JPH11269491A - Scale cleaning composition - Google Patents

Abstract

(57) Abstract: 1 to 20% by weight of a monoalkanolamine, 0.1 to 10% by weight of a nonionic surfactant and 0.1 to 5% by weight of an organic acid are dissolved in water, and the pH is adjusted to 9%. 0.0-12.
5. A descaling composition according to 5. [Effect] Since the pH is low, the paint surface is not adversely affected, the paint surface is not stained, the gloss is not generated, and a large amount of monoalkanolamine is blended without fear of adverse effects on the paint surface. Therefore, the scale can be efficiently removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scale cleaning composition for cleaning and removing scales adhering to painted surfaces of automobiles.

[0002]

2. Description of the Related Art Conventionally, for washing automobiles and the like, it has been widely practiced to mechanically wash a car through a portal type car washer or to wash a car by hand washing. Then, repeated car washing causes stains to adhere to the painted surface and become dirty. Therefore, it is necessary to remove the scales at the time of car washing.

In order to remove scale, a cleaning agent containing an abrasive is sometimes used. However, since this type of cleaning agent often damages a painted surface, in recent years a type containing no abrasive is used. Is increasingly used.

[0004]

However, the type of cleaning agent containing no abrasive is a combination of an alkali and a surfactant. In order to efficiently remove strongly adhered scale, the cleaning agent must have a pH value. To increase the activity of the surfactant.

[0005] For this reason, generally, this type of descaling agent is p
It is a strong alkali of H13 or more, which is dangerous if it adheres to the worker's body, is a safety problem, and it is difficult to use materials such as painted surfaces and other metals, plastics and rubbers used in various parts of the vehicle. Had an adverse effect.

[0006] In particular, when this kind of strong alkaline descaling agent is used on a painted surface, it is extremely effective in removing scales sticking to the painted surface, but the alkali is difficult to remove the oil component adhering to the painted surface. In addition, since the active ingredients such as wax, surface treatment agent and the like are also eroded, the coated surface is deteriorated and becomes rough and loses its luster, resulting in a phenomenon called “glossy blur”.

In particular, when a highly alkaline descaling agent is used on a painted surface that has been deteriorated over a number of years and is barely glossy with wax, the alkali penetrates into the wax and the painted surface is degraded. It acts on the surface and further promotes the deterioration, and it becomes difficult to recover the gloss any longer even if wax is applied again.

The present invention has been made in view of the above circumstances, and is directed to a descaling detergent comprising a combination of an alkali and a surfactant, which can exert sufficient detergency even in a region having a lower pH. It is an object of the present invention to provide a scale cleaning composition which is safe for workers and has no adverse effect on painted surfaces and the like.

[0009]

According to the present invention, monoalkanolamine of 1 to 20% by weight, nonionic surfactant of 0.1 to 10% by weight and organic acid of 0.1 to 5% by weight are dissolved in water. It is characterized by dissolving and adjusting the pH to 9.0 to 12.5. In this descaling composition, it is preferable to add 1 to 10% by weight of a lactic acid ester.

The monoalkanolamine includes monoethanolamine, N, N-dimethylethanolamine, N-methylethanolamine, N- (β-aminoethyl) ethanolamine, N, N-dibutylethanolamine, monoisopropanolamine. Or 2-amino-
Methylpropanol is suitable.

The nonionic surfactants include polyoxyethylene alkyl ethers (alkyl groups having 12 to 18 carbon atoms, ethylene oxide addition moles = 3 to 1).
5), polyoxyethylene alkyl phenyl ether (alkyl group having 8 to 12 carbon atoms, ethylene oxide addition mole number = 3 to 15) or alkyldimethylamine oxide (alkyl group having 10 to 14 carbon atoms) is suitable.

As the organic acid, citric acid, oxalic acid, malic acid, malonic acid, succinic acid, tartaric acid, maleic acid, lactic acid or glutaric acid are suitable.

When a lactic acid ester is added as described above, the lactic acid ester is preferably an ester of lactic acid and an aliphatic alcohol having 1 to 5 carbon atoms.

