JPH10310722A - Rust preventing agent and rust prevention using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rust preventing agent simple in a rust preventing process, thin in thickness of coated film after coating, capable of surely preventing the occurrence of rust on an iron base, by using an aqueous solution containing silicon ion. SOLUTION: This rust preventing agent uses an aqueous solution containing preferably >=1 % silicon ion concentration [e.g. a potassium silicate (e.g. potassium metasilicate) or sodium silicate (e.g. sodium metasilicate). The rust preventing agent is used, for example, by a method for coating an iron base with the rust preventing agent by spray, etc., raising the coated surface temperature to 170 deg.C by a burner, etc., and maintaining the temperature for one or more minutes. By the method, the silicate in the aqueous solution is uniformly stuck to the surface of the iron silicate, a dried coated film is formed and the iron base can be prevented from coming into contact with oxygen in air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rust preventive and a rust preventive method using the same, and more particularly, to a rust preventive capable of exhibiting a rust preventive effect in a relatively simple working process. It relates to a rust prevention method using the same.

[0002]

2. Description of the Related Art Rust is formed by agglomeration of fine crystals such as hydrated oxides and basic hydroxides of metals. In particular, rust generated on iron base materials generally has poor self-protection and is left untreated. Then, deterioration of the material due to rust on the surface proceeds. The chemical reaction of rusting most requires water and oxygen, and the free energy change of the chemical reaction between metal and oxygen is negative at room temperature, so oxidation is a naturally occurring reaction. For this reason, metal substrates such as iron are usually subjected to rust prevention treatment by various methods. Some of the conventional rust prevention methods are described below.

[0003] As one of rust prevention methods, there is a method in which an oily substance is first applied to an iron base to prevent the bond between iron and oxygen. However, in this method, the oily substance applied to the iron base material may be oxidized and deteriorated, and the oily substance after application may be transferred to the other object by contact with another object. There is also.
On the other hand, a method of applying a suitable viscosity to the oily substance and applying a paint or the like which can be hardly transferred by drying to an iron base has been proposed. However, if a gap is formed, rust is generated from the gap and proceeds.

Therefore, at present, a method of plating zinc, tin, or the like by, for example, a hot-dip plating method is often adopted. If zinc or tin is plated, zinc and tin are oxidized before the iron base, so that it is possible to prevent oxygen from reaching the iron base. In particular, tin is considered to be less harmful to the body, and is therefore used for plating on the inside of cans and the like. However, in this method, it is necessary to perform plating treatment by melting zinc or tin, so that the working process is complicated, and there is a problem that an additional process is required to dispose the molten material in a safe state. . In addition, in both the method using paint and the method using plating, it is sometimes necessary to form fine irregularities on the surface of the iron base using a sandpaper or a grinder or the like in order to enhance the adhesion between the iron base and the paint or plating metal. It takes a lot of time and effort.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a simple rust preventive treatment step, a thin film thickness after coating, and reliable formation of rust on an iron substrate. It is an object of the present invention to provide a rust preventive agent capable of preventing rust and a rust preventive method using the same.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that an aqueous solution containing silicon ions, particularly an aqueous solution of potassium silicate or sodium silicate, is applied to an iron substrate. It has been found that rust can be prevented from being generated on the iron base material, and the present invention has been completed.

That is, the rust preventive according to the present invention is characterized by comprising an aqueous solution containing silicon ions, and in particular, comprises an aqueous silicate solution comprising at least one of potassium silicate and sodium silicate. It is characterized by.

Further, in the rust prevention method according to the present invention, such a rust preventive is applied to an iron base material, the applied surface temperature is set to 70 ° C. or higher, and the state is maintained for 1 minute or more, and the rust prevention agent is applied to the iron base. It is characterized by forming a film of an acid salt. Also,
The temperature is increased in advance so that the iron base temperature becomes 70 ° C. or higher, and the rust preventive is applied to the iron base, and the applied surface temperature is reduced to 70 ° C.
The silicate film may be formed on the iron base by holding the temperature of not less than 0 ° C. for 1 minute or more. As a method of applying the rust preventive to the iron base, any of spraying, painting, and dipping may be used. Furthermore, if the method of immersing the iron base material in the boiled rust preventive agent and maintaining the iron base surface temperature at 70 ° C. or higher for 1 minute or more is adopted, the flow operation by a belt conveyor or the like can be performed, and the iron base surface can be obtained. In this case, the operation of forming a film of the silicate can be made extremely easy.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a rust preventive agent and a rust preventive method according to the present invention will be described. The rust preventive according to the embodiment comprises an aqueous solution containing silicon ions, particularly an aqueous silicate solution comprising at least one of potassium silicate and sodium silicate. Examples of potassium silicate include potassium metasilicate (K ₂ SiO ₃ ) and potassium hydrogen disilicate (KHSi ₂ O ₅ or K ₂ Si ₄ O _9).
.H ₂ O) and the like, and as the sodium silicate,
Sodium metasilicate (Na ₂ SiO ₃ ) and its various hydrates, sodium orthosilicate (Na ₄ Si)
O ₄ ), sodium disilicate (Na ₂ Si ₂ O ₅ ), sodium tetrasilicate (Na ₂ Si ₄ O ₉ ), and the like. Good. This water glass is generally mK ₂ O · nSiO
₂ or mNa ₂ O · nSiO ₂ , where m is 1 and n is in the range of 0.5 to 4, which is easily available industrially,
Those having n = 2 to 4 are preferable because they are inexpensive. Since these potassium silicate or sodium silicate crystals are soluble in water, it is easy to prepare an aqueous solution having a concentration of 1% or more.

