JP2013133438A - Neutral detergent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a neutral detergent with a high cleaning effect, alleviating the environmental load of waste liquid, and applicable widely to indoor equipment.SOLUTION: The neutral detergent prepared by dissolving a surfactant in water includes dialkyl sulfosuccinate and polyoxyalkylene alkyl ether as surfactants. The content of the dialkyl sulfosuccinate to the total amount of the two elements is 1-20 wt.% and that of the polyoxyalkylene alkyl ether to the same is 80-99 wt.%. The concentration of the surfactant is 10-100 ppm.

Description

  The present invention relates to a neutral cleaning agent, and more particularly to a neutral cleaning agent that is obtained by dissolving a specific surfactant in water and is particularly suitable for high-pressure cleaning.

  Equipment, instruments, plants, etc., may deteriorate in function due to contamination of the product surface due to long-time operation, and require periodic cleaning. By the way, conventional cleaning agents (generally having a surfactant concentration of several hundred ppm or more) are not suitable for high-pressure cleaning of outdoor equipment used in large quantities because of high COD of waste liquid and high environmental load. Therefore, high-pressure cleaning is often performed only with water without using a surfactant.

  Recently, a steam cleaning method has been proposed in order to enhance the cleaning effect (Patent Document 1). However, the steam cleaning method has the disadvantage that it is limited to cleaning equipment installed in a plant with a steam source.

JP 2006-231179 A

  The present invention has been made in view of the above circumstances, and its purpose is not limited to equipment installed in a plant equipped with a steam source, and can be widely applied to equipment installed outdoors, An object of the present invention is to provide a neutral cleaning agent having a high cleaning effect and a reduced environmental load of waste liquid.

  As a result of intensive studies, the present inventors have found that if two specific types of surfactants selected from many known surfactants are used in a specific ratio, the interface in a conventional cleaning agent is used. It was found that a high cleaning effect was achieved while the concentration was significantly lower than the concentration of the active agent.

  The present invention has been completed based on the above findings, and the gist of the present invention is a neutral detergent obtained by dissolving a surfactant in water. As the surfactant, dialkylsulfosuccinate and polyoxyalkylene are used. The ratio of the dialkylsulfosuccinate is 1 to 20% by weight, the ratio of the polyoxyalkylene alkyl ether is 80 to 99% by weight, and the concentration of the surfactant is 10%. It exists in the neutral detergent characterized by being -100 ppm.

  According to the present invention, the above-described problems are achieved.

  Hereinafter, the present invention will be described in detail. The neutral detergent of the present invention is obtained by dissolving a surfactant in water, but it is important that the surfactant contains a dialkyl sulfosuccinate and a polyoxyalkylene alkyl ether in a specific ratio.

  The dialkyl sulfosuccinate is represented by the general formula (I).

In general formula (I), R ¹ and R ² each independently represents an alkyl group having 4 to 22 carbon atoms (preferably 6 to 18, more preferably 8 to 14), and X represents a counter ion. Examples of the counter ion include an alkali metal ion, an ammonium ion, and an alkanolamine ion. Dialkyl sulfosuccinates are one of anionic surfactants and many are commercially available. Specific examples include sodium dioctyl sulfosuccinate, sodium didecyl sulfosuccinate, sodium didodecyl sulfosuccinate and the like. It is done.

The polyoxyalkylene alkyl ether is produced by adding an alkylene oxide such as ethylene oxide (EO) or propylene oxide (PO) to a higher alcohol, and is represented by a general formula: R— (AO) _n H. Here, R is a linear or branched hydrocarbon group having 4 to 22 carbon atoms (preferably 6 to 18, more preferably 8 to 14 carbon atoms), AO is an ethylene oxide group, a propylene oxide group, a butylene oxide group, or the like. It is a residue selected from alkylene oxide, Comprising: n is 3-50 (preferably 5-20). Polyoxyalkylene alkyl ether is one type of nonionic surfactant, and commercially available products can be used.

  The ratio of the dialkyl sulfosuccinate and the polyoxyalkylene alkyl ether is 1 to 20% by weight, preferably 5 to 15% by weight, and the ratio of the polyoxyalkylene alkyl ether to the total of both. 80 to 99% by weight, preferably 85 to 95% by weight. When the ratio of the dialkylsulfosuccinate and the polyoxyalkylene alkyl ether is outside the above range, a high cleaning effect cannot be achieved.

  The concentration of the surfactant is 10 to 100 ppm, preferably 25 to 80 ppm. When the concentration of the surfactant is less than 10 ppm, the significance of containing the surfactant is lessened. When the concentration exceeds 100 ppm, not only is the cleaning effect flattened and it is not economical, but also the environmental load of the cleaning waste liquid increases and the cleaning waste liquid Foaming is induced, making it unsuitable for high-pressure washing using a high-pressure washing machine outdoors. In the present invention, as long as the effects of the present invention are not impaired, other surfactants can be used in combination with the two types of surfactants, but the total concentration of the surfactant dissolved in water is It is important that the above range.

