JPS5831088A - Improvement for surface of steel material - Google Patents

Abstract

PURPOSE:To maintain the surfaces of steel materials cleanly and to prevent their oil staining by treating the steel materials with an aq. soln. prepd. by adding the comps. expressed by the specific formula and ethylenediaminetetraacetic acid to a water soluble org. corrosion preventing agent. CONSTITUTION:The comps. expressed by the formula (X is hydrogen atoms, hydroxyl groups, alkyl groups, carboxyl groups or nitro groups) or their alkali metals, ammonium salts or amine salts and >=1 kind waterials selected among ethylenediaminetetraacetic acid or its alkali metal salts, ammonium salts or amine salts are added to a water soluble org. corrosion preventing agent and steel materials are treated with the soln. prepd. in such a way. Known corrosion preventing agents are used. For example, pyridine-2-carboxylic acid, etc. are used as the compds. of the formula at about 0.01-5wt% concn., and the ethylenediaminetetraacetic acid is also used at about 0.01-5wt% concn. The soln. of the corrosion preventing agent is preferably controlled to about 7-10pH.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the improvement of the rust-preventing surface of steel materials such as hot-rolled pickled steel sheets, cold-rolled steel sheets, and cast iron.

Generally, cold ivy steel plates and the like are subjected to surface treatment.

In other words, since it takes a considerable period of time for these various types of steel plates to be processed and used for their respective purposes after manufacture, they are not subjected to rust prevention treatment such as the application of rust prevention oil or water-soluble rust prevention agents. ing. However, all of these conventional rust prevention methods have the following drawbacks.

When anti-rust oil is applied, not only does the oil cause stickiness, but the biggest drawback is that a degreasing step is required when using Steel@0, and the degreasing solution must be disposed of as waste. Also,
If welding is carried out with rust preventive oil applied, the electrodes will become dirty, smoke will be produced significantly, and the work environment will be unfavorable. However, it should not be used for reasons such as the formation and toxicity of nitrosamines, which are carcinogenic substances, and for reasons such as having an adverse effect on the surfaces of chemical conversion treatments, plating, coating scissors, etc. It's starting to look like this.

Therefore, organic rust inhibitors have recently come into use. These organic rust inhibitors include saturated and unsaturated aliphatic carboxylic acids, namely formic acid, acetic acid, propionic acid, butyric acid, valeric acid, capunic acid, enanthic acid, capric acid, pelargonic acid, and capric acid. , undecylic acid, lauric acid, tridecylic acid, oristic acid, pentadecylic acid, palelectrotic acid, heptadecylic acid, stearic acid, acrylic acid, tacetonic acid, isocrotonic acid, undecylic acid, oleic acid, etc.), saturated and unsaturated fats. group dicarboxylic acids (i.e. Scheracic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, cepacic acid, maleic acid, fumaric acid, etc.), aromatic carboxylic acids (i.e. benzoic acid, Nidotetrabenzoic acid, ami)benzoic acid, toluic acid, aminetoluic acid, nitrotoluyl, phenylacetic acid, cinnamic acid, salicylic acid, etc.), aromatic dicarboxylic acids (phthalic acid, annophthalic acid, di)a7thalic acid, isophthalic acid , terephthalic acid), triazole*<
Pensito, Riazole, Methylbenzotriazole, etc.)
, imidazoles, alcohols (seven ethanolamines,
A small amount of surfactant (anionic surfactant, cationic surfactant, etc.), ionic surfactant,
Many use amphoteric surfactants in combination. In particular, since carboxylic acids have excellent rust prevention properties, most water-soluble corrosion inhibitors are based on carboxylic acids. However, steel plates treated with a corrosion inhibitor based on carboxylic acid may darken on the treated surface when dry or if stored for a long time, or the steel plate may be treated using a corrosion inhibitor as a tempering pressurizing liquid. After that, apply anti-rust oil,
If they are stored in stacks, oil stain problems occur.

