JPS6246634B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an anticorrosive agent that prevents rust or corrosion on metal surfaces, and more particularly to an anticorrosive agent that exhibits excellent anticorrosive effects on iron and other metals. Iron or non-iron metal structures that are exposed to a wide range of corrosive environments such as air, water, and seawater, such as marine structures such as ship ballast tanks and floating docks, oil tanks, chemical equipment, and other structures and their auxiliary equipment. etc. are subject to severe corrosion. In order to prevent this corrosion, a method has been used in which a resin-curing anticorrosive agent is applied to the metal surface to form a film, thereby shielding the metal display from the corrosive environment. in this case,
When the metal surface is clean and not contaminated with rust, scale, or oil, the coating has good adhesion to the metal surface and the purpose of corrosion prevention is achieved, but if the metal surface is contaminated, When this occurs, the adhesion of the coating to the metal surface is significantly reduced, causing defects and causing local corrosion, making it impossible to obtain a sufficient anticorrosion effect. Therefore, when applying a resin-curing anticorrosive agent to a contaminated metal surface to form a film, the contaminants must be removed from the metal surface in advance, and rust removal, buffing, cleaning, etc. It is necessary to perform a pretreatment to clean the metal surface. However, this pretreatment has drawbacks such as requiring a great deal of labor and time. For these reasons, there is a demand for the development of an anticorrosive agent that does not require pretreatment or can be applied to contaminated metal surfaces with extremely simple treatment. It is preferable that a corrosive agent suitable for this purpose has the property of penetrating into the rust layer, scale layer, etc. on the metal surface and forming a strong and durable anti-corrosion coating on the base metal surface. In this connection, various non-drying oils are used as anticorrosive agents. For example, spindle oil, machine oil, cylinder oil,
Heavy oil, lanolin, wool grease, polyglycol oil, etc., alone or in combination, or these materials combined with amines, phosphorus compounds, petroleum sulfonates, fatty acid salts, fatty acid esters, etc. as effective additives. There is. However, in the case of the former, the permeability is not sufficient or
In the case of the latter, even if the permeability to the rust layer and scale layer is relatively good, a strong anticorrosion film is not formed on the base metal, so the anticorrosion effect is not sufficient, and a satisfactory anticorrosion effect has not yet been obtained. do not have. The present inventors have succeeded in forming a strong and durable anti-corrosion coating not only on clean metal surfaces but also on metal surfaces contaminated with rust, scale, oil, etc. As a result of intensive research to obtain anticorrosive agents with antirust or anticorrosive effects, we found that when using mineral oil as a base oil in combination with lanolin compounds such as lanolin and wool grease, and sulfosuccinate or its salts, conventional It has been found that the anticorrosive properties and the formation of a penetrating anticorrosive film are significantly superior to those of the anticorrosive agent. The present invention has been made based on this research fact. The anticorrosive agent of the present invention effectively contains (a) mineral oil, (b) at least one member selected from the group consisting of lanolin, lanolin fatty acids, lanolin alcohol, and wool grease, and (c) sulfosuccinate represented by the following general formula. It is an ingredient. general formula

[Formula] (In the formula, R represents hydrogen, an alkyl group or alkenyl group having 1 to 18 carbon atoms, and M represents hydrogen, an alkali metal, an alkaline earth metal, an amine, or an alkanolamine, respectively.) Mineral oil used in the present invention Spindle oil, turbine oil, machine oil, mobile oil, cylinder oil, heavy oil, etc. are suitable. When the anticorrosive agent is used at a high temperature (approximately 50°C or higher), it is preferable to use one with a relatively high viscosity, and at other temperatures, a wide range of viscosities can be used without any particular restrictions. Lanolin used in the present invention is an esterified product of lanolin fatty acid and lanolin alcohol, and wool grease is obtained by washing secretions adhering to wool. Typical sulfosuccinates represented by the above general formula used in the present invention include dioleyl sulfosuccinate, didodecyl sulfosuccinate, dioctyl sulfosuccinate, dibutyl sulfosuccinate, and the like. Particularly preferred are didodecyl sulfosuccinate and dioctyl sulfosuccinate. Examples of the salt include alkali metal, alkaline earth metal, amine or alkanolamine salts. The mixing ratio of (a) mineral oil, (b) at least one member selected from the group consisting of lanolin, lanolin fatty acids, lanolin alcohol, and wool grease and (c) sulfosuccinate represented by the above general formula can be varied over a wide range. It is effective. The preferred proportions are (a) component 30% by weight or more, (b) component 1 to 60% by weight, and (c) component 0.01 to 10% by weight.
More preferable proportions are component (a) 50% by weight or more, component (b) 3 to 50% by weight, and component (c) 0.1 to 5% by weight. The anticorrosive effect of the present invention can be further improved by mixing conventionally known corrosion inhibitors such as amines and imidazolines, or both. General formula for amines

