DK167364B1 - MACHINE DETERGENT - Google Patents

Description

DK 167364 B1

Technical area

The present invention relates to a silver corrosion inhibiting machine dishwashing detergent comprising an oxygen donating bleach and conventional dishwashing detergent ingredients including any additional conventional adjuvants and / or fillers.

10 Technical Background

Traditionally, dishwashing detergents have been formulated on the basis of chlorine-containing bleaching agents.

15 In recent years, society and the individual citizen have become increasingly aware of the environmental consequences of the large consumption of dishwashing detergents with a chlorine-containing bleach content. This has resulted in an attempt to formulate alternative machine detergents to a greater and greater extent.

Thus, developments in machine dishwashing detergents are moving more and more towards chlorine-free, non-corrosive dishwashing detergents containing oxygen-donating bleaching agents.

25

Examples of such dishwashing detergents include Sun Progress®, a powdery phosphate-free, chlorine-free and non-corrosive dishwashing detergent from Lever, Germany, as well as "mild power" which is also a phosphate and chlorine-free, non-corrosive , powdered product marketed in Germany by Benckiser.

However, such bleaches have certain disadvantages to silver service in particular, in that during the washing process by corrosion 35 certain silver oxidation compounds are formed which give rise to a discolored yellowish or brownish surface covered with a loose white dusty layer. This trend is more or less pronounced for all currently available products on the market, which are based on oxygen-donating bleaches.

However, this problem is particularly pronounced for machine detergents with a high content of oxygen-donating bleach. The problem arises, for example. particularly applicable to machine dishwashing detergents available in tablet form, with tablets requiring a higher content of bleaches compared to powders due to a slower release of bleaches from tablets.

EP no. 135,226 discloses a peroxide content in gt machine low detergent with a low chloride content to prevent silver overflow. The document states that the tendency for silver overflow is related to the presence of chloride, especially alkali metal chloride, cf. 15 page 2, lines 28-31 of the document. Thus, the machine detergent contains at most 0.2% by weight of chloride and preferably at most 0.1% by weight of chloride, with the preference being that the agent is substantially free of chloride.

Such a low chloride content requirement can cause problems in formulating the agent, since many of the commercially available conventional detergent ingredients, such as enzymes, contain alpha potassium metal chloride or id. Furthermore, the effectiveness of the agent will depend on the chloride content of the wash water used and the amount of chloride supplied to the wash water with the dirty cutlery and service.

The use of detergents in the form of tablets is in itself an advantage, since tablets provide a convenient way to ensure a low and yet sufficient dosage.

It is therefore desirable to provide a chlorine-free machine dishwashing detergent which does not corrode silver service during the washing process even in the case of high levels of oxygen donating bleach.

Brief Description of the Invention 3 DK 167364 B1

The present invention relates to a silver corrosion inhibiting machine dishwashing detergent comprising an oxygen donating bleach and conventional dishwashing detergent ingredients including any additional conventional adjuvants and / or fillers, said machine dishwashing agent being comprised of a silver corrosion inhibiting compound selected from compounds which release.

The dishwashing detergent of the invention can be used with particular advantage when designing in tablet form, where the problems of silver corrosion are often particularly pronounced.

Examples of advantageous silver corrosion inhibiting compounds which can release ammonium ions are those selected from ammonium chloride, ammonium bromide, ammonium sulfate, diammonium hydrogen citrate and mixtures thereof.

The machine dishwashing detergent according to the invention advantageously contains the silver corrosion inhibiting compound in an amount of at least 20 0.03, preferably at least 0.7 and particularly advantageously at least 1.5 parts by weight of corrosion inhibiting compound, calculated as ammonium chloride, per minute. by weight of active oxygen, calculated as O 2, which can be released from the oxygen-donating bleach, and preferably at most 10.5, especially preferably at most 6.5, and most preferably not more than 5.3, 25 parts by weight of silver corrosion inhibiting compound, calculated as ammonium chloride, per part by weight of active oxygen.

The oxygen detergent bleach contained in the machine dishwashing agent may advantageously be a per-compound or a perhydrate or mixtures thereof.

A particularly advantageous recipe for the dishwashing detergent according to the invention is within the following limits: 35 DK 167364 B1 4% by weight

Oxygen-donating bleach 3-39

Bleach activator 1-13 5 Polycarboxylate 5-21

Polyfunctional carboxylic acid 0-30

Sodium silicate 5-10

Tensides 3-5

Enzymes 1-5 10 Silver Corrosion Inhibitor Compound 2-18

Sodium carbonate ad 100

It should be noted that the prescriptions are expressed on the basis of commercial products and thus do not express 100¾ active and anhydrous 15 ingredients.

DETAILED DESCRIPTION OF THE INVENTION The essence of the present invention is to avoid the discoloration and dust deposition on silver clothing which is a particularly pronounced problem in connection with a high content of oxygen donating bleach. Such a high content of oxygen-donating bleach is usually needed in tablet-based dishwashing detergents to ensure a sufficiently fast bleaching effect.

Examples of the oxygen-donating bleaches which may be mentioned are perhydrates and per-compounds as well as mixtures thereof. Preferably, the perhydrates include alkali metal compounds of perborates which may exist as tetra and monohydrates, perborax, percarbonates, persilicates, citrate perhydrates as well as perhydrates of urea and melamine compounds. Also mentioned are acidic persaltates such as persulfates 35 (e.g. caroates), perbenzoates and peroxycarboxylic acids such as peroxyphthalate, magnified in non-monoperoxyphthalic acid, di peroxyphthalic acid, 2-octyl diperoxyacetic acid, diperoxydodecandic acid, carboxylic acid, DK 16736 acid, imidoperoxycarboxylic acid and their salts and mixtures. As particularly preferred bleaches may be mentioned sodium percarbonate and sodium perborate.

5 For bleaching systems, reference can be made to P. Kuzel and Th. Li eser, Tenside Surf. That. 27 (1990) 1, pages 23-28.

The content of oxygen-donating bleach usually amounts to about 0.4-5.3 parts by weight of active oxygen per liter. 10 100 parts by weight of detergent, which in the case of sodium percarbonate equals approx. 3-39 parts by weight of sodium percarbonate per 100 parts by weight of detergent, sodium percarbonate containing 13.5% by weight of active oxygen.

As a silver corrosion-inhibiting compound, any compound which releases ammonium ions in the wash raft and which are active to form stable silver complex salts may be used at the same time as having no detrimental effect on the cleaning effect.

20

The other ingredients included in the machine dishwashing detergent according to the invention may be selected from conventional machine dishwashing ingredients, of course, provided that such ingredients are compatible with the oxygen donating bleach used and the silver corrosion used in the non-inhibiting compound. Thus, it is within the skill of the skilled artisan to formulate suitable machine dishwashing in parts by combining an oxygen donating bleach and a silver corrosion inhibiting compound on the basis of the requirements of the present application and selecting the other components of the machine dishwashing agent on the basis of the prior art.

The machine dishwashing detergent according to the invention is prepared in the form of tablets intended for use e.g. one or two tabs per dish cycle. In the manufacture of tablets, usually a loss of auxiliary substances, e.g. in the form of starch, glycerol, polyethylene glycol, preferably with a molecular weight of 100-10,000, polyvinylpyrrolidone (PVP), polyvinylpolypyrrolidone (PVPP) or a stearate compound such as sodium stearate. Such tablet excipients ensure proper consistency and granulation.

5

Tablet advancement for 11 days is carried out in a manner known per se, first forming a g round powder fraction comprising the solid ingredients contained in the dishwashing detergent which, for example, in the case of the following recipe 1 of Example 1, comprises bleach, bleach activator, polycarboxylate, polyfunctional carboxylic acid, silicate, enzymes, silver corrosion inhibiting compound and sodium carbonate. After a brief stirring for 1-5 minutes, liquid components are usually sprayed, usually comprising liquid surfactants, after which one or more tablet adjuvants can be sprayed or added followed by a final mixture for 2-10 minutes. The resulting powder mixture is pressed into tablets having a diameter of e.g. 32 mm in a tablet press (e.g. Pette Perfects 4B). The thickness of the tablets prepared depends on the desired tablet weight and formulation and is usually between 13 and 20 mm. Further examples of tablet preparation are disclosed in U.S. Patent No. 355,626, U.S. Patent No. 328,880, and U.S. Patent No. 3,827,895.

