JPS61159585A - Corrosion preventing tape - Google Patents

Abstract

PURPOSE:To enhance the corrosion preventing effect by sticking chips of metallic foil as a galvanic anode for electrolytic protection to part of a transparent plastic sheet coated with a pressure sensitive adhesive so as to also produce an electrochemical corrosion preventing effect as well. CONSTITUTION:One side 11 of a transparent or translucent plastic sheet 1 of polyethylene, PVC or the like is coated with a pressure sensitive adhesive 2, and chips 3 of metallic foil as a galvanic anode for electrolytic protection are continuously stuck to the part of the adhesive side. The resulting corrosion preventing tape T is wound around a metallic pipe P to prevent the permeation of water. Even when water permeates the tape T, the corrosion preventing effect is maintained because an electrochemical corrosion preventing effect is produced. Since the tape T is transparent, the chips 3 can be seen from the outside during winding, so the corrosion of the pipe is prevented easily and rapidly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a new anticorrosion tape having cathodic protection effects.

[Problems with conventional technology]

rJIS Z has traditionally been used as a corrosion-preventing material for various metal objects used in corrosive environments such as air, seawater, and soil.
1901 Anti-Corrosion Vinyl Adhesive Tape” and many other similar anti-corrosion tapes have been used.

These anti-corrosion tapes are wrapped during the manufacturing of metal products or on-site construction, but if the tape wrapping process is incomplete or after long-term use, water may enter from one part of the wrap and cause corrosion. .

For this reason, in order to improve the reliability of corrosion protection, methods are used to prevent water from entering by applying an undercoat or filler during tape wrapping, but this makes the work difficult and is not economical. .

On the other hand, there is a galvanic anodic method as a method for electrically protecting metal objects. In the galvanic anode method, a metal with a low electrode potential and excellent galvanic properties, such as magnesium, aluminum, zinc, or an alloy thereof (called a galvanic anode or sacrificial anode), is electrically connected to the metal object to be protected. The purpose is to protect metal objects from corrosion using the anti-corrosion current generated during this period. It is well known that when steel products are galvanized or coated with a highly concentrated zinc powder paint, corrosion prevention effects similar to those achieved by the galvanic anode method are produced based on this principle.

Now, conventional anti-corrosion tapes apply pressure-sensitive adhesives to stretchable plastic sheets such as polyethylene and polyvinyl chloride.
Both the water vapor transmission rate and the water absorption rate are small, and the permeation of water vapor or water from the sheet surface is extremely small compared to the infiltration from the wrap portion. Therefore, in order to prevent the occurrence of corrosion, it is sufficient to prevent moisture from entering through the wrap portion of the anticorrosion tape, but due to the structure of the tape winding, it is almost impossible to do this perfectly.

Therefore, it would be advantageous if the occurrence of corrosion could be prevented by electrolytic corrosion protection even if moisture infiltrated through the wrap portion of the anticorrosion tape.

[Purpose of the invention]

An object of the present invention is to provide an anti-corrosion tape that can prevent corrosion due to the effect of cathodic protection even if moisture infiltrates the metal object to be protected from corrosion through the flaps, tabs or sheet surface of the anti-corrosion tape.

[Structure of the invention]

That is, the anticorrosion tape according to the present invention is made by applying a pressure-sensitive adhesive to one side of a transparent or translucent plastic sheet, and continuously adhering small pieces of galvanic anode metal foil for cathodic protection to a part of the adhesive surface. This is a configuration characterized by the following.

[Explanation of Examples]

The present invention will be explained below with reference to the drawings.

FIG. 1 shows an embodiment of the anticorrosive tape according to the present invention. In FIG. 1, reference numeral 1 denotes a transparent or translucent long strip sheet made of polyethylene, polyvinyl chloride, or the like, and has stretchability. 2 is a pressure-sensitive adhesive (adhesive) applied to one side 11 of the sheet 10, and the adhesive is not normally transparent or translucent.
Ru. 3. . . . is a large number of corrosion-protective metal foil pieces made of cathodic protection galvanic anode metal foil (hereinafter referred to as anti-corrosion metal foil) made of zinc alloy, aluminum alloy, magnesium alloy, etc. 3. ... is an elliptical shape and its width is equal to or less than the width of the sheet 1,
It is continuously attached to the adhesive surface 11 of the sheet 1 in the longitudinal direction.

The anticorrosion tape T of the present invention having the above-mentioned structure is shown in FIG. This method is particularly suitable for wrapping with two pieces of anticorrosion metal foil toward the side.
If you wrap the stick with the side that is pasted first, you will get a small piece 3. ... is evenly pasted along the outer circumference of the pipe P in the longitudinal direction, and the 1 side where the small pieces 3° ... are not pasted has the effect of pressing and wrapping, and also prevents moisture from entering. Maintains the same effectiveness as conventional anticorrosion tape. In this case, since the sheet 1 is transparent or semi-transparent, a small piece of anti-corrosion metal foil 3. ... can be visually observed, so a small piece of anti-corrosion metal foil 5. It can be easily checked whether the tape is evenly attached to the outer periphery of the vibrator P, which facilitates the tape winding work and enables highly reliable anti-corrosion construction.

