DE2746843C2 - Process for providing liquid detergents in dishwashers - Google Patents

Description

The invention relates to a method for providing liquid cleaning agents in dishwashers.

In machine dishwashing, a pre-wash cycle is usually followed by a cleaning cycle in which alkaline cleaning agents are used. These agents are generally in solid form and consist of alkali silicates, alkali phosphates, polymeric alkali phosphates, alkali carbonates, etc. and also contain chlorine-releasing components and a mostly non-ionogenic surfactant. The products must be stable on storage and must not clump in the pack. When dispensing, dust should be avoided if possible, as this irritates the mucous membranes. The products must be easy to pour into the dispensing chamber, which requires and must be able to flow freely These ⁴ ί requirements are met with agents that are available in granular or granular form.

In general, the dishwashing machines are equipped with a metering chamber that is filled prior to rinsing with the solid cleaner and automatically opens ⁵ⁿ table at the right point tent and the contents emptied into the rinsing water. For the user of a dishwasher, this means that he has to pour the solid detergent into the dispenser chamber before each wash. This can sometimes lead to difficulties in automatic flushing ^, namely when the cleaner for. B. contains active chlorine and negen reaches the dosing chamber and falls from there when the door is closed on cutlery and causes ugly stains there. Sometimes too little is used because the consumer cannot always estimate the amount of detergent required for the dishes to be cleaned, which leads to unsatisfactory cleaning. If, for the same reason, overdosing is used, the process becomes unnecessarily more expensive and the water is excessively contaminated with ^hl detergent.

From US-PS 31 87 767 a method is known in the solid detergent mixture is placed in a storage container, from which by adding water in portions Detergent solution can be prepared. The disadvantage here is that clumping cannot be avoided and a constant composition due to the different solubility of the cleaning components the solution is not guaranteed.

Attempts have also been made to use liquid cleaners. Liquid cleaners are known based on Alkali phosphates, polymeric alkali phosphates, alkali silicates and free alkali. Since there is no dishware to dispose of stubborn stains such as tea, coffee or liquid pensiif residues must contain strongly oxidizing components, Chlorine-releasing substances such as hypochlorite or potassium chloride isocyanurate are also required in such cleaning agents. Liquid products containing active chlorine, however, have little storage capacity. The chlorine is on the one hand volatile, on the other hand it is degraded so that the cleaning performance is no longer satisfactory within a short period of time. Likewise, the polymeric phosphate is hydrolyzed, so that after some time the lime binding capacity and the known good cleaning power of the polymer phosphates are no longer available.

For better storage stability, the products must be stored in colored canisters to keep out decomposing light and at the lowest possible temperature. Nevertheless, the shelf life is limited to a maximum of V ₂ years.

These facts have led to the fact that liquid detergents are only used in commercial dishwashers, because this is where the products get from the manufacturer directly to the consumer and there relatively quickly are used. Liquid detergents could not prevail in household dishwashers, because they go through a long route of tributation and lose their effectiveness, which is good in themselves. aside from that products that continuously release chlorine cause nuisance.

In order to prevent chlorine losses, one is forced to set a higher chlorine content in liquid cleaning agents according to the decomposition. However, ever exists after the time after which the cleaner reaches the consumer, there is a risk of an excessively high chlorine concentration. For commercial use such as 3. In commercial Dishwashers are not bothered by this, as only underglaze decor or undecorated hotel china is flushed, which is not damaged.

The situation is different with household dishwashers, which are mainly loaded with onglaze decorative dishes, the highest compared to chlorine is sensitive. The colors fade and become dull very quickly if the chlorine content is higher Is as 40 mg / 1. Would such products in household dishwashers are used, according to the statistics, 3% of users received products that have a have an aggressive chlorine content and cause damage to the dishes.

State-of-the-art liquid cleaners are therefore particularly suitable for use in domestic dishwashers not suitable.

The object of the present application is to eliminate the disadvantages of liquid cleaners described.

The present invention therefore relates to a method to provide the cleaning solution in which the above The object is achieved by a solid detergent mixture consisting essentially of potassium salts In an amount sufficient for several wash cycles in or near the dishwasher Brings reservoir and in place

in water or the detergent solution freshly prepares the detergent mixture and fills it into the storage container of the dishwasher.

The storage container can be permanently installed in or near the dishwasher or it can also be exchangeable. He is designed to hold an amount sufficient for several wash cycles.

One can proceed in such a way that the solid detergent mixture is in the exchangeable storage container up to brings in a designated brand, fills up with water and inserts the container into the machine or one fills the solid detergent in the storage container that is permanently installed in or near the dishwasher and the solution the detergent is done automatically by rinsing in water before the wash program.

The easily and quickly soluble R ^ö .inigergemische can be dissolved with the required amount of water also by the housewife in any vessel and the ready-made liquid detergent are introduced into the storage vessel of the dishwasher.

The storage container is connected to a device for adding a predetermined amount to the rinsing water connected and optionally with a device for the automatic dissolution of the solid cleaner in the Equipped storage vessel.

