JPH09217093A - Non-rinse detergent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a non-rinse detergent containing a specific ammonium compound and useful for the cleaning of metals to give a cleaned metal having excellent appearance free from drying unevenness and spot similar to a detergent containing fluorocarbons or chlorine-based solvents. SOLUTION: This detergent is an aqueous solution containing an ammonium compound of formula, (NH4 )n X (X is hydroxyl group, carbonate group or bicarbonate group; (n) is 1 or 2). The concentration of the compound of formula is preferably adjusted to keep the pH to >=8.5. The cleaning power of the detergent can be improved by using the detergent in agitation cleaning, ultrasonic cleaning, cleaning under heating or spray cleaning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to cleaning of metals, and more particularly to a non-rinse type water-based cleaning agent. More specifically, a non-rinse type cleaning agent comprising an aqueous solution containing a compound represented by the formula (1), which can obtain a clean appearance even if it is dried without washing with water after removing stains such as oil and cutting chips. It is about.

[0002]

2. Description of the Related Art Conventionally, in cleaning metals, cleaning using chlorofluorocarbon or chlorine-based solvent has been mainly performed. However, since these solvents cause environmental damage, their use has been regulated worldwide, and there is a strong demand for alternative technologies to replace them. For this reason, in these industries, conversion to water-based cleaning is in progress, and cleaning using an aqueous cleaning agent and water cleaning using only a physical method without using cleaning components have been performed.

In the case of cleaning with a water-based cleaning agent, a method using a rinse-type cleaning agent is generally used in which dirt such as oil and cutting chips is removed by the cleaning agent, and then the cleaning components adhering to the product are rinsed and removed with a large amount of water. For example, various compositions are known for products to be cleaned and stains, as described in Tsuji Recommendation "Precision Cleaning Technology" Engineering Book, p106-120. However, it is not easy to adopt water-based cleaning agents in facilities that have traditionally used only CFC / chlorine-based solvents and do not have wastewater treatment facilities, or in facilities that cannot increase wastewater due to the capacity of drainage facilities. A non-rinse type water-based cleaning agent that does not require water rinsing is desired.

In the case of water cleaning in which dirt is removed by using only physical means such as heating, ultrasonic waves and high-pressure jet without using a cleaning agent component, the burden on wastewater treatment is greatly reduced.
However, in these aqueous cleaning methods, including the method using the above cleaning agent, in the drying step after cleaning,
Since unevenness in drying and stains are likely to occur, it is necessary to take preventive measures against these factors causing poor appearance.

The causes of unevenness of drying and stains can be roughly classified into evaporation residue due to water quality of washing water and oxidation during drying. Defects due to evaporation residue due to water quality can be prevented by controlling the water quality of the rinse water, but it is not easy to prevent defects due to oxidation, and various methods have been proposed.

For example, vacuum drying and drying in a nitrogen atmosphere can be mentioned, but the vacuum drying method requires high equipment costs.
Work efficiency is also low. Also, the equipment cost for drying in a nitrogen atmosphere is high, and since a large amount of nitrogen is used, the cost is high. These drying methods apply only for special products.

[0007] Further, as an antioxidant technique using a drug,
JP-A-53-55427 and JP-A-2-12588
There is known a method using an oxygen scavenger for removing dissolved oxygen in water as described in Japanese Patent Laid-Open No. But,
The use of the oxygen scavenger is mainly intended to prevent oxidation of metal in water in the water washing step, and the purpose is to remove a finite amount of dissolved oxygen in the water. On the other hand, since the usual drying process is performed in the atmosphere, it is an atmosphere in which oxygen is constantly present, and it is impossible to remove all the existing oxygen with a deoxidizer to prevent metal oxidation. Further, if the conventional aqueous solution containing the oxygen scavenger component is dried while attached, the oxygen scavenger component is deposited as an evaporation residue, resulting in uneven drying and stains.

