JPH025815A - Antifouling process for fishing net - Google Patents

Abstract

PURPOSE:To prevent the adhesion of marine life to a fishing net by producing a net with a blended yarn of copper and synthetic fiber and applying electric potential to the net. CONSTITUTION:A yarn is produced by blending a thin wire 2 of copper or a copper alloy with a nylon yarn 1 which is a kind of synthetic fiber. A fishing net 7 is produced by using said blended yarn. A battery 5 is connected to the net and an end of fishing net is used as an anode. A counter electrode 4 is placed in the fishing net. The applied electric potential is preferably 1-2V. Hydrogen ion is generated on the anode by the application of electric potential and the ion dissolves an insoluble oxide film of copper to expose the metal surface. Copper ion is dissolved in sea water to keep the antifouling effect over a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for preventing fouling of fishing nets underwater.

(Prior art and problems to be solved) Hitherto, fishing nets and stationary nets made of synthetic fibers have been used underwater, especially in the sea, but these nets tend to attract marine organisms (
As a result, the net becomes clogged, and in the case of Ikesu, the circulation of seawater worsens, causing fish to die due to lack of oxygen, and in the case of fixed nets, problems arise such as increased resistance to water currents and being swept away by the ocean current. was.

In order to solve these problems, it has been common practice to immerse fishing nets in antifouling agents such as organic tin compounds to make them impregnated, or to coat them with paint mixed with antifouling agents. was.

However, recently, the persistence of antifouling agents in fish bodies and environmental pollution caused by antifouling agents eluted into the water have become social issues, and the use of antifouling agents has become regulated. .

As a method to improve the antifouling properties of the net without using the above-mentioned antifouling chemicals, attempts have been made to make a cage using a wire mesh made of copper or a prepared alloy, but metal mesh is not flexible and is susceptible to waves, etc. Repeated stress concentrates locally,
The wire mesh may be torn in a short period of time, allowing fish to escape, the antifouling properties may be reduced due to the insoluble oxide film that forms on the metal surface, and even between some parts where the oxide film is missing and where the insoluble oxide film remains. Local batteries are formed, corrosion occurs locally, and defects such as tearing of the mesh easily occur (there were problems in practical use).

(Means for Solving the Problems) The present invention provides a fishing net antifouling method in which a potential is constantly or intermittently applied in water to a steel net made from a yarn made of a blend of copper and/or copper alloy and synthetic fibers. It is related to.

The present invention will be explained in detail below.

In the present invention, by constantly or intermittently applying electricity to the copper and/or copper alloy in the fishing net, the insoluble oxide film on the surface of the copper or copper alloy that is generated in water is dissolved by hydrogen ions generated by the anode reaction. The purpose is to make the active metal surface appear again and maintain the antifouling properties of copper or copper alloy.

The above reaction is expressed as follows.

Cu-Cu"+2e-+Cu(ON)2+2P +28
2P +CuD -Cu" +H20 The fishing net in the present invention is made using a material that is a blend of copper or copper alloy fine wire of an appropriate thickness and synthetic fibers such as nylon, which are normally used for fishing nets.

An example of the material used as the net is shown in FIG.

Here, 1 indicates nylon fiber, and 2 indicates copper or copper alloy fine wire.

The method of the present invention will be explained using Ikesu as an example.

Figure 2 shows a schematic diagram of Ikesu. Here, 3 is a buoy, 4
5 represents a cathode, 5 represents a power battery, 6 represents a switch, and 7 represents a fishing net.

First, one end of the fishing net is used as an anode, a cathode is provided as a counter electrode inside or outside the fishing net, and a small voltage is applied between them.

Generally, the applied voltage is preferably about 1 to 2 V, but applying too high a voltage is not preferred because chlorine gas will be generated.

The voltage is applied continuously or intermittently.

In addition, the cathode electrode may generate polarization resistance during energization, which may reduce the electrolytic reaction. Therefore, it is recommended to use a cathode electrode with a large surface area such as a fin structure that suppresses the generation of decomposition resistance, or to create a flow of water near the electrode. It is preferable to do so.

Moreover, it is also possible to use another electrode of the same structure as a counter electrode instead of the electrode.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples 1 and 2 Copper alloy (Cu:Ni=9:L) A 1m wire (Example 1) or a fine copper wire (Example 2) and a nylon thread were twisted together to form a wire (100X100X10) as shown in Figure 2.
0cm) was created.

The cathode electrode is L OOX 100 x 1.5 mm
A copper alloy plate (Cu:Ni=9:1) was used.

The above-mentioned ice cubes were immersed in Toba, Mie Prefecture, and a voltage of 1.5V0') was applied once every three months to examine the presence or absence of biofouling.

The results are shown in Table 1.

Comparative Examples 1 and 2 A cage coated with the antifouling agent (Comparative Example 1) or antifouling paint (Comparative Example 2) shown in Table 1 was immersed in the same location as in Example 1, and the state of attachment of organisms was examined. Ta.

The results are shown in Table 1.

Table 1 ○: No fixed biofouling △ 5 to 20% biofouling such as Japanese grass, blue laver, fujibo, Amanita, and sea squirt X: 20% or more of biofouling as above (effect of the invention) In the present invention, microcurrent By flowing constantly or intermittently, an active copper or copper alloy surface is always exposed, so that continuous elution of copper ions can be maintained, and therefore, antifouling properties can be maintained for a long period of time.

Also, like conventional antifouling paints, they can be used for a relatively short period of time (e.g.
There is no need to repaint it periodically (every 3 to 6 months), and there is no need to worry about toxicity or environmental pollution caused by antifouling agents.

Furthermore, since the net constructed according to the present invention has a more flexible structure than a net made only of metal, no stress is applied to the negative parts, and the durability can be greatly improved.

[Brief explanation of the drawing]

FIG. 1 shows a part of the fishing net of the present invention, and FIG. 2 is a schematic diagram of the present invention using a fishnet as an example. 1... Nylon thread, 2... Copper or copper alloy thin wire,
3...Buoy, 4...Counter electrode, 5...Battery, 6...Switch, 7...Fishing net.

Claims (1)

[Claims] An antifouling method for fishing nets, in which a potential is constantly or intermittently applied underwater to a net made from a yarn made of a blend of copper and/or copper alloy thin wires and synthetic fibers.