JPS6116798B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an aquarium cleaning agent for removing stains mainly composed of iron oxide and carbonates of divalent metals adhering to the wall surfaces of elevated aquariums or underground aquariums. Currently, buildings with a floor area of 3,000m2 ^{or more} are required by law to clean their elevated and underground water tanks (remove dirt from walls) every year. The main components of the adhered dirt are scales mainly composed of iron oxide, iron hydroxide, and carbonates of divalent metals, as well as clay minerals, slime, and the like. Conventionally, such stains have been removed by a cleaning method using an inorganic acid-based or surfactant-based cleaning agent. However, inorganic acid-based cleaning agents tend to cause corrosion of the aquarium wall surface and have problems in cleaning operations, such as a strong irritating odor. Furthermore, if these strong acids remain in a water tank or the like, there are serious problems such as corrosion of metal piping and problems when serving drinks. Surfactant-based cleaning agents have not been able to sufficiently remove scales such as iron oxide, iron hydroxide, and carbonates of divalent metals. An object of the present invention is to solve the above problems and provide a cleaning agent that can easily remove dirt adhering to the walls of an elevated water tank or an underground water tank, and that does not cause safety problems for work surfaces and human bodies. It's there to do. As a result of intensive research, the present inventors have discovered that the above object can be achieved by using an organic acid that is approved as a food additive, leading to the present invention. That is, the cleaning agent of the present invention is characterized by containing as an active ingredient two or more organic acids selected from the group consisting of oxalic acid, lactic acid, citric acid, gluconic acid, ascorbic acid, and malic acid. be. Among the above organic acids, aqueous solutions of oxalic acid, citric acid, and malic acid each independently exhibit good dissolving power for iron oxide, iron hydroxide, and carbonate of divalent metals.
However, since oxalic acid may precipitate salts with low solubility such as iron oxalate and calcium oxalate, and citric acid may precipitate salts with low solubility such as iron citrate, a sufficient cleaning effect cannot always be obtained. Therefore, by using a mixed acid system of two types, such as oxalic acid and citric acid, citric acid and ascorbic acid, or three types, such as oxalic acid, citric acid, and malic acid, a strong additive effect is expressed, and the above-mentioned Excellent cleaning effects can be obtained without precipitating salts. As a method for cleaning an aquarium wall surface using the cleaning agent of the present invention, a coating cleaning method is excellent because the cleaning agent can be used economically and effectively. That is, a solution containing an organic acid dissolved at a concentration of 1% or more, preferably 3% or more is used as a cleaning agent, and this is applied to the dirty parts of the elevated water tank or underground water tank wall with a sponge, brush, spray, etc., and iron oxide, iron oxide, etc. Dissolve iron hydroxide and carbonates of divalent metals. In order to enhance the coating effect, it is better to mix 0.1 to 5% of a thickener such as methyl cellulose or gar gum. If the dirt is stubborn, you can dissolve it in a short time by rubbing it off with a sponge or the like before the coated surface dries. After dissolving the deposits, thoroughly wash the wall surface with high-pressure spray water, etc., and completely drain the cleaning waste liquid out of the water tank to avoid problems such as cleaning agent and dirt remaining in the water supply piping. do not have. Hereinafter, the effectiveness of the present invention will be clarified through experimental examples and examples. Experimental Example Deposits collected from the wall of an underground water tank that had been used for many years were dissolved using the organic acids shown in the table below, and the amounts of eluted iron ions and calcium ions were measured. The method is to first take 500 ml of a drug solution with a specified concentration into a 500 ml conical beaker, add 10 g of a scale sample (composition: 58% Fe ₂ O ₃ , 17% CaCO ₃ ), and dissolve it at a liquid temperature of 20°C for 4 hours while stirring. Then, the amount of eluted iron ions and calcium ions was measured by atomic absorption spectrometry. The results are shown in the table below, and the effectiveness of the present invention can be understood.

【table】

[Table] Example In an elevated condominium water tank (water capacity: 10 m ³ ), 2 kg of a mixed solution of 5% oxalic acid and 5% citric acid was used for cleaning by the coating cleaning method described above. Before cleaning, the wall surface had a reddish-brown color due to adhesion of scale mainly composed of iron oxide and iron hydroxide, but by using the above mixture, the wall surface became clean and the deposits were sufficiently removed. Ta. On the other hand, the elevated water tank in the separate building (water capacity: 5
m ³ ) was washed with water, but the wall remained reddish-brown even after washing, and no removal effect was observed.

Claims (1)

[Claims] 1. A cleaning agent for elevated water tanks or underground water tanks, which contains as an active ingredient two or more organic acids selected from the group consisting of oxalic acid, lactic acid, citric acid, gluconic acid, ascorbic acid, and malic acid.