JPS6372891A - Corrosion resistant tape - Google Patents

Abstract

PURPOSE:To obtain the title tape capable of preventing corrosion even when water is infiltrated by coating an adhesive on one face of a long-sized plastic sheet, and continuously sticking the fine grains of a metal as the galvanic anode for electrolytic protection on one side edge of the coated face in specified width. CONSTITUTION:The pressure sensitive adhesive 2 is coated on one face of the drawable long-sized plastic sheet 1 of PE, PVC, etc. The fine grains 3 of the metal such as Mg and Al as the galvanic anode for electrolytic protection are continuously stuck on the width L2 adjacent to one side part of the coated face 2 with a small gap L1 in between in the lengthwise direction of the sheet to obtain the corrosion resistant tape T. When the corrosion resistant tape T is applied on a metallic pipe P to be protected, the coated face 2 is directed to the metallic pipe P, and the tape T is wound on the outer periphery of the pipe P at about 1/2 lapping rate in the lengthwise direction. As a result, the infiltration of water is prevented by the corrosion resistant tape T, the fine metal grains 3 function as the galvanic anode even when water is infiltrated, and the corrosion of the pipe P can be effectively prevented.

Description

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

(Prior art and problems) Conventionally, anti-corrosion materials for various metals used in corrosive environments such as air, seawater, and soil have been used [JIS Z1901
Anticorrosive Vinyl Adhesive Tape] Many other similar anticorrosive tapes have been used.

These anti-corrosion tapes are wrapped during the manufacture of metal products or on-site construction, but sometimes the tape winding process is incomplete, or after long-term use, moisture may enter the wrapped portion, causing corrosion. For this reason, in order to increase the reliability of corrosion protection, methods are used to prevent water from entering by applying an undercoat or filler during tape wrapping.
This makes work difficult and is not economical.

On the other hand, there is a flow anodic method as a method for electrically protecting metal objects. The current law is 1! A metal with a low electrode potential and excellent current characteristics, such as magnesium, aluminum, zinc, or an alloy thereof (called a current current anode), is electrically connected to the gold plate to be protected, and the corrosion current generated during this process causes the metal to The purpose is to prevent corrosion.

Conventional anti-corrosion tapes are made by coating a stretchable plastic sheet such as polyethylene or polyvinyl chloride with a pressure-sensitive adhesive, and both the water vapor permeability and water absorption rate are low, and the permeation of water vapor or water from the sheet surface is limited to the wrapped portion. This is extremely small compared to the invasion from Japan. Therefore, in order to prevent the occurrence of corrosion, it is sufficient to prevent moisture from entering from the wrap portion of the anticorrosion tape, but due to the structure of the tape winding, it is almost impossible to do this completely.

Therefore, it would be advantageous to prevent the occurrence of corrosion by electrolytic corrosion protection even if moisture enters through the wrap portion of the anticorrosion tape.

(Object of the Invention) The object of the present invention is to provide an anti-corrosion tape that can prevent corrosion due to its cathodic protection effect even if moisture intrudes into a metal object to be protected from corrosion through the wrap portion or sheet surface of the anti-corrosion tape. There is a particular thing.

(Structure of the Invention) That is, the anticorrosion tape according to the present invention has adhesive No. 11 applied to one side of a long plastic sheet, and a galvanic anode metal for cathodic protection is applied to a portion of a certain width adjacent to one side edge of the adhesive surface. This structure is characterized by the continuous attachment of microparticles.

(Description of Examples) The present invention will be described below with reference to figures and tables. FIGS. 1 and 2 show an embodiment of the anticorrosive tape according to the present invention. 1st
The figure is a plan view of the tape in this example, and FIG. 2 is a sectional view thereof. In Figures 1 and 2, 1 is a long stretchable plus deck sheet made of polyethylene, polyvinyl chloride, etc., and 2 is a pressure-sensitive adhesive (adhesive) applied to one side of the sheet 1. As these sheet 1 and pressure sensitive adhesive 2, anticorrosive vinyl adhesive tape of JIS Z1901 can also be used. 3 are minute metal grains of galvanic WQIi metal for cathodic protection made of magnesium, aluminum, zinc, or an alloy thereof, and these metal grains 3 are part of the adhesive surface 2 of the long plastic sheet 1;
Specifically, it is pasted continuously (approximately in close contact) in the longitudinal direction to a portion of constant width L2 adjacent to one side edge 4 with a slight gap L1 therebetween. For example, L and L2 are the width L of sheet 1.
-50 shoes, L=SIM1, L2-25sw.

The shape of the microparticles 3 of this galvanic anode may be any shape, but in order to avoid biting into the plastic sheet 1,
It is desirable to have a rounded shape with no sharp cuts or protrusions. In addition, the size of the fine particles 3 of this 11 anode is preferably small in order to avoid digging into the plastic sheet 1, but on the other hand, in order to maintain the effect of mmwA elm for a long period of time, the minimum necessary size is ensured. It must be. For example, when zinc particles are used as the fine particles of the galvanic anode, each particle has a G, 01 q (equivalent spherical diameter of about 0.14 jIl).
A certain amount of grain can be used. Incidentally, as a means for attaching the fine metal particles 3 to the adhesive surface 2 of the plastic sheet 1, for example, spraying using compressed air can be adopted.

