JPS6327284B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to a stabilizer for hydrazine compounds. Hydrazine compounds have reducing properties and are used as water treatment agents in industrial and wastewater systems. Water treatment agents include oxygen scavengers for closed systems such as boilers,
It is used as a slime control agent in open systems such as cooling water systems and papermaking water systems, together with other agents such as anticorrosive agents and scale inhibitors. However, hydrazine compounds are unstable and are decomposed by dissolved oxygen in water, and in systems where metal ions are present or metal materials are used at a pH of 4 or higher, hydrazine compounds may be decomposed in amounts greater than the amount of dissolved oxygen. decomposes violently. Therefore, in order to maintain water treatment effects such as slime prevention effects, it is necessary to use large amounts of hydrazine compounds, which increases treatment costs and causes problems such as high concentrations of hydrazine compounds corroding copper materials. It was hot. This invention is intended to solve these problems, and aims to provide a stabilizer that can prevent the decomposition of hydrazine compounds and maintain water treatment effects. 1 selected from fatty acid ethylene oxide adducts, alkylphenol ethylene oxide adducts, sorbitan fatty acid esters, polypropylene glycol ethylene oxide adducts, polyoxyethylene alkylamines, quaternary ammonium salts, quaternary phosphonium salts, amino acid salts, and dialkyl ester sulfonates A stabilizer for a hydrazine compound selected from hydrazine and hydrazine hydrate, characterized by containing at least one surfactant as an active ingredient. The hydrazine compound to be stabilized in the present invention is a compound having a hydrazino group, and is selected from hydrazine and hydrazine hydrate. Surfactants include fatty acid ethylene oxide adducts, alkylphenol ethylene oxide adducts, sorbitan fatty acid esters, polypropylene glycol ethylene oxide adducts, polyoxyethylene alkylamines, quaternary ammonium salts, quaternary phosphonium salts, amino acid salts, and dialkyl ester sulfones. There is one or more types selected from acid salts. These surfactants are used by adding them to systems where decomposition of hydrazine compounds is a problem. Examples of systems in which decomposition of hydrazine compounds is a problem include systems in which decomposition occurs in a product before use as a chemical such as a water treatment agent, and systems in which decomposition occurs during use of the chemical. In systems where degradation occurs prior to use, surfactants are added to the drug. Furthermore, in systems where decomposition occurs during use, a surfactant may be incorporated into the drug or added directly to the target system together with the drug or separately. The hydrazine compound to be stabilized may be added to the target system alone or together with other drugs. When hydrazine compounds are used as water treatment agents, they are mainly used as oxygen scavengers and slime control agents in closed systems, and as slime control agents in open systems. May be used and in combination with other drugs. Examples of agents used in combination include anticorrosive agents and anti-scaling agents. When preventing decomposition in drug products, the amount of surfactant added should be 0.01 to hydrazines.
~50% by weight, and when preventing decomposition in the target system, the concentration of the surfactant is approximately 0.1 to 100 mg/. Although the above description concerns the use of the hydrazine compound as a water treatment agent, stabilization can be performed in other applications as well. As explained above, according to this invention,
It is possible to stabilize unstable hydrazine compounds, prevent their decomposition, and maintain high activities such as water treatment activity. Therefore, the amount of hydrazine compounds used can be reduced, and the concentration of additives can be lowered to improve copper materials. It is possible to reduce the corrosiveness against etc. In addition, when hydrazine compounds are used as water treatment agents, they have extremely good slime control effects, and
The anti-scaling and anti-corrosion effects are also improved. Next, examples of the present invention will be described. Example 1 PH8.5, calcium hardness 300mg/asCaCO ₃ , M
One copper test piece (30mm x 50mm) was immersed in water with an alkalinity of 300mg/asCaCO ₃ , and heated at 30℃.
Add hydrazine 20 to a system stirred at 300 rpm.
mg/ml and various surfactants were added in the amounts shown in Table 1, and the residual rate of hydrazine 48 hours after the blank became O was determined by the following formula. The results are also listed in Table 1. Residual rate = N ₂ H ₄ concentration after 48 hours (mg/) / Initial N ₂ H ₄ concentration (mg/) × 100 In Table 1, No. 9 is Twin 80 (Kao Soap KK), No. 11
is Esomin T25 (Lion KK), No. 12 is α-alkoxypropyldimethylbenzyl ammonium chloride, No. 13 is Verklein 350 (Ciba Geigy), No. 14 is Opanol 516 (Toho Chemical KK), No. 15
is Aerosol OT (Sanyo Chemical Industries KK).

【table】

[Table] Example 2 The water treatment chemicals shown in Table 2 were tested using an open circulating water system monitoring device.

[Table] The monitoring device has a holding water volume of 15 and a circulating water volume of 300.
/hr, flow rate 0.5m/s, residence time 120hr, inlet temperature of heat transfer tube (made of SUS, heat transfer area 0.0471m ² )
30℃, outlet temperature 35℃, average surface temperature 50℃,
Non-heat transfer tube (SUS single tube,
A heat transfer area of 0.0471m2 ⁾ is used to constantly supply hot water at 30℃.
Mild steel and copper test pieces were immersed in the circulation pit by passing water at a rate of 300/hr and a flow rate of 5 m/s. The test water was synthetic water with a calcium hardness of 500 mg/m and an alkalinity of 500 mg/m, to which 2 g of activated sludge was added as a dry weight to promote slime generation, and a peptone glucose medium was added as a BOD load.
10g/m ³・day was added. In the test, each of the chemicals listed in Table 2 was added to the circulating water of the monitoring device at an initial concentration of 200 mg per amount of water held, and thereafter at a concentration of 200 mg per blown water.
mg/, and water was passed for about 2 weeks.
The amount of slime adhesion, the amount of scale adhesion, the corrosion rate of copper and mild steel test pieces, and the residual concentration of hydrazine were measured. The results are shown in Table 3. Note that the amount of scale adhesion is the value obtained by subtracting the loss on ignition from the total amount of adhesion on the heat transfer tube.

[Table] From the results in Table 3, it can be seen that the agent of the present invention has a higher residual hydrazine concentration, has an extremely good slime control effect, and has better scale prevention and corrosion prevention effects than the control agent.

Claims (1)

[Claims] 1 Fatty acid ethylene oxide adduct, alkylphenol ethylene oxide adduct, sorbitan fatty acid ester, polypropylene glycol ethylene oxide adduct, polyoxyethylene alkylamine, quaternary ammonium salt, quaternary phosphonium salt, amino acid salt, and dialkyl ester A stabilizer for a hydrazine compound selected from hydrazine and hydrazine hydrate, characterized in that the active ingredient is one or more surfactants selected from sulfonates. 2. The stabilizer for a hydrazine compound according to claim 1, wherein the hydrazine compound is used for water treatment.