JPH0674948A - Simple concentration control method for surface treating agent - Google Patents

Abstract

PURPOSE:To control concentration easily by adding an indicator after two solutions are prepared for the upper limit and the lower limit of solution control normality, and identifying whether or not it is within range of the normality after treating solution to be measured is added to this. CONSTITUTION:Solution in the lower limit normality of concentration control width of solution to be measured is prepared beforehand. For example, when the lower limit of the solution to be measured is acid or alkali of 0.2 normal in the normality, the acid or the alkali of 0.1 normal may be prepared twice a gathering quantity. An indicator is added beforehand to this solution. Next, treating solution is added by a constant quantity to this solution. With this, identification can be made immediately on whether the treating solution is in the lower limit or above control width. Next, solution in the normality of the upper limit value is prepared similarly. In the same way as the lower limit value is measured, the normality and a quantity of the prepared solution may be adjusted or regulated by the normality of the acid or the alkali. In this way, the upper limit and the lower limit of control width of the treating solution can be measured instantly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a simplified method for controlling the concentration of a surface treatment agent for washing a substance or chemically obtaining an anticorrosive film on the surface of a metal or the like.

[0002]

2. Description of the Related Art Usually, a surface treatment agent for cleaning substances or chemically obtaining a rust preventive film on the surface of a metal, that is, a cleaning agent, a rust preventive film forming agent, an acid detergent, etc.
Or contains alkali. Such an acid or alkali solution is brought into contact with the object to be treated by a method such as dipping or spraying for cleaning, film formation, or surface etching. There is an appropriate chemical concentration for cleaning, film formation, and surface etching of the object to be treated by such a method.For example, a certain amount of the chemical treatment liquid is sampled and an indicator that changes color depending on pH is dropped and treated. If the solution is an acid, add an alkaline solution.If the treatment solution is alkaline, add an acid solution.Depending on the amount of alkali or acid consumed until the color of the indicator changes,
The drug concentration is being measured.

[0003]

The concentration of the treatment liquid is measured by such a method, but for cleaning, film formation, surface etching, etc., each treatment liquid is treated in a predetermined time or temperature. There is an appropriate concentration range for the drug,
If it is used at a concentration lower than that, cleaning, film formation or surface etching will be hindered, and if it is used at a concentration higher than the predetermined concentration, it will be uneconomical. However, in this concentration measurement, it is necessary to take a certain amount of processing liquid, add an indicator, add an acid or alkaline solution with a certain normality, and check the discoloration of the indicator, which requires time and skill. Was needed.

[0004]

SUMMARY OF THE INVENTION The present invention proposes a method for shortening the time required for the concentration control and for easily controlling the concentration without requiring skill.

[0005]

[Means for Solving the Problem] In order to eliminate the time and skill required, first, a solution is prepared in advance which has a lower limit of the control width of the solution to be measured. For example, when the lower limit of the measurement solution is 0.2N acid or alkali with normality, 0.1N acid or alkali may be prepared in an amount twice as much as the collected amount. The specified amount of acid or alkali may be prepared in the same amount as the sampled amount. This liquid is prepared in advance in a bottle, a transparent liquid-tight bag, or the like. The indicator is added to this solution in advance or at the time of measurement. Next, a fixed amount of the treatment solution is added to the acid or alkali solution. Only by this, it is possible to immediately judge whether the treatment solution at the time of measurement is at the lower limit of control or above. Next, an acid or alkali solution having a normality of the upper limit value of the treatment solution to be measured is prepared in the same manner as above. The normality and amount of the prepared acid or alkali solution may be adjusted by the normality of acid or alkali as in the measurement of the lower limit value, or may be specified by the amount. In this way, the upper and lower limits of the control width of the treatment solution can be measured instantly.

[0006]

EFFECTS OF THE INVENTION In this way, two solutions are prepared with the upper and lower limits of the control normality of the solution to be measured, and an indicator is added in advance to measure in the solution. By simply adding the treatment liquid and observing the discoloration of the measurement reagent, it is possible to immediately know whether the control is within the control range. When the present invention is used, the measurement time of the treatment liquid can be greatly shortened, and the skill of neutralization titration is not required, and the treatment liquid can be managed very easily.

Claims (1)

[Claims] In neutralization titration for measuring the concentration of a metal surface treatment agent, two prescribed concentration liquids with known concentrations are prepared in fixed amounts, and a pH indicator intervenes to keep a constant concentration of an aqueous solution of the metal surface treatment agent. The amount is added to each of the two specified concentration solutions, and the concentration of the aqueous solution of the surface treatment agent can be easily controlled by checking whether the concentration of the aqueous solution of the surface treatment agent is within the range of the two specified concentrations due to the color change of the pH indicator. How to do