JPH0433840B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an alkaline cleaning agent, particularly an alkaline cleaning agent for metals and plastics having excellent stability and cleaning properties. Today, plating metals, plastics, etc.
Large amounts of alkaline cleaning agents are consumed in preparatory work such as painting. These alkaline cleaning agents are
Generally, alkali metal hydroxides, neutral salts of alkali metals, chelating agents, various builders and surfactants are blended, and the majority of cleaning agents used today are builder components. It is a powder or fine powder obtained by coating, impregnating, etc. with a surfactant and drying it. However, in addition to being bulky, solid products such as powders and powders have many operational and occupational health problems, such as the difficulty of measuring them during use and the scattering of fine powder when taking them out of containers. On the other hand, liquids have advantages over the former, such as being easy to measure and can be transported through pipes, but on the other hand, surfactants tend to separate and precipitate due to the salt folding effect.
It has manufacturing difficulties in that it is difficult to obtain high-concentration products. The present invention relates to a new detergent composition that solves the above-mentioned problems in liquid alkaline detergents for metals and plastics. Conventionally, as an attempt to stably incorporate surfactants into alkaline aqueous solutions, (1) hydrotropic action (solubility increasing action) on anionic surfactants or nonionic surfactants such as lower alcohols;
How to use. (2) A method to reduce the HLB value of surfactants. and (3) two alkaline cleaning agents (one liquid, one
The other is a method of dividing into liquid or powder. etc. are known. However, in the method (1) that utilizes hydrotropy, problems arise such as a decrease in performance and an increase in foaming properties, especially when an anionic surfactant is added. Furthermore, according to the method (2) of lowering the HLB, cleaning performance is sacrificed. moreover
The division method (3) has a major disadvantage in terms of workability. As described above, all of the known means for preventing precipitation of surfactants are unsatisfactory in their effectiveness, which has hindered the development of liquid detergents. However, as a result of conducting systematic research on means for preventing the precipitation phenomenon in liquid alkaline cleaning agents, the present inventor has recently discovered that many water-soluble polymeric substances are extremely useful for this purpose. It has been found that xanthan gum, carboxymethylcellulose or a salt thereof, and alginate (hereinafter referred to as "water-soluble polymeric material" or simply "polymeric material") exhibit a strong stabilizing effect. Incidentally, water-soluble polymeric substances are generally hydrophilic colloidal substances, and it is well known that the presence of these colloidal substances is effective in preventing precipitation and precipitation of poorly soluble substances, but this is the subject of the present invention. The fact that a strong anti-precipitation effect can be achieved in a strongly alkaline atmosphere and in the presence of a large amount of electrolyte cannot be easily predicted, and is a new finding discovered for the first time by the present inventor. The above water-soluble polymeric substance is present in the composition in an amount of 0.1 to 5.0.
%, preferably in the range of 0.3 to 2.0%.
If it is less than 0.1%, a sufficient stabilizing effect will not be obtained, and if it exceeds 5%, the viscosity of the composition will generally increase and it will become difficult to flow. The liquid alkaline detergent of the present invention contains general components such as an alkaline substance, a nonionic surfactant, a chelate compound, a builder, and water as conventional components in addition to a water-soluble polymeric substance as an essential component. For example, strong alkaline substances such as caustic alkali, alkali carbonate, and sodium silicate are used as alkaline substances, and examples of nonionic surfactants include polyoxyethylene alkylphenols, polyoxyethylene fatty alcohols, and polyoxyethylene fatty acids. , polyoxyethylene acid amide, polypropylene glycol, block polymers of polypropylene glycol, etc. are suitably used. It is preferable for the nonionic surfactant to have a high HLB. In addition, chelate compounds include nitrilotriacetic acid, ethylenediaminetetraacetic acid,
Diethylenetriaminepentaacetic acid or salts thereof are used. Further, as the builder in the present invention, inorganic alkaline salts and neutral salts and organic alkaline salts and neutral substances are preferably used, such as sodium phosphate, sodium hydrogen phosphate, sodium polyphosphate, sodium carbonate, sodium sesquicarbonate,
These include water glass, sodium sulfate, sodium chloride, sodium citrate, fatty acid amide, and sodium naphthalene sulfonate. Examples of the present invention will be shown below, but these are merely illustrative and do not limit the technical scope of the invention. Example 1 A standard liquid alkaline cleaning composition was prepared according to the formulation in Table 1 below.

