JP2006241512A - Protective film for rust prevention and rust prevention method for metallic material using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique capable of easily, inexpensively and effectively performing rust prevention to a metallic material such as an iron material. <P>SOLUTION: The protective film for rust prevention comprises a metallic layer and an adhesive layer having a standard electrode potential lower than that of a metallic material as the body to be adhered, and, when being pasted on the metallic material as the body to be adhered, has a structure where the metallic material as the body to be adhered and the metallic layer are electrically contacted. Alternatively, the protective film for rust prevention comprises an adhesive layer including metal powder having a standard electrode potential lower than that of a metallic material as the body to be adhered on one side of a high polymer film, and has an adhesive layer shape and a blending amount of the metal powder, when being pasted on the metallic material as the body to be adhered, sufficient for allowing the metallic material as the body to be adhered and the metal powder to be electrically contacted and conducted. In the rust prevention method for a metallic material, each protective film is pasted on the surface of the metallic material via the adhesive layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a protective film for rust prevention and a rust prevention method for a metal material using the same. More specifically, the present invention relates to a protective film for rust prevention, which is bonded to the surface of a metal material such as an iron material to effectively prevent the rust of the metal material, and a metal material using the protective film. It relates to the rust method.

In general, when an iron material is exposed to the air, it is corroded from the surface and causes safety problems such as a decrease in strength. In particular, rust is generated on the lower surface of a vehicle body such as an automobile or a railcar due to adhesion of moisture, salt, or dust. Conventionally, rust prevention treatment of iron products has been generally performed by painting. However, it was not possible to prevent the occurrence of rust on the parts that could not be painted or on the parts of the iron surface such as cracks, scratches and pinholes. When the surface of the iron material is directly exposed to the outside air, the surface of the iron material becomes an anode due to the moisture and electrolyte that have entered, and rust is generated because the iron dissolves.
Once corrosion started from the part that could not be painted or from the part where the paint was peeled off, the corrosion progressed to the inside, so repainting had to be performed. In addition, corrosion from the inside also has a safety problem because discovery is likely to be delayed.

On the other hand, as an electrochemical anticorrosion method, a metal material having a lower potential in the ionization sequence than the metal material to be anticorrosive, that is, a metal body having a lower standard electrode potential than the metal material to be anticorrosive, such as Fe, Mg, Al , Zn and the like are electrically connected as sacrificial anodes, and a galvanic anode method is known in which a current generated by a battery action between the two is used as a corrosion-proof current.
In this galvanic anode method, metal ions are eluted together with current from the anode metal at a low potential. That is, the metal serving as the anode is corroded and becomes a sacrificial anode.
The metal anode for anticorrosion is a metal body having a standard electrode potential lower than that of the metal material to be protected (so-called electrochemically base metal body). There are magnesium alloy, high purity zinc, zinc alloy, aluminum alloy and so on.

With regard to corrosion prevention technology using such sacrificial anodes, as a corrosion prevention method for construction steel materials used in harsher environments, for example, for piles buried in the sea, for corrosion prevention treatment, by plating or welding on the iron surface It has been proposed to form a metal coating layer that is electrochemically lower than iron (see, for example, Patent Document 1).
However, this method requires plating and welding equipment and is applied only to specific applications.

JP 2000-45314 A

  An object of the present invention is to develop a technology capable of rust-proofing a metal material such as an iron material simply, inexpensively and effectively under such conditions.

  As a result of intensive research to achieve the above object, the present inventors have focused on a galvanic anode method using a sacrificial electrode as a corrosion prevention technique, and a metal having a standard electrode potential lower than that of an adherend metal material. By attaching a protective film having a layer and an adhesive layer, or a protective film having an adhesive layer containing a metal powder having a lower standard electrode potential than the adherend metal material, to the surface of the adherend metal material, We found that we could achieve that goal. The present invention has been completed based on such findings.