[0014] The present invention comprises a combination of a monoalkanolamine as an alkali for dissolving scale and a nonionic surfactant for permeating the alkali into the scale,
The monoalkanolamine is sufficiently mixed to secure the detergency against scale, and the pH is lowered by adding an organic acid as a buffer to reduce the adverse effect on the painted surface.

As the alkali in the present invention, a monoalkanolamine which is excellent in descaleability and has high safety for a painted surface is used. Examples of monoalkanolamines include monoethanolamine, N, N-dimethylethanolamine, N-methylethanolamine,
-(Β-aminoethyl) ethanolamine, N, N-dibutylethanolamine, monoisopropanolamine, 2-amino-methylpropanol and the like.

Of these, monoethanolamine, monoisopropanolamine, 2-aminomethylpropanol, and the like are particularly excellent in washing properties against water scale,
preferable. These monoalkanolamines may be used alone or in combination of two or more.

The amount of the monoalkanolamine is from 1 to
20% by weight is suitable. If it is less than 1% by weight, the solubility in water scale is insufficient and the cleaning power is poor. On the other hand, if the content exceeds 20% by weight, even if the pH is suppressed, the action as an alkali is strong, which may adversely affect various parts of the automobile such as a painted surface.

In the present invention, a nonionic surfactant is used as a surfactant for penetrating the monoalkanolamine into the scale. Examples of the nonionic surfactant used in the present invention include polyoxyethylene alkyl ether (carbon number of alkyl group = 12 to 1).
8, ethylene oxide added moles = 3 to 15), polyoxyethylene alkyl phenyl ether (alkyl group carbon number = 8 to 12, ethylene oxide added moles = 3 to)
15) or alkyldimethylamine oxide (alkyl group having 10 to 14 carbon atoms) is suitable. These surfactants can be used alone or in combination of two or more.

The compounding amount of the nonionic surfactant is from 0.1 to
10% by weight is suitable. If the amount is less than 0.1% by weight, the monoalkanolamine cannot be sufficiently penetrated into the scale, resulting in poor detergency. On the other hand, if it exceeds 10% by weight, the monoalkanolamine as an alkali has too high a penetrating power, which may adversely affect the painted surface.

The present invention is characterized in that, in the combination of the above monoalkanolamine and a nonionic surfactant, an organic acid as a buffer is blended to lower the pH.

The organic acids used in the present invention include:
Citric, oxalic, malic, malonic, succinic,
Mention may be made of tartaric acid, maleic acid, lactic acid or glutaric acid. In particular, even when the pH is kept low by blending a large amount, citric acid, malonic acid, succinic acid or oxalic acid is preferable as a substance capable of maintaining the performance of removing scale by alkali, and citric acid and malonic acid are more preferable. ,
The best results have been obtained.

The content of these organic acids is 0.1
About 5% by weight is appropriate. If it is less than 0.1% by weight, the pH can hardly be suppressed, and the adverse effect of alkali cannot be prevented. If it exceeds 5% by weight,
If the pH is excessively suppressed, there is a possibility that the detergency against scale may decrease.

According to the present invention, there is provided a combination of the above monoethanolamine and a nonionic surfactant, wherein an organic acid is added as a buffer, and the pH of the combination is 9%.
~ 12.5. When the pH is less than 9, the washing property of the scale by alkali becomes insufficient, and
Exceeds 12.5, an adverse effect on the painted surface or the like due to alkali occurs.

In the present invention, the addition of a lactic acid ester further improves the detergency against scale.
Better results are obtained. As the lactic acid ester, an ester of lactic acid and an aliphatic alcohol having 1 to 5 carbon atoms is preferable, and examples thereof include methyl lactate, ethyl lactate, propyl lactate, and butyl lactate. These may be used alone or in combination. be able to.

The amount of the lactic acid ester is 1 to 10
A suitable amount is about weight%. If it is less than 1% by weight, the effect of adding the lactic acid ester is hardly obtained. In addition, since lactic acid esters are insoluble in water, if they are added in a large amount exceeding 10% by weight, they cannot be sufficiently emulsified in water and are easily separated.

