JPH0470398B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Application of the Invention] The present invention relates to a cleaning agent, and particularly to a cleaning agent used for removing scale and rust adhering to cooling water pipes, hot water pipes, refrigerators, water supply pipes, water tanks, etc. of buildings and equipment. [Background of the Invention] Buildings and equipment are generally cooled or heated by passing water or hot water through pipes. However, because water and hot water are constantly flowing through the pipes, polyvalent metal ions such as iron, calcium, and magnesium contained in the water adhere to them and cause rust, a phenomenon that reduces the effectiveness of cooling and heating. is likely to occur. Therefore, cleaning agents are needed to remove scale and rust that adhere to pipes, etc. Conventionally, these types of cleaning agents have been acid-based using hydrochloric acid or mineral acids, and alkaline-based cleaning agents using sodium hydroxide, etc. Peroxide-based products using hydrogen peroxide, hypochlorous acid, etc., and chelate-based products using ethylenediaminetetraacetic acid, etc., are used. However, while acidic cleaning agents have a strong cleaning power and are stable against strong acids such as hydrochloric acid, they require a long period of re-rinsing the equipment with water to neutralize the waste water after cleaning and prevent the formation of rust. It was hot. On the other hand, weak acids such as water-soluble phosphoric acid have a disadvantage in that the cleaning effect is weak. Furthermore, although alkaline detergents have strong cleaning power, they have the disadvantage that, like acid-based detergents, they require neutralization of waste water and are dangerous to the human body due to their strong basicity. Although peroxide-based cleaning agents are not very dangerous in handling, the compound itself is unstable and difficult to store for long periods of time. Furthermore, chelate detergents were selective in their effectiveness. In addition, as a special cleaning agent, a scale cleaning agent containing ammonium hydrogen fluoride and hydrochloric acid as the main components, with the addition of boric acid, as shown in Japanese Patent Publication No. 59-50720, has been proposed, but it is safe. I had a problem with my sexuality. [Object of the Invention] An object of the present invention is to provide a cleaning agent that can effectively remove scale and rust and can be stored for a long time. [Summary of the invention] The present invention first provides 1-hydroxyethane-1,
We proposed a neutralized cleaning agent containing 1-diphosphonic acid, an alkylbenzenesulfonic acid type surfactant, and a polyoxyalkylene alkyl ether type surfactant as the main ingredients, but although it is safe and can be stored for a long time, it is not effective against heavily adhered scale. Because of its low removal ability, 1-hydroxyethane-1,1-diphosphonic acid, which causes a chelation reaction, and an alkylbenzenesulfonic acid type surfactant, which increases penetration power, have a dissociation constant (pka) of approximately 2 in the first stage. By incorporating phosphoric acid, which is a tribasic acid, we have obtained a cleaning agent that has the above advantages and can effectively remove scale. [Embodiments of the Invention] Examples of the present invention will be described below. The cleaning agent according to the present invention contains 2% by weight of 1-hydroxyethane-1,1-diphosphonic acid, 1% by weight of polyoxyalkylene alkyl ether, 3% by weight of sodium alkylbenzenesulfonate,
An aqueous solution containing 10% by weight of phosphoric acid was obtained. The pH of this aqueous solution is approximately 2. The aqueous solution described above was poured into a water pipe that had been used for water cooling in a hydraulic elevator that had been in operation for more than 10 years, and was particularly heavily scaled, and was circulated for one hour. This experiment was conducted at 10 sites, and the results are shown in the table below.

【table】

〔Effect of the invention〕

As explained above, since the present invention contains 1-hydroxyethane-1,1-diphosphonic acid, an alkylbenzenesulfonic acid type surfactant, and phosphoric acid as the main ingredients, it can be stored for a long period of time and has no severe scale. The result is a cleaning agent that can effectively remove even the most harmful substances.

Claims (1)

[Claims] 1. A cleaning agent characterized by containing 1-hydroxyethane-1,1-diphosphonic acid, an alkylbenzenesulfonic acid type surfactant, and phosphoric acid as main components.