That is, the present invention
(1) It has a metal layer having a lower standard electrode potential than the adherend metal material and an adhesive layer, and the adherend metal material and the metal layer are electrically connected to each other when bonded to the adherend metal material. A protective film for rust prevention, characterized by having a structure in contact with
(2) When having a polymer film, a metal layer having a standard electrode potential lower than the adherend metal material sequentially provided on one surface thereof, and an adhesive layer, and pasting the adherend metal material, A protective film for rust prevention, wherein the adherend metal material and the metal layer have a structure in electrical contact;
(3) In the above item (1) or (2), the adherend metal material is an iron material, and the metal layer is a layer composed of at least one selected from zinc, aluminum, magnesium and alloys thereof. Protective film for rust prevention,
(4) The protective film for rust prevention according to any one of (1) to (3) above, wherein the surface of the metal layer has irregularities and has an adhesive layer in the concave portion.

(5) The protective film for rust prevention according to the above (4), wherein the surface of the metal layer has linear irregularities, and the adhesive layer is provided in the linear concave portion,
(6) The protective film for rust prevention according to any one of (1) to (3) above, wherein the surface of the metal layer has convex portions scattered in a polka dot shape and has an adhesive layer on the non-convex portion. ,
(7) The adherent metal has an adhesive layer containing a metal powder having a standard electrode potential lower than that of the adherend metal material on one surface of the polymer film, and is bonded to the adherend metal material. A protective film for rust prevention, characterized in that the material and the metal powder have sufficient shape of the adhesive layer and the blending amount of the metal powder to make electrical contact and conduction,
(8) Rust prevention as described in the above item (7), wherein the adherend metal material is an iron material, and the metal powder is a powder comprising at least one selected from zinc, aluminum, magnesium and alloys thereof. A protective metal film, and (9) a metal material, wherein the protective film for rust prevention according to any one of (1) to (8) above is bonded to the surface of the metal material via an adhesive layer Rust prevention method,
Is to provide.

  According to the present invention, a protective film for rust prevention which is bonded to the surface of a metal material such as an iron material and effectively prevents the rust of the metal material, and a rust prevention method for a metal material using the protective film. Can be provided.

The protective film for rust prevention of the present invention has the following three aspects.
The first aspect includes a metal layer having a standard electrode potential lower than that of the adherend metal material and an adhesive layer, and the adherend metal material and the metal layer are bonded to the adherend metal material. Protective film for preventing rust (hereinafter referred to as protective film I for rust prevention) having a structure in electrical contact with the polymer film, and a second aspect is a polymer film and an adherend metal provided in order on one surface thereof. It has a metal layer having a lower standard electrode potential than the material and an adhesive layer, and has a structure in which the adherend metal material and the metal layer are in electrical contact when bonded to the adherend metal material. The anticorrosive protective film (hereinafter referred to as anticorrosive protective film II) and the third aspect are adhesives comprising a metal powder having a lower standard electrode potential than the adherend metal material on one side of the polymer film. When the adhesive layer is bonded to the adherend metal material, the adherend metal material and the gold Powder and is in electrical contact, an anticorrosive protective film having the amount of shape and the metal powder a sufficient adhesive layer to conduct (hereinafter, referred to as Anti-corrosive protective film III.).

The metal layer used for the protective films I and II for rust prevention and the metal powder used for the protective film III for rust prevention is a standard electrode rather than the adherend metal material (rust prevention metal material). A metal body (sacrificial anode material) with a low potential is used. Here, the standard electrode potential refers to the electrode potential when a metal is immersed in a solution containing the metal ions and the standard hydrogen electrode (platinum immersed in a 1N HCl solution in contact with hydrogen gas at 1 atm. Electrode) expressed as a difference from the potential.
The standard electrode potential of each metal at a temperature of 25 ° C. is, for example, Mg: −2.37 V, A1: −1.66 V, Zn: −0.763 V, Fe: −0.440 V.
Therefore, when the adherend metal material is an iron material, the metal body (sacrificial anode material) constituting the metal layer or metal powder is at least one selected from zinc, aluminum, magnesium, and alloys thereof. Seeds can be used.