Next, FIGS. 3 and 4 show a state where the tape is stretched at a predetermined elongation rate in an embodiment of the anticorrosive tape according to the present invention. FIG. 3 is a plan view thereof, and FIG. 4 is a sectional view thereof.

As shown in Fig. 3, the fine particles 3 of the anode are dispersed in the longitudinal direction as the plastic sheet 1 is stretched. Since the proportions are also equal, the electrolytic protection effect of the microparticles 3 is equally applied to each part.

As shown in FIG. 5, the anticorrosion tape T of the present invention having the above-mentioned structure has its adhesion surface in the longitudinal direction of the outer periphery of a metal object to be protected from corrosion, such as a metal pipe P, with its adhesion surface, that is, the adhesion surface of the microparticles 3 for galvanic restoration, facing the vibrator P. It is particularly suitable for winding the tape with an overlapping ratio of 1/2 toward the end of the tape.

In other words, if the side to which the galvanic anode microparticles 3 are attached is placed first and the tape is wrapped at a wrap rate of 1/2 while applying a predetermined tension, the galvanic anode microparticles 3 will wrap around the outer periphery of the pipe P. It has a shape that is evenly distributed and fixed in the longitudinal direction, and the side of flL4, where the microparticles are not attached, has a pressing effect, and is equivalent to conventional anticorrosion tape in terms of preventing moisture intrusion. The effect is retained. In this case, the microparticles 3 of the galvanic anode
is held in a crimped state to the metal pipe P by the surface pressure of the plastic sheet 1, so the electrical contact between the microparticles 3 and the metal pipe P is extremely good, and the cathodic protection effect is fully exerted. Ru. In other words, even if moisture enters the surface of the metal pipe from the wrap or sheet surface of the anticorrosion tape, the metal pipe will be damaged! The i-electrode and microparticles act as anodes to form a battery and generate anti-corrosion current, so as long as the microparticles exist, the surface of the metal pipe will not be corroded and the anti-corrosion state will continue to be maintained. .

An embodiment of the anticorrosion tape according to the present invention has been described above. By arbitrarily changing the adhesion width of the microparticles of the galvanic anode attached to the adhesive surface of the anticorrosion tape, the overlapping ratio of the tape can be reduced to 1/2.
It is also possible to configure the anticorrosive tape to be suitable for wrapping not only in wraps but also in 1/3 wraps, 1/4 wraps, etc., and all of these fall within the scope of the present invention.

Next, Table 1 shows preferred examples of specifications for the anticorrosive tape according to the present invention.

In the specification example shown in Table 1, this anti-corrosion tape is applied to the metal pipe, which is the metal object to be protected, with a wrap rate of 1/2 and an elongation rate of 10%.
When attached, the mold opening of the zinc grains fixed to the surface of the metal vibrator is approximately 0.049 in 1 d. This suspension is comparable to the adhesion of zinc when the surface of a metal pipe is galvanized. In this way, in addition to the original anticorrosion effect of the anticorrosion tape, an electrolytic protection effect equivalent to that of zinc plating is added, so that the reliability regarding corrosion protection is significantly improved.

Also, apply this anti-corrosion tape to a metal pipe at a predetermined elongation rate (vtm).
! ! In this case, the force required to pull the tape is almost the same as that for the conventional anti-corrosion tape mentioned above, and since the tape is made of fine zinc particles, the tape winding process requires less effort than when using small pieces of zinc foil. It is possible to achieve a smooth tightness against the tape, and the work is completely similar to that for conventional anti-corrosion tapes, and no special techniques or tools are required.

(Effects of the Invention) As described above, the anti-corrosion tape according to the present invention exhibits the same anti-corrosion effect as conventional anti-corrosion tapes due to the adhesiveness and adhesion of the tape, and even if moisture intrudes into the metal object to be protected, The anti-corrosion state can be maintained continuously due to the anti-corrosion effect of the fine particles of the anode metal for cathodic protection. In this way, there is an advantage in that reliability regarding corrosion protection can be significantly improved without any special construction techniques.

[Brief explanation of the drawing]

1 to 5 are explanatory diagrams showing one embodiment of the anticorrosive tape according to the present invention, FIG. 1 is a plan view of the anticorrosion tape in a natural state, and FIG. 2 is a sectional view of the tape. be. FIG. 3 is a plan view of the anticorrosive tape in a stretched state, and FIG. 4 is a sectional view thereof. Moreover, FIG. 5 is an explanatory diagram showing the winding state of the anticorrosive tape. In the figure, 1 is a plastic sheet, 2 is a pressure-sensitive adhesive, and 3 is minute particles of galvanic anode metal for cathodic protection.

Claims (1)

[Claims] Adhesive is applied to one side of a long plastic sheet, and microparticles of galvanic anode metal for cathodic protection are continuously attached to a certain width area adjacent to one side edge of the adhesive surface. Anticorrosive tape with special features.