior, high washing power and low foam development. An example of this is oleyl alcohol or mixtures rich in oleyl alcohol, which are first reacted with 1 to 2 PO and then with 5 to 7 EO. However, particularly favorable properties are often achieved with mixtures of non-ionic surfactants with different degrees of ethoxylation and possibly different C chain lengths. Mixtures of non-ionic surfactants with a low degree of ethoxylation and a low solidification point, for example Cg_15 alcohols with 2 to 7 EO, and those with a high degree of ethoxylation and a high solidification point, for example C-j^is alcohols with 5 to 7 EO, are consequently particularly preferred. The mixing ratio between the two alcohol ethoxylates therefore depends both on the washing technical requirements and also on 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 Cg_H-oxoalcohol + 2.5 EO and 1 part by weight Cn.^-oxoalcohol + 7 EO respectively. a mixture of 3 parts by weight of a Cn_^4-oxoalcohol + 3 EO and 2 parts by weight of a Cg_^3-oxoalcohol + 8 EO as well as a mixture of 7 parts by weight of a Ci3-oxoalcohol + 3 EO and 1 part by weight of the same alcohol + 6 EO .

Finally, the flow properties of the pastes can also be modified by adding low molecular weight polyethylene glycols (eg 200 to 800). The additive can, for example, amount to up to 15 weight-*. However, the contribution of these additives, which are often also attributed to the non-ionic surfactants, to the washing power is relatively small. However, they can act as foam suppressors and for this reason are desirable. Preferably, their proportion is up to 10% by weight, especially 0.5 to 8% by weight.

The polyglycols can also be completely or partially replaced with paraffin oils or liquid paraffin mixtures, which admittedly do not contribute to the washing power, but which facilitate the workability of the paste, especially during the grinding of the ingredients and cause a significant foam reduction, which is especially advantageously noted in the post-rinse cycle. Appropriately, the proportion of such paraffin oils respectively paraffin oil mixtures not more than 8 weight-*, preferably not more than 6 weight-*. Furthermore, liquid, long-chain ethers can also be used for the same purpose in the same quantity. Examples of this are C 6 -alkyl ethers of dicyclopentenol.

The detergent contains a solid phase, which is homogeneously dispersed in the liquid phase and which contains the other detergent ingredients with a cleaning effect as well as any auxiliary substances. These other detergent ingredients with a cleansing effect primarily include washing alkalis and compounds with a sequestering effect. Furthermore, anionic surfactants, especially those from the class of sulfonate surfactants and soaps, may be present.

Preferred washing alkali is sodium metasilicate with the composition Na£0 : SiO 2 = 1:0.8 - 1:1.3, preferably 1:1, which is used in anhydrous form. Next to the metasilicate, anhydrous soda is also suitable, which, however, due to the absorption processes, requires larger proportions of liquid phase and is consequently less preferred. The proportion of the agent of metasilicate can amount to 35 to 70 weight-*, preferably 40 to 65 weight-* and especially 45 to 55 weight-* and of soda from 0 to 20 weight-*, preferably 0 to 10 weight-*.

Suitable sequestering agents are those from the class of aminopolycarboxylic acids and polyphosphonic acids. The aminopolycarboxylic acids include nitrilotriacetic acids, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid and their higher homologues. Suitable polyphosphonic acids are 1-hydroxyethane-1,1-diphosphonic acid, aminotri-(methylenephosphonic acid), ethylenediamine-tetra-(methylenephosphonic acid) and their higher homologues, such as e.g. diethylenetriaminetetra-(methylenephosphonic acid). The above-mentioned polycarboxylic acids or The polyphosphonic acids are usually used in the form of 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 further polycarboxylic acids or hydroxypolycarboxylic acids in the form of alkali metal salts, for example sodium citrate and sodium gluconate.

The preferably used sequestering agents include homopolymeric and/or copolymeric carboxylic acids or their sodium or potassium salts, 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, further with vinyl esters, such as vinyl acetate or vinyl propionate, acrylamide, methacrylamide and with ethylene, propylene or styrene. In such copolymeric acids, in which one of the components does not exhibit any acid function, their proportion in order to achieve a sufficient water solubility amounts to no more than 70 mol-*, preferably less than 60 mol-*. As particularly suitable, copolymers of acrylic acid or Methacrylic acid with maleic acid proved to be, as for example characterized in EP 25 551-B 1. These are copolymers containing 50 to 90 weight* of acrylic acid or methacrylic acid and 50 to 10 weight-* maleic acid. Particular preference is given to such copolymers in which there are 60 to 85% by weight of acrylic acid and 40 to 15% by weight of maleic acid.

