JPH04120199A - Aqueous detergent - Google Patents

Abstract

PURPOSE:To obtain an aqueous detergent having de-fatting power and permeating force equal to those of a chlorine-based solvent, free from metal corrosiveness and environmental pollution by blending a specific surfactant with sodium carbonate and sodium silicate in a specific ratio. CONSTITUTION:The objective detergent comprising (A) >=5wt.% surfactant containing >=80wt.% nonionic surfactant mixture of (i) a polyoxyethylene lauryl ether having 8-10 average addition mols of ethylene oxide and (ii) a polyoxyethylene lauryl ether having 3-5 average addition mols in a ratio of the component (i)/the component (ii) of 1-4 by weight, (B) 0-40wt.% sodium carbonate and (C) <=60wt.% sodium silicate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an aqueous cleaning agent used for degreasing and cleaning metals, ceramics, glass, plastics, and the like.

[Prior art] Conventionally, as industrial degreasing cleaners for metals, ceramics, glass, plastics, etc., there have been water-based cleaners such as alkaline cleaners, and solvent-based cleaners such as Ll, L)lichloroethane. Cleaning agents are used.

Alkaline cleaning agents include surfactants such as nonionic surfactants typified by polyoxyethylene alkyl phenyl ether, anionic surfactants typified by sodium alkylbenzene sulfonate, sodium carbonate, sodium silicate, sodium phosphate, etc. Alkali metal salts, sodium tripolyphosphate, chelating agents such as EDTA, benzotriazole, amines, rust preventive agents such as sodium nitrite, etc. are appropriately blended. Its composition is, for example, "Precision Cleaning Technology" by Tsuji Kozo, Engineering Book, pages 117-120.
, Articles to be cleaned as described in "Precision Cleaning Technology Manual" New Technology Development Center pages 50 to 56, edited by Noboru Tsuji,
Various types have been proposed depending on the metal and dirt. However, its degreasing power and penetrating power are inferior to those of chlorinated solvents such as 1,1.1-)lichlorethane, so in actual application fields it is difficult to clean articles with simple structures or to control the amount of residual oil after cleaning. The main focus is on fields where people don't really care.

On the other hand, chlorinated solvents such as LLI-trichloroethane have excellent degreasing power and penetrating power, and can be applied to all types of degreasing such as cutting oil, drawing oil, and press oil. It is used in fields that require a high degree of skill.

However, in recent years, environmental problems such as groundwater contamination, air pollution, and ozone layer depletion due to chlorinated solvents have become more apparent, and the industry has begun using cleaning agents to replace them.
Conventional alkaline cleaning agents are being applied.

[Problem to be solved by the invention]

However, conventional alkaline cleaners have inferior degreasing and penetrating power compared to chlorinated solvents, especially when cutting oil, drawing oil, high viscosity press oil, etc. are attached to narrow gaps or details. It cannot be applied when the problem is a very small amount of residual oil on the surface of an article.

In order to increase the degreasing power and penetrating power, it is possible to use a large amount of nonylphenyl-based nonionic surfactant, which has high degreasing power and penetrating power, but this surfactant has low biodegradability and is difficult to treat in wastewater treatment. This is undesirable as it becomes difficult and pollutes rivers and the sea. Examples of surfactants with good biodegradability include soap, alkyl ether type nonionic surfactants, alkyl ether sulfonates, α-olefin sulfonates, etc., but nonylphenyl type surfactants have better degreasing power and penetration power. No one has been found that is superior to nonionic surfactants.

In addition, since conventional alkaline cleaning agents are corrosive to metals, they are often mixed with corrosion-damaging agents, such as organic corrosion inhibitors such as amines, and inorganic corrosion elongation agents such as nitrites. There is a need. Such corrosive agents are toxic and may pollute the environment if contained in wastewater.

As for corrosion inhibitors, safer carboxylic acid amide-based agents have been proposed (Japanese Patent Laid-Open No. 60116791).
Such nitrogen compounds lead to eutrophication of lakes, marshes, and bays, and are unfavorable from the viewpoint of environmental protection.

Therefore, there is a strong need in the industry for a water-based cleaning agent that has degreasing and penetrating power comparable to chlorinated solvents, is not corrosive to metals, and does not pollute the environment.

[Means to solve the problem]

As a result of extensive studies, the present inventors have found that the above problem can be solved by using a specific nonionic surfactant in a specific ratio and using specific amounts of sodium carbonate and sodium silicate, and have developed the present invention. It was completed.

That is, in the present invention, as a detergent component excluding water, (a) the average number of added moles of ethylene oxide is 8 to 1;
Weight ratio (1) of polyoxyethylene lauryl ether nonionic surfactant (1) having 0 mole and polyoxyethylene lauryl ether nonionic surfactant (2) having an average added mole number of ethylene oxide of 3 to 5 moles / (
2) contains 5% by weight or more of a surfactant consisting of 80% by weight or more of a nonionic surfactant having 1 to 4, and (b) 0 to 40% by weight of sodium carbonate and 60% by weight or less of sodium silicate. It is a water-based cleaning agent characterized by:

The nonionic surfactant used in the present invention is obtained by adding ethylene oxide to lauryl alcohol, a straight chain alcohol with 12 carbon atoms, obtained by distilling an alcohol mixture obtained by reducing natural coconut oil etc. It will be done. The number of moles of ethylene oxide added is on average 8 to 10 moles, preferably 9 moles, and 3 to 5 moles, preferably 4.2 moles. The mixing ratio of two types of surfactants with different numbers of added moles of ethylene oxide is 8 to 10 moles of adduct on average/3 on average.
~5 mole adduct = adjusted as appropriate between 1 and 4. The preferred ratio is 2. If this ratio is less than 1, if an alkali salt is added when the concentration of detergent components is high, the detergent aqueous solution will become cloudy and its viscosity will become high, and the surfactant will be salted out, which is not preferable. Moreover, if this ratio is larger than 4, the degreasing power and the penetrating power will decrease, which is not preferable.

