JP2020041213A - Rust preventive sheet and rust preventive method - Google Patents

Abstract

To provide means suppressing generation of rust, and reducing load of operations for removing rust before product shipment or before product utilization when an iron product is not stored or used at a factory, a site or the like in a short time.SOLUTION: A rust preventive sheet to which a zinc powder is fastened and which has flexibility or plasticity covers an iron product at a state that at least a part of the sheet is in contact. Since zinc having sacrificial protection effect contacts with iron partially, generation of iron rust is prevented electrochemically, and rust prevention of the iron product in short time is available. The rust preventive sheet may have water absorption and may not have it.SELECTED DRAWING: Figure 7

Description

  The present invention provides a rust preventive sheet and rust preventive that suppresses the generation of rust when iron products are stored or not operated for a short period of time at a factory or site, and reduces the load of rust removal work before product shipment or product operation. About the method.

  Iron dies and small metalwork parts are not used on holidays but are stored at factories or the like, and may be used after the holidays. In this case, depending on the environment of the storage place, iron rust may be generated due to oxygen, moisture, corrosive substances and the like in the air, and this may cause a defect in a product manufactured by a mold or the like.

  Immediately before using a mold or the like, there is a need to remove iron rust by mechanical removal (sanding, etc.) or chemical removal in order to eliminate iron rust. Was causing the up. Even in large plants such as power plants and chemical plants, many iron products are used and are often stored in factories before product shipment. Was sought.

  Against this background, techniques for preventing the occurrence of iron rust, such as a volatile rust preventive, have already been established. According to the Japanese Industrial Standards shown in Non-Patent Document 1, rust preventive oil, rust preventive agent, rust preventive paper, rust preventive film, peelable plastic, desiccant, deoxidizer, inhibitor, chelate compound are used as rust preventive packaging methods. It is described and also contains a vaporizing rust inhibitor. Non-Patent Document 2 also describes the characteristics of these rust preventives. Non-Patent Documents 3 and 4 disclose anti-rust paper and anti-rust film.

  As a method for preventing rust of iron, there is an electrochemical method called sacrificial corrosion protection, in addition to the chemical method such as the above-described vaporizable rust inhibitor. BACKGROUND ART Sacrificial corrosion protection is known as a technique for suppressing the generation of rust on iron by contacting a metal that is more easily rusted than iron. A typical example is zinc contained in galvanized iron. Patent Literature 1 describes a basic composition of an anticorrosion material containing zinc powder having a large sacrificial anticorrosion effect, and defines the particle diameter of the zinc powder.

JP-A-10-96092

Japanese Industrial Standards, JIS Z0303, "Rust prevention packaging method general rules (2009)" Features of vaporizable rust preventive film and its rust prevention guide | Juntsunet 21, https://www.juntsu.co.jp/rust/rust_kaisetsu03.php ThreeBond Technical News, issued July 1, 1987, "Volatile rust preventive (VCI)" ITOCHU Plastics Co., Ltd., Cortec “Corrosion prevention packaging and system rust prevention casebook” http://www.itc-ps.co.jp/cortec/pdf/case.pdf

  However, both the methods of Non-Patent Document 1 and Non-Patent Document 2 have the following disadvantages. Although rust preventive oil has an effect of blocking oxygen and moisture in the atmosphere, oil removal work may be required in use, and storage for a short period of time causes a cost increase.

  The anticorrosive paper and anticorrosive film described in Non-patent Document 3 and Non-patent Document 4 use a vaporizable rust preventive agent, so there is concern about the environment, and they are completely sealed to maintain the effect. It is necessary and may not be applicable depending on the product shape. Plastics also require direct coating of the product and are not applicable depending on the product shape. Desiccants and oxygen scavengers, like vaporized rust inhibitors, need to seal the product, and some products cannot be applied. Inhibitors are adsorbed on the surface of iron products to form a hydrophobic film, so if they remain, they may adversely affect product performance.Similar to chelate compounds, special complex salts are formed, which may affect products. Could not be ignored.

  The method described in Patent Literature 1 is to disperse zinc powder in a synthetic resin and attach it to a metal surface. Patent Document 1 discloses a particle size range that reduces the contact resistance between the metal surface and the zinc powder. However, it is premised that the zinc powder is in contact, and depending on the product form such as a product having a complicated shape. On the other hand, a portion that is not in contact with zinc powder has a high possibility of rusting and cannot be applied.

  Therefore, on the premise of storage for a short period of time of several days to several weeks, post-treatment is not required, safe, labor-saving, and rust prevention technology that can be installed more easily is required at production sites. This is an important issue for reducing production costs.

  An object of the present invention is to provide a rust preventive sheet and a rust preventive method that can be applied safely and without any hassle for short-term storage of iron products.

  The present invention is a rust preventive sheet for preventing or suppressing the generation of rust on an iron product, wherein the zinc powder is fixed and has flexibility or flexibility.

  The present invention is a rust prevention method characterized in that the rust prevention sheet is covered with at least a part of the iron product in contact with the iron product to prevent or suppress the generation of rust on the iron product.

  As described above, iron products react with oxygen, moisture, and the like in the air to generate iron rust. The present invention is a zinc alloy having a sacrificial anticorrosive action, which is partially in contact with iron, thereby electrochemically suppressing the generation of iron rust, and suppressing the adhesion of moisture and corrosive substances to iron products. Rust prevention for a short period of time.

It is a comparative example of the present invention, and is a result of observing the surface of a test piece after completely covering the flat test piece with a net to which no rust-preventive paint is applied and allowing the test piece to stand for one week. Fig. 3 is an example of the present invention, showing the results of observation of the surface of a test piece after completely covering the flat test piece with a rust preventive sheet and leaving it to stand for one week. It is a comparative example of the present invention, and is a result of observing the surface of the test body after completely covering the triangular prism-shaped test body with a net to which no rust-preventive paint is applied and allowing the test body to stand for 2 weeks. Fig. 3 is an example of the present invention, showing the observation results of the surface of the test body after completely covering the triangular prism-shaped test body with a rust-preventive sheet and allowing it to stand for 2 weeks. It is an Example of this invention and is a figure which shows the procedure of a test which confirms the effect of a rust prevention sheet using ferrite stainless steel (SUS430) and an iron nail (also nail). 5 is an observation result 5 hours after an exposure test in a test for confirming the effect of the rust preventive sheet of FIG. 5. 7 is an observation result 72 hours after an exposure test in a test for confirming the effect of the rust preventive sheet of FIG. 5.

  The rust preventive sheet of the present invention is characterized in that zinc powder is fixed and has flexibility or flexibility.

  A flexible or flexible sheet-shaped member can be used as the base material (sheet body) of the rustproof sheet. The substrate is not particularly limited, and a film having flexibility or flexibility having voids, a sheet, a net, a mesh-like member, a nonwoven fabric, or the like can be used. Even a non-porous material can be used as a substrate as long as it has flexibility or flexibility. As the sheet, a woven or nonwoven fabric made of natural or synthetic fibers, paper, or a plastic sheet made of polyethylene or polypropylene is used.

  The material of the base material is not particularly limited, and plastic, cotton, rubber, and other composite materials can be used. A metal net or the like can also be used, but in this case, it is necessary to use a metal that is more noble than iron, such as copper or nickel.

  The appearance, size, and thickness of the substrate are not particularly limited, and may be appropriately selected depending on the application. The method of using the rust prevention sheet will be described later, but for large iron products, it is not necessary to cover a large iron product with one rust prevention sheet because multiple rust prevention sheets can be used. . The thickness should be thin as long as it is strong enough not to be easily damaged in normal use. By making it thin, it is easy to secure flexibility or flexibility, and it is light and easy to handle.

  The rust preventive sheet of the present invention may have water absorbency or may not have water absorbency. The zinc powder may be fixed on one or both surfaces of the rust preventive sheet, but it is effective to fix the zinc powder on the surface in contact with the iron product in order to effectively exhibit the sacrificial anticorrosion effect. .

  The zinc powder is fixed via a binder so as not to be easily separated from the substrate. A zinc powder having a particle size of 3 to 10 μm can be used. As the zinc powder, an organic zinc paint using a natural or synthetic resin as a binder, an inorganic zinc paint using sodium silicate as a binder, and other deposition methods are also used. Met.

  The type of the binder is not particularly limited as long as the binder does not inhibit the sacrificial corrosion protection of the zinc powder having the sacrificial corrosion protection. On the other hand, it is necessary that the binder does not easily separate from the base material and that the binder itself does not adhere to the iron product during use. Further, the rust prevention sheet needs to have flexibility or flexibility even after the zinc powder is fixed to the base material.

  As the binder, it is possible to use a coating material which is applied to a substrate and dried to be cured as shown in Examples described later. The paint is liquid before drying and easily disperses the zinc powder, and is also preferable from this point. The content ratio of the zinc powder to the paint can be 25 to 75% by weight.

  An example of the production procedure of the rustproof sheet of the present invention is shown below. The following manufacturing procedure is an example of the manufacturing procedure of the rustproof sheet of the present invention, and the manufacturing procedure of the rustproof sheet of the present invention is not limited thereto.

  The rust preventive sheet of the present invention is obtained by applying a coating material in which zinc powder is dispersed to a flexible or flexible net, which is a base material, and drying the coating. At this time, if the amount of the paint applied is too large, the flexibility or flexibility of the rust preventive sheet is impaired, so care must be taken. Drying is performed until the paint does not adhere to other objects.

  The method of using the rust preventive sheet of the present invention will be described. The iron product is covered with a rust prevention sheet so that at least a part of the iron product comes into contact with the iron product. You may cover an iron product with a rust prevention sheet so that the whole iron product may contact a rust prevention sheet. As a result, zinc, which has a sacrificial anticorrosive action, partially contacts iron, thereby electrochemically suppressing the generation of iron rust. Further, the rust preventive sheet appropriately absorbs moisture and corrosive substances in the air, and exhibits a physicochemical effect of suppressing rust generation of iron products. These actions enable short-term rust prevention of iron products.

  Hereinafter, the present invention will be specifically described with reference to Examples.

<Example 1>
The target iron product specimen is a rolled steel material for general structural use (SS400), and has two shapes, a flat plate and a triangular prism. The shape of the triangular prism assumes that it is difficult to completely cover the actual product. The flat specimen has a length of 150 mm, a width of 100 mm, and a thickness of 1 mm. The test piece having a triangular prism shape is obtained by bonding the above-mentioned flat test piece with tape so as to form a triangular prism. Each test body was degreased and washed with acetone before the test, washed with water, and then completely dried with a drier.

  The material covering this specimen is a polyester furoshiki net having a fiber diameter of about 130 μm and a void of about 500 μm. A rust preventive paint containing zinc powder and butyl rubber was spray-applied to the net, and the contained isopropyl alcohol was evaporated at room temperature for one day and dried to obtain a rust preventive sheet. As a result of observation with a stereomicroscope, the component containing zinc powder was fixed around the fibers of the net, and did not narrow the voids in the net.

  FIGS. 1 and 2 show a case where a flat test piece is completely covered with a net to which no rust preventive paint is applied (Comparative Example) and a case where it is completely covered with a rust preventive sheet (Example). It is a figure showing the surface condition of a specimen. The standing atmosphere is a state in which the temperature is 25 ° C. and the humidity is 75%, and the state after one week is compared.

  As shown in FIG. 1, when covered with a net to which no rust-preventive paint is applied, red rust occurs around the periphery. On the other hand, when covered with a rust preventive sheet, no red rust was generated as shown in FIG.

  FIGS. 3 and 4 show the results obtained when the test piece having a triangular prism shape was lightly covered with a net to which no rust preventive paint was applied, and when the test piece was lightly covered with a rust preventive sheet. In FIGS. 3 and 4, the upper and lower ends of the test piece are adhesive tapes. The leaving atmosphere is the same as that of the above-mentioned flat specimen, and the leaving period is 2 weeks.

  As shown in FIG. 3, when the coating was lightly covered with a net to which no rust preventive paint was applied, generation of red rust was often observed. In an atmosphere where the humidity during the rainy season was close to 90%, red rust occurred in one day. On the other hand, when lightly coated with a rust-preventive sheet, as shown in FIG. 4, no red rust was generated and the rust-preventive effect was remarkably recognized. In addition, it was found that even in the atmosphere during the rainy season, although not as much as in FIG. 2, the generation of red rust can be considerably suppressed.

<Example 2>
FIG. 5 is a diagram showing a test procedure for confirming the effect of the rust preventive sheet using ferrite stainless steel (SUS430) and iron nails (also nails). Ferritic stainless steel (SUS430) and iron nails (mat nails) were allowed to stand in a closed container filled with an acidic vapor containing hydrochloric acid, exposed, and the rusting phenomenon was accelerated to observe the condition. The upper part is an overall view of the evaluation sample, and the lower part is a state in which the left half is covered with a rust preventive sheet manufactured in the same manner as in Example 1.

  As shown in FIG. 5, the left half of the sample was covered with the rust preventive sheet of the present invention, and the right half was directly exposed to the acidic vapor as it was in order to clearly understand the effect of the cloth (rust preventive sheet) coated with the rust preventive paint. And observed over time. The results are shown in FIGS. 6 and 7.

  FIG. 6 shows a state 5 hours after the start of the exposure test. The left half covered with the rust preventive sheet of the present invention has no rust at all, while the right half has been eroded by acidic vapor and rust has already been generated. FIG. 7 shows a state where the exposure test is further continued and 72 hours have elapsed. Even at this point, it can be seen that while the left half is completely rust-prevented, the right half is eroded by acidic vapor and severe rust is generated. In particular, iron rust samples show significant rusting and corrosion. It has been found that even in such a severe environment, the rust preventive sheet according to the present invention has a clear rust preventive effect.

  The above examples are those in which the rust-preventing function-imparting treatment based on the present invention is applied to a polyethylene cloth, and various materials such as natural fibers, chemical fibers, polyethylene sheets, and polypropylene sheets are used as the material of the rust-preventing sheet. The same effect was obtained even when used.

As described above, when iron products are stored for a short period of time, the present invention contributes greatly to industry because it is safe, hassle-free, and can more easily prevent rust.

Claims (2)

A rust prevention sheet for preventing or suppressing the occurrence of rust on iron products,
A rust-preventive sheet to which zinc powder is fixed and has flexibility or flexibility.   A rust prevention method comprising covering the rust prevention sheet according to claim 1 with at least a part of the steel product in contact with the steel product, thereby preventing or suppressing the generation of rust on the iron product.