Also useful are polyacetal carboxylic acids, which are described, for example, in US patents 4,144,226 and 4,146,495 and which are obtained by polymerization of esters of glycolic acid, introduction of stable terminal end groups and saponification into the sodium or potassium salts. Also suitable are polymeric acids obtained by polymerization of acrolein and disproportionation of the polymer according to Canizzaro by means of strong alkali compounds. They are essentially made up of acrylic acid units and vinyl alcohol units, respectively. acrolein units.

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

The agent's proportion of polyacids containing carboxyl groups or polymeric acids make up 0 to 10 wt-*, preferably 1 to 7.5 wt-* and especially 2 to 5 wt-*, of polyphosphonic acids 0 to 3 wt-*, preferably 0.05 to 1.5 wt-* and especially 0 .1 to 1 weight-*. They are used in anhydrous form.

The washing pastes are preferably phosphate-free. Provided that a phosphate content is ecologically acceptable (e.g. in waste water treatment that eliminates phosphates), polymeric phosphates may also be present, such as sodium tripolyphosphate (STP). Their share can amount to up to 20% by weight, based on the agent, whereby the share of the other solids, e.g. of the sodium silicate, is reduced accordingly. Preferably, the proportion of STP amounts to no more than 15 weight-* and in particular no more than 10 weight-*.

As sequestering agent in connection with the present invention is further understood to be finely divided zeolites of type NaA, which exhibit a calcium binding capacity in the range from 100 to 200 mg Ca0/g (according to the specifications in DE 24 12 837). The particle size is usually in the range of 1-10 µm. They are used in dry form. The water contained in the zeolite in bound form does not interfere in the present case. The content of zeolites amounts to 0 to 20 weight-*, preferably 0 to 10 weight-*.

As additional additives with a cleansing effect that can be incorporated in a solid, finely divided, essentially anhydrous form in the detergent, anionic surfactants are mentioned. Particularly suitable are sulphonates and fatty acid soaps, which are preferably present as sodium salts. Alkylbenzenesulfonates with linear C 1-4 alkyl chains, especially dodecylbenzenesulfonate, linear alkanesulfonates with 11 to 15 C atoms, which can be obtained by sulfochlorination or sulfoxidation of alkanes and subsequent saponification or neutralization, alphasulfofatty acid salts as well as their esters, which are derived from saturated Ci2-ig fatty acids °§ lower alcohols, such as methanol, ethanol and propanol, and olefin sulfonates, such as e.g. formed by SC^-sulfonation of terminal Ci2-18" olefins and subsequent alkaline hydrolysis. Preferred surfactants are alkylbenzene sulphonates. As soaps, those of saturated and/or unsaturated Ci2-18~ fatty acids come into question, for example from coconut, palm kernel or tallow fatty acids derived soaps. In view of a low foaming rate when using the agent, the proportion of sulfonate surfactants should not exceed 4 wt-*, calculated on the basis of the agent. Preferably, it amounts to 0.5 to 2.5 wt-* of sodium dodecylbenzene sulfonate. An additive of sulfonate surfactant not only increases the washing power, but also improves the stability of the paste against sedimentation phenomena and facilitates the dispersion of the paste in water. Surprisingly, it has been found that the sulfonate surfactant essentially distributes in the liquid phase and improves the solid/liquid balance to promote the liquid phase. Pastes containing sulfonate surfactants can consequently absorb larger amounts of solids, or the proportion of non-ionic surfactant can reduce are seen accordingly without appreciable vis-kos in close search.

An addition of soap, which can amount to up to 1 weight-*, preferably up to 0.5 weight-* and especially 0.1 to 0.3 weight-* on the basis of the agent, also increases the suspension stability of the paste. Furthermore, such an additive reduces the foaming tendency and improves the washing power of the agent. Higher proportions than 1 to 2 weight-* can consolidate the paste and must therefore be avoided.

As additional components, which must also predominantly be assigned to the solid phases, detergents come into question. These include graying inhibitors, optical brighteners, foam inhibitors, bleaching agents and dyes. As long as fragrance substances, which are generally liquid, are used, these change into the liquid phase. Due to their low amounts, however, they have no appreciable effect on the flow behavior of the paste.