In a particularly preferred embodiment of the invention, wherein the machine dishwashing detergent is in tablet form, machine washing chemistry comprises a: 30 35 7 DK 167364 B1

Vgqt%

Oxygen-donating bleach 21.0

Bleach activator 7.0 Polycarboxy1 at 16.0

Polyfunctional carboxylic acid 15.0

Sodium carbonate 14.0

Sodium silicate 10.0

Surfactants 4.0 10 Enzymes 3.0 Silver Factor 10.0

Another embodiment of the invention in which mash in the instant detergent is in powder form is as follows: 15% by weight

Oxygen-donating bleach 15.0

Bleach activator 5.0 Polycarboxylate 10.0

Polyfunctional carboxylic acid 15.0

Sodium carbonate 33.0

Sodium silicate 5.0

Surfactants 4.0 25 Enzymes 3.0 Silver Factor 10.0 In the recipes shown above, the amount of bleach activator is. stated in case of TAED. Examples of non-limiting bleach activators include N-acyl compounds and O-acyl compounds, such as acylated amines, diamines, amides, acylated glycols in 1, N-acylated cyclic hydrazides, triazoles, urazoles, diketopiperazines, sulforylamides, cyanurates and imidazoles, carboxylic anhydrides, acylated sugar compounds, acylated ester compounds, and the like. Particularly preferred are tetraacetylmethylenediamine, tetraacetylethylenediamine (TAED) and higher homologues, tetraacetylglycoluril (TAGU), pentaacetylglycose (PAGE), p-hydroxybenzenesulfonate (sodium sulfonates) -triumoktanoy1oxybenzensu1fonat. Most preferred is TAED, which may be present as a granule with an active content of 85-95% by weight.

A more detailed description of, among other things, activators can be found in GB Patent No. 2040983 and GB Patent No. 1473201.

Examples of the polycarboxylate used may be mentioned polymers of acrylic acid, hydroxyacrylic acid, maleic acid, itaconic acid, metaconic acid, acutinic acid, methylene malonic acid, citraconic acid and the like, and copolymers of said carboxylic acids among themselves or with other ethylenically unsaturated compounds, propylene, isobutylene, vinyl alcohol, vinyl methyl ether, furan, acrolein, vinyl acetate, acrylamide, acrylonitrile, methacrylic acid or crotonic acid.

The molecular weight of the polycarboxylate may range from 20,000-1,000,000, preferably 2000-100,000 and most preferably 7,000-30,000.

Regarding polycarboxylates, reference can be made to an article by J. Perner and H.-W. Neumann, entitled "Polycarboxylate in the Cleaning of Textiles and Non-Textile Substrates", Tenside Surfactants Detergents 24 (1987) 6, pages 334-340.

In the recipes shown above, the weight data for the polyfunctional carboxylic acid refers to anhydrous citric acid. Useful polyfunctional carboxylic acids can generally be defined as those which, in addition to the one mandatory carboxylic acid group, also contain at least one additional functional group selected from carboxyl and hydroxy, at the same time that nitrogen may also be included in the molecule in some cases. In addition to citric acid, examples of such polyfunctional le carboxylic acids may be mentioned NTA, EDTA and isoserinediacetic acid having the formula (CH2C00H) 2N-CH2CHOHC00H.

9 DK 167364 B1 The following examples illustrate the preparation of machine dishwashing detergents according to the invention.

Example 1 5

From the following prescription, tablets weighing 18.0 g, a diameter of 32.0 mm and a height of 15.0 mm were prepared. Ammonium chloride was used as the silver factor (SF).

10 Recipe 1 (with 10.0 wt% silver factor) Weight%

Sodium percarbonate (bleach) 21.0

Sodium carbonate 14.0 Sodium di s in 1 in cat 10.0

Citric acid, anhydrous 15.0

Sokalan® PA 40 G (polymer) * 15.9 Silver factor 10.0 TAED ** 7.0 20 Plurafac® LF 403 (nonionic surfactant) *** 4.1

Enzymes 3.0 100.0 * Sokalan® PA 40 is a powdery polyacrylate in the form of the sodium salt having a molecular weight of approx. 15,000, supplied by BASF, Germany.