Here, the concentration of the silicate in the aqueous solution is preferably 1% or more. Even if the concentration in the aqueous solution is lower than 1%, a certain degree of rust-preventing effect can be obtained, but in order to form a silicate film capable of exhibiting a sufficient rust-preventing effect, it is necessary to apply In addition, it is necessary to repeatedly perform drying and to laminate a film of silicate, so that the working time becomes longer. A concentration of about 1% of the silicate in the aqueous solution is sufficient, and the cost increases as the concentration increases. Therefore,
It is preferable to determine the concentration in the aqueous solution in consideration of these.

In order to prevent rust on the surface of an iron substrate using such a rust preventive, the following steps are taken, for example. First, a rust inhibitor, which is an aqueous solution of a silicate composed of at least one of potassium silicate and sodium silicate, is applied to the iron base. This coating method may be spraying, brushing or the like, or dipping by dipping in an aqueous solution and pulling up. At this time, the temperature of the aqueous solution is not particularly limited, but thereafter, the temperature of the application surface is set to 70 ° C. or higher by using a heating device such as a burner, and the temperature is maintained for 1 minute or more. By doing so, the silicate composed of the potassium silicate component or the sodium silicate component in the aqueous solution uniformly adheres to the surface of the iron substrate, and a dried film is formed. Therefore, it is possible to prevent oxygen in the air from coming into contact with the iron base, and iron ions released from the iron base due to the presence of water are combined with oxygen in the air to form iron oxide, and rust is generated on the iron base. The phenomenon can be prevented from occurring.

In addition, instead of bathing the iron base material in advance,
The above-described effects can be obtained even when the rust preventive agent according to the present invention is used as a substitute for a commonly used cutting oil during a normal cutting operation. In this case, utilizing the fact that the surface temperature of the iron base material inevitably increases due to the cutting work, the amount of the rust preventive agent sprayed is adjusted so that the surface temperature does not fall below 70 ° C even when the rust preventive agent is sprayed. By maintaining the controlled state for 1 minute or more, the application of the rust preventive can be completed without adding any special operation process. Alternatively, the iron base may be immersed in the boiled rust preventive, and the surface of the iron base may be maintained at a temperature of 70 ° C. or higher for 1 minute or more to apply the rust preventive. Since it is not necessary to use a simple device, rust prevention work can be performed more easily. In order to prevent rust on the surface of the iron substrate, it is preferable that no oil film exists on the surface of the iron substrate regardless of which method is used, and after performing degreasing treatment with dilute hydrochloric acid or the like, the rust prevention treatment using the rust inhibitor described above is performed. Good to do.

According to the rust prevention method according to the present invention, as in the case of the conventional paint coating and plating treatment, the iron base such as sanding, which has been used to strengthen the bond between the iron base and the paint or plated metal. There is no need to perform surface unevenness treatment, and the film formed by the rust preventive can be made much thinner than in the case of paint coating or plating. This is an excellent method.

[0014] In addition, the film formed by the conventional paint coating or plating treatment often cracks gradually with the passage of time, and rust is often generated from the cracked portion. The salt coating is less likely to crack over time. Further, when paint or the like is applied on the silicate film, even if cracks or pinholes occur in the paint film or the like, rust can be prevented from progressing therefrom.

[0015]

Next, the present invention will be described in detail with reference to more specific examples. In the examples, a rust preventive was produced by the following method. First, mK ₂ O.
Using a commercially available aqueous solution labeled nSiO ₂ (m: n = 1: 3.4), an aqueous silicate solution having a concentration of about 1% was prepared.
A rust preventive according to the present invention was produced. Here, the prepared iron plate surface having a thickness of about 0.1 mm to be rust-proofed is polished with a cutting machine such as a grinder while spraying the rust-preventive agent instead of the cutting oil. Although the surface temperature of the iron base increases during polishing, the surface temperature of the iron base is maintained at about 70 to 90 ° C. for about 1 to 5 minutes while controlling the amount of the rust preventive sprayed. As a result, a rust inhibitor is applied to the surface of the iron base, and the dried surface of the iron base is covered with silicate crystals.

