KR900003377B1 - Method to make a cleaning solution for a metal sheet - Google Patents

Abstract

A cleaning soln. for metal sheet comprises water 64 wt.%, sodium carbonate 0.5 wt.%, phosphoric acid 0.5 wt.%, nonylphenol 10 wt.%, and 1,1,1-trichloroethane 25 wt.%. The cleaning soln. shows pH 6.7, and is useful for removing rust, oil, scale, etc. on a metal sheet.

Description

Manufacturing method of washing liquid of metal plate

The present invention relates to a method for preparing a cleaning solution for a metal plate, characterized in that a nonionic surfactant solution is formulated with a cleaning solution of pH 6.7 by mixing carbonates such as sodium carbonate and phosphoric acid (H ₃ PO ₄ ).

SUMMARY OF THE INVENTION An object of the present invention is to provide a metal plate cleaning liquid capable of effectively removing and cleaning rust, scale organic decay fat, and the like deposited on various metal plate surfaces with a spray cleaning solution. In general, in cleaning the metal surface, acid cleaners such as hydrochloric acid, acetic acid, phosphoric acid, sulfoic acid, citric acid, and oxalic acid are used to remove black rust, iron oxide, and scale scale generated on the metal surface according to the cleaning purpose. It is cleaned by using and alkaline cleaning agents such as caustic soda, sodium carbonate and boron are used to remove various organic corrosive oils and fats on metal surface.

At this time, the pH of the acidic detergent is about 5 strong acids, in the case of alkaline detergents weak alkaline of about 11.8 pH, of course, nonionic surfactants are additionally or used as a subject. However, the surface of various transportation equipment, machine tools, or steel plates to be painted is rarely stained with a limited kind of soil so that it can be cleaned with an acidic or alkaline cleaner alone, and is contaminated with complex various forms and materials. In addition, it is preferable to use both cleaning agents sequentially in order to perform a complete cleaning process. However, it is very cumbersome, and in particular, the procedure in the alkali treatment after acid treatment is complicated, and the work is cumbersome, so that the efficient cleaning operation is difficult.

In order to correct these problems, the present invention mixes the subject of an acidic detergent and the subject of an alkaline detergent, but combines the carbonate and phosphoric acid in a condition that can have a reversible reaction. Depending on the reaction, it functions as a weak alkaline agent, and as a single detergent, it is possible to clean a wide range of metal plates that exhibit both acidic and alkaline properties.

Hereinafter, the present invention will be described in detail with reference to Examples.

Sodium Carbonate (Na ₂ CO ₃ ) 0.5% (weight ratio)

Phosphoric acid (H ₃ PO ₄ ) 0.5% (weight ratio)

NP ¹⁰ (nonylphenol, C ₉ H ₁₉ C ₆ H ₄ OH) 10% (weight ratio)

Valtan CF (1,1, l-trichloroethane, CH ₃ CC ₁₃ ) 25%

64% of water

100% in total

Sodium carbonate and surfactant (NP10 and valdecane CF) are first added to the predetermined amount of water in the above composition, stirred and dissolved, and then added and stirred with phosphoric acid to place in a container. The container is 20 liters or 100 liters for convenience.

Nonylphenol (NP10), which is the cleaning agent, is a colorless to embarrassing liquid with a slight phenolic smell.

Normally, it is a detergent that dissolves in organic solvents and does not cause corrosion in mild steel. In addition, 1,1,1-trichloroethane is a colorless, transparent, rare, liquid with a characteristic mild sweet smell. It is mainly used for cleaning room temperature and steam. Suitable for dry cleaning solvents and aerosols.

The specification of this invention is as follows.

Color: white

Liquid

pH: 6.7

Composition: nonionic

Odor: Slightly south

Building: 15-25

Cleaning time: 15-25 seconds

Degreasing force: 95 ± 5%

Temperature: Room temperature

The cleaning agent of the present invention removes fats, oils, rusts, scales and various organic corrosive scales contaminated on various metal surfaces by spray washing.

That is, the presence of sodium carbonate liquid is alkaline at pH 11.8 and the presence of phosphoric acid is pH 5, but by the reaction of sodium carbonate and phosphoric acid, the pH is about 6.7. At this time, carbonate is separated from carbonic acid and combined with phosphoric acid to form phosphate. Therefore, it becomes weakly acidic. However, since alkaline salts and phosphoric acid are blended in the composition of the cleaning agent of the present invention, degreasing by alkaline and removal of organic contaminants are good due to the characteristics of both. It is also removed from rust, scale and scale of metal surfaces by phosphoric acid.

Accordingly, there is an effect that the various impurities contaminated on the metal surface due to the absence of corrosion of the metal plate can be more conveniently and reliably removed by a single detergent.

Claims (1)

In the degreasing cleaner on the metal surface, the composition is prepared by weight ratio of 64% of water, 0.5% of sodium carbonate, 0.5% of phosphoric acid, 10% of nonylphenol, and 25% of 1,1,1-trichloroethane. Preparation of washing liquid.