Hoe 4049, tetraacetylethylenediamine, is supplied by Hoechst AG, Frankfurt, Germany.

30

JL

Plurafac® LF 403 is a low-foaming, nonionic surfactant in the form of ethoxylated fatty alcohol, supplied by BASF, Germany.

35 DK 167364 B1 10

Example 2

From the following prescription, tablets weighing 18.0 g, a diameter of 32.0 mm and a height of 15.0 mm were prepared. 5 As a silver factor (SF), ammonium chloride was used.

Prescription 2 (with 5.0 wt% silver factor) Weight% 10 Sodium Percarbonate 21.0

Sodium carbonate 19.0

Sodium Dissicate 10.0

Citric acid, anhydrous 15.0

Sokal an® PA 40 G 15.9 15 Silver Factor 5.0 TAED 7.0

Plurafac® LF 403 4.1

Enzymes 3.0 100.0 20

Example 3 The present example illustrates a comparative experiment made between tablet-shaped dishwashing detergents according to the invention containing 10% and 5% silver factor respectively in the form of ammo ni um chloride as set forth in Examples 1 and 2, a recipe similar to that in Example 1 stated, however, without the content of silver factor (prescription A) as well as a leading powdered product on the market "MILDE KRAFT" (prescription B), which is based on an oxygen-donating bleach.

The prescription without silver factor is as follows: 35 11 DK 167364 B1

Recipe A (without silver factor) Weight%

Sodium Percarbonate 21.0 Sodium Carbonate 24.0

Sodium Dissicate 10.0

Citric acid, anhydrous 15.0

Sokalan® PA 40 G 15.9 TAED 7.0 10 Plurafac® LF 403 4.10

Enzymes 3.0

The experiment was carried out under the following experimental conditions: Dishwasher: Cylinda E 1502

Temperature: 55 ° C - no prewash

Water hardness: 20 ° dH and 2 ° dH

20

Dosage: 1 tablet of 18 g

Number of dishes: 5 25 Experimental item: 3 different types of three-tower silver spoons, all of which are clean.

After the 6 dishes, each of the three spoons was visually judged partly for brownish / yellowish discoloration and partly for loose 30 dust deposits.

A scale of 0-4 was used, where 0 indicates no discoloration and no dust deposition, respectively, and 4 indicates severe discoloration and strong dust deposition, respectively.

The results are given in the following Table 1, in which the sum of the point values for the 3 different silver spoons rated 35 DK 167364 B1 12 for brownish / yellow discoloration and loose dust deposits are given as well as the total sum thereof. Thus, the best achievable total sum is 0 and the least achievable total sum is 24.

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As can be seen from the dishwashing experiment, the machine dishwashing detergents of the invention are superior to a substantially poorer silver cutlery corrosion. Thus, for the machine dishwashing agents of the invention (recipes 1 and 2), at a water hardness of 20 ° dH total sums from 6-13 are obtained. MILDE KRAFT (Prescription B), a representative of the best phosphate-free and chlorine-free, non-corrosive powdery products on the market, when used at a dose of 25 g, significantly greater corrosion is shown by dust deposition and discoloration, with 10 the total sum is 15. The same is true for prescription A, where the total sum is also 15.

The table further shows that the less water hardness, the less pronounced the problem of discoloration and dust deposits.

Example 4 The present example illustrates a comparative experiment conducted between tablet-like dishwashing detergents according to the invention and for comparison with tablets according to prescription A and MILDE KRAFT (prescription B). During the experiment, corrosion of silver spoons as indicated in Example 3 was determined and partly the cleaning effect on other steel cutlery and other service, which was soiled in accordance with the guidelines of the International Electrotechnical Commission (IEC).

In the following Table 2, the composition of recipes 3-6 is as follows: 30

Recipe 3 (with 10¾ silver factor)

This prescription is like prescription 1, however, instead of citric acid as a solubility enhancing compound, monosodium citrate, anhydrous, is used.

