HRP950474A2 - Process for preparing a disinfectant concentrate - Google Patents

Description

The technical field to which the invention belongs

MKP: A61L 1/00

The invention is from the field of disinfection or sterilization of substances and relates to a procedure for the preparation of a concentrate of a decontaminating agent, which can be mixed with hydrogen peroxide, which creates a decontaminating agent.

Technical problem

Decontamination, especially decontamination of water, foodstuffs and animal feed, as well as equipment, bandages, containers and all kinds of objects, is a general problem, which is equally important in highly civilized nations and in underdeveloped countries. That is why it is not surprising that intensive research has been carried out in this area for decades, and new products and methods are constantly being developed for the non-therapeutic fight against infectious agents.

Technical condition

Among the numerous, from the technical state of the art, known methods of unraveling, we cite the following as an example:

The addition of halogen elements, such as chlorine, bromine or iodine, or preparations containing halogens, is widespread due to the easy production, low cost and availability of the constituent chemicals, as well as due to the considerable depurative effect. The disadvantage is the initial taste and smell of halogen elements, the change in the taste of the preparation to which it is mixed, the overall basic pH, the relatively short duration of the diagnostic effectiveness and the simultaneous sensitivity of the resulting combinations to temperature. In addition, these substances are carcinogenic and mutagenic, cause skin inflammation and are corrosive to various materials.

Ozone and chlorine dioxide combine to form a particularly fast and effective disinfectant, although the resulting combination is potentially explosive. These combined agents can be very dangerous in large doses. Because of this, they show sensitivity to temperature, are prone to carcinogenicity and mutagenicity, and require careful handling and expensive auxiliary equipment. Therefore, they are suitable only for a very narrow area of use.

Copper salts, especially copper sulfate and copper chloride, are recommended as disinfectants that are odorless and do not irritate mucous membranes, etc. These preparations, which provide only an average, short-term disinfection degree and are known as carcinogens and mutagens, can be combined with other substances, including chloride salts.

The procedure, which is common, odorless and without harmful effects on health, is the so-called the Catadyne method; a similar method uses the dispersive effect of silver ions. The second of those two procedures works slowly and has limited usability due to its high cost.

Ultraviolet radiation, which does not introduce foreign substances into the substance to be dissolved, is a reliable source of the dissolving effect. However, the production of ultraviolet radiation requires expensive equipment and considerable costs are commensurate with the large needs for electricity.

Other commercially available products rely heavily on the high dispersive effect of hydrogen peroxide, although such preparations have limited utility due to their instability. These preparations also include them. which combine the well-known exploratory effects of silver with hydrogen peroxide in the form of a stable agent, thus causing the synergism of both exploratory agents.

Description of the solution to the technical problem with practical examples

As a result of the present invention, by means of the new process, products of the type just mentioned can be made, which have significantly improved quality and usability.

The aim of the present invention is to establish a process for the production of a clear, stable concentrate, which can be mixed with hydrogen peroxide to form a cleaning agent, and which contains silver, an inorganic acid and an organic stabilizer.

A further goal of the present invention is to prepare a concentrate of this type, as well as a process for preparing a diagnostic agent from such a concentrate.

The present invention relates to a stable concentrate, which contains a silver compound, an inorganic acid and an organic stabilizer, and to the process of its preparation and its use. The concentrate is intended for mixing with hydrogen peroxide in order to create a cleaning agent.

In terms of the proposed invention, a clear stable concentrate, which can be mixed with hydrogen peroxide to obtain a cleaning agent, is prepared by mixing an aqueous inorganic acid solution with a pH less than or equal to 1.6 in deionized water between 50 and 60°C with a silver salt or a silver salt complex. in an amount of about 95 to 105 g Ag per liter, whereby the amount of acid present is always equimolar to the silver salt or silver salt complex present; by cooling the thus obtained aqueous acid solution to between 25 and 30°C and adding an organo-acid stabilizer and in the given example gelatin.

