Aqueous hydrogen peroxide solution comprising a specific stabilizer

Abstract

An aqueous hydrogen peroxide solution comprises a stabilizer chosen from the family of substituted or unsubstituted aminopolycarboxylic acids (APCA) or salts thereof. The solution may be used for disinfecting a packaging.

Claims

1. An aqueous hydrogen peroxide solution consisting of: from 20 to 98%, by weight of the solution, of hydrogen peroxide, from 0.5 to 7 mg/kg, by weight of the solution, of a stabilizer, wherein the stabilizer is chosen from the family of substituted or unsubstituted aminopolycarboxylic acids (APCA), or salts thereof, of general formula: ##STR00003## in which R and R are selected from group consisting of the following functional groups: C1 to C3 alkyls, and C1 to C3 carboxylic acids, and the remainder to 100% of water.

2. The aqueous solution of claim 1, comprising from 20 to 75%, by weight of the solution, of hydrogen peroxide.

3. The aqueous solution of claim 1, wherein one of R or R consists of a methyl group and the other of R or R consists of a substituted or unsubstituted methanoic acid group or a salt thereof.

4. The aqueous solution of claim 1, wherein one of R or R consists of a substituted or unsubstituted methanoic acid group or a salt thereof, and the other of R or R consists of a substituted or unsubstituted propanoic acid group or a salt thereof.

5. The aqueous solution of claim 1, wherein the solution has a conductivity of 10 to 100 S/cm.

6. The aqueous solution of claim 1, wherein the solution has a maximum acidity of 1 mmol/kg.

7. The aqueous solution of claim 1, wherein the solution has a content of dry residue at 110 C. of not more than 7 mg/kg.

8. The aqueous solution of claim 1, wherein the loss of titer of said solution, measured according to the CEFIC-H.sub.2O.sub.2-AM-7161 method, is less than or equal to 5% relative to the initial concentration of hydrogen peroxide.

9. A process for disinfecting/sterilizing a product, comprising placing the product in contact with the aqueous solution of claim 1.

10. The process of claim 9, wherein the placing in contact is performed by spraying or vaporizing said solution onto said product.

Description

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

(1) The invention is now described in greater detail and in a nonlimiting manner in the description that follows.

(2) To manufacture an aqueous hydrogen peroxide solution according to the invention, hydrogen peroxide and the stabilizer according to the invention may be placed in contact by simple mixing. The stabilizer in solid form may in particular be dissolved in an aqueous hydrogen peroxide solution. The manufacture of hydrogen peroxide is a technique that is well known to those skilled in the art and does not constitute the subject of the present invention.

(3) The present invention also relates to a process for manufacturing an aqueous hydrogen peroxide solution according to the present invention, comprising a step a) of mixing: 20 to 98%, preferably from 20 to 75%, preferably from 20% to 65%, preferably from 20 to 50% and more preferentially from 22% to 38%, by weight of the solution, of hydrogen peroxide, and 0.5 to 7 mg/kg, by weight of the solution, of a stabilizer as defined above.

(4) Preferably, the mixing step allows dissolution of said stabilizer in the aqueous hydrogen peroxide solution.

(5) Preferably, said process also comprises a step a), prior to step a), of purifying said aqueous solution comprising hydrogen peroxide.

(6) Parameters Measured and Methods Used

(7) When reference is made to a standard method, the implementation conditions are those described in this method, unless an adaptation is explicitly mentioned.

(8) The hydrogen peroxide titer in the disinfecting composition is measured according to the CEFIC-H.sub.2O.sub.2-AM-7157 method known to those skilled in the art. This method consists in titrating the hydrogen peroxide in an aqueous sulfuric acid solution using a standard volumetric solution of potassium permanganate.

(9) The stability of the hydrogen peroxide is evaluated via the CEFIC-H.sub.2O.sub.2-AM-7161 method. This method consists in determining the percentage loss of hydrogen peroxide by measuring the hydrogen peroxide content before and after heating it at 96 C. for 16 hours.

(10) The content of evaporation dry residues of the disinfecting composition is measured at 110 C. via the following gravimetric method:

