EP3103859B1 - Phosphate-free and phosphonate-free dishwasher detergent - Google Patents

Description

The present invention relates to a phosphate and phosphonate-free machine dishwashing detergent in the form of a powder or tab.

Conventional machine dishwashing detergents contain 30% and more of phosphates. The function of this class of raw materials is to soften the water, improve the soil-carrying capacity of the wash liquor, and prevent the Schumtze from re-positioning on the dishes, acting as a complexing agent.

Disadvantage of phosphates, however, is that they can get into the sewage. Here they cause fertilization of the waters, which leads to increased growth and a decrease in the oxygen content. Against this background, from 2017 a low maximum phosphorus value for machine dishwashing detergents of 0.3 g per rinse cycle should be set. Products with such a content are colloquially then already referred to as phosphate-free.

Alternative complexing agents are difficult to find. This is especially the case if you do not want to resort to fully synthetic products.

Suitable complexing agents are, for example, Baypure® CX (fully synthetic, but based on natural chemical structures), Trilon® M (fully synthetic, but based on natural chemical structures), Dissolvin GL PD S (based on renewable raw materials, semisynthetic) and sodium citrate (natural ).

From an environmental point of view, sodium citrate, usually in the form of trisodium citrate, would be the first choice. However, the application results are not satisfactory here, as it leads to massive calcification.

WO 94/29420 A1 describes a machine dishwashing detergent which contains one or more amino acids or salts thereof and exhibits better properties with respect to limescale inhibition than conventional dishwashing detergents based on carbonate and / or bicarbonate. Amylxylosides are not mentioned here.

Szillágyiz, Z. et al. SOFW Journal, Vol. 139, No. 11 of 1 November 2013 describes Appyclean® 6505 as a hydrotrope for detergents and cleaners. An ability to reduce calcification is not described.

Further machine dishwashing detergents are in FR 2 913 896 A1 disclosed.

The object of the invention is therefore to provide a phosphate and phosphonate-free machine dishwashing detergent in the form of a powder or tabs, on the one hand contains natural complexing agents and on the other hand largely avoids the above-mentioned disadvantages of the prior art.

The object is achieved by a phosphate and phosphonate-free machine dishwashing detergent in the form of a powder or tab according to claim 1.

The present inventors have surprisingly found that by adding amylxylosides to the trisodium citrate a significant improvement of the complexing properties and thus a reduced deposit of lime can be achieved. This was therefore all the more surprising since amylxylosides themselves have no complex-forming properties.

The present invention therefore relates to a phosphate-free and phosphonate-free machine dishwashing detergent in the form of a powder or Tabs, characterized in that it contains a proportion of amylxyloside or amylxylosides, wherein the phosphate-free and phosphonate-free machine dishwashing agent releases a maximum of 0.3 g of phosphorus per wash cycle.

Phosphate-free or phosphonate-free is understood to mean that the machine dishwashing detergent releases a maximum of 0.3 g of phosphorus per wash cycle. Particularly preferably, the machine dishwashing detergent does not release any phosphorus in the rinse cycle.

Amylxylosides (also called pentylxylosides) are pentosides available from plant materials which have hydrotropic properties and are biodegradable. Xylosides are glycosides derived from the sugar xylose. They can be obtained, for example, from wheat bran, wheat fibers or wheat straw, as described in European patent no. EP 0 699 472 B1 is described. For example, commercially available amylxylosides are available as AppyClean ™ 6505.

The machine dishwashing detergent according to the invention preferably contains trisodium citrate as complexing agent, since a reduction in limescale deposits after the rinse has been found to be particularly marked when using amylxylosides in combination with trisodium citrate.

Trisodium citrate is a salt of citric acid. It is a food additive zuglassen, therefore, the use of dishwashing detergents harmless. Trisodium citrate (dihydrate) consists of colorless crystals and is readily soluble in water. It is used as a buffer and complexing agent. The function of the machine dishwashing detergent is, in particular, to inactivate hardness ions from the water and thus to avoid deposition on the dishes.

In addition to trisodium citrate, iminodisuccinate (Baypure® CX 100), Dissolvin GLPD S (L-glutamic acid-N, N-diacetic acid, tetrasodium salt) or Trilon® M (trisodium salt of methylglycinediacetic acid (Na3MGDA)). The anhydrous version of trisodium citrate (trisodium citrate anhydrate) can also be used.

In addition, polyaspartic acid (Baypure® DS 100) can also be used.

The machine dishwashing detergent according to the invention preferably contains the following components: at least one washing-active substance, namely sodium carbonate, also called soda, or sodium bicarbonate, at least one bleaching agent, e.g. Sodium percarbonate, trisodium citrate as complexing agent and at least one amylxyloside.

Furthermore, the machine dishwashing detergent according to the invention may contain at least one silicate.

Sodium carbonate or soda (Na ₂ CO ₃ ) is usually used as anhydrous, white powder. It is a highly hygroscopic raw material that reacts with acids to release carbon dioxide.

Na ₂ CO ₃ + H ₂ SO ₄ → Na ₂ SO ₄ + H ₂ O + CO ₂ .

Sodium carbonate is one of the wash alkalis that cause high pH and assist flushing by removing greasy soils and dispersing them. Sodium carbonate also inactivates interfering hardness ions by precipitating calcium salts.

Instead of or in addition to sodium carbonate, other washing-active substances such as e.g. Sodium hydrogen carbonate can be used.

Sodium percarbonate, however, is an oxidizing agent with the empirical formula Na ₂ CO ₃ * 3 H ₂ O ₂ , and chemically also sodium carbonate peroxohydrate. Hydrogen peroxide is deposited on the sodium carbonate in the form of a water of crystallization. It is a solid, white, water-soluble powder. Sodium percarbonate easily decomposes into sodium carbonate and oxidizing oxygen. Due to the oxidizing oxygen, the use as a bleaching agent.

In addition, as a bleach activator, e.g. TAED (Tetraacetylethylenediamine) can be used.

As silicates, for example, phyllosilicates such as e.g. SKS® 6 are used.

SKS® 6 belongs to the sodium disilicates and has the formula Na ₂ Si ₂ O ₅ . In a plane linked [SiO ₄ ] tetrahedra form so-called layer silicates with doubly coupled anions. These are therefore polymers of the anion [Si ₄ O ₁₀ ] ^4- . The layer lattice contains the sodium ions. First, when SKS® 6 contacts with water, the latter is deprotonated. This produces an alkaline solution:

Na ₂ Si ₂ O ₅ + 4H ₂ O → NaHSi ₂ O ₅ * 3H ₂ O + Na ⁺ + OH ^-

Furthermore, the phyllosilicate is a very good water softener by replacing the hardening calcium and magnesium ions (Me ²⁺ ) with sodium.

2 Na ₂ Si ₂ O ₅ + Me ²⁺ → Me (NaSi ₂ O ₅ ) ₂ + 2 Na ⁺

In this way, SKS® 6 ensures soft water in the rinsing solution and at the same time an alkaline washing solution. The granulated form of the SKS® 6 is ideal for use in machine dishwashing detergent.

Another suitable silicate for the machine dishwashing detergent according to the invention is Britesil® H265 HP, a white, granulated polysilicate. It is the solid form of water glass in the very concentrated state. Due to the special production process followed by spray-drying, different molar ratios, Particle sizes and bulk densities are produced. Britesil® offers benefits in terms of washing action and corrosion inhibition. Furthermore, the use should lead to water softening. The raw material Britesil® H265 HP is used with 22% Na ₂ O, 59% SiO ₂ and 17.5% H ₂ O.

Finally, a metasilicate, e.g. Sodium metasilicate, which is used in dishwashing detergents because of its fat-emulsifying, wetting, disinfecting and water-softening function, can be used as silicate for the machine dishwashing detergent according to the invention.

• 10 bis 40 Gew.-%, vorzugsweise 10 bis 30 Gew.-% Natriumcarbonat
• 5 bis 30 Gew.-%, vorzugsweise 10 bis 15 Gew.-% Natriumpercarbonat
• 10 bis 60 Gew.-%, vorzugsweise 10 bis 30 Gew.-% Trinatriumcitrat
• 0 bis 40 Gew.-%, vorzugsweise 10 bis 30 Gew.-% eines oder mehrerer Silikate
• 0,1 bis 30 Gew.-% mindestens eines Amylxylosids.

The machine dishwashing detergent according to the invention preferably contains the following components in the following quantities:

• 10 to 40 wt .-%, preferably 10 to 30 wt .-% sodium carbonate
• 5 to 30 wt .-%, preferably 10 to 15 wt .-% sodium percarbonate
• 10 to 60 wt .-%, preferably 10 to 30 wt .-% trisodium citrate
• 0 to 40 wt .-%, preferably 10 to 30 wt .-% of one or more silicates
• 0.1 to 30 wt .-% of at least one Amylxylosids.

In this case, this is at least one amylxyloside with in particular 0.1 to 25 wt .-%, preferably 0.5 to 20 wt .-%, particularly preferably 1 to 15 wt .-% and most preferably 1.5 to 10 wt. % contain.

The machine dishwashing detergent may also contain other additives customary for machine dishwashing detergents, e.g. Enzymes, surfactants, dyes and fragrances, and / or TAED included.

In a particularly preferred variant, the machine dishwashing detergent is free of polyaspartic acid and / or iminodisuccinate.

Furthermore, the invention relates to the use of amylxyloside or amylxylosides in phosphate-free and phosphonate-free Machine dishwashing detergents in the form of a powder or a tab for limescale reduction.

The present invention will now be described in more detail by way of examples.

It shows Fig. 1 the arrangement of the test glasses and glass plate in a dishwasher.

In the following Table 1, exemplary compositions of a machine dishwashing detergent of the present invention are described: Table 1: Composition of a preferred machine dishwashing detergent component Quantity in kg (add. % By weight (addition 1) % By weight (addition 2) sodium 7.92 13.2 13.16 Sodium carbonate (soda heavy) 15.96 26.6 17.18 sodium 0.00 0.00 10.28 trisodium citrate 16.74 27.9 27.87 Phyllosilicate SKS-6 10.02 16.7 16.69 Britesil H265HP 5.76 9.6 9.63 AppyClean ™ 6505 3.6 6 8.33 glycerin 0.00 0.00 0.20 total 60 100 103.33

The AppyClean ™ 6505 is preferably sprayed on because it contains water. Optionally, this can also be done drying. This can be done for example by spray granulation.

The machine dishwashing detergent according to the invention with composition 2 above was then tested for limescale on rinsing against various dishwashing detergents available on the market tested. The experiment was carried out as described below:

Carrying out the rinses:

For each batch, a test run with ballast dirt was carried out in the Constructa Energy 300 PA at 16.8 ° dH in the Eco program at 50 ° C without regeneration salt and rinse aid. For this, first high 450 ml beakers were thoroughly washed and dried. The clean, numbered glasses were then sorted in the machine according to a scheme that was in FIG. 1 is shown. The numbers 1 to 7 indicate the positions of the glasses, the gray bar shows the position of the glass plate. At least 5 glasses were tested. Furthermore, a glass plate with the DIN A4 format was washed in the lower compartment of the dishwasher.

The ballast dirt was placed in the sump of the machine and the program started.

Rinse cycle tests (5 and 15 times, respectively) were performed at 10 ° dH to eliminate scale formation. The glasses were not cleaned between the experiments, but examined after each rinse.

Synthetic water:

For the rinses, synthetic water with a hardness of 16.8 dH was used according to the IKW method. This makes sense because the water hardness for 63% of the population in Germany in the hard range over 2.5 mmol / l, i. above 14 ° dH.

• Lösung 1: 800 mmol/l NaHCO₃ 67,2 g/l
• Lösung 2: 154,2 mmol/l MgSO₄ * 7 H₂O 38,0 g/l
• Lösung 3: 446,1 mmol/l CaCl₂ * 2 H₂O 65,6 g/l

For preparation, 3 stock solutions of the following concentrations were prepared:

• Solution 1: 800 mmol / l NaHCO ₃ 67.2 g / l
• Solution 2: 154.2 mmol / l MgSO ₄ .7H ₂ O 38.0 g / l
• Solution 3: 446.1 mmol / l CaCl ₂ .2H ₂ O 65.6 g / l

In a 25 l canister 17.5 l of demineralized water were placed and mixed with 125 ml of the stock solution. It was then made up to 25 liters with demineralised water. The final rinse cycle experiments were performed at 21 ° dH and 10 ° dH to give rapidly meaningful results by changing the amount of stock solution per 25 l to 156 ml and 74 ml, respectively.

Ballast soil:

• Elektrisches Laborrührwerk
• Waage bis 1200 g, Genauigkeit 1 mg
• Kühl- und Gefrierkombination AEG Electrolux SANTO

The ballast dirt served to create a practice-relevant environment. The rinse liquor was thereby loaded with fat and protein components as well as carbohydrates in the form of starch and flour. Furthermore, ketchup and mustard were included. In addition to beakers and spatulas, the following devices were used:

• Electric laboratory agitator
• Scale up to 1200 g, accuracy 1 mg
• Refrigerator and freezer AEG Electrolux SANTO

The ingredients required for ballast soil and their dosage are shown in Table 2 below: Table 2: Ingredients for ballast soil ingredient Weighed in g for 2.5 kg Vegetable oil (sunflower oil) 790 margarine 157.5 lard 157.5 frying oil 157.5 whole egg 395 H-cream, 32% 235 Milk, pasteurized, 3.5% fat 157.5 potato starch 55 gravy 42.5 wheat flour 15 Quark powder 15 tomato ketchup 157.5 mustard 157.5

First, vegetable oil with whole egg was stirred together thoroughly for about 30 minutes. Then ketchup and mustard were added. The fats were melted and added after cooling to about 40 ° C. After the addition of milk and cream all powdered ingredients followed. After a smooth mass was formed, each 50 g of the ballast dirt were weighed into lockable bags and stored in the freezer.

