EP0171006A2 - Dish cleaning agent - Google Patents

Abstract

The agents are suitable for use at low temperatures and are based on polymeric alkali metal phosphates and/or their substitutes, alkali metal silicates, alkali metal carbonates and, where appropriate, compounds which release active oxygen, and low-foam non-ionic surfactants. They contain enzymes and primary C8-C18-alkylamines which can, where appropriate, be alkoxylated or quaternised.

Description

The invention relates to dishwashing detergents, in particular for the automatic washing of dishes at low temperatures, which are distinguished by a high level of cleaning ability, in particular also in relation to stubborn and normally difficult to remove soiling, such as sebum / grease soiling, and by an extraordinarily low foaming ability.

It is known that alkaline cleaning agent mixtures are used for the automatic cleaning of dishes, which essentially consist of inorganic salts such as alkali phosphates, alkali silicates and alkali carbonates and of active chlorine carriers and which, in order to improve the wetting effect, may also contain minor additions of a low-foaming nonionic surfactant. These mixtures have a good cleaning ability against all stains at generally normal working temperatures of 55 to 65 ° C. In order to prevent thin deposits, which can settle over time on the surface of the dishes, which consist essentially of starch and possibly traces of protein and which may significantly impair the appearance of the washed dishes, improved, enzyme-containing dishwashing detergents have been used, as described, for example, in DE-OS 17 67 567 are described.

Due to the need to save energy, many manufacturers have already launched dishwashers on the market as energy-saving models, in which the water consumption of the cleaning fleet has not only been reduced from 10 to 6 to 7 liters, but also offer a savings program with a greatly reduced temperature. A "Favorit de Luxe Elektronik i" household dishwashing machine put on the market by AEG only needs about 6 liters of water for the cleaning liquor, for example. The power consumption of the "40 ° C Normal" program (rinse aid temperature: 55 ° C) is only 1.1 kW / h, in contrast to the previously usual consumption of 1.9 to 2.2 kW / h at 65 ° _C . When working with this machine, however, it has been shown that the cleaning performance of - as usual - 30 g standard cleaner (~ 5 g / l) when changing from the 65 ° C program to the 40 _C program with 8 test stains by an average of 1 , 4 evaluation points dropped.

While adding 1% of an amylase-protease mixture in the cleaning cycle improved the removal of oatmeal and starch residues, adding a lipase to the cleaner to increase fat removal was not very effective. Sebum grease stains were difficult to remove at temperatures around 40 ^° C.

Surprisingly, it has now been found that the removal of particularly stubborn grease stains, such as. B. beef tallow at cleaning temperatures by 40 C above the normal known 65 ° C result is also improved if the dishwashing detergent as well as an enzyme mixture as a cleaning enhancer primary C ₈ -C ₁₈ alkylamines, which may also be alkoxylated or quaternized by methyl halides or dimethyl sulfate can be added.

The invention therefore relates to agents for the mechanical cleaning of dishes based on polymeric alkali phosphates and / or their substitutes, alkali silicates, alkali carbonates and, if appropriate, compounds which release active oxygen and low-foaming nonionic surfactants, which are characterized in that they contain enzymes and primary C ₈ -C ₁₈ - Alkylamines, which may optionally be alkoxylated or quaternized by methyl halides or dimethyl sulfate.

The cleaning agents according to the invention consist in particular of a combination of 0 to 50, preferably 10 to 40% by weight of a polymeric alkali metal phosphate from the group of alkali metal diphosphates and alkali metal triphosphates, O to 60, preferably 5 to 50% by weight of water-insoluble, complexing agents Zeolites of the NaA or NaX type or their mixtures or water-soluble organic complexing agents for calcium, at least one of these compounds or one of the polymeric alkali metal phosphates must be present, 10 to 60, preferably 20 to 50% by weight of alkali metal silicate, 2 to 40, preferably 5 to 30% by weight sodium carbonate, O to 20, preferably 5 to 20% by weight sodium hydrogen carbonate, 1 to 20, preferably 1 to 15% by weight water glass, 0.1 to 5, preferably 0.5 to 3% by weight .-% of an enzyme or enzyme mixture from the group of hydrolases, preferably amylases, proteases and lipases, 0.1 to 10, preferably 0.5 to 5% by weight of primary C ₈ -C ₁₈ -alkylamines, which may optionally still be alkoxylated or quaternized by methyl halides or dimethyl sulfate, 0 to 10, preferably 0.5 to 5% by weight .-% of active. oxygen-releasing compounds, optionally also activators for these and 0 to 5, preferably 0.5 to 2 wt .-% of a low-foaming nonionic surfactant from the group of alkylene oxide adducts with C12-C18 alkanols, nonylphenol or with polypropylene glycols Molecular weights 900 to 4,000.

