EP3293249B1 - Cleaner for hot beverages machines - Google Patents

Description

The invention relates to a solid formulated cleaner for hot beverage machines.

Commercial or household hot beverage machines are contaminated during operation from various sources. The water used for operation typically contains lime and other minerals that form undesirable deposits, particularly as a result of hot operation. Coffee and tea can also form undesirable stubborn residues.

Many hot beverage machines can also produce milk preparations such as milk foam and mix these with the hot drinks. On the one hand, it may then form froststone coverings, on the other hand, in particular, the milk paths of such hot beverage machines tend to colonize undesired microorganisms.

EP 2 924 101 A1 discloses a liquid, mild alkaline cleaner for dishwashers.

The invention is based on the object to provide a cleaner for hot beverage machines mentioned above, which allows a simple and universal application and is environmentally friendly and easy to use.

1. a) wenigstens einen Chelatbildner für Ca- und/oder Mg-Ionen aus gewählt aus der Gruppe bestehend aus MGDA und GLDA,
2. b) wenigstens einen Komplexbildner ausgewählt aus der Gruppe bestehend aus Gluconsäuren, Iminodisuccinat, ATMP (Amino-trismethylenphosphonsäure), DTMP (Diethylentriaminpentamethylenphosphonsäure), HEDP (1-Hydroxyethan-(1,1-diphosphonsäure), HDTMP (Hexamethylendiamin-tetra-methylenphosphonsäure), PBTC (Phosphonobutan-1,2,4-tricarbonsäure), Phosphonsäuren; und Salzen der vorgenannten Säuren,
3. c) wenigstens eine polymere Säure ausgewählt aus der Gruppe bestehend aus polymeren Acrylsäuren, Methacrylsäuren, Maleinsäuren, sulfonierte Polystyrole, Copolymeren der vorgenannten Säuren,

wobei der Reiniger tensidfrei, silikatfrei und phosphatfrei ist,
und wobei der Reiniger in 1 Gew.-%iger wässriger Lösung einen pH-Wert von 8 bis 11 aufweist.The invention achieves this object by a solid formulated cleaner for hot beverage machines, which contains:

1. a) at least one chelating agent for Ca and / or Mg ions selected from the group consisting of MGDA and GLDA,
2. b) at least one complexing agent selected from the group consisting of gluconic acids, iminodisuccinate, ATMP (aminotrismethylenephosphonic acid), DTMP (diethylenetriaminepentamethylenephosphonic acid), HEDP (1-hydroxyethane- (1,1-diphosphonic acid), HDTMP (hexamethylenediamine-tetra-methylenephosphonic acid), PBTC (phosphonobutane-1,2,4-tricarboxylic acid), phosphonic acids, and salts of the aforementioned acids,
3. c) at least one polymeric acid selected from the group consisting of polymeric acrylic acids, methacrylic acids, maleic acids, sulfonated polystyrenes, copolymers of the aforementioned acids,

wherein the cleaner is surfactant-free, silicate-free and phosphate-free,
and wherein the cleaner in 1 wt .-% aqueous solution has a pH of 8 to 11.

First, some terms used in the invention are explained.
The cleaner according to the invention is formulated as a solid. This includes in particular a formulation as a powder, granules or in compacted form such as tablet. The cleaner is intended for cleaning hot beverage machines. These are machines that use hot water (either from a storage tank or piping connection) and other ingredients to make hot drinks such as coffee, tea, cocoa or milk drinks. In particular, it can be hot beverage machines which contain so-called milk paths, in which milk is thus produced and processed as part of the hot beverage, for example in the form of milk foam.
Chelating agents can form chelate complexes via suitable ligands, in particular with Ca and / or Mg ions, and thus mask these ions. The chelating agent used in the invention according to feature a) is different from the complexing agents according to feature b). According to the invention, the chelating agents are selected from the group consisting of MGDA (methylglycinediacetic acid) and GLDA. MGDA and GLDA are also preferred because they have no toxicity. MGDA is particularly preferred.

The cleaner further contains at least one complexing agent as defined in feature b) and at least one polymeric acid as defined in feature c).

The cleaner according to the invention is surfactant-free, silicate-free and phosphate-free. This means that these substances are not added as a constituent of the formulation and are at most contained to a small extent by impurities. It preferably contains no disinfecting active ingredients selected from the group consisting of quaternary ammonium compounds, amines and active chlorine-containing compounds.

The invention provides a cleaner which is equally suitable for all areas of use in the field of hot beverage machines, in particular coffee machines. These areas of application include in particular the cleaning of the coffee paths (coffee lines and brewing unit) as well as the milk paths (milk lines, foam production, foam compression).

