Process for preparing a disinfectant

• US 4,915,955 A
• Filed: 09/05/1986
• Issued: 04/10/1990
• Est. Priority Date: 04/22/1986
• Status: Expired due to Term

• Current Assignee: S A N O S I L AG General Wille Strasse
• Original Assignee: Sanosil AG
• Inventors: Gomori, Janos
• Primary Examiner(s): Robinson, Douglas W.
• Assistant Examiner(s): Weddington, Kevin E.
• Application Number:
  US06/904,055
• Time in Patent Office: 1,313 Days
• Field of Search: 424/132, 424/128, 424/130, 424/616, 424/618, 514/495
• US Class Current: 424/616
• CPC Class Codes: A01N 2300/00 Combinations or mixtures of active ingredients covered by classes A01N27/00 - A01N65/48 with other active or formulation relevant ingredients, e.g. specific carrier materials or surfactants, covered by classes A01N25/00 - A01N65/48
• CPC Class Codes: A01N 25/22 containing ingredients stabilising the active ingredients
• CPC Class Codes: A01N 37/10 Aromatic or araliphatic carboxylic acids, or thio analogues thereof; Derivatives thereof
• CPC Class Codes: A01N 37/36 containing at least one carboxylic group or a thio analogue, or a derivative thereof, and a singly bound oxygen or sulfur atom attached to the same carbon skeleton, this oxygen or sulfur atom not being a member of a carboxylic group or of a thio analogue, or of a derivative thereof, e.g. hydroxy-carboxylic acids
• CPC Class Codes: A01N 59/00 Biocides, pest repellants or attractants, or plant growth regulators containing elements or inorganic compounds
• CPC Class Codes: A01N 59/16 Heavy metals; Compounds thereof
• CPC Class Codes: C02F 1/505 by oligodynamic treatment
• CPC Class Codes: C02F 1/722 Oxidation by peroxides

Abstract

A concentrate with an unlimited shelf-life, which can be mixed with hydrogen peroxide at a ratio of 1:99 to 1:199 to become an effective disinfectant, is obtained when a viscous solution of inorganic acid, with a pH less than or equal to 1.6, is mixed with a silver salt compound or a colloidal silver compound at 50° to 60° C. The mixture is further combined at room temperature with other inorganic acid(s) to reach a total of 100 g inorganic acid(s) per liter of water; at room temperature, an organic acid stabilizer is added and the mixture is homogenized. The concentrate, during storage, remains homogeneous and crystal-clear.

Claims

1. A process for preparing a storage stable, clear concentrate of unlimited durability which, upon admixture with hydrogen peroxide, forms a disinfectant, comprising:

(a) admixing an inorganic acid with water, said water being selected from the group consisting of distilled water and fully desalted water, to yield aqueous inorganic acid having a pH less than or equal to 1.6;

(b) admixing said aqueous acid at a temperature between 50 and 60°

C. with a silver composition, selected from the group consisting of silver salts and silver salt complexes, in an amount which yields 95-105 g Ag per liter of the final concentrate;

(c) cooling the resultant admixture to between 25 and 30°

C., and adding such an amount of the same acid as was used for adjusting the pH of the water whereby the total amount of said acid is at least equimolar with the amount of silver present;

(d) adding to said admixture an organic acid stabilizer, and optional gelatin, at 20 to 25°

C.; and

(e) homogenizing the obtained mixture.

2. The process according to claim 1 wherein the inorganic acid is selected from the group consisting of phosphoric acid, nitric acid and sulfuric acid, preferably in an amount of 100 g per liter water.

3. The process according to claim 1 wherein the silver compound added in step (b) is selected from the group consisting of silver nitrate, silver sulfate, silver chloride, sodium/silver chloride complex, silver benzoate, silver carbonate, silver fluoride, silver oxide and silver oxide, in an amount which yields approximately 95-105 g Ag per liter of the final concentrate;

and the organic acid added in step (d) is selected from the group consisting of tartaric acid, citric acid and compositions containing both tartaric acid and citric acid, preferably in an amount of 100 g per liter water.

4. The process for the manufacture of a disinfectant, comprising admixing, at a temperature of at least 20°

C. and optionally under red light, a concentrate, prepared in accordance with the process of one of claims 1, 2, or 3, with 35-50% by volume aqueous hydrogen peroxide at a ratio between 1;

99 and 1;

199 concentrate to aqueous hydrogen peroxide, whereby the ratio is chosen to yield a resultant composition having an Ag concentration between 0.05 and 0.1% by weight.

7. The process according to any of claims 1, 5, 2, 3 or 6 wherein said inorganic acid is mixed with said water at a temperature of at least 20°

C.

8. The product prepared in accordance with the process of any of claims 1, 5, 2, 3, or 6.

10. The product prepared in accordance with the process of claim 7.

5. A process for preparing a storage stable, clear concentrate of unlimited durability which, upon admixture with hydrogen peroxide, forms a disinfectant, comprising:

(a) admixing an inorganic acid with an aqueous solution containing colloidal silver solution in 5% aqueous polyhydroxymonocarboxylic acid, to yield a solution having a pH less than or equal to 1.6;

(b) heating said aqueous solution to between 50 and 60°

C. and adding thereto a solution of an organic stabilizer in distilled or fully desalted water having about the same temperature in an amount which yields approximately 9.5-10.5 g Ag per liter of the final concentrate;

(c) cooling the admixture to 20°

to 25°

C.;

(d) adding thereto such an amount of the same inorganic acid as was used for adjusting the pH that the total amount of inorganic acid is at least equimolar with the amount of silver present;

(e) optionally adding gelatin; and

(f) homogenizing the admixture.

6. The process according to claim 5 wherein the colloidal silver is added in the form of an aqueous solution which further contains about 5% by weight of polyhydroxyl carboxylic acid, and wherein a benzoic acid stabilizer, and optional gelatin, are added.

9. The process according to claim 5 wherein the inorganic acid is selected from the group consisting of phosphoric acid, nitric acid and sulfuric acid, preferably in an amount of 100 g per liter water.

11. The process for the manufacture of a disinfectant, comprising admixing, at a temperature of at least 20°

C. and optionally under red light, a concentrate, prepared in accordance with the process of one of claims 5, 6 or 7, with 35-50% by volume aqueous hydrogen peroxide at a ratio between 1;

9.9 and 1;

19.9 concentrate to aqueous hydrogen peroxide, whereby the ratio is chosen to yield a resultant composition having an Ag concentration between 0.05 and 0.1% by weight.

12. The disinfectant product obtained in accordance with the process of either of claims 4 or 11.