JPH10101310A - Stabilizing method of acid hydrogen peroxide solution containing iron - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize an acid hydrogen peroxide soln. containing iron by adding phenylglycol ethers and cyclic satd. alcohols into the acid hydrogen peroxide soln. containing iron. SOLUTION: An acid hydrogen peroxide soln. containing iron is stability by adding as a stabilizer, at least one kind of compd. selected from phenyloglycol ethers and cyclic satd. alcohols by 0.01 to 1.0g/l. The acid hydrogen peroxide soln. is, for example, such a soln. that is used as a chemical treating liquid form pickling or etching of iron or iron alloy and that contains >=20g/l hydrogen peroxide, >=50g/l of at least one of inorg. acid such as hydrochloric acid, hydrofluoric acid, sulfuric acid and nitric acid, and contains iron due to elusion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for stabilizing an aqueous solution of acidic hydrogen peroxide containing iron.

[0002]

2. Description of the Related Art An aqueous solution of acidic hydrogen peroxide comprising an inorganic acid such as hydrochloric acid, hydrofluoric acid, sulfuric acid, nitric acid, phosphoric acid and hydrogen peroxide is used for pickling and etching of stainless steel and other iron and iron alloys. Conventionally, it has been widely used as a chemical treatment solution. For example, Japanese Patent Publication No. S41-18934 describes a treatment solution composed of perchlorate, hydrogen peroxide, hydrofluoric acid or a salt thereof. Japanese Patent Publication No. 39-18303 describes a treatment solution having a composition of hydrogen peroxide and oxalic acid, and Japanese Patent Publication No. 47-35652 describes a chemically treated armpit composed of hydrogen peroxide, hydrofluoric acid, hydrochloric acid, an organic solvent and a surfactant. ing. These treatment liquids have excellent treatment capacity immediately after bathing, but when used repeatedly, heavy metal ions such as iron ions eluted from the object to be treated accumulate and the decomposition of hydrogen peroxide increases. There is a disadvantage that. As a result, there are various problems, such as an increase in the amount of used hydrogen peroxide, which is uneconomical, and it is difficult to control the concentration of hydrogen peroxide in the aqueous solution. Various means for solving these problems have been studied in the past, including saturated aliphatic alcohols in US Pat. No. 3,597,290, glycols in Japanese Patent Publication No. 54-2607,
JP-B-54-42850 describes quaternary ammonium salts as stabilizers for hydrogen peroxide in an aqueous solution of acidic hydrogen peroxide. In addition, it has been reported that amines and the like are effective as a hydrogen peroxide stabilizer in an acidic aqueous hydrogen peroxide solution containing heavy metal ions. However, these stabilizers are effective in a region where the concentration of heavy metal ions is as low as about 0.1 g / l, but cannot provide a sufficient effect in a region where the concentration of heavy metal ions is as high as 10 g / l.
In general, a high concentration of / l is required.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a means capable of more effectively stabilizing an aqueous solution of acidic hydrogen peroxide containing iron.

[0004]

According to the present invention, there is provided an acidic hydrogen peroxide solution containing at least one compound selected from phenyl glycol ethers and cyclic saturated alcohols in an aqueous solution of acidic hydrogen peroxide containing iron. This is a method for stabilizing an aqueous hydrogen solution. The acidic hydrogen peroxide aqueous solution containing iron to be used for stabilization in the present invention may be any of those conventionally used as a chemical treatment solution for pickling and etching iron and iron alloys. Is 20g of hydrogen peroxide
/ L or more, an aqueous solution containing 50 g / l or more of at least one of inorganic acids such as hydrochloric acid, hydrofluoric acid, sulfuric acid and nitric acid and containing iron derived from elution or the like therein is usually used.

As the phenyl glycol ethers added as a stabilizer, compounds represented by the general formula (I) are preferably used. General formula _{(I) C 6 H 5 O} (CH 2 CH 2 O) n H (n is an integer of 1-2) More specifically ethylene glycol monophenyl ether and diethylene glycol monophenyl ether are preferably used.

The cyclic saturated alcohol to be added as a stabilizer is preferably a cyclic saturated alcohol having 5 to 7 ring carbon atoms. A substituent such as an alkyl group may be bonded to the ring constituting carbon. The alkyl substituent preferably has 1 to 4 carbon atoms. Accordingly, cycloalkyl alcohols having 5 to 7 carbon atoms are preferred, and specifically, cyclopentanol, cyclohexanol and cycloheptanol are particularly preferred. The addition amount of these stabilizers is effective if added to the processing solution at a concentration of 0.01 g / l or more, and it is more effective to increase the addition amount, but increases even if added at 10 g / l or more. No effect is observed, but rather disadvantageous economically.
Therefore, the amount of the stabilizer is usually 0.01 to 1.0 g /
l, more preferably 0.05 to 0.1 g / l.

The above stabilizer used in the present invention exhibits a remarkable hydrogen peroxide stabilizing effect even when used alone, but when two or more stabilizers are used in combination, at least one phenyl glycol ether and at least one When a cyclic saturated alcohol is used in combination, a high stabilizing effect exceeding that of a single use is exhibited if the total amount of the stabilizer added is the same as when used alone. This is thought to be due to the synergistic effect of using two or more stabilizers in combination. As a method of adding the stabilizer, the method of adding at the time of building bath is the most effective.However, it may be added at the time when the iron ion concentration increases due to repeated use. Each time hydrogen peroxide is replenished, it is possible to add an amount of stabilizer according to the amount of hydrogen peroxide to be added.

[0008]

【Example】

Example 1 Hydrochloric acid 20 g / l, hydrofluoric acid 40 g / l, iron 10 g / l, and ethylene glycol monophenyl ether 0.01 g /
Hydrogen peroxide was added to the solution containing 1 at a concentration of 20 g / l and left at 50 ° C. for 5 hours, during which the stability of hydrogen peroxide was measured. The stability of hydrogen peroxide was calculated by the following calculation.

[0009]

(Equation 1)

Examples 2 to 22 The same experiment as in Example 1 was carried out except that the kind of the stabilizer and / or the addition ratio thereof was changed. Table 1 shows the results.

[0011]

[Table 1]

Example 23 Stainless steel SU304 was previously dissolved in an aqueous solution comprising hydrochloric acid, hydrofluoric acid and hydrogen peroxide, and the solution was used to obtain 20 g of hydrochloric acid.
/ L, hydrofluoric acid 40g / l, iron 10g / l, chromium 2g /
A solution containing 1 g / l of nickel, 1 g / l of nickel and 0.10 g / l of ethylene glycol monophenyl ether was added, hydrogen peroxide was added to a concentration of 20 g / l, and the mixture was left at 50 ° C. for 5 hours. Was measured for stability.

Examples 24 to 27 The same experiment as in Example 23 was carried out except that the kind of the stabilizer and / or the addition ratio thereof were changed. Table 2 shows the results.

[0014]

[Table 2]

COMPARATIVE EXAMPLE 1 Hydrogen peroxide was added to a solution containing 20 g / l of hydrochloric acid, 40 g / l of hydrofluoric acid and 10 g / l of iron so that the concentration became 20 g / l.
After standing at 0 ° C. for a period of time, the stability of hydrogen peroxide was measured.

Comparative Example 2 20 g / l of hydrogen peroxide was added to a solution containing 20 g / l of hydrochloric acid, 40 g / l of hydrofluoric acid, 10 g / l of iron, and 1.0 g / l of ethanol.
1 and left at 50 ° C. for a period of time. <During that time, the stability of hydrogen peroxide was measured. Table 3 shows the results.

[0017]

[Table 3]

Claims (2)

[Claims] 1. A method for stabilizing an aqueous solution of acidic hydrogen peroxide, comprising adding at least one compound selected from phenyl glycol ethers and cyclic saturated alcohols to an aqueous solution of acidic hydrogen peroxide containing iron. 2. The method according to claim 1, wherein the compound to be contained comprises a combination of at least one of phenyl glycol ethers and at least one of cyclic saturated alcohols.