The iron base thus subjected to the rust-prevention treatment is referred to as a first embodiment, and the iron base obtained by scratching the iron base with a nail or the like is referred to as a second embodiment. As Comparative Example 1, 1 at room temperature of about 18 to 25 ° C.
After being left for a year, it was observed whether or not rust occurred on the iron substrate.

As a result, no rust was observed on the iron substrate in each of Example 1 and Example 2, and no rust was observed on the scratched portion in Example 2. . On the other hand, the iron substrate according to Comparative Example 1 was covered with red rust and corroded to the extent that it easily collapsed by human power.

Next, as Example 3, an iron plate whose surface was covered with red rust was immersed in the boiling rust preventive agent, and the state where the iron plate surface temperature was 70 ° C. or higher was maintained for 1 minute or more. As a result of forming a film of silicate on the iron plate surface, no further progress of rust was observed.

As is clear from the above results, the use of the rust preventive agent according to the embodiment can reliably prevent the generation of rust. In addition, the thickness of the film after the application of the rust preventive agent is much thinner than that of the case of paint or plating, and seems to be particularly suitable for the rust preventive effect on precision parts.

[0020]

As described above, the rust preventive according to the first aspect of the present invention comprises an aqueous solution containing silicon ions. In particular, the rust preventive according to the second aspect comprises potassium silicate or sodium silicate. Since it is composed of at least one kind of silicate aqueous solution, if it is applied to an iron substrate and dried, a film of silicate is formed on the surface of the iron substrate.
To prevent contact with oxygen and oxygen, of course,
It is possible to prevent generation of rust without binding of iron ions and oxygen. In this case, even if the concentration of the aqueous solution is as low as about 1%, a sufficient effect can be obtained, the cost is low, and the thickness of the film formed on the iron substrate is very small. It is particularly suitable as a rust preventive treatment for parts and the like that require precision.

According to a third aspect of the present invention, there is provided a rust preventive method, wherein the rust preventive agent according to the first or second aspect is applied to an iron substrate, and then the coated surface temperature is 70 ° C. or more for 1 minute or more. Since the film of the silicate is formed on the iron substrate while being held, it is not necessary to melt the plating metal to produce a coating liquid unlike the conventional paint coating and plating processes. Further, there is no need for a conventional work process such as forming irregularities on the surface of the iron base material in advance using sandpaper or the like in order to promote the adhesion of paint or plating metal, so that the treatment process can be significantly simplified. In addition, the rust preventive agent according to claim 1 or 2 is applied to the iron base material after the temperature is raised in advance so that the iron base temperature becomes 70 ° C. or higher as in the rust prevention method according to claim 4. However, a method of forming a film of the silicate on the iron base by holding the coating surface temperature at 70 ° C. or more for 1 minute or more is also conceivable, and a method can be appropriately selected depending on the application. As a method of applying the rust inhibitor to the iron base material, any method of spraying, painting, and dipping may be used, and it can be appropriately selected according to the use.

Further, as in the rust preventive method according to claim 6, the iron base may be immersed in the boiled rust preventive, and the iron base may be kept at a surface temperature of 70 ° C. or more for 1 minute or more. ,
In this case, since a special operation is not required and a flow operation using a belt conveyor or the like is possible, it is possible to more easily perform the film formation using the silicate.

Claims (6)

[Claims] 1. A rust preventive comprising an aqueous solution containing silicon ions. 2. The rust inhibitor according to claim 1, comprising an aqueous silicate solution comprising at least one of potassium silicate and sodium silicate. 3. After applying the rust inhibitor according to claim 1 or 2 to an iron substrate, the surface temperature of the application is set to 70 ° C. or higher,
The rust prevention method for an iron substrate, wherein the state is maintained for 1 minute or more to form a film of the silicate on the iron substrate. 4. After raising the temperature so that the iron base temperature becomes 70 ° C. or higher, the rust preventive agent according to claim 1 or 2 is applied to the iron base, and the coating surface temperature is raised to 70 ° C. or higher. The rust prevention method for an iron substrate, wherein the silicate film is formed on the iron substrate by holding the iron substrate for at least one minute. 5. The rust-preventing method according to claim 3, wherein the rust-preventive agent is applied to the iron base by any of spraying, painting and dipping. 6. An iron substrate is immersed in the rust preventive agent according to claim 1 or 2, and the surface temperature of the iron substrate is kept at 70 ° C. or more for 1 minute or more, and The rust-prevention method for the iron base material, wherein the silicate film is formed.