JP6295862B2 - Antifouling plated steel wire for underwater net and underwater net manufactured from the plated steel wire - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a plated steel wire used mainly for aquaculture ginger nets used in the sea, and a wire net produced therefrom.

  Up to now, nets made from chemical fibers and plated steel wires have been used for aquaculture ginger, but when used in the sea for a long time, seaweeds, shellfish, etc. will adhere to the net, blocking the mesh, There is a concern that the fish in the net may be deficient due to insufficient seawater exchange in the net.

  Conventionally, the ginger net is periodically landed to remove attached seaweed and shellfish. Furthermore, an anti-algae agent containing Cu, Ag, Zn or the like has been applied as necessary. In particular, Cu elutes into the sea as Cu ions, and when it comes into contact with larvae such as algae and shellfish, it binds to enzymes and proteins, lowers its activity, and inhibits metabolic functions. Furthermore, it is considered that a part of oxygen in the air or the sea is activated by the catalytic action of these Cu ions, and this suppresses the propagation of seaweed and shellfish by decomposing organic matter in the larvae.

  However, regular application of antifouling agents to ginger nets is labor intensive and costly, and these antifouling agents elute excess Cu ions into the sea and remain inside the fish, In addition to concerns about growth disorders and adverse effects on the human body that ate the fish, there are also concerns about adverse effects on natural marine life due to marine contamination of Cu ions. Therefore, the elution of Cu ions should be limited to the extent that there is a minimum amount in the vicinity of the plating material that forms the ginger net and prevents adhesion of seaweed and shellfish to the plated steel wire.

  As a means to solve these problems, Non-Patent Document 1 discloses a tween having a diameter of 2 mm of polyamide / polyamide elastomer bunred fiber in which cuprous oxide, an organic zinc compound, and an organic copper compound are kneaded as a raw material for a ginger net. Although it has been disclosed that it has an effect of preventing adhesion of seaweed and shellfish, the adhesion of shellfish tends to increase after 20 weeks or more in the sea. When a compound is kneaded, there are problems such as a decrease in tensile strength. In particular, a decrease in the tensile strength of the material is a major problem that leads to the disconnection of the ginger net in the sea and the loss of cultured fish.

  In Patent Document 1, in the case of a chemical fiber as in Non-Patent Document 1, as Cu ions elute, fine irregularities are generated at the site where Cu and Zn compounds are present on the surface of the chemical fiber, and roots such as seaweed and shellfish are generated. However, it is pointed out that the ease of tension is a factor that cannot be used for a long time in the sea. As means for solving these problems, in Patent Document 1, for example, a polyester resin, nylon resin, polyethylene resin, or polypropylene resin having a diameter of 1 to 4 mm is used as a core wire, and a copper or copper alloy plate is bent on a cylinder, It is disclosed that a core wire is covered and a side edge portion of a plate material is joined by friction stir welding or the like to be a raw material for a ginger net. Since this antifouling material does not knead the Cu and Zn compounds in the synthetic resin, the tensile strength of the synthetic resin is not adversely affected, and from the Cu and Cu alloy layer on the surface, the entire surface in contact with the sea Since Cu ions elute uniformly from the outer surface, the entire outer metal layer becomes thinner as the copper ions elute, and it is disclosed that the surface is always kept in a smooth state for a long time even in the sea. Yes. However, since the Cu plate material is expensive and the manufacturing process of the material is complicated, a lower cost antifouling material is desired.

JP 2009-11242 A

Kato Kazumi et al., “Development of Algae-proof Fiber”, Mikawa Textile Technology Center Research Report (2002)

  An object of the present invention is to provide a plated steel wire capable of preventing contamination by seaweed and shellfish adhering to a ginger net at a low cost and preventing it for a long period of time in aquaculture in the ocean, and a wire mesh manufactured from the plated steel wire. And

  The present invention has been made in view of the circumstances as described above. The purpose of the present invention is to prevent contamination by seaweed and shellfish attached to a ginger net for a long period of time in aquaculture in the ocean. In addition, the inventors have found out that an antifouling effect can be exhibited by utilizing a plated steel wire containing Cu in a Zn plating or Zn alloy plating layer.

  The principle is that in order to utilize Zn, which is cheaper than Cu and expected to have an antifouling effect in the sea, in addition to applying hot-dip Zn or hot-dip Zn alloy-plated steel wire, In combination with Zn ions eluted by Zn sacrificial anti-corrosion mechanism in the sea, a large antifouling effect can be obtained by eluting an appropriate amount of Cu ions to suppress adhesion of algae and shellfish to the net. It can be demonstrated.

  Furthermore, since Zn and Cu of the surface layer are eluted from the entire surface in contact with the sea, there is no generation of fine irregularities as in the case of kneading the Cu compound to the chemical fiber. The antifouling effect can be maintained.

This invention is made | formed based on the said knowledge, The place made into the summary is as follows.
(1) A plated steel wire having a hot-dip galvanized layer in which the average composition is mass% and Fe is 2% or less, the balance is made of Zn and inevitable impurities, and Cu is dispersed,
A plated steel wire containing Cu in a plating layer, wherein the area index of a region of 10% or more is 2% or more and 35% or less in terms of Cu mass% on the surface of the plating layer.
The area index is a square area of 1/4 length of the wire diameter in the plating layer surface as a measurement area by a scanning electron microscope (SEM) and an energy dispersive composition analyzer (EDS) attached thereto. Is measured at three locations, and the area of 10% or more of the area is measured by Cu mass%, which is divided by the total measurement area and expressed in%.
(2) The plated steel wire according to (1) above, wherein the average composition of the hot-dip plated layer is further contained by mass% and Al: 60% or less.
(3) The plated steel containing Cu in the plating layer according to (1) above, wherein the average composition of the hot-dip plating layer is further contained by mass, Al: 20% or less, and Mg: 5% or less. line.
(4) A wire mesh manufactured from a plated steel wire containing Cu according to any one of (1) to (3) in a plating layer.

  As in the present invention, by applying a steel wire in which Cu is dispersed in a hot dip Zn plating or hot dip Zn alloy plating layer to an underwater aquaculture net, an appropriate amount of Cu ion in addition to Zn ion is eluted to the vicinity of the net. Because it is possible to suppress the attachment of shellfish to the aquaculture net over a long period of time, in addition to reducing labor and costs in the fishery farmed in the ocean, it also helps to ensure the safety of seafood and the marine environment. Because it contributes, its effect on industry is great.

It is a SEM-EDS analytical composition map which shows the area | region of Cu mass: 10% or more of the surface which disperse | distributed Cu to the Zn alloy plating wire.

  The present invention is characterized in that Cu is dispersed in Zn plating or Zn alloy plating wire. First, the reasons for limiting the Cu dispersion will be described.

  First, the plating layer is observed with a scanning electron microscope (SEM) and an energy dispersive composition analyzer (EDS) associated therewith. The distribution state of Cu on the surface of the plating layer is performed on the composition map of the plating layer on the surface of the steel wire collected by EDS. As a measurement area, measure a square area with a quarter length of the wire diameter at arbitrary three points, and divide the area of the area of 10% or more by the total area of Cu by mass% and display it as a percentage. do.

  In actuality, quality can be easily controlled by surface Cu analysis of the plated steel wire, and the value in industrial production is great.

  The plated steel wire of the present invention can be manufactured, for example, by the following method. The Zn plating or Zn alloy plated steel wire is subjected to Cu displacement plating treatment or Cu electroplating treatment, and then heat treated at a temperature of 500 to 650 ° C. to diffuse Cu into the Zn plating layer.

  Also, Zn plating and Zn alloy plating steel wires are heat treated at a temperature of 500 to 650 ° C. with a Cu / Zn alloy plating solution containing a chelating agent such as tartaric acid, and then plated with Cu. Process to diffuse to the layer.

  As a result, Cu penetrates into the Zn plating and Zn plating alloy plating. In order to effectively exhibit the antifouling effect of the plated steel wire, the present inventors have made Cu on the surface of the plated steel wire. It has been found that it is effective to control the area ratio.

  In other words, since Cu penetrates into the plating layer in proportion to the presence of Cu on the plating surface, when used as a ginger metal mesh, Cu ions are also in proportion to Cu in proportion to dissolution of the Zn plating layer. In proportion to the presence of the plating surface, it dissolves into the sea and exhibits an algal control effect.

  Cu mass on the surface of Zn plating and Zn alloy plating: The area index of the region of 10% or more is specified to be 2% or more and 35% or less. When used as a net in the sea, the Cu ion elution amount is insufficient, and the antifouling effect cannot be obtained. This is because it has been clarified that the effect is saturated even if the content exceeds 35%. By adjusting the liquid concentration at the time of Cu displacement plating treatment, Cu electroplating treatment or brass plating treatment, current density of electroplating, etc., the area index can be within the range of the present invention.

  FIG. 1 shows an example in which a 1 mm × 1 mm square area of a surface diffused at 560 ° C. is measured after Cu is electroplated on a φ-10 mm Zn-10% Al alloy plated wire. A region where Cu is 10% or more is present in an amount of 9.7%, which is within the scope of the present invention, and has good corrosion resistance and anti-algae properties.