The invention also relates to a cleaning agent mixture for Carrying out the process which, according to the invention, consists essentially of potassium salts.

Usual detergent mixtures of alkali phosphates, polymeric alkali phosphates, especially triphosphate, alkali silicates (alkali to SiO ₃ = 1: 1 to 1: 3), soluble phosphate substitutes such as phosphates, citrates, gluconates and carbonates, alkali hydroxide and chlorine-releasing substances, e.g. B. alkali salts of di- and trichloro isocyanuric acid gone. Because of their greater solubility in water, the components should essentially be present as potassium salts. Mixtures of potassium and sodium salts or lithium salts can also be used, but the kallumsajze should predominate.

The method according to the invention allows product composition, dosage amount and storage amount to be matched in this way agree that an optimal detergent concentration is exactly covered over a given tent space. In particular, the necessary chlorine content adhered to within the range of application within only a small fluctuation range and thus allows a excellent cleaning with minimal use of sensitive dishes.

example 1

37Og (18.5%) potassium tripolyphosphate, 160 g (8%) potassium silicate (K ₂ O: SiO ₂ = 1: 2.2), 60 g (3%) KOH and 24 g (1.2%) potassium chloroisocyanurate are with 1386 g (69.3%) of water made up to 2 kg (100%) in the storage container of a Geschlrrspülmaschlnp. The dosage for dishwashing is 5 g / l water.

Chlorine content as a function of time:
Storage at 20 ° C

Chlorine content Chlorine content of of the liquid Cleaning solution Cleaner 5 g more liquid Cleaner / l freshly made 0.72% 36 mg Detergent solution after 20 days 0.60% 30 mg after 30 days 0.40% 20 mg after 60 days 0.18% 9 mg after 90 days 0.10% 5 mg Breakdown of triphosphate 10% after 90 days

Example 1 makes it clear that the active chlorine content in liquid cleaners is high depending on the tent decreases. It is advisable to adjust the active chlorine content in the detergents, depending on the dosage, so that the detergent solution contains 20 to 40 mg of chlorine per liter. If less tJs are about 20 mg There is chlorine per 1 in the lye, so tea stains, coffee and lipstick residues cannot can be removed completely.

From Example 1 it can be seen that a sufficient amount of chlorine for good cleaning for about 30 days Available. During this time, the cleaning agent must be used up, which applies according to the invention, but not with a cleaner of the same composition that comes on the market in liquid form, is guaranteed, since the tent from production to consumer is much longer.

Statistical surveys in households have shown that with dishwasher owners

3% of users use a product
rtas is 1 to 2 months old,

7% 2 to 3 months
25% 3 to 6 months
40% 6 to 9 months
25% over 9 months.

Products that were less than 30 days old were not encountered.

Because of this fact, liquid cleaners have a higher level of decomposition Chlorine content adjusted. So has z. B. a commercially available cleaner has the following composition:

Example 2

15% potassium triphosphate

10% potassium silicate (K ₂ O: SlO ₂ = 1

15% sodium hypochlorite solution

with 13% active chlorine
5% potassium hydroxide

2.2)

55.0% water.

The liquid product is marketed as such.

Chlorine content as a function of time:

Chlorine content Chlorine content of of the liquid Rejnigungsluugc Cleaner 5 g more liquid Cleaner / I

freshly made 1.95% 97.5 mg

Solution:

after 20 days 1.5% 75 mg

after 30 days 1.3% 65 mg

after 40 days 1.1% 55 mg

after 60 days 0.9% 45 mg

after 90 days OJ% 35 mg

after 180 days 0.4% 20 mg

The example shows that the product ^{remains active cleaning for approx. 1} Z ₂ years due to the higher chlorine content, but must be used up within this period.

The product is unsuitable for household dishwashers because, depending on when the product reaches the consumer, there may be a risk of overdosing and thus damage to the decor of the dishes, or the cleaning power has been lost _{due to too long previous storage (longer than V 2 years).} These disadvantages do not occur in the method according to the invention, since the solid cleaning agent reaches the consumer and the latter only dissolves it by means of water in a suitable container or storage vessel of the dishwasher.

Claims (4)

Patent claims: 1. Process for the provision of cleaning agents containing active chlorine and polyphosphate In liquid> Form in dishwashers, characterized in that solid, essentially detergent mixture consisting of calcium salts in an amount sufficient for several wash cycles in an in or in the dishwasher brought in storage container and on the spot completely dissolves in water or the detergent solution freshly made from the detergent mixture and filled into the storage container of the dishwasher. 2. Device on dishwashers for providing the cleaning solution according to claim 1, characterized in that it has a storage container for one sufficient for several wash cycles Has the amount of liquid detergent mixture. 3. Device according to claim 2, characterized in that the storage container is exchangeable. 4. Device according to claim 2 and 3, characterized in that in addition a device for automatic dissolution of the solid detergent mixture is arranged in the storage container.