Although the use of a corrosion inhibitor can prevent metal oxidation in the drying step, the corrosion inhibitor remains adsorbed on the metal surface, making it impossible to obtain a clean metal surface. Therefore, the residual corrosion inhibitor may be adversely affected in the subsequent processing step, and it becomes necessary to remove the corrosion inhibitor immediately before the processing of the next step.

Even if a passivation film forming agent is used and a good appearance without drying unevenness or stains is obtained, the metal surface is covered with a uniform oxide film (passive film). As with, it is impossible to obtain a clean metal surface. Therefore, the oxide film is adversely affected in the subsequent processing step, and it becomes necessary to remove the oxide film (passive film) before the processing of the next step.

[0010] A draining and replacing method of rinsing and washing with a solvent to replace and remove water on the surface of a product is generally adopted in a wide field, and this method prevents oxidation during drying. However, the solvent used in this drainage replacement method is a CFC / chlorine solvent, and in recent years, the use of low-toxicity solvents such as isopropanol has been proposed as an alternative technology to these, but these solvents are flammable (flammable). Therefore, there is a problem in safety as compared with the CFC / chlorine type solvent, and there is a drawback in that the equipment cost is high.

All of these various methods of preventing oxidation are insufficient, and it has been difficult with the prior art to prevent defects due to oxidation.

In particular, when a non-rinse type cleaning agent that reduces the burden on waste water treatment is used, it is not only difficult to prevent uneven drying and stains due to oxidation, like the rinse type cleaning agent. It is not easy to prevent uneven drying and stains due to evaporation residue due to the cleaning components. Examples of the non-rinse detergent include JP-A-6-80995. However, the cleaning agent described in this publication is not preferable because the cleaning agent component remains as a thin film on the product surface after drying. At present, the non-rinse cleaning, that is, the industrial implementation of the non-rinse type water-based cleaning agent that can substitute for the solvent cleaning capable of drying while the solvent adheres is hardly adopted.

CFCs or chlorine-based solvents are excellent cleaning agents in comparison with water-based cleaning agents from the viewpoints of cleaning ability and handleability, but in recent years, due to environmental problems such as groundwater pollution, air pollution, and ozone layer destruction. It is desirable to promote conversion to water-based cleaning. However, there is a need to ameliorate some of the water based cleaning deficiencies mentioned above.

[0014]

DISCLOSURE OF THE INVENTION The present invention provides a water-based cleaning agent that prevents the occurrence of uneven drying and stains as an alternative technique of a cleaning method using a solvent that causes environmental damage and that does not require a rinse water rinse. It is to be.

[0015]

Means for Solving the Problems As a result of earnest studies on the alternative technique of the cleaning method using a flon or a chlorine-based solvent, the present inventors have found that a cleaning agent comprising an aqueous solution containing a compound represented by the formula (1) Is a product that does not leave any detergent components on the product even if the product is dried without washing with rinsing water and a clean product is obtained, and at the same time prevents uneven drying and stains due to oxidation. I found a thing.

That is, the present invention relates to a detergent comprising an aqueous solution containing an ammonium compound represented by the formula (1).

[0017]

Embedded image (NH ₄ ) _n X (1) (X is a hydroxyl group, a carbonate group, a bicarbonate group, and n is 1 or 2)

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is a non-rinse detergent which can be directly dried without being washed with water after being treated with a detergent comprising an aqueous solution containing an ammonium compound represented by the formula (1).

The compound represented by the formula (1) used in the present invention evaporates or decomposes and scatters in the drying step, does not remain on the surface of the product, and has a high effect of preventing the oxidation of the product. Specific examples of the optimum compound for the compound represented by the formula (1) are ammonium hydroxide, ammonium carbonate, and ammonium bicarbonate.

In carrying out the present invention, the concentration of the compound represented by the formula (1) in the aqueous solution is not particularly limited,
At least the pH of the cleaning liquid is preferably maintained at 8.5 or higher. It is effective even if the pH is less than 8.5, but the product type,
Depending on the shape, water quality and drying method, uneven drying or stains may occur. In addition, although there is no particular limitation on the upper limit of the drying unevenness / stains, it is generally unsuitable for the pH to exceed 13.0 in consideration of handleability, economy and the like. Practically, in consideration of handleability, economy, etc., the type, shape, water quality, drying method, etc. of the product to be treated, usually p
It is suitable to maintain H 8.7 or more, preferably pH 9.0 to pH 13.0. Also, regarding the cleaning capacity,
There is little concentration dependence, and it is sufficient to keep the pH at 9.0 or higher.

Depending on the type and shape of the product, the type and amount of stains, etc., if the cleaning power and penetrating power are insufficient and the cleaning effect is not satisfied, physical means such as stirring, ultrasonic waves, heating, spraying, etc. should be used together. Is preferred.

The detergent of the present invention includes isopropanol,
In the formula (1) with known detergent components such as water-soluble alcohols such as n-butanol, alkanolamines such as monoethanolamine and ditanolamine, glycol ethers such as ethylene glycol monoalkyl ether and dipropylene glycol monoalkyl ether. It is also effective to use in combination with the compounds shown. These detergent components evaporate and scatter in the drying step, and neither drying unevenness nor stains due to evaporation residue occur, and at the same time, the antioxidant effect of the compound represented by formula (1) in the drying step is not impaired. The combination of is effective in improving the cleaning ability and is one of the preferable embodiments.

Further, in order to improve the permeability, a trace amount of surfactant can be added to the detergent of the present invention depending on the type, shape, type of stain, amount, purpose and use of the product. Generally, 1,0 depending on the type and properties of the surfactant.
Addition of more than 00 ppm is not preferable because it may cause uneven drying and stains. Therefore, when a surfactant is added, it is preferably 1,000 ppm or less. In this case, drying unevenness / staining is less likely to occur, the surface tension of the cleaning liquid is lowered, the permeability is increased, and the cleaning power is also improved.

The treatment method with the detergent of the present invention is by means of dipping, stirring, spraying, ultrasonic irradiation or the like. Depending on the type and shape of the product, the type and amount of dirt, and the production amount of the product, it may be preferable to employ a multi-step cleaning process. In the case where the washing step is multistage, the pH of the other washing tanks is not particularly limited as long as the pH of the washing solution containing the compound represented by the formula (1) is maintained at least 8.5 or more in the final tank. .

The washing time varies depending on the type and shape of the product, the type and degree of dirt, the treatment method, etc. and is not particularly limited. However, practically, 10 to 1,800 seconds is preferable. If it is less than 10 seconds, insufficient cleaning is likely to occur, and the product may have uneven drying and stains. Even if it exceeds 1800 seconds, there is no problem in the cleaning effect itself, but it is unsuitable from the viewpoint of productivity and economy.

[0026]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the invention is not limited to the following Examples.

Example 1 A test piece (steel, SS400, 50 × 30 mm) is ultrasonically cleaned with acetone and methanol and then pickled with a 5 wt% sulfuric acid aqueous solution. Then, it was washed with water, dried, allowed to stand in a desiccator and then weighed (weight of clean test piece: A). Add this to the following metal cutting oil (A) at room temperature for 3
After soaking for 1 minute, it is dried in an oven at 100 ° C. for 30 minutes. Then, after leaving it in a desiccator, the undried oil was wiped off with a clean cloth and weighed (oil adhesion weight: B). Then, after immersion cleaning with an aqueous ammonia solution adjusted to pH 9.5 for 15 minutes at room temperature, it is immediately dried in an oven at 100 ° C. for 30 minutes. Then, after leaving it in a desiccator, it was weighed (weight after washing: C). Metal cutting oil used in the test (A) Water-soluble cutting oil (Mitsubishi Petroleum Corporation, trade name: Diamond Rich Cut 101A)

Example 2 Example 1 was repeated except that instead of the aqueous ammonia solution adjusted to pH 9.5 used in Example 1, an aqueous ammonium carbonate solution adjusted to pH 10.0 was ultrasonically cleaned for 15 minutes. I went the same way.

Example 3 The metal cutting oil (A) used in Example 2 was replaced with the following metal cutting oil (B), instead of the ammonium carbonate aqueous solution adjusted to pH 10.0, an aqueous ammonia solution adjusted to pH 12.0. The same procedure as in Example 2 was carried out except that it was used. Metal cutting oil used in the test (B) Water-insoluble cutting oil (Mitsubishi Petroleum Corporation, trade name: Diamond Rich Cut W-12)

Example 4 Example 4 was repeated except that, instead of the ammonium aqueous solution adjusted to pH 9.5 used in Example 1, 1000 ppm of n-butanol was added to an ammonium bicarbonate aqueous solution adjusted to pH 9.0. The same procedure as 1 was performed.

Example 5 Except that a solution prepared by adding 500 ppm of diethanolamine and 1000 ppm of propylene glycol monomethyl ether to an ammonium aqueous solution adjusted to pH 10.0 instead of the ammonium aqueous solution adjusted to pH 9.5 used in Example 1 was used. The same procedure as in Example 1 was performed.

Comparative Example 1 The same procedure as in Example 1 was carried out except that only water was used in place of the aqueous ammonia solution adjusted to pH 9.5 used in Example 1.

Comparative Example 2 The procedure of Example 3 was repeated, except that only the aqueous ammonia solution used in Example 3 and adjusted to pH 12.0 was replaced with water.

Comparative Example 3 Instead of the ammonium aqueous solution adjusted to pH 9.5 used in Example 1, 1000 ppm diethanolamine,
Example 1 was repeated except that a mixed aqueous solution of 500 ppm propylene glycol monomethyl ether, 500 ppm polyoxyethylene lauryl ether, and 1000 ppm nonanoic acid was used.

Comparison of Detergency For Examples 1 to 5 and Comparative Examples 1 to 3, the cutting oil removal rates were calculated by the following formulas and compared, and evaluated according to the following criteria in three stages. Cutting oil removal rate = 100 (oil adhesion amount-remaining amount) / adhesion amount = 100 (BC) / (BA) ○: Removal rate 95% or more Δ: Removal rate 90% or more and less than 95% ×: Removal Less than 90%

Appearance Inspection The appearance of the dried test pieces of Examples 1 to 5 and Comparative Examples 1 to 3 was visually observed, and stains due to oxidation and evaporation residue
The unevenness was evaluated according to the following criteria in four levels. ⊚: Very good with no stains / unevenness due to oxidation or evaporation residue. ○: Excellent with little stains / unevenness due to oxidation or evaporation residue. △: Slightly inferior with stains / unevenness due to oxidation or evaporation residue. Table 1 shows the above results.

[0037]

[Table 1]

[0038]

INDUSTRIAL APPLICABILITY The non-rinse detergent according to the present invention has a good appearance that is clean and has no unevenness or spots on drying even though it is not rinsed with water like the detergent using a flon or chlorine solvent. A product with is obtained.

Claims (3)

[Claims] 1. A non-rinsing detergent comprising an aqueous solution containing an ammonium compound represented by the following formula (1). Embedded image (NH ₄ ) _n X (1) (X is a hydroxyl group, a carbonate group, a bicarbonate group, n is 1 or 2) 2. The non-rinse detergent according to claim 1, which contains a compound represented by the formula (1) and is adjusted so that its concentration is maintained at pH 8.5 or more. 3. A non-rinse cleaning method using the compound represented by the formula (1) and any one of stirring cleaning, ultrasonic cleaning, heating cleaning and spray cleaning.