DK 167364 B1

Recipe 4 (with 10¾ silver factor)

This prescription is similar to prescription 1 except that silver factor diammonium hydrogen citrate is used instead of 5 ammonium chloride.

Recipe 5 (with 10¾ silver factor)

This recipe is similar to recipe 1 except that 10 silver factor is used instead of ammonium sulphate instead of ammonium chloride and in this recipe TAED is used with the trade name TAED ATC from Warwick International Ltd., Mo-styn, North Wales. , instead of TAED, provided by Hoechst.

15 Recipe 6 (with 10¾ silver factor)

This prescription is similar to prescription 1 except that silver is used as a silver factor instead of ammonium chloride.

20

The cleaning effect was determined partly on steel cutlery and partly on other services, ie. cups, plates, glasses, etc., which were soiled in accordance with the guidelines of I EC (International Electrical Engineering Commission). 25 The steel cutlery and other service were thus washed together with the silver spoons.

In the washing experiments, point values were given as follows: 30

After each dish, each cup, plate, knife, fork, etc. was evaluated from a scale of 1-5 points. The point values were calculated for steel cutlery, various plates and glassware, which were soiled with non-tea containing dirt, as well as for 35 teacups, which were soiled with tea. Furthermore, a total point value was calculated. The obtained point values are given in the following Table 2, where 100% indicates the maximum achievable cleaning effect.

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Claims (13)

5 It is seen that the use of ammonium sulphate as a silver factor (prescriptions 5 and 6) causes a very high ability to prevent loose dust deposits, but a scarcely good ability to prevent discoloration in comparison with ammonium chloride (prescription 1). 10 Furthermore, it appears that the use of monosodium citrate, anhydrous (prescription 3) in place of citric acid (prescription 1) as solubility enhancing compound is not essential to the results obtained neither in terms of corrosion nor cleaning effect. Regarding the cleaning effect, it is seen that the machine dishwashing agents of the invention (recipes 1 - 6) and prescription A and prescription B at a water hardness of 20 ° dH have substantially the same effect with regard to tea-containing stains. With regard to non-containing stains and the total, no significant difference is seen either. In terms of the cleaning effect, the machine detergents according to the invention are thus satisfactory and comparable to the best products on the market. 25 Patent claims. A silver corrosion inhibiting machine dishwashing agent comprising an oxygen donating bleach and conventional machine dishwashing ingredients including any additional conventional adjuvants and / or fillers, characterized in that it comprises a silver corrosion inhibiting compound selected from compounds which release ammonium ions. 1 Machine detergent according to claim 1, characterized in that it is in tablet form. DK 167364 B1 Machine detergent according to claim 1, characterized in that the silver corrosion inhibiting compound is selected from ammonium in chlorine d, ammonium in umbromide, ammonium sulphate, di ammonium in um hydrogen citrate and mixtures thereof. 5 Machine wash detergent according to claim 1, characterized in that the silver corrosion inhibiting compound is present in an amount of 0.03-10.5 parts by weight, calculated as ammonium chloride, per unit weight. by weight of active oxygen, calculated as O2, which can be released from the oxygen donating bleach. Machine dishwashing detergent according to claim 3, characterized in that it contains 0.7-6.5 parts by weight of silver corrosion inhibiting compound, calculated as ammonium chloride, per unit weight. part by weight of active oxygen. Machine detergent according to claim 3, characterized in that it contains 1.5-5.3 parts by weight of silver corrosion inhibiting compound, calculated as ammonium chloride, per unit weight. part by weight of active oxygen. Machine dishwashing detergent according to any one of the preceding claims, characterized in that the oxygen-donating bleaching agent is selected from per compound or perhydrate or mixtures thereof. Machine detergent according to any one of the preceding claims, characterized in that it comprises: 30 1 5 DK 167364 Bl We 51: V Oxygen-donating bleach 3-39 Bleach activator 1-13 5 Polycarboxy1 at 5-21 Polyfunctional carboxylic acid 0-30 Sodium silicate 5-10 Surfactants 3-5 Enzymes 1-5 10 Silver Corrosion Inhibitor Compound 2-18 Sodium Carbonate ad 100 15 25 30 35