JPS5921955B2 - Rust prevention treatment method for steel materials - Google Patents

Description

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

Further, the present invention has an excellent rust prevention effect on treated steel materials when used as a cutting fluid for steel materials. Generally, the surface of cold-rolled steel sheets and the like is subjected to surface treatment to prevent corrosion and maintain aesthetic appearance.

In other words, since there is a long period of time after manufacturing these various steel plates before they are processed and used according to their respective uses, they are coated with anti-rust oil or chemically treated, or with volatile anti-rust paper. Anti-corrosion treatment such as packaging has been applied.

However, all of these conventional rust prevention methods have the following drawbacks. When anti-corrosion oil is applied, not only does the oil cause stickiness, but the biggest drawback is that a degreasing process is required when the steel plate is used, and the degreasing liquid must be disposed of as waste.

Furthermore, if welding is performed while the rust-preventive oil is applied, the electrodes will become dirty, smoke will be generated significantly, and the working environment will be unfavorable.

Already known water-soluble rust inhibitors, such as sodium nitrite, sodium borate, aromatic carboxylic acids, imidazoles, amines, and surfactants, are used alone or in combination, but they are mainly used in water or in the atmosphere. The rust prevention effect is poor in a humid atmosphere or when steel plates are in contact with each other in a hot and humid atmosphere, that is, when stacked in a JIS Z-0228 wet box.

There are also rust preventives that contain higher aliphatic amines, higher fatty acids, etc., but these have drawbacks such as poor drying properties and the need for a removal process similar to rust preventive oils. .
In addition, when using 3-hydroxy-γ-pyrone or 5-hydroxy-γ-pyrone as a single component, which is the main component of this rust inhibitor, water is dropped onto the steel plate to be treated. If steel plates are stacked and left in a high temperature and humid atmosphere, discoloration and stains may occur in some cases.

The present invention solves the problems of the conventional methods and makes it possible to exhibit an extremely good rust prevention effect without requiring any treatment in the next step.

That is, an aqueous solution of 3-hydroxy-r-pyrone or 5-hydroxy-γ-pyrone or a derivative thereof and nicotinic acid or an isonicotinic acid compound is adjusted to a neutral range using a neutralizing agent, and this is applied to the metal surface. It is characterized by the fact that it is applied to the surface to form a rust-preventing film. The effect of the present invention is not a rust-preventing effect under a specific environment, but rather in water, in the air, in an acid atmosphere, in a high-temperature and humid atmosphere where water droplets may exist while the steel plates to be treated are in contact with each other, or in a high-speed environment. It is effective against rust on metals under various conditions, such as during the temper rolling process when the temper rolling fluid is splashed onto the steel plate after rolling, or when the steam from the rolling fluid becomes water droplets and adheres to the steel plate. It is excellent.

This invention &'! Talent.

(wherein X and Y represent a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyal group, or a carboxyl group), 3-hydroxy-r-pyrone or 5-hydroxy-γ-
The main component is a pyrone compound, which is one type of nicotinic acid or isonicotinic acid compound represented by the general formula 8' (where X in formula () represents a hydrogen atom, a hydroxyl group, an alkyl group, or a carboxyl group). Alternatively, a mixed aqueous solution containing two or more types at the same time is neutralized with aqueous ammonia, hydrazine, or alkanolamines such as monoethanolamine and triethanolamine, and then processed into steel with an aqueous solution with a pH range of 7 to 10. use.

A water-soluble polymer compound or a surfactant can also be added thereto. Furthermore, the purpose can also be achieved by applying or adhering these mixed water solutions to an emulsion, that is, a water mixture of cutting oil, grinding oil, and rolling oil, to the surface of the steel material to form a rust-preventing film. can be reached. In this case, the concentration of 3-hydroxy-γ-pyrone or 5-hydroxy-γ-pyrone of the above general formula and its derivatives contained in the solution is in the range of 0.01 to 10% (the same applies below weight I%). , and the nicotinic acid or isonicotinic acid compound added to this is used in the range of 0.01 to 5 (F6), but from the viewpoint of rust prevention and economical efficiency, the main component 3-hydroxy-γ-pyrone or 5-hydroxy The -γ-pyrone compound and the additive nicotinic acid or isonicotinic acid compound are both particularly preferably in the range of 0.1 to 2%.If a surfactant is further added, the range is 0.01 to 0.5%. In addition, when a polymer compound is added, it is preferably in the range of 0.01 to 2.% from the viewpoint of corrosion resistance or uniformity of the treated film, which contributes to improving the rust prevention property.The treated steel material according to the present invention One of the features is that the surface can be directly painted or plated, and the same performance as that obtained by painting or plating an untreated metal surface can be obtained.The following describes the implementation of the present invention. Give an example.

Example 1 A treatment liquid was prepared by adding monoethanolamine as a neutralizing agent to an aqueous solution of 0.4% 2-hydroxymethylpyromeconic acid and 0.3% nicotinic acid to adjust the pH to 8.5,
Normal temper rolling was performed, and water was intentionally applied to a portion of the steel sheet on the exit side of the rolls to form a coil.

Example 2 A solution of 0.3% 2-hydroxymethylpyromeconic acid and 0.3% isonicotinic acid in water was adjusted to pH 8.5 by adding aminoethylethanolamine as a neutralizing agent and used as a treatment liquid. It is continuously sprayed onto a surface-cleaned cold-rolled steel plate and immediately dried with a rubber roll and a v-dryer.

Example 3 An aqueous solution containing 0.5% of 2-methyl-3-hydroxy-γ-pyrone and 0.3% of nicotinic acid amide was added with monoethanolamine as a neutralizing agent to adjust the pH to 8llC as the treatment solution. Continuously spray on a surface-cleaned cold-rolled steel plate and immediately dry with a rubber roll and a squeeze dryer.

Example 4 Monomer was added as a neutralizing agent to an aqueous solution of 0.35% 2-hydroxymethylpyromeconic acid, 0.2% isonicotinic acid, and 0.05% nonionic surfactant (polyoxyethylene alkyl ether). A treatment solution adjusted to pH 9 by adding ethanolamine is continuously sprayed onto a cold-rolled steel sheet whose surface has been cleaned and immediately dried using a rubber roll and a v-dryer.

Example 5 Mineral oil emulsion water mixture with 0.4% 2-hydroxymethylpyromeconic acid and 0.2% isonicotinic acid.
An aqueous solution prepared by adding 0.05% of a nonionic surfactant and 0.1% of an acrylic acid resin, which is a water-soluble polymeric compound, to an aqueous solution adjusted to PHLO with triethanolamine is used as a cutting fluid for steel materials. .

Tables 1 and 2 show the rust resistance test results of the steel sheets treated by the method of the present invention and comparative examples, and Table 3 shows the results of direct paintability. In Table 3, *l: Paint...acrylic and epoxyurea *2
: Sodium nitrite (1): Cross cut Erichsen 7 scale, square grid evaluation method: The coating film was peeled off with cellophane tape and evaluated based on the degree of peeling.

(2): Immediately after immersing the next adhesion test sample in deionized water at 40°C for 24 hours. The adhesion of the coating was tested.

The test items are the same as the primary adhesion test.

Evaluation: 10 (excellent) to 0 (unsatisfactory) As described above, the method of the present invention not only sufficiently exhibits the rust prevention effect in various soil environment atmospheres, but also makes it possible to remove the rust preventive agent before the next process. Since painting and other necessary treatments can be performed immediately without any need, work efficiency can be improved.

Claims (1)

[Claims] 1 General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, X and Y are hydrogen atoms, hydroxyl groups,
Indicates an alkyl group, a hydroxyalkyl group, and a carboxyl group. ), 3-hydroxy-γ-pyrone or 5
The main component is a -hydroxy-γ-pyrone compound, which has the general formula (II) ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (In formula (II), X represents a hydrogen atom, a hydroxyl group, an alkyl group, or a carboxyl group. 1. A method for rust-preventing steel materials, which comprises adding one or more of nicotinic acid or isonicotinic acid compounds shown in ) and treating with an aqueous solution or emulsion solution having a pH in the range of 7 to 10.