  The plated steel wires used for aquaculture nets are based on Zn-plated steel wires in anticipation of anti-fouling effects, but they are used in subsea environments. It is preferable to use Zn alloy plating to which Al and Mg are added in view of durability, particularly corrosion resistance. Hereinafter, “%” means “% by mass” with respect to the component content.

  Fe may be eluted from the steel during plating, or may be present as an impurity in the plating base metal, but if it exceeds 2%, the corrosion resistance decreases. Therefore, 2% was made the upper limit. In addition, although the minimum in particular is not provided in the addition amount of Fe, depending on the case, it is not necessary to contain Fe.

  In alloy plating in which Al is added to Zn, the amount of Al added is regulated to 60% or less. Al has an effect of improving the corrosion resistance, and the effect is effectively exhibited at 1% or more. On the other hand, when an amount exceeding 60% is added, the plating layer becomes brittle and induces plating cracking, peeling, and the like. Therefore, in the alloy plating in which Al is added to Zn, the addition amount of Al is regulated to 60% or less. In addition, since corrosion resistance equivalent to a Zn plating wire is ensured, there is no particular lower limit on the amount of Al added.

  Furthermore, when Mg is added to the alloy plating in which Al is added to Zn, the corrosion resistance can be further improved. However, since the plating layer is cured when Mg is added, there is an optimum amount of Al added when Mg is added.

  In the Zn—Al—Mg alloy plating, the additive amount of Al is regulated to 20% or less. Al has an effect of improving corrosion resistance. However, when Mg is added in addition to Al, when an amount of Al exceeding 20% is added, the plating layer becomes brittle and induces plating cracking, peeling, and the like. . Therefore, in the Zn—Al—Mg alloy plating, the additive amount of Al is regulated to 20% or less. In addition, since corrosion resistance equivalent to a Zn plating wire is ensured, there is no particular lower limit on the amount of Al added.

  In Zn—Al—Mg alloy plating, the amount of Mg is regulated to 5% or less. Mg has the effect of improving corrosion resistance by promoting the growth of uniform corrosion products and preventing the progress of local corrosion. The effect is exhibited effectively at Mg: 0.1% or more. On the other hand, when the amount of Mg exceeds 5%, the Fe—Zn alloy layer is markedly cured, and cracks and peeling occur in the Fe—Zn alloy layer. Therefore, in the Zn—Al—Mg alloy plating, the amount of Mg is regulated to 5% or less. In addition, since the corrosion resistance equivalent to Zn plating wire or Zn-Al alloy plating is ensured, there is no particular lower limit on the amount of Mg added.

  Inevitable impurities in the plating layer are inevitably mixed into the plating layer from various elements in the plating line, particularly from the plating bath. There are various inevitable impurities such as those that are harmful to corrosion resistance, those that are harmful to the workability when fine particles are mixed, and those that have unknown effects, such as C, P, S, O, N. and so on.

The adhesion amount of the galvanized layer on the plated steel wire is preferably 300 g / m ² or more, and preferably 500 g / m ² or more if possible.

  The wire mesh produced by using the plated steel wire of the present invention described above, by applying this wire mesh as an underwater aquaculture net, elutes an appropriate amount of Cu ions in addition to Zn ions to the vicinity of the net, to a culture net for algae and shellfish Since it is possible to suppress the adhesion of seawater for a long period of time, in addition to reducing labor and costs in fisheries cultivated in the ocean, it can also contribute to food safety of marine products and conservation of the marine environment.

  Examples are shown below. In addition, this Example demonstrates along a specific example, The content of the claim of this invention is not limited.

As a plated steel wire constituting the wire mesh, a steel wire having a diameter of 4 mm and a galvanized layer having a plating adhesion amount of 400 g / m ² was prepared. The plating conditions for the plating layer are as shown in Table 1.

  As a test method to evaluate the antifouling effect when using a net in the sea, after using it for 6 months in the sea for a period of 4 to September, pull it up, and the mass per unit surface of seaweed and shellfish attached to the net Comparative evaluation was made. As an antifouling index, a net produced from a normal Zn-plated steel wire is used as a comparative material, specifically, the adhesion amount of seaweed and shellfish in Comparative Example 13 (normal Zn-plated steel wire net) in Table 1 is 100. evaluated.

  Corrosion resistance of Zn plating and Zn alloy plating was evaluated by corrosion weight loss after use in the sea for a period of 4 to 6 months. Specifically, the corrosion loss index of Comparative Example 13 (ordinary Zn-plated steel wire) in Table 1 was evaluated as 100 as the corrosion resistance index.