Suitable polymeric alkali metal phosphates are the condensed phosphates which are customarily used in washing-up and cleaning agent mixtures and which can be present in the form of their alkaline neutral or acidic sodium or potassium salts. Examples include: tetrasodium pyrophosphate, disodium dihydrogen pyrophosphate, pentasodium triphosphate, sodium hexametaphosphate and the corresponding potassium salts or mixtures of sodium and potassium salts.

As is well known, the phosphate content of detergents in general is increasingly being made responsible for water reutrophication by experts and the public and is therefore regarded as a disadvantage. A number of substances have therefore been proposed as a replacement for the detergent phosphates which have been customary to date. Sodium aluminum silicates in the form of the synthetically produced zeolites of the NaA and NaX type, as described, for example, in US Pat. Nos. 2,882,243 and 2,882,244, have apparently proven to be the best and have become established. The zeolites are used in their hydrated form.

The water-soluble organic complexing agents for calcium are essentially found among the polycarboxylic acids, hydroxycarboxylic acids, aminocarboxylic acids, carboxyalkyl ethers, polyanionic polymeric carboxylic acids and the phosphonic acids, these compounds mostly being used in the form of their water-soluble salts. Specific but not exhaustive examples are citric acid, carboxymethyl tartronic acid, mellitic acid, polyacrylic acid, poly-K-hydroxyacrylic acid, carboxymethyl malic acid, nitrilotriacetic acid and 1-hydroxy-ethane-1,1-diphosphonic acid.

Water-soluble sodium or potassium metasilicates are used as alkali metal silicates. You can free of water, or anhydrate kristallwasserhalti ^g and containing from 5 to 9 moles of water.

Water glass is understood as meaning water-soluble sodium or potassium silicates in which the ratio of alkali oxide to silicon dioxide is approximately 1: 2 to 1: 4. They can be used as anhydrous solid substances or as liquid, approximately 50% solutions.

Such enzymes are those of animal and vegetable origin, in particular active substances obtained from digestive ferment, yeast and bacterial strains. They usually represent a complex mixture of different enzymatic active ingredients. Of particular interest are starch, protein or fat-cleaving enzymes, such as amylases, proteases and lipases. The enzymes are obtained from a variety of processes from bacterial strains, fungi, yeasts or animal organs and are sold under different names. Most of these are enzyme mixtures that have a combined effect on starch, protein and fats have. The enzyme preparations obtained from Bacillus subtilis have the particular advantage for practical use that they are relatively resistant to alkalis. The temperature sensitivity of the enzymes no longer plays a significant role here.

The manufacturers set the enzymes to a certain degree of activity, optionally with the addition of blending agents such as sodium sulfate, sodium chloride, alkali phosphates or alkali polyphosphates. The data in LVE / g (Löhlein-Volhard units per gram), IU (international units) and DE / g (Delft units per gram) are common for proteolytic enzymes. Because of the simple analysis method, the activity is often stated in LVE / g. In the dishwashing detergents according to the invention, the proteolytic enzyme activity should be 100 to 5,000, preferably 200 to 2,000 LVE / g. Amylolytic activity is generally reported in SKB / g (Sandstedt-Kneen-Blish units per gram). It should be about 5 to 1,000, preferably 15 to 250, SKB / g in the detergent mixture. The amount of the enzymes to be used in the dishwashing detergents depends on these values.

The primary alkyl amines contain 8 to 18, preferably 8 to 16 carbon atoms in the alkyl radical. They can be alkoxylated with 1 to 5, preferably 2 to 4, moles of ethylene oxide or ethylene oxide and propylene oxide in any order. Preferred are n-octylamine, n-decylamine, n-dodecylamine, and mixtures thereof, preferably C12-C14 or _C12-C18 -Alkylamingemische, were attached to the 2 moles of ethylene oxide. The amines can also be quaternized in a conventional manner, preferably by methyl halides or by dimethyl sulfate. Examples include n-dodecyltrimethylammonium chloride and C ₁₂ -C ₁₈ alkyltrimethylammonium chloride.

The known alkali perborates, persulfates and percarbonate, which can be activated by activators such as tetraacetylethylenediamine, tetraacetylglycoluril, pentaacetylglucose, but also compounds such as magnesium monoperphthalate, can be used as compounds which release active oxygen, but also compounds such as magnesium monoperphthalate, it being possible to dispense with the addition of activator.

Suitable nonionic low-foaming surfactants are preferably ethylene oxide adducts with higher molecular weight polypropylene glycols with a molecular weight of 900 to 4,000, and ethylene oxide or ethylene oxide and propylene oxide adducts with C ₁₂ -C ₁₈ alkanols and nonylphenol. The preparation is carried out in a known manner by addition of the alkylene oxides in question in the presence of mostly alkaline catalysts, if appropriate under pressure and at elevated temperatures, it being possible to add up to three times the amount by weight of the starting compounds on alkylene oxides. Examples of suitable addition products are the adduct of 10% by weight of ethylene oxide with a polyoxypropylene glycol of molecular weight 1750, and the adduct of 9 mol of ethylene oxide and 10 mol of propylene oxide with nonylphenol, and the like.

The useful nonionic surfactants also include the surface-active amine oxides, which are usually derived from tertiary amines with a hydrophobic C ₁₀ -C ₂₀ alkyl group and two shorter alkyl and / or alkylol groups each containing up to 4 C atoms. Typical representatives are, for example, the compounds N-dodecyl-N, N-dimethylamine oxide, N-tetradecyl-N, N-dihydroxyethylamine oxide or N-hexadecyl-N, N-bis (2,3-dihydroxypropyl) amine oxide.

In addition to the constituents mentioned, the claimed mixtures may contain further components, in particular inorganic salts such as sodium sulfate, as a blending agent. In addition, acidic or alkaline or buffering inorganic or organic compounds can be used to establish a pH value which is advantageous for the enzyme action. For this purpose, preference is given to the organic hydroxycarboxylic acids, such as citric acid or tartaric acid, which are also used as complexing agents, and also phosphoric acid or acidic alkali orthophosphates. In general, the pH values are between 4 and 12, depending on the type of enzyme. Finally, enzyme-activating additives such as ammonium chloride, sodium chloride, dyes, perfumes and the like can also be added to the mixtures.

The claimed agents are generally used as mixtures of granular or powdery individual substances or as granulated, agglomerated or prilled products.

The claimed cleaning agent combinations are characterized by a high wetting effect and an extraordinarily good low-temperature cleaning ability, especially in relation to stubborn stains, such as grease, protein and starch deposits.

The application takes place by adding the powdered, granulated, agglomerated or prilled agents by hand into the dishwashing liquor or preferably by means of automatic dosing devices. The use concentrations in system cleaning ^g sflotte to / be about 2 to 7 g of 1, wherein temperatures are employed from about 40 to 45 ° C.

To test the cleaning ungsergebnisses ^g of inventive detergents plates were further purified with potato starch and Haferbreianschmutzun ^g s and with Fettstift- and Rindertalgbelägen, bowls of milk, pudding and Hackfleischanschmutzungen and cups with dried Teeresten. The experiments were carried out in one Household dishwasher (HGSM) type AEG "Favorite de Luxe Electronics i" with Düsseldorf city water (16 ° d) carried out, which had the following program steps:

30 g of detergent, corresponding to 5 g / 1 liquor, were used in the cleaning cycle. No rinse aid was added in the rinse aid in order not to falsify the cleaning results. At the end of the entire program, the cleaning ability of the cleaning agents used was visually assessed. The individual evaluations were carried out according to a point system which ranged from 0 to 10, with 0 points meaning "without a recognizable cleaning effect" and 10 points meaning "complete removal of the test soiling". This resulted in a number of intermediate values that made it possible to make a differentiated statement. The results represent mean values from 4 parallel assessments by 4 test subjects.

The test soils consisted of oatmeal porridge and starch in the form of mashed potatoes, which were placed on plates and scraped off. The dishes were then left to stand in the air for 6 hours at room temperature and then placed in the dishwasher. In the Rindertalganschmutzung was pre-gen as follows, ^g: 0.5 to 0.8 g of beef tallow were heated until liquefied and stirred for about 2% of titanium dioxide. Then the still warm mass was spread evenly onto red plastic plates using a brush. First, a conventional standard cleaning agent (A) was used, which had the following composition:

Cleaner A:

• 40% by weight sodium triphosphate, anhydrous,
• 45% by weight sodium metasilicate, anhydrous,
• 5% by weight sodium carbonate, anhydrous,
• Rest of water

There have been other detergent compositions using other inorganic complexing agents, such as. B. sodium aluminum silicates of the type NaA or NaX or organic complexing agents, such as. B. the sodium salt of nitrilotriacetic acid as a partial or full phosphate substitute with in.die investigations included. These cleaners had the following compositions:

Cleaner B:

• 20% by weight sodium triphosphate, anhydrous,
• 20% by weight of zeolite NaA, (calculated as anhydrous substance),
• 45% by weight sodium metasilicate, anhydrous,
• 5% by weight sodium carbonate, anhydrous,
• Rest of water

Cleaner C:

• 40% by weight of zeolite NaA (calculated as anhydrous substance),
• 45% by weight sodium metasilicate, anhydrous,
• 5% by weight sodium carbonate, anhydrous,
• Rest of water

Cleaner D:

• 20% by weight sodium triphosphate, anhydrous,
• 20% by weight nitrilotriacetic acid, sodium salt,
• 45% by weight sodium metasilicate, anhydrous,
• 5% by weight sodium carbonate, anhydrous,
• Rest of water

Cleaner E:

• 40% by weight nitrilotriacetic acid, sodium salt,
• 45% by weight sodium metasilicate, anhydrous,
• 5% by weight sodium carbonate, anhydrous
• Rest of water

Bei den nachfolgenden Beispielen wurden 4 Gew.-%, entsprechend 1,2 g, des Natriummetasilikats der Standardrezeptur A durch 1 Gew.-%, entsprechend 0,3 g, eines 1 : 1 Gemisches aus Amylase und Protease (Maxamyl (^R) bzw. Maxatase (R) der Firma Koninklijke Nederlandsche Gist en Spiritus-Fabriek N.V., Delft) und 3 Gew.-%, entsprechend 0,9 g, der in der vorliegenden Tabelle angegebenen Aminverbindungen (als solche, ethoxyliert oder quaterniert) ersetzt.The cleaning results are shown in Table 1 below. It shows that the use of cleaning agents of the conventionally varied recipes given above leads to a considerably reduced cleaning performance when the cleaning temperature is reduced by 25 ° C.

In the following examples, 4% by weight, corresponding to 1.2 g, of the sodium metasilicate of standard formulation A was replaced by 1% by weight, corresponding to 0.3 g, of a 1: 1 mixture of amylase and protease (Maxamyl ( ^R ) or Maxatase (R) from Koninklijke Nederlandsche Gist en Spiritus-Fabriek NV, Delft) and 3% by weight, corresponding to 0.9 g, of the amine compounds given in the table at hand (as such, ethoxylated or quaternized).

Claims (2)

1. Dishwashing detergent based on polymeric alkali phosphates and / or their substitutes, alkali silicates, alkali carbonates, as well as optionally active oxygen-releasing compounds and low-foaming nonionic surfactants, characterized in that they contain enzymes and primary C ₈ -C ₁₈ alkylamines, which may be alkoxylated or quaternized can be included. 2. Composition according to claim 1, characterized in that they from a combination of O to 50, preferably 10 to 40 wt .-% of a polymeric alkali metal phosphate from the group of alkali metal diphosphates and alkali metal triphosphates, O to 60, preferably 5 to 50 _G ew. % of water-insoluble, complex-forming zeolites of the NaA or NaX type or their mixtures or water-soluble organic complexing agents for calcium, at least one of these compounds or one of the polymeric alkali metal phosphates being present, 10 to 60, preferably 20 to 50% by weight of alkali metal silicate , 2 to 40, preferably 5 to 30% by weight sodium carbonate, 0 to 20, preferably 5 to 20% by weight sodium hydrogen carbonate, 1 to 20, preferably 1 to 15% by weight water glass, 0.1 to 5, preferably 0.5 to 3% by weight of an enzyme or enzyme mixture from the group of the hydrolases, preferably amylases, proteases and lipases, 0.1 to 10, preferably 0.5 to 5% by weight primary C ₈ -C ₁₈ -alkylamines, which may also be alkoxylated or quaternized by methyl halides or dimethyl sulfate, 0 to 10, preferably 0.5 to 5% by weight of compounds which release active oxygen, optionally also activators for these and O to 5, preferably 0.5 to 2% by weight of a low-foaming nonionic surfactant from the group of the alkylene oxide adducts with C ₁₂ -C ₁₈ -alkanols, nonylphenol or with polypropylene glycols with a molecular weight of 900 to 4,000.