[Table] The following table -
Various water-soluble polymer compounds were blended as shown in 2. (The amount added is the same for both formulations A and B)

【table】

[Table] * Polyoxyethylene alkyl phenyl
Sodium Salt A of Tersulfate Stability Test Each of the above test materials was left at room temperature (25°C) for 7 days and the stability of each solution was observed. The results were as shown in Table 3 below.

[Table] As shown in Table 3 above, products 1 to 5 of the present invention containing xanthan gum or it, sodium alginate or CMC sodium, CMC-sodium or CMC-sodium, and an anionic surfactant
It is shown that the composition is stabilized when the amount of the polymer compound is within the range of 0.5 to 1.2%. On the other hand, Comparative Products 1 and 2 containing 0.05 or 0.08% xanthan gum or polyvinyl alcohol had insufficient stabilizing effect, and Comparative Products 3 and 4 containing 6% CMC-Na or soluble starch with CMC-Na caused gelation. This indicates the fact that this occurs and the product is unsuitable for use as a product. Incidentally, the xanthan gum used in this experiment contains D-glucose, D-mannose, and D-
Glucuronic acid is linked in a chain, and
CMC is composed of a compound in which only D-glucose is linked in a linear chain, and alginic acid is a linear linkage of D-mannouronic acid, so they are both chemically different. Therefore, it is presumed that the chemical structure of the water-soluble polymer substance will not have much influence on the effectiveness of the invention. In addition, in view of the results of this experiment, the content of the water-soluble polymeric substance in the composition is 0.1% or more and 5% or less, preferably 0.3 to 2.0%.
It would be appropriate to be within the range of Example 2 The following treatments were added to the standard liquid alkaline cleaning composition (Formulation A, but containing no water-soluble polymeric substance) used in the previous example. (A) Comparative product A: 0.5% sodium salt of polyoxyethylene alkyl phenyl ether phosphate was added as a hydrotropic agent. (B) Comparative product B: 1% isopropanol was added as a hydrotropic agent. (c) Comparative product c: HLB of nonionic surfactant is 10
change to. (d) Comparative product d: Separated into builder part and chelate part (granular solid) and surface active part (liquid). Separately, Invention Product 5' was prepared by changing the anionic surfactant in the stabilizer of Invention Product 5 to 4% casein. Comparative products 1 to 2 and products 1 and 5 of the present invention were compared in terms of stability, washability, foaming property, and workability. The results are shown in Table 4 below.

[Table] As shown by the above experimental results, Comparative Product A, in which an anionic surfactant was added as a hydrotropic agent, had poor stability, large foaming properties, and poor cleaning properties. Comparative product B, in which isopropanol was added as a hydrotropic agent, had extremely poor stability and was found to have virtually no hydrotropic effect on high-concentration liquid detergents such as the present composition. Comparative product C, which is a nonionic surfactant with a lower HLB, has significantly poor cleaning performance, as is commonly believed.
This proves the correlation between HLB and cleanability. Moreover, the stability has not improved that much. It goes without saying that the comparative product 2, in which the builder part and the surfactant are separated, has good stability, but it goes without saying that the workability is inferior. Contrary to the above, invention products 1 and 5' containing polymer compounds
All of them are stable, their cleaning properties are equal to or better than comparative product 2, their foaming properties are not so large, and they are excellent in workability, so they are excellent as liquid alkaline cleaning agents. In addition, invention 1
The superior detergency of 5' compared to 5' is probably related to the ability of xanthan gum to form large emulsified particles. As detailed above, the present invention completely solves the stability disadvantages of liquid detergents for metals and plastics, and maximizes the advantages of liquid detergents. This brings great benefits to detergent users.

Claims (1)

[Scope of Claims] 1. A stable liquid alkaline cleaning agent for metals and plastics, characterized in that it contains a water-soluble polymeric substance selected from xanthan gum, carboxymethyl cellulose or its salt, and alginate as a stabilizer. 2 The water-soluble polymer substance is contained in the cleaning composition at a concentration of 0.1
Alkaline detergent according to claim 1, present in a proportion of ~5%, preferably 0.3-2%.