NO146697B - Aqueous storage-stable concentrates of microbicides by way of oxidizing mixtures based on percarboxylic acids and hydrogen peroxide - Google Patents

Description

The object of the invention is aqueous storage-stable concentrates of microbicide or oxidizing mixtures based on aliphatic monopercarboxylic acids and H2O2.

It is known that the solution of peracetic acid and perpropionic acid forms functional agents, which can be used for various purposes. They are, for example, suitable for oxidation of organic material in general as well as for treating hair, straw and textiles. In particular, however, they can

are used as microbicide and virucidal agents. Peracetic acid is preferably used. •

However, the pure peracids are not only problematic with regard to their production, but also because of their fire and explosion hazard, difficult to handle. In practice, the acid is therefore not used in its pure form, but in mixtures of, for example, 35 to H5% peracetic acid and 40 to 55% acetic acid. The proportion of water is usually below 15%. The disadvantage of these concentrates lies in the fact that, due to their pungent smell and their corrosive effect, they can only be handled by the consumer, who must first of all dilute the concentrates under strict safety precautions. On the other hand, concentrates are made from, for example, 5 to 25% by weight of peracid alone and the rest water, so

are these not shelf-stable.

It has now been found that one can avoid the above-mentioned disadvantages and obtain storage-stable concentrates of microbicide or oxidizing mixtures based on aliphatic monopercarboxylic acids, when these are characterized in that they contain 0.5 to 20% by weight peracid with 2 or 3 carbon atoms and/or equivalent aliphatic monocarboxylic acids as well as 25

to 40% by weight h^CUjWater, as well as possibly phosphonic acid and/or wetting agents.

Preferably, the storage-stable H202-containing concentrates are characterized by a content of 5 to 10 wt/S peracetic acid and/or acetic acid and a molar excess of # 2®2 to Peracid> the latter calculated as monocarboxylic acid,

of at least 2:1, preferably 3:1 to 50:1. The preparation takes place in a simple way by mixing H2O2 solution, preferably with a concentration of approx. 33 wt$ with peracetic acid and possibly acetic acid. In an advantageous manner, the mixtures can also be prepared by simply mixing the concentrated H 2 O 2 solution with the corresponding amount of acetic acid. As the products are mostly not directly supplied to the consumer, but first stored, a corresponding content of peracetic acid is established. The formation of peracetic acid can, if desired, be accelerated catalytically with a small amount of mineral acid (0.1 to 1%). Usually, however, such an addition is not necessary for the above reasons.

Such concentrates, for example made from 30$ H202, 5% acetic acid and 65% water, no longer have a disturbing smell and are easy to handle, i.e. they can be easily diluted to the usual application concentrations in the food technology and medical sector from 0.1 to 1% without the need for considerable precautionary measures.

It was further found that concentrates for the production of microbicide agents with increased effect are obtained on the basis of the above-mentioned components, when these additionally contain 0.25 to 10% by weight of phosphonic acid or their acid salts.

With phosphonic acid, it is within the scope of the invention

to understand those capable of complexing divalent metal cations, especially calcium. Thus, a larger number of phosphonic acids are taken into consideration which, in addition to the phosphonic acid groups, can optionally also contain carboxyl groups. Suitable phosphonic acids are thus compounds with the formulas

where R means phenyl radical, cycloalkyl radical or alkyl radical with 1 to 6 C atoms, R 2 and R , means hydrogen atom or alkyl radical with 1 to 4 C atoms or compounds which

aminotrimethylenephosphonic acid,

dimethylaminomethanediphosphonic acid,

aminoacetic acid-N-N-dimethylphosphonic acid,

ethylenediamine-tetramethylene-phosphonic acid,

3-aminopropane-1-hydroxy-1,1-diphosphonic acid,

2-phosphonobutane-1,2,4-tricarboxylic acid,

phosphonosuccinic acid as well

1-phosphono-l-methylsuccinic acid.

In particular, it comes into consideration

dimethylaminomethane diphosphonic acid,

1-amino-1-phenylmethanediphosphonic acid,

aminotrimethylenephosphonic acid,

aminoacetic acid-N-N-dimethylphosphonic acid,

1-hydroxyethane-1,1-diphosphonic acid.