Suitable anti-greying agents are cellulose ethers, such as carboxymethyl cellulose, methyl cellulose, hydroxyalkyl cellulose and mixed ethers, such as methyl hydroxyethyl cellulose, methyl hydroxypropyl cellulose and methyl carboxymethyl cellulose. Preferably, Na-carboxymethyl cellulose and their mixtures with methyl cellulose are used. The proportion of graying inhibitors generally amounts to 0.2 to 2 weight-*, preferably 0.5 to 1.5 weight-*.

As optical brighteners for textiles made of cellulose fibers (cotton), derivatives of diaminostilbenisulfonic acid or their alkali metal salts present. Suitable are e.g. salts of 4,4'-bis(2-anilino-4-morpholino-1,3,5-triazin-6-yl-amino)-stilbene-2,2'-disulfonic acid or similarly structured compounds, which instead of the morpholino group can carry a diethanolamino group, a methylamino group or a 2-methoxyethylamino group. Furthermore, brighteners of the substituted 4,4'-distyryl-diphenyl type may be present; e.g. the compound 4,4'-bis-(4-chloro-3-sulfostyryl)-diphenyl. Mixtures of lighteners can also be used. Lighteners of the type 1,3-diaryl-2-pyrazolines are suitable for polyamide fibers, for example the compound 1-(p-sulfamoylphenyl)-3-(p-chlorophenyl)-2-pyrazoline and similarly structured compounds. The content of the agent of optical brighteners or brightener mixtures generally amount to 0.01 to 1 weight-*, preferably 0.05 to 0.5 weight-*.

Known polysiloxane-silicic acid mixtures are suitable as foam inhibitors, whereby the finely divided silicic acid contained therein is preferably silanized. The polysiloxanes can consist of linear compounds as well as cross-linked polysiloxane resins as well as their mixtures. Further suitable defoamers are paraffin hydrocarbons, including the already mentioned paraffin oils, also microparaffins and paraffin waxes, whose melting point is above 40°C. Useful defoamers are further saturated fatty acids or soaps with 18 to 24, preferably 20 to 22 C atoms, e.g. sodium behenate. The proportion of the additional, i.e. in addition to the paraffin oil, foam inhibitors present can be up to 2 weight-*, preferably up to 1 weight-*, in the case of soaps correspondingly less. In many cases, however, the tendency to foam can be prevented by a suitable choice of non-ionic surfactants, so that the use of defoamers can be dispensed with.

Bleach may be present as an additional component in the solid phase. Useful are per compounds, such as sodium perborate monohydrate, caroate (KHSO5) and organic peracids, such as perbenzoate or peroxyphthalate. These percompounds are storage stable in the agents used in the invention due to the extensive absence of water. Optionally, known bleach activators may also be present, which hydrolyze upon the addition of water with the per compounds to form per acids, for example tetraacetylene tetramine or phthalic anhydride. As the bleaching components in commercial laundries are often added to the washing lye separately and are usually only used in special cases, the content of bleaching agents in the paste can be waived in such cases.

The components present in the solid phase must be finely divided. Particularly advantageous has been found to be a particulate paste whose constituents exhibit an average grain size of 5 to 40 µm, whereby at most 10* of the particles exhibit a grain size of more than 80 µm. Preferably, the average grain size is 10 to 30 pm and especially 10 to 20 pm, whereby the maximum grain size is below 100 pm, especially below 80 pm. The average particle size relates to the volume distribution, which is determined by known methods (e.g. Coulter Counter).

The viscosity of the pastes ranges from 20 Pa.s to 1000 Pa.s (Pascal . sec.), measured at 20°C according to Brookfield 6/10 (spindle No. 6 at 10 revolutions per minute). Preferred viscosity range is 30 to 300 Pa.s, especially 50 to 150 Pa.s. The pastes are thixotropic. At room temperature, their viscosity without the application of shear forces is so high that under the influence of gravity alone they do not, or not in a time necessary for the planned use, or amount, flows out from the supply container. In this respect, they differ in principle from known anhydrous, 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 non-ionic surfactants or organic solvents are significantly higher and consequently also the viscosity or the kinematic toughness is significantly lower.