FIG. 5 shows another embodiment of the anti-corrosion tape according to the present invention, and this anti-corrosion tape To consists of three pieces of anti-corrosion metal foil attached to the adhesive surface 11 of the sheet 1 as shown in the figure. ...width L
2 is set to be less than or equal to % of the width of the sheet 10.

Note that in FIG. 5, constituent members having the same reference numerals as those in FIG. 1 indicate the same members as those in FIG. 1.

This anti-corrosion tape T. As shown in FIG. 4, this is particularly suitable for wrapping a metal object to be protected against corrosion, such as a metal pipe P, with a tape around the outer circumference in the longitudinal direction.

In the above, a small piece of anti-corrosion metal foil 3. . . . may be not only elliptical as shown in Figs. 1 and 3, but also any shape such as a circle, rectangle, diamond, etc., and the small pieces may be mutually arranged as shown in Figs. 1 and 5. In addition to being closely spaced, a predetermined distance may be maintained in advance. Note that when elliptical and circular pieces are used, since there are no protrusions such as corners, it is advantageous to prevent the tape from digging into the sheet 1 during winding.

The structure and practical aspects of the anticorrosive tape according to the present invention have been described above, and Table 1 shows examples of its preferred specifications.

Table 1 Examples of specifications for anti-corrosion tape Next, Invention 1 Regarding the anti-corrosion effect of this anti-corrosion tape, as mentioned above, it goes without saying that it has the same anti-corrosion effect as conventional anti-corrosion tape as long as there is no infiltration of moisture. The corrosion protection effect when water penetrates is determined by the effective potential of the corrosion protection metal foil and the amount of electricity generated as shown in Table 2.

Table 2 Effective potential and amount of electricity generated for anti-corrosion metal foil As is clear from Table 2, when comparing the effective potential and amount of electricity generated for each anti-corrosion metal foil, there is a difference between zinc-based, aluminum-based, and magnesium-based foils. Although there are differences, zinc-based or aluminum-based tapes are sufficient when applying this anticorrosive tape to steel products. When galvanizing steel products to prevent corrosion, JIS G 3442 galvanized steel pipes for water supply stipulates that the amount of zinc plating deposited per unit area is 0.06 P/am or more.

The anti-corrosion tape according to the present invention has a thickness of 0.
When attaching two gourds of zinc alloy foil, the weight is 0.14P/cm2 as shown in Table 2. Therefore, the amount of adhesion is approximately twice that of zinc plating, and if the ratio of the area to which the metal foil is pasted to the total surface area is taken as a bar, the amount of adhesion as a whole is equivalent to that of zinc plating. It also happens. In this way, in addition to the original corrosion-preventing effect of the anti-corrosion tape, the electrolytic protection effect of galvanizing is added, so the reliability regarding corrosion protection is significantly improved.

In addition, although polyethylene tape or polyvinyl chloride tape was used as the material for forming the plastic sheet in the above-mentioned case, the present invention is not limited to this, and for example, transparent or translucent material may be used. Of course, polyester tape or tetrafluoride resin tape may also be used. In this case, good heat resistance can be imparted to the anticorrosive tape, making it more effective in terms of properties.

〔Effect of the invention〕

The anticorrosive tape according to the present invention has the configuration as described above,
The tape's adhesion and adhesion properties provide the same anti-corrosion effect as conventional anti-corrosion tapes, and even if moisture infiltrates the metal object to be protected, the anti-corrosion effect will continue to be maintained due to the anti-corrosion effect of the galvanic anode metal foil for cathodic protection. can be done. Further, the tape winding operation is exactly the same as that for conventional anticorrosion tape, and no special techniques are required.

In particular, since the anticorrosive tape of the present invention has a transparent or translucent sheet of tape constituent material, when it is applied (wrapped), a small piece of anticorrosive metal foil stuck to the inner surface of the tape is passed through the sheet and exposed from the outside. It can be visually observed and it can be easily confirmed whether the metal foil pieces are evenly attached. Therefore, it is possible to perform tape winding work easily and quickly, and also to perform highly reliable anti-corrosion construction, which has great industrial value.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing one embodiment of the anticorrosive tape according to the present invention, Fig. 2 is a side view showing how the anticorrosive tape shown in Fig. 1 is used, and Fig. 3 is another example of the anticorrosive tape according to the present invention. FIG. 4+ is a plan view showing the actual male side, and FIG. 4 is a side view showing how the anticorrosion tape shown in FIG. 5 is used. In the figure, 1 is a plastic piece, 2 is a pressure-sensitive adhesive, and 3 is a small piece of gold maple foil for a galvanic anode for cathodic protection.

Claims (1)

[Claims] Corrosion protection characterized by coating a pressure-sensitive adhesive on one side of a transparent or translucent plastic sheet, and continuously pasting small pieces of galvanic anode metal foil for cathodic protection on a part of the adhesive surface. tape.