A compound represented by the formula: (wherein R ₁ , R ₂ and R ₃ represent hydrogen, an alkyl group, an alkenyl group, a phenyl group, a cycloalkyl group, a hydroxyl group, a hydroxylalkyl group or an aminoalkyl group), Typical examples include octylamine, decylamine, dodecylamine, palmitylamine,
Examples include stearylamine, N·N-dimethylstearylamine, benzylamine, cyclohexylamine, and hydroxyethylamine.
In addition, as imidazoline, the general formula

[Formula] (In the formula, R ₁ is hydrogen, an alkyl group or an alkenyl group, R ₂ is an alkylene group,
represents hydrogen, a hydroxyl group, a hydroxyalkyl group, an amino group, or an aminoalkyl group, respectively), typical examples of which include 2-decyl imidazoline, 2-decyl imidazoline, and
Examples include oleyl imidaline, 2-decyl-1-hydroxyimidazoline, 2-decyl-1-hydroxyethylimidazoline, 2-decyl-1-aminoimidazoline, and 2-decyl-1-aminoethylimidazoline. The mixing ratio of amines or imidazolines is preferably 0.1 to 5% by weight. Hereinafter, the effects of the present invention will be clarified through Examples and Comparative Examples. The corrosion protection test was conducted according to the salt spray test method specified in JIS.Z2371. The test piece was a steel plate (JIS.
G3141, SPCC, 80 mm x 60 mm x 1.2 mm), and the anticorrosive agent was applied uniformly by spray. The amount of anticorrosion agent applied was 200±20g/m ² . This test piece was placed in a salt spray chamber, kept at a temperature of 35±2℃, and
% salt aqueous solution was sprayed onto the specimen in an amount of 3 ml/80 cm ³ ·hr. The test was conducted for 30 consecutive days. After the test, corrosion products were removed from the surface of the test piece, and the incidence of rust formed on the surface of the test piece was determined. The rust occurrence rate is defined as follows. Rust occurrence rate (%)=rust occurrence area on the surface of the test piece/surface area of the test piece ×100 The test results using the anticorrosive agent of the present invention are as follows.

【table】

【table】 The results of the comparative test are as follows.

[Table] Next, the corrosion rate was investigated by seawater immersion corrosion test. In the corrosion test, test pieces coated with an anticorrosive agent obtained in the same manner as in Examples 1 to 13 were immersed in seawater for 6 months. After the test, the corrosion products and anticorrosive agent were washed and removed from the surface of the test piece, and the corrosion rate (mm/year) was determined from the weight loss of the test piece. The test results and comparative test results using the anticorrosive agent of the present invention are as follows.

【table】

[Table] Examples 1 to 13, Comparative Examples 1 to 7, and Examples
As is clear from comparing and contrasting Comparative Examples 14 to 18 with Comparative Examples 8 to 13, the combination of the mineral oil of the present invention, at least one of lanolin, lanolin fatty acid, lanolin alcohol and wool grease, and sulfosuccinate These exhibit excellent synergistic effects in terms of corrosion protection. Next, using a test piece with rust already attached,
The formation of an anticorrosive film on the base metal surface was investigated by seawater immersion corrosion test. Corrosion tests were conducted using a steel plate whose surface was polished to #400 emery cloth (JIS.G3141, SPCC.80mm x 60mm x 1.2
Rust was generated on a test piece (mm) in an atmosphere with a relative humidity of 100% (rust adhesion amount: 21±4 g/m ² ), and an anticorrosive agent was applied thereto (application amount: 200±20 g/m ² ). This was carried out in the same manner as in Examples 14-18. After the exam,
Rust was removed from the surface of the test piece, and the state of formation of the anticorrosive film on the base metal surface was observed. The results are as follows.

【table】

[Table] As is clear from the above experimental results, the anticorrosive agent of the present invention exhibits an excellent anticorrosion effect. In addition, in the examples, examples using representative compounds are shown, but almost the same anticorrosive effect can be obtained even when other compounds are used.

Claims (1)

[Scope of Claims] 1. (a) Mineral oil, (b) at least one member selected from the group consisting of lanolin, lanolin fatty acids, lanolin alcohol, and wool grease, and (c) sulfosuccinate represented by the following general formula. Anticorrosive agent included as an ingredient. General formula [Formula] (In the formula, R represents hydrogen, an alkyl group or alkenyl group having 1 to 18 carbon atoms, and M represents hydrogen, an alkali metal, an alkaline earth metal, an amine or an alkanolamine, respectively.) 2 General formula [ An amine compound represented by the formula] (wherein R ₁ , R ₂ and R ₃ represent hydrogen, an alkyl group, an alkenyl group, a phenyl group, a cycloalkyl group, a hydroxyl group, a hydroxylalkyl group or an aminoalkyl group) and/or or _an imidazoline compound represented _by the general formula: The anticorrosive agent according to claim 1, which is obtained by mixing.