In the present invention, 80% by weight of the above-mentioned specific nonionic surfactant
A surfactant consisting of the above is used. If the proportion of the above-mentioned specific nonionic surfactant in the surfactant is less than 80% by weight, it is not preferable because the degreasing power and the penetrating power decrease.

In the present invention, 5% by weight or more of the above-mentioned specific surfactant is used in the cleaning agent component excluding water (hereinafter, unless otherwise specified, weight% refers to the weight% in the cleaning agent component excluding water). say). Preferably it is 10 to 90% by weight. If the amount added is less than 5% by weight, the degreasing power and penetrating power will decrease, which is not preferable.

Sodium carbonate and sodium silicate used in the present invention are
Due to the synergistic effect with the surfactant used in the present invention, it is used to enhance degreasing power and penetrating power, and to inhibit metal corrosion. By using sodium silicate alone or in combination with sodium carbonate and sodium silicate, high degreasing properties and metal stability against iron, copper, aluminum, zinc, etc. can be obtained. The amount of sodium carbonate added is 0 to 4.
0% by weight, and 60% by weight or less of sodium silicate.

The total amount of sodium carbonate and sodium silicate is preferably 10 to 90% by weight. Further, in order to prevent corrosion of aluminum in an alkaline aqueous solution, it is preferable to use 30 to 60% by weight of sodium metasilicate as the sodium silicate. On the other hand, in order to avoid silicic acid precipitation when the cleaning agent ages, as much sodium silicate as possible is added (if not, 2 to 10% by weight of No. 3 sodium silicate is preferably used).

These cleaning agent components are used as a degreasing cleaning liquid in the form of an aqueous solution. The cleaning agent component concentration at that time is usually 0.1 to 5.
Weight%. The concentration of the cleaning agent component is appropriately adjusted depending on the cleaning method, the cleaning article, the cleaning conditions such as dirt, etc.

In the present invention, other known detergent additives such as sodium glyconate, chelating agents such as EDTA, inorganic builders such as phosphates and sulfates, benzotriazoles,
Corrosion inhibitors such as amines and nitrites, self-emulsifying silicones, foam suppressants such as propylenoxide ethyleneoxide block polymers, hydrotropic substances such as t-butylbenzoic acid and xylene sulfonic acid, etc. are appropriately blended and used. It is also possible.

〔Example〕

The present invention will be further explained below with reference to Examples.

Examples 1 to 7 and Comparative Examples 1 to 14 The cleaning agents shown in Table 1 were blended and the following tests were conducted. The results are shown in Table 2.

1. Degreasing power and penetration power test 30 mesh stainless steel gold Y1 (60 x 40 mm) was impregnated with the following metal working oil and heated at 100°C for 30 minutes.

Add 5% of this to a cleaning solution containing 2% by weight of cleaning ingredients excluding water.
It was washed by immersing it at 0°C for 3 minutes, and the degreasing rate was calculated from the amount of oil adhered before and after washing, and compared with the case of degreasing with 1.1.1-trichloroethane.

Metalworking oil used in the test Cutting oil: Unicut 35 [manufactured by Nippon Oil ■, product name] Drawing oil: Daphne Master Draw 533WD [manufactured by Idemitsu Kosan ■, product name] Breathing oil: Unipres ER500 [manufactured by Nippon Oil ■, product name] ] 2. Metal corrosivity test 13X30 in a cleaning solution with a cleaning agent component of 2% by weight excluding water.
After immersing the X2M metal test piece at 40°C for 3 days, the appearance and weight change were observed.

3. Regarding the cleaning agents of Biodegradability Test Examples 1 to 7 and Comparative Examples 13.14,
BOD was measured by the method described in JIS K 0102 (1986), and the ratio to theoretical oxygen demand (ThOD), BOD5/ThOD, was determined.

If this ratio is 0.5 or more, it is easy to decompose.

〔Effect of the invention〕

The cleaning composition of the present invention has degreasing power comparable to that of chlorinated solvents,
It is excellent in that it has penetrating power, is almost non-corrosive to metals, does not contain components that pollute the environment, and is easily decomposed by microorganisms.

Claims (1)

[Claims] 1. The cleaning agent components excluding water are (a) a polyoxyethylene lauryl ether nonionic surfactant (1) having an average added mole number of ethylene oxide of 8 to 10 moles and a polyoxyethylene lauryl ether nonionic surfactant (1) having an average added mole number of ethylene oxide of 3 to 5 moles. The weight ratio (1)/(2) of polyoxyethylene lauryl ether nonionic surfactant (2) is 1
5% by weight or more of a surfactant consisting of 80% by weight or more of a nonionic surfactant of ~4, and (b) 0 to 40% by weight of sodium carbonate and 60% by weight or less of sodium silicate. Water-based cleaning agent.