Suitable silver compounds include silver nitrate (AgNO3), silver sulfate (Ag2SO4), silver chloride (AgCl), and the sodium silver chloride complex of the formula AgNaCl2. Further suitable silver compounds are silver benzoate (C6H5-CO2Ag), silver carbonate (Ag2CO3), silver fluoride (AgF), silver(1) oxide (Ag2O) and silver(II) oxide (AgO). One or more silver compounds are added in such quantities that the concentrate contains 100 g ± 5 % of silver per liter of concentrate.

As an alternative to using silver salts or silver salt complexes, you can use colloidal silver. This procedure is carried out by adjusting the aqueous solution containing about 13 g of colloidal silver per liter to pH ≤ 1.6 using an inorganic acid, heating the solution to 50 to 60°C, mixing it with a solution of an organic stabilizer in distilled or completely demineralized water. at approximately the same temperature, in such an amount that the concentration of silver is about 9.5 to 10.5 g Ag per liter, an amount of inorganic acid used to adjust oH is added to the mixture at a temperature of 20 to 25°C, so that the total amount of inorganic acid is always equimolar to the amount present of silver, gelatin is added to the solution in the given example and homogenized.

A suitable colloidal silver compound, obtainable from Degusse AG, Zurich, contains 13 g of silver per liter in an aqueous solution of 5% by weight polyhydroxyl monocarboxylic acid.

Tartaric acid and/or citric acid are suitable stabilizers for use in combination with the silver component(s). These acids should be added in an amount of approximately 50 g of one or the other per liter of concentrate.

Further organic acids suitable as stabilizers, which should be used in stoichiometric amounts equivalent to those indicated for tartaric and/or citric acid, include acetamidacrylic acid (H2C=C(NHCOCH3)CO2H), acetamidohexanoic acid (CH3CONH(CH2)5CO2H), acetylbutyric acid ( CH3CO(CH2)3CO2H), acrylic acid (H2C=CHCO2H), adipic acid (HO2C(CH2)CO2H). maleic acid (HO2CCH2CH(OH)CO2H). ethoxyacetic acid (C2H5OCH2CO2H), formic acid (HCO2H), succinic acid (HO2CCH2CH2CO2H), butyric acid (CH3CH2CH2CO2H), hexanoic acid (CH3(CH)2CO2H), hippuric acid (C6H5CONHCH2CO2H), malonic acid (HO2CCH2CO2H), methanesulfonic acid (CH3SO3H ), lactic acid (CH3CH(OH)CO2H), caprylic acid (CH3(CH2)6CO2H), oleic acid (CH3(CH2)7CO2H), oxalic acid (H02CCO2H), salicylic acid (HOC6H4CO2H) and valeric acid (CH3(CH2 )3CO2C2H5). In fact, each of the above organic acids is suitable for use with both silver salt and colloidal silver preparations, and they are particularly suitable for use with various silver salts. Tartaric and/or citric acid are preferred for use with silver salt compounds.

In fact, each of the above-mentioned organic acid stabilizers is suitable for use in combination with colloidal silver, and for use in quantities of about 100 g pp . liters of concentrate are the following: acetonedicarboxylic acid (HO2CCH2COCH2CO2H), acetoxybenzoic acid (CH3CO2C8H4CO2H), ethoxybenzoic acid (C2H5OC6H4CO2H), ethylbenzoic acid (C2H5C6H4CO2H), aminobenzoic acid (H2NC6H4CO2H), benzoic acid (C6H5CO2H), bromobenzoic acid (BrC6H4CO2H), bromsalicylic acid acid (BrC6H3-2-(OH)CO2H), fluorosulfonyl-benzoic acid (FSO2C6H4CO2H), hydroxybenzoic acid (HOC6H4CO2H) and phthalic acid (C6H4-1.2-(CO2H)2).

In fact, they are advantageous for use with colloidal silver, whereby stabilizers from various benzoic acids are most advantageous, and these organic acid stabilizers can also be used with the above-mentioned silver salts.