As zinc, high purity zinc or a Zn-based alloy obtained by adding Cd or Al to high purity zinc can be used. Aluminum has a larger theoretically generated amount of electricity per unit mass than zinc and magnesium and is preferable as a sacrificial anode material. However, since aluminum itself is covered with an oxide film and its anticorrosive action is reduced, In order to prevent the formation, an aluminum alloy obtained by adding In or Si and activating the surface is preferable. In addition, an Al—Zn—In alloy can also be preferably used. As magnesium, a high purity product or a magnesium-based alloy containing Al, Zn, Mn, or the like can be used. The zinc-based alloy, aluminum-based alloy, and magnesium-based alloy can contain iron or a metal having a higher standard electrode potential than iron as long as the standard electrode potential of the alloy itself is lower than iron. .
In addition, since magnesium powder is easy to ignite, it is preferable to use zinc powder, zinc base alloy powder, and aluminum base alloy powder as a metal powder from the surface of the safety | security of work.

In the protective films I and II for rust prevention according to the present invention, a metal layer composed of the above-mentioned metal body is provided as a sacrificial anode. The metal layer may be formed in a film shape and rolled. Foil, electrolytic foil, etc. can be used. Although there is no restriction | limiting in particular in the thickness of the said metal layer, When sticking property etc. with respect to a to-be-adhered metal material are considered, about 5-70 micrometers is preferable and 15-45 micrometers is more preferable.
In the present invention, the metal layer preferably has a structure in which the surface of the metal layer has irregularities and an adhesive layer is formed in the concave portion. With such a structure, when the protective films I and II of the present invention are bonded to the adherend metal material, the adherend metal material and the convex portion of the metal layer are in electrical contact with each other. Can do.

The shape of the unevenness is not particularly limited, but a structure having a linear unevenness on the surface and an adhesive layer in the recessed portion is preferable. Moreover, in this invention, the surface etc. which have the convex part which the surface was scattered in the shape of a polka dot, and have an adhesive bond layer in the non-convex part can be used preferably.
FIG. 1 is a schematic diagram showing an example of a structure in which the surface of a metal layer has linear irregularities and an adhesive layer is provided in the concave portions in the protective films I and II for rust prevention of the present invention, FIG. 2 is a schematic view showing an example of a structure in which the surface of the metal layer has convex portions scattered in a polka dot shape and an adhesive layer is formed on the non-convex portion in the protective films I and II for rust prevention of the present invention. FIG. In FIGS. 1 and 2, 2 is an adhesive layer and 4 is a metal layer.

On the other hand, in the protective film III for rust prevention of this invention, the metal powder comprised from the above-mentioned metal body is contained in an adhesive bond layer as a sacrificial anode. In this case, when the protective film III is bonded to the adherend metal material, the adherend metal material and the metal powder are in electrical contact with each other, and the shape of the adhesive layer and the metal are sufficient for electrical conduction. It is necessary to have a powder loading.
There is no restriction | limiting in particular in the shape of metal powder, Any, such as a grinding | pulverization powder, a scale-like powder, a spherical powder, may be sufficient. The average particle size is usually about 0.5 to 70 μm, preferably 1 to 40 μm. Moreover, it is preferable that content of the metal powder in an adhesive bond layer is about 80-97 mass%. When the content of the metal powder is in the above range, the conductivity in the thickness direction is sufficient and the adhesive strength is also good.

There is no restriction | limiting in particular about the polymer film used in the protective film II and the protective film III of this invention, What consists of various raw materials can be mentioned. Specific examples include polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, polyamide resins, polyvinyl alcohol resins, and polyvinyl chloride resins. Among these films, Considering treatment after use and economic efficiency, a film containing a polyolefin resin such as polyethylene or polypropylene as a main component is preferable.
Although there is no restriction | limiting in particular in the thickness of this polymer film, Usually, 10-300 micrometers, Preferably it is 20-150 micrometers. This polymer film can contain an antioxidant, a weather resistance improver, a lubricant, an inorganic filler, a colorant, and the like as required.