As a result of extensive research, the present inventors have found a method to solve the drawbacks of organic corrosion inhibitors by using specific additives.

That is, when using the water-soluble organic corrosion inhibitor of the present invention, (a) a compound represented by the general formula (X represents a water atom, a hydroxyl group, an alkyl group, a carboxyl group, or a nitro group) or its alkyl metal; A method for removing corrosion from the surface of a steel material, which comprises adding at least one selected from salt, ammonium salt or amine salt, and (b) ethylenediaminetetraacetic acid or its alkali metal salt, ammonium salt or amine salt. .

A feature of the present invention is that when steel plates coated with only a water-soluble organic corrosion inhibitor are dried or stored stacked for a long period of time,
The entire treated surface darkens, but by adding a large amount of the additive of the present invention! Another feature of the present invention is that a water-soluble organic corrosion spinning agent is used as the temper rolling fluid, and after treating the steel plate, an anti-rust oil is applied. When stored in piles, oil stain occurs, but by adding the additive of the present invention, the problem of oil stain can be solved.

Another feature of the present invention is that by adding the additive of the present invention to a water-soluble organic corrosion inhibitor, the rust prevention performance is improved compared to 1. , subsequent chemical conversion treatment, plating, painting, etc.
This means that it will not have any negative impact on straw processing.

Examples of the water-soluble organic corrosion inhibitor used in the present invention include known ones, but preferably the saturated and unsaturated aliphatic carboxylic acids mentioned in the prior art section,
Examples include carboxylic acid-based corrosion inhibitors such as aliphatic dicarboxylic acids, aromatic carboxylic acids, and aromatic dicarboxylic acids.

Examples of the compound of general formula (1) used in the present invention include pyridine-2-carboxylic acid, pyridine-3-carboxylic acid, pyridine-4-carboxylic acid, and pyridine-5-carboxylic acid.
Methyl-3-carboxylic acid, pyridine-4-nitro-3-
Examples include carboxylic acid, pyridine-5-hydroxy-3-carboxylic acid, and pyridine-2,3-dicarboxylic acid. In addition, alkaline agents for making salts with these compounds include sodium hydroxide, potassium hydroxide, ammonia, heptanoethanolamine, monoisopropanolamine, triethanolamine, aminoethylethanolamine, n. -Hexyluan etc. are mentioned. The same alkaline agent as above can be used also when preparing a salt of ethylene dianetetraacetic acid.

In the present invention, at least one selected from a compound represented by the general formula (1) or a salt thereof and ethylenediane-tetraacetic acid or a salt thereof is added to the organic corrosion inhibitor, and aqueous ammonia, hydrazine, amines, (monoethanolamine, diethanolane, triethanolane,
It is preferable to adjust the pH to a range of 7 to 11 using monoisopropanolamine, hexylamine, etc.).

The organic corrosion inhibitor of the present invention may be used at a commonly known concentration. Further, the amount of the compound represented by the general formula (1) to be added is preferably about 0.01 to 5000 (the same applies to Juwashi-1 and below) in use concentration, and the amount of ethylenedianetetraacetic acid to be added is also about 0.01 to 5. A range of 5 cm is preferable.

When both are used together, the total amount is approximately 0.02 to 5%.
, with each component preferably being present in a concentration of about 0.01- or more.

Although the effect can be seen even if the concentration exceeds 5, it is not economical. As for how to add it, it can be added in advance to the water-soluble organic rust preventive, or it can be added separately at the time of use.

The present invention will be described below with reference to Examples.

Naochi indicates heavy i-.

Example 1 Caprylic acid 1-, pyridine-3-carboxylic acid 01%0*
1IIflK was made into an AT-M layer solution which was adjusted to pH 8 by adding ethanolamine as a neutralizing agent, and the steel plate was subjected to normal tempering and rolling, and a part of it was left in the form of a heavy roll on the roll exit side. Then some of them were coated with l#F oil and made into a coil.

Example 2 Isogoobanolamine was added as a neutralizing agent to an aqueous solution of benzoic acid 1 and pyridine-4-carboxylic acid 1, and the pH was adjusted.
Example using 9KII11 as the treatment liquid! A coil was obtained in a similar manner.

Comparative Example 1 Aqueous solution of caprylic acid was adjusted to pH 8 by adding Mineoethanoly as a neutralizing agent, and using 9J611 armpit,
A coil was obtained in the same manner as in Example 1.

Comparative Example 2 A coil was obtained in the same manner as in Example 2 except that pyridine-4-carboxylic acid was not used.

Example 3 To a 0.2* aqueous solution of aminobenzoic acid and ethylenecyanatetraacetic acid (hereinafter abbreviated as ID'l'm), ethanolamine was added as a neutralizing agent to adjust the pH to 10. Continuously spray the round pieces as a treatment liquid onto a surface-cleaned cold-rolled steel plate, immediately squeeze with a rubber roll), dry with a hair dryer, stack some of the front and back to that length, and apply rust preventive oil to some of the parts after drying. Stacked after application.

Example 4 4-nitrophthalic acid 11G, pyridine-8-*
Acid 0.31! , EDT mu-jl Na salt liD'l'
The same procedure as in Example 3 was carried out using a treatment solution which was adjusted to p:Ef9 by adding triethanol ζy as a neutralizing agent to a 0.2% aqueous solution in terms of aluminum.

Example 5 Tonitro 7-talic acid 0.51 Azelaic acid 0.5%.

The same procedure as in Example 3 was carried out, except that an aqueous solution of 0,05-pyridine-4-carboxylic acid was adjusted to pH 10.5 by adding seven ethanolamines, and the solution was adjusted to pH 10.5.

Example 6 0.1-N-alkyl-β-7ζnoprobionic acid was added as a surfactant to an aqueous solution of 2 gG of sebacic acid, 1,2,3-pesozotriazole α4-11D'f' The same procedure as in Example 3 was carried out except that the pH was adjusted to 9 using monoisopropanolamine as a neutralizing agent and 9mltt was used.

Comparative Example 3 1D'f' was not used, and Ogaki Gai was carried out in the same manner as in II Theory Example 3.

Comparative example 4 Virigi y-3-ttkMyWR11D'f'A-2Nm
The procedure was carried out in the same manner as in Example 4, except that Ogaki was not used.

Comparative Example 5 The same procedure as in Example 5 was carried out without using pyridine-4-carboxylic acid except for Ogaki. @ Comparative Example 6 11D'! The procedure was carried out in the same manner as in Example 6, except for using Ogaki.

When the fills in Examples and Comparative Examples were left for one month and after nine months of being subjected to the following wet box storage test.

Table 1 shows the performance evaluation regarding the occurrence of rust and oil stain. The wet box storage test was performed by tightening 10 specimens of 10XI (No.
The test was carried out in a wet box for 6 days with no oil applied and 30 days with oil applied.

Performance evaluation was carried out according to the following criteria.
There is a small amount of rust as well as oil stain.

×x: A large amount of rust was observed.

As is clear from the table, according to the method of the present invention, a water-soluble organic O corrosion inhibitor is used to eliminate the black discoloration of the treated surface, and the trenches are further coated with antimony oil. It is not a fool's errand to solve the problem of oil stain that occurs during treatment, but it is possible to further improve the rust prevention performance◎ 11 (more)

Claims (1)

[Claims] (1) When using water-soluble organic corrosion inhibitors,
(transformation) Compounds represented by the general formula (X represents a water atom, a hydroxyl group, an alkyl group, a carboxyl group, or a linear nitro group) or their alkali metal salts, ammonium salts, ammonium salts, and Φ) ethylenedianetetraacetic acid A method for improving the surface of a steel material, characterized by adding at least one selected from the group consisting of alkali metal salts, ammonium salts, and amine salts thereof.