For the production of the pasty detergent, the liquid components, which are suitably heated to temperatures of 40° C to 60° C, are mixed with the solid substances already present in powder form. The premix is then ground and homogenised in a grinding device, for example a colloid mill, to the grain size specified for the solid phase, whereby excessive heating of the product is avoided by suitable cooling of the device. The homogenized paste is, if necessary, degassed in a deaeration plant under vacuum. Subsequently, thermally sensitive components as well as the components that serve for final viscosity adjustment, such as fragrances, dyes, organic compounds, layer silicates and soaps, can be added. The finished pasta can be immediately filled into packaging containers.

B) Detergent container

The detergent container is cylindrical in shape and has an opening on each of the two sides. One of the two openings is closed with a plate arranged inside the container, which is displaceable in the direction of the container axis. The displaceable plate must seal the container wall to such an extent that an escape of the paste in this area is prevented, i.e. the displacement of the plate takes place appropriately with light friction against the container wall. The plate can be flat or slightly concave. In order to prevent the movable plate from tipping or standing on edge, the edge is appropriately bent outward in a collar-like manner, i.e. the plate is designed as a flat flask. Such a well-adapted design improves the sealing at the same time. In this embodiment, the displaceable plate can simultaneously serve as a container closure during shipping and storage of the container filled with pasta. In addition, it can be secured with a removable or high-pressure yielding foil or a shell break point.

The container opening located opposite the displaceable plate can comprise the entire cross-section of the container or be reduced compared to this cross-section. In the first case, the opening is designed as for an open cartridge, in the second case, for example, as a tube head. The container opening carries, preferably on the outside, a detachable connecting element, with which it can be attached or is connected to the dosing device. This connecting element can, for example, consist of a screw thread (external thread), a bayonet closure, a seam or a circumferential ring. During shipping and storage of the filled container, the outlet opening is equipped with a closure, which suitably engages the connecting element and can for example consist of a screw cap or a closure cap with a bayonet ring. For this purpose, however, you can also use an elastic removable cover or a peelable foil.

If the closure is designed as a tube head, i.e. with a bevelled outlet opening, the inner surface, which points in the direction of the displaceable plate, must be designed so that in the emptied state, if possible, nothing or only minimal amounts of paste are left behind. Corresponding to the shape of the displaceable plate, the tube head can therefore be flat or curved on the inside. Furthermore, the displaceable plate on the inner side can carry a cylindrical or conical nozzle, which in the furthest forward position protrudes into the outlet of the tube head and also ejects the paste residues contained therein. This nozzle can be designed to be hollow in the outward direction. The resulting outlet can also serve to fix the press piston during the dosing process.

The container is made of a corrosion-resistant material, i.e. not attacked by the washing paste or an aqueous detergent solution, such as plastic, metal or glass. At the used pressing pressures, which lie in the range from 1 to 10 kg/cm<2>, mostly 1 to 5 kg/cm<2>, it must, in order to achieve a sufficiently precise fit, remain essentially dimensionally stable. The size of the container in itself is not critical, however, it should appropriately accommodate contents for several hours of operation, in order to minimize the packaging and handling work. The holding capacity should therefore be at least 0.2 liters and no more than 20 liters, preferably 0.5 to 10 liters. Larger barrels are relatively unmanageable and cumbersome to manufacture.

C) Dosing device

The dosing device essentially consists of the following elements: a detachable connecting element for the detergent container,

with which this can be connected to the dosing device,

an outlet nozzle, which leads into the flushing chamber of the washing machine and whose mouth is located in the area of the flushing jet or an area of elevated turbulence for it

introduced the water,

a press piston, which acts on the displaceable plate

of the detergent container,

optionally one in the area of the outlet nozzle arranged

shut-off device for the washing paste,

a control device, which, depending on the water supply or the detergent concentration in the washing liquor, controls the progress of the press piston via the opening time of the shut-off device in the area of the outlet nozzle.

The connecting element is designed so that it enables a firm and sufficiently sealed connection with the connected pasta container against the pasta outlet. In this connection, screw connections and bayonet closures have proven to be appropriate. With a sufficiently accurate fit, additional sealing elements or sealing rings. Also pressing rings or annular coupling elements, which engage a correspondingly designed fold or a circumferential ring or a cornice at the outlet of the pasta container and which are operated automatically, for example pneumatically or hydraulically, can be advantageously used.