The combination according to the invention makes it possible, with an environmentally friendly (contains no phosphates and no surfactants), mild alkaline and not classified as hazardous cleaner Effectively clean all areas of hot beverage machines. This was not possible in the prior art.

In addition to a good cleaning performance in the field of coffee residues and milk residues and dissolution of already formed hardness deposits is achieved. This is particularly advantageous in milk foam production using hard water and counteracts the formation of deposits from the milk (milk stone). Additional descaling processes (acid rinsing) required in the prior art are not required.

The cleaner is free of surfactants and silicates and can therefore be rinsed off easily and without residue.

It preferably contains no quaternary ammonium compounds or amines or active chlorine compounds which are difficult to rinse out, cause foaming or could cause a taste impairment in the hot beverage machine.

The chelating agents according to feature a) are water hardnesses (Ca and Mg) complexers which are both lime precipitates of the water prevent as well as already formed water-insoluble compounds with calcium and magnesium can bring back into solution. Thus, mineral residues formed by milk residues as well as limestone residues precipitated by water constituents in the area of the coffee paths and production of milk foam (vapor input) can be brought into solution. In addition, these chelating agents have good iron and oil binding capacity.

Complexing agents according to feature b) also bind water hardness (thus prevent Kalkausfällungen by ingredients of the water) and additionally serve the corrosion inhibition.

The polymeric acids according to feature c) support the prevention of mineral deposits and increase the soil carrying capacity by dispersing. They also prevent calcification when using hard water and keep dirt particles in suspension. They thus enable a good cleaning performance in the area of the milk paths (keep in suspension and transport of dirt and milk particles). They improve the suspension resistance of oil and pigment soiling and thus also help to clean the coffee paths.

The cleaner according to the invention preferably has a pH of 9 to 11, more preferably 9.5 to 10 in 1 wt .-% aqueous solution. Despite this mild alkalinity, the cleaner has a high activity against lime and comparable deposits, which in the prior art can often only be removed by acid.

• Bestandteil a) 10 bis 40 Gew.-%, vorzugsweise 15 bis 25 Gew.-%;
• Bestandteil b) 10 bis 20 Gew.-%;
• Bestandteil c) 1 bis 3 Gew.-%.

Preferably, the weight proportions of components a) to c) are as follows:

• Component a) 10 to 40 wt .-%, preferably 15 to 25 wt .-%;
• Component b) 10 to 20 wt .-%;
• Component c) 1 to 3 wt .-%.

The remainder to 100% by weight are other ingredients, fillers, tableting aids mentioned below, or the like.

The molecular weight of the polymeric acid (constituent c)) is preferably 4000 to 10,000, more preferably 6000 to 8000.

According to the invention, the cleaner may additionally contain a non-polymeric acid, preferably an organic acid, more preferably citric acid and / or maleic acid. This is u.a. for better dissolution of the solid. used by reaction with fillers or tabletting excipients.

According to the invention, the cleaner may additionally contain tabletting aids if it is to be formulated in a defined form, for example in the form of a tablet.

According to the invention it is preferred that the cleaner additionally contains a per-compound, preferably a peroxo compound, more preferably a peroxosulphate.
These help to remove all oxidizable impurities such as proteins or tannins.

Particularly preferably, the content of per-compound is less than 3 wt .-%, preferably 1 to 2.9 wt .-%. A cleaner with a content of per-compound below a threshold value of 3% by weight is not required to be labeled as a hazardous substance.

In a further particularly preferred variant, the cleaner according to the invention contains no water-insoluble solids. In the prior art, insoluble abrasive solids, such as, for example, silicates or microcrystalline cellulose, are frequently used, in particular for cleaning the milk paths. These solids are very difficult to rinse out and can contribute to the clogging of pipes. The cleaner according to the invention achieves a good cleaning effect even without the addition of such solids. Thus, the cleaner according to the invention is preferably soluble in the usual application concentrations residue-free in water.

Another object of the invention is the use of a cleaner according to the invention for cleaning hot beverage machines, especially hot beverage machines for the preparation of coffee tea and / or cocoa drinks.

The cleaner can be used according to the invention for cleaning coffee paths and milk paths and for cleaning a milk foam hardening unit.

The use concentration of a cleaner according to the invention in aqueous solution is preferably 0.4 to 1.5 wt .-%, more preferably 0.6 to 1 wt .-%.

The cleaning times are preferably between 1 and 15 minutes, preferably between 5 and 8 minutes. Embodiments of the invention will be described below. The figure shows the result of cleaning experiments described below and comparative experiments.

