JPS6241298A - Detergent - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a cleaning agent, particularly for removing scale and rust adhering to cooling water pipes, hot water pipes, chillers, water supply pipes, water tanks, etc. of buildings and equipment. This invention relates to a cleaning agent used for cleaning.

[Background of the invention]

BACKGROUND ART Buildings and equipment are generally cooled and 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 acid-based cleaning agents have a strong cleaning power and are stable against strong acids such as hydrochloric acid, they require long-term rewashing of equipment with water to neutralize wastewater after cleaning and prevent rust from forming. It was necessary. On the other hand, a weak acid such as an aqueous phosphoric acid solution has a drawback in that the cleaning effect is weak. 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. Peroxide-based and chelate-based 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, to which boric acid is added, as shown in Japanese Patent Publication No. 59-50720, has been proposed, but it is safe. There was a problem with sexuality.

[Purpose 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 has previously proposed a neutralized cleaning agent containing 1-hydroxyethane-1,1-diphosphonic acid, an alkylbenzenesulfonic acid type surfactant, and a polyoxyalkylene alkyl ether type surfactant as main components, but it is safe. Although it can be stored for a long time, it has little ability to remove heavily adhered scale, so it causes a chelation reaction.
-Hydroxyethane-1,1-diphosphonic acid and an alkylbenzenesulfonic acid type surfactant that increases penetrating power have a first stage dissociation constant (pka) of about 2, which is not so low, and phosphoric acid, which is a tribasic acid. By incorporating the above, we 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 invention comprises 1-hydroxyethane-1,
An aqueous solution containing 2% by weight of 1-diphosphonic acid, 1% by weight of boxyalkylene alkyl ether, 3% by weight of sodium alkylbenzenesulfonate, and 10% by weight of phosphoric acid was obtained. P of this aqueous solution is approximately 2.

The above aqueous solution 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 had particularly severe scale, and was circulated for one hour.

This experiment was conducted at 10 sites, and the results are shown in the table below.

However, the criteria for judgment are: ◎Niscale has completely fallen off, ○
Two scales are almost completely removed, some Δ two scales remain, and a considerable amount of × two scales remain.

As shown in the table above, scale could be effectively removed at all sites.

By incorporating a polyoxyalkylene alkyl ether type surfactant into the above-mentioned cleaning agent, it is possible to further increase the permeability and scale removal effect.

Since this cleaning agent is an acid, it should be neutralized before disposal.

In other words, a solution such as sodium hydroxide may be used, but it is better to neutralize with an alkali such as sodium carbonate if possible. In particular, sodium carbonate, by hydrolysis,
OH, NaHCO.

It becomes a mixed solution of , and the pH does not increase due to the buffer solution.

〔Effect of the invention〕

As explained above, the present invention provides 1-hydroxyethane-
Since the main ingredients are 1,1-diphosphonic acid, an alkylbenzenesulfonic acid type surfactant, and phosphoric acid, a cleaning agent that can be stored for a long time and can effectively remove even severe scale can be obtained. .

Claims (1)

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