The dosing device has a pressure piston, which acts on the displaceable plate of the pasta container and drives it forward when removing the pasta. The drive can take place pneumatically, hydraulically or mechanically, for example by means of racks, threaded spindles or by means of eccentrics. If there are no additional shut-off devices in the outlet nozzle, the progress is controlled, and thus the exact dosing of the paste is ensured. Preferably, however, a device is chosen whereby the press piston constantly exerts a certain pressure on the displaceable plate, and the removal and dosing of the paste takes place with the aid of a process-controlled shut-off device, which is arranged in the area between the connecting element and the outlet nozzle. In the simplest case, the press piston is operated hydraulically using the pressure from the water line. At the same time, such a device is particularly susceptible to disturbances in the event of varying or non-existent water pressure, as a change in the water pressure and thus the amount of flushing is simultaneously compensated for by a corresponding change in the paste pressure and the resulting amount of paste released.

The outlet nozzle must lead the pasta into the flushing chamber in an area where the water exerts the strongest possible shearing forces on the pasta. This achieves that the paste is distributed in small particles that are quickly distributed and dissolved. The formation of a critical gel state is thereby effectively avoided.

Such an undesirable gel state often forms when water without increased shear acts on a paste of the specified composition. The non-ionic surfactants then swell to a tough, gel-like mass, which prevents the access of further water. The formed pieces of slime do not dissolve with sufficient speed in the downstream water and, due to the relatively high specific weight, slide very quickly to the lower areas of the washing container or the outlet of the washing machine, where they remain until the washing liquid is pumped out and are thus lost to the washing process.

With the aforementioned arrangement of the outlet nozzle and the indicated working rate, these disadvantages are completely avoided. Using conductivity measurements, it can be demonstrated that the distribution and dissolution process only takes seconds. This is a prerequisite for the control of the dosing process to also take place using the conductivity of the washing liquid. This is particularly an advantage when the water pressure is exposed to strong fluctuations or when the washing lye concentration is to be adapted individually and automatically to the degree of soiling of the wash and thus also the dirt load for the washing liquid. A control depending on the degree of soiling of the sink enables a particularly rational use of the detergent and results in a smaller waste water load.

At the mouth, the outlet nozzle is preferably chamfered and has an inner diameter of 0.5 to 10 mm, preferably of 1 to 6 mm.

In the area between the connecting element and the mouth of the outlet nozzle, a shut-off device can be installed in a suitable place, for example a shut-off valve or a valve. The opening and closing of the shut-off device can take place pneumatically, hydraulically or with the help of a regulating motor. Such a shut-off device is mandatory when the pressure piston, as described above, is under a constant pressure and is not moved in a controlled manner. With this preferred device, the opening and closing of the shut-off device takes place in a process-controlled manner, and more precisely in dependence on the introduced amount of water or, particularly preferred, in dependence on the conductivity of the washing liquid. The latter method enables a particularly exact adaptation to the dirt load for the washing liquid and possibly a subsequent dosing of washing paste.

Controlling the dosing process is relatively uncomplicated. In the simplest case, it can take place with the aid of the automatic flush installed in the washing machine anyway. It has proven appropriate to control the water supply and the addition of pasta in such a way that at the beginning a small portion of the total water supplied is first placed, then the pasta is introduced in the specified manner and then it is flushed after for some time. With a dosage based on conductivity, due to the slightly delayed dissolution process, it is appropriate to end the addition of the paste at an earlier time. The final washing liquor concentration and the corresponding conductivity of the washing liquid then settles in a few seconds, a maximum of 30 seconds later. But even with a simple time connection, good results can be achieved, adapted to the current requirements.

The emptied container can be refilled repeatedly and reused or, with correspondingly low material consumption, also thrown away as disposable packaging.

The concentration of the washing liquid is in the range from 0.5 to 10 g/litre. It depends on the degree of soiling of the washing, i.e. for less soiled washing, the application concentration is generally 0.5 to 5 g/litre, for heavily soiled washing at 5 to 10 g/litre. In special cases, e.g. with heavily soiled work clothing, the concentration can be even higher and for example amount to 12 g/litre. Generally, it amounts to 2 to 8 g/litre. The mixing ratio (kg of textile pulp to liter of washing mixture) is generally 1:2 to 1:10, preferably 1:4 to 1:6. Normally, softened (permuted) water is used, whereby softened water is also used for the subsequent rinse, at least for the first rinse. In principle, the washing process in the machine does not differ significantly from the usual way of working, with the exception of

(as indicated above) that automatic re-dosing of the detergent can take place in case of increased demand due to heavy soiling.

The method according to the invention can be carried out using the device shown in Figure I. The paste-like detergent is in the container (3). This is pressed by means of a pressure piston (2), which acts on the displaceable closing plate (9), by means of a detachable connection element with controllable shut-off (4) over an outlet nozzle (7) located in the area of the water inlet (6) , into the flushing chamber (5) of the washing machine. Via the outlet (8) from the flushing chamber (5), the pasty agent reaches the washing machine. The pressure piston (2) can, in the same way as the shut-off (4), be regulated by means of a control device (1), depending on the amount of water introduced or the concentration of the washing solution. The pressure piston (2) and the controllable shut-off (4) together make up the dosing device (C).

Examples

1. The detergent mixture (200 kg) contained the following anhydrous ingredients (by weight*):

24.0 * non-ionic 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

As non-ionic surfactant, a mixture of saturated <C>12-14" fatty alcohol + 3 EO and Ci2_i4 fatty alcohol + 5 EO in a weight ratio of 1:1 with a solidification point of 5°C was used.

The mixture was ground in a grinding device (colloid mill type "SZEGO-1") for 30 minutes. The ground product (outlet temperature 45°C) had an average grain size of 18.6 µm and a viscosity of 50 Pa.s (according to Brookfield 6/10 at 20°C). In a cooled paste mixing container with a wall scraper, 0.1* of a dye was added. The final product was a storage-stable, pumpable paste with a specific gravity of 1.7 g/ml. A washing liquid produced in this way was slightly foaming and had a high washing power.

The paste was filled into 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 litres. The movable, planar base plate had a circumferential, collar-shaped rim with a height of 12 mm (measured from the planar surface). On the open opposite side of the cartridge, bayonet-shaped connecting elements were placed on the outer edge, with which the cartridge could be attached below to the nozzle end and the dosing device. The sealing between the nozzle tip and the cartridge took place with the help of an elastic sealing ring. The mouthpiece spigot opened into a connecting pipe, in which a rotatable shut-off tap was placed. 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 immediately at the open edge of the injected water jet, so that the exiting paste was entrained and dispersed by it. The shut-off tap was connected to an electrically driven regulating motor, whose function was regulated by an automatic control device via a conductivity sensor arranged in the washing drum. The regulation took place in such a way that first approx. 10* of the total required water was introduced without pasta addition. This water served at the same time to remove crust formations that form during longer stock times under the influence of moisture on the nozzle mouth. Then followed the addition of the paste until the pre-programmed conductivity value was achieved, followed by a further addition of water until the required liquid!wet was achieved.

The necessary pressing pressure on the movable base plate took place with the help of a hydraulically operated pressure piston. The pressure corresponded to the line pressure for the drinking water and amounted to 1.5 kg/cm<2.> The washing system was then switched off during longer rest periods. 2. Example 1 was repeated using 57 wt-* of metasilicate and 22 wt-* of a non-ionic surfactant mixture of 2 parts by weight of C 2 -oxo alcohol with 5 EO and 1 part by weight of <C>i 2 -i 3 -oxo alcohol met* 6 EO. The average grain size of the grinding material was 16.5 pm, the viscosity 54 Pa.s (Brookfield 16/20 at 20°C). This mixture was also storage-stable, pumpable and doseable and, diluted with water, gave slightly foaming solutions with comparable properties. 3. Example 1 was repeated, whereby 0.2 wt-* of the nonionic surfactant was replaced by the same amount of a sodium tallow soap. The viscosity of the paste increased to 68 Pa.s. The aqueous washing liquids showed a particularly low tendency to foam. 4. A paste was produced with the following composition (in weight*):

17.5 * <C>13-oxo alcohol + 3 EO

2.5 * C13 oxoalcohol + 6 EO

2.0 * Na-dodecylbenzenesulfonate

8.0 * polyethylene glycol (MG 400)

7.5 * acrylic acid-maleic acid 3:1 copolymer (MG 70,000),

present as sodium salt

2.5 * ethylenediaminetetra-(methylenephosphonate), Na^-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 took place analogously to the procedure indicated in example 1. The average grain size was 17.0 pm, whereby there were no portions with a grain size above 40 pm. The viscosity was 76 Pa.s (according to Brookfield 6/10) at 20°C. With regard to usage properties, the paste corresponded to the agent according to example 1 with an even lower foaming tendency, especially during the post-rinse phase. 5. Compared to Example 4, the polyethylene glycol ether was replaced with a 1:1 mixture of paraffin oil and a lauryl ether of dicyclopentenol. Compared to example 4, the energy requirement for the grinding of the paste was approx. 20* lower. The viscosity was 74 Pa.s. Furthermore, the tendency to foam for the paste diluted to the application concentration was further reduced compared to example 4. 6. The mixture contained the following liquid components (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 pm and exhibiting a viscosity of 82 Pa.s was storage stable and well transportable. The tendency to foam at the application concentration was minimal. Furthermore, the detergent excelled in improved rinseability in the post-rinse phase.

Claims (10)

1. Method for dosing detergents, characterized by A) production of a pasty, pseudoplastic, phosphate-reduced to phosphate-free detergent, which contains less than 2 weight-* of water, preferably less than 1 weight-*, most preferably less than 0.5 weight- * water, and does not contain organic solvents and hydrotropic compounds, consisting of a liquid phase and a finely divided solid phase, where the liquid phase consists essentially of 15 to 35 weight-*, based on the weight of the composition, of a non-ionic surface-active agent which has a melting point below 10°C, where the solid phase consists essentially of washing alkaline compounds and compounds with a sequestering effect which are homogeneously dispersed in the liquid phase, B) packaging of the detergent in a pressure-resistant container (3) consisting of a hollow cylinder with an opening at each end, where one of the openings is closed with a displaceable plate (9) inside the container in the direction of the cylinder axis and on the opposite side it presents an outlet opening equipped with a closure and a detachable connecting element (4), with which the container can be connected to a dosing device (C), C) dosing of the detergent with a dosing unit that has an outlet nozzle (7) connected to the outlet opening (4) of the container (3) for detergent, where said outlet nozzle (7) projects into the flushing chamber (5) of the washing machine, where the dosing unit has a piston (2) designed to act under pressure on the displaceable closure plate (9) of the detergent container (3) in order to empty the detergent from there directly into the flushing area (5) of the washing machine, whereby the detergent is dispersed and dissolved by the inflowing water (6) to such an extent that the formation of a gel phase is avoided. 2. Method according to claim 1, characterized in that the pasty detergent (A) contains 18 to 30 and especially 20 to 25 weight-* of lower melting mixtures of non-ionic surfactants. 3- Process according to claims 1 and 2, characterized in that the paste-like agent contains up to 4 wt-*, preferably 0.5 to 2.5 wt-* of a sulfonate surfactant from the class of C10-13<->alkylbenzenesulfonates, Cn_15-alkanesulfonates, C -^.-^-alf a-olefin sulphonates, alpha-sulfofatty acids and esters thereof as well as up to 1 weight-*, preferably up to 0.5 weight-* of a C^2-18-saPe• 4. 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 weight-*, preferably of 40 to 65 weight-*. 5. Method according to one or more of claims 1 to 4, characterized in that the average grain size for the dispersed particulate phase is between 5 and 40 pm, whereby no more than 10* of the particles exhibit a grain size of more than 80 pm. 6. Method according to claims 1 to 5, characterized in that the viscosity measured according to Brookfield (6/10 at 20° C) for the pasty agent amounts to 20 to 1000 Pa.s, preferably from 30 to 300 Pa.s. 7. Method according to one or more of claims 1 to 6, characterized in that the plate that can be moved inside the container is designed as a flat flask and that the connecting element placed in the area at the outlet opening of the container consists of a screw thread or a bayonet closure or a fold or a circumferential ring. 8. Method according to claim 7, characterized in that the outlet opening is designed as a tube head and the displaceable plate on the inner side is equipped with a cylindrical or conical nozzle, which projects into the outlet spigot for the tube opening at the farthest forward position of the plate. 9. Method according to one or more of claims 1 to 8, characterized in that the pressure piston of the dosing device (C) exerts a constant pressure on the moving plate of the container and the dosing of the paste in the flushing container of the washing machine takes place with the help of an adjustable shut-off device, which is arranged between the connection element and the outlet nozzle of the dosing device. 10. Method according to claim 9, characterized in that the control of the shut-off device takes place depending on the electrical conductivity of the washing liquid.