An inorganic acid is used to reduce the pH of the preparation containing silver and stabilizer. A 75% aqueous solution of phosphoric acid, a 65% aqueous solution of nitric acid or a 69% aqueous solution of sulfuric acid is generally used. Hydrobromic acid, hydrochloric acid or boric acid are equally suitable. It is recommended to use the same acid that is later applied to stabilize the commercial hydrogen peroxide that will be mixed with the concentrate. The acid is used as a pH regulator, and in particular acts as an additional stabilizer for the silver compound and for the ready-to-use product. For this reason, acid should be added in excess of the amount needed to adjust the pH. The total amount of acid in the finished concentrate is at least equimolar to the amount of silver present, and preferably in excess, for example 100 g of acid per liter of concentrate.

If the concentrates, after mixing with hydrogen peroxide and obtaining a ready-to-use disinfectant, will be exposed to UV radiation for a long time, such as sunlight, etc., such as for example in an open swimming pool, it is recommended to add gelatin to the concentrate at a temperature of at least 20° before homogenization C; in general, this additive amounts to about 20 g per liter of concentrate, and it protects silver against the effects of UV radiation.

It is convenient to prepare the concentrate at a temperature of at least 20°C and under red light, until the pouring is finished, for example in containers made of colored glass or artificial substances without pigments.

The durability of the concentrate in terms of the present invention is unlimited, even at tropical temperatures, and in contrast to well-known products, it remains a watery, clear, colorless, homogeneous liquid, which does not thicken even after standing for a long time. This permanent homogeneity of the product is a considerable advantage, because it enables possible future dosing of concentrate rations without repeated homogenization, which was necessary until we invented the present invention.

The concentrate obtained with silver salt or silver salt complex can be mixed with 35 to 50 wt.% hydrogen peroxide (in water) in a volume ratio of 1:99 to 1:199. If a concentrate containing colloidal silver is used in the quantities mentioned above, mixing with hydrogen peroxide is carried out in ratios from 1:9.9 to 1:19.9. The resulting agent, ready for use, has an Ag concentration between 0.05 and 0.1 wt.%. At a ratio above 1:199, i.e. above 1:19.9, the product represents the significance of silver/hydrogen peroxide synergism. If the ratio is less than 1.99 or 1:9.9, there is a possibility that silver will precipitate out of the mixture. A product that exists within the indicated limits is stable when stored for at least 2 years.

The concentration of added hydrogen peroxide can be for certain uses up to 30 wt.%, although the product decomposes more easily and the degree of dissolution is lower than that obtained by using 50 wt.% hydrogen peroxide.

Due to the stable homogeneity of the concentrate, repeated homogenization of the concentrate before mixing with hydrogen peroxide is not necessary.

Diagnostic agents of this type, mixed with hydrogen peroxide and ready for use, can be packed in the usual containers for transport and sale, which should be equipped with a safety device to reduce any excessive gas pressure, for example a safety valve. Chemical agents can remain in such containers at a temperature between 4 and 25°C for about 2 years without any danger. Longer storage at higher temperatures is not recommended, because carbon peroxide tends to release gas.

The disinfectants we invented are suitable for sterilizing water, foodstuffs and animal feed, stationary surfaces, etc. The concentrate is added in very small amounts, usually around 10 to 75 ppm, if it is added as a so-called "material loosening agent" with substances such as bathing water, drinking water, foodstuffs, cooking water, etc., or is used as a 0.1 to 2 wt.% solution for loosening surfaces. Products or objects disinfected with these new disinfectants do not show any changes in smell, taste or shape at all, are non-toxic, do not cause skin inflammations or any health hazards, and are completely inert compared to ordinary materials such as concrete, wood, stone, glass, metals, porcelain, ceramics, plastics, fabrics, etc.

The agent ready for use has a pH of about 2, and if necessary, it should be adjusted to that pH, primarily by adding an additional amount of inorganic acid that is already present in the preparation. In contrast to chlorine, the agent itself does not change the pH of the product to which it is added, primarily because it is necessary to use only small amounts. It can also be used in a wider temperature range than chlorine, namely between 0 and 95°C, and the cleaning effect increases with increasing temperature.