(11) 1A platinum capsule with a volume in the region of 300-350 mL (milliliters) is placed in a muffle furnace at 900 C. for one hour. The capsule is cooled in a desiccator and is weighed on a precision balance to an accuracy of 0.0001 g. This mass is noted as Y (in g).
2An approximately 500 mL beaker is weighed to an accuracy of 0.0001 g (grams) and its mass is noted. About 300 g are added to this beaker. The beaker is weighed again to an accuracy of 0.0001 g. W1 (in grams) is noted as the difference between the mass of the beaker before and after the addition of the sample specimen.
3The sample is gradually transferred into the platinum evaporation capsule (immersed in cold water) by means of a peristaltic pump making it possible to obtain a feed rate of about 75 g per hour. Once the test specimen has been transferred and the hydrogen peroxide has completely decomposed, the sample is evaporated to dryness on a water bath. Operations 2 and 3 are repeated twice so as to obtain a cumulative of sample specimens of between 750 and 1000 g. This makes it possible to obtain better precision on the determination of the dry residue.
4The platinum capsule is then placed in a furnace at 110 C. for at least 1 hour.
5The capsule is cooled in a desiccator for 30 minutes and is then weighed to an accuracy of 0.0001 g. This weight Z (in g) is noted.
6The content of dry residue is calculated with the aid of the formula:
Dry residue at 110 C. (in g/kg)=1000(ZY)/(W1+W2+W3)
in which
Z (in g) represents the mass of the capsule containing the dry residue after evaporation,
Y (in g) represents the mass of the empty capsule,
W1, W2 and W3 (in g) represent the masses of the successive sample specimens.

EXAMPLES

(12) The following examples illustrate the invention without limiting it. In particular, they reproduce the behavior of aqueous hydrogen peroxide solution is under working conditions, i.e. those of an aseptic packaging machine for sterilizing a packaging.

(13) In all the examples presented below, it is considered that the amount of hydrogen peroxide in the aqueous solution is 35%. It should be noted that the stability is tested here for the pure aqueous solution and in the presence of a metallic contamination at low concentration (1 mg/liter of iron). In this last test, it will be accepted that the maximum threshold value is set at 20% in order to be in accordance with the invention.

(14) The results for the amounts of dry residues include both those originating from the peroxide (i.e. derived essentially from its manufacture) and also those originating from the stabilizer(s), the latter residues being the only ones that the present invention intends to remove, or to reduce very significantly, from the (final) aqueous hydrogen peroxide solution.

(15) The following starting materials are used:

Example 1

(16) The aqueous solution of Example 1 comprises 0.1 mg/kg of methylglycinediacetic acid (or a salt thereof).

Example 2

(17) The aqueous solution of Example 2 comprises 1.1 mg/kg of methylglycinediacetic acid (or a salt thereof).

Example 3

(18) The aqueous solution of Example 3 comprises 3.3 mg/kg of methylglycinediacetic acid (or a salt thereof).

Example 4

(19) The aqueous solution of Example 4 comprises 1.1 mg/kg of diacetic acid glutamate (or a salt thereof).

Example 5

(20) (Comparative)

(21) The aqueous solution of Example 5 is a grade of hydrogen peroxide currently marketed (Valsterane 35S) available for applications for the disinfection of food packagings by spraying, comprising 4 mg/kg of a phosphonic acid as stabilizer.

Example 6

(22) (Comparative)

(23) The aqueous solution of Example 6 is a grade of hydrogen peroxide currently marketed (Valsterane 35SB) available for applications for the disinfection of food packagings by spraying, comprising 16 mg/kg of a phosphonic acid as stabilizer.

Example 7

(24) (Comparative)

(25) The aqueous solution of Example 7 comprises 1.1 mg/kg of cyclohexanediaminotetraacetic acid (or a salt thereof).

Example 8

(26) (Comparative)

(27) The aqueous solution of Example 8 comprises 1.1 mg/kg of dipicolinic acid (or a salt thereof).

Example 9

(28) (Comparative)

(29) The aqueous solution of Example 9 comprises 1.1 mg/kg of diethylenetriaminepentaacetic acid (or a salt thereof).

Example 10

(30) (in Accordance with the Invention, the Most Preferred Range)

(31) The aqueous solution of Example 10 comprises 2.3 mg/kg of methylglycinediacetic acid (or a salt thereof).

Example 11

(32) (in Accordance with the Invention, Preferred Range)

(33) The aqueous solution of Example 11 comprises 4 mg/kg of methylglycinediacetic acid (or a salt thereof).

Example 12

(34) (in Accordance with the Invention)

(35) The aqueous solution of Example 12 comprises 6 mg/kg of methylglycinediacetic acid (or a salt thereof).

(36) The results obtained are indicated in the table below:

(37) TABLE-US-00001 Dry residue at Stability* under Stability* 110 C. contamination conditions Ex. (16 h/96 C.) (mg/kg) (1 mg/L of Fe) 1 2.7 4 20 2 1.1 4.3 10 3 0.8 6.5 8 4 1.4 4.3 13 5 1 9 25 6 0.8 18 10 7 2 4.3 30 8 2.5 4.3 35 9 2 4.3 30 10 1 6 10 11 0.7 6.8 7 12 0.6 7 6 *expressed as a relative percentage loss of H.sub.2O.sub.2 titer

(38) It is thus found that only the compositions according to the invention, in particular compositions 2 to 4, have excellent stability over time (with or without contamination) and an extremely low amount of dry residues.