  The method of mixing Cu into the plated steel wire was manufactured by a method of performing thermal diffusion after the aforementioned Cu displacement plating, Cu electroplating or brass plating treatment. By changing the plating solution concentration and the current density of electroplating, the Cu area ratio on the surface of the Zn plating layer was variously changed.

  Table 1 shows the production results. 1 to 12 in Table 1 are examples of the present invention, and others are comparative examples. In the present invention example, since the Cu area ratio on the surface of the Zn plating layer is within the definition of the present invention, a high antifouling effect is exhibited. In addition, a Zn alloy plated wire to which Al and Mg are added has alga-proof properties while achieving higher corrosion resistance than an additive-free Zn plated wire.

  On the other hand, in the comparative example, even when the Zn plating layer and the Zn alloy plating layer are within the scope of the present invention, the antifouling effect is reduced if the Cu area ratio on the surface of the Zn plating layer is outside the scope of the present invention. .

  Moreover, even if the Cu area ratio on the surface of the Zn plating layer is within the limits of the present invention, high corrosion resistance cannot be obtained with Zn alloy plating unless the Al and Mg contents are within the scope of the present invention. Rather, it declines.

  Comparative Example 13 is a normal Zn-plated wire that has not been subjected to any algal control treatment, and has an algal control index and a corrosion resistance index of 100, respectively.

  In Comparative Example 14, the Zn plating wire was subjected to Cu displacement plating treatment or Cu electroplating treatment, and then heat treated at a temperature of 550 ° C. to diffuse Cu into the Zn plating layer. Since the index is out of the lower limit of the present invention, the algae preventive effect is small.

  In Comparative Example 15, a Zn plating wire was subjected to a brass plating treatment with a Cu / Zn alloy plating solution containing a tartrate chelating agent, and then heat-treated at a temperature of 550 ° C., whereby Cu was converted into a Zn plating layer. Although the process which spread | diffuses was performed, since a Cu area rate remove | deviates from the minimum of this invention, an algal control effect is small.

  In Comparative Example 17, the Fe content of the Zn plating exceeds 2% of the upper limit of the present invention, the corrosion resistance is poor, the algae grows on the cracked and peeled portions of the plating, and the high algal protection effect is small.

  In Comparative Example 18, the Cu area ratio exceeded 35% of the upper limit of the present invention in the Zn-plated wire, and the algae prevention effect was saturated.

  In Comparative Example 19, the Al content of the Zn—Al alloy plating exceeds 60% of the upper limit of the present invention, the corrosion resistance is poor, the algae propagates in the cracked and peeled portions of the plating, and the high effect of preventing algae is small. . In Comparative Example 20, the Fe content of the Zn—Al alloy plating exceeds 2% of the upper limit of the present invention, the corrosion resistance is poor, the algae propagates in the cracked and peeled portions of the plating, and the high effect of preventing algae is small. .

  In Comparative Example 21, the Fe content of the Zn—Al—Mg alloy plating exceeds 2% of the upper limit of the present invention, the corrosion resistance is poor, the algae propagates in the cracked and peeled portions of the plating, and the antialgae high effect Is also small. In Comparative Example 22, the Mg content of the Zn—Al—Mg alloy plating exceeds 5% of the upper limit of the present invention, the corrosion resistance is poor, the algae grows on the cracked and peeled portions of the plating, and the algae-proofing high effect. Is also small. In Comparative Example 23, the Al content of the Zn—Al—Mg alloy plating exceeds 20% of the upper limit of the present invention, and the Mg content exceeds 5% of the upper limit of the present invention, the corrosion resistance is poor, the cracking of the plating, Algae grow on the peeled site, and the high alga-proof effect is small.

Claims (4)

It is a plated steel wire having a hot dip galvanized layer in which the average composition is Fe in mass% and Fe: 2% or less, the balance is made of Zn and inevitable impurities, and Cu is dispersed,
A plated steel wire containing Cu in the plated layer, wherein the area index of the region of 10% or more by Cu mass% on the surface of the plated layer is 2% or more and 35% or less.
The area index is a square area of 1/4 length of the wire diameter in the plating layer surface as a measurement area by a scanning electron microscope (SEM) and an energy dispersive composition analyzer (EDS) attached thereto. Is measured at three locations, and the area of 10% or more of the area is measured by Cu mass%, which is divided by the total measurement area and expressed in%.   2. The plated steel wire according to claim 1, wherein the average composition of the hot-dip plating layer is further contained by mass% and Al: 60% or less.   2. The plated steel wire containing Cu in the plated layer according to claim 1, wherein the average composition of the hot-dip plated layer is further mass%, and Al: 20% or less and Mg: 5% or less.     The wire mesh manufactured from the plated steel wire which contains Cu in any one of Claims 1-3 in a plating layer.

Images