In the concentrations mentioned above, the new agents are largely capable of destroying pathogenic germs. Among other things, they destroy gram-positive and gram-negative bacteria, bacteriophages, viruses, etc., such as E. coli, Proteus mirabilis, Staphylococcus aureus, Streptococcus faecalis, Pseudomonas aeruginosa, Mycobacterium tuberculosis, Candida albicans, etc.

The new means are particularly suitable for sterilization in the food industry and the animal feed industry, including the canning industry, preservation of fresh products, fish processing, for partial or complete preservation and for degumming in slaughterhouses, in the beverage industry and in breweries, for the preparation of mineral water, in the production of wine and spirits, in the production of fruit and vegetable juices, for decanting jars and crates and water to be added to the concentrate, for decanting water for drinking water in springs or in storage vessels, in swimming pools and in hot springs, as and in dairies, in agriculture, in the chemical and pharmaceutical industry, in laboratories and in hospitals, to prevent diseases, etc.

In the following examples, all percentages refer to mass, unless otherwise stated.

Examples

At a temperature above 20°C and under a red light bulb, we slowly added and mixed in 0.8 l of completely demineralized water 75% phosphoric acid, until a pH equal to or lower than 1.6 was reached. The mixture was stirred and heated to 55°C and 157.5 g of silver nitrate was added while stirring. We continued mixing until complete homogenization occurred.

We let the solution cool down to around 25 to 30°C; then we slowly mixed in portions of 75% phosphoric acid, so that the total amount of phosphoric acid (75%) in the solution was 100 g. We then left the mixture to reach room temperature (20 to 25°C) without stirring, and after to that we added 50 g of tartaric acid.

The obtained mixture was then supplemented to a total volume of 1 l by adding distilled or fully deionized water, adjusted the pH to a value equal to or less than 1.6 using the same inorganic acid, if necessary, and then homogenized, in this particular example after adding 20 g of gelatin, which we mixed at room temperature that exceeded 20°C. We obtained a crystal clear solution. The same result would be achieved if, instead of phosphoric acid, 65% nitric acid or 37% hydrochloric acid or 69% sulfuric acid were added to a total addition of 100 g of acid, and/or if silver nitrate were replaced with 145 g of silver sulfate or 137 g of silver chloride or 187.2 g of sodium/silver chloride complex (AgNaCI2), and/or if instead of tartaric acid, 50 g of citric acid or 50 g of a mixture of citric acid and tartaric acid were used.

Example II

To prepare 11 l of concentrate, we mixed 850 g of sodium or potassium benzoate slowly and in portions at about 55°C in 1 l of distilled water. We then stopped the mixing and kept the mixture at 55°C.

In a certain container, we slowly and in portions added 8350 g of colloidal silver solution (13 g of Ag per liter in a 5% aqueous solution of polyhydroxyl carboxylic acid from the company Degussa AG), which achieved a pH of 1.6 or lower, and we heated the mixture to 55°C.

To this mixture, we added the entire aqueous solution of sodium or potassium benzoate prepared above, and homogenized the mixture well. Then we let it cool to room temperature (20 to 25°C) without stirring. We then added to the cooled mixture with stirring such an amount of the same inorganic acid to adjust the pH, that the total amount was 800 g; the addition was done slowly and in portions with stirring. This caused the mixture to homogenize well. By adding 200 g of gelatin at at least 20°C and re-homogenizing, we obtained a concentrate that was completely stable in relation to any sedimentation or degradation, even under ultraviolet irradiation of water diluted with the final product, for example in swimming pools.

Example III

We mixed 5 l of the concentrate obtained in accordance with example I at room temperature under a red light bulb and in a retort made of stainless steel, in a volume ratio of 1:99 with 50 vol.% H2O2, until it was homogenized. When the formation of bubbles stopped, we stored the product. This product was particularly suitable for long-term desalination, preferably at high temperatures, for example as an additive for hot springs, recycled water for water purification devices, etc., preferably in a concentration of 40 to 75 ppm.

Example IV

We processed 11 l of the concentrate obtained in accordance with example II into the final product in accordance with example III, in a ratio of 1:19.9 with 50 vol.% H2O2. The resulting product is suitable, for example, for decontamination of drinking water in a concentration of 10 to 34 ppm, and for decontamination of surfaces in a 0.1 to 2% solution.