  The method of using the cleaning agent of the present invention is not particularly limited, but the cleaning agent of the present invention is suitable for high-pressure cleaning by taking advantage of its characteristics, and is suitable for cleaning various outdoor facilities, particularly heat exchangers in power plants. Excellent effect can be expected. The high pressure cleaning is performed by using a general high pressure washer and ejecting a cleaning agent from the nozzle tip. The cleaning pressure is appropriately selected according to the contamination of the surface to be cleaned.

  In addition, since the cleaning agent of this invention has low foamability (high foaming property), it has the following advantages. That is, in high-pressure cleaning, the surface to be cleaned with few bubbles is immediately visually observed, the degree of cleaning can be easily confirmed, and the subsequent cleaning operation can be performed quickly, so that the cleaning operation can be performed efficiently.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Examples 1-5 and Comparative Examples 1-6:
Surfactants shown in Table 1 were dissolved in water at the concentrations shown in the same table to prepare cleaning agents, and the items described below were evaluated.

  Surfactants A to E in Table 1 mean combinations of dialkyl sulfosuccinates and polyoxyalkylene alkyl ethers, and the proportions are as shown in Table 2. As dialkylsulfosuccinic acid, dioctylsulfosuccinic acid and didodecylsulfosuccinic acid are used, and as polyoxyalkylene alkyl ether, polyoxyethylene polyoxypropylene tridecyl ether ("Neugen TDX-50" manufactured by Daiichi Kogyo Co., Ltd.), polyoxyethylene Lauryl ether (“Brownon EL-1507” manufactured by Aoki Yushi Co., Ltd.) and polyoxyethylene polyoxypropylene isodecyl ether (“Fine Surf IDEP-608” manufactured by Aoki Yushi Co., Ltd.) were used.

<Detergency evaluation>
The cleaning test plates described below were used, and the cleaning methods described below were performed and evaluated in five stages. The results are shown in Table 3.

(Cleaning test plate)
The following slate plates were prepared as cleaning test plates.
Slate plate 1: A slate plate of 90 cm × 60 cm was left outdoors for one month to form dirt due to scales or the like.
Slate plate 2: A mixture of 90 parts by mass of mineral oil and 10 parts by mass of carbon black was used as a pseudo stain, and a predetermined amount was applied to the surface of a 90 × 60 cm slate plate. The slate plate was dried at 120 ° C. for 20 hours and adhered to the slate plate as dirt.

(Cleaning method)
Each of the adjusted cleaning liquids 3L was evenly discharged on the slate plate with the two types of dirt attached thereto over a period of 1 minute with a commercially available high-pressure washer for cleaning. After washing and leaving at room temperature for 1 day to dry, the slate plate was visually evaluated for the following five levels.
1: Dirt on the entire slate plate could be removed.
2: Although some dirt remained, most of the dirt could be removed.
3: There was dirt that could not be removed partially.
4: Only a small amount of dirt could be removed.
5: Almost no dirt could be removed.

<COD evaluation>
The COD was measured by the potassium permanganate method defined in JIS K 0102 “Factory drainage test method” for the cleaning solution used in the above-described cleaning property evaluation. The results are shown in Table 3.

<Defoaming evaluation method>
About the washing | cleaning liquid used for the above-mentioned washing | cleaning property evaluation, the defoaming property was evaluated on the following conditions using the homomixer. The results are shown in Table 4.

(Evaluation conditions)
Homomixer: “TK Robotics” manufactured by PRIMIX
Cleaning liquid volume: 600ml
Container: 1L tall beaker Liquid temperature: 25 ° C
Homomixer operating conditions: 4000 rpm, 1 minute, top plate position is 1 mm below the liquid level
Defoaming property measurement: After operating the homomixer to foam the cleaning liquid, the bubble height immediately after the homomixer was stopped and the transition of the foam height over time are measured on a tall beaker scale (no unit).

  The following can be understood from the results of Examples and Comparative Examples. That is, as shown in Table 3, in the comparative example, the evaluation was 3 to 5 by visual evaluation, and the dirt could not be removed sufficiently. On the other hand, in the examples, the visual evaluation was 1 to 3, and a good cleaning effect was obtained. Moreover, in order to efficiently perform the washing operation of the high pressure washing, the foam breaking property in a short time is required. However, as shown in Table 4, in the examples, the scale of the tall beaker becomes “650”. The time is 30 seconds and is short.

Claims (2)

  A neutral detergent obtained by dissolving a surfactant in water, which contains a dialkyl sulfosuccinate and a polyoxyalkylene alkyl ether as the surfactant, and is a ratio of the dialkyl sulfosuccinate to the total of both. A neutral detergent characterized by a proportion of 1 to 20% by weight, a proportion of polyoxyalkylene alkyl ether of 80 to 99% by weight, and a surfactant concentration of 10 to 100 ppm.   The neutral detergent according to claim 1, which is for high pressure washing.