JPH0125826B2 - - Google Patents

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-rolled steel sheets and the like are subjected to surface treatment. In other words, since it takes a long time for these various types of steel plates to be processed and used for their respective purposes after they are manufactured, 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-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-preventing oil is applied, the electrodes will get dirty and smoke will be produced, making it unfavorable for the working environment. In addition, inorganic salts such as sodium nitrite and sodium borate have been used as water-soluble rust preventive agents; Due to reasons such as its negative impact on processing, it is no longer used. Therefore, organic rust inhibitors have recently come into use. These organic rust preventives are
Saturated and unsaturated aliphatic carboxylic acids (i.e. formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid,
capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, acrylic acid, crotonic acid, isocrotonic acid, undecylenic acid, oleic acid, etc.), saturated and unsaturated fats group dicarboxylic acids (i.e. oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, etc.), aromatic carboxylic acids (i.e. benzoic acid, nitro Benzoic acid, aminobenzoic acid, toluic acid, aminotoluic acid, nitrotoluic acid, phenyl acetic acid, cinnamic acid, etc.), aromatic dicarboxylic acids (phthalic acid, aminophthalic acid, nitrophthalic acid, isophthalic acid, terephthalic acid, etc.), triazoles (benzotriazole, etc.), imidazoles, amines (monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, aminoethylethanolamine, hexylamine, etc.) alone or in combination, with a small amount of surfactant (anionic). surfactant, cationic surfactant, nonionic surfactant,
Many use amphoteric surfactants in combination. In particular, carboxylic acids have excellent rust prevention properties, so
Most water-soluble organic corrosion inhibitors are based on carboxylic acids. However, steel plates treated with a corrosion inhibitor based on carboxylic acid,
When dried or stored for a long period of time, the treated surface may darken, or when a corrosion inhibitor is used as a temper rolling fluid to treat the steel plate, and the steel plate is coated with rust preventive oil and stored in stacks, the oil may become dark. There is a stain problem. The inventors of the present invention have conducted extensive research into a treatment method that has rust prevention properties and does not cause blackening of treated steel sheets or oil stains, etc. As a result, the inventors have discovered that the treatment method is based on a special combination of carboxylic acids. The present invention is based on a method that has not been previously used. That is, the present invention provides (a) one or more aliphatic dicarboxylic acids and (b) the general formula (X, Y, and Z represent a hydrogen atom, a hydroxyl group, an alkyl group, a carboxyl group, a nitro group, or an amino group) The present invention relates to a method for treating the surface of a steel material, characterized by: The feature of the present invention is that when steel plates treated with conventional water-soluble organic corrosion inhibitors, especially those based on carboxylic acids, are dried or stored stacked for a long period of time, the entire treated surface darkens. By using the product of the present invention, the treated surface can be kept clean. Another feature of the present invention is that a conventional water-soluble organic corrosion inhibitor, especially one based on carboxylic acids, is used as the temper rolling fluid, and after treating the steel plate, a rust preventive oil is applied. If stored in stacks,
Although oil stains occur, oil stains can be prevented by using the product of the present invention. Another feature of the present invention is that it maintains sufficient rust prevention performance. Another feature of the present invention is that the product of the present invention does not adversely affect subsequent surface treatments such as chemical conversion treatment, plating, and painting after treatment. Another feature of the present invention is that it has low toxicity and is extremely easy to handle. Examples of the aliphatic dicarboxylic acids used in the present invention include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, and fumaric acid. However, this is not limited to this. Examples of the compound of formula (1) include benzoic acid, toluic acid (o-, m-, p-), ethylbenzoic acid (o-, m-, p-), propylbenzoic acid (o-,
m-, p-), t-butylbenzoic acid (o-, m-,
p-), nitrosalicylic acid (o-, m-, p-),
Phthalic acid, isophthalic acid, terephthalic acid, aminobenzoic acid (o-, m-, p-), 2-amino-p
-Toluic acid, aminophthalic acid (3-,4-),
aminoterephthalic acid, 5-aminoisophthalic acid,
Nitrobenzoic acid (o-, m-, p-), dinitrobenzoic acid (2,4-,2,5-,3,4-,3,
5-,2,6-), 3-nitro-p-toluic acid,
Examples include, but are not limited to, 4-nitro-m-toluic acid, nitrophthalic acid (3-,4-,), 5-nitroisophthalic acid, nitroterephthalic acid, 3,6-dinitrophthalic acid, etc. . The method of using the present invention is to add ammonia water, ammonia water, Hydrazine, amines (monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, hexylamine, etc.)
It is preferable to adjust the pH to a range of 7 to 11 before use. In this case, the total amount of one or more aliphatic dicarboxylic acids contained in the solution is preferably in the range of about 0.01 to 10% (wt%, the same applies hereinafter), and furthermore, in general formula (1) Preferably, a total amount of one or a mixture of two or more of the indicated compounds is used in the range of about 0.01 to 10%. Considering the degree of improvement of the treated surface of steel, rust prevention, and economic efficiency, the range of about 0.1 to 2% is preferable for each. A surfactant can be further added, but in that case, the amount is preferably in the range of about 0.001 to 0.5%, and the type thereof is preferably a nonionic surfactant or an amphoteric surfactant. In addition, as a method of adding the rust preventive agent of the present invention, the aliphatic dicarboxylic acid and the compound represented by the general formula (1) may be prepared in advance and diluted with water before use, or they may be added separately at the time of use. A treatment liquid may be prepared by adding it to water. The method of the present invention will be explained below with reference to Examples. Note that % represents weight %. Example 1 Adipic acid 0.5%, 3,4-dinitrobenzoic acid
Using a 0.5% aqueous solution adjusted to pH 10 by adding monoethanolamine as a neutralizing agent, the steel plate is subjected to normal skin pass rolling, part of it is made into a coil shape on the exit side of the roll, and part of it is rolled. was coated with anti-corrosion oil and then made into a coil. Comparative Example 1 The same procedure as in Example 1 was carried out except that 3,4-dinitrobenzoic acid was not used and 1% adipic acid was used. Comparative Example 2 The same procedure as in Example 1 was conducted except that adipic acid was not used and 1% of 3,4-dinitrobenzoic acid was used. Example 2 A coil was obtained in the same manner as in Example 1 by adding isopropanolamine as a neutralizing agent to an aqueous solution of 1% sebacic acid and 1% 2-aminobenzoic acid and adjusting the pH to 9 as a treatment liquid. Ta. Comparative example 3 Sebacic acid 2 without using 2-aminobenzoic acid
The same procedure as in Example 2 was carried out except that % was used. Comparative Example 4 No sebacic acid, 2-aminobenzoic acid 2
The same procedure as in Example 2 was carried out except that % was used. Example 3 To an aqueous solution of 0.1% maleic acid and 0.7% 4-nitrophthalic acid, monoethanolamine was added as a neutralizing agent to adjust the pH to 10.5, and 0.03% polyoxyethylene alkyl ether, a nonionic activator, was added. The treated liquid was continuously sprayed onto a surface-cleaned cold-rolled steel plate, immediately squeezed with a rubber roll, and dried with a hair dryer. Some of them were piled up as they were, and some of them were coated with anti-rust oil after drying. After that, I piled it up. Comparative Example 5 Maleic acid without using 4-nitrophthalic acid
The same procedure as in Example 3 was carried out except that 0.8% was used. Comparative Example 6 4-nitrophthalic acid without maleic acid
The same procedure as in Example 3 was carried out except that 0.8% was used. Example 4 Azelaic acid 0.6%, aminoterephthalic acid 0.3%
To the aqueous solution, triethanolamine was added as a neutralizing agent to adjust the pH to 8, and 0.04% of Na salt of N-alkyl-β-aminopropionic acid was added as an amphoteric surfactant.The treatment solution was used to clean the surface. After spraying continuously on a cold rolled steel plate, immediately squeezing it with a rubber roll and drying it with a dryer, some of it was stacked as it was, and some of it was dried and then coated with anti-corrosion oil and then stacked. Comparative Example 7 Azelaic acid without aminoterephthalic acid
The same procedure as in Example 4 was carried out except that 0.9% was used. Comparative Example 8 No azelaic acid, aminoterephthalic acid
The same procedure as in Example 4 was carried out except that 0.9% was used. Example 5 The same procedure as in Example 3 was carried out except that 0.3% of succinic acid, 0.4% of phthalic acid, and 0.4% of o-nitrobenzoic acid were used. Comparative Example 9 The same procedure as in Example 5 was carried out except that 1.0% succinic acid was used without using phthalic acid or o-nitrobenzoic acid. Comparative Example 10 The same procedure as in Example 5 was carried out except that 0.5% of phthalic acid and 0.5% of o-nitrobenzoic acid were used without using corkic acid. Table 1 shows the performance evaluation regarding the occurrence of rust and oil stain in Examples and Comparative Examples. As is clear from the table, according to the method of the present invention, even with a water-soluble organic corrosion inhibitor based on carboxylic acid, the blackening of the treated surface peculiar to carboxylic acid can be eliminated, and the treated surface can be further coated with rust preventive oil. It can be seen that it not only solves the problem of oil stains that occur when treated with water, but also improves the rust prevention performance. In addition, in the wet box storage test in the table, 10 test pieces of 10 x 10 cm were tightened in a small vise, and then heated at 40℃ and 85%.
15 days for non-oiled RH wet box.
The oil-anointed items were tested by leaving them in for 30 days. Performance evaluation was performed based on the following criteria. ◎: No change ○: Slight black discoloration △: Discoloration and oil stain are observed ×: Discoloration and oil stain as well as a small amount of rust are observed XX: A large amount of rust is observed. 【table】

Claims (1)

[Scope of Claims] 1 (a) one or more aliphatic dicarboxylic acids and (b) general formula (X, Y, Z are hydrogen atoms, hydroxyl groups, alkyl groups, carboxyl groups, nitro groups, or amino groups) Treating steel materials with an aqueous solution or emulsion containing one or more of the compounds represented by A steel surface treatment method characterized by: