JPS5951598B2 - Method for preventing deposits, drying marks and thin film formation during final rinsing operation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing deposits, dry marks and film formation on glass, lacquered or metal surfaces during final rinsing operations in hard water.

If glass, rack-coated surfaces or metal surfaces are washed in acidic, neutral or alkaline conditions, followed by a final rinse with hard water, as is the case, for example, in automobile washing or passenger train cleaning, glass, rack-coated surfaces or metal surfaces may be damaged. Deposits, dry marks or films form on the surface, making the surface unsightly. The causes of such drying marks, deposits and films are, on the one hand, salts contained in the water, and on the other hand, residues of the cleaning solution. Hard water is generally used because fully desalinated water is not available in sufficient quantities for the final washing operation, yet a clear surface finish free of deposits and film formation is desired. J I tried experimenting with a clear rinse like the one used in dishwashers, but with no results.

Use of hard water resulted in unsightly deposits and film formation.
Furthermore, clear rinses are often adjusted to be acidic.
Particularly in the case of cleaning passenger trains, this acid causes the formation of iron, salts, or iron complexes, which pose a problem. By the way, it has been found that by using the method of the present invention, a glass surface, a rack-coated surface, or a metal surface without deposits, streaks, or thin film formation can be obtained even when rinsed with hard water. The method involves the use of a polymer containing monovalent cations or one or more salts of lignin sulfonic acid containing magnesium at a concentration of 0.02 to 0.04% by weight/hardness.
It is characterized in that the surface to be cleaned is treated with a solution having an H value of 4 to 8 at a temperature of 4 to 40°C. As salts of ligninsulfonic acid with monovalent cations it is possible to use alkali metal salts, such as in particular the sodium and potassium salts.

Ammonium also falls under the meaning of the present invention as a l-valent cation. Furthermore, magnesium salts of ligninsulfonic acid are also suitable for the process according to the invention. The concentration of lignin sulfonate should be determined by the hardness of the rinsing water used.
It will range from 2 to 0.04% by weight/hardness. In one advantageous embodiment of the process according to the invention, a surfactant is additionally added to the final washing solution in a concentration of 1-15%, based on the lignin sulfonate used.

In this surfactant-containing final washing solution, the concentration of lignosulfonate can be from 0.004 to 0.04%/hardness. Suitable surfactants are fatty acid diethanolamides, alkylbenzole sulfonates, fatty alcohol polyglycol ethers and alkylphenol polyglycol ethers, or mixtures thereof.

In the case of polydarycol ethers, those containing 0.25 to 0.6 glycol groups per carbon atom of the hydrophobic molecule are suitable. The pH value of the solution should be in the range 4-8.

Add salts and surfactants to the final washing solution to adjust the pH.
If the value range cannot be reached, the desired value is adjusted by adding small amounts of alkali or acid. The final rinsing is generally carried out at the respective ambient temperature;
℃ has proven to be an advantageous temperature range.

The method described above makes it possible to obtain surfaces free of deposits, streaks and film formations, for example on glass surfaces, lightly coated surfaces or metal surfaces, even in the case of final washing with hard water.

This means that, for example, when passenger trains that have been cleaned with alkaline or acidic liquids are washed in such a way, perfectly clear windows are obtained without the formation of films or streaks, and also the lightly coated or steel surfaces of the car body are thoroughly cleaned. Shows a spotless appearance. When a similarly cleaned car is finally rinsed with the solution according to the invention, no stripes or streaks appear.
It has been demonstrated that clear window panes without markings and completely mark-free easily coated surfaces, chrome and aluminum parts are obtained. Quantities stated in the following examples are in % by weight, unless otherwise stated.

Example 1: Washing a car with a weak alkaline detergent using a high-pressure device,
It was washed with water with a hardness of 16°.

Subsequently, the same car was heated to a temperature of 10°C, and 0.12% of sodium lignin sulfonate and 0.006% of a nonionic surfactant (addition product of 3 moles of ethylene oxide to decyl alcohol) were added to water with a hardness of 16°. It was washed with a solution containing a pH value of 6.0 and kept at a temperature of 10° C., and then dried in the air. The automobiles washed and dried in this manner showed no deposits, streaks or film formation on the window glass, chrome and aluminum parts, or on the lightly coated surfaces.

h) In water with a hardness of 16°, there is 0.0 of ridanine sulfonate.
When a solution containing only 3% and 0.0015% of the addition product of 3 moles of ethylene oxide decyl alcohol was used for the final cleaning, the streaks and film formation were clearly visible after drying the car.