Instead of the listed phosphonic acids, their acidic water-soluble salts can also be used, such as sodium, potassium, ammonium or alkanolamine salts. If desired, mixtures of the individual phosphonic acids or their acidic salts can also be used.

Due to the many-sided possibility of application - of the above-mentioned functional agents, for example for oxidation of organic material in general or for the treatment of hair, straw or textiles as well as as microbicide and virucidal agents, it is in many cases advantageous to use these at the same time and with the addition of a wetting agent for further to improve the desired characteristics.

It was found that storage-stable concentrates of the above-mentioned type are obtained when anionic wetting agents in the form of alkylbenzene sulphonate, alkyl sulphate and/or alkyl sulphonate are added in amounts from 0.05 to 5 wt/S.

As alkylbenzenesulfonates, those which contain an alkyl residue from 6 to 18 carbon atoms come into consideration. preferably 9 to 15 carbon atoms. Instead of alkylbenzene sulfonates, alkyl sulfates or alkyl sulfonates with an alkyl residue of chain length 12 to 18 carbon atoms are also considered. If desired, mixtures of the aforementioned anionic wetting agents can of course also be used.^

It has been shown that the aforementioned additives also remain stable over a longer period of time in the concentrates and thus the content of the peracetic acid concentrate is also maintained constantly. If, on the other hand, soaps or the usual non-ionic wetting agents are used as humectants, sufficient stability is not achieved.

The new storage-stable concentrates of the mentioned functional agents can be used for all purposes, where a moisturizing and oxidizing effect is to be achieved and the disadvantages of the known pure peracids make it difficult or exclude their applicability. The agents also have the advantage that they are suitable for stand disinfection to prevent a secondary germ multiplication on machines, which is particularly the case in the food industry after cleaning. Their amount of H2C>2 also has a long-term effect on most microorganisms.

The pH value of the solution for use is still slightly acidic and the acetic acid residue after disinfection is very small, so that the agents are also suitable for a disinfection where a flush is no longer necessary.

Example 1.

A concentrate for the production of microbicidal agents was produced by mixing together

5 weight? acetic acid,

30 weight? H202,

65 weight? water.

The concentrate is set aside and a sample is taken over a certain period of time to determine the content of H202 and peracetic acid. The results are shown in Table 1 below. For comparison, a further concentrate was prepared which contained 8% by weight of peracetic acid, 8.5% by weight of acetic acid, 1 weight of H202 and 82.5 weight of water. Samples were taken from the mixture after certain periods of time and the content of peracetic acid determined. The results are reproduced in table 2. It is clearly seen that the agents are not stable.

Example 2.

Concentrates of the composition indicated below (product A to C) were prepared from t^C^, acetic acid and water. These concentrates were set aside for a time and then diluted to a 0.05 resp. 0.2 wt?-ig solution. The microbicidal effect in the suspension sample was then determined according to the guidelines of the Deutschen Gesellschaft fur Hygiene und Mikrobiologie (DGHM). The values (eradication times in minutes) are reproduced in the following table 3.

The experiments were repeated after the concentrate had been stored for a longer period of time.

Products (statement by weight?)

Example 3»

Using the suspension sample according to guidelines for DGHM, eradication times of Staphylococcus aureus were determined using mixtures of H2<02 and smaller amounts of acetic acid or propionic acid. The results are reproduced in the following table 4.

Example 4.

Concentrates of 33 wt? H202, 5 weight? acetic acid, 0.5 weight? phosphonic acid, the rest water.

The following phosphonic acids were added to the individual concentrates.

A) Dimethylaminomethanediphosphonic acid.

B) 1-amino-1-phenylmethanediphosphonic acid.

C) Aminotrimethylenephosphonic acid.

D) Aminoacetic acid-N,N-dimethylphosphonic acid.

E) 1-hydroxyethane-1,1-diphosphine.

F) 1-amino-1-cyclohexyl-1,1-diphosphonic acid.

G) 1-N-methylaminoethane-1,1-diphosphonic acid.

H) Ethylenediamine-tetramethylene-phosphonic acid.

In order to obtain a comparative value, no phosphonic acid was added to a further concentrate.

The concentrates were set aside for a time and then diluted to a concentration of 0.1%. Microbicidal activity was carried out in the suspension samples according to the guidelines of the Deutschen Gesellschaft fur Hygiene und Mikrobiologie (DGHM). Staphylococcus aureus and Escheria coli were used as test strains.

The found extinction times in minutes are reproduced in the following table 5.

Example 5.

Storage-stable concentrates of 33% H202, 5% acetic acid, 3% phosphoric acid or 1-hydroxyethane-1,1-diphosphonic acid resp. 2-phosphonobutane-1,2,4-dicarboxylic acid. The concentrates were left for 8 days and then diluted to a use concentration of 0.05%.

The microbicidal effect was determined by means of the germ reduction "D". Thereby, the following test method was used.

0.1 ml of a germ suspension (germ count 108/ml) is added to 10 ml of disinfection solution (or as a control value to 10 ml of water), the mixture is stirred for 5 minutes, 0.1 ml is taken out and placed in 10 ml of deinhibition solution (0.5 ?-ig aqueous thiosulphate solution). From this, the germ count was determined after 15 minutes using the Koch plate method.

The assessment took place according to a formula

D therefore indicates the germ reduction quantitatively in logarithmic form, e.g. D = 1, means that the kiih number was reduced by a third power.

Comparison tests with the addition of phosphoric acid show that the effect of the acidity of the added phosphonic acids is not decisive (see table 6).

IN

Note: The indication "above" before the D value means that all

germs are eradicated.

Example 6.

A concentrate was produced by mixing

5.0 weight? acetic acid,

27.6 weight? H202,

1.0 weight? alkyl-(C12-C1g-sulfonate) as well as

66.4 weight? water.

The concentrate was set aside and at specific intervals a sample was taken to determine the content of H202 and peracetic acid. The results are reproduced in the following table 7« Table 7. Stability of the mixture when an alkyl sulphonate is added.

Practically the same results are obtained when the concentrates instead of 1? alkyl sulfonate contains 1? alkyl sulfate.

Example J .

A concentrate was produced for the production of microbicide by mixing

5 weight? acetic acid,

27.6 weight? H202

1.5 weight? hydroxyethane-1,1-diphosphonic acid,

1.5 weight? alkyl-(C12)-benzenesulfonate as well as

64.4 weight? water.

The concentrate was divided into two halves and stored at temperatures of 20 and 40°C and for certain periods of time, samples were taken to determine the content of H202 peracetic acid. The results are reproduced in the following table 8. It is clearly seen that the concentrates are also stable in the presence of the indicated wetting agent over a longer period of time.

Table 8.

Content of hydrogen peroxide and peracetic acid at 20 and 40°C depending on the time.

Claims (5)

1. Aqueous, storage-stable concentrates of microbicide or oxidizing mixtures based on aliphatic monopercarboxylic acids, characterized in that they contain 0.5-20 wt? peracid with 2 or 3 carbon atoms and/or corresponding aliphatic monocarboxylic acids, 25-40 weight? I^O^and water, as well as possibly phosphonic acid and/or wetting agent. 2. Aqueous, storage-stable concentrates according to claim 1, characterized by a content of 5-10% by weight? peracetic acid and/or acetic acid and a molar excess of H2C>2 in a ratio of at least 2:1, preferably 3:1 to 50:1. 3. Aqueous, storage-stable concentrates according to claims 1 and 2, characterized in that they contain 0.25-10 wt? phosphonic acid or their acidic water-soluble salts. 4. Aqueous, storage-stable concentrates according to claim 3, characterized in that they contain phosphonic acid dimethylaminomethanediphosphonic acid, 1-amino-1-phenylmethanediphosphonic acid, aminotrimethylenephosphonic acid, aminoacetic acid-N-N-dimethylphosphonic acid, or 1-hydroxyethane-1,1-diphosphonic acid, or acidic water-soluble salts or mixtures thereof. 5. Aqueous, storage-stable concentrates according to claims 1-4, characterized in that they contain 0.05-5 wt? anionic wetting agent in the form of alkylbenzene sulphonate, alkyl sulphate and/or alkyl sulphonate.