In fact, we have described the invention in relation to specific methods and materials, with the aim that the invention be limited as much as stated in the attached patent claims.

The best way to make economic use of the invention

At above 20° and under a red lamp, 75% phosphoric acid is slowly mixed in 0.8 l of completely demineralized water, until a pH lower than or equal to 1.6 is reached. The mixture is stirred and heated to 55°C, and with stirring, 157.5 g of silver nitrate is added. Continue mixing until complete homogenization.

The solution is left to cool down to around 25 to 30°C. Then, 75% phosphoric acid is slowly mixed in portions so that the total amount of phosphoric acid (75%) in the solution is 100 g. The mixture is then left to stand without stirring until it reaches room temperature (20 to 25°), and then added 50 g of tartaric acid.

The resulting mixture is then supplemented with a total volume of 1 l by adding distilled or fully deionized water, if necessary, the pH is adjusted to a value less than or equal to 1.6 using the same inorganic acid and then homogenized, in this particular example after the addition of 20 g of gelatin, which is mixed at temperature exceeding 20°C. A crystal clear solution is obtained.

Claims (8)

1. The procedure for the preparation of a concentrate of a cleaning agent which is clear, indefinitely stable, and when mixed with hydrogen peroxide forms a cleaning agent, and contains silver, an inorganic acid and an organic stabilizer, according to version I, indicated by the fact that distilled or completely demineralized water, which we have adjusted the pH to a value less than or equal to 1.6 using an inorganic acid, at a temperature of 50 to 60°C, mix with silver salt or its complex in the amount of about 95 to 105 g Ag per liter of water, mix the mixture at 25 to 30°C with the acid used to adjust the pH, in such a quantity that the total amount of this acid is always equimolar to the silver component present, the resulting solution is mixed at 20 to 25°C with an organic stabilizer and, in the example mentioned, homogenized after the addition of gelatin. 2. The procedure according to claim 1 according to version II, characterized in that the aqueous solution containing about 13 g of colloidal silver per liter is adjusted to pH ≤ 1.6 using an inorganic acid, the solution is heated to 50 to 60°C. mix with a solution of an organic stabilizer in distilled or completely demineralized water of approximately the same temperature in such a quantity that the silver concentration is approximately 9.5 to 10.5 g of Ag per liter of water, add to the mixture at a temperature of 20 to 25°C the same amount of inorganic acid used for pH adjustment , so that the total amount of inorganic acid is always equimolar to the amount of silver present, gelatin is added to the solution in the given example and homogenized. 3. The method according to claims 1 or 2, indicated by the fact that phosphoric, nitric or sulfuric acid is used as an inorganic acid, preferably in an amount of 100 g per liter of water. 4. The method according to claim 1, characterized in that we use silver nitrate, sulfate or chloride, or a sodium silver chloride complex as a silver salt, and tartaric and/or citric acid as an organic stabilizer, preferably each in an amount of about 50 g per liter of water . 5. The method according to claim 2, indicated by adding colloidal silver to an aqueous solution containing about 5% by weight of polyhydroxymonocarboxylic acid, and using alkaline benzoate as an organic stabilizer. 6. The method according to one of claims 1 to 5, characterized in that the mixing is always performed at 20°C. 7. The procedure for preparing a cleaning agent, indicated by mixing at a temperature of at least 20°C and in the given example under a red light bulb, the concentrate prepared in accordance with the procedure according to claim 1, with 35 to 50 vol.% hydrogen peroxide in the ratio of concentrate and of hydrogen peroxide 1:99 and 1:199, whereby the resulting preparation has an Ag concentration between 0.05 and 0.1 wt.%. 8. Procedure for the preparation of a cleaning agent, indicated by mixing at a temperature of at least 20°C and in the given example under a red light bulb, the concentrate prepared in accordance with the procedure according to claim 1, with 35 to 50 vol.% hydrogen peroxide in the ratio of the concentrate and hydrogen peroxide 1:9.9 and 1:19.9, whereby the resulting preparation has an Ag concentration between 0.05 and 0.1 wt.%.