Example 1 - Formulation example

The formulation ingredients listed in Table 1 are mixed together and pressed into tablets. The quantities in the table are parts by weight. Table 1 Na sulphate 16.2 PEG 4000 20 HEDP, 4 Well, 12 citric acid 11 Caroate (K-peroxomonosulfate) 1.3 PAS 7000 N 1.5 K-carbonate 5 MGDA 18 soda 15

Example 2 - Comparative Example

The formulation ingredients given in Table 2 are mixed together and pressed into tablets. The quantities in the table are parts by weight. It is a phosphate-containing comparison recipe. Na sulphate 4.5 PEG 4000 8th K-carbonate 11 NaTPP (Na tripolyphosphate) 45 Na percarbonate 31.5

Example 3 - Cleaning Tests

Ceramic specimens were provided with Teeanschmutzungen. In each case, 0.5% strength by weight aqueous solutions were prepared from the formulation according to the invention and the comparative formulation and heated to 65.degree. The solutions were stirred with a magnetic stirrer at 100 rpm.

The test specimens were dipped into the solutions for about two-thirds for 45 seconds and then removed again. The cleaning performance was checked visually.

Since the loading of the components to be cleaned with detergent solution in the hot beverage machine can not be ensured immediately, but a certain time buffer is required for example for the line filling, it must be ensured that the cleaning solution at the end of the cleaning cycle or at the end of the distribution still another has sufficiently good effectiveness as at the beginning of the cleaning cycle.

The cleaning experiments described were therefore carried out both with freshly prepared detergent solution as well as with aged detergent solution as a simulation. Aged cleaning solution was allowed to stand for 2, 4, and 6 minutes after application, respectively, before attempting to clean.

The results are shown in the figure. The specimens are numbered from top to bottom and cleaned as follows: specimen Aging of the solution recipe 1 0 min comparison 2 invention 3 2 min comparison 4 invention 5 4 min comparison 6 invention 7 6 min comparison 8th invention

It can be seen that the formulation according to the invention gives better cleaning results than or better than the phosphate-containing comparative formulation immediately after the preparation of the solution.

Claims (14)

1. Cleaner formulated in solid form for hot beverage machines, characterised in that it contains:

   a) at least one chelating agent for Ca and/or Mg ions selected from the group consisting of MGDA and GLDA,

   b) at least one complexing agent selected from the group consisting of gluconic acids, iminodisuccinate, ATMP (aminotrismethylenephosphonic acid), DTMP (diethylenetriamine-pentamethylenephosphonic acid), HEDP (1-hydroxyethane-1,1-diphosphonic acid), HDTMP (hexamethylenediaminetetramethylenephosphonic acid), PBTC (phosphonobutane-1,2,4-tricarboxylic acid), phosphonic acids; and salts of the aforementioned acids,

   c) at least one polymeric acid selected from the group consisting of polymeric acrylic acids, methacrylic acids, maleic acids, sulfonated polystyrenes and copolymers of the aforementioned acids,

   the cleaner being free of surfactants, silicates and phosphates,
   and the cleaner having a pH value of 8 to 11 in 1% by weight aqueous solution.
2. Cleaner according to Claim 1, characterised in that it has a pH value of 9 to 11, preferably 9.5 to 10, in 1% by weight aqueous solution.
3. Cleaner according to one of Claims 1 to 2, characterised in that the weight proportions of components a) to c) are as follows:

   - component a) 10 to 40% by weight, preferably 15 to 25% by weight;

   - component b) 10 to 20% by weight;

   - component c) 1 to 3% by weight.
4. Cleaner according to one of Claims 1 to 3, characterised in that the molar mass of the polymeric acid (component c)) is 4,000 to 10,000, preferably 6,000 to 8,000.
5. Cleaner according to one of Claims 1 to 4, characterised in that it additionally contains a non-polymeric acid, preferably an organic acid, more preferably citric acid and/or maleic acid.
6. Cleaner according to one of Claims 1 to 5, characterised in that it additionally contains a tabletting aids.
7. Cleaner according to one of Claims 1 to 6, characterised in that it additionally contains a per compound, preferably a peroxo compound, more preferably a peroxosulfate.
8. Cleaner according to Claim 7, characterised in that the content of per compound is less than 3% by weight, preferably 1 to 2.9% by weight.
9. Cleaner according to one of claims 1 to 8, characterised in that it does not contain any water-insoluble solids.
10. Cleaner according to one of Claims 1 to 9, characterised in that it does not contain any disinfecting agents selected from the group consisting of quaternary ammonium compounds, amines and compounds containing active chlorine.
11. Use of the cleaner according to one of Claims 1 to 10 for cleaning hot beverage machines.
12. Use according to Claim 11, characterised in that the hot beverage machines are designed for the preparation of coffee, tea and/or cocoa drinks.
13. Use according to Claim 12, characterised in that the cleaner is used to clean coffee conduits and milk conduits.
14. Use according to one of Claims 11 to 13, characterised in that the cleaner is additionally used to clean a milk foam compression unit.

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