There is no restriction | limiting in particular in the adhesive agent which comprises the adhesive bond layer in the protective films I, II, and III for rust prevention of this invention, For example, various adhesive agents, such as a pressure sensitive adhesive (adhesive), an epoxy resin, an isocyanate resin, etc. are included. Reactive adhesives, hot-melt adhesives including vinyl acetate resins, polyamide resins, polyester resins, etc., or emulsion adhesives can be used. In view of this, a pressure sensitive adhesive is preferred.
As this pressure-sensitive adhesive, for example, an arbitrary one can be appropriately selected from those conventionally used for pressure-sensitive adhesive layers in surface protective pressure-sensitive adhesive sheets such as metal plates. For example, acrylic pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, polyurethane-based pressure-sensitive adhesives, polyester-based pressure-sensitive adhesives, and the like can be used. A rubber-based pressure-sensitive adhesive is preferable, and an acrylic pressure-sensitive adhesive is particularly preferable from the viewpoint of weather resistance.

In the present invention, the thickness of the adhesive layer is usually about 1 to 50 μm, preferably 5 to 30 μm.
In the protective film for rust prevention of this invention, when an adhesive bond layer is an adhesive layer, a peeling sheet can be provided on it as needed. Examples of the release sheet include paper substrates such as high-quality paper, glassine paper, and coated paper, laminated paper obtained by laminating a thermoplastic resin such as polyethylene on these paper substrates, or polyethylene terephthalate, polypropylene terephthalate, and polyethylene naphthalate. Polyester film such as polypropylene film and polyolefin film such as polypropylene, polyethylene, etc., which includes a release agent layer such as a silicone resin coated with a release agent layer, etc. There are no particular restrictions on the thickness of this release sheet Although it is not, it is usually about 30 to 150 μm.
This release sheet is usually peeled off when the protective film for rust prevention of the present invention is applied to an adherend metal material.

The present invention also provides a method for rust prevention of the metal material by attaching the protective film (I, II, III) of the present invention to the surface of the metal material via an adhesive layer. To do.
The metal material of the adherend to which the method of the present invention is applied is preferably an iron material such as a steel plate. By attaching the protective film for rust prevention of the present invention to the surface of the metal material, for example, the coating film of the metal material is broken to expose the metal material portion, and the aqueous solution in which moisture and carbon dioxide in the air are dissolved. Even when the local battery is formed via the metal body, the metal body having a standard electrode potential lower than that of the metal material serves as a sacrificial anode, so that the elution of the metal material body can be prevented.

FIG. 3, FIG. 4, and FIG. 5 are schematic views showing different examples when the protective film for rust prevention of the present invention is attached to the surface of a metal material.
FIG. 3 shows a case where a protective film I for rust prevention partially having the structure shown in FIG. 1 is attached to the surface of the metal material. The metal layer 4 is attached to the surface of the metal material 1 via the adhesive layer 2. The provided state is shown.
FIG. 4 shows a case where a protective film II for rust prevention having the structure shown in FIG. 1 is attached to the surface of the metal material. The metal layer 4 and the polymer are bonded to the surface of the metal material 1 via the adhesive layer 2. The state in which the film 5 was provided in order is shown.
FIG. 5 shows a case where a protective film III for rust prevention is pasted on the surface of the metal material, and a state in which the polymer film 5 is provided on the surface of the metal material 1 through an adhesive layer 2 ′ containing the metal powder 3. Indicates.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, evaluation of rust prevention property was performed by the method shown below.
<Rust prevention evaluation>
As shown in FIG. 6, a protective film is pasted on an iron plate having a thickness of 2 mm, a length of 200 mm, and a width of 30 mm, leaving a groove with a width of 1 mm, and left for 240 hours under conditions of 40 ° C. and 95 RH%. The state was visually observed to confirm the presence or absence of rust.
In FIG. 6, reference numeral 1 ′ is an iron plate, and 10 is a protective film (the layer configuration of the protective film is not shown).

Example 1
Zinc foil with a surface irregularity of 99.99% or more in purity (length from the bottom to the top of the ridge is 35 μm, width of the ridge is 2 mm, depth of the groove is 10 μm, A pressure-sensitive adhesive layer was formed on the concave groove portion having a width of 2 mm using an acrylic pressure-sensitive adhesive, and the protective film for rust prevention shown in FIG. 1 was produced.
Next, as shown in FIG. 3, this protective film for rust prevention was affixed on the iron plate surface, and the rust prevention property was evaluated. As a result, no rust was observed.

In Example 1, a protective film for rust prevention was produced in the same manner as in Example 1 except that a polypropylene film having a thickness of 50 μm was laminated on the side opposite to the linear unevenness of the zinc foil.
Next, as shown in FIG. 4, this protective film for rust prevention was affixed on the iron plate surface, and rust prevention property was evaluated. As a result, no rust was observed.

Example 3
In the acrylic pressure-sensitive adhesive, zinc powder having an average particle diameter of 10 μm having a purity of 99.99% or more is added so as to be 90% by mass based on the total solid content, and this is used to form a polypropylene film surface having a thickness of 50 μm. A pressure-sensitive adhesive layer having a thickness of 20 μm was formed to produce a protective film for rust prevention.
Next, as shown in FIG. 5, this protective film for rust prevention was affixed on the iron plate surface, and the rust prevention property was evaluated. As a result, no rust was observed.
Comparative Example When the protective film was not provided and the rust prevention property was evaluated only for the iron plate, generation of rust was observed.

  The protective film for rust prevention of the present invention can be easily bonded to the surface of a metal material such as an iron plate, and can prevent the occurrence of rust in the metal material at low cost and effectively.

In the protective film for rust prevention of this invention, it is a schematic diagram which shows an example of a structure of a metal layer and an adhesive bond layer part. In the protective film for rust prevention of this invention, it is a schematic diagram which shows the example from which the structure of a metal layer and an adhesive bond layer part differs. It is a schematic diagram which shows an example at the time of sticking the protective film for rust prevention of this invention on the surface of a metal material. It is a schematic diagram which shows a different example at the time of sticking the protective film for rust prevention of this invention on the surface of a metal material. It is a schematic diagram which shows the further different example at the time of sticking the protective film for rust prevention of this invention on the surface of a metal material. It is explanatory drawing which shows the rust prevention evaluation method of the protective film for rust prevention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal material 1 'Iron plate 2, 2' Adhesive layer 3 Metal powder 4 Metal layer 5 Polymer film 10 Protection film for rust prevention

Claims (9)

  It has a metal layer and an adhesive layer whose standard electrode potential is lower than that of the adherend metal material, and the adherend metal material and the metal layer are in electrical contact when bonded to the adherend metal material. The protective film for rust prevention characterized by having the structure to do.   A polymer film, a metal layer having a standard electrode potential lower than that of the adherend metal material sequentially provided on one surface thereof, and an adhesive layer, and when the laminate is bonded to the adherend metal material, A protective film for rust prevention characterized by having a structure in which an adherend metal material and a metal layer are in electrical contact.   The protective film for rust prevention according to claim 1 or 2, wherein the adherend metal material is an iron material, and the metal layer is a layer composed of at least one selected from zinc, aluminum, magnesium or an alloy thereof. .   The protective film for rust prevention according to any one of claims 1 to 3, wherein the surface of the metal layer has irregularities, and an adhesive layer is provided in the concave portion.   The protective film for rust prevention according to claim 4, wherein the surface of the metal layer has linear irregularities, and the adhesive layer is provided in the linear concave portion.   The protective film for rust prevention according to any one of claims 1 to 3, wherein the surface of the metal layer has convex portions scattered in a polka dot shape and has an adhesive layer on the non-convex portion.   An adhesive layer containing a metal powder having a standard electrode potential lower than that of the adherend metal material is provided on one surface of the polymer film, and the adherend metal material and the metal are bonded to the adherend metal material. A protective film for rust prevention characterized by having an adhesive layer shape and a blending amount of metal powder sufficient to make electrical contact and conduction with the powder.   The protective film for rust prevention according to claim 7, wherein the adherend metal material is an iron material, and the metal powder is a powder composed of at least one selected from zinc, aluminum, magnesium and alloys thereof. A rust prevention method for a metal material, comprising attaching the protective film for rust prevention according to any one of claims 1 to 8 to the surface of the metal material via an adhesive layer.

Images