In the present invention, in addition to the above components, a thickener, a preservative, a rust preventive, and the like can be appropriately compounded if necessary.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.

[Preparation of test piece] 100 mm × 200
A commercially available solid wax was applied to a white painted plate having a size of 0.5 mm and baked with acrylic melamine, and then coated with
° Adjust to about 90 with a gloss meter and leave it outdoors for about 2
Exposure was carried out for a month to give a gloss of about 60. Thereafter, dirt attached to the coated plate by outdoor exposure was lightly washed away with water, and subjected to a test in a state where scale stains were left.

[Preparation of descaling agent] Each component was dissolved in water according to the formulation shown in each of Examples and Comparative Examples in Table 1 to prepare a descaling agent. The pH of the obtained descaling agent was measured, and the stability of the mixed state of the solution was visually determined.

[Test method] Descaling performance The descaling agent prepared in each of the examples and comparative examples was applied to the surface of the test piece to which the scale was formed by the above-described method, and washed with water after 30 seconds. The performance of removing scale from the pieces was visually determined.

[0031]

Deterioration of Paint The descaling agent of each Example and Comparative Example was applied to the surface of the test piece to which the above-mentioned scale was adhered, and peeled, stained, and swollen on the painted surface after heating at 50 ° C. for 30 minutes. The presence or absence of such abnormalities was visually determined.

Judgment criteria:: No change △: Slight stain occurred on the painted surface ×: Stain occurred on the painted surface and deterioration was observed

[Test Results] The results of the tests are shown in Table 1.

[0035]

[Table 1]

[0036]

The descaling composition of the present invention comprises a combination of a monoalkanolamine as an alkali and a nonionic surfactant as a surfactant, which is mixed with an organic acid as a buffer to adjust the pH. It is kept low.

Therefore, in the present invention, the monoalkanolamine as an alkali is penetrated into the scale by the nonionic surfactant, and the monoalkanolamine effectively dissolves the scale as the alkali.

If both are used alone, even if the amount of the monoalkanolamine is small, it shows extremely high alkalinity and adversely affects the painted surface. However, in the present invention, an organic acid as a buffer is individually used. The addition lowers the pH to reduce the effect on the painted surface.

[0039]

Thus, according to the descaling composition of the present invention, the pH is as low as 9 to 12.5, so that it does not adversely affect the painted surface of automobiles and the like, and the painted surface is not stained or glossy. This does not occur, and a large amount of monoalkanolamine can be blended without worrying about such a bad influence on the painted surface, so that water scale can be efficiently removed.

Claims (6)

[Claims] 1. A solution of 1 to 20% by weight of a monoalkanolamine, 0.1 to 10% by weight of a nonionic surfactant and 0.1 to 5% by weight of an organic acid in water and adjusting the pH to 9.0 to 12.
A scale cleaning composition, characterized in that the composition is 5. 2. A scale preparation composition comprising the lactate composition according to claim 1 and 1 to 10% by weight of a lactic acid ester. 3. The monoalkanolamine is monoethanolamine, N, N-dimethylethanolamine,
The method according to claim 1, wherein the compound is N-methylethanolamine, N- (β-aminoethyl) ethanolamine, N, N-dibutylethanolamine, monoisopropanolamine or 2-amino-methylpropanol. 4. Descale cleaning composition 4. The nonionic surfactant is a polyoxyethylene alkyl ether (the alkyl group having 12 carbon atoms).
-18, ethylene oxide addition moles = 3-15), polyoxyethylene alkyl phenyl ether (alkyl group carbon number = 8-12, ethylene oxide addition moles =
3 to 15) or alkyldimethylamine oxide (carbon number of alkyl group = 10 to 14), the scale composition according to claim 1, 2 or 3. 5. The method according to claim 1, wherein the organic acid is citric acid, oxalic acid, malic acid, malonic acid, succinic acid, tartaric acid, maleic acid, lactic acid or glutaric acid.
The descaling composition according to 2, 3, or 4 6. The method according to claim 1, wherein the lactic acid ester is lactic acid and has 1 to 1 carbon atoms.
The descaling composition according to claim 2, wherein the composition is an ester with an aliphatic alcohol of No. 5.