Example 2 A window glass was cleaned with acidic cleaning agent to remove dust and sediment, and then rinsed with water having a hardness of 16°.

A final washing was then carried out at a temperature of 15° C. in a solution containing 0.5% of sodium lignosulfonate with a degree of sulfonation (number of sulfonic acid groups/phenylpropane units) of approximately 0.17 in water with a hardness of 16°. Summer. The pH value of the solution was 7.5. After air drying, the window glass was completely clear, with no streaks, films or spots. Sodium lignin sulfonate in water with a hardness of 4°. (Sulfur content 6.5%,
Na.

O content 10%, glycose content 10% or less, sugar content 4%
Below) 0.02% and decyl alcohol ethylene oxide 3
The same results were obtained when the final washing was carried out with a solution containing 0.001% molar addition product. When low lignin sulfonate and wetting agent concentrations, such as in the second run of Example 2, were applied to 16° hardness water, significant unsightly film formation was observed on the lower half of the window glass after drying.

Example 3 Dust and sediments are removed from window glass with acidic cleaning agent, and the hardness is 1
Rinse with 6° water.

A final washing was then carried out at a temperature of 19 DEG C. with water having a hardness of 16 DEG to which 0.1% sodium ligninsulfonate had been added. The pH value of the solution was 7.0. After drying, a thin film formation was still observed on the lower half of the window glass. On the other hand, if 0.005% of a nonionic surfactant (addition product of 3 moles of ethylene oxide to decyl alcohol) was added to the final washing solution, the window glass became clear.
Films, streaks and spots disappeared. A final rinse with 16° hardness water to which only 0.005% of the addition product of 3 moles of ethylene oxide to decyl alcohol was added resulted in an evenly distributed thin film on the window glass after drying. . Example 4 Window glass was cleaned and scrubbed as described in Example 2.

The final washing was carried out with 22° hardness water containing 0.25% sodium ligninsulfonate and 0.02% coconut oil fatty acid diethanolamide. The pH value of the solution was adjusted to 4.5. After drying, a clear glass surface without films and streaks was obtained. 0.2% of magnesium lignosulfonate (approximately 7.5% MgO) and 0.01% of addition product of 3 moles of ethylene oxide to decyl alcohol in 16° hardness water.
Similarly, clear window glass completely free of streaks and thin films was obtained when final washing was carried out with a solution containing .

When calcium lignosulfonate was used instead of magnesium lignosulfonate at a concentration of 0.2-0.4%, a still obvious thin film was seen on the window glass.

Potassium lignin sulfonate 0.2~ in water with hardness of 16°
Addition product of 5 moles of ethylene oxide to nonylphenol with 0.4% or 4 moles of ethylene oxide to sodium dodecylbenzole sulfonate and nonylphenol
Even when the final cleaning was carried out with a solution to which 0.02% of the mixture with the molar addition product was added, a clear window glass completely free of films, spots and streaks was obtained.

Claims (1)

[Scope of Claims] 1. A method for preventing the formation of deposits, drying marks, and thin films on glass surfaces, rack-coated surfaces, or metal surfaces during final washing with hard water, comprising monovalent cations on the same surfaces. or one or more salts of lignin sulfonic acid containing magnesium at a) concentration of 0.02 to 0.04% by weight/hardness. or advantageously the same salt b) 0.004 to 0.04% by weight/
pH value 4, containing a hardness concentration and additionally a surfactant in a concentration of 1 to 15% by weight, based on the lignin sulfonate.
A method for preventing deposits, drying marks and film formation in the final rinsing operation, characterized by treatment with a solution of 1 to 8 at a temperature of 4 to 40°C. 2 The solution contains fatty acid diethanolamide and/or aliphatic alcohol having 0.25 to 0.6 glycol groups per carbon atom of the hydrophobic molecule moiety as a surfactant, or an alkylphenol polyglycol ether and/or an alkylbenzole sulfonate. A method according to claim 1 containing: