JPS6024385A - Deoxidizer - Google Patents

Abstract

PURPOSE:To obtain a deoxidizer having superior deoxidizing power and usable in place of hydrazine by blending an oxidation-reduction catalyst with aminoguanidine or a salt thereof. CONSTITUTION:This deoxidizer contains an oxidation-reduction catalyst and aminoguanidine or a salt thereof. One or more kinds of compounds selected among hydroquinone, lower alkylhydroquinones such as methylhydroquinone and catechol are used as the catalyst. Oxidation type quinones such as quinone and methylquinone may be used. The amount of the catalyst contained is 0.05- 20pts.wt., preferably 0.1-5pts. per 1 part aminoguanidine. The amount of aminoguanidine to be added to a water system is usually about 5-150mg/l in case of a low pressure boiler.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composition for chemically removing oxygen dissolved in water.

Water dissolves oxygen when it comes into contact with the atmosphere, but when water containing dissolved oxygen is used as industrial water, such as zeira water or cooling water, corrosion problems arise due to the dissolved oxygen. For this reason, it is essential to remove dissolved oxygen from the water before water is supplied or within the system where water is used.Oxygen is removed by chemical methods using reducing agents, and physical methods such as vacuum and heating. .

Conventionally, a deoxygenation method using hydrazine has been used as a chemical treatment method. Hydrazine is one of the preferable compounds because it removes oxygen from water relatively quickly when mixed with a redox catalyst such as hydroquinone. However, hydrazine has the potential to have an adverse effect on the human body if mishandled, so finding a substitute for hydrazine has become an urgent issue for industries that use hydrazine.

An object of the present invention is to provide PIFK, which is a substitute for hydrazine and provides an oxygen scavenger with excellent deoxidizing force.

As a result of extensive research, the present inventors have discovered that aminoguanidine or its salt has the ability to sufficiently remove dissolved hexagonal ions, which cause corrosion such as irradiation, under a redox catalyst. This led to the present invention. That is, the present invention is an oxygen scavenger containing a redox catalyst and aminoguanidine or a salt thereof.

As the redox catalyst, at least one selected from hydroquinone, lower alkylhydroquinone such as methylhydroquinone, and catechol can be used. As for quinones, oxidized forms (quinone, methylquinone) can also be used.

If these catalysts are not blended, the deoxidizing power of aminoguanidine is almost too strong, but in the presence of a catalyst, aminoguanidine is estimated to exhibit deoxidizing power according to the following formula %.

Examples of aminoguanidine salts include sulfate and hydrochloride.

The mixing ratio of the redox catalyst and aminoguanidine is 0.05 to 20 parts by weight, preferably 0.1 to 5 parts by weight, per 1 part by weight of aminoguanidine. 1. The amount of aminoguanidine added to the water system is usually about 5 to 150 Da/L for low-pressure zein.

Furthermore, low pressure? Ira water condition is pressure 30 Ky/cr
Below A, the pH is 11-12. The deoxidizing power of aminoguanidine itself is not affected by pH, but the redox catalyst is dependent on pH, and the higher p)(, the better the catalytic effect, and the better the deoxidizing power of the composition.

To use the present invention, the catalyst and aminoguanidine may be blended in advance to form an aqueous solution and then added to the aqueous system, or each compound may be added separately to the aqueous system.

Example 500 cc of pure water (containing saturated oxygen) was supplied to a wide-mouth bottle with a tight stopper, and the pH was adjusted to 11.0 using a caustic sorter. The temperature was 20°C.

To this water, add 50 mfJ/l (ppm) of aminoguanidine as its gi mistake and 2, 6, and 10 my/l (ppm) of hydroquinone, respectively.
) was added under stirring to examine changes in dissolved oxygen over time. The results are shown in the figure. In the figure, AG represents aminoguanidine and HQ represents hydroquinone.

For comparison, only hydroquinone was used at 2.6゜1omg/
Even when L is added, mt! A. The results are shown in the figure.

This shows that a sufficient oxygen removal effect can be obtained by using aminoguanidine in combination with hydroquinone (oxidation-reduction catalyst). In particular, when the blending ratio of aminoguanidine and hydroquinone is 1:0.1 or more, the oxygen scavenging effect is significantly improved.

[Brief explanation of drawings]

The figure shows aminoguanidine (AG, ) and hydroquinone (H
This is a graph showing the change over time in the bath oxygen power i when Q) is added to water. 1 person outside time (ga)

Claims (1)

[Scope of Claims] 1. A de-accumulation agent containing a redox catalyst and aminoguanidine or a salt thereof. 2. The raw material according to item 1, item 1, item 1 of item 11, wherein the redox catalyst is at least one selected from the group consisting of hydroquinone, methylhydroxyne, and catechol.