Visual Rating:

Visual assessment depends on many external factors. Therefore, it was important to create constant conditions. For example, all glasses were always examined in the same place and under the same lighting conditions. There were already big differences in the comparison between daylight and artificial lighting. The latter was chosen because of the reproducibility. The evaluation of the glasses took place in two categories. A first note assessed the calcification in the form of drops and streaks on the glass. The second note described the formation or absence of a lubricating film on the glasses of varying thickness. The definition of grades shown in Table 3 below has been established. Table 3: Definition of the visual evaluation grade lime fat 1 Only a few drops Dry, clear 2 A few drops 3 Many drops Easy movie 4 Coarse limescale and many drops Slightly cloudy glass 5 Large scale limescale and streaks 6 Continuous limescale coating Dense, greasy surface, very cloudy glass

At least 5 glasses per wash were evaluated in this manner and at the end each averaged per category.

Image analysis evaluation:

A glass plate DIN A4 was rinsed in the machine. This was then used for a picture analytical evaluation. The glass plate was scanned in the HP Officejet Pro 8600 Plus. In the pictures, the drops of lime were very well recognizable. Table 4: Results Visual evaluation image analysis lime fat Area% Batch 1 (prior art) 2.3 3.2 0.871 Batch 2 (prior art) 2.9 3.3 0.953 Batch 3 (according to the invention) 2.2 2.7 0.584

Cycle tests:

In order to exclude the formation of deposits, cycle tests were carried out at 10 ° dH for batches 1 and 3.

At 10 ° dH without ballast dirt, the glasses were still clear and lime-free after 10 rinsing runs with batch 3. Only after 11 rounds it occasionally came to drops, from 12 passes were clear streaks recognizable. After 15 passes, drops were visible on some glasses.

In batch 1, the glasses were not so shiny clean from the beginning, on all glasses there were always drops of lime. After 6 passes, noticeable streaks were already noticeable, which only appeared after 12 passes in the previous test. After 10 passes, the glasses were covered with streaks and lime drops, after 15 passes all glasses were completely calcified. The calcification was even better seen when viewing the scan images due to the same lighting conditions.

This experiment clearly shows that the addition of amylxylosides, such as AppyClean ™ 6505, can significantly improve calcification.

Finally, batch 1 and the charge 3 according to the invention were compared in an experiment as described above with the commercially available competitor products Sonett® (without phosphates and polyaspates) and Somat® from Henkel (with phosphate). The results are shown in Table 5 below. Table 5: Results of comparative experiments with competing products product Visual evaluation lime fat Batch 3 (according to the invention) 2.2 2.6 Batch 1 2.3 3.2 Sonett® 3.0 3.3 Somat® 2.2 1.8

The machine dishwashing detergent according to the invention shows properties as good as the phosphate-containing agent Somat® with regard to lime deposits, and it is also the best agent among the non-phosphate-containing agents in the fat deposits.

Claims (10)

1. A phosphate-free and phosphonate-free dishwasher detergent in the form of a powder or tablet, characterised in that it contains a proportion of amyl xyloside or amyl xylosides, wherein the phosphate-free and phosphonate-free dishwasher detergent releases at most 0.3 g of phosphorus per wash cycle.
2. The dishwasher detergent according to claim 1, characterised in that it contains trisodium citrate as complexing agent.
3. The dishwasher detergent according to claim 1 or 2, characterised in that it contains the following components:

   at least one detergent, specifically sodium carbonate or sodium hydrogen carbonate;

   at least one bleaching agent;

   trisodium citrate as a complexing agent, and

   at least one amyl xyloside.
4. The dishwasher detergent according to any one of claims 1 to 3, characterised in that it additionally contains at least one silicate.
5. The dishwasher detergent according to any one of claims 1 to 4, characterised in that it contains sodium carbonate as a detergent substance.
6. The dishwasher detergent according to any one of claims 1 to 5, characterised in that it contains sodium percarbonate as bleaching agent.
7. The dishwasher detergent according to any one of claims 1 to 6, characterised in that it contains the following components:

   10 to 40 % by weight of sodium carbonate

   5 to 30 % by weight of sodium percarbonate

   10 to 60 % by weight of trisodium citrate

   0 to 40 % by weight of one or more silicates

   0.1 to 30 % by weight of at least one amyl xyloside.
8. The dishwasher detergent according to any one of claims 1 to 7, characterised in that it contains 0.1 to 25 % by weight, preferably 0.5 to 20 % by weight, particularly preferably 1 to 15 % by weight, and in particular 1.5 to 10 % by weight of at least one amyl xyloside.
9. The dishwasher detergent according to any one of claims 1 to 8, characterised in that it contains further additives that are conventional for dishwasher detergents, such as enzymes, surfactants, dyes and fragrances and/or TAED.
10. Use of amyl xyloside or amyl xylosides in phosphate-free and phosphonate-free dishwasher detergents in